Interleukin-1 Beta Promotes the Expression of Prox-1 and Vascular Endothelial Growth Factor Receptor Type-3 in Adult Human Dermal Fibroblasts

We recently reported that human interleukin 1 beta (IL-1 beta) stimulates bone-marrow stromal myofibroblasts to express a hematopoietic stem cell marker, CD34 (16^th EHA, and 53^rdASH meeting). To characterize precisely the effects of IL-1 beta to the stromal cells, adult human dermal fibroblasts (HDF) were cultured with IL-1 beta, and the morphological changes and molecular expressions were observed.

HDF were purchased, and cultured in knockout DMEM medium with 15% KSR with or without recombinant human IL-1 beta for 3 weeks. The morphological changes and the expression of specific hematopoiesis-related genes were analyzed time-dependently. The concentration of hematopoietic growth factors in the culturing supernatants was also measured.

When HDF were cultured with human IL-1 beta for 3 weeks, the cellular morphology changed to the filamentous appearance. RT-PCR analyses revealed that cells expressed Prox-1, a master molecule for lymphatic duct neogenesis, and also vascular endothelial growth factor receptor (VEGFR) type-3. Smad7 and PAI1 were also expressed; however, LYVE1, a marker for lymphatic vascular endothelial cell, was not induced. VEGF-C production was also demonstrated at RNA and protein levels, and VEGF-C and VEGFR type-3 system played an important role in morphological changes and cell-proliferation.

We previously reported that when HDF were cultured in DMEM/F12 medium with IL-1 beta and EPO, hematopoietic markers were induced. When HDF were cultured in knockout DMEM, a condition for immature cell-growth at ES cell levels, and IL-1 beta, lymphatic duct neogenesis-related genes were activated, and HDF converted their morphology without an introduction of any genes externally. We are now making clear the precise action of IL-1 beta to HDF using microarray analysis.

No relevant conflicts of interest to declare.