Ishida Kentaro, Saito Tetsuichiro, Mitsui Toshiyuki
Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan.
Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Dev Growth Differ. 2019 Feb;61(2):141-149. doi: 10.1111/dgd.12593. Epub 2019 Jan 24.
Selective cell death by apoptosis plays important roles in organogenesis. Apoptotic cells are observed in the developmental and homeostatic processes of several ectodermal organs, such as hairs, feathers, and mammary glands. In chick feather development, apoptotic events have been observed during feather morphogenesis, but have not been investigated during early feather bud formation. Previously, we have reported a method for generating feather buds on a bioengineered skin from dissociated skin epithelial and mesenchymal cells in three-dimensional culture. During the development of the bioengineered skin, epithelial cavity formation by apoptosis was observed in the epithelial tissue. In this study, we examined the selective epithelial cell death during the bioengineered skin development. Histological analyses suggest that the selective epithelial cell death in the bioengineered skin was induced by caspase-3-related apoptosis. The formation of feather buds of the bioengineered skin was disturbed by the treatment with a pan-caspase inhibitor. The pan-caspase inhibitor treatment suppressed the rearrangement of the epithelial layer and the formation of dermal condensation, which are thought to be essential step to form feather buds. The suppression of the formation of feather buds on the pan-caspase inhibitor-treated skin was partially compensated by the addition of a GSK-3β inhibitor, which activates Wnt/β-catenin signaling. These results suggest that the epithelial cell death is involved in the formation of feather buds of the bioengineered skin. These observations also suggest that caspase activities and Wnt/β-catenin signaling may contribute to the formation of epithelial and mesenchymal components in the bioengineered skin.
凋亡介导的选择性细胞死亡在器官发生过程中发挥着重要作用。在毛发、羽毛和乳腺等几种外胚层器官的发育和稳态过程中可观察到凋亡细胞。在鸡羽毛发育过程中，已在羽毛形态发生期间观察到凋亡事件，但在早期羽毛芽形成过程中尚未进行研究。此前，我们报道了一种在三维培养中从解离的皮肤上皮细胞和间充质细胞在生物工程皮肤中生成羽毛芽的方法。在生物工程皮肤发育过程中，在上皮组织中观察到通过凋亡形成上皮腔。在本研究中，我们检查了生物工程皮肤发育过程中的选择性上皮细胞死亡。组织学分析表明，生物工程皮肤中的选择性上皮细胞死亡是由caspase-3相关凋亡诱导的。用泛caspase抑制剂处理会干扰生物工程皮肤羽毛芽的形成。泛caspase抑制剂处理抑制了上皮层的重排和真皮凝聚的形成，而这被认为是形成羽毛芽的关键步骤。在泛caspase抑制剂处理的皮肤上，通过添加激活Wnt/β-连环蛋白信号的GSK-3β抑制剂，可部分补偿羽毛芽形成的抑制。这些结果表明，上皮细胞死亡参与了生物工程皮肤羽毛芽的形成。这些观察结果还表明，caspase活性和Wnt/β-连环蛋白信号可能有助于生物工程皮肤中上皮和间充质成分的形成。
