Abstract |
In cultured human keratinocytes or murine epidermis, peroxisome proliferator-activated receptor beta/delta ( PPARbeta/delta) (NR1C2) activators (1) stimulate keratinocyte differentiation; (2) decrease keratinocyte proliferation; (3) accelerate permeability barrier repair; (4) increase epidermal lipid synthesis; and (5) reduce cutaneous inflammation. Since these results suggest that PPARbeta/delta could play an important role in cutaneous homeostasis, we assessed here the skin phenotype of mice deficient in PPARbeta/delta. Gross cutaneous abnormalities were not evident, and both stratum corneum (SC) skin hydration and surface pH were normal. However, the epidermis was thickened and proliferating cell nuclear antigen ( PCNA) staining was increased, indicating increased cell proliferation. No change in apoptosis was observed but the expression of differentiation markers, such as filaggrin, involucrin, and loricrin, was slightly increased in PPARbeta/delta(-/-) mice. Although basal permeability barrier function was normal, PPARbeta/delta knockout (KO) mice show a significant delay in barrier recovery rates following acute barrier disruption by either acetone treatment or tape-stripping. Delayed barrier recovery correlated with decreased production and secretion of lamellar bodies (LBs), and with reduced numbers of extracellular lamellar membranes in the SC. Finally, PPARbeta/delta KO mice displayed increased inflammation in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment. Together, these results further demonstrate that PPARbeta/delta in the epidermis: (1) is required for permeability barrier homeostasis; (2) regulates keratinocyte proliferation; and (3) modulates cutaneous inflammation.
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Authors | Mao-Qiang Man, Grant D Barish, Matthias Schmuth, Debra Crumrine, Yaacov Barak, Sandra Chang, Yan Jiang, Ronald M Evans, Peter M Elias, Kenneth R Feingold |
Journal | The Journal of investigative dermatology
(J Invest Dermatol)
Vol. 128
Issue 2
Pg. 370-7
(Feb 2008)
ISSN: 1523-1747 [Electronic] United States |
PMID | 17713572
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- FLG protein, human
- Filaggrin Proteins
- PPAR gamma
- PPAR-beta
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Topics |
- Acute Disease
- Animals
- Cell Division
(physiology)
- Dermatitis
(immunology, metabolism, pathology)
- Epidermis
(injuries, metabolism, pathology)
- Filaggrin Proteins
- Homeostasis
(physiology)
- Keratinocytes
(cytology, physiology)
- Male
- Mice
- Mice, Inbred Strains
- Mice, Knockout
- PPAR gamma
(chemistry, genetics, metabolism)
- PPAR-beta
(chemistry, genetics, metabolism)
- Permeability
- Protein Structure, Tertiary
- Wound Healing
(immunology)
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