Macrophage-Kruppel-Like Factor 6 Signaling Promotes Experimental Atherogenesis

Abstract

A hallmark event in the development of atherosclerotic plaque is the accumulation of lipid-laden macrophages in the subendothelial layers of affected blood vessels. Macrophages are key players in all stages of atherogenesis, including plaque initiation, growth, and rupture, as well as healing of ruptured plaques. In this context, macrophages are the principal innate immune cells that modulate atherogenesis by engaging in various processes, such as inflammation, extracellular matrix degradation, phagocytosis, and efferocytosis. Here, this report shows that Kruppel-like factor 6 (KLF6) deficiency attenuates proinflammatory gene expression in macrophages and experimentally induced atherosclerotic plaque development. In vivo studies show that myeloid-KLF6 deficiency on Apoe-null background significantly curtails high-fat/high-cholesterol diet-induced atherosclerotic lesion formation and macrophage abundance in atherosclerotic plaques. Integrated transcriptomics and Gene Set Enrichment Analysis show that KLF6 deficiency significantly curtails a large number of tumor necrosis factor (TNF)-induced gene targets, TNF-induced interferon-γ response, interferon-α response, and inflammatory response signaling in macrophages. At the molecular level, KLF6 promotes IRF1 signaling to enhance TNF-induced proinflammatory gene expression in macrophages. Collectively, study results show that KLF6 promotes proinflammatory gene expression in macrophages and boosts experimentally induced atherosclerotic plaque formation in vivo.