EPAC2-mediated calreticulin regulates LIF and COX2 expression in human endometrial glandular cells.
The proper production of the implantation-related factors, leukemia inhibitory factor (LIF), cyclooxygenase 2 (COX2, PTGS2), and prostaglandin E2 (PGE2) in the uterine glands is essential for embryo implantation and the establishment of endometrial receptivity. It has been shown that cAMP-mediated protein kinase A (PKA) signaling regulates the production of these factors. We have previously reported that exchange protein directly activated by cAMP 2 (EPAC2, RAPGEF4), another cAMP mediator, is involved in the differentiation of endometrial stromal cells through the regulation of the expression of calreticulin (CALR). To address whether EPAC2-CALR signaling is involved in the expression of implantation-related factors, we examined the effect of EPAC2 and CALR knockdown on their expression in cultured human endometrial glandular epithelial EM1 cells, treated with forskolin, an adenylyl cyclase activator, an EPAC-selective cAMP analog (8-(4-chlorophenylthio)-2'-O-methyl cAMP (CPT)), or a PKA-selective cAMP analog (N(6)-phenyl-cAMP (Phe)). In addition, the status of cell senescence was examined. EPAC2 knockdown suppressed the expression of CALR protein and mRNA in EM1 cells. Forskolin- or Phe-, but not CPT-, induced expression of LIF or PTGS2 and secretion of PGE2 was inhibited in EPAC2- or CALR-silenced EM1 cells. In addition, knockdown of EPAC2 or CALR increased senescence-associated beta galactosidase activity and expression of p21 but decreased expression of p53. These findings indicate that expression of CALR regulated by EPAC2 in endometrial glandular epithelial cells is critical for the expression of LIF and PTGS2-mediated production of PGE2 through cAMP signaling. Furthermore, EPAC2 and CALR could play a role in the maintenance of gland function.
Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Kazuya
K
Kusama
Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Mikihiro
M
Yoshie
Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan hiro@toyaku.ac.jp.
Kazuhiro
K
Tamura
Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Kazuhiko
K
Imakawa
Department of Endocrine and Neural PharmacologyTokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, JapanLaboratory of Theriogenology and Animal BreedingGraduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Eiichi
E
Tachikawa
D064032:Calbindin 2 / Q000378:metabolism*; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D004717:Endometrium / Q000166:cytology*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D020662:Guanine Nucleotide Exchange Factors / Q000502:physiology*; D006801:Humans; D053605:Leukemia Inhibitory Factor / Q000235:genetics / Q000378:metabolism*
C576764:CALB2 protein, human; D064032:Calbindin 2; D020662:Guanine Nucleotide Exchange Factors; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; C442864:RAPGEF4 protein, human; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human
calreticulin (CALR); cyclooxygenase 2 (COX2, PTGS2); endometrial glandular epithelial cell; exchange protein directly activated by cAMP (EPAC); leukemia inhibitory factor (LIF); prostaglandin E2 (PGE2)