2014-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/687870摘要：水解磷酸脂是一種結構簡單的分子，藉活化不同水解磷酸脂受器 1-6，以調控諸多生理 作用。本實驗室於先前研究顯示，水解磷酸脂受器３參與紅血球分化之調控。於初步 實驗結果中顯示，除了紅血球生成之外，水解磷酸脂受器２／３也在血小板生成過程 中扮演重要角色。在血液幹細胞分化過程中，紅血球與血小板於分化上游有共同祖細 胞，經分化後衍生出的兩個分支。人類 K562 細胞於適當刺激下，可表達出人類巨細胞 標記基因，因而可被視為巨細胞分化之研究模式。在施加水解磷酸脂受器２促進劑後， 血小板分化受到抑制；而在施加水解磷酸脂受器３促進劑之下，血小板分化增強。此 外，以核糖核酸干擾抑制水解磷酸脂受器２表達後，血小板分化基因表現上升；而抑 制水解磷酸脂受器３之後，血小板分化基因表現下降。這些結果顯示，水解磷酸脂受 器２與３對血小板分化具有拮抗的調控作用。在此計劃中，我們預計分別於人類 K562 細胞株與人類胚胎幹細胞中，過度表現或抑制水解磷酸脂受器基因，以檢視血小板分 化過程。而動物實驗方面，預計以血小板表現綠螢光蛋白之基因轉殖斑馬魚與水解磷 酸脂受器基因剔除斑馬魚，進一步觀察血小板生成所受到之影響。這些研究結果應可 對血小板相關疾病治療提供重要背景知識。<br> Abstract: Lysophosphatidic acid (LPA) is a structurally simple lysophospholipid. It acts as an extracellular signaling molecule activates various G protein coupled receptors, LPA1-6. In our previous studies, we demonstrated that LPA3 participated during erythropoiesis processes in both human hematopoietic stem cells and zebrafish model. Moreover, our preliminary results implied that both LPA2 and LPA3 are involved during thrombocyte differentiation, megakaryopoiesis, which shares a common progenitor with erythropoiesis in hematopoietic lineage. By using K562 cell, a myelogenous leukemia cell line expresses lineage specific markers upon stimulus, we found that treatment with LPA2 agonist, MDP, inhibited the expression of megakaryopoietic markers. In contrast, LPA3 agonist, OMPT, enhanced megakaryopoiesis. In addition, LPA2 shRNA treatment enhanced the expression of megakaryopoietic markers, while LPA3 shRNA treatment decreased their expression. These consistent results strongly suggested a contrary effect of LPA2 and LPA3 during thrombocyte differentiation. In this proposal, we attempt to overexpress and knockdown LPA receptors in K562 cells and hHSCs to examine the megakaryopoiesis processes in vitro. In addition, we will also investigate the effects of LPA receptors in CD41-GFP transgenic zebrafish. These results should clarify the roles of LPA receptors during megakaryopoiesis processes and provide important background information for potential treatment for diseases such as megakaryopenia.