Biology subjects

Fukuchi, K.

Publications and source records attributed to Fukuchi, K..

4 recordsLinked to original sources

bioRxiv2025

MiR-34a deficiency enhances nucleic acid sensing and type I IFN signaling in a mouse model of Alzheimer's disease

MiR-34a is implicated in aging, cell senescence, inflammation, and neurodegenerative diseases. In order to investigate the role of miR-34a in Alzheimers disease (AD), we produced an AD mouse model, Tg-SwDI mice, with whole body/constitutive miR-34a knockout (KO). MiR-34a KO improved long-term memory in Tg-SwDI mice, which was associated with decreases in the ratio of insoluble A{beta}42 to A{beta}40 and with increases in soluble and insoluble A{beta}40 in the cerebral cortex. Anti-Iba1 immunofluorescence revealed increases in activated microglia. Bulk RNA-sequencing of the hippocampus followed by a gene set enrichment analysis (Enrichr) identified "cellular response to type I interferon" and "type I interferon signaling pathway" as the most prominent gene sets in miR-34a KO Tg-SwDI mice compared to miR-34a wild-type Tg-SwDI mice. Many interferon-stimulated genes (ISGs) that characterize interferon responsive microglia (IRM) were upregulated in miR-34a KO Tg-SwDI mice. MiR-34a knockdown strongly enhanced ISGs expression in TLR7 ligand-stimulated BV2 microglia. These results suggest that miR-34a inhibits the transition of microglia to the IRM state that may modulate synaptic and cognitive functions in neurodegenerative diseases and aging.

neuroscience↗

bioRxiv2023

Background environment modulates motor contagions in humans

Motor contagions refer to implicit effects in ones actions induced by the observation of actions made by others. A plethora of studies over the last two decades have exhibited that observed, as well as predicted, actions can induce various kinds of motor contagions in a human observer. However, motor contagion has always been investigated in regard to different features of an observed action and it remains unclear whether the environment, in which an observed action takes place, modulates motor contagions as well. Here we investigated the effect of the observed environment on motor contagions using an empirical hand steering task in which the participants were required to move a cursor through visual channels of different shapes. We observed the movement time of observers to be influenced by both the movement of the cursor they observed, as well as the background (channel shape) in which the cursor movement was observed. Observers consistently made faster movements after observing steering movements in a narrowing channel compared to a widening channel. These results show a distinct effect of the environment, in which an observed action occurs, on ones own movement.

neuroscience↗

bioRxiv2020

Infrared absorptions as indicators for Pseudomonas aeruginosa and Acinetobacter baumannii

There is clinical demand for simple and contact-free diagnosis techniques in medical practice. This study shows that the infrared absorptions of volatile metabolites can be used to distinguish between the air around Pseudomonas aeruginosa, Acinetobacter baumannii, other bacteria, and normal room air. Gas samples were collected from the air surrounding single and mixed laboratory cultures, and preliminary data on human breath samples are also presented. The infrared spectra of a variety of gasses are measured with a high resolution of 0.5 cm-1 to obtain information about the wavenumber position of the key bands. Hence, it is not necessary to specify the molecular species of biomarkers. This work also shows that discrimination rates can be improved by observing additional infrared absorptions caused by different characteristic volatile molecules. The significance of this work is that the specific wavenumber positions of the key bands that allow the application of infrared lasers are provided. As a result, it is considered that Pseudomonas aeruginosa and Acinetobacter baumannii can be monitored more sensitively and easily. With further research and development, this simple approach could be used in future applications to identify infections in healthcare settings.

microbiology↗

bioRxiv2019

Monitoring quinolone resistance due to Haemophilus influenzae mutations (2012-17)

Among drug-resistant bacteria of recent concern, we determined minimum inhibitory concentrations (MICs) of six different quinolone antibacterial agents in Haemophilus influenzae and performed molecular genetic analysis in addition to the exploration for {beta}-lactamase-producing and {beta}-lactamase negative ampicillin-resistant H. influenzae (BLNAR). A total of 144 clinical H. influenzae strains isolated at the Showa University Hospital between 2012 and 2017 were subjected to MIC determination for penicillin/quinolone antibacterial agents using the nitrocefin method and the Clinical and Laboratory Standards Institute broth microdilution method. Moreover, amino acid mutations in the quinolone resistance-determining regions (QRDRs) were analyzed in the isolates showing MIC value of [≥] 0.25 {micro}g/ml of quinolone antibacterial agents. Increasing proportions of BLNAR were noted, with 15% in 2015 to 43.5% in 2016 and 63.6% in 2017. Among quinolone antibacterial agents, all isolates remained susceptible to sitafloxacin (STFX), and STFX showed strong inhibitory potencies against both DNA gyrase and topoisomerase IV. For moxifloxacin (MXF), however, strains with MIC value of 0.5 {micro}g/ml were detected every year since 2013 except 2015. Amino acid mutations were investigated in 17 isolates (11.8%) with MXF MIC value of [≥]0.25 {micro}g/ml, and confirmed in 11 isolates (7.6%), of which mutations of GyrA were found in 9 isolates. Future antibacterial drug regimens may need to address the emergence of quinolone-resistant H. influenzae.

molecular biology↗