The shear stress-induced transcription factor KLF2 affects dynamics and angiopoietin-2 content of Weibel-Palade bodies

• Published in: PloS one Vol. 7; no. 6; p. e38399
• Main Authors: van Agtmaal, Ellen L, Bierings, Ruben, Dragt, Bieuwke S, Leyen, Thomas A, Fernandez-Borja, Mar, Horrevoets, Anton J G, Voorberg, Jan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.06.2012; Public Library of Science (PLoS)
• Subjects: Angiogenesis; Angiopoietin; Angiopoietin-2 - biosynthesis; Biology; Cell culture; Cells, Cultured; Clustering; Cyclic adenosine monophosphate; Cytokines - genetics; Cytokines - secretion; Endothelial Cells; Endothelium; Epinephrine; Gene expression; Gene Expression Regulation; Gene regulation; Homeostasis; Humans; Immunocytochemistry; Immunoglobulins; Immunology; Inflammation; Interleukin 6; Interleukin 8; Kinases; Krueppel-like factor; Kruppel-Like Transcription Factors - biosynthesis; Kruppel-Like Transcription Factors - genetics; Laboratories; Lung Kruppel-like factor; Mechanical stimuli; Medicine; Morphogenesis; Peripheral blood; Physiological aspects; Proteins; Shear Strength; Shear stress; Shear stresses; Stress, Physiological; Trends; Weibel-Palade Bodies - genetics; Weibel-Palade Bodies - metabolism; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0038399

The shear-stress induced transcription factor KLF2 has been shown to induce an atheroprotective phenotype in endothelial cells (EC) that are exposed to prolonged laminar shear. In this study we characterized the effect of the shear stress-induced transcription factor KLF2 on regulation and composition of Weibel-Palade bodies (WPBs) using peripheral blood derived ECs. Lentiviral expression of KLF2 resulted in a 4.5 fold increase in the number of WPBs per cell when compared to mock-transduced endothelial cells. Unexpectedly, the average length of WPBs was significantly reduced: in mock-transduced endothelial cells WPBs had an average length of 1.7 µm versus 1.3 µm in KLF2 expressing cells. Expression of KLF2 abolished the perinuclear clustering of WPBs observed following stimulation with cAMP-raising agonists such as epinephrine. Immunocytochemistry revealed that WPBs of KLF2 expressing ECs were positive for IL-6 and IL-8 (after their upregulation with IL-1β) but lacked angiopoietin-2 (Ang2), a regular component of WPBs. Stimulus-induced secretion of Ang2 in KLF2 expressing ECs was greatly reduced and IL-8 secretion was significantly lower. These data suggest that KLF2 expression leads to a change in size and composition of the regulated secretory compartment of endothelial cells and alters its response to physiological stimuli.