Exogenous HGF Prevents Cardiomyocytes from Apoptosis after Hypoxia via Up-Regulating Cell Autophagy.
BACKGROUND
Hepatocyte growth factor (HGF) is widely known as a protective factor in ischemic myocardium, however HGF sensitive cellular mechanism remained ill-defined. Autophagy at early stage of hypoxia has been demonstrated to play a role in protecting myocardium both in vivo and vitro. We performed this study to investigate the association between the protective effect of HGF and autophagy.


METHODS
Ventricular myocytes were isolated from neonatal rat heart (NRVMs). We evaluated cardiomyocytes apoptosis by Hoechst staining and flow cytometry. Autophagy was assessed by transmission electron microscope and mRFP-GFP-LC3 adenovirus infection. Mitochondrial membrane potential was estimated by JC-1 staining. Western blotting and ELISA assay were used to quantify protein concentrations.


RESULTS
We found that autophagy in NRVMs increased at early stage after hypoxia and HGF release was consistent with the change of autophagy. Exogenous HGF enhanced autophagy and decreased apoptosis, while neutralizing HGF yielded opposite effects. Besides, inhibition of autophagy increased apoptosis of myocytes. Furthermore, exogenous HGF induced Parkin, the marker of mitochondrial autophagy, indicating increased clearance of injured mitochondria.


CONCLUSIONS
Our results revealed a potential mechanism in which exogenous HGF prevented NRVMs from apoptosis after hypoxia. Upregulation of Parkin through administration of exogenous HGF may be a potential therapeutic strategy ptotecting myocytes during ischemia.
Yunle
Y
Wang
Jiabao
J
Liu
Zhiwen
Z
Tao
Peng
P
Wu
Weili
W
Cheng
Yingqiang
Y
Du
Ningtian
N
Zhou
Yingbin
Y
Ge
Zhijian
Z
Yang
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D015687:Cell Hypoxia / Q000187:drug effects; D002478:Cells, Cultured; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects* / Q000473:pathology; D017207:Rats, Sprague-Dawley
D002316:Cardiotonic Agents; D017228:Hepatocyte Growth Factor