Role of the JAK/STAT signaling pathway in the pathogenesis of acute myocardial infarction in rats and its effect on NF-κB expression.

The Janus kinase/signal transducer and activator of transcription pathway (JAK/STAT signaling pathway) is involved in the development of numerous cardiovascular diseases, although the specific role of this pathway in the pathogenesis of acute myocardial infarction (AMI) has not been elucidated. The purpose of this study was to evaluate the role of the JAK/STAT signaling pathway in the onset of AMI in rats. We also tested the effect of this pathway on nuclear factor κB (NF-κB) expression in the myocardium and tumor necrosis factor-α (TNF-α) levels in the plasma of AMI rats. An AMI rat model was successfully established and AG490 was used to block the JAK/STAT signaling pathway. The plasma TNF-α levels of AMI rats were measured by ELISA. The protein expression of NF-κB in the myocardial cells of AMI rats was detected by immunohistochemistry. The infarction area was significantly smaller in rats treated with AG490 after coronary artery ligation (group C) compared with that in the myocardial infarction control group (group B). The left ventricular mass indices in the sham surgery group (group A) and group C were significantly lower compared with those of group B. Plasma TNF-α concentrations in group B were significantly higher compared with those of groups A and C. There were significantly fewer cardiomyocytes positively exhibiting NF-κB protein expression in groups A and C compared with group B. The JAK/STAT signaling pathway is involved in the onset of myocardial infarction and may also be involved in left ventricular remodeling after myocardial infarction. The involvement of the JAK/STAT signaling pathway in the onset of myocardial infarction may be correlated with its effects on the expression of NF-κB and TNF-α.