非对称二甲基精氨酸在氧化低密度脂蛋白诱导基质金属蛋白酶2蛋白表达中的作用及机制

目的初步探讨非对称二甲基精氨酸(ADMA)在氧化低密度脂蛋白(ox-LDL)诱导基质金属蛋白酶2(MMP-2)蛋白表达中的作用及可能机制。方法观察ox-LDL对内皮细胞的损伤作用和MMPs抑制剂多西环素对ox-LDL诱导的内皮细胞MMP-2蛋白表达及ADMA水平的影响;观察ADMA对内皮细胞MMP-2蛋白表达及内皮细胞活性氧(ROS)水平的影响。结果(1)ox-LDL降低内皮细胞生存率呈浓度和时间依赖性;(2)多西环素能明显抑制ox-L,DL诱导的细胞生存率的降低,并显著降低ox-LDL(50 mg/L)诱导的ADMA水平与MMP-2蛋白表达的升高(多西环素5μg/ml时P<0.05,多西环素10,20μg/ml时P<0.01);(3)ADMA降低内皮细胞生存率呈浓度依赖性(P<0.01),并可升高内皮细胞ROS与MMP-2蛋白表达水平(ADMA 3μmol/L时P<0.05,ADMA 10,30μmol/L时P<0.01)。L精氨酸和细胞内抗氧化剂(PDTC)均能拮抗上述作用(P<0.01)。、结论ox-LDL诱导内皮细胞MMP-2蛋白表达水平升高可能涉及ADMA途径;多西环素对MMP-2蛋白表达的抑制作用可能与降低ADMA水平有关;ADMA可能通过诱导氧化应激增加MMP-2蛋白表达。

The effects of ADMA on the process of ox-LDL-induced MMP-2 expression and the potential mechanism

Objective To investigate the effects of ADMA on ox-LDL-induced MMP-2 expression in endothelial cells and explore the potential mechanisms. Methods To investigate the dose-effect and the time-effect of ox-LDL on endothelial cells injury. To investigate the effects of doxeyeline on ox-LDL- induced MMP-2 expression and ADMA level. To investigate the effects of ADMA on MMP-2 expression and reactive oxygen species （ROS） level in endothelial cells, as well as the counteraction of intracellular antioxidant PDTC （30 μmol/L） and NOS substrate L-Arginine （0. 5 mmol/L）. Results （1） Ox-LDL induced endothelial cell injury was in a time- and dose- dependent manner. （2） Doxycycline significantly attenuated ox-LDL-induced decrease of endothelial cells viability and increased MMP-2 expression and ADMA level （when the coneentration of Doxyeycline was 5 μg/ml P 〈 0. 05, when the eoneentration of Doxycyeline was 10, 20 μg/ml P 〈0. 01 ）. （3） ADMA decreased endothelial cell viability（ P 〈 0. 01 ）in a dose-dependent manner and increased ROS level and MMP-2 expression （when the concentration of ADMA was 3 μmol/L P 〈 0. 05, when the concentration of ADMA was 10, 30 μmol/L P 〈 0. 01 ） which can be completely prohibited by either L-Arginine or PDTC （ P 〈 0. 01 ）. Conclusions ADMA might be involved in the ox-LDL-induced increase of MMP-2 expression in endothelial cells. The inhibition of MMP-2 expression by Doxycyline may be related to the decrease of ADMA. The effect of ADMA on MMP- 2 expression may be related to oxidative stress.