Senotherapy: A New Horizon for COPD Therapy

There is increasing evidence that COPD is a disease of accelerated lung aging, with the accumulation of senescent cells that lose their ability to repair and secrete multiple inflammatory proteins known as the senescence-associated secretory phenotype (SASP), which mimic the profile of inflammatory mediators secreted in COPD. This review discusses novel drugs (senotherapies) that target cellular senescence and which may be a promising therapeutic approach to prevent currently unaddressed disease progression and mortality in COPD. A major pathway leading to senescence is via the activation of phosphoinositide-3-kinase/mammalian target of rapamycin signaling. Existing drugs, such as rapamycin and metformin, target this pathway. Mitochondrial oxidative stress is a key driving mechanism for this pathway, and mitochondria-targeted antioxidants are promising. A key finding in COPD is loss of antiaging molecules such as sirtuin-1 and sirtuin-6, which are reduced by phosphoinositide-3-kinase/mammalian target of rapamycin signaling through microRNA-34a. Sirtuin activators are in development, and inhibiting microRNA-34a restores sirtuin expression experimentally in COPD cells. Senolytic therapies induce apoptosis and removal of senescent cells and reduce the senescence-associated secretory phenotype response in animal models of aging and in pilot clinical studies of other age-related diseases. A combination of senolytics and senostatics (drugs that inhibit cellular senescence) may be a valuable new approach to COPD, especially if started early in the disease process. Furthermore, COPD is associated with several comorbidities that share the same aging pathways which may be spread by extracellular vesicles, and thus a single treatment for all these diseases is feasible in the future to extend health span.