OBJECTIVE Trigeminal pain is mostly uni-lateral orofacial,but pain sensitization often spreads to contralateral orofacial or distal body regions.Widespread trigeminal pain has more severe intensity,longer dura-tion,and wider distribution,accompanied by more serious comorbid emotional syndrome.Unfortunately,the first-line analgesics for neuropathic pain has limited effect on widespread pain along with unavoidable side effects.In-depth understanding of the pathogenesis of wide-spread trigeminal pain is urgently needed.METHODS Trigeminal pain was induced by partial transection of the infraorbital nerve(p-IONX)and evaluated by measur-ing nociceptive thresholds to mechanical or heat stimula-tion.Neuronal activity was evaluated by single-unit and patch clamp recordings.HMGB1 expression was mea-sured by immunohistochemistry.Antagonism of HMGB1 was achieved by injecting anti-HMGB1 monoclonal anti-body(mAb)intracerebrally or intraperitoneally.RESULTS P-IONX model induced not only orofacial algesia but also somatic algesia in hind paw.Spontaneous firing frequency of glutamatergic neurons in the ventral posteromedial tha-lamic nucleus(VPMGlu)as well as the amplitude and fre-quency of sEPSCs significantly increased after p-IONX.Moreover,calcium signal recording showed that VPMGlu became to be activated by the noxious mechanical stimu-lation given on the hind paw,suggesting that VPMGlu recruited somatic afferents after p-IONX.We further explored the upstream brain regions of VPMGlu by virus retrograde tracing.We found the afferents from the grac-ile nucleus/cuneate nucleus(Gr/Cu),which are involved in the conduction of somatic sensation,markedly increased.And chemogenetical inhibiting Gr/Cu-VPM circuit alleviated the widespread neuropathic pain.In addition,the expression of HMGB1 in the VPM was sig-nificantly increased after p-IONX.Local administration of anti-HMGB1 mAb in the VPM relieved widespread neuro-pathic pain in mice receiving p-IONX.CONCLUSION These results demonstrate that the remodeling of affer-ent neurons in VPM underlie the spreading of wide-spread trigeminal neuropathic pain.Highly expressed HMGB1 in VPM plays an important role in these patho-logical changes after nerve injury and systemic adminis-tration of anti-HMGB1 mAb concurrently relieves wide-spread pain.

Background: The anti-programmed death 1 (PD-1) antibody has led to durable clinical responses in a wide variety of human tumors. We have previously developed the caninized anti-canine PD-1 antibody (ca-4F12-E6) and evaluated its therapeutic properties in dogs with advance-staged oral malignant melanoma (OMM), however, their therapeutic effects on other types of canine tumors remain unclear. Objective: The present clinical study was carried out to evaluate the safety profile and clinical efficacy of ca-4F12-E6 in dogs with advanced solid tumors except for OMM. Methods: Thirty-eight dogs with non-OMM solid tumors were enrolled prospectively and treated with ca-4F12-E6 at 3 mg/kg every 2 weeks of each 10-week treatment cycle. Adverse events (AEs) and treatment efficacy were graded based on the criteria established by the Veterinary Cooperative Oncology Group. Results: One dog was withdrawn, and thirty-seven dogs were evaluated for the safety and efficacy of ca-4F12-E6. Treatment-related AEs of any grade occurred in 13 out of 37 cases (35.1%).Two dogs with sterile nodular panniculitis and one with myasthenia gravis and hypothyroidism were suspected of immune-related AEs. In 30 out of 37 dogs that had target tumor lesions, the overall response and clinical benefit rates were 6.9% and 27.6%, respectively. The median progression-free survival and overall survival time were 70 days and 215 days, respectively. Conclusions The present study demonstrated that ca-4F12-E6 was well-tolerated in nonOMM dogs, with a small number of cases showing objective responses. This provides evidence supporting large-scale clinical trials of anti-PD-1 antibody therapy in dogs.