Expressions of matrix metalloproteinases 1 and 3 and their tissue inhibitors in the conjunctival tissue and fibroblasts cultured from conjunctivochalasis

AIM：To investigate the expression of matrix metalloproteinases 1 and 3（MMP-1 and MMP-3） and their tissue inhibitors of metalloproteinases 1 and 3（ TIMP-1 and TIMP-3） in the conjunctiva of eyes with conjunctivochalasis（CCh）.METHODS：The conjunctival tissue was obtained from the CCh patients and controls,the MMPs/TIMPs expression concentration was determined by enzyme-linked immunosorbent assay（ELISA） and immunofluorescence staining.The expression levels of MMPs/TIMPs in the CCh fibroblasts were determined by analyzing its concentration in the cellular supernatant that was abstracted from the in vitro cultured CCh fibroblasts.RESULTS：MMP-1 and MMP-3 levels determined by ELISA were both significantly higher in the CCh group than that in the control group（P= 0.042,0.022,respectively）,so was the levels of TIMP-1（P= 0.010）.No significant difference in the expression of TIMP-3 in conjunctiva was found between the two groups（P= 0.298）.The expression of MMP-1 and MMP-3 were both up-regulated significantly in the CCh group（P= 0.040,0.001,respectively） on immunofluorescence staining.MMP-1 and MMP-3 expression in the fibroblasts were both significantly higher in the CCh group than that in the control group（P= 0.027,0.001,respectively）,while neither the TIMP-1 nor TIMP-3 expression was significantly different between the two groups（P= 0.421,0.237,respectively）.CONCLUSION：The overexpression of MMP-1 and MMP-3 in conjunctival tissue and fibroblasts may play an important role in the pathogenesis and development of CCh.

MATRIX METALLOPROTEINASE AND THEIR INHIBITORS: MOLECULAR ASPECTS OF THEIR ROLES IN THE TUMOR METASTASIS

The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes, whose physiological functions include tissue remo-delling and embryogenesis. The importance of this group of proteins in the processes of tumor invasion and metastasis is now widely acknowledged, and has led to the search for MMP inhibitors for use as anticancer treatments in a clinical setting. The review aims to introduce current research relating to MMPs as well as their native and synthetic inhibitor, with particular emphasis on the molecular aspects of their roles in tumor metastasis.

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β_1 in Cultured Human RPE Cells

In order to investigate the effects of TGF-β1 on the expression of MMP-2, -9 and TIMP- 1 in human retinal pigment epithelial （RPE） cells, the third-sixth passage cultured RPE cells were treated with TGF-β1 at different concentrations （0.01, 0. 1, 1.0, 10 ng/mL）, the expression of MMP-2, -9 and TIMP-1 mRNA was detected by semi-qudntitative RT-PCR assays. MMP-2, -9 and TIMP-1 mRNA were expressed in the cultured RPE cells. The values of MMP-2/β-actin in the cells treated with 0.1, 1.0, 10 ng/mL TGF-β1 were 1.04±0.04, 1.07±0.02 and 1.11±0.03, respectively, significantly higher than in the control group （0.96±0.03, P〈0. 05-0.01）. The expression of MMP-2 mRNA could be up-regulated by TGF-β, , in a dose-dependent manner. The expression of MMP-9 mRNA in the cultured RPE cells was slightly up-regulated by various TGF-β1 concentrations treatment. The values of TIMP-1/β-actin in the cells treated with 0.01 and 0.1 ng/ mL TGF-β1 were 0.85 ±0.01 and 0.97 ± 0.02 respectively, significantly lower than in the control group （1.07±0.04, P〈0.01）, indicating that the expression of TIMP-1 mRNA was down-regulated by TGF-β1 at low concentrations. But along with the increase of TGF-β1 concentrations （1.0 and 10 ng/mL）, the expression of TIMP-1 mRNA was slightly up-regulated, not significantly different from that in the control group （P〉0.05）. It was concluded that TGF-β1 might play an important role in the up-regulation of the expression of MMP-2 in RPE cells and result in a directional shift in the balance between MMP and TIMP. This may be facilitated for RPE cells to migrate in the pathogenesis of vitreoretinopathy.

Effects of (-)-epigallocatechin-3-gallate on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in fibroblasts irradiated with ultraviolet A

Background It is known that ultraviolet irradiation can affect cellular function through a number of signaling pathways ( ) epigallocatechin 3 gallate (EGCG) is the major effective component in green tea and can offer protection from ultraviolet induced damage In this study, we investigated the protective mechanism of EGCG on human dermal fibroblasts damaged by ultraviolet A (UVA) in vitro Methods Transcription factor Jun protein levels were measured by Western blot Matrix metalloproteinase 1 (MMP 1) and tissue inhibitor of metalloproteinase 1 (TIMP 1) mRNA were studied by reverse transcription polymerase chain reaction (RT PCR) analysis in conjunction with computer assisted image analysis MMP 1 and TIMP 1 proteins were quantified by enzyme linked immunosorbent assay (ELISA) Results EGCG decreased transcription activity of Jun protein after induction by UVA Both the mRNA and protein levels of MMP 1 were increased by UVA irradiation, while no significant changes were observed in TIMP 1 levels The ratio of MMP 1 to TIMP 1 showed statistically significant differences compared with the control EGCG decreased the ratio of MMP 1 to TIMP 1 by inhibiting UVA induced MMP 1 expression ( P <0 05) Conclusion EGCG can protect human fibroblasts against UVA damage by downregulating the transcription activity of Jun protein and the expression of MMP 1 The ratio of MMP 1 to TIMP 1, rather than the levels of MMP 1 or TIMP 1 alone, may play a significant role in human skin photodamage

Effect of shRNA Inhibiting HIF1α Gene on TIMP1 Expression in RPE Cells

Small hairpin RNA （shRNA） was used to silence the HIF1α 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 HIF1α mRNA sequence was synthesized by a method of in vitro transcription, and the HIF1α was interfered in RPE cultured under hypoxia （induced by 150 μmol/L CoCl2 ）. RT-PCR was employed to detect the expression of HIF1α and TIMP1. The expression levels of HIF1α and TIMP1 were measured by using Western blotting. The results showed that after the RPE were transfected with specific shRNA against HIF1α mRNA, RT PCR revealed that under hypoxia, the efficacy of HIF1α gene silencing in RPE was 83.4 %. Western blotting revealed that the expression levels of HIF1α 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 HIF1α mRNA could effectively silence the HIF1α gene, subsequently effectively inhibit the hypoxia-induced up-regulation of TIMP1.