Abstract

Exosome is a promising next generation nano-based drug delivery vehicle. However, the unknown molecular mechanisms underlying its natural tissue tropism and the relatively low quantity of naturally enriched molecules of therapeutic value hamper exosome’s clinical application. The aim of the research was to create a targeted and highly efficacious exosome formulation for the treatment of Alzheimer’s disease (AD). Genetic engineering techniques combined with co-transfection of parental cells were employed to create an exosome formulation that displays RVG peptide on its surface targeting α7-nAChR and simultaneously enriches a neprilysin variant with increased specificity and efficacy in degrading β amyloid peptide (Aβ). The exosome formulation was preferentially internalised into cell lines in an α7-nAChR expression level-dependent manner. When incubated with Aβ-producing N2a cells, it significantly decreased intracellular and secreted Aβ40 levels, a potency that is superior to exosomes derived from adipose-derived stem cell. When systemically administered into mice, the exosome formulation was preferentially targeted to the hippocampus region of the brain and significantly decreased the expression of proinflammatory genes, IL1α, TNFα and NF-κB, and simultaneously increased the expression of anti-inflammatory gene, IL10. Our exosome formulation may be explored as an over-the-counter treatment for AD.

摘要

外泌体是一种很有前途的下一代纳米药物输送载体。然而，其天然组织趋向性的未知分子机制和相对较少的天然富集治疗价值分子阻碍了外泌体的临床应用。该研究的目的是创建一种靶向且高效的外泌体制剂，用于治疗阿尔茨海默病 (AD)。采用基因工程技术与亲代细胞的共转染相结合，创建了一种外泌体制剂，该制剂在其表面展示 RVG 肽，靶向 α7-nAChR，同时富集具有更高特异性和降解 β 淀粉样肽 (Aβ) 功效的中性溶酶变体。外泌体制剂以 α7-nAChR 表达水平依赖的方式优先内化到细胞系中。当与产生 Aβ 的 N2a 细胞一起孵育时，它显着降低了细胞内和分泌的 Aβ40 水平，这种效力优于源自脂肪干细胞的外泌体。当全身给药至小鼠时，外泌体制剂优先靶向大脑海马区，显着降低促炎基因IL1α、TNFα和NF-κB的表达，同时增加抗炎基因IL10的表达。我们的外泌体制剂可以作为 AD 的非处方药进行探索。外泌体制剂优先靶向大脑海马区，显着降低促炎基因IL1α、TNFα和NF-κB的表达，同时增加抗炎基因IL10的表达。我们的外泌体制剂可以作为 AD 的非处方药进行探索。外泌体制剂优先靶向大脑海马区，显着降低促炎基因IL1α、TNFα和NF-κB的表达，同时增加抗炎基因IL10的表达。我们的外泌体制剂可以作为 AD 的非处方药进行探索。