title: Rat hair follicle-constituting cells labeled by a newly-developed somatic stem cell-recognizing antibody: a possible marker of hair follicle development.
abstract: A3 was generated as an antibody recognizing somatic stem cells in rat tissues. We investigated the distribution of A3-positive cells in developing rat hair follicles by immunolabeling. A3-positive cells began to be seen in the hair germ and peg in fetuses and neonates; the positive cells were epithelial cells above basal cells. Furthermore, A3-positive cells were seen in the outer root sheath adjacent to the bulge in mature hair follicles. Double immunofluorescence revealed that these A3-positive epithelial cells reacted to E-cadherin (for all epithelial elements) but not to CK15 (for basal cells/epithelial stem cells) or to nestin (for stem cells), indicating that A3-positive epithelial cells are suprabasal cells in the developing epidermic hair follicle. Additionally, spindle-shaped mesenchymal cells surrounding the hair peg and mature hair follicle reacted to A3; in double immunofluorescence, the A3-positive cells were located outside collagen type IV-positive glassy membrane, and reacted to vimentin (for mesenchmal cells), Thy-1 (for immature mesenchymal cells), CD34 (for stem cells) and nestin, but not to α-smooth muscle actin (for myofibroblasts); the positive cells were regarded as immature mesenchymal cells with stem cell nature in the connective tissue sheath of developing hair follicles. A3-positive epithelial and mesenchymal cells did not show proliferating activity. Collectively, it is considered that A3-positive cells seen in developing rat hair follicles may be quiescent post-progenitor cells with the potential to differentiate into either highly-differentiated epithelial or mesenchymal cells. A3 would become a useful antibody to know the kinetics of rat hair follicle-constituting cells.
authors.affiliation: Laboratory of Veterinary Pathology, Division of Veterinary Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano-shi, Osaka, Japan.
authors.forename: Chisa
authors.initials: C
authors.lastname: Ichikawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Izawa
authors.forename: Vetnizah
authors.initials: V
authors.lastname: Juniantito
authors.forename: Miyuu
authors.initials: M
authors.lastname: Tanaka
authors.forename: Mayuka
authors.initials: M
authors.lastname: Hori
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takenaka
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kuwamura
authors.forename: Jyoji
authors.initials: J
authors.lastname: Yamate
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000378:metabolism*; D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D018859:Hair Follicle / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D023421:Models, Animal; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D011247:Pregnancy; D051381:Rats; D011916:Rats, Inbred F344; D013234:Stem Cells / Q000276:immunology*; D018800:Thy-1 Antigens / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D015415:Biomarkers; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D018800:Thy-1 Antigens