%0 Journal Article
%T Switching-on of serotonergic calcium signaling in activated hepatic stellate cells
%A Kyu-Sang Park
%A Pyo-Jin Sin
%A Dong Hyeon Lee
%A Seung-Kuy Cha
%A Min-Jeong Kim
%A Na-Hyun Kim
%A Soon-Koo Baik
%A Seong-Woo Jeong
%A In Deok Kong
%J World Journal of Gastroenterology
%D 2011
%I Baishideng Publishing Group Co. Limited
%X 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-HT2A and 5-HT2B 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-5กฏ-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.
%K Hepatic stellate cells
%K 5-hydroxytryptamine
%K Intracellular Ca2+ transient
%K Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase
%K Inositol-5กฏ-triphosphate receptor
%K Endoplasmic reticulum chaperone
%U http://www.wjgnet.com/1007-9327/full/v17/i2/164.htm