Skin Barrier, Ions, Cytokines

The document discussed the importance of the calcium (Ca2+) gradient in skin development and wound healing. It highlighted that the epidermal permeability barrier forms late in fetal development, coinciding with the establishment of the Ca2+ gradient, which is low in basal and spinous layers and highest in the granule layer. The study referenced findings that CaR-/- mice exhibited abnormalities in epidermal development, such as increased keratinocyte proliferation and decreased expression of differentiation markers. In contrast, transgenic mice overexpressing CaR showed early barrier formation and enhanced expression of differentiation markers. The research concluded that CaR is a critical sensor of the epidermal Ca2+ gradient, essential for keratinocyte differentiation and epidermal development.