NKX2-5基因启动子在急性心肌梗死患者中的遗传变异和初步功能分析

Genetic variations and preliminary functional analysis of the NKX2-5 gene promoter in patients with acute myocardial infarction

摘要:

目的]探讨同源盒蛋白NKX2-5基因启动子区的遗传变异与急性心肌梗死发病的相关性。 [方法]采用病例对照研究方法,收集415例急性心肌梗死患者和388例健康对照。利用聚合酶链反应和测序的方法获得NKX2-5基因启动子区的基因序列变异,通过细胞培养和转染对NKX2-5基因启动子区的基因序列变异进行生物学功能分析,利用TRANSFAC在线网站预测基因序列变异可能影响的转录因子结合位点。 [结果]在NKX2-5基因启动子区共发现8个基因序列变异,其中遗传变异g.173236217 C＞T、g.173236119 T＞A、g.173235502 A＞G和g.173235141 C＞T仅在心肌梗死患者中出现,遗传变异g.173236158 T＞C和g.173235283 G＞A仅在对照组中出现。转染结果显示,遗传变异g.173236119 T＞A和g.173235502 A＞G显著降低NKX2-5基因启动子转录活性(P＜0.01),但遗传变异g.173236158 T＞C和g.173235283 G＞A则增加了NKX2-5基因启动子转录活性(P＜0.05)。TRANSFAC分析发现遗传变异g.173235502 A＞G和g.173236158 T＞C影响NKX2-5基因启动子与转录因子的结合。 [结论]急性心肌梗死病人中NKX2-5基因启动子的遗传变异可能通过影响转录因子的结合,降低NKX2-5基因的转录活性,从而可能作为一种罕见的低频变异参与急性心肌梗死的发生发展。

Abstract:

Aim To investigate the association between genetic variations in the promoter region of the homeobox protein NKX25 gene and the onset of acute myocardial infarction (AMI). Methods A case-control study was conducted involving 415 AMI patients and 388 healthy controls. Gene sequence variations in the promoter region of the NKX2-5 gene were identified using polymerase chain reaction combined with sequencing. The biological functions of gene sequence variants in the NKX2-5 promoter region was analyzed through cell culture and cell transfection assays. Transcription factor binding sites potentially altered by gene sequence variations were predicted using the TRANSFAC online platform. Results A total of eight gene sequence variations were identified. Therein, genetic variants g.173236217 C＞T, g.173236119 T＞A, g.173235502 A＞G and g.173235141 C＞T were observed only in AMI patients, whereas genetic variants g.173236158 T＞C and g.173235283 G＞A were found only in the control group. Transfection experiments demonstrated that genetic variants g.173236119 T＞A and g.173235502 A＞G significantly reduced NKX2-5 gene promoter transcriptional activity (P＜0.01). In contrast, genetic variants g.173236158 T＞C and g.173235283 G＞A enhanced promoter activity (P＜0.05). TRANSFAC analysis indicated that genetic variants g.173235502 A＞G and g.173236158 T＞C altered transcription factor binding to the NKX2-5 promoter. Conclusion Genetic variations in the NKX2-5 gene promoter may contribute to AMI susceptibility by decreasing transcriptional activity through altered transcription factor binding, suggesting their potential role as rare, low-frequency variations in the AMI pathogenesis.