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Lechuga S, Marino-Melendez A, Naydenov NG, Zafar A, Braga-Neto MB, Ivanov AI. Regulation of Epithelial and Endothelial Barriers by Molecular Chaperones. Cells 2024; 13:370. [PMID: 38474334 PMCID: PMC10931179 DOI: 10.3390/cells13050370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024] Open
Abstract
The integrity and permeability of epithelial and endothelial barriers depend on the formation of tight junctions, adherens junctions, and a junction-associated cytoskeleton. The establishment of this junction-cytoskeletal module relies on the correct folding and oligomerization of its protein components. Molecular chaperones are known regulators of protein folding and complex formation in different cellular compartments. Mammalian cells possess an elaborate chaperone network consisting of several hundred chaperones and co-chaperones. Only a small part of this network has been linked, however, to the regulation of intercellular adhesions, and the systematic analysis of chaperone functions at epithelial and endothelial barriers is lacking. This review describes the functions and mechanisms of the chaperone-assisted regulation of intercellular junctions. The major focus of this review is on heat shock protein chaperones, their co-chaperones, and chaperonins since these molecules are the focus of the majority of the articles published on the chaperone-mediated control of tissue barriers. This review discusses the roles of chaperones in the regulation of the steady-state integrity of epithelial and vascular barriers as well as the disruption of these barriers by pathogenic factors and extracellular stressors. Since cytoskeletal coupling is essential for junctional integrity and remodeling, chaperone-assisted assembly of the actomyosin cytoskeleton is also discussed.
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Affiliation(s)
- Susana Lechuga
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
| | - Armando Marino-Melendez
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
| | - Nayden G. Naydenov
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
| | - Atif Zafar
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
| | - Manuel B. Braga-Neto
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Andrei I. Ivanov
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA; (S.L.); (A.M.-M.); (N.G.N.); (A.Z.); (M.B.B.-N.)
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Zhu H, Shen F, Liao T, Qian H, Liu Y. Immunosenescence and macrophages: From basics to therapeutics. Int J Biochem Cell Biol 2023; 165:106479. [PMID: 37866656 DOI: 10.1016/j.biocel.2023.106479] [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: 06/28/2023] [Revised: 10/06/2023] [Accepted: 10/18/2023] [Indexed: 10/24/2023]
Abstract
Ageing decreases the function of the immune system and increases susceptibility to some chronic, infectious, and autoimmune diseases. Senescence cells, which produce senescence-associated secretory phenotypes (SASPs), can activate the innate and adaptive immune responses. Macrophages are among the most abundant innate immune cell types in senescent microenvironments. Senescence-associated macrophages, recruited by SASPs, play a vital role in establishing the essential microenvironments for maintaining tissue homeostasis. However, it's important to note that these senescence-associated macrophages can also influence senescent processes, either by enhancing or impeding the functions of tissue-resident senescent cells. In this discussion, we describe the potential targets of immunosenescence and shed light on the probable mechanisms by which macrophages influence cellular senescence. Furthermore, we analyze their dual function in both clearing senescent cells and modulating age-related diseases. This multifaceted influence operates through processes including heightened inflammation, phagocytosis, efferocytosis, and autophagy. Given the potential off-target effects and immune evasion mechanisms associated with traditional anti-ageing strategies (senolytics and senomorphics), 'resetting' immune system tolerance or targeting senescence-related macrophage functions (i.e., phagocytotic capacity and immunosurveillance) will inform treatment of age-related diseases. Therefore, we review recent advances in the use of macrophage therapeutics to treat ageing and age-associated disorders, and outline the key gaps in this field.
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Affiliation(s)
- Hongkang Zhu
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, China
| | | | - Tingting Liao
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, China
| | - He Qian
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, China.
| | - Yu Liu
- Wuxi 9th People's Hospital Affiliated to Soochow University, Wuxi 214062, China.
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Yuan Q, Fan Y, Liu Z, Wang X, Jia M, Dong Y, Geng Z, Zheng J, Lu X. Pleckstrin homology and RhoGEF domain containing G4 (PLEKHG4) leads to the activation of RhoGTPases promoting the malignant phenotypes of thyroid cancer. Apoptosis 2023; 28:1315-1331. [PMID: 37336836 DOI: 10.1007/s10495-023-01861-1] [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] [Accepted: 05/30/2023] [Indexed: 06/21/2023]
Abstract
Thyroid cancer (TC) is one of the most common endocrine system cancers, and its incidence is elevating. There is an urgent need to develop a deeper understanding of TC pathogenesis and explore new therapeutic target for its treatment. This study aimed to investigate the effects of pleckstrin homology and RhoGEF domain containing G4 (PLEKHG4) on the progression of TC. Herein, 29 pairs of TC and adjacent tissues were used to assess the expression of PLEKHG4. A xenograft model of mouse was established by subcutaneously injected with TC cells. Lung metastasis model was established through left ventricular injection. The results revealed that PLEKHG4 was up-regulated in human TC tissues. PLEKHG4 level was correlated with clinicopathological parameters of TC patients. In vitro assays revealed that PLEKHG4 promoted TC cell proliferation, migration, invasion, and epithelial-mesenchymal transformation. Knockdown of PLEKHG4 led to the opposite effects, and the loss of PLEKHG4 enhanced the apoptosis ability and inhibited the stemness properties of TC cells. These findings were further confirmed by the in vivo growth and lung metastasis of TC tumor. Mechanistically, PLEKHG4 promoted the activation of RhoGTPases RhoA, Cdc42, and Rac1. The inhibitors of these RhoGTPases reversed the PLEKHG4-induced malignant phenotypes. Additionally, ubiquitin-conjugating enzyme E2O (UBE2O), a large E2 ubiquitin-conjugating enzyme acted as an ubiquitin enzyme of PLEKHG4, facilitated its ubiquitination and degradation. In conclusion, PLEKHG4, regulated by UBE2O, promoted the thyroid cancer progression via activating the RhoGTPases pathway. UBE2O/PLEKHG4/RhoGTPases axis is expected to be a novel a therapeutic target for TC treatment.
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Affiliation(s)
- Qingling Yuan
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China.
| | - Yuxia Fan
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Zheng Liu
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Xiaoming Wang
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Meng Jia
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Yongqiang Dong
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Zushi Geng
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Jian Zheng
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China
| | - Xiubo Lu
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China.
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Kim S, Kim N, Kang HM, Jang HJ, Lee AC, Na KJ. Canine Somatic Mutations from Whole-Exome Sequencing of B-Cell Lymphomas in Six Canine Breeds-A Preliminary Study. Animals (Basel) 2023; 13:2846. [PMID: 37760246 PMCID: PMC10525272 DOI: 10.3390/ani13182846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/05/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Canine lymphoma (CL) is one of the most common malignant tumors in dogs. The cause of CL remains unclear. Genetic mutations that have been suggested as possible causes of CL are not fully understood. Whole-exome sequencing (WES) is a time- and cost-effective method for detecting genetic variants targeting only the protein-coding regions (exons) that are part of the entire genome region. A total of eight patients with B-cell lymphomas were recruited, and WES analysis was performed on whole blood and lymph node aspirate samples from each patient. A total of 17 somatic variants (GOLIM4, ITM2B, STN1, UNC79, PLEKHG4, BRF1, ENSCAFG00845007156, SEMA6B, DSC1, TNFAIP1, MYLK3, WAPL, ADORA2B, LOXHD1, GP6, AZIN1, and NCSTN) with moderate to high impact were identified by WES analysis. Through a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of 17 genes with somatic mutations, a total of 16 pathways were identified. Overall, the somatic mutations identified in this study suggest novel candidate mutations for CL, and further studies are needed to confirm the role of these mutations.
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Affiliation(s)
- Sungryong Kim
- Laboratory of Veterinary Laboratory Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea; (S.K.); (H.-M.K.)
| | - Namphil Kim
- Biophotonics and Nano Engineering Laboratory, Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea;
| | - Hyo-Min Kang
- Laboratory of Veterinary Laboratory Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea; (S.K.); (H.-M.K.)
| | - Hye-Jin Jang
- Department of Biomedical Laboratory Science, Daegu Health College, Daegu 41453, Republic of Korea;
| | | | - Ki-Jeong Na
- Laboratory of Veterinary Laboratory Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea; (S.K.); (H.-M.K.)
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Machin PA, Tsonou E, Hornigold DC, Welch HCE. Rho Family GTPases and Rho GEFs in Glucose Homeostasis. Cells 2021; 10:cells10040915. [PMID: 33923452 PMCID: PMC8074089 DOI: 10.3390/cells10040915] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/17/2022] Open
Abstract
Dysregulation of glucose homeostasis leading to metabolic syndrome and type 2 diabetes is the cause of an increasing world health crisis. New intriguing roles have emerged for Rho family GTPases and their Rho guanine nucleotide exchange factor (GEF) activators in the regulation of glucose homeostasis. This review summates the current knowledge, focusing in particular on the roles of Rho GEFs in the processes of glucose-stimulated insulin secretion by pancreatic β cells and insulin-stimulated glucose uptake into skeletal muscle and adipose tissues. We discuss the ten Rho GEFs that are known so far to regulate glucose homeostasis, nine of which are in mammals, and one is in yeast. Among the mammalian Rho GEFs, P-Rex1, Vav2, Vav3, Tiam1, Kalirin and Plekhg4 were shown to mediate the insulin-stimulated translocation of the glucose transporter GLUT4 to the plasma membrane and/or insulin-stimulated glucose uptake in skeletal muscle or adipose tissue. The Rho GEFs P-Rex1, Vav2, Tiam1 and β-PIX were found to control the glucose-stimulated release of insulin by pancreatic β cells. In vivo studies demonstrated the involvement of the Rho GEFs P-Rex2, Vav2, Vav3 and PDZ-RhoGEF in glucose tolerance and/or insulin sensitivity, with deletion of these GEFs either contributing to the development of metabolic syndrome or protecting from it. This research is in its infancy. Considering that over 80 Rho GEFs exist, it is likely that future research will identify more roles for Rho GEFs in glucose homeostasis.
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Affiliation(s)
- Polly A. Machin
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
| | - Elpida Tsonou
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - David C. Hornigold
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - Heidi C. E. Welch
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Correspondence: ; Tel.: +44-(0)1223-496-596
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Ninomiya K, Ohta K, Yamashita K, Mizuno K, Ohashi K. PLEKHG4B enables actin cytoskeletal remodeling during epithelial cell-cell junction formation. J Cell Sci 2021; 134:224080. [PMID: 33310911 DOI: 10.1242/jcs.249078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 12/03/2020] [Indexed: 12/25/2022] Open
Abstract
Cell-cell junction formation requires actin cytoskeletal remodeling. Here, we show that PLEKHG4B, a Rho-guanine nucleotide exchange factor (Rho-GEF), plays a crucial role in epithelial cell-cell junction formation. Knockdown of PLEKHG4B decreased Cdc42 activity and tended to increase RhoA activity in A549 cells. A549 monolayer cells showed 'closed junctions' with closely packed actin bundles along the cell-cell contacts, but PLEKHG4B knockdown suppressed closed junction formation, and PLEKHG4B-knockdown cells exhibited 'open junctions' with split actin bundles located away from the cell-cell boundary. In Ca2+-switch assays, PLEKHG4B knockdown delayed the conversion of open junctions to closed junctions and β-catenin accumulation at cell-cell junctions. Furthermore, PLEKHG4B knockdown abrogated the reduction in myosin activity normally seen in the later stage of junction formation. The aberrant myosin activation and impairments in closed junction formation in PLEKHG4B-knockdown cells were reverted by ROCK inhibition or LARG/PDZ-RhoGEF knockdown. These results suggest that PLEKHG4B enables actin remodeling during epithelial cell-cell junction maturation, probably by reducing myosin activity in the later stage of junction formation, through suppressing LARG/PDZ-RhoGEF and RhoA-ROCK pathway activities. We also showed that annexin A2 participates in PLEKHG4B localization to cell-cell junctions.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Komaki Ninomiya
- Laboratory of Molecular and Cellular Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan
| | - Kai Ohta
- Laboratory of Molecular and Cellular Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan
| | - Kazunari Yamashita
- Laboratory of Molecular and Cellular Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan
| | - Kensaku Mizuno
- Laboratory of Molecular and Cellular Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan .,Institute of Liberal Arts and Sciences, Tohoku University, Kawauchi, Sendai, Miyagi 980-8576, Japan
| | - Kazumasa Ohashi
- Laboratory of Molecular and Cellular Biology, Graduate School of Life Sciences, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan .,Department of Chemistry, Graduate School of Science, Tohoku University, Aobayama, Sendai, Miyagi 980-8578, Japan
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Takenaka N, Nakao M, Hasegawa K, Chan MP, Satoh T. The guanine nucleotide exchange factor FLJ00068 activates Rac1 in adipocyte insulin signaling. FEBS Lett 2020; 594:4370-4380. [PMID: 32978791 DOI: 10.1002/1873-3468.13939] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/31/2020] [Accepted: 09/10/2020] [Indexed: 12/26/2022]
Abstract
Insulin stimulates glucose uptake via the translocation of the glucose transporter GLUT4 to the plasma membrane in adipocytes. Several lines of evidence suggest that the small GTPase Rac1 plays an important role in insulin-stimulated glucose uptake in skeletal muscle and adipocytes. The purpose of this study is to investigate the mechanisms whereby Rac1 is regulated in adipocyte insulin signaling. Here, we show that knockdown of the guanine nucleotide exchange factor FLJ00068 inhibits Rac1 activation and GLUT4 translocation by insulin and a constitutively activated form of the protein kinase Akt2. Furthermore, constitutively activated FLJ00068 induced Rac1 activation and Rac1-dependent GLUT4 translocation. Collectively, these results suggest the involvement of FLJ00068 downstream of Akt2 in insulin-stimulated glucose uptake signaling in adipocytes.
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Affiliation(s)
- Nobuyuki Takenaka
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
| | - Mika Nakao
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
| | - Kiko Hasegawa
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
| | - Man Piu Chan
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
| | - Takaya Satoh
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
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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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Satoh T, Takenaka N. A critical role for the small GTPase Rac1 in insulin signaling that regulates glucose uptake in skeletal muscle. RESEARCH ON CHEMICAL INTERMEDIATES 2019. [DOI: 10.1007/s11164-019-03976-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Niftullayev S, Lamarche-Vane N. Regulators of Rho GTPases in the Nervous System: Molecular Implication in Axon Guidance and Neurological Disorders. Int J Mol Sci 2019; 20:E1497. [PMID: 30934641 PMCID: PMC6471118 DOI: 10.3390/ijms20061497] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022] Open
Abstract
One of the fundamental steps during development of the nervous system is the formation of proper connections between neurons and their target cells-a process called neural wiring, failure of which causes neurological disorders ranging from autism to Down's syndrome. Axons navigate through the complex environment of a developing embryo toward their targets, which can be far away from their cell bodies. Successful implementation of neuronal wiring, which is crucial for fulfillment of all behavioral functions, is achieved through an intimate interplay between axon guidance and neural activity. In this review, our focus will be on axon pathfinding and the implication of some of its downstream molecular components in neurological disorders. More precisely, we will talk about axon guidance and the molecules implicated in this process. After, we will briefly review the Rho family of small GTPases, their regulators, and their involvement in downstream signaling pathways of the axon guidance cues/receptor complexes. We will then proceed to the final and main part of this review, where we will thoroughly comment on the implication of the regulators for Rho GTPases-GEFs (Guanine nucleotide Exchange Factors) and GAPs (GTPase-activating Proteins)-in neurological diseases and disorders.
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Affiliation(s)
- Sadig Niftullayev
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
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Low Electric Treatment activates Rho GTPase via Heat Shock Protein 90 and Protein Kinase C for Intracellular Delivery of siRNA. Sci Rep 2019; 9:4114. [PMID: 30858501 PMCID: PMC6412017 DOI: 10.1038/s41598-019-40904-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 01/28/2019] [Indexed: 11/08/2022] Open
Abstract
Low electric treatment (LET) promotes intracellular delivery of naked siRNA by altering cellular physiology. However, which signaling molecules and cellular events contribute to LET-mediated siRNA uptake are unclear. Here, we used isobaric tags in relative and absolute quantification (iTRAQ) proteomic analysis to identify changes in the levels of phosphorylated proteins that occur during cellular uptake of siRNA promoted by LET. iTRAQ analysis revealed that heat shock protein 90 (Hsp90)α and myristoylated alanine-rich C-kinase substrate (Marcks) were highly phosphorylated following LET of NIH 3T3 cells, but not untreated cells. Furthermore, the levels of phosphorylated Hsp90α and protein kinase C (PKC)γ were increased by LET both with siRNA and liposomes having various physicochemical properties used as model macromolecules, suggesting that PKCγ activated partly by Ca2+ influx as well as Hsp90 chaperone function were involved in LET-mediated cellular siRNA uptake. Furthermore, LET with siRNA induced activation of Rho GTPase via Hsp90 and PKC, which could contribute to cellular siRNA uptake accompanied by actin cytoskeleton remodeling. Collectively, our results suggested that LET-induced Rho GTPase activation via Hsp90 and PKC would participate in actin-dependent cellular uptake of siRNA.
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Chen Z, Kapus A, Khatri I, Kos O, Zhu F, Gorczynski RM. Cell membrane-bound CD200 signals both via an extracellular domain and following nuclear translocation of a cytoplasmic fragment. Leuk Res 2018; 69:72-80. [DOI: 10.1016/j.leukres.2018.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/02/2018] [Accepted: 04/06/2018] [Indexed: 12/16/2022]
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Pylro VS, Oliveira FS, Morais DK, Cuadros-Orellana S, Pais FSM, Medeiros JD, Geraldo JA, Gilbert J, Volpini AC, Fernandes GR. ZIKV - CDB: A Collaborative Database to Guide Research Linking SncRNAs and ZIKA Virus Disease Symptoms. PLoS Negl Trop Dis 2016; 10:e0004817. [PMID: 27332714 PMCID: PMC4917180 DOI: 10.1371/journal.pntd.0004817] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/07/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In early 2015, a ZIKA Virus (ZIKV) infection outbreak was recognized in northeast Brazil, where concerns over its possible links with infant microcephaly have been discussed. Providing a causal link between ZIKV infection and birth defects is still a challenge. MicroRNAs (miRNAs) are small noncoding RNAs (sncRNAs) that regulate post-transcriptional gene expression by translational repression, and play important roles in viral pathogenesis and brain development. The potential for flavivirus-mediated miRNA signalling dysfunction in brain-tissue development provides a compelling hypothesis to test the perceived link between ZIKV and microcephaly. METHODOLOGY/PRINCIPAL FINDINGS Here, we applied in silico analyses to provide novel insights to understand how Congenital ZIKA Syndrome symptoms may be related to an imbalance in miRNAs function. Moreover, following World Health Organization (WHO) recommendations, we have assembled a database to help target investigations of the possible relationship between ZIKV symptoms and miRNA-mediated human gene expression. CONCLUSIONS/SIGNIFICANCE We have computationally predicted both miRNAs encoded by ZIKV able to target genes in the human genome and cellular (human) miRNAs capable of interacting with ZIKV genomes. Our results represent a step forward in the ZIKV studies, providing new insights to support research in this field and identify potential targets for therapy.
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Affiliation(s)
- Victor Satler Pylro
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Francislon Silva Oliveira
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Daniel Kumazawa Morais
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Sara Cuadros-Orellana
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Fabiano Sviatopolk-Mirsky Pais
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Julliane Dutra Medeiros
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Juliana Assis Geraldo
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Jack Gilbert
- Department of Ecology and Evolution, The University of Chicago, Chicago, Illinois, United States of America
- Argonne National Laboratory, Institute for Genomic and Systems Biology, Argonne, Illinois, United States of America
- Department of Surgery, The University of Chicago, Chicago, Illinois, United States of America
| | - Angela Cristina Volpini
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Gabriel Rocha Fernandes
- Biosystems Informatics and Genomics Group, René Rachou Research Center (CPqRR-FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
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14
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Takenaka N, Nihata Y, Satoh T. Rac1 Activation Caused by Membrane Translocation of a Guanine Nucleotide Exchange Factor in Akt2-Mediated Insulin Signaling in Mouse Skeletal Muscle. PLoS One 2016; 11:e0155292. [PMID: 27163697 PMCID: PMC4862641 DOI: 10.1371/journal.pone.0155292] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/27/2016] [Indexed: 11/25/2022] Open
Abstract
Insulin-stimulated glucose uptake in skeletal muscle is mediated by the glucose transporter GLUT4, which is translocated to the plasma membrane following insulin stimulation. Several lines of evidence suggested that the protein kinase Akt2 plays a key role in this insulin action. The small GTPase Rac1 has also been implicated as a regulator of insulin-stimulated GLUT4 translocation, acting downstream of Akt2. However, the mechanisms whereby Akt2 regulates Rac1 activity remain obscure. The guanine nucleotide exchange factor FLJ00068 has been identified as a direct regulator of Rac1 in Akt2-mediated signaling, but its characterization was performed mostly in cultured myoblasts. Here, we provide in vivo evidence that FLJ00068 indeed acts downstream of Akt2 as a Rac1 regulator by using mouse skeletal muscle. Small interfering RNA knockdown of FLJ00068 markedly diminished GLUT4 translocation to the sarcolemma following insulin administration or ectopic expression of a constitutively activated mutant of either phosphoinositide 3-kinase or Akt2. Additionally, insulin and these constitutively activated mutants caused the activation of Rac1 as shown by immunofluorescent microscopy using a polypeptide probe specific to activated Rac1 in isolated gastrocnemius muscle fibers and frozen sections of gastrocnemius muscle. This Rac1 activation was also abrogated by FLJ00068 knockdown. Furthermore, we observed translocation of FLJ00068 to the cell periphery following insulin stimulation in cultured myoblasts. Localization of FLJ00068 in the plasma membrane in insulin-stimulated, but not unstimulated, myoblasts and mouse gastrocnemius muscle was further affirmed by subcellular fractionation and subsequent immunoblotting. Collectively, these results strongly support a critical role of FLJ00068 in Akt2-mediated Rac1 activation in mouse skeletal muscle insulin signaling.
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Affiliation(s)
- Nobuyuki Takenaka
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Yuma Nihata
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Takaya Satoh
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, Japan
- * E-mail:
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15
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DeGeer J, Kaplan A, Mattar P, Morabito M, Stochaj U, Kennedy TE, Debant A, Cayouette M, Fournier AE, Lamarche-Vane N. Hsc70 chaperone activity underlies Trio GEF function in axon growth and guidance induced by netrin-1. J Cell Biol 2015; 210:817-32. [PMID: 26323693 PMCID: PMC4555821 DOI: 10.1083/jcb.201505084] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During development, netrin-1 is both an attractive and repulsive axon guidance cue and mediates its attractive function through the receptor Deleted in Colorectal Cancer (DCC). The activation of Rho guanosine triphosphatases within the extending growth cone facilitates the dynamic reorganization of the cytoskeleton required to drive axon extension. The Rac1 guanine nucleotide exchange factor (GEF) Trio is essential for netrin-1-induced axon outgrowth and guidance. Here, we identify the molecular chaperone heat shock cognate protein 70 (Hsc70) as a novel Trio regulator. Hsc70 dynamically associated with the N-terminal region and Rac1 GEF domain of Trio. Whereas Hsc70 expression supported Trio-dependent Rac1 activation, adenosine triphosphatase-deficient Hsc70 (D10N) abrogated Trio Rac1 GEF activity and netrin-1-induced Rac1 activation. Hsc70 was required for netrin-1-mediated axon growth and attraction in vitro, whereas Hsc70 activity supported callosal projections and radial neuronal migration in the embryonic neocortex. These findings demonstrate that Hsc70 chaperone activity is required for Rac1 activation by Trio and this function underlies netrin-1/DCC-dependent axon outgrowth and guidance.
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Affiliation(s)
- Jonathan DeGeer
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - Andrew Kaplan
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Pierre Mattar
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Morgane Morabito
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Timothy E Kennedy
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Anne Debant
- Centre de Recherche de Biochimie Macromoléculaire, Centre National de la Recherche Scientifique, UMR5237, University of Montpellier, Montpellier 34293, France
| | - Michel Cayouette
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada Department of Medicine, Université de Montréal, Montreal, Quubec H3T 1J4, Canada
| | - Alyson E Fournier
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Nathalie Lamarche-Vane
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
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16
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Petsakou A, Sapsis TP, Blau J. Circadian Rhythms in Rho1 Activity Regulate Neuronal Plasticity and Network Hierarchy. Cell 2015; 162:823-35. [PMID: 26234154 DOI: 10.1016/j.cell.2015.07.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 03/19/2015] [Accepted: 06/13/2015] [Indexed: 01/02/2023]
Abstract
Neuronal plasticity helps animals learn from their environment. However, it is challenging to link specific changes in defined neurons to altered behavior. Here, we focus on circadian rhythms in the structure of the principal s-LNv clock neurons in Drosophila. By quantifying neuronal architecture, we observed that s-LNv structural plasticity changes the amount of axonal material in addition to cycles of fasciculation and defasciculation. We found that this is controlled by rhythmic Rho1 activity that retracts s-LNv axonal termini by increasing myosin phosphorylation and simultaneously changes the balance of pre-synaptic and dendritic markers. This plasticity is required to change clock network hierarchy and allow seasonal adaptation. Rhythms in Rho1 activity are controlled by clock-regulated transcription of Puratrophin-1-like (Pura), a Rho1 GEF. Since spinocerebellar ataxia is associated with mutations in human Puratrophin-1, our data support the idea that defective actin-related plasticity underlies this ataxia.
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Affiliation(s)
- Afroditi Petsakou
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Themistoklis P Sapsis
- Courant Institute for Applied Mathematics, New York University, New York, NY 10003, USA; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Justin Blau
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA; Center for Genomics & Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates; Program in Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
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17
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van Buul JD, Geerts D, Huveneers S. Rho GAPs and GEFs: controling switches in endothelial cell adhesion. Cell Adh Migr 2015; 8:108-24. [PMID: 24622613 PMCID: PMC4049857 DOI: 10.4161/cam.27599] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Within blood vessels, endothelial cell–cell and cell–matrix adhesions are crucial to preserve barrier function, and these adhesions are tightly controlled during vascular development, angiogenesis, and transendothelial migration of inflammatory cells. Endothelial cellular signaling that occurs via the family of Rho GTPases coordinates these cell adhesion structures through cytoskeletal remodelling. In turn, Rho GTPases are regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). To understand how endothelial cells initiate changes in the activity of Rho GTPases, and thereby regulate cell adhesion, we will discuss the role of Rho GAPs and GEFs in vascular biology. Many potentially important Rho regulators have not been studied in detail in endothelial cells. We therefore will first overview which GAPs and GEFs are highly expressed in endothelium, based on comparative gene expression analysis of human endothelial cells compared with other tissue cell types. Subsequently, we discuss the relevance of Rho GAPs and GEFs for endothelial cell adhesion in vascular homeostasis and disease.
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Affiliation(s)
- Jaap D van Buul
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
| | - Dirk Geerts
- Department of Pediatric Oncology/Hematology; Erasmus University Medical Center; Rotterdam, The Netherlands
| | - Stephan Huveneers
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
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18
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Pérez-Coria M, Lugo-Trampe JJ, Zamudio-Osuna M, Rodríguez-Sánchez IP, Lugo-Trampe A, de la Fuente-Cortez B, Campos-Acevedo LD, Martínez-de-Villarreal LE. Identification of novel mutations in Mexican patients with Aarskog-Scott syndrome. Mol Genet Genomic Med 2015; 3:197-202. [PMID: 26029706 PMCID: PMC4444161 DOI: 10.1002/mgg3.132] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/30/2014] [Accepted: 01/08/2015] [Indexed: 12/25/2022] Open
Abstract
Aarskog-Scott syndrome (AAS), also known as faciogenital dysplasia (FGD, OMIM # 305400), is an X-linked disorder of recessive inheritance, characterized by short stature and facial, skeletal, and urogenital abnormalities. AAS is caused by mutations in the FGD1 gene (Xp11.22), with over 56 different mutations identified to date. We present the clinical and molecular analysis of four unrelated families of Mexican origin with an AAS phenotype, in whom FGD1 sequencing was performed. This analysis identified two stop mutations not previously reported in the literature: p.Gln664* and p.Glu380*. Phenotypically, every male patient met the clinical criteria of the syndrome, whereas discrepancies were found between phenotypes in female patients. Our results identify two novel mutations in FGD1, broadening the spectrum of reported mutations; and provide further delineation of the phenotypic variability previously described in AAS.
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Affiliation(s)
- Mariana Pérez-Coria
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - José J Lugo-Trampe
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - Michell Zamudio-Osuna
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - Iram P Rodríguez-Sánchez
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - Angel Lugo-Trampe
- Centro Mesoamericano de Estudios en Salud Pública y Desastres, Universidad Autónoma de Chiapas (UNACH) Tapachula, Chis, México
| | - Beatriz de la Fuente-Cortez
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - Luis D Campos-Acevedo
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
| | - Laura E Martínez-de-Villarreal
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL) Monterrey, Nuevo Leon, México
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19
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Regulating Rac in the nervous system: molecular function and disease implication of Rac GEFs and GAPs. BIOMED RESEARCH INTERNATIONAL 2015; 2015:632450. [PMID: 25879033 PMCID: PMC4388020 DOI: 10.1155/2015/632450] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/06/2015] [Indexed: 12/11/2022]
Abstract
Rho family GTPases, including RhoA, Rac1, and Cdc42 as the most studied members, are master regulators of actin cytoskeletal organization. Rho GTPases control various aspects of the nervous system and are associated with a number of neuropsychiatric and neurodegenerative diseases. The activity of Rho GTPases is controlled by two families of regulators, guanine nucleotide exchange factors (GEFs) as the activators and GTPase-activating proteins (GAPs) as the inhibitors. Through coordinated regulation by GEFs and GAPs, Rho GTPases act as converging signaling molecules that convey different upstream signals in the nervous system. So far, more than 70 members of either GEFs or GAPs of Rho GTPases have been identified in mammals, but only a small subset of them have well-known functions. Thus, characterization of important GEFs and GAPs in the nervous system is crucial for the understanding of spatiotemporal dynamics of Rho GTPase activity in different neuronal functions. In this review, we summarize the current understanding of GEFs and GAPs for Rac1, with emphasis on the molecular function and disease implication of these regulators in the nervous system.
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20
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Role of the guanine nucleotide exchange factor in Akt2-mediated plasma membrane translocation of GLUT4 in insulin-stimulated skeletal muscle. Cell Signal 2014; 26:2460-9. [DOI: 10.1016/j.cellsig.2014.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/09/2014] [Indexed: 11/23/2022]
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21
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Satoh T. Molecular mechanisms for the regulation of insulin-stimulated glucose uptake by small guanosine triphosphatases in skeletal muscle and adipocytes. Int J Mol Sci 2014; 15:18677-92. [PMID: 25325535 PMCID: PMC4227239 DOI: 10.3390/ijms151018677] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/28/2014] [Accepted: 09/30/2014] [Indexed: 12/11/2022] Open
Abstract
Insulin is a hormone that regulates the blood glucose level by stimulating various physiological responses in its target tissues. In skeletal muscle and adipose tissue, insulin promotes membrane trafficking of the glucose transporter GLUT4 from GLUT4 storage vesicles to the plasma membrane, thereby facilitating the uptake of glucose from the circulation. Detailed mechanisms underlying insulin-dependent intracellular signal transduction for glucose uptake remain largely unknown. In this article, I give an overview on the recently identified signaling network involving Rab, Ras, and Rho family small guanosine triphosphatases (GTPases) that regulates glucose uptake in insulin-responsive tissues. In particular, the regulatory mechanisms for these small GTPases and the cross-talk between protein kinase and small GTPase cascades are highlighted.
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Affiliation(s)
- Takaya Satoh
- Laboratory of Cell Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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22
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Droppelmann CA, Campos-Melo D, Volkening K, Strong MJ. The emerging role of guanine nucleotide exchange factors in ALS and other neurodegenerative diseases. Front Cell Neurosci 2014; 8:282. [PMID: 25309324 PMCID: PMC4159981 DOI: 10.3389/fncel.2014.00282] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/25/2014] [Indexed: 12/11/2022] Open
Abstract
Small GTPases participate in a broad range of cellular processes such as proliferation, differentiation, and migration. The exchange of GDP for GTP resulting in the activation of these GTPases is catalyzed by a group of enzymes called guanine nucleotide exchange factors (GEFs), of which two classes: Dbl-related exchange factors and the more recently described dedicator of cytokinesis proteins family exchange factors. Increasingly, deregulation of normal GEF activity or function has been associated with a broad range of disease states, including neurodegeneration and neurodevelopmental disorders. In this review, we examine this evidence with special emphasis on the novel role of Rho guanine nucleotide exchange factor (RGNEF/p190RhoGEF) in the pathogenesis of amyotrophic lateral sclerosis. RGNEF is the first neurodegeneration-linked GEF that regulates not only RhoA GTPase activation but also functions as an RNA binding protein that directly acts with low molecular weight neurofilament mRNA 3' untranslated region to regulate its stability. This dual role for RGNEF, coupled with the increasing understanding of the key role for GEFs in modulating the GTPase function in cell survival suggests a prominent role for GEFs in mediating a critical balance between cytotoxicity and neuroprotection which, when disturbed, contributes to neuronal loss.
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Affiliation(s)
- Cristian A Droppelmann
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada
| | - Danae Campos-Melo
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada
| | - Kathryn Volkening
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada ; Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University London, ON, Canada
| | - Michael J Strong
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada ; Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University London, ON, Canada
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