RGMa collapses the neuronal actin barrier against disease-implicated protein and exacerbates ALS

Repulsive guidance molecule A (RGMa) was originally identified as a neuronal growth cone–collapsing factor. Previous reports have demonstrated the multifunctional roles of RGMa mediated by neogenin1. However, the pathogenic involvement of RGMa in amyotrophic lateral sclerosis (ALS) remains unclear. Here, we demonstrated that RGMa concentration was elevated in the cerebrospinal fluid of both patients with ALS and transgenic mice overexpressing the mutant human superoxide dismutase1 (mSOD1 mice). Treatment with humanized anti-RGMa monoclonal antibody ameliorated the clinical symptoms in mSOD1 mice. Histochemical analysis revealed that the anti-RGMa antibody significantly decreased mutant SOD1 protein accumulation in the motor neurons of mSOD1 mice via inhibition of actin depolymerization. In vitro analysis revealed that the anti-RGMa antibody inhibited the cellular uptake of the mutant SOD1 protein, presumably by reinforcing the neuronal actin barrier. Collectively, these data suggest that RGMa leads to the collapse of the neuronal actin barrier and promotes aberrant protein deposition, resulting in exacerbation of the ALS pathology.Shimizu Mikito, Shiraishi Naoyuki, Tada Satoru, et al. RGMa collapses the neuronal actin barrier against disease-implicated protein and exacerbates ALS. Science Advances 9, 686 (2023); https://doi.org/10.1126/sciadv.adg3193

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

Variant PRC1 Complex-Dependent H2A Ubiquitylation Drives PRC2 Recruitment and Polycomb Domain Formation

Chromatin modifying activities inherent to polycomb repressive complexes PRC1 and PRC2 play an essential role in gene regulation, cellular differentiation, and development. However, the mechanisms by which these complexes recognize their target sites and function together to form repressive chromatin domains remain poorly understood. Recruitment of PRC1 to target sites has been proposed to occur through a hierarchical process, dependent on prior nucleation of PRC2 and placement of H3K27me3. Here, using a de novo targeting assay in mouse embryonic stem cells we unexpectedly discover that PRC1-dependent H2AK119ub1 leads to recruitment of PRC2 and H3K27me3 to effectively initiate a polycomb domain. This activity is restricted to variant PRC1 complexes, and genetic ablation experiments reveal that targeting of the variant PCGF1/PRC1 complex by KDM2B to CpG islands is required for normal polycomb domain formation and mouse development. These observations provide a surprising PRC1-dependent logic for PRC2 occupancy at target sites in vivo.This study was funded by the Wellcome Trust (WT0834922 and WT081385), CRUK (C28585/A10839), NIHR, EMBO, Lister Institute of Preventative Medicine, RIKEN, MEXT, and JST CRES

Posterior reversible encephalopathy syndrome in children with kidney diseases

Posterior reversible encephalopathy syndrome (PRES) was originally used to describe a reversible, predominantly posterior leukoencephalopathy in patients who had renal insufficiency, hypertension, or who received immunosuppressive therapy. Since PRES is prevalent in children with kidney diseases, awareness and understanding of it is important for practicing pediatric nephrologists. A comprehensive approach to the diagnosis of PRES includes thorough determination of predisposing factors, clinical symptoms, and mandatory appropriate imaging. Unfortunately, the pathophysiology of PRES is still obscure and specificity of radiological examination has not yet been established. Two major predisposing factors, namely hypertension and calcineurin inhibitors, are well recognized. In addition, nephrotic syndrome is a common underlying condition for development of PRES. Frequent symptoms include altered consciousness (coma, stupor, lethargy, confusion), seizure, headache, and visual disturbance. Most of these symptoms usually develop abruptly and resolve within a few weeks after proper management. Cranial magnetic resonance (MR) imaging is the first-line modality of imaging studies for detecting PRES. Diffusion-weighted imaging with quantification of apparent diffusion coefficient (ADC) values by ADC mapping may provide more accurate and specific images in the future

Proteinuria during Follow-Up Period and Long-Term Renal Survival of Childhood IgA Nephropathy.

BACKGROUND:Proteinuria is the most important risk factor for IgA nephropathy progression. The purpose of this study is to evaluate the long-term outcome and risk factors for poor prognosis in childhood IgA nephropathy. METHODS:Patients who were diagnosed with IgA nephropathy between 1972 and 1992 at the Tokyo Metropolitan Kiyose Children's Hospital were included. We analyzed risk factors for progression to end-stage kidney disease (ESKD) and chronic renal insufficiency (CRI) using Kaplan-Meier method and multivariate analyses of Cox proportional hazard model. RESULTS:One hundred patients were included and the median observation period was 11.8 years. Twelve and 17 patients progressed to ESKD and CRI, respectively. The survival probabilities were 90.0% at 10 years and 79.8% at 20 years for ESKD, and 86.1% at 10 years and 72.3% at 20 years for CRI. Notably, patients with heavy proteinuria with hypoalbuminemia during follow-up period showed extremely poor prognosis. In this group, the survival rate at 10 years from ESKD and CRI was 40.6% and 20.8%, respectively. By multivariate analysis, proteinuria at diagnosis and proteinuria during follow-up period were risk factors for ESKD, whereas glomeruli showing mesangial proliferation ≥50% and proteinuria during follow-up period were risk factors for CRI. Patients without heavy proteinuria during follow-up period did not develop CRI and 63% of patients with mild proteinuria during follow-up period showed no proteinuria at the last observation. CONCLUSIONS:The degree of proteinuria during follow-up period is the strongest risk factor for ESKD and CRI

Noninvasive regional cerebral oxygen saturation for neurological prognostication of patients with out-of-hospital cardiac arrest: a prospective multicenter observational study.

[Aim]To investigate the association between regional brain oxygen saturation (rSO2) at hospital arrival and neurological outcomes at 90 days in patients with out-of-hospital cardiac arrest (OHCA). [Methods]The Japan-Prediction of neurological Outcomes in patients post cardiac arrest (J-POP) registry is a prospective, multicenter, cohort study to test whether rSO2 predicts neurological outcomes after OHCA. We measured rSO2 in OHCA patients immediately after hospital arrival using a near-infrared spectrometer placed on the forehead with non-blinded fashion. The primary endpoint was “neurological outcomes” at 90 days after OHCA. [Results]EMS providers are not permitted to terminate CPR in the field in Japan, and so most patients with OHCA who are treated by EMS personnel are transported to emergency hospitals. Among 1017 OHCA patients, 672 patients including 52 comatose patients with pulses detectable (8%) and 620 cardiac arrest patients (92%) at hospital arrival were enrolled prospectively and consecutively. Twenty-nine patients with good neurological outcome had a significantly higher value of rSO2 at hospital arrival than 643 patients with poor neurological outcome (mean [±SD] 55.6 ± 20.8% vs. 19.7 ± 11.0%, p 42% for predicting good neurological outcome, with sensitivity 0.79 (95% confidence interval [CI], 0.60?0.92), specificity 0.95 (95% CI, 0.93?0.96), positive predictive value, 0.41 (95% CI, 0.28?0.55), negative predictive value, 0.99 (95% CI, 0.98?1.00), and area under the curve 0.90 (95% CI, 0.88?0.92). [ConclusionThe rSO2 at hospital arrival can predict good neurological outcome at 90 days after OHCA

SAM Domain Polymerization Links Subnuclear Clustering of PRC1 to Gene Silencing

SummaryThe Polycomb-group (PcG) repressive complex-1 (PRC1) forms microscopically visible clusters in nuclei; however, the impact of this cluster formation on transcriptional regulation and the underlying mechanisms that regulate this process remain obscure. Here, we report that the sterile alpha motif (SAM) domain of a PRC1 core component Phc2 plays an essential role for PRC1 clustering through head-to-tail macromolecular polymerization, which is associated with stable target binding of PRC1/PRC2 and robust gene silencing activity. We propose a role for SAM domain polymerization in this repression by two distinct mechanisms: first, through capturing and/or retaining PRC1 at the PcG targets, and second, by strengthening the interactions between PRC1 and PRC2 to stabilize transcriptional repression. Our findings reveal a regulatory mechanism mediated by SAM domain polymerization for PcG-mediated repression of developmental loci that enables a robust yet reversible gene repression program during development