丹参酮IIA对CCl4诱导小鼠急性肝损伤的保护作用

目的 研究丹参酮IIA(tanshinone ⅡA, Tan ⅡA)对CCl4诱导小鼠急性肝损伤的抗氧化、保护作用及其可能的作用机制。 方法 将C57BL/6J小鼠随机分成正常组、CCl4组以及Tan ⅡA保护组(Tan ⅡA 20 mg/kg+CCl4),每组10只。腹腔注射CCl4构建小鼠急性肝损伤模型。计算各组小鼠的肝脏指数,检测血清AST和ALT活性,测定肝组织SOD活性及GSH、MDA含量,HE染色观察肝组织病理变化,免疫组织化学法和Western blot检测肝组织PI3K、p-PI3K、Akt、p-Akt、Nrf2和HO-1蛋白表达水平。 结果 与CCl4组相比,Tan ⅡA保护组肝脏指数显著下降(P<0.01),血清AST(P<0.01)和ALT活性降低(P<0.05),肝组织SOD活性(P<0.01)及GSH含量升高(P<0.05),MDA含量降低(P<0.05),肝组织病理变化得到显著改善。同时,Tan ⅡA使肝组织p-PI3K和p-Akt表达水平明显升高(P<0.01),显著诱导Nrf2转位入核(P<0.01),促使其下游靶蛋白HO-1表达水平明显升高(P<0.01)。 结论 Tan ⅡA能够显著改善CCl4诱导的急性肝损伤,其机制可能与PI3K/Akt/Nrf2/HO-1信号通路有关。     

金丝桃苷对CCl4诱导大鼠急性肝损伤抗氧化应激研究

目的研究金丝桃苷（Hyp）对四氯化碳（CCI。）诱导大鼠急性肝损伤的治疗作用。方法采用大鼠CCl4急性肝损伤模型,观察Hyp对急性肝损伤大鼠肝脏组织病理学改变的影响;检测肝组织匀浆中超氧化物歧化酶（T-SOD）、谷胱甘肽（GSH）的活性及丙二醛（MDA）含量变化。结果CCl4模型组大鼠肝组织HE染色病理检测结果见明显炎症变性死及纤维组织增生现象;Hyp高剂量60mg／kg、中剂量30mg／kg治疗组的肝组织病理改变明显改善;Hyp治疗组肝组织中T—SOD、GSH活性明显升高,MDA含量明显降低,并存在量效关系。结论Hyp对CCl4引起的大鼠急性肝损伤有较好的治疗作用,其机制可能与其抗氧化活性有关。     

Increased carbon tetrachloride-induced liver injury and fibrosis in FGFR4-deficient mice

Carbon tetrachloride (CCl(4)) intoxification in rodents is a commonly used model of both acute and chronic liver injury. Recently, we showed that mice in which FGFR4 was ablated from the germline exhibited elevated cholesterol metabolism and bile acid synthesis coincident with unrepressed levels of cytochrome P450 7A (CYP7A), the rate-limiting enzyme in cholesterol disposal. Of the four fibroblast growth factor (FGF) receptor genes expressed in adult liver, FGFR4 is expressed specifically in mature hepatocytes. To determine whether FGFR4 plays a broader role in liver-specific metabolic functions, we examined the impact of both acute and chronic exposure to CCl(4) in FGFR4-deficient mice. Following acute CCl(4) exposure, the FGFR4-deficient mice exhibited accelerated liver injury, a significant increase in liver mass and delayed hepatolobular repair. Chronic CCl(4) exposure resulted in severe fibrosis in livers of FGFR4-deficient mice compared to normal mice. Analysis at both mRNA and protein levels indicated an 8-hour delay in FGFR4-deficient mice in the down-regulation of cytochrome P450 2E1 (CYP2E1) protein, the major enzyme whose products underlie CCl(4)-induced injury. These results show that hepatocyte FGFR4 protects against acute and chronic insult to the liver and prevents accompanying fibrosis. The results show that FGFR4 acts by promotion of processes that restore hepatolobular architecture rather than cellularity while limiting damage due to prolonged CYP2E1 activity.     

Protective effect of xanthohumol on toxin-induced liver inflammation and fibrosis

Xanthohumol, the major prenylated chalcone found in hops, is known for its anti-inflammatory properties. We have recently shown that xanthohumol inhibits hepatic inflammation and fibrosis in a murine model of nonalcoholic steatohepatitis. The aim of this study was to investigate the effect of xanthohumol in an acute model of liver injury. Carbon tetrachloride (CCl(4)), an industrial solvent, is a hepatotoxic agent and its administration is widely used as an animal model of toxin-induced liver injury. Xanthohumol was applied orally at a dose of 1 mg/g body weight 2 days prior as well as during and after exposure to CCl(4). 72 h after a single CCl(4) application histomorphology and serum levels of transaminases revealed considerable hepatocellular necrosis, which was accompanied by significantly enhanced hepatic expression of pro-inflammatory cytokines. Furthermore, elevated hepatic alpha-smooth muscle actin expression indicated activation of hepatic stellate cells, and in accordance, we detected enhanced hepatic expression levels of TGF-β and collagen type I reflecting a marked fibrogenic response to CCl(4) exposure. While the degree of hepatocellular damage in response to CCl(4) was similar in mice which received xanthohumol and the control group, pro-inflammatory and profibrogenic hepatic gene expression were almost completely blunted in xanthohumol fed mice. Furthermore, xanthohumol fed mice revealed decreased hepatic NFκB activity. These results suggest that the protective effects of xanthohumol in this toxic liver injury model involves direct mechanisms related to its ability to block both hepatic inflammation and the activation of hepatic stellate cells, presumable at least in part via decreasing NFκB activity. Thus, this study further indicates the potential of xanthohumol application to prevent or ameliorate the development and progression of liver fibrosis in response to hepatic injury.     

Cross-regulation by TLR4 and T cell Ig mucin-3 determines severity of liver injury in a CCl4-induced mouse model

Acute liver injury is a common pathological basis for a variety of acute liver diseases in the clinic, which can eventually lead to liver fibrosis and even liver failure. In this study, we found that T cell Ig and mucin domain protein 3 (Tim-3) and TLR4 receptors play important roles in CCl4-induced acute liver injury. Tim-3 is a negative regulator that is expressed by T cells and macrophages. Using antibodies against Tim-3 (anti-Tim-3 Ab), we studied the Tim-3 signal in an animal model of acute liver injury and found that a large number of inflammatory factors were upregulated. In vitro experimental data shown that anti-Tim-3 Ab treatment increased interferon-ɣ production by concanavalin A (ConA)-stimulated spleen T cells, and we found that the expression level of interleukin (IL)-6 was increased in a macrophage/spleen T cell coculture system, while administration of galectin-9 (Gal-9, a Tim-3 ligand) reduced the IL-6 production. This indicates the importance of the Tim-3/Gal-9 signalling pathway in maintaining hepatic homeostasis. The Tim-3 signalling pathway inhibits TLR4-mediated NF-κB activity, and an anti-Tim-3 Ab does not affect the liver injury in TLR4-deficient mice. Regulation between Tim-3 and TLR4 determines the severity of liver damage. The negative regulation of Tim-3 reflects the protective mechanisms of patients with impaired liver function, and these results provide important information about innate and adaptive responses in the regulation of liver damage. This finding is potentially important for the study of early liver injury.     

Ginsenoside Rg1 alleviates acute liver injury through the induction of autophagy and suppressing NF-κB/NLRP3 inflammasome signaling pathway

Background: Severe hepatitis is a common cause of chronic or acute liver disease and autophagy might play an important role in cellular response to inflammation and injury. It has been reported that Ginsenoside-Rg1 (G-Rg1) has strong hepatoprotective effects for acute liver injury, but its protective mechanisms have not yet been elucidated. This study aims to explore the detailed molecular mechanisms of G-Rg1 on acute liver injury via autophagy.Methods: The role of G-Rg1 by autophagic induction was studied in the mouse model of acute liver injury which induced by carbon tetrachloride (CCl4). Liver function, inflammatory reaction and apoptosis were detected when autophagy has been inhibited by 3-MA or stimulated by RPA. MCC950 and ATP were applied to investigate the role of NLRP3 inflammasome in acute liver injury. The differential expression of NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β, IL-18, LC3-I, LC3-II, Beclin-1, PINK1 and Parkin have been detected by the quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.Results: G-Rg1 could decrease ALT, AST, TNF-α, IL-1β and IL-6 in mice with CCl4-induced acute liver injury. The change of autophagy and apoptosis after the treatment of 3-MA or RPA demonstrated that the autophagy played a key role in the protective effect of G-Rg1 in acute liver injury. The enhancement of G-Rg1 promoted-autophagy resulted in the significant decrease in NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β and IL-18, which suggesting that NF-κB/NLRP3 inflammasome signaling pathway was associated with the autophagy induced by G-Rg1 in acute liver injury.Conclusion: G-Rg1 ameliorated acute liver injury via the autophagy, which may be related to NF-κB/NLRP3 inflammasome signaling pathway.     

The chemokine receptor CXCR3 limits injury after acute toxic liver damage

Although acute liver failure is a rare disease, its presence is associated with high morbidity and mortality in affected patients. While a contribution of the immune system to the outcome of toxic liver failure is anticipated, functionally relevant immune cell receptors for liver cell damage need to be better defined. We here investigate the relevance of the chemokine receptor CXCR3, which is important for hepatic immune cell infiltration, in a model of experimental acute liver failure. Liver injury was induced by a single intraperitoneal injection of carbon tetrachloride (CCl(4)) in CXCR3(-/-), CCR1(-/-), CCR5(-/-) and wild-type mice. In this model, CXCR3(-/-) mice displayed augmented liver damage compared with all other mouse strains as assessed by liver histology and serum transaminases 24 and 72?h after injury. Phenotypically, CXCR3(-/-) mice had significantly reduced intrahepatic NK and NKT cells after injury at all investigated time points (all P<0.05), but strongly elevated expression levels of IL1-β, TNF-α and IFN-γ. In line with a functional role of innate immune cells, wild-type mice depleted for NK cells with an anti-ASIALO GM1 antibody before liver injury also displayed increased liver injury after CCl(4) challenge. CXCR3(-/-) and NK cell-depleted mice show reduced apoptotic liver cells (TUNEL assay), but more necrotic hepatocytes. Functionally, the augmented liver cell necrosis in CXCR3(-/-) and NK cell-depleted mice was associated with increased expression of high mobility group 1 (HMGB1) protein and a consecutive enhanced infiltration of neutrophils into the liver. In conclusion, the results demonstrate a primarily unexpected beneficial role of CXCR3 in acute toxic liver injury. These findings should be taken into account when planning trials with CXCR3 antagonists.     

敲除Colgalt2基因加重小鼠急性肝损伤

目的：初步探讨Colgalt2基因介导的胶原Glcα1,2 Galβ1?糖基化修饰在急性肝损伤过程中的作用。方法取60只Colgalt2＋／＋小鼠和60只Colgalt2－／－小鼠进行急性肝损伤实验,雌雄各半。每组随机选取20只小鼠腹腔注射CCl4（CCl4∶橄榄油＝2∶7,20 ml／kg）。观察小鼠死亡情况,并绘制生存曲线。每组剩余40只小鼠随机分为0、4、8、12 h组,每组10只,腹腔注射CCl4（剂量同上）。分别于0、4及8 h各处死6只小鼠,之后将4及8 h组剩余的小鼠均纳入12 h组（ Colgalt2＋／＋小鼠, n＝14; Colgalt2－／－小鼠, n＝16）,并于12 h处死小鼠。 HE染色观察肝组织的病理学改变,取血清进行生化指标ALT、 AST测定。利用qRT?PCR和Western印迹技术检测小鼠Colgalt2在基因及蛋白水平的表达情况。结果Colgalt2基因在Col?galt2＋／＋小鼠肝组织内表达,而在Colgalt2－／－小鼠肝组织内不表达。注射CCl4后10 h, Colgalt2＋／＋小鼠死亡率为35％, Colgalt2－／－小鼠死亡率为70％,两组小鼠死亡率差异显著（P＜0．05）。注射CCl4后12 h, Colgalt2＋／＋小鼠死亡率达50％, Colgalt2－／－小鼠死亡率为70％,差异不显著（P＞0．05）。肝功检测及HE染色结果均提示,与Colgalt2＋／＋小鼠相比, Colgalt2－／－小鼠肝损伤较重。注射CCl4后,野生型小鼠Colgalt2在RNA水平和蛋白水平表达下调。结论 Colgalt2基因敲除在一定程度上可加重小鼠急性肝损伤。该观察结果提示, Colgalt2基因介导的胶原Glcα1,2 Galβ1?糖基化修饰可能与肝损伤的修复有关。     

Acute liver toxicity by carbon tetrachloride in HSP70 knock out mice

The effects of carbon tetrachloride (CCl(4)) treatment on acute liver damage in knock out (heat shock proteins -- HSP70-/-) mice and wild-type (C57BL/6) mice were examined. Acute liver injury was induced by a single intraperitoneal injection of 0.3 ML/kg CCl(4) in olive oil. Mice were sacrificed at 12, 24, 48 and 72 h after treatment. To assess hepatotoxicity, alanine transaminase, neutrophil infiltration and degree of necrosis were measured. Western blot analysis was employed for heat shock proteins. The result revealed that HSP70-/- mice showed higher alanine transaminase levels and a more severe degree of neutrophilic infiltration and necrosis than those of wild-type mice. Furthermore, HSP70-/- mice recovered more slowly from CCl(4) treatment. In HSP70-/- mice, HSP47 was overexpressed. Therefore, HSP70-/- mice could be an adequate model of acute liver toxicity study.     

Neutralization of CXCL10 accelerates liver regeneration in carbon tetrachloride-induced acute liver injury

Remodeling of hepatic tissue structure following injury requires the coordinated action of hepatocytes, hepatic stellate cells (HSCs), and endothelial cells. However, their in vivo properties are not fully understood. We report here that the chemokine CXCL10 regulates hepatic tissue remodeling in a carbon tetrachloride (CCl(4))-induced acute liver injury in mice. The production of CXCL10 was enhanced by hepatocytes after CCl(4) exposure. Neutralization of CXCL10 protected mice from acute liver dysfunction and diminished hepatocellular loss. The hepatoprotective effect was associated with increased numbers of 5'-bromo-2' deoxyuridine (BrdU)+ hepatocytes from day 1 and with accumulation of HSCs and endothelial cells within the injured zones from day 3. In vitro, recombinant CXCL10 directly inhibited the proliferation of hepatocytic cells, establishing a novel role of CXCL10 in modulating hepatocyte proliferation, in addition to a previously reported angiostatic role. In summary, neutralization of CXCL10 initially stimulates hepatocyte proliferation and, subsequently, HSC migration and angiogenesis to facilitate remodeling of hepatic cords. Thus, CXCL10 can be a novel therapeutic target for acute hepatocellular damage by regulating liver tissue remodeling.     

Loss of discoidin domain receptor 2 promotes hepatic fibrosis after chronic carbon tetrachloride through altered paracrine interactions between hepatic stellate cells and liver-associated macrophages

Hepatic stellate cells (HSCs) interact with fibrillar collagen through the discoidin domain receptor 2 (DDR2) in acute hepatic injury, generating increased fibrosis. However, the contribution of DDR2 signaling to chronic liver fibrosis in vivo is unclear, despite its relevance to chronic human liver disease. We administered carbon tetrachloride (CCl(4)) to DDR2(+/+) and DDR2(-/-) mice twice weekly, and liver tissues and isolated HSCs were analyzed. In contrast to changes seen in acute injury, after chronic CCl(4) administration, DDR2(-/-) livers had increased collagen deposition, gelatinolytic activity, and HSC density. Increased basal gene expression of osteopontin, transforming growth factor-β1, monocyte chemoattractant protein-1, and IL-10 and reduced basal gene expression of matrix metalloproteinase-2, matrix metalloproteinase-13, and collagen type I in quiescent DDR2(-/-) HSCs were amplified further after chronic CCl(4). In concordance, DDR2(-/-) HSCs isolated from chronically injured livers had enhanced in vitro migration and proliferation, but less extracellular matrix degradative activity. Macrophages from chronic CCl(4)-treated DDR2(-/-) livers showed stronger chemoattractive activity toward DDR2(-/-) HSCs than DDR2(+/+) macrophages, increased extracellular matrix degradation, and higher cytokine mRNA expression. In conclusion, loss of DDR2 promotes chronic liver fibrosis after CCl(4) injury. The fibrogenic sinusoidal milieu generated in chronic DDR2(-/-) livers recruits more HSCs to injured regions, which enhances fibrosis. Together, these findings suggest that DDR2 normally orchestrates gene programs and paracrine interactions between HSCs and macrophages that together attenuate chronic hepatic fibrosis.     

NF-kappa B binding activity and cyclooxygenase-2 expression in persistent CCl(4)-treated rat liver injury

The involvement of NF-kappa B binding activity is known to be important in the mechanism of acute liver injury and in the induction of cyclooxygenase (COX-2). This study was performed to evaluate NF-kappa B binding activity and the expression of COX-2 in chronic liver injury induced by carbon tetrachloride (CCl(4)). Liver tissues from Sprague-Dawley rats were collected at 1, 3, 5, and 7th week after intraperitoneal injection of 0.1 mL of CCl(4)/100 g body weight twice a week. Reactive oxy-gen species (ROS) were measured in the postmitochondrial fraction by dichlorofluorescein formation with a fluorescent probe. An electrophoretic mobility shift assay was performed for NF-kappa B binding activity. Western blot was performed to measure the level of COX-1, COX-2, p65, p50, and I B proteins. ROS and NF-kappa B activity increased during the CCl4-induced chronic liver injury. The expression of nuclear p65 protein and p50 protein increased compared with that of the control, while the cytoplasmic I B protein decreased as the inflammation persisted. The expression of COX-2 in CCl(4)-treated rat liver increased compared with that of the control. It could be suggested that ROS produced by CCl(4) treatment increased NF-kappa B binding activity and thereby COX-2 expression, and these might be implicated in the progress of chronic liver damage.     

Invariant natural killer T-cell-deficient mice display increased CCl₄ -induced hepatitis associated with CXCL1 over-expression and neutrophil infiltration

Invariant natural killer T (iNKT) cells are involved in the intrahepatic immune response and in hepatitis. In particular, iNKT lymphocytes are responsible for hepatocyte death in concanavalin A-induced hepatitis in mice. We examined the role of iNKT cells in acute hepatitis induced by a hepatotoxic agent, carbon tetrachloride (CCl(4) ). WT and iNKT cell-deficient (Jα18(-/-) ) mice were challenged with a single dose of 2.4 g/kg CCl(4) and both hepatic physiopathology and immune responses were studied. Plasma alanine and aspartate amino-transferase levels were significantly higher in Jα18(-/-) mice than in WT mice two days after CCl(4) administration. Chemokine CXCL1/keratinocyte-derived chemokine (KC) and MMP-8 were significantly higher in iNKT cell-deficient mice than in control mice. The more severe liver injury in Jα18(-/-) mice was associated with greater leukocyte infiltrate, which was enriched in neutrophils (CD11b(+) CD11c(-) Gr-1(+) cells), in agreement with CXCL1/KC and MMP-8 levels. Complementary experiments with NK-depleted animals indicate a minor role for NK cells in the liver damage found in iNKT-deficient mice. Thus, unlike for ConA-induced hepatitis, we report that iNKT cells protect the liver against acute hepatitis induced by CCl(4) and limit neutrophil infiltration.     

原卟啉钠对急性肝损伤小鼠肝组织SOD、MDA的影响

 目的 探讨原卟啉钠对四氯化碳（CCl4）致急性肝损伤小鼠血清转氨酶和肝组织超氧化物歧化酶（SOD）、脂质过氧化产物丙二醛（MDA）的影响。方法 60只ICR小鼠随机分为正常对照组、CCl4模型组、联苯双酯组、原卟啉钠低、中、高剂量组。各治疗组每天灌胃给药及造模16h后,摘眼球取血测定血清中谷丙转氨酶（ALT）和谷草转氨酶（AST）活性,剖腹取肝测定肝脏SOD活力和MDA含量。结果 CCl4模型组小鼠血清ALT和AST活力分别为（1879±1219）、（2210±1585）U/L,与正常对照组比较,降低显著（P<0.01）;联苯双酯组、原卟啉钠低、中、高剂量组的SOD活力和MDA含量分别为（207.61±16.02）、（184.35±13.42）、（190.88±17.77）、（199.38±14.43）U/mgprot和（1.08±0.15）、（1.35±0.26）、（1.07±0.16）、（0.92±0.18）nmol/mgprot,与CCl4模型组比较,差异有统计学意义（P<0.05～P<0.01）。结论 原卟啉钠能有效阻止CCl4致急性肝损伤小鼠肝组织SOD活性降低,脂质过氧化产物MDA含量升高,具有一定的保肝降酶作用。     

Role of fibroblast growth factor type 1 and 2 in carbon tetrachloride-induced hepatic injury and fibrogenesis

Genomic ablation of hepatocyte-specific fibroblast growth factor receptor (FGFR)4 in mice revealed a role of FGF signaling in cholesterol and bile acid metabolism and hepatolobular restoration in response to injury without effect on liver development or hepatocyte proliferation. Although the potential role of all 23 FGF polypeptides in the liver is still unclear, the most widely studied prototypes, FGF1 and FGF2, are present and have been implicated in liver cell growth and function in vitro. To determine whether FGF1 and FGF2 play a role in response to injury and fibrosis, we examined the impact of both acute and chronic exposure to carbon tetrachloride (CCl(4)) in the livers of FGF1- and FGF2-deficient mice. After acute CCl(4) exposure, FGF1(-/-)FGF2(-/-) mice exhibited an accelerated release of serum alanine aminotransferase similar to FGFR4 deficiency, but no effect on overall hepatolobular restoration or bile acid metabolism. FGF1(-/-)FGF2(-/-) mice exhibited a normal increase in alpha-smooth muscle actin and desmin associated with activation and migration of hepatic stellate cells to damage, but a reduced level of hepatic stellate cell-derived matrix collagen alpha1(I) synthesis. Liver fibrosis resulting from chronic CCl(4) exposure was markedly decreased in the livers of FGF1/FGF2-deficient mice. These results suggest an agonist role for FGF1 and FGF2 in specifically insult-induced liver matrix deposition and hepatic fibrogenesis and a potential target for the prevention of hepatic fibrosis.     

Deficient liver regeneration after carbon tetrachloride injury in mice lacking type 1 but not type 2 tumor necrosis factor receptor.

Signaling by tumor necrosis factor type 1 receptor (TNFR-1) is required for the initiation of liver regeneration after partial hepatectomy. Using knockout mice that lack either TNFR-1 or TNFR-2, we determined whether signaling through TNF receptors is important for liver injury and hepatocyte proliferation induced by carbon tetrachloride (CCl4). Lack of TNFR-1 inhibited hepatocyte DNA synthesis after CCl4 injection. At 44 hours after the injection, replication of hepatocytes in TNFR-1 was 50% to 90% lower than in wild-type (WT) animals, depending on the dose injected. In WT animals, hepatocyte replication was essentially completed by 4 days after CCl4 injection, but replication at a low level persisted in TNFR-1 mice for at least 2 weeks. TNFR-1 knockout mice had little detectable NF-kappa B and STAT3 binding during the first 5 hours after CCl4, high plasma TNF, and reduced levels of plasma interleukin (IL)-6 and liver IL-6 mRNA. Injection of IL-6 30 minutes before CCl4 administration corrected the deficiency of hepatocyte replication at 44 hours and restored STAT3 binding to normal levels. In contrast, mice lacking TNFR-2 did not differ significantly from WT mice in NF-kappa B and STAT3 binding, IL-6 and TNF levels, or hepatocyte replication. Although AP-1 binding was induced in WT TNFR-1 and TNFR-2 knockout mice, binding in TNFR-2 knockouts was lower than in WT mice. C/EBP binding was much lower in TNFR-1 and TNFR-2 knockout mice than in WT mice. As assessed by morphological analysis and alanine aminotransferase levels, the acute injury caused by CCl4 appeared to be similar in the three groups of animals, but subsequent regeneration was impaired in mice lacking TNFR-1. We conclude that a TNFR-1 signaling pathway involving NF-kappa B, IL-6, and STAT3 is an important component of the hepatocyte mitogenic response induced by CCl4 injury in mouse liver.     

High-mobility group box 1 exacerbates CCl4-induced acute liver injury in mice

High-mobility group box 1 (HMGB1) is a nuclear factor that can also serve as an imflammatory mediator once released into extracellular milieu. Therefore, HMGB1 has been recognized to play a pivotal role in inflammatory diseases such as sepsis, acute lung injury, ischemia reperfusion injury and type 1 diabetes. Nevertheless, its impact on carbon tetrachloride (CCl₄)-induced hepatic injury is yet to be elucidated. In the present report, we demonstrated evidence indicating that high levels of HMGB1 were not only present in the necrotic area of liver but also in the serum after CCl₄ challenge. In line with these observations, administration of exogenous recombinant HMGB1 exacerbated CCl₄-induced hepatic injury, while HMGB1 blocking antibody provided protection for mice against CCl₄-induced acute liver injury as evidenced by the decrease of serum transaminase and reduction of hepatic tissues necrosis. Mechanistic studies revealed that blockade of HMGB1 attenuated CCl₄-induced MDA accumulation along with improved SOD and GSH activity. Treatment of mice with HMGB1 neutralizing antibody also significantly inhibited the production of proinflammatory mediators TNF-α and IL-6 along with attenuated HMGB1 expression and its extracellular release. Together, our data suggest an essential role for HMGB1 in CCl₄-induced acute liver injury, while HMGB1 neutralizing antibody could be served as an effective regimen for preventing CCl₄-induced acute liver injury.     

四氯化碳致小鼠急性肝损伤的性别差异及其与雄激素受体表达的关系

目的比较CCl4对不同性别小鼠急性肝损伤的诱导作用及其对肝脏雄激素受体(AR)表达的影响。方法健康成年昆明小鼠70只,随机分为CCl4雄性组、CCl4雌性组、雄性对照组,雌性对照组。50%CCl4-粟米油溶液皮下注射,0.6ml/100g体重,1周2次,诱导小鼠急性肝损伤。造模第7天处死各组动物取材固定,常规HE染色比较不同组别小鼠肝组织病理变化;免疫组织化学法检测各组小鼠肝脏AR的表达,根据阳性细胞反应强度及百分比设定0级(阴性)及1-3级(阳性)标准,双盲计分法统计各组AR表达分值。结果实验组CCl4造模过程中雄性组小鼠死亡率为60%(15/25),明显高于雌性组(12%,3/25),对照组小鼠无死亡(0/10,0/10)。肝组织HE染色结果可见CCl4诱导的急性肝损伤主要部位为肝小叶周围的门管区及界板区,损伤部位肝细胞出现脂肪变,少数肝组织出现点状坏死。免疫组化显示雄性及雌性对照组小鼠肝细胞AR呈弱阳性表达,不同性别小鼠肝细胞AR表达差别无统计学意义;实验组各组别肝小叶周围受损肝细胞出现较强的AR表达,其中CCl4雄性组AR表达分值明显高于CCl4雌性组小鼠(P<0.01)。结论雄性小鼠对急性肝损伤的耐受性低于雌性小鼠,其中AR的高表达与CCl4诱导的急性肝损伤性别差异密切相关。     

CXCL10 promotes liver fibrosis by prevention of NK cell mediated hepatic stellate cell inactivation

Chemokines, such as CXCL10, promote hepatic inflammation in chronic or acute liver injury through recruitment of leukocytes to the liver parenchyma. The CXCL10 receptor CXCR3, which is expressed on a subset of leukocytes, plays an important part in Th1-dependent inflammatory responses. Here, we investigated the role of CXCL10 in chemically induced liver fibrosis. We used carbon tetrachloride (CCl(4)) to trigger chronic liver damage in wildtype C57BL/6 and CXCL10-deficient mice. Fibrosis severity was assessed by Sirius Red staining and intrahepatic leukocyte subsets were investigated by immunohistochemistry. We have further analyzed hepatic stellate cell (HSC) distribution and activation and investigated the effect of CXCL10 on HSC motility and proliferation. In order to demonstrate a possible therapeutic intervention strategy, we have examined the anti-fibrotic potential of a neutralizing anti-CXCL10 antibody. Upon CCl(4) administration, CXCL10-deficient mice showed massively reduced liver fibrosis, when compared to wildtype mice. CXCL10-deficient mice had less B- and T lymphocyte and dendritic cell infiltrations within the liver and the number and activity of HSCs was reduced. In contrast, natural killer (NK) cells were more abundant in CXCL10-deficient mice and granzyme B expression was increased in areas with high numbers of NK cells. Further detailed analysis revealed that HSCs express CXCR3, respond to CXCL10 and secrete CXCL10 when stimulated with IFNγ. Blockade of CXCL10 with a neutralizing antibody exhibited a significant anti-fibrotic effect. Our data suggest that CXCL10 is a pro-fibrotic factor, which participates in a crosstalk between hepatocytes, HSCs and immune cells. NK cells seem to play an important role in controlling HSC activity and fibrosis. CXCL10 blockade may constitute a possible therapeutic intervention for hepatic fibrosis.