尿石素A激活自噬抑制含NLR家族Pyrin域蛋白3炎症信号改善糖尿病小鼠胰腺损伤研究

Urolithin A activated autophagy and suppressed containing NLR family Pyrin domain protein 3 inflammation signal to improve pancreatic damage in diabetic mice

目的探讨天然多酚尿石素A对糖尿病小鼠胰腺损伤的影响,初步探讨自噬和炎症机制。方法将c57BL/6小鼠按体重随机分为普通喂食的对照组,高脂喂食的模型组和实验组,同时实验组按50 mg·kg^-1剂量灌胃给予尿石素A,喂养6周后,腹腔注射链脲佐菌素建立2型糖尿病模型,继续给药8周。用苏木精-伊红染色观察胰腺病理结构的变化;用酶联免疫吸附法检测血浆炎症细胞因子水平;用蛋白质印迹法检测胰腺微管相关蛋白轻链3(LC3Ⅱ/Ⅰ),选择性自噬接头蛋白(p62),含NLR家族Pyrin域蛋白3(NLRP3),白细胞介素1β(IL-1β)蛋白的表达水平。结果尿石素A干预后,糖尿病小鼠胰腺病理损伤明显改善;对照组、模型组、实验组血浆IL-1β水平分别为(39.82±5.25),(75.00±13.08),(56.81±14.35)pg·mL^-1;TNF-α水平分别为(352.91±20.30),(553.25±47.63),(405.28±36.49)pg·mL^-1;IL-10水平分别为(319.12±6.75),(221.18±28.04),(262.96±36.47)pg·mL^-1;胰腺NLRP3蛋白相对表达量分别为1.08±0.10,4.90±0.20,1.59±0.32;IL-1β蛋白相对表达量分别为0.99±0.10,2.69±0.25,1.87±0.11;LC3Ⅱ/Ⅰ蛋白相对表达量分别为1.00±0.11,1.89±0.32,2.94±0.15;p62蛋白相对表达量分别为1.00±0.12,2.50±0.25,1.71±0.15,模型组与对照组比较或实验组与模型组比较,上述指标的差异均有统计学意义(均P<0.05)。结论尿石素A改善糖尿病小鼠胰腺损伤可能与激活自噬,抑制NLRP3/IL-1β炎症信号通路有关。

Objective To investigate the effect of natural polyphenol urolithin A on pancreatic damage in diabetic mice,and to preliminary explore the role of autophagy and inflammatory mechanisms in it.Methods C57 BL/6 mice were randomly divided into normal feeding control group,high-fat feeding model group and test group,at the same time,test group was given urolithin A by gavage at a dose of 50 mg·kg^-1,after 6 weeks of feeding,streptozotocin was injected intraperitoneally to establish a type 2 diabetes model,and the administration was continued for 8 weeks.Hematoxylin-eosin staining was used to observe the pathological changes of the pancreas;the level of inflammatory cytokines was detected by enzyme-linked immunosorbent assay;the expression of microtubule-associated protein light chain 3(LC3Ⅱ/Ⅰ),selective autophagy adaptor protein(p62),NLR family Pyrin domain protein 3(NLRP3),and interleukin 1β(IL-1β)proteins were detected by Western blot.Results After urolithin A intervention,the pathological damage of the pancreas of diabetic mice was significantly improved;the levels of the IL-1βin the plasma of the control group,model group and test group were(39.82±5.25),(75.00±13.08),(56.81±14.35)pg·m L^-1,respectively;the levels of the TNF-αwere(352.91±20.30),(553.25±47.63),(405.28±36.49)pg·m L^-1,respectively;the levels of the IL-10 were(319.12±6.75),(221.18±28.04),(262.96±36.47)pg·m L^-1,respectively;the relative expressions of NLRP3 protein were 1.08±0.10,4.90±0.20,1.59±0.32,respectively;the relative expressions of IL-1βprotein were 0.99±0.10,2.69±0.25,1.87±0.11,respectively;the relative protein expressions of LC3Ⅱ/Ⅰwere 1.00±0.11,1.89±0.32,2.94±0.15,respectively;the relative expression levels of p62 protein were 1.00±0.12,2.50±0.25,1.71±0.15,respectively.There were significant differences of the aboves between model group and control group or test group and model group(all P<0.05).Conclusion Urolithin A improved pancreatic damage in diabetic mice may be related to activation of autophagy and inhibition of NLRP3/IL-1βinflammatory signaling pathway.