Steroid synthesis and metabolism in the equine placenta during placentitis.
Abstract: Equine placentitis is associated with alterations in maternal peripheral steroid concentrations, which could negatively affect pregnancy outcome. This study aimed to elucidate the molecular mechanisms related to steroidogenesis and steroid-receptor signaling in the equine placenta during acute placentitis. Chorioallantois (CA) and endometrial (EN) samples were collected from mares with experimentally induced placentitis (n = 4) and un-inoculated gestationally age-matched mares (control group; n = 4). The mRNA expression of genes coding for steroidogenic enzymes (3βHSD, CYP11A1, CYP17A1, CYP19A1, SRD5A1, and AKR1C23) was evaluated using qRT-PCR. The concentration of these enzyme-dependent steroids (P5, P4, 5αDHP, 3αDHP, 20αDHP, 3β-20αDHP, 17OH-P, DHEA, A4, and estrone) was assessed using liquid chromatography-tandem mass spectrometry in both maternal circulation and placental tissue. Both SRD5A1 and AKR1C23, which encode for the key progesterone metabolizing enzymes, were downregulated (P < 0.05) in CA from the placentitis group compared to controls, and this downregulation was associated with a decline in tissue concentrations of 5αDHP (P < 0.05), 3αDHP (P < 0.05), and 3β-20αDHP (P = 0.052). In the EN, AKR1C23 was also downregulated in the placentitis group compared to controls, and this downregulation was associated with a decline in EN concentrations of 3αDHP (P < 0.01) and 20αDHP (P < 0.05). Moreover, CA expression of CYP19A1 tended to be lower in the placentitis group, and this reduction was associated with lower (P = 0.057) concentrations of estrone in CA. Moreover, ESR1 (steroid receptors) gene expression was downregulated (P = 0.057) in CA from placentitis mares. In conclusion, acute equine placentitis is associated with a local withdrawal of progestins in the placenta and tended to be accompanied with estrogen withdrawals in CA.
Publication Date: 2020-01-29 PubMed ID: 31990666DOI: 10.1530/REP-19-0420Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research explores how equine placentitis (an infection of the placenta in horses) affects steroid production and metabolism in the placental tissues, which could potentially influence pregnancy outcomes.
Study Design and Methods
- The team induced acute placentitis in four mares, and used four un-inoculated, age-matched mares as a control group.
- They collected samples from two types of tissues in the placenta: the Chorioallantois (CA) and the Endometrial (EN).
- The expression of genes coding for steroidogenic enzymes (which are responsible for the production of steroids) was measured using a technique called qRT-PCR. The investigated genes include: 3βHSD, CYP11A1, CYP17A1, CYP19A1, SRD5A1, and AKR1C23.
- With liquid chromatography-tandem mass spectrometry, they measured concentrations of steroids that these enzymes produce in both maternal blood and placental tissue.
Results and Findings
- The mRNA expression levels of SRD5A1 and AKR1C23—genes encoding the key enzymes for progesterone metabolism—were found to be lower in the CA from mares with placentitis compared to the control group.
- This decrease in gene expression corresponded with reductions in the tissue concentrations of several downstream steroid products (5αDHP, 3αDHP, and 3β-20αDHP).
- In the EN tissue, AKR1C23 expression was also lower in the placentitis group, which was associated with a decrease in concentrations of 3αDHP and 20αDHP.
- In the CA tissue, the expression of CYP19A1, a gene involved in estrogen synthesis, was lower in mares with placentitis; this was associated with a decrease in estrone (a form of estrogen) levels.
- Additionally, the research team found that the mRNA expression of ESR1, a gene responsible for encoding estrogen receptors, was downregulated in the placentitis mares’ CA tissues.
Conclusions
- From this study, it’s concluded that acute equine placentitis is associated with a withdrawal of progestins (a group of hormones that includes progesterone) in the placenta.
- The occurrence of placentitis also seemed to be associated with a decrease in the levels of estrogens in CA.
- This study elucidates some of the molecular changes regarding steroid synthesis and metabolism in equine placentitis, paving the way for further investigations into potential treatments for the affliction.
Cite This Article
APA
El-Sheikh Ali H, Legacki EL, Scoggin KE, Loux SC, Dini P, Esteller-Vico A, Conley AJ, Stanley SD, Ball BA.
(2020).
Steroid synthesis and metabolism in the equine placenta during placentitis.
Reproduction, 159(3), 289-302.
https://doi.org/10.1530/REP-19-0420 Publication
Researcher Affiliations
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Theriogenology Department, Faculty of Veterinary Medicine, University of Mansoura, Mansoura, Egypt.
- Department of Population Health and Reproduction, University of California, Davis, California, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, USA.
- Department of Population Health and Reproduction, University of California, Davis, California, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Department of Molecular Biosciences, University of California, Davis, California, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
MeSH Terms
- Animals
- Chorioamnionitis / enzymology
- Chorioamnionitis / pathology
- Chorioamnionitis / veterinary
- Estradiol Congeners / biosynthesis
- Female
- Horses / metabolism
- Placenta / enzymology
- Placenta / pathology
- Pregnancy
- Progesterone / biosynthesis
Citations
This article has been cited 4 times.- Orellana-Guerrero D, Uribe-Salazar JM, El-Sheikh Ali H, Scoggin KE, Ball B, Daels P, Finno CJ, Dini P. Dynamics of the Equine Placental DNA Methylome and Transcriptome from Mid- to Late Gestation. Int J Mol Sci 2023 Apr 11;24(8).
- Piotrowska-Tomala KK, Jonczyk AW, Szóstek-Mioduchowska AZ, Żebrowska E, Ferreira-Dias G, Skarzynski DJ. The Effects of Prostaglandin E(2) Treatment on the Secretory Function of Mare Corpus Luteum Depends on the Site of Application: An in vivo Study. Front Vet Sci 2021;8:753796.
- Scoggin KE, Rakha SI, Abdellatif AM, Adlan F, Helmy YA, Ruby R, Ball B, Boakari Y, Ali HE. Activation of the S100A8/A9 Alarmin Amplifies Inflammatory Pathways in Equine Ascending Placentitis. Int J Mol Sci 2026 Feb 4;27(3).
- Scoggin KE, Adlan F, Fedorka CE, Rakha SI, Stout TAE, Troedsson MHT, Ali HE. Gestation-Stage Related Changes in the IGF System Components in the Equine Placenta. Biomolecules 2025 Aug 6;15(8).
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