TrkB agonist antibody ameliorates fertility deficits in aged and cyclophosphamide-induced premature ovarian failure model mice

Qin et al. report that an agonistic antibody targeting the BDNF receptor TrkB promotes follicle development and oocyte maturation, and reverse ovarian deficits and infertility in aged and cyclophosphamide-induced premature ovarian failure model mice. Premature ovarian failure (POF) is a leading cause of women's infertility without effective treatment. Here we show that intravenous injection of Ab4B19, an agonistic antibody for the BDNF receptor TrkB, penetrates into ovarian follicles, activates TrkB signaling, and promotes ovary development. In both natural aging and cyclophosphamide-induced POF models, treatment with Ab4B19 completely reverses the reduction of pre-antral and antral follicles, and normalizes gonadal hormone. Ab4B19 also attenuates gonadotoxicity and inhibits apoptosis in cyclophosphamide-induced POF ovaries. Further, treatment with Ab4B19, but not BDNF, restores the number and quality of oocytes and enhances fertility. In human, BDNF levels are high in granulosa cells and TrkB levels increase in oocytes as they mature. Moreover, BDNF expression is down-regulated in follicles of aged women, and Ab4B19 activates TrkB signaling in human ovary tissue ex vivo. These results identify TrkB as a potential target for POF with differentiated mechanisms, and confirms superiority of TrkB activating antibody over BDNF as therapeutic agents.

Automated summary

The agonistic antibody targeting the BDNF receptor TrkB can promote follicle development and oocyte maturation, reverse ovarian deficits and infertility in models of premature ovarian failure. The antibody activates TrkB signaling and restores the number and quality of oocytes and enhances fertility. This study identifies TrkB as a potential target for treating premature ovarian failure.