Effect and Mechanism of Portal Blood Stasis Removal on Intestinal Endotoxemia and Hepatic Ischemia Reperfusion Injury

The Protective Effect of Magnesium Lithospermate B on Hepatic Ischemia/Reperfusion via Inhibiting the Jak2/Stat3 Signaling Pathway

Acute inflammation is an important component of the pathogenesis of hepatic ischemia/reperfusion injury (HIRI). Magnesium lithospermate B (MLB) has strong neuroprotective and cardioprotective effects. The purpose of this study was to determine whether MLB had underlying protective effects against hepatic I/R injury and to reveal the potential mechanisms related to the hepatoprotective effects. In this study, we first examined the protective effect of MLB on HIRI in mice that underwent 1 h ischemia followed by 6 h reperfusion. MLB pretreatment alleviated the abnormal liver function and hepatocyte damage induced by I/R injury. We found that serum inflammatory cytokines, including IL-6, IL-1β, and TNF-α, were significantly decreased by MLB during hepatic ischemia/reperfusion (I/R) injury, suggesting that MLB may alleviate hepatic I/R injury via inhibiting inflammatory signaling pathways. Second, we investigated the protein level of p-Jak2/Jak2 and p-Stat3/Stat3 using Western blotting and found that MLB could significantly inhibit the activation of the Jak2/Stat3 signaling pathway, which was further verified by AG490 in a mouse model. Finally, the effect of MLB on the Jak2/Stat3 pathway was further assessed in an in vitro model of RAW 264.7 cells; 1 µg/ml LPS induced the secretion of inflammatory mediators, including IL-6, TNF-α, and activation of the Jak2/Stat3 signaling pathway. MLB significantly inhibited the abnormal secretion of inflammatory factors and the activation of the Jak2/Stat3 signaling pathway in RAW264.7 cells. In conclusion, MLB was found for the first time to reduce inflammation induced by hepatic I/R via suppressing the Jak2/Stat3 pathway.

Transplantation of bone marrow mesenchymal stem cells alleviates hepatic ischemia-reperfusion injury in rats

AIM: To assess the therapeutic effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) on hepatic ischemia-reperfusion injury (HIRI) in rats and explore the underlying mechanism.

METHODS: BMSCs were isolated from bone tissues of SD rats, cultured, and identified. SD rats were randomly divided into three groups: a control group, an HIRI group and a BMSCs transplantation group. HIRI was induced by the pringle occlusion method. After hepatic ischemia-reperfusion injury induction, blood samples were taken at 1, 2, and 3 weeks. Serum alanine transaminase (ALT), aspartate transaminase (AST), malondialdehyde (MDA), superoxide dismutase (SOD), interleukin (IL)-18 and tumor necrosis factor-α (TNF-α) were determined. Liver pathological changes were assessed by HE staining after 2 wk. Expression of hepatocyte growth factor (HGF) and alpha-smooth muscle protein (α-SMA) in the liver was detected by RT-PCR and Western blot.

RESULTS: At 1 wk, the levels of serum ALT, AST, IL-18, TNF-α and MDA in the transplantation group and HIRI group were significantly higher than those in the control group (P < 0.05 for all), and the levels of serum SOD were lower than that in the control group (P < 0.05). At 2 wk, the levels of serum ALT, AST, IL-18, TNF-α and MDA in the transplantation group were significantly lower than those in the HIRI group (P < 0.05 for all), but the level of serum MDA was higher and the level of serum SOD was lower in the transplantation group than in the control group (P < 0.05 for both). Hepatic degeneration, necrosis and fibrosis in the transplantation group were reduced significantly compared with the HIRI group (P < 0.05). HGF expression in the liver tissue was significantly higher and α-SMA expression was significantly lower in the transplantation group than in the HIRI group (P < 0.05 for both).

CONCLUSION: Transplantation of BMSCs can alleviate hepatic ischemia-reperfusion injury via mechanism possibly associated with inhibiting inflammatory factors and enhancing anti-oxidation.