Resveratrol preconditioning protects hepatocytes against hepatic ischemia reperfusion injury via Toll-like receptor 4/nuclear factor-κB signaling pathway in vitro and in vivo.

The purpose of this study was to investigate the protective effect of resveratrol against hepatic ischemia reperfusion injury (HIRI) and explore the potential underlying mechanism. Resveratrol-pretreated BRL-3A (rat liver) cells and rats underwent hypoxia/reoxygenation and hepatic ischemia/reperfusion, respectively. BRL-3A cell damage was evaluated, and the mRNA and protein expression of related signal molecules was assessed in cell model. The protein expression of related signal molecules was also assessed in rat model. Inflammatory cytokines levels were determined in the cell supernatant and rat serum while rat liver function and hepatocyte apoptosis were assessed. The results revealed that resveratrol significantly enhanced cell viability, inhibited cell apoptosis, and decreased levels of lactate dehydrogenase (LDH) and production of tumor necrosis factor-α (TNF-α) and interleukin-(IL)-1β in the cell supernatant. In addition, resveratrol ameliorated elevated Toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB, and the depressed inhibitor of NF-κB (IκB)-α caused by hypoxia/reoxygenation stimulation in BRL-3A cells. Moreover, resveratrol inhibited the translocation of NF-κB p65 after the stimulation of hypoxia/reoxygenation in BRL-3A cells. In vivo assays revealed that resveratrol reduced levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and liver pathological changes, while it alleviated hepatocyte apoptosis, negatively mediated the production of TNF-α and IL-1β in serum, and reversed TLR4/NF-κB signaling pathway caused by hepatic ischemia/reperfusion stimulation in liver tissues. The results indicate that resveratrol protected hepatocytes against HIRI, which may be mediated in part via the TLR4/NF-κB signaling pathway.

He D ，Guo Z ，Pu JL ，Zheng DF ，Wei XF ，Liu R ，Tang CY ，Wu ZJ ... -  《-》

The protective effect of Luteolin on myocardial ischemia/reperfusion (I/R) injury through TLR4/NF-κB/NLRP3 inflammasome pathway.

The purpose of the present study was to investigate the effect of Luteolin(Lut) on myocardial ischemia reperfusion injury and explore the underlying mechanism. Myocardial ischemia reperfusion injury (I/R) model was induced with 30min of left anterior descending (LAD) occlusion followed by 24h of reperfusion. In vivo, the rats were randomly divided into 5 groups: (1)Sham, (2)I/R, (3)I/R+Lut(40mg/kg), (4)I/R+Lut(80mg/kg) and (5)I/R+Lut(160mg/kg). In vitro, the H9c2 cells were assigned to five groups: (1)control, (2)hypoxia-reoxygenation(H/R), (3)H/R+Lut(5μM), (4)H/R+Lut(10μM) and (5)H/R+Lut(20μM). The H9c2 cells were stimulated with H/R protocol in the presence or absence of TAK-242, a TLR4 inhibitor. As a result, Lut ameliorated myocardial ischemia reperfusion injury and hypoxia-reoxygenation as evidenced by triphenyl tetrazolium chloride (TTC) staining and MTT assay, respectively. Lut was founded to decrease the levels of aspartate transaminase(AST), creatine phosphokinase-isoenzyme (CK-MB) and lactate dehydrogenase (LDH) in serum. Moreover, Lut could reduce the contents of interleukin-1β(IL-1β), interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) in serum of rats and supernant of H9c2 cells. In addition, Lut remarkably downregulated the expressions of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor kappa B (NF-κB). Lut also inhibited the upregulations of inflammasome components, such as NOD-like receptor 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC) in I/R-induced rats and H/R-induced H9c2 cells. In conclusion, Lut exhibited strong favorable cardioprotective effect on myocardial I/R injury which might be related to the down-regulation of the TLR4-meidated NF-κB/NLRP3 inflammasome in vivo and in vitro.

Zhang X ，Du Q ，Yang Y ，Wang J ，Dou S ，Liu C ，Duan J ... -  《-》

Dexmedetomidine Protects Rat Liver against Ischemia-Reperfusion Injury Partly by the α2A-Adrenoceptor Subtype and the Mechanism Is Associated with the TLR4/NF-κB Pathway.

Wang Y ，Wu S ，Yu X ，Zhou S ，Ge M ，Chi X ，Cai J ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Plasma membrane-bound G protein-coupled bile acid receptor attenuates liver ischemia/reperfusion injury via the inhibition of toll-like receptor 4 signaling in mice.

The plasma membrane-bound G protein-coupled bile acid receptor (TGR5) displays varied levels of expression in different tissues. TGR5-induced liver protection has been demonstrated during several liver diseases, except during ischemia/reperfusion injury (IRI). Male adult wild-type and TGR5 knockout (KO) mice were subjected to liver partial warm ischemia/reperfusion. Hepatic injury was evaluated based on serum alanine aminotransferase and serum aspartate aminotransferase. Liver histological injury and inflammatory cell infiltration were evaluated in tissue sections using liver immunohistochemical analysis. We used quantitative real-time polymerase chain reaction to analyze the liver expression of inflammatory cytokines. The toll-like receptor 4 (TLR4) signaling pathway and its related apoptotic molecules were investigated after reperfusion. Moreover, the effect of TGR5 on inflammation was determined with TGR5+/+ or TGR5-/- primary bone marrow-derived macrophages in vitro. TGR5 significantly attenuated liver damage after IRI. As demonstrated by in vivo experiments, TGR5 significantly reduced the up-regulation of the TLR4-nuclear factor kappa B (NF-κB) pathway and inhibited caspase 8 activation after IRI. Later experiments showed that TGR5 KO significantly increased the expression of TLR4-NF-κB signaling molecules and promoted hepatocellular apoptosis. In addition, in vitro experiments showed that overexpression of 6alpha-ethyl-23(S)-methylcholic acid (INT-777)-activated TGR5 directly down-regulated tumor necrosis factor α (TNF-α) and interleukin (IL) 6 expression but up-regulated IL10 expression in hypoxia/reoxygenation-induced primary TGR5+/+ macrophages. Moreover, the expression of TLR4-NF-κB signaling molecules was significantly inhibited by the activation of TGR5. Importantly, these results were completely reversed in primary TGR5-/- macrophages. This work is the first to provide evidence for a TGR5-inhibited inflammatory response in IRI through suppression of the TLR4-NF-κB pathway, which may be critical in reducing related inflammatory molecules and modulating innate inflammation. Liver Transplantation 23:63-74 2017 AASLD.

Yang H ，Zhou H ，Zhuang L ，Auwerx J ，Schoonjans K ，Wang X ，Feng C ，Lu L ... -  《-》

[Fisetin alleviates hypoxia/reoxygenation injury in rat hepatocytes via modulation of TLR4/NF-κB signaling pathway].

Pu J ，Wan L ，Zheng D ，Wei X ，Wu Z ，Tang C ... -  《-》