The Tissue-Engineered Human Psoriatic Skin Substitute: A Valuable In Vitro Model to Identify Genes with Altered Expression in Lesional Psoriasis

Abstract

Psoriasis is a chronic inflammatory skin disease for which no cure has emerged. Its complex etiology requires the development of an in vitro model representative of the pathology. In this study, we exploited gene profiling analyses on microarray in order to characterize and further optimize the production of a human psoriatic skin model representative of this in vivo skin disease. Various skin substitutes were produced by tissue-engineering using biopsies from normal, healthy donors, or from lesional or non-lesional skin samples from patients with psoriasis, and their gene expression profiles were examined by DNA microarray. We demonstrated that more than 3540 and 1088 genes (two-fold change) were deregulated between healthy/lesional and lesional/non-lesional psoriatic substitutes, respectively. Moreover, several genes related to lipid metabolism, such as PLA2G4E and PLA2G4C, were identified as repressed in the lesional substitutes. In conclusion, gene profiling analyses identified a list of deregulated candidate genes associated with various metabolic pathways that may contribute to the progression of psoriasis.

Keywords: gene profiling; psoriasis; tissue-engineering.

Figure 1

Macroscopic analysis of the reconstructed skin substitutes. For each group, tissue-engineered skin substitutes were produced with three different cell populations. (A–C) Tissue-engineered skin substitutes produced with healthy fibroblasts and keratinocytes. (D–I) Tissue-engineered skin substitutes produced with fibroblasts and keratinocytes isolated from either non-lesional (D–F) or lesional (G–I) psoriatic skin. Scale bar = 1 cm. Black arrowheads indicate the position of protuberant regions, whereas white arrowheads position thinner regions of the reconstructed skin substitutes.

Figure 2

Histological analysis of the reconstructed skin substitutes. Mason’s trichrome staining after 21 days of culture at the air-liquid interface. For each group, tissue-engineered skin substitutes were produced with three different cell populations. (A–C) Healthy skin substitutes. (D–F) Non-lesional psoriatic skin substitutes. (G–I) Lesional psoriatic skin substitutes. Scale bar = 100 µm. C: Stratum corneum; E: Epidermis; D: Dermis.

Figure 3

Microarray analysis. (A) Scatter plot of log2 of signal intensity from 60,000 different targets covering the entire human transcriptome of healthy or non-lesional tissue-engineered skin substitutes (in the y-axis) against non-lesional (first graph) or lesional (last two graphs) (in the x-axis). (B) Heatmap representation of genes whose expression is differentially regulated by at least two-fold in healthy against lesional substitutes and in non-lesional against lesional substitutes. (C) Venn diagram that indicates the number of deregulated genes in healthy against lesional substitutes (red circle) and in non-lesional against lesional substitutes (green circle). Genes that are commonly deregulated between these two groups are indicated in yellow. (D) Heatmap representation of the 55 most deregulated genes expressed by lesional substitutes relative to healthy substitutes (left) and non-lesional substitutes against lesional substitutes (right). The most highly expressed genes are shown in red, while the most weakly expressed are in blue. The genes with red writing are those identified as similarly deregulated between the two heatmaps. H: healthy; L: lesional; NL: non-lesional.