Vol 49, No 2 (2011)
Original paper
Submitted: 2011-12-19
Published online: 2011-07-11
Involucrin, but not filaggrin and Kdap mRNA, expression is downregulated in 3-D cultures of intact rat hair bulbs after calcium stimulation
Justyna Niderla-Bielińska, Stanisław Moskalewski
DOI: 10.5603/FHC.2011.0046
·
Folia Histochem Cytobiol 2011;49(2):335-343.
Vol 49, No 2 (2011)
ORIGINAL PAPERS
Submitted: 2011-12-19
Published online: 2011-07-11
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 Ca2+
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 Ca2+ 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)
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 Ca2+
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 Ca2+ 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)
Keywords
hair follicle; outer root sheath; inner root sheath; hair bulb; involucrin
Title
Involucrin, but not filaggrin and Kdap mRNA, expression is downregulated in 3-D cultures of intact rat hair bulbs after calcium stimulation
Journal
Folia Histochemica et Cytobiologica
Issue
Vol 49, No 2 (2011)
Article type
Original paper
Pages
335-343
Published online
2011-07-11
Page views
1455
Article views/downloads
2177
DOI
10.5603/FHC.2011.0046
Bibliographic record
Folia Histochem Cytobiol 2011;49(2):335-343.
Keywords
hair follicle
outer root sheath
inner root sheath
hair bulb
involucrin
Authors
Justyna Niderla-Bielińska
Stanisław Moskalewski
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