Cellular senescence in ischemic stroke: Cell-type specificity, temporal dynamics, and response to therapeutic...

Increasing experimental and clinical evidence indicates activation of cellular programs resembling senescence and senescence-associated secretory phenotype signaling after stroke. However, a central challenge is definitional: in injured brain tissue, many senescence-associated features overlap with acute stress responses, transient cell-cycle perturbations, and reactive glial or vascular programs, complicating interpretation across models, time points, and cell types. Here, we synthesize the literature using a cell-type-resolved framework spanning acute, subacute, and chronic stroke phases across major neurovascular and immune compartments. Rather than treating senescence as a binary fate, we conceptualize post-stroke senescence-associated biology as a dynamic continuum, in which ischemia-reperfusion stress engages multiple senescence-related domains, only a subset of which may stabilize into durable cell senescence. Accordingly, we emphasize convergent multi-domain evidence with spatial and cell identity resolution, and cautious use of the term "senescence-like" during early injury. Finally, we discuss translational implications through a timing- and safety-aware perspective, arguing that modulation of maladaptive secretory outputs may be superior to cell-elimination strategies in early post-stroke windows. We highlight key biological and clinical uncertainties-including blood-brain barrier dynamics, hemorrhagic and infectious risk, and interference with endogenous repair-that define critical risk gates for evaluating senescence-targeting approaches after stroke.