Novel type of interstitial cell (Cajal-like) in human fallopian tube

Abstract

We describe here ‐ presumably for the first time‐a Cajal‐like type of tubal interstitial cells (t‐ICC), resembling the archetypal enteric ICC. t‐ICC were demonstrated in situ and in vitro on fresh preparations (tissue cryosections and primary cell cultures) using methylene‐blue, crystal‐violet, Janus‐Green B or Mito Tracker‐Green FM Probe vital stainings. Also, t‐ICC were identified in fixed specimens by light microscopy (methylene‐blue, Giemsa, trichrome stainings, Gomori silver‐impregnation) or transmission electron microscopy (TEM). The positive diagnosis of t‐ICC was strengthened by immunohistochemistry (IHC; CD117/c‐kit+ and other 14 antigens) and immunofluorescence (IF; CD117/c‐kit+ and other 7 antigens). The spatial density of t‐ICC (ampullar‐segment cryosections) was 100–150 cells/mm2. Non‐conventional light microscopy (NCLM) of Epon semithin‐sections revealed a network‐like distribution of t‐ICC in lammina propria and smooth muscle meshwork. t‐ICC appeared located beneath of epithelium, in a 10–15μ thick ‘belt’, where 18±2% of cells were t‐ICC. In the whole lamina propria, t‐ICC were about 9%, and in muscularis ∼7%. In toto, t‐ICC represent ∼8% of subepithelial cells, as counted by NCLM. In vitro, t‐ICC were 9.9±0.9% of total cell population. TEM showed that the diagnostic ‘gold standard’ (Huizinga et al., 1997) is fulfilled by ‘our’ t‐ICC. However, we suggest a ‘platinum standard’, adding a new defining criterion ‐ characteristic cytoplasmic processes (number: 1–5; length: tens of μm; thickness: ±0.5μ; aspect: moniliform; braching: dichotomous; organization: network, labyrinthic‐system). Quantitatively, the ultrastructural architecture of t‐ICC is: nucleus, 23.6±3.2% of cell volume, with heterochromatin 49.1±3.8%; mitochondria, 4.8±1.7%; rough and smooth endoplasmic‐reticulum (1.1±0.6%, 1.0±0.2%, respectively); caveolae, 3.4±0.5%. We found more caveolae on the surface of cell processes versus cell body, as confirmed by IF for caveolins. Occasionally, the so‐called ‘Ca2+‐release units’ (subplasmalemmal close associations of caveolae+endoplasmic reticulum±mitochondria) were detected in the dilations of cell processes. Electrophysiological single unit recordings of t‐ICC in primary cultures indicated sustained spontaneous electrical activity (amplitude of field potentials: 57.26±6.56mV). Besides the CD117/c‐kit marker, t‐ICC expressed variously CD34, caveolins 1&2, α‐SMA, S‐100, vimentin, nestin, desmin, NK‐1. t‐ICC were negative for: CD68, CD1a, CD62P, NSE, GFAP, chromogranin‐A, PGP9.5, but IHC showed the possible existence of (neuro)endocrine cells in tubal interstitium. We call them ‘JF cells’. In conclusion, the identification of t‐ICC might open the door for understanding some tubal functions, e.g. pace‐making/peristaltism, secretion (auto‐, juxta‐ and/or paracrine), regulation of neurotransmission (nitrergic/purinergic) and intercellular signaling, via the very long processes. Furthermore, t‐ICC might even be uncommitted bipotential progenitor cells.

Cajal-type cells from human mammary gland stroma: phenotype characteristics in cell culture

“…However, after the year 2000, ICC-like cells (ICC-LC) have been found outside the gastrointestinal tract (reviews in 2005: [3,4]). Our laboratory reported the identification (at actual and quasi-complete standards) of ICC-LC in human pancreas [5,6], uterus [7] and fallopian tube [8]. In addition, preliminary results were published on in situ ICC-LC of human mammary glands [9].…”

Extrahepatic and Intrahepatic Human Portal Interstitial Cajal Cells

“…Giemsa stains previously identified ICLCs in the mammary gland stroma (Radu et al, 2005) and the fallopian tube (Popescu et al, 2005a). According to our findings, this stain is also reliable in identifying the PICCs/ portal telocytes, before any immunohistochemical labeling.…”

Telocytes in Human Fallopian Tube and Uterus Express Estrogen and Progesterone Receptors

“…The cell biology of TCs, and especially their function is a rapidly growing area of biomedical research (Figure 1) (freeaccess data is available at www.telocytes.com). TCs are also present in fallopian tube (Popescu et al, 2005a) and uterine walls . Progress in cellular and molecular techniques led to the identification of subtypes and isoforms of estrogen receptors (ER) (Green et al, 1986;Kuiper et al, 1996;Tremblay et al, 1997) and progesterone receptors (PR) (Kastner et al, 1990;Giangrande & McDonnell, 1999) in the female reproductive tract, two for each receptor (ER and , and PR A and B).…”