HIGH THROUGHPUT BIOASSAY FOR IDENTIFYING SELECTIVE TRKA RECEPTOR AGONISTS, AND GAMBOGIC AMIDE, A SELECTIVE TRKA AGONIST WITH NEUROPROTECTIVE ACTIVITY

摘要

A high-throughput screening assay for identifying small molecule agonists for the TrkA receptor is described. One such agonist, gambogic amide, selectively binds to TrkA but not TrkB or C, robustly induces its tyrosine phosphorylation and downstream signaling activation including Akt and MAP kinases. Further, it strongly prevents glutamate-induced neuronal cell death and provokes prominent neurite outgrowth in PC 12 cells. Gambogic amide specifically interacts with the cytoplasmic juxtamembrane domain of TrkA receptor and triggers its dimerization. Administration of this molecule in mice substantially diminishes Kainic acid-triggered neuronal cell death and decreases infarct volume in transient middle cerebral artery occlusion (MCAO) model of stroke. Thus, gambogic amide and other selective TrkA agonists can provide effective treatments for debilitating neurodegenerative diseases and provide neuroprotection from patients suffering from stroke or other ischemic events.