2014-10-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/643732摘要：第三號誘餌受體（DcR3 蛋白）為可溶性受體，屬於腫瘤壞死因子受體（TNFR）家族成員，可做為發炎反應的生物標誌。DcR3 於1998 年在腫瘤組織中被發現，目前研究已知DcR3 在數種腫瘤組織細胞中會有高表現。研究發現血液中DcR3 的濃度若偏高可作為癌症患者的不良癒後指標。研究並指出腫瘤細胞中DcR3 蛋白的表現，可以藉由中和FasL，LIGHT 和TL1A 的反應，幫助腫瘤細胞逃避宿主的免疫監視防護作用。除了原先中和配體的作用外，DcR3 亦可通過與硫酸乙酰肝素蛋白多糖（多糖蛋白HSPGs）的結合以執行其非誘餌多功能的操作，進而調節巨噬細胞，樹突狀細胞和破骨細胞的活化和分化。最近，我們也發現DcR3 蛋白也和皮膚發炎有關的牛皮癬(psoriasis)息息相關，EGF 以及各種發炎性細胞因子活化皮膚角質形成細胞時可增加DcR3 蛋白的表現。此外，我們的研究發現DcR3 蛋白在牛皮癬病變部位會大量表現，且DcR3 蛋白能抑制角質形成細胞的分化，這分化作用是正常的皮膚角質化的關鍵過程。半乳糖凝集素(Galectins)屬於一類可和特異性的β-半乳糖苷糖如N-乙酰基乳糖胺（Galβ1-3GlcNAc 或Galβ1-4GlcNAc）結合的蛋白質，半乳糖凝集素是藉由以N-或O-的連接方式將糖基結合到蛋白質中將蛋白質糖基化。近年的研究特別指出，半乳糖凝集素為具有多功能的分子，在細胞內外皆有作用。目前已知galectin-3 具有調節免疫細胞活性，因而會影響腫瘤發生的作用，也和發炎相關的皮膚病如牛皮癬有關。有趣的是我們的初步的研究發現，DcR3 蛋白和galectin-3 在原生性的人體正常角質形成細胞(NHEK）和小鼠骨髓來源的巨噬細胞（BMDM）的細胞質中會發生交互結合的作用。我們還觀察到，在角質形成細胞中當galecin-3 剔除減少時，DcR3 蛋白的表現量也會減少。在本研究計劃中，我們將探討這兩種糖結合蛋白質在角質形成細胞及巨噬細胞在中由細胞內作用產生的功能。也將探討這兩種糖結合蛋白質各自在細胞分化及誘導發炎反應訊息傳遞作用的標靶分子及其調控，並進ㄧ步評估此二分子對調節角質形成細胞分化和巨噬細胞功能的分子調控機制。本計劃的具體研究目標包括：（1）了解在角質形成細胞和巨噬細胞中DcR3 和galectin-3 蛋白質分子構造上的結合部位，以及此二分子在細胞內結合的區域和相關的訊息調控分子;（2）闡明DcR3 和galectin-3 蛋白在角質形成細胞的分化和生長的調控;（3）了解在巨噬細胞活化作用中DcR3 和galectin-3 蛋白所扮演的角色。<br> Abstract: Decoy receptor 3 (DcR3) is a soluble receptor belonging to tumor necrosis factor receptor(TNFR) superfamily as well as an inflammation biomarker. Since its discovery in cancertissues in 1998, accumulating studies demonstrate high expression of DcR3 in variouslineages of malignant tissues. High DcR3 serum level has been established as a poorprognostic index of cancer patients. Tumor cells expressing DcR3 has been speculated to helptumor cells to escape host immunosurveillance via its neutralizing action on FasL, LIGHT,and TL1A. Besides exerting ligand neutralization effects, DcR3 acts as an effector moleculeto execute its non-decoy multifunctional actions via interacting with heparan sulfateproteoglycans (HSPGs), thus modulate the activation and differentiation of macrophages,dendritic cells, and osteoclasts. Recently we also demonstrate the role of DcR3 ininflammation-associated psoriasis, which can be upregulated by EGFR signaling and variousproinflammatory cytokines in keratinocytes. Moreover, we show that DcR3 is increased inpsoriatic lesions, and DcR3 can inhibit keratinocyte differentiation, which is a key process fornormal skin cornification. Galectins are a family of proteins defined by their bindingspecificity for β-galactoside sugars, such as N-acetyllactosamine (Galβ1-3GlcNAc orGalβ1-4GlcNAc), which can be bound to proteins by either N-linked or O-linkedglycosylation. Recent work highlights galectin-3 is a multifunctional molecule which canfunction both inside and outside the cells. Galectin-3 has been shown to regulate immune cellactivities, induce immunosuppression in tumorigenesis, and involve in the pathogenesis ofinflammatory skin diseases including psoriasis. Intriguingly our preliminary work indicatesthe interaction of DcR3 and galectin-3 in the cytosol of primary human normal keratainocytes(NEHK) and mouse bone marrow-derived macrophages (BMDM). We also observed thatDcR3 expression in kerationocytes is attenuated when galecin-3 is knocked down. In thisproject, we are going to explore the intracellular functions of both glycans-binding proteins inkeratinocytes and macrophages. We will dissect their respective intracellular targets to controlsignaling pathways for inducing inflammation responses and cell differentiation, and clarifythe molecular interactive features which contribute to regulate cellular functions ofkeratinocytes and macrophages. The specific aims of this project include (1) To understandthe binding motifs between DcR3 and galectin-3, intracellular localization and bindingregulators in keratinocytes and macrophages; (2) To understand the roles of DcR3 andgalectin-3 in keratinocyte differentiation and growth; (3) To understand the roles of DcR3 andgalectin-3 in macrophages activation.