肝细胞色素P450 2E1在实验性肝纤维化组织中的表达

目的 研究肝细胞色素Ｐ４５０ ２Ｅ１在实验性肝纤维化组织中的表达。方法 ８只Ｗｉｓｔａｒ大鼠,建立四氯化碳（ＣＣｌ４）肝纤维化模型,用免疫组织化学方法观察肝纤维化模型肝组织中肝细胞色素Ｐ４５０ ２Ｅ１。结果 正常肝组织内,ＣＹＰ ２Ｅ１表达仅见于中央静脉周围区,主要表达于肝腺泡Ⅲ区,２～３层细胞厚,肝细胞浆和细胞膜可见ＣＹＰ ２Ｅ１表达。在ＣＣｌ４模型肝组织中,ＣＹＰ ２Ｅ１表达的强度增加,分布的     

Effects of iron overload in a rat nutritional model of non-alcoholic fatty liver disease.

BACKGROUND/AIMS: This study sought to determine whether excess hepatic iron potentiates liver injury in the methionine choline-deficient (MCD) model of non-alcoholic fatty liver disease (NAFLD). METHODS: Iron-loaded rats were fed either MCD or control diets [MCD diet plus choline bitartrate (2 g/kg) and DL-methionine (3 g/kg)] for 4 and 12 weeks, after which liver pathology, hepatic iron, triglyceride, lipid peroxidation products and hydroxyproline (HYP) levels and serum alanine aminotransferase (ALT) levels were evaluated. RESULTS: Iron supplementation in MCD animals resulted in histologic evidence of hepatic iron overload at 4 and 12 weeks and a 14-fold increase in hepatic iron concentration at 12 weeks (P < 0.001). Iron supplementation in these animals was associated with increased lobular necroinflammation at 4 weeks (P < 0.02) and decreased hepatic steatosis (P < 0.01), hepatic triglyceride levels (P < 0.01), hepatic-conjugated dienes (CD; P < 0.02) and serum ALT levels (P < 0.002) at 12 weeks. Reduced hepatic steatosis (P < 0.005) and CD (P < 0.01) were apparent by 4 weeks. Iron supplementation was associated with a trend towards increased perivenular fibrosis not hepatic HYP content. CONCLUSION: Hepatic iron overload in the MCD model of NAFLD is associated with decreased hepatic lipid, decreased early lipid peroxidation products, increased necroinflammation and a trend towards increased perivenular fibrosis.     

Fibrosis in chronic hepatitis C correlates significantly with body mass index and steatosis

Steatosis is a frequent histological finding in chronic hepatitis C infection; however, the pathophysiology of steatosis and its role in disease progression have not been established. We studied 148 consecutive patients with untreated chronic hepatitis C to assess the effect of body mass index, diabetes mellitus, alcohol consumption, hepatic iron content, and viral load on steatosis and hepatic fibrosis. Ninety-one patients (61%) had steatosis: grade 1 (<30% hepatocytes involved) in 61 (41%), grade 2 (30%-70% hepatocytes involved) in 17 (11%), and grade 3 (>70% hepatocytes involved) in 13 (9%). After adjusting for potential confounding variables, a highly significant relationship was found primarily between steatosis and body mass index (P <.0001). The mean (+/-SD) body mass index of patients with no steatosis was 23.9 +/- 4.3 kg/m2, whereas for grade 1 steatosis it was 26.5 +/- 5.1 kg/m2, and for grade 2 and 3 steatosis combined the body mass index was 28.4 +/- 4. 9 kg/m2. Hepatic fibrosis was significantly associated with age (P =. 002). After adjusting for potential confounding variables, including age, hepatic fibrosis was also significantly associated with steatosis (P <.03). There was no significant association between hepatic iron content, alcohol intake, gender, and viral load and steatosis or fibrosis. These findings suggest that increasing body mass index has a role in the pathogenesis of steatosis in chronic hepatitis C and that steatosis may contribute to fibrosis. The association between body mass index and steatosis and fibrosis has important prognostic and therapeutic implications in the management of patients with chronic hepatitis C virus.     

非酒精性脂肪肝肝细胞色素P450ⅡE1的表达与氧化抗氧化的关系

目的研究非酒精性脂肪肝肝细胞色素Ｐ４５０ⅡＥ１表达及与氧化抗氧化的关系。方法用免疫组织化学的方法研究高脂饲料诱导的大鼠脂肪肝肝细胞色素Ｐ４５０ⅡＥ１的表达,同时检测肝组织中雨二醛（ＭＤＡ）和超氧化物歧化酶（ＳＯＤ）、谷胱甘肽（ＧＳＨ）、维生素Ｅ（ＶｉｔＥ）含量的变化,并分析其相关性。结果高脂饲料诱导的大鼠脂肪肝肝细胞色素Ｐ４５０ⅡＥ１在腺泡３区的表达增强,并从３区弥散至２区,与正常组相比,脂肪肝肝组织中ＭＤＡ的含量显著升高（Ｐ＜０．０１）．而ＳＯＤ、ＧＳＨ、ＶｉｔＥ的含量显著下降（Ｐ值分别小于０．０１、０．０５、０．０１）。相关分析表明,肝ＣＹＰＨＥＩ的表达与ＭＤＡ呈非常显著的正相关（Ｐ＜０．０１）、而与ＳＯＤ、ＧＳＨ、ＶｉｔＥ呈显著的负相关ｕ值分别小于０．０５、０．０５、０．０１）。结论非酒精性脂肪肝肝细胞色素Ｐ４５０ⅡＥ１在腺泡３区的表达增强,并呈弥散性的分布,与酒精性脂肪肝的表达相似,并可能与脂质过氧化反应有关。     

Genotype-specific mechanisms for hepatic steatosis in chronic hepatitis C infection

BACKGROUND: Hepatic steatosis is common in hepatitis C, but the relative importance of host and viral factors is controversial. In the present prospective study, we examined metabolic factors associated with non-alcoholic fatty liver and viral genotype as predictors of steatosis and fibrosis in chronic hepatitis C infection. METHODS: In 124 chronic hepatitis C patients, the association between liver histology and the following was investigated: demographic and anthropometric data, alcohol intake, alanine aminotransferase (ALT), total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglyceride, transferrin saturation, ferritin, insulin, c-peptide, glucose and insulin resistance (homeostasis model). RESULTS: By multivariate analysis, genotype 3 was associated with increased steatosis grade (P = 0.02). There were significant pairwise interactions between genotype 3 status and total cholesterol (P = 0.01), current alcohol intake (P = 0.04) and serum ALT (P = 0.01). This showed that the etiology of steatosis was different in patients with genotype 3 and those with non-genotype 3 chronic hepatitis C infection. In genotype 3 patients, the degree of steatosis was inversely associated with serum cholesterol (P = 0.005) and positively associated with serum triglyceride (P = 0.02). There was no association between body mass index (BMI) and the extent of steatosis. Among patients with other genotypes, the steatosis grade was strongly influenced by BMI (P < 0.0001) and serum ALT (P < 0.01). Independent predictors of fibrosis were age (P = 0.001), past alcohol intake (P = 0.04), ALT (P = 0.002), serum insulin (P = 0.001) and portal inflammation (P < 0.001). CONCLUSIONS: Hepatitis C genotype 3 may interfere with pathways of hepatic lipid metabolism, whereas increased BMI appears to be a more important pathogenic factor in other genotypes. Although steatosis and BMI were not associated with hepatic fibrosis, their relationship with serum insulin suggests that metabolic factors related to insulin action could influence fibrogenesis in hepatitis C.     

e抗原阴性慢性乙型肝炎合并肝脂肪变的预测指标及炎性反应和纤维化诊断

目的 研究HBeAg阴性慢性乙型肝炎(CHB)合并肝脂肪变患者的临床和病理关系,探讨预测此类患者肝组织炎性反应和纤维化的指标.方法 分别收集经临床与病理检查确诊的HBeAg阴性CHB合并和不合并肝脂肪变患者56例和60例,分别研究并比较其空腹血糖(FBG)、空腹血胰岛素(FINS)、三酰甘油(TG)、胆固醇(TC)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、谷氨酰转肽酶(GGT)、碱性磷酸酶(ALP)、白蛋白(Alb)、球蛋白(Glb)、胰岛素抵抗指数(HOMA-IR)、HBV DNA水平、体重指数(BMI),并就上述指标与肝组织脂肪变、炎性反应和纤维化的关系进行统计学分析.结果 与HBeAg阴性CHB不合并肝脂肪变者相比,合并肝脂肪变患者BMI、FBG、FINS、TG、TC、GGT、ALP、Glb和HOMA-IR明显增高(P值均<0.05),HBV DNA、AST、ALT、Alb明显降低(P值均<0.05),此外炎性反应程度和纤维化程度亦明显增强.可预测HBeAg阴性CHB者是否存在肝脂肪变的参数有BMI,FBG、FINS、TG、TC、GGT和HOMA-IR(P值均<0.05).可预测HBeAg阴性CHB合并肝脂肪变者肝组织是否存在炎性反应的参数有ALT、AST、Glb和HBVDNA(P值均<0.05),可预测其是否存在肝组织纤维化的参数有ALT,AST、Alb、Glb和HBV DNA(P值均<0.05).结论 肝脂肪变在HBeAg阴性CHB患者中较常见,其肝组织脂肪变与BMI、FBG、FINS、TG、TC、GGT和HOMA-IR有关.此类患者除肝脂肪变明显增加外,肝组织炎性反应和纤维化程度亦明显加重.     

Inhibiting triglyceride synthesis improves hepatic steatosis but exacerbates liver damage and fibrosis in obese mice with nonalcoholic steatohepatitis

In the early stages of nonalcoholic fatty liver disease (NAFLD), triglycerides accumulate in hepatocytes. Diacylglycerol acyltransferase 2 (DGAT2) catalyzes the final step in hepatocyte triglyceride biosynthesis. DGAT2 antisense oligonucleotide (ASO) treatment improved hepatic steatosis dramatically in a previous study of obese mice. According to the 2-hit hypothesis for progression of NAFLD, hepatic steatosis is a risk factor for nonalcoholic steatohepatitis (NASH) and fibrosis. To evaluate this hypothesis, we inhibited DGAT2 in a mouse model of NASH induced by a diet deficient in methionine and choline (MCD). Six-week-old genetically obese and diabetic male db/db mice were fed either the control or the MCD diet for 4 or 8 weeks. The MCD diet group was treated with either 25 mg/kg DGAT2 ASO or saline intraperitoneally twice weekly. Hepatic steatosis, injury, fibrosis, markers of lipid peroxidation/oxidant stress, and systemic insulin sensitivity were evaluated. Hepatic steatosis, necroinflammation, and fibrosis were increased in saline-treated MCD diet-fed mice compared to controls. Treating MCD diet-fed mice with DGAT2 ASO for 4 and 8 weeks decreased hepatic steatosis, but increased hepatic free fatty acids, cytochrome P4502E1, markers of lipid peroxidation/oxidant stress, lobular necroinflammation, and fibrosis. Progression of liver damage occurred despite reduced hepatic expression of tumor necrosis factor alpha, increased serum adiponectin, and striking improvement in systemic insulin sensitivity. CONCLUSION: Results from this mouse model would suggest accumulation of triglycerides may be a protective mechanism to prevent progressive liver damage in NAFLD.     

Rodent nutritional model of non-alcoholic steatohepatitis: species, strain and sex difference studies

BACKGROUND AND AIM: The methionine choline-deficient (MCD) diet leads to steatohepatitis in rodents. The aim of the present study was to investigate species, strain and sex differences in this nutritional model of non-alcoholic steatohepatitis (NASH). METHODS: Male and female Wistar, Long-Evans and Sprague-Dawley rats, and C57/BL6 mice (n = 6 per group) were fed a MCD diet for 4 weeks. Control groups received an identical diet supplemented with choline bitartrate (0.2% w/w) and methionine (0.3% w/w). Liver pathology (steatosis and inflammation) and ultrastructure, liver lipid profile (total lipids, triglycerides, lipid peroxidation products), liver : body mass ratios and serum alanine aminotransferase (ALT) levels were compared between these groups. RESULTS: The MCD diet-fed male rats developed greater steatosis (P < 0.001), had higher liver lipid content (P < 0.05) and had higher serum ALT levels (P < 0.005) than did female rats. Wistar rats (both sexes) had higher liver lipid levels (P < 0.05), serum ALT levels (P < 0.05), and liver mass : body mass ratios (P < 0.025) than did Long-Evans and Sprague-Dawley rats. In female groups, Wistar rats showed greater fatty change than did the other two strains (P < 0.05). All rats fed the MCD diet developed hepatic steatosis, but necrosis and inflammation were minor features and fibrosis was absent. Compared with Wistar rats, male C57/BL6 mice showed a marked increase in inflammatory foci (P < 0.001), end products of lipid peroxidation (free thiobarbituric acid reactive substances) (P < 0.005), and mitochondrial injury, while showing less steatosis (P < 0.005), lower hepatic triglyceride levels, (P < 0.005) and lower early lipid peroxidation products (conjugated dienes and lipid hydroperoxides; P < 0.005 and P < 0.01, respectively). CONCLUSIONS: The Wistar strain and the male sex are associated with the greatest degree of steatosis in rats subjected to the MCD diet. Of the groups studied, male C57/BL6 mice develop the most inflammation and necrosis, lipid peroxidation, and ultrastructural injury, and best approximate the histological features of NASH.     

Influence of iron on the severity of hepatic fibrosis in patients with chronic hepatitis C

AIM: To evaluate the association among hepatic fibrosis, serum iron indices, and hepatic iron stores in patients with Chronic Hepatitis C (CMC). METHODS: Thirty-two CHC patients were included in our study. The histological degree of fibrosis and inflammation activity was assessed according to the Metavir system. The serum iron indices including ferritin, iron and transferrin saturation were measured. Hepatic iron deposition was graded by Perls' stain. RESULTS: The CHC patients with severe hepatic fibrosis (n = 16) were significantly older than CHC patients with mild fibrosis (n = 16) (P = 0.024). The serum iron indices, increased serum iron store and positive hepatic iron stain were not significantly different between the two groups. In multivariate logistic regression analysis, the age at biopsy was an independent predictor of severe hepatic fibrosis (Odds ratio = 1.312; P = 0.035). The positive hepatic iron stain was significantly associated with the values of alanine aminotransferase (ALT) (P = 0.017), ferritin (P = 0.008), serum iron (P - 0.019) and transferrin saturation (P = 0.003). The ferritin level showed significant correlation with the value of ALT (r = 0.531; P = 0.003), iron (r = 0.467; P = 0.011) and transferrin saturation (r = 0.556; P = 0.002). CONCLUSION: Our findings suggest that the severity of hepatitis C virus (HCV)-related liver injury is associated with patient age at biopsy. Both serum iron indices and hepatic iron deposition show correlation with serum indices of chronic liver disease but are not related to grade and stage of liver histology.     

Influence of iron on the severity of hepatic fibrosis in patients with chronic hepatitis C

AIM: To evaluate the association among hepatic fibrosis, serum iron indices, and hepatic iron stores in patients with Chronic Hepatitis C (CHC). METHODS: Thirty-two CHC patients were included in our study. The histological degree of fibrosis and inflammation activity was assessed according to the Metavir system. The serum iron indices including ferritin, iron and transferrin saturation were measured. Hepatic iron deposition was graded by Peris' stain. RESULTS: The CHC patients with severe hepatic fibrosis (n = 16) were significantly older than CHC patientswith mild fibrosis (n = 16) (P = 0.024). The serum iron indices, increased serum iron store and positive hepatic iron stain were not significantly different between the two groups. In multivariate logistic regression analysis, the age at biopsy was an independent predictor of severe hepatic fibrosis (Odds ratio = 1.312; P = 0.035). The positive hepatic iron stain was significantly associated with the values of alanine aminotransferase (ALT) (P = 0.017), ferritin (P = 0.008), serum iron (P= 0.019) and transferrin saturation (P = 0.003). The ferritin level showed significant correlation with the value of ALT (r = 0.531; P = 0.003), iron (r = 0.467; P = 0.011) and transferrin saturation (r = 0.556; P = 0.002). CONCLUSION: Our findings suggest that the severity of hepatitis C virus (HCV)-related liver injury is associated with patient age at biopsy. Both serum iron indices and hepatic iron deposition show correlation with serum indices of chronic liver disease but are not related to grade and stage of liver histology.     

Steatosis and chronic hepatitis C: analysis of fibrosis and stellate cell activation

BACKGROUND/AIMS: Steatosis is a frequent histological finding in chronic hepatitis C and is associated with increased hepatic fibrosis. METHODS: We studied 80 patients with untreated chronic hepatitis C to determine whether steatosis contributes to fibrosis through a steatohepatitis-like pathway. RESULTS: Fine sinusoidal and/or central vein fibrosis was present in 52 patients (65%). This was typically located in acinar zone 3 and had a chicken-wire appearance similar to that seen in steatohepatitis. A statistically significant relationship was found between subsinusoidal fibrosis and age (r(s) = 0.33, P = 0.003) and grade of steatosis (r(s) = 0.35, P = 0.001). Mean body mass index was higher in patients with focal (28.4 +/- 4.7 kg/m2) or extensive (29.6 +/- 5.9 kg/m2) subsinusoidal fibrosis than in those patients with no subsinusoidal fibrosis (25.5 +/- 3.7 kg/m2). The extent of alpha-smooth muscle actin staining (as a marker of stellate cell activation) correlated with the degree of portal inflammation and the stage of portal fibrosis, but not with the grade of hepatic steatosis. CONCLUSIONS: These findings suggest that in hepatitis C infection, host factors, particularly adiposity, contribute to both steatosis and acinar fibrosis. The implication of these observations is that weight reduction may provide an important therapeutic strategy for patients with chronic hepatitis C.     

e抗原阴性慢性乙型肝炎合并肝脂肪变的预测指标及炎性反应和纤维化诊断

目的 研究HBeAg阴性慢性乙型肝炎(CHB)合并肝脂肪变患者的临床和病理关系,探讨预测此类患者肝组织炎性反应和纤维化的指标.方法 分别收集经临床与病理检查确诊的HBeAg阴性CHB合并和不合并肝脂肪变患者56例和60例,分别研究并比较其空腹血糖(FBG)、空腹血胰岛素(FINS)、三酰甘油(TG)、胆固醇(TC)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、谷氨酰转肽酶(GGT)、碱性磷酸酶(ALP)、白蛋白(Alb)、球蛋白(Glb)、胰岛素抵抗指数(HOMA-IR)、HBV DNA水平、体重指数(BMI),并就上述指标与肝组织脂肪变、炎性反应和纤维化的关系进行统计学分析.结果 与HBeAg阴性CHB不合并肝脂肪变者相比,合并肝脂肪变患者BMI、FBG、FINS、TG、TC、GGT、ALP、Glb和HOMA-IR明显增高(P值均<0.05),HBV DNA、AST、ALT、Alb明显降低(P值均<0.05),此外炎性反应程度和纤维化程度亦明显增强.可预测HBeAg阴性CHB者是否存在肝脂肪变的参数有BMI,FBG、FINS、TG、TC、GGT和HOMA-IR(P值均<0.05).可预测HBeAg阴性CHB合并肝脂肪变者肝组织是否存在炎性反应的参数有ALT、AST、Glb和HBVDNA(P值均<0.05),可预测其是否存在肝组织纤维化的参数有ALT,AST、Alb、Glb和HBV DNA(P值均<0.05).结论 肝脂肪变在HBeAg阴性CHB患者中较常见,其肝组织脂肪变与BMI、FBG、FINS、TG、TC、GGT和HOMA-IR有关.此类患者除肝脂肪变明显增加外,肝组织炎性反应和纤维化程度亦明显加重.     

Correlation of hepatic steatosis with body mass index, serum ferritin level and hepatic fibrosis in Japanese patients with chronic hepatitis C

Aims:  The present study was aimed at determining the predictors of hepatic steatosis and fibrosis in Japanese patients with chronic hepatitis C.
Methods:  The relationship between the degrees of hepatic steatosis or fibrosis and several clinical parameters was evaluated using univariate and multivariate analyses.
Results:  Steatosis was observed in 117 out of 184 patients (64%), including 45 patients (25%) with grade 1 (<10% of hepatocytes affected), 56 patients (30%) with grade 2 (10–30%), 12 patients (7%) with grade 3 (30–50%), and four patients (2%) with grade 4 (>50%). In the multivariate analysis, body mass index (BMI) ( P  =   0.0038) and serum ferritin ( P  <   0.0001) were selected as independent predictors of hepatic steatosis. Six of the 184 patients (3%) had stage 0 fibrosis (no fibrosis), 87 patients (47%) had stage 1, 55 patients (30%) had stage 2 and 36 patients (20%) had stage 3. In the multivariate analysis, platelet count ( P  =   0.0012), aspartate aminotransferase (AST) ( P  =   0.0219), hyaluronic acid ( P  <   0.0001) and the grade of steatosis ( P  =   0.0008) were selected as independent predictors of hepatic fibrosis.
Conclusion:  Obesity and iron storage, as evaluated by BMI and serum ferritin level, respectively, have important roles in the pathogenesis of hepatic steatosis, which is a factor responsible for the development of hepatic fibrosis in Japanese patients with chronic hepatitis C.     

Clinical cofactors and hepatic fibrosis in hereditary hemochromatosis: The role of diabetes mellitus

The risk of hepatic fibrosis and cirrhosis in hereditary hemochromatosis relates to the degree of iron loading, but iron alone does not explain the variability in disease penetrance. This study sought to identify clinical cofactors that increase the risk of progressive liver disease. We identified 291 patients from our database who were homozygous for the C282Y mutation in HFE and had undergone a liver biopsy with quantification of hepatic iron concentration (HIC) and fibrosis staging. Data were collected from a retrospective chart review, including age, gender, alcohol consumption, medical therapy, smoking history, metabolic risk factors, mobilizable iron, and laboratory results. Male gender, excess alcohol consumption, HIC, and the presence of diabetes were independently associated with increasing fibrosis stage in multivariate analysis. Of these, the presence of diabetes showed the strongest association (odds ratio, 7.32; P = 0.03). The presence of steatosis was associated with higher fibrosis scores, but this was of borderline statistical significance. Risk factors for hepatic steatosis were male gender, impaired glucose tolerance, and increased body mass index. Conclusion: The presence of diabetes was associated with more severe hepatic fibrosis independent of iron loading, male gender, and alcohol consumption. The mechanism for this association is unknown and deserves further evaluation; however, it is possible that diabetes produces an additional hepatic oxidative injury from hyperglycemia. Thus, management of such cofactors in patients with hemochromatosis is important to reduce the risk of liver injury and fibrosis. (Hepatology 2012;56:904-911).     

The pathogenesis of nonalcoholic steatohepatitis and other fatty liver diseases: a four-step model including the role of lipid release and hepatic venular obstruction in the progression to cirrhosis

Fatty liver disease involves the accumulation of triglycerides in hepatocytes, necrosis of hepatocytes, inflammation, and often fibrosis with progression to cirrhosis. The two-hit model summarizes the important early metabolic events leading to hepatocellular necrosis in nonalcoholic steatohepatitis (NASH). In this article, we provide evidence of lipid release from hepatocytes in posttransplant fat necrosis and in NASH and quantify vascular obliteration in a series of biopsies with NASH. Obliteration of small hepatic veins (<30 microm) in small numbers is compensated by collateral flow. Obliteration of larger hepatic veins (>30 microm) is associated with fibrotic collapse lesions that are not easily resorbed. Based on these observations, we propose a new four-step model that includes the later events that lead to cirrhosis after necrosis has occurred. This model is applicable to nonalcoholic fatty liver disease (NAFLD), alcoholic disease, postjejunoileal bypass disease, and posttransplant fat necrosis. The first step is steatosis facilitated by insulin, and the second is necrosis induced by intracellular lipid toxicity or lipid peroxidation, or both, modified by alcohol, drugs, and ischemia. The third step is release of bulk lipid from hepatocytes into the interstitium leading to direct and inflammatory injury to hepatic veins. The fourth step is venous obstruction with secondary collapse and ultimately fibrous septation and cirrhosis.     

Combination of oxidative stress and steatosis is a risk factor for fibrosis in alcohol-drinking patients with chronic hepatitis C

BACKGROUND AND AIMS: Alcohol and HCV have been shown to interact in stimulating hepatic oxidative damage. Thus, we investigated the contribution of oxidative mechanisms in the progression of chronic hepatitis C (CHC) in alcohol consumers. METHODS: An increased IgG reactivity against lipid peroxidation-derived antigens was used as the marker for alcohol-induced oxidative damage in 125 CHC patients. RESULTS: Alcohol intake significantly increased the frequency of the subjects with elevated lipid peroxidation-related IgG. However, no association was evident between oxidative stress markers and the severity of steatosis, necroinflammation, or fibrosis. Multivariate analysis revealed that age (P= 0.014) and hepatic iron content (P= 0.034) were the only independent predictors of fibrosis in these patients. However, the risk of fibrosis in the subjects with both steatosis and oxidative stress-induced immune responses was 6- (OR 6.2, 95% CI 1.2-31.0) and 14-fold (OR 14.6, 95% CI 3.1-68.1) higher than in the subjects with steatosis alone or without steatosis, respectively. Multivariate analysis confirmed that the combination of steatosis and oxidative stress (P= 0.045) was, together with age (P= 0.021) and hepatic iron content (P= 0.027), an independent risk factor for fibrosis in CHC patients with alcohol intake. CONCLUSIONS: These results demonstrate that oxidative stress interacts with steatosis to promote the progression of CHC in alcohol-consuming patients.     

Hepatic stellate cell activation occurs in nonalcoholic steatohepatitis

BACKGROUND/AIMS: Hepatic stellate cell activation has a major role in the pathogenesis of hepatic fibrosis, considered to constitute part of the healing response to a necroinflammatory stimulus. However, steatosis per se, has also been shown to induce this activation. This study evaluates if hepatic stellate cell activation is present, and how it correlates with steatosis, in nonalcoholic steatohepatitis, whose hallmark is steatosis. METHODOLOGY: Steatosis, hepatocyte damage, inflammation and fibrosis were graded from 0 to 3+, in liver biopsies from 15 well documented nonalcoholic steatohepatitis and 5 normal controls. Activated hepatic stellate cell activation were identified immunohistochemically using a monoclonal antibody raised against cytoplasmic alpha-smooth muscle actin, and semiquantitatively graded using a scoring method. RESULTS: Nonalcoholic steatohepatitis patients showed significantly greater numbers of alpha-smooth muscle actin-reactive hepatic stellate cell than controls: hepatic stellate cell index of 3.6 +/- 1.9 versus 1.5 +/- 0.5, P < 0.05. The distribution of alpha-smooth muscle actin-reactive hepatic stellate cell was higher in the perivenular areas, than in the intermediate zone and portal area, with no significant association between steatosis and alpha-smooth muscle actin-expressing hepatic stellate cell. However, a significant association was found between portal and lobular inflammation and hepatic stellate cell index, r = 0.72, P = 0.0005 and r = 0.75, P = 0.0002, respectively. CONCLUSIONS: This study demonstrates that hepatic stellate cell activation occurs in nonalcoholic steatohepatitis, clearly correlating with portal and lobular inflammation, but not with steatosis, suggesting that the mechanisms implicated in fibrosis in nonalcoholic steatohepatitis are probably related with inflammation.     

Experimental evidence of obstructive sleep apnea syndrome as a second hit accomplice in nonalcoholic steatohepatitis pathogenesis

Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (CIH) during sleep. OSA is associated with nonalcoholic steatohepatitis (NASH) in obese individuals and may contribute to progression of nonalcoholic fatty liver disease from steatosis to NASH. The purpose of this study was to examine whether CIH induces inflammatory changes in the liver in mice with diet-induced hepatic steatosis. C57BL/6J mice (n = 8) on a high-fat, high-cholesterol diet were exposed to CIH for 6 mo and were compared with mice on the same diet exposed to intermittent air (control; n = 8). CIH caused liver injury with an increase in serum ALT (461 ± 58 U/l vs. 103 ± 16 U/l in the control group; p < 0.01) and AST (637 ± 37 U/l vs. 175 ± 13 U/l in the control group; p < 0.001), whereas alkaline phosphatase and total bilirubin levels were unchanged. Histology revealed hepatic steatosis in both groups, with mild accentuation of fat staining in the zone 3 hepatocytes in mice exposed to CIH. Animals exposed to CIH exhibited lobular inflammation and fibrosis in the liver, which were not evident in control mice. CIH caused significant increases in lipid peroxidation in serum and liver tissue; significant increases in hepatic levels of myeloperoxidase and proinflammatory cytokines IL-1P, IL-6, and CXC chemokine MIP-2; a trend toward an increase in TNF-α; and an increase in α1(I)-collagen mRNA. We conclude that CIH induces lipid peroxidation and inflammation in the livers of mice on a high-fat, high-cholesterol diet.Abstract published under the permission of the editor of Am J Physiol Gastrointest Liver Physiol     

Association between Alcoholism and Increased Hepatic Iron Stores

Although alcoholic liver disease is often associated with some increase in hepatic iron stores, it is now established that when gross iron overload is present, this is due to genetic hemochromatosis. Furthermore, there appears to be a critical iron concentration necessary for the induction of hepatic fibrosis. Lipid peroxidation induced by ethanol and/or iron would appear to play a major role in hepatic damage in both humans and experimental animals. Although the exact mechanism(s) of induction of lipid peroxidation by ethanol and iron remains to be elucidated, both toxins can exert a synergistic effect upon hepatic lipid peroxidation. Iron overload has also been shown to stimulate directly hepatocyte and hepatic procollagen mRNA expression, which is further stimulated by ethanol. The observed synergism between iron and alcohol with respect to both hepatic lipid peroxidation and collagen biosynthesis offers a possible explanation of the apparent early onset of fibrosis and cirrhosis in patients with iron overload who have an excessive alcohol intake.