Aim: To investigate serotonergic Ca²+ signaling and the expression of 5-hydroxytryptamine (5-HT) receptors, as well as Ca²+ transporting proteins, in hepatic stellate cells (HSCs).
Methods: The intracellular Ca²+ concentration [Ca²+](i) of isolated rat HSCs was measured with a fluorescence microscopic imaging system. Quantitative PCR was performed to determine the transcriptional levels of 5-HT receptors and endoplasmic reticulum (ER) proteins involved in Ca²+ storage and release in cultured rat HSCs.
Results: Distinct from quiescent cells, activated HSCs exhibited [Ca²+](i) transients following treatment with 5-HT, which was abolished by U-73122, a phospholipase C inhibitor. Upregulation of 5-HT(2A) and 5-HT(2B) receptors, but not 5-HT₃, was prominent during trans-differentiation of HSCs. Pretreatment with ritanserin, a 5-HT₂ antagonist, inhibited [Ca²+](i) changes upon application of 5-HT. Expression of type 1 inositol-5'-triphosphate receptor and type 2 sarcoplasmic/endoplasmic reticulum Ca²+ ATPase were also increased during activation of HSCs and serve as the major isotypes for ER Ca²+ storage and release in activated HSCs. Ca²+ binding chaperone proteins of the ER, including calreticulin, calnexin and calsequestrin, were up-regulated following activation of HSCs.
Conclusion: The appearance of 5-HT-induced [Ca²+](i) response accompanied by upregulation of metabotropic 5-HT₂ receptors and Ca²+ transporting/chaperone ER proteins may participate in the activating process of HSCs.
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http://dx.doi.org/10.3748/wjg.v17.i2.164 | DOI Listing |
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College of Pharmacy and Food, Southwest Minzu University, Chengdu 610093, China.
Hepatic fibrosis (HF) is an important pathological state in the progression of chronic liver disease to end-stage liver disease and is usually triggered by alcohol, nonalcoholic fatty liver, chronic hepatitis viruses, autoimmune hepatitis (AIH), or cholestatic liver disease. Research on novel therapies has become a hot topic due to the reversibility of HF. Research into the molecular mechanisms of the pathology of HF and potential drug screening relies on reliable and rational biological models, mainly including animals and cells.
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Laboratory of Nutritional Biochemistry, National Institute of Gastroenterology IRCCS "Saverio de Bellis", 70013 Castellana Grotte, Italy.
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Institute for Biostructure and Bioimaging, National Research Council, Molecular Biotechnology Centre "Guido Tarone", 10126 Turin, Italy.
Chronic hepatobiliary damage progressively leads to fibrosis, which may evolve into cirrhosis and/or hepatocellular carcinoma. The fight against the increasing incidence of liver-related morbidity and mortality is challenged by a lack of clinically validated early-stage biomarkers and the limited availability of effective anti-fibrotic therapies. Current research is focused on uncovering the pathogenetic mechanisms that drive liver fibrosis.
View Article and Find Full Text PDFAntioxidants (Basel)
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Department of Clinical Internal, Anesthesiological and Cardiovascular Sciences, Sapienza University of Rome, 00185 Rome, Italy.
Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by lipid accumulation in the liver due to an excess in their supplies or an impairment in their management. While some patients remain stable for years, a proportion of them progress up to steatohepatitis (MASH). MASLD links with systemic pathways being associated with metabolic and non-metabolic diseases.
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