Areas of research currently pursued in the Combs lab include the birth and death of adipocytes and the secretion of adipokines, the effect of cytokines on insulin, and the changes in glucose metabolism invoked by elevation of insulin sensitivity in long-lived mouse-models.

Adipose Tissue and Adipokines

Adipose tissue, commonly referred to as fat, consists mostly of adipocytes. Adipocytes are terminally differentiated cells derived from progenitor cells that reside in adipose tissue. Besides being endowed with an incredible capacity for lipid storage and release, adipocytes secrete proteins into the circulation known as adipokines that exert numerous physiological effects. The birth and death of adipocytes and the secretion of adipokines is an area of research currently pursued in the lab.

Cytokines and Glucose Metabolism

Cytokines are circulating proteins produced by cells that deal with the immune response to infection. Cytokines may also play a critical role in glucose metabolism by converging on insulin signaling pathways. Elevated cytokines in insulin resistant states support this hypothesis. Additional support includes the incidence of hypoglycemia associated with parasitic infections. The effect of cytokines on insulin signaling is an area of research currently pursued in the lab.

Insulin Sensitivity and Longevity

Circulating glucose and insulin fluctuate between the fed and fasted state. Low fasting glucose and insulin reflect high sensitivity to insulin. High insulin sensitivity is a distinguishing feature of long-lived people and mice. However, the mechanism by which elevated insulin sensitivity increases longevity is unclear. The changes in glucose metabolism invoked by elevation of insulin sensitivity in long-lived mouse-models are currently pursued in the lab.