Suppression of ATM kinase signaling accelerates cellular senescence.

Cells derived from rejuvenated human induced pluripotent stem cells (hiPSCs) require extended culture periods to achieve functional maturation, and it remains difficult to recapitulate cellular senescence in these cells in vitro. This limitation hinders the accurate and efficient modeling of age-related neurodegenerative diseases. Here, we aimed to establish a simple approach to promote neuronal maturation and improve the efficiency of hiPSC-based disease modeling. Using a small-molecule inhibitor library, we identified an ATM kinase inhibitor, KU60019, that promotes both maturation-associated features and senescence-associated phenotypes in hiPSC-derived neurons and fibroblasts. KU60019 treatment promoted the manifestation of disease-relevant phenotypes in hiPSC models of age-related neurodegenerative diseases. Furthermore, senolytic analyses suggested that KU60019-induced senescent cells depend on pro-survival pathways, including HSP90-associated signaling. These findings suggest that KU60019 provides a simple and useful tool for accelerating phenotypic recapitulation in hiPSC models of age-related neurodegenerative diseases.