Electroacupuncture Attenuates Mice Fibromyalgia Pain Through Increased PD-1 Expression in Mice

Fibromyalgia is a disease difficult to cure that causes chronic long-term pain, with symptoms lasting for months to years. Given the lack of evidence-based diagnosis and assessment methods for fibromyalgia, it ranks among the most difficult chronic pain conditions to treat. Programmed cell death ligand 1 (PD-L1) can inhibit acute and chronic pain transmission by inhibiting neuronal ion channels. Here, we aimed to explore the analgesic efficacy and mechanism of PD-L1/PD1 in a mouse fibromyalgia pain model. We used intermit-tent cold stress (ICS) to induce fibromyalgia in mice, this model was characterized by von Frey and Har-greaves’ tests. ICS-induced fibromyalgia pain mouse model exhibited mechanical and thermal hyperalgesia. Electroacupuncture (EA) or intraventricular PD-L1 injection effectively alleviated the nociceptive response and exhibited low PD-1 levels in the mouse dorsal root ganglia, spinal cord, thalamus, somatosensory cortex, and cerebellum. In contrast, pain-related kinase levels increased after fibromyalgia induction, and these effects was reversed by EA or PD-L1 via inhibition of microglia/astrocytes and toll-like receptor 4. Our results show that EA can treat fibromyalgia pain in mice through the PD-L1/PD1 pathway, indicating its therapeutic po-tential as a target in fibromyalgia.