ヤマニシ　ハルヨ   Haruyo Yamanishi   山西　治代    所属   川崎医科大学  医学部 基礎医学　解剖学    職種   講師
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Three-dimensional correlative light and focused ion beam scanning electron microscopy reveals the distribution and ultrastructure of lanceolate nerve endings surrounding terminal hair follicles in human scalp skin.
掲載誌名	正式名：Journal of anatomy ISSNコード：14697580/00218782/00218782
掲載区分	国外
巻・号・頁	242,pp.1012-1028
著者・共著者	Yamanishi H, Iwabuchi T
発行年月	2023/06
概要	Lanceolate nerve endings (LNEs) surrounding hair follicles (HFs) play an important role in detecting hair deflection. Complexes of the LNEs form a palisade-like structure along the longitudinal axis of hair roots in which axons are sandwiched between two processes of terminal Schwann cells (tSCs) at the isthmus of HFs. The structure and molecular mechanism of LNEs in animal sinus hair, pelage, and human vellus hairs have been investigated. Despite the high density of HFs in human scalp skin, the LNEs in human terminal HFs have not been investigated. In this study, we aimed to reveal the distribution and ultrastructure of LNEs in terminal HFs of human scalp skin. Using light-sheet microscopy and immunostaining, the LNEs were observed at one terminal HF but not at the other terminal HFs in the same follicular unit. The ultrastructure of the LNEs of terminal HFs in human scalp skin was characterized using correlated light and electron microscopy (CLEM). Confocal laser microscopy and transmission electron microscopy of serial transverse sections of HFs revealed that LNEs were aligned adjacent to the basal lamina outside the outer root sheath (ORS), at the isthmus of terminal HFs, and adjacent to CD200-positive ORS cells in the upper bulge region. Moreover, axons with abundant mitochondria were sandwiched between tSCs. Three-dimensional CLEM, specifically confocal laser microscopy and focused ion beam scanning electron microscopy, of stained serial transverse sections revealed that LNEs were wrapped with type I and type II tSCs, with the processes protruding from the space between the Schwann cells. Moreover, the ultrastructures of LNEs at miniaturized HFs were similar to those of LNEs at terminal HFs. Preembedding immunoelectron microscopy revealed that Piezo-type mechanosensitive ion channel component 2 (Piezo2), a gated ion channel, was in axons and tSCs and adjacent to the cell membrane of axons and tSCs, suggesting that LNEs function as mechanosensors. The number of