Vibration-Controlled Transient Elastography Scores to Predict Liver-Related Events in Steatotic Liver Disease

Importance Metabolic dysfunction–associated steatotic liver disease (MASLD) is currently the most common chronic liver disease worldwide. It is important to develop noninvasive tests to assess the disease severity and prognosis.Objective To study the prognostic implications of baseline levels and dynamic changes of the vibration-controlled transient elastography (VCTE)–based scores developed for the diagnosis of advanced fibrosis (Agile 3+) and cirrhosis (Agile 4) in patients with MASLD.Design, Setting, and Participants This cohort study included data from a natural history cohort of patients with MASLD who underwent VCTE examination at 16 tertiary referral centers in the US, Europe, and Asia from February 2004 to January 2023, of which the data were collected prospectively at 14 centers. Eligible patients were adults aged at least 18 years with hepatic steatosis diagnosed by histologic methods (steatosis in ≥5% of hepatocytes) or imaging studies (ultrasonography, computed tomography or magnetic resonance imaging, or controlled attenuation parameter ≥248 dB/m by VCTE).Main Outcomes and Measures The primary outcome was liver-related events (LREs), defined as hepatocellular carcinoma or hepatic decompensation (ascites, variceal hemorrhage, hepatic encephalopathy, or hepatorenal syndrome), liver transplant, and liver-related deaths. The Agile scores were compared with histologic and 8 other noninvasive tests.Results A total of 16 603 patients underwent VCTE examination at baseline (mean [SD] age, 52.5 [13.7] years; 9600 [57.8%] were male). At a median follow-up of 51.7 (IQR, 25.2-85.2) months, 316 patients (1.9%) developed LREs. Both Agile 3+ and Agile 4 scores classified fewer patients between the low and high cutoffs than most fibrosis scores and achieved the highest discriminatory power in predicting LREs (integrated area under the time-dependent receiver-operating characteristic curve, 0.89). A total of 10 920 patients (65.8%) had repeated VCTE examination at a median interval of 15 (IQR, 11.3-27.7) months and were included in the serial analysis. A total of 81.9% of patients (7208 of 8810) had stable Agile 3+ scores and 92.6% of patients (8163 of 8810) had stable Agile 4 scores (same risk categories at both assessments). The incidence of LREs was 0.6 per 1000 person-years in patients with persistently low Agile 3+ scores and 30.1 per 1000 person-years in patients with persistently high Agile 3+ scores. In patients with high Agile 3+ score at baseline, a decrease in the score by more than 20% was associated with substantial reduction in the risk of LREs. A similar trend was observed for the Agile 4 score, although it missed more LREs in the low-risk group.Conclusions and Relevance Findings of this study suggest that single or serial Agile scores are highly accurate in predicting LREs in patients with MASLD, making them suitable alternatives to liver biopsy in routine clinical practice and in phase 2b and 3 clinical trials for steatohepatitis

Inhibition of ATG3 ameliorates liver steatosis by increasing mitochondrial function

Non-alcoholic fatty liver disease (NAFLD) is a major health threat in both developed and developing countries and is a precursor of the more advanced liver diseases, including non-alcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. Currently, understanding the multiple and complex molecular pathways implicated in NAFLD onset and progression is a major priority. The transcription factor p63, which belongs to a family comprising p53, p63, and p73,1 is one of many factors that contributes to the development of liver steatosis. The role of p63 as a tumor suppressor and in cell maintenance and renewal is well studied, but we have recently reported that it is also relevant in the control of lipid metabolism.2 p63 encodes multiple isoforms that can be grouped into 2 categories; isoforms with an acidic transactivation domain (TA) and those without this domain (domain negative). The TAp63α isoform is elevated in the liver of animal models of NAFLD as well as in liver biopsies from obese patients with NAFLD. Furthermore, downregulation of p63α in the liver attenuates liver steatosis in diet-induced obese (DIO) mice, while the activation of TAp63α increases hepatic fat content, mediated by the activation of IKKβ and endoplasmic reticulum stress.2 A specialized form of autophagy that degrades lipid droplets, termed “lipophagy”, is a major pathway of lipid mobilization in hepatocytes. Lipophagy is elevated in hepatoma cells upon exposure to free fatty acids,3 and reduces the fatty acid load in mouse hepatocytes.4 Its impairment has been associated with the development of fatty liver and insulin resistance3,5; in contrast, the autophagic flux is increased during the activation of hepatic stellate cells.6 In the present study, we used an unbiased proteomics approach to gain insight into novel proteins modulating lipid metabolism in the liver of mice with genetic knockdown or overexpression of TAp63α. We found that autophagy-related gene 3 (ATG3) was upregulated by TAp63α activation and downregulated after p63α inhibition. ATG3 is elevated in several animal models of NAFLD and in the liver of patients with NAFLD. Genetic overexpression of ATG3 increased the lipid load in hepatocytes, while its repression alleviated TAp63α- and diet-induced steatosis. ATG3 exerted its role in lipid metabolism by regulating SIRT1 and mitochondrial function. Collectively, these findings identify ATG3 as a novel factor implicated in the development of steatosisThis work has been supported by grants from FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (PA: RTI2018-095134-B-100; DS and LH: SAF2017-83813-C3-1-R; MLMC: RTC2019-007125-1; CD: BFU2017-87721; ML: RTI2018–101840-B-I00; GS; PID2019-104399RB-I00; RN: RTI2018-099413-B-I00 and RED2018-102379-T; MLMC: SAF2017-87301-R; TCD: RTI2018-096759-A-100), FEDER/Instituto de Salud Carlos III (AGR: PI19/00123), Xunta de Galicia (ML: 2016-PG068; RN: 2015-CP080 and 2016-PG057), Fundación BBVA (RN, GS and MLM), Proyectos Investigación en Salud (MLMC: DTS20/00138), Sistema Universitario Vasco (PA: IT971-16); Fundación Atresmedia (ML and RN), Fundación La Caixa (M.L., R.N. and M.C.), Gilead Sciences International Research Scholars Program in Liver Disease (MVR), Marató TV3 Foundation (DS: 201627), Government of Catalonia (DS: 2017SGR278) and European Foundation for the Study of Diabetes (RN and GS). This research also received funding from the European Community’s H2020 Framework Programme (ERC Synergy Grant-2019-WATCH- 810331, to RN, VP and MS). Centro de Investigación Biomédica en Red (CIBER) de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Hepáticas y Digestivas (CIBERehd) and CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem). CIBERobn, CIBERehd and CIBERdem are initiatives of the Instituto de Salud Carlos III (ISCIII) of Spain which is supported by FEDER funds. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644)S

Definite and indeterminate nonalcoholic steatohepatitis share similar clinical features and prognosis : A longitudinal study of 1893 biopsy-proven nonalcoholic fatty liver disease subjects

Altres ajuts: Consejería de Salud de la Junta de Andalucía (PI-0075-2014).Background and Aim: Histological score systems may not fully capture the essential nonalcoholic steatohepatitis (NASH) features, which is one of the leading causes of screening failure in clinical trials. We assessed the NASH distribution and its components across the fibrosis stages and their impact on the prognosis and their relationship with the concept of metabolic-associated fatty liver disease (MAFLD). Methods: Spanish multicenter study including 1893 biopsy-proven nonalcoholic fatty liver disease (NAFLD) patients from HEPAmet registry. NASH was diagnosed by NAS score ≥4 (including steatosis, ballooning and lobular inflammation) and fibrosis by Kleiner score. The presence of MAFLD was determined. Progression to cirrhosis, first episode of decompensated cirrhosis and death were collected during the follow-up (4.7 ± 3.8 years). Results: Fibrosis was F0 34.3% (649/1893), F1 27% (511/1893), F2 16.5% (312/1893), F3 15% (284/1893) and F4 7.2% (137/1893). NASH diagnosis 51.9% (982/1893), and its individual components (severe steatosis, ballooning and lobular inflammation), increased from F0 (33.6%) to F2 (68.6%), and decreased significantly in F4 patients (51.8%) (P =.0001). More than 70% of non-NASH patients showed some inflammatory activity (ballooning or lobular inflammation), showing a similar MAFLD rate than NASH (96.2% [945/982] vs. 95.2% [535/562]) and significantly higher than nonalcoholic fatty liver (NAFL) subjects (89.1% [311/349]) (P <.0001). Progression to cirrhosis was similar between NASH (9.5% [51/539]) and indeterminate NASH (7.9% [25/316]), and higher than steatosis (5% [14/263]) (logRank 8.417; P =.015). Death and decompensated cirrhosis were similar between these. Conclusions: The prevalence of steatohepatitis decreased in advanced liver disease. However, most of these patients showed some inflammatory activity histologically and had metabolic disturbances. These findings should be considered in clinical trials whose main aim is to prevent cirrhosis progression and complications, liver transplant and death

Inhibition of ATG3 ameliorates liver steatosis by increasing mitochondrial function

Background & aims: Autophagy-related gene 3 (ATG3) is an enzyme mainly known for its actions in the LC3 lipidation process, which is essential for autophagy. Whether ATG3 plays a role in lipid metabolism or contributes to non-alcoholic fatty liver disease (NAFLD) remains unknown. Methods: By performing proteomic analysis on livers from mice with genetic manipulation of hepatic p63, a regulator of fatty acid metabolism, we identified ATG3 as a new target downstream of p63. ATG3 was evaluated in liver samples from patients with NAFLD. Further, genetic manipulation of ATG3 was performed in human hepatocyte cell lines, primary hepatocytes and in the livers of mice. Results: ATG3 expression is induced in the liver of animal models and patients with NAFLD (both steatosis and non-alcoholic steatohepatitis) compared with those without liver disease. Moreover, genetic knockdown of ATG3 in mice and human hepatocytes ameliorates p63- and diet-induced steatosis, while its overexpression increases the lipid load in hepatocytes. The inhibition of hepatic ATG3 improves fatty acid metabolism by reducing c-Jun N-terminal protein kinase 1 (JNK1), which increases sirtuin 1 (SIRT1), carnitine palmitoyltransferase 1a (CPT1a), and mitochondrial function. Hepatic knockdown of SIRT1 and CPT1a blunts the effects of ATG3 on mitochondrial activity. Unexpectedly, these effects are independent of an autophagic action. Conclusions: Collectively, these findings indicate that ATG3 is a novel protein implicated in the development of steatosis. Lay summary: We show that autophagy-related gene 3 (ATG3) contributes to the progression of non-alcoholic fatty liver disease in humans and mice. Hepatic knockdown of ATG3 ameliorates the development of NAFLD by stimulating mitochondrial function. Thus, ATG3 is an important factor implicated in steatosis. Keywords: ATG3; NAFLD; NASH; lipid metabolism; mitochondria; sirtuin 1