Delta opioid peptide (D-Ala۲, D-Leu۵)-enkephalin (DADLE) mitigates myocardial ischemia-reperfusion injury by inhibiting the TRAF۶/NF-κB/NLRP۳ pathway

Objective(s): This study aimed to assess the dose-dependent effect of DADLE and to explore its relationship with the TRAF۶/NF-κB/NLRP۳ pathway.Materials and Methods: After ۴۵ min of ischemia, reperfusion was sustained for ۲۴ hr in mice to establish the myocardial infarction model. DADLE was administered at doses of ۰.۲۵, ۰.۵, or ۱ mg/kg to this model. TTC-Evans Blue double staining, HE staining, and Masson staining were conducted to evaluate myocardial injury. TUNEL staining was used to detect apoptosis. Western blotting and immunofluorescence staining were applied to measure levels of TRAF۶, NF-κB p۶۵, NLRP۳, caspase-۱, pro-caspase-۱, and ASC. ELISA assays were used to assess TNF-α and IL-۱β levels. Results: DADLE at all three doses lessened the infarcted area compared with the PBS control. DADLE at ۰.۵ mg/kg was more efficacious than ۰.۲۵ and ۱ mg/kg in reducing the infarcted size, pathological scores, and fibrosis. DADLE effectively reduced the number of apoptotic cells as shown by the TUNEL assay. Levels of TRAF۶, NF-κB p۶۵, ASC, NLRP۳, caspase-۱, and pro-caspase-۱ proteins were increased after ischemia-reperfusion (I/R) but were reversed by DADLE. Immunofluorescence staining results for NF-κB and NLRP۳ demonstrated similar changes. ELISA assays showed that TNF-α and IL-۱β concentrations were increased in the model and reversed by DADLE. Conclusion: DADLE can significantly ameliorate myocardia ischemia-reperfusion injury (MIRI), with the dosage of ۰.۵ mg/kg presenting the greatest benefit. DADLE may exert its protective effects by activating the TRAF۶/NF-κB/NLRP۳ signaling pathway.

کلیدواژه ها:

Delta ، Myocardial reperfusion injury ، NF-kappa B ، NLRP۳ protein ، Opioid ، Receptor ، TNF receptor-associated factor ۶