Potential Involvement of Keratan Sulfate in the Heterogeneity of Microglia

Abstract

Microglia represent a population of resident immune cells in the central nervous system, and activation of microglia has long been considered to contribute to the neuroinflammation. However, recent analyses have indicated that activated microglia are phenotypically and functionally heterogeneous and have various roles in pathophysiological conditions. In addition, ramified microglia, also called “resting microglia”, are heterogeneous and have critical roles in the maintenance of homeostasis in the central nervous system. On the other hand, glycans are synthesized by a combination of multiple glycosyltransferases, and they play important roles in the central nervous system. Accumulating evidence suggests that distribution patterns of glycans in microglia may differ, based on the phenotypes. However, the relationship between microglial functions and glycans remains unclear. In this minireview, we summarize the potential involvement of keratan sulfate in the heterogeneity of microglia.