Methyltransferase SETD4 mediates macrophages proliferation through EGFR signaling

Abstract

Abstract This study explored the effects of SET domain-containing protein (SETD)4, a histone lysine methyltransferase, on the general biological functions of bone marrow-derived macrophages (BMMs). BMMs from SETD4 knockout (KO) mice exhibited significant inhibition of monomethylation, dimethylation or trimethylation of histones H3K4, H3K36, H3K79 and H4K20; significant enhancement of the proliferation, EdU-positive cell ratio, Ki67 mRNA levels, and ability to form vascular structures; and attenuation of cell migration ability. After induction by lipopolysaccharide + interferon-γ or interleukin (IL)-4, a majority of the markers that were tested, including pro-inflammatory IL1β, IL6, iNOS and TNF-α and anti-inflammatory Fizz-1, Arginase 1 and Mannose receptor C-type 1 were all downregulated, while TGF-β1 was upregulated. The phosphorylation pathway profiling arrays focused on the MAPK, AKT, JAK/STAT, NF-κB, and TGF-β1 signaling pathways were performed, and the results revealed 32 differentially expressed proteins (DEPs), six that were upregulated and 26 that were downregulated in BMMs from SETD4KO mice versus wild type mice. These DEPs were involved in 1365 terms from the GO and 137 signals from the KEGG database. Inhibition of the most significantly upregulated protein EGFR(Ser1070), by CI-1033, an inhibitor for pan EGFR significantly reduced p-EGFR(Ser1070), and was accompanied by a decrease in the cell viability of BMMs, particularly in the SETD4 KO cells. This is the first study to implicate the involvement of SETD4-mediated EGFR signaling in the proliferation of BMMs. SETD4 mediates the methylation of multiple histone lysine sites in BMMs, in turn affecting cell biology.