摘要目的 探讨辛伐他汀对心肌肥厚的防治作用及其与JAK激酶/信号转录活化因子(JAK/STAT)信号转导通路的关系.方法 采用心肌营养素-1(CT-1)诱导新生大鼠心肌细胞肥大模型和腹主动脉缩窄术建立心肌肥厚动物模型.通过改良Lowry法测定心肌细胞总蛋白含量.相差显微镜测定心肌细胞表面积.逆转录聚合酶链法检测血管紧张素原(AGT)mRNA及c-fos mRNA表达.尾动脉无创测量大鼠收缩压的变化.称量心脏重量/体重(HW/BW)、左心室重量/体重(LVW/BW)比值.Western blot方法 检测磷酸化-JAK激酶(p-JAK2)和磷酸化-信号转录活化因子(p-STAT3)蛋白表达.结果 (1)辛伐他汀能明显抑制CT-1诱导的心肌细胞总蛋白含量增加(9.20 μg/105cell降至6.66 μg/105cell)和心肌细胞表面积增加(1741.63 μm2降至826.76 μm2).(2)辛伐他汀、JAK激酶抑制剂AG490均可明显抑制CT-1诱导的心肌细胞p-JAK2和p-STAT3蛋白表达以及AGT mRNA和c-fos mRNA表达(P<0.01).(3)辛伐他汀可明显降低腹主动脉缩窄大鼠的收缩压[186.64 mm Hg(1 mm Hg=0.133 kPa)降至132.56 mm Hg]、HW/BW比值(3.87 mg/g降至3.29 mg/g)、LVW/BW比值(2.74 mg/g降至2.32 mg/g).(4)辛伐他汀可明显抑制腹主动脉缩窄大鼠心肌p-JAK2和p-STAT3蛋白表达(P<0.01).结论 辛伐他汀对CT-1诱导的大鼠心肌细胞肥大和腹主动脉缩窄所致心肌肥厚均具有明显的防治作用,其作用机制可能与其抑制JAK/STAT信号通路的激活,减少肥厚相关基因AGT mRNA、c-fos mRNA表达有关.

abstractsObjective To investigate the effects of simvastatin (SIM) on in vivo and in vitro cardiac hypertrophy models and changes on JAK/STAT signal pathways. Methods Myocardial hypertrophy was induced by Cardiotrophin-1 (CT-1) in neonatal cardiomyocytes and by abdominal aortic constriction (AC) for 4 weeks in adult SD rats. In vitro study groups were as follows (n =3 each) : (1) control, (2) CT-1 ( 10-10 mol/L), (3) CT-1 + SIM ( 10-6mol/L), (4) CT-1 + AG490(JAK inhibitor,10-4mol/L), (5) SIM (10-6mol/L), (6) AG490 (10-4 mol/L). In vivo study groups were as follows (n = 8 each):(1) sham group, (2) AC group, (3) AC + SIM group, (4) AC + captopril group. Total protein content was measured by Lowry′s method and the cell surface area was measured by phase contrast microscope. The expression of AGT Mrna and c-fos Mrna were detected by RT-PCR. Systolic blood pressure(SBP) ,heart weight/body weight (HW/BW) and left ventricle weight/body weight (LVW/BW) were measured. The expressions of p-JAK2 and p-STAT3 were detected by Western blot. Results The total protein content and cardiomyocytes size were significantly increased in CT-1 treated cells and which could be blocked by SIM. The expressions of p-JAK2 and p-STAT3 as well as the expression of AGT Mrna and c-fos Mrna significantly activated by CT-1, which could be inhibited by SIM or Janus Kinase-selective inhibitor AG490. Similar as captopril, SIM also attenuated cardiac hypertrophy in AC rats as shown on reduced systolic blood pressure, heart weight to body weight, left ventricular weight to body weight ratios as well as cross sectional area of cardiomyocytes. Conclusion SIM prevented CT-1 and AC induced cardiomyocyte hypertrophy via inhibiting JAK/STAT pathways.