A proteomic analysis of C-reactive protein stimulated THP-1 monocytes

• Main Authors: Ayhan Mustafa, Lancaster Graeme I, Oliva Karen, Habersberger Jonathon, Eisenhardt Steffen U, Woollard Kevin J, Bannasch Holger, Rice Greg E, Peter Karlheinz
• Format: Article
• Language: English
• Published: BMC 2011-01-01
• Series: Proteome Science
• Online Access: http://www.proteomesci.com/content/9/1/1

<p>Abstract</p> <p>Background</p> <p>C-reactive protein (CRP) is a predictor of cardiovascular risk. It circulates as a pentameric protein in plasma. Recently, a potential dissociation mechanism from the disc-shaped pentameric CRP (pCRP) into single monomers (monomeric or mCRP) has been described. It has been shown that mCRP has strong pro-inflammatory effects on monocytes. To further define the role of mCRP in determining monocyte phenotype, the effects of CRP isoforms on THP-1 protein expression profiles were determined. The hypothesis to be tested was that mCRP induces specific changes in the protein expression profile of THP-1 cells that differ from that of pCRP.</p> <p>Methods</p> <p>Protein cell lysates from control and mCRP, pCRP or LPS-treated THP-1 cells were displayed using 2-dimensional SDS PAGE and compared. Differentially expressed proteins were identified by MALDI-TOF MS and confirmed by Western blotting.</p> <p>Results</p> <p>mCRP significantly up-regulates ubiquitin-activating enzyme E1, a member of the ubiquitin-proteasome system in THP-1 monocytes. Furthermore, HSP 70, alpha-actinin-4 (ACTN4) and alpha-enolase/enolase 1 were upregulated. The proteomic profile of LPS and pCRP treated monocytes differ significantly from that of mCRP.</p> <p>Conclusion</p> <p>The data obtained in this study support the hypothesis that isoform-specific effects of CRP may differentially regulate the phenotype of monocytes.</p>