Department of Anatomy, The Nippon Dental University School of Life Dentistry at Tokyo, Tokyo, Japan.
Department of Anatomy, The Nippon Dental University School of Life Dentistry at Tokyo, Tokyo, Japan.
Ann Anat. 2023 Jan;245:152017. doi: 10.1016/j.aanat.2022.152017. Epub 2022 Oct 21.
The mammalian tongue is a highly specialized muscular organ. The Wnt5a ligand regulates muscle development by mediating the activation of several noncanonical Wnt signaling pathways in a receptor context-dependent fashion. However, there is poor information on the expression and behavior of Wnt5a proteins during muscle development of the embryonic tongue.
The spatiotemporal distribution profiles of the Wnt5a ligand and its receptors, receptor tyrosine kinase-like orphan receptor 2 (Ror2), Frizzled2 (Fzd2), and Frizzled5 (Fzd5), in the developing tongue muscles of prenatal mice from embryonic day 12.5-18.5 were analyzed using immunofluorescence (IF) double staining of a target protein and desmin, a marker protein of myogenic cells. Immunolabeling images were subjected to digital detection analysis using the WinROOF 2018 version 4.19.0 image processing software when needed.
IF signals of the Wnt5a ligand protein and its receptors Ror2 and Fzd2 were detected in developing myoblasts and myotubes of the embryonic tongue, but they were undetectable in mature myofibers equipped with sarcomere structures. Fzd2 expression was specific for desmin-positive developing muscle cells, whereas those of Ror2 and the Wnt5a ligand were widespread and nonselective for desmin-positive cells and that of Fzd5 was predominant in desmin-negative cells of the epithelium and subepithelial mesenchyme.
Developing muscle cells but not mature myofibers of the mouse embryonic tongue express the Wnt5a ligand and its receptors Ror2 and Fzd2, which may mediate Wnt5a signaling in the development processes of tongue muscle fibers.
哺乳动物的舌头是一种高度特化的肌肉器官。Wnt5a 配体通过受体上下文依赖性方式调节几种非经典 Wnt 信号通路的激活来调节肌肉发育。然而，关于 Wnt5a 蛋白在胚胎舌肌肉发育过程中的表达和行为知之甚少。
使用免疫荧光（IF）双重染色目标蛋白和肌球蛋白细胞标志物肌动蛋白，分析了从胚胎第 12.5 天至 18.5 天的产前小鼠发育中的舌肌肉中 Wnt5a 配体及其受体、受体酪氨酸激酶样孤儿受体 2（Ror2）、Frizzled2（Fzd2）和 Frizzled5（Fzd5）的时空分布谱。当需要时，使用 WinROOF 2018 版本 4.19.0 图像处理软件对免疫标记图像进行数字检测分析。
IF 信号检测到 Wnt5a 配体蛋白及其受体 Ror2 和 Fzd2 存在于发育中的胚胎舌原代成肌细胞和成肌纤维中，但在具有肌节结构的成熟肌纤维中检测不到。Fzd2 表达特异性地用于肌球蛋白阳性发育中的肌肉细胞，而 Ror2 和 Wnt5a 配体的表达则广泛且非选择性地用于肌球蛋白阳性细胞，而 Fzd5 的表达则主要存在于上皮和上皮下间充质中的肌球蛋白阴性细胞中。
发育中的肌肉细胞而不是成熟的小鼠胚胎舌肌纤维表达 Wnt5a 配体及其受体 Ror2 和 Fzd2，这可能介导了舌肌纤维发育过程中的 Wnt5a 信号传导。
