Tanshinone IIA alleviates chronic endometritis via DRAK2 inhibition to restore mitochondrial function and suppress KDM3A-SLC2A3-driven NETs formation.

This study aimed to investigate the therapeutic potential of Tanshinone IIA (Tan-IIA) in alleviating chronic endometritis (CE), focusing on its role in mitigating mitochondrial dysfunction and suppressing neutrophil extracellular traps (NETs) formation. HEnEpCs were stimulated with lipopolysaccharide (LPS) to establish an inflammatory model. Application of Tan-IIA as a pretreatment was followed by a comprehensive assessment of mitochondrial function, including JC-1 staining, adenosine triphosphate (ATP) content, reactive oxygen species (ROS) levels, and transmission electron microscopy. A co-culture system with human neutrophils was used to evaluate NETs formation. Molecular mechanisms were probed using real-time quantitative PCR (RT-qPCR), Western blot, chromatin immunoprecipitation (ChIP), and immunofluorescence. A rat model of LPS-induced endometritis was used to validate the effects of Tan-IIA on uterine histopathology, NETs formation, and inflammatory cytokine levels. Tan-IIA significantly ameliorated LPS-induced mitochondrial damage, restored membrane potential, reduced ROS production, and increased ATP levels in HEnEpCs. DRAK2 was elevated in CE patient plasma and LPS-stimulated cells, of which overexpression antagonized protective effects mediated by Tan-IIA. Furthermore, Tan-IIA inhibited NETs formation in co-culture systems, an effect mediated through suppression of the lysine demethylase 3A (KDM3A)-histone H3 lysine 9 dimethylation (H3K9me2)-hypoxia-inducible factor 1-alpha (HIF-1A)-solute carrier family 2 member 3 (SLC2A3) epigenetic-metabolic axis. Tan-IIA reduced neutrophil infiltration, NETs formation, and pro-inflammatory cytokine levels to improve endometrial architecture in LPS-induced rats. Tan-IIA attenuates CE progression by targeting DRAK2 to restore mitochondrial function and inhibiting NETs formation via the KDM3A/SLC2A3 pathway, implying Tan-IIA as a promising multi-target agent for CE therapy.