The Expression Level of HIV-1 Vif Is Optimized by Nucleotide Changes in the Genomic SA1D2prox Region during the Viral Adaptation Process

HIV-1 Vif plays an essential role in viral replication by antagonizing anti-viral cellular restriction factors, a family of APOBEC3 proteins. We have previously shown that naturally-occurring single-nucleotide mutations in the SA1D2prox region, which surrounds the splicing acceptor 1 and splicing donor 2 sites of the HIV-1 genome, dramatically alter the Vif expression level, resulting in variants with low or excessive Vif expression. In this study, we investigated how these HIV-1 variants with poor replication ability adapt and evolve under the pressure of APOBEC3 proteins. Adapted clones obtained through adaptation experiments exhibited an altered replication ability and Vif expression level compared to each parental clone. While various mutations were present throughout the viral genome, all replication-competent adapted clones with altered Vif expression levels were found to bear them within SA1D2prox, without exception. Indeed, the mutations identified within SA1D2prox were responsible for changes in the Vif expression levels and altered the splicing pattern. Moreover, for samples collected from HIV-1-infected patients, we showed that the nucleotide sequences of SA1D2prox can be chronologically changed and concomitantly affect the Vif expression levels. Taken together, these results demonstrated the importance of the SA1D2prox nucleotide sequence for modulating the Vif expression level during HIV-1 replication and adaptation

〔研究ノート〕卵巣摘除された慢性腎臓病モデルラットの骨代謝維持に 対する食餌アルギニンあるいは大豆イソフラボン抽出物 投与の有効性評価に関する基礎的研究

The present study was carried out to elucidate the protective effects of dietary L-arginine and soy isoflavone-extracted on the bone metabolism in the ovariectomized chronic kidney disease model rats.　　Nine-week-old female rats received 360mg/kg BW of adenine intragastrally for four consecutive days so that they would develop chronic kidney disease（CKD）. After six days of recovery, rats received ovariectomies（OVX）under anesthesia. A sham operation was carried out on another group of rats（group Intact）.　　Seven days after the OVX, the rats were given either a control diet（20％ casein protein diet（group CA）; 0.5％ L-arginine supplemented diet（group Arg）; or 0.20％ soy isoflavone-extracted supplemented diet（group IF）, 13g per day for 12 weeks. Rats in group Intact were, like group CA, given the control diet.　　The results were as follows: 1）Group CA developed moderate chronic kidney disease which was manifested as elevated kidney weight, increased serum creatinine, relatively lower creatinine clearance and reduced femoral-BMD than that of group Intact.2）The L-Arginine supplemented diet did not improve renal function and femoral BMD-loss. But, increased mRNA expression levels of IGF-1, BMP-2 and Osterix were observed in the femurs.3）Soy isoflavone-extracted supplemented diet had no preventative effects on BMD loss, although estrogen receptor-beta mRNA expression levels in the femurs were elevated.　　From these results, bone-protective functions of L-arginine via activation of osteoblast differentiation and bone formation process were suggested. Further investigation to clarify the efficacy of L-arginine-IGF-1 signal transduction on the bone metabolism is required to determine whether a therapy based on this approach can help people suffering from osteoporosis in CKD patients

Evaluation of a Triage Checklist for Mild COVID-19 Outpatients in Predicting Subsequent Emergency Department Visits and Hospitalization during the Isolation Period: A Single-Center Retrospective Study

Managing mild illness in COVID-19 and predicting progression to severe disease are concerning issues. Here, we investigated the outcomes of Japanese patients with mild COVID-19, and identified triage risk factors for further hospitalization and emergency department (ED) visits at a single tertiary hospital. A triage checklist with 30 factors was used. Patients recommended for isolation were followed up for 10 days for subsequent ED visits or hospital admission. Overall, 338 patients (median age, 44.0; 45% women) visited the clinic 5.0 days (median) after symptom onset. Thirty-six patients were immediately hospitalized following triage; others were isolated. In total, 72 non-hospitalized patients visited the ED during their isolation, and 30 were hospitalized after evaluation for oxygen desaturation. The median ED visit and hospitalization durations after symptom onset were 5.0 and 8.0 days, respectively. The checklist factors associated with hospitalization during isolation were age > 50 years, body mass index > 25 kg/m2, hypertension, tachycardia with pulse rate > 100/min or blood pressure > 135 mmHg at triage, and >3-day delay in hospital visit after symptom onset. No patients died. Altogether, 80% of patients with mild COVID-19 could be safely isolated at home. Age, BMI, underlying hypertension, date after symptom onset, tachycardia, and systolic blood pressure at triage might be related to later hospitalization

Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life

Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PALand PPOpathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Contextualization cues and footing in Japanese-English bilingual storytelling activities

本研究は、ハワイで幼児期から日本語・英語の二言語に接する環境にいる男女6人のバイリンガル児(5;0-7;11)のうち、童話の語りにおける日本語と英語の言語の切り替えを調べた。その中で、子供たちによる言語の切り替えが、どのような参与者のいる枠組みで、どのような自己の位置づけに基づいて決められているのかをcontextualization cue (Gumperz, 1982), footing (Goffman, 1981)を用いて分析した。分析の結果、バイリンガル児の言語選択は、童話を語るタスクの中で、談話中の様々なコミュニケーション機能を表すために使われていたことがわかった。多くの場合、言語が切り替わる際、その言語使用は異なるコンテクストを表し、単に童話の情景描写を行っているわけではないことを示した。またオーディエンスとして子供たちが参加した際には、話者自身の位置づけが変化し、言語の切り替えにつながっていた

Single-Cell Imaging of Caspase-1 Dynamics Reveals an All-or-None Inflammasome Signaling Response

Inflammasome-mediated caspase-1 activation is involved in cell death and the secretion of the proinflammatory cytokine interleukin-1β (IL-1β). Although the dynamics of caspase-1 activation, IL-1β secretion, and cell death have been examined with bulk assays in population-level studies, they remain poorly understood at the single-cell level. In this study, we conducted single-cell imaging using a genetic fluorescence resonance energy transfer sensor that detects caspase-1 activation. We determined that caspase-1 exhibits all-or-none (digital) activation at the single-cell level, with similar activation kinetics irrespective of the type of inflammasome or the intensity of the stimulus. Real-time concurrent detection of caspase-1 activation and IL-1β release demonstrated that dead macrophages containing activated caspase-1 release a local burst of IL-1β in a digital manner, which identified these macrophages as the main source of IL-1β within cell populations. Our results highlight the value of single-cell analysis in enhancing understanding of the inflammasome system and chronic inflammatory diseases

Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F3SiCH2CH2Si(CH3)3 vapor

Site-specific fragmentation caused by Si:2p core-level photoionization of F3SiCH2CH2Si(CH3)3 vapor was studied by means of high-resolution energy-selected-electron photoion-photoion triple-coincidence spectroscopy. The ab initio molecular orbital method was used for the theoretical description. F3SiCH2CH2+- Si(CH3)3+ ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three methyl groups, and SiF+-containing ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three F atoms