Aging microvasculature: Effects on immune cell trafficking and inflammatory diseases.

Leukocyte recruitment to sites of inflammation is vital for orchestrating an effective immune response. Key to this process is the ability of leukocytes to migrate through venular walls, engaging in sequential interactions with endothelial cells, pericytes, and the venular basement membrane. The aging process exerts profound effects on the molecular and functional properties of the vasculature, thereby influencing the profile and dynamics of leukocyte trafficking during inflammation. In this review, by focusing mainly on neutrophils, we summarize key examples of how the aged microvasculature and perivascular stroma cells promote dysregulated leukocyte-venular wall interactions and present the associated molecular mechanisms. Additionally, we discuss the functional implications of such aberrant leukocyte behavior to age-related and chronic inflammatory pathologies.