Neural cell adhesion molecule (NCAM) and polysialic acid–NCAM expression in developing ICR mice

Abstract

Background Coexpression of polysialic acid (PSA)–neuronal cell adhesion molecule (NCAM) with immature neuronal markers is used to indicate the developmental state of neurons generated in the subgranular zone (SGZ) of adult hippocampus. PSA–NCAM is highly expressed throughout the embryonic and juvenile mammalian brain, but heavily downregulated in adult brain. Objective To visualize the expression profiles of NCAM/PSA–NCAM in the dentate SGZ of the hippocampus in developing ICR mice. Methods Cellular distribution, expression, and developmental changes of NCAM/PSA–NCAM were studied in ICR mice at embryonic age 17 days (E17); and similarly at postnatal ages P3, P5, and P7. The SGZ was studied using NCAM and PSA–NCAM immunoreactive staining with or without hematoxylin counterstaining. Western blotting was used to confirm protein expression levels. Results NCAM expression was localized to the surface of neurons and glia and was higher in postnatal mice than it was in embryonic mice. PSA–NCAM was found in cytoplasm and membrane of neural cells, more densely staining in the dentate SGZ at P7, but no staining found at E17. Western blotting of brain tissues also showed expression of both PSA–NCAM and NCAM increased significantly at P5 and P7 compared with expression at P3. Conclusions Progressive increase in NCAM expression occurs in the SGZ during embryogenic and postnatal development. PSA–NCAM was not expressed in embryonic ICR mice, but was increased after birth and highly localized in the SGZ at P7. This NCAM expression pattern in the developing brain indicating structural plasticity and neurogenesis may be useful for study of brain repair.

Neurodevelopmental defects in human cortical organoids with N -acetylneuraminic acid synthase mutation

“…For example, a notable reduction in the amount of spontaneous neuronal activity is present in individuals with autism, leading to a pronounced deficiency in network connectivity ( 52 ). Perturbation of sialic acid levels influences a wide range of brain functions, which are involved in structural plasticity and neurogenesis ( 53 ). In this study, the delayed synaptogenesis in NANS-KO cerebral organoids resulted in reduced synaptic puncta and dysmaturity of the neuronal networks.…”