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Zhao YH, Wu ZX, Zhao X, Jiang J, Jiang R. Low androgen level impairs erectile function of rat by regulating the Ng/CaN/AKT/eNOS pathway in penile corpus cavernosum. Andrology 2022; 10:1189-1196. [PMID: 35678097 DOI: 10.1111/andr.13202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/06/2022] [Accepted: 06/02/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND The mechanism by which low androgen status inhibit erectile function has not yet been clearly elucidated. Neurogranin (Ng) is a Ca2+ -sensitive calmodulin binding protein that is expressed in endothelial cells and regulates eNOS function. OBJECTIVES To investigate whether low androgen status inhibit erectile function by regulating the Ng/CaN/AKT/eNOS pathway in the penile cavernous tissue of rats. MATERIALS AND METHODS Thirty-six 8-week-old male Sprague-Dawley rats were randomly divided into six groups as follows (n = 6): 4-week control group (4w-control), 4-week castration group (4w-cast), 4-week castration+testosterone replacement group (4w-cast+T), 8-week control group (8w-control), 8-week castration group (8w-cast), and 8-week castration+testosterone replacement group (8w-cast+T). Four weeks and eight weeks after surgery, the ratio of the maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP) was examined. The level of NO and the expression of Ng, calcineurin (CaN), AKT, p-AKT(S473), eNOS, and p-eNOS(Ser1177) in the penile cavernous tissue of each group were determined. RESULTS Ng and CaN were mainly expressed in the membrane and cytoplasm of endothelial cells and smooth muscle cells in the penile cavernous tissue of rats. The ICPmax/MAP and the concentration of NO in the cast group were significantly lower than those in the control group and cast+T replacement group (p < 0.01). The expression of Ng and the ratios of p-AKT/AKT and p-eNOS/eNOS in the penile cavernous tissue of rats in the cast group were significantly lower than those in the control group and cast+T replacement group (p < 0.01). The expression of CaN in the penile cavernous tissue of rats in the cast group was significantly increased compared with that in the control group and the cast+T replacement group (p < 0.01). CONCLUSION Inhibiting the expression of Ng and subsequently upregulating the expression of CaN in the rat penile cavernous tissue was one of the upstream mechanisms of low androgen status inhibiting erectile function by inhibiting the AKT/eNOS signaling pathway.
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Affiliation(s)
- Yu-Hao Zhao
- Department of Urology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Ze-Xiu Wu
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xin Zhao
- Department of Urology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jun Jiang
- Department of Thyroid Surgery, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Rui Jiang
- Department of Urology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Nephropathy Clinical Medical Research Center of Sichuan Province, Sichuan, China
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2
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Hasan N, Chawla R, Shaikh N, Kandasamy S, Azad SV, Sundar MD. A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology. Ther Adv Ophthalmol 2022; 14:25158414221097418. [PMID: 35602659 PMCID: PMC9121505 DOI: 10.1177/25158414221097418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 04/11/2022] [Indexed: 12/18/2022] Open
Abstract
Systemic immunosuppressants and biologicals have been a valuable tool in the
treatment of inflammatory diseases and malignancies. The safety profile of these
drugs has been debatable, especially in localized systems, such as the eye. This
has led to the search for fairly local approaches, such as intravitreal,
subconjunctival, and topical route of administration. Immunosuppressants have
been used as a second-line drug in patients intolerable to corticosteroids or
those who develop multiple recurrences on weaning corticosteroids. Similarly,
biologicals have also been used as the next line of therapy, when adequate
control of inflammation could not be attained or immunosuppressants were
contraindicated to patients. Intravitreal immunosuppressants, such as
methotrexate and sirolimus, have been extensively studied in noninfectious
posterior uveitis, whereas limited studies have established the efficacy of
intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs
have shown good safety profile and tolerability in animal studies alone and have
not been studied further in human subjects. However, most of the studies in
literature are single-case reports or case series which limits the level of
evidence. In this comprehensive review, we discuss the mechanism of action,
pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of
different intravitreal immunosuppressants and biologicals that have been studied
in literature.
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Affiliation(s)
- Nasiq Hasan
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - Rohan Chawla
- Associate Professor, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, New Delhi 110029, India
| | - Nawazish Shaikh
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | | | | | - M. Dheepak Sundar
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
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3
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Pardo AC, Zegarra LD, González Arbeláez LF, Ibáñez AM, Díaz RG, Aiello EA, Mosca SM. Cardioprotective effects of N-methylacetazolamide mediated by inhibition of L-type Ca2+ channel current. Biochim Biophys Acta Gen Subj 2022; 1866:130098. [DOI: 10.1016/j.bbagen.2022.130098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/20/2022] [Accepted: 01/22/2022] [Indexed: 11/25/2022]
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4
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Skrzycki M, Kaźmierczak B. The hidden role of the Sigma1 receptor in muscle cells. J Recept Signal Transduct Res 2020; 40:201-208. [PMID: 32054378 DOI: 10.1080/10799893.2020.1727924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 10/25/2022]
Abstract
This review describes the very specific role of Sigma1 receptor in different types of muscle cells. Sigma1 receptor is a transmembrane protein residing in such structures like MAM. It has chaperoning activity supporting function of many proteins, particularly ion channels, including Ca2+ channels. This latter function is of particular meaning for muscle cells, due to their calcium-based/regulated metabolism. Here we discuss new reports pointing to participation of Sigma1 receptor in muscle specific processes like contraction, EC-coupling, calcium currents and in diseases like left ventricular hypertrophy, transverse aortic stenosis and hypertension-induced heart dysfunction.
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Affiliation(s)
- Michał Skrzycki
- Department of Biochemistry, Medical University of Warsaw, Warsaw, Poland
| | - Beata Kaźmierczak
- Department of Biochemistry, Medical University of Warsaw, Warsaw, Poland
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5
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Cheriyan VT, Alfaidi M, Jorgensen AN, Alam MA, Abdullah CS, Kolluru GK, Bhuiyan MS, Kevil CG, Orr AW, Nam HW. Neurogranin regulates eNOS function and endothelial activation. Redox Biol 2020; 34:101487. [PMID: 32173345 PMCID: PMC7327963 DOI: 10.1016/j.redox.2020.101487] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023] Open
Abstract
Endothelial nitric oxide (NO) is a critical mediator of vascular function and vascular remodeling. NO is produced by endothelial nitric oxide synthase (eNOS), which is activated by calcium (Ca2+)-dependent and Ca2+-independent pathways. Here, we report that neurogranin (Ng), which regulates Ca2+-calmodulin (CaM) signaling in the brain, is uniquely expressed in endothelial cells (EC) of human and mouse vasculature, and is also required for eNOS regulation. To test the role of Ng in eNOS activation, Ng knockdown in human aortic endothelial cells (HAEC) was performed using Ng SiRNA along with Ng knockout (Ng −/−) in mice. Depletion of Ng expression decreased eNOS activity in HAEC and NO production in mice. We show that Ng expression was decreased by short-term laminar flow and long-them oscillating flow shear stress, and that Ng siRNA with shear stress decreased eNOS expression as well as eNOS phosphorylation at S1177. We further reveled that lack of Ng expression decreases both AKT-dependent eNOS phosphorylation, NF-κB-mediated eNOS expression, and promotes endothelial activation. Our findings also indicate that Ng modulates Ca2+-dependent calcineurin (CaN) activity, which suppresses Ca2+-independent AKT-dependent eNOS signaling. Moreover, deletion of Ng in mice also reduced eNOS activity and caused endothelial dysfunction in flow-mediated dilation experiments. Our results demonstrate that Ng plays a crucial role in Ca2+-CaM-dependent eNOS regulation and contributes to vascular remodeling, which is important for the pathophysiology of cardiovascular disease. Neurogranin is expressed in endothelial cell and is required for eNOS regulation. Short-term laminar flow and long-them oscillating flow decrease Neurogranin expression in endothelial cells. Neurogranin knockdown decreases both AKT-dependent eNOS phosphorylation and eNOS expression. Deletion of Ng in mice reduces eNOS activity and caused endothelial dysfunction in flow-mediated dilation.
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Affiliation(s)
- Vino T Cheriyan
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Mabruka Alfaidi
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Ashton N Jorgensen
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Md Ashiqul Alam
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Chowdhury S Abdullah
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Gopi K Kolluru
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Md Shenuarin Bhuiyan
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Christopher G Kevil
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - A Wayne Orr
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Hyung W Nam
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA.
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Pi H, Li M, Zou L, Yang M, Deng P, Fan T, Liu M, Tian L, Tu M, Xie J, Chen M, Li H, Xi Y, Zhang L, He M, Lu Y, Chen C, Zhang T, Wang Z, Yu Z, Gao F, Zhou Z. AKT inhibition-mediated dephosphorylation of TFE3 promotes overactive autophagy independent of MTORC1 in cadmium-exposed bone mesenchymal stem cells. Autophagy 2018; 15:565-582. [PMID: 30324847 DOI: 10.1080/15548627.2018.1531198] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cadmium (Cd) is a toxic metal that is widely found in numerous environmental matrices and induces serious adverse effects in various organs and tissues. Bone tissue seems to be a crucial target of Cd contamination. Macroautophagy/autophagy has been proposed to play a pivotal role in Cd-mediated bone toxicity. However, the mechanisms that underlie Cd-induced autophagy are not yet completely understood. We demonstrated that Cd treatment increased autophagic flux and inhibition of the autophagic process using Atg7 gene silencing blocked the Cd-induced mesenchymal stem cell death. Mechanistically, Cd activated nuclear translocation of TFE3 but not that of TFEB or MITF, which contributed to the expression of autophagy-related genes and lysosomal biogenesis. Specifically, Cd decreased expression of phospho-AKT (Ser473). The reduction in AKT activity led to dephosphorylation of cytosolic TFE3 at Ser565 and promoted TFE3 nuclear translocation independently of MTORC1. Notably, Cd treatment increased the activity of PPP3/calcineurin, and pharmacological inhibition of PPP3/calcineurin with FK506 suppressed AKT dephosphorylation and TFE3 activity. These results suggest that PPP3/calcineurin negatively regulates AKT phosphorylation and is involved in Cd-induced TFE3-dependent autophagy. Modulation of the PPP3/calcineurin-AKT-TFE3 autophagic-lysosomal machinery may offer novel therapeutic approaches for the treatment of Cd-induced bone damage. Abbreviations: ACTB: actin: beta; AKT: thymoma viral proto-oncogene; AMPK: AMP-activated protein kinase; ATG: autophagy related; Baf A1: bafilomycin A1; Cd: cadmium; FOXO3: forkhead box O3; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MITF: melanogenesis associated transcription factor; MSC: mesenchymal stem sell; MTORC1: mechanistic target of rapamycin kinase complex 1; RPS6KB1: ribosomal protein S6 kinase: polypeptide 1; SGK1: serum/glucocorticoid regulated kinase 1; SQSTM1/p62: sequestosome 1;TFE3: transcription factor E3; TFEB: transcription factor EB; TFEC: transcription factor EC.
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Affiliation(s)
- Huifeng Pi
- b Department of Occupational Health , Third Military Medical University , Chongqing , China.,c Department of Aerospace Medicine , Fourth Military Medical University , Xi'an , China
| | - Min Li
- b Department of Occupational Health , Third Military Medical University , Chongqing , China.,d Wuhan General Hospital of Guangzhou Military Region , Wuhan , China
| | - Lingyun Zou
- e Bao'an Maternal and Child Health Hospital , Jinan University , Shenzhen , China
| | - Min Yang
- b Department of Occupational Health , Third Military Medical University , Chongqing , China.,f Department of Gastroenterology, XinQiao Hospital , Third Military Medical University , Chongqing , China
| | - Ping Deng
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Tengfei Fan
- g Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital , Central South University , Changsha , China
| | - Menyu Liu
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Li Tian
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Manyu Tu
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Jia Xie
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Mengyan Chen
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Huijuan Li
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Yu Xi
- a Department of Environmental Medicine, and Department of Critical Care Medicine of the First Affiliated Hospital , Zhejiang University School of Medicine , Hangzhou , China
| | - Lei Zhang
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Mindi He
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Yonghui Lu
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Chunhai Chen
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Tao Zhang
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Zheng Wang
- c Department of Aerospace Medicine , Fourth Military Medical University , Xi'an , China
| | - Zhengping Yu
- b Department of Occupational Health , Third Military Medical University , Chongqing , China
| | - Feng Gao
- c Department of Aerospace Medicine , Fourth Military Medical University , Xi'an , China
| | - Zhou Zhou
- a Department of Environmental Medicine, and Department of Critical Care Medicine of the First Affiliated Hospital , Zhejiang University School of Medicine , Hangzhou , China.,b Department of Occupational Health , Third Military Medical University , Chongqing , China
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7
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Kumarasamy S, Solanki S, Atolagbe OT, Joe B, Birnbaumer L, Vazquez G. Deep Transcriptomic Profiling of M1 Macrophages Lacking Trpc3. Sci Rep 2017; 7:39867. [PMID: 28051144 PMCID: PMC5209678 DOI: 10.1038/srep39867] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/28/2016] [Indexed: 01/18/2023] Open
Abstract
In previous studies using mice with macrophage-specific loss of TRPC3 we found a significant, selective effect of TRPC3 on the biology of M1, or inflammatory macrophages. Whereas activation of some components of the unfolded protein response and the pro-apoptotic mediators CamkII and Stat1 was impaired in Trpc3-deficient M1 cells, gathering insight about other molecular signatures within macrophages that might be affected by Trpc3 expression requires an alternative approach. In the present study we conducted RNA-seq analysis to interrogate the transcriptome of M1 macrophages derived from mice with macrophage-specific loss of TRPC3 and their littermate controls. We identified 160 significantly differentially expressed genes between the two groups, of which 62 were upregulated and 98 downregulated in control vs. Trpc3-deficient M1 macrophages. Gene ontology analysis revealed enrichment in processes associated to cellular movement and lipid signaling, whereas the enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways included networks for calcium signaling and cell adhesion molecules, among others. This is the first deep transcriptomic analysis of macrophages in the context of Trpc3 deficiency and the data presented constitutes a unique resource to further explore functions of TRPC3 in macrophage biology.
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Affiliation(s)
- Sivarajan Kumarasamy
- Department of Physiology and Pharmacology, and Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, University of Toledo Health Science Campus, 3000 Transverse Dr., Toledo, Ohio 43614 USA
| | - Sumeet Solanki
- Department of Physiology and Pharmacology, and Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, University of Toledo Health Science Campus, 3000 Transverse Dr., Toledo, Ohio 43614 USA
| | - Oluwatomisin T Atolagbe
- Department of Physiology and Pharmacology, and Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, University of Toledo Health Science Campus, 3000 Transverse Dr., Toledo, Ohio 43614 USA
| | - Bina Joe
- Department of Physiology and Pharmacology, and Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, University of Toledo Health Science Campus, 3000 Transverse Dr., Toledo, Ohio 43614 USA
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, 111 TW Alexander Dr., Research Triangle Park, North Carolina 27709 USA.,Institute of Biomedical Research (BIOMED UCA-CONICET), Faculty of Medical Sciences, Av. Alicia Moreau de Justo 1600, C1107AFF Buenos Aires, Argentina
| | - Guillermo Vazquez
- Department of Physiology and Pharmacology, and Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, University of Toledo Health Science Campus, 3000 Transverse Dr., Toledo, Ohio 43614 USA
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Vinciotti V, Wit EC, Jansen R, de Geus EJCN, Penninx BWJH, Boomsma DI, ’t Hoen PAC. Consistency of biological networks inferred from microarray and sequencing data. BMC Bioinformatics 2016; 17:254. [PMID: 27342572 PMCID: PMC4919861 DOI: 10.1186/s12859-016-1136-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/10/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Sparse Gaussian graphical models are popular for inferring biological networks, such as gene regulatory networks. In this paper, we investigate the consistency of these models across different data platforms, such as microarray and next generation sequencing, on the basis of a rich dataset containing samples that are profiled under both techniques as well as a large set of independent samples. RESULTS Our analysis shows that individual node variances can have a remarkable effect on the connectivity of the resulting network. Their inconsistency across platforms and the fact that the variability level of a node may not be linked to its regulatory role mean that, failing to scale the data prior to the network analysis, leads to networks that are not reproducible across different platforms and that may be misleading. Moreover, we show how the reproducibility of networks across different platforms is significantly higher if networks are summarised in terms of enrichment amongst functional groups of interest, such as pathways, rather than at the level of individual edges. CONCLUSIONS Careful pre-processing of transcriptional data and summaries of networks beyond individual edges can improve the consistency of network inference across platforms. However, caution is needed at this stage in the (over)interpretation of gene regulatory networks inferred from biological data.
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Affiliation(s)
| | - Ernst C. Wit
- />Johann Bernoulli Institute of Mathematics and Computer Science, University of Groningen, Groningen, The Netherlands
| | - Rick Jansen
- />VU University Medical Center, Amsterdam, The Netherlands
| | | | | | | | - Peter A. C. ’t Hoen
- />Leiden University Medical Center, Leiden University, Leiden, The Netherlands
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9
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Role of transient receptor potential ankyrin 1 channels in Alzheimer's disease. J Neuroinflammation 2016; 13:92. [PMID: 27121378 PMCID: PMC4847235 DOI: 10.1186/s12974-016-0557-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/19/2016] [Indexed: 12/14/2022] Open
Abstract
Background Transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in pain and inflammation. However, little is known about the significance of the TRPA1 channel in the pathophysiology of Alzheimer’s disease (AD). Methods Wild-type (WT), TRPA1−/−, amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic (APP/PS1 Tg) mice, the mouse model of AD, and APP/PS1 Tg/TRPA1−/− mice were used to examine the role of TRPA1 in pathogenesis of AD. Western blot was used for protein expression; immunohistochemistry was used for histological examination. The mouse behaviors were evaluated by locomotion, nesting building, Y-maze and Morris water maze tests; levels of interleukin (IL)-1β, IL-4, IL-6 and IL-10 and the activities of protein phosphatase 2B (PP2B), NF-κB and nuclear factor of activated T cells (NFAT) were measured by conventional assay kits; Fluo-8 NW calcium (Ca2+) assay kit was used for the measurement of intracellular Ca2+ level in primary astrocytes and HEK293 cells. Results The protein expression of TRPA1 channels was higher in brains, mainly astrocytes of the hippocampus, from APP/PS1 Tg mice than WT mice. Ablation of TRPA1-channel function in APP/PS1 Tg mice alleviated behavioral dysfunction, Aβ plaque deposition and pro-inflammatory cytokine production but increased astrogliosis in brain lesions. TRPA1 channels were activated and Ca2+ influx was elicited in both astrocytes and TRPA1-transfected HEK293 cells treated with fibrilized Aβ1–42; these were abrogated by pharmacological inhibition of TRPA1 channel activity, disruption of TRPA1 channel function or removal of extracellular Ca2+. Inhibition of TRPA1 channel activity exacerbated Aβ1–42–induced astrogliosis but inhibited Aβ1–42–increased PP2B activation, the production of pro-inflammatory cytokines and activities of transcriptional factors NF-κB and NFAT in astrocytes and in APP/PS1 Tg mice. Pharmacological inhibition of PP2B activity diminished the fibrilized Aβ1–42–induced production of pro-inflammatory cytokines, activation of NF-κB and NFAT and astrogliosis in astrocytes. Conclusions TRPA1 − Ca2+ − PP2B signaling may play a crucial role in regulating astrocyte-derived inflammation and pathogenesis of AD. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0557-z) contains supplementary material, which is available to authorized users.
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10
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Nakayama M, Inoue T, Naito M, Nakayama K, Ohara N. Attenuation of the phosphatidylinositol 3-kinase/Akt signaling pathway by Porphyromonas gingivalis gingipains RgpA, RgpB, and Kgp. J Biol Chem 2015; 290:5190-5202. [PMID: 25564612 DOI: 10.1074/jbc.m114.591610] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Porphyromonas gingivalis is a major pathogen of periodontal diseases, including periodontitis. We have investigated the effect of P. gingivalis infection on the PI3K/Akt (protein kinase B) signaling pathway in gingival epithelial cells. Here, we found that live P. gingivalis, but not heat-killed P. gingivalis, reduced Akt phosphorylation at both Thr-308 and Ser-473, which implies a decrease in Akt activity. Actually, PI3K, which is upstream of Akt, was also inactivated by P. gingivalis. Furthermore, glycogen synthase kinase 3α/β, mammalian target of rapamycin, and Bad, which are downstream proteins in the PI3K/Akt cascade, were also dephosphorylated, a phenomenon consistent with Akt inactivation by P. gingivalis. However, these events did not require direct interaction between bacteria and host cells and were independent of P. gingivalis invasion into the cells. The use of gingipain-specific inhibitors and a gingipain-deficient P. gingivalis mutant KDP136 revealed that the gingipains and their protease activities were essential for the inactivation of PI3K and Akt. The associations between the PI3K regulatory subunit p85α and membrane proteins were disrupted by wild-type P. gingivalis. Moreover, PDK1 translocation to the plasma membrane was reduced by wild-type P. gingivalis, but not KDP136, indicating little production of phosphatidylinositol 3,4,5-triphosphate by PI3K. Therefore, it is likely that PI3K failed to transmit homeostatic extracellular stimuli to intracellular signaling pathways by gingipains. Taken together, our findings indicate that P. gingivalis attenuates the PI3K/Akt signaling pathway via the proteolytic effects of gingipains, resulting in the dysregulation of PI3K/Akt-dependent cellular functions and the destruction of epithelial barriers.
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Affiliation(s)
- Masaaki Nakayama
- From the Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and; the Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama 700-8558 and
| | - Tetsuyoshi Inoue
- From the Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and; the Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama 700-8558 and
| | - Mariko Naito
- the Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Koji Nakayama
- the Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Naoya Ohara
- From the Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and; the Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama 700-8558 and.
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11
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Lee SH, Choi J, Kim H, Lee DH, Roh GS, Kim HJ, Kang SS, Choi WS, Cho GJ. FK506 reduces calpain-regulated calcineurin activity in both the cytoplasm and the nucleus. Anat Cell Biol 2014; 47:91-100. [PMID: 24987545 PMCID: PMC4076426 DOI: 10.5115/acb.2014.47.2.91] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 05/30/2014] [Accepted: 06/03/2014] [Indexed: 12/25/2022] Open
Abstract
Excessive immune responses induced by ischemia-reperfusion injury (IRI) are known to lead to necrotic and apoptotic cell death, and calcineurin plays a major role in this process. Calcineurin dephosphorylates the nuclear factor of activated T-cells (NFAT), permitting its translocation into the nucleus. As a result, calcineurin promotes the release of pro-inflammatory cytokines, such as tumor necrosis factor-α. The overproduction of pro-inflammatory cytokines causes renal cell death. Calcineurin activity is regulated by calpain, a cysteine protease present in the nucleus. Calpain-mediated proteolysis increases the phosphatase activity of calcineurin, resulting in NFAT dephosphorylation. This process has been studied in cardiomyocytes but its role in renal IRI is unknown. Thus, we examined whether calpain regulates calcineurin in renal tubule nuclei. We established an in vivo renal IRI model in mice and identified the protective role of a calcineurin inhibitor, FK506, in this process. Calcineurin is expressed in the nucleus, where it is present in its calpain-cleaved form. FK506 reduced nuclear expression of calcineurin and prevented calcineurin-mediated NFAT activation. Our study shows clearly that FK506 reduces calpain-mediated calcineurin activity. Consequently, calcineurin could not maintain NFAT activation. FK506 reduced renal cell death by suppressing the transcription of pro-inflammatory cytokine genes. This study provides evidence that FK506 protects against inflammation in a renal IRI mouse model. We also provided a mechanism of calcineurin action in the nucleus. Therefore, FK506 could improve renal function by decreasing calcineurin activity in both the cytoplasm and the nucleus of renal tubule cells.
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Affiliation(s)
- Sun Hee Lee
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Jungil Choi
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Hwajin Kim
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Dong Hoon Lee
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Gu Seob Roh
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Hyun Joon Kim
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Sang Soo Kang
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Wan Sung Choi
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University School of Medicine, Jinju, Korea
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12
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Ziegler S, Gartner K, Scheuermann U, Zoeller T, Hantzschmann J, Over B, Foermer S, Heeg K, Bekeredjian-Ding I. Ca(2+) -related signaling events influence TLR9-induced IL-10 secretion in human B cells. Eur J Immunol 2014; 44:1285-98. [PMID: 24470136 DOI: 10.1002/eji.201343994] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/30/2013] [Accepted: 01/22/2014] [Indexed: 11/11/2022]
Abstract
Suppressory B-cell function controls immune responses and is mainly dependent on IL-10 secretion. Pharmacological manipulation of B-cell-specific IL-10 synthesis could, thus, be therapeutically useful in B-cell chronic lymphocytic leukemia, transplantation, autoimmunity and sepsis. TLR are thought to play a protagonistic role in the formation of IL-10-secreting B cells. The aim of the study was to identify the molecular events selectively driving IL-10 production in TLR9-stimulated human B cells. Our data highlight the selectivity of calcineurin inhibitors in blocking TLR9-induced B-cell-derived IL-10 transcription and secretion, while IL-6 transcription and release, B-cell proliferation, and differentiation remain unaffected. Nevertheless, TLR9-induced IL-10 production was found to be independent of calcineurin phosphatase activity and was even negatively regulated by NFAT. In contrast to TLR9-induced IL-6, IL-10 secretion was highly sensitive to targeting of spleen tyrosine kinase (syk) and Bruton's tyrosine kinase. Further analyses demonstrated increased phosphorylation of Ca(2+) /calmodulin kinase II (CaMKII) in TLR9-stimulated B cells and selective reduction of TLR9-induced secretion of IL-10 upon treatment with CaMKII inhibitors, with negligible impact on IL-6 levels. Altogether, our results identify calcineurin antagonists as selective inhibitors of IL-10 transcription and syk/Bruton´s tyrosine kinase-induced Ca(2+) /calmodulin- and CaMKII-dependent signaling as a pathway regulating the release of TLR9-induced B-cell-derived IL-10.
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Affiliation(s)
- Saskia Ziegler
- Department of Infectious Diseases, University Hospital Heidelberg, Heidelberg, Germany
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13
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D'Alessandro A, Cervia D, Catalani E, Gevi F, Zolla L, Casini G. Protective effects of the neuropeptides PACAP, substance P and the somatostatin analogue octreotide in retinal ischemia: a metabolomic analysis. MOLECULAR BIOSYSTEMS 2014; 10:1290-304. [PMID: 24514073 DOI: 10.1039/c3mb70362b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ischemia is a primary cause of neuronal death in retinal diseases and the somatostatin subtype receptor 2 agonist octreotide (OCT) is known to decrease ischemia-induced retinal cell death. Using a recently optimized ex vivo mouse model of retinal ischemia, we tested the anti-ischemic potential of two additional neuropeptides, pituitary adenylate cyclase activating peptide (PACAP) and substance P (SP), and monitored the major changes occurring at the metabolic level. Metabolomics analyses were performed via fast HPLC online using a microTOF-Q MS instrument, a workflow that is increasingly becoming the gold standard in the field of metabolomics. The metabolomic approach allowed detection of the most significant alterations induced in the retina by ischemia and of the significance of the protective effects exerted by OCT, PACAP or SP. All treatments were shown to reduce ischemia-induced cell death, vascular endothelial growth factor over-expression and glutamate release. The metabolomic analysis showed that OCT and, to a lesser extent, also PACAP or SP, were able to counteract the ischemia-induced oxidative stress and to promote, with various efficacies, (i) decreased accumulation of glutamate and normalization of glutathione homeostasis; (ii) reduced build-up of α-ketoglutarate, which might serve as a substrate for the enhanced biosynthesis of glutamate in response to ischemia; (iii) reduced accumulation of peroxidized lipids and inflammatory mediators; (iv) the normalization of glycolytic fluxes and thus preventing the over-accumulation of lactate or either promoting the down-regulation of the glyoxalate anti-oxidant system; (v) a reduced metabolic shift from glycolysis towards the PPP or either a blockade at the non-oxidative phase of the PPP; and (vi) tuning down of purine metabolism. In addition, OCT seemed to stimulate nitric oxide production. None of the treatments was able to restore ATP production, although ATP reservoirs were partly replenished by OCT, PACAP or SP. These data indicate that, in addition to that of somatostatin, peptidergic systems such as those of PACAP and SP deserve attention in view of peptide-based therapies to treat ischemic retinal disorders.
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Affiliation(s)
- Angelo D'Alessandro
- Dipartimento di Scienze Ecologiche e Biologiche, Università della Tuscia, L.go dell'Università snc, I-01100 Viterbo, Italy.
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Berchtold MW, Villalobo A. The many faces of calmodulin in cell proliferation, programmed cell death, autophagy, and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:398-435. [PMID: 24188867 DOI: 10.1016/j.bbamcr.2013.10.021] [Citation(s) in RCA: 230] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 10/24/2013] [Accepted: 10/26/2013] [Indexed: 12/21/2022]
Abstract
Calmodulin (CaM) is a ubiquitous Ca(2+) receptor protein mediating a large number of signaling processes in all eukaryotic cells. CaM plays a central role in regulating a myriad of cellular functions via interaction with multiple target proteins. This review focuses on the action of CaM and CaM-dependent signaling systems in the control of vertebrate cell proliferation, programmed cell death and autophagy. The significance of CaM and interconnected CaM-regulated systems for the physiology of cancer cells including tumor stem cells, and processes required for tumor progression such as growth, tumor-associated angiogenesis and metastasis are highlighted. Furthermore, the potential targeting of CaM-dependent signaling processes for therapeutic use is discussed.
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Key Words
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-ethyl]-4,5-dihydro-pyrazol-1-yl]-benzoic acid
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-vinyl]-4,5-dihydro-pyrazol-1-yl]-phenyl)-(4-methyl-piperazin-1-yl)-methanone
- (−) enantiomer of dihydropyrine 3-methyl-5-3-(4,4-diphenyl-1-piperidinyl)-propyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-piridine-3,5-dicarboxylate-hydrochloride (niguldipine)
- 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine
- 12-O-tetradecanoyl-phorbol-13-acetate
- 2-chloro-(ε-amino-Lys(75))-[6-(4-(N,N′-diethylaminophenyl)-1,3,5-triazin-4-yl]-CaM adduct
- 3′-(β-chloroethyl)-2′,4′-dioxo-3,5′-spiro-oxazolidino-4-deacetoxy-vinblastine
- 7,12-dimethylbenz[a]anthracene
- Apoptosis
- Autophagy
- B859-35
- CAPP(1)-CaM
- Ca(2+) binding protein
- Calmodulin
- Cancer biology
- Cell proliferation
- DMBA
- EBB
- FL-CaM
- FPCE
- HBC
- HBCP
- J-8
- KAR-2
- KN-62
- KN-93
- N-(4-aminobutyl)-2-naphthalenesulfonamide
- N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide
- N-(6-aminohexyl)-1-naphthalenesulfonamide
- N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide
- N-8-aminooctyl-5-iodo-naphthalenesulfonamide
- N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide
- O-(4-ethoxyl-butyl)-berbamine
- RITC-CaM
- TA-CaM
- TFP
- TPA
- W-12
- W-13
- W-5
- W-7
- fluorescein-CaM adduct
- fluphenazine-N-2-chloroethane
- norchlorpromazine-CaM adduct
- rhodamine isothiocyanate-CaM adduct
- trifluoperazine
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Affiliation(s)
- Martin W Berchtold
- Department of Biology, University of Copenhagen, Copenhagen Biocenter 4-2-09 Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Antonio Villalobo
- Instituto de Investigaciones Biomédicas, Department of Cancer Biology, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/Arturo Duperier 4, E-28029 Madrid, Spain.
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15
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Shimamura M, Zhou P, Casolla B, Qian L, Capone C, Kurinami H, Iadecola C, Anrather J. Prostaglandin E2 type 1 receptors contribute to neuronal apoptosis after transient forebrain ischemia. J Cereb Blood Flow Metab 2013; 33:1207-14. [PMID: 23632967 PMCID: PMC3734771 DOI: 10.1038/jcbfm.2013.69] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 11/09/2022]
Abstract
Cyclooxygenase-2-derived prostaglandin E2 (PGE2) contributes to excitotoxic and ischemic neuronal cell death by engaging neuronal PGE2 type 1 receptors (EP1R). Our previous studies have shown that EP1R signaling resulted in disturbances of intracellular Ca(2+) homeostasis and suppression of the pro-survival protein kinase AKT. The aim of this study was to investigate whether these pathophysiological mechanism have a role in the neuronal cell death after transient forebrain ischemia. Mice were subjected to ischemia/reperfusion by bilateral common carotid artery occlusion. Hippocampal cornu ammonis area 1 (CA1) neuronal cell death was determined 5 days after reperfusion. Animals treated with the EP1R antagonist SC51089 or EP1R-deficient mice (EP1(-/-)) showed significantly less neuronal injury as compared to vehicle-treated wild-type controls. Benefits of EP1R blockage were still evident 14 days after injury. Better neuronal survival was correlated with reduced neuronal caspase-3 activity and decreased nuclear translocation of the apoptosis-inducing factor . Neuroprotection could be reverted by intracerebroventricular administration of the phosphoinositide 3-kinase inhibitor LY294002 and was not further increased by the calcineurin inhibitor FK506. These data implicate EP1R in postischemic neuronal apoptosis possibly by facilitating AKT inhibition.
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Affiliation(s)
- Munehisa Shimamura
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
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16
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Bhuiyan MS, Tagashira H, Fukunaga K. Crucial interactions between selective serotonin uptake inhibitors and sigma-1 receptor in heart failure. J Pharmacol Sci 2013; 121:177-84. [PMID: 23428811 DOI: 10.1254/jphs.12r13cp] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Depression is associated with a substantial increase in the risk of developing heart failure and is independently associated with increased cardiovascular morbidity and mortality. Inversely, cardiovascular disease can lead to severe depression. Thus, therapy with selective serotonin reuptake inhibitors (SSRIs) is strongly recommended to reduce cardiovascular disease-induced morbidity and mortality. However, molecular mechanisms to support evidence-based SSRI treatment of cardiovascular disease have not been elucidated. We recently found very high expression of the sigma-1 receptor, an orphan receptor, in rat heart tissue and defined the cardiac sigma-1 receptor as a direct SSRI target in eliciting cardioprotection in both pressure overload (PO)induced and transverse aortic constriction (TAC)-induced myocardial hypertrophy models in rodents. Our findings suggest that SSRIs such as fluvoxamine protect against PO- and TAC-induced cardiac dysfunction by upregulating sigma-1 receptor expression and stimulating sigma-1 receptor-mediated Akt-eNOS signaling. Here, we discuss the association of depression and cardiovascular diseases, the protective mechanism of SSRIs in heart failure patients, and the pathophysiological relevance of sigma-1 receptors to progression of heart failure. These findings should promote development of clinical therapeutics targeting the sigma-1 receptor in cardiovascular diseases.
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Affiliation(s)
- Md Shenuarin Bhuiyan
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, The Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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17
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Qi Y, Chen L, Zhang L, Liu WB, Chen XY, Yang XG. Crocin prevents retinal ischaemia/reperfusion injury-induced apoptosis in retinal ganglion cells through the PI3K/AKT signalling pathway. Exp Eye Res 2013. [DOI: 10.1016/j.exer.2012.11.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Talbot K, Wang HY, Kazi H, Han LY, Bakshi KP, Stucky A, Fuino RL, Kawaguchi KR, Samoyedny AJ, Wilson RS, Arvanitakis Z, Schneider JA, Wolf BA, Bennett DA, Trojanowski JQ, Arnold SE. Demonstrated brain insulin resistance in Alzheimer's disease patients is associated with IGF-1 resistance, IRS-1 dysregulation, and cognitive decline. J Clin Invest 2012; 122:1316-38. [PMID: 22476197 DOI: 10.1172/jci59903] [Citation(s) in RCA: 1295] [Impact Index Per Article: 107.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
While a potential causal factor in Alzheimer's disease (AD), brain insulin resistance has not been demonstrated directly in that disorder. We provide such a demonstration here by showing that the hippocampal formation (HF) and, to a lesser degree, the cerebellar cortex in AD cases without diabetes exhibit markedly reduced responses to insulin signaling in the IR→IRS-1→PI3K signaling pathway with greatly reduced responses to IGF-1 in the IGF-1R→IRS-2→PI3K signaling pathway. Reduced insulin responses were maximal at the level of IRS-1 and were consistently associated with basal elevations in IRS-1 phosphorylated at serine 616 (IRS-1 pS⁶¹⁶) and IRS-1 pS⁶³⁶/⁶³⁹. In the HF, these candidate biomarkers of brain insulin resistance increased commonly and progressively from normal cases to mild cognitively impaired cases to AD cases regardless of diabetes or APOE ε4 status. Levels of IRS-1 pS⁶¹⁶ and IRS-1 pS⁶³⁶/⁶³⁹ and their activated kinases correlated positively with those of oligomeric Aβ plaques and were negatively associated with episodic and working memory, even after adjusting for Aβ plaques, neurofibrillary tangles, and APOE ε4. Brain insulin resistance thus appears to be an early and common feature of AD, a phenomenon accompanied by IGF-1 resistance and closely associated with IRS-1 dysfunction potentially triggered by Aβ oligomers and yet promoting cognitive decline independent of classic AD pathology.
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Affiliation(s)
- Konrad Talbot
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-3403, USA.
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Abstract
Retinal ischemia is a common clinical entity and, due to relatively ineffective treatment, remains a common cause of visual impairment and blindness. Generally, ischemic syndromes are initially characterized by low homeostatic responses which, with time, induce injury to the tissue due to cell loss by apoptosis. In this respect, retinal ischemia is a primary cause of neuronal death. It can be considered as a sort of final common pathway in retinal diseases and results in irreversible morphological and functional changes. This review summarizes the recent knowledge on the effects of ischemia in retinal tissue and points out experimental strategies/models performed to gain better comprehension of retinal ischemia diseases. In particular, the nature of the mechanisms leading to neuronal damage (i.e., excess of glutamate release, oxidative stress and inflammation) will be outlined as well as the potential and most intriguing retinoprotective approaches and the possible therapeutic use of naturally occurring molecules such as neuropeptides. There is a general agreement that a better understanding of the fundamental pathophysiology of retinal ischemia will lead to better management and improved clinical outcome. In this respect, to contrast this pathological state, specific pharmacological strategies need to be developed aimed at the many putative cascades generated during ischemia.
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20
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Malla RR, Gopinath S, Gondi CS, Alapati K, Dinh DH, Tsung AJ, Rao JS. uPAR and cathepsin B downregulation induces apoptosis by targeting calcineurin A to BAD via Bcl-2 in glioma. J Neurooncol 2011; 107:69-80. [PMID: 21964739 DOI: 10.1007/s11060-011-0727-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 09/17/2011] [Indexed: 01/05/2023]
Abstract
Cathepsin B and urokinase plasminogen activator receptor (uPAR) are postulated to play key roles in glioma invasion. Calcineurin is one of the key regulators of mitochondrial-dependent apoptosis, but its mechanism is poorly understood. Hence, we studied subcellular localization of calcineurin after transcriptional downregulation of uPAR and cathepsin B in glioma. In the present study, efficient downregulation of uPAR and cathepsin B increased the translocation of calcineurin A from the mitochondria to the cytosol, decreased pBAD (S136) expression and its interaction with 14-3-3ζ and increased the interaction of BAD with Bcl-xl. Co-depletion of uPAR and cathepsin B induced mitochondrial translocation of BAD, activation of caspase 3 as well as PARP and cytochrome c and SMAC release. These effects were inhibited by FK506 (10 μM), a specific inhibitor of calcineurin. Calcineurin A was co-localized and also co-immunoprecipitated with Bcl-2. This interaction decreased with co-depletion of uPAR and cathepsin B and also with Bcl-2 inhibitor, HA 14-1 (20 μg/ml). Altered localization and interaction of calcineurin A with Bcl-2 was also observed in vivo when uPAR and cathepsin B were downregulated. In conclusion, downregulation of uPAR and cathepsin B induced apoptosis by targeting calcineurin A to BAD via Bcl-2 in glioma.
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Affiliation(s)
- Rama Rao Malla
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61605, USA
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Akundi RS, Zhi L, Büeler H. PINK1 enhances insulin-like growth factor-1-dependent Akt signaling and protection against apoptosis. Neurobiol Dis 2011; 45:469-78. [PMID: 21945539 DOI: 10.1016/j.nbd.2011.08.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 08/23/2011] [Accepted: 08/26/2011] [Indexed: 12/13/2022] Open
Abstract
Mutations in the PARK6 gene coding for PTEN-induced kinase 1 (PINK1) cause recessive early-onset Parkinsonism. Although PINK1 and Parkin promote the degradation of depolarized mitochondria in cultured cells, little is known about changes in signaling pathways that may additionally contribute to dopamine neuron loss in recessive Parkinsonism. Accumulating evidence implicates impaired Akt cell survival signaling in sporadic and familial PD (PD). IGF-1/Akt signaling inhibits dopamine neuron loss in several animal models of PD and both IGF-1 and insulin are neuroprotective in various settings. Here, we tested whether PINK1 is required for insulin-like growth factor 1 (IGF-1) and insulin dependent phosphorylation of Akt and the regulation of downstream Akt target proteins. Our results show that embryonic fibroblasts from PINK1-deficient mice display significantly reduced Akt phosphorylation in response to both IGF-1 and insulin. Moreover, phosphorylation of glycogen synthase kinase-3β (GSK-3β) and nuclear exclusion of FoxO1 are decreased in IGF-1 treated PINK1-deficient cells. In addition, phosphorylation of ribosomal protein S6 is reduced indicating decreased activity of mitochondrial target of rapamycin (mTOR) in IGF-1 treated PINK1(-/-) cells. Importantly, the protection afforded by IGF-1 against staurosporine-induced metabolic dysfunction and apoptosis is abrogated in PINK1-deficient cells. Moreover, IGF-1-induced Akt phosphorylation is impaired in primary cortical neurons from PINK1-deficient mice. Inhibition of cellular Ser/Thr phosphatases did not increase the amount of phosphorylated Akt in PINK1(-/-) cells, suggesting that components upstream of Akt phosphorylation are compromised in PINK1-deficient cells. Our studies show that PINK1 is required for optimal IGF-1 and insulin dependent Akt signal transduction, and raise the possibility that impaired IGF-1/Akt signaling is involved in PINK1-related Parkinsonism by increasing the vulnerability of dopaminergic neurons to stress-induced cell death.
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Affiliation(s)
- Ravi S Akundi
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
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22
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Ammoun S, Schmid MC, Zhou L, Ristic N, Ercolano E, Hilton DA, Perks CM, Hanemann CO. Insulin-like growth factor-binding protein-1 (IGFBP-1) regulates human schwannoma proliferation, adhesion and survival. Oncogene 2011; 31:1710-22. [PMID: 21892205 DOI: 10.1038/onc.2011.357] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Merlin is a tumour suppressor involved in the development of a variety of tumours including mesotheliomas. Neurofibromatosis type 2 (NF2), a dominantly inherited tumour disease, is also caused by loss of merlin. NF2 patients suffer from multiple genetically well-defined tumours, schwannomas are most frequent among those. Using our in vitro model for human schwannoma, we found that schwannoma cells display enhanced proliferation because of the overexpression/activation of platelet-derived growth factor receptor and ErbB2/3, increased cell-matrix adhesion because of the overexpression of integrins, and decreased apoptosis. Mechanisms underlying schwannomas basal proliferation and cell-matrix adhesion are not understood. Here, we investigated insulin-like growth factor-binding protein-1 (IGFBP-1), which is expressed and released from central nervous system tumours and strongly overexpressed in schwannoma at the mRNA level. IGFBP-1 acts via β1-integrin and focal-adhesion-kinase (FAK), which are strongly overexpressed and basally activated in schwannoma. Using short hairpin RNA knockdown, small inhibitors and recombinant IGFBP-1, we demonstrate that schwannoma cells, in contrast to Schwann cells, release IGFBP-1 that activates the Src/FAK pathway, via integrin β1, potentiating schwannoma's proliferation and cell-matrix adhesion. We show that FAK localizes to the nucleus and Src triggers IGFBP-1 production. Further, we observed downregulation of the tumour-suppressor phosphatase and tensin homolog in schwannoma cells leading to increased activity of anti-apoptotic AKT. Thus, IGFBP-1/integrin β1/Src/FAK pathway has a crucial role in merlin-related tumourigenesis and therefore represents an important therapeutic target in the treatment of merlin-deficient tumours.
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Affiliation(s)
- S Ammoun
- Clinical Neurobiology, Peninsula College for Medicine and Dentistry, Plymouth, UK
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SHIODA N, FUKUNAGA K. The Functional Roles of Constitutively Active Calcineurin in Delayed Neuronal Death after Brain Ischemia. YAKUGAKU ZASSHI 2011; 131:13-20. [DOI: 10.1248/yakushi.131.13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Norifumi SHIODA
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Kohji FUKUNAGA
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University
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24
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Mistafa O, Ghalali A, Kadekar S, Högberg J, Stenius U. Purinergic receptor-mediated rapid depletion of nuclear phosphorylated Akt depends on pleckstrin homology domain leucine-rich repeat phosphatase, calcineurin, protein phosphatase 2A, and PTEN phosphatases. J Biol Chem 2010; 285:27900-10. [PMID: 20605778 DOI: 10.1074/jbc.m110.117093] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Akt is an important oncoprotein, and data suggest a critical role for nuclear Akt in cancer development. We have previously described a rapid (3-5 min) and P2X7-dependent depletion of nuclear phosphorylated Akt (pAkt) and effects on downstream targets, and here we studied mechanisms behind the pAkt depletion. We show that cholesterol-lowering drugs, statins, or extracellular ATP, induced a complex and coordinated response in insulin-stimulated A549 cells leading to depletion of nuclear pAkt. It involved protein/lipid phosphatases PTEN, pleckstrin homology domain leucine-rich repeat phosphatase (PHLPP1 and -2), protein phosphatase 2A (PP2A), and calcineurin. We employed immunocytology, immunoprecipitation, and proximity ligation assay techniques and show that PHLPP and calcineurin translocated to the nucleus and formed complexes with Akt within 3 min. Also PTEN translocated to the nucleus and then co-localized with pAkt close to the nuclear membrane. An inhibitor of the scaffolding immunophilin FK506-binding protein 51 (FKBP51) and calcineurin, FK506, prevented depletion of nuclear pAkt. Furthermore, okadaic acid, an inhibitor of PP2A, prevented the nuclear pAkt depletion. Chemical inhibition and siRNA indicated that PHLPP, PP2A, and PTEN were required for a robust depletion of nuclear pAkt, and in prostate cancer cells lacking PTEN, transfection of PTEN restored the statin-induced pAkt depletion. The activation of protein and lipid phosphatases was paralleled by a rapid proliferating cell nuclear antigen (PCNA) translocation to the nucleus, a PCNA-p21(cip1) complex formation, and cyclin D1 degradation. We conclude that these effects reflect a signaling pathway for rapid depletion of pAkt that may stop the cell cycle.
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Affiliation(s)
- Oras Mistafa
- Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden
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Miyamoto S, Purcell NH, Smith JM, Gao T, Whittaker R, Huang K, Castillo R, Glembotski CC, Sussman MA, Newton AC, Brown JH. PHLPP-1 negatively regulates Akt activity and survival in the heart. Circ Res 2010; 107:476-84. [PMID: 20576936 DOI: 10.1161/circresaha.109.215020] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE The recently discovered PHLPP-1 (PH domain leucine-rich repeat protein phosphatase-1) selectively dephosphorylates Akt at Ser473 and terminates Akt signaling in cancer cells. The regulatory role of PHLPP-1 in the heart has not been considered. OBJECTIVE To test the hypothesis that blockade/inhibition of PHLPP-1 could constitute a novel way to enhance Akt signals and provide cardioprotection. METHODS AND RESULTS PHLPP-1 is expressed in neonatal rat ventricular myocytes (NRVMs) and in adult mouse ventricular myocytes (AMVMs). PHLPP-1 knockdown by small interfering RNA significantly enhances phosphorylation of Akt (p-Akt) at Ser473, but not at Thr308, in NRVMs stimulated with leukemia inhibitory factor (LIF). The increased phosphorylation is accompanied by greater Akt catalytic activity. PHLPP-1 knockdown enhances LIF-mediated cardioprotection against doxorubicin and also protects cardiomyocytes against H(2)O(2). Direct Akt effects at mitochondria have been implicated in cardioprotection and mitochondria/cytosol fractionation revealed a significant enrichment of PHLPP-1 at mitochondria. The ability of PHLPP-1 knockdown to potentiate LIF-mediated increases in p-Akt at mitochondria and an accompanying increase in mitochondrial hexokinase-II was demonstrated. We generated PHLPP-1 knockout (KO) mice and demonstrate that AMVMs isolated from KO mice show potentiated p-Akt at Ser473 in response to agonists. When isolated perfused hearts are subjected to ischemia/reperfusion, p-Akt in whole-heart homogenates and in the mitochondrial fraction is significantly increased. Additionally in PHLPP-1 KO hearts, the increase in p-Akt elicited by ischemia/reperfusion is potentiated and, concomitantly, infarct size is significantly reduced. CONCLUSIONS These results implicate PHLPP-1 as an endogenous negative regulator of Akt activity and cell survival in the heart.
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Affiliation(s)
- Shigeki Miyamoto
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0636, USA.
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The calcineurin inhibitor, FK506, does not alter glutamate transport in the ischaemic mouse retina. Exp Eye Res 2010; 91:315-9. [PMID: 20434440 DOI: 10.1016/j.exer.2010.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 04/21/2010] [Accepted: 04/22/2010] [Indexed: 11/20/2022]
Abstract
The protein phosphatase 2B inhibitor, FK506, is an immunomodulatory polypeptide that has neuroprotective properties, the mechanisms of which have not been elucidated. A possible mechanism may be phosphorylation-mediated regulation of glutamate transporter activity. In the present study, we investigated the effect of FK506 on glutamate transporter localization and activity in the ischaemic mouse retina. FK506 did not appear to modulate the localization or activity of glutamate transporters under simulated ischaemic conditions. Our present data suggest that the mechanism by which FK506 exerts its neuroprotective action is not attributable to alterations in retinal glutamate transport.
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Ma R, Wang X, Lu C, Li C, Cheng Y, Ding G, Liu L, Ding Z. Dexamethasone attenuated bupivacaine-induced neuron injury in vitro through a threonine–serine protein kinase B-dependent mechanism. Neuroscience 2010; 167:329-42. [DOI: 10.1016/j.neuroscience.2009.12.049] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 01/24/2023]
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Protection against chronic hypoperfusion-induced retinal neurodegeneration by PARP inhibition via activation of PI-3-kinase Akt pathway and suppression of JNK and p38 MAP kinases. Neurotox Res 2009; 16:68-76. [PMID: 19526300 DOI: 10.1007/s12640-009-9049-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 03/25/2009] [Accepted: 03/27/2009] [Indexed: 12/11/2022]
Abstract
Poly(ADP-ribose) polymerase (PARP) activation is considered as a major regulator of cell death in various pathophysiological conditions, however, no direct information is available about its role in chronic hypoperfusion-induced neuronal death. Here, we provide evidence for the protective effect of PARP inhibition on degenerative retinal damage induced by bilateral common carotid artery occlusion (BCCAO), an adequate chronic hypoperfusion murine model. We found that BCCAO in adult male Wistar rats led to severe degeneration of all retinal layers that was attenuated by a carboxaminobenzimidazol-derivative PARP inhibitor (HO3089) administered unilaterally into the vitreous body immediately following carotid occlusion and then 4 times in a 2-week-period. Normal morphological structure of the retina was preserved and the thickness of the retinal layers was increased in HO3089-treated eyes compared to the BCCAO eyes. For Western blot studies, HO3089 was administered immediately after BCCAO and retinas were removed 4 h later. According to Western blot analysis utilizing phosphorylation-specific primary antibodies, besides activating poly-ADP-ribose (PAR) synthesis, BCCAO induced phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). HO3089 inhibited PAR synthesis, and decreased the phosphorylation of these proapoptotic MAPKs. In addition, HO3089 treatment induced phosphorylation, that is activation, of the protective Akt/glycogen synthase kinase (GSK)-3beta and extracellular signal-regulated kinase (ERK1/2) signaling pathways. These data indicate that PARP activation has a major role in mediating chronic hypoperfusion-induced neuronal death, and inhibition of the enzyme prevents the pathological changes both in the morphology and the kinase signaling cascades involved. These results identify PARP inhibition as a possible molecular target in the clinical management of chronic hypoperfusion-induced neurodegenerative diseases including ocular ischemic syndrome.
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Pathophysiological relevance of forkhead transcription factors in brain ischemia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 665:130-42. [PMID: 20429421 DOI: 10.1007/978-1-4419-1599-3_10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Forkhead box transcription factor, class 0 (FOXO) is a mammalian homologue of DAF-16, which is known to regulate the lifespan of Caenorhabditis elegans and includes subfamiies of forkhead transcription factors such as FOXO1 (FKHR). FOXO3 (FKHRL1), FOXO4 (AFX) and FOXO6. All these FOXO members are expressed in the brain with different spatial patterns. FOXO1 is phosphorylated on three sites (Thr-24, Ser-256 and Ser-319) in phosphatidylinositol 3-kinase (PI3-K)/Akt-dependenr manner, thereby inhibiting apoptosis signals. We here documented dephosphorylation of FOXO1, FOXO3 and FOXO4 following transient forebrain ischemia with its concomitant translocation into the nucleus in neurons in the gerbil and mouse brains. The dephosphorylarion of FOXO1 following brain ischemia is in part mediated by constirutively active calcineurin in the mouse hippocampus. The activation of FOXOs preceded delayed neuronal death in the vulnerable hippocampal regions following ischemic brain injury. The FOXOl activation is accompanied by an increase in DNA binding activity for FOXO1-responsive element on the Fas ligand promoter. Thus, downstream targets induced by FOXOl include Fas ligand and Bcl-2-interacting mediator of cell death (Bim) in the brain ischemia. Accumulating evidence documented how FOXO activation is involved in the mechanisms of ischemic cell death. In this chapter, we document the activation mechanism of FOXO factors following brain ischemia and deline their downstream targets underlying neuronal death. The pathophysiological relevance of crosstalk between FOXOs and calcineurmn pathways is also discussed. Finally, we propose therapeutic perspectives to rescue neurons from delayed neuronal death by promoting the Akt signaling. Vanadium compounds, protein tyrosine phosphatase inhibitor, up-regulates Akt activity in the brain and thereby rescues neurons from delayed neuronal death by inhibiting FOXO-dependent and -independent death signals in neurons.
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