title: Complex regulation of Calbindin-D(9k) in the mouse placenta and extra-embryonic membrane during mid- and late pregnancy.
abstract: Calbindin-D(9k) (CaBP-9k) is a cytosolic calcium-binding protein mainly expressed in the duodenum, uterus and placenta, however, the role of CaBP-9k in the regulation of fetal growth remains to be elucidated. The present study was performed to investigate the expression pattern and regulation of CaBP-9k by antagonists of steroid hormones related with steroid hormone receptors during mid- and late pregnancy in mouse placenta and extra-embryonic membrane. The expression level of CaBP-9k increased in the placenta, while it decreased in the extra-embryonic membrane during pregnancy. The mRNA expression levels of estrogen receptor alpha (ERalpha) and progesterone receptor (PR) appeared to increase in both placenta and extra-embryonic membrane during pregnancy, suggesting that the ER and PR mRNA and protein expressions of placental CaBP-9k are positively correlated, but expressions of extra-embryonic membrane CaBP-9k are reversely correlated with ERalpha and PR mRNA levels. In addition, the present study indicates that the expressions of CaBP-9k mRNA and protein are differentially up- or down-regulated by antagonists of estrogen (E2) and progesterone (P4) in mouse placenta and extra-embryonic membranes, which suggests that E2 and P4 may be dominant factors in the regulation of the CaBP-9k. In particular, RU486, an antagonist of P4, down-regulated the mRNA and protein levels of placental CaBP-9k, whereas it up-regulated the protein level of extra-embryonic membrane CaBP-9k. In conclusion, we demonstrated that the CaBP-9k is distinctly regulated in the mouse placenta and extra-embryonic membrane, probably via sex steroid hormones (E2 and P4) and their receptors through a complex pathway. Extended studies are needed to verify relevant factors to regulate CaBP-9k gene and to provide further insight into roles of CaBP-9k gene in these tissues for the control of reproductive functions.
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, 361-763 Republic of Korea.
authors.forename: Beum-Soo
authors.initials: BS
authors.lastname: An
authors.forename: Kyung-Chul
authors.initials: KC
authors.lastname: Choi
authors.forename: Geun-Shik
authors.initials: GS
authors.lastname: Lee
authors.forename: Peter C K
authors.initials: PC
authors.lastname: Leung
authors.forename: Eui-Bae
authors.initials: EB
authors.lastname: Jeung
mesh_terms: D000818:Animals; D064026:Calbindins; D004958:Estradiol / Q000502:physiology; D047628:Estrogen Receptor alpha; D005321:Extraembryonic Membranes / Q000166:cytology / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008813:Mice, Inbred ICR; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D011960:Receptors, Estrogen / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D064030:S100 Calcium Binding Protein G / Q000032:analysis / Q000096:biosynthesis*; D013997:Time Factors
chemical_list: D064026:Calbindins; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D064030:S100 Calcium Binding Protein G; D011374:Progesterone; D004958:Estradiol