15-Deoxy-Δ^12,14-prostaglandin J₂ alleviates hepatic ischemia-reperfusion injury in mice via inducing antioxidant response and inhibiting apoptosis and autophagy

Hepatic ischemia-reperfusion (I/R) injury is a common clinical impairment that occurs in many circumstances and leads to poor prognosis. Both apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. 15-Deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ2) is one of the best-studied anti-inflammatory prostaglandins, which has been verified to exert anti-inflammatory and cell-protective functions in various types of cells and animal models. In this study we explored the effects of 15d-PGJ2 on both apoptosis and autophagy in mouse hepatic I/R injury and its possible mechanisms. A model of segmental (70%) hepatic warm ischemia was established in Balb/c mice, and the pathological changes in serum and liver tissues were detected at 6, 12, and 24 h post-surgery, while 15d-PGJ2 (2.5, 7.5, 15 μg, iv) was administered 30 min prior the surgery. Pretreatment with 15d-PGJ2 (7.5, 15 μg) significantly ameliorated I/R-induced hepatic injury evidenced by dose-dependent reduction of serum ALT and AST levels as well as alleviated tissue damages. 15d-PGJ2 pretreatment significantly decreased the serum TNF-α and IL-1β levels and the hepatic expression of F4/80, a major biomarker of macrophages. 15d-PGJ2 pretreatment upregulated the Bcl-2/Bax ratio, thus reducing the number of apoptotic cells in the livers. 15d-PGJ2 pretreatment considerably suppressed the expression of Beclin-1 and LC3, thus decreasing the number of autophagosomes in the livers. Furthermore, 15d-PGJ2 pretreatment activated Nrf2 and inhibited a ROS/HIF1α/BNIP3 pathway in the livers. Pretreatment with the PPARγ receptor blocker GW9662 (2 μg, ip) partly reversed the protective effects of 15d-PGJ2 on hepatic I/R injury. In conclusion, our results confirm the protective effect of 15d-PGJ2 on hepatic I/R injury, an effect that may rely on a reduction in the activation of Kupffer cells and on activation of the Nrf2 pathway, which lead to inhibition of ROS generation, apoptosis, and autophagy.