黄蜀葵花总黄酮对肾脏葡萄糖重吸收影响的实验研究

Effect of total flavones of Abelmoschus manihot on renal glucose reabsorption in mice

目的探讨黄蜀葵花总黄酮(TFA)对肾小管葡萄糖重吸收的影响。方法24只C57BL/6小鼠按照随机数字表法分成3组:对照组、高脂喂养组(HFD)组及HFD+TFA组,每组8只。体外采用人近端小管上皮HK2细胞,棕榈酸(PA)处理模拟脂毒,并予TFA干预,分别为对照组、PA组及PA+TFA组。油红O染色评估肾皮质组织及胞内脂质含量,免疫荧光染色、实时荧光定量聚合酶链反应(qRT-PCR)及Western blotting检测钠-葡萄糖共转运蛋白2(SGLT2)表达,并评估各组细胞葡萄糖摄取能力。组间比较采用单因素方差分析。结果HFD组小鼠肾小管中脂质沉积明显,而对照组小鼠肾小管中未观察到脂滴。与HFD组相比,HFD+TFA组小鼠肾小管中红染脂滴明显减少(P<0.001)。免疫荧光结果显示,3组小鼠肾小管均表达SGLT2,HFD组及HFD+TFA组小鼠SGLT2蛋白表达水平高于对照组(P<0.05)。然而,HFD+TFA组SGLT2蛋白表达水平较HFD组小鼠明显减弱(P=0.049)。qRT-PCR结果显示,HFD组小鼠SGLT2 mRNA表达水平明显高于对照组(P<0.001),而TFA干预后SGLT2 mRNA表达水平减弱。细胞实验观察到,TFA可显著减轻PA对细胞的毒性,缓解胞内脂质沉积,减弱SGLT2表达,并抑制细胞葡萄糖摄取能力(P<0.05)。结论TFA减轻肾小管脂质沉积,改善葡萄糖重吸收功能,其肾脏保护效应可能与介导SGLT2调控肾小管葡萄糖重吸收有关。

Objective To explore the effect of total flavones of Abelmoschus manihot(TFA)on renal glucose reabsorption.Methods A total of 24 C57BL/6 mice were assigned to control,high fat diet(HFD),and HFD+TFA groups using random number table method,8 mice in each group.In vitro,HK2 cells were treated with palmitic acid(PA).The cells were divided into 3 groups:control group,PA group,and PA+TFA group.Oil red O staining was used to evaluate lipid accumulation.Immunofluorescence staining,quantitative real-time polymerase chain reaction(qRT-PCR),and Western blotting were used to evaluate glucose uptake and sodium glucose cotransporter 2(SGLT2)expression.One-way analysis of variance(ANOVA)was used for comparison among groups.Results Massive lipid deposition in renal tubules was observed in HFD group,whereas no lipid deposition was found in the control group.Compared with HFD group,red-stained lipid droplets were significantly decreased in HFD+TFA group(P<0.001).The immunofluorescence results showed that SGLT2 protein in renal cortex tissue was dectected in three groups.Compared with the control group,SGLT2 expressions were significantly increased in HFD group and HFD+TFA group(P<0.05).However,SGLT2 expression in HFD+TFA group was lower than HFD group(P=0.049).The qRT-PCR results showed that SGLT2 mRNA in HFD group was significantly higher than that in the control group(P<0.001),while decreased after TFA intervention.In addition,treatment with TFA resulted in significant amelioration of lipid accumulation induced by PA in HK2 cells.Accompanied with improvement of lipid deposition,SGLT2 expression and glucose uptake were attenuated(P<0.05).Conclusions TFA can ameliorate renal lipid deposition,thereby inhibiting glucose reabsorption.Its renal protective effect may be related to its role in inhibiting SGLT2 expression.