Mechanisms of action of the SGLT2 inhibitor canagliflozin on tubular inflammation and damage:A post-hoc mediation analysis of the CANVAS trial

AIMS: Exposure of tubular cells to albumin stimulates pro-inflammatory pathways including the release of Monocyte Chemoattractant Protein-1 (MCP-1) which may result in interstitial fibrosis and tubular damage reflected by increased urinary kidney injury molecule-1 (KIM-1). SGLT2 inhibition reduces urine albumin-creatinine ratio (UACR) and small studies suggest it also reduces MCP-1 and KIM-1. We hypothesised that the reduction in KIM-1 observed with the SGLT2 inhibitor canagliflozin is mediated through its effect on UACR and MCP-1. To test this hypothesis, we assessed the proportion of effect of canagliflozin on KIM-1 mediated through its effects on MCP-1 and UACR in patients with type 2 diabetes and albuminuric kidney disease. MATERIAL AND METHODS: KIM-1 and MCP-1 were measured in urine samples of the CANVAS trial at baseline and week 52 with the Mesoscale QuickPlex SQ 120 platform. KIM-1 and MCP-1 were standardized by urinary creatinine. The proportion of mediated effect of canagliflozin through UACR and MCP-1/Cr on KIM-1/Cr was estimated with G-computation. RESULTS: In total, 763 (17.6% of total cohort) patients with micro- or macroalbuminuria were included. Baseline characteristics were well balanced between the canagliflozin and placebo group. At year 1, canagliflozin compared to placebo reduced UACR, MCP-1/Cr, and KIM-1/Cr by 40.4% (95%CI 31.0, 48.4), 18.1% (95%CI 8.9, 26.4), and 30.9% (95%CI 23.0, 38.0), respectively. The proportion of the effect of canagliflozin on KIM-1/Cr mediated by its effect on UACR and in turn on MCP-1/Cr was 15.2% (95%CI 9.4, 24.5). CONCLUSION: Canagliflozin reduces urinary KIM-1 suggesting decreased tubular damage. This effect was partly mediated through a reduction in MCP-1, indicative of reduced tubular inflammation, which was in turn mediated by a reduction in UACR. This post-hoc analysis suggest that urinary albumin leakage may lead to tubular inflammation and induction of injury, and provide mechanistic insight for how canagliflozin may ameliorate tubular damage, but further research is required to confirm these findings. This article is protected by copyright. All rights reserved

Improving protein order-disorder classification using charge-hydropathy plots

BACKGROUND: The earliest whole protein order/disorder predictor (Uversky et al., Proteins, 41: 415-427 (2000)), herein called the charge-hydropathy (C-H) plot, was originally developed using the Kyte-Doolittle (1982) hydropathy scale (Kyte & Doolittle., J. Mol. Biol, 157: 105-132(1982)). Here the goal is to determine whether the performance of the C-H plot in separating structured and disordered proteins can be improved by using an alternative hydropathy scale. RESULTS: Using the performance of the CH-plot as the metric, we compared 19 alternative hydropathy scales, with the finding that the Guy (1985) hydropathy scale (Guy, Biophys. J, 47:61-70(1985)) was the best of the tested hydropathy scales for separating large collections structured proteins and intrinsically disordered proteins (IDPs) on the C-H plot. Next, we developed a new scale, named IDP-Hydropathy, which further improves the discrimination between structured proteins and IDPs. Applying the C-H plot to a dataset containing 109 IDPs and 563 non-homologous fully structured proteins, the Kyte-Doolittle (1982) hydropathy scale, the Guy (1985) hydropathy scale, and the IDP-Hydropathy scale gave balanced two-state classification accuracies of 79%, 84%, and 90%, respectively, indicating a very substantial overall improvement is obtained by using different hydropathy scales. A correlation study shows that IDP-Hydropathy is strongly correlated with other hydropathy scales, thus suggesting that IDP-Hydropathy probably has only minor contributions from amino acid properties other than hydropathy. CONCLUSION: We suggest that IDP-Hydropathy would likely be the best scale to use for any type of algorithm developed to predict protein disorder

Mediators of the effects of canagliflozin on kidney protection in patients with type 2 diabetes

Canagliflozin reduced kidney disease progression in participants with type 2 diabetes in the CANagliflozin cardioVascular Assessment Study (CANVAS) Program that explored potential mediators of the effects of canagliflozin on kidney outcomes. The percent mediating effect of 18 biomarkers indicative of disease was determined by comparing the hazard ratios for the effect of randomized treatment from an unadjusted model and from a model adjusting for the average post-randomization level of each biomarker. Multivariable analyses assessed the joint effects of biomarkers that mediated most strongly in univariable analyses. The kidney outcome was defined as a composite of 40% estimated glomerular filtration rate decline, end-stage kidney disease, or death due to kidney disease. Nine biomarkers (systolic blood pressure [8.9% of effect explained], urinary albumin:creatinine ratio [UACR; 23.9%], gamma glutamyltransferase [4.1%], hematocrit [51.1%], hemoglobin [41.3%], serum albumin [19.5%], erythrocytes [56.7%], serum urate [35.4%], and urine pH [7.5%]) individually mediated the effect of canagliflozin on the kidney outcome. In a parsimonious multivariable model, erythrocyte concentration, serum urate, and systolic blood pressure maximized cumulative mediation (115%). Mediating effects of UACR, but not other mediators, were highly dependent upon the baseline level of UACR: UACR mediated 42% and 7% of the effect in those with baseline UACR 30 mg/g or more and under 30 mg/g, respectively. The identified mediators support existing hypothesized mechanisms for the prevention of kidney outcomes with sodium glucose co-transporter 2 inhibitors. Thus, the disparity in mediating effects across baseline UACR subgroups suggests that the mechanism for kidney protection with canagliflozin may vary across patient subgroups

An exploration of the heterogeneity in effects of SGLT2 inhibition on cardiovascular and all-cause mortality in the EMPA-REG OUTCOME, CANVAS Program, DECLARE-TIMI 58, and CREDENCE trials

Background: Large-scale outcome trials of sodium glucose co-transporter 2 (SGLT2) inhibitors in patients with type 2 diabetes have identified consistent effects on major adverse cardiovascular events, heart failure, and progression of kidney disease. However, the magnitude of effects on cardiovascular and all-cause death appeared to vary between some of the studies. Methods: We explored the impact of differences in trial methodologies, participant characteristics, types of deaths, follow-up duration, effects on intermediate markers of risk, and drug selectivity for SGLT2 on the magnitude of the protective effect against fatal events achieved in the 4 trials. Results: The trial populations differed substantively in the proportions with baseline atherosclerotic cardiovascular disease history (99.2% in EMPA-REG OUTCOME to 40.6% in DECLARE-TIMI 58), and macroalbuminuria (88.0% in CREDENCE to 7.6% in the CANVAS Program). Meta-regression analyses identified no clear effect of these (both P > 0.09) or other participant characteristics on mortality benefits (all P > 0.55). Other differences between the trials (duration, selectivity of the SGLT2 inhibitor, or effects on intermediate markers of risk) also did not explain the heterogeneity in effects on mortality observed (all P > 0.30). Conclusion: No clear explanation for the statistical evidence of heterogeneity in effects of SGLT2 inhibition on fatal outcomes between the trials could be identified. While the analyses had limited statistical power, these results raise the possibility that the observed variations in treatment effects on fatal outcomes between trials may be at least partly due to chance

Reasons for hospitalizations in patients with type 2 diabetes mellitus in the CANVAS Program:a secondary analysis

AIMS: To determine the reasons for hospitalizations in the CANagliflozin cardioVascular Assessment Study (CANVAS) Program and the effects of the sodium glucose co-transporter 2 inhibitor canagliflozin on hospitalization. MATERIALS AND METHODS: A secondary analysis was performed on the CANVAS Program that included 10,142 participants with type 2 diabetes mellitus randomized to canagliflozin or placebo. The primary outcome was total (first plus all recurrent) all-cause hospitalization (ACH). Secondary outcomes were total hospitalizations categorized by the Medical Dictionary for Regulatory Activities hierarchy at the system organ class level, reported by investigators at each center. Outcomes were assessed using negative binomial models. RESULTS: Of the 7115 hospitalizations reported, the most common reasons were cardiac disorders (23.7%), infections and infestations (15.0%), and nervous system disorders (9.0%). The rate of total ACH was lower in the canagliflozin group (n=5795) compared to the placebo group (n=4347): 197.9 versus 215.8 participants per 1000 patient-years, respectively (rate ratio [RR] 0.92; 95% confidence interval [CI] 0.86, 0.98). Canagliflozin reduced the rate of total hospitalizations due to cardiac disorders (RR 0.81; 95% CI 0.75, 0.88). There was no significant difference between the canagliflozin and placebo groups in the rates of total hospitalizations due to infections and infestations (RR 0.96; 95% CI 0.86, 1.02) or nervous system disorders (RR 0.96; 95% CI 0.88, 1.05). CONCLUSIONS: In the CANVAS Program, the most common reasons for hospitalization were cardiac disorders, infections and infestations, and nervous system disorders. Canagliflozin, compared with placebo, reduced the rate of total ACH. This article is protected by copyright. All rights reserved

Glutathione-complexed iron–sulfur clusters: reaction intermediates and evidence for a template effect promoting assembly and stability

Assembly and stabilization of a glutathione-complexed [2Fe–2S] cluster is promoted by aggregation of glutathione. The cluster core selects the tetramer species from a collection of equilibrating solution aggregate species, and in turn the core is stabilized toward hydrolytic degradation. Studies of glutathione derivatives, in combination with mass spectrometric and Mossbauer investigations provide insight on reaction intermediates during formation of [2Fe–2S](GS)₄²⁻.Facultad de Ciencias Exacta

Phase boundary engineering of metal-organic-framework-derived carbonaceous nickel selenides for sodium-ion batteries

Abstract: Sodium-ion batteries (SIBs) are promising power sources due to the low cost and abundance of battery-grade sodium resources, while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode materials. Metal-organic framework (MOFs) derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition, nanostructure, chemical and physical properties. Here, we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage capability. As MOF formation time increases, the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2, with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell structures. As SIBs anodes, bi-phase NiSex@C/CNT-10h (10 h of hydrothermal synthesis time) exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g, long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 cycles. Computational simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium storage. Our understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries, catalysis, sensors, and environmental remediation

Functional interplay of Epstein-Barr virus oncoproteins in a mouse model of B cell lymphomagenesis.

Epstein-Barr virus (EBV) is a B cell transforming virus that causes B cell malignancies under conditions of immune suppression. EBV orchestrates B cell transformation through its latent membrane proteins (LMPs) and Epstein-Barr nuclear antigens (EBNAs). We here identify secondary mutations in mouse B cell lymphomas induced by LMP1, to predict and identify key functions of other EBV genes during transformation. We find aberrant activation of early B cell factor 1 (EBF1) to promote transformation of LMP1-expressing B cells by inhibiting their differentiation to plasma cells. EBV EBNA3A phenocopies EBF1 activities in LMP1-expressing B cells, promoting transformation while inhibiting differentiation. In cells expressing LMP1 together with LMP2A, EBNA3A only promotes lymphomagenesis when the EBNA2 target Myc is also overexpressed. Collectively, our data support a model where proproliferative activities of LMP1, LMP2A, and EBNA2 in combination with EBNA3A-mediated inhibition of terminal plasma cell differentiation critically control EBV-mediated B cell lymphomagenesis

A novel fault diagnosis method for rotating machinery based on S transform and morphological pattern spectrum

With the continuing expansion of the applications of rotating machinery, an earlier and more accurate fault diagnosis method is required. In this paper, a novel characterization method based on S transform and morphological pattern spectrum (ST-MPS) was put forward. In order to verify the application of the method, ST-MPS was applied to a set of experimental signals obtained in a bearing test bench, and the results verified that the proposed feature extraction method is an effective approach to accurately classify the types of bearing fault

Mouse Papillomavirus L1 and L2 Are Dispensable for Viral Infection and Persistence at Both Cutaneous and Mucosal Tissues.

Papillomavirus L1 and L2, the major and minor capsid proteins, play significant roles in viral assembly, entry, and propagation. In the current study, we investigate the impact of L1 and L2 on viral life cycle and tumor growth with a newly established mouse papillomavirus (MmuPV1) infection model. MmuPV1 L1 knockout, L2 knockout, and L1 plus L2 knockout mutant genomes (designated as L1ATGko-4m, L2ATGko, and L1-L2ATGko respectively) were generated. The mutants were examined for their ability to generate lesions in athymic nude mice. Viral activities were examined by qPCR, immunohistochemistry (IHC), in situ hybridization (ISH), and transmission electron microscopy (TEM) analyses. We demonstrated that viral DNA replication and tumor growth occurred at both cutaneous and mucosal sites infected with each of the mutants. Infections involving L1ATGko-4m, L2ATGko, and L1-L2ATGko mutant genomes generally resulted in smaller tumor sizes compared to infection with the wild type. The L1 protein was absent in L1ATGko-4m and L1-L2ATGko mutant-treated tissues, even though viral transcripts and E4 protein expression were robust. Therefore, L1 is not essential for MmuPV1-induced tumor growth, and this finding parallels our previous observations in the rabbit papillomavirus model. Very few viral particles were detected in L2ATGko mutant-infected tissues. Interestingly, the localization of L1 in lesions induced by L2ATGko was primarily cytoplasmic rather than nuclear. The findings support the hypothesis that the L2 gene influences the expression, location, transport, and assembly of the L1 protein in vivo