目前,所有唾液导管(插层,条纹和收集)被假定以类似的方式广泛地发挥作用,回收分泌腺泡细胞分泌的离子,同时保留液体量并将唾液输送到口腔。然而,对不同类型的涎管细胞之间的结构和功能差异的研究很少。因此,在这项研究中,参与刺激-分泌偶联的蛋白质的表达谱,以及插层导管(ID)和横纹导管细胞的功能,被检查过。特别关注定义不同导管细胞群体之间的差异。要做到这一点,免疫组织化学和原位杂交用于检查与离子和液体的重吸收和分泌有关的蛋白质的定位和表达。Further,体内钙成像用于研究细胞功能。根据蛋白质表达谱和功能数据,观察到ID和横纹导管之间存在明显差异。具体来说,ID细胞表达分泌腺泡细胞天然的蛋白质,同时缺乏在横纹导管中特异性表达的蛋白质。Further,ID和横纹导管细胞显示不同的钙信号特征,ID以类似腺泡细胞的方式响应神经刺激。总的来说,我们的数据表明,IDs在分泌过程中具有独特的作用,与再吸收的横纹管道分开。相反,根据我们的证据,ID表达在分泌细胞中发现的蛋白质,以类似腺泡细胞的方式产生钙信号,and,因此,很可能是分泌细胞.关键点:目前检查唾液插入导管细胞的研究是有限的,与最小的文件的离子传输机械和细胞在流体生成的整体作用。唾液插入的导管细胞被认为以与其他导管细胞相同的方式起作用,回收离子,维持流体体积并将最终唾液递送至口腔。在这里,我们使用免疫组织化学系统地检查唾液插入导管细胞的结构和功能,原位杂交和通过监测体内Ca2+动力学。结构数据显示,插入的导管细胞缺乏对重吸收至关重要的蛋白质,并表达分泌所需的蛋白质。插层导管细胞中的Ca2动力学与分泌细胞中观察到的一致,这是由GPCR介导的IP3产生引起的。
Currently, all salivary ducts (intercalated, striated and collecting) are assumed to function broadly in a similar manner, reclaiming ions that were secreted by the secretory acinar cells while preserving fluid volume and delivering saliva to the oral cavity. Nevertheless, there has been minimal investigation into the structural and functional differences between distinct types of salivary duct cells. Therefore, in this study, the expression profile of proteins involved in stimulus-secretion coupling, as well as the function of the intercalated duct (ID) and striated duct cells, was examined. Particular focus was placed on defining differences between distinct duct cell populations. To accomplish this, immunohistochemistry and in situ hybridization were utilized to examine the localization and expression of proteins involved in reabsorption and secretion of ions and fluid. Further, in vivo calcium imaging was employed to investigate cellular function. Based on the protein expression profile and functional data, marked differences between the IDs and striated ducts were observed. Specifically, the ID cells express proteins native to the secretory acinar cells while lacking proteins specifically expressed in the striated ducts. Further, the ID and striated duct cells display different calcium signalling characteristics, with the IDs responding to a neural stimulus in a manner similar to the acinar cells. Overall, our data suggest that the IDs have a distinct role in the secretory process, separate from the reabsorptive striated ducts. Instead, based on our evidence, the IDs express proteins found in secretory cells, generate calcium signals in a manner similar to acinar cells, and, therefore, are likely secretory cells. KEY POINTS: Current studies examining salivary intercalated duct cells are limited, with minimal documentation of the ion transport machinery and the overall role of the cells in fluid generation. Salivary intercalated duct cells are presumed to function in the same manner as other duct cells, reclaiming ions, maintaining fluid volume and delivering the final saliva to the oral cavity. Here we systematically examine the structure and function of the salivary intercalated duct cells using immunohistochemistry, in situ hybridization and by monitoring in vivo Ca2+ dynamics. Structural data revealed that the intercalated duct cells lack proteins vital for reabsorption and express proteins necessary for secretion. Ca2+ dynamics in the intercalated duct cells were consistent with those observed in secretory cells and resulted from GPCR-mediated IP3 production.