我们研究了Panxs（pannexins）在人类内皮祖细胞（EPC）衰老中的作用。我们使用源自人循环EPC的年轻细胞和复制诱导的老化内皮胞营养效价细胞（ECFCs）来检查短干扰RNA特异性靶向Panx1或介导的Panx1过表达的转染后的细胞活动和衰老相关的指标。我们使用下肢缺血小鼠作为体内血管生成模型。我们使用蛋白质和磷酸激酶阵列来确定潜在的机制。Panx1是人类ECFC中主要的Panx异构体，且在复制诱导的老化ECFCs以及老年小鼠和人类的循环EPCs中上调。Panx1下调可以增强年轻ECFC的细胞活动，但其上调则减弱细胞活动。此外，减少老化ECFC中的Panx1可以通过降低衰老相关指标（包括衰老相关β-半乳糖苷酶活性、p16INK4a（细胞周期依赖性激酶抑制剂2A）、p21（细胞周期依赖性激酶抑制剂1）、乙酰化p53（肿瘤蛋白P53）和磷酸化组蛋白H2A.X（组蛋白家族成员X））来使细胞活动恢复，同时在注射了老化ECFCs的小鼠缺血后肢中，Panx1敲定可以改善血液灌注比、挽救肢体后果以及毛细血管密度。Panx1敲定后，老化ECFCs培养基中的IGF-1（胰岛素样生长因子1）显著增加。抗-IGF-1抗体完全抑制了降低Panx1的老化ECFCs的增强活性和旁分泌效应。Panx1敲定的老化ECFCs中激活了FAK（黏附斑激酶）、ERK（细胞外信号调节激酶）和STAT3（转录因子和激活因子3）的生成，其中细胞内钙离子水平降低，而钙补充则抑制了这些激活。FAK（PF562271）、ERK（U0126）和STAT3（NSC74859）以及钙的补充分别抑制了Panx1敲定的ECFCs中IGF-1的增加。Panx1在有复制诱导的ECFCs和衰老中的人类ECFCs / EPCs中上调表达。通过减少Panx1来增强老化ECFCs的血管生成潜力，这是通过钙离子流减少引起的FAK-ERK轴激活增加IGF-1产生。我们的发现为评估EPC活性和重建老化EPCs进行治疗性血管生成提供了新的策略。

We examined the role of Panxs (pannexins) in human endothelial progenitor cell (EPC) senescence.Young and replication-induced senescent endothelial colony-forming cells (ECFCs) derived from human circulating EPCs were used to examine cellular activities and senescence-associated indicators after transfection of short interference RNA specific to Panx1 or lentivirus-mediated Panx1 overexpression. Hind limb ischemia mice were used as in vivo angiogenesis model. Protein and phospho-kinase arrays were used to determine underlying mechanisms.Panx1 was the predominant Panx isoform in human ECFCs and upregulated in both replication-induced senescent ECFCs and circulating EPCs from aged mice and humans. Cellular activities of the young ECFCs were enhanced by Panx1 downregulation but attenuated by its upregulation. In addition, reduction of Panx1 in the senescent ECFCs could rejuvenate cellular activities with reduced senescence-associated indicators, including senescence-associated β-galactosidase activity, p16INK4a (cyclin-dependent kinase inhibitor 2A), p21 (cyclin-dependent kinase inhibitor 1), acetyl-p53 (tumor protein P53), and phospho-histone H2A.X (histone family member X). In mouse ischemic hind limbs injected senescent ECFCs, blood perfusion ratio, salvaged limb outcome, and capillary density were all improved by Panx1 knockdown. IGF-1 (insulin-like growth factor 1) was significantly increased in the supernatant from senescent ECFCs after Panx1 knockdown. The enhanced activities and paracrine effects of Panx1 knockdown senescent ECFCs were completely inhibited by anti-IGF-1 antibodies. FAK (focal adhesion kinase), ERK (extracellular signal-regulated kinase), and STAT3 (signal transducer and activator of transcription 3) were activated in senescent ECFCs with Panx1 knockdown, in which the intracellular calcium level was reduced, and the activation was inhibited by supplemented calcium. The increased IGF-1 in Panx1-knockdown ECFCs was abrogated, respectively, by inhibitors of FAK (PF562271), ERK (U0126), and STAT3 (NSC74859) and supplemented calcium.Panx1 expression is upregulated in human ECFCs/EPCs with replication-induced senescence and during aging. Angiogenic potential of senescent ECFCs is improved by Panx1 reduction through increased IGF-1 production via activation of the FAK-ERK axis following calcium influx reduction. Our findings provide new strategies to evaluate EPC activities and rejuvenate senescent EPCs for therapeutic angiogenesis.