橙皮素通过自噬调控改善压力负荷小鼠的心肌肥厚

Hesperetin improves myocardial hypertrophy in pressure-overloaded mice through autophagy regulation.

目的通过腹主动脉缩窄(AB)术构建小鼠心肌肥厚模型,观察橙皮素对心肌肥厚及相关自噬的影响。方法将30只C57BL/6小鼠分为5组:假手术组、手术组(AB组)、橙皮素+手术组(Hes-AB组)、雷帕霉素+手术组(Rapa-AB组)、橙皮素+3-甲基腺嘌呤+手术组(Hes-3-MA-AB组),每组各6只。假手术组仅分离暴露小鼠腹主动脉即可,不行AB术;其他4组均行AB术,Hes-AB组术后给予橙皮素溶液(30 mg/kg)灌胃,每日1次;Rapa-AB组术后给予雷帕霉素(0.8 mg/kg)腹腔注射,每日1次;Hes-3-MA-AB组术后给予橙皮素溶液(30 mg/kg)灌胃和3-甲基腺嘌呤(3-MA)(80 mg·kg^(-1)·d^(-1))腹腔注射,每日1次。假手术组和AB组分别给予相同体积的0.5%羧甲基纤维素溶液灌胃,每日1次。术后4周,采用超声测定收缩末期左室后壁厚度(LVPWs)、舒张末期左室后壁厚度(LVPWd)、左室收缩末期室间隔厚度(IVSs)以及左室舒张末期室间隔厚度(IVSd),并获取小鼠心肌组织,采用蛋白质印迹法检测自噬标志蛋白LC3Ⅱ、P62、Beclin1的表达。结果与假手术组比较,AB组小鼠的LVPWs、LVPWd、IVSs、IVSd均明显增加,差异均有统计学意义(P<0.05);与AB组相比较,Hes-AB组、Rapa-AB组小鼠的LVPWs、LVPWd、IVSs、IVSd均明显减少,差异均有统计学意义(P<0.05);与Hes-AB组比较,Hes-3-MA-AB组小鼠的LVPWs、LVPWd、IVSs、IVSd均明显增加,差异均有统计学意义(P<0.05)。与假手术组比较,AB组LC3Ⅱ下调,P62上调,差异均有统计学意义(P<0.05);与AB组比较,Hes-AB组、Rapa-AB组LC3Ⅱ上调,P62下调,差异均有统计学意义(P<0.05);与Hes-AB组比较,Hes-3-MA-AB组LC3Ⅱ下调,P62上调,差异均有统计学意义(P<0.05);Beclin1在4组间比较,差异无统计学意义(P>0.05)。结论橙皮素可改善压力负荷小鼠的心肌肥厚,这种作用可能通过自噬调控实现。

Objective To observe the effect of hesperetin on myocardial hypertrophy and related autophagy,a mouse cardiac hypertrophy model was constructed by abdominal aortic coarctation(AB)surgery.Methods Thirty C57BL/6 mice were divided into sham group,AB group,Hes-AB group,Rapa-AB group,Hes-3-MA-AB group,6 mice in each group.In sham group,abdominal aorta was isolated and exposed without AB surgery,AB surgery was performed in the other four groups,hesperidin solution(30 mg/kg)was given intragastrically once a day in Hes-AB group,and rapamycin(0.8 mg/kg)was injected intraperitoneally in Rapa-AB group once a day.Hes-3-MA-AB group was treated with hesperidin solution(30 mg/kg)and intraperitoneal injection of 3-methyladenine(3-MA)(80 mg·kg^(-1)·d^(-1))once a day after operation.Sham group and AB group were given 0.5%carboxymethyl cellulose solution of the same volume by intragastric administration,once a day.The end-systolic left ventricular posterior wall thickness(LVPWs),end-diastolic left ventricular posterior wall thickness(LVPWd),left ventricular end-systolic septal thickness(IVSs)and left ventricular end-diastolic septal thickness(IVSd)were measured by ultrasound at 4 weeks after operation,and the mice myocardial tissue was obtained,the expressions of autophagy marker proteins LC3ⅡP62 and Beclin1 were detected by Western blotting.Results Compared with the sham group,the LVPWs,LVPWd,IVSs,and IVSd of the mice in the AB group were significantly increased,and the differences were statistically significant(P<0.05);compared with the AB group,the LVPWs,LVPWd,IVSs,and IVSd of the mice in the Hes-AB group and the Rapa-AB group were significantly decreased,and the differences were statistically significant(P<0.05);compared with the Hes-AB group,the LVPWs,LVPWd,IVSs,and IVSd of the mice in the Hes-3-MA-AB group were significantly increased,and the differences were statistically significant(P<0.05).Compared with the sham group,the LC3Ⅱwas down-regulated and the P62 was up-regulated in the AB group,and the differences were statistically significant(P<0.05);compared with AB group,LC3Ⅱwas up-regulated and P62 was down-regulated in Hes-AB group and Rapa-AB group,and the differences were statistically significant(P<0.05);compared with Hes-AB group,LC3Ⅱwas down-regulated and P62 was up-regulated in Hes-3-MA-AB group,and the differences were statistically significant(P<0.05);there was no statistically significant difference between Beclin1 among the four groups(P>0.05).Conclusion Hesperetin can improve myocardial hypertrophy in pressure-overloaded mice,and this effect may be achieved through the regulation of autophagy.