請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/70997
標題: | GCM1及DLX3調控胎盤中PGF基因機制之探討 Regulation of PGF gene expression by GCM1 and DLX3 in placenta |
作者: | Ming-Ren Yang 楊明仁 |
指導教授: | 陳宏文(Hung-Wen Chen) |
關鍵字: | GCM1,DLX3,PGF,胎盤, GCM1,DLX3,PGF,Placenta, |
出版年 : | 2018 |
學位: | 碩士 |
摘要: | 在人類胎盤滋養層細胞(Trophoblast cell)的發育中,GCM1 (Glial cells missing 1)轉錄因子扮演著極重要的角色,GCM1會藉由啟動下游不同的目標基因促使細胞性滋養層細胞(Cytotrophoblast, CTB)分化成融合滋養層細胞(Syncytiotrophoblast, STB)以及絨毛外滋養層細胞(Extravillous trophoblasts, EVT),同時也會影響到賀爾蒙的分泌等。cAMP/PKA此一訊息傳遞路徑會影響GCM1的轉錄活性,且可以藉由毛喉素(Forskolin)去啟動cAMP/PKA的路徑而強化GCM1的轉錄活性。胎盤生長因子(Placental growth factor, PGF)也是GCM1的目標基因之一,PGF屬於血管內皮生長因子(Vascular endothelial growth factor)家族的一員,在懷孕早期以及胎盤早期的發育之中也佔有一席之地。子癲前症(Preeclampsia)為一常見之孕婦疾病,其臨床症狀為蛋白尿及高血壓,在之前文獻指出子癲前症的患者中發現PGF在胎盤及血液中的表現量有明顯的降低。
屬於同源異型盒(Homeobox)家族的DLX3 (Distal-less 3)轉錄因子已知會參與在許多器官已及組織的發育中,而胎盤就是其中之一,有文獻指出DLX3會藉由與PGF啟動子結合進而調控PGF的表現量以及利用同源蛋白質區段 (Homeobox domain) 與GCM1有交互作用,因此,我們想了解DLX3會不會影響到GCM1調控PGF啟動子的能力,更進一步我們想知道DLX3是如何調控GCM1的活性。在我們的實驗結果中,藉由冷光報導基因活性檢測 (Luciferase reporter assay),我們證實文獻所說DLX3單獨表現會令PGF啟動子的活性上升是不正確的,但DLX3在擁有GCM1的環境之下會降低GCM1調控PGF的啟動子的能力。利用共同免疫沉澱法我們證實了DLX3及GCM1的確有交互作用,並且DLX3會藉由與GCM1的transactivation domain (TAD)做結合來影響GCM1的轉錄活性。更進一步,我們發現在人類絨毛膜癌BeWo細胞株中,加入毛喉素(Forskolin)的組別中,DLX3 mRNA表現量下降會讓GCM1的目標基因PGF及hCGβ mRNA的表現量上升。而後我們發現DLX3會降低cAMP/PKA 路徑中CREB-binding protein (CBP)與GCM1的交互作用及GCM1的乙醯化。綜合以上結果,我們發現DLX3會藉由與GCM1的交互作用來降低cAMP/PKA路徑中CBP與GCM1的交互作用降低GCM1的轉錄活性,進而影響到PGF啟動子的活性。 GCM1 (Glial cells missing 1) transcription factor plays an important role in trophoblast cell differentiation during placental development. GCM1 activates downstream genes to promote the differentiation of cytotrophoblasts (CTBs) into syncytiotrophoblasts (STBs) and extravillous trophoblasts (EVTs). In addition, GCM1 regulates placental hormone synthesis. The cAMP/PKA signaling pathway, which can be activated by forskolin, is known to upregulate the transcription activity of GCM1. Placental growth factor (PGF), which is a member of vascular endothelial growth factor, has been shown to be a GCM1 target gene. PGF is expressed in trophoblast cells and insufficient serum level of PGF is associated with preeclampsia, which is a pregnancy complication with clinical features of gestational hypertension and proteinuria. The transcription factor Distal-less 3 (DLX3) is an essential regulator in many tissues and organs, and in placental development. Previous studies have shown that DLX3 regulates PGF expression and interacts with GCM1. Here we investigated whether DLX3 is involved in GCM1-mediated PGF gene expression, and how DLX3 regulates GCM1 transcriptional activity. We showed that DLX3 down-regulates GCM1-mediated PGF promoter activity. Co-immunoprecipitation demonstrated that DLX3 interacts with GCM1 transactivation domain and impairs GCM1 transcriptional activity. Correspondingly, DLX3 knockdown in the BeWo choriocarcinoma cell line enhanced the stimulation of PGF and hCGβ by forskolin, which can be attributed to suppression of CBP-mediated GCM1 acetylation and activation by GCM1-DLX3 interaction. This study reveals a novel mechanism for regulation of PGF by GCM1 and DLX3 in placenta. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/70997 |
DOI: | 10.6342/NTU201801992 |
全文授權: | 有償授權 |
顯示於系所單位: | 生化科學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-107-1.pdf 目前未授權公開取用 | 1.9 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。