Uraemic plasma decreases the expression of ABCA1, ABCG1 and cell-cycle genes in human coronary arterial endothelial cells.
BACKGROUND
Uraemia is associated with endothelial dysfunction, but the effect of uraemic plasma on the gene expression pattern of human coronary arterial endothelial cells (HCAEC) has never been defined.


METHODS
HCAECs were exposed for 48 h to a culture medium supplemented with 20% uraemic vs normal plasma. We extracted mRNA and hybridized it onto Affymetrix HG-U133 Plus2 microarrays. We validated our findings for five genes of interest by real-time PCR and performed evaluations of cell proliferation and apoptosis in HCAECs exposed to uraemic vs normal plasma.


RESULTS
Six genes involved in the regulation of cell-cycle progression (CDK-1, topoisomerase II, PDZ-binding kinase, CDCA1, protein SDP35, E2F transcription factor 8) and two genes of the cholesterol efflux system (ABCA1 and ABCG1) were down-regulated in HCAECs exposed to uraemic plasma (>1.75-fold change vs normal). Real-time PCR confirmed the down-regulation observed in the microarray experiment. Cell proliferation was significantly decreased in HCAECs exposed to uraemic vs normal plasma for 48 h (86 vs 95% of serum-starved control, P = 0.006). Exposure to uraemic plasma for 48 h was associated with increased apoptosis of HCAEC as compared with normal plasma (7.7 vs 2.8%, P < 0.001), a phenomenon that was further enhanced when oxidized LDLs (150 microg protein/ml) were added to the medium containing uraemic plasma (16.9 vs 7.7%, P < 0.001).


CONCLUSIONS
The down-regulation of genes involved in cell-cycle progression and cholesterol efflux from HCAECs exposed to uraemic conditions could contribute to enhancing endothelial dysfunction and atherosclerosis in patients with chronic renal failure.
Cardinal
Héloise
H
Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, 5400 Boulevard Gouin, Montreal, QC, Canada H4J 1C5.
Raymond
Marc-André
MA
Hébert
Marie-Josée
MJ
Madore
François
F
D064286:ATP Binding Cassette Transporter 1; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000235:genetics*; D000368:Aged; D017209:Apoptosis / Q000235:genetics; D002453:Cell Cycle / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology*; D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D010949:Plasma; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics*; D014511:Uremia / Q000097:blood* / Q000473:pathology
C577836:ABCA1 protein, human; C419353:ABCG1 protein, human; D064286:ATP Binding Cassette Transporter 1; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters; D012313:RNA