Vascular Endothelial Growth Factor Receptor 1 Facilitates the Effect of Macrophages on Human Umbilical Vein Endothelial Cells Migration by Regulating the M1 Polarization

Abstract

Purpose: To explore the impact of VEGF pathway on the M1 polarization and function of macrophages. Methods: VEGFR-knockdown macrophages were established by transfected with a shRNA. M1 macrophages were stimulated by LPS and IFN-γ, which was identified using the flow cytometry. Subsequently, M1 macrophages were treated with VEGF A, VEGF B, and PIGF, respectively. The expression level of iNOS, TNF-α, and IL-6 was detected utilizing RT-PCR. CD86 and iNOS level were checked by Western blot. The migration of HUVEC was evaluated by wound healing assay. Results: The percentage of F4/80+CD86+ macrophages was significantly elevated by the transfection of shRNA, accompanied by a significantly upregulated expression of CD86 and iNOS. After the stimulation of LPS and IFN-γ, CD86 and iNOS was dramatically upregulated in both the Lv-NC group and Lv-shVEGFR1 group. IL-6 and iNOS levels were greatly declined in macrophages co-treated with LPS, IFN-γ, and PIGF. No marked alterations on the healing degree were noticed in HUVEC stimulated by the supernatant of LPS/IFN-γ treated macrophages, which was dramatically declined by the knockdown of VEGFR1. Conclusion: VEGFR1 facilitated the effect of macrophages on HUVEC migration by regulating the M1 polarization.