Gene-expression studies of epidermal Merkel cells

描述(申请人提供)：这项研究的长期目标是以皮肤Merkel细胞-轴突复合体为模型，阐明哺乳动物体感受体细胞机械转导的分子基础。体感机械感受器调节触觉、痛觉和本体感觉。类风湿性关节炎、糖尿病和获得性免疫缺陷综合症等导致周围神经病变的疾病突显了这些感觉对人类健康的重要性。由于周围神经病患者感觉不到伤害，即使是轻微的侮辱也可能导致不可逆转的组织损伤和慢性疼痛。 尽管默克尔细胞在脊椎动物进化过程中是保守的，但它们的功能尚不清楚。默克尔细胞被认为是机械感受器，可以传递压力，并通过突触传递信息到神经系统。或者，默克尔细胞可能通过释放神经调节剂来影响机械感觉神经元的活动。最后，默克尔细胞可能通过影响感觉神经元的神经支配模式，或者通过引导邻近的表皮细胞形成对触摸高度敏感的专门皮肤结构，来影响触摸反应的发展。 这项应用的目的是通过开发分子和体外工具来区分这些拟议的功能。首先，我们将使用小鼠DNA微阵列来鉴定默克尔细胞在皮肤触觉成熟过程中和成熟后的基因表达谱。其次，我们将开发研究分离的Merkel细胞离子通道和神经递质释放的方法。然后，这些体外方法将被用来检查富含默克尔细胞的分子在信号传递中的作用。通过精确定位可能对默克尔细胞信号传递至关重要的分子，这些研究为未来研究这种表皮细胞在触摸接收中的作用以及启动我们对触摸和疼痛的感知的信号奠定了基础。建议的具体目标是： 1.鉴定富含在默克尔细胞中的转录本 2.确定分离的Merkel细胞的离子电导 3.默克尔细胞体外释放神经递质的特征

DESCRIPTION (provided by applicant): The long-term goal of this research is to elucidate the molecular basis of mechanotransduction by mammalian somatosensory receptor cells using the cutaneous Merkel cell-neurite complex as a model. Somatosensory mechanoreceptors mediate the senses of touch, pain and proprioception. The importance of these senses to human health is underscored by diseases that cause peripheral neuropathy such as rheumatoid arthritis, diabetes and acquired immunodeficiency syndrome. Because patients with peripheral neuropathy cannot feel injuries, even minor insults can lead to irreversible tissue damage and chronic pain. Although Merkel cells are conserved throughout vertebrate evolution, their function is unknown. Merkel cells have been proposed to be mechanoreceptors that transduce pressure and convey this information to the nervous system through synaptic transmission. Alternatively, Merkel cells may influence the activity of mechanosensory neurons through the release of neuromodulators. Finally, Merkel cells may affect the development of touch responsiveness, either by influencing the innervation patterns of sensory neurons or by directing neighboring epidermal cells to form specialized skin structures that are highly sensitive to touch. The objective of this application is to distinguish between these proposed functions by developing molecular and in vitro tools. First, we will use mouse DNA microarrays to identify gene-expression profiles of Merkel cells during and after maturation of the sense of cutaneous touch. Second, we will develop methods for studying ion channels and neurotransmitter release in dissociated Merkel cells. These in vitro methods will then be used to examine the roles of Merkel-cell-enriched molecules in signaling. By pinpointing molecules that may be essential for Merkel-cell signaling, these studies lay the groundwork for future investigation of the role of this epidermal cell in touch reception, and of the signals that initiate our perception of touch and pain. The proposed Specific Aims are: 1. Identify transcripts that are enriched in Merkel cells 2. Define the ionic conductances of dissociated Merkel cells 3. Characterize neurotransmitter release from Merkel cells in vitro