Editor's Summary

29 July 2010

Clocking on to diabetes


During periods of feeding, pancreatic islets secrete insulin to maintain glucose homeostasis — a rhythmic process that is disturbed in people with diabetes. Experiments in mice now show that the pancreatic islets contain their own biological clock, which orchestrates insulin secretion during the sleep–wake cycle. The transcription factors CLOCK and BMAL1 are vital for this process, and mice with defective copies of the genes Clock and Bmal1 develop hypoinsulinaemia and diabetes. By demonstrating that a local tissue clock integrates circadian and metabolic signals in pancreatic β-cells, this work suggests that circadian analyses are crucial for deeper understanding of metabolic phenotypes, as well as for the treatment of metabolic diseases such as type 2 diabetes.

News and ViewsMetabolism: Tick, tock, a β-cell clock

The daily light–dark cycle affects many aspects of normal physiology through the activity of circadian clocks. It emerges that the pancreas has a clock of its own, which responds to energy fluctuations.

Katja A. Lamia & Ronald M. Evans

doi:10.1038/466571a

LetterDisruption of the clock components CLOCK and BMAL1 leads to hypoinsulinaemia and diabetes

Biliana Marcheva, Kathryn Moynihan Ramsey, Ethan D. Buhr, Yumiko Kobayashi, Hong Su, Caroline H. Ko, Ganka Ivanova, Chiaki Omura, Shelley Mo, Martha H. Vitaterna, James P. Lopez, Louis H. Philipson, Christopher A. Bradfield, Seth D. Crosby, Lellean JeBailey, Xiaozhong Wang, Joseph S. Takahashi & Joseph Bass

doi:10.1038/nature09253