Membrane-associated guanylate kinase inverted 2 (MAGI-2) is a component of the slit diaphragm (SD) of glomerular podocytes. Here, we investigated the podocyte-specific function of MAGI-2 using newly generated podocyte-specific MAGI-2–knockout (MAGI-2–KO) mice. Compared with podocytes from wild-type mice, podocytes from MAGI-2–KO mice exhibited SD disruption, morphologic abnormalities of foot processes, and podocyte apoptosis leading to podocyte loss. These pathologic changes manifested as massive albuminuria by 8 weeks of age and glomerulosclerosis and significantly higher plasma creatinine levels at 12 weeks of age; all MAGI-2–KO mice died by 20 weeks of age. Loss of MAGI-2 in podocytes associated with decreased expression and nuclear translocation of dendrin, which is also a component of the SD complex. Dendrin translocates from the SD to the nucleus of injured podocytes, promoting apoptosis. Our coimmunoprecipitation and in vitro reconstitution studies showed that dendrin is phosphorylated by Fyn and dephosphorylated by PTP1B, and that Fyn-induced phosphorylation prevents Nedd4–2–mediated ubiquitination of dendrin. Under physiologic conditions in vivo, phosphorylated dendrin localized at the SDs; in the absence of MAGI-2, dephosphorylated dendrin accumulated in the nucleus. Furthermore, induction of experimental GN in rats led to the downregulation of MAGI-2 expression and the nuclear accumulation of dendrin in podocytes. In summary, MAGI-2 and Fyn protect dendrin from Nedd4–2–mediated ubiquitination and from nuclear translocation, thereby maintaining the physiologic homeostasis of podocytes, and the lack of MAGI-2 in podocytes results in FSGS.

Acetaminophen administration and the risk of acute kidney injury: a self-controlled case series study Shusuke Hiragi,1,2 Hiroyuki Yamada,1 Tatsuo Tsukamoto,1,3 Kazuki Yoshida,4,5 Naoya Kondo,1 Takeshi Matsubara,1 Motoko Yanagita,1 Hiroshi Tamura,2 Tomohiro Kuroda2 1Department of Nephrology, Graduate School of Medicine, Kyoto University, 2Division of Medical Informatics and Administration Planning, Kyoto University Hospital, Kyoto, 3Department of Nephrology and Dialysis, Kitano Hospital, Tazuke Kofukai Medical Research Institute, Osaka, Japan; 4Department of Epidemiology, 5Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA Background: Acetaminophen (APAP) is frequently used for analgesia and is considered safer than nonsteroidal anti-inflammatory drugs (NSAIDs) for the kidneys. However, there is little epidemiological evidence of the association between APAP and acute kidney injury (AKI).Objectives: To examine the association between APAP and AKI using the self-controlled case series (SCCS) method, which is a novel strategy to control between-person confounders by comparing the risk and reference periods in each patient.Methods: We performed SCCS in 1,871 patients (39.9% female) who were administered APAP and subsequently developed AKI, by reviewing electronically stored hospital information system data from May 2011 to July 2016. We used conditional Poisson regression to compare each patient’s risk and reference period. As a time-varying confounder, we adjusted the status of liver and kidney functions, systemic inflammation, and exposure to NSAIDs.Results: We identified 5,650 AKI events during the 260,549 person-day observation period. The unadjusted incidences during the reference and exposure periods were 2.01/100 and 3.12/100 person-days, respectively. The incidence rate ratio adjusted with SCCS was 1.03 (95% confidence interval [CI]: 0.95–1.12). When we restricted endpoints as stage 2 AKI- and stage 3 AKI-level creatinine elevations, the incidence rate ratios were 1.20 (95% CI 0.91–1.58) and 1.20 (95% CI 0.62–2.31), respectively, neither of which was statistically significant.Conclusion: Our findings added epidemiological information for the relationship between APAP administration and AKI development. The results indicated scarce association between APAP and AKI, presumably supporting the general physicians’ impression that APAP is safer for kidney. Keywords: acetaminophen, acute kidney injury, adverse drug event, self-controlled case series, hospital information system

Theoretically, atrial natriuretic peptide (ANP), especially low-dose ANP, is beneficial in acute kidney injury (AKI). In this study, we examined whether low-dose ANP is effective in preventing or treating AKI by conducting an updated systematic review for randomized controlled trials (RCTs). We searched the Excerpta Medica database (EMBASE), PubMed, and Cochrane CENTRAL databases for RCTs that compare the effects of low-dose ANP (≤ 50 ng/kg/min) with a placebo or conventional therapy in at-risk patients or patients with AKI. The primary outcome was the incidence of new AKI (in prevention RCTs), while the secondary outcomes were in-hospital mortality rate, renal replacement therapy (RRT) requirement, length of hospital and intensive care unit (ICU) stay, incidence of hypotension, and peak serum creatinine levels. The risk-of-bias was evaluated using the Cochrane Collaboration risk-of-bias tool. Trial sequential analysis (TSA) was used for each outcome of interest. A total of 18 RCTs (16 prevention and two treatment trials) fulfilled our inclusion criteria. In prevention RCTs, the incidence of new AKI was significantly low in the low-dose ANP group (relative risk [RR] = 0.51; 95% confidence interval [CI] = 0.36–0.72; P = 0.0001) compared to the control group. In addition, the low-dose ANP group showed a significantly reduced RRT requirement in both prevention (RR = 0.17; 95% CI = 0.04–0.64; P = 0.009) and treatment (RR = 0.43; 95% CI = 0.20–0.93; P = 0.03) RCTs. Among secondary outcomes, in some cases, low-dose ANP was associated with a reduction in ICU and in-hospital stay. The risk-of-bias assessment and TSA results indicated that the sample sizes and qualities of the RCTs were insufficient to conclude the efficacy of low-dose ANP. Low-dose ANP might be effective in preventing or treating AKI. However, the evidence accumulated so far is not strong enough to demonstrate ANP’s beneficial effects. The next step is to elucidate the effects of low-dose ANP by conducting multicenter, high-quality, large-sample RCTs. PROSPERO registry CRD42017068568 . Registered 20 June 2017.

Measuring real-time gene activity in the brains of freely moving animals presents a challenging issue in neuroscience research. Circadian gene expression in neurons of the suprachiasmatic nucleus (SCN), a small nucleus in the hypothalamus, is reflected in behavioral rhythmicity. Cellular oscillatory gene expression is generated by a transcription-translation feedback loop of clock genes including 2 oscillatory genes, Per1 and Per2. Here we have succeeded in real-time monitoring of Per1 and Per2 transcription separately by detecting the bioluminescence of luciferase (luc) reporters using a plastic optical fiber inserted into the SCN of freely moving rats. Per1-luc and Per2-luc rhythms peaked in the middle and late subjective day, respectively, which was confirmed by quantitative PCR-based measurements of SCN tissue samples. Studies of in vivo transcriptional states of clock genes in freely moving animals should improve our understanding of how clock gene expression is reflected in behavior.

Background: Coronavirus disease (COVID‐19), an infectious disease caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has spread worldwide since early 2020, and there are still no signs of resolution. The Japanese Clinical Practice Guidelines for the Management of Sepsis and Septic Shock (J‐SSCG) 2020 Special Committee created the Japanese Rapid/Living recommendations on drug management for COVID‐19 using the experience of creating the J‐SSCG.Methods: The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to determine the certainty of the evidence and strength of recommendations. The first edition of this guideline was released on September 9, 2020, and this is the revised edition (version 5.0; released on July 15, 2022). Clinical questions (CQs) were set for the following 10 drugs: favipiravir (CQ1), remdesivir (CQ2), corticosteroids (CQ4), tocilizumab (CQ5), anticoagulants (CQ7), baricitinib (CQ8), casirivimab/imdevimab (CQ9‐1), sotrovimab (CQ9‐2), molnupiravir (CQ10), and nirmatrelvir/ritonavir (CQ11).Recommendations: Favipiravir is not suggested for all patients with COVID‐19 (GRADE 2C). Remdesivir is suggested for patients with mild COVID‐19 who do not require oxygen, and patients with moderate COVID‐19 requiring supplemental oxygen/hospitalization (both GRADE 2B). Corticosteroids are recommended for moderate and severe COVID‐19 (GRADE 1B, 1A). However, their administration is not recommended for mild COVID‐19 (GRADE 1B). Tocilizumab is suggested for moderate and severe COVID‐19 (GRADE 2B, 2C). Anticoagulant administration is recommended for moderate and severe COVID‐19 (Good Practice Statement). Baricitinib is suggested for moderate and severe COVID‐19 (both GRADE 2C). Casirivimab/imdevimab and sotrovimab are recommended for mild COVID‐19 (both GRADE 2C). Molnupiravir and nirmatrelvir/ritonavir are recommended for mild COVID‐19 (both GRADE 2C). SARS‐CoV‐2 mutant strains emerge occasionally, and each time, the treatment policy at clinics is forced to change drastically. We ask health‐care professionals in the field to refer to the recommendations in these guidelines and use these to keep up to date with COVID‐19 epidemiological information.