Biology subjects

Kawajiri, K.

Publications and source records attributed to Kawajiri, K..

4 recordsLinked to original sources

bioRxiv2025

Altered MicroRNA Signatures in Circulating Extracellular Vesicles Reflect Aortic Dilation in Takayasu Arteritis

BackgroundTakayasu arteritis (TAK) is a large-vessel vasculitis characterized by progressive inflammation that can lead to stenosis or aneurysmal dilation. Reliable circulating biomarkers for vascular remodeling are lacking, and extracellular vesicles (EVs), which transport molecular cargo that reflects their cellular origin, have emerged as potential biomarkers and modulators of vascular inflammation. However, their role in TAK remains unclear. This study aimed to investigate the relationship between EV-derived microRNA (miRNA) signatures and clinically relevant vascular phenotypes, with a primary focus on aortic dilation. MethodsCirculating small EVs (sEVs) were isolated from the serum of patients with TAK and healthy controls, characterized by high-sensitivity flow cytometry, were profiled for miRNA content, and analyzed using bioinformatic pathway enrichment. In vitro assays were employed in assessing their impact on endothelial activation, while the diagnostic performance of miRNAs was compared to conventional biomarkers and clinical parameters. ResultssEVs from patients with TAK upregulated the endothelial expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, thereby enhancing monocyte adhesion in vitro, consistent with a pro-inflammatory phenotype. Differentially expressed miRNAs were enriched in PI3K-Akt signaling, with phosphatase and tensin homolog identified as a key predicted target. Among patients, miR-223-3p was selectively downregulated in those with aortic dilation, regardless of disease activity or treatment status. Receiver operating characteristic analysis showed that miR-223-3p identified aortic dilation with an area under the curve of 0.748, outperforming C-reactive protein and erythrocyte sedimentation rate. Flow cytometric analysis suggested that platelet-derived EVs represent a predominant source of circulating miR-223-3p, and their proportion tended to be reduced in patients with aortic dilation. ConclusionsReduced platelet-derived EV-associated miR-223-3ps are associated with aortic dilation in TAK and demonstrate superior diagnostic accuracy over conventional inflammatory markers. EV miRNA profiling may provide a novel approach for evaluating vascular remodeling in TAK.

immunology↗

bioRxiv2024

Environmental Impacts of Serum-free Food-grade and Complex Culture Medium Production for Cultivated Meat

Culture medium accounts for most of the environmental impact of cultivated meat production. This study quantitatively evaluated and analyzed the environmental impact of producing a culture medium consisting of serum-free, food and complex ingredients for cultivated meat by performing a life cycle assessment (LCA) based on activity data at the laboratory scale. In addition, specific measures were proposed to reduce the environmental impact further. LCAs were performed at current and future production scales. This study also evaluated the impact of multiple electricity sources on the environmental impact of culture medium production. Energy, animal-derived materials, and expendables at the current scale, and energy, animal-derived materials, amino acids, and glucose at future scale are hotspots in the environmental impact of this culture medium production. The production of serum substitutes accounts for most of the environmental impact. As the scale shifts, the environmental impacts are expected to decrease by more than 70% in all impact categories. As the composition of electricity sources changed, the impact on certain categories decreased. However, as the share of renewable energy increased, the impact on land use also increased significantly. This study promotes the practical application of new culture-media for low-cost and low-environment-impact cultivated meat. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/611339v2_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@ac6daorg.highwire.dtl.DTLVardef@1852ef4org.highwire.dtl.DTLVardef@cdbbe8org.highwire.dtl.DTLVardef@eb8703_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstract.C_FLOATNO SYNOPSIS. This study evaluated the environmental impact of culture-medium production for cultivated meat and reports that energy, animal-derived materials, expendables, amino acids and glucose are hotspots of this impact. C_FIG

ecology↗

bioRxiv2023

Recruitment status and host-fish-limitation threats to endangered freshwater pearl mussel (Margaritifera laevis) in eastern Hokkaido, northern Japan

Recruitment failure is a major threat to freshwater mussel (Order Unionoida) populations worldwide. Assessments of the recruitment status and determining the bottleneck factors of mussel recruitment are crucial for preventing future declines in mussel populations. In this study, we investigated the recruitment status (i.e., size structure and the proportion of juveniles within a population) of the endangered freshwater pearl mussel Margaritifera laevis in 22 rivers in eastern Hokkaido, northern Japan. We also quantified the density of the host fish Oncorhynchus masou masou and examined the relationship between the proportion of juveniles and host-fish density to assess host-limitation threats to M. laevis recruitment. Our assessments showed that 13 (59.1%) rivers had no signs of recent recruitment within 10 years, with a low mean proportion of juveniles (mean:0.02 [range:0.00-0.09] fraction), indicating that these populations are threatened by sustained recruitment failure. The proportion of juveniles was positively associated with host-fish density, suggesting that host-fish limitation could be a bottleneck factor for M. laevis recruitment. These results highlight the urgent need for prompt conservation measures, including the enhancement of host-fish availability, to sustain M. laevis populations in the study region.

ecology↗

bioRxiv2021

Multiple stressors and recruitment failure of long-lived endangered freshwater mussels with a complex life cycle

O_LIMultiple stressors can interactively affect the population of organisms; however, the process by which they affect recruitment efficiency remains unclear for empirical populations. Recruitment efficiency can be regulated at multiple stages of life, particularly in organisms with complex life cycles. Understanding the interactive effects of multiple stressors on recruitment efficiency and determining the bottleneck life stages is imperative for species conservation. C_LIO_LIThe proportion of <20-year-old juveniles of the endangered freshwater pearl mussel Margaritifera togakushiensis, which has an obligate parasitic larval stage, was investigated in 24 rivers from eastern Hokkaido, northern Japan to reveal the influence of nutrients, fine sediment, and their combined effects on juvenile recruitment efficiency. The following indices for recruitment at adult, parasitic, and post-parasitic juvenile stages were obtained from 11 of these rivers: gravid female density, glochidia density (the number of glochidia infections per stream area), and juvenile survival rate. This study explored the bottleneck stages of recruitment efficiency and the interactive effects of the two stressors on these stages. C_LIO_LITwenty-four population status assessments determined that the proportion of juveniles ranged from 0.00 to 0.53, and juveniles were absent from four rivers. The results showed that the parasitic and post-parasitic juvenile stages were bottlenecks for recruitment efficiency. Juvenile survival rates had a more significant positive effect on recruitment efficiency in rivers with a high glochidia density. Juvenile survival rate was decreased by the synergistic interaction of nutrients and fine sediment, although factors limiting glochidia density were not found. C_LIO_LIThe nutrient concentration of rivers in the study region was well explained by the proportion of agricultural land cover and urban areas in the watersheds, but no relationship was detected between fine sediment abundance and land use. C_LIO_LIThis study suggests that nutrient management at a catchment scale can be effective for re-establishing the recruitment of M. togakushiensis, particularly in rivers with a high content of fine sediments. The results also emphasise the importance of considering both parasitic and post-parasitic juvenile stages of mussels to maximise the positive effects of stressor mitigation. C_LI

ecology↗