New Description of Telocyte Sheaths in the Bovine Uterine Tube: An Immunohistochemical and Scanning Microscopic Study

Abstract

Telocytes are a special type of interstitial cells characterized by distinctive cellular extensions with alternating thin segments (podomers) and dilations (podoms). Telocytes establish contact with various cells and structures, but their role in the regulation of the function of many cell types is still obscure. The aim of the current study was to investigate the morphology, histochemistry, and immunohistochemistry of telocytes, and their distribution, organization, and morphometric measurements in different layers of the adult bovine uterine tube. Telocytes showed positive immunostaining for CD117, S-100 protein, vimentin, desmin, α-smooth muscle actin, tubulin, laminin, estrogen receptor-α, and progesterone receptor. They were organized in different types of sheaths: subepithelial, inner/outer perimuscular, and intramuscular sheaths. Telocytes were scattered in the lamina propria, in the muscular layer, and the serosa. According to their size, they were grouped into different types of telocytes: small, large, and giant telocytes. Small telocytes were the most common type and located in all layers; large telocytes were observed in the epithelium, lamina propria, and inner/outer perimuscular and intramuscular sheaths, and giant telocytes were found in the external layer of the outer perimuscular sheath. Telocytes were connected by thin and thick telopodes (fenestrated membranes). Fenestrated membranes enabled connections between telocytes along the entire muscular wall of the uterine tube. Telocytes established an extensive biological network of different types of cells and structures, including epithelial, muscular, and mast cells, blood vessels, glomus, and nerve fibers. We hypothesize that telocytes help to organize the functional coordination between different types of cells in the uterine tube.

Localization of telocytes in rabbits testis: Histological and immunohistochemical approach

“…In the present study, SEM demonstrated a labyrinthine system connection of TCs with the surrounding tissues, cells, and blood vessels. Similar findings were reported in mammalian tissues such as; bovine uterine tubes (Abd‐Elhafeez and Soliman, ) and human placenta (Suciu et al, ) and non‐mammalian ones as; turtle testis (Yang et al, ) and chicken oviduct (Yang et al, ), suggesting that TCs may have a role in regulating the surrounding microenvironment through their labyrinthine system as a pacemaker in addition to their possible function in the regulation of blood stream.…”

“…A Similar distribution for CD34‐positive stromal cell was reported in normal human testicular tissue (Kuroda et al, ), turtle testis (Yang et al, ), human mammary gland stroma (Petre et al, ), and human ureter (Dobra et al, ). CD117 or c‐kit is one of the key markers for detection of mesenchymal cells as well as TCs in different organs such as; bovine uterine tube (Abd‐Elhafeez and Soliman, ), human testis (Hasirci et al, ; Rodriguez et al, ) human placenta (Suciu et al, ) , rat mesentery (Hinescu et al, ), and human gallbladder (Hinescu et al, ). Vimentin is a marker for undifferentiated cells and it stains the intermediate filaments that represent the basic component of cytoskeleton in various cells like TC, LC, muscle cell, fibroblast cells, and epithelial cells (Bornemann & Schmalbruch, ; Hinescu et al, ; Petre et al, ; Suciu et al, ).…”

“…In semi‐thin sections, telopodes displayed an alternation between thin segments (podomeres) and numerous distended segments (podoms) forming a moniliform appearance or beads‐like structure (Abd‐Elhafeez et al, ; Abd‐Elhafeez and Soliman, ; Bei et al, ; Manole and Simionescu, ; Yang et al, ).…”

Telocytes: New Connecting Devices in the Stromal Space of Organs

“…In inflammation and ischemia, TCs were shown to be lost and to suffer major ultrastructural changes, a process followed by interstitial fibrotic remodeling [99]. Abd-Elhafeez et al proposed a role for tubal TCs in the regulation of the epithelial function necessary for the final gamete maturation, fertilization, and early embryo development [100].…”

Morphological Alternations of Intraepithelial and Stromal Telocytes in Response to Salinity Challenges

“…Intraepithelial telocyte is previously detected by scanning electron microscopy in the bovine uterine tube. telocyte is located in the basal layer of the epithelial cells and their telopodes extended between epithelial cells (Abd-Elhafeez and Soliman 2016)…”