The Effect Of Nesfatin-1 On Trigeminal Neuralgia In Mouse And Its Mechanism

Objective:To study the effect of nesfatin-1 on mouse trigeminal neuralgia and its intracellular mechanism.Methods:Through acute isolation and primary culture of mouse trigeminal neurons,the effect of nesfatin-1 on its A-type potassium channel was investigated by whole-cell patch clamp method.Western blot was used to detect the expression of nesfatin-1 receptors.Immunofluorescence was used to detect the distribution of receptors.The excitatory changes of nesfatin-1 on trigeminal neurons in mice were detected by whole cell patch clamp method,and the Von Frey method was used to test nesfatin-1 for facial pain in mice at the behavioral level threshold effect.Explore the regulatory role of nesfatin-1 receptor CRFRi(Corticotropin releasing hormone receptor 1)in Trigeminal neuralgia in mice.Results:The results of this study showed that(1)The inhibition rate of 1 nM nesfatin-1 on mouse trigeminal neuron A-type potassium channels reached 28.9±1.3%.In the subsequent electrophysiological records of different concentrations,we found that this inhibition was significantly concentration-dependent.(2)The inhibitory effect of nesfatin-1 can be inhibited by GDP-?-S(specific G protein activity inhibitor),NBI27914(CRFRi specific blocker);Moreover,PKI6-22 and H-89,selective blockers of protein kinase A(PKA),can also block this inhibitory effect.However,GF109203X,a selective inhibitor of protein kinase C(PKC),failed to block the inhibitory effect of nesfatin-1 on mouse trigeminal neuron A-type potassium currents.(3)Western blot and immunofluorescence experiments showed that CRFRi expression was mainly distributed in trigeminal neurons with small and medium diameters.(4)Nesfatin-1 can significantly increase its action potential frequency,and NBI27914 can block this effect.(5)Injecting nesfatin-1(2.0 ?g/kg)into the mouse's face can reduce the facial pain threshold.(6)The expression level of CRFRi in the trigeminal mice of the CFA(Complete Freund's Adjuvant)model was significantly increased,and the blocker NBI27914 can relieve trigeminal neuralgia caused by CFA.Conclusion:Nesfatin-1 first acts on CRFR1,which in turn activates PKA,and then phosphorylates JNK to inhibit A-type potassium channels,and this inhibition is concentration-dependent.In addition,nesfatin-1 can enhance the firing frequency of trigeminal neurons in mice,thereby acting as a threshold for facial mechanical pain in mice,and the expression of CRFR1 was also increased in the model of facial inflammatory pain.