ABSTRACT
Mesenchymal stem cells (MSCs) have pleiotropic immuno-modulatory effects and pro-angiogenic ability, leading to the presumption that MSCs may be involved in the pathogenesis of many inflammatory or autoimmune disorders, including psoriasis. In a previous study, we reported the specific gene expression profile of dermal MSCs from psoriasis. Inflammation- and angiogenesis-related genes, such as lipopolysaccharide-induced tumor necrosis factor-alpha transcription factor (LITAF), dual-specificity protein phosphatase 1 (DUSP1), vascular endothelial growth factor α (VEGFα), and insulin-like growth factor-binding protein-5 (IGFBP5), are abnormally expressed in psoriatic dermal MSCs. As a key regulator of gene expression, miRNA are involved in a wide variety of biological processes; in fact, several miRNAs have been implicated in the development and progression of inflammatory or autoimmune disorders. In this study, we compared the miRNA expression profiles of dermal MSCs from patients with psoriasis to those in MSCs from normal individuals by microarray, and found that the pro-inflammatory miRNA miR-155 was significantly overexpressed in psoriatic MSCs (2.44 fold, P < 0.001). Additionally, the expression of miR-155 target gene TAB2 (8.47 ± 1.55 vs 6.38 ± 2.10, P < 0.01,) and the downstream gene iNOS (5.26 ± 2.58 vs 3.73 ± 1.89, P < 0.05) was found to be inhibited in psoriatic dermal MSCs by real-time PCR. Therefore, we speculated that the elevation in miR-155 levels may be an indicator of, or a key regulatory pathway in, the pathogenesis of psoriasis, resulting in functionally impaired dermal MSCs.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Dermis/metabolism , Gene Expression Regulation , Mesenchymal Stem Cells/metabolism , MicroRNAs/genetics , Psoriasis/genetics , Adaptor Proteins, Signal Transducing/metabolism , Adult , Case-Control Studies , Dermis/pathology , Female , Humans , Male , Mesenchymal Stem Cells/pathology , MicroRNAs/metabolism , Middle Aged , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , Oligonucleotide Array Sequence Analysis , Psoriasis/metabolism , Psoriasis/pathology , Real-Time Polymerase Chain Reaction , Severity of Illness Index , Signal TransductionABSTRACT
Psoriasis is an inflammatory skin disease characterized by excessive proliferation and abnormal differentiation and apoptosis of keratinocytes (KCs). Mesenchymal stem cells (MSCs) from skin lesions of psoriasis patients demonstrate abnormal cytokine secretion, which may affect KC proliferation and apoptosis. Here, we explored how MSCs from skin lesions of psoriasis patients affect HaCaT cell proliferation and apoptosis. First, flow cytometry and multipotent differentiation methods were used to identify skin MSCs, which were then co-cultured with HaCaT cells. HaCaT cell proliferation was analyzed in real-time, and cell cycle progression and apoptosis were assessed by flow cytometry. Cell morphologies and multipotencies of skin MSCs were similar between the psoriasis group and healthy control group, with high levels of CD29, CD44, CD73, CD90, and CD105 and limited expression of CD34, CD45, and HLA-DR. MSCs from skin lesions of psoriasis patients promote KC proliferation more potently and are less capable of inducing KC apoptosis. This may underlie KC proliferation and abnormal apoptosis in psoriasis skin lesions, which results in abnormal thickening of the epidermis.