title: Gallic acid selectively induces the necrosis of activated hepatic stellate cells via a calcium-dependent calpain I activation pathway.
abstract: OBJECTIVE
  The activation of hepatic stellate cells (HSCs) in response to liver injury is critical to the development of liver fibrosis, thus, the blockage of the activation of HSCs is considered as a rational approach for anti-fibrotic treatment. In this report, we investigated the effects and the underlying mechanisms of gallic acid (GA) in interfering with the activation of HSCs.
  
  
  METHODS
  The primary cultured rat HSCs were treated with various doses of GA for different time intervals. The morphology, viability, caspase activity, calcium ion flux, calpain I activity, reactive oxygen species generation and lysosomal functions were then investigated.
  
  
  RESULTS
  GA selectively killed HSCs in both dose- and time-dependent manners, while remained no harm to hepatocytes. Besides, caspases were not involved in GA-induced cell death of HSCs. Further results showed that GA toxicity was associated with a rapid burst of reactive oxygen species (ROS) and a subsequent increase of intracellular Ca(2+) and calpain activity. Addition of calpain I but not calpain II inhibitor rescued HSCs from GA-induced death. In parallel, pretreatment with antioxidants or an intracellular Ca(2+) chelator eradicated GA responses, implying that GA-mediated cytotoxicity was dependent on its pro-oxidative properties and its effect on Ca(2+) flux. Furthermore, application of ROS scavengers also reversed Ca(2+) release and the disruption of lysosomal membranes in GA-treated HSCs.
  
  
  CONCLUSIONS
  These results provide evidence for the first time that GA causes selective HSC death through a Ca(2+)/calpain I-mediated necrosis cascade, suggesting that GA may represent a potential therapeutic agent to combat liver fibrosis.
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan; Department of Education & Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Shu-Chung
authors.initials: SC
authors.lastname: Hsieh
authors.affiliation: School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chi-Hao
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Institute of Medicine, Chung-Shan Medical University, Taichung, Taiwan; Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Wu
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Jung-Hsing
authors.initials: JH
authors.lastname: Yen
authors.affiliation: Department of Education & Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Liu
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan. Electronic address: cmhsueh@dragon.nchu.edu.tw.
authors.forename: Chi-Mei
authors.initials: CM
authors.lastname: Hsueh
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan; Department of Education & Research, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Medicine, Chung-Shan Medical University, Taichung, Taiwan. Electronic address: h2326@vghtc.gov.tw.
authors.forename: Shih-Lan
authors.initials: SL
authors.lastname: Hsu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002154:Calpain / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005707:Gallic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D008103:Liver Cirrhosis / Q000473:pathology / Q000517:prevention & control; D008297:Male; D009336:Necrosis / Q000139:chemically induced; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D005707:Gallic Acid; D002154:Calpain; D002118:Calcium
keywords: Calcium; Calpain; Gallic acid; Hepatic stellate cells; Necrosis