SULFATED STEROIDS AS NATURAL LIGANDS OF MOUSE PHEROMONE-SENSING NEURONS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 在小鼠中，信息素和其他社会气味线索传达有关性别，社会地位和身份的信息;然而，这些线索的分子本质本质基本上是未知的。为了确定这些线索，我们筛选了雌性小鼠尿液的色谱组分，其能力，导致可重复的发射率增加的信息素检测犁鼻感觉神经元（VSN）使用多电极阵列（MEA）记录。发现活性化合物在其基本性质上是非常均匀的，大多数具有低分子量、中等疏水性、低挥发性和负电荷。活性化合物的纯化和结构分析揭示了多种硫酸化类固醇，其中两种被鉴定为硫酸化糖皮质激素，包括皮质酮21-硫酸酯。硫酸酯酶处理的尿提取物失去>80%的活性，表明硫酸化化合物是雌性小鼠尿中主要的VSN配体。通过MEA记录测量，31种合成硫酸化类固醇的集合比包含大多数先前报道的所有VSN配体的类似大小的刺激集更频繁地触发响应30倍。总的来说，VSNs检测到所有主要类别的硫酸化类固醇，但个别神经元对化学结构的微小变化敏感。来自男性和女性的VSN检测到硫酸化类固醇，但感觉转导通道TRPC 2的敲除没有检测到这些化合物。在应激动物中，两种硫酸化糖皮质激素的尿液浓度增加了许多倍，这表明有关生理状态的信息是由特定硫酸化类固醇的尿液浓度编码的。这些结果为小鼠之间的化学通讯提供了前所未有的信号特征。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Among mice, pheromones and other social odor cues convey information about sex, social status, and identity; however, the molecular nature of these cues is essentially unknown. To identify these cues, we screened chromatographic fractions of female mouse urine for their ability to cause reproducible firing rate increases in the pheromone-detecting vomeronasal sensory neurons (VSNs) using multielectrode array (MEA) recording. Active compounds were found to be remarkably homogenous in their basic properties, with most being of low molecular weight, moderate hydrophobicity, low volatility, and possessing a negative electric charge. Purification and structural analysis of active compounds revealed multiple sulfated steroids, of which two were identified as sulfated glucocorticoids, including corticosterone 21-sulfate. Sulfatase-treated urine extracts lost >80% of their activity, indicating that sulfated compounds are the predominant VSN ligands in female mouse urine. As measured by MEA recording, a collection of 31 synthetic sulfated steroids triggered responses 30-fold more frequently than did a similarly sized stimulus set containing the majority of all previously reported VSN ligands. Collectively, VSNs detected all major classes of sulfated steroids, but individual neurons were sensitive to small variations in chemical structure. VSNs from both males and females detected sulfated steroids, but knock-outs for the sensory transduction channel TRPC2 did not detect these compounds. Urine concentrations of the two sulfated glucocorticoids increased many fold in stressed animals, indicating that information about physiological status is encoded by the urine concentration of particular sulfated steroids. These results provide an unprecedented characterization of the signals available for chemical communication among mice.