The classic receptor for 1alpha,25-dihydroxy vitamin D3 is required for non-genomic actions of 1alpha,25-dihydroxy vitamin D3 in osteosarcoma cells.
1alpha,25-dihydroxy vitamin D3 has a major role in the regulation of the bone metabolism as it promotes the expression of key bone-related proteins in osteoblastic cells. In recent years it has become increasingly evident that in addition to its well-established genomic actions, 1alpha,25-dihydroxy vitamin D3 induces non-genomic responses by acting through a specific plasma membrane-associated receptor. Results from several groups suggest that the classical nuclear 1alpha,25-dihydroxy vitamin D3 receptor (VDR) is also responsible for these non-genomic actions of 1alpha,25-dihydroxy vitamin D3. Here, we have used siRNA to suppress the expression of VDR in osteoblastic cells and assessed the role of VDR in the non-genomic response to 1alpha,25-dihydroxy vitamin D3. We report that expression of the classic VDR in osteoblasts is required to generate a rapid 1alpha,25-dihydroxy vitamin D3-mediated increase in the intracellular Ca(2+) concentration, a hallmark of the non-genomic actions of 1alpha,25-dihydroxy vitamin D3 in these cells.
Bravo
Soraya
S
Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepcion, Chile.
Paredes
Roberto
R
Izaurieta
Pamela
P
Lian
Jane B
JB
Stein
Janet L
JL
Stein
Gary S
GS
Hinrichs
Maria Victoria
MV
Olate
Juan
J
Aguayo
Luis G
LG
Montecino
Martin
M
D000818:Animals; D016678:Genome / Q000235:genetics*; D012516:Osteosarcoma / Q000473:pathology*; D034741:RNA, Small Interfering; D051381:Rats; D018167:Receptors, Calcitriol / Q000378:metabolism*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000378:metabolism
D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol; C118756:dihydroxy-vitamin D3; D014807:Vitamin D