Nonalcoholic steatohepatitis: the new frontier for liver transplantation. Curr Opin Organ Transplant. 2018;23:169-174. [PMID: 29356708 DOI: 10.1097/mot.0000000000000502]

Optimizing cardiac status in the preliver transplant candidate

PURPOSE OF REVIEW

Liver transplant is a widely accepted therapy for end-stage liver disease. With advances in our understanding of transplant, candidates are increasingly older with more cardiac comorbidities. Cardiovascular disease also represents a leading cause of morbidity and mortality posttransplant.

RECENT FINDINGS

Preoperative cardiac risk stratification and treatment may improve short-term and long-term outcomes after liver transplant. Importantly, the appropriate frequency of surveillance has not been defined. Optimal timing of cardiac intervention in end-stage liver disease is likewise uncertain.

SUMMARY

The approach to risk stratification of cardiovascular disease in end-stage liver disease is outlined, incorporating the AHA/ACC scientific statement on evaluation of cardiac disease in transplant candidates and more recent expert consensus documents. Further study is needed to clarify the ideal timing and approach for cardiovascular interventions.

Recompensation in cirrhosis: unravelling the evolving natural history of nonalcoholic fatty liver disease

Recompensation has gained increasing attention in the field of cirrhosis, particularly in chronic liver disease with a definite aetiology. The current global prevalence of obesity and nonalcoholic fatty liver disease (NAFLD) is increasing, but there is currently a lack of a clear definition for recompensation in NAFLD-related cirrhosis. Here, we provide an up-to-date perspective on the natural history of NAFLD, emphasizing the reversible nature of the disease, summarizing possible mechanisms underlying recompensation in NAFLD, discussing challenges that need to be addressed and outlining future research directions in the field. Recompensation is a promising goal in patients with NAFLD-related cirrhosis, and further studies are needed to explore its underlying mechanisms and uncover its clinical features.

The molecular phenotypes of injury, steatohepatitis, and fibrosis in liver transplant biopsies in the INTERLIVER study

To extend previous molecular analyses of rejection in liver transplant biopsies in the INTERLIVER study (ClinicalTrials.gov #NCT03193151), the present study aimed to define the gene expression selective for parenchymal injury, fibrosis, and steatohepatitis. We analyzed genome-wide microarray measurements from 337 liver transplant biopsies from 13 centers. We examined expression of genes previously annotated as increased in injury and fibrosis using principal component analysis (PCA). PC1 reflected parenchymal injury and related inflammation in the early posttransplant period, slowly regressing over many months. PC2 separated early injury from late fibrosis. Positive PC3 identified a distinct mildly inflamed state correlating with histologic steatohepatitis. Injury PCs correlated with liver function and histologic abnormalities. A classifier trained on histologic steatohepatitis predicted histologic steatohepatitis with cross-validated AUC = 0.83, and was associated with pathways reflecting metabolic abnormalities distinct from fibrosis. PC2 predicted histologic fibrosis (AUC = 0.80), as did a molecular fibrosis classifier (AUC = 0.74). The fibrosis classifier correlated with matrix remodeling pathways with minimal overlap with those selective for steatohepatitis, although some biopsies had both. Genome-wide assessment of liver transplant biopsies can not only detect molecular changes induced by rejection but also those correlating with parenchymal injury, steatohepatitis, and fibrosis, offering potential insights into disease mechanisms for primary diseases.

Cardiovascular risk stratification in the noncardiac solid organ transplant candidate

PURPOSE OF REVIEW

Solid organ transplantation (SOT) has become a widely accepted therapy for end-stage disease across the spectrum of thoracic and abdominal organs. With contemporary advances in medical and surgical therapies in transplantation, candidates for SOT are increasingly older with a larger burden of comorbidities, including cardiovascular disease (CVD). CVD, in particular, is a leading cause of morbidity and mortality in SOT candidates with end-stage disease of noncardiac organs [1].

RECENT FINDINGS

Identification of coronary artery disease (CAD), heart failure, and valvular disease are important in noncardiac SOT to ensure both appropriate peri-transplant management and equitable organ allocation. Although the American College of Cardiology (ACC) and the American Heart Association (AHA) have published guidelines and recommendations for the perioperative cardiovascular evaluation of patients undergoing noncardiac surgery, the implications of both symptomatic and asymptomatic CVD differ in patients with end-stage organ failure being considered for SOT when compared to the general population.

SUMMARY

Herein, we review the epidemiology, diagnosis, and evidence for the management of CVD in kidney and liver transplantation, combining current guidelines from the 2012 ACC/AHA scientific statement on cardiac disease evaluation in SOT with more contemporary evidenced-based algorithms.

Transcatheter interventions for valvular heart diseases in liver cirrhosis patients

There is an increasing prevalence of patients who have both liver cirrhosis (LC) and severe valvular heart disease. This combination typically poses prohibitive risk for liver transplantation. LC related malnourishment, hypoalbuminemia and hyperdynamic circulation places patients with severe LC at higher rates for significant bleeding and/or thrombosis, as well as infectious and renal complications, after either surgical or transcatheter valvular interventions. Although there remains scarce comparative evidence, the preponderance of data suggest that percutaneous strategies are preferred over surgical ones. A multidisciplinary team is ideal for identifying those patients with LC who would benefit from transcatheter valvular heart interventions.

Sirt1 Promotes the Restoration of Hepatic Progenitor Cell (HPC)-Mediated Liver Fatty Injury in NAFLD Through Activating the Wnt/β-Catenin Signal Pathway

Non-alcoholic fatty liver disease (NAFLD) has developed into the world's largest chronic epidemic. In NAFLD, hepatic steatosis causes hepatocytes dysfunction and even apoptosis. The liver has a strong restoration or regeneration ability after an injury, however, it is unclear through which pattern fatty liver injury in NAFLD is repaired and what the repair mechanism is. Here, we found that in the high-fat diet (HFD)-induced NAFLD mice model, fatty liver injury caused the significant ductular reaction (DR), which is a marker to promote the repair of liver injury. SOX9⁺ and HNF4α⁺ biphenotype also suggested that hepatic progenitor cells (HPCs) were activated by fatty liver injury in the HFD-elicited NAFLD mice model. Concurrently, fatty liver injury also activated the Wnt/β-catenin signal pathway, which is a necessary process for HPC differentiation into mature hepatocytes. However, Sirt1 knockdown weakened HPC activation and Wnt/β-catenin signal in Sirt1^+/− mice with HFD feeding. In rat-derived WB-F344 hepatic stem cell line, Sirt1 overexpression (OE) or Sirt1 activator–Resveratrol promoted HPC differentiation via activating Wnt/β-catenin signal pathway. Glycogen PAS staining demonstrated that Sirt1 OE promoted WB-F344 cells to differentiate into mature hepatocytes with glycogen synthesis ability, while Sirt1 inhibitor EX527 or Wnt/β-catenin pathway inhibitor HF535 decreased glycogen positive cells. Together, our data suggested that Sirt1 plays a vital role in activating HPCs to repair fatty liver injury or promote liver regeneration through the Wnt/β-catenin signal pathway in NAFLD, which might provide a new strategy for fatty liver injury or NAFLD therapy.

Factors That Predict the Progression of Non-alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) refers to a spectrum of diseases involving the deposition of fat in the hepatocytes of people with little to no alcohol consumption. NAFLD is associated with hypertension, diabetes, obesity, etc. As their prevalence increases, the propensity and severity of NAFLD might increase. As per the recently developed multi-hit hypothesis, factors like oxidative stress, genetic predisposition, lipotoxicity, and insulin resistance have been found to play a key role in the development of NAFLD and its associated complications. This article focuses on NAFLD, its pathophysiology, risk factors, and the various genetic and epigenetic factors involved in its development along with possible treatment modalities.

We conducted an all-language literature search on Medline, Cochrane, Embase, and Google Scholar until October 2021. The following search strings and Medical Subject Heading (MeSH) terms were used: “NAFLD,” “NASH,” “Fibrosis,” and “Insulin Resistance.” We explored the literature on NAFLD for its epidemiology, pathophysiology, the role of various genes, and how they influence the disease and associated complications about the disease and its hepatic and extrahepatic complications. With its rapidly increasing prevalence rates across the world and serious complications like NASH and hepatocellular carcinoma, NAFLD is becoming a major public health issue and more research is needed to formulate better screening tools and treatment protocols.

Burden of non-alcoholic fatty liver disease in Asia, the Middle East and North Africa: Data from Global Burden of Disease 2009-2019

BACKGROUND & AIM

Non-alcoholic fatty liver disease (NAFLD) has become a major cause of chronic liver disease (CLD) worldwide. Our aim was to assess the burden of liver complications (LC, cirrhosis and liver cancer) related to NAFLD (LC-NAFLD) between 2009-2019 in Asia and the Middle East and North Africa (MENA) region.

METHODS

We used Global Burden of Disease data to assess incidence, mortality, and disability-adjusted life years (DALYs) for LC-NAFLD from Asia and the MENA region. Annual % change (APC) in rates were computed using a joinpoint regression model. Associations of LC-NAFLD with low physical activity, diet and metabolic risks were determined by partial Spearman correlation coefficients (ρ).

RESULTS

Globally in 2019, there were 170,000 incident cases of LC-NAFLD, accounting for 6.6% of LC incident cases from all CLDs. There were 168,969 deaths related to LC-NAFLD, accounting for 8.6% of LC deaths from all CLDs. Asia accounted for 48.3% of the global incidence of LC-NAFLD and for 46.2% of deaths attributable to LC-NAFLD, while MENA accounted for 8.9% and 8.6%, respectively. There were 2.08 million DALYs in Asia and 340,000 DALYs in MENA. From 2009 to 2019, regions in Asia and MENA experienced a rise in DALYs attributable to LC-NAFLD (compared to LC from other CLDs), ranging from South Asia (APC = +2.12% vs. -0.94%) to high-income Asia Pacific (APC = -0.07%, p = 0.646 vs. -0.97%). In Asia, NAFLD-related DALYs were significantly correlated with dietary risks (95% CI 0.280-0.763, p = 0.004), metabolic risks (0.341-0.790, p <0.001) and tobacco use (0.134-0.691, p = 0.007). In MENA, low physical activity (0.557-0.918, p <0.001), metabolic risks (0.432-0.888, p = 0.001), and dietary risks (0.315-0.855, p = 0.001) correlated with DALYs.

CONCLUSIONS

NAFLD is posing a substantial burden in Asia and MENA. About half of the global burden of LC-NAFLD is accounted for by these regions.

LAY SUMMARY

Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the most common causes of chronic liver disease worldwide. We used Global Burden of Disease data to assess the incidence, mortality, and disability-adjusted life years attributable to NAFLD-related liver complications in Asia, the Middle East and North Africa. NAFLD is poised to contribute to a substantial liver disease burden in these regions. Regional and global policies are needed to address the increasing burden of complications of NAFLD.

Bariatric surgery and the liver-Mechanisms, benefits, and risks

The prevalence of obesity and metabolic diseases such as type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has risen dramatically over the past decades. At present, bariatric surgery is the most effective treatment for this global health problem, through effects on food intake, gut hormone secretion, metabolic signaling pathways, and adipose tissue dysfunction. The liver occupies a central role in carbohydrate, protein, and lipid metabolism. Notably, a reduction in hepatic fat content and an improvement in hepatic insulin resistance are among the earliest beneficial effects of bariatric surgery, which has therefore emerged as an attractive treatment option for NAFLD. However, as the scope and popularity of weight loss surgery have expanded, new questions have arisen regarding its safety in patients with liver cirrhosis, the outcome of liver transplantation in patients with a history of bariatric surgery, and over incidental reports of liver failure following surgery. Studies in humans and rodents have also linked bariatric surgery to an increased risk of developing alcohol use disorder, a major risk factor for liver disease. This review integrates data from clinical and translational research to delineate both the beneficial impact of bariatric surgery on the liver and the potential risks involved.

The Troubling Link Between Non-alcoholic Fatty Liver Disease (NAFLD) and Extrahepatic Cancers (EHC)

Non-alcoholic fatty liver disease (NAFLD) is a fast-spreading epidemic across the globe and has serious implications far beyond that of a "benign" liver condition. It is usually an outcome of ectopic fat storage due to chronic positive energy balance leading to obesity and is associated with multiple health problems. While association with cardiovascular disease and hepatocellular cancer is well recognized, it is becoming clear the NAFLD carries with it an increased risk of cancers of extrahepatic tissues. Studies have reported a higher risk for cancers of the colon, breast, prostate, lung, and pancreas. Fatty liver is associated with increased mortality; there is an urgent need to understand that fatty liver is not always benign, and not always associated with obesity. It is, however, a reversible condition and early recognition and intervention can alter its natural history and associated complications.

Augmenter of liver regeneration ameliorates ischemia-reperfusion injury in steatotic liver via inhibition of the TLR4/NF-κB pathway

Hepatocytes from donors with preexisting hepatic steatosis exhibited increased sensitivity to ischemia-reperfusion injury (IRI) during liver transplantation. Augmenter of liver regeneration (ALR) protected the liver against IRI, but the mechanism was not clarified. Therefore, the hypothesis that ALR attenuated IRI in steatotic liver by inhibition of inflammation and downregulation of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway was examined. C57BL/6 mice were subjected to a methionine-choline-deficient (MCD) diet to induce liver steatosis. Mice were transfected with ALR-containing adenovirus 3 days prior to partial warm hepatic IRI. After 30 min of ischemia and 6 h of reperfusion injury, liver function, hepatic injury, the inflammatory response and TLR4/NF-κB signaling pathway activation were assessed. ALR maintained liver function and alleviated hepatic injury as indicated by the decreased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), preserved hepatic structure and reduced apoptosis. ALR also reduced the IRI-induced inflammatory response by suppressing Kupffer cell activation, inhibiting neutrophil chemotaxis and reducing inflammatory cytokine production. Further investigation using reverse transcription-quantitative PCR, western blotting and immunohistochemistry revealed that ALR reduced TLR4/NF-κB signaling pathway activation, which led to a decreased synthesis of inflammatory cytokines. ALR functioned as a regulator of the IRI-induced inflammatory response by suppressing the TLR4/NF-κB pathway, which supports the use of ALR in therapeutic applications for fatty liver transplantation.

The Evaluation of Drug Delivery Nanocarrier Development and Pharmacological Briefing for Metabolic-Associated Fatty Liver Disease (MAFLD): An Update

Current research indicates that the next silent epidemic will be linked to chronic liver diseases, specifically non-alcoholic fatty liver disease (NAFLD), which was renamed as metabolic-associated fatty liver disease (MAFLD) in 2020. Globally, MAFLD mortality is on the rise. The etiology of MAFLD is multifactorial and still incompletely understood, but includes the accumulation of intrahepatic lipids, alterations in energy metabolism, insulin resistance, and inflammatory processes. The available MAFLD treatment, therefore, relies on improving the patient's lifestyle and multidisciplinary pharmacotherapeutic options, whereas the option of surgery is useless without managing the comorbidities of the MAFLD. Nanotechnology is an emerging approach addressing MAFLD, where nanoformulations are suggested to improve the safety and physicochemical properties of conventional drugs/herbal medicines, physical, chemical, and physiological stability, and liver-targeting properties. A wide variety of liver nanosystems were constructed and delivered to the liver, only those that addressed the MAFLD were discussed in this review in terms of the nanocarrier classes, particle size, shape, zeta potential and offered dissolution rate(s), the suitable preparation method(s), excipients (with synergistic effects), and the suitable drug/compound for loading. The advantages and challenges of each nanocarrier and the focus on potential promising perspectives in the production of MAFLD nanomedicine were also highlighted.

Metabolomic-proteomic combination analysis reveals the targets and molecular pathways associated with hydrogen sulfide alleviating NAFLD

AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease worldwide. Exogenous H₂S has been shown to effectively mitigate NAFLD, although little is known about the underlying targets and molecular mechanisms.

METHODS

C57BL/6 mice were fed with normal fat diet (NFD) or high fat diet (HFD) for a total 16 weeks, and HFD-fed mice were treated with saline or NaHS beginning in 12th week. The combination analysis of metabolomics and proteomics of liver tissues was firstly performed to discover the candidate targets and potential molecular pathways involved in H₂S mitigating the NAFLD.

KEY FINDINGS

Compared with NaCl, H₂S relieved NAFLD by reducing liver weight, body weight and lipid accumulation in liver, and improving liver pathology and serum biochemical parameters. There were 40 overlapping metabolites in the intersection analysis between comparative analysis of HFD + NaCl vs NFD and HFD + NaHS vs HFD + NaCl based on liver metabolomics. Moreover, a total of 58 proteins were obtained whose changes were reversed after treatment with H₂S. A combined analysis of liver metabolomics and proteomics was then conducted, revealing 8 shared molecular pathways, as well as the enrichment of unsaturated fatty acids. In addition, Plin2 may also be a potential target of H₂S via the regulation of lipid droplet degradation in alleviating NAFLD.

SIGNIFICANCE

We performed the first study combining metabolomics and proteomics to explore the mechanisms behind the alleviation of NAFLD by H₂S. Our results not only provide evidence that H₂S alleviates NAFLD but also reveals its possible molecular mechanisms and targets.

Management of nonalcoholic fatty liver disease in the Middle East

The prevalence of nonalcoholic fatty liver disease (NAFLD) in the Middle East is increasing in parallel to an increase in the prevalence of associated risk factors such as obesity, metabolic syndrome, and type 2 diabetes mellitus. About 20% to 30% of the patients progress to develop nonalcoholic steatohepatitis (NASH), a histological subtype of NAFLD, with features of hepatocyte injury such as hepatocyte ballooning. NASH can progress to fibrosis, cirrhosis, and even hepatocellular carcinoma. NAFLD thus causes a substantial burden on healthcare systems and it is imperative that appropriate strategies are discussed at a regional level to facilitate effective management tailored to the needs of the region. To fulfil this unmet need, expert gastroenterologists, hepatologists, and endocrinologists from the region came together in three advisory board meetings that were conducted in Saudi Arabia, United Arab Emirates, and Kuwait, to discuss current local challenges in NAFLD screening and diagnosis, and the different available management options. The experts discussed the disease burden of NAFLD/NASH in the Middle East; screening, diagnosis, and referral patterns in NAFLD; and available treatment options for NAFLD and NASH. This paper summarizes the discussions and opinion of the expert panel on the management of NAFLD/NASH and also presents an extensive literature review on the topic.

Liver transplantation and cardiac illness: Current evidences and future directions

Contraindications to liver transplantation are gradually narrowing. Cardiac illness and chronic liver disease may manifest independently or may be superimposed on each other due to shared pathophysiology. Cardiac surgery involving the cardiopulmonary bypass in patients with Child-Pugh Class C liver disease is associated with a high risk of perioperative morbidity and mortality. Liver transplantation involves hemodynamic perturbations, volume shifts, coagulation abnormalities, electrolyte disturbances, and hypothermia, which may prove fatal in patients with cardiac illness depending upon the severity. Additionally, cardiovascular complications are the major cause of adverse postoperative outcomes after liver transplantation even in the absence of cardiac pathologies. Clinical decision-making has remained an unsettled issue in these clinical scenarios. The absence of randomized clinical studies has further crippled our endeavours for a consensus on the management of patients with end-stage liver disease with cardiac illness. This review seeks to address this complex clinical setting by gathering information from published literature. The management algorithm in this review may facilitate clinical decision making and augur future research.

Proteomic analysis to identify differentially expressed proteins between subjects with metabolic healthy obesity and non-alcoholic fatty liver disease

Obese subjects with non-alcoholic fatty liver disease (NAFLD) and considered metabolically healthy have not been well differentiated. In this study, obese subjects were divided into metabolic healthy obesity (MHO) and NAFLD groups. Liver tissues were sampled from these two types of subjects undergoing bariatric surgery, and proteins in the liver tissues that expressed differently between the two groups of subjects were identified by Tandem Mass Tags (TMT) assay. Compared with the MHO group, 132 proteins were found to be upregulated and 84 proteins were found to be downregulated (mainly localized in mitochondria) in NAFLD group. The KEGG pathway analysis showed that significantly upregulated metabolic pathways include PPAR signaling, ECM-receptor interaction and oxidative phosphorylation was significantly downregulated. The GO analysis revealed that upregulated proteins were involved in extracellular structure organization, extracellular matrix organization and downregulated proteins took part in the oxidation-reduction process and so on. FBLN5 and DHRS2 were further validated by Western blot, immunohistochemistry and ELISA. All results demonstrate that FBLN5 expression was significantly upregulated but DHRS2 was significantly downregulated. SIGNIFICANCE: The variation between MHO and NAFLD was studied by mass spectroscopy to evaluate the mechanism with which MHO subjects resist the harmful effects induced by obesity.

FGF19 and FGF21 for the Treatment of NASH-Two Sides of the Same Coin? Differential and Overlapping Effects of FGF19 and FGF21 From Mice to Human

FGF19 and FGF21 analogues are currently in clinical development for the potential treatment of NASH. In Phase 2 clinical trials analogues of FGF19 and FGF21 decrease hepatic steatosis with up to 70% (MRI-PDFF) after 12 weeks and as early as 12-16 weeks of treatment an improvement in NASH resolution and fibrosis has been observed. Therefore, this class of compounds is currently of great interest in the field of NASH. FGF19 and FGF21 belong to the endocrine FGF19 subfamily and both require the co-receptor beta-klotho for binding and signalling through the FGF receptors. FGF19 is expressed in the ileal enterocytes and is released into the enterohepatic circulation in response to bile acids stimuli and in the liver FGF19 inhibits hepatic bile acids synthesis by transcriptional regulation of Cyp7A1, which is the rate limiting enzyme. FGF21 is, on the other hand, highly expressed in the liver and is released in response to high glucose, high free-fatty acids and low amino-acid supply and regulates energy, glucose and lipid homeostasis by actions in the CNS and in the adipose tissue. FGF19 and FGF21 are differentially expressed, have distinct target tissues and separate physiological functions. It is therefore of peculiar interest to understand why treatment with both FGF19 and FGF21 analogues have strong beneficial effects on NASH parameters in mice and human and whether the mode of action is overlapping This review will highlight the physiological and pharmacological effects of FGF19 and FGF21. The potential mode of action behind the anti-steatotic, anti-inflammatory and anti-fibrotic effects of FGF19 and FGF21 will be discussed. Finally, development of drugs is always a risk benefit analysis and the human relevance of adverse effects observed in pre-clinical species as well as findings in humans will be discussed. The aim is to provide a comprehensive overview of the current understanding of this drug class for the potential treatment of NASH.

The impact of hepatitis B virus infection status on the prevalence of nonalcoholic fatty liver disease: A population-based study

BACKGROUND

We aimed to explore the impact of hepatitis B virus (HBV) infection on the prevalence of nonalcoholic fatty liver disease (NAFLD) based on clinical big data.

METHODS

Data were collected from the health examination center of the First Affiliated Hospital of Fujian Medical University. Univariate and multivariate analysis were applied to investigate the relationship between HBV and NAFLD.

RESULTS

A total of 14 452 patients were included, with an average age of 43.84 ± 13.03 years. Cases of HBV current infection, past infection, and noninfection were 21 102 110 (14.6%), 90 039 003 (62.3%), and 33 393 339 (23.1%), respectively. The prevalence of NAFLD was significantly lower in the current infection group (29.9%) than in the past infection group (35.8%) and noninfection group (31.9%) (P < .001). After adjusting for age, the prevalence of NAFLD in the current infection group remained the lowest across all of the age groups. Multivariate analysis showed that current infection was at a lower risk of NAFLD (odds ratio [OR] = 0.717, 95% CI: 0.608-0.846), whereas past infection had no effect on NAFLD.

CONCLUSIONS

Current HBV infection may lower the risk of NAFLD. This effect becomes insignificant when the patient is no longer infected.

Drug-induced liver steatosis in patients with HIV infection

Drug-induced liver injury (DILI) due to the use of prescription and non-prescription medication by HIV-positive and HIV-negative patients is one of the main causes of acute liver failure and transplantation in Western countries and, although rare, has to be considered a serious problem because of its unforeseeable nature and possibly fatal course. Drug-induced steatosis (DIS) and steatohepatitis (DISH) are infrequent but well-documented types of DILI. Although a number of commonly used drugs are associated with steatosis, it is not always easy to identify them as causative agents because of the weak temporal relationship between the administration of the drug and the clinical event, the lack of a confirmatory re-challenge, and the high prevalence of non-alcoholic fatty liver disease (NAFLD) in the general population, which often makes it difficult to make a differential diagnosis of DIS and DISH. The scenario is even more complex in HIV-positive patients not only because of the underlying disease, but also because the various anti-retroviral regimens have different effects on liver steatosis. Given the high prevalence of liver steatosis in HIV-positive patients and the increasing use of drugs associated with a potential steatotic risk, the identification of clinical signs suggesting liver damage should help to avoid the possible misdiagnosis of "primary" NAFLD in a patient with DIS or DISH. This review will therefore initially concentrate on the current diagnostic criteria for DIS/DISH and their differential diagnosis from NAFLD. Subsequently, it will consider the different clinical manifestations of iatrogenic liver steatosis in detail, with specific reference to HIV-positive patients. Finally, the last part of the review will be dedicated to the possible effects of liver steatosis on the bioavailability of antiretroviral and other drugs.

2, 3, 4', 5-tetrahydroxystilbene-2-0-β-d Glycoside Attenuates Age- and Diet-Associated Non-Alcoholic Steatohepatitis and Atherosclerosis in LDL Receptor Knockout Mice and Its Possible Mechanisms

The compound, 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (TSG), a primary bioactive polyphenolic component of Polygonum multiflorum exerts numerous pharmacological activities. However, its protective effect against non-alcoholic steatohepatitis (NASH), in the context of metabolic syndrome, remains poorly understood. The aim of the present study is to evaluate the effects of TSG treatment on middle-aged (12-mo-old) male LDLr^-/- mice, which were fed a high fat diet for 12 weeks to induce metabolic syndrome and NASH. At the end of the experiment, the blood samples of mice were collected for determination of metabolic parameters. Liver and aorta tissues were collected for analysis, such as histology, immunofluorescence, hepatic lipid content, real-time PCR, and western blot. Our data show that TSG treatment improved the different aspects of NASH (steatosis, inflammation, and fibrosis) and atherosclerosis, as well as some of the metabolic basal characteristics. These modulatory effects of TSG are mediated, at least in part, through regulating key regulators of lipid metabolism (SREBP1c, PPARα and their target genes, ABCG5 and CYP7A1), inflammation (CD68, TNF-α, IL-6 and ICAM), fibrosis (α-SMA and TNFβ) and oxidative stress (NADPH-oxidase 2/4, CYP2E1 and antioxidant enzymes). These results suggest that TSG may be a promising candidate for preventing and treating the progression of NASH.

The Mexican consensus on nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects nearly one third of the population worldwide. Mexico is one of the countries whose population has several risk factors for the disease and its prevalence could surpass 50%. If immediate action is not taken to counteract what is now considered a national health problem, the medium-term panorama will be very bleak. This serious situation prompted the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Hepatología to produce the Mexican Consensus on Fatty Liver Disease. It is an up-to-date and detailed review of the epidemiology, pathophysiology, clinical forms, diagnosis, and treatment of the disease, whose aim is to provide the Mexican physician with a useful tool for the prevention and management of nonalcoholic fatty liver disease.

Portal lymphadenopathy predicts non-alcoholic steatohepatitis and advanced fibrosis in non-alcoholic fatty liver disease

Background and aim

The progression of non-alcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH) is believed to be the driver for future development of fibrosis and cirrhosis. Nevertheless, there remains a clear deficit in non-invasive methods for the diagnosis of NASH. The aim of the present study was to evaluate the prevalence of portal lymphadenopathy (PL) in biopsy- proven NAFLD patients and to determine whether PL correlates with NAFLD stage and severity.

Methods

A retrospective study included biopsy-proven NAFLD patients with up to date (within one year) abdominal imaging by computed tomography (CT) and/or magnetic resonance imaging (MRI). Patients were clustered into three groups based on their NAFLD Activity Score (NAS): NAS1-2 (mild), NAS3-4 (moderate) and NAS≥5 (advanced). We Assessed for association between PL and other clinical and laboratory findings with NAS, NAS components and fibrosis.

Results

Seventy-five patients with NAFLD and no other competing etiologies for liver diseases or PL were included. The mean age was 50.7±14.84 years with male predominance (N = 47, 62.7%). Twenty-five (33.3%), 37 (49.3%) and 13 (17.3%) patients had mild, moderate and advanced NAS, respectively. PL significantly correlated with advanced NAS ≥ 5 (Fisher’s (F) 9.5, P = 0.009). Correlation was driven mainly by a link to hepatocytes ballooning (F of 5.9, P = 0.043). In addition, PL significantly correlated with portal inflammation (F 4.29, P = 0.038). As for hepatic fibrosis, the F test wasn’t significant, though spearman’s coefficient (SC) was significant (0.277, P = 0.012). On multivariate analysis, PL was identified as a sole predictor of advanced NAS score (Odds ratio of 2.68, P = 0.002). Incorporation of PL into noninvasive fibrosis scores improved their diagnostic yield.

Conclusion

PL predicts severity of NAFLD. Its presence may serve as a novel radiological marker for NAFLD/NASH differentiation and disease progression.

c-Met Signaling Protects from Nonalcoholic Steatohepatitis- (NASH-) Induced Fibrosis in Different Liver Cell Types

Nonalcoholic steatohepatitis (NASH) is the most common chronic, progressive liver disease in Western countries. The significance of cellular interactions of the HGF/c-Met axis in different liver cell subtypes and its relation to the oxidative stress response remains unclear so far. Hence, the present study is aimed at investigating the role of c-Met and the interaction with the oxidative stress response during NASH development in mice and humans. Conditional c-Met knockout (KO) lines (LysCre for Kupffer cells/macrophages, GFAPCre for α-SMA⁺ and CK19⁺ cells and MxCre for bone marrow-derived immune cells) were fed chow and either methionine-choline-deficient diet (MCD) for 4 weeks or high-fat diet (HFD) for 24 weeks. Mice lacking c-Met either in Kupffer cells, α-SMA⁺ and CK19⁺ cells, or bone marrow-derived immune cells displayed earlier and faster progressing steatohepatitis during dietary treatments. Severe fatty liver degeneration and histomorphological changes were accompanied by an increased infiltration of immune cells and a significant upregulation of inflammatory cytokine expression reflecting an earlier initiation of steatohepatitis development. In addition, animals with a cell-type-specific deletion of c-Met exhibited a strong generation of reactive oxygen species (ROS) by dihydroethidium (hydroethidine) (DHE) staining showing a significant increase in the oxidative stress response especially in LysCre/c-Met^mut and MxCre/c-Met^mut animals. All these changes finally lead to earlier and stronger fibrosis progression with strong accumulation of collagen within liver tissue of mice deficient for c-Met in different liver cell types. The HGF/c-Met signaling pathway prevents from steatosis development and has a protective function in the progression to steatohepatitis and fibrosis. It conveys an antifibrotic role independent on which cell type c-Met is missing (Kupffer cells/macrophages, α-SMA⁺ and CK19⁺ cells, or bone marrow-derived immune cells). These results highlight a global protective capacity of c-Met in NASH development and progression.

Zinc alpha2 glycoprotein protects against obesity-induced hepatic steatosis

BACKGROUND/AIM

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, impaired insulin sensitivity, and chronic low-grade inflammation. Our previous studies indicated that zinc alpha2 glycoprotein (ZAG) alleviates palmitate (PA)-induced intracellular lipid accumulation in hepatocytes. This study is to further characterize the roles of ZAG on the development of hepatic steatosis, insulin resistance (IR), and inflammation.

METHODS

ZAG protein levels in the livers of NAFLD patients, high-fat diet (HFD)-induced or genetically (ob/ob) induced obese mice, and in PA-treated hepatocytes were determined by western blotting. C57BL/6J mice injected with an adenovirus expressing ZAG were fed HFD for indicated time to induce hepatic steatosis, IR, and inflammation, and then biomedical, histological, and metabolic analyses were conducted to identify pathologic alterations in these mice. The molecular mechanisms underlying ZAG-regulated hepatic steatosis were further explored and verified in mice and hepatocytes.

RESULTS

ZAG expression was decreased in NAFLD patient liver biopsy samples, obese mice livers, and PA-treated hepatocytes. Simultaneously, ZAG overexpression alleviated intracellular lipid accumulation via upregulating adiponectin and lipolytic genes (FXR, PPARα, etc.) while downregulating lipogenic genes (SREBP-1c, LXR, etc.) in obese mice as well as in cultured hepatocytes. ZAG improved insulin sensitivity and glucose tolerance via activation of IRS/AKT signaling. Moreover, ZAG significantly inhibited NF-ĸB/JNK signaling and thus resulting in suppression of obesity-associated inflammatory response in hepatocytes.

CONCLUSIONS

Our results revealed that ZAG could protect against NAFLD by ameliorating hepatic steatosis, IR, and inflammation.