Biochemistry and Molecular Biology Department, Faculty of Pharmacy, Helwan University, P.O. Box 11795, Cairo, Egypt.
Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo-(GUC), Cairo, Egypt.
Inflammopharmacology. 2024 Jun;32(3):2061-2073. doi: 10.1007/s10787-024-01466-3. Epub 2024 Apr 2.
Autophagy is a crucial process involved in the degradation and recycling of cytoplasmic components which are transported to the lysosomal compartment by autophagosomes. Exosomes are an important means of communication and signaling in both normal and diseased states, and they have a significant role in the transmission and propagation of proteins, especially proteins implicated in neurodegenerative disorders. Autophagy may affect exosomal processing, but whether autophagy controls the release of aggregated β-amyloid and tau proteins in exosomes of Alzheimer disease (AD) is unclear. Therefore, our study aimed to investigate how modulating autophagy affects the exosomal release of these proteins in animal models of AD. Isolated exosomes from brain tissues of 48 male albino mice were divided into four groups (Negative control, LPS, rapamycin (RAPA), and chloroquine (CQ). LC3 I and LC3 II as well as Aβ and Tau proteins levels were determined. All mice undergone Neuro-behavioral tests (Morris Water maze test, Y-maze test, and Novel Object Recognition). Both LPS and CQ groups showed reduced expression levels of LC3 II and LC3 II/LC3 I ratio. In contrast, RAPA group showed a significant increase in both LC3-II expression and LC3-II/LC3-I ratio. The levels of both Aβ & Tau in exosomes of CQ & LPS groups were higher. While RAPA group showed a significant diminished levels of tau & Aβ proteins. In conclusion, our findings suggest that autophagy alterations in AD can influence the release of Aβ and tau proteins through exosomes, which may impact the spread of misfolded proteins in AD. These results highlight a potential innovative therapeutic approach for combating AD.
自噬是一种重要的过程,涉及细胞质成分的降解和回收,这些细胞质成分通过自噬体被运输到溶酶体隔室。外体是正常和疾病状态下重要的通讯和信号传递方式,它们在蛋白质,特别是与神经退行性疾病相关的蛋白质的传递和传播中发挥重要作用。自噬可能会影响外体的加工,但自噬是否控制阿尔茨海默病(AD)中外体中聚集的β-淀粉样蛋白和tau 蛋白的释放尚不清楚。因此,我们的研究旨在探讨调节自噬如何影响 AD 动物模型中外体释放这些蛋白质。从 48 只雄性白化小鼠的脑组织中分离出外体,将其分为四组(阴性对照、LPS、雷帕霉素(RAPA)和氯喹(CQ)。测定 LC3 I 和 LC3 II 以及 Aβ和 Tau 蛋白水平。所有小鼠均进行神经行为测试(Morris 水迷宫测试、Y 迷宫测试和新物体识别)。LPS 和 CQ 组均显示 LC3 II 和 LC3 II/LC3 I 比值表达水平降低。相反,RAPA 组的 LC3-II 表达和 LC3-II/LC3-I 比值均显著增加。CQ 和 LPS 组外体中 Aβ和 Tau 的水平均较高。而 RAPA 组的 Tau 和 Aβ 蛋白水平显著降低。总之,我们的研究结果表明,AD 中的自噬改变可能通过外体影响 Aβ和 tau 蛋白的释放,从而影响 AD 中错误折叠蛋白的传播。这些结果强调了一种有潜力的针对 AD 的创新治疗方法。