Inhibitory effect of Ad-HGF on pulmonary fibrosis induced by bleomycin in rats

AIM:To explore the effect of human hepatocyte growth factor(HGF)via a recombinant adenovirus mediated HGF gene(Ad-HGF)on bleomycin(BLM)-induced pulmonary fibrosis in rats.METHODS:Sixty Wistar rats in good conditions were intratracheally instilled with BLM 0.5 mL(2 mg),and then randomly divided into 3 groups:Ad-HGF treatment group(group A),Ad-GFP treatment group(group B)and model control group(group C),20 rats each group.On the 2nd day after intratra-cheal administration of BLM,A,B and C groups were intratracheally instilled with 1×109 pfu Ad-HGF,1×109 pfu Ad-GFP and 0.5 mL normal saline,respectively.All rats were killed on day 14 after treatment.Collagen content of the lung tissue was assessed by hydroxyproline concentration.Distributions of collagen fiber 4 types in lung tissue of rats were observed and the degree of fibrosis was determined by semi-quantitative estimation of I type collagen fiber under polarizing microscope with stains of Sirius red.RESULTS:The concentration of hydroxyproline in rat lung tissue from Ad-HGF treatment group [(1.91±0.16)mg/g] was significantly lower than that in Ad-GFP treatment group [(3.27±0.43)mg/g] and model control group [(3.04±0.26)mg/g,P0.05].The sections stained with Sirius red showed type I collagen fiber was fewer in the Ad-HGF group(2.12±0.61),while a huge amount of type I collagen was observed in the sections from Ad-GFP treatment(3.17±0.56)and control group(3.38±0.66);there was significant difference between Ad-HGF group and Ad-GFP group or control group(P0.05).CONCLUSION:Ad-HGF can repress the formation of pulmonary fibrosis in rats.