查看文章

Increase in intracellular Ca²⁺ concentration occurs by Ca²⁺ influx through the plasma membrane and by Ca²⁺ release from intracellular stores. The ER is the most important Ca²⁺ store. Its stress, characterized by the impairment of Ca²⁺ homeostasis and by the accumulation of misfolded proteins, can be induced by different factors. In turn, it induces defense mechanisms such as unfolded protein response, and when it is severe and prolonged, activation of the apoptotic pathway. Damage to the ER, impairment of its function, and a decreased level of its Ca²⁺-handling proteins might all play a role in physiological ageing by handicapping the ER stress response. Thus, healthy ageing is accompanied by subtle alterations of Ca²⁺ homeostasis and signaling, including alterations in the ER Ca²⁺ load and release. The expression and/or function of ryanodine receptors, IP3 receptors, and SERCA Ca²⁺ pumps located in …