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CYP26A1-specific antagonist influence on embryonic implantation, gene expression and endogenous retinoid
Britta Fritzsche1, Jan-Philipp Schuchardt, Anja Schmidt
1Institute of Nutritional Science, Department of Physiology and Pathophysiology of Nutrition, University of Potsdam, Nuthetal, Germany. britta.fritzsche@gmail.com
Abstract:
Retinoids are essential in vertebrate reproduction and embryonic development. All-trans-retinoic acid (ATRA) is tightly regulated during these processes. CYP26A1 is mainly responsible for its degradation. To study the role of CYP26A1 during implantation, we applied R115866, a CYP26A1-specific antagonist, to rats during early gestation days (GD). On GD 6.5 and 12 samples were collected and the number of embryos was evaluated. ATRA concentration increased in uterus and serum, mRNA expression of CYP26A1 and CRABP2 increased in the liver, but not in the uterus. Uterine COX1 and 17βHSD mRNA expression was decreased. The number of embryos on GD 12 was not altered in this setting. It can be concluded that uterine expression of the analyzed retinoid-response genes during early gestation is not altered by this R115866 treatment and instead indirectly via ATRA. From our experiment we cannot confirm that ATRA obtains a major influencing role in the regulation of embryonic implantation.
Insights
This study investigated the role of CYP26A1 in rat embryo implantation. Blocking CYP26A1 increased all-trans-retinoic acid (ATRA) but did not affect embryo numbers, suggesting ATRA may not be crucial for implantation.
Area of Science:
- Reproductive biology
- Developmental biology
- Endocrinology
Background:
- Retinoids, including all-trans-retinoic acid (ATRA), are critical for vertebrate reproduction and embryonic development.
- ATRA levels are tightly regulated, with CYP26A1 primarily responsible for its degradation.
Purpose of the Study:
- To investigate the role of CYP26A1 in embryonic implantation using a specific antagonist.
- To assess the impact of altered ATRA metabolism on uterine gene expression and embryo development during early gestation.
Main Methods:
- Administration of R115866, a CYP26A1 antagonist, to pregnant rats during early gestation days (GD).
- Evaluation of embryo numbers on GD 6.5 and 12.
- Measurement of ATRA concentrations in uterine and serum samples.
- Analysis of mRNA expression for CYP26A1, CRABP2, COX1, and 17βHSD in uterine and liver tissues.
Main Results:
- R115866 treatment led to increased ATRA concentrations in the uterus and serum.
- mRNA expression of CYP26A1 and CRABP2 increased in the liver, but not the uterus.
- Uterine expression of COX1 and 17βHSD mRNA decreased.
- No significant alteration in the number of embryos was observed on GD 12.
Conclusions:
- Uterine expression of retinoid-response genes during early gestation is not directly altered by R115866 treatment.
- The observed changes in gene expression appear to be indirect effects mediated by ATRA.
- The study could not confirm a major role for ATRA in regulating embryonic implantation based on the experimental conditions.
