米诺环素调控小胶质细胞激活对PC12细胞生长的影响

目的探讨米诺环素抑制小胶质细胞激活对PC12生长和凋亡的影响。方法 BV2细胞分为对照组、LPS组、LPS加米诺环素组;以LPS刺激激活小胶质细胞系BV2细胞,用米诺环素干预BV2细胞的激活;将各组BV2细胞与PC12细胞进行共培养24h;酶联免疫吸附法检测共培养体系细胞上清液TNF-α、IL-1β的含量,MTT法检测PC12细胞生存率。结果 BV2细胞与PC12细胞共培养24h后,LPS组上清液炎症因子TNF-α、IL-1β表达明显升高,PC12细胞存活率下降,米诺环素能抑制以上趋势。结论 MG激活对PC12细胞存在明显损伤效应,米诺环素可保护MG介导的PC12细胞损伤,可能与通过下调炎症表达有关。     

大鼠脑梗死早期星形细胞胶质化及其与神经营养因子的关系

目的 探讨星形南细胞（ＡＳ）在脑梗死早期的变化及与神经营养因子的关系。方法 运用免疫组织化学技术检测Ｍｉｄｋｉｎｅ（ＭＫ）、星形胶质纤维酸性蛋白（ＧＦＡＰ）的动态变化。结果 梗死后１天,梗死边缘开始表达ＧＦＡＦ。梗死后２天,ＧＦＡＰ表达达高峰。ＭＫ于梗死后１天表达,随后其阳性梗死后２￣４天表达逐步增强。结论 脑梗死早期星形胶质细胞增生可能与分泌神经营养因子及损伤后的修复有关。     

A型肉毒毒素作用于神经胶质细胞缓解神经病理性疼痛机制的研究进展

神经病理性疼痛是一个重要的临床问题,常规药物治疗效果不佳。A型肉毒毒素可缓解多种疼痛,其镇痛作用被认为与神经胶质细胞相关。本文概要介绍A型肉毒毒素作用于神经胶质细胞缓解神经病理性疼痛机制的研究进展,进一步探究A型肉毒毒素在神经病理性疼痛治疗上的临床潜力。     

虎杖提取物对神经病理性疼痛模型大鼠的镇痛作用研究

目的：研究虎杖提取物对神经病理性疼痛模型大鼠的镇痛作用,并探讨其作用机制。方法雄性SD大鼠,随机分为对照组和坐骨神经缩狭模型（chronic construction injury, CCI）组。CCI术后14 d,应用Von Frey法测定机械刺激缩足反射阈值（mechanical withdrawal threshold, MWT）,观察口服不同剂量的虎杖提取物对CCI大鼠机械性痛觉超敏的影响。并考察不同剂量虎杖提取物对CCI大鼠脊髓p-ERK、p-P38水平及小胶质细胞活化的影响。结果虎杖提取物可明显升高CCI大鼠术侧的MWT值（P〈0.05）,而对正常大鼠的MWT值没有显著影响（P〉0.05）。同时虎杖提取物可显著抑制CCI模型大鼠脊髓ERK和p38的磷酸化,并显著抑制IBA-1表达增加。结论虎杖提取物对CCI诱导的机械性痛觉超敏具有显著性的抑制作用,且镇痛作用维持时间长于吗啡,其机制可能是通过抑制脊髓水平ERK和p38的磷酸化,及通过抑制小胶质细胞活化而实现。     

星形胶质细胞在坐骨神经分支选择性结扎神经病理性痛中的作用

目的 探讨星形胶质细胞在坐骨神经分支选择性结扎(spared nerve injury,SNI)神经病理性痛中的作用.方法 24只SD大鼠随机分为4组(6只/组):SNI组(建立SNI动物模型同时行鞘内置管术,术后13 d鞘内给予生理盐水);假手术组(处理方式同SNI组,但不损伤坐骨神经及其分支);L-α-aminoadipate(LAA)组(制作SNI动物模型同时行鞘内置管,术后13 d鞘内给予LAA);对照组(不给予任何处理因素).术前2 d及术后14 d检测机械痛和神经病理性痛阈值,术后14 d以Real-time PCR法检测脊髓背角GFAP mRNA变化.结果 术前2 d各组大鼠机械痛域及热痛阈无明显差异(P>0.05).术后14 d假手术组机械痛域、热痛阈及脊髓背角GFAP mRNA较对照组均无明显变化(P>0.05);与对照组相比,SNI组机械痛域及热痛阈明显降低(P<0.05),脊髓背角GFAP mRNA明显增高(P<0.05);与SNI组相比,LAA组机械痛域及热痛阈均明显增高(P<0.05),脊髓背角GFAP mRNA明显降低(P<0.05).结论 LAA特异性抑制脊髓背角星形胶质细胞活性可缓解SNI大鼠神经病理性痛,提示脊髓背角星形胶质细胞活化是SNI大鼠神经病理性的重要机制.     

米诺环素对不完全脊髓损伤大鼠神经功能修复的影响

目的:研究早期应用米诺环素(MINO)对不完全脊髓损伤大鼠神经功能修复的影响。方法:112只大鼠随机分为4组,假手术组(SHAM组)、损伤组(SCI组)、米诺环素低剂量治疗组、米诺环素高剂量治疗组,每组28只,SHAM组仅作椎板切除术,SCI组及米诺环素低剂量组、米诺环素高剂量组用改良Allen’s法制作T10不完全脊髓损伤模型,MINO低剂量组在术后0.5,1 h及1～5 d分别给予腹腔注射米诺环素40 mg·kg-1,MINO高剂量组以同样方法注射米诺环素80 mg·kg-1,SHAM、SCI组在同样的时间点注射等量的生理盐水。每组大鼠随机抽出16只在术前及术后1,3,7,14,21,28 d进行BBB评分,其余大鼠在术后3,7,21 d分别处死取材,行病理形态学观察(HE染色)和胶质纤维酸性蛋白(GFAP)免疫组化测定。结果:术后7～28 d,MINO低剂量组、MINO高剂量组BBB评分明显高于SCI组(P<0.05);HE染色显示在病理学形态上MI-NO低剂量组、MINO高剂量组脊髓损伤较SCI组轻;且GFAP表达明显受到抑制,与SCI组比较有明显差异(P<0.05)。结论:早期应用米诺环素可以促进不完全脊髓损伤大鼠神经功能的修复。     

抑制小胶质细胞激活对骨癌痛小鼠疼痛维持的影响

目的研究鞘内注射小胶质细胞特异性抑制剂米诺环素(minocycline,MC)抑制脊髓小胶质细胞的激活对骨癌痛维持的影响。方法采用小鼠跟骨癌痛模型,♂C3H/He小鼠42只,随机分为3组(n=14),sarcoma+PBS(phosphatebuffered saline)组和sarcoma+MC组行小鼠跟骨癌痛模型制作,跟骨内注射肿瘤细胞;sham+PBS组行假手术,跟骨内注射PBS。造模后11天(post-implantation day11,PID11),每组随机取10只小鼠,sham+PBS组和sarcoma+PBS组单次鞘内注射MC溶媒(PBS 5μl),sarcoma+MC组单次鞘内注射MC(1 nmol,5μl)。各组分别在鞘内注射前、注射后0.5、1、2、4、8、24 h测定机械性痛觉超敏、冷痛觉过敏。各组剩余4只小鼠在PID12鞘内注射后1 h行非伤害性触摸右侧足底90min,分析脊髓背角c-fos蛋白的表达。结果骨癌痛导致小鼠机械性痛阈和冷痛阈降低,脊髓背角c-fos蛋白的表达上调;单次鞘内注射MC能暂时提高小鼠疼痛阈值,并抑制脊髓背角c-fos蛋白的表达。结论小胶质细胞的激活对骨癌痛的维持具有重要作用。     

阿米替林对神经病理性疼痛大鼠脊髓GLAST的影响

目的观察阿米替林对SNI大鼠脊髓谷氨酸-天冬氨酸转运体(GLAST)表达影响。方法60只♂SD大鼠,分为空白对照组(A)、SNI模型组(B)、阿米替林(AMI)注射对照组(C)、SNI模型+AMI治疗组(D),经腹腔分别给予0.2ml生理盐水(A、B)、10mg.kg-1AMI(C和D),每日两次。术后1、3、5d取各组大鼠L3~L6脊髓,分别检测GLAST的蛋白和mRNA表达改变,同时观察机械缩足反射阈值(mechanical withdrawal threshold,MWT)改变。结果与对照组相比,B组大鼠MWT随时间明显下降,GLAST蛋白和mRNA表达先增加再降低,C组大鼠MWT无改变,但是GLAST蛋白和mRNA表达随时间逐渐增加,D组大鼠MWT给药后3d停止下降,GLAST蛋白和mRNA表达明显增高,但不随时间变化。结论阿米替林可以增加GLAST蛋白表达,可能是治疗神经病理性疼痛的机制之一。     

移植重编程星形胶质细胞对大鼠损伤脊髓恢复的影响

目的探讨移植经直接重编程后的星形胶质细胞对大鼠脊髓损伤功能恢复的影响。方法建立SD大鼠脊髓损伤模型48只,随机均分为四组,分别为移植转染了含有神经原素2(Ngn2)的星形胶质细胞组(A组)、移植转染了绿色荧光蛋白基因的星形胶质细胞组(B组)、移植星形胶质细胞组(C组)和移植PBS组(D组)。移植后4周,免疫荧光染色观察脊髓组织的神经元特异性核蛋白(NeuN)和微管相关蛋白2(MAP2)的表达;利用Basso Beattie and Bresnahan(BBB)评分系统对移植后的大鼠进行连续8周的BBB评分,观察其运动功能的恢复情况。结果连续观察8周后,A组的BBB评分高于其他三组(P<0.05)。A组的NeuN和MAP2表达均高于B组(P<0.05)。结论在大鼠脊髓损伤模型中,移植经直接重编程处理过的星形胶质细胞能提高受损脊髓组织的神经元数量,有助于损伤脊髓的运动功能恢复。     

Post-injury repeated administrations of minocycline improve the antinociceptive effect of morphine in chronic constriction injury model of neuropathic pain in rat

It is confirmed that pharmacological attenuation of glial cells can alleviate neuropathic pain by lowering proinflammatory cytokine expression. The present study tries to confirm that post-injury administration of glia inhibitor, minocycline, can attenuate the neuropathic pain symptoms and improves the efficacy of morphine anti-nociception in chronic constriction injury (CCI). Male Wistar rats (230-270 g) underwent surgery for induction CCI model of neuropathy. For assessment of the thermal hyperalgesia and mechanical allodynia after CCI induction, morphine (2.5, 5, 7.5, 10 and 15 mg/kg; s.c.) and saline were administered on post-operative days (PODs) 0, 6 and 14. Hargreaves and Von-Frey tests were performed before and 30 min after morphine administration, respectively. The results showed significant decrease in antinociceptive effect of morphine on POD 6 compared to POD 0 only at the dose of 5 mg/kg. On the other hand, on POD 14 the antinociceptive effect of morphine (5, 7.5, 10 and 15 mg/kg) significantly decreased in comparison with POD 0. In another set of experiments, animals received minocycline (10, 20 and 40 mg/kg; i.p.) for eight days from POD 6 to 13 and then the antinociceptive effect of single dose of morphine 5 mg/kg was tested on POD 14. Behavioral tests showed that minocycline (40 mg/kg) could effectively attenuate the thermal hyperalgesia and mechanical allodynia on POD 13. Moreover, minocycline (40, 20 mg/kg) improved the anti-hyperalgesic, and minocycline (40 mg/kg) improved the anti-allodynic effects of morphine 5 mg/kg on POD 14. It seems that the reduction of antinociceptive effect of morphine after CCI may be mediated through glia activation. Modulation of glial activity by minocycline can attenuate CCI-induced neuropathic pain. It is also shown that repeated post-injury administration of minocycline improves the antinociceptive effect of morphine in neuropathic pain.     

恩再适治疗神经病理性疼痛的临床应用

目的 评价恩再适治疗神经病理性疼痛的疗效.方法 选择25例神经病理性疼痛的患者,每个患者给予恩再适9ml加入0.9%生理盐水250ml中静脉滴注,1次/日,连续14天,在用药前,用药后第1天、第7天和第14天用VAS10分法检测神经病理性疼痛的缓解程度.结果 用药后第1天,疼痛改善不明显;第7天开始,恩再适明显缓解神经病理性疼痛;本次观察显效率68.85%,总有效率92.5%.有1例患者出现皮疹,停药后皮疹逐渐消失.结论 恩再适治疗神经病理性疼痛有效率较高,安全性较好.     

鞘内应用布托啡诺对神经痛大鼠脊髓NMDAR1、MoR mRNA表达的影响

目的：观察鞘内注射布托啡诺对神经源性疼痛大鼠脊髓NMDAR1、MOR mRNA表达的影响,进而探讨布托啡诺治疗神经源性疼痛的可能机制。方法：健康雄性SD大鼠24只,体重（250±20）g,随机分为3组（n=8）,对照组（B组）、生理盐水组（C组）和布托啡诺组（T组）。B组不给予任何干预处理;C组和T组进行鞘内置管并建立大鼠神经病理性疼痛模型（CCI）,C组鞘内每天给予10μl生理盐水,T组鞘内每天输注布托啡诺12μg/10μl（生理盐水稀释）。持续7d后,断头处死大鼠,取出脊髓标本,RT—PCR测定NMDAR1和MORmRNA的表达水平。结果：NMDAR1 mRNA表达,C组与B组相比,NMDAR1 mRNA表达水平显著升高,P〈0．01,T组与C组比较表达水平降低．P〈0．05。MOR mRNA表达,B组、C组、T组各组间相比,差异无统计学意义。结论：鞘内注射布托啡诺可降低CCI模型引起的大鼠脊髓NMDAR1 mRNA表达水平上调,对MOR mRNA表达水平无影响;CCI模型后12d内MOR mRNA的表达水平恢复萨常．     

Recent trends in neuropathic pain patents

Introduction: Neuropathic pain (NP) is one of the most important health problems faced nowadays. NP is a chronic disease that cannot be treated like other pain conditions because it is developed from a nerve injury that evolves into a permanent dysfunction of the central and/or peripheral nervous system. Therefore, it involves the participation of several systems and should be viewed as a multi-factorial disease that needs a whole new pharmacological strategy in order to achieve the desired pain relief.

Areas covered: The Espacenet site was used as the main source in order to perform the patent research for NP treatment. This review covers the patents with relevant approaches for NP treatment from 2014 until today.

Expert opinion: Our patent research has shown that there is not a consensus approach to treat NP in any of its forms. In our opinion, the approach regarding NP needs to be like cancer’s approach. As there are different types of cancer and different ways to treat them, the same needs to be done for NP. Currently, there are several promising targets, which corroborates that this is a wide-open research area. For these reasons, neuropathic pain is a therapeutic field full of potential for innovation.     

Menin regulates spinal glutamate-GABA balance through GAD65 contributing to neuropathic pain

BackgroundOur previous work found that tumor suppressor menin potentiates spinal synaptic plasticity in the context of peripheral nerve injury-induced neuropathic hypersensitivity, but the underlying molecular mechanisms are not clear. We hereby assessed the role of menin in regulating the spinal balance between glutamate and GABA and its contribution to the pathological condition of nerve injury-induced hypersensitivity.MethodsIn spared nerve injury induced C57BL/6 mice, mechanical withdrawal threshold was measured with von Frey filaments after intrathecal administration of small interfering RNA (siRNA) of MEN1 or/and subcutaneous histone deacetylase (HDAC) inhibitors to control the level of glutamic acid decarboxylase 65 (GAD65). Immunoblotting and high-performance liquid chromatography were used to detect the level of protein expression and spinal glutamate and GABA, respectively.ResultsGenetic knockdown of spinal menin alleviated nerve injury evoked mechanical hypersensitivity, which was strongly associated with the alteration of the spinal level of GAD65 that resulted in an imbalance of glutamate/GABA ratio from the baseline ratio of 5.8 ± 0.9 (×10⁻⁴) to the peak value of 58.6 ± 11.8 (×10⁻⁴) at the day 14 after SNI (p < 0.001), which was reversed by MEN1 siRNA to 14.7 ± 2.1 (×10⁻⁴) at the day 14 after nerve injury (p < 0.01). In further, selective inhibitors of HDACs considerably reversed the ratio of spinal glutamate and GABA, and also alleviated the mechanical withdrawal threshold markedly.ConclusionOur findings provide mechanistic insight into the contribution of the upregulated spinal menin to peripheral nerve injury induced neuropathic hypersensitivity by regulating glutamate-GABA balance through deactivating GAD65.     

Novel sodium channel antagonists in the treatment of neuropathic pain

Introduction: Effective and safe drugs for the treatment of neuropathic pain are still an unmet clinical need. Neuropathic pain, caused by a lesion or disease that affects the somatosensory system, is a debilitating and hampering condition that has a great economic cost and, above all, a tremendous impact on the quality of life. Sodium channels are one of the major players in generating and propagating action potentials. They represent an appealing target for researchers involved in the development of new and safer drugs useful in the treatment of neuropathic pain. The actual goal for researchers is to target sodium channels selectively to stop the abnormal signaling that characterizes neuropathic pain while leaving normal somatosensory functions intact.

Areas covered: This review covers the most recent publications regarding sodium channel blockers and their development as new treatments for neuropathic pain. The main areas discussed are the natural sources of new blockers, such as venom extracts and the recent efforts from many pharmaceutical companies in the field.

Expert opinion: There have been serious efforts by both the pharmaceutical industry and academia to develop new and safer therapeutic options for neuropathic pain. A number of different strategies have been undertaken; the main efforts directed towards the identification of selective blockers starting from both natural products or screening chemical libraries. At this time, researchers have identified and characterized selective compounds against Na_V1.7 or Na_V1.8 voltage-gated sodium channels but only time will tell if they reach the market.     

Lithium attenuates pain-related behavior in a rat model of neuropathic pain: possible involvement of opioid system

Lithium is a major drug for bipolar disorder and mania. Recently, many studies have shown the neuroprotective effect of lithium in different models of neurodegenerative diseases. The present study was carried out to examine the effect of lithium in a rat model of neuropathic pain induced by partial sciatic nerve ligation and the possible role of opioid system in this effect. To do so, animals received acute injection of saline, lithium (5, 10 and 15 mg/kg,) and naloxone (1 mg/kg) or the combination of naloxone (1 mg/kg) with lithium (10 mg/kg) intraperitoneally on the testing days. Thermal hyperalgesia, mechanical and cold allodynia were measured on the days 3, 5, 7, 10 and 14 after surgery. Lithium decreased thermal hyperalgesia scores with dose of 5, 10 and 15 mg/kg and cold and mechanical allodynia scores with dose of 10 and 15 mg/kg, significantly. The opioid antagonist naloxone prevented the effect of lithium on thermal hyperalgesia and mechanical allodynia while it did not show any effect on the acetone-induced cold allodynia. Our results suggest that lithium can be considered as a therapeutic potential for the treatment of some aspects of neuropathic pain and that the opioid system may be involved in the lithium-induced attenuation of thermal hyperalgesia and mechanical allodynia.     

Potentiation of morphine antiallodynic efficacy by ACPT-III, a Group III metabotropic glutamate receptor agonist, in rat spinal nerve ligation-induced neuropathic pain

Despite the importance of spinal metabotropic glutamate receptors (mGluRs) and opioid receptors in nociceptive processing, the roles of these receptors in the modulation of neuropathic pain at the spinal level have not been thoroughly investigated. The purpose of this study was to investigate the effects of spinal mGluR agents and opioids (morphine) on neuropathic pain. Male Sprague-Dawley rats underwent L5 and L6 spinal nerve ligation to induce neuropathic pain and intrathecal catheterization for drug administration. A paw-withdrawal threshold to mechanical stimulus was measured using the “up and down” method. When administered intrathecally, neither Group I mGluR antagonists nor Group II or III agonists modified the withdrawal threshold after spinal nerve ligation. Intrathecal administration of morphine dose-dependently increased the withdrawal threshold. Whereas ACPT-III, a Group III mGluR agonist, enhanced the antiallodynic action of morphine, other mGluR agents did not. Collectively, mGluRs may not directly modulate the processing of spinal nerve ligation-induced neuropathic pain at the spinal level. However, Group III mGluR agonists in the spinal cord may indirectly contribute to the potentiation of morphine antiallodynia, indicating that these agonists might be used as adjuvants for spinal morphine.