Zebrafish spop promotes ubiquitination and degradation of mavs to suppress antiviral response via the lysosomal pathway.

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) signaling pathways are required to be tightly controlled to initiate host innate immune responses. Fish mitochondrial antiviral signaling (mavs) is a key determinant in the RLR pathway, and its ubiquitination is associated with mavs activation. Here, we identified the zebrafish E3 ubiquitin ligase Speckle-type BTB-POZ protein (spop) negatively regulates mavs-mediated the type I interferon (IFN) responses. Consistently, overexpression of zebrafish spop repressed the activity of IFN promoter and reduced host ifn transcription, whereas knockdown spop by small interfering RNA (siRNA) transfection had the opposite effects. Accordingly, overexpression of spop dampened the cellular antiviral responses triggered by spring viremia of carp virus (SVCV). A functional domain assay revealed that the N-terminal substrate-binding MATH domain regions of spop were necessary for IFN suppression. Further assays indicated that spop interacts with mavs through the C-terminal transmembrane (TM) domain of mavs. Moreover, zebrafish spop selectively promotes K48-linked polyubiquitination and degradation of mavs through the lysosomal pathway to suppress IFN expression. Our findings unearth a post-translational mechanism by which mavs is regulated and reveal a role for spop in inhibiting antiviral innate responses.

The effect of glucocorticoids on mortality in severe COVID-19 patients: Evidence from 13 studies involving 6612 cases.

BACKGROUND: Since the start of the coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need for effective therapies for patients with COVID-19. In this study, we aimed to assess the therapeutic efficacy of glucocorticoids in severe COVID-19. METHODS: A systematic literature search was performed across PubMed, Web of Science, EMBASE, and the Cochrane Library (up to June 26, 2021). The literature investigated the outcomes of interest were mortality and invasive mechanical ventilation. RESULTS: The search identified 13 studies with 6612 confirmed severe COVID-19 patients. Our meta-analysis found that using glucocorticoids could significantly decrease COVID-19 mortality (hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.45-0.79, P < .001), relative to non-use of glucocorticoids. Meanwhile, using glucocorticoids also could significantly decrease the risk of progression to invasive mechanical ventilation for severe COVID-19 patients (HR = 0.69, 95% CI 0.58-0.83, P < .001). Compared with using dexamethasone (HR = 0.68, 95% CI 0.50-0.92, P = .012), methylprednisolone use had a better therapeutic effect for reducing the mortality of patients (HR = 0.35, 95% CI 0.19-0.64, P = .001). CONCLUSION: The result of this meta-analysis showed that using glucocorticoids could reduce mortality and risk of progression to invasive mechanical ventilation in severe COVID-19 patients.

Single Chemosensor for Double Analytes: Spectrophotometric Sensing of Cu(2+) and Fluorogenic Sensing of Al(3+) Under Aqueous Conditions.

(E)-N-((8-Hydroxy-1,2,3,5,6,7-hexahydropyrido-[3,2,1-ij]-quinolin-9-yl)methylene)-4-tert-butyl -benzhydrazide has been developed as a single, dual-functional chemosensor. The chemosensor showed a good selectivity and sensitivity toward to Al(3+) and Cu(2+) at a low detection limit, respectively. Theoretical calculations have also been carried out to understand the configuration of the complexes.

[Protective efficacy of co-immunization with Sj26 DNA and recombinant protein vaccine against Schistosoma japonicum in mice].

OBJECTIVE: To study the protective efficacy of co-immunization with Schistosoma japonicum glutathione S-transferase (Sj26) DNA and recombinant Sj26 protein (rSj26 GST) vaccine against Schistosoma japonicum in BALB/c mice. METHODS: The Sj26 gene was cloned into eukaryotic expression vector pEGFP-N3 with enhanced green fluorescence protein. The recombinant plasmid pEGFP-Sj26 was transfected into baby hamster kidney (BHK) cells, fluorescent microscope and Western blotting were employed to identify the expressed products. Each mouse in co-immunization group was primed with plasmid pEGFP-Sj26, boosted 2 weeks later and immunized with rSj26 GST 4 weeks later. While each mouse in pEGFP-Sj26 group and rSj26 GST group was primed and boosted with pEGFP-Sj26 or rSj26 GST independently. Two weeks after last immunization, each mouse was challenged with 40 +/- 1 cercariae of S. japonicum Chinese strain. At the 45th day post-infection, mice were sacrificed and the worms were perfused from portal vein and the number of worms and eggs in liver tissue were counted. RESULTS: In BHK cells transfected with the recombinant plasmid pEGFP-Sj26, the expression of Sj26-EGFP fusion protein was confirmed by fluorescent microcopy and Western blotting. The worm reduction rate in co-immunized group was 50.8%, significantly higher than that in pEGFP-Sj26 group (28.0%, P < 0.01) and rSj26 GST group (25.5%, P < 0.01). Liver egg reduction rate in co-immunized group, pEGFP-Sj26 group and rSj26 GST group were 32.7%, 20.6% and 33.0% respectively. The number of eggs per female in liver of co-immunized mice and rSj26 GST group were significantly higher than that in control group (P < 0.01). CONCLUSION: Compared to the immunization with pEGFP-Sj26 or rSj26 GST alone, the co-immunization with pEGFP-Sj26 and rSj26 GST can enhance protective efficacy in BALB/c mice.