Erythropoietin suppresses the formation of macrophage foam cells: role of liver X receptor alpha
| Autor: | Yuan Bin Yu, Ching Chian Pan, Tzong Shyuan Lee, Li Chieh Ching, Chien Yu Chen, Sheng Huang Hsiao, Li Ching Cheng, Kuo Yun Lu, Yu Chu Huang, Kuo Hui Su, Yu Ru Kou |
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| Rok vydání: | 2010 |
| Předmět: |
CD36 Antigens
medicine.medical_specialty Cardiotonic Agents Lipoproteins Aortic Diseases Mice Transgenic Biology Mice Apolipoproteins E Physiology (medical) Internal medicine medicine Macrophage Animals RNA Messenger Scavenger receptor Liver X receptor Erythropoietin Cells Cultured Foam cell ATP Binding Cassette Transporter Subfamily G Member 1 Liver X Receptors Scavenger Receptors Class A Scavenger Receptors Class B Atherosclerosis Orphan Nuclear Receptors Lipids Lipoproteins LDL Mice Inbred C57BL Haematopoiesis Endocrinology ABCG1 Biochemistry biology.protein lipids (amino acids peptides and proteins) ATP-Binding Cassette Transporters Cardiology and Cardiovascular Medicine medicine.drug Lipoprotein ATP Binding Cassette Transporter 1 Foam Cells |
| Zdroj: | Circulation. 121(16) |
| ISSN: | 1524-4539 |
| Popis: | Background— In addition to the hematopoietic effect of erythropoietin, increasing evidence suggests that erythropoietin also exerts protective effects for cardiovascular diseases. However, the role of erythropoietin and its underlying mechanism in macrophage foam cell formation are poorly understood. Methods and Results— Compared with wild-type specimens, erythropoietin was increased in atherosclerotic aortas of apolipoprotein E–deficient (apoE −/− ) mice, mainly in the macrophage foam cells of the lesions. Erythropoietin levels in culture medium and macrophages were significantly elevated in response to oxidized low-density lipoprotein in a dose-dependent manner. Furthermore, erythropoietin markedly attenuated lipid accumulation in oxidized low-density lipoprotein–treated macrophages, a result that was due to an increase in cholesterol efflux. Erythropoietin treatment significantly increased ATP-binding cassette transporters (ABC) A1 and ABCG1 mRNA and protein levels without affecting protein expression of scavenger receptors, including scavenger receptor-A, CD36, and scavenger receptor-BI. The upregulation of ABCA1 and ABCG1 by erythropoietin resulted from liver X receptor α activation, which was confirmed by its prevention on expression of ABCA1 and ABCG1 after pharmacological or small interfering RNA inhibition of liver X receptor α. Moreover, the erythropoietin-mediated attenuation on lipid accumulation was abolished by such inhibition. Finally, reduced lipid accumulation and marked increase in ABCA1 and ABCG1 were demonstrated in erythropoietin-overexpressed macrophages. Conclusion— Our data suggest that erythropoietin suppresses foam cell formation via the liver X receptor α–dependent upregulation of ABCA1 and ABCG1. |
| Databáze: | OpenAIRE |
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