Chemokines mediate monocyte adhesion to dysfunctional endothelial cells (ECs) and promote arterial inflammation during atherosclerosis. Hypoxia-inducible factor (HIF)-1α is expressed in various cell types of atherosclerotic lesions and is associated with lesional inflammation. However, the impact of endothelial HIF-1α in atherosclerosis is unclear. HIF-1α was detectable in the nucleus of ECs covering murine and human atherosclerotic lesions. To study the role of endothelial HIF-1α in atherosclerosis, deletion of the Hif1 a gene was induced in ECs from apolipoprotein E knockout mice (EC- Hif1a −/− ) by Tamoxifen injection. The formation of atherosclerotic lesions, the lesional macrophage accumulation, and the expression of CXCL1 in ECs were reduced after partial carotid ligation in EC- Hif1a −/− compared with control mice. Moreover, the lesion area and the lesional macrophage accumulation were decreased in the aortas of EC- Hif1a −/− mice compared with control mice during diet-induced atherosclerosis. In vitro, mildly oxidized low-density lipoprotein or lysophosphatidic acid 20:4 increased endothelial CXCL1 expression and monocyte adhesion by inducing HIF-1α expression. Moreover, endothelial Hif1a deficiency resulted in downregulation of miR-19a in atherosclerotic arteries determined by microRNA profiling. In vitro, HIF-1α–induced miR-19a expression mediated the upregulation of CXCL1 in mildly oxidized low-density lipoprotein–stimulated ECs. These results indicate that hyperlipidemia upregulates HIF-1α expression in ECs by mildly oxidized low-density lipoprotein–derived unsaturated lysophosphatidic acid. Endothelial HIF-1α promoted atherosclerosis by triggering miR-19a–mediated CXCL1 expression and monocyte adhesion, indicating that inhibition of the endothelial HIF-1α/miR-19a pathway may be a therapeutic option against atherosclerosis.

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What is already known on this topic? While the US becomes increasingly diverse, Black, Latinx, Native American and Alaska Native, and other racial and ethnic minority groups remain underrepresented among US physicians. This disparity is associated with poor health outcomes in racial and ethnic minority populations.What is added by this report? Many previous interventions and mentorship programs aimed to diversify the health care workforce. We describe a novel and successful mentorship program run by racial and ethnic minority medical students and centered on antiracism in medicine.What are the implications for public health practice? Similar programs are likely to improve numbers of racial and ethnic minority physicians and reduce racial health disparities.