Overexpression of calbindin-D28K in hippocampal progenitor cells increases neuronal differentiation and neurite outgrowth.
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.
Kim
Ju Hee
JH
Department of Biochemistry and Molecular Biology, Hanyang University College of Medicine, Seoul, Korea.
Lee
Jin-A
JA
Song
Young Mok
YM
Park
Chang-Hwan
CH
Hwang
Se-Jin
SJ
Kim
Yong-Seok
YS
Kaang
Bong-Kiun
BK
Son
Hyeon
H
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*
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