Inhibition of the NF-κB/STAT3 pathway to reduce spinal microglia activation: a mechanism by which manual acupuncture alleviates rheumatoid arthritis

Background: Rheumatoid arthritis (RA) discomfort is linked to spinal cord microglia activation. Manual acupuncture (MA, twirling manipulation) reduces RA pain. MA's ability to relieve RA discomfort was examined in this study.

Methods: After receiving complete Freund's Adjuvant (CFA), RA rats received acupuncture (with or without twisting manipulation). Paw withdrawal latency (PWL), nociceptive threshold, and hematoxylin and eosin (H&E) staining assessed arthritis severity. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the levels of inflammatory factors (IL-1β, TNF-α and IL-6) in the spinal dorsal horn. Immunofluorescence was used to assess the expression of p-p38 and Iba-1 in the ipsilateral hippocampus and ipsilateral (right) dorsal root ganglia (DRG). Western blot was used to evaluate the expression of proteins linked to the nuclear factor kappa-B (NF-κB) /signal transducer and activator of transcription 3 (STAT3) pathway.

Results: MA treatment enhanced PWL, inhibited the expression of spinal dorsal horn inflammatory factor and the activation of ipsilateral DRG or ipsilateral hippocampal microglia, also down-regulated NF-κB/STAT3 pathway proteins. The effect of MA on RA symptoms was better than acupuncture alone.

Conclusions: Our findings demonstrate that MA significantly ameliorates pain in CFA-induced RA rats. The novelty of this study lies in identifying that this analgesic effect is achieved through the inhibition of the NF-κB/STAT3 signaling pathway, leading to a marked reduction in spinal microglia activation.

Manual acupuncture; Microglia; Nuclear factor kappa-B; Rheumatoid arthritis; Signal transducer and activator of transcription3.