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Goyal RK, Rattan S. Role of mechanoregulation in mast cell-mediated immune inflammation of the smooth muscle in the pathophysiology of esophageal motility disorders. Am J Physiol Gastrointest Liver Physiol 2024; 326:G398-G410. [PMID: 38290993 PMCID: PMC11213482 DOI: 10.1152/ajpgi.00258.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/15/2024] [Accepted: 01/29/2024] [Indexed: 02/01/2024]
Abstract
Major esophageal disorders involve obstructive transport of bolus to the stomach, causing symptoms of dysphagia and impaired clearing of the refluxed gastric contents. These may occur due to mechanical constriction of the esophageal lumen or loss of relaxation associated with deglutitive inhibition, as in achalasia-like disorders. Recently, immune inflammation has been identified as an important cause of esophageal strictures and the loss of inhibitory neurotransmission. These disorders are also associated with smooth muscle hypertrophy and hypercontractility, whose cause is unknown. This review investigated immune inflammation in the causation of smooth muscle changes in obstructive esophageal bolus transport. Findings suggest that smooth muscle hypertrophy occurs above the obstruction and is due to mechanical stress on the smooth muscles. The mechanostressed smooth muscles release cytokines and other molecules that may recruit and microlocalize mast cells to smooth muscle bundles, so that their products may have a close bidirectional effect on each other. Acting in a paracrine fashion, the inflammatory cytokines induce genetic and epigenetic changes in the smooth muscles, leading to smooth muscle hypercontractility, hypertrophy, and impaired relaxation. These changes may worsen difficulty in the esophageal transport. Immune processes differ in the first phase of obstructive bolus transport, and the second phase of muscle hypertrophy and hypercontractility. Moreover, changes in the type of mechanical stress may change immune response and effect on smooth muscles. Understanding immune signaling in causes of obstructive bolus transport, type of mechanical stress, and associated smooth muscle changes may help pathophysiology-based prevention and targeted treatment of esophageal motility disorders.NEW & NOTEWORTHY Esophageal disorders such as esophageal stricture or achalasia, and diffuse esophageal spasm are associated with smooth muscle hypertrophy and hypercontractility, above the obstruction, yet the cause of such changes is unknown. This review suggests that smooth muscle obstructive disorders may cause mechanical stress on smooth muscle, which then secretes chemicals that recruit, microlocalize, and activate mast cells to initiate immune inflammation, producing functional and structural changes in smooth muscles. Understanding the immune signaling in these changes may help pathophysiology-based prevention and targeted treatment of esophageal motility disorders.
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Affiliation(s)
- Raj K Goyal
- Division of Gastroenterology, Department of Medicine, Veterans Affairs Boston Healthcare System, West Roxbury, Massachusetts, United States
- Division of Gastroenterology, Hepatology, and Endoscopy, Department of Medicine, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts, United States
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology and Hepatology, Sidney Kummel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, United States
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Singh A, Singh J, Rattan S. Evidence for the presence and release of BDNF in the neuronal and non-neuronal structures of the internal anal sphincter. Neurogastroenterol Motil 2022; 34:e14099. [PMID: 33624396 PMCID: PMC9558559 DOI: 10.1111/nmo.14099] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/31/2020] [Accepted: 01/26/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Data on the neuromodulatory effects of brain-derived neurotrophic factor (BDNF) in the gastrointestinal tract were recently reported, but there are still no data on the presence, distribution, and release of BDNF in the gastrointestinal tract, including the internal anal sphincter (IAS). METHODS We examined the presence and distribution of BDNF and its receptor TrkB in the different IAS structures (neuronal and non-neuronal) via immunohistochemical and immunocytochemical analyses. We also monitored the release of BDNF in an IAS muscle bath (consisting of smooth muscle cells [SMCs], myenteric plexus, and submucosal plexus) before and after different agonists, and electrical field stimulation in the absence and presence of neurotoxin tetrodotoxin. KEY RESULTS BDNF/TrkB was found to be present in all layers of the IAS, especially the smooth muscle, mucosa, myenteric plexus, and submucosal plexus. Detailed analyses revealed a significant colocalization between BDNF and TrkB in different structures, especially in the smooth muscle, the SMCs, and both plexuses. Data further showed higher levels of BDNF in the cytosol and that of TrkB toward the periphery of the SMCs. CONCLUSIONS & INFERENCES These studies showed that BDNF/TrkB was present not only in the enteric nervous system (ENS), but also in the SMCs. For the neuromodulatory effects, BDNF is released locally from the ENS ((myenteric (10.01 ± 0.23 pg/ml) and submucosal plexus (9.05 ± 0.51 pg/ml)) and the SMCs (18.63 ± 1.63 pg/ml). Collectively, these findings have pathophysiological and therapeutic implications regarding the role of BDNF/TrkB in the IAS-associated rectoanal motility disorders.
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Affiliation(s)
- Arjun Singh
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College, Thomas Jefferson University, 1025 Walnut Street, Room #320 College, Philadelphia, Pennsylvania 19107, USA
| | - Jagmohan Singh
- Department of Pharmacology and Experimental Therapeutics, Jefferson Alumni Hall, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, USA
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College, Thomas Jefferson University, 1025 Walnut Street, Room #320 College, Philadelphia, Pennsylvania 19107, USA
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3
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Zou Z, Liu R, Liang Y, Zhou R, Dai Q, Han Z, Jiang M, Zhuo Y, Zhang Y, Feng Y, Zhu X, Cai S, Lin J, Tang Z, Zhong W, Liang Y. Identification and Validation of a PPP1R12A-Related Five-Gene Signature Associated With Metabolism to Predict the Prognosis of Patients With Prostate Cancer. Front Genet 2021; 12:703210. [PMID: 34484299 PMCID: PMC8414655 DOI: 10.3389/fgene.2021.703210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/28/2021] [Indexed: 01/23/2023] Open
Abstract
Background Prostate cancer (PCa) is the most common malignant male neoplasm in the American male population. Our prior studies have demonstrated that protein phosphatase 1 regulatory subunit 12A (PPP1R12A) could be an efficient prognostic factor in patients with PCa, promoting further investigation. The present study attempted to construct a gene signature based on PPP1R12A and metabolism-related genes to predict the prognosis of PCa patients. Methods The mRNA expression profiles of 499 tumor and 52 normal tissues were extracted from The Cancer Genome Atlas (TCGA) database. We selected differentially expressed PPP1R12A-related genes among these mRNAs. Tandem affinity purification-mass spectrometry was used to identify the proteins that directly interact with PPP1R12A. Gene set enrichment analysis (GSEA) was used to extract metabolism-related genes. Univariate Cox regression analysis and a random survival forest algorithm were used to confirm optimal genes to build a prognostic risk model. Results We identified a five-gene signature (PPP1R12A, PTGS2, GGCT, AOX1, and NT5E) that was associated with PPP1R12A and metabolism in PCa, which effectively predicted disease-free survival (DFS) and biochemical relapse-free survival (BRFS). Moreover, the signature was validated by two internal datasets from TCGA and one external dataset from the Gene Expression Omnibus (GEO). Conclusion The five-gene signature is an effective potential factor to predict the prognosis of PCa, classifying PCa patients into high- and low-risk groups, which might provide potential novel treatment strategies for these patients.
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Affiliation(s)
- Zhihao Zou
- Department of Geriatrics, The Second Affiliated Hospital of South China University of Technology, Guangzhou, China.,Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Ren Liu
- Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yingke Liang
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Rui Zhou
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Qishan Dai
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Zhaodong Han
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Minyao Jiang
- Department of Urology, Huadu District People's Hospital, Southern Medical University, Guangzhou, China
| | - Yangjia Zhuo
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Yixun Zhang
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Yuanfa Feng
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Xuejin Zhu
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Shanghua Cai
- Urology Key Laboratory of Guangdong Province, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
| | - Jundong Lin
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Zhenfeng Tang
- Urology Key Laboratory of Guangdong Province, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
| | - Weide Zhong
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China.,Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Urology Key Laboratory of Guangdong Province, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.,State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China
| | - Yuxiang Liang
- Department of Geriatrics, The Second Affiliated Hospital of South China University of Technology, Guangzhou, China.,Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Department of Urology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China.,Department of Urology, Huizhou Municipal Central Hospital, Huizhou, China
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Singh A, Rattan S. BDNF rescues aging-associated internal anal sphincter dysfunction. Am J Physiol Gastrointest Liver Physiol 2021; 321:G87-G97. [PMID: 34075793 PMCID: PMC8321795 DOI: 10.1152/ajpgi.00090.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Aging can lead to rectoanal incontinence due to internal anal sphincter (IAS) dysfunction, which is characterized by a decrease in IAS tone and contractility and an increase in nonadrenergic noncholinergic (NANC) relaxation. We aimed to determine whether brain-derived neurotropic factor (BDNF) rescues this aging-associated IAS dysfunction (AAID). To do so, we studied the effects of BDNF on the basal and G protein-coupled receptors (GPCR)-stimulated IAS smooth muscle tone and on NANC relaxation in Fischer 344 rats representing different age groups [26-mo-old (aging) vs. 6-mo-old (young)], before and after tyrosine kinase receptor B (TrkB) antagonist K252a. We also used isolated smooth muscle cells (SMCs) to determine the effects of BDNF before and after different agonists. For some studies, we monitored NO release using smooth muscle perfusates. BDNF reversed AAID by rescuing the basal IAS tone and agonists [thromboxane A2 analog (U46619) and angiotensin II (ANG II)]-induced contractility, and NANC relaxation. These rescue effects of BDNF were selective as K252a attenuated the changes in the IAS without modifying the effects of K+depolarization. Because of the direct association between the basal and GPCR-stimulated IAS tone and RhoA/ROCK activation, we speculate that this pathway in the rescue effects of BDNF. Conversely, our data suggest that aging-associated increased NANC relaxation is reversed by decreased release of NO and decrease in the sensitivity of the released inhibitory neurotransmitter. In summary, BDNF rescue of AAID involves RhoA/ROCK and inhibitory neurotransmission. These data have direct implications for the role of BDNF in the pathophysiology and therapeutic targeting of aging-associated rectoanal motility disorders.NEW & NOTEWORTHY These studies demonstrate that brain-derived neurotropic factor (BDNF) rescues the aging-associated internal anal sphincter (IAS) dysfunction, characterized by a decrease in IAS tone, and increase in non-adrenergic noncholinergic relaxation. We determined the effects of BDNF on the basal and GPCR (TXA2 and ANG II)-stimulated IAS tone, and on NANC relaxation, before and after TrkB inhibitor K252a. BDNF may have an important role in the pathophysiology and therapeutic targeting of certain rectoanal motility disorders.
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Affiliation(s)
- Arjun Singh
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Wu F, Li H, Zhang H, Liao Y, Ren H, Wu J, Zheng D. Phosphorylated‑myosin light chain mediates the destruction of small intestinal epithelial tight junctions in mice with acute liver failure. Mol Med Rep 2021; 23:392. [PMID: 33760163 PMCID: PMC8008219 DOI: 10.3892/mmr.2021.12031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Tight junction dysregulation and epithelial damage contribute to intestinal barrier loss in patients with acute liver failure (ALF); however, the regulatory mechanisms of these processes remain poorly understood. The aim of the present study was to investigate the changes of intestinal tight junction and intestinal mucosa in mice with ALF and their mechanisms. In the present study, ALF was induced in mice through an intraperitoneal injection of D-galactosamine and lipopolysaccharide (D-GalN/LPS), and the morphological changes of the liver or small intestine were analyzed using hematoxylin and eosin staining, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The intestinal tissues and isolated serum were analyzed using western blotting, immunofluorescence staining and ELISA. D-GalN/LPS-induced mice exhibited signs of hepatocyte necrosis, alongside inflammatory cell infiltration into the liver tissue and partial microvilli detachment in the small intestinal mucosa. TEM demonstrated that the intestinal epithelial tight junctions were impaired, whereas SEM micrographs revealed the presence of abnormal microvilli in D-GalN/LPS-induced mice. In addition, the expression levels of phosphorylated (p)-myosin light chain (MLC), MLC kinase (MLCK) and Rho-associated kinase (ROCK) were significantly increased in the D-GalN/LPS-induced mice compared with those in the control mice, whereas the subsequent inhibition of MLCK or ROCK significantly reduced p-MLC expression levels. Conversely, the expression levels of occludin and zonula occludens-1 (ZO-1) were significantly decreased in the D-GalN/LPS-induced mice, and the inhibition of MLCK or ROCK significantly increased occludin and ZO-1 protein expression levels compared with those in the control group. Changes in the serum levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were similar to the trend observed in p-MLC expression levels. In conclusion, the findings of the present study suggested that in a D-GalN/LPS-induced ALF model, TNF-α and IL-6 signaling may increase MLCK and ROCK expression levels, further mediate phosphorylation of MLC, which may result in tight junction dysregulation and intestinal barrier dysfunction.
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Affiliation(s)
- Fan Wu
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Hui Li
- Hepatology Unit and Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Heng Zhang
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Yusheng Liao
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Huanping Ren
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Jie Wu
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Dan Zheng
- Department of Gastroenterology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
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Abstract
The small GTPase RhoA participates in actin and microtubule machinery, cell migration and invasion, gene expression, vesicular trafficking and cell cycle, and its dysregulation is a determining factor in many pathological conditions. Similar to other Rho GTPases, RhoA is a key component of the wound-healing process, regulating the activity of different participating cell types. RhoA gets activated upon binding to guanine nucleotide exchange factors (GEFs), which catalyze the exchange of guanosine diphosphate (GDP) for guanosine triphosphate (GTP). GTPase-activating proteins (GAPs) mediate the exchange of GTP to GDP, inactivating RhoA, whereas guanine nucleotide dissociation inhibitors (GDIs) preserve the inactive pool of RhoA proteins in the cytosol. RhoA and Rho GEF activation is detected by protein pull-down assays, which use chimeric proteins with Rhotekin and G17A mutant RhoA as "bait" to pull down active RhoA and RhoA GEFs, respectively. In this chapter, we describe an optimized protocol for performing RhoA and GEF pull-down assays.
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Nelson M, Zhang X, Pan Z, Spechler SJ, Souza RF. Mast cell effects on esophageal smooth muscle and their potential role in eosinophilic esophagitis and achalasia. Am J Physiol Gastrointest Liver Physiol 2021; 320:G319-G327. [PMID: 33355505 DOI: 10.1152/ajpgi.00290.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mast cells and eosinophils are the key effector cells of allergic disorders. Although most studies on eosinophilic esophagitis (EoE), an allergic disorder of the esophagus, have focused on the role of eosinophils, recent studies suggest a major role for mast cells in causing the clinical manifestations of this disease. Cellular and animal studies have demonstrated that mast cells can cause esophageal muscle cells to proliferate and differentiate into a more contractile phenotype, and that mediators released by degranulating mast cells such as tryptase and histamine can activate smooth muscle contraction pathways. Thus, activated mast cells in the esophageal muscularis propria might cause esophageal motility abnormalities, including the failure of lower esophageal sphincter relaxation typical of achalasia. In addition, mast cells have been implicated in the pathogenesis of a number of neurodegenerative disorders of the central nervous system such as Alzheimer's and Parkinson's diseases, because degranulating mast cells release proinflammatory and cytotoxic mediators capable of damaging neurons. Such mast cell degranulation in the myenteric plexus of the esophagus could cause the loss of enteric neurons that characterizes achalasia. In this report, we review the molecular mechanisms of esophageal smooth muscle contraction, and how mast cells products might affect that muscle and cause neurodegeneration in the esophagus. Based on these data, we present our novel, conceptual model for an allergy-induced form of achalasia mediated by mast cell activation in the esophageal muscularis propria.
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Affiliation(s)
- Melissa Nelson
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas
| | - Xi Zhang
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas
| | - Zui Pan
- College of Nursing and Health Innovation, The University of Texas at Arlington, Arlington, Texas
| | - Stuart Jon Spechler
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas
| | - Rhonda F Souza
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas
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Gene expression in urinary incontinence and pelvic organ prolapse: a review of literature. Curr Opin Obstet Gynecol 2020; 32:441-448. [DOI: 10.1097/gco.0000000000000661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Li B, Wang R, Wang Y, Stief CG, Hennenberg M. Regulation of smooth muscle contraction by monomeric non-RhoA GTPases. Br J Pharmacol 2020; 177:3865-3877. [PMID: 32579705 PMCID: PMC7429483 DOI: 10.1111/bph.15172] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/05/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
Smooth muscle contraction in the cardiovascular system, airways, prostate and lower urinary tract is involved in the pathophysiology of many diseases, including cardiovascular and obstructive lung disease plus lower urinary tract symptoms, which are associated with high prevalence of morbidity and mortality. This prominent clinical role of smooth muscle tone has led to the molecular mechanisms involved being subjected to extensive research. In general smooth muscle contraction is promoted by three major signalling pathways, including the monomeric GTPase RhoA pathway. However, emerging evidence suggests that monomeric GTPases other than RhoA may be involved in signal transduction in smooth muscle contraction, including Rac GTPases, cell division control protein 42 homologue, adenosine ribosylation factor 6, Ras, Rap1b and Rab GTPases. Here, we review these emerging functions of non-RhoA GTPases in smooth muscle contraction, which has now become increasingly more evident and constitutes an emerging and innovative research area of high clinical relevance.
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Affiliation(s)
- Bingsheng Li
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Ruixiao Wang
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Yiming Wang
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Christian G Stief
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Martin Hennenberg
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
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Singh A, Mohanty I, Singh J, Rattan S. BDNF augments rat internal anal sphincter smooth muscle tone via RhoA/ROCK signaling and nonadrenergic noncholinergic relaxation via increased NO release. Am J Physiol Gastrointest Liver Physiol 2020; 318:G23-G33. [PMID: 31682160 PMCID: PMC6985850 DOI: 10.1152/ajpgi.00247.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Presently, there are no studies examining the neuromodulatory effects of brain-derived neurotropic factor (BDNF) on the basal internal anal sphincter (IAS) tone and nonadrenergic noncholinergic (NANC) relaxation. To examine this, we determined the neuromuscular effects of BDNF on basal IAS smooth muscle tone and the smooth muscle cells (SMCs) and the effects of NANC nerve stimulation before and after high-affinity receptor tyrosine kinase receptor B (TrkB) antagonist K252a. We also investigated the mechanisms underlying BDNF-augmented increase in the IAS tone and NANC relaxation. We found that BDNF-increased IAS tone and SMC contractility were TTX resistant and attenuated by K252a. TrkB-specific agonist 7,8-dihydroxyflavone, similar to BDNF, also produced a concentration-dependent increase in the basal tone, whereas TrkB inhibitors K252a and ANA-12 produced a decrease in the tone. In addition, BDNF produced leftward shifts in the concentration-response curves with U46619 and ANG II (but not with bethanechol and K+ depolarization), and these shifts were reversed by K252a. Effects of Y27632 and Western blot data indicated that the BDNF-induced increase in IAS tone was mediated via RhoA/ROCK. BDNF-augmented NANC relaxation by electrical field stimulation was found to be mediated via the nitric oxide (NO)/soluble guanylate cyclase (sGC) pathway rather than via increased sensitivity to NO. In conclusion, the net effect of BDNF was that it caused an increase in the basal IAS tone via RhoA/ROCK signaling. BDNF also augmented NANC relaxation via NO/sGC. These findings may have relevance to the role of BDNF in the pathophysiology and therapeutic targeting of the IAS-associated rectoanal motility disorders.NEW & NOTEWORTHY These studies for the first time to our knowledge demonstrate that increased levels of brain-derived neurotrophic factor (BDNF; conceivably released from smooth muscle cells and/or the enteric neurons) has two major effects. First, BDNF augments the internal anal sphincter (IAS) tone via tyrosine kinase receptor B/thromboxane A2-receptor, angiotensin II receptor type 1/RhoA/ROCK signaling; and second, it increases nonadrenergic noncholinergic relaxation via nitric oxide/soluble guanylate cyclase. These studies may have relevance in therapeutic targeting in the anorectal motility disorders associated with the IAS.
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Affiliation(s)
- Arjun Singh
- 1Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Ipsita Mohanty
- 2Department of Pharmacology, Drexel University, Philadelphia, Pennsylvania
| | - Jagmohan Singh
- 3Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- 1Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
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11
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Yu Q, Gratzke C, Wang R, Li B, Kuppermann P, Herlemann A, Tamalunas A, Wang Y, Rutz B, Ciotkowska A, Wang X, Strittmatter F, Waidelich R, Stief CG, Hennenberg M. A NAV2729-sensitive mechanism promotes adrenergic smooth muscle contraction and growth of stromal cells in the human prostate. J Biol Chem 2019; 294:12231-12249. [PMID: 31243101 DOI: 10.1074/jbc.ra119.007958] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/19/2019] [Indexed: 12/25/2022] Open
Abstract
Voiding symptoms in benign prostatic hyperplasia (BPH) are driven by prostate smooth muscle contraction and prostate growth. Smooth muscle contraction in the prostate and other organs critically depends on activation of the small monomeric GTPase RhoA and probably Rac1. A role of another GTPase, ADP-ribosylation factor 6 (ARF6), for smooth muscle contraction has been recently suggested by indirect evidence but remains to be proven for any organ. Here, we report effects of NAV2729, an inhibitor with assumed specificity for ARF6, in human prostate tissues and cultured prostate stromal cells (WPMY-1). NAV2729 (5 μm) inhibited neurogenic and α1-adrenergic contractions of human prostate tissues. Contractions induced by endothelin-1, by the thromboxane A2 agonist U46619, or by high molar KCl were not inhibited. Correlation analyses suggested up-regulation of prostatic ARF6 expression with increasing degree of BPH, as ARF6 expression increased with the content of prostate-specific antigen (PSA) of prostate tissues. NAV2729 inhibited ARF6 activity but not other GTPases (ARF1, RhoA, Rac1) in prostate tissues and in WPMY-1 cells. Proliferation of WPMY-1 cells was inhibited concentration-dependently by NAV2726, as reflected by decreased viability, 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and expression of Ki-67. Silencing of ARF6 expression mimicked effects of NAV2729 on viability and in the EdU assay. Effects of NAV2729 on viability and proliferation were attenuated in cells with silenced ARF6 expression. Our findings suggest that a NAV2729-sensitive mechanism promotes adrenergic contraction and stromal cell growth in the human prostate, which is probably ARF6-mediated. Similar actions in other organs and urodynamic effects of NAV2729 appear possible.
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Affiliation(s)
- Qingfeng Yu
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany; Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510230, China
| | - Christian Gratzke
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany; Department of Urology, University of Freiburg, Freiburg 79106, Germany
| | - Ruixiao Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Bingsheng Li
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Paul Kuppermann
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Annika Herlemann
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Alexander Tamalunas
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Yiming Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Beata Rutz
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Anna Ciotkowska
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Xiaolong Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Frank Strittmatter
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Raphaela Waidelich
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Christian G Stief
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Martin Hennenberg
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany.
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12
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Mohanty I, Singh J, Rattan S. Downregulation of thromboxane A2 and angiotensin II type 1 receptors associated with aging-related decrease in internal anal sphincter tone. Sci Rep 2019; 9:6759. [PMID: 31043680 PMCID: PMC6494869 DOI: 10.1038/s41598-019-42894-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 04/10/2019] [Indexed: 12/19/2022] Open
Abstract
Aging-associated decrease in internal anal sphincter (IAS) tone (AADI) is a major contributor in the rectoanal incontinence (RI). To determine the pathogenesis of AADI, we investigated the effect of aging on GPCR activation and related downstream signaling. We particularly investigated two GPCRs that characterize IAS smooth muscle cells (SMCs): thromboxane A2 and angiotensin II type 1. Two groups of Fischer 344 rats (6-month-old [young group] and 26-month-old [old group]) were employed to determine the GPCR function by isometric contraction, the expressions of GPCRs, and their downstream regulatory signaling proteins (regulator of G-protein signaling 2, RGS2; GPCR Kinase 5, GRK5; and β-arrestin, Arrb2) using RT-PCR, qPCR, and western blot analyses. We used reversible biotinylation to monitor the GPCR trafficking using SMCs. Aging selectively attenuated thromboxane A2 and Ang II-induced IAS contraction. RT-PCR, qPCR, and WB data revealed a significant decrease in the expressions of the GPCRs and increase in the expression of RGS2, GRK5, and Arrb2. The increased GPCR internalization and decreased recycling under aging were validated by reversible biotinylation. We conclude that downregulation of GPCR, accompanied by upregulation of regulatory proteins, plays an important role in receptor desensitization and may be important underlying mechanisms of RI in certain aging patients.
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Affiliation(s)
- Ipsita Mohanty
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, 1025 Walnut St., Room #320 College, Philadelphia, Pennsylvania, 19107, USA
| | - Jagmohan Singh
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, 1025 Walnut St., Room #320 College, Philadelphia, Pennsylvania, 19107, USA
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, 1025 Walnut St., Room #320 College, Philadelphia, Pennsylvania, 19107, USA.
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13
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Xie Y, Perrino BA. Quantitative in situ proximity ligation assays examining protein interactions and phosphorylation during smooth muscle contractions. Anal Biochem 2019; 577:1-13. [PMID: 30981700 DOI: 10.1016/j.ab.2019.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/21/2019] [Accepted: 04/10/2019] [Indexed: 12/26/2022]
Abstract
Antibody-based in situ proximity ligation assays (isPLA) have the potential to study protein phosphorylation and protein interactions with spatial resolution in intact tissues. However, the application of isPLA at the tissue level is limited by a lack of appropriate positive and negative controls and the difficulty in accounting for changes in tissue shape. Here we demonstrate a set of experimental and computational approaches using gastric fundus smooth muscles to improve the validity of quantitative isPLA. Appropriate positive and negative biological controls and PLA technical controls were selected to ensure experimental rigor. To account for changes in morphology between relaxed and contracted smooth muscles, target PLA spots were normalized to smooth muscle myosin light chain 20 PLA spots or the cellular cross-sectional areas. We describe the computational steps necessary to filter out false-positive improperly sized spots and set the thresholds for counting true positive PLA spots to quantify the PLA signals. We tested our approach by examining protein phosphorylation and protein interactions in smooth muscle myofilament Ca2+ sensitization pathways from resting and contracted gastric fundus smooth muscles. In conclusion, our tissue-level isPLA method enables unbiased quantitation of protein phosphorylation and protein-protein interactions in intact smooth muscle tissues, suggesting the potential for quantitative isPLA applications in other types of intact tissues.
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Affiliation(s)
- Yeming Xie
- Department of Physiology and Cell Biology, University of Nevada Reno, School of Medicine, MS 0352, 1664 N Virginia St, Reno, NV, 89557, USA
| | - Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada Reno, School of Medicine, MS 0352, 1664 N Virginia St, Reno, NV, 89557, USA.
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14
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Steel N, Faniyi AA, Rahman S, Swietlik S, Czajkowska BI, Chan BT, Hardgrave A, Steel A, Sparwasser TD, Assas MB, Grencis RK, Travis MA, Worthington JJ. TGFβ-activation by dendritic cells drives Th17 induction and intestinal contractility and augments the expulsion of the parasite Trichinella spiralis in mice. PLoS Pathog 2019; 15:e1007657. [PMID: 30998782 PMCID: PMC6472816 DOI: 10.1371/journal.ppat.1007657] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 02/25/2019] [Indexed: 12/17/2022] Open
Abstract
Helminths are highly prevalent metazoan parasites that infect over a billion of the world's population. Hosts have evolved numerous mechanisms to drive the expulsion of these parasites via Th2-driven immunity, but these responses must be tightly controlled to prevent equally devastating immunopathology. However, mechanisms that regulate this balance are still unclear. Here we show that the vigorous Th2 immune response driven by the small intestinal helminth Trichinella spiralis, is associated with increased TGFβ signalling responses in CD4+ T-cells. Mechanistically, enhanced TGFβ signalling in CD4+ T-cells is dependent on dendritic cell-mediated TGFβ activation which requires expression of the integrin αvβ8. Importantly, mice lacking integrin αvβ8 on DCs had a delayed ability to expel a T. spiralis infection, indicating an important functional role for integrin αvβ8-mediated TGFβ activation in promoting parasite expulsion. In addition to maintaining regulatory T-cell responses, the CD4+ T-cell signalling of this pleiotropic cytokine induces a Th17 response which is crucial in promoting the intestinal muscle hypercontractility that drives worm expulsion. Collectively, these results provide novel insights into intestinal helminth expulsion beyond that of classical Th2 driven immunity, and highlight the importance of IL-17 in intestinal contraction which may aid therapeutics to numerous diseases of the intestine.
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Affiliation(s)
- Nicola Steel
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Aduragbemi A. Faniyi
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Sayema Rahman
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Stefanie Swietlik
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Beata I. Czajkowska
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Bethany T. Chan
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Alexander Hardgrave
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Anthony Steel
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Tim D. Sparwasser
- Institute of Infection Immunology, TWINCORE, Center for Experimental and Clinical Infection Research, Hannover, Germany
| | - Mushref B. Assas
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Faculty of Applied Medical Sciences, King AbdulAziz University, Jeddah, Saudi Arabia
| | - Richard K. Grencis
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom
| | - Mark A. Travis
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, United Kingdom
| | - John J. Worthington
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
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15
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Ferreira CHF, Shifrin Y, Pan J, Ivanovska J, McNamara PJ, Belik J. The newborn rat gastric emptying rate is volume and not developmentally dependent. Neurogastroenterol Motil 2018; 30:e13233. [PMID: 29024213 DOI: 10.1111/nmo.13233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Gastric residuals are a common finding in enterally fed preterm neonates and traditionally thought to reflect immaturity-related delayed gastric emptying. Adult human data suggest that the meal volume regulate the gastric emptying rate, but early in life, this has not been adequately evaluated. The goal of this study was to study the rat postnatal changes in gastric emptying rate and the strain-induced effect on muscle contraction. We hypothesized that the stomach content volume and not developmental factors determines the newborn gastric emptying rate, via the Rho-kinase 2 (ROCK-2) pathway. METHODS Gastric volume and emptying rate measurements were obtained by ultrasound at different postprandial times and the wall strain-dependent changes in muscle contraction were evaluated ex vivo. KEY RESULTS The newborn rat gastric emptying rate was unrelated to postnatal age, maximal 30 min postprandial, and directly proportional to content volume. In vitro measurements showed that the agonist-induced gastric muscle contraction was directly proportional to the stomach wall strain. These changes were mediated via upregulation of ROCK-2 activity. CONCLUSIONS & INFERENCES The newborn rat gastric emptying rate is not developmentally regulated, but dependent on the content volume via wall strain-induced ROCK-2 activation. Further clinical studies addressing the content volume effect on the rate of gastric emptying are warranted, to enhance feeding tolerance in preterm neonates.
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Affiliation(s)
- C H F Ferreira
- Hospital das Clinicas, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Y Shifrin
- Departments of Paediatrics and Physiology, Translational Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - J Pan
- Departments of Paediatrics and Physiology, Translational Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - J Ivanovska
- Departments of Paediatrics and Physiology, Translational Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - P J McNamara
- Departments of Paediatrics and Physiology, Translational Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - J Belik
- Departments of Paediatrics and Physiology, Translational Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
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16
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Singh J, Mohanty I, Addya S, Phillips B, Mee Yong H, An SS, Penn RB, Rattan S. Role of differentially expressed microRNA-139-5p in the regulation of phenotypic internal anal sphincter smooth muscle tone. Sci Rep 2017; 7:1477. [PMID: 28469189 PMCID: PMC5431208 DOI: 10.1038/s41598-017-01550-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/27/2017] [Indexed: 12/19/2022] Open
Abstract
The present study focused on the role of microRNA-139-5p (miRNA-139-5p) in the regulation of basal tone in internal anal sphincter (IAS). Applying genome-wide miRNA microarrays on the phenotypically distinct smooth muscle cells (SMCs) within the rat anorectrum, we identified miRNA-139-5p as differentially expressed RNA repressor with highest expression in the purely phasic smooth muscle of anococcygeus (ASM) vs. the truly tonic smooth muscle of IAS. This pattern of miRNA-139-5p expression, previously shown to target ROCK2, was validated by target prediction using ingenuity pathway (IPA) and by qPCR analyses. Immunoblotting, immunocytochemistry (ICC), and functional assays using IAS tissues and cells subjected to overexpression/knockdown of miRNA-139-5p confirmed the inverse relationship between miRNA-139-5p and ROCK2 expressions/IAS tone. Overexpression of miRNA-139-5p caused a decrease, while knockdown by anti-miRNA-139-5p caused an increase in the IAS tone; these tissue contractile responses were confirmed by single-cell contraction using magnetic twisting cytometry (MTC). These findings suggest miRNA-139-5p is capable of significantly influencing the phenotypic tonicity in smooth muscle via ROCK2: a lack of tone in ASM may be associated with the suppression of ROCK2 by high expression of miRNA-139-5p, whereas basal IAS tone may be associated with the persistence of ROCK2 due to low expression of miRNA-139-5p.
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Affiliation(s)
- Jagmohan Singh
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Ipsita Mohanty
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Sankar Addya
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Benjamin Phillips
- Department of Surgery, Division of Colorectal Surgery, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hwan Mee Yong
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Steven S An
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Raymond B Penn
- Center for Translational Medicine (RP), Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA.
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17
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Rattan S. Ca2+/calmodulin/MLCK pathway initiates, and RhoA/ROCK maintains, the internal anal sphincter smooth muscle tone. Am J Physiol Gastrointest Liver Physiol 2017; 312:G63-G66. [PMID: 27932502 PMCID: PMC5283903 DOI: 10.1152/ajpgi.00370.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/28/2016] [Accepted: 12/02/2016] [Indexed: 02/07/2023]
Affiliation(s)
- Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
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18
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Singh J, Boopathi E, Addya S, Phillips B, Rigoutsos I, Penn RB, Rattan S. Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a. Am J Physiol Gastrointest Liver Physiol 2016; 311:G964-G973. [PMID: 27634012 PMCID: PMC5130548 DOI: 10.1152/ajpgi.00290.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/13/2016] [Indexed: 01/31/2023]
Abstract
A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets (Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A2 analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.
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Affiliation(s)
- Jagmohan Singh
- 1Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
| | - Ettickan Boopathi
- 2Center for Translational Medicine, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
| | - Sankar Addya
- 3Kimmel Cancer Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
| | - Benjamin Phillips
- 4Department of Surgery, Division of Colorectal Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Isidore Rigoutsos
- 5Computational Medicine Center, Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Raymond B. Penn
- 2Center for Translational Medicine, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
| | - Satish Rattan
- 1Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
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19
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Sobchak C, Fajardo AF, Shifrin Y, Pan J, Belik J. Gastric and pyloric sphincter muscle function and the developmental-dependent regulation of gastric content emptying in the rat. Am J Physiol Gastrointest Liver Physiol 2016; 310:G1169-75. [PMID: 27125274 DOI: 10.1152/ajpgi.00046.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/23/2016] [Indexed: 01/31/2023]
Abstract
Feeding intolerance is a common issue in the care of preterm neonates. The condition manifests as delayed emptying of gastric contents and represents a therapeutic challenge, since the factors accounting for its manifestations are unknown. The main goal of this study was to comparatively investigate the age-related function of rat gastric and pyloric smooth muscle and their putative regulators. We hypothesized that a reduced gastric muscle contraction potential early in life contributes to the delayed gastric emptying of the newborn. Newborn and adult rat gastric (fundus) and pyloric sphincter tissues were comparatively studied in vitro. Shortening of the tissue-specific dissociated smooth muscle cell was evaluated, and expression of the key regulatory proteins Rho-associated kinase 2 and myosin light chain kinase was determined. Gastric and pyloric smooth muscle cell shortening was significantly greater in the adult than the respective newborn counterpart. Expression of myosin light chain kinase and Rho-associated kinase 2 was developmentally regulated and increased with age. Pyloric sphincter muscle expresses a higher neuronal nitric oxide synthase and phosphorylated vasodilator-stimulated phosphoprotein content in newborn than adult tissue. Compared with later in life, the newborn rat gastropyloric muscle has a Ca(2+)-related reduced potential for contraction and the pyloric sphincter relaxation-dependent modulators are overexpressed. To the extent that these rodent data can be extrapolated to humans, the delayed gastric emptying in the newborn reflects reduced stomach muscle contraction potential, as opposed to increased pyloric sphincter tone.
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Affiliation(s)
- Curtis Sobchak
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; and
| | - A Felipe Fajardo
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; and
| | - Yulia Shifrin
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; and
| | - Jingyi Pan
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; and
| | - Jaques Belik
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; and Department of Paediatrics and Physiology, University of Toronto, Toronto, Ontario, Canada
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20
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Krishna CV, Singh J, Thangavel C, Rattan S. Role of microRNAs in gastrointestinal smooth muscle fibrosis and dysfunction: novel molecular perspectives on the pathophysiology and therapeutic targeting. Am J Physiol Gastrointest Liver Physiol 2016; 310:G449-59. [PMID: 26822916 PMCID: PMC4824177 DOI: 10.1152/ajpgi.00445.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/20/2016] [Indexed: 01/31/2023]
Abstract
MicroRNAs (miRNAs) belong to a group of short noncoding RNA molecules with important roles in cellular biology. miRNAs regulate gene expression by repressing translation or degrading the target mRNA. Recently, a growing body of evidence suggests that miRNAs are implicated in many diseases and could be potential biomarkers. Fibrosis and/smooth muscle (SM) dysfunction contributes to the morbidity and mortality associated with several diseases of the gastrointestinal tract (GIT). Currently available therapeutic modalities are unsuccessful in efficiently blocking or reversing fibrosis and/or SM dysfunction. Recent understanding of the role of miRNAs in signaling pathway of fibrogenesis and SM phenotype switch has provided a new insight into translational research. However, much is still unknown about the molecular targets and therapeutic potential of miRNAs in the GIT. This review discusses miRNA biology, pathophysiology of fibrosis, and aging- associated SM dysfunction in relation to the deregulation of miRNAs in the GIT. We also highlight the role of selected miRNAs associated with fibrosis and SM dysfunction-related diseases of the GIT.
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Affiliation(s)
| | - Jagmohan Singh
- 2Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Chellappagounder Thangavel
- 3Department of Radiation Oncology, Sidney Kimmel Cancer Center (TC), Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- 2Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania; and
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21
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Singh J, Kumar S, Rattan S. Bimodal effect of oxidative stress in internal anal sphincter smooth muscle. Am J Physiol Gastrointest Liver Physiol 2015; 309:G292-300. [PMID: 26138467 PMCID: PMC4556951 DOI: 10.1152/ajpgi.00125.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/29/2015] [Indexed: 01/31/2023]
Abstract
Changes in oxidative stress may affect basal tone and relaxation of the internal anal sphincter (IAS) smooth muscle in aging. We examined this issue by investigating the effects of the oxidative stress inducer 6-anilino-5,8-quinolinedione (LY-83583) in basal as well as U-46619-stimulated tone, and nonadrenergic, noncholinergic (NANC) relaxation in rat IAS. LY-83583, which works via generation of reactive oxygen species in living cells, produced a bimodal effect in IAS tone: lower concentrations (0.1 nM to 10 μM) produced a concentration-dependent increase, while higher concentrations (50-100 μM) produced a decrease in IAS tone. An increase in IAS tone by lower concentrations was associated with an increase in RhoA/Rho kinase (ROCK) activity. This was evident by the increase in RhoA/ROCK in the particulate fractions, in ROCK activity, and in the levels of phosphorylated (p) (Thr696)-myosin phosphatase target subunit 1 and p(Thr18/Ser19)-20-kDa myosin light chain. Conversely, higher concentrations of LY-83583 produced inhibitory effects on RhoA/ROCK. Interestingly, both the excitatory and inhibitory effects of LY-83583 in the IAS were reversed by superoxide dismutase. The excitatory effects of LY-83583 were found to resemble those with neuronal nitric oxide synthase (nNOS) inhibition by l-NNA, since it produced a significant increase in the IAS tone and attenuated NANC relaxation. These effects of LY-83583 and l-NNA were reversible by l-arginine. This suggests the role of nNOS inhibition and RhoA/ROCK activation in the increase in IAS tone by LY-83583. These data have important implications in the pathophysiology and therapeutic targeting of rectoanal disorders, especially associated with IAS dysfunction.
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Affiliation(s)
- Jagmohan Singh
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sumit Kumar
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
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22
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Rattan S, Singh J, Kumar S, Phillips B. Nature of extracellular signal that triggers RhoA/ROCK activation for the basal internal anal sphincter tone in humans. Am J Physiol Gastrointest Liver Physiol 2015; 308:G924-33. [PMID: 25882611 PMCID: PMC4451323 DOI: 10.1152/ajpgi.00017.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The extracellular signal that triggers activation of rho-associated kinase (RhoA/ROCK), the major molecular determinant of basal internal anal sphincter (IAS) smooth muscle tone, is not known. Using human IAS tissues, we identified the presence of the biosynthetic machineries for angiotensin II (ANG II), thromboxane A2 (TXA2), and prostaglandin F2α (PGF2α). These end products of the renin-angiotensin system (RAS) (ANG II) and arachidonic acid (TXA2 and PGF2α) pathways and their effects in human IAS vs. rectal smooth muscle (RSM) were studied. A multipronged approach utilizing immunocytochemistry, Western blot analyses, and force measurements was implemented. Additionally, in a systematic analysis of the effects of respective inhibitors along different steps of biosynthesis and those of antagonists, their end products were evaluated either individually or in combination. To further describe the molecular mechanism for the IAS tone via these pathways, we monitored RhoA/ROCK activation and its signal transduction cascade. Data showed characteristically higher expression of biosynthetic machineries of RAS and AA pathways in the IAS compared with the RSM. Additionally, specific inhibition of the arachidonic acid (AA) pathway caused ~80% decrease in the IAS tone, whereas that of RAS lead to ~20% decrease. Signal transduction studies revealed that the end products of both AA and RAS pathways cause increase in the IAS tone via activation of RhoA/ROCK. Both AA and RAS (via the release of their end products TXA2, PGF2α, and ANG II, respectively), provide extracellular signals which activate RhoA/ROCK for the maintenance of the basal tone in human IAS.
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Affiliation(s)
- Satish Rattan
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Jagmohan Singh
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Sumit Kumar
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Benjamin Phillips
- 2Department of Surgery, Division of Colorectal Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
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Welsh C, Shifrin Y, Pan J, Belik J. Infantile hypertrophic pyloric stenosis (IHPS): a study of its pathophysiology utilizing the newborn hph-1 mouse model of the disease. Am J Physiol Gastrointest Liver Physiol 2014; 307:G1198-206. [PMID: 25359537 DOI: 10.1152/ajpgi.00221.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Infantile hypertrophic pyloric stenosis (IHPS) is a common disease of unknown etiology. The tetrahydrobiopterin (BH4)-deficient hyperphenylalaninemia-1 (hph-1) newborn mouse has a similar phenotype to the human condition. For hph-1 and wild-type control animals, pyloric tissue agonist-induced contractile properties, reactive oxygen species (ROS) generation, cGMP, neuronal nitric oxide synthase (nNOS) content, and Rho-associated protein kinase 2 (ROCK-2) expression and activity were evaluated. Primary pyloric smooth muscle cells from wild-type newborn animals were utilized to evaluate the effect of BH4 deficiency. One-week-old hph-1 mice exhibited a fourfold increase (P < 0.01) in the pyloric sphincter muscle contraction magnitude but similar relaxation values when compared with wild-type animals. The pyloric tissue nNOS expression and cGMP content were decreased, whereas the rate of nNOS uncoupling increased (P < 0.01) in 1-wk-old hph-1 mice when compared with wild-type animals. These changes were associated with increased pyloric tissue ROS generation and elevated ROCK-2 expression/activity (P < 0.05). At 1-3 days of age and during adulthood, the gastric emptying rate of the hph-1 mice was not altered, and there were no genotype differences in pyloric tissue ROS generation, nNOS expression, or ROCK-2 activity. BH4 inhibition in pyloric smooth muscle cells resulted in increased ROS generation (P < 0.01) and ROCK-2 activity (P < 0.05). Oxidative stress upregulated ROCK-2 activity in pyloric tissue, but no changes were observed in newborn fundal tissue in vitro. We conclude that ROS-induced upregulation of ROCK-2 expression accounts for the increased pyloric sphincter tone and nNOS downregulation in the newborn hph-1 mice. The role of ROCK-2 activation in the pathogenesis of IHPS warrants further study.
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Affiliation(s)
- Christopher Welsh
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Yulia Shifrin
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Jingyi Pan
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Jaques Belik
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics and Physiology, University of Toronto, Toronto, Ontario, Canada
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Singh J, Kumar S, Krishna CV, Rattan S. Aging-associated oxidative stress leads to decrease in IAS tone via RhoA/ROCK downregulation. Am J Physiol Gastrointest Liver Physiol 2014; 306:G983-91. [PMID: 24742984 PMCID: PMC4042111 DOI: 10.1152/ajpgi.00087.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Internal anal sphincter (IAS) tone plays an important role in rectoanal incontinence (RI). IAS tone may be compromised during aging, leading to RI in certain patients. We examined the influence of oxidative stress in the aging-associated decrease in IAS tone (AADI). Using adult (4-6 mo old) and aging (24-30 mo old) rats, we determined the effect of oxidative stress on IAS tone and the regulatory RhoA/ROCK signal transduction cascade. We determined the effect of the oxidative stress inducer LY83583, which produces superoxide anions (O2 (·-)), on basal and stimulated IAS tone before and after treatment of intact smooth muscle strips and smooth muscle cells with the O2 (·-) scavenger SOD. Our data showed that AADI was associated with a decrease in RhoA/ROCK expression at the transcriptional and translational levels. Oxidative stress with a LY83583-mediated decrease in IAS tone and relaxation of IAS smooth muscle cells was associated with a decrease in RhoA/ROCK signal transduction, which was reversible by SOD. In addition, LY83583 caused a significant decrease in IAS contraction produced by the RhoA activator and a known RhoA/ROCK agonist, U46619, that was also reversible by SOD. The inhibitory effects of LY83583 and the ROCK inhibitor Y27632 on the U46619-induced increase in IAS tone were similar. We conclude that an increase in oxidative stress plays an important role in AADI in the elderly and may be one of the underlying mechanisms of RI in certain aging patients.
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Affiliation(s)
| | | | | | - Satish Rattan
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Rattan S. Smooth muscle-specific myosin phosphatase target subunit 1 (MYPT1): an important piece of the puzzle. Gastroenterology 2013; 145:1494-5. [PMID: 24172015 PMCID: PMC3888222 DOI: 10.1053/j.gastro.2013.07.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/25/2013] [Indexed: 01/22/2023]
Affiliation(s)
- Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Lentle RG, Reynolds GW, Janssen PWM. Gastrointestinal tone; its genesis and contribution to the physical processes of digestion. Neurogastroenterol Motil 2013; 25:931-42. [PMID: 24028606 DOI: 10.1111/nmo.12223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/08/2013] [Indexed: 12/24/2022]
Abstract
BACKGROUND Myogenic tone has long been recognised as an important component of gastrointestinal motility. Recent work has clarified the cellular mechanisms that engender tone and the neurogenic and mechanical stimuli that modulate it but has also highlighted cellular and regional specialisation in these mechanisms within the GI tract. Smooth muscle in all segments of the gut has the capability of latching, i.e. can generate ongoing specific rather than tetanic tone. This is likely modulated by both direct and indirect input from agonists such as acetylcholine and mechanoreceptors, the latter originating in ICC-IM, smooth muscle cells or elements of the ENS. Tonic contraction can occur in the absence of phasic contractions or concurrent with them, and it can modulate wall compliance and the capacity of particular segments, thereby affecting the level of on-flow and mixing, both luminal and adjacent to the mucosa. PURPOSE The review seeks to provide an overview of our understanding of the mechanism by which tone is generated and maintained, highlighting its modulation by neurogenic and mechanical stimuli, its mechanical consequences in the walls of the various segments of the gastrointestinal tract and its contribution to flow and mixing of contained digesta.
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Affiliation(s)
- R G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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Zhang Y, Hermanson ME, Eddinger TJ. Tonic and phasic smooth muscle contraction is not regulated by the PKCα - CPI-17 pathway in swine stomach antrum and fundus. PLoS One 2013; 8:e74608. [PMID: 24058600 PMCID: PMC3776813 DOI: 10.1371/journal.pone.0074608] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 08/04/2013] [Indexed: 01/31/2023] Open
Abstract
Regulation of myosin light chain phosphatase (MLCP) via protein kinase C (PKC) and the 17 kDa PKC-potentiated inhibitor of myosin light chain phosphatase (CPI-17) has been reported as a Ca2+ sensitization signaling pathway in smooth muscle (SM), and thus may be involved in tonic vs. phasic contractions. This study examined the protein expression and spatial-temporal distribution of PKCα and CPI-17 in intact SM tissues. KCl or carbachol (CCh) stimulation of tonic stomach fundus SM generates a sustained contraction while the phasic stomach antrum generates a transient contraction. In addition, the tonic fundus generates greater relative force than phasic antrum with 1 µM phorbol 12, 13-dibutyrate (PDBu) stimulation which is reported to activate the PKCα – CPI-17 pathway. Western blot analyses demonstrated that this contractile difference was not caused by a difference in the protein expression of PKCα or CPI-17 between these two tissues. Immunohistochemical results show that the distribution of PKCα in the longitudinal and circular layers of the fundus and antrum do not differ, being predominantly localized near the SM cell plasma membrane. Stimulation of either tissue with 1 µM PDBu or 1 µM CCh does not alter this peripheral PKCα distribution. There are no differences between these two tissues for the CPI-17 distribution, but unlike the PKCα distribution, CPI-17 appears to be diffusely distributed throughout the cytoplasm under relaxed tissue conditions but shifts to a primarily peripheral distribution at the plasma membrane with stimulation of the tissues with 1 µM PDBu or 1 µM CCh. Results from double labeling show that neither PKCα nor CPI-17 co-localize at the adherens junction (vinculin/talin) at the membrane but they do co-localize with each other and with caveoli (caveolin) at the membrane. This lack of difference suggests that the PKCα - CPI-17 pathway is not responsible for the tonic vs. phasic contractions observed in stomach fundus and antrum.
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Affiliation(s)
- Yu Zhang
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America
| | - Meghan E. Hermanson
- Department of Biology, Bradley University, Peoria, Illinois, United States of America
| | - Thomas J. Eddinger
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Gozen A, Demiryurek S, Taskin A, Ciralik H, Bilinc H, Kara S, Aydin A, Aksoy N, Ceylan H. Protective activity of ischemic preconditioning on rat testicular ischemia: effects of Y-27632 and 5-hydroxydecanoic acid. J Pediatr Surg 2013; 48:1565-72. [PMID: 23895973 DOI: 10.1016/j.jpedsurg.2012.10.074] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 09/30/2012] [Accepted: 10/19/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND/PURPOSE The aim of this study was to investigate the role of ischemic preconditioning (IPC) on ischemia/reperfusion (I/R)-induced injury of rat testis and determine the effects of 5-hydroxydecanoic acid (5-HD), a selective K(ATP) channel antagonist, and Y-27632, a selective Rho kinase inhibitor, on IPC. METHODS I/R injury was induced by 180 min ischemia and 60 min reperfusion of testis. There were 5 groups. Group 1 served as untreated controls. The rats in Group 2 were subjected to I/R only. In Group 3, 3 cycles of IPC (5 min transient ischemia plus 5 min reperfusion) were performed prior to I/R. In groups 4 and 5, the rats were treated as in Group 3 but received intraperitoneal injections of 0.3 mg/kg Y-27632 or 10 mg/kg 5-HD prior to IPC, respectively. RESULTS I/R led to severe histopathological lesions in the rat testis and significantly lowered the scoring. I/R resulted in significant elevation in tissue lipid peroxide levels, myeloperoxidase (MPO) activity, and total antioxidative capacity (TAC), total oxidative status, and oxidative stress index levels. Protective effects of IPC on I/R-induced testicular injury of rats were observed with the significant recovery in these biochemical parameters. Y-27632 treatment led to a significant decrease in MPO activity, but there were no significant changes in the remaining parameters. Effects of IPC were blocked by 5-HD except in the TAC levels. CONCLUSION Our results showed that IPC protected rat testis against I/R-induced injury via activation of KATP channels. Additionally, Rho kinase inhibition preserved the effects of IPC in testis.
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Affiliation(s)
- Ahmet Gozen
- Department of Pediatric Surgery, Faculty of Medicine, University of Gaziantep, Gaziantep, 27310, Turkey
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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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Bhetwal BP, An C, Baker SA, Lyon KL, Perrino BA. Impaired contractile responses and altered expression and phosphorylation of Ca(2+) sensitization proteins in gastric antrum smooth muscles from ob/ob mice. J Muscle Res Cell Motil 2013; 34:137-49. [PMID: 23576331 DOI: 10.1007/s10974-013-9341-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/27/2013] [Indexed: 12/21/2022]
Abstract
Diabetic gastroparesis is a common complication of diabetes, adversely affecting quality of life with symptoms of abdominal discomfort, nausea, and vomiting. The pathogenesis of this complex disorder is not well understood, involving abnormalities in the extrinsic and enteric nervous systems, interstitial cells of Cajal (ICCs), smooth muscles and immune cells. The ob/ob mouse model of obesity and diabetes develops delayed gastric emptying, providing an animal model for investigating how gastric smooth muscle dysfunction contributes to the pathophysiology of diabetic gastroparesis. Although ROCK2, MYPT1, and CPI-17 activities are reduced in intestinal motility disorders, their functioning has not been investigated in diabetic gastroparesis. We hypothesized that reduced expression and phosphorylation of the myosin light chain phosphatase (MLCP) inhibitory proteins MYPT1 and CPI-17 in ob/ob gastric antrum smooth muscles could contribute to the impaired antrum smooth muscle function of diabetic gastroparesis. Spontaneous and carbachol- and high K(+)-evoked contractions of gastric antrum smooth muscles from 7 to 12 week old male ob/ob mice were reduced compared to age- and strain-matched controls. There were no differences in spontaneous and agonist-evoked intracellular Ca(2+) transients and myosin light chain kinase expression. The F-actin:G-actin ratios were similar. Rho kinase 2 (ROCK2) expression was decreased at both ages. Basal and agonist-evoked MYPT1 and myosin light chain 20 phosphorylation, but not CPI-17 phosphorylation, was reduced compared to age-matched controls. These findings suggest that reduced MLCP inhibition due to decreased ROCK2 phosphorylation of MYPT1 in gastric antrum smooth muscles contributes to the antral dysmotility of diabetic gastroparesis.
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Affiliation(s)
- Bhupal P Bhetwal
- Department of Physiology & Cell Biology, Center of Biomedical Research Excellence, University of Nevada School of Medicine, CMM 203E-MS 0575, 1664 N Virginia St, Reno, NV 89557, USA
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31
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Mattii L, Ippolito C, Segnani C, Battolla B, Colucci R, Dolfi A, Bassotti G, Blandizzi C, Bernardini N. Altered expression pattern of molecular factors involved in colonic smooth muscle functions: an immunohistochemical study in patients with diverticular disease. PLoS One 2013; 8:e57023. [PMID: 23437299 PMCID: PMC3577760 DOI: 10.1371/journal.pone.0057023] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 01/16/2013] [Indexed: 12/14/2022] Open
Abstract
Background The pathogenesis of diverticular disease (DD) is thought to result from complex interactions among dietary habits, genetic factors and coexistence of other bowel abnormalities. These conditions lead to alterations in colonic pressure and motility, facilitating the formation of diverticula. Although electrophysiological studies on smooth muscle cells (SMCs) have investigated colonic motor dysfunctions, scarce attention has been paid to their molecular abnormalities, and data on SMCs in DD are lacking. Accordingly, the main purpose of this study was to evaluate the expression patterns of molecular factors involved in the contractile functions of SMCs in the tunica muscularis of colonic specimens from patients with DD. Methods and Findings By means of immunohistochemistry and image analysis, we examined the expression of Cx26 and Cx43, which are prominent components of gap junctions in human colonic SMCs, as well as pS368-Cx43, PKCps, RhoA and αSMA, all known to regulate the functions of gap junctions and the contractile activity of SMCs. The immunohistochemical analysis revealed significant abnormalities in DD samples, concerning both the expression and distribution patterns of most of the investigated molecular factors. Conclusion This study demonstrates, for the first time, that an altered pattern of factors involved in SMC contractility is present at level of the tunica muscularis of DD patients. Moreover, considering that our analysis was conducted on colonic tissues not directly affected by diverticular lesions or inflammatory reactions, it is conceivable that these molecular alterations may precede and predispose to the formation of diverticula, rather than being mere consequences of the disease.
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Affiliation(s)
- Letizia Mattii
- Unit of Histology and Medical Embriology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
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Singh J, Rattan S. Bioengineered human IAS reconstructs with functional and molecular properties similar to intact IAS. Am J Physiol Gastrointest Liver Physiol 2012; 303:G713-22. [PMID: 22790596 PMCID: PMC3468534 DOI: 10.1152/ajpgi.00112.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Because of its critical importance in rectoanal incontinence, we determined the feasibility to reconstruct internal anal sphincter (IAS) from human IAS smooth muscle cells (SMCs) with functional and molecular attributes similar to the intact sphincter. The reconstructs were developed using SMCs from the circular smooth muscle layer of the human IAS, grown in smooth muscle differentiation media under sterile conditions in Sylgard-coated tissue culture plates with central Sylgard posts. The basal tone in the reconstructs and its changes were recorded following 0 Ca(2+), KCl, bethanechol, isoproterenol, protein kinase C (PKC) activator phorbol 12,13-dibutyrate, and Rho kinase (ROCK) and PKC inhibitors Y-27632 and Gö-6850, respectively. Western blot (WB), immunofluorescence (IF), and immunocytochemical (IC) analyses were also performed. The reconstructs developed spontaneous tone (0.68 ± 0.26 mN). Bethanechol (a muscarinic agonist) and K(+) depolarization produced contraction, whereas isoproterenol (β-adrenoceptor agonist) and Y-27632 produced a concentration-dependent decrease in the tone. Maximal decrease in basal tone with Y-27632 and Gö-6850 (each 10(-5) M) was 80.45 ± 3.29 and 17.76 ± 3.50%, respectively. WB data with the IAS constructs' SMCs revealed higher levels of RhoA/ROCK, protein kinase C-potentiated inhibitor or inhibitory phosphoprotein for myosin phosphatase (CPI-17), phospho-CPI-17, MYPT1, and 20-kDa myosin light chain vs. rectal smooth muscle. WB, IF, and IC studies of original SMCs and redispersed from the reconstructs for the relative distribution of different signal transduction proteins confirmed the feasibility of reconstruction of IAS with functional properties similar to intact IAS and demonstrated the development of myogenic tone with critical dependence on RhoA/ROCK. We conclude that it is feasible to bioengineer IAS constructs using human IAS SMCs that behave like intact IAS.
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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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Rattan S, Singh J. RhoA/ROCK pathway is the major molecular determinant of basal tone in intact human internal anal sphincter. Am J Physiol Gastrointest Liver Physiol 2012; 302:G664-75. [PMID: 22241857 PMCID: PMC3330775 DOI: 10.1152/ajpgi.00430.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The knowledge of molecular control mechanisms underlying the basal tone in the intact human internal anal sphincter (IAS) is critical for the pathophysiology and rational therapy for a number of debilitating rectoanal motility disorders. We determined the role of RhoA/ROCK and PKC pathways by comparing the effects of ROCK- and PKC-selective inhibitors Y 27632 and Gö 6850 (10(-8) to 10(-4) M), respectively, on the basal tone in the IAS vs. the rectal smooth muscle (RSM). Western blot studies were performed to determine the levels of RhoA/ROCK II, PKC-α, MYPT1, CPI-17, and MLC(20) in the unphosphorylated and phosphorylated forms, in the IAS vs. RSM. Confocal microscopic studies validated the membrane distribution of ROCK II. Finally, to confirm a direct relationship, we examined the enzymatic activities and changes in the basal IAS tone and p-MYPT1, p-CPI-17, and p-MLC(20), before and after Y 27632 and Gö 6850. Data show higher levels of RhoA/ROCK II and related downstream signal transduction proteins in the IAS vs. RSM. In addition, data show a significant correlation between the active RhoA/ROCK levels, ROCK enzymatic activity, downstream proteins, and basal IAS tone, before and after ROCK inhibitor. From these data we conclude 1) RhoA/ROCK and downstream signaling are constitutively active in the IAS, and this pathway (in contrast with PKC) is the critical determinant of the basal tone in intact human IAS; and 2) RhoA and ROCK are potential therapeutic targets for a number of rectoanal motility disorders for which currently there is no satisfactory treatment.
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Affiliation(s)
- Satish Rattan
- Dept. of Medicine, Division of Gastroenterology & Hepatology, Philadelphia, PA 19107, USA.
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Protective Effects of Dexpanthenol and Y-27632 on Stricture Formation in a Rat Model of Caustic Esophageal Injury. J Surg Res 2011; 171:517-23. [DOI: 10.1016/j.jss.2010.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 04/17/2010] [Accepted: 05/04/2010] [Indexed: 11/19/2022]
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Bhetwal BP, An CL, Fisher SA, Perrino BA. Regulation of basal LC20 phosphorylation by MYPT1 and CPI-17 in murine gastric antrum, gastric fundus, and proximal colon smooth muscles. Neurogastroenterol Motil 2011; 23:e425-36. [PMID: 21883701 PMCID: PMC3173524 DOI: 10.1111/j.1365-2982.2011.01769.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) govern myosin light chain (LC20) phosphorylation and smooth muscle contraction. Rho kinase (ROK) inhibits MLCP, resulting in greater LC20 phosphorylation and force generation at a given [Ca(2+) ](i) . Here, we investigate the role of ROK in regulating LC20 phosphorylation and spontaneous contractions of gastric fundus, gastric antrum, and proximal colon smooth muscles. METHODS Protein and phosphorylation levels were determined by western blotting. The effects of Y27632, nicardipine, and GF109203X on phosphorylation levels and contraction were measured. KEY RESULTS γ-Actin expression is similar in all three smooth muscles. LC20 and pS19 are highest, but ROK1 and ROK2 are lowest, in antrum and proximal colon smooth muscles. LZ +/- myosin phosphatase targeting subunit 1 (MYPT1), CPI-17, and pT696, pT853, and pT38 are highest in fundus and proximal colon smooth muscles. Myosin phosphatase-rho interacting protein (M-RIP) expression is lowest in fundus, and highest in antrum and proximal colon smooth muscles. Y27632 reduced pT853 in each smooth muscle, but reduced pT696 only in fundus smooth muscles. Nicardipine had no effect on pT38 in each smooth muscle, while GF109203X reduced pT38 in proximal colon and fundus smooth muscles. Y27632 or nicardipine reduced pS19 in proximal colon and fundus smooth muscles. Y27632 or nicardipine inhibited antrum and proximal colon smooth muscle spontaneous contractions, but only Y27632 reduced fundus smooth muscle tone. Zero external Ca(2+) relaxed each smooth muscle and abolished LC20 phosphorylation. CONCLUSIONS & INFERENCES Organ-specific mechanisms involving the MLCP interacting proteins LZ +/- MYPT1, M-RIP, and CPI-17 are critical to regulating basal LC20 phosphorylation in gastrointestinal smooth muscles.
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Affiliation(s)
- Bhupal P. Bhetwal
- Department of Physiology & Cell Biology, Center of Biomedical Research Excellence, University of Nevada School of Medicine, Reno, NV, USA
| | - Chang Long An
- Department of Physiology & Cell Biology, Center of Biomedical Research Excellence, University of Nevada School of Medicine, Reno, NV, USA
| | - Steven A. Fisher
- Departments of Medicine (Cardiology), and Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Brian A. Perrino
- Department of Physiology & Cell Biology, Center of Biomedical Research Excellence, University of Nevada School of Medicine, Reno, NV, USA
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Balyemez G, Sivasli E, Ceylan H, Tutar E, Ekiz S, Tarakcioglu M, Demiryurek AT, Coskun MY. Protective effects of Y-27632 on hypoxia/reoxygenation-induced intestinal injury in newborn rats. J Pediatr Surg 2011; 46:1490-4. [PMID: 21843713 DOI: 10.1016/j.jpedsurg.2010.11.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 11/09/2010] [Indexed: 01/21/2023]
Abstract
BACKGROUND/PURPOSE Necrotizing enterocolitis (NEC) is a major cause of mortality in neonates and is associated with a disruption in the protective intestinal barrier. The precise cause of NEC is elusive. However, ischemia/reperfusion injury of the intestine has been considered a major contributing factor. We examined the role of Y-27632, a selective Rho-kinase inhibitor, on a hypoxia/reoxygenation (H/R)-induced intestinal injury of newborn rat pups. METHODS Hypoxia/reoxygenation was achieved by placing rat pups in an airtight chamber aerated with 95% N(2) + 5% CO(2) for 10 minutes followed by 10-minute 100% oxygen. Forty newborn rat pups were randomly allocated into 4 groups. Group 1 served as untreated controls. The pups in group 2 were subjected to H/R only. In groups 3 and 4, the rats were treated with intraperitoneal injection of 0.3 and 3 mg kg(-1) day(-1) of Y-27632 for 5 days following H/R, respectively. The pups were killed 6 days following the H/R injury. Intestine specimens were evaluated for histopathology and biochemical investigation. RESULTS The microscopic lesions in H/R rat pups were virtually the same as those seen in neonatal NEC, with severe destruction of villi and crypts. Hypoxia/reoxygenation resulted in significant elevation in malondialdehyde levels, but decreased tissue nitric oxide levels (P < .05). Protective effects of Y-27632 on H/R-induced intestinal injury of newborn rat pups were observed with a significant decrease in the intestinal injury score, suppression in malondialdehyde levels, and increase in nitric oxide levels (P < .05). CONCLUSIONS In this experimental study, Y-27632 significantly attenuated H/R-induced intestinal injury. These findings indicate that inhibition of Rho-kinase may offer a novel therapeutic approach in the treatment of NEC.
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Affiliation(s)
- Gül Balyemez
- Faculty of Medicine, Department of Pediatrics, University of Gaziantep, Gaziantep, Turkey
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Singh J, Maxwell PJ, Rattan S. Immunocytochemical evidence for PDBu-induced activation of RhoA/ROCK in human internal anal sphincter smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2011; 301:G317-25. [PMID: 21566015 PMCID: PMC3154599 DOI: 10.1152/ajpgi.00084.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Studies were performed to determine the unknown status of PKC and RhoA/ROCK in the phorbol 12,13-dibutyrate (PDBu)-stimulated state in the human internal anal sphincter (IAS) smooth muscle cells (SMCs). We determined the effects of PDBu (10(-7) M), the PKC activator, on PKCα and RhoA and ROCK II translocation in the human IAS SMCs. We used immunocytochemistry and fluorescence microcopy in the basal state, following PDBu, and before and after PKC inhibitor calphostin C (10(-6) M), cell-permeable RhoA inhibitor C3 exoenzyme (2.5 μg/ml), and ROCK inhibitor Y 27632 (10(-6) M). We also determined changes in the SMC lengths via computerized digital micrometry. In the basal state PKCα was distributed almost uniformly throughout the cell, whereas RhoA and ROCK II were located in the higher intensities toward the periphery. PDBu caused significant translocation of PKCα, RhoA, and ROCK II. PDBu-induced translocation of PKCα was attenuated by calphostin C and not by C3 exoenzyme and Y 27632. However, PDBu-induced translocation of RhoA was blocked by C3 exoenzyme, and that of ROCK II was attenuated by both C3 exoenzyme and Y 27632. Contraction of the human IAS SMCs caused by PDBu in parallel with RhoA/ROCK II translocation was attenuated by C3 exoenzyme and Y 27632 but not by calphostin C. In human IAS SMCs RhoA/ROCK compared with PKC are constitutively active, and contractility by PDBu is associated with RhoA/ROCK activation rather than PKC. The relative contribution of RhoA/ROCK vs. PKC in the pathophysiology and potential therapy for the IAS dysfunction remains to be determined.
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Affiliation(s)
- Jagmohan Singh
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Pinckney J. Maxwell
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
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Saito M, Ohmasa F, Shomori K, Dimitriadis F, Ohiwa H, Shimizu S, Tsounapi P, Kinoshita Y, Satoh K. Rhos and Rho kinases in the rat prostate: their possible functional roles and distributions. Mol Cell Biochem 2011; 358:207-13. [PMID: 21720764 DOI: 10.1007/s11010-011-0936-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 06/21/2011] [Indexed: 01/02/2023]
Abstract
As there is increasing evidence that Rho-Rho kinase (ROCK) pathway plays an important role in the proliferation and contraction in many tissues, we investigated the contractile role of a ROCK inhibitor, fasudil, and the distribution of RhoA, RhoB, RhoC, ROCK1, and ROCK2 in the rat prostate. Twelve-week-old Sprague-Dawley rat prostate was used in this study. Rat prostatic contractile responses induced by carbachol and norepinephrine were investigated in organ bath studies without or with 10(-7), 10(-6), and 10(-5) M of a non-selective ROCK inhibitor, fasudil. Immunoblot analysis and immunohistochemical staining were performed to investigate the participation levels of RhoA, RhoB, RhoC, ROCK1, and ROCK2. The E(max) values induced by carbachol and norepinephrine were similar in the rat prostate. Fasudil significantly inhibited carbachol- or norepinephrine-induced prostatic contractions in a dose-dependent manner. Fasudil 10(-5) M reduced the initial prostatic contraction (without fasudil) to 56.7 ± 5.9% for carbachol and to 45.7 ± 12.3% for norepinephrine. Amounts of RhoA, RhoB, RhoC, ROCK1, and ROCK2 were detected by immunoblot analysis in the prostate. Immunohistochemical study revealed that RhoA, RhoB, RhoC, ROCK1, and ROCK2 were all positive in the prostatic smooth muscle, while there were some differences of distributions of Immunoreactivities between these enzymes in the prostatic glandula. Our data indicated that rat prostate contains RhoA, RhoB, RhoC, ROCK1, and ROCK2, which play an important role in the autonomic nerve-mediated contractile responses in the prostate.
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Affiliation(s)
- Motoaki Saito
- Department of Pathophysiological and Therapeutic Science, Division of Molecular Pharmacology, Tottori University School of Medicine, 86 Nishimachi, Yonago 683-8503, Japan.
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de Godoy MAF, Rattan S. Role of rho kinase in the functional and dysfunctional tonic smooth muscles. Trends Pharmacol Sci 2011; 32:384-93. [PMID: 21497405 DOI: 10.1016/j.tips.2011.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 03/05/2011] [Accepted: 03/11/2011] [Indexed: 01/13/2023]
Abstract
Tonic smooth muscles play pivotal roles in the pathophysiology of debilitating diseases of the gastrointestinal and cardiovascular systems. Tonic smooth muscles differ from phasic smooth muscles in the ability to spontaneously develop myogenic tone. This ability has been primarily attributed to the local production of specific neurohumoral substances that can work in conjunction with calcium sensitization via signal transduction events associated with the Ras homolog gene family, member A (RhoA)/Rho-associated, coiled-coil containing protein kinase 2 (ROCK II) pathways. In this article, we discuss the molecular pathways involved in the myogenic properties of tonic smooth muscles, particularly the contribution of protein kinase C vs the RhoA/ROCK II pathway in the genesis of basal tone, pathophysiology and novel therapeutic approaches for certain gastrointestinal and cardiovascular diseases. Emerging evidence suggests that manipulation of RhoA/ROCK II activity through inhibitors or silencing of RNA interface techniques could represent a new therapeutic approach for various gastrointestinal and cardiovascular diseases.
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Affiliation(s)
- Márcio A F de Godoy
- Department of Medicine, Division of Gastroenterology and Hepatology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA, USA
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Guldali O, Savci V, Buyukafsar K. CDP-choline-induced contractions in the mouse gastric fundus through purinoceptors and Rho/Rho-kinase signalling. Life Sci 2011; 88:473-9. [PMID: 21219915 DOI: 10.1016/j.lfs.2011.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 12/08/2010] [Accepted: 12/23/2010] [Indexed: 10/18/2022]
Abstract
AIMS This study aimed to investigate the effects of cytidine-5'-diphosphocholine (CDP-choline), an endogenous lipid precursor, on the reactivity of the mouse gastric fundus and to determine the mechanism(s) mediating its effects. MAIN METHODS Possible contractile effect of CDP-choline (10(-5)-10(-2)M) was investigated in the absence and presence of a muscarinic receptor antagonist, atropine (3 × 10(-6)M), an acetylcholine esterase inhibitor, physostigmine (10(-6)M), a Na(+) channel blocker, tetrodotoxin (TTX, 3 × 10(-6)M), a Rho-kinase inhibitor, Y-27632 (10(-5) M), a purinoceptor antagonist, suramin (2 × 10(-4)M), a nitric oxide synthase inhibitor, N(G)-nitro-L-arginine (L-NA, 3 × 10(-4)M), a Ca(2+) channel blocker, nifedipine (10(-6)M), an α(7) nicotinic receptor antagonist, methyllycaconitine citrate (MLA, 10(-6)M) and a G protein (G(i/o)) inhibitor, pertussis toxin (PTX, 2 μg/ml). The metabolites of CDP-choline, namely choline (10(-4)-10(-2)M), cytidine 5'-triphosphate (CTP, 10(-5)-10(-2)M), cytidine (10(-5)-10(-2)M) and cytidine monophosphate (CMP, 10(-3)-10(-2)M) were also tested. Besides, phosphorylation of MYPT1, which indicates Rho-kinase activity, was also detected. KEY FINDINGS CDP-choline produced contractions in a concentration-dependent manner. The contractions were not affected by atropine, physostigmine, TTX, PTX, MLA or L-NA. However, Y-27632, suramin or nifedipine partly reduced these contractions. CDP-choline increased phosphorylation of MYPT1. Among CDP-choline metabolites, cytidine had no contractile effects. However, choline induced considerable contractions, which were sensitive to atropine. CMP and CTP had also contractile activity, comparable to that of CDP-choline. SIGNIFICANCE These results suggest that CDP-choline produced contraction through, at least in part, purinoceptors and Rho/Rho-kinase signalling in the mouse gastric fundus.
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Affiliation(s)
- Ozge Guldali
- Department of Pharmacology, Medical Faculty Mersin University, Campus Yenisehir, 33169, Mersin, Turkey
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Rattan S, Singh J. Basal internal anal sphincter tone, inhibitory neurotransmission, and other factors contributing to the maintenance of high pressures in the anal canal. Neurogastroenterol Motil 2011; 23:3-7. [PMID: 21188800 PMCID: PMC5547999 DOI: 10.1111/j.1365-2982.2010.01629.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Maintenance of the basal tone in the internal anal sphincter (IAS) is critical for rectoanal continence. Effective evacuation requires a fully functional rectoanal inhibitory reflex (RAIR)-mediated relaxation of the IAS via inhibitory neurotransmission (INT). Systematic studies examining the nature of the INT in different species have identified nitric oxide (NO) as the major inhibitory neurotransmitter. However, other mediators such as vasoactive intestinal polypeptide (VIP), ATP, and carbon monoxide (CO) may also play species-specific role under certain experimental conditions. Measurements of the intraluminal pressures in the IAS along with the force of the isolated IAS tissues are the mainstay in the basic studies for the molecular mechanisms underlying the basal tone and in the nature of the INT. The identification of NO as the inhibitory neurotransmitter has led to major advances in the diagnosis and treatment of a number of rectoanal motility disorders associated with the IAS dysfunction. Besides the IAS, the high pressures in the anal canal are affected by the external anal sphincter (EAS) function, and its malfunction may also lead to rectoanal incontinence. Different approaches including biofeedback have been attempted to improve the EAS function, with variable outcomes. There is a dire need for the innovative ways to improve the week high pressures zone in the anal canal. This viewpoint focuses on two studies that extend the above concept of multiplicity of inhibitory neurotransmitters (Neurogastroenterol Motil 2011 23 e11–25), and that high pressures in the anal canal can be improved by the EAS plication (Neurogastroenterol Motil 2011 23 70–5).
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Affiliation(s)
- S Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA, USA.
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Lavogina D, Nickl CK, Enkvist E, Raidaru G, Lust M, Vaasa A, Uri A, Dostmann WR. Adenosine analogue-oligo-arginine conjugates (ARCs) serve as high-affinity inhibitors and fluorescence probes of type I cGMP-dependent protein kinase (PKGIalpha). BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1804:1857-68. [PMID: 20406699 PMCID: PMC3071016 DOI: 10.1016/j.bbapap.2010.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/12/2010] [Accepted: 04/13/2010] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Type I cGMP-dependent protein kinase (PKGIalpha) belongs to the family of cyclic nucleotide-dependent protein kinases and is one of the main effectors of cGMP. PKGIalpha is involved in regulation of cardiac contractility, vasorelaxation, and blood pressure; hence, the development of potent modulators of PKGIalpha would lead to advances in the treatment of a variety of cardiovascular diseases. AIM Representatives of ARC-type compounds previously characterized as potent inhibitors and high-affinity fluorescent probes of PKA catalytic subunit (PKAc) were tested towards PKGIalpha to determine that ARCs could serve as activity regulators and sensors for the latter protein kinase both in vitro and in complex biological systems. RESULTS Structure-activity profiling of ARCs with PKGIalpha in vitro demonstrated both similarities as well as differences to corresponding profiling with PKAc, whereas ARC-903 and ARC-668 revealed low nanomolar displacement constants and inhibition IC(50) values with both cyclic nucleotide-dependent kinases. The ability of ARC-based fluorescent probes to penetrate cell plasma membrane was demonstrated in the smooth muscle tissue of rat cerebellum isolated arteries, and the compound with the highest affinity in vitro (ARC-903) showed also potential for in vivo applications, fully abolishing the PKG1alpha-induced vasodilation.
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Affiliation(s)
- Darja Lavogina
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Christian K. Nickl
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Erki Enkvist
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Gerda Raidaru
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Marje Lust
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Angela Vaasa
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Asko Uri
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Wolfgang R. Dostmann
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, VT 05405, USA
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Rattan S. 3-Hydroxymethyl coenzyme A reductase inhibition attenuates spontaneous smooth muscle tone via RhoA/ROCK pathway regulated by RhoA prenylation. Am J Physiol Gastrointest Liver Physiol 2010; 298:G962-9. [PMID: 20378830 PMCID: PMC3774330 DOI: 10.1152/ajpgi.00034.2010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
RhoA prenylation may play an important step in the translocation of RhoA in the basal internal anal sphincter (IAS) smooth muscle tone. Statins inhibit downstream posttranslational RhoA prenylation by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibition (HMGCRI). The role of statins in relation to RhoA prenylation in the pathophysiology of the spontaneously tonic smooth muscle has not been investigated. In the present studies, we determined the effect of classical HMGCRI simvastatin on the basal IAS tone and RhoA prenylation and in the levels of RhoA/Rho kinase (ROCK) in the cytosolic vs. membrane fractions of the smooth muscle. Simvastatin produced concentration-dependent decrease in the IAS tone (via direct actions at the smooth muscle cells). The decrease in the IAS tone by simvastatin was associated with the decrease in the prenylation of RhoA, as well as RhoA/ROCK in the membrane fractions of the IAS, in the basal state. The inhibitory effects of the HMGCRI were completely reversible by geranylgeranyltransferase substrate geranylgeranyl pyrophosphate. Relaxation of the IAS smooth muscle via HMGCRI simvastatin is mediated via the downstream decrease in the levels of RhoA prenylation and ROCK activity. Studies support the concept that RhoA prenylation leading to RhoA/ROCK translocation followed by activation is important for the basal tone in the IAS. Data suggest that the role of HMG-CoA reductase may go beyond cholesterol biosynthesis, such as the regulation of the smooth muscle tone. The studies have important implications in the pathophysiological mechanisms and in the novel therapeutic approaches for anorectal motility disorders.
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Affiliation(s)
- Satish Rattan
- 901 College, Dept. of Medicine, Div. of Gastroenterology & Hepatology, 1025 Walnut St., Philadelphia, PA 19107, USA.
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