MCP-1 facilitates VEGF production by removing miR-374b-5p blocking of VEGF mRNA translation

Monocyte chemotactic protein-1 (MCP-1) is known to be able to facilitate vascular endothelial growth factor (VEGF) gene expression, hence promoting vascular hyperpermeability and neovascularization. We show here that a microRNA molecule, miR-374b-5p can target the 3 '-untranslated region of the VEGF mRNA, thus pre-venting VEGF production. Additionally, MCP-1 promotes the acetylation of transcription factor stat3 at Lys685, which facilitates the formation of an ac-stat3-DNA methyltransferase-histone methyltransferase complex (ac-stat3/DNMT1/EZH2) that binds to the promoter of the miR-374b-5p gene. This results in diminished miR-374b-5p expression and enhanced VEGF production. Moreover, treatment of appropriate animal models either with a miR-374b-5p mimicry or with inhibitors of either stat3 acetylation, DNMT1, or EZH2, leads to marked inhibition of MCP-1-promoted neovascularization and tumor growth. These findings indicate that MCP-1 facilitated inhi-bition of miR-374b-5p gene expression leads to the removal of a block of VEGF mRNA translation by miR-374b-5p. This mechanism could be of importance in the modulation of inflammatory conditions.

Automated summary

In this study, it was found that MCP-1 promotes VEGF production while miR-374b-5p inhibits it by targeting the 3'-untranslated region of VEGF mRNA. MCP-1 also enhances the acetylation of transcription factor stat3, resulting in decreased expression of miR-374b-5p and increased VEGF production. Inhibiting stat3 acetylation, DNMT1, or EZH2 can effectively inhibit MCP-1-induced neovascularization and tumor growth.