Human Peripheral Blood Mononuclear Cells Incubated in Vasculogenic Conditioning Medium Dramatically Improve Ischemia/Reperfusion Acute Kidney Injury in Mice.

Acute kidney injury (AKI) is a major clinical problem that still has no established treatment. We investigated the efficacy of cultured human peripheral blood mononuclear cells (PBMNCs) for AKI. Ischemia/reperfusion injury (IRI) was used to induce AKI in male nonobese diabetic (NOD/severe combined immunodeficiency) mice aged 7 to 8 wk. PBMNCs were isolated from healthy volunteers and were subjected to quality and quantity controlled (QQc) culture for 7 d in medium containing stem cell factor, thrombopoietin, Flt-3 ligand, vascular endothelial growth factor, and interleukin 6. IRI-induced mice were divided into 3 groups and administered (1) 1 × 106 PBMNCs after QQc culture (QQc PBMNCs group), (2) 1 × 106 PBMNCs without QQc culture (non-QQc PBMNCs group), or (3) vehicle without PBMNCs (IRI control group). PBMNCs were injected via the tail vein 24 h after induction of IRI, followed by assessment of renal function, histological changes, and homing of injected cells. Blood urea nitrogen and serum creatinine (Cr) 72 h after induction of IRI in the QQc PBMNCs group dramatically improved compared with those in the IRI control and the non-QQc PBMNCs groups, accompanied by the improvement of tubular damages. Interstitial fibrosis 14 d after induction of IRI was also significantly improved in the QQc PBMNCs group compared with the other groups. The renoprotective effect noted in the QQc PBMNCs group was accompanied by reduction of peritubular capillary loss. The change of PBMNCs' population (increase of CD34+ cells, CD133+ cells, and CD206+ cells) and increased endothelial progenitor cell colony-forming potential by QQc culture might be one of the beneficial mechanisms for restoring AKI. In conclusion, an injection of human QQc PBMNCs 24 h after induction of IRI dramatically improved AKI in mice.

Modest Impact of Serial Measurements of Acute Kidney Injury Biomarkers in an Adult Intensive Care Unit.

BACKGROUND/AIMS: Acute kidney injury (AKI) biomarkers have been developed with the aim of being able to detect kidney damage earlier than the detection process based on serum creatinine levels. However, single time-point measurements appear to furnish insufficient information for detecting and predicting AKI in intensive care unit patients who are frequently affected by multiple and transient/persistent renal insults. We evaluated whether serial measurements enable the prediction of AKI outcomes in such patients. METHODS: Serial measurements of AKI biomarkers, including plasma and urinary neutrophil gelatinase-associated lipocalin, urinary L-type fatty acid-binding protein, and urinary N-acethyl-ß-D-glucosaminidase, at intensive care unit (ICU) admission (d1) and 24 h later (d2) were performed for critically ill adult patients in a mixed ICU. We assessed whether each biomarker could predict newly developed AKI, recovery from AKI, worsening of AKI, and hospital mortality. RESULTS: Among the enrolled 272 patients, 33 were determined to show newly developed AKI after ICU admission, 58 showed worsening of AKI, 57 recovered from AKI, and 38 died in the hospital. ROC analysis showed that biomarkers at day 2 provided no significant additional benefit in predicting the above-mentioned AKI outcomes compared with those at day 1. However, net reclassification improvement analysis demonstrated that adding day 2 biomarkers to the clinical model comprising clinical variables along with day 1 biomarkers significantly improved the prediction of these AKI outcomes. CONCLUSION: Serial measurement of AKI biomarkers used in clinical models could contribute to the prediction of AKI outcomes in a heterogeneous cohort of adult mixed ICU patients, although its reliability seemed to be modest.

Curcumin inhibits adipogenesis induced by benzyl butyl phthalate in 3T3-L1 cells.

Phthalates are a group of endocrine disrupting chemicals and may have contributed to the recent global obesity health crisis. Increased adipogenesis via the peroxisome proliferator-activated receptor γ (PPARγ)-CCAAT-enhancer binding protein α (C/EBPα) pathway could be one critical mechanism responsible for phthalate-induced weight gain. On the other hand, curcumin has been shown to inhibit adipogenesis in cells and animal models. The present study was undertaken to evaluate, for the first time, whether curcumin could reduce adipogenesis induced by benzyl butyl phthalate (BBP) via downregulation of the PPARγ-C/EBPα pathway. 3T3-L1 preadipocytes were differentiated by treating them with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine in the presence of BBP, with or without curcumin. Cells that were grown in the presence of BBP alone showed a significant increase in triacylglycerol (TG) levels. In addition, the number of Oil Red O-stained cells and the mRNA expression levels of PPARγ, C/EBPα, adiponectin, and tumor necrosis factor-α (TNFα) were significantly increased. However, treatment with BBP in combination with curcumin resulted in major reductions in TG levels, the numbers of Oil Red O-stained cells, and the mRNA expression levels of the four proteins. These results suggest that curcumin might be an inhibitor of BBP-induced weight gain and inflammation via stimulation of adipocyte differentiation and TNFα generation. Curcumin may, therefore, be a potential medication for preventing the harmful effects of phthalates.

Impact of clinical context on acute kidney injury biomarker performances: differences between neutrophil gelatinase-associated lipocalin and L-type fatty acid-binding protein.

Application of acute kidney injury (AKI) biomarkers with consideration of nonrenal conditions and systemic severity has not been sufficiently determined. Herein, urinary neutrophil gelatinase-associated lipocalin (NGAL), L-type fatty acid-binding protein (L-FABP) and nonrenal disorders, including inflammation, hypoperfusion and liver dysfunction, were evaluated in 249 critically ill patients treated at our intensive care unit. Distinct characteristics of NGAL and L-FABP were revealed using principal component analysis: NGAL showed linear correlations with inflammatory markers (white blood cell count and C-reactive protein), whereas L-FABP showed linear correlations with hypoperfusion and hepatic injury markers (lactate, liver transaminases and bilirubin). We thus developed a new algorithm by combining urinary NGAL and L-FABP with stratification by the Acute Physiology and Chronic Health Evaluation score, presence of sepsis and blood lactate levels to improve their AKI predictive performance, which showed a significantly better area under the receiver operating characteristic curve [AUC-ROC 0.940; 95% confidential interval (CI) 0.793-0.985] than that under NGAL alone (AUC-ROC 0.858, 95% CI 0.741-0.927, P = 0.03) or L-FABP alone (AUC-ROC 0.837, 95% CI 0.697-0.920, P = 0.007) and indicated that nonrenal conditions and systemic severity should be considered for improved AKI prediction by NGAL and L-FABP as biomarkers.

Successful Long-term Graft Survival of a Renal Transplantation Patient with Wiskott-Aldrich Syndrome.

Wiskott-Aldrich syndrome, a rare X-linked hereditary syndrome, is characterized by immunodeficiency, thrombocytopenia, and eczema. The underlying T-cell defect renders renal transplantation and immunosuppressive treatments uncertain. The present case exhibited the mild clinical manifestation, regarded as X-linked thrombocytopenia. He successfully underwent a living-donor ABO-compatible renal transplantation and splenectomy in 2002, and thereafter experiencing no severe rejection, serious infection, or malignancy for more than 10 years. Though IgA nephropathy was detected 8 months after transplantation, the patient's renal function and proteinuria were stable without any treatment. The present case showed a successful long-term graft survival and the importance of splenectomy added to renal transplantation.

Association of Urinary Neutrophil Gelatinase-Associated Lipocalin With Long-Term Renal Outcomes in ICU Survivors: A Retrospective Observational Cohort Study.

BACKGROUND: Epidemiological studies recently suggested that acute kidney injury (AKI) in intensive care units (ICUs) increases the risk of chronic kidney disease development and progression. However, whether any AKI biomarker can predict long-term renal outcomes in ICU survivors remains unclear. This study was undertaken to elucidate the role of urinary biomarkers for long-term renal outcome prediction after ICU discharge. METHODS: This retrospective observational study examined 495 adult patients who had been admitted to the ICU of the University of Tokyo Hospital. Major adverse kidney events (MAKE): death, incident end-stage renal disease (ESRD), and halving of estimated glomerular filtration rate (eGFR), at hospital discharge and long-term renal outcomes of 30% reduction of eGFR or incident ESRD were evaluated. RESULTS: Among all the enrolled 495 patients, 393 patients were discharged from the hospital without MAKE. Data of eGFR up to two years after ICU discharge were available for 173 patients; 63 patients (36.4%) were positive for long-term renal outcomes. Step-wise logistic regression analysis demonstrated that male sex and urinary neutrophil gelatinase-associated lipocalin (NGAL) measured at ICU admission showed significant associations with long-term renal outcomes. Receiver operating characteristic curve analysis showed the area under the curve of 0.66 (95% confidence interval 0.57-0.74) for prediction of long-term renal outcome by urinary NGAL. CONCLUSION: Urinary NGAL measured at ICU admission was significantly associated with long-term renal outcomes after hospital discharge in MAKE-free ICU survivors. Urinary NGAL measurements at ICU might be useful to identify a high risk population of kidney disease progression after intensive care.

Regulation of Mitochondrial Dynamics by Dynamin-Related Protein-1 in Acute Cardiorenal Syndrome.

Experimental evidence has clarified distant organ dysfunctions induced by AKI. Crosstalk between the kidney and heart, which has been recognized recently as cardiorenal syndrome, appears to have an important role in clinical settings, but the mechanisms by which AKI causes cardiac injury remain poorly understood. Both the kidney and heart are highly energy-demanding organs that are rich in mitochondria. Therefore, we investigated the role of mitochondrial dynamics in kidney-heart organ crosstalk. Renal ischemia reperfusion (IR) injury was induced by bilateral renal artery clamping for 30 min in 8-week-old male C57BL/6 mice. Electron microscopy showed a significant increase of mitochondrial fragmentation in the heart at 24 h. Cardiomyocyte apoptosis and cardiac dysfunction, evaluated by echocardiography, were observed at 72 h. Among the mitochondrial dynamics regulating molecules, dynamin-related protein 1 (Drp1), which regulates fission, and mitofusin 1, mitofusin 2, and optic atrophy 1, which regulate fusion, only Drp1 was increased in the mitochondrial fraction of the heart. A Drp1 inhibitor, mdivi-1, administered before IR decreased mitochondrial fragmentation and cardiomyocyte apoptosis significantly and improved cardiac dysfunction induced by renal IR. This study showed that renal IR injury induced fragmentation of mitochondria in a fission-dominant manner with Drp1 activation and subsequent cardiomyocyte apoptosis in the heart. Furthermore, cardiac dysfunction induced by renal IR was improved by Drp1 inhibition. These data suggest that mitochondrial fragmentation by fission machinery may be a new therapeutic target in cardiac dysfunction induced by AKI.

Mortality prediction by acute kidney injury biomarkers in comparison with serum creatinine.

OBJECTIVES: To investigate the performance of acute kidney injury (AKI) biomarkers for mortality prediction. MATERIALS AND METHODS: Cutoff values of urinary L-type fatty acid-binding protein (L-FABP) and N-acetyl-ß-d-glucosaminidase (NAG) for AKI diagnosis in ICU were determined in the derivation cohort. The performance of these AKI biomarkers for mortality prediction was evaluated in the validation cohort with stratification of serum-creatinine based AKI diagnosis. RESULTS: Mortality in the AKI patients diagnosed by serum creatinine was increased remarkably when urinary L-FABP and NAG were positive. CONCLUSIONS: These AKI biomarkers can specifically detect high-risk patients among creatinine-base diagnosed AKI.

Perioperative plasma neutrophil gelatinase-associated lipocalin measurement in patients who undergo left ventricular assist device implantation surgery.

BACKGROUND: Perioperative complication of end-organ injury including acute kidney injury (AKI) is a frequent and severe problem for patients undergoing left ventricular assist device (LVAD) implantation. This study evaluated an emerging AKI biomarker, plasma neutrophil gelatinase-associated lipocalin (NGAL), in a LVAD implantation cohort. METHODS AND RESULTS: Of 31 LVAD implantation patients enrolled to this study, 17 (55%) patients were diagnosed as having AKI. Six AKI patients showed severe AKI requiring renal replacement therapy (RRT). Plasma NGAL values in the AKI-with-RRT group (n=6) were significantly higher than that in other patients, although the AKI-without-RRT (n=11) group showed a similar level of plasma NGAL to that of the non-AKI group (n=14). Multiple logistic regression analysis revealed that plasma NGAL measured at pre-operation and central venous pressure at pre-operation and 12 h after surgery independently discriminated against postoperative RRT requirement. In the AKI-with-RRT group, plasma NGAL decreased before termination of RRT in 4 patients who eventually showed renal recovery, although no decline of plasma NGAL was observed in 2 patients who showed no recovery of renal function. Removal of blood NGAL by continuous hemodiafiltration was shown to be 70-75% lower than that of creatinine. CONCLUSIONS: Measurement of perioperative plasma NGAL is useful for predicting severe AKI requiring RRT and renal recovery in patients who have had LVAD implantation surgery. Further investigation is necessary to confirm these findings because this study examined a low number of patients.

The high-mobility group protein B1-Toll-like receptor 4 pathway contributes to the acute lung injury induced by bilateral nephrectomy.

Acute lung injury and acute kidney injury are severe complications in critically ill patients and synergistically increase mortality in intensive care units. Organ cross-talk between the kidney and the lung has been implicated recently as amplifying injury in each organ. Here we sought to identify a possible mechanism of acute kidney injury-induced acute lung injury using a mouse bilateral nephrectomy model. Toll-like receptor 4 (TLR4)-mutant C3H/HeJ mice were more resistant to lung injury including neutrophil infiltration, increased neutrophil elastase activity, and vascular permeability caused by bilateral nephrectomy compared with TLR4-wild-type C3H/HeN mice 6 h after surgery. High-mobility group protein B1 (HMGB1) is one agonist for TLR4. Its blood concentrations were increased significantly by bilateral nephrectomy. Blockade of HMGB1 by neutralizing antibody reduced neutrophil infiltration in TLR4-wild-type C3H/HeN but not in TLR4-mutant C3H/HeJ mice. However, HMGB1 blockade in a renal ischemia reperfusion model reduced pulmonary neutrophil infiltration independent from TLR4. Thus, an enhanced HMGB1-TLR4 pathway contributes to lung injury induced by bilateral nephrectomy and the other HMGB1-dependent pathway exists in pulmonary neutrophil infiltration caused by renal ischemia reperfusion. Targeting the HMGB1-TLR4 pathway might enable development of a new therapeutic strategy to improve the outcomes of severely ill patients with both acute lung and acute kidney injury.

The involvement of mitogen-activated protein kinases in the 1α,25-dihydroxy-cholecalciferol-induced inhibition of adipocyte differentiation in vitro.

The present study was undertaken to investigate the mechanism by which 1α, 25-dihydroxy-cholecalciferol [1α,25-(OH)2-VD3] modulates the differentiation of mouse 3T3-L1 preadipocytes into mature adipocytes. Treatment with 1α,25-(OH)2-VD3 in the presence of insulin, dexamethasone and 3-isobutyl-1-methyl-xanthine significantly inhibited the triacylglycerol accumulation, and mRNA expressions of adipocytokines (adiponectin and tumor necrosis factor-α) and plasminogen activator inhibitor-1 in the pico-nanomolar concentration range, indicating that 1α,25-(OH)2-VD3 under physiological conditions inhibits the differentiation of 3T3-L1 cells. 1α,25-(OH)2-VD3 potently reduced the mRNA and/or protein expressions of CCAAT-enhancer binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), and the nuclear translocation of PPARγ. Furthermore, it inhibited the mRNA expression and phosphorylation of extracellular signal-regulated kinase (ERK), one of mitogen-activated protein kinases. These results indicate that 1α,25-(OH)2-VD3 can be an inhibitor of adipocyte differentiation, and suggest, in addition to C/EBPα and PPARγ, an important role of ERK in mediating 1α,25-(OH)2-VD3-induced alteration in adipocyte differentiation.