TY - JOUR
T1 - Circulating microparticles generate and transport monomeric C-reactive protein in patients with myocardial infarction
AU - Habersberger, Jonathon Peter
AU - Strang, Frederik
AU - Scheichl, Amelie
AU - Htun, Nay
AU - Bassler, Nicole
AU - Merivirta, Ruusu-Maaria
AU - Diehl, Philipp
AU - Krippner, Guy Yeoman
AU - Meikle, Peter J
AU - Eisenhardt, Steffen U
AU - Meredith, Ian T
AU - Peter, Karlheinz
PY - 2012
Y1 - 2012
N2 - AIMS: Elevated serum C-reactive protein (CRP) following myocardial infarction (MI) is associated with poor outcomes. Although animal studies have indicated a direct pathogenic role of CRP, the mechanism underlying this remains elusive. Dissociation of pentameric CRP (pCRP) into pro-inflammatory monomers (mCRP) may directly link CRP to inflammation. We investigated whether cellular microparticles (MPs) can convert pCRP to mCRP and transport mCRP following MI. METHODS AND RESULTS: MPs enriched in lysophosphatidylcholine were obtained from cell cultures and patient whole-blood samples collected following acute MI and control groups. Samples were analysed by native western blotting and flow cytometry. MPs were loaded with mCRP in vitro and incubated with endothelial cells prior to staining with monoclonal antibodies. In vitro experiments demonstrated that MPs were capable of converting pCRP to mCRP which could be inhibited by the anti-CRP compound 1,6 bis-phosphocholine. Significantly more mCRP was detected on MPs from patients following MI compared with control groups by western blotting and flow cytometry (P = 0.0005 for association). MPs containing mCRP were able to bind to the surface of endothelial cells and generate pro-inflammatory signals in vitro, suggesting a possible role of MPs in transport and delivery of pro-inflammatory mCRP in vascular disease. CONCLUSION: Circulating MPs can convert pCRP to pro-inflammatory mCRP in patients following MI, demonstrating for the first time mCRP generation in vivo and its detection in circulating blood. MPs can bind to cell membranes and transfer mCRP to the cell surface, suggesting a possible mCRP transport/delivery role of MPs in the circulation.
AB - AIMS: Elevated serum C-reactive protein (CRP) following myocardial infarction (MI) is associated with poor outcomes. Although animal studies have indicated a direct pathogenic role of CRP, the mechanism underlying this remains elusive. Dissociation of pentameric CRP (pCRP) into pro-inflammatory monomers (mCRP) may directly link CRP to inflammation. We investigated whether cellular microparticles (MPs) can convert pCRP to mCRP and transport mCRP following MI. METHODS AND RESULTS: MPs enriched in lysophosphatidylcholine were obtained from cell cultures and patient whole-blood samples collected following acute MI and control groups. Samples were analysed by native western blotting and flow cytometry. MPs were loaded with mCRP in vitro and incubated with endothelial cells prior to staining with monoclonal antibodies. In vitro experiments demonstrated that MPs were capable of converting pCRP to mCRP which could be inhibited by the anti-CRP compound 1,6 bis-phosphocholine. Significantly more mCRP was detected on MPs from patients following MI compared with control groups by western blotting and flow cytometry (P = 0.0005 for association). MPs containing mCRP were able to bind to the surface of endothelial cells and generate pro-inflammatory signals in vitro, suggesting a possible role of MPs in transport and delivery of pro-inflammatory mCRP in vascular disease. CONCLUSION: Circulating MPs can convert pCRP to pro-inflammatory mCRP in patients following MI, demonstrating for the first time mCRP generation in vivo and its detection in circulating blood. MPs can bind to cell membranes and transfer mCRP to the cell surface, suggesting a possible mCRP transport/delivery role of MPs in the circulation.
UR - http://www.ncbi.nlm.nih.gov/pubmed/22798388
U2 - 10.1093/cvr/cvs237
DO - 10.1093/cvr/cvs237
M3 - Article
SN - 0008-6363
VL - 96
SP - 64
EP - 72
JO - Cardiovascular Research
JF - Cardiovascular Research
IS - 1
ER -