Search

The overlapping molecular pathophysiology of Alzheimer's Disease (AD), Amyotrophic Lateral Sclerosis (ALS), and Frontotemporal Dementia (FTD) was analyzed using relationships from a knowledge graph of 33+ million biomedical journal articles. The unsupervised learning rank aggregation algorithm from SemNet 2.0 compared the most important amino acid, peptide, and protein (AAPP) nodes connected to AD, ALS, or FTD. FTD shared 99.9% of its nodes with ALS and AD; AD shared 64.2% of its nodes with FTD and ALS; and ALS shared 68.3% of its nodes with AD and FTD. The results were validated and mapped to functional biological processes using supervised human supervision and an external large language model. The overall percentages of mapped intersecting biological processes were as follows: inflammation and immune response, 19%; synapse and neurotransmission, 19%; cell cycle, 15%; protein aggregation, 12%; membrane regulation, 11%; stress response and regulation, 9%; and gene regulation, 4%. Once normalized for node count, biological mappings for cell cycle regulation and stress response were more prominent in the intersection of AD and FTD. Protein aggregation, gene regulation, and energetics were more prominent in the intersection of ALS and FTD. Synapse and neurotransmission, membrane regulation, and inflammation and immune response were greater at the intersection of AD and ALS. Given the extensive molecular pathophysiology overlap, small differences in regulation, genetic, or environmental factors likely shape the underlying expressed disease phenotype. The results help prioritize testable hypotheses for future clinical or experimental research. [ABSTRACT FROM AUTHOR]

Unfortunately, survivors of traumatic stress exposure (TSE) frequently develop adverse posttraumatic neuropsychiatric sequelae (APNS) such as chronic pain and stress/depressive symptoms. Increasing evidence indicates that there is a 'window of opportunity' following TSE in which therapeutic interventions are most effective against APNS, yet mechanisms accounting for this observation are poorly understood. Here, we aimed to better understand such mechanisms by generating snapshots of the transcriptional landscape in the early aftermath of TSE across tissues and time. Adult rats were exposed to a TSE model, single prolonged stress (SPS). Then, eight tissues (hypothalamus, left and right hippocampus, amygdala, dorsal root ganglia, spinal cord, heart, and muscle) were isolated from these animals at 2, 24, and 72 hours after SPS and in unexposed controls (n=6 per group). mRNA expression from deep sequencing was used to identify differentially expressed genes (DEGs) and biological pathways enriched over time. In all tissues except the amygdala, the highest number of DEGs was observed 2-hours post-SPS, but DEGs were detected at all timepoints and in all tissues. Some transcripts were differentially expressed in a consistent manner across multiple tissues at a time point (e.g. Fkbp5, 2 hours post-SPS), while others had tissue- or region-specific expression patterns. Stress system pathways were most represented at 2-hours post-SPS, then stress/circadian/inflammatory pathways at 24-hours, and inflammatory pathways at 72-hours. Together these findings provide insights into post-TSE transcriptional landscape dynamics and suggest specific intervention windows of opportunity. Future validation is needed across sex, age, stressor, and cell type.