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The pandemic of novel coronavirus disease 2019 (COVID-19) is posing a threat to all populations, especially those with underlying diseases like cardiovascular diseases, diabetes, or kidney diseases (1,2). Patients with kidney failure who require hemodialysis (HD) or peritoneal dialysis (PD) to sustain their lives often have accompanying damaged immune systems and multiple coexisting disorders; hence, there is a need for special care for these patients under the COVID-19 outbreak. Our recent study demonstrated a high prevalence and poor prognosis of COVID-19 in patients on HD (3), but its effect on patients on PD is still unknown. In this multicentered study, all 818 patients on maintenance PD from four large medical institutions in Wuhan, China, from January 1, 2020 to April 12, 2020 were included. To minimize contact with potential infectious environments of patients on PD, routine visits to PD centers were stopped and substituted by regular online follow-up by health care workers, and medicines and dialysates were provided through a home delivery service by volunteers. Medical staff members were trained to triage patients so that they attended the outpatient PD department or the fever clinic, or they stayed at home, depending on different conditions. Initial nucleic acid testing (3) and antibody testing (4) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were performed in symptomatic patients on PD, and screening of the entire Wuhan population at the end of May 2020 identified no new patients among the PD population. Diagnosis of COVID-19 and disease severity were determined according to the COVID-19 guidelines of the National Health Commission of China (seventh edition). The sensitivity and specificity of the antibody assay were 87.3% and 100%, respectively. Clinical outcomes were monitored up to when the patient died or the date of April 22, 2020. Spent dialysates of infected patients were collected in designated containers, then disinfected with twice the volume of2.0 g/L hypochlorite solution for 2 hours, and drained into the sluice of the ward. Of 818 patients on PD, eight patients were diagnosed with COVID-19 during the studied period; the incidence rate of symptomatic SARS-CoV-2 infection was 2.44 per 1000 person-months. As shown in Table 1, the median age of patients with COVID-19 was similar to that of patients without COVID-19 on PD. Although no significant differences were detected, the median total Kt/V urea , ultrafiltration, and residual urine production H.

BackgroundThe responses of immunological factors to different subtypes of Kawasaki disease (KD) remain poorly understood.MethodsWe recruited 388 patients with KD, 160 patients with infectious febrile disease and 85 normal children who served as control subjects. Both the levels and percentages of T lymphocyte subsets, natural killer cells (NK cells) and B cells were analyzed via flow cytometry. The levels of serum IgG, IgM, IgA and C3, C4 were assessed via velocity scatter turbidimetry.ResultsThe most significant differences noted between the patients with infectious febrile disease and the normal children were the elevated levels of B cells, C3 and the ratio of CD4/CD8, and the decreased levels of CD8+ T cells and NK cells, as well as the moderate increase in the absolute value of the CD3+ cells. The decreased T cell levels and the elevated B cell levels were helpful in distinguishing typical KD from atypical KD; the elevated T cell levels, the elevated NK cell and B cell levels and the decreased B cell levels were helpful in predicting the effectiveness of IVIG; low C3 and C4 levels were linked with prodromal infections.ConclusionsLymphocytes subsets and complement markers may be useful in differentiating among the different subtypes of KD and in helping clinicians understand the pathophysiology of KD.

The family of cullin-RING E3 Ligases (CRLs) and the constitutive photomorphogenesis 9 (COP9) signalosome (CSN) form dynamic complexes that mediate ubiquitylation of 20% of the proteome, yet regulation of their assembly/disassembly remains poorly understood. Inositol polyphosphates are highly conserved signaling molecules implicated in diverse cellular processes. We now report that inositol hexakisphosphate (IP6) is a major physiologic determinant of the CRL-CSN interface, which includes a hitherto unidentified electrostatic interaction between the N-terminal acidic tail of CSN subunit 2 (CSN2) and a conserved basic canyon on cullins. IP6, with an EC 50 of 20 nM, acts as an intermolecular "glue," increasing cullin-CSN2 binding affinity by 30-fold, thereby promoting assembly of the inactive CRL-CSN complexes. The IP6 synthase, Ins(1,3,4,5,6)P5 2-kinase (IPPK/IP5K) binds to cullins. Depleting IP5K increases the percentage of neddylated, active Cul1 and Cul4A, and decreases levels of the Cul1/4A substrates p27 and p21. Besides dysregulating CRL-mediated cell proliferation and UV-induced apoptosis, IP5K depletion potentiates by 28-fold the cytotoxic effect of the neddylation inhibitor MLN4924. Thus, IP5K and IP6 are evolutionarily conserved components of the CRL-CSN system and are potential targets for cancer therapy in conjunction with MLN4924.ullin-RING ligases (CRLs), comprising cullins (Cul 1-3, 4A/B, 5, 7, 9), RING finger Roc1/2, and cullin-specific adaptors, form a prominent family of multiprotein E3 ubiquitin ligases that together mediate 20% of proteasomal degradation (1, 2), and are emerging therapeutic targets (3). CRLs require neddylation, the attachment of an ubiquitin-like NEDD8 molecule, for optimal function (4, 5) and are tightly regulated by the constitutive photomorphogenesis 9 (COP9) signalosome (CSN), an eightsubunit deneddylase complex conserved from plants to humans (6, 7). CSN biochemically inhibits but genetically activates . Elucidating the mechanism of binding and dynamic disassembly of the CRL-CSN complexes is therefore key to understand physiological functions of CRLs (6). Despite recent progress in solving the crystal structures of CRLs (1, 15), CSN (16), and the electron microscopy structure of the CSN-CRL1 complex (10), structural elements mediating CRL-CSN interactions remain elusive. Moreover, the molecular switches underlying CRL-CSN complex dynamics are unclear.The inositol polyphosphate pathway interacts with the CRL-CSN complexes via yet unspecified molecular mechanisms. Inositol polyphosphates (IP4, IP5, IP6) are highly conserved signaling molecules generated from the second messenger inositol 1,4,5-trisphosphate (IP3) by a family of inositol phosphate kinases (IPKs), including inositol 1,4,5-triphosphate 3-kinases, inositol 1,3,4-trisphosphate 5/6-kinase (ITPK1), inositol polyphosphate multikinase (IPMK), and inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IP5K) (17). Majerus and colleagues reported that CSN copurifies with ITPK1 (18), which catalyzes the first committed step in f...

The Cullin-RING ligases (CRLs) are the largest family of ubiquitin E3s activated by neddylation and regulated by the deneddylase COP9 signalosome (CSN). The inositol polyphosphate metabolites promote the formation of CRL–CSN complexes, but with unclear mechanism of action. Here, we provide structural and genetic evidence supporting inositol hexakisphosphate (IP6) as a general CSN cofactor recruiting CRLs. We determined the crystal structure of IP6 in complex with CSN subunit 2 (CSN2), based on which we identified the IP6-corresponding electron density in the cryoelectron microscopy map of a CRL4A–CSN complex. IP6 binds to a cognate pocket formed by conserved lysine residues from CSN2 and Rbx1/Roc1, thereby strengthening CRL–CSN interactions to dislodge the E2 CDC34/UBE2R from CRL and to promote CRL deneddylation. IP6 binding-deficient Csn2K70E/K70E knockin mice are embryonic lethal. The same mutation disabled Schizosaccharomyces pombe Csn2 from rescuing UV-hypersensitivity of csn2-null yeast. These data suggest that CRL transition from the E2-bound active state to the CSN-bound sequestered state is critically assisted by an interfacial IP6 small molecule, whose metabolism may be coupled to CRL–CSN complex dynamics.

Marek's disease virus (MDV) gene clones, RA2 and GA8, constructed in E. coli bacteriophage lambda-gt11 (gt11) were identified by a monoclonal antibody (MAb), H19.47, against a putative transformation-related viral antigen consisting of a complex of three phosphorylated polypeptides, pp41, pp38, and pp24. Both recombinants have a MDV-DNA insert of about 0.5 kb and are mapped to the region of BamHI-H or EcoRI-X fragments of the MDV genome by Southern blot hybridization. Immunoblot and immunoprecipitation with H19.47 identified a recombinant beta-galactosidase-MDV 140-kD fusion protein for RA2 and a 127-kD fusion protein for GA8. Immunoprecipitation of 35S-methionine-labeled, MDV-infected chicken embryo fibroblasts (CEF) with antisera against RA2 and GA8 fusion proteins recognized five polypeptides, of which three (p41, p38, and p24) are specified by H19.47 and the remaining two, p135 and p20, have not been previously identified. Immunoprecipitation of 32P-phosphate-labeled or 3H-glucosamine-labeled, GA-MDV-infected CEF with the antiserum against RA2 fusion protein identified a phosphorylated polypeptide of 38 kD and two glycoproteins of 60 and 49 kD, respectively. The antisera against recombinant fusion proteins thus revealed the existence of epitopes common to the phosphorylated polypeptides and other MDV-specific polypeptides. Sera from chickens or mice hyperimmunized with the purified fusion proteins reacted with serotype 1, MDV-infected CEF in the fluorescent antibody (FA) test to significant titers. These immune sera did not react with either serotype II or III, indicating the serotype specificity of the phosphorylated polypeptides.

Henoch-Schönlein purpura (HSP) is a multifactorial inflammatory disease whose pathogenesis remains unknown. Pyrin encoded by the MEFV gene (NM_000243; OMIM 608107) is an important active member of the inflammasome and has been shown to affect the expression of many of the genes involved in immune and inflammatory responses. The aim of our study was to elucidate the possible roles of MEFV genetic variants on the susceptibility to HSP and its clinical outcomes in 78 patients with HSP and 189 controls in China. A significant association was found between the E148Q polymorphism (G->C) and HSP susceptibility (odds ratio 2.76, 95% confidence interval 1.76-4.34, P=0.0001). The C allele of E148Q was associated with joint involvement (P=0.014) but not with HSP nephritis (P=0.1). The clinical score was higher in subjects with the CC genotype than in those with the CG or GG genotype (4.13+/-3.53 vs. 1.94+/-1.70, respectively; P=0.011). P369S was not associated with HSP or other phenotypes. M694V and M680I were absent in our patients. Our results suggest that MEFV E148Q could be a contributory genetic factor to HSP and HSP-related joint syndromes.