P2Y6 nucleotide receptors activate NF-κB and increase survival of osteoclasts
P2Y6 nucleotide receptors activate NF-κB and increase survival of osteoclasts
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DOI：
10.1074/jbc.m410764200
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发表时间：
2005-04-29
影响因子：
4.8
通讯作者：
Dixon, SJ
中科院分区：
文献类型：
--
作者：
Korcok, J;Raimundo, LN;Dixon, SJ
在炎症和机械刺激下从细胞中释放的核苷酸通过P2家族的核苷酸受体起作用。先前的研究已经证实P2Y1和P2Y2受体在破骨细胞中表达。本研究的目的是确定破骨细胞P2Y受体是否通过调节破骨细胞发生的关键转录因子NF-kappa B发出信号。免疫荧光检测NF-kappa B的p65亚基，该亚基在活化后从细胞质转移到细胞核。在未处理的兔破骨细胞和暴露于2-甲基硫代ADP （P2Y1激动剂）或ATP或UTP （P2Y2激动剂）的兔破骨细胞中观察到低水平的NF-kappa B活化。相比之下，UDP或INS48823 （P2Y6激动剂）诱导NF-kappa B活化的细胞数量显著增加，这一过程对蛋白酶体抑制剂lactacystin敏感。在通过显微操作纯化的破骨细胞中，逆转录pcr显示P2Y1、P2Y2和P2Y6受体转录物的存在，这些受体的激动剂的应用诱导了细胞质钙的短暂升高。用UDP或INS48823治疗大鼠破骨细胞，而不使用2-甲基硫代ADP或UTP，可提高破骨细胞存活率。骨保护素（RANK配体的诱饵受体）没有显著改变UDP对NF-kappa B定位或破骨细胞存活的影响，与直接作用一致。此外，SN50 （NF-kappa B的细胞渗透性肽抑制剂）抑制了UDP和INS48823诱导的细胞存活增强。我们的研究结果表明，破骨细胞中存在功能性P2Y6受体。因此，核苷酸在炎症和机械刺激部位释放后，可以通过P2Y6受体启动nf - κ B信号传导并提高破骨细胞的存活率。
Nucleotides, released from cells during inflammation and by mechanical stimulation, act through the P2 family of nucleotide receptors. Previous studies have demonstrated the expression of P2Y1 and P2Y2 receptors in osteoclasts. The aim of this study was to determine whether osteoclast P2Y receptors signal through NF-kappa B, a key transcription factor regulating osteoclastogenesis. Immunofluorescence was used to detect the p65 subunit of NF-kappa B, which upon activation translocates from the cytosol to nuclei. Low levels of NF-kappa B activation were observed in untreated rabbit osteoclasts and in those exposed to 2-methylthio ADP ( P2Y1 agonist) or ATP or UTP ( P2Y2 agonists). In contrast, UDP or INS48823 (P2Y6 agonists) induced a significant increase in the number of cells exhibiting NF-kappa B activation, a process sensitive to the proteasome inhibitor lactacystin. In osteoclasts purified by micromanipulation, reverse transcription-PCR revealed the presence of P2Y1, P2Y2, and P2Y6 receptor transcripts, and application of agonists for these receptors induced the transient rise of cytosolic calcium. Treatment of rat osteoclasts with UDP or INS48823, but not 2-methylthio ADP or UTP, increased osteoclast survival. Osteoprotegerin ( a decoy receptor for RANK ligand) did not significantly alter the effects of UDP on NF-kappa B localization or osteoclast survival, consistent with a direct action. Moreover, SN50 (cell-permeable peptide inhibitor of NF-kappa B) suppressed the enhancement of cell survival induced by UDP and INS48823. Our findings demonstrate the presence of functional P2Y6 receptors in osteoclasts. Thus, nucleotides, following their release at sites of inflammation and mechanical stimulation, can act through P2Y6 receptors to initiate NF-kappa B signaling and enhance osteoclast survival.