Effects of 1,25-dihydroxyvitamin D_3 and its 20-epi analogues (MC 1288, MC 1301, KH 1060), on clonal keratinocyte growth: evidence for differentiation of keratinocyte stem cells and analysis of the modulatory effects of cytokines

摘要

In conclusion, 1,25-(OH)_2D_3 and 20-epi vitamin D_3 analogues suppress clonal growth by directly inducing the differentiation of progenitor cells. It is conceivable that stimulation of stem cells differentiation is a major mechanism of action of vitamin D_3 compounds in psoriasis. Balance between different types of cytokines in psoriatic epidermis may be an important factor determining the clinical effect of vitamin D-based therapy.