# USP9X-triggered ferroptosis mediates follicular atresia via deubiquitinating Beclin1 in chicken

## TL;DR

This study shows that USP9X promotes ferroptosis in chicken follicles, leading to follicular atresia through the deubiquitination of Beclin1.

## Contribution

The study identifies a novel USP9X-Beclin1 pathway linking ferroptosis and autophagy in avian follicular atresia.

## Key findings

- USP9X is upregulated in granulosa cells during follicular atresia and promotes ferroptosis.
- USP9X stabilizes Beclin1 via deubiquitination, activating autophagy-dependent ferroptosis.
- Inhibiting ferroptosis or autophagy reduces follicular degeneration in chickens.

## Abstract

Follicular atresia, a complex degenerative process regulated by multiple molecular mechanisms, significantly affects female reproductive performance in animals. While granulosa cell (GC) apoptosis has been well established as a primary mechanism underlying follicular atresia, the potential involvement of ferroptosis, which is an iron-dependent form of regulated cell death, remains largely unexplored in chickens.

Using a tamoxifen (TMX)-induced avian model of follicular atresia, we demonstrated that ferroptosis plays a critical role in follicular degeneration. Inhibition of ferroptosis through pharmacological agents significantly restored follicular function, underscoring its potential as a therapeutic target. Notably, we observed a significant upregulation of ubiquitin-specific peptidase 9, X-linked (USP9X) in GCs during atresia. Through comprehensive in vitro and in vivo investigations, we confirmed that USP9X facilitates follicular atresia by promoting ferroptosis in GCs. Mechanistically, USP9X induces ferroptosis by stabilizing Beclin1 through deubiquitination, thereby activating autophagy-dependent ferroptosis. This pathway was effectively suppressed by autophagy inhibitors, emphasizing the essential role of autophagy in USP9X-mediated ferroptosis.

Our findings provide the evidence that the USP9X-Beclin1 axis regulates autophagy-dependent ferroptosis during avian follicular atresia. These insights reveal novel molecular targets and potential genetic markers for improving reproductive efficiency in chicken breeding programs.

The online version contains supplementary material available at 10.1186/s40104-025-01269-8.