Rodríguez Cristina, Sobrino Tomás, Agulla Jesús, Bobo-Jiménez Verónica, Ramos-Araque María E, Duarte Juan J, Gómez-Sánchez José C, Bolaños Juan P, Castillo José, Almeida Ángeles
Institute of Biomedical Research of Salamanca, University Hospital of Salamanca-University of Salamanca, Salamanca, Spain.
Institute of Functional Biology and Genomics, University of Salamanca-CSIC, Salamanca, Spain.
Cell Death Differ. 2017 Jan;24(1):144-154. doi: 10.1038/cdd.2016.109. Epub 2016 Oct 21.
Intracerebral hemorrhage (ICH) is a devastating subtype of stroke that lacks effective therapy and reliable prognosis. Neovascularization following ICH is an essential compensatory response that mediates brain repair and modulates the clinical outcome of stroke patients. However, the mechanism that dictates this process is unknown. Bone marrow-derived endothelial progenitor cells (EPCs) promote endothelial repair and contribute to ischemia-induced neovascularization. The human Tp53 gene harbors a common single-nucleotide polymorphism (SNP) at codon 72, which yields an arginine-to-proline amino-acidic substitution (Arg72Pro) that modulates the apoptotic activity of the p53 protein. Previously, we found that this SNP controls neuronal susceptibility to ischemia-induced apoptosis in vitro. Here, we evaluated the impact of the Tp53 Arg72Pro SNP on vascular repair and functional recovery after ICH. We first analyzed EPC mobilization and functional outcome based on the modified Rankin scale scores in a hospital-based cohort of 78 patients with non-traumatic ICH. Patients harboring the Pro allele of the Tp53 Arg72Pro SNP showed higher levels of circulating EPC-containing CD34 cells, EPC-mobilizing cytokines - vascular endothelial growth factor and stromal cell-derived factor-1α - and good functional outcome following ICH, when compared with the homozygous Arg allele patients, which is compatible with increased neovascularization. To assess directly whether Tp53 Arg72Pro SNP regulated neovascularization after ICH, we used the humanized Tp53 Arg72Pro knock-in mice, which were subjected to the collagenase-induced ICH. The brain endothelial cells of the Pro allele-carrying mice were highly resistant to ICH-mediated apoptosis, which facilitated cytokine-mediated EPC mobilization, cerebrovascular repair and functional recovery. However, these processes were not observed in the Arg allele-carrying mice. These results reveal that the Tp53 Arg72Pro SNP determines neovascularization, brain repair and neurological recovery after ICH. This study is the first in which the Pro allele of Tp53 is linked to vascular repair and ability to functionally recover from stroke.
脑出血（ICH）是一种破坏性的中风亚型，缺乏有效的治疗方法和可靠的预后。脑出血后的新生血管形成是一种重要的代偿反应，可介导脑修复并调节中风患者的临床结局。然而，决定这一过程的机制尚不清楚。骨髓来源的内皮祖细胞（EPCs）促进内皮修复并有助于缺血诱导的新生血管形成。人类Tp53基因在第72密码子处存在一个常见的单核苷酸多态性（SNP），该多态性导致精氨酸到脯氨酸的氨基酸替换（Arg72Pro），从而调节p53蛋白的凋亡活性。此前，我们发现该SNP在体外控制神经元对缺血诱导凋亡的易感性。在此，我们评估了Tp53 Arg72Pro SNP对脑出血后血管修复和功能恢复的影响。我们首先在一个基于医院的队列中，对78例非创伤性脑出血患者，根据改良Rankin量表评分分析EPC动员和功能结局。与纯合子Arg等位基因患者相比，携带Tp53 Arg72Pro SNP的Pro等位基因的患者循环中含EPC的CD34细胞、EPC动员细胞因子——血管内皮生长因子和基质细胞衍生因子-1α水平更高，脑出血后功能结局良好，这与新生血管形成增加相一致。为了直接评估Tp53 Arg72Pro SNP是否调节脑出血后的新生血管形成，我们使用了人源化Tp53 Arg72Pro基因敲入小鼠，对其进行胶原酶诱导的脑出血。携带Pro等位基因的小鼠的脑内皮细胞对脑出血介导的凋亡具有高度抗性，这促进了细胞因子介导的EPC动员、脑血管修复和功能恢复。然而，在携带Arg等位基因的小鼠中未观察到这些过程。这些结果表明，Tp53 Arg72Pro SNP决定脑出血后的新生血管形成、脑修复和神经功能恢复。本研究首次表明Tp53的Pro等位基因与血管修复及从中风功能恢复的能力有关。
