高良姜素抑制IRAK-1/MAPK/NF-κB信号通路对糖尿病大鼠心肌损伤的影响

Impact of galangin on myocardial injury in diabetic rat by inhibiting IRAK-1/MAPK/NF-κB signaling pathway

[目的]探讨高良姜素通过抑制白细胞介素-1受体相关激酶(IRAK-1)/丝裂原活化蛋白激酶(MAPK)/核因子-κB(NF-κB)信号通路实现对糖尿病大鼠心肌损伤的缓解。[方法]高糖高脂连续饲养8周后,一次性腹腔注射30 mg/kg链脲佐菌素(STZ)造模,糖尿病模型成功大鼠随机分为模型组、高良姜素组、高良姜素+pc-NC组、高良姜素+pc-IRAK-1组,每组8只。对照组8只大鼠正常饲养相同时间。血糖仪测量血糖水平;心脏超声检测左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF);Masson染色检测心肌组织纤维化情况,分析心肌胶原容积百分比(CVF);透射电镜观察心肌组织超微结构;试剂盒检测丙二醛(MDA)、超氧化物歧化酶(SOD)、乳酸脱氢酶(LDH)、肌酸激酶(CK)、一氧化氮(NO)、一氧化氮合成酶(NOS)水平;蛋白质免疫印迹检测心肌组织中诱导型一氧化氮合酶(iNOS)、内皮型一氧化氮合酶(eNOS)、IRAK-1、p38 MAPK、NF-κB p65蛋白表达情况。[结果]建模后给药前,大鼠血糖水平升高(P<0.05),说明造模成功。给药后,模型组大鼠心肌细胞间质和血管旁着色深,且透射电镜下可见心肌结构紊乱,部分肌丝溶解;高良姜素组上述症状均有所缓解,高良姜素+pc-IRAK-1组症状介于模型组和高良姜素组之间。与对照组相比,模型组血糖、LVEDD、LVESD、CVF水平,MDA含量,iNOS、IRAK-1、p38 MAPK、NF-κB p65蛋白水平升高(P<0.05),LVEF水平,CK、NO含量,SOD、LDH活性,NOS活力及eNOS蛋白水平降低(P<0.05);与模型组相比,高良姜素组血糖、LVEDD、LVESD、CVF水平,MDA含量,iNOS、IRAK-1、p38 MAPK、NF-κB p65蛋白水平降低(P<0.05),LVEF水平,CK、NO含量,SOD、LDH活性,NOS活力及eNOS蛋白水平升高(P<0.05);在高良姜素处理基础上升高IRAK-1的表达可抑制高良姜素的作用效果。[结论]高良姜素可通过抑制IRAK-1/MAPK/NF-κB信号通路实现对糖尿病大鼠心肌损伤的缓解。

[Objective]To investigate whether galangin can alleviate myocardial injury in diabetic rats by inhibiting the interleukin-1 receptor-associated kinase-1(IRAK-1)/mitogen-activated protein kinase(MAPK)/nuclear factor-κB(NF-κB)signaling pathway.[Methods]After continuous feeding with high sugar and high fat for 8 weeks,30 mg/kg streptozotocin(STZ)was injected intraperitoneally at one time to establish a model,the successful diabetic model rats were randomly grouped into model group,galangin group,galangin+pc-NC group,and galangin+pc-IRAK-1 group,8 animals per group.The 8 rats in the control group were fed normally for the same time.Glucose meter was applied to measure blood sugar level;cardiacultrasound was used to detect left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD)and left ventricular ejection fraction(LVEF);masson staining was applied to detect myocardial tissue fibrosis and to analyze myocardial collagen volume percentage(CVF);transmission electron microscopy was applied to observe the ultrastructure of myocardial tissue;kits were applied to detectthe levels ofmalondialdehyde(MDA),superoxide dismutase(SOD),lactate dehydrogenase(LDH),creatine kinase(CK),nitric oxide(NO),and nitric oxide synthase(NOS);western blot was used to detect the protein expression of inducible nitric oxide synthase(iNOS),endothelial nitric oxide synthase(eNOS),IRAK-1,p38 MAPK,and NF-κB p65 in myocardial tissue.[Results]After modeling and before administration,the blood glucose level increased(P<0.05),the molding successed.After administration,the interstitial and paravascular myocardial cells of the model group were stained deeply,and the myocardial structure was disordered under the transmission electron microscope,and some myofilaments were dissolved;the above symptoms in the galangin group were relieved,and the symptoms in the galangin+pc-IRAK-1 group were between the model group and the galangin group.Compared with the control group,the blood glucose,LVEDD,LVESD and CVF levels,MDA content,iNOS,IRAK-1,p38 MAPK and NF-κB p65 protein levels in the model group increased(P<0.05),the LVEF level,CK and NO contents,SOD,LDH and NOS activitiesand eNOS protein level decreased(P<0.05);compared with the model group,the blood glucose,LVEDD,LVESD and CVF levels,MDA content,iNOS,IRAK-1,p38 MAPK and NF-κB p65 protein levels in the galangin group decreased(P<0.05),the LVEF level,CK and NO contents,SOD,LDH and NOS activities and eNOS protein levelincreased(P<0.05);elevating the expression of IRAK-1 on the basis of galangin treatment could inhibit the effect of galangin.[Conclusion]Galangin can alleviate myocardial injury in diabetic rats by inhibiting IRAK-1/MAPK/NF-κB signaling pathway.