Project description:Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive disease linked to conditions like fibrosis, cirrhosis, and liver cancer, often resulting in higher mortality rates, primarily due to cardiovascular events. While MASH is closely tied to metabolic syndrome, recent research underscores the importance of the gut-liver axis in its pathogenesis, an aspect less explored in human studies. To address this gap, duodenal epithelial organoids were generated from both MASH and healthy (controls) subjects. Organoid formation efficiency was similar between controls derived epithelial organoids (CDEOs) and MASH derived epithelial organoids (MDEOs) groups. Variability in growth patterns was observed, with MDEOs frequently exhibiting cystic spheroid morphology. MASH-derived organoids displayed altered homeostasis and digestive potential in the duodenal epithelium. Despite potential lineage bias, MDEOs retained their lipid metabolic capacity, possibly mediated by lipid oxidation in stem/progenitor cells. Notably, cell adhesion components were misexpressed in MASH-derived organoids, indicating significant intrinsic alterations in cell-cell adhesion potential compared to controls. However, MDEOs maintained transepithelial electric resistance and leak pathway integrity, indicating that the intestinal epithelial barrier remained functionally intact in MDEOs under tested conditions. This study sheds light on the intricate dynamics of duodenal epithelial alterations in MASH, highlighting potential therapeutic avenues for restoring intestinal homeostasis.
Project description:To elucidate the role of duodenal microenvironment in Common variable immunodeficiency pathogenesis (CVID), we sought to explore the transcriptome regulation in duodenal biopsies.
Project description:Excess cholesterol accumulation contributes to fibrogenesis in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis [NASH]), but how hepatic cholesterol metabolism becomes dysregulated in MASH is not completely understood. We show here that human fibrotic MASH livers have decreased EHBP1, a novel GWAS locus associated with LDL cholesterol, and that the EHBP1 rs10496099 T>C variant in MASH patients is associated with decreased hepatic EHBP1 expression and with augmented MASH fibrosis. Congruent with the human data, EHBP1 loss- and gain-of-function increases and decreases MASH fibrosis in mice, respectively. Mechanistic studies reveal that EHBP1 promotes sortilin (SORT1)-mediated PCSK9 secretion, leading to LDLR degradation, decreased LDL uptake, and reduced TAZ, a fibrogenic effector. At a cellular level, EHBP1 deficiency affects intracellular localization of retromer, a protein complex required for sortilin stabilization. Our novel therapeutic approach to stabilizing retromer is effective in mitigating MASH fibrosis. Moreover, we show that the TNFα/PPARα pathway suppresses EHBP1 in MASH. These data not only provide new mechanistic insight into the role of EHBP1 in cholesterol metabolism and MASH fibrosis by uncovering the interaction between EHBP1 and other cholesterol-related loci, including SORT1, PCSK9, and LDLR, but also elucidate a novel interplay between inflammation and EHBP1-mediated cholesterol metabolism.
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:Duodenal cancer is a leading cause of death in patients with FAP after colectomy. While cancer risk is up to 36% in Spigelman Stage IV patients, a significant proportion of cases occur in lower stage patients. Genome wide interrogation of APC-deficient mice revealed candidate biomarkers whose altered expression accompanied the evolution of small intestinal neoplasia. To date, no similar investigations have been pursued in FAP patients. In this study, a genome-wide transcriptional analysis of duodenal specimens from FAP patients was performed in order to describe changes occurring in the duodenal adenoma-carcinoma sequence in FAP
Project description:Background: Duodenal adenoma/adenocarcinomas are rare, and the global gene expression changes associated with the initial stages of carcinogenesis of these neoplasms have not been elucidated. Results: To comprehensively analyze genetic markers and pathways specific to early-stage duodenal adenoma/adenocarcinomas, transcriptional profiles of 4 fresh-frozen non-ampullary duodenal adenoma/adenocarcinomas and surrounding duodenal normal mucosa were compared. Key features of gene expression analysis demonstrated a strong correlation between these tumors and colorectal adenomas, as well as the Wnt/β-catenin pathway. These results shed new light on the transcriptional changes that occur during the early stages of duodenal tumorigenesis. All samples were obtained prior to treatment in order to minimize effects of cauterization, and immediately fresh-frozen.
Project description:Metabolic dysfunction-associated steatohepatitis (MASH) is a chronic liver disease associated with hepatic inflammation and fibrosis. Inflammasome-mediated IL-18 signaling is enhanced under MASH condition. IL-18 binding protein (IL-18BP) is a soluble protein that can block IL-18 actions and therapeutic potential of IL-18BP for MASH-induced fibrosis is largely unknown. We newly developed a human IL-18BP biologics (APB-R3) and injected it to mice to evaluate its pharmacologic efficacy. APB-R3 strikingly abolished hepatic fibrosis and reduced collagen markers. We further investigated whether APB-R3 could inhibit fibrotic activation of hepatic stellate cells (HSCs). This study proposes that abrogation of IL-18 signaling by boosting IL-18BP can strongly inhibit the development of MASH-induced fibrosis and our engineered IL-18BP biologics can become promising therapeutic candidate for curing MASH.
Project description:While macrophage heterogeneity during Metabolic dysfunction-associated steatohepatitis (MASH) has been described, the fate of these macrophages during MASH regression is poorly understood. Comparing macrophage heterogeneity during MASH progression vs regression, we identified specific macrophage sub- populations that are critical for MASH/fibrosis resolution. We elucidated the restorative pathways and gene signatures that define regression associated macrophages (RAM) and establish the importance of TREM2+ macrophages during MASH regression. Liver resident Kupffer cells are lost during MASH and are replaced by four distinct monocyte derived macrophage sub-populations. Trem2 is expressed in two macrophage sub- populations: (i) monocyte-derived macrophages occupying the Kupffer cell niche (MoKC) and (ii) lipid-associated macrophages (LAM). In regression livers, no new transcriptionally distinct MF sub-population emerged. However, the relative macrophage composition changed during regression compared to MASH. While MoKC was the major macrophage sub-population during MASH, they decreased during regression. LAM was the dominant macrophage sub-type during MASH regression and maintained Trem2 expression. Both MoKC and LAM were enriched in disease resolving pathways. Absence of TREM2 restricted the emergence of LAMs and formation of hepatic crown like structures (hCLS). TREM2+ macrophages are functionally important not only for restricting MASH-fibrosis progression, but also for effective regression of inflammation and fibrosis. TREM2+ MF are superior collagen degraders. Lack of TREM2+ macrophages also prevented elimination of hepatic steatosis and inactivation of HSC during regression, indicating their significance in metabolic co-ordination with other cell- types in the liver. TREM2 imparts this protective effect through multifactorial mechanisms, including improved phagocytosis, lipid-handling and collagen degradation.