mGluR7 allosteric modulator AMN082 corrects protein synthesis and pathological phenotypes in FXS

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• Fragile X syndrome (FXS) is a leading genetic cause of autism and intellectual disability.
• The primary defect in FXS is the loss of fragile X messenger ribonucleoprotein (FMRP), causing aberrant protein synthesis and cellular/behavioral issues.
• Currently, no effective treatments exist for FXS.

Purpose of the Study:

• To investigate the therapeutic potential of activating metabotropic glutamate receptor 7 (mGluR7) in the context of FXS.
• To explore the mechanisms underlying the effects of mGluR7 activation on protein synthesis and neuronal function.

Main Methods:

• Utilized AMN082, a positive allosteric modulator, to activate mGluR7.
• Examined the impact of AMN082 on protein synthesis via ERK1/2 and eIF4E signaling pathways.
• Assessed neuronal excitability, audiogenic seizure susceptibility, repetitive behaviors, learning, and memory in Fmr1 KO mice (FXS model).

Main Results:

• AMN082-induced mGluR7 activation repressed protein synthesis independently of FMRP.
• Treatment with AMN082 reduced neuronal excitability and ameliorated audiogenic seizure susceptibility in Fmr1 KO mice.
• AMN082 administration decreased repetitive behaviors and improved learning and memory in the FXS mouse model.

Conclusions:

• This study reveals novel functions for mGluR7 and its modulator AMN082.
• Activation of mGluR7 presents a promising therapeutic avenue for Fragile X syndrome.
• The findings suggest targeting mGluR7 could address core deficits in FXS.