Net sodium balances in humans are maintained through various ion transporters expressed along the entire nephron. Among these ion transporters, epithelial sodium channels (ENaC) located along the aldosterone-sensitive distal nephron (ASDN) play a pivotal role in the homeostasis of sodium balance. This is supported by analyses of inherited hypertensive disorders, showing that genes encoding ENaC and other modulatory proteins cause hereditary hypertension, such as Liddle syndrome. Among various modulating proteins, E3 ubiquitin ligase, Nedd4L, binds the PY motif of ENaC COOH terminals and catalyzes ubiquitination of the NH ₂ terminus of the protein for subsequent degradation. Both evolutionarily conserved and evolutionarily new C2 domains of human Nedd4L, a cryptic splice variant resulting in a disrupted isoform product formed by a frame-shift mutation, were reported previously. We focused on one of the isoforms, isoform I, generated by SNP (rs4149601), and studied its expression and interactions with other isoforms by molecular biological, immunohistochemical, and electrophysiological methods. We found that isoform I may interact with other human isoforms in a dominant-negative fashion. Such interactions might abnormally increase sodium reabsorption. Taken together, our analyses suggest that the human Nedd4L gene, especially the evolutionarily new isoform I, is a candidate gene for hypertension.

The relation between B2 cells and commensal microbes during atherosclerosis remains largely unexplored. Here we show that under hyperlipidemic conditions intestinal microbiota resulted in recruitment and ectopic activation of B2 cells in perivascular adipose tissue, followed by an increase in circulating IgG, promoting disease development. In contrast, disruption of the intestinal microbiota by a broad-spectrum antibiotic cocktail (AVNM) led to the attenuation of atherosclerosis by suppressing B2 cells, despite the persistence of serum lipid abnormalities. Furthermore, pharmacological depletion of B2 cells with an anti-B2-cell surface CD23 antibody also attenuated commensal microbe-induced atherosclerosis. Moreover, expression analysis of TLR-signaling-related genes in the activated B2 cell subsets, assessed using the Toll-Like Receptor Signaling Pathway RT2 Profiler PCR Array, confirmed activation of the B2-cell autoantibody-production axis, which was associated with an increased capacity of B2 cells to bind to intestinal microbiota. Together, our findings reveal the critical role of commensal microbe-specific activation of B2 cells in the development of atherogenesis through lipid metabolism-independent mechanisms.

Objectives: We aimed to test our hypothesis that additional administration of traditional Japanese (Kampo) medicine, kakkonto (kakkon-to: KT) and shosaikotokakikyosekko (sho-saiko-to-ka-kikyo-sekko: SSKKS), is more effective in relieving symptoms and preventing the onset of severe infection in mild-to-moderate COVID-19 patients compared to those treated only with conventional treatment. Trial design: The study is designed as a multi-center, interventional, parallel-group, randomized (1:1 ratio), investigator-sponsored, two-arm study. Participants: Patients and inpatients will be recruited from 8 Japanese academic and non-academic hospitals. The inclusion and exclusion criteria are as follows: Inclusion criteria: Diagnosed as positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Clinical stages of mild-to-moderate COVID-19 Symptomatic ≥ 20 years of age Male or female Ability to communicate in Japanese Outpatients and inpatients Provided informed consent Exclusion criteria: Difficulty in providing informed consent due to dementia, psychosis, or psychiatric symptoms Allergic to Kampo or Western medicines used in this study Pregnant and lactating Unable to follow up Participating in another clinical trial or interventional study Hypokalemic or taking oral furosemide or steroids Determined unsuitable for this study by the physician Intervention and comparator: Patients in the control group will receive conventional treatment with antipyretics, painkillers, or antitussives for symptoms that occurred after they contracted the SARS-CoV-2 infection. Patients in the Kampo group will receive 2.5 g of KT (TJ-1@TSUMURA and Co.) and 2.5 g of SSKKS (TJ-109@TSUMURA and Co.) 3 times a day, orally, for 14 days in addition to the conventional treatment as mentioned above. Main outcomes: The number of days till at least one of the symptoms (fever, cough, sputum, malaise, shortness of breath) improves in the first 14 days of treatment. To assess the cough, sputum, malaise, and shortness of breath, a numeric rating scale will be used to define improvement in terms of a 2-point decrease in the number of days from the start of treatment for at least 2 days. Fever will be defined as an improvement when the temperature is less than 37 °C. Randomization: Patients are randomized (1:1 ratio) to each group using the minimization method, with balancing of the arms with severity of disease stage and patient age (< 65, 65 to < 75, or ≥ 75 years). Computer-generated random numbers will be used for the minimization method. Blinding (masking): Open-label with no blinding Numbers to be randomized (sample size): The main research hypothesis of this study is that the combination of Kampo medicine and conventional treatment will significantly improve the patients’ symptoms (fever, fatigue, cough, sputum, and shortness of breath) during the first 14 days of treatment as compared with conventional treatment alone. Concerning the analysis of the primary endpoint, the duration of time before improvement of at least one of the common cold-like symptoms (fever, malaise, cough, sputum, and shortness of breath) will be estimated using the Kaplan-Meier method, and the survival curves will be compared between groups using the log-rank test. Assuming this method of analysis and based on previous studies reporting the efficacy of Kampo medicine for COVID-19 and H1N1 influenza patients, the median survival time in the Kampo medicine group is estimated as 3 days; this time will be 1.5 times longer in the control group. Assuming a one-sided significance level of 5%, a power of 70%, and an allocation ratio of 1:1, the required sample size is calculated as 126 cases. To compensate for a loss in follow-up, we plan to include 150 cases in both groups (Kampo group = 75, control group = 75). Trial status: Protocol version 1.2 as of August 20, 2020 Recruitment start (expected): October 1, 2020 Recruitment finish (expected): October 31, 2023 Trial registration: Japan Registry of Clinical Trials (jRCT) jRCTs021200020. Registered on August 25, 2020 Full protocol: The full protocol is attached as an additional file and is accessible from the Trials website (Additional file 1). In the interest of expediting the dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

The interaction between atherosclerosis and commensal microbes through leaky gut syndrome (LGS), which is characterized by impaired intestinal permeability and the introduction of undesired pathogens into the body, has not been fully elucidated. Our aim was to investigate the potential role of a ClC-2 chloride channel activator, lubiprostone, which is reported to have beneficial effects on LGS, in the development of atherosclerosis in apolipoprotein E–deficient (ApoE-/-) mice. After a 15-week feeding period of a Western diet (WD), ApoE-/- mice were treated with a Western-type diet (WD) alone or WD with oral supplementation of lubiprostone for 10 weeks. This feeding protocol was followed by experimental evaluation of LGS and atherosclerotic lesions in the aorta. In mice with lubiprostone, in vivo translocation of orally administered 4-kDa FITC-dextran was significantly improved, and RNA expression of the epithelial tight junction proteins, Zo-1 and occludin, was significantly up-regulated in the ileum, compared to the WD alone group, suggesting a possible reversal of WD-induced intestinal barrier dysfunction. As a result, WD-induced exacerbation of atherosclerotic lesion formation was reduced by 69% in longitudinally opened aortas and 26% in aortic root regions. In addition, there was a significant decrease in circulating immunoglobulin level, followed by an attenuation of inflammatory responses in the perivascular adipose tissue, as evidenced by reduced expression of pro-inflammatory cytokines and chemokines. Lubiprostone attenuates atherosclerosis by ameliorating LGS-induced inflammation through the restoration of the intestinal barrier. These findings raise the possibility of targeting LGS for the treatment of atherosclerosis.