Biology subjects

Yamauchi, A.

Publications and source records attributed to Yamauchi, A..

3 recordsLinked to original sources

bioRxiv2026

A single-nucleus and spatial transcriptomic atlas of the Syrian hamster preoptic area across hibernation states

Hibernation is an extreme physiological state in certain mammals that is characterized by a reversible reduction in metabolic and thermogenic demands. Although the preoptic area has been implicated in the regulation of hibernation, comprehensive molecular and spatial resources for this brain region in hibernating mammals remain limited. Here, we present an integrated transcriptomic resource of the preoptic area generated using single-nucleus RNA sequencing (snRNA-seq) and Xenium-based spatial transcriptomics in a mammalian hibernator, Syrian hamster. The resource includes cross-species transcriptomic annotations relative to mouse preoptic area datasets, seasonal snRNA-seq datasets obtained under non-hibernating and hibernating conditions, and spatially resolved cell-type annotations generated from Xenium profiling. Together, these datasets provide a reference framework for identifying neuronal populations, examining molecular conservation across species and conditions, and integrating transcriptomic identity with spatial organization.

neuroscience↗

bioRxiv2023

Identification of genes supporting cold resistance of mammalian cells: lessons from a hibernator

Susceptibility of human cells to cold stress restricts the use of therapeutic hypothermia and long-term preservation of organs at low temperatures. In contrast, cells of mammalian hibernators possess remarkable cold resistance, but little is known about the molecular mechanisms underlying this phenomenon. In this study, we conducted a gain-of-function screening of genes that confer cold resistance to cold-vulnerable human cells using a cDNA library constructed from the Syrian hamster, a mammalian hibernator, and identified Gpx4 as a potent suppressor of cold-induced cell death. Additionally, genetic or pharmacological inhibition of Gpx4 in a hamster cell line under prolonged cold culture led to cell death, which resembles ferroptosis characterized by accumulation of lipid peroxide and ferrous iron dependency. Genetic disruption of other ferroptosis-suppressing pathways, namely biopterin synthesis and mitochondrial or plasma membrane CoQ reduction pathways, accelerated cold-induced cell death under Gpx4 dysfunction. Collectively, ferroptosis-suppressing pathways protect the cells of a mammalian hibernator from cold-induced cell death and the augmentation of these pathways renders cold resistance to cells of non-hibernators, including humans.

cell biology↗

bioRxiv2020

Expression of ACE2 and TMPRSS2 proteins in the upper and lower aerodigestive tracts of rats

Objective Patients with coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibit not only respiratory symptoms but also symptoms of chemo-sensitive disorders and kidney failure. Cellular entry of SARS-CoV-2 depends on the binding of its spike protein to a cellular receptor named angiotensin-converting enzyme 2 (ACE2), and the subsequent spike protein-priming by host cell proteases, including transmembrane protease serine 2 (TMPRSS2). Thus, high expression of ACE2 and TMPRSS2 are considered to enhance the invading capacity of SARS-CoV-2.Methods To elucidate the underlying histological mechanisms of the aerodigestive disorders caused by SARS-CoV-2, we investigated the expression of ACE2 and TMPRSS2 proteins in the aerodigestive tracts of the tongue, hard palate with partial nasal tissue, larynx with hypopharynx, trachea, esophagus, lung, and kidney of rats through immunohistochemistry.Results Strong co-expression of ACE2 and TMPRSS2 proteins was observed in the nasal respiratory epithelium, trachea, bronchioles, alveoli, kidney, and taste buds of the tongue. Remarkably, TMPRSS2 expression was much stronger in the peripheral alveoli than in the central alveoli. These results coincide with the reported clinical symptoms of COVID-19, such as the loss of taste, loss of olfaction, respiratory dysfunction, and acute nephropathy.Conclusions A wide range of organs have been speculated to be affected by SARS-CoV-2 depending on the expression levels of ACE2 and TMPRSS2. Differential distribution of TMPRSS2 in the lung indicated the COVID-19 symptoms to possibly be exacerbated by TMPRSS2 expression. This study might provide potential clues for further investigation of the pathogenesis of COVID-19.Level of Evidence NACompeting Interest StatementThe authors have declared no competing interest.View Full Text

pathology↗