Seminars

1D confinement controls cell shape and migration

Pericytes are mural cells of the microvasculature, they wrap around small vessels, support the vessels mechanically and participate in blood flow regulation.

Pericytes are distinguished by two main characteristics ; first their distinct morphology, which has been likened to a “bump on a log”, as they present long processes spanning along the axis of the vessels they adhere to, and a protruding soma that houses the nucleus. The second characteristic is their distribution along the microvascular tree in a cellular chain where each cell occupies its own territory. This spatial distribution is established by cell migration during the embryonic stage and maintained through controlled motility in the adult.

Because of their position in the microvascular tree, pericytes experience extreme lateral and longitudinal confinement, we hypothesize that the confinement impacts their morphology. Although pericyte shape is key for their function during vascular regulation, the manner in which pericyte morphology is associated with migration and function remains unknown.

In this project, we use micropatterns to mimic pericyte adhesion to microvessels, we show that lateral confinement controls cell shape and produces in vivo-like phenotypes. We study pericyte migration on both laterally confining lanes, and longitudinally constraining motifs and propose a model that describes their kinetics as a stochastic motion with dry friction.

In vivo pericytes can bridge nearby capillaries, we show that in vitro pericytes are also capable of crossing gaps of different sizes. The percentage of crossings is correctly predicted by the likelihood of a fluctuating system to overcome an energy barrier. Our joint experimental and theoretical approach demonstrates the effect of in vivo-like geometrical confinement on pericyte morphology and migration.