ABSTRACT: Adipose inflammation is a key component of cardiometabolic disease. We used microarray to profile gene expression changes in adipose tissue following administration of LPS (3ng/kg IV) to healthy human volunteers.
Project description:Identifying the regulatory mechanisms of genome-wide association study (GWAS) loci affecting adipose tissue has been restricted due to limited characterization of adipose transcriptional regulatory elements. We profiled chromatin accessibility in three frozen human subcutaneous adipose tissue needle biopsies and preadipocytes and adipocytes from the Simpson Golabi-Behmel Syndrome (SGBS) cell strain using an assay for transposase-accessible chromatin (ATAC-seq). We identified 68,571 representative accessible chromatin regions (peaks) across adipose tissue samples (FDR<5%). GWAS loci for eight cardiometabolic traits were enriched in these peaks (p<0.005), with the strongest enrichment for waist-hip ratio. Of 110 recently described cardiometabolic GWAS loci colocalized with adipose tissue eQTLs, 59 loci had one or more variants overlapping an adipose tissue peak. Annotated variants at the SNX10 waist-hip ratio locus and the ATP2A1-SH2B1 body mass index locus showed allelic differences in regulatory assays. These adipose tissue accessible chromatin regions elucidate genetic variants that may alter adipose tissue function to impact cardiometabolic traits.
Project description:Recent advances in RNA sequencing (RNA-Seq) have enabled the discovery of novel transcriptomic variations that are not possible with traditional microarray-based methods. Tissue and cell specific transcriptome changes during pathophysiological stress, in disease cases versus controls and in response to therapies are of particular interest to investigators studying cardiometabolic diseases. Thus, knowledge on the relationships between sequencing depth and detection of transcriptomic variation is needed for designing RNA-Seq experiments and for interpreting results of analyses. Using deeply sequenced RNA-Seq data derived from adipose of a healthy individual before and after systemic administration of endotoxin (LPS), we investigated the sequencing depths needed for studies of gene expression and alternative splicing (AS). We found that to detect expressed genes and AS events, ~100 million (M) filtered reads were needed. However, the requirement on sequencing depth for the detection of LPS modulated differential expression (DE) and differential alternative splicing (DAS) was much higher. To detect 80% of events, ~300M filtered reads were needed for DE analysis whereas at least 400M filtered reads were necessary for detecting DAS. Although the majority of expressed genes and AS events can be detected with modest sequencing depths (~100M filtered reads), the estimated gene expression levels and exon/intron inclusion levels were less accurate. We report the first study that evaluates the relationship between RNA-Seq depth and the ability to detect DE and DAS in human adipose. Our results suggest that a much higher sequencing depth is needed to reliably identify DAS events than for DE genes. Random sampling the RNA-seq data in different depth for gene and alternative-splicing analysis
Project description:Childhood cancer survivors who received abdominal radiotherapy (RT) or total body irradiation (TBI) are at increased risk for cardiometabolic disease, but the underlying mechanisms are unknown. We hypothesize that RT-induced adipose tissue dysfunction contributes to the development of cardiometabolic disease in the expanding population of childhood cancer survivors. We performed bulk RNA-sequencing of abdominal subcutaneous adipose tissue from adult childhood cancer survivors previously exposed to TBI, abdominal RT, or chemotherapy alone, alongside a group of healthy controls. We find that irradiated adipose tissue is characterized by a gene expression signature indicative of a complex macrophage expansion, which is also associated with dysregulated adipokine secretion. The full cohort is 30 subjects; however, 3 participants (2 in CHM group, 1 in CTL group) declined to share their sequencing data in a public database.
Project description:Analysis of perirenal adipose tissue from healthy kidney donors (age 44±9 years, BMI 25.8±3.3 kg/m2, mean±SD). The samples were taken bylaparoscopic technique beneath the incision plane that was created in the renal fascia (Greotas fascia) close to the renal vein. Ten samples of human perirenal adipose tissue
Project description:Dietary consumption of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) may protect against cardiometabolic disease through modulation of systemic and adipose inflammation. However, it is often difficult to detect the subtle effects of n-3 PUFA on inflammatory biomarkers in traditional intervention studies. We aimed to identify novel n-3 PUFA modulated gene expression using unbiased adipose transcriptomics during evoked endotoxemia in a clinical trial of n-3 PUFA supplementation. We analyzed adipose gene expression using RNA sequencing in the fenofibrate and omega-3 fatty acid modulation of endotoxemia (FFAME) trial of healthy individuals at three timepoints: before and after n-3 PUFA supplementation (n=8; 3600mg/day EPA/DHA) for 6weeks compared with placebo (n=6), as well as during a subsequent evoked inflammatory challenge (lipopolysaccharide 0.6ng/kg i.v.). As expected, supplementation with n-3 PUFA vs. placebo alone had only modest effects on adipose tissue gene expression. In contrast, the transcriptomic response to evoked endotoxemia was significantly modified by n-3 PUFA supplementation, with several genes demonstrating significant n-3 PUFA gene-nutrient interactions. These data highlight potential mechanisms whereby n-3 PUFA consumption may enhance the immune response to an inflammatory challenge.
Project description:Analysis of perirenal adipose tissue from healthy kidney donors (age 44±9 years, BMI 25.8±3.3 kg/m2, mean±SD). The samples were taken bylaparoscopic technique beneath the incision plane that was created in the renal fascia (Greotas fascia) close to the renal vein.
Project description:Purpose: To investigate the involvement of mTORC1 as a mediator of the actions of the PPARγ ligand rosiglitazone in subcutaneous inguinal white adipose tissue transcriptome; Methods: Mice bearing regulatory associated protein of mTOR (Raptor) deletion and therefore mTORC1 deficiency exclusively in adipocytes (adiponectin Cre recombinase) and littermate controls were fed a high-fat diet supplemented or not with the PPARγ agonist rosiglitazone (30 mg/kg/day) for 8 weeks and evaluated for inguinal white adipose tissue transcriptome (Rnaseq); Results: 3,2425 genes had their correspondent mRNA levels altered by either adipocyte Raptor deficiency or rosiglitazone administration or their combination. Among those, 408 genes modulated by rosiglitazone required mTORC1. Conclusion: PPARγ and mTORC1 are essential partners in the regulation of a cluster of genes in inguinal white adipose tissue.
Project description:Transcriptional profiling of mouse white adipose tissues The objective of this study is to explore the relationship between vitamin B6 activity and chronic inflammation of white adipose tissue in mice fed a high-fat diet. Twenty-four CD-1 mice were divided into two groups (n = 12) and fed either a 1 mg pyridoxine (PN) HCl /kg diet or a 35 mg PN HCl /kg diet for 8 weeks. We isolated total RNA from epididymal white adipose tissue of each group and compared gene expression profiles by DNA microarray data analysis.
Project description:Subcutaneous adipose tissue samples were obtained from severely obese individuals that underwent bariatric surgery. The goal of this study was to identify tissue specific methylation QTLs. Whole-transcriptome subcutaneous adipose tissue methylation levels were determined in 71 individuals with a BMI >35 kg/m2.
Project description:Visceral adipose tissue samples were obtained from severely obese individuals that underwent bariatric surgery. The goal of this study was to identify tissue specific methylation QTLs. Whole-transcriptome subcutaneous adipose tissue methylation levels were determined in 71 individuals with a BMI >35 kg/m2.