Akkermansia muciniphila对慢性肾脏病大鼠肾功能的影响及机制

Effects of Akkermansia muciniphila on renal function in rats with chronic kidney disease and its mechanism

目的探索Akkermansia muciniphila(A.muciniphila)对慢性肾脏病(chronic kidney disease,CKD)肾功能的改善作用及其可能的机制。方法培养并储备A.muciniphila菌株;CKD鼠模型制备:使用腺嘌呤,200mg/kg,1次/d,灌胃4周;分组:将33只SD雄性大鼠随机分为对照组(n=7)、模型组(n=7)、预防组(n=10)和治疗组(n=9);分别测定各组大鼠的血尿素氮(BUN)、血肌酐(Scr)水平,评估肾功能;采用糖原染色(PAS)和马松三色染色(MTS)观察肾小管基底膜厚度和肾间质纤维化的改变;采用免疫组化和蛋白印迹法(Western blotting)测定肾脏组织中抗炎因子IL-10和促炎因子IL-1β、TNF-α的表达;进行统计学分析。结果成功建立了CKD动物模型。与对照组大鼠相比,CKD模型组的BUN、Scr水平显著升高(F=74.9890、80.2800,均P<0.01);与模型组大鼠相比,A.muciniphila预防组和治疗组的BUN、Scr水平显著降低(F=74.9890、80.2800,均P<0.01)。与对照组大鼠相比,CKD模型组出现了明显的肾脏病理组织损害:肾小管基底膜明显增厚,肾间质出现明显纤维化(F=15.9040、6.5330,均P<0.01);与CKD模型组大鼠相比,A.muciniphila预防组和治疗组肾脏病理组织有明显改善,肾小管基底膜增厚、肾间质纤维化明显减轻,其中预防组更明显(F=15.9040、6.5330,均P<0.05)。与对照组大鼠相比,CKD模型组肾脏组织中抗炎因子IL-10的表达明显降低,促炎因子IL-1β、TNF-α的表达明显升高(F=14.8060、5.6350、5.7420,均P<0.05);与CKD模型组大鼠相比,A.muciniphila预防组和治疗组肾脏组织中抗炎症因子IL-10的表达明显升高,促炎因子IL-1β、TNF-α的表达明显降低(F=14.8060、5.6350、5.7420,均P<0.05)。结论A.muciniphila可能通过抑制慢性系统性微炎症从而改善慢性肾脏病大鼠的肾功能。

Objective To explore the effect of Akkermansia muciniphila(A.muciniphila)on renal function in rats with chronic kidney disease(CKD)and its possible mechanism.Methods A.muciniphila strains were cultured and CKD rat models were established.33male SD rats were randomly divided into four groups and gavaged respectively with 0.9%NaCl(control group,n=7),adenine(model group,n=7),adenine and A.muciniphila simultaneously(prevention group,n=10)or adenine followed by A.muciniphila(treatment group,n=9).Blood urea nitrogen(BUN)and serum creatinine(Scr)in each group were measured and renal function was evaluated.The changes of renal tubule basement membrane thickness and renal interstitial fibrosis were observed using Glycogen(PAS)staining and Masson′s trichrome staining(MTS);the expression of anti-inflammatory factor IL-10and pro-inflammatory factors IL-1βand TNF-αin kidney tissue were determined with immunohistochemistry and Western blotting.Results Compared with the control group,the BUN and Scr in the model group significantly increased(F=74.9890,F=80.2800,all P<0.01).Compared with the model group,the values of BUN and Scr in the prevention group and treatment group significantly reduced(F=74.9890,F=80.2800,all P<0.01).Compared with the control group,the model group had obvious renal pathological tissue damage:the basement membrane of the renal tubules obviously thickened,with obvious renal interstitial fibrosis(F=15.9040,F=6.5330,all P<0.05).Compared with the CKD model group,A.muciniphila prevention group and treatment group had significant improvement in renal pathological tissues,the renal tubule basement membrane thickened and inter-renal fibrosis significantly reduced,especially in the prevention group(F=15.9040,F=6.5330,all P<0.05).Compared with the control group,the expression of anti-inflammatory factor IL-10in the kidney tissue in the model group significantly reduced,and that of pro-inflammatory factors IL-1βand TNF-αsignificantly increased(F=14.8060,F=5.6350,F=5.7420,all P<0.05).Compared with the model group,the expression of IL-10in the kidney tissues in the prevention group and treatment group significantly increased,and that of IL-1βand TNF-αsignificantly reduced(F=14.8060,F=5.6350,F=5.7420,all P<0.05).Conclusion A.muciniphila may improve renal function in rats with chronic kidney disease by inhibiting chronic systemic microinflammation.