Inhibition of glycogen synthase kinase 3b activity regulates Toll-like receptor 4-mediated liver inflammation / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To determine the mechanism underlying the therapeutic activities of glycogen synthase kinase 3b (GSK3b) against hepatic ischemia-reperfusion (H-IR) injury by investigating the inhibitive effects of GSK3b on inflammation mediated by Toll-like receptor 4 (TLR4).</p><p><b>METHODS</b>C57BL/6 male mice were subjected to 90 min of warm liver cephalad lobe ischemia, followed by reperfusion for various lengths of time. The mice were divided into three groups: the H-IR untreated model (control group), and the H-IR inflammation-induced models that received an intraperitoneal injection of purified lipopolysaccharide (LPS) endotoxin alone (inflammation group) or with pretreatment of the SB216763 GSK3b-specific inhibitor (intervention group). To create a parallel isolated cell system for detailed investigations of macrophages, marrow-derived stem cells were isolated from femurs of the H-IR control group of mice and used to derive primary macrophages. The cells were then divided into the same three groups as the whole mouse system: control, LPS-induced inflammation model, and inflammation model with SB216763 intervention. Differential expressions of inflammation-related proteins and genes were detected by Western blotting and real-time quantitative PCR, respectively.</p><p><b>RESULTS</b>The phosphorylation levels of ERK, JNK and p38 MAPK were induced in liver at 1 h after reperfusion, but then steadily decreased and returned to baseline levels by 4 h after reperfusion. In addition, the phosphorylation levels of ERK and JNK were induced in macrophages at 15 min after LPS stimulation, while the phosphorylation level of p38 MAPK was induced at 1 h; SB216763 pretreatment suppressed the LPS-stimulated ERK, JNK and p38 phosphorylation in macrophages. In the mouse model, GSK3b activity was found to promote the gene expression of anti-inflammatory cytokine IL-10 (control: 0.21 ± 0.08, inflammation: 0.83 ± 0.21, intervention: 1.76 ± 0.67; F = 3.16, P = 0.027) but to significantly inhibit the gene expression of pro-inflammatory cytokines IL-12 (control: 0.11 ± 0.05, inflammation: 0.85 ± 0.11, intervention: 0.43 ± 0.10; F = 2.67, P = 0.038), TNF-a, (control: 0.052 ± 0.012, inflammation: 8.11 ± 0.98, intervention: 3.9 ± 0.82; F = 4.13, P = 0.016), IL-6 (control: 0.22 ± 0.08, inflammation: 6.37 ± 0.81, intervention: 2.11 ± 0.63; F = 3.21, P = 0.024), and IL-1b (control: 0.12 ± 0.07, inflammation: 2.51 ± 0.62, and intervention: 1.28 ± 0.33; F = 2.22, P = 0.030).</p><p><b>CONCLUSION</b>Inhibition of GSK3b selectively regulates the expression of anti-inflammatory and pro-inflammatory cytokines in liver Kupffer cells (liver macrophages). This process may be one of the mechanisms underlying the ability of GSK3b to ameliorate hepatic ischemia-reperfusion injury, possibly because inhibition of pro-inflammatory cytokines may indirectly mediate liver cell apoptosis.</p>

The role of glycogen synthase kinase-3 beta in the pathogenesis of liver ischemia reperfusion injury / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the role of the key intracellular signaling molecule glycogen synthase kinase-3 beta in the mechanism of liver ischemia reperfusion (IR).</p><p><b>METHODS</b>C57BL/6 mice were subjected to 90 min warm liver cephalad lobe ischemia, followed by various length of reperfusion. Experiment groups included sham control group, liver IRI model group and glycogen synthase kinase-3 beta inhibitor-treated group (SB216763 in DMSO, 25 g/kg, i.p, 2 hour prior to the onset of liver ischemia). The expression of glycogen synthase kinase-3 beta protein was analysed by Western blotting. The serum ALT levels were determined to reflect the function of liver. The affected liver lobes were harvested for histology analysis. The inflammatory gene expression was detected by Quantitative PCR.</p><p><b>RESULTS</b>By western blot analysis, we found that ischemia itself activated glycogen synthase kinase-3 beta by a significant decrease of its phosphorylation. Glycogen synthase kinase-3 beta inhibitor SB216763-pretreatment ameliorated the liver damages significantly as compared to the controls (sALT: 2046+/-513 U/L vs 5809+/-1689 U/L, P = 0.0153), and suppressed the gene expressions of IL-12, TNFa, IL-1b and IL-6.</p><p><b>CONCLUSIONS</b>This study demonstrated that the ischemia process modulated liver innate immune activation via a GSK-3-dependent mechanism which favored the development of a pro-inflammation response and lead to liver tissue damages. GSK-3b may be a new therapeutic target to ameliorate liver IRI in transplant patients.</p>

The approaches for making acute-on-chronic liver failure in rat / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the approaches for making acute-on-chronic hepatic failure model in rat.</p><p><b>METHODS</b>SD rats were intraperitoneally injected with 50% CCl4 (Carbon tetrachloride) olive solution every three days for 6 or 10 weeks. Then they were divided into two groups randomly and injected with D-galactosamine (D-gal) at a dose of 2 g/kg, lipopolysaccharide (LPS) at a dose of 100 pg/kg and D-gal at a dose of 0.5 g/kg BW respectively. The levels of serum ALT, AST and TBil were detected,and histopathological changes were observed to evaluate these two models.</p><p><b>RESULTS</b>After injection of 50% CCl4 olive solution intraperitoneally for 6 weeks, liver fibrosis happened in SD rats, 10 weeks, cirrhosis happened. Pelleta necrosis and massive or submassive necrosis was seen administration of two reagents mentioned above.</p><p><b>CONCLUSION</b>By injecting of 50% CCl4 olive solution intraperitoneally, acute-on-chronic liver failure model could be induced by D-gal, LPS/D-gal in rats.</p>