Biology subjects

Okabe, H.

Publications and source records attributed to Okabe, H..

5 recordsLinked to original sources

bioRxiv2026

A Passive-Oxygenation Silicone Platform for Biomass Production: Maximizing Labor Productivity and Process Efficiency in Cellular Agriculture Development

The commercial production of cell-based food is currently hindered by existing bioreactor technologies, which require substantial capital investment, specialized operating skills, and complex processing setups. To democratize cell-based food production, we developed the "oxy-thru cultivator"--a simple, autoclavable, closed-bag bioreactor fabricated from polydimethylsiloxane (PDMS). By leveraging the high oxygen-permeability of PDMS, this platform enables passive oxygenation across the entire vessel wall, eliminating the need for external aeration or mechanical sparging. During testing, the cultivator maintained a stable culture environment over 23 days, showing no cytotoxic leachables and retaining both structural integrity and sterility across 10 autoclave cycles. This robustness supported the continuous cultivation of DF-1 cells for 74 days. Using a standardized subculture scheme, we successfully harvested an estimated 2.60 g of cell-based biomass per cultivator over five passages. Notably, the platform achieved a 127% monthly labor productivity compared to conventional bioreactors and was easily operated by researchers without specialized training. Additionally, the system successfully supported the expansion of both mammalian and primary avian cell lines. With a minimal equipment footprint that reduces CapEx, and a reusable silicone vessel that lowers OpEx, the oxy-thru cultivator offers a highly practical, accessible pathway toward scaling up cellular agriculture. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/729703v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@644879org.highwire.dtl.DTLVardef@1d23680org.highwire.dtl.DTLVardef@1f83d9forg.highwire.dtl.DTLVardef@959bf7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2025

Proteome-level robustness and the role of a histone-like protein during acute heat shock in the hyperthermophilic archaeon Pyrococcus furiosus

The hyperthermophilic archaeon Pyrococcus furiosus thrives in extreme temperatures and exhibits a complex response to heat shock. However, the regulatory dynamics of genetic information during heat shock remain poorly understood. In this study, we exposed P. furiosus (cultured at 90{degrees}C) to acute heat shock by boiling (101-102{degrees}C) and analyzed its transcriptomic and proteomic responses. The levels of 16S and 23S rRNAs and of total tRNA were decreased by approximately 50%, and pre-tRNA splicing was inhibited, indicating suppression of translation. By contrast, approximately 90% of the proteome remained stable, underscoring the robustness of existing proteins. However, the transcriptome exhibited widespread alterations with limited correlation to the proteome (correlation coefficient r = 0.32), except for a few key proteins. These proteins included PF1883 (small heat shock protein), PF1385 (uracil-DNA glycosylase), and PF1616 (inositol-1-phosphate synthase), which are involved in protein chaperoning, stress-related metabolite synthesis, and DNA repair, respectively. Additionally, PF0624, previously annotated as a hypothetical protein, was identified as a putative histone motif-containing protein. Experimental evidence suggests that PF0624 may contribute to chromatin formation via archaeal histones in P. furiosus. In summary, our findings reveal that P. furiosus responds to acute heat shock by maintaining protein stability, suppressing translation, limiting genomic damage, and potentially compacting genomic DNA into archaeal chromatin. IMPORTANCEHyperthermophilic archaea, such as Pyrococcus furiosus, thrive in extreme environments where the temperatures may reach up to 100{degrees}C. However, the precise mechanisms by which these organisms protect their genomic DNA from heat-induced damage remain incompletely understood. In this study, we propose that PF0624, a histone-like protein that is transcriptionally induced and translated in response to acute heat shock, is critical in stabilizing archaeal chromatin structure through histone-mediated mechanisms. Our results highlight the sophisticated molecular strategies employed by P. furiosus to survive extreme thermal stress.

molecular biology↗

bioRxiv2024

Integrated hepatic ferroptosis gene signature dictates pathogenic features of ferroptosis

Background & AimsFerroptosis, a distinctive form of cell death induced by iron-dependent lipid peroxidation, is implicated in various biological processes, including liver diseases. Establishing an iron overload-induced ferroptosis model and identifying hepatic gene signatures associated with ferroptosis are crucial for understanding its role in liver pathogenesis. MethodsF-box and leucine-rich repeat protein 5 (FBXL5) is a substrate-recognition component of the SCF E3 ligase complex that restricts intracellular iron levels. In this study, we used liver-specific Fbxl5-null mice to establish an iron overload-induced ferroptosis model. Transcriptome analysis identified genes involved in hepatic ferroptosis. Integrating these gene signatures with another ferroptosis model enabled the assessment of ferroptosis-related pathology in murine liver injury models and in 174 patients undergoing liver resection surgery. ResultsIron overload induced severe liver damage in liver-specific Fbxl5-null mice, characterized by elevated liver enzymes, histopathological changes, and lipid peroxidation. Transcriptome analysis revealed a distinct set of genes associated with hepatic ferroptosis response. Generating a gene signature for evaluating ferroptosis enhanced the understanding of ferroptosis-related pathologies in liver diseases. Iron overload exacerbated liver damage in murine ischemia-reperfusion injury models via ferroptosis induction. In human patients, elevated serum iron levels correlated with sustained post-operative liver damage, indicating heightened susceptibility to ferroptosis. ConclusionHere, a murine model of iron overload-induced hepatic ferroptosis was established, and a gene signature indicative of hepatic ferroptosis response in both mice and humans was identified. These findings underscore the role of ferroptosis in liver injury progression and suggest potential therapeutic targets for liver disease intervention. HIGHLIGHTSO_LILiver-specific Fbxl5 knockout mice provide an iron-induced ferroptotic injury model C_LIO_LIIntegrated gene signature of iron- and acetaminophen-induced liver injury dictates ferroptosis C_LIO_LIIron overload aggravates hepatic ischemia-reperfusion injury in mice C_LIO_LIPatients with high iron levels show delayed post-operative liver damage recovery C_LI IMPACT AND IMPLICATIONSOur study elucidated the critical role of iron in liver disease pathogenesis and ischemia-reperfusion injury (IRI). By establishing a murine model of iron overload-induced ferroptosis, we confirmed that iron overload exacerbated hepatic IRI, underscoring the importance of ferroptosis in liver damage. Additionally, the development of an integrated gene signature for hepatic ferroptosis response provides a valuable tool for evaluating ferroptosis in liver diseases. Via analysis of patient data, we also highlighted the clinical relevance of ferroptosis in post-operative liver damage, offering insights into potential therapeutic strategies targeting iron and ferroptosis to improve outcomes in patients with liver diseases.

molecular biology↗

bioRxiv2023

Evidence of the simultaneous replications of active viruses in specimens positive for multiple respiratory viruses

Genetic diagnostic assays for the detection of respiratory viruses sometimes show simultaneous multiple infections with low copy numbers. In such cases, the disease is considered caused by a single etiologic agent and others are nonspecific reactions and/or contaminations. Interferon-dependent interference is seen in dual infections of influenza and respiratory syncytial virus, which are the main causes of respiratory infections. Virus isolation is one of the solutions in detecting other active viruses present in specimens, and the air-liquid interface culture of human bronchial/tracheal epithelial cells (HBTEC-ALI) is optimal for the isolation of respiratory viruses owing to its wide range of susceptibility. In this study, we successfully confirmed the replications of various viruses from specimens with low copy numbers and passed 2-3 viruses simultaneously using HBTEC-ALI cultures, mainly including human bocavirus 1 and/or human rhinovirus.

microbiology↗

bioRxiv2022

Inflammatory response induced in pulmonary embolic lung: Evaluation usinga reproducible murine pulmonary embolism model.

BackgroundSince previously established models of pulmonary embolism showed a large variability in the degree of ischemia, it is difficult to assess the pathophysiological response in the lung after embolization. Here, we established a model of pulmonary embolism by certain amount of relatively small thrombi, in which the degree of ischemia was reproducible. MethodsThrombi with a maximum diameter of 100 m or 500 m were administered intravenously under anesthesia, and the survival ratio at 4 hours was evaluated. The location of thrombi in the lung was visualized by administration of fluorescent-labeled thrombus, and the hemodynamics of the lung after administration of thrombi was evaluated. CT angiography was also performed to evaluate the ratio of the embolized vessels. In addition, cytokine mRNAs was quantified 4 hours in embolized lung. Immunohistochemical analysis for interleukin (IL)-6 and CD68 as a marker of macrophages were also performed. ResultsIt was found that mice with 100 m clots, but not with 500 m clots, showed a dose-dependence of survival between 2.3 L/g and 3.0 L/g at 4 hours from embolization induction. In mice treated with 2.5 L/g of 100 m thrombus, thrombi were located in the peripheral region of the lung, which was consistent with the disruption of blood circulation the peripheral region. In addition, about 60% of the vessels with a diameter of less than 100 m were occluded in these mice. In the lungs after 4 hours of embolization, IL-6 mRNA and tumor necrosis factor (TNF)- mRNA were significantly higher and lower than control lungs. IL-6 was expressed in CD68-positive macrophages in both embolized and control lungs after 4 hours of embolization, and the number of each positive cells were comparable in both embolized and control lungs. ConclusionsThese results show that the pulmonary embolization model induced by a certain amount of small thrombus is useful for evaluating the pathological responses in the embolized lung. Furthermore, it was found that IL-6 expression was increased in macrophages in the embolized lung, indicating that inflammatory responses may contribute to the pathogenesis of pulmonary embolism.

pathology↗