Cardiac endothelial cells (ECs) are important targets for cardiovascular gene therapy. However, the approach of stably transducing ECs in vivo using different vectors, including adeno-associated virus (AAV), remains unexamined. Regarding this unmet need, two AAV libraries from DNA shuffling and random peptide display were simultaneously screened in a transgenic mouse model. Cardiac ECs were isolated by cell sorting for salvage of EC-targeting AAV. Two AAV variants, i.e., EC71 and EC73, enriched in cardiac EC, were further characterized for their tissue tropism. Both of them demonstrated remarkably enhanced transduction of cardiac ECs and reduced infection of liver ECs in comparison to natural AAVs after intravenous injection. Significantly, persistent transgene expression was maintained in mouse cardiac ECs in vivo for at least 4 months. The EC71 vector was selected for delivery of the endothelial nitric oxide synthase (eNOS) gene into cardiac ECs in a mouse model of myocardial infarction. Enhanced eNOS activity was observed in the mouse heart and lung, which was correlated with partially improved cardiac function. Taken together, two AAV capsids were evolved with more efficient transduction in cardiovascular endothelium in vivo, but their endothelial tropism might need to be further optimized for practical application to cardiac gene therapy.

心脏内皮细胞（ECs）是心血管基因治疗的重要靶点。然而，使用包括腺相关病毒 (AAV) 在内的不同载体在体内稳定转导 ECs 的方法仍未得到研究。针对这一未满足的需求，在转基因小鼠模型中同时筛选了来自 DNA 改组和随机肽展示的两个 AAV 文库。通过细胞分选分离心脏 EC，以挽救 EC 靶向 AAV。两种 AAV 变体，即 EC71 和 EC73，富含心脏 EC，进一步表征了它们的组织趋向性。与静脉注射后的天然 AAV 相比，它们都表现出显着增强的心脏 ECs 转导和减少肝 ECs 感染。值得注意的是，小鼠心脏 ECs 中保持了持续的转基因表达体内至少4个月。选择 EC71 载体将内皮一氧化氮合酶 (eNOS) 基因递送到心肌梗塞小鼠模型中的心脏 EC。在小鼠心脏和肺中观察到 eNOS 活性增强，这与部分改善的心脏功能相关。总之，两个 AAV 衣壳在体内心血管内皮中具有更有效的转导，但它们的内皮趋向性可能需要进一步优化，以实际应用于心脏基因治疗。