Contribution of senescent and reactive astrocytes on central nervous system inflammaging.

Astrocytes, the most predominant cells in the central nervous system (CNS), have well-recognized neuroprotective functions. However, during the CNS aging, astrocytes can become neurotoxic and contribute to chronic inflammation in age-associated brain deterioration and disease. Astrocytes are known to become senescent or reactive due to the exposure to stressful stimuli, in both cases they contribute to an impaired cognitive function through the production of pro-inflammatory mediators. Although both scenarios (senescence and reactive gliosis) have been studied independently, there are no direct studies comparing their secretomes simultaneously in the aging-brain. In this review we discuss the most recent studies in that respect, in order to analyze their simultaneous participation in brain aging.