Background: Proliferation of the vasa vasorum has been implicated in the pathogenesis of atherosclerosis, and the vasa vasorum is closely associated with resident stem cells within the vasculature. C-reactive protein (CRP) is positively correlated with cardiovascular disease risk, and our previous study demonstrated that it induces inflammatory reactions of perivascular adipose tissue by targeting adipocytes.
Methods: Here we investigated whether CRP affected the proliferation and proangiogenic paracrine activity of adipose-derived stem cells (ADSCs), which may contribute to vasa vasorum angiogenesis.
Results: We found that CRP did not affect ADSC apoptosis, cell cycle, or proliferation but did increase their migration by activating the PI3K/Akt pathway. Our results demonstrated that CRP can upregulate vascular endothelial growth factor-A (VEGF-A) expression by activating hypoxia inducible factor-1α (HIF-1α) in ADSCs, which significantly increased tube formation on Matrigel and functional vessels in the Matrigel plug angiogenesis assay. The inhibition of CRP-activated phosphorylation of ERK and Akt can suppress CRP-stimulated HIF-1α activation and VEGF-A expression. CRP can also stimulate proteolytic activity of matrix metalloproteinase-2 in ADSCs. Furthermore, CRP binds activating CD64 on ADSCs, rather than CD16/32.
Conclusion: Our findings implicate that CRP might play a role in vasa vasorum growth by activating the proangiogenic activity of ADSCs.
Keywords: Adipose-deprived stem cell; Angiogenesis; C-reactive protein; Hypoxia-inducible factor-1α; Vascular endothelial growth factor.