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Walton KL, Goney MP, Peppas Z, Stringer JM, Winship A, Hutt K, Goodchild G, Maskey S, Chan KL, Brûlé E, Bernard DJ, Stocker WA, Harrison CA. Inhibin Inactivation in Female Mice Leads to Elevated FSH Levels, Ovarian Overstimulation, and Pregnancy Loss. Endocrinology 2022; 163:6543938. [PMID: 35255139 PMCID: PMC9272799 DOI: 10.1210/endocr/bqac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Indexed: 11/21/2022]
Abstract
Inhibins are members of the transforming growth factor-β family, composed of a common α-subunit disulfide-linked to 1 of 2 β-subunits (βA in inhibin A or βB in inhibin B). Gonadal-derived inhibin A and B act in an endocrine manner to suppress the synthesis of follicle-stimulating hormone (FSH) by pituitary gonadotrope cells. Roles for inhibins beyond the pituitary, however, have proven difficult to delineate because deletion of the inhibin α-subunit gene (Inha) results in unconstrained expression of activin A and activin B (homodimers of inhibin β-subunits), which contribute to gonadal tumorigenesis and lethal cachectic wasting. Here, we generated mice with a single point mutation (Arg233Ala) in Inha that prevents proteolytic processing and the formation of bioactive inhibin. In vitro, this mutation blocked inhibin maturation and bioactivity, without perturbing activin production. Serum FSH levels were elevated 2- to 3-fold in InhaR233A/R233A mice due to the loss of negative feedback from inhibins, but no pathological increase in circulating activins was observed. While inactivation of inhibin A and B had no discernible effect on male reproduction, female InhaR233A/R233A mice had increased FSH-dependent follicle development and enhanced natural ovulation rates. Nevertheless, inhibin inactivation resulted in significant embryo-fetal resorptions and severe subfertility and was associated with disrupted maternal ovarian function. Intriguingly, heterozygous Inha+/R233A females had significantly enhanced fecundity, relative to wild-type littermates. These studies have revealed novel effects of inhibins in the establishment and maintenance of pregnancy and demonstrated that partial inactivation of inhibin A/B is an attractive approach for enhancing female fertility.
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Affiliation(s)
- Kelly L Walton
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
- Correspondence: Kelly L Walton, PhD, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia 4072.
| | - Monica P Goney
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Zoe Peppas
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Jessica M Stringer
- Department of Anatomy and Developmental Biology Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Amy Winship
- Department of Anatomy and Developmental Biology Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Karla Hutt
- Department of Anatomy and Developmental Biology Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Georgia Goodchild
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Shreya Maskey
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Karen L Chan
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Emilie Brûlé
- Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
| | - Daniel J Bernard
- Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - William A Stocker
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Australia
| | - Craig A Harrison
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Correspondence: Craig A Harrison, PhD, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia 3168.
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