METABOLIC REPROGRAMMING AS A STRATEGY TO DISARM NEURO-INFLAMMATION IN ENDOMETRIOSIS: A PRECLINICAL ASSESSMENT OF PYRUVATE DEHYDROGENASE KINASE INHIBITION

Abstract

Objective Endometriosis (EMS) is characterized by ectopic endometrial lesions, chronic inflammation, and intractable pain driven by peripheral and central nociceptive sensitization. Endometriotic cells and associated immune cells exhibit metabolic reprogramming known as the Warburg effect, primarily regulated by Pyruvate Dehydrogenase Kinase (PDK). This preclinical study aimed to assess whether pharmacological inhibition of PDK using Dichloroacetate (DCA) could disarm the chronic neuro-inflammatory cascade and alleviate pain symptoms in a syngeneic mouse model of EMS. Methods A syngeneic mouse model of surgically induced endometriosis was established in immunocompetent C57BL/6 mice. After lesion establishment (4 weeks post-surgery), mice were treated orally with DCA ($12.5\ \text{mg/kg}$ twice daily) or vehicle for 4 weeks. Efficacy was assessed using multi-modal endpoints: behavioral pain tests (Von Frey, spontaneous behaviors), biochemical analysis (lesion lactate, peritoneal cytokines TNF-$\alpha$ and IL-1$\beta$), and histology (nerve density via PGP9.5/CGRP, mast cell activity via Tryptase, and central glial activation markers GFAP/Iba-1 in the spinal cord). Results DCA treatment significantly attenuated the Warburg phenotype, evidenced by a marked reduction in lesion lactate concentrations and decreased phosphorylation of the Pyruvate Dehydrogenase Complex (PDH). Behaviorally, DCA reversed mechanical hyperalgesia and significantly reduced spontaneous pain behaviors compared to vehicle controls. This functional improvement correlated with profound anti-inflammatory effects: Peritoneal fluid analysis demonstrated substantial reductions in pro-inflammatory cytokines. Furthermore, neuro-histological assessment showed reduced density of PGP9.5-positive nerve fibers and decreased tryptase-positive mast cell proximity to neural structures within the lesions. Crucially, DCA treatment mitigated central sensitization, manifesting as decreased immunoreactivity for the glial activation markers GFAP and Iba-1 in the lumbar spinal dorsal horn. Conclusions PDK inhibition effectively targets the metabolic and inflammatory drivers of endometriosis pathogenesis. By restoring mitochondrial oxidative phosphorylation (OXPHOS) and shifting immune cell polarization away from the pro-inflammatory phenotype, DCA successfully disrupts the neuro-inflammatory loop. This intervention offers a novel, non-hormonal therapeutic strategy for managing endometriosis-associated chronic pain, acting on both peripheral lesion sites and central sensitization pathways.