The impact of aging on beta-cell functionality and structural integrity under metabolic stress conditions in diabetes-prone and diabetes-resistant mice [ob].

Young and aged, diabetes-prone (NZO/HIBomDife) as well as diabetes-resistant (B6.V-Lep ob/ob) mice exhibited different islet functions and phenotypes in response to a carbohydrate-rich diet (CRD) subsequent to a high-fat, carbohydrate-free diet (HFD). To unravel the molecular basis underlying these alterations, a microarray-based transcriptome analysis of isolated pancreatic islets before and after 2 days of CRD feeding was performed. A high number of differentially expressed genes associated with redox homeostasis, in particular Thioredoxin-interacting protein (Txnip), as well as genes involved in cell cycle entry and cell proliferation, such as cyclins, cyclin-dependent kinases and Mki67 were identified and associated with these changes. In addition, aged NZO/HIBomDife and age-matched, B6.V-Lep ob/ob mice revealed a high overlap of regulated genes, also linked to cell cycle progression under the same dietary regimen. Metabolic-stressed induced gene expression in murine pancreatic islets was determined at week 18 (young) and 39 (aged) of HFD feeding as well as 2 days after an additional CRD intervention (n = 5 mice per group).