Involvement of JAK1, JAK2, and JAK3 in Stimulation of Functional Activity of Mesenchymal Progenitor Cells by Fibroblast Growth Factor

We studied the involvement of individual JAK kinases in the realization of the growth potential of mesenchymal precursors under the effect of fibroblast growth factor. The important role of JAK2 and JAK3 in determining the initial level of mitotic activity of progenitor cells and participation of JAK1 in this process under conditions of cytokine stimulation of progenitor cells were demonstrated. Specific inhibitors of these kinases reduced the yield of fibroblast CFU and the rate of their division. Moreover, blockade of JAK1, JAK2, and JAK3 under the effect of fibroblast growth factor was accompanied by an increase in the intensity of progenitor cell differentiation.