Transcriptome profiling of murine aortic endothelium deleted for the transcription factor Mef2c

Laminar flow on endothelial cells in vitro activates MEF2 transcription factors to induce expression of atheroprotective genes. Here we sought to establish in vivo MEF2 functions in the endothelium through endothelial-specific deletion of Mef2c. Our results show that endothelial Mef2c regulates migration of vascular smooth muscle from the tunica media into the intima through fenestrations in the internal elastic lamina. Moreover, Mef2c regulates actin stress fiber formation in the endothelium. To investigate Mef2c-dependent targets in the endothelium, we perform transcriptome profiling on RNA isolated from the aortic endothelium with or without Mef2c deletion. Endothelial-specific, inducible-deletion of Mef2c was mediated by Cdh5-CreERT2 through 5 daily tamoxifen injections (Mef2cCdh5EKO) in 10 weeks old mice. Littermates who received vehicle injection served as controls. Thoracic aortas from these mice were harvest 14 days after the first injection. Endothelial RNA from individual aortas was isolated by flushing TRIzol through the aortic lumen and processed for Mouse Transcriptome Array 1.0 (Affymetrix). Each sample was from a single aorta.