[PDF][PDF] Integrative genomics outlines a biphasic glucose response and a ChREBP-RORγ axis regulating proliferation in β cells

SF Schmidt, JGS Madsen, KØ Frafjord… - Cell reports, 2016 - cell.com
SF Schmidt, JGS Madsen, KØ Frafjord, L la Cour Poulsen, S Salö, M Boergesen, A Loft
Cell reports, 2016cell.com
Glucose is an important inducer of insulin secretion, but it also stimulates long-term adaptive
changes in gene expression that can either promote or antagonize the proliferative potential
and function of β cells. Here, we have generated time-resolved profiles of enhancer and
transcriptional activity in response to glucose in the INS-1E pancreatic β cell line. Our data
outline a biphasic response with a first transcriptional wave during which metabolic genes
are activated, and a second wave where cell-cycle genes are activated and β cell identity …
Summary
Glucose is an important inducer of insulin secretion, but it also stimulates long-term adaptive changes in gene expression that can either promote or antagonize the proliferative potential and function of β cells. Here, we have generated time-resolved profiles of enhancer and transcriptional activity in response to glucose in the INS-1E pancreatic β cell line. Our data outline a biphasic response with a first transcriptional wave during which metabolic genes are activated, and a second wave where cell-cycle genes are activated and β cell identity genes are repressed. The glucose-sensing transcription factor ChREBP directly activates first wave enhancers, whereas repression and activation of second wave enhancers are indirect. By integrating motif enrichment within late-regulated enhancers with expression profiles of the associated transcription factors, we have identified multiple putative regulators of the second wave. These include RORγ, the activity of which is important for glucose-induced proliferation of both INS-1E and primary rat β cells.
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