Telocytes, a distinct type of cell among the stromal cells present in the lamina propria of jejunum
D. Cretoiu1,2*, Sanda M. Cretoiu1,2*, Anca A. Simionescu3 and L.M. Popescu1,2
1Department of Cellular and Molecular Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, Bucharest, Romania, 2‘V. Babes’ National Institute of Pathology, Bucharest, Romania and 3Department of Obstetrics and Gynecology, Filantropia Hospital, Bucharest, Romania
*Authors have contributed equally.
Offprint requests to: Professor L.M. Popescu, P.O.Box 35-29, Bucharest 35, Romania. e-mail: LMP@jcmm.org
Summary. Conventionally, cells described in the stroma of the intestinal wall are fibroblasts/fibrocytes, mast cells, plasma cells, eosinophils, macrophages and, interstitial cells of Cajal (ICCs), the latter being considered as the pacemakers of gastrointestinal rhythmicity. Recently, a new type of stromal cell called telocyte (TCs) was found in various cavitary and non-cavitary organs (www.telocytes.com). We show here direct electron microscopical evidence for the presence of TCs in the lamina propria of rat jejunum just beneath the epithelial layer of the mucosal crypts and in between the smooth muscle cells (SMCs) of muscularis mucosae. TCs are characterized by: several very long (tens to hundreds of µm) prolongations called telopodes (Tps). Tps (with caliber below the resolving power of light microscopy) display podomeres (thin segments ≤0.2 µm) and podoms (dilations accommodating caveolae, mitochondria, and endoplasmic reticulum). Tps present dichotomous branching and form a three dimensional network close to immune cells, SMCs or nerve bundles. TCs could play a role in intercellular signaling and control of local tissue homeostasis. Histol Histopathol 27, 1067-1078 (2012)
Key words: Telocytes, Telopodes, Stromal cells, Fibroblasts, Cell signaling