Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition.
Abstract: This study aimed to gain insight on the effect of different seasons of the year on the expression pattern of growth factor and hormone receptors involved in follicle development. A novel follicle wall biopsy technique was used to collect in vivo follicle wall layers (ie, granulosa, theca interna, and theca externa) and follicular fluid samples from growing dominant follicles, simultaneously and repeatedly, using the same mares during the spring anovulatory (SAN), spring ovulatory (SOV), summer (SU), and fall ovulatory (FOV) seasons. The immunofluorescent expression patterns of epidermal growth factor receptor (EGFR), Ki-67, vascular endothelial growth factor receptor (VEGFR), and LH receptor (LHR) were evaluated in each follicle wall layer, in addition to intrafollicular estradiol and nitric oxide (NO). Proliferative proteins (EGFR and Ki-67) were highly (P < 0.05-P < 0.001) expressed during the SOV season compared with the SAN and FOV seasons. Lower (P < 0.05-P < 0.001) expression of both proteins was observed during SU compared with the SOV season. The expression of VEGFR was greater (P < 0.05-P < 0.01) in the theca interna of dominant follicles during the SOV season compared with the SAN and SU seasons. Similarly, in the overall quantification, the VEGFR expression was greater (P < 0.001) during the SOV season compared with the SU and FOV seasons. A higher (P < 0.05) LHR expression was detected in the theca interna during the SOV season than the SAN season. Furthermore, a higher (P < 0.05-P 0.05) among different seasons of the year. The intrafollicular estradiol concentration was higher (P < 0.05) during the SU compared with the SAN season and higher (P < 0.05) during the FOV season compared with the SAN and SOV seasons. In conclusion, the synergistic effect of lower expression of proliferative protein, angiogenic, and LH receptors in at least some of the layers of the follicle wall seems to trigger dominant follicles toward the anovulation process during the spring and fall transitional seasons.
Copyright © 2019 Elsevier Inc. All rights reserved.
Publication Date: 2019-07-31 PubMed ID: 31585312DOI: 10.1016/j.domaniend.2019.07.010Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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This research paper seeks to understand how the different seasons of the year affect the expression patterns of growth factors and hormone receptors involved in the development of follicles, particularly the process of anovulation in mares.
Research Methods
- The researchers used a new technique for taking biopsies from follicle walls in a live animal.
- Growth hormone and other factor receptors were sampled in these follicles during different seasons: spring anovulatory (SAN), spring ovulatory (SOV), summer (SU), and fall ovulatory (FOV).
- The markers they looked for included epidermal growth factor receptor (EGFR), Ki-67, vascular endothelial growth factor receptor (VEGFR), and LH receptor (LHR) in each follicle wall layer.
- Moreover, the levels of intrafollicular estradiol and nitric oxide (NO) were measured too.
Key Findings
- The proteins that are essential to the proliferation of cells, EGFR and Ki-67, were expressed mostly during the SOV season compared to SAN and FOV seasons. Paradoxically, expression of these proteins was observed to be lower during SUM compared to SOV.
- The expression of VEGFR, another important factor, was observed to be greater in the theca interna of dominant follicles during the SOV season compared to the SAN and SU seasons.
- The researchers also noticed that LH receptors had increased expression during the SOV season compared to the other seasons.
- In terms of intrafollicular nitric oxide concentration, there was no significant change throughout the different seasons.
- However, the concentration of intrafollicular estradiol was higher during SU compared with the SAN season, and higher in FOV season compared to both SAN and SOV seasons.
Conclusion
- The research concluded that the lower expression of proliferative proteins, angiogenic, and LH receptors in some layers of follicle wall may result in the activation of dominant follicles towards the anovulation process.
- This finding is of considerable significance and may provide some answers as to why mares may be more likely to experience anovulation during particular seasons (spring and fall transitional seasons) compared to others.
Cite This Article
APA
Ishak GM, Dutra GA, Gastal GDA, Elcombe ME, Gastal MO, Park SB, Feugang JM, Gastal EL.
(2019).
Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition.
Domest Anim Endocrinol, 70, 106382.
https://doi.org/10.1016/j.domaniend.2019.07.010 Publication
Researcher Affiliations
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA; Department of Surgery and Obstetrics, College of Veterinary Medicine, University of Baghdad, Baghdad, Iraq.
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, USA.
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, USA.
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA. Electronic address: egastal@siu.edu.
MeSH Terms
- Animals
- Cell Proliferation / physiology
- ErbB Receptors / genetics
- ErbB Receptors / metabolism
- Estradiol / genetics
- Estradiol / metabolism
- Female
- Gene Expression Regulation
- Horses / physiology
- Ki-67 Antigen / genetics
- Ki-67 Antigen / metabolism
- Luteinizing Hormone
- Neovascularization, Physiologic
- Ovarian Follicle / physiology
- Ovulation / physiology
- Receptors, LH / genetics
- Receptors, LH / metabolism
- Receptors, Vascular Endothelial Growth Factor / genetics
- Receptors, Vascular Endothelial Growth Factor / metabolism
- Seasons
- bcl-2-Associated X Protein
Citations
This article has been cited 1 times.- Bashir ST, Baerwald AR, Gastal MO, Pierson RA, Gastal EL. Dominant follicle growth patterns and associated endocrine dynamics in anovulatory and ovulatory waves in women. Reprod Fertil 2023 May 1;4(2).
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