Human urine-derived stem cells: potential therapy for psoriasis-like dermatitis in mice

Over the past decade, significant advancements in stem cell research led by mesenchymal stem cells (MSCs) have facilitated their practical application in clinical settings, including inflammatory skin diseases. Urine-derived stem cells (USCs) are obtained from healthy human urine in a noninvasive approach with properties similar to mesenchymal stem cells (MSCs). However, the therapeutic potential of USCs for inflammatory skin diseases has not yet been fully explored. Herein, we report the therapeutic effects of USCs-derived culture supernatants on mice with psoriasis-like dermatitis using our originally established human USCs model. We examined the isolation of USCs from human urine using a simple centrifugation process. Cell markers related to MSCs-like cell were positive for CD29, CD44, CD73, CD90, and negative for HLA-DR, CD34, and CD45 by FACS analysis. Differentiation assays revealed that the cells possessed the capability to differentiate into adipocytes, chondrocytes, and osteocytes. USCs-conditioned medium (CM) treatment significantly suppressed the severity of dermatitis in imiquimod (IMQ)-treated psoriasis mice model. Histopathological examination revealed that USCs-CM treatment attenuated epidermal thickness and the numbers of infiltrating inflammatory cells, including neutrophils, T-cells, and macrophages in dermatitis-affected areas in IMQ-treated psoriasis mice. Furthermore, USCs-CM treatment decreased mRNA levels of IL-17A, IL-17F, and IL-23p19 was reduced in dermatitis area. In summary, our findings revealed new potential strategies for utilizing USCs and USCs-CM as therapeutic agents for inflammatory skin diseases, including psoriasis.