• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.419-425
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• 2010

Mast cells are activated by specific allergens and also by various nonspecific stimuli, which might induce physical urticaria. This study investigated the functional expression of temperature sensitive transient receptor potential vanilloid (TRPV) subfamily in the human mast cell line (HMC-1) using whole-cell patch clamp techniques. The temperature of perfusate was raised from room temperature (RT, $23{\sim}25^{\circ}C$) to a moderately high temperature (MHT, $37{\sim}39^{\circ}C$) to activate TRPV3/4, a high temperature (HT, $44{\sim}46^{\circ}C$) to activate TRPV1, or a very high temperature (VHT, $53{\sim}55^{\circ}C$) to activate TRPV2. The membrane conductance of HMC-1 was increased by MHT and HT in about 50% (21 of 40) of the tested cells, and the I/V curves showed weak outward rectification. VHT-induced current was 10-fold larger than those induced by MHT and HT. The application of the TRPV 4 activator $3{\alpha}$-phorbol 12,13-didecanoate ($4{\alpha}$ PDD, $1\;{\mu}M$) induced weakly outward rectifying currents similar to those induced by MHT. However, the TRPV3 agonist camphor or TRPV1 agonist capsaicin had no effect. RT-PCR analysis of HMC-1 demonstrated the expression of TRPV4 as well as potent expression of TRPV2. The $[Ca^{2+}]_c$ of HMC-1 cells was also increased by MHT or by $4{\alpha}$ PDD. In summary, our present study indicates that HMC-1 cells express $Ca^{2+}$-permeable TRPV4 channels in addition to the previously reported expression of TRPV2 with a higher threshold of activating temperature.

• Biomolecules & Therapeutics
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• 제20권6호
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• pp.550-555
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• 2012

TRPA1 and TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels. TRPA1 and TRPV1 are often co-expressed in sensory neurons and play an important role in somatosense such as cold, pain, and irritants. The first leaves of Kalopanax pictus Nakai (Araliaceae) have long been used as a culinary ingredient in Korea because of their unique chemesthetic flavor. In this study, we observed the intracellular $Ca^{2+}$ response to cultured cells expressing human TRPA1 (hTRPA1) and human TRPV1 (hTRPV1) by $Ca^{2+}$ imaging analysis to investigate the ability of the first leaves of K. pictus to activate the hTRPA1 and hTRPV1. An 80% ethanol extract of K. pictus (KPEx) increased intracellular $Ca^{2+}$ influx in a response time- and concentration-dependent manner via either hTRPA1 or hTRPV1. KPEx-induced response to hTRPA1 was markedly attenuated by ruthenium red, a general blocker of TRP channels, and HC-030031, a specific antagonist of TRPA1. In addition, the intracellular $Ca^{2+}$ influx attained with KPEx to hTRPV1 was mostly blocked by ruthenium red, and capsazepine, a specific antagonist of TRPV1. These results indicate that KPEx selectively activates both hTRPA1 and hTRPV1, which may provide evidence that the first leaves of K. pictus primarily activate TRPA1 and TRPV1 to induce their unique chemesthetic sense.

• Genomics & Informatics
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• 제3권1호
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• pp.24-29
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• 2005

TRPV2 is a non-specific cation channel expressed in sensory neurons, and activated by noxious heat. Particularly, TRPV2 has six transmembrane domains and three ankyrin repeats. TRPV2 has been cloned from various species such as human, rat, and mouse. Oocytes of Xenopus laevis - an African clawed frog ­have been widely used for decades in characterization of various receptors and ion channels. The functional property of rat TRPV2 was also identified by this oocyte expression system. However, no TRPV2 orthologue of Xenopus laevis has been reported so far. Hence, we have focused to clone a TRPV2 orthologue of Xenopus laevis with the aid of bioinformatic tools. Because the genome sequence of Xenopus laevis is not available until now, a genome sequence of Xenopus tropicalis - a close relative species of Xenopus laevis - was used. After a number of bioinformatic searches in silico, a predicted full-length sequence of TRPV2 orthologue of Xenopus tropicalis was found. Based on this predicted sequence, various approaches such as RT-PCR and 5' -RACE technique were applied to clone a full length of Xenopus laevis TRV2. Consequently, a full-length Xenopus laevis TRPV2 was cloned from heart cDNA.

• 한방비만학회지
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• 제18권2호
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• pp.57-63
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• 2018

Objectives: Metabolic syndrome is defined by a cluster of major cardiovascular risk factors: obesity, insulin resistance, dyslipidemia, and arterial hypertension. Several members of a large family of nonselective cation entry channels, e.g., transient receptor potential vanilloid 4 (TRPV4) channels have been associated with the development of dyslipidemia and hypertension. The purpose of this study was to investigate the effects of Leejung-tang (Lizhong-tang), Rikkunshito, and Bojungikgi-tang (Buzhongyiqi-tang) on TRPV4 channel. Methods: Human embryonic kidney 293 cells stably transfected with the TRPV4 expression vectors were maintained in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 1% penicillin/streptomycin, $5{\mu}g/mL$ blasticidin, and 0.4 mg/mL zeocin in a humidified 20% $O_2/10%$ $CO_2$ atmosphere at $37^{\circ}C$. Whole-cell patch clamp recordings were obtained using an Axopatch 700B amplifier and pClamp v.10.4 software (Molecular Devices, San Jose, CA, USA), and signals were digitalized at 5 kHz using Digidata 1422A. Results: Leejung-tang and Rikkunshito (10, 30 and 50 mg/mL) had no effects on the TRPV4 whole-cell currents at dose dependent manner. However, Bojungikgi-tang (10, 30, and 50 mg/mL) inhibited the TRPV4 whole-cell currents in a dose dependent manner and the half maximal inhibitory concentration (IC50) of Bojungikgi-tang was 18.2 mg/mL. Conclusions: These results suggest that Bojungikgi-tang plays an important roles to inhibit the TRPV4 channel, suggesting that Bojungikgi-tang is considered one of the candidate agents for the treatment of metabolic syndrome such as dyslipidemia and hypertension.

• The Korean Journal of Pain
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• 제34권3호
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• pp.262-270
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• 2021

Background: Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel implicated in pain sensation in response to heat, protons, and capsaicin (CAPS). It is well established that TRPV1 is involved in mechanical allodynia. This study investigates the effect of Ononis spinosa (Fabaceae) in CAPS-induced mechanical allodynia and its mechanism of action. Methods: Mechanical allodynia was induced by the intraplantar (ipl) injection of 40 ㎍ CAPS into the left hind paw of male Wistar rats. Animals received an ipl injection of 100 ㎍ O. spinosa methanolic leaf extract or 2.5% diclofenac sodium 20 minutes before CAPS injection. Paw withdrawal threshold (PWT) was measured using von Frey filament 30, 90, and 150 minutes after CAPS injection. A molecular docking tool, AutoDock 4.2, was used to study the binding energies and intermolecular interactions between O. spinosa constituents and TRPV1 receptor. Results: The ipsilateral ipl injection of O. spinosa before CAPS injection increased PWT in rats at all time points. O. spinosa decreased mechanical allodynia by 5.35-fold compared to a 3.59-fold decrease produced by diclofenac sodium. The ipsilateral pretreatment with TRPV1 antagonist (300 ㎍ 4-[3-Chloro-2-pyridinyl]-N-[4-[1,1-dimethylethyl] phenyl]-1-piperazinecarboxamide [BCTC]) as well as the β2-adrenoreceptor antagonist (150 ㎍ butoxamine) attenuated the action of O. spinosa. Depending on molecular docking results, the activity of the extract could be attributed to the bindings of campesterol, stigmasterol, and ononin compounds to TRPV1. Conclusions: O. spinosa alleviated CAPS-induced mechanical allodynia through 2 mechanisms: the direct modulation of TRPV1 and the involvement of β2 adrenoreceptor signaling.

• 동의생리병리학회지
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• 제32권1호
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• pp.35-42
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• 2018

TRPA1 and TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels. TRPA1 and TRPV1 are often co-expressed in sensory neurons and play an important role in mechanical hyperalgesia and allodynia during neuropathic pain. Scutellariae Radix was reported to possess anti-inflammation properties and similar patterns of therapeutic action against different diseases. also Baicalin(a known principal constituent of Scutellaria Radix) was shown to down-regulate the mRNA expression levels of TRPV1. In this study, we observed the effects of Scutellariae Radix extract(SRE) in neuropathic pain induced SD rats via modulation of TRPV1 and TRPA1. Oral administration of a Scutellaria Radix extract(in doses of 300mg/kg, SRE(300)) showed a meaningful increase in the withdrawal threshold of mechanical allodynia and showed a meaningful decrease in the expression of c-fos compared to the control group. SRE(100) and SRE(300) showed a meaningful decrease in the expression of TRPV1 level compared to the control group. These results suggest that Scutellariae Radix extract could decrease mechanical allodynia by down-regulate the TRPV1 on the model of neuropathic pain.

• Applied Microscopy
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• 제42권1호
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• pp.27-33
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• 2012

Transient receptor potential ankyrin 1 (TRPA1)은 $17^{\circ}C$보다 낮은 유해한 온도 및 자극적인 화합물에 의해 활성화되며 통각을 조절한다. 그러나 TRPA1에 의한 통각정보가 어떻게 처리되는지에 대한 정보는 많이 알려져 있지 않다. 본 연구에서는 흰쥐의 삼차신경절에서 TRPA1을 발현하는 신경세포의 특성을 규명하기 위해서, 면역형광기법을 사용하여 TRPA1을 발현하는 신경세포에서 다른 통각수용기들에서 발현되며, 특징적인 기능을 수행하는 수용기인 transient receptor potential vanilloid 1 (TRPV1)와 $P2X_3$와의 발현양상을 조사하였다. TRPA1을 발현하는 신경세포에서 열감각수용기이며, 통각표지자인 TRPV1과의 공존을 조사해 본 결과, TRPA1 면역양성 신경세포 중에서 58.8% (328/558)가 TRPV1을 동시에 발현하였으며, 41.2% (230/558)가 TRPA1만 발현하고 TRPV1을 발현하지 않았다. TRPA1을 발현하는 신경세포 중 TRPV1을 동시에 발현하는 신경세포는 대부분 작거나 중간크기였다. 또한 TRPA1과 조직의 손상, 그리고 염증 시 분비되는 ATP와 결합하는 $P2X_3$와의 공존을 조사해 본 결과, TRPA1 면역양성 신경세포 중에서 26.1% (310/1186)의 신경세포에서 $P2X_3$을 동시에 발현하였으며, 73.9% (876/1186)의 신경세포에서 TRPA1만 발현하였다. TRPA1을 발현하는 신경세포 중 $P2X_3$을 동시에 발현하는 신경세포는 대부분 작거나 중간크기였다. 이러한 결과는 TRPA1을 발현하는 신경세포가 TRPV1 또는 $P2X_3$를 동시에 발현함으로써 동일한 신경세포가 구강안면영역에서의 냉통각 및 열통각을 조절할 뿐 아니라, 냉통각 및 염증성동통을 동시에 전달하는 등 하나의 신경세포가 여러 가지 통각의 전달에 관여하는 것을 시사한다.

• The Korean Journal of Pain
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• 제34권1호
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• pp.66-71
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• 2021

Background: Trigeminal neuralgia is a debilitating craniofacial pain syndrome that is characterized by paroxysms of intense, short-lived electric shock-like pains in the trigeminal nerve distribution. Recently, the presence of triggers has become one of the key diagnostic criteria in the 3rd edition of the International Classification of Headache Disorders. Light touch is the most common trigger, however other non-mechanical triggers, such as cold weather and certain foods, have been thought to provoke trigeminal neuralgia anecdotally. We aimed to characterize the prevalence and characteristics of these atypical triggers. Methods: We conducted a retrospective, cross-sectional study of atypical triggers in trigeminal neuralgia patients seen in a tertiary pain clinic in Singapore. Patients were recruited via clinic records, and study data were identified from physician documentation. Results: A total of 60 patients met the inclusion criteria. Weather triggers were observed in 12 patients (20%), of which five patients (8%) reported strong winds, 4 patients (7%) reported cold temperatures, and 3 patients (5%) reported cold winds as triggers. Fifteen patients (25%) had a specific food trigger, of which 10 patients (17%) reported hard or tough food, 5 patients (8%) reported hot/cold food, 4 patients (7%) reported spicy food, and 2 patients (3%) reported sweet food as triggers. Conclusions: Although trigeminal neuralgia is most commonly triggered by mechanical stimuli, atypical triggers such as cold temperatures and certain foods are seen in a significant proportion of patients. These atypical triggers may share a common pathway of sensory afferent Aδ fiber activation.