Wnt/β-catenin signaling inhibits oxidative stress-induced ferroptosis to improve interstitial cystitis/bladder pain syndrome by reducing NF-κB.

BACKGROUND

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a bladder syndrome of unknown etiology. Reactive oxygen species (ROS) plays a major role in ferroptosis and bladder dysfunction of IC/BPS, while the role of ferroptosis in IC/BPS progression is still unclear. This study aims to investigate the role and mechanism of ROS-induced ferroptosis in IC/BPS using cell and rat model.

METHODS

We collected IC/BPS patient bladder tissue samples and established a LPS-induced IC/BPS rat model (LRM). The level of oxidative stress and ferroptosis in IC/BPS patients and LRM rats was analyzed. Function and regulatory mechanism of ferroptosis in IC/BPS were explored by in vitro and in vivo experiments.

RESULTS

The patients with IC/BPS showed mast cells and inflammatory cells infiltration in bladder epithelial tissues. Expression of NRF2 was up-regulated, and GPX4 was decreased in IC/BPS patients compared with normal tissues. IC model cells underwent oxidative stress, which induced ferroptosis. These above results were validated in LRM rat models, and inhibition of ferroptosis ameliorated bladder dysfunction in LRM rats. Wnt/β-catenin signaling was deactivated in IC/BPS patients and animals, and activation of Wnt/β-catenin signaling reduced cellular free radical production, thereby inhibited ferroptosis in IC model cells. Mechanistically, the Wnt/β-catenin signaling pathway inhibited oxidative stress-induced ferroptosis by down-regulating NF-κB, thus contributing to recover IC/BPS both in vitro and in vivo.

CONCLUSIONS

We demonstrate for the first time that oxidative stress-induced ferroptosis plays an important role in the pathology of IC/BPS. Mechanistically, the Wnt/β-catenin signaling suppressed oxidative stress-induced ferroptosis by down-regulating NF-κB to improve bladder injury in IC/BPS.