Senolytics as Modulators of Critical Signaling Pathways: a Promising Strategy to Combat Brain Aging and Neurodegenerative Disorders

Aging of the brain, an intricate process, is a significant risk factor for neurodegenerative disorders (NDDs), such as Alzheimer's disease and Parkinson's disease. Senescent cell accumulation is an important hallmark of brain aging. These cells resist apoptotic cell death, produce proinflammatory cytokines, increase oxidative stress, and store toxic proteins that exacerbate neurodegeneration. These senescent cells cause neuroinflammation and dysfunction of the neuronal microenvironment by transmitting senescent phenotypes to neighboring healthy cells. Senolytics have become a viable treatment option to reduce the effects of brain aging since they specifically target and destroy senescent cells. Numerous senolytic compounds, such as dasatinib, fisetin, and quercetin, effectively eliminate senescent cells and reduce the accumulation of harmful substances, including misfolded toxic protein aggregates and reactive oxygen species, thereby helping to maintain tissue homeostasis. These medications aid in reducing oxidative stress and inflammation, two significant factors in brain aging and NDDs, by encouraging the removal of senescent cells. The key molecules involved in this process are mTOR, Nrf2-Keap1, AMPK, and Sirtuin 1 (SIRT1). The modulation of the mTOR and AMPK pathways affects autophagy and cellular metabolism, facilitating the elimination of harmful accumulations and damaged cell organelles. In addition, cellular repair and improved antioxidant defense are encouraged by the activation of the SIRT1 and Nrf2 pathways. The combination of senolytic therapy with these signaling pathways provides a novel approach to attack the cellular and molecular foundations of brain aging and neurodegenerative disorders.