Staaf Susanne, Franck Marina C M, Marmigère Frédéric, Mattsson Jan P, Ernfors Patrik
Department of Bioscience, AstraZeneca R&D Mölndal, 431 83 Mölndal, Sweden.
Gene Expr Patterns. 2010 Jan;10(1):65-74. doi: 10.1016/j.gep.2009.10.003. Epub 2009 Oct 20.
Despite the significance of transient receptor potential (TRP) channels in sensory physiology, little is known of the expression and developmental regulation of the TRPM (melastatin) subgroup in sensory neurons. In order to find out if the eight TRPM subgroup members (TRPM1-TRPM8) have a possible role in the sensory nervous system, we characterized the developmental regulation of their expression in mouse dorsal root ganglion (DRG) from embryonic (E) day 12 to adulthood. Transcripts for all channels except for TRPM1 were detected in lumbar and thoracic DRG and in nodose ganglion (NG) with distinguishable expression patterns from E12 until adult. For most channels, the expression increased from E14 to adult with the exception of TRPM5, which displayed transient high levels during embryonic and early postnatal stages. Cellular localization of TRPM8 mRNA was found only in a limited subset of very small diameter neurons distinct in size from other populations. These neurons did not bind isolectin B4 (IB4) and expressed neither the neuropeptide calcitonin gene-related peptide (CGRP) nor neurofilament (NF)200. This suggests that TRPM8(+) thermoreceptive sensory neurons fall into a separate group of very small sized neurons distinct from peptidergic and IB4(+) subtypes of sensory neurons. Our results, showing the expression and dynamic regulation of TRPM channels during development, indicate that many TRPM subfamily members could participate during nervous system development and in the adult by determining distinct physiological properties of sensory neurons.
尽管瞬时受体电位（TRP）通道在感觉生理学中具有重要意义，但对于TRPM（褪黑素）亚组在感觉神经元中的表达和发育调控却知之甚少。为了探究TRPM亚组的八个成员（TRPM1 - TRPM8）在感觉神经系统中是否具有潜在作用，我们对它们在小鼠背根神经节（DRG）从胚胎期（E）第12天到成年期的表达发育调控进行了表征。除TRPM1外，所有通道的转录本在腰段和胸段DRG以及结状神经节（NG）中均有检测到，从E12直至成年，其表达模式具有明显差异。对于大多数通道，其表达从E14到成年期增加，但TRPM5除外，它在胚胎期和出生后早期阶段呈现短暂的高水平表达。仅在一小部分直径非常小的神经元中发现了TRPM8 mRNA的细胞定位，这些神经元在大小上与其他群体不同。这些神经元不结合异凝集素B4（IB4），既不表达神经肽降钙素基因相关肽（CGRP）也不表达神经丝（NF）200。这表明TRPM8（+）热感受性感觉神经元属于一类与肽能和IB4（+）感觉神经元亚型不同的非常小的神经元群体。我们的结果显示了TRPM通道在发育过程中的表达和动态调控，表明许多TRPM亚家族成员可能通过决定感觉神经元的不同生理特性，在神经系统发育过程中和成年期发挥作用。
