无镍不锈钢金属支架材料对血管内皮细胞凋亡的诱导机制

Mechanisms of Nickel-free Stainless Steel Induced Apoptosis in Vascular Endothelial Cells

目的研究高氮无镍不锈钢(HNNF SS)材料对血管内皮细胞凋亡的影响。方法应用Annexin V.FITC/PI染色和流式细胞分析术检测贴附于HNNF SS和对照组316L不锈钢(316L SS)材料表面的人脐带静脉内皮细胞(HUVECs)的凋亡水平;实时定量PCR检测凋亡相关基因和microRNA(miRNA)的表达水平。结果流式细胞结果表明316L SS比HNNF SS能更有效地激活细胞凋亡(P<0.05),生长在316L SS上的HUVECs中Fas、Caspase.3和Caspase.8基因过表达,2种材料上生长的HUVECs中miR.133a、186、210、34a和124含量高于空白对照组(P<0.05)。结论316L SS激活细胞凋亡的机制可能与镍离子激活Fas.Caspase.8.Caspase.3外源性凋亡通路相关,此信号通路也受miRNA调节,实时定量PCR检测结果显示了相关基因及miRNA的表达差异。提示HNNF SS在避免细胞凋亡,减缓支架植入再狭窄方面优于16L SS材料。

Objective To investigate the effects of high nitrogen nickel-free austenitic stainless steel （HNNF SS） on the apoptosis induction of vascular endothelial cells and develop a novel biomaterial for circumventing the in-stentt restenosis. Methods Human umbilical vein endothelial cells （HUVECs） were growed on the HNNF SS and general 316L stainless steel （316L SS）. Annexin V-F1TC and Propidium Iodide were employed to detect the apoptosis by flow cytometric analysis. The expression of apoptosis-related genes and microRNA were also examined by quantitative real- time PCR （qRT-PCR）. Results Flow cytometry analysis revealed that 316L SS could activate the cellular apoptosis more etticiently than HNNF SS （ P〈 0.05 ）. At the molecular level, qRT-PCR results showed that the cell apoptosis related genes were overexpressed on 316L SS （ P〈 0.05 ）, including Fas, Caspase-3, and Caspase-8. The overexpression of miR-133a, 186,210,34a and 124 was also observed in HUVECs growing on the 316L SS and HNNF SS materials （P 〈 0.05 ）. Conclusion The mechanism of 316L SS triggering cell apoptosis might be related to the releasing nickel inducing cell apoptosis via Fas-Caspase-8-Caspase-3 exogenous pathway, which is modulated by altered microRNA expression ; the RT-PCR results also showed the expression variation of related genes and miRNA. Our results suggested that HNNF SS is better than the 316L SS material in the aspect of avoiding cell apeptosis and circumventing the in-tent restenosis.