丁酸盐对糖尿病肾病小鼠肾损伤的保护作用及机制

Protective effect of butyrate on renal injury in diabetic nephropathy mice and its mechanism

目的:探讨丁酸盐对2型糖尿病肾病(DN)小鼠肾损伤的保护作用及其机制。方法:将雄性db/db小鼠随机分为模型组(DN)、丁酸钠500 mg/(kg·d)组(NaB1)和丁酸钠1000 mg/(kg·d)组(NaB2),同周龄雄性db/m作为对照组(NC)。NaB1组和NaB2组每日丁酸钠溶液灌胃,NC组和DN组予等体积0.9%氯化钠溶液,连续灌胃8周后处死小鼠。留取肾组织进行苏木素伊红(HE)染色和过碘酸-希夫(PAS)染色;分别提取肾组织mRNA和蛋白进行实时荧光定量聚合酶链反应(RT-qPCR)和蛋白质印迹(Western blot)检测;采用相关试剂盒检测尿肌酐、尿微量白蛋白(m ALB)、肾组织白细胞介素-6(IL-6)、血肌酐(SCr)等相关指标。结果:与NC组小鼠比,DN组小鼠精神萎靡,多饮多食多尿症状明显,体质量、血糖显著升高、尿白蛋白/肌酐比值(UACR)明显增高(P<0.05)。丁酸钠治疗8周后,小鼠精神饮食状况改善,血糖、UACR下降、肾组织IL-6水平下降,GLP-1R、AMPK、PGC-1α、MFN2和OPA1 mRNA表达增加(P<0.05)。结论:丁酸钠通过调节DN小鼠的AMPK和GLP-1R发挥肾脏保护作用。

Objective:To investigate the protective effect of butyrate on renal injury in mice with type 2diabetic nephropathy and to explore its mechanism.Methods:Male db/db mice were randomly divided into model group(DN),sodium butyrate 500 mg·kg-1·d-1 group(NaB1)and sodium butyrate 1000 mg·kg-1·d-1 group(NaB2).The db/m mice with the same weeks served as the control group(NC).NaB1 and NaB2 groups were given sodium butyrate solution every day,while NC group and DN group were perfused with equal volume of physiological saline.After 8 weeks for intragastric administration,the mice were sacrificed.Kidney tissue was preserved for staining of hematoxylin eosin(HE)and periodic acid-Schiff(PAS);meanwhile extracting the mRNA and protein for real-time quantitative polymerase chain reaction(RT-qPCR)and western blotting;using relevant kits to detect urine creatinine,urine microalbumin(mALB),interleukin-6(IL-6)of renal tissue,serum creatinine(SCr)and other related indicators.Results:Compared with the NC group,the DN group presented listlessness,more polydipsia and polyuria,expressed significantly higher body weight and blood glucose(P<0.05),and increased the ratio of urinary protein and creatinine(UACR)(P<0.05).After the treatment of sodium butyrate for 8 weeks,the mice had better mental conditions and diet,lower blood glucose and UACR(P<0.05)and lower IL-6 levels of renal tissue,but higher expressions of GLP-1R,AMPK,PGC-1α,MFN2 and OPA1 mRNA(P<0.05).Conclusion:Sodium butyrate exerts reno-protective effect by regulating AMPK and GLP-1R in diabetic nephropathy mice.