Liu Ying, Mo Jiake, Guo Zi, Zhang Jiaqi, Tang Weian, Meng Xubiao, Luo Yufang, Wang Fang, Mo Zhaohui
Department of Endocrinology, Department of Endocrinology, The Third Xiangya Hospital of Central South University and Diabetic Foot Research Center of Central South University, Changsha, 410013, Hunan Province, China.
Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, 06510, USA.
Angiogenesis. 2025 Aug 5;28(4):42. doi: 10.1007/s10456-025-09998-0.
Epigenetics is increasingly recognized as a crucial factor in angiogenesis. Ubiquitin-like with PHD and RING Finger Domains 1 (UHRF1) is an important epigenetic regulatory protein involved in regulating cellular life processes, developing many diseases. However, its potential role in regulating embryonic vascular development and postnatal angiogenesis is unclear. Our study found that endothelial cell-specific UHRF1 knockout mice showed obvious developmental disorders at the embryonic stage (E11.5-15.5), including impaired development of the individual embryo size and organs, sparse vascularity in the yolk sac, or even death. In the lower limb ischemia model, UHRF1 expression in ischemic muscle tissues of mice is proportionate to the regeneration of blood vessels. To confirm the specific inhibition of UHRF1, we transfected an adeno-associated virus serotype 9 which inserted a TIE-2 promoter and mediated the delivery of short hairpin RNA (AAV9-TIE-2-shUHRF1) into mouse vascular endothelial cells to knock down UHRF1 specifically. We observed that the knockdown of UHRF1 in endothelial cells results in poorer lower limb perfusion in mice. Mechanically, UHRF1 knockdown decreased the tube-forming capacity of ECFCs, whereas overexpression of UHRF1 by diabetic ECFCs where UHRF1 expression is typically downregulated significantly increased the tube-forming capacity of the cells. RNAseq and related bioinformatics analyses showed that differentially expressed genes (DEGs) were mainly involved in angiogenesis-related pathways. The results of qPCR and western blot showed that the protein and mRNA levels of angiogenesis-related factors (VEGF, PDGF, and ANGPT1), as well as vascular endothelial surface marker molecules (VEGFR2, CD31, and c-Kit), were down-regulated accordingly. Furthermore, ChIP experiments showed that UHRF1 was able to bind the promoters of VEGFR2 and CD31, affecting the levels of histone-methylated protein (H3K4me3 and H3K27me3) enriched in the promoter region. However, the expression of CD31 and VEGFR2 can be reversed separately after the transformation of different histone-methylated protein levels (H3K4me3 and H3K27me3). Taken together, UHRF1 may regulate angiogenic gene expression and vascular endothelial cell differentiation through epigenetic mechanisms and is essential for angiogenesis.
表观遗传学日益被认为是血管生成的关键因素。含PHD和RING指结构域的类泛素1（UHRF1）是一种重要的表观遗传调节蛋白，参与调节细胞生命过程，与多种疾病的发生发展相关。然而，其在调节胚胎血管发育和出生后血管生成中的潜在作用尚不清楚。我们的研究发现，内皮细胞特异性UHRF1基因敲除小鼠在胚胎期（E11.5 - 15.5）表现出明显的发育障碍，包括个体胚胎大小和器官发育受损、卵黄囊血管稀疏，甚至死亡。在下肢缺血模型中，小鼠缺血肌肉组织中UHRF1的表达与血管再生成正比。为了证实对UHRF1的特异性抑制，我们将一种插入TIE - 2启动子并介导短发夹RNA传递的9型腺相关病毒（AAV9 - TIE - 2 - shUHRF1）转染到小鼠血管内皮细胞中，以特异性敲低UHRF1。我们观察到，内皮细胞中UHRF1的敲低导致小鼠下肢灌注较差。机制上，UHRF1的敲低降低了内皮祖细胞的管腔形成能力，而在UHRF1表达通常下调的糖尿病内皮祖细胞中过表达UHRF1则显著增加了细胞的管腔形成能力。RNA测序和相关生物信息学分析表明，差异表达基因（DEG）主要参与血管生成相关途径。qPCR和蛋白质印迹结果显示，血管生成相关因子（VEGF、PDGF和ANGPT1）以及血管内皮表面标志物分子（VEGFR2、CD31和c - Kit）的蛋白质和mRNA水平相应下调。此外，染色质免疫沉淀实验表明，UHRF1能够结合VEGFR2和CD31的启动子，影响启动子区域富集的组蛋白甲基化蛋白（H3K4me3和H3K27me3）水平。然而，在不同组蛋白甲基化蛋白水平（H3K4me3和H3K27me3）改变后，CD31和VEGFR2的表达可分别逆转。综上所述，UHRF1可能通过表观遗传机制调节血管生成基因表达和血管内皮细胞分化，对血管生成至关重要。
