Cardiopulmonary Bypass Decreases Activation of the Signal Transducer and Activator of Transcription 3 (STAT3) Pathway in Diabetic Human Myocardium

Background Cardiopulmonary bypass (CPB) is associated with increased myocardial oxidative stress and apoptosis in diabetic patients. A mechanistic understanding of this relationship could have therapeutic value. To establish a possible mechanism, we compared the activation of the cardioprotective signal transducer and activator of transcription 3 (STAT3) pathway between patients with uncontrolled diabetes (UD) and nondiabetic (ND) patients. Methods Right atrial tissue and serum were collected before and after CPB from 80 patients, 39 ND and 41 UD (HbA 1c ≥6.5), undergoing cardiac operations. The samples were evaluated with Western blotting, immunohistochemistry, and microarray. Results On Western blot, leptin levels were significantly increased in ND post-CPB ( p p p p p  = 0.05) in the UD patients. The oxidative stress marker nuclear factor-κB was significantly higher ( p Conclusions Compared with ND, UD myocardium demonstrated attenuation of the cardioprotective STAT3 pathway. Identification of this mechanism offers a possible target for therapeutic modulation.