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

关键词:  高良姜素  白细胞介素-1受体相关激酶  丝裂原活化蛋白激酶  核因子-κB信号通路  糖尿病  大鼠  心肌损伤

Key words:  galangin  interleukin-1 receptor-associated kinase-1  mitogen-activated protein kinase  nuclear factor-κB signaling pathway  diabetes  rat  myocardial injury

摘要:

[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30mg/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、p38MAPK、NF-κBp65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、p38MAPK、NF-κBp65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、p38MAPK、NF-κBp65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。

Abstract:

[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.