When normal cells lose their ability to replicate, they become senescent cells. Over time, senescent cells accumulate in aging tissues, spewing off a cocktail of inflammatory and growth factors, as well as enzymes that break down surrounding tissue and cause inflammation. This cocktail is the “senescence-associated secretory phenotype” or SASP. Senescent cells – and the downstream impact of the SASP – are now implicated in a remarkable litany of the diseases of aging.

On a more encouraging note, multiple studies have now documented that senolytic drugs and gene therapies that destroy senescent cells exert sweeping rejuvenating effects in aging, both in laboratory animals and animal models of multiple diseases of aging. In theory, however, senolytic therapies shouldn’t be necessary. The body’s immune system is on continuous patrol against senescent cells: our natural killer (NK) cells recognize senescent cells as abnormal, bind to them, and release substances that trigger the senescent cells to self-destruct.

An SRF-donor-funded collaboration between Dr. Judith Campisi’s lab at the Buck Institute and the SRF Research Center seeks to discover why senescent cells accumulate with age, and what might we do to enhance immune surveillance and elimination of these cellular saboteurs?