TRPC通道参与疼痛信号传递过程与作用机制的研究进展

<正>瞬时受体电位通道(transient receptor potential,TRP)家族是一类六次跨膜的非选择性阳离子通道,主要包括TRPC、TRPA、TRPM、TRPV、TRPP和TRPML六个亚家族。近年来越来越多的实验证据表明TRP通道是痛觉信息传递系统的"前沿哨兵",响应细胞及机体内外伤害性热、冷、机械和化学等刺激,并将其转换为动作电位向脊髓及上位脑中枢传递最终产生痛感觉~([1,2])。其中哺乳动物TRPC通道家族的七个成员     

TRPV1通道蛋白介导的生理病理机制

瞬时感受器电位离子通道蛋白(transient receptor potentialion dannel protein,TRP)是一类组织分布非常广泛的非选择性阳离子通道蛋白。到目前为止,有超过30个TRP通道家族成员在哺乳动物中先后被克隆。TRPV1是近年研究较多、机制较为清楚的TRPV亚家族成员之一,主要分布于外周感觉神经。研究表明,TRPV1通道蛋白可被多种外源或内源性介质敏化或激活,其主要生理功能是感受热、痛等伤害性刺激,且与炎症、咳嗽等多种病理过程密切相关。     

TRPV4在心血管疾病中作用的研究进展

<正>瞬时受体电位阳离子通道V亚家族成员4(tran-sientreceptorpotentialcationchannelsubfamilyV member4,TRPV4)是瞬时受体电位阳离子通道(transient receptor potential cation channel, TRP)家族成员，是一种非选择性阳离子通道，对Ca²⁺离子具有适中通透性，对Na⁺和Mg²⁺少量通透(P_Ca/P_Na约为6～10,P_Ca/P_Mg约为2～3)。TRPV4在心血管系统表达广泛，主要表达于血管内皮细胞、血管平滑肌细胞、心肌细胞和成纤维细胞等，可调节血管张力和血管通透性，参与机械信号传导等。     

机械感觉相关的TRP通道研究进展

瞬时受体电位通道(transient receptor potential channels,TRP channels)是一类六次跨膜的非选择性阳离子通道,与经典离子通道主要受膜电位或配体的激活不同,TRP通道可受渗透压、pH值、机械力、配体以及细胞内信号分子等多种因素的激活,进而参与体内多种生理和病理过程,如感受痛、热等伤害刺激以及参与炎症等病理过程。近来较多的证据提示TRP通道在机械感觉中尤其有重要作用。本文对机械感觉功能相关的TRP通道,尤其是与听觉相关的TRP通道的研究进展进行综述,分析可能的激活和调控机制并展望其未来的发展方向。     

中枢神经系统内的TRPC6离子通道

<正>TRPC6是TRP(transient receptor potential,TRP)基因超家族C亚家族(canonical)的成员之一,编码钙可通透的非选择性阳离子通道[1,2]。十余年来的研究证明TRPC6分子参与动物体内许多重要的生理和病理调节过程,如血管与气道平滑肌收缩、肾小球滤过膜滤过功能、免疫和血液细胞调节等[3];该分子功能异常会导致高血压和局灶性节段性肾小球硬化[4,5]。     

TRPM7与乳腺癌的研究进展

瞬时受体电位(transient receptor potential,TRP)通道是一种非选择性阳离子通道超级家族.作为TRPM亚家族的一员,TRPM7因其独特的丝氨酸/苏氨酸激酶结构、广泛的分布以及多样的生理功能而引起了关注.众多研究结果表明:TRPM7通道的表达或功能异常与乳腺癌的发生及发展密切相关.目前,转移性乳腺癌不可被治愈,是导致乳腺癌患者死亡的主要原因.     

TRPV1阻断剂的研究进展

瞬时感受器电位香草酸受体1(TRPV1)是瞬时感受器电位（transient receptor potential,TRP)的非选择性阳离子通道蛋白家族成员之一，主要表达在初级传入感觉神经元上，是一种非选择性的阳离子通道。该受体可探测和整合诱发痛觉的化学和热刺激信号，主要有辣椒素（红辣椒的辛辣成分），伤害性热（>43℃）和质子等。它可将化学、机械和热刺激信号转化为动作电位，并将这些信息上传到中枢，最后使机体产生痛觉或不舒服的感受。近年来，TRPV1通道蛋白已成为开发新的镇痛药物的重要靶点。     

姜黄素对TRP离子通道抑制作用的研究

目的验证瞬时受体电位（TRP）通道在胶质瘤MGR2细胞中的存在,研究姜黄素对TRP通道的电生理影响,探讨姜黄素抑制肿瘤细胞增殖的可能机制。方法体外培养人脑胶质瘤细胞MGR2;利用膜片钳技术检测胶质瘤细胞MGR2的电生理特性,验证并分离TRP离子通道。使用薄荷醇、无Mg2＋内液、酸以及非特异阻断剂2-氨基乙氧基苯硼酸（2-APB）及钆离子（Gd3＋）对TRP通道的敏感性进行检测。记录不同浓度的姜黄素对TRP通道电流幅度的影响。结果神经胶质瘤细胞MGR2是一种非可兴奋细胞,其细胞上表现出TRP离子通道的电生理特性。该通道对薄荷醇不敏感,对酸的反应不明显。对细胞内液低Mg2＋有（24.2±4.1）%的TRP电流增加（n=12,P〈0.05）,200μmol/L2-APB及10μmol/LGd3＋对TRP电流分别有（46.4±4.5）%及（73.2±3.6）%的增加（n=12,P〈0.05）。姜黄素对TRP通道的抑制作用具有浓度依赖性和可恢复性。结论 TRP通道在胶质瘤细胞MGR2中存在,姜黄素对TRP通道的作用具有浓度依赖性,为姜黄素抑制肿瘤增殖的可能机制提供了实验依据。     

瞬时感受器电位V亚家族离子通道——温度感受器

生物体可以感受广泛的温度范围,其中温度超过43℃或低于15℃还可引起伤害性痛觉。近年来在哺乳动物中已经发现6个与温度有关的通道,其中4个属于瞬时感受器电位(transient receptor potential,TRP)V亚家族成员。这些通道组织分布非常广泛,功能上属于钙渗透性通道,可被多种理化刺激激活。它们具有不同的温度阈值,并受一些理化因素的调节。     

家族性低丙种球蛋白血症—与α_1-抗胰蛋白酶缺乏连锁遗传

Kirkpatrick等人曾报道家族性低丙种球蛋白血症,特别在家族父系有低IgM作标记。另一研究证明,在患有原发性抗体缺乏的家族,Gm基因表达有定量的缺乏。然而,这些研究都不能阐明遗传的特定方式。本文作者在一个人口众多的家族中,发现一位先证者患有总低丙种球蛋白血症,并患有α_1抗胰蛋白酶缺乏症。因此,作者在这位先证者有亲属关系的7个家庭(包括先证者的父母、父亲的伯伯一家三代、父亲的姑母一家三代和母亲的姑母一家三代等)、31位成员(其中27位是亲属,4位配偶无亲属关系)中,研究了血清免疫球蛋白和蛋白酶抑制剂(Pi)表型,以确定家族性低丙种球蛋     

Regulation of TRP channels by PIP2

Transient receptor potential (TRP) channels are regulated by a wide variety of physical and chemical factors. Recently, several members of the TRP channel family were reported to be regulated by phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P₂, PIP₂). This review will summarize the current knowledge on PIP₂ regulation of TRP channels and discuss the possibility that PIP₂ is a common regulator of mammalian TRP channels.     

Invertebrate TRP proteins as functional models for mammalian channels

Transient receptor potential (TRP) channels constitute a large and diverse family of channel proteins that are expressed in many tissues and cell types in both vertebrates and invertebrates. While the biophysical features of many of the mammalian TRP channels have been described, relatively little is known about their biological roles. Invertebrate TRPs offer valuable genetic handles for characterizing the functions of these cation channels in vivo. Importantly, studies in model organisms can help to identify fundamental mechanisms involved in normal cellular functions and human disease. In this review, we give an overview of the different TRP channels known in the two most utilized invertebrate models, the nematode Caenorhabditis elegans and the fruit-fly Drosophila melanogaster, and discuss briefly the heuristic impact of these invertebrate channels with respect to TRP function in mammals.     

The History of the Drosophila TRP Channel: The Birth of a New Channel Superfamily

Abstract: Transient receptor potential (TRP) channels are polymodal cellular sensors involved in a wide variety of cellular processes, mainly by changing membrane voltage and increasing cellular Ca²⁺. This review outlines in detail the history of the founding member of the TRP family, the Drosophila TRP channel. The field began with a spontaneous mutation in the trp gene that led to a blind mutant during prolonged intense light. It was this mutant that allowed for the discovery of the first TRP channels. A combination of electrophysiological, biochemical, Ca²⁺ measurements, and genetic studies in flies and in other invertebrates pointed to TRP as a novel phosphoinositide-regulated and Ca²⁺-permeable channel. The cloning and sequencing of the trp gene provided its molecular identity. These seminal findings led to the isolation of the first mammalian homologues of the Drosophila TRP channels. We now know that TRP channel proteins are conserved through evolution and are found in most organisms, tissues, and cell-types. The TRP channel superfamily is classified into seven related subfamilies: TRPC, TRPM, TRPV, TRPA, TRPP, TRPML, and TRPN. A great deal is known today about participation of TRP channels in many biological processes, including initiation of pain, thermoregulation, salivary fluid secretion, inflammation, cardiovascular regulation, smooth muscle tone, pressure regulation, Ca²⁺ and Mg²⁺ homeostasis, and lysosomal function. The native Drosophila photoreceptor cells, where the founding member of the TRP channels superfamily was found, is still a useful preparation to study basic features of this remarkable channel.     

New developments in the signaling mechanisms of the store-operated calcium entry pathway

The most ubiquitous pathway for regulated calcium (Ca²⁺) entry into the cells is the store-operated Ca²⁺ (SOC) entry pathway (also called capacitative Ca²⁺ entry) that is conserved from lower organisms such as yeast, worms, and flies to man. The SOC concept was proposed over two decades ago, and SOC channels are defined by their activation in response to depletion of the internal Ca²⁺ stores. Influx through SOC channels is necessary for the replenishment of the Ca²⁺ stores and is also involved in cell signaling to the nucleus. Despite intensive investigations, most of which are focusing on transient receptor potential (TRP) channels as molecular candidates for SOC channels, the mechanisms of activation and the identity of the key molecular players participating in this signaling pathway have long remained elusive. In the last 2–3 years, however, the improvements of RNA silencing protocols combined with high throughput platforms have yielded significant breakthroughs, with the identification of Stim1 as the Ca²⁺ store sensor and Orai1 (CRACM1) as the pore-forming subunit of the archetypical SOC channel, CRAC. This review summarizes the recent advances in the mechanisms of activation of SOC channels and their molecular composition, with emphasis on the roles of Stim, Orai, and TRP proteins.     

Homo- and heteromeric assembly of TRP channel subunits

Mammalian homologues of the Drosophila melanogaster transient receptor potential (TRP) channels are the second largest cation channel family within the superfamily of hexahelical cation channels. Most mammalian TRP channels function as homooligomers and mediate mono- or divalent cation entry upon activation by a variety of stimuli. Because native TRP channels may be multimeric proteins of possibly complex composition, it is difficult to compare cation conductances in native tissues to those of clearly defined homomeric TRP channel complexes in living cells. Therefore, the possibility of heteromeric TRP channel assembly has been investigated in recent years by several groups. As a major conclusion of these studies, most heteromeric TRP channel complexes appear to consist of subunit combinations only within relatively narrow confines of phylogenetic subfamilies. Although the general capability of heteromer formation between closely related TRP channel subunits is now clearly established, we are only beginning to understand whether these heteromeric complexes are of physiological significance. This review summarizes the current knowledge on the promiscuity and specificity of the assembly of channel complexes composed of TRPC-, TRPV- and TRPM-subunits of mammalian TRP channels.     

TRP channels and their implications in metabolic diseases

The transient receptor potential (TRP) channel superfamily is composed of 28 nonselective cation channels that are ubiquitously expressed in many cell types and have considerable functional diversity. Although changes in TRP channel expression and function have been reported in cardiovascular disease and renal disorders, the pathogenic roles of TRP channels in metabolic diseases have not been systemically reviewed. In this review, we summarised the distribution of TRP channels in several metabolic tissues and discussed their roles in mediating and regulating various physiological and pathophysiological metabolic processes and diseases including diabetes, obesity, dyslipidaemia, metabolic syndrome, atherosclerosis, metabolic bone diseases and electrolyte disturbances. This review provides new insight into the involvement of TRP channels in the pathogenesis of metabolic disorders and implicates these channels as potential therapeutic targets for the management of metabolic diseases.     

Human Digital Meissner Corpuscles Display Immunoreactivity for the Multifunctional Ion Channels Trpc6 and Trpv4

Ion channels are at the basis of the sensory processes including mechanosensing. Some members of the transient receptor potential (TRP) ion channel superfamily have been proposed as mechanosensors, but their putative role in mechanotransduction is controversial. Among them there are TRP canonical 6 (TRPC6) and TRP vanilloid 4 (TRPV4) ion channels, which are known to cooperate in mechanical hyperalgesia. Here, we investigated the occurrence, distribution, and possible colocalization of TRPC6 and TRPV4 in human digital Meissner sensory corpuscles using immunohistochemistry and double immunofluorescence (associate with markers for specific corpuscular constituents). TRPC6 immunoreactivity was restricted to the axon of Meissner corpuscles, whereas TRPV4 was detected in the axon but also in the lamellar cells. Moreover, axonal colocalization of TRPV4 and TRPC6 was found in the digital Meissner corpuscles. Present results demonstrate for the first time the occurrence and colocalization of two ion channels candidates to mechanosensors in human cutaneous mechanoreceptors. The functional significance of these ion channels in that place remains to be clarified, but should be related to different properties of mechanosensitivity. Anat Rec, 300:1022–1031, 2017. © 2016 Wiley Periodicals, Inc.     

The use of yeast to understand TRP-channel mechanosensitivity

Mechanosensitive (MS) ion channels likely underlie myriad force-sensing processes, from basic osmotic regulation to specified sensations of animal hearing and touch. Albeit important, the molecular identities of many eukaryotic MS channels remain elusive, let alone their working mechanisms. This is in stark contrast to our advanced knowledge on voltage- or ligand-sensitive channels. Several members of transient receptor potential (TRP) ion channel family have been implicated to function in mechanosensation and are recognized as promising candidate MS channels. The yeast TRP homolog, TRPY1, is clearly a first-line force transducer. It can be activated by hypertonic shock in vivo and by membrane stretch force in excised patches under patch clamp, making it a useful model for understanding TRP channel mechanosensitivity in general. TRPY1 offers two additional research advantages: (1) It has a large (∼300 pS) unitary conductance and therefore a favorable S/N ratio. (2) Budding yeast allows convenient and efficient genetic and molecular manipulations. In this review, we focus on the current research of TRPY1 and discuss its prospect. We also describe the use of yeast as a system to express and characterize animal TRP channels.     

From cardiac cation channels to the molecular dissection of the transient receptor potential channel TRPM4

In 2006, we celebrate not only the milestone paper on the patch-clamp technique [14] but also the publication of the first single-channel measurements in cardiac cells revealing a Ca²⁺-activated, nonselective cation channel [6]. Considerable effort has been undertaken since this time to identify molecular candidates for this class of cation channels that can be found in a variety of tissues. Recent work has shown that this channel is very likely TRPM4, a member of the TRPM ion channel family. The current review links the epochal Colquhoun et al. paper to the detailed molecular knowledge and structure function aspects of this TRP channel. It will be shown that TRPM4 is a Ca²⁺- and voltage-activated channel, which is dramatically modulated by the phospholipid phosphatidyl inositol bisphosphate (PIP₂) and belongs to the heat-activated thermoTRPs. A functional hallmark of TRPM4, as for several TRP channels, is a dramatic shift of its voltage dependence towards negative, physiologically meaningful potentials.     

Renoprotection: focus on TRPV1, TRPV4, TRPC6 and TRPM2

Members of the transient receptor potential (TRP) cation channel receptor family have unique sites of regulatory function in the kidney which enables them to promote regional vasodilatation and controlled Ca²⁺ influx into podocytes and tubular cells. Activated TRP vanilloid 1 receptor channels (TRPV1) have been found to elicit renoprotection in rodent models of acute kidney injury following ischaemia/reperfusion. Transient receptor potential cation channel, subfamily C, member 6 (TRPC6) in podocytes is involved in chronic proteinuric kidney disease, particularly in focal segmental glomerulosclerosis (FSGS). TRP vanilloid 4 receptor channels (TRPV4) are highly expressed in the kidney, where they induce Ca²⁺ influx into endothelial and tubular cells. TRP melastatin (TRPM2) non‐selective cation channels are expressed in the cytoplasm and intracellular organelles, where their inhibition ameliorates ischaemic renal pathology. Although some of their basic properties have been recently identified, the renovascular role of TRPV1, TRPV4, TRPC6 and TRPM2 channels in disease states such as obesity, hypertension and diabetes is largely unknown. In this review, we discuss recent evidence for TRPV1, TRPV4, TRPC6 and TRPM2 serving as potential targets for acute and chronic renoprotection in chronic vascular and metabolic disease.