Microglia reactivity entails microtubule remodeling from acentrosomal to centrosomal arrays.

Microglia reactivity entails a large-scale remodeling of cellular geometry, but the behavior of the microtubule cytoskeleton during these changes remains unexplored. Here we show that activated microglia provide an example of microtubule reorganization from a non-centrosomal array of parallel and stable microtubules to a radial array of more dynamic microtubules. While in the homeostatic state, microglia nucleate microtubules at Golgi outposts, and activating signaling induces recruitment of nucleating material nearby the centrosome, a process inhibited by microtubule stabilization. Our results demonstrate that a hallmark of microglia reactivity is a striking remodeling of the microtubule cytoskeleton and suggest that while pericentrosomal microtubule nucleation may serve as a distinct marker of microglia activation, inhibition of microtubule dynamics may provide a different strategy to reduce microglia reactivity in inflammatory disease. [Display omitted] • Reactive microglia dramatically remodel their microtubule cytoskeleton • Golgi outposts nucleate acentrosomal microtubules in homeostatic microglia • Control of microtubule dynamics enables proper cytokine release in reactive microglia Rosito et al. find that in microglia cells, the transition between homeostatic and reactive states is characterized by a dramatic reorganization of the microtubule cytoskeleton from a Golgi-outpost-nucleated acentrosomal array to a pericentrosomal radial array to enable proper cytokine release. [ABSTRACT FROM AUTHOR]