FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
PloS one2019; 14(3); e0213322; doi: 10.1371/journal.pone.0213322

The role of embryo contact and focal adhesions during maternal recognition of pregnancy.

Abstract: Maternal recognition of pregnancy (MRP) in the mare is an unknown process. In a non-pregnant mare on day 14 post-ovulation (PO), prostaglandin F2α (PGF) is secreted by the endometrium causing regression of the corpus luteum. Prior to day 14, MRP must occur in order to attenuate secretion of PGF. The embryo is mobile throughout the uterus due to uterine contractions from day of entry to day 14. It is unknown what signaling is occurring. Literature stated that infusing oil or placing a glass marble into the equine uterus prolongs luteal lifespan and that in non-pregnant mares, serum exosomes contain miRNA that are targeting the focal adhesion (FA) pathway. The hypothesis of this study is embryo contact with endometrium causes a change in abundance of focal adhesion molecules (FA) in the endometrium leading to decrease in PGF secretion. Mares (n = 3/day) were utilized in a cross-over design with each mare serving as a pregnant and non-pregnant (non-mated) control on days 9 and 11 PO. Mares were randomly assigned to collection day and endometrial samples and embryos were collected on the specified day. Biopsy samples were divided into five pieces, four for culture for 24 hours and one immediately snap frozen. Endometrial biopsies for culture were placed in an incubator with one of four treatments: [1] an embryo in contact on the luminal side of the endometrium, [2] beads in contact on the luminal side of the endometrium, [3] peanut oil in contact on the luminal side of the endometrium or [4] the endometrium by itself. Biopsies and culture medium were frozen for further analysis. RNA and protein were isolated from biopsies for PCR and Western blot analysis for FA. PGF assays were performed on culture medium to determine concentration of PGF. Statistics were performed using SAS (P ≤ 0.05 indicated significance). The presence of beads on day 9 impacted samples from pregnant mares more than non-pregnant mares and had very little impact on day 11. Presence of oil decreased FA in samples from pregnant mares on day 9. On day 11, oil decreased FA abundance in samples from non-pregnant mares. Embryo contact caused multiple changes in RNA and protein abundance in endometrium from both pregnant and non-pregnant mares. The PGF secretion after 24 hours with each treatment was also determined. On day 9, there was no change in PGF secretion compared to any treatments. On day 11, presence of peanut oil increased PGF secretion in samples from non-pregnant mares. In samples from non-pregnant mares, presence of an embryo decreased PGF secretion compared to control samples from non-pregnant mares. Results revealed that while beads and peanut oil may impact abundance of FA RNA and protein in endometrial samples, it does not appear to impact PGF secretion. Conversely, embryo contact for 24 hours with endometrium from a non-pregnant mare causes a decrease in PGF secretion. These results suggest that it is not just contact of any substance/object causing attenuation of PGF secretion, but the embryo itself is necessary to decrease PGF secretion.
Get Full Text
Publication Date: 2019-03-05 PubMed ID: 30835748PubMed Central: PMC6400379DOI: 10.1371/journal.pone.0213322Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research article investigates the process of Maternal Recognition of Pregnancy (MRP) in mares, and posits that it is the contact of the embryo with the endometrium that decreases prostaglandin F2α (PGF) secretion, leading to a recognition of pregnancy.

Research Context and Hypothesis

  • The article probes the mystery of the process by which mares’ bodies recognize pregnancy. The authors test the deduction that the contact of the embryo with the endometrium causes a change in the abundance of focal adhesion molecules (FA) within the endometrium, leading to a decrease in the secretion of prostaglandin F2α (PGF).

Research Methodology

  • A group of mares were used under a cross-over design experiment, serving as both pregnant and non-pregnant (non-mated) controls. The team collected endometrial samples and embryos on different days post-ovulation (PO).
  • Endometrial biopsies were put into an incubator with either an embryo, beads, peanut oil or by itself making contact with the endometrium, after dividing them into five sections.
  • Protein and RNA were isolated from these samples for tests and analyses with Western blot analysis and PCR for FA. Further, they used PGF assays on the culture medium to determine the concentration of PGF. 

Research Findings and Conclusion

  • The presence of beads or oil on day 9 showed an effect on samples from pregnant mares, but not much effect on day 11. The presence of an embryo, however, caused multiple changes in RNA and protein abundance in the endometrium from both pregnant and non-pregnant mares.
  • There wasn’t any major change in PGF secretion on day 9 in comparison to any treatments. However, on day 11, the presence of peanut oil increased PGF secretion in samples from non-pregnant mares. Fascinatingly, the presence of an embryo decreased PGF secretion in non-pregnant mares.
  • It was found that beads and peanut oil may impact abundance of FA RNA and protein in the endometrial samples, but this does not seem to change PGF secretion. Conversely, the contact of an embryo with the endometrium from a non-pregnant mare results in a decrease in PGF secretion, helping to confirm the embryo’s role in attenuating PGF secretion.

Implications of the Research

  • The study suggests that contact of any substance or object with the endometrium does not cause a reduction in PGF secretion. Rather, it is the embryo itself that is necessary for this effect, shedding new light on the institution of MRP in mares, and opening avenues for further studies in this area.

Cite This Article

APA
Klohonatz KM, Nulton LC, Hess AM, Bouma GJ, Bruemmer JE. (2019). The role of embryo contact and focal adhesions during maternal recognition of pregnancy. PLoS One, 14(3), e0213322. https://doi.org/10.1371/journal.pone.0213322

Publication

PloS one
ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 14
Issue: 3
Pages: e0213322
PII: e0213322

Researcher Affiliations

Klohonatz, K M
  • Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
Nulton, L C
  • Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
Hess, A M
  • Department of Statistics and Bioinformatics, Colorado State University, Fort Collins, Colorado, United States of America.
Bouma, G J
  • Department of Biomedical Sciences, Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, Colorado, United States of America.
Bruemmer, J E
  • Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States of America.

MeSH Terms

  • Animals
  • Cells, Cultured
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / physiology
  • Endometrium / metabolism
  • Female
  • Focal Adhesions / physiology
  • Horses
  • Pregnancy
  • Pregnancy, Animal
  • Prostaglandins F / metabolism

Conflict of Interest Statement

The authors have declared that no competing interests exist.

References

This article includes 35 references
  1. Allen WR, Stewart F. Equine placentation.. Reprod Fertil Dev 2001;13(7-8):623-34.
    pubmed: 11999314doi: 10.1071/rd01063google scholar: lookup
  2. McCracken JA, Custer EE, Lamsa JC. Luteolysis: a neuroendocrine-mediated event.. Physiol Rev 1999 Apr;79(2):263-323.
    doi: 10.1152/physrev.1999.79.2.263pubmed: 10221982google scholar: lookup
  3. Betteridge KJ, Eaglesome MD, Mitchell D, Flood PF, Beriault R. Development of horse embryos up to twenty two days after ovulation: observations on fresh specimens.. J Anat 1982 Aug;135(Pt 1):191-209.
    pmc: PMC1168142pubmed: 7130052
  4. Ginther OJ. Mobility of the early equine conceptus.. Theriogenology 1983 Apr;19(4):603-11.
    pubmed: 16725808doi: 10.1016/0093-691x(83)90180-2google scholar: lookup
  5. Ginther OJ. Internal regulation of physiological processes through local venoarterial pathways: a review.. J Anim Sci 1974 Sep;39(3):550-64.
    pubmed: 4213194doi: 10.2527/jas1974.393550xgoogle scholar: lookup
  6. Leith GS, Ginther OJ. Characterization of intrauterine mobility of the early equine conceptus.. Theriogenology 1984 Oct;22(4):401-8.
    pubmed: 16725972doi: 10.1016/0093-691x(84)90460-6google scholar: lookup
  7. Stout TA, Allen WR. Role of prostaglandins in intrauterine migration of the equine conceptus.. Reproduction 2001 May;121(5):771-5.
    pubmed: 11427165
  8. McCracken JA, Glew ME, Scaramuzzi RJ. Corpus luteum regression induced by prostagland in F2-alpha.. J Clin Endocrinol Metab 1970 Apr;30(4):544-6.
    doi: 10.1210/jcem-30-4-544pubmed: 5435294google scholar: lookup
  9. Douglas RH, Ginther OJ. Effect of prostaglandin F2alpha on length of diestrus in mares.. Prostaglandins 1972 Oct;2(4):265-8.
    pubmed: 4677341doi: 10.1016/s0090-6980(72)80014-5google scholar: lookup
  10. Roberts RM, Xie S, Mathialagan N. Maternal recognition of pregnancy.. Biol Reprod 1996 Feb;54(2):294-302.
    pubmed: 8788179doi: 10.1095/biolreprod54.2.294google scholar: lookup
  11. Baker CB, Adams MH, McDowell KJ. Lack of expression of alpha or omega interferons by the horse conceptus.. J Reprod Fertil Suppl 1991;44:439-43.
    pubmed: 1724463
  12. Vanderwall DK, Woods GL, Weber JA, Lichtenwalner AB. Corpus luteal function in nonpregnant mares following intrauterine administration of prostaglandin E(2) or estradiol-17beta.. Theriogenology 1994;42(7):1069-83.
    pubmed: 16727611doi: 10.1016/0093-691x(94)90855-9google scholar: lookup
  13. Bazer FW, Spencer TE, Ott TL. Interferon tau: a novel pregnancy recognition signal.. Am J Reprod Immunol 1997 Jun;37(6):412-20.
    pubmed: 9228295doi: 10.1111/j.1600-0897.1997.tb00253.xgoogle scholar: lookup
  14. Ziecik AJ. Old, new and the newest concepts of inhibition of luteolysis during early pregnancy in pig.. Domest Anim Endocrinol 2002 Jul;23(1-2):265-75.
    pubmed: 12142243doi: 10.1016/s0739-7240(02)00162-5google scholar: lookup
  15. Wilsher S, Allen WR. Intrauterine administration of plant oils inhibits luteolysis in the mare.. Equine Vet J 2011 Jan;43(1):99-105.
    doi: 10.1111/j.2042-3306.2010.00131.xpubmed: 21143640google scholar: lookup
  16. Rivera Del Alamo MM, Reilas T, Kindahl H, Katila T. Mechanisms behind intrauterine device-induced luteal persistence in mares.. Anim Reprod Sci 2008 Aug;107(1-2):94-106.
    doi: 10.1016/j.anireprosci.2007.06.010pubmed: 17643876google scholar: lookup
  17. McDowell KJ, Sharp DC, Grubaugh W, Thatcher WW, Wilcox CJ. Restricted conceptus mobility results in failure of pregnancy maintenance in mares.. Biol Reprod 1988 Sep;39(2):340-8.
    pubmed: 3179385doi: 10.1095/biolreprod39.2.340google scholar: lookup
  18. Mathivanan S, Ji H, Simpson RJ. Exosomes: extracellular organelles important in intercellular communication.. J Proteomics 2010 Sep 10;73(10):1907-20.
    doi: 10.1016/j.jprot.2010.06.006pubmed: 20601276google scholar: lookup
  19. Valadi H, Ekström K, Bossios A, Sjöstrand M, Lee JJ, Lötvall JO. Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells.. Nat Cell Biol 2007 Jun;9(6):654-9.
    doi: 10.1038/ncb1596pubmed: 17486113google scholar: lookup
  20. Klohonatz KM, Cameron AD, Hergenreder JR, da Silveira JC, Belk AD, Veeramachaneni DN, Bouma GJ, Bruemmer JE. Circulating miRNAs as Potential Alternative Cell Signaling Associated with Maternal Recognition of Pregnancy in the Mare.. Biol Reprod 2016 Dec;95(6):124.
    doi: 10.1095/biolreprod.116.142935pubmed: 27760749google scholar: lookup
  21. Burghardt RC, Burghardt JR, Taylor JD 2nd, Reeder AT, Nguen BT, Spencer TE, Bayless KJ, Johnson GA. Enhanced focal adhesion assembly reflects increased mechanosensation and mechanotransduction at maternal-conceptus interface and uterine wall during ovine pregnancy.. Reproduction 2009 Mar;137(3):567-82.
    doi: 10.1530/REP-08-0304pubmed: 19060096google scholar: lookup
  22. Vogel V, Sheetz M. Local force and geometry sensing regulate cell functions.. Nat Rev Mol Cell Biol 2006 Apr;7(4):265-75.
    doi: 10.1038/nrm1890pubmed: 16607289google scholar: lookup
  23. Kenney RM. Cyclic and pathologic changes of the mare endometrium as detected by biopsy, with a note on early embryonic death.. J Am Vet Med Assoc 1978 Feb 1;172(3):241-62.
    pubmed: 621166
  24. Watson ED, Sertich PL. Prostaglandin production by horse embryos and the effect of co-culture of embryos with endometrium from pregnant mares.. J Reprod Fertil 1989 Sep;87(1):331-6.
    pubmed: 2621704doi: 10.1530/jrf.0.0870331google scholar: lookup
  25. Nie GJ, Johnson KE, Braden TD, Wenzel JG. Use of an intra-uterine glass ball protocol to extend luteal function in mares.. Journal of equine veterinary science 2003;23(6):266–73.
  26. Katz BZ, Zamir E, Bershadsky A, Kam Z, Yamada KM, Geiger B. Physical state of the extracellular matrix regulates the structure and molecular composition of cell-matrix adhesions.. Mol Biol Cell 2000 Mar;11(3):1047-60.
    doi: 10.1091/mbc.11.3.1047pmc: PMC14830pubmed: 10712519google scholar: lookup
  27. Galbraith CG, Yamada KM, Sheetz MP. The relationship between force and focal complex development.. J Cell Biol 2002 Nov 25;159(4):695-705.
    doi: 10.1083/jcb.200204153pmc: PMC2173098pubmed: 12446745google scholar: lookup
  28. Bershadsky A, Kozlov M, Geiger B. Adhesion-mediated mechanosensitivity: a time to experiment, and a time to theorize.. Curr Opin Cell Biol 2006 Oct;18(5):472-81.
    doi: 10.1016/j.ceb.2006.08.012pubmed: 16930976google scholar: lookup
  29. Brunson A, Ohashi T, Jesmin S, Mowa C. Caveolin-1, a Mechano-Mediator, is Expressed in the Epithelial and Stromal Cells of Mice Cervix and Increases During Pregnancy.. The FASEB Journal 2015;29(1_supplement):574.26.
  30. Madawala RJ, Day ML, Murphy CR. Caveolin and Focal Adhesion Proteins Talin and Paxillin During Early Pregnancy in the Rat and in Human Ishikawa Cells.. .
  31. Weeds AG, Gooch J, Hawkins M, Pope B, Way M. Role of actin-binding proteins in cytoskeletal dynamics.. Biochem Soc Trans 1991 Nov;19(4):1016-20.
    pubmed: 1665426doi: 10.1042/bst0191016google scholar: lookup
  32. Png FY, Murphy CR. Cytoskeletal proteins in uterine epithelial cells only partially return to the pre-receptive state after the period of receptivity.. Acta Histochem 2002;104(3):235-44.
    doi: 10.1078/0065-1281-00652pubmed: 12389737google scholar: lookup
  33. Moreno-Bueno G, Rodríguez-Perales S, Sánchez-Estévez C, Hardisson D, Sarrió D, Prat J, Cigudosa JC, Matias-Guiu X, Palacios J. Cyclin D1 gene (CCND1) mutations in endometrial cancer.. Oncogene 2003 Sep 4;22(38):6115-8.
    doi: 10.1038/sj.onc.1206868pubmed: 12955092google scholar: lookup
  34. Steeg PS, Zhou Q. Cyclins and breast cancer.. Breast Cancer Res Treat 1998;52(1-3):17-28.
    pubmed: 10066069doi: 10.1023/a:1006102916060google scholar: lookup
  35. Cao QJ, Einstein MH, Anderson PS, Runowicz CD, Balan R, Jones JG. Expression of COX-2, Ki-67, cyclin D1, and P21 in endometrial endometrioid carcinomas.. Int J Gynecol Pathol 2002 Apr;21(2):147-54.
    pubmed: 11917224doi: 10.1097/00004347-200204000-00007google scholar: lookup

Citations

This article has been cited 12 times.
  1. Diniz WJS, Banerjee P, Rodning SP, Dyce PW. Machine Learning-Based Co-Expression Network Analysis Unravels Potential Fertility-Related Genes in Beef Cows. Animals (Basel) 2022 Oct 9;12(19).
    doi: 10.3390/ani12192715pubmed: 36230456google scholar: lookup
  2. Godakumara K, Dissanayake K, Hasan MM, Kodithuwakku SP, Fazeli A. Role of extracellular vesicles in intercellular communication during reproduction. Reprod Domest Anim 2022 Oct;57 Suppl 5(Suppl 5):14-21.
    doi: 10.1111/rda.14205pubmed: 35837748google scholar: lookup
  3. Mei X, Xu L, Ren Y, Yu M, Kuang L, Li C, Zhang Y, Lu C, Wang Z, Guo Z, Xie X, Huang D, Zhang M. Transcriptome Comparison of Chorion-Attached and Non-chorion-attached Endometrium in Mid-gestation of Rabbit. Front Vet Sci 2022;9:838802.
    doi: 10.3389/fvets.2022.838802pubmed: 35372533google scholar: lookup
  4. Rivera Del Alamo MM, Reilas T, Lukasik K, Galvão AM, Yeste M, Katila T. Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation. Animals (Basel) 2021 Dec 8;11(12).
    doi: 10.3390/ani11123493pubmed: 34944269google scholar: lookup
  5. Swegen A. Maternal recognition of pregnancy in the mare: does it exist and why do we care?. Reproduction 2021 May 5;161(6):R139-R155.
    doi: 10.1530/REP-20-0437pubmed: 33957605google scholar: lookup
  6. Klohonatz KM, Coleman SJ, Cameron AD, Hess AM, Reed KJ, Canovas A, Medrano JF, Islas-Trejo AD, Kalbfleisch T, Bouma GJ, Bruemmer JE. Non-Coding RNA Sequencing of Equine Endometrium During Maternal Recognition of Pregnancy. Genes (Basel) 2019 Oct 18;10(10).
    doi: 10.3390/genes10100821pubmed: 31635328google scholar: lookup
  7. Klohonatz KM, Coleman SJ, Islas-Trejo AD, Medrano JF, Hess AM, Kalbfleisch T, Thomas MG, Bouma GJ, Bruemmer JE. Coding RNA Sequencing of Equine Endometrium during Maternal Recognition of Pregnancy. Genes (Basel) 2019 Sep 25;10(10).
    doi: 10.3390/genes10100749pubmed: 31557877google scholar: lookup
  8. Qu Z, Luo Z, Wang Y, Zhu B, Lu X, Xing C, Cao X, You D. ITGB3 and associated molecules as critical biomarkers in Cesarean Scar Pregnancy. BMC Pregnancy Childbirth 2025 May 29;25(1):629.
    doi: 10.1186/s12884-025-07752-4pubmed: 40442657google scholar: lookup
  9. Brighton PJ, Walker AR, Mann O, Kong CS, Lucas ES, Vrljicak P, Brosens JJ, Hanyaloglu AC. Spatial-temporal regulation of the prostanoid receptor EP2 co-ordinates PGE2-mediated cAMP signaling in decidualizing human endometrium. iScience 2024 Nov 15;27(11):111170.
    doi: 10.1016/j.isci.2024.111170pubmed: 39555416google scholar: lookup
  10. Almeida GHDR, da Silva RS, Gibin MS, Gonzaga VHS, Dos Santos H, Igleisa RP, Fernandes LA, Fernandes IC, Nesiyama TNG, Sato F, Baesso ML, Hernandes L, Rinaldi JC, Meirelles FV, Astolfi-Ferreira CS, Ferreira AJP, Carreira ACO. Region-Specific Decellularization of Porcine Uterine Tube Extracellular Matrix: A New Approach for Reproductive Tissue-Engineering Applications. Biomimetics (Basel) 2024 Jun 24;9(7).
    doi: 10.3390/biomimetics9070382pubmed: 39056823google scholar: lookup
  11. Fazeli A, Godakumara K. The evolving roles of extracellular vesicles in embryo-maternal communication. Commun Biol 2024 Jun 21;7(1):754.
    doi: 10.1038/s42003-024-06442-9pubmed: 38906986google scholar: lookup
  12. Piotrowska-Tomala KK, Jonczyk AW, Szóstek-Mioduchowska A, Hojo T, Żebrowska E, Katila T, Ferreira-Dias G, Skarzynski DJ. Intrauterine devices influence prostaglandin secretion by equine uterus: in vitro and in vivo studies. BMC Vet Res 2024 Feb 3;20(1):46.
    doi: 10.1186/s12917-024-03889-0pubmed: 38310284google scholar: lookup
Subscribe to our newsletter
Join 99,727 horse owners like you who receive our email updates on horse health and nutrition.