👤 Reiko Kishi

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

Sodium perfluorononenoxybenzene sulfonate (OBS), a substitute for perfluorooctane sulfonate (PFOS), has been frequently detected in the environment and human blood. Although OBS exposure has been identified as a novel risk factor for atherosclerosis associated with endothelial dysfunction, the underlying molecular mechanisms remain unclear. In this study, in vitro experiments using human umbilical vein endothelial cells (HUVECs) demonstrated that OBS exposure induced oxidative stress, activated the PERK-eIF2α-ATF4 axis of endoplasmic reticulum stress (ERS) and triggered NF-κB signaling. Pharmacological inhibition with N-acetylcysteine (NAC, an antioxidant), 4-phenylbutyric acid (4-PBA, an ERS inhibitor), and BAY 11-7082 (an inhibitor for NF-κB signaling pathway) revealed a sequential pathogenic cascade, in which oxidative stress acts upstream to initiate ERS and compromise endothelial barrier function, leading to NF-κB activation, which drives inflammatory responses, monocyte adhesion, and impaired endothelial migration. Consistent with these findings, in vivo experiments in ApoE Show less

Hypospadias is a common congenital anomaly caused by incomplete fusion of urethral folds. Development of the urethra and external genital system in the male fetus is an androgen-dependent process. In this regard, enzymes 17 β-hydroxysteroid dehydrogenase type 3 (17 β HSD3, encoded by HSD17B3) and steroid 5 α-reductase type 2 (encoded by SRD5A2) play crucial roles. To investigate the possible associations between common polymorphisms in HSD17B3 as well as well-known V89L polymorphism in SRD5A2 and risk of hypospadias. A case-control study was performed between 1999 and 2005. There were 89 Japanese boys with hypospadias and 291 newborn controls. We genotyped HSD17B3-1999T>C, +10A>G, +20A>G, +139G>A (V31I), +913G>A (G289S), and SRD5A2+336G>C (V89L) polymorphisms by allelic discrimination assay. We measured mRNA expression of the wildtype G289 allele and the mutant S289 allele of the HSD17B3 gene in the transfected human fetal kidney HEK293 cells. Assessment of hypospadias including its severity and HSD17B3 and SRD5A2 genes using DNA blood samples: allele and genotype distribution of single nucleotide polymorphisms in these two genes in cases and controls. In our study, the risk of hypospadias was significantly higher in subjects carrying homozygous HSD17B3+913A (289S) alleles (odds ratio [OR]: 3.06; 95% confidence interval [CI]: 1.38-6.76). The risk of severe hypospadias was much higher in these subjects (OR: 3.93; 95% CI: 1.34-11.49). The mRNA expression levels of HSD17B3 G289 were higher than those of HSD17B3 S289 mutant (P < 0.001). In addition, the risk of severe hypospadias increased in boys carrying the SRD5A2+336C (89L) allele (OR: 3.19; 95% CI: 1.09-9.36). These results suggest that the HSD17B3 G289S polymorphism may be a potential risk modifier for hypospadias. Our findings provide evidence that a certain genotype related to androgen production may potentiate risk of hypospadias. Show less