How Circadian Rhythm Impacts the Release of Insulin
Body clocks, which align human behaviors like eating and sleeping with the 24-hour light-dark cycle, may have an even greater impact than typically given credit for, particularly for people living with diabetes. For starters, everyone has multiple body clocks: In addition to a master clock in the brain, the body has peripheral clocks in individual organs. This includes circadian clocks that regulate hormones and balance blood sugar levels.
In 2010, Northwestern Medicine scientists determined that the circadian clock in the pancreas is essential to controlling insulin secretion and balancing blood sugar levels in mice. When the clock genes were removed, the pancreas didn’t work right, and mice developed obesity and type two diabetes. Still, the findings required further research if the scientists wanted to leverage the clock genes to treat conditions.
Since then, the team, led by Joseph Bass, MD, PhD, chief of Endocrinology in the Department of Medicine and the Charles F. Kettering Professor of Medicine at Northwestern Medicine Feinberg School of Medicine, has studied how clock genes affect the normal function of the pancreas. The scientists’ latest study pinpointed thousands of genes in the pancreas that the circadian clock controls through special proteins, called transcription factors, that tell a cell how to function. The research looked specifically at the beta cells that release insulin into the bloodstream. The team established a new gene map that shows the pathways through which the internal body clock dictates how and when the pancreas produces insulin, as well as how it maintains and anticipates daily changes in the environment by aligning with the rotation of the Earth.
Dr. Bass and his team hope these findings can someday lead to new therapies for everyone with diabetes. The Northwestern Medicine scientists plan to continue studying how the body’s various circadian clocks interact and how their rhythm can be disrupted. This would include not only diabetes, but also day-to-day conditions like jet lag, stress and dietary changes as well as the normal aging process.