目的：探讨神经酰胺类似蛋白(CERKL)是否通过激活沉默信息调节因子1(SIRT1)/E2F转录因子1(E2F1)轴减轻蓝光导致的视网膜色素上皮(RPE)细胞氧化应激损伤。

方法：培养人视网膜色素上皮-19(ARPE-19)细胞，蓝光照射后观察细胞形态变化，PCR与蛋白免疫印迹法测定细胞CERKL的表达情况； 分别采用siRNA-CERKL与pcDNA3.1-CERKL转染ARPE-19细胞，蓝光暴露处理后，采用MTT法测定细胞活力，TUNEL法检测细胞凋亡情况，分析氧化应激标志物的含量与SIRT1/E2F1轴的表达情况； 随后转染siRNA-SIRT1至ARPE-19细胞，再次测定蓝光照射下细胞氧化应激损伤状况。

结果：蓝光照射后，ARPE-19细胞逐渐收缩成圆球状，且出现空泡； 蓝光照射导致CERKL表达水平升高(P<0.05)，同时观察到细胞活力降低(P<0.05)，凋亡率升高(P<0.05)，活性氧、丙二醛与8-羟基脱氧鸟苷含量升高(P<0.05)； 沉默CERKL会加剧此现象，而上调CERKL则能缓解此变化(P<0.05)； 上调CERKL同时激活了SIRT1表达，促进了E2F1的脱乙酰化(P<0.05)，而沉默SIRT1能逆转上调CERKL对蓝光导致ARPE-19细胞氧化应激损伤的缓解作用(P<0.05)。

结论：CERKL通过激活SIRT1表达，促进E2F1脱乙酰化，从而减轻蓝光诱发的ARPE-19细胞氧化应激损伤。

METHODS:Cultured human retinal pigment epithelial-19(ARPE-19)cells were irradiated with blue light to observe the morphological changes, and the expression of CERKL was detected by PCR and Western blot. ARPE-19 cells were transfected with siRNA-CERKL and pcDNA3.1-CERKL respectively. After exposure to blue light, cell viability was determined by MTT assay, apoptosis was detected by TUNEL assay, content of oxidative stress markers and the expression of SIRT1/E2F1 axis was analyzed. Then siRNA-SIRT1 was transfected into ARPE-19 cells, and the oxidative stress damage of ARPE-19 cells under blue light irradiation was detected again.

RESULTS:ARPE-19 cells gradually contracted into spheres and appeared vacuoles after exposure to blue light. Blue light irradiation led to the increase of CERKL expression level(P<0.05), meanwhile, the rate of cell viability was decreased(P<0.05), the rate of the apoptosis was increased(P<0.05), contents of reactive oxygen species, malondialdehyde and 8-hydroxydeoxyguanosine were increased(P<0.05). Silence of CERKL aggravated this phenomenon, while up-regulation of CERKL could alleviate this change(P<0.05). Up-regulation of CERKL also activated the expression of SIRT1 and promoted the deacetylation of E2F1(P<0.05). Silencing SIRT1 could reverse the alleviating effect of up-regulating CERKL on oxidative stress injury of ARPE-19 cells induced by blue light(P<0.05).

CONCLUSION: CERKL can reduce oxidative stress damage of ARPE-19 cells induced by blue light via activating SIRT1 expression and promoting the deacetylation of E2F1.