Department of Biology, University of Washington, Seattle, United States.
Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, United States.
Elife. 2019 Mar 11;8:e42455. doi: 10.7554/eLife.42455.
Interactions between epithelial cells and neurons influence a range of sensory modalities including taste, touch, and smell. Vertebrate and invertebrate epidermal cells ensheath peripheral arbors of somatosensory neurons, including nociceptors, yet the developmental origins and functional roles of this ensheathment are largely unknown. Here, we describe an evolutionarily conserved morphogenetic mechanism for epidermal ensheathment of somatosensory neurites. We found that somatosensory neurons in and zebrafish induce formation of epidermal sheaths, which wrap neurites of different types of neurons to different extents. Neurites induce formation of plasma membrane phosphatidylinositol 4,5-bisphosphate microdomains at nascent sheaths, followed by a filamentous actin network, and recruitment of junctional proteins that likely form autotypic junctions to seal sheaths. Finally, blocking epidermal sheath formation destabilized dendrite branches and reduced nociceptive sensitivity in . Epidermal somatosensory neurite ensheathment is thus a deeply conserved cellular process that contributes to the morphogenesis and function of nociceptive sensory neurons.
上皮细胞和神经元之间的相互作用影响多种感觉模式，包括味觉、触觉和嗅觉。脊椎动物和无脊椎动物的表皮细胞包裹躯体感觉神经元的周围树突，包括伤害感受器，但这种包裹的发育起源和功能作用在很大程度上尚不清楚。在这里，我们描述了一种表皮包裹躯体感觉神经突的进化保守的形态发生机制。我们发现，和斑马鱼中的躯体感觉神经元诱导表皮鞘的形成，这种鞘以不同的程度包裹不同类型神经元的神经突。神经突在新生鞘处诱导形成质膜磷脂酰肌醇 4,5-二磷酸微域，随后是丝状肌动蛋白网络的形成，并募集可能形成自体连接的连接蛋白，以封闭鞘。最后，阻断表皮鞘的形成会使树突分支不稳定，并降低 的伤害感受敏感性。因此，表皮躯体感觉神经突的包裹是一种深度保守的细胞过程，有助于伤害感受感觉神经元的形态发生和功能。
