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Jiang N, Li W, Jiang S, Xie M, Liu R. Acetylation in pathogenesis: Revealing emerging mechanisms and therapeutic prospects. Biomed Pharmacother 2023; 167:115519. [PMID: 37729729 DOI: 10.1016/j.biopha.2023.115519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/22/2023] Open
Abstract
Protein acetylation modifications play a central and pivotal role in a myriad of biological processes, spanning cellular metabolism, proliferation, differentiation, apoptosis, and beyond, by effectively reshaping protein structure and function. The metabolic state of cells is intricately connected to epigenetic modifications, which in turn influence chromatin status and gene expression patterns. Notably, pathological alterations in protein acetylation modifications are frequently observed in diseases such as metabolic syndrome, cardiovascular disorders, and cancer. Such abnormalities can result in altered protein properties and loss of function, which are closely associated with developing and progressing related diseases. In recent years, the advancement of precision medicine has highlighted the potential value of protein acetylation in disease diagnosis, treatment, and prevention. This review includes provocative and thought-provoking papers outlining recent breakthroughs in acetylation modifications as they relate to cardiovascular disease, mitochondrial metabolic regulation, liver health, neurological health, obesity, diabetes, and cancer. Additionally, it covers the molecular mechanisms and research challenges in understanding the role of acetylation in disease regulation. By summarizing novel targets and prognostic markers for the treatment of related diseases, we aim to contribute to the field. Furthermore, we discuss current hot topics in acetylation research related to health regulation, including N4-acetylcytidine and liquid-liquid phase separation. The primary objective of this review is to provide insights into the functional diversity and underlying mechanisms by which acetylation regulates proteins in disease contexts.
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Affiliation(s)
- Nan Jiang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Wenyong Li
- School of Biology and Food Engineering, Fuyang Normal University, Fuyang, Anhui 236037, China
| | - Shuanglin Jiang
- School of Biology and Food Engineering, Fuyang Normal University, Fuyang, Anhui 236037, China
| | - Ming Xie
- North China Petroleum Bureau General Hospital, Renqiu 062550, China.
| | - Ran Liu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
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2
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Ding X, Chen Y, Guo C, Fu Y, Qin C, Zhu Q, Wang J, Zhang R, Tian H, Feng R, Liu H, Liang D, Wang G, Teng J, Li J, Tang B, Wang X. Mutations in ARHGEF15 cause autosomal dominant hereditary cerebral small vessel disease and osteoporotic fracture. Acta Neuropathol 2023; 145:681-705. [PMID: 36929019 DOI: 10.1007/s00401-023-02560-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/26/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023]
Abstract
Cerebral small vessel disease (CSVD) is a prominent cause of ischemic and hemorrhagic stroke and a leading cause of vascular dementia, affecting small penetrating vessels of the brain. Despite current advances in genetic susceptibility studies, challenges remain in defining the causative genes and the underlying pathophysiological mechanisms. Here, we reported that the ARHGEF15 gene was a causal gene linked to autosomal dominant inherited CSVD. We identified one heterozygous nonsynonymous mutation of the ARHGEF15 gene that cosegregated completely in two families with CSVD, and a heterozygous nonsynonymous mutation and a stop-gain mutation in two individuals with sporadic CSVD, respectively. Intriguingly, clinical imaging and pathological findings displayed severe osteoporosis and even osteoporotic fractures in all the ARHGEF15 mutation carriers. In vitro experiments indicated that ARHGEF15 mutations resulted in RhoA/ROCK2 inactivation-induced F-actin cytoskeleton disorganization in vascular smooth muscle cells and endothelial cells and osteoblast dysfunction by inhibiting the Wnt/β-catenin signaling pathway in osteoblast cells. Furthermore, Arhgef15-e(V368M)1 transgenic mice developed CSVD-like pathological and behavioral phenotypes, accompanied by severe osteoporosis. Taken together, our findings provide strong evidence that loss-of-function mutations of the ARHGEF15 gene cause CSVD accompanied by osteoporotic fracture.
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Affiliation(s)
- Xuebing Ding
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Yongkang Chen
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Cancan Guo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Yu Fu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Chi Qin
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Qingyong Zhu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Jiuqi Wang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Rui Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Haiyan Tian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Renyi Feng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Han Liu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Dongxiao Liang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Guanghui Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases &, Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Junfang Teng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China
| | - Jinchen Li
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China.
| | - Beisha Tang
- The First Affiliated Hospital, Multi-Omics Research Center for Brain Disorders, Hengyang Medical School, University of South China, Hengyang, China.
| | - Xuejing Wang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
- Institute of Parkinson and Movement Disorder, Zhengzhou University, Zhengzhou, China.
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Maddala R, Eldawy C, Bachman W, Soderblom EJ, Rao PV. Glypican-4 regulated actin cytoskeletal reorganization in glucocorticoid treated trabecular meshwork cells and involvement of Wnt/PCP signaling. J Cell Physiol 2023; 238:631-646. [PMID: 36727620 DOI: 10.1002/jcp.30953] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/30/2022] [Accepted: 01/10/2023] [Indexed: 02/03/2023]
Abstract
A common adverse response to the clinical use of glucocorticoids (GCs) is elevated intraocular pressure (IOP) which is a major risk factor for glaucoma. Elevated IOP arises due to impaired outflow of aqueous humor (AH) through the trabecular meshwork (TM). Although GC-induced changes in actin cytoskeletal dynamics, contractile characteristics, and cell adhesive interactions of TM cells are believed to influence AH outflow and IOP, the molecular mechanisms mediating changes in these cellular characteristics are poorly understood. Our studies focused on evaluating changes in the cytoskeletal and cytoskeletal-associated protein (cytoskeletome) profile of human TM cells treated with dexamethasone (Dex) using label-free mass spectrometric quantification, identified elevated levels of specific proteins known to regulate actin stress fiber formation, contraction, actin networks crosslinking, cell adhesion, and Wnt signaling, including LIMCH1, ArgBP2, CNN3, ITGBL1, CTGF, palladin, FAT1, DIAPH2, EPHA4, SIPA1L1, and GPC4. Several of these proteins colocalized with the actin cytoskeleton and underwent alterations in distribution profile in TM cells treated with Dex, and an inhibitor of Abl/Src kinases. Wnt/Planar Cell Polarity (PCP) signaling agonists-Wnt5a and 5b were detected prominently in the cytoskeletome fraction of TM cells, and studies using siRNA to suppress expression of glypican-4 (GPC4), a known modulator of the Wnt/PCP pathway revealed that GPC4 deficiency impairs Dex induced actin stress fiber formation, and activation of c-Jun N-terminal Kinase (JNK) and Rho kinase. Additionally, while Dex augmented, GPC4 deficiency suppressed the formation of actin stress fibers in TM cells in the presence of Dex and Wnt5a. Taken together, these results identify the GPC4-dependent Wnt/PCP signaling pathway as one of the crucial upstream regulators of Dex induced actin cytoskeletal reorganization and cell adhesion in TM cells, opening an opportunity to target the GPC4/Wnt/PCP pathway for treatment of ocular hypertension in glaucoma.
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Affiliation(s)
- Rupalatha Maddala
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Camelia Eldawy
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA
| | - William Bachman
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Erik J Soderblom
- Proteomics and Metabolomics Shared Resource, Duke University School of Medicine, Duke Center for Genomic and Computational Biology, Durham, North Carolina, USA
| | - Ponugoti V Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
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ARHGEF37 overexpression promotes extravasation and metastasis of hepatocellular carcinoma via directly activating Cdc42. J Exp Clin Cancer Res 2022; 41:230. [PMID: 35869555 PMCID: PMC9308268 DOI: 10.1186/s13046-022-02441-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/15/2022] [Indexed: 11/24/2022] Open
Abstract
Background The extravasation capability of hepatocellular carcinoma (HCC) cells plays a vital role in distant metastasis. However, the underlying mechanism of extravasation in HCC lung metastasis remains largely unclear. Methods The expression of ARHGEF37 in human HCC specimens and HCC cell lines was examined by quantitative RT-PCR, western blot, and immunohistochemistry (IHC) analyses. The biological roles and mechanisms of ARHGEF37/Cdc42 in promoting lung metastasis were investigated in vitro and in vivo using cell lines, patient samples, xenograft models. Results In the current study, we found that Rho guanine nucleotide exchange factor 37 (ARHGEF37) was upregulated in human HCC samples and was associated with tumor invasiveness, pulmonary metastasis and poor prognosis. Overexpressing ARHGEF37 significantly enhanced the extravasation and metastatic capability of HCC cells via facilitating tumor cell adhesion to endothelial cells and trans-endothelial migration. Mechanistically, ARHGEF37 directly interacted with and activated Cdc42 to promote the invadopodia formation in HCC cells, which consequently disrupted the interaction between endothelial cells and pericytes. Importantly, treatment with ZCL278, a specific inhibitor of Cdc42, dramatically inhibited the attachment of ARHGEF37-overexpressing HCC cells to endothelial cells, and the adherence and extravasation in the lung alveoli, resulting in suppression of lung metastasis in mice. Conclusion Our findings provide a new insight into the underlying mechanisms on the ARHGEF37 overexpression-mediated extravasation and pulmonary metastasis of HCC cells, and provided a potential therapeutic target for the prevention and treatment of HCC pulmonary metastasis. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-022-02441-y.
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A current overview of RhoA, RhoB, and RhoC functions in vascular biology and pathology. Biochem Pharmacol 2022; 206:115321. [DOI: 10.1016/j.bcp.2022.115321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/24/2022]
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Ganguly D, Thomas JA, Ali A, Kumar R. Mechanistic and therapeutic implications of EphA-4 receptor tyrosine kinase in the pathogenesis of Alzheimer's disease. Eur J Neurosci 2022; 56:5532-5546. [PMID: 34989046 DOI: 10.1111/ejn.15591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 12/14/2021] [Accepted: 12/28/2021] [Indexed: 12/14/2022]
Abstract
Erythropoietin-producing hepatoma (Eph) receptors belong to a family of tyrosine kinase receptors that plays a pivotal role in the development of the brain. Eph can be divided broadly into two groups, namely, EphA and EphB, comprising nine and five members, respectively. In recent years, the role of EphA-4 has become increasingly apparent in the onset of Alzheimer's disease (AD). Emerging evidence suggests that EphA-4 results in synaptic dysfunction, which in turn promotes the progression of AD. Moreover, pharmacological or genetic ablation of EphA-4 in the murine model of AD can alleviate the symptoms. The current review summarizes different pathways by which EphA-4 can influence pathogenesis. Since, majority of the studies had reported the protective effect of EphA-4 inhibition during AD, designing therapeutics based on decreasing its enzymatic activity might be necessary for introducing the novel interventions. Therefore, the review described peptide and nanobodies inhibitors of EphA-4 that exhibit the potential to modulate EphA-4 and could be used as lead molecules for the targeted therapy of AD.
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Affiliation(s)
- Devargya Ganguly
- Department of Biotechnology, GITAM Institute of Sciences, GITAM (Deemed to be) University, Vishakhapatnam, India
| | - Joshua Abby Thomas
- Department of Biotechnology, GITAM Institute of Sciences, GITAM (Deemed to be) University, Vishakhapatnam, India
| | - Abid Ali
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Rahul Kumar
- Department of Biotechnology, GITAM Institute of Sciences, GITAM (Deemed to be) University, Vishakhapatnam, India
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Vascular smooth muscle RhoA counteracts abdominal aortic aneurysm formation by modulating MAP4K4 activity. Commun Biol 2022; 5:1071. [PMID: 36207400 PMCID: PMC9546906 DOI: 10.1038/s42003-022-04042-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/27/2022] [Indexed: 11/08/2022] Open
Abstract
Whether a small GTPase RhoA plays a role in the pathology of abdominal aortic aneurysm (AAA) has not been determined. We show here that RhoA expression is reduced in human AAA lesions, compared with normal areas. Furthermore, incidence of AAA formation is increased in vascular smooth muscle cell (VSMC)-specific RhoA conditional knockout (cKO) mice. The contractility of the aortic rings and VSMCs from RhoA cKO mice is reduced, and expression of genes related to the VSMC contractility is attenuated by loss of RhoA. RhoA depletion activates the mitogen-activated protein (MAP) kinase signaling, including MAP4K4, in the aorta and VSMCs. Inhibition of MAP4K4 activity by DMX-5804 decreases AAA formation. Set, a binding protein to active RhoA, functions as an activator of MAP4K4 by sequestering PP2A, an inhibitor of MAP4K4, in the absence of RhoA. In conclusion, RhoA counteracts AAA formation through inhibition of MAP4K4 in cooperation with Set.
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8
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Wolff DW, Deng Z, Bianchi-Smiraglia A, Foley CE, Han Z, Wang X, Shen S, Rosenberg MM, Moparthy S, Yun DH, Chen J, Baker BK, Roll MV, Magiera AJ, Li J, Hurley E, Feltri ML, Cox AO, Lee J, Furdui CM, Liu L, Bshara W, LaConte LE, Kandel ES, Pasquale EB, Qu J, Hedstrom L, Nikiforov MA. Phosphorylation of guanosine monophosphate reductase triggers a GTP-dependent switch from pro- to anti-oncogenic function of EPHA4. Cell Chem Biol 2022; 29:970-984.e6. [PMID: 35148834 PMCID: PMC9620470 DOI: 10.1016/j.chembiol.2022.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 11/19/2021] [Accepted: 01/11/2022] [Indexed: 12/11/2022]
Abstract
Signal transduction pathways post-translationally regulating nucleotide metabolism remain largely unknown. Guanosine monophosphate reductase (GMPR) is a nucleotide metabolism enzyme that decreases GTP pools by converting GMP to IMP. We observed that phosphorylation of GMPR at Tyr267 is critical for its activity and found that this phosphorylation by ephrin receptor tyrosine kinase EPHA4 decreases GTP pools in cell protrusions and levels of GTP-bound RAC1. EPHs possess oncogenic and tumor-suppressor activities, although the mechanisms underlying switches between these two modes are poorly understood. We demonstrated that GMPR plays a key role in EPHA4-mediated RAC1 suppression. This supersedes GMPR-independent activation of RAC1 by EPHA4, resulting in a negative overall effect on melanoma cell invasion and tumorigenicity. Accordingly, EPHA4 levels increase during melanoma progression and inversely correlate with GMPR levels in individual melanoma tumors. Therefore, phosphorylation of GMPR at Tyr267 is a metabolic signal transduction switch controlling GTP biosynthesis and transformed phenotypes.
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Affiliation(s)
- David W. Wolff
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Zhiyong Deng
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Anna Bianchi-Smiraglia
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Colleen E. Foley
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Zhannan Han
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Xingyou Wang
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA
| | - Shichen Shen
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
| | | | - Sudha Moparthy
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Dong Hyun Yun
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Jialin Chen
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Brian K. Baker
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Matthew V. Roll
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Andrew J. Magiera
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Jun Li
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
| | - Edward Hurley
- Department of Biochemistry and Neurology, Hunter James Kelly Research Institute, University at Buffalo, Buffalo NY, USA
| | - Maria Laura Feltri
- Department of Biochemistry and Neurology, Hunter James Kelly Research Institute, University at Buffalo, Buffalo NY, USA
| | - Anderson O. Cox
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem NC, USA
| | - Jingyun Lee
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem NC, USA
| | - Cristina M. Furdui
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem NC, USA
| | - Liang Liu
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Wiam Bshara
- Department of Pathology, Roswell Park Comprehensive Cancer Center, Buffalo NY 14203, USA
| | - Leslie E.W. LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | - Eugene S. Kandel
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Elena B. Pasquale
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jun Qu
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA
| | - Lizbeth Hedstrom
- Department of Chemistry, Brandeis University, Waltham, MA 02453, USA,Department of Biology, Brandeis University, Waltham, MA 02453, USA
| | - Mikhail A. Nikiforov
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA,Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA,Department of Pathology, Duke University School of Medicine, Durham, NC 27710, USA,Corresponding author and lead contact: Mikhail A. Nikiforov,
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Luan Y, Ren KD, Luan Y, Chen X, Yang Y. Mitochondrial Dynamics: Pathogenesis and Therapeutic Targets of Vascular Diseases. Front Cardiovasc Med 2021; 8:770574. [PMID: 34938787 PMCID: PMC8685340 DOI: 10.3389/fcvm.2021.770574] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
Vascular diseases, particularly atherosclerosis, are associated with high morbidity and mortality. Endothelial cell (EC) or vascular smooth muscle cell (VSMC) dysfunction leads to blood vessel abnormalities, which cause a series of vascular diseases. The mitochondria are the core sites of cell energy metabolism and function in blood vessel development and vascular disease pathogenesis. Mitochondrial dynamics, including fusion and fission, affect a variety of physiological or pathological processes. Multiple studies have confirmed the influence of mitochondrial dynamics on vascular diseases. This review discusses the regulatory mechanisms of mitochondrial dynamics, the key proteins that mediate mitochondrial fusion and fission, and their potential effects on ECs and VSMCs. We demonstrated the possibility of mitochondrial dynamics as a potential target for the treatment of vascular diseases.
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Affiliation(s)
- Yi Luan
- Department of Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Kai-Di Ren
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou, China
| | - Ying Luan
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Xing Chen
- Department of Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yang Yang
- Department of Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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10
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Liu S, Lin Z. Vascular Smooth Muscle Cells Mechanosensitive Regulators and Vascular Remodeling. J Vasc Res 2021; 59:90-113. [PMID: 34937033 DOI: 10.1159/000519845] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/23/2021] [Indexed: 11/19/2022] Open
Abstract
Blood vessels are subjected to mechanical loads of pressure and flow, inducing smooth muscle circumferential and endothelial shear stresses. The perception and response of vascular tissue and living cells to these stresses and the microenvironment they are exposed to are critical to their function and survival. These mechanical stimuli not only cause morphological changes in cells and vessel walls but also can interfere with biochemical homeostasis, leading to vascular remodeling and dysfunction. However, the mechanisms underlying how these stimuli affect tissue and cellular function, including mechanical stimulation-induced biochemical signaling and mechanical transduction that relies on cytoskeletal integrity, are unclear. This review focuses on signaling pathways that regulate multiple biochemical processes in vascular mesangial smooth muscle cells in response to circumferential stress and are involved in mechanosensitive regulatory molecules in response to mechanotransduction, including ion channels, membrane receptors, integrins, cytoskeletal proteins, nuclear structures, and cascades. Mechanoactivation of these signaling pathways is closely associated with vascular remodeling in physiological or pathophysiological states.
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Affiliation(s)
- Shangmin Liu
- Ji Hua Institute of Biomedical Engineering Technology, Ji Hua Laboratory, Foshan, China, .,Medical Research Center, Guangdong Academy of Medical Sciences, Guangdong General Hospital, Guangzhou, China,
| | - Zhanyi Lin
- Ji Hua Institute of Biomedical Engineering Technology, Ji Hua Laboratory, Foshan, China.,Institute of Geriatric Medicine, Guangdong Academy of Medical Sciences, Guangdong General Hospital, Guangzhou, China
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11
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EphA2 signaling within integrin adhesions regulates fibrillar adhesion elongation and fibronectin deposition. Matrix Biol 2021; 103-104:1-21. [PMID: 34537369 DOI: 10.1016/j.matbio.2021.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 12/28/2022]
Abstract
The multifunctional glycoprotein fibronectin influences several crucial cellular processes and contributes to multiple pathologies. While a link exists between fibronectin-associated pathologies and the receptor tyrosine kinase EphA2, the mechanism by which EphA2 promotes fibronectin matrix remodeling remains unknown. We previously demonstrated that EphA2 deletion reduces smooth muscle fibronectin deposition and blunts fibronectin deposition in atherosclerosis without influencing fibronectin expression. We now show that EphA2 expression is required for contractility-dependent elongation of tensin- and α5β1 integrin-rich fibrillar adhesions that drive fibronectin fibrillogenesis. Mechanistically, EphA2 localizes to integrin adhesions where focal adhesion kinase mediates ligand-independent Y772 phosphorylation, and mutation of this site significantly blunts fibrillar adhesion length. EphA2 deficiency decreases smooth muscle cell contractility by enhancing p190RhoGAP activation and reducing RhoA activity, whereas stimulating RhoA signaling in EphA2 deficient cells rescues fibrillar adhesion elongation. Together, these data identify EphA2 as a novel regulator of fibrillar adhesion elongation and provide the first data identifying a role for EphA2 signaling in integrin adhesions.
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12
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Binamé F, Pham-Van LD, Bagnard D. Manipulating oligodendrocyte intrinsic regeneration mechanism to promote remyelination. Cell Mol Life Sci 2021; 78:5257-5273. [PMID: 34019104 PMCID: PMC11073109 DOI: 10.1007/s00018-021-03852-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/14/2021] [Accepted: 05/08/2021] [Indexed: 02/06/2023]
Abstract
In demyelinated lesions, astrocytes, activated microglia and infiltrating macrophages secrete several factors regulating oligodendrocyte precursor cells' behaviour. What appears to be the initiation of an intrinsic mechanism of myelin repair is only leading to partial recovery and inefficient remyelination, a process worsening over the course of the disease. This failure is largely due to the concomitant accumulation of inhibitory cues in and around the lesion sites opposing to growth promoting factors. Here starts a complex game of interactions between the signalling pathways controlling oligodendrocytes migration or differentiation. Receptors of positive or negative cues are modulating Ras, PI3K or RhoGTPases pathways acting on oligodendrocyte cytoskeleton remodelling. From the description of this intricate signalling network, this review addresses the extent to which the modulation of the global response to inhibitory cues may pave the route towards novel therapeutic approaches for myelin repair.
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Affiliation(s)
- Fabien Binamé
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France
| | - Lucas D Pham-Van
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France
| | - Dominique Bagnard
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France.
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13
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Dhagia V, Kitagawa A, Jacob C, Zheng C, D'Alessandro A, Edwards JG, Rocic P, Gupte R, Gupte SA. G6PD activity contributes to the regulation of histone acetylation and gene expression in smooth muscle cells and to the pathogenesis of vascular diseases. Am J Physiol Heart Circ Physiol 2021; 320:H999-H1016. [PMID: 33416454 PMCID: PMC7988761 DOI: 10.1152/ajpheart.00488.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/18/2020] [Accepted: 01/04/2021] [Indexed: 02/05/2023]
Abstract
We aimed to determine 1) the mechanism(s) that enables glucose-6-phosphate dehydrogenase (G6PD) to regulate serum response factor (SRF)- and myocardin (MYOCD)-driven smooth muscle cell (SMC)-restricted gene expression, a process that aids in the differentiation of SMCs, and 2) whether G6PD-mediated metabolic reprogramming contributes to the pathogenesis of vascular diseases in metabolic syndrome (MetS). Inhibition of G6PD activity increased (>30%) expression of SMC-restricted genes and concurrently decreased (40%) the growth of human and rat SMCs ex vivo. Expression of SMC-restricted genes decreased (>100-fold) across successive passages in primary cultures of SMCs isolated from mouse aorta. G6PD inhibition increased Myh11 (47%) while decreasing (>50%) Sca-1, a stem cell marker, in cells passaged seven times. Similarly, CRISPR-Cas9-mediated expression of the loss-of-function Mediterranean variant of G6PD (S188F; G6PDS188F) in rats promoted transcription of SMC-restricted genes. G6PD knockdown or inhibition decreased (48.5%) histone deacetylase (HDAC) activity, enriched (by 3-fold) H3K27ac on the Myocd promoter, and increased Myocd and Myh11 expression. Interestingly, G6PD activity was significantly higher in aortas from JCR rats with MetS than control Sprague-Dawley (SD) rats. Treating JCR rats with epiandrosterone (30 mg/kg/day), a G6PD inhibitor, increased expression of SMC-restricted genes, suppressed Serpine1 and Epha4, and reduced blood pressure. Moreover, feeding SD control (littermates) and G6PDS188F rats a high-fat diet for 4 mo increased Serpine1 and Epha4 expression and mean arterial pressure in SD but not G6PDS188F rats. Our findings demonstrate that G6PD downregulates transcription of SMC-restricted genes through HDAC-dependent deacetylation and potentially augments the severity of vascular diseases associated with MetS.NEW & NOTEWORTHY This study gives detailed mechanistic insight about the regulation of smooth muscle cell (SMC) phenotype by metabolic reprogramming and glucose-6-phosphate dehydrogenase (G6PD) in diabetes and metabolic syndrome. We demonstrate that G6PD controls the chromatin modifications by regulating histone deacetylase (HDAC) activity, which deacetylates histone 3-lysine 9 and 27. Notably, inhibition of G6PD decreases HDAC activity and enriches H3K27ac on myocardin gene promoter to enhance the expression of SMC-restricted genes. Also, we demonstrate for the first time that G6PD inhibitor treatment accentuates metabolic and transcriptomic reprogramming to reduce neointimal formation in coronary artery and large artery elastance in metabolic syndrome rats.
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MESH Headings
- Acetylation
- Animals
- Cell Line
- Disease Models, Animal
- Female
- Gene Expression Regulation
- Glucosephosphate Dehydrogenase/genetics
- Glucosephosphate Dehydrogenase/metabolism
- Hemodynamics
- Histones/metabolism
- Humans
- Male
- Metabolic Syndrome/enzymology
- Metabolic Syndrome/genetics
- Metabolic Syndrome/pathology
- Metabolic Syndrome/physiopathology
- Mice, Transgenic
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Mutation
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Myosin Heavy Chains/genetics
- Myosin Heavy Chains/metabolism
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Protein Processing, Post-Translational
- Rats, Sprague-Dawley
- Serum Response Factor/genetics
- Serum Response Factor/metabolism
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Vascular Remodeling
- Rats
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Affiliation(s)
- Vidhi Dhagia
- Department of Pharmacology, New York Medical College, Valhalla, New York
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Atsushi Kitagawa
- Department of Pharmacology, New York Medical College, Valhalla, New York
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Christina Jacob
- Department of Pharmacology, New York Medical College, Valhalla, New York
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Connie Zheng
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - John G Edwards
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Petra Rocic
- Department of Pharmacology, New York Medical College, Valhalla, New York
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Rakhee Gupte
- Raadysan Biotech., Incorporated, Fishkill, New York
| | - Sachin A Gupte
- Department of Pharmacology, New York Medical College, Valhalla, New York
- Department of Physiology, New York Medical College, Valhalla, New York
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14
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Stiffel VM, Thomas A, Rundle CH, Sheng MHC, Lau KHW. The EphA4 Signaling is Anti-catabolic in Synoviocytes but Pro-anabolic in Articular Chondrocytes. Calcif Tissue Int 2020; 107:576-592. [PMID: 32816052 PMCID: PMC7606366 DOI: 10.1007/s00223-020-00747-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/06/2020] [Indexed: 12/31/2022]
Abstract
The expression and activation of EphA4 in the various cell types in a knee joint was upregulated upon an intraarticular injury. To determine if EphA4 signaling plays a role in osteoarthritis, we determined whether deficient EphA4 expression (in EphA4 knockout mice) or upregulation of the EphA4 signaling (with the EfnA4-fc treatment) would alter cellular functions of synoviocytes and articular chondrocytes. In synoviocytes, deficient EphA4 expression enhanced, whereas activation of the EphA4 signaling reduced, expression and secretion of key inflammatory cytokines and matrix metalloproteases. Conversely, in articular chondrocytes, activation of the EphA4 signaling upregulated, while deficient EphA4 expression reduced, expression levels of chondrogenic genes (e.g., aggrecan, lubricin, type-2 collagen, and Sox9). EfnA4-fc treatment in wildtype, but not EphA4-deficient, articular chondrocytes promoted the formation and activity of acidic proteoglycan-producing colonies. Activation of the EphA4 signaling in articular chondrocytes upregulated Rac1/2 and downregulated RhoA via enhancing Vav1 and reducing Ephexin1 activation, respectively. However, activation of the EphA4 signaling in synoviocytes suppressed the Vav/Rac signaling while upregulated the Ephexin/Rho signaling. In summary, the EphA4 signaling in synoviocytes is largely of anti-catabolic nature through suppression of the expression of inflammatory cytokines and matrix proteases, but in articular chondrocytes the signaling is pro-anabolic in that it promotes the biosynthesis of articular cartilage. The contrasting action of the EphA4 signaling in synoviocytes as opposing to articular chondrocytes may in part be mediated through the opposite differential effects of the EphA4 signaling on the Vav/Rac signaling and Ephexin/Rho signaling in the two skeletal cell types.
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Affiliation(s)
- Virginia M Stiffel
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial V.A. Medical Center, 11201 Benton Street, Loma Linda, CA, 92357, USA
| | - Alexander Thomas
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial V.A. Medical Center, 11201 Benton Street, Loma Linda, CA, 92357, USA
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - Charles H Rundle
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial V.A. Medical Center, 11201 Benton Street, Loma Linda, CA, 92357, USA
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - Matilda H-C Sheng
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial V.A. Medical Center, 11201 Benton Street, Loma Linda, CA, 92357, USA
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - Kin-Hing William Lau
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial V.A. Medical Center, 11201 Benton Street, Loma Linda, CA, 92357, USA.
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA.
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15
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Baudet S, Bécret J, Nicol X. Approaches to Manipulate Ephrin-A:EphA Forward Signaling Pathway. Pharmaceuticals (Basel) 2020; 13:ph13070140. [PMID: 32629797 PMCID: PMC7407804 DOI: 10.3390/ph13070140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/19/2020] [Accepted: 06/28/2020] [Indexed: 02/07/2023] Open
Abstract
Erythropoietin-producing hepatocellular carcinoma A (EphA) receptors and their ephrin-A ligands are key players of developmental events shaping the mature organism. Their expression is mostly restricted to stem cell niches in adults but is reactivated in pathological conditions including lesions in the heart, lung, or nervous system. They are also often misregulated in tumors. A wide range of molecular tools enabling the manipulation of the ephrin-A:EphA system are available, ranging from small molecules to peptides and genetically-encoded strategies. Their mechanism is either direct, targeting EphA receptors, or indirect through the modification of intracellular downstream pathways. Approaches enabling manipulation of ephrin-A:EphA forward signaling for the dissection of its signaling cascade, the investigation of its physiological roles or the development of therapeutic strategies are summarized here.
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16
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Humphries BA, Wang Z, Yang C. MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis. Cancers (Basel) 2020; 12:E1092. [PMID: 32353968 PMCID: PMC7281527 DOI: 10.3390/cancers12051092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/24/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023] Open
Abstract
The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.
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Affiliation(s)
- Brock A. Humphries
- Center for Molecular Imaging, Department of Radiology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Zhishan Wang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| | - Chengfeng Yang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
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17
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Abstract
The Na,K-ATPase is an enzyme essential for ion homeostasis in all cells. Over the last decades, it has been well-established that in addition to the transport of Na+/K+ over the cell membrane, the Na,K-ATPase acts as a receptor transducing humoral signals intracellularly. It has been suggested that ouabain-like compounds serve as endogenous modulators of this Na,K-ATPase signal transduction. The molecular mechanisms underlying Na,K-ATPase signaling are complicated and suggest the confluence of divergent biological pathways. This review discusses recent updates on the Na,K-ATPase signaling pathways characterized or suggested in vascular smooth muscle cells. The conventional view on this signaling is based on a microdomain structure where the Na,K-ATPase controls the Na,Ca-exchanger activity via modulation of intracellular Na+ in the spatially restricted submembrane space. This, in turn, affects intracellular Ca2+ and Ca2+ load in the sarcoplasmic reticulum leading to modulation of contractility as well as gene expression. An ion-transport-independent signal transduction from the Na,K-ATPase is based on molecular interactions. This was primarily characterized in other cell types but recently also demonstrated in vascular smooth muscles. The downstream signaling from the Na,K-ATPase includes Src and phosphatidylinositol-4,5-bisphosphate 3 kinase signaling pathways and generation of reactive oxygen species. Moreover, in vascular smooth muscle cells the interaction between the Na,K-ATPase and proteins responsible for Ca2+ homeostasis, e.g., phospholipase C and inositol triphosphate receptors, contributes to an integration of the signaling pathways. Recent update on the Na,K-ATPase dependent intracellular signaling and the significance for physiological functions and pathophysiological changes are discussed in this review.
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18
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Emerging Roles of Ephexins in Physiology and Disease. Cells 2019; 8:cells8020087. [PMID: 30682817 PMCID: PMC6406967 DOI: 10.3390/cells8020087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/20/2019] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
Dbl (B-cell lymphoma)-related guanine nucleotide exchange factors (GEFs), the largest family of GEFs, are directly responsible for the activation of Rho family GTPases and essential for a number of cellular events such as proliferation, differentiation and movement. The members of the Ephexin (Eph-interacting exchange protein) family, a subgroup of Dbl GEFs, initially were named for their interaction with Eph receptors and sequence homology with Ephexin1. Although the first Ephexin was identified about two decades ago, their functions in physiological and pathological contexts and regulatory mechanisms remained elusive until recently. Ephexins are now considered as GEFs that can activate Rho GTPases such as RhoA, Rac, Cdc42, and RhoG. Moreover, Ephexins have been shown to have pivotal roles in neural development, tumorigenesis, and efferocytosis. In this review, we discuss the known and proposed functions of Ephexins in physiological and pathological contexts, as well as their regulatory mechanisms.
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19
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Kim K, Lee J, Moon H, Lee SA, Kim D, Yang S, Lee DH, Lee G, Park D. The Intermolecular Interaction of Ephexin4 Leads to Autoinhibition by Impeding Binding of RhoG. Cells 2018; 7:cells7110211. [PMID: 30445756 PMCID: PMC6262623 DOI: 10.3390/cells7110211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 12/14/2022] Open
Abstract
Ephexin4 is a guanine nucleotide-exchange factor (GEF) for RhoG and is involved in various RhoG-related cellular processes such as phagocytosis of apoptotic cells and migration of cancer cells. Ephexin4 forms an oligomer via an intermolecular interaction, and its GEF activity is increased in the presence of Elmo, an Ephexin4-interacting protein. However, it is uncertain if and how Ephexin4 is autoinhibited. Here, using an Ephexin4 mutant that abrogated the intermolecular interaction, we report that this interaction impeded binding of RhoG to Ephexin4 and thus inhibited RhoG activation. Mutation of the glutamate residue at position 295, which is a highly conserved residue located in the region of Ephexin4 required for the intermolecular interaction, to alanine (Ephexin4E295A) disrupted the intermolecular interaction and increased binding of RhoG, resulting in augmented RhoG activation. In addition, phagocytosis of apoptotic cells and formation of membrane ruffles were increased more by expression of Ephexin4E295A than by expression of wild-type Ephexin4. Taken together, our data suggest that Ephexin4 is autoinhibited through its intermolecular interaction, which impedes binding of RhoG.
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Affiliation(s)
- Kwanhyeong Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
- Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Korea.
| | - Juyeon Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
- Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Korea.
| | - Hyunji Moon
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
- Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Korea.
| | - Sang-Ah Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
| | - Deokhwan Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
- Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Korea.
| | - Susumin Yang
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
| | - Dae-Hee Lee
- Department of Oncology, College of Medicine, Korea University, Seoul 08308, Korea.
| | - Gwangrog Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
| | - Daeho Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
- Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Korea.
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20
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Finney AC, Orr AW. Guidance Molecules in Vascular Smooth Muscle. Front Physiol 2018; 9:1311. [PMID: 30283356 PMCID: PMC6157320 DOI: 10.3389/fphys.2018.01311] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Several highly conserved families of guidance molecules, including ephrins, Semaphorins, Netrins, and Slits, play conserved and distinct roles in tissue remodeling during tissue patterning and disease pathogenesis. Primarily, these guidance molecules function as either secreted or surface-bound ligands that interact with their receptors to activate a variety of downstream effects, including cell contractility, migration, adhesion, proliferation, and inflammation. Vascular smooth muscle cells, contractile cells comprising the medial layer of the vessel wall and deriving from the mural population, regulate vascular tone and blood pressure. While capillaries lack a medial layer of vascular smooth muscle, mural-derived pericytes contribute similarly to capillary tone to regulate blood flow in various tissues. Furthermore, pericyte coverage is critical in vascular development, as perturbations disrupt vascular permeability and viability. During cardiovascular disease, smooth muscle cells play a more dynamic role in which suppression of contractile markers, enhanced proliferation, and migration lead to the progression of aberrant vascular remodeling. Since many types of guidance molecules are expressed in vascular smooth muscle and pericytes, these may contribute to blood vessel formation and aberrant remodeling during vascular disease. While vascular development is a large focus of the existing literature, studies emerged to address post-developmental roles for guidance molecules in pathology and are of interest as novel therapeutic targets. In this review, we will discuss the roles of guidance molecules in vascular smooth muscle and pericyte function in development and disease.
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Affiliation(s)
- Alexandra Christine Finney
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
| | - Anthony Wayne Orr
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Pathology and Translational Medicine, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
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Kim M, Yoo HJ, Kim M, Kim J, Baek SH, Song M, Lee JH. EPHA6 rs4857055 C > T polymorphism associates with hypertension through triglyceride and LDL particle size in the Korean population. Lipids Health Dis 2017; 16:230. [PMID: 29208002 PMCID: PMC5718072 DOI: 10.1186/s12944-017-0620-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 11/22/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Erythropoietin-producing human hepatocellular (Eph) receptors might contribute to the development of atherosclerosis. A genome-wide association study indicated that the Eph receptor A6 gene (EPHA6) associated with at least 1 blood pressure (BP) phenotype. The objective of the present study was to determine whether EPHA6 is a novel candidate gene for hypertension in a Korean population. METHODS A total 2146 study participants with normotension and hypertension were included. Genotype data were obtained using a Korean Chip. To assess the association between single-nucleotide polymorphisms (SNPs) and BP, we performed a linear regression analysis, which showed that rs4850755 in the EPHA6 gene was the SNP most highly associated with both systolic and diastolic BP. RESULTS The presence of the TT genotype of the EPHA6 rs4857055 C > T SNP was associated with a higher risk of hypertension after adjusting for age, sex, body mass index (BMI), smoking, and drinking [odds ratio 1.533, P = 0.001]. In the control group, significant associations were observed between systolic BP and the rs4857055 polymorphism and between diastolic BP and the rs4857055 polymorphism. In the hypertension group, a significant association was observed between systolic BP and the rs4857055 polymorphism. In the hypertension group, subjects with the TT genotype showed significantly higher systolic BP than CC subjects. Additionally, in the hypertension group, TT carriers showed a higher tendency of serum triglyceride (P = 0.069) and significantly higher apolipoprotein B (P = 0.015) and smaller low-density lipoprotein (LDL) particle size (P < 0.001) than either TC or CC subjects. CONCLUSIONS These results could suggest that the EPHA6 rs4857055 C > T SNP is a novel candidate gene for hypertension in the Korean population. Additionally, the TT genotype could be associated with hypertriglyceridemia and small LDL particle size in hypertension.
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Affiliation(s)
- Minjoo Kim
- Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, 03722, Korea
| | - Hye Jin Yoo
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, 03722, Korea
| | - Minkyung Kim
- Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, 03722, Korea
| | - Jiyoo Kim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, 03722, Korea.,National Leading Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, 03722, Korea
| | - Seung Han Baek
- Institute of Convergence Technology, Yonsei University, Seoul, 03722, Korea
| | - Min Song
- Department of Library and Information Science, Yonsei University, Seoul, 03722, Korea
| | - Jong Ho Lee
- Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, 03722, Korea. .,Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, 03722, Korea. .,National Leading Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, 03722, Korea.
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22
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Hachim IY, Villatoro M, Canaff L, Hachim MY, Boudreault J, Haiub H, Ali S, Lebrun JJ. Transforming Growth Factor-beta Regulation of Ephrin Type-A Receptor 4 Signaling in Breast Cancer Cellular Migration. Sci Rep 2017; 7:14976. [PMID: 29101386 PMCID: PMC5670207 DOI: 10.1038/s41598-017-14549-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 10/11/2017] [Indexed: 12/16/2022] Open
Abstract
Breast cancer consists of a range of tumor subtypes with different clinical characteristics, disease prognosis, and treatment-response. Luminal breast cancer has the best prognosis while basal-like breast cancer (BLBC) represents the worst subtype. Transforming growth factor-beta (TGFβ) plays a prominent role in stimulating the migration and invasion of malignant breast cancer cells contributing to tumor progression. In this study, we identified the Ephrin type-A receptor 4 (EPHA4) as a novel target of TGFβ in breast cancer. Moreover, we show that TGFβ induction of EPHA4 gene expression is specific to basal-like tumors and is required for TGFβ-mediated cell migration. We further addressed the mechanism and found EPHA4 to be required for TGFβ-mediated cell migration in breast cancer through TGFβ-induced short term and long term activation of RhoGTPases. Finally, our data revealed a strong association between high EPHA4 expression and advanced tumor stage, aggressive BLBC molecular subtype and poor prognosis. Importantly, we found significant co-expression of EPHA4 and the TGFβ receptor type-2 (TGFβR2) in breast cancer subtypes associated with increased tumor relapse and drug resistance. Together, this study highlight the important role of the TGFβ/EPHA4 signaling axis in mediating tumor aggressiveness and poor patient survival in human breast cancer.
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Affiliation(s)
- Ibrahim Y. Hachim
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Manuel Villatoro
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Lucie Canaff
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Mahmood Y. Hachim
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada ,grid.412789.10000 0004 4686 5317Sharjah Institute for Medical Research, University of, Sharjah, UAE
| | - Julien Boudreault
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Halema Haiub
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Suhad Ali
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
| | - Jean-Jacques Lebrun
- 0000 0000 9064 4811grid.63984.30Department of Medicine, McGill University Health Center, Cancer Research Program, Montreal, QC H4A 3J1 Canada
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MacKay CE, Shaifta Y, Snetkov VV, Francois AA, Ward JPT, Knock GA. ROS-dependent activation of RhoA/Rho-kinase in pulmonary artery: Role of Src-family kinases and ARHGEF1. Free Radic Biol Med 2017; 110:316-331. [PMID: 28673614 PMCID: PMC5542024 DOI: 10.1016/j.freeradbiomed.2017.06.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 06/12/2017] [Accepted: 06/29/2017] [Indexed: 12/11/2022]
Abstract
The role of reactive oxygen species (ROS) in smooth muscle contraction is poorly understood. We hypothesised that G-protein coupled receptor (GPCR) activation and hypoxia induce Rho-kinase activity and contraction in rat intra-pulmonary artery (IPA) via stimulation of ROS production and subsequent Src-family kinase (SrcFK) activation. The T-type prostanoid receptor agonist U46619 induced ROS production in pulmonary artery smooth muscle cells (PASMC). U46619 also induced c-Src cysteine oxidation, SrcFK auto-phosphorylation, MYPT-1 and MLC20 phosphorylation and contraction in IPA, and all these responses were inhibited by antioxidants (ebselen, Tempol). Contraction and SrcFK/MYPT-1/MLC20 phosphorylations were also inhibited by combined superoxide dismutase and catalase, or by the SrcFK antagonist PP2, while contraction and MYPT-1/MLC20 phosphorylations were inhibited by the Rho guanine nucleotide exchange factor (RhoGEF) inhibitor Y16. H2O2 and the superoxide-generating quinoledione LY83583 both induced c-Src oxidation, SrcFK auto-phosphorylation and contraction in IPA. LY83583 and H2O2-induced contractions were inhibited by PP2, while LY83583-induced contraction was also inhibited by antioxidants and Y16. SrcFK auto-phosphorylation and MYPT-1/MLC20 phosphorylation was also induced by hypoxia in IPA and this was blocked by mitochondrial inhibitors rotenone and myxothiazol. In live PASMC, sub-cellular translocation of RhoA and the RhoGEF ARHGEF1 was triggered by both U46619 and LY83583 and this translocation was blocked by antioxidants and PP2. RhoA translocation was also inhibited by an ARHGEF1 siRNA. U46619 enhanced ROS-dependent co-immunoprecipitation of ARHGEF1 with c-Src. Our results demonstrate a link between GPCR-induced cytosolic ROS or hypoxia-induced mitochondrial ROS and SrcFK activity, Rho-kinase activity and contraction. ROS and SrcFK activate RhoA via ARHGEF1.
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Affiliation(s)
- Charles E MacKay
- Asthma, Allergy & Lung Biology, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Yasin Shaifta
- Asthma, Allergy & Lung Biology, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Vladimir V Snetkov
- Asthma, Allergy & Lung Biology, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Asvi A Francois
- Cardiovascular Division, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Jeremy P T Ward
- Asthma, Allergy & Lung Biology, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Greg A Knock
- Asthma, Allergy & Lung Biology, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.
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Tosato G. Ephrin ligands and Eph receptors contribution to hematopoiesis. Cell Mol Life Sci 2017; 74:3377-3394. [PMID: 28589441 PMCID: PMC11107787 DOI: 10.1007/s00018-017-2566-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/12/2017] [Accepted: 06/01/2017] [Indexed: 12/12/2022]
Abstract
Hematopoietic stem and progenitor cells reside predominantly in the bone marrow. They supply billions of mature blood cells every day during life through maturation into multilineage progenitors and self-renewal. Newly produced mature cells serve to replenish the pool of circulating blood cells at the end of their life-span. These mature blood cells and a few hematopoietic progenitors normally exit the bone marrow through the sinusoidal vessels, a specialized venous vascular system that spreads throughout the bone marrow. Many signals regulate the coordinated mobilization of hematopoietic cells from the bone marrow to the circulation. In this review, we present recent advances on hematopoiesis and hematopoietic cell mobilization with a focus on the role of Ephrin ligands and their Eph receptors. These constitute a large family of transmembrane ligands and receptors that play critical roles in development and postnatally. New insights point to distinct roles of ephrin and Eph in different aspects of hematopoiesis.
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Affiliation(s)
- Giovanna Tosato
- Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 4124, Bethesda, MD, 20892, USA.
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25
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Kim K, Lee J, Lee SA, Moon H, Park B, Kim D, Joo YE, Park D. Intermolecular steric inhibition of Ephexin4 is relieved by Elmo1. Sci Rep 2017; 7:4404. [PMID: 28667327 PMCID: PMC5493634 DOI: 10.1038/s41598-017-04810-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/19/2017] [Indexed: 11/09/2022] Open
Abstract
Ephexin4, a guanine nucleotide-exchange factor for RhoG, promotes engulfment of apoptotic cells and cancer cell migration in a RhoG-dependent manner, which is synergistically augmented by Elmo1, an Ephexin4-interacting protein. However, the underlying molecular mechanism remains elusive. Here, we report a mechanism by which Elmo1 cooperates with Ephexin4 to activate RhoG. We found that Ephexin4 activity was increased by elimination of its SH3 domain which intermolecularly interacts with the N20 region of Ephexin4. This interaction prevented RhoG from binding to Ephexin4 and thus inhibited RhoG activation. Moreover, we also found that Elmo1 associated with the SH3 domain as well as the N20 region and competed with the SH3 domain for binding to the N20 region, interrupting the interaction of the SH3 domain with the N20 region and thereby promoting RhoG binding to Ephexin4. In addition, the activity of Ephexin4 lacking the SH3 domain was comparable to that of Ephexin4 with Elmo1. Taken together, the data suggest that Elmo1 relieves the steric hindrance of Ephexin4 generated by the intermolecular interaction of the SH3 domain and makes Ephexin4 more accessible to RhoG.
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Affiliation(s)
- Kwanhyeong Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Juyeon Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Sang-Ah Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hyunji Moon
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Boyeon Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Deokhwan Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Young-Eun Joo
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, 61469, Korea
| | - Daeho Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea. .,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea. .,Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
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26
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Feng L, Shu Y, Wu Q, Liu T, Long H, Yang H, Li Y, Xiao B. EphA4 may contribute to microvessel remodeling in the hippocampal CA1 and CA3 areas in a mouse model of temporal lobe epilepsy. Mol Med Rep 2016; 15:37-46. [PMID: 27959424 PMCID: PMC5355650 DOI: 10.3892/mmr.2016.6017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 09/10/2016] [Indexed: 12/26/2022] Open
Abstract
Unclustered and pre-clustered ephrin-A5-Fc have identical anti-epileptic effects in the dentate gyrus of hippocampus in a mouse model of temporal lobe epilepsy (TLE), and act through alleviating ephrin receptor A4 (EphA4)-mediated neurogenesis and angiogenesis. However, the effects of ephrin-A5-Fcs on EphA4 and angiogenesis in Cornu Ammonis (CA)1 and CA3 areas remain unclear. In the present study, male C57BL/6 mice underwent pilocarpine-induced TLE. The expression of EphA4 and ephrin-A5 proteins was analyzed by immunohistochemistry, and the mean density and diameter of platelet endothelial cell adhesion molecule-1-labeled microvessels in CA1 and CA3 were calculated in the absence or presence of two types of ephrin-A5-Fc intrahippocampal infusion. Microvessels perpendicular to the pyramidal cell layer decreased; however, microvessels that traversed the layer increased, and became distorted and fragmented. The mean densities and diameters of microvessels gradually increased and remained greater than those in the control group at 56 days post-status epilepticus (SE). The upregulation of EphA4 and ephrin-A5 proteins began at 7 days and was maintained until 28 days, subsequently decreasing slightly at 56 days post-SE. Blockade of EphA4 by unclustered-ephrin-A5-Fc effected a reduction in the mean density and mean diameter of microvessels in the CA1 and CA3 areas; conversely, activation of EphA4 by clustered-ephrin-A5-Fc induced an increase in these values. Ephrin-A5 ligand binding to EphA4 receptor may contribute to angiogenesis during epileptogenesis in the hippocampal CA1 and CA3 areas.
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Affiliation(s)
- Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yi Shu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Qian Wu
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Tiantian Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Hongyu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yi Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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The Role of RhoJ in Endothelial Cell Biology and Tumor Pathology. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6386412. [PMID: 27556037 PMCID: PMC4983353 DOI: 10.1155/2016/6386412] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/24/2016] [Accepted: 06/15/2016] [Indexed: 02/04/2023]
Abstract
Background. RhoJ, an endothelially expressed member of Cdc42 (cell division cycle 42) subfamily of Rho GTPase, plays an important role in endocytic pathway, adipocyte differentiation, endothelial motility, tube formation, and focal adhesion. RhoJ is a selective and effective therapeutic target in tumor tissues or retinopathy. Methods. A systematic review was related to “small Rho GTPase” or “RhoJ” with “endothelial motility, tube formation and focal adhesion” and “tumor therapy”. This led to many cross-references involving RhoJ and these data have been incorporated into the following study. Results. We have grouped the role of RhoJ according to three main effects: RhoJ regulates endocytic pathway and adipocyte differentiation in early studies, and RhoJ shows an important role in endothelial cell biology; furthermore, RhoJ blockade serves as a target in tumor vasculature and enhances the effects of anticancer drug. Conclusions. More research is necessary to understand the role of RhoJ in many aspects, on the basis of current knowledge of the role of RhoJ blockade in tumor vessels, there are opportunities for the therapy of tumor, and RhoJ is expressed outside tumour vasculature and is involved in wound healing. Taking advantage of the opportunities could result in a development in tumor therapy.
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28
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Abstract
Rho GTPases are crucial signaling molecules that regulate a plethora of biological functions. Traditional biochemical, cell biological, and genetic approaches have founded the basis of Rho GTPase biology. The development of biosensors then allowed measuring Rho GTPase activity with unprecedented spatio-temporal resolution. This revealed that Rho GTPase activity fluctuates on time and length scales of tens of seconds and micrometers, respectively. In this review, we describe Rho GTPase activity patterns observed in different cell systems. We then discuss the growing body of evidence that upstream regulators such as guanine nucleotide exchange factors and GTPase-activating proteins shape these patterns by precisely controlling the spatio-temporal flux of Rho GTPase activity. Finally, we comment on additional mechanisms that might feed into the regulation of these signaling patterns and on novel technologies required to dissect this spatio-temporal complexity.
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Affiliation(s)
| | - Olivier Pertz
- Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Cell Biology, University of Bern, Bern, Switzerland
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29
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Wang Y, Wu Z, Thorin E, Tremblay J, Lavoie JL, Luo H, Peng J, Qi S, Wu T, Chen F, Shen J, Hu S, Wu J. Estrogen and testosterone in concert with EFNB3 regulate vascular smooth muscle cell contractility and blood pressure. Am J Physiol Heart Circ Physiol 2016; 310:H861-72. [PMID: 26851246 DOI: 10.1152/ajpheart.00873.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/02/2016] [Indexed: 12/20/2022]
Abstract
EPH kinases and their ligands, ephrins (EFNs), have vital and diverse biological functions, although their function in blood pressure (BP) control has not been studied in detail. In the present study, we report that Efnb3 gene knockout (KO) led to increased BP in female but not male mice. Vascular smooth muscle cells (VSMCs) were target cells for EFNB3 function in BP regulation. The deletion of EFNB3 augmented contractility of VSMCs from female but not male KO mice, compared with their wild-type (WT) counterparts. Estrogen augmented VSMC contractility while testosterone reduced it in the absence of EFNB3, although these sex hormones had no effect on the contractility of VSMCs from WT mice. The effect of estrogen on KO VSMC contractility was via a nongenomic pathway involving GPER, while that of testosterone was likely via a genomic pathway, according to VSMC contractility assays and GPER knockdown assays. The sex hormone-dependent contraction phenotypes in KO VSMCs were reflected in BP in vivo. Ovariectomy rendered female KO mice normotensive. At the molecular level, EFNB3 KO in VSMCs resulted in reduced myosin light chain kinase phosphorylation, an event enhancing sensitivity to Ca(2+)flux in VSMCs. Our investigation has revealed previously unknown EFNB3 functions in BP regulation and show that EFNB3 might be a hypertension risk gene in certain individuals.
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Affiliation(s)
- Yujia Wang
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Zenghui Wu
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada;
| | - Eric Thorin
- Montreal Heart Institute, Montreal, Quebec, Canada
| | - Johanne Tremblay
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Julie L Lavoie
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Département de Kinésiologie, Université de Montréal, Montreal, Quebec, Canada
| | - Hongyu Luo
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Junzheng Peng
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Shijie Qi
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Tao Wu
- Institute of Cardiology, First Affiliated Hospital, Zhejiang University Medical College, Hangzhou, China; and
| | - Fei Chen
- Institute of Cardiology, First Affiliated Hospital, Zhejiang University Medical College, Hangzhou, China; and
| | - Jianzhong Shen
- Institute of Cardiology, First Affiliated Hospital, Zhejiang University Medical College, Hangzhou, China; and
| | - Shenjiang Hu
- Institute of Cardiology, First Affiliated Hospital, Zhejiang University Medical College, Hangzhou, China; and
| | - Jiangping Wu
- Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; Nephrology Service, CRCHUM, Montreal, Quebec, Canada
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30
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Lau KHW, Amoui M, Stiffel V, Chen ST, Sheng MHC. An Osteoclastic Transmembrane Protein-Tyrosine Phosphatase Enhances Osteoclast Activity in Part by Dephosphorylating EphA4 in Osteoclasts. J Cell Biochem 2015; 116:1785-96. [PMID: 25676701 DOI: 10.1002/jcb.25137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/09/2015] [Indexed: 01/02/2023]
Abstract
We have previously shown that PTP-oc is an enhancer of the functional activity of osteoclasts and that EphA4 is a suppressor. Here, we provide evidence that PTP-oc enhances osteoclast activity in part through inactivation of EphA4 by dephosphorylating key phosphotyrosine (pY) residues of EphA4. We show that EphA4 was pulled down by the PTP-oc trapping mutant but not by the wild-type (WT) PTP-oc and that transgenic overexpression of PTP-oc in osteoclasts drastically decreased pY602 and pY779 residues of EphA4. Consistent with the previous findings that EphA4 deficiency increased pY173-Vav3 level (Rac-GTP exchange factor [GEF]) and enhanced bone resorption activity of osteoclasts, reintroduction of WT-Epha4 in Epha4 null osteoclasts led to ∼50% reduction in the pY173-Vav3 level and ∼2-fold increase in bone resorption activity. Overexpression of Y779F-Epha4 mutant in WT osteoclasts markedly increased in pY173-Vav3 and reduced bone resorption activity, but overexpression of Y602F-Epha4 mutant had no effect, suggesting that pY779 residue plays an important role in the EphA4-mediated suppression of osteoclast activity. Deficient EphA4 in osteoclasts has been shown to up-regulate Rac-GTPase and down-regulate Rho-GTPase. PTP-oc overexpression in osteoclasts also increased the GTP-Rac level to 300% of controls, but decreased the GTP-Rho level to ∼50% of controls. PTP-oc overexpression or deficient Epha4 each also reduced pY87-Ephexin level, which is a Rho GEF. Thus, PTP-oc may differentially regulate Rac signaling versus Rho signaling through dephosphorylation of EphA4, which has shown to have opposing effects on Rac-GTPase versus Rho-GTPase through differential regulation of Vav3 versus Ephexin.
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Affiliation(s)
- Kin-Hing William Lau
- Musculoskeletal Disease Center; Jerry L. Pettis Memorial VA Medical Center; Loma Linda California 92357
- Department of Medicine; Loma Linda University School of Medicine; Loma Linda California 92350
- Departments of Biochemistry; Loma Linda University School of Medicine; Loma Linda California 92350
| | - Mehran Amoui
- Musculoskeletal Disease Center; Jerry L. Pettis Memorial VA Medical Center; Loma Linda California 92357
| | - Virginia Stiffel
- Musculoskeletal Disease Center; Jerry L. Pettis Memorial VA Medical Center; Loma Linda California 92357
| | - Shin-Tai Chen
- Musculoskeletal Disease Center; Jerry L. Pettis Memorial VA Medical Center; Loma Linda California 92357
- Department of Medicine; Loma Linda University School of Medicine; Loma Linda California 92350
| | - Matilda H.-C. Sheng
- Musculoskeletal Disease Center; Jerry L. Pettis Memorial VA Medical Center; Loma Linda California 92357
- Department of Medicine; Loma Linda University School of Medicine; Loma Linda California 92350
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31
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Sun J, Xiao Y, Wang S, Slepian MJ, Wong PK. Advances in Techniques for Probing Mechanoregulation of Tissue Morphogenesis. ACTA ACUST UNITED AC 2015; 20:127-37. [DOI: 10.1177/2211068214554802] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Kurita S, Takeuchi K, Hayashi Y, Ueyama H, Zankov DP, Pang X, Otsuka T, Ohkubo I, Ogikubo O, Ogita H. Significance of serum Zn-α2-glycoprotein for the regulation of blood pressure. Hypertens Res 2014; 38:244-51. [PMID: 25427682 DOI: 10.1038/hr.2014.165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/06/2014] [Accepted: 10/14/2014] [Indexed: 11/09/2022]
Abstract
Zn-α2-glycoprotein (ZAG) (molecular weight=41 kDa) is one component in the α2 fraction of human plasma, and is reported to be associated with several diseases, such as cancers and metabolic syndromes. ZAG is also considered to be an important modulator of lipid metabolism. However, little is known about the correlation of serum ZAG levels with indicators of metabolic syndrome. Serum ZAG concentrations analyzed by enzyme-linked immunoassay were positively correlated with systolic and diastolic blood pressure in 326 subjects (236 males and 90 females) aged 17-79 years who had an annual health examination. By luciferase reporter and electrophoretic mobility shift assays, the core promoter region to regulate the ZAG gene expression was found to exist between -110 and -101. The transcription factor Sp1 interacted with this region, and Sp1 knockdown experiments showed that Sp1 critically regulated ZAG expression. Furthermore, ZAG increased the active form of RhoA, which was determined by pull-down assay. Increased serum ZAG concentrations induced, at least partly, by Sp1 may cause an increase in vascular tone through the activation of RhoA and contribute to elevated blood pressure.
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Affiliation(s)
- Souichi Kurita
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Keisuke Takeuchi
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Yoshimi Hayashi
- Department of Orthopedic Surgery, Nagoya City University, Nagoya, Japan
| | - Hisao Ueyama
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Dimitar P Zankov
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Xiaoling Pang
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Takanobu Otsuka
- Department of Orthopedic Surgery, Nagoya City University, Nagoya, Japan
| | - Iwao Ohkubo
- 1] Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan [2] Department of Nutrition, Tenshi College, Hokkaido, Japan
| | - Osamu Ogikubo
- 1] Department of Orthopedic Surgery, Nagoya City University, Nagoya, Japan [2] Department of Orthopedics, Nagoya City Rehabilitation Hospital, Aichi, Japan
| | - Hisakazu Ogita
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
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33
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Buricchi F, Giannoni E, Grimaldi G, Parri M, Raugei G, Ramponi G, Chiarugi P. Redox Regulation of Ephrin/Integrin Cross-Talk. Cell Adh Migr 2014. [DOI: 10.4161/cam.3911] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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34
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Cissé M, Checler F. Eph receptors: new players in Alzheimer's disease pathogenesis. Neurobiol Dis 2014; 73:137-49. [PMID: 25193466 DOI: 10.1016/j.nbd.2014.08.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/01/2014] [Accepted: 08/22/2014] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is devastating and leads to permanent losses of memory and other cognitive functions. Although recent genetic evidences strongly argue for a causative role of Aβ in AD onset and progression (Jonsson et al., 2012), its role in AD etiology remains a matter of debate. However, even if not the sole culprit or pathological trigger, genetic and anatomical evidences in conjunction with numerous pharmacological studies, suggest that Aβ peptides, at least contribute to the disease. How Aβ contributes to memory loss remains largely unknown. Soluble Aβ species referred to as Aβ oligomers have been shown to be neurotoxic and induce network failure and cognitive deficits in animal models of the disease. In recent years, several proteins were described as potential Aβ oligomers receptors, amongst which are the receptor tyrosine kinases of Eph family. These receptors together with their natural ligands referred to as ephrins have been involved in a plethora of physiological and pathological processes, including embryonic neurogenesis, learning and memory, diabetes, cancers and anxiety. Here we review recent discoveries on Eph receptors-mediated protection against Aβ oligomers neurotoxicity as well as their potential as therapeutic targets in AD pathogenesis.
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Affiliation(s)
- Moustapha Cissé
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
| | - Frédéric Checler
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
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35
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Batson J, Maccarthy-Morrogh L, Archer A, Tanton H, Nobes CD. EphA receptors regulate prostate cancer cell dissemination through Vav2-RhoA mediated cell-cell repulsion. Biol Open 2014; 3:453-62. [PMID: 24795148 PMCID: PMC4058079 DOI: 10.1242/bio.20146601] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Metastatic prostate cancer cells display EphB receptor-mediated attraction when they contact stromal fibroblasts but EphA-driven repulsion when they contact one another. The impact of these ‘social’ interactions between cells during cancer cell invasion and the signalling mechanisms downstream of Eph receptors are unclear. Here we show that EphA receptors regulate prostate cancer cell dissemination in a 2D dispersal assay and in a 3D cancer cell spheroid assay. We show that EphA receptors signal via the exchange factor Vav2 to activate RhoA and that both Vav2 and RhoA are required for prostate cancer cell–cell repulsion. Furthermore, we find that in EphA2/EphA4, Vav2 or RhoA siRNA-treated cells, contact repulsion can be restored by partial microtubule destabilisation. We propose that EphA–Vav2–RhoA-mediated repulsion between contacting cancer cells at the tumour edge could enhance their local invasion away from the primary tumour.
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Affiliation(s)
- Jennifer Batson
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Lucy Maccarthy-Morrogh
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - Amy Archer
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Helen Tanton
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Catherine D Nobes
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
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Mai A, Muharram G, Barrow-McGee R, Baghirov H, Rantala J, Kermorgant S, Ivaska J. Distinct c-Met activation mechanisms induce cell rounding or invasion through pathways involving integrins, RhoA and HIP1. J Cell Sci 2014; 127:1938-52. [DOI: 10.1242/jcs.140657] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
ABSTRACT
Many carcinomas have acquired oncogenic mechanisms for activating c-Met, including c-Met overexpression and excessive autocrine or paracrine stimulation with hepatocyte growth factor (HGF). However, the biological outcome of c-Met activation through these distinct modes remains ambiguous. Here, we report that HGF-mediated c-Met stimulation triggers a mesenchymal-type collective cell invasion. By contrast, the overexpression of c-Met promotes cell rounding. Moreover, in a high-throughput siRNA screen that was performed using a library of siRNAs against putative regulators of integrin activity, we identified RhoA and the clathrin-adapter protein HIP1 as crucial c-Met effectors in these morphological changes. Transient RhoA activation was necessary for the HGF-induced invasion, whereas sustained RhoA activity regulated c-Met-induced cell rounding. In addition, c-Met-induced cell rounding correlated with the phosphorylation of filamin A and the downregulation of active cell-surface integrins. By contrast, a HIP1-mediated increase in β1-integrin turnover was required for the invasion triggered by HGF. Taken together, our results indicate that c-Met induces distinct cell morphology alterations depending on the stimulus that activates c-Met.
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Affiliation(s)
- Anja Mai
- Turku Centre for Biotechnology, University of Turku, Turku 20521, Finland
- VTT Technical Research Centre of Finland, Medical Biotechnology, Turku 20520, Finland
- Department of Biochemistry and Food Chemistry, University of Turku, Turku 20521, Finland
| | - Ghaffar Muharram
- Turku Centre for Biotechnology, University of Turku, Turku 20521, Finland
- VTT Technical Research Centre of Finland, Medical Biotechnology, Turku 20520, Finland
| | - Rachel Barrow-McGee
- Spatial Signalling Team, Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ, UK
| | - Habib Baghirov
- Turku Centre for Biotechnology, University of Turku, Turku 20521, Finland
- VTT Technical Research Centre of Finland, Medical Biotechnology, Turku 20520, Finland
| | - Juha Rantala
- VTT Technical Research Centre of Finland, Medical Biotechnology, Turku 20520, Finland
| | - Stéphanie Kermorgant
- Spatial Signalling Team, Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ, UK
| | - Johanna Ivaska
- Turku Centre for Biotechnology, University of Turku, Turku 20521, Finland
- VTT Technical Research Centre of Finland, Medical Biotechnology, Turku 20520, Finland
- Department of Biochemistry and Food Chemistry, University of Turku, Turku 20521, Finland
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Stiffel V, Amoui M, Sheng MHC, Mohan S, Lau KHW. EphA4 receptor is a novel negative regulator of osteoclast activity. J Bone Miner Res 2014; 29:804-19. [PMID: 23983218 DOI: 10.1002/jbmr.2084] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 08/07/2013] [Accepted: 08/20/2013] [Indexed: 11/11/2022]
Abstract
Of the ephrin (Eph) receptors, mature osteoclasts express predominantly EphA4. This study sought to determine if EphA4 has a regulatory role in osteoclasts. Treatment of RAW/C4 cells with Epha4 small interfering RNAs (siRNAs) increased average size, Ctsk mRNA expression level, and bone resorption activity of the derived osteoclast-like cells. Activation of the EphA4 signaling in osteoclast precursors with EfnA4-fc chimeric protein reduced cell size and resorption activity of the derived osteoclasts. Homozygous Epha4 null mice had substantially less trabecular bone in femur and vertebra compared to wild-type controls. The bone loss was due to a decrease in trabecular number and an increase in trabecular spacing, but not to an increase in osteoclast-lined bone surface or an increase in the number of osteoclasts on bone surface. Dynamic histomorphometry and serum biomarker analyses indicate that bone formation in Epha4 null mice was reduced slightly but not significantly. Osteoclasts of Epha4 null mice were also larger, expressed higher levels of Mmp3 and Mmp9 mRNAs, and exhibited greater bone resorption activity than wild-type osteoclasts in vitro. Deficient Epha4 expression had no effects on the total number of osteoclast formed in response to receptor activator of NF-κB ligand nor on apoptosis of osteoclasts in vitro. It also did not affect the protein-tyrosine phosphorylation status of its ligands, EfnB2, EfnA2, and EfnA4, in osteoclasts. Deficient Epha4 expression in Epha4 null osteoclasts activated the β3 -integrin signaling through reduced phosphorylation of the tyr-747 residue, which led to increased binding of the stimulatory talin and reduced binding of the inhibitory Dok1 to β3 -integrin. This in turn activated Vav3 and the bone resorption activity of osteoclasts. In conclusion, we demonstrate for the first time that EphA4 is a potent negative regulator of osteoclastic activity, mediated in part through increased Dok1 binding to β3 -integrin via an increase in EphA4-dependent tyr-747 phosphorylation.
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Affiliation(s)
- Virginia Stiffel
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA
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Majima T, Takeuchi K, Sano K, Hirashima M, Zankov DP, Tanaka-Okamoto M, Ishizaki H, Miyoshi J, Ogita H. An Adaptor Molecule Afadin Regulates Lymphangiogenesis by Modulating RhoA Activity in the Developing Mouse Embryo. PLoS One 2013; 8:e68134. [PMID: 23840823 PMCID: PMC3694064 DOI: 10.1371/journal.pone.0068134] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 05/26/2013] [Indexed: 12/22/2022] Open
Abstract
Afadin is an intracellular binding partner of nectins, cell-cell adhesion molecules, and plays important roles in the formation of cell-cell junctions. Afadin-knockout mice show early embryonic lethality, therefore little is known about the function of afadin during organ development. In this study, we generated mice lacking afadin expression in endothelial cells, and found that the majority of these mice were embryonically lethal as a result of severe subcutaneous edema. Defects in the lymphatic vessels of the skin were observed, although the morphology in the blood vessels was almost normal. Severe disruption of VE-cadherin-mediated cell-cell junctions occurred only in lymphatic endothelial cells, but not in blood endothelial cells. Knockout of afadin did not affect the differentiation and proliferation of lymphatic endothelial cells. Using in vitro assays with blood and lymphatic microvascular endothelial cells (BMVECs and LMVECs, respectively), knockdown of afadin caused elongated cell shapes and disruption of cell-cell junctions among LMVECs, but not BMVECs. In afadin-knockdown LMVECs, enhanced F-actin bundles at the cell periphery and reduced VE-cadherin immunostaining were found, and activation of RhoA was strongly increased compared with that in afadin-knockdown BMVECs. Conversely, inhibition of RhoA activation in afadin-knockdown LMVECs restored the cell morphology. These results indicate that afadin has different effects on blood and lymphatic endothelial cells by controlling the levels of RhoA activation, which may critically regulate the lymphangiogenesis of mouse embryos.
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Affiliation(s)
- Takashi Majima
- Department of Molecular Biology, Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka, Japan
| | - Keisuke Takeuchi
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Keigo Sano
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Masanori Hirashima
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Dimitar P. Zankov
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
| | - Miki Tanaka-Okamoto
- Department of Molecular Biology, Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka, Japan
| | - Hiroyoshi Ishizaki
- Department of Molecular Biology, Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka, Japan
| | - Jun Miyoshi
- Department of Molecular Biology, Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka, Japan
| | - Hisakazu Ogita
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Shiga, Japan
- * E-mail:
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The small GTPase RhoA is required for proper locomotor circuit assembly. PLoS One 2013; 8:e67015. [PMID: 23825607 PMCID: PMC3692541 DOI: 10.1371/journal.pone.0067015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 05/13/2013] [Indexed: 11/19/2022] Open
Abstract
The assembly of neuronal circuits during development requires the precise navigation of axons, which is controlled by attractive and repulsive guidance cues. In the developing spinal cord, ephrinB3 functions as a short-range repulsive cue that prevents EphA4 receptor-expressing corticospinal tract and spinal interneuron axons from crossing the midline, ensuring proper formation of locomotor circuits. Here we report that the small GTPase RhoA, a key regulator of cytoskeletal dynamics, is also required for ephrinB3/EphA4-dependent locomotor circuit formation. Deletion of RhoA from neural progenitor cells results in mice that exhibit a rabbit-like hopping gait, which phenocopies mice lacking ephrinB3 or EphA4. Consistent with this locomotor defect, we found that corticospinal tract axons and spinal interneuron projections from RhoA-deficient mice aberrantly cross the spinal cord midline. Furthermore, we determined that loss of RhoA blocks ephrinB3-induced growth cone collapse of cortical axons and disrupts ephrinB3 expression at the spinal cord midline. Collectively, our results demonstrate that RhoA is essential for the ephrinB3/EphA4-dependent assembly of cortical and spinal motor circuits that control normal locomotor behavior.
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Sällström J, Peuckert C, Gao X, Larsson E, Nilsson A, Jensen BL, Onozato ML, Persson AEG, Kullander K, Carlström M. Impaired EphA4 signaling leads to congenital hydronephrosis, renal injury, and hypertension. Am J Physiol Renal Physiol 2013; 305:F71-9. [PMID: 23637205 DOI: 10.1152/ajprenal.00694.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Experimental hydronephrosis induced by partial ureteral obstruction at 3 wk of age causes hypertension and renal impairment in adult rats and mice. Signaling by Ephrin receptors (Eph) and their ligands (ephrins) importantly regulates embryonic development. Genetically modified mice, where the cytoplasmic domain of the EphA4 receptor has been substituted by enhanced green fluorescent protein (EphA4gf/gf), develop spontaneous hydronephrosis and provide a model for further studies of the disorder. The present study aimed to determine if animals with congenital hydronephrosis develop hypertension and renal injuries, similar to that of experimental hydronephrosis. Ultrasound and Doppler techniques were used to visualize renal impairment in the adult mice. Telemetric blood pressure measurements were performed in EphA4gf/gf mice and littermate controls (EphA4+/+) during normal (0.7% NaCl)- and high (4% NaCl)-sodium conditions. Renal excretion, renal plasma flow, and glomerular filtration were studied, and histology and morphology of the kidneys and ureters were performed. EphA4gf/gf mice developed variable degrees of hydronephrosis that correlated with their blood pressure level. In contrast to EphA4+/+, the EphA4gf/gf mice displayed salt-sensitive hypertension, reduced urine concentrating ability, reduced renal plasma flow, and lower glomerular filtration rate. Kidneys from EphA4gf/gf mice showed increased renal injuries, as evidenced by fibrosis, inflammation, and glomerular and tubular changes. In conclusion, congenital hydronephrosis causes hypertension and renal damage, similar to that observed in experimentally induced hydronephrosis. This study further reinforces the supposed causal link between hydronephrosis and later development of hypertension in humans.
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Affiliation(s)
- Johan Sällström
- Deptartment of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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O'Neal WT, Griffin WF, Dries-Devlin JL, Kent SD, Chen J, Willis MS, Virag JAI. Ephrin-Eph signaling as a potential therapeutic target for the treatment of myocardial infarction. Med Hypotheses 2013; 80:738-44. [PMID: 23562676 DOI: 10.1016/j.mehy.2013.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 01/27/2013] [Accepted: 02/28/2013] [Indexed: 01/22/2023]
Abstract
Although numerous strategies have been developed to reduce the initial ischemic insult and cellular injury that occurs during myocardial infarction (MI), few have progressed into the clinical arena. The epidemiologic and economic impact of MI necessitates the development of innovative therapies to rapidly and effectively reduce the initial injury and subsequent cardiac dysfunction. The Eph receptors and their cognate ligands, the ephrins, are the largest family of receptor tyrosine kinases, and their signaling has been shown to play a diverse role in various cellular processes. The recent advances in the study of ephrin-Eph signaling have shown promising progress in many fields of medicine. They have been implicated in the pathophysiology of various cancers and in the regulation of inflammation and apoptosis. Recent studies have shown that manipulation of ephrin-Eph cell signaling can favorably influence cardiomyocyte viability and ultimately preserve cardiac function post-MI. In this article, we explore the hypothesis that manipulation of ephrin-Eph signaling may potentially be a novel therapeutic target in the treatment of MI through alteration of the cellular processes that govern injury and wound healing.
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Affiliation(s)
- Wesley T O'Neal
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
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42
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Batson J, Astin JW, Nobes CD. Regulation of contact inhibition of locomotion by Eph-ephrin signalling. J Microsc 2013; 251:232-41. [PMID: 23495724 PMCID: PMC3838626 DOI: 10.1111/jmi.12024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/07/2013] [Indexed: 01/20/2023]
Abstract
Contact inhibition of locomotion (CIL) occurs when a cell stops migrating in a particular direction upon contact with another cell. Many cancer cells show Contact inhibition of locomotion when contacting one another but display contact-unimpeded migration following collision with noncancer cells. Here we review current understanding of Contact inhibition of locomotion, from Abercrombie's historical studies of cells in tissue culture to more recent analyses of Contact inhibition of locomotion in vivo. We discuss the cellular machinery required for CIL and the molecular signals that regulate it. We focus on our recent finding that in prostate cancer cells, Contact inhibition of locomotion is regulated by a balance between EphA and EphB receptor signalling. We show that, as recently described for chick heart fibroblasts, microtubule dynamics are required for Contact inhibition of locomotion in prostate cancer cells and we propose that stabilization of microtubules could account for defective Contact inhibition of locomotion between cancer cells and noncancer cells.
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Affiliation(s)
- J Batson
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
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43
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Li J, Johnson SE. Ephrin-A5 promotes bovine muscle progenitor cell migration before mitotic activation. J Anim Sci 2013; 91:1086-93. [PMID: 23296833 DOI: 10.2527/jas.2012-5728] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Satellite cells are the resident stem cell population of adult skeletal muscle tissue that is responsible for growth and regeneration. The cells typically congregate near the tips of the muscle fibers and in close proximity to the neural muscular junction (NMJ). Ephrin-A5 is a chemotactic molecule that participates in the correct positioning and formation of the NMJ. The objective of the experiment was to examine the effects of ephrin-A5 signaling on bovine satellite cell (BSC) biology. Primary cultures of BSC demonstrate changes in velocity with time in culture that is unique to the Paired box protein 7 (Pax7):Myogenic factor 5 (Myf5) subpopulation. Treatment of the BSC with ephrin-A5 causes a reduction (P < 0.05) in velocity with a concomitant increase (P < 0.05) in directed migration. The chemoattractant properties of ephrin-A5 occur before myogenic differentiation 1 (MyoD) expression in the myogenic precursors and are abrogated after their differentiation to committed myoblasts. Ephrin-A5 induced migration appears to require components of the Ras homolog gene family member A (RhoA) and Rho-associated protein kinase (ROCK) signaling machinery. Supplementation of culture media with a chemical ROCK inhibitor suppressed (P < 0.05) ephrin-A5 initiated BSC migration. These results contrast with treatment of BSC with hepatocyte growth factor (HGF), a key modulator of myogenic and motogenic activity. Treatment of BSC with HGF had no effect on cell motility or migration immediately after culture establishment. Twenty-four hours after culture establishment, BSC demonstrated an increase (P < 0.05) in transwell migration toward HGF. These results document that temporal and spatial gradients of chemokines and growth factors participate in the localization of BSC within the niche.
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Affiliation(s)
- J Li
- Department of Animal Sciences, University of Florida, Gainesville 32611, USA
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44
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Funk SD, Orr AW. Ephs and ephrins resurface in inflammation, immunity, and atherosclerosis. Pharmacol Res 2013; 67:42-52. [DOI: 10.1016/j.phrs.2012.10.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 10/04/2012] [Accepted: 10/10/2012] [Indexed: 01/13/2023]
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Kather JN, Kroll J. Rho guanine exchange factors in blood vessels: fine-tuners of angiogenesis and vascular function. Exp Cell Res 2012; 319:1289-97. [PMID: 23261542 DOI: 10.1016/j.yexcr.2012.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 01/08/2023]
Abstract
The angiogenic cascade is a multi-step process essential for embryogenesis and other physiological and pathological processes. Rho family GTPases are binary molecular switches and serve as master regulators of various basic cellular processes. Rho GTPases are known to exert important functions in angiogenesis and vascular physiology. These functions demand a tight and context-specific control of cellular processes requiring superordinate control by a multitude of guanine nucleotide exchange factors (GEFs). GEFs display various features enabling them to fine-tune the actions of Rho GTPases in the vasculature: (1) GEFs regulate specific steps of the angiogenic cascade; (2) GEFs show a spatio-temporally specific expression pattern; (3) GEFs differentially regulate endothelial function depending on their subcellular location; (4) GEFs mediate crosstalk between complex signaling cascades and (5) GEFs themselves are regulated by another layer of interacting proteins. The aim of this review is to provide an overview about the role of GEFs in regulating angiogenesis and vascular function and to point out current limitations as well as clinical perspectives.
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Affiliation(s)
- Jakob Nikolas Kather
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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46
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Kusuhara S, Fukushima Y, Fukuhara S, Jakt LM, Okada M, Shimizu Y, Hata M, Nishida K, Negi A, Hirashima M, Mochizuki N, Nishikawa SI, Uemura A. Arhgef15 promotes retinal angiogenesis by mediating VEGF-induced Cdc42 activation and potentiating RhoJ inactivation in endothelial cells. PLoS One 2012; 7:e45858. [PMID: 23029280 PMCID: PMC3448698 DOI: 10.1371/journal.pone.0045858] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 08/22/2012] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Drugs inhibiting vascular endothelial growth factor (VEGF) signaling are globally administered to suppress deregulated angiogenesis in a variety of eye diseases. However, anti-VEGF therapy potentially affects the normal functions of retinal neurons and glias which constitutively express VEGF receptor 2. Thus, it is desirable to identify novel drug targets which are exclusively expressed in endothelial cells (ECs). Here we attempted to identify an EC-specific Rho guanine nucleotide exchange factor (GEF) and evaluate its role in retinal angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS By exploiting fluorescence-activated cell sorting and microarray analyses in conjunction with in silico bioinformatics analyses, we comprehensively identified endothelial genes in angiogenic retinal vessels of postnatal mice. Of 9 RhoGEFs which were highly expressed in retinal ECs, we show that Arhgef15 acted as an EC-specific GEF to mediate VEGF-induced Cdc42 activation and potentiated RhoJ inactivation, thereby promoting actin polymerization and cell motility. Disruption of the Arhgef15 gene led to delayed extension of vascular networks and subsequent reduction of total vessel areas in postnatal mouse retinas. CONCLUSIONS/SIGNIFICANCE Our study provides information useful to the development of new means of selectively manipulating angiogenesis without affecting homeostasis in un-targeted tissues; not only in eyes but also in various disease settings such as cancer.
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Affiliation(s)
- Sentaro Kusuhara
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yoko Fukushima
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
- Department of Ophthalmology, Osaka University Medical School, Osaka, Japan
| | - Shigetomo Fukuhara
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Lars Martin Jakt
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Mitsuhiro Okada
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Yuri Shimizu
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Masayuki Hata
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kohji Nishida
- Department of Ophthalmology, Osaka University Medical School, Osaka, Japan
| | - Akira Negi
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masanori Hirashima
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Naoki Mochizuki
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Shin-Ichi Nishikawa
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Akiyoshi Uemura
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
- Division of Vascular Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
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47
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Salvucci O, Tosato G. Essential roles of EphB receptors and EphrinB ligands in endothelial cell function and angiogenesis. Adv Cancer Res 2012; 114:21-57. [PMID: 22588055 DOI: 10.1016/b978-0-12-386503-8.00002-8] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Eph receptor tyrosine kinases and their Ephrin ligands represent an important signaling system with widespread roles in cell physiology and disease. Receptors and ligands in this family are anchored to the cell surface; thus Eph/Ephrin interactions mainly occur at sites of cell-to-cell contact. EphB4 and EphrinB2 are the Eph/Ephrin molecules that play essential roles in vascular development and postnatal angiogenesis. Analysis of expression patterns and function has linked EphB4/EphrinB2 to endothelial cell growth, survival, migration, assembly, and angiogenesis. Signaling from these molecules is complex, with the potential for being bidirectional, emanating both from the Eph receptors (forward signaling) and from the Ephrin ligands (reverse signaling). In this review, we describe recent advances on the roles of EphB/EphrinB protein family in endothelial cell function and outline potential approaches to inhibit pathological angiogenesis based on this understanding.
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Affiliation(s)
- Ombretta Salvucci
- Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
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48
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Nievergall E, Lackmann M, Janes PW. Eph-dependent cell-cell adhesion and segregation in development and cancer. Cell Mol Life Sci 2012; 69:1813-42. [PMID: 22204021 PMCID: PMC11114713 DOI: 10.1007/s00018-011-0900-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/06/2011] [Accepted: 11/28/2011] [Indexed: 01/23/2023]
Abstract
Numerous studies attest to essential roles for Eph receptors and their ephrin ligands in controlling cell positioning and tissue patterning during normal and oncogenic development. These studies suggest multiple, sometimes contradictory, functions of Eph-ephrin signalling, which under different conditions can promote either spreading and cell-cell adhesion or cytoskeletal collapse, cell rounding, de-adhesion and cell-cell segregation. A principle determinant of the balance between these two opposing responses is the degree of receptor/ligand clustering and activation. This equilibrium is likely altered in cancers and modulated by somatic mutations of key Eph family members that have emerged as candidate cancer markers in recent profiling studies. In addition, cross-talk amongst Ephs and with other signalling pathways significantly modulates cell-cell adhesion, both between and within Eph- and ephrin-expressing cell populations. This review summarises our current understanding of how Eph receptors control cell adhesion and morphology, and presents examples demonstrating the importance of these events in normal development and cancer.
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Affiliation(s)
- Eva Nievergall
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
- Present Address: Haematology Department, SA Pathology, Frome Road, Adelaide, SA 5000 Australia
| | - Martin Lackmann
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
| | - Peter W. Janes
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
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Abstract
The early blood vessels of the embryo and yolk sac in mammals develop by aggregation of de novo-forming angioblasts into a primitive vascular plexus, which then undergoes a complex remodeling process. Angiogenesis is also important for disease progression in the adult. However, the precise molecular mechanism of vascular development remains unclear. It is therefore of great interest to determine which genes are specifically expressed in developing endothelial cells (ECs). Here, we used Flk1-deficient mouse embryos, which lack ECs, to perform a genome-wide survey for genes related to vascular development. We identified 184 genes that are highly enriched in developing ECs. The human orthologs of most of these genes were also expressed in HUVECs, and small interfering RNA knockdown experiments on 22 human orthologs showed that 6 of these genes play a role in tube formation by HUVECs. In addition, we created Arhgef15 knockout and RhoJ knockout mice by a gene-targeting method and found that Arhgef15 and RhoJ were important for neonatal retinal vascularization. Thus, the genes identified in our survey show high expression in ECs; further analysis of these genes should facilitate our understanding of the molecular mechanisms of vascular development in the mouse.
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50
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Wu Z, Luo H, Thorin E, Tremblay J, Peng J, Lavoie JL, Wang Y, Qi S, Wu T, Wu J. Possible role of Efnb1 protein, a ligand of Eph receptor tyrosine kinases, in modulating blood pressure. J Biol Chem 2012; 287:15557-69. [PMID: 22393061 DOI: 10.1074/jbc.m112.340869] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eph kinases constitute the largest receptor tyrosine kinase family, and their ligands, ephrins (Efns), are also cell surface molecules. Although they are ligands, Efns can transduce signals reversely into cells. We have no prior knowledge of the role played by any members of this family of kinases or their ligands in blood pressure (BP) regulation. In the present studies, we investigated the role of Efnb1 in vascular smooth muscle cell (VSMC) contractility and BP regulation. We revealed that reverse signaling through Efnb1 led to a reduction of RhoA activation and VSMC contractility in vitro. Consistent with this finding, ex vivo, there was an increase of RhoA activity accompanied by augmented myosin light chain phosphorylation in mesenteric arteries from mice with smooth muscle-specific conditional Efnb1 gene knock-out (KO). Small interfering RNA knockdown of Grip1, a molecule associated with the Efnb1 intracellular tail, partially eliminated the effect of Efnb1 on VSMC contractility and myosin light chain phosphorylation. In support of these in vitro and ex vivo results, Efnb1 KO mice on a high salt diet showed a statistically significant heightened increment of BP at multiple time points during stress compared with wild type littermates. Our results demonstrate that Efnb1 is a previously unknown negative regulator of VSMC contractility and BP and that it exerts such effects via reverse signaling through Grip1.
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Affiliation(s)
- Zenghui Wu
- Nephrology Department, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec H2L 4M1, Canada
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