OBJECTIVETo study the effects of antisense transforming growth factor beta receptor-II (TGFbetaRII) expressing plasmid on experimental liver fibrosis.

METHODSRT-Nest-PCR and gene recombinant techniques were used to construct the rat antisense TGFbetaRII recombinant plasmid which can be expressed in eukaryotic cells. Thirty-six male SD rats were randomly distributed into five groups: 10 in experimental liver fibrosis model induced by pig-serum as disease control group; 10 in antisense TGFbetaRII transfection as treatment group; 10 in pCDNA3 transfection as treatment control group and 6 in normal control group. The recombinant plasmid and empty vector (pCDNA3) were encapsulated by glycosyl-poly-L-lysine and then transducted into rats of pig serum-induced liver fibrosis model respectively. Expression of exogenous transfected plasmid was assessed by Northern blot, RT-PCR and Western blot. We also tested ELISA of serum TGF-beta1, the contents of hepatic hydroxyproline, immunohistochemistry of type I and III collagen, and VG staining for pathological study.

RESULTSThe antisense TGFbetaRII expressing plasmid could be well expressed in vivo, and could block the mRNA and protein expression of TGFbetaRII in the fibrotic liver induced by pig serum. Its expression also reduced the level of TGF-beta1 [antisense treatment group (23.16+/-3.13) ng/ml, disease control group (32.96+/-3.79) ng/ml; F=36.73, 0.01]. Compared with the disease control group, the contents of hepatic hydroxyproline [antisense treatment group (0.17+/-0.01) mg/g liver, disease control group (0.30+/-0.03) mg/g liver; F=15.48, 0.01] and the deposition of collagens type I and type III decreased in the antisense group (antisense treatment group collagen type I 650.26+/-51.51, collagen type III 661.58+/-55.28; disease control group type I 1209.44+/-116.60, collagen type III 1175.14+/-121.44; F values are 69.87, 70.46, 0.01). And its expression also improved the pathologic classification of liver fibrosis models (0.01).

CONCLUSIONThe results demonstrate that TGF-beta plays a key role in liver fibrogenesis and the prevention of liver fibrosis by antisense TGFbetaRII recombinant plasmid intervention may be therapeutically useful.