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Frew E, Sainty R, Chappell-Maor L, Bone C, Daskeviciute D, Russell S, Buhigas C, Iglesias-Platas I, Lartey J, Monk D. Differential expression of PPP1R12A transcripts, including those harbouring alternatively spliced micro-exons, in placentae from complicated pregnancies. Placenta 2024; 151:1-9. [PMID: 38615553 DOI: 10.1016/j.placenta.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 03/04/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
INTRODUCTION Placenta-associated pregnancy complications, including pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are conditions postulated to originate from initial failure of placentation, leading to clinical sequelae indicative of endothelial dysfunction. Vascular smooth muscle aberrations have also been implicated in the pathogenesis of both disorders via smooth muscle contractility and relaxation mediated by Myosin Light Chain Phosphatase (MLCP) and the oppositional contractile action of Myosin Light Chain Kinase. PPP1R12A is a constituent part of the MLCP complex responsible for dephosphorylation of myosin fibrils. We hypothesize that alternative splicing of micro-exons result in isoforms lacking the functional leucine zipper (LZ) domain which may give those cells expressing these alternative transcripts a tendency towards contraction and vasoconstriction. METHODS Expression was determined by qRT-PCR. Epigenetic profiling consisted of bisulphite-based DNA methylation analysis and ChIP for underlying histone modifications. RESULTS We identified several novel transcripts with alternative micro-exon inclusion that would produce LZ- PPP1R12A protein. qRT-PCR revealed some isoforms, including the PPP1R12A canonical transcript, are differentially expressed in placenta biopsies from PE and IUGR samples compared to uncomplicated pregnancies. DISCUSSION We propose that upregulation of PPP1R12A expression in complicated pregnancies may be due to enhanced promoter activity leading to increased transcription as a response to physiological stress in the placenta, which we show is independent of promoter DNA methylation.
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Affiliation(s)
- Edward Frew
- Department of Obstetrics and Gynaecology, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK
| | - Rebecca Sainty
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Louise Chappell-Maor
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Caitlin Bone
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Dagne Daskeviciute
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Sarah Russell
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Claudia Buhigas
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Isabel Iglesias-Platas
- Neonatal Unit, Institut de Recerca, Sant Joan de Déu, Barcelona, Spain; Neonatal Research, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK
| | - Jon Lartey
- Department of Obstetrics and Gynaecology, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK; Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK
| | - David Monk
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
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Chen Y, Wang L, Xu X, Li K, Sun Y, Wang Y, Wang DW. Genetic architecture of thoracic aortic dissection in the female population. Gene 2023; 887:147727. [PMID: 37625564 DOI: 10.1016/j.gene.2023.147727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/12/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023]
Abstract
BACKGROUND Sex-related differences in cardiovascular disease are now gaining much more attention and their importance is increasingly being recognized, but little is known about the genetic distribution, genotype-phenotype correlation, and outcomes in the female population with thoracic aortic dissection (TAD). METHODS One hundred seventy-nine Chinese female probands with TAD were enrolled from Tongji Hospital between October 2009 and October 2020. Genetic analysis was performed among 12 genes, and participants were subsequently followed up for a median of 38.2 months for TAD-related death. RESULTS We identified 18 pathogenic or likely pathogenic variants among 18 (10.1%) probands and 21 variants of uncertain significance in 21 (11.7%) patients. Individuals with positive variants presented with a significant risk of TAD (OR: 12.0, 95% CI: 5.87-26.8), and an association between FBN1 (p = 2.60E-11, OR = 19.8), MYLK (p = 0.006, OR = 14.0) variants and an increased risk for female TAD was identified as well. Furthermore, nearly half of the variants were found in the FBN1 gene, which was significantly linked to early aortic dissection and tended to cause death at a young age. CONCLUSION This study revealed the monogenic contribution of known TAD genes to the female TAD population with East Asian ancestry. Patients who tested positive for FBN1 were significantly younger at the time of aortic dissection and had a higher probability of dying at an early age.
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Affiliation(s)
- Yanghui Chen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Linlin Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Xin Xu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Ke Li
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Yang Sun
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, PR China; Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Wuhan 430000, PR China.
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P K M, C J, T N, F A L, M Harshan H, R S A, S A. Etiology behind canine uterine inertia: Role of uterine expression of MLCK4, MYH2, and PKC genes. Anim Reprod Sci 2023; 256:107298. [PMID: 37499285 DOI: 10.1016/j.anireprosci.2023.107298] [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: 03/30/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023]
Abstract
Dystocia is an obstetrical emergency, and primary uterine inertia (PUI) is the major etiological reason among the more prevalent maternal causes in dogs. The present study involved the relative expression analysis of genes associated with myometrial contraction in medium-sized dog breeds with uterine inertia. Dogs without any progress in the parturition process even after four hours of the onset of labor and the absence of uterine contractions were considered to have complete primary uterine inertia (CPUI, n = 9). Dogs that had expelled at least one fetus and made no further progress in parturition in the absence of active uterine contraction were considered to be experiencing partial primary uterine inertia (PPUI, n = 6). Dogs with the fetal cause of dystocia (FCD), i.e., obstructive dystocia, were taken as the third (n = 7) group. Uterine tissue samples were collected during cesarean section in each group, RNA was isolated, and the relative expression of myometrial ACTA2, ACTG2, MLCK4, MYH2, and PKC genes was analyzed. The MLCK4 gene expression was downregulated in CPUI (P ≤ 0.05) and PPUI (P ≤ 0.01) when compared to FCD. The MYH2 gene expression was downregulated in PPUI in comparison to CPUI (P ≤ 0.01) and FCD (P ≤ 0.05). The PKC gene expression was upregulated in PPUI in comparison to FCD and CPUI (P ≤ 0.05). The downregulation of MLCK4 and MYH2 gene expressions recorded in PPUI indicated the possibility of myometrial defects. The possibility of myometrial defects was also observed in CPUI, but to a lesser degree, suggesting other etiologies.
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Affiliation(s)
- Magnus P K
- Department of Animal Reproduction Gynaecology and Obstetrics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India.
| | - Jayakumar C
- Department of Animal Reproduction Gynaecology and Obstetrics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
| | - Naicy T
- Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
| | - Lali F A
- Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
| | - Hiron M Harshan
- Department of Animal Reproduction Gynaecology and Obstetrics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
| | - Abhilash R S
- Department of Animal Reproduction Gynaecology and Obstetrics, College of Veterinary and Animal Sciences Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
| | - Ajithkumar S
- University Veterinary Hospital and Teaching Veterinary Clinical Complex, Mannuthy, Kerala Veterinary and Animal Sciences University, Thrissur, Kerala, India
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Prakash E, Pavithra S, Kishor Kumar DG, Panigrahi M, Singh TU, Kumar D, Parida S. TXA2 mediates LPA1-stimulated uterine contraction in late pregnant mouse. Prostaglandins Other Lipid Mediat 2023; 167:106736. [PMID: 37062326 DOI: 10.1016/j.prostaglandins.2023.106736] [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: 02/10/2023] [Revised: 04/10/2023] [Accepted: 04/13/2023] [Indexed: 04/18/2023]
Abstract
Lysophosphatidic acid (LPA) is known to increase uterine contraction in the estrus cycle and early pregnancy, however, the effect of LPA in late pregnant uterus and its mechanisms are not clear. In the present study, we show the LPA receptor subtypes expressed and the mechanism of LPA-induced contractions in late pregnant mouse uterus. We determined the relative mRNA expression of LPA receptor genes by quantitative PCR and elicited log concentration-response curves to oleoyl-L-α-LPA by performing tension experiments in the presence and absence of nonselective and selective receptor antagonists and inhibitors of the TXA2 pathway. LPA1 was the most highly expressed receptor subtype in the late pregnant mouse uterus and LPA1/2/3 agonist (Oleoyl-L-α LPA) elicited increased contractions in this tissue that had lesser efficacy compared to oxytocin. LPA1/3 antagonist, Ki-16425, and a potent LPA1 antagonist (AM-095) significantly inhibited the LPA-induced contractions. Further, the nonselective COX inhibitor, indomethacin, and potent thromboxane A2 synthase inhibitor, furegrelate significantly impaired LPA-induced contractions. Moreover, selective thromboxane receptor (TP) antagonist, SQ-29548, and Rho kinase inhibitor, Y-27632 almost eliminated LPA-induced uterine contractions. LPA1 stimulation elicits contractions in the late pregnant mouse uterus using the contractile prostanoid, TXA2 and may be targeted to induce labor in uterine dysfunctions/ dystocia.
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Affiliation(s)
- E Prakash
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - S Pavithra
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - D G Kishor Kumar
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - Manjit Panigrahi
- Division of Animal Genetics and Breeding, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - Thakur Uttam Singh
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - Dinesh Kumar
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India
| | - Subhashree Parida
- Division of Pharmacology and Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India.
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Takahashi-Kanemitsu A, Lu M, Knight CT, Yamamoto T, Hayashi T, Mii Y, Ooki T, Kikuchi I, Kikuchi A, Barker N, Susaki EA, Taira M, Hatakeyama M. The Helicobacter pylori CagA oncoprotein disrupts Wnt/PCP signaling and promotes hyperproliferation of pyloric gland base cells. Sci Signal 2023; 16:eabp9020. [PMID: 37463245 DOI: 10.1126/scisignal.abp9020] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/24/2023] [Indexed: 07/20/2023]
Abstract
Helicobacter pylori strains that deliver the oncoprotein CagA into gastric epithelial cells are the major etiologic agents of upper gastric diseases including gastric cancer. CagA promotes gastric carcinogenesis through interactions with multiple host proteins. Here, we show that CagA also disrupts Wnt-dependent planar cell polarity (Wnt/PCP), which orients cells within the plane of an epithelium and coordinates collective cell behaviors such as convergent extension to enable epithelial elongation during development. Ectopic expression of CagA in Xenopus laevis embryos impaired gastrulation, neural tube formation, and axis elongation, processes driven by convergent extension movements that depend on the Wnt/PCP pathway. Mice specifically expressing CagA in the stomach epithelium had longer pyloric glands and mislocalization of the tetraspanin proteins VANGL1 and VANGL2 (VANGL1/2), which are critical components of Wnt/PCP signaling. The increased pyloric gland length was due to hyperproliferation of cells at the gland base, where Lgr5+ stem and progenitor cells reside, and was associated with fewer differentiated enteroendocrine cells. In cultured human gastric epithelial cells, the N terminus of CagA interacted with the C-terminal cytoplasmic tails of VANGL1/2, which impaired Wnt/PCP signaling by inducing the mislocalization of VANGL1/2 from the plasma membrane to the cytoplasm. Thus, CagA may contribute to the development of gastric cancer by subverting a Wnt/PCP-dependent mechanism that restrains pyloric gland stem cell proliferation and promotes enteroendocrine differentiation.
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Affiliation(s)
- Atsushi Takahashi-Kanemitsu
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Biochemistry and Systems Biomedicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Mengxue Lu
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Christopher Takaya Knight
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takayoshi Yamamoto
- Department of Biological Sciences, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Takuo Hayashi
- Department of Human Pathology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Yusuke Mii
- National Institute for Basic Biology and Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
| | - Takuya Ooki
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Laboratory of Microbial Carcinogenesis, Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Ippei Kikuchi
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Laboratory of Microbial Carcinogenesis, Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Akira Kikuchi
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| | - Nick Barker
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
- Division of Epithelial Stem Cell Biology, Cancer Research Institute, Kanazawa University, Kanazawa 924-1192, Japan
| | - Etsuo A Susaki
- Department of Biochemistry and Systems Biomedicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Masanori Taira
- Department of Biological Sciences, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Masanori Hatakeyama
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Laboratory of Microbial Carcinogenesis, Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, Shinagawa-ku, Tokyo 141-0021, Japan
- Research Center of Microbial Carcinogenesis, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan
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Assessing the Potency of the Novel Tocolytics 2-APB, Glycyl-H-1152, and HC-067047 in Pregnant Human Myometrium. Reprod Sci 2022; 30:203-220. [PMID: 35715551 PMCID: PMC9810572 DOI: 10.1007/s43032-022-01000-2] [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: 10/19/2021] [Accepted: 06/02/2022] [Indexed: 01/07/2023]
Abstract
The intracellular signaling pathways that regulate myometrial contractions can be targeted by drugs for tocolysis. The agents, 2-APB, glycyl-H-1152, and HC-067047, have been identified as inhibitors of uterine contractility and may have tocolytic potential. However, the contraction-blocking potency of these novel tocolytics was yet to be comprehensively assessed and compared to agents that have seen greater scrutiny, such as the phosphodiesterase inhibitors, aminophylline and rolipram, or the clinically used tocolytics, nifedipine and indomethacin. We determined the IC50 concentrations (inhibit 50% of baseline contractility) for 2-APB, glycyl-H-1152, HC-067047, aminophylline, rolipram, nifedipine, and indomethacin against spontaneous ex vivo contractions in pregnant human myometrium, and then compared their tocolytic potency. Myometrial strips obtained from term, not-in-labor women, were treated with cumulative concentrations of the contraction-blocking agents. Comprehensive dose-response curves were generated. The IC50 concentrations were 53 µM for 2-APB, 18.2 µM for glycyl-H-1152, 48 µM for HC-067047, 318.5 µM for aminophylline, 4.3 µM for rolipram, 10 nM for nifedipine, and 59.5 µM for indomethacin. A single treatment with each drug at the determined IC50 concentration was confirmed to reduce contraction performance (AUC) by approximately 50%. Of the three novel tocolytics examined, glycyl-H-1152 was the most potent inhibitor. However, of all the drugs examined, the overall order of contraction-blocking potency in decreasing order was nifedipine > rolipram > glycyl-H-1152 > HC-067047 > 2-APB > indomethacin > aminophylline. These data provide greater insight into the contraction-blocking properties of some novel tocolytics, with glycyl-H-1152, in particular, emerging as a potential novel tocolytic for preventing preterm birth.
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Frehner BL, Reichler IM, Kowalewski MP, Gram A, Keller S, Goericke-Pesch S, Balogh O. Implications of the RhoA/Rho associated kinase pathway and leptin in primary uterine inertia in the dog. J Reprod Dev 2021; 67:207-215. [PMID: 33746146 PMCID: PMC8238673 DOI: 10.1262/jrd.2020-141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The underlying functional and molecular changes in canine primary uterine inertia (PUI) are still not clarified. Leptin (Lep) and obesity negatively affect
uterine contractility in women, partly mediated by the RhoA/Rho associated kinase pathway, affecting myometrial calcium sensitization. We hypothesized that
increased uterine Lep/Lep receptor (LepR) or decreased RhoA/Rho associated kinase expression contributes to PUI in dogs, independent of obesity. Dogs presented
for dystocia were grouped into PUI (n = 11) or obstructive dystocia (OD, still showing strong labor contractions; n = 7). Interplacental full-thickness uterine
biopsies were collected during Cesarean section for relative gene expression (RGE) of RhoA, its effector kinases (ROCK1,
ROCK2), Lep and LepR by qPCR. Protein and/or mRNA expression and localization was evaluated by immunohistochemistry
and in situ hybridization. RGE was compared between groups by one-way ANOVA using body weight as covariate with statistical significance at P
< 0.05. Uterine ROCK1 and ROCK2 gene expression was significantly higher in PUI than OD, while RhoA and
Lep did not differ. LepR RGE was below the detection limit in five PUI and all OD dogs. Litter size had no influence. Lep,
LepR, RhoA, ROCK1, ROCK2 protein and/or mRNA were localized in the myometrium and endometrium. Uterine protein expression appeared similar between groups.
LepR mRNA signals appeared stronger in PUI than OD. In conclusion, lasting, strong labor contractions in OD likely resulted in downregulation
of uterine ROCK1 and ROCK2, contrasting the higher expression in PUI dogs with insufficient contractions. The Lep-LepR system
may affect uterine contractility in non-obese PUI dogs in a paracrine-autocrine manner.
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Affiliation(s)
- Bianca Lourdes Frehner
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Iris Margaret Reichler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | | | - Aykut Gram
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Department of Histology and Embryology, Faculty of Veterinary Medicine, Erciyes University, Turkey
| | - Stefanie Keller
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sandra Goericke-Pesch
- Section for Veterinary Reproduction and Obstetrics, Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark.,Reproductive Unit of the Clinics - Small Animal, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Orsolya Balogh
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, USA
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Misleading Westerns: Common Quantification Mistakes in Western Blot Densitometry and Proposed Corrective Measures. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5214821. [PMID: 30800670 PMCID: PMC6360618 DOI: 10.1155/2019/5214821] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/12/2018] [Indexed: 02/07/2023]
Abstract
Densitometry data generated for Western blots are commonly used to compare protein abundance between samples. In the last decade, it has become apparent that assumptions underpinning these comparisons are often violated in studies reporting Western blot data in the literature. These violations can lead to erroneous interpretations of data and may contribute to poor reproducibility of research. We assessed the reliability of Western blot data obtained to study human myometrial tissue proteins. We ran dilution series of protein lysates to explore the linearity of densitometry data. Proteins analysed included αSMA, HSP27, ERK1/2, and GAPDH. While ideal densitometry data are directly proportional to protein abundance, our data confirm that densitometry data often deviate from this ideal, in which case they can fit nonproportional linear or hyperbolic mathematical models and can reach saturation. Nonlinear densitometry data were observed when Western blots were detected using infrared fluorescence or chemiluminescence, and under different SDS-PAGE conditions. We confirm that ghosting artefacts associated with overabundance of proteins of interest in Western blots can skew findings. We also confirm that when data to be normalised are not directly proportional to protein abundance, it is a mistake to use the normalisation technique of dividing densitometry data from the protein-of-interest with densitometry data from loading control protein(s), as this can cause the normalised data to be unusable for making comparisons. Using spiked proteins in a way that allowed us to control the total protein amount per lane, while only changing the amount of spiked proteins, we confirm that nonlinearity and saturation of densitometry data, and errors introduced from normalisation processes, can occur in routine assays that compare equal amounts of lysate. These findings apply to all Western blot studies, and we highlight quality control checks that should be performed to make Western blot data more quantitative.
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Boyle AK, Rinaldi SF, Rossi AG, Saunders PTK, Norman JE. Repurposing simvastatin as a therapy for preterm labor: evidence from preclinical models. FASEB J 2018; 33:2743-2758. [PMID: 30312114 PMCID: PMC6338657 DOI: 10.1096/fj.201801104r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Preterm birth (PTB), the leading cause of neonatal morbidity and mortality, urgently requires novel therapeutic agents. Spontaneous PTB, resulting from preterm labor, is commonly caused by intrauterine infection/inflammation. Statins are well-established, cholesterol-lowering drugs that can reduce inflammation and inhibit vascular smooth muscle contraction. We show that simvastatin reduced the incidence of PTB in a validated intrauterine LPS-induced PTB mouse model, decreased uterine proinflammatory mRNA concentrations (IL-6, Cxcl1, and Ccl2), and reduced serum IL-6 concentration. In human myometrial cells, simvastatin reduced proinflammatory mediator mRNA and protein expression (IL-6 and IL-8) and increased anti-inflammatory cytokine mRNA expression (IL-10 and IL-13). Critically, simvastatin inhibited myometrial cell contraction, basally and during inflammation, and reduced phosphorylated myosin light chain concentration. Supplementation with mevalonate and geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate, abolished these anticontractile effects, indicating that the Rho/Rho-associated protein kinase pathway is critically involved. Thus, simvastatin reduces PTB incidence in mice, inhibits myometrial contractions, and exhibits key anti-inflammatory effects, providing a rationale for investigation into the repurposing of statins to treat preterm labor in women.—Boyle, A. K., Rinaldi, S. F., Rossi, A. G., Saunders, P. T. K., Norman, J. E. Repurposing simvastatin as a therapy for preterm labor: evidence from preclinical models.
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Affiliation(s)
- Ashley K Boyle
- Tommy's Centre for Maternal and Fetal Health, Medical Research Council (MRC) Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom; and
| | - Sara F Rinaldi
- Tommy's Centre for Maternal and Fetal Health, Medical Research Council (MRC) Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom; and
| | - Adriano G Rossi
- Medical Research Council (MRC) Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Philippa T K Saunders
- Medical Research Council (MRC) Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Jane E Norman
- Tommy's Centre for Maternal and Fetal Health, Medical Research Council (MRC) Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom; and
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Bafor EE, Onwukpa I, Itemire AO, Omoruyi O, Eferoba-Idio E, Odega K, Eghianruwa OJ. Amelioration ofEscherichia coli-induced endometritis with ascorbic acid in non-pregnant mouse models. Am J Reprod Immunol 2018; 80:e12976. [DOI: 10.1111/aji.12976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 04/16/2018] [Indexed: 12/01/2022] Open
Affiliation(s)
- Enitome Evi Bafor
- Department of Pharmacology & Toxicology; University of Benin; Benin City Edo State Nigeria
| | - Ikechukwu Onwukpa
- Department of Pharmacology & Toxicology; University of Benin; Benin City Edo State Nigeria
| | - Anne Oghenekevwe Itemire
- Department of Pharmaceutical Microbiology; Faculty of Pharmacy; University of Benin; Benin City Edo State Nigeria
| | - Osemelomen Omoruyi
- Department of Pharmacology & Toxicology; University of Benin; Benin City Edo State Nigeria
| | | | - Kevin Odega
- Department of Histopathology and Morbid Anatomy; University of Benin Teaching Hospital; Benin City Nigeria
| | - Osas Jim Eghianruwa
- Department of Anatomy; School of Basic Medical Sciences; University of Benin; Benin City Nigeria
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11
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Wang F, Sun Y. Overexpression of Myosin Phosphatase Target Subunit 1 (MYPT1) Inhibits Tumor Progression and Metastasis of Gastric Cancer. Med Sci Monit 2018; 24:2508-2517. [PMID: 29687789 PMCID: PMC5937360 DOI: 10.12659/msm.906852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background Myosin phosphatase target subunit 1 (MYPT1) serves as a subgroup of myosin phosphatases, and is frequently low-expressed in human cancers. However, little is known about the effects of MYPT1 in gastric cancer (GC). Material/Methods In our study, MYPT1 expression was detected by quantitative real-time reverse transcription PCR (qRT-PCR) in GC tissues, different advanced pathological stages of GC tissues, and preoperative and postoperative patients. Kaplan-Meier analysis was used to measure the overall survival of GC patients. MYPT1 expression was analyzed by qRT-PCR and Western blot assays in GES-1 cells and GC cells. Cell proliferation, cycle, and migration and invasion abilities were detected by CCK-8, flow cytometry, and Transwell assays. E-cadherin, TIMP-2, MMP-2, MMP-9 RhoA, and p-RhoA expressions were assessed by qRT-PCR and Western blot assays in treated SNU-5 cells. Results Our results indicated that MYPT1 was down-regulated in GC tissues and cells, and is related to clinical stages and overall survival of GC. Functional research demonstrated that overexpression of MYPT1 can inhibit cell proliferation, cell cycle progression, and migration and invasion of GC cells. Many studies on mechanisms reported that overexpression of MYPT1 dramatically improved the expression levels of cell cycle-related genes (Cyclin D1 and c-myc), significantly increased epithelial marker (E-cadherin) expression, and decreased invasion-associated genes (TIMP-2 and MMP-2) expressions in SNU-5 cells. In addition, we found that MYPT1 suppressed RhoA phosphorylation. Conclusions We verified that MYPT1 inhibits GC cell proliferation and metastasis by regulating RhoA phosphorylation.
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Affiliation(s)
- Fengyong Wang
- Department of Gastrointestinal and Pancreatic Surgery, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China (mainland)
| | - Yuanshui Sun
- Department of Gastrointestinal and Pancreatic Surgery, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China (mainland)
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12
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Jung J, Kwon M, Bae S, Yim S, Lee D. Petri net-based prediction of therapeutic targets that recover abnormally phosphorylated proteins in muscle atrophy. BMC SYSTEMS BIOLOGY 2018; 12:26. [PMID: 29506508 PMCID: PMC5838966 DOI: 10.1186/s12918-018-0555-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 02/21/2018] [Indexed: 11/23/2022]
Abstract
Background Muscle atrophy, an involuntary loss of muscle mass, is involved in various diseases and sometimes leads to mortality. However, therapeutics for muscle atrophy thus far have had limited effects. Here, we present a new approach for therapeutic target prediction using Petri net simulation of the status of phosphorylation, with a reasonable assumption that the recovery of abnormally phosphorylated proteins can be a treatment for muscle atrophy. Results The Petri net model was employed to simulate phosphorylation status in three states, i.e. reference, atrophic and each gene-inhibited state based on the myocyte-specific phosphorylation network. Here, we newly devised a phosphorylation specific Petri net that involves two types of transitions (phosphorylation or de-phosphorylation) and two types of places (activation with or without phosphorylation). Before predicting therapeutic targets, the simulation results in reference and atrophic states were validated by Western blotting experiments detecting five marker proteins, i.e. RELA, SMAD2, SMAD3, FOXO1 and FOXO3. Finally, we determined 37 potential therapeutic targets whose inhibition recovers the phosphorylation status from an atrophic state as indicated by the five validated marker proteins. In the evaluation, we confirmed that the 37 potential targets were enriched for muscle atrophy-related terms such as actin and muscle contraction processes, and they were also significantly overlapping with the genes associated with muscle atrophy reported in the Comparative Toxicogenomics Database (p-value < 0.05). Furthermore, we noticed that they included several proteins that could not be characterized by the shortest path analysis. The three potential targets, i.e. BMPR1B, ROCK, and LEPR, were manually validated with the literature. Conclusions In this study, we suggest a new approach to predict potential therapeutic targets of muscle atrophy with an analysis of phosphorylation status simulated by Petri net. We generated a list of the potential therapeutic targets whose inhibition recovers abnormally phosphorylated proteins in an atrophic state. They were evaluated by various approaches, such as Western blotting, GO terms, literature, known muscle atrophy-related genes and shortest path analysis. We expect the new proposed strategy to provide an understanding of phosphorylation status in muscle atrophy and to provide assistance towards identifying new therapies. Electronic supplementary material The online version of this article (10.1186/s12918-018-0555-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jinmyung Jung
- Bio-Synergy Research Center, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Republic of Korea.,Department of Applied Statistics, College of Economics and Business, The University of Suwon, Hwaseong-si, Gyeonggi-do, 18323, Republic of Korea
| | - Mijin Kwon
- Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Sunghwa Bae
- Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Soorin Yim
- Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Doheon Lee
- Bio-Synergy Research Center, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Republic of Korea. .,Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
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13
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Ilicic M, Butler T, Zakar T, Paul JW. The expression of genes involved in myometrial contractility changes during ex situ culture of pregnant human uterine smooth muscle tissue. J Smooth Muscle Res 2018; 53:73-89. [PMID: 28652518 PMCID: PMC5487834 DOI: 10.1540/jsmr.53.73] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Background: Ex situ analyses of human myometrial tissue has been used to
investigate the regulation of uterine quiescence and transition to a contractile
phenotype. Following concerns about the validity of cultured primary cells, we examined
whether myometrial tissue undergoes culture-induced changes ex situ that
may affect the validity of in vitro models. Objectives: To determine
whether human myometrial tissue undergoes culture-induced changes ex situ
in Estrogen receptor 1 (ESR1), Prostaglandin-endoperoxide synthase 2
(PTGS2) and Oxytocin receptor (OXTR) expression.
Additionally, to determine whether culture conditions approaching the in
vivo environment influence the expression of these key genes. Methods: Term
non-laboring human myometrial tissues were cultured in the presence of specific
treatments, including; serum supplementation, progesterone and estrogen, cAMP, PMA,
stretch or NF-κB inhibitors. ESR1, PTGS2 and
OXTR mRNA abundance after 48 h culture was determined using
quantitative RT-PCR. Results: Myometrial tissue in culture exhibited culture-induced
up-regulation of ESR1 and PTGS2 and down-regulation of
OXTR mRNA expression. Progesterone prevented culture-induced increase
in ESR1 expression. Estrogen further up-regulated PTGS2
expression. Stretch had no direct effect, but blocked the effects of progesterone and
estrogen on ESR1 and PTGS2 expression. cAMP had no
effect whereas PMA further up-regulated PTGS2 expression and prevented
decline of OXTR expression. Conclusion: Human myometrial tissue in
culture undergoes culture-induced gene expression changes consistent with transition
toward a laboring phenotype. Changes in ESR1, PTGS2 and
OXTR expression could not be controlled simultaneously. Until optimal
culture conditions are determined, results of in vitro experiments with
myometrial tissues should be interpreted with caution.
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Affiliation(s)
- Marina Ilicic
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia
| | - Trent Butler
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia
| | - Tamas Zakar
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia.,John Hunter Hospital, New Lambton Heights, NSW 2305, Australia
| | - Jonathan W Paul
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.,Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW 2308, Australia.,Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia
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14
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Yang S, Chen Z, Fan D, Zhang R, Zhang Y, Wu S. Retracted Article: MiR-182-5p and miR-96-5p increased hepatocellular carcinoma cell mobility, proliferation and cisplatin resistance partially by targeting RND3. RSC Adv 2018; 8:34973-34983. [PMID: 35547072 PMCID: PMC9087357 DOI: 10.1039/c8ra07055e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 09/19/2018] [Indexed: 11/30/2022] Open
Abstract
We investigated whether miR-182-5p or miR-96-5p could increase hepatocellular carcinoma (HCC) development by targeting Rho Family GTPase 3 (RND3) gene expression. The expression levels of miR-182-5p, miR-96-5p and mRNA/protein of RND3 in non-HCC liver tissue, HCC tissue and adjacent tissue specimens were evaluated by RT-qPCR and western blot. Patient-derived HCC cell culture was established, and miR-182-5p or miR-96-5p agomir or antagomir treatment was performed to mimic the overexpression or knockdown of the two miRNAs. HCC cell mobility in vitro was monitored by trans-well migration and invasion assay, while HCC cell growth in vitro was evaluated by cell viability, proliferation and apoptosis assay. HCC cell apoptosis was further investigated by caspase-3/-8/-9 activity assay. MiR-182-5p and miR-96-5p were significantly upregulated in HCC tissue specimens compared with non-HCC or adjacent tissue specimens, inversely correlating to RND3 mRNA expression level. Treatment with miR-182-5p or miR-96-5p agomir significantly reduced RND3 mRNA/protein expression level in HCC cells. MiR-182-5p- or miR-96-5p-targeting RND3 mRNA was verified by luciferase reporter assay and AGO2-RNA immunoprecipitation assay. MiR-182-5p or miR-96-5p agomir treatment significantly rescued HCC cell migration and invasion in vitro that were repressed by RND3 overexpression, during which ROCK1 and ROCK2 inhibition were involved. MiR-182-5p or miR-96-5p agomir treatment also increased HCC cell proliferation and cisplatin resistance in vitro, which could be antagonized by RND3 overexpression or ROCK inhibition. Thus, miR-182-5p and miR-96-5p increased HCC cell mobility, proliferation and cisplatin resistance in vitro partially by targeting RND3. We investigated whether miR-182-5p or miR-96-5p could increase hepatocellular carcinoma (HCC) development by targeting Rho Family GTPase 3 (RND3) gene expression.![]()
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Affiliation(s)
- Shiming Yang
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
| | - Zhi Chen
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
| | - Daguang Fan
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
| | - Rui Zhang
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
| | - Yuhong Zhang
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
| | - Shusheng Wu
- Department of General Surgery
- Shanxi Provincial People's Hospital
- Taiyuan
- China
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15
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Muñoz-Pérez VM, Fernández-Martínez E, Ponce-Monter H, Ortiz MI. Relaxant and anti-inflammatory effect of two thalidomide analogs as PDE-4 inhibitors in pregnant rat uterus. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:429-437. [PMID: 28706457 PMCID: PMC5507782 DOI: 10.4196/kjpp.2017.21.4.429] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 04/04/2017] [Accepted: 04/04/2017] [Indexed: 01/21/2023]
Abstract
The aim of this study was to evaluate the relaxant and anti-inflammatory effects of two thalidomide analogs as phosphodiesterase-4 (PDE-4) inhibitors in pregnant rat uterus. Uteri from Wistar female rats were isolated at 19 day of pregnancy. Uterine samples were used in functional studies to evaluate the inhibitory effects of the thalidomide analogs, methyl 3-(4-nitrophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4NO2PDPMe) and methyl 3-(4-aminophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4APDPMe), on prostaglandin-F2α (PGF2α)-induced phasic, K+-induced tonic, and Ca2+-induced contractions. Accumulation of cAMP was quantified in uterine homogenates by ELISA. Anti-inflammatory effect was assessed by using ELISA for determination of the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and anti-inflammatory IL-10, from uterine explants stimulated with lipopolysaccharide (LPS). Nifedipine, forskolin and rolipram were used as positive controls where required. Both thalidomide analogs induced a significant inhibition of the uterine contractions induced by the pharmaco- and electro-mechanic stimuli. Nifedipine and forskolin were more potent than the analogs to inhibit the uterine contractility, but these were more potent than rolipram, and 4APDPMe was equieffective to nifedipine. Thalidomide analogs increased uterine cAMP-levels in a concentration-dependent manner. The LPS-induced TNFα and IL-1β uterine secretion was diminished in a concentration-dependent fashion by both analogs, whereas IL-10 secretion was increased significantly. The thalidomide analogs induced utero-relaxant and anti-inflammatory effects, which were associated with the increased cAMP levels as PDE-4 inhibitors in the pregnant rat uterus. Such properties place these thalidomide analogs as potentially safe and effective tocolytic agents in a field that urgently needs improved pharmacological treatments, as in cases of preterm labor.
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Affiliation(s)
- Víctor Manuel Muñoz-Pérez
- Center for Research on Reproductive Biology, Academic Area of Medicine, Institute of Health Sciences, Autonomous University of Hidalgo's State, Pachuca, Hidalgo 42090, Mexico
| | - Eduardo Fernández-Martínez
- Center for Research on Reproductive Biology, Academic Area of Medicine, Institute of Health Sciences, Autonomous University of Hidalgo's State, Pachuca, Hidalgo 42090, Mexico
| | - Héctor Ponce-Monter
- Center for Research on Reproductive Biology, Academic Area of Medicine, Institute of Health Sciences, Autonomous University of Hidalgo's State, Pachuca, Hidalgo 42090, Mexico
| | - Mario I Ortiz
- Center for Research on Reproductive Biology, Academic Area of Medicine, Institute of Health Sciences, Autonomous University of Hidalgo's State, Pachuca, Hidalgo 42090, Mexico
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Modulation of Progesterone Receptor Isoform Expression in Pregnant Human Myometrium. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4589214. [PMID: 28540297 PMCID: PMC5433421 DOI: 10.1155/2017/4589214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 04/06/2017] [Indexed: 12/17/2022]
Abstract
Background. Regulation of myometrial progesterone receptor (PR) expression is an unresolved issue central to understanding the mechanism of functional progesterone withdrawal and initiation of labor in women. Objectives. To determine whether pregnant human myometrium undergoes culture-induced changes in PR isoform expression ex situ and, further, to determine if conditions approaching the in vivo environment stabilise PR isoform expression in culture. Methods. Term nonlaboring human myometrial tissues were cultured under specific conditions: serum supplementation, steroids, stretch, cAMP, PMA, PGF2α , NF-κB inhibitors, or TSA. Following 48 h culture, PR-T, PR-A, and PR-B mRNA levels were determined using qRT-PCR. PR-A/PR-B ratios were calculated. Results. PR-T and PR-A expression and the PR-A/PR-B ratio significantly increased in culture. Steroids prevented the culture-induced increase in PR-T and PR-A expression. Stretch blocked the effects of steroids on PR-T and PR-A expression. PMA further increased the PR-A/PR-B ratio, while TSA blocked culture-induced increases of PR-A expression and the PR-A/PR-B ratio. Conclusion. Human myometrial tissue in culture undergoes changes in PR gene expression consistent with transition toward a laboring phenotype. TSA maintained the nonlaboring PR isoform expression pattern. This suggests that preserving histone and/or nonhistone protein acetylation is critical for maintaining the progesterone dependent quiescent phenotype of human myometrium in culture.
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17
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Kang H, Liu J, Sun A, Liu X, Fan Y, Deng X. Vascular smooth muscle cell glycocalyx mediates shear stress-induced contractile responses via a Rho kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway. Sci Rep 2017; 7:42092. [PMID: 28191820 PMCID: PMC5304191 DOI: 10.1038/srep42092] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 01/04/2017] [Indexed: 11/09/2022] Open
Abstract
The vascular smooth muscle cells (VSMCs) are exposed to interstitial flow induced shear stress that may be sensed by the surface glycocalyx, a surface layer composed primarily of proteoglycans and glycoproteins, to mediate cell contraction during the myogenic response. We, therefore, attempted to elucidate the signal pathway of the glycocalyx mechanotransduction in shear stress regulated SMC contraction. Human umbilical vein SMCs (HUVSMCs) deprived of serum for 3–4 days were exposed to a step increase (0 to 20 dyn/cm2) in shear stress in a parallel plate flow chamber, and reduction in the cell area was quantified as contraction. The expressions of Rho kinase (ROCK) and its downstream signal molecules, the myosin-binding subunit of myosin phosphatase (MYPT) and the myosin light chain 2 (MLC2), were evaluated. Results showed that the exposure of HUVSMCs to shear stress for 30 min induced cell contraction significantly, which was accompanied by ROCK1 up-regulation, re-distribution, as well as MYPT1 and MLC activation. However, these shear induced phenomenon could be completely abolished by heparinase III or Y-27632 pre-treatment. These results indicate shear stress induced VSMC contraction was mediated by cell surface glycocalyx via a ROCK-MLC phosphatase (MLCP) pathway, providing evidence of the glycocalyx mechanotransduction in myogenic response.
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Affiliation(s)
- Hongyan Kang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
| | - Jiajia Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
| | - Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
| | - Xiao Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191 China
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18
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Hudson CA, López Bernal A. Phosphorylation of proteins during human myometrial contractions: A phosphoproteomic approach. Biochem Biophys Res Commun 2017; 482:1393-1399. [DOI: 10.1016/j.bbrc.2016.12.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 12/07/2016] [Indexed: 12/12/2022]
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19
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Lartey J, Taggart J, Robson S, Taggart M. Altered Expression of Human Smooth Muscle Myosin Phosphatase Targeting (MYPT) Isovariants with Pregnancy and Labor. PLoS One 2016; 11:e0164352. [PMID: 27798640 PMCID: PMC5087845 DOI: 10.1371/journal.pone.0164352] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 09/23/2016] [Indexed: 11/18/2022] Open
Abstract
Background Myosin light-chain phosphatase is a trimeric protein that hydrolyses phosphorylated myosin II light chains (MYLII) to cause relaxation in smooth muscle cells including those of the uterus. A major component of the phosphatase is the myosin targeting subunit (MYPT), which directs a catalytic subunit to dephosphorylate MYLII. There are 5 main MYPT family members (MYPT1 (PPP1R12A), MYPT2 (PPP1R12B), MYPT3 (PPP1R16A), myosin binding subunit 85 MBS85 (PPP1R12C) and TIMAP (TGF-beta-inhibited membrane-associated protein (PPP1R16B)). Nitric oxide (NO)-mediated smooth muscle relaxation has in part been attributed to activation of the phosphatase by PKG binding to a leucine zipper (LZ) dimerization domain located at the carboxyl-terminus of PPP1R12A. In animal studies, alternative splicing of PPP1R12A can lead to the inclusion of a 31-nucleotide exonic segment that generates a LZ negative (LZ-) isovariant rendering the phosphatase less sensitive to NO vasodilators and alterations in PPP1R12ALZ- and LZ+ expression have been linked to phenotypic changes in smooth muscle function. Moreover, PPP1R12B and PPP1R12C, but not PPP1R16A or PPP1R16B, have the potential for LZ+/LZ- alternative splicing. Yet, by comparison to animal studies, the information on human MYPT genomic sequences/mRNA expressions is scant. As uterine smooth muscle undergoes substantial remodeling during pregnancy we were interested in establishing the patterns of expression of human MYPT isovariants during this process and also following labor onset as this could have important implications for determining successful pregnancy outcome. Objectives We used cross-species genome alignment, to infer putative human sequences not available in the public domain, and isovariant-specific quantitative PCR, to analyse the expression of mRNA encoding putative LZ+ and LZ- forms of PPP1R12A, PPP1R12B and PPP1R12C as well as canonical PPP1R16A and PPP1R16B genes in human uterine smooth muscle from non-pregnant, pregnant and in-labor donors. Results We found a reduction in the expression of PPP1R12A, PPP1R12BLZ+, PPP1R16A and PPP1R16B mRNA in late pregnancy (not-in-labor) relative to non-pregnancy. PPP1R12ALZ+ and PPP1R12ALZ- mRNA levels were similar in the non-pregnant and pregnant not in labor groups. There was a further reduction in the uterine expression of PPP1R12ALZ+, PPP1R12CLZ+ and PPP1R12ALZ- mRNA with labor relative to the pregnant not-in-labor group. PPP1R12A, PPP1R12BLZ+, PPP1R16A and PPP1R16B mRNA levels were invariant between the not in labor and in-labor groups. Conclusions MYPT proteins are crucial determinants of smooth muscle function. Therefore, these alterations in human uterine smooth muscle MYPT isovariant expression during pregnancy and labor may be part of the important molecular physiological transition between uterine quiescence and activation.
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Affiliation(s)
- Jon Lartey
- Institute of Cellular Medicine, William Leech Building, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, United Kingdom, NE2 4HH
- * E-mail:
| | - Julie Taggart
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, United Kingdom, NE1 3BZ
| | - Stephen Robson
- Institute of Cellular Medicine, William Leech Building, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, United Kingdom, NE2 4HH
| | - Michael Taggart
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, United Kingdom, NE1 3BZ
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Fernández-Martínez E, Ponce-Monter H, Soria-Jasso LE, Ortiz MI, Arias-Montaño JA, Barragán-Ramírez G, Mayén-García C. Inhibition of Uterine Contractility by Thalidomide Analogs via Phosphodiesterase-4 Inhibition and Calcium Entry Blockade. Molecules 2016; 21:molecules21101332. [PMID: 27739411 PMCID: PMC6273742 DOI: 10.3390/molecules21101332] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/21/2016] [Accepted: 09/30/2016] [Indexed: 12/02/2022] Open
Abstract
Uterine relaxation is crucial during preterm labor. Phosphodiesterase-4 (PDE-4) inhibitors have been proposed as tocolytics. Some thalidomide analogs are PDE-4 inhibitors. The aim of this study was to assess the uterus-relaxant properties of two thalidomide analogs, methyl 3-(4-nitrophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4NO2PDPMe) and methyl 3-(4-aminophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4APDPMe) and were compared to rolipram in functional studies of spontaneous phasic, K+-induced tonic, and Ca2+-induced contractions in isolated pregnant human myometrial tissues. The accumulation of cAMP was quantified in HeLa cells. The presence of PDE-4B2 and phosphorylated myosin light-chain (pMLC), in addition to the effect of thalidomide analogs on oxytocin-induced pMLC, were assessed in human uterine myometrial cells (UtSMCs). Thalidomide analogs had concentration-dependent inhibitory effects on spontaneous and tonic contractions and inhibited Ca2+-induced responses. Tonic contraction was equipotently inhibited by 4APDPMe and rolipram (IC50 = 125 ± 13.72 and 98.45 ± 8.86 µM, respectively). Rolipram and the thalidomide analogs inhibited spontaneous and tonic contractions equieffectively. Both analogs increased cAMP accumulation in a concentration-dependent manner (p < 0.05) and induced changes in the subcellular localization of oxytocin-induced pMLC in UtSMCs. The inhibitory effects of thalidomide analogs on the contractions of pregnant human myometrium tissue may be due to their PDE-4 inhibitory effect and novel mechanism as calcium-channel blockers.
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Affiliation(s)
- Eduardo Fernández-Martínez
- Centro de Investigación en Biología de la Reproducción, Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Hidalgo, México.
| | - Héctor Ponce-Monter
- Centro de Investigación en Biología de la Reproducción, Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Hidalgo, México.
| | - Luis E Soria-Jasso
- Centro de Investigación en Biología de la Reproducción, Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Hidalgo, México.
| | - Mario I Ortiz
- Centro de Investigación en Biología de la Reproducción, Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Hidalgo, México.
| | - José-Antonio Arias-Montaño
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, México City 07360, México.
| | | | - Cynthia Mayén-García
- Centro de Investigación en Biología de la Reproducción, Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Hidalgo, México.
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Lai PF, Tribe RM, Johnson MR. Differential impact of acute and prolonged cAMP agonist exposure on protein kinase A activation and human myometrium contractile activity. J Physiol 2016; 594:6369-6393. [PMID: 27328735 DOI: 10.1113/jp272320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/30/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Over 15 million babies are born prematurely each year with approximately 1 million of these babies dying as a direct result of preterm delivery. β2 -Adrenoreceptor agonists that act via cAMP can reduce uterine contractions to delay preterm labour, but their ability to repress uterine contractions lasts ≤ 48 h and their use does not improve neonatal outcomes. Previous research has suggested that cAMP inhibits myometrial contractions via protein kinase A (PKA) activation, but this has yet to be demonstrated with PKA-specific agonists. We investigated the role of PKA in mediating cAMP-induced human myometrial relaxation, and the impact of prolonged cAMP elevation on myometrial contractility. Our findings suggest that PKA is not the sole mediator of cAMP-induced myometrial relaxation and that prolonged prophylactic elevation of cAMP alone is unlikely to prevent preterm labour (PTL). ABSTRACT Acute cAMP elevation inhibits myometrial contractility, but the mechanisms responsible are not fully elucidated and the long-term effects are uncertain. Both need to be defined in pregnant human myometrium before the therapeutic potential of cAMP-elevating agents in the prevention of preterm labour can be realised. In the present study, we tested the hypotheses that PKA activity is necessary for cAMP-induced myometrial relaxation, and that prolonged cAMP elevation can prevent myometrial contractions. Myometrial tissues obtained from term, pre-labour elective Caesarean sections were exposed to receptor-independent cAMP agonists to determine the relationship between myometrial contractility (spontaneous and oxytocin-induced), PKA activity, HSP20 phosphorylation and expression of contraction-associated and cAMP signalling proteins. Acute (1 h) application of cAMP agonists promoted myometrial relaxation, but this was weakly related to PKA activation. A PKA-specific activator, 6-Bnz-cAMP, increased PKA activity (6.8 ± 2.0 mean fold versus vehicle; P = 0.0313) without inducing myometrial relaxation. Spontaneous myometrial contractility declined after 24 h but was less marked when tissues were constantly exposed to cAMP agonists, especially for 8-bromo-cAMP (4.3 ± 1.2 mean fold versus vehicle; P = 0.0043); this was associated with changes to calponin, cofilin and HSP20 phosphorylated/total protein levels. Oxytocin-induced contractions were unaffected by pre-incubation with cAMP agonists despite treatments being able to enhance PKA activity and HSP20 phosphorylation. These data suggest that cAMP-induced myometrial relaxation is not solely dependent on PKA activity and the ability of cAMP agonists to repress myometrial contractility is lost with prolonged exposure. We conclude that cAMP agonist treatment alone may not prevent preterm labour.
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Affiliation(s)
- Pei F Lai
- Academic Department of Obstetrics & Gynaecology, Imperial College London, London, SW10 9NH, UK
| | - Rachel M Tribe
- Division of Women's Health, Kings College London and Women's Health Academic Centre, Kings Health Partners, London, SE1 7EH, UK
| | - Mark R Johnson
- Academic Department of Obstetrics & Gynaecology, Imperial College London, London, SW10 9NH, UK.
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Investigating the effects of the Rho-kinase enzyme inhibitors AS1892802 and fasudil hydrochloride on the contractions of isolated pregnant rat myometrium. Eur J Obstet Gynecol Reprod Biol 2016; 202:45-50. [PMID: 27160814 DOI: 10.1016/j.ejogrb.2016.04.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/23/2016] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Rho-kinases (ROCKs), are one of the dynamic structures of the actin cytoskeleton and they mediate different biological processes, including regulation of calcium sensitivity of smooth muscle contraction. The activation of Rho A/ROCK system is thought to be effective on the termination time of the pregnancy process. The aim of this study, was to investigate in vitro effects of the ROCK enzyme inhibitors, clinically available fasudil hydrochloride, and a new promising inhibitor AS1892802, on the contractions of isolated pregnant rat myometrium. STUDY DESIGN Term pregnant Wistar albino rats (n=12), weighing 200-220g, were used in this study. Myometrial tissues obtained from rats were dissected into four full-thickness longitudinal muscle strips and then myometrial tension was recorded isometrically. The inhibitory effects of cumulative concentrations of AS1892802 and of fasudil hydrochloride in the presence and absence of ODQ (guanylate cyclase inhibitor), l-NAME (nitric oxide synthase inhibitor) and l-NNA (endothelial nitric oxide synthase inhibitor) on oxytocin-induced myometrial contractions were measured, and values for -log10EC50 (pD2) and mean maximal inhibition (Emax) were compared. RESULTS Both ROCK inhibitors, AS1892802 and fasudil hydrochloride starting from the concentrations of 10(-6)M reached statistical significance on contraction amplitude and frequency of myometrial strips (p<0.05). The inhibition of the amplitude and frequency of myometrial contractions was antagonized with ODQ (10(-5)M; only amplitude), l-NAME (3×10(-5)M) and l-NNA (10(-5)M) (p<0.05). CONCLUSION These results suggest that fasudil hydrochloride and AS1892802 may contribute to the development of new tocolytic drugs. We conclude that AS1892802 and fasudil hydrochloride perform this inhibitory effect partially through ROCK inhibition and the NO/cGMP pathway.
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Compressive stress induces dephosphorylation of the myosin regulatory light chain via RhoA phosphorylation by the adenylyl cyclase/protein kinase A signaling pathway. PLoS One 2015; 10:e0117937. [PMID: 25734240 PMCID: PMC4348516 DOI: 10.1371/journal.pone.0117937] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/05/2015] [Indexed: 01/22/2023] Open
Abstract
Mechanical stress that arises due to deformation of the extracellular matrix (ECM) either stretches or compresses cells. The cellular response to stretching has been actively studied. For example, stretching induces phosphorylation of the myosin regulatory light chain (MRLC) via the RhoA/RhoA-associated protein kinase (ROCK) pathway, resulting in increased cellular tension. In contrast, the effects of compressive stress on cellular functions are not fully resolved. The mechanisms for sensing and differentially responding to stretching and compressive stress are not known. To address these questions, we investigated whether phosphorylation levels of MRLC were affected by compressive stress. Contrary to the response in stretching cells, MRLC was dephosphorylated 5 min after cells were subjected to compressive stress. Compressive loading induced activation of myosin phosphatase mediated via the dephosphorylation of myosin phosphatase targeting subunit 1 (Thr853). Because myosin phosphatase targeting subunit 1 (Thr853) is phosphorylated only by ROCK, compressive loading may have induced inactivation of ROCK. However, GTP-bound RhoA (active form) increased in response to compressive stress. The compression-induced activation of RhoA and inactivation of its effector ROCK are contradictory. This inconsistency was due to phosphorylation of RhoA (Ser188) that reduced affinity of RhoA to ROCK. Treatment with the inhibitor of protein kinase A that phosphorylates RhoA (Ser188) induced suppression of compression-stimulated MRLC dephosphorylation. Incidentally, stretching induced phosphorylation of MRLC, but did not affect phosphorylation levels of RhoA (Ser188). Together, our results suggest that RhoA phosphorylation is an important process for MRLC dephosphorylation by compressive loading, and for distinguishing between stretching and compressing cells.
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Pan H, Xie Y, Li K, Hu D, Zhao J, Zheng X, Tang T. ROCK-regulated synergistic effect of macropore/nanowire topography on cytoskeletal distribution and cell differentiation. RSC Adv 2015. [DOI: 10.1039/c5ra19691d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Synergistic effect of cytoskeleton distribution on macro/nano surfaces led to higher intracellular tension and better differentiation performance.
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Affiliation(s)
- Houhua Pan
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Youtao Xie
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Kai Li
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Dandan Hu
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Jun Zhao
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Xuebin Zheng
- Key Laboratory of Inorganic Coating Materials
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Tingting Tang
- Shanghai Key Laboratory of Orthopaedic Implants
- Department of Orthopaedics
- Shanghai Ninth People's Hospital
- Shanghai JiaoTong University School of Medicine
- Shanghai 200011
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25
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Chen CP, Chen X, Qiao YN, Wang P, He WQ, Zhang CH, Zhao W, Gao YQ, Chen C, Tao T, Sun J, Wang Y, Gao N, Kamm KE, Stull JT, Zhu MS. In vivo roles for myosin phosphatase targeting subunit-1 phosphorylation sites T694 and T852 in bladder smooth muscle contraction. J Physiol 2014; 593:681-700. [PMID: 25433069 DOI: 10.1113/jphysiol.2014.283853] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 11/18/2014] [Indexed: 01/12/2023] Open
Abstract
KEY POINTS Force production and maintenance in smooth muscle is largely controlled by myosin regulatory light chain (RLC) phosphorylation, which relies on a balance between Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) activities. MYPT1 is the regulatory subunit of MLCP that biochemically inhibits MLCP activity via T694 or T852 phosphorylation in vitro. Here we separately investigated the contribution of these two phosphorylation sites in bladder smooth muscles by establishing two single point mutation mouse lines, T694A and T852A, and found that phosphorylation of MYPT1 T694, but not T852, mediates force maintenance via inhibition of MLCP activity and enhancement of RLC phosphorylation in vivo. Our findings reveal the role of MYPT1 T694/T852 phosphorylation in vivo in regulation of smooth muscle contraction. ABSTRACT Force production and maintenance in smooth muscle is largely controlled by different signalling modules that fine tune myosin regulatory light chain (RLC) phosphorylation, which relies on a balance between Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) activities. To investigate the regulation of MLCP activity in vivo, we analysed the role of two phosphorylation sites on MYPT1 (regulatory subunit of MLCP) that biochemically inhibit MLCP activity in vitro. MYPT1 is constitutively phosphorylated at T694 by unidentified kinases in vivo, whereas the T852 site is phosphorylated by RhoA-associated protein kinase (ROCK). We established two mouse lines with alanine substitution of T694 or T852. Isolated bladder smooth muscle from T852A mice displayed no significant changes in RLC phosphorylation or force responses, but force was inhibited with a ROCK inhibitor. In contrast, smooth muscles containing the T694A mutation showed a significant reduction of force along with reduced RLC phosphorylation. The contractile responses of T694A mutant smooth muscle were also independent of ROCK activation. Thus, phosphorylation of MYPT1 T694, but not T852, is a primary mechanism contributing to inhibition of MLCP activity and enhancement of RLC phosphorylation in vivo. The constitutive phosphorylation of MYPT1 T694 may provide a mechanism for regulating force maintenance of smooth muscle.
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Affiliation(s)
- Cai-Ping Chen
- Model Animal Research Center and MOE Key Laboratory of Animal Models of Disease, Nanjing University, Nanjing, China
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Arrowsmith S, Wray S. Oxytocin: its mechanism of action and receptor signalling in the myometrium. J Neuroendocrinol 2014; 26:356-69. [PMID: 24888645 DOI: 10.1111/jne.12154] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/14/2014] [Accepted: 03/28/2014] [Indexed: 12/17/2022]
Abstract
Oxytocin is a nonapeptide hormone that has a central role in the regulation of parturition and lactation. In this review, we address oxytocin receptor (OTR) signalling and its role in the myometrium during pregnancy and in labour. The OTR belongs to the rhodopsin-type (Class 1) of the G-protein coupled receptor superfamily and is regulated by changes in receptor expression, receptor desensitisation and local changes in oxytocin concentration. Receptor activation triggers a number of signalling events to stimulate contraction, primarily by elevating intracellular calcium (Ca(2+) ). This includes inositol-tris-phosphate-mediated store calcium release, store-operated Ca(2+) entry and voltage-operated Ca(2+) entry. We discuss each mechanism in turn and also discuss Ca(2+) -independent mechanisms such as Ca(2+) sensitisation. Because oxytocin induces contraction in the myometrium, both the activation and the inhibition of its receptor have long been targets in the management of dysfunctional and preterm labours, respectively. We discuss current and novel OTR agonists and antagonists and their use and potential benefit in obstetric practice. In this regard, we highlight three clinical scenarios: dysfunctional labour, postpartum haemorrhage and preterm birth.
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Affiliation(s)
- S Arrowsmith
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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27
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McDonald DA, Shi C, Shenkar R, Gallione CJ, Akers AL, Li S, De Castro N, Berg MJ, Corcoran DL, Awad IA, Marchuk DA. Lesions from patients with sporadic cerebral cavernous malformations harbor somatic mutations in the CCM genes: evidence for a common biochemical pathway for CCM pathogenesis. Hum Mol Genet 2014; 23:4357-70. [PMID: 24698976 DOI: 10.1093/hmg/ddu153] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cerebral cavernous malformations (CCMs) are vascular lesions affecting the central nervous system. CCM occurs either sporadically or in an inherited, autosomal dominant manner. Constitutional (germline) mutations in any of three genes, KRIT1, CCM2 and PDCD10, can cause the inherited form. Analysis of CCM lesions from inherited cases revealed biallelic somatic mutations, indicating that CCM follows a Knudsonian two-hit mutation mechanism. It is still unknown, however, if the sporadic cases of CCM also follow this genetic mechanism. We extracted DNA from 11 surgically excised lesions from sporadic CCM patients, and sequenced the three CCM genes in each specimen using a next-generation sequencing approach. Four sporadic CCM lesion samples (36%) were found to contain novel somatic mutations. Three of the lesions contained a single somatic mutation, and one lesion contained two biallelic somatic mutations. Herein, we also describe evidence of somatic mosaicism in a patient presenting with over 130 CCM lesions localized to one hemisphere of the brain. Finally, in a lesion regrowth sample, we found that the regrown CCM lesion contained the same somatic mutation as the original lesion. Together, these data bolster the idea that all forms of CCM have a genetic underpinning of the two-hit mutation mechanism in the known CCM genes. Recent studies have found aberrant Rho kinase activation in inherited CCM pathogenesis, and we present evidence that this pathway is activated in sporadic CCM patients. These results suggest that all CCM patients, including those with the more common sporadic form, are potentially amenable to the same therapy.
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Affiliation(s)
- David A McDonald
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA
| | - Changbin Shi
- Section of Neurosurgery, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
| | - Robert Shenkar
- Section of Neurosurgery, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
| | - Carol J Gallione
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA
| | - Amy L Akers
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA Angioma Alliance, Norfolk, VA 23517, USA
| | - Stephanie Li
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA
| | - Nicholas De Castro
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA
| | - Michel J Berg
- School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA and
| | - David L Corcoran
- Institute for Genome Sciences and Policy, Duke University, Durham, NC 27710, USA
| | - Issam A Awad
- Section of Neurosurgery, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
| | - Douglas A Marchuk
- Molecular Genetics and Microbiology Department, Duke University Medical Center, Durham, NC 27710, USA
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Aguilar HN, Tracey CN, Zielnik B, Mitchell BF. Rho-kinase mediates diphosphorylation of myosin regulatory light chain in cultured uterine, but not vascular smooth muscle cells. J Cell Mol Med 2014; 16:2978-89. [PMID: 22947248 PMCID: PMC4393726 DOI: 10.1111/j.1582-4934.2012.01625.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 08/09/2012] [Indexed: 11/27/2022] Open
Abstract
Phosphorylation of myosin regulatory light chain (RLC) triggers contraction in smooth muscle myocytes. Dephosphorylation of phosphorylated RLC (pRLC) is mediated by myosin RLC phosphatase (MLCP), which is negatively regulated by rho-associated kinase (ROK). We have compared basal and stimulated concentrations of pRLC in myocytes from human coronary artery (hVM), which has a tonic contractile pattern to myocytes from human uterus (hUM), which has a phasic contractile pattern. Our studies reveal fundamental differences between hVM and hUM regarding the mechanisms regulating phosphorylation RLC. Whereas hVM responded to stimulation by phosphorylation of RLC at S19, hUM responded by forming diphosphorylated RLC (at T18 and S19; ppRLC), which, compared to pRLC, causes two to threefold greater activation of myosin ATPase that provides energy to power the contraction. Importantly, the conversion of pRLC to ppRLC is mediated by ROK. In hUM, MLCP has high activity for ppRLC and this is inhibited by ROK through phosphorylation of the substrate targeting subunit (MYPT1) at T853. Inhibitors of ROK significantly reduce contractility in both hVM and hUM. We demonstrated that inhibition of ppRLC in phasic myocytes (hUM) is 100-fold more sensitive to ROK inhibitors than is pRLC in tonic myocytes (hVM). We speculate that these differences in phosphorylation of RLC might reflect evolution of different contractile patterns to perform distinct physiological functions. Furthermore, our data suggest that low concentrations of ROK inhibitors might inhibit uterine contractions with minimal effects on vascular tone, thus posing a novel strategy for prevention or treatment of conditions such as preterm birth.
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Affiliation(s)
- Hector N Aguilar
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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Lin G, Brownsey RW, MacLeod KM. Complex regulation of PKCβ2 and PDK-1/AKT by ROCK2 in diabetic heart. PLoS One 2014; 9:e86520. [PMID: 24466133 PMCID: PMC3896488 DOI: 10.1371/journal.pone.0086520] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 12/15/2013] [Indexed: 01/13/2023] Open
Abstract
Objectives The RhoA/ROCK pathway contributes to diabetic cardiomyopathy in part by promoting the sustained activation of PKCβ2 but the details of their interaction are unclear. The purpose of this study was to investigate if over-activation of ROCK in the diabetic heart leads to direct phosphorylation and activation of PKCβ2, and to determine if their interaction affects PDK-1/Akt signaling. Methods Regulation by ROCK of PKCβ2 and related kinases was investigated by Western blotting and co-immunoprecipitation in whole hearts and isolated cardiomyocytes from 12 to 14-week diabetic rats. Direct ROCK2 phosphorylation of PKCβ2 was examined in vitro. siRNA silencing was used to confirm role of ROCK2 in PKCβ2 phosphorylation in vascular smooth muscle cells cultured in high glucose. Furthermore, the effect of ROCK inhibition on GLUT4 translocation was determined in isolated cardiomyocytes by confocal microscopy. Results Expression of ROCK2 and expression and phosphorylation of PKCβ2 were increased in diabetic hearts. A physical interaction between the two kinases was demonstrated by reciprocal immunoprecipitation, while ROCK2 directly phosphorylated PKCβ2 at T641 in vitro. ROCK2 siRNA in vascular smooth muscle cells or inhibition of ROCK in diabetic hearts reduced PKCβ2 T641 phosphorylation, and this was associated with attenuation of PKCβ2 activity. PKCβ2 also formed a complex with PDK-1 and its target AKT, and ROCK inhibition resulted in upregulation of the phosphorylation of PDK-1 and AKT, and increased translocation of glucose transporter 4 (GLUT4) to the plasma membrane in diabetic hearts. Conclusion This study demonstrates that over-activation of ROCK2 contributes to diabetic cardiomyopathy by multiple mechanisms, including direct phosphorylation and activation of PKCβ2 and interference with the PDK-1-mediated phosphorylation and activation of AKT and translocation of GLUT4. This suggests that ROCK2 is a critical node in the development of diabetic cardiomyopathy and may be an effective target to improve cardiac function in diabetes.
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Affiliation(s)
- Guorong Lin
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Roger W. Brownsey
- Dept. of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Kathleen M. MacLeod
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
- * E-mail:
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Hutchinson JL, Rajagopal SP, Yuan M, Norman JE. Lipopolysaccharide promotes contraction of uterine myocytes
via
activation of Rho/ROCK signaling pathways. FASEB J 2013; 28:94-105. [DOI: 10.1096/fj.13-237040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- James L. Hutchinson
- Medical Research Council Centre for Reproductive HealthUniversity of EdinburghThe Queen's Medical Research InstituteEdinburghUK
| | - Shalini P. Rajagopal
- Medical Research Council Centre for Reproductive HealthUniversity of EdinburghThe Queen's Medical Research InstituteEdinburghUK
| | - Mei Yuan
- Medical Research Council Centre for Reproductive HealthUniversity of EdinburghThe Queen's Medical Research InstituteEdinburghUK
| | - Jane E. Norman
- Medical Research Council Centre for Reproductive HealthUniversity of EdinburghThe Queen's Medical Research InstituteEdinburghUK
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O’Brien M, Carbin S, Morrison JJ, Smith TJ. Decreased myometrial p160 ROCK-1 expression in obese women at term pregnancy. Reprod Biol Endocrinol 2013; 11:79. [PMID: 23948067 PMCID: PMC3765888 DOI: 10.1186/1477-7827-11-79] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 08/07/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Obesity is becoming an increasing problem in obstetric practice; it has led to an increase in the risk of caesarean delivery, prolonged pregnancy and dysfunctional labour. It has been postulated that many of these problems are as a result of abnormal myometrial contractility. The RhoA/Rho kinase pathway is involved in calcium sensitisation in the myometrium during labour and contributes to the phosphorylation of myosin phosphatase and thus continued myosin light chain activity, during uterine contractility. The aim of this study therefore, was to investigate the effect of obesity on the expression of various components of the RhoA/ROCK pathway in human myometrium at term pregnancy. METHODS Protein was isolated from myometrial biopsies obtained at elective caesarean section, at term pregnancy from obese women and from those with a normal body mass index. Western blotting was performed using specific primary antibodies to RhoA/ Rho kinase associated proteins. RESULTS The protein expression of p160 ROCK-1 was significantly decreased (P < 0.001) in the myometrium from women in the obese cohort (n = 22) at term pregnancy, compared to women of those of normal body mass index (n = 15). No alteration in expression of the other proteins investigated was noted. CONCLUSIONS The significant decrease in p160 ROCK-1 protein expression observed in the myometrium of obese women at late gestation may contribute to an inhibitory effect on contractility at labour, due to its contribution to calcium sensitisation and possibly other signalling pathways. These findings are relevant to the concept of compromised myometrial function in obese parturients.
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Affiliation(s)
- Margaret O’Brien
- Department of Obstetrics and Gynaecology, Clinical Sciences Institute, University College Hospital Galway, Galway, Ireland
| | - Shawna Carbin
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland, Galway University Road, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics and Gynaecology, Clinical Sciences Institute, University College Hospital Galway, Galway, Ireland
| | - Terry J Smith
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland, Galway University Road, Galway, Ireland
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Zhou Z, Guo F, Dou Y, Tang J, Huan J. Guanine nucleotide exchange factor-H1 signaling is involved in lipopolysaccharide-induced endothelial barrier dysfunction. Surgery 2013; 154:621-31. [PMID: 23859306 DOI: 10.1016/j.surg.2013.04.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/03/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Gram-negative bacterial lipopolysaccharide (LPS) leads to the pathologic increase of vascular leakage under septic conditions. However, the mechanisms behind LPS-induced vascular hyperpermeability remain incompletely understood. In this study, we tested hypothesis that guanine nucleotide exchange factor-H1 (GEF-H1) signaling might be a key pathway involved in endothelial cells (ECs) barrier dysfunction. METHODS The roles of GEF-H1 signaling pathway in LPS-induced ECs barrier dysfunction were accessed by Evans blue dye-labeled albumin (EB-albumin) leak across the human umbilical vein EC (HUVEC) monolayers and Western blot assays. Furthermore, the effect of GEF-H1 signaling on LPS-induced alteration of cytoskeletal proteins and disruption of cell-cell junctions were analyzed by immunofluorescent analysis and Western blot assays, respectively. RESULTS We found that LPS could rapidly activated GEF-H1/RhoA/Rho-associated protein kinase (ROCK) signaling pathway in ECs. The LPS-mediated increase in EB-albumin flux across human HUVECs monolayers could be prevented by GEF-H1 depletion or ROCK inactivation. ECs permeability is controlled by actin filaments and cell-cell contact protein complexes. Actin stress fiber formation and/or cell-cell contact proteins loss cause vascular barrier disruption. Here, GEF-H1 knockdown or ROCK inactivation both not only significantly inhibited LPS-induced actin stress fiber formation, phosphorylation of myosin light chain, and myosin-associated phosphatase type 1, but also suppressed LPS-induced loss of occludin, claudin-1, and vascular endothelial (VE)-cadherin in ECs, which suggested that LPS-induced stress fiber formation and cell-cell junctions disruption were closely associated with GEF-H1/RhoA/ROCK signaling activation. CONCLUSION Our findings indicate that GEF-H1/RhoA/ROCK pathway in ECs plays an important role in LPS-mediated alteration of cell morphology and disruption of cell-cell junctions, consequently regulate LPS-induced vascular permeability dysfunction.
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Affiliation(s)
- Zengding Zhou
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Abstract
OBJECTIVE This study aimed to investigate the effect of serum taken from patients with severe acute pancreatitis (SAP) on vascular endothelial permeability. METHODS The monolayer permeability of endothelial cells (ECs) was assessed. Morphological changes in ECs, induced by serum from patients with SAP were assessed. Expressions of RhoA, myosin light chain (MLC) phosphorylation, and VE-cadherin protein were detected by Western blot. RESULTS Compared with the control group, 20% SAP serum significantly increased endothelial monolayer permeability (P < 0.01), markedly induced transcellular F-actin redistribution with stress fiber formation and VE-cadherin derangement with fragmentations located at the cell borders, and increased gaps between ECs. Furthermore, Western blotting showed that SAP serum induced rapid activation of Rho protein, and markedly increased the level of phosphorylated MLC. However, pretreatment with Y-27632 (an inhibitor for Rho kinase) significantly inhibited endothelial hyperpermeability and the morphological changes of F-actin rearrangement and VE-cadherin redistribution. This was associated with a down-regulation of Rho protein expression and a reduction in the level of MLC phosphorylation. CONCLUSIONS The SAP serum induces the loss of vascular endothelial monolayer integrity, with endothelial F-actin stress fiber formation and VE-cadherin redistribution. One of the mechanisms for this process involves the activation of the Rho/Rho kinase signaling pathway.
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Bhetwal BP, Sanders KM, An C, Trappanese DM, Moreland RS, Perrino BA. Ca2+ sensitization pathways accessed by cholinergic neurotransmission in the murine gastric fundus. J Physiol 2013; 591:2971-86. [PMID: 23613531 DOI: 10.1113/jphysiol.2013.255745] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Ca(2+) sensitization of contraction has typically been investigated by bathing muscles in solutions containing agonists. However, it is unknown whether bath-applied agonists and enteric neurotransmission activate similar Ca(2+) sensitization mechanisms. We investigated protein kinase C (PKC)-potentiated phosphatase inhibitor protein of 17 kDa (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) phosphorylation in murine gastric fundus muscles stimulated by bath-applied carbachol (CCh) or cholinergic motor neurotransmission. CCh increased MYPT1 phosphorylation at Thr696 (pT696) and Thr853 (pT853), CPI-17 at Thr38 (pT38), and myosin light chain at Ser19 (pS19). Electrical field stimulation (EFS) only increased pT38. In the presence of neostigmine, EFS increased pT38, pT853 and pS19. In fundus muscles of W/W(v) mice, EFS alone increased pT38 and pT853. Atropine blocked all contractions and all increases in pT696, pT853, pT38 and pS19. The Rho kinase (ROCK) inhibitor SAR1x blocked increases in pT853 and pT696. The PKC inhibitors Go6976 and Gf109203x or nicardipine blocked increases in pT38 and pT696. These findings suggest that cholinergic motor neurotransmission activates PKC-dependent CPI-17 phosphorylation. Bath-applied CCh recruits additional ROCK-dependent MYPT1 phosphorylation due to exposure of the agonist to a wider population of muscarinic receptors. Intramuscular interstitial cells of Cajal (ICC-IMs) and cholinesterases restrict ACh accessibility to a select population of muscarinic receptors, possibly only those expressed by ICC-IMs. These results provide the first biochemical evidence for focalized (or synaptic-like) neurotransmission, rather than diffuse 'volume' neurotransmission in a smooth muscle tissue. Furthermore, these findings demonstrate that bath application of contractile agonists to gastrointestinal smooth muscles does not mimic physiological responses to cholinergic neurotransmission.
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Affiliation(s)
- Bhupal P Bhetwal
- University of Nevada School of Medicine, Physiology and Cell Biology, University of Nevada, Reno, CMM203E, Reno, NV 89557, USA
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Singh J, Rattan S. Role of PKC and RhoA/ROCK pathways in the spontaneous phasic activity in the rectal smooth muscle. Am J Physiol Gastrointest Liver Physiol 2013; 304:G723-31. [PMID: 23413252 PMCID: PMC4073911 DOI: 10.1152/ajpgi.00473.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The role of PKC and RhoA/ROCK pathways in the phasic activities in the rectal smooth muscles (RSM) in the basal state is not known. We examined this issue by determining the effects of PKC inhibitors (calphostin C and Gö-6850) and a ROCK inhibitor (Y-27632) on the slow-rate (~3/min) and fast-rate (~25/min) phasic activities. We also examined the corresponding signal transduction cascades and the PKC and ROCK enzymatic activities in the RSM in the basal state. PKC inhibition with calphostin C and Gö-6850 (10(-5) M) caused a significant decrease (~25%) in slow-rate (but not fast-rate) phasic activity (monitored by frequency and amplitude of contractions) of the RSM. Conversely, ROCK inhibition with Y-27632 (10(-5) M) caused a significant decrease not only in slow-rate, but also fast-rate, phasic activity caused by ROCK inhibition in the RSM. Western blot analysis revealed that the PKC inhibition-induced decrease in RSM phasic activity was associated with decreases in PKCα translocation, phosphorylated (Thr(38)) PKC-potentiated inhibitor (CPI-17), and phosphorylated (Thr(18)/Ser(19)) 20-kDa myosin regulatory light chain. Conversely, decreases in the phasic activity in the RSM by ROCK inhibition were accompanied by the additional decrease in phosphorylated (Thr(696)) myosin phosphatase target subunit 1. Data show that while PKC and RhoA/ROCK pathways play a significant role in slow-rate high-amplitude spontaneous phasic activity, only the RhoA/ROCK pathway primarily mediates fast-rate low-amplitude phasic activity, in the RSM. Such knowledge is important in the understanding of the pathophysiology of large intestinal motility disorders. Relative contributions of the PKC vs. the RhoA/ROCK pathway in the phasic activity remain to be determined.
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Affiliation(s)
- Jagmohan Singh
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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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.
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Affiliation(s)
- Trent Butler
- Mothers and Babies Research Centre, Faculty of Health, University of Newcastle, Callaghan, NSW 2308, Australia
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