Recent concepts in non-alcoholic fatty liver disease

Clinical characteristics of patients with a family history of psoriasis: an observational epidemiological study in Chinese Han population

Introduction

Psoriasis, a chronic inflammatory skin disease, is believed to be influenced by both genetic and environmental factors. Despite this understanding, the clinical epidemiological status of psoriasis patients with a family history of the disease remains uncertain.

Methods

In this study, we participated in a multicenter observational epidemiological study involved over 1,000 hospitals and enrolled a total of 5,927 psoriasis patients. These patients were categorized into two groups based on the presence or absence of a family history of psoriasis: family history cases (896) and sporadic cases (5,031). The clinical manifestations of these two groups were analyzed through clinical classification, comorbidities, treatment response, and other relevant factors.

Results

The findings of our study indicate that individuals with a family history of psoriasis predisposition exhibit a notably elevated prevalence of psoriatic arthritis compared to those with sporadic occurrences. Moreover, patients with a family history of psoriasis display a more rapid and efficacious response to secukinumab. Additionally, individuals with moderate to severe psoriasis are at a heightened risk of developing cardiovascular and liver diseases in comparison to those with mild psoriasis, with no discernible impact of familial history on the likelihood of comorbidities.

Discussion

Our study identified the clinical characteristics of individuals with a familial predisposition to psoriasis, offering novel insights into the management and therapeutic approaches for patients with this condition.

The Effect of Diabetes Mellitus Type 1 on the Energy Metabolism of Hepatocytes: Multiphoton Microscopy and Fluorescence Lifetime Imaging

A decrease in the regenerative potential of the liver during the development of non-alcoholic fatty liver disease (NAFLD), which is observed in the vast majority of patients with diabetes mellitus type 1, significantly increases the risk of postoperative liver failure. In this regard, it is necessary to develop new approaches for the rapid intraoperative assessment of the condition of liver tissue in the presence of concomitant liver pathology. A modern label-free approach based on multiphoton microscopy, second harmonic generation (SHG), and fluorescence lifetime imaging microscopy (FLIM) allow for the evaluation of the structure of liver tissue as well as the assessment of the metabolic state of hepatocytes, even at the cellular level. We obtained optical criteria and identified specific changes in the metabolic state of hepatocytes for a reduced liver regenerative potential in the presence of induced diabetes mellitus type 1. The obtained criteria will expand the possibilities for the express assessment of the structural and functional state of liver tissue in clinical practice.

Clinical Profile of Nonalcoholic Fatty Liver Disease and its Correlation with Metabolic Syndrome and Cardiovascular Risk

Background

Nonalcoholic fatty liver disease (NAFLD) has been projected, within the next 20 years, to become the major cause of liver-related morbidity and mortality as well as a leading indication for liver transplantation. Affected South Asian Indians are at higher risk for the development of metabolic syndrome (MS), type 2 diabetes, and cardiovascular disease. There is a dearth of data related to NAFLD and its various sequelae and correlation with cardiovascular disease in South Asia.

Materials and Methods

It was an observational, prospective study conducted over 2 years on 80 patients in a tertiary care hospital in Mumbai. All patients diagnosed with NAFLD were investigated for MS according to the National Cholesterol Education Program Adult Treatment Panel III criteria, and a relationship between NAFLD and MS was correlated.

Results

MS was found to be present in 72.5% of the patients. Significant results were obtained while correlating MS parameters and fatty liver grading, implying that patients with a higher fatty liver grading were more likely to have derangements in metabolic markers.

Conclusion

NAFLD was found to be associated with an increased incidence of MS and thereby a higher risk of cardiovascular disease, warranting a high index of suspicion for both. A higher ultrasound grading of fatty liver was found to be associated with an increased incidence of MS.

Blood pressure stratification for predicting liver fibrosis risk in metabolic dysfunction associated fatty liver disease

INTRODUCTION AND OBJECTIVES

The optimal blood pressure (BP) range for patients with metabolic dysfunction-associated fatty liver disease (MAFLD) is currently unknown. This study aimed to explore the relationship between stratified BP levels and MAFLD progression.

PATIENTS AND METHODS

The data of adults who underwent yearly health check-ups were screened to establish both a cross-sectional and a 6-year longitudinal cohort of individuals with MAFLD. BP was classified into the following categories optimal, normal, high-normal, and hypertension. Liver fibrosis was diagnosed with fibrosis-4 (FIB-4) score, nonalcoholic fatty liver disease fibrosis score (NFS), and aspartate aminotransferase-to-platelet ratio index (APRI).

RESULTS

A total of 10,232 individuals were included in the cross-sectional cohort. In the MAFLD population, individuals with liver fibrosis had significantly higher BP levels and hypertension prevalence (P < 0.001) than those without. Furthermore, liver fibrosis score was significantly associated with BP levels (P < 0.001). In the 6-year longitudinal cohort of 3661 individuals with MAFLD without liver fibrosis, the incidence rates of liver fibrosis increased with increasing BP levels as follows optimal=11.20%, normal=13.90%, high-normal=19.50%, hypertension=26.20% (log-rank 22.205; P < 0.001). Cox regression analysis showed that both baseline high-normal BP (hazard ratio [HR], 1.820; P=0.019) and hypertension (HR, 2.656; P < 0.001) were predictive of liver fibrosis.

CONCLUSIONS

BP stratification may be useful in predicting the progression of MAFLD. Individuals having MAFLD with concurrent hypertension or high-normal BP are at a higher risk of liver fibrosis. These findings may provide a criteria for early intervention of MAFLD to prevent liver fibrosis.

The Role of Growth Hormone and Insulin Growth Factor 1 in the Development of Non-Alcoholic Steato-Hepatitis: A Systematic Review

Diabetic and obese patients have a high prevalence of non-alcoholic fatty liver disease (NAFLD). This condition groups a spectrum of conditions varying from simple steatosis to non-alcoholic steatohepatitis (NASH), with or without fibrosis. Multiple factors are involved in the development of NAFLD. However, details about its pathogenesis and factors that promote the progression to NASH are still missing. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) regulate metabolic, immune, and hepatic stellate cell functions. Increasing evidence suggests they may have roles in the progression from NAFLD to NASH. Following the PRISMA reporting guidelines, we conducted a systematic review to evaluate all clinical and experimental studies published in the literature correlating GH and IGF-1 to inflammation and fibrosis in NAFLD and NASH. Our results showed that GH and IGF-1 have a fundamental role in the pathogenesis of NASH, acting in slightly different ways to produce a synergic effect. Indeed, GH may mediate its protective effect in the pathogenesis of NASH by regulating lipogenesis pathways, while IGF-1 has the same effect by regulating cholesterol transport. Therefore, they could be used as therapeutic strategies in preventing NAFLD progression to NASH.

Bifidobacterium-derived short-chain fatty acids and indole compounds attenuate nonalcoholic fatty liver disease by modulating gut-liver axis

Emerging evidences about gut-microbial modulation have been accumulated in the treatment of nonalcoholic fatty liver disease (NAFLD). We evaluated the effect of Bifidobacterium breve and Bifidobacterium longum on the NAFLD pathology and explore the molecular mechanisms based on multi-omics approaches. Human stool analysis [healthy subjects (n = 25) and NAFLD patients (n = 32)] was performed to select NAFLD-associated microbiota. Six-week-old male C57BL/6 J mice were fed a normal chow diet (NC), Western diet (WD), and WD with B. breve (BB) or B. longum (BL; 109 CFU/g) for 8 weeks. Liver/body weight ratio, histopathology, serum/tool analysis, 16S rRNA-sequencing, and metabolites were examined and compared. The BB and BL groups showed improved liver histology and function based on liver/body ratios (WD 7.07 ± 0.75, BB 5.27 ± 0.47, and BL 4.86 ± 0.57) and NAFLD activity scores (WD 5.00 ± 0.10, BB 1.89 ± 1.45, and BL 1.90 ± 0.99; p < 0.05). Strain treatment showed ameliorative effects on gut barrier function. Metagenomic analysis showed treatment-specific changes in taxonomic composition. The community was mainly characterized by the significantly higher composition of the Bacteroidetes phylum among the NC and probiotic-feeding groups. Similarly, the gut metabolome was modulated by probiotics treatment. In particular, short-chain fatty acids and tryptophan metabolites were reverted to normal levels by probiotics, whereas bile acids were partially normalized to those of the NC group. The analysis of gene expression related to lipid and glucose metabolism as well as the immune response indicated the coordinative regulation of β-oxidation, lipogenesis, and systemic inflammation by probiotic treatment. BB and BL attenuate NAFLD by improving microbiome-associated factors of the gut-liver axis.

Effect of Fecal Microbiota Transplantation on Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial

Background and Aims

The clinical efficacy of fecal microbiota transplantation (FMT) in patients with non-alcoholic fatty liver disease (NAFLD) and the variant effects of FMT on lean and obese NAFLD patients remain elusive. Our study aimed to determine the clinical efficacy and safety of FMT for patients with NAFLD, elucidating its different influences on lean and obese patients with NAFLD.

Methods

We performed a randomized and controlled clinical trial. Patients in the non-FMT group were administered oral probiotics. In the FMT group, patients were randomized to receive FMT with donor stool (heterologous) via colonoscopy, followed by three enemas over 3 days. Both groups were also required to maintain a healthy diet and keep regular exercise for more than 40 min every day. They returned to the hospital for reexamination 1 month after treatment.

Results

FMT can decrease the fat accumulation in the liver by improving the gut microbiota dysbiosis, thus attenuating fatty liver disease. Significant differences in the clinical features and gut microbiota between lean and obese NAFLD patients were unveiled. Moreover, FMT had better effects on gut microbiota reconstruction in lean NAFLD than in obese NAFLD patients.

Conclusions

FMT could successfully improve the therapeutic effects on patients with NAFLD, and its clinical efficacy was higher in lean NAFLD than in obese NAFLD patients.

Translational Control in Liver Disease

Chronic liver disease is one of the biggest threats to public health worldwide. Worryingly, the incidence of liver disease is dramatically rising due to the aging of the population and the global epidemics of obesity. Both are major risk factors for chronic liver disease and adverse prognostic factors, causing an increase in mortality rate. It is of great concern that 80–95% of obese people have non-alcoholic fatty liver disease, the major precursor for liver failure and a global health challenge. Currently, the only curative treatment for advanced chronic liver disease is liver transplantation, which is, however, hampered by high treatment costs and the scarcity of donor organs. New strategies are therefore urgently needed to prevent and reverse chronic liver disease. And for that it is essential to understand better the molecular mechanisms underlying human disease. This review focuses on the abnormalities in the regulation of translation by RNA-binding proteins during chronic liver disease and their pathological impact on portal hypertension, fibrosis, steatosis, neovascularization, and cancer development.

Histological severity of nonalcoholic fatty liver disease is associated with 10-year risk for atherosclerotic cardiovascular disease

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is associated with atherosclerotic cardiovascular disease (ASCVD). However, few studies have investigated the association between the histological severity of NAFLD and ASCVD. Therefore, we investigated whether the histological severity of NAFLD is associated with ASCVD risk.

METHODS

We performed cross-sectional analysis of prospectively enrolled, biopsy-proven NAFLD patients. The 10-year ASCVD risk was assessed using the Korean Risk Prediction Model. The histological spectrum of NAFLD was classified by the nonalcoholic steatohepatitis (NASH) clinical research network histological scoring system. The association between each histological subgroup and ASCVD risk was analyzed using logistic regression analysis.

RESULTS

This study included 398 Korean subjects (mean age, 57.9 years; male, 44.2%) with biopsy-proven NAFLD and 102 no-NALFD controls. Subjects with ASCVD risk ≥ 10% showed more severe grades of hepatocellular ballooning and more advanced stages of fibrosis when compared with subjects with ASCVD risk < 10% (p < 0.05 for each). The presence of NASH (odds ratio [OR] 4.07; 95% confidence interval [CI] 1.40-11.88) or advanced fibrosis (OR 8.11; 95% CI 1.83-35.98) was independently associated with a higher risk of ASCVD even after adjustment for age, sex, body mass index, blood pressure, lipids, liver enzymes, systemic inflammation, and insulin resistance.

CONCLUSIONS

Patients with NASH or advanced fibrosis are at an increased risk of developing ASCVD compared with no-NAFLD controls or subjects with NAFL, independent of conventional metabolic risk factors for CVD. Histological information on NAFLD may be helpful to promote our understanding of extrahepatic complications, such as ASCVD, resulting from NAFLD progression.

Association of Cardiovascular Risk Factors and Metabolic Syndrome with non-alcoholic and alcoholic fatty liver disease: a retrospective analysis

BACKGROUND

Although many studies on non-alcoholic fatty liver disease (NAFLD) are underway worldwide, and several existing studies have investigated the association between NAFLD and cardiovascular risk factors, studies comparing NAFLD and alcoholic fatty liver disease (AFLD) are scarce. This study aimed to evaluate differences between the incidence of cardiovascular risk factors and metabolic syndrome in NAFLD and AFLD.

METHODS

A retrospective analysis of 913 patients who underwent abdominal computed tomography (CT) was performed to compare the incidence of cardiovascular risk factors and metabolic syndrome between NAFLD and AFLD. Subjects were divided into three groups based on criteria: healthy (n = 572), NAFLD (n = 295), and AFLD (n = 46). The healthy group had no liver disease. NAFLD was defined as fatty liver diagnosed on CT and drinking less than 140 g/week for men or 70 g/week for women. AFLD was defined as fatty liver diagnosed on CT and drinking more than 140 g/week for men or 70 g/week for women. We compared the incidence of cardiovascular risk factors and metabolic syndrome between the three groups. The relationship between each group and the metabolic syndrome risk was analyzed through multivariate logistic regression analysis.

RESULTS

No significant differences in several cardiovascular risk factors were observed between the NAFLD and AFLD groups. Upon analyzing the metabolic syndrome status in each group after making appropriate adjustments, the odds ratios (ORs) in the NAFLD (OR = 2.397, P = 0.002) and AFLD groups (OR = 4.445, P = 0.001) were found to be significantly higher than that in the healthy group; the incidence rate of metabolic syndrome was similar in the NAFLD and AFLD groups.

CONCLUSIONS

Both the NAFLD and AFLD groups had more cardiovascular risk factors and higher metabolic syndrome risk than the healthy group. Thus, the prevention of fatty liver disease, regardless of the specific type, should involve the identification of cardiovascular and metabolic syndrome risk factors. If abdominal CT reveals a fatty liver, whether NAFLD or AFLD, the risk of cardiovascular disease and metabolic syndrome should be assessed.

Life's Simple 7 and Nonalcoholic Fatty Liver Disease: The Multiethnic Study of Atherosclerosis

BACKGROUND

The American Heart Association (AHA) has defined Life's Simple 7 (LS7) as a measure of overall cardiovascular health . Nonalcoholic fatty liver disease (NAFLD) has been involved as a risk factor for cardiovascular disease. We evaluated the association between LS7 and NAFLD.

METHODS

We evaluated participants form the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. Cardiovascular health score was calculated from the Life's Simple 7 metrics. A score of 0-8 was considered inadequate, 9-10 average, and 11-14 optimal. NAFLD was defined using noncontrast cardiac computed tomography (CT) and a liver/spleen attenuation ratio (L/S) < 1. Multivariable regression were performed to evaluate the association.

RESULTS

Our cross-sectional analysis of 3901 participants showed 19% (n = 747) had optimal cardiovascular health, 33% (n = 1270) had average, and 48% (n = 1884) had inadequate. White participants were most likely to have an optimal score (51%, n = 378), whereas African American participants had the lowest proportion with optimal scores (16%, n = 120; P < 0.001). The overall prevalence of NAFLD was 18% with a distribution of 7%, 14%, and 25% in the optimal, average, and inadequate score categories, respectively (P < 0.001). Adjusted for risk factors, average and optimal health categories had lower odds of NAFLD compared to those with inadequate scores: odds ratio for average, 0.44 (95% confidence interval 0.36-0.54); optimal, odds ratio 0.19 (95% confidence interval 0.14-0.26). This association was similar across gender, race and age groups.

CONCLUSION

A more favorable cardiovascular health score was associated with a lower prevalence of NAFLD. This study may suggest a potential of Life's Simple 7 in the prevention of liver disease.

A 12-week aerobic exercise intervention results in improved metabolic function and lower adipose tissue and ectopic fat in high-fat diet fed rats

Investigations of long-term exercise interventions in humans to reverse obesity is expensive and is hampered by poor compliance and confounders. In the present study, we investigated intrahepatic and muscle fat, visceral and subcutaneous fat pads, plasma metabolic profile and skeletal muscle inflammatory markers in response to 12-week aerobic exercise in an obese rodent model. Six-week-old male Wistar rats (n=20) were randomized to chow-fed control (Control, n=5), sedentary high-fat diet (HFD, n=5), chow-fed exercise (Exercise, n=5) and HFD-fed exercise (HFD+Exercise, n=5) groups. The exercise groups were subjected to 12 weeks of motorized treadmill running at a speed of 18 m/min for 30 min/day. Differences in post-intervention measures were assessed by analysis of covariance (ANCOVA), adjusted for baseline bodyweight and pre-intervention measures, where available. Post-hoc analyses were performed with Bonferroni correction. Plasma metabolic profile was worsened and fat pads, ectopic fat in muscle and liver and inflammatory markers in skeletal muscle were elevated in sedentary HFD-fed animals relative to chow-fed controls. HFD+Exercise animals had significantly lower leptin (P=0.0004), triglycerides (P=0.007), homeostatic model assessment of insulin resistance (HOMA-IR; P=0.065), intramyocellular lipids (IMCLs; P=0.003), intrahepatic lipids (IHLs; P<0.0001), body fat% (P=0.001), subcutaneous adipose tissue (SAT; P<0.0001), visceral adipose (P<0.0001) and total fat mass (P<0.0001), relative to sedentary HFD-fed animals, despite only modestly lower bodyweight. Messenger RNA (mRNA) expression of inflammatory markers Interleukin 6 (IL6) and Tumor necrosis factor α (TNFα) were also reduced with aerobic exercise in skeletal muscle. Our results suggest that 12 weeks of aerobic exercise training is effective in improving metabolic health, fat depots, ectopic fat and inflammation even against a high-fat dietary background.

The association of the steatosis severity in fatty liver disease with coronary plaque pattern in general population

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is commonly observed in patients with cardiovascular disease (CVD). However, whether the steatosis severity of NAFLD is independently associated with coronary artery atherosclerosis is still controversial.

METHODS

Consecutive Taiwanese individuals (1502) who received coronary computed tomography angiography (CCTA) and abdominal sonography as part of a general routine health evaluation were enrolled. The association between steatosis severity, coronary atherosclerosis involvement and various plaque patterns were analysed.

RESULTS

Compared with non-steatosis, NAFLD subjects had more cardiovascular risk factors that correlated with the severity of steatosis (P for the trend <.05). The presence of atherosclerotic plaques correlated with the severity of steatosis (none: 53%, mild: 64.1%, and moderate to severe: 66.9%; P for the trend <.001). Parameters of coronary atherosclerosis, including atheroma burden obstructive score (ABOS), segment involvement score (SIS) and segment stenosis score (SSS), were higher in the moderate to severe steatosis group. After adjusting for major confounding factors, the severity of steatosis still correlated with the mixed plaque pattern (P = .043). Subgroup analysis of the risk of the presence of overall coronary and mixed plaques showed a significant association with increasing severity of steatosis, especially among these who were <65 years old, male, without metabolic syndrome, and with lower low-density lipoprotein choleseterol values.

CONCLUSION

In this general population, steatosis severity of NAFLD is associated with coronary artery atherosclerosis burden. Furthermore, steatosis severity correlated with the risk of the presence of coronary plaques, especially high-risk plaques, and was independent of traditional risk factors.

Prognostic value of non-alcoholic fatty liver disease in the elderly patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the liver manifestation of metabolic syndrome, a risk factor for mortality and cardiovascular morbidity, but we ignore the role of steatosis per se in survival, and there is very little information about this condition in the geriatric patient.

AIMS

With the present study, we investigated the independent prognostic value of NAFLD on overall mortality in the elderly.

METHODS

Within the Pianoro Project, involving people ≥ 65 years, anamnestic, clinical and laboratoristic data related to NAFLD, insulin resistance, diabetes/hyperglycemia, hypertension, obesity and dyslipidemia were collected in 804 subjects (403 male, 401 female). These subjects were followed up for mortality for a median time of 12.6 years. A multivariate analysis was performed to evaluate the prognostic value of the covariates.

RESULTS

At Kaplan-Meier estimator the presence of NAFLD seems to be associated to a lower mortality, and survival tends to increase with the increasing of steatosis grade. Cox's analysis found that survival is increased for subjects having hypercholesterolemia (RR = 0.565), NAFLD (RR = 0.777), hypertension (RR = 0.711) and in female (RR = 0.741), while it is decreased for the older subjects (RR = 3.046), in patients with hypertriglyceridemia (RR = 1.699) and for diabetics (RR = 1.797). The variables BMI and HDL-cholesterol have no role.

CONCLUSION

The data obtained in our study show that NAFLD is not associated to overall mortality in the elderly population.

Circulating Irisin Levels in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Background and Aims

Previous studies have revealed the close relation of irisin with the occurrence and development of nonalcoholic fatty liver disease (NAFLD). A systematic review and meta-analysis were conducted to evaluate the association of circulating irisin levels and NAFLD.

Methods

A systematic literature search of PubMed, Embase, Cochrane Library, Clinicaltrials.gov, WANFANG, CNKI, and CBM databases was performed for relevant articles till August 2020. The weighted mean difference (WMD) values and 95% confidence intervals (CIs) were estimated to compare the case-control studies and pooled results using meta-analysis.

Results

The meta-analysis included 5 case-control studies with a total of 1087 people. The results revealed that the circulating irisin levels showed no significant difference between NAFLD and healthy groups (WMD = 7.51 (-12.53, 27.56) ng/ml, P > 0.05). Subgroup analysis based on races showed that the average irisin levels were higher in the NAFLD group than in the healthy group (WMD = 13.53 (0.71, 26.34) ng/ml, P < 0.05) in 4 Asian studies. Subgroup analysis based on disease severity from 3 Asian studies revealed that the average irisin levels were higher in the NAFLD group than in the healthy group (WMD = 25.1 (22.85, 27.51) ng/ml, P < 0.05 and WMD = 13.52 (22.85, 27.51) ng/ml, P < 0.05, respectively). Subgroup analysis including 3 studies from Asia suggested that the irisin levels were higher in mild NAFLD than in moderate-severe NAFLD (WMD = 11.68 (9.03, 14.32) ng/ml, P < 0.05).

Conclusion

The average irisin levels might be higher in the NAFLD group than in the healthy group in Asians. The irisin levels in the mild NAFLD group might be higher than those in the moderate-severe group in Asians. It is important to monitor the changing trend of irisin levels in predicting the course of NAFLD disease and its changes.

Dietary Rapeseed Oil Supplementation Reduces Hepatic Steatosis in Obese Men-A Randomized Controlled Trial

SCOPE

Effective treatment for obesity associated non-alcoholic fatty liver disease (NAFLD) is limited. Dietary supplementation of n-3 polyunsaturated fatty acids, specifically alpha linolenic acid (ALA), can resolve intrahepatic lipid content (IHL). This study investigates the effect of daily supplementation of either refined rapeseed (RA), containing high amounts of ALA, or refined olive (OL) oil on IHL and glucose metabolism in NAFLD patients.

METHODS AND RESULTS

27 obese men consumed an isocaloric diet including either 50 g of RA or OL daily for 8 weeks. Hepatic proton magnetic resonance spectroscopy, hyperinsulinemic-euglycemic clamp studies and blood tests are performed before and at the end of the study. At 8 weeks a significant reduction in IHL is observed for RA (13.1 ± 1.6 before versus 11.1 ± 1.6% after intervention) versus OL (13.3 ± 2.5 before versus 15.7 ± 2.7% after intervention). For RA, a 21% reduction (P < 0.02) in serum free fatty acids (FFA) and a 1.68-fold increase (P = 0.03) of serum interleukin-6 (IL-6) is observed after 8 weeks.

CONCLUSION

RA has a beneficial effect on hepatic lipid metabolism as shown by reduced IHL and serum FFA. RA induced IL-6 production seems to be liver protective confirming previous results.

Ultrasound Assessment of Hepatic Steatosis by Using the Double Nakagami Distribution: A Feasibility Study

Ultrasound imaging is a first-line assessment tool for hepatic steatosis. Properties of tissue microstructures correlate with the statistical distribution of ultrasound backscattered signals, which can be described by the Nakagami distribution (a widely adopted approximation of backscattered statistics). The double Nakagami distribution (DND) model, which combines two Nakagami distributions, was recently proposed for using high-frequency ultrasound to analyze backscattered statistics corresponding to lipid droplets in the fat-infiltrated liver. This study evaluated the clinical feasibility of the DND model in ultrasound parametric imaging of hepatic steatosis by conducting clinical experiments using low-frequency ultrasound dedicated to general abdominal examinations. A total of 204 patients were recruited, and ultrasound image raw data were acquired using a 3.5 MHz array transducer for DND parametric imaging using the sliding window technique. The DND parameters were compared with hepatic steatosis grades identified histologically. A receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance. The results indicated that DND parametric imaging constructed using a sliding window with the side length of five times the pulse length of the transducer provided stable and reliable DND parameter estimations and visualized changes in the backscattered statistics caused by hepatic steatosis. The DND parameter increased with the hepatic steatosis grade. The areas under the ROC curve for identifying hepatic steatosis were 0.76 (≥mild), 0.81 (≥moderate), and 0.82 (≥severe). When using low-frequency ultrasound, DND imaging allows the clinical detection of hepatic steatosis and reflects information associated with lipid droplets in the fat-infiltrated liver.

Determination of association between nonalcoholic fatty liver disease and carotid artery atherosclerosis among nondiabetic individuals

Background:

Nonalcoholic fatty liver disease (NAFLD) is a condition characterized by the infiltration of fat in the liver cells. High levels of fat in the liver associated with increased risk of diseases like diabetes, high blood pressure and kidney disease, high cholesterol, metabolic syndrome.

Aim and Objective:

To determine the association between NAFLD and carotid intima media thickness (CIMT) among nondiabetic individuals.

Materials and Methods:

A total of 90 in-patients and outpatients (45 NAFL subjects and 45 patients with the normal liver as controls) with NAFL on abdomen ultrasound scan from Bangalore Baptist Hospital were included in our study. All the participants were subjected to a doppler study for carotid intima thickness and a blood sample (4 ml) was collected from all the subjects.

Results:

In this study, there is an elevated level of BMI, weight, dyslipidemia in NAFLD compared with controls. The present study suggests that cardiovascular risk factors such as increased carotid intima-media thickness occur more frequently among NAFLD patients compared to healthy individuals.

Conclusion:

We can conclude that NAFL has a significant association with higher cardiovascular risk in terms of carotid intima-media thickness, dyslipidemia, and hypoalphalipidemia. Lifestyle changes include weight loss, dietary changes, reduction of sedentary habits and physical exercise are recommended in the NAFL disease subjects with higher BMI and weight.

The Effects of Endoplasmic-Reticulum-Resident Selenoproteins in a Nonalcoholic Fatty Liver Disease Pig Model Induced by a High-Fat Diet

The present study aimed to investigate the intervention of selenium in the oxidative stress and apoptosis of pig livers, which were induced by a high-fat diet, and the effects of four endoplasmic reticulum (ER)-resident selenoproteins in the process. A 2 × 4 design trial was conducted that included two dietary fat levels (BD = basal diet and HFD = high-fat diet) and four dietary Se supplementation levels (0, 0.3, 1.0, and 3.0 mg/kg of the diet, in the form of sodium selenite (Na₂SeO₃)). Our results indicated that the HFD significantly increased the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, as well as the degree of steatosis, the content of malondialdehyde (MDA), the apoptotic rate, and the level of mRNA caspase-3 in the liver compared to their BD counterparts (p < 0.05). Moreover, these parameters in the HFD groups were more significantly reduced (p < 0.05) for a Se concentration of 1.0 mg/kg than for the other concentrations. Further, for both the BD and HFD, the groups supplemented with 1.0 mg/kg Se showed the highest mRNA level of selenoprotein S. In conclusion, the consumption of an HFD can induce oxidative damage and apoptosis in the liver. This shows that the supplementation of Se at 1.0 mg/kg may be the optimum concentration against damage induced by HFD, and Sels may play a key role in this process.

Deciphering the Link Between Hyperhomocysteinemia and Ceramide Metabolism in Alzheimer-Type Neurodegeneration

Aging is one of the strongest risk factor for Alzheimer's disease (AD). However, several data suggest that dyslipidemia can either contribute or serve as co-factors in AD appearance. AD could be examined as a metabolic disorder mediated by peripheral insulin resistance. Insulin resistance is associated with dyslipidemia, which results in increased hepatic ceramide generation. Hepatic steatosis induces pro-inflammatory cytokine activation which is mediated by the increased ceramides production. Ceramides levels increased in cells due to perturbation in sphingolipid metabolism and upregulated expression of enzymes involved in ceramide synthesis. Cytotoxic ceramides and related molecules generated in liver promote insulin resistance, traffic through the circulation due to injury or cell death caused by local liver inflammation, and because of their hydrophobic nature, they can cross the blood-brain barrier and thereby exert neurotoxic responses as reducing insulin signaling and increasing pro-inflammatory cytokines. These abnormalities propagate a cascade of neurodegeneration associated with oxidative stress and ceramide generation, which potentiate brain insulin resistance, apoptosis, myelin degeneration, and neuro-inflammation. Therefore, excess of toxic lipids generated in liver can cause neurodegeneration. Elevated homocysteine level is also a risk factor for AD pathology and is narrowly associated with metabolic diseases and non-alcoholic fatty liver disease. The existence of a homocysteine/ceramides signaling pathway suggests that homocysteine toxicity could be partly mediated by intracellular ceramide accumulation due to stimulation of ceramide synthase. In this article, we briefly examined the role of homocysteine and ceramide metabolism linking metabolic diseases and non-alcoholic fatty liver disease to AD. We therefore analyzed the expression of mainly enzymes implicated in ceramide and sphingolipid metabolism and demonstrated deregulation of de novo ceramide biosynthesis and S1P metabolism in liver and brain of hyperhomocysteinemic mice.

Decreased lung function is associated with risk of developing non-alcoholic fatty liver disease: A longitudinal cohort study

BACKGROUND

Decreased lung function is associated with non-alcoholic fatty liver disease (NAFLD), based on linking mechanisms such as insulin resistance and systemic inflammation However, its association with the risk of developing NAFLD is unclear. Our aim was to investigate whether baseline lung function is associated with incident NAFLD in middle-aged healthy Koreans.

METHODS

A cohort study of 96,104 subjects (mean age: 35.7 years) without NAFLD were followed up from 2002 to 2015. NAFLD was diagnosed by ultrasound after the exclusion of other possible causes of liver diseases. Baseline percent predicted forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) were categorized in quartiles. Adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) (using the highest quartile as reference) were calculated for incident NAFLD at follow-up, controlling for covariates and potential confounders.

RESULTS

During 579,714.5 person-years of follow-up, 24,450 participants developed NAFLD (incidence rate, 42.2 per 1,000 person-years). The mean follow-up period was 5.9±3.4 years. Regardless of smoking history, the risk for incident NAFLD increased with decreasing quartiles of FEV1 (%) and FVC (%) in a dose-response manner (p for trend<0.001). In never smokers, the aHRs (95% CIs) for incident NAFLD were 1.15 (1.08-1.21), 1.11 (1.05-1.18), and 1.08 (1.02-1.14) in quartiles 1-3 for FEV1 (%) and 1.12 (1.06-1.18), 1.11 (1.05-1.18), and 1.09 (1.03-1.15) in quartiles 1-3 for FVC (%), compared with the highest quartile reference. Similar inverse association was present in smoke-exposed subjects (aHR for incident NAFLD were 1.14, 1.21, 1.13 and 1.17, 1.11, 1.09 across FEV1(%) and FVC(%) quartile in increasing order, respectively).

CONCLUSIONS

Reduced lung function was a risk factor for incident NAFLD in a large middle-aged Korean cohort with over half a million person-years of follow-up.

Hepatocyte steatosis increases the expression of adhesion molecules in endothelial cells

Background: Non-alcoholic fatty liver disease is considered a hepatic manifestation of the metabolic syndrome. It is associated with endothelial dysfunction as an early event of generalized atherosclerosis. However, it is unclear whether steatotic hepatocytes influence endothelial function directly. Objective: Explore the influence of hepatocyte steatosis on the function of endothelial cells. Methods: Oleic and palmitic acid (2:1 mixture, final concentration: 1 mM for 24 hours) was used to induce a normal adult hepatocyte strain (L-02) for transformation into steatosis cells. This was followed by oil red O staining and transmission electron microscopy (TEM) for verification. The culture solution of steatotic L-02 cells was filtered and collected, and added into the culture substrate of human umbilical vein endothelial cells (HUVECs). The expression of vascular cellular adhesion molecule -1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin in HUVECs was detected by real-time polymerase chain reaction and Western blot assays. The apoptosis and proliferation of HUVECs was determined using flow cytometry. The experimental results were compared with the controls. Results: Oil red O staining and microscopic observation showed that the cytoplasm of induced L-02 cells contained a large amount of red lipid droplets. TEM results showed that the cytoplasm had lipid accumulation, swelling mitochondria, fewer cristae, and reduced number of rough endoplasmic reticula accompanied with degranulation. However, these changes were not observed in normal L-02 cells. As to the group of HUVECs treated by the filtrate of steatosis L-02 cells, the mRNA and protein expression of VCAM-1, ICAM-1, and E-selectin was higher than that in the control group. The difference was statistically significant (p <0.01). No significant difference was found when HUVECs apoptosis and proliferation were assessed by flow cytometry. Conclusion: Secretion from steatotic hepatocytes could boost the expression of VCAM-1, ICAM-1, and E-selectin in endothelial cells, indicating that hepatocyte steatosis could induce endothelial cell dysfunction. The proliferation and apoptosis of endothelial cells did not change, suggesting that hepatocyte steatosis had no influence on the viability of endothelial cells under this condition.

Randomized clinical trial: benefits of aerobic physical activity for 24 weeks in postmenopausal women with nonalcoholic fatty liver disease

OBJECTIVE

The aim of the study was to evaluate the effectiveness of aerobic physical activity in reducing the frequency of hepatic steatosis and metabolic and cardiovascular risk in postmenopausal women with nonalcoholic fatty liver disease (NAFLD).

METHODS

Forty sedentary postmenopausal women (mean age 55.3 ± 8.0 y) with biopsy-proven NAFLD were randomly divided into two groups: an exercising group (19 participants) and a control group (nonexercising, 21 participants). The exercise group underwent a supervised aerobic physical activity program of 120 min/wk for 24 weeks. The anthropometric parameters; body composition; hepatic, lipid, and glycemic profiles; homeostasis model assessment of insulin resistance index; cytokines; transient elastography (FibroScan; liver stiffness/controlled attenuation parameter); and cardiopulmonary exercise test were evaluated at baseline and after 24 weeks of protocol.

RESULTS

At baseline there were no significant differences in anthropometric, metabolic, and inflammatory parameters-stiffness and liver fat content by FibroScan between the groups. After 24 weeks, we observed a decrease of waist circumference, an increase of high-density lipoprotein cholesterol levels (P < 0.05), and improved cardiopulmonary functional capacity in the exercise group. In addition, the controlled attenuation parameter analysis showed no significant decrease of hepatic steatosis in the exercise group. With regard to the systemic inflammation, there were, however, no significant differences in the cytokines between the groups.

CONCLUSIONS

An aerobic physical activity program of 24 weeks in NAFLD postmenopausal women showed improvement in some variables such as waist circumference, high-density lipoprotein cholesterol, and cardiopulmonary performance that may be beneficial in improving cardiovascular risk factors in this population.

The Transcriptomic Signature Of Disease Development And Progression Of Nonalcoholic Fatty Liver Disease

A longitudinal molecular model of the development and progression of nonalcoholic fatty liver disease (NAFLD) over time is lacking. We have recently validated a high fat/sugar water-induced animal (an isogenic strain of C57BL/6 J:129S1/SvImJ mice) model of NAFLD that closely mimics most aspects of human disease. The hepatic transcriptome of such mice with fatty liver (8 weeks), steatohepatitis with early fibrosis (16–24 weeks) and advanced fibrosis (52 weeks) after initiation of the diet was evaluated and compared to mice on chow diet. Fatty liver development was associated with transcriptional activation of lipogenesis, FXR-RXR, PPAR-α mediated lipid oxidation and oxidative stress pathways. With progression to steatohepatitis, metabolic pathway activation persisted with additional activation of IL-1/inhibition of RXR, granulocyte diapedesis/adhesion, Fc macrophage activation, prothrombin activation and hepatic stellate cell activation. Progression to advanced fibrosis was associated with dampening of metabolic, oxidative stress and cell stress related pathway activation but with further Fc macrophage activation, cell death and turnover and activation of cancer-related networks. The molecular progression of NAFLD involves a metabolic perturbation which triggers subsequent cell stress and inflammation driving cell death and turnover. Over time, inflammation and fibrogenic pathways become dominant while in advanced disease an inflammatory-oncogenic profile dominates.

Elevated Neutrophil-to-Lymphocyte Ratio in Metabolic Syndrome Is Associated with Increased Risk of Colorectal Adenoma

BACKGROUND

Metabolic syndrome (MetS) is an important cardiovascular risk factor for insulin resistance and has been linked to colorectal adenoma via inflammation. The neutrophil-to-lymphocyte ratio (NLR) has been suggested as an important inflammatory marker. We initiated this investigation to determine the relationship between colorectal adenoma and NLR in patients with MetS.

METHODS

We examined participants who visited the Health Promotion Center at Kosin University Gospel Hospital, Busan, Korea. Subjects who underwent both colonoscopy and liver ultrasonography were included. Colorectal adenoma was defined as the presence of a colon polyp with a histologically adenomatous component. MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III definition for South Asians. Anthropometric measurements and biochemical tests of liver and metabolic function were assessed.

RESULTS

A total of 1007 subjects were included in the study sample. Their mean age was 48.3 ± 9.7 years and 262 (26.0%) subjects had MetS, while 439 (43.6%) subjects had pathologically proven colorectal adenoma. Subjects with MetS were older, more likely to be male, and had significantly higher prevalences of colorectal adenoma (49.2% vs. 41.6%, P = 0.032), nonalcoholic fatty liver disease (62.8% vs. 19.5%, P < 0.001), and higher NLR (2.0 ± 0.9 vs. 1.7 ± 0.7, P < 0.001) compared to those without MetS. High NLR (≥2.0) was an independent factor affecting the prevalence of colorectal adenoma [odds ratio (OR) 1.38, confidence interval (95% CI) 1.02-1.88, P = 0.040], especially in subjects with MetS (OR 1.91, 95% CI 1.12-3.28, P = 0.018).

CONCLUSION

High NLR was associated with increased colorectal adenomatous polyps, particularly in subjects with MetS. Screening colonoscopies for the prevention of colorectal adenoma may be warranted for patients with high NLR and MetS.

Dietary creatine supplementation lowers hepatic triacylglycerol by increasing lipoprotein secretion in rats fed high-fat diet

Recent studies have shown that dietary creatine supplementation can prevent lipid accumulation in the liver. Creatine is a small molecule that plays a large role in energy metabolism, but since the enzyme creatine kinase is not present in the liver, the classical role in energy metabolism does not hold in this tissue. Fat accumulation in the liver can lead to the development of nonalcoholic fatty liver disease (NAFLD), a progressive disease that is prevalent in humans. We have previously reported that creatine can directly influence lipid metabolism in cell culture to promote lipid secretion and oxidation. Our goal in the current study was to determine whether similar mechanisms that occur in cell culture were present in vivo. We also sought to determine whether dietary creatine supplementation could be effective in reversing steatosis. Sprague-Dawley rats were fed a high-fat diet or a high-fat diet supplemented with creatine for 5 weeks. We found that rats supplemented with creatine had significantly improved rates of lipoprotein secretion and alterations in mitochondrial function that were consistent with greater oxidative capacity. We also find that introducing creatine into a high-fat diet halted hepatic lipid accumulation in rats with fatty liver. Our results support our previous report that liver cells in culture with creatine secrete and oxidize more oleic acid, demonstrating that dietary creatine can effectively change hepatic lipid metabolism by increasing lipoprotein secretion and oxidation in vivo. Our data suggest that creatine might be an effective therapy for NAFLD.

Cinnamomum cassiaPrevents High-Fat Diet-Induced Obesity in Mice through the Increase of Muscle Energy

The cortex of Cinnamomum cassia Presl (Cinnamomi Cortex: CC) has commonly been used for weight control in traditional medicines, but without a scientific basis. Therefore, this study was undertaken to investigate the anti-obesity effect of CC extract in a high-fat diet (HFD)-induced obese mouse model and in C2C12 mouse skeletal muscle cells. Male C57BL/6 mice were fed a normal diet or a HFD for 16 consecutive weeks, and orally administered CC extract (100 or 300[Formula: see text]mg/kg) or metformin (250[Formula: see text]mg/kg; positive control) daily for 16 weeks. CC extract administration significantly decreased body weights, food intakes, and serum levels of glucose, insulin, total cholesterol and ALT levels, prevented oral glucose tolerance and insulin resistance, inhibited the protein expressions of MyHC and PGC1[Formula: see text] and the phosphorylation of AMPK, suppressed lipid accumulation in liver, decreased adipocyte size and increased muscle mass in obese mice. For this in vitro study, C2C12 myoblasts were differentiated into the myotubes for five days, and then treated with CC extract (0.1 or 0.2[Formula: see text]mg/ml) for 24[Formula: see text]h. CC extract significantly increased ATP levels by increasing the mRNA expressions of mitochondrial biogenesis-related factors, such as, PGC1[Formula: see text], NRF-1, and Tfam, and the phosphorylations of AMPK and ACC. Our results suggest CC extract controls weight gain in obese mice by inhibiting lipid accumulation and increasing energy expenditure, and that its action mechanism involves the up-regulation of mitochondrial biogenesis in skeletal muscle cells.

High prevalence of apolipoprotein B dyslipoproteinemias in non-alcoholic fatty liver disease: The lifelines cohort study

OBJECTIVE

Cardiovascular disease (CVD) is a major adverse consequence of non-alcoholic fatty liver disease (NAFLD). The association of NAFLD with various apolipoprotein B (apoB) dyslipoproteinemias is unclear. We determined the prevalence of specific apoB dyslipoproteinemias in subjects with suspected NAFLD.

METHODS

This study was conducted among 22,865 fasting adults living in the northern part of the Netherlands (Lifelines Cohort Study). Six apoB dyslipoproteinemias were defined using an algorithm derived from apoB, total cholesterol and triglycerides. NAFLD was defined as Fatty Liver Index (FLI) ≥60. Advanced hepatic fibrosis was defined as NAFLD fibrosis score (NFS) ≥0.676.

RESULTS

4790 participants (20.9%) had an FLI≥60. NAFLD subjects were older, more likely to be men, more obese and more often had diabetes and metabolic syndrome (P<0.001 for each). Among NAFLD subjects, any apoB dyslipoproteinemia was present in 61.5% vs. 16.5% in subjects without NAFLD (P<0.001). Elevated chylomicrons were not observed in NAFLD. In univariate analysis, NAFLD was associated with a higher prevalence of each apoB dyslipoproteinemia vs. subjects with an FLI<60 (P<0.001), except for low density lipoprotein (LDL) dyslipoproteinemia. Additionally, each apoB dyslipoproteinemia was independently associated with NAFLD in age- and sex-adjusted logistic regression analysis, including the apoB dyslipoproteinemias together (P<0.001). The prevalence of apoB dyslipoproteinemias was not altered in subjects with NFS ≥0.676.

CONCLUSIONS

NAFLD rather than advanced hepatic fibrosis is independently associated with increased prevalence of chylomicrons+very low-density lipoproteins (VLDL) remnants, VLDL, LDL and VLDL+LDL dyslipoproteinemias. ApoB dyslipoproteinemias may contribute to increased CVD risk associated with NAFLD.

The regulatory effects of fish oil and chitosan on hepatic lipogenic signals in high-fat diet-induced obese rats

The present study investigated the regulatory effects of fish oil and chitosan on the signals of hepatic lipid metabolism and the postulated mechanism in high-fat diet-induced obese rats. Diet supplementation of chitosan and fish oil efficiently suppressed the increased weights in body and livers of high-fat diet-fed rats. Supplementation of chitosan and fish oil significantly decreased the activities of hepatic lipid biosynthesis-related enzymes and efficiently regulated plasma lipoprotein homeostasis. Both chitosan and fish oil significantly ameliorated the alterations in the protein expressions of hepatic lipogenic transcription factors (LXRα and PPARα), and could also significantly regulate the downstream hepatic lipogenic genes (FAS, HMGCR, CYP7A1, FATP, FABP, AOX, and ABCA) expressions in high-fat diet-fed rats. These results suggest that both fish oil and chitosan exerts downregulative effects on hepatic lipid metabolism in high-fat diet-induced obese rats via the LXRα inhibition and PPARα activation, which further affect the expressions of hepatic lipogenesis-associated genes.

IL-17 Axis Driven Inflammation in Non-Alcoholic Fatty Liver Disease Progression

Obesity is a primary risk factor for the development of non-alcoholic fatty liver disease (NAFLD). NAFLD, the most common chronic liver disease in the world, represents a spectrum of disorders that range from steatosis (NAFL) to steatohepatitis (NASH) to cirrhosis. It is anticipated that NAFLD will soon surpass chronic hepatitis C infection as the leading cause for needing liver transplantation. Despite its clinical and public health significance no specific therapies are available. Although the etiology of NAFLD is multifactorial and remains largely enigmatic, it is well accepted that inflammation is a central component of NAFLD pathogenesis. Despite the significance, critical immune mediators, loci of immune activation, the immune signaling pathways and the mechanism(s) underlying disease progression remain incompletely understood. Recent findings have focused on the role of Interleukin 17 (IL-17) family of proinflammatory cytokines in obesity and pathogenesis of obesity-associated sequelae. Notably, obesity favors a Th17 bias and is associated with increased IL-17A expression in both humans and mice. Further, in mice, IL-17 axis has been implicated in regulation of both obesity and NAFLD pathogenesis. However, despite these recent advances several important questions require further evaluation including: the relevant cellular source of IL-17A production; the critical IL- 17RA-expressing cell type; the critical liver infiltrating immune cells; and the underlying cellular effector mechanisms. Addressing these questions may aid in the identification and development of novel therapeutic targets for prevention of inflammation- driven NAFLD progression.

The effect of enriched chicory inulin on liver enzymes, calcium homeostasis and hematological parameters in patients with type 2 diabetes mellitus: A randomized placebo-controlled trial

BACKGROUNDS AND AIMS

Type 2 diabetic mellitus (T2DM) as one of the main causes of morbidity and mortality is associated with immune system disturbances and metabolic abnormalities. In the current study we aimed to evaluate the effects of enriched chicory inulin supplementation on liver enzymes, serum calcium and phosphorous concentrations and hematological parameters in patients with T2DM.

METHODS

Forty-six diabetic females patients were randomly allocated into intervention (n=27) and control (n=22) groups. Subjects in the intervention group received a daily dose of 10g of chicory and subjects in control group received a placebo for two months. Anthropometric variables, glucose homeostasis, hematological parameters and metabolic indices including serum alanine aminotransfersae (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), calcium and phosphorous as well as creatinine concentrations, glomerular filtration rate (GFR) and blood pressure were assessed at the beginning and end of the trial.

RESULTS

Significant reductions in fasting serum glucose (FSG), Hb A1C, AST and ALP concentrations were observed in chicory-treated group. Systolic and diastolic blood pressures were also reduced in chicory-treated group. Serum calcium significantly increased after chicory supplementation but no change in placebo treated group has been occurred (P=0.014). Supplementation with enriched chicory for two months significantly reduced hematocrit and mean corpuscular volume (MCV) values (P<0.05). Changes in serum insulin, creatinine and GFR were not significant.

CONCLUSION

The present study showed beneficial effects of oligofructose-enriched chicory on the improvement of the glucose and calcium homeostasis, liver function tests, blood pressure and reduction in hematologic risk factors of diabetes in female patients with T2DM. Further studies in both genders are needed to generalize these findings to total population.

Altered cellular redox status, sirtuin abundance and clock gene expression in a mouse model of developmentally primed NASH

Background

We have previously shown that high fat (HF) feeding during pregnancy primes the development of non-alcoholic steatohepatits (NASH) in the adult offspring. However, the underlying mechanisms are unclear.

Aims

Since the endogenous molecular clock can regulate hepatic lipid metabolism, we investigated whether exposure to a HF diet during development could alter hepatic clock gene expression and contribute to NASH onset in later life.

Methods

Female mice were fed either a control (C, 7% kcal fat) or HF (45% kcal fat) diet. Offspring were fed either a C or HF diet resulting in four offspring groups: C/C, C/HF, HF/C and HF/HF. NAFLD progression, cellular redox status, sirtuin expression (Sirt1, Sirt3), and the expression of core clock genes (Clock, Bmal1, Per2, Cry2) and clock-controlled genes involved in lipid metabolism (Rev-Erbα, Rev-Erbβ, RORα, and Srebp1c) were measured in offspring livers.

Results

Offspring fed a HF diet developed NAFLD. However HF fed offspring of mothers fed a HF diet developed NASH, coupled with significantly reduced NAD⁺/NADH (p < 0.05, HF/HF vs C/C), Sirt1 (p < 0.001, HF/HF vs C/C), Sirt3 (p < 0.01, HF/HF vs C/C), perturbed clock gene expression, and elevated expression of genes involved lipid metabolism, such as Srebp1c (p < 0.05, C/HF and HF/HF vs C/C).

Conclusion

Our results suggest that exposure to excess dietary fat during early and post-natal life increases the susceptibility to develop NASH in adulthood, involving altered cellular redox status, reduced sirtuin abundance, and desynchronized clock gene expression.

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Offspring of mothers fed a high fat diet show severe fatty liver in later life.

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HF feeding is associated with altered cellular redox status and reduced sirtuin gene expression.

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HF feeding desynchronises the expression of core clock genes and lipogenic transcription factors.

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Exposure to a HF diet during development causes changes in liver metabolism that precede severe fatty liver disease.

Relationship between non-alcoholic fatty liver disease and inflammation in patients with non-alcoholic fatty liver

Background:

Non-alcoholic fatty liver is the most chronic liver disease that eventually can become cirrhosis. One of the underlying assumptions for the fatty liver created by inflammation of the hepatocytes. We aimed to assess the association between non-alcoholic fatty liver disease (NAFLD) and sub-clinical inflammation.

Materials and Methods:

This is a cross-sectional study which was conducted on 55 patients over 30 years, with NAFLD. Fatty liver grade was assessed using liver ultrasound. Liver enzymes (alanine aminotransferase, aspartate aminotransferase), anthropometric characteristics and inflammatory marker C-reactive protein (CRP) were measured. Qualitative variables (sex and fatty liver grade) and quantitative variables such as were compared with independent t-test and Chi-square test. Relationship between fatty liver grade and inflammatory index was assessed with SPSS software (version 20; SPSS, Inc. Chicago, IL, USA).

Results:

Non-alcoholic fatty liver grades were associated with CRP level and this relationship remains in statistically significant level even after adjusting the effects of confounding variables such as age, sex and body mass index of participants (P = 0.016).

Conclusion:

In this cross-sectional study, presentation of NAFLD showed a significant correlation with sub-clinical systemic inflammation and CRP level.

The CBS/CSE system: a potential therapeutic target in NAFLD?

Non-alcoholic fatty liver disease (NAFLD) is a broad spectrum liver disorder diagnosed in patients without a history of alcohol abuse. NAFLD is growing at alarming rates worldwide. Its pathogenesis is complex and incompletely understood. The cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) system regulates homocysteine and cysteine metabolism and contributes to endogenous hydrogen sulfide (H2S) biosynthesis. This review summarizes our current understanding of the hepatic CBS/CSE system, and for the first time, positions this system as a potential therapeutic target in NAFLD. As will be discussed, the CBS/CSE system is highly expressed and active in the liver. Its dysregulation, presenting as alterations in circulating homocysteine and (or) H2S levels, has been reported in NAFLD patients and in NAFLD-associated co-morbidities such as obesity and type 2 diabetes. Intricate links between the CBS/CSE system and a number of metabolic and stress related molecular mediators have also emerged. Various dysfunctions in the hepatic CBS/CSE system have been reported in animal models representative of each NAFLD spectrum. It is anticipated that a newfound appreciation for the hepatic CBS/CSE system will emerge that will improve our understanding of NAFLD pathogenesis, and give rise to new prospective targets for management of this disorder.

Myeloperoxidase-Hepatocyte-Stellate Cell Cross Talk Promotes Hepatocyte Injury and Fibrosis in Experimental Nonalcoholic Steatohepatitis

AIMS

Myeloperoxidase (MPO), a highly oxidative enzyme secreted by leukocytes has been implicated in human and experimental nonalcoholic steatohepatitis (NASH), but the underlying mechanisms remain unknown. In this study, we investigated how MPO contributes to progression from steatosis to NASH.

RESULTS

In C57Bl/6J mice fed a diet deficient in methionine and choline to induce NASH, neutrophils and to a lesser extent inflammatory monocytes are markedly increased compared with sham mice and secrete abundant amounts of MPO. Through generation of HOCl, MPO directly causes hepatocyte death in vivo. In vitro experiments demonstrate mitochondrial permeability transition pore induction via activation of SAPK/JNK and PARP. MPO also contributes to activation of hepatic stellate cells (HSCs), the most important source of collagen in the liver. In vitro MPO-activated HSCs have an activation signature (MAPK and PI3K-AKT phosphorylation) and upregulate COL1A1, α-SMA, and CXCL1. MPO-derived oxidative stress also activates transforming growth factor β (TGF-β) in vitro, and TGF-β signaling inhibition with SB-431542 decreased steatosis and fibrosis in vivo. Conversely, congenital absence of MPO results in reduced hepatocyte injury, decreased levels of TGF-β, fewer activated HSCs, and less severe fibrosis in vivo.

INNOVATION AND CONCLUSION

Cumulatively, these findings demonstrate important cross talk between inflammatory myeloid cells, hepatocytes, and HSCs via MPO and establish MPO as part of a proapoptotic and profibrotic pathway of progression in NASH, as well as a potential therapeutic target to ameliorate this disease.

Glucose fluctuation increased hepatocyte apoptosis under lipotoxicity and the involvement of mitochondrial permeability transition opening

Oxidative stress is considered to be an important factor in producing lethal hepatocyte injury associated with nonalcoholic fatty liver disease (NAFLD). Glucose fluctuation, more pronounced in patients with diabetes, has been recognized as an even stronger oxidative stress inducer than the sustained hyperglycemia. Here, we investigated the role of glucose variability in the development of the NAFLD based on hepatocyte apoptosis and possible mechanisms. To achieve this goal we studied C57BL/6J mice that were maintained on a high fat diet (HFD) and injected with glucose (3 g/kg) twice daily to induce intermittent high glucose (IHG). We also studied hepatic L02 cells incubated with palmitic acid (PA) to induce steatosis. The following experimental groups were compared: normal glucose (NG), sustained high glucose (SHG) and IHG with or without PA. We found that, although hepatic enzyme levels and liver lipid deposition were comparable between HFD mice injected with glucose or saline, the glucose injected mice displayed marked hepatocyte apoptosis and inflammation, accompanied by increased lipid peroxide in liver. In vitro, in the presence of PA, IHG increased L02 cell apoptosis and oxidative stress and produced pronounced mitochondrial dysfunction relative to the NG and SHG groups. Furthermore, treatment with the mitochondrial permeability transition (MPT) inhibitor, cyclosporin A (1.5 μmol/l), prevented mitochondrial dysfunction, oxidative stress and hepatocyte apoptosis. Our data suggests that IHG under lipotoxicity might contribute to the development of NAFLD by increasing oxidative stress and hepatocyte apoptosis via MPT and its related mitochondrial dysfunction.

Tyrosol Attenuates High Fat Diet-Induced Hepatic Oxidative Stress: Potential Involvement of Cystathionine β-Synthase and Cystathionine γ-Lyase

The Mediterranean diet is known for its cardioprotective effects. Recently, its protective qualities have also been reported in patients with non-alcoholic fatty liver disease (NAFLD). Oxidative stress is one of the important factors responsible for the development and progression of NAFLD. Hydrogen sulfide (H2S), a multifaceted gasotransmitter, has emerged as a potential therapeutic target in NAFLD. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are major enzymes responsible for endogenous H2S synthesis. Since oxidative stress contributes to NAFLD pathogenesis, the objective of this study was to investigate the effect of tyrosol, a major compound in olive oil and white wine, on high fat diet-induced hepatic oxidative stress and the mechanisms involved. Mice (C57BL/6) were fed for 5 weeks with a control diet (10 % kcal fat), a high fat diet (60 % kcal fat, HFD) or a HFD supplemented with tyrosol. High fat diet feeding induced hepatic oxidative stress, as indicated by the significant increase in lipid peroxidation and NADPH oxidase activity. Tyrosol supplementation significantly increased hepatic CBS and CSE expression and H2S synthesis in high fat diet-fed mice. Such effects were associated with the attenuation of high fat diet-induced hepatic lipid peroxidation and the restoration of the redox equilibrium of the antioxidant glutathione. Tyrosol also inhibited palmitic acid-induced oxidative stress in hepatocytes (HepG2 cells). These results suggest that the antioxidant properties of tyrosol may be mediated through functional changes in CBS and CSE activity, which might contribute to the hepatoprotective effect of the Mediterranean diet.

Fructose Mediated Non-Alcoholic Fatty Liver Is Attenuated by HO-1-SIRT1 Module in Murine Hepatocytes and Mice Fed a High Fructose Diet

Background

Oxidative stress underlies the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), obesity and cardiovascular disease (CVD). Heme Oxygenase-1 (HO-1) is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. Sirtuin1 (SIRT1) belongs to the family of NAD-dependent de-acyetylases and is modulated by cellular redox.

Hypothesis

We hypothesize that fructose-induced obesity creates an inflammatory and oxidative environment conducive to the development of NAFLD and metabolic syndrome. The aim of this study is to determine whether HO-1 acts through SIRT1 to form a functional module within hepatocytes to attenuate steatohepatitis, hepatic fibrosis and cardiovascular dysfunction.

Methods and Results

We examined the effect of fructose, on hepatocyte lipid accumulation and fibrosis in murine hepatocytes and in mice fed a high fructose diet in the presence and absence of CoPP, an inducer of HO-1, and SnMP, an inhibitor of HO activity. Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05). Further fructose supplementation increased FAS, PPARα, pAMPK and triglycerides levels; CoPP negated this increase. Concurrent treatment with CoPP and SIRT1 siRNA in hepatocytes increased FAS, PPARα, pAMPK and triglycerides levels suggesting that HO-1 is upstream of SIRT1 and suppression of SIRT1 attenuates the beneficial effects of HO-1. A high fructose diet increased insulin resistance, blood pressure, markers of oxidative stress and lipogenesis along with fibrotic markers in mice (p<0.05). Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose). These beneficial effects of CoPP were reversed by SnMP.

Conclusion

Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates NAFLD-associated vascular dysfunction; effects that are mediated by activation of SIRT1 gene expression.

New role of irisin in hepatocytes: The protective effect of hepatic steatosis in vitro

Irisin is a newly identified myokine related to exercise and the browning of white fat. Recently, it was reported that irisin serum levels are associated with intrahepatic triglyceride content, suggesting that it might have an important role in the liver. The aim of this study was to determine the role of irisin in hepatocytes. Specifically, the effect of recombinant irisin on palmitic acid (PA)-induced lipogenesis and its related signal pathways were examined in AML12 cells and mouse primary hepatocytes. In the present study, we observed the presence of irisin inside the cells in response to the treatment of recombinant irisin by flow cytometry and cell imaging technique. Recombinant irisin significantly inhibited the PA-induced increase in lipogenic markers ACC and FAS at the mRNA and protein levels, and prevented the PA-induced lipid accumulation in hepatocytes. Additionally, irisin inhibited the PA-induced increase in the expression, nuclear localization, and transcriptional activities of the master regulators of lipogenesis (LXRα and SREBP-1c). Moreover, irisin attenuated PA-induced oxidative stress, which was confirmed by measuring the expression of inflammatory markers (NFκB, COX-2, p38 MAPK, TNF, IL-6) and superoxide indicator (dihydroethidium). The preventive effects of irisin against lipogenesis and oxidative stress were mediated by the inhibition of protein arginine methyltransferase-3 (PRMT3). These findings suggested that irisin might have a beneficial role in the prevention of hepatic steatosis by altering the expression of lipogenic genes and attenuating oxidative stress in a PRMT3 dependent manner.

Nonalcoholic fatty liver disease is an independent risk factor for atherosclerosis in young adult men

INTRODUCTION

The possible cause of accelerated atherosclerosis in NAFLD may be the relationship with the MetS and its components. Our primary goal was to evaluate the relationship between NAFLD and subclinical atherosclerosis in adult male patients between 20 and 40 years of age. Moreover, we aimed to investigate the changes in this association according to the presence or absence of MetS.

METHOD

Sixty-one male patients with biopsy-proven NAFLD and 41 healthy male volunteers were enrolled. In order to exclude any interference of confounding factors, we studied a specifically selected group with no additional cardiovascular risk. PWV, CIMT and FMD levels were measured in all patients and controls.

RESULTS

The levels of cf-PWV were significantly higher in SS and NASH patients compared to the control group (P < 0.001); no significant difference was found between SS and NASH patients (P > 0.05). We found significantly decreased FMD levels in patients with SS and NASH compared with control subjects (P < 0.001). Subjects with NASH had significantly greater CIMT measurements than the SS and controls (P = 0.026, P < 0.001, respectively). Although, NAFLD patients with MetS had increased cf-PWV and CIMT and reduced FMD compared to healthy subjects (P < 0.05), no significant difference existed between NAFLD with Mets and NAFLD without MetS in terms of cf-PWV, CIMT and FMD (P > 0.05) CONCLUSION: The present study showed that the presence of NAFLD leads to increased risk of endothelial dysfunction and atherosclerosis in adult male patients, independent of MetS.

Nonalcoholic fatty liver disease as a potential risk factor of cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic component of the metabolic syndrome. The aim of this review is to summarize the available data linking NAFLD with cardiovascular disease (CVD). The following topics are reviewed: (a) the clinical evidence linking NAFLD to increased prevalence of CVD; (b) the relationship between NAFLD (which is diagnosed by liver biopsy, serum liver enzymes, or ultrasonography) and incidence of CVD; (c) the mechanism linking NAFLD to CVD and clinical implication; and (d) the potential impact of NAFLD treatment on cardiac complications. CVD dictates the outcome (or outcomes) in patients with NAFLD more frequently and to a greater extent than does the progression of liver disease. NAFLD patients have a higher risk of all-cause death than the general population, mainly because of CVD or liver-related causes. The biologic mechanism linking NAFLD and CVD might be associated with various factors, involving a complex interaction among insulin resistance, oxidative stress, abnormal adipocytokine profile, endothelial dysfunction, lipid abnormalities, and activation of inflammatory cascade. Lifestyle modifications and pharmacotherapy are helpful to treat patients with NAFLD. NAFLD is likely to be associated with an increased risk of CVD, and raises the possibility that NAFLD may not only be a marker but also an early mediator of CVD.

Non-alcoholic fatty liver disease is associated with progression of arterial stiffness

BACKGROUND AND AIMS

NAFLD is an independent risk factor for increased cardiovascular disease. Arterial stiffness is an index of subclinical atherosclerosis. The aims of this study were to examine prospectively the relationship between Non-alcoholic fatty liver disease (NAFLD) and the progression of arterial stiffness.

METHODS AND RESULTS

A prospective study of 728 men and 497 women free of hypertension, and diabetes at the baseline were conducted. The subjects were followed for 5 years. The progression rate of arterial stiffness was measured by calculating the increase in brachial-ankle pulse wave velocity (baPWV) the changes of the baPWV (adjusted for age) during the study period was significantly greater in the patients with NAFLD (172.4 ± 42.1 cm/s for men, 95.8 ± 36.7 cm/s for women) than in the subjects without NAFLD (70.3 ± 56.5 cm/s for men, 55.4 ± 42.2 cm/s for women). For the subjects with metabolic syndrome, after adjusting for multiple risk factors, NAFLD was a significant predictor of baPWV progression (for male, β = 0.843; P < 0.001; for female, β = 0.575; P < 0.001, respectively). In addition, results were unmodified in subjects without metabolic syndrome.

CONCLUSIONS

NAFLD was found to be an independent predictor of faster progression of baPWV even after adjusting other cardiovascular risk factors. These prospective data support a pathogenic role for NAFLD in the development of arterial stiffness.

Nonalcoholic fatty liver disease progression in rats is accelerated by splenic regulation of liver PTEN/AKT

BACKGROUND/AIM

The spleen has been reported to participate in the development of nonalcoholic fatty liver disease (NAFLD), but the mechanism has not been fully characterized. This study aims to elucidate how the spleen affects the development of NAFLD in a rat model.

MATERIALS AND METHODS

Following either splenectomy or sham operation, male Sprague-Dawley (SD) rats were fed a high-fat diet to drive the development of NAFLD; animals fed a normal diet were used as controls. Two months after surgery, livers and blood samples were collected. Serum lipids were measured; liver histology, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) gene expression, and the ratio of pAkt/Akt were determined.

RESULTS

Splenectomy increased serum lipids, except triglyceride (TG) and high-density lipoprotein (HDL), in animals fed either a high-fat or normal diet. Furthermore, splenectomy significantly accelerated hepatic steatosis. Western blot analysis and real-time polymerase chain reaction showed splenectomy induced significant downregulation of PTEN expression and a high ratio of pAkt/Akt in the livers.

CONCLUSIONS

The spleen appears to play a role in the development of NAFLD, via a mechanism involving downregulation of hepatic PTEN expression.