Telocytes in Parotid Glands

Authors

  • Mihnea I. Nicolescu,

    1. Molecular Medicine Department, “Victor Babes” National Institute of Pathology, Bucharest, Romania
    2. Cellular and Molecular Medicine Department, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
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  • Alexandru Bucur,

    1. Oral and Maxillo-Facial Surgery Department, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
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  • Octavian Dinca,

    1. Oral and Maxillo-Facial Surgery Department, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
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  • Mugurel C. Rusu,

    1. Division of Anatomy, Faculty of Dental Medicine, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
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  • Laurentiu M. Popescu

    Corresponding author
    1. Division of Advanced Studies, “Victor Babes” National Institute of Pathology, Bucharest, Romania
    • Division of Advanced Studies, “Victor Babes” National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
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    • Fax: +40213194528.


Abstract

The parotid histological structure includes acinar, ductal, and myoepithelial cells, surrounded by a connective stromal component. The parotid stroma is mostly regarded as an inert shell, consisting of septa, which divide the parenchyma. Telocytes were recently identified as a new stromal cell type in various organs, including exocrine pancreas. We aimed to evaluate telocytes presence in parotid stroma and whether their topographical features might support an involvement in parotid function modulation. Serial ultrathin sections of human and rat parotid glands were studied and compared by transmission electron microscopy. Two-dimensional concatenation of sequenced micrographs allowed the ultrastructural identification of parotid telocytes, with their specific long, thin, and moniliform prolongations (telopodes). Telocyte location appeared frequently as a strategic one, in close contact or vicinity of both secretory (acini and ducts) and regulatory (nerves and blood vessels) apparatuses. They were also found in the interacinar and the subductal stroma. Two previously reported telocyte markers (c-kit/CD117 and vimentin) were assayed by immunohistochemistry. Actin expression was also evaluated. Telocytes are making a network, especially by branching of their long telopodes. Elements of this telocyte network are interacting with each other (homocellular connections) as well as with other cell types (heterocellular connections). These interactions are achieved either by direct contact (stromal synapse), or mediated via shed microvesicles/exosomes. Since telocyte connections include both neurovascular and exocrine elements (e.g., acini and ducts), it is attractive to think that telocytes might mediate and integrate neural and/or vascular input with parotid function. Anat Rec, 2012. © 2011 Wiley Periodicals, Inc.

Ancillary