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The accessory gene regulatory (Agr) system is required for virulence factor gene expression and pathogenesis of Staphylococcus aureus. The Agr system is activated in response to the accumulation of a cyclic autoinducing peptide (AIP), which is matured and secreted by the bacterium. The precursor of AIP, AgrD, consists of the AIP flanked by an N-terminal [Formula: see text]-helical Leader and a charged C-terminal tail. AgrD is matured to AIP by the action of two proteases, AgrB and MroQ. AgrB cleaves the C-terminal tail and promotes the formation of a thiolactone ring, whereas MroQ cleaves the N-terminal Leader in a manner that depends on the four-amino acid linker immediately following a conserved IG helix breaker motif. However, the attributes of AgrD that dictate the sequence of events in peptide maturation are not fully defined. Here, we used engineered AgrD peptide intermediates to ascertain the sufficiency of MroQ for N-terminal peptide cleavage, peptide export, and generation of mature AIP. We found that MroQ promotes the removal of the N-terminal Leader peptide from both linear and cyclic peptide intermediates, while peptide cyclization remained essential for signaling. The expression of the Leader peptide in isolation was sufficient for MroQ-dependent cleavage proximal to the four-amino-acid linker. In addition, active site mutations within AgrB destabilized full-length AgrD and thiolactone-containing intermediates and prevented the release of the Leader peptide. Altogether, our data support a tandem peptide maturation event involving both MroQ and AgrB that appears to couple protease activity and export of bioactive AIP.IMPORTANCEThe accessory gene regulatory (Agr) system is important for S. aureus pathogenesis. Activation of the Agr system requires recognition of a cyclic peptide pheromone, which must be fully matured to exert its biological activity. The complete events in cyclic peptide maturation and export from the bacterial cell remain to be fully defined. We and others recently discovered that the membrane peptidase MroQ is required for pheromone maturation. This study builds off the identification of MroQ and considers the attributes of the pheromone pro-peptide that are required for MroQ-mediated processing as well as uncovers features important for peptide stability and export. Overall, the findings in this study have implications for understanding bacterial pheromone maturation and virulence.
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Myelofibrosis is a rare and often fatal hematological neoplasm, and the treatment of myelofibrosis-associated anemia remains suboptimal, with no improved therapies. Luspatercept was shown to display some efficacy in a phase 2 clinical trial for Myelofibrosis with anemia, yet relevant research are limited. Threrfore, data from patients diagnosed with refractory anemic primary or post-essential thrombocythemia/polycythemia vera myelofibrosis, who were treated with luspatercept for at least 9 weeks, were retrospectively collected. Eighteen patients with myelofibrosis treated with luspatercept were enrolled. Median age was 68 years (range, 44-80 years), and 27.8% were males. Ten (55.6%) were transfusion-dependent. Ten (55.6%) were Dynamic International Prognostic Scoring System intermediate-1, and eight (44.4%) were intermediate-2. The median follow-up was 7 (4-16) months. Erythroid response occurred in eight patients (44.4%) at week 12, four patients (30.8%) at week 24, and nine (50%) at the end of follow-up. Patients who were transfusion-dependent and not transfusion-dependent had similar HI-E responses, at different time points (P > 0.05). Patients had a significantly higher hemoglobin level at 12 weeks, 24 weeks, and at the end of follow-up, than at baseline (P = 0.001, P = 0.021, and P = 0.005, respectively). Treatment-related adverse events occurred in five (16.7%) patients, with no serious adverse events. Two (11.1%) patients relapsed at weeks 15 and 31. One patient progressed to acute myeloid leukemia. No patients had died by the end of follow-up. Luspatercept induced a good response in patients with anemic myelofibrosis, with a low relapse rate and good tolerance.
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BACKGROUND: The lesser grain borer (Rhyzopertha dominica), a worldwide primary pest of stored grain, causes serious economic losses and threatens stored food safety. R. dominica can respond to changes in temperature, especially the adaptability to heat. In this study, transcriptome analysis of R. dominica exposed to different temperatures was performed to elucidate differences in gene expression and the underling molecular mechanism. RESULTS: Isoform-sequencing generated 17,721,200 raw reads and yielded 20,416 full-length transcripts. A total of 18,880 (92.48%) transcripts were annotated. We extracted RNA from R. dominica reared at 5 °C (cold stress), 15 °C (cold stress), 27 °C (ambient temperature) and 40 °C (heat stress) for RNA-seq. Compared to those of control insects reared at 27 °C, 119, 342, and 875 differentially expressed genes (DEGs) were identified at 5 °C, 15 °C, and 40 °C, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that pathways associated with "fatty acid metabolism", "fatty acid biosynthesis", "AMPK signaling pathway", "neuroactive ligand receptor interaction", and "longevity regulating pathway-multiple species" were significantly enriched. The functional annotation revealed that the genes encoding heat shock proteins (HSPs), fatty acid synthase (FAS), phospholipases (PLA), trehalose transporter (TPST), trehalose 6-phosphate synthase (TPS), and vitellogenin (Vg) were most likely involved in temperature regulation, which was also validated by RT-qPCR. Seven candidate genes (rdhsp1, rdfas1, rdpla1, rdtpst1, rdtps1, rdvg1, and rdP450) were silenced in the RNA interference (RNAi) assay. RNAi of each candidate gene suggested that inhibiting rdtps1 expression significantly decreased the trehalose level and survival rate of R. dominica at 40 °C. CONCLUSIONS: These results indicated that trehalose contributes to the high temperature resistance of R. dominica. Our study elucidates the molecular mechanisms underlying heat tolerance and provides a potential target for the pest management in R. dominica.
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Aclimatação , Besouros , Trealose , Aclimatação/genética , Ácidos Graxos , FosfatosRESUMO
Dysfunctional mutations in SAMHD1 cause Aicardi-Goutières Syndrome, an autoinflammatory encephalopathy with elevated interferon-α levels in the cerebrospinal fluid. Whether loss of function mutations in SAMHD1 trigger the expression of other cytokines apart from type I interferons in Aicardi-Goutières Syndrome is largely unclear. This study aimed to explore whether SAMHD1 dysfunction regulated the expression of IL-34, a key cytokine controlling the development and maintenance of microglia, in SH-SY5Y neural cells. We found that downregulation of SAMHD1 in SH-SY5Y cells resulted in the upregulation of IL-34 expression. The protein and mRNA levels of NF-κB p65, the transactivating subunit of a transcription factor NF-κB, were also upregulated in SAMHD1-knockdown SH-SY5Y cells. It was further found SAMHD1 knockdown in SH-SY5Y cells induced an upregulation of IL-34 expression through the canonical NF-κB-dependent pathway in which NF-κB p65, IKKα/ß and the NF-κB inhibitor IκBα were phosphorylated. Moreover, knockdown of SAMHD1 in SH-SY5Y cells led to the translocation of NF-κB p65 into the nucleus and promoted NF-κB transcriptional activity. In conclusion, we found SAMHD1 dysfunction induced IL-34 expression via NF-κB p65 in neuronal SH-SY5Y cells. This finding could lay the foundation for exploring the role of IL-34-targeting microglia in the pathogenesis of Aicardi-Goutières Syndrome.
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Doenças Autoimunes do Sistema Nervoso , Malformações do Sistema Nervoso , Neuroblastoma , Humanos , NF-kappa B/metabolismo , Proteína 1 com Domínio SAM e Domínio HD , Neuroblastoma/genética , Inibidor de NF-kappaB alfa , Citocinas , InterleucinasRESUMO
5,10-methenyltetrahydrofolate synthetase (MTHFS) deficiency is a folate metabolism disorder known as a rare autosomal recessive neurodevelopmental disorder (MIM: #618367). With central nervous system involvements, it is mainly characterized by developmental delay, epilepsy, microcephaly, hypertonia, and cranial nerves involvement. Here, we report three new cases with MTHFS deficiency from two non-consanguineous Chinese families. All patients showed white matter dysplasia and global developmental delay, of which only patient 1 and 2 manifested tonic-clonic seizures. Moreover, patient 2 had severe eczema and patient 3 had recurrent diarrhea. Both phenotypic features are firstly found in MTHFS deficiency. Trio whole-exome sequencing and sanger sequencing were used to identify four novel variants, p.Y169Tfs*17, p.S53F, c.117+1delG, and p.E61G in the MTHFS gene. The identification of four novel pathogenic variants and varied clinical features in three affected patients expands the genotype and phenotype spectrum of MTHFS deficiency. We also reviewed all cases of MTHFS deficiency that had previously been reported. The experience of diagnosis and treatment from these cases provides us a more comprehensive understanding of this rare disease.
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BACKGROUND: Joubert syndrome (JS) is a group of rare ciliopathies, mainly characterized by cerebellar dysplasia representing the "molar tooth sign (MTS)" on neuroimaging, hypotonia, and developmental delay. Having a complicated genotype-phenotype correlation due to its rich genetic heterogeneity, JS is usually combined with other organic defects affecting the retina, kidney, and liver. This report aimed to present new cases and novel variants of JS. CASE PRESENTATION: Five unrelated patients who were diagnosed with JS, with or without typical clinical characteristics, received integrated examinations, including whole-exome sequencing (WES) and Sanger sequencing. We identified nine pathogenic variants in the TCTN2, CPLANE1, INPP5E, NPHP1, and CC2D2A genes. CONCLUSION: Four novel pathogenic mutations in the TCTN2, CPLANE1, and INPP5E genes were reported. The findings broadened the genotypic spectrum of JS and contributed to a better understanding of genotype-phenotype correlation.
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Anormalidades Múltiplas , Anormalidades do Olho , Doenças Renais Císticas , Humanos , Anormalidades Múltiplas/genética , Cerebelo/diagnóstico por imagem , População do Leste Asiático , Anormalidades do Olho/genética , Doenças Renais Císticas/genética , Proteínas de Membrana , Monoéster Fosfórico Hidrolases/genética , Retina , MutaçãoRESUMO
Carbon-supported Pt is currently used as catalyst for oxygen reduction reaction (ORR) in fuel cells but is handicapped by carbon corrosion at high potential. Herein, a stable PtNi/SnO2 interface structure has been designed and achieved by a two-step solvothermal method. The robust and conductive Sb-doped SnO2 supports provide sufficient surfaces to confine PtNi alloy. Moreover, PtNi/Sb0.11 SnO2 presents a more strongly coupled Pt-SnO2 interface with lattice overlap of Pt (111) and SnO2 (110), together with enhanced electron transfer from SnO2 to Pt. Therefore, PtNi/Sb0.11 SnO2 exhibits a high catalytic activity for ORR with a half-wave potential of 0.860â V versus reversible hydrogen electrode (RHE) and a mass activity of 166.2â mA mgPt -1 @0.9â V in 0.1â M HClO4 electrolyte. Importantly, accelerated degradation testing (ADT) further identify the inhibition of support corrosion and agglomeration of Pt-based active nanoparticles in PtNi/Sb0.11 SnO2 . This work highlights the significant importance of modulating metal-support interactions for improving the catalytic activity and durability of electrocatalysts.
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Anemia Aplástica , COVID-19 , Humanos , SARS-CoV-2 , Anemia Aplástica/terapia , Estudos Prospectivos , COVID-19/complicações , Doença Crônica , RecidivaRESUMO
Objective: To investigate the effectiveness of hip continuous passive motion (hCPM) on hip development at skeletal maturity and gross motor function for spastic cerebral palsy children with hip dysplasia. Methods: Prospective case-control research of hCPM with goal-directed training versus merely goal-directed training. On the basis of goal-directed training, the hCPM group used the hip joint CPM instrument (the external fixator was connected to the power device to make the hip joint carry out continuous passive movement) for 40-60â min, twice a day, and five times a week, and received continuous training for 8 weeks simultaneously. The control group received only goal-directed training for 8 weeks. Functional outcomes pertaining to the affected hip joints were assessed via gross motor function measure (GMFM), migration percentage (MP), acetabular index (AI), and Harris hip functional score (HHS) at the time of enrollment and the end of the intervention. Results: The case-control research included 65 participants (mean age = 46.20â months, SD = 17.09â months; Gross Motor Function Grading System level: III = 41, IV = 24) who were randomly selected to either the hCPM (n = 45) or the control group (n = 20). No differences were found in baseline (acquisition phase) GMFM, MP, AI, or HHS (t = -1.720, P = 0.090; t* = 1.836, P* = 0.071; t# = -1.517, P# = 0.139; t* = -1.310, P* = 0.195; t# = -1.084, P# = 0.097; t = -1.041, P = 0.301). At the 8-week follow-up, GMFM, MP, AI, and HHS significantly improved over baseline in the hCPM group (hCPM group: t = 18.59, 20.172*, 40.291#, 16.820*, 32.900#, 28.081; P < 0.001). Between-group differences at 8-week follow-up times points favored the hCPM group for GMFM (t = -2.637, P = 0.011), MP (t* = 2.615, P* = 0.014; t# = 3.000, P# = 0.006), AI (t* = 2.055, P* = 0.044; t# = 2.223, P# = 0.030), HHS (t = -4.685, P < 0.001) (*: left side; #: right side). Conclusion: Spastic cerebral palsy children with hip dysplasia achieved meaningful functional improvement after 8 weeks of goal-directed training with hCPM therapy.
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All vanadium flow batteries (VFBs) are considered one of the most promising large-scale energy storage technology, but restricts by the high manufacturing cost of V3.5+ electrolytes using the current electrolysis method. Here, a bifunctional liquid fuel cell is designed and proposed to produce V3.5+ electrolytes and generate power energy by using formic acid as fuels and V4+ as oxidants. Compared with the traditional electrolysis method, this method not only does not consume additional electric energy, but also can output electric energy. Therefore, the process cost of producing V3.5+ electrolytes is reduced by 16.3%. This fuel cell has a maximum power of 0.276 mW cm-2 at an operating current of 1.75 mA cm-2 . Ultraviolet-visible spectrum and potentiometric titration identify the oxidation state of prepared vanadium electrolytes is 3.48 ± 0.06, close to the ideal 3.5. VFBs with prepared V3.5+ electrolytes deliver similar energy conversion efficiency and superior capacity retention to that with commercial V3.5+ electrolytes. This work proposes a simple and practical strategy to prepare V3.5+ electrolytes.
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Fontes de Energia Elétrica , Vanádio , Eletroquímica , Eletrólitos , OxirreduçãoRESUMO
Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy with dismal prognosis. Identification of better biomarkers remained a priority to improve established stratification and guide therapeutic decisions. Therefore, we extracted the RNA sequence data and clinical characteristics of AML from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression database (GTEx) to identify the key factors for prognosis. We found UNC93B1 was highly expressed in AML patients and significantly linked to poor clinical features (p < 0.05). We further validated the high expression of UNC93B1 in another independent AML cohort from GEO datasets (p < 0.001) and performed quantitative PCR of patient samples to confirm the overexpression of UNC93B1 in AML (p < 0.005). Moreover, we discovered high level of UNC93B1 was an independent prognostic factor for poorer outcome both in univariate analysis and multivariate regression (p < 0.001). Then we built a nomogram model based on UNC93B1 expression, age, FAB subtype and cytogenetic risk, the concordance index of which for predicting overall survival was 0.729 (p < 0.001). Time-dependent ROC analysis for predicting survival outcome at different time points by UNC93B1 showed the cumulative 2-year survival rate was 43.7%, and 5-year survival rate was 21.9%. The differentially expressed genes (DEGs) between two groups divided by UNC93B1 expression level were enriched in innate immune signaling and metabolic process pathway. Protein-protein interaction (PPI) network indicated four hub genes (S100A9, CCR1, MRC1 and CD1C) interacted with UNC93B1, three of which were also significantly linked to inferior outcome. Furthermore, we discovered high UNC93B1 tended to be infiltrated by innate immune cells, including Macrophages, Dendritic cells, Neutrophils, Eosinophils, and NK CD56dim cells. We also found UNC93B1 had a significantly positive correlation with CD14, CD68 and almost all Toll-like receptors. Finally, we revealed negatively correlated expression of UNC93B1 and BCL2 in AML and conjectured that high-UNC93B1 monocytic AML is more resistant to venetoclax. And we found high MCL-1 expression compensated for BCL-2 loss, thus, we proposed MCL-1 inhibitor might overcome the resistance of venetoclax in AML. Altogether, our findings demonstrated the utility of UNC93B1 as a powerful poor prognostic predictor and alternative therapeutic target.
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Aplastic anemia (AA) is an auto-activated T cell-mediated bone marrow failure. Cyclosporine is often used to treat non-severe AA, which demonstrates a more heterogeneous condition than severe AA. The response rate to cyclosporine is only around 50% in non-severe AA. To better predict response to cyclosporine and pinpoint who is the appropriate candidate for cyclosporine, we performed phenotypic and functional T cell immune signature at single cell level by mass cytometry from 30 patients with non-severe AA. Unexpectedly, non-significant differences of T cell subsets were observed between AA and healthy control or cyclosporine-responder and non-responders. Interestingly, when screening the expression of co-inhibitory molecules, T cell trafficking mediators, and cytokines, we found an increase of cytotoxic T lymphocyte antigen 4 (CTLA-4) on T cells in response to cyclosporine and a lower level of CTLA-4 on CD8+ T cells was correlated to hematologic response. Moreover, a decreased expression of sphingosine-1-phosphate receptor 1 (S1P1) on naive T cells and a lower level of interleukin-9 (IL-9) on T helpers also predicted a better response to cyclosporine, respectively. Therefore, the T cell immune signature, especially in CTAL-4, S1P1, and IL-9, has a predictive value for response to cyclosporine. Collectively, our study implies that immune signature analysis of T cell by mass cytometry is a useful tool to make a strategic decision on cyclosporine treatment of AA.
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Anemia Aplástica , Linfócitos T , Humanos , Anemia Aplástica/diagnóstico , Linfócitos T CD8-Positivos/metabolismo , Antígeno CTLA-4/metabolismo , Ciclosporina , Interleucina-9/metabolismo , Linfócitos T/imunologiaRESUMO
Traditional antibiotics target essential cellular components or metabolic pathways conserved in both pathogenic and nonpathogenic bacteria. Unfortunately, long-term antibiotic use often leads to antibiotic resistance and disruption of the overall microbiota. In this work, we identified a phenylamino acetamide compound, named 187R, that strongly inhibited the expression of the type III secretion system (T3SS) encoding genes and the secretion of the T3SS effector proteins in Pseudomonas aeruginosa. T3SS is an important virulence factor, as T3SS-deficient strains of P. aeruginosa are greatly attenuated in virulence. We further showed that 187R had no effect on bacterial growth, implying a reduced selective pressure for the development of resistance. 187R-mediated repression of T3SS was dependent on ExsA, the master regulator of T3SS in P. aeruginosa. The impact of 187R on the host-associated microbial community was also tested using the Arabidopsis thaliana phyllosphere as a model. Both culture-independent (Illumina sequencing) and culture-dependent (Biolog) methods showed that the application of 187R had little impact on the composition and function of microbial community compared to the antibiotic streptomycin. Together, these results suggested that compounds that target virulence factors could serve as an alternative strategy for disease management caused by bacterial pathogens. IMPORTANCE New antimicrobial therapies are urgently needed, since antibiotic resistance in human pathogens has become one of the world's most urgent public health problems. Antivirulence therapy has been considered a promising alternative for the management of infectious diseases, as antivirulence compounds target only the virulence factors instead of the growth of bacteria, and they are therefore unlikely to affect commensal microorganisms. However, the impacts of antivirulence compounds on the host microbiota are not well understood. We report a potent synthetic inhibitor of the P. aeruginosa T3SS, 187R, and its effect on the host microbiota of Arabidopsis. Both culture-independent (Illumina sequencing) and culture-dependent (Biolog) methods showed that the impacts of the antivirulence compound on the composition and function of host microbiota were limited. These results suggest that antivirulence compounds can be a potential alternative method to antibiotics.
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Proteínas de Bactérias , Pseudomonas aeruginosa , Sistemas de Secreção Tipo III , Fatores de Virulência , Humanos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Virulência/genética , Virulência/fisiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismoRESUMO
BACKGROUND: Systemic inflammatory and autoimmune manifestations (SIAMs) are frequently reported in Myelodysplastic syndromes (MDS). Studies focused on the impact of SIMAs on survival outcomes of MDS remains controversial. We performed this systematic review and meta-analysis to determine the association of SIAMs with overall survival, median survival, rate of acute myeloid leukemia transformation and mortality of MDS. MATERIALS AND METHODS: An electronic search was conducted in 4 databases without any language restrictions, including PubMed, EMBASE, Medicine and Cochrane library up to April 30, 2021. RESULTS: The 18 studies included a total of 4603 MDS patients, of which 1175 (25.5%) patients had SIAMs. MDS patients with SIAMs had a statistically shorter overall survival compared with patient without SIAMs (Hazard ratio, 2.43; 95% confidence interval [CI], 1.34-4.41; Pâ <â .01). Our results were most compatible with no effect of SIAMs on median survival, rate of acute myeloid leukemia transformation and mortality (Median survival ratio, 1.16; 95% CI, 0.91-1.47; Odds ratio, 0.96; 95% CI, 0.63-1.45 and 1.2; 95% CI, 0.84-1.7, respectively). CONCLUSION: In this systematic review and meta-analysis, SIAMs appeared to have an adverse effect on overall survival of MDS patients. This finding suggested that SIAMs may be a potential independent prognostic factor for MDS.
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Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Humanos , Síndromes Mielodisplásicas/complicações , Leucemia Mieloide Aguda/complicaçõesRESUMO
Acute myeloid leukaemia (AML) is a heterogeneous disease associated with poor outcomes. To identify AML-specific genes with prognostic value, we analysed transcriptome and clinical information from The Cancer Genome Atlas (TCGA) database, Gene Expression Omnibus (GEO) datasets, and Genotype-Tissue Expression (GTEx) project. The metabolism-related gene, SLC25A21 was found to be significantly downregulated in AML, and was associated with high white blood cell (WBC) counts, high pretrial blood (PB) and bone marrow (BM) blast abundance, FLT3 mutation, NPM1 mutation, and death events (all p value <0.05). We validated the expression of SLC25A21 in our clinical cohort, and found that SLC25A21 was downregulated in AML. Moreover, we identified low expression of SLC25A21 as an independent prognostic factor by univariate Cox regression (hazard ratio [HR]: 0.550; 95% Confidence interval [CI]: 0.358-0.845; p value = 0.006) and multivariate Cox regression analysis (HR: 0.341; 95% CI: 0.209-0.557; p value <0.05). A survival prediction nomogram was established with a C-index of 0.735, which indicated reliable prognostic prediction. Subsequently, based on the median SLC25A21 expression level, patients in the TCGA-LAML cohort were divided into low- and high-expression groups. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs highlighted growth factor binding, extracellular structure organization, cytokineâcytokine receptor interaction, etc. The results of gene set enrichment analysis (GSEA) indicated that the epithelial-mesenchymal transition, KRAS signalling, oxidative phosphorylation, and reactive oxygen species pathways were enriched. Through gene coexpression and proteinâprotein interaction (PPI) network analysis, we identified two hub genes, EGFR and COL1A2, which were linked to worse clinical outcomes. Furthermore, we found that lower SLC25A21 expression was closely associated with a significant reduction in the levels of infiltrating immune cells, which might be associated with immune escape of AML cells. A similar trend was observed for the expression of checkpoint genes (CTLA4, LAG3, TIGIT, and HAVCR2). Finally, drug sensitivity testing suggested that the low-expression SLC25A21 group is sensitive to doxorubicin, mitomycin C, linifanib but resistant to JQ1, belinostat, and dasatinib. Hence, our study demonstrated that a low expression level of SLC25A21 predicts an unfavourable prognosis in patients with AML.
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Gram-positive bacteria produce small autoinducing peptides (AIPs), which act to regulate expression of genes that promote adaptive traits, including virulence. The Gram-positive pathogen Staphylococcus aureus generates a cyclic AIP that controls expression of virulence factors via the accessory gene regulatory (Agr) system. S. aureus strains belong to one of four Agr groups (Agr-I, -II, -III, and -IV); each group harbors allelic variants of AgrD, the precursor of AIP. In a prior screen for S. aureus virulence factors, we identified MroQ, a putative peptidase. A ΔmroQ mutant closely resembled a Δagr mutant and had significant defects in AIP production in an Agr-I strain. Here, we show that expression of AgrD-I in a ΔmroQ mutant leads to accumulation of an AIP processing intermediate at the membrane that coincides with a loss of secreted mature AIP, indicating that MroQ promotes maturation of AgrD-I. MroQ is conserved in all Agr sequence variants, suggesting either identical function among all Agr types or activity specific to Agr-I strains. Our data indicate that MroQ is required for AIP maturation and activity in Agr-I, -II, and -IV strains irrespective of background. However, MroQ is not required for Agr-III activity despite an identifiable role in peptide maturation. Isogenic Δagr and Δagr ΔmroQ strains complemented with Agr-I to -IV validated the critical role of MroQ in the generation of active AIP-I, -II, and -IV but not AIP-III. These findings were reinforced by skin infection studies with mice. Our data substantiate the prevailing model that MroQ is a mediator of cyclic peptide maturation.
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Peptídeos Cíclicos , Staphylococcus aureus , Camundongos , Animais , Fatores de Virulência/metabolismo , Peptídeo Hidrolases/metabolismo , Peptídeos/metabolismoRESUMO
Cerebral palsy (CP) is a group of permanent, but not unchanging, disorders of movement and/or posture and motor function. Since the major brain injury associated with CP is white matter injury (WMI), especially, in preterm infants, we established a "multi-hit" rat model to mimic human WMI in symptomatology and at a histological level. In our WMI model, pups suffering from limb paresis, incoordination, and direction difficulties fit the performance of CP. Histologically, they present with fewer neural cells, inordinate fibers, and more inflammatory cell infiltration, compared to the control group. From the electron microscopy results, we spotted neuronal apoptosis, glial activation, and myelination delay. Besides, the abundant appearance of IBA1-labeled microglia also implied that microglia play a role during neuronal cell injury. After activation, microglia shift between the pro-inflammatory M1 type and the anti-inflammatory M2 type. The results showed that LPS/infection stimulated IBA1 + (marked activated microglia) expression, downregulated CD11c + (marked M1 phenotype), and upregulated Arg 1 + (marked M2 phenotype) protein expression. It indicated an M1 to M2 transition after multiple infections. In summary, we established a "multi-hit" WMI-induced CP rat model and demonstrated that the microglial activation correlates tightly with CP formation, which may become a potential target for future studies.
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Acute myeloid leukemia (AML) is a genetically heterogeneous hematological malignancy with poor prognosis. We explored the RNA sequence data and clinical information of AML patients from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) database to search for the core molecule for prognosis. The DC-STAMP expression was significantly higher in AML patients, which was linked to old age, unfavorable cytogenetic risk, and death (all p < 0.05). Furthermore, it was revealed that high DC-STAMP expression was an independent unfavorable factor for overall survival (OS) by univariate analysis [hazard ratio (HR): 2.683; 95% confidence interval (CI): 1.723-4.178; p < 0.001] and multivariate analysis (HR: 1.733; 95% CI: 1.079-2.781; p = 0.023). The concordance index (C-index 0.734, 95% CI: 0.706-0.762), calibration curves, and decision curve analysis showed the certain predictive accuracy of a nomogram model based on multivariate analysis for OS. In addition, we found that the differentially expressed gene (DEG) enrichment pathways of high- and low-DC-STAMP expression group enrichment pathways were focused on channel activity and platelet alpha granule by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), while gene set enrichment analysis (GSEA) pathways were mainly involved in mTORC1 signaling and TNF-α signaling via the NF-kB pathway. Moreover, a protein-protein interaction (PPI) network demonstrated that DC-STAMP interacted with two hub genes (PPBP and PF4), which were highly regulated and associated with poor survival. Finally, high DC-STAMP expression showed a significantly positive correlation with four immune cell [NK CD56 (dim) cells, macrophages, cytotoxic cells, and CD8 (+) T cells] infiltration and high level of immune checkpoint genes (PDCD1, CD274, CTLA-4, and TIGIT). Therefore, our results suggest that high expression of DC-STAMP predicts adverse outcomes for AML patients.
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TREX1 (three prime repair exonuclease 1) gene encodes DNA 3' end repair exonuclease that plays an important role in DNA repair. Mutations in TREX1 gene have been identified as the cause of a rare autoimmune neurological disease, Aicardi-Goutières syndrome (AGS). Here, we report an AGS case of a 6-month-old Chinese girl with novel TREX1 variants. The patient had mild rashes on the face and legs, increased muscle tensions in the limbs, and positive cervical correction reflex. Cranial magnetic resonance imaging showed that there were patches of slightly longer T1 and T2 signals in the bilateral cerebral hemisphere and brainstem white matter, mainly in the frontotemporal lobe, together with decreased white matter volume, enlarged ventricles, and widened sulcus fissure. Total exon sequencing showed that the TREX1 gene of the child had mutations of c.137_138insC and c.292_293insA, which had not been reported before. In addition, elevated type I interferons were detected by using enzyme-linked immunosorbent assay in the patient's serum. Together, our study demonstrated that novel TREX1 variants (c.137_138insC and c.292_293insA) cause AGS for the first time.