Protocol for in vivo and ex vivo assessments of glucose-stimulated insulin secretion in mouse islet β cells.

Pancreatic islet β cells secrete insulin in a biphasic manner when sensing high blood glucose level. This protocol describes the evaluation of different phases of insulin secretion, as well as basal, glucose-stimulated and total insulin secretion abilities, thereby enabling precise assessment of β cell function both in vivo and ex vivo. The in vivo assay consists of intravenous tube imbedding surgery and hyperglycemic clamp.

Ets1-Mediated Acetylation of FoxO1 Is Critical for Gluconeogenesis Regulation during Feed-Fast Cycles.

The homeostatic balance of hepatic glucose uptake and production is exquisitely controlled by hormonal signals during feed-fast cycles. FoxO1, a transcription factor that functions in the regulation of glucose homeostasis, undergoes posttranslational modifications, such as acetylation, in response to hormonal signals, yet the mechanism remains poorly elucidated. Through expression profiling of 324 co-factors of CBP, a well-known acetyl-transferase of FoxO1, we identify Ets1 as a modulator of FoxO1 acetylation that is highly associated with feed-fast cycles.