AMH/MIS as a contraceptive that protects the ovarian reserve during chemotherapy

Abstract

The ovarian reserve represents the stock of quiescent primordial follicles in the ovary which is gradually depleted during a woman's reproductive lifespan, resulting in menopause. Müllerian inhibiting substance (MIS) (or anti-Müllerian hormone/AMH), which is produced by granulosa cells of growing follicles, has been proposed as a negative regulator of primordial follicle activation. Here we show that long-term parenteral administration of superphysiological doses of MIS, using either an adeno-associated virus serotype 9 (AAV9) gene therapy vector or recombinant protein, resulted in a complete arrest of folliculogenesis in mice. The ovaries of MIS-treated mice were smaller than those in controls and did not contain growing follicles but retained a normal ovarian reserve. When mice treated with AAV9/MIS were paired with male breeders, they exhibited complete and permanent contraception for their entire reproductive lifespan, disrupted vaginal cycling, and hypergonadotropic hypogonadism. However, when ovaries from AAV9-MIS-treated mice were transplanted orthotopically into normal recipient mice, or when treatment with the protein was discontinued, folliculogenesis resumed, suggesting reversibility. One of the important causes of primary ovarian insufficiency is chemotherapy-induced primordial follicle depletion, which has been proposed to be mediated in part by increased activation. To test the hypothesis that MIS could prevent chemotherapy-induced overactivation, mice were given carboplatin, doxorubicin, or cyclophosphamide and were cotreated with AAV9-MIS, recombinant MIS protein, or vehicle controls. We found significantly more primordial follicles in MIS-treated animals than in controls. Thus treatment with MIS may provide a method of contraception with the unique characteristic of blocking primordial follicle activation that could be exploited to prevent the primary ovarian insufficiency often associated with chemotherapy.M üllerian inhibiting substance (MIS), also known as antiMüllerian hormone (AMH), has long been appreciated for its role in sex differentiation and reproduction, and sensitive ELISAs measuring blood levels are used in fertility clinics around the world as a measure of ovarian reserve (1-6). MIS plays important roles in the development of the gonad and the differentiation of the urogenital ridge. In the male fetus, MIS produced by the developing testes causes regression of the Müllerian duct (7). In the female fetus, MIS may play a role in early follicle assembly in the gonad by primordial germ cells (not to be confused with primordial follicles), since mice overexpressing MIS are devoid of germ cells shortly after birth (8), and, similarly, ex vivo incubation of fetal ovaries with MIS results in the inhibition of follicle assembly (9). These data highlight a role of MIS during fetal development that is distinct from its regulatory role of folliculogenesis postnatally.In the adult, MIS is produced predominantly by the cumulus (less so by the mural) granulosa cells of secondary and early antral...

Inhibitors of apoptosis protect the ovarian reserve from cyclophosphamide

“…1A). The mouse strains and the dose of CPA were selected based on those used in previous publications (Kalich-Philosoph et al 2013, Goldman et al 2017, Kano et al 2017. After 24 h, ovaries were harvested for histological analysis and follicle counting.…”

Anti-Müllerian hormone overexpression restricts preantral ovarian follicle survival

“…Alternatively, the collapse of the primordial follicle population may be indirect and subsequent to the profound effects on the developing follicle population. However, the possibility that prolonged elevation in AMH is toxic to dormant primordial follicles requires urgent investigation because AMH treatment has been proposed as a reversible contraceptive and a therapeutic inhibitor of ovarian reserve depletion (Margolskee & Selgrade 2013, Hayes et al 2016, Kong et al 2016, Kano et al 2017. The loss of primordial follicles is thought to be irreversible and the 5-month-old Thy1.2-AMH Tg phenotype indicates that more research is needed to determine the safety of longterm AMH treatment.…”

A win-win for women’s reproductive health: A nonsteroidal contraceptive and fertoprotective neoadjuvant

“…This powerful reproductive tract-regulating hormone has no known effect on adult male fertility; however, in the female, it takes on a completely different role that is necessary for follicle activation. The paper by Kano et al (1) details this function using a gene therapy approach that produces chronic, systemic hormone resulting in complete contraception-in other words, absence of follicle activation (Fig. 1).…”

“…The biological isolation of this million-follicle ovarian reserve is changed when individual follicles are activated through signaling mechanisms that are now known, but by factor(s) that have remained elusive. One of the key paracrine-acting factors that controls early follicle activity is Müllerian inhibiting substance/antiMüllerian hormone (MIS/AMH), and its profound role on the entire ovarian reserve is elegantly described by Kano et al (1) …”