Project description:Background & Aims: Non-alcoholic steatohepatitis (NASH), a subtype of non-alcoholic fatty liver disease (NAFLD) that can lead to fibrosis, cirrhosis, and hepatocellular carcinoma, is characterized by hepatic inflammation. Despite evolving therapies aimed to ameliorate inflammation in NASH, the transcriptional changes that lead to inflammation progression in NAFLD remain poorly understood. The aim of this study is to define transcriptional changes in early, non-fibrotic NAFLD using a biopsy-proven non-fibrotic NAFLD cohort. Methods: We extracted RNA from liver tissue of 40 patients with biopsy-proven NAFLD based on NAFLD Activity Score (NAS) (23 with NAS ≤3, 17 with NAS ≥5) and 21 healthy controls and compared changes in expression of 594 genes involved in innate immune function. Results: Compared to healthy controls, NAFLD patients with NAS ≥5 had differential expression of 211 genes, while those with NAS ≤3 had differential expression of only 14 genes. Notably, osteopontin (SPP1) (3.74-fold in NAS ≤3, 8.28-fold in NAS ≥5) and CXCL10 (2.27-fold in NAS ≤3, 8.28-fold in NAS ≥5) gene expression were significantly upregulated with histologic progression of NAFLD.
Project description:Recent studies have identified a genetic variant rs641738 near two genes encoding membrane bound O-acyltransferase domain-containing 7 (MBOAT7) and transmembrane channel-like 4 (TMC4) that associate with increased risk of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcohol-related cirrhosis, and liver fibrosis in those infected with viral hepatitis1-7. Based on hepatic expression quantitative trait loci analysis it has been suggested that MBOAT7 loss of function promotes liver disease progression1-7, but this has never been formally tested. Here we show that Mboat7 loss, but not Tmc4, in mice is sufficient to promote the progression of NAFLD in the setting of high fat diet. Mboat7 loss of function is associated with accumulation of its substrate lysophosphatidylinositol (LPI) lipids, and direct administration of LPI promotes hepatic inflammatory and fibrotic transcriptional changes in an Mboat7-dependent manner. These studies reveal a novel role for MBOAT7-driven acylation of LPI lipids in suppressing the progression of N
Project description:Recent studies have identified a genetic variant rs641738 near two genes encoding membrane bound O-acyltransferase domain-containing 7 (MBOAT7) and transmembrane channel-like 4 (TMC4) that associate with increased risk of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcohol-related cirrhosis, and liver fibrosis in those infected with viral hepatitis1-7. Based on hepatic expression quantitative trait loci analysis it has been suggested that MBOAT7 loss of function promotes liver disease progression1-7, but this has never been formally tested. Here we show that Mboat7 loss, but not Tmc4, in mice is sufficient to promote the progression of NAFLD in the setting of high fat diet. Mboat7 loss of function is associated with accumulation of its substrate lysophosphatidylinositol (LPI) lipids, and direct administration of LPI promotes hepatic inflammatory and fibrotic transcriptional changes in an Mboat7-dependent manner. These studies reveal a novel role for MBOAT7-driven acylation of LPI lipids in suppressing the progression of N To assess the role of MBOAT7 loss of function in NAFLD and NASH. We injected the substrate of MBOAT7, lysophosphatidylinostiol 18:0, or Saline in the portal vein of mice. The livers were then snap frozen and a standard RNA isolation was run to assess transcriptome changes after the addition of LPI's for six hours.
Project description:Non-alcoholic fatty liver disease (NAFLD) is of increasing prevalence and concern. NAFLD can progress to non-alcoholic steatohepatitis (NASH), to cirrhosis and finally to end-stage liver disease where liver transplantation is required. We aimed to characterise this progression by performing single nuclei transcriptomic analysis of liver biopsies taken from patients across the disease spectrum. We have observed that hepatocytes are the cell type affected mostly by the disease and describe plasticity between cell types which may represent a regenerative process.
Project description:Background/Aims: There is a major unmet need to assess prognostic impact of anti-fibrotics in clinical trials due to the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression. Methods: A Fibrosis Progression Signature (FPS) was defined to predict fibrosis progression within 5 years in HCV and NAFLD patients with no to minimal fibrosis at baseline (n=421), and validated in an independent NAFLD cohort (n=78). The FPS was used to assess response to 13 candidate anti-fibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n=78), and cenicriviroc in NASH patients enrolled in a clinical trial (n=19, NCT02217475). A serum-protein-based surrogate FPS (FPSec) was developed and technically evaluated in a liver disease patient cohort (n=79). Results: A 20-gene FPS was defined and validated in an independent NAFLD cohort (aOR=10.93, AUROC=0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacological target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate anti-fibrotics identified rational combination therapies based on epigallocatechin gallate, some of which were validated for enhanced anti-fibrotic effect in ex vivo culture of clinical liver tissues. In NASH patients treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of PPARalpha pathway was absent in patients without fibrosis improvement, suggesting benefit of combining PPARalpha agonism to improve anti-fibrotic efficacy of cenicriviroc. A 7-protein FPSec panel showed concordant prognostic prediction with FPS. Conclusion: FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform anti-fibrotic drug development.
Project description:We isolated non-hematopoietic cells from fibrotic and non-fibrotic mouse bone marrow and perfomed scRNAseq on them. We identified 8 different stromal populations. Our analysis revealed two distinct mesenchymal stromal cells (MSC) subsets as pro-fibrotic cells. MSCs were functionally reprogrammed in a stagedependent manner with loss of their progenitor status and initiation of differentiation in the prefibrotic stage and acquisition of a pro-fibrotic and inflammatory phenotype in the fibrotic stage. In parallel, IL-33-expressing myelinating Schwann cell progenitors expanded, likely as a repair mechanism for the previously described neuropathy in MPN.
Project description:Background/Aims: There is a major unmet need to assess prognostic impact of anti-fibrotics in clinical trials due to the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression. Methods: A Fibrosis Progression Signature (FPS) was defined to predict fibrosis progression within 5 years in HCV and NAFLD patients with no to minimal fibrosis at baseline (n=421), and validated in an independent NAFLD cohort (n=78). The FPS was used to assess response to 13 candidate anti-fibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n=78), and cenicriviroc in NASH patients enrolled in a clinical trial (n=19, NCT02217475). A serum-protein-based surrogate FPS (FPSec) was developed and technically evaluated in a liver disease patient cohort (n=79). Results: A 20-gene FPS was defined and validated in an independent NAFLD cohort (aOR=10.93, AUROC=0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacological target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate anti-fibrotics identified rational combination therapies based on epigallocatechin gallate, some of which were validated for enhanced anti-fibrotic effect in ex vivo culture of clinical liver tissues. In NASH patients treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of PPARalpha pathway was absent in patients without fibrosis improvement, suggesting benefit of combining PPARalpha agonism to improve anti-fibrotic efficacy of cenicriviroc. A 7-protein FPSec panel showed concordant prognostic prediction with FPS. Conclusion: FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform anti-fibrotic drug development.