Genetic and Pharmacological Inhibition of Metabotropic Glutamate Receptor Signalling Extends Lifespan in <i>Drosophila</i>

Invertebrate models have been instrumental in advancing our understanding of the molecular mechanisms of ageing. The isolation of single gene mutations that both extend lifespan and improve age-related health have identified potential targets for therapeutic intervention to alleviate age-related morbidity. Here, we find that genetic loss of function of the G protein-coupled metabotropic glutamate receptor (DmGluRA) in Drosophila extends the lifespan of female flies. This longevity phenotype was accompanied by lower basal levels of oxidative stress and improved stress tolerance, and differences in early-life behavioural markers. Gene expression changes in DmGluRA mutants identified reduced ribosome biogenesis, a hallmark of longevity, as a key process altered in these animals. We further show that the pro-longevity effects of reduced DmGluRA signalling are dependent on the fly homologue of Fragile X Mental Retardation Protein (FMRP), an important regulator of ribosomal protein translation. Importantly, we can recapitulate lifespan extension using a specific pharmacological inhibitor of mGluR activity. Hence, our study identifies metabotropic glutamate receptors as potential targets for age-related therapeutics.