Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases in children and adolescents. NAFLD ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis (NASH), wherein hepatocellular inflammation and/or fibrosis coexist with steatosis. Circulating microRNA (miRNA) levels have been suggested to be altered in NAFLD, but the extent to which miRNA are related to NAFLD features remains unknown. This analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in adolescents.

AIM

To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with NAFLD.

METHODS

This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of Bariatric Surgery study. Intra-operative core liver biopsies were collected from participants and used to characterize histological features of NAFLD. Plasma samples were collected during surgery for miRNA profiling. A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq platform. We examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age, sex, race, and other key covariates. Ingenuity Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of NAFLD.

RESULTS

We identified 16 upregulated plasma miRNAs, including miR-193a-5p and miR-193b-5p, and 22 downregulated plasma miRNAs, including miR-1282 and miR-6734-5p, in adolescents with NAFLD. Moreover, 52, 16, 15, and 9 plasma miRNAs were associated with NASH, fibrosis, ballooning degeneration, and lobular inflammation, respectively. Collectively, 16 miRNAs were associated with two or more histological features of NAFLD. Among those miRNAs, miR-411-5p was downregulated in NASH, ballooning, and fibrosis, while miR-122-5p, miR-1343-5p, miR-193a-5p, miR-193b-5p, and miR-7845-5p were consistently and positively associated with all histological features of NAFLD. Pathway analysis revealed that most common pathways of miRNAs associated with multiple NAFLD features have been associated with tumor progression, while we also identified linkages between miR-122-5p and hepatitis C virus and between miR-199b-5p and chronic hepatitis B.

CONCLUSION

Plasma miRNAs were associated with NAFLD features in adolescent with severe obesity. Larger studies with more heterogeneous NAFLD phenotypes are needed to evaluate miRNAs as potential biomarkers of NAFLD.

Yohimbine ameliorates liver inflammation and fibrosis by regulating oxidative stress and Wnt/β-catenin pathway

BACKGROUND AND PURPOSE

Chronic liver injury, caused by various aetiologies, causes recurrent tissue damage, culminating in decreased liver regenerative ability and resulting in fibrosis followed by cirrhosis. In this study, the anti-fibrotic activity of Yohimbine hydrochloride (YHC) was investigated using various in vitro models and in vivo models.

METHODS

To assess the anti-inflammatory, antioxidant, and anti-fibrotic effects of YHC, lipopolysaccharide or TGF-β induced differentiation or lipid-induced oxidative-stress models were employed using HLECs, HSC-LX2, and HepG2 cells. Further, thioacetamide (TAA) induced hepatic inflammation/fibrosis models were utilized to validate the YHC's anti-fibrotic activity in rats.

RESULTS

Inflammation/differentiation experiments in HLECs and HSC-LX2 revealed that YHC treatment significantly (p < 0.001) mitigated the lipopolysaccharide or TGF-β induced upregulation of inflammatory and fibrotic markers expression respectively. In addition, YHC dose-dependently reduced the TGF-β induced migration and palmitic acid-induced oxidative stress in HepG2 cells. Further, TAA administration (5 weeks) in vivo rat model showed increased inflammatory marker levels/expression, oxidative stress, and pathological abnormalities. Additionally, TAA administration (9 weeks) elevated the fibrotic marker expression, collagen deposition in liver tissues, and shortened longevity in rats. Treatment with YHC dose-dependently mitigated the TAA-induced abnormalities in both inflammation and fibrosis models and improved the survival of the rats. Further mechanistic approaches revealed that TAA administration elevated the JNK, Wnt components and β-catenin expression in hepatic stellate cells and animal tissues. Further treatment with YHC significantly modulated the JNK/Wnt/β-catenin signaling. Moreover, the β-catenin nuclear translocation results showed that β-catenin levels were significantly elevated in the nuclear fraction of TAA control samples and reduced in YHC-treated samples.

CONCLUSION

Yohimbine treatment significantly improved inflammation and fibrosis by inhibiting differentiation, oxidative stress, and collagen deposition by partly modulating the JNK/Wnt/β-catenin pathway. These results might serve as a foundation for proposing yohimbine as a potential lead compound for liver fibrosis.

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.

Differences in autoimmune hepatitis based on inflammation localization

Histopathology is essential for the diagnosis and evaluation of disease activity of autoimmune hepatitis (AIH). We aimed to elucidate the characteristics of AIH from the localization of inflammation. We re-evaluated a nationwide survey that was performed in Japan in 2018 of AIH patients diagnosed between 2014 and 2017. A total of 303 patients were enrolled, and the clinical and treatment characteristics were compared between the patients with predominantly portal inflammation (230 patients) or lobular inflammation (73 patients). AIH patients with lobular inflammation had a higher probability of being diagnosed with acute hepatitis than those with portal inflammation. Liver enzyme levels were higher in patients with lobular inflammation, whereas immunoglobulin G levels were higher in patients with portal inflammation. The prevalence of an alanine aminotransferase level < 30 U/L after 6 months of treatment was significantly higher in patients with lobular inflammation than in those with portal inflammation (81.7% vs. 67.3%, P = 0.046). The localization of inflammation may be useful for evaluating the onset of AIH.

The Correlation between Serum Zinc Level and Liver Histology in Non-Alcoholic Steatohepatitis

Background & Objective

The aim of this present study was to assess the relationship between serum zinc levels and liver histopathological findings in non-alcoholic steatohepatitis (NASH) patients.

Methods

This case-control study was performed in consecutively selected NASH patients who had been referred to a general hospital. The control group consisted of age and sex-matched individuals with normal physical examinations, laboratory findings, and liver ultrasounds. Serum zinc level was measured using atomic absorption spectrophotometry. Liver histopathological findings were determined based on non-alcoholic fatty liver activity score.

Results

A cohort of eighty biopsy-proven NASH patients and eighty controls were enrolled in the study. The mean serum zinc level was significantly lower in the NASH group compared with the controls. The mean serum zinc concen- tration was significantly lower in moderate and severe lobular inflammation groups than the mild group. After multiple adjustments for potential contributing variables, serum zinc level was associated with the severity of lobular inflam- mation. Nonetheless, it was not associated with liver steatosis and fibrosis. A serum zinc value of 89 (µg/dl) yielded a sensitivity and specificity of 93% and 86%, respectively, characterizing patients with lobular inflammation of less than two inflammatory foci per high-power field (HPF) from more advanced groups. Furthermore, a value of 79.55 (µg/dl) yielded a sensitivity and specificity of 87% and 100%, respectively, distinguishing those with a lobular inflammation grade of less than four foci per HPF from more advanced cases.

Conclusion

Serum zinc level might be associated with the severity of lobular inflammation in NASH.

Acidophil bodies in nonalcoholic steatohepatitis

The significance of the quantity of acidophil bodies (AB) in nonalcoholic steatohepatitis (NASH) is not certain. We quantified AB in liver biopsies and examined the association with the diagnosis of NASH and other histologic features. We reviewed 157 liver biopsies from the NASH Clinical Research Network Database collected in 2006. One hundred twenty-seven biopsies were from adult patients. Diagnoses were 94 definite NASH, 40 borderline NASH, and 23 definitely not NASH. The total length and average width of the core biopsies were measured, and the biopsy areas were calculated (mm(2)). Total AB were counted, and mean AB count per mm(2) was calculated (AB/mm(2)) to derive acidophil body index (ABI). ABI was 0.04 (±0.08) in definite NASH and 0.02 (±0.05) in borderline/definitely not NASH groups combined (P = .02) in all 157 biopsies; similar findings were present in the 127 adult-only biopsies (0.04 ± 0.05 and 0.02 ± 0.05, respectively; P = .05). In all 157 biopsies, increased ABI was associated with greater lobular inflammation (P = .01) and many ballooned hepatocytes (P = .048). There was a positive relationship between ABI and high nonalcoholic fatty liver disease activity scores, but this association was not statistically significant. There was no association between ABI and steatosis or fibrosis stage either in the entire cohorts or in the subset of adult patients. In conclusion, the density of AB is associated with lobular inflammation, ballooned hepatocytes, and the diagnosis of NASH in adult and pediatric liver biopsies, suggesting the implication of the apoptotic pathway in NASH-associated liver cell injury.

Management of non-alcoholic fatty liver disease in 2015

There is no single pharmacologic therapy that has been approved to treat nonalcoholic fatty liver disease in the general population. The backbone of therapy currently includes intensive lifestyle modification with established targets for diet and weight loss. The use of unsweetened, unfiltered coffee along with limiting high fructose corn syrup have emerged as beneficial dietary recommendations. The use of empiric oral hypoglycemic agents and vitamin E, however, has not been widely accepted. Developing bariatric surgical techniques are promising, but additional studies with long-term follow up are needed before it can be widely recommended. Finally, liver transplantation is an increasingly frequent consideration once complications of end-stage disease have developed. The future treatment of those with nonalcoholic fatty liver disease will likely involve a personalized approach. The importance of the gut microbiome in mediating hepatocyte inflammation and intestinal permeability is emerging and may offer avenues for novel treatment. The study of anti-fibrotic agents such as pentoxifylline and FXR agonists hold promise and new pathways, such as hepatocyte cannabinoid receptor antagonists are being studied. With the incidence of obesity and the metabolic syndrome increasing throughout the developed world, the future will continue to focus on finding novel agents and new applications of existing therapies to help prevent and to mediate the progression of nonalcoholic fatty liver disease.