AMH induces a reversible quiescence-associated secretory phenotype in preantral follicles†.

Anti-Müllerian hormone (AMH) is a factor secreted by granulosa cells of growing follicles that regulates many aspects of ovarian function including primordial follicle activation and early follicle development through inhibitory feedback. Treatment with exogenous AMH at supraphysiological levels can inhibit follicular development and prevent ovulation in mice, rats, and cats. Single-cell transcriptomic analysis of ovaries from mice treated postnatally with AMH identified a distinct quiescence signature in granulosa cells. Herein, we further characterized the AMH-induced quiescent cell state and drew parallels to developmental senescence by describing a reversible "quiescence-associated secretory phenotype" or QASP. This state was characterized by the induction of several hallmarks of senescence, including inhibition of proliferation (reduced KI67), upregulation of markers of senescence (Cdkn1a, Fn1, Cebpb, Timp3), and chemokines and their receptors (Cxcl14, Cxcl12, Ccl12, Ccl21, Cxcr2). However, QASP did not recapitulate other senescence hallmarks, such as the activation of beta-galactosidase activity or permanent exit from the cell cycle. Similarly to classical senescence, we found that AMH induced QASP, in part, through the upregulation of cyclin-dependent kinase inhibitors (Cdkn1a, Cdkn1b, and Cdkn1c) in granulosa cells and oocytes of mouse and human ovaries. Finally, we showed that the QASP state could be reversed within a month of discontinuing AMH treatment. This recovery was marked by the return of growing primary, secondary, and antral follicles. In conclusion, these data suggest that AMH can pause follicle development by inducing QASP, a reversible senescent-like state, which may benefit fertility preservation.