Project description:The TRIB1 locus has been associated with lipid dysfunction. The underlying mechanisms were investigated by examining the transcription landscape in response to TRIB1 suppression in human primary hepatocytes.
Project description:The TRIB1 locus has been associated with lipid dysfunction. The underlying mechanisms were investigated by examining the transcription landscape in response to TRIB1 suppression in human primary hepatocytes. Primary hepatocytes from 3 distinct donors were exposed for 48 h to an antisense nucleotide targeting TRIB1 or a control nucleotide. The resulting impacts on the transcription profile were assessed using Human Transcriptome 2.0 microarrays (Affymetrix).
Project description:Objective - The TRIB1 locus has been linked to hepatic triglyceride metabolism in mice and to plasma triglycerides and coronary artery disease (CAD) in humans. The lipid associated SNPs identified by genome-wide association studies (GWAS) are located ~ 30 kb downstream from TRIB1 suggesting complex regulatory effects on genes or pathways relevant to hepatic triglyceride metabolism. The goal of this study was to investigate the functional relationship between common SNPs at the TRIB1 locus and plasma lipid traits. Methods & Results - Characterization of the risk locus reveals that it encompasses a gene, TRIB1 associated locus (TRIBAL) comprised of a well conserved promoter region and an alternatively spliced transcript. Bioinformatic analysis and re-sequencing identified a single nucleotide polymorphism (SNP), rs2001844, within the promoter region that associates with increased plasma triglycerides, reduced HDL-C and CAD risk. Furthermore, we show that rs2001844 is an expression trait locus (eQTL) for TRIB1 expression in blood and alters TRIBAL promoter activity in a reporter assay model. The TRIBAL transcript has features typical of long noncoding RNAs (lncRNA), including poor sequence conservation. Modulation of TRIBAL expression had limited impact on either TRIB1 or lipid regulatory genes mRNA levels in human hepatocyte models. In contrast, TRIB1 knockdown markedly increased TRIBAL expression in HepG2 cells and primary human hepatocytes. Conclusions - These studies demonstrate an interplay between a novel locus,TRIBAL, and TRIB1. TRIBAL is located in the GWAS identified risk locus, responds to altered expression of TRIB1, harbors a risk SNP that is an eQTL for TRIB1 expression and associates with plasma triglyceride concentrations.
Project description:Objective - The TRIB1 locus has been linked to hepatic triglyceride metabolism in mice and to plasma triglycerides and coronary artery disease (CAD) in humans. The lipid associated SNPs identified by genome-wide association studies (GWAS) are located ~ 30 kb downstream from TRIB1 suggesting complex regulatory effects on genes or pathways relevant to hepatic triglyceride metabolism. The goal of this study was to investigate the functional relationship between common SNPs at the TRIB1 locus and plasma lipid traits. Methods & Results - Characterization of the risk locus reveals that it encompasses a gene, TRIB1 associated locus (TRIBAL) comprised of a well conserved promoter region and an alternatively spliced transcript. Bioinformatic analysis and re-sequencing identified a single nucleotide polymorphism (SNP), rs2001844, within the promoter region that associates with increased plasma triglycerides, reduced HDL-C and CAD risk. Furthermore, we show that rs2001844 is an expression trait locus (eQTL) for TRIB1 expression in blood and alters TRIBAL promoter activity in a reporter assay model. The TRIBAL transcript has features typical of long noncoding RNAs (lncRNA), including poor sequence conservation. Modulation of TRIBAL expression had limited impact on either TRIB1 or lipid regulatory genes mRNA levels in human hepatocyte models. In contrast, TRIB1 knockdown markedly increased TRIBAL expression in HepG2 cells and primary human hepatocytes. Conclusions - These studies demonstrate an interplay between a novel locus,TRIBAL, and TRIB1. TRIBAL is located in the GWAS identified risk locus, responds to altered expression of TRIB1, harbors a risk SNP that is an eQTL for TRIB1 expression and associates with plasma triglyceride concentrations. Transcriptome changes to TRIBAL downregulation (48 h) Huh7 were exposed to non-target or TRIBAL-specific antisense oligonucleotides for 48 h in normal (low glucose DMEM, 10% serum, Pen-Strep)
Project description:Objective - The TRIB1 locus has been linked to hepatic triglyceride metabolism in mice and to plasma triglycerides and coronary artery disease (CAD) in humans. The lipid associated SNPs identified by genome-wide association studies (GWAS) are located ~ 30 kb downstream from TRIB1 suggesting complex regulatory effects on genes or pathways relevant to hepatic triglyceride metabolism. The goal of this study was to investigate the functional relationship between common SNPs at the TRIB1 locus and plasma lipid traits. Methods & Results - Characterization of the risk locus reveals that it encompasses a gene, TRIB1 associated locus (TRIBAL) comprised of a well conserved promoter region and an alternatively spliced transcript. Bioinformatic analysis and re-sequencing identified a single nucleotide polymorphism (SNP), rs2001844, within the promoter region that associates with increased plasma triglycerides, reduced HDL-C and CAD risk. Furthermore, we show that rs2001844 is an expression trait locus (eQTL) for TRIB1 expression in blood and alters TRIBAL promoter activity in a reporter assay model. The TRIBAL transcript has features typical of long noncoding RNAs (lncRNA), including poor sequence conservation. Modulation of TRIBAL expression had limited impact on either TRIB1 or lipid regulatory genes mRNA levels in human hepatocyte models. In contrast, TRIB1 knockdown markedly increased TRIBAL expression in HepG2 cells and primary human hepatocytes. Conclusions - These studies demonstrate an interplay between a novel locus,TRIBAL, and TRIB1. TRIBAL is located in the GWAS identified risk locus, responds to altered expression of TRIB1, harbors a risk SNP that is an eQTL for TRIB1 expression and associates with plasma triglyceride concentrations. HepG2 hepatoma cells were stably infected with TRIBAL1 or no insert carrying lentiviruses
Project description:Objective - The TRIB1 locus has been linked to hepatic triglyceride metabolism in mice and to plasma triglycerides and coronary artery disease (CAD) in humans. The lipid associated SNPs identified by genome-wide association studies (GWAS) are located ~ 30 kb downstream from TRIB1 suggesting complex regulatory effects on genes or pathways relevant to hepatic triglyceride metabolism. The goal of this study was to investigate the functional relationship between common SNPs at the TRIB1 locus and plasma lipid traits. Methods & Results - Characterization of the risk locus reveals that it encompasses a gene, TRIB1 associated locus (TRIBAL) comprised of a well conserved promoter region and an alternatively spliced transcript. Bioinformatic analysis and re-sequencing identified a single nucleotide polymorphism (SNP), rs2001844, within the promoter region that associates with increased plasma triglycerides, reduced HDL-C and CAD risk. Furthermore, we show that rs2001844 is an expression trait locus (eQTL) for TRIB1 expression in blood and alters TRIBAL promoter activity in a reporter assay model. The TRIBAL transcript has features typical of long noncoding RNAs (lncRNA), including poor sequence conservation. Modulation of TRIBAL expression had limited impact on either TRIB1 or lipid regulatory genes mRNA levels in human hepatocyte models. In contrast, TRIB1 knockdown markedly increased TRIBAL expression in HepG2 cells and primary human hepatocytes. Conclusions - These studies demonstrate an interplay between a novel locus,TRIBAL, and TRIB1. TRIBAL is located in the GWAS identified risk locus, responds to altered expression of TRIB1, harbors a risk SNP that is an eQTL for TRIB1 expression and associates with plasma triglyceride concentrations.
Project description:We used Perturb-seq to characterize the role of putative NAFLD genes prioritized from molecular human genetic studies in differentiated HepaRG cells.
Project description:Inorganic arsenic, a ubiquitous environmental contaminant of food and drinking water, is a human carcinogen associated with lung, liver, prostate, renal, and bladder cancers. It has been postulated that inorganic arsenic targets stem cells or partially differentiated progenitor cells, causing their oncogenic transformation. This is proposed to be one of the key mechanisms in arsenic-associated carcinogenesis; however, the underlying mechanisms for this process remain largely unknown. To address this question, human liver HepaRG cells, at progenitor and differentiated states, were continuously treated with a non-cytotoxic concentration of 1 μM sodium arsenite (NaAsO2). Briefly, in Experiment 1, three days after the initial seeding, 1 μM NaAsO2 was added to the media and the cells were maintained in the NaAsO2-containing media for an additional 25 days. In Experiment 2, fourteen days after the initial seeding, 1 μM NaAsO2 was added to the media and the cells were maintained in the NaAsO2-containing media for an additional 14 days. In Experiment 1 and Experiment 2, control and NaAsO2-treated cells were harvested on the 28th day after the initial seeding. In Experiment 3, twenty-eight days after the initial seeding, the terminally-differentiated cells were treated continuously with 1 μM NaAsO2 for an additional 14 days and then harvested. Transcriptomic analysis of NaAsO2-treated progenitor-like HepaRG cells (Experiment 1 and Experiment 2) identified 743 and 639 differentially expressed genes, respectively, among which 343 genes were expressed in common. Pathway analysis of common differentially expressed genes demonstrated a substantial inhibition of cellular metabolic pathways, mainly lipid and xenobiotic metabolism, and cell death pathways. In contrast, cell proliferation, cell survival, and inflammation, were substantially activated. Treatment of differentiated HepaRG cells with NaAsO2 (Experiment 3) resulted in prominent gene expression changes, with a total of 1058 transcripts being significantly different from the control HepaRG cells. Pathway analysis of differentially expressed genes in NaAsO2-treated cells differentiated HepaRG cells showed activation of cellular death-associated pathways and inhibition of cell survival and cell proliferation.