ABSTRACT
Objective To observe the effect of Valsartan on a rat model of acute lung injury and the expression of transforming growth factor-β,TGF-β) ,Smad2/3, Smad7. Methods Twenty-four male adult Sprague-Dawley rats were random divided into three groups : The bleomycin (BLM) group, the control group, and the Valsartan group. Each group contained eight rats. The Valsartan group was treated with Valsartan everyday at a dose of 20 mg/kg after a single intratracheal instillation of bleomycin at a dose of 5mg/kg. BLM group was treated with saline instead of Valsartan after an instillation of bleomycin. The control group was treated with saline instead of Valsartan and bleomycin. Each group was killed at the 7th day after instillation. The lung tissues were harvested for H. E. stain, the immunohistochemistry was used to detect the expressions of TGF-β1, Smad2/3 ,and Smad7. Results The degree of alveolitis in the Valsartan group was ameliorated, compared with those in BLM group (P ＜0. 01). The expressions of TGF-β1 and Smad2/3 in lung tissue of the Valsartan group were significantly lower than that of BLM group(P ＜0. 01). The expressions of Smad7 in lung tissue of the Valsartan group were significantly higher than that of BLM group (0.23 ±0. 02 vs0. 36 ±0.03, P ＜0.01). Conclusions Valsartan could alleviate acute lung injury in rats, which probably be due to the expression decrease of TGF-β1 and Smad2/3 and the expression increase of Smad7 in lung tissues.
ABSTRACT
Objective To construct transforming growth factor β receptor Ⅱ (TGFβRⅡ) siRNA expression vector, and investigate the inhibitory effect on TGFβRⅡ in hepatic stellate cells (HSC-T6) ,thus offer a preliminary study for RNAi therapy in liver fibrosis. Methods The two sites of RNAi action were selected in TGFβRⅡ cDNA through online primer design software of Ambion company. The corresponding double-stranded DNA sequence was constructed into pSilencer-U6 plasmid, which could transcribe small interference RNA, the plasmid was transfected into HSC-T6 cells with Lipofectamine 2000. The expression of TGFβRⅡ mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. Results Expression siRNA plasmids of siRNA-a and siRNA-b that target TGFβRⅡ were successfully constructed. Compared with control group, the expression of TGFβRⅡ mRNA was reduced by 0. 89 ± 0. 06 and 0. 25 ± 0. 03 in two siRNA groups, and expression of TGFβRⅡ protein reduced to 0. 86± 0. 05 and 0. 23 ± 0. 02, respectively. TGFβRⅡ expression was inhibited at mRNA and protein levels after transfected with the siRNA-b plasmid( P <0. 01 ).. There was no difference in the TGFβRⅡ expression after transfected with the siRNA-a plasmid( P > 0. 05). Conclusion TGFβRⅡ-siRNA can effective inhibit expression of TGFβRⅡ in HSC-T6.