Oridonin attenuates diabetic retinopathy progression by suppressing NLRP3 inflammasome pathway

Oridonin (Ori) possesses anti-inflammatory properties. However, its potential to treat diabetic retinopathy (DR) remains unclear. This study aimed to investigate the retinal protective function of Ori and the underlying mechanism. In streptozotocin-induced mice, Ori alleviated visual impairment, reduced retinal and vascular lesions, protected the neuroretinal structure, reversed retinal nerve layer thickening. Addtionnally, Ori reduced TNF-α and IL-1β levels in the peripheral blood, and suppressed retinal NLRP3 inflammasome-related inflammatory factor. In vitro, human retinal endothelial cells (hRECs) were stimulated by high glucose (HG). HG-stimulated hRECs activated the NLRP3 inflammasome, whereas Ori significantly alleviated pyroptosis by enhancing cell viability and reducing IL-1β levels in the supernatant. Ori also inhibited NF-κB/NLRP3 inflammasome pathway. NEK7 depletion alleviated NLRP3 inflammasome activation and, to some extent, mimicked the role of Ori. Indeed, Ori reversed NLRP3 inflammasome activation by suppressing NEK7-NLRP3 interaction. Therefore, Ori may serve as a potential therapeutic agent for attenuating DR progression.