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Raggio M, Giaquinto D, Attanasio C, Palladino A, Esposito V, Radaelli G, De Felice E, Girolamo PD, D'Angelo L. Fasting duration impacts ribosome protein 6 phosphorylation in zebrafish brain: new insights in aquatic organisms' welfare. Ann Anat 2024:152266. [PMID: 38642855 DOI: 10.1016/j.aanat.2024.152266] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 04/22/2024]
Abstract
BACKGROUND Short- or mid-term fasting, full or partial, triggers metabolic response known to have in turn health effects in an organism. At central level, the metabolic stimulus triggered by fasting is known to be perceived firstly by hypothalamic neurons. In the field of neuroscience, ribosomal protein S6 (S6) phosphorylation is commonly used as a readout of the mammalian target of rapamycin complex 1 signalling activation or as a marker for neuronal activity. The aim of this study is addressed to evaluate whether the phosphorylation of S6 occurs in the central neurons of zebrafish exposed to four (short-term) and seven (mid-term) days of complete fasting. METHODS Group-housed adult zebrafish were exposed to four and seven days of complete food withdrawal. At the end of the experimental period, Western blotting analyses were carried out to measure the expression levels of the phosphorylated S6 (pS6) by comparing the two experimental conditions versus the control group. The same antibody was then used to identify the distribution pattern of pS6 immunoreactive neurons in the whole brain and in the taste buds. RESULTS We did not observe increased pS6 levels expression in the brain of animals exposed to short-term fasting compared to the control, whereas the expression increased in brain homogenates of animals exposed to mid-term fasting. pS6 immunoreactivity was reported in some hypothalamic neurons, as well as in the dorsal area of telencephalon and preoptic area, a neurosecretory region homolog to the mammalian paraventricular nucleus. Remarkably, we observed pS6 immunostaining in the sensory cells of taste buds lining the oral epithelium. CONCLUSIONS Taken together, our data show that in zebrafish, differently from other fish species, seven days of fasting triggers neuronal activity. Furthermore, the immunostaining on sensory cells of taste buds suggests that metabolic changes may modulate also peripheral sensory cells. This event may have valuable implications when using zebrafish to design metabolic studies involving fasting as well as practical consequences on the animal welfare, in particularly stressful conditions, such as transportation.
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Affiliation(s)
- Maria Raggio
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy
| | - Daniela Giaquinto
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy
| | - Chiara Attanasio
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy
| | - Antonio Palladino
- Department of Agricultural Science, University of Naples Federico II, Viale dell'Università, I-80055, Portici, Napoli, Italy
| | - Vincenzo Esposito
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy
| | - Giuseppe Radaelli
- Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy
| | - Elena De Felice
- School of Biosciences and Veterinary Medicine, University of Camerino, I-62032 Camerino, Italy
| | - Paolo de Girolamo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy
| | - Livia D'Angelo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Via F. Delpino, 1 I-80137, Naples Italy.
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Kim JK, Villa-Diaz LG, Saunders TL, Saul RP, Timilsina S, Liu F, Mishina Y, Krebsbach PH. Selective Inhibition of mTORC1 Signaling Supports the Development and Maintenance of Pluripotency. Stem Cells 2024; 42:13-28. [PMID: 37931173 PMCID: PMC10787279 DOI: 10.1093/stmcls/sxad079] [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: 08/12/2022] [Accepted: 10/23/2023] [Indexed: 11/08/2023]
Abstract
Insight into the molecular mechanisms governing the development and maintenance of pluripotency is important for understanding early development and the use of stem cells in regenerative medicine. We demonstrate the selective inhibition of mTORC1 signaling is important for developing the inner cell mass (ICM) and the self-renewal of human embryonic stem cells. S6K suppressed the expression and function of pluripotency-related transcription factors (PTFs) OCT4, SOX2, and KLF4 through phosphorylation and ubiquitin proteasome-mediated protein degradation, indicating that S6K inhibition is required for pluripotency. PTFs inhibited mTOR signaling. The phosphorylation of S6 was decreased in PTF-positive cells of the ICM in embryos. Activation of mTORC1 signaling blocked ICM formation and the selective inhibition of S6K by rapamycin increased the ICM size in mouse blastocysts. Thus, selective inhibition of mTORC1 signaling supports the development and maintenance of pluripotency.
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Affiliation(s)
- Jin Koo Kim
- Division of Oral and Systemic Health Sciences, University of California, Los Angeles School of Dentistry, Los Angeles, CA, USA
| | - Luis G Villa-Diaz
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
| | - Thomas L Saunders
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA
| | - Ruiz P Saul
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
| | | | - Fei Liu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Yuji Mishina
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Paul H Krebsbach
- Division of Oral and Systemic Health Sciences, University of California, Los Angeles School of Dentistry, Los Angeles, CA, USA
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Cornelis P, Dingemans J, Baysse C. Pseudomonas aeruginosa Soluble Pyocins as Antibacterial Weapons. Methods Mol Biol 2024; 2721:125-136. [PMID: 37819519 DOI: 10.1007/978-1-0716-3473-8_9] [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] [Indexed: 10/13/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial infections and associated with lung infections in cystic fibrosis (CF) patients (Lyczak et al., Microbes Infect 2:1051-1060, 2000). Multiple drug-resistant P. aeruginosa strains pose a serious problem because of antibiotic treatment failure. There is therefore a need for alternative anti-Pseudomonas molecules. Soluble pyocins (S-pyocins) are bacteriocins produced by P. aeruginosa strains that kill sensitive strains of the same species. These bacteriocins and their immunity gene are easily cloned and expressed in E. coli and their activity spectrum against different P. aeruginosa strains can be tested. In this chapter, we describe the procedures for cloning, expression, and sensitivity testing of two different S-pyocins. We also describe how to identify their receptor binding domain in sensitive strains, how to construct chimeric pyocins with extended activity spectra, and how to identify new pyocins in genomes by multiplex PCR.
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Affiliation(s)
- Pierre Cornelis
- Vrije Universiteit Brussel, Microbiology Group, Brussels, Belgium.
| | - Jozef Dingemans
- Vrije Universiteit Brussel, Microbiology Group, Brussels, Belgium
| | - Christine Baysse
- Institut de Génétique et de Développement de Rennes (IGDR), CNRS UMR 6290, Université de Rennes, Rennes, France
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Miyanishi K, Nururrozi A, Igase M, Tanabe M, Sakurai M, Sakai Y, Shimonohara N, Murakami M, Mizuno T. Activation of the Akt signalling pathway as a prognostic indicator in canine soft tissue sarcoma. J Comp Pathol 2023; 206:44-52. [PMID: 37839309 DOI: 10.1016/j.jcpa.2023.08.007] [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: 01/12/2023] [Revised: 04/18/2023] [Accepted: 08/31/2023] [Indexed: 10/17/2023]
Abstract
Canine soft tissue sarcoma (STS) is relatively common in dogs and is the generic term for tumours that originate from mesenchymal cells. While histopathological grade and immunolabelling with Ki-67 have been used for estimating prognosis, additional indicators are needed for predicting prognosis. Aberrant cell signalling pathways may contribute to disease activity and, therefore, prognostic markers. However, their role in canine STS remains poorly understood. The aim of this study was to investigate expression of phosphorylated Akt (phospho-Akt) and phosphorylated S6 (phospho-S6) as potential prognostic indicators. Immunohistochemical labelling was conducted on clinical samples of canine STS (n = 67). We found that phospho-Akt expression was positively correlated with histopathological grade (P = 0.001) and Ki-67 index (P <0.01). There was no apparent relationship between the type of STS and the expression of phospho-Akt. The number of cases that expressed phospho-S6, which is the downstream molecule of the Akt signalling pathway, was higher in immunopositive phospho-Akt cases than in immunonegative phospho-Akt cases (P <0.0001). Furthermore, phospho-Akt expression was significantly higher in recurrent and metastatic cases. We also confirmed that phosphorylation of Akt occurred in conjunction with S6 phosphorylation in three canine STS cell lines. These results suggest that immunolabelling for phospho-Akt, phospho-S6 and Ki-67 could potentially be used as a prognostic indicator and therapeutic target in canine STS.
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Affiliation(s)
- Kyohei Miyanishi
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Alfarisa Nururrozi
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Masaya Igase
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Mika Tanabe
- Veterinary Pathology Diagnostic Center, Fukuoka, Japan
| | - Masashi Sakurai
- Laboratory of Veterinary Pathology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yusuke Sakai
- Laboratory of Veterinary Pathology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | | | - Mami Murakami
- Laboratory of Veterinary Clinical Oncology, Joint Department of Veterinary Medicine, Gifu University, Gifu, Japan
| | - Takuya Mizuno
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan.
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Ring NAR, Dworak H, Bachmann B, Schädl B, Valdivieso K, Rozmaric T, Heimel P, Fischer I, Klinaki E, Gutasi A, Schuetzenberger K, Leinfellner G, Ferguson J, Drechsler S, Mildner M, Schosserer M, Slezak P, Meyuhas O, Gruber F, Grillari J, Redl H, Ogrodnik M. The p-rp S6-zone delineates wounding responses and the healing process. Dev Cell 2023:S1534-5807(23)00154-5. [PMID: 37098351 DOI: 10.1016/j.devcel.2023.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/31/2023] [Accepted: 04/01/2023] [Indexed: 04/27/2023]
Abstract
The spatial boundaries of tissue response to wounding are unknown. Here, we show that in mammals, the ribosomal protein S6 (rpS6) is phosphorylated in response to skin injury, forming a zone of activation surrounding the region of the initial insult. This p-rpS6-zone forms within minutes after wounding and is present until healing is complete. The zone is a robust marker of healing as it encapsulates features of the healing process, including proliferation, growth, cellular senescence, and angiogenesis. A mouse model that is unable to phosphorylate rpS6 shows an initial acceleration of wound closure, but results in impaired healing, identifying p-rpS6 as a modulator but not a driver of healing. Finally, the p-rpS6-zone accurately reports on the status of dermal vasculature and the effectiveness of healing, visually dividing an otherwise homogeneous tissue into regions with distinct properties.
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Affiliation(s)
- Nadja Anneliese Ruth Ring
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Helene Dworak
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Barbara Bachmann
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Barbara Schädl
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria; University Clinic of Dentistry, Medical University of Vienna, 1090 Vienna, Austria
| | - Karla Valdivieso
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria; Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, 1180 Vienna, Austria
| | - Tomaz Rozmaric
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Patrick Heimel
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria; Core Facility Hard Tissue and Biomaterial Research, Karl Donath Laboratory, University Clinic of Dentistry, Medical University of Vienna, 1090 Vienna, Austria
| | - Ines Fischer
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Eirini Klinaki
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Aniko Gutasi
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Kornelia Schuetzenberger
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Gabriele Leinfellner
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - James Ferguson
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Susanne Drechsler
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Michael Mildner
- Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
| | - Markus Schosserer
- Austrian Cluster for Tissue Regeneration, Vienna, Austria; Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, 1180 Vienna, Austria; Institute of Medical Genetics, Center for Pathobiochemistry and Genetics, Medical University of Vienna, 1090 Vienna, Austria
| | - Paul Slezak
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, 91120 Jerusalem, Israel
| | - Florian Gruber
- Austrian Cluster for Tissue Regeneration, Vienna, Austria; Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
| | - Johannes Grillari
- Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria; Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, 1180 Vienna, Austria
| | - Heinz Redl
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Mikolaj Ogrodnik
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds, 1200 Vienna, Austria; Ludwig Boltzmann Institute for Traumatology, The Research Centre in Cooperation with AUVA, 1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria.
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Hu J, Ling Z, Li W, Su Z, Lu J, Zeng Q, Cheng B, Tao X. Glutamine promotes the proliferation of epithelial cells via mTOR/ S6 pathway in oral lichen planus. J Oral Pathol Med 2023; 52:150-160. [PMID: 36459062 DOI: 10.1111/jop.13391] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND Although abnormal cell proliferation and apoptosis are associated with the pathogenesis of oral lichen planus (OLP), the exactly mechanism of which is not yet known. It has been reported that glutamine (Gln) can promote cell proliferation and inhibit apoptosis of various tumor cells. This study aims to evaluate the effect of Gln metabolism on the balance of proliferation and apoptosis in epithelial cells of OLP. METHODS Thirty human OLP specimens and 11 normal controls were stained by immunohistochemistry to detect the levels of proliferation and Gln metabolism related proteins. Then, the critical role of Gln in cell proliferation and apoptosis was determined by Gln deprivation or treatment with glutaminase inhibitor (CB-839) to intervene Gln metabolism in human gingival epithelial cells. Cell proliferation was detected using CCK8, p-mTOR and p-S6 proteins were detected using Western Blot, cell apoptosis and cell cycle were detected using flow cytometry, and cell stress was detected using immunofluorescence. RESULTS Compared with normal controls, OLP specimens showed higher levels of Ki-67 and Gln metabolism-related proteins, including Gln transporter (ASCT2), glutaminase (GLS), and pathway proteins (p-mTOR and p-S6). In vitro, Gln promoted cell proliferation and simultaneously upregulated the activity of mTOR/S6 pathway. Moreover, rapamycin, an mTOR pathway inhibitor, could effectively block the Gln-induced cell proliferation. MHY1485, an mTOR pathway agonist, could effectively reverse the decline of cell proliferation under Gln deprivation. In addition, inhibiting Gln metabolism caused the accumulation of intracellular radical oxygen species (ROS) and induced cell apoptosis. However, N-acetylcysteine reversed this state and then decreased cell apoptosis by eliminating intracellular ROS. CONCLUSION Gln metabolism is essential to maintain the balance of proliferation and apoptosis in oral epithelial cells, and inhibition of Gln metabolism may have a beneficial effect on OLP treatment.
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Affiliation(s)
- Jiaqi Hu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Zihang Ling
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Wei Li
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Zhangci Su
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Jingyi Lu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Qi Zeng
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Bin Cheng
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xiaoan Tao
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
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Ruff A, Lewis M, Whalen M. Organotin and organochlorine toxicants activate key translational regulatory proteins in human immune cells. Arch Toxicol 2023; 97:469-493. [PMID: 36372856 PMCID: PMC9939003 DOI: 10.1007/s00204-022-03413-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 10/03/2022] [Accepted: 11/03/2022] [Indexed: 11/15/2022]
Abstract
Environmental contaminant exposures occur due to the widespread use of synthetic chemicals. Tributyltin (TBT), dibutyltin (DBT), and pentachlorophenol (PCP) are each used in a variety of applications, including antifouling paints and stabilizers in certain plastics. Each of these compounds has been found in human blood, as well as other tissues, and they have been shown to stimulate pro-inflammatory cytokine production in human immune cells, Inflammatory cytokines mediate response to injury or infection. However, if their levels are increased in the absence of an appropriate stimulus, chronic inflammation can occur. Chronic inflammation is associated with a number of pathologies including cancer. Stimulation of pro-inflammatory cytokine production by these toxicants is dependent on activation of ERK 1/2 and/or p38 MAPK pathways. MAPK pathways have the capacity to regulate translation by increasing phosphorylation of key translation regulatory proteins. There have been no previous studies examining the effects of TBT, DBT, or PCP on translation. The current study shows that ribosomal protein S6 (S6), eukaryotic initiation factor 4B (eIF4B), and eIF4E are phosphorylated (activated) and/or their total levels are elevated in response to each of these compounds at concentrations found in human blood. Activation/increased levels of translational proteins occurred at concentrations of the compounds that have been shown to elevate pro-inflammatory cytokine production, but where there is no increase in mRNA for those proteins was seen. Compound-stimulated increases in translation appear to be part of the mechanism by which they elevate protein production in immune cells.
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Affiliation(s)
- Amanda Ruff
- Department of Biology, Tennessee State University, Nashville, TN, 37209, USA
| | - Meaghan Lewis
- Department of Biology, Tennessee State University, Nashville, TN, 37209, USA
| | - Margaret Whalen
- Department of Chemistry, Tennessee State University, 3500 John A. Merritt Blvd., Nashville, TN, 37209, USA.
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Alkashgari HR, Ruiz-Jimenez C, Stoian C, Coats JS, Baez I, Chirshev E, Martinez SR, Dovat S, Francis-Boyle OL, Casiano CA, Payne KJ. TSLP as a Potential Therapy in the Treatment of CRLF2 B Cell Acute Lymphoblastic Leukemia. Int J Mol Sci 2022; 24:474. [PMID: 36613920 PMCID: PMC9820664 DOI: 10.3390/ijms24010474] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
Cytokine receptor-like factor 2 B-cell acute lymphoblastic leukemia (CRLF2 B-ALL) is a high-risk subtype characterized by CRLF2 overexpression with poor survival rates in children and adults. CRLF2 and interleukin-7 receptor alpha (IL-7Rα) form a receptor for the cytokine thymic stromal lymphopoietin (TSLP), which induces JAK/STAT and PI3K/AKT/mTOR pathway signals. Previous studies from our group showed that low TSLP doses increased STAT5, AKT, and S6 phosphorylation and contributed to CRLF2 B-ALL cell survival. Here we investigated the role of TSLP in the survival and proliferation of CRLF2 B-ALL cells in vitro and in vivo. We hypothesized that high doses of TSLP increase CRLF2 signals and contribute to increased proliferation of CRLF2 B-ALL cells in vitro and in vivo. Interestingly, we observed the opposite effect. Specifically, high doses of TSLP induced apoptosis in human CRLF2 B-ALL cell lines in vitro, prevented engraftment of CRLF2 B-ALL cells, and prolonged the survival of +TSLP patient-derived-xenograft mice. Mechanistically, we showed that high doses of TSLP induced loss of its receptor and loss of CRLF2 signals in vitro. These results suggest that high doses of TSLP could be further investigated as a potential therapy for the treatment of CRLF2 B-ALL.
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Affiliation(s)
- Hossam R. Alkashgari
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
- Department of Physiology, College of Medicine, University of Jeddah, Jeddah 23890, Saudi Arabia
| | - Caleb Ruiz-Jimenez
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Cornelia Stoian
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Jacqueline S. Coats
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Ineavely Baez
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Evgeny Chirshev
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Shannalee R. Martinez
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Sinisa Dovat
- College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA
| | - Olivia L. Francis-Boyle
- Department of Pharmaceutical and Administrative Sciences, School of Pharmacy, Loma Linda University, Loma Linda, CA 92354, USA
- Department of Pathology & Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Carlos A. Casiano
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
- Rheumatology Division, Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Kimberly J. Payne
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
- Department of Pathology & Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
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Liu K, Peng Y, Lin L, Gong Z, Xiao W, Li Y. L-Theanine Regulates the Abundance of Amino Acid Transporters in Mice Duodenum and Jejunum via the mTOR Signaling Pathway. Nutrients 2022; 15. [PMID: 36615799 DOI: 10.3390/nu15010142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/20/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
The intestine is a key organ for the absorption of amino acids. L-theanine (LTA) is a structural analog of glutamine and a characteristic non-protein amino acid found in tea (Camellia sinensis) that regulates lipid and protein metabolism. The present study explored the role of LTA in intestinal amino acid absorption, protein synthesis, and its mechanisms. Overall, our findings suggest that LTA supplementation not only affects serum alkaline phosphatase (AKP), total protein (TP), and urea nitrogen (BUN) levels, but it also upregulates the mRNA and protein expression of amino acid transporters (EAAT3, EAAT1, 4F2hc, y+LAT1, CAT1, ASCT2, and B0AT1), and activates the mTOR signaling pathway. The downstream S6 and S6K1 proteins are regulated, and the expression of amino acid transporters is regulated. These findings suggest that LTA increases intestinal AA absorption, promotes protein metabolism, and increases nitrogen utilization by upregulating AAT expression, activating the mTOR signaling pathway, and phosphorylating the mTOR downstream proteins S6 and S6K1.
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Petrikis P, Polyzou A, Premeti K, Roumelioti A, Karampas A, Georgiou G, Grigoriadis D, Leondaritis G. GSK3β and mTORC1 Represent 2 Distinct Signaling Markers in Peripheral Blood Mononuclear Cells of Drug-Naive, First Episode of Psychosis Patients. Schizophr Bull 2022; 48:1136-1144. [PMID: 35757972 PMCID: PMC9434466 DOI: 10.1093/schbul/sbac069] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND AND HYPOTHESIS Schizophrenia is characterized by a complex interplay between genetic and environmental risk factors converging on prominent signaling pathways that orchestrate brain development. The Akt/GSK3β/mTORC1 pathway has long been recognized as a point of convergence and etiological mechanism, but despite evidence suggesting its hypofunction, it is still not clear if this is already established during the first episode of psychosis (FEP). STUDY DESIGN Here, we performed a systematic phosphorylation analysis of Akt, GSK3β, and S6, a mTORC1 downstream target, in fresh peripheral blood mononuclear cells from drug-naive FEP patients and control subjects. STUDY RESULTS Our results suggest 2 distinct signaling endophenotypes in FEP patients. GSK3β hypofunction exhibits a promiscuous association with psychopathology, and it is normalized after treatment, whereas mTORC1 hypofunction represents a stable state. CONCLUSIONS Our study provides novel insight on the peripheral hypofunction of the Akt/GSK3β/mTORC1 pathway and highlights mTORC1 activity as a prominent integrator of altered peripheral immune and metabolic states in FEP patients.
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Affiliation(s)
| | - Alexandra Polyzou
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Kyriaki Premeti
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Argyro Roumelioti
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Andreas Karampas
- Department of Psychiatry, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Georgios Georgiou
- Department of Psychiatry, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Dionysios Grigoriadis
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Cambridgeshire, UK
| | - George Leondaritis
- To whom correspondence should be addressed; Department of Pharmacology, Faculty of Medicine, School of Health Sciences and Institute of Biosciences, University Research Center of Ioannina, 45110 Ioannina, Greece; tel: +302651007555, fax: +302651007859, e-mail:
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11
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Liu YJ, Kuo HC, Chern Y. A system-wide mislocalization of RNA-binding proteins in motor neurons is a new feature of ALS. Neurobiol Dis 2021; 160:105531. [PMID: 34634461 DOI: 10.1016/j.nbd.2021.105531] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 01/01/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by progressive degeneration of motor neurons. Mislocalization of TAR DNA-binding protein 43 (TDP-43) is an early event in the formation of cytoplasmic TDP-43-positive inclusions in motor neurons and a hallmark of ALS. However, the underlying mechanism and the pathogenic impact of this mislocalization are relatively unexplored. We previously reported that abnormal AMPK activation mediates TDP-43 mislocalization in motor neurons of humans and mice with ALS. In the present study, we hypothesized that other nuclear proteins are mislocalized in the cytoplasm of motor neurons due to the AMPK-mediated phosphorylation of importin-α1 and subsequently contribute to neuronal degeneration in ALS. To test this hypothesis, we analyzed motor neurons of sporadic ALS patients and found that when AMPK is activated, importin-α1 is abnormally located in the nucleus. Multiple integrative molecular and cellular approaches (including proteomics, immunoprecipitation/western blot analysis, immunohistological evaluations and gradient analysis of preribosomal complexes) were employed to demonstrate that numerous RNA binding proteins are mislocalized in a rodent motor neuron cell line (NSC34) and human motor neurons derived from iPSCs during AMPK activation. We used comparative proteomic analysis of importin-α1 complexes that were immunoprecipitated with a phosphorylation-deficient mutant of importin-α1 (importin-α1-S105A) and a phosphomimetic mutant of importin-α1 (importin-α1-S105D) to identify 194 proteins that have stronger affinity for the unphosphorylated form than the phosphorylated form of importin-α1. Furthermore, GO and STRING analyses suggested that RNA processing and protein translation is the major machinery affected by abnormalities in the AMPK-importin-α1 axis. Consistently, the expression of importin-α1-S105D alters the assembly of preribosomal complexes and increases cell apoptosis. Collectively, we propose that by impairing importin-α1-mediated nuclear import, abnormal AMPK activation in motor neurons alters the cellular distribution of many RNA-binding proteins, which pathogenically affect multiple cellular machineries in motor neurons and contribute to ALS pathogenesis.
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Affiliation(s)
- Yu-Ju Liu
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hung-Chih Kuo
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
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12
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Moya NA, Tanner MK, Smith AM, Balolia A, Davis JKP, Bonar K, Jaime J, Hubert T, Silva J, Whitworth W, Loetz EC, Bland ST, Greenwood BN. Acute exercise enhances fear extinction through a mechanism involving central mTOR signaling. Neurobiol Learn Mem 2020; 176:107328. [PMID: 33075479 PMCID: PMC7718627 DOI: 10.1016/j.nlm.2020.107328] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 04/10/2020] [Revised: 09/12/2020] [Accepted: 10/13/2020] [Indexed: 01/02/2023]
Abstract
Impaired fear extinction, combined with the likelihood of fear relapse after exposure therapy, contributes to the persistence of many trauma-related disorders such as anxiety and post-traumatic stress disorder. Identifying mechanisms to aid fear extinction and reduce relapse could provide novel strategies for augmentation of exposure therapy. Exercise can enhance learning and memory and augment fear extinction of traumatic memories in humans and rodents. One factor that could contribute to enhanced fear extinction following exercise is the mammalian target of rapamycin (mTOR). mTOR is a translation regulator involved in synaptic plasticity and is sensitive to many exercise signals such as monoamines, growth factors, and cellular metabolism. Further, mTOR signaling is increased after chronic exercise in brain regions involved in learning and emotional behavior. Therefore, mTOR is a compelling potential facilitator of the memory-enhancing and overall beneficial effects of exercise on mental health.The goal of the current study is to test the hypothesis that mTOR signaling is necessary for the enhancement of fear extinction produced by acute, voluntary exercise. We observed that intracerebral-ventricular administration of the mTOR inhibitor rapamycin reduced immunoreactivity of phosphorylated S6, a downstream target of mTOR, in brain regions involved in fear extinction and eliminated the enhancement of fear extinction memory produced by acute exercise, without reducing voluntary exercise behavior or altering fear extinction in sedentary rats. These results suggest that mTOR signaling contributes to exercise-augmentation of fear extinction.
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Affiliation(s)
- Nicolette A Moya
- Department of Psychology, University of Colorado Denver, USA; Department of Integrative Biology, University of Colorado Denver, USA
| | - Margaret K Tanner
- Department of Psychology, University of Colorado Denver, USA; Department of Integrative Biology, University of Colorado Denver, USA
| | - Abigail M Smith
- Department of Psychology, University of Colorado Denver, USA
| | - Aleezah Balolia
- Department of Psychology, University of Colorado Denver, USA; Department of Integrative Biology, University of Colorado Denver, USA
| | | | - Kelsey Bonar
- Department of Psychology, University of Colorado Denver, USA
| | - Jennifer Jaime
- Department of Psychology, University of Colorado Denver, USA
| | - Troy Hubert
- Department of Psychology, University of Colorado Denver, USA
| | - Jorge Silva
- Department of Psychology, University of Colorado Denver, USA
| | | | - Esteban C Loetz
- Department of Psychology, University of Colorado Denver, USA
| | - Sondra T Bland
- Department of Psychology, University of Colorado Denver, USA
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13
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Li K, Shen X, Qiu H, Zhao T, Ai K, Li C, Zhang Y, Li K, Duan M, Wei X, Yang J. S6K1/S6 axis-regulated lymphocyte activation is important for adaptive immune response of Nile tilapia. Fish Shellfish Immunol 2020; 106:1120-1130. [PMID: 32971270 DOI: 10.1016/j.fsi.2020.09.031] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/10/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
Ribosomal protein S6 kinase beta-1 (S6K1) is a serine/threonine kinase downstream of the mechanistic target of rapamycin (mTOR) pathway, and plays crucial roles in immune regulation. Although remarkable progress has been achieved with a mouse model, how S6K1 regulates adaptive immunity is largely unknown in early vertebrates. In this study, we identified an S6K1 from Nile tilapia Oreochromis niloticus (OnS6K1), and further investigated its potential regulatory role on the adaptive immunity of this fish species. Both sequence and structure of OnS6K1 were highly conserved with its homologs from other vertebrates and invertebrates. OnS6K1 was widely expressed in immune tissues, and with a relative higher expression level in the liver, spleen and head kidney. At the adaptive immune stage of Nile tilapia that infected with Aeromonas hydrophila, mRNA expression of OnS6K1 and its downstream effector S6 was significantly up-regulated in spleen lymphocytes. Meanwhile, their phosphorylation level was also enhanced during this process, suggesting that S6K1/S6 axis participated in the primary response of anti-bacterial adaptive immunity in Nile tilapia. Furthermore, after spleen lymphocytes were activated by the T cell-specific mitogen PHA or lymphocytes agonist PMA in vitro, mRNA and phosphorylation levels of S6K1 were elevated, and phosphorylation of S6 was also enhanced. Once S6K1 activity was blocked by a specific inhibitor, both mRNA and phosphorylation levels of S6 were severely impaired. More importantly, blockade of S6K1/S6 axis reduced the expression of T cell activation marker IFN-γ and CD122 in PHA-activated spleen lymphocytes, indicating the essential role of S6K1/S6 axis in regulating T cell activation of Nile tilapia. Together, our study suggests that S6K1 and its effector S6 regulate lymphocyte activation of Nile tilapia, and in turn promote lymphocyte-mediated adaptive immunity. This study enriched the mechanism of adaptive immune response in teleost and provided useful clues to understand the evolution of adaptive immune system.
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Affiliation(s)
- Kunming Li
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Xiaotong Shen
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Hong Qiu
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Tianyu Zhao
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Kete Ai
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Cheng Li
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yu Zhang
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Kang Li
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Ming Duan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, Hubei, China.
| | - Xiumei Wei
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China.
| | - Jialong Yang
- State Key Laboratory of Estuarine and Coastal Research, School of Life Sciences, East China Normal University, Shanghai, 200241, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
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14
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Litchfield LM, Boehnke K, Brahmachary M, Mur C, Bi C, Stephens JR, Sauder JM, Gutiérrez SM, McNulty AM, Ye XS, Wu W, Lallena MJ, Gong X, Merzoug FF, Jansen VM, Buchanan SG. Combined inhibition of PIM and CDK4/6 suppresses both mTOR signaling and Rb phosphorylation and potentiates PI3K inhibition in cancer cells. Oncotarget 2020; 11:1478-92. [PMID: 32391118 DOI: 10.18632/oncotarget.27539] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 03/14/2020] [Indexed: 12/31/2022] Open
Abstract
Aberrant activation of mitogenic signaling pathways in cancer promotes growth and proliferation of cells by activating mTOR and S6 phosphorylation, and D-cyclin kinases and Rb phosphorylation, respectively. Correspondingly, inhibition of phosphorylation of both Rb and S6 is required for robust anti-tumor efficacy of drugs that inhibit cell signaling. The best-established mechanism of mTOR activation in cancer is via PI3K/Akt signaling, but mTOR activity can also be stimulated by CDK4 and PIM kinases. In this study, we show that the CDK4/6 inhibitor abemaciclib inhibits PIM kinase and S6 phosphorylation in cancer cells and concurrent inhibition of PIM, CDK4, and CDK6 suppresses both S6 and Rb phosphorylation. TSC2 or PIK3CA mutations obviate the requirement for PIM kinase and circumvent the inhibition of S6 phosphorylation by abemaciclib. Combination with a PI3K inhibitor restored suppression of S6 phosphorylation and synergized to curtail cell growth. By combining abemaciclib with a PI3K inhibitor, three pathways (Akt, PIM, and CDK4) to mTOR activation are neutralized, suggesting a potential combination strategy for the treatment of PIK3CA-mutant ER+ breast cancer.
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15
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Glasgow SD, Wong EW, Thompson-Steckel G, Marcal N, Séguéla P, Ruthazer ES, Kennedy TE. Pre- and post-synaptic roles for DCC in memory consolidation in the adult mouse hippocampus. Mol Brain 2020; 13:56. [PMID: 32264905 PMCID: PMC7137442 DOI: 10.1186/s13041-020-00597-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/26/2020] [Indexed: 11/10/2022] Open
Abstract
The receptor deleted in colorectal cancer (DCC) and its ligand netrin-1 are essential for axon guidance during development and are expressed by neurons in the mature brain. Netrin-1 recruits GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and is critical for long-term potentiation (LTP) at CA3-CA1 hippocampal Schaffer collateral synapses, while conditional DCC deletion from glutamatergic neurons impairs hippocampal-dependent spatial memory and severely disrupts LTP induction. DCC co-fractionates with the detergent-resistant component of postsynaptic density, yet is enriched in axonal growth cones that differentiate into presynaptic terminals during development. Specific presynaptic and postsynaptic contributions of DCC to the function of mature neural circuits have yet to be identified. Employing hippocampal subregion-specific conditional deletion of DCC, we show that DCC loss from CA1 hippocampal pyramidal neurons resulted in deficits in spatial memory, increased resting membrane potential, abnormal dendritic spine morphology, weaker spontaneous excitatory postsynaptic activity, and reduced levels of postsynaptic adaptor and signaling proteins; however, the capacity to induce LTP remained intact. In contrast, deletion of DCC from CA3 neurons did not induce detectable changes in the intrinsic electrophysiological properties of CA1 pyramidal neurons, but impaired performance on the novel object place recognition task as well as compromised excitatory synaptic transmission and LTP at Schaffer collateral synapses. Together, these findings reveal specific pre- and post-synaptic contributions of DCC to hippocampal synaptic plasticity underlying spatial memory.
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Affiliation(s)
- Stephen D Glasgow
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada.,NSERC CREATE Neuroengineering Training Program, McGill University, Montréal, Canada
| | - Edwin W Wong
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada
| | - Greta Thompson-Steckel
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada
| | - Nathalie Marcal
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada
| | - Philippe Séguéla
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada
| | - Edward S Ruthazer
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada
| | - Timothy E Kennedy
- Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada. .,NSERC CREATE Neuroengineering Training Program, McGill University, Montréal, Canada. .,Department of Anatomy and Cell Biology, McGill University, 3640 Rue University, Montreal, Quebec, H3A 0C7, Canada.
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16
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Petit V, Raymond J, Alberti C, Pouteaux M, Gallagher SJ, Nguyen MQ, Aplin AE, Delmas V, Larue L. C57BL/6 congenic mouse NRAS Q61K melanoma cell lines are highly sensitive to the combination of Mek and Akt inhibitors in vitro and in vivo. Pigment Cell Melanoma Res 2019; 32:829-841. [PMID: 31251472 DOI: 10.1111/pcmr.12807] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/30/2019] [Accepted: 06/25/2019] [Indexed: 12/30/2022]
Abstract
RAS is frequently mutated in various tumors and known to be difficult to target. NRASQ61K/R are the second most frequent mutations found in human skin melanoma after BRAFV600E . Aside from surgery, various approaches, including targeted therapies, immunotherapies, and combination therapies, are used to treat patients carrying NRAS mutations, but they are inefficient. Here, we established mouse NRASQ61K melanoma cell lines and genetically derived isografts (GDIs) from Tyr::NRASQ61K mouse melanoma that can be used in vitro and in vivo in an immune-competent environment (C57BL/6) to test and discover novel therapies. We characterized these cell lines at the cellular, molecular, and oncogenic levels and show that NRASQ61K melanoma is highly sensitive to the combination of Mek and Akt inhibitors. This preclinical model shows much potential for the screening of novel therapeutic strategies for patients harboring NRAS mutations that have limited therapeutic options and resulted in poor prognoses.
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Affiliation(s)
- Valérie Petit
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Jeremy Raymond
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Christophe Alberti
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Marie Pouteaux
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Stuart J Gallagher
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Mai Q Nguyen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Andrew E Aplin
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, USA.,Sidney Kimmel Cancer Center, Philadelphia, PA, USA
| | - Véronique Delmas
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Lionel Larue
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
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17
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Shi J, Zhang W, He L, Kong F, Pan M, Guo J, Xu X, Guo J, Wang H, Wang Y. Jinlong capsule inhibits migration and invasion in human glioblastoma cells via the modulation of mTOR/ S6 signaling pathway. Drug Des Devel Ther 2019; 13:1023-1032. [PMID: 31114156 PMCID: PMC6497872 DOI: 10.2147/dddt.s195409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/21/2019] [Indexed: 02/06/2023]
Abstract
Aim: To investigate the anticancer effects of Jinlong capsule (JLC) against human glioblastoma cells and the possible underlying mechanism. Methods: Cell Counting Kit-8 and colony formation assay were adopted for the analysis of cell viability. Cell invasion and migration were evaluated by transwell and wound healing assays. Then, the expression level of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), S6 and phosphorylated S6 (p-S6) were determined by western blotting. Results: The results showed that JLC significantly inhibited human glioblastoma cell proliferation, invasion and migration in a dose-dependent manner. The expressions of p-mTOR and p-S6 were dramatically suppressed by JLC. Furtherly, inhibition of mTOR reduced the cell migration and invasion, while the mTOR agonist (MHY1485) could partially reverse the anti-migration and anti-invasion activity of JLC. Conclusion: The above results suggested that JLC would be a potential candidate for the treatment of glioblastoma.
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Affiliation(s)
- Jingren Shi
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Wenli Zhang
- Department of Clinical Laboratory, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, People's Republic of China
| | - Lu He
- Department of Clinical Laboratory, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, People's Republic of China
| | - Fanhong Kong
- Department of Clinical Laboratory, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, People's Republic of China
| | - Meichen Pan
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Jingjing Guo
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Xinmin Xu
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Jie Guo
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Huizhu Wang
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
| | - Yajie Wang
- Department of Clinical Laboratory, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, People's Republic of China
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18
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Kanaizumi H, Higashi C, Tanaka Y, Hamada M, Shinzaki W, Azumi T, Hashimoto Y, Inui H, Houjou T, Komoike Y. PI3K/Akt/mTOR signalling pathway activation in patients with ER-positive, metachronous, contralateral breast cancer treated with hormone therapy. Oncol Lett 2018; 17:1962-1968. [PMID: 30675261 DOI: 10.3892/ol.2018.9759] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/31/2018] [Indexed: 01/12/2023] Open
Abstract
Oestrogen receptor (ER)-positive, metachronous, contralateral breast cancer (MCBC) sometimes develops during or soon after completion of hormone therapy (HT), but it is uncertain whether it is HT-resistant. We examined the association between ER-positive second cancer and activation of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) pathways, which are associated with HT resistance. We examined the treatment-free interval (time after completion of HT for initial cancer) in 41 patients with ER-positive MCBC with a history of adjuvant HT for initial cancer (HT group), and initial-to-second period duration (time after operation of initial cancer to onset of second cancer) in 17 patients with ER-positive MCBC in whom adjuvant HT was not applied to the initial tumour (control group or no HT group). Phosphorylated S6 (pS6) and phosphorylated MAPK (pMAPK) were used as indicators of PI3K/Akt/mTOR and MAPK pathway activity, respectively. Tumours were classified as showing negative, positive or strongly positive staining, and the correlation between staining and treatment-free interval or initial-to-second period duration was evaluated using the Spearman's rank correlation coefficient (ρ). Treatment-free interval and pS6 staining showed a negative correlation (ρ=-0.5355; P=0.0003) in the HT group. There was no correlation between initial-to-second period duration and pS6 staining in the no HT group (ρ=-0.0814; P=0.756). There was no correlation between pMAPK signalling and the treatment-free interval in the HT group (ρ=-0.1560; P=0.330) or the initial-to-second period duration in the no HT group (ρ=-0.0116; P=0.965). Development of a second ER-positive cancer during or soon after completion of HT for the initial cancer may be associated with activation of the PI3K/Akt/mTOR pathway. Care should be taken during follow-up and when selecting adjuvant therapy for second cancer.
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Affiliation(s)
- Hirofumi Kanaizumi
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Chihiro Higashi
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Yumiko Tanaka
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Mika Hamada
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Wataru Shinzaki
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Tatsuya Azumi
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Yukihiko Hashimoto
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Hiroki Inui
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Toshiya Houjou
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
| | - Yoshifumi Komoike
- Division of Breast and Endocrine Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osakasayama, Osaka 589-8511, Japan
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19
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Abstract
The red-eared slider turtle (Trachemys scripta elegans), has developed remarkable adaptive mechanisms for coping with decreased oxygen availability during winter when lakes and ponds become covered with ice. Strategies for enduring anoxia tolerance include an increase in fermentable fuel reserves to support anaerobic glycolysis, the buffering of end products to minimize acidosis, altered expression in crucial survival genes, and strong metabolic rate suppression to minimize ATP-expensive metabolic processes such as protein synthesis. The mammalian target of rapamycin (mTOR) is at the center of the insulin-signaling pathway that regulates protein translation. The present study analyzed the responses of the mTOR signaling pathway to 5 (5H) or 20 h (20H) of anoxic submergence in liver and skeletal muscle of T. scripta elegans with a particular focus on regulatory changes in the phosphorylation states of targets. The data showed that phosphorylation of multiple mTOR targets was suppressed in skeletal muscle, but activated in the liver. Phosphorylated mTORSer2448 showed no change in skeletal muscle but had increased by approximately 4.5-fold in the liver after 20H of anoxia. The phosphorylation states of upstream positive regulators of mTOR (p-PDK-1Ser241, p-AKTSer473, and protein levels of GβL), the relative levels of dephosphorylated active PTEN, as well as phosphorylation state of negative regulators (TSC2Thr1462, p-PRAS40Thr246) were generally found to be differentially regulated in skeletal muscle and in liver. Downstream targets of mTOR (p-p70 S6KThr389, p-S6Ser235, PABP, p-4E-BP1Thr37/46, and p-eIF4ESer209) were generally unchanged in skeletal muscle but upregulated in most targets in liver. These findings indicate that protein synthesis is enhanced in the liver and suggests an increase in the synthesis of crucial proteins required for anoxic survival.
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Affiliation(s)
- Kama E Szereszewski
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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Li R, Wang Z, Liu S, Wu B, Zeng D, Zhang Y, Gong L, Deng F, Zheng H, Wang Y, Chen C, Chen J, Jiang B. Two novel STK11 missense mutations induce phosphorylation of S6K and promote cell proliferation in Peutz-Jeghers syndrome. Oncol Lett 2017; 15:717-726. [PMID: 29399144 DOI: 10.3892/ol.2017.7436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 01/19/2017] [Indexed: 01/23/2023] Open
Abstract
Peutz-Jeghers syndrome (PJS) is a rare hereditary disease caused by mutations in serine threonine kinase 11 (STK11) and characterized by an increased risk of developing cancer. Inactivation of STK11 has been associated with the mammalian target of rapamycin (mTOR) pathway. Hyperactivation and phosphorylation of the key downstream target genes ribosomal protein S6 kinase 1 (S6K1) and S6 promote protein synthesis and cell proliferation. To better understand the effects of STK11 dysfunction in the pathogenesis of PJS, genomic DNA samples from 21 patients with PJS from 11 unrelated families were investigated for STK11 mutations in the present study. The results revealed 6 point mutations and 2 large deletions in 8 (72.7%, 8/11) of the unrelated families. Notably, 3 novel mutations were identified, which included 2 missense mutations [c.88G>A (p.Asp30Asn) and c.869T>C (p.Leu290Pro)]. Subsequent immunohistochemical analysis revealed staining for phosphorylated-S6 protein in colonic hamartoma and breast benign tumor tissues from patients with PJS carrying the two respective missense mutations. Additionally, the novel missense STK11 mutants induced phosphorylation of S6K1 and S6, determined using western blot analysis, and promoted the proliferation of HeLa and SW1116 cells, determined using Cell Counting Kit-8 and colony formation assays. Collectively, these findings extend the STK11 mutation spectrum and confirm the pathogenicity of two novel missense mutations. This study represents a valuable insight into the molecular mechanisms implicated in the pathogenesis of PJS.
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Affiliation(s)
- Ran Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Zhiqing Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Shu Liu
- Medical Genetics Center, Guangdong Women and Children's Hospital, Guangzhou, Guangdong 510010, P.R. China
| | - Baoping Wu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Di Zeng
- Department of Gastroenterology, Guangzhou Panyu Central Hospital, Guangzhou, Guangdong 511400, P.R. China
| | - Yali Zhang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Lanbo Gong
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Feihong Deng
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Haoxuan Zheng
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Yadong Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Chudi Chen
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Junsheng Chen
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Bo Jiang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Gastroenterology, Beijing Tsinghua Changgung Hospital, Beijing 102218, P.R. China
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de Vicente JC, Peña I, Rodrigo JP, Rodríguez-Santamarta T, Lequerica-Fernández P, Suárez-Fernández L, Allonca E, García-Pedrero JM. Phosphorylated ribosomal protein S6 correlation with p21 expression and inverse association with tumor size in oral squamous cell carcinoma. Head Neck 2017; 39:1876-1887. [PMID: 28675642 DOI: 10.1002/hed.24854] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 03/01/2017] [Accepted: 05/01/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate the clinical relevance of phosphorylated ribosomal protein S6 (p-S6), a surrogate marker of mammalian target of rapamycin (mTOR) activation, and p21 in a series of 125 patients with oral squamous cell carcinomas (OSCCs). METHODS Immunohistochemical analysis was performed to ascertain the phosphorylation status of p-S6 at Ser235/236 and Ser240/244, p21, and p53 protein expression. RESULTS Expression of phosphorylated S6 protein on either serine 235/236 or serine 240/244 was detected in 83% and 88% tumors, respectively, and both of them were inversely and significantly correlated with the tumor size and local infiltration. Positive p21 expression was found in 91.5% of the cases, and was inversely correlated with tumor size. In OSCC, p21 expression correlates with p-S6 levels, a surrogate marker of mTOR activation, independently of p53 status. CONCLUSION Expression of both p21 and p-S6 was found to inversely associate with tumor size but not survival outcomes in patients with OSCC.
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Affiliation(s)
- Juan C de Vicente
- Department of Oral and Maxillofacial Surgery, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain.,Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Hospital Universitario Central de Asturias, Oviedo, Asturias, CIBERONC ISCIII Spain
| | - Ignacio Peña
- Department of Oral and Maxillofacial Surgery, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain
| | - Juan P Rodrigo
- Department of Otolaryngology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain.,Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Hospital Universitario Central de Asturias, Oviedo, Asturias, CIBERONC ISCIII Spain
| | - Tania Rodríguez-Santamarta
- Department of Oral and Maxillofacial Surgery, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain
| | | | - Laura Suárez-Fernández
- Department of Otolaryngology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain
| | - Eva Allonca
- Department of Otolaryngology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain
| | - Juana M García-Pedrero
- Department of Otolaryngology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain.,Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Hospital Universitario Central de Asturias, Oviedo, Asturias, CIBERONC ISCIII Spain
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22
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Diamanti S, Nikitakis N, Rassidakis G, Doulis I, Sklavounou A. Immunohistochemical evaluation of the mTOR pathway in intra-oral minor salivary gland neoplasms. Oral Dis 2016; 22:620-9. [PMID: 27177463 DOI: 10.1111/odi.12504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 04/16/2016] [Accepted: 05/04/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the expression of upstream and downstream molecules of the oncogenic mTOR signaling pathway in intra-oral minor salivary gland tumors (SGTs). MATERIALS AND METHODS Tissue samples consisted of 39 malignant and 13 benign minor SGTs, and 8 controls of normal minor salivary glands (NMSG). An immunohistochemical analysis for phosphorylated Akt, 4EBP1 and S6 (total and phosphorylated), and eIF4E was performed. RESULTS Expression of pAkt and 4EBP1 was observed in all SGTs and in most NMSG. p4EBP1 was detected in almost all SGT cases, NMSG being negative. S6 immunoreactivity was observed in 37.5% of NMSG, 92.3% of benign and 100% of malignant SGTs, while pS6 expression was observed in 77% of benign and 95% of malignant SGTs, but not in NMSG. Finally, eIF4E was expressed in 12.5% of NMSG, 69.2% of benign, and 76.9% of malignant tumors. All molecules studied had statistically significantly lower expression in NMSG compared with SGTs. Moreover, malignant neoplasms received higher scores compared with benign tumors for all molecules with the exception of eIF4E. CONCLUSION The mTOR signaling pathway is activated in SGTs, especially in malignancies. Therefore, the possible therapeutic role of targeting the mTOR pathway by rapamycin analogs in SGTs needs further investigation.
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Affiliation(s)
- S Diamanti
- Department of Oral Medicine and Pathology, Dental School, University of Athens, Athens, Greece. , .,Oral Medicine Department, 251 General Air Force and VA Hospital, Athens, Greece. ,
| | - N Nikitakis
- Department of Oral Medicine and Pathology, Dental School, University of Athens, Athens, Greece
| | - G Rassidakis
- Department of Pathology, Medical School, University of Athens, Athens, Greece.,Department of Pathology and Cytology, Carolinska University Hospital and Karolinska Institute, Solna, Sweden
| | - I Doulis
- Oral Medicine Department, 251 General Air Force and VA Hospital, Athens, Greece
| | - A Sklavounou
- Department of Oral Medicine and Pathology, Dental School, University of Athens, Athens, Greece
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23
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Abstract
Here we report that focal adhesion kinase (FAK) is required for optimal signalling to the Akt-p70S6K-S6 pathway in squamous cell carcinoma (SCC) cells. Specifically, in SCCs that are genetically deficient for FAK, there is reduced phosphorylation of Akt, p70S6K and S6, and signalling to Akt-p70S6K-S6 is more sensitive to inhibition by multiple agents that suppress the pathway. By contrast, mTOR is unaffected. Indeed, pharmacological agents that inhibit the Akt-p70S6K-S6 pathway, and PDK1 that lies upstream of Akt, also impair the autophagic targeting of activated c-Src (p-Src) in FAK deficient cells. This is associated with loss of a complex between p-Src and the autophagy protein LC3, a biochemical surrogate of impaired Src-selective autophagy. In keeping with a vital role for p70S6K, inhibition by a selective inhibitor and specific siRNA also impaired Src-selective autophagy. Finally, components of the PDK1-Akt-p70S6K signalling pathway were co-located with p-Src at autophagosomes, and Src and p70S6K co-exist in the same biochemical complex. We therefore deduce that the FAK-regulated signalling module PDK1-Akt-p70S6K that controls Src's intracellular trafficking operates at Src-containing autophagosomes.
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Affiliation(s)
- Emma Sandilands
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XR, United Kingdom
| | - Christina Schoenherr
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XR, United Kingdom
| | - Margaret C Frame
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XR, United Kingdom.
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24
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Ni Y, Wang L, Zhang J, Pang Z, Liu Q, Du J. PKD1 is downregulated in non-small cell lung cancer and mediates the feedback inhibition of mTORC1- S6K1 axis in response to phorbol ester. Int J Biochem Cell Biol 2015; 60:34-42. [PMID: 25578563 DOI: 10.1016/j.biocel.2014.12.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 11/05/2014] [Accepted: 12/25/2014] [Indexed: 12/27/2022]
Abstract
Protein kinase D1 (PKD1) is increasingly implicated in multiple biological and molecular events that regulate the proliferation or invasiveness in several cancers. However, little is known about the expression and functions of PKD1 in non-small cell lung cancer (NSCLC). In the present study, 34 pairs of human NSCLC and matched normal bronchiolar epitheliums were enrolled and evaluated for PKD1 expression by quantitative real-time PCR. We showed that PKD1 was downregulated in 26 of 34 cancer tissues in comparison with matched normal epitheliums. Moreover, patients with venous invasion or lymph node metastasis showed significant lower expression of PKD1. Exposure of NSCLC A549 and H520 cells to the PKD family inhibitor kb NB 142-70(Kb), at concentrations that inhibited PKD1 activation, strikingly potentiated S6K1 phosphorylation at Thr(389) and S6 phosphorylation at Ser(235/236) in response to phorbol ester (PMA). Knockdown of PKD1 with siRNAs strikingly enhanced S6K1 phosphorylation whereas constitutively active PKD1 resulted in the S6K1 activity inhibition. Furthermore, the PI3K inhibitors LY294002, BKM120 and MEK inhibitors U0126, PD0325901 blocked the enhanced S6K1 activity induced by Kb. Collectively, our results identify decreased expression of the PKD1 as a marker for NSCLC and the loss of PKD1 expression increases the malignant potential of NSCLC cells. This may be due to the function of PKD1 as a negative regulator of mTORC1-S6K1. Our results suggest that re-expression or activation of PKD1 might serve as a potential therapeutic target for NSCLC treatment.
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25
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Rozas NS, Redell JB, Hill JL, McKenna J, Moore AN, Gambello MJ, Dash PK. Genetic activation of mTORC1 signaling worsens neurocognitive outcome after traumatic brain injury. J Neurotrauma 2014; 32:149-58. [PMID: 25025304 DOI: 10.1089/neu.2014.3469] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Although the mechanisms that contribute to the development of traumatic brain injury (TBI)-related deficits are not fully understood, it has been proposed that altered energy utilization may be a contributing factor. The tuberous sclerosis complex, a heterodimer composed of hamartin/Tsc-1 and tuberin/Tsc-2, is a critical regulatory node that integrates nutritional and growth signals to govern energy using processes by regulating the activity of mechanistic Target of Rapamycin complex 1 (mTORC1). mTORC1 activation results in enhanced protein synthesis, an energy consuming process. We show that mice that have a heterozygous deletion of Tsc2 exhibit elevated basal mTORC1 activity in the cortex and the hippocampus while still exhibiting normal motor and neurocognitive functions. In addition, a mild closed head injury (mCHI) that did not activate mTORC1 in wild-type mice resulted in a further increase in mTORC1 activity in Tsc2(+/KO) mice above the level of activity observed in uninjured Tsc2(+/KO) mice. This enhanced level of increased mTORC1 activity was associated with worsened cognitive function as assessed using the Morris water maze and context discrimination tasks. These results suggest that there is a threshold of increased mTORC1 activity after a TBI that is detrimental to neurobehavioral performance, and interventions to inhibit excessive mTORC1 activation may be beneficial to neurocognitive outcome.
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Affiliation(s)
- Natalia S Rozas
- 1 Department of Neurobiology and Anatomy, the University of Texas Medical School , Houston, Texas
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26
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Penumatsa K, Abualkhair S, Wei L, Warburton R, Preston I, Hill NS, Watts SW, Fanburg BL, Toksoz D. Tissue transglutaminase promotes serotonin-induced AKT signaling and mitogenesis in pulmonary vascular smooth muscle cells. Cell Signal 2014; 26:2818-25. [PMID: 25218191 DOI: 10.1016/j.cellsig.2014.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 09/02/2014] [Indexed: 01/06/2023]
Abstract
Tissue transglutaminase 2 (TG2) is a multifunctional enzyme that cross-links proteins with monoamines such as serotonin (5-hydroxytryptamine, 5-HT) via a transglutamidation reaction, and is associated with pathophysiologic vascular responses. 5-HT is a mitogen for pulmonary artery smooth muscle cells (PASMCs) that has been linked to pulmonary vascular remodeling underlying pulmonary hypertension development. We previously reported that 5-HT-induced PASMC proliferation is inhibited by the TG2 inhibitor monodansylcadaverine (MDC); however, the mechanisms are poorly understood. In the present study we hypothesized that TG2 contributes to 5-HT-induced signaling pathways of PASMCs. Pre-treatment of bovine distal PASMCs with varying concentrations of the inhibitor MDC led to differential inhibition of 5-HT-stimulated AKT and ROCK activation, while p-P38 was unaffected. Concentration response studies showed significant inhibition of AKT activation at 50 μM MDC, along with inhibition of the AKT downstream targets mTOR, p-S6 kinase and p-S6. Furthermore, TG2 depletion by siRNA led to reduced 5-HT-induced AKT activation. Immunoprecipitation studies showed that 5-HT treatment led to increased levels of serotonylated AKT and increased TG2-AKT complex formations which were inhibited by MDC. Overexpression of TG2 point mutant cDNAs in PASMCs showed that the TG2 C277V transamidation mutant blunted 5-HT-induced AKT activation and 5-HT-induced PASMC mitogenesis. Finally, 5-HT-induced AKT activation was blunted in SERT genetic knock-out rat cells, but not in their wild-type counterpart. The SERT inhibitor imipramine similarly blocked AKT activation. These results indicate that TG2 contributes to 5-HT-induced distal PASMC proliferation via promotion of AKT signaling, likely via its serotonylation. Taken together, these results provide new insight into how TG2 may participate in vascular smooth muscle remodeling.
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27
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Khotskaya YB, Goverdhan A, Shen J, Ponz-Sarvise M, Chang SS, Hsu MC, Wei Y, Xia W, Yu D, Hung MC. S6K1 promotes invasiveness of breast cancer cells in a model of metastasis of triple-negative breast cancer. Am J Transl Res 2014; 6:361-376. [PMID: 25075253 PMCID: PMC4113498] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 05/15/2014] [Indexed: 06/03/2023]
Abstract
Breast cancer is the second-leading cause of oncology-related death in US women. Of all invasive breast cancers, patients with tumors lacking expression of the estrogen and progesterone hormone receptors and overexpression of human epidermal growth factor receptor 2 have the poorest clinical prognosis. These referred to as triple-negative breast cancer (TNBC) represent an aggressive form of disease that is marked by early-onset metastasis, high tumor recurrence rate, and low overall survival during the first three years post-diagnosis. In this report, we discuss a novel model of early-onset TNBC metastasis to bone and lungs, derived from MDA-MB-231 cells. Breast cancer cells injected intravenously produced rapid, osteolytic metastases in long bones and spines of athymic nude mice, with concurrent metastasis to lungs, liver, and soft tissues. From the bone metastases, we developed a highly metastatic luciferase-tagged cell line variant named MDA-231-LUC Met. In this report, we demonstrate that the Akt/mTOR/S6K1 axis is hyperactivated in these cells, leading to a dramatic increase in phosphorylation of S6 ribosomal protein at Ser235/236. Lastly, we provide evidence that inhibition of the furthest downstream kinase in the mTOR pathway, S6K1, with a highly specific inhibitor PF-4708671 inhibits cell migration, and thus may provide a potent anti-metastatic adjuvant therapy approach.
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Affiliation(s)
- Yekaterina B Khotskaya
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
| | - Aarthi Goverdhan
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
- The University of Texas Graduate School of Biomedical Sciences at HoustonHouston, Texas
| | - Jia Shen
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
- The University of Texas Graduate School of Biomedical Sciences at HoustonHouston, Texas
| | - Mariano Ponz-Sarvise
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
| | - Shih-Shin Chang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
- The University of Texas Graduate School of Biomedical Sciences at HoustonHouston, Texas
| | - Ming-Chuan Hsu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
| | - Yongkun Wei
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
| | - Weiya Xia
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
| | - Dihua Yu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
- The University of Texas Graduate School of Biomedical Sciences at HoustonHouston, Texas
| | - Mien-Chie Hung
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas
- The University of Texas Graduate School of Biomedical Sciences at HoustonHouston, Texas
- Center for Molecular Medicine and Graduate Institute of Cancer Biology, China Medical UniversityTaichung 402, Taiwan
- Department of Biotechnology, Asia UniversityTaichung, Taiwan
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28
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Puglisi M, Thavasu P, Stewart A, de Bono JS, O'Brien MER, Popat S, Bhosle J, Banerji U. AKT inhibition synergistically enhances growth-inhibitory effects of gefitinib and increases apoptosis in non-small cell lung cancer cell lines. Lung Cancer 2014; 85:141-6. [PMID: 24957682 DOI: 10.1016/j.lungcan.2014.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/07/2014] [Accepted: 05/08/2014] [Indexed: 01/13/2023]
Abstract
OBJECTIVES EGFR inhibitors are ineffective against most EGFR wild-type non-small cell lung cancer, for which novel treatment strategies are needed. AKT signalling is essential for mediating EGFR survival signals in NSCLC. We evaluated the combination of gefitinib and two different AKT inhibitors, the allosteric inhibitor AKTi-1/2 and the ATP-competitive pan-AKT inhibitor AZD5363, in EGFR-mutant (HCC-827 and PC-9) and -wild-type (NCI-H522, NCI-H1651), non-small cell lung cancer cell lines. MATERIALS AND METHODS Drug interaction was studied in two EGFR mutant and two EGFR wild-type non-small cell lung cancer cell lines by calculating combination index (CI) using median effect analysis. The effects on p-EGFR, p-ERK, p-AKT, p-S6 and apoptosis were studied by Western blot analysis. RESULTS The combination of gefitinib and AKTi-1/2 or AZD5363 showed synergistic growth inhibition in all cell lines. CI values for the combination of gefitinib and AKTi-1/2 were 0.35 (p=0.0048), 0.56 (p=0.036), 0.75 (p=0.13) and 0.64 (p=0.0003) in NCI-H522, NCI-H1651, HCC-827 and PC-9 cell lines, respectively; CI values of 0.45 (p=0.0087) and 0.22 (p<0.0001) were observed in NCI-H522 and PC-9 cells, respectively, when gefitinib was combined with AZD5363. Additive inhibition of signalling output through AKT and key downstream proteins (S6) and increased apoptosis were demonstrated. CONCLUSION Dual inhibition of EGFR and AKT may be a useful up-front strategy for patients with EGFR-mutant and -wild-type non-small cell lung cancer.
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Affiliation(s)
- M Puglisi
- The Drug Development Unit, Divisions of Cancer Therapeutics & Clinical Studies, The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK; The Lung Unit, The Royal Marsden NHS Foundation Trust, London, UK
| | - P Thavasu
- The Drug Development Unit, Divisions of Cancer Therapeutics & Clinical Studies, The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK
| | - A Stewart
- The Drug Development Unit, Divisions of Cancer Therapeutics & Clinical Studies, The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK
| | - J S de Bono
- The Drug Development Unit, Divisions of Cancer Therapeutics & Clinical Studies, The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK
| | - M E R O'Brien
- The Lung Unit, The Royal Marsden NHS Foundation Trust, London, UK
| | - S Popat
- The Lung Unit, The Royal Marsden NHS Foundation Trust, London, UK
| | - J Bhosle
- The Lung Unit, The Royal Marsden NHS Foundation Trust, London, UK
| | - U Banerji
- The Drug Development Unit, Divisions of Cancer Therapeutics & Clinical Studies, The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK.
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Kjell J, Codeluppi S, Josephson A, Abrams MB. Spatial and cellular characterization of mTORC1 activation after spinal cord injury reveals biphasic increase mainly attributed to microglia/macrophages. Brain Pathol 2014; 24:557-67. [PMID: 24576152 PMCID: PMC4347463 DOI: 10.1111/bpa.12135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/17/2014] [Indexed: 01/07/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is an intracellular kinase complex that regulates energy homeostasis and transcription. Modulation of mTORC1 has proven beneficial in experimental spinal cord injury, making this molecular target a candidate for therapeutic intervention in spinal cord injury. However, both inactivation and activation of mTORC1 have been reported beneficial for recovery. To obtain a more complete picture of mTORC1 activity, we aimed to characterize the spatiotemporal activation pattern of mTORC1 and identify activation in particular cell types after contusion spinal cord injury in rats. To be able to provide a spatial characterization of mTORC1 activation, we monitored activation of downstream target S6. We found robust mTORC1 activation both at the site of injury and in spinal segments rostral and caudal to the injury. There was constitutive mTORC1 activation in neurons that was biphasically reduced caudally after injury. We found biphasic mTORC1 activation in glial cells, primarily activated microglia/macrophages. Furthermore, we found mTORC1 activation in proliferating cells, suggesting this may be a function affected by mTORC1 modulation. Our results reveal potential windows of opportunity for therapeutic interference with mTORC1 signaling and immune cells as targets for inhibition of mTORC1 in spinal cord injury.
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Affiliation(s)
- Jacob Kjell
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Silver L, Michael JV, Goldfinger LE, Gallo G. Activation of PI3K and R-Ras signaling promotes the extension of sensory axons on inhibitory chondroitin sulfate proteoglycans. Dev Neurobiol 2014; 74:918-33. [PMID: 24578264 DOI: 10.1002/dneu.22174] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/24/2014] [Indexed: 12/22/2022]
Abstract
Chondroitin sulfate proteoglycans (CSPGs) are extracellular inhibitors of axon extension and plasticity, and cause growth cones to exhibit dystrophic behaviors. Phosphoinositide 3-kinase (PI3K) is a lipid kinase activated by axon growth promoting signals. In this study, we used embryonic chicken dorsal root ganglion neurons to determine if CSPGs impair signaling through PI3K. We report that CSPGs inhibit PI3K signaling in axons and growth cones, as evidenced by decreased levels of phosphorylated downstream kinases (Akt and S6). Direct activation of PI3K signaling, using a cell permeable phosphopeptide (PI3Kpep), countered the effects of CSPGs on growth cones and axon extension. Both overnight and acute treatment with PI3Kpep promoted axon extension on CSPG-coated substrates. The R-Ras GTPase is an upstream positive regulator of PI3K signaling. Expression of constitutively active R-Ras promoted axon extension and growth cone elaboration on CSPGs and permissive substrata. In contrast, an N-terminus-deleted constitutively active R-Ras, deficient in PI3K activation, promoted axon extension but not growth cone elaboration on CSPGs and permissive substrata. These data indicate that activation of R-Ras-PI3K signaling may be a viable approach for manipulating axon extension on CSPGs.
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Affiliation(s)
- Lee Silver
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, Pennsylvania, 19140; Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, 19140
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Xie L, Antonow-Schlorke I, Schwab M, McDonald TJ, Nathanielsz PW, Li C. The frontal cortex IGF system is down regulated in the term, intrauterine growth restricted fetal baboon. Growth Horm IGF Res 2013; 23:187-192. [PMID: 23911858 PMCID: PMC3919499 DOI: 10.1016/j.ghir.2013.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [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: 05/03/2013] [Revised: 07/03/2013] [Accepted: 07/04/2013] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The IGF system exerts systemic and local actions during development. We previously demonstrated that fetal cerebral cortical IGF1 is reduced at 0.5 gestation in our IUGR baboon nonhuman primate model. We hypothesized that by term protein expression of several key IGF system stimulatory peptide pathway components and downstream nutrient signaling effectors of IGF, mammalian target of rapamycin (mTOR) and S6, would decrease, indicating reduced cellular nutrient uptake and protein synthesis. DESIGN We fed 7 control baboons ad libitum while 6 baboons ate a globally reduced diet (70% of feed eaten by controls) from 0.16 gestation through pregnancy that produces IUGR. Fetuses were removed at Cesarean section at 0.9 gestation. Frontal cortex sections were stained for IGFI, IGFII, IGFRI, IGFR2, IGFBP2, 3, 5 and 6, and mTOR and ribosomal protein S6 and double stained with NeuN a neuron-specific nuclear antigen. RESULTS All proteins stained neuronal cytoplasm except IGFRI which showed only glial cell cytoplasmic and blood vessel staining. IUGR fetuses showed decreased frontal cortical immunoreactive IGFI, IGFII, IGFRI, IGFBP2, 5 and 6, and mTOR and S6 (p < 0.05). IGFBP3 increased (p < 0.05) and IGFR2 was unchanged (p > 0.05). There were no differences between male and female fetal brains. CONCLUSIONS When fetal nutrient availability is decreased, IUGR down regulates the IGF system and its mTOR signaling pathway in the fetal frontal cortex coincident with slowed growth. These findings emphasize the importance of the local tissue IGF system in fetal primate brain development.
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Affiliation(s)
- L Xie
- The University of Texas Health Science Center San Antonio, Center for Pregnancy and Newborn Research, Dept. OB/GYN, San Antonio, TX 78229, USA
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Yasumizu Y, Miyajima A, Kosaka T, Miyazaki Y, Kikuchi E, Oya M. Dual PI3K/mTOR inhibitor NVP-BEZ235 sensitizes docetaxel in castration resistant prostate cancer. J Urol 2013; 191:227-34. [PMID: 23954373 DOI: 10.1016/j.juro.2013.07.101] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2013] [Indexed: 12/21/2022]
Abstract
PURPOSE Effective therapeutic strategies that can achieve long-term improvement in patients with castration resistant prostate cancer are urgently needed. We recently reported that the activated PI3K/Akt/mTOR signaling pathway induced by docetaxel explains resistance to docetaxel in castration resistant prostate cancer. In this study we explored the efficacy of NVP-BEZ235, a dual PI3K and mTORC1/2 inhibitor, for docetaxel resistant castration resistant prostate cancer. MATERIALS AND METHODS We used the 2 human castration resistant prostate cancer cell lines C4-2 and C4-2AT6. At our laboratory C4-2AT6 cells were established from C4-2 under androgen ablated treatment for 6 months. We investigated the efficacy of NVP-BEZ235 monotherapy and NVP-BEZ235 combined with docetaxel in vitro and in vivo. RESULTS Increased phosphorylated Akt in C4-2AT6 cells was significantly inhibited by NVP-BEZ235 in a dose and time dependent manner. WST cell proliferation assay results in C4-2AT6 cells revealed that combined administration of NVP-BEZ235 and docetaxel had significant, synergistically greater cytotoxicity than NVP-BEZ235 or docetaxel monotherapy. Combined NVP-BEZ235 (40 mg/kg) and docetaxel (4 mg/kg) in vivo in a castrated mouse xenograft model inhibited C4-2AT6 tumor growth to a greater degree than in the monotherapy groups. Also, NVP-BEZ235 showed significant efficacy with docetaxel at a low concentration in vivo, suggesting that NVP-BEZ235 effectively decreased resistance to docetaxel. CONCLUSIONS Results suggest that inhibition of the PI3K/Akt/mTOR signaling pathway by NVP-BEZ235 can overcome docetaxel resistance in human castration resistant prostate cancer. Our findings provide a molecular basis for the clinical use of combined administration of NVP-BEZ235 and docetaxel in patients with castration resistant prostate cancer.
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Affiliation(s)
- Yota Yasumizu
- Department of Urology, Keio University School of Medicine, Tokyo, Japan
| | - Akira Miyajima
- Department of Urology, Keio University School of Medicine, Tokyo, Japan.
| | - Takeo Kosaka
- Department of Urology, Keio University School of Medicine, Tokyo, Japan
| | - Yasumasa Miyazaki
- Department of Urology, Keio University School of Medicine, Tokyo, Japan
| | - Eiji Kikuchi
- Department of Urology, Keio University School of Medicine, Tokyo, Japan
| | - Mototsugu Oya
- Department of Urology, Keio University School of Medicine, Tokyo, Japan
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Kim SH, Yu HS, Park HG, Ha K, Kim YS, Shin SY, Ahn YM. Intracerebroventricular administration of ouabain, a Na/K-ATPase inhibitor, activates mTOR signal pathways and protein translation in the rat frontal cortex. Prog Neuropsychopharmacol Biol Psychiatry 2013; 45:73-82. [PMID: 23643758 DOI: 10.1016/j.pnpbp.2013.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/02/2013] [Accepted: 04/21/2013] [Indexed: 11/16/2022]
Abstract
Intracerebroventricular (ICV) injection of ouabain, a specific Na/K-ATPase inhibitor, induces behavioral changes in rats in a putative animal model of mania. The binding of ouabain to Na/K-ATPase affects signaling molecules in vitro, including ERK1/2 and Akt, which promote protein translation. We have also reported that ERK1/2 and Akt in the brain are involved in the ouabain-induced hyperactivity of rats. In this study, rats were given an ICV injection of ouabain, and then their frontal cortices were examined to determine the effects of ouabain on the mTOR/p70S6K/S6 signaling pathway and protein translation, which are important in modifications of neural circuits and behavior. Rats showed ouabain-induced hyperactivity up to 8h following injection, and increased phosphorylation levels of mTOR, p70S6K, S6, eIF4B, and 4E-BP at 1, 2, 4, and 8h following ouabain injection. Immunohistochemical analyses revealed that increased p-S6 immunoreactivity in the cytoplasm of neurons by ouabain was evident in the prefrontal, cingulate, and orbital cortex. These findings suggested increased translation initiation in response to ouabain. The rate of protein synthesis was measured as the amount of [(3)H]-leucine incorporation in the cell-free extracts of frontal cortical tissues, and showed a significant increase at 8h after ouabain injection. These results suggest that ICV injection of ouabain induced activation of the protein translation initiation pathway regulated by ERK1/2 and Akt, and prolonged hyperactivity in rats. In conclusion, protein translation pathway could play an important role in ouabain-induced hyperactivity in a rodent model of mania.
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Affiliation(s)
- Se Hyun Kim
- Department of Psychiatry and Behavioral Science & Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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Du W, Hálová L, Kirkham S, Atkin J, Petersen J. TORC2 and the AGC kinase Gad8 regulate phosphorylation of the ribosomal protein S6 in fission yeast. Biol Open 2012; 1:884-8. [PMID: 23213482 PMCID: PMC3507231 DOI: 10.1242/bio.20122022] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 06/13/2012] [Indexed: 11/20/2022] Open
Abstract
TOR (Target Of Rapamycin) signalling coordinates cell growth and division in response to changes in the nutritional environment of the cell. TOR kinases form two distinct complexes: TORC1 and TORC2. In mammals, the TORC1 controlled S6K1 kinase phosphorylates the ribosomal protein S6 thereby co-ordinating cell size and nutritional status. We show that the Schizosaccharomyces pombe AGC kinase Gad8 co-immunoprecipitates with the ribosomal protein S6 (Rps6) and regulates its phosphorylation status. It has previously been shown that Gad8 is phosphorylated by TORC2. Consistent with this, we find that TORC2 as well as TORC1 modulates Rps6 phosphorylation. Therefore, S6 phosphorylation in fission yeast actually represents a read-out of the combined activities of TORC1 and TORC2. In contrast, we find that the in vivo phosphorylation status of Maf1 (a repressor of RNA polymerase III) specifically correlates with TORC1 activity.
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Affiliation(s)
- Wei Du
- University of Manchester, C.4255 Michael Smith building, Faculty of Life Sciences , Oxford Road, Manchester M13 9PT , UK
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