Abstract
Previously we showed that DNA methyltransferase 3b (Dnmt3b) is required for nerve growth factor (NGF)-induced differentiation of PC12 cells to neuronal phenotype. The present study identified T-cadherin (T-Cad) as one of the targets of Dnmt3b by chromatin immunoprecipitation (ChIP) assay. Combined bisulfite restriction analysis and bisulfite sequencing showed that T-Cad promoter was sparsely methylated in PC12 cells. ChIP-CHOP analysis demonstrated that Dnmt3b is associated with T-Cad promoter irrespective of its methylation status. The mRNA and protein levels of T-Cad were markedly elevated in cells depleted of Dnmt3b by antisense or small interfering RNA. Suppression of T-Cad promoter activity by Dnmt3b was independent of its catalytic activity, which was consistent with the insignificant change in T-Cad promoter methylation status in Dnmt3b-depleted cells. In contrast, deletion of its N-terminal ATRX and PWWP domain abolished its repressor function. Association of histone deacetylase 2 (Hdac2) with T-Cad promoter and restoration of the promoter activity from Dnmt3b-mediated suppression upon treatment with Hdac inhibitor indicated involvement of histone deacetylation in this process. NGF-induced neurite outgrowth was inhibited in a dose dependent manner upon ectopic expression of T-Cad in PC12 cells. Immunofluorescence studies showed that T-Cad was redistributed upon NGF treatment, as evident from its concentration in axon growth cones as opposed to its localization at cell-cell contact region in undifferentiated cells. These results demonstrate a novel role of T-Cad in the NGF-mediated differentiation of PC12 cells to neuronal phenotype.
Highlights
DNA methyltransferase 3b (Dnmt3b) ent with was the iinndsiegpnedinfiadceatnnatt oacfhniatdsncgoaetrainilgyTtiinc-Caaacltdliyvpitrsyou,mwbohmtiecrhitmwteaestdhcyoflnaigstiiusotnr- esethwxepredeorssweionnn-rooefgtduelaantviooavnoilDoafNbDAlnemmfeto3tharyaletnrvdanaDslfnuemraastt1eiDodunnrmi.ntg3bdcifofenrceunrtrieantitownitohf status in Dnmt3bR-deepglaetreddicnegllsF
T-Cad Is a Dnmt3b Target Gene in PC12 Cells—To explore the molecular mechanism of Dnmt3b-mediated differentiation of PC12 cells, we identified the potential targets in these cells
The sequence analysis revealed sparse methylation of CpGs in the proximal promoter region and comparatively dense methylation of CpGs in the exon 1 in both Dnmt3b-depleted cells and vector-transfected control cells (Fig. 2C), which corroborated the COBRA data (Fig. 2B). These results suggest that T-Cad CpG island (CGI) is not heavily methylated in PC12 cells, which is maintained in the absence of Dnmt3b probably by Dnmt1 and/or Dnmt3a
Summary
DNA methyltransferase; CGI, CpG island; Hdac, histone deacetylase; T-Cad, T-cadherin; COBRA, combined bisulfite restrict analysis; ChIP, chromatin immunoprecipitation; PI3K, phosphatidylinositol 3-kinase; TSA, trichostatin A; siRNA, small interfering RNA; NGF, nerve growth factor; RT, reverse transcription; TRITC, tetramethylrhodamine isothiocyanate; GAPDH, glyceraldehyde-3phosphate dehydrogenase. The present study addresses the mechanism by which Dnmt3b suppresses T-Cad expression and the role of T-Cad in NGF-induced differentiation of PC12 cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
