The Protective Role of Interleukin-33 in Myocardial Ischemia and Reperfusion Is Associated with Decreased HMGB1 Expression and Up-Regulation of the P38 MAPK Signaling Pathway.

Interleukin-33 (IL-33) plays a protective role in myocardial ischemia and reperfusion (I/R) injury, but the underlying mechanism was not fully elucidated. The present study was designed to investigate whether IL-33 protects against myocardial I/R injury by regulating both P38 mitogen-activated-protein kinase (P38 MAPK), which is involved in one of the downstream signaling pathways of IL-33, and high mobility group box protein 1 (HMGB1), a late pro-inflammatory cytokine. Myocardial I/R injury increased the level of IL-33 and its induced receptor (sST) in myocardial tissue. Compared with the I/R group, the IL-33 group had significantly lower cardiac injury (lower serum creatine kinase (CK), lactate dehydrogenase (LDH), and cTnI levels and myocardial infarct size), a suppressed inflammatory response in myocardial tissue (lower expression of HMGB1, IL-6, TNF-α and INF-γ) and less myocardial apoptosis (much higher Bcl-2/Bax ratio and lower cleaved caspase-3 expression). Moreover, IL-33 activated the P38 MAPK signaling pathway (up-regulating P-P38 expression) in myocardial tissue, and SB230580 partially attenuated the anti-inflammatory and anti-apoptosis effects of IL-33. These findings indicated that IL-33 protects against myocardial I/R injury by inhibiting inflammatory responses and myocardial apoptosis, which may be associated with the HMGB1 and P38 MAPK signaling pathways.

Interleukin 33 prevents myocardial ischemia and reperfusion injury in rats by activating P38-MAPK pathway / 实用医学杂志

Objective To investigate the protective mechanism of Interleukin 33 (IL-33) in preventing myocardial ischemia and reperfusion injury in rats. Methods A rat model with myocardial I/R with 32the adult male SD rats , which were randomly divided into 4 groups: SO group , I/R group , IL-33 + I/R group , SB230580 + IL-33 + I/R group. The levels of LDH, CK, TNF-α, IL-6, HMGB1, Bcl-2, total caspase-3, cleaved caspase-3 and P-P38 were detected. Results After reperfusion, IL-33 significantly decreased the levels of serum LDH and CK and the expression of TNF-α, IL-6 , cleaved caspase-3 , but significantly increased the expressions of Bcl-2, p-P38 (P < 0.05). SB230580 attenuated the protective role of IL-33 on myocardial I/R in a certain degree. Conclusions IL-33 may prevent myocardial I/R injury via inhibiting inflammation and cardiocyteapoptosis by way of P38 MAPK signaling pathway.