苯甲酸钠通过苯甲酰化诱导胰腺炎症和β细胞凋亡

Sodium benzoate induces pancreatic inflammation and β-cell apoptosis via benzoylation modification

目的探讨食品添加剂苯甲酸钠(NAB)是否通过苯甲酰化(Kbz)修饰途径诱导胰腺炎症和β细胞凋亡。方法体内实验:C57BL/6J雄性小鼠(8周龄、18~20 g)分为正常对照组(双蒸水饲喂)、NAB喂水组(1 g/kg NAB溶液饲喂), 检测血糖, 20周后处死, ELISA法检测空腹血清胰岛素、白细胞介素(IL)-18、IL-1β和苯甲酰辅酶A水平, 胰腺免疫组化检测Bax、IL-18、泛苯甲酰化(Pan-Kbz)和泛乙酰化(Pan-Kac)。体外实验:培养β-TC-6细胞, NAB(6 mmol/L)或苯甲酰辅酶A(100 μmol/L)作为刺激因子, 以酰基转移酶P300抑制剂A485(10 μmol/L)作为干预因子, 24 h后行qRT-PCR、ELISA和Western blotting检测细胞炎症、凋亡、胰岛素分泌和Pan-Kbz水平。结果体内实验中, 与正常对照组相比, NAB组小鼠糖耐量受损、空腹胰岛素水平降低, 血清苯甲酰辅酶A浓度明显升高, 胰腺IL-1β、IL-18、Bax蛋白表达相对增高, Pan-Kbz水平升高, 而Pan-Kac水平下调(均P<0.05)。体外实验中, NAB浓度依赖性抑制胰岛素分泌, 促进Pan-Kbz和炎症因子IL-18、肿瘤坏死因子(TNF)-α释放, 抑制Bcl-2表达、上调Bax表达。A485逆转NAB诱导的Pan-Kbz修饰, 改善NAB诱导的炎症和凋亡, 促进胰岛素分泌(均P<0.05)。结论 NAB可能通过Kbz修饰途径诱导胰腺炎症、β细胞凋亡并损害胰岛素分泌功能。

Objective To explore whether the food additive sodium benzoate(NAB)induces pancreatic inflammation andβcell apoptosis through the benzoylation(Kbz)modification pathway.Methods In vivo experiments:C57BL/6J male mice(8 weeks old,18-20 g)were randomly divided into normal control group(double distilled water feeding)and NAB feeding group(1 g/kg NAB feeding).Blood glucose were measured.After 20 weeks,fasting serum insulin,interleukin(IL)-18,IL-1β,and benzoyl-CoA levels were detected by ELISA method.Bax,IL-18,Pan-Kbz and Pan-Kac were detected by immunohistochemistry staining.In vitro experiments:β-TC-6 cells were cultured with NAB(6 mmol/L)or benzoyl-CoA(100μmol/L)as stimulator and acyltransferase P300 inhibitor A485(10μmol/L)as intervention factor.24 hours later,inflammation,apoptosis,insulin secretion and Pan-Kbz level were detected by qRT-PCR,ELISA and Western blotting.Results In the in vivo experiments,compared to the NC group,mice in the NAB group exhibited impaired glucose tolerance,decreased fasting insulin levels,significantly increased serum benzoyl coenzyme A concentrations,relatively elevated pancreatic IL-1β,IL-18,and Bax protein expressions,increased levels of Pan-Kbz,while Pan-Kac levels were downregulated(all P<0.05);In vitro experiments,NAB dose-dependently inhibited insulin secretion,promoted the release of Pan-Kbz and inflammatory factors IL-18 and TNF-α,inhibited Bcl-2 expression and up-regulated Bax expression,A485 reversed NAB-induced Pan-Kbz modification,improved NAB-induced inflammation and apoptosis,and promoted insulin secretion(all P<0.05).Conclusion NAB may induce pancreatic inflammation,β-cell apoptosis,and impair insulin secretion through Kbz modification pathway.