title: Overexpression of calbindin-D28K in hippocampal progenitor cells increases neuronal differentiation and neurite outgrowth.
abstract: Excitatory stimuli are known to be a potent regulator for induction of neuronal differentiation. Calbindin-D28K buffers intracellular Ca2+ and modifies synaptic functions in neurons. However, the effects of calbindin-D28K on the regulation of activity-induced neuronal differentiation and related biochemical modifications remain unsolved. In the present study, by a gain-of-function study with retroviral vector system and dicer-generated small interfering RNA (d-siRNA) to effectively knock down the expression of calbindin-D28K, we demonstrated that calbindin-D28K at a physiologically relevant level promoted neuronal differentiation and neurite outgrowth. Increase of neuronal differentiation by calbindin-D28K overexpression was concurrent with the expression of basic helix-loop-helix (bHLH) transcriptional factors, phosphorylation of calcium and calmodulin-dependent protein kinase II (CaMKII) and NeuroD at Ser(336). KN-62, a highly specific CaMKII inhibitor, blocked the up-regulation of proneural bHLH genes, p-CaMKII, and pSer(336)NeuroD. Calbindin-D28K appeared to facilitate neuronal differentiation of both fetal and adult hippocampal progenitor cells. Together, these findings establish the novel calbindin-regulated function of CaMKII and NeuroD in control of neuronal differentiation and neurite outgrowth.
authors.affiliation: Department of Biochemistry and Molecular Biology, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Ju Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Jin-A
authors.initials: JA
authors.lastname: Lee
authors.forename: Young Mok
authors.initials: YM
authors.lastname: Song
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Park
authors.forename: Se-Jin
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Kim
authors.forename: Bong-Kiun
authors.initials: BK
authors.lastname: Kaang
authors.forename: Hyeon
authors.initials: H
authors.lastname: Son
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D064092:Calbindin 1; D064026:Calbindins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D051792:Basic Helix-Loop-Helix Proteins; D064092:Calbindin 1; D064026:Calbindins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002762:Cholecalciferol; D009419:Nerve Tissue Proteins; D064030:S100 Calcium Binding Protein G; C576500:Calb1 protein, rat; C093564:Neurogenic differentiation factor 1; C063302:KN 62