靶向TRPV1通道的镇痛剂研究进展

瞬时受体电位香草酸亚型1(Transient Receptor Potential Vanilloid 1,TRPV1)通道广泛分布于感觉神经末梢、中枢神经系统和其他组织,是响应热痛和化学刺激的离子通道蛋白。近年来,TRPV1受体作为治疗各种疼痛相关疾病的潜在方法引起了人们的广泛关注。本文探讨疼痛治疗中的TRPV1激动剂和拮抗剂,根据其结构特征进行分类和阐述,并对配体的结合模式、构效关系、优势和局限性进行讨论,为今后开发更安全有效的TRPV1镇痛剂提供参考。

N-乙酰半胱氨酸对支气管哮喘大鼠CXCL8-CXCR1/2及TRPV1神经元敏感性的影响

目的探究N-乙酰半胱氨酸对支气管哮喘大鼠CXC趋化因子配体(CXCL)8-CXC趋化因子受体(CXCR)1/2及瞬时受体电位通道蛋白(TRP)V1神经元敏感性的影响。方法选取80只SPF级SD雄性大鼠,随机分为正常(NO)组、模型(MO)组、N-乙酰半胱氨酸(NAC)组、急支糖浆(ES)组,每组20只,对MO组、NAC组、ES组进行支气管哮喘建模,建模成功后,NAC组、ES组每天分别于腹腔内注射2 ml N-乙酰半胱氨酸注射液、急支糖浆灌胃10 g/kg剂量,NO组、MO组同期灌胃同体积生理盐水,通过苏木素-伊红(HE)染色法检测肺组织病理形态、酶联免疫吸附试验(ELISA)、实时荧光定量聚合酶链反应(RT-PCR)、Western印迹检测血清及肺组织中CXCL8、CXCR1、CXCR2、TRPV1含量、mRNA及蛋白表达,并分析N-乙酰半胱氨酸对支气管哮喘大鼠CXCL8-CXCR1/2及TRPV1神经元敏感性。结果与NO组相比,MO组咳嗽次数明显增加(P<0.05),而NAC组、ES组与MO组相比,其咳嗽次数明显降低(P<0.05),且NAC组比ES组降低明显(P<0.05);与NO组相比,MO组细支气管管腔、肺泡腔内可见渗出液、脱落的上皮细胞等,远端肺泡可见局部肺不张及周围肺大泡,且肺间质明显增厚,炎性细胞浸润明显,而与MO组比较,ES组、NAC组症状明显减少,部分肺间质的组织结构趋向正常,部分肺泡轻度扩张,且NAC组比ES组明显降低(P<0.05);与NO组对比,MO组CXCL8、CXCR1、CXCR2、TRPV1含量、mRNA及蛋白表达均明显升高(P<0.05),NAC组、ES组与MO组相比均显著降低(P<0.05),且NAC组比ES组明显降低(P<0.05)。结论N-乙酰半胱氨酸可以显著降低咳嗽次数,减少支气管哮喘症状,可使CXCL8-CXCR1/2及TRPV1神经元敏感性显著降低。

Blockade of transient receptor potential cation channel subfamily V member 1 promotes regeneration after sciatic nerve injury

The transient receptor potential cation channel subfamily V member 1（TRPV1） provides the sensation of pain（nociception）. However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whether activation of TRPV1 affects neural regeneration. In the present study, we established rat models of unilateral sciatic nerve crush injury, with or without pretreatment with AMG517（300 mg/kg）, a TRPV1 antagonist, injected subcutaneously into the ipsilateral paw 60 minutes before injury. At 1 and 2 weeks after injury, we performed immunofluorescence staining of the sciatic nerve at the center of injury, at 0.3 cm proximal and distal to the injury site, and in the dorsal root ganglia. Our results showed that Wallerian degeneration occurred distal to the injury site, and neurite outgrowth and Schwann cell regeneration occurred proximal to the injury. The number of regenerating myelinated and unmyelinated nerve clusters was greater in the AMG517-pretreated rats than in the vehicle-treated group, most notably 2 weeks after injury. TRPV1 expression in the injured sciatic nerve and ipsilateral dorsal root ganglia was markedly greater than on the contralateral side. Pretreatment with AMG517 blocked this effect. These data indicate that TRPV1 is activated or overexpressed after sciatic nerve crush injury, and that blockade of TRPV1 may accelerate regeneration of the injured sciatic nerve.

Electroacupuncture at ST25 inhibits jejunal motility:Role ofsympathetic pathways and TRPV1

AIM: To investigate whether electroacupuncture(EA) at ST25 affects jejunal motility in vivo and if so, whether a sympathetic pathway is involved.METHODS: Jejunal motility was assessed using a manometric balloon placed in the jejunum approximately about 3-5 cm away from the suspensory ligament of the duodenum in anesthetized animals. The effects of EA at ST25 were measured in male Sprague-Dawley rats, some of which were treated with propranolol or clenbuterol(EA intensities: 1, 3, 5, 7, and 9 m A), and in male transient receptor potential vanilloid-1(TRPV1)(capsaicin receptor) knockout mice(EA intensities: 1, 2, and 4 m A).RESULTS: Anesthetized rats exhibited three types of fasting jejunal motor patterns(types A, B, and C), and only type C rats responded to EA stimulation. In type C rats, EA at ST25 significantly suppressed the motor activity of the jejunum in an intensity-dependent manner. The inhibitory effect of EA was weakened by propranolol(β adrenoceptor antagonist) and disappeared with clenbuterol(β adrenoceptor agonist) induced inhibition of motility, suggesting that the effect of EA on motility is mediated via a sympathetic pathway. Compared with wild-type mice, EA at ST25 was less effective in TRPV1 knockout mice, suggesting that this multi-modal sensor channel participates in the mechanism. CONCLUSION: EA at ST25 was found to inhibit jejunal motility in an intensity-dependent manner, via a mechanism in which sympathetic nerves and TRPV1 receptors play an important role.

Qingfei oral liquid downregulates TRPV1 expression to reduce airway inflammation and mucus hypersecretion injury caused by respiratory syncytial virus infection and asthma in mice

Objective:Qingfei oral liquid(QF),an experimental Chinese medicine prescription developed from the ancient priscription of traditional Chinese medicines Ma Xin Shi Gan decoction and Tingli Dazao Xie Fei decoction,has been effectively used since decades to treat patients with viral pneumonia and asthma.In our previous study,we had demonstrated that QF can significantly reduce airway hyperresponsiveness,hyperemia,lung tissue edema,inflammatory lung tissue infiltration in mice,airway mucus secretion,and peripheral airway collagen hyperplasia;however,its mechanism of action is unknown.Methods:Fifty 6–8-week-old male BALB/c mice were equally and randomly divided into five groups:the control,ovalbumin(OVA),OVA+respiratory syncytial virus(RSV),QF,and dexamethasone(Dxms)groups.The QF group was administered QF at 1.17 g·kg−1·d−1,the Dxms group received dexamethasone injections at 0.2 mg·kg−1·d−1,and the remaining groups were administered PBS.Inflammation in the lung tissue was assessed by hematoxylin and eosin(HE),periodic acid–Schiff(PAS),and Van Gieson staining.ELISA was used to evaluate the IL-13,IL-25,and IL-33 in the mice.Western blotting was used to examine changes in the proteins levels of transient receptor potential vanilloid-1(TRPV1)and mucin 5AC(MUC5AC)in the lung tissues of mice.Results:Histopathological evaluation revealed that the OVA and OVA+RSV groups exhibited lung tissue edema and inflammatory lung tissue infiltration in the HE staining and airway secretions in the PAS staining;collagen hyperplasia around the airway was increased in these two groups compared with the control group.The QF group exhibited significantly reduced lung tissue edema,inflammatory lung tissue infiltration,airway secretions,and collagen hyperplasia around the airway compared with the OVA+RSV group.We analyzed the serum levels of IL-13,IL-25,and IL-33 in the mice and found that these levels were higher in the OVA and OVA+RSV groups than in the control group(P<0.05 in the OVA group,P<0.01 in the OVA+RSV group).The QF group exhibited significantly decreased serum levels of IL-13,IL-25,and IL-33 compared with the OVA+RSV group(all P<0.05).The Dxms group also exhibited significant decreases in the serum levels of IL-13 and IL-33(all P<0.05)but no significant decrease in the serum levels of IL-25 compared with the RSV+OVA group.Finally,we examined the protein levels of TRPV1 and MUC5AC in the lung tissues of mice using Western blotting.After identifying RSV infection in the mice with asthma,the protein levels of TRPV1 and MUC5AC in the lung tissues of mice were significantly higher than those in the control group(P<0.05,P<0.01).We found that compared with RSV+OVA,QF can significantly downregulate the protein level of TRPV1;further,the protein level of MUC5AC was also significantly reduced(all P<0.001).Conclusion:QF can inhibit RSV replication and reduce airway inflammation and mucus hypersecretion injury caused by RSV infection and asthma,and its mechanism of action may be associated with the downregulation of TRPV1 expression and a decrease in airway mucus hypersecretion injury.

Role of transient receptor potential vanilloid-1 in behavioral thermoregulation of the Mongolian gerbil Meriones unguiculatus

Ambient temperature considerably affects the physiology and behavior of mammals.Thermosensory and thermoregulatory abilities play an important role in the response to changing ambient temperature in endotherms.However,the molecular mechanisms of behavioral thermoregulation remain poorly understood.Transient receptor potential vanilloid-1(TRPV1)is activated by changes in ambient temperature and is involved in acute thermoregulation.Here,we aimed to determine whether TRPV1 is involved in behavioral thermoregulation in wild rodents by conducting 2 experiments.In the first,42 adult Mongolian gerbils(Meriones unguiculatus;14 per treatment)were randomly assigned to 3 housing temperatures(4,23,and 36℃for 4 weeks.In the second,20 gerbils(10 per treatment)were randomly injected with capsaicin(TRPV1 agonist)or AMG517(TRPV1 antagonist).The results showed a significant decrease in food intake and non-shivering thermogenesis in the gerbils housed at 36℃.Additionally,there was a significant increase in the preference of gerbils housed at 4℃ to low temperatures.The expression of TRPV1 protein in the brown adipose tissue(BAT)and liver was significantly positively correlated with that of protein kinase A(PKA).The expression of TRPV1 and PKA proteins in the BAT was positively correlated with the temperature preference of the gerbils.The gerbils injected with capsaicin preferred significantly lower temperatures than the control group gerbils.These findings suggest that TRPV1 and PKA are involved in behavioral thermoregulation in Mongolian gerbils.

瞬时受体电位香草酸亚家族1介导针刺治疗病理性疼痛的作用

Acupuncture,a traditional oriental intervention for chronic pain,has been gaining worldwide popularity.Transient receptor potential vanilloid subfamily 1(TRPV1)is a key factor mediating pain production and sensitization.According to multiple studies,TRPV1 is involved the acupuncture-induced relief of pathological pain.Herein,we systematically screened the experimental reports on TRPV1 involvement in acupuncture analgesia,and reviewed the role of TRPV1 in acupuncture in inhibiting different pathological pain and unresolved problems,including inflammatory pain,neuropathic pain,visceral pain,fibromyalgia and cancer pain.At localized acupoints,TRPV1 was involved in the initiation of acupuncture signals.Acupuncture could inhibit the development of pathological pain as well as the transmission of pain signals by suppressing TRPV1 expression and opening activity from the peripheral dorsal root ganglia to the central spinal cord.Furthermore,acupuncture can not only inhibit the expression of TRPV1,but also promote the expression of TRPV1 in the brain to alleviate pain sensation and depression-like behavior.Moreover,the mechanism by which acupuncture regulates TRPV1 may involve neuro-immune crosstalk.In conclusion,the regulation of TRPV1 expression and function may be one of the primary mechanisms by which acupuncture relieves pathological pain,laying the groundwork for future basic research on acupuncture's pain-relieving effects.

艾灸“大肠俞”对大鼠内脏痛敏及骨髓细胞瞬时感受器电位香草酸受体亚型1表达的影响

目的:运用大鼠新生期结直肠扩张(CRD)形成成年内脏痛敏模型,探讨内脏痛敏及艾灸疗效与骨髓细胞瞬时感受器电位香草酸受体亚型(TRPV)1表达之间的关系。方法:新生SD雄性大鼠自出生8d后进行CRD刺激建立内脏痛敏模型。8周后对模型组和对照组进行"大肠俞"模拟热敏灸,灸前后CRD刺激,记录腹部撤回反射(AWR)评分及测定痛阈值,结束后90min内取各组大鼠骨髓细胞运用RT-PCR测TRPV 1mRNA表达。结果:①模型组AWR评分明显高于对照组(P<0.01),痛阈明显低于对照组(P<0.01)。②模型组艾灸后的AWR评分明显低于艾灸前(P<0.05,P<0.01),痛阈明显高于艾灸前(P<0.01)。对照组艾灸后40、60、80mmHg的AWR评分明显低于艾灸前(P<0.01),痛阈明显高于艾灸前(P<0.05)。③对照组TRPV 1mRNA相对表达量较低(0.655±0.400),艾灸对照组TRPV 1mRNA相对表达量降低(0.551±0.257,P>0.05),艾灸模型组TRPV 1mRNA相对表达量(2.423±2.730)较对照组、艾灸对照组略高(P>0.05),模型组TRPV 1mRNA相对表达量(6.550±2.308)明显高于对照组、艾灸对照组、艾灸模型组(P<0.01)。结论:新生期CRD可形成内脏痛敏,骨髓细胞TRPV 1mRNA表达明显增加。艾灸"大肠俞"明显减轻内脏痛敏,可减少骨髓细胞TRPV 1mRNA表达。

艾灸对瞬时受体电位香草酸亚型1基因敲除小鼠局部皮肤中肿瘤坏死因子-α表达的影响

目的:以肿瘤坏死因子-α(TNF-α)为指标,观察瞬时受体电位香草酸亚型1(TRPV 1)是否参与了艾灸启动穴位局部免疫炎性反应的过程。方法:将C 57BL/6J和TRPV1^(-/-)小鼠分别随机分为空白组、30min艾灸组、72h艾灸组,每组5只。各艾灸组均艾灸"足三里",艾灸温度控制在(46±1)℃,通过HE染色观察局部皮肤的形态结构变化,免疫荧光法观察局部皮肤TNF-α阳性细胞的数量。结果:与C 57BL/6J空白组小鼠比较,30min艾灸组表皮TNF-α阳性细胞数明显增多(P<0.05),30min艾灸组、72h艾灸组真皮TNF-α阳性细胞数明显增多(P<0.01);30 min艾灸组真皮TNF-α阳性细胞数明显多于72h艾灸组(P<0.01)。与TRPV1^(-/-)空白组小鼠比较,30min艾灸组表皮TNF-α阳性细胞数明显增多(P<0.01),30min艾灸组、72h艾灸组真皮TNF-α阳性细胞数明显增高(P<0.01);30 min艾灸组小鼠表皮、真皮TNF-α阳性细胞数明显高于72h艾灸组(P<0.01)。结论:艾灸启动穴位局部免疫炎性反应可能不依赖于TRPV 1通道。

银耳多糖超声波提取工艺优化及抗BV2细胞炎症的作用研究

以银耳为原料,采用超声波辅助热水浸提法提取银耳多糖,以多糖提取率为指标,以超声波功率、提取料液比、提取温度和提取时间为影响因素,设计单因素试验,并通过正交试验得到较佳提取工艺。通过用TRPV1(Transient Receptor Potential Vanilloid1)试剂盒检测了小胶质细胞TRPV1的释放水平,与脂多糖(Lipopolysaccharide,LPS)对照组相比,不同质量浓度的银耳多糖组(62.5,250,1000μg/mL)均能不同程度地抑制TRPV1的释放量。说明了银耳多糖对于BV2小胶质细胞炎症具有良好的抑制作用。

电针“印堂”“天枢”穴对肠易激综合征大鼠行为学及结肠辣椒素受体的影响

目的:观察电针"印堂""天枢"穴对肠易激综合征(IBS)大鼠行为学及结肠辣椒素受体(TRPV 1)表达的影响,探讨电针不同主治功能的穴位对身心疾病不同症状疗效的差异及其相关机制。方法:Wistar新生大鼠32只随机分为空白对照组、模型对照组、印堂组、天枢组。除空白对照组外,均采用新生期母子分离加醋酸灌肠并联合结直肠扩张刺激法制备IBS大鼠模型。大鼠9周龄时印堂和天枢组分别给予电针干预,每次20min,隔日1次,共5次。采用腹部回撤反射对大鼠进行内脏敏感性评估,观察第1次收缩波潜伏期及90s内收缩波个数;采用旷场实验评估大鼠情绪心理行为,观察其水平及垂直运动次数;采用免疫组织化学法检测结肠组织TRPV 1的表达。结果:与空白对照组比较,模型对照组第1次收缩波潜伏期明显缩短(P<0.01),收缩波个数明显增多(P<0.01),水平运动次数以及垂直运动次数均明显减少(P<0.01),结肠内TRPV 1免疫反应物阳性表达水平增强(P<0.05)。与模型对照组比较,天枢组及印堂组第1次收缩波潜伏期延长及90s内收缩波个数明显减少(P<0.01,P<0.05),天枢组垂直运动次数增多(P<0.05),印堂组的垂直运动次数及水平运动次数均明显增多(P<0.01),天枢组及印堂组结肠TRPV 1免疫反应物阳性表达显著下降(P<0.01,P<0.05)。与印堂组比较,天枢组TRPV 1免疫反应物阳性表达显著下降(P<0.01)。结论:电针"印堂""天枢"穴均可明显缓解IBS大鼠的腹痛并改善精神情绪的异常,电针"印堂"穴能更好地缓解模型大鼠抑郁样情绪行为,而电针"天枢"穴治疗腹痛效果较佳,二者对结肠内TRPV 1免疫反应物阳性表达的影响存在明显差异。