Early Non-alcoholic Fatty Liver Disease Research Articles

Herbal Medicine in the Treatment of Non-Alcoholic Fatty Liver Diseases-Efficacy, Action Mechanism, and Clinical Application.

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with high prevalence in the developed countries. NAFLD has been considered as one of the leading causes of cryptogenic cirrhosis and chronic liver disease. The individuals with obesity, insulin resistance and diabetes mellitus, hyperlipidaemia, and hypertension cardiovascular disease have a high risk to develop NAFLD. The related critical pathological events are associated with the development of NAFLD including insulin resistance, lipid metabolism dysfunction, oxidative stress, inflammation, apoptosis, and fibrosis. The development of NAFLD range from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic steatosis is characterized by fat accumulation, which represents the early stage of NAFLD. Then, inflammation triggered by steatosis drives early NAFLD progression into NASH. Therefore, the amelioration of steatosis and inflammation is essential for NAFLD therapy. The herbal medicine have taken great effects on the improvement of steatosis and inflammation for treating NAFLD. It has been found out that these effects involved the multiple mechanisms underlying lipid metabolism and inflammation. In this review, we pay particular attention on herbal medicine treatment and make summary about the research of herbal medicine, including herb formula, herb extract and naturals compound on NAFLD. We make details about their protective effects, the mechanism of action involved in the amelioration steatosis and inflammation for NAFLD therapy as well as the clinical application.

A common variant in PNPLA3 is associated with age at diagnosis of NAFLD in patients from a multi-ethnic biobank

The Ile138Met variant (rs738409) in the PNPLA3 gene has the largest effect on non-alcoholic fatty liver disease (NAFLD), increasing the risk of progression to severe forms of liver disease. It remains unknown if the variant plays a role in age of NAFLD onset. We aimed to determine if rs738409 impacts on the age of NAFLD diagnosis. We applied a novel natural language processing (NLP) algorithm to a longitudinal electronic health records (EHR) dataset of >27,000 individuals with genetic data from a multi-ethnic biobank, defining NAFLD cases (n= 1,703) and confirming controls (n= 8,119). We conducted i) a survival analysis to determine if age at diagnosis differed by rs738409 genotype, ii) a receiver operating characteristics analysis to assess the utility of the rs738409 genotype in discriminating NAFLD cases from controls, and iii) a phenome-wide association study (PheWAS) between rs738409 and 10,095 EHR-derived disease diagnoses. The PNPLA3 G risk allele was associated with: i) earlier age of NAFLD diagnosis, with the strongest effect in Hispanics (hazard ratio 1.33; 95% CI 1.15-1.53; p <0.0001) among whom a NAFLD diagnosis was 15% more likely in risk allele carriers vs. non-carriers; ii) increased NAFLD risk (odds ratio 1.61; 95% CI 1.349-1.73; p <0.0001), with the strongest effect among Hispanics (odds ratio 1.43; 95% CI 1.28-1.59; p <0.0001); iii) additional liver diseases in a PheWAS (p <4.95× 10-6) where the risk variant also associated with earlier age of diagnosis. Given the role of the rs738409 in NAFLD diagnosis age, our results suggest that stratifying risk within populations known to have an enhanced risk of liver disease, such as Hispanic carriers of the rs738409 variant, would be effective in earlier identification of those who would benefit most from early NAFLD prevention and treatment strategies. Despite clear associations between the PNPLA3 rs738409 variant and elevated risk of progression from non-alcoholic fatty liver disease (NAFLD) to more severe forms of liver disease, it remains unknown if PNPLA3 rs738409 plays a role in the age of NAFLD onset. Herein, we found that this risk variant is associated with an earlier age of NAFLD and other liver disease diagnoses; an observation most pronounced in Hispanic Americans. We conclude that PNPLA3 rs738409 could be used to better understand liver disease risk within vulnerable populations and identify patients that may benefit from early prevention strategies.

Serum miR-379 expression is related to the development and progression of hypercholesterolemia in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) has a wide spectrum, eventually leading to cirrhosis and hepatic carcinogenesis. We previously reported that a series of microRNAs (miRNAs) mapped in the 14q32.2 maternally imprinted gene region (Dlk1-Dio3 mat) are related to NAFLD development and progression in a mouse model. We examined the suitability of miR-379, a circulating Dlk1-Dio3 mat miRNA, as a human NAFLD biomarker. Eighty NAFLD patients were recruited for this study. miR-379 was selected from the putative Dlk1-Dio3 mat miRNA cluster because it exhibited the greatest expression difference between NAFLD and non-alcoholic steatohepatitis in our preliminary study. Real-time PCR was used to examine the expression levels of miR-379 and miR-16 as an internal control. One patient was excluded due to low RT-PCR signal. Compared to normal controls, serum miR-379 expression was significantly up-regulated in NAFLD patients. Receiver operating characteristic curve analysis suggested that miR-379 is a suitable marker for discriminating NAFLD patients from controls, with an area under the curve value of 0.72. Serum miR-379 exhibited positive correlations with alkaline phosphatase, total cholesterol, low-density-lipoprotein cholesterol and non-high-density-lipoprotein cholesterol levels in patients with early stage NAFLD (Brunt fibrosis stage 0 to 1). The correlation between serum miR-379 and cholesterol levels was lost in early stage NAFLD patients treated with statins. Software-based predictions indicated that various energy metabolism-related genes, including insulin-like growth factor-1 (IGF-1) and IGF-1 receptor, are potential targets of miR-379. Serum miR-379 exhibits high potential as a biomarker for NAFLD. miR-379 appears to increase cholesterol lipotoxicity, leading to the development and progression of NAFLD, via interference with the expression of target genes, including those related to the IGF-1 signaling pathway. Our results could facilitate future research into the pathogenesis, diagnosis, and treatment of NAFLD.

A Nomogram for Predicting Non-Alcoholic Fatty Liver Disease in Obese Children.

PurposeNon-alcoholic fatty liver disease (NAFLD) ranges in severity from simple steatosis to steatohepatitis. Early detection of NAFLD is important for preventing the disease from progressing to become an irreversible end-stage liver disease. We developed a nomogram that allows for non-invasive screening for NAFLD in obese children.MethodsAnthropometric and laboratory data of 180 patients from our pediatric obesity clinic were collected. Diagnoses of NAFLD were based on abdominal ultrasonographic findings. The nomogram was constructed using predictors from a multivariate analysis of NAFLD risk factors.ResultsThe subjects were divided into non-NAFLD (n=67) and NAFLD groups (n=113). Factors, including sex, body mass index, abdominal circumference, blood pressure, insulin resistance, and levels of aspartate aminotransferase, alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γGT), uric acid, triglycerides, and insulin, were significantly different between the two groups (all p<0.05) as determined using homeostatis model assessment of insulin resistance (HOMA-IR). In our multivariate logistic regression analysis, elevated serum ALT, γGT, and triglyceride levels were significantly related to NAFLD development. The nomogram was established using γGT, uric acid, triglycerides, HOMA-IR, and ALT as predictors of NAFLD probability.ConclusionThe newly developed nomogram may help predict NAFLD risk in obese children. The nomogram may also allow for early NAFLD diagnosis without the need for invasive liver biopsy or expensive liver imaging, and may also allow clinicians to intervene early to prevent the progression of NAFLD to become a more advanced liver disease.

Oxidative stress biomarkers in the serum and plasma of patients with non-alcoholic fatty liver disease (NAFLD). Can plasma AGE be a marker of NAFLD? Oxidative stress biomarkers in NAFLD patients

Still little is known about the redox abnormalities in patients with non-alcoholic fatty liver disease (NAFLD). The purpose of the study was to find the relationship between enzymatic and non-enzymatic antioxidants, redox homeostasis and oxidative damage in 67-patients with NAFLD. The study population was divided into patients with non-alcoholic fatty liver (early NAFLD, n = 29) and patients with non-alcoholic steatohepatitis (advanced NAFLD, n = 38). Redox biomarkers: enzymatic antioxidants (Cu − Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR)); non-enzymatic antioxidants and redox status (reduced glutathione (GSH), total antioxidant capacity (TAC)); and oxidative damage products (total oxidant status (TOS), advanced glycation end products (AGE), malondialdehyde (MDA), and DNA/RNA oxidative damage) were determined in the serum/plasma samples. The activity of SOD, GPx, GR and levels of GSH, TOS, AGE, MDA, and DNA/RNA oxidative damage were significantly elevated in early NAFLD and advanced NAFLD group compared to controls (p < .001). There was a positive correlation between AGE, TAC and ALT activity (R = 0.34, p = .04; R = 0.36, p = .03, respectively) in advanced NAFLD group. Interestingly, ROC analysis for AGE showed good discriminatory ratio for patients with minimal steatosis (BARD score 0–1) vs. moderate steatosis (BARD score 2–4), AUC = 0.76. Plasma AGE can be a potential non-invasive biomarker differentiating NAFLD patients.

Portal Hypertension in NASH: Is It Different from Other Aetiologies?

In non-alcoholic fatty liver disease (NAFLD), an increased portal pressure is observed before signs of cirrhosis or even inflammation or fibrosis are histologically present. This review describes the differences between the mechanisms of cirrhotic portal hypertension (PHT) and PHT in non-cirrhotic NAFLD. The increased portal pressure in NAFLD is primarily a result of an increased intrahepatic vascular resistance. Vasodilation is decreased by endothelial dysfunction and the sensitivity to vasoconstrictors is increased. Furthermore, the activation of hepatic stellate cells and the presence of microvascular thrombosis could also be involved in the pathogenesis of PHT in NAFLD. Although the increased portal pressure in early NAFLD is not considered clinically significant PHT, it might play a role in the pathophysiology of NAFLD. Due to the increased intrahepatic vascular resistance, the hepatic blood flow is impaired and hence the oxygen delivery is decreased, potentially triggering transition to steatohepatitis. The underlying mechanisms of these alterations therefore represent promising targets for pharmacological treatment.

Beneficial effects of exercise on gut microbiota functionality and barrier integrity, and gut-liver crosstalk in an in vivo model of early obesity and non-alcoholic fatty liver disease.

ABSTRACTChildhood obesity has reached epidemic levels, representing one of the most serious public health concerns associated with metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). There is limited clinical experience concerning pediatric NAFLD patients, and thus the therapeutic options are scarce. The aim of this study was to evaluate the benefits of exercise on gut microbiota composition and functionality balance, and consequent effects on early obesity and NAFLD onset in an in vivo model. Juvenile (21-day-old) male Wistar rats fed a control diet or a high-fat diet (HFD) were subjected to a combined aerobic and resistance training protocol. Fecal microbiota was sequenced by an Illumina MiSeq system, and parameters related to metabolic syndrome, fecal metabolome, intestinal barrier integrity, bile acid metabolism and transport, and alteration of the gut-liver axis were measured. Exercise decreased HFD-induced body weight gain, metabolic syndrome and hepatic steatosis, as a result of its lipid metabolism modulatory capacity. Gut microbiota composition and functionality were substantially modified as a consequence of diet, age and exercise intervention. In addition, the training protocol increased Parabacteroides, Bacteroides and Flavobacterium genera, correlating with a beneficial metabolomic profile, whereas Blautia, Dysgonomonas and Porphyromonas showed an opposite pattern. Exercise effectively counteracted HFD-induced microbial imbalance, leading to intestinal barrier preservation, which, in turn, prevented deregulation of the gut-liver axis and improved bile acid homeostasis, determining the clinical outcomes of NAFLD. In conclusion, we provide scientific evidence highlighting the benefits of gut microbiota composition and functionality modulation by physical exercise protocols in the management of early obesity and NAFLD development.

Role of Noncoding RNA in Development of Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence globally, but little is known about its specific molecular mechanisms. During the past decade, noncoding RNAs (ncRNAs) have been linked to NAFLD initiation and progression. They are a class of RNAs that play an important role in regulating gene expression despite not encoding proteins. This review summarizes recent research on the relationship between ncRNAs and NAFLD. We discussed the potential applicability of ncRNAs as a biomarker for early NAFLD diagnosis and assessment of disease severity. With further study, ncRNAs should prove to be valuable new targets for NAFLD treatment and benefit the development of noninvasive diagnostic methods.

The potential role of vascular alterations and subsequent impaired liver blood flow and hepatic hypoxia in the pathophysiology of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) covers a spectrum of disease ranging from steatosis to steatohepatitis (NASH) and fibrosis, but the underlying pathophysiological mechanisms remain largely unknown. As there is currently no approved pharmacological therapy and the prevalence of NAFLD keeps increasing, understanding of its pathophysiology is crucial. We hypothesise that vascular alterations in early NAFLD play a role in the progression of the disease by inducing an increased intrahepatic vascular resistance and consequently relative hypoxia in the liver. Evidence of the detrimental effects of hypoxia in NAFLD has already been observed in liver surgery, where the outcomes of steatotic livers after ischaemia-reperfusion are worse than in healthy livers, and in obstructive sleep apnoea, which is an independent risk factor of NAFLD. Moreover, early histological damage in NAFLD is situated in the pericentral zone, which is also the first zone to be affected by a decreased oxygen tension because of the unique hepatic vacsular anatomy that causes the pericentral oxygen tension to be the lowest. Angiogenesis is also a characteristic of NAFLD, driven by hypoxia-induced mechanisms, as demonstrated in both animal models and in humans with NAFLD. Relative hypoxia is most probably induced by impaired blood flow to the liver, caused by increased intrahepatic vascular resistance. An increased intrahepatic vascular resistance early in the development of disease has been convincingly demonstrated in several animal models of NAFLD, whereas an increased portal pressure, a consequence of increased intrahepatic vascular resistance, has been proven in patients with NAFLD. Animal studies demonstrated a decreased intrahepatic effect of vasodilators and an increased reactivity to vasoconstrictors that results in an increased intrahepatic vascular resistance, thus the presence of a functional component. Pharmacological products that target vasoregulation can hence improve the intrahepatic vascular resistance and this might prevent or reverse progression of NAFLD, representing an important therapeutic option to study. Some of the drugs currently under evaluation in clinical trials for NASH have interesting properties related to the hepatic vasculature. Some other interesting drugs have been tested in animal models but further study in patients with NAFLD is warranted.In summary, in this paper we summarise the evidence that leads to the hypothesis that an increased intrahepatic vascular resistance and subsequent parenchymal hypoxia in early NAFLD is an important pathophysiological driving mechanism for the progression of the disease.

Mitochondrial dysfunction-related lipid changes occur in nonalcoholic fatty liver disease progression

Nonalcoholic fatty liver disease (NAFLD) comprises fat-accumulating conditions within hepatocytes that can cause severe liver damage and metabolic comorbidities. Studies suggest that mitochondrial dysfunction contributes to its development and progression and that the hepatic lipidome changes extensively in obesity and in NAFLD. To gain insight into the relationship between lipid metabolism and disease progression through different stages of NAFLD, we performed lipidomic analysis of plasma and liver biopsy samples from obese patients with nonalcoholic fatty liver (NAFL) or nonalcoholic steatohepatitis (NASH) and from those without NAFLD. Congruent with earlier studies, hepatic lipid levels overall increased with NAFLD. Lipid species that differed with NAFLD severity were related to mitochondrial dysfunction; specifically, hepatic cardiolipin and ubiquinone accumulated in NAFL, and levels of acylcarnitine increased with NASH. We propose that increased levels of cardiolipin and ubiquinone may help to preserve mitochondrial function in early NAFLD, but that mitochondrial function eventually fails with progression to NASH, leading to increased acylcarnitine. We also found a negative association between hepatic odd-chain phosphatidylcholine and NAFLD, which may result from mitochondrial dysfunction-related impairment of branched-chain amino acid catabolism. Overall, these data suggest a close link between accumulation of specific hepatic lipid species, mitochondrial dysfunction, and the progression of NAFLD.

Early Non-alcoholic Fatty Liver Disease in Laurence-Moon-Biedl Syndrome

Early Non-alcoholic Fatty Liver Disease in Laurence-Moon-Biedl Syndrome

Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein levels predict the presence of fibrotic nonalcoholic steatohepatitis (NASH) and NASH cirrhosis.

ObjectiveThe race for finding effective treatments for nonalcoholic fatty liver disease (NAFLD) has been slowed down by the high screen-failure rate for including patients in trials due to the lack of a noninvasive biomarker that can identify patients with significant disease. Recently, Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+ -M2BP) has shown promise in predicting liver fibrosis. The aims of this study were to evaluate the utility of WFA+ -M2BP as a biomarker to sub-classify patients with NAFLD according to their disease severity and to assess its correlation with histologic features of NAFLD.MethodsPatients undergoing biopsy for clinical suspicion of NAFLD and healthy controls were included. Patients with NAFLD were classified into: NAFL, early NASH (F0-F1), fibrotic NASH (F2-F3), and NASH cirrhosis (F4). Levels of WFA+ -M2BP in sera was measured by a HISCL™ M2BPGi™ assay kit using an automated immunoanalyzer (HISCL™-800; Sysmex, Kobe, Japan). Analysis of covariance was used to assess difference in WFA+ -M2BP between the groups and Spearman’s correlation coefficients were used to assess correlation with histological features.ResultsOur cohort consisted of 20 healthy controls and 198 patients with biopsy-proven NAFLD divided as follows: 52 with NAFL, 62 with early NASH, 52 with fibrotic NASH, and 32 with NASH cirrhosis. WFA+ -M2BP level was found to be significantly increased in the fibrotic NASH and NASH cirrhosis groups compared to healthy controls and those with early NAFLD after adjusting for age, gender and BMI. Furthermore, patients with NASH cirrhosis had significantly higher WFA+ -M2BP levels (2.4[1.5, 4.2] C.O.I (Cut-off Index)) than those with fibrotic NASH (1.2[0.79, 1.9]), p < 0.001. WFA+ -M2BP level had moderate correlation with inflammation, ballooning and NAFLD activity score and strong correlation with fibrosis stage. Additionally, ROC curve analysis demonstrated that WFA+ -M2BP accurately differentiated F2-4 from F0-F1.ConclusionIn a large cohort of patients with the full spectrum of NAFLD, WFA+ -M2BP levels predicted the presence of advanced disease and correlated strongly with fibrosis stage.

Pediatric Nonalcoholic Fatty Liver Disease: Current Thinking.

Nonalcoholic fatty liver disease (NAFLD), an increasingly prevalent paediatric disorder, is diagnosed and managed not only by both pediatric gastroenterologists/hepatologists but also frequently by the general pediatrician. This article updates recent advances in diagnostic and therapeutic approach, which may be applied to everyday practice. Diagnosis of NAFLD takes into account the risk factor profile and is a diagnosis of exclusion. Techniques such as transient elastography and specific biomarkers aimed at improving diagnosis and monitoring of NAFLD need further validation in the pediatric population. Defining the risk to develop cirrhosis seems to be of primary importance already in childhood and a combination of genetic, clinical, and environmental factors can help in monitoring and making decisions on therapy. Weight reduction therapy should be the aim of treatment approach, but the compliance is poor and pharmacological treatment would be helpful; docosahexaenoic acid, some probiotics, and vitamin E are to be considered, but evidence is not sufficient to recommend widespread use.

Biochemical Predictors of Early Onset Non-Alcoholic Fatty Liver Disease in Young Children with Obesity.

BackgroundThe prevalence of metabolic syndrome (MS) and non-alcoholic fatty liver disease (NAFLD) and their associated risk factors are not well-established in young children with obesity. The purpose of this study was to evaluate the prevalence of early onset NAFLD and identify its biochemical predictors in obese children aged less than 10 years.MethodsAnthropometric measurements, blood pressure, laboratory tests, and abdominal ultrasonography (USG) were performed in all subjects. National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria for MS diagnosis and liver enzymes and USG for NAFLD diagnosis were assessed.ResultsA total of 356 children with obesity (233 boys, 123 girls) were included, with 172 children age ≤ 10 years and 184 adolescents. The prevalence of MS was 23.3% in young children and 35.3% in adolescents (P = 0.020); while the prevalence of NAFLD was 36.0% and 70.7%, respectively (P = 0.001). In obese children aged 10 years or less, there were significant differences in levels of serum γ-glutamyltranspeptidase (γGT) (P < 0.001), triglycerides (P = 0.042), and homeostatic model assessment of insulin resistance (P < 0.001) between the non-NAFLD and the NAFLD group. Multivariate logistic regression analysis revealed significant increase in serum γGT and uric acid levels in young children.ConclusionAlthough MS and NAFLD were more prevalent in adolescents, young children also demonstrated MS and NAFLD as obesity-related complications. Elevated serum γGT and uric acid levels may serve as biochemical predictors in detecting NAFLD in young children with obesity before investigation with abdominal USG.

Dynamic mechanical analysis to assess viscoelasticity of liver tissue in a rat model of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in both developed and developing countries. A noninvasive method of detecting early stage NAFLD and distinguishing non-alcoholic steatohepatitis (NASH) from simple steatosis (SS) would be useful. The over-accumulation of fat in hepatocytes alters the physical microstructure and chemical contents of the liver tissue. This study included dynamic mechanical analysis (DMA) testing on liver samples from a rat model of NAFLD to determine whether the tissue shows any significant changes in viscoelasticity due to the histological changes. Liver steatosis was induced in 57 rats by gavage feeding of a high fat emulsion; 12 rats received a standard diet only and served as controls. Each rat provided 2 or 3 samples for DMA tests. The shear modulus and loss modulus were measured at 9 frequency points evenly-spaced in the range from 1Hz to 41Hz. The phase velocity of shear wave was calculated from the measured modulus. Multivariate T2 test was used to assess the significance of intra-group difference. The results showed significant changes (p < 0.05) in storage modulus in livers with moderate to severe (S2 to S4) steatosis in comparison with livers without steatosis (S0), while the loss modulus demonstrated significant changes earlier in stage S1, indicating that fat accumulation affects the mechanical properties of liver, particularly viscosity. However, no significant differences were observed between the steatosis grades. These results also suggest that mild inflammation may affect the mechanical properties, which requires further verification. These findings provide new information about the mechanical properties of livers with NAFLD in low frequency range and suggest that it is possible to distinguish normal livers from livers with NAFLD.

Hepatocyte vitamin D receptor regulates lipid metabolism and mediates experimental diet-induced steatosis

The pathogenesis and progression of non-alcoholic fatty liver disease (NAFLD) is still incompletely understood. Several nuclear receptors play a role in liver lipid metabolism and can promote hepatosteatosis, but the possible role of vitamin D receptor (VDR) in NAFLD has not been investigated. The expression of liver VDR was investigated in apolipoprotein E knockout (apoE(-/-)) mice on a high fat diet, in wild-type mice on methionine and choline deficient diet and in NAFLD patients with hepatosteatosis and non-alcoholic steatohepatitis. The relevance of VDR was assessed in apoE(-/-) mice by deletion of VDR or paricalcitol treatment and in human HepG2 cells by VDR transfection or silencing. The role of VDR in fibrosis was also determined in VDR knockout mice (VDR(-/-)) treated with thioacetamide. Expression of liver VDR was markedly induced in two mouse models of NAFLD, as well as in patients with hepatosteatosis, but decreased in non-alcoholic steatohepatitis. VDR deletion in high fat diet-fed apoE(-/-) mice protected against fatty liver, dyslipidemia and insulin resistance, and caused a decrease in taurine-conjugated bile acids, but did not influence fibrosis by thioacetamide. apoE(-/-)VDR(-/-) mouse livers showed decreased gene expression of CD36, DGAT2, C/EBPα and FGF21, and increased expression of PNPLA2, LIPIN1 and PGC1α. Treatment of apoE(-/-) mice on high fat diet with paricalcitol had modest opposite effects on steatosis and gene expression. Finally, this set of genes showed concordant responses when VDR was overexpressed or silenced in HepG2 cells. Induced hepatocyte VDR in NAFLD regulates key hepatic lipid metabolism genes and promotes high fat diet-associated liver steatosis. Therapeutic inhibition of liver VDR may reverse steatosis in early NAFLD. The amount of vitamin D receptor is induced early in the livers of mice and humans when they develop non-alcoholic fatty liver disease. If the gene for the vitamin D receptor is deleted, hepatic lipid metabolism changes and mice do not accumulate fat in the liver. We conclude that the vitamin D receptor can contribute to the fatty liver disease promoted by a high fat diet.

Contribution of Cyclooxygenase End Products and Oxidative Stress to Intrahepatic Endothelial Dysfunction in Early Non-Alcoholic Fatty Liver Disease

IntroductionMetabolic syndrome induces endothelial dysfunction, a surrogate marker of cardiovascular disease. In parallel, metabolic syndrome is frequently associated with non-alcoholic fatty liver disease (NAFLD), which may progress to cirrhosis. The aim of the present study was to evaluate intrahepatic endothelial dysfunction related to cyclooxygenase end products and oxidative stress as possible mechanisms involved in the pathophysiology of NAFLD.Materials and MethodsSprague-Dawley rats were fed standard diet (control-diet, CD) or high-fat-diet (HFD) for 6 weeks. Metabolic syndrome was assessed by recording arterial pressure, lipids, glycemia and rat body weight. Splanchnic hemodynamics were measured, and endothelial dysfunction was evaluated using concentration-effect curves to acetylcholine. Response was assessed with either vehicle, L-NG-Nitroarginine (L-NNA), indomethacin, tempol, or a thromboxane receptor antagonist, SQ 29548. We quantified inflammation, fibrosis, oxidative stress, nitric oxide (NO) bioavailability and thromboxane B2 levels.ResultsHFD rats exhibited metabolic syndrome together with the presence of NAFLD. Compared to control-diet livers, HFD livers showed increased hepatic vascular resistance unrelated to inflammation or fibrosis, but with decreased NO activity and increased oxidative stress. Endothelial dysfunction was observed in HFD livers compared with CD rats and improved after cyclooxygenase inhibition or tempol pre-incubation. However, pre-incubation with SQ 29548 did not modify acetylcholine response.ConclusionsOur study provides evidence that endothelial dysfunction at an early stage of NAFLD is associated with reduced NO bioavailability together with increased cyclooxygenase end products and oxidative stress, which suggests that both pathways are involved in the pathophysiology and may be worth exploring as therapeutic targets to prevent progression of the disease.

Early Detection of Nonalcoholic Fatty Liver Disease Utilizing a Novel QUS Method

Non‐alcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world, affecting 20% of the population. If left untreated, NAFLD may progress into non‐alcoholic steatohepatitis (NASH), end‐stage liver disease or hepatocellular carcinoma. While conventional ultrasound and other imaging techniques can diagnose advanced stages of fatty liver and hepatic cirrhosis, existing techniques are imprecise and not able to detect early stage NAFLD which may lead to a delayed diagnosis of complications. The goal of this study was to utilize the novel non‐invasive quantitative ultrasound (QUS) method to detect and quantify hepatic fat content at stages of steatosis. In a pilot study, 8‐week‐old male C57BL/67 mice were divided into one of three different dietary groups (n=15/group): control (Con) or one of two different atherogenic diets (Ath or Ath‐Casein). The control diet was a casein‐based purified diet (17.2% fat kcal). The Ath diet was a standard chow diet supplemental cocoa butter, cholesterol and sodium cholate (32.4% fat kcal). The Ath‐casein diet was a modification of the control diet supplemented with cocoa butter, sodium cholate and cholesterol (32.3% fat kcal). The livers of each animal received weekly ultrasound scans starting prior to being placed onto one of the three diets until euthanasia. Each week, five animals were euthanized. At euthanasia, serum was collected and the liver was harvested. Half of the liver's lateral left lobe was stained with H&amp;E (3‐μm section). Animals on the Ath‐Casein diet had significantly higher steatosis grading than animals on the Ath diet (P&lt;0.05) and control diet (P&lt;0.001). Lobular inflammation experienced a similar trend with inflammation being significantly increased in the Ath‐Casein (P&lt;0.001) and Ath (P&lt;0.01) diets compared to the control. Portal inflammation was statistically significant in both of the atherogenic diets compared to the control (P&lt;.001). Interestingly, a significant effect of liver cell injury was only visible in the Ath‐Casein group (P&lt;0.01 against Ath, and P&lt;0.0001 against control). Overall, histology revealed that animals on either of the atherogenic diets were in a worse metabolic condition. In vivo and ex vivo ultrasound of the liver display increased attenuation and backscatter in both of the atherogenic diets compared to the control. Total hepatic lipids were evaluated by the Folch method and will be further compared to ultrasound for trends corresponding to steatosis and inflammation in the liver. Total serum and hepatic cholesterol will be measured. Additionally, serum alanine aminotransferase (ALT) and tumor necrosis factor α (TNFα) will be analyzed to determine liver damage and systemic inflammation. The development of a QUS method to identify early stages of NAFLD and NASH would provide the capability to noninvasively quantify and monitor liver condition and test methods for intervention.Support or Funding InformationThis work was supported by NIH R37EB002641

Albumin Binding Function: The Potential Earliest Indicator for Liver Function Damage.

Background. Currently there is no indicator that can evaluate actual liver lesion for early stages of viral hepatitis, nonalcoholic fatty liver disease (NAFLD), and cirrhosis. Aim of this study was to investigate if albumin binding function could better reflect liver function in these liver diseases. Methods. An observational study was performed on 193 patients with early NAFLD, viral hepatitis, and cirrhosis. Cirrhosis patients were separated according to Child-Pugh score into A, B, and C subgroup. Albumin metal ion binding capacity (Ischemia-modified albumin transformed, IMAT) and fatty acid binding capacity (total binding sites, TBS) were detected. Results. Both IMAT and TBS were significantly decreased in patients with NAFLD and early hepatitis. In hepatitis group, they declined prior to changes of liver enzymes. IMAT was significantly higher in cirrhosis Child-Pugh class A group than hepatitis patients and decreased in Child-Pugh class B and class C patients. Both IMAT/albumin and TBS/albumin decreased significantly in hepatitis and NAFLD group patients. Conclusions. This is the first study to discover changes of albumin metal ion and fatty acid binding capacities prior to conventional biomarkers for liver damage in early stage of liver diseases. They may become potential earliest sensitive indicators for liver function evaluation.

Serum Bile Acid Levels in Children With Nonalcoholic Fatty Liver Disease.

Because the prevalence of obesity in children is increasing, the frequency of pediatric nonalcoholic fatty liver disease (NAFLD) is growing. A reliable noninvasive biomarker for monitoring progression of liver fibrosis would be useful. In cirrhotic persons serum bile acid (BA) levels are significantly elevated. We hypothesized that BA levels and composition in pediatric NAFLD vary depending on the stage of fibrosis. Children with NAFLD were compared with controls and classified by stages of fibrosis (NAFLD-F0, n = 27; NAFLD-F≥1, n = 65) based on liver-biopsy findings. Fasted metabolic and cholestasis status was assessed by several blood tests. BA profiles were measured by tandem mass spectrometry and compared with healthy controls (n = 105). Compared with controls, all of the NAFLD patients were overweight and showed significantly elevated glucose, insulin, aspartate transaminase, and alanine transaminase levels. Total serum BAs were lower in nonfibrotic NAFLD children than in a control cohort (1.73 vs 3.6 μmol/L) because low glycine-conjugated BA levels were incompletely compensated by increases in taurine-conjugated or unconjugated BA. In patients with fibrotic NAFLD, BA levels were lower than in controls (2.45 vs 3.6 μmol/L) but higher than in nonfibrotic patients (2.45 vs 1.73 μmol/L), and the BA pattern resembled that of healthy controls. Fibroblast growth factor 19 levels were significantly lower in both NAFLD groups than in controls (P ≤ 0.001) and were positively correlated with ursodeoxycholic acid levels. Our data indicate that serum BA levels decrease in early NAFLD and increase during progression to fibrosis. Given that BA levels are increased in cirrhotic adults, we postulate a continuous rise as NAFLD advances. BA may have a value as a noninvasive biomarker in pediatric NAFLD progression.