Vannucchi Maria-Giuliana, Faussone-Pellegrini Maria-Simonetta
Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Viale Pieraccini 6, Florence, 50134, Italy.
Adv Exp Med Biol. 2016;913:115-126. doi: 10.1007/978-981-10-1061-3_7.
Several cells are endowed in the interstitial space of the connective tissue; among them, a peculiar type has been recently described and named telocyte (TC). The increasing interest on this cell type has allowed identifying it in almost all the organs. All TCs have a proper ultrastructural feature that makes them undoubtedly recognizable under the transmission electron microscope (TEM). On the contrary, a complex often confusing picture comes out from the immunohistochemical investigations either due to the technical procedures used or, intriguingly, to the possibility that diverse subtypes of TC might exist.Among the several markers used to label the TC, the most common are the CD34 and the PDGFRalpha, and, in many organs, the TC expresses both these markers. An exception is represented by the human urinary bladder where none of the TC, as recognized under the TEM, was double labelled. All the data indicate that TCs show immunohistochemical differences depending on the organ where they are located and/or the animal species.On the basis of their ubiquitous distribution, TCs are unanimously considered organizers of the connective tissue because of their ability to form 3-D networks. Close to this common role, numerous other roles have been attributed to the TC. Indeed, each of the TC subtype likely plays an own organ-/tissue-specific role contributing to different aspects of physiological regulation in the various anatomical niches they occupy.
结缔组织的间质空间中有几种细胞；其中，最近描述并命名了一种特殊类型的细胞，即间充质干细胞（TC）。对这种细胞类型的兴趣日益增加，使得几乎在所有器官中都能识别出它。所有的间充质干细胞都有适当的超微结构特征，这使得它们在透射电子显微镜（TEM）下无疑是可识别的。相反，免疫组织化学研究呈现出一幅复杂且常常令人困惑的画面，这要么是由于所使用的技术程序，要么是由于可能存在不同亚型的间充质干细胞。在用于标记间充质干细胞的几种标志物中，最常见的是CD34和血小板衍生生长因子受体α（PDGFRα），并且在许多器官中，间充质干细胞同时表达这两种标志物。人类膀胱是一个例外，在透射电子显微镜下识别出的所有间充质干细胞都没有双重标记。所有数据表明，间充质干细胞根据其所在的器官和/或动物物种表现出免疫组织化学差异。基于它们广泛的分布，间充质干细胞因其形成三维网络的能力而被一致认为是结缔组织的组织者。除了这个共同作用外，间充质干细胞还被赋予了许多其他作用。事实上，每种间充质干细胞亚型可能都发挥着自身器官/组织特异性的作用，对它们所占据的各种解剖学微环境中的生理调节的不同方面做出贡献。
