Preclinical models of non-alcoholic fatty liver disease Santhekadur, Prasanna K.; Kumar, Divya P.; Sanyal, Arun J.
Journal of hepatology,
February 2018, 2018-Feb, 2018-02-00, 20180201, Letnik:
68, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Non-alcoholic fatty liver disease (NAFLD) can manifest as non-alcoholic fatty liver (NAFL) or non-alcoholic steatohepatitis (NASH). NASH is often associated with progressive fibrosis which can lead ...to cirrhosis and hepatocellular carcinoma (HCC). NASH is increasing as an aetiology for end-stage liver disease as well as HCC. There are currently no approved therapies for NASH. A major barrier to development of therapeutics for NASH is the lack of preclinical models of disease that are appropriately validated to represent the biology and outcomes of human disease. Many in vitro and animal models have been developed. In vitro models do not fully capture the hepatic and extrahepatic milieu of human NASH and large animal models are expensive and logistically difficult to use. Therefore, there is considerable interest in the development and validation of mouse models for NAFLD, including NASH. Several models based on varying genetic or dietary manipulations have been developed. However, the majority do not recreate steatohepatitis, strictly defined as the presence of hepatocellular ballooning with or without Mallory-Denk bodies, accompanied by inflammation in the presence of macrovesicular steatosis. Others lack validation against human disease. Herein, we describe the best practices in development of mouse models of NASH. We further review existing models and the literature supporting their use as a surrogate for human disease. Finally, data on models to evaluate protective genes are discussed. It is hoped that this review will provide guidance for the interpretation of data derived from mouse models and also for the development and validation of newer models.
NAFLD is the most prevalent form of liver disease in the USA, affecting an estimated 30% of the population. The condition is associated with increased mortality related to cardiovascular disease, ...malignancy and liver disease. Identification of patients who might be at increased risk of adverse outcomes is critical as it is not feasible to screen all patients with suspected NAFLD. Patients with NASH, the progressive subtype of NAFLD, should be targeted for treatment, especially if they have concomitant fibrosis because such patients are more likely than those without fibrosis to have adverse outcomes. Treatment goals in patients with NAFLD vary depending on the disease stage owing to differential risk of progression and the particularities of an individual's comorbid disease. Lifestyle intervention is important for all patients irrespective of disease stage, but other therapies should be targeted to those most likely to benefit. In this Review, we highlight risk factors for disease progression and offer a stage-based treatment approach for patients with NAFLD.
Nonalcoholic fatty liver disease (NAFLD) is associated with increased cardiovascular and liver-related mortality. NAFLD is characterized by both triglyceride and free cholesterol (FC) accumulation ...without a corresponding increment in cholesterol esters. The aim of this study was to evaluate the expression of cholesterol metabolic genes in NAFLD and relate these to disease phenotype. NAFLD was associated with increased SREBP-2 maturation, HMG CoA reductase (HMGCR) expression and decreased phosphorylation of HMGCR. Cholesterol synthesis was increased as measured by the circulating desmosterol:cholesterol ratio. miR-34a, a microRNA increased in NAFLD, inhibited sirtuin-1 with downstream dephosphorylation of AMP kinase and HMGCR. Cholesterol ester hydrolase was increased while ACAT-2 remained unchanged. LDL receptor expression was significantly decreased and similar in NAFLD subjects on or off statins. HMGCR expression was correlated with FC, histologic severity of NAFLD and LDL-cholesterol. These data demonstrate dysregulated cholesterol metabolism in NAFLD which may contribute to disease severity and cardiovascular risks.
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► There is increased HMGCR and decreased LDL receptor expression in NAFLD ► HMGCR expression correlates with FC accumulation and histologic severity of NAFLD ► LDL-C varies directly with HMGCR and inversely with LDLR expression in NAFLD ► miR-34a dephosphorylates HMGCR and may increase cholesterol synthesis in NAFLD
Non‐alcoholic steatohepatitis (NASH) is the most common cause of liver disease in Western populations, and its prevalence is increasing rapidly. It is part of a multisystem disease affecting other ...organs such as the kidneys, heart and blood vessels, and is closely associated with the components of the metabolic syndrome. Physicians managing patients with NASH should not only focus on the management of NASH, but also on associated comorbidities in individual patients. The approaches to treatment of NASH include either limiting energy surplus alone, or in combination with targeting of downstream pathways of inflammation and fibrosis. In this mini‐review, we discuss the currently available treatment options for NASH, as well as those in late‐stage clinical trials. We discuss the challenges of managing these patients with a limited number of approved therapies, as well as managing advanced‐stage patients with NASH and cirrhosis. We also discuss the specific management of comorbidities in NASH patients, in particular diabetes, hypertension, dyslipidaemia and cardiovascular diseases. Finally, we present the screening protocols for both hepatocellular carcinoma and extrahepatic malignancies in these patients.
Non-alcoholic fatty liver disease (NAFLD) has emerged as a common cause of liver-related morbidity and mortality. Tackling this condition at a societal level will require a clear understanding of the ...burden of disease in the general population. However, a major limitation of such an assessment, particularly in a real-world setting, is the low rate of diagnosis of the condition, as recently identified by Alexander et al. (BMC Med 16:130, 2018). Therein, the likelihood that the condition is indeed underdiagnosed and the potential causes for such underdiagnosis are discussed. The authors underscore the need for physician education and for development of simple evaluation tools that are both robust and implementable in a primary care setting, along with effective therapeutics to overcome this apathy towards NAFLD. Importantly, there remains a need for additional data on the prevalence of non-alcoholic steatohepatitis, the more aggressive form of NAFLD, especially with progressive fibrosis, along with patient outcomes to inform health policy decisions related to screening, surveillance, and access to therapeutics.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Nonalcoholic fatty liver disease (NAFLD) is a global public health concern. Its natural history, the development of nonalcoholic steatohepatitis (NASH) and fibrosis, is highly variable, prone to ...endogenous (e.g., genetics, microbiota) and exogenous (e.g., nutrition, alcohol, physical activity) disease modifiers, and can fluctuate over time. The complexity of its pathophysiology is reflected by the multitude of pharmacological targets in development. NASH clinical trials have provided valuable insight that is applicable to future trial design. Endpoints for NASH have evolved over the past decade and will continue to be refined. Currently accepted endpoints for conditional approval include resolution of NASH without worsening of fibrosis and/or improvement in fibrosis without worsening of NASH by standardized evaluation of paired liver histology. In pediatric NASH, practical obstacles, pubertal hormonal changes, and stringent safety requirements mandate adaptations in trial design. In adult patients with NASH‐related cirrhosis, clinical events (e.g. decompensation, hepatocellular carcinoma, transplantation, death) are more prevalent and thereby are viable primary endpoints. Consideration of the natural fluctuation of disease, the clinical implication of the chosen primary endpoint, and factors that may affect placebo response will facilitate an accurate determination of efficacy of emerging therapeutics for NASH. Conclusion: The June 2018 American Association for the Study of Liver Diseases and European Association for the Study of the Liver joint workshop on NAFLD endpoints summarized important findings from ongoing and completed trials, defined the scientific evidence supporting distinct endpoints, and provided guidance for future trial design.
The clinical presentation and outcomes of non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma are unclear when compared with hepatocellular carcinoma due to other causes. We ...aimed to establish the prevalence, clinical features, surveillance rates, treatment allocation, and outcomes of NAFLD-related hepatocellular carcinoma.
In this systematic review and meta-analysis, we searched MEDLINE and Embase from inception until Jan 17, 2022, for articles in English that compared clinical features, and outcomes of NAFLD-related hepatocellular carcinoma versus hepatocellular carcinoma due to other causes. We included cross-sectional and longitudinal observational studies and excluded paediatric studies. Study-level data were extracted from the published reports. The primary outcomes were (1) the proportion of hepatocellular carcinoma secondary to NAFLD, (2) comparison of patient and tumour characteristics of NAFLD-related hepatocellular carcinoma versus other causes, and (3) comparison of surveillance, treatment allocation, and overall and disease-free survival outcomes of NAFLD-related versus non-NAFLD-related hepatocellular carcinoma. We analysed proportional data using a generalised linear mixed model. Pairwise meta-analysis was done to obtain odds ratio (OR) or mean difference, comparing NAFLD-related with non-NAFLD-related hepatocellular carcinoma. We evaluated survival outcomes using pooled analysis of hazard ratios.
Of 3631 records identified, 61 studies (done between January, 1980, and May, 2021; 94 636 patients) met inclusion criteria. Overall, the proportion of hepatocellular carcinoma cases secondary to NAFLD was 15·1% (95% CI 11·9–18·9). Patients with NAFLD-related hepatocellular carcinoma were older (p<0·0001), had higher BMI (p<0·0001), and were more likely to present with metabolic comorbidities (diabetes p<0·0001, hypertension p<0·0001, and hyperlipidaemia p<0·0001) or cardiovascular disease at presentation (p=0·0055) than patients with hepatocellular carcinoma due to other causes. They were also more likely to be non-cirrhotic (38·5%, 27·9–50·2 vs 14·6%, 8·7–23·4 for hepatocellular carcinoma due to other causes; p<0·0001). Patients with NAFLD-related hepatocellular carcinoma had larger tumour diameters (p=0·0087), were more likely to have uninodular lesions (p=0·0003), and had similar odds of Barcelona Clinic Liver Cancer stages, TNM stages, alpha fetoprotein concentration, and Eastern Cooperative Oncology Group (ECOG) performance status to patients with non-NAFLD-related hepatocellular carcinoma. A lower proportion of patients with NAFLD-related hepatocellular carcinoma underwent surveillance (32·8%, 12·0–63·7) than did patients with hepatocellular carcinoma due to other causes (55·7%, 24·0–83·3; p<0·0001). There were no significant differences in treatment allocation (curative therapy, palliative therapy, and best supportive care) between patients with NAFLD-related hepatocellular carcinoma and those with hepatocellular carcinoma due to other causes. Overall survival did not differ between the two groups (hazard ratio 1·05, 95% CI 0·92–1·20, p=0·43), but disease-free survival was longer for patients with NAFLD-related hepatocellular carcinoma (0·79, 0·63–0·99; p=0·044). There was substantial heterogeneity in most analyses (I2>75%), and all articles had low-to-moderate risk of bias.
NAFLD-related hepatocellular carcinoma is associated with a higher proportion of patients without cirrhosis and lower surveillance rates than hepatocellular carcinoma due to other causes. Surveillance strategies should be developed for patients with NAFLD without cirrhosis who are at high risk of developing hepatocellular carcinoma.
None.
Non-alcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, encompassing a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis, which can progress to ...cirrhosis. It has recently been recognised that NAFLD also occurs in individuals who are not obese, especially in Asian populations. In these patients, NAFLD manifests at lower overall body mass index thresholds in the presence of increased visceral adipose tissue. Currently, the principles of clinical management are similar to those in obese individuals, although, in specific regions and clinical situations, unique aetiologies of NAFLD must be treated specifically.
The future of hepatology Friedman, Scott L; Sanyal, Arun J
Hepatology (Baltimore, Md.),
2023-Aug-01, 2023-08-00, 20230801, Letnik:
78, Številka:
2
Journal Article
Recenzirano
The field of hepatology has made impressive progress over its ~75 years of existence. Advances in understanding liver function and its dysregulation in disease, genetic determinants of disease, ...antiviral therapy, and transplantation have transformed the lives of patients. However, there are still significant challenges that require ongoing creativity and discipline, particularly with the emergence of fatty liver diseases, as well as managing autoimmune disease, cancer, and liver disease in children. Diagnostic advances are urgently needed to accelerate risk stratification and efficient testing of new agents with greater precision in enriched populations. Integrated, holistic care models should be extended beyond liver cancer to diseases like NAFLD with systemic manifestations or extrahepatic comorbidities such as cardiovascular disease, diabetes, addiction, and depressive disorders. To meet the growing burden of asymptomatic liver disease, the workforce will need to be expanded by incorporating more advanced practice providers and educating other specialists. The training of future hepatologists will benefit from incorporating emerging skills in data management, artificial intelligence, and precision medicine. Continued investment in basic and translational science is crucial for further progress. The challenges ahead are significant, but with collective effort, the field of hepatology will continue to make progress and overcome obstacles.
Progression of nonalcoholic steatohepatitis (NASH) is incompletely characterized. We analyzed data on longitudinal changes in liver histology, hepatic venous pressure gradient (HVPG), and serum ...markers of fibrosis in 475 patients with NASH with bridging fibrosis (F3) or compensated cirrhosis (F4) enrolled in two phase 2b, placebo‐controlled trials of simtuzumab. The trials were terminated after 96 weeks because of lack of efficacy, so data from treatment groups were combined. Liver biopsies and HVPG measurements (only for patients with F4 fibrosis) were collected at screening and at weeks 48 and 96. Patients were assessed for Ishak fibrosis stage, hepatic collagen content and alpha‐smooth muscle actin (by morphometry), NAFLD Activity Score (NAS), and serum markers of fibrosis. Associations with progression to cirrhosis (in patients with F3 fibrosis) and liver‐related clinical events (in patients with F4 fibrosis) were determined. Progression to cirrhosis occurred in 22% (48/217) of F3 patients, and liver‐related clinical events occurred in 19% (50/258) of patients with cirrhosis. Factors significantly associated with progression to cirrhosis included higher baseline values of and greater increases in hepatic collagen content, level of alpha‐smooth muscle actin, and Enhanced Liver Fibrosis score. Similar factors, plus lack of fibrosis stage improvement (hazard ratio, 9.30; 95% confidence interval, 1.28‐67.37), higher HVPG at baseline, and greater increase in HVPG over time, were associated with an increased risk of liver‐related clinical events in patients with cirrhosis. Disease progression was not associated with the NAS at baseline or changes in NAS during treatment after adjustment for fibrosis stage. Conclusion: In patients with advanced fibrosis due to NASH, the primary determinant of clinical disease progression is fibrosis and its change over time.
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