Editorial: Biomarkers to disentangle the physiological from pathological brain aging, volume II

The worldwide increase in human life expectancy, together with the concomitant rapid aging of the population represent phenomena that have a substantial impact on our societies, representing major challenges for public health. In this context dementia is one of the most common diseases related to aging. However, the clinical manifestation of neurodegenerative disorders occurs, in most cases, several years after the biological manifestation, when the clinical picture is already compromised. This Research Topic, which includes four original research papers and one systematic review, shed light on genetic, biochemical and bio-imaging assessments, by suggesting novel non-invasive tools for the early diagnosis of Alzheimer's Disease (AD) and to aid the diagnosis among different forms of dementia.

The first paper performed an extensive bioinformatics analysis of AD-associated gene expression profiles highlighting five immune-related hub genes (CHGB, APLNR, FGF13, PAK1, and SERPINA3) as promising prognostic and diagnostic markers for AD (Zhao et al.). Furthermore, competing endogenous ribonucleic acid network (mRNA–miRNA–lncRNA) and single Gene set enrichment analysis, conducted for each hub gene, evidenced that these genes were enriched in “oxidative phosphorylation” and, in particular, that the AGAP3 gene is the most promising diagnostic target for AD development.