1. Serpins in the Human Hair Follicle
Pamela J. Jensen, Tien. Yang, Da-Wen. Yu, Mark S. Baker, Barbara. Risse, Tung-Tien. Sun, Robert M. Lavker 
Journal of Investigative Dermatology 
Volume 114, Issue 5, Pages (May 2000)
DOI: /j x
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
PAI-2 mRNA and antigen are present in the infundibulum of the human anagen hair follicle. Human scalp biopsies were processed for in situ hybridization using anti-sense (a) or sense (b) 35S-UTP-labeled RNA probes of human PAI-2 or (c) for immunohistochemistry using monoclonal anti-PAI-2 antibody #3750 with a DAB detection system. Note the strong signal for PAI-2 mRNA in the most differentiated living layers of the infundibulum (arrows in a). PAI-2 antigen is found in a comparable localization (c). Grains on the hair shaft (hs, panels a, b) are non-specific. IF, infundibulum.
Journal of Investigative Dermatology  , DOI: ( /j x)
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3. Figure 2
The companion layer comprises a morphologically distinct subpopulation of follicular epithelial cells. Human scalp biopsies were processed for paraffin sections and histologically stained with hematoxylin and eosin. (a) Low magnification of a hair follicle in longitudinal section. Areas within the rectangles are shown in higher magnification in (b) and (c). (b) Higher magnification of the pre-keratogenous zone, with the very thin companion layer cells marked with arrowheads. (c) Higher magnification of the keratogenous zone of the follicle. Note the transition zone where companion layer cells change from a flat (arrowheads) to a more cuboid (arrows) morphology, coinciding with keratinization of Henle's layer (He). ORS, outer root sheath; FP, follicular papilla; Hx, Huxley's layer; IRS, inner root sheath; M, matrix keratinocytes; Co, cortex.
Journal of Investigative Dermatology  , DOI: ( /j x)
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4. Figure 3
PAI-2 mRNA and antigen are present in the companion layer of the human anagen follicle. (a, b) Human scalp biopsies were processed for immunohistochemistry with monoclonal anti-PAI-2 antibody #3750. (a) A cross-section taken from deep in the anagen follicle shows a thin layer of stain corresponding to the companion layer cells (arrow). (b) A cross-section taken from a higher region of the follicle shows peripheral stain around the companion layer cells, which now show a more cuboidal morphology (compare with Figure 2c). (c–f) Human scalp biopsies were processed for PAI-2 mRNA in situ hybridization, as in Figure 1. (c) A cross-section incubated with anti-sense RNA shows signal in the cuboidal companion layer cells (arrows). (d) No signal is detected in the sense control on a serial section. (e) A section taken farther up the follicle contains signal in the irregularly shaped, further differentiated companion layer cells (arrows). (f) No signal is detected in the sense control on a serial section. IRS, inner root sheath; ORS, outer root sheath.
Journal of Investigative Dermatology  , DOI: ( /j x)
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5. Figure 4
PAI-2 mRNA is detectable in the human telogen hair follicle. Human scalp biopsies were processed for in situ hybridization as in Figure 1, with anti-sense PAI-2 mRNA probe (a–c) or sense control probe (d). (a) Low magnification of a telogen follicle in longitudinal section. (b) Higher magnification of the infundibulum (IF), showing signal in the more differentiated layers (arrows). (c, d) Higher magnification of the club hair (H) region showing signal with anti-sense probe in the outer root sheath cells immediately adjacent to the club hair (c; arrows) but no signal with the sense probe (d). FP, follicular papilla; SG, sebaceous gland.
Journal of Investigative Dermatology  , DOI: ( /j x)
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6. Figure 5
Relaxed PAI-2 is detectable in the infundibulum and companion layer of the human hair follicle. Human scalp biopsies were processed for frozen sections and immunohistochemistry using anti-relaxed PAI-2 antibody #2H5 (a, b) or anti-PAI-2 antibody #3750 (c) with a DAB detection system. (a) The infundibular region shows staining for relaxed PAI-2 around the periphery of the more differentiated cells (arrows), similar to the pattern observed with anti-PAI-2 antibody #3750 (compare with the serial section shown in Figure 1c). (b) The companion layer shown in cross-section has strong staining for relaxed PAI-2 around the cell periphery (arrows). (c) A serial section to that shown in panel b was stained with anti-PAI-2 antibody #3750, to illustrate that the staining patterns with the two antibodies are indistinguishable. IF, infundibulum; ORS, outer root sheath; IRS, inner root sheath.
Journal of Investigative Dermatology  , DOI: ( /j x)
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7. Figure 6
PN-1 mRNA is present in anagen human hair follicles. Scalp biopsies were processed for in situ hybridization using anti-sense (a, b, d) or sense (c) 35S-UTP-labeled mRNA probes of human PN-1. Anagen follicles in longitudinal section were examined (a). Signal was observed only in the follicular papilla (FP) shown in higher magnification in bright field (b; arrows) and dark field (d). Dashed line in panel d outlines the matrix keratinocytes (M) of the lower portion of the follicle. ORS, outer root sheath; SCF, subcutaneous fat; HF, hair fibre; M, matrix keratinocytes.
Journal of Investigative Dermatology  , DOI: ( /j x)
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8. Figure 7
PN-1 mRNA is not present in catagen human hair follicles. In catagen follicles (a, b), no signal was observed in the follicular papilla (FP; b) or other cell types. SG, sebaceous gland; CTS, connective tissue sheath; FE, follicular epithelium.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions