A novel noninvasive index for nonalcoholic steatohepatitis: a pilot study

Abstract

Objective: The potential development of a noninvasive marker predicting nonalcoholic steatohepatitis (NASH).

Methods: Thirty patients with biopsy-proven nonalcoholic fatty liver disease were evaluated by numerous anthropometric, clinical and biochemical parameters.

Results: Serum glutamic oxaloacetic transaminase (SGOT; p?=?0.027), log (erythrocyte sedimentation rate) (ESR; p?=?0.034) and homocysteine (p?=?0.041) were associated with NASH independently from gender, age and body mass index. When combined, the regression model provided R²?=?0.563 (p?=?0.001) and area under the ROC curve?=?0.873?±?0.066 (p?<?0.001).

Conclusion: This noninvasive marker, named HSENSI (acronym of homocysteine, SGOT, ESR, Nonalcoholic Steatohepatitis Index), consists of three low cost, easily measurable parameters and may accurately predict NASH.     

Progress in the search for circulating biomarkers of nonalcoholic fatty liver disease

Abstract

Context: The definitive standard for the diagnosis of nonalcoholic fatty liver disease (NAFLD) is clinico-pathological correlation, but frequently the only laboratory abnormality is an elevation of serum aminotransferases.

Objective: This has resulted in the search for more specific laboratory biomarkers.

Methods: The literature was searched for novel plasma/serum markers of NAFLD.

Results: Studies reviewed here included histologically-confirmed patients presenting some stage of NAFLD and monitored one or more novel serum/plasma biomarkers.

Conclusion: The most promising application of some of these novel biomarkers for the detection and quantification of NAFLD and particularly NASH appears to be in the combination of several into diagnostic panels.     

Mass spectrometric profiling of oxidized lipid products in human nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Oxidative stress is a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). However, the pathways that contribute to oxidative damage in vivo are poorly understood. Our aims were to define the circulating profile of lipid oxidation products in NAFLD patients, the source of these products, and assess whether their circulating levels reflect histological changes in the liver. The levels of multiple structurally specific oxidized fatty acids, including individual hydroxy-eicosatetraenoic acids (HETE), hydroxy-octadecadenoic acids (HODE), and oxo-octadecadenoic acids (oxoODE), were measured by mass spectrometry in plasma at time of liver biopsy in an initial cohort of 73 and a validation cohort of 49 consecutive patients. Of the markers monitored, 9- and 13-HODEs and 9- and 13-oxoODEs, products of free radical-mediated oxidation of linoleic acid (LA), were significantly elevated in patients with nonalcoholic steatohepatitis (NASH), compared with patients with steatosis. A strong correlation was revealed between these oxidation products and liver histopathology (inflammation, fibrosis, and steatosis). Further analyses of HODEs showed equivalent R and S chiral distribution. A risk score for NASH (oxNASH) was developed in the initial clinical cohort and shown to have high diagnostic accuracy for NASH versus steatosis in the independent validation cohort. Subjects with elevated oxNASH levels (top tertile) were 9.7-fold (P < 0.0001) more likely to have NASH than those with low levels (bottom tertile). Collectively, these findings support a key role for free radical-mediated linoleic acid oxidation in human NASH and define a risk score, oxNASH, for noninvasive detection of the presence of NASH.     

New scoring system combining the FIB-4 index and cytokeratin-18 fragments for predicting steatohepatitis and liver fibrosis in patients with nonalcoholic fatty liver disease

Purpose: To establish a new scoring system as a noninvasive tool for predicting steatohepatitis and liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

Methods: A total of 170 patients histologically diagnosed with nonalcoholic steatohepatitis (NASH) (n?=?130) or nonalcoholic fatty liver (NAFL) (n?=?40) were enrolled. We analyzed receiver operating characteristic (ROC) curves and performed multivariate analysis to predict steatohepatitis and liver fibrosis.

Results: Multivariate analysis showed that cytokeratin-18 fragment (CK18-F) levels (≥278?U/L) (odds ratio [OR], 4.46; 95% confidence interval [CI], 1.42–14.00; p?=?0.010) and the FIB-4 index (≥1.46) (OR, 4.54; 95% CI, 1.93–29.50; p?=?0.004) were independently associated with prediction of NASH. We then established a new scoring system (named the FIC-22 score) for predicting NASH using CK18-F levels and FIB-4 index. The areas under the ROC curve (AUROCs) of the FIC-22 score and NAFIC score were 0.82 (95% CI, 0.75–0.89) and 0.71 (95% CI, 0.62–0.78) (p?=?0.044). Additionally, the AUROC of the FIC-22 score for predicting the presence of fibrosis (F?≥?1) was 0.78 (95% CI, 0.70–0.85).

Conclusions: In patients with NAFLD, the FIC-22 score had high predictive accuracy not only for steatohepatitis but also for the presence of liver fibrosis.     

Evidence for regulated monoacylglycerol acyltransferase expression and activity in human liver

Intrahepatic lipid accumulation is extremely common in obese subjects and is associated with the development of insulin resistance and diabetes. Hepatic diacylglycerol and triacylglycerol synthesis predominantly occurs through acylation of glycerol-3-phosphate. However, an alternative pathway for synthesizing diacylglycerol from monoacylglycerol acyltransferases (MGAT) could also contribute to hepatic glyceride pools. MGAT activity and the expression of the three genes encoding MGAT enzymes (MOGAT1, MOGAT2, and MOGAT3) were determined in liver biopsies from obese human subjects before and after gastric bypass surgery. MOGAT expression was also assessed in liver of subjects with nonalcoholic fatty liver disease (NAFLD) or control livers. All MOGAT genes were expressed in liver, and hepatic MGAT activity was readily detectable in liver lysates. The hepatic expression of MOGAT3 was highly correlated with MGAT activity, whereas MOGAT1 and MOGAT2 expression was not, and knockdown of MOGAT3 expression attenuated MGAT activity in a liver-derived cell line. Marked weight loss following gastric bypass surgery was associated with a significant reduction in MOGAT2 and MOGAT3 expression, which were also overexpressed in NAFLD subjects. These data suggest that the MGAT pathway is active and dynamically regulated in human liver and could be an important target for pharmacologic intervention for the treatment of obesity-related insulin resistance and NAFLD.     

DRAK2 aggravates nonalcoholic fatty liver disease progression through SRSF6-associated RNA alternative splicing

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莪术醇对非酒精性脂肪性肝大鼠肝功能和肝纤维化的影响及机制*

目的:探讨莪术醇(CC)对非酒精性脂肪性肝(NAFLD)大鼠模型肝功能和肝纤维化的影响及机制。方法:采用高脂饮食构建非酒精脂肪肝炎(NASH)伴肝纤维化的大鼠模型,将60只SD大鼠随机分为:空白对照组、模型组(NASH)、NASH+复方鳖甲软肝片(CBT)组(阳性对照组)、NASH+CC组(25、50、100 mg/kg),每组10只。测量大鼠肝脏占体重的百分比,测量大鼠高密度脂蛋白(HDL)、甘油三酯(TG)、谷丙转氨酶(ALT)、谷草转氨酶(AST)水平,HE染色观察肝纤维化情况,免疫组化检测鼠肝组织α-平滑肌肌动蛋白(α-SMA)表达及肝组织核因子κB p65(NF-κB p65)的阳性染色情况,蛋白印迹(Western blot)检测α-SMA、基质金属蛋白酶-1(MMP-1)、基质金属蛋白酶抑制剂-1(TIMP-1)蛋白表达及Toll样受体-4(TLR4)、转化生长因子激活激酶-1(TAK1)、NF-κB p65、血管细胞粘附分子-1(VCAM-1)蛋白的表达情况,酶联免疫吸附法(ELISA)检测肝组织中白介素(IL-6、IL-10、IL-1β)、肿瘤坏死因子-α(TNF-α)的表达。结果:与空白对照组相比,模型组大鼠HDL、 IL-10含量、MMP-1蛋白表达量显著降低(P＜0.05),TG、ALT、AST、肝组织P65阳性率,α-SMA、TIMP-1、TLR4、TAK1、NF-κB p65、VCAM-1表达、IL-6、TNF-α及IL-1β含量显著升高(P＜0.05)。与模型组相比,CBT和CC处理后大鼠HDL、 IL-10含量、MMP-1蛋白表达量显著升高(P＜0.05),TG、ALT、AST、肝组织P65阳性率,α-SMA、TIMP-1、TLR4、TAK1、NF-κB p65、VCAM-1表达、IL-6、TNF-α及IL-1β含量显著降低(P＜0.05),其中模型+CC组以高浓度组改善最显著(P＜0.05),但各剂量改善幅度均低于模型+CBT组(P＜0.05)。结论:莪术醇通过调节TLR4、TAK1、NF-κB p65信号通路,减轻炎症反应,改善肝功能,从而缓解非酒精性脂肪肝肝肝纤维化,且在一定范围内呈浓度依赖性。     

Inhibition of TREM-1 attenuates inflammation and lipid accumulation in diet-induced nonalcoholic fatty liver disease

In the liver tissues of obese diabetic or nondiabetic patients, triggering receptor expressed on myeloid cells-1 (TREM-1) is usually found to be upregulated, thus leading to upregulation of various inflammatory cytokines and lipid accumulation. On the other hand, nonalcoholic fatty liver disease (NAFLD), characterized by excess lipid accumulation, and inflammatory injury in liver, is becoming an epidemic disease, globally. In the present study, we aimed to investigate the biological role and the underlying mechanisms of TREM-1 in NAFLD. upregulation of TREM-1 occurred in high-fat diet (HFD)-induced mice NAFLD model and oleic acid-treated HepG2 and primary mouse hepatocytes cell model at messenger RNA and protein levels. Functional studies established that overexpression of TREM-1 displayed hyperlipidemia, and increased in inflammatory indicators and lipid accumulation-related genes, which was ameliorated by knockdown of TREM-1. Our results also showed that obvious lipid accumulation and inflammatory injury occurred in the liver tissue of HFD-fed mice, while treatment with lentiviral vector short hairpin TREM showed marked improvement in tissue morphology and architecture and less lipid accumulation, thus deciphering the mechanism through which knockdown of TREM-1 ameliorated the inflammatory response and lipid accumulation of NAFLD mice through inactivation of the nuclear factor-κB (NF-κB) and PI3K/AKT signal pathways, respectively. In conclusion, TREM-1/NF-κB and TREM-1/PI3K/AKT axis could be an important mechanism in ameliorating the inflammatory response and lipid accumulation, respectively, thus shedding light on the development of novel therapeutics to the treatment of NAFLD.     

Attenuation by a Vigna nakashimae extract of nonalcoholic fatty liver disease in high-fat diet-fed mice

A Vigna nakashimae (VN) extract has been shown to have antidiabetic and anti-obesity effects. However, the mechanism underlying the effect of a VN extract on hepatic inflammation and endoplasmic reticulum (ER) stress remains unclear. In the present study, we investigated how a VN extract protects against the development of non-alcoholic fatty liver disease (NAFLD). A VN extract for 12 weeks reduced the body weight, serum metabolic parameters, cytokines, and hepatic steatosis in high-fat diet (HFD)-fed mice. A VN extract decreased HFD-induced hepatic acetyl CoA carboxylase and glucose transporter 4 expressions. In addition to the levels of high-mobility group box 1 and receptor for advanced glycation, the hepatic expression of ATF4 and caspase-3 was also reduced by a VN extract. Thus, these data indicate that a chronic VN extract prevented NAFLD through multiple mechanisms, including inflammation, ER stress, and apoptosis in the liver.     

Heritability and genetic loci of fatty liver in familial combined hyperlipidemia

VLDL overproduction, a process that is driven by an excess amount of hepatic fat, is a well-documented feature of familial combined hyperlipidemia (FCHL). The aims of this study were to investigate whether fatty liver, measured with ultrasound and as plasma alanine aminotransferase (ALT) levels, develops against a genetic background in FCHL and to identify chromosomal loci that are linked to these traits. In total, 157 FCHL family members and 20 spouses participated in this study. Radiological evidence of fatty liver was more prevalent not only in FCHL probands (40%) but also in their relatives (35%) compared with spouses (15%) (P < 0.05). Heritability calculations revealed that 20-36% of the variability in ALT levels could be attributed to genetic factors. Nonparametric quantitative trait locus (QTL) analysis revealed three significant (P < 0.001) loci with either the ultrasound or the ALT trait in the male sample: 1q42.3, 7p12-21, and 22p13-q11; none was found in the female sample or the entire group. Of these QTLs, the 7p region was consistent over time, because reanalysis with ALT levels that were determined during a visit 5 years earlier yielded similar results. This study shows that fatty liver is a heritable aspect of FCHL. Replication of particularly the 7p region is awaited.     

非酒精性脂肪肝病形成机制:补体和线粒体在其形成中的作用

非酒精性脂肪肝病(nonalcoholic fatty liver disease,NAFLD)作为一种流行性代谢疾病,一直是研究热点之一.NAFLD的形成涉及线粒体功能障碍、胰岛素抵抗、氧化应激、炎症反应等机制,而线粒体与补体在其中占据重要位置.然而,线粒体与补体在NAFLD形成过程中的内在关联及协同作用目前尚不十分...     

Candidate proteomic biomarkers for non-alcoholic fatty liver disease (steatosis and non-alcoholic steatohepatitis) discovered with mass-spectrometry: a systematic review

Context: Non-alcoholic fatty liver disease (NAFLD) is characterized by lipid accumulation in the liver which is accompanied by a series of metabolic deregulations. There are sustained research efforts focusing upon biomarker discovery for NAFLD diagnosis and its prognosis in order investigate and follow-up patients as minimally invasive as possible.

Objective: The objective of this study is to critically review proteomic studies that used mass spectrometry techniques and summarize relevant proteomic NAFLD candidate biomarkers.

Methods: Medline and Embase databases were searched from inception to December 2014.

Results: A final number of 22 records were included that identified 251 candidate proteomic biomarkers. Thirty-three biomarkers were confirmed – 14 were found in liver samples, 21 in serum samples, and two from both serum and liver samples.

Conclusion: Some of the biomarkers identified have already been extensively studied regarding their diagnostic and prognostic capacity. However, there are also more potential biomarkers that still need to be addressed in future studies.     

Liver osteopontin is required to prevent the progression of age‐related nonalcoholic fatty liver disease

Osteopontin (OPN), a senescence‐associated secretory phenotype factor, is increased in patients with nonalcoholic fatty liver disease (NAFLD). Cellular senescence has been associated with age‐dependent hepatosteatosis. Thus, we investigated the role of OPN in the age‐related hepatosteatosis. For this, human serum samples, animal models of aging, and cell lines in which senescence was induced were used. Metabolic fluxes, lipid, and protein concentration were determined. Among individuals with a normal liver, we observed a positive correlation between serum OPN levels and increasing age. This correlation with age, however, was absent in patients with NAFLD. In wild‐type (WT) mice, serum and liver OPN were increased at 10 months old (m) along with liver p53 levels and remained elevated at 20m. Markers of liver senescence increased in association with synthesis and concentration of triglycerides (TG) in 10m OPN‐deficient (KO) hepatocytes when compared to WT hepatocytes. These changes in senescence and lipid metabolism in 10m OPN‐KO mice liver were associated with the decrease of 78 kDa glucose‐regulated protein (GRP78), induction of ER stress, and the increase in fatty acid synthase and CD36 levels. OPN deficiency in senescent cells also diminished GRP78, the accumulation of intracellular TG, and the increase in CD36 levels. In 20m mice, OPN loss led to increased liver fibrosis. Finally, we showed that OPN expression in vitro and in vivo was regulated by p53. In conclusion, OPN deficiency leads to earlier cellular senescence, ER stress, and TG accumulation during aging. The p53‐OPN axis is required to inhibit the onset of age‐related hepatosteatosis.