摘要
目的观察金丝桃苷(hyperoside,Hyp)对严重烧伤大鼠早期心肌损伤的保护作用并初步探究其分子机制。方法将60只8周龄雄性SD大鼠随机分为4组:假烧伤组(sham)、烧伤组、烧伤加金丝桃苷处理组(金丝桃苷组,Hyp组)和烧伤加金丝桃苷处理加SIRT1抑制剂组(EX527组)。采用背部烫伤法构建30%体表面积Ⅲ度烧伤大鼠模型。Hyp组待烧伤处理12 h,并在烧伤后0,3,6 h灌胃给予Hyp(30 mg/kg)完成药物处理,EX527+Hyp组在大鼠Hyp药物灌胃处理的同时给予5 mg/kg EX527腹腔注射。用颈动脉插管并记录大鼠心肌力学指标;HE染色法观察心肌组织形态结构改变;免疫组化染色法检测心肌组织中性粒细胞的浸润程度;血生化分析仪检测大鼠血清中cTnI和CK-MB的含量;试剂盒检测大鼠血清中TNF-α和IL-1β的含量以及心肌组织中SOD和GSH的含量;Western blot法检测SIRT1、Ac-foxo1、gp91phox、Nox4、IL-6、IL-1β和cleaved Caspase-3的蛋白表达水平。结果与sham组相比,烧伤组大鼠早期心肌力学指标明显受损(P<0.05);心肌纤维排列明显紊乱,中性粒细胞浸润程度显著上升;大鼠血清中cTnI、CK-MB、TNF-α和IL-1β的含量明显增加,心肌组织中SOD和GSH的含量显著降低(P<0.05);心肌组织中炎症及氧化应激相关蛋白的表达显著上调,SIRT1蛋白表达明显下调,foxo1的乙酰化水平和凋亡蛋白cleaved Caspase-3的表达显著升高(P<0.05)。与烧伤组相比,Hyp组大鼠早期心肌力学指标明显改善(P<0.05),心肌组织病理改变和中性粒细胞的浸润程度明显减轻,大鼠血清中cTnI、CK-MB、TNF-α和IL-1β的含量显著降低,同时心肌组织中SOD和GSH的含量升高(P<0.05);心肌组织中炎症及氧化应激相关蛋白的表达明显下调,SIRT1蛋白表达明显上调,foxo1的乙酰化水平和凋亡蛋白cleaved Caspase-3的表达下调(P<0.05)。然而Hyp改善的心肌力学指标及其减轻心肌氧化应激及炎症损伤的保护效果均可被SIRT1特异性阻断剂EX527显著逆转(P<0.05)。结论Hyp可通过抗氧化应激与抗炎作用减轻严重烧伤大鼠早期心肌损伤,其分子机制可能与其激活SIRT1信号通路有关。
Objective To observe the protective effect of hyperoside(Hyp)against early myocardial injury in severely burned rats and explore its molecular mechanisms.Methods Sixty male SD rats(200-250 g)were randomly divided into 4 groups:sham group,burn group,Hyp group and EX527+Hyp group.The animal model was established by subjecting rats to third degree burns in 30%of the total burned surface area(TBSA)on the back.After burn for 12 h,Hyp(30 mg/kg)was gavaged at 0,3,and 6 h after burn in Hyp group.EX527(5 mg/kg)was given intraperitoneal injection at the same time while Hyp was administered in EX527+Hyp group.Carotid artery intubation was performed to record the myocardial mechanical parameters of rats.HE staining was used to observe the morphological and structural changes of myocardium.Immunohistochemical staining was used to detect the infiltration of neutrophils.The blood biochemical analyzer was used to measure the serum levels of cTnI and CK-MB.Special kits were used to measure the contents of TNF-αand IL-1βin serum and the contents of SOD and GSH in myocardial tissue.Western blot was used to detect the protein expression levels of SIRT1,Ac-foxo1,gp91 phox,Nox4,IL-6,IL-1βand cleaved Caspase-3.Results Compared with sham group,the early myocardial mechanical parameters were significantly decreased in burn group(P<0.05),and the myocardial fiber arrangement was signi-ficantly disordered,and the degree of neutrophil infiltration was significantly increased.Compared with sham group,the serum levels of cTnI,CK-MB,TNF-αand IL-1βwere significantly increased,and the contents of SOD and GSH in myocardial tissue were significantly decreased in burn group(P<0.05).Compared with sham group,the expression levels of inflammation and oxidative stress related proteins were significantly up-regulated in burn group,the expression of SIRT1 protein was down-regulated,and the acetylation level of foxo1 and the expression of cleaved Caspase-3 increased(P<0.05).Hyp treatment significantly improved the early myocardial mechanical indexes,reduced the pathological changes of myocardium and infiltration of neutrophils,decreased the serum levels of cTnI,CK-MB,TNF-αand IL-1β,elevated the contents of SOD and GSH in cardiac tissue of severely burned rats(all P<0.05).Additionally,Hyp treatment significantly decreased the expression of inflammatory and oxidative stress-related proteins,increased the expression of SIRT1,and decreased the acetylation level of foxo1 and the expression of cleaved Caspase-3(all P<0.05).However,the effects of Hyp in improving myocardial mechanical parameters,reducing the oxidative stress and inflammatory damage were significantly reversed by SIRT1 specific inhibitor EX527(P<0.05).Conclusion Hyp ameliorates the early myocardial injury of severely burned rats by exhibiting its anti-oxidative stress and anti-inflammatory effects via activating SIRT1 signaling pathway.
作者
王长鹰
李军
WANG Changying;LI Jun(Department of Cardiology,Xi’an International Medical Center,Xi’an 710075,China;Department of Cardiovascular Diseases,Second Affiliated Hospital,Air Force Medical University)
出处
《山西医科大学学报》
CAS
2019年第12期1718-1724,共7页
Journal of Shanxi Medical University
基金
国家自然科学基金面上项目(81470537)
