KLF2 and KLF4 control endothelial identity and vascular integrity
Panjamaporn Sangwung, … , Hanjoong Jo, Mukesh K. Jain
Panjamaporn Sangwung, … , Hanjoong Jo, Mukesh K. Jain
Published February 23, 2017
Citation Information: JCI Insight. 2017;2(4):e91700. https://doi.org/10.1172/jci.insight.91700.
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Research Article Vascular biology

KLF2 and KLF4 control endothelial identity and vascular integrity

Abstract

Maintenance of vascular integrity in the adult animal is needed for survival, and it is 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.

Authors

Panjamaporn Sangwung, Guangjin Zhou, Lalitha Nayak, E. Ricky Chan, Sandeep Kumar, Dong-Won Kang, Rongli Zhang, Xudong Liao, Yuan Lu, Keiki Sugi, Hisashi Fujioka, Hong Shi, Stephanie D. Lapping, Chandra C. Ghosh, Sarah J. Higgins, Samir M. Parikh, Hanjoong Jo, Mukesh K. Jain

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Figure 2

Endothelial-specific deletion of Klf2 and Klf4 leads to vascular leak and systemic coagulopathy.

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Endothelial-specific deletion of Klf2 and Klf4 leads to vascular leak an...
(A, top) Representative images of brain eosin staining show erythrocyte leakage (white arrows) in extravascular tissues at day 6 after tamoxifen (n = 3 per genotype). Scale bar: 50 μm. (A, middle) Representative electron microscopic (EM) images of brain indicate discontinuity of endothelial monolayer in the EC-DKO mice at day 6 after tamoxifen (n = 3–4 per genotype). Scale bar: 2 μm. Endothelial cells (EC), red arrowheads; vessel lumen, black arrowheads. The box outlined in red is shown at high magnification in the inset. Scale bar: 1 μm. (A, bottom) Representative images of Evans blue vascular permeability assay of the brain at day 6 after tamoxifen (n = 7–8 per genotype). (B) Relative mRNA expression levels of endothelial tight and adherens junction genes in primary cardiac microvascular ECs 6 days after tamoxifen injection (n = 3–5 per genotype, each sample was pooled from 2 mice). (C) Circulating angiopoietin-2 protein levels before and after tamoxifen (n = 6–8 per genotype). (D) White blood cell (WBC), red blood cell (RBC), and blood platelet (PLT) counts at day 6 after tamoxifen (n = 25–29 per genotype). (E) Representative images of blood smear in CRE and EC-DKO mice (n = 3 per genotype). White arrows indicate erythrocyte fragmentation. Scale bar: 50 μm. The box outlined in red is shown at high magnification in the inset. (F) Extrinsic and intrinsic pathway coagulation assays (n = 11–13 per genotype). PT, prothrombin; aPTT, activated partial thromboplastin times. (G) Plasma D-dimer levels at day 6 after tamoxifen (CRE, n = 5; EC-DKO, n = 6). CRE, Cdh5(PAC)-Ert2cre; EC-DKO, EC-specific Klf2 and Klf4 double knockout. Data are presented as mean ± SEM. *P < 0.05; **P < 0.01. Two-way ANOVA with Tukey’s post-hoc test and 2-tailed Student’s t test.