Influence of IL-33 on ROS generation in neonatal rats during anoxia/reoxygenation-induced myocardial injury

Abstract

Objective To investigate the protective effect of interleukin-33 (IL-33) on anoxia/reoxygenation (A/R)-induced injury and its influence on reactive oxygen species (ROS) generation in neonatal rats. Methods Primary cardiomyocytes were isolated from neonatal Sprague-DawIey rats and were randomly divided into 6 groups: control group, control + rIL-33 100 ng/ml group, A/R group and A/R+ rIL-33 (1, 10, 100 ng/ml) groups. A/R group and A/R+ rIL-33 are subjected to 3 hours of anoxia, followed by 2 hours reoxygenation. Cardiomyocytes were identified by immunocytochemical staining. The viability of the cells was examined by MTT assay. The level of lactate dehydrogenase (LDH) was detected by a LDH enzyme linked immunosorbent assay (ELISA) kit. The apoptosis of the cardiomyocytes was observed via flow cytometry (Annexin V and propidiom iodide double staining method), ROS levels were measured by ROS fluorescent probe-dihydroethidium (DHE). Results Compared with control group, the apoptosis rate of the cardiomyocytes, level of LDH and ROS were remarkably increased (all P<0.01), the viability of cardiomyocytes was impaired significantly in A/R group (P<0.01). Compared with A/R group, the apoptosis rate of the cardiomyocytes (P<0.01), level of LDH and ROS production (P=0.03) were significantly decreased (P<0.01), and the viability of cardiomyocytes enhanced significantly in rIL-33 (1, 10, 100 ng/ml) groups in a dose-dependent manner (all P<0.01) . There was no significant difference between control group and control + rIL-33 100 ng/ml group. Conclusions IL-33 prevents apoptosis and improves survival during the anoxia/reoxygenation-induced cardiomyocyte injury, which may be due to the effects of anti-oxidative mechanism and reduce ROS generation. Key words: Interleukin-33; Reactive oxygen species; Myocytes, cardiac; Anoxia/reoxygenation-induced injury