Author + information
- Wenting Hu2,1,
- Haocheng Lu1,
- Yanhong Guo1,
- Yanbo Fan1,
- Jifeng Zhang1,
- Daoquan Peng2 and
- Yuqing Eugene Chen1
Genome-wide association studies indicated that variations near the transcription factor Krüppel-like factor 14 (KLF14) encoded gene locus were highly associated with metabolic syndrome, diabetes mellitus and coronary artery disease (CAD). Our previous study reported that KLF14 inhibited atherosclerosis through upregulation of hepatic ApoA-I, but whether KLF14 exerts protective effects in other cell types remains largely unexplored. Endothelial inflammation plays a critical role in the initial and progressive stages of atherosclerosis. Here, we aimed to determine the role of KLF14 in vascular endothelial inflammation.
Cell culture Western blot RT-qPCR Immunofluorescence and confocal image Luciferase reporter assay Chromatin immunoprecipitation Leukocyte endothelial adhesion assay Intravital microscopy
We found mice aortic endothelial KLF14, determined by immunofluorescence and confocal image, was down-regulated in both acute and chronic inflammation. Adenovirus-mediated KLF14 overexpression inhibited pro-inflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor α(TNFα) induced inflammatory markers in human endothelial cells. Isolated pulmonary microvascular endothelial cells from KLF14 global knock out mice expressed increased adhesion molecules under TNFα stimuli. Mechanically, KLF14 potently inhibited NF-κB signaling pathway by suppressing the expression of NF-κB/Rel family members (p65, RelB, c-Rel, p105/p50 and p100/p52), especially RelB (decrease by >90%, p<0.05). KLF14 also reduced TNFα induced NF-κB response element-driving luciferase activity. Luciferase reporter assay and chromatin immunoprecipitation assay indicated that KLF14 could bind to p65 promoter directly and inhibit p65 expression at the transcriptional level. Functional studies demonstrated that KLF14 overexpression inhibited leukocyte adhesion to IL-1β or TNFα stimulated endothelial cells. In consistent with this, compared to wild type mice, increased leukocyte adhesion to endothelial cells was observed in vivo by intravital microscopy in endothelial specific KLF14 knock out mice after lipopolysaccharide(LPS) administration.
Together, our study uncovered the anti-inflammatory function of KLF14 in endothelial cells, suggesting that endothelial KLF14 could be a potential therapeutic target for endothelial inflammation and atherosclerosis.