De novo peptide sequencing is a promising approach for novel peptide discovery. We use a novel concept of complementary spectra to enhance ion information and propose a de novo sequencing model PandaNovo based on Transformer architecture. PandaNovo outperforms other state-of-the-art models and enhances the taxonomic resolution of gut metaproteome, taking a significant step forward in de novo sequencing.

Background: Long noncoding RNA EPB41L4A-AS1 plays a very important role in metabolism. Aging and neurodegenerative diseases are typical metabolic-related processes. As a metabolism-related lncRNA, EPB41L4A-AS may be involved in the development of brain aging and neurodegenerative diseases. In this study, we aim to reveal the mechanism of EPB41L4A-AS in aging and neurodegenerative diseases.Methods: Age-related differential expression analysis was applied on the gene expression profile of the hippocampus in the Genotype-Tissue Expression database to obtain age-related differentially expressed genes and the weighted correlation network analysis algorithm was used to construct a gene co-expression network for age-related differentially expressed genes to obtain different gene clustering modules. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, protein-protein interaction network, and correlation analysis were used to reveal the mechanism of EPB41L4A-AS1. The mechanism was verified using Gene Expression Omnibus profile GSE5281 and biology experiments (construction of cell lines, Real-time quantitative PCR, Western blot, measurement of ATP and NAD+ levels, nicotinamide riboside treatment, Chromatin Immunoprecipitation) in neurons and glial-derived cells.Results: EPB41L4A-AS1 is down-regulated in aging and Alzheimer’s disease. EPB41L4A-AS1 related genes are genes of the electron transport chain and NAD+ synthesis pathway. Furthermore, these genes are highly related to neurodegenerative diseases and EPB41L4A-AS1 has a positive correlation with them. In addition, biology experiments proved that the down-regulation of EPB41L4A-AS1 can reduce the expression of these genes via modification of the acetylation of lysine 27 on histone 3, resulting in the down-regulation of NAD+ and ATP levels, while the overexpression of EPB41L4A-AS1 and nicotinamide riboside treatment can restore the levels of NAD+ and ATP.Conclusions: Down-regulation of EPB41L4A-AS1 not only disturbs NAD+ biosynthesis but also affects ATP production. As a result, the high demand of brain for NAD+ and ATP can not be met, which promotes the development of brain aging and neurodegenerative diseases. However, overexpression of EPB41L4A-AS1 and nicotinamide riboside, a substrate of NAD+ synthesis, can reduce EPB41L4A-AS1 down-regulation mediated decrease of NAD+ and ATP synthesis. Our results provide a new perspective on brain aging and neurodegenerative diseases.