α1-Adrenergic receptor stimulation induces the expression of receptor activator of nuclear factor κB ligand gene via protein kinase C and extracellular signal-regulated kinase pathways in MC3T3-E1 osteoblast-like cells
α1-Adrenergic receptor stimulation induces the expression of receptor activator of nuclear factor κB ligand gene via protein kinase C and extracellular signal-regulated kinase pathways in MC3T3-E1 osteoblast-like cells
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DOI：
10.1016/j.archoralbio.2007.01.005
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发表时间：
2007-08-01
影响因子：
3
通讯作者：
Abe, Kimio
中科院分区：
文献类型：
--
作者：
Nishiura, Toshihiro;Abe, Kimio
由骨髓基质/成骨细胞产生的核因子受体激活剂Kb配体(RANKL)是破骨细胞形成和骨吸收的重要调节因子。目的：验证成骨细胞通过蛋白激酶C(PKC)和细胞外信号调节激酶(ERK)途径诱导RANKL基因表达的假说。设计：分别用半定量RT-PCR和Western blotting分析小鼠MC3T3-E1成骨样细胞RANKL基因的稳态表达和ERK的激活。苯肾上腺素(α-激动剂)以时间和剂量依赖的方式增加RANKL的mRNA水平。哌唑嗪(α-拮抗剂)可抑制苯肾上腺素诱导的RANKL基因表达，而育亨宾(α(2)-拮抗剂)和心得安(p-拮抗剂)不能抑制RANKL的表达。佛波酯(PMA，PKC激活剂)可促进RANKL基因的表达，而PKC抑制剂GF109203X可抑制苯肾上腺素诱导的RANKL基因表达。苯肾上腺素和PMA均促进ERK的磷酸化，而哌唑嗪和GF109203X则抑制苯肾上腺素诱导的ERK激活。结论：成骨细胞存在α(1b)和α(1d)肾上腺素能受体亚型基因的表达，α(1b)和α(1d)受体亚型基因的表达可能受α(1)肾上腺素能受体刺激的调节。通过激活α(-)(1)肾上腺素能受体诱导RANKL mRNA的表达可能是通过成骨细胞中的PKC和ERK信号通路来实现的。(C)2007爱思唯尔有限公司。保留所有权利。
The receptor activator of nuclear factor KB ligand (RANKL) produced by bone marrow stromal/osteoblast cells is a crucial regulator of osteoclastgenesis and bone resorption. Osteoblastic cells have been demonstrated to express a,-adrenergic receptors.Objective: The purpose of this study was to test the hypothesis that a,-adrenergic receptor stimulation induces the expression of RANKL gene via protein kinase C (PKC) and extracellular signal-regulated kinase (ERK) pathways in osteoblastic cells.Design: The steady-state mRNA levels of RANKL and activation of ERK in mouse MC3T3-E1 osteoblast-like cells were analyzed by semi-quantitative RT-PCR and Western blotting, respectively.Results: In three alpha(1)-adrenergic receptor subtype mRNAs, alpha(1b)- and ald-subtypes were expressed in MCM-E1 cells. The mRNA levels of RANKL were increased by phenylephrine (al-agonist) in time- and dose-dependent manners. Prazosin (a,-antagonist) suppressed the phenylephrine-induced RANKL mRNA expression, but yohimbine (alpha(2)-antagonist) and propranolol (p-antagonist) did not. Phorbol 12-myristate 13-acetate (PMA, PKC activator) increased RANKL mRNA expression and GF109203X (PKC inhibitor) suppressed the phenylephrine-induced RANKL mRNA expression. Both phenylephrine and PMA stimulated the phosphorylation of ERK, while both prazosin and GF109203X inhibited phenylephrine-induced ERK activation. Pretreatment with PD98059 (ERK kinase inhibitor) inhibited both the phosphorylation of ERK and the expression of RANKL gene induced by phenylephrine in MC3T3-E1 cells.Conclusion: These results show that alpha(1b)- and alpha(1d)-adrenergic receptor subtype genes are expressed and the expression of RANKL mRNA may be regulated by alpha(1)-adrenergic receptor stimulation in osteoblastic cells. The induction of RANKL mRNA by activating the alpha(-)(1)adrenergic receptor is probably mediated via PKC and ERK signalling pathways in osteoblastic cells. (C) 2007 Elsevier Ltd. All rights reserved.