Nitric oxide suppresses EPO-induced monocyte chemoattractant protein-1 in endothelial cells: implications for atherogenesis in chronic renal disease.
Patients with advanced chronic renal disease (CRD) suffer from excessive morbidity and mortality due to complications of accelerated atherosclerosis. Approximately 90% of dialysis-dependent end stage renal disease patients suffer from anemia. Recombinant human erythropoietin (EPO) in combination with iron has become widely used to treat anemic CRD patients. While treatment with EPO results in improved quality of life it may also contribute to the development of atherosclerosis. Recent studies suggest that a reduction in nitric oxide (NO) availability may be linked to EPO-induced vascular dysfunction. Furthermore, CRD per se is thought to result in a state of NO deficiency. The present study suggests that EPO may exert proatherogenic activity by augmenting the cytokine-induced expression of monocyte-chemoattractant protein-1 (MCP-1) in human umbilical vein endothelial cells (HUVECs) and by stimulating the proliferation of HUVECs and human vascular smooth muscle cells (HVSMCs). Augmentation of MCP-1 expression appears to be linked to EPO-induced downregulation of endothelial NO synthase (ecNOS). NO released from a series of synthetic donor compounds suppressed the EPO-mediated augmentation of cytokine-induced MCP-1 expression. In vitro studies revealed that EPO reduces ecNOS expression at both the protein and mRNA levels and that EPO also mediates a reduction in ecNOS enzymatic activity. These observations suggest potential mechanisms through which EPO may contribute to the development of accelerated atherosclerosis, particularly in the setting of CRD where NO availability may already be compromised.
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Anjali
A
Desai
Ying
Y
Zhao
Heather A
HA
Lankford
Jeffrey S
JS
Warren
D050197:Atherosclerosis / Q000209:etiology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000187:drug effects*; D015536:Down-Regulation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000166:cytology*; D004921:Erythropoietin / Q000009:adverse effects*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D016328:NF-kappa B / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects; D011994:Recombinant Proteins
D018932:Chemokine CCL2; D016328:NF-kappa B; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004921:Erythropoietin; D009569:Nitric Oxide