Thalidomide Accelerates the Degradation of Extracellular Matrix in Rat Hepatic Cirrhosis via Down-Regulation of Transforming Growth Factor-beta1

PURPOSE: The degradation of the extracellular matrix has been shown to play an important role in the treatment of hepatic cirrhosis. In this study, the effect of thalidomide on the degradation of extracellular matrix was evaluated in a rat model of hepatic cirrhosis. MATERIALS AND METHODS: Cirrhosis was induced in Wistar rats by intraperitoneal injection of carbon tetrachloride (CCl4) three times weekly for 8 weeks. Then CCl4 was discontinued and thalidomide (100 mg/kg) or its vehicle was administered daily by gavage for 6 weeks. Serum hyaluronic acid, laminin, procollagen type III, and collagen type IV were examined by using a radioimmunoassay. Matrix metalloproteinase-13 (MMP-13), tissue inhibitor of metalloproteinase-1 (TIMP-1), and alpha-smooth muscle actin (alpha-SMA) protein in the liver, transforming growth factor beta1 (TGF-beta1) protein in cytoplasm by using immunohistochemistry and Western blot analysis, and MMP-13, TIMP-1, and TGF-beta1 mRNA levels in the liver were studied using reverse transcriptase polymerase chain reaction. RESULTS: Liver histopathology was significantly better in rats given thalidomide than in the untreated model group. The levels of TIMP-1 and TGF-beta1 mRNA and protein expressions were decreased significantly and MMP-13 mRNA and protein in the liver were significantly elevated in the thalidomide-treated group. CONCLUSION: Thalidomide may exert its effects on the regulation of MMP-13 and TIMP-1 via inhibition of the TGF-beta1 signaling pathway, which enhances the degradation of extracellular matrix and accelerates the regression of hepatic cirrhosis in rats.

Role of Matrix Metalloproteinase (MMP) 2 and MMP-9 in Soft Tissue Sarcoma

BACKGROUND: We investigated the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in malignant fibrous histiocytoma (MFH), and determined whether these could be useful as prognostic factors. METHODS: Among patients treated from 1993 to 2007, 30 cases of MFH were evaluated. Immunohistochemical staining was performed for MMP-2, MMP-9, TIMP-1, and TIMP-2 using paraffin wax-embedded blocks of MFH tissues. Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot and zymography were performed using fresh tissues obtained from 17 of the 30 cases. The levels of MMP and TIMP expression were compared between the MFH and normal control groups, and between non-metastatic and metastatic MFH groups. RESULTS: Expression levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were higher in the MFH group than the control group by RT-PCR, Western blotting, and zymography. Immunohistochemical staining revealed that MMP-2 and MMP-9 protein expression was higher in the metastatic than in the non-metastatic group. The expression levels of MMP-2 and TIMP-1 were significantly higher in the metastatic than in the non-metastatic group (p 0.05). Finally, gelatin zymography analysis showed that the expression levels of the pro- and active forms of MMP-2 were significantly higher in the metastatic group (p 0.05). CONCLUSIONS: These results suggest that MMP-2, MMP-9, TIMP-1, and TIMP-2 may have important roles in the development and progression of MFH, and that the degree of expression of these metalloproteinases and their inhibitors, especially MMP-2, could be useful as prognostic factors related to metastasis in MFH.

Effect of shRNA inhibiting HiF1alpha gene on TIMP1 expression in RPE cells / 华中科技大学学报（医学）（英德文版）

Small hairpin RNA (shRNA) was used to silence the HIF1alpha gene in human retinal pigment epithelial cells (RPE) under hypoxia in order to observe the effect of gene silencing on the expression of matrix metalloproteinase tissue inhibitor 1 (TIMP1). By using chemical hypoxic inducer CoCl2, to mimic RPE hypoxic environment, shRNA against the targeting region of HIF1alpha mRNA sequence was synthesized by a method of in vitro transcription, and the HIF1alpha was interfered in RPE cultured under hypoxia (induced by 150 micromol/L CoCl2). RT-PCR was employed to detect the expression of HIF1alpha and TIMP1. The expression levels of HIF1alpha and TIMP1 were measured by using Western blotting. The results showed that after the RPE were transfected with specific shRNA against HIF1alpha mRNA, RT-PCR revealed that under hypoxia, the efficacy of HIF1alpha gene silencing in RPE was 83.4%. Western blotting revealed that the expression levels of HIF1alpha protein was dramatically dropped. In addition. RT-PCR results demonstrated that the expression of TIMP1 mRNA was decreased by 28.9%, and the expression levels of TIMP1 protein were also significantly reduced by Western blotting. It was suggested that shRNA targeted against HIF1alpha mRNA could effectively silence the HIF1alpha gene, subsequently effectively inhibit the hypoxia-induced up-regulation of TIMP1.