Metabolic aspects behind ageing and neurodegeneration reveal new ways forward for therapy in motorneurone(ALS) and Parkinson diseases

Human beings evolved to run over a relatively short evolutionary time scale, ~1 million years, 2-3 million years ago, markedly increasing metabolic rate and VO2max, compared with other primates, while increasing brain size,and lifespan. Ageing leads to precise declines in performance and metabolism(VO2max): are there links with ageing-related diseases? Glucocerebrosidase(GCase;GBA1 subtype) mutations are the most common cause of Parkinson Disease,where there is lysosomal disruption and a reciprocal feedback between glucosylceramide and a-synuclein. We have shown that GBA2 is elevated and, using metabolomics, that ceramide and glucosylceramide levels are critically modified presymptomatically and at early stage in the spinal cord of superoxide dismutase1 mutant mice(SOD1G86R, ALS model),and lipid metabolism is massively changed at end stage disease. Modification of glucosylceramide synthase(GCS), and GCase activites shows that inhibiting GCS is deleterious and inhibiting GCase is beneficial to both neuromuscular junction function in sciatic nerve crush, and also grip strength and survival in the SOD1G86R model. Ambroxol(3 mmol·L-1 in drinking water), a glucocerebrosidase chaperone, accelerated recovery of NMJ function in sciatic nerve crush, and ameliorated grip strength and survival in the SOD1G86R model. Ambroxol is phase 2 ready in ALS and starting phase 3 in Parkinson disease.