BACKGROUND

Endothelial dysfunction is essential in pathogenesis of numerous chronic diseases, including cardiovascular ones, and precedes clinical manifestations. Among numerous causes of endothelial dysfunction, chronic inflammation, including latent microvascular inflammation, is important regarding exposure of endothelial cells to pro-inflammatory factors. Although the role of inflammation in endothelial dysfunction has been studied for several years, many questions remain unanswered regarding molecular mechanisms underlying the effects of specific cytokines on endothelial cells.

OBJECTIVE. T

O investigate the long-term effects of pro-inflammatory factors TNF-a and IL-1b on expression profile, intracellular signaling and angiogenic properties of endothelial cells.

MATERIAL AND METHODS

We used a 2D model of angiogenesis based on co-culture of human umbilical vein endothelial cells (HUVECs) and mesenchymal stromal cells. Gene expression was analyzed using real-time PCR. Proteomic analysis of kinase phosphoforms was conducted to evaluate intracellular signaling in HUVECs in response to IL-1b and TNF-a exposure.

RESULTS

Pro-inflammatory cytokines reduced angiogenic properties of endothelial cells after 2—4-day exposure. The effect of IL-1b was even more obvious. Additionally, IL-1b stimulated activation of genes associated with endothelial-mesenchymal transition largely than TNF-a. Endothelial-mesenchymal transition contributes to myocardial perivascular fibrosis. Both cytokines differentially affected CREB-mediated intracellular signaling.

CONCLUSION

Prolonged exposure of endothelial cells to pro-inflammatory factors TNF-a and IL-1b impairs their angiogenic properties. Notably, the effect of IL-1b was clearer. This is likely explained by different effects of these cytokines on expression of EnMT-associated genes and CREB-mediated intracellular signaling.