GSE162653
RNA-seq analysis of human white adipose tissue from normal weight and obese individuals prior to and following 12-week intervention with fish oil or corn oil
Purpose: To identify, using RNA-sequencing, differentially expressed genes in the white adipose tissue in obesity and in response to lipid intervention in both normal weight and obese individuals. Methods: White adipose tissue mRNA profiles of normal weight and obses humans at baseline (0-weeks) and 12-weeks after fish oil (3d/day of which 1.1g EPA and 0.8g DHA) or corn oil (3g/day) supplementation were generated by deep sequencing using RNA sequencing. The sequence reads that passed quality filters were aligned to the human genome using TopHat and analyzed at the gene level using DESeq2. qRT–PCR validation was performed using Taqman probe assays Results: Using an optimized data analysis workflow, we mapped reads to the human genome (hg38.0) and identified 789 genes differentially expressed between normal weight and obese individuals at baseline (week-0) (adjusted p value <0.05 and fold change >2). 623 of these were upregulated and 175 were downregulated. Geneset enrichment analysis identified several enriched pathways, including regulation of immune and inflammatory response, tissue growth and glucose metabolism in obese indvidiuals in comparison to normal weight. We identified 26 genes differentially expressed in normal weight individuals in response to fish oil intervention (week-12) (adjusted p value <0.05 and fold change >1). 14 of these were upregulated and 12 were downregulated. We identified 8 genes differentially expressed in obese individuals in response to fish oil intervention (week-12) (adjusted p value <0.05 and fold change >1). 3 of these were upregulated and 5 were downregulated. Geneset enrichment analysis identified several enriched pathways, including regulation of immune and inflammatory response in both normal weight and obese individuals in response to fish oil intervention with greater effects in normal weight individuals. Conclusions: Our study provides novel insights into the association of obesity and changes to the human white adipose tissue transcriptome, in addition to the effects of fish oil (EPA and DHA) on the transcriptome of normal weight and obese individuals and differences in response between these BMI subgroups. Our study further identifies putative gene targets and molecular pathways that help to understand how obesity results in adipose tissue dysfunction and how EPA and DHA may modulate the long term expression of gene networks and disease pathways related to onset of obesity associated inflammation. Overall design: Human white adipose tissue RNA transcriptomes from normal weight and obese individuals and following 12 week fish oil (3g/day, 1.1g EPA and 0.8g DHA) or corn oil (3g/day)( supplememtation.