Melanoma
miR-146b Probably Assists miRNA-146a in the Suppression of Keratinocyte Proliferation and Inflammatory Responses in Psoriasis
miR-146a inhibits inflammatory responses in human keratinocytes and in different mouse models of skin inflammation. Little is known about the role of miR-146b in the skin. In this study, we confirmed the increased expression of miR-146a and miR-146b (miR-146a/b) in the lesional skin of patients with psoriasis. The expression of miR-146a was approximately twofold higher than that of miR-146b in healthy human skin, and it was more strongly induced by stimulation of proinflammatory cytokines in keratinocytes and fibroblasts.Effects of Imiquimod on Hair Follicle Stem Cells and Hair Cycle Progression
Topical imiquimod (IMQ) application is widely used as a model for psoriasiform-like skin inflammation in mice. Although the effects on the epidermis are well characterized, it is unclear how IMQ affects hair follicles and cycling. Here we investigated how IMQ affects hair follicle stem cells and whether the timing of IMQ application influences the immune infiltrate. Our results show that IMQ application at mid and late telogen activated hair follicle stem cells leading to premature hair cycle entry (anagen), which was accompanied by massive infiltration of inflammatory macrophages and gamma delta T cells, whereas the number of the respective resident populations decreased.
