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13 result(s) for "Bu, Simeng"
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Antibacterial activity of ruthenium polypyridyl complexes against Staphylococcus aureus and biofilms
There is clearly a need for the development of new classes of antimicrobials to fight against multidrug-resistant bacteria. Here, we designed and synthesized of three ruthenium polypyridyl complexes: [Ru(bpy) 2 (BTPIP)](ClO 4 ) 2 ( Ru(II)-1 ), [Ru(bpy) 2 (ETPIP)](ClO 4 ) 2 ( Ru(II)-2 ) and [Ru(bpy) 2 (CAPIP)](ClO 4 ) 2 ( Ru(II)-3 ) ( N - N  = bpy = 2,2′-bipyridine), their antimicrobial activities against S. aureus were assessed. The lead complexes of this set, Ru(II)-1 (MIC = 0.016 mg/mL), was tested against biofilm. We also investigated whether bacteria can easily develop resistance to Ru(II)-1 . The result demonstrated that S. aureus could not easily develop resistance to the ruthenium complexes. In addition, aimed to test whether ruthenium complexes treatment could increase the susceptibility of S. aureus to antibiotics, the synergism between Ru(II)-1 and common antibiotics against S. aureus were investigated using the checkerboard method. Interesting, Ru(II)-1 could increased the susceptibility of S. aureus to some aminoglycoside antibiotics(kanamycin and gentamicin). Finally, in vivo bacterial infection treatment studies were also conducted through murine skin infection model. These results confirmed ruthenium complexes have good antimicrobial activity in vitro and in vivo. Graphic abstract
Gut Leakage of Fungal‐Related Products: Turning Up the Heat for HIV Infection
The intestinal epithelial layer serves as a physical and functional barrier between the microbiota in the lumen and immunologically active submucosa. Th17 T-cell function protects the gut epithelium from aggression from microbes and their by-products. Loss of barrier function has been associated with enhanced translocation of microbial products which act as endotoxins, leading to local and systemic immune activation. Whereas the inflammatory role of LPS produced by Gram-negative bacteria has been extensively studied, the role of fungal products such as β-D-glucan remains only partially understood. As HIV infection is characterized by impaired gut Th17 function and increased gut permeability, we critically review mechanisms of immune activation related to fungal translocation in this viral infection. Additionally, we discuss markers of fungal translocation for diagnosis and monitoring of experimental treatment responses. Targeting gut barrier dysfunction and reducing fungal translocation are emerging strategies for the prevention and treatment of HIV-associated inflammation and may prove useful in other inflammatory chronic diseases.
Proteomics validate circulating GDF-15 as an independent biomarker for COVID-19 severity
Growth differentiation factor 15 (GDF-15) was originally described as a stress-induced cytokine, and a biomarker of aging and cardiovascular diseases. We hypothesized that circulating GDF-15 would be associated with COVID-19 disease severity. Herein, we explored this hypothesis in a large cohort of COVID-19 patients. Blood samples were collected from 926 COVID-19 adult patients and from 285 hospitalized controls from the Biobanque Québécoise de la COVID-19 (BQC19). COVID-19 severity was graded according to the WHO criteria. SOMAscan proteomics assay was performed on 50µL of plasma. ELISA were performed on 46 selected participants with left-over plasma to validate differences in plasma GDF-15 levels. Statistical analyses were conducted using GraphPad Prism 9.0 and SPSS. P values < 0.01 were considered significant. Proteomics showed that plasma GDF-15 levels were higher in COVID-19 patients compared to hospitalized controls. GDF-15 levels increased with COVID-19 severity. COVID-19 patients presenting with comorbidities including diabetes, cancer, chronic obstructive pulmonary disease (COPD) and cardiovascular disease had higher GDF-15 levels. ELISA revealed significant elevation of GDF-15 until 30 days after hospitalization. Plasma GDF-15 elevation was correlated with older age. Moreover, GDF-15 levels correlated with pro-inflammatory cytokine interleukin-6 (IL-6) and inflammation marker C-reactive protein (CRP) as well as soluble levels of its putative receptor CD48. No association was established between anti-SARS-CoV-2 IgG levels and plasma GDF-15 levels. This study confirms GDF-15 as a biomarker for COVID-19 severity. Clinical evaluation of GDF-15 levels could assist identification of persons at high-risk of progressing to severe disease, thus improving patient care.
Extracellular acyl-CoA-binding protein as an independent biomarker of COVID-19 disease severity
Factors leading to severe COVID-19 remain partially known. New biomarkers predicting COVID-19 severity that are also causally involved in disease pathogenesis could improve patient management and contribute to the development of innovative therapies. Autophagy, a cytosolic structure degradation pathway is involved in the maintenance of cellular homeostasis, degradation of intracellular pathogens and generation of energy for immune responses. Acyl-CoA binding protein (ACBP) is a key regulator of autophagy in the context of diabetes, obesity and anorexia. The objective of our work was to assess whether circulating ACBP levels are associated with COVID-19 severity, using proteomics data from the plasma of 903 COVID-19 patients. Somalogic proteomic analysis was used to detect 5000 proteins in plasma samples collected between March 2020 and August 2021 from hospitalized participants in the province of Quebec, Canada. Plasma samples from 903 COVID-19 patients collected during their admission during acute phase of COVID-19 and 295 hospitalized controls were assessed leading to 1198 interpretable proteomic profiles. Levels of anti-SARS-CoV-2 IgG were measured by ELISA and a cell-binding assay. The median age of the participants was 59 years, 46% were female, 65% had comorbidities. Plasma ACBP levels correlated with COVID-19 severity, in association with inflammation and anti-SARS-CoV-2 antibody levels, independently of sex or the presence of comorbidities. Samples collected during the second COVID-19 wave in Quebec had higher levels of plasma ACBP than during the first wave. Plasma ACBP levels were negatively correlated with biomarkers of T and NK cell responses interferon-γ, tumor necrosis factor-α and interleukin-21, independently of age, sex, and severity. Circulating ACBP levels can be considered a biomarker of COVID-19 severity linked to inflammation. The contribution of extracellular ACBP to immunometabolic responses during viral infection should be further studied.
Distinct Plasma Concentrations of Acyl-CoA-Binding Protein (ACBP) in HIV Progressors and Elite Controllers
HIV elite controllers (ECs) are characterized by the spontaneous control of viral replication, and by metabolic and autophagic profiles which favor anti-HIV CD4 and CD8 T-cell responses. Extracellular acyl coenzyme A binding protein (ACBP) acts as a feedback inhibitor of autophagy. Herein, we assessed the circulating ACBP levels in ECs, compared to people living with HIV (PLWH) receiving antiretroviral therapy (ART) or not. We found lower ACBP levels in ECs compared to ART-naïve or ART-treated PLWH (p < 0.01 for both comparisons), independently of age and sex. ACBP levels were similar in ECs and HIV-uninfected controls. The expression of the protective HLA alleles HLA-B*27, *57, or *58 did not influence ACBP levels in ECs. ACBP levels were not associated with CD4 or CD8 T-cell counts, CD4 loss over time, inflammatory cytokines, or anti-CMV IgG titers in ECs. In ART-treated PLWH, ACBP levels were correlated with interleukin (IL)-1β levels, but not with other inflammatory cytokines such as IL-6, IL-8, IL-32, or TNF-α. In conclusion, ECs are characterized by low ACBP plasma levels compared to ART-naïve or ART-treated PLWH. As autophagy is key to anti-HIV CD4 and CD8 T-cell responses, the ACBP pathway constitutes an interesting target in HIV cure strategies.
Translocation of bacterial LPS is associated with self-reported cognitive abilities in men living with HIV receiving antiretroviral therapy
Background Gut damage allows translocation of bacterial lipopolysaccharide (LPS) and fungal β-D-glucan (BDG) into the blood. This microbial translocation contributes to systemic inflammation and risk of non-AIDS comorbidities in people living with HIV, including those receiving antiretroviral therapy (ART). We assessed whether markers of gut damage and microbial translocation were associated with cognition in ART-treated PLWH. Methods Eighty ART-treated men living with HIV from the Positive Brain Health Now Canadian cohort were included. Brief cognitive ability measure (B-CAM) and 20-item patient deficit questionnaire (PDQ) were administered to all participants. Three groups were selected based on their B-CAM levels. We excluded participants who received proton pump inhibitors or antiacids in the past 3 months. Cannabis users were also excluded. Plasma levels of intestinal fatty acid binding protein (I-FABP), regenerating islet-derived protein 3 α (REG3α), and lipopolysaccharides (LPS = were quantified by ELISA, while 1–3-β-D-glucan BDG) levels were assessed using the Fungitell assay. Univariable, multivariable, and splines analyses were performed. Results Plasma levels of I-FABP, REG3α, LPS and BDG were not different between groups of low, intermediate and high B-CAM levels. However, LPS and REG3α levels were higher in participants with PDQ higher than the median. Multivariable analyses showed that LPS association with PDQ, but not B-CAM, was independent of age and level of education. I-FABP, REG3α, and BDG levels were not associated with B-CAM nor PDQ levels in multivariable analyses. Conclusion In this well characterized cohort of ART-treated men living with HIV, bacterial but not fungal translocation was associated with presence of cognitive difficulties. These results need replication in larger samples.
Influence of letermovir treatment on gut inflammation in people living with HIV on antiretroviral therapy: protocol of the open-label controlled randomised CIAO study
IntroductionChronic cytomegalovirus (CMV) infection is very frequent in people living with HIV (PLWH). High anti-CMV IgG titres, which may be linked to transient CMV replication, have been associated with earlier mortality, CD8 T-cell expansion, lower CD4/CD8 ratio and increased T-cell senescence. We previously showed that anti-CMV IgG titres correlated with gut permeability in PLWH on antiretroviral therapy (ART), which was associated with microbial translocation, systemic inflammation and non-infectious/non-AIDS comorbidities. Letermovir, a novel anti-CMV drug with a good safety profile, was recently approved for anti-CMV prophylaxis in allogeneic haematopoietic stem cell transplant recipients. A drastic and selective reduction of both low-grade replication and clinically significant CMV infections, combined with an improved immune reconstitution have been reported. In vitro, letermovir prevented CMV-induced epithelial disruption in intestinal tissues. Based on these findings, we aim to assess whether letermovir could inhibit CMV subclinical replication in CMV-seropositive PLWH receiving ART and, in turn, decrease CMV-associated gut damage and inflammation.Method and analysisWe will conduct a multi-centre, open-label, randomised, controlled clinical trial, including a total of 60 CMV-seropositive ART-treated PLWH for at least 3 years, with a viral load <50 copies/mL and CD4+ count >400 cells/µL. Forty participants will be randomised to receive letermovir for 14 weeks and 20 participants will receive standard of care (ART) alone. Plasma, pheripheral blood mononuclear cells (PBMCs), and stool samples will be collected. Colon biopsies will be collected in an optional substudy. We will assess the effect of letermovir on gut damage, microbial translocation, inflammation and HIV reservoir size.Ethics and disseminationThe study was approved by Health Canada and the Research Ethics Boards of the McGill University Health Centre (MUHC-REB, protocol number: MP37-2022-8295). Results will be made available through publications in open access peer-reviewed journals and through the CIHR/CTN website.Trial registration numberNCT05362916.
Camu Camu effects on microbial translocation and systemic immune activation in ART-treated people living with HIV: protocol of the single-arm non-randomised Camu Camu prebiotic pilot study (CIHR/CTN PT032)
IntroductionDespite the success of antiretroviral therapy (ART) in transforming HIV disease into a chronic infection, people living with HIV (PLWH) remain at risk for various non-AIDS inflammatory comorbidities. Risk of non-AIDS comorbidities is associated with gut dysbiosis, epithelial gut damage and subsequent microbial translocation, and increased activation of both circulating CD4+ and CD8+ T-cells. Therefore, in addition to ART, novel gut microbiota-modulating therapies could aid in reducing inflammation and immune activation, gut damage, and microbial translocation. Among various gut-modulation strategies under investigation, the Amazonian fruit Camu Camu (CC) presents itself as a prebiotic candidate based on its anti-inflammatory and antioxidant properties in animal models and tobacco smokers.Method and analysisA total of 22 PLWH on ART for more than 2 years, with a viral load <50 copies/mL, a CD4 +count >200 and a CD4+/CD8 +ratio <1 (suggesting increased inflammation and risk for non-AIDS comorbidities), will be recruited in a single arm, non-randomised, interventional pilot trial. We will assess tolerance and effect of supplementation with CC in ART-treated PLWH on reducing gut damage, microbial translocation, inflammation and HIV latent reservoir by various assays.Ethics and disseminationThe Canadian Institutes of Health Research (CIHR)/Canadian HIV Trials Network (CTN) pilot trial protocol CTNPT032 was approved by the Natural and Non-prescription Health Products Directorate of Health Canada and the research ethics board of the McGill university Health Centre committee (number 2020-5903). Results will be made available as free access through publications in peer-reviewed journals and through the CIHR/CTN website.Trial registration numberNCT04058392.
Opposite Influences of Bacterial and Fungal Translocation on Immune Responses During COVID-19
BackgroundSARS-CoV-2 infection causes damage to the gut epithelium, allowing translocation of bacterial (lipopolysaccharide, LPS) and fungal (beta-glucan, BDG) products into circulation, contributing to inflammation. High circulating BDG levels are associated with immune activation and disease severity, underscoring the crucial role of gut permeability in COVID-19 disease progression. Currently, the influence of microbial translocation on the function of the immune system during COVID-19 infection remains unknown. We hypothesize that markers of mucosal damage, microbial translocation and inflammation will elevate during acute COVID-19 and associate with weaker anti-SARS-CoV-2 T and B-cells immune response.MethodsHerein, we analyzed plasma and peripheral blood mononuclear cells (PBMCs) obtained from 19 acute and 15 recovered (> 6 months) COVID-19 participants. We measured plasma levels of BDG using the Fungitell assay, assessed plasma levels of I-FABP, LPS, REG3α via ELISA. PBMCs were stimulated with SARS-CoV-2 Spike peptides and T-cell production of IFN-γ, IL-2 and TNF-α were assessed using flow cytometry. Anti-SARS-CoV-2 IgG antibody levels were measured in plasma using MSD ELISA.ResultsIn acute participants, spike-specific CD4 T-cell IL-2 response was positively correlated with plasma BDG levels. In recovered participants, polyfunctional spike-specific CD4 and CD8 T-cell responses were negatively correlated with BDG, while CD4 T-cell response was positively correlated with LPS levels. Antibody levels also negatively correlated with BDG and positively correlated with LPS in the recovered group. No correlation was found between gut permeability markers and spike-specific immune responses.ConclusionOur findings suggest contrasting effects of bacterial and fungal translocation on immune response in COVID-19. Further investigation is required to elucidate the link between these observations and the efficiency of the immune responses against SARS-CoV-2.
Prediction of anxious depression using multimodal neuroimaging and machine learning
•AD patients exhibit brain dysregulation in emotion, cognition and decision regions.•Alterations in regions like left ITG, STG, ORBsup, etc., may indicate anxious depression.•Predictive model differentiated anxious from non-anxious MDD with an AUC of 0.802. Anxious depression is a common subtype of major depressive disorder (MDD) associated with adverse outcomes and severely impaired social function. It is important to clarify the underlying neurobiology of anxious depression to refine the diagnosis and stratify patients for therapy. Here we explored associations between anxiety and brain structure/function in MDD patients. A total of 260 MDD patients and 127 healthy controls underwent three-dimensional T1-weighted structural scanning and resting-state functional magnetic resonance imaging. Demographic data were collected from all participants. Differences in gray matter volume (GMV), (fractional) amplitude of low-frequency fluctuation ((f)ALFF), regional homogeneity (ReHo), and seed point-based functional connectivity were compared between anxious MDD patients, non-anxious MDD patients, and healthy controls. A random forest model was used to predict anxiety in MDD patients using neuroimaging features. Anxious MDD patients showed significant differences in GMV in the left middle temporal gyrus and ReHo in the right superior parietal gyrus and the left precuneus than HCs. Compared with non-anxious MDD patients, patients with anxious MDD showed significantly different GMV in the left inferior temporal gyrus, left superior temporal gyrus, left superior frontal gyrus (orbital part), and left dorsolateral superior frontal gyrus; fALFF in the left middle temporal gyrus; ReHo in the inferior temporal gyrus and the superior frontal gyrus (orbital part); and functional connectivity between the left superior temporal gyrus(temporal pole) and left medial superior frontal gyrus. A diagnostic predictive random forest model built using imaging features and validated by 10-fold cross-validation distinguished anxious from non-anxious MDD with an AUC of 0.802. Patients with anxious depression exhibit dysregulation of brain regions associated with emotion regulation, cognition, and decision-making, and our diagnostic model paves the way for more accurate, objective clinical diagnosis of anxious depression.