Gene profiling in atherosclerosis reveals a key role for small inducible cytokines: validation using a novel monocyte chemoattractant protein monoclonal antibody.
BACKGROUND
Pathological aspects of atherosclerosis are well described, but gene profiles during atherosclerotic plaque progression are largely unidentified.


RESULTS
Microarray analysis was performed on mRNA of aortic arches of ApoE-/- mice fed normal chow (NC group) or Western-type diet (WD group) for 3, 4.5, and 6 months. Of 10 176 reporters, 387 were differentially (>2x) expressed in at least 1 group compared with a common reference (ApoE-/-, 3- month NC group). The number of differentially expressed genes increased during plaque progression. Time-related expression clustering and functional grouping of differentially expressed genes suggested important functions for genes involved in inflammation (especially the small inducible cytokines monocyte chemoattractant protein [MCP]-1, MCP-5, macrophage inflammatory protein [MIP]-1alpha, MIP-1beta, MIP-2, and fractalkine) and matrix degradation (cathepsin-S, matrix metalloproteinase-2/12). Validation experiments focused on the gene cluster of small inducible cytokines. Real-time polymerase chain reaction revealed a plaque progression-dependent increase in mRNA levels of MCP-1, MCP-5, MIP-1alpha, and MIP-1beta. ELISA for MCP-1 and MCP-5 showed similar results. Immunohistochemistry for MCP-1, MCP-5, and MIP-1alpha located their expression to plaque macrophages. An inhibiting antibody for MCP-1 and MCP-5 (11K2) was designed and administered to ApoE-/- mice for 12 weeks starting at the age of 5 or 17 weeks. 11K2 treatment reduced plaque area and macrophage and CD45+ cell content and increased collagen content, thereby inducing a stable plaque phenotype.


CONCLUSIONS
Gene profiling of atherosclerotic plaque progression in ApoE-/- mice revealed upregulation of the gene cluster of small inducible cytokines. Further expression and in vivo validation studies showed that this gene cluster mediates plaque progression and stability.
Lutgens
Esther
E
Department of Pathology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands. e.lutgens@path.unimaas.nl
Faber
Birgit
B
Schapira
Kitty
K
Evelo
Chris T A
CT
van Haaften
Rachel
R
Heeneman
Sylvia
S
Cleutjens
Kitty B J M
KB
Bijnens
Ann Pascale
AP
Beckers
Linda
L
Porter
J Gordon
JG
Mackay
Charles R
CR
Rennert
Paul
P
Bailly
Veronique
V
Jarpe
Matthew
M
Dolinski
Brian
B
Koteliansky
Victor
V
de Fougerolles
Tony
T
Daemen
Mat J A P
MJ
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000494:pharmacology; D001013:Aorta, Thoracic; D001057:Apolipoproteins E / Q000172:deficiency; D050197:Atherosclerosis / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D018932:Chemokine CCL2 / Q000276:immunology; D054412:Chemokine CCL8; D018925:Chemokines / Q000235:genetics / Q000502:physiology*; D016000:Cluster Analysis; D018450:Disease Progression; D005109:Extracellular Matrix / Q000378:metabolism; D020869:Gene Expression Profiling; D007249:Inflammation / Q000235:genetics; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018945:Monocyte Chemoattractant Proteins / Q000276:immunology / Q000502:physiology; D010447:Peptide Hydrolases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D013997:Time Factors
D000911:Antibodies, Monoclonal; D001057:Apolipoproteins E; C491768:Ccl2 protein, mouse; C515454:Ccl8 protein, mouse; D018932:Chemokine CCL2; D054412:Chemokine CCL8; D018925:Chemokines; D018945:Monocyte Chemoattractant Proteins; D012333:RNA, Messenger; D010447:Peptide Hydrolases