Plasma metabolomics of presymptomatic PSEN1-H163Y mutation carriers: a pilot study

Background and Objective: PSEN1-H163Y carriers, at the presymptomatic stage, have reduced 18FDG-PET binding in the cerebrum of the brain (Scholl et al., Neurobiol Aging 32:1388–1399, 2011). This could imply dysfunctional energy metabolism in the brain. In this study, plasma of presymptomatic PSEN1 mutation carriers was analyzed to understand associated metabolic changes. Methods: We analyzed plasma from noncarriers (NC, n = 8) and presymptomatic PSEN1-H163Y mutation carriers (MC, n = 6) via untargeted metabolomics using gas and liquid chromatography coupled with mass spectrometry, which identified 1199 metabolites. All the metabolites were compared between MC and NC using univariate analysis, as well as correlated with the ratio of Ab1–42/Ab1–40, using Spearman’s correlation. Altered metabolites were subjected to Ingenuity Pathway Analysis (IPA). Results: Based on principal component analysis the plasma metabolite profiles were divided into dataset A and dataset B. In dataset A, when comparing between presymptomatic MC and NC, the levels of 79 different metabolites were altered. Out of 79, only 14 were annotated metabolites. In dataset B, 37 metabolites were significantly altered between presymptomatic MC and NC and nine metabolites were annotated. In both datasets, annotated metabolites represent amino acids, fatty acyls, bile acids, hexoses, purine nucleosides, carboxylic acids, and glycerophosphatidylcholine species. 1-docosapentaenoyl-GPC was positively correlated, uric acid and glucose were negatively correlated with the ratio of plasma Ab1–42/Ab1–40 (P < 0.05). Interpretation: This study finds dysregulated metabolite classes, which are changed before the disease symptom onset. Also, it provides an opportunity to compare with sporadic Alzheimer’s Disease. Observed findings in this study need to be validated in a larger and independent Familial Alzheimer’s Disease (FAD) cohort

Genetic and epigenetic studies of amyotrophic lateral sclerosis

The identification of genetic and epigenetic factors that are associated with an increased risk of developing amyotrophic lateral sclerosis (ALS), or that modify the age of onset or rate of progression, requires a multimodal research strategy, facilitated through international collaboration. The discovery of several ALS genes strongly linked to RNA biology, the proteasome pathway, and axonal transport suggest they have an important role in pathogenesis, but the immense complexity of these processes is also apparent. The increasing rate of genetic discoveries brings the hope of designing more targeted and efficacious therapies