Steatosis Levels Research Articles

Precise evaluation of liver histology by computerized morphometry shows that steatosis influences liver stiffness measured by transient elastography in chronic hepatitis C

Liver stiffness evaluation (LSE) by Fibroscan is now widely used to assess liver fibrosis in chronic hepatitis C. Liver steatosis is a common lesion in chronic hepatitis C as in other chronic liver diseases, but its influence on LSE remains unclear. We aimed to precisely determine the influence of steatosis on LSE by using quantitative and precise morphometric measurements of liver histology. 650 patients with chronic hepatitis C, liver biopsy, and LSE were included. Liver specimens were evaluated by optical analysis (Metavir F and A, steatosis grading) and by computerized morphometry to determine the area (%, reflecting quantity) and fractal dimension (FD, reflecting architecture) of liver fibrosis and steatosis. The relationships between LSE and liver histology were better described using morphometry. LSE median was independently linked to fibrosis (area or FD), steatosis (area or FD), activity (serum AST), and IQR/LSE median. Steatosis area ≥4.0 % induced a 50 % increase in LSE result in patients with fibrosis area <9 %. In patients with IQR/LSE median ≤0.30, the rate of F0/1 patients misclassified as F ≥ 2 by Fibroscan was, respectively for steatosis area <4.0 and ≥4.0 %: 12.6 vs 32.4 % (p = 0.003). Steatosis level did not influence LSE median when fibrosis area was ≥9 %, and consequently did not increase the rate of F ≤ 3 patients misclassified as cirrhotic. A precise evaluation of liver histology by computerized morphometry shows that liver stiffness measured by Fibroscan is linked to liver fibrosis, activity, and also steatosis. High level of steatosis induces misevaluation of liver fibrosis by Fibroscan.

The effect of low and high plasma levels of insulin-like growth factor-1 (IGF-1) on the morphology of major organs: studies of Laron dwarf and bovine growth hormone transgenic (bGHTg) mice.

It is well known that somatotrophic/insulin signaling affects lifespan in experimental animals. To study the effects of insulin-like growth factor-1 (IGF-1) plasma level on the morphology of major organs, we analyzed lung, heart, liver, kidney, bone marrow, and spleen isolated from 2-year-old growth hormone receptor knockout (GHR-KO) Laron dwarf mice (with low circulating plasma levels of IGF-1) and 6-month-old bovine growth hormone transgenic (bGHTg) mice (with high circulating plasma levels of IGF-1). The ages of the two mutant strains employed in our studies were selected based on their overall ~50% survival (Laron dwarf mice live up to ~4 years and bGHTg mice up to ~1 year). Morphological analysis of the organs of long-living 2-year-old Laron dwarf mice revealed a lower biological age for their organs compared with normal littermates, with more brown adipose tissue (BAT) surrounding the main body organs, lower levels of steatosis in liver, and a lower incidence of leukocyte infiltration in different organs. By contrast, the organs of 6-month-old, short-living bGHTg mice displayed several abnormalities in liver and kidney and a reduced content of BAT around vital organs.

Deficiency of insulin-like growth factor 1 attenuates aging-induced changes in hepatic function: Role of autophagy

Circulating insulin-like growth factor-1 (IGF-1) plays a pivotal role in mediating the aging process. This study was designed to evaluate the effect of liver IGF-1 deficiency (LID) on aging-induced changes in hepatic function and underlying mechanisms, with a focus on autophagy. Plasma and liver samples were obtained from young (3-mo) and aged (24-mo) wild type (WT) and LID mice. Levels of AST, ALT, triglyceride, hepatic lipofuscin, steatosis, fibrosis, and nuclear morphology were analyzed. Western blot was employed to evaluate autophagy. Human HepG2 cells were treated with free fatty acid (FFA) to mimic hepatic aging in the absence or presence of IGF-1 siRNA. SA-β-gal activity was detected using flow cytometry and a fluorescence microplate reader. GFP-LC3 was used to assess autophagy activity in HepG2 cells. Median survival was longer in LID mice compared with WT mice. Aging was associated with elevated levels of triglyceride, AST and ALT, lipofuscin accumulation, steatosis, fibrosis and nuclear injury, which were significantly attenuated by liver IGF-1 deficiency. Levels of autophagy were suppressed in senescent livers, the effect was reversed in the liver of IGF-1 deficient mice. In HepG2 cells, FFA induced the accumulation of β-gal, which was dramatically suppressed by IGF-1 knockdown. Importantly, inhibiting autophagy using 3-methyladenine mitigated IGF-1 knockdown-induced preservation of autophagic vacuole formation and inhibition of β-gal accumulation in the presence of FFA in HepG2 cells. Our data revealed that IGF-1 deficiency ameliorated aging-induced hepatic injury, possibly through preventing a concomitant diminution in autophagy. These data provide new insight into the role of IGF-1 and autophagy in the management of aging-induced hepatic injury.

Modulation of Autophagy Affects the Hepatic Pathology in Alcoholic and Non‐alcoholic Liver Diseases

Macroautophagy is a cellular degradation process that can remove subcellular organelles including lipid droplets. We explored whether modulation of autophagy could affect the progression of alcoholic and non‐alcoholic liver diseases. C57BL/6 mice were given ethanol via intraperitoneal injection (acute) or by a 4‐week oral feeding regime (chronic), or given high fat diet for 12 weeks. An autophagy enhancer, carbamazepine or rapamycin, or an autophagy inhibitor, chloroquine, was given before the sacrifice. Activation of autophagy, level of hepatic steatosis, and blood levels of triglycerides, liver enzyme, glucose and insulin were measured. Carbamazepine, as well as rapamycin, could activate, and enhance ethanol‐induced, macroautophagy in hepatocytes in vitro and in vivo. In both acute and chronic ethanol condition, macroautophagy could be activated. The levels of hepatic steatosis and liver injury could be further enhanced by chloroquine, but reduced by carbamazepine. The protective effects of carbamazepine and rapamycin in reducing steatosis and in improving insulin sensitivity could be also demonstrated in high fat diet‐induced non‐alcoholic fatty liver condition. These findings indicate that pharmacological modulation of macroautophagy in the liver can be an effective strategy for reducing fatty liver condition and liver injury.

Commentary on: The optimal Dose of Ribavirin for Chronic Hepatitis C: From Literature Evidence to Clinical Practice

Commentary on: The optimal Dose of Ribavirin for Chronic Hepatitis C: From Literature Evidence to Clinical Practice

Caspase-1 as a central regulator of high fat diet-induced non-alcoholic steatohepatitis.

Nonalcoholic steatohepatitis (NASH) is associated with caspase activation. However, a role for pro-inflammatory caspases or inflammasomes has not been explored in diet-induced liver injury. Our aims were to examine the role of caspase-1 in high fat-induced NASH. C57BL/6 wild-type and caspase 1-knockout (Casp1-/-) mice were placed on a 12-week high fat diet. Wild-type mice on the high fat diet increased hepatic expression of pro-caspase-1 and IL-1β. Both wild-type and Casp1-/- mice on the high fat diet gained more weight than mice on a control diet. Hepatic steatosis and TG levels were increased in wild-type mice on high fat diet, but were attenuated in the absence of caspase-1. Plasma cholesterol and free fatty acids were elevated in wild-type, but not Casp1-/- mice, on high fat diet. ALT levels were elevated in both wild-type and Casp1-/- mice on high fat diet compared to control. Hepatic mRNA expression for genes associated with lipogenesis was lower in Casp1-/- mice on high fat diet compared to wild-type mice on high fat diet, while genes associated with fatty acid oxidation were not affected by diet or genotype. Hepatic Tnfα and Mcp-1 mRNA expression was increased in wild-type mice on high fat diet, but not in Casp1-/- mice on high fat diet. αSMA positive cells, Sirius red staining, and Col1α1 mRNA were increased in wild-type mice on high fat diet compared to control. Deficiency of caspase-1 prevented those increases. In summary, the absence of caspase-1 ameliorates the injurious effects of high fat diet-induced obesity on the liver. Specifically, mice deficient in caspase-1 are protected from high fat-induced hepatic steatosis, inflammation and early fibrogenesis. These data point to the inflammasome as an important therapeutic target for NASH.

Pharmacological promotion of autophagy alleviates steatosis and injury in alcoholic and non-alcoholic fatty liver conditions in mice

Pharmacological approaches can potentially improve fatty liver condition in alcoholic and non-alcoholic fatty liver diseases. The salutary effects of reducing lipid synthesis or promoting lipid oxidation have been well reported, but the benefits of increasing lipid degradation have yet to be well explored. Macroautophagy is a cellular degradation process that can remove subcellular organelles including lipid droplets. We thus investigated whether pharmacological modulation of macroautophagy could be an effective approach to alleviate fatty liver condition and liver injury. C57BL/6 mice were given ethanol via intraperitoneal injection (acute) or by a 4-week oral feeding regime (chronic), or high fat diet for 12 weeks. An autophagy enhancer, carbamazepine or rapamycin, or an autophagy inhibitor, chloroquine, was given before sacrifice. Activation of autophagy, level of hepatic steatosis, and blood levels of triglycerides, liver enzyme, glucose and insulin were measured. In both acute and chronic ethanol condition, macroautophagy was activated. Carbamazepine, as well as rapamycin, enhanced ethanol-induced macroautophagy in hepatocytes in vitro and in vivo. Hepatic steatosis and liver injury were exacerbated by chloroquine, but alleviated by carbamazepine. The protective effects of carbamazepine and rapamycin in reducing steatosis and in improving insulin sensitivity were also demonstrated in high fat diet-induced non-alcoholic fatty liver condition. These findings indicate that pharmacological modulation of macroautophagy in the liver can be an effective strategy for reducing fatty liver condition and liver injury.

Amino Acid Substitutions in the Core Region Associate with Insulin Resistance in Chronic Hepatitis C

Background/Aims: Hepatitis C virus (HCV) core protein can induce liver steatosis and glucose intolerance in transgenic mice. We aimed to clarify the association of HCV core region heterogeneity with the development of insulin resistance (IR) among patients with chronic hepatitis C (CHC). Methods: A total of 56 non-diabetic CHC genotype-1b patients were enrolled. IR was evaluated by the homeostasis model assessment (HOMA). The amino acid (aa) sequences in the core region were determined by polymerase chain reaction and direct sequencing. Results: Patients with a higher HOMA-IR (≥3.5) had a higher ratio of aa substitutions in core 70 (p = 0.025), a higher body mass index (p = 0.021) and serum total cholesterol level (p = 0.044) and presence of hepatic steatosis (≥5%) as compared with those with a lower HOMA-IR (<3.5). Multivariate analysis showed that independent factors of higher HOMA-IR were mutated aa70 (odds ratio 3.80, p = 0.033) and body mass index (odds ratio 1.20, p = 0.042). Patients with mutated aa70 had a higher serum tumor necrosis factor-α level than those with wild-type (p = 0.014). Conclusions: Substitution of the HCV-1b core region at position 70 was an independent factor associated with developing IR among patients with CHC.

Effect of Dietary Cocoa Tea (Camellia ptilophylla) Supplementation on High-Fat Diet-Induced Obesity, Hepatic Steatosis, and Hyperlipidemia in Mice

Recent studies suggested that green tea has the potential to protect against diet-induced obesity. The presence of caffeine within green tea has caused limitations. Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. To determine whether cocoa tea supplementation results in an improvement in high-fat diet-induced obesity, hyperlipidemia and hepatic steatosis, and whether such effects would be comparable to those of green tea extract, we studied six groups (n = 10) of C57BL/6 mice that were fed with (1) normal chow (N); (2) high-fat diet (21% butterfat + 0.15% cholesterol, wt/wt) (HF); (3) a high-fat diet supplemented with 2% green tea extract (HFLG); (4) a high-fat diet supplemented with 4% green tea extract (HFHG); (5) a high-fat diet supplemented with 2% cocoa tea extract (HFLC); and (6) a high-fat diet supplemented with 4% cocoa tea extract (HFHC). From the results, 2% and 4% dietary cocoa tea supplementation caused a dose-dependent decrease in (a) body weight, (b) fat pad mass, (c) liver weight, (d) total liver lipid, (e) liver triglyceride and cholesterol, and (f) plasma lipids (triglyceride and cholesterol). These data indicate that dietary cocoa tea, being naturally decaffeinated, has a beneficial effect on high-fat diet-induced obesity, hepatomegaly, hepatic steatosis, and elevated plasma lipid levels in mice, which are comparable to green tea. The present findings have provided the proof of concept that dietary cocoa tea might be of therapeutic value and could therefore provide a safer and cost effective option for patients with diet-induced metabolic syndrome.

Ethanol administration exacerbates the abnormalities in hepatic lipid oxidation in genetically obese mice

Alcohol consumption synergistically increases the risk and severity of liver damage in obese patients. To gain insight into cellular or molecular mechanisms underlying the development of fatty liver caused by ethanol-obesity synergism, we have carried out animal experiments that examine the effects of ethanol administration in genetically obese mice. Lean wild-type (WT) and obese (ob/ob) mice were subjected to ethanol feeding for 4 wk using a modified Lieber-DeCarli diet. After ethanol feeding, the ob/ob mice displayed much more pronounced changes in terms of liver steatosis and elevated plasma levels of alanine aminotransferase and aspartate aminotransferase, indicators of liver injury, compared with control mice. Mechanistic studies showed that ethanol feeding augmented the impairment of hepatic sirtuin 1 (SIRT1)-AMP-activated kinase (AMPK) signaling in the ob/ob mice. Moreover, the impairment of SIRT1-AMPK signaling was closely associated with altered hepatic functional activity of peroxisome proliferator-activated receptor γ coactivator-α and lipin-1, two vital downstream lipid regulators, which ultimately contributed to aggravated fatty liver observed in ethanol-fed ob/ob mice. Taken together, our novel findings suggest that ethanol administration to obese mice exacerbates fatty liver via impairment of the hepatic lipid metabolism pathways mediated largely by a central signaling system, the SIRT1-AMPK axis.

Increased serum levels of lipogenic enzymes in patients with severe liver steatosis

BackgroundLipid metabolism is altered in subjects with liver steatosis. FAS is a key enzyme in de novo lipogenesis and both FAS gene expression and enzymatic activity are primarily regulated by metabolic signals in the liver. Lipoprotein lipase (LPL), the rate-limiting enzyme for the hydrolysis of core triglycerides, plays a pivotal role in lipid metabolism. This study aims to investigate if circulating levels of FAS and LPL could be clinically associated with liver steatosis.MethodsIn this work, we present data obtained from a subsample of 94 subjects with liver steatosis enrolled by NUTRIEPA study, a nutritional trial in subjects with liver steatosis. Serum levels of FAS protein and LPL activity were evaluated by ELISA test and by a fluorescent method, respectively. The diagnosis and the degree of liver steatosis were based on laboratory and ecographic measurements. Statistical methods included Kruskal-Wallis analysis of variance and Wilcoxon signed-rank test, where appropriate. The χ2 test has been performed to analyse categorical variables.ResultsThe subjects with severe steatosis had significantly higher serum levels of FAS protein and LPL activity compared to subjects with mild and moderate liver steatosis. Moreover, a positive trend in serum levels of FAS expression from lower to higher degree of steatosis was also detected.ConclusionsWe describe a relationship between human liver steatosis and elevated levels of circulating lipogenic enzymes. Increased serum levels of FAS expression and LPL activity could be considered a marker of severe liver steatosis.

Adiponectin, body mass index and hepatic steatosis are independently associated with IGF-I status in obese non-diabetic women

ObjectiveLow IGF-I levels have been associated with obesity, insulin resistance, hepatic steatosis, and were shown to predict cardiovascular mortality. Adiponectin, on the other hand, was proved to have an important protective role against metabolic and cardiovascular diseases. This study investigates the relation between hepatic steatosis, adiponectin and IGF-I levels in a group of non-diabetic obese Romanian women. DesignThis cross-sectional study included 201 obese non-diabetic women, with mean age of 41.1±11.9years and mean body mass index (BMI) of 44.1±8.3kg/m2, consecutively admitted to the Endocrinology Department of a University Hospital to be evaluated as candidates for bariatric surgery. Main measured parameters included total adiponectin (detected by ELISA method), insulin, C reactive protein (CRP), and IGF-I (all by chemiluminescence methods). Insulin sensitivity was assessed using the Quantitative Insulin Sensitivity Check Index (QUICKI). Patients were considered IGF-deficient if IGF-I z score was ≤2 standard deviations from mean for age. Hepatic ultrasound was used to determine the presence of significant steatosis (SS+). ResultsSignificant steatosis was observed in 60.7% of our patients and this feature was associated with reduced total adiponectin levels (p<0.001) and lower IGF-I z scores (p<0.001). IGF-I z score negatively correlated with BMI (r=−0.283, p<0.001), alanine aminotransferase (ALT) (r=−0.130, p=0.032), gamma glutamyltransferase (GGT) (r=−0.158, p=0.018) and logarithmic transformed (log) CRP (r=−0.232, p=0.001) and positively correlated with QUICKI (r=0.148, p=0.023) and log adiponectin (r=0.216, p=0.003). The relationship between IGF-I z score and log adiponectin remained significant after adjusting for age, BMI, ALT, QUICKI and log CRP (r=0.183, p=0.012). IGF-I deficiency was present in 33.3% of these obese women. In multivariate logistic analysis, BMI (p<0.001), ALT (p=0.003), log adiponectin (p<0.001) and SS (p=0.043) proved to be independently associated with IGF-I deficiency. ConclusionsAdiponectin is significantly correlated with IGF-I z scores and, along with BMI, ALT and significant steatosis, is independently associated with IGF-I deficiency in obese non-diabetic women.

Quantification of Hepatic Steatosis With Dual-Energy Computed Tomography

The aim of this study was to compare dual-energy computed tomography (DECT) and magnetic resonance imaging (MRI) for fat quantification using tissue triglyceride concentration and histology as references in an animal model of hepatic steatosis. This animal study was approved by our institution's Research Animal Resource Center. After validation of DECT and MRI using a phantom consisting of different triglyceride concentrations, a leptin-deficient obese mouse model (ob/ob) was used for this study. Twenty mice were divided into 3 groups based on expected levels of hepatic steatosis: low (n = 6), medium (n = 7), and high (n = 7) fat. After MRI at 3 T, a DECT scan was immediately performed. The caudate lobe of the liver was harvested and analyzed for triglyceride concentration using a colorimetric assay. The left lateral lobe was also extracted for histology. Magnetic resonance imaging fat-fraction (FF) and DECT measurements (attenuation, fat density, and effective atomic number) were compared with triglycerides and histology. Phantom results demonstrated excellent correlation between triglyceride content and each of the MRI and DECT measurements (r(2) ≥ 0.96, P ≤ 0.003). In vivo, however, excellent triglyceride correlation was observed only with attenuation (r(2) = 0.89, P < 0.001) and MRI-FF (r(2) = 0.92, P < 0.001). Strong correlation existed between attenuation and MRI-FF (r(2) = 0.86, P < 0.001). Nonlinear correlation with histology was also excellent for attenuation and MRI-FF. Dual-energy computed tomography (CT) data generated by the current Gemstone Spectral Imaging analysis tool do not improve the accuracy of fat quantification in the liver beyond what CT attenuation can already provide. Furthermore, MRI may provide an excellent reference standard for liver fat quantification when validating new CT or DECT methods in human subjects.

Long‐Term Binge and Escalating Ethanol Exposure Causes Necroinflammation and Fibrosis in Rat Liver

To investigate whether "binge" and escalating alcohol exposure in the rat influences the development of pathological liver injury. Time courses for the formation of eicosanoids by cyclooxygenase (COX), oxidative stress and nitrosative stress production, expression of hypoxia-inducible factor 1 (HIF-1), cytokines, hepatic tissue necroinflammation, and fibrosis were assessed in rats during 16weeks of daily alcohol gavage. In this model of binge and escalating levels of alcohol, hepatic steatosis, necrosis, and inflammation as well as fibrosis were increased over the 16-week period. The levels of COX-2, oxidative stress, nitrosative stress, HIF-1, proinflammatory mediators (tumor necrosis factor-α, interleukin 1(β) [IL-1(β) ], IL-6), and procollagen-I were increased over the 16-week period. The content of IL-10 in rat serum increased at the end of 4 and 8weeks but decreased thereafter and was significantly decreased at 12 and 16weeks. A rat model of alcoholic liver disease (ALD) with long-term binge and escalating ethanol exposure was developed. Our data support the hypothesis that enhanced eicosanoid production by COX, oxidative stress and nitrosative stress, HIF-1, and the imbalance between pro- and anti-inflammatory cytokines plays an important role in the pathogenesis of ALD.

Neue Horizonte bei der Lebersonographie

Ultrasound-based technologies are competing more and more success-fully against computerized tomography and magnetic resonance based imaging procedures. This thanks to technological improvements as well as accumulating evidence, stemming from properly conducted controlled clinical studies. The reduced cost and radiation safety issues are additional arguments in its favor. This article reviews new developments in ultrasound medicine as applied to the liver. Emphasis lies on new data related to contrast-ultrasound (Sulphur Hexafluoride SonoVue®) which allows a dynamic analysis of liver perfusion and hence improved characterization of focal liver lesions, such as metastases of extrahepatic tumors, regenerative nodules in patients with liver cirrhosis, focal nodular hyperplasia, hepatocellular carcinoma, liver hemangioma, liver adenoma and or focal hypo-respectively hypersteatosis. This article also deals with important new techniques, which allow assessment of liver stiffness such as transient elastography (Fibroscan), ARFI (Acoustic Radiation Force Impulse) or real-time-tissue elastography. These new techniques will help us to assess and quantify the levels of liver steatosis with more precision and permit accurate follow-up measurements.

The Relationship Between Pediatric Nonalcoholic Fatty Liver Disease and Cardiovascular Risk Factors and Increased Risk of Atherosclerosis in Obese Children

To investigate the relationship between nonalcoholic fatty liver disease and cardiovascular risk factors and increased risk of atherosclerosis in obese children. The study included 80 consecutive obese children who were stratified into group 1 [ultrasonographically diagnosed with NAFLD (n = 50)] and group 2 [not diagnosed with NAFLD (n = 30)]. The control group included 30 healthy children. The groups were compared in terms of clinical cardiovascular risk factors and carotid intimal medial thickness (CIMT) (as a marker of atherosclerosis) measured using B-mode ultrasound. Mean body mass index (BMI) and blood pressure (BP), as well as the frequency of dyslipidemia, metabolic syndrome (MetS), and insulin resistance (IR), were similar in groups 1 and 2. Mean BMI and triglyceride (TG) levels, and the frequency of IR and MetS, increased significantly as the grade of steatosis increased. Mean CIMT in group 1 was significantly greater than that in the control group (P < 0.01). There was a positive correlation between CIMT and age, BP, and BMI in groups 1 and 2. In addition, CIMT was correlated with TG, low high-density lipoprotein (HDL) cholesterol, MetS, and IR only in group 1. Linear regression analysis between CIMT and age, BP, BMI, TG level, HDL cholesterol level, IR, MetS, and grade of steatosis yielded a significant difference only for grade of steatosis. Cardiovascular risk factors are more impressive and CIMT was significantly higher in group 1 than in group 2 and the control group, indicating that they are associated with greater risk of atherosclerosis and future adverse cardiovascular events.

A low level of serum total testosterone is independently associated with nonalcoholic fatty liver disease

BackgroundThe association between low serum testosterone levels, visceral adipose tissue (VAT), and metabolic syndrome is now well known. However, the relationship between hepatic steatosis and serum testosterone levels has not been extensively studied. Our aim was to investigate the association of serum total testosterone levels with nonalcoholic fatty liver disease (NAFLD), adjusting for the influence of VAT and insulin resistance.MethodsThis study is a retrospective observational cross-sectional one of healthy Korean men and was conducted at the Seoul National University Hospital Healthcare System Gangnam Center. We used data obtained from 495 men who were at least 20 years of age and who had undergone blood testing, abdominal computed tomography, and ultrasonography. Multiple logistic regression analysis was used to explore the association of serum total testosterone levels with NAFLD.ResultsMen in the low serum testosterone quintile were at a higher risk for NAFLD than men in the highest serum testosterone quintile. After adjusting for age, smoking, diabetes, exercise, BMI, triglycerides, and high-density-lipoprotein cholesterol, subjects with serum testosterone levels in the lowest quintile had an odds ratio (OR) (95% confidence interval (CI)) of 5.12 (2.43–10.77) for NAFLD (p value, 0.0004). The inverse association between serum testosterone and NAFLD was attenuated by further adjustment for variables including VAT; however, it remained statistically significant (OR (95% CI): 4.52 (2.09–9.80) in the lowest quintile; p value=0.004).ConclusionsA low serum total testosterone level was independently associated with NAFLD. This report is the first one suggesting the association remains unchanged even after controlling for VAT and insulin resistance.

Hepatic Fat Accumulation Is Modulated by the Interaction between the rs738409 Variant in the PNPLA3 Gene and the Dietary Omega6/Omega3 PUFA Intake

BackgroundA single nucleotide polymorphism (SNP), the rs738409, in the patatin like phospholipase 3 gene (PNPLA3) has been recently associated with increased hepatic steatosis and ALT levels in adults and children. Given the potential role of PNPLA3 in fatty liver development, we aimed to explore whether the influence of PNPLA3 genotype on hepatic fat in obese youth might be modulated by dietary factors such as essential omega polyunsaturated fatty acids (PUFA) intake.Materials and MethodsWe studied 127 children and adolescents (56 boys, 71 girls; 58 Caucasians; 30 African Americans and 39 Hispanics; mean age 14.7±3.3; mean BMI 30.7±7.2). The dietary composition was assessed by the Nutrition Data System for Research (NDS-R version 2011). The patients underwent a MRI study to assess the liver fat content (HFF%), ALT measurement and the genotyping of the rs738409 SNP by automatic sequencing.ResultsAs previously observed, HFF% and ALT levels varied according to the genotype in each ethnicity. ALT levels and HFF% were significantly influenced by the interaction between genotype and omega-6/omega-3 PUFA ratio (n-6/n-3), p = 0.003 and p = 0.002, respectively. HFF% and ALT levels were, in fact, related to the n-6/n-3 consumption only in subjects homozygote for the G allele of the rs738409 (r2 = 0.45, p = 0.001 and r2 = 0.40, p = 0.006, respectively).ConclusionsThese findings suggest that the association of a high dietary n-6/n-3 PUFA with fatty liver and liver damage in obese youths may be driven by a predisposing genotype.

The relationship between copper and steatosis in Wilson's disease

The histological similarities seen in Wilson's disease (WD) and non-alcoholic steatohepatitis (NASH) led us to verify possible correlations between glucose and/or lipid and/or iron metabolism alterations and hepatic steatosis in WD patients. Thirty-five WD patients (20 females, 15 males, mean age 40.1 ± 5.4 years), and 44 NASH patients (25 females, 19 males, mean age 42.8 ± 6.7 years) were enrolled in the study. BMI, total/HDL/LDL-cholesterol, triglycerides and glucose serum levels were established in all subjects. HOMA index was calculated. Percutaneous liver biopsy with quantitative evaluation of steatosis and copper tissue content was performed in all WD patients and in NASH control group. Significant difference was seen in baseline serum levels of glucose, HOMA index, total cholesterol, triglycerides, and ferritin between the WD group and NASH group (P<0.05) but steatosis scored was similar between two groups. No correlation between the level of steatosis and metabolic factors studied was highlighted. In WD, hepatic parenchymal copper concentration was 753 ± 65.3 mcg/g dry weight against 54.5 ± 16.9 mcg/g dry weight in NASH patients (P<0.05). Higher liver copper concentrations were seen in patients with severe steatosis compared to those with mild (P=0.004) and moderate, (P=0.038) steatosis. Positive significant correlation between liver copper content and steatosis scores (r=0.87; r(2)=0.76) was observed. The hepatic steatosis in WD is not induced by metabolic comorbidities but by the accumulation of copper in the liver tissue. The hypothesise that the metabolic alterations could be co-factors in the pathogenesis of steatosis in these patients cannot be excluded.

Mo1840 Serum Levels of Apoptosis Inhibitor of Macrophage (AIM) are Associated With Hepatic Fibrosis and Insulin Resistance in Patients With Hepatitis C Virus-Associated Liver Disease

Background: Apoptosis inhibitor of macrophage (AIM), also known as CD5L or Spα, is secreted by tissue macrophages. It has been reported that AIM is involved in the metabolic syndrome, which is putatively associated with the progression of chronic liver disease (CLD). In addition, we have shown that AIM is overexpressed in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) using serumproteomics. However, the association between AIM and HCV-associated CLD is not fully elucidated. Materials and Methods: 1. Serum was obtained from 6 patients with HCV-related HCC (HCC patients), 6 patients with HCV-related CLD without HCC (CLD patients), and 6 healthy volunteers. Serum proteomics was performed using 2D gel electrophoresis. 2. Serum samples were obtained from 74 HCC patients and 125 CLD patients, including 79 patients with biopsy-proved CLD. Serum levels of AIM were determined by ELISA. The homeostasis model assessmentinsulin resistance index (HOMA-IR) was calculated as fasting blood glucose × serum insulin/ 405. Results: 1. There were 27 protein spots in which the concentration in the HCC patients exceeded that of the other groups by a factor of 1.5 or more. One of these spots was identified as AIM, and differences in AIM serum levels were confirmed by ELISA. In addition, serum levels of AIM in 74 HCC patients were significantly higher than those in 125 CLD patients (4.1 vs. 1.5 μg/ml, P<0.001). 2. Serum levels of AIM were positively correlated with concentrations of type 4 collagen and negatively correlated with platelet counts, indicators of hepatic fibrosis, in all patients, and also in CLD patients without HCC. In addition, serum levels of AIM in 41 CLD patients with biopsy-proved advanced hepatic fibrosis (F2-3) were significantly higher than those in 38 patients with less-advanced hepatic fibrosis (F0-1) (1.7 vs. 1.1 μg/ml, P<0.001). Furthermore, serum levels of AIM were significantly correlated with HOMA-IR in all patients, and also in CLD patients without HCC. In contrast, these levels were not associated with hepatic steatosis or serum levels of leptin or adiponectin in biopsy-proved CLD patients. Conclusion: Our study indicated that high serum levels of AIM in patients with HCV infection are correlated with hepatic fibrosis and insulin resistance, which are possibly associated with disease progression, including HCC.