Electroacupuncture Attenuates Cyclophosphamide-Induced Bladder Pain by Restoring Autophagy in Spinal Inhibitory...

Interstitial cystitis/bladder pain syndrome is characterized by chronic pelvic pain and urinary symptoms. Autophagy and oxidative stress are essential to neuronal homeostasis, and their dysregulation in spinal circuits may contribute to persistent pain. While electroacupuncture (EA) has been reported to alleviate cystitis-related pain, the associated cellular changes in the spinal dorsal horn remain incompletely understood. In this study, we used the cyclophosphamide (CYP)-induced cystitis rat model to investigate the cellular and molecular mechanisms underlying the analgesic effects of EA. Behavioral assessments, Western blotting, and immunofluorescence staining were employed to characterize phenotypic and molecular changes in the lumbosacral dorsal horn. GAD67-GFP mice were used for immunofluorescence-based identification of inhibitory neurons. We found that CYP produced persistent mechanical hypersensitivity accompanied by increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunoreactivity, elevated p62/SQSTM1, reduced Beclin-1 expression and decreased LC3B-related indices, and fewer autophagosomes in neurons; 8-OHdG and p62 signals were enriched in neuronal populations including GAD67-GFP-positive cells. EA treatment significantly reduced the mechanical allodynia induced by CYP, decreased 8-OHdG immunoreactivity, improved mitochondrial ultrastructural features, reduced p62 accumulation, increased Beclin-1 expression and improved LC3B-related indices, and increased autophagosome numbers in the dorsal horn. These data suggest that CYP-induced cystitis is associated with increased oxidative damage and impaired autophagy in dorsal horn neurons, and that sacral EA partially normalizes these measures.