NLRP3 inhibitors(Nanjing University of Chinese Medicine)

Migraine is a common disorder that affects more than a billion of people worldwide, with an incidence in women three times higher than in men. The medical need for new therapeutic treatments is only partially satisfied by innovative approaches, and a significant percentage of migraineurs are still not satisfied with their therapy. Several lines of evidence links migraine to the activation of the NLRP3-IL-1β pathway. The aim of this research was to test whether NLRP3 blockers may represent innovative therapeutics for migraine. A well-established murine migraine model triggered by nitroglycerine (GTN) was used, together with NLRP3 knockout (Nlrp3^(-/-)) mice and the NLRP3 inhibitor MCC950. Both genetic and pharmacological blockade of NLRP3 were effective in reducing and preventing the onset of the periorbital mechanical allodynia (PMA) evoked by GTN in female mice, but not in males. The chronic administration of MCC950 was sufficient to induce PMA on its on, suggesting that the chronic treatment with a NLRP3 blocker may induce medication overuse headache as a side effect. Western blot analysis showed the activation of the NLRP3 pathway in the hippocampus of female mice treated with GTN, but not in their trigeminal ganglion, trigeminal nucleus caudalis and cortex. No activation of the NLRP3 pathway was detected in male mice. Collectively, this study strengthens the view that NLRP3 inhibitors may represent innovative migraine treatments. However, at the same time, it underlines for the first time some limitations that may affect NLRP3 inhibitors, namely sexual dimorphism in drug responsiveness and issues related to their chronic use.

Diabetic encephalopathy (DE) is a significant complication of diabetes mellitus, primarily characterized by cognitive impairment. Pyroptosis-mediated neuronal pyroptosis is a key factor in diabetes-induced cognitive dysfunction. Research indicates that using NLRP3 inhibitors to block NLRP3 inflammasome activation or employing H₂S to inhibit NF-κB activation can decrease pyroptosis and improve cognitive dysfunction in DE mice. Here, our aim is to design a bifunctional compound that can simultaneously inhibit the activation of NLRP3 and NF-κB to synergistically suppress neuronal pyroptosis for the clinical treatment of DE. This study reports the novel compound CYT-1, which significantly reduces levels of pyroptosis pathway proteins (p-NF-κB, NLRP3, Caspase-1, and GSDMD-N) and inflammatory factors (IL-1β and IL-18) in vitro. CYT-1 markedly increases H₂S concentrations in both the serum and hippocampus of mice with DE. Western blotting and Nissl staining demonstrated that CYT-1 notably decreased pyroptosis-related protein levels and enhanced hippocampal neuron counts in vivo. The findings demonstrate that CYT-1 synergistically inhibits neuronal pyroptosis by concurrently suppressing NF-κB activation and NLRP3 inflammasome activity. This study may provide new ideas for drug research and clinical treatment of DE.