Leinenga Gerhard, Bodea Liviu-Gabriel, Koh Wee Kiat, Nisbet Rebecca M, Götz Jürgen
Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland.
Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland;
J Vis Exp. 2020 Jul 18(161). doi: 10.3791/61372.
Only a small fraction of therapeutic antibodies targeting brain diseases are taken up by the brain. Focused ultrasound offers a possibility to increase uptake of antibodies and engagement through transient opening of the blood-brain barrier (BBB). In our laboratory, we are developing therapeutic approaches for neurodegenerative diseases in which an antibody in various formats is delivered across the BBB using microbubbles, concomitant with focused ultrasound application through the skull targeting multiple spots, an approach we refer to as scanning ultrasound (SUS). The mechanical effects of microbubbles and ultrasound on blood vessels increases paracellular transport across the BBB by transiently separating tight junctions and enhances vesicle- mediated transcytosis, allowing antibodies and therapeutic agents to effectively cross. Moreover, ultrasound also facilitates the uptake of antibodies from the interstitial brain into brain cells such as neurons where the antibody distributes throughout the cell body and even into neuritic processes. In our studies, fluorescently labeled antibodies are prepared, mixed with in-house prepared lipid-based microbubbles and injected into mice immediately before SUS is applied to the brain. The increased antibody concentration in the brain is then quantified. To account for alterations in normal brain homeostasis, microglial phagocytosis can be used as a cellular marker. The generated data suggest that ultrasound delivery of antibodies is an attractive approach to treat neurodegenerative diseases.
靶向脑部疾病的治疗性抗体仅有一小部分会被大脑摄取。聚焦超声提供了一种通过短暂打开血脑屏障（BBB）来增加抗体摄取和作用的可能性。在我们实验室，我们正在开发针对神经退行性疾病的治疗方法，即使用微泡将各种形式的抗体输送穿过血脑屏障，同时通过颅骨对多个靶点进行聚焦超声照射，我们将这种方法称为扫描超声（SUS）。微泡和超声对血管的机械作用通过短暂分离紧密连接增加了跨血脑屏障的细胞旁转运，并增强了囊泡介导的转胞吞作用，使抗体和治疗药物能够有效穿过。此外，超声还促进抗体从脑间质摄取到脑细胞（如神经元）中，抗体在神经元的整个细胞体甚至神经突起中分布。在我们的研究中，制备荧光标记的抗体，与自制的脂质微泡混合，并在对大脑应用扫描超声之前立即注射到小鼠体内。然后对大脑中增加的抗体浓度进行定量。为了考虑正常脑内稳态的改变，小胶质细胞吞噬作用可作为一种细胞标志物。所产生的数据表明，超声递送抗体是治疗神经退行性疾病的一种有吸引力的方法。
