title: Effect of nano-hydroxyapatite on the axonal guidance growth of rat cortical neurons.
abstract: Nanomaterials such as carbon nanotubes (CNT) can improve axonal connecting in a target direction during regeneration, however, it is limited by the neurotoxicity of CNT. Here we investigate the possible protective effect of nano-hydroxyapatite (n-HA) against nerve injury, as well as CNT in cultured rat cortical neurons. In this study the nanomaterials were characterized by X-Ray diffractometry (XRD) and atomic force microscopy (AFM) analysis. Our results showed that axonal migration and extension were increased significantly after n-HA treatment by immunocytochemistry assay. The patch clamp assay results showed that n-HA acts protectively after nerve injury, which inhibited the average amplitude and frequency of excitatory postsynaptic currents (EPSCs). n-HA is not neurotoxic for the electrophysiology activity of cells. To find the effect of n-HA on axonal guidance growth in the cultured cortical neurons, Netrin 1, one of the axonal guidance cues, was determined by RT-PCR and western blot assay. Compared to the control group, n-HA down-regulated the mRNA level of netrin 1, and moreover, the expression of netrin 1 decreased significantly in the cells. n-HA caused the axonal guidance growth to be mediated by netrin 1 during nerve regeneration. Therefore, the data from the present study provided a new approach for the therapy or prevention of nerve injury.
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
authors.forename: Meili
authors.initials: M
authors.lastname: Liu
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Haifeng
authors.initials: H
authors.lastname: Liu
authors.forename: Xufeng
authors.initials: X
authors.lastname: Niu
authors.forename: Yubo
authors.initials: Y
authors.lastname: Fan
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D002478:Cells, Cultured; D017886:Durapatite / Q000494:pharmacology*; D037742:Nanotubes, Carbon / Q000737:chemistry; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism; D009416:Nerve Regeneration / Q000187:drug effects; D000075388:Netrin-1; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D037742:Nanotubes, Carbon; D009414:Nerve Growth Factors; C000617354:Ntn1 protein, rat; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D000075388:Netrin-1; D017886:Durapatite