[Effects of small interference RNA targeting connective tissue growth factor on hypoxia-induced collagen synthesis in human lung fibroblasts].

OBJECTIVE: To investigate the effects of small interference RNA (siRNA) targeting connective tissue growth factor (CTGF) on collagen synthesis induced by hypoxia in human lung fibroblasts. METHODS: CTGF-siRNA expression plasmid was stablely transfected into MRC-5. The transfected cells were cultured under hypoxia condition (37 degrees C, 5% CO2, 1% O2) for 1, 2, 4, 6 and 12 hours respectively. The expression of CTGF and collagen type I was assessed by real time quantitative PCR and Western blot. RESULTS: Expression of CTGF mRNA was up-regulated as early as 1 hour in control scrambled-siRNA/MRC-5 cells after exposed to hypoxia condition, which remained the elevated level up to 6 hours. Compared with control cells, the expression of CTGF mRNA and protein induced by hypoxia was decreased significantly in CTGF-siRNA/MRC-5 cells. Moreover, the deposition of collagen type I in CTGF-siRNA/MRC-5 cells was also declined. CONCLUSION: The siRNA targeting CTGF gene could efficiently inhibit collagen deposition induced by hypoxia in human lung fibroblasts.