Spatio-Temporal Characterization of Cellular Senescence Hallmarks in Experimental Ischemic Stroke

Area of Science:

• Neuroscience
• Cellular Biology
• Pathophysiology

Background:

• Cellular senescence is increasingly recognized in the central nervous system.
• Senescence is a potential, yet uncharacterized, mechanism in ischemic stroke pathophysiology.
• Senolytic drugs are being investigated for neuroprotection.

Purpose of the Study:

• To provide spatio-temporal evidence of brain senescence post-ischemic stroke.
• To identify the specific cell types and pathways involved in stroke-induced senescence.
• To investigate the role of senescence markers including cell cycle arrest, lysosomal activity, SASP, and DNA damage.

Main Methods:

• Male Wistar rats underwent transient middle cerebral artery occlusion (60 min).
• Tissue analysis was performed at 24 hours, and 3, 7, and 14 days post-reperfusion.
• Senescence markers assessed included p16, p21, SA-β-gal, IL-6, IL-1β, TNF, Chk1, Chk2, and LB1.

Main Results:

• Significant p16 expression increase observed in neurons and microglia/macrophages.
• Accumulation of SA-β-gal in infarcted brain tissue.
• Early and significant increases in SASP markers (IL-6, IL-1β, TNF) within 24 hours.
• Alterations in DNA/nuclear damage markers (Chk1, Chk2, LB1) by 14 days.

Conclusions:

• Study findings support the presence of cellular senescence in neurons and microglia/macrophages following ischemic stroke.
• Further research is needed to fully understand senescence's role in stroke pathophysiology.
• Insights gained may aid in developing effective senolytic therapies for stroke.