Qiming granules regulate Müller cell pyroptosis and the P2X7R/NLRP3 immune inflammatory pathway in diabetic retinopathy

Introduction: Müller cell Pyroptosis and immune inflammation-induced retinal ganglion cell (RGC) damage are the core pathological markers and potential therapeutic targets for neurodegeneration in early diabetic retinopathy (DR). Qiming Granules (QMG)-recommended by the traditional Chinese medicine guidelines for DR owing to their multi-target immunomodulatory, antioxidant, and microvascular protective effects. This study aimed to clarify the protective effect of QMG on early DR neurodegeneration, reveal their neuroprotective mechanism by regulating the P2X7R/NLRP3 pathway to inhibit Müller cell Pyroptosis and immune inflammation, identify the chemical components of QMG and its absorbed components in rat plasma, study the effects of major absorbed components on inhibiting Müller cells Pyroptosis and immune inflammatory response, and investigate the potential pharmacodynamic substances of QMG.

Methods: An in vivo DR neurodegeneration model was established. HE staining, transmission electron microscopy, WB, and ELISA were used for detecting RGC Apoptosis, histomorphological changes, P2X7R/NLRP3 expression, and Pyroptosis pathway proteins. An in vitro high-glucose-induced Müller cell Pyroptosis model was constructed. After activating or inhibiting P2X7R, Lactate Dehydrogenase levels were measured; moreover, ELISA, WB, and immunofluorescence were performed to examine cell membrane damage, inflammatory factor release, and Pyroptosis pathway protein expression. UPLC-Q-Orbitrap HRMS was utilized to characterize the chemical and blood-entering profiles of QMG, aiming to evaluate the inhibitory effects of its main blood components on high glucose-induced Müller cell Pyroptosis.

Results: QG inhibited RGC Apoptosis, the P2X7R/NLRP3 pathway, and retinal cell Pyroptosis in DR neurodegeneration model rats. In vitro, QMG reduced membrane rupture and Pyroptosis pathway protein expression in Müller cells by suppressing the P2X7R/NLRP3 pathway, ultimately inhibiting Müller cell Pyroptosis and immune-inflammatory responses. Nine of the 70 compounds identified in QMG were absorbed into the bloodstream. The main absorbed components, astragaloside IV and puerarin, effectively mitigated high glucose-induced Müller cell Pyroptosis, with astragaloside IV exhibiting a more pronounced effect.

Conclusions: QMG mitigated Müller cell Pyroptosis and inflammatory responses by regulating the P2X7R/NLRP3 pathway, thereby inhibiting early neurodegeneration in DR. Astragaloside IV and puerarin absorbed into systemic circulation, significantly attenuated high glucose-induced Pyroptosis, and suppressed immunoinflammatory responses in Müller cells.

Astragaloside IV; Diabetic retinopathy; Immune inflammation; Müller cell pyroptosis; Neurodegeneration; P2X7R/NLRP3; Puerarin; Qiming granules.