ABSTRACT. 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 Research Note 17759MSC in psoriatic skin lesions ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 17758-17767 (2015) underlie KC proliferation and abnormal apoptosis in psoriasis skin lesions, which results in abnormal thickening of the epidermis.

ABSTRACT. Psoriasis is a common chronic relapsing inflammatory skin disease, in which mesenchymal stem cells (MSCs) have been hypothesized to play an important role in abnormal localized inflammation and vascular proliferation observed in skin lesions. Previous studies have revealed abnormal gene expression patterns, DNA methylation status, and cytokine secretion of MSCs in psoriatic skin lesions, as well as some gene expression abnormalities related to inflammation and angiogenesis. We further verified the gene and protein expressions of inflammation-related lipopolysaccharide-induced tumor necrosis factor-alpha transcription factor (LITAF), dual-specificity protein phosphatase 1 (DUSP1), and angiogenesis-related hematopoietically expressed homeobox (HHEX) in MSCs derived from the skin lesions of psoriasis patients. The gene expression of LITAF, DUSP1, and HHEX in dermal MSCs was measured at the mRNA level using reverse transcription-polymerase chain reaction and the corresponding protein expression levels were analyzed by western (2015) blotting analysis. The gene and protein expression levels of LITAF, HHEX, and DUSP1 in dermal MSCs were significantly lower in psoriasis patients compared to controls. Amplification and western blotting results were consistent with our previously reported gene chip data. Our results suggest that dermal MSCs in psoriatic skin lesions may be involved in the development, progression, and regulation of localized inflammatory abnormalities by reducing the expression of LITAF, HHEX, and DUSP1, which are related to inflammation and angiogenesis.