1α,25 dihydroxi-vitamin D3 modulates CDK4 and CDK6 expression and localization

Autor: Ana Paula Irazoqui, Ricardo Boland, Claudia Buitrago, Nadia B. Heim
Rok vydání: 2015
Předmět:
Zdroj: Biochemical and Biophysical Research Communications. 459:137-142
ISSN: 0006-291X
DOI: 10.1016/j.bbrc.2015.02.083
Popis: We recently reported that the vitamin D receptor (VDR) and p38 MAPK participate in pro-differentiation events triggered by 1α,25(OH)2-vitamin D3 [1,25D] in skeletal muscle cells. Specifically, our studies demonstrated that 1,25D promotes G0/G1 arrest of cells inducing cyclin D3 and cyclin dependent kinases inhibitors (CKIs) p21Waf1/Cip1 and p27Kip1 expression in a VDR and p38 MAPK dependent manner. In this work we present data indicating that cyclin-dependent kinases (CDKs) 4 and 6 also play a role in the mechanism by which 1,25D stimulates myogenesis. To investigate VDR involvement in hormone regulation of CDKs 4 and 6, we significantly reduced its expression by the use of a shRNA against mouse VDR, generating the skeletal muscle cell line C2C12-VDR. Investigation of changes in cellular cycle regulating proteins by immunoblotting showed that the VDR is involved in the 1,25D -induced CDKs 4 and 6 protein levels at 6 h of hormone treatment. CDK4 levels remains high during S phase peak and G0/G1 arrest while CDK6 expression decreases at 12 h and increases again al 24 h. The up-regulation of CDKs 4 and 6 by 1,25D (6 h) was abolished in C2C12 cells pre-treated with the ERK1/2 inhibitor, UO126. Moreover, CDKs 4 and 6 expression induced by the hormone nor was detected when α and β isoforms of p38 MAPK were inhibited by compound SB203580. Confocal images show that there is not co-localization between VDR and CDKs at 6 h of hormone treatment, however CDK4 and VDR co-localizates in nucleus after 12 h of 1,25D exposure. Of relevance, at this time 1,25D promotes CDK6 localization in a peri-nuclear ring. Our data demonstrate that the VDR, ERK1/2 and p38 MAPK are involved in the control of CDKs 4 and 6 by 1,25D in skeletal muscle cells sustaining the operation of a VDR and MAPKs -dependent mechanism in hormone modulation of myogenesis. Fil: Irazoqui, Ana Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina Fil: Heim, Nadia B.. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina Fil: Boland, Ricardo Leopoldo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina Fil: Buitrago, Claudia Graciela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina
Databáze: OpenAIRE
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