2010-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/691149摘要：始基生殖細胞在胚胎發育的初期就開始分化，並隨即依照固定路徑由生成處遷移至性腺發育之性腺脊。雖然學界一向猜測醣胺多醣參與調節始基生殖細胞遷移時期之變化，但一直沒有直接的證據可以證明，本計畫欲針對始基生殖細胞之遷移，研究硫酸乙醯肝素蛋白聚糖在其中所扮演的角色。在先前的研究當中，我們曾證實硫酸乙醯肝素蛋白聚糖 agrin 藉由其硫酸乙醯肝素醣胺多醣，與 Fgf2 共同調節神經軸突的生長，並與 Fgf8 共同 調節視網膜的發育。諸多研究結果也表明 Fgf2 及 Fgf8 在細胞表面作用時，硫酸乙醯肝素醣胺多醣為不可或缺之輔助受器。而一般認為，在始基生殖細胞遷移時期，Fgf2 及 Fgf8 在促使始基生殖細胞存活以及增殖上，相當重要。此外，趨化因子 CXCR4、CXCR7 以及 趨化激素 CXCL12 乃為引導始基生殖細胞之重要因子，而體外實驗亦顯示硫酸乙醯肝素醣胺多醣在 CXCR4/CXCL12 的趨化導引作用中，可能扮演了重要的角色。本計畫有以下三項重要目標：：（1）調查始基生殖細胞在遷移時，硫酸乙醯肝素醣胺多醣參與調控的基因概況，以期對硫酸乙醯肝素醣胺多醣參與的基因調控活動有更全面的了解；（2）轉殖並研究乙醯肝素&#37238;以及硫酸酯&#37238;等與細胞外硫酸乙醯肝素醣胺多醣代謝有關的基因特性，及其在胚胎發育時期之作用；（3）藉由在始基生殖細胞中操控上述基因，以了解硫酸乙醯肝素醣胺多醣在始基生殖細胞遷移中所扮演的角色，包括是否參與遷移路徑引導以及遷移時期之增殖。始基生殖細胞在胚胎發育初期之遷移現象，其中之分子機制雖在近年來多有突破，然其中仍有諸多謎題，且其中牽涉之分子與其他細胞生理、病理現象均多有關連，如趨化因子 CXCR4 即在 HIV 病毒感染及多種癌症細胞轉移中有著相當關鍵的作用。我們希望能藉由本計畫之研究，不但能夠更加深入了解始基生殖細胞遷移之分子機制，同時也能作為探討硫酸乙醯肝素醣胺多醣與這些生物分子之間交互作用的線索。<br> Abstract: Early in embryonic development, primordial germ cells (PGCs) are specified and migrate from the site of their origin, to where gonads develop, following a specific route. It has long been speculated that proteoglycans play a role in regulating this migration. In this research project, the molecular mechanisms involved in PGC migration are proposed to be studied with an emphasis on whether HSPGs are involved in this process. In previous studies, my work demonstrated that Fgf8 signaling in retina development requires the heparan sulfate proteoglycan (HSPG) agrin, and several other evidence lines also indicated that Fgf2 signaling requires heparan sulfate glycosaminoglycan (HS-GAG) as co-receptor. During the migration phase, the survival and proliferation of PGCs require several growth factors, including Fgf2 and Fgf8. Recently, CXCR4/CXCL12/CXCR7 signaling has been reported to be the major pathway that directs PGC migration. This signaling pathway has been reported to be involved in various biological activities, including tumor cell metastasis and HIV-1 viral infection. Furthermore, in vitro evidence showed that heparan sulfate (HS) plays a role in regulating CXCR4/CXCL12 signaling. Three specific aims are proposed as follows: (1) to establish gene expression profiles for migrating PGC with normal or diminished HS; (2) to clone and characterize genes that involve in metabolism of extracellular HS glycosaminoglycans (GAGs) chain including heparanase (HSPE), sulfatase1 (Sulf1), and sulfatase2 (Sulf2); and (3) to evaluate whether HSPGs modulate PGC development during its migration phase in both homing guidance via CXCL12/CXCR4 and survival/proliferation via Fgf2/Fgf8 signaling. The molecules behind PGC migration also involve in a wide variety of biological phenomenon, such as CXCR4 in HIV1 infection and various cancer metastasis. The goal of these studies is to provide novel insight into the molecular mechanisms underlying PGC migration with regards to the HSPGs and hence further elucidate the interactions between HS-GAGs and other molecules such as CXCR4/CXCL12 and Fgf/FGFR.硫酸乙醯肝素蛋白聚糖始基生殖細胞趨化因子纖維母細胞生長因子heparan sulfate proteoglycanglycosaminoglycanprimordial germ cellchimokinefibroblast growth factor