Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, 13620, Korea.
Bundang CHA Biobank, CHA University College of Medicine, CHA University Bundang Medical Center, Seongnam, 13496, Korea.
Tissue Eng Regen Med. 2023 Oct;20(6):951-964. doi: 10.1007/s13770-023-00555-8. Epub 2023 Jul 13.
Retinal degenerative disease (RDD), one of the most common causes of blindness, is predominantly caused by the gradual death of retinal pigment epithelial cells (RPEs) and photoreceptors due to various causes. Cell-based therapies, such as stem cell implantation, have been developed for the treatment of RDD, but potential risks, including teratogenicity and immune reactions, have hampered their clinical application. Stem cell-derived extracellular vesicles (EVs) have recently emerged as a cell-free alternative therapeutic strategy; however, additional invasiveness and low yield of the stem cell extraction process is problematic.
To overcome these limitations, we developed therapeutic EVs for the treatment of RDD which were extracted from tonsil-derived mesenchymal stem cells obtained from human tonsil tissue discarded as medical waste following tonsillectomy (T-MSC EVs). To verify the biocompatibility and cytoprotective effect of T-MSC EVs, we measured cell viability by co-culture with human RPE without or with toxic all-trans-retinal. To elucidate the cytoprotective mechanism of T-MSC EVs, we performed transcriptome sequencing using RNA extracted from RPEs. The in vivo protective effect of T-MSC EVs was evaluated using Pde6b gene knockout rats as an animal model of retinitis pigmentosa.
T-MSC EVs showed high biocompatibility and the human pigment epithelial cells were significantly protected in the presence of T-MSC EVs from the toxic effect of all-trans-retinal. In addition, T-MSC EVs showed a dose-dependent cell death-delaying effect in real-time quantification of cell death. Transcriptome sequencing analysis revealed that the efficient ability of T-MSC EVs to regulate intracellular oxidative stress may be one of the reasons explaining their excellent cytoprotective effect. Additionally, intravitreally injected T-MSC EVs had an inhibitory effect on the destruction of the outer nuclear layer in the Pde6b gene knockout rat.
Together, the results of this study indicate the preventive and therapeutic effects of T-MSC EVs during the initiation and development of retinal degeneration, which may be a beneficial alternative for the treatment of RDD.
视网膜退行性疾病（RDD）是导致失明的最常见原因之一，主要是由于各种原因导致视网膜色素上皮细胞（RPE）和光感受器逐渐死亡。基于细胞的疗法，如干细胞移植，已被开发用于治疗 RDD，但包括致畸性和免疫反应在内的潜在风险阻碍了它们的临床应用。最近，干细胞衍生的细胞外囊泡（EVs）作为一种无细胞的替代治疗策略出现，但干细胞提取过程的额外侵袭性和低产量是有问题的。
为了克服这些限制，我们从扁桃体组织中提取出治疗 RDD 的治疗性 EVs，这些 EVs 来源于扁桃体切除术后作为医疗废物丢弃的人扁桃体组织中的间充质干细胞（T-MSC EVs）。为了验证 T-MSC EVs 的生物相容性和细胞保护作用，我们通过与人 RPE 共培养来测量细胞活力，共培养物中存在或不存在有毒的全反式视黄醛。为了阐明 T-MSC EVs 的细胞保护机制，我们使用从 RPE 中提取的 RNA 进行了转录组测序。使用 Pde6b 基因敲除大鼠作为色素性视网膜炎的动物模型，评估了 T-MSC EVs 的体内保护作用。
T-MSC EVs 表现出高生物相容性，并且在存在 T-MSC EVs 的情况下，人色素上皮细胞明显免受全反式视黄醛的毒性影响。此外，T-MSC EVs 在实时定量细胞死亡中表现出剂量依赖性的细胞死亡延迟作用。转录组测序分析表明，T-MSC EVs 有效调节细胞内氧化应激的能力可能是其出色细胞保护作用的原因之一。此外，T-MSC EVs 玻璃体腔内注射对 Pde6b 基因敲除大鼠外核层的破坏具有抑制作用。
综上所述，这项研究的结果表明 T-MSC EVs 在视网膜变性的发生和发展过程中具有预防和治疗作用，这可能是治疗 RDD 的有益替代方法。
