Expression of the L-Fucose Moiety on Infrainfundibular Follicular Keratinocytes of Terminal Follicles, Its Decreased Expression on Vellus and Indeterminate Follicles of Androgenetic Alopecia, and Re-Expression in Drug-Induced Hair Regrowth

Abstract

The distribution of various glycoprotein molecules on the surface of follicular keratinocytes was studied with a panel of lectins with specificity for various sugar moieties on biopsy specimens from both bald/balding scalp and normal occipital scalp, of 23 patients with androgenetic alopecia as well as on biopsies of normal forearm skin of four patients. The most significant differences between bald and normal scalp biopsy were noted with Ulex europaeus agglutinin I (UEA I). We noted an increased (91.8% +/- 3.1; mean +/- SE) expression of UEA I binding sites on the infra-infundibular follicular keratinocytes in anagen terminal scalp hairs, compared to 28.5% +/- 5.2 in the indeterminate (anagen) hairs of balding scalps, and 23.2% +/- 6.3 in the anagen follicles of vellus fore-arm hairs. By contrast, the telogen hairs demonstrated minimal UEA I staining: 4.0% +/- 0.8, mean +/- SE in telogen scalp hairs, 1.8% +/- 0.5 in telogen hairs of balding scalps (0% in completely bald scalps, in which all the hairs were in the telogen phase), and 1.9% +/- 0.2 in telogen forearm hairs. The percentage of UEA I staining correlated with the length of the infra-infundibular follicles in all cases studied. In three cases of hair regrowth after hair growth promotors, the UEA I staining increased to 80.6% +/- 6.1 in anagen hairs and correlated with increased length of infra-infundibular follicles. Our data indicate that there are 1) marked differences between anagen and telogen follicles in UEA I binding to infra-infundibular follicular keratinocytes; 2) the percentage of UEA I staining reflects the size (length) of the infra-infundibular hair follicle; and 3) the anagen follicles of balding scalps (indeterminate hairs) show UEA I staining resembling that exhibited by anagen follicles of vellus hairs.

Teloptosis, a Turning Point in Hair Shedding Biorhythms

“…[8, 9, 10, 11]. Cyclic changes in the differentiation of infundibular keratinocytes [12]and the involvement of the follicular immune system [13, 14]may also be part of the scene.…”

Hypomelanosis of Ito: pigmentary mosaicism with immature melanosome in keratinocytes

“…As the distribution patterns of the melanosomes in keratinocytes is one of the determining factors of skin color, 21,26 the present possible macroautophagy may play a prominent role in hypomelanosis of Ito. An unusual keratinocyte immunoreactivity was found for calprotectin (Mac 387) and fucose moieties (UEA‐1) that are commonly seen in keratinocytes altered both in their functions and viability 27–29 . Their combined expression in hypomelanosis of Ito suggests that keratinocytes are involved in addition to melanocytes.…”

Advances in Understanding Hair Growth

“…Thanks to the availability of new immunological tools, the distribution of proteoglycans in the human hair follicle has been further refined 49 ( Figure 4 ), highlighting a complex, dynamic, and regionalized network of proteoglycans. With respect to cell surface complex type N-glycans, the use of specific fluorescently labeled lectins (saccharide-binding proteins) revealed a differential N-glycan composition among the different hair follicle compartments 50 – 52 ( Figure 5 ).…”