Cardiac microvascular endothelail cells of EC-KLF2 and/or KLF4 knockout mice at day 6 post-tamoxifen

Maintenance of vascular integrity in the adult animal is needed for survival and critically dependent on the endothelial lining, which controls barrier function, blood fluidity, and flow dynamics. However, nodal regulators that coordinate endothelial identity and function in the adult animal remain poorly characterized. Here we show that endothelial KLF2 and KLF4 control a large segment of the endothelial transcriptome thereby affecting virtually all key endothelial functions. Inducible endothelial-specific deletion of Klf2 and/or Klf4 reveals that a single allele of either gene is sufficient for survival, but absence of both (EC-DKO) results in acute death from myocardial infarction, heart failure, and stroke. EC-DKO animals exhibit profound compromise in vascular integrity and profound dysregulation of the coagulation system. Collectively, these studies establish an absolute requirement for KLF2/4 for maintenance of endothelial and vascular integrity in the adult animal. Eight-to-ten-week old mice were intraperitoneally injected with tamoxifen to trigger endothelial-specific gene deletion of KLF2 and/or KLF4. At day 6 post-injection, endothelial cells were isolated from the heart and total RNA was purified.