Expression Of CTGF In Radiation-induced Hepatic Fibrosis Of Rats And Its Relation With Hepatic Stellate Cell Activation

Objective:To study the expression of connective tissue growth factor(CTGF)in hepatic fibrosis and explore its correlation with the expression of transforming growth factor beta?1(TGF-?1)anda-smooth muscle actin(a-SMA)as well as its relation with the activation of hepatic stellate cells(HSC).Methods:Forty healthy male Sprague-Dawley rats were randomly divided into model group(30 rats)and control group(10 rats).The right-half of rat liver in model group was irradiated with a single dose of 25 Gy to establish radiation-induced hepatic fibrosis model.Liver tissues from the irradiated liver were collected at different time points(2months,4months,6months) after irradiation. Pathomorphological change in the liver was observed with hematoxylin-eosin staining by optical microscope. The mRNA and protein expression of CTGF,TGF-?1 anda-SMA was assayed by reverse transcription-polymerase chain reaction(RT-PCR) and immunohisto-chemistry.Results:The longer the irradiation time,the degree of liver fibrosis is more serious and the expression of CTGF,TGF-?1,a-SMA protein in the model group at different time points after irradiation become more and more(F=55.44,16.22,121.12, P<0.05).The expressions of CTGF mRNA,TGF-?1 mRNA anda-SMA mRNA of model group at different time points after irradiation were significantly higher than the control group(F=177.11,133.85,217.46,P<0.05).There were positive correlation between the CTGF mRNA, TGF-?1 mRNA and a-SMA mRNA(r=0.638,0.715, P<0.05). Conclusion: The expression of CTGF increases with the development of hepatic fibrosis.CTGF may be involved in the activation of TGF-Psignaling pathway,thereby promoting the activation and proliferation of HSC in the development of hepatic fibrosis.