Nuclear factor 90 isoform of vascular smooth muscle cells accelerates diabetic arteriosclerotic calcification by mediating FBXW7-AGER1-AGEs axis
Hyperglycemia accelerates calcification of atherosclerotic plaques in diabetic patients, and the prolonged accumulation of advanced glycation end products (AGEs) induced by hyperglycemia may be closely related to the pathogenesis of aortic calcification. However, the mechanisms underlying this association remain unclear. In the current study, we investigated the role of vascular smooth muscle cell nuclear factor 90/110 (NF90/110) in mediating AGEs accumulation and accelerating diabetic atherosclerotic calcification. Using vascular smooth muscle cells (VSMCs), human samples, and mouse models, we found that hyperglycemia-mediated AGEs markedly increased VSMC NF90/110 activation both in human and mouse atherosclerotic calcified tissues with diabetes. Silencing of NF90/110 in vitro and genetic deletion of VSMC NF90/110 in mice decreased obviously AGEs-induced arteriosclerotic calcification. Mechanistically, AGEs increased the activity of NF90, which then enhanced ubiquitination and degradation of AGE receptor 1 (AGER1) by stabilizing the mRNA of E3 ubiquitin ligase, F-box, and WD repeat domain 7 (FBXW7), thus causing the accumulation of more AGEs. Furthermore, AGEs accumulation accelerated diabetic atherosclerotic calcification by inducing VSMC phenotypic changes to osteoblast-like cells, apoptosis, and matrix vesicle release. Collectively, our study demonstrated the effects of VSMC NF90 in mediating the metabolic imbalance of AGEs to accelerate diabetic arteriosclerotic calcification. These novel findings elucidate a pivotal mechanism underlying AGE-induced diabetic atherosclerotic calcification and provide a framework for potential interventions against diabetic vascular complications. Overall design: To confirm that NF90 interacts with FBXW7 mRNA, RIP assays were performed using NF90 antibodies and IgG in HAVSMCs with or without stimulation by AGE.