Introduction

Valvular heart disease represents a significant burden to the healthcare system, with approximately 5 million cases diagnosed annually in the US. Among these cases, calcific aortic stenosis (CAS) stands out as the most prevalent form of valvular heart disease in the aging population. CAS is characterized by the progressive calcification of the aortic valve leaflets, leading to valve stiffening. While aortic valve replacement is the standard of care for CAS patients, the long-term durability of prosthetic devices is poor, calling for innovative strategies to halt or reverse disease progression. Here, we explor the potential use of novel extracellular vesicle (EV)-based nanocarriers for delivering molecular payloads to the affected valve tissue. This approach aims to reduce inflammation and potentially promote resorption of the calcified tissue.

Methods

Engineered EVs loaded with the reprogramming myeloid transcription factors, CEBPA and Spi1, known to mediate the transdifferentiation of committed endothelial cells into macrophages. We evaluated the ability of these engineered EVs to deliver DNA and transcripts encoding CEBPA and Spil into calcified aortic valve tissue obtained from patients undergoing valve replacement due to aortic stenosis. We also investigated whether these EVs could induce the transdifferentiation of endothelial cells into macrophage-like cells.

Results

Engineered EVs loaded with CEBPA + Spi1 were successfully derived from human dermal fibroblasts. Peak EV loading was found to be at 4 h after nanotransfection of donor cells. These CEBPA + Spi1 loaded EVs effectively transfected aortic valve cells, resulting in the successful induction of transdifferentiation, both in vitro with endothelial cells and ex vivo with valvular endothelial cells, leading to the development of anti-inflammatory macrophage-like cells.

Conclusions

Our findings highlight the potential of engineered EVs as a next generation nanocarrier to target aberrant calcifications on diseased heart valves. This development holds promise as a novel therapy for high-risk patients who may not be suitable candidates for valve replacement surgery.

中文翻译：

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基于细胞外囊泡的工程化治疗瓣膜性心脏病

介绍

瓣膜性心脏病给医疗保健系统带来了沉重负担，美国每年诊断出大约 500 万例心脏瓣膜病。在这些病例中，钙化性主动脉瓣狭窄 (CAS) 是老龄化人群中最常见的瓣膜性心脏病。CAS 的特点是主动脉瓣叶进行性钙化，导致瓣膜硬化。虽然主动脉瓣置换术是 CAS 患者的标准治疗方法，但假体装置的长期耐用性较差，需要创新策略来阻止或逆转疾病进展。在这里，我们探索了新型细胞外囊泡（EV）纳米载体的潜在用途，用于将分子有效负载传递到受影响的瓣膜组织。这种方法旨在减少炎症并可能促进钙化组织的吸收。

方法

工程化的 EV 装载有重编程骨髓转录因子CEBPA和Spi1，已知它们可以介导定型内皮细胞向巨噬细胞的转分化。我们评估了这些工程化 EV 将编码 CEBPA 和 Spil 的 DNA 和转录本递送到钙化主动脉瓣组织中的能力，该钙化主动脉瓣组织取自因主动脉瓣狭窄而接受瓣膜置换术的患者。我们还研究了这些 EV 是否可以诱导内皮细胞转分化为巨噬细胞样细胞。

结果

装载CEBPA + Spi1的工程化 EV成功地源自人类真皮成纤维细胞。发现 EV 负载峰值出现在供体细胞纳米转染后 4 小时。这些 负载CEBPA + Spi1的 EV 有效转染主动脉瓣细胞，从而成功诱导内皮细胞体外转分化和瓣膜内皮细胞离体转分化，从而导致抗炎巨噬细胞样细胞的发育。

结论

我们的研究结果强调了工程电动汽车作为下一代纳米载体的潜力，可以针对患病心脏瓣膜的异常钙化。这一进展有望成为一种新疗法，适用于那些可能不适合进行瓣膜置换手术的高危患者。