NCBI Summary:
This gene encodes a member of the TGF-beta (transforming growth factor-beta) superfamily of proteins. The encoded preproprotein is proteolytically processed to generate an inhibin beta subunit. Inhibins have been implicated in regulating numerous cellular processes including cell proliferation, apoptosis, immune response and hormone secretion. This gene may be upregulated under conditions of endoplasmic reticulum stress, and this protein may inhibit cellular proliferation and growth in pancreas and liver. [provided by RefSeq, Sep 2016]
General function
Ligand
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Cellular localization
Secreted
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Ovarian function
Preantral follicle growth
Comment
Activin effects on follicular growth in in vitro preantral follicle culture. Tanaka Y et al. (2019) As the follicular environment transits from being activin dominant to inhibin dominant during folliculogenesis, it is assumed that activin plays an important role in the early stage of follicular growth. We examined the effects of activin on morphological, biochemical and molecular changes in isolated preantral follicles. Preantral follicles were mechanically isolated from 14-day old female C57BL/6 mice. Each follicle was cultured and observed for 14 days usingan in vitro follicle culture system containing FSH, FSH + activin A and FSH + inhibin in the culture medium. We subsequently examined FSH receptor (FSH-R) mRNA expression in isolated follicle cultures with or without activin on days 0 and 2. Activin was observed to significantly stimulate follicle enlargement on days 2, 4, 6 and 8, accelerate morphological changes and increase estradiollevels in culture medium on days 4, 12 and 14. In contrast, inhibin did not alter follicular growth. Additionally, activin stimulated the expression of FSH-R mRNA in isolated granulosa cells. It was demonstrated that activin stimulated the growth of preantral follicles, mainly during the early stage of folliculogenesis, by inducing FSH-R expression, in an isolated follicle culture system. J. Med. Invest. 66 : 165-171, February, 2019.//////////////////
Expression regulated by
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Ovarian localization
Comment
Development and characterisation of an antibody for the immunohistochemical detection of inhibin/activin betaE (betaE) in normal human ovarian and placental tissue. Mylonas I et al. Inhibin/activin subunits are homologues to each other and belong to the transforming growth factor-beta (TGF-beta) family of proteins. These proteins have been demonstrated to be disulphide-linked dimers, which have a common alpha-subunit but just one of two beta-subunits, differentiated in inhibin A (alpha-betaA) and in inhibin B (alpha-betaB). Recently, an additional beta-subunit has been identified, determined as betaE and being primarily synthesized in liver tissue. However, since no antibody against the betaE subunit is commercially available, limited data on histological immunodistribution of this inhibin subunit in gynaecological organs exist. Therefore, the aims of the present study were the synthesis and evaluation of a specific antibody against the inhibin-betaE subunit. In this study, we describe the characterisation of a polyclonal antibody against the inhibin-betaE subunit. This antibody demonstrated a specific reaction in both western blot analysis and immunohistochemistry. Moreover, we demonstrated positive immunolabelling in normal human ovary and placenta. The role of this novel subunit is intriguing, especially within the view that the other inhibin/activin subunits might have substantial functions in human reproduction and carcinogenesis. However, the function of this subunit in humans remains still unclear and warrants further research.