Inhibitory Effects of Chlorella Extract on Airway Hyperresponsiveness and Airway Remodeling in a Murine Model of Asthma

Chlorella extract （CE） has been shown to induce production of T helper-1 cytokines, and regulate serum IgE levels in animal models of asthma. We aimed to evaluate whether CE could inhibit ovalbumin （OVA）-induced airway hyperresponsiveness （AHR） and airway remodeling in a murine model of asthma. Balb/c mice were allocated to four groups: a control group （no OVA exposure, not given CE）, a CE group （no OVA exposure, given CE）, an asthma group （sensitized/challenged with OVA, not given CE） and a CE＋asthma group （sensitized/challenged with OVA, given CE）. In the asthma and CE＋asthma groups, mice were sensitized with OVA on day 0 and day 12, and then challenged with OVA on three consecutive days. In the CE and CE＋asthma groups, the mice were given feed containing 2％ CE. We assessed AHR to methacholine, and analyzed bronchoalveolar lavage fluid （BALF）, serum, lung tissue and spleen cells. Administration of CE was associated with significantly lower AHR in OVA-sensitized and challenged mice. CE administration was also associated with marked reduction of total cells, eosinophils and T helper-2 cytokines （IL-4, IL-5 and IL-13） in BALF. In addition, administration of CE significantly decreased the numbers of periodic acid-Schiff （PAS）-positive cells in OVA-sensitized and challenged mice. Administration of CE also directly suppressed IL-4, IL-5 and IL-13 production in spleen cells of OVA-sensitized and challenged mice. These results indicate that CE can partly prevent AHR and airway remodeling in a murine model of asthma

Long-term follow-up of production of IgM and IgG antibodies against SARS-CoV-2 among patients with COVID-19

The patients diagnosed with coronavirus disease 2019 （COVID-19） produce IgM and IgG antibodies against severe acute respiratory syndrome coronavirus 2 （SARS-CoV-2）. However, the frequency and duration of antibody production still need to be fully understood. In the present study, we investigated the duration of antibody production after SARS-CoV-2 infection. The patients diagnosed with COVID-19 were monitored over twelve months for the production of SARS-CoV-2 IgM and IgG antibodies, and the characteristics of these patients were examined. Forty-five patients diagnosed with COVID-19 were enrolled, and thirty-four patients were followed up until they tested negative for SARS-CoV-2 IgM and IgG antibodies or up to twelve months after the date of a negative SARS-CoV-2 polymerase chain reaction （PCR） result. The positivity rates of SARS-CoV-2 IgM and IgG antibodies were 27.3％ and 68.2％ when SARS-CoV-2 PCR was negative, 20.6％ and 70.6％ after one month, 8.8％ and 52.9％ after three months, and 0.0％ and 14.7％ after six months, respectively. Moreover, we compared patients with milder conditions who did not require oxygen administration with those with severe conditions which required oxygen administration. The positivity rate of SARS-CoV-2 IgG antibodies was significantly higher in patients with severe conditions than in those with milder conditions on the date of a negative SARS-CoV-2 PCR result and after one month and three months, but not after six months. Patients with more severe COVID-19 produced more SARS-CoV-2 IgG antibodies. Moreover, it is suggested that the duration of IgG antibody production is independent of COVID-19 severity

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

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

Indirect Comparison of Dupilumab and Mepolizumab Treatments for Uncontrolled Eosinophilic Asthma-Bayesian Analysis of Randomized Controlled Trials-

The efficacy and safety of dupilumab, a humanized interleukin （IL）-4 receptor alfa monoclonal antibody （mAb） that inhibits the signaling of the type 2 cytokines IL-4 and IL-13, for the treatment of uncontrolled eosinophilic asthma remains to be fully characterized, particularly in comparison to other therapeutic mAbs. Therefore, we conducted a meta-analysis of randomized controlled trials （RCTs） to indirectly compare the efficacy and safety of dupilumab with those of mepolizumab, a humanized anti-IL-5 mAb, in patients with uncontrolled eosinophilic asthma. Comparisons were made using the Bayesian statistical method. This meta-analysis complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses （PRISMA） guidelines. Six RCTs were eligible for this study: two RCTs focused on dupilumab and four on mepolizumab. The primary efficacy outcome was a change in the forced expiratory volume at 1.0 second （FEV1.0）, and the primary safety outcome was the incidence of severe adverse effects （SAE）. The mean difference in changes in the FEV1.0 following treatment with dupilumab versus mepolizumab was 0.133 （95% CI, 0.016-0.252）. There was no significant difference between these two agents in the incidence of SAE （OR, 1.99; 95% CI, 0.19-11.16）. These results strongly indicate that dupilumab is more effective than mepolizumab and is generally well-tolerated in patients with uncontrolled eosinophilic asthma

Correlation of Arterial CO2 and Respiratory Impedance Values among Subjects with COPD

Chronic obstructive pulmonary disease (COPD) is a respiratory illness characterized by airflow limitation and chronic respiratory symptoms with a global prevalence estimated to be more than 10% in 2010 and still on the rise. Furthermore, hypercapnic subject COPD leads to an increased risk of mortality, morbidity, and poor QoL (quality of life) than normocapnic subjects. Series of studies showed the usefulness of the forced oscillation technique (FOT) to measure small airway closure. Traditional findings suggested that hypercapnia may not be the main treating targets, but recent findings suggested that blood stream CO2 may lead to a worse outcome. This study aimed to seek the relationship between CO2 and small airway closure by using FOT. Subjects with COPD (n = 124; hypercapnia 22 and normocapnia 102) were analyzed for all pulmonary function values, FOT values, and arterial blood gas analysis. Student’s t-test, Spearman rank correlation, and multi linear regression analysis were used to analyze the data. COPD subjects with hypercapnia showed a significant increase in R5, R20, Fres, and ALX values, and a greater decrease in X5 value than normocapnic patients. Also, multiple linear regression analysis showed R5 was associated with hypercapnia. Hypercapnia may account for airway closure among subjects with COPD and this result suggests treating hypercapnia may lead to better outcomes for such a subject group