Publications by authors named "Yuri Tani"

Ferroptosis is a form of regulated cell death that is induced by inhibiting glutathione peroxidase 4 (GPX4), which eliminates lipid peroxidation. Ferroptosis induction is influenced by the cell environment. However, the cellular states altering ferroptosis susceptibility remain largely unknown.

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The unfolded protein response (UPR) is an adaptive stress response pathway that is essential for cancer cell survival under endoplasmic reticulum stress such as during glucose starvation. In this study, we identified spautin-1, an autophagy inhibitor that suppresses ubiquitin-specific peptidase 10 (USP10) and USP13, as a novel UPR inhibitor under glucose starvation conditions. Spautin-1 prevented the induction of UPR-associated proteins, including glucose-regulated protein 78, activating transcription factor 4, and a splicing variant of x-box-binding protein-1, and showed preferential cytotoxicity in glucose-starved cancer cells.

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Previous studies have revealed the importance of inter-tissue communications for lifespan regulation. However, the inter-tissue network responsible for lifespan regulation is not well understood, even in a simple organism . To understand the mechanisms underlying systemic lifespan regulation, we focused on lifespan regulation by the insulin/insulin-like growth factor-1 signaling (IIS) pathway; IIS reduction activates the DAF-16/FOXO transcription factor, which results in lifespan extension.

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BRAF V600 mutation influences cellular signaling pathways for melanoma development. However, the role of oncogenic BRAF in adaptive stress response pathways is not fully understood. Here, we show that oncogenic BRAF plays an essential role in the induction of ATF4 following the activation of general control non-derepressible 2 (GCN2) kinase during nutrient stress and BRAF-targeted, therapeutic stress.

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As a branch of the unfolded protein response, protein kinase R-like endoplasmic reticulum kinase (PERK) represses global translation in response to endoplasmic reticulum (ER) stress. This pathophysiological condition is associated with the tumor microenvironment in cancer. Previous findings in our lab have suggested that PERK selectively represses translation of some mRNAs, but this possibility awaits additional investigation.

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It has been difficult to elucidate the structure of gene regulatory networks under anticancer drug treatment. Here, we developed an algorithm to highlight the hub genes that play a major role in creating the upstream and downstream relationships within a given set of differentially expressed genes. The directionality of the relationships between genes was defined using information from comprehensive collections of transcriptome profiles after gene knockdown and overexpression.

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Mitochondria can be involved in regulating cellular stress response to hypoxia and tumor growth, but little is known about that mechanistic relationship. Here, we show that mitochondrial deficiency severely retards tumor xenograft growth with impairing hypoxic induction of HIF-1 transcriptional activity. Using mtDNA-deficient ρ0 cells, we found that HIF-1 pathway activation was comparable in slow-growing ρ0 xenografts and rapid-growing parental xenografts.

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Prostate transmembrane protein, androgen induced 1 (PMEPA1) is highly expressed in various solid tumors and is known to play important roles in the transforming growth factor-β (TGF-β) signaling pathway. Here, we demonstrate a novel relationship between PMEPA1 and hypoxia, a common microenvironmental stress condition in solid tumors. We showed that induction of PMEPA1 expression occurred during hypoxia in a manner dependent on both TGF-β signaling and hypoxia-inducible factor-1 (HIF-1) pathways.

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Jungle Crows (Corvus macrorhynchos) prefer human habitats because of their versatility in feeding accompanied with human food consumption. Therefore, it is important from a public health viewpoint to characterize their intestinal microbiota. However, no studies have been involved in molecular characterization of the microbiota based on huge and reliable number of data acquisition.

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Differences in the ultraviolet (UV) cutoff of ocular media between birds and mammals have been revealed by spectrophotometric measurements of the transmission of light wavelengths by the cornea, lens and vitreous body in chickens, crows, quails, rats, rabbits and pigs. The light transmission values of the cornea were shown to be above 50% for wavelengths of 330-800 nm in birds, 300-800 nm in rat and 310-800 nm in mammals except for rat. For the lens, the light transmission values were shown to be above 50% for wavelengths of 320-800 nm in birds and rat and 390-800 nm in mammals except for rat.

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Water-soluble proteins in avian corneas were profiled by two-dimensional electrophoresis and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Comparative protein profiling of avian and mammalian corneas revealed five major protein spots specifically detected in avian species. These proteins were identified as apolipoproteins A1 and D by tandem mass spectrometry sequencing.

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In this study, the microstructure of the cornea was compared among chickens (Gallus gallus), jungle crows (Corvus macrorhynchos), rats (Rattus norvegicus) and rabbits (Oryctolagus cuniculus). The density of keratocytes in the mammals was over 3 times that in the birds. The size of the keratocytes in the birds and rat were significantly lower than those in the rabbit.

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Genetically modified bacterial biosensors can detect specific environmental compounds. Here, we attempted to establish a fluorescent microplate method to detect arsenic using recombinant Escherichia coli cells transformed with plasmids harboring three tandem copies of the ars promoter/operator-the gene for green fluorescent protein (gfp). In the biosensors, one copy of arsR, whose transcription is autoregulated by the ars promoter/operator and ArsR in the genome of E.

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