瞬时受体电位通道研究进展

瞬时受体电位通道(TRP channels)是位于细胞膜上的一类重要的阳离子通道超家族.根据氨基酸序列的同源性,将已发现的28种哺乳动物,TRP通道分为:TRPC、TRPV、TRPM、TRPA、TRPP和TRPML 6个亚家族.所有的TRP通道都具有6次跨膜结构域.不同的TRP通道对钙离子和钠离子选择性不同.TRP通道分布广泛,调节机制各异,通过感受细胞内外环境的各种刺激,参与痛温觉、机械感觉、味觉的发生和维持细胞内外环境的离子稳态等众多生命活动.     

瞬时受体电位通道在心脑血管系统疾病中的研究进展

瞬时受体电位(TRP)通道是一类重要的非选择性阳离子通道,其家族成员众多,参与多种生理病理过程。其中,TRP通道的异常表达及功能改变与心脑血管疾病的发生发展密切相关。近年研究发现,通过拮抗或者激活TRP通道可以调节血管内皮和血管平滑肌功能,参与心脑血管疾病的调控。该文主要从TRP通道的结构及各亚家族蛋白基于血管内皮和血管平滑肌对心脑血管系统疾病的作用及机制作一综述,为心脑血管疾病的防治提供新思路。     

瞬时受体电位通道与妊娠期高血压疾病

瞬时受体电位通道是一类非选择性阳离子通道,其中大部分对Ca2 通透,广泛表达于全身组织,参与多种生命活动如视觉、听觉、嗅觉、疼痛信号传导、肠蠕动、矿物质吸收、体液平衡、呼吸道过敏、细胞生长/死亡和性行为的调节.其对血压调节功能在高血压的发生中的作用渐为人们所重视.本文就瞬时受体电位通道和血管功能的关系及与妊娠期高血压疾病的关系作一扼要综述.旨在为该病的的发病机制研究和防治策略制定提供新的线索和思路.     

瞬时受体电位M8离子通道功能及其翻译后修饰调节机制

瞬时受体电位M8(transient receptor potential melastatin 8, TRPM8)又称冷及薄荷醇感受器,位于细胞膜或细胞器膜上,是瞬时受体电位(transient receptor potential, TRP)通道超家族中的一员。TRPM8通道分布广泛,是一个非选择性阳离子通道,可作为冷热传感器和冷痛传感器进行信号传导,参与众多生物过程的调节,在维持细胞内外稳态、控制离子进出细胞方面具有重要作用。研究发现,蛋白质翻译后修饰(post-translational modification, PTM)通过调控TRPM8通道的功能,进而影响多种疾病的发生和发展。因此,探究TRPM8的翻译后修饰的过程,对深入了解TRPM8的功能及调控机制是十分必要的。目前,已报道的TRPM8翻译后修饰包括磷酸化、泛素化和糖基化等,它们能够调控蛋白质的相互作用和改变TRPM8离子通道的活性,从而调控细胞增殖、迁移和凋亡。值得注意的是,TRPM8的表达与前列腺癌、膀胱癌和乳腺癌等多种癌症密切相关。本文将从TRPM8离子通道的结构出发,系统地阐述TRPM8蛋白翻译后修饰和激动剂、...     

瞬时感受器电位通道与疾病

哺乳动物瞬时感受器电位(transient receptor potential,TRP)通道超家族由TRPC、TRPM、TRPV、TRPA、TRPP和TRPML六个亚家族组成。这些亚家族的29个离子通道几乎表达于所有的组织和细胞。大多对单价和二价阳离子都有通透性。TRP通道与多种生物学功能有关,包括高血压、温度觉、血管炎症、刺激感、肿瘤增生、细胞内离子稳态及神经细胞信号转导。对这些通道的生理功能及其与人类疾病的关系的研究有助于开发具有潜在治疗价值的TRP通道调节剂。     

瞬时受体电位香草酸亚型1激活释放的P物质在小鼠急性心肌梗死后凋亡中的保护作用

瞬时受体电位香草酸亚型1 (transient receptor potential vanilloid 1, TRPV1)在心肌缺血激活后可传导心绞痛信号和释放P物质(substance P, SP).SP是速激肽家族成员之一,主要通过结合并激活神经激肽1 (neurokinin 1,NK1)受体发挥作用. TRPV1和SP在缺血性心脏病中对心功能的恢复和重塑有一定保护作用,但对心肌梗死后凋亡的作用及具体机制尚不明确.本研究用TRPV1基因敲除(TRPV1-/- )小鼠和野生型(wide type, WT)小鼠建立心肌梗死模型,并外源性给予SP和NK1受体拮抗剂RP67580,用TTC染色法观察梗死的面积,TUNEL法检测心肌细胞凋亡指数,Western印迹方法检测caspase-3、Bcl-2、Bax、p53的蛋白表达.结果发现,心肌梗死24 h后,TRPV1-/-小鼠比WT小鼠梗死面积更大,凋亡指数和caspase-3活性更高,Bcl-2/Bax和p53蛋白表达更低. SP预处理可以明显缩小TRPV1-/-小鼠梗死面积,降低凋亡指数、caspase-3活性和升高Bcl-2/Bax比值,而在WT小鼠中改善不明显.外源性给予RP67580,阻断SP与NK1受体结合后,与相应对照组相比,WT小鼠梗死面积和凋亡指数更大,caspase-3蛋白表达更高,Bcl-2/Bax比值更低;TRPV1-/-小鼠与相应对照组比较,凋亡指数和caspase-3表达升高,Bcl-2/Bax比值降低.研究结果表明,SP可能介导了TRPV1在急性心肌梗死后凋亡中的保护作用.     

大鼠局灶性脑缺血再灌注损伤后纹状体和海马区瞬时受体电位通道蛋白4的表达增加

实验在大鼠大脑中动脉阻塞性脑缺血(middle cerebral arterv occlusion,MCAO)模型上采用Western Blot方法检测脑缺血再灌注不同时程(6h、12h、1d、3d)脑组织中瞬时受体电位通道蛋白4(transient receptor potential channel4,TRPC4)的表达情况,并与正常对照组相比,结果显示,12 h、1 d、3 d组纹状体、海马区域TRPC4含量明显高于正常组(P<0.05)。采用免疫组织化学定位检测,显示TRPC4主要表达在神经元细胞膜上;免疫组化阳性细胞统计分析显示,在不同时程缺血组中纹状体、海马区域TRPC4的表达与正常组相比有所增加,其中纹状体、海马区缺血再灌注1 d、3 d组缺血同侧1RPC4阳性细胞升高显著(P<0.05)。脑缺血再灌注损伤后TRPC4相对含量增加,提示TRPC4可能参与脑缺血引起的急性和迟发性神经元损伤。     

温度驯化对布氏田鼠肝脏温敏瞬时受体电位通道蛋白表达的影响

肝脏是哺乳动物基础代谢产热的关键器官。温敏瞬时受体电位通道蛋白(Thermosensitive transient receptor potential channels,Thermo-TRPs)参与了调控肝细胞的生理功能。为了解Thermo-TRPs是否参与肝脏的代谢产热,以成年布氏田鼠(Lasiopodomys brandtii)为研究对象,测定了不同驯化温度下6种Thermo-TRPs在肝脏中的表达,分析其与肝脏产热相关蛋白和信号通路蛋白的关系。结果显示：(1)与高温组相比,低温增加了肝脏解偶联蛋白1(uncoupling protein 1,UCP1)的表达;而与常温组相比,低温降低了肝脏解偶联蛋白3 (uncoupling protein 3,UCP3)的表达;(2) 6种Thermo-TRPs均在肝脏中表达,与高温组相比,低温显著降低了TRP vanilloid 4 (TRPV4)的表达,同时显著增加了腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)的表达;(3)低温显著增加了布氏田鼠血清三碘甲状腺原氨酸(T₃)...     

瞬时感受器电位M2通道抗原位点的兔单抗特异性检测

目的：筛选特异性较高的抗体以推动对瞬时感受器电位M2（TRPM2）通道结构和功能的研究。方法：以野生型昆明种小鼠大脑皮层、人胚肾293细胞、未诱导的TRPM2细胞及四环素诱导的TRPM2细胞为标本,采用免疫印迹和免疫荧光方法,以被检测抗体为一抗,荧光分子结合的抗体为二抗,根据170kD（TRPM2通道蛋白分子量）位置上是否有特异性条带,检测兔单抗的特异性。结果：抗体98927对鼠源TRPM2通道有特异性,抗体40622,抗体98721,抗体98921对人源TRPM2通道有特异性,另外抗体98721对鼠源TRPM2通道的突变型有特异性。结论：作为分子探针,抗体98927、40622、98721、98921可用于TRPM2通道结构和功能研究。     

冷受体TRPM8在冷感知中的作用和调节

感觉体内外温度变化是生物与生俱来的能力之一,可有效调节机体体温,参与防御反应和减少自身损伤等.瞬时受体电位melastatin 8(transient receptor potential melastatin 8,TRPM8)是机体重要的一种冷受体,它的缺乏使动物对冷的敏感性减弱,对冷物质模拟物如薄荷醇和冰片等反应能力降低.TRPM 8的活性受细胞膜电位和膜脂的影响,它参与了体温调节和痛觉反应等.这些研究一方面有助于帮助理解机体对冷的感知机理,另一方面也使TRPM8有望成为新的药物作用靶点.     

Ca2+-dependent regulation and binding of calmodulin to multiple sites of Transient Receptor Potential Melastatin 3 (TRPM3) ion channels

TRPM3 proteins assemble to Ca²⁺-permeable cation channels in the plasma membrane, which act as nociceptors of noxious heat and mediators of insulin and cytokine release. Here we show that TRPM3 channel activity is strongly dependent on intracellular Ca²⁺. Conceivably, this effect is attributed to the Ca²⁺ binding protein calmodulin, which binds to TRPM3 in a Ca²⁺-dependent manner. We identified five calmodulin binding sites within the amino terminus of TRPM3, which displayed different binding affinities in dependence of Ca²⁺. Mutations of lysine residues in calmodulin binding site 2 strongly reduced calmodulin binding and TRPM3 activity indicating the importance of this domain for TRPM3-mediated Ca²⁺ signaling. Our data show that TRPM3 channels are regulated by intracellular Ca²⁺ and provide the basis for a mechanistic understanding of the regulation of TRPM3 by calmodulin.     

稳定表达“毒性”瞬时受体势A1通道细胞系的建立

瞬时受体势A1 (TRPA1) 是一种对低温敏感的离子通道,除响应温度外,也可被各种刺激性化合物激活,是许多感觉模型的转导通道．建立TRPA1异源表达系统将为药理分析及功能研究提供很大的便利,但是TRPA1的表达会引发细胞毒性,因此构建TRPA1稳定细胞系一直面临着挑战．在人胚肾细胞(HEK-293)中非调控的表达TRPA1稳定细胞系被成功建立．实验证实,培养至25代以上,该细胞系仍持续表达TRPA1,且细胞的功能检测也进一步验证了该重组TRPA1细胞系的稳定性及特异性．TRPA1-HEK细胞系不但是TRPA1功能性分析的便利工具,而且可应用于高通量药物筛选系统,鉴定TRPA1特异性调节剂．     

TRP通道蛋白异源组装的研究进展

TRP通道是一类在神经系统分布广泛的阳离子通道,参与了生物体内许多重要的生理功能,包括感觉信息传递、调节胞内Ca²⁺平衡及发育过程等。近年来的研究发现,TRP通道不仅以同源四聚体形式行使功能,还可以组装成异源四聚体。不同亚基所形成的异源通道具有不同的生物物理学功能和药理学特性,因此TRP通道的组装机理和异源组装通道的功能研究成为该领域的热点而日益得到关注。文章对TRP通道家族中选择性异源组装及组装的分子基础研究的最新现状进行了概述。     

Sub-Ciliary Segregation of Two Drosophila Transient Receptor Potential Channels Begins at the Initial Stage of Their Pre-Ciliary Trafficking

Cilia are important eukaryotic cellular compartments required for diverse biological functions. Recent studies have revealed that protein targeting into the proper ciliary subcompartments is essential for ciliary function. In Drosophila chordotonal cilium, where mechano-electric transduction occurs, two transient receptor potential (TRP) superfamily ion channels, TRPV and TRPN, are restricted to the proximal and distal subcompartments, respectively. To understand the mechanisms underlying the sub-ciliary segregation of the two TRPs, we analyzed their localization under various conditions. In developing chordotonal cilia, TRPN was directly targeted to the ciliary tip from the beginning of its appearance and was retained in the distal subcompartment throughout development, whereas the ciliary localization of TRPV was considerably delayed. Lack of intraflagella transport-related proteins affected TRPV from the initial stage of its pre-ciliary trafficking, whereas it affected TRPN from the ciliary entry stage. The ectopic expression of the two TRP channels in both ciliated and non-ciliated cells revealed their intrinsic properties related to their localization. Taken together, our results suggest that sub-ciliary segregation of the two TRP channels relies on their distinct intrinsic properties, and begins at the initial stage of their pre-ciliary trafficking.     

Neutrophil Elastase Activates Protease-activated Receptor-2 (PAR2) and Transient Receptor Potential Vanilloid 4 (TRPV4) to Cause Inflammation and Pain

Proteases that cleave protease-activated receptor-2 (PAR₂) at Arg³⁶↓Ser³⁷ reveal a tethered ligand that binds to the cleaved receptor. PAR₂ activates transient receptor potential (TRP) channels of nociceptive neurons to induce neurogenic inflammation and pain. Although proteases that cleave PAR₂ at non-canonical sites can trigger distinct signaling cascades, the functional importance of the PAR₂-biased agonism is uncertain. We investigated whether neutrophil elastase, a biased agonist of PAR₂, causes inflammation and pain by activating PAR₂ and TRP vanilloid 4 (TRPV4). Elastase cleaved human PAR₂ at Ala⁶⁶↓Ser⁶⁷ and Ser⁶⁷↓Val⁶⁸_. Elastase stimulated PAR₂-dependent cAMP accumulation and ERK1/2 activation, but not Ca²⁺ mobilization, in KNRK cells. Elastase induced PAR₂ coupling to Gα_s but not Gα_q in HEK293 cells. Although elastase did not promote recruitment of G protein-coupled receptor kinase-2 (GRK2) or β-arrestin to PAR₂, consistent with its inability to promote receptor endocytosis, elastase did stimulate GRK6 recruitment. Elastase caused PAR₂-dependent sensitization of TRPV4 currents in Xenopus laevis oocytes by adenylyl cyclase- and protein kinase A (PKA)-dependent mechanisms. Elastase stimulated PAR₂-dependent cAMP formation and ERK1/2 phosphorylation, and a PAR₂- and TRPV4-mediated influx of extracellular Ca²⁺ in mouse nociceptors. Adenylyl cyclase and PKA-mediated elastase-induced activation of TRPV4 and hyperexcitability of nociceptors. Intraplantar injection of elastase to mice caused edema and mechanical hyperalgesia by PAR₂- and TRPV4-mediated mechanisms. Thus, the elastase-biased agonism of PAR₂ causes Gα_s-dependent activation of adenylyl cyclase and PKA, which activates TRPV4 and sensitizes nociceptors to cause inflammation and pain. Our results identify a novel mechanism of elastase-induced activation of TRPV4 and expand the role of PAR₂ as a mediator of protease-driven inflammation and pain.     

The effects of hydrated C(60) fullerene on gene expression profile of TRPM2 and TRPM7 in hyperhomocysteinemic mice

Abstract

Background: Hyperhomocysteinemia (HHcy) is associated with neurodegenerative diseases. Transient receptor potential melastatin (TRPM2) and TRPM7 channels may be activated by oxidative stress. Hydrated C(60) fullerene (C(60)HyFn) have recently gained considerable attention as promising candidates for neurodegenerative states. We aimed to examine the effects on TRPM2 and TRPM7 gene expression of C(60)HyFn due to marked antioxidant activity in HHcy mice. Methods: C57BL/6 J. mice were divided into four groups: (1) Control group, (2) HHcy, (3) HHcy?+?C(60)HyFn-treated group and (4) C(60)HyFn-treated group. TRPM2 and TRPM7 gene expression in brains of mice were detected by real-time PCR, Western blotting and immunohistochemistry. Apoptosis in brain were assessed by TUNEL staining. Results: mRNA expression levels of TRPM2 were significantly increased in HHcy group compared to the control group. C(60)HyFn administration significantly decreased serum levels of homocysteine and TRPM2 mRNA levels in HHcy?+?C(60)HyFn group. Whereas, HHcy-treatment and C(60)HyFn administration did not change the expression of TRPM7. Conclusion: Administration of C(60)HyFn in HHcy mice significantly reduces serum homocysteine level, neuronal apoptosis and expression level of TRPM2 gene. Increased expression level of TRPM2 induced by oxidative stress might be involved in the ethiopathogenesis of HHcy related neurologic diseases.     

Role of Glutathione-Dependent Peroxidase in Regulation of Lipoperoxide Utilization in Malignant Tumors

Glutathione content, the activity of glutathione-dependent enzymes (glutathione reductase, glutathione peroxidase, and glutathione S-transferase), and also SOD (superoxide dismutase) and catalase were studied in human malignant tumors (uterus, breast, and ovaries) and normal tissues. Glutathione level and the activity of glutathione-dependent enzymes were 2-3 times higher in the malignant tumors than in normal tissues. A negative correlation between the level of glutathione and glutathione-dependent enzymes (glutathione peroxidase and glutathione S-transferase) in tumors and the efficacy of postoperative chemotherapy may characterize the degree of tumor resistance to chemotherapy and therefore may have prognostic value. Low SOD and catalase activity and high activity of glutathione-dependent enzymes in tumors suggest that glutathione peroxidase and glutathione S-transferase play a major role in peroxide utilization in malignant tumors.