SLURP-2: A novel cholinergic signaling peptide in human mucocutaneous epithelium
SLURP-2: A novel cholinergic signaling peptide in human mucocutaneous epithelium
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DOI：
10.1002/jcp.20661
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发表时间：
2006-07-01
影响因子：
5.6
通讯作者：
Grando, Sergei A.
中科院分区：
文献类型：
--
作者：
Arredondo, Juan;Chernyavsky, Alexander I.;Grando, Sergei A.
新型胆碱能毒素样信号肽SLURP（分泌型哺乳动物Ly-6/uPAR相关蛋白）在皮肤粘膜上皮中的生物学作用是一个深入研究的课题。先前的研究表明，SLURP-1激活角质形成细胞烟碱乙酰胆碱受体（nAChR）的α 7亚型，并促进角质化和程序性细胞死亡，并且发现SLURP-2的水平在银屑病患者的过度增殖皮肤中上调数倍。在这项研究中，我们首次证明了人表皮和口腔角质形成细胞分泌SLURP-2。我们克隆了人SLURP-2，并产生了小鼠单克隆抗体341 F10 - 1F 12，其在培养中生长的正常人表皮和口腔角质形成细胞的细胞质中显示SLURP-2。在表皮中，SLURP-2被发现主要在基底上室，而在附着的牙龈-在最低的上皮层。重组SLURP-2（rSLURP-2）与烟碱放射性配体竞争结合角质形成细胞，显示出对[H-3]地棘蛙素-比[H-3]尼古丁标记位点更高的亲和力。用rSLURP-2处理显著增加培养中角质形成细胞的数量和它们对凋亡的抵抗力（P < 0.05），这可以被美加明比α-银环蛇毒素更有效地消除。通过实时荧光定量PCR和细胞内western检测，rSLURP-2显著下调分化标志物兜甲蛋白、聚丝蛋白、细胞角蛋白1和10的基因表达，以及细胞外高钙引起的促凋亡蛋白Bax、Bad和caspase 3的表达，rSI-URP-2还消除了喜树碱引起的caspase 3和8的激活。这些结果表明，SLURP-2主要在α 3 nAChR处与乙酰胆碱竞争，并且与SLURP-2的受体连接延迟角质形成细胞分化并防止细胞凋亡。因此，SLURP-1和-2观察到的不同作用可以通过它们与角质形成细胞中表达的nAChR亚型的差异结合来解释。这些发现提出了一种新的模式，粘膜皮肤上皮细胞的生理调节局部产生的小肽样肽分子，并打开新的方向，更好地了解和治疗皮肤和粘膜疾病。
The biologic role of novel cholinergic toxin-like signaling peptides termed SLURP(secreted mammalian Ly-6/uPAR-related protein) in the mucocutaneous epithelium is a subject of intense research. Previous studies demonstrated that SLURP-1 activates the alpha 7 subtype of keratinocyte nicotinic acetylcholine receptors (nAChRs) and facilitates keratinization and programmed cell death, and that the level of SLURP-2 was found to be upregulated several fold in the hyperproliferative skin of patients with psoriasis. In this study, we demonstrated for the first time that human epidermal and oral keratinocytes secrete SLURP-2. We cloned human SLURP-2 and produced the mouse monoclonal antibody 341F10-1F12 that visualized SLURP-2 in the cytoplasm of normal human epidermal and oral keratinocytes grown in culture. In epidermis, SLURP-2 was found predominantly in the suprabasal compartment, whereas in the attached gingiva-in the lowermost epithelial layers. Recombinant SLURP-2 (rSLURP-2) competed with nicotinic radioligands for binding to keratinocytes, showing a higher affinity to the [H-3]epibatidine- than [H-3] nicotine-labeled sites. Treatment with rSLURP-2 significantly (P < 0.05) increased the number of keratinocytes in culture and their resistance to apoptosis, which could be abolished by mecamylamine more efficiently than a-bungarotoxin. By real-time PCR and in-cell western, rSLURP-2 significantly (P < 0.05) downregulated gene expression of the differentiation markers loricrin, filaggrin, and cytokeratins 1 and 10, and pro-apoptotic Bax, Bad, and caspase 3 which were elevated by high extracellular calcium, and rSI-URP-2 also abolished activation of caspases 3 and 8 caused by camptothecin. These results indicated that SLURP-2 competes with acetylcholine predominantly at the alpha 3 nAChR and that receptor ligation with SLURP-2 delays keratinocyte differentiation and prevents apoptosis. Thus, the different effects observed for SLURP-1 and -2 can be explained by their differential binding to the nAChR subtypes expressed in keratinocytes. These findings present a novel paradigm of the physiologic regulation of mucocutaneous epithelial cells by locally produced small hormone-like peptide molecules, and open novel directions toward better understanding and treating of skin and mucosal diseases.