1
|
Lamb FS, Choi H, Miller MR, Stark RJ. Vascular Inflammation and Smooth Muscle Contractility: The Role of Nox1-Derived Superoxide and LRRC8 Anion Channels. Hypertension 2024; 81:752-763. [PMID: 38174563 PMCID: PMC10954410 DOI: 10.1161/hypertensionaha.123.19434] [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] [Indexed: 01/05/2024]
Abstract
Vascular inflammation underlies the development of hypertension, and the mechanisms by which it increases blood pressure remain the topic of intense investigation. Proinflammatory factors including glucose, salt, vasoconstrictors, cytokines, wall stress, and growth factors enhance contractility and impair relaxation of vascular smooth muscle cells. These pathways share a dependence upon redox signaling, and excessive activation promotes oxidative stress that promotes vascular aging. Vascular smooth muscle cell phenotypic switching and migration into the intima contribute to atherosclerosis, while hypercontractility increases systemic vascular resistance and vasospasm that can trigger ischemia. Here, we review factors that drive the initiation and progression of this vasculopathy in vascular smooth muscle cells. Emphasis is placed on the contribution of reactive oxygen species generated by the Nox1 NADPH oxidase which produces extracellular superoxide (O2•-). The mechanisms of O2•- signaling remain poorly defined, but recent evidence demonstrates physical association of Nox1 with leucine-rich repeat containing 8 family volume-sensitive anion channels. These may provide a pathway for influx of O2•- to the cytoplasm, creating an oxidized cytoplasmic nanodomain where redox-based signals can affect both cytoskeletal structure and vasomotor function. Understanding the mechanistic links between inflammation, O2•- and vascular smooth muscle cell contractility may facilitate targeting of anti-inflammatory therapy in hypertension.
Collapse
Affiliation(s)
- Fred S Lamb
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Hyehun Choi
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Michael R Miller
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Ryan J Stark
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| |
Collapse
|
2
|
Choi H, Miller MR, Nguyen HN, Rohrbough JC, Koch SR, Boatwright N, Yarboro MT, Sah R, McDonald WH, Reese JJ, Stark RJ, Lamb FS. LRRC8A anion channels modulate vascular reactivity via association with myosin phosphatase rho interacting protein. FASEB J 2023; 37:e23028. [PMID: 37310356 PMCID: PMC10591482 DOI: 10.1096/fj.202300561r] [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: 03/23/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 06/14/2023]
Abstract
Leucine-rich repeat containing 8A (LRRC8A) volume regulated anion channels (VRACs) are activated by inflammatory and pro-contractile stimuli including tumor necrosis factor alpha (TNFα), angiotensin II and stretch. LRRC8A associates with NADPH oxidase 1 (Nox1) and supports extracellular superoxide production. We tested the hypothesis that VRACs modulate TNFα signaling and vasomotor function in mice lacking LRRC8A exclusively in vascular smooth muscle cells (VSMCs, Sm22α-Cre, Knockout). Knockout (KO) mesenteric vessels contracted normally but relaxation to acetylcholine (ACh) and sodium nitroprusside (SNP) was enhanced compared to wild type (WT). Forty-eight hours of ex vivo exposure to TNFα (10 ng/mL) enhanced contraction to norepinephrine (NE) and markedly impaired dilation to ACh and SNP in WT but not KO vessels. VRAC blockade (carbenoxolone, CBX, 100 μM, 20 min) enhanced dilation of control rings and restored impaired dilation following TNFα exposure. Myogenic tone was absent in KO rings. LRRC8A immunoprecipitation followed by mass spectroscopy identified 33 proteins that interacted with LRRC8A. Among them, the myosin phosphatase rho-interacting protein (MPRIP) links RhoA, MYPT1 and actin. LRRC8A-MPRIP co-localization was confirmed by confocal imaging of tagged proteins, Proximity Ligation Assays, and IP/western blots. siLRRC8A or CBX treatment decreased RhoA activity in VSMCs, and MYPT1 phosphorylation was reduced in KO mesenteries suggesting that reduced ROCK activity contributes to enhanced relaxation. MPRIP was a target of redox modification, becoming oxidized (sulfenylated) after TNFα exposure. Interaction of LRRC8A with MPRIP may allow redox regulation of the cytoskeleton by linking Nox1 activation to impaired vasodilation. This identifies VRACs as potential targets for treatment or prevention of vascular disease.
Collapse
Affiliation(s)
- Hyehun Choi
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michael R Miller
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Hong-Ngan Nguyen
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jeffrey C Rohrbough
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Stephen R Koch
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Naoko Boatwright
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michael T Yarboro
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Rajan Sah
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - W Hayes McDonald
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - J Jeffrey Reese
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ryan J Stark
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Fred S Lamb
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
3
|
Jbara A, Lin KT, Stossel C, Siegfried Z, Shqerat H, Amar-Schwartz A, Elyada E, Mogilevsky M, Raitses-Gurevich M, Johnson JL, Yaron TM, Ovadia O, Jang GH, Danan-Gotthold M, Cantley LC, Levanon EY, Gallinger S, Krainer AR, Golan T, Karni R. RBFOX2 modulates a metastatic signature of alternative splicing in pancreatic cancer. Nature 2023; 617:147-153. [PMID: 36949200 PMCID: PMC10156590 DOI: 10.1038/s41586-023-05820-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/10/2023] [Indexed: 03/24/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDA) is characterized by aggressive local invasion and metastatic spread, leading to high lethality. Although driver gene mutations during PDA progression are conserved, no specific mutation is correlated with the dissemination of metastases1-3. Here we analysed RNA splicing data of a large cohort of primary and metastatic PDA tumours to identify differentially spliced events that correlate with PDA progression. De novo motif analysis of these events detected enrichment of motifs with high similarity to the RBFOX2 motif. Overexpression of RBFOX2 in a patient-derived xenograft (PDX) metastatic PDA cell line drastically reduced the metastatic potential of these cells in vitro and in vivo, whereas depletion of RBFOX2 in primary pancreatic tumour cell lines increased the metastatic potential of these cells. These findings support the role of RBFOX2 as a potent metastatic suppressor in PDA. RNA-sequencing and splicing analysis of RBFOX2 target genes revealed enrichment of genes in the RHO GTPase pathways, suggesting a role of RBFOX2 splicing activity in cytoskeletal organization and focal adhesion formation. Modulation of RBFOX2-regulated splicing events, such as via myosin phosphatase RHO-interacting protein (MPRIP), is associated with PDA metastases, altered cytoskeletal organization and the induction of focal adhesion formation. Our results implicate the splicing-regulatory function of RBFOX2 as a tumour suppressor in PDA and suggest a therapeutic approach for metastatic PDA.
Collapse
Affiliation(s)
- Amina Jbara
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Kuan-Ting Lin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Chani Stossel
- Division of Oncology, Sheba Medical Center Tel Hashomer, Ramat-Gan, Israel
| | - Zahava Siegfried
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Haya Shqerat
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Adi Amar-Schwartz
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ela Elyada
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Maxim Mogilevsky
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | - Jared L Johnson
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Tomer M Yaron
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
- Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Ofek Ovadia
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Gun Ho Jang
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Miri Danan-Gotthold
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Steven Gallinger
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | | | - Talia Golan
- Division of Oncology, Sheba Medical Center Tel Hashomer, Ramat-Gan, Israel
| | - Rotem Karni
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
| |
Collapse
|
4
|
Choi H, Miller MR, Nguyen HN, Rohrbough JC, Koch SR, Boatwright N, Yarboro MT, Sah R, McDonald WH, Reese JJ, Stark RJ, Lamb FS. LRRC8A anion channels modulate vasodilation via association with Myosin Phosphatase Rho Interacting Protein (MPRIP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531807. [PMID: 36945623 PMCID: PMC10028897 DOI: 10.1101/2023.03.08.531807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
BACKGROUND In vascular smooth muscle cells (VSMCs), LRRC8A volume regulated anion channels (VRACs) are activated by inflammatory and pro-contractile stimuli including tumor necrosis factor alpha (TNFα), angiotensin II and stretch. LRRC8A physically associates with NADPH oxidase 1 (Nox1) and supports its production of extracellular superoxide (O 2 -• ). METHODS AND RESULTS Mice lacking LRRC8A exclusively in VSMCs (Sm22α-Cre, KO) were used to assess the role of VRACs in TNFα signaling and vasomotor function. KO mesenteric vessels contracted normally to KCl and phenylephrine, but relaxation to acetylcholine (ACh) and sodium nitroprusside (SNP) was enhanced compared to wild type (WT). 48 hours of ex vivo exposure to TNFα (10ng/ml) markedly impaired dilation to ACh and SNP in WT but not KO vessels. VRAC blockade (carbenoxolone, CBX, 100 μM, 20 min) enhanced dilation of control rings and restored impaired dilation following TNFα exposure. Myogenic tone was absent in KO rings. LRRC8A immunoprecipitation followed by mass spectroscopy identified 35 proteins that interacted with LRRC8A. Pathway analysis revealed actin cytoskeletal regulation as the most closely associated function of these proteins. Among these proteins, the Myosin Phosphatase Rho-Interacting protein (MPRIP) links RhoA, MYPT1 and actin. LRRC8A-MPRIP co-localization was confirmed by confocal imaging of tagged proteins, Proximity Ligation Assays, and IP/western blots which revealed LRRC8A binding at the second Pleckstrin Homology domain of MPRIP. siLRRC8A or CBX treatment decreased RhoA activity in cultured VSMCs, and MYPT1 phosphorylation at T853 was reduced in KO mesenteries suggesting that reduced ROCK activity contributes to enhanced relaxation. MPRIP was a target of redox modification, becoming oxidized (sulfenylated) after TNFα exposure. CONCLUSIONS Interaction of Nox1/LRRC8A with MPRIP/RhoA/MYPT1/actin may allow redox regulation of the cytoskeleton and link Nox1 activation to both inflammation and vascular contractility.
Collapse
|
5
|
Wang D, Gu L, Zheng J, Zhang Q, Xu Q, Li R, Song D, Ha C, Zhang Q, Yin H, Xu M, Wang H, Li W, Yuan Z, Yang C, Gu M. Germline VWF/MPRIP and somatoplasm FGA variants synergically confer susceptibility to non-traumatic osteonecrosis of the femoral head. Sci Rep 2023; 13:3112. [PMID: 36813871 PMCID: PMC9946931 DOI: 10.1038/s41598-023-30260-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
Non-traumatic osteonecrosis of the femoral head (ONFH) relies on multiple pathogenic factors, including intravascular coagulation, osteoporosis and lipid metabolism disorders. Despite extensively explored from various aspects, genetic mechanism underlying non-traumatic ONFH has not been fully elucidated. We randomly collected blood and necrotic tissue samples from 32 patients with non-traumatic ONFH as well as blood samples from 30 healthy individuals for whole exome sequencing (WES). Germline mutation and somatic mutation were analyzed to identify new potential pathogenic genes responsible for non-traumatic ONFH. Three genes might correlate with non-traumatic ONFH: VWF, MPRIP (germline mutations) and FGA (somatic mutations). Germline or somatic mutations in VWF, MPRIP and FGA correlate with intravascular coagulation, thrombosis, and consequently, ischemic necrosis of the femoral head.
Collapse
Affiliation(s)
- Dawei Wang
- Department of Orthopedic Surgery, Liaocheng People's Hospital, Liaocheng, 252000, Shandong, China.
| | - Longchao Gu
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Juan Zheng
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Qiang Zhang
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Qi Xu
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Rongrong Li
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Da Song
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Chengzhi Ha
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Qianqian Zhang
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Han Yin
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Mingtao Xu
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Hongmin Wang
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Wei Li
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Zhengfeng Yuan
- grid.415912.a0000 0004 4903 149XDepartment of Orthopedic Surgery, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Cuncun Yang
- grid.415912.a0000 0004 4903 149XJoint Laboratory for Translational Medicine Research, Liaocheng People’s Hospital, Liaocheng, 252000 Shandong China
| | - Mingliang Gu
- Joint Laboratory for Translational Medicine Research, Liaocheng People's Hospital, Liaocheng, 252000, Shandong, China.
| |
Collapse
|
6
|
Rabaglino MB, Wakabayashi M, Pearson JT, Jensen LJ. Effect of age on the vascular proteome in middle cerebral arteries and mesenteric resistance arteries in mice. Mech Ageing Dev 2021; 200:111594. [PMID: 34756926 DOI: 10.1016/j.mad.2021.111594] [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: 05/05/2021] [Revised: 10/11/2021] [Accepted: 10/26/2021] [Indexed: 10/20/2022]
Abstract
Aging is associated with hypertension and brain blood flow dysregulation, which are major risk factors for cardiovascular and neurodegenerative diseases. Structural remodeling, endothelial dysfunction, or hypercontractility of resistance vessels may cause increased total peripheral resistance and hypertension. Recent studies showed that G protein- and RhoA/Rho-kinase pathways are involved in increased mean arterial pressure (MAP) and arterial tone in middle-aged mice. We aimed to characterize the age-dependent changes in the vascular proteome in normal laboratory mice using mass spectrometry and bioinformatics analyses on middle cerebral arteries and mesenteric resistance arteries from young (3 months) vs. middle-aged (14 months) mice. In total, 31 proteins were significantly affected by age whereas 172 proteins were differentially expressed by vessel type. Hierarchical clustering revealed that 207 proteins were significantly changed or clustered by age. Vitamin B6 pathway, Biosynthesis of antibiotics, Regulation of actin cytoskeleton and Endocytosis were the top enriched KEGG pathways by age. Several proteins in the RhoA/Rho-kinase pathway changed in a manner consistent with hypertension and dysregulation of cerebral perfusion. Although aging had a less profound effect than vessel type on the resistance artery proteome, regulation of actin cytoskeleton, including the RhoA/Rho-kinase pathway, is an important target for age-dependent hypertension.
Collapse
Affiliation(s)
- Maria Belen Rabaglino
- Dept. of Applied Mathematics and Computer Science, Danish Technical University, Denmark
| | - Masaki Wakabayashi
- Omics Research Center, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - James Todd Pearson
- Dept. of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Lars Jørn Jensen
- Dept. of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
| |
Collapse
|
7
|
Maeso-Alonso L, López-Ferreras L, Marques MM, Marin MC. p73 as a Tissue Architect. Front Cell Dev Biol 2021; 9:716957. [PMID: 34368167 PMCID: PMC8343074 DOI: 10.3389/fcell.2021.716957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/28/2021] [Indexed: 12/13/2022] Open
Abstract
The TP73 gene belongs to the p53 family comprised by p53, p63, and p73. In response to physiological and pathological signals these transcription factors regulate multiple molecular pathways which merge in an ensemble of interconnected networks, in which the control of cell proliferation and cell death occupies a prominent position. However, the complex phenotype of the Trp73 deficient mice has revealed that the biological relevance of this gene does not exclusively rely on its growth suppression effects, but it is also intertwined with other fundamental roles governing different aspects of tissue physiology. p73 function is essential for the organization and homeostasis of different complex microenvironments, like the neurogenic niche, which supports the neural progenitor cells and the ependyma, the male and female reproductive organs, the respiratory epithelium or the vascular network. We propose that all these, apparently unrelated, developmental roles, have a common denominator: p73 function as a tissue architect. Tissue architecture is defined by the nature and the integrity of its cellular and extracellular compartments, and it is based on proper adhesive cell-cell and cell-extracellular matrix interactions as well as the establishment of cellular polarity. In this work, we will review the current understanding of p73 role as a neurogenic niche architect through the regulation of cell adhesion, cytoskeleton dynamics and Planar Cell Polarity, and give a general overview of TAp73 as a hub modulator of these functions, whose alteration could impinge in many of the Trp73 -/- phenotypes.
Collapse
Affiliation(s)
- Laura Maeso-Alonso
- Departamento de Biología Molecular, Instituto de Biomedicina (IBIOMED), University of León, León, Spain
| | - Lorena López-Ferreras
- Departamento de Biología Molecular, Instituto de Biomedicina (IBIOMED), University of León, León, Spain
| | - Margarita M Marques
- Departamento de Producción Animal, Instituto de Desarrollo Ganadero y Sanidad Animal, University of León, León, Spain
| | - Maria C Marin
- Departamento de Biología Molecular, Instituto de Biomedicina (IBIOMED), University of León, León, Spain
| |
Collapse
|
8
|
The lysosomal Ragulator complex plays an essential role in leukocyte trafficking by activating myosin II. Nat Commun 2021; 12:3333. [PMID: 34099704 PMCID: PMC8184920 DOI: 10.1038/s41467-021-23654-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/27/2021] [Indexed: 12/14/2022] Open
Abstract
Lysosomes are involved in nutrient sensing via the mechanistic target of rapamycin complex 1 (mTORC1). mTORC1 is tethered to lysosomes by the Ragulator complex, a heteropentamer in which Lamtor1 wraps around Lamtor2–5. Although the Ragulator complex is required for cell migration, the mechanisms by which it participates in cell motility remain unknown. Here, we show that lysosomes move to the uropod in motile cells, providing the platform where Lamtor1 interacts with the myosin phosphatase Rho-interacting protein (MPRIP) independently of mTORC1 and interferes with the interaction between MPRIP and MYPT1, a subunit of myosin light chain phosphatase (MLCP), thereby increasing myosin II–mediated actomyosin contraction. Additionally, formation of the complete Ragulator complex is required for leukocyte migration and pathophysiological immune responses. Together, our findings demonstrate that the lysosomal Ragulator complex plays an essential role in leukocyte migration by activating myosin II through interacting with MPRIP. Myosin II–mediated contractility is required for leukocyte migration. Here, authors show that lysosomes are involved in leukocyte migration by providing the platform where Ragulator complex interacts with the myosin phosphatase Rho-interacting protein (MPRIP) independently of mTORC1 and interferes with the interaction between MPRIP and a subunit of myosin light chain phosphatase (MLCP).
Collapse
|
9
|
The F-Actin-Binding MPRIP Forms Phase-Separated Condensates and Associates with PI(4,5)P2 and Active RNA Polymerase II in the Cell Nucleus. Cells 2021; 10:cells10040848. [PMID: 33918018 PMCID: PMC8068864 DOI: 10.3390/cells10040848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 12/14/2022] Open
Abstract
Here, we provide evidence for the presence of Myosin phosphatase rho-interacting protein (MPRIP), an F-actin-binding protein, in the cell nucleus. The MPRIP protein binds to Phosphatidylinositol 4,5-bisphosphate (PIP2) and localizes to the nuclear speckles and nuclear lipid islets which are known to be involved in transcription. We identified MPRIP as a component of RNA Polymerase II/Nuclear Myosin 1 complex and showed that MPRIP forms phase-separated condensates which are able to bind nuclear F-actin fibers. Notably, the fibrous MPRIP preserves its liquid-like properties and reforms the spherical shaped condensates when F-actin is disassembled. Moreover, we show that the phase separation of MPRIP is driven by its long intrinsically disordered region at the C-terminus. We propose that the PIP2/MPRIP association might contribute to the regulation of RNAPII transcription via phase separation and nuclear actin polymerization.
Collapse
|
10
|
Lavanderos B, Silva I, Cruz P, Orellana-Serradell O, Saldías MP, Cerda O. TRP Channels Regulation of Rho GTPases in Brain Context and Diseases. Front Cell Dev Biol 2020; 8:582975. [PMID: 33240883 PMCID: PMC7683514 DOI: 10.3389/fcell.2020.582975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
Neurological and neuropsychiatric disorders are mediated by several pathophysiological mechanisms, including developmental and degenerative abnormalities caused primarily by disturbances in cell migration, structural plasticity of the synapse, and blood-vessel barrier function. In this context, critical pathways involved in the pathogenesis of these diseases are related to structural, scaffolding, and enzymatic activity-bearing proteins, which participate in Ca2+- and Ras Homologs (Rho) GTPases-mediated signaling. Rho GTPases are GDP/GTP binding proteins that regulate the cytoskeletal structure, cellular protrusion, and migration. These proteins cycle between GTP-bound (active) and GDP-bound (inactive) states due to their intrinsic GTPase activity and their dynamic regulation by GEFs, GAPs, and GDIs. One of the most important upstream inputs that modulate Rho GTPases activity is Ca2+ signaling, positioning ion channels as pivotal molecular entities for Rho GTPases regulation. Multiple non-selective cationic channels belonging to the Transient Receptor Potential (TRP) family participate in cytoskeletal-dependent processes through Ca2+-mediated modulation of Rho GTPases. Moreover, these ion channels have a role in several neuropathological events such as neuronal cell death, brain tumor progression and strokes. Although Rho GTPases-dependent pathways have been extensively studied, how they converge with TRP channels in the development or progression of neuropathologies is poorly understood. Herein, we review recent evidence and insights that link TRP channels activity to downstream Rho GTPase signaling or modulation. Moreover, using the TRIP database, we establish associations between possible mediators of Rho GTPase signaling with TRP ion channels. As such, we propose mechanisms that might explain the TRP-dependent modulation of Rho GTPases as possible pathways participating in the emergence or maintenance of neuropathological conditions.
Collapse
Affiliation(s)
- Boris Lavanderos
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Ian Silva
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Pablo Cruz
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Octavio Orellana-Serradell
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - María Paz Saldías
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Oscar Cerda
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile.,The Wound Repair, Treatment and Health (WoRTH) Initiative, Santiago, Chile
| |
Collapse
|
11
|
Coelho NM, Wang A, Petrovic P, Wang Y, Lee W, McCulloch CA. MRIP Regulates the Myosin IIA Activity and DDR1 Function to Enable Collagen Tractional Remodeling. Cells 2020; 9:cells9071672. [PMID: 32664526 PMCID: PMC7407560 DOI: 10.3390/cells9071672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 12/18/2022] Open
Abstract
DDR1 is a collagen adhesion-mechanoreceptor expressed in fibrotic lesions. DDR1 mediates non-muscle myosin IIA (NMIIA)-dependent collagen remodeling. We discovered that the myosin phosphatase Rho-interacting protein (MRIP), is enriched in DDR1-NMIIA adhesions on collagen. MRIP regulates RhoA- and myosin phosphatase-dependent myosin activity. We hypothesized that MRIP regulates DDR1-NMIIA interactions to enable cell migration and collagen tractional remodeling. After deletion of MRIP in β1-integrin null cells expressing DDR1, in vitro wound closure, collagen realignment, and contraction were reduced. Cells expressing DDR1 and MRIP formed larger and more abundant DDR1 clusters on collagen than cells cultured on fibronectin or cells expressing DDR1 but null for MRIP or cells expressing a non-activating DDR1 mutant. Deletion of MRIP reduced DDR1 autophosphorylation and blocked myosin light chain-dependent contraction. Deletion of MRIP did not disrupt the association of DDR1 with NMIIA. We conclude that MRIP regulates NMIIA-dependent DDR1 cluster growth and activation. Accordingly, MRIP may provide a novel drug target for dysfunctional DDR1-related collagen tractional remodeling in fibrosis.
Collapse
|
12
|
Wang S, Wang T, Liu T, Xie RG, Zhao XH, Wang L, Yang Q, Jia LT, Han J. Ermin is a p116 RIP -interacting protein promoting oligodendroglial differentiation and myelin maintenance. Glia 2020; 68:2264-2276. [PMID: 32530539 DOI: 10.1002/glia.23838] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/21/2022]
Abstract
Myelin sheaths, which insulate the axons and ensure saltatory conduction of the nerve impulse, are generated and maintained via largely uncharacterized mechanisms. Ermin is an oligodendrocyte-specific protein associated with the cytoskeleton, but how it regulates cytoskeletal remodeling during oligodendrocyte differentiation and its role in myelin maintenance are not clear. To address this, we generated mice constitutively deficient for Ermn, the Ermin-coding gene. We found that aged Ermn-knockout mice exhibit an aberrant myelin architecture, with splitting of myelin layers, peeling of the myelin sheath from axons, and breakdown of myelinated fibers. As a result, these mice had remarkably impaired motor coordination. Ermn knockout also accelerated cuprizone-induced demyelination and exacerbated the associated movement disorders. Ermin was found to contribute to oligodendrocyte morphogenesis by associating with the myosin phosphatase Rho interacting protein (Mprip/p116RIP ) and inactivating RhoA, a GTPase that controls cytoskeletal rearrangement in differentiating cells. These findings provide novel insights into the mechanisms regulating oligodendroglial differentiation, the maintenance of the myelin sheaths, and remyelination.
Collapse
Affiliation(s)
- Shan Wang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Tao Wang
- Department of Neurology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Tao Liu
- Key Laboratory of Modern Teaching Technology, Shaanxi Normal University, Xi'an, China
| | - Rou-Gang Xie
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, China
| | - Xiang-Hui Zhao
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, China
| | - Lei Wang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Qian Yang
- Department of Neurology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Lin-Tao Jia
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Jing Han
- Key Laboratory of Modern Teaching Technology, Shaanxi Normal University, Xi'an, China
| |
Collapse
|
13
|
Wang L, Chitano P, Seow CY. Mechanopharmacology of Rho-kinase antagonism in airway smooth muscle and potential new therapy for asthma. Pharmacol Res 2020; 159:104995. [PMID: 32534100 DOI: 10.1016/j.phrs.2020.104995] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/20/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023]
Abstract
The principle of mechanopharmacology of airway smooth muscle (ASM) is based on the premise that physical agitation, such as pressure oscillation applied to an airway, is able to induce bronchodilation by reducing contractility and softening the cytoskeleton of ASM. Although the underlying mechanism is not entirely clear, there is evidence to suggest that large-amplitude stretches are able to disrupt the actomyosin interaction in the crossbridge cycle and weaken the cytoskeleton in ASM cells. Rho-kinase is known to enhance force generation and strengthen structural integrity of the cytoskeleton during smooth muscle activation and plays a key role in the maintenance of force during prolonged muscle contractions. Synergy in relaxation has been observed when the muscle is subject to oscillatory length change while Rho-kinase is pharmacologically inhibited. In this review, inhibition of Rho-kinase coupled to therapeutic pressure oscillation applied to the airways is explored as a combination treatment for asthma.
Collapse
Affiliation(s)
- Lu Wang
- The Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Canada.
| | - Pasquale Chitano
- The Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Canada
| | - Chun Y Seow
- The Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Canada
| |
Collapse
|
14
|
Asian Zika Virus Isolate Significantly Changes the Transcriptional Profile and Alternative RNA Splicing Events in a Neuroblastoma Cell Line. Viruses 2020; 12:v12050510. [PMID: 32380717 PMCID: PMC7290316 DOI: 10.3390/v12050510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/27/2020] [Indexed: 12/18/2022] Open
Abstract
The alternative splicing of pre-mRNAs expands a single genetic blueprint to encode multiple, functionally diverse protein isoforms. Viruses have previously been shown to interact with, depend on, and alter host splicing machinery. The consequences, however, incited by viral infection on the global alternative slicing (AS) landscape are under-appreciated. Here, we investigated the transcriptional and alternative splicing profile of neuronal cells infected with a contemporary Puerto Rican Zika virus (ZIKVPR) isolate, an isolate of the prototypical Ugandan ZIKV (ZIKVMR), and dengue virus 2 (DENV2). Our analyses revealed that ZIKVPR induced significantly more differential changes in expressed genes compared to ZIKVMR or DENV2, despite all three viruses showing equivalent infectivity and viral RNA levels. Consistent with the transcriptional profile, ZIKVPR induced a higher number of alternative splicing events compared to ZIKVMR or DENV2, and gene ontology analyses highlighted alternative splicing changes in genes associated with mRNA splicing. In summary, we show that ZIKV affects cellular RNA homeostasis not only at the transcriptional levels but also through the alternative splicing of cellular transcripts. These findings could provide new molecular insights into the neuropathologies associated with this virus.
Collapse
|
15
|
Igarashi N, Honjo M, Fujishiro T, Toyono T, Ono T, Mori Y, Miyata K, Obinata H, Aihara M. Activation of the Sphingosine 1 Phosphate-Rho Pathway in Pterygium and in Ultraviolet-Irradiated Normal Conjunctiva. Int J Mol Sci 2019; 20:ijms20194670. [PMID: 31547113 PMCID: PMC6801701 DOI: 10.3390/ijms20194670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 01/05/2023] Open
Abstract
Sphingosine 1 phosphate (S1P) is a bioactive lipid that regulates cellular activity, including proliferation, cytoskeletal organization, migration, and fibrosis. In this study, the potential relevance of S1P–Rho signaling in pterygium formation and the effects of ultraviolet (UV) irradiation on activation of the S1P/S1P receptor axis and fibrotic responses were investigated in vitro. Expressions of the S1P2, S1P4, and S1P5 receptors were significantly higher in pterygium tissue than in normal conjunctiva, and the concentration of S1P was significantly elevated in the lysate of normal conjunctival fibroblast cell (NCFC) irradiated with UV (UV-NCFCs). RhoA activity was significantly upregulated in pterygium fibroblast cells (PFCs) and UV-NCFCs, and myosin phosphatase–Rho interacting protein (MRIP) was upregulated, and myosin phosphatase target subunit 1 (MYPT1) was downregulated in PFCs. Fibrogenic changes were significantly upregulated in both PFCs and UV-NCFCs compared to NCFCs. We found that the activation of the S1P receptor–Rho cascade was observed in pterygium tissue. Additionally, in vitro examination showed S1P–rho activation and fibrogenic changes in PFCs and UV-NCFCs. S1P elevation and the resulting upregulation of the downstream Rho signaling pathway may be important in pterygium formation; this pathway offers a potential therapeutic target for suppressing pterygium generation.
Collapse
Affiliation(s)
- Nozomi Igarashi
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Megumi Honjo
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Takashi Fujishiro
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Tetsuya Toyono
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Takashi Ono
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
- Miyata eye hospital, Miyazaki 885-0051, Japan.
| | - Yosai Mori
- Miyata eye hospital, Miyazaki 885-0051, Japan.
| | | | - Hideru Obinata
- Gunma University Initiative for Advanced Research (GIAR), Gunma 371-8511, Japan.
| | - Makoto Aihara
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| |
Collapse
|
16
|
Komatsu S, Wang L, Seow CY, Ikebe M. p116 Rip promotes myosin phosphatase activity in airway smooth muscle cells. J Cell Physiol 2019; 235:114-127. [PMID: 31347175 DOI: 10.1002/jcp.28949] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/28/2022]
Abstract
Myosin phosphatase-Rho interacting protein (p116Rip ) was originally found as a RhoA-binding protein. Subsequent studies by us and others revealed that p116Rip facilitates myosin light chain phosphatase (MLCP) activity through direct and indirect manners. However, it is unclear how p116Rip regulates myosin phosphatase activity in cells. To elucidate the role of p116Rip in cellular contractile processes, we suppressed the expression of p116Rip by RNA interference in human airway smooth muscle cells (HASMCs). We found that knockdown of p116Rip in HASMCs led to increased di-phosphorylated MLC (pMLC), that is phosphorylation at both Ser19 and Thr18. This was because of a change in the interaction between MLCP and myosin, but not an alteration of RhoA/ROCK signaling. Attenuation of Zipper-interacting protein kinase (ZIPK) abolished the increase in di-pMLC, suggesting that ZIPK is involved in this process. Moreover, suppression of p116Rip expression in HASMCs substantially increased the histamine-induced collagen gel contraction. We also found that expression of the p116Rip was decreased in the airway smooth muscle tissue from asthmatic patients compared with that from non-asthmatic patients, suggesting a potential role of p116Rip expression in asthma pathogenesis.
Collapse
Affiliation(s)
- Satoshi Komatsu
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas
| | - Lu Wang
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Chun Y Seow
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Mitsuo Ikebe
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas
| |
Collapse
|
17
|
Koga Y, Tsurumaki H, Aoki-Saito H, Sato M, Yatomi M, Takehara K, Hisada T. Roles of Cyclic AMP Response Element Binding Activation in the ERK1/2 and p38 MAPK Signalling Pathway in Central Nervous System, Cardiovascular System, Osteoclast Differentiation and Mucin and Cytokine Production. Int J Mol Sci 2019; 20:ijms20061346. [PMID: 30884895 PMCID: PMC6470985 DOI: 10.3390/ijms20061346] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/08/2019] [Accepted: 03/13/2019] [Indexed: 11/26/2022] Open
Abstract
There are many downstream targets of mitogen-activated protein kinase (MAPK) signalling that are involved in neuronal development, cellular differentiation, cell migration, cancer, cardiovascular dysfunction and inflammation via their functions in promoting apoptosis and cell motility and regulating various cytokines. It has been reported that cyclic AMP response element-binding protein (CREB) is phosphorylated and activated by cyclic AMP signalling and calcium/calmodulin kinase. Recent evidence also points to CREB phosphorylation by the MAPK signalling pathway. However, the specific roles of CREB phosphorylation in MAPK signalling have not yet been reviewed in detail. Here, we describe the recent advances in the study of this MAPK-CREB signalling axis in human diseases. Overall, the crosstalk between extracellular signal-related kinase (ERK) 1/2 and p38 MAPK signalling has been shown to regulate various physiological functions, including central nervous system, cardiac fibrosis, alcoholic cardiac fibrosis, osteoclast differentiation, mucin production in the airway, vascular smooth muscle cell migration, steroidogenesis and asthmatic inflammation. In this review, we focus on ERK1/2 and/or p38 MAPK-dependent CREB activation associated with various diseases to provide insights for basic and clinical researchers.
Collapse
Affiliation(s)
- Yasuhiko Koga
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Hiroaki Tsurumaki
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Haruka Aoki-Saito
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Makiko Sato
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Masakiyo Yatomi
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Kazutaka Takehara
- Department of Allergy and Respiratory Medicine, Gunma University Graduate School of Medicine, 3-39-15 sho-wa machi Maebashi, Gunma 371-8511, Japan.
| | - Takeshi Hisada
- Gunma University Graduate School of Health Sciences, 3-39-22 sho-wa machi Maebashi, Gunma 371-8514, Japan.
| |
Collapse
|
18
|
Eto M, Kitazawa T. Diversity and plasticity in signaling pathways that regulate smooth muscle responsiveness: Paradigms and paradoxes for the myosin phosphatase, the master regulator of smooth muscle contraction. J Smooth Muscle Res 2018; 53:1-19. [PMID: 28260704 PMCID: PMC5364378 DOI: 10.1540/jsmr.53.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
A hallmark of smooth muscle cells is their ability to adapt their functions to meet temporal and chronic fluctuations in their demands. These functions include force development and growth. Understanding the mechanisms underlying the functional plasticity of smooth muscles, the major constituent of organ walls, is fundamental to elucidating pathophysiological rationales of failures of organ functions. Also, the knowledge is expected to facilitate devising innovative strategies that more precisely monitor and normalize organ functions by targeting individual smooth muscles. Evidence has established a current paradigm that the myosin light chain phosphatase (MLCP) is a master regulator of smooth muscle responsiveness to stimuli. Cellular MLCP activity is negatively and positively regulated in response to G-protein activation and cAMP/cGMP production, respectively, through the MYPT1 regulatory subunit and an endogenous inhibitor protein named CPI-17. In this article we review the outcomes from two decade of research on the CPI-17 signaling and discuss emerging paradoxes in the view of signaling pathways regulating smooth muscle functions through MLCP.
Collapse
Affiliation(s)
- Masumi Eto
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University and Sidney Kimmel Cancer Center, 1020 Locust Street, Philadelphia, PA19107, USA
| | | |
Collapse
|
19
|
Nakamuta S, Yang YT, Wang CL, Gallo NB, Yu JR, Tai Y, Van Aelst L. Dual role for DOCK7 in tangential migration of interneuron precursors in the postnatal forebrain. J Cell Biol 2017; 216:4313-4330. [PMID: 29089377 PMCID: PMC5716287 DOI: 10.1083/jcb.201704157] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 09/01/2017] [Accepted: 09/15/2017] [Indexed: 12/14/2022] Open
Abstract
Throughout life, stem cells in the ventricular-subventricular zone generate neuroblasts that migrate via the rostral migratory stream (RMS) to the olfactory bulb, where they differentiate into local interneurons. Although progress has been made toward identifying extracellular factors that guide the migration of these cells, little is known about the intracellular mechanisms that govern the dynamic reshaping of the neuroblasts' morphology required for their migration along the RMS. In this study, we identify DOCK7, a member of the DOCK180-family, as a molecule essential for tangential neuroblast migration in the postnatal mouse forebrain. DOCK7 regulates the migration of these cells by controlling both leading process (LP) extension and somal translocation via distinct pathways. It controls LP stability/growth via a Rac-dependent pathway, likely by modulating microtubule networks while also regulating F-actin remodeling at the cell rear to promote somal translocation via a previously unrecognized myosin phosphatase-RhoA-interacting protein-dependent pathway. The coordinated action of both pathways is required to ensure efficient neuroblast migration along the RMS.
Collapse
Affiliation(s)
| | - Yu-Ting Yang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Chia-Lin Wang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Nicholas B Gallo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY.,Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY
| | - Jia-Ray Yu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Yilin Tai
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | | |
Collapse
|
20
|
Lin YH, Zhen YY, Chien KY, Lee IC, Lin WC, Chen MY, Pai LM. LIMCH1 regulates nonmuscle myosin-II activity and suppresses cell migration. Mol Biol Cell 2017; 28:1054-1065. [PMID: 28228547 PMCID: PMC5391182 DOI: 10.1091/mbc.e15-04-0218] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 02/13/2017] [Accepted: 02/17/2017] [Indexed: 11/18/2022] Open
Abstract
LIMCH1 specifically associates with contractile stress fibers. The N-terminus of LIMCH1 directly interacts with the head of NM-IIA. LIMCH1 depletion modulates the myosin regulatory light chain and FAK phosphorylation. Actin stress fiber and focal adhesion are decreased in LIMCH1-depleted cells, leading to increased cell migration. Nonmuscle myosin II (NM-II) is an important motor protein involved in cell migration. Incorporation of NM-II into actin stress fiber provides a traction force to promote actin retrograde flow and focal adhesion assembly. However, the components involved in regulation of NM-II activity are not well understood. Here we identified a novel actin stress fiber–associated protein, LIM and calponin-homology domains 1 (LIMCH1), which regulates NM-II activity. The recruitment of LIMCH1 into contractile stress fibers revealed its localization complementary to actinin-1. LIMCH1 interacted with NM-IIA, but not NM-IIB, independent of the inhibition of myosin ATPase activity with blebbistatin. Moreover, the N-terminus of LIMCH1 binds to the head region of NM-IIA. Depletion of LIMCH1 attenuated myosin regulatory light chain (MRLC) diphosphorylation in HeLa cells, which was restored by reexpression of small interfering RNA–resistant LIMCH1. In addition, LIMCH1-depleted HeLa cells exhibited a decrease in the number of actin stress fibers and focal adhesions, leading to enhanced cell migration. Collectively, our data suggest that LIMCH1 plays a positive role in regulation of NM-II activity through effects on MRLC during cell migration.
Collapse
Affiliation(s)
- Yu-Hung Lin
- Graduate Institute of Biomedical Sciences, Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan
| | - Yen-Yi Zhen
- Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan
| | - Kun-Yi Chien
- Graduate Institute of Biomedical Sciences, Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan.,Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan
| | - I-Ching Lee
- Graduate Institute of Biomedical Sciences, Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan
| | - Wei-Chi Lin
- Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei 11221, Taiwan
| | - Mei-Yu Chen
- Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei 11221, Taiwan.,Genome Research Center, National Yang Ming University, Taipei 11221, Taiwan
| | - Li-Mei Pai
- Graduate Institute of Biomedical Sciences, Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan .,Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan.,Liver Research Center, Chang Gung Memorial Hospital, Tao-Yuan 333, Taiwan
| |
Collapse
|
21
|
Chitano P, Wang L, Tin GYY, Ikebe M, Paré PD, Seow CY. Smooth muscle function and myosin polymerization. J Cell Sci 2017; 130:2468-2480. [DOI: 10.1242/jcs.202812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/01/2017] [Indexed: 01/28/2023] Open
Abstract
Smooth muscle is able to function over a much broader length range than striated muscle. The ability to maintain contractility after a large length change is thought to be due to an adaptive process involving restructuring of the contractile apparatus to maximize overlap between the contractile filaments. The molecular mechanism for the length-adaptive behavior is largely unknown. In smooth muscle adapted to different lengths we quantified myosin monomers, basal and activation-induced myosin light chain (MLC) phosphorylation, shortening-velocity, power-output and active force. The muscle was able to generate a constant maximal force over a 2-fold length range when it was allowed to go through isometric contraction/relaxation cycles after each length change (length adaptation). In the relaxed state myosin monomer concentration and basal MLC phosphorylation decreased linearly, while in the activated state activation-induced MLC phosphorylation and shortening-velocity/power-output increased linearly with muscle length. The results suggest that recruitment of myosin monomers and oligomers into the actin filament lattice (where they form force-generating filaments) occurs during muscle adaptation to longer length with the opposite occurring during adaptation to shorter length.
Collapse
Affiliation(s)
- Pasquale Chitano
- Centre for Heart Lung Innovation - St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Lu Wang
- Respiratory Division, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
- Centre for Heart Lung Innovation - St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Gabrielle Y. Y. Tin
- Centre for Heart Lung Innovation - St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Mitsuo Ikebe
- Department of Cellular and Molecular Biology, University of Texas Health Science Center, Tyler, Texas, USA
| | - Peter D. Paré
- Respiratory Division, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
- Centre for Heart Lung Innovation - St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Chun Y. Seow
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- Centre for Heart Lung Innovation - St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
22
|
Appiah-Kubi K, Lan T, Wang Y, Qian H, Wu M, Yao X, Wu Y, Chen Y. Platelet-derived growth factor receptors (PDGFRs) fusion genes involvement in hematological malignancies. Crit Rev Oncol Hematol 2016; 109:20-34. [PMID: 28010895 DOI: 10.1016/j.critrevonc.2016.11.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 10/21/2016] [Accepted: 11/15/2016] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To investigate oncogenic platelet-derived growth factor receptor(PDGFR) fusion genes involvement in hematological malignancies, the advances in the PDGFR fusion genes diagnosis and development of PDGFR fusions inhibitors. METHODS Literature search was done using terms "PDGFR and Fusion" or "PDGFR and Myeloid neoplasm" or 'PDGFR and Lymphoid neoplasm' or "PDGFR Fusion Diagnosis" or "PDGFR Fusion Targets" in databases including PubMed, ASCO.org, and Medscape. RESULTS Out of the 36 fusions detected, ETV6(TEL)-PDGFRB and FIP1L1-PDGFRA fusions were frequently detected, 33 are as a result of chromosomal translocation, FIP1L1-PDGFRA and EBF1-PDGFRB are the result of chromosomal deletion and CDK5RAP2- PDGFRΑ is the result of chromosomal insertion. Seven of the 34 rare fusions have detectable reciprocals. CONCLUSION RNA aptamers are promising therapeutic target of PDGFRs and diagnostic tools of PDGFRs fusion genes. Also, PDGFRs have variable prospective therapeutic strategies including small molecules, RNA aptamers, and interference therapeutics as well as development of adaptor protein Lnk mimetic drugs.
Collapse
Affiliation(s)
- Kwaku Appiah-Kubi
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China; Department of Applied Biology, University for Development Studies, Navrongo, Ghana.
| | - Ting Lan
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China
| | - Ying Wang
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China
| | - Hai Qian
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China
| | - Min Wu
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China
| | - Xiaoyuan Yao
- Basic medical department, Changchun medical college, Changchun, Jilin 130013, People's Republic of China
| | - Yan Wu
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China
| | - Yongchang Chen
- Department of Physiology, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, People's Republic of China.
| |
Collapse
|
23
|
Brozovich FV, Nicholson CJ, Degen CV, Gao YZ, Aggarwal M, Morgan KG. Mechanisms of Vascular Smooth Muscle Contraction and the Basis for Pharmacologic Treatment of Smooth Muscle Disorders. Pharmacol Rev 2016; 68:476-532. [PMID: 27037223 PMCID: PMC4819215 DOI: 10.1124/pr.115.010652] [Citation(s) in RCA: 298] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function.
Collapse
Affiliation(s)
- F V Brozovich
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| | - C J Nicholson
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| | - C V Degen
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| | - Yuan Z Gao
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| | - M Aggarwal
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| | - K G Morgan
- Department of Health Sciences, Boston University, Boston, Massachusetts (C.J.N., Y.Z.G., M.A., K.G.M.); Department of Medicine, Mayo Clinic, Rochester, Minnesota (F.V.B.); and Paracelsus Medical University Salzburg, Salzburg, Austria (C.V.D.)
| |
Collapse
|
24
|
Interaction of Myosin Phosphatase Target Subunit (MYPT1) with Myosin Phosphatase-RhoA Interacting Protein (MRIP): A Role of Glutamic Acids in the Interaction. PLoS One 2015; 10:e0139875. [PMID: 26445108 PMCID: PMC4596477 DOI: 10.1371/journal.pone.0139875] [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: 08/17/2015] [Accepted: 09/18/2015] [Indexed: 11/19/2022] Open
Abstract
Scaffold proteins bind to and functionally link protein members of signaling pathways. Interaction of the scaffold proteins, myosin phosphatase target subunit (MYPT1) and myosin phosphatase-RhoA interacting protein (MRIP), causes co-localization of myosin phosphatase and RhoA to actomyosin. To examine biophysical properties of interaction of MYPT1 with MRIP, we employed analytical ultracentrifugation and surface plasmon resonance. In regard to MRIP, its residues 724-837 are sufficient for the MYPT1/MRIP interaction. Moreover, MRIP binds to MYPT1 as either a monomer or a dimer. With respect to MYPT1, its leucine repeat region, LR (residues 991-1030) is sufficient to account for the MYPT1/MRIP interaction. Furthermore, point mutations that replace glutamic acids 998-1000 within LR reduced the binding affinity toward MRIP. This suggests that the glutamic acids of MYPT1 play an important role in the interaction.
Collapse
|
25
|
Ihara E, Yu Q, Chappellaz M, MacDonald JA. ERK and p38MAPK pathways regulate myosin light chain phosphatase and contribute to Ca2+ sensitization of intestinal smooth muscle contraction. Neurogastroenterol Motil 2015; 27:135-46. [PMID: 25557225 DOI: 10.1111/nmo.12491] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 11/20/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase (ERK) and p38MAPK, are known regulators of smooth muscle contractility. The contraction of smooth muscle is mainly regulated by the phosphorylation of regulatory light chains of myosin II (LC20), which is driven by the balance between myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP). We hypothesized that one possible mechanism for MAPK-dependent modulation of intestinal smooth muscle contractility is via the regulation of MLCP activity. METHODS Contractile responses to carbachol (CCh) and effects of MAPK inhibitors on CCh-induced contractions were assessed with isolated rat ileal longitudinal smooth muscle strips. Biochemical assessments of MLCP activity and myosin phosphatse targeting subunit (MYPT1) and CPI-17 phosphorylations were completed. KEY RESULTS Treatment of ileal smooth muscle with PD98059 (10 μM; MEK inhibitor) or SB203580 (10 μM; p38MAPK inhibitor) significantly inhibited CCh-induced contractile force. Decreased MLCP activity was observed during sustained contractions induced by CCh; the MLCP activity was recovered by treatment with PD98059 and SB203580. However, MYPT1 (Thr697 and Thr855) and CPI-17 (Thr38) phosphorylations were not affected. Application of ML-7 (MLCK inhibitor) during CCh-induced sustained contraction elicited an MLCP-dependent relaxation, the rate of which was accelerated by application of PD98059 and SB203580 with proportional changes in LC20 phosphorylation levels but not MYPT1 phosphorylation (Thr697 or Thr855). CONCLUSIONS & INFERENCES ERK and p38MAPK contribute to CCh-induced sustained contraction in a LC20 phosphorylation dependent manner. Moreover, both kinases inhibit MLCP activity possibly by a novel mechanism.
Collapse
Affiliation(s)
- E Ihara
- Smooth Muscle Research Group at the Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, Canada; Department of Medicine and Bioregulatory Science, Kyushu University, Higashi-ku, Fukuoka, Japan
| | | | | | | |
Collapse
|
26
|
Mahavadi S, Nalli A, Al-Shboul O, Murthy KS. Inhibition of MLC20 phosphorylation downstream of Ca2+ and RhoA: A novel mechanism involving phosphorylation of myosin phosphatase interacting protein (M-RIP) by PKG and stimulation of MLC phosphatase activity. Cell Biochem Biophys 2014; 68:1-8. [PMID: 23723008 DOI: 10.1007/s12013-013-9677-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Previous studies have shown that cGMP-dependent protein kinase (PKG) act on several targets in the contractile pathway to reduce intracellular Ca(2+) and/or augment RhoA-regulated myosin light chain phosphatase (MLCP) activity and cause muscle relaxation. Recent studies have identified a novel protein M-RIP that associates with MYPT1, the regulatory subunit of MLCP. Herein, we examine whether PKG enhance MLCP activity downstream of Ca(2+) and RhoA via phosphorylation of M-RIP in gastric smooth muscle cells. Treatment of permeabilized muscle cells with 10 μM Ca(2+) caused an increase in MLC20 phosphorylation and muscle contraction, but had no effect on Rho kinase activity. Activators of PKG (GSNO or cGMP) decreased MLC20 phosphorylation and contraction in response to 10 μM Ca(2+), implying existence of inhibitory mechanism independent of Ca(2+) and RhoA. The effect of PKG on Ca(2+)-induced MLC20 phosphorylation was attenuated by M-RIP siRNA. Both GSNO and 8-pCPT-cGMP induced phosphorylation of M-RIP; phosphorylation was accompanied by an increase in the association of M-RIP with MYPT1 and MLCP activity. Taken together, these results provide evidence that PKG induces phosphorylation of M-RIP and enhances its association with MYPT1 to augment MLCP activity and MLC20 dephosphorylation and inhibits muscle contraction, downstream of Ca(2+)- or RhoA-dependent pathways.
Collapse
Affiliation(s)
- Sunila Mahavadi
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, 23298-0711, USA
| | | | | | | |
Collapse
|
27
|
André G, Sandoval JE, Retailleau K, Loufrani L, Toumaniantz G, Offermanns S, Rolli-Derkinderen M, Loirand G, Sauzeau V. Smooth muscle specific Rac1 deficiency induces hypertension by preventing p116RIP3-dependent RhoA inhibition. J Am Heart Assoc 2014; 3:e000852. [PMID: 24938713 PMCID: PMC4309079 DOI: 10.1161/jaha.114.000852] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Background Increasing evidence implicates overactivation of RhoA as a critical component of the pathogenesis of hypertension. Although a substantial body of work has established that Rac1 functions antagonize RhoA in a broad range of physiological processes, the role of Rac1 in the regulation of vascular tone and blood pressure is not fully elucidated. Methods and Results To define the role of Rac1 in vivo in vascular smooth muscle cells (vSMC), we generated smooth muscle (SM)‐specific Rac1 knockout mice (SM‐Rac1‐KO) and performed radiotelemetric blood pressure recordings, contraction measurements in arterial rings, vSMC cultures and biochemical analyses. SM‐Rac1‐KO mice develop high systolic blood pressure sensitive to Rho kinase inhibition by fasudil. Arteries from SM‐Rac1‐KO mice are characterized by a defective NO‐dependent vasodilation and an overactivation of RhoA/Rho kinase signaling. We provide evidence that Rac1 deletion‐induced hypertension is due to an alteration of cGMP signaling resulting from the loss of Rac1‐mediated control of type 5 PDE activity. Consequently, cGMP‐dependent phosphorylation and binding of RhoA with its inhibitory partner, the phosphatase‐RhoA interacting protein (p116RIP3), are decreased. Conclusions Our data reveal that the depletion of Rac1 in SMC decreases cGMP‐dependent p116RIP3/RhoA interaction and the subsequent inhibition of RhoA signaling. Thus, we unveil an in vivo role of Rac1 in arterial blood pressure regulation and a new pathway involving p116RIP3 that contributes to the antagonistic relationship between Rac1 and RhoA in vascular smooth muscle cells and their opposite roles in arterial tone and blood pressure.
Collapse
Affiliation(s)
- Gwennan André
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.)
| | - Juan E Sandoval
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.)
| | - Kevin Retailleau
- Inserm UMR_S1083, CNRS UMR_C6214, BNMI, Angers, F-49000, France (K.R., L.L.)
| | - Laurent Loufrani
- Inserm UMR_S1083, CNRS UMR_C6214, BNMI, Angers, F-49000, France (K.R., L.L.)
| | - Gilles Toumaniantz
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.)
| | - Stefan Offermanns
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (S.O.)
| | - Malvyne Rolli-Derkinderen
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.)
| | - Gervaise Loirand
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) CHU Nantes, l'institut du thorax, Nantes, F-44000, France (G.L., V.S.)
| | - Vincent Sauzeau
- Inserm UMR_S1087, CNRS UMR_C6291, l'institut du thorax, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) Université de Nantes, Nantes, F-44000, France (G.A., J.E.S., G.T., M.R.D., G.L., V.S.) CHU Nantes, l'institut du thorax, Nantes, F-44000, France (G.L., V.S.)
| |
Collapse
|
28
|
Mahavadi S, Sriwai W, Huang J, Grider JR, Murthy KS. Inhibitory signaling by CB1 receptors in smooth muscle mediated by GRK5/β-arrestin activation of ERK1/2 and Src kinase. Am J Physiol Gastrointest Liver Physiol 2014; 306:G535-45. [PMID: 24407588 PMCID: PMC3949025 DOI: 10.1152/ajpgi.00397.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We examined whether CB1 receptors in smooth muscle conform to the signaling pattern observed with other Gi-coupled receptors that stimulate contraction via two Gβγ-dependent pathways (PLC-β3 and phosphatidylinositol 3-kinase/integrin-linked kinase). Here we show that the anticipated Gβγ-dependent signaling was abrogated. Except for inhibition of adenylyl cyclase via Gαi, signaling resulted from Gβγ-independent phosphorylation of CB1 receptors by GRK5, recruitment of β-arrestin1/2, and activation of ERK1/2 and Src kinase. Neither uncoupling of CB1 receptors from Gi by pertussis toxin (PTx) or Gi minigene nor expression of a Gβγ-scavenging peptide had any effect on ERK1/2 activity. The latter was abolished in muscle cells expressing β-arrestin1/2 siRNA. CB1 receptor internalization and both ERK1/2 and Src kinase activities were abolished in cells expressing kinase-deficient GRK5(K215R). Activation of ERK1/2 and Src kinase endowed CB1 receptors with the ability to inhibit concurrent contractile activity. We identified a consensus sequence (102KSPSKLSP109) for phosphorylation of RGS4 by ERK1/2 and showed that expression of a RGS4 mutant lacking Ser103/Ser108 blocked the ability of anandamide to inhibit acetylcholine-mediated phosphoinositide hydrolysis or enhance Gαq:RGS4 association and inactivation of Gαq. Activation of Src kinase by anandamide enhanced both myosin phosphatase RhoA-interacting protein (M-RIP):RhoA and M-RIP:MYPT1 association and inhibited Rho kinase activity, leading to increase of myosin light chain (MLC) phosphatase activity and inhibition of sustained muscle contraction. Thus, unlike other Gi-coupled receptors in smooth muscle, CB1 receptors did not engage Gβγ but signaled via GRK5/β-arrestin activation of ERK1/2 and Src kinase: ERK1/2 accelerated inactivation of Gαq by RGS4, and Src kinase enhanced MLC phosphatase activity, leading to inhibition of ACh-stimulated contraction.
Collapse
Affiliation(s)
- Sunila Mahavadi
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Wimolpak Sriwai
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Jiean Huang
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John R. Grider
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Karnam S. Murthy
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
29
|
Smith TC, Fridy PC, Li Y, Basil S, Arjun S, Friesen RM, Leszyk J, Chait BT, Rout MP, Luna EJ. Supervillin binding to myosin II and synergism with anillin are required for cytokinesis. Mol Biol Cell 2013; 24:3603-19. [PMID: 24088567 PMCID: PMC3842989 DOI: 10.1091/mbc.e12-10-0714] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cytokinesis, the process by which cytoplasm is apportioned between dividing daughter cells, requires coordination of myosin II function, membrane trafficking, and central spindle organization. Most known regulators act during late cytokinesis; a few, including the myosin II-binding proteins anillin and supervillin, act earlier. Anillin's role in scaffolding the membrane cortex with the central spindle is well established, but the mechanism of supervillin action is relatively uncharacterized. We show here that two regions within supervillin affect cell division: residues 831-1281, which bind central spindle proteins, and residues 1-170, which bind the myosin II heavy chain (MHC) and the long form of myosin light-chain kinase. MHC binding is required to rescue supervillin deficiency, and mutagenesis of this site creates a dominant-negative phenotype. Supervillin concentrates activated and total myosin II at the furrow, and simultaneous knockdown of supervillin and anillin additively increases cell division failure. Knockdown of either protein causes mislocalization of the other, and endogenous anillin increases upon supervillin knockdown. Proteomic identification of interaction partners recovered using a high-affinity green fluorescent protein nanobody suggests that supervillin and anillin regulate the myosin II and actin cortical cytoskeletons through separate pathways. We conclude that supervillin and anillin play complementary roles during vertebrate cytokinesis.
Collapse
Affiliation(s)
- Tara C Smith
- Program in Cell and Developmental Dynamics, Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655 Laboratory of Cellular and Structural Biology, Rockefeller University, New York, NY 10065 Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, New York, NY 10065 Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, MA 01545
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Butler T, Paul J, Europe-Finner N, Smith R, Chan EC. Role of serine-threonine phosphoprotein phosphatases in smooth muscle contractility. Am J Physiol Cell Physiol 2013; 304:C485-504. [PMID: 23325405 DOI: 10.1152/ajpcell.00161.2012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The degree of phosphorylation of myosin light chain 20 (MLC20) is a major determinant of force generation in smooth muscle. Myosin phosphatases (MPs) contain protein phosphatase (PP) 1 as catalytic subunits and are the major enzymes that dephosphorylate MLC20. MP regulatory targeting subunit 1 (MYPT1), the main regulatory subunit of MP in all smooth muscles, is a key convergence point of contractile and relaxatory pathways. Combinations of regulatory mechanisms, including isoform splicing, multiple phosphorylation sites, and scaffolding proteins, modulate MYPT1 activity with tissue and agonist specificities to affect contraction and relaxation. Other members of the PP1 family that do not target myosin, as well as PP2A and PP2B, dephosphorylate a range of proteins that affect smooth muscle contraction. This review discusses the role of phosphatases in smooth muscle contractility with a focus on MYPT1 in uterine smooth muscle. Myometrium shares characteristics of vascular and other visceral smooth muscles yet, during healthy pregnancy, undergoes hypertrophy, hyperplasia, quiescence, and labor as physiological processes. Myometrium presents an accessible model for the study of normal and pathological smooth muscle function, and a better understanding of myometrial physiology may allow the development of novel therapeutics for the many disorders of myometrial physiology from preterm labor to dysmenorrhea.
Collapse
Affiliation(s)
- Trent Butler
- Mothers and Babies Research Centre, Faculty of Health, University of Newcastle, Callaghan, NSW 2308, Australia
| | | | | | | | | |
Collapse
|
31
|
Tojkander S, Gateva G, Lappalainen P. Actin stress fibers--assembly, dynamics and biological roles. J Cell Sci 2012; 125:1855-64. [PMID: 22544950 DOI: 10.1242/jcs.098087] [Citation(s) in RCA: 515] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Actin filaments assemble into diverse protrusive and contractile structures to provide force for a number of vital cellular processes. Stress fibers are contractile actomyosin bundles found in many cultured non-muscle cells, where they have a central role in cell adhesion and morphogenesis. Focal-adhesion-anchored stress fibers also have an important role in mechanotransduction. In animal tissues, stress fibers are especially abundant in endothelial cells, myofibroblasts and epithelial cells. Importantly, recent live-cell imaging studies have provided new information regarding the mechanisms of stress fiber assembly and how their contractility is regulated in cells. In addition, these studies might elucidate the general mechanisms by which contractile actomyosin arrays, including muscle cell myofibrils and cytokinetic contractile ring, can be generated in cells. In this Commentary, we discuss recent findings concerning the physiological roles of stress fibers and the mechanism by which these structures are generated in cells.
Collapse
Affiliation(s)
- Sari Tojkander
- Institute of Biotechnology, University of Helsinki, Finland
| | | | | |
Collapse
|
32
|
Kim KM, Csortos C, Czikora I, Fulton D, Umapathy NS, Olah G, Verin AD. Molecular characterization of myosin phosphatase in endothelium. J Cell Physiol 2012; 227:1701-8. [PMID: 21678426 DOI: 10.1002/jcp.22894] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The phosphorylation status of myosin light chain (MLC) is regulated by both MLC kinases and type 1 Ser/Thr phosphatase (PPase 1), MLC phosphatase (MLCP) activities. The activity of the catalytic subunit of MLCP (CS1β) towards myosin depends on its associated regulatory subunit, namely myosin PPase targeting subunit 1 (MYPT1). Our previously published data strongly suggested the involvement of MLCP in endothelial cell (EC) barrier regulation. In this study, our new data demonstrate that inhibition of MLCP by either CS1β or MYPT1 siRNA-based depletion results in significant attenuation of purine nucleotide (ATP and adenosine)-induced EC barrier enhancement. Consistent with the data, thrombin-induced EC F-actin stress fiber formation and permeability increase were attenuated by the ectopic expression of constitutively active (C/A) MYPT1. The data demonstrated for the first time direct involvement of MLCP in EC barrier enhancement/protection. Cloning of MYPT1 in human pulmonary artery EC (HPAEC) revealed the presence of two MYPT1 isoforms, long and variant 2 (V2) lacking 56 amino acids from 553 to 609 of human MYPT1 long, which were previously identified in HeLa and HEK 293 cells. Our data demonstrated that in Cos-7 cells ectopically expressed EC MYPT1 isoforms co-immunoprecipitated with intact CS1β suggesting the importance of PPase 1 activity for the formation of functional complex of MYPT1/CS1β. Interestingly, MYPT1 V2 shows decreased binding affinity compared to MYPT1 long for radixin (novel MLCP substrate and a member of ERM family proteins). These results suggest functional difference between EC MYPT1 isoforms in the regulation of MLCP activity and cytoskeleton.
Collapse
Affiliation(s)
- Kyung-Mi Kim
- Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia 30912, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Sala-Valdés M, Gordón-Alonso M, Tejera E, Ibáñez A, Cabrero JR, Ursa A, Mittelbrunn M, Lozano F, Sánchez-Madrid F, Yáñez-Mó M. Association of syntenin-1 with M-RIP polarizes Rac-1 activation during chemotaxis and immune interactions. J Cell Sci 2012; 125:1235-46. [PMID: 22349701 DOI: 10.1242/jcs.094912] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
In this study, we describe that the PDZ protein syntenin-1 is a crucial element for the generation of signaling asymmetry during the cellular response to polarized extracellular cues. We analyze the role of syntenin-1 in the control of asymmetry in two independent models of T cell polarization--the migratory response to chemoattractants and the establishment of cognate interactions between T cells and antigen-presenting cells (APCs). A combination of mutant, biochemical and siRNA approaches demonstrate that syntenin-1 is vital for the generation of polarized actin structures such as the leading edge and the contact zone with APCs. We found that the mechanism by which syntenin-1 controls actin polymerization relies on its mandatory role for activation of the small GTPase Rac. Syntenin-1 controls Rac through a specific association with the myosin phosphatase Rho interacting protein (M-RIP), which occurs in response to phosphorylation of syntenin-1 by Src at Tyr4. Our data indicate the key role of syntenin-1 in the generation of functional asymmetry in T cells and provide a novel mechanistic link between receptor activation and actin polymerization and accumulation in response to extracellular stimulation.
Collapse
Affiliation(s)
- Mónica Sala-Valdés
- Departamento de Biología Vascular e Inflamación, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Lee JH, Palaia T, Ragolia L. Impaired insulin-stimulated myosin phosphatase Rho-interacting protein signaling in diabetic Goto-Kakizaki vascular smooth muscle cells. Am J Physiol Cell Physiol 2012; 302:C1371-81. [PMID: 22322972 DOI: 10.1152/ajpcell.00254.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin resistance associated with Type 2 diabetes contributes to impaired vasorelaxation and therefore contributes to the enhanced incidence of hypertension observed in diabetes. In this study, we examined the role of insulin on the association of the myosin-binding subunit of myosin phosphatase (MYPT1) to myosin phosphatase Rho-interacting protein (MRIP), a relatively novel member of the myosin phosphatase complex that directly binds RhoA in vascular smooth muscle cells (VSMCs). Through a series of molecular and cellular studies, we investigated whether insulin stimulates the binding of MRIP to MYPT1 and compared the results generated from VSMCs isolated from both Wistar-Kyoto (WKY) control and Goto-Kakizaki (GK) diabetic rats. We demonstrate for the first time that insulin stimulates the binding of MRIP to MYPT1 in a dose- and time-dependent manner, as determined by immunoprecipitation, implying a regulatory role for MRIP in insulin-induced vasodilation signaling via MYPT1 interaction. VSMCs from GK model of Type 2 diabetes had impaired insulin-induced MRIP/MYPT1 binding as well as reduced MRIP expression. Adenovirus-mediated overexpression of MRIP in GK VSMCs led to significantly improved insulin-stimulated MRIP/MYPT1 binding. Finally, insulin-stimulated MRIP translocation out of stress fibers, which was observed in control VSMCs, was impaired in GK VSMCs. We believe the impaired expression of MRIP, and therefore decreased insulin-stimulated MRIP/MYPT1 association, in the GK diabetic model may contribute to the impaired insulin-mediated vasodilation observed in the diabetic vasculature and provides a novel therapeutic strategy for the treatment of Type 2 diabetes.
Collapse
Affiliation(s)
- Jin Hee Lee
- Vascular Biology Institute, Winthrop-University Hospital, Mineola, New York 11501, USA
| | | | | |
Collapse
|
35
|
Vallenius T, Vaahtomeri K, Kovac B, Osiceanu AM, Viljanen M, Mäkelä TP. An association between NUAK2 and MRIP reveals a novel mechanism for regulation of actin stress fibers. J Cell Sci 2011; 124:384-93. [PMID: 21242312 DOI: 10.1242/jcs.072660] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Actin stress fiber assembly and contractility in nonmuscle motile cells requires phosphorylation of myosin regulatory light chain (MLC). Dephosphorylation and disassembly are mediated by MLC phosphatase, which is targeted to actin fibers by the association of its regulatory subunit MYPT1 with myosin phosphatase Rho-interacting protein (MRIP). In the present study, we identify the kinase NUAK2 as a second protein targeted by MRIP to actin fibers. Association of NUAK2 with MRIP increases MLC phosphorylation and promotes formation of stress fibers. This activity does not require the kinase activity of NUAK2 but is dependent on both MRIP and MYPT1, indicating that the NUAK2-MRIP association inhibits fiber disassembly and MYPT1-mediated MLC dephosphorylation. NUAK2 levels are strongly induced by stimuli increasing actomyosin fiber formation, and NUAK2 is required for fiber maintenance in exponentially growing cells, implicating NUAK2 in a positive-feedback loop regulating actin stress fibers independently of the MLC kinase Rho-associated protein kinase (ROCK). The identified MRIP-NUAK2 association reveals a novel mechanism for the maintenance of actin stress fibers through counteracting MYPT1 and, together with recent results, implicates the NUAK proteins as important regulators of the MLC phosphatase acting in both a kinase-dependent and kinase-independent manner.
Collapse
Affiliation(s)
- Tea Vallenius
- Institute of Biotechnology and Genome-Scale Biology Program, University of Helsinki, PO Box 56 Viikinkaari 9, 00014 University of Helsinki, Finland.
| | | | | | | | | | | |
Collapse
|
36
|
Schackmann RCJ, van Amersfoort M, Haarhuis JHI, Vlug EJ, Halim VA, Roodhart JML, Vermaat JS, Voest EE, van der Groep P, van Diest PJ, Jonkers J, Derksen PWB. Cytosolic p120-catenin regulates growth of metastatic lobular carcinoma through Rock1-mediated anoikis resistance. J Clin Invest 2011; 121:3176-88. [PMID: 21747168 DOI: 10.1172/jci41695] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 05/18/2011] [Indexed: 01/28/2023] Open
Abstract
Metastatic breast cancer is the major cause of cancer-related death among women in the Western world. Invasive carcinoma cells are able to counteract apoptotic signals in the absence of anchorage, enabling cell survival during invasion and dissemination. Although loss of E-cadherin is a cardinal event in the development and progression of invasive lobular carcinoma (ILC), little is known about the underlying mechanisms that govern these processes. Using a mouse model of human ILC, we show here that cytosolic p120-catenin (p120) regulates tumor growth upon loss of E-cadherin through the induction of anoikis resistance. p120 conferred anchorage independence by indirect activation of Rho/Rock signaling through interaction and inhibition of myosin phosphatase Rho-interacting protein (Mrip), an antagonist of Rho/Rock function. Consistent with these data, primary human ILC samples expressed hallmarks of active Rock signaling, and Rock controlled the anoikis resistance of human ILC cells. Thus, we have linked loss of E-cadherin - an initiating event in ILC development - to Rho/Rock-mediated control of anchorage-independent survival. Because activation of Rho and Rock are strongly linked to cancer progression and are susceptible to pharmacological inhibition, these insights may have clinical implications for the development of tailor-made intervention strategies to better treat invasive and metastatic lobular breast cancer.
Collapse
Affiliation(s)
- Ron C J Schackmann
- Department of Medical Oncology, University Medical Center Utrecht, Utrecht, the Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Kotlo KU, Hesabi B, Danziger RS. Implication of microRNAs in atrial natriuretic peptide and nitric oxide signaling in vascular smooth muscle cells. Am J Physiol Cell Physiol 2011; 301:C929-37. [PMID: 21734186 DOI: 10.1152/ajpcell.00088.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MicroRNAs (miRs) are endogenous small RNA molecules that suppress gene expression by binding to complementary sequences in the 3' untranslated regions of their target genes. miRs have been implicated in many diseases, including heart failure, ischemic heart disease, hypertension, cardiac hypertrophy, and cancers. Nitric oxide (NO) and atrial natriuretic peptide (ANP) are potent vasorelaxants whose actions are mediated through receptor guanylyl cyclases and cGMP-dependent protein kinase. The present study examines miRs in signaling by ANP and NO in vascular smooth muscle cells. miR microarray analysis was performed on human vascular smooth muscle cells (HVSMC) treated with ANP (10 nM, 4 h) and S-nitroso-N-acetylpenicillamine (SNAP) (100 μM, 4 h), a NO donor. Twenty-two shared miRs were upregulated, and 21 shared miRs were downregulated, by both ANP and SNAP (P < 0.05). Expression levels of four miRs (miRs-21, -26b, -98, and -1826), which had the greatest change in expression, as determined by microarray analysis, were confirmed by quantitative RT-PCR. Rp-8-Br-PET-cGMPS, a cGMP-dependent protein kinase-specific inhibitor, blocked the regulation of these miRs by ANP and SNAP. 8-bromo-cGMP mimicked the effect of ANP and SNAP on their expression. miR-21 was shown to inhibit HVSMC contraction in collagen gel lattice contraction assays. We also identified by computational algorithms and confirmed by Western blot analysis new intracellular targets of miR-21, i.e., cofilin-2 and myosin phosphatase and Rho interacting protein. Transfection with pre-miR-21 contracted cells and ANP and SNAP blocked miR-21-induced HVSMC contraction. Transfection with anti-miR-21 inhibitor reduced contractility of HVSMC (P < 0.05). The present results implicate miRs in NO and ANP signaling in general and miR-21 in particular in cGMP signaling and vascular smooth muscle cell relaxation.
Collapse
Affiliation(s)
- Kumar U Kotlo
- Department of Medicine, University of Illinois at Chicago, 60612, USA.
| | | | | |
Collapse
|
38
|
Grassie ME, Moffat LD, Walsh MP, MacDonald JA. The myosin phosphatase targeting protein (MYPT) family: a regulated mechanism for achieving substrate specificity of the catalytic subunit of protein phosphatase type 1δ. Arch Biochem Biophys 2011; 510:147-59. [PMID: 21291858 DOI: 10.1016/j.abb.2011.01.018] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 01/22/2011] [Accepted: 01/26/2011] [Indexed: 12/23/2022]
Abstract
The mammalian MYPT family consists of the products of five genes, denoted MYPT1, MYPT2, MBS85, MYPT3 and TIMAP, which function as targeting and regulatory subunits to confer substrate specificity and subcellular localization on the catalytic subunit of type 1δ protein serine/threonine phosphatase (PP1cδ). Family members share several conserved domains, including an RVxF motif for PP1c binding and several ankyrin repeats that mediate protein-protein interactions. MYPT1, MYPT2 and MBS85 contain C-terminal leucine zipper domains involved in dimerization and protein-protein interaction, whereas MYPT3 and TIMAP are targeted to membranes via a C-terminal prenylation site. All family members are regulated by phosphorylation at multiple sites by various protein kinases; for example, Rho-associated kinase phosphorylates MYPT1, MYPT2 and MBS85, resulting in inhibition of phosphatase activity and Ca(2+) sensitization of smooth muscle contraction. A great deal is known about MYPT1, the myosin targeting subunit of myosin light chain phosphatase, in terms of its role in the regulation of smooth muscle contraction and, to a lesser extent, non-muscle motile processes. MYPT2 appears to be the key myosin targeting subunit of myosin light chain phosphatase in cardiac and skeletal muscles. MBS85 most closely resembles MYPT2, but little is known about its physiological function. Little is also known about the physiological role of MYPT3, although it is likely to target myosin light chain phosphatase to membranes and thereby achieve specificity for substrates involved in regulation of the actin cytoskeleton. MYPT3 is regulated by phosphorylation by cAMP-dependent protein kinase. TIMAP appears to target PP1cδ to the plasma membrane of endothelial cells where it serves to dephosphorylate proteins involved in regulation of the actin cytoskeleton and thereby control endothelial barrier function. With such a wide range of regulatory targets, MYPT family members have been implicated in diverse pathological events, including hypertension, Parkinson's disease and cancer.
Collapse
Affiliation(s)
- Michael E Grassie
- Smooth Muscle Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | | | | | | |
Collapse
|
39
|
Nunes KP, Rigsby CS, Webb RC. RhoA/Rho-kinase and vascular diseases: what is the link? Cell Mol Life Sci 2010; 67:3823-36. [PMID: 20668910 PMCID: PMC2996825 DOI: 10.1007/s00018-010-0460-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 07/07/2010] [Accepted: 07/08/2010] [Indexed: 12/29/2022]
Abstract
RhoA/Rho-kinase pathway plays an important role in many pathological conditions. RhoA participates in the regulation of smooth muscle tone and activates many downstream kinases. The best characterized are the serine/threonine kinase isoforms (Rho-kinase or ROCK), ROCKα/ROCK2 and ROCKβ/ROCK1. ROCK is necessary for diverse functions such as local blood flow, arterial/pulmonary blood pressure, airway resistance and intestinal peristalsis. ROCK activation permits actin/myosin interactions and smooth muscle cells contraction by maintaining the activity of myosin light-chain kinase, independently of the free cytosolic calcium level. The sensitization of smooth muscle myofilaments to calcium has been implicated in many pathological states, such as hypertension, diabetes, heart attack, stroke, pulmonary hypertension, erectile dysfunction, and cancer. The focus of this review is on the involvement of RhoA/Rho-kinase in diseases. We will briefly describe the ROCK isoforms and the role of RhoA/Rho-kinase in the vasculature, before exploring the most recent findings regarding this pathway and various diseases.
Collapse
Affiliation(s)
- Kenia Pedrosa Nunes
- Department of Physiology, Medical College of Georgia, Augusta, GA 30912, USA.
| | | | | |
Collapse
|
40
|
Ressmeyer AR, Bai Y, Delmotte P, Uy KF, Thistlethwaite P, Fraire A, Sato O, Ikebe M, Sanderson MJ. Human airway contraction and formoterol-induced relaxation is determined by Ca2+ oscillations and Ca2+ sensitivity. Am J Respir Cell Mol Biol 2009; 43:179-91. [PMID: 19767449 DOI: 10.1165/rcmb.2009-0222oc] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The etiology of airway hyperresponsiveness associated with asthma requires an understanding of the regulatory mechanisms mediating human airway smooth muscle cell (SMC) contraction. The objective of this study was to determine how human airway SMC contraction (induced by histamine) and relaxation (induced by formoterol) are regulated by Ca(2+) oscillations and Ca(2+) sensitivity. The responses of human small airways and their associated SMCs were studied in human lung slices cut from agarose-inflated lungs. Airway contraction was measured with phase-contrast video microscopy. Ca(2+) signaling and Ca(2+) sensitivity of airway SMCs were measured with two-photon fluorescence microscopy and Ca(2+)-permeabilized lung slices. The agonist histamine induced contraction of human small airways by stimulating both an increase in intracellular Ca(2+) concentration in the SMCs in the form of oscillatory Ca(2+) waves and an increase in Ca(2+) sensitivity. The frequency of the Ca(2+) oscillations increased with histamine concentration, and correlated with increased contraction. Formoterol induced airway relaxation at low concentrations by initially decreasing SMC Ca(2+) sensitivity. At higher concentrations, formoterol additionally slowed or inhibited the Ca(2+) oscillations of the SMCs to relax the airways. The action of formoterol was only slowly reversed. Human lung slices provide a powerful experimental assay for the investigation of small airway physiology and pharmacology. Histamine induces contraction by simultaneously increasing SMC Ca(2+) signaling and Ca(2+) sensitivity. Formoterol induces long-lasting relaxation by initially reducing the Ca(2+) sensitivity and, subsequently, the frequency of the Ca(2+) oscillations of the airway SMCs.
Collapse
Affiliation(s)
- Anna-Rebekka Ressmeyer
- Department of Physiology, University of Massachusetts Medical School, Worcester, 01655, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Kim HR, Appel S, Vetterkind S, Gangopadhyay SS, Morgan KG. Smooth muscle signalling pathways in health and disease. J Cell Mol Med 2009. [PMID: 19120701 DOI: 10.1111/j.1582-4934.2008.00552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Smooth muscle contractile activity is a major regulator of function of the vascular system, respiratory system, gastrointestinal system and the genitourinary systems. Malfunction of contractility in these systems leads to a host of clinical disorders, and yet, we still have major gaps in our understanding of the molecular mechanisms by which contractility of the differentiated smooth muscle cell is regulated. This review will summarize recent advances in the molecular understanding of the regulation of smooth muscle myosin activity via phosphorylation/dephosphorylation of myosin, the regulation of the accessibility of actin to myosin via the actin-binding proteins calponin and caldesmon, and the remodelling of the actin cytoskeleton. Understanding of the molecular 'players' should identify target molecules that could point the way to novel drug discovery programs for the treatment of smooth muscle disorders such as cardiovascular disease, asthma, functional bowel disease and pre-term labour.
Collapse
Affiliation(s)
- H R Kim
- Department of Health Sciences, Boston University, Boston, MA 02215, USA
| | | | | | | | | |
Collapse
|
42
|
Wang Y, Zheng XR, Riddick N, Bryden M, Baur W, Zhang X, Surks HK. ROCK isoform regulation of myosin phosphatase and contractility in vascular smooth muscle cells. Circ Res 2009; 104:531-40. [PMID: 19131646 DOI: 10.1161/circresaha.108.188524] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abnormal vascular smooth muscle cell (VSMC) contraction plays an important role in vascular diseases. The RhoA/ROCK signaling pathway is now well recognized to mediate vascular smooth muscle contraction in response to vasoconstrictors by inhibiting myosin phosphatase (MLCP) activity and increasing myosin light chain phosphorylation. Two ROCK isoforms, ROCK1 and ROCK2, are expressed in many tissues, yet the isoform-specific roles of ROCK1 and ROCK2 in vascular smooth muscle and the mechanism of ROCK-mediated regulation of MLCP are not well understood. In this study, ROCK2, but not ROCK1, bound directly to the myosin binding subunit of MLCP, yet both ROCK isoforms regulated MLCP and myosin light chain phosphorylation. Despite that both ROCK1 and ROCK2 regulated MLCP, the ROCK isoforms had distinct and opposing effects on VSMC morphology and ROCK2, but not ROCK1, had a predominant role in VSMC contractility. These data support that although the ROCK isoforms both regulate MLCP and myosin light chain phosphorylation through different mechanisms, they have distinct roles in VSMC function.
Collapse
Affiliation(s)
- Yuepeng Wang
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Neppl RL, Lubomirov LT, Momotani K, Pfitzer G, Eto M, Somlyo AV. Thromboxane A2-induced bi-directional regulation of cerebral arterial tone. J Biol Chem 2008; 284:6348-60. [PMID: 19095646 DOI: 10.1074/jbc.m807040200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myosin light chain phosphatase plays a critical role in modulating smooth muscle contraction in response to a variety of physiologic stimuli. A downstream target of the RhoA/Rho-kinase and nitric oxide (NO)/cGMP/cyclic GMP-dependent kinase (cGKI) pathways, myosin light chain phosphatase activity reflects the sum of both calcium sensitization and desensitization pathways through phosphorylation and dephosphorylation of the myosin phosphatase targeting subunit (MYPT1). As cerebral blood flow is highly spatio-temporally modulated under normal physiologic conditions, severe perturbations in normal cerebral blood flow, such as in cerebral vasospasm, can induce neurological deficits. In nonpermeabilized cerebral vessels stimulated with U-46619, a stable mimetic of endogenous thromboxane A2 implicated in the etiology of cerebral vasospasm, we observed significant increases in contractile force, RhoA activation, regulatory light chain phosphorylation, as well as phosphorylation of MYPT1 at Thr-696, Thr-853, and surprisingly Ser-695. Inhibition of nitric oxide signaling completely abrogated basal MYPT1 Ser-695 phosphorylation and significantly increased and potentiated U-46619-induced MYPT1 Thr-853 phosphorylation and contractile force, indicating that NO/cGMP/cGKI signaling maintains basal vascular tone through active inhibition of calcium sensitization. Surprisingly, a fall in Ser-695 phosphorylation did not result in an increase in phosphorylation of the Thr-696 site. Although activation of cGKI with exogenous cyclic nucleotides inhibited thromboxane A2-induced MYPT1 membrane association, RhoA activation, contractile force, and regulatory light chain phosphorylation, the anticipated decreases in MYPT1 phosphorylation at Thr-696/Thr-853 were not observed, indicating that the vasorelaxant effects of cGKI are not through dephosphorylation of MYPT1. Thus, thromboxane A2 signaling within the intact cerebral vasculature induces "buffered" vasoconstrictions, in which both the RhoA/Rho-kinase calcium-sensitizing and the NO/cGMP/cGKI calcium-desensitizing pathways are activated.
Collapse
Affiliation(s)
- Ronald L Neppl
- Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia 22908, USA
| | | | | | | | | | | |
Collapse
|
44
|
Kim HR, Appel S, Vetterkind S, Gangopadhyay SS, Morgan KG. Smooth muscle signalling pathways in health and disease. J Cell Mol Med 2008; 12:2165-80. [PMID: 19120701 PMCID: PMC2692531 DOI: 10.1111/j.1582-4934.2008.00552.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 10/08/2008] [Indexed: 12/24/2022] Open
Abstract
Smooth muscle contractile activity is a major regulator of function of the vascular system, respiratory system, gastrointestinal system and the genitourinary systems. Malfunction of contractility in these systems leads to a host of clinical disorders, and yet, we still have major gaps in our understanding of the molecular mechanisms by which contractility of the differentiated smooth muscle cell is regulated. This review will summarize recent advances in the molecular understanding of the regulation of smooth muscle myosin activity via phosphorylation/dephosphorylation of myosin, the regulation of the accessibility of actin to myosin via the actin-binding proteins calponin and caldesmon, and the remodelling of the actin cytoskeleton. Understanding of the molecular 'players' should identify target molecules that could point the way to novel drug discovery programs for the treatment of smooth muscle disorders such as cardiovascular disease, asthma, functional bowel disease and pre-term labour.
Collapse
Affiliation(s)
- H R Kim
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | - S Appel
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | - S Vetterkind
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | | | - K G Morgan
- Department of Health Sciences, Boston UniversityBoston, MA, USA
- Boston Biomedical Research InstituteWatertown, MA, USA
| |
Collapse
|
45
|
Ohnuma S, Miura K, Horii A, Fujibuchi W, Kaneko N, Gotoh O, Nagasaki H, Mizoi T, Tsukamoto N, Kobayashi T, Kinouchi M, Okabe M, Sasaki H, Shiiba KI, Miyagawa K, Sasaki I. Cancer-associated splicing variants of the CDCA1 and MSMB genes expressed in cancer cell lines and surgically resected gastric cancer tissues. Surgery 2008; 145:57-68. [PMID: 19081476 DOI: 10.1016/j.surg.2008.08.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 08/01/2008] [Indexed: 12/18/2022]
Abstract
BACKGROUND Alternative splicing is a molecular mechanism by which different combinations of exons can be alternatively spliced to produce different mRNA isoforms. Recently, several databases have been published to predict the alternative splicing of mRNA; cancer-specific alternative splicing has also been predicted with these databases. Those variants may be potentially useful targets for cancer therapy, however, the accuracy and veracity of these databases have yet to be confirmed. METHODS In this study, we analyzed 17 genes by reverse transcriptase-polymerase chain reaction (RT-PCR) that were predicted to have cancer-specific alternative splicing by using the splicing database, the Alternative Splicing Annotation Project (ASAP) by Lee et al, between 38 cancer cell lines from various organs and 9 corresponding normal tissues. By designing 2 types of primer sets for RT-PCR including (1) primers flanking the alternatively spliced exons and (2) primers spanning the exon/exon junctions, cancer-associated splicing variants were investigated. RESULTS The alternatively splicing events were detected in 15 of 17 genes (88%); 35 of 43 variants (81%) were detected successfully with RT-PCR. Among these variants, M-RIP, HYAL2, CDCA1, and MSMB genes showed differential expressions between cancer cell lines and corresponding normal tissues. Furthermore, RT-PCR with surgically resected gastric cancer tissues (diffuse type, 6; intestinal type, 4) confirmed that 2 variants of CDCA1 were upregulated in cancer tissues, whereas both variants of MSMB were expressed predominantly in normal tissues. CONCLUSION Alternative splicing variants, especially in CDCA1, were detected in this study and may be potentially useful as diagnostic markers and/or novel targets for anticancer therapy.
Collapse
Affiliation(s)
- Shinobu Ohnuma
- Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Riddick N, Ohtani KI, Surks HK. Targeting by myosin phosphatase-RhoA interacting protein mediates RhoA/ROCK regulation of myosin phosphatase. J Cell Biochem 2008; 103:1158-70. [PMID: 17661354 DOI: 10.1002/jcb.21488] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Vascular smooth muscle cell contractile state is the primary determinant of blood vessel tone. Vascular smooth muscle cell contractility is directly related to the phosphorylation of myosin light chains (MLCs), which in turn is tightly regulated by the opposing activities of myosin light chain kinase (MLCK) and myosin phosphatase. Myosin phosphatase is the principal enzyme that dephosphorylates MLCs leading to relaxation. Myosin phosphatase is regulated by both vasoconstrictors that inhibit its activity to cause MLC phosphorylation and contraction, and vasodilators that activate its activity to cause MLC dephosphorylation and relaxation. The RhoA/ROCK pathway is activated by vasoconstrictors to inhibit myosin phosphatase activity. The mechanism by which RhoA and ROCK are localized to and interact with myosin light chain phosphatase (MLCP) is not well understood. We recently found a new member of the myosin phosphatase complex, myosin phosphatase-rho interacting protein, that directly binds to both RhoA and the myosin-binding subunit of myosin phosphatase in vitro, and targets myosin phosphatase to the actinomyosin contractile filament in smooth muscle cells. Because myosin phosphatase-rho interacting protein binds both RhoA and MLCP, we investigated whether myosin phosphatase-rho interacting protein was required for RhoA/ROCK-mediated myosin phosphatase regulation. Myosin phosphatase-rho interacting protein silencing prevented LPA-mediated myosin-binding subunit phosphorylation, and inhibition of myosin phosphatase activity. Myosin phosphatase-rho interacting protein did not regulate the activation of RhoA or ROCK in vascular smooth muscle cells. Silencing of M-RIP lead to loss of stress fiber-associated RhoA, suggesting that myosin phosphatase-rho interacting protein is a scaffold linking RhoA to regulate myosin phosphatase at the stress fiber.
Collapse
Affiliation(s)
- Nadeene Riddick
- Molecular Cardiology Research Institute and the Division of Cardiology, Tufts-New England Medical Center, Box 80, 750 Washington St., Boston, Massachusetts 02111, USA
| | | | | |
Collapse
|
47
|
Vetterkind S, Morgan KG. The pro-apoptotic protein Par-4 facilitates vascular contractility by cytoskeletal targeting of ZIPK. J Cell Mol Med 2008; 13:887-95. [PMID: 18505470 PMCID: PMC2700217 DOI: 10.1111/j.1582-4934.2008.00374.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Par-4 (prostate apoptosis response 4) is a pro-apoptotic protein and tumour suppressor that was originally identified as a gene product up-regulated during apoptosis in prostate cancer cells. Here, we show, for the first time, that Par-4 is expressed and co-localizes with the actin filament bundles in vascular smooth muscle. Furthermore, we demonstrate that targeting of ZIPK to the actin filaments, as observed upon PGF-2α stimulation, is inhibited by the presence of a cell permeant Par-4 decoy peptide. The same decoy peptide also significantly inhibits PGF-2α induced contractions of smooth muscle tissue. Moreover, knockdown of Par-4 using antisense morpholino nucleotides results in significantly reduced contractility, and myosin light chain and myosin phosphatase target subunit phosphorylation. These results indicate that Par-4 facilitates contraction by targeting ZIPK to the vicinity of its substrates, myosin light chain and MYPT, which are located on the actin filaments. These results identify Par-4 as a novel regulator of myosin light chain phosphorylation in differentiated, contractile vascular smooth muscle.
Collapse
|
48
|
Morin C, Guibert C, Sirois M, Echave V, Gomes MM, Rousseau E. Effects of omega-hydroxylase product on distal human pulmonary arteries. Am J Physiol Heart Circ Physiol 2008; 294:H1435-43. [PMID: 18203846 DOI: 10.1152/ajpheart.01115.2007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of the present study was to provide a mechanistic insight into how 20-hydroxyeicosatetraenoic acid (20-HETE) relaxes distal human pulmonary arteries (HPAs). This compound is produced by omega-hydroxylase from free arachidonic acid. Tension measurements, performed on either fresh or 1 day-cultured pulmonary arteries, revealed that the contractile responses to 1 microM 5-hydroxytryptamine were largely relaxed by 20-HETE in a concentration-dependent manner (0.01-10 microM). Iberiotoxin pretreatments (10 nM) partially decreased 20-HETE-induced relaxations. However, 10 microM indomethacin and 3 microM SC-560 pretreatments significantly reduced the relaxations to 20-HETE in these tissues. The relaxing responses induced by the eicosanoid were likely related to a reduced Ca2+ sensitivity of the myofilaments since free Ca2+ concentration ([Ca2+])-response curves performed on beta-escin-permeabilized cultured explants were shifted toward higher [Ca2+]. 20-HETE also abolished the tonic responses induced by phorbol-ester-dibutyrate (a PKC-sensitizing agent). Western blot analyses, using two specific primary antibodies against the PKC-potentiated inhibitory protein CPI-17 and its PKC-dependent phosphorylated isoform pCPI-17, confirmed that 20-HETE interferes with this intracellular process. We also investigated the effect of 20-HETE on the activation of Rho-kinase pathway-induced Ca2+ sensitivity. The data demonstrated that 20-HETE decreased U-46619-induced Ca2+ sensitivity on arteries. Hence, this observation was correlated with an increased staining of p116(Rip), a RhoA-binding protein. Together, these results strongly suggest that the 20-hydroxyarachidonic acid derivative is a potent modulator of tone in HPAs in vitro.
Collapse
Affiliation(s)
- Caroline Morin
- Le Bilarium, Department of Physiology and Biophysics, Université de Sherbrooke, 3001 12th Ave. N, Sherbrooke, J1H 5N4, QC, Canada
| | | | | | | | | | | |
Collapse
|
49
|
Matsumura F, Hartshorne DJ. Myosin phosphatase target subunit: Many roles in cell function. Biochem Biophys Res Commun 2007; 369:149-56. [PMID: 18155661 DOI: 10.1016/j.bbrc.2007.12.090] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Accepted: 12/11/2007] [Indexed: 12/12/2022]
Abstract
Phosphorylation of myosin II is important in many aspects of cell function and involves a myosin kinase, e.g. myosin light chain kinase, and a myosin phosphatase (MP). MP is regulated by the myosin phosphatase target subunit (MYPT1). The domain structure, properties, and genetic analyses of MYPT1 and its isoforms are outlined. MYPT1 binds the catalytic subunit of type 1 phosphatase, delta isoform, and also acts as an interactive platform for many other proteins. A key reaction for MP is with phosphorylated myosin II and the first process shown to be regulated by MP was contractile activity of smooth muscle. In cell division and cell migration myosin II phosphorylation also plays a critical role and these are discussed. However, based on the wide range of partners for MYPT1 it is likely that MP is implicated with substrates other than myosin II. Open questions are whether the diverse functions of MP reflect different cellular locations and/or specific roles for the MYPT1 isoforms.
Collapse
Affiliation(s)
- Fumio Matsumura
- Department of Molecular Biology and Biochemistry, Rutgers University, 604, Allison Road, Piscataway, NJ 08855, USA
| | | |
Collapse
|
50
|
Koga Y, Ikebe M. A novel regulatory mechanism of myosin light chain phosphorylation via binding of 14-3-3 to myosin phosphatase. Mol Biol Cell 2007; 19:1062-71. [PMID: 18094049 DOI: 10.1091/mbc.e07-07-0668] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Myosin II phosphorylation-dependent cell motile events are regulated by myosin light-chain (MLC) kinase and MLC phosphatase (MLCP). Recent studies have revealed myosin phosphatase targeting subunit (MYPT1), a myosin-binding subunit of MLCP, plays a critical role in MLCP regulation. Here we report the new regulatory mechanism of MLCP via the interaction between 14-3-3 and MYPT1. The binding of 14-3-3beta to MYPT1 diminished the direct binding between MYPT1 and myosin II, and 14-3-3beta overexpression abolished MYPT1 localization at stress fiber. Furthermore, 14-3-3beta inhibited MLCP holoenzyme activity via the interaction with MYPT1. Consistently, 14-3-3beta overexpression increased myosin II phosphorylation in cells. We found that MYPT1 phosphorylation at Ser472 was critical for the binding to 14-3-3. Epidermal growth factor (EGF) stimulation increased both Ser472 phosphorylation and the binding of MYPT1-14-3-3. Rho-kinase inhibitor inhibited the EGF-induced Ser472 phosphorylation and the binding of MYPT1-14-3-3. Rho-kinase specific siRNA also decreased EGF-induced Ser472 phosphorylation correlated with the decrease in MLC phosphorylation. The present study revealed a new RhoA/Rho-kinase-dependent regulatory mechanism of myosin II phosphorylation by 14-3-3 that dissociates MLCP from myosin II and attenuates MLCP activity.
Collapse
Affiliation(s)
- Yasuhiko Koga
- Department of Physiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | |
Collapse
|