Parathyroid hormone induces receptor activity modifying protein-3 (RAMP3) expression primarily via 3',5'-cyclic adenosine monophosphate signaling in osteoblasts.
Parathyroid hormone induces receptor activity modifying protein-3 (RAMP3) expression primarily via 3',5'-cyclic adenosine monophosphate signaling in osteoblasts.
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甲状旁腺激素主要通过成骨细胞中的 3,5-环单磷酸腺苷信号传导诱导受体活性修饰蛋白 3 (RAMP3) 表达。
DOI：
10.1007/s00223-004-0239-1
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Nervina,JM
中科院分区：
文献类型：
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作者：
Phelps,E;Bezouglaia,O;Tetradis,S;Nervina,JM
甲状旁腺激素（PTH）对骨具有显著的合成代谢和分解代谢作用。我们假设PTH诱导的初级反应基因是成骨细胞功能的重要决定因素。PTH通过PTHR 1诱导成骨细胞基因表达，PTHR 1是一种触发环磷酸腺苷（cAMP）-蛋白激酶A（PKA）、蛋白激酶C（PKC）和钙信号传导的七螺旋受体。通过代表性差异分析，我们发现受体活性修饰蛋白3（RAMP 3）是PTH诱导成骨细胞的主要反应基因。RAMP 3是一种辅助激活因子，指导降钙素受体（CTR）和CTR样受体（CRLR）糖基化、运输和配体结合特异性。我们的目的是表征原代小鼠成骨细胞（MOB）中PTH诱导的RAMP 3信使核糖核酸（mRNA）水平，并确定哪种信号通路介导这种效应。10 nM PTH在4小时时最大程度地诱导MOB中的RAMP 3 mRNA水平。用3 μg/mL放线菌酮抑制蛋白质合成不影响PTH诱导的RAMP 3 mRNA水平。用10 μM佛司可林（FSK）和1 μM佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）选择性激活cAMP-PKA信号和PKC信号显著增加RAMP 3 mRNA水平，而1 μM离子霉素（钙离子载体）没有影响。用30 μM PKA抑制剂H89预处理显著阻断PTH和FSK诱导的RAMP 3 mRNA水平。用1 μM PMA预处理（可耗竭PKC）对PTH和FSK诱导的RAMP 3 mRNA水平无影响，但可阻断PMA诱导的RAMP 3 mRNA水平。100 nM PTH（3-34）可激活PKC和钙，但不激活PKA，对RAMP 3 mRNA水平无影响。这些发现表明，RAMP 3是PTH诱导的原发性MOB中的原发性应答基因，并且PTH主要通过cAMP-PKA途径调节RAMP 3基因表达。
Parathyroid hormone (PTH) has significant anabolic and catabolic effects on bone. We hypothesize that PTH-induced primary response genes are important determinants of osteoblast function. PTH induces osteoblastic gene expression through PTHR1, a heptahelical receptor that triggers cyclic adenosine monophosphate (cAMP)–protein kinase A (PKA), protein kinase C (PKC), and calcium signaling. By using representational difference analysis we found that receptor activity modifying protein-3 (RAMP3) is a PTH-induced primary response gene in osteoblastic cells. RAMP3 is a coactivator that directs calcitonin receptor (CTR) and CTR-like receptor (CRLR) glycosylation, trafficking, and ligand-binding specificity. Our purpose was to characterize PTH-induced RAMP3 messenger ribonucleic acid (mRNA) levels in primary mouse osteoblasts (MOBs) and to determine which signaling pathway mediates this effect. 10 nM PTH maximally induced RAMP3 mRNA levels in MOBs at 4 hours. Protein synthesis inhibition with 3 μg/mL cycloheximide did not affect PTH-induced RAMP3 mRNA levels. Selective activation of cAMP-PKA signaling with, 10 μM forskolin (FSK) and PKC signaling with 1 μM phorbol 12-myristate 13-acetate (PMA) significantly increased RAMP3 mRNA levels, whereas 1 μM ionomycin (a calcium ionophore) had no effect. Pretreatment with 30 μM H89, a PKA inhibitor, significantly blocked PTH- and FSK-induced RAMP3 mRNA levels. Pretreatment with 1 μM PMA, which depletes PKC, had no effect on PTH- and FSK-induced RAMP3 mRNA levels but blocked PMA-induced RAMP3 mRNA levels. 100 nM PTH (3-34), which activates PKC and calcium but not PKA, had no effect on RAMP3 mRNA levels. These findings indicate that RAMP3 is a PTH-induced primary response gene in primary MOBs and that PTH regulates RAMP3 gene expression primarily through the cAMP-PKA pathway.