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Song SE, Shin SK, Kim YW, Do YR, Lim AK, Bae JH, Jeong GS, Im SS, Song DK. Lupenone attenuates thapsigargin-induced endoplasmic reticulum stress and apoptosis in pancreatic beta cells possibly through inhibition of protein tyrosine kinase 2 activity. Life Sci 2023; 332:122107. [PMID: 37739164 DOI: 10.1016/j.lfs.2023.122107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/14/2023] [Accepted: 09/17/2023] [Indexed: 09/24/2023]
Abstract
AIMS Prolonged high levels of cytokines, glucose, or free fatty acids are associated with diabetes, elevation of cytosolic Ca2+ concentration ([Ca2+]C), and depletion of Ca2+ concentration in the endoplasmic reticulum (ER) of pancreatic beta cells. This Ca2+ imbalance induces ER stress and apoptosis. Lupenone, a lupan-type triterpenoid, is beneficial in diabetes; however, its mechanism of action is yet to be clarified. This study evaluated the protective mechanism of lupenone against thapsigargin-induced ER stress and apoptosis in pancreatic beta cells. MATERIALS AND METHODS MIN6, INS-1, and native mouse islet cells were used. Western blot for protein expressions, measurement of [Ca2+]C, and in vivo glucose tolerance test were mainly performed. KEY FINDINGS Thapsigargin increased the protein levels of cleaved caspase 3, cleaved PARP, and the phosphorylated form of JNK, ATF4, and CHOP. Thapsigargin increased the interaction between stromal interaction molecule1 (Stim1) and Orai1, enhancing store-operated calcium entry (SOCE). SOCE is further activated by protein tyrosine kinase 2 (Pyk2), which is Ca2+-dependent and phosphorylates the tyrosine residue at Y361 in Stim1. Lupenone inhibited thapsigargin-mediated Pyk2 activation, suppressed [Ca2+]C, ER stress, and apoptosis. Lupenone restored impaired glucose-stimulated insulin secretion effectuated by thapsigargin and glucose intolerance in a low-dose streptozotocin-induced diabetic mouse model. SIGNIFICANCE These results suggested that lupenone attenuated thapsigargin-induced ER stress and apoptosis by inhibiting SOCE; this may be due to the hindrance of Pyk2-mediated Stim1 tyrosine phosphorylation. In beta cells that are inevitably exposed to frequent [Ca2+]C elevation, the attenuation of abnormally high SOCE would be beneficial for their survival.
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Affiliation(s)
- Seung-Eun Song
- Department of Physiology & Obesity-mediated Disease Research Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Su-Kyung Shin
- Department of Food Science and Nutrition, Kyungpook National University, Daegu, South Korea
| | - Yong-Woon Kim
- Department of Physiology, Yeungnam University School of Medicine, Daegu, South Korea
| | - Young Rok Do
- Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, South Korea
| | - Ae Kyoung Lim
- Department of Physiology & Obesity-mediated Disease Research Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Jae-Hoon Bae
- Department of Physiology & Obesity-mediated Disease Research Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Gil-Saeng Jeong
- Keimyung University, College of Pharmacy, Daegu, South Korea
| | - Seung-Soon Im
- Department of Physiology & Obesity-mediated Disease Research Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Dae-Kyu Song
- Department of Physiology & Obesity-mediated Disease Research Center, Keimyung University School of Medicine, Daegu, South Korea.
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Feng D, Guo YY, Wang W, Yan LF, Sun T, Liu QQ, Cui GB, Nan HY. α-Subunit Tyrosine Phosphorylation Is Required for Activation of the Large Conductance Ca 2+-Activated Potassium Channel in the Rabbit Sphincter of Oddi. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1725-1744. [PMID: 36150507 DOI: 10.1016/j.ajpath.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/06/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Large conductance Ca2+-activated potassium (BKCa) channels are regulated by intracellular free Ca2+ concentrations ([Ca2+]i) and channel protein phosphorylation. In hypercholesterolemia (HC), motility impairment of the sphincter of Oddi (SO) is associated with abnormal [Ca2+]i accumulation in smooth muscle cells of the rabbit SO (RSOSMCs), which is closely related to BKCa channel activity. However, the underlying mechanisms regulating channel activity remain unclear. In this study, an HC rabbit model was generated and used to investigate BKCa channel activity of RSOSMCs via SO muscle tone measurement in vitro and manometry in vivo, electrophysiological recording, intracellular calcium measurement, and Western blot analyses. BKCa channel activity was decreased, which correlated with [Ca2+]i overload and reduced tyrosine phosphorylation of the BKCa α-subunit in the HC group. The abnormal [Ca2+]i accumulation and decreased BKCa channel activity were partially restored by Na3VO4 pretreatment but worsened by genistein in RSOSMCs in the HC group. This study suggests that α-subunit tyrosine phosphorylation is required for [Ca2+]i to activate BKCa channels, and there is a negative feedback between the BKCa channel and the L-type voltage-dependent Ca2+ channel that regulates [Ca2+]i. This study provides direct evidence that tyrosine phosphorylation of BKCa α-subunits is required for [Ca2+]i to activate BKCa channels in RSOSMCs, which may be the underlying physiological and pathologic mechanism regulating the activity of BKCa channels in SO cells.
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Affiliation(s)
- Dan Feng
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Yan-Yan Guo
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Wen Wang
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Lin-Feng Yan
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Ting Sun
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Qing-Qing Liu
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Guang-Bin Cui
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
| | - Hai-Yan Nan
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
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Nicholson CJ, Xing Y, Lee S, Liang S, Mohan S, O'Rourke C, Kang J, Morgan KG. Ageing causes an aortic contractile dysfunction phenotype by targeting the expression of members of the extracellular signal-regulated kinase pathway. J Cell Mol Med 2022; 26:1456-1465. [PMID: 35181997 PMCID: PMC8899171 DOI: 10.1111/jcmm.17118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 11/30/2022] Open
Abstract
The extracellular signal-regulated kinase (ERK) pathway is a well-known regulator of vascular smooth muscle cell proliferation, but it also serves as a regulator of caldesmon, which negatively regulates vascular contractility. This study examined whether aortic contractile function requires ERK activation and if this activation is regulated by ageing. Biomechanical experiments revealed that contractile responses to the alpha1-adrenergic agonist phenylephrine are attenuated specifically in aged mice, which is associated with downregulation of ERK phosphorylation. ERK inhibition attenuates phenylephrine-induced contractility, indicating that the contractile tone is at least partially ERK-dependent. To explore the mechanisms of this age-related downregulation of ERK phosphorylation, we transfected microRNAs, miR-34a and miR-137 we have previously shown to increase with ageing and demonstrated that in A7r5 cells, both miRs downregulate the expression of Src and paxillin, known regulators of ERK signalling, as well as ERK phosphorylation. Further studies in aortic tissues transfected with miRs show that miR-34a but not miR-137 has a negative effect on mRNA levels of Src and paxillin. Furthermore, ERK phosphorylation is decreased in aortic tissue treated with the Src inhibitor PP2. Increases in miR-34a and miR-137 with ageing downregulate the expression of Src and paxillin, leading to impaired ERK signalling and aortic contractile dysfunction.
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Affiliation(s)
- Christopher J Nicholson
- Department of Health Sciences, Boston University, Boston, MA, USA.,Department of Medicine, Cardiology Division, Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Yi Xing
- Department of Health Sciences, Boston University, Boston, MA, USA
| | - Sophie Lee
- Department of Health Sciences, Boston University, Boston, MA, USA
| | - Stephanie Liang
- Department of Health Sciences, Boston University, Boston, MA, USA
| | - Shivani Mohan
- Department of Health Sciences, Boston University, Boston, MA, USA
| | - Caitlin O'Rourke
- Department of Health Sciences, Boston University, Boston, MA, USA
| | - Joshua Kang
- Department of Health Sciences, Boston University, Boston, MA, USA
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4
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Moraes RDA, Alves QL, Camargo SB, Medeiros CFDA, Jesus ADM, da Hora VRS, Stiz DS, Corrêa R, Cechinel-Filho V, Silva DF. Itaconimides derivatives induce relaxation in mesenteric artery and negative inotropism by inhibition of CA2+ influx. Pharmacol Rep 2020; 72:890-902. [DOI: 10.1007/s43440-019-00051-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/24/2019] [Accepted: 12/11/2019] [Indexed: 11/29/2022]
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5
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Oono K, Ohtake K, Watanabe C, Shiba S, Sekiya T, Kasono K. Contribution of Pyk2 pathway and reactive oxygen species (ROS) to the anti-cancer effects of eicosapentaenoic acid (EPA) in PC3 prostate cancer cells. Lipids Health Dis 2020; 19:15. [PMID: 32005121 PMCID: PMC6993438 DOI: 10.1186/s12944-019-1122-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/30/2019] [Indexed: 01/04/2023] Open
Abstract
Background n-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are thought to exert protective effects in cardiovascular diseases. In addition, n-3 PUFAs have demonstrated anti-cancer effects in vitro and in vivo. Objective We investigated the anti-cancer effects and mechanism of action of EPA on PC3 prostate cancer cells in vitro. Methods PC3 cells were treated with various concentrations of EPA, and cell survival and the abilities of migration and invasion were evaluated. The time course of the growth inhibitory effect of EPA on PC3 cells was also assessed. The mechanism underlying the anti-cancer effects of EPA was investigated by human phosphokinase and human apoptosis antibody arrays, and confirmed by western blot analysis. We also examined the contribution of reactive oxygen species (ROS) to the effects of EPA using the ROS inhibitor N-acetyl cysteine. Results EPA decreased the survival of PC3 cells in a dose-dependent manner within 3 h of application, with an effective concentration of 500 μmol/L. EPA inhibited proline-rich tyrosine kinase (Pyk)2 and extracellular signal-regulated kinase 1/2 phosphorylation as determined by western blotting and the antibody arrays. The growth of PC3 cells was inhibited by EPA, which was dependent on ROS induction, while EPA inhibited Pyk2 phosphorylation independent of ROS production. Conclusions Inhibition of Pyk2 phosphorylation and ROS production contribute to the anticancer effects of EPA on PC3 cells.
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Affiliation(s)
- Keiichi Oono
- Laboratory of Physiology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
| | - Kazuo Ohtake
- Laboratory of Physiology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
| | - Chie Watanabe
- Laboratory of Clinical Pathology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
| | - Sachiko Shiba
- Laboratory of Physiology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
| | - Takashi Sekiya
- Laboratory of Clinical Pathology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
| | - Keizo Kasono
- Laboratory of Physiology, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan.
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Guo F, Si R, He J, Yuan L, Hai L, Ming L, Yi L, Ji R. Comprehensive transcriptome analysis of adipose tissue in the Bactrian camel reveals fore hump has more specific physiological functions in immune and endocrine systems. Livest Sci 2019. [DOI: 10.1016/j.livsci.2019.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Lopez E, Frischauf I, Jardin I, Derler I, Muik M, Cantonero C, Salido GM, Smani T, Rosado JA, Redondo PC. STIM1 phosphorylation at Y 316 modulates its interaction with SARAF and the activation of SOCE and ICRAC. J Cell Sci 2019; 132:jcs226019. [PMID: 30975919 DOI: 10.1242/jcs.226019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/08/2019] [Indexed: 01/24/2023] Open
Abstract
Stromal interaction molecule 1 (STIM1) is one of the key elements for the activation of store-operated Ca2+ entry (SOCE). Hence, identification of the relevant phosphorylatable STIM1 residues with a possible role in the regulation of STIM1 function and SOCE is of interest. By performing a computational analysis, we identified that the Y316 residue is susceptible to phosphorylation. Expression of the STIM1-Y316F mutant in HEK293, NG115-401L and MEG-01 cells resulted in a reduction in STIM1 tyrosine phosphorylation, SOCE and the Ca2+ release-activated Ca2+ current (ICRAC). STIM1-Orai1 colocalization was reduced in HEK293 cells transfected with YFP-STIM1-Y316F compared to in cells with wild-type (WT) YFP-tagged STIM1. Additionally, the Y316F mutation altered the pattern of interaction between STIM1 and SARAF under resting conditions and upon Ca2+ store depletion. Expression of the STIM1 Y316F mutant enhanced slow Ca2+-dependent inactivation (SCDI) as compared to STIM1 WT, an effect that was abolished by SARAF knockdown. Finally, in NG115-401L cells transfected with shRNA targeting SARAF, expression of STIM1 Y316F induced greater SOCE than STIM1 WT. Taken together, our results provide evidence supporting the idea that phosphorylation of STIM1 at Y316 plays a relevant functional role in the activation and modulation of SOCE.
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Affiliation(s)
- Esther Lopez
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Irene Frischauf
- Molecular & Membrane Biophysics, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Isaac Jardin
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Isabella Derler
- Molecular & Membrane Biophysics, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Martin Muik
- Molecular & Membrane Biophysics, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Carlos Cantonero
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Gines M Salido
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Tarik Smani
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville (IBiS)/University of Seville/CIBERCV, 41013 Seville, Spain
| | - Juan A Rosado
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Pedro C Redondo
- Department of Physiology, Cell Physiology Research Group, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
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Xie Y, Perrino BA. Quantitative in situ proximity ligation assays examining protein interactions and phosphorylation during smooth muscle contractions. Anal Biochem 2019; 577:1-13. [PMID: 30981700 DOI: 10.1016/j.ab.2019.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/21/2019] [Accepted: 04/10/2019] [Indexed: 12/26/2022]
Abstract
Antibody-based in situ proximity ligation assays (isPLA) have the potential to study protein phosphorylation and protein interactions with spatial resolution in intact tissues. However, the application of isPLA at the tissue level is limited by a lack of appropriate positive and negative controls and the difficulty in accounting for changes in tissue shape. Here we demonstrate a set of experimental and computational approaches using gastric fundus smooth muscles to improve the validity of quantitative isPLA. Appropriate positive and negative biological controls and PLA technical controls were selected to ensure experimental rigor. To account for changes in morphology between relaxed and contracted smooth muscles, target PLA spots were normalized to smooth muscle myosin light chain 20 PLA spots or the cellular cross-sectional areas. We describe the computational steps necessary to filter out false-positive improperly sized spots and set the thresholds for counting true positive PLA spots to quantify the PLA signals. We tested our approach by examining protein phosphorylation and protein interactions in smooth muscle myofilament Ca2+ sensitization pathways from resting and contracted gastric fundus smooth muscles. In conclusion, our tissue-level isPLA method enables unbiased quantitation of protein phosphorylation and protein-protein interactions in intact smooth muscle tissues, suggesting the potential for quantitative isPLA applications in other types of intact tissues.
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Affiliation(s)
- Yeming Xie
- Department of Physiology and Cell Biology, University of Nevada Reno, School of Medicine, MS 0352, 1664 N Virginia St, Reno, NV, 89557, USA
| | - Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada Reno, School of Medicine, MS 0352, 1664 N Virginia St, Reno, NV, 89557, USA.
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Maaliki D, Shaito AA, Pintus G, El-Yazbi A, Eid AH. Flavonoids in hypertension: a brief review of the underlying mechanisms. Curr Opin Pharmacol 2019; 45:57-65. [DOI: 10.1016/j.coph.2019.04.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/12/2019] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
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10
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Xie Y, Han KH, Grainger N, Li W, Corrigan RD, Perrino BA. A role for focal adhesion kinase in facilitating the contractile responses of murine gastric fundus smooth muscles. J Physiol 2018. [PMID: 29528115 DOI: 10.1113/jp275406] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
KEY POINTS Activation of focal adhesion kinase (FAK) by integrin signalling facilitates smooth muscle contraction by transmitting the force generated by myofilament activation to the extracellular matrix and throughout the smooth muscle tissue. Here we report that electrical field stimulation (EFS) of cholinergic motor neurons activates FAK in gastric fundus smooth muscles, and that FAK activation by EFS is atropine-sensitive but nicardipine-insensitive. PDBu and calyculin A contracted gastric fundus muscles Ca2+ -independently and also activated FAK. Inhibition of FAK activation inhibits the contractile responses evoked by EFS, and inhibits CPI-17 phosphorylation at T38. This study indicates that mechanical force or tension is sufficient to activate FAK, and that FAK appears to be involved in the activation of the protein kinase C-CPI-17 Ca2+ sensitization pathway in gastric fundus smooth muscles. These results reveal a novel role for FAK in gastric fundus smooth muscle contraction by facilitating CPI-17 phosphorylation. ABSTRACT Smooth muscle contraction involves regulating myosin light chain phosphorylation and dephosphorylation by myosin light chain kinase and myosin light chain phosphatase. C-kinase potentiated protein phosphatase-1 inhibitor of 17 kDa (CPI-17) and myosin phosphatase targeting subunit of myosin light-chain phosphatase (MYPT1) are crucial for regulating gastrointestinal smooth muscle contraction by inhibiting myosin light chain phosphatase. Integrin signalling involves the dynamic recruitment of several proteins, including focal adhesion kinase (FAK), to focal adhesions. FAK tyrosine kinase activation is involved in cell adhesion to the extracellular matrix via integrin signalling. FAK participates in linking the force generated by myofilament activation to the extracellular matrix and throughout the smooth muscle tissue. Here, we show that cholinergic stimulation activates FAK in gastric fundus smooth muscles. Electrical field stimulation in the presence of Nω -nitro-l-arginine methyl ester and MRS2500 contracted gastric fundus smooth muscle strips and increased FAK Y397 phosphorylation (pY397). Atropine blocked the contractions and prevented the increase in pY397. The FAK inhibitor PF-431396 inhibited the contractions and the increase in pY397. PF-431396 also inhibited the electrical field stimulation-induced increase in CPI-17 T38 phosphorylation, and reduced MYPT1 T696 and T853, and myosin light chain S19 phosphorylation. Ca2+ influx was unaffected by PF-431396. Nicardipine inhibited the contractions but had no effect on the increase in pY397. Phorbol 12,13-dibutyrate or calyculin A contracted gastric fundus smooth muscle strips Ca2+ independently and increased pY397. Our findings suggest that FAK is activated by mechanical forces during contraction and reveal a novel role of FAK in the regulation of CPI-17 phosphorylation.
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Affiliation(s)
- Yeming Xie
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, 89557, USA
| | - Koon Hee Han
- Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Republic of Korea
| | - Nathan Grainger
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, 89557, USA
| | - Wen Li
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, 89557, USA
| | - Robert D Corrigan
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, 89557, USA
| | - Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, 89557, USA
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11
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Utepbergenov D, Hennig PM, Derewenda U, Artamonov MV, Somlyo AV, Derewenda ZS. Bacterial Expression, Purification and In Vitro Phosphorylation of Full-Length Ribosomal S6 Kinase 2 (RSK2). PLoS One 2016; 11:e0164343. [PMID: 27732676 PMCID: PMC5061434 DOI: 10.1371/journal.pone.0164343] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/24/2016] [Indexed: 02/06/2023] Open
Abstract
Ribosomal S6 kinases (RSK) play important roles in cell signaling through the mitogen-activated protein kinase (MAPK) pathway. Each of the four RSK isoforms (RSK1-4) is a single polypeptide chain containing two kinase domains connected by a linker sequence with regulatory phosphorylation sites. Here, we demonstrate that full-length RSK2-which is implicated in several types of cancer, and which is linked to the genetic Coffin-Lowry syndrome-can be overexpressed with high yields in Escherichia coli as a fusion with maltose binding protein (MBP), and can be purified to homogeneity after proteolytic removal of MBP by affinity and size-exclusion chromatography. The purified protein can be fully activated in vitro by phosphorylation with protein kinases ERK2 and PDK1. Compared to full-length RSK2 purified from insect host cells, the bacterially expressed and phosphorylated murine RSK2 shows the same levels of catalytic activity after phosphorylation, and sensitivity to inhibition by RSK-specific inhibitor SL0101. Interestingly, we detect low levels of phosphorylation in the nascent RSK2 on Ser386, owing to autocatalysis by the C-terminal domain, independent of ERK. This observation has implications for in vivo signaling, as it suggests that full activation of RSK2 by PDK1 alone is possible, circumventing at least in some cases the requirement for ERK.
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Affiliation(s)
- Darkhan Utepbergenov
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America
| | - Paulina M Hennig
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America.,Department of Molecular Genetics, University of Lodz, Lodz, Poland
| | - Urszula Derewenda
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America
| | - Mykhaylo V Artamonov
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America
| | - Avril V Somlyo
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America
| | - Zygmunt S Derewenda
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, Virginia, United States of America
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Nicholson CJ, Seta F, Lee S, Morgan KG. MicroRNA-203 mimics age-related aortic smooth muscle dysfunction of cytoskeletal pathways. J Cell Mol Med 2016; 21:81-95. [PMID: 27502584 PMCID: PMC5192880 DOI: 10.1111/jcmm.12940] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/23/2016] [Indexed: 12/20/2022] Open
Abstract
Increased aortic stiffness is a biomarker for subsequent adverse cardiovascular events. We have previously reported that vascular smooth muscle Src-dependent cytoskeletal remodelling, which contributes to aortic plasticity, is impaired with ageing. Here, we use a multi-scale approach to determine the molecular mechanisms behind defective Src-dependent signalling in an aged C57BL/6 male mouse model. Increased aortic stiffness, as measured in vivo by pulse wave velocity, was found to have a comparable time course to that in humans. Bioinformatic analyses predicted several miRs to regulate Src-dependent cytoskeletal remodelling. qRT-PCR was used to determine the relative levels of predicted miRs in aortas and, notably, the expression of miR-203 increased almost twofold in aged aorta. Increased miR-203 expression was associated with a decrease in both mRNA and protein expression of Src, caveolin-1 and paxillin in aged aorta. Probing with phospho-specific antibodies confirmed that overexpression of miR-203 significantly attenuated Src and extracellular signal regulated kinase (ERK) signalling, which we have previously found to regulate vascular smooth muscle stiffness. In addition, transfection of miR-203 into aortic tissue from young mice increased phenylephrine-induced aortic stiffness ex vivo, mimicking the aged phenotype. Upstream of miR-203, we found that DNA methyltransferases (DNMT) 1, 3a, and 3b are also significantly decreased in the aged mouse aorta and that DNMT inhibition significantly increases miR-203 expression. Thus, the age-induced increase in miR-203 may be caused by epigenetic promoter hypomethylation in the aorta. These findings indicate that miR-203 promotes a re-programming of Src/ERK signalling pathways in vascular smooth muscle, impairing the regulation of stiffness in aged aorta.
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Affiliation(s)
| | - Francesca Seta
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Sophie Lee
- Department of Health Sciences, Boston University, Boston, MA, USA
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13
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Insight into muscle physiology through understanding mechanisms of muscle pathology. J Muscle Res Cell Motil 2015; 36:359-61. [PMID: 26671444 PMCID: PMC4762911 DOI: 10.1007/s10974-015-9437-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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