小鼠LCN2蛋白受體在巨噬細胞中所扮演角色之研究

摘要 LCN2為疏水性分子結合蛋白家族的其中一員，同時也是一種急性反應蛋白，可藉由受體媒介的胞吞作用進入細胞內部。目前已知有兩種LCN2的受體（receptor）存在於細胞膜，分別為24p3R及megalin。由本實驗室研究結果已知子宮內膜異位炎形成過程中，腹腔液中的LCN2會有明顯增加的趨勢。而施加LCN2抗體則可以使子宮內膜的異位組織縮小，顯示LCN2在生殖系統中具有重要的功能。根據LCN2運送鐵離子的特性，推測當子宮內膜異位炎的形成過程中，腹腔液中高濃度的LCN2可藉巨噬細胞膜上受體使細胞內部鐵離子的濃度產生變化，進一步誘導細胞分泌細胞激素以促進子宮內膜異位炎的生成。因此本研究希望了解LCN2是否藉由受體媒介的胞吞作用造成巨噬細胞鐵離子的濃度的變化。此外，藉由shRNA的實驗分析巨噬細胞上實際參與反應的受體。在研究中利用手術建立小鼠子宮內膜異位症狀的模式，了解LCN2、24p3R及megalin基因在子宮內膜異位發育時的變化，以便推測LCN2與子通內膜異位症形成的關係。綜合所得結果證實LCN2主要是藉由24p3R將鐵離子帶入巨噬細胞中，而這樣的機制也許與子宮內膜異位的形成有關。而另一受體，Megalin，似乎在巨噬細胞對於LCN2的胞吞作用中並無明顯的功能。

關鍵字

LCN2 ；子宮內膜異位炎； 24p3R ； megalin ；巨噬細胞；急性反應蛋白

並列摘要

Abstract LCN2 belongs to the lipocalin family and performs as an acute phase protein. It can be internalized into the cells via receptor-mediated endocytosis and play a role as an iron transporter. To our knowledge, two LCN2 membrane receptors, 24p3R and megalin, may be in charge of the LCN2 response. According to our previous studies, the level of LCN2 was highly induced in uterus and peritoneal fluid during the development of endometriosis. The administration of LCN2 antibody would diminish the ectopic endometriosis formation. It indicates the significance of LCN2 in reproductive system. LCN2, as an iron-transporter，may activate the macrophage in peritoneal cavity and trigger the secretion of cytokines from macrophage during the endometriosis formation via iron-internalization by LCN2. Currently，we attempt to confirm whether the macrophage can internalize the iron via LCN2 receptor-mediated endocytosis. Furthermore, using shRNA analysis, we identified the real receptor of LCN2 endocytosis in macrophage. The results showed that the iron could be transported the iron into the cell via LCN2-initicated endocytosis, and suggesting the 24p3R is an essential mediator. After establishing a mouse endometriosis model, we examined the gene expressions of LCN2、24p3R and megalin in the possibilities of endometriosis development. The results demonstrated that LCN2 internalized into the macrophage via 24p3R and might be associated with the formation of endometriosis. Megalin seemed to do nothing with LCN2 in macrophage endocytosis and endometriosis formation.

並列關鍵字

LCN2 ； endometriosis ； 24p3R ； megalin ； macrophage ； acute phase protein

參考文獻

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小鼠LCN2蛋白受體在巨噬細胞中所扮演角色之研究

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