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Su Y, Lin H, Yu J, Mao L, Jin W, Liu T, Jiang S, Wu Y, Zhang S, Geng Q, Ge C, Zhao F, Chen T, Cui Y, Li J, Hou H, Zhou X, Li H. RIT1 regulates mitosis and promotes proliferation by interacting with SMC3 and PDS5 in hepatocellular carcinoma. J Exp Clin Cancer Res 2023; 42:326. [PMID: 38017479 PMCID: PMC10685607 DOI: 10.1186/s13046-023-02892-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 11/10/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND As a small G protein of Ras family, Ras-like-without-CAAX-1 (RIT1) plays a critical role in various tumors. Our previous study has demonstrated the involvement of RIT1 in promoting malignant progression of hepatocellular carcinoma (HCC). However, its underlying mechanism remains unclear. METHODS Gene set enrichment analysis (GSEA) was conducted in the TCGA LIHC cohort to investigate the underlying biological mechanism of RIT1. Live cell imaging, immunofluorescence (IF) and flow cytometry assays were used to verify biological function of RIT1 in HCC mitosis. Subcutaneous xenografting of human HCC cells in BALB/c nude mice was utilized to assess tumor proliferation in vivo. RNA-seq, co-immunoprecipitation (Co-IP), mass spectrometry analyses, western blot and IF assays were employed to elucidate the mechanisms by which RIT1 regulates mitosis and promotes proliferation in HCC. RESULTS Our findings demonstrate that RIT1 plays a crucial role in regulating mitosis in HCC. Knockdown of RIT1 disrupts cell division, leading to G2/M phase arrest, mitotic catastrophe, and apoptosis in HCC cells. SMC3 is found to interact with RIT1 and knockdown of SMC3 attenuates the proliferative effects mediated by RIT1 both in vitro and in vivo. Mechanistically, RIT1 protects and maintains SMC3 acetylation by binding to SMC3 and PDS5 during mitosis, thereby promoting rapid cell division and proliferation in HCC. Notably, we have observed an upregulation of SMC3 expression in HCC tissues, which is associated with poor patient survival and promotion of HCC cell proliferation. Furthermore, there is a significant positive correlation between the expression levels of RIT1, SMC3, and PDS5. Importantly, HCC patients with high expression of both RIT1 and SMC3 exhibit worse prognosis compared to those with high RIT1 but low SMC3 expression. CONCLUSIONS Our findings underscore the crucial role of RIT1 in regulating mitosis in HCC and further demonstrate its potential as a promising therapeutic target for HCC treatment.
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Affiliation(s)
- Yang Su
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Hechun Lin
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Junming Yu
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Lin Mao
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Wenjiao Jin
- Department of Oncology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, China
| | - Tengfei Liu
- Department of Oncology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200127, China
| | - Shuqing Jiang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Yunyu Wu
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Saihua Zhang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Qin Geng
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Chao Ge
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Fangyu Zhao
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Taoyang Chen
- Qidong Liver Cancer Institute, Qidong, 226200, China
| | - Ying Cui
- Cancer Institute of Guangxi, Nanning, 530021, China
| | - Jinjun Li
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China
| | - Helei Hou
- Precision Medicine Center of Oncology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
| | - Xinli Zhou
- Department of Oncology, Huashan Hospital, Fudan University, Shanghai, 200040, China.
| | - Hong Li
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200032, China.
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Wu L, Wang F, Moncman CL, Pandey M, Clarke HA, Frazier HN, Young LE, Gentry MS, Cai W, Thibault O, Sun RC, Andres DA. RIT1 regulation of CNS lipids RIT1 deficiency Alters cerebral lipid metabolism and reduces white matter tract oligodendrocytes and conduction velocities. Heliyon 2023; 9:e20384. [PMID: 37780758 PMCID: PMC10539968 DOI: 10.1016/j.heliyon.2023.e20384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 07/21/2023] [Accepted: 09/20/2023] [Indexed: 10/03/2023] Open
Abstract
Oligodendrocytes (OLs) generate lipid-rich myelin membranes that wrap axons to enable efficient transmission of electrical impulses. Using a RIT1 knockout mouse model and in situ high-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) coupled with MS-based lipidomic analysis to determine the contribution of RIT1 to lipid homeostasis. Here, we report that RIT1 loss is associated with altered lipid levels in the central nervous system (CNS), including myelin-associated lipids within the corpus callosum (CC). Perturbed lipid metabolism was correlated with reduced numbers of OLs, but increased numbers of GFAP+ glia, in the CC, but not in grey matter. This was accompanied by reduced myelin protein expression and axonal conduction deficits. Behavioral analyses revealed significant changes in voluntary locomotor activity and anxiety-like behavior in RIT1KO mice. Together, these data reveal an unexpected role for RIT1 in the regulation of cerebral lipid metabolism, which coincide with altered white matter tract oligodendrocyte levels, reduced axonal conduction velocity, and behavioral abnormalities in the CNS.
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Affiliation(s)
- Lei Wu
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
| | - Fang Wang
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
| | - Carole L. Moncman
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
| | - Mritunjay Pandey
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
| | - Harrison A. Clarke
- Department of Neuroscience, College of Medicine, University of Kentucky, KY 40536, USA
| | - Hilaree N. Frazier
- Department of Pharmacological and Nutritional Sciences, College of Medicine, University of Kentucky, KY 40536, USA
| | - Lyndsay E.A. Young
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
- Markey Cancer Center, Lexington, KY 40536, USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
- Markey Cancer Center, Lexington, KY 40536, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32611, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida, College of Medicine, Gainesville, FL 32611, USA
| | - Weikang Cai
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, NY 11568, USA
| | - Olivier Thibault
- Department of Pharmacological and Nutritional Sciences, College of Medicine, University of Kentucky, KY 40536, USA
| | - Ramon C. Sun
- Department of Neuroscience, College of Medicine, University of Kentucky, KY 40536, USA
- Markey Cancer Center, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32611, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida, College of Medicine, Gainesville, FL 32611, USA
| | - Douglas A. Andres
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, KY 40536, USA
- Markey Cancer Center, Lexington, KY 40536, USA
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, KY 40536, USA
- Gill Heart and Vascular Institute, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
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3
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Alhamad S, Elmasry Y, Uwagboe I, Chekmeneva E, Sands C, Cooper BW, Camuzeaux S, Salam A, Parsons M. B7-H3 Associates with IMPDH2 and Regulates Cancer Cell Survival. Cancers (Basel) 2023; 15:3530. [PMID: 37444640 DOI: 10.3390/cancers15133530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Lung cancer is one of the most common cancers worldwide, and despite improvements in treatment regimens, patient prognosis remains poor. Lung adenocarcinomas develop from the lung epithelia and understanding how specific genetic and environmental factors lead to oncogenic transformation in these cells is of great importance to define the pathways that contribute to tumorigenesis. The recent rise in the use of immunotherapy to treat different cancers has prompted the exploration of immune modulators in tumour cells that may provide new targets to manipulate this process. Of these, the B7 family of cell surface receptors, which includes PD-1, is of particular interest due to its role in modulating immune cell responses within the tumour microenvironment. B7-H3 (CD276) is one family member that is upregulated in many cancer types and suggested to contribute to tumour-immune interactions. However, the function and ligand(s) for this receptor in normal lung epithelia and the mechanisms through which the overexpression of B7-H3 regulate cancer progression in the absence of immune cell interactions remain unclear. Here, we present evidence that B7-H3 is associated with one of the key rate-limiting metabolic enzymes IMPDH2, and the localisation of this complex is altered in human lung cancer cells that express high levels of B7-H3. Mechanistically, the IMPDH2:B7-H3 complex provides a protective role in cancer cells to escape oxidative stress triggered by chemotherapy, thus leading to cell survival. We further demonstrate that the loss of B7-H3 in cancer cells has no effect on growth or migration in 2D but promotes the expansion of 3D spheroids in an IMPDH2-dependent manner. These findings provide new insights into the B7-H3 function in the metabolic homeostasis of normal and transformed lung cancer cells, and whilst this molecule remains an interesting target for immunotherapy, these findings caution against the use of anti-B7-H3 therapies in certain clinical settings.
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Affiliation(s)
- Salwa Alhamad
- Randall Centre for Cell and Molecular Biophysics, King's College London, Guys Campus, New Hunts House, London SE1 1UL, UK
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Yassmin Elmasry
- Randall Centre for Cell and Molecular Biophysics, King's College London, Guys Campus, New Hunts House, London SE1 1UL, UK
| | - Isabel Uwagboe
- Randall Centre for Cell and Molecular Biophysics, King's College London, Guys Campus, New Hunts House, London SE1 1UL, UK
| | - Elena Chekmeneva
- National Phenome Centre, Section of Bioanalytical Chemistry, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital Campus, IRDB Building, 5th Floor, Du Cane Road, London W12 0NN, UK
| | - Caroline Sands
- National Phenome Centre, Section of Bioanalytical Chemistry, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital Campus, IRDB Building, 5th Floor, Du Cane Road, London W12 0NN, UK
| | - Benjamin W Cooper
- National Phenome Centre, Section of Bioanalytical Chemistry, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital Campus, IRDB Building, 5th Floor, Du Cane Road, London W12 0NN, UK
| | - Stephane Camuzeaux
- National Phenome Centre, Section of Bioanalytical Chemistry, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital Campus, IRDB Building, 5th Floor, Du Cane Road, London W12 0NN, UK
| | - Ash Salam
- National Phenome Centre, Section of Bioanalytical Chemistry, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital Campus, IRDB Building, 5th Floor, Du Cane Road, London W12 0NN, UK
| | - Maddy Parsons
- Randall Centre for Cell and Molecular Biophysics, King's College London, Guys Campus, New Hunts House, London SE1 1UL, UK
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4
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Stillage Waste from Strawberry Spirit Production as a Source of Bioactive Compounds with Antioxidant and Antiproliferative Potential. Antioxidants (Basel) 2023; 12:antiox12020421. [PMID: 36829982 PMCID: PMC9951990 DOI: 10.3390/antiox12020421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
The production of fruit distillates generates solid residues which are potentially rich in bioactive compounds worthy of valorization and exploitation. We report herein the in vitro antioxidant and antiproliferative properties of an extract obtained from the waste of fermented strawberry distillate production. The main low molecular weight phenolic components of the extract were identified as ellagic acid and p-coumaric acid using spectroscopic and chromatographic analysis. The extract exhibited high antioxidant properties, particularly in the ferric reducing/antioxidant power (FRAP) assay, and a high total phenolic content (TPC). It was also able to induce an antiproliferative effect on different human cancer cell lines. A strong decrease in viability in human promyelocytic leukemia (HL-60) cells through a rapid and massive apoptosis were observed. Moreover, at an early time (<30 min), reactive oxygen species (ROS) production and inactivation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway were detected. Notably, the antiproliferative activity of the sample was comparable to that observed with an analogous extract prepared from unfermented, fresh strawberries. These results bring new opportunities for the valorization of fruit distillery by-products as low-cost resources for the design of bioactive formulations of comparable value to that from fresh food.
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5
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Liu D, Han X, Zhang Z, Tse G, Shao Q, Liu T. Role of Heat Shock Proteins in Atrial Fibrillation: From Molecular Mechanisms to Diagnostic and Therapeutic Opportunities. Cells 2022; 12:cells12010151. [PMID: 36611952 PMCID: PMC9818491 DOI: 10.3390/cells12010151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Heat shock proteins (HSPs) are endogenous protective proteins and biomarkers of cell stress response, of which examples are HSP70, HSP60, HSP90, and small HSPs (HSPB). HSPs protect cells and organs, especially the cardiovascular system, against harmful and cytotoxic conditions. More recent attention has focused on the roles of HSPs in the irreversible remodeling of atrial fibrillation (AF), which is the most common arrhythmia in clinical practice and a significant contributor to mortality. In this review, we investigated the relationship between HSPs and atrial remodeling mechanisms in AF. PubMed was searched for studies using the terms "Heat Shock Proteins" and "Atrial Fibrillation" and their relevant abbreviations up to 10 July 2022. The results showed that HSPs have cytoprotective roles in atrial cardiomyocytes during AF by promoting reverse electrical and structural remodeling. Heat shock response (HSR) exhaustion, followed by low levels of HSPs, causes proteostasis derailment in cardiomyocytes, which is the basis of AF. Furthermore, potential implications of HSPs in the management of AF are discussed in detail. HSPs represent reliable biomarkers for predicting and staging AF. HSP inducers may serve as novel therapeutic modalities in postoperative AF. HSP induction, either by geranylgeranylacetone (GGA) or by other compounds presently in development, may therefore be an interesting new approach for upstream therapy for AF, a strategy that aims to prevent AF whilst minimizing the ventricular proarrhythmic risks of traditional anti-arrhythmic agents.
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Affiliation(s)
- Daiqi Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Xuyao Han
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Zhiwei Zhang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, Hong Kong, China
- Kent and Medway Medical School, Canterbury CT2 7NZ, UK
| | - Qingmiao Shao
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
- Correspondence: (Q.S.); or (T.L.)
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
- Correspondence: (Q.S.); or (T.L.)
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6
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Cuevas-Navarro A, Rodriguez-Muñoz L, Grego-Bessa J, Cheng A, Rauen KA, Urisman A, McCormick F, Jimenez G, Castel P. Cross-species analysis of LZTR1 loss-of-function mutants demonstrates dependency to RIT1 orthologs. eLife 2022; 11:e76495. [PMID: 35467524 PMCID: PMC9068208 DOI: 10.7554/elife.76495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/22/2022] [Indexed: 11/25/2022] Open
Abstract
RAS GTPases are highly conserved proteins involved in the regulation of mitogenic signaling. We have previously described a novel Cullin 3 RING E3 ubiquitin ligase complex formed by the substrate adaptor protein LZTR1 that binds, ubiquitinates, and promotes proteasomal degradation of the RAS GTPase RIT1. In addition, others have described that this complex is also responsible for the ubiquitination of classical RAS GTPases. Here, we have analyzed the phenotypes of Lztr1 loss-of-function mutants in both fruit flies and mice and have demonstrated a biochemical preference for their RIT1 orthologs. Moreover, we show that Lztr1 is haplosufficient in mice and that embryonic lethality of the homozygous null allele can be rescued by deletion of Rit1. Overall, our results indicate that, in model organisms, RIT1 orthologs are the preferred substrates of LZTR1.
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Affiliation(s)
- Antonio Cuevas-Navarro
- Helen Diller Family Comprehensive Cancer Center, University of California, San FranciscoSan FranciscoUnited States
| | - Laura Rodriguez-Muñoz
- Institute for Molecular Biology of Barcelona, Consejo Superior de Investigaciones CientíficasBarcelonaSpain
| | | | - Alice Cheng
- Helen Diller Family Comprehensive Cancer Center, University of California, San FranciscoSan FranciscoUnited States
| | - Katherine A Rauen
- UC Davis MIND Institute, University of California DavisSacramentoUnited States
- Department of Pediatrics, University of California DavisSacramentoUnited States
| | - Anatoly Urisman
- Department of Anatomic Pathology, University of California San FranciscoSan FranciscoUnited States
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San FranciscoSan FranciscoUnited States
| | - Gerardo Jimenez
- Institute for Molecular Biology of Barcelona, Consejo Superior de Investigaciones CientíficasBarcelonaSpain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)BarcelonaSpain
| | - Pau Castel
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of MedicineNew YorkUnited States
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Abstract
The RASopathies are a group of disorders caused by a germline mutation in one of the genes encoding a component of the RAS/MAPK pathway. These disorders, including neurofibromatosis type 1, Noonan syndrome, cardiofaciocutaneous syndrome, Costello syndrome and Legius syndrome, among others, have overlapping clinical features due to RAS/MAPK dysfunction. Although several of the RASopathies are very rare, collectively, these disorders are relatively common. In this Review, we discuss the pathogenesis of the RASopathy-associated genetic variants and the knowledge gained about RAS/MAPK signaling that resulted from studying RASopathies. We also describe the cell and animal models of the RASopathies and explore emerging RASopathy genes. Preclinical and clinical experiences with targeted agents as therapeutics for RASopathies are also discussed. Finally, we review how the recently developed drugs targeting RAS/MAPK-driven malignancies, such as inhibitors of RAS activation, direct RAS inhibitors and RAS/MAPK pathway inhibitors, might be leveraged for patients with RASopathies.
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Affiliation(s)
- Katie E Hebron
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Edjay Ralph Hernandez
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Marielle E Yohe
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
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8
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Elevated expression of RIT1 hyperactivates RAS/MAPK signal and sensitizes hepatocellular carcinoma to combined treatment with sorafenib and AKT inhibitor. Oncogene 2022; 41:732-744. [PMID: 34845378 DOI: 10.1038/s41388-021-02130-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 11/11/2021] [Accepted: 11/19/2021] [Indexed: 11/08/2022]
Abstract
Hyperactivation of RAS/MAPK signaling is commonly observed in hepatocellular carcinoma (HCC). Gain-of-function mutations of canonical RAS genes, however, are rarely detected and it remains unclear how the activity of this pathway is turned on during hepatocarcinogenesis. We performed a comprehensive analysis of RAS superfamily genetic alterations across ten subfamilies, 152 members in 377 HCC patients from the Cancer Genome Atlas database. RIT1 (Ras-like without CAAX 1) was the most frequently altered RAS member amplified in 13% of the HCC cohort. Both genomic amplification and CREB-mediated transcriptional activation contributed to the elevated RIT1 expression, and its overexpression correlated with RAS/MAPK activation and poor prognosis. Then, we found that RIT1-induced angiogenesis via the MEK/ERK/EIF4E/HIF1-α/VEGFA axis. MAP3K11 and MAP3K12, in addition to CRAF, could mediate this process by binding to RIT1. Moreover, RIT1 increased the phosphorylation of p38 MAPK and AKT to promote cell survival under reactive oxygen species stress. Based on this mechanistic understanding, we treated RIT1-overexpressing HCC with combined regimen sorafenib plus AKT inhibitor, and achieved enhanced antitumor effects in vivo. Our study reveals RAS "orphan" member RIT1 as the most common genetic alteration of RAS family in HCC and combination of sorafenib with AKT inhibitor might be a promising treatment strategy for RIT1-overexpressing HCC.
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Fagan RR, Kearney PJ, Luethi D, Bolden NC, Sitte HH, Emery P, Melikian HE. Dopaminergic Ric GTPase activity impacts amphetamine sensitivity and sleep quality in a dopamine transporter-dependent manner in Drosophila melanogaster. Mol Psychiatry 2021; 26:7793-7802. [PMID: 34471250 PMCID: PMC8881384 DOI: 10.1038/s41380-021-01275-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/28/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023]
Abstract
Dopamine (DA) is required for movement, sleep, and reward, and DA signaling is tightly controlled by the presynaptic DA transporter (DAT). Therapeutic and addictive psychostimulants, including methylphenidate (Ritalin; MPH), cocaine, and amphetamine (AMPH), markedly elevate extracellular DA via their actions as competitive DAT inhibitors (MPH, cocaine) and substrates (AMPH). DAT silencing in mice and invertebrates results in hyperactivity, reduced sleep, and blunted psychostimulant responses, highlighting DAT's essential role in DA-dependent behaviors. DAT surface expression is not static; rather it is dynamically regulated by endocytic trafficking. PKC-stimulated DAT endocytosis requires the neuronal GTPase, Rit2, and Rit2 silencing in mouse DA neurons impacts psychostimulant sensitivity. However, it is unknown whether or not Rit2-mediated changes in psychostimulant sensitivity are DAT-dependent. Here, we leveraged Drosophila melanogaster to test whether the Drosophila Rit2 ortholog, Ric, impacts dDAT function, trafficking, and DA-dependent behaviors. Orthologous to hDAT and Rit2, dDAT and Ric directly interact, and the constitutively active Ric mutant Q117L increased dDAT surface levels and function in cell lines and ex vivo Drosophila brains. Moreover, DAergic RicQ117L expression caused sleep fragmentation in a DAT-dependent manner but had no effect on total sleep and daily locomotor activity. Importantly, we found that Rit2 is required for AMPH-stimulated DAT internalization in mouse striatum, and that DAergic RicQ117L expression significantly increased Drosophila AMPH sensitivity in a DAT-dependent manner, suggesting a conserved impact of Ric-dependent DAT trafficking on AMPH sensitivity. These studies support that the DAT/Rit2 interaction impacts both baseline behaviors and AMPH sensitivity, potentially by regulating DAT trafficking.
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Affiliation(s)
- Rita R. Fagan
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, UMASS Medical School, Worcester, MA
| | - Patrick J. Kearney
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, UMASS Medical School, Worcester, MA
| | - Dino Luethi
- Medical University Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Vienna, Austria, A-1090
| | - Nicholas C. Bolden
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, UMASS Medical School, Worcester, MA
| | - Harald H. Sitte
- Medical University Vienna, Center for Physiology and Pharmacology, Institute of Pharmacology, Vienna, Austria, A-1090
| | - Patrick Emery
- Department of Neurobiology, UMASS Medical School, Worcester, MA
| | - Haley E. Melikian
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, UMASS Medical School, Worcester, MA,Address correspondence to: Haley Melikian, Ph.D., Department of Neurobiology, UMASS Medical School, LRB 726, 364 Plantation St., Worcester, MA 01605, 774-455-4308 (phone), 508-856-6266 (fax),
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10
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Zhang H, Cao X, Wang J, Li Q, Zhao Y, Jin X. LZTR1: A promising adaptor of the CUL3 family. Oncol Lett 2021; 22:564. [PMID: 34113392 PMCID: PMC8185703 DOI: 10.3892/ol.2021.12825] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/07/2021] [Indexed: 02/06/2023] Open
Abstract
The study of the disorders of ubiquitin-mediated proteasomal degradation may unravel the molecular basis of human diseases, such as cancer (prostate cancer, lung cancer and liver cancer, etc.) and nervous system disease (Parkinson's disease, Alzheimer's disease and Huntington's disease, etc.) and help in the design of new therapeutic methods. Leucine zipper-like transcription regulator 1 (LZTR1) is an important substrate recognition subunit of cullin-RING E3 ligase that plays an important role in the regulation of cellular functions. Mutations in LZTR1 and dysregulation of associated downstream signaling pathways contribute to the pathogenesis of Noonan syndrome (NS), glioblastoma and chronic myeloid leukemia. Understanding the molecular mechanism of the normal function of LZTR1 is thus critical for its eventual therapeutic targeting. In the present review, the structure and function of LZTR1 are described. Moreover, recent advances in the current knowledge of the functions of LZTR1 in NS, glioblastoma (GBM), chronic myeloid leukemia (CML) and schwannomatosis and the influence of LZTR1 mutations are also discussed, providing insight into how LZTR1 may be targeted for therapeutic purposes.
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Affiliation(s)
- Hui Zhang
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Xinyi Cao
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Jian Wang
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Qian Li
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Yiting Zhao
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Xiaofeng Jin
- Department of Biochemistry and Molecular Biology; Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, P.R. China
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11
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Sinclair AJ, Moalwi MH, Amoaten T. Is EBV Associated with Breast Cancer in Specific Geographic Locations? Cancers (Basel) 2021; 13:cancers13040819. [PMID: 33669217 PMCID: PMC7919813 DOI: 10.3390/cancers13040819] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/04/2021] [Accepted: 02/11/2021] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Epstein–Barr virus (EBV) is a virus that infects people and then remains within their bodies for life. Almost everyone is infected with EBV by the time they are an adult. EBV is called a cancer virus because it causes some cancers of blood cells and some cancers of the stomach and nose. Some scientists think that EBV may also cause some cases of breast cancer, but others disagree. It is difficult to be sure whether a pathogen that most people are infected with is the cause of any disease. Here, we review and discuss the evidence for and against the link between EBV and breast cancer and pose the questions that could help to answer whether EBV is a cause of breast cancer. Abstract Epstein–Barr virus (EBV) is a virus that establishes a life-long infection in people, and infection with EBV is nearly ubiquitous by adulthood. EBV was identified from biopsy material from a child with Burkitt’s lymphoma (BL) in sub-Saharan Africa. EBV has a well-characterised role in the development of some cancers, notably, Burkitt’s lymphoma (BL), Hodgkin’s disease (HD), gastric carcinoma (GC), and nasopharyngeal carcinoma (NPC). Links have also been made between EBV and breast cancer (BC), but these have been controversial. For all EBV-associated cancers, the ubiquitous nature of infection with EBV, contrasted with the relatively rare development of cancer, highlights a problem of determining whether EBV is an aetiological agent of cancer. In addition, the geographic distributions of some EBV-associated cancers point to contributions from additional co-factors. Recent meta-analyses of the incidence of EBV within BC biopsies has revealed that the diversity in the conclusions remain, however, they also show more of an association between EBV and BC biopsies in some study locations. Here, we review the evidence linking EBV with BC, and conclude that the evidence for the presence of EBV in BC biopsies is concentrated in specific geographic regions but is currently insufficient to provide a causal link. We pose some questions that could help to resolve the question of whether EBV contributes to BC and probe the contribution EBV might make to the aetiology of BC.
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van Wijk SW, Ramos KS, Brundel BJJM. Cardioprotective Role of Heat Shock Proteins in Atrial Fibrillation: From Mechanism of Action to Therapeutic and Diagnostic Target. Int J Mol Sci 2021; 22:ijms22010442. [PMID: 33466228 PMCID: PMC7795054 DOI: 10.3390/ijms22010442] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 02/07/2023] Open
Abstract
Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia worldwide and is associated with ischemic stroke, heart failure, and substantial morbidity and mortality. Unfortunately, current AF therapy is only moderately effective and does not prevent AF progression from recurrent intermittent episodes (paroxysmal) to persistent and finally permanent AF. It has been recognized that AF persistence is related to the presence of electropathology. Electropathology is defined as structural damage, including degradation of sarcomere structures, in the atrial tissue which, in turn, impairs electrical conduction and subsequently the contractile function of atrial cardiomyocytes. Recent research findings indicate that derailed proteostasis underlies structural damage and, consequently, electrical conduction impairment. A healthy proteostasis is of vital importance for proper function of cells, including cardiomyocytes. Cells respond to a loss of proteostatic control by inducing a heat shock response (HSR), which results in heat shock protein (HSP) expression. Emerging clinical evidence indicates that AF-induced proteostasis derailment is rooted in exhaustion of HSPs. Cardiomyocytes lose defense against structural damage-inducing pathways, which drives progression of AF and induction of HSP expression. In particular, small HSPB1 conserves sarcomere structures by preventing their degradation by proteases, and overexpression of HSPB1 accelerates recovery from structural damage in experimental AF model systems. In this review, we provide an overview of the mechanisms of action of HSPs in preventing AF and discuss the therapeutic potential of HSP-inducing compounds in clinical AF, as well as the potential of HSPs as biomarkers to discriminate between the various stages of AF and recurrence of AF after treatment.
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Affiliation(s)
- Stan W. van Wijk
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (K.S.R.); (B.J.J.M.B.)
- Correspondence:
| | - Kennedy S. Ramos
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (K.S.R.); (B.J.J.M.B.)
- Erasmus Medical Center, Department of Cardiology, 3015 GD Rotterdam, The Netherlands
| | - Bianca J. J. M. Brundel
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (K.S.R.); (B.J.J.M.B.)
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13
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Cheng Y, Sun F, Wang L, Gao M, Xie Y, Sun Y, Liu H, Yuan Y, Yi W, Huang Z, Yan H, Peng K, Wu Y, Cao Z. Virus-induced p38 MAPK activation facilitates viral infection. Am J Cancer Res 2020; 10:12223-12240. [PMID: 33204339 PMCID: PMC7667676 DOI: 10.7150/thno.50992] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/17/2020] [Indexed: 12/27/2022] Open
Abstract
Rationale: Many viral infections are known to activate the p38 mitogen-activated protein kinase (MAPK) signaling pathway. However, the role of p38 activation in viral infection and the underlying mechanism remain unclear. The role of virus-hijacked p38 MAPK activation in viral infection was investigated in this study. Methods: The correlation of hepatitis C virus (HCV) infection and p38 activation was studied in patient tissues and primary human hepatocytes (PHHs) by immunohistochemistry and western blotting. Coimmunoprecipitation, GST pulldown and confocal microscopy were used to investigate the interaction of p38α and the HCV core protein. In vitro kinase assays and mass spectrometry were used to analyze the phosphorylation of the HCV core protein. Plaque assays, quantitative real time PCR (qRT-PCR), western blotting, siRNA and CRISPR/Cas9 were used to determine the effect of p38 activation on viral replication. Results: HCV infection was associated with p38 activation in clinical samples. HCV infection increased p38 phosphorylation by triggering the interaction of p38α and TGF-β activated kinase 1 (MAP3K7) binding protein 1 (TAB1). TAB1-mediated p38α activation facilitated HCV replication, and pharmaceutical inhibition of p38α activation by SB203580 suppressed HCV infection at the viral assembly step. Activated p38α interacted with the N-terminal region of the HCV core protein and subsequently phosphorylated the HCV core protein, which promoted HCV core protein oligomerization, an essential step for viral assembly. As expected, SB203580 or the HCV core protein N-terminal peptide (CN-peptide) disrupted the p38α-HCV core protein interaction, efficiently impaired HCV assembly and impeded normal HCV replication in both cultured cells and primary human hepatocytes. Similarly, severe fever with thrombocytopenia syndrome virus (SFTSV), herpes simplex virus type 1 (HSV-1) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection also activated p38 MAPK. Most importantly, pharmacological blockage of p38 activation by SB203580 effectively inhibited SFTSV, HSV-1 and SARS-CoV-2. Conclusion: Our study shows that virus-hijacked p38 activation is a key event for viral replication and that pharmacological blockage of p38 activation is an antiviral strategy.
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14
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Van R, Cuevas-Navarro A, Castel P, McCormick F. The molecular functions of RIT1 and its contribution to human disease. Biochem J 2020; 477:2755-2770. [PMID: 32766847 PMCID: PMC7787054 DOI: 10.1042/bcj20200442] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 12/29/2022]
Abstract
RIT1 is a member of the Ras family of GTPases that direct broad cellular physiological responses through tightly controlled signaling networks. The canonical Ras GTPases are well-defined regulators of the RAF/MEK/ERK pathway and mutations in these are pathogenic in cancer and a class of developmental disorders termed RASopathies. Emerging clinical evidences have now demonstrated a role for RIT1 in RASopathies, namely Noonan syndrome, and various cancers including lung adenocarcinoma and myeloid malignancies. While RIT1 has been mostly described in the context of neuronal differentiation and survival, the mechanisms underlying aberrant RIT1-mediated signaling remain elusive. Here, we will review efforts undertaken to characterize the biochemical and functional properties of the RIT1 GTPase at the molecular, cellular, and organismal level, as well as provide a phenotypic overview of different human conditions caused by RIT1 mutations. Deeper understanding of RIT1 biological function and insight to its pathogenic mechanisms are imperative to developing effective therapeutic interventions for patients with RIT1-mutant Noonan syndrome and cancer.
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Affiliation(s)
- Richard Van
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, U.S.A
| | - Antonio Cuevas-Navarro
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, U.S.A
| | - Pau Castel
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, U.S.A
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, U.S.A
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15
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Yin L, Chen X, Ji H, Gao S. Dexmedetomidine protects against sepsis‑associated encephalopathy through Hsp90/AKT signaling. Mol Med Rep 2019; 20:4731-4740. [PMID: 31702043 DOI: 10.3892/mmr.2019.10718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 09/04/2019] [Indexed: 11/06/2022] Open
Abstract
Sepsis‑associated encephalopathy (SAE) is characterized by neuronal apoptosis and changes in mental status. Accumulating evidence has. indicated that dexmedetomidine is capable of protecting the brain against external stimuli and improving cognitive dysfunctions. The aim of the present study was to investigate the possible neuroprotective effects of dexmedetomidine on SAE and the role of heat‑shock protein (Hsp)90/AKT signaling in an experimental model of sepsis. The SAE model was established by cecal ligation and perforation (CLP) in vivo and lipopolysaccharide (LPS) treated hippocampal neuronal cultures in vitro. It was found that dexmedetomidine inhibited caspase‑3, but increased the expression level ofBcl‑2 in CLP rats. CLP rats also exhibited a decreased level of phosphorylated AKT Thr 308 and Hsp90, and their expression could be reversed by treatment with dexmedetomidine. Additionally, application of dexmedetomidine increased cell survival and decreased neuronal apoptosis in vitro. Furthermore, the neuroprotective effects of dexmedetomidine could be reversed by 17‑AAG (a Hsp90 inhibitor), or wortmannin (a PI3K inhibitor). Analysis of TUNEL staining indicated that dexmedetomidine improved LPS‑induced neuronal apoptosis, which could be eradicated by AKT short hairpin RNA transfection, prazosin or yohimbine. Finally, dexmedetomidine ameliorated both the emotional and spatial cognitive disorders without alteration in locomotor activity. The present findings suggested that dexmedetomidine may protect the brain against SAE, and that the Hsp90/AKT pathway may be involved in this process.
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Affiliation(s)
- Lijun Yin
- Department of Anesthesiology, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin 301800, P.R. China
| | - Xuejun Chen
- Department of Anesthesiology, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin 301800, P.R. China
| | - Hongbo Ji
- Department of Anesthesiology, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin 301800, P.R. China
| | - Shunli Gao
- Department of Anesthesiology, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin 301800, P.R. China
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Villegas SN, Ferres-Marco D, Domínguez M. Using Drosophila Models and Tools to Understand the Mechanisms of Novel Human Cancer Driver Gene Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1167:15-35. [PMID: 31520347 DOI: 10.1007/978-3-030-23629-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The formation, overgrowth and metastasis of tumors comprise a complex series of cellular and molecular events resulting from the combined effects of a variety of aberrant signaling pathways, mutations, and epigenetic alterations. Modeling this complexity in vivo requires multiple genes to be manipulated simultaneously, which is technically challenging. Here, we analyze how Drosophila research can further contribute to identifying pathways and elucidating mechanisms underlying novel cancer driver (risk) genes associated with tumor growth and metastasis in humans.
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Affiliation(s)
- Santiago Nahuel Villegas
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), Alicante, Spain.
| | - Dolors Ferres-Marco
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), Alicante, Spain.
| | - María Domínguez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), Alicante, Spain
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17
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Abe K, Yano T, Tanno M, Miki T, Kuno A, Sato T, Kouzu H, Nakata K, Ohwada W, Kimura Y, Sugawara H, Shibata S, Igaki Y, Ino S, Miura T. mTORC1 inhibition attenuates necroptosis through RIP1 inhibition-mediated TFEB activation. Biochim Biophys Acta Mol Basis Dis 2019; 1865:165552. [PMID: 31499159 DOI: 10.1016/j.bbadis.2019.165552] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 08/22/2019] [Accepted: 09/04/2019] [Indexed: 01/15/2023]
Abstract
Accumulating evidence indicates that necroptosis contributes to cardiovascular diseases. We recently reported suppression of autophagy by necroptotic signals in cardiomyocytes and protective action of rapamycin. Here we examined the mechanism by which mTORC1 inhibition protects cardiomyocytes from necroptosis. Necroptosis of H9c2 cells was induced by treatment with tumor necrotic factor-α (TNF) and z-VAD-fmk (zVAD), and the extent of necroptosis was determined as the level of LDH release (as % of total). TNF/zVAD increased RIP1-RIP3 interaction and LDH release from 3.4 ± 1.3% to 46.1 ± 2.3%. The effects of TNF/zVAD were suppressed by an mTORC1 inhibitor, rapamycin, and an mTORC1/2 inhibitor, Ku-0063794, but not by a p70s6K inhibitor, PF-4708671. Protection by rapamycin was not abolished by inhibitors of TAK1, IKKα/β, and cIAP, endogenous necroptosis suppressors upstream of RIP1. Rapamycin and Ku-0063794 suppressed TNF/zVAD-induced RIP1-Ser166 phosphorylation and increased phosphorylation of RIP1-Ser320, an inhibitory phosphorylation site, though such an effect on RIP1-Ser320 was not observed for PF-4708671. Protective effects of rapamycin on TNF/zVAD-induced RIP1-RIP3 binding and necroptosis were undetected in cells transfected with RIP1-S320A. In TNF/zVAD-treated cells, rapamycin and a RIP1 inhibitor, necrostatin-1, increased nuclear localization of transcriptional factor EB (TFEB) and promoted autolysosome formation from autophagosomes in a TFEB-dependent manner. Knockdown of TFEB expression attenuated rapamycin-induced protection from necroptosis in TNF/zVAD-treated cells. The results suggest that mTORC1 inhibition promotes autophagy and protects cardiomyocytes from necroptosis by a TFEB-dependent mechanism and that inhibition of RIP1 by increased phosphorylation at Ser320 is crucial in the cardiomyocyte protection afforded by mTORC1 inhibition.
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Affiliation(s)
- Koki Abe
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Toshiyuki Yano
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masaya Tanno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Miki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Atsushi Kuno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Pharmacology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tatsuya Sato
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Cell Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hidemichi Kouzu
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Kei Nakata
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Wataru Ohwada
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yukishige Kimura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hirohito Sugawara
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Satoru Shibata
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yusuke Igaki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shoya Ino
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
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18
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Takahara S, Inoue SI, Miyagawa-Tomita S, Matsuura K, Nakashima Y, Niihori T, Matsubara Y, Saiki Y, Aoki Y. New Noonan syndrome model mice with RIT1 mutation exhibit cardiac hypertrophy and susceptibility to β-adrenergic stimulation-induced cardiac fibrosis. EBioMedicine 2019; 42:43-53. [PMID: 30898653 PMCID: PMC6491386 DOI: 10.1016/j.ebiom.2019.03.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Noonan syndrome (NS) is a genetic disorder characterized by short stature, a distinctive facial appearance, and heart defects. We recently discovered a novel NS gene, RIT1, which is a member of the RAS subfamily of small GTPases. NS patients with RIT1 mutations have a high incidence of hypertrophic cardiomyopathy and edematous phenotype, but the specific role of RIT1 remains unclear. METHODS To investigate how germline RIT1 mutations cause NS, we generated knock-in mice that carried a NS-associated Rit1 A57G mutation (Rit1A57G/+). We investigated the phenotypes of Rit1A57G/+ mice in fetal and adult stages as well as the effects of isoproterenol on cardiac function in Rit1A57G/+ mice. FINDINGS Rit1A57G/+ embryos exhibited decreased viability, edema, subcutaneous hemorrhage and AKT activation. Surviving Rit1A57G/+ mice had a short stature, craniofacial abnormalities and splenomegaly. Cardiac hypertrophy and cardiac fibrosis with increased expression of S100A4, vimentin and periostin were observed in Rit1A57G/+ mice compared to Rit1+/+ mice. Upon isoproterenol stimulation, cardiac fibrosis was drastically increased in Rit1A57G/+ mice. Phosphorylated (at Thr308) AKT levels were also elevated in isoproterenol-treated Rit1A57G/+ hearts. INTERPRETATION The A57G mutation in Rit1 causes cardiac hypertrophy, fibrosis and other NS-associated features. Biochemical analysis indicates that the AKT signaling pathway might be related to downstream signaling in the RIT1 A57G mutant at a developmental stage and under β-adrenergic stimulation in the heart. FUND: The Grants-in-Aid were provided by the Practical Research Project for Rare/Intractable Diseases from the Japan Agency for Medical Research and Development, the Japan Society for the Promotion of Science KAKENHI Grant.
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Affiliation(s)
- Shingo Takahara
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan; Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Shin-Ichi Inoue
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Sachiko Miyagawa-Tomita
- Department of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan; Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Animal Nursing Science, Yamazaki University of Animal Health Technology, Tokyo, Japan
| | - Katsuhisa Matsuura
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan; Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Yasumi Nakashima
- Department of Pediatrics, Seirei Hamamatsu General Hospital, Hamamatsu, Japan
| | - Tetsuya Niihori
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoichi Matsubara
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan; National Center for Child Health and Development, Tokyo, Japan
| | - Yoshikatsu Saiki
- Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan.
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Obergasteiger J, Frapporti G, Pramstaller PP, Hicks AA, Volta M. A new hypothesis for Parkinson's disease pathogenesis: GTPase-p38 MAPK signaling and autophagy as convergence points of etiology and genomics. Mol Neurodegener 2018; 13:40. [PMID: 30071902 PMCID: PMC6090926 DOI: 10.1186/s13024-018-0273-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 07/19/2018] [Indexed: 02/07/2023] Open
Abstract
The combination of genetics and genomics in Parkinson´s disease has recently begun to unveil molecular mechanisms possibly underlying disease onset and progression. In particular, catabolic processes such as autophagy have been increasingly gaining relevance as post-mortem evidence and experimental models suggested a participation in neurodegeneration and alpha-synuclein Lewy body pathology. In addition, familial Parkinson´s disease linked to LRRK2 and alpha-synuclein provided stronger correlation between etiology and alterations in autophagy. More detailed cellular pathways are proposed and genetic risk factors that associate with idiopathic Parkinson´s disease provide further clues in dissecting contributions of single players. Nevertheless, the fine-tuning of these processes remains elusive, as the initial stages of the pathways are not yet clarified.In this review, we collect literature evidence pointing to autophagy as the common, downstream target of Parkinsonian dysfunctions and augment current knowledge on the factors that direct the subsequent steps. Cell and molecular biology evidence indicate that p38 signaling underlies neurodegeneration and autoptic observations suggest a participation in neuropathology. Moreover, alpha-synuclein and LRRK2 also appear involved in the p38 pathway with additional roles in the regulation of GTPase signaling. Small GTPases are critical modulators of p38 activation and thus, their functional interaction with aSyn and LRRK2 could explain much of the detailed mechanics of autophagy in Parkinson´s disease.We propose a novel hypothesis for a more comprehensive working model where autophagy is controlled by upstream pathways, such as GTPase-p38, that have been so far underexplored in this context. In addition, etiological factors (LRRK2, alpha-synuclein) and risk loci might also combine in this common mechanism, providing a powerful experimental setting to dissect the cause of both familial and idiopathic disease.
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Affiliation(s)
- Julia Obergasteiger
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Giulia Frapporti
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
- Department of Neurology, General Central Hospital, Via Böhler 5, 39100 Bolzano, Italy
- Department of Neurology, University of Lübeck, Ratzeburger Allee, 23538 Lübeck, Germany
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Mattia Volta
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
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20
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Mir S, Andres DA. Small GTPase RIT1 in Mouse Retina; Cellular and Functional Analysis. Curr Eye Res 2018; 43:1160-1168. [PMID: 29843527 DOI: 10.1080/02713683.2018.1482557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
PURPOSE Ras-like without CAAX 1 (RIT1/Rit) is a member of the Ras subfamily of small GTP-binding proteins with documented roles in regulating neuronal function, including contributions to neurotrophin signaling, neuronal survival, and neurogenesis. The aim of the study was to (1) examine the expression of RIT1 protein in mouse retina and retinal cell types and (2) determine whether RIT1 contributes to retinal ganglion cell (RGC) survival and synaptic stability following excitotoxic stress. MATERIALS AND METHODS Gene expression and immunohistochemical analysis were used to examine RIT1 expression in the mouse retina. Primary RGC and Müller glia cultures were used to validate novel RIT1 lentiviral RNAi silencing reagents, and to demonstrate that RIT1 loss does not alter RGC morphology. Finally, in vitro glutamate exposure identified a role for RIT1 in the adaptation of RGCs to excitotoxic stress. RESULTS Gene expression analysis and immunohistochemical studies in whole eyes and primary cell culture demonstrate RIT1 expression throughout the retina, including Müller glia and RGCs. While genetic RIT1 knockout (RIT1-KO) does not affect gross retinal anatomy, including the thickness of constituent retinal layers or RGC cell numbers, RNAi-mediated RIT1 silencing results in increased RGC death and synaptic loss following exposure to excitotoxic stress. CONCLUSIONS RIT1 is widely expressed in the murine retina, including both Müller glia and RGCs. While genetic deletion of RIT1 does not result in gross retinal abnormalities, these studies identify a novel role for RIT1 in the adaptation of RGC to excitotoxic stress, with RIT1 promoting both neuronal survival and the retention of PSD-95+ synapses.
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Affiliation(s)
- Sajad Mir
- a Department of Molecular and Cellular Biochemistry , University of Kentucky, College of Medicine , Lexington , Kentucky , US
| | - Douglas A Andres
- a Department of Molecular and Cellular Biochemistry , University of Kentucky, College of Medicine , Lexington , Kentucky , US
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21
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Meyer zum Büschenfelde U, Brandenstein LI, von Elsner L, Flato K, Holling T, Zenker M, Rosenberger G, Kutsche K. RIT1 controls actin dynamics via complex formation with RAC1/CDC42 and PAK1. PLoS Genet 2018; 14:e1007370. [PMID: 29734338 PMCID: PMC5937737 DOI: 10.1371/journal.pgen.1007370] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
Abstract
RIT1 belongs to the RAS family of small GTPases. Germline and somatic RIT1 mutations have been identified in Noonan syndrome (NS) and cancer, respectively. By using heterologous expression systems and purified recombinant proteins, we identified the p21-activated kinase 1 (PAK1) as novel direct effector of RIT1. We found RIT1 also to directly interact with the RHO GTPases CDC42 and RAC1, both of which are crucial regulators of actin dynamics upstream of PAK1. These interactions are independent of the guanine nucleotide bound to RIT1. Disease-causing RIT1 mutations enhance protein-protein interaction between RIT1 and PAK1, CDC42 or RAC1 and uncouple complex formation from serum and growth factors. We show that the RIT1-PAK1 complex regulates cytoskeletal rearrangements as expression of wild-type RIT1 and its mutant forms resulted in dissolution of stress fibers and reduction of mature paxillin-containing focal adhesions in COS7 cells. This effect was prevented by co-expression of RIT1 with dominant-negative CDC42 or RAC1 and kinase-dead PAK1. By using a transwell migration assay, we show that RIT1 wildtype and the disease-associated variants enhance cell motility. Our work demonstrates a new function for RIT1 in controlling actin dynamics via acting in a signaling module containing PAK1 and RAC1/CDC42, and highlights defects in cell adhesion and migration as possible disease mechanism underlying NS. Noonan syndrome (NS) belongs to the RASopathies, a group of developmental diseases caused by mutations in genes encoding RAS-MAPK pathway components. Germline mutations in RIT1 have been identified in NS. RIT1 belongs to the RAS superfamily, however, the cellular function of RIT1 remains elusive. We show that RIT1 binds p21-activated kinase 1 (PAK1), an effector of the RHO GTPases RAC1 and CDC42, which are important regulators of cytoskeletal dynamics. NS-associated RIT1 mutants enhance complex formation between RIT1, RAC1/CDC42 and PAK1. Expression of wild-type or mutant forms of RIT1 caused loss of stress fibers and mature focal adhesions and enhanced cell motility. Our data suggest that dysfunction in actin dynamics is a novel aspect in the pathophysiology of RASopathies.
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Affiliation(s)
| | | | - Leonie von Elsner
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kristina Flato
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tess Holling
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
| | - Georg Rosenberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail: (KK); (GR)
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail: (KK); (GR)
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Li Y, Köpper F, Dobbelstein M. Inhibition of MAPKAPK2/MK2 facilitates DNA replication upon cancer cell treatment with gemcitabine but not cisplatin. Cancer Lett 2018; 428:45-54. [PMID: 29704518 DOI: 10.1016/j.canlet.2018.04.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/10/2018] [Accepted: 04/22/2018] [Indexed: 02/07/2023]
Abstract
The signaling pathway driven by p38 and MAPKAPK2 alias MK2 is activated as part of stress responses, and these kinases represent attractive drug targets for cancer therapy. However, seemingly conflicting results were obtained when assessing the role of MK2 in chemotherapy. MK2 inhibitors were reported to either enhance or diminish the chemosensitivity of cancer cells. Here we show that this strongly depends on the particular chemotherapeutic drug. Two different MK2 inhibitors increased the proliferating fraction of pancreatic cancer-derived cells upon treatment with gemcitabine, whereas no consistent protection against cisplatin was observed. Both drugs enhanced, rather than attenuated, the toxicity of another DNA crosslinking agent, mitomycin C. Gemcitabine and cisplatin were each capable of activating MK2, and we did not observe differences in the intracellular localization of MK2 upon treatment. However, DNA replication fork progression, as determined by fiber assays, was restored by MK2 inhibition upon treatment with gemcitabine, but not when cisplatin was used. Thus, MK2 is required for the reduction in DNA replication in response to gemcitabine but not to cisplatin. These observations raise the need to carefully evaluate synergisms and antagonisms with conventional chemotherapeutics when taking MK2 inhibitors to the clinics.
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Affiliation(s)
- Yizhu Li
- Institute of Molecular Oncology, Göttingen Center of Molecular Biosciences (GZMB), University Medical Center Göttingen, D-37077, Göttingen, Germany
| | - Frederik Köpper
- Institute of Molecular Oncology, Göttingen Center of Molecular Biosciences (GZMB), University Medical Center Göttingen, D-37077, Göttingen, Germany
| | - Matthias Dobbelstein
- Institute of Molecular Oncology, Göttingen Center of Molecular Biosciences (GZMB), University Medical Center Göttingen, D-37077, Göttingen, Germany.
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Nakhaei-Rad S, Haghighi F, Nouri P, Rezaei Adariani S, Lissy J, Kazemein Jasemi NS, Dvorsky R, Ahmadian MR. Structural fingerprints, interactions, and signaling networks of RAS family proteins beyond RAS isoforms. Crit Rev Biochem Mol Biol 2018; 53:130-156. [PMID: 29457927 DOI: 10.1080/10409238.2018.1431605] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Saeideh Nakhaei-Rad
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Fereshteh Haghighi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Parivash Nouri
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Soheila Rezaei Adariani
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Jana Lissy
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Neda S Kazemein Jasemi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Radovan Dvorsky
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Mohammad Reza Ahmadian
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
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24
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IGF-1 mediated Neurogenesis Involves a Novel RIT1/Akt/Sox2 Cascade. Sci Rep 2017; 7:3283. [PMID: 28607354 PMCID: PMC5468318 DOI: 10.1038/s41598-017-03641-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/02/2017] [Indexed: 12/20/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) is known to have diverse effects on brain structure and function, including the promotion of stem cell proliferation and neurogenesis in the adult dentate gyrus. However, the intracellular pathways downstream of the IGF-1 receptor that contribute to these diverse physiological actions remain relatively uncharacterized. Here, we demonstrate that the Ras-related GTPase, RIT1, plays a critical role in IGF-1-dependent neurogenesis. Studies in hippocampal neuronal precursor cells (HNPCs) demonstrate that IGF-1 stimulates a RIT1-dependent increase in Sox2 levels, resulting in pro-neural gene expression and increased cellular proliferation. In this novel cascade, RIT1 stimulates Akt-dependent phosphorylation of Sox2 at T118, leading to its stabilization and transcriptional activation. When compared to wild-type HNPCs, RIT1−/− HNPCs show deficient IGF-1-dependent Akt signaling and neuronal differentiation, and accordingly, Sox2-dependent hippocampal neurogenesis is significantly blunted following IGF-1 infusion in knockout (RIT1−/−) mice. Consistent with a role for RIT1 function in the modulation of activity-dependent plasticity, exercise-mediated potentiation of hippocampal neurogenesis is also diminished in RIT1−/− mice. Taken together, these data identify the previously uncharacterized IGF1-RIT1-Akt-Sox2 signaling pathway as a key component of neurogenic niche sensing, contributing to the regulation of neural stem cell homeostasis.
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25
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Chen X, Liu L, Wang Y, Liu B, Zeng D, Jin Q, Li M, Zhang D, Liu Q, Xie H. Identification of breast cancer recurrence risk factors based on functional pathways in tumor and normal tissues. Oncotarget 2017; 8:20679-20694. [PMID: 27564264 PMCID: PMC5400536 DOI: 10.18632/oncotarget.11557] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 07/26/2016] [Indexed: 01/05/2023] Open
Abstract
The recurrence of breast cancer (BC) is a serious therapeutic problem, and the risk factors for recurrence urgently need to be identified. In this study, we examined the functional pathways in tumor and normal tissues to more comprehensively identify biomarkers for the risk of BC recurrence. We collected tumor and normal tissue gene expression profiles of recurrent BC patients and non-recurrent BC patients from the TCGA database.We derived an expression interval (mean ± 1.96SD) based on non-recurrent patients rather than a single value, such as a mean or median. If the expression of a gene was significantly different from its normal expression interval, it was considered a differentially expressed gene. Eight pathways that significantly distinguished recurrent and non-recurrent BC patients were obtained based on 65% accuracy, and these pathways were all associated with the immune response and sensitivity to drugs. The genes in these eight pathways were also used to analyze survival, and the significance level reached 0.003 in an independent dataset (p = 0.02 in tumor and p = 0.03 in normal tissue). Our results reveal that the integration of tumor and normal tissue functional analyses can comprehensively enhance the understanding of BC prognosis.
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Affiliation(s)
- Xiujie Chen
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Lei Liu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - YunFeng Wang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Bo Liu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Diheng Zeng
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Qing Jin
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - MengJian Li
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - DeNan Zhang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Qiuqi Liu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
| | - Hongbo Xie
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, 150081, PR China
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26
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Terriente-Félix A, Pérez L, Bray SJ, Nebreda AR, Milán M. A Drosophila model of myeloproliferative neoplasm reveals a feed-forward loop in the JAK pathway mediated by p38 MAPK signalling. Dis Model Mech 2017; 10:399-407. [PMID: 28237966 PMCID: PMC5399568 DOI: 10.1242/dmm.028118] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/01/2017] [Indexed: 12/25/2022] Open
Abstract
Myeloproliferative neoplasms (MPNs) of the Philadelphia-negative class comprise polycythaemia vera, essential thrombocythaemia and primary myelofibrosis (PMF). They are associated with aberrant numbers of myeloid lineage cells in the blood, and in the case of overt PMF, with development of myelofibrosis in the bone marrow and failure to produce normal blood cells. These diseases are usually caused by gain-of-function mutations in the kinase JAK2. Here, we use Drosophila to investigate the consequences of activation of the JAK2 orthologue in haematopoiesis. We have identified maturing haemocytes in the lymph gland, the major haematopoietic organ in the fly, as the cell population susceptible to induce hypertrophy upon targeted overexpression of JAK. We show that JAK activates a feed-forward loop, including the cytokine-like ligand Upd3 and its receptor, Domeless, which are required to induce lymph gland hypertrophy. Moreover, we present evidence that p38 MAPK signalling plays a key role in this process by inducing expression of the ligand Upd3. Interestingly, we also show that forced activation of the p38 MAPK pathway in maturing haemocytes suffices to generate hypertrophic organs and the appearance of melanotic tumours. Our results illustrate a novel pro-tumourigenic crosstalk between the p38 MAPK pathway and JAK signalling in a Drosophila model of MPNs. Based on the shared molecular mechanisms underlying MPNs in flies and humans, the interplay between Drosophila JAK and p38 signalling pathways unravelled in this work might have translational relevance for human MPNs. Summary: Pro-tumourigenic crosstalk occurs between the p38 MAPK pathway and JAK signalling in a Drosophila model of myeloproliferative neoplasm.
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Affiliation(s)
- Ana Terriente-Félix
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Lidia Pérez
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Sarah J Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Angel R Nebreda
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain .,ICREA, Pg. Lluís Companys 23, Barcelona 08010, Spain
| | - Marco Milán
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain .,ICREA, Pg. Lluís Companys 23, Barcelona 08010, Spain
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27
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Manta AK, Papadopoulou D, Polyzos AP, Fragopoulou AF, Skouroliakou AS, Thanos D, Stravopodis DJ, Margaritis LH. Mobile-phone radiation-induced perturbation of gene-expression profiling, redox equilibrium and sporadic-apoptosis control in the ovary of Drosophila melanogaster. Fly (Austin) 2016; 11:75-95. [PMID: 27960592 DOI: 10.1080/19336934.2016.1270487] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The daily use by people of wireless communication devices has increased exponentially in the last decade, begetting concerns regarding its potential health hazards. Drosophila melanogaster four days-old adult female flies were exposed for 30 min to radiation emitted by a commercial mobile phone at a SAR of 0.15 W/kg and a SAE of 270 J/kg. ROS levels and apoptotic follicles were assayed in parallel with a genome-wide microarrays analysis. ROS cellular contents were found to increase by 1.6-fold (x), immediately after the end of exposure, in follicles of pre-choriogenic stages (germarium - stage 10), while sporadically generated apoptotic follicles (germarium 2b and stages 7-9) presented with an averaged 2x upregulation in their sub-population mass, 4 h after fly's irradiation with mobile device. Microarray analysis revealed 168 genes being differentially expressed, 2 h post-exposure, in response to radiofrequency (RF) electromagnetic field-radiation exposure (≥1.25x, P < 0.05) and associated with multiple and critical biological processes, such as basic metabolism and cellular subroutines related to stress response and apoptotic death. Exposure of adult flies to mobile-phone radiation for 30 min has an immediate impact on ROS production in animal's ovary, which seems to cause a global, systemic and non-targeted transcriptional reprogramming of gene expression, 2 h post-exposure, being finally followed by induction of apoptosis 4 h after the end of exposure. Conclusively, this unique type of pulsed radiation, mainly being derived from daily used mobile phones, seems capable of mobilizing critical cytopathic mechanisms, and altering fundamental genetic programs and networks in D. melanogaster.
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Affiliation(s)
- Areti K Manta
- a Section of Cell Biology and Biophysics, Department of Biology , National and Kapodistrian University of Athens , Athens , Greece
| | - Deppie Papadopoulou
- b Basic Research Center , Biomedical Research Foundation of the Academy of Athens , Athens , Greece
| | - Alexander P Polyzos
- b Basic Research Center , Biomedical Research Foundation of the Academy of Athens , Athens , Greece
| | - Adamantia F Fragopoulou
- a Section of Cell Biology and Biophysics, Department of Biology , National and Kapodistrian University of Athens , Athens , Greece
| | - Aikaterini S Skouroliakou
- c Department of Energy Technology Engineering , Technological Educational Institute of Athens , Athens , Greece
| | - Dimitris Thanos
- b Basic Research Center , Biomedical Research Foundation of the Academy of Athens , Athens , Greece
| | - Dimitrios J Stravopodis
- a Section of Cell Biology and Biophysics, Department of Biology , National and Kapodistrian University of Athens , Athens , Greece
| | - Lukas H Margaritis
- a Section of Cell Biology and Biophysics, Department of Biology , National and Kapodistrian University of Athens , Athens , Greece
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28
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Latham Birt SH, Purcell R, Botham KM, Wheeler-Jones CPD. Endothelial HO-1 induction by model TG-rich lipoproteins is regulated through a NOX4-Nrf2 pathway. J Lipid Res 2016; 57:1204-18. [PMID: 27185859 PMCID: PMC4918850 DOI: 10.1194/jlr.m067108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Indexed: 12/17/2022] Open
Abstract
Circulating levels of chylomicron remnants (CMRs) increase postprandially and their composition directly reflects dietary lipid intake. These TG-rich lipoproteins likely contribute to the development of endothelial dysfunction, albeit via unknown mechanisms. Here, we investigated how the FA composition of CMRs influences their actions on human aortic endothelial cells (HAECs) by comparing the effects of model CMRs-artificial TG-rich CMR-like particles (A-CRLPs)-containing TGs extracted from fish, DHA-rich algal, corn, or palm oils. HAECs responded with distinct transcriptional programs according to A-CRLP TG content and oxidation status, with genes involved in antioxidant defense and cytoprotection most prominently affected by n-3 PUFA-containing A-CRLPs. These particles were significantly more efficacious inducers of heme oxygenase-1 (HO-1) than n-6 PUFA corn or saturated FA-rich palm CRLPs. Mechanistically, HO-1 induction by all CRLPs requires NADPH oxidase 4, with PUFA-containing particles additionally dependent upon mitochondrial reactive oxygen species. Activation of both p38 MAPK and PPARβ/δ culminates in increased nuclear factor erythroid 2-related factor 2 (Nrf2) expression/nuclear translocation and HO-1 induction. These studies define new molecular pathways coupling endothelial cell activation by model CMRs with adaptive regulation of Nrf2-dependent HO-1 expression and may represent key mechanisms through which dietary FAs differentially impact progression of endothelial dysfunction.
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Affiliation(s)
- Sally H Latham Birt
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London NW1 0TU, United Kingdom
| | - Robert Purcell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London NW1 0TU, United Kingdom
| | - Kathleen M Botham
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London NW1 0TU, United Kingdom
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29
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Nguyen Ho-Bouldoires TH, Clapéron A, Mergey M, Wendum D, Desbois-Mouthon C, Tahraoui S, Fartoux L, Chettouh H, Merabtene F, Scatton O, Gaestel M, Praz F, Housset C, Fouassier L. Mitogen-activated protein kinase-activated protein kinase 2 mediates resistance to hydrogen peroxide-induced oxidative stress in human hepatobiliary cancer cells. Free Radic Biol Med 2015; 89:34-46. [PMID: 26169728 DOI: 10.1016/j.freeradbiomed.2015.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/25/2015] [Accepted: 07/08/2015] [Indexed: 12/21/2022]
Abstract
The development and progression of liver cancer are characterized by increased levels of reactive oxygen species (ROS). ROS-induced oxidative stress impairs cell proliferation and ultimately leads to cell death. Although liver cancer cells are especially resistant to oxidative stress, mechanisms of such resistance remain understudied. We identified the MAPK-activated protein kinase 2 (MK2)/heat shock protein 27 (Hsp27) signaling pathway mediating defenses against oxidative stress. In addition to MK2 and Hsp27 overexpression in primary liver tumors compared to adjacent nontumorous tissues, the MK2/Hsp27 pathway is activated by hydrogen peroxide-induced oxidative stress in hepatobiliary cancer cells. MK2 inactivation or inhibition of MK2 or Hsp27 expression increases caspase-3 and PARP cleavage and DNA breaks and therefore cell death. Interestingly, MK2/Hsp27 inhibition decreases antioxidant defenses such as heme oxygenase 1 through downregulation of the transcription factor nuclear factor erythroid-derived 2-like 2. Moreover, MK2/Hsp27 inhibition decreases both phosphorylation of epidermal growth factor receptor (EGFR) and expression of its ligand, heparin-binding EGF-like growth factor. A new identified partner of MK2, the scaffold PDZ protein EBP50, could facilitate these effects through MK2/Hsp27 pathway regulation. These findings demonstrate that the MK2/Hsp27 pathway actively participates in resistance to oxidative stress and may contribute to liver cancer progression.
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Affiliation(s)
- Thanh Huong Nguyen Ho-Bouldoires
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Audrey Clapéron
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Martine Mergey
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Dominique Wendum
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Service d'Anatomie et Cytologie Pathologiques, AP-HP, Hôpital Saint-Antoine, F-75012 Paris, France
| | - Christèle Desbois-Mouthon
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Sylvana Tahraoui
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Laetitia Fartoux
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Service d'Hépatologie, AP-HP, Hôpital Saint-Antoine, F-75012 Paris, France
| | - Hamza Chettouh
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Fatiha Merabtene
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Olivier Scatton
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Service de Chirurgie Hépato-Biliaire et Transplantation Hépatique, AP-HP, Hôpital Saint-Antoine, F-75012 Paris, France
| | - Matthias Gaestel
- Institute of Physiological Chemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Françoise Praz
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France
| | - Chantal Housset
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Service d'Hépatologie, AP-HP, Hôpital Saint-Antoine, F-75012 Paris, France
| | - Laura Fouassier
- INSERM UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
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30
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Marada S, Truong A, Ogden SK. The small GTPase Rap1 is a modulator of Hedgehog signaling. Dev Biol 2015; 409:84-94. [PMID: 26481064 DOI: 10.1016/j.ydbio.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/31/2022]
Abstract
During development, the evolutionarily conserved Hedgehog (Hh) morphogen provides instructional cues that influence cell fate, cell affinity and tissue morphogenesis. To do so, the Hh signaling cascade must coordinate its activity with other morphogenetic signals. This can occur through engagement of or response to effectors that do not typically function as core Hh pathway components. Given the ability of small G proteins of the Ras family to impact cell survival, differentiation, growth and adhesion, we wanted to determine whether Hh and Ras signaling might intersect during development. We performed genetic modifier tests in Drosophila to examine the ability of select Ras family members to influence Hh signal output, and identified Rap1 as a positive modulator of Hh pathway activity. Our results suggest that Rap1 is activated to its GTP-bound form in response to Hh ligand, and that the GTPase exchange factor C3G likely contributes to this activation. The Rap1 effector Canoe (Cno) also impacts Hh signal output, suggesting that a C3G-Rap1-Cno axis intersects the Hh pathway during tissue morphogenesis.
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Affiliation(s)
- Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States; Rhodes College Summer Plus Program, Rhodes College, Memphis, TN 38112, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States.
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31
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Xu F, Sun S, Yan S, Guo H, Dai M, Teng Y. Elevated expression of RIT1 correlates with poor prognosis in endometrial cancer. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:10315-10324. [PMID: 26617739 PMCID: PMC4637554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 08/26/2015] [Indexed: 06/05/2023]
Abstract
RIT1, (Ras-like without CAAX1), the founding member of a novel branch of the Ras subfamily, mediates a wide variety of cellular functions, including cell proliferation, survival, and differentiation, and it may play crucial oncogenic role in human cancer. The purpose of the current study was to characterize the expression pattern of RIT1 and assess the clinical significance of RIT1 expression in endometrial cancer patients. The mRNA and protein expression of RIT1 was significantly overexpressed in 7 endometrial cancer cell lines by qPCR and Western blot, respectively. In addition, RIT1 mRNA expression was elevated in 36 freshly frozen endometrial cancer tissues compared to 21 non-cancerous endometrial tissue samples. Similar results were observed by analyzing GEO datasets. Immunohistochemistry was used to examine the protein expression of RIT1 in two tissue microarrays containing 257 cases of tumor and 31 non-tumor tissues, which showed that elevated expression of RIT1 was significantly correlated with pathological type, clinical stage, grade and vascular invasion. Importantly, Kaplan-Meier survival analysis indicated that RIT1 expression was associated with overall survival of endometrial cancer patients. Multivariate Cox regression analysis revealed that RIT1 expression was one of the independent prognostic factors for endometrial cancer patients. Furthermore, RIT1 combined with other clinicopathological risk factors was a more significant model in ROC curve comparison. In conclusion, elevated expression of RIT1 may contribute to the progression of endometrial cancer and thus may serve as a novel prognostic marker and a promising molecular target for the treatment of endometrial cancer.
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Affiliation(s)
- Fengjuan Xu
- Department of Obstetrics and Gynecology, The First People’s Hospital of TaicangJiangsu, PR China
| | - Su’an Sun
- Department of Obstetrics and Gynecology, Huai’an First People’s Hospital, Nanjing Medical UniversityHuai’an, Jiangsu, PR China
| | - Shilan Yan
- Department of Obstetrics and Gynecology, Huai’an First People’s Hospital, Nanjing Medical UniversityHuai’an, Jiangsu, PR China
| | - Hongling Guo
- Department of Obstetrics and Gynecology, The First People’s Hospital of TaicangJiangsu, PR China
| | - Miao Dai
- Department of Obstetric and Gynecology, Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai, PR China
| | - Yincheng Teng
- Department of Obstetric and Gynecology, Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai, PR China
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Koenighofer M, Hung CY, McCauley JL, Dallman J, Back EJ, Mihalek I, Gripp KW, Sol-Church K, Rusconi P, Zhang Z, Shi GX, Andres DA, Bodamer OA. Mutations in RIT1 cause Noonan syndrome - additional functional evidence and expanding the clinical phenotype. Clin Genet 2015; 89:359-66. [PMID: 25959749 DOI: 10.1111/cge.12608] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 04/05/2015] [Accepted: 05/05/2015] [Indexed: 12/24/2022]
Abstract
RASopathies are a clinically heterogeneous group of conditions caused by mutations in 1 of 16 proteins in the RAS-mitogen activated protein kinase (RAS-MAPK) pathway. Recently, mutations in RIT1 were identified as a novel cause for Noonan syndrome. Here we provide additional functional evidence for a causal role of RIT1 mutations and expand the associated phenotypic spectrum. We identified two de novo missense variants p.Met90Ile and p.Ala57Gly. Both variants resulted in increased MEK-ERK signaling compared to wild-type, underscoring gain-of-function as the primary functional mechanism. Introduction of p.Met90Ile and p.Ala57Gly into zebrafish embryos reproduced not only aspects of the human phenotype but also revealed abnormalities of eye development, emphasizing the importance of RIT1 for spatial and temporal organization of the growing organism. In addition, we observed severe lymphedema of the lower extremity and genitalia in one patient. We provide additional evidence for a causal relationship between pathogenic mutations in RIT1, increased RAS-MAPK/MEK-ERK signaling and the clinical phenotype. The mutant RIT1 protein may possess reduced GTPase activity or a diminished ability to interact with cellular GTPase activating proteins; however the precise mechanism remains unknown. The phenotypic spectrum is likely to expand and includes lymphedema of the lower extremities in addition to nuchal hygroma.
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Affiliation(s)
- M Koenighofer
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - C Y Hung
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Dr. John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL, USA.,Harvard Medical School, Boston, MA, USA
| | - J L McCauley
- Dr. John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL, USA.,John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - J Dallman
- Department of Biology, University of Miami, Miami, FL, USA
| | - E J Back
- Department of Biology, University of Miami, Miami, FL, USA
| | - I Mihalek
- Bioinformatics Institute A*STAR Singapore, Singapore
| | - K W Gripp
- Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - K Sol-Church
- Department of Pediatrics, Division of Pediatric Cardiology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - P Rusconi
- Department of Pediatrics, Division of Pediatric Cardiology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Z Zhang
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - G-X Shi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - D A Andres
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - O A Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
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Wu S, Cao X, He R, Xiong K. Detrimental impact of hyperlipidemia on the peripheral nervous system: A novel target of medical epidemiological and fundamental research study. Neural Regen Res 2015; 7:392-9. [PMID: 25774180 PMCID: PMC4350124 DOI: 10.3969/j.issn.1673-5374.2012.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 12/14/2011] [Indexed: 01/07/2023] Open
Abstract
Recently, epidemiological studies on the etiology of peripheral neuropathies have revealed that hyperlipidemia is a novel risk factor. Plasma lipid levels were confirmed to be associated with the incidence of many peripheral neuropathies including axonal distal polyneuropathy, vision and hearing loss, motor nerve system lesions and sympathetic nerve system dysfunction. Moreover, different lipid components such as cholesterol, triacylglycerols and lipoprotein are involved in the pathogenesis of these neuropathies. This review aimed to discuss the effect of hyperlipidemia on the peripheral nervous system and its association with peripheral neuropathies. Furthermore, a detailed discussion focusing on the explicit mechanisms related to hyperlipidemia-induced peripheral neuropathies is presented here. These mechanisms, including intracellular oxidative stress, inflammatory lesions, ischemia and dysregulation of local lipid metabolism, share pathways and interact mutually. In addition, we examined current information on clinical trials to prevent and treat peripheral neuropathies caused by hyperlipidemia, with a predictive discussion regarding the orientation of future investigations.
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Affiliation(s)
- Song Wu
- Department of Orthopedics, Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Xu Cao
- Clinical Medicine Eight-year Program, 01 Class, 07 Grade, Central South University, Changsha 410013, Hunan Province, China
| | - Rongzhen He
- Department of Orthopedics, Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Kun Xiong
- Department of Anatomy and Neurobiology, Xiangya Medical School of Central South University, Changsha 410013, Hunan Province, China
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34
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Cai W, Andres DA. mTORC2 is required for rit-mediated oxidative stress resistance. PLoS One 2014; 9:e115602. [PMID: 25531880 PMCID: PMC4274107 DOI: 10.1371/journal.pone.0115602] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/30/2014] [Indexed: 01/13/2023] Open
Abstract
Rit, a member of the Ras family of GTPases, has been shown to promote cell survival in response to oxidative stress, in part by directing an evolutionarily conserved p38 MAPK-Akt survival cascade. Aberrant Rit signaling has recently been implicated as a driver mutation in human cancer, adding importance to the characterization of critical Rit effector pathways. However, the mechanism by which Rit-p38 signaling regulated Akt activity was unknown. Here, we identify mTORC2 as a critical downstream mediator of Rit-dependent survival signaling in response to reactive oxygen species (ROS) stress. Rit interacts with Sin1 (MAPKAP1), and Rit loss compromises ROS-dependent mTORC2 complex activation, blunting mTORC2-mediated phosphorylation of Akt kinase. Taken together, our findings demonstrate that the p38/mTORC2/Akt signaling cascade mediates Rit-dependent oxidative stress survival. Inhibition of this previously unrecognized cascade should be explored as a potential therapy of Rit-dependent malignancies.
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Affiliation(s)
- Weikang Cai
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Douglas A. Andres
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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35
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Tian L, Chen J, Chen M, Gui C, Zhong CQ, Hong L, Xie C, Wu X, Yang L, Ahmad V, Han J. The p38 pathway regulates oxidative stress tolerance by phosphorylation of mitochondrial protein IscU. J Biol Chem 2014; 289:31856-31865. [PMID: 25204651 DOI: 10.1074/jbc.m114.589093] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The p38 pathway is an evolutionarily conserved signaling pathway that responds to a variety of stresses. However, the underlying mechanisms are largely unknown. In the present study, we demonstrate that p38b is a major p38 MAPK involved in the regulation of oxidative stress tolerance in addition to p38a and p38c in Drosophila. We further show the importance of MK2 as a p38-activated downstream kinase in resistance to oxidative stresses. Furthermore, we identified the iron-sulfur cluster scaffold protein IscU as a new substrate of MK2 both in Drosophila cells and in mammalian cells. These results imply a new mechanistic connection between the p38 pathway and mitochondria iron-sulfur clusters.
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Affiliation(s)
- Lili Tian
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Jianming Chen
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen, Fujian 361005, China, and.
| | - Mingliang Chen
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen, Fujian 361005, China, and
| | - Chloe Gui
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Chuan-Qi Zhong
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Lixin Hong
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Changchuan Xie
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Xiurong Wu
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Lirong Yang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen, Fujian 361005, China, and
| | - Vakil Ahmad
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
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36
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Wang B, Xiao JL, Ling YH, Meng XJ, Wu B, Yang XY, Zou F. BNIP3 upregulation by ERK and JNK mediates cadmium-induced necrosis in neuronal cells. Toxicol Sci 2014; 140:393-402. [PMID: 24824807 DOI: 10.1093/toxsci/kfu091] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cadmium (Cd) is a toxic heavy metal that may cause neurological disorders. We studied the mechanism underlying Cd-mediated cell death in neuronal cells. In Cd-induced neurotoxicity, caspase-3 was only modestly activated, and accordingly, zVAD-fmk, a pan-caspase inhibitor, partially attenuated cell death. However, pretreatment with Necrox-2 or Necrox-5, two novel necrosis inhibitors, suppressed cell death more markedly compared with pretreatment with zVAD-fmk. Moreover, the necrosis inhibitors did not prevent cleavage of caspase-3. These results indicate that caspase-independent necrosis is more prevalent in Cd-induced neurotoxicity. Bcl-2 and adenovirus E1B-19 kDa-interacting protein 3 (BNIP3) has been reported to be related to caspase-independent cell death. Cd treatment caused a dramatic upregulation of BNIP3 mRNA and protein levels in vitro and in vivo. Furthermore, knockdown of BNIP3 greatly inhibited Cd-induced cell death. Importantly, BNIP3 RNAi decreased lactate dehydrogenase release and the percentage of propidium iodide-positive cells, two markers of necrotic cell death due to rupture of the cell membrane, whereas it had no effect on activation of caspase-3 in Cd-treated cells. These data suggest that BNIP3 mediates caspase-independent necrosis, but not apoptosis. Moreover, our results indicate that induction of BNIP3 by Cd may not be related to HIF-1 which is generally regarded as a mediator responsible for BNIP3 expression. Finally, we show that mitogen-activated protein kinases (MAPKs) are activated by Cd in vitro and in vivo; ERK and JNK promote BNIP3 upregulation and subsequent necrosis. Taken together, our results suggest BNIP3, upregulated by activation of ERK and JNK, mediates Cd-induced necrosis in neuronal cells.
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Affiliation(s)
- Bin Wang
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Jia-Li Xiao
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Yi-Hui Ling
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xiao-Jing Meng
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Bing Wu
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xin-Yi Yang
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Fei Zou
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
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37
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Chatterjee N, Eom HJ, Choi J. Effects of silver nanoparticles on oxidative DNA damage-repair as a function of p38 MAPK status: a comparative approach using human Jurkat T cells and the nematode Caenorhabditis elegans. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:122-133. [PMID: 24347047 DOI: 10.1002/em.21844] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/19/2013] [Accepted: 12/01/2013] [Indexed: 06/03/2023]
Abstract
The large-scale use of silver nanoparticles (AgNPs) has raised concerns over potential impacts on the environment and human health. We previously reported that AgNP exposure causes an increase in reactive oxygen species, DNA damage, and induction of p38 MAPK and PMK-1 in Jurkat T cells and in Caenorhabditis elegans. To elucidate the underlying mechanisms of AgNP toxicity, here we evaluate the effects of AgNPs on oxidative DNA damage-repair (in human and C. elegans DNA glycosylases hOGG1, hNTH1, NTH-1, and 8-oxo-GTPases-hMTH1, NDX-4) and explore the role of p38 MAPK and PMK-1 in this process. Our comparative approach examined viability, gene expression, and enzyme activities in wild type (WT) and p38 MAPK knock-down (KD) Jurkat T cells (in vitro) and in WT and pmk-1 loss-of-function mutant strains of C. elegans (in vivo). The results suggest that p38 MAPK/PMK-1 plays protective role against AgNP-mediated toxicity, reduced viability and greater accumulation of 8OHdG was observed in AgNP-treated KD cells, and in pmk-1 mutant worms compared with their WT counterparts, respectively. Furthermore, dose-dependent alterations in hOGG1, hMTH1, and NDX-4 expression and enzyme activity, and survival in ndx-4 mutant worms occurred following AgNP exposure. Interestingly, the absence or depletion of p38 MAPK/PMK-1 caused impaired and additive effects in AgNP-induced ndx-4(ok1003); pmk-1(RNAi) mutant survival, and hOGG1 and NDX-4 expression and enzyme activity, which may lead to higher accumulation of 8OHdG. Together, the results indicate that p38 MAPK/PMK-1 plays an important protective role in AgNP-induced oxidative DNA damage-repair which is conserved from C. elegans to humans.
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Affiliation(s)
- Nivedita Chatterjee
- School of Environmental Engineering, Graduate School of Energy and Environmental system Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 130-743, Korea
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38
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Berger AH, Imielinski M, Duke F, Wala J, Kaplan N, Shi GX, Andres DA, Meyerson M. Oncogenic RIT1 mutations in lung adenocarcinoma. Oncogene 2014; 33:4418-23. [PMID: 24469055 PMCID: PMC4150988 DOI: 10.1038/onc.2013.581] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 11/25/2013] [Accepted: 12/03/2013] [Indexed: 12/27/2022]
Abstract
Lung adenocarcinoma is comprised of distinct mutational subtypes characterized by mutually exclusive oncogenic mutations in RTK/RAS pathway members KRAS, EGFR, BRAF and ERBB2, and translocations involving ALK, RET and ROS1. Identification of these oncogenic events has transformed the treatment of lung adenocarcinoma via application of therapies targeted toward specific genetic lesions in stratified patient populations. However, such mutations have been reported in only ∼55% of lung adenocarcinoma cases in the United States, suggesting other mechanisms of malignancy are involved in the remaining cases. Here we report somatic mutations in the small GTPase gene RIT1 in ∼2% of lung adenocarcinoma cases that cluster in a hotspot near the switch II domain of the protein. RIT1 switch II domain mutations are mutually exclusive with all other known lung adenocarcinoma driver mutations. Ectopic expression of mutated RIT1 induces cellular transformation in vitro and in vivo, which can be reversed by combined PI3K and MEK inhibition. These data identify RIT1 as a driver oncogene in a specific subset of lung adenocarcinomas and suggest PI3K and MEK inhibition as a potential therapeutic strategy in RIT1-mutated tumors.
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Affiliation(s)
- A H Berger
- 1] Cancer Program, The Broad Institute of Harvard and M.I.T., 7 Cambridge Center, Cambridge, MA, USA [2] Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA
| | - M Imielinski
- 1] Cancer Program, The Broad Institute of Harvard and M.I.T., 7 Cambridge Center, Cambridge, MA, USA [2] Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA [3] Department of Pathology, Massachusetts General Hospital, Boston, MA, USA [4] Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - F Duke
- Cancer Program, The Broad Institute of Harvard and M.I.T., 7 Cambridge Center, Cambridge, MA, USA
| | - J Wala
- 1] Cancer Program, The Broad Institute of Harvard and M.I.T., 7 Cambridge Center, Cambridge, MA, USA [2] Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA [3] Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - N Kaplan
- Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA
| | - G-X Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, USA
| | - D A Andres
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, USA
| | - M Meyerson
- 1] Cancer Program, The Broad Institute of Harvard and M.I.T., 7 Cambridge Center, Cambridge, MA, USA [2] Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA [3] Department of Pathology, Harvard Medical School, Boston, MA, USA
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Abstract
Redox agents have been historically considered pathological agents which can react with and damage many biological macromolecules including DNA, proteins, and lipids. However, a growing number of reports have suggested that mammalian cells can rapidly respond to ligand stimulation with a change in intracellular ROS thus indicating that the production of intracellular redox agents is tightly regulated and that they serve as intracellular signaling molecules being involved in a variety of cell signaling pathways. Numerous observations have suggested that some members of the Ras GTPase superfamily appear to regulate the production of redox agents and that oxidants can function as effector molecules for the small GTPases, thus contributing to their overall biological function. In addition, many of the Ras superfamily small GTPases have been shown to be redox sensitive, thanks to the presence of redox-sensitive sequences in their primary structure. The action of redox agents on these redox-sensitive GTPases is similar to that of guanine nucleotide exchange factors in that they perturb GTPase nucleotide-binding interactions that result in the enhancement of the guanine nucleotide exchange of small GTPases. Thus, Ras GTPases may act both as upstream regulators and downstream effectors of redox agents. Here we overview current understanding concerning the interplay between Ras GTPases and redox agents, also taking into account pathological implications of misregulation of this cross talk and highlighting the potentiality of these cellular pathways as new therapeutical targets for different pathologies.
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40
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Kappe C, Zhang Q, Holst JJ, Nyström T, Sjöholm Å. Evidence for paracrine/autocrine regulation of GLP-1-producing cells. Am J Physiol Cell Physiol 2013; 305:C1041-9. [DOI: 10.1152/ajpcell.00227.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Glucagon-like peptide-1 (GLP-1), secreted from gut L cells upon nutrient intake, forms the basis for novel drugs against type 2 diabetes (T2D). Secretion of GLP-1 has been suggested to be impaired in T2D and in conditions associated with hyperlipidemia and insulin resistance. Further, recent studies support lipotoxicity of GLP-1-producing cells in vitro. However, little is known about the regulation of L-cell viability/function, the effects of insulin signaling, or the potential effects of stable GLP-1 analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors. We determined effects of insulin as well as possible autocrine action of GLP-1 on viability/apoptosis of GLP-1-secreting cells in the presence/absence of palmitate, while also assessing direct effects on function. The studies were performed using the GLP-1-secreting cell line GLUTag, and palmitate was used to simulate hyperlipidemia. Our results show that palmitate induced production of reactive oxygen species and caspase-3 activity and reduced cell viability are significantly attenuated by preincubation with insulin/exendin-4. The indicated lipoprotective effect of insulin/exendin-4 was not detectable in the presence of the GLP-1 receptor (GLP-1R) antagonist exendin (9–39) and attenuated in response to pharmacological inhibition of exchange protein activated by cAMP (Epac) signaling, while protein kinase A inhibition had no significant effect. Insulin/exendin-4 also significantly stimulate acute and long-term GLP-1 secretion in the presence of glucose, suggesting novel beneficial effects of insulin signaling and GLP-1R activation on glycemia through enhanced mass of GLP-1-producing cells and enhanced GLP-1 secretion. In addition, the effects of insulin indicate that not only is GLP-1 important for insulin secretion but altered insulin signaling may contribute to an altered GLP-1 secretion.
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Affiliation(s)
- Camilla Kappe
- Karolinska Institutet, Department of Clinical Science and Education, Unit for Diabetes Research, Södersjukhuset, Stockholm, Sweden
| | - Qimin Zhang
- Karolinska Institutet, Department of Clinical Science and Education, Unit for Diabetes Research, Södersjukhuset, Stockholm, Sweden
| | - Jens J. Holst
- Department of Biomedical Sciences, Panum Institute, Copenhagen, Denmark; and
| | - Thomas Nyström
- Karolinska Institutet, Department of Clinical Science and Education, Unit for Diabetes Research, Södersjukhuset, Stockholm, Sweden
| | - Åke Sjöholm
- Karolinska Institutet, Department of Clinical Science and Education, Unit for Diabetes Research, Södersjukhuset, Stockholm, Sweden
- Department of Biochemistry and Molecular Biology, University of South Alabama, College of Medicine, Mobile, Alabama
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41
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Wang GB, Ni YL, Zhou XP, Zhang WF. The AKT/mTOR pathway mediates neuronal protective effects of erythropoietin in sepsis. Mol Cell Biochem 2013; 385:125-32. [PMID: 24057122 DOI: 10.1007/s11010-013-1821-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 09/13/2013] [Indexed: 12/14/2022]
Abstract
Sepsis is one of the most common causes of mortality in intensive care units. Although sepsis-associated encephalopathy (SAE) is reported to be a leading manifestation of sepsis, its pathogenesis remains to be elucidated. In this study, we investigated whether exogenous recombinant human erythropoietin (rhEPO) could protect brain from neuronal apoptosis in the model of SAE. We showed that application of rhEPO enhanced Bcl-2, decreased Bad in lipopolysaccharide treated neuronal cultures, and improved neuronal apoptosis in hippocampus of cecal ligation and peroration rats. We also found that rhEPO increased the expression of phosphorylated AKT, and the antiapoptotic role of rhEPO could be abolished by phosphoinositide 3-kinase (PI3K)/AKT inhibitor LY294002 or SH-5. In addition, systemic sepsis inhibited the hippocampal-phosphorylated mammalian target of rapamycin (mTOR) and p70S6K (downstream substrates of PKB/AKT signaling), which were restored by administration of exogenous rhEPO. Moreover, treatment with mTOR-signaling inhibitor rapamycin or transfection of mTOR siRNA reversed the neuronal protective effects of rhEPO. Finally, exogenous rhEPO rescued the emotional and spatial cognitive defects without any influence on locomotive activity. These results illustrated that exogenous rhEPO improves brain dysfunction by reducing neuronal apoptosis, and AKT/mTOR signaling is likely to be involved in this process. Application of rhEPO may serve as a potential therapy for the treatment of SAE.
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Affiliation(s)
- Guo-Bin Wang
- Department of Surgical Intensive Care Unit, The First Affiliated Hospital, Medical College, Zhejiang University, Qingchun Road 79, Hangzhou, 310003, People's Republic of China
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42
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Aoki Y, Niihori T, Banjo T, Okamoto N, Mizuno S, Kurosawa K, Ogata T, Takada F, Yano M, Ando T, Hoshika T, Barnett C, Ohashi H, Kawame H, Hasegawa T, Okutani T, Nagashima T, Hasegawa S, Funayama R, Nagashima T, Nakayama K, Inoue SI, Watanabe Y, Ogura T, Matsubara Y. Gain-of-function mutations in RIT1 cause Noonan syndrome, a RAS/MAPK pathway syndrome. Am J Hum Genet 2013; 93:173-80. [PMID: 23791108 DOI: 10.1016/j.ajhg.2013.05.021] [Citation(s) in RCA: 230] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/19/2013] [Accepted: 05/23/2013] [Indexed: 11/18/2022] Open
Abstract
RAS GTPases mediate a wide variety of cellular functions, including cell proliferation, survival, and differentiation. Recent studies have revealed that germline mutations and mosaicism for classical RAS mutations, including those in HRAS, KRAS, and NRAS, cause a wide spectrum of genetic disorders. These include Noonan syndrome and related disorders (RAS/mitogen-activated protein kinase [RAS/MAPK] pathway syndromes, or RASopathies), nevus sebaceous, and Schimmelpenning syndrome. In the present study, we identified a total of nine missense, nonsynonymous mutations in RIT1, encoding a member of the RAS subfamily, in 17 of 180 individuals (9%) with Noonan syndrome or a related condition but with no detectable mutations in known Noonan-related genes. Clinical manifestations in the RIT1-mutation-positive individuals are consistent with those of Noonan syndrome, which is characterized by distinctive facial features, short stature, and congenital heart defects. Seventy percent of mutation-positive individuals presented with hypertrophic cardiomyopathy; this frequency is high relative to the overall 20% incidence in individuals with Noonan syndrome. Luciferase assays in NIH 3T3 cells showed that five RIT1 alterations identified in children with Noonan syndrome enhanced ELK1 transactivation. The introduction of mRNAs of mutant RIT1 into 1-cell-stage zebrafish embryos was found to result in a significant increase of embryos with craniofacial abnormalities, incomplete looping, a hypoplastic chamber in the heart, and an elongated yolk sac. These results demonstrate that gain-of-function mutations in RIT1 cause Noonan syndrome and show a similar biological effect to mutations in other RASopathy-related genes.
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Affiliation(s)
- Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai 980-8574, Japan.
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Supanji, Shimomachi M, Hasan MZ, Kawaichi M, Oka C. HtrA1 is induced by oxidative stress and enhances cell senescence through p38 MAPK pathway. Exp Eye Res 2013; 112:79-92. [PMID: 23623979 DOI: 10.1016/j.exer.2013.04.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/28/2013] [Accepted: 04/15/2013] [Indexed: 01/10/2023]
Abstract
Genetic predisposition and senescence of retinal pigment epithelium induced by oxidative stress are major contributors to age-related macular degeneration (AMD). Single-nucleotide polymorphisms in HTRA1 are strongly linked to the onset of AMD. In this study, we examine the role of HtrA1 in premature senescence and cell death induced by oxidative stress. HtrA1 mRNA and protein were up-regulated during premature senescence induced by H2O2 in both mouse embryonic fibroblasts (MEFs) and ARPE-19 cells. Expression of the senescence markers p21(CIP1/WAF1) and p16(INK4a), and SA-β-galactosidase activity, were higher in HtrA1+/- MEFs than in HtrA1-/- MEFs. HtrA1+/+ and HtrA1+/- MEFs were more resistant than HtrA1-/- MEFs to H2O2-induced cell death. Activation of p38 MAPK by oxidative stress was quicker in HtrA1+/- MEFs than in HtrA1-/- MEFs. The effects of excess HtrA1 were examined by transient transfection of cells with HtrA1 expression vectors or by addition of recombinant proteins. Excess wild type HtrA1 accelerated premature senescence of MEFs and ARPE-19 cells, while the protease-inactive HtrA1 S328A did not. HtrA1-induced senescence was abrogated by inhibition of p38 MAPK. We conclude that HtrA1 is induced by oxidative stress and promotes premature cell senescence through p38 MAPK in a protease activity-dependent manner.
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Affiliation(s)
- Supanji
- Division of Gene Function in Animals, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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Cai W, Shi GX, Andres DA. Putting the Rit in cellular resistance: Rit, p38 MAPK and oxidative stress. Commun Integr Biol 2013; 6:e22297. [PMID: 23802035 PMCID: PMC3689566 DOI: 10.4161/cib.22297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cells mobilize diverse signaling pathways to protect against stress-mediated injury. Ras family GTPases play critical roles in this process, controlling the activation and integration of multiple regulatory cascades. p38 mitogen-activated protein kinase (MAPK) signaling serves as a critical fulcrum in this process, regulating networks that stimulate cellular apoptosis but also promote cell survival. However, this functional dichotomy is incompletely understood, particularly regulation of p38-dependent survival. Here, we discuss our recent evidence that the Rit GTPase associates with and is required for stress-mediated activation of a scaffolded p38-MK2-HSP27-Akt pro-survival signaling cascade. Drosophila lacking D-Ric, a Rit homologue, are susceptible to a variety of environmental stresses, while embryonic fibroblasts derived from Rit knockout mice display blunted stress-dependent signaling and decreased viability. Conversely, expression of constitutively active Rit triggers p38-Akt-dependent cell survival. Together, our studies establish Rit as the central regulator of an evolutionarily conserved, p38-dependent signaling cascade that functions as a critical survival mechanism in response to stress.
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Affiliation(s)
- Weikang Cai
- Department of Molecular and Cellular Biochemistry; College of Medicine; University of Kentucky; Lexington, KY USA
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Gómez-Seguí I, Makishima H, Jerez A, Yoshida K, Przychodzen B, Miyano S, Shiraishi Y, Husseinzadeh HD, Guinta K, Clemente M, Hosono N, McDevitt MA, Moliterno AR, Sekeres MA, Ogawa S, Maciejewski JP. Novel recurrent mutations in the RAS-like GTP-binding gene RIT1 in myeloid malignancies. Leukemia 2013; 27:1943-6. [PMID: 23765226 DOI: 10.1038/leu.2013.179] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Shi GX, Cai W, Andres DA. Rit subfamily small GTPases: regulators in neuronal differentiation and survival. Cell Signal 2013; 25:2060-8. [PMID: 23770287 DOI: 10.1016/j.cellsig.2013.06.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 06/04/2013] [Indexed: 02/07/2023]
Abstract
Ras family small GTPases serve as binary molecular switches to regulate a broad array of cellular signaling cascades, playing essential roles in a vast range of normal physiological processes, with dysregulation of numerous Ras-superfamily G-protein-dependent regulatory cascades underlying the development of human disease. However, the physiological function for many "orphan" Ras-related GTPases remain poorly characterized, including members of the Rit subfamily GTPases. Rit is the founding member of a novel branch of the Ras subfamily, sharing close homology with the neuronally expressed Rin and Drosophila Ric GTPases. Here, we highlight recent studies using transgenic and knockout animal models which have begun to elucidate the physiological roles for the Rit subfamily, including emerging roles in the regulation of neuronal morphology and cellular survival signaling, and discuss new genetic data implicating Rit and Rin signaling in disorders such as cancer, Parkinson's disease, autism, and schizophrenia.
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Affiliation(s)
- Geng-Xian Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, BBSRB, 741S. Limestone St., Lexington, KY 40536-0509, USA
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Kobayashi Y, Qi X, Chen G. MK2 Regulates Ras Oncogenesis through Stimulating ROS Production. Genes Cancer 2012; 3:521-30. [PMID: 23264852 DOI: 10.1177/1947601912462718] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 09/01/2012] [Indexed: 12/17/2022] Open
Abstract
Ras signals through both mitogenic and stress pathways and studies of Ras regulatory effects of stress pathways hold great promise to control Ras-dependent malignancies. Our previous work showed Ras activation of a stress kinase (MAPK-activated protein kinase 2 [MK2]), and here, we examine regulatory effects of MK2 on Ras oncogenesis. MK2 knockout was shown to increase Ras transformation in mouse embryonic fibroblasts (MEFs) in vitro and to enhance the resultant tumor growth in mice, indicating a tumor suppressor activity. In Ras-dependent and -independent human colon cancer, however, MK2-forced expression increases and MK2 depletion decreases the malignant growth, suggesting its oncogenic activity. The oncogenic activity of MK2 couples with its activation by both stress and mitogenic signals through extracellular signal-regulated kinase and p38α pathways, whereas its tumor-suppressing effect links to its stimulation only by stress downstream of p38α. Of interest, MK2 was shown to decrease intracellular levels of reactive oxygen species (ROS) in MEFs but increase its production in human colon cancer cells, and experiments with antioxidants revealed that ROS is required for Ras oncogenesis in both systems. These results indicate that MK2 can increase or decrease Ras oncogenesis dependent of its ROS regulatory activities.
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Affiliation(s)
- Yusuke Kobayashi
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
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Rit GTPase regulates a p38 MAPK-dependent neuronal survival pathway. Neurosci Lett 2012; 531:125-30. [PMID: 23123784 DOI: 10.1016/j.neulet.2012.10.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/12/2012] [Accepted: 10/22/2012] [Indexed: 11/24/2022]
Abstract
Rit, along with Rin and Drosophila Ric, comprises the Rit subfamily of Ras-related small GTPases. Although the cellular functions of many Ras family GTPases are well established, the physiological significance of Rit remains poorly understood. Loss of Rit sensitizes multiple mammalian cell lines and mouse embryonic fibroblasts (MEFs) derived from Rit(-/-) mice to oxidative stress-mediated apoptosis. However, whether Rit-mediated pro-survival signaling extends to other cell types, particularly neurons, is presently unknown. Here, to examine these issues we generated a transgenic mouse overexpressing constitutively active Rit (Rit(Q79L)) exclusively in neurons, under control of the Synapsin I promoter. Active Rit-expressing hippocampal neurons display a dramatic increase in oxidative stress resistance. Moreover, pharmacological inhibitor studies demonstrate that p38 MAPK, rather than a MEK/ERK signaling cascade, is required for Rit-mediated protection. Together, the present studies identify a critical role for the Rit-p38 MAPK signaling cascade in promoting hippocampal neuron survival following oxidative stress.
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Abstract
The molecular mechanisms governing the spontaneous recovery seen following brain injury remain elusive, but recent studies indicate that injury-induced stimulation of hippocampal neurogenesis contributes to the repair process. The therapeutic potential of endogenous neurogenesis is tempered by the demonstration that traumatic brain injury (TBI) results in the selective death of adult-born immature neurons, compromising the cell population poised to compensate for trauma-induced neuronal loss. Here, we identify the Ras-related GTPase, Rit, as a critical player in the survival of immature hippocampal neurons following brain injury. While Rit knock-out (Rit(-/-)) did not alter hippocampal development, hippocampal neural cultures derived from Rit(-/-) mice display increased cell death and blunted MAPK cascade activation in response to oxidative stress, without affecting BDNF-dependent signaling. When compared with wild-type hippocampal cultures, Rit loss rendered immature (Dcx(+)) neurons susceptible to oxidative damage, without altering the survival of neural progenitor (Nestin(+)) cells. Oxidative stress is a major contributor to neuronal cell death following brain injury. Consistent with the enhanced vulnerability of cultured Rit(-/-) immature neurons, Rit(-/-) mice exhibited a significantly greater loss of adult-born immature neurons within the dentate gyrus after TBI. In addition, post-TBI neuronal remodeling was blunted. Together, these data identify a new and unexpected role for Rit in injury-induced neurogenesis, functioning as a selective survival mechanism for immature hippocampal neurons within the subgranular zone of the dentate gyrus following TBI.
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Shi GX, Cai W, Andres DA. Rit-mediated stress resistance involves a p38-mitogen- and stress-activated protein kinase 1 (MSK1)-dependent cAMP response element-binding protein (CREB) activation cascade. J Biol Chem 2012; 287:39859-68. [PMID: 23038261 DOI: 10.1074/jbc.m112.384248] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The cAMP response element (CRE)-binding protein (CREB) is a key regulatory factor of gene transcription, and plays an essential role in development of the central nervous system and for neuroprotection. Multiple signaling pathways have been shown to contribute to the regulation of CREB-dependent transcription, including both ERK and p38 mitogen-activated protein (MAP) kinases cascades. Recent studies have identified the Ras-related small G-protein, Rit, as a central regulator of a p38-MK2-HSP27 signaling cascade that functions as a critical survival mechanism for cells adapting to stress. Here, we examine the contribution of Rit-p38 signaling to the control of stress-dependent gene transcription. Using a pheochromocytoma cell model, we find that a novel Rit-p38-MSK1/2 pathway plays a critical role in stress-mediated CREB activation. RNAi-mediated Rit silencing, or inhibition of p38 or MSK1/2 kinases, was found to disrupt stress-mediated CREB-dependent transcription, resulting in increased cell death. Furthermore, ectopic expression of active Rit stimulates CREB-Ser133 phosphorylation, induces expression of the anti-apoptotic Bcl-2 and Bcl(XL) proteins, and promotes cell survival. These data indicate that the Rit-p38-MSK1/2 signaling pathway may have an important role in the stress-dependent regulation of CREB-dependent gene expression.
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Affiliation(s)
- Geng-Xian Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536-0509, USA.
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