Increased Liver Fat Research Articles

Identification of markers that distinguish adipose tissue and glucose and insulin metabolism using a multi-modal machine learning approach

The study of metabolomics has improved our knowledge of the biology behind type 2 diabetes and its related metabolic physiology. We aimed to investigate markers of adipose tissue morphology, as well as insulin and glucose metabolism in 53 non-obese male individuals. The participants underwent extensive clinical, biochemical and magnetic resonance imaging phenotyping, and we also investigated non-targeted serum metabolites. We used a multi-modal machine learning approach to evaluate which serum metabolomic compounds predicted markers of glucose and insulin metabolism, adipose tissue morphology and distribution. Fasting glucose was associated with metabolites of intracellular insulin action and beta-cell dysfunction, namely cysteine-s-sulphate and n-acetylgarginine, whereas fasting insulin was predicted by myristoleoylcarnitine, propionylcarnitine and other metabolites of beta-oxidation of fatty acids. OGTT-glucose levels at 30 min were predicted by 7-Hoca, a microbiota derived metabolite, as well as eugenol, a fatty acid. Both insulin clamp and HOMA-IR were predicted by metabolites involved in beta-oxidation of fatty acids and biodegradation of triacylglycerol, namely tartrate and 3-phosphoglycerate, as well as pyruvate, xanthine and liver fat. OGTT glucose area under curve (AUC) and OGTT insulin AUC, was associated with bile acid metabolites, subcutaneous adipocyte cell size, liver fat and fatty chain acids and derivates, such as isovalerylcarnitine. Finally, subcutaneous adipocyte size was associated with long chain fatty acids, markers of sphingolipid metabolism, increasing liver fat and dopamine-sulfate 1. Ectopic liver fat was predicted by methylmalonate, adipocyte cell size, glutathione derived metabolites and fatty chain acids. Ectopic heart fat was predicted visceral fat, gamma-glutamyl tyrosine and 2-acetamidophenol sulfate. Adipocyte cell size, age, alpha-tocopherol and blood pressure were associated with visceral fat. We identified several biomarkers associated with adipose tissue pathophysiology and insulin and glucose metabolism using a multi-modal machine learning approach. Our approach demonstrated the relative importance of serum metabolites and they outperformed traditional clinical and biochemical variables for most endpoints.

P184 Disease activity in Inflammatory Bowel Disease patients is associated with increased liver fat content during follow-up

Abstract Background Increased liver steatosis is a frequently reported condition in patients with Inflammatory Bowel Disease (IBD). Different factors, both metabolic and IBD-associated, are believed to be contribute to the pathogenesis. The aim of our study was to calculate the prevalence of liver steatosis (LS) and fibrosis (LF) in IBD patients and evaluate which factors influence changes in steatosis and fibrosis during follow-up. Methods From June 2017 to February 2018, consecutive adult IBD patients were enrolled. Demographic and bio-chemical data were collected at baseline and after 6 to 12 months. The degree of LS and LF was assessed by transient elastography (Fibroscan). LS was defined as a Controlled Attenuation Parameter (CAP) ≥248, LF as a liver stiffness value (Emed) ≥7.3 kPa and IBD disease activity as C-reactive protein (CRP) ≥10 mg/l and/or fecal calprotectin (FCP) ≥150 μg/g. Changes in LS and LF were studied using ∆CAP and ∆Emed (follow-up minus baseline). An independent sample T-test was used to analyze the mean change in ∆CAP and ∆Emed. Univariate and multivariate linear regression analyses were performed, a P-value of ≤0.05 was considered significant. Results A total of 117 IBD patients were enrolled, of which 86 patients were also seen for follow-up. Of these 86 patients, 57% were male with a mean age of 43 (16.1) years. 48% of the patients suffered from Crohn’s disease. The mean Body Mass Index (BMI) was 25.0 (4.7) kg/m2 and 28 patients (33%) had an active episode of IBD at enrollment. The prevalence of LS at baseline was 39%, the prevalence of LF at baseline 13%. The mean change in ∆CAP was 22.44 (75.7) in patients with active disease at baseline and -34.1 (67.5) in patients in remission at baseline (p=0.001). The mean change in ∆Emed was 0.40 (1.9) in patients with active disease at baseline and -0.53 (2.7) in patients in remission at baseline (p=0.075).). Using a multivariate analysis, disease activity at baseline (B=37, 95%CI 6.38–67.61,P=0.018) and LS at baseline (B=-0.4, 95%CI -0.64 – -0.23,P=0.000) were associated with an increase in LS during follow-up. In univariate analyses, no factors associated with LF during follow-up were found. Conclusion Our study reveals a high prevalence of liver steatosis and liver fibrosis in IBD patients. Active IBD at baseline was associated with an increase in liver steatosis during follow up, but not with an increase in liver fibrosis.

The influence of RS738409 I148M polymorphism of patatin-like phospholipase domain containing 3 gene on the susceptibility of non-alcoholic fatty liver disease

We aimed to elucidate the frequency of polymorphic genotypes and alleles of patatin-like phospholipase domain containing 3 rs738409 polymorphism and its possible associations with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis in a cohort from Turkey.We enrolled 200 patients diagnosed with NAFLD and genotyped for rs738409 I148M polymorphism by real-time polymerase chain reaction, particularly by melting curve analysis. SPSS analysis software was used for statistical significance. Continuous variable values were expressed as mean ± standard deviation. Significant statistical level was chosen as p = 0.05.Our results demonstrate in a cohort from Turkey that rs738409 C > G polymorphism (I148M) of patatin-like phospholipase domain containing 3 gene is significantly able to affect individuals to have NAFLD in unadjusted regression model.Consistent with the previous studies in other populations, our study group showed a significantly higher risk of having NAFLD in unadjusted regression model but not in the adjusted model indicating that non-genetic factors such as age and sex may be responsible for the association. However, independent studies need to validate our findings with a larger group of NAFLD patients, as well as in different ethnic cohorts.

The Hepatokine Adropin Is Regulated by Estrogen

Introduction: menopause is associated with weight gain, visceral adiposity and NAFLD. Rodent ovariectomy (OVX) is an accepted model for human menopause. Many OVX studies add high-fat diet or old-age to accentuate deranged phenotype. We have shown OVX alone induced weight gain and changes in liver transcriptome including downregulation of Enho, encoding for the hepatokine adropin (1). Here, we explore changes in VAT cytokine and adipokine genes, hepatic miRNA, and liver triglyceride content induced by OVX, in addition to estrogen’s role in regulation of adropin. Methods: 9-week-old C57BL/6J female mice underwent OVX or sham surgery. Groups of 10 mice were sacrificed at 6- and 12-weeks post-surgery and tissues harvested including mesenteric adipose tissue representing VAT. Liver TG was quantified using Cayman colorimetric assay. In-vitro studies performed in the murine hepatic cell-line, BNL1.ME. Adropin was measured using ELISA. Results: OVX induced adverse inflammatory cytokine & adipokine gene expression in VAT at 6-weeks post-surgery (Il18 1.1 p=0.01, Rares2 2.9, p=0.003, Retn 5.5, p=0.002) and 12-weeks post-surgery (Tnfa 2.3 p<0.001, Cxcl5 1.9 p=0.04). In the liver, OVX induced an increase in TG content at 12 weeks post-surgery (realtive increase vs sham 2.0 p=0.05). Hepatic Enho expression showed a strong inverse coorelation with total body weight gain (r= -0.7 p<0.001) and liver TG content (r=-0.4, p=0.04). In-vitro, estrogen induced an increase in Enho (relative mRNA change vs. growing medium 2.6, p=0.004); though protein level was unchanged, a trend for increased adropin was found in supernatant (relative change vs control 2.2 P=0.09). In-silico analysis of data from OVX mice treated with estrogen showed up-regulation of Enho (relative change vs vehicle, 6 p<0.001). At 6-weeks post-surgery OVX induced changes in hepatic miRNA profile with 48 miRNAs differentially expressed vs SHAM (24 up & 24 down). Integrating data from same sample RNA-SEQ and miRNA-SEQ created a network of differently expressed miRNA with oppositely differently expressed known specific mRNA targets. mIR-29, a known regulator of Enho in liver, was not found to be correlated with Enho expression in this context. Conclusions: OVX alone is sufficient to induce adverse changes in VAT gene expression and liver TG. Hepatic adropin gene expression is regulated by estrogen and its downregulation was strongly correlated to phenotypes relevant to menopause induced metabolic dysfunction, weight gain and increased liver fat. Thus, adropin should be further explored as a novel therapeutic and/or biomarker for menopause induced metabolic dysfunction. (1) Stokar, J., Gurt, I., Cohen-Kfir, E., Yakubovsky, O., Hanna, A., Assayag, E., & Dresner-Pollak, R. (2019). RNA-Seq Analysis of Ovariectomy-Induced Changes in Mouse Liver Reveals New Targets for Menopause-Associated Metabolic Derangement. Journal of the Endocrine Society, 3(Supplement_1), SUN-033.

Young Adult LEW.1WR1 Rats, a Model of Liver FAT10 Overexpression, Develop Insulin Resistance and Fatty Liver With Age

As human lifespan increases, comorbid conditions that impact quality of life have become a serious problem. FAT10 has been identified as a gene that when knocked out, improves age associated metabolic dysfunctions and increased longevity in mice (1). There is increased Fat10 expression in the liver in obesity (2,5). Providing evidence that fat10 expression may be important for triggering the transition to metabolic dysfunction in aging. Adult LEW.1WR1(1WR1) rats have increased body mass without excess abdominal fat mass compared to control rats (3). Yet, it was unclear where the excess mass was stored. We hypothesized that the 1WR1 rat would develop increased liver fat mass as a product of increased insulin resistance in response to increased liver fat10 expression over time. To test this hypothesis, we did insulin tolerance tests(7 weeks & 15 weeks), triglyceride assays, and histological analysis of the liver(23 weeks), in 1WR1 rats(n=7) and Wistar Furth (WF) rats(n=7) on control diets. We analyzed images using histological scoring for nonalcoholic fatty liver disease from the literature (4). We also assessed the slides for Mallory Denk bodies (MBs). The body mass of 1WR1 rats were increased compared to WF rat groups starting from the age of 7 weeks (391.4∓8.572g vs. 271.8∓11.62g; p <0.0006). 1WR1 rats became more insulin resistant with age, the 1WR1 rat group has increased AUC of 7 and 15 week Insulin Tolerance Tests (401.5∓23.54 vs. 245.3∓10.20 7w ITT1; p= 0.0728, 15w ITT2 328.2∓14.86 vs. 217.8∓9.; p <0.0003) compared to WF rats. 1WR1 rats have increased liver mass (11.85g∓0.7699g vs. 7.235g∓0.3864g; p=0.0006) liver triglyceride levels compared to WF rats (192.8∓21.8 mg/mL vs. 130.1∓13.075 mg/mL; p=0.0728). 1WR1 rats have increased steatosis scores(1.857∓0.2608 vs. 1.143∓0.1429;p= 0.0862) yet significantly reduced inflammatory foci level (2∓0.8165 vs. 3∓0;p= 0.007), most 1WR1 hepatocytes are enlarged (ballooned) and contained MBs compared to WF rats suggesting 1WR1 rats have already passed the early inflammation stage. Adult 1WR1 rats developed reduced insulin sensitivity and lipid accumulation in the liver. These data support our hypothesis that 1WR1 rats would develop increased liver fat and impaired insulin resistance in response to aging and show that this process may be inflammation driven. (1) Canaan et al.,PNAS. April 2014; 111 (14): 5313-5318.(2)Vidal et al., FASEB.2020, 34: 1-1,(3) Collins et al., J Endocr Soc. 2019;3(1),(4).Kleiner et al., Hepatology, 2005; 41 (6): 1313–1321,(5).Dali-Youcef et al., Hepatol Commun. 2019;3(9):1205-1220.

Abdominal Fat and Metabolic Health Markers but Not PNPLA3 Genotype Predicts Liver Fat Accumulation in Response to Excess Intake of Energy and Saturated Fat in Healthy Individuals.

Background: Saturated fat (SFA) has consistently been shown to increase liver fat, but the response appears variable at the individual level. Phenotypic and genotypic characteristics have been demonstrated to modify the hypercholesterolemic effect of SFA but it is unclear which characteristics that predict liver fat accumulation in response to a hypercaloric diet high in SFA.Objective: To identify predictors of liver fat accumulation in response to an increased intake of SFA.Design: We pooled our two previously conducted double-blind randomized trials (LIPOGAIN and LIPOGAIN-2, clinicaltrials.gov NCT01427140 and NCT02211612) and used data from the n = 49 metabolically healthy men (n = 32) and women (n = 17) randomized to a hypercaloric diet through addition of SFA-rich muffins for 7–8 weeks. Associations between clinical and metabolic variables at baseline and changes in liver fat during the intervention were analyzed using Spearman rank correlation. Linear regression was used to generate a prediction model.Results: Liver fat increased by 33% (IQR 5.4–82.7%; P < 0.0001) in response to excess energy intake and this was not associated (r = 0.17, P = 0.23) with the increase in body weight (1.9 kg; IQR 1.1–2.9 kg). Liver fat accumulation was similar (P = 0.28) in carriers (33%, IQR 14–79%) and non-carriers (33%, IQR −11 to +87%) of the PNPLA3-I148M variant. Baseline visceral and liver fat content, as well as levels of the liver enzyme γ-glutamyl transferase (GT), were the strongest positive predictors of liver fat accumulation—in contrast, adiponectin and the fatty acid 17:0 in adipose tissue were the only negative predictors in univariate analyses. A regression model based on eight clinical and metabolic variables could explain 81% of the variation in liver fat accumulation.Conclusion: Our results suggest there exists a highly inter-individual variation in the accumulation of liver fat in metabolically healthy men and women, in response to an increased energy intake from SFA and carbohydrates that occurs over circa 2 months. This marked variability in liver fat accumulation could largely be predicted by a set of clinical (e.g., GT and BMI) and metabolic (e.g., fatty acids, HOMA-IR, and adiponectin) variables assessed at baseline.

The PNPLA3-I148M Variant Confers an Antiatherogenic Lipid Profile in Insulin-resistant Patients.

The I148M (rs738409-G) variant in PNPLA3 increases liver fat content but may be protective against cardiovascular disease. Insulin resistance (IR) amplifies the effect of PNPLA3-I148M on liver fat. To study whether PNPLA3-I148M confers an antihyperlipidemic effect in insulin-resistant patients. Cross-sectional study comparing the impact of PNPLA3-I148M on plasma lipids and lipoproteins in 2 cohorts, both divided into groups based on rs738409-G allele carrier status and median HOMA-IR. Tertiary referral center. A total of 298 obese patients who underwent a liver biopsy during bariatric surgery (bariatric cohort: age 49 ± 9 years, body mass index [BMI] 43.2 ± 6.8 kg/m2), and 345 less obese volunteers in whom liver fat was measured by proton magnetic resonance spectroscopy (nonbariatric cohort: age 45 ± 14 years, BMI 29.7 ± 5.7 kg/m2). Nuclear magnetic resonance profiling of plasma lipids, lipoprotein particle subclasses and their composition. In both cohorts, individuals carrying the PNPLA3-I148M variant had significantly higher liver fat content than noncarriers. In insulin-resistant and homozygous carriers, PNPLA3-I148M exerted a distinct antihyperlipidemic effect with decreased very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) particles and their constituents, and increased high-density lipoprotein particles and their constituents, compared with noncarriers. VLDL particles were smaller and LDL particles larger in PNPLA3-I148M carriers. These changes were geometrically opposite to those due to IR. PNPLA3-I148M did not have a measurable effect in patients with lower IR, and its effect was smaller albeit still significant in the less obese than in the obese cohort. PNPLA3-I148M confers an antiatherogenic plasma lipid profile particularly in insulin-resistant individuals.

Sleeve Gastrectomy Stimulates the Hepatic Nuclear Receptors Signaling Network to Promote Increased Liver Fat Reduction and Bile Formation

Sleeve Gastrectomy Stimulates the Hepatic Nuclear Receptors Signaling Network to Promote Increased Liver Fat Reduction and Bile Formation

Role of Androgen in Liver Fat Content in Women: Metabolically Advantageous or Disadvantageous?

Objective: Androgens have a controversial effect on liver fat content (LFC) in androgen-excess females and androgen-deficient males. Polycystic ovarian syndrome (PCOS) is often associated with hyperandrogenism and nonalcoholic fatty liver disease. The aim of this study was to explore the association between hyperandrogenemia and increased liver fat content in women with PCOS, independent of other metabolic parameters.Methods: This case series study included 501 women with PCOS and 112 aged-matched controls in the outpatient department of a tertiary hospital. Anthropometric measurements, hepatic and renal function, glucose and lipid metabolism parameters, and sex hormones were examined in these women. LFC was measured by quantitative ultrasonography.Results: Women with hyperandrogenism (P<.001), an oligomenorrhoea/anovulation phenotype (P = .0064), and a diagnosis of PCOS (P<.001) had higher LFC. Androgen level is an important factor among the 9 independent risk factors of LFC (P = .0239) and may have a dimorphic impact on LFC. In all women, when the free androgen index (FAI) was less than 41.94, LFC increased with the elevated FAI; when the FAI was greater than 41.94, LFC decreased with the elevated FAI (P<.001). In women with PCOS, receiver operating characteristic curve analysis demonstrated that LFC could at least partially predict impaired glucose regulation, impaired lipid metabolism, and insulin resistance (P<.0001 for all).Conclusion: Androgen level is associated with LFC in dimorphic directions. LFC may be a predictive factor of insulin resistance, impaired glucose regulation, and impaired lipid metabolism in women with PCOS.

Evaluating acute inflammation's effects on hepatic triglyceride content in experimentally induced hyperlipidemic dairy cows in late lactation

Inflammation appears to be a predisposing factor and key component of hepatic steatosis in a variety of species. Objectives were to evaluate effects of inflammation [induced via intravenous lipopolysaccharide (LPS) infusion] on metabolism and liver lipid content in experimentally induced hyperlipidemic lactating cows. Cows (765 ± 32 kg of body weight; 273 ± 35 d in milk) were enrolled in 2 experimental periods (P); during P1 (5 d), baseline data were obtained. At the start of P2 (2 d), cows were assigned to 1 of 2 treatments: (1) intralipid plus control (IL-CON; 3 mL of saline; n = 5) or (2) intralipid plus LPS (IL-LPS; 0.375 μg of LPS/kg of body weight; n = 5). Directly following intravenous bolus (saline or LPS) administration, intralipid (20% fat emulsion) was intravenously infused continuously (200 mL/h) for 16 h to induce hyperlipidemia during which feed was removed. Blood samples were collected at -0.5, 0, 4, 8, 12, 16, 24, and 48 h relative to bolus administration, and liver biopsies were obtained on d 1 of P1 and at 16 and 48 h after the bolus. By experimental design (feed was removed during the first 16 h of d 1), dry matter intake decreased in both treatments on d 1 of P2, but the magnitude of reduction was greater in LPS cows. Dry matter intake of IL-LPS remained decreased on d 2 of P2, whereas IL-CON cows returned to baseline. Milk yield decreased in both treatments during P2, but the extent and duration was longer in LPS-infused cows. Administering LPS increased circulating LPS-binding protein (2-fold) at 8 h after bolus, after which it markedly decreased (84%) below baseline for the remainder of P2. Serum amyloid A concentrations progressively increased throughout P2 in IL-LPS cows (3-fold, relative to controls). Lipid infusion gradually increased nonesterified fatty acids and triglycerides in both treatments relative to baseline (3- and 2.5-fold, respectively). Interestingly, LPS infusion blunted the peak in nonesterified fatty acids, such that concentrations peaked (43%) higher in IL-CON compared with IL-LPS cows and heightened the increase in serum triglycerides (1.5-fold greater relative to controls). Liver fat content remained similar in IL-LPS relative to P1 at 16 h; however, hyperlipidemia alone (IL-CON) increased liver fat (36% relative to P1). No treatment differences in liver fat were observed at 48 h. In IL-LPS cows, circulating insulin increased markedly at 4 h after bolus (2-fold relative to IL-CON), and then gradually decreased during the 16 h of lipid infusion. Inducing inflammation with simultaneous hyperlipidemia altered the characteristic patterns of insulin and LPS-binding protein but did not cause fatty liver.

The association of non-alcoholic fatty liver disease and cardiac structure and function-Framingham Heart Study.

Non-alcoholic fatty liver disease confers increased risk for cardiovascular disease, including heart failure (HF), for reasons that remain unclear. Possible pathways could involve an association of liver fat with cardiac structural or functional abnormalities even after accounting for body size. We analysed N = 2356 Framingham Heart Study participants (age 52 ± 12 years, 52% women) who underwent echocardiography and standardized computed tomography measures of liver fat. In cross-sectional multivariable regression models adjusted for age, gender, cohort and cardiovascular risk factors, liver fat was positively associated with left ventricular (LV) mass (β = 1.45; 95% confidence interval (CI): 0.01, 2.88), LV wall thickness (β = 0.01; 95% CI: 0.00, 0.02), mass volume ratio (β = 0.02; 95% CI 0.01, 0.03), mitral peak velocity (E) (β = 0.83; 95% CI 0.31, 1.36) and LV filling pressure (E/e' ratio) (β = 0.16; 95% CI 0.09, 0.23); and inversely associated with global systolic longitudinal strain (β = 0.20, 95% CI 0.07, 0.33), diastolic annular velocity (e') (β = -0.12; 95% CI - 0.22, -0.03), and E/A ratio (β = -0.01; 95% CI - 0.02, -0.00). After additional adjustment for body mass index (BMI), statistical significance was attenuated for all associations except for that of greater liver fat with increased LV filling pressure, a possible precursor to HF (β = 0.11; 95% CI 0.03, 0.18). Increased liver fat was associated with multiple subclinical cardiac dysfunction measures, with most of associations mediated by obesity. Interestingly, the association of liver fat and LV filling pressure was only partially mediated by BMI, suggesting a possible direct effect of liver fat on LV filling pressure. Further confirmatory studies are needed.

Clinical and anthropometric characteristics of non-obese non-alcoholic fatty liver disease subjects in Japan.

The underlying mechanism of non-obese non-alcoholic fatty liver disease (NAFLD) has not been fully elucidated. We classified patients with NAFLD by sex and body mass index and compared their clinical features to clarify the background pathophysiology of non-obese NAFLD. A total of 404 patients with NAFLD were divided according to their body mass index (<25 [non-obese], 25 to <30 [obese], and ≥30 [severe obese]), and were further compared with 253 patients without obesity and NAFLD (non-NAFLD). The proportion of the individuals with non-obese NAFLD was 25.7% in men and 27.6% in women. The male and female non-obese NAFLD groups had lower skeletal muscle mass and muscle strength than the obese NAFLD groups. The visceral fat area, although low, was ≥100cm2 in 59.3% of men and 43.8% of women. An increase in liver fat accumulation, hepatic fibrosis, homeostasis model assessment of insulin resistance, and leptin levels was modest in the non-obese NAFLD group compared with a marked increase in the obese NAFLD groups. The muscle mass of the non-obese NAFLD group was similar to that of the non-NAFLD group, but muscle steatosis was particularly common among women. Multivariate analysis revealed that the factors contributing to increased liver fat accumulation in the non-obese NAFLD group were visceral fat area, HbA1c, myostatin, and leptin. In patients with non-obese NAFLD, a sex difference was observed in the clinical features. In addition to increased visceral fat, decreased muscle mass and muscle strength, muscle atrophy (presarcopenia), and impaired glucose tolerance were considered to be important pathophysiological factors.

Indole Alleviates Diet-Induced Hepatic Steatosis and Inflammation in a Manner Involving Myeloid Cell 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 3.

Indole is a microbiota metabolite that exerts anti-inflammatory responses. However, the relevance of indole to human non-alcoholic fatty liver disease (NAFLD) is not clear. It also remains largely unknown whether and how indole acts to protect against NAFLD. The present study sought to examine the association between the circulating levels of indole and liver fat content in human subjects and explore the mechanisms underlying indole actions in mice with diet-induced NAFLD. In a cohort of 137 subjects, the circulating levels of indole were reversely correlated with body mass index. In addition, the circulating levels of indole in obese subjects were significantly lower than those in lean subjects and were accompanied with increased liver fat content. At the whole-animal level, treatment of high-fat diet (HFD)-fed C57BL/6J mice with indole caused significant decreases in the severity of hepatic steatosis and inflammation. In cultured cells, indole treatment stimulated the expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a master regulatory gene of glycolysis, and suppressed macrophage proinflammatory activation in a PFKFB3-dependent manner. Moreover, myeloid cell-specific PFKFB3 disruption exacerbated the severity of HFD-induced hepatic steatosis and inflammation and blunted the effect of indole on alleviating diet-induced NAFLD phenotype. Taken together, our results demonstrate that indole is relevant to human NAFLD and capable of alleviating diet-induced NAFLD phenotypes in mice in a myeloid cell PFKFB3-dependent manner. Therefore, indole mimetic and/or macrophage-specific PFKFB3 activation may be the viable preventive and/or therapeutic approaches for inflammation-associated diseases including NAFLD.

Consumption of a high energy density diet triggers microbiota dysbiosis, hepatic lipidosis, and microglia activation in the nucleus of the solitary tract in rats

IntroductionObesity is a multifactorial chronic inflammatory disease. Consumption of high energy density (HED) diets is associated with hyperphagia, increased body weight and body fat accumulation, and obesity. Our lab has previously shown that short-term (4 weeks) consumption of a HED diet triggers gut microbiota dysbiosis, gut inflammation, and reorganization of the gut-brain vagal communication.ObjetivesThe aim of this study was to investigate the effect of long-term (6 months) consumption of HED diet on body composition, gut microbiome, hepatocellular lipidosis, microglia activation in the nucleus of the solitary tract, and systemic inflammation.MethodsMale Sprague–Dawley rats were fed a low energy density (LED) diet for 2 weeks and then switched to a HED diet for 26 weeks. Twenty-four-hour food intake, body weight, and body composition were measured twice a week. Blood serum and fecal samples were collected at baseline, 1, 4, 8, and 26 weeks after introduction of the HED diet. Serum samples were used to measure insulin, leptin, and inflammatory cytokines using Enzyme-linked Immunosorbent Assay. Fecal samples were assessed for 16 S rRNA genome sequencing.ResultsHED diet induced microbiota dysbiosis within a week of introducing the diet. In addition, there was significant microglia activation in the intermediate NTS and marked hepatic lipidosis after 4 weeks of HED diet. We further observed changes in the serum cytokine profile after 26 weeks of HED feeding.ConclusionsThese data suggest that microbiota dysbiosis is the first response of the organism to HED diets, followed by increased liver fat accumulation, microglia activation in the brain, and circulating levels of inflammatory markers. To our knowledge, this is the first study to present longitudinal and cross-sectional results on effect of long-term consumption of HED diets on all these parameters in a single cohort of animals.

Impact of short-term overfeeding of saturated or unsaturated fat or sugars on the gut microbiota in relation to liver fat in obese and overweight adults.

Intestinal microbiota may be causally involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). We aimed to study the effect of short-term overfeeding on human gut microbiota in relation to baseline and overfeeding-induced liver steatosis. We also asked whether the baseline microbiota composition is associated to the overfeeding-induced increase in liver fat. In a randomized trial, 38 overweight and obese subjects were assigned to consume an excess of 1000kcal/day of diets rich in either saturated fat, unsaturated fat, or simple sugars for 3 weeks. Fasting blood samples and 1H-MR spectroscopy were used for extensive clinical phenotyping as previously reported (PMID: 29844096). Fecal samples were collected for the analysis of the gut microbiota using 16S rRNA amplicon sequencing, imputed metagenomics and qPCR. Microbiota results were correlated with dietary intakes and clinical measurements before and during overfeeding. The overall community structure of the microbiota remained highly stable and personalized during overfeeding based on between-sample Bray-Curtis dissimilarity, but the relative abundances of individual taxa were altered in a diet-specific manner: overfeeding saturated fat increased Proteobacteria, while unsaturated fat increased butyrate producers. Sugar overfeeding increased Lactococcus and Escherichia coli. Imputed functions of the gut microbiota were not affected by overfeeding. Several taxa affected by overfeeding significantly correlated with the changes in host metabolic markers. The baseline levels of proteobacterial family Desulfovibrionaceae, and especially genus Bilophila, were significantly associated to overfeeding-induced liver fat increase independently of the diet arm. In general, limited overlap was observed between the overfeeding-induced microbiota changes and the liver fat-associated microbiota features at baseline. Our work indicates that the human gut microbiota is resilient to short-term overfeeding on community level, but specific taxa are altered on diet composition-dependent manner. Generalizable microbiota signatures directly associated with liver steatosis could not be identified. Instead, the carriage of Bilophila was identified as a potential novel risk factor for diet-induced liver steatosis in humans. Clinical trial registry number: NCT02133144 listed on NIH website: ClinicalTrials.gov.

Increasing liver fat is associated with progression of cardiovascular risk factors.

Nonalcoholic fatty liver disease is associated with cardiovascular risk factors in cross-sectional analyses. However, less is known about how changes in liver fat associate with the progression of cardiovascular risk factors. A substudy (n=808) drawn from the Framingham Heart Study underwent serial computed tomography scans 6years apart. We performed multivariable-adjusted regression to determine the association between changes in liver fat and progression of cardiovascular risk factors. Each standard deviation increase in liver fat was associated with adverse progression of systolic blood pressure, diastolic blood pressure, fasting glucose, high-density lipoprotein and log triglycerides. After adjusting for baseline cardiovascular risk, baselinebody mass index (BMI),and change in BMI, increasing liver fat was significantly associated with adverse changes in fasting glucose and triglycerides. In a longitudinal cohort, increasing liver fat over 6years was associated with progression of cardiovascular risk factors, even after accounting for BMI changes.

Cardiometabolic risk factor clustering in patients with deficient branched‐chain amino acid catabolism: A case‐control study

Classical organic acidemias (OAs) result from defective mitochondrial catabolism of branched-chain amino acids (BCAAs). Abnormal mitochondrial function relates to oxidative stress, ectopic lipids and insulin resistance (IR). We investigated whether genetically impaired function of mitochondrial BCAA catabolism associates with cardiometabolic risk factors, altered liver and muscle energy metabolism, and IR. In this case-control study, 31 children and young adults with propionic acidemia (PA), methylmalonic acidemia (MMA) or isovaleric acidemia (IVA) were compared with 30 healthy young humans using comprehensive metabolic phenotyping including in vivo 31 P/1 H magnetic resonance spectroscopy of liver and skeletal muscle. Among all OAs, patients with PA exhibited abdominal adiposity, IR, fasting hyperglycaemia and hypertriglyceridemia as well as increased liver fat accumulation, despite dietary energy intake within recommendations for age and sex. In contrast, patients with MMA more frequently featured higher energy intake than recommended and had a different phenotype including hepatomegaly and mildly lower skeletal muscle ATP content. In skeletal muscle of patients with PA, slightly lower inorganic phosphate levels were found. However, hepatic ATP and inorganic phosphate concentrations were not different between all OA patients and controls. In patients with IVA, no abnormalities were detected. Impaired BCAA catabolism in PA, but not in MMA or IVA, was associated with a previously unrecognised, metabolic syndrome-like phenotype with abdominal adiposity potentially resulting from ectopic lipid storage. These findings suggest the need for early cardiometabolic risk factor screening in PA.

Sugar-Sweetened Beverages Are Not Associated with Increased Liver Fat Content in Middle-Aged Men and Women

Sugar-Sweetened Beverages Are Not Associated with Increased Liver Fat Content in Middle-Aged Men and Women

Donor PNPLA3 and TM6SF2 Variant Alleles Confer Additive Risks for Graft Steatosis After Liver Transplantation.

The rs58542926 polymorphism in transmembrane 6 superfamily member 2 (TM6SF2) is a genetic factor predisposing to nonalcoholic fatty liver disease. We aimed to explore the effect of recipient and donor TM6SF2 rs58542926 genotypes on liver graft fat content after liver transplantation. Steatosis was evaluated in liver biopsies from 268 adult recipients. The influence of recipient and donor TM6SF2 genotypes, patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 genotypes, and nongenetic factors on the steatosis grade assessed 6-30 months after transplantation was analyzed by ordinal logistic regression. The presence of the TM6SF2 c.499A allele in the donor (P = 0.014), PNPLA3 c.444G allele in the donor (P < 0.001), posttransplant body mass index (P < 0.001), and serum triglycerides (P = 0.047) independently predicted increased liver fat content on multivariable analysis, whereas noncirrhotic liver disease, as an indication for liver transplantation, was associated with lower risk of steatosis (P = 0.003). The effects of the donor TM6SF2 A and PNPLA3 G alleles were additive, with an odds ratio of 4.90 (95% confidence interval, 2.01-13.00; P < 0.001), when both minor alleles were present compared with an odds ratio of 2.22 (95% confidence interval, 1.42-3.61; P = 0.002) when only one of these alleles was present. The donor TM6SF2 c.499A allele is an independent risk factor of liver graft steatosis after liver transplantation that is additive to the effects of donor PNPLA3 c.444G allele.

Comparison of liver enzymes and sonological grading in nonalcoholic fatty liver

Background: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of diffuse liver disease with a global prevalence of 25.24% and progresses to fibrosis and nonalcoholic steatohepatitis (NASH). Diagnosing NAFLD requires demonstration of increased liver fat and ultrasound imaging is widely used for screening. Specific blood tests to diagnose NAFLD and NASH are not yet available and alanine transaminase (ALT) has been used as a marker in population based studies.&#x0D; Aims and Objective: This study was aimed to compare the liver enzymes and sonological grading in NAFLD.&#x0D; Materials and Methods: A prospective hospital based observational study was carried out in 85 patients presenting to medical outpatient department (OPD) with ultrasonogical evidence of nonalcoholic fatty liver (NAFL) from January 2016 to December 2016. The patients were sent for liver enzymes and serum ALT,aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) were particularly correlated with the grade of NAFL.Data were collected on a preformed proformaand analyzed using the Statistical Package for the Social Sciences (SPSS)20.0 (SPSS Inc., Chicago, IL, USA).&#x0D; Results: In our study, mean age of the patients was 46.08 years and most of the patients were in age group of 40-60 years. Females (65.88%) were more affected than males (34.12%). There were 71 (83.5%) patients with grade 1 NAFL and 14 (16.5%) patients with grade 2 NAFL. The level of serum ALT increased with higher grades of NAFL. The mean ALT in grade 1 NAFL was 29.14±19.41 and in grade 2 NAFL was 42.19±2157; p= 0.027. Comparison of serum AST and GGT with ultrasonological grading did not show statistical difference.&#x0D; Conclusion: Serum ALT levels correlated with the ultrasonological grades of NAFLD (p = 0.027) whereas AST and ALT did not show statistical correlation with grades of fatty liver. Our study suggests for large sample size study for AST and GGT values relationship with ultrasonological grades.