1. Changing Patterns of Localization of Putative Stem Cells in Developing Human Hair Follicles 
Masashi Akiyama, Lynne T. Smith, Hiroshi Shimizu 
Journal of Investigative Dermatology 
Volume 114, Issue 2, Pages (February 2000)
DOI: /j x
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
β1 integrin-rich cells are seen in the entire hair germ, in the outer layer of the hair peg, and in the outermost layer of the early bulbous hair peg. Hair germ cells express γ-catenin only weakly compared with those of interfollicular epidermis (a, b). β1 integrin is strongly expressed in the entire hair germ (c) and the outer cells of the hair peg (e). The expression of γ-catenin is weak in the outer cells of the hair peg (d). α2 integrin is brightly expressed in the outermost cells of the early bulbous hair peg and the basal layer of the interfollicular epidermis (f). Specific immunostainings are demonstrated with fluorescein isothiocyanate (FITC, green) and nuclear stain is done with propidium iodide (red). Yellowish stain is caused mainly by the overlap of FITC fluorescence and propidium iodide fluorescence and partly by the nonspecific detection of FITC fluorescence by the filter for propidium iodide. (a–c) Hair germ (65–84 d EGA), (d, e) hair peg (85–104 d EGA), (f) early bulbous hair peg (108 d EGA), (c, e) β1 integrin, (f) α2 integrin, (a, b, d) γ-catenin (4F11); scale bars: 50 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
β1 integrin-rich, E-cadherin-, β-catenin-, γ-catenin-poor cells are seen in the outermost layer of the ORS, but not in the matrix of the bulb in the lower portion of differentiated lanugo hair follicle (>135 d EGA). Bright stainings of β1 integrin (a), α2 integrin (b), and α3 integrin (c) are observed in the outermost layer (arrowheads) of the ORS. The outermost layer (arrowheads) of the ORS expresses E-cadherin (d), β-catenin (e), and γ-catenin (f) very weakly. The matrix cells of the bulb are strongly stained with α2 integrin (b) and weakly stained with E-cadherin (d); however, in contrast to the outermost layer of the ORS, the matrix cells of the bulb express β1 integrin (a) and α3 integrin (c) only weakly and are brightly stained with β-catenin (e) and γ-catenin (f). Specific immunostainings are demonstrated with FITC (green) and nuclear stain is done with propidium iodide (red). (a) β1 integrin, (b) α2 integrin, (c) α3 integrin, (d) E-cadherin (HECD-1), (e) β-catenin (Clone 14), (f) γ-catenin (4F11); scale bar: 50 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
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4. Figure 3
The modified images clearly demonstrate that the bulge of the lanugo hair follicle (>135 d EGA) consists of β1 integrin-rich, E-cadherin-, β-catenin-, γ-catenin-poor cells. Deletion of the weak signals from the immunofluorescent images of the mid-portion of the lanugo hair follicle revealed that the strong signals of β1 integrin (a), α2 integrin (b), and α3 integrin (c) remain in the bulge (arrowheads), although cells in the bulge (arrowheads) show no strong signals of E-cadherin (d), β-catenin (e), and γ-catenin (f). Specific immunostainings are demonstrated with FITC (green) and nuclear stain is done with propidium iodide (red). (a) β1 integrin, (b) α2 integrin, (c) α3 integrin, (d) E-cadherin (HECD-1), (e) β-catenin (5H10), (f) γ-catenin (4F11); scale bar: 50 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
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5. Figure 4
K19-positive, EGF receptor-rich cells are also seen in the bulge and the outermost layer of the lanugo hair follicle. (a) In the lanugo hair follicle (136 d EGA), cells in the bulge (arrows) and in the outermost layer of the ORS (arrowheads) are K19-positive. (b) Cells in the bulge (arrows) and in the outermost layer of the ORS (arrowheads) show stronger immunoreactivity for EGF receptor than the other parts of the developing hair follicle. (a) K19 staining; (b) EGF receptor staining; arrows, bulge; arrowheads, outermost layer of ORS; scale bar: 50 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
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6. Figure 5
Cells in the hair germ, the outer layer of hair peg, and the bulge and the outermost layer of the bulbous hair peg show similar, undifferentiated morphologic features. Electron microscopy reveals that hair germ cells (a), cells in the outer layer of hair peg (b), cells in the bulge of bulbous hair peg (c), and cells in the outermost layer of the ORS of bulbous hair peg (d) show a reduced amount of intermediate filament bundles and rough endoplasmic reticulum, and abundance of glycogen particles and free ribosomes in the cytoplasm. The nucleus/cytoplasm ratio of these cells is high and chromatin aggregation in the nuclei appears poor. (a) Cells in the hair germ (69 d EGA); (b) cells in the outer layer of hair peg (89 d EGA); (c) cells in the bulge of bulbous hair peg (125 d EGA); (d) cells in the outermost layer of the ORS of bulbous hair peg (125 d EGA); scale bars: 1 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
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7. Figure 6
Sequential localization of β1 integrin-rich, E-cadherin-, β-catenin-, γ-catenin-poor cells during human fetal hair follicle development. Ontogenically, β1 integrin-rich, E-cadherin-, and β- and γ-catenin-poor cells, possible hair follicle stem cells, are restricted to the entire hair germ, the outer cells of hair peg, then the bulge and the outer layer cells of the bulbous hair peg, and finally the bulge and the outermost cells of the ORS of lanugo hair follicle. Dotted area, restriction sites of β1 integrin-rich, E-cadherin-, and β- and γ-catenin-poor cells; arrows, the bulge.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions