Epigenetic Reactivation of CNS Endothelial Developmental Programs Triggers Adult Brain Angiogenesis, Promotes Post-Stroke Revascularization and Neuroregeneration.

We identified the role of brain endothelial cell Hdac2 and Ezh2 mediated epigenetic mechanism in maintaining blood brain barrier in adult mice. Also, we we studied the impact of reactivation of brain endothelial cell Wnt/β-catenin signaling in adult mice.We evaluated derepression of Hdac2 mediated epigenetic mechanism in imice model of schemic stroke. Ultra-low mRNA sequencing of FACS sorted CD31+ve/CD41-ve/CD45-ve adult mice brain cortical endothelial cells isolated from WT, Hdac2 ECKO, Ezh2 ECKO and β-catenin GOF mice. For endothelial specific deletion of Hdac2 and Ezh2, or β-catenin constitutive activation, Hdac2lox/lox:Cdh5CreERT2, Ezh2lox/lox:Cdh5CreERT2 and Ctnnb1lox/lox:Cdh5CreERT2 mice were treated with five doses of Tamoxifen (75mg/Kg body weight) and brains were harvested after 2 months.

本研究明确了脑内皮细胞中组蛋白去乙酰化酶2（Hdac2）与zeste基因增强子同源物2（Ezh2）介导的表观遗传机制在维持成年小鼠血脑屏障（Blood Brain Barrier）中的作用。此外，本研究还探究了成年小鼠脑内皮细胞Wnt/β-连环蛋白信号通路再激活的生物学影响。我们评估了Hdac2介导的表观遗传机制去阻遏在缺血性脑卒中小鼠模型中的效应。本研究对从野生型（Wild Type, WT）、Hdac2内皮特异性敲除（Hdac2 ECKO）、Ezh2内皮特异性敲除（Ezh2 ECKO）及β-连环蛋白功能获得型（β-catenin GOF）小鼠中分离的、经荧光激活细胞分选（Fluorescence Activated Cell Sorting, FACS）得到的CD31阳性/CD41阴性/CD45阴性成年小鼠大脑皮层内皮细胞开展了超低通量mRNA测序。为实现内皮细胞特异性敲除Hdac2和Ezh2，或组成型激活β-连环蛋白，我们对Hdac2lox/lox:Cdh5CreERT2、Ezh2lox/lox:Cdh5CreERT2及Ctnnb1lox/lox:Cdh5CreERT2小鼠给予5剂他莫昔芬（75mg/kg体重）处理，并于给药2个月后采集脑组织。