Down-regulation of hepatocyte growth factor mRNA in rat cardiac myocytes under hypoxia mimicked by cobalt chloride

Hypoxia is generally considered to represent a fundamental stimulus for angiogenesis. Most angiogenic factors were up-regulated by hypoxia, but as a strong angiogenic and antiapoptotic factor, hepatocyte growth factor (HGF) was down-regulated by hypoxia. In order to investigate whether hypoxia inducible factor 1a (HIF-1α) participate in the transcriptional regulation of HGF under hypoxia, rat cardiac myocytes were treated with cobalt chloride (CoCl₂), the specific inducer of HIF-1α, for different times, and total RNA and protein were isolated to perform RT-PCR and Western blot. Results show the expression of HGF mRNA in cardiac myocytes decreased distinctively after treating with CoCl₂ for 12 hours. However, at the same time, the expression of HIF-1α protein was up-regulated. HIF-1α may be participate in the transcriptional regulation of HGF indirectly.