NOGOB receptor deficiency increases cerebrovascular permeability and hemorrhage via impairing histone acetylation–mediated CCM1/2 expression
Zhi Fang, … , Wenquan Hu, Qing Robert Miao
Zhi Fang, … , Wenquan Hu, Qing Robert Miao
Published March 22, 2022
Citation Information: J Clin Invest. 2022;132(9):e151382. https://doi.org/10.1172/JCI151382.
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Research Article Angiogenesis Vascular biology

NOGOB receptor deficiency increases cerebrovascular permeability and hemorrhage via impairing histone acetylation–mediated CCM1/2 expression

Abstract

The loss function of cerebral cavernous malformation (CCM) genes leads to most CCM lesions characterized by enlarged leaking vascular lesions in the brain. Although we previously showed that NOGOB receptor (NGBR) knockout in endothelial cells (ECs) results in cerebrovascular lesions in the mouse embryo, the molecular mechanism by which NGBR regulates CCM1/2 expression has not been elucidated. Here, we show that genetic depletion of Ngbr in ECs at both postnatal and adult stages results in CCM1/2 expression deficiency and cerebrovascular lesions such as enlarged vessels, blood-brain-barrier hyperpermeability, and cerebral hemorrhage. To reveal the molecular mechanism, we used RNA-sequencing analysis to examine changes in the transcriptome. Surprisingly, we found that the acetyltransferase HBO1 and histone acetylation were downregulated in NGBR-deficient ECs. The mechanistic studies elucidated that NGBR is required for maintaining the expression of CCM1/2 in ECs via HBO1-mediated histone acetylation. ChIP-qPCR data further demonstrated that loss of NGBR impairs the binding of HBO1 and acetylated histone H4K5 and H4K12 on the promotor of the CCM1 and CCM2 genes. Our findings on epigenetic regulation of CCM1 and CCM2 that is modulated by NGBR and HBO1-mediated histone H4 acetylation provide a perspective on the pathogenesis of sporadic CCMs.

Authors

Zhi Fang, Xiaoran Sun, Xiang Wang, Ji Ma, Thomas Palaia, Ujala Rana, Benjamin Miao, Louis Ragolia, Wenquan Hu, Qing Robert Miao

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Figure 4

CCM1/2 overexpression ameliorated NGBR deficiency–induced endothelial dysfunction in vitro.

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CCM1/2 overexpression ameliorated NGBR deficiency–induced endothelial d...
(A) The overexpression of CCM1 and CCM2 genes using lentiviruses ameliorated NGBR deficiency–promoted HBMVEC hyperpermeability, which was determined by EC-monolayer permeability assay. Statistical significance was determined by 1-way ANOVA and Dunnett’s post hoc test. Data are presented as mean ± SD. ***P < 0.001 versus siCtrl- and lentivirus vector control–treated (lenti-vector) group; ###P < 0.001 versus siNGBR- and lenti-vector–treated group; †††P < 0.001 versus siNGBR- and CCM1 lentivirus–treated (lenti-CCM1) group; §§P < 0.01 versus siNGBR- and CCM2 lentivirus–treated (lenti-CCM2) group. n = 4 samples per group. (B) Immunofluorescent staining showing that overexpression of CCM1 and CCM2 synergistically improved NGBR deficiency–induced AJ (VE-cadherin) and TJ (ZO-1) disruption. Scale bars: 10 μm. (C) Overexpression of CCM1 and CCM2 genes resulted in a synergistic decrease in phos-MLC immunofluorescent staining in NGBR-deficient HBMVECs. Scale bars: 20 μm. (D and E) Western blot and quantification results showing that overexpression of CCM1 and CCM2 synergistically diminished the induction of RhoA and phos-MLC in NGBR-deficient HBMVECs. Data are presented as mean ± SD, n = 3 samples per group. Statistical significance was determined by 1-way ANOVA with Dunnett’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.001 versus control siRNA–and lenti-vector–treated HBMVECs; ###P < 0.001 versus NGBR siRNA– and lenti-vector–treated HBMVECs.