Wong Yi Li, Okubo Toru, Uno Eiko, Suda Kazuma, Ishii Tsuyoshi
Basic Research Development Division, Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa, Kyoto, 619-0216, Japan.
Basic Research Development Division, Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa, Kyoto, 619-0216, Japan.
Biochem Biophys Res Commun. 2022 May 28;606:108-113. doi: 10.1016/j.bbrc.2022.03.087. Epub 2022 Mar 18.
CD99 is a glycoprotein primarily expressed in immune cells. Physiologically, it is involved in the adhesion, migration, and development of immune cells. The presence of CD99 in the skin was first reported in 2016 and its function is yet to be determined. In this study, we aimed to understand the role of CD99 in the skin using normal human epidermal keratinocytes (NHEK). CD99 expression increased with the confluency of NHEK, while the CD99-high expressing NHEK lost their stem cell properties and played a role in barrier function. We characterized CD99-expressing NHEK as cells committed to early differentiation because they expressed early differentiation markers. However, the deficiency of CD99 in NHEK disrupted homeostasis and caused aberrant differentiation, as evidenced by larger cells with lesser Ki67 staining and higher expression of terminal differentiation markers. Hence, we propose that CD99 is involved in maintaining homeostasis and initiating early differentiation in the skin.
CD99是一种主要在免疫细胞中表达的糖蛋白。在生理状态下，它参与免疫细胞的黏附、迁移和发育。2016年首次报道了皮肤中存在CD99，其功能尚待确定。在本研究中，我们旨在利用正常人表皮角质形成细胞（NHEK）了解CD99在皮肤中的作用。CD99的表达随着NHEK的汇合而增加，而高表达CD99的NHEK失去了其干细胞特性并在屏障功能中发挥作用。我们将表达CD99的NHEK表征为致力于早期分化的细胞，因为它们表达早期分化标志物。然而，NHEK中CD99的缺乏破坏了稳态并导致异常分化，表现为细胞更大、Ki67染色更少以及终末分化标志物表达更高。因此，我们提出CD99参与维持皮肤的稳态并启动早期分化。
