Fatty Liver Disease: A Practical Approach

Effect of Kinins on the Hepatic Oxidative Stress in Mice Treated with a Methionine-Choline Deficient Diet

Non-alcoholic fatty liver is the leading cause of hepatic disease worldwide and ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) due to cell injury, oxidative stress, and apoptosis. The kinins' role in the liver has been studied in experimental fibrosis, partial hepatectomy, and ischemia-reperfusion and is related to cell death and regeneration. We investigated its role in experimental NASH induced by a methionine-choline deficient diet for 4 weeks. After that, liver perfusion was performed, and bradykinin (BK) or des-Arg9-BK was infused. Cell death was evaluated by cathepsin-B and caspase-3 activity and oxidative stress by catalase (CAT), glutathione S-transferase, and superoxide dismutase (SOD) activities, as well as malondialdehyde and carbonylated proteins. In control livers, DABK increased CAT activity, which was reversed by antagonist DALBK. In the NASH group, kinins tend to decrease antioxidant activity, with SOD activity being significantly reduced by BK and DABK. Malondialdehyde levels increased in all NASH groups, but carbonylated protein did not. DABK significantly decreased cathepsin-B in the NASH group, while caspase-3 was increased by BK in control animals. Our results suggest that B1R and/or B2R activation did not induce oxidative stress but affected the antioxidant system, reducing SOD in the NASH group.

Clinicopathological Features of Hepatocellular Carcinoma with Metabolic Risk Factors

Objective

This study aims to explore the pathological characteristics of metabolic-related hepatocellular carcinoma (HCC) and its correlation with metabolic factors.

Methods

Fifty-one patients with liver cancer of unknown causes were enrolled. Biopsy of the liver and staining of the liver tissues with hematoxylin-eosin as well as special and immunohistochemical stains were performed. The histological subtypes of HCC were diagnosed based on the WHO Classification of Malignant Hepatocellular Tumors. The NAFLD activity score system was adopted for assessing the surrounding non-neoplastic liver tissues.

Results

Of the total, 42 (82.4%) patients were diagnosed with HCC, 32 had metabolic risk factors, 20 patients met the diagnostic criteria of the metabolic-associated fatty liver disease (MAFLD)-related HCC, and 40.6% (13/32) had liver cirrhosis. The incidence of cirrhosis (p = 0.033) and diabetes mellitus type 2 (p = 0.036) in patients with MAFLD-related HCC was notably higher than that in HCC patients with only metabolic risk factors. Among the 32 HCC cases with metabolic risk factors, trabecular type was the most prevalent, followed by steatohepatitis type, scirrhous type, solid type, pseudoglandular type, clear-cell type, and macrotrabecular type. The degree of tumor cells' swelling and ballooning was found to be positively related to the degree of fibrosis in the surrounding liver tissues (p = 0.011) as well as the proportion of cirrhosis (p = 0.004). Moreover, the degree of fibrosis in the surrounding liver tissues showed a negative correlation with the levels of serum cholesterol (p = 0.002), low-density lipoprotein (p = 0.002), ApoA1 (p = 0.009), ApoB (p = 0.022), total protein (p = 0.015), WBC count (p = 0.006), and PLT count (p = 0.015).

Conclusion

Pathological characteristics of the tumor and adjacent non-neoplastic liver tissues of HCC with metabolic risk factors were found to be correlated with metabolic abnormalities.

Neonatal Orally Administered Zingerone Attenuates Alcohol-Induced Fatty Liver Disease in Experimental Rat Models

Alcohol intake at different developmental stages can lead to the development of alcohol-induced fatty liver disease (AFLD). Zingerone (ZO) possess hepato-protective properties; thus, when administered neonatally, it could render protection against AFLD. This study aimed to evaluate the potential long-term protective effect of ZO against the development of AFLD. One hundred and twenty-three 10-day-old Sprague-Dawley rat pups (60 males; 63 females) were randomly assigned to four groups and orally administered the following treatment regimens daily during the pre-weaning period from postnatal day (PND) 12-21: group 1-nutritive milk (NM), group 2-NM +1 g/kg ethanol (Eth), group 3-NM + 40 mg/kg ZO, group 4-NM + Eth +ZO. From PND 46-100, each group from the neonatal stage was divided into two; subgroup I had tap water and subgroup II had ethanol solution as drinking fluid, respectively, for eight weeks. Mean daily ethanol intake, which ranged from 10 to 14.5 g/kg body mass/day, resulted in significant CYP2E1 elevation (p < 0.05). Both late single hit and double hit with alcohol increased liver fat content, caused hepatic macrosteatosis, dysregulated mRNA expression of SREBP1c and PPAR-α in male and female rats (p < 0.05). However, neonatal orally administered ZO protected against liver lipid accretion and SREBP1c upregulation in male rats only and attenuated the alcohol-induced hepatic PPAR-α downregulation and macrosteatosis in both sexes. This data suggests that neonatal orally administered zingerone can be a potential prophylactic agent against the development of AFLD.

Morphological features of hepatic lipid changes in bearded dragons (Pogona vitticeps), and a proposed grading system

Hepatic lipidosis is commonly diagnosed in pet bearded dragons (Pogona vitticeps). However, there are no studies detailing the histological features of hepatic lipid changes in this species. This study describes the microscopic features of lipid change and details an associated scoring system. Histologic hepatic sections were retrospectively evaluated from 252 bearded dragons submitted for necropsy. Pathologic assessment was used to develop a grading scheme with 2 qualitative, 1 quantitative, and 6 semi-quantitative microscopic parameters, which were refined based on variability. The final grading system developed for diffuse and panlobular lipid accumulation included 2 semi-quantitative and 1 quantitative categories: percentage of hepatocellular vacuolation, fibrosis, and hepatocellular swelling, respectively. Hepatocellular swelling was indirectly quantified by counting the number of nuclei per unit area. There was a strong positive correlation (P < .001) between the percentage of hepatocellular vacuolation and lipid content, a strong negative correlation (P < .001) between nuclear count and lipid content, and a moderate correlation (P < .001) between fibrosis and lipid content. Each category was given a numerical value ranging from 0 to 4, with the sum of each representing the final grade. Cutoff values stratified microscopic changes into mild (final grade 1-4), moderate (5-7), and severe (≥8). There was strong interrater agreement for assessment of vacuolization, fibrosis, and severity classification and moderate for hepatocellular swelling. This study documents the features of hepatic lipid changes in bearded dragons. Although a cutoff to differentiate pathologic from nonpathologic lipid accumulation could not be estimated, the proposed grading scheme can be used to inform future studies.

Histopathological Diagnosis of Nonalcoholic Steatohepatitis (NASH)

Nonalcoholic steatohepatitis (NASH) is part of a spectrum of conditions collectively referred to as nonalcoholic fatty liver disease (NAFLD). NASH/NAFLD is the most common chronic liver disease. NASH is defined as ≥5% hepatic steatosis along with hepatocellular injury. Histopathological features that indicate hepatocellular injury in NASH include ballooning degeneration, lobular inflammation, and apoptotic bodies. Scoring schemes, such as the NASH Clinical Research Network (CRN), use those histopathological features to grade the severity of the disease and determine a stage based on the amount of fibrosis. Among the NAFLD spectrum, NASH has the highest risk of developing fibrosis and progressing to liver cirrhosis. Therefore, accurate and timely diagnosis is crucial in order to initiate therapy and prevent disease complications as well as liver-related mortality. Although several imaging modalities and laboratory assays have been introduced to diagnose NASH, a liver biopsy remains the gold standard for diagnosing, grading, and staging the disease.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: Overlapping Mechanisms

Nonalcoholic fatty liver disease (NAFLD) denotes a condition with excess fat in the liver. The prevalence of NAFLD is increasing, averaging > 25% of the Western population. In 25% of the patients, NAFLD progresses to its more severe form: nonalcoholic steatohepatitis and >25% of these progress to cirrhosis following activation of inflammatory and fibrotic processes. NAFLD is associated with obesity, type 2 diabetes, and the metabolic syndrome and represents a considerable and increasing health burden. In the near future, NAFLD cirrhosis is expected to be the most common cause for liver transplantation. NAFLD patients have an increased risk of developing cardiovascular disease as well as liver-related morbidity. In addition, hepatic steatosis itself appears to represent an independent cardiovascular risk factor. In the present review, we provide an overview of the overlapping mechanisms and prevalence of NAFLD and cardiovascular disease.

Engineering multi-tissue units for regenerative Medicine: Bone-tendon-muscle units of the rotator cuff

Our body systems are comprised of numerous multi-tissue units. For the musculoskeletal system, one of the predominant functional units is comprised of bone, tendon/ligament, and muscle tissues working in tandem to facilitate locomotion. To successfully treat musculoskeletal injuries and diseases, critical consideration and thoughtful integration of clinical, biological, and engineering aspects are necessary to achieve translational bench-to-bedside research. In particular, identifying ideal biomaterial design specifications, understanding prior and recent tissue engineering advances, and judicious application of biomaterial and fabrication technologies will be crucial for addressing current clinical challenges in engineering multi-tissue units. Using rotator cuff tears as an example, insights relevant for engineering a bone-tendon-muscle multi-tissue unit are presented. This review highlights the tissue engineering strategies for musculoskeletal repair and regeneration with implications for other bone-tendon-muscle units, their derivatives, and analogous non-musculoskeletal tissue structures.

Primary Versus Secondary NAFLD: Perspective on Advanced Fibrosis

BACKGROUND

The presence of macrovesicular steatosis on liver biopsy is the commonest histopathological finding. Nonalcoholic fatty liver disease (NAFLD) is the presence of ≥5% macrovesicular steatosis without significant alcohol use. It is subdivided into primary and secondary NAFLD; information on their differences is limited.

AIM

To determine the histopathological differences between primary and secondary NAFLD and establish whether the prevalence of advanced fibrosis varies between the two types.

METHODOLOGY

Three years of retrospective study of 90 liver biopsies with ≥5% macrovesicular steatosis. Age, gender, clinical history, serum transaminase levels were noted. The biopsy was reviewed for steatosis, inflammation, and fibrosis. Differences between primary and secondary NAFLD for age, gender, AST/ALT ratio, histopathological features were determined. Descriptive statistical analysis, 2-tailed Student's t test, Chi-square test, Fisher's exact test were used, where p < 0.05 was considered significant.

RESULT

Primary and secondary NAFLD were 42 (46.7%) and 48 (53.3%), respectively. Inflammation was noted in 50 (55.5%) and fibrosis in 31 (34.4%). The prevalence of advanced fibrosis was 24.4%. Primary and secondary NAFLD differed significantly on ballooning degeneration, Mallory Denk bodies (MDBs), glycogenated nuclei, and fibrosis stage (p < 0.05). There were no significant differences among AST/ALT ratio, steatosis, and inflammation grade.

CONCLUSION

Primary NAFLD is a more severe type of liver disease. On histopathology, ballooning degeneration, MDBs, glycogenated nuclei, and advanced fibrosis was more prevalent in primary than secondary NAFLD.

Alcohol and Liver Clock Disruption Increase Small Droplet Macrosteatosis, Alter Lipid Metabolism and Clock Gene mRNA Rhythms, and Remodel the Triglyceride Lipidome in Mouse Liver

Heavy alcohol drinking dysregulates lipid metabolism, promoting hepatic steatosis – the first stage of alcohol-related liver disease (ALD). The molecular circadian clock plays a major role in synchronizing daily rhythms in behavior and metabolism and clock disruption can cause pathology, including liver disease. Previous studies indicate that alcohol consumption alters liver clock function, but the impact alcohol or clock disruption, or both have on the temporal control of hepatic lipid metabolism and injury remains unclear. Here, we undertook studies to determine whether genetic disruption of the liver clock exacerbates alterations in lipid metabolism and worsens steatosis in alcohol-fed mice. To address this question, male liver-specific Bmal1 knockout (LKO) and flox/flox (Fl/Fl) control mice were fed a control or alcohol-containing diet for 5 weeks. Alcohol significantly dampened diurnal rhythms of mRNA levels in clock genes Bmal1 and Dbp, phase advanced Nr1d1/REV-ERBα, and induced arrhythmicity in Clock, Noct, and Nfil3/E4BP4, with further disruption in livers of LKO mice. Alcohol-fed LKO mice exhibited higher plasma triglyceride (TG) and different time-of-day patterns of hepatic TG and macrosteatosis, with elevated levels of small droplet macrosteatosis compared to alcohol-fed Fl/Fl mice. Diurnal rhythms in mRNA levels of lipid metabolism transcription factors (Srebf1, Nr1h2, and Ppara) were significantly altered by alcohol and clock disruption. Alcohol and/or clock disruption significantly altered diurnal rhythms in mRNA levels of fatty acid (FA) synthesis and oxidation (Acaca/b, Mlycd, Cpt1a, Fasn, Elovl5/6, and Fads1/2), TG turnover (Gpat1, Agpat1/2, Lpin1/2, Dgat2, and Pnpla2/3), and lipid droplet (Plin2/5, Lipe, Mgll, and Abdh5) genes, along with protein abundances of p-ACC, MCD, and FASN. Lipidomics analyses showed that alcohol, clock disruption, or both significantly altered FA saturation and remodeled the FA composition of the hepatic TG pool, with higher percentages of several long and very long chain FA in livers of alcohol-fed LKO mice. In conclusion, these results show that the liver clock is important for maintaining temporal control of hepatic lipid metabolism and that disrupting the liver clock exacerbates alcohol-related hepatic steatosis.