Myocardial ischemic post-conditioning protects the lung against myocardial ischemia/reperfusion-induced damage by activating GSK-3

Purpose: To investigate whether modulating GSK-3 could attenuate myocardial ischemia reperfusion injury (MIRI) induced acute lung injury (ALI) and analyze the underlying mechanism. Methods: Male SD rats were subjected to MIRI with or without myocardial ischemic post-conditioning in the presence or absence of GSK-3 inhibitor. GSK-3 inhibitor was injected peritoneally 10min before MIRI. Lung W/D weight ratio, MPO, PMNs, histopathological changes, TUNEL, Bax, Bcl-2, IL-6, IL-8, IL-10, GSK-3, and caspase-3 were evaluated in the lung tissues of all rats. Results: After MIRI, lung injury was significantly increased manifested as significant morphological changes and increased leukocytes in the interstitial capillaries, Lung W/D ratio, MPO, and PMN in BALF, which was associated with enhanced inflammation evidenced by increased expressions of IL-6, IL-8 and reduced expression of IL-10. MIRI significantly increased cell apoptosis in the lung as increased levels of apoptotosis, Bax, cleaved caspase-3, and reduced expression of Bcl-2 was observed, which was concomitant with reduced p-GSK-3. All these changes were reversed/prevented by ischemic post-conditioning, while these beneficial effects of ischemic post-conditioning were abolished by GSK-3 inhibition. Conclusion: Myocardial ischemia reperfusion injury induces acute lung injury by induction of inflammation and cell apoptosis. Ischemic post-conditioning protects the lung from ALI following MIRI by increasing p-GSK-3.(AU)

The role of histone deacetylase inhibitors in regulation of Akt/GSK-3 signaling pathway in mice following transient focal cerebral ischemia

Purpose: To investigate whether the neuroprotective effect of TSA on cerebral ischemia reperfusion injury is mediated by the activation of Akt/GSK-3 signaling pathway. Methods: Mice were randomly divided into four groups (n=15): sham group (S); ischemia reperfusion group (IR); ischemia reperfusion and pretreated with TSA group (IR+T); ischemia reperfusion and pretreated with TSA and LY294002 group (IR+T+L). The model of cerebral ischemia reperfusion was established by 1h of MCAO following 24h of reperfusion. TSA (5mg/kg) was intraperitoneally given for 3 days before MCAO, Akt inhibitor, LY294002 (15 nmol/kg) was injected by tail vein 30 min before the MCAO. Results: TSA significantly increased the expression of p-Akt, p-GSK-3 proteins and the levels of SOD, Bcl-2, reduced the infarct volume and the levels of MDA, ROS, TNF-, IL-1, Bax, Caspase-3, TUNEL and attenuated neurological deficit in mice with transient MCAO, LY294002 weakened such effect of TSA dramatically. Conclusions: TSA could significantly decrease the neurological deficit and reduce the cerebral infarct volume, oxidative stress, inflammation, as well as apoptosis during cerebral ischemia reperfusion injury, which was achieved by activation of the Akt/GSK-3 signaling pathway.(AU)