Genetic association of interleukin-6 polymorphism (-174 G/C) with chronic liver diseases and hepatocellular carcinoma

Interleukin-6 (IL-6) is a pleiotropic cytokine which is expressed in many inflammatory cells in response to different types of stimuli, regulating a number of biological processes. The IL-6 gene is polymorphic in both the 5' and 3' flanking regions and more than 150 single nucleotide polymorphisms have been identified so far. Genetic polymorphisms of IL-6 may affect the outcomes of several diseases, where the presence of high levels of circulating IL-6 have been correlated to the stage and/or the progression of the disease itself. The -174 G/C polymorphism is a frequent polymorphism, that is located in the upstream regulatory region of the IL-6 gene and affects IL-6 production. However, the data in the literature on the genetic association between the -174 G/C polymorphism and some specific liver diseases characterized by different etiologies are still controversial. In particular, most of the studies are quite unanimous in describing a correlation between the presence of the high-producer genotype and a worse evolution of the chronic liver disease. This is valid for patients with hepatitis C virus (HCV)-related chronic hepatitis and liver cirrhosis and hepatocellu-lar carcinoma (HCC) whatever the etiology. Studies in hepatitis B virus-related chronic liver diseases are not conclusive, while specific populations like non alcoholic fatty liver disease/non-alcoholic steatohepatitis, autoimmune and human immunodeficiency virus/HCV coinfected patients show a higher prevalence of the lowproducer genotype, probably due to the complexity of these clinical pictures. In this direction, a systematic revision of these data should shed more light on the role of this polymorphism in chronic liver diseases and HCC.

Antioxidant axis Nrf2-keap1-ARE in inhibition of alcoholic liver fibrosis by IL-22

AIM To explore the effect of interleukin(IL)-22 on in vitro model of alcoholic liver fibrosis hepatic stellate cells(HSCs), and whether this is related to regulation of Nrf2-keap1-ARE.METHODS HSC-T6 cells were incubated with 25, 50, 100, 200 and 400 μmol/L acetaldehyde. After 24 and 48 h, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was used to detect proliferation of HSCs to choose the best concentration and action time. We used the optimal concentration of acetaldehyde(200 μmol/L) to stimulate HSCs for 24 h, and treated the cells with a final concentration of 10, 20 or 50 ng/m L IL-22. The cell proliferation rate was detected by MTT assay. The cell cycle was analyzed by flow cytometry. The expression of nuclear factor-related factor(Nrf)2 and α-smooth muscle antigen was detected by western blotting and immunocytochemistry. The levels of malondialdehyde(MDA) and glutathione(GSH) were measured by spectrophotometry. RESULTS In the MTT assay, when HSCs were incubated with acetaldehyde, activity and proliferation were higher than in the control group, and were most obvious after 48 h treatment with 200 μmol/L acetaldehyde. The number of cells in G0/G1 phases was decreased and the number in S phase was increased in comparison with the control group. When treated with different concentrations of IL-22, HSC-T6 cell activity and proliferation rate were markedly decreased in a dosedependent manner, and cell cycle progression was arrested from G1 to S phase. Western blotting and immunocytochemistry demonstrated that expression of Nrf2 total protein was not significantly affected. Expression of Nrf2 nuclear protein was low in thecontrol group, increased slightly in the model group(or acetaldehyde-stimulated group), and increased more obviously in the IL-22 intervention groups. The levels of MDA and GSH in the model group were significantly enhanced in comparison with those in the control group. In cells treated with IL-22, the MDA level was attenuated but the GSH level was further increased. These changes were dose-dependent. CONCLUSION IL-22 inhibits acetaldehyde-induced HSC activation and proliferation, which may be related to nuclear translocation of Nrf2 and increased activity of the antioxidant axis Nrf2-keap1-ARE.

Expression of cyclooxygenase-2 and its pathogenic effects in nonalcoholic fatty liver disease

Objective：To investigate the expression of cyclooxygenase-2 and its pathological effect in the experimental nonalcoholic fatty liver of rats, and to explore its possible mechanism. Methods：The rat NAFLD model was established by giving a fat-enriched diet. The blood samples were obtained form abdominal aorta and the levels of serum ALT, AST and IL-1, changes in the hepatic tissue 6-k-PGF1 α TXB2 were measured. The expression level of COX-2 in rats livers were assayed by immunohistochemistry, RT-PCR and Westernblot. Results： Light microscope analysis revealed that hepatocytes were injured in the model group and slightly in the treatment group. The levels of serum TXB2 and IL-1 in the fatty liver rats were increased. Compared with the model group, the IL-1 and TXB2 increased significantly（P〈 0.05）, on the contrary, compared with the normal group, the hepatic tissue 6-Keto-prostagland decreased significantly in the model group（P 〈 0.05）, the treatment group also increased but P 〉 0.05. There was no positive expression of COX-2 in hepatic tissue of normal rats. In the model group, there was positive expression of COX-2 antigen and the number of COX positive cells progressively increased at 4, 8, 12 wks. The intensity of expression of COX-2 had significantly increased（P 〈 0.05 ） and the intensity of COX-2 expression in the treated group decreased remarkably compared with the model group（P 〈 0.05）. The expression of COX-2 mRNA and the level of COX-2 protein were significantly stronger in the liver of model rats compared with normal rats, and significantly weaker in treated rats, than in 8W and 12W model rats（P 〈 0.05）. Conclusion：The increase of COX-2 expression in NAFLD is closely associated with the severity of liver inflammation and damage. COX-2 may play an important role in the progression of rat NAFLD, and the expression of COX-2 mRNA is downregulated by cyclooxygenase-2 inhibitor, which can depress the oxidative stress and control inflammatory response efficiently.

酒精性肝硬化病人白细胞介素6及其与白细胞介素2相关性研究

目的 :研究酒精性肝硬化病人白细胞介素 6及其与白细胞介素 2相关性。方法 :应用ELISA方法分别检测了酒精性肝硬化病人血清白细胞介素 6 (IL - 6 )及外周血单核细胞 (PBMC)自然和诱导产生的IL - 6和IL - 2水平 ,同时观察了诱导产生的IL - 6与免疫球蛋白IgA、IgG及IL - 2的相关性。结果 :血清中和PBMC自然或诱导产生的IL - 6均明显高于健康对照组 ,IL - 6与血清IgA水平呈正相关 ,与IL - 2呈负相关。结论

Therapeutic effect of interleukin-10 on CCI_4-induced hepatic fibrosis in rats

AIM： To study the therapeutic effect of exogenous interleuldn-10 on CCl4-induced hepatic fibrosis in rats and its passible mechanisms. METHODS： Fourty-seven SD rats were randomly divided into control group （group N） and CCl4-induced hepatic fibrosis model group （group C）. After CCl4 was given for 9 wk, the model group was divided into three groups. Rats in group H were put to death immediately, rats in group T were treated with IL-10 for another three wk and then put to death, rats in group R recovered after three weeks and were then killed. The degree of hepatic fibrosis was measured by HE staining and histological activity index （HAI）. Histological activity index （HAI）, change of collagen types Ⅰ and Ⅲ were measured by Picrosirius staining. The expression of TNF-α, HHP-2 and TIMP-1 in liver tissue was measured by S-P immunohis tochemistry.RESULTS： CCl4- induced experimental rat hepatic fibrosis model was established successfully. The degree of hepatic fibrosis was markedly lower in group T than in groups H and R, and there was no difference between the two groups. The expression of collagen types I and III was significantly suppressed in group T and was slightly suppressed in groups H and R. The positive levels of TNF-α, HHP-2 and TIHP-1 in group H increased significantly compared to those in group N （P〈0.01）. The positive signals decreased significantly in groups T and R （P〈0.01）, but positive score was significantly lower in group T than in group R （P〈 0.01）. CONCLUS10N： Exogenous IL-10 can reverse CCl4-induced hepatic fibrosis in rats. IL-10 may exert its reversible effects on hepatic fibrosis by blocking CCl4-induced inflammation, inhibiting expression of HHP-2 and TIMP-1 and promoting resolution of collagen types Ⅰ and Ⅲ.

Liver dysfunction as a cytokine storm manifestation and prognostic factor for severe COVID-19

patients with or without preexisting liver disorders,posing a significant complication and mortality risk.During coronavirus disease 2019(COVID-19),abnormal liver function is typically observed.However,liver injury may occur because of the treatment as well.Ischemia,cytokine storm,and hypoxia were identified as the three major factors contributing to liver damage during COVID-19.Indeed,raised liver enzymes during hospitalizations may be attributed to medications used,as well as sepsis and shock.As a result,the proportion of hospitalized patients afflicted with COVID-19 and pathological liver biomarkers varies from 14%to 53%.Aminotransferases and bilirubin are found most often elevated.Usually,increased gamma-glutamyltransferase,alkaline phosphatase,and decreased serum albumin levels are demonstrated.Additionally,although there is no specific treatment for COVID-19,many of the drugs used to treat the infection are hepatotoxic.In this mini-review,we focus on how liver dysfunction can be one of the features associated with the COVID-19 cytokine storm.Furthermore,data show that liver injury can be an independent predictor of severe COVID-19,the need for hospitalization,and death.

I_κB kinase-beta inhibitor attenuates hepatic fibrosis in mice

AIM: To investigate the anti-fibrosis effect of IκB kinase-beta inhibitor (IKK2 inhibitor IMD0354) in liver fibrosis. METHODS: Twenty male C57BL6 mice were divided into four groups. Five high-fat fed mice were injected with lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally and five high-fat fed mice were without LPS injection to build models of liver injury, and the intervention group (five mice) was injected intraperitoneally with IKK2 inhibitor (IMD 30 mg/kg for 14 d), while the remaining five mice received a normal diet as controls. Hepatic function, pathological evaluation and liver interleukin-6 (IL-6) expression were examined. Western blotting and real-time polymerase chain reaction were used to detect the expressions of nuclear factor-κB (NF-κB), alpha-smooth muscle actin (α-SMA), tumor growth factor-beta1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), typeⅠand type Ⅲ collagen proteins and mRNA. RESULTS: A mouse model of liver injury was successfully established, and IMD decreased nuclear transloca-tion of NF-κB p65 in liver cells. In the IMD-treated group, the levels of alanine aminotransferase (103 ± 9.77 μ/L vs 62.4 ± 7.90 μ/L, P < 0.05) and aminotransferase (295.8 ± 38.56 μ/L vs 212 ± 25.10 μ/L, P < 0.05) were significantly decreased when compared with the model groups. The histological changes were significantly ameliorated. After treatment, the expressions of IL-6 (681 ± 45.96 vs 77 ± 7.79, P < 0.05), TGF-β1 (Western blotting 5.65% ± 0.017% vs 2.73% ± 0.005%, P < 0.05), TNF-α (11.58% ± 0.0063% vs 8.86% ± 0.0050%, P < 0.05), typeⅠcollagen (4.49% ± 0.014% vs 1.90% ± 0.0006%, P < 0.05) and type Ⅲ collagen (3.46% ± 0.008% vs 2.29% ± 0.0035%, P < 0.05) as well as α-SMA (6.19 ± 0.0036 μ/L vs 2.16 ± 0.0023 μ/L, P < 0.05) protein and mRNA were downregulated in the IMD group compared to the fibrosis control groups (P < 0.05). CONCLUSION: IKK2 inhibitor IMD markedly improved non-alcoholic fatty liver disease in mice by lowering NF-κB activation, which could become a remedial target for liver fibrosis.