Epigenetic modulation of cognitive function: toward new treatment models

Abstract Background The current translational work is an outgrowth of a mechanistic framework in rodents with cognitive deficits and depressive‐like traits, wherein the levels of the pivotal mitochondrial metabolite acetyl‐L‐carnitine (LAC) are decreased and signal to the brain abnormal activity of histone acetyltransferase and expression of genes key for neuronal plasticity, such as mGlu2 (a key inhibitor of glutamate release). Yet, the role of this emerging signaling pathway of brain plasticity remains to be fully determined in subjects with cognitive impairments (CI). Method Here we performed ultraperformance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) to measure peripheral levels of LAC and the related mitochondrial metabolite free‐carnitine in a cohort of subjects with cognitive impairments (CI, n = 29) and age‐ and sex‐matched cognitively healthy controls (HC, n = 32). Next, we performed multiple regression analysis to investigate the relationship between mitochondrial metabolism of LAC and clinical characteristics. Result Decreased levels of the pivotal mitochondrial metabolite LAC in subjects with CI as compared to age‐ and sex‐matched HC subjects (p = 0.02), with potential sex differences in peripheral levels of free‐carnitine (p = 0.03). Incorporation of these new measures into a canonical biomarker model improved diagnostic accuracy Conclusion Our new translational findings suggest that a deficiency of LAC, and potential sex differences in free‐carnitine levels, might define clinical phenotypes of CI. Ongoing studies are ascertaining the role between LAC levels, and its main metabolite free‐carnitine, in relation to specific cognitive domains.