Mani Arul M, Lamin Victor, Peach Ronan C, Friesen Eli H, Wong Thomas, Singh Madhu V, Dokun Ayotunde O
Division of Endocrinology and Metabolism, Carver College of Medicine University of Iowa Iowa City IA USA.
Fraternal Order of Eagles Diabetes Research Centre, Carver College of Medicine University of Iowa Iowa City IA USA.
J Am Heart Assoc. 2024 Dec 3;13(23):e035923. doi: 10.1161/JAHA.124.035923. Epub 2024 Nov 27.
Peripheral arterial disease affects >200 million people worldwide and is characterized by impaired blood flow to the lower extremities. There are no effective medical treatments available. Using the mouse hind-limb ischemia model and miRNA sequencing, we identified a novel miRNA, miR-6236, whose expression significantly elevated in ischemic mouse limbs compared with nonischemic limbs. The role of miR-6236 in general or in postischemic angiogenesis is not known. Here we describe its role using in vivo and in vitro models of peripheral arterial disease.
In primary mouse and human endothelial cells, we studied the effect of simulated ischemia on miR-6236 expression and assessed its role in cell viability, apoptosis, migration, and tube formation during ischemia. Furthermore, we developed miR-6236 null mice and tested its role in postischemic perfusion recovery using the hind-limb ischemia model. Lastly, using bioinformatics and gene expression analysis, we identified putative angiogenic miR-6236 targets. In vitro simulated ischemia-enhanced miR-6236 expression in mouse and human endothelial cells, whereas its inhibition improved viability, migration, tube formation, and reduced apoptosis. In vivo ischemic mouse skeletal muscle tissue showed higher miR-6236 expression compared with nonischemic muscles. Loss of miR-6236 improved impaired postischemic perfusion recovery and poor angiogenesis associated with streptozotocin-induced diabetes in mice. Six of the 8 miR-6236 predicted angiogenic target mRNAs showed expression consistent with regulation by miR-6236 in ischemic skeletal muscle.
Our results show for the first time that miR-6236 plays a key role in regulating postischemic perfusion recovery and angiogenesis.
外周动脉疾病影响全球超过2亿人，其特征是下肢血流受损。目前尚无有效的药物治疗方法。利用小鼠后肢缺血模型和微小RNA测序，我们鉴定出一种新型微小RNA，即miR-6236，与非缺血肢体相比，其在缺血小鼠肢体中的表达显著升高。miR-6236在一般情况下或缺血后血管生成中的作用尚不清楚。在此，我们使用外周动脉疾病的体内和体外模型描述其作用。
在原代小鼠和人内皮细胞中，我们研究了模拟缺血对miR-6236表达的影响，并评估了其在缺血期间细胞活力、凋亡、迁移和管形成中的作用。此外，我们构建了miR-6236基因敲除小鼠，并使用后肢缺血模型测试了其在缺血后灌注恢复中的作用。最后，通过生物信息学和基因表达分析，我们鉴定出潜在的血管生成性miR-6236靶点。体外模拟缺血增强了小鼠和人内皮细胞中miR-6236的表达，而对其抑制则提高了细胞活力、迁移、管形成并减少了凋亡。体内缺血小鼠骨骼肌组织与非缺血肌肉相比，miR-6236表达更高。miR-6236的缺失改善了链脲佐菌素诱导的糖尿病小鼠缺血后受损的灌注恢复和不良的血管生成。8个预测的miR-6血管生成靶点mRNA中有6个在缺血骨骼肌中的表达与miR-6236的调控一致。
我们的结果首次表明，miR-6236在调节缺血后灌注恢复和血管生成中起关键作用。
