PGI_2-PPARδ信号传导途径与哺乳动物的胚胎着床

PGI_2-PPARδ Signal Transduction Pathway in Mammalian Embryo Implantation

前列腺素 (PGs)在胚泡着床和子宫的蜕膜化过程中起着重要的调节作用 ,前列环素 (PGI2 )是着床位点表达量最高的PGs .前列环素受体 (IP)和过氧化物酶体增殖因子活化受体 (PPARs)分别是PGI2 的细胞表面G蛋白偶联的受体和细胞核内受体 ,IP在胚泡着床位点不表达或检测不到 ,而PPARδ表达丰富 ,RXRs (PPARs的异二聚体伴侣 )及相应的PPARδ RXRα复合物、PGI2 合成酶 (COX 2 /PGIS)也在着床位点表达丰富 ,因此推测PGI2 在胚泡着床中的作用可能是通过PPARδ受体介导的 .利用PGI2 类似物 (cPGI)和PPARδ特异性类似物能够恢复COX 2基因敲除小鼠的胚泡着床和蜕膜化 .总之 ,PGI2

Prostaglandins (PGs) are important in blastocyst implantation and decidualization. The level of PGI 2 was the highest followed by PGE 2 in the site of blastocyst implantation. In addition, PGI 2 level was significantly higher at the implantation sites than inter-implantation sites. IP and PPARs are the G protein-coupled cell surface receptors that are linked to different cytoplasmic signaling pathways and the nuclear hormone receptors, respectively. IP is not expressed or undetectable at implantation sites, but PPARδ expression is very abundant. RXRs (the partner receptor for PPARs), PPARδ-RXRα heterodimer and PGI 2 synthase (COX-2/PGIS) are also abundant at implantation sites. Both PGI 2 agonist (cPGI) and PPARδ specific agonist can restore blastocyst implantation and decidualization in COX-2 -/- mice. These data suggested that PGI 2 may play important roles in blastocyst implantation and decidualization by PPARδ activation.