Bibliographic
This investigation aimed at testing the anti-degenerative activities of two p75NTR ligands LM11A-31 and LM11A-24 in the AβPPL/S mouse model of AD. The authors investigated the effects of the compounds on a range of AD-related phenotypic traits including ability to mitigate tau pathology, neuroinflammation, neuritic degeneration and behavioral deficits. Following oral administration, both ligands reached brain concentrations known to provide neuroprotection in vitro. Compound induction of p75NTR cleavage provided evidence for CNS target engagement. LM11A-31 and LM11A-24 reduced excessive phosphorylation of tau, and LM11A-31 also inhibited its aberrant folding. Both ligands decreased activation of microglia, while LM11A-31 attenuated reactive astrocytes. Along with decreased inflammatory responses, both ligands reduced cholinergic neurite degeneration. In addition to the amelioration of neuropathology in AD model mice, LM11A-31, but not LM11A-24, prevented impairments in water maze performance. Noth ligands prevented deficits in fear conditioning. These findings support a role for p75NTR ligands in preventing fundamental tau-related pathologic mechanisms in AD, and further validate the development of these small molecules as a new class of therapeutic compounds.