Clock genes regulate neurogenic transcription factors, including NeuroD1, and the neuronal differentiation of adult neural stem/progenitor cells.
The circadian clock system plays multiple roles in our bodies, and clock genes are expressed in various brain regions, including the lateral subventricular zone (SVZ) where neural stem/progenitor cells (NSPCs) persist and postnatal neurogenesis continues. However, the functions of clock genes in adult NSPCs are not well understood. Here, we first investigated the expression patterns of Clock and Bmal1 in the SVZ by immunohistochemistry and then verified how the expression levels of 17 clock and clock-related genes changed during differentiation of cultured adult NSPCs using quantitative RT-PCR. Finally, we used RNAi to observe the effects of Clock and Bmal1 on neuronal differentiation. Our results revealed that Clock and Bmal1 were expressed in the SVZ and double-stained with the neural progenitor marker Nestin and neural stem marker GFAP. In cultured adult NSPCs, the clock genes changed their expression patterns during differentiation, and interestingly, Bmal1 started endogenous oscillation. Moreover, gene silencing of Clock or Bmal1 by RNAi decreased the percentages of neuronal marker Map2-positive cells and expression levels of NeuroD1 mRNA. These findings suggest that clock genes are involved in the neuronal differentiation of adult NSPCs and may extend our understanding of various neurological/psychological disorders linked to adult neurogenesis and circadian rhythm.
Kimiwada
Tomomi
T
Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
Sakurai
Mikako
M
Ohashi
Hiroki
H
Aoki
Shunsuke
S
Tominaga
Teiji
T
Wada
Keiji
K
D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D001683:Biological Clocks / Q000235:genetics; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D056926:CLOCK Proteins; D002454:Cell Differentiation / Q000235:genetics*; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000235:genetics; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000378:metabolism*; D016548:Prosencephalon / Q000166:cytology / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018874:Spheroids, Cellular; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics*
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D056926:CLOCK Proteins; D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D064231:Nestin; D012333:RNA, Messenger; D015534:Trans-Activators; C538961:Bmal1 protein, mouse; C079240:Mtap2 protein, mouse; C577485:Nes protein, mouse; C501008:Neurod1 protein, mouse; C538944:Clock protein, mouse