Effects of carbamazepine on BDNF expression in trigeminal ganglia and serum in rats with trigeminal neuralgia / 中南大学学报(医学版)

Objective:Trigeminal neuralgia(TN)is a severe chronic neuropathic pain that mainly affects the distribution area of the trigeminal nerve with limited treating efficacy.There are numerous treatments for TN,but currently the main clinical approach is to suppress pain by carbamazepine(CBZ).Brain-derived neurotrophic factor(BDNF)is closely related to chronic pain.This study aims to determine the effects of CBZ treatment on BDNF expression in both the trigeminal ganglion(TG)and serum of TN via a chronic constriction injury of the infraorbital nerve(ION-CCI)rat model. Methods:The ION-CCI models were established in male Sprague-Dawley rats and were randomly divided into a sham group,a TN group,a TN+low-dose CBZ treatment group(TN+20 mg/kg CBZ group),a TN+medium-dose CBZ treatment group(TN+40 mg/kg CBZ group),and a TN+high-dose CBZ treatment group(TN+80 mg/kg CBZ group).The mechanical pain threshold in each group of rats was measured regularly before and after surgery.The expressions of BDNF and tyrosine kinase receptor B(TrkB)mRNA in TGs of rats in different groups were determined by real-time PCR,and the expression of BDNF protein on neurons in TGs was observed by immunofluorescence.Western Blotting was used to detect the protein expression of BDNF,TrkB,extracellular regulated protein kinases(ERK),and phospho-extracellular regulated protein kinases(p-ERK)in TGs of rats in different groups.The expression of BDNF in the serum of rats in different groups was detected by enzyme-linked immunosorbent assay(ELISA). Results:The results of mechanical pain sensitivity showed that there was no significant difference in the mechanical pain threshold in the right facial sensory area of the experimental rats in each group before surgery(all P>0.05).From the 3rd day after operation,the mechanical pain threshold of rats in the TN group was significantly lower than that in the sham group(all P<0.01),and the mechanical pain threshold of rats in the TN+80 mg/kg CBZ group,the TN+40 mg/kg CBZ group,and the TN+20 CBZ mg/kg group was higher than that in the TN group(all P<0.05).The BDNF and TrkB mRNA and protein expressions in TGs of rats in the TN group were higher than those in the sham group(all P<0.05),and those in the TN+80 mg/kg CBZ group,the TN+40 mg/kg CBZ group,and the TN+20 mg/kg CBZ group were lower than the TN group(all P<0.05).The p-ERK levels in TG of rats in the TN+80 mg/kg CBZ group,the TN+40 mg/kg CBZ group,and the TN+20 mg/kg CBZ group were significantly decreased compared with the TN group(all P<0.05).The BDNF and neuron-specific nuclear protein(NeuN)were mainly co-expressed in neuron of TGs in the TN group and they were significantly higher than those in the sham group(all P<0.05).The co-labeled expressions of BDNF and NeuN in TGs of the TN+ 80 mg/kg CBZ group,the TN+40 mg/kg CBZ group,and the TN+20 mg/kg CBZ group were lower than those in the TN group(all P<0.05).The results of ELISA showed that the level of BDNF in the serum of the TN group was significantly higher than that in the sham group(P<0.05).The levels of BDNF in the TN+80 mg/kg CBZ group,the TN+40 mg/kg CBZ group,and the TN+20 mg/kg CBZ group were lower than those in the TN group(all P<0.05).Spearman correlation analysis showed that the BDNF level in serum was negatively correlated with mechanical pain threshold(r=-0.650,P<0.01). Conclusion:CBZ treatment can inhibit the expression of BDNF and TrkB in the TGs of TN rats,reduce the level of BDNF in serum of TN rats and the phosphorylation of ERK signaling pathway,so as to inhibit TN.The serum level of BDNF can be considered as an indicator for the diagnosis and prognosis of TN.

MiR-21-5p alleviates trigeminal neuralgia in rats through down-regulation of voltage-gated potassium channel Kv1.1 / 中南大学学报(医学版)

Objective:Trigeminal neuralgia(TN)is a common neuropathic pain.Voltage-gated potassium channel(Kv)has been confirmed to be involved in the occurrence and development of TN,but the specific mechanism is still unclear.MicroRNA may be involved in neuropathic pain by regulating the expression of Kv channels and neuronal excitability in trigeminal ganglion(TG).This study aims to explore the relationship between Kv1.1 and miR-21-5p in TG with a TN model,evaluate whether miR-21-5p has a regulatory effect on Kv1.1,and to provide a new target and experimental basis for the treatment of TN. Methods:A total of 48 SD rats were randomly divided into 6 groups:1)a sham group(n= 12),the rats were only sutured at the surgical incision without nerve ligation;2)a sham+ agomir NC group(n=6),the sham rats were microinjected with agomir NC through stereotactic brain injection in the surgical side of TG;3)a sham+miR-21-5p agomir group(n=6),the sham rats were microinjected with miR-21-5p agomir via stereotactic brain injection in the surgical side of TG;4)a TN group(n=12),a TN rat model was constructed using the chronic constriction injury of the distal infraorbital nerve(dIoN-CCI)method with chromium intestinal thread;5)a TN+antagonist NC group(n=6),TN rats were microinjected with antagonist NC through stereotactic brain injection method in the surgical side of TG;6)a TN+miR-21-5p antagonist group(n=6),TN rats were microinjected with miR-21-5p antagonist through stereotactic brain injection in the surgical side of TG.The change of mechanical pain threshold in rats of each group after surgery was detected.The expressions of Kv1.1 and miR-21-5p in the operative TG of rats were detected by Western blotting and real-time reverse transcription polymerase chain reaction.Dual luciferase reporter genes were used to determine whether there was a target relationship between Kv1.1 and miR-21-5p and whether miR-21-5p directly affected the 3'-UTR terminal of KCNA1.The effect of brain stereotaxic injection was evaluated by immunofluorescence assay,and then the analogue of miR-21-5p(agomir)and agomir NC were injected into the TG of rats in the sham group by brain stereotaxic apparatus to overexpress miR-21-5p.The miR-21-5p inhibitor(antagomir)and antagomir NC were injected into TG of rats in the TN group to inhibit the expression of miR-21-5p.The behavioral changes of rats before and after administration were observed,and the expression changes of miR-21-5p and Kv1.1 in TG of rats after intervention were detected. Results:Compared with the baseline pain threshold,the facial mechanical pain threshold of rats in the TN group was significantly decreased from the 5th to 15th day after the surgery(P<0.05),and the facial mechanical pain threshold of rats in the sham group was stable at the normal level,which proved that the dIoN-CCI model was successfully constructed.Compared with the sham group,the expression of Kv1.1 mRNA and protein in TG of the TN group was down-regulated(both P<0.05),and the expression of miR-21-5p was up-regulated(P<0.05).The results of dual luciferase report showed that the luciferase activity of rno-miR-21-5p mimics and KCNA1 WT transfected with 6 nmol/L or 20 nmol/L were significantly decreased compared with those transfected with mimic NC and wild-type KCNA1 WT,respectively(P<0.001).Compared with low dose rno-miR-21-5p mimics(6 nmol/L)co-transfection group,the relative activity of luciferase in the high dose rno-miR-21-5p mimics(20 nmol/L)cotransfection group was significantly decreased(P<0.001).The results of immunofluorescence showed that drugs were accurately injected into TG through stereotaxic brain.After the expression of miR-21-5p in the TN group,the mechanical pain threshold and the expression of Kv1.1 mRNA and protein in TG were increased.After overexpression of miR-21-5p in the sham group,the mechanical pain threshold and the expression of Kv1.1 mRNA and protein in TG were decreased. Conclusion:Both Kv1.1 and miR-21-5p are involved in TN and miR-21-5p can regulate Kv1.1 expression by binding to the 3'-UTR of KCNA1.

The Effect of Chuanxiong （Rhizoma Chuanxiong） & Tianma （Rhizoma Gastrodiae） Herbal Pair on the Periorbital Mechanical Pain Threshold and AMPK/TRPA1 Pathway in the Trigeminal Ganglion of Migraine Model Rats / 中医杂志

ObjectiveTo explore the possible mechanism of Chuanxiong （Rhizoma Chuanxiong） & Tianma （Rhizoma Gastrodiae） herbal pair in treating migraines based on AMP-activated protein kinase （AMPK）/transient receptor potential A1 channel （TRPA1） pathway. MethodsForty-eight healthy male SD rats were randomly divided into control group， model group， and Chuanxiong Tianma medication group， with 16 rats in each group. The control group and model group were given 10 ml/kg of normal saline by gavage， while the Chuanxiong Tianma medication group was given 0.675 g/kg of Chuanxiong Tianma herbal pair by gavage， once daily for 8 consecutive days in both groups. Migraime model was performed before the last administration， with subcutaneous injection of 10 ml/kg of normal saline in the control group， and subcutaneous injection of 10 ml/kg of nitroglycerin in the model group and Chuanxiong Tianma medication group. The Von Frey filament was used to measure the periorbital mechanical pain threshold of rats. The enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of calcitonin gene-related peptide （CGRP） in rat serum and cerebrospinal fluid. The nitric oxide （NO） assay kit was used to determine the NO level in serum and cerebrospinal fluid. RT-PCR was usedto detect the mRNA expression levels of immediate-early genes in the trigeminal ganglion of rats （c-Fos）， CGRP， transient receptor potential V1 channel （TRPV1）， AMPK alpha subunit （PRKAA）， and TRPA1. Immunofluorescence was used to detect the number of c-Fos-positive cells in the trigeminal cervical complex （TCC） and the protein expression levels of phosphorylated AMPK （pAMPK） and TRPA1 in the trigeminal ganglion. ResultsCompared to those in the control group， the mechanical stimulation threshold and pAMPK protein expression in the model group decreased， while the levels of CGRP and NO in serum， c-Fos， CGRP， TRPV1 and TRPA1 mRNA levels in the trigeminal ganglion， TRPA1 protein expression， and the number of c-Fos-positive cells in the TCC significantly increased （P＜0.05）. Compared to those in the model group， the mechanical stimulation threshold and pAMPK protein expression in the Chuanxiong Tianma medication group significantly increased， while the levels of CGRP and NO in serum， c-Fos， CGRP， TRPV1 and TRPA1 mRNA levels in the trigeminal ganglion， TRPA1 protein expression， and the number of c-Fos-positive cells in the TCC significantly decreased （P＜0.05）. ConclusionChuanxiong Tianma herbal pair may improve migraine symptoms by regulating the AMPK/TRPA1 pathway in the trigeminal ganglion and increasing the mechanical pain threshold.

Research progress on the mechanisms of the latency and recurrence of herpes simplex virus type Ⅰ in trigeminal ganglion / 国际眼科杂志(Guoji Yanke Zazhi)

Herpes simplex keratitis(HSK), caused by the infection of herpes simplex virus type Ⅰ(HSV-1)in cornea, is a global blinding corneal disease. After the primary infection in ocular surface, HSV-1 is transported into trigeminal ganglion and establishes the life-lasting latency, and it results in recurrent keratopathy. In the process of studying the latent mechanism of HSV, it has been gradually recognized that both the virus itself and the host response regulate the latent process of HSV. In recent years, a large number of research results have been obtained on the molecular mechanisms of invasion, immunity, latency and recurrence of neurotropic viruses, which provide new ideas for the prevention and treatment of HSK. In the present review, the recent progress of HSV latency mechanism in trigeminal ganglion after the primary infection in corneal surface was introduced, and the unsolved basic and clinical problems in HSK were discussed.

Involvement of NLRP3 inflammasome in hyperalgesia induced by temporomandibular joint osteoarthritis / 安徽医科大学学报

Objective@#To investigate the role of nucleotidebinding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in hyperalgesia induced by temporomandibular joint osteoarthritis (TMJOA) in rats.@*Methods @#Twenty 6-week-old male SD rats were randomly divided into NS group and MIA group．The rat model of TMJOA was established by injection monosodium iodoacetate ( MIA) into the upper cavity of temporomandibular joint (TMJ) ．The changes of pain threshold in the TMJ region of rats after MIA injection were detected by Von Frey．The changes of condyle structure were observed by Hematoxylin-eosin ( HE ) and Safranin O-fast green stains．Histopathological changes of trigeminal ganglion (TG) were observed by HE stains．The expression and distribution of TG NLRP3 protein were detected by immunohistochemistry．Western blot was used to detect the protein levels of NLRP3 and interleukin (IL) -1 β in TG．The mRNA levels of NLRP3，apoptosis-associated speck-like protein (ASC) ，cysteinyl aspartate specific proteinase ( Caspase-1) ，IL-1β and IL-18 in TG were detected by quantitative real-time polymerase chain reaction ( qRT-PCR) . @*Results @#Compared to saline group，the pain threshold of experimental TMJ osteoarthritis rats decreased (P＜0. 05) ．TMJ and TG showed obvious pathological changes．The protein and mRNA levels of NLRP3 expressed in the tissues of rats in the TMJOA group increased (P ＜0. 05 ) . @*Conclusion@#NLRP3 inflammasome may be involved in the regulation of hyperalgesia in TMJOA rats.

TLR8 in the Trigeminal Ganglion Contributes to the Maintenance of Trigeminal Neuropathic Pain in Mice / 神经科学通报·英文版

Trigeminal neuropathic pain (TNP) is a significant health problem but the involved mechanism has not been completely elucidated. Toll-like receptors (TLRs) have recently been demonstrated to be expressed in the dorsal root ganglion and involved in chronic pain. Here, we show that TLR8 was persistently increased in the trigeminal ganglion (TG) neurons in model of TNP induced by partial infraorbital nerve ligation (pIONL). In addition, deletion or knockdown of Tlr8 in the TG attenuated pIONL-induced mechanical allodynia, reduced the activation of ERK and p38-MAPK, and decreased the expression of pro-inflammatory cytokines in the TG. Furthermore, intra-TG injection of the TLR8 agonist VTX-2337 induced pain hypersensitivity. VTX-2337 also increased the intracellular Ca

Implications of Transient Receptor Potential Cation Channels in Migraine Pathophysiology / 神经科学通报·英文版

Migraine is a common and debilitating headache disorder. Although its pathogenesis remains elusive, abnormal trigeminal and central nervous system activity is likely to play an important role. Transient receptor potential (TRP) channels, which transduce noxious stimuli into pain signals, are expressed in trigeminal ganglion neurons and brain regions closely associated with the pathophysiology of migraine. In the trigeminal ganglion, TRP channels co-localize with calcitonin gene-related peptide, a neuropeptide crucially implicated in migraine pathophysiology. Many preclinical and clinical data support the roles of TRP channels in migraine. In particular, activation of TRP cation channel V1 has been shown to regulate calcitonin gene-related peptide release from trigeminal nerves. Intriguingly, several effective anti-migraine therapies, including botulinum neurotoxin type A, affect the functions of TRP cation channels. Here, we discuss currently available data regarding the roles of major TRP cation channels in the pathophysiology of migraine and the therapeutic applicability thereof.

The molecular mechanism of the Tianma preparation in the treating migraine by adenosine pathway / 中风与神经疾病杂志

@#Objective　To investigate the effect of the active ingredients of Tianma preparation on the expression of calcitonin gene-related peptide（CGRP） and adenosine A1 receptor in migraine model rats. Methods　Eighty-four SPF rats were randomly divided into 7 groups （n=12）：sham operation group （group A），electrical stimulation of the trigeminal ganglion group（ESTG group），Sumatriptan group （group C），gastrodin group （group D），4-hydroxybenzyl alcohol group （group E），vanilanol group （group F），β-sitosterol group （group G）. The enzyme-linked immuno sorbent assay （ELISA），immunofluorescence and western-blot techniques were used to dected the effect of the active components of Tianma preparation on the expression of CGRP and adenosine A1 receptor. Results　Compared with group A，the expression of CGRP in trigeminal ganglia （TG） and trigeminal nucleus caudalis （TNC） in group B rats was significantly increased，while the expression of adenosine A1 receptor was significantly decreased，with statistically significant differences （P<0.01）. Compared with group B，the expression of CGRP in TG and TNC in group C and D was significantly decreased，and the expression of adenosine A1 receptor was significantly increased，with statistically significant differences （P<0.01）. There was no significant difference between group E，F，G and group B （P>0.05）. Compared with group C，the expression of CGRP and adenosine A1 receptor in TG and TNC of rats in group D was not statistically significant （P>0.05）. Conclusion　Like sumatriptan，The preventive application of gastrodin can alleviate the migraine attack，while the effects of vanillin，4-hydroxybenzyl alcoholand β-sitosterol were not good enough. In addition，gastrodin can inhibit the occurrence of migraine by activating adenosine A1 receptor and inhibiting the release of CGRP.

Electrophysiological monitoring of pain afferent pathway of the trigeminal nerve and its functional plasticity in response to occlusal interference in rats / 南方医科大学学报

OBJECTIVE@#To observe the effect of occlusal interference on the afferent pathway of the trigeminal nerve and neuronal excitability in the trigeminal subnucleus caudalis (SPVC) of rats by electrical stimulation of the trigeminal ganglion (TG) and extracellular recordings of SPVC activities.@*METHODS@#Twenty male Wistar rats were randomly divided into control group and model group (=10). In the model group, occlusal interference for 30 consecutive days was induced using light-cured flowable resin on the right maxillary molars. During occlusal interference, the pain sensitivity was scored with von Frey Fibers in the masseter. Simultaneous recordings of electrical activities from the SPVC, electrocardiogram, body temperature and electromyogram of the breath muscles of the anesthetized rats were performed, and the responses evoked by electrical stimulation of the TG were analyzed.@*RESULTS@#Compared with the control rats, the rats in the model group showed significantly increased pain sensitivity scores ( 0.05). Train stimulation (0.2 ms, 1 mA, 30 s, 100 Hz) of the TG significantly increased the discharge frequency of the SPVC only in the rats in the model group ( < 0.05).@*CONCLUSIONS@#The functional activities of the pain afferent pathway of the trigeminal nerve can be electrophysiologically monitored by electrical stimulation of the TG and extracellular recordings of SPVC activities in rats. Occlusal interference can increase the excitability of the neurons in the SPVC and enhance their sensitivities to TG afferent activation, suggesting the neural plasticity of the pain afferent pathway.

The expression changes of BDNF in trigeminal ganglia of rats with trigeminal neuralgia / 中国药理学通报

Aim: To observe the expression changes of brain-derived neurotropic factor (BDNF) and receptor TrkB in trigeminal ganglion (TG) of trigeminal neuralgia (TN) rats. Methods: Animal model of TN was established using the infraorbital nerve chronic injury compression model (ION-CCI). The sham operation group (sham group) and the TN model group were composed of randomly divided 180 - 220 g SD male rats. The mechanical threshold of the injury side of the two groups was determined. Quantitative real-time PCR (qPCR), immunohistochemistry and immunfluorescence methods were used to detect the expression of BDNF, TrkB, pro-inflammatory TNF-α and IL-1B in the injured TGs. Results: After two weeks of modeling, the mechanical pain threshold was significantly down-regulated in TN group compared to sham group (P<0. 05). The expression of BDNF and TrkB in TGs of TN group was significantly higher than that in sham operation group. Besides, the levels of pro-inflammatory factors TNF-a and IL-1β also significantly increased in TGs of TN group compared with sham group (P < 0. 05). Conclusions: The expression of BDNF and TrkB in TG of ION-CCI rats increases in trigeminal neuralgia group, which may be involved in the pathogenesis of trigeminal neuralgia and promote the pain transmission of trigeminal neuralgia.

Effect of chronic compression injury of trigeminal nerve root on expression of myelin basic protein and P75 in trigeminal ganglion cells / 解剖学报

Objective To investigate the effect of the interaction between satellite glial cells and neurons in the trigeminal ganglion of trigeminal neuralgia (TN) rat model. Methods In the TN rat model (n = 24) induced by trigeminal root entry zone chronic compression and sham group (n = 24), immunofluorescence and Western blotting were used to detect the expression of myelin basic protein (MBP), glial fibrillary acidic protein (GFAP) and of P75 neurotrophic factor receptor (P75) in the trigeminal ganglion. Results The expression of P75NTR in TN group was higher than that in the sham operation group, especially on the post-operation day (POD) 7 and 14 (P<0.01). The expression of MBP in the TN group was decreased after operation, which were significant lower than that in the sham operation group on POD 7 and 14 (P<0.05). While the expression of immunoreactive GFAP in the satellite glial cells in the TN group was higher than that in the sham operation group from POD 7 to POD 21 after operation (P<0.01). Conclusion The changes of MBP and P75NTR expression in neurons and the activation of satellite glial cells in trigeminal ganglion of the TN animal model may affect the interaction of neuron-satellite glial cells, which may be involved in the nociceptive information transmission from orofacial area to the central nervous system in the TN rats.

Advances on distribution and function of aquaporin 1 in the peripheral nervous system / 第二军医大学学报

Aquaporin 1 (AQP1) is an aquaporin distributed in the peripheral nervous system. It has been found in neurons and glial cells of peripheral nerve structures, including trigeminal ganglion, dorsal root ganglion and enteric nervous system. AQP1 may be involved in the regulation of water balance of ganglia and nerve fiber bundles in the peripheral nervous system under physiological and pathological conditions, and plays a key role in maintaining the intracellular and extracellular water balance of peripheral nervous system under pathological condition. Knowing the structure and function of AQP1 can contribute to the understanding of the pathophysiology of the nervous system, providing new ways and methods for clinical treatment. This review summarizes the recent researches on AQP1.

Role of neuron and non-neuronal cell communication in persistent orofacial pain

It is well known that trigeminal nerve injury causes hyperexcitability in trigeminal ganglion neurons, which become sensitized. Long after trigeminal nerve damage, trigeminal spinal subnucleus caudalis and upper cervical spinal cord (C1/C2) nociceptive neurons become hyperactive and are sensitized, resulting in persistent orofacial pain. Communication between neurons and non-neuronal cells is believed to be involved in these mechanisms. In this article, the authors highlight several lines of evidence that neuron-glial cell and neuron macrophage communication have essential roles in persistent orofacial pain mechanisms associated with trigeminal nerve injury and/or orofacial inflammation.

Comparison of efficacy of adriamycin chemo-ganglionectomy and radiofrequency thermocoagulation of gasserian ganglionin in treating craniofacial postherpetic neuralgia / 中华麻醉学杂志

Objective To compare the efficacy of adriamycin chemo-ganglionectomy and radiofre-quency thermocoagulation ( RFT ) of semilunar ganglion in treating craniofacial postherpetic neuralgia ( PHN) . Methods A total of 95 patients with PHN in the areas innervated by maxillary and mandibular divisions of trigeminal nerve, aged 55-90 yr, with the course of disease 6 months-3 yr, were divided into 2 groups using a random number table method: adriamycin chemo-ganglionectomy group ( ADM group, n=48) and RFT group ( n=47) . Hartel anterior approach to puncture was performed via the foramen ovale un-der the guidance of CT in two groups. In group ADM, 0. 5％ adriamycin 2. 5 mg ( 0. 5 ml) was injected via the foramen ovale, and RFT of gasserian ganglion was performed in group RFT. Visual Analog Scale (VAS) and the short-form McGill pain questionnaire (SF-MPQ) scores were evaluated before and after treatment. The rate of effective treatment was calculated, and treatment-related complications were recor-ded. Results Compared with group RFT, no significant change was found in VAS or SF-MPQ scores be-fore treatment, VAS and SF-MPQ scores were increased and the rate of effective treatment was decreased at 1 and 7 days after treatment, VAS and SF-MPQ scores were decreased and the rate of effective treatment was increased at 6 and 12 months after treatment, the incidence of facial numbness, hypoesthesia, masti-catory muscle weakness and weakened corneal reflex was decreased in group ADM ( P<0. 05) . Conclusion Compared with semilunar ganglion RFT, the long-term efficacy of adriamycin chemo-ganglionectomy of semilunar ganglion in treating craniofacial PHN is enhanced, and the safety is higher.

NLRP3 inflammasome signaling as an early molecular response is negatively controlled by miR-186 in CFA-induced prosopalgia mice

The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most frequently studied in the central nervous system and has been linked to neuropathic pain. In this study, a post-translational mechanism of microRNA (miR)-186 via regulating the expression of NLRP3 in the complete Freund's adjuvant (CFA)-treated mice was investigated. The injection of CFA was used to induce trigeminal neuropathic pain in mice. miRs microarray chip assay was performed in trigeminal ganglions (TGs). CFA treatment significantly increased the mRNA expression of NLRP3, interleukin (IL)-1β, and IL-18 in TGs compared to the control group. Moreover, 26 miRs were differentially expressed in TGs from trigeminal neuropathic pain mice, and the expression of miR-186 showed the lowest level of all the miRs. Further examination revealed that NLRP3 was a candidate target gene of miR-186. We delivered miR-186 mimics to CFA-treated mice. The head withdrawal thresholds of the CFA-treated mice were significantly increased by miR-186 mimics injection compared with CFA single treatment. The mRNA and protein expression of NLRP3, IL-1β, and IL-18 in TGs from trigeminal neuropathic pain mice were significantly inhibited by miR-186 mimics treatment compared to the CFA group. miR-186 was able to suppress the neuropathic pain via regulating the NLRP3 inflammasome signaling.

Description of an in vivo oral mucosa HSV-1 infection model in mice

In this work, we established an in vivo murine model of herpes simplex virus type 1 (HSV1) infection involving inoculation by scarification of the oral mucosain order to study its dissemination towards the trigeminal ganglion (TG). Both viral DNA and infectious virions were detected on the third day postinfection (p.i.). Viral proteins revealed by immunohistochemistry were mainly found at seven days p.i., when the latencyassociated transcript (LAT) was also detected. This model simulated the dissemination process of HSV1, which could be used to study herpes pathogenesis starting in the oral mucosa (AU)

Con el propósito de estudiar la dispersión de del Herpes Simplex Virus tipo 1 (HSV1) desde la mucosa oral hasta los ganglios trigeminales, en el presente trabajo se estableció un modelo de infección en ratones, haciendo inoculación por escarificación en la mucosa oral. Tanto ADN viral como viriones infecciosos se detectaron en los ganglios trigeminales al dia 3 postinfección (p.i.). Las proteínas virales se detectaron principalmente al día 7 p.i. cuando los transcritos asociados a latencia también fueron encontrados. El modelo de infección simula adecuadamente el proceso de dispersión del HSV1 y puede ser usado para el estudio de la patogénesis por herpes después de la infección primaria en la mucosa oral (AU)

The effect of capsaicin on expression patterns of CGRP in trigeminal ganglion and trigeminal nucleus caudalis following experimental tooth movement in rats

ABSTRACT Objectives The aim of this study was to explore the effect of capsaicin on expression patterns of calcitonin gene-related peptide (CGRP) in the trigeminal ganglion (TG) and trigeminal subnucleus caudalis (Vc) following experimental tooth movement. Material and Methods Male Sprague-Dawley rats were used in this study and divided into small-dose capsaicin+force group, large-dose capsaicin+force group, saline+force group, and no force group. Closed coil springs were used to mimic orthodontic forces in all groups except for the no force group, in which springs were inactivated. Capsaicin and saline were injected into periodontal tissues. Rats were euthanized at 0 h, 12 h, 1 d, 3 d, 5 d, and 7 d following experimental tooth movement. Then, TG and Vc were obtained for immunohistochemical staining and western blotting against CGRP. Results Immunohistochemical results indicated that CGRP positive neurons were located in the TG, and CGRP immunoreactive fibers were distributed in the Vc. Immunohistochemical semiquantitative analysis and western blotting analysis demonstrated that CGRP expression levels both in TG and Vc were elevated at 12 h, 1 d, 3 d, 5 d, and 7 d in the saline + force group. However, both small-dose and large-dose capsaicin could decrease CGRP expression in TG and Vc at 1 d and 3 d following experimental tooth movement, as compared with the saline + force group. Conclusions These results suggest that capsaicin could regulate CGRP expression in TG and Vc following experimental tooth movement in rats.

Cannabinoids increase mechanosensitivity of trigeminal ganglion neurons innervating the inner walls of rat anterior chambers via activation of TRPA1 / 华中科技大学学报（医学）（英德文版）

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 DiI). 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 DiI-labeled TG neurons. WIN enhanced mechanosensitive currents via TRPA1 activation in FAST DiI-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.

Effect of topiramate on NACHT-LRR-PYD-containing protein 3 inflammasome and interleukin-1β levels in trigeminal ganglion of migraine rats / 中华神经医学杂志

Objective To investigate the effect oftopiramate on NACHT-LRR-PYD-containing protein 3 (NALP3) inflammasome and intedeukin (IL)-1β levels in trigeminal ganglion of migraine rats.Methods Forty adult male Sprague Dawley rats were randomly divided into blank group,saline group,model group,prevention control group,10 mg/kg topiramate group,30 mg/kg topiramate group,60 mg/kg topiramate group,and 90 mg/kg topiramate group (n=5).Inflammatory soup was used to stimulate the dual matter of rats repeatedly to induce migraine models:rats in the blank group were without any treatment,those in the saline group were given saline to stimulate the dual matter,different concentrations of topiramate group were given to migraine models of the 10 mg/kg topiramate group,30 mg/kg topiramate group,60 mg/kg topiramate group,and 90 mg/kg topiramate group,respectively,and migraine models of the prevention control group were given saline containing 1％ Tween80.Three h after the last treatment,the expressions of NALP3,caspase-1 precursor (pro-caspase-1),caspase-1 and IL-1β in trigeminal ganglion of rats were detected by Western blotting,and the best concentration oftopiramate was chosen for subsequent immunofluorescence experiments.Ten healthy male adult SD rats were randomly divided into control group and topiramate group (n=5);the expression levels of NALP3,caspase-1 and IL-1β in trigeminal ganglion of the two groups were detected by immunofluorescence.Results The expression levels ofNALP3,pro-caspase-1,caspase-1 and IL-1β were not significantly different between saline group and blank group (P＞0.05);the expression levels ofNALP3,pro-caspase-1,caspase-1 and IL-1β in the model group were significantly higher than those in the saline group (P＜0.05).The expression levels of NALP3,pro-caspase-1,caspase-1 and IL-1β in 60 mg/kg topiramate group and 90 mg/kg topiramate group were significantly lower than those in the prevention control group (P＜0.05).The fluorescence intensity ofNALP3,caspase-1 and IL-1β in topiramate group was significantly lower than that in control group.Condusion Topiramate can inhibit the expression of NALP3 inflammasome and IL-1β in the trigeminal ganglion of migraine rat models,and it is likely to be one of the important mechanisms for the prevention of migraine.

Characterization of a murine neuron-enriched model of primary trigeminal ganglia cultures to study the interferon-ß antiviral effect against Herpes Simplex Virus type 1 / Caracterización de un modelo murino de cultivos primarios de ganglio trigeminal enriquecido en neuronas para el estudio del efecto antiviral del interferón-ß frente al virus Herpes simple tipo 1

Objective: To characterize a neuron-enriched primary TG culture and evaluate interferon- β expression and activity after HSV-1 infection. Materials and methods: The percentage of neurons present in cultures was assessed by neurofilament immunocytochemistry. Cultures were treated with interferon- β and infected with HSV-1, then viral antigen positive cells were counted and interferon- βexpression was assessed by quantitative PCR. Results: The culture contained 15% neurons and 85% non-neuronal cells. A cytopathic effect was observed, associated with high viral spread (72.9% neurons and 48.3% non-neuronal cells were positive for viral antigen). Interferon- β treatment impaired the cytopathic effect and decreased the infected neurons to 16.7% and infected non-neuronal cells to 7.8%. Viral infection at 6 h postinfection significantly increased the interferon- β transcripts by 18.2 fold, while at 18 h postinfection Interferon pre-treatment in infected cultures increased interferon- β transcription by 3.7 fold. Discussion: This culture model contained 15% neurons, which is 10 times higher compared to other reported cultures, and non-neuronal cells comprised 85% of cells in this culture. All types of cells were found to be infected, which is similar to that reported during acute infections in vivo . Additionally, interferon- βdecreased the infected cells, avoiding the cytopathic effect, which is similar to that reported in swine TG cultures. Conclusions: A neuron-enriched primary TG model was characterized. Interferon- β treatment protected cells from cytopathic effects and viral spread, while viral infection up-regulated interferon- β expression. This result means that interferon- β exerts an important antiviral effect against HSV-1 in these cultures.

Objetivo: Caracterizar un cultivo primario de ganglio trigeminal (GT) enriquecido en neuronas y evaluar la expresión de interferón- y su actividad frente a la infección con Herpes simple tipo 1 (HSV-1). Materiales y métodos: El porcentaje de neuronas fue determinado por inmunocitoquímica para neurofilamento. Los cultivos fueron tratados con interferón- β e infectados con HSV-1, y se cuantificaron las células positivas para antígeno viral por inmunocitoquímica y la expresión de interferón- β por PCR cuantitativa. Resultados: El cultivo presentó un 15% de neuronas y 85% de células no neuronales. Se encontró efecto citopático, asociado a una alta diseminación de la infección (72,9% neuronas y 48,3% de células no neuronales positivas para antígeno viral). El interferón- β evitó la aparición de efecto citopático y disminuyó las células infectadas a 16,7% en neuronas y a 7,8% las células no neuronales. La infección viral incrementó la expresión de transcritos de interferón- β 18,2 veces a las 6 h de infección, mientras que a las 18 h post infección el tratamiento con interferón incrementó esta expresión 3,7 veces. Discusión: Los cultivos presentaron un 15% de neuronas, lo cual es 10 veces más que en otros cultivos reportados. Las células no neuronales representan el 85% de las células del cultivo, y se evidenció que todos los tipos de células se infectaron; similar a lo que ha sido reportado durante infecciones agudas in vivo . Adicionalmente, el interferón- β disminuyó el porcentaje de células infectadas y evitó la aparición de efecto citopático, similar a lo que ha sido reportado en cultivos de GT porcino. Conclusiones: Se caracterizó un modelo de cultivo primario de GT enriquecido en neuronas. Interferón- β protegió las células del efecto citopático y la diseminación viral mientras que la infección viral incrementó la expresión de interferón- β. Por lo tanto, el interferón- β ejerció un papel antiviral importante frente al HSV-1 en estos cultivos.