Acute kidney injury

Delivery of coenzyme Q10 with mitochondria-targeted nanocarrier attenuates renal ischemia-reperfusion injury in mice

Ischemia-reperfusion (I/R) injury causes high morbidity, mortality, and healthcare costs. I/R induces acute kidney injury through exacerbating the mitochondrial damage and increasing inflammatory and oxidative responses. Here, we developed the mitochondria-targeted nanocarrier to delivery of Coenzyme Q10 (CoQ10) for renal I/R treatment in animal model. The mitochondria-targeted TPP CoQ10 nanoparticles (T-NP_CoQ10) were synthesized through ABC miktoarm polymers method and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The I/R mouse model and oxygen-glucose deprivation/reperfusion (D/R) model were created to examine the role of T-NP_CoQ10 on renal I/R. Mitochondrial DNA damage, apoptosis, and inflammatory cytokines were measured in I/R injury mice. Plasma creatinine, urea nitrogen, tubular injury score was tested to assess the renal function. T-NP_CoQ10 nanoparticles could be delivered to renal mitochondria preciously and efficiently. T-NP_CoQ10 administration attenuated oxidative injury in both cell and animal models significantly, alleviated mtDNA damage, suppressed inflammatory and apoptotic responses, and improved renal function. The mitochondria specific CoQ10 delivery provided a precious and efficient method for protecting inflammatory and oxidative responses of I/R-induced renal damage.

Impact of and risk factors for pediatric acute kidney injury defined by the pROCK criteria in a Chinese PICU population

BACKGROUND

The definition of pediatric AKI continues to evolve. We aimed to find a better AKI definition to predict outcomes and identify risk factors for AKI in a Chinese PICU.

METHODS

This study consisted of 3338 patients hospitalized in a Chinese PICU between 2016 and 2018. AKI was defined and staged using pROCK criteria, which were compared with KDIGO criteria. AKI outcomes, including mortality, daily cost and length of stay (LOS), were assessed. Risk factors for AKI were also estimated.

RESULTS

The incidence of AKI in the PICU was 7.7% according to pROCK criteria. The characteristics of patients with KDIGO-defined AKI who did not meet the pROCK were similar to those without AKI. pROCK outperformed KDIGO in predicting mortality with a higher c index in the Cox models (0.81 versus 0.79, P = 0.013). AKI, as well as AKI stages, were associated with higher mortality (HR: 10.5, 95%CI: 6.66-19.5), daily cost (β = 2064, P < 0.01) and LOS (β = 2.30, P < 0.01). Age, comorbidities, mechanical ventilation (MV), pediatric critical illness score (PCIS) and exposure to drugs had significant influence on AKI occurrence.

CONCLUSIONS

The mortality predictability of pROCK was slightly greater than that of KDIGO. Older age, underlying comorbidities, MV, decreased PCIS and exposure to drugs were potential risk factors for AKI.

IMPACT

Two AKI criteria, pROCK and KDIGO, were significantly associated with an increased risk of mortality and pROCK was slightly greater than that of KDIGO. Older age, comorbidities, mechanical ventilation, decreased PCIS and exposure to drugs were potential risk factors for AKI. This study first used the pROCK criteria to provide an epidemiologic description of pediatric AKI in Chinese PICU. This study compared the AKI outcomes across the pROCK and KDIGO AKI criteria, indicating the prior utility for AKI classification in Chinese children. This study indicated that the potential risk factors for AKI were older age, comorbidities, mechanical ventilation, decreased PCIS and exposure to drugs.

Prediction of sepsis mortality using metabolite biomarkers in the blood: a meta-analysis of death-related pathways and prospective validation

BACKGROUND

Sepsis is a leading cause of death in intensive care units (ICUs), but outcomes of individual patients are difficult to predict. The recently developed clinical metabolomics has been recognized as a promising tool in the clinical practice of critical illness. The objective of this study was to identify the unique metabolic biomarkers and their pathways in the blood of sepsis nonsurvivors and to assess the prognostic value of these pathways.

METHODS

We searched PubMed, EMBASE, Cochrane, Web of Science, CNKI, Wangfang Data, and CQVIP from inception until July 2019. Eligible studies included the metabolomic analysis of blood samples from sepsis patients with the outcome. The metabolic pathway was assigned to each metabolite biomarker. The meta-analysis was performed using the pooled fold changes, area under the receiver operating characteristic curve (AUROC), and vote-counting of metabolic pathways. We also conducted a prospective cohort metabolomic study to validate the findings of our meta-analysis.

RESULTS

The meta-analysis included 21 cohorts reported in 16 studies with 2509 metabolite comparisons in the blood of 1287 individuals. We found highly limited overlap of the reported metabolite biomarkers across studies. However, these metabolites were enriched in several death-related metabolic pathways (DRMPs) including amino acids, mitochondrial metabolism, eicosanoids, and lysophospholipids. Prediction of sepsis death using DRMPs yielded a pooled AUROC of 0.81 (95% CI 0.76-0.87), which was similar to the combined metabolite biomarkers with a merged AUROC of 0.82 (95% CI 0.78-0.86) (P > 0.05). A prospective metabolomic analysis of 188 sepsis patients (134 survivors and 54 nonsurvivors) using the metabolites from DRMPs produced an AUROC of 0.88 (95% CI 0.78-0.97). The sensitivity and specificity for the prediction of sepsis death were 80.4% (95% CI 66.9-89.4%) and 78.8% (95% CI 62.3-89.3%), respectively.

CONCLUSIONS

DRMP analysis minimizes the discrepancies of results obtained from different metabolomic methods and is more practical than blood metabolite biomarkers for sepsis mortality prediction.

TRIAL REGISTRATION

The meta-analysis was registered on OSF Registries, and the prospective cohort study was registered on the Chinese Clinical Trial Registry (ChiCTR1800015321).

A nephron model for study of drug-induced acute kidney injury and assessment of drug-induced nephrotoxicity

In this study, we developed a multilayer microfluidic device to simulate nephron, which was formed by "glomerulus", "Bowman's capsule", "proximal tubular lumen" and "peritubular capillary". In this microdevice, artificial renal blood flow was circulating and glomerular filtrate flow was single passing through, mimicking the behavior of a nephron. In this dynamic artificial nephron, we observed typical renal physiology, including the glomerular size-selective barrier, glomerular basement membrane charge-selective barrier, glucose reabsorption and para-aminohippuric acid secretion. To demonstrate the capability of our microdevice, we used it to investigate the pathophysiology of drug-induced acute kidney injury (AKI) and give assessment of drug-induced nephrotoxicity, with cisplatin and doxorubicin as model drugs. In the experiment, we loaded the doxorubicin or cisplatin in the "renal blood flow", recorded the injury of primary glomerular endothelial cells, podocytes, tubular epithelial cells and peritubular endothelial cells by fluorescence imaging, and identified the time-dependence, dose-dependence and the death order of four types of renal cells. Then by measuring multiple biomarkers, including E-cadherin, VEGF, VCAM-1, Nephrin, and ZO-1, we studied the mechanism of cell injuries caused by doxorubicin or cisplatin. Also, we investigated the effect of BSA in the "renal blood flow" on doxorubicin-or-cisplatin-induced nephrotoxicity, and found that BSA enhanced the tight junctions between cells and eased cisplatin-induced nephrotoxicity. In addition, we compared the nephron model and traditional tubule models for assessment of drug-induced nephrotoxicity. And it can be inferred that our biomimetic microdevice simulated the complex, dynamic microenvironment of nephron, yielded abundant information about drug-induced-AKI at the preclinical stage, boosted the drug safety evaluation, and provided a reliable reference for clinical therapy.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.

Erythropoietin attenuates acute kidney dysfunction in murine experimental sepsis by activation of the β-common receptor

The β-common receptor (βcR) plays a pivotal role in the nonhematopoietic tissue-protective effects of erythropoietin (EPO). Here we determined whether EPO reduces the acute kidney injury (AKI) caused by sepsis and whether this effect is mediated by the βcR. In young (2 months old) C57BL/6 wild-type and βcR knockout mice, lipopolysaccharide caused a significant increase in serum urea and creatinine, hence AKI. This AKI was not associated with any overt morphological alterations in the kidney and was attenuated by EPO given 1 h after lipopolysaccharide in wild-type but not in βcR knockout mice. In the kidneys of endotoxemic wild-type mice, EPO enhanced the phosphorylation of Akt, glycogen synthase kinase-3β, and endothelial nitric oxide synthase, and inhibited the activation of nuclear factor-κB. All these effects of EPO were lost in βcR knockout mice. Since sepsis is more severe in older animals or patients, we tested whether EPO was renoprotective in 8-month-old wild-type and βcR knockout mice that underwent cecal ligation and puncture. These older mice developed AKI at 24 h, which was attenuated by EPO treatment 1 h post cecal ligation and puncture in wild-type mice but not in βcR knockout mice. Thus, activation of the βcR by EPO is essential for the observed reduction in AKI in either endotoxemic young mice or older mice with polymicrobial sepsis, and for the activation of well-known signaling pathways by EPO.