September 19, 2019

Microvilli in motion

Live cell imaging studies have revealed that microvilli — finger-like protrusions on the surface of epithelial cells — move and collide as they form the brush border.

The Sept. 9 issue of Developmental Cell featured the research of Matthew Tyska and colleagues on the cover. The image shows microvillar actin protrusions with colors indicating depth relative to the cell surface.

Microvilli are protrusions on the surface of epithelial cells that are dedicated to mechanosensation in the inner ear, and chemosensation and solute uptake in the lungs, gut, intestine and urinary tract. Epithelial cells assemble dense arrays of microvilli called “brush borders” that protect against infections and injury.

Leslie Meenderink, MD, PhD, Matthew Tyska, PhD, and colleagues used live cell imaging to visualize early steps of brush border formation.

They found that individual microvilli exhibit persistent active motility. Driven by actin assembly at the barbed ends of core bundles, microvilli motility allows the protrusions to collide and cluster into highly organized arrays.

The research, featured on the cover of the Sept. 9 issue of Developmental Cell, points to microvillar motility as a previously unrecognized driving force for apical surface remodeling and maturation during epithelial differentiation. These findings provide further insight into the morphogenesis of multiple organ systems.

This research was supported by the National Institutes of Health (grants AI007474, GM008554, HD007502, GM008320, DK111949, DK095811).