Effects of a plasmid expressing antisense tissue inhibitor of metalloproteinase-1 on liver fibrosis in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>The results demonstrate that antisense TIMP-1 recombinant plasmids have some inhibitory effect on liver fibrosis.</p>

Effects of antisense transforming growth factor beta receptor-II (TGFbetaRII) expressing plasmid on experimental liver fibrosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the effects of antisense transforming growth factor beta receptor-II (TGFbetaRII) expressing plasmid on experimental liver fibrosis.</p><p><b>METHODS</b>RT-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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSION</b>The 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.</p>

Effects of cisapride on intestinal bacterial and endotoxin translocation in cirrhotic rats / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To further investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats.</p><p><b>METHODS</b>25 normal control rats, 25 cirrhotic rats, 20 cirrhotic rats received saline, and 20 cirrhotic rats treated with cisapride were included in the study. All animals were assessed with many variables including bacterial and endotoxin translocation, IBO, intestinal transit and permeability.</p><p><b>RESULTS</b>Bacterial translocation was found in 48%(12/25) cirrhotic rats and none of control rats. Among the 20 rats with IBO, there were 11 rats with bacterial translocation (BT) while only one rats occurred BT out of the 5 rats without IBO. Cirrhotic rats with IBO had a significantly higher rate of endotoxin translocation, higher intestinal permeability and longer intestinal transit than those without IBO. BT of a specific organism was always associated with IBO of that organism. Compared with the placebo group, cisapride-treated rats had lower rates of bacterial and endotoxin translocation and IBO, which had close relationship with shorter intestinal transit and lower permeability.</p><p><b>CONCLUSION</b>Endotoxin and bacterial translocation in cirrhotic rats may be the result of IBO and higher permeability. IBO may be the result of longer transit. Cisapride which can accelerate intestinal transit and improve intestinal permeability is helpful in preventing and treating intestinal bacterial and endotoxin translocation.</p>