Despite significant strides in acute stroke treatments, ischemic stroke continues to exact a heavy toll on individuals’ quality of life, particularly among older adults in the United States. However, a persistent challenge emerges in the aftermath of successful treatment by reperfusion, as a majority of patients grapple with enduring disability following a stroke. This aftermath, partially driven by ischemia/reperfusion (I/R) injury, is characterized by a robust inflammatory response involving the recruitment of diverse types of white blood cells, led by neutrophils. Abundant evidence underscores the distinction in stroke severity and outcomes across older and younger adults. Because stroke predominantly affects older adults, this work focuses on using mouse models to examine the fundamental differences between young and aged strokes.
The aging process influences leukocyte recruitment and function following stroke and thus likely contributes to these divergent outcomes experienced by young and aged people. Neutrophils, the initial cell type recruited to the brain after I/R injury, have a multifaceted impact whose consequences remain unclear. Emerging insights suggest that these infiltrating neutrophils persist in the brain for an extended period, especially in older adults, possibly exacerbating the I/R injury. This has broad implications and suggests that neutrophils in older adults might possess a predisposition to prolonged activity once they infiltrate the ischemic brain. This understanding opens up neutrophil persistence as a novel therapeutic target following ischemic stroke particularly for older adults.