VRC: Engineered extracellular vesicles for mild TBI-induced retinal injury

创伤性脑损伤（TBI）是运动损伤中视力丧失的主要原因， 美国，目前还没有治疗方法。我们的长期目标是开发安全、创新、 应对TBI视力丧失的策略。轻度TBI（mTBI），即使没有对眼睛的直接创伤，也会导致视网膜损伤。 通过小胶质细胞和Müller细胞驱动的炎症造成的损伤，以及视网膜神经节细胞损失造成的功能障碍 （RGC）。间充质干细胞（MSC）细胞外囊泡（EV）作为干细胞迅速出现 促进免疫调节，修复和再生的替代品。MSC EV注入玻璃体， 啮齿类动物表现出对RGCs、Müller细胞和小胶质细胞的嗜性，并引发特异性细胞反应， 其中来自EV的microRNA（miRNA）起着关键作用。 在这里，我们利用已发表的初步数据证明MSC EV可以减弱小胶质细胞 激活和RGC死亡。MSC EV的抗凋亡和抗炎作用进一步增强 通过使用亲本MSC的低氧预处理来“增压”EV，产生“H-EV”。MSC细胞系 被遗传改变以在EV中稳定过表达微小RNA（即，功能工程EV或FEE）， FEE模拟H-EV的抗凋亡和抗炎作用。该提案旨在中断 使用含有功能特异性miRNA的MSC-EV减轻轻度TBI的视网膜损伤，以减轻神经炎症 并伴随神经元功能障碍和细胞死亡。我们的中心假设是，有针对性的EV特异性 关键miRNAs的表达改善了小胶质细胞和Müller细胞驱动的炎症，以及RGC和 mTBI导致的视觉功能障碍。 Aim 1设计模拟H-EV功能的EV，以减弱小胶质细胞和Müller细胞活化， 体外视网膜神经元死亡。我们假设FEE增强了抗炎和抗凋亡作用， MSC-EV和模拟H-EV。H-EV中两种最高表达的miR将作为FEE进行研究， MSC EV、H-EV和对照在活化的视网膜小胶质细胞和暴露于谷氨酸的RGC和Müller细胞中。 确定FEE和H-EV的作用机制将为治疗精度提供新的途径 mTBI中视觉功能障碍的药物。 目的2确定FEE在临床相关小鼠中的体内抗炎和抗凋亡作用 mTBI模型我们将检验这一假设，即当给予FEE时， mTBI后。使用50 psi进行mTBI后的视网膜功能、细胞凋亡、谷氨酸水平和炎症介质 将定量地比较对颅骨的冲击，并且在用H-100处理的组中鉴定细胞特异性作用。 EV、FEE、MSC EV和对照。 拟议的研究预计将提供新的结果，其中MSC-EV经过改良，可起到保护作用， 治疗受TBI影响的视网膜细胞，并为其他神经退行性疾病提供新的潜在治疗方法。

Traumatic brain injury (TBI) is the leading cause of vision loss in sports injury, and automobile accidents in the United States, for which there currently is no treatment. Our long-term objective is to develop safe, innovative strategies to combat vision loss from TBI. Mild TBI (mTBI), even without direct trauma to the eye, results in retinal damage via microglia and Müller cell-driven inflammation, and dysfunction from loss of retinal ganglion cells (RGCs). Mesenchymal stem cell (MSC) extracellular vesicles (EVs) are rapidly emerging as a stem cell alternative that promote immunomodulation, repair, and regeneration. MSC EVs injected into the vitreous in rodents demonstrated tropism for RGCs, Müller cells, and microglia, and triggered specific cellular responses, with micro RNA (miRNA) from the EVs playing a key role. Here we capitalize upon our published and preliminary data demonstrating that MSC EVs attenuate microglial activation and RGC death in vitro. Anti-apoptosis and anti-inflammatory effects of MSC EVs were further boosted by “supercharging” the EVs using hypoxic preconditioning of the parent MSCs, yielding “H-EVs.” MSC cell lines were genetically altered to stably overexpress microRNAs in EVs (i.e., Functionally-Engineered EVs, or FEEs), and FEEs mimicked the anti-apoptosis and anti-inflammatory action of H-EVs. This proposal targets interrupting retinal damage from mild TBI with MSC-EVs containing function-specific miRNA to attenuate neuro-inflammation and accompanying neuronal dysfunction and cell death. Our central hypothesis is that targeted EV-specific expression of key miRNAs ameliorates microglia and Müller cell-driven inflammation, and loss of RGCs and subsequent visual dysfunction from mTBI. Aim 1 engineers EVs mimicking functionality of H-EVs to attenuate microglia and Müller cell activation and retinal neuron death in vitro. We hypothesize that FEEs enhance anti-inflammatory and anti-apoptosis effects of MSC-EVs and mimic H-EVs. Two of the highest expressed miRs in H-EVs will be studied as FEEs in comparison to MSC EVs, H-EVs, and controls in activated retinal microglia, and RGCs and Müller cells exposed to glutamate. Identifying mechanisms of action of FEEs and H-EVs will provide a novel pathway to therapeutic precision medicine for visual dysfunction in mTBI. Aim 2 determines in vivo anti-inflammatory and anti-apoptosis actions of FEEs in a clinically-relevant mouse model of mTBI. We will test the hypothesis that FEEs administered into the vitreous rescue the retina when given after mTBI. Retinal function, apoptosis, glutamate levels, and inflammatory mediators post mTBI using 50 psi blast to the cranium will be quantitatively compared, and cell-specific effects identified in groups treated with H- EVs, FEEs, MSC EVs, and controls. The proposed studies are expected to provide new results with MSC-EVs modified for protective action to treat the retinal cells affected by TBI, and provide novel potential therapy for other neurodegenerative disorders.