亚甲基蓝下调转铁蛋白减轻创伤性脑损伤后神经细胞铁死亡

Methylene blue alleviates neuronal ferroptosis by down-regulating transferrin after traumatic brain injury

目的探讨亚甲基蓝(MB)对创伤性脑损伤(TBI)后神经细胞铁死亡的影响以及相关的分子机制。方法培养海马神经元HT22细胞系,随机分为空白对照组(Con组)、损伤模型组(Model组)和亚甲基蓝治疗组(MB组)。使用离体细胞TBI模型,对MB组和Model组进行划伤6 h处理,在恢复正常培养液条件后添加2μmol/L的MB培养48 h后取材。采用CCK-8法来检测细胞的活力及试剂盒检测细胞铁死亡标志物IL-18、IL-1β和Fe^(2+)含量;利用荧光免疫组化法检测转铁蛋白(Tf)的表达情况;使用Western blotting检测Tf的表达水平变化。结果与Con组比较,Model组HT22细胞活力显著降低,IL-18、IL-1β和Fe^(2+)含量显著增加,Tf蛋白表达升高,差异均有统计学意义(P<0.05);与Model组比较,MB组细胞活力升高,IL-18、IL-1β以及Fe^(2+)含量显著降低,Tf表达降低,且分布于胞浆和胞膜的Tf染色阳性率也明显降低,差异均有统计学意义(P<0.05)。结论MB通过调控Tf表达干预铁死亡相关分子,减轻TBI诱导的海马神经元损伤,抑制神经元铁死亡,发挥治疗TBI的重要作用。

Objective To investigate the effects of methylene blue(MB)on iron-mediated cell death in neuronal cells following traumatic brain injury(TBI)and the underlying molecular mechanisms.Methods Hippocampal neuronal HT22 cell line was cultured and randomly divided into blank control group(Con group),injury model group(Model group),and MB treatment group(MB group).In vitro TBI model was used,MB group and Model group were scratched for 6 h,and then cultured for 48 h in normal culture medium supplemented with 2μmol/L MB.Cell viability was detected using CCK-8 assay,and the levels of iron death markers IL-18,IL-1β,and Fe^(2+)were measured using specific kits.The expression of transferrin(Tf)was examined using fluorescence immunohistochemistry,and the change of Tf expression level was measured by Western blotting.Results Compared with Con group,HT22 cell viability was significantly decreased,the levels of IL-18,IL-1β,and Fe^(2+)were significantly increased,and Tf protein expression was increased in Model group,with statistical significance(P<0.05).In comparison with Model group,MB group exhibited increased cell viability,decreased levels of IL-18,IL-1β,and Fe^(2+),and decreased expression of Tf protein,as well as a significant reduction in Tf staining positivity in cytoplasm and cell membrane,with statistical significance(P<0.05).Conclusion MB interferes with iron death-related molecules by regulating Tf expression,alleviates TBI-induced hippocampal neuronal damage,inhibits neuronal ferroptosis,and plays an important role in the treatment of TBI.