Lipopolysaccharide-induced Trigeminal Ganglion Nerve Fiber Damage is Associated with Autophagy Inhibition

Objective This study aimed to determine whether lipopolysaccharide(LPS)induces the loss of corneal nerve fibers in cultured trigeminal ganglion(TG)cells,and the underlying mechanism of LPS-induced TG neurite damage.Methods TG neurons were isolated from C57BL/6 mice,and the cell viability and purity were maintained for up to 7 days.Then,they were treated with LPS(1µg/mL)or the autophagy regulator(autophibib and rapamycin)alone or in combination for 48 h,and the length of neurites in TG cells was examined by the immunofluorescence staining of the neuron-specific proteinβ3-tubulin.Afterwards,the molecular mechanisms by which LPS induces TG neuron damage were explored.Results The immunofluorescence staining revealed that the average length of neurites in TG cells significantly decreased after LPS treatment.Importantly,LPS induced the impairment of autophagic flux in TG cells,which was evidenced by the increase in the accumulation of LC3 and p62 proteins.The pharmacological inhibition of autophagy by autophinib dramatically reduced the length of TG neurites.However,the rapamycin-induced activation of autophagy significantly lessened the effect of LPS on the degeneration of TG neurites.Conclusion LPS-induced autophagy inhibition contributes to the loss of TG neurites.

Changes in P2Y purinoreceptor-mediated intracellular calcium signal pathways results in inositol-1, 4, 5-triphosphate-sensitive calcium stores in rat small trigeminal ganglion neurons

BACKGROUND： Most of the currently available information on purinergic receptors （P2Rs） involved in pain transmission is based on results obtained in dorsal root ganglion or the spinal cord. However, the mechanism of P2Rs in trigeminal neuralgia remains unclear. OBJECTIVE： To investigate changes in the P2R-mediated calcium signaling pathway in nociceptive trigemJnal ganglion neurons. DESIGN, TIME AND SETTING： In vitro experiments were conducted at the Patch-Clamp Laboratory of Comprehensive Experiment Center of Anhui Medical University, China from September 2008 to June 2009. MATERIALS： Thapsigargin, caffeine, suramin, and adenosine 5＇-triphosphate were purchased from Sigma, USA. METHODS： Using Fura-2-based microfluorimetry, intracellular calcium concentration （[Ca^2＋]i） was measured in freshly isolated adult rat small trigeminal ganglion neurons before and after drug application. MAIN OUTCOME MEASURES： Fluorescent intensities were expressed as the ratio F340/F380 to observe [Ca^2＋]i changes. RESULTS： In normal extracellular solution and Ca^2＋-free solution, application of thapsigargin （1 μmol/L）, a sarcoplasmic reticulum Ca^2＋ pump adenosine 5＇-triphosphate inhibitor, as well as caffeine （20 mmol/L）, a ryanodine receptor agonist, triggered [Ca^2＋]i increase in small trigeminal ganglion neurons. A similar response was induced by application of adenosine 5＇-triphosphate （100 μmol/L）. In Ca^2＋-free conditions, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were inhibited in cells pre-treated with thapsigargin （P 〈 0.01）, but not by caffeine （P 〉 0.05）. In normal, extracellular solution, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were partly inhibited in cells pre-treated with thapsigargin （P 〈 0.05）. CONCLUSION： Inositol-1,4, 5-triphosphate （IP3）- and ryanodine-sensitive Ca^2＋ stores exist in rat nociceptive trigeminal ganglion neurons. Two pathways are involved in the purinoreceptor-mediated [Ca^2＋]i rise observed in nociceptive trigeminal ganglion neurons. One pathway involves the metabotropic P2Y receptors, which are associated with the IP3 sensitive Ca^2＋store, and the second pathway is coupled to ionotropic P2X receptors that induce the Ca^2＋ influx.

Effects of Phorbol-12,13-dibuterate on Sodium Currents and Potassium Currents in Rat Trigeminal Ganglion Neurons

The effects of phorbol-12,13-dibuterate （PDBu） on total sodium current （INa-total）, tetrodotoxin-resistant sodium current （INa-TFXr）, 4-AP-sensitive potassium current （IA） and TEA-sensitive potassium current （IK） in trigeminal ganglion （TG） neurons were investigated. Whole-cell patch clamp techniques were used to record ion currents in cultured TG neurons of rats. Results revealed that 0.5μmol/L PDBu reduced the amplitude of INa-total by （38.3±4.5）% （n=6, P〈0.05）, but neither the G-V curve （control： V0.5 =-17.1±4.3 mV, k=7.4±1.3; PDBu： V0.5=-15.9±5.9 mV, k=5.9±1.4; n=6, P〉0.05） nor the inactivation rate constant （control： 3.6±0.9 ms; PDBu： 3.6±0.8 ms; n=6, P〉0.05） was altered. 0.5 μmol/L PDBu could significantly increase the amplitude of INa-TFXr by （37.2± 3.2）% （n=9, P〈0.05） without affecting the G-V curve （control： V0.5=-14.7±6.0 mV, k=6.9± 1.4; PDBu： V0.5=- 11.1±5.3 mV, k=8.1± 1.5; n=5, P〉0.05 ） or the inactivation rate constant （control： 4.6±0.6 ms; PDBu： 4.2±0.5 ms; n=5, P〉0.05）. 0.5 μmol/L PDBu inhibited IK by （15.6±5.0） % （n=16, P〈0.05）, and V0.5 was significantly altered from - 4.7±1.4 mV to -7.9 ±1.8 mV （n=16, P〈0.05）. IA was not significantly affected by PDBu, 0.5μmol/L PDBu decreased IA by only （0.3±3.2）% （n=5, P〉0.05）. It was concluded that PDBu inhibited INa-total ：.but enhanced INa-TFXr, and inhibited IK without affecting IA. These data suggested that the activation of PKC pathway could exert the actions.

TREATMENT OF PRIMARY TRIGEMINAL NEURALGIA WITH ACUPUNCTURE AT THE SPHENOPALATINE GANGLION

Twenty-five cases of Primary trigeminal neuralgia were treated satisfactorily by acupuncture at Xiaguan (St 7) through to the sphenopalatine ganglion, which is an important vegetative ganglion in the head.

Chlorogenic acid alters the voltage-gated potassium channel currents of trigeminal ganglion neurons

Chlorogenic acid（5-caffeoylquinic acid, CGA） is a phenolic compound that is found ubiquitously in plants, fruits and vegetables and is formed via the esterification of caffeic acid and quinic acid. In addition to its notable biological functions against cardiovascular diseases, type-2 diabetes and inflammatory conditions, CGA was recently hypothesized to be an alternative for the treatment of neurological diseases such as Alzheimer＇s disease and neuropathic pain disorders. However, its mechanism of action is unclear.Voltage-gated potassium channel（Kv） is a crucial factor in the electro-physiological processes of sensory neurons. Kv has also been identified as a potential therapeutic target for inflammation and neuropathic pain disorders. In this study, we analysed the effects of CGA on the two main subtypes of Kv in trigeminal ganglion neurons, namely, the IK,Aand IK,Vchannels. Trigeminal ganglion（TRG）neurons were acutely disassociated from the rat TRG, and two different doses of CGA（0.2 and 1 mmol·L21） were applied to the cells.Whole-cell patch-clamp recordings were performed to observe alterations in the activation and inactivation properties of the IK,Aand IK,Vchannels. The results demonstrated that 0.2 mmol·L21CGA decreased the peak current density of IK,A. Both 0.2 mmol·L21and1 mmol·L21CGA also caused a significant reduction in the activation and inactivation thresholds of IK,Aand IK,V. CGA exhibited a strong effect on the activation and inactivation velocities of IK,Aand IK,V. These findings provide novel evidence explaining the biological effects of CGA, especially regarding its neurological effects.

Effect of Interleukin-1β on I_A and I_K Currents in Cultured Murine Trigeminal Ganglion Neurons

To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and after 20 ng/mL IL-1β perfusion. Our results showed that 20 ng/mL IL-1β inhibited IA currents （18.3±10.7）% （n=6, P〈0.05）. IL-1β at 20 ng/mL had no effect on G-V curve of IA but moved the H-infinity curve V0.5 from -36.6±6. 1 mV to-42.4±5.2 mV （n=5, P〈0.01）. However, 20 ng/mL IL-1β had effect on neither the amplitude nor the G-V curve of IK. IL-1β was found to selectively inhibit IA current in TG neurons and the effect may contribute to hyperalgesia under various inflammatory conditions.

Cannabinoids Increase Mechanosensitivity of Trigeminal Ganglion Neurons Innervating the Inner Walls of Rat Anterior Chambers via Activation of TRPA1

Our previous study found that some trigeminal ganglion（TG） nerve endings in the inner walls of rat anterior chambers were mechanosensitive, and transient receptor potential ankyrin 1（TRPA1） was an essential mechanosensitive channel in the membrane. To address the effect of cannabinoids on the mechanosensitive TG nerve endings in the inner walls of anterior chambers of rat eye, we investigated the effect of the（R）-（＋）-WIN55, 212-2 mesylate salt（WIN）, a synthetic cannabinoid on their cell bodies in vitro. Rat TG neurons innervating the inner walls of the anterior chambers were labeled by 1,1＇-dilinoleyl-3,3,3＇,3＇-tetramethylindocarbocyanine, 4-chlorobenzenesulfona（FAST Di I）. Whole cell patch clamp was performed to record the currents induced by drugs and mechanical stimulation. Mechanical stimulation was applied to the neurons by buffer ejection. WIN evoked inward currents via TRPA1 activation in FAST Di I-labeled TG neurons. WIN enhanced mechanosensitive currents via TRPA1 activation in FAST Di I-labeled TG neurons. Our results indicate that cannabinoids can enhance the mechanosensitivity of TG endings in the inner walls of anterior chambers of rat eye via TRPA1 activation.

Inhibitory effects of synthetic cannabinoid WIN55,212-2 on nicotine-activated currents in rat trigeminal ganglion neurons

Cannabinoid and nicotinic acetylcholine receptors are strongly associated with algesia. Previous studies in our laboratory have reported inhibitory effects of synthetic cannabinoid WIN55, 212-2 on nicotine-activated currents （Inic）, but the underlying mechanisms remain poorly understood. The present study used whole-cell patch clamp techniques to investigate the modulatory effects of synthetic cannabinoid WIN55, 212-2 on Inic in cultured rat trigeminal ganglion neurons. The results revealed several major findings： WIN55, 212-2 inhibited Inic in rat trigeminal ganglion neurons. In addition, when WIN55, 212-2 （3 μmol/L） was applied simultaneously with nicotine （100 μmol/L）, the inhibition of WIN55, 212-2 on Inic was reversible, concentration-dependent and voltage-independent This effect was not mediated by CB1, CB2 or VR1 receptors; neither the selective CB1 receptor antagonist AM281, CB2 receptor antagonist AM630 nor VR1 receptor antagonist capsazepine reduced the inhibitory effect of WIN55, 212-2. Further, the inhibition of nicotinic responses by WIN55, 212-2 was not sensitive to the membrane permeable cyclic adenosine monophosphate （cAMP） analog 8-Br-cAMP. The G-protein inhibitor GDP-I3-S （1 mmol/L） did not block the inhibitory effects of WIN55, 212-2 on/n^c, excluding the involvement of G-protein mediation. The results suggested that WIN55, 212-2 inhibits/n^o directly via the neuronal nicotinic acetylcholine receptor, and that this inhibition is non-competitive. WIN55, 212-2 did not act as an open channel blocker of the neuronal nicotinic acetylcholine receptor, and did not affect the desensitization of Into. The results suggest that nicotine receptors may be physically plugged from outside the membrane by drugs containing WIN55, 212-2.

Histochemical Observation of Nitric Oxide Synthase in Trigeminal Ganglion of Rats with Experimental Pulpitis

Summary: In order to understand the roles of nitric oxide (NO) in pulpalgia and pulpitis, the histochemistry of nitric oxide synthase (NOS) in the neurons of trigeminal ganglion in experimental pulpitis rat and human inflammatory dental pulp tissues were histochemically studied by NADPH diaphorase (NADPH D) techniques. Results showed that NADPH D positive neurons were scattered in rat trigeminal ganglions, but the sizes of positive neurons were not changed. None of NOS positive fibers was found in human normal and inflammatory dental pulp tissues. The results suggested that NOS in trigeminal ganglion might play an important role in sensory transmission and regulation of pulpalgia. The absence of NOS positive nerves in human pulp suggested that NO may not be related to inflammatory stimulation and transmission in dental pulp tissues.

Regulatory effects of anandamide on intracellular Ca^(2+) concentration increase in trigeminal ganglion neurons

Activation of cannabinoid receptor type 1 on presynaptic neurons is postulated to suppress neu- ~ ~ ~ 2＋ ~ ~ 2＋ rotransmlsslon by decreasing Ca reflux through high voltage-gated Ca channels. However, recent studies suggest that cannabinoids which activate cannabinoid receptor type 1 can increase neurotransmitter release by enhancing Ca2＋ influx in vitro. The aim of the present study was to investigate the modulation of intracellular Ca2＋ concentration by the cannabinoid receptor type 1 agonist anandamide, and its underlying mechanisms. Using whole cell voltage-damp and calcium imaging in cultured trigeminal ganglion neurons, we found that anandamide directly caused Ca2＋ influx in a dose-dependent manner, which then triggered an increase of intracellular Ca2＋ concentration. The cyclic adenosine and guanosine monophosphate-dependent protein kinase systems, but not the protein kinase C system, were involved in the increased intracellular Ca2＋concentration by anandamide. This result showed that anandamide increased intracellu- lar Ca2＋ concentration and inhibited high voltage-gated Ca2＋ channels through different signal transduction pathways.

Effects of WIN 55,212-2 on I_K Current in Cultured Trigeminal Ganglion Neurons of Rat

Summary: To investigate the effects of WIN 55,212-2 on I K in cultured rat trigeminal ganglion (TG) neurons, whole-cell patch clamp techniques were used to record the I K before and after WIN 55,212-2 perfusion at different concentrations. 30 μmol/L WIN 55,212-2 markedly (35 7 %± 7 3 %, P<0.01, n=8) inhibited I K currents, and the currents were partially recovered after washing. 30 μmol/L WIN 55,212-2 also induced a significant depolarizing shift in conductance-voltage parameters (control: V 0 5=10 43 ± 4.25 mV, k=16 27±3 86; WIN 55,212-2: V 0.5=24.71±3.91 mV, k =16.69±2.75; n = 8, P<0.01 for V 0.5). 0.01 μmol/L WIN 55,212-2 slightly (27.0 %± 7.9 %, P<0.05, n=7) increased I K currents, but had no significant change in conductance–voltage parameters (control: V 0.5=10.74±5.27 mV, k=17.33±2.96; WIN 55,212-2: V 0.5=11.06±2.05 mV, k=19.69±6.60; n=7, P>0.05 for V 0.5 and k). These results suggested that WIN 55,212-2 has dual action, which might be through different receptors.

Inhibition of 5-HT_3 Receptors-activated Currents by Cannabinoids in Rat Trigeminal Ganglion Neurons

This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.

Optimal duration of percutaneous microballoon compression for treatment of trigeminal nerve injury

Percutaneous microballoon compression of the trigeminal ganglion is a brand new operative technique for the treatment of trigeminal neuralgia. However, it is unclear how the procedure mediates pain relief, and there are no standardized criteria, such as compression pressure, com- pression time or balloon shape, for the procedure. In this study, percutaneous microballoon compression was performed on the rabbit trigeminal ganglion at a mean inflation pressure of 1,005 ＋ 150 mmHg for 2 or 5 minutes. At 1, 7 and 14 days after percutaneous microballoon compression, the large-diameter myelinated nerves displayed axonal swelling, rupture and demy- elination under the electron microscope. Fragmentation of myelin and formation of digestion chambers were more evident after 5 minutes of compression. Image analyzer results showed that the diameter of trigeminal ganglion cells remained unaltered after compression. These experi- mental findings indicate that a 2-minute period of compression can suppress pain transduction. Immunohistochemical staining revealed that vascular endothelial growth factor expression in the ganglion cells and axons was significantly increased 7 days after trigeminal ganglion compression, however, the changes were similar after 2-minute compression and 5-minute compression. The upregulated expression of vascular endothelial growth factor in the ganglion cells after percu- taneous microballoon compression can promote the repair of the injured nerve. These findings suggest that long-term compression is ideal for patients with recurrent trigeminal neuralgia.

Nerve coblation for treatment of trigeminal neuralgia: A case report

BACKGROUND Trigeminal neuralgia(TN) is a severe type of neuropathic pain which is often inadequately managed using conventional therapies. In this report, we present the first case of TN treated with gasserian ganglion nerve coblation(NC).CASE SUMMARY A 58-year-old man presented with right facial pain, mostly localized in the right zygomatic zone, alveolar region, and jaws. Similar to acupuncture and shock pain, the pain lasted about five seconds after each attack before resolving unaided. A diagnosis of TN was made, after which treatment with acupuncture therapy and oral carbamazepine was given. However, the pain was not satisfactorily controlled. Subsequently, gasserian ganglion NC of the right trigeminal nerve guided by computed tomography(CT) was performed on the patient. Following this procedure, the right zygomatic, alveolar, submandibular,and cheek pain disappeared completely. The right zygomatic and alveolar areas experienced mild numbness(level II). At 1-, 2-, 3-, and 6-mo follow-ups after surgery, the patient was painless and the numbness score was level I.CONCLUSION CT-guided gasserian ganglion(NC) is an effective treatment for TN and is associated with less or no postoperative numbness or hypoesthesia in comparison with current standard-of-care approaches.

Expression of hNav1.8 sodium channel protein in affected nerves of patients with trigeminal neuralgia

Objective: To explore the pathogenesis of trigeminal neuralgia (TN) and to provide a new target for the drug treatment of TN by studying the expression of tetrodotoxin-resistant hNavl. 8 sodium channel protein in affected nerves of patients with TN. Methods: Twelve affected inferior alveolar nerves were obtained from patients with idiopathic TN, to whom the drug therapy was not effective. As negative control, one normal inferior alveolar nerve was obtained from patients who accepted the combined radical neck dissection with glossectomy and mandibulectomy. One muscle sample was obtained as normal control. One dorsal root ganglion from rat was as positive control. These tissues and prepared hNav1.8 antibody were conducted immunohistochemistry response. Results: hNavl. 8 channel protein was expresses in all the 12 specimens of the affected nerves of patients with TN, but not in the muscle sample and the normal inferior alveolar nerve. Conclusion:The abnormal expression of hNavl. 8 channel protein in the affected nerves of patients with TN may play an impo^nt role in the pathogenesis of TN.

PBL结合图形勾画在进修医师颅底卵圆孔定位教学的应用效果研究

目的探讨基于问题的教学法(problem-based learning,PBL)结合图形勾画在进修医师颅底卵圆孔定位教学的应用效果。方法选择2022年1-12月,在首都医科大学宣武医院疼痛科进修的医生共60名作为研究对象,采用随机数字表法分为试验组(n=30)和对照组(n=30)。在三叉神经半月节球囊压迫术中实施X射线影像定位颅底卵圆孔教学,试验组采用PBL结合图形勾画教学方式,对照组采用传统教学方式。通过理论考试和问卷调查评价教学效果。结果与对照组相比,试验组的理论考试总成绩、影像成绩和操作成绩均高于对照组(85.8±8.5 vs.69.3±13.7,P<0.001;24.7±3.9 vs.21.8±5.2,P=0.020;35.8±3.7 vs.23.7±6.1,P<0.001)。问卷调查检查结果显示,在提高学习兴趣、提升学习能力、解决困惑迷茫、理解重点难点和满意度评分方面,试验组分别优于对照组(96.7±3.1 vs.80.1±6.9,P<0.001;95.2±4.5vs.76.7±6.2,P<0.001;96.0±4.1vs.72.7±7.9,P<0.001;93.8±5.3vs.69.7±7.4,P<0.001;97.2±3.7 vs.75.0±7.3,P<0.001)。结论在X射线影像定位颅底卵圆孔教学的应用中,PBL结合图形勾画取得良好的教学效果,提高学生学习兴趣和学习能力。

原发性三叉神经痛患者经皮穿刺三叉神经半月节球囊压迫术围手术期瞬目反射变化特点及其与患者术后长期疗效的关系

目的探究原发性三叉神经痛(PTN)患者经皮穿刺三叉神经半月节球囊压迫术(PBC)围手术期瞬目反射变化特点及其与患者术后长期疗效的关系。方法收集2020年2—10月于河北省人民医院行PBC的150例PTN患者的临床资料进行回顾性分析。所有患者均于术前1 d、术后1 d及术后第1、3、6、12个月分别进行巴罗神经病学研究所疼痛量表评分(BNI-P)、巴罗神经病学研究所面部麻木评分(BNI-N)评估面部麻木、疼痛情况,并进行瞬目反射检测(涉及传导通路R1、R2及R2′的潜伏期及波幅)。根据患者术后第3年随访结果分为治愈组(120例)和复发组(30例)。比较2组患者临床资料,采用Logistic回归方法分析患者远期预后的影响因素并建立预测模型、评价模型拟合优度。结果患者术后1 d及术后第1、3、6、12个月BNI-P评分均明显低于术前1 d(均P<0.05)。患者行PBC后,R1、R2、R2′潜伏期总体均呈现降低趋势,R1、R2、R2′波幅总体均呈现上升趋势(均P<0.05)。纳入最全面因素的多因素Logistic回归分析结果显示体重指数(比值比=1.254,P=0.028),病程(比值比=1.072,P=0.008),术前BNI-P(比值比=2.189,P=0.040),术前R1、R2、R2′潜伏期(比值比=3.546、4.165、1.314,P=0.012、0.014、0.038)、术前R1、R2、R2′波幅(比值比=0.933、0.920、0.942,P=0.009、0.003、0.002)均为远期预后的影响因素。Hosmer-Lemeshow检验显示模型具有较好的拟合优度(P=0.796)。结论对PTN患者行PBC治疗可取得较好的临床治疗效果,其瞬目反射各项指标均随术后随访时间呈现降低趋势,且与患者面部麻木症状呈现正相关性,患者个体因素及术前BNI-P、瞬目反射指标水平等均对患者术后长期疗效具有重要影响。

数字减影血管造影引导下半月神经节球囊压迫术治疗三叉神经痛的效果分析

目的:探究数字减影血管造影(DSA)引导下半月神经节球囊压迫术治疗三叉神经痛的效果。方法:选取2020年3月—2021年5月百色市人民医院收治的三叉神经痛患者72例为研究对象,随机分成对照组、观察组,各36例。对照组实施小切口开颅显微技术治疗,观察组实施DSA引导下半月神经节球囊压迫术治疗。比较两组患者近远期疗效、疼痛程度和并发症发生情况。结果:两组近期疗效总有效率比较,差异无统计学意义(P>0.05);观察组远期效果总有效率高于对照组,差异无统计学意义(P=0.040)。术前,两组患者视觉模拟评分法(VAS)评分比较,差异无统计学意义(P>0.05);术后6、12、24个月,两组VAS评分均低于术前,观察组低于对照组,差异有统计学意义(P<0.05)。观察组并发症发生率低于对照组,差异有统计学意义(P=0.038)。结论:DSA引导下半月神经节球囊压迫术治疗三叉神经痛的远期疗效显著,可以有效缓解疼痛,降低并发症发生率。

MiR-21-5p通过下调电压门控钾离子通道Kv1.1表达减轻大鼠三叉神经痛

目的:三叉神经痛(trigeminal neuralgia,TN)是一种临床上常见的神经病理性疼痛。电压门控性钾通道(voltage-gated potassium channel,Kv)已被证实参与TN的发生、发展,但具体机制仍不明确。微RNA(microRNA,miR)可通过调节三叉神经节(trigeminal ganglion,TG)上Kv通道的表达及神经元兴奋性,参与神经病理性疼痛。本研究旨在探索TN模型中TG上Kv1.1和miR-21-5p的关系,评估miR-21-5p是否对Kv1.1有调控作用,为TN的治疗提供新的靶点。方法:将48只SD大鼠随机分为6组:1)假手术组(sham组,n=12),大鼠仅在术侧切口缝合,不结扎神经;2)Sham+agomir NC组(n=6),sham大鼠通过脑立体定位注射方法于术侧TG微量注射agomir NC;3)Sham+miR-21-5p agomir组(n=6),sham大鼠通过脑立体定位注射方法于术侧TG微量注射miR-21-5p agomir;4)TN组(n=12),采用铬肠线慢性缩窄性眶下远端神经损伤(chronic constriction injury of the distal infraorbital nerve,dIoN-CCI)法构建TN大鼠模型;5)TN+antagomir NC组(n=6),TN大鼠通过脑立体定位注射方法于术侧TG微量注射antagomir NC;6)TN+miR-21-5p antagomir组(n=6),TN大鼠通过脑立体定位注射方法于术侧TG微量注射miR-21-5p antagomir。检测术后各组大鼠面部机械痛阈变化。采用蛋白质印迹法和实时反转录聚合酶链反应检测术后大鼠术侧TG中Kv1.1和miR-21-5p的表达情况。利用双荧光素酶报告基因确定Kv1.1和miR-21-5p是否存在靶标关系,即miR-21-5p是否可以直接影响KCNA1的3'端非翻译区(3'-untranslated region,3'-UTR)。通过免疫荧光法测定,对脑立体定位注射的效果进行评价,随后分别将miR-21-5p的类似物(agomir)和agomir NC通过脑立体定位仪注射至sham组大鼠TG内,使miR-21-5p过表达;向TN组大鼠TG内分别注射miR-21-5p的抑制剂(antagomir)和antagomir NC,抑制miR-21-5p表达。观察给药前后大鼠行为学变化,检测干预后大鼠TG内miR-21-5p和Kv1.1表达的变化。结果:与基础痛阈值相比,TN组大鼠在术后第5至15天,面部机械痛阈值显著降低(P<0.05),sham组大鼠面部机械痛阈值稳定在正常水平,证明dIoN-CCI模型构建成功。与sham组相比,TN组TG中Kv1.1 mRNA和蛋白质表达均下调(均P<0.05),miR-21-5p的表达上调(P<0.05)。双荧光素酶报告结果显示:与转染mimic NC和野生型KCNA1(KCNA1 WT)组相比,共转染6 nmol/L或20 nmol/L的rno-miR-21-5p mimics的KCNA1 WT组的荧光素酶活性显著降低(P<0.001);与6 nmol/L rno-miR-21-5p mimics共转染组相比,较大剂量(20 nmol/L)的rno-miR-21-5p mimics共转染组的荧光素酶相对活性显著降低(P<0.001)。免疫荧光法结果显示通过脑立体定位可以将药物准确注入TG。TN组抑制miR-21-5p表达后,大鼠面部机械痛阈升高,TG中Kv1.1 mRNA及蛋白质的表达水平升高;sham组过表达miR-21-5p后,大鼠面部机械痛阈降低,TG中Kv1.1 mRNA及蛋白质的表达降低。结论:Kv1.1和miR-21-5p均参与TN的发生、发展,miR-21-5p可以通过结合KCNA13'-UTR来调控Kv1.1的表达,进而影响TN。

卡马西平对三叉神经痛大鼠三叉神经节及血清中BDNF表达变化的影响

目的:三叉神经痛(trigeminal neuralgia,TN)是一种严重的慢性神经病理性疼痛,主要影响三叉神经分布区域,临床治疗效果不佳。TN的治疗方法众多,但目前临床上主要是通过服用卡马西平(carbamazepine,CBZ)来抑制疼痛。脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)和慢性痛密切相关。本研究通过慢性压迫性损伤眶下神经(chronic constriction injury of the infraorbital nerve,ION-CCI)大鼠模型观察CBZ处理对TN大鼠三叉神经节(trigeminal ganglion,TG)和血清中BDNF表达的影响。方法:建立雄性SD大鼠ION-CCI模型,并将其随机分为假手术(sham)组、TN组、TN+低剂量(20 mg/kg)CBZ处理组、TN+中剂量(40 mg/kg)CBZ处理组、TN+高剂量(80 mg/kg)CBZ处理组。在手术前后定时测量各组大鼠的面部机械痛阈(mechanical pain threshold)。使用实时聚合酶链反应技术测定各组大鼠TG中BDNF及酪氨酸激酶受体B(tyrosine kinase receptor B,TrkB)的mRNA含量,免疫荧光技术观察各组大鼠TG中BDNF蛋白质在神经元上的表达情况,蛋白质印迹法检测各组大鼠TG中BDNF、TrkB、细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)及磷酸化的细胞外调节蛋白激酶(phospho-extracellular regulated protein kinases,p-ERK)的蛋白质表达变化,酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测各组大鼠血清中BDNF的表达变化。结果:行为学检测结果表明:手术前,各组大鼠右侧面部感觉区域的机械痛阈差异均无统计学意义(均P>0.05);术后第3天开始,TN组大鼠机械痛阈与sham组相比均明显降低(均P<0.01),TN+80 mg/kg CBZ处理组、TN+40 mg/kg CBZ处理组和TN+20 mg/kg CBZ处理组与TN组相比均升高(均P<0.05)。实时聚合酶链反应和蛋白质印迹法结果显示:TN组大鼠TG中的BDNF、TrkB的mRNA及蛋白质表达量均较sham组升高(均P<0.05),TN+20 mg/kg CBZ处理组、TN+40 mg/kg CBZ处理组、TN+80 mg/kg CBZ处理组均较TN组降低(均P<0.05);与TN组相比,TN+20 mg/kg CBZ处理组、TN+40 mg/kg CBZ处理组、TN+80 mg/kg CBZ处理组大鼠TG中的p-ERK水平均显著降低(均P<0.05)。免疫荧光双标结果表明:TN组TG中的BDNF和神经元特异性核蛋白(neuron-specific nuclear protein,NeuN)主要共表达在神经元上,与sham组比较BDNF和NeuN水平升高(P<0.05),TN+20 mg/kg CBZ处理组、TN+40 mg/kg CBZ处理组、TN+80 mg/kg CBZ处理组与TN组大鼠比较二者表达均降低(均P<0.05)。ELISA检测结果显示:TN组大鼠血清中BDNF的水平较sham组显著升高(P<0.05),TN+20 mg/kg CBZ处理组、TN+40 mg/kg CBZ处理组、TN+80 mg/kg CBZ处理组均较TN组大鼠降低(均P<0.05)。Spearman相关分析显示血清中BDNF水平与机械痛阈呈负相关(r=−0.650,P<0.01)。结论:CBZ处理可以抑制TN大鼠TG中BDNF及其受体TrkB的表达,降低TN大鼠血清中BDNF水平及ERK信号通路磷酸化水平,进而抑制TN。可以考虑将血清中BDNF水平作为诊断TN和评估预后的指标。