Effects of Early Changes in Organ Dysfunctions on the Outcomes of Critically Ill Patients in Need of Renal Replacement Therapy

INTRODUCTION: Acute kidney injury usually develops in critically ill patients in the context of multiple organ dysfunctions. OBJECTIVE: To evaluate the effect of changes in associated organ dysfunctions over the first three days of renal replacement therapy on the outcomes of patients with acute kidney injury. METHODS: Over a 19-month period, we evaluated 260 patients admitted to the intensive care units of three tertiary-care hospitals who required renal replacement therapy for > 48 h. Organ dysfunctions were evaluated by SOFA score (excluding renal points) on the first (D1) and third (D3) days of renal replacement therapy. Absolute (A-SOFA) and relative (D-SOFA) changes in SOFA scores were also calculated. RESULTS: Hospital mortality rate was 75%. Organ dysfunctions worsened (A-SOFA>0) in 53%, remained unchanged (A-SOFA=0) in 17% and improved (A-SOFA<0) in 30% of patients; and mortality was lower in the last group (80% vs. 84% vs. 61%, p=0.003). SOFA on D1 (p<0.001), SOFA on D3 (p<0.001), A-SOFA (p=0.019) and D-SOFA (p=0.016) were higher in non-survivors. However, neither A-SOFA nor D-SOFA discriminated survivors from non-survivors on an individual basis. Adjusting for other covariates (including SOFA on D1), A-SOFA and D-SOFA were associated with increased mortality, and patients in whom SOFA scores worsened or remained unchanged had poorer outcomes. CONCLUSIONS: In addition to baseline values, early changes in SOFA score after the start of renal replacement therapy were associated with hospital mortality. However, no prognostic score should be used as the only parameter to predict individual outcomes

O-Glycosylation Regulates Ubiquitination and Degradation of the Anti-Inflammatory Protein A20 to Accelerate Atherosclerosis in Diabetic ApoE-Null Mice

Background: Accelerated atherosclerosis is the leading cause of morbidity and mortality in diabetic patients. Hyperglycemia is a recognized independent risk factor for heightened atherogenesis in diabetes mellitus (DM). However, our understanding of the mechanisms underlying glucose damage to the vasculature remains incomplete. Methodology/Principal Findings: High glucose and hyperglycemia reduced upregulation of the NF-κB inhibitory and atheroprotective protein A20 in human coronary endothelial (EC) and smooth muscle cell (SMC) cultures challenged with Tumor Necrosis Factor alpha (TNF), aortae of diabetic mice following Lipopolysaccharide (LPS) injection used as an inflammatory insult and in failed vein-grafts of diabetic patients. Decreased vascular expression of A20 did not relate to defective transcription, as A20 mRNA levels were similar or even higher in EC/SMC cultured in high glucose, in vessels of diabetic C57BL/6 and FBV/N mice, and in failed vein grafts of diabetic patients, when compared to controls. Rather, decreased A20 expression correlated with post-translational O-Glucosamine-N-Acetylation (O-GlcNAcylation) and ubiquitination of A20, targeting it for proteasomal degradation. Restoring A20 levels by inhibiting O-GlcNAcylation, blocking proteasome activity, or overexpressing A20, blocked upregulation of the receptor for advanced glycation end-products (RAGE) and phosphorylation of PKCβII, two prime atherogenic signals triggered by high glucose in EC/SMC. A20 gene transfer to the aortic arch of diabetic ApoE null mice that develop accelerated atherosclerosis, attenuated vascular expression of RAGE and phospho-PKCβII, significantly reducing atherosclerosis. Conclusions: High glucose/hyperglycemia regulate vascular A20 expression via O-GlcNAcylation-dependent ubiquitination and proteasomal degradation. This could be key to the pathogenesis of accelerated atherosclerosis in diabetes

Desempenho de seis modelos de predição prognóstica em pacientes críticos que receberam suporte renal extracorpóreo Performance of six prognostic scores in critically ILL patients receiving renal replacement therapy

JUSTIFICATIVA E OBJETIVOS: Não existe consenso sobre qual modelo prognóstico deva ser utilizado em pacientes com disfunção renal aguda (DRA). O objetivo deste estudo foi avaliar o desempenho de seis escores de prognóstico em pacientes que necessitaram de suporte renal. MÉTODO: Coorte prospectiva de pacientes internados nas unidades de terapia intensiva (UTI) de três hospitais terciários que necessitaram de suporte renal por DRA durante 32 meses. Foram excluídos os pacientes crônicos em programa de diálise ou com < 24h de internação na UTI. Os dados das primeiras 24h de UTI foram utilizados no cálculo do SAPS II e do APACHE II, e os dados das primeiras 24h de suporte renal foram utilizados no cálculo dos escores LOD, ODIN, Liaño e Mehta. A discriminação foi avaliada através da área sobre a curva ROC (AUROC) e a calibração através do teste do goodness-of-fit de Hosmer-Lemeshow. A letalidade hospitalar foi o desfecho de interesse. RESULTADOS: Quatrocentos e sesseta e sete pacientes foram incluídos e a letalidade hospitalar foi 75%. Os valores dos escores SAPS II, APACHE II e LOD foram 48,5 ± 11,2, 27,4 ± 6,3, 7 (5-8) pontos, respectivamente. A calibração foi adequada para todos os escores, com exceção do Mehta (p = 0,001). Entretanto, a discriminação foi ruim para todos os modelos, com AUROC variando entre 0,60 para o ODIN e 0,72 para o SAPS II e Mehta. Com exceção do Mehta, todos os modelos subestimaram a letalidade. CONCLUSÕES: Todos os seis modelos estudados foram inadequados na predição prognóstica de pacientes graves com DRA e necessidade de suporte renal.<br>BACKGROUND AND OBJECTIVES: There is no consensus about prognostic scores for use in patients with acute kidney injury (AKI). The aim of this study was to evaluate the performance of six prognostic scores in predicting hospital mortality in patients with AKI and need for renal replacement therapy (RRT). METHODS: Prospective cohort of patients admitted to the intensive care units (ICU) of three tertiary care hospitals that required RRT for AKI over a 32-month period. Patients with end-stage renal disease and those with ICU stay < 24h were excluded. Data from the first 24h of ICU admission were used to calculate SAPS II and APACHE II scores, and data from the first 24h of RRT were used in the calculation of LOD, ODIN, Liaño and Mehta scores. Discrimination was evaluated using the area under ROC curve (AUROC) and calibration using the Hosmer-Lemeshow goodness-of-fit test. The hospital mortality was the end-point of interest. RESULTS: 467 patients were evaluated. Hospital mortality rate was 75%. Mean SAPS II and APACHE II scores were 48.5 ±11.2 and 27.4 ± 6.3 points, and median LOD score was 7 (5-8) points. Except for Mehta score (p = 0.001), calibration was appropriate in all models. However, discrimination was uniformly unsatisfactory; AUROC ranged from 0.60 for ODIN to 0.72 for SAPS II and Mehta scores. In addition, except for Mehta, all models tended to underestimate hospital mortality. CONCLUSIONS: Organ dysfunction, general and renal-specific severity-of-illness scores were inaccurate in predicting outcome in ICU patients in need for RRT

Expression of A20 in the ascending aorta and aortic arch of diabetic ApoE-null mice prevents the development of atherosclerotic lesions by inhibiting PKCβII phosphorylation and blunting the induction of RAGE.

<p>(A) Transgene expression was confirmed by X-gal staining in rAd.βgal-transduced vessels 5 days following transgene delivery (n = 3 mice/group) and demonstrate the expression of the transgene in medial SMC (M) as well as the adventitia at the level of the aortic root, albeit not in all cells. Image amplification 100× and 400×. (B) A20 expression was verified by real time RT-PCR in two rAd.A20-transduced vessels, using human A20 specific primers that do not recognize mouse A20. Our data indicate significant expression of human A20 in aortic roots of rAd.A20 but not saline treated mice. Results are shown as average± SE. (C) H&E stained aortic root sections at the level of the first coronary from 20 week-old diabetic ApoE-null mice treated with saline, rAd.A20 or rAd.βgal. Images are shown at 100× and 400× as indicated by the scale bar. The asterisk indicates the level of the first coronary branch, Arrows define the intima (I) and the media (M). ApoE-competent, non-diabetic C57BL/6 and non-diabetic ApoE-null mice were used as controls. Blood glucose and cholesterol levels (cholest) are listed below the sections. *P<0.05 compared to saline, ** P<0.01 compared to rAd. βGal. Data shown are representative of 4 to 6 mice per group. I/M ratios were calculated after analysis of 10 serial sections per vessel. (D) phospho-(p)PKCβII (5 days) and RAGE (14 days) immunostaining in aortic arches 5 and 14 days after transgene delivery. Data shown in C are representative of all sections analyzed (n = 3 mice per group, 2–3 sections analyzed per vessel). Image amplification 200×.</p

Increasing glucose (D-Glu) concentrations decreases TNF-mediated A20 protein up-regulation without affecting its transcriptional activation in EC.

<p>(A) Analysis of A20 expression by WB. EC cultured in medium containing 5, 15 or 30 mM D-glucose (D-Glu) or L-glucose (L-Glu), as an osmotic control, were stimulated with TNF for 6 h˜βactin was checked as loading control and to quantify relative A20 expression by densitometry, as reported below the WB. Densitometry of the bands of interest and was determined as the mean intensity of the areas delineated by Image J, then corrected by the main intensity of the corresponding house keeping gene band. Fold induction was determined using the non-treated 5 mM D-glucose condition sample as one (1). A20 protein migrates as a doublet in EC and hence both bands were scanned. Data are representative of 3 independent experiments. (B) Analysis of A20 mRNA levels by real-time PCR. EC cultured in medium containing 5, 15 or 30 mM D-Glu or L-Glu as an osmotic control, were stimulated with TNF for 1 and 3 h. Expression of 18S ribosomal RNA was used to normalize the expression of A20 mRNA. Natural log transformed data (ln) are presented as mean±SEM of 3 independent experiments performed in duplicate. No significant differences (P>0.05) were observed between all groups and at all time-points.</p

Restoring A20 levels reverts glucose-mediated upregulation of RAGE and phosphorylation of PKCβII.

<p>(A) WB analysis for RAGE and A20 expression in SMC cultured in 5 or 30 mM D-Glu for 24 h and treated with TNF in the presence or absence of 20 mM of Azaserine (prior to TNF) or 10 mM of MG132 (following TNF). Corrected RAGE fold-inductions are listed below the WB. The RAGE protein is detected as a doublet as a result of pre and post-N-glycosylated form of the protein. Both bands were used for densitometry evaluation. (B) WB analysis of phospho-PKCβII (pPKCβII) and total (c) PKCβII in NT SMC, and in SMC transduced with rAd.A20 or rAd.βgal, and treated with PMA or challenged with 30 mM D-Glu for 1 h. Data shown in A and B are representative of 3 independent experiments. NT = non-transduced cells. GAPDH was used as loading control to quantify the relative expression of RAGE and pPKCβII by densitometry.</p

High glucose promotes A20 O-glycosylation, ubiquitination and proteasomal degradation in EC and SMC.

<p>High glucose increases protein O-GlcNAcylation, including that of A20 and possibly other E3 Ubiquitin ligases. This leads to increased A20 ubiquitination either through auto-ubiquitination or increased activity of other O-GlcNAcylated E3 ubiquitin ligases. This targets A20 for degradation in the proteasome. Blockade of O-GlcNAcylation using DON, upstream of A20 Ubiquitination, or inhibition of proteasome activity, using MG132, downstream of A20 ubiquitination would inhibit its proteasomal degradation, restoring its expected protein levels.</p

O-GlcNAcylation and ubiquitination of A20 modulate its expression.

<p>(A) WB analysis of total A20 and co-immunoblotted, overlapping GlcNAc-A20 (RL-2) in SMC cultured in 5, 15 and 30 mM of D-glucose (D-Glu), and treated or not with TNF for 6 h. β-actin was used as a control for loading. (B) WB analysis of WGA captured proteins from SMC cultured in 5 and 30 mM D-Glu demonstrate the presence of glycosylated (GlcNAcA20), and co-immunoblotted, overlapping, ubiquitinated A20 (Ub-A20). (C) WB analysis of cell lysates immunoprecipitated with the A20 antibody from SMC cultured in 5 and 30 mM of D-Glu and treated or not with TNF for 6 h, and analyzed WB for total A20 and GlcNAc-A20 using the RL2 antibody demonstrate increased GlcNAc-A20 in high glucose medium. (D) WB analysis of cell lysates immunoprecipitated with the A20 antibody from SMC cultured in 5 and 30 mM D-Glu and treated or not with TNF for 6 h, and analyzed by WB for total and Ub-A20 demonstrate increased Ub-A20 in high glucose medium. (E) WB analysis of total and overlapping GlcNAc-A20 (RL-2) in SMC cultured in 30 mM D-Glu and treated with DON (prior to TNF) or MG132 (after TNF). (F) WB analysis of total and phospho-A20 in SMC cultured in 5, 15 and 30 mM D-Glu and treated with TNF for 6 h demonstrated that relative phosphorylation levels of A20 (pA20) were not decreased by high glucose, despite decreased TNF-mediated upregulation of A20 protein in cells cultured in high glucose. GAPDH or βactin was checked as a loading control to quantify A20 expression by densitometry. Corrected A20 fold-inductions are listed below the WB. RL2/A20 and Ubiquitin/A20 ratios were also calculated by densitometry. Data shown in A, C, D, and E are representative of 3 independent experiments. Data shown in B and F are representative of 2 independent experiments.</p