The Role of Delta-Opioid Receptor in Mediating the Cardioprotective Effects of Morphine Preconditioning via the JAK2/STAT3 Pathway in a Failing Heart
Xinxin Pan, Chengxiao Guo, Baoli Wang, Biyun Cao, Juan Wu, Xinyu Chen, Shufang He, Ye Zhang, Shiyun JinBACKGROUND:
Failing heart is more likely to suffer from myocardial ischemia/reperfusion (I/R) injury. This poses a great challenge for anesthesiologists in managing patients with heart failure during major surgery. Evidence from animal studies suggests that the delta-opioid receptor (DOR) contributes to alleviating acute myocardial injuries. However, little is known regarding the cardioprotective effects of cardiac DOR in patients with chronic heart failure. This study aimed to examine DOR expression in failing hearts and explore how DOR regulates the Janus kinase signal transducer and activator of the transcription-3 (JAK/STAT3) pathway to mediate morphine-induced cardio protection in heart failure.
METHODS:
We measured the DOR protein levels in human and rat heart tissues with chronic heart failure. To investigate the cardioprotective role of DOR, we administered the DOR-specific antagonist, naltrindole (NTD), and JAK2 inhibitor, AG490, before morphine preconditioning (MPC) in an isolated perfusion model of myocardial I/R injury in postinfarcted failing rat heart. We examined the infarct size, cardiac enzymes, cardiac function, cardiomyocyte apoptosis, apoptosis-related proteins, and STAT3 phosphorylation in the heart.
RESULTS:
The protein levels of DOR were significantly elevated in the myocardial tissues of humans and rats with chronic heart failure, by 1.4-fold (mean difference 0.41; 95% confidence interval [CI], 0.04–0.78;
CONCLUSIONS:
DOR protein levels increased in failing hearts of both humans and rats. Blocking cardiac DOR selectively reduced morphine-induced cardio protection by inhibiting the JAK2/STAT3 pathway. These findings indicate that cardiac DOR is a potential therapeutic target for protecting against heart failure due to I/R injury.