Keratan Sulfate Is a Multifunctional Brain Glycosaminoglycan With Instructive Capabilities.

Keratan sulfate (KS) is a glycosaminoglycan (GAG) with unique functions including electroconductive properties that support neurotransmission. KS-proteoglycans contribute to tissue stabilization and functional organization, and have diverse interactive properties with cytokines, growth factors, morphogens, neuregulatory proteins, and neuron receptors that control the formation and function of neural networks. As side chain components of a diverse range of brain proteoglycans, KS assists neural development and axonal guidance, storage and transport of neurotransmitters in synaptic vesicles, neurotransduction, synaptic plasticity, cognition, and memory in perineuronal nets, neuronal proliferation, and differentiation. KS is thus a multifunctional instructive brain GAG with essential roles to play in brain function and homeostasis, with instructive roles in the assembly and repair of functional network structures from secreted molecules produced by glial cells and neurons in the assembly of transmitter and effector receptors and ion channels which affect brain function and neuronal control. KS is a component of neuropils in white matter; however, its specific roles in the function of this tissue have yet to be determined. Dysfunctional KS-mediated cell signaling, however, may predispose to the development of a number of neurological disorders.