The Development and Characterization of an In Vitro Model of Psoriasis Carol L. Barker, Mark T. McHale, Angela K. Gillies, John Waller, David M. Pearce, Joy Osborne, Peter E. Hutchinson, Gill M. Smith, James H. Pringle  Journal of Investigative Dermatology  Volume 123, Issue 5, Pages 892-901 (November 2004) DOI: 10.1111/j.0022-202X.2004.23435.x Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Reconstruction of human skin in vitro in a fully defined, serum-free environment. Keratinocytes were seeded onto collagen gels containing dermal fibroblasts and grown to a confluent monolayer. Subsequent exposure to the air–liquid interface for 21 d resulted in the formation of a fully differentiated epidermis. Figure shows typical morphology of normal, psoriatic involved and psoriatic uninvolved models after 7, 14, and 21 d of air exposure. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Proliferation of keratinocytes in normal and psoriatic models of human skin. Figure shows the mean number of Ki67 positive cells in normal (open columns), involved (black filled columns) and uninvolved (gray filled columns) psoriatic models cultured for 7, 14, and 21 d. Models derived from involved or uninvolved psoriatic skin showed higher rates of proliferation compared to normal models p<0.02 n=4. Proliferation rates were similar after 7 and 14 d culture but were significantly reduced after 21 d for all cases tested p<0.002. Error bars represent+SD. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Markers of keratinocyte proliferation and differentiation in normal and psoriatic models of human skin. Figure shows expression of Ki67, cytokeratin 16, cytokeratin 10, involucrin and filaggrin in organotypic models of normal and psoriatic (involved) human skin after 21 d of air exposure. Models derived from uninvolved psoriatic skin showed identical patterns of gene expression to those derived from involved skin (data not shown). In vivo normal and psoriatic (involved) skin is shown for comparison. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 4 Expression of primary cytokines in normal and psoriatic human skin models. Figure shows expression of TNF-α, IFN-γ, and IL-6 in models of normal and involved psoriatic human skin after 21 d of air exposure. Models derived from uninvolved psoriatic skin showed identical patterns of gene expression to those derived from involved skin. In vivo normal and involved psoriatic skin are also shown for comparison. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 5 Expression of CXCR1, CXCR2, and their major ligands in normal and psoriatic human skin models. The figure shows expression of CXCR1, CXCR2, IL-8, and GROa in normal and involved psoriatic human skin and in vitro models after 21 d of air exposure. Models derived from uninvolved psoriatic skin showed identical patterns of gene expression to those derived from involved skin (not shown). In vivo normal and involved psoriatic skin are also shown for comparison. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 6 Representative RT-PCR analysis of in vivo tissues and in vitro models showing CXCR2 and GAPDH mRNA expression. Gel electrophoresis of RT-PCR reactions using mRNA extracted from the following samples: in vivo skin: normal (1 and 2), psoriatic involved (3 and 4); in vitro skin models: normal (5 and 6), uninvolved (7 and 8), involved (9 and 10) after 14 d culture. Odd tracks show PCR reactions without a reverse transcriptase step (-) even tracks show complete RT-PCR reactions (+). PCR cycles were limited for CXCR2 to observe different levels of expression. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 7 ELISA detection of chemokine levels in conditioned culture media from skin models using luminex beads. Each panel shows the mean level of each chemokine detected in the culture medium for media sampled at 0, 2, 7, 14, and 21 days. Panels show the levels of IL-8 (A), IL-6 (B) and GRO-α (C) for normal skin models (open columns) (n=4) and psoriatic skin models (n=3) Black filled columns show results of models derived from involved skin and gray filled columns from uninvolved skin. Error bars represent mean±SEM. Journal of Investigative Dermatology 2004 123, 892-901DOI: (10.1111/j.0022-202X.2004.23435.x) Copyright © 2004 The Society for Investigative Dermatology, Inc Terms and Conditions