Objectives: Endoglin (CD105, TGF-βRIII receptor), is essential for proper function of endothelium, but also participate in inflammatory infiltration of leukocytes. We hypothesized that membrane endoglin participates in 7-ketocholesterol (7K) induced development of endothelial dysfunction. 

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 and Selectins were evaluated by flow cytometry analysis. Protein expression and intracellular 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. Inhibition of either KLF6 (siRNA), RELA (PHA-408) or NR1H3 (2-hydroxypropyl-β-cyclodextrin) results in inhibition of 7K induced increase of endoglin expression. 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: We demonstrated that 7K is able to induce inflammation and increase endoglin expression in endothelial cells via KLF6, RELA and NR1H3 transcription genes. We also demonstrated 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 1158413C, 1216217, SVV/2017/260414 and AZV CR 17-31754A.

02 - ENDOGLIN PLAYS ROLE IN CHOLESTEROL-INDUCED ENDOTHELIAL DYSFUNCTION AND MONOCYTE TRAFFICKING IN HUMAN AORTIC ENDOTHELIAL CELLS