Influence of hydrogen sulfide on zymogen activation of homocysteineinduced matix metalloproteinase-2 in H9C2 cardiocytes

Objective: To observe the influence of different concentrations of homocysteine(Hcy) and hydrogen sulfide(H2S) on the secretion and activation of matix metalloproteinase-2(MMP-2) in cardiocytes so as to search for new ways to fight against myocardial tissue fibrosis. Methods: Cardiocytes H9C2 was cultured in vitro and different concentrations of Hcy and H2 S were added for 6-h and 24-h cultivation. MTT cell proliferation assay was applied to test the activation change of cardiocytes H9C2 after affecting by different concentrations of Hcy and H2 S. ELISA and MTT were employed to detect the expression and enzymatic activity of MMP-2. Results: The H9C2 cell inhibition of activity was more significant with 1 000 μmol/L of Hcy as compared with other concentrations(P<0.001). With 2.5-100.0 μmol/L Hcy and 0.1, 1.0 and 10.0 mmol/L H2 S, the activity of H9C2 did not change significantly(P>0.05). Hcy with concentrations of 10, 50 and 100 μmol/L could increase the quantity of MMP-2 secreted by cardiocytes H9C2, and the interaction strength was concentration-dependent(P<0.05). After interacting with 100 μmol/L of Hcy for 6 h, the zymogen activation effect of MMP-2 was stronger than that of the 2.5-25 μmol/L group(P<0.05). After interacting with Hcy and H2S(1.0 mmol/L) for 6 h and 24 h, the activation effect of MMP-2 was stronger than those interacted with 10, 25, 50 and 100 μmol/L of Hcy(P<0.05). Conclusions: Hcy can increase the production of MMP-2 secreted by H9C2 cell and improve its zymogen activation. Besides, the interaction strength is concentration-dependent; while H2 S can up-regulate the activation of MMP-2 and co-promote the activation of MMP-2 with Hcy as well.

Expressions of cyclooxygenase-2 and matrix metalloproteinase-9 in cervical carcinoma and their clinical significance

Objective: To investigate the expressions of cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-9 in cervical carcinoma and their clinical significance. Methods: Immunohistochemistry SP method was used to detect the expres- sions of COX-2 and MMP-9 in 72 cases of invasive carcinoma of cervix (ICC) and 16 cases of normal cervical epithelium remote from tumor (NCE). The relationships between the expressions of COX-2, MMP-9 in ICC and some characteristics relating to clinical pathology of cervical carcinoma such as histological grading, lymph node metastasis, stromal invasion and FIGO stage were analyzed statistically. Results: The rates of the positive expressions of COX-2 and MMP-9 in ICC were significantly higher than those in NCE. COX-2: 88.9% (64/72) in group ICC and 12.5% (2/16) in group NCE, P = 0.000; MMP-9: 94.4% (68/72) in group ICC and 43.8% (7/16) in group NCE, P = 0.000. The expression of COX-2 was positively correlated with lymph node metastasis (r = 0.296, P = 0.012) and stromal invasion (r = 0.257, P = 0.029). The expression of MMP-9 was positively correlated with FIGO stage (r = 0.329, P = 0.005) and histological grading (r = 0.351, P = 0.003). The expression of COX-2 was positively correlated with the expression of MMP-9 in ICC (r = 0.297, P = 0.011). Conclusion: The overexpressions of COX-2 and MMP-9 were closely related to the invasion and growth of cervical carcinoma. The tissue with the overexpression of COX-2 had strong invasion ability. COX-2 and MMP-9 had synergistic effect on proliferation, invasion and metastasis of cancer cells. Detecting the coexpression of COX-2 and MMP-9 may be of value in further understanding the biological behavior and predicting the prognosis of cervical carcinoma.

Expressions and clinical significances of MMP-2 and TIMP-2 mRNA in bladder transitional cell carcinomas

Objective:The aim of the study was to investigate the expressions of matrix metalloproteinase-2(MMP-2) and tissue inhibitor of MMP-2(TIMP-2) mRNA in transitional cell carcinomas of bladder and discuss their clinical significances.Methods:Using RT-PCR and real time quantitative PCR(RQ-PCR) technique,the expressions of MMP-2 and TIMP-2 mRNA of 45 cases of bladder carcinoma(tumor group) and 10 cases of normal bladder tissue(control group) were analyzed.Results:MMP-2 and TIMP-2 were not expressed in control group.MMP-2 was expressed in 30 cases tumor samples and TIMP-2 was expressed in 26 cases.The expression of MMP-2 mRNA in non-muscle invasive bladder cancers and grade I cancers was lower than that in muscle invasive bladder cancers and grades II-III cancers respectively.The differences were statistically significant(P<0.05).The expression of MMP-2 in recurrent patients was higher than that in incipient patients.TIMP-2 mRNA expression decreased with grades and stage.The expression of TIMP-2 in non-muscle invasive bladder cancers and grade I cancers was higher than that in muscle invasive bladder cancers and grades II-III cancers respectively.There was statistical difference between two groups(P < 0.05).TIMP-2 expression in incipient patients was higher than that in recurrent patients,but the difference was not significant(P>0.05).Conclusion:These results suggest that MMP-2 and TIMP-2 play an important role in the invasion step of transitional cell carcinoma of bladder.MMP-2 may become a new approach to the diagnosis of bladder carcinoma.

Effects of rosuvastatin on the production and activation of matrix metalloproteinase-2 and migration of cultured rat vascular smooth muscle cells induced by homocysteine

Objective： To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 （MMP-2） and tissue inhibitors of matrix metalloproteinase-2 （TIMP-2） and on cell migration of cultured rat vascular smooth muscle cells （VSMCs）. Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. Methods： Rat VSMCs were incubated with different concentrations of homocysteine （50-5000 μmol/L）. Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin （10^-9-10^-5 mol/L） were added when VSMCs were induced with 1 000 pmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. Results： Homocysteine （50-1000 μmol/L） increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5000 pmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and ac- tivation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine （50-5000 μmol/L） stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. Conclusions： Homocysteine （50-1000 μmol/L） significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease the excessive expression and acti- vation of MMP-2 and abnormal migration of VSMCs induced by homocysteine.