Suppression of MeCP2beta expression inhibits neurite extension in PC12 cells.
Regulation of gene expression is critical to the proper development of neuronal cells. The methyl-CpG binding protein 2 (MeCP2) operates as a transcriptional repressor by facilitating histone deacetylation and DNA methylation-dependent transcriptional silencing. This study examined the importance of MeCP2 in the regulation of neurite formation in PC12 cells. Expression of MeCP2 increased in a time-dependent manner after induction of neuronal differentiation. Expression was assessed at both the transcriptional and translation levels, and reached a maximum at 24 h post-induction. In addition, a marked inhibition of neurite extension and proper localization of a marker for synapse formation, synapsin I, were observed when MeCP2 expression was decreased by the addition of an antisense morpholino oligomer directed to the translational initiation site for MeCP2beta. The removal of the antisense oligomer allowed neurite extension to progress. However, the addition of antisense oligomer to previously differentiated PC12 cells did not affect established neurite processes. Taken collectively, our results indicate a role for MeCP2beta early in the events of neurite formation and that the relative levels of MeCP2alpha and MeCP2beta may be different in early differentiating neurons than is found in the adult brain. In addition, unique functions may exist for the two isoforms of MeCP2. Our results indicate that the inhibition of neurite elaboration caused by a reduction in MeCP2 may be reversible.
Cusack
Sorcha M
SM
Department of Biology, Boise State University, Boise, ID 83725, USA.
Rohn
Troy T
TT
Medeck
Ryan J
RJ
Irwin
Katey M
KM
Brown
Raquel J
RJ
Mercer
Linda M
LM
Oxford
Julia Thom
JT
D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation; D051783:Methyl-CpG-Binding Protein 2; D016501:Neurites / Q000502:physiology*; D009474:Neurons / Q000187:drug effects*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D016716:PC12 Cells; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016704:Synapsins / Q000378:metabolism; D014158:Transcription, Genetic
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C497394:Mecp2 protein, rat; D051783:Methyl-CpG-Binding Protein 2; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D012097:Repressor Proteins; D016704:Synapsins