Plasma profiling by a protein array approach identifies IGFBP-1 as a novel biomarker of abdominal aortic aneurysm.
OBJECTIVE
Cytokines are important mediators of immune-inflammatory responses implicated in abdominal aortic aneurysm (AAA) pathogenesis. Our objective was to investigate the cytokine expression profile in plasma of AAA patients.


METHODS
Cytokine protein expression was measured in plasma of 5 large AAA patients (aortic size >50mm) and 5 controls (aortic size <30 mm) using a 20-cytokine antibody-based protein array. IGFBP-1 plasma concentrations were analyzed by ELISA. IGFBP-1 protein levels were analyzed in AAA thrombus by immunohistochemistry and Western blot. Platelet aggregation was assessed by conventional optical aggregometry.


RESULTS
Several proteins including MIP-3 alpha (CCL20), Eotaxin-2 and IGFBP-1 were increased in AAA patients compared to controls. Among them, IGFBP-1 concentrations were significantly higher in large AAA patients vs control subjects. These data were validated in plasma of patients with large AAA (n = 30) compared to matched controls (n = 30) [834(469-1628) vs 497(204-893) pg/ml, p<0.01]. Furthermore, the potential association of IGFBP-1 with AAA size was analyzed in a second independent group of subjects [large AAA (n = 59), small AAA patients (aortic size = 30-50mm, n = 54) and controls (n = 30)]. Interestingly, IGFBP-1 levels correlated with AAA size (r = 0.4, p<0.001), which remained significant after adjusting for traditional risk factors. IGFBP-1 was localized in the luminal part of AAA thrombus and IGFBP-1 levels were increased in AAA thrombus conditioned media compared to media layer and healthy media. Interestingly, IGFBP-1 abrogated the potentiation of ADP-induced platelet aggregation triggered by IGF-1.


CONCLUSIONS
IGFBP-1 has been identified by a protein array approach as a potential novel biomarker of AAA. The biological role of IGFBP-1 in AAA pathogenesis could be related to the modulation on the effect of IGF-1 on platelet aggregation.
Vascular Research Lab, Diaz-Autonoma University, Madrid, Spain.
P
P
Ramos-Mozo
C
C
Rodriguez
C
C
Pastor-Vargas
L M
LM
Blanco-Colio
J
J
Martinez-Gonzalez
O
O
Meilhac
J-B
JB
Michel
M
M
Vega de Ceniga
J
J
Egido
J L
JL
Martin-Ventura
D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000097:blood* / Q000000981:diagnostic imaging / Q000276:immunology; D001027:Aortography / Q000379:methods; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D016022:Case-Control Studies; D017077:Culture Media, Conditioned / Q000378:metabolism; D016207:Cytokines / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010974:Platelet Aggregation; D011237:Predictive Value of Tests; D040081:Protein Array Analysis; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D013030:Spain; D046509:Tissue Culture Techniques; D014057:Tomography, X-Ray Computed; D015854:Up-Regulation
D015415:Biomarkers; D017077:Culture Media, Conditioned; D016207:Cytokines; C032231:IGFBP1 protein, human; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I