雷公藤多苷片调控lncRNA XIST/miR-217轴介导TLR4/NF-κB通路改善特发性膜性肾病大鼠肾损伤的作用机制OA

Objective To investigate the mechanism of Tripterygium Glycosides Tablets in ameliorating renal injury in rats with idiopathic membranous nephropathy(IMN)by regulating the long non-coding RNA X inactive-specific transcript(lncRNA XIST)/microRNA-217(miR-217)axis-mediated Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)signaling pathway.Methods The IMN rat model was established by a single tail vein injection of sheep anti-rat Fx1A serum.Twenty-seven successfully modeled rats were randomly divided into a model group,a Tripterygium Glycosides Tablets group(6.25 mg·kg-1),and a benazepril group(10 mg·kg-1),with 9 rats in each group;another 6 rats served as the blank group.Rats in each treatment group were intragastrically administered the corresponding drug,while those in the blank and model groups received an equal volume of distilled water by gavage once daily for 6 consecutive weeks.After 6 weeks of intervention,urine,serum,and renal tissues were collected.Serum levels of blood urea nitrogen(BUN),serum creatinine(Scr),total cholesterol(TC),triglycerides(TG),albumin(Alb),and 24-hour urinary protein(24 h-UTP)were measured using an automatic biochemical analyzer.Renal histopathological changes were observed by HE and PASM staining.Renal angiotensin Ⅱ(Ang-Ⅱ)level was detected by ELISA.The mRNA expression levels of lncRNA XIST,miR-217,TLR4,NF-κB p65,and Nephrin in renal tissue were determined by RT-qPCR.The protein expression levels of TLR4,NF-κB p65,and Nephrin were detected by Western Blot.Results(1)In the blank group,glomerular structures were intact,renal tubular epithelial cells were morphologically normal,no obvious inflammatory infiltration was observed,and no significant thickening of the glomerular capsular basement membrane,glomerular capillary basement membrane,or tubular epithelial basement membrane was found.In the model group,the glomerular mesangial area was markedly expanded,some podocytes were swollen with focal interstitial lymphocytic infiltration;the glomerular capsular basement membrane and glomerular capillary basement membrane were significantly thickened,with occasional thickening of the tubular epithelial basement membrane.Renal histopathology was markedly improved in both the Tripterygium Glycosides Tablets group and the benazepril group,showing mild expansion of a small number of glomerular mesangial areas,mild thickening of the glomerular capsular basement membrane,mild thickening of the glomerular capillary basement membrane in some glomeruli,and occasional thickening of the tubular epithelial basement membrane.(2)There were no significant differences in body weight or urine volume among groups after treatment(P＞0.05).Compared with the blank group,the model group showed increased 24 h-UTP,serum BUN,Scr,TC,TG,and renal Ang-Ⅱ expression(P＜0.01),and decreased serum Alb level(P＜0.01).Compared with the model group,both the Tripterygium Glycosides Tablets group and the benazepril group showed decreased 24 h-UTP,serum BUN,Scr,TC,TG,and renal Ang-Ⅱexpression(P＜0.01),and increased serum Alb level(P＜0.01).(3)Compared with the blank group,the model group showed increased lncRNA XIST,mRNA and protein expression of TLR4 and NF-κB p65(P＜0.01),and decreased miR-217 and mRNA and protein expression of Nephrin(P＜0.01).Compared with the model group,both the Tripterygium Glycosides Tablets group and the benazepril group showed decreased lncRNA XIST,mRNA and protein expression of TLR4 and NF-κB p65,and increased miR-217 and mRNA and protein expression of Nephrin(P＜0.01).Conclusion Tripterygium Glycosides Tablets may exert renoprotective effects in IMN rats by inhibiting the activation of the lncRNA XIST/miR-217 axis and inhibiting activation of the TLR4/NF-κB pathway mediated by this axis,reducing inflammatory factor release,alleviating podocyte injury,and improving renal histopathological damage.