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Autophagy: a Novel Mechanistic Contributor to Ursodeoxycholic Acid in Alleviating Progression of Hepatic Fibrosis
Author(s) -
Ye HuiLan,
Zhang JiWang,
Chen XingZhou,
Chen Li,
Zhang FaCan,
Zhang Guo
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1195.7
Subject(s) - autophagy , ursodeoxycholic acid , hepatic stellate cell , atg5 , hepatic fibrosis , fibrosis , chemistry , cancer research , blot , small interfering rna , chloroquine , pharmacology , microbiology and biotechnology , biology , apoptosis , medicine , endocrinology , immunology , rna , biochemistry , malaria , gene
Ursodeoxycholic acid (UDCA) has been found an increasingly wide utilization in the treatment of cholestatic liver fibrosis, especially for primary biliary cholangitis (PBC) and its detailed mechanisms remain unclear. Herein, this study was aimed to determine whether autophagic signaling is involved in the therapeutic effect of UDCA for liver fibrosis. Firstly, by using immunohistochemistry and fluorescent microscopic technology, autophagic molecule LC3 was found to highly express in human liver fibrotic tissues and TGFβ1 treated LX2 hepatic stellate cells(HSCs). With qRT‐PCR, autophagy promotion with rapamycin, the autophagic agonist, resulted in dramatic increment of cellular COL1A2 mRNA level, whereas blocking autophagic signaling with 3‐MA or hydroxychloroquine (HCQ) or small interference RNAs lead to decrement of COL1A2 mRNA transcription. Secondly, western blotting, qRT‐PCR and trypan blue were conducted to analyze autophagy flux, cell proliferation and collagen production in UDCA treated HSCs. UDCA treatment was found to dose‐dependently inhibit autophagy, cell proliferation as well as COL1A2 mRNA generation in TGFβ1 activated HSCs. The presence of rapamycin was shown to substantially impair the antic‐fibrotic effects of UDCA on these cells, while autophagy suppression with siRNAs targeting Atg5 or Beclin1 achieved marginally therapeutic effect. Finally, the anti‐fibrotic effect and autophagy were analyzed in CCl 4 ‐induced liver fibrosis of rats by H&E, masson staining, qRT‐PCR and western blotting. It was found that administration of rapamycin mildly thickened fibrous septa in rats with hepatic fibrosis. However, UDCA alone or in combined with HCQ notably restored the CCl4‐induced tissue architecture disruption and collagen aggregation following inhibitory impact on autophagic signaling hallmark as LC3 IIprotein expression and P62 degradation in these rodent models. Taken together, the present study firstly revealed that UDCA displays the anti‐fibrotic role of by protecting HSC against excessive production of collagen through autophagy inhibition and provide a new insight into the pharmacological basis of UDCA treatment for hepatic fibrosis. Support or Funding Information National Natural Science Foundation of China, NO.30960145, NO.81360077, NO.81172260 and Guangxi Natural Science Foundation, NO.2015GXNSFDA139022, zhangguogx@hotmail.com