Aldehydes alter TGF-β signaling and induce obesity and cancer
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ABSTRACT: Obesity and fatty liver diseases-metabolic dysfunction-associated steatotic liver disease (MASLD and MASH) affect over a third of the global population and are exacerbated in individuals with reduced functional aldehyde dehydrogenase 2 (ALDH2), observed in approximately 560 million people. Current treatment to prevent disease progression to cancer remains inadequate, requiring innovative approaches. We observe that Aldh2-/- and Aldh2-/-Sptbn1+/- (ASKO) mice develop phenotypes of human Metabolic Syndrome (MetS) and MASH with altered lipid metabolism and TGF-β signaling, leading to pro-fibrotic and pro-oncogenic phenotypes, which is restored to normal with siRNA to SPTBN1. Significantly, therapeutic inhibition of SPTBN1 blocks MASH and fibrosis in a human 3D MASH model. This study identifies SPTBN1 as a critical regulator of the functional phenotype of toxic aldehyde-induced MASH and a potential therapeutic target.
Project description:Metabolic dysfunction-associated steatotic liver disease (MASLD) embraces different conditions, including metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The landscape of cellular abnormalities occurring in the different stages of MASLD as well as the processes which drive MASLD evolution are not completely clarified. We used single cell RNAsequencing (scRNAseq) to unravel cellular heterogeneity affecting livers during the switching from simple steatosis towads MASH and and MASH-fibrosis.
Project description:Background & Aims Obesity is a major risk factor for metabolic associated steatotic liver disease (MASLD) which can progress from metabolic associated steatotic liver (MASL) to metabolic associated steatohepatitis (MASH). There are currently no effective and validated screening tools to stratify obese patients with a greater risk for MASH, independent of liver fibrosis, at a population level. We aimed to characterise the highly abundant and small protein plasma proteomes of worsening MASLD and overlay the liver-secreted proteome to generate a predictive model to stratify patients with and without MASH. Methods Venous blood and liver wedge biopsies were taken from 160 patients undergoing bariatric surgery. MASLD severity was assessed histologically. Liver biopsies from a subset of 96 patients were precision-cut and cultured to assess liver-secreted proteins. Proteomic analysis was performed using liquid chromatography-tandem mass spectrometry on the plasma and the incubation medium cutoff the liver slices. Results Current non-invasive scores failed to stratify MASH in our cohort. The top200 plasma proteome exhibited mild changes in patients with MASH compared to those with No pathology, while the SPEA approach identified substantial differences in plasma proteins of patients with MASH compared to those without MASH. Liver-secreted proteins were remodelled in MASH compared to MASL and individuals with No pathology. There were no significant changes in the liver-secreted proteins and plasma proteome when comparing MASL to those with No pathology. The APASHA model, comprised of APOF, PCSK9, AFM, and S100A6, HbA1c % and AZGP1 stratified MASH in the discovery (AUROC: 0.887, p<0.0001) and validation cohorts (AUROC:0.7673, p=0.0002) and outcompeted other non-invasive scores. Conclusions These proteomic investigations provide a detailed description of liver-secreted and plasma proteome with worsening MASLD. MASH remodels plasma and liver-secreted proteins. Plasma proteomics generated the APASHA model validated in two Australian bariatric cohorts. Further investigation is warranted to interrogate the utility of the APASHA model as a non-invasive risk prediction model in additional cohorts. Lay Summary: Metabolic-associated steatohepatitis (MASH), a more advanced form of metabolic-associated steatotic liver disease (MASLD), alters the levels of many proteins secreted by the liver and in the blood and those. The APASHA model, which is based on proteins that change in the blood or are secreted by the liver in cases of MASH, could potentially be developed into a simple blood test to predict MASH in high-risk groups.
Project description:Background & Aims Obesity is a major risk factor for metabolic associated steatotic liver disease (MASLD) which can progress from metabolic associated steatotic liver (MASL) to metabolic associated steatohepatitis (MASH). There are currently no effective and validated screening tools to stratify obese patients with a greater risk for MASH, independent of liver fibrosis, at a population level. We aimed to characterise the highly abundant and small protein plasma proteomes of worsening MASLD and overlay the liver-secreted proteome to generate a predictive model to stratify patients with and without MASH. Methods Venous blood and liver wedge biopsies were taken from 160 patients undergoing bariatric surgery. MASLD severity was assessed histologically. Liver biopsies from a subset of 96 patients were precision-cut and cultured to assess liver-secreted proteins. Proteomic analysis was performed using liquid chromatography-tandem mass spectrometry on the plasma and the incubation medium cutoff the liver slices. Results Current non-invasive scores failed to stratify MASH in our cohort. The top200 plasma proteome exhibited mild changes in patients with MASH compared to those with No pathology, while the SPEA approach identified substantial differences in plasma proteins of patients with MASH compared to those without MASH. Liver-secreted proteins were remodelled in MASH compared to MASL and individuals with No pathology. There were no significant changes in the liver-secreted proteins and plasma proteome when comparing MASL to those with No pathology. The APASHA model, comprised of APOF, PCSK9, AFM, and S100A6, HbA1c % and AZGP1 stratified MASH in the discovery (AUROC: 0.887, p<0.0001) and validation cohorts (AUROC:0.7673, p=0.0002) and outcompeted other non-invasive scores. Conclusions These proteomic investigations provide a detailed description of liver-secreted and plasma proteome with worsening MASLD. MASH remodels plasma and liver-secreted proteins. Plasma proteomics generated the APASHA model validated in two Australian bariatric cohorts. Further investigation is warranted to interrogate the utility of the APASHA model as a non-invasive risk prediction model in additional cohorts.
Project description:As metabolic dysfunction-associated steatotic liver disease (MASLD) frequently co_x0002_occurs in patients with chronic hepatitis B (CHB), the interplay between these two common liver conditions remains largely unexplored. A recent study suggest that MASH comorbidity can reduce intrahepatic interferon pathway activity and macrophage gene signatures in HBeAg_x0002_negative chronic HBV (ENEG) patients, potentially contributing to persistent infection and fibrosis. However, it remains unclear whether this phenomenon also occurs in MASLD with CHB patients.
Project description:Reliable non-invasive tools to diagnose at risk metabolic dysfunction-associated steatohepatitis (MASH) are urgently needed to improve management. We developed a risk stratification score incorporating proteomics-derived serum markers with clinical variables to identify high risk MASH patients (NAFLD Activity Score (NAS) >4 and fibrosis score >2). In this three-phase proteomic study of biopsy-proven metabolic dysfunction-associated steatotic fatty liver disease (MASLD), we first developed a multi-protein predictor for discriminating NAS>4 based on SOMAscan proteomics quantifying 1,305 serum proteins from 57 US patients. Four key predictor proteins were verified by ELISA in the expanded US cohort (N=168), and enhanced by adding clinical variables to create the 9-feature MASH Dx Score which predicted MASH and also high risk MASH (F2+). The MASH Dx Score was validated in two independent, external cohorts from Germany (N=139) and Brazil (N=177). The discovery phase identified a 6-protein classifier that achieved an AUC of 0.93 for identifying MASH. Significant elevation of four proteins (THBS2, GDF15, SELE, IGFBP7) was verified by ELISA in the expanded discovery and independently in the two external cohorts. MASH Dx Score incorporated these proteins with established MASH risk factors (age, BMI, ALT, diabetes, hypertension) to achieve good discrimination between MASH and MASLD without MASH (AUC:0.87- discovery; 0.83- pooled external validation cohorts), with similar performance when evaluating high risk MASH F2-4 (vs. MASH F0-1 and MASLD without MASH). The MASH Dx Score offers the first reliable non-invasive approach combining novel, biologically plausible ELISA-based fibrosis markers and clinical parameters to detect high risk MASH in patient cohorts from the US, Brasil and Europe.
Project description:Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are still needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA stability post-transcriptionally. N-acetyltransferase 10 (NAT10), the sole enzyme catalyzing mRNA acetylation, has not been fully explored in human diseases, especially in MASLD and MASH. In the current study, abundant RNA acetylation was found in lipid metabolism-related genes in the livers of leptin receptor-deficient (db/db) mice. Besides, hepatic NAT10 expression is significantly increased in multiple mouse models of MASLD and MASH. NAT10 expression is also elevated in patients with MASLD and positively correlated with clinical characteristics. Genetic NAT10 knockdown protects against diet-induced hepatic steatosis and steatohepatitis in mice, while its overexpression exacerbates steatosis. Mechanistically, NAT10 could bind to Srebp-1c mRNA to promote its stability and expression, thereby upregulating lipogenic enzymes. In addition, the translational significance of our findings is that treatment of Remodelin, an NAT10 inhibitor, could improve liver steatosis and dyslipidemia in a preclinical mouse model. Together, these findings highlight the significance of ac4C modification and NAT10 in MASLD and MASH, offering a potential therapeutic target for disease treatment.
Project description:Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are still needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA stability post-transcriptionally. N-acetyltransferase 10 (NAT10), the sole enzyme catalyzing mRNA acetylation, has not been fully explored in human diseases, especially in MASLD and MASH. In the current study, abundant RNA acetylation was found in lipid metabolism-related genes in the livers of leptin receptor-deficient (db/db) mice. Besides, hepatic NAT10 expression is significantly increased in multiple mouse models of MASLD and MASH. NAT10 expression is also elevated in patients with MASLD and positively correlated with clinical characteristics. Genetic NAT10 knockdown protects against diet-induced hepatic steatosis and steatohepatitis in mice, while its overexpression exacerbates steatosis. Mechanistically, NAT10 could bind to Srebp-1c mRNA to promote its stability and expression, thereby upregulating lipogenic enzymes. In addition, the translational significance of our findings is that treatment of Remodelin, an NAT10 inhibitor, could improve liver steatosis and dyslipidemia in a preclinical mouse model. Together, these findings highlight the significance of ac4C modification and NAT10 in MASLD and MASH, offering a potential therapeutic target for disease treatment.
Project description:The lack of an appropriate preclinical model of metabolic dysfunction-associated steatotic liver disease (MASLD) that recapitulates the whole disease spectrum impedes exploration of disease pathophysiology and the development of effective treatment strategies. Considering the fact that MASLD patients accompanying type 2 diabetes mellitus (T2DM) have high risk of developing metabolic dysfunction-associated steatohepatitis (MASH), advanced fibrosis, and HCC, we treated low-dose streptozotocin (STZ; 40 mg/kg) for 5 consecutive days and subsequently fed a high-fat diet (HFD) to male C57BL/6J mice at 7 weeks of age (STZ+HFD). STZ+HFD mice gradually developed fatty liver, MASH, hepatic fibrosis, and hepatocellular carcinoma (HCC) in the context of metabolic dysfunction. In particular, from 20 weeks of age, MASH was evident, and from 32 weeks of age, advanced fibrosis was developed. At 38 weeks, a proportion of STZ+HFD mice developed HCC, which was subsequently observed in all mice up to 68 weeks of age. Furthermore, the hepatic transcriptomic features of STZ+HFD mice closely reflected those of obese patients with T2DM, MASH and MASLD-related HCC. Notably, dietary changes and tirzepatide administration alleviated MASH, hepatic fibrosis, and hepatic tumorigenesis in STZ+HFD mice. In conclusion, a murine model recapitulating the main histopathologic, transcriptomic, and metabolic alterations observed in MASLD patients with metabolic dysfunction was successfully established.
Project description:Background and aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) progresses from steatosis (Metabolic dysfunction-associated steatotic liver, MASL) to Metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis. Activation of Hepatic Stellate Cells (HSCs) into fibrogenic myofibroblasts plays a critical role in the pathogenesis of MASH liver fibrosis. Here we compared gene expression and chromatin accessibility profiles of human HSCs in NORMAL, MASL, and MASH livers at single cell resolution. Methods: 18 human livers were profiled using single-nucleus (sn) RNA-seq and snATAC-seq. High priority targets were identified and then tested in 2D human HSCs, 3D human liver spheroids, and HSC-specific gene knockout mice. Results: This study identified novel gene regulatory mechanisms underlying MASL- and MASH-associated HSC heterogeneity and outlined potential strategies for anti-fibrotic therapy. Specifically, MASH-enriched HSC-subcluster hA1, represented by highly fibrogenic population of myofibroblasts, served as a critical source of extracellular matrix protein (ECM) in MASH, and its activation was regulated via a cross-talk between lineage-specific (JUNB/AP1), cluster-specific (RUNX1/2) and signal-specific (FOXA1/2) transcription factors (TFs). Additionally, we identified a set of core genes (GAS7, SPON1, SERPINE1, LTBP2, KLF9, EFEMP1) that drive ECM production in hA1 HSCs. The pathological relevance of the selected hA1 targets, such as SERPINE1 and others, was demonstrated using siRNA-based HSC-specific gene knockdown or pharmacological inhibitor of SERPINE1 in 3D human MASH liver spheroids, and HSC-specific Serpine1 knockout mice with MASH. Conclusion: We identified potential targets for anti-fibrotic therapy of MASH in patients.
Project description:Background: Biomarkers for metabolic dysfunction-associated steatohepatitis (MASH) have been considered based on proteomic and lipidomic data from plasma and liver tissue without clinical benefits. This study evaluated proteomics-based plasma and liver tissue biomarkers collected simultaneously from patients with metabolic dysfunction-associated steatotic liver disease (MASLD).
Methods: Liver tissue samples and plasma samples were collected during liver biopsy for diagnosis. Untargeted proteomics was performed on 64 patients with MASLD.
Results: Twenty plasma proteins were up or downregulated in patients with MASH compared with those without MASH. The biomarkers utilizing the best combinations of these plasma proteins had an area under the receiver operating curve (AUROC) of 0.671 for detecting those with MASH compared with those without it. However, none of the 20 plasma proteins were represented among the significantly regulated liver tissue proteins in patients with MASH. Ten of them displayed a trend and relevance in liver tissue with MASLD progression. These ten plasma proteins had an AUROC of 0.793 for MASH identification and higher positive and negative predictive values.
Conclusion: The plasma and liver protein expressions of patients with MASH were not directly comparable. Plasma protein biomarkers that are also expressed in liver tissue can help improve MASH detection.