探討synapse defective 1 (SYDE1)功能缺失及胎兒發育遲緩的關聯性–SYDE1調控胎盤細胞移行與入侵

Association of dysfunctional synapse defective 1 (SYDE1) with restricted fetal growth – SYDE1 regulates placental cell migration and invasion

羅曉帆(Hsiao-Fan Lo)

指導教授 ： 陳宏文

國立臺灣大學/生命科學院/生化科學研究所/博士(2016年)

https://doi.org/10.6342/NTU201602634

摘要

GCM1 (glial cells missing 1)調控胎盤滋養層細胞 (trophoblast cell)的分化與功能，是維持胎盤發育的重要轉錄因子之一。GCM1表現量下降與子癲前症的發生有所相關，顯示GCM1所調控的標的基因表現異常，可能導致妊娠併發症發病原因之一。在這篇研究當中，我們鑑定了一個新的GCM1標的基因-SYDE1，此基因包含了RhoGAP區域並且高度表現在人類胎盤組織，且我們證明了SYDE1會促進細胞骨架重構，細胞移行與入侵的能力。更重要的是，Syde1的基因剔除小鼠會伴隨著胎盤-卵黃囊屏障(placental-yolk sac barrier)，母體與滋養層細胞的交界面(maternal-trophoblast interface)，以及胎盤血管形成的構造不正常導致於胎兒發育遲緩與胎盤過小的現象。此外，藉由基因晶片分析Syde1基因剔除鼠的胎盤，發現腎素-血管收縮素系統(renin-angiotensin system)表現有所改變，而在懷孕過程中，在缺乏Syde1的胎盤中Syde1的同源基因-Syde2表現量有所上升，所以推測Syde2可能會補償Syde1的功能缺失。在透過shRNA抑制SYDE1表現的人類絨毛膜癌細胞株(JAR trophoblast cell)中同時表現SYDE2，觀察到正常功能的SYDE2會恢復細胞移行與入侵能力，而GAP區域功能缺失的SYDE2則無法彌補。更進一步在臨床研究上觀察發現，與相當妊娠週齡的控制組相比，SYDE1在早產與足月出生且胎兒發育過小的胎盤中表現量較低。綜合以上結果，我們證實了在胎盤發育過程中，GCM1透過調控SYDE1的表現而影響滋養層細胞的移行與入侵能力，而SYDE1表現過低與胎兒發育遲緩有所相關性。

關鍵字

SYDE1 ； GCM1 ； 細胞移行/入侵 ； 胎兒發育遲緩 ； 胎盤

並列摘要

The GCM1 transcription factor regulates trophoblast differentiation and function during placentation. Decreased GCM1 expression is associated with preeclampsia, suggesting that abnormal expression of GCM1 target genes may contribute to the pathogenesis of pregnancy complications. Here we identified a novel GCM1 target gene SYDE1, which encodes a RhoGAP highly expressed in human placenta, and demonstrated that SYDE1 promotes cytoskeletal remodeling and cell migration and invasion. Importantly, genetic ablation of murine Syde1 results in small fetuses and placentas with aberrant phenotypes in the placental-yolk sac barrier, maternal-trophoblast interface, and placental vasculogenesis. Correspondingly, microarray analysis revealed altered expression of the renin-angiotensin system in Syde1-knockout placenta. As pregnancy proceeds, growth restriction of the Syde1-/- fetuses and placentas continues with elevated expression of the Syde1 homologue Syde2 in placenta. Syde2 may compensate for the loss of Syde1 function because SYDE2, but not the GAP-dead SYDE2 mutant, reverses migration and invasion activities of SYDE1-knockdown JAR trophoblast cells. Clinically, we further detected decreased SYDE1 expression in preterm and term IUGR placentas compared with gestational age-matched controls. Our study reveals a novel mechanism for GCM1 and SYDE1 in regulation of trophoblast cell migration and invasion during placental development and that decreased SYDE1 expression is associated with IUGR.

並列關鍵字

SYDE1 ； GCM1 ； cell migration/invasion ； IUGR ； placenta

參考文獻

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