Umbilical cord-derived mesenchymal stem cells alleviate liver fibrosis in rats

AIM: To evaluate the efficacy of umbilical cord-derived mesenchymal stem cells(UC-MSCs) transplantation in the treatment of liver fibrosis.METHODS: Cultured human UC-MSCs were isolated and transfused into rats with liver fibrosis induced by dimethylnitrosamine(DMN). The effects of UC-MSCs transfusion on liver fibrosis were then evaluated by histopathology; serum interleukin(IL)-4 and IL-10 levels were also measured. Furthermore, Kupffer cells(KCs) in fibrotic livers were isolated and cultured to analyze their phenotype. Moreover, UC-MSCs were cocultured with KCs in vitro to assess the effects of UCMSCs on KCs' phenotype, and IL-4 and IL-10 levels were measured in cell culture supernatants. Finally, UCMSCs and KCs were cultured in the presence of IL-4 antibodies to block the effects of this cytokine, followed by phenotypical analysis of KCs.RESULTS: UC-MSCs transfused into rats were recruited by the injured liver and alleviated liver fibrosis, increasing serum IL-4 and IL-10 levels. Interestingly, UC-MSCs promoted mobilization of KCs not only in fibrotic livers, but also in vitro. Co-culture of UC-MSCs with KCs resulted in increased production of IL-4 and IL-10. The addition of IL-4 antibodies into the coculture system resulted in decreased KC mobilization.CONCLUSION: UC-MSCs could increase IL-4 and promote mobilization of KCs both in vitro and in vivo, subsequently alleviating the liver fibrosis induced by DMN.     

HMGB1在急性肝衰竭大鼠中的表达及作用

目的探讨HMGB1在急性肝衰竭大鼠肝组织和血中的变化规律及作用。方法将48只健康雌性SD大鼠按数字表随机分为对照组、模型组,每组24只,采用腹腔内注射D-Gal N（400 mg/kg）＋LPS（100μg/kg）的方法诱导急性肝衰竭,同时对照组予腹腔注射等量生理盐水。两组大鼠均在4、8、12小时时间点取血液及肝组织标本,检测血清ALT、AST水平,HE染色观察肝组织病理变化,ELISA法检测血清HMGB1浓度,RT-PCR法检测肝组织HMGB1 m RNA表达,免疫组化法检测肝组织HMGB1的表达。结果 D-Gal N（400 mg/kg）＋LPS（100μg/kg）的方法能成功诱导急性肝衰竭模型。对照组血清HMGB1浓度及肝组织HMGB1 m RNA表达在各时间点均较低,而模型组随时间延长而升高。对照组肝细胞核与胞浆中仅见少量HMGB1蛋白表达,模型组肝组织HMGB1蛋白表达随时间延长升高。结论急性肝衰竭时血和肝组织中HMGB1水平均随时间延长而升高,且两者变化与肝损程度正相关。     

Role of cathepsin B-mediated apoptosis in fulminant hepatic failure in mice

AIM: To investigate the pathogenic role of cathepsin B and the protective effect of a cathepsin B inhibitor (CA-074Me) in fulminant hepatic failure in mice.METHODS: LPS/D-Gal N was injected into mice of the model group to induce fulminant hepatic failure;the protected group was administered CA-074me for 30 min before LPS/D-Gal N treatment; the normal group was given isochoric physiologic saline. Liver tissue histopathology was determined with HE at 2,4, 6 and 8 h after Lps/D-Gal injection. Hepatocyte apoptosis was examined by TUNEL method. The expression of cathepsin B in liver tissues was investigated by immunohistochemistry, Western blot and RT-PCR.RESULTS: Compared with the normal group, massive typical hepatocyte apoptosis occurred in the model group; the number of apoptotic cells reached a maximum 6 h after injection. The apoptosis index (AI) in the protected group was clearly reduced (30.4$$$$markedly increased in drug-treated mice compared with the normal group ( P < 0.01). Incubation with LPS/D-Gal N at selected time points resulted in a timedependent increase in cathepsin B activity, and reached a maximum by 8 h. The expression of cathepsin B was significantly decreased in the protected group ( P <0.01).CONCLUSION: Cathepsin B plays an essential role in the pathogenesis of fulminant hepatic failure, and the cathepsin B inhibitor CA-074me can attenuate apoptosis and liver injury.     

The nicotinamide adenine dinucleotide phosphate oxidase (NOX) homologues NOX1 and NOX2/gp91(phox) mediate hepatic fibrosis in mice

Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a multicomponent enzyme that mediates electron transfer from nicotinamide adenine dinucleotide phosphate to molecular oxygen, which leads to the production of superoxide. NOX2/gp91(phox) is a catalytic subunit of NOX expressed in phagocytic cells. Several homologues of NOX2, including NOX1, have been identified in nonphagocytic cells. We investigated the contributory role of NOX1 and NOX2 in hepatic fibrosis. Hepatic fibrosis was induced in wild-type (WT) mice, NOX1 knockout (NOX1KO) mice, and NOX2 knockout (NOX2KO) mice by way of either carbon tetrachloride (CCl(4) ) injection or bile duct ligation (BDL). The functional contribution of NOX1 and NOX2 in endogenous liver cells, including hepatic stellate cells (HSCs), and bone marrow (BM)-derived cells, including Kupffer cells (KCs), to hepatic reactive oxygen species (ROS) generation and hepatic fibrosis was assessed in vitro and in vivo using NOX1 or NOX2 BM chimeric mice. Hepatic NOX1 and NOX2 messenger RNA expression was increased in the two experimental mouse models of hepatic fibrosis. Whereas NOX1 was expressed in HSCs but not in KCs, NOX2 was expressed in both HSCs and KCs. Hepatic fibrosis and ROS generation were attenuated in both NOX1KO and NOX2KO mice after CCl(4) or BDL. Liver fibrosis in chimeric mice indicated that NOX1 mediates the profibrogenic effects in endogenous liver cells, whereas NOX2 mediates the profibrogenic effects in both endogenous liver cells and BM-derived cells. Multiple NOX1 and NOX2 components were up-regulated in activated HSCs. Both NOX1- and NOX2-deficient HSCs had decreased ROS generation and failed to up-regulate collagen α1(I) and transforming growth factor β in response to angiotensin II. CONCLUSION: Both NOX1 and NOX2 have an important role in hepatic fibrosis in endogenous liver cells, including HSCs, whereas NOX2 has a lesser role in BM-derived cells.     

Suppression of lipopolysaccharide-induced nitric oxide synthase expression by platelet-activating factor receptor antagonists in the rat liver and cultured rat Kupffer cells.

Excessive nitric oxide (NO) generated by hepatic cells in response to lipopolysaccharide (LPS) and inflammatory substances (e.g., platelet-activating factor [PAF]) is a key contributor to the pathophysiological outcomes observed in the liver during sepsis. In rats subjected to liver-focused endotoxemia, inducible nitric oxide synthase (iNOS) levels in the intact liver were elevated by 6 hours; cell-specific expression of iNOS messenger RNA (mRNA) was Kupffer cells (KCs), endothelial cells, and hepatocytes. Elevated serum alanine transaminase (ALT) levels at 6 hours confirmed hepatic damage. Pretreatment of endotoxemic rats with PAF receptor antagonists BN 50739 or WEB 2170 reduced serum ALT and iNOS mRNA levels in the intact liver. Pretreatment of cultured KCs with BN 50739 or WEB 2170 inhibited both LPS and PAF-induced iNOS mRNA formation. In addition, LPS-induced iNOS protein levels in KCs pretreated with BN 50739 or WEB 2170 were decreased. Exposure of KCs to either LPS or PAF caused the translocation of the p65 subunit of nuclear factor kappa B (NF-kappaB) into the nucleus and this process was attenuated by BN 50739 and WEB 2170. There was concomitant inhibition of LPS-dependent degradation of the inhibitory protein IkappaBalpha and increase in intracellular Ca(2+) in KC treated with BN 50739 or WEB 2170. Also, in KCs, LPS was able to induce iNOS mRNA expression independent of CD14. This response was inhibited by pretreatment of KCs with either BN 50739 or WEB 2170. Our findings indicate that PAF receptor antagonists convey protection against hepatocellular injury accompanied by a decrease in nitric oxide (NO) formation in the livers of endotoxemic rats.     

Effect of Losartan, an Angiotensin II Antagonist, on Hepatic Fibrosis Induced by CCl4 in Rats

In addition to regulating blood pressure and body fluid homeostasis, the renin-angiotensin system (RAS) is also involved in hepatic fibrogenesis. We aimed to investigate the effect of losartan, an angiotensin II (Ang II) antagonist, on CCl4-induced hepatic fibrosis in rats. Hepatic fibrosis was induced by a subcutaneous injection with 50% CCl4 in Sprague-Dawley rats. The amount of CCl4 administered was 1 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in plasma and hydroxyproline (Hyp) contents in liver tissue were assayed by spectrophotometry. Hyaluronic acid (HA) and procollagen III (PC III) were assessed by radioimmunoassay. Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) levels in culture supernatants of Kupffer cells (KCs) stimulated with Ang II was determined by ELISA. Liver samples collected after 12 weeks of CCl4 treatment were stained with hematoxylin and eosin, then scored. Losartan (2.5, 5, and 10 mg x kg(-1), ig) and captopril (100 mg x kg(-1), ig) significantly decreased liver and spleen indexes, serum transaminase (AST, ALT) activities, HA and PC III levels, and Hyp contents in liver tissue in rats of hepatic fibrosis. Histopathological scores showed that losartan had an inhibitory effect on the progression of hepatic fibrosis. In in vitro experiments, losartan (1 x 10(-9) - 1 x 10(-5) M) significantly reduced TNF-alpha and TGF-beta1 levels in culture supernatants of KCs, but captopril (1 x 10(-5) M) did not. The results showed that losartan significantly inhibited the progression of hepatic fibrosis induced by CCl4, and the inhibitory effect of losartan on hepatic fibrosis might be associated with its ability to inhibit the production of TNF-alpha and TGF-beta1 by activated KCs.     

Ginsenoside Rb1 Reduces D-GalN/LPS-induced Acute Liver Injury by Regulating TLR4/NF-κB Signaling and NLRP3 Inflammasome

Background and AimsThe effect of ginsenoside Rb1 on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury (ALI) is unknown. The aim of this study was to evaluate the effect of ginsenoside Rb1 on ALI and its underlying mechanisms.MethodsMice were pretreated with ginsenoside Rb1 by intraperitoneal injection for 3 days before D-GalN/LPS treatment, to induce ALI. The survival rate was monitored every hour for 24 h, and serum biochemical parameters, hepatic index and histopathological analysis were evaluated to measure the degree of liver injury. ELISA was used to detect oxidative stress and inflammatory cytokines in hepatic tissue and serum. Immunohistochemistry staining, RT-PCR and western blotting were performed to evaluate the expression of toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB), and NLR family, pyrin domain-containing 3 protein (NLRP3) in liver tissue and Kupffer cells (KCs).ResultsGinsenoside Rb1 improved survival with D-GalN/LPS-induced ALI by up to 80%, significantly ameliorated the increased alanine and aspartate transaminase, restored the hepatic pathological changes and reduced the levels of oxidative stress and inflammatory cytokines altered by D-GalN/LPS. Compared to the control group, the KCs were increased in the D-GalN/LPS groups but did not increase significantly with Rb1 pretreatment. D-GalN/LPS could upregulate while Rb1 pretreatment could downregulate the expression of interleukin (IL)-1β, IL-18, NLRP3, apoptosis associated speck-like protein containing CARD (ASC) and caspase-1 in isolated KCs. Furthermore, ginsenoside Rb1 inhibited activation of the TLR4/NF-κB signaling pathway and NLRP3 inflammasome induced by D-GalN/LPS administration.ConclusionsGinsenoside Rb1 protects mice against D-GalN/LPS-induced ALI by attenuating oxidative stress and the inflammatory response through the TLR4/NF-κB signaling pathway and NLRP3 inflammasome activation.     

Oridonin对急性肝衰竭小鼠肝细胞凋亡的影响及其机制研究*

目的 探讨冬凌草甲素（oridonin）对脂多糖/D-氨基半乳糖氨（LPS/D-Gal）联合诱导的急性肝衰竭（ALF） 小鼠肝细胞凋亡的影响,并探讨其可能的机制。方法 取25只小鼠,随机分成5组,每组5只。采用LPS/D-Gal腹腔注射建立小鼠ALF模型,设生理盐水对照组、LPS/D-Gal诱导模型组、LPS/D-Gal诱导和不同剂量oridonin干预组及oridonin处理组。采用末端转移酶介导的缺口末端标记法（TUNEL）检测肝细胞凋亡,采用real-time PCR法检测肝组织TNF-α mRNA水平,采用Western blot法检测凋亡相关蛋白的变化。结果 模型组小鼠肝细胞凋亡率为（36.4±1.8） %,显著高于两个oridonin干预组的[（19.4±3.3）%和（11.4±0.3）%,P<0.01];模型组小鼠肝组织TNF-α mRNA水平显著高于正常对照组（P<0.01）,而两个oridonin干预组肝组织TNF-α mRNA水平显著低于模型组（P<0.01）;模型组小鼠线粒体凋亡通路相关的促凋亡蛋白c-Jun氨基末端激酶（JNK）、bax、细胞色素C、cleaved caspase9/3活化水平显著高于两个oridonin干预组（P<0.01）,模型组小鼠抗凋亡蛋白bcl-xl水平显著低于两个oridonin干预组（P<0.01）,模型组小鼠死亡受体凋亡通路相关的促凋亡蛋白caspase8活化水平与两个oridonin干预组并无明显差异（P>0.01）。结论 Oridonin可抑制LPS/D-Gal诱导的ALF小鼠肝细胞凋亡,其机制可能与下调促凋亡细胞因子TNF-α水平和抑制JNK介导的线粒体凋亡信号通路有关。     

Overexpression of Mcl-1 Attenuates Liver Injury and Fibrosis in the Bile Duct–Ligated Mouse

Hepatocyte apoptosis contributes to liver injury and fibrosis after cholestatic injury. Our aim was to ascertain if the anti-apoptotic protein Mcl-1 alters liver injury or fibrosis in the bile duct–ligated mouse. Markers of apoptosis and fibrosis were compared in wild-type and transgenic mice expressing human Mcl-1 after bile duct ligation. Compared to hMcl-1 transgenic animals, ligated wild-type mice displayed a significant increase in TUNEL-positive cells and in caspase 3/7-positive hepatocytes. Consistent with apoptotic injury, the pro-apoptotic protein Bak underwent a conformational change to an activated form upon cholestatic injury, a change mitigated by hMcl-1 overexpression. Likewise, liver histology, number of bile infarcts, serum ALT values, markers of hepatic fibrosis, and animal survival were improved in bile duct–ligated mice transgenic for hMcl-1 as compared to wild-type mice. In conclusion, increased Mcl-1 expression plays a role in hepatoprotection upon cholestatic liver injury.     

Hydrodynamic-based in vivo transfection of retinoic X receptor-alpha gene can enhance vitamin A-induced attenuation of liver fibrosis in mice.

BACKGROUND/AIM: In hepatic stellate cells isolated from rat fibrotic livers, the amount of retinoid X receptor-alpha (RXR-alpha) mRNA is greatly reduced. However, the effectiveness of retinoids in the treatment of liver fibrosis is controversial. We hypothesized that increasing the expression levels of RXR-alpha in livers will improve the response of liver fibrosis to retinoids treatment. METHODS: pTracer-CMV2 vector harboring both green fluorescent protein and RXR-alpha genes was given to mice with carbon tetrachloride (CCl(4))-induced liver fibrosis, by hydrodynamic-based in vivo transfection. Vitamin A was simultaneously administered to the mice. Sirius red staining and measurement of hydroxyproline content were performed to evaluate liver fibrosis. The incorporation of 5-bromo-2-deoxyribouridine (BrdU) was carried out to determine liver cell proliferation. RESULTS: Successful transfection and expression of exogenous RXR-alpha gene in the liver was determined by observance of green fluorescence under a confocal microscope, and detection of RXR-alpha protein by immunohistochemistry. Hepatic fibrosis, evaluated by both Sirius red staining with image analysis and quantity of hydroxyproline in livers of RXR-alpha-transfected group, tapered off remarkably. The hydroxyproline content and Sirius red-positive staining area on liver sections from RXR-alpha-transfected mice decreased by 34.3% and 54.63%, respectively, compared with the control group receiving empty vector. The labeling index of BrdU in non-parenchymal cells was much lower in livers from the RXR-alpha-transfected group than that of empty vector-transfected group. CONCLUSIONS: Hydrodynamic-based in vivo transfection of the RXR-alpha gene can enhance the vitamin A-induced attenuation of liver fibrosis in mice. One of the possible mechanisms of action for this gene treatment is inhibition of non-parenchymal cell proliferation mainly composed of hepatic stellate cells in fibrotic livers.     

Kupffer cells from CCl4-induced fibrotic livers stimulate proliferation of fat-storing cells

The interaction between fat-storing cells (FSCs) and Kupffer cells (KCs) in vitro has been studied in an attempt to clarify certain aspects of the pathogenesis of fibrotic process in the liver. FSCs and KCs were isolated from the livers of rats either treated with CCl4 for 6 weeks, or with vitamin A for 6 weeks or from untreated rats by the pronase-collagenase digestion method. FSCs were further purified by centrifugation over a double layered metrizamide gradient, and KCs were separated from other sinusoidal cells by the dish adherence technique. FSCs from CCl4-treated rats divided rapidly, while those from vitamin A-treated rats divided slowly, as compared with untreated rats. Furthermore, the proliferation of FSCs was enhanced in the presence of KCs from CCl4-treated rats, but was slightly suppressed by KCs from normal and vitamin A-treated rats. This enhancement was mediated by a non-dialyzable, soluble factor present in the conditioned medium of KCs from CCl4-treated rats, but was not detected in the conditioned medium of KCs from normal or vitamin A-treated rats. From the present study, a growth factor secreted by KCs from CCl4-treated rats may play an important role in controlling the proliferation of FSCs during the pathogenesis of liver fibrosis.     

Significance of septal fibrosis for disturbance of hepatic circulation.

To examine the significance of fibrous septa of the liver for hepatic circulatory disturbance, haemodynamic changes were investigated in rats with septal fibrosis induced with horse serum injections. The fibrotic liver showed thin fibrous bands originating in the vicinity of the peripheral branches of the hepatic vein connected with each other and partly with the portal triads, without conspicuous periportal, pericentral or perisinusoidal fibrosis. There was no evidence of hepatic cell enlargement, disarrangement of hepatic cell plates or narrowing of the sinusoids in the fibrotic livers. Portal vascular resistance, bile production and hepatic oxygen consumption, which were measured by an isolated liver perfusion method, were much the same in the normal and the fibrotic livers. Moreover, there was no significant difference in in vivo blood pressures of the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava between the normal and the fibrotic rats. These data suggest that septal fibrosis in itself does not disturb hepatic circulation.     

Inhibition of sphingosine kinase 1 ameliorates acute liver failure by reducing high-mobility group box 1 cytoplasmic translocation in liver cells

AIM: To determine the therapeutic potential of sphingosine kinase 1(Sphk1) inhibition and its underlying mechanism in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced acute liver failure(ALF).METHODS: Balb/c mice were randomly assigned to different groups,with ALF induced by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). The Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multi-parametric analyzer. Serum high-mobility group box 1(HMGB1),tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,IL-6,IL-10,and sphingosine-1-phosphate were detected by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after acute liver injury induction were assessed by hematoxylin and eosin staining. HMGB1 expression in hepatocytes and cytoplasmic translocation were detected by immunohistochemistry. Expression of Sphk1 in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression of Sphk1 in liver tissue and PBMCs was upregulated in Gal N/LPS-induced ALF. Upregulated Sphk1 expression in liver tissue was mainly caused by Kupffer cells,the resident macrophages of the liver. The survival rates of mice in the N,Ndimethylsphingosine(DMS,a specific inhibitor of Sph K1) treatment group were significantly higher than that of the control group(P 0.001). DMS treatment significantly decreased the levels of serum ALT and AST at 6,12,and 24 h compared with that of the control group(P 0.01 for all). Serum HMGB1 levels at 6,12,and 24 h,as well as serum TNF-α,IL-6,and IL-1β levels at 12 h,were significantly lower in the DMS treatment group than in the control group(P 0.01 for all). Furthermore,hepatic inflammation,necrosis,and HMGB1 cytoplasm translocation in liver cells were significantly decreased in the DMS treatment group compared to the control group(43.72% ± 5.51% vs 3.57% ± 0.83%,χ2 = 12.81,P 0.01).CONCLUSION: Inhibition of Sph K1 ameliorates ALF by reducing HMGB1 cytoplasmic translocation in liver cells,and so might be a potential therapeutic strategy for this disease.     

Orionin对急性肝衰竭小鼠的保护作用及其对肝组织细胞因子水平的影响*

目的 探讨冬凌草甲素（Oridonin）对脂多糖/D-氨基半乳糖氨（LPS/D-Gal）联合诱导的急性肝衰竭（ALF）小鼠的保护作用及其对肝组织细胞因子水平的影响。方法 取150只小鼠,随机分成5组,每组 30 只。采用LPS/D-Gal腹腔注射建立小鼠ALF模型,设生理盐水对照组、Oridonin对照组、LPS/D-Gal诱导模型组和LPS/D-Gal处理及不同剂量Oridonin干预组。采用Real-time PCR法检测肝组织肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1α、IL-1β和IL-6 mRNA水平。结果 模型组小鼠48 h存活率为0.0% （0/30）,而两个Oridonin干预组小鼠48 h存活率分别提高至64.5% （19/30）和80.6% （24/30,P<0.01）; 组织病理学检查显示模型组小鼠肝细胞呈大块或/和亚大块坏死,肝小叶结构消失,残存肝细胞肿胀、空泡变性,肝窦肿胀充血,炎细胞浸润。Oridonin干预组小鼠肝细胞坏死、空泡变性和炎细胞浸润等较模型组有明显的改善;模型组小鼠血清ALT和AST水平分别为（345.3 ± 54.1） U/L和（500.2±53.5） U/L,明显高于对照组的[（42.3±0.6）U/L和（117.1±9.8）U/L,P<0.01],两个Oridonin干预组分别为 （303.9±39.5） U/L和（340.6±2.8） U/L及[（130.2±38.3） U/L和 （209.8±36.2） U/L,P<0.05];模型组小鼠肝组织TNF-α、IL-1α、IL-1β和IL-6 mRNA水平显著高于正常对照组（P<0.01）,而两个Oridonin干预组肝组织TNF-α、IL-1α、IL-1β和IL-6 mRNA水平显著低于模型组 （P<0.01）。结论 Oridonin对LPS/D-Gal诱导的ALF小鼠具有显著的保护作用,其作用机制可能与降低肝组织细胞因子水平有关。     

暴发性肝衰竭中Toll样受体2表达的实验研究

目的 分析D-氨基半乳糖(D-Gal)/脂多糖(LPS)诱导的暴发性肝衰竭模型中肝组织Toll样受体2(TLR2)的表达变化及与细胞因子白细胞介素-18(IL-18)、肿瘤坏死因子α(TNF-α)、γ干扰素(IFN-γ)表达的关系,探讨TLR2在启动炎性应答而致肝损伤中的作用。 方法 BALB/C小鼠腹内联合注射D-Gal 900 mg/kg与LPS 10μg/kg后观察其存活率,并检测不同时间点血清转氨酶和血浆IL-18、TNF-α和IFN-γ含量。用半定量逆转录-聚合酶链反应和Tanon Gis2.0软件分析各时间点肝组织中TLR2 mRNA表达,并与血浆IL-18、TNF-α、IFN-γ含量进行相关分析;免疫组织化学观察肝组织TLR2蛋白的表达。 结果 给药后4 h,血清转氨酶明显升高(与0 h比较,P<0.05);10 h小鼠死亡率达80％。血浆IL-1 8、TNF一α和IFN-γ含量逐步上升,IL-18在1 h即显著升高,之后持续高表达;TNF-α在2 h、5 h有两个分泌高峰;IFN-γ在2 h前增加不明显(F=2.5 7,P=0.1 3),但3 h及以后则显著升高(与0 h比较,P<0.01)。正常小鼠肝组织少量表达TLR2 mRNA,给药后1 h表达即显著增强(与0 h比较,P<0.05);免疫组织化学也显示TLR2蛋白有类似的变化,尤其肝窦内皮细胞、库普弗细胞表达更为显著;且部分肝细胞凋亡、坏死后,残存肝组织仍有较高TLR2表达。相关分析表明,肝组织TLR2 mRNA表达与     

Significance of septal fibrosis for disturbance of hepatic circulation

Abstract: To examine the significance of fibrous septa of the liver for hepatic circulatory disturbance, haemodynamic changes were investigated in rats with septal fibrosis induced with horse serum injections. The fibrotic liver showed thin fibrous bands originating in the vicinity of the peripheral branches of the hepatic vein connected with each other and partly with the portal triads, without conspicuous periportal, pericentral or perisinusoidal fibrosis. There was no evidence of hepatic cell enlargement, disarrangement of hepatic cell plates or narrowing of the sinusoids in the fibrotic livers. Portal vascular resistance, bile production and hepatic oxygen consumption, which were measured by an isolated liver perfusion method, were much the same in the normal and the fibrotic livers. Moreover, there was no significant difference in in vivo blood pressures of the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava between the normal and the fibrotic rats. These data suggest that septal fibrosis in itself does not disturb hepatic circulation.