γ-干扰素对平滑肌细胞增殖与凋亡及基质金属蛋白酶活性的影响

Studies of the Effects of Interferon-γ on Proliferation and Apotosis of Smooth Muscle Cells and Matrix Metalloproteinase Activity

目的 :通过研究γ 干扰素对平滑肌细胞增殖和凋亡以及对基质金属蛋白酶 (MMPs)活性的影响 ,了解其对粥样斑块稳定性的影响。 方法 :①大鼠血管平滑肌细胞体外培养 ,加入不同浓度的γ 干扰素 (10U/ml、10 0U/ml、2 0 0U/ml) ,四甲基偶氮唑唑 (MTT)方法检测细胞的增殖 ,流式细胞仪检测细胞的凋亡。②大鼠腹腔巨噬细胞培养 ,加入不同浓度的γ 干扰素 ,用以明胶为底物的聚丙烯酰胺凝胶电泳酶谱法测定上清液中MMPs的活性。 结果 :γ 干扰素可以抑制平滑肌细胞增殖 ,促进其凋亡 ,其作用随着浓度的增加而增强。γ 干扰素可使巨噬细胞产生的MMPs活性增强。 结论 :粥样斑块中γ 干扰素由活化的T淋巴细胞产生 ,可以通过减少斑块内平滑肌细胞数量和增加纤维帽中细胞外基质的降解增加粥样斑块的不稳定性。

Objective: Studying the effects of interferon-γ(INF-γ) on proliferation and apotosis of smooth muscle cells(SMCs) and matrix metalloproteinase(MMPs) activity and effect on plaque stability. Methods:①The smooth muscle cells from male Sprague-Dawley rat thoracic aorta were primary cultured in vitro in DMEM supplemented with 10% NCS.Different INF-γ concentrations (10 U/ml、100 U/ml、200 U/ml) were added into plate to be co-incubated with the cells, respectively. MTT method was used to detect the cell proliferation after 24, 48 and 72 hours. After different INF-γ concentrations were incubated with SMCs for 24 hours, the cell cycle was detected by flow cytometer to observe the effect of INF-γ on cell apoptosis. ②Macrophages were isolated from rat abdomen and allowed to grow in cell culture with different INF-γ concentrations (10 U/ml、100 U/ml、200 U/ml) .The supernatant of the macrophages cultures was collected 24 hour later. Zymography was performed by SDS-PAGE in 10% gels containing 0.1%(wt/vol) gelatin. After destained gelatinolytic activity was established by a clear white band against the blue background of stained gelatin. The activities of MMPs could be detected by the grey level of the band. Results:①INF-γ inhibitted the proliferation and accelerated apoptosis of SMCs with dose-dependence.②INF-γ increased the activity of MMPs significantly with dose-dependence. Conclusions: INF-γ in plaque is produced by active T cells. INF-γ can increase plaque instability by decreasing the amount of SMCs in plaques and increasing the degradation of extracellular matrix in fibrous cap.