Insulin-like growth factor 1 opposes the effects of C-reactive protein on endothelial cell activation

Emerging evidence demonstrates that high plasma C-reactive protein (CRP) levels or low plasma insulin-like growth factor 1 (IGF-1) concentrations may be separately associated with the increased risk of coronary artery disease or myocardial infarction. Interestingly, animal model studies and epidemiological investigations indicate that circulating IGF-1 and CRP levels have an inverse correlation. The present study aims to evaluate if IGF-1 can directly oppose the effects of CRP on endothelial cell (EC) activation. We found that IGF-1 rescues endothelial nitric oxide synthase activity and decreases the release of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 from ECs. We also showed that IGF-1 antagonizes the effects of CRP by activating the PI3K/Akt pathway and suppressing the JNK/c-Jun and MAPK p38/ATF2 signaling pathways, rather than inhibiting ERK1/2 activity. These findings provide evidence of the physiopathological mechanisms of endothelial activation and novel insights into the protective properties of IGF-1.