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Autori: Cretoiu SM, Cretoiu D, Marin A, Radu BM, Popescu LM
Editorial: Reproduction, 145(4), p.357-70, 2013.
Telocytes (TCs) have been described in various organs and species (www.telocytes.com) as cells with telopodes (Tps) – very long cellular extensions with an alternation of thin segments (podomers) and dilated portions (podoms). We examined TCs using electron microscopy (EM), immunohistochemistry (IHC), immunofluorescence (IF), time-lapse videomicroscopy and whole-cell patch voltage-clamp. EM showed a three-dimensional network of dichotomous-branching Tps, a labyrinthine system with homo- and hetero-cellular junctions. Tps release extracellular vesicles (mean diameter of 160.6±6.9 nm in non-pregnant myometrium and 171.6±4.6 nm in pregnant myometrium), sending macromolecular signals to neighbouring cells. Comparative measurements (non-pregnant and pregnant myometrium) of podomer thickness revealed values of 81.94±1.77 nm vs. 75.53±1.81 nm, while the podoms diameters were 268.6±8.27 nm vs. 316.38±17.56 nm. IHC as well as IF revealed double c-kit and CD34 positive results. Time-lapse videomicroscopy of cell culture showed dynamic interactions between Tps and myocytes. In non-pregnant myometrium, patch-clamp recordings of TCs revealed a hyperpolarization-activated chloride inward current with calcium dependence and the absence of L-type calcium channels. TCs seems to have no excitable properties as the surrounding smooth muscle cells. In conclusion, this study shows the presence of TCs as a distinct cell type in human non-pregnant and pregnant myometrium and describes morphometric differences between the two physiological states. In addition, we provide a preliminary in vitro electrophysiological evaluation of the non-pregnant state suggesting that TCs could influence timing of the contractile activity of smooth muscle cells.
Cuvinte cheie: telocite, uter // telocytes, human myometrium