癫痫在临床上较为常见，属于慢性疾病的一种，是因大脑神经元突发性异常放电导致的短暂大脑功能障碍。目前，临床对于癫痫的病因仍存在一定争议。随着临床对癫痫研究的不断深入，有遗传学与生物学研究表明，神经元细胞核中编码离子通道的基因突变导致膜通道蛋白改变引起通道性质与结构的变化与癫痫发病密切相关，而电压门控钠离子通道蛋白在其中扮演着非常重要的角色，它们通过打开与关闭能控制细胞电流的变化，实现对大脑神经元放电的调节。本文主要探讨编码钠离子通道Nav1.7的SCN9A基因与癫痫发病的相关性，旨在为临床癫痫的诊治提供理论参考。

目的:探讨miR-193a调控颞下颌关节骨关节炎症进展的作用机制.方法:构建颞下颌关节炎大鼠模型,将大鼠根据转染情况分为Control、Model、miR-NC、miR-193a、miR-193a+LiCl(Wnt/β-catenin通路激活剂)组,检测大鼠疼痛学行为,RT-qPCR检测颞下颌关节组织miR-193a表达情况,Western blot检测β-catenin、基质金属蛋白酶、Nav1.7 表达;ELISA检测炎症细胞因子;免疫组化检测CD68 和iNOS表达.结果:过表达miR-193a可增加大鼠摆头阈值、IL-10 表达水平,抑制β-catenin、基质金属蛋白酶、Nav1.7、TNF-α、IL-1β、IL-6、IL-23、CD68、iNOS表达水平(P<0.05).激活β-catenin显著逆转了过表达miR-193a对上述指标的影响(P<0.05).结论:过表达miR-193a可通过β-catenin减缓调控颞下颌关节骨关节炎症进展.

骨关节炎(osteoarthritis,OA)是常见的关节疾病.目前还没有能够同时防止关节退化和减少疼痛的治疗方法.有证据表明软骨细胞中存在电压门控钠通道(voltage gated sodium channels,VGSCs),但它们在软骨细胞和OA中的表达和功能仍不清楚.该研究发现,Nav1.7作为一个与OA相关的VGSCs,人OA软骨细胞以0.1～0.15个/μm2 和350～525个通道/细胞的密度表达功能性Nav1.7.在通过基因操作抑制Nav1.7的一系列小鼠模型上发现,表达在背根神经节(dorsal root ganglion,DRG)神经元中的Nav1.7参与疼痛的调控,而表达在软骨细胞中的Nav1.7调节OA进程.使用选择性或临床常用的泛Nav通道阻断剂,可显著改善结构性关节损伤,并减轻OA疼痛.Nav1.7阻断剂调节细胞内Ca2+信号和软骨细胞的分泌组,进而影响软骨细胞生物学和OA进程.该研究证实,Nav1.7为一个新发现的、在软骨细胞表达的OA相关VGSCs,可作为具有双重靶点特性的用于治疗OA和镇痛的非阿片类镇痛药.

目的:探讨脂多糖(LPS)是否及如何上调大鼠三叉神经节(TG)内Nav1.7的表达,从而调控大鼠颞下颌关节(TMJ)炎性痛.方法:选择成年雄性SD大鼠,应用大鼠三叉神经节脑立体定位实验,于活体大鼠TG内微量注射LPS,观察大鼠摆头阈值的变化,并检测TG内Nav1.7的表达.将大鼠TG进行体外离体培养,LPS单独或联合卫星胶质细胞(SGC)活化抑制剂fIuorocitrate(FC)、NF-κB抑制剂PDTC进行处理.应用实时定量PCR、Western免疫印迹实验检测TG内Nav1.7、p-p65、GFAP等分子的表达变化.采用SPSS 22.0软件包对数据进行统计学分析.结果:活体大鼠TG内微量注射LPS 24 h后,TG内Nav1.7的表达显著上调且大鼠摆头阈值降低.SGC活化抑制剂FC可阻断LPS上调的TG内Nav1.7的表达,NF-κB抑制剂PDTC可阻断LPS上调的TG内p-p65、GFAP及Nav1.7的表达.结论:LPS可能通过NF-κB信号通路(p-p65)激活三叉神经节内的卫星胶质细胞,进而上调神经元内Nav1.7的表达,从而调控大鼠颞下颌关节炎性痛.

目的 探究五味子主要成分(Sc)的镇痛作用和分子机制.方法 在醋酸扭体疼痛模型,福尔马林炎性疼痛模型和完全弗氏佐剂疼痛模型上评价Sc的镇痛活性.在重组细胞、脊髓背角(SDH)神经元以及背根神经节(DRG)神经元上,利用膜片钳技术研究Sc的镇痛靶点.结果 在3种小鼠疼痛模型中,Sc的镇痛活性与阳性药吲哚美辛相当.Sc对3种亚型甘氨酸受体和SDH神经元上甘氨酸受体的EC50在2.94～5.77 μmol·L-1.Sc可以显著降低DRG神经元动作电位的发放频率,抑制河豚毒素敏感的钠通道和高电压激活的钙通道.Sc优先作用于Nav1.7通道和Cav2.2通道的失活态,IC50分别为6.97和4.58 μmol·L-1.结论 Sc通过调节甘氨酸受体,Nav1.7通道和Cav2.2通道的活性发挥镇痛作用.

The voltage-gated Na+ channel subtype Nav1.7 is important for pain and itch in rodents and humans.We previously showed that a Navl.7-targeting monoclonal antibody (SVmab) reduces Na+ currents and pain and itch responses in mice.Here,we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab.ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells,mouse DRG neurons,human nerve tissue,and the voltagesensor domain Ⅱ of Navl.7.In contrast,rSVmab showed no or weak binding to Navl.7 in these tests.Patch-clamp recordings showed that SVmab,but not rSVmab,markedly inhibited Na+ currents in Navl.7-expressing HEK293 cells.Notably,electrical field stimulation increased the blocking activity of SVmab and rSVmab in Navl.7-expressing HEK293 cells.SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia.SVmab also bound to human DRG neurons and inhibited their Na+ currents.Finally,potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.

Voltage-gated sodium channels (Navs) play an important role in human pain sensation.However,the expression and role of Nav subtypes in native human sensory neurons are unclear.To address this issue,we obtained human dorsal root ganglion (hDRG) tissues from healthy donors.PCR analysis of seven DRG-expressed Nav subtypes revealed that the hDRG has higher expression of Nav 1.7 (～ 50％ of total Nay expression) and lower expression of Navl.8 (～ 12％),whereas the mouse DRG has higher expression of Nav 1.8 (～ 45％) and lower expression of Navl.7 (～ 18％).To mimic Nay regulation in chronic pain,we treated hDRG neurons in primary cultures with paclitaxel (0.1-1 μmol/L) for 24 h.Paclitaxel increased the Nav1.7 but not Nav1.8 expression and also increased the transient Na+ currents and action potential firing frequency in small-diameter (＜50 μm) hDRG neurons.Thus,the hDRG provides a translational model in which to study "human pain in a dish" and test new pain therapeutics.

The Nav1.7 channel represents a promising target for pain relief.In the recent decades,a number of Nav1.7 channel inhibitors have been developed.According to the effects on channel kinetics,these inhibitors could be divided into two major classes:reducing activation or enhancing inactivation.To date,however,only several inhibitors have moved forward into phase 2 clinical trials and most of them display a less than ideal analgesic efficacy,thus intensifying the controversy regarding if an ideal candidate should preferentially affect the activation or inactivation state.In the present study,we investigated the action mechanisms of a recently clinically confirmed inhibitor CNV1014802 using both electrophysiology and site-directed mutagenesis.We found that CNV1014802 inhibited Nav1.7 channels through stabilizing a nonconductive inactivated state.When the cells expressing Nav1.7 channels were hold at 70 mV or 120 mV,the half maximal inhibitory concentration (IC50) values (with 95％ confidence limits) were 1.77 (1.20-2.33)and 71.66 (46.85-96.48) pmol/L,respectively.This drug caused dramatic hyperpolarizing shift of channel inactivation but did not affect activation.Moreover,CNV1014802 accelerated the onset of inactivation and delayed the recovery from inactivation.Notably,application of CNV1014802 (30 pmol/L) could rescue the Nav1.7 mutations expressed in CHO cells that cause paroxysmal extreme pain disorder (PEPD),thereby restoring the impaired inactivation to those of the wild-type channel.Our study demonstrates that CNV1014802 enhances the inactivation but does not reduce the activation of Nav1.7 channels,suggesting that identifying inhibitors that preferentially affect inactivation is a promising approach for developing drugs targeting Nav1.7.

癫痫(epilepsy,EP)是一种由大脑神经元异常放电所引起的以短暂的大脑功能失常为特征的常见脑部疾病,易反复发作,严重影响患者的健康和生活质量.研究发现,表达在中枢神经系统中电压门控钠通道(voltage-gated sodium channel,VGSC)亚型Nav1.1、Nav1.2、Nav1.3、Nav1.6、Nav1.7在癫痫发病机制中起重要作用,是相关抗癫痫药物(AEDs)的作用靶点.这些通道α亚基编码基因突变可引起不同形式的癫痫发作.本文针对表达在中枢神经系统中的上述5种VGSC亚型基因突变相关癫痫发生和临床治疗作简要综述,为癫痫的发生发展电生理机制和临床治疗研究奠定基础.

目的:观察穿山龙提取物薯蓣皂苷对痛性糖尿病周围神经病变大鼠Nav 1.7通道mRNA表达的影响.方法:SPF级雄性Wistar大鼠80只,随机取14只为正常对照组,其余大鼠腹腔一次性注射链脲佐菌素STZ(53 mg/kg)造模,72 h后测大鼠尾静脉血血糖＞16.7 mmol/L作为观察对象,持续喂养2周,将60只成模大鼠随机分为模型组,薯蓣皂苷高、低剂量组,强的松组,分别于药物治疗后第4、8周,采用实时荧光定量PCR法检测大鼠坐骨神经Nay 1.7mRNA表达情况.结果:与同期模型组比较,各治疗组大鼠坐骨神经Nay 1.7mRNA表达水平下调(P＜0.01),低剂量组较同期高剂量组Nay 1.7mRNA表达上调(P＜0.01),强的松组与同期低剂量组比较,坐骨神经Nay 1.7mRNA表达水平下调(P＜0.05).结论:薯蓣皂苷可以减轻PDPN大鼠坐骨神经的损伤.