MicroRNA-212 Regulates the Expression of Olfactomedin 1 and C-Terminal Binding Protein 1 in Human Endometrial Epithelial Cells to Enhance Spheroid Attachment In Vitro.

Abstract

Successful embryo implantation requires a synchronized dialogue between a competent blastocyst and the receptive endometrium, which occurs in a limited time period known as the "window of implantation." Recent studies suggested that down-regulation of olfactomedin 1 (OLFM1) in the endometrium and fallopian tube is associated with receptive endometrium and tubal ectopic pregnancy in humans. Interestingly, the human chorionic gonadotropin (hCG) induces miR-212 expression, which modulates OLFM1 and C-terminal binding protein 1 (CTBP1) expressions in mouse granulosa cells. Therefore, we hypothesized that embryo-derived hCG would increase miR-212 expression and down-regulate OLFM1 and CTBP1 expressions to favor embryo attachment onto the female reproductive tract. We found that hCG stimulated the expression of miR-212 and down-regulated OLFM1 but not CTBP1 mRNA in both human endometrial (Ishikawa) and fallopian (OE-E6/E7) epithelial cells. However, hCG suppressed the expression of OLFM1 and CTBP1 proteins in both cell lines. The 3'UTR of both OLFM1 and CTBP1 contained binding sites for miR-212. The miR-212 precursor suppressed luciferase expression, whereas the miR-212 inhibitor stimulated luciferase expression of the wild-type (WT)-OLFM1 and WT-CTBP1 reporter constructs. Furthermore, hCG (25 IU/ml) treatments stimulated trophoblastic (Jeg-3) spheroid (blastocyst surrogate) attachment onto Ishikawa and OE-E6/E7 cells. Transfection of miR-212 precursor increased Jeg-3 spheroid attachment onto Ishikawa cells and decreased OLFM1 and CTBP1 protein expressions, whereas the opposite occurred with miR-212 inhibitor. Taken together, hCG stimulated miR-212, which in turn down-regulated OLFM1 and CTBP1 expression in fallopian and endometrial epithelial cells to favor spheroid attachment.

• Authors: Kottawattage S A Kottawatta, Kam-Hei So, Suranga P Kodithuwakku, Ernest H Y Ng, William S B Yeung, Kai-Fai Lee
• Journal: Biology of reproduction (Biol Reprod) Vol. 93 Issue 5 Pg. 109 (Nov 2015) ISSN: 1529-7268 [Electronic] United States
• PMID: 26377223 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 by the Society for the Study of Reproduction, Inc.

Chemical References

• Chorionic Gonadotropin
• DNA-Binding Proteins
• Extracellular Matrix Proteins
• Glycoproteins
• MIRN212 microRNA, human
• MicroRNAs
• olfactomedin
• Alcohol Oxidoreductases
• C-terminal binding protein

Topics

• Alcohol Oxidoreductases (metabolism)
• Chorionic Gonadotropin
• DNA-Binding Proteins (metabolism)
• Embryo Implantation
• Endometrium (metabolism)
• Epithelial Cells (metabolism)
• Extracellular Matrix Proteins (metabolism)
• Fallopian Tubes (metabolism)
• Female
• Glycoproteins (metabolism)
• HeLa Cells
• Humans
• MicroRNAs (metabolism)
• Spheroids, Cellular