Biology subjects

Kondo, K.

Publications and source records attributed to Kondo, K..

25 records · Page 2Linked to original sources

bioRxiv2020

Expression of Ace2, Tmprss2, and Furin in mouse ear tissue

ObjectivesIntracellular entry of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) depends on the interaction between its spike protein to a cellular receptor named angiotensin-converting enzyme 2 (ACE2) and depends on Furin-mediated spike 23 protein cleavage and spike protein priming by host cell proteases including 24 transmembrane protease serine 2 (TMPRSS2). Tmprss1, Tmprss3, and Tmprss5 are expressed in the spiral ganglion neurons and the organ of Corti in the inner ear; however, Ace2, Tmprss2, and Furin expression profiles in the middle ear remain unclear. Therefore, this study aimed to analyze Ace2, Tmprss2, and Furin expression in the middle and inner ear of mice. Study DesignAnimal research. SettingDepartment of Otolaryngology and Head and Neck Surgery, University of Tokyo. MethodsWe performed immunohistochemical analysis to examine the distribution of Ace2, Tmprss2, and Furin in the eustachian tube, middle ear space, and cochlea of mice. ResultsAce2 was expressed in the cytoplasm in the middle ear epithelium, eustachian tube epithelium, stria vascularis, and spiral ganglion. Tmprss2 and Furin were widely expressed in the middle ear spaces and the cochlea. ConclusionCo-expression of Ace2, Tmprss2, and Furin in the middle ear indicates that the middle ear is susceptible to SARS-CoV-2 infections, thus warranting the use of personal protective equipment during mastoidectomy for coronavirus disease (COVID-19) patients.

microbiology↗

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↗

bioRxiv2020

Background mechanisms of olfactory dysfunction in COVID-19: expression of ACE2, TMPRSS2, and Furin in the nose and olfactory bulb in human and mice

Background Anosmia is a frequent symptom in patients with the coronavirus disease 2019 (COVID-19) driven by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and mostly recovers within weeks. This clinical figure is significantly different from that of anosmia after upper respiratory infection, which occurs in only a small proportion of patients and does not recover or requires months to recover. The background mechanisms of COVID-19 induced olfactory dysfunction have not been elucidated.Methods To address the unique pathophysiology of olfactory dysfunction associated with COVID-19, we examined the existence and distribution of ACE2 (virus binding receptor), TMPRSS2 and Furin (proteases to facilitate virus entry) in the nasal mucosa, composed of the respiratory mucosa (RM) and olfactory mucosa (OM), and the olfactory bulb (OB) in mouse and human tissues by immunohistochemistry and gene analyses.Results Ace2, Tmprss2, and Furin gene expressions were confirmed in the nasal mucosa and OB. ACE2 was widely expressed all in the RM, OM and OB. Co-expression of ACE2, TMPRSS2, and Furin was observed in the RM including the RE and subepithelial glands and in the OM, especially in the supporting cells on the olfactory epithelium and the Bowman’s glands. Notably, the olfactory receptor neurons (ORNs) in the OM were positive for ACE2 but almost negative for TMPRSS2 and Furin. The cells in the OB expressed ACE2 strongly and Furin weakly and did not express TMPRSS2.Conclusions ACE2 was widely expressed in the RM, OM and OB, but TMPRSS2 and Furin were expressed in certain types of cells and were absent in the ORNs. These findings, together with clinically reported ones, suggest that COVID-19 related anosmia can occur due to mainly sensorineural and central dysfunction and, to some extent, conductive olfactory dysfunction. That the ORNs express ACE2 but not TMPRSS2 or Furin may explain the early recovery of anosmia.Short Summary Protein expression patterns of ACE2, TMPRSS, and Furin suggest that COVID-19 related anosmia can occur due to mainly sensorineural dysfunction without olfactory neuronal damage.Competing Interest StatementThe authors have declared no competing interest.View Full Text

pathology↗

bioRxiv2019

Handling and Packaging of Medical Bags at the Acute Disaster Site Under High Temperature Conditions

The handling of medical bags in high temperature disaster sites has not been fully evaluated. In this study, medical bags were assessed in the closed, semi-opened, and opened state, with and without heat insulating material (HIM) and a coolant. The bags were heated for 300 minutes at 35 or 40{degrees}C, and the internal temperature was measured. closed and semi-opened bags were able to limit temperature increases in the central part of the bag at both 35 and 40{degrees}C to a greater extent than opened bags. When coolant and HIM were used in closed and semi-opened bags, the internal temperature was significantly lower than that seen in the opened state at 40{degrees}C (P < 0.01 and P < 0.001, respectively). In conclusion, in high temperature disaster sites, medical bags should be maintained in a semi-opened or closed state using a HIM and coolant.

scientific communication and education↗

bioRxiv2019

Physiological determinants of the increase in oxygen consumption during exercise in individuals with stroke

BackgroundUnderstanding the physiological limitations of the increase in oxygen consumption ([V]O2) during exercise is essential to improve cardiorespiratory fitness in individuals with stroke. However, the physiological determinants of the increase in [V]O2 during exercise have not been examined using multivariate analysis in individuals with stroke. This study aimed to identify the physiological determinants of the increase in [V]O2 during a graded exercise in terms of the respiratory function, cardiac function, and ability of skeletal muscles to extract oxygen.\n\nMethodsEighteen individuals with stroke (60.1 {+/-} 9.4 years of age, 67.1 {+/-} 30.8 days poststroke) underwent a graded exercise test for the assessment of cardiorespiratory response to exercise. The increase in [V]O2 from rest to ventilatory threshold and that from rest to peak exercise were measured as a dependent variable. The increases in respiratory rate, tidal volume, heart rate, stroke volume, and arterial-venous oxygen difference from rest to ventilatory threshold and those from rest to peak exercise were measured as independent variables.\n\nResultsFrom rest to ventilatory threshold, the increases in heart rate ({beta} = 0.546) and arterial-venous oxygen difference ({beta} = 0.398) were significant determinants of the increase in [V]O2 (adjusted R2 = 0.703, p < 0.001). From rest to peak exercise, the increases in tidal volume ({beta} = 0.611) and heart rate ({beta} = 0.353) were significant determinants of the increase in [V]O2 (adjusted R2 = 0.702, p < 0.001).\n\nConclusion[V]O2 is well-known to increase nearly linearly with increasing heart rate; however, our results suggest that arterial-venous oxygen difference and tidal volume are also significant physiological determinants of the increase in [V]O2 from rest to ventilatory threshold and that from rest to peak exercise, respectively. Our findings could potentially contribute to the development of appropriate therapies to improve cardiorespiratory fitness in individuals with stroke.

physiology↗

bioRxiv2018

Life in coastal pebble sediment: Unique interstitial organism community and selective feeding on meiobenthos by interstitial fishes (Luciogobius: Gobiidae)

Interstitial areas of coastal pebble sediment in the Japanese Archipelago are inhabited by extremely elongated gobies of the genus Luciogobius, which are characterized by an increased number of vertebrae and reduction of scales, eyes, and fins. To explore the little-known interstitial life of Luciogobius gobies, we investigated the diets of two interstitial Luciogobius species, L. elongatus and L. grandis, and the interstitial organism communities of the gobies microhabitats in an exposed gravelly coast in Shirahama, southern Japan. The interstitial organism community in pebbly sediment was dominated by minute arthropods such as harpacticoids, isopods, and ostracods, presenting a marked contrast to the communities in sandy sediments, which are dominated by nematodes and turbellarians. The gut contents of the two goby species were composed exclusively of interstitial organisms, especially harpacticoides and isopods. Although each prey assemblage was roughly similar to the interstitial organism community in the corresponding microhabitat, marked preferences for harpacticoids and flabelliferan isopods were detected in L. elongatus and L. grandis, respectively. Irrespective of their intense feeding of harpacticoids, rare catches of large isopods were suggested to be nutritionally important for the gobies. These results suggest that the Luciogobius gobies are the first known fishes that depend exclusively on interstitial organisms, and that selective feeding upon meiobenthos may facilitate the coexistence of several interstitial goby species in pebbly sediment.

ecology↗

bioRxiv2018

CTCF looping is established during gastrulation in medaka embryos

AbstractGenome architecture plays a critical role in gene regulation, but how the structures seen in mature cells emerge during embryonic development remains poorly understood. Here, we study early development in medaka (the Japanese killifish, Oryzias latipes) at 12 time points before, during, and after gastrulation which is the most dramatic event in early embryogenesis, and characterize transcription, protein binding, and genome architecture. We find that gastrulation is most associated with drastic changes in genome architecture, including the formation of the first loops between sites bound by the insulator protein CTCF and great increase in the size of contact domains. However, the position of CTCF is fixed throughout medaka embryogenesis. Interestingly, genome-wide transcription precedes the emergence of mature domains and CTCF-CTCF loops.

genomics↗