Review Volume 11, Issue 21 pp 9947—9959

Figure 2. Summary of the regulation of insulin secretion during the course of aging process. Thyroid hormone (T3) promotes β cell functional maturation via the induction of MafA expression along with p16^Ink4a activation at the early stage of aging. During the progression of aging process, impaired mitochondria function causes KATP channel shutting down and Ca2⁺ influx at the same time, thereby enhancing insulin secretion in a short time frame. In contrast, during the advanced aging process, β cells manifest diminished expression of senescence marker protein-30 (SMP-30) along with deoxysphingolipid accumulation, thereby impeding insulin secretion through unknown mechanisms.