Background and Aims

Endoglin (CD105, TGF-βRIII receptor), is essential for proper function of endothelium, but also participate in inflammatory infiltration of monocytes. We hypothesized that endoglin play crucial role in monocyte adhesion and transmigration via endothelial cells when exposed to oxysterol simulating oxidized LDL effects in atherogenesis.

Methods

HAECs were exposed to 7K (5, 10ug/mL)for 12 hours. Gene expression (endoglin, KLF6, RELA (NF-κB p65), NR1H3 (LXR), ICAM-1) was evaluated using qRT-PCR. Protein levels of endoglin, ICAM-1 andP/E-selectinswere evaluated by flow cytometry analysis. Protein levels and localization of RELA, eNOS, p-eNOS was evaluated using confocal fluorescent microscopy.

Results

Gene expression and protein levels of endoglin, eNOS, p-eNOS and cell adhesion molecules (ICAM-1, E/P-selectin) as well as transcription genes regulating endoglin expression were significantly increased after 12h premedication with 7K compared to non-treated cells. 7K was able to increase adhesion and transmigration of THP-1 monocytes, trough endothelial cells monolayer (HAECs). Silencing of endoglin in HAECs by siENG inhibited adhesion and transmigration of THP-1 monocytes.

Conclusions

In this study, we demonstrated that 7K is able to induce inflammation and increase endoglin expression in endothelial cells via activation of KLF6, RELA and NR1H3 transcription genes. Moreover, we showed that 7K induced adhesion and transmigration of monocytes trough endothelial monolayer depends on the expression of endoglin suggesting that endoglin might play crucial role in cholesterol (oxysterol) induced endothelial dysfunction.

This work was supported by project EFSA-CDN (No. CZ.02.1.01/0.0/0.0/16_019/0000841) co-funded by ERDF, GAUK 1216217,SVV/2017/260414 and AZV CR 17-31754A.