👤 Shinya Hayami

Aging and male sex are major risk factors for abdominal aortic aneurysm (AAA), a disease characterized by vascular cell phenotypic switching and aortic wall remodeling. Mitochondrial oxidative stress has been implicated in these changes. We previously demonstrated that NOX4 (NADPH oxidase 4) expression and activity increase with age in cardiovascular cells, promoting mitochondrial oxidative stress and vascular dysfunction. This study investigates whether NOX4-driven mitochondrial oxidative stress and DNA damage promote AAA development through vascular cell reprogramming. We used mitochondria-targeted NOX4-dependent mitochondrial DNA damage and activation of DNA-sensing pathways promote SMC phenotypic switching, inflammation, and aortic wall remodeling in AAA. Targeting NOX4 and enhancing mitochondrial function may offer therapeutic strategies for AAA prevention. 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

Gastric inhibitory polypeptide (GIP), which is released from the gastrointestinal tract, stimulates insulin secretion from pancreatic beta cells and plays a crucial role in the regulation of insulin secretion during the postprandial phase. We have isolated the human gene (GIPR) and cDNA encoding the GIP receptor by a combination of the conventional screening and polymerase chain reaction procedures. Human GIP receptor cDNA encodes a protein of 466 amino acids that is 81.5 and 81.2% identical to the previously cloned hamster and rat GIP receptor, respectively. Hydropathic analysis shows the presence of a signal peptide and seven potential transmembrane domains, a feature characteristic of the VIP/glucagon/secretin receptor family of G protein-coupled receptors. The human GIPR gene is about 13.8 kb long, consists of 14 exons, and carries 17 Alu repeats. Show less