(175c) Immobilized Transmembrane Kinase Receptors As Screening Targets for Neurological Disorders

The treatment of neurodegenerative diseases remains as a great medical challenge, which affects millions of people. Currently, no truly effective treatments for neurodegenerative diseases are available. The failure of clinical translation of nearly all (> 400) tested compounds for Alzheimer’s Diseases (AD) triggered interested to develop alternative approaches of developing neuroprotective therapies to activate and restore neuronal functions. Many studies have shown brain-derived neurotrophic factor (BDNF) and its high affinity receptor, tropomyosin-receptor-kinase B (TrkB), are associated with neurological disorders, such as AD. TrkB is a transmembrane protein that activates a number of biological pathways upon activation. The development of techniques using transmembrane proteins as therapeutic targets is of great importance because over 60% of all modern pharmaceuticals target membrane proteins. Here, a novel drug screening platform based cell-membrane coated magnetic nanoclusters (CMMNs) will be disused, where the functional transmembrane receptors on the coating membrane serve as “smart baits” for direct identification of binding compounds from screening sources and the encapsulated magnetic nanoparticles enable quick isolation of identified compounds.

In this presentation, using TrkB as a model system, we evaluated the potential of this drug-screening platform in identifying binders from an artificial mixture and several plant extracts. The CMMNs were prepared using SH-SY5Y neuroblastoma cells overexpressing TrkB and 200 nm iron oxide nanoclusters were used as core materials. The formation of CMMNs was confirmed with transmission electron microscopy. The presence and activity of TrkB receptors on CMMN surfaces were studied using confocal microscopy with antibody labeling and ATP-ADP conversion experiment. The fishing experiments were performed by incubating CMMNs with an artificial mixture containing a known binder and several non-binders and by incubating CMMNs with Centella asiatica (Gotu kola) extracts at 37 °C for 20 minutes. The identified TrkB-bound compounds were analyzed using a Water Xevo G2xs QTof-MS with iclass UPLC system. Our fishing experiments suggested that the immobilized TrkB receptors on CMMN surfaces were able to selectively retain the known binder and could identify compounds from plant extracts. Total seven compounds were identified and all of which have been previous reported to play a role in the therapy of cognitive impartment.