基于NF-κB通路探究亚麻油干预心肌梗死大鼠心肌纤维化的作用机制

The Protective Effect of Linseed Oil on Myocardial Fibrosis in Rats with Myocardial Infarction Based on NF-κB Pathway

目的:基于核转录因子-κB(NF-κB)通路探究亚麻油对心肌梗死大鼠心肌纤维化的保护作用。方法:将54只大鼠分为6组:假手术组(CO组)、模型组(MO组)、亚麻油低剂量组(LL组)、亚麻油中剂量组(LM组)、亚麻油高剂量组(LH组)、卡托普利组(CA组),每组9只。建立心肌梗死大鼠模型,CO组大鼠则将手术线穿过肺动脉圆锥与左心耳之间,不进行冠状动脉结扎。建模成功后,LL组、LM组、LH组大鼠分别给予不同浓度的亚麻油灌胃,CA组大鼠给予卡托普利10 mg/kg,以上用药均为每日1次,共干预4周,CO组及MO组大鼠给予等体积生理盐水灌胃。采用超声检测大鼠左心室射血分数(LVEF)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室短轴缩短率(LVFS)参数。聚合酶链式反应(PCR)法检测大鼠心肌组织中低氧诱导因子-1α(HIF-1α)、结缔组织生长因子(CTGF)的表达;免疫印迹法检测大鼠心肌组织中NF-κB、NF-κB p65、肿瘤坏死因子-α(TNF-α)蛋白表达。采用Masson染色法进行胶原纤维染色,并检测胶原纤维容积分数(CVF)。结果:与CO组相比,MO组LVFS、LVEF降低,LVESD、LVEDD升高(P<0.05);与MO组相比,LL组、LM组、LH组、CA组LVFS、LVEF升高,LVESD、LVEDD降低(P<0.05)。与CO组相比,MO组CVF值明显升高(P<0.05);与MO组相比,其他药物干预组CVF值明显降低(P<0.05)。与CO组相比,MO组心肌组织中CTGF mRNA及NF-κB、TNF-α、NF-κB p65表达增加,HIF-1αmRNA表达下降(P<0.05);与MO组相比,LL组、LM组、LH组、CA组HIF-1αmRNA表达增加,CTGF mRNA、NF-κB、TNF-α、NF-κB p65表达降低(P<0.05),且随着亚麻油浓度的升高,大鼠各项指标改善明显,LH组与CA组大鼠各项指标比较差异无统计学意义(P>0.05)。结论:亚麻油可以抑制大鼠心肌纤维化,改善心功能,对心肌梗死大鼠心肌起保护作用,其作用机制可能与调控NF-κB相关信号通路有关。

Objective:To investigate the protective effect of linseed oil on myocardial fibrosis in rats with myocardial infarction based on nuclear factor κB(NF-κB)pathway.Methods:Fifty-four rats were randomly divided into 6 groups:control group(CO group),model group(MO group),linseed oil low dose group(LL group),linseed oil medium dose group(LM group),linseed oil high dose group(LH group),and Captopril group(CA group),with 9 rats in each group.The anterior descending branch of the left coronary artery was ligated in the myocardial infarction rat model,while the surgical line was passed between the pulmonary conus and the left auricle in the CO group,without the coronary artery ligation.After successful modeling,rats in LL group,LM group,and LH group were given different concentrations of linseed oil respectively,and rats in CA group were given captopril 10 mg/kg,once a day,for a total of 4 weeks.Rats in CO group and MO group were given equal volume of normal saline by gavage.Left ventricular ejection fraction(LVEF),left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD),and left ventricular shortening fraction(LVFS)were detected by ultrasonography.Myocardial histopathology and myocardial fibrosis were observed by hematoxylin-eosin(HE)staining and Masson staining.The expression of hypoxic inducible factor 1α(HIF-1α)and connective tissue growth factor(CTGF)in rat myocardial tissue were detected by polymerase chain reaction(PCR).The protein expression of NF-κB,NF-κB p65,and tumor necrosis factor-α(TNF-α)were detected by western Blotting.The collagen fiber volume fraction(CVF)in collagen fibers was mesured with Masson staining.Results:Compared with CO group,LVFS and LVEF were decreased,and LVESD and LVEDD were increased in MO group(P<0.05).Compared with MO group,LVFS and LVEF were increased,and LVESD and LVEDD were decreased in LL,LM,LH,and CA groups(P<0.05).Compared with CO group,the CVF value in MO group was increased(P<0.05).Compared with MO group,the CVF value of the other drug intervention groups was decreased(P<0.05).Compared with CO group,the expression of CTGF mRNA and NF-κB,TNF-α,and NF-κB p65 in myocardial tissue was significantly increased,and the expression of HIF-1α mRNA was decreased in MO group(P<0.05).Compared with MO group,the expression of HIF-1α mRNA was increased,and the expression of CTGF mRNA,NF-κB,TNF-α,and NF-κB p65 was decreased in LL,LM,LH,and CA groups(P<0.05),and with the increase of linseed oil concentration,the indexes of rats were improved significantly.There was no significant difference in the indicators between LH group and CA group(P>0.05).Conclusion:Linseed oil can inhibit myocardial fibrosis of rats,improve cardiac function,and protect the myocardium of rats with myocardial infarction.Its mechanism may be related to the regulation of NF-κB-related signal pathways.