Páez Omar, Segura-Chama Pedro, Almanza Angélica, Pellicer Francisco, Mercado Francisco
Laboratorio de Fisiología Celular, Dirección de Investigaciones en Nuerociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.
Cátedras CONACyT, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.
Front Physiol. 2021 Oct 26;12:733267. doi: 10.3389/fphys.2021.733267. eCollection 2021.
Pain by chemical irritants is one of the less well-described aspects of nociception. The acidic substance is the paradigm of the chemical noxious compound. An acidic insult on cutaneous, subcutaneous and muscle tissue results in pain sensation. Acid (or H) has at least two main receptor channels in dorsal root ganglia (DRG) nociceptors: the heat receptor transient receptor potential vanilloid 1 (TRPV1) and the acid-sensing ionic channels (ASICs). TRPV1 is a low-sensitivity H receptor, whereas ASIC channels display a higher H sensitivity of at least one order of magnitude. In this review, we first describe the functional and structural characteristics of these and other H-receptor candidates and the biophysics of their responses to low pH. Additionally, we compile reports of the expression of these H-receptors (and other possible complementary proteins) within the DRG and compare these data with mRNA expression profiles from single-cell sequencing datasets for ASIC3, ASIC1, transient receptor potential Ankiryn subtype 1 (TRPA1) and TRPV1. We show that few nociceptor subpopulations (discriminated by unbiased classifications) combine acid-sensitive channels. This comparative review is presented in light of the accumulating evidence for labeled-line coding for most noxious sensory stimuli.
化学刺激物引起的疼痛是伤害感受中描述较少的方面之一。酸性物质是化学性有害化合物的典型代表。对皮肤、皮下组织和肌肉组织的酸性刺激会导致疼痛感觉。酸（或氢离子）在背根神经节（DRG）伤害感受器中至少有两个主要受体通道：热受体瞬时受体电位香草酸受体1（TRPV1）和酸敏感离子通道（ASICs）。TRPV1是一种低敏感性氢离子受体，而ASIC通道对氢离子的敏感性至少高一个数量级。在本综述中，我们首先描述这些以及其他氢离子受体候选物的功能和结构特征，以及它们对低pH值反应的生物物理学特性。此外，我们汇总了这些氢离子受体（以及其他可能的互补蛋白）在DRG内的表达报告，并将这些数据与来自单细胞测序数据集的ASIC3、ASIC1、瞬时受体电位锚蛋白亚型1（TRPA1）和TRPV1的mRNA表达谱进行比较。我们发现，很少有伤害感受器亚群（通过无偏分类区分）同时表达酸敏感通道。鉴于越来越多的证据表明大多数有害感觉刺激存在标记线编码，我们进行了这一比较性综述。
