The Mechanism of KLF4-Mediated NF-κB/NLRP3 Pathway Regulating Arteriovenous Fistula Dysfunction.

OBJECTIVE: Arteriovenous fistula (AVF) is the lifeline of maintenance hemodialysis (MHD), and AVF dysfunction is a major burden for MHD patients. It is important to modulate the vascular inflammatory response in pathological settings to protect endothelial proliferation and reduce AVF dysfunction. Krüppel-like factor 4 (KLF4) plays a key role in regulating the vascular endothelium in vascular homeostasis. In this study, we investigated the role of KLF4 in regulating the inflammatory pathway in vascular endothelial cells and its effect on biological behavior. METHODS: An lipopolysaccharide (LPS)-induced inflammatory injury human umbilical vein endothelial cell (HUVEC) model was established, and cell morphology changes were observed microscopically. The overexpression or knockdown efficiency of KLF4 was verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and the migration, proliferation, interleukin-6 and high sensitivity C-reactive protein expression levels of HUVECs were detected by Transwell assay, Cell Counting Kit-8 assay, and enzyme-linked immunosorbent assay, respectively. The expression levels of nuclear factor kappa-B (NF-κB) and nod-like receptor family pyrin domain containing 3 (NLRP3) were detected by RT-qPCR and Western blot. In addition, rescue experiments were performed by interfering with the NF-κB pathway to observe changes in experimental phenomena. RESULTS: Compared with conventional culture, morphological changes, proliferation and mobility of continuous LPS-induced HUVECs significantly increased, along with significantly increased levels of NF-κB, NLRP3 and inflammatory factors. The overexpression of KLF4 resulted in the inhibition of NF-κB, NLRP3 and inflammatory factors, while cell proliferation and migration were significantly reduced. In comparison, knockdown of KLF4 produced opposite effects. When combined with NF-κB inhibitors, the effect of knockdown KLF4 was reversed. CONCLUSIONS: KLF4 protects endothelial cell proliferation by modulating the vascular inflammatory response, and is a potential target for reducing AVF dysfunction.