Changes in the number of Merkel cells with hair cycle in discs in the back of rats

大鼠背部椎间盘默克尔细胞数量随毛发周期的变化

• 批准号: 14570811
• 负责人: NARISAWA Yutaka
• 金额: $ 1.92万
• 依托单位: Saga University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570811/
• 关键词: Merkel cell; hair follicle; hair disc; hair cycle; 毛嚢; 幹細胞; ラット; 表皮シート; 抜毛

There are many unclear propblems in the embryological origin, differentiation and function of Merkel cells. The hair disc is an important research target of functional analysis of Merkel cells because relatively many Merkel cells are present in hair discs. It has been well known that hair follicle, as well as many Merkel cells, are also important elements constituting hair discs.Hair follicles undergo a unique cyclic change. Mechanism of anagen, catagen, and telogen in the hair, cycle in hair follicles has not been elucidated. Interestingly, it has been reported that the population of Merkel cells in hair discs were related to the hair cycle in mice. In this study, we present an obvious evidence of the hair cycle dependency of Merkel cell population in hair discs of normal mice and rat skin.Hair was depilated from the back in mice, and epidermal sheets were prepared on days 0,1,3,5,8,12,17, and 18 after depilation to investigate changes in the number of Merkel cells with the hair cycle … More in three dimensions. The number of Merkel cells changed with the hair cycle.Next, we three-dimensionally observed time-course changes in the number of Merkel cells in hair discs starting in the embryonic period. Using rat back skin, changes in the number of Merkel cells during the morphogenesis of hair discs and later hair cycle were investigated. Epidermal sheets of rat back skin were prepared fom the 18th embryonic day till day 100 after birth. During the first hair cycle, which is the developmental step of hair follicle morphogenesis, and the second and third cycles, which are regeneration of the hair follicles, Merkel cells in hair discs increased during the early, to middle phase of anagen and decreased during the middle phase of anagen to catagen and telogen in embryos and after birth. These three-dimensional findings clearly demonstrated that the Merkel cell distribution in hair discs changes with the hair cycle.Moreover, morphological variation of Merkel cells, oval and dendritic cell types, at the light microscopic level has been reported. The time-course frequencies of the two types were three-dimensionally investigated, respectively. The number of "oval cell type. Merkel cells was 5.6 per hair disc, being not markedly affected by the hair cycle. In contrast, the number of dendritic cell type Merkel cells markedly changed with the hair cycle, This difference between oval and dendritic cell type Merkel cells may suggest some functional differences of two types such as some kinds of secretory function related to the hair cycle. Less

默克尔细胞的胚胎起源、分化和功能等方面仍有许多不清楚的地方。毛盘是默克尔细胞功能分析的重要研究对象，因为相对多的默克尔细胞存在于毛盘中。众所周知，毛囊和许多默克尔细胞一样，也是构成毛盘的重要组成部分。毛发生长期、退行期和休止期、毛囊周期的机制尚未阐明。有趣的是，有报道称，小鼠毛盘中的默克尔细胞群与毛发周期有关。在本研究中，我们从正常小鼠和大鼠皮肤的毛盘中提出了一个明显的证据，即默克尔细胞群体的毛周期依赖性，从小鼠背部脱毛，并在脱毛后0，1，3，5，8，12，17和18天制备表皮片，以研究默克尔细胞数量随毛周期的变化 ...更多信息 在三维空间中。默克尔细胞的数量随着毛发周期的变化而变化。接下来，我们从胚胎期开始，三维观察了毛盘中默克尔细胞数量的时程变化。以大鼠背部皮肤为材料，研究了毛盘形态发生过程中默克尔细胞数量的变化及毛周期的后期变化。取胚胎第18天至生后第100天的大鼠背部皮肤，制备表皮片。在毛囊形态发生的第一周期和毛囊再生的第二、第三周期中，毛盘中的默克尔细胞在胚胎和出生后的生长期早期至中期增加，在生长期中期至退化期和休止期减少。这些三维结构的观察结果清楚地表明，默克尔细胞在毛盘中的分布随毛发周期的变化而变化。此外，默克尔细胞的形态变化，卵圆形和树突状细胞类型已在光镜水平上的报告。分别对两种类型的时程频率进行了三维研究。卵圆形细胞型的数量。默克尔细胞数为5.6个/毛盘，不受毛发周期的显著影响。而树突状细胞型默克尔细胞的数量则随毛发周期的变化而变化。卵圆型和树突状细胞型默克尔细胞之间的这种差异可能反映了两种细胞在某些功能上的差异，如与毛发周期有关的某些分泌功能。少