Gene Profiling of a 3D Psoriatic Skin Model Enriched in T Cells: Downregulation of PTPRM Promotes Keratinocyte Proliferation through Excessive ERK1/2 Signaling

Abstract

Psoriasis is a complex, immune-mediated skin disease involving a wide range of epithelial and immune cells. The underlying mechanisms that govern the epidermal defects and immunological dysfunction observed in this condition remain largely unknown. In recent years, the emergence of new, more sophisticated models has allowed the evolution of our knowledge of the pathogenesis of psoriasis. The development of psoriatic skin biomaterials that more closely mimic native psoriatic skin provides advanced preclinical models that will prove relevant in predicting clinical outcomes. In this study, we used a tissue-engineered, two-layered (dermis and epidermis) human skin substitute enriched in T cells as a biomaterial to study both the cellular and molecular mechanisms involved in psoriasis’ pathogenesis. Gene profiling on microarrays revealed significant changes in the profile of genes expressed by the psoriatic skin substitutes compared with the healthy ones. Two genes, namely, PTPRM and NELL2, whose products influence the ERK1/2 signaling pathway have been identified as being deregulated in psoriatic substitutes. Deregulation of these genes supports excessive activation of the ERK1/2 pathway in psoriatic skin substitutes. Most importantly, electrophoresis mobility shift assays provided evidence that the DNA-binding properties of two downstream nuclear targets of ERK1/2, both the NF-κB and Sp1 transcription factors, are increased under psoriatic conditions. Moreover, the results obtained with the inhibition of RSK, a downstream effector of ERK1/2, supported the therapeutic potential of inhibiting this signaling pathway for psoriasis treatment. In conclusion, this two-layered human psoriatic skin substitute enriched in T cells may prove particularly useful in deciphering the mechanistic details of psoriatic pathogenesis and provide a relevant biomaterial for the study of potential therapeutic targets.

Eicosapentaenoic Acid Influences the Lipid Profile of an In Vitro Psoriatic Skin Model Produced with T Cells

“…Each skin substitute was reconstructed according to the self-assembly method described previously elsewhere [ 27 ]. Fibroblasts at passage 5 were cultured over a period of 28 days in 6-well plates with a paper anchor, at a concentration of 1.2 × 10 4 cells/well.…”

“…Ascorbic acid was added to the medium to form fully manipulable dermal sheets. Human T cells were then isolated from the blood extract of healthy donors and polarized and activated according to the protocol previously reported by our team [ 27 ]. Briefly, T cells were isolated by negative selection from whole blood.…”

“…Briefly, T cells were isolated by negative selection from whole blood. Once isolated, T cells were polarized for 3 days towards Th1 and Il-17A phenotypes using specific antibody cocktails [ 27 ]. T cells were activated using a mixture of phorbol-12-myristate 13-acetate (PMA) and ionomycin (Sigma, St. Louis, MO, USA) and kept in culture for 4 more days with the addition of IL-2 and IL-23 (30 U/mL for IL-2 and 20 ng/mL for IL-23, R&D Systems, Burlington, ON, Canada).…”

Cellular Mechanisms of Skin Diseases

“…Although substantial research has been carried out to clarify the pathophysiology of skin diseases, much remains to be discovered regarding the cellular mechanisms of cutaneous disorders. In this context, the editors of the journal Cells decided to create a Special Issue, entitled “Cellular Mechanisms of Skin Diseases.” It encompasses six articles covering various aspects of skin structure [ 1 , 2 , 3 , 4 , 5 , 6 ].…”

“…Brewer et al demonstrated that keratinocyte differentiation in tandem with an inflammatory milieu (IL-4/13) or barrier disruption (TJDP treatment) substantially changes the susceptibility to viral infection [ 2 ]. A possible cellular mechanism of human hypertrophic scars and keloids was highlighted by Petrou and colleagues [ 3 ], and a 3D psoriatic skin model enriched in T cells and its gene profiling was shown by Rioux et al [ 4 ]. Second, Nowicka and colleagues assessed various aspects of lymphomatoid papulosis (LyP) and mentioned that because of the expanded risk of lymphoma development, patients diagnosed with LyP need lifelong follow-up, and many of them will develop malignant neoplasms in the future [ 5 ].…”