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Bile canaliculi contract autonomously by releasing calcium into hepatocytes via mechanosensitive calcium channel. Biomaterials 2020; 259:120283. [PMID: 32827796 DOI: 10.1016/j.biomaterials.2020.120283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/17/2020] [Accepted: 08/01/2020] [Indexed: 12/12/2022]
Abstract
Drug-induced hepatocellular cholestasis leads to altered bile flow. Bile is propelled along the bile canaliculi (BC) by actomyosin contractility, triggered by increased intracellular calcium (Ca2+). However, the source of increased intracellular Ca2+ and its relationship to transporter activity remains elusive. We identify the source of the intracellular Ca2+ involved in triggering BC contractions, and we elucidate how biliary pressure regulates Ca2+ homeostasis and associated BC contractions. Primary rat hepatocytes were cultured in collagen sandwich. Intra-canalicular Ca2+ was measured with fluo-8; and intra-cellular Ca2+ was measured with GCaMP. Pharmacological modulators of canonical Ca2+-channels were used to study the Ca2+-mediated regulation of BC contraction. BC contraction correlates with cyclic transfer of Ca2+ from BC to adjacent hepatocytes, and not with endoplasmic reticulum Ca2+. A mechanosensitive Ca2+ channel (MCC), Piezo-1, is preferentially localized at BC membranes. The Piezo-1 inhibitor GsMTx-4 blocks the Ca2+ transfer, resulting in cholestatic generation of BC-derived vesicles whereas Piezo-1 hyper-activation by Yoda1 increases the frequency of Ca2+ transfer and BC contraction cycles. Yoda1 can recover normal BC contractility in drug-induced hepatocellular cholestasis, supporting that Piezo-1 regulates BC contraction cycles. Finally, we show that hyper-activating Piezo-1 can be exploited to normalize bile flow in drug-induced hepatocellular cholestasis.
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Gupta K, Li Q, Fan JJ, Fong ELS, Song Z, Mo S, Tang H, Ng IC, Ng CW, Pawijit P, Zhuo S, Dong CY, Low BC, Wee A, Dan YY, Kanchanawong P, So P, Viasnoff V, Yu H. Actomyosin contractility drives bile regurgitation as an early response during obstructive cholestasis. J Hepatol 2017; 66:1231-1240. [PMID: 28189756 DOI: 10.1016/j.jhep.2017.01.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 01/10/2017] [Accepted: 01/29/2017] [Indexed: 01/06/2023]
Abstract
BACKGROUND & AIMS A wide range of liver diseases manifest as biliary obstruction, or cholestasis. However, the sequence of molecular events triggered as part of the early hepatocellular homeostatic response in obstructive cholestasis is poorly elucidated. Pericanalicular actin is known to accumulate during obstructive cholestasis. Therefore, we hypothesized that the pericanalicular actin cortex undergoes significant remodeling as a regulatory response to obstructive cholestasis. METHODS In vivo investigations were performed in a bile duct-ligated mouse model. Actomyosin contractility was assessed using sandwich-cultured rat hepatocytes transfected with various fluorescently labeled proteins and pharmacological inhibitors of actomyosin contractility. RESULTS Actomyosin contractility induces transient deformations along the canalicular membrane, a process we have termed inward blebbing. We show that these membrane intrusions are initiated by local ruptures in the pericanalicular actin cortex; and they typically retract following repair by actin polymerization and actomyosin contraction. However, above a certain osmotic pressure threshold, these inward blebs pinch away from the canalicular membrane into the hepatocyte cytoplasm as large vesicles (2-8μm). Importantly, we show that these vesicles aid in the regurgitation of bile from the bile canaliculi. CONCLUSION Actomyosin contractility induces the formation of bile-regurgitative vesicles, thus serving as an early homeostatic mechanism against increased biliary pressure during cholestasis. LAY SUMMARY Bile canaliculi expand and contract in response to the amount of secreted bile, and resistance from the surrounding actin bundles. Further expansion due to bile duct blockade leads to the formation of inward blebs, which carry away excess bile to prevent bile build up in the canaliculi.
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Affiliation(s)
- Kapish Gupta
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Qiushi Li
- Mechanobiology Institute, National University of Singapore, Singapore; National University of Singapore Research Institute, Singapore
| | - Jun Jun Fan
- Institute of Bioengineering and Nanotechnology, Agency for Science, Technology and Research (A*STAR), Singapore; BioSyM, Singapore-MIT Alliance for Research and Technology, Singapore; Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, China
| | - Eliza Li Shan Fong
- Department of Physiology, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Ziwei Song
- Institute of Bioengineering and Nanotechnology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Shupei Mo
- Institute of Bioengineering and Nanotechnology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Haoyu Tang
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Inn Chuan Ng
- Department of Physiology, National University of Singapore, Singapore
| | - Chan Way Ng
- Department of Physiology, National University of Singapore, Singapore
| | - Pornteera Pawijit
- Department of Physiology, National University of Singapore, Singapore; NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Shuangmu Zhuo
- BioSyM, Singapore-MIT Alliance for Research and Technology, Singapore; Fujian Normal University, Fuzhou, Fujian, China
| | - Chen-Yuan Dong
- Department of Physics, National Taiwan University, Taiwan
| | - Boon Chuan Low
- Mechanobiology Institute, National University of Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore
| | - Aileen Wee
- Department of Pathology, National University of Singapore, Singapore
| | - Yock Young Dan
- Division of Gastroenterology and Hepatology, National University Hospital, Singapore
| | - Pakorn Kanchanawong
- Mechanobiology Institute, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Peter So
- BioSyM, Singapore-MIT Alliance for Research and Technology, Singapore
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore, Singapore; CNRS UMI3639, Singapore
| | - Hanry Yu
- Mechanobiology Institute, National University of Singapore, Singapore; Institute of Bioengineering and Nanotechnology, Agency for Science, Technology and Research (A*STAR), Singapore; BioSyM, Singapore-MIT Alliance for Research and Technology, Singapore; Department of Physiology, National University of Singapore, Singapore; Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Effects of anthropogenic sound on digging behavior, metabolism, Ca(2+)/Mg(2+) ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta. Sci Rep 2016; 6:24266. [PMID: 27063002 PMCID: PMC4827120 DOI: 10.1038/srep24266] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 03/23/2016] [Indexed: 11/25/2022] Open
Abstract
Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.
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Hu Y, Jin H, Du X, Xiao C, Luo D, Wang B, She R. Effects of chronic heat stress on immune responses of the foot-and-mouth disease DNA vaccination. DNA Cell Biol 2007; 26:619-26. [PMID: 17688414 DOI: 10.1089/dna.2007.0581] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The main purpose of this study was to assess the effects of chronic heat stress (CHS) on humoral and cellular responses of DNA vaccination. Mice with the CHS were exposed to a temperature set at 38 +/- 1 degrees C, 2h per day, for 35 days, and mice with thermoneutral (TN) temperature were maintained at 24 +/- 1 degrees C for the same period of time. Both groups of mice were immunized with a DNA vaccine-expressed viruscapsid protein 1 (VP1) of foot-and-mouth disease virus (FMDV), and we tested their antigen-specific humoral and cellular responses during the treatments. Compared with the TN group, titers of total Imunoglobulin G (IgG) and IgG1 and expression of interleukin 4 (IL-4) in CD4(+) cells of CHS group were not affected significantly. In contrast, the levels of IgG2a, T cell proliferations, and expression of interferon-gama (IFN-gamma) in both CD4(+) and CD8(+) cells were suppressed significantly, and cytotoxic T-lymphocyte (CTL) responses in vivo were also weakened by the CHS condition. These results indicate that the CHS treatment has negatively affected the immune responses of DNA vaccination and particularly impaired to the cell-mediated responses. It suggests that vaccination in animals is affected by the changes of ambient temperature.
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Affiliation(s)
- Yanxin Hu
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Li K, Qiao J, Zhao L, Dong S, Ou D, Wang J, Wang H, Xu T. Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens. ACTA ACUST UNITED AC 2007; 53:458-63. [PMID: 17054481 DOI: 10.1111/j.1439-0442.2006.00856.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.
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Affiliation(s)
- K Li
- Department of Animal Physiopathology, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
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Schmitt-Graeff A, Jing R, Nitschke R, Desmoulière A, Skalli O. Synemin expression is widespread in liver fibrosis and is induced in proliferating and malignant biliary epithelial cells. Hum Pathol 2006; 37:1200-10. [PMID: 16938526 DOI: 10.1016/j.humpath.2006.04.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 04/18/2006] [Accepted: 04/20/2006] [Indexed: 01/13/2023]
Abstract
The expression profile of intermediate filament proteins provides valuable information on the differentiation of specific cell populations and their contributions to disease. Synemin is one of the few intermediate filament proteins whose expression pattern during pathological situations is poorly characterized. We conducted a systematic immunohistochemical investigation of synemin expression in human liver diseases. In normal liver and in the early prefibrotic phase of chronic viral hepatitis or steatohepatitis, synemin was localized in hepatic stellate cells (HSCs) and vascular cells. Fibrotic or cirrhotic liver disease promoted intense synemin staining of HSCs in parenchymal and fibrous zones. In portal tract fibroblasts, synemin expression was rare under normal conditions but was widespread in severe inflammatory diseases associated with portal expansion, consistent with the notion that some fibrotic reactions involve HSCs, whereas others involve both HSCs and portal fibroblasts. Most sinusoidal endothelial cells were synemin negative in normal liver but were positive in hepatocellular carcinomas. Synemin was also expressed in the epithelial component of the ductular reaction in various liver diseases and in cholangiocarcinoma cells but not in hepatocellular carcinoma cells. Myofibroblasts in stromal reaction to carcinomas were synemin positive. Thus, synemin helps delineate different types of liver fibrotic reactions and provides a marker for sinusoidal capillarization and for proliferating biliary epithelial and cholangiocarcinoma cells.
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Affiliation(s)
- Annette Schmitt-Graeff
- Department of Pathology, University of Freiburg Medical School, D-79002 Freiburg, Germany
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Qiu Y, Li YY, Li SG, Song BG, Zhao GF. Effect of Qingyitang on activity of intracellular Ca 2+ -Mg 2+ -ATPase in rats with acute pancreatitis. World J Gastroenterol 2004; 10:100-4. [PMID: 14695778 PMCID: PMC4717058 DOI: 10.3748/wjg.v10.i1.100] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To study the change of intracellular calcium-magnesium ATPase (Ca2+ -Mg2+ -ATPase) activity in pancreas, liver and kidney tissues of rats with acute pancreatitis (AP), and to investigate the effects of Qingyitang (QYT) (Decoction for clearing the pancreas) and tetrandrine (Tet) and vitamin E (VitE) on the activity of Ca2+ -Mg2+ -ATPase.
METHODS: One hundred and five Sprague-Dawley rats were randomly divided into: normal control group, AP group, treatment group with QYT (1 mL/100 g) or Tet (0.4 mL/100 g) or VitE (100 mg/kg). AP model was prepared by a retrograde injection of sodium taurocholate into the pancreatic duct. Tissues of pancreas, liver and kidney of the animals were taken at 1 h, 5 h, 10 h respectively after AP induction, and the activity of Ca2+ -Mg2+ -ATPase was studied using enzyme-histochemistry staining. Meanwhile, the expression of Ca2+ -Mg2+ -ATPase of the tissues was studied by RT-PCR.
RESULTS: The results showed that the positive rate of Ca2+ -Mg2+ -ATPase in AP group (8.3%, 25%, 29.2%) was lower than that in normal control group (100%) in all tissues (P < 0.01), the positive rate of Ca2+ -Mg2+ -ATPase in treatment group with QYT (58.3%, 83.3%, 83.3%), Tet (50.0%, 70.8%, 75.0%) and VitE (54.2%, 75.0%, 79.2%) was higher than that in AP group (8.3%, 25.0%, 29.2%) in all tissues (P < 0.01). RT-PCR results demonstrated that in treatment groups Ca2+ -Mg2+ -ATPase gene expression in pancreas tissue was higher than that in AP group at the observing time points, and the expression at 5 h was higher than that at 1 h. The expression of Ca2+ -Mg2+ -ATPase in liver tissue was positive, but without significant difference between different groups.
CONCLUSION: The activity and expression of intracellular Ca2+ -Mg2+ -ATPase decreased in rats with AP, suggesting that Ca2+ -Mg2+ -ATPase may contribute to the occurrence and development of cellular calcium overload in AP. QYT, Tet and VitE can increase the activity and expression of Ca2+ -Mg2+ -ATPase and may relieve intracellular calcium overload to protect the tissue and cells from injuries.
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Affiliation(s)
- Ying Qiu
- Department of Pathophysiology, Medical School of Tongji University, Shanghai 200331, China
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