Novel type of interstitial cell (Cajal-like) in human fallopian tube.
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 MitoTracker-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 lamina propria and smooth muscle meshwork. t-ICC appeared located beneath of epithelium, in a 10-15 microm thick 'belt', where 18+/-2% of cells were t-ICC. In the whole lamina propria, t-ICC were about 9%, and in muscularis approximately 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 microm; thickness: < or =0.5 microm; aspect: moniliform; branching: 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 membrane potentials: 57.26+/-6.56 mV). Besides the CD117/c-kit marker, t-ICC expressed variously CD34, caveolins 1&2, alpha-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.
Popescu
L M
LM
Department of Cellular and Molecular Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, 050474, Romania. LMP@univermed-cdgm.ro.
Ciontea
Sanda M
SM
Cretoiu
D
D
Hinescu
M E
ME
Radu
E
E
Ionescu
N
N
Ceausu
M
M
Gherghiceanu
Mihaela
M
Braga
R I
RI
Vasilescu
Florina
F
Zagrean
L
L
Ardeleanu
Carmen
C
D000199:Actins / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D001485:Basement Membrane / Q000166:cytology / Q000648:ultrastructure; D001808:Blood Vessels / Q000648:ultrastructure; D018959:CD57 Antigens / Q000032:analysis; D021941:Caveolae / Q000648:ultrastructure; D022461:Caveolins / Q000032:analysis; D002452:Cell Count; D002467:Cell Nucleus / Q000648:ultrastructure; D022081:Cell Surface Extensions / Q000648:ultrastructure; D002478:Cells, Cultured; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D003239:Connective Tissue Cells / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004594:Electrophysiology; D005187:Fallopian Tubes / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007365:Intercellular Junctions / Q000648:ultrastructure; D007381:Intermediate Filament Proteins / Q000032:analysis; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000648:ultrastructure; D009092:Mucous Membrane / Q000166:cytology; D009130:Muscle, Smooth / Q000166:cytology / Q000648:ultrastructure; D009412:Nerve Fibers / Q000648:ultrastructure; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis; D013194:Staining and Labeling; D043222:Ubiquitin Thiolesterase / Q000032:analysis
D000199:Actins; D018952:Antigens, CD34; D018959:CD57 Antigens; D022461:Caveolins; D053379:Chromogranin A; D002864:Chromogranins; D007381:Intermediate Filament Proteins; D009418:S100 Proteins; C482860:UCHL1 protein, human; D019009:Proto-Oncogene Proteins c-kit; D043222:Ubiquitin Thiolesterase