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本文旨在研究内质网应激(endoplasmic reticulum stress, ERS)感受器活化转录因子6 (activating transcription factor 6, ATF6)是否介导晚期糖基化白蛋白(advanced glycated albumin, AGE-alb)所诱导的巨噬细胞凋亡，并阐明其可能的分子机制。体外培养RAW264.7巨噬细胞，给予AGE-alb (2、4和6 g/L)处理24 h，以正常白蛋白和ERS诱导剂衣霉素(tunicamycin, TM)处理24 h的巨噬细胞分别作为阴性和阳性对照组，并采用小干扰RNA (small interfering RNA, siRNA)技术沉默ATF6表达。分别采用MTT法和Annexin V-FITC/碘化丙碇双染法检测细胞活力和凋亡情况；试剂盒测定培养基乳酸脱氢酶(lactate dehydrogenase, LDH)和细胞内caspase-3活性；免疫荧光细胞化学法检测ATF6核转位情况；Western blot法检测ATF6和促凋亡蛋白C/EBP同源蛋白(C/EBP homologous protein, CHOP)蛋白表达变化，实时荧光定量聚合酶链反应法检测CHOP mRNA表达变化。结果显示：与TM相似，AGE-alb在蛋白和mRNA水平均显著上调ERS凋亡途径关键分子CHOP表达，该作用呈浓度依赖性；Western blot和免疫荧光细胞化学法均显示AGE-alb处理细胞后ATF6明显由胞浆向细胞核内转移；采用siRNA技术沉默ATF6则明显减轻AGE-alb所致的细胞活力降低、LDH漏出、凋亡率增加及caspase-3活化，并可抑制AGE-alb所诱导的CHOP表达上调。上述结果表明，ATF6及其下游分子CHOP介导AGE-alb所诱导的巨噬细胞凋亡。
This study aimed to investigate whether the activation transcription factor 6 (ATF6) of endoplasmic reticulum stress (ERS) mediates the induction of advanced glycated albumin (AGE-alb) Macrophage apoptosis, and clarify its possible molecular mechanism. RAW264.7 macrophages were cultured in vitro and treated with AGE-alb (2, 4 and 6 g / L) for 24 h. Normal macrophages and tunicamycin (TM), an ERS inducer, Respectively, as negative and positive control group, and silencing ATF6 expression using small interfering RNA (siRNA). Cell viability and apoptosis were detected by MTT assay and Annexin V-FITC / propidium iodide double staining respectively. The activity of lactate dehydrogenase (LDH) and intracellular caspase-3 The nuclear translocation of ATF6 was detected by cytochemistry, the protein expression of ATF6 and C / EBP homologous protein (CHOP) was detected by Western blot, and the expression of CHOP mRNA was detected by real-time fluorescence quantitative polymerase chain reaction Change of expression The results showed that, similar to TM, AGE-alb significantly up-regulated CHOP expression in the ERS apoptotic pathway at a protein and mRNA level in a concentration-dependent manner. Western blot and immunofluorescence cytochemistry showed that AGE-alb ATF6 obviously translocated from the cytoplasm to the nucleus; silencing ATF6 by siRNA significantly reduced cell viability, LDH leakage, apoptosis rate and caspase-3 activation induced by AGE-alb and inhibited AGE-alb-induced CHOP expression is up-regulated. The above results show that ATF6 and its downstream molecule CHOP mediated AGE-alb induced apoptosis of macrophages.