Modeling SARS-CoV-2 infection and its individual differences with ACE2-expressing human iPS cells

ACE発現ヒトiPS細胞を用いたSARS-CoV-2感染の個人差再現と原因究明. 京都大学プレスリリース. 2021-04-19.Stem cells show gender differences in COVID-19 risk. 京都大学プレスリリース. 2021-04-19.Genetic differences are a primary reason for differences in the susceptibility and severity of COVID-19. As induced pluripotent stem (iPS) cells maintain the genetic information of the donor, they can be used to model individual differences in SARS-CoV-2 infection in vitro. We found that human iPS cells expressing the SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) (ACE2-iPS cells) can be infected w SARS-CoV-2. In infected ACE2-iPS cells, the expression of SARS-CoV-2 nucleocapsid protein, budding of viral particles, and production of progeny virus, double membrane spherules, and double-membrane vesicles were confirmed. We performed SARS-CoV-2 infection experiments on ACE2-iPS/ embryonic stem (ES) cells from eight individuals. Male iPS/ES cells were more capable of producing the virus compared with female iPS/ES cells. These findings suggest that ACE2-iPS cells can not only reproduce individual differences in SARS-CoV-2 infection in vitro but also are a useful resource to clarify the causes of individual differences in COVID-19 due to genetic differences

Long-Term Self-Renewal of Human ES/iPS-Derived Hepatoblast-like Cells on Human Laminin 111-Coated Dishes

SummaryThe establishment of self-renewing hepatoblast-like cells (HBCs) from human pluripotent stem cells (PSCs) would realize a stable supply of hepatocyte-like cells for medical applications. However, the functional characterization of human PSC-derived HBCs was not enough. To purify and expand human PSC-derived HBCs, human PSC-derived HBCs were cultured on dishes coated with various types of human recombinant laminins (LN). Human PSC-derived HBCs attached to human laminin-111 (LN111)-coated dish via integrin alpha 6 and beta 1 and were purified and expanded by culturing on the LN111-coated dish, but not by culturing on dishes coated with other laminin isoforms. By culturing on the LN111-coated dish, human PSC-derived HBCs were maintained for more than 3 months and had the ability to differentiate into both hepatocyte-like cells and cholangiocyte-like cells. These expandable human PSC-derived HBCs would be manageable tools for drug screening, experimental platforms to elucidate mechanisms of hepatoblasts, and cell sources for hepatic regenerative therapy

Glutamatergic neurometabolite levels in the caudate are associated with the ability of rhythm production

IntroductionGlutamatergic neurometabolites play important roles in the basal ganglia, a hub of the brain networks involved in musical rhythm processing. We aimed to investigate the relationship between rhythm processing abilities and glutamatergic neurometabolites in the caudate.MethodsWe aquired Glutamatergic function in healthy individuals employing proton magnetic resonance spectroscopy. We targeted the right caudate and the dorsal anterior cingulate cortex (dACC) as a control region. Rhythm processing ability was assessed by the Harvard Beat Assessment Test (H-BAT).ResultsWe found negative correlations between the production part of the Beat Saliency Test in the H-BAT and glutamate and glutamine levels in the caudate (r = −0.693, p = 0.002) whereas there was no such association in the dACC.ConclusionThese results suggest that higher glutamatergic neurometabolite levels in the caudate may contribute to rhythm processing, especially the ability to produce meter in music precisely

Continuous Catalytic Oxidation of Glycerol to Carboxylic Acids Using Nanosized Gold/Alumina Catalysts and a Liquid-Phase Flow Reactor

Here, we report the development of catalysts comprising highly dispersed Au on an alumina (Al2O3) support for the oxidation of glycerol to high-value carboxylic acids in a liquid-phase flow reactor. The catalysts were prepared by means of a deposition–precipitation method. To ensure that the catalysts could be used for long-term catalytic conversions in a liquid-phase flow reactor, we chose an alumina support with high temperature stability and a particle size (50–200 μm) large enough to prevent leakage of the catalyst from the reactor. One of the five catalysts had a high catalytic activity for the conversion of glycerol to the high-value carboxylic acids, glyceric acid and tartronic acid (conversion of glycerol >70%), and the catalyst retained its catalytic activity over long-term use (up to 1770 min). Pretreatment of the catalyst with fructose, a mild reductant, increased the activity of the catalyst. Scanning transmission electron microscopy revealed three Au species highly dispersed on the surface of the alumina supportAu nanoparticles (mode = 7.5–10 nm), Au clusters (1–2 nm), and atomic Au

Comparison of commercially available media for hepatic differentiation and hepatocyte maintenance.

Human hepatocytes are essential materials in pharmaceutical researches. Not only primary human hepatocytes (PHH) but also human iPS cell-derived hepatocyte-like cells (human iPS-HLCs) are expected to be applied as materials for pharmaceutical researches. To date, several culture media have been developed for culturing human hepatocytes. However, there have been no reports comparing these media to determine which is most suitable for culturing human hepatocytes. In this study, we compared five commercial media (Hepatocyte Culture Medium (HCM), HepatoZYME-SFM, Cellartis Power Primary HEP Medium, DMEM/F12, and William's E Medium (WEM)) to determine which is most suitable for culturing PHH and human iPS-HLCs. In hepatic differentiation of human iPS cells (day 14-25 of differentiation), albumin (ALB) and urea secretion abilities and CYP2C9, CYP2C19, and CYP3A4 activities were the highest when using HCM or WEM. During maintenance of human iPS-HLCs, ALB and urea producing abilities and CYP2C9, CYP2C19, and CYP3A4 activities were the highest when using HCM. Importantly, we found that human iPS-HLCs cultured in HCM were maintained for 3 weeks or more without impairment of their hepatic functions. These results suggest that it is necessary to select an optimal medium for hepatic differentiation and maintenance of human iPS-HLCs. In the case of PHH culture, there was little difference in hepatic functions among the five media. However, the CYP2C9, CYP2C19, and CYP3A4 activities were the highest when using HCM and WEM. In conclusion, it is important to select the optimal medium for specific application when carrying out pharmaceutical researches using human hepatocytes

Performance of plasma Aβ42/40, measured using a fully automated immunoassay, across a broad patient population in identifying amyloid status

Abstract Background Plasma biomarkers have emerged as promising screening tools for Alzheimer’s disease (AD) because of their potential to detect amyloid β (Aβ) accumulation in the brain. One such candidate is the plasma Aβ42/40 ratio (Aβ42/40). Unlike previous research that used traditional immunoassay, recent studies that measured plasma Aβ42/40 using fully automated platforms reported promising results. However, its utility should be confirmed using a broader patient population, focusing on the potential for early detection. Methods We recruited 174 participants, including healthy controls (HC) and patients with clinical diagnoses of AD, frontotemporal lobar degeneration, dementia with Lewy bodies/Parkinson’s disease, mild cognitive impairment (MCI), and others, from a university memory clinic. We examined the performance of plasma Aβ42/40, measured using the fully automated high-sensitivity chemiluminescence enzyme (HISCL) immunoassay, in detecting amyloid-positron emission tomography (PET)-derived Aβ pathology. We also compared its performance with that of Simoa-based plasma phosphorylated tau at residue 181 (p-tau181), glial fibrillary acidic protein (GFAP), and neurofilament light (NfL). Results Using the best cut-off derived from the Youden Index, plasma Aβ42/40 yielded an area under the receiver operating characteristic curve (AUC) of 0.949 in distinguishing visually assessed 18F-Florbetaben amyloid PET positivity. The plasma Aβ42/40 had a significantly superior AUC than p-tau181, GFAP, and NfL in the 167 participants with measurements for all four biomarkers. Next, we analyzed 99 participants, including only the HC and those with MCI, and discovered that plasma Aβ42/40 outperformed the other plasma biomarkers, suggesting its ability to detect early amyloid accumulation. Using the Centiloid scale (CL), Spearman’s rank correlation coefficient between plasma Aβ42/40 and CL was -0.767. Among the 15 participants falling within the CL values indicative of potential future amyloid accumulation (CL between 13.5 and 35.7), plasma Aβ42/40 categorized 61.5% (8/13) as Aβ-positive, whereas visual assessment of amyloid PET identified 20% (3/15) as positive. Conclusion Plasma Aβ42/40 measured using the fully automated HISCL platform showed excellent performance in identifying Aβ accumulation in the brain in a well-characterized cohort. This equipment may be useful for screening amyloid pathology because it has the potential to detect early amyloid pathology and is readily applied in clinical settings

神戸女学院の排水中の有機物、界面活性剤、窒素およびリンの濃度

神戸女学院内の排水および下水道管への接続部分で採水を行い、有機物、陰イオン界面活性剤、窒素およびリンの濃度を測定した。中高等部からは有機物、窒素およびリンの負荷が多く、学生寮からはこれらの物質に加えて、陰イオン界面活性剤の排水中への負荷が大きかった。さらに、中高等部からの寄与が大きい地点では、午前と午後の濃度の差はほとんど求められないが、学生寮からの排水は、午前の方が午後に比べ濃度が高い傾向がみとめられた。また、11月-12月にかけて、陰イオン界面活性剤の濃度に大きな変化は認められなかった。The concentrations of organic substances, anionic surfactant, total nitrogen and total phosphorous in discharged water from Kobe College were measured. Organic substances, total nitorogen and total phosphorous were discharged into drainage water from the dormitory was high. Although the differences of the concentrations of anionic surfactants between morning and afternoon were not observed in the junior high school, the concentrations of anionic surfactant in drainage water from the dormitory in the morning were higher than those in the afternoon. The drastic change of anionic surfactant concentrations were not observed between November and December

HHEX Promotes Hepatic-Lineage Specification through the Negative Regulation of Eomesodermin

<div><p>Human embryonic stem cells (hESCs) could provide a major window into human developmental biology, because the differentiation methods from hESCs mimic human embryogenesis. We previously reported that the overexpression of hematopoietically expressed homeobox (HHEX) in the hESC-derived definitive endoderm (DE) cells markedly promotes hepatic specification. However, it remains unclear how HHEX functions in this process. To reveal the molecular mechanisms of hepatic specification by HHEX, we tried to identify the genes directly targeted by HHEX. We found that HHEX knockdown considerably enhanced the expression level of eomesodermin (EOMES). In addition, HHEX bound to the HHEX response element located in the first intron of EOMES. Loss-of-function assays of EOMES showed that the gene expression levels of hepatoblast markers were significantly upregulated, suggesting that EOMES has a negative role in hepatic specification from the DE cells. Furthermore, EOMES exerts its effects downstream of HHEX in hepatic specification from the DE cells. In conclusion, the present results suggest that HHEX promotes hepatic specification by repressing EOMES expression.</p></div