RRC ID 19300
著者 Nakao Y, Koike T, Ohta Y, Manaka T, Imai Y, Takaoka K.
タイトル Parathyroid hormone enhances bone morphogenetic protein activity by increasing intracellular 3', 5'-cyclic adenosine monophosphate accumulation in osteoblastic MC3T3-E1 cells.
ジャーナル Bone
Abstract Intermittent subcutaneous injections of parathyroid hormone (PTH) increase bone mass in a variety of animal models and humans. The anabolic actions of PTH on osteogenic cells are mainly mediated through the protein kinase A (PKA) signaling pathway via PTH receptor 1 (PTHR1). We have already reported 3', 5'-cyclic adenosine monophosphate (cAMP)/PKA-mediated enhancement of bone morphogenetic protein (BMP) signaling. Herein, we focused on the involvement of PTH in BMP signaling pathways in the MC3T3-E1 mouse osteoblastic cell line, to elucidate a potential mechanism of the anabolic actions of PTH on bone formation. Elevation of intracellular cAMP level in MC3T3-E1 cells by addition of PTH (10(-7) M) to culture media was transient without significant effect on biological actions of BMP. Cyclic addition of PTH (10 cyclic additions of 10(-8) M PTH at 3-min intervals) maintained a high intracellular cAMP level for about 2 h and mRNA expression and enzymatic activity of alkaline phosphatase (ALP) by BMP was enhanced by this addition. Relative luciferase expression assay in MC3T3-E1 cells using the Id1 promoter, an early response gene to BMPs, enhanced elevation of transcriptional activity in response to recombinant human BMP-2 by concomitant addition of PTH and BMP. Furthermore, cyclic PTH treatment significantly further suppressed BMP-induced inhibitory Smad6 expression. H89 (PKA inhibitor) almost completely abolished PTH actions on BMP signaling. IBMX (phosphodiesterase inhibitor) enhanced PTH actions. These results suggest that PTH enhances BMP signaling when PTH-induced intracellular cAMP level is maintained for a few hours, accelerating BMP actions to promote osteoblastic function and anabolic actions of new bone formation.
巻・号 44(5)
ページ 872-7
公開日 2009-5-1
DOI 10.1016/j.bone.2009.01.370
PII S8756-3282(09)00397-4
PMID 19442611
MeSH Alkaline Phosphatase / genetics Animals Bone Morphogenetic Protein 2 Bone Morphogenetic Proteins / pharmacology Cell Line Core Binding Factor Alpha 1 Subunit / genetics Cyclic AMP / metabolism* Mice Osteoblasts / drug effects* Osteoblasts / metabolism* Osteocalcin / genetics Parathyroid Hormone / pharmacology* Recombinant Proteins / pharmacology Reverse Transcriptase Polymerase Chain Reaction Signal Transduction / drug effects Smad6 Protein / genetics Transforming Growth Factor beta / pharmacology
IF 4.147
引用数 32
WOS 分野 ENDOCRINOLOGY & METABOLISM
リソース情報
ヒト・動物細胞 MC3T3-E1(RCB1126)