Non-alcoholic fatty liver disease: An expanded review

Perioperative treatment with cilostazol reverses steatosis and improves liver regeneration after major hepatectomy in a steatotic rat model

Cilostazol has previously been shown to reduce liver steatosis and enhance hepatic perfusion. We investigated the effects of cilostazol after major hepatectomy in a steatotic rat model. Six weeks prior to surgery, Sprague-Dawley rats were fed with a high-fructose diet. The treatment group received daily 5 mg/kg cilostazol. Seven days following the cilostazol treatment, all animals underwent 70% liver resection (PHX). Analysis of hepatic blood flow and microcirculation and immunohistochemical examinations were conducted 30 min after PHX (postoperative day [POD] 0) as well as on POD 1, POD 3 and POD 7. The weight of cilostazol-treated animals was significantly reduced compared to untreated controls after completion of the 6-week high-FRC diet. Furthermore, 41% macrovesicular steatosis was found in the control group compared to 8% in the cilostazol group. Hepatic arterial and portal venous perfusion were increased in the cilostazol group on POD 7. Lower liver enzyme release was found postoperatively in cilostazol-treated animals. Moreover, apoptosis and neutrophil infiltration were reduced after cilostazol treatment. Proliferation of hepatocytes and liver regeneration after PHX were significantly increased in the cilostazol group. Consequently, cilostazol should be evaluated as a novel strategy to reduce the rate of liver failure after PHX in steatotic liver.

Endonuclease G promotes hepatic mitochondrial respiration by selectively increasing mitochondrial tRNAThr production

Mitochondrial endonuclease G (EndoG) contributes to chromosomal degradation when it is released from mitochondria during apoptosis. It is presumed to also have a mitochondrial function because EndoG deficiency causes mitochondrial dysfunction. However, the mechanism by which EndoG regulates mitochondrial function is not known. Fat accumulation in metabolic dysfunction-associated steatotic liver disease (MASLD), which is more common in men, is caused in part by mitochondrial dysfunction. EndoG expression is reduced in MASLD liver, and EndoG deficiency causes MASLD in an obesity-independent manner but only in males. EndoG promotes mitochondrial respiration by resolving mitochondrial tRNA/DNA hybrids formed during mtDNA transcription by recruiting RNA helicase DHX30 to unwind them. EndoG also cleaves off the 3'-end of the H-strand transcript that can prevent mt-tRNAThr precursor cloverleaf-folding, and processing, which increases mt-tRNAThr production and mitochondrial translation. Using fluorescent lifetime imaging microscopy technology to visualize oxygen consumption at the individual mitochondrion level, we found that EndoG deficiency leads to the selective loss of a mitochondrial subpopulation with high-oxygen consumption. This defect was reversed with mt-tRNAThr supplementation. Thus, EndoG promotes mitochondrial respiration by selectively regulating the production of mt-tRNAThr in male mice.

Investigation of Active Components of Meconopsis integrifolia (Maxim.) Franch in Mitigating Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has rapidly emerged as the most prevalent chronic liver disease globally, representing a significant and escalating public health challenge. Meconopsis integrifolia (Maxim.) Franch, a traditional Tibetan medicinal herb used for treating hepatitis, remains largely unexplored regarding its therapeutic potential and active components in combating NAFLD. This study first evaluated the in vitro lipid accumulation inhibitory activity of different extraction fractions of M. integrifolia using a HepG2 cell steatosis model. The ethyl acetate fraction was found to significantly reduce triglyceride (TG) and low-density lipoprotein (LDL) levels, inhibit lipid droplet deposition in HepG2 cells, and promote lipid metabolism balance through modulation of the AMPK/SREPB-1c/PPAR-α signaling pathway. Further analysis utilizing chromatographic techniques and nuclear magnetic resonance spectroscopy (NMR) led to the isolation of 13 compounds from the active ethyl acetate fraction. Notably, compounds 6, 9, 10, 11, 12, and 13 were identified for the first time from this Tibetan herb. In vitro activity assays and molecular docking analyses further confirmed that the compounds Luteolin (1), Quercetin 3-O-[2‴, 6‴-O-diacetyl-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside] (6), and Quercetin 3-O-[2‴-O-acetyl-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside] (8) are potential key components responsible for the NAFLD-ameliorating effects of M. integrifolia. This study highlights the therapeutic potential of M. integrifolia in treating NAFLD and provides a foundation for its further development and application, underscoring its significance in the advanced utilization of traditional Tibetan medicine.

Metformin's effect on metabolic dysfunction-associated steatotic liver disease through the miR-200a-5p and AMPK/SERCA2b pathway

Introduction

Metformin has shown benefits in treating metabolic dysfunction-associated steatotic liver disease (MASLD), but its mechanisms remain unclear. This study investigates miR-200a-5p's role in the AMPK/SERCA2b pathway to reduce liver fat accumulation and ER stress in MASLD.

Methods

A PA cell model induced by palmitic and oleic acids (2:1) was used to assess lipid accumulation via Oil Red O and Nile Red staining. mRNA levels of miR-200a-5p and lipid metabolism genes were measured with RT-PCR, and AMPK, p-AMPK, and SERCA2b protein levels were analyzed by Western blotting. The interaction between miR-200a-5p and AMPK was studied using a luciferase reporter assay. A high-fat diet-induced MASLD mouse model was used to evaluate metformin's effects on liver steatosis and lipid profiles. Serum miR-200a-5p levels were also analyzed in MASLD patients.

Results

In the PA cell model, elevated miR-200a-5p and lipid metabolism gene mRNA levels were observed, with decreased AMPK and SERCA2b protein levels. miR-200a-5p mimic reduced AMPK and SERCA2b expression. Metformin treatment reduced liver steatosis and lipid deposition in mice, normalizing miR-200a-5p, lipid metabolism gene mRNA, and AMPK/SERCA2b protein levels. Elevated serum miR-200a-5p was detected in MASLD patients.

Discussion

These findings suggest that metformin alleviates lipid deposition and ER stress in MASLD through the modulation of the AMPK/SERCA2b pathway via miR-200a-5p.

The Effect of Quercetin on Non-Alcoholic Fatty Liver Disease (NAFLD) and the Role of Beclin1, P62, and LC3: An Experimental Study

Background/Objectives: Non-alcoholic fatty liver disease (NAFLD) is a major metabolic disorder with no established pharmacotherapy. Quercetin, a polyphenolic flavonoid, demonstrates potential hepatoprotective effects but has limited bioavailability. This study evaluates the impact of quercetin on NAFLD and assesses the roles of autophagy-related proteins in disease progression. Methods: Forty-seven male C57BL/6J mice were fed a high-fat diet (HFD) for 12 weeks to induce NAFLD, followed by quercetin treatment for 4 weeks. Mice were divided into baseline, control, and two quercetin groups, receiving low (10 mg/kg) and high (50 mg/kg) doses. Liver histology was scored using the NAFLD Activity Score (NAS). Immunohistochemistry and immunoblotting were performed to analyze autophagy markers. Results: Quercetin-treated groups showed significant reductions in NAS compared to controls (p = 0.011), mainly in steatosis and steatohepatitis. Immunohistochemistry indicated increased expression of autophagy markers LCA and p62 in quercetin groups. Western blot analysis revealed significant elevations in LC3A in the treated groups, suggesting improved autophagic activity and lipid degradation. Conclusions: Quercetin effectively reduces NAFLD severity and modulates autophagy-related proteins. These findings suggest that quercetin enhances autophagic flux, supporting its therapeutic potential for NAFLD. Additional research is needed to clarify the molecular mechanisms of quercetin and to determine the optimal dosing for clinical application.

A Survey Assessing Nonalcoholic Fatty Liver Disease Knowledge Among Hepatologists and Non-Hepatologists in China

Background and Aim

A global increase in nonalcoholic fatty liver disease (NAFLD) prevalence has been observed in the last decade. This study assesses knowledge, awareness, and clinical practice gaps of hepatologists and non-hepatologists in NAFLD management across hospitals in China.

Methods

A web-based quantitative survey was conducted, and participants included hepatologists (gastroenterologists and infectious disease specialists) and non-hepatologists (internal medicine specialists, cardiologists, and pharmacists) from various hospitals across China.

Results

In total, 1627 healthcare practitioners (HCPs) responded to the survey. This included 658 hepatologists and 969 non-hepatologists. In comparison to 92.6% hepatologists, only 58.0% of non-hepatologists were aware of NAFLD. A higher proportion of hepatologists (82.8%) performed screening for NAFLD compared to non-hepatologists (56.9%). Majority of the hepatologists (70%) and non-hepatologists (67%) were aware of the four primary recommendations for managing NAFLD. Only 11% of hepatologists did not manage NAFLD patients, mainly because they felt they did not have enough time (66.7%). Of the 36% non-hepatologists who did not manage NAFLD, 78.4% stated that NAFLD is not their specialty, and 38.6% were not familiar with the treatment options.

Conclusion

Most hepatologists were aware of and agreed to performing screening for NAFLD compared to non-hepatologists. Both hepatologists and non-hepatologists exhibited similar level of understanding on NAFLD management. However, a small percentage of both hepatologists and non-hepatologists admitted that they did not manage NAFLD patients because they were not familiar with available treatment options. This underscores the importance of further educating HCPs involved in managing NAFLD.

Quercetin's Potential in MASLD: Investigating the Role of Autophagy and Key Molecular Pathways in Liver Steatosis and Inflammation

Metabolic dysfunction-associated fatty liver disease (MASLD) is a widespread liver disorder characterized by excessive fat accumulation in the liver, commonly associated with metabolic syndrome components such as obesity, diabetes, and dyslipidemia. With a global prevalence of up to 30%, MASLD is projected to affect over 100 million people in the U.S. and 20 million in Europe by 2030. The disease ranges from Steatotic Lived Disease (SLD) to more severe forms like metabolic dysfunction-associated steatohepatitis (MASH), which can progress to cirrhosis and hepatocellular carcinoma. Autophagy, a cellular process crucial for lipid metabolism and homeostasis, is often impaired in MASLD, leading to increased hepatic lipid accumulation and inflammation. Key autophagy-related proteins, such as Beclin1, LC3A, SQSTM1 (p62), CD36, and Perilipin 3, play significant roles in regulating this process. Disruption in these proteins contributes to the pathogenesis of MASLD. Quercetin, a natural polyphenolic flavonoid with antioxidant and anti-inflammatory properties, has promising results in mitigating MASLD. It may reduce hepatic lipid accumulation, improve mitochondrial function, and enhance autophagy. However, further research is needed to elucidate its mechanisms and validate its therapeutic potential in clinical settings. This underscores the need for continued investigation into autophagy and novel treatments for MASLD.

Liver fibrosis prediction models in a population of Latina and White women

Point-of-care tools to assess advanced liver fibrosis, including the NFS, BARD, FIB-4, and APRI, are of major interest due to their noninvasive nature. However, these tools have not been investigated extensively in the Latina population. Given that the highest rate of NAFLD in Latinos and the most severe presentation of non-alcoholic fatty liver disease (NAFLD) is more common in women, we hypothesize that ethnicity may play a role in predicting liver fibrosis, particularly in women. We determined whether ethnicity alone or in association with other parameters can predict the severity of fibrosis in women with NAFLD when included in four tools. We retrospectively included 562 Latina and 133 White Caucasian women with a history of NAFLD. Associations between ethnicity and liver fibrosis severity using the four fibrosis predictor models were studied using backward selection multinomial logistic regression. Latina women compared to White showed lower body mass index (p < 0.001), higher HbA1c (p < 0.001), lower prevalence of bariatric surgery (p < 0.001), lower likelihood to smoke (p = 0.003), and higher prevalence of chronic kidney disease stages 3-5 (p = 0.01). Some clinical variables were associated with fibrosis but not univocally in each tool. We did not find differences in the outcome of the four models when holding all other factors and examining ethnicity alone between Latina and White women. Although we did not include data on liver histology, this is the first study examining the role of ethnicity in predicting the severity of fibrosis using established noninvasive scores and documenting no association between Latina ethnicity and the severity of fibrosis in women with NAFLD.

Role of Omega-3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA) as modulatory and anti-inflammatory agents in noncommunicable diet-related diseases - Reports from the last 10 years

BACKGROUND & AIMS

Fatty acids are a fundamental component of the human diet, particularly polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The importance of omega-3 fatty acids has been studied in the context of many diseases due to their pleiotropic effects, focusing on the anti-inflammatory effects of EPA and DHA. Currently, the results of these acids in noncommunicable diseases are being increasingly assessed in a broader context than just inflammation. However, the mechanisms underlying the modulatory and anti-inflammatory effects of omega-3 fatty acids remain the subject of intensive research. Therefore, we reviewed the literature covering articles from the last decade to assess not only the anti-inflammatory but, above all, the modulatory effect of EPA and DHA acids on noncommunicable diet-related diseases.

METHODS

The PubMed, Web of Science and Scopus databases were searched for studies regarding the effects of omega-3 fatty acids on diet-related disorders from the last 10 years.

RESULTS

The available research shows that EPA and DHA supplementation has a beneficial impact on regulating triglycerides, total cholesterol, insulin resistance, blood pressure, liver enzymes, inflammatory markers and oxidative stress. Additionally, there is evidence of their potential benefits in terms of mitochondrial function, regulation of plasma lipoproteins, and reduction of the risk of sudden cardiovascular events associated with atherosclerotic plaque rupture.

CONCLUSIONS

Omega-3 polyunsaturated fatty acids (EPA, DHA) have many beneficial effects among patients with diet-related disorders. More well-designed randomised controlled trials are needed to fully determine the usefulness of EPA and DHA in treating and preventing noncommunicable diet-related diseases.

Clinical model to predict the risk of nonalcoholic fatty liver disease: A secondary analysis of data from a cross-sectional study

This study aimed to develop and validate a clinical model for predicting the risk of nonalcoholic fatty liver disease (NAFLD) by using data from a cross-sectional study. This investigation utilized data from the Dryad database and employed multivariable logistic regression analysis, restricted cubic spline, and nomogram analysis to achieve comprehensive insights. The discrimination and calibration of the nomogram were evaluated using the receiver operating characteristic curve and calibration plot. A total of 1072 patients were included in the study, including 456 with non-NAFLD and 616 with NAFLD. Significant differences were observed in terms of sex, body mass index (BMI), tobacco, hypertension, diabetes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), ALT/AST ratio, uric acid (UA), fasting blood glucose (FBG), triglyceride (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, systolic blood pressure, and diastolic blood pressure (P < .05 for all comparisons). Multivariable logistic regression analysis indicated that sex, BMI, diabetes, ALT/AST ratio, UA, FBG, and TG were associated with an increased risk of NAFLD. Restricted cubic spline indicated a nonlinear relationship between the risk of NAFLD and variables including ALT/AST ratio, FPG, TG, and UA (P for nonlinearity < .01). The variables in the nomogram included BMI, diabetes, ALT/AST ratio, UA, FBG, and TG. The value of area under the curve was 0.790, indicating that the nomogram prediction model exhibited significant discriminatory accuracy. A reliable clinical model for predicting the risk of NAFLD was developed using readily available clinical data. The model can assist clinicians in identifying individuals with an increased risk of NAFLD, enabling early interventions for preventing and managing this prevalent liver disease.

Paricalcitol attenuates oxidative stress and inflammatory response in the liver of NAFLD rats by regulating FOXO3a and NFκB acetylation

The lack of therapeutics along with complex pathophysiology made non-alcoholic fatty liver disease (NAFLD) a research hotspot. Studies showed that the deficiency of Vitamin D plays a vital role in NAFLD pathogenesis. While several research studies focused on vitamin D supplementation in NAFLD, there is still a need to understand the regulatory mechanism of direct vitamin D receptor activation in NAFLD. In the present study, we explored the role of direct Vitamin D receptor activation using paricalcitol in choline-deficient high-fat diet-induced NAFLD rat liver and its modulation on protein acetylation. Our results showed that paricalcitol administration significantly reduced the fat accumulation in HepG2 cells and the liver of NAFLD rats. Paricalcitol attenuated the elevated serum level of alanine transaminase, aspartate transaminase, insulin, low-density lipoprotein, triglyceride, and increased high-density lipoprotein in NAFLD rats. Paricalcitol significantly decreased the increased total protein acetylation by enhancing the SIRT1 and SIRT3 expression in NAFLD liver. Further, the study revealed that paricalcitol reduced the acetylation of NFκB and FOXO3a in NAFLD liver along with a decrease in the mRNA expression of IL1β, NFκB, TNFα, and increased catalase and MnSOD. Moreover, total antioxidant activity, glutathione, and catalase were also elevated, whereas lipid peroxidation, myeloperoxidase, and reactive oxygen species levels were significantly decreased in the liver of NAFLD after paricalcitol administration. The study concludes that the downregulation of SIRT1 and SIRT3 in NAFLD liver was associated with an increased acetylated NFκB and FOXO3a. Paricalcitol effectively reversed hepatic inflammation and oxidative stress in NAFLD rats through transcriptional regulation of NFκB and FOXO3a, respectively, by inhibiting their acetylation.

Ultrasound-estimated hepatorenal index: diagnostic performance and interobserver agreement for pediatric liver fat quantification

BACKGROUND

Semiquantitative and quantitative sonographic techniques have the potential for screening and surveillance of children at risk of nonalcoholic fatty liver disease.

OBJECTIVE

To determine diagnostic performance and interobserver agreement of hepatorenal index (HRI) for pediatric ultrasound-based liver fat quantification.

MATERIALS AND METHODS

In an institutional review board (IRB)-approved retrospective study (April 2014 to April 2023), children (< 18 years) with clinically performed magnetic resonance imaging (MRI) scans for liver fat quantification were assessed. Inclusion criteria required availability of abdominal ultrasound within 3 months of quantitative MRI. Three blinded readers subjectively assessed for sonographic hepatic steatosis and calculated HRI. MRI proton density fat fraction (PDFF) was the reference standard. Interobserver agreement, correlation with PDFF, and optimal HRI (using ROC analysis) values were analyzed. The significance level was set at p < 0.05.

RESULTS

A total of 41 patients (25 male) with median (interquartile range (IQR)) age of 13 (10-15) years were included. Median (IQR) MRI PDFF was 11.30% (2.70-17.95%). Hepatic steatosis distribution by MRI PDFF included grade 0 (34%), grade 1 (15%), grade 2 (22%), and grade 3 (29%) patients. Intraclass correlation coefficient for HRI among the three readers was 0.61 (95% CI 0.43-0.75) (p < 0.001). Moderate correlation was observed between manually estimated HRI and PDFF for each reader (r = 0.62, 0.67, and 0.67; p < 0.001). Optimal HRI cutoff was found to be 1.99 to diagnose hepatic steatosis (sensitivity 89%, specificity 93%). Median (IQR) HRI for each MRI grade of hepatic steatosis (0-4) was as follows: 1.2 (1.1-1.5), 2.6 (1.1-3.3), 3.6 (2.6-5.4), 5.6 (2.6-10.9), respectively (p < 0.001).

CONCLUSION

Ultrasound-estimated HRI has moderate interobserver agreement and moderate correlation with MRI-derived PDFF. HRI of 1.99 maximizes accuracy for identifying pediatric liver fat.

The mitochondrial translocator protein (TSPO, 18 kDa): A key multifunctional molecule in liver diseases

Translocator protein (TSPO, 18 kDa), previously known as peripheral-type benzodiazepine receptor, is an evolutionarily conserved and tryptophan-rich 169-amino-acid protein located on the outer mitochondrial membrane. TSPO plays a crucial role in various fundamental physiological functions and cellular processes. Its expression is altered in pathological conditions, thus rendering TSPO a potential tool for diagnostic imaging and an appealing therapeutic target. The investigation of synthetic TSPO ligands as both agonists and antagonists has provided valuable insights into the regulatory mechanisms and functional properties of TSPO. Recently, accumulating evidence has highlighted the significance of TSPO in liver diseases. However, a comprehensive summary of TSPO function in the normal liver and diverse liver diseases is lacking. This review aims to provide an overview of recent advances in understanding TSPO function in both normal liver cells and various liver diseases, with a particular emphasis on its involvement in liver fibrosis and inflammation and addresses the existing knowledge gaps in the field that require further investigation.