The transcriptional regulator CCCTC-binding factor limits oxidative stress in endothelial cells

The CCCTC-binding factor (CTCF) is a versatile transcriptional regulator required for embryogenesis, but its function in vascular development or in diseases with a vascular component is poorly understood. Here, we found that endothelial Ctcf is essential for mouse vascular development and limits accumulation of reactive oxygen species (ROS). Conditional knockout of Ctcf in endothelial progenitors and their descendants affected embryonic growth, and caused lethality at embryonic day 10.5 owing to defective yolk sac and placental vascular development. Analysis of global gene expression revealed Frataxin (Fxn), the gene mutated in Friedreich's ataxia (FRDA), as the most strongly downregulated gene in Ctcfdeficient placental endothelial cells. Moreover, in vitro reporter assays showed that Ctcf activates the Fxn promoter in endothelial cells. Reactive oxygen species (ROS) are known to accumulate in the endothelium of FRDA patients. Importantly, Ctcf deficiency induced ROS-mediated DNA damage in endothelial cells in vitro, and in placental endothelium in vivo. Taken together, our findings indicate that, Ctcf promotes vascular development, and limits oxidative stress in endothelial cells, perhaps through activation of Fxn transcription. These results reveal a function for a Ctcf–Fxn transcriptional pathway in vascular development, and also suggest a potential mechanism for endothelial dysfunction in FRDA. Overall design: Examination of transcriptome profiles of placental endothelial cells isolated from wildtype or ctcf defecient endothelial cells at E9.5

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Roy AR, Ahmed A, DiStefano PV, Chi L, Khyzha N, Galjart N, Wilson MD, Fish JE, Delgado-Olguín P