Protective effects of polysialic acids (PSAs) and its mimics on the nervous system after injury.

Polysialic acid (PSA), a polymer of alpha-2,8 linked sialic acid residues, is a negatively charged macromolecular glycan mainly attached to neural cell adhesion molecules (NCAM). Studies have shown that PSA is not only essential for the development of normal brain circulation, but also for synaptic plasticity, learning and memory in adults. Although the occurrence, features, biosynthesis, and physiological roles of PSA and related effects on related diseases, including schizophrenia, bipolar disorder, neurodegenerative diseases and cancer, have been well reviewed, the important roles of PSA and its mimics in the regeneration of the nervous system following injury have not been well discussed. As a consequence, this article comprehensively reviews the effects of small organic compounds that simulate PSA, such as tegaserod and 5-nonyloxytryptamine (5-NOT), on the nervous system of mammals, suggesting that these mimetics may have tremendous therapeutic potential, especially for strategies aimed at tissue repair after injury of the nervous system. [ABSTRACT FROM AUTHOR]