👤 Sho Maejima

Aging-related cognitive decline is a major concern in aging societies. Theobromine (TB), a cacao-derived methylxanthine, exerts neuroprotective effects through anti-inflammatory, antioxidant, and neurotrophic mechanisms; however, its efficacy in aging models remains unclear. This study investigated the mechanisms underlying neuroprotective effects of chronic TB administration in senescence-accelerated mouse prone 8 (SAMP8), a model of age-related memory impairment. SAMP8 and SAMR1 mice were fed either a control diet or a diet supplemented with 0.05% TB for 50 d. Cognitive performance was evaluated by the novel object recognition (NOR) test. Neurotrophic factors (BDNF and NT-3), synaptic proteins (PSD95 and synaptophysin), and plasticity-related signaling molecules (phosphorylated CREB and TrkB) were analyzed in the prefrontal cortex and hippocampus. Inflammatory cytokines, lipid peroxides, and antioxidant enzymes were quantified. Molecular docking was used to assess TB's interaction with phosphodiesterase (PDE) enzymes. TB improved short-term memory in SAMP8, increasing discrimination index in the NOR test. This was accompanied by increased BDNF, NT-3, PSD95, and synaptophysin levels and enhanced CREB and TrkB phosphorylation. Furthermore, TB lowered the levels of pro-inflammatory cytokines (IL-1β, TNF-α) and phosphorylated NF-κB, reduced lipid peroxidation, and increased the levels of antioxidant markers (HO-1, GSH). These effects were minimal in SAMR1. No adverse effects on body weight or blood parameters were observed. Molecular docking indicated that TB binds to PDE enzymes with weaker inhibitory activity than selective inhibitors. TB enhances short-term memory and synaptic function in aged mice via neurotrophic, antioxidant, and anti-inflammatory mechanisms, supporting its potential as a safe dietary intervention for age-related cognitive decline. Show less

Recent studies applying high-throughput sequencing technologies have identified several recurrently mutated genes and pathways in multiple cancer genomes. However, transcriptional consequences from these genomic alterations in cancer genome remain unclear. In this study, we performed integrated and comparative analyses of whole genomes and transcriptomes of 22 hepatitis B virus (HBV)-related hepatocellular carcinomas (HCCs) and their matched controls. Comparison of whole genome sequence (WGS) and RNA-Seq revealed much evidence that various types of genomic mutations triggered diverse transcriptional changes. Not only splice-site mutations, but also silent mutations in coding regions, deep intronic mutations and structural changes caused splicing aberrations. HBV integrations generated diverse patterns of virus-human fusion transcripts depending on affected gene, such as TERT, CDK15, FN1 and MLL4. Structural variations could drive over-expression of genes such as WNT ligands, with/without creating gene fusions. Furthermore, by taking account of genomic mutations causing transcriptional aberrations, we could improve the sensitivity of deleterious mutation detection in known cancer driver genes (TP53, AXIN1, ARID2, RPS6KA3), and identified recurrent disruptions in putative cancer driver genes such as HNF4A, CPS1, TSC1 and THRAP3 in HCCs. These findings indicate genomic alterations in cancer genome have diverse transcriptomic effects, and integrated analysis of WGS and RNA-Seq can facilitate the interpretation of a large number of genomic alterations detected in cancer genome. Show less