褪黑素对心力衰竭大鼠JAK1/STAT3信号通路的调节作用

Regulatory effect of melatonin on JAK1/STAT3 signaling pathway in rats with heart failure

目的探讨褪黑素对心力衰竭(HF)大鼠JAK1/STAT3信号通路的影响。方法将SD雄性大鼠通过左前降支冠状动脉结扎术建立HF模型并随机分为模型组和褪黑素低剂量组(5 mg/kg)、中剂量组(10 mg/kg)、高剂量组(20 mg/kg),将正常大鼠作为对照组,20只/组。对照组和模型组灌胃给药生理盐水,所有组别连续灌胃4周。采用无创尾动脉血压测量分析系统检测各组大鼠给药后的血压及心率;采用彩色多普勒超声诊断仪检测大鼠左心室舒张末期容积(left ventricular end diastolic volume,LVEDV)、左心室收缩末期容积(left ventricular end systolic volume,LVESV)、心室舒张末期室间隔厚度(IvSd)、左心室舒张末期直径(left ventricular end diastolic diameter,LVIDd)、左心室收缩末期直径(left ventricular end systolic diameter,LVID)、舒张早期二尖瓣血流速度/舒张晚期二尖瓣血流速度比值(E/A)、射血分数(ejection fraction,EF)、收缩分数(fractional shortening,FS)水平;采用ELISA试剂盒检测大鼠治疗前后血清白介素6(interleukin 6,IL-6)、肿瘤坏死因子α(tumor necrosis factor alpha,TNF-α)、内皮素(endothelin,ET)及一氧化氮(nitric oxide,NO)水平;采用HE染色检测大鼠心脏组织病变;采用Western blot检测大鼠治疗后心脏Janus激酶1(Janus kinase 1,JAK1)、磷酸化JAK1(phosphorylated JAK1,p-JAK1)、信号传导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)、磷酸化STAT3(phosphorylated STAT3,p-STAT3)、金属基质蛋白酶2(metal matrix protease2,MMP-2)、半胱氨酸蛋白酶3(Caspase-3)、胶原蛋白Ⅰ(CollagenⅠ)表达。结果相较于对照组,模型组及褪黑素低、中、高剂量组血压、心率、E/A、EF、FS均有不同程度地下降(P<0.05),LVEDV、LVESV、IvSd、LVIDd、LVIDs、IL-6、TNF-α、ET、NO、JAK1、pJAK1、STAT3、p-STAT3、MMP-2、Caspase-3、CollagenⅠ均有不同程度地升高(P<0.05),相较于模型组,褪黑素低、中、高剂量组血压、心率、E/A、EF、FS均显著上升(P<0.05),LVEDV、LVESV、IvSd、LVIDd、LVIDs、IL-6、TNF-α、ET、NO、JAK1、p-JAK1、STAT3、p-STAT3、MMP-2、Caspase-3、CollagenⅠ均显著降低(P<0.05),且均呈褪黑素浓度依赖性趋势,对照组大鼠心肌细胞结构完整、排列整齐,细胞间隙正常;模型组大鼠心肌细胞结构异常,且排列紊乱,细胞间隙较大;褪黑素低、中、高剂量组大鼠心肌细胞结构趋于完整,细胞排列整齐,细胞间隙正常,且呈褪黑素浓度依赖性趋势。结论褪黑素可改善HF大鼠左心室重构,可能与抑制JAK1/STAT3信号通路有关。

To investigate the effect of melatonin on JAK1/STAT3 signaling pathway in heart failure(HF)rats.HF model was established in SD male rats by ligation ofleft anterior descending coronary artery and the HF ratswere randomly divided into the model group,melatoninlow-dose group(5 mg/kg),melatonin middle-dose group(10 mg/kg)and melatonin high-dose group(20 mg/kg),with 20 rats in each group,while 20 normal rats were used as control group.The control group and the model groupwere given normal saline,and all groups had been treated for 4 weeks.A non-invasive tail artery blood pressuremeasurement and analysis system was used to detect the blood pressure and heart rate of all rats after administration;color Doppler ultrasound was used to detect left ventricular end diastolic volume(LVEDV),left ventricular endsystolic volume(LVESV),ventricular end diastolic septal thickness(Iv Sd),left ventricular end diastolic diameter(LVIDd),left ventricular end systolic diameter(LVID),early diastolic mitral valve blood flow velocity/late diastolicmitral valve blood flow velocity ratio(E/A),ejection fraction(EF),fractional shortening(FS)levels of rats.ELISA kitswas used to detect the levels of serum interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),endothelin(ET)and nitric oxide(NO)before and after treatment in rats.HE staining was used to detect rat heart tissue lesions;Western blot was used to detect the expression of Janus kinase 1(JAK1),phosphorylated JAK1(p-JAK1),signaltransducer and activator of transcription 3(STAT3),phosphorylated STAT3(p-STAT3),metal matrix protease 2(MMP-2),Caspase-3,CollagenⅠin the rat heart after treatment.Compared with the control group,the bloodpressure,heart rate,E/A,EF,and FS of the model group and all melatonin groups had decreased(P<0.05),while thelevels of LVEDV,LVESV,Iv Sd,LVIDd,LVIDs,IL-6,TNF-α,ET,NO,JAK1,p-JAK1,STAT3,p-STAT3,MMP-2,Caspase-3,CollagenⅠwere increased(P<0.05).Compared with the model group,the blood pressure,heart rate,E/A,EF,FS of the melatonin low-,medium-and high-dose groups increased significantly(P<0.05),while thelevels of LVEDV,LVESV,Iv Sd,LVIDd,LVIDs,IL-6,TNF-α,ET,NO,JAK1,p-JAK1,STAT3,p-STAT3,MMP-2,Caspase-3,CollagenⅠwere decreased significantly(P<0.05)in a melatonin concentration-dependent manner.The myocardial cells of the control group had complete structure and neat arrangement,and the intercellular spaceswere normal;the structure of myocardial cells in the model group was abnormal,and the arrangement wasdisordered,with large intercellular spaces;the structure of myocardial cells in the melatonin low-,medium-andhigh-dose groups tended to be intact,the cells were arranged neatly,the intercellular spaces were normal,and allthese changes showed a concentration-dependent trend of melatonin.Taken together,melatonin can improve leftventricular remodeling in HF rats,which may be related to the inhibition of JAK1/STAT3 signaling pathway.