Telocytes and lung disease

Telocytes (TCs) represent a new distinct type of interstitial cells found in many organs, including lungs. TCs are mainly defined by a small cellular body from which arise very long (hundreds of micrometers) extensions named telopodes. During the last years, TCs were characterized in respect with their microRNA profiles, gene features and proteome signatures. Also, the ultrastructural 3D configuration was further elucidated by the aid of the FIB-SEM technology. TCs are able to communicate by homo- and heterocellular contacts with neighboring cells and are also able to transfer genetic information and signaling molecules to influence other cells by means of extracellular vesicle release. However, the exact function of lung TCs remains unclear. Here, we review the potential significance of TCs in the pathogenesis of pulmonary diseases. We will also discuss some future possibilities for targeting TCs as a potential therapeutic strategy

Telocytes, a distinct type of cell among the stromal cells present in the lamina propria of jejunum

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 homeostasi

Myometrial interstitial cells and the coordination of myometrial contractility.

Abstract A strict regulation of contractility in the uterus and fallopian tube is essential for various reproductive functions. The uterus contributes, through either increased contractility or periods of relative quiescence, to: (a) expulsion of menstrual debris; (b) sperm transport; (c) adequate embryo placement during implantation; (d) enlarging its capacity during pregnancy; (e) parturition. The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation contractile force. Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles. These cells are similar to interstitial cells of Cajal (ICC) in the gut that are responsible for the generation of electrical slow waves that control peristalsis. A precise role for myometrial Cajal-like interstitial cells (m-ICLC) has not been identified. m-ICLC express the c-kit receptor, involved in creating and maintaining the ICC phenotype in the gastrointestinal tract. However, both acute and prolonged inhibition of this receptor with the c-kit antagonist imatinib mesylate does not appear to affect the spontaneous contractility of myometrium. Calcium imaging of live tissue slices suggests that contractile signaling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signaling from m-ICLC has been studied. This manuscript reviews the evidence regarding tissue-level signaling in the myometrium with a particular emphasis on the anatomical and possible functional aspects of m-ICLC as new elements of the contractile mechanisms in the uterus