title: Telocytes in human term placenta: morphology and phenotype.
abstract: In the last few years, a new cell type - interstitial Cajal-like cell (ICLC) - has been described in digestive and extra-digestive organs. The name has recently been changed to telocytes (TC) and their typical thin, long processes have been named telopodes (TP). To support the hypothesis that TC may also be present in human placenta and add to the information already available, we provide evidence on the ultrastructure, immunophenotype, distribution, and interactions with the surrounding stromal cells of TC in the villous core of human term placenta. We used phase-contrast microscopy, light microscopy of semithin sections, transmission electron microscopy, immunohistochemistry, and immunofluorescence of tissue sections or cell cultures, following a pre-established diagnostic algorithm. Transmission electron microscopy showed cells resembling TC, most (∼76%) having 2-3 very thin, longprocesses (tens to hundreds of micrometers), with an uneven calibre(≤0.5 μm thick) and typical branching pattern. The dilations of processes accommodate caveolae, endoplasmic reticulum cisternae, and mitochondria. These TC have close contacts with perivascular SMC in stem villi. In situ, similar cells are positive for c-kit, CD34, vimentin, caveolin-1, vascular endothelial growth factor (VEGF), and inducible nitric oxide synathase (iNOS). The c-kit-positive cells inconsistently co-express CD34, CD44, αSMA, S100, neuron-specific enolase, and nestin. Among cells with a morphologic TC profile in cell cultures, about 13% co-express c-kit, vimentin, and caveolin-1; 70% of the c-kit-positive cells co-express CD34 and 12% co-express iNOS or VEGF. In conclusion, this study confirms the presence of TC in human term placenta and provides their ultrastructural and immunophenotypic characterization.
authors.affiliation: Department of Cellular and Molecular Medicine, 'Carol Davila' University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Laura
authors.initials: L
authors.lastname: Suciu
authors.forename: Laurenţiu M
authors.initials: LM
authors.lastname: Popescu
authors.forename: Mihaela
authors.initials: M
authors.lastname: Gherghiceanu
authors.forename: Teodor
authors.initials: T
authors.lastname: Regalia
authors.forename: Mihnea I
authors.initials: MI
authors.lastname: Nicolescu
authors.forename: Mihail E
authors.initials: ME
authors.lastname: Hinescu
authors.forename: Maria-Simonetta
authors.initials: MS
authors.lastname: Faussone-Pellegrini
mesh_terms: D000199:Actins / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D021941:Caveolae / Q000648:ultrastructure; D051242:Caveolin 1 / Q000032:analysis; D018929:Cell Culture Techniques; D048430:Cell Shape; D002824:Chorionic Villi; D003239:Connective Tissue Cells / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis; D016130:Immunophenotyping; D007381:Intermediate Filament Proteins / Q000032:analysis; D056885:Interstitial Cells of Cajal / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008858:Microscopy, Phase-Contrast; D009419:Nerve Tissue Proteins / Q000032:analysis; D064231:Nestin; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D010920:Placenta / Q000166:cytology*; D011247:Pregnancy; D009418:S100 Proteins / Q000032:analysis
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D018952:Antigens, CD34; D051242:Caveolin 1; D018960:Hyaluronan Receptors; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin; D009418:S100 Proteins; D010751:Phosphopyruvate Hydratase