Hepatic gene expression in patients with obesity-related non-alcoholic steatohepatitis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is among the most common causes of chronic liver disease. NAFLD includes a spectrum of clinicopathologic syndromes that includes non-alcoholic steatohepatitis (NASH) that has potential for progression. The pathogenesis of NASH is poorly characterized. AIM: This study was designed to identify differences in hepatic gene expression in patients with NASH and to relate such differences to their clinical characteristics. DESIGN: Consecutive patients undergoing bariatric surgery were prospectively recruited. Extensive clinical data and two liver biopsy specimens were obtained at the time of enrollment. A single hepatopathologist reviewed and classified the liver biopsies. Patients with excessive alcohol use and other causes of liver disease were excluded. A group of 29 NASH patients, 12 with steatosis alone, seven obese controls and six non-obese controls were selected for further investigation. Customized cDNA microarrays containing 5220 relevant genes were designed specifically for this study. Microarray experiments were run in triplicate for each sample and a selected group of genes were confirmed using real-time PCR. OUTCOME MEASURE: Differential hepatic gene expressions in patients with NASH as compared with controls. Results: Thirty-four genes with significant differential expression were identified in patients with NASH when compared with non-obese controls. Moreover, 19 of these genes showed no significant expression differences in obese vs. non-obese controls, suggesting a stronger association of these genes to NASH. CONCLUSIONS: Several differentially expressed genes in patients with NASH are related to lipid metabolism and extracellular matrix remodeling. Additionally, genes related to liver regeneration, apoptosis, and the detoxification process were differentially expressed. These findings may help clarify the molecular pathogenesis of NASH and identify potential targets for therapeutic intervention.     

Gene expression in obese patients with non-alcoholic steatohepatitis]

Although the molecular basis for the pathophysiology of non-alcoholic steatohepatitis (NASH) is poorly understood, we evaluate the hepatic gene expression of cytokines, chemokines, cell receptors, growth factors, intracellular transducers and extracellular communication proteins in liver tissue of obese patients (with and without NASH), and we determine the specific intrahepatic gene expression profiles associated with histological severe NASH.Thirty-eight obese patients with BMI > 35 were analyzed, who underwent bariatric surgery. Biopsy specimen samples were snap-frozen in liquid nitrogen. Hepatic gene expression was determined in liver biopsy specimens from 3 groups: a) obese patients without NASH (n = 12); b) patients with NASH without fibrosis (n = 13); and c) patients with NASH and fibrosis (n = 13). Genes were considered to be expressed differentially in NASH only if there was a greater than 2-fold difference in abundance of mRNA when compared with each of the control group. These results were confirmed by real-time PCR. Fourteen genes were differentially expressed (10 overexpressed and 4 underexpressed) in patients with NASH. Genes that were significantly overexpressed included prohibitin, TNF, TNF RI (p55), MCSF, R2-TRAIL, b1-CTGF, FGF, VEGF, and BIGH3OBR. Insulin growth factor-1, insulin growth factor-2, interleukin-2 and tyrosine-receptor were underexpressed in NASH patients.In conclusion:1. The obese patients with NASH without fibrosis show an overexpression of proinflammatory and proapoptotic genes. Also, the NASH patients with fibrosis show an overexpression of fibrogenic genes, including the leptin receptor Ob-Rb.2. The up-regulated gene expression of prohibitin suggests mitochondrial dysfunction in NASH patients.     

Elevated levels of serum advanced glycation end products in patients with non-alcoholic steatohepatitis

BACKGROUND AND AIM: Advanced glycation end products (AGE), senescent macroprotein derivatives formed at an accelerated rate in diabetes, play important roles in the pathogenesis of diabetic vascular complications. Recently, AGE have also been found to be involved in insulin resistance. Although non-alcoholic steatohepatitis (NASH) is generally considered a hepatic manifestation of insulin resistance, there are no reports showing the link of AGE to NASH. The aim of this study was to evaluate the clinical significance of AGE in patients with NASH. METHODS: Glyceraldehyde-derived AGE levels were assayed from serum obtained from 106 patients: 66 with NASH, 10 with simple steatosis, and 30 controls. RESULTS: Serum glyceraldehyde-derived AGE levels (U/mL) were significantly elevated in NASH patients (9.78 +/- 3.73) compared with simple steatosis (7.17 +/- 2.28, P = 0.018) or healthy controls (6.96 +/- 2.36, P = 0.003). Moreover, these were inversely correlated with adiponectin, an adipocytokine with insulin-sensitizing and anti-inflammatory properties. In addition, immunohistochemistry of glyceraldehyde-derived AGE showed intense staining in the livers of NASH patients. CONCLUSION: The present data suggest that the sustained increase of glyceraldehyde-derived AGE could at least in part contribute to the pathogenesis of NASH. The serum glyceraldehyde-derived AGE level may be a useful biomarker for discriminating NASH from simple steatosis.     

Elevated serum iron predicts poor response to interferon treatment in patients with chronic HCV infection

To date, there are no firm clinical, demographic, biochemical, serologic, or histologic features predicting which patients with chronic hepatitis C are more likely to respond to therapy with interferon-. Serum iron, total iron-binding capacity, transferrin saturation, and ferritin were measured in the fasting state. The amount of stainable iron in liver biopsy specimens was evaluated histochemically as well. All patients received subcutaneous recombinant human IFN-2a three million units thrice weekly by self-administration. Eleven of 13 (84%) responders had low to normal serum iron levels as compared to one of 26 (4%) nonresponders (P<0.001). The serum transferrin was similar in both groups, but iron saturation was significantly lower in responders (30±10%) than in nonresponders (53±12%) (P<0.001). Serum ferritin and hepatic iron content were higher in nonresponders (NS). It is suggested that increased serum iron and transferrin saturation blunt the action of interferon, as they have opposite effects on the immune system. Iron overload can thus lead to a poor response to interferon. It remains to be seen whether reducing iron overload will improve the response to interferon therapy.     

非酒精性单纯性脂肪肝与非酒精性脂肪性肝炎患者血清脂质组学比较

目的 分析比较非酒精性单纯性脂肪肝(NAFL)与非酒精性脂肪性肝炎(NASH)患者血清脂质组学差异。方法 2015年5月～2020年5月我院诊治的NAFL患者107例和NASH患者92例,采用超高效液相色谱-串联质谱法进行血清脂质组学分析。结果 与NAFL组比,NASH组有3种游离脂肪酸(FFA,12:0、18:1和20:0)、2种二酰甘油(DAG,36:3和36:4)、16种三酰甘油(TAG,52:4、52:5、54:4、54:5、54:8、56:5、56:7、56:8、56:9、58:4、58:8、58:9、58:10、58:11、60:6和60:12)、2种磷脂酰胆碱(PC,36:5和38:6)、1种磷脂酰丝氨酸(PS,33:0)、2种溶血磷脂酰乙醇胺(LPE,36:2和39:1)、2种胆固醇脂(CE,20:4和22:6)、4种鞘磷脂(SM,36:3、38:2、40:1和42:1)、3种神经酰胺(Cer, 40:1、41:1和42:1)水平升高,3种FFA(16:1、22:4和22:5)、1种TAG(54:2)、3种PC(32:1、35:4和38:3)、5种磷脂酰肌醇(PI,32...     

Elevated plasma homocysteine concentrations as a predictor of steatohepatitis in patients with non-alcoholic fatty liver disease

BACKGROUND: Although steatosis is common in patients with severe hyperhomocysteinemia due to deficiency of cystathionine beta-synthase, there are no satisfactory data on homocysteine concentrations in patients with non-alcoholic fatty liver disease. The main aim of the present study was to evaluate the clinical significance of plasma homocysteine concentrations in patients with non-alcoholic fatty liver disease. METHODS: Seventy-one non-alcoholic fatty liver disease patients, 36 patients with chronic viral hepatitis and 30 healthy persons were enrolled in the study. Homocysteine levels were measured by high-performance liquid chromatography. Insulin, folate, vitamin B(12) and lipoprotein levels were also determined in all groups. RESULTS: Homocysteine in the non-alcoholic fatty liver disease group was found to be significantly higher than other groups. Homocysteine was found to be significantly higher in the non-alcoholic steatohepatitis group when compared with simple steatosis group. A positive correlation was found between homocysteine and triglyceride, very-low-density-lipoprotein (VLDL) cholesterol, insulin, and index of insulin resistance in the non-alcoholic fatty liver disease group, and a negative correlation was found between homocysteine and folate, or vitamin B(12) in all groups. The homocysteine threshold for the prediction of steatohepatitis was 11.935 ng/mL. Furthermore; plasma homocysteine was a statistically significant predictor for severity of necroinflammatory activity in non-alcoholic steatohepatitis. CONCLUSIONS: The plasma homocysteine concentrations were significantly higher in patients with non-alcoholic fatty liver disease, while the concentrations were not affected by chronic viral hepatitis. Plasma homocysteine is a parameter for discriminating steatohepatitis from simple steatosis. Determining the plasma homocysteine concentrations may facilitate selection of steatosis patients in whom a liver biopsy should be performed.     

非酒精性脂肪性肝炎患者外周血跨膜蛋白6超家族成员2基因表达与心血管疾病的关系

目的 探究非酒精性脂肪性肝炎(NASH)患者跨膜蛋白6超家族成员2(TM6SF2)基因表达与心血管疾病(CVD)的关系.方法 2018年9月～2020年9月我院收治的93例NASH患者,根据其是否合并CVD分为NASH组及CVD组,应用TaqMan探针法检测两组患者的TM6SF2基因rs58542936位点多态性,采用...     

壳脂胶囊对NASH小鼠肝组织血红素氧合酶-1表达的影响

目的观察壳脂胶囊对非酒精性脂肪性肝炎小鼠肝组织血红素氧合酶-1（HO-1）表达的影响。方法将C57 BL/6J小鼠20只随机分为对照组（采用蛋氨酸-胆碱充足饮食喂养）、模型组[给予高脂、蛋氨酸-胆碱缺乏（MCD）饮食喂养]、壳脂胶囊治疗组和自然恢复组。8周末检测血清转氨酶、瘦素水平,并观察肝组织脂肪变、炎症活动及纤维化程度;定量检测肝组织HO-1 mRNA的表达。结果治疗组动物肝脂肪变及炎症程度较模型组明显减轻,血清瘦素水平和肝组织HO-1表达较模型组明显降低（P〈0.05）。结论在高脂、胆碱-蛋氨酸缺乏饮食诱导的NASH小鼠,壳脂胶囊可降低肝组织HO-1表达,阻止NASH的发生发展。     

Beneficial effects of pentoxifylline on hepatic steatosis, fibrosis and necroinflammation in patients with non-alcoholic steatohepatitis

BACKGROUND AND AIM: Inhibition of tumor necrosis factor (TNF)-alpha is a logical approach to manage patients with non-alcoholic steatohepatitis (NASH). Pentoxifylline reduces TNF-alpha and alanine aminotransferase (ALT) levels in patients with NASH. The aim of the present paper was to study if pentoxifylline can improve histological injury in patients with NASH. METHODS: Nine patients (mean age 31.6 +/- 7.2 years) with histologically proven NASH and with persistently elevated ALT (>1.5 times) were given pentoxyfylline at a dosage of 400 mg t.i.d. for 12 months. Besides biochemical assessment, a repeat liver biopsy was performed and the degree of inflammation and fibrosis was compared. RESULTS: After 12 months of therapy a significant reduction in ALT (111 +/- 53 IU/L vs 45 +/- 19 IU/L, P = 0.003) and aspartate aminotransferase (AST) (61 +/- 27 IU/L vs 33 +/- 12 IU/L, P = 0.005) levels was observed. Steatosis and lobular inflammation each reduced in 55% and six (67%) patients down-staged on Brunt's staging (P = 0.009). Four out of six patients with baseline fibrosis had reduction in their fibrosis stage. CONCLUSIONS: Long-term pentoxyfylline therapy effectively achieves sustained biochemical improvement. This correlates well with histological resolution of the disease.     

Rosuvastatin improves the FGF19 analogue NGM282-associated lipid changes in patients with non-alcoholic steatohepatitis

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Prevalence and significance of autoantibodies in patients with non-alcoholic steatohepatitis

GOALS: The aim of this study is to evaluate the prevalence and the clinical and histologic correlates of autoantibodies in patients with nonalcoholic steatohepatitis (NASH). BACKGROUND: Antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) have been identified in patients with NASH. The significance of autoantibodies in NASH is uncertain. STUDY: Clinical data from patients with a histologic diagnosis of NASH at a university hospital in Chicago, Illinois between January 1999 and April 2003 were reviewed retrospectively. Seventy-four patients who were tested for autoantibodies and had no history of alcohol abuse or a systemic autoimmune disease were included. Demographic information and laboratory data were collected. Autoantibody titers > or = 1:40 were considered positive. A single pathologist reviewed all liver biopsies and scored features of NASH and identified characteristics of autoimmune hepatitis. RESULTS: Thirty-four percent of patients with NASH had positive ANA titers and 6% were ASMA positive. Demographic and laboratory parameters did not differ by ANA status, except that women were more frequently ANA positive then men (P = 0.01). The severity of steatosis, inflammation, and fibrosis on liver biopsy were similar in the ANA positive and negative groups. Only 15% of ANA positive patients with NASH had a plasma cell infiltrate on liver biopsy and there was no difference in the frequency of histologic features of autoimmune hepatitis between ANA positive and negative patients. CONCLUSIONS: Antinuclear antibodies are common in patients with NASH and most frequently represent a nonspecific antibody response that is not associated with the pattern or severity of injury on liver biopsy.     

Interactions between hepatic iron and lipid metabolism with possible relevance to steatohepatitis

The liver is an important site for iron and lipid metabolism and the main site for the interactions between these two metabolic pathways. Although conflicting results have been obtained, most studies support the hypothesis that iron plays a role in hepatic lipogenesis. Iron is an integral part of some enzymes and transporters involved in lipid metabolism and, as such, may exert a direct effect on hepatic lipid load, intrahepatic metabolic pathways and hepatic lipid secretion. On the other hand, iron in its ferrous form may indirectly affect lipid metabolism through its ability to induce oxidative stress and inflammation, a hypothesis which is currently the focus of much research in the field of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). The present review will first discuss how iron might directly interact with the metabolism of hepatic lipids and then consider a new perspective on the way in which iron may have a role in the two hit hypothesis for the progression of NAFLD via ferroportin and the iron regulatory molecule hepcidin. The review concludes that iron has important interactions with lipid metabolism in the liver that can impact on the development of NAFLD/NASH. More defined studies are required to improve our understanding of these effects.     

Alterations in lipid, carbohydrate and iron metabolism in patients with non-alcoholic steatohepatitis (NASH) and metabolic syndrome

Background

NASH (non-alcoholic steatohepatitis) is considered the hepatic manifestation of the metabolic syndrome (MS). We aimed to analyze lipid, carbohydrate, and iron metabolism in NASH.

Patients, methods

37 patients with MS (17 M/20 F, 51 +/− 15 years), elevated transaminases; 25 patients had histologically proven NASH (NAS score ≥ 5), 12 patients had toxic background (nonNASH). 37 age, sex, BMI-matched healthy controls.Lipid variables, LDL-subfractions, iron, ferritin, transferrin (T), transferrin saturation (TS), and hepcidin (H) were measured in patients/controls. Oral glucose tolerance tests were performed.

Results

NASH patients with steatosis gr. 2 and 3 (> 33% hepatic fat) had higher sd-LDL (mg/dl) concentrations than patients with steatosis gr. 1 (< 33%) (p = 0.002), nonNASH patients (p = 0.03) and controls (p = 0.001). Sd absolute (mg/dl) correlated directly with the steatosis grade only in patients with NASH and steatosis > 33% (p = 0.04).NASH-patients showed higher insulin, C-peptide and IRI values than nonNASH patients (p = 0.034; 0.032; 0.04).H was increased in patients versus controls (p < 0.001). H correlated with ferritin in MS-patients (p = 0.01), correlated directly with sd-LDL (mg/dl) (p = 0.017) and IRI (p < 0.001) and indirectly with HDL (p = 0.05) in NASH. No associations between hepatic inflammation/iron content on liver biopsy and variables of lipid metabolism were found but hepcidin correlated with hepatic inflammation in all patients and with NAS scores in NASH.

Conclusions

NASH-patients show insulin resistance and increased sd-LDL subfractions, suggesting an atherogenic profile. The correlation of H with sd-LDL and IRI, without relation to hepatic iron content suggests a putative link between inflammation, carbohydrate and lipid metabolism in NASH.     

Hepatic gene expression profile associated with non-alcoholic steatohepatitis protection by S-nitroso-N-acetylcysteine in ob/ob mice

BACKGROUND/AIMS: To understand the molecular mechanisms underlying non-alcoholic steatohepatitis (NASH) prevention by S-nitroso-N-acetylcysteine (SNAC), an NO donor that inhibits lipid peroxidation, we examined hepatic differentially expressed genes between ob/ob mice receiving or not SNAC treatment concomitantly with a methionine-choline deficient (MCD) diet. METHODS: Ob/ob mice were assigned to receive oral SNAC fed solution (MCD+SNAC group) or vehicle (MCD group) by gavage. After four weeks, histopathological analysis and microarray hybridizations were conducted in liver tissues from groups. GeneSifter system was used to identify differentially expressed genes and pathways according to Gene Ontology. RESULTS: NASH was absent in the MCD+SNAC group and no significant changes in food intake or body weight were observed in comparison to MCD group. After SNAC treatment, several genes belonging to oxidative phosphorylation, fatty acid biosynthesis, fatty acid metabolism and glutathione metabolism pathways were down-regulated in comparison to the MCD group. CONCLUSIONS: SNAC treatment promotes down regulation of several genes from fatty acid (FA) metabolism related pathways, possibly through abrogation of the cytotoxic effects of reactive oxygen species and lipid peroxides with consequent prevention of mitochondrial overload. Further studies are required to investigate the clinical implications of these findings, in attempt to develop novel therapeutic strategies for NAFLD treatment.