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Chan T, Chen Y, Tan KT, Wu C, Wu W, Li W, Wang J, Shiue Y, Li C. Biological significance of MYC and CEBPD coamplification in urothelial carcinoma: Multilayered genomic, transcriptional and posttranscriptional positive feedback loops enhance oncogenic glycolysis. Clin Transl Med 2021; 11:e674. [PMID: 34954904 PMCID: PMC8710299 DOI: 10.1002/ctm2.674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/18/2021] [Accepted: 11/25/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE The aim of this study is to decipher the underlying mechanisms of CCAAT/enhancer-binding protein delta (CEBPD)-enhanced glycolysis as well as the biological significance of CEBPD and MYC coamplification in urothelial carcinoma (UC). METHODS In vitro analyses were conducted to examine the effects of altered CEBPD or MYC expression on UC cells. The in vivo effects of CEBPD overexpression in a high-glucose environment on tumour growth were investigated in xenografted induced diabetic severe combined immunodeficiency/beige mice. Data mining was used to cross-validate the associations between CEBPD and MYC copy number and transcriptional expression, quantitative reverse transcription-polymerase chain reaction, immunohistochemistry, chromogenic in situ hybridization, and in situ hybridization targeting microRNA were performed on 635 UC patient samples and xenograft samples. UC patient survival in relation to diabetes was validated by using the National Health Insurance Research Database. RESULTS CEBPD and MYC coamplification (29.6%) occurred at a high frequency, MYC expression promoted chromosomal instability, facilitating CEBPD copy number gain and expression. CEBPD promoted glucose uptake and lactate production by upregulating SLC2A1 and HK2, leading to mitochondrial fission, increased extracellular acidification rate and decreased oxygen consumption rate to fuel cell growth. CEBPD upregulated HK2 expression through multiple regulation pathways including MYC stabilization, suppression of FBXW7 transactivation and MYC-independent transcriptional suppression of hsa-miR-429. Clinical and xenografted experiments confirmed the growth advantage of CEBPD in relation to glucose metabolic dysregulation and the significant correlations between the expression of these genes. CONCLUSIONS We confirmed that CEBPD has an oncogenic role in UC by activating AKT signalling and initiating metabolic reprogramming from mitochondrial oxidative phosphorylation to glycolysis to satisfy glucose addiction. These novel CEBPD- and MYC-centric multilayered positive feedback loops enhance cancer growth that could complement theranostic approaches.
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Affiliation(s)
- Ti‐Chun Chan
- Department of Medical ResearchChi Mei Medical CenterTainanTaiwan
- National Institute of Cancer ResearchNational Health Research InstitutesTainanTaiwan
| | - Yi‐Ting Chen
- Department of Biotechnology and Bioindustry SciencesCollege of Bioscience and BiotechnologyNational Cheng Kung UniversityTainanTaiwan
| | | | | | - Wen‐Jeng Wu
- Graduate Institute of Clinical MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
- Department of UrologyKaohsiung Medical University HospitalKaohsiungTaiwan
- Department of UrologySchool of MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
- Department of UrologyMinistry of Health and Welfare Pingtung HospitalPingtungTaiwan
| | - Wei‐Ming Li
- Graduate Institute of Clinical MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
- Department of UrologyKaohsiung Medical University HospitalKaohsiungTaiwan
- Department of UrologySchool of MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
- Department of UrologyMinistry of Health and Welfare Pingtung HospitalPingtungTaiwan
| | - Ju‐Ming Wang
- Department of Biotechnology and Bioindustry SciencesCollege of Bioscience and BiotechnologyNational Cheng Kung UniversityTainanTaiwan
| | - Yow‐Ling Shiue
- Institute of Precision MedicineNational Sun Yat‐Sen UniversityKaohsiungTaiwan
- Department of PathologySchool of MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
| | - Chien‐Feng Li
- Department of Medical ResearchChi Mei Medical CenterTainanTaiwan
- National Institute of Cancer ResearchNational Health Research InstitutesTainanTaiwan
- Institute of Precision MedicineNational Sun Yat‐Sen UniversityKaohsiungTaiwan
- Department of PathologySchool of MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
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2
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Lin YL, Wei CW, Lerdall TA, Nhieu J, Wei LN. Crabp1 Modulates HPA Axis Homeostasis and Anxiety-like Behaviors by Altering FKBP5 Expression. Int J Mol Sci 2021; 22:12240. [PMID: 34830120 PMCID: PMC8619219 DOI: 10.3390/ijms222212240] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 12/22/2022] Open
Abstract
Retinoic acid (RA), the principal active metabolite of vitamin A, is known to be involved in stress-related disorders. However, its mechanism of action in this regard remains unclear. This study reports that, in mice, endogenous cellular RA binding protein 1 (Crabp1) is highly expressed in the hypothalamus and pituitary glands. Crabp1 knockout (CKO) mice exhibit reduced anxiety-like behaviors accompanied by a lowered stress induced-corticosterone level. Furthermore, CRH/DEX tests show an increased sensitivity (hypersensitivity) of their feedback inhibition in the hypothalamic-pituitary-adrenal (HPA) axis. Gene expression studies show reduced FKBP5 expression in CKO mice; this would decrease the suppression of glucocorticoid receptor (GR) signaling thereby enhancing their feedback inhibition, consistent with their dampened corticosterone level and anxiety-like behaviors upon stress induction. In AtT20, a pituitary gland adenoma cell line elevating or reducing Crabp1 level correspondingly increases or decreases FKBP5 expression, and its endogenous Crabp1 level is elevated by GR agonist dexamethasone or RA treatment. This study shows, for the first time, that Crabp1 regulates feedback inhibition of the the HPA axis by modulating FKBP5 expression. Furthermore, RA and stress can increase Crabp1 level, which would up-regulate FKBP5 thereby de-sensitizing feedback inhibition of HPA axis (by decreasing GR signaling) and increasing the risk of stress-related disorders.
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Affiliation(s)
| | | | | | | | - Li-Na Wei
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (Y.-L.L.); (C.-W.W.); (T.A.L.); (J.N.)
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3
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Porteous R, Haden P, Hackwell ECR, Singline A, Herde MK, Desai R, Handelsman DJ, Grattan DR, Herbison AE. Reformulation of PULSAR for Analysis of Pulsatile LH Secretion and a Revised Model of Estrogen-Negative Feedback in Mice. Endocrinology 2021; 162:6349057. [PMID: 34383026 DOI: 10.1210/endocr/bqab165] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Indexed: 11/19/2022]
Abstract
The recent use of the tail-tip bleeding approach in mice has enabled researchers to generate detailed pulse and surge profiles of luteinizing hormone (LH) secretion in mice. However, the analysis of pulsatile LH secretion is piecemeal across the field with each laboratory using their own methodology. We have reformulated the once-popular PULSAR algorithm of Merriam and Wachter to operate on contemporary computer systems and provide downloadable and online pulse analysis platforms. As it is now possible to record the activity of the gonadotropin-releasing hormone pulse generator in freely behaving mice, we have been able to unambiguously define LH pulses in intact and gonadectomized male and female mice. These data sets were used to determine the appropriate PULSAR parameter sets for analyzing pulsatile LH secretion in the mouse. This was then used to establish an accurate model of estrogen negative feedback in the mouse. Intact and ovariectomized mice given Silastic capsules containing 1, 2, and 4 μg 17-β-estradiol/20 g body weight were tail-tip bled at 6-min intervals, and the resultant LH profiles were analyzed with PULSAR. Only the 4 μg 17-β-estradiol capsule treatment was found to return LH pulse amplitude and frequency to that of intact diestrous mice. Ultrasensitive mass spectrometry analysis showed that the 4 μg 17-β-estradiol capsule generated circulating estradiol levels equivalent to that of diestrous mice. It is hoped that the reformulation of PULSAR and generation of a realistic model of estrogen-negative feedback will provide a platform for the more uniform assessment of pulsatile hormone secretion in mice.
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Affiliation(s)
- Robert Porteous
- Department of Physiology, University of Otago, Dunedin, New Zealand
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - Patricia Haden
- RTIS Scientific Programming, University of Otago, Dunedin, New Zealand
| | - Eleni C R Hackwell
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Aaron Singline
- Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Michel K Herde
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - Reena Desai
- ANZAC Research Institute, Andrology Department, Concord Hospital, Sydney, Australia
| | - David J Handelsman
- ANZAC Research Institute, Andrology Department, Concord Hospital, Sydney, Australia
| | - David R Grattan
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Allan E Herbison
- Department of Physiology, University of Otago, Dunedin, New Zealand
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
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Mohr MA, Esparza LA, Steffen P, Micevych PE, Kauffman AS. Progesterone Receptors in AVPV Kisspeptin Neurons Are Sufficient for Positive Feedback Induction of the LH Surge. Endocrinology 2021; 162:6348143. [PMID: 34379733 PMCID: PMC8423423 DOI: 10.1210/endocr/bqab161] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Indexed: 11/19/2022]
Abstract
Kisspeptin, encoded by Kiss1, stimulates gonadotropin-releasing hormone neurons to govern reproduction. In female rodents, estrogen-sensitive kisspeptin neurons in the rostral anteroventral periventricular (AVPV) hypothalamus are thought to mediate estradiol (E2)-induced positive feedback induction of the preovulatory luteinizing hormone (LH) surge. AVPV kisspeptin neurons coexpress estrogen and progesterone receptors (PGRs) and are activated during the LH surge. While E2 effects on kisspeptin neurons have been well studied, progesterone's regulation of kisspeptin neurons is less understood. Using transgenic mice lacking PGR exclusively in kisspeptin cells (termed KissPRKOs), we previously demonstrated that progesterone action specifically in kisspeptin cells is essential for ovulation and normal fertility. Unlike control females, KissPRKO females did not generate proper LH surges, indicating that PGR signaling in kisspeptin cells is required for positive feedback. However, because PGR was knocked out from all kisspeptin neurons in the brain, that study was unable to determine the specific kisspeptin population mediating PGR action on the LH surge. Here, we used targeted Cre-mediated adeno-associated virus (AAV) technology to reintroduce PGR selectively into AVPV kisspeptin neurons of adult KissPRKO females, and tested whether this rescues occurrence of the LH surge. We found that targeted upregulation of PGR in kisspeptin neurons exclusively in the AVPV is sufficient to restore proper E2-induced LH surges in KissPRKO females, suggesting that this specific kisspeptin population is a key target of the necessary progesterone action for the surge. These findings further highlight the critical importance of progesterone signaling, along with E2 signaling, in the positive feedback induction of LH surges and ovulation.
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Affiliation(s)
- Margaret A Mohr
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, Los Angeles, CA 90095, USA
| | - Lourdes A Esparza
- Department of OBGYN and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Paige Steffen
- Department of OBGYN and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Paul E Micevych
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, Los Angeles, CA 90095, USA
| | - Alexander S Kauffman
- Department of OBGYN and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Correspondence: Dr. Alexander S. Kauffman, Department of OBGYN and Reproductive Sciences, University of California, San Diego, 9500 Gilman Drive, #0674, La Jolla, CA 92093, USA. E-mail:
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Palacios-Filardo J, Udakis M, Brown GA, Tehan BG, Congreve MS, Nathan PJ, Brown AJH, Mellor JR. Acetylcholine prioritises direct synaptic inputs from entorhinal cortex to CA1 by differential modulation of feedforward inhibitory circuits. Nat Commun 2021; 12:5475. [PMID: 34531380 PMCID: PMC8445995 DOI: 10.1038/s41467-021-25280-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/21/2021] [Indexed: 02/08/2023] Open
Abstract
Acetylcholine release in the hippocampus plays a central role in the formation of new memory representations. An influential but largely untested theory proposes that memory formation requires acetylcholine to enhance responses in CA1 to new sensory information from entorhinal cortex whilst depressing inputs from previously encoded representations in CA3. Here, we show that excitatory inputs from entorhinal cortex and CA3 are depressed equally by synaptic release of acetylcholine in CA1. However, feedforward inhibition from entorhinal cortex exhibits greater depression than CA3 resulting in a selective enhancement of excitatory-inhibitory balance and CA1 activation by entorhinal inputs. Entorhinal and CA3 pathways engage different feedforward interneuron subpopulations and cholinergic modulation of presynaptic function is mediated differentially by muscarinic M3 and M4 receptors, respectively. Thus, our data support a role and mechanisms for acetylcholine to prioritise novel information inputs to CA1 during memory formation.
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Affiliation(s)
- Jon Palacios-Filardo
- Center for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol, UK
| | - Matt Udakis
- Center for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol, UK
| | - Giles A Brown
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abingdon, Cambridge, UK
- OMass Therapeutics Ltd, The Schrödinger Building, Oxford, UK
| | - Benjamin G Tehan
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abingdon, Cambridge, UK
- OMass Therapeutics Ltd, The Schrödinger Building, Oxford, UK
| | - Miles S Congreve
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abingdon, Cambridge, UK
| | - Pradeep J Nathan
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Alastair J H Brown
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abingdon, Cambridge, UK
| | - Jack R Mellor
- Center for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol, UK.
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6
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Zhao D, Chen J, Wang Y, Zhang L, Zhang J, Zhang W, Fan J, Li J, Zhan Q. Feed-forward activation of STAT3 signaling limits the efficacy of c-Met inhibitors in esophageal squamous cell carcinoma (ESCC) treatment. Mol Carcinog 2021; 60:481-496. [PMID: 34018249 DOI: 10.1002/mc.23306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 01/12/2023]
Abstract
c-Hepatocyte growth factor receptor (Met) inhibitors have demonstrated clinical benefits in some types of solid tumors. However, the efficacy of c-Met inhibitors in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we discovered that c-Met inhibitors induced "Signal Transducer and Activator of Transcription (STAT3)-addiction" in ESCC cells, and the feedback activation of STAT3 in ESCC cells limits the tumor response to c-Met inhibition. Mechanistically, c-Met inhibition increased the autocrine of several cytokines, including CCL2, interleukin 8, or leukemia inhibitory factor, and facilitated the interactions between the receptors of these cytokines and Janus Kinase1/2 (JAK1/2) to resultantly activate JAKs/STAT3 signaling. Pharmacological inhibition of c-Met together with cytokines/JAKs/STAT3 axis enhanced cancer cells regression in vitro. Importantly, combined c-Met and STAT3 inhibitors synergistically suppressed tumor growth and promoted the apoptosis of tumor cells without producing systematic toxicity. These findings suggest that inhibition of the STAT3 feedback loop may augment the response to c-Met inhibitors via the STAT3-mediated oncogene addiction in ESCC cells.
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Affiliation(s)
- Di Zhao
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jie Chen
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Yan Wang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Lingyuan Zhang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jing Zhang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Weimin Zhang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jiawen Fan
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jinting Li
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Qimin Zhan
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
- Shenzhen Bay Laboratory, Institute of Cancer Research, Shenzhen, China
- Research Unit of Molecular Cancer Research, Chinese Academy of Medical Sciences, Beijing, China
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7
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Mitchell CS, Begg DP. The regulation of food intake by insulin in the central nervous system. J Neuroendocrinol 2021; 33:e12952. [PMID: 33656205 DOI: 10.1111/jne.12952] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/31/2021] [Accepted: 02/03/2021] [Indexed: 01/02/2023]
Abstract
Food intake and energy expenditure are regulated by peripheral signals providing feedback on nutrient status and adiposity to the central nervous system. One of these signals is the pancreatic hormone, insulin. Unlike peripheral administration of insulin, which often causes weight gain, central administration of insulin leads to a reduction in food intake and body weight when administered long-term. This is a result of feedback processes in regions of the brain that regulate food intake. Within the hypothalamus, the arcuate nucleus (ARC) contains subpopulations of neurones that produce orexinergic neuropeptides agouti-related peptide (AgRP)/neuropeptide Y (NPY) and anorexigenic neuropeptides, pro-opiomelanocortin (POMC)/cocaine- and amphetamine-regulated transcript (CART). Intracerebroventricular infusion of insulin down-regulates the expression of AgRP/NPY at the same time as up-regulating expression of POMC/CART. Recent evidence suggests that insulin activity within the amygdala may play an important role in regulating energy balance. Insulin infusion into the central nucleus of the amygdala (CeA) can decrease food intake, possibly by modulating activity of NPY and other neurone subpopulations. Insulin signalling within the CeA can also influence stress-induced obesity. Overall, it is evident that the CeA is a critical target for insulin signalling and the regulation of energy balance.
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Affiliation(s)
| | - Denovan P Begg
- School of Psychology, UNSW Sydney, Sydney, NSW, Australia
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Fontan L, Goldstein R, Casalena G, Durant M, Teater MR, Wilson J, Phillip J, Xia M, Shah S, Us I, Shinglot H, Singh A, Inghirami G, Melnick A. Identification of MALT1 feedback mechanisms enables rational design of potent antilymphoma regimens for ABC-DLBCL. Blood 2021; 137:788-800. [PMID: 32785655 PMCID: PMC7885826 DOI: 10.1182/blood.2019004713] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
MALT1 inhibitors are promising therapeutic agents for B-cell lymphomas that are dependent on constitutive or aberrant signaling pathways. However, a potential limitation for signal transduction-targeted therapies is the occurrence of feedback mechanisms that enable escape from the full impact of such drugs. Here, we used a functional genomics screen in activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) cells treated with a small molecule irreversible inhibitor of MALT1 to identify genes that might confer resistance or enhance the activity of MALT1 inhibition (MALT1i). We find that loss of B-cell receptor (BCR)- and phosphatidylinositol 3-kinase (PI3K)-activating proteins enhanced sensitivity, whereas loss of negative regulators of these pathways (eg, TRAF2, TNFAIP3) promoted resistance. These findings were validated by knockdown of individual genes and a combinatorial drug screen focused on BCR and PI3K pathway-targeting drugs. Among these, the most potent combinatorial effect was observed with PI3Kδ inhibitors against ABC-DLBCLs in vitro and in vivo, but that led to an adaptive increase in phosphorylated S6 and eventual disease progression. Along these lines, MALT1i promoted increased MTORC1 activity and phosphorylation of S6K1-T389 and S6-S235/6, an effect that was only partially blocked by PI3Kδ inhibition in vitro and in vivo. In contrast, simultaneous inhibition of MALT1 and MTORC1 prevented S6 phosphorylation, yielded potent activity against DLBCL cell lines and primary patient specimens, and resulted in more profound tumor regression and significantly improved survival of ABC-DLBCLs in vivo compared with PI3K inhibitors. These findings provide a basis for maximal therapeutic impact of MALT1 inhibitors in the clinic, by disrupting feedback mechanisms that might otherwise limit their efficacy.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Drug Design
- Drug Resistance, Neoplasm
- Drug Synergism
- Feedback, Physiological/drug effects
- Female
- Humans
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Mechanistic Target of Rapamycin Complex 1/antagonists & inhibitors
- Mechanistic Target of Rapamycin Complex 1/metabolism
- Mice
- Mice, Inbred NOD
- Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein/antagonists & inhibitors
- Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein/physiology
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/physiology
- Organoids/drug effects
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphorylation/drug effects
- Protein Processing, Post-Translational/drug effects
- RNA, Small Interfering/genetics
- Receptors, Antigen, B-Cell/immunology
- Ribosomal Protein S6 Kinases/metabolism
- Signal Transduction/drug effects
- Toll-Like Receptors/immunology
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Lorena Fontan
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Rebecca Goldstein
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Gabriella Casalena
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Matthew Durant
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Matthew R Teater
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Jimmy Wilson
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Jude Phillip
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Min Xia
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Shivem Shah
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY; and
| | - Ilkay Us
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Himaly Shinglot
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Ankur Singh
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY; and
| | - Giorgio Inghirami
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY
| | - Ari Melnick
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY
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Huang YN, Chiang SL, Lin YJ, Liu SC, Li YH, Liao YC, Lee MR, Su PH, Tsai FJ, Hung HC, Wang CH. Long, Noncoding RNA SRA Induces Apoptosis of β-Cells by Promoting the IRAK1/LDHA/Lactate Pathway. Int J Mol Sci 2021; 22:ijms22041720. [PMID: 33572095 PMCID: PMC7914996 DOI: 10.3390/ijms22041720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 01/05/2023] Open
Abstract
Long non-coding RNA steroid receptor RNA activators (LncRNA SRAs) are implicated in the β-cell destruction of Type 1 diabetes mellitus (T1D), but functional association remains poorly understood. Here, we aimed to verify the role of LncRNA SRA regulation in β-cells. LncRNA SRAs were highly expressed in plasma samples and peripheral blood mononuclear cells (PBMCs) from T1D patients. LncRNA SRA was strongly upregulated by high-glucose treatment. LncRNA SRA acts as a microRNA (miR)-146b sponge through direct sequence–structure interactions. Silencing of lncRNA SRA increased the functional genes of Tregs, resulting in metabolic reprogramming, such as decreased lactate levels, repressed lactate dehydrogenase A (LDHA)/phosphorylated LDHA (pLDHA at Tyr10) expression, decreased reactive oxygen species (ROS) production, increased ATP production, and finally, decreased β-cell apoptosis in vitro. There was a positive association between lactate level and hemoglobin A1c (HbA1c) level in the plasma from patients with T1D. Recombinant human interleukin (IL)-2 treatment repressed lncRNA SRA expression and activity in β-cells. Higher levels of lncRNA-SRA/lactate in the plasma are associated with poor regulation in T1D patients. LncRNA SRA contributed to T1D pathogenesis through the inhibition of miR-146b in β-cells, with activating signaling transduction of interleukin-1 receptor-associated kinase 1 (IRAK1)/LDHA/pLDHA. Taken together, LncRNA SRA plays a critical role in the function of β-cells.
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Affiliation(s)
- Yu-Nan Huang
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan; (Y.-N.H.); (H.-C.H.)
- Division of Genetics and Metabolism, Children’s Hospital of China Medical University, Taichung 402, Taiwan
| | - Shang-Lun Chiang
- Department of Medical Laboratory Science, I-Shou University, Kaohsiung 824, Taiwan;
| | - Yu-Jung Lin
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan;
| | - Su-Ching Liu
- Department of Medical Research, Children’s Hospital of China Medical University, Taichung 404, Taiwan;
| | - Yen-Hsien Li
- Department of Chemistry, National Chung Hsing University, Taichung 420, Taiwan; (Y.-H.L.); (M.-R.L.)
- Instrument Center, Office of Research and Development, National Chung Hsing University, Taichung 420, Taiwan;
| | - Yu-Chen Liao
- Instrument Center, Office of Research and Development, National Chung Hsing University, Taichung 420, Taiwan;
| | - Maw-Rong Lee
- Department of Chemistry, National Chung Hsing University, Taichung 420, Taiwan; (Y.-H.L.); (M.-R.L.)
| | - Pen-Hua Su
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung 412, Taiwan;
- School of Medicine, Chung Shan Medical University, Taichung City 40201, Taiwan
| | - Fuu-Jen Tsai
- Genetic Center, Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan;
| | - Hui-Chih Hung
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan; (Y.-N.H.); (H.-C.H.)
| | - Chung-Hsing Wang
- Division of Genetics and Metabolism, Children’s Hospital of China Medical University, Taichung 402, Taiwan
- School of Medicine, China Medical University, Taichung 404, Taiwan
- Correspondence: ; Tel.: +886-4-2205-2121 (ext. 4641)
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Lopez-Rodriguez D, Franssen D, Bakker J, Lomniczi A, Parent AS. Cellular and molecular features of EDC exposure: consequences for the GnRH network. Nat Rev Endocrinol 2021; 17:83-96. [PMID: 33288917 DOI: 10.1038/s41574-020-00436-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/16/2020] [Indexed: 12/12/2022]
Abstract
The onset of puberty and the female ovulatory cycle are important developmental milestones of the reproductive system. These processes are controlled by a tightly organized network of neurotransmitters and neuropeptides, as well as genetic, epigenetic and hormonal factors, which ultimately drive the pulsatile secretion of gonadotropin-releasing hormone. They also strongly depend on organizational processes that take place during fetal and early postnatal life. Therefore, exposure to environmental pollutants such as endocrine-disrupting chemicals (EDCs) during critical periods of development can result in altered brain development, delayed or advanced puberty and long-term reproductive consequences, such as impaired fertility. The gonads and peripheral organs are targets of EDCs, and research from the past few years suggests that the organization of the neuroendocrine control of reproduction is also sensitive to environmental cues and disruption. Among other mechanisms, EDCs interfere with the action of steroidal and non-steroidal receptors, and alter enzymatic, metabolic and epigenetic pathways during development. In this Review, we discuss the cellular and molecular consequences of perinatal exposure (mostly in rodents) to representative EDCs with a focus on the neuroendocrine control of reproduction, pubertal timing and the female ovulatory cycle.
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Affiliation(s)
| | - Delphine Franssen
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Julie Bakker
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Alejandro Lomniczi
- Division of Neuroscience, Oregon National Primate Research Center (ONPRC), OHSU, OR, USA
| | - Anne-Simone Parent
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium.
- Department of Pediatrics, University Hospital Liège, Liège, Belgium.
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11
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Ungefroren H. Autocrine TGF-β in Cancer: Review of the Literature and Caveats in Experimental Analysis. Int J Mol Sci 2021; 22:977. [PMID: 33478130 PMCID: PMC7835898 DOI: 10.3390/ijms22020977] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/14/2022] Open
Abstract
Autocrine signaling is defined as the production and secretion of an extracellular mediator by a cell followed by the binding of that mediator to receptors on the same cell to initiate signaling. Autocrine stimulation often operates in autocrine loops, a type of interaction, in which a cell produces a mediator, for which it has receptors, that upon activation promotes expression of the same mediator, allowing the cell to repeatedly autostimulate itself (positive feedback) or balance its expression via regulation of a second factor that provides negative feedback. Autocrine signaling loops with positive or negative feedback are an important feature in cancer, where they enable context-dependent cell signaling in the regulation of growth, survival, and cell motility. A growth factor that is intimately involved in tumor development and progression and often produced by the cancer cells in an autocrine manner is transforming growth factor-β (TGF-β). This review surveys the many observations of autocrine TGF-β signaling in tumor biology, including data from cell culture and animal models as well as from patients. We also provide the reader with a critical discussion on the various experimental approaches employed to identify and prove the involvement of autocrine TGF-β in a given cellular response.
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Affiliation(s)
- Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany;
- Clinic for General Surgery, Visceral, Thoracic, Transplantation and Pediatric Surgery, University Hospital Schleswig-Holstein, Campus Kiel, D-24105 Kiel, Germany
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12
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Kavčič B, Tkačik G, Bollenbach T. Minimal biophysical model of combined antibiotic action. PLoS Comput Biol 2021; 17:e1008529. [PMID: 33411759 PMCID: PMC7817058 DOI: 10.1371/journal.pcbi.1008529] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/20/2021] [Accepted: 11/12/2020] [Indexed: 11/18/2022] Open
Abstract
Phenomenological relations such as Ohm's or Fourier's law have a venerable history in physics but are still scarce in biology. This situation restrains predictive theory. Here, we build on bacterial "growth laws," which capture physiological feedback between translation and cell growth, to construct a minimal biophysical model for the combined action of ribosome-targeting antibiotics. Our model predicts drug interactions like antagonism or synergy solely from responses to individual drugs. We provide analytical results for limiting cases, which agree well with numerical results. We systematically refine the model by including direct physical interactions of different antibiotics on the ribosome. In a limiting case, our model provides a mechanistic underpinning for recent predictions of higher-order interactions that were derived using entropy maximization. We further refine the model to include the effects of antibiotics that mimic starvation and the presence of resistance genes. We describe the impact of a starvation-mimicking antibiotic on drug interactions analytically and verify it experimentally. Our extended model suggests a change in the type of drug interaction that depends on the strength of resistance, which challenges established rescaling paradigms. We experimentally show that the presence of unregulated resistance genes can lead to altered drug interaction, which agrees with the prediction of the model. While minimal, the model is readily adaptable and opens the door to predicting interactions of second and higher-order in a broad range of biological systems.
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Affiliation(s)
- Bor Kavčič
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Gašper Tkačik
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Tobias Bollenbach
- Institute for Biological Physics, University of Cologne, Cologne, Germany
- Center for Data and Simulation Science, University of Cologne, Cologne, Germany
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13
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Phumsatitpong C, De Guzman RM, Zuloaga DG, Moenter SM. A CRH Receptor Type 1 Agonist Increases GABA Transmission to GnRH Neurons in a Circulating-Estradiol-Dependent Manner. Endocrinology 2020; 161:5892962. [PMID: 32798220 PMCID: PMC7547842 DOI: 10.1210/endocr/bqaa140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/06/2020] [Indexed: 12/15/2022]
Abstract
GnRH neurons are central regulators of reproduction and respond to factors affecting fertility, such as stress. Corticotropin-releasing hormone (CRH) is released during stress response. In brain slices from unstressed controls, CRH has opposite, estradiol-dependent effects on GnRH neuron firing depending on the CRH receptor activated; activating CRHR-1 stimulates whereas activating CRHR-2 suppresses activity. We investigated possible direct and indirect mechanisms. Mice were ovariectomized and either not treated further (OVX) or given a capsule producing high positive feedback (OVX + E) or low negative feedback (OVX + low E) physiologic circulating estradiol levels. We tested possible direct effects on GnRH neurons by altering voltage-gated potassium currents. Two types of voltage-gated potassium currents (transient IA and sustained IK) were measured; neither CRHR-1 nor CRHR-2 agonists altered potassium current density in GnRH neurons from OVX + E mice. Further, neither CRH nor receptor-specific agonists altered action potential generation in response to current injection in GnRH neurons from OVX + E mice. To test the possible indirect actions, GABAergic postsynaptic currents were monitored. A CRHR-1 agonist increased GABAergic transmission frequency to GnRH neurons from OVX + E, but not OVX, mice, whereas a CRHR-2 agonist had no effect. Finally, we tested if CRH alters the firing rate of arcuate kisspeptin neurons, which provide an important excitatory neuromodulatory input to GnRH neurons. CRH did not acutely alter firing activity of these neurons from OVX, OVX + E or OVX + low E mice. These results suggest CRH increases GnRH neuron activity in an estradiol-dependent manner in part by activating GABAergic afferents. Mechanisms underlying inhibitory effects of CRH remain unknown.
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Affiliation(s)
| | | | | | - Suzanne M Moenter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, US
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, US
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, US
- Correspondence: Suzanne M. Moenter; 7725 Med Sci II; 1137 E Catherine St; Ann Arbor, MI 48109-5622. E-mail:
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14
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Hengstler J, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? J Toxicol Environ Health A 2020; 83:485-494. [PMID: 32552445 DOI: 10.1080/15287394.2020.1756592] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Theoretically, both synthetic endocrine-disrupting chemicals (S-EDCs) and natural (exogenous and endogenous) endocrine-disrupting chemicals (N-EDCs) can interact with endocrine receptors and disturb hormonal balance. However, compared to endogenous hormones, S-EDCs are only weak partial agonists with receptor affinities several orders of magnitude lower than S-EDCs. Thus, to elicit observable effects, S-EDCs require considerably higher concentrations to attain sufficient receptor occupancy or to displace natural hormones and other endogenous ligands. Significant exposures to exogenous N-EDCs may result from ingestion of foods such as soy-based diets, green tea, and sweet mustard. While their potencies are lower as compared to natural endogenous hormones, they usually are considerably more potent than S-EDCs. Effects of exogenous N-EDCs on the endocrine system were observed at high dietary intakes. A causal relation between their mechanism of action and these effects is established and biologically plausible. In contrast, the assumption that the much lower human exposures to S-EDCs may induce observable endocrine effects is not plausible. Hence, it is not surprising that epidemiological studies searching for an association between S-EDC exposure and health effects have failed. Regarding testing for potential endocrine effects, a scientifically justified screen should use in vitro tests to compare potencies of S-EDCs with those of reference N-EDCs. When the potency of the S-EDC is similar or smaller than that of the N-EDC, further testing in laboratory animals and regulatory consequences are not warranted.
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Affiliation(s)
- Herman Autrup
- Institute of Public Health, University of Aarhus , Aarhus, Denmark
| | - Frank A Barile
- College of Pharmacy and Health Sciences, St John's University , Queens, USA
| | | | - Bas J Blaauboer
- Division of Toxicology, Institute for Risk Assessment Sciences, Utrecht University , Utrecht, The Netherlands
| | - Alan Boobis
- National Heart & Lung Institute, Imperial College , London, UK
| | - Herrmann Bolt
- Leibniz Research Centre for Working Environment and Human Factors (Ifado), TU Dortmund , Dortmund, Germany
| | | | - Wolfgang Dekant
- Department of Toxicology, University of Wuerzburg , Wuerzburg, Germany
| | - Daniel Dietrich
- Human and Environmental Toxicology, University of Konstanz , Konstanz, Germany
| | - Jose L Domingo
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat 'Rovira I Virgili' , Reus, Spain
| | | | - Helmut Greim
- Technical University of Munich D-85350, Freising-Weihenstephan, Germany
| | - Jan Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (Ifado), TU Dortmund , Dortmund, Germany
| | - Sam Kacew
- McLaughlin Centre for Risk Assessment, University of Ottawa , Ottawa, Canada
| | | | - Olavi Pelkonen
- Department of Pharmacology and Toxicology, University of Oulu , Finland
| | - Kai Savolainen
- Nanosafety Research Centre, Finnish Institute of Occupational Health , Helsinki, Finland
| | - Pat Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester , Leicester, UK
| | - Nico P Vermeulen
- Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit , Amsterdam, The Netherlands
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15
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Zamai L. The Yin and Yang of ACE/ACE2 Pathways: The Rationale for the Use of Renin-Angiotensin System Inhibitors in COVID-19 Patients. Cells 2020; 9:E1704. [PMID: 32708755 PMCID: PMC7408073 DOI: 10.3390/cells9071704] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/10/2020] [Accepted: 06/25/2020] [Indexed: 02/06/2023] Open
Abstract
The article describes the rationale for inhibition of the renin-angiotensin system (RAS) pathways as specific targets in patients infected by SARS-CoV-2 in order to prevent positive feedback-loop mechanisms. Based purely on experimental studies in which RAS pathway inhibitors were administered in vivo to humans/rodents, a reasonable hypothesis of using inhibitors that block both ACE and ACE2 zinc metalloproteases and their downstream pathways in COVID-19 patients will be proposed. In particular, metal (zinc) chelators and renin inhibitors may work alone or in combination to inhibit the positive feedback loops (initially triggered by SARS-CoV-2 and subsequently sustained by hypoxia independently on viral trigger) as both arms of renin-angiotensin system are upregulated, leading to critical, advanced and untreatable stages of the disease.
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Affiliation(s)
- Loris Zamai
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, 61032 Urbino, Italy; ; Tel.: +39-0722-304319
- INFN-Gran Sasso National Laboratory, Assergi, 67100 L’Aquila, Italy
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16
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Li S, Zhai J, Xu B, Liu J, Chu W, Wang D, Geng X, Chen ZJ, Du Y. Erythropoietin-producing hepatocellular receptor A7 restrains estrogen negative feedback of luteinizing hormone via ephrin A5 in the hypothalamus of female rats. Am J Physiol Endocrinol Metab 2020; 319:E81-E90. [PMID: 32396496 DOI: 10.1152/ajpendo.00046.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have previously shown that systemic injection of erythropoietin-producing hepatocellular receptor A7 (EPHA7)-Fc raises serum luteinizing hormone (LH) levels before ovulation in female rats, indicating the induction of EPHA7 in ovulation. In this study, we aimed to identify the mechanism and hypothalamus-pituitary-ovary (HPO) axis level underlying the promotion of LH secretion by EPHA7. Using an ovariectomized (OVX) rat model, in conjunction with low-dose 17β-estradiol (E2) treatment, we investigated the association between EPHA7-ephrin (EFN)A5 signaling and E2 negative feedback. Various rat models (OVX, E2-treated OVX, and abarelix treated) were injected with the recombinant EPHA7-Fc protein through the caudal vein to investigate the molecular mechanism underlying the promotion of LH secretion by EPHA7. Efna5 was observed strongly expressed in the arcuate nucleus of the female rat by using RNAscope in situ hybridization. Our results indicated that E2, combined with estrogen receptor (ER)α, but not ERβ, inhibited Efna5 and gonadotropin-releasing hormone 1 (Gnrh1) expressions in the hypothalamus. In addition, the systemic administration of EPHA7-Fc restrained the inhibition of Efna5 and Gnrh1 by E2, resulting in increased Efna5 and Gnrh1 expressions in the hypothalamus as well as increased serum LH levels. Collectively, our findings demonstrated the involvement of EPHA7-EFNA5 signaling in the regulation of LH and the E2 negative feedback pathway in the hypothalamus, highlighting the functional role of EPHA7 in female reproduction.
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Affiliation(s)
- Shang Li
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Junyu Zhai
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Bing Xu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Jiansheng Liu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Weiwei Chu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Dongshuang Wang
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Xueying Geng
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Zi-Jiang Chen
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
- Key laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Yanzhi Du
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
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17
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Kok F, Rosenblatt M, Teusel M, Nizharadze T, Gonçalves Magalhães V, Dächert C, Maiwald T, Vlasov A, Wäsch M, Tyufekchieva S, Hoffmann K, Damm G, Seehofer D, Boettler T, Binder M, Timmer J, Schilling M, Klingmüller U. Disentangling molecular mechanisms regulating sensitization of interferon alpha signal transduction. Mol Syst Biol 2020; 16:e8955. [PMID: 32696599 PMCID: PMC7373899 DOI: 10.15252/msb.20198955] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/29/2020] [Accepted: 06/16/2020] [Indexed: 12/20/2022] Open
Abstract
Tightly interlinked feedback regulators control the dynamics of intracellular responses elicited by the activation of signal transduction pathways. Interferon alpha (IFNα) orchestrates antiviral responses in hepatocytes, yet mechanisms that define pathway sensitization in response to prestimulation with different IFNα doses remained unresolved. We establish, based on quantitative measurements obtained for the hepatoma cell line Huh7.5, an ordinary differential equation model for IFNα signal transduction that comprises the feedback regulators STAT1, STAT2, IRF9, USP18, SOCS1, SOCS3, and IRF2. The model-based analysis shows that, mediated by the signaling proteins STAT2 and IRF9, prestimulation with a low IFNα dose hypersensitizes the pathway. In contrast, prestimulation with a high dose of IFNα leads to a dose-dependent desensitization, mediated by the negative regulators USP18 and SOCS1 that act at the receptor. The analysis of basal protein abundance in primary human hepatocytes reveals high heterogeneity in patient-specific amounts of STAT1, STAT2, IRF9, and USP18. The mathematical modeling approach shows that the basal amount of USP18 determines patient-specific pathway desensitization, while the abundance of STAT2 predicts the patient-specific IFNα signal response.
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Affiliation(s)
- Frédérique Kok
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
| | - Marcus Rosenblatt
- Institute of PhysicsUniversity of FreiburgFreiburgGermany
- FDM ‐ Freiburg Center for Data Analysis and ModelingUniversity of FreiburgFreiburgGermany
| | - Melissa Teusel
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
| | - Tamar Nizharadze
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
| | - Vladimir Gonçalves Magalhães
- Research Group “Dynamics of Early Viral Infection and the Innate Antiviral Response”Division Virus‐Associated CarcinogenesisGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Christopher Dächert
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
- Research Group “Dynamics of Early Viral Infection and the Innate Antiviral Response”Division Virus‐Associated CarcinogenesisGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Tim Maiwald
- Institute of PhysicsUniversity of FreiburgFreiburgGermany
| | - Artyom Vlasov
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
| | - Marvin Wäsch
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Silvana Tyufekchieva
- Department of General, Visceral and Transplantation SurgeryRuprecht Karls University HeidelbergHeidelbergGermany
| | - Katrin Hoffmann
- Department of General, Visceral and Transplantation SurgeryRuprecht Karls University HeidelbergHeidelbergGermany
| | - Georg Damm
- Department of Hepatobiliary Surgery and Visceral TransplantationUniversity of LeipzigLeipzigGermany
| | - Daniel Seehofer
- Department of Hepatobiliary Surgery and Visceral TransplantationUniversity of LeipzigLeipzigGermany
| | - Tobias Boettler
- Department of Medicine IIUniversity Hospital Freiburg—Faculty of MedicineUniversity of FreiburgFreiburgGermany
| | - Marco Binder
- Research Group “Dynamics of Early Viral Infection and the Innate Antiviral Response”Division Virus‐Associated CarcinogenesisGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Jens Timmer
- Institute of PhysicsUniversity of FreiburgFreiburgGermany
- FDM ‐ Freiburg Center for Data Analysis and ModelingUniversity of FreiburgFreiburgGermany
- Signalling Research Centres BIOSS and CIBSSUniversity of FreiburgFreiburgGermany
- Center for Biological Systems Analysis (ZBSA)University of FreiburgFreiburgGermany
| | - Marcel Schilling
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Ursula Klingmüller
- Division Systems Biology of Signal TransductionGerman Cancer Research Center (DKFZ)HeidelbergGermany
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18
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Cheung TP, Choe JY, Richmond JE, Kim H. BK channel density is regulated by endoplasmic reticulum associated degradation and influenced by the SKN-1A/NRF1 transcription factor. PLoS Genet 2020; 16:e1008829. [PMID: 32502151 PMCID: PMC7299407 DOI: 10.1371/journal.pgen.1008829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 06/17/2020] [Accepted: 05/05/2020] [Indexed: 12/19/2022] Open
Abstract
Ion channels are present at specific levels within subcellular compartments of excitable cells. The regulation of ion channel trafficking and targeting is an effective way to control cell excitability. The BK channel is a calcium-activated potassium channel that serves as a negative feedback mechanism at presynaptic axon terminals and sites of muscle excitation. The C. elegans BK channel ortholog, SLO-1, requires an endoplasmic reticulum (ER) membrane protein for efficient anterograde transport to these locations. Here, we found that, in the absence of this ER membrane protein, SLO-1 channels that are seemingly normally folded and expressed at physiological levels undergo SEL-11/HRD1-mediated ER-associated degradation (ERAD). This SLO-1 degradation is also indirectly regulated by a SKN-1A/NRF1-mediated transcriptional mechanism that controls proteasome levels. Therefore, our data indicate that SLO-1 channel density is regulated by the competitive balance between the efficiency of ER trafficking machinery and the capacity of ERAD. Excitable cells, such as neurons and muscles, are essential for the movement and behavior of animals. These cells express a set of specific types of ion channels that allow the selective passage of ions across the plasma membrane. The alteration in the levels of these ion channels influences cell excitability and the function of excitable cells. The regulation of ion channel trafficking and targeting is an effective way to control the function of excitable cells. The BK SLO-1 channel is a calcium-activated potassium channel that reduces excitability at presynaptic axon terminals and sites of muscle excitation. In a C. elegans genetic study, authors found that the delayed exit of SLO-1 channels from the ER causes their degradation by a mechanism called ER-associated degradation (ERAD). Interestingly, the same components that directly mediate SLO-1 ERAD also process a key transcriptional factor that maintains proteasome levels, thus indirectly influencing SLO-1 degradation. These data show that the levels of SLO-1 channels are regulated by the competitive balance between the efficiency of ER trafficking machinery and the capacity of ERAD.
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Affiliation(s)
- Timothy P. Cheung
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois, United States of America
- School of Graduate & Postdoctoral Studies, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois, United States of America
| | - Jun-Yong Choe
- School of Graduate & Postdoctoral Studies, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois, United States of America
- Department of Biochemistry and Molecular Biology, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois United States of America
| | - Janet E. Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Hongkyun Kim
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois, United States of America
- School of Graduate & Postdoctoral Studies, Rosalind Franklin University of Medicine & Science, North Chicago, Illinois, United States of America
- * E-mail:
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Yu Q, Peng C, Ye Z, Tang Z, Li S, Xiao L, Liu S, Yang Y, Zhao M, Zhang Y, Lin H. An estradiol-17β/miRNA-26a/cyp19a1a regulatory feedback loop in the protogynous hermaphroditic fish, Epinephelus coioides. Mol Cell Endocrinol 2020; 504:110689. [PMID: 31891771 DOI: 10.1016/j.mce.2019.110689] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/27/2022]
Abstract
Cyp19a1a is a key gene responsible for the production of estradiol-17β (E2), the main functional estrogen and a major downstream regulator of reproduction in teleost fish. It is widely known that CYP19 gene expression, aromatase activity, and E2 production can influence gonadal differentiation and sex reversal in teleost fish, but the feedback mechanisms whereby E2 regulates cyp19a1a remain poorly understood, especially regarding the potential roles of endogenous small RNA molecules (miRNAs). Here, we identified miR-26a-5p as a regulatory factor of its predicted target gene (cyp19a1a). In vitro and in vivo studies showed that miR-26a-5p can decrease cyp19a1a expression. Furthermore, high doses of E2 act as a repressor of miR-26a-5p. This study proposes a regulatory feedback loop whereby E2 regulates cyp19a1a through miR-26a-5p, and suggests that this positive feedback is an important aspect of the control of E2 production.
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Affiliation(s)
- Qi Yu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266373, China; Southern Marine Science and Engineering Guangdong Laboratory (ZhanJiang), Fisheries College, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Cheng Peng
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China; Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, 510260, China
| | - Zhifeng Ye
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China
| | - Zhujing Tang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China
| | - Shuisheng Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (ZhanJiang), Fisheries College, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Ling Xiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (ZhanJiang), Fisheries College, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Su Liu
- Marine Fisheries Development Center of Guangdong Province, Huizhou, 516081, China
| | - Yuqing Yang
- Marine Fisheries Development Center of Guangdong Province, Huizhou, 516081, China
| | - Mi Zhao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China.
| | - Yong Zhang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266373, China; Southern Marine Science and Engineering Guangdong Laboratory (ZhanJiang), Fisheries College, Guangdong Ocean University, Zhanjiang, 524088, China; Marine Fisheries Development Center of Guangdong Province, Huizhou, 516081, China.
| | - Haoran Lin
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, PR China
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Lin Q, Qu M, Patra HK, He S, Wang L, Hu X, Xiao L, Fu Y, Gong T, He Q, Zhang L, Sun X, Zhang Z. Mechanistic and therapeutic study of novel anti-tumor function of natural compound imperialine for treating non-small cell lung cancer. J Ethnopharmacol 2020; 247:112283. [PMID: 31605736 DOI: 10.1016/j.jep.2019.112283] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/26/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Bulbus Fritillaria cirrhosa D. Don (BFC) is a Chinese traditional herbal medicine that has long been used as an indispensable component in herbal prescriptions for bronchopulmonary diseases due to its well-established strong anti-inflammation and pulmonary harmonizing effects. Interestingly, there are few case reports in traditional Chinese medicine available where they found it to contribute in anti-tumor therapies. Imperialine is one of the most favored active substances extracted from BFC and has been widely recognized as an anti-inflammatory agent. AIM OF THE STUDY The aim of the current work is to provide first-hand evidences both in vitro and in vivo showing that imperialine exerts anti-cancer effects against non-small cell lung cancer (NSCLC), and to explore the molecular mechanism of this anti-tumor activity. It is also necessary to examine its systemic toxicity, and to investigate how to develop strategies for feasible clinical translation of imperialine. MATERIALS AND METHODS To investigate anti-NSCLC efficacy of imperialine using both in vitro and in vivo methods where A549 cell line were chosen as in vitro model NSCLC cells and A549 tumor-bearing mouse model was constructed for in vivo study. The detailed underlying anti-cancer mechanism has been systematically explored for the first time through a comprehensive set of molecular biology methods mainly including immunohistochemistry, western blot and enzyme-linked immunosorbent assays. The toxicity profile of imperialine treatments were evaluated using healthy nude mice by examining hemogram and histopathology. An imperialine-loaded liposomal drug delivery system was developed using thin film hydration method to evaluate target specific delivery. RESULTS The results showed that imperialine could suppress both NSCLC tumor and associated inflammation through an inflammation-cancer feedback loop in which NF-κB activity was dramatically inhibited by imperialine. The NSCLC-targeting liposomal system was successfully developed for targeted drug delivery. The developed platform could favorably enhance imperialine cellular uptake and in vivo accumulation at tumor sites, thus improving overall anti-tumor effect. The toxicity assays revealed imperialine treatments did not significantly disturb blood cell counts in mice or exert any significant damage to the main organs. CONCLUSIONS Imperialine exerts anti-cancer effects against NSCLC both in vitro and in vivo, and this previously unknown function is related to NF-κB centered inflammation-cancer feedback loop. Imperialine mediated anti-cancer activity is not through cytotoxicity and exhibit robust systemic safety. Furthermore, the liposome-based system we commenced would dramatically enhance therapeutic effects of imperialine while exhibiting extremely low side effects both on cellular and in NSCLC model. This work has identified imperialine as a promising novel anti-cancer compound and offered an efficient target-delivery solution that greatly facilitate practical use of imperialine.
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Affiliation(s)
- Qing Lin
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, United Kingdom
| | - Mengke Qu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Hirak K Patra
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, United Kingdom; Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, 58185, Sweden; Wolfson College, University of Cambridge, Cambridge, CB3 9BB, United Kingdom
| | - Shanshan He
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Luyao Wang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Xun Hu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China; CQ MEDVT CO., LTD, Chongqing, 401122, PR China
| | - Linyu Xiao
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Yu Fu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Tao Gong
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Qin He
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Ling Zhang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China.
| | - Xun Sun
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Zhirong Zhang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Department of Pharmaceutics, College of Polymer Science and Engineering, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
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Vundavilli H, Datta A, Sima C, Hua J, Lopes R, Bittner M. Cryptotanshinone Induces Cell Death in Lung Cancer by Targeting Aberrant Feedback Loops. IEEE J Biomed Health Inform 2019; 24:2430-2438. [PMID: 31825884 DOI: 10.1109/jbhi.2019.2958042] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Signaling pathways oversee highly efficient cellular mechanisms such as growth, division, and death. These processes are controlled by robust negative feedback loops that inhibit receptor-mediated growth factor pathways. Specifically, the ERK, the AKT, and the S6K feedback loops attenuate signaling via growth factor receptors and other kinase receptors to regulate cell growth. Irregularity in any of these supervised processes can lead to uncontrolled cell proliferation and possibly Cancer. These irregularities primarily occur as mutated genes, and an exhaustive search of the perfect drug combination by performing experiments can be both costly and complex. Hence, in this paper, we model the Lung Cancer pathway as a Modified Boolean Network that incorporates feedback. By simulating this network, we theoretically predict the drug combinations that achieve the desired goal for the majority of mutations. Our theoretical analysis identifies Cryptotanshinone, a traditional Chinese herb derivative, as a potent drug component in the fight against cancer. We validated these theoretical results using multiple wet lab experiments carried out on H2073 and SW900 lung cancer cell lines.
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Granato M, Gilardini Montani MS, Zompetta C, Santarelli R, Gonnella R, Romeo MA, D'Orazi G, Faggioni A, Cirone M. Quercetin Interrupts the Positive Feedback Loop Between STAT3 and IL-6, Promotes Autophagy, and Reduces ROS, Preventing EBV-Driven B Cell Immortalization. Biomolecules 2019; 9:biom9090482. [PMID: 31547402 PMCID: PMC6769872 DOI: 10.3390/biom9090482] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 12/17/2022] Open
Abstract
The oncogenic gammaherpesvirus Epstein–Barr virus (EBV) immortalizes in vitro B lymphocytes into lymphoblastoid cell lines (LCLs), a model that gives the opportunity to explore the molecular mechanisms driving viral tumorigenesis. In this study, we addressed the potential of quercetin, a widely distributed flavonoid displaying antioxidant, anti-inflammatory, and anti-cancer properties, in preventing EBV-driven B cell immortalization. The results obtained indicated that quercetin inhibited thectivation of signal transducer and activator of transcription 3 (STAT3) induced by EBV infection and reduced molecules such as interleukin-6 (IL-6) and reactive oxidative species (ROS) known to be essential for the immortalization process. Moreover, we found that quercetin promoted autophagy and counteracted the accumulation of sequestosome1/p62 (SQSTM1/p62), ultimately leading to the prevention of B cell immortalization. These findings suggest that quercetin may have the potential to be used to counteract EBV-driven lymphomagenesis, especially if its stability is improved.
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Affiliation(s)
- Marisa Granato
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Maria Saveria Gilardini Montani
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Claudia Zompetta
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Roberta Santarelli
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Roberta Gonnella
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Maria Anele Romeo
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Gabriella D'Orazi
- Translational Research Area, Regina Elena National Cancer Institute, 00128 Rome, Italy.
- Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", 66013 Chieti, Italy.
| | - Alberto Faggioni
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
| | - Mara Cirone
- Department of Experimental Medicine, "Sapienza" University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy.
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Rinaldi L, Delle Donne R, Catalanotti B, Torres-Quesada O, Enzler F, Moraca F, Nisticò R, Chiuso F, Piccinin S, Bachmann V, Lindner HH, Garbi C, Scorziello A, Russo NA, Synofzik M, Stelzl U, Annunziato L, Stefan E, Feliciello A. Feedback inhibition of cAMP effector signaling by a chaperone-assisted ubiquitin system. Nat Commun 2019; 10:2572. [PMID: 31189917 PMCID: PMC6561907 DOI: 10.1038/s41467-019-10037-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 04/12/2019] [Indexed: 02/07/2023] Open
Abstract
Activation of G-protein coupled receptors elevates cAMP levels promoting dissociation of protein kinase A (PKA) holoenzymes and release of catalytic subunits (PKAc). This results in PKAc-mediated phosphorylation of compartmentalized substrates that control central aspects of cell physiology. The mechanism of PKAc activation and signaling have been largely characterized. However, the modes of PKAc inactivation by regulated proteolysis were unknown. Here, we identify a regulatory mechanism that precisely tunes PKAc stability and downstream signaling. Following agonist stimulation, the recruitment of the chaperone-bound E3 ligase CHIP promotes ubiquitylation and proteolysis of PKAc, thus attenuating cAMP signaling. Genetic inactivation of CHIP or pharmacological inhibition of HSP70 enhances PKAc signaling and sustains hippocampal long-term potentiation. Interestingly, primary fibroblasts from autosomal recessive spinocerebellar ataxia 16 (SCAR16) patients carrying germline inactivating mutations of CHIP show a dramatic dysregulation of PKA signaling. This suggests the existence of a negative feedback mechanism for restricting hormonally controlled PKA activities.
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Affiliation(s)
- Laura Rinaldi
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II, 80131, Naples, Italy
| | - Rossella Delle Donne
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II, 80131, Naples, Italy
| | - Bruno Catalanotti
- Department of Pharmacy, University Federico II, 80131, Naples, Italy
| | - Omar Torres-Quesada
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Florian Enzler
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Federica Moraca
- Department of Chemical Sciences, University Federico II, 80131, Naples, Italy
| | - Robert Nisticò
- European Brain Research Institute, Rita Levi-Montalcini Foundation and Department of Biology, University Tor Vergata, 00143, Rome, Italy
| | - Francesco Chiuso
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II, 80131, Naples, Italy
| | - Sonia Piccinin
- European Brain Research Institute, Rita Levi-Montalcini Foundation and Department of Biology, University Tor Vergata, 00143, Rome, Italy
| | - Verena Bachmann
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Herbert H Lindner
- Division of Clinical Biochemistry, Biocenter Medical University of Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Corrado Garbi
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II, 80131, Naples, Italy
| | - Antonella Scorziello
- Department of Neuroscience, Reproductive and Odontostomatological Sciences, University Federico II, 80131, Naples, Italy
| | | | - Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen and German Center for Neurodegenerative Diseases (DZNE), 72076, Tübingen, Germany
| | - Ulrich Stelzl
- Institute of Pharmaceutical Sciences, University of Graz and BioTechMed-Graz, 8010, Graz, Austria
| | | | - Eduard Stefan
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Antonio Feliciello
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II, 80131, Naples, Italy.
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Cheng Z, Brar GA. Global translation inhibition yields condition-dependent de-repression of ribosome biogenesis mRNAs. Nucleic Acids Res 2019; 47:5061-5073. [PMID: 30937450 PMCID: PMC6547411 DOI: 10.1093/nar/gkz231] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/17/2019] [Accepted: 03/21/2019] [Indexed: 11/15/2022] Open
Abstract
Ribosome biogenesis (RiBi) is an extremely energy intensive process that is critical for gene expression. It is thus highly regulated, including through the tightly coordinated expression of over 200 RiBi genes by positive and negative transcriptional regulators. We investigated RiBi regulation as cells initiated meiosis in budding yeast and noted early transcriptional activation of RiBi genes, followed by their apparent translational repression 1 hour (h) after stimulation to enter meiosis. Surprisingly, in the representative genes examined, measured translational repression depended on their promoters rather than mRNA regions. Further investigation revealed that the signature of this regulation in our data depended on pre-treating cells with the translation inhibitor, cycloheximide (CHX). This treatment, at 1 h in meiosis, but not earlier, rapidly resulted in accumulation of RiBi mRNAs that were not translated. This effect was also seen in with CHX pre-treatment of cells grown in media lacking amino acids. For NSR1, this effect depended on the -150 to -101 region of the promoter, as well as the RiBi transcriptional repressors Dot6 and Tod6. Condition-specific RiBi mRNA accumulation was also seen with translation inhibitors that are dissimilar from CHX, suggesting that this phenomenon might represent a feedback response to global translation inhibition.
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Affiliation(s)
- Ze Cheng
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Gloria Ann Brar
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Szybowska P, Kostas M, Wesche J, Wiedlocha A, Haugsten EM. Cancer Mutations in FGFR2 Prevent a Negative Feedback Loop Mediated by the ERK1/2 Pathway. Cells 2019; 8:cells8060518. [PMID: 31146385 PMCID: PMC6627556 DOI: 10.3390/cells8060518] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/24/2019] [Accepted: 05/28/2019] [Indexed: 01/21/2023] Open
Abstract
Tight regulation of signaling from receptor tyrosine kinases is required for normal cellular functions and uncontrolled signaling can lead to cancer. Fibroblast growth factor receptor 2 (FGFR2) is a receptor tyrosine kinase that induces proliferation and migration. Deregulation of FGFR2 contributes to tumor progression and activating mutations in FGFR2 are found in several types of cancer. Here, we identified a negative feedback loop regulating FGFR2 signaling. FGFR2 stimulates the Ras/MAPK signaling pathway consisting of Ras-Raf-MEK1/2-ERK1/2. Inhibition of this pathway using a MEK1/2 inhibitor increased FGFR2 signaling. The putative ERK1/2 phosphorylation site at serine 780 (S780) in FGFR2 corresponds to serine 777 in FGFR1 which is directly phosphorylated by ERK1/2. Substitution of S780 in FGFR2 to an alanine also increased signaling. Truncated forms of FGFR2 lacking the C-terminal tail, including S780, have been identified in cancer and S780 has been found mutated to leucine in bladder cancer. Substituting S780 in FGFR2 with leucine increased FGFR2 signaling. Importantly, cells expressing these mutated versions of S780 migrated faster than cells expressing wild-type FGFR2. Thus, ERK1/2-mediated phosphorylation of S780 in FGFR2 constitutes a negative feedback loop and inactivation of this feedback loop in cancer cells causes hyperactivation of FGFR2 signaling, which may result in increased invasive properties.
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Affiliation(s)
- Patrycja Szybowska
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway.
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway.
| | - Michal Kostas
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway.
- Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway.
| | - Jørgen Wesche
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway.
- Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway.
| | - Antoni Wiedlocha
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway.
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway.
- Military Institute of Hygiene and Epidemiology, 01-163 Warsaw, Poland.
| | - Ellen Margrethe Haugsten
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway.
- Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway.
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Lehnert J, Khadra A. How Pulsatile Kisspeptin Stimulation and GnRH Autocrine Feedback Can Drive GnRH Secretion: A Modeling Investigation. Endocrinology 2019; 160:1289-1306. [PMID: 30874725 DOI: 10.1210/en.2018-00947] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/09/2019] [Indexed: 02/03/2023]
Abstract
Pulsatile secretion of GnRH from hypothalamic GnRH neurons tightly regulates the release of mammalian reproductive hormones. Although key factors such as electrical activity and stimulation by kisspeptin have been extensively studied, the underlying mechanisms that regulate GnRH release are still not fully understood. Previously developed mathematical models studied hormonal release and electrical properties of GnRH neurons separately, but they never integrated both components. Herein, we present a more complete biophysical model to investigate how electrical activity and hormonal release interact. The model consists of two components: an electrical submodel comprised of a modified Izhikevich formalism incorporating several key ionic currents to reproduce GnRH neuronal bursting behavior, and a hormonal submodel that incorporates pulsatile kisspeptin stimulation and a GnRH autocrine feedback mechanism. Using the model, we examine the electrical activity of GnRH neurons and how kisspeptin affects GnRH pulsatility. The model reproduces the noise-driven bursting behavior of GnRH neurons as well as the experimentally observed electrophysiological effects induced by GnRH and kisspeptin. Specifically, the model reveals that external application of GnRH causes a transient hyperpolarization followed by an increase in firing frequency, whereas administration of kisspeptin leads to long-lasting depolarization of the neuron. The model also shows that GnRH release follows a pulsatile profile similar to that observed experimentally and that kisspeptin and GnRH exhibit ∼7-1 locking in their pulsatility. These results suggest that external kisspeptin stimulation with a period of ∼8 minutes drives the autocrine mechanism beyond a threshold to generate pronounced GnRH pulses every hour.
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Affiliation(s)
- Jonas Lehnert
- Department of Quantitative Life Sciences, McGill University, Montreal, Quebec, Canada
| | - Anmar Khadra
- Department of Quantitative Life Sciences, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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Fu L, Yin J, Shi YB. Involvement of epigenetic modifications in thyroid hormone-dependent formation of adult intestinal stem cells during amphibian metamorphosis. Gen Comp Endocrinol 2019; 271:91-96. [PMID: 30472386 PMCID: PMC6322911 DOI: 10.1016/j.ygcen.2018.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 12/27/2022]
Abstract
Amphibian metamorphosis has long been used as model to study postembryonic development in vertebrates, a period around birth in mammals when many organs/tissues mature into their adult forms and is characterized by peak levels of plasma thyroid hormone (T3). Of particular interest is the remodeling of the intestine during metamorphosis. In the highly-related anurans Xenopus laevis and Xenopus tropicalis, this remodeling process involves larval epithelial cell death and de novo formation of adult stem cells via dedifferentiation of some larval cells under the induction of T3, making it a valuable system to investigate how adult organ-specific stem cells are formed during vertebrate development. Here, we will review some studies by us and others on how T3 regulates the formation of the intestinal stem cells during metamorphosis. We will highlight the involvement of nucleosome removal and a positive feedback mechanism involving the histone methyltransferases in gene regulation by T3 receptor (TR) during this process.
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Affiliation(s)
- Liezhen Fu
- Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), 49 Convent Dr., Bethesda, MD 20892, United States
| | - Jessica Yin
- Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), 49 Convent Dr., Bethesda, MD 20892, United States
| | - Yun-Bo Shi
- Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), 49 Convent Dr., Bethesda, MD 20892, United States.
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Alsiö J, Phillips BU, Sala-Bayo J, Nilsson SRO, Calafat-Pla TC, Rizwand A, Plumbridge JM, López-Cruz L, Dalley JW, Cardinal RN, Mar AC, Robbins TW. Dopamine D2-like receptor stimulation blocks negative feedback in visual and spatial reversal learning in the rat: behavioural and computational evidence. Psychopharmacology (Berl) 2019; 236:2307-2323. [PMID: 31218428 PMCID: PMC6695374 DOI: 10.1007/s00213-019-05296-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/02/2019] [Indexed: 02/02/2023]
Abstract
RATIONALE Dopamine D2-like receptors (D2R) are important drug targets in schizophrenia and Parkinson's disease, but D2R ligands also cause cognitive inflexibility such as poor reversal learning. The specific role of D2R in reversal learning remains unclear. OBJECTIVES We tested the hypotheses that D2R agonism impairs reversal learning by blocking negative feedback and that antagonism of D1-like receptors (D1R) impairs learning from positive feedback. METHODS Male Lister Hooded rats were trained on a novel visual reversal learning task. Performance on "probe trials", during which the correct or incorrect stimulus was presented with a third, probabilistically rewarded (50% of trials) and therefore intermediate stimulus, revealed individual learning curves for the processes of positive and negative feedback. The effects of D2R and D1R agonists and antagonists were evaluated. A separate cohort was tested on a spatial probabilistic reversal learning (PRL) task after D2R agonism. Computational reinforcement learning modelling was applied to choice data from the PRL task to evaluate the contribution of latent factors. RESULTS D2R agonism with quinpirole dose-dependently impaired both visual reversal and PRL. Analysis of the probe trials on the visual task revealed a complete blockade of learning from negative feedback at the 0.25 mg/kg dose, while learning from positive feedback was intact. Estimated parameters from the model that best described the PRL choice data revealed a steep and selective decrease in learning rate from losses. D1R antagonism had a transient effect on the positive probe trials. CONCLUSIONS D2R stimulation impairs reversal learning by blocking the impact of negative feedback.
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Affiliation(s)
- Johan Alsiö
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
| | - Benjamin U Phillips
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Júlia Sala-Bayo
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Simon R O Nilsson
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Neuroscience Institute, New York University Medical Center, New York, NY, USA
- Department of Neuroscience and Physiology, School of Medicine, New York University, New York, NY, USA
| | - Teresa C Calafat-Pla
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Arazo Rizwand
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Jessica M Plumbridge
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Laura López-Cruz
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Jeffrey W Dalley
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Rudolf N Cardinal
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Cambridgeshire & Peterborough NHS Foundation Trust, Box 190 (Liaison Psychiatry), Cambridge Biomedical Campus, Cambridge, UK
| | - Adam C Mar
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Neuroscience Institute, New York University Medical Center, New York, NY, USA
- Department of Neuroscience and Physiology, School of Medicine, New York University, New York, NY, USA
| | - Trevor W Robbins
- Department of Psychology and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
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Sriram K. Bifurcation analysis of insulin regulated mTOR signalling pathway in cancer cells. IET Syst Biol 2018; 12:205-212. [PMID: 30259865 PMCID: PMC8687200 DOI: 10.1049/iet-syb.2018.0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/01/2018] [Accepted: 04/12/2018] [Indexed: 11/19/2022] Open
Abstract
Insulin induced mTOR signalling pathway is a complex network implicated in many types of cancers. The molecular mechanism of this pathway is highly complex and the dynamics is tightly regulated by intricate positive and negative feedback loops. In breast cancer cell lines, metformin has been shown to induce phosphorylation at specific serine sites in insulin regulated substrate of mTOR pathway that results in apoptosis over cell proliferation. The author models and performs bifurcation analysis to simulate cell proliferation and apoptosis in mTOR signalling pathway to capture the dynamics both in the presence and absence of metformin in cancer cells. Metformin is shown to negatively regulate PI3K through AMPK induced IRS1 phosphorylation and this brings about a reversal of AKT bistablity in codimension-1 bifurcation diagram from S-shaped, related to cell proliferation in the absence of drug metformin, to Z-shaped, related to apoptosis in the presence of drug metformin. The author hypothesises and explains how this negative regulation acts a circuit breaker, as a result of which mTOR network favours apoptosis of cancer cells over its proliferation. The implication of reversing the shape of bistable dynamics from S to Z or vice-versa in biological networks in general is discussed.
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Affiliation(s)
- Krishnamachari Sriram
- Centre for Computational Biology, Indraprastha Institute of Information Technology-Delhi, Okhla Phase-III, New Delhi, India.
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30
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Imaizumi T, Sassa N, Kawaguchi S, Matsumiya T, Yoshida H, Seya K, Shiratori T, Hirono K, Tanaka H. Interferon-stimulated gene 60 (ISG60) constitutes a negative feedback loop in the downstream of TLR3 signaling in hCMEC/D3 cells. J Neuroimmunol 2018; 324:16-21. [PMID: 30195920 DOI: 10.1016/j.jneuroim.2018.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 08/18/2018] [Accepted: 08/31/2018] [Indexed: 12/21/2022]
Abstract
Brain capillary endothelial cells are the component of blood brain barrier, and the first line of defense against viruses invading into brain. We demonstrate that treatment of hCMEC/D3 cells, a human brain capillary endothelial cell line, with a Toll-like receptor 3 (TLR3) agonist polyinosinic-polycytidylic acid (poly IC) induces the expression of interferon (IFN)-stimulated gene 60 (ISG60), and this reaction was mediated by IFN-β. Knockdown of ISG60 increased the poly IC-induced expression of IFN-β and an IFN-β-inducible chemokine CXCL10. This indicates that ISG60 constitutes a negative feedback loop in the downstream of TLR3/IFN-β. ISG60 in brain capillary endothelial cells may contribute to prevent excess immune reactions associated with viral infections.
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Affiliation(s)
- Tadaatsu Imaizumi
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
| | - Naoko Sassa
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Shogo Kawaguchi
- Department of Gastroenterology and Hematology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Tomoh Matsumiya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Hidemi Yoshida
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Kazuhiko Seya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Toshihiro Shiratori
- Department of Respiratory Medicine, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Koji Hirono
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Hiroshi Tanaka
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan; Department of School Health Science, Hirosaki University Faculty of Education, Hirosaki 036-8560, Japan
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31
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Fedosejevs ET, Feil R, Lunn JE, Plaxton WC. The signal metabolite trehalose-6-phosphate inhibits the sucrolytic activity of sucrose synthase from developing castor beans. FEBS Lett 2018; 592:2525-2532. [PMID: 30025148 DOI: 10.1002/1873-3468.13197] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 01/06/2023]
Abstract
In plants, trehalose 6-phosphate (T6P) is a key signaling metabolite that functions as both a signal and negative feedback regulator of sucrose levels. The mode of action by which T6P senses and regulates sucrose is not fully understood. Here, we demonstrate that the sucrolytic activity of RcSUS1, the dominant sucrose synthase isozyme expressed in developing castor beans, is allosterically inhibited by T6P. The feedback inhibition of SUS by T6P may contribute to the control of sink strength and sucrolytic flux in heterotrophic plant tissues.
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Affiliation(s)
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - William C Plaxton
- Department of Biology, Queen's University, Kingston, Canada
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
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32
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Nett IR, Mulas C, Gatto L, Lilley KS, Smith A. Negative feedback via RSK modulates Erk-dependent progression from naïve pluripotency. EMBO Rep 2018; 19:e45642. [PMID: 29895711 PMCID: PMC6073214 DOI: 10.15252/embr.201745642] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/16/2018] [Accepted: 05/18/2018] [Indexed: 01/08/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signalling is implicated in initiation of embryonic stem (ES) cell differentiation. The pathway is subject to complex feedback regulation. Here, we examined the ERK-responsive phosphoproteome in ES cells and identified the negative regulator RSK1 as a prominent target. We used CRISPR/Cas9 to create combinatorial mutations in RSK family genes. Genotypes that included homozygous null mutations in Rps6ka1, encoding RSK1, resulted in elevated ERK phosphorylation. These RSK-depleted ES cells exhibit altered kinetics of transition into differentiation, with accelerated downregulation of naïve pluripotency factors, precocious expression of transitional epiblast markers and early onset of lineage specification. We further show that chemical inhibition of RSK increases ERK phosphorylation and expedites ES cell transition without compromising multilineage potential. These findings demonstrate that the ERK activation profile influences the dynamics of pluripotency progression and highlight the role of signalling feedback in temporal control of cell state transitions.
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Affiliation(s)
- Isabelle Re Nett
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Carla Mulas
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Laurent Gatto
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK
- Computational Proteomics Unit, Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK
| | - Kathryn S Lilley
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Austin Smith
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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Hvas CL, Ott P, Paine P, Lal S, Jørgensen SP, Dahlerup JF. Obeticholic acid for severe bile acid diarrhea with intestinal failure: A case report and review of the literature. World J Gastroenterol 2018; 24:2320-2326. [PMID: 29881241 PMCID: PMC5989246 DOI: 10.3748/wjg.v24.i21.2320] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/08/2018] [Accepted: 03/30/2018] [Indexed: 02/06/2023] Open
Abstract
Bile acid diarrhea results from excessive amounts of bile acids entering the colon due to hepatic overexcretion of bile acids or bile acid malabsorption in the terminal ileum. The main therapies include bile acid sequestrants, such as colestyramine and colesevelam, which may be given in combination with the opioid receptor agonist loperamide. Some patients are refractory to conventional treatments. We report the use of the farnesoid X receptor agonist obeticholic acid in a patient with refractory bile acid diarrhea and subsequent intestinal failure. A 32-year-old woman with quiescent colonic Crohn’s disease and a normal terminal ileum had been diagnosed with severe bile acid malabsorption and complained of watery diarrhea and fatigue. The diarrhea resulted in hypokalemia and sodium depletion that made her dependent on twice weekly intravenous fluid and electrolyte infusions. Conventional therapies with colestyramine, colesevelam, and loperamide had no effect. Second-line antisecretory therapies with pantoprazole, liraglutide, and octreotide also failed. Third-line treatment with obeticholic acid reduced the number of stools from an average of 13 to an average of 7 per 24 h and improved the patient’s quality of life. The fluid and electrolyte balances normalized. The effect was sustained during follow-up for 6 mo with treatment at a daily dosage of 25 mg. The diarrhea worsened shortly after cessation of obeticholic acid. This case report supports the initial report that obeticholic acid may reduce bile acid production and improve symptoms in patients with bile acid diarrhea.
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Affiliation(s)
- Christian Lodberg Hvas
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus C 8000, Denmark
| | - Peter Ott
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus C 8000, Denmark
| | - Peter Paine
- Department of Gastroenterology, Salford Royal NHS Foundation Trust, Salford, Manchester M6 8HD, United Kingdom
| | - Simon Lal
- Department of Gastroenterology, Salford Royal NHS Foundation Trust, Salford, Manchester M6 8HD, United Kingdom
| | - Søren Peter Jørgensen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus C 8000, Denmark
| | - Jens Frederik Dahlerup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus C 8000, Denmark
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34
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Flores-Sandoval E, Eklund DM, Hong SF, Alvarez JP, Fisher TJ, Lampugnani ER, Golz JF, Vázquez-Lobo A, Dierschke T, Lin SS, Bowman JL. Class C ARFs evolved before the origin of land plants and antagonize differentiation and developmental transitions in Marchantia polymorpha. New Phytol 2018; 218:1612-1630. [PMID: 29574879 DOI: 10.1111/nph.15090] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 02/05/2018] [Indexed: 05/08/2023]
Abstract
A plethora of developmental and physiological processes in land plants is influenced by auxin, to a large extent via alterations in gene expression by AUXIN RESPONSE FACTORs (ARFs). The canonical auxin transcriptional response system is a land plant innovation, however, charophycean algae possess orthologues of at least some classes of ARF and AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) genes, suggesting that elements of the canonical land plant system existed in an ancestral alga. We reconstructed the phylogenetic relationships between streptophyte ARF and AUX/IAA genes and functionally characterized the solitary class C ARF, MpARF3, in Marchantia polymorpha. Phylogenetic analyses indicate that multiple ARF classes, including class C ARFs, existed in an ancestral alga. Loss- and gain-of-function MpARF3 alleles result in pleiotropic effects in the gametophyte, with MpARF3 inhibiting differentiation and developmental transitions in multiple stages of the life cycle. Although loss-of-function Mparf3 and Mpmir160 alleles respond to exogenous auxin treatments, strong miR-resistant MpARF3 alleles are auxin-insensitive, suggesting that class C ARFs act in a context-dependent fashion. We conclude that two modules independently evolved to regulate a pre-existing ARF transcriptional network. Whereas the auxin-TIR1-AUX/IAA pathway evolved to repress class A/B ARF activity, miR160 evolved to repress class C ARFs in a dynamic fashion.
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Affiliation(s)
- Eduardo Flores-Sandoval
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - D Magnus Eklund
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Syuan-Fei Hong
- Institute of Biotechnology, National Taiwan University, 81, Chang-Xing ST., Taipei, 106, Taiwan
| | - John P Alvarez
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Tom J Fisher
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Edwin R Lampugnani
- School of BioSciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - John F Golz
- School of BioSciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Alejandra Vázquez-Lobo
- CIByC, Universidad Autónoma del Estado de Morelos, Av. Universidad No. 1001, Colonia Chamilpa, CP 62209, Cuernavaca, Morelos, México
| | - Tom Dierschke
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, 81, Chang-Xing ST., Taipei, 106, Taiwan
| | - John L Bowman
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
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Helfer P, Shultz TR. Coupled feedback loops maintain synaptic long-term potentiation: A computational model of PKMzeta synthesis and AMPA receptor trafficking. PLoS Comput Biol 2018; 14:e1006147. [PMID: 29813048 PMCID: PMC5993340 DOI: 10.1371/journal.pcbi.1006147] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 06/08/2018] [Accepted: 04/16/2018] [Indexed: 01/13/2023] Open
Abstract
In long-term potentiation (LTP), one of the most studied types of neural plasticity, synaptic strength is persistently increased in response to stimulation. Although a number of different proteins have been implicated in the sub-cellular molecular processes underlying induction and maintenance of LTP, the precise mechanisms remain unknown. A particular challenge is to demonstrate that a proposed molecular mechanism can provide the level of stability needed to maintain memories for months or longer, in spite of the fact that many of the participating molecules have much shorter life spans. Here we present a computational model that combines simulations of several biochemical reactions that have been suggested in the LTP literature and show that the resulting system does exhibit the required stability. At the core of the model are two interlinked feedback loops of molecular reactions, one involving the atypical protein kinase PKMζ and its messenger RNA, the other involving PKMζ and GluA2-containing AMPA receptors. We demonstrate that robust bistability-stable equilibria both in the synapse's potentiated and unpotentiated states-can arise from a set of simple molecular reactions. The model is able to account for a wide range of empirical results, including induction and maintenance of late-phase LTP, cellular memory reconsolidation and the effects of different pharmaceutical interventions.
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Affiliation(s)
- Peter Helfer
- Department of Psychology and Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Thomas R. Shultz
- Department of Psychology and School of Computer Science, McGill University, Montreal, Quebec, Canada
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36
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Tiwari MN, Mohan S, Biala Y, Yaari Y. Differential contributions of Ca 2+ -activated K + channels and Na + /K + -ATPases to the generation of the slow afterhyperpolarization in CA1 pyramidal cells. Hippocampus 2018; 28:338-357. [PMID: 29431274 PMCID: PMC5947627 DOI: 10.1002/hipo.22836] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/17/2017] [Accepted: 02/05/2018] [Indexed: 12/13/2022]
Abstract
In many types of CNS neurons, repetitive spiking produces a slow afterhyperpolarization (sAHP), providing sustained, intrinsically generated negative feedback to neuronal excitation. Changes in the sAHP have been implicated in learning behaviors, in cognitive decline in aging, and in epileptogenesis. Despite its importance in brain function, the mechanisms generating the sAHP are still controversial. Here we have addressed the roles of M-type K+ current (IM ), Ca2+ -gated K+ currents (ICa(K) 's) and Na+ /K+ -ATPases (NKAs) current to sAHP generation in adult rat CA1 pyramidal cells maintained at near-physiological temperature (35 °C). No evidence for IM contribution to the sAHP was found in these neurons. Both ICa(K) 's and NKA current contributed to sAHP generation, the latter being the predominant generator of the sAHP, particularly when evoked with short trains of spikes. Of the different NKA isoenzymes, α1 -NKA played the key role, endowing the sAHP a steep voltage-dependence. Thus normal and pathological changes in α1 -NKA expression or function may affect cognitive processes by modulating the inhibitory efficacy of the sAHP.
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Affiliation(s)
- Manindra Nath Tiwari
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Sandesh Mohan
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Yoav Biala
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Yoel Yaari
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
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37
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Howes JE, Akan DT, Burns MC, Rossanese OW, Waterson AG, Fesik SW. Small Molecule-Mediated Activation of RAS Elicits Biphasic Modulation of Phospho-ERK Levels that Are Regulated through Negative Feedback on SOS1. Mol Cancer Ther 2018; 17:1051-1060. [PMID: 29440291 DOI: 10.1158/1535-7163.mct-17-0666] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 12/11/2017] [Accepted: 01/11/2018] [Indexed: 11/16/2022]
Abstract
Oncogenic mutation of RAS results in aberrant cellular signaling and is responsible for more than 30% of all human tumors. Therefore, pharmacologic modulation of RAS has attracted great interest as a therapeutic strategy. Our laboratory has recently discovered small molecules that activate Son of Sevenless (SOS)-catalyzed nucleotide exchange on RAS and inhibit downstream signaling. Here, we describe how pharmacologically targeting SOS1 induced biphasic modulation of RAS-GTP and ERK phosphorylation levels, which we observed in a variety of cell lines expressing different RAS-mutant isoforms. We show that compound treatment caused an increase in phosphorylation at ERK consensus motifs on SOS1 that was not observed with the expression of a non-phosphorylatable S1178A SOS1 mutant or after pretreatment with an ERK inhibitor. Phosphorylation at S1178 on SOS1 is known to inhibit the association between SOS1 and GRB2 and disrupt SOS1 membrane localization. Consistent with this, we show that wild-type SOS1 and GRB2 dissociated in a time-dependent fashion in response to compound treatment, and conversely, this interaction was enhanced with the expression of an S1178A SOS1 mutant. Furthermore, in cells expressing either S1178A SOS1 or a constitutively membrane-bound CAAX box tagged SOS1 mutant, we observed elevated RAS-GTP levels over time in response to compound, as compared with the biphasic changes in RAS-GTP exhibited in cells expressing wild-type SOS1. These results suggest that small molecule targeting of SOS1 can elicit a biphasic modulation of RAS-GTP and phospho-ERK levels through negative feedback on SOS1 that regulates the interaction between SOS1 and GRB2. Mol Cancer Ther; 17(5); 1051-60. ©2018 AACR.
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Affiliation(s)
- Jennifer E Howes
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | - Denis T Akan
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | - Michael C Burns
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | | | - Alex G Waterson
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | - Stephen W Fesik
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee.
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Silva MS, Prescott M, Campbell RE. Ontogeny and reversal of brain circuit abnormalities in a preclinical model of PCOS. JCI Insight 2018; 3:99405. [PMID: 29618656 DOI: 10.1172/jci.insight.99405] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/28/2018] [Indexed: 12/31/2022] Open
Abstract
Androgen excess is a hallmark of polycystic ovary syndrome (PCOS), a prevalent yet poorly understood endocrine disorder. Evidence from women and preclinical animal models suggests that elevated perinatal androgens can elicit PCOS onset in adulthood, implying androgen actions in both PCOS ontogeny and adult pathophysiology. Prenatally androgenized (PNA) mice exhibit a robust increase of progesterone-sensitive GABAergic inputs to gonadotropin-releasing hormone (GnRH) neurons implicated in the pathogenesis of PCOS. It is unclear when altered GABAergic wiring develops in the brain, and whether these central abnormalities are dependent upon adult androgen excess. Using GnRH-GFP-transgenic mice, we determined that increased GABA input to GnRH neurons occurs prior to androgen excess and the manifestation of reproductive impairments in PNA mice. These data suggest that brain circuit abnormalities precede the postpubertal development of PCOS traits. Despite the apparent developmental programming of circuit abnormalities, long-term blockade of androgen receptor signaling from early adulthood rescued normal GABAergic wiring onto GnRH neurons, improved ovarian morphology, and restored reproductive cycles in PNA mice. Therefore, androgen excess maintains changes in female brain wiring linked to PCOS features and the blockade of androgen receptor signaling reverses both the central and peripheral PNA-induced PCOS phenotype.
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Steinberg GR. Cellular Energy Sensing and Metabolism-Implications for Treating Diabetes: The 2017 Outstanding Scientific Achievement Award Lecture. Diabetes 2018; 67:169-179. [PMID: 29358486 DOI: 10.2337/dbi17-0039] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/08/2017] [Indexed: 11/13/2022]
Abstract
The Outstanding Scientific Achievement Award recognizes distinguished scientific achievement in the field of diabetes, taking into consideration independence of thought and originality. Gregory R. Steinberg, PhD, professor of medicine, Canada Research Chair, J. Bruce Duncan Endowed Chair in Metabolic Diseases, and codirector of the Metabolism and Childhood Obesity Research Program at McMaster University, Hamilton, Ontario, Canada, received the prestigious award at the American Diabetes Association's 77th Scientific Sessions, 9-13 June 2017, in San Diego, CA. He presented the Outstanding Scientific Achievement Award Lecture, "Cellular Energy Sensing and Metabolism-Implications for Treating Diabetes," on Monday, 12 June 2017.The survival of all cells is dependent on the constant challenge to match energetic demands with nutrient availability, a task that is mediated through a highly conserved network of metabolic fuel sensors that orchestrate both cellular and whole-organism energy balance. A mismatch between cellular energy demand and nutrient availability is a key factor contributing to the development of type 2 diabetes; thus, understanding the fundamental mechanisms by which cells sense nutrient availability and demand may lead to the development of new treatments. Glucose-lowering therapies, such as caloric restriction, exercise, and metformin, all induce an energetic challenge that results in the activation of the cellular energy sensor AMP-activated protein kinase (AMPK). Activation of AMPK in turn suppresses lipid synthesis and inflammation while increasing glucose uptake, fatty acid oxidation, and mitochondrial function. In contrast, high levels of nutrient availability suppress AMPK activity while also increasing the production of peripheral serotonin, a gut-derived endocrine factor that suppresses β-adrenergic-induced activation of brown adipose tissue. Identifying new ways to manipulate these two ancient fuel gauges by activating AMPK and inhibiting peripheral serotonin may lead to the development of new therapies for treating type 2 diabetes.
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MESH Headings
- AMP-Activated Protein Kinases/metabolism
- Adipose Tissue, Beige/drug effects
- Adipose Tissue, Beige/metabolism
- Adipose Tissue, Beige/pathology
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, Brown/pathology
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/metabolism
- Adipose Tissue, White/pathology
- Animals
- Awards and Prizes
- Caloric Restriction
- Cell Survival/drug effects
- Combined Modality Therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/prevention & control
- Diabetes Mellitus, Type 2/therapy
- Endocrinology
- Energy Intake/drug effects
- Energy Metabolism/drug effects
- Enzyme Activation/drug effects
- Exercise
- Feedback, Physiological/drug effects
- Humans
- Hypoglycemic Agents/therapeutic use
- Insulin Resistance
- Liver/drug effects
- Liver/metabolism
- Liver/pathology
- Models, Biological
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Serotonin/blood
- Serotonin/metabolism
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Affiliation(s)
- Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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Lundgren JA, Kim SH, Burt Solorzano CM, McCartney CR, Marshall JC. Progesterone Suppression of Luteinizing Hormone Pulse Frequency in Adolescent Girls With Hyperandrogenism: Effects of Metformin. J Clin Endocrinol Metab 2018; 103:263-270. [PMID: 29095983 PMCID: PMC5761484 DOI: 10.1210/jc.2017-02068] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 10/23/2017] [Indexed: 11/19/2022]
Abstract
CONTEXT Polycystic ovary syndrome (PCOS) and adolescent hyperandrogenism (HA) are characterized by rapid luteinizing hormone (LH) pulse frequency. This partly reflects impaired gonadotropin-releasing hormone pulse generator (hypothalamic) sensitivity to progesterone (P4) negative feedback. We assessed whether metformin may improve P4 sensitivity in adolescent HA, for which it is prescribed widely. OBJECTIVE To test the hypothesis that metformin improves hypothalamic P4 sensitivity in adolescent HA. DESIGN Nonrandomized, interventional trial. SETTING Academic clinical research unit. PARTICIPANTS Ten adolescent girls with HA. INTERVENTION The girls underwent LH sampling every 10 minutes for 11 hours, at study baseline and after 7 days of oral P4 and estradiol (E2). Participants then took metformin (1 g twice daily) for 9.4 to 13.7 weeks, after which participants again underwent frequent LH sampling before and after 7 days of oral P4 and E2 (while continuing metformin). Total and free testosterone (T) and fasting insulin were assessed at each admission. At admissions 1 and 3, 2-hour oral glucose tolerance tests were performed. MAIN OUTCOME MEASURE Metformin-related change in hypothalamic P4 sensitivity index [percent change in LH pulse frequency (before vs after P4 and E2) divided by day 7 P4 level]. RESULTS Free T levels decreased by 29% with metformin (P = 0.0137). Measures of hyperinsulinemia and P4 sensitivity index did not significantly change with metformin use. CONCLUSION Short-term metformin use improved biochemical hyperandrogenemia, but did not improve hypothalamic sensitivity to P4 suppression, in adolescent girls.
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Affiliation(s)
- Jessica A. Lundgren
- The Center for Research in Reproduction, University of Virginia Health System, Charlottesville, Virginia 22908
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Su Hee Kim
- The Center for Research in Reproduction, University of Virginia Health System, Charlottesville, Virginia 22908
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Christine M. Burt Solorzano
- The Center for Research in Reproduction, University of Virginia Health System, Charlottesville, Virginia 22908
- Department of Pediatrics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Christopher R. McCartney
- The Center for Research in Reproduction, University of Virginia Health System, Charlottesville, Virginia 22908
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia 22908
| | - John C. Marshall
- The Center for Research in Reproduction, University of Virginia Health System, Charlottesville, Virginia 22908
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia 22908
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Liang X, Hou X, Yang Y, Liu H, Guo R, Yang Z, Yang L. The feedback loop of "EMMPRIN/NF-κB" worsens atherosclerotic plaque via suppressing autophagy in macrophage. J Mol Cell Cardiol 2017; 114:129-140. [PMID: 29154780 DOI: 10.1016/j.yjmcc.2017.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 11/07/2017] [Accepted: 11/12/2017] [Indexed: 01/12/2023]
Abstract
This study examined the significance of macrophage autophagy in extracellular matrix metalloproteinase inducer (EMMPRIN)-mediated atherosclerosis (AS). Apolipoprotein E-deficient (ApoE-/-) mice were fed a western diet to establish an AS model. EMMPRIN and p62/Sequestosome-1(SQSTM1) expression were evaluated in plaque macrophages from the AS mice using immunofluorescence. The EMMPRIN and p62/SQSTM1 protein expression levels in macrophages increased with the increasing vulnerability of the atherosclerotic plaques. RAW264.7 cells and ApoE-/- mice Bone Marrow-derived macrophages were transfected with different small interfering RNAs (siRNAs) or plasmids, or treated with different drugs in the presence or absence of oxidized low-density lipoprotein (oxLDL). The protein levels of the targets were evaluated using western blotting (WB), and the autophagosomes were observed under a transmission electron microscope (TEM). Over-expressed EMMPRIN dramatically inhibited oxLDL-mediated autophagy. EMMPRIN also negatively regulated autophagy primarily through the nuclear factor-kappa B (NF-κB) signalling pathway. In turn, activated NF-κB up-regulated EMMPRIN expression. Inhibition of EMMPRIN decreased cell apoptosis and the release of inflammatory cytokines via the promotion of macrophage autophagy. Infection with an adenovirus delivering the EMMPRIN-siRNA ameliorated AS, promoted macrophage autophagy in plaques and reduced the serum TNF-α, IL-6, MCP-1 and NF-κB expression levels in the AS mice. Chloroquine (CQ) reversed these effects. This study revealed for the first time that the feedback loop of the "EMMPRIN/NF-κB" pathway plays an important role in atherosclerotic plaques via modulation of autophagy in macrophages, which might provide a potential strategy for the clinical treatment of AS.
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Affiliation(s)
- Xing Liang
- Department of Postgraduate, Third Military Medical University, Chongqing 400038,China; Department of Cardiology, Kunming General Hospital of Chengdu Military Area, Yunnan 650032, China
| | - Xianhua Hou
- Department of Neurology, Southwestern Hospital, Third Military Medical University, Chongqing 400038, China
| | - Yang Yang
- Chongqing Blood Centre, Institute of blood transfusion, Chongqing 400000, China
| | - Hong Liu
- Department of Cardiology, Affiliated Hospital of Dali University Dali University School of Clinical Medicine, Yunnan, 671000, China
| | - Ruiwei Guo
- Department of Cardiology, Kunming General Hospital of Chengdu Military Area, Yunnan 650032, China
| | - Zhihua Yang
- Department of Cardiology, Kunming General Hospital of Chengdu Military Area, Yunnan 650032, China
| | - Lixia Yang
- Department of Cardiology, Kunming General Hospital of Chengdu Military Area, Yunnan 650032, China.
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Kraynak M, Flowers MT, Shapiro RA, Kapoor A, Levine JE, Abbott DH. Extraovarian gonadotropin negative feedback revealed by aromatase inhibition in female marmoset monkeys. Am J Physiol Endocrinol Metab 2017; 313:E507-E514. [PMID: 28679622 PMCID: PMC5792143 DOI: 10.1152/ajpendo.00058.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/09/2017] [Accepted: 06/27/2017] [Indexed: 12/23/2022]
Abstract
Whereas the ovary produces the majority of estradiol (E2) in mature female primates, extraovarian sources contribute to E2 synthesis and action, including the brain E2-regulating hypothalamic gonadotropin-releasing hormone. In ovary-intact female rodent models, aromatase inhibition (AI) induces a polycystic ovary syndrome-like hypergonadotropic hyperandrogenism due to absent E2-mediated negative feedback. To examine the role of extraovarian E2 on nonhuman primate gonadotropin regulation, the present study uses letrozole to elicit AI in adult female marmoset monkeys. Sixteen female marmosets (Callithrix jacchus; >2 yr) were randomly assigned to ovary-intact or ovariectomy (OVX) conditions and subsequently placed on a daily oral regimen of either ~200 µl vehicle alone (ovary-intact Control, n = 3; OVX, n = 3) or 1 mg ⋅ kg-1 ⋅ day-1 letrozole in vehicle (ovary-intact AI, n = 4; OVX + AI, n = 6). Blood samples were collected every 10 days, and plasma chorionic gonadotropin (CG) and steroid hormone levels were determined by validated radioimmunoassay and liquid chromatography/tandem mass spectrometry, respectively. Ovary-intact, AI-treated and OVX females exhibited elevated CG (P < 0.01, P = 0.004, respectively) compared with controls, and after 30 days, OVX + AI females exhibited a suprahypergonadotropic phenotype (P = 0.004) compared with ovary-intact + AI and OVX females. Androstenedione (P = 0.03) and testosterone (P = 0.05) were also elevated in ovary-intact, AI-treated females above all other groups. The current study thus confirms in a nonhuman primate that E2 depletion and diminished negative feedback in ovary-intact females engage hypergonadotropic hyperandrogenism. Additionally, we demonstrate that extraovarian estrogens, possibly neuroestrogens, contribute to female negative feedback regulation of gonadotropin release.
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Affiliation(s)
- Marissa Kraynak
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, Wisconsin;
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Matthew T Flowers
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin; and
| | - Robert A Shapiro
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin; and
| | - Amita Kapoor
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jon E Levine
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin; and
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - David H Abbott
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin
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Gordon RE, Zhang L, Yang ZJ. Restore the brake on tumor progression. Biochem Pharmacol 2017; 138:1-6. [PMID: 28389227 DOI: 10.1016/j.bcp.2017.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/03/2017] [Indexed: 11/19/2022]
Abstract
Sonic hedgehog (Shh) signaling plays a key role in regulation of normal development. The negative feedback mechanism mediated by the transcriptional factor, Gli3, acts to finely tune Shh signaling, providing tight control of normal developmental processes. Hyperactivation of Shh signaling often leads to many human malignancies, including basal cell carcinoma and medulloblastoma (MB). However, how tumor cells sustain the aberrant activation of Shh signaling is still not completely understood. We recently revealed that during MB formation, tumor cells express Nestin, a type VI intermediate filament protein, which maintains uncontrolled Shh signaling by abolishing negative feedback by Gli3. Therefore, Nestin expression is a necessary step for MB formation. These findings highlight the novel function of Nestin in regulating Shh signaling, as well as the important role of a disrupted negative feedback mechanism in MB tumorigenesis. Further, restoration of the intrinsic negative feedback by repressing Nestin expression represents a promising approach to treat MB as well as other Shh signaling associated malignancies.
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Affiliation(s)
- Renata E Gordon
- Cancer Biology Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Li Zhang
- Laboratory of Molecular Neuropathology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
| | - Zeng-Jie Yang
- Cancer Biology Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA; Laboratory of Molecular Neuropathology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China.
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Qi X, Zhou W, Wang Q, Guo L, Lu D, Lin H. Gonadotropin-Inhibitory Hormone, the Piscine Ortholog of LPXRFa, Participates in 17β-Estradiol Feedback in Female Goldfish Reproduction. Endocrinology 2017; 158:860-873. [PMID: 28324026 DOI: 10.1210/en.2016-1550] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/27/2016] [Indexed: 02/08/2023]
Abstract
Gonadotropin-inhibitory hormone (GnIH) plays a critical role in regulating gonadotropin-releasing hormone, gonadotropin hormone, and steroidogenesis in teleosts. In the present study, we sought to determine whether 17β-estradiol (E2) acts directly on GnIH neurons to regulate reproduction in goldfish, a seasonal breeder, and we investigated the role of estrogen receptors (ERs) in mediating this process. We found that GnIH neurons coexpress three types of ERs. Ovariectomy and letrozole implantation into female goldfish at the vitellogenic stage elicited a substantial decrease in the expression of GnIH messenger RNA (mRNA), and E2 supplementation abolished this effect. In primary cultured hypothalamus cells, E2 increased GnIH mRNA levels; surprisingly, selective ERα and ERβ agonists showed opposite effects in regulating GnIH mRNA levels. Using genome walking, we isolated a 2329-bp section of the GnIH promoter sequence, and 7 half-estrogen response elements (EREs) were found in the promoter region. Luciferase assays and electrophoretic mobility shift assay results show that the half-ERE element at -2203 is the key site for competitive binding between ERα and ERβ. Ovariectomy and letrozole implantation into female goldfish in the maturating stage did not change the GnIH mRNA expression levels. Taken together, these findings suggest that E2 binds to multiple types of ERs, which competitively bind to the same half-ERE binding site of the GnIH promoter to achieve both positive and negative feedback in response to estrogen to regulate goldfish reproduction at different stages of ovarian development.
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Affiliation(s)
- Xin Qi
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wenyi Zhou
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Qingqing Wang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Liang Guo
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Danqi Lu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Haoran Lin
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Masko EM, Alfaqih MA, Solomon KR, Barry WT, Newgard CB, Muehlbauer MJ, Valilis NA, Phillips TE, Poulton SH, Freedland AR, Sun S, Dambal SK, Sanders SE, Macias E, Freeman MR, Dewhirst MW, Pizzo SV, Freedland SJ. Evidence for Feedback Regulation Following Cholesterol Lowering Therapy in a Prostate Cancer Xenograft Model. Prostate 2017; 77:446-457. [PMID: 27900797 PMCID: PMC5822711 DOI: 10.1002/pros.23282] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 11/04/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND Epidemiologic data suggest cholesterol-lowering drugs may prevent the progression of prostate cancer, but not the incidence of the disease. However, the association of combination therapy in cholesterol reduction on prostate or any cancer is unclear. In this study, we compared the effects of the cholesterol lowering drugs simvastatin and ezetimibe alone or in combination on the growth of LAPC-4 prostate cancer in vivo xenografts. METHODS Proliferation assays were conducted by MTS solution and assessed by Student's t-test. 90 male nude mice were placed on a high-cholesterol Western-diet for 7 days then injected subcutaneously with 1 × 105 LAPC-4 cells. Two weeks post-injection, mice were randomized to control, 11 mg/kg/day simvastatin, 30 mg/kg ezetimibe, or the combination and sacrificed 42 days post-randomization. We used a generalized linear model with the predictor variables of treatment, time, and treatment by time (i.e., interaction term) with tumor volume as the outcome variable. Total serum and tumor cholesterol were measured. Tumoral RNA was extracted and cDNA synthesized from 1 ug of total RNA for quantitative real-time PCR. RESULTS Simvastatin directly reduced in vitro prostate cell proliferation in a dose-dependent, cell line-specific manner, but ezetimibe had no effect. In vivo, low continuous dosing of ezetimibe, delivered by food, or simvastatin, delivered via an osmotic pump had no effect on tumor growth compared to control mice. In contrast, dual treatment of simvastatin and ezetimibe accelerated tumor growth. Ezetimibe significantly lowered serum cholesterol by 15%, while simvastatin had no effect. Ezetimibe treatment resulted in higher tumor cholesterol. A sixfold induction of low density lipoprotein receptor mRNA was observed in ezetimibe and the combination with simvastatin versus control tumors. CONCLUSIONS Systemic cholesterol lowering by ezetimibe did not slow tumor growth, nor did the cholesterol independent effects of simvastatin and the combined treatment increased tumor growth. Despite lower serum cholesterol, tumors from ezetimibe treated mice had higher levels of cholesterol. This study suggests that induction of low density lipoprotein receptor is a possible mechanism of resistance that prostate tumors use to counteract the therapeutic effects of lowering serum cholesterol. Prostate 77:446-457, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Elizabeth M. Masko
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Mahmoud A. Alfaqih
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Keith R. Solomon
- Department of Orthopedic Surgery, Harvard Medical School, Boston, Massachusetts
| | - William T. Barry
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina
| | - Christopher B. Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, North Carolina
| | - Michael J. Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, North Carolina
| | - Nikolaos A. Valilis
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Tameika E. Phillips
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Susan H. Poulton
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Alexis R. Freedland
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
| | - Stephanie Sun
- Department of Surgery, Durham Veterans Administration Hospital, Durham, North Carolina
| | - Shweta K. Dambal
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
| | - Sergio E. Sanders
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
| | - Everardo Macias
- Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
| | - Michael R. Freeman
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
| | - Mark W. Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina
| | - Salvatore V. Pizzo
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Stephen J. Freedland
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Surgery, Durham Veterans Administration Hospital, Durham, North Carolina
- Correspondence to: Dr. Stephen Freedland, Division of Urology, Department of Surgery, Cedars Sinai Medical Center, 8635 West 3rd Street Suite 1070W, Los Angeles, CA 90048.
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Li J, Zhou Q, Ma Z, Wang M, Shen WJ, Azhar S, Guo Z, Hu Z. Feedback inhibition of CREB signaling by p38 MAPK contributes to the negative regulation of steroidogenesis. Reprod Biol Endocrinol 2017; 15:19. [PMID: 28302174 PMCID: PMC5356319 DOI: 10.1186/s12958-017-0239-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/06/2017] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Steroidogenesis is a complex, multi-steps biological process in which, cholesterol precursor is converted to steroids in a tissue specific and tropic hormone dependent manner. Given that steroidogenesis is achieved by coordinated functioning of multiple tissue specific enzymes, many steroids intermediates/metabolites are generated during this process. Both the steroid products as well as major lipoprotein cholesterol donor, high-density lipoprotein 3 (hHDL3) have the potential to negatively regulate steroidogenesis via increased oxidative stress/reactive oxygen species (ROS) generation. METHODS In the current study, we examined the effects of treatment of a mouse model of steroidogenesis, Y1-BS1 adrenocortical tumor cells with pregnenolone, 22(R)-Hydroxycholesterol [22(R)-diol] or hHDL3 on ROS production, phosphorylation status of p38 MAPK and cAMP response element-binding protein (CREB), CREB transcriptional activity and mRNA expression of StAR, CPY11A1/P450scc and antioxidant enzymes, superoxide dismutases [Cu,ZnSOD (SOD1), MnSOD (SOD2)], catalase (CAT) and glutathione peroxidase 1 (GPX1). We also detected the steroid product in p38 MAPK inhibitor treated Y1 cells by HPLC-MS / MS. RESULTS Treatment of Y1 cells with H2O2 greatly enhanced the phosphorylation of both p38 MAPK and CREB protein. Likewise, treatment of cells with pregnenolone, 22(R) diol or hHDL3 increased ROS production measured with the oxidation-sensitive fluorescent probe 2',7'-Dichlorofluorescin diacetate (DCFH-DA). Under identical experimental conditions, treatment of cells with these agents also increased the phosphorylation of p38 MAPK and CREB. This increased CREB phosphorylation however, was associated with its decreased transcriptional activity. The stimulatory effects of pregnenolone, 22(R)-diol and hHDL3 on CREB phosphorylation was abolished by a specific p38 MAPK inhibitor, SB203580. Pregnenolone, and 22(R) diol but not hHDL3 upregulated the mRNA expression of SOD1, SOD2 and GPX1, while down-regulated the mRNA levels of StAR and CYP11A1. The p38 inhibitor SB203580 could increase the steroid production in HDL3, 22(R)-diol or pregnenolone treated cells. CONCLUSION Our data demonstrate induction of a ROS/p38 MAPK -mediated feedback inhibitory pathway by oxy-cholesterol and steroid intermediates and products attenuates steroidogenesis via inhibition of CREB transcriptional activity.
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Affiliation(s)
- Jiaxin Li
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
| | - Qian Zhou
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
| | - Zhuang Ma
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
| | - Meina Wang
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
| | - Wen-Jun Shen
- 0000 0004 0419 2556grid.280747.eGeriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA 94304 USA
- 0000000419368956grid.168010.eStanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Salman Azhar
- 0000 0004 0419 2556grid.280747.eGeriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA 94304 USA
- 0000000419368956grid.168010.eStanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Zhigang Guo
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
| | - Zhigang Hu
- 0000 0001 0089 5711grid.260474.3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing, 210023 China
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Warnhoff K, Roh HC, Kocsisova Z, Tan CH, Morrison A, Croswell D, Schneider DL, Kornfeld K. The Nuclear Receptor HIZR-1 Uses Zinc as a Ligand to Mediate Homeostasis in Response to High Zinc. PLoS Biol 2017; 15:e2000094. [PMID: 28095401 PMCID: PMC5240932 DOI: 10.1371/journal.pbio.2000094] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 12/14/2016] [Indexed: 11/18/2022] Open
Abstract
Nuclear receptors were originally defined as endocrine sensors in humans, leading to the identification of the nuclear receptor superfamily. Despite intensive efforts, most nuclear receptors have no known ligand, suggesting new ligand classes remain to be discovered. Furthermore, nuclear receptors are encoded in the genomes of primitive organisms that lack endocrine signaling, suggesting the primordial function may have been environmental sensing. Here we describe a novel Caenorhabditis elegans nuclear receptor, HIZR-1, that is a high zinc sensor in an animal and the master regulator of high zinc homeostasis. The essential micronutrient zinc acts as a HIZR-1 ligand, and activated HIZR-1 increases transcription of genes that promote zinc efflux and storage. The results identify zinc as the first inorganic molecule to function as a physiological ligand for a nuclear receptor and direct environmental sensing as a novel function of nuclear receptors. Zinc is an essential nutrient for all life forms, and maintaining zinc homeostasis is critical for survival. However, little is known about how animals sense changes in zinc availability and make adjustments to maintain homeostasis. In particular, logic dictates there must be a mechanism for zinc sensing, but it has not been defined in animals. We discovered that the nuclear receptor transcription factor HIZR-1 is the master regulator of high zinc homeostasis in the roundworm Caenorhabditis elegans. In response to high dietary zinc, HIZR-1 activates transcription of multiple genes that encode a network of proteins that store and detoxify excess zinc. Furthermore, our results suggest HIZR-1 itself is the high zinc sensor, since it directly binds zinc ions in the ligand-binding domain that regulates transcriptional activation. These findings advance the understanding of zinc homeostasis and nuclear receptor biology. Nuclear receptors were initially characterized as receptors for hormones such as estrogen, indicating complex animals use these transcription factors to monitor their internal environment. However, nuclear receptors are present in simple organisms that lack endocrine signaling, suggesting these transcription factors might have a primordial function in sensing the external environment. Our results identify a new class of nuclear receptor ligands, the inorganic ion zinc, and a new function for nuclear receptors in directly sensing levels of a nutrient. We speculate that nutrient homeostasis mediated by direct binding of nutrients to the ligand-binding domain is a primordial function of nuclear receptors, whereas endocrine signaling in complex animals mediated by direct binding of hormones to the ligand-binding domain is a derived function of nuclear receptors that appeared later in evolution.
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Affiliation(s)
- Kurt Warnhoff
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Hyun C. Roh
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Zuzana Kocsisova
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Chieh-Hsiang Tan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Andrew Morrison
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Damari Croswell
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Daniel L. Schneider
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Fechter K, Dorronsoro A, Jakobsson E, Ferrin I, Lang V, Sepulveda P, Pennington DJ, Trigueros C. IFNγ Regulates Activated Vδ2+ T Cells through a Feedback Mechanism Mediated by Mesenchymal Stem Cells. PLoS One 2017; 12:e0169362. [PMID: 28076364 PMCID: PMC5226805 DOI: 10.1371/journal.pone.0169362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/15/2016] [Indexed: 01/08/2023] Open
Abstract
γδ T cells play a role in a wide range of diseases such as autoimmunity and cancer. The majority of circulating human γδ T lymphocytes express a Vγ9Vδ2+ (Vδ2+) T cell receptor (TCR) and following activation release pro-inflammatory cytokines. In this study, we show that IFNγ, produced by Vδ2+ cells, activates mesenchymal stem cell (MSC)-mediated immunosupression, which in turn exerts a negative feedback mechanism on γδ T cell function ranging from cytokine production to proliferation. Importantly, this modulatory effect is limited to a short period of time (<24 hours) post-T cell activation, after which MSCs can no longer exert their immunoregulatory capacity. Using genetically modified MSCs with the IFNγ receptor 1 constitutively silenced, we demonstrate that IFNγ is essential to this process. Activated γδ T cells induce expression of several factors by MSCs that participate in the depletion of amino acids. In particular, we show that indolamine 2,3-dioxygenase (IDO), an enzyme involved in L-tryptophan degradation, is responsible for MSC-mediated immunosuppression of Vδ2+ T cells. Thus, our data demonstrate that γδ T cell responses can be immuno-modulated by different signals derived from MSC.
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Affiliation(s)
- Karoline Fechter
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
| | - Akaitz Dorronsoro
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
| | - Emma Jakobsson
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
| | - Izaskun Ferrin
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
| | - Valérie Lang
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
| | - Pilar Sepulveda
- Fundación para la Investigación Hospital Universitario La Fe, Valencia, Spain
| | - Daniel J. Pennington
- Blizard Institute, Barts and The London School of Medicine, Queen Mary University of London, London, United Kingdom
| | - César Trigueros
- Fundación Inbiomed, Foundation for Stem Cell Research, Mesenchymal Stem Cell Laboratory, Paseo Mikeletegi, San Sebastián, Spain
- * E-mail:
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Czieselsky K, Prescott M, Porteous R, Campos P, Clarkson J, Steyn FJ, Campbell RE, Herbison AE. Pulse and Surge Profiles of Luteinizing Hormone Secretion in the Mouse. Endocrinology 2016; 157:4794-4802. [PMID: 27715255 DOI: 10.1210/en.2016-1351] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Using a new tail-tip bleeding procedure and a sensitive ELISA, we describe here the patterns of LH secretion throughout the mouse estrous cycle; in ovariectomized mice; in ovariectomized, estradiol-treated mice that model estrogen-negative and -positive feedback; and in transgenic GNR23 mice that exhibit allele-dependent reductions in GnRH neuron number. Pulsatile LH secretion was evident at all stages of the estrous cycle, with LH pulse frequency being approximately one pulse per hour in metestrous, diestrous, and proestrous mice but much less frequent at estrus (less than one pulse per 4 h). Ovariectomy resulted in substantial increases in basal and pulsatile LH secretion with pulses occurring approximately every 21 minutes. Chronic treatment with negative-feedback, estradiol-filled capsules returned LH pulse frequency to intact follicular phase levels, although pulse amplitude remained elevated. On the afternoon of proestrus, the LH surge was found to begin in a highly variable manner over a 4-hour range, lasting for more than 3 hours. In contrast, ovariectomized, estradiol-treated, positive-feedback mice exhibited a relatively uniform surge onset at approximately 0.5 hour prior to lights out. Gonadectomized wild-type and heterozygous GNR23 (∼200 GnRH neurons) male mice exhibited an LH pulse every 60 minutes. Homozygous GNR23 mice (∼80 GnRH neurons) had very low basal LH concentrations but continued to exhibit small amplitude LH pulses every 90 minutes. These studies provide the first characterization in mice of pulse and surge modes of LH secretion across the estrous cycle and demonstrate that very few GnRH neurons are required for pulsatile LH secretion.
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Affiliation(s)
- Katja Czieselsky
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Mel Prescott
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Robert Porteous
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Pauline Campos
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Jenny Clarkson
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Frederik J Steyn
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Rebecca E Campbell
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
| | - Allan E Herbison
- Centre for Neuroendocrinology and Department of Physiology (K.C., M.P., R.P., P.C., J.C., R.E.C., A.E.H.), Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand; and School of Biomedical Sciences and University of Queensland Centre for Clinical Research (F.J.S.), University of Queensland, Queensland 4072, Australia
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Baranov O, Kahle M, Deacon CF, Holst JJ, Nauck MA. Feedback suppression of meal-induced glucagon-like peptide-1 (GLP-1) secretion mediated through elevations in intact GLP-1 caused by dipeptidyl peptidase-4 inhibition: a randomized, prospective comparison of sitagliptin and vildagliptin treatment. Diabetes Obes Metab 2016; 18:1100-1109. [PMID: 27300579 DOI: 10.1111/dom.12706] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022]
Abstract
AIM To compare directly the clinical effects of vildagliptin and sitagliptin in patients with type 2 diabetes, with a special emphasis on incretin hormones and L-cell feedback inhibition induced by dipeptidyl peptidase (DPP-4) inhibition. METHODS A total of 24 patients (12 on a diet/exercise regimen, 12 on metformin) were treated, in randomized order, for 7-9 days, with either vildagliptin (50 mg twice daily = 100 mg/d), sitagliptin (100 mg once daily in those on diet, 50 mg twice daily in those on metformin treatment = 100 mg/d) or placebo (twice daily). A mixed-meal test was performed. RESULTS Intact glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide concentrations were doubled by both DPP-4 inhibitors. Meal-related total GLP-1 responses were reduced by vildagliptin and sitagliptin treatment alike in the majority of patients (vildagliptin: p = 0.0005; sitagliptin: p = 0.019), but with substantial inter-individual variation. L-cell feedback appeared to be more pronounced in those whose intact GLP-1 relative to total GLP-1 increased more, and who had greater reductions in fasting plasma glucose after DPP-4 inhibition. K-cell feedback inhibition overall was not significant. There were no differences in any of the clinical variables (glycaemia, insulin and glucagon secretory responses) between vildagliptin and sitagliptin treatment. CONCLUSIONS Vildagliptin and sitagliptin affected incretin hormones, glucose concentrations, insulin and glucagon secretion in a similar manner. Inter-individual variations in L-cell feedback inhibition may indicate heterogeneity in the clinical response to DPP-4 inhibition.
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Affiliation(s)
- Oleg Baranov
- Diabeteszentrum Bad Lauterberg, Bad Lauterberg im Harz, Germany
| | - Melanie Kahle
- Diabeteszentrum Bad Lauterberg, Bad Lauterberg im Harz, Germany
- Division of Diabetology, Medical Department I, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Carolyn F Deacon
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Michael A Nauck
- Diabeteszentrum Bad Lauterberg, Bad Lauterberg im Harz, Germany.
- Division of Diabetology, Medical Department I, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany.
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