Nuclear Factor Kappa-B/Homeobox A9-Mediated Modulation of Leucine-Rich Repeat Flightless-Interacting Protein 1 Is Involved in Advanced Glycation End Product-Induced Endothelial Dysfunction

Abstract Background: Pathogenesis of cardiovascular diseases begins with endothelial dysfunction. Our previous study has shown that advanced glycation end products (AGE) could inhibit the expression of homeobox A9 (Hoxa9), thereby inducing endothelial dysfunction. Leucine-rich repeat flightless-interacting protein 1 (LRRFIP1) has been found to participate in a variety of pathological processes, but reports of its role in endothelial dysfunction are rare. Objectives: This study aims to investigate whether LRRFIP1 is involved in AGE-induced endothelial dysfunction through Hoxa9-mediated transcriptional activation. Methods: Chromatin immunoprecipitation was used to detect the transcriptional regulation of Hoxa9 on LRRFIP1 promoters. Human umbilical vein endothelial cells were treated with AGE or pyrrolidinedithiocarbamate (nuclear factor kappa-B [NF-κB] inhibitor). Moreover, changes in apoptosis, proliferation, migration, release of nitric oxide, and angiogenesis were detected. Results: Hoxa9 promotes LRRFIP1 expression by binding to the ­LRRFIP1 promoter. Meanwhile, overexpression of LRRFIP1 inhibited phosphorylation of P65 and elevated expression of Hoxa9. Overexpression of LRRFIP1 or/and Hoxa9 reversed the effects of AGE on HUVEC. AGE-induced inhibition on the expression of LRRFIP1 and Hoxa9 could be reversed by the NF-κB inhibitor. Conclusion: LRRFIP1 is involved in AGE-induced endothelial dysfunction via being regulated by the NF-κB/Hoxa9 axis.