HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 77/1/172    most recent biolreprod.106.056309v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ka, H. Articles by Bazer, F. W. Search for Related Content PubMed PubMed Citation Articles by Ka, H. Articles by Bazer, F. W. Agricola Articles by Ka, H. Articles by Bazer, F. W.

Regulation of Expression of Fibroblast Growth Factor 7 in the Pig Uterus by Progesterone and Estradiol¹

Center for Animal Biotechnology and Genomics,⁴ Departments of Animal Science,⁵ and Veterinary Integrative Biosciences,⁶ Texas A&M University, College Station, Texas 77843 Department of Biological Resources and Technology,⁷ Yonsei University, Wonju 220-710, South Korea

ABSTRACT

Fibroblast growth factor 7 (FGF7) stimulates cell proliferation, differentiation, migration and angiogenesis. The consensus is that FGF7, expressed by mesenchymal cells, binds FGF receptor 2IIIb (FGFR2) on epithelia, thereby mediating epithelial-mesenchymal interactions. The pig uterus is unique in that FGF7 is expressed by the luminal epithelium (LE) and FGFR2 is expressed by the LE, glandular epithelium (GE), and trophectoderm to effect proliferation and differentiated cell functions during conceptus development and implantation. FGF7 expression by the uterine LE of pigs increases between Days 9 and 12 of the estrus cycle and pregnancy, as circulating concentrations of progesterone increase, progesterone receptors (PGR) in the uterine epithelia decrease, and the conceptuses secrete estradiol-17beta (E₂), for pregnancy recognition. Furthermore, E₂ increases the expression of FGF7 in pig uterine explants. The present study investigates the relationships between progesterone, E₂, and their receptors and the expression of FGF7 in the pig uterus in vivo. Pigs were ovariectomized on Day 4 of the estrus cycle and injected i.m. daily from Day 4 to Day 12 with either corn oil (CO), progesterone (P4), P4 and ZK317,316 (PZK), E₂, P4 and E₂ (PE), or P4 and ZK and E₂ (PZKE). All gilts (n = 5/treatment) were hysterectomized on Day 12. The results suggest that: 1) P4 is permissive to FGF7 expression by down-regulating PGR in LE; 2) P4 stimulates PGR-positive uterine stromal cells to release an unidentified progestamedin that induces FGF7 expression by LE; 3) E₂ and P4 can induce FGF7 when PGR are rendered nonfunctional by ZK; and 4) E₂ from conceptuses interacts via estrogen receptor alpha, but not estrogen receptor beta in LE to induce maximal expression of FGF7 in LE on Day 12 of pregnancy in pigs.

endometrium, estradiol receptor, progesterone receptor

³These authors contributed equally to this work.

¹Supported by USDA-NRICGP 2000–02290 (F.W.B. and L.A.J.) and NIH P30 ES09106 (G.A.J., R.C.B., T.E.S., F.W.B.).

Correspondence: ²Fuller W. Bazer, Department of Animal Science and Center for Animal Biotechnology and Genomics, 442D Kleberg Center, Texas A&M University, College Station, TX 77843-2471. FAX: 979 845 9938; e-mail: fbazer{at}cvm.tamu.edu

This article has been cited by other articles:

				M. M. Joyce, R. C. Burghardt, R. D. Geisert, J. R. Burghardt, R. N. Hooper, J. W. Ross, M. D. Ashworth, and G. A. Johnson Pig Conceptuses Secrete Estrogen and Interferons to Differentially Regulate Uterine STAT1 in a Temporal and Cell Type-Specific Manner Endocrinology, September 1, 2007; 148(9): 4420 - 4431. [Abstract] [Full Text] [PDF]