Transcriptomics driven metabolic pathway analysis reveals similar metabolic alterations in diet- and chemical-induced mouse NASH model and human
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ABSTRACT: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and can rapidly progress to non-alcoholic steatohepatitis (NASH). Accurate preclinical models and robust methodologies need to be established to understand the underlying metabolic mechanisms and develop treatment strategies. Based on our meta-analysis of currently available data on several mouse models, we hypothesized a diet- and chemical-induced NASH model closely resembles metabolic alteration in human. We developed an already established WD+CCl4-induced NASH model. We developed and performed transcriptomics driven metabolic pathway analysis (TDMPA) using differentially expressed genes in mouse NASH liver compared to control. We compared the altered metabolic pathways and enzymatic reactions to human NASH. We performed functional assays and lipidomics to confirm our findings related to metabolic alterations. Numerous metabolic pathways were altered in human NASH and mouse model. De novo triglyceride biosynthesis, fatty acid beta-oxidation, bile acid biosynthesis, cholesterol metabolism, and oxidative phosphorylation were the most influenced pathways. We confirmed significant reduction in mitochondrial functions and bioenergetics in NASH model, and in acylcarnitines. We identified a wide range of lipid species within the most perturbed pathways predicted by TDMPA. Triglycerides, phospholipids and bile acids were increased significantly in NASH, confirming our initial observations. We identified several metabolic pathways that typify NASH pathophysiology in human. By comparing human and mouse metabolic signatures, we evaluated metabolic resemblance of mouse model to human and its suitability for the study of the disease and potential usage for drug discovery and testing. We also presented TDMPA, a novel methodology to evaluate metabolic pathway alterations in metabolic disorders and a valuable tool for defining metabolic space to aid experimental design for lipidomics and metabolomics approaches.
Project description:Non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) is a significant risk factor for hepatocellular carcinoma (HCC). However, a preclinical model of progressive NAFLD/NASH is largely lacking. Here, we report that mice with hepatocyte-specific deletion of Tid1, encoding a mitochondrial cochaperone, tended to develop NASH-dependent HCC. Mice with hepatic Tid1 deficiency showed impairing mitochondrial function and causing fatty acid metabolic dysregulation; meanwhile, sequentially developed fatty liver, NASH, and cirrhosis/HCC in a diethylnitrosamine (DEN) induced oxidative environment. The pathological signatures of human NASH, including cholesterol accumulation and activation of inflammatory and apoptotic signaling pathways, are also present in these mice. Clinically, low Tid1 expression was associated with unfavorable prognosis in patients with HCC. Empirically, hepatic Tid1 deficiency directly disrupts entire mitochondria that play a key role in the NASH-dependent HCC development. Overall, we established a new mouse model that develops NASH-dependent HCC and provides a promising approach to improve the treatment.
Project description:Non-alcoholic fatty liver (NAFL) has the potential to progress to non-alcoholic steatohepatitis (NASH) or to promote type 2 diabetes mellitus (T2DM). However, NASH and T2DM do not always develop coordinately. We established rat models of NAFL, NASH, and NAFL + T2DM to recapitulate different phenotypes associated with NAFLD and its progression. Microarrays were used to identify hepatic gene expression changes in each of these models. The goal is to identify a predictor of different NAFLD progressions. Non-alcoholic fatty liver disease (NAFLD) is recognized as a low-grade systemic inflammatory state with both hepatic and extra-hepatic manifestations. We aimed to identify common key regulators and adaptive pathways in different NAFLD phenotypes. NAFL, NASH and NAFL+T2DM rat models were used to represent simple fatty liver, fatty liver with severe hepatic manifestations, and fatty liver with severe metabolic manifestations, respectively. We applied microarray analysis to characterize the key regulators and adaptive pathways in different NAFLD phenotypes. There are 12 samples in our study which belonged to 4 groups, and each group contains 3 different samples.
Project description:Non-alcoholic fatty liver disease is now considered the most common form of chronic liver disease. It is a complex metabolic disease that silently progresses into non-alcoholic steatohepatitis (NASH). In fact, NASH is the tipping point for pericellular fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Despite being a complex metabolic disease, identification of the metabolic readout that functions in metabolic pathway perpetuation for HCC progression from NASH is still incompletely understood. With the aid of LC MS/MS this study unveiled the metabolic fingerprint of NASH and HCC-NASH patients and it illustrates a detailed map for the most predominant reprogrammed metabolic pathways that target HCC development from NASH. https://doi.org/10.3390/ijms24010210
Project description:Non-alcoholic steatohepatitis (NASH) is a common chronic liver disease associated with metabolic disorders such as obesity, diabetes, and high cholesterol. It results in inflammation and fibrosis of liver tissue, eventually leading to cirrhosis and liver cancer. While LPCAT3 has been linked to the formation of fat cells, its role in the development of NASH is not yet fully understood. The purpose of this study was to gain insights into the mechanisms that accelerate NASH induced by LPCAT3. We utilized a genetic engineering rodent model and transcriptomics sequencing approach to explore the role and regulatory mechanism of LPCAT3 in the development of NAFLD. Approach & Results: We studied the impact of Lpcat3 deficiency on NASH progression using three distinct Lpcat3 liver-specific knockout mouse (LKO) models and conducted RNA sequencing, lipidomics, and metabolomics studies on liver samples. Human samples were obtained and analyzed for LPCAT3 expression in patients with NASH to determine its correlation with disease severity. The HepG2 and Huh-7 cell lines were utilized for in vitro analyses. We discovered that LPCAT3 expression was elevated in human NASH livers, and its expression correlated with NAFLD activity score and fibrosis stage. Lpcat3 deficiency in the mouse liver slows the development of diet-induced NASH. Lpcat3 deficiency mechanistically reduces lipid production by inhibiting lipid metabolic pathwaysDeletion of Lpcat3 significantly improved lipid accumulation in NASH mice, possibly due to the involvement of sult1e1 in lipogenesis and oxidation regulation. Moreover, the hepatic overexpression of Lpcat3 significantly intensified lipid buildup in steatotic cells, indicating that LPCAT3 plays a crucial role in the progression of NASH. Conclusions: The findings indicate that LPCAT3 regulates the participation of sult1e1 in both adipogenesis and oxidation, leading to enhanced NASH outcomes.
Project description:Non-alcoholic steatohepatitis (NASH) is a common chronic liver disease associated with metabolic disorders such as obesity, diabetes, and high cholesterol. It results in inflammation and fibrosis of liver tissue, eventually leading to cirrhosis and liver cancer. While LPCAT3 has been linked to the formation of fat cells, its role in the development of NASH is not yet fully understood. The purpose of this study was to gain insights into the mechanisms that accelerate NASH induced by LPCAT3. We utilized a genetic engineering rodent model and transcriptomics sequencing approach to explore the role and regulatory mechanism of LPCAT3 in the development of NAFLD. Approach & Results: We studied the impact of Lpcat3 deficiency on NASH progression using three distinct Lpcat3 liver-specific knockout mouse (LKO) models and conducted RNA sequencing, lipidomics, and metabolomics studies on liver samples. Human samples were obtained and analyzed for LPCAT3 expression in patients with NASH to determine its correlation with disease severity. The HepG2 and Huh-7 cell lines were utilized for in vitro analyses. We discovered that LPCAT3 expression was elevated in human NASH livers, and its expression correlated with NAFLD activity score and fibrosis stage. Lpcat3 deficiency in the mouse liver slows the development of diet-induced NASH. Lpcat3 deficiency mechanistically reduces lipid production by inhibiting lipid metabolic pathwaysDeletion of Lpcat3 significantly improved lipid accumulation in NASH mice, possibly due to the involvement of sult1e1 in lipogenesis and oxidation regulation. Moreover, the hepatic overexpression of Lpcat3 significantly intensified lipid buildup in steatotic cells, indicating that LPCAT3 plays a crucial role in the progression of NASH. Conclusions: The findings indicate that LPCAT3 regulates the participation of sult1e1 in both adipogenesis and oxidation, leading to enhanced NASH outcomes.
Project description:Non-alcoholic fatty liver disease is continuum of disorders among which non-alcoholic steatohepatitis (NASH) is particularly associated with a negative prognosis. Hepatocyte lipotoxicity is one of the main pathogenic factors of liver fibrosis and NASH. However, the molecular mechanisms regulating this process are poorly understood. Here, we integrated transcriptomic and chromatin accessibility analyses from human liver and mouse hepatocytes to identify lipotoxicity-sensitive transcription factors. We found that the transcription factors MAFK and TCF4 were activated in liver from NASH patients and by mouse hepatocyte lipotoxicity. Genetic deletion of these transcription factors protected hepatocytes against saturated fatty acid oversupply. Notably, MAFK- and TCF4-regulated gene expression linked to lipotoxicity closely correlated with transcriptional patters in fibrosis progression in NASH patients. Collectively, our findings uncovered novel molecular insights into lipotoxicityinduced NASH, revealing the relevance and therapeutic potential of MAFK and TCF4 in human disease.
Project description:Global gene expression patterns of 2 human steatosis and 9 human non-alcoholic steatohepatitis (NASH) together with their respective control patterns were analyzed to define the non-alcoholic fatty liver disease (NAFLD) progression molecular characteristics and to define NASH early markers from steatosis. Human liver samples of steatosis and non-alcoholic steatohepatitis were selected for RNA extraction and hybridization on Affymetrix microarrays. This dataset is part of the TransQST collection.
Project description:Non-alcoholic fatty liver disease (NAFLD) is characterized by a series of pathological changes that can progress from simple fatty liver disease to non-alcoholic steatohepatitis (NASH). The objective of this study is to describe changes in global gene expression associated with the progression of NAFLD. This study is focused on the expression levels of genes responsible for the absorption, distribution, metabolism and excretion (ADME) of drugs. Differential gene expression between three clinically defined pathological groups; normal, steatosis and NASH was analyzed. The samples were diagnosed as normal, steatotic, NASH with fatty liver (NASH fatty) and NASH without fatty liver (NASH NF). Genome-wide mRNA levels in samples of human liver tissue were assayed with Affymetrix GeneChipM-. Human 1.0ST arrays
Project description:Human genetic studies have identified several MARC1 variants as protective against non-alcoholic fatty liver diseases (NAFLD). The MARC1 variants are associated with reduced lipid profiles, liver enzymes, and liver-related mortality. However, the role of mitochondrial amidoxime reducing component 1 (mARC1), encoded by MARC1, in NAFLD is still unknown and the therapeutic potential of this target has never been developed. Given that mARC1 is mainly expressed in hepatocytes, we developed an N-acetylgalactosamine conjugated mouse mARC1 siRNA to address this. In ob/ob mice, knockdown of mARC1 in mouse hepatocytes resulted in decreased liver weight, serum lipid enzymes, low-density lipoprotein cholesterol, and liver triglycerides. Loss of mARC1 also improved the lipid profiles and attenuated liver pathological changes in two diet-induced nonalcoholic steatohepatitis (NASH) mouse models. A comprehensive analysis of mARC1-deficient liver in NASH by metabolomics, proteomics, and lipidomics showed that mARC1 knockdown partially restored metabolites and lipids altered by diets. Taken together, loss of mARC1 protects mouse liver from NASH, suggesting a potential therapeutic approach of NASH by downregulation of mARC1 in hepatocytes.
Project description:Non-alcoholic steatohepatitis (NASH) is a T-cell mediated, auto-aggressive condition that can result in progressive liver disease and hepatocellular carcinoma. Gastrointestinal B-cells are activated and increased in number in mouse and human NASH, licensing metabolic-cell activation to induce NASH antigen- and microbiota-independently. Genetic or therapeutic depletion of B-cells systemically or gastrointestinal B-cells specifically prevented or reverted NASH and fibrosis. Clinical and molecular analyses from NASH patients demonstrated IgA-levels and activated FcRy+ hepatic myeloid cells to correlate with liver fibrosis degree.