Affymetrix profiling of IMIDIA biobank samples from organ donors and partially pancreatectomized patients [organ donor cohort]. Homo sapiens

Pancreatic islet beta cell failure causes type 2 diabetes (T2D). The IMIDIA consortium has used a strategy entailing a stringent comparative transcriptomics analysis of islets isolated enzymatically or by laser microdissection from two large cohorts of non-diabetic (ND) and T2D organ donors (OD) or partially pancreatectomized patients (PPP). This work led to the identification of a signature of genes that were differentially expressed between T2D and ND regardless of the sample type (OD or PPP). This signature includes 19 genes, of which 9 have never been previously reported to be differentially expressed in T2D islets. The PPP cohort also includes samples from individuals with impaired glucose tolerance (IGT) or recent onset diabetes associated with a pancreatic exocrine disorder (T3cD). Notably, none of the 19 signature genes of T2D islets were significantly dysregulated in islets of subjects with IGT or T3cD, suggesting that their changed expression reflects beta cell deterioration rather than a deficit preceding it. Overall design: 206 pancreatic islet samples in total. 103 islet samples from organ donors of which 19 were type 2 diabetic (T2D) and 84 non-diabetic (ND). 103 islet samples from partially pancreatectomized patients of which 36 were T2D, 32 ND, 15 impaired glucose tolerance (IGT) and 20 type 3 diabetic (T3cD). Comparisons comparing T2D (cases) against ND (controls) were performed separately for OD and PPP cohorts