Acupotomy Attenuates Pain Hypersensitivity and Annulus Fibrosus Injury-Associated Changes in a Rat Model of Non-Compressive Lumbar Disc Herniation: Links to XIST/miR-223-3p/NLRP3 Signaling

Background Lumbar disc herniation (LDH) involves inflammatory signaling, nociceptive sensitization, and disc-associated tissue injury. We examined whether acupotomy is associated with modulation of X-inactive specific transcript (XIST)/microRNA-223-3p (miR-223-3p)/NLR family pyrin domain containing 3 (NLRP3) signaling and pyroptosis-associated injury. Methods Male Sprague–Dawley rats received epidural autologous nucleus pulposus suspension to establish non-compressive LDH and were assigned to sham, LDH, or LDH + acupotomy groups ( n = 10/group). Acupotomy was applied on D1, D3, and D5; mechanical paw withdrawal threshold (PWT) and thermal paw withdrawal latency (PWL) were followed through D7. Annulus fibrosus (AF) histology, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL), quantitative reverse transcription polymerase chain reaction, and immunoblotting were assessed. RNA interactions were examined by prediction, dual-luciferase assays, and argonaute 2-RNA immunoprecipitation (Ago2-RIP). Primary rat AF cells were challenged with lipopolysaccharide (LPS)/adenosine triphosphate (ATP) and subjected to XIST knockdown and miR-223-3p inhibition. Results LDH reduced PWT and PWL and was accompanied by AF architectural disruption; increased TUNEL positivity; increased XIST, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and N-terminal fragment of gasdermin D (GSDMD-N); and reduced miR-223-3p. Acupotomy shifted these outcomes toward sham levels. Reporter assays and Ago2-RIP supported miR-223-3p interactions with XIST and NLRP3. In LPS/ATP-challenged AF cells, XIST knockdown improved viability and reduced NLRP3, GSDMD-N, and TUNEL positivity; miR-223-3p inhibition reversed these effects. Conclusions Acupotomy attenuated nociceptive hypersensitivity and was associated with reduced AF injury-related and inflammasome/pyroptosis-associated signaling. Cell-based rescue experiments support a functional XIST/miR-223-3p/NLRP3 regulatory link, while in vivo causal validation remains necessary.