ABSTRACT
BACKGROUND:Cirrhosis is a long-term consequence of chronic hepatic injury, which has no effective therapy. Mesenchymal stem cels have been shown to play a potential role in the treatment of liver fibrosis/cirrhosis. OBJECTIVE:To investigate the therapeutic effect and mechanism of human umbilical cord-derived mesenchymal stem cels on CCl4 induced liver fibrosis/cirrhosis in rats. METHODS:A CCl4-induced liver fibrotic/cirrhotic rat model was used, and human umbilical cord-derived mesenchymal stem cels were injectedvia the tail vein after modeling. Liver biochemical profile was measured by Beckman Coulter analyzer. Histopathological changes were assessed by Sirius red staining. The expressions of colagen type I, colagen type III, matrix metaloproteinases-2 and tissue inhibitor of matrix metaloproteinases-2 protein and mRNA in liver tissues were observed by immunohistochemistry, western blot and real-time PCR, respectively. RESULTS AND CONCLUSION:Liver biochemical profile indicated the transplantation of human umbilical cord-derived mesenchymal stem cels could improve the liver function of rats with liver fibrosis and cirrhosis. After cel transplantation, except 1-week cel transplantation group, the expressions of the matrix metaloproteinases-2 mRNA and protein were significantly increased, while the expressions of colagen type I, colagen type III and tissue inhibitor of matrix metaloproteinases-2 mRNA and protein significantly decreased, compared with the corresponding model groups. Human umbilical cord-derived mesenchymal stem cels play a role in the treatment of liver fibrosis and cirrhosis through upregulating the expression of matrix metaloproteinases-2 and lowering the expression of inhibitor of matrix metaloproteinases-2. With the continued presence of pathogenic factors, human umbilical cord-derived mesenchymal stem cel transplantation cannot reverse liver fibrosis or cirrhosis, and only delay the process of liver fibrosis or cirrhosis.
ABSTRACT
BACKGROUND:Matrix metaloproteinase-1 can degrade extracelular matrix, which is mainly colagen type I, and has the potential to reverse fibrosis tissue. OBJECTIVE:To construct the recombinant adenovirus vector containing human matrix metaloproteinase-1 (hMMP-1) gene with GatewayTM Clone Technology, and observe the capacity of degrading colagen type IIIin vitro. METHODS: The gene hMMP-1 was amplified by using PCR from the pcDNA3.1 plasmid and was cut down by the double endonuclease. The linear gene fragment was connected to the entry vector pENTERTM 1A. Then the entry clone and the destination vectors pJTI? R4 Dest CMV-N-EmGFP pA Vector recombined using the LR reaction to form the expression clone pAd-hMMP-1-eGFP. The linear pAd-hMMP-1-eGFP cut down by endonucleasePac I was transfected into HEK293A cels to packaging the Ad-hMMP-1-eGFP. The transfected situation was observed under a fluorescence microscope, the target protein expression was detected by western-blot assay and RT-PCR. Cels can be divided into three groups: blank control group: HEK293A cels, AD-EGFP group: HEK293A cels were infected by Ad-eGFP, AD-HMMP1-EGF group: HEK293A cels were infected by Ad-hMMP1-eGFP and colagen type III. The content of colagen type III was detected by ELISA kits after 24, 48 and 72 hours. RESULTS AND CONCLUSION: It was confirmed that the entry vector and the destination vector both contained hMMP-1 target gene by restriction analysis and sequencing. The green fluorescent protein was observed in the 293A cels transfected by the Ad-hMMP-1-eGFP at 4 days. The fluorescence intensity was the highest at 10 days. The virus was colected at 12 days, the viral titer was determined as 4.84 × 1010 PFU/mL, the target protein was efficient expressionvia western-blot assay. Blank control group and AD-EGFP group had no obvious change of colagen content with the extension of time. The rate of colagen degradation in AD-HMMP1-EGFP group was 24%, 56% and 81% respectively at 24, 48, 72 hours. AD-HMMP1-EGFP group degraded colagen significantly compared with the other two groups (P < 0.01). The recombinant adenovirus vector containing hMMP-1 was successfuly constructed by using the Gateway technology, this method was more efficient and specific than with the traditional methods. The hMMP1 degraded colagen type III significantlyin vitro.