Effects of a plasmid expressing antisense tissue inhibitor of metalloproteinase-1 on liver fibrosis in rats.
BACKGROUND
No efficient therapy for liver fibrosis has been available. This study was aimed to provide evidence that the introduction of a plasmid expressing antisense tissue inhibitor of metalloproteinase-1 (TIMP-1) into a rat model of immunologically induced liver fibrosis can result in the increased activity of interstitial collagenase, thus enhancing the degradation of collagen.


METHODS
Real-time nested polymerase chain reaction (RT-Nested-PCR) and gene recombination techniques were used to construct a rat antisense TIMP-1 recombinant plasmid that can be expressed in eukaryotic cells. Both the recombinant plasmid and an empty vector (pcDNA3) were encapsulated with glycosyl-poly-L-lysine and injected into rats suffering from pig serum-induced liver fibrosis. The expression of exogenous transfected plasmid was assessed by Northern blot, RT-PCR, and Western blot. Hepatic interstitial collagenase activity was detected using fluorescinisothiocyanate (FITC)-labeled type I collagen. In addition to hepatic hydroxyproline content, hepatic collagen types I and III were detected by immunohistochemical staining, and the stages of liver fibrosis by Van Gieson staining.


RESULTS
Exogenous antisense TIMP-1 was successfully expressed in vivo and could block the gene and protein expression of TIMP-1. Active and latent hepatic interstitial collagenase activities were elevated (P < 0.01), hepatic hydroxyproline content and the accumulation of collagen types I and III were lowered, and liver fibrosis was alleviated in the antisense TIMP-1 group (P < 0.01) as compared with the model group.


CONCLUSIONS
The results demonstrate that antisense TIMP-1 recombinant plasmids have some inhibitory effect on liver fibrosis.
Jiang
Wei
W
Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Wang
Ji-Yao
JY
Yang
Chang-Qing
CQ
Liu
Wen-Bin
WB
Wang
Yi-Qing
YQ
He
Bo-Ming
BM
D000818:Animals; D016375:Antisense Elements (Genetics) / Q000627:therapeutic use*; D017364:Collagenases / Q000378:metabolism; D006909:Hydroxyproline / Q000032:analysis; D008099:Liver / Q000378:metabolism; D008106:Liver Cirrhosis, Experimental / Q000378:metabolism / Q000628:therapy*; D008297:Male; D010957:Plasmids; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000037:antagonists & inhibitors* / Q000235:genetics
D016375:Antisense Elements (Genetics); D019715:Tissue Inhibitor of Metalloproteinase-1; D017364:Collagenases; D006909:Hydroxyproline