Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.
Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Japan.
Tissue Cell. 2023 Jun;82:102093. doi: 10.1016/j.tice.2023.102093. Epub 2023 Apr 15.
Prosaposin is a glycoprotein conserved widely in vertebrates, because it is a precursor for saposins that are required for normal lysosomal function and thus for autophagy, and acts as a neurotrophic factor. Most tetrapods possess two kinds of olfactory neuroepithelia, namely, the olfactory epithelium (OE) and the vomeronasal epithelium (VNE). This study examined the expression patterns of prosaposin and its candidate receptors, G protein-coupled receptor (GPR) 37 and GPR37L1, in mouse OE and VNE by immunofluorescence and in situ hybridization. Prosaposin immunoreactivity was observed in the olfactory receptor neurons, vomeronasal receptor neurons, Bowman's gland (BG), and Jacobson's gland (JG). Prosaposin expression was mainly observed in mature neurons. Prosaposin mRNA expression was observed not only in these cells but also in the apical region of the VNE. GPR37 and GPR37L1 immunoreactivities were found only in the BG and/or the JG. Prosaposin was suggested to secrete and facilitate the autophagic activities of the neurons and modulate the mucus secretion in mouse olfactory organ.
原距蛋白是一种在脊椎动物中广泛保守的糖蛋白，因为它是鞘脂激活蛋白的前体，而鞘脂激活蛋白对于溶酶体的正常功能和自噬至关重要，并且还作为神经营养因子发挥作用。大多数四足动物拥有两种嗅觉上皮，即嗅觉上皮（OE）和犁鼻器上皮（VNE）。本研究通过免疫荧光和原位杂交技术检查了原距蛋白及其候选受体 G 蛋白偶联受体（GPR）37 和 GPR37L1 在小鼠 OE 和 VNE 中的表达模式。原距蛋白免疫反应性在嗅觉受体神经元、犁鼻器受体神经元、Bowman 腺（BG）和 Jacobson 腺（JG）中被观察到。原距蛋白表达主要观察到在成熟神经元中。原距蛋白 mRNA 表达不仅在这些细胞中观察到，而且在 VNE 的顶端区域也观察到。GPR37 和 GPR37L1 免疫反应性仅在 BG 和/或 JG 中被发现。原距蛋白被认为可以分泌并促进神经元的自噬活性，并调节小鼠嗅觉器官中的粘液分泌。
