Involucrin, but not filaggrin and Kdap mRNA, expression is downregulated in 3-D cultures of intact rat hair bulbs after calcium stimulation

Abstract

Abstract:Abstract: Abstract: Abstract: Abstract: The hair follicle consists of several distinctive epidermal cell layers. The hair root, which undergoes keratinization, is surrounded by two sheaths: the inner root sheath (IRS) and the outer root sheath (ORS). The ORS is continuous with the basal layer of the epidermis. Its cells do not keratinize in situ, unlike IRS. We have previously demonstrated that keratinization of the ORS was prevented by contact with the IRS in hair follicle mid-segments (i.e. fragments dissected from skin at the level above the hair bulb and below the opening of the sebaceous gland duct) cultured on agarose layer. The purpose of this study was to determine whether the same applies to the hair bulb. After isolation, intact bulbs or hair bulb-derived cells were incubated in suspension in a low or high calcium medium. The level of mRNA for differentiation markers: involucrin, filaggrin, keratinocyte differentiation associated protein and trichohyalin, was studied by RealTime PCR. We observed increased Ca 2+ upregulated expression of involucrin, filaggrin, trichohyalin and Kdap in cultures of bulb-derived cells, but in hair bulbs downregulation of involucrin and trichohyalin was observed. We concluded that the inner root sheath exerts an inhibitory effect on the expression of involucrin and trichohyalin already in the hair bulbs. The observation that downregulation of involucrin expression under Ca 2+ influence occurs both in hair bulb and midsegments could simplify future experiments, since their separation does not seem to be necessary. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 2, 335-343)

Epidermal differentiation complex (locus 1q21) gene expression in head and neck cancer and normal mucosa

“…It has to be stressed that the proteins originating from the complex structure of skin layers and regulating its keratinization may behave differently in various contexts [60,61]. When we compared our data with the analysis of Hudson et al, who suggested that coordinated over-expression of EDC genes is a hallmark of skin squamous cell carcinoma, we reached similar global conclusions [15].…”

Topical hesperidin improves epidermal permeability barrier function and epidermal differentiation in normal murine skin

“…While the expression of filaggrin and loricrin mainly localizes to the stratum granulosum and stratum corneum (43,44), involucrin is an early differentiation marker, which is mainly expressed in the stratum spinosum (45). Moreover, the mRNA expression for involucrin differs from filaggrin mRNA expression in rat hair bulb cultures, in which calcium downregulates involucrin mRNA expression, while stimulating filaggrin mRNA expression (46). Likewise, retinoic acid regulates loricrin, but not involucrin expression in vitro (43).…”