Localization of fibroblast growth factor 2 (FGF-2) protein and the receptors FGFR 1-4 in normal human seminiferous epithelium.
Fibroblast growth factor 2 (FGF-2), which occurs in various isoforms both species and tissue specifically, regulates cell proliferation and differentiation via a dual receptor system consisting of heparan sulphate proteoglycans and receptor tyrosine kinases (FGFRs). This study demonstrates for the first time the distribution pattern of FGF-2 and the receptors FGFR 1-4 in the normal seminiferous epithelium of adult men. In western blot analyses, the polyclonal antibody, anti-FGF-2, shows two immunoreactive bands at 18 and 24 kDa. On paraffin sections, positive immunoreaction occurs within the cytoplasm of spermatogonia. The distribution pattern of the polyclonal anti-FGFR 1-4 antibodies is as follows: anti-FGFR-1 (one 68-kDa band) stains nuclei and cytoplasm of spermatogonia; anti-FGFR-3 (five bands at 68, 78, 105, 125 and 145 kDa) stains the nuclei of all germ cells except those of elongated spermatids; and anti-FGFR-4 (one 48-kDa band) stains the cytoplasm of primary pachytene spermatocytes. We were unable to demonstrate FGFR-2 immunoreactivity either in western blot analysis or on paraffin sections. This distribution pattern suggests that FGF-2 in spermatogonia is involved in the autocrine and paracrine regulation of the proliferation and differentiation of spermatogonia and spermatocytes via the receptors FGFR-1, FGFR-3 and FGFR-4.
Institute of Anatomy and Cell Biology, University of Halle, Germany.
K
K
Steger
F
F
Tetens
J
J
Seitz
C
C
Grothe
M
M
Bergmann
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D016222:Fibroblast Growth Factor 2 / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051498:Receptor, Fibroblast Growth Factor, Type 3; D051499:Receptor, Fibroblast Growth Factor, Type 4; D017468:Receptors, Fibroblast Growth Factor / Q000276:immunology / Q000378:metabolism*; D012670:Seminiferous Epithelium / Q000378:metabolism* / Q000648:ultrastructure; D013737:Testis / Q000378:metabolism / Q000648:ultrastructure
D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; C496348:FGFR1 protein, human; C496353:FGFR2 protein, human; C496365:FGFR3 protein, human; C496371:FGFR4 protein, human; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051498:Receptor, Fibroblast Growth Factor, Type 3; D051499:Receptor, Fibroblast Growth Factor, Type 4