Resolution of Type 2 Diabetes Following Bariatric Surgery is Associated with Changes in Whole Blood Gene Expression

To investigate the effects of bariatric surgery on gene expression profile changes in whole blood in obese subjects with type 2 diabetes in a pilot study setting. Whole blood from eleven obese subjects with type 2 diabetes was collected in PAXgene tubes prior to and 6-12 months after bariatric surgery. Total RNA was isolated, amplified, labeled and hybridized to Illumina gene expression microarrays. Clinical and expression data were analyzed using a paired t-test, and correlations between changes in clinical trait and transcript levels were calculated. Pathways were identified using Ingenuity Pathway Analysis and DAVID gene ontology software. Bariatric surgery resulted in significant reduction of BMI, fasting plasma glucose and normalization of HbA1c levels. The expression levels of 204 transcripts, representing 200 unique genes, were significantly altered after bariatric surgery. Among the significantly regulated genes were GGT1, CAMP, DEFA1, LCN2, TP53, ZNF684, GPR50, PDSS1, OLR1, CNTNAP5, DHCR24, HHAT and SARDH, which have been previously implicated in lipid metabolism, obesity and/or type 2 diabetes. The changes in expression of seven transcripts, WDR35, FLF45244, DHCR24, TIGD7, TOPBP1, TSHZ1, and FAM8A1 were strongly correlated with the changes in body weight, fasting plasma glucose and HbA1c content. These preliminary data suggest that whole blood expression levels of specific transcripts may identify biomarkers associated with susceptibility for type 2 diabetes and/or therapeutic response. Trasncriptome profiling was performed on eleven obese subjects with type 2 diabetes, (5 females and 6 males) to compare expression changes before and 6 to 12 months after the subjects underwent bariatric surgery.