Light Entrains Diurnal Changes in Insulin Sensitivity of Skeletal Muscle via Ventromedial Hypothalamic Neurons

Cell Rep. 2019 May 21;27(8):2385-2398.e3. doi: 10.1016/j.celrep.2019.04.093.

Abstract

Loss of synchrony between geophysical time and insulin action predisposes to metabolic diseases. Yet the brain and peripheral pathways linking proper insulin effect to diurnal changes in light-dark and feeding-fasting inputs are poorly understood. Here, we show that the insulin sensitivity of several metabolically relevant tissues fluctuates during the 24 h period. For example, in mice, the insulin sensitivity of skeletal muscle, liver, and adipose tissue is lowest during the light period. Mechanistically, by performing loss- and gain-of-light-action and food-restriction experiments, we demonstrate that SIRT1 in steroidogenic factor 1 (SF1) neurons of the ventromedial hypothalamic nucleus (VMH) convey photic inputs to entrain the biochemical and metabolic action of insulin in skeletal muscle. These findings uncover a critical light-SF1-neuron-skeletal-muscle axis that acts to finely tune diurnal changes in insulin sensitivity and reveal a light regulatory mechanism of skeletal muscle function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Circadian Rhythm
  • Humans
  • Insulin / metabolism*
  • Mice
  • Muscle, Skeletal / metabolism*
  • Phototherapy / methods*
  • Ventromedial Hypothalamic Nucleus / physiopathology*

Substances

  • Insulin