The rhythmicity of circadian clocks in macrophage immune cells within fat tissue is dysregulated in mice fed a high-fat diet, leading to increased inflammation and decreased whole-body insulin sensitivity, reports a team of Texas A&M University System scientists (Xu H et al. J Biol Chem. 2014;289:16374-16388).
The investigators also found that disruption of the clock genes Per1 and Per2 recapitulates this inflammation and that transferring Per1/2-disrupted bone marrow cells into wild-type mice enhances high-fat diet–induced fat and liver inflammation and systemic insulin resistance. Previous research has indicated that disruption of circadian clock function alters metabolism and promotes obesity, but the mechanisms involved have remained unknown. The details behind the Per1 and Per2 genes’ effects on macrophages are still unclear.
Hampton T. Circadian Clock Dysregulation Linked to Obesity-Related Diseases. JAMA. 2014;312(1):19. doi:10.1001/jama.2014.8061