Live imaging of vascular dynamics in mouse skin.

The cutaneous vascular network, located in the skin dermis, plays vital roles in thermoregulation, immune surveillance, and tissue regeneration. Despite its important functions, the cutaneous vasculature remains an understudied component of the skin. This article outlines approaches for intravital 2-photon microscopy to visualize and track vascular dynamics in mouse skin, particularly the hind paw, which offers a simplified, hairless model for longitudinal imaging. Utilizing genetically encoded fluorescent reporters, endothelial cells can be selectively and dynamically labeled to study vascular remodeling events that occur over the time frame of days to weeks, necessitating longitudinal approaches to capture the dynamics and resolution of these processes. Mosaic labeling approaches enable the tracking of single cells within the context of the remodeling network, allowing for an understanding of cellular behaviors that drive remodeling events. Intravital imaging also provides an opportunity to visualize and measure vascular function such as hemodynamics and barrier function. Collectively, these techniques provide powerful tools to dissect postnatal vascular development, adult homeostatic maintenance, and response to injury and holds potential for the interrogation of fundamental aspects of vascular biology as well as the understanding of cutaneous pathologies that involve the vasculature.