651
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Geng H, Lan R, Wang G, Siddiqi AR, Naski MC, Brooks AI, Barnes JL, Saikumar P, Weinberg JM, Venkatachalam MA. Inhibition of autoregulated TGFbeta signaling simultaneously enhances proliferation and differentiation of kidney epithelium and promotes repair following renal ischemia. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:1291-308. [PMID: 19342372 DOI: 10.2353/ajpath.2009.080295] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We studied autocrine transforming growth factor (TGF)beta signaling in kidney epithelium. Cultured proximal tubule cells showed regulated signaling that was high during log-phase growth, low during contact-inhibited differentiation, and rapidly increased during regeneration of wounded epithelium. Autoregulation of signaling correlated with TGFbeta receptor and Smad7 levels, but not with active TGFbeta, which was barely measurable in the growth medium. Confluent differentiated cells with low receptor and high Smad7 levels exhibited blunted responses to saturating concentrations of exogenously provided active TGFbeta, suggesting that TGFbeta signaling homeostasis was achieved by cell density-dependent modulation of signaling intermediates. Antagonism of Alk5 kinase, the TGFbeta type I receptor, dramatically accelerated the induction of differentiation in sparse, proliferating cultures and permitted better retention of differentiated features in regenerating cells of wounded, confluent cultures. Alk5 antagonism accelerated the differentiation of cells in proximal tubule primary cultures while simultaneously increasing their proliferation. Consequently, Alk5-inhibited primary cultures formed confluent, differentiated monolayers faster than untreated cultures. Furthermore, treatment with an Alk5 antagonist promoted kidney repair reflected by increased tubule differentiation and decreased tubulo-interstitial pathology during the recovery phase following ischemic injury in vivo. Our results show that autocrine TGFbeta signaling in proliferating proximal tubule cells exceeds the levels that are necessary for physiological regeneration. To that end, TGFbeta signaling is redundant and maladaptive during tubule repair by epithelial regeneration.
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Affiliation(s)
- Hui Geng
- Department of Pathology, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
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652
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Brooks C, Wei Q, Cho SG, Dong Z. Regulation of mitochondrial dynamics in acute kidney injury in cell culture and rodent models. J Clin Invest 2009; 119:1275-85. [PMID: 19349686 DOI: 10.1172/jci37829] [Citation(s) in RCA: 583] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 02/18/2009] [Indexed: 12/22/2022] Open
Abstract
The mechanism of mitochondrial damage, a key contributor to renal tubular cell death during acute kidney injury, remains largely unknown. Here, we have demonstrated a striking morphological change of mitochondria in experimental models of renal ischemia/reperfusion and cisplatin-induced nephrotoxicity. This change contributed to mitochondrial outer membrane permeabilization, release of apoptogenic factors, and consequent apoptosis. Following either ATP depletion or cisplatin treatment of rat renal tubular cells, mitochondrial fragmentation was observed prior to cytochrome c release and apoptosis. This mitochondrial fragmentation was inhibited by Bcl2 but not by caspase inhibitors. Dynamin-related protein 1 (Drp1), a critical mitochondrial fission protein, translocated to mitochondria early during tubular cell injury, and both siRNA knockdown of Drp1 and expression of a dominant-negative Drp1 attenuated mitochondrial fragmentation, cytochrome c release, caspase activation, and apoptosis. Further in vivo analysis revealed that mitochondrial fragmentation also occurred in proximal tubular cells in mice during renal ischemia/reperfusion and cisplatin-induced nephrotoxicity. Notably, both tubular cell apoptosis and acute kidney injury were attenuated by mdivi-1, a newly identified pharmacological inhibitor of Drp1. This study demonstrates a rapid regulation of mitochondrial dynamics during acute kidney injury and identifies mitochondrial fragmentation as what we believe to be a novel mechanism contributing to mitochondrial damage and apoptosis in vivo in mouse models of disease.
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Affiliation(s)
- Craig Brooks
- Department of Cellular Biology and Anatomy, Medical College of Georgia, and Charlie Norwood VA Medical Center, Augusta, 30912, USA
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653
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Schenk AD, Rosenblum JM, Fairchild RL. Chemokine-directed strategies to attenuate allograft rejection. Clin Lab Med 2009; 28:441-54, vii. [PMID: 19028262 DOI: 10.1016/j.cll.2008.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A key event during T cell-mediated rejection of allografts is the trafficking of donor antigen-primed effector T cells from the lymphoid tissue to the graft. This trafficking is mediated in part by chemokine produced in the graftengaging receptors on the T cells and other graftinfiltrating leukocytes. The presence of specific sets of chemokines and chemokine receptors is detectable in rejecting allografts. In animal models, allograft rejection is delayed when chemokine-chemokine receptor function is absent or antagonized but cellular infiltration and graft survival eventually occur, suggesting that T cells and other leukocytes use several trafficking mechanisms during rejection. The use of chemokines as footprints of rejection may be of considerable value as noninvasive biomarkers in transplantation.
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Affiliation(s)
- Austin D Schenk
- NB3-59, Department of Immunology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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654
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Lee SJ, Kwon CH, Kim YK. Alterations in membrane transport function and cell viability induced by ATP depletion in primary cultured rabbit renal proximal tubular cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:15-22. [PMID: 19885021 DOI: 10.4196/kjpp.2009.13.1.15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide (KCN)/0.1 mM iodoacetic acid (IAA), and membrane transport function and cell viability were evaluated by measuring Na(+)-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in Na(+)-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited Na(+)-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a Na(+) pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in Na(+)-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers (dimethylthiourea and thiourea), and amino acids (glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase A(2) (cPLA(2)). The ATP depletion-dependent arachidonic acid release was inhibited by cPLA(2) specific inhibitor AACOCF(3). ATP depletion-induced alterations in Na(+)-dependent phosphate uptake and cell viability were prevented by AACOCF(3). Inhibition of Na(+)-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and cPLA(2) activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.
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Affiliation(s)
- Sung Ju Lee
- Department of Physiology, MRC for Ischemic Tissue Regeneration, College of Medicine, Pusan National University, Busan 602-739, Korea
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655
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Stroo I, Stokman G, Teske GJD, Florquin S, Leemans JC. Haematopoietic stem cell migration to the ischemic damaged kidney is not altered by manipulating the SDF-1/CXCR4-axis. Nephrol Dial Transplant 2009; 24:2082-8. [PMID: 19223274 PMCID: PMC2698094 DOI: 10.1093/ndt/gfp050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background. Haematopoietic stem cells (HSC) have been shown to migrate to the ischemic kidney. The factors that regulate the trafficking of HSC to the ischemic damaged kidney are not fully understood. The stromal cell-derived factor-1 (SDF-1)/CXCR4-axis has been identified as the central signalling axis regulating trafficking of HSC to the bone marrow. Therefore, we hypothesized that SDF-1/CXCR4 interactions are implicated in the migration of HSC to the injured kidney. Methods. HSC were isolated from mouse bone marrow and labelled with a cell tracker. Acceptor mice were subjected to unilateral ischemia and received HSC intravenously directly after reperfusion. In addition, in separate groups of acceptor mice, endogenous SDF-1 or HSC-associated CXCR4 was blocked or kidneys were injected with SDF-1. Results. Exogenous HSC could be detected in the tubules and interstitium of the kidney 24 h after ischemic injury. Importantly, the amount of HSC in the ischemic kidney was markedly higher compared to the contralateral kidney. Neutralizing endogenous SDF-1 or HSC-associated CXCR4 did not prevent the migration of HSC. No increase in the number of labelled HSC could be observed after local administration of SDF-1, as was also determined in bilateral kidney ischemia. Conclusion. In conclusion, systemically administered HSC preferentially migrate to the ischemic injured kidney. This migration could not be prevented by blocking the SDF-1/CXCR4-axis or increased after local administration of SDF-1.
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Affiliation(s)
- Ingrid Stroo
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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656
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A prospective, multicenter derivation of a biomarker panel to assess risk of organ dysfunction, shock, and death in emergency department patients with suspected sepsis. Crit Care Med 2009; 37:96-104. [PMID: 19050610 DOI: 10.1097/ccm.0b013e318192fd9d] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To define a biomarker panel to predict organ dysfunction, shock, and in-hospital mortality in emergency department (ED) patients with suspected sepsis. DESIGN Prospective observational study. SETTING EDs of ten academic medical centers. PATIENTS There were 971 patients enrolled. INCLUSION CRITERIA 1) ED patients age > 18; 2) suspected infection or a serum lactate level > 2.5 mmol/L; and 3) two or more systemic inflammatory response syndrome criteria. EXCLUSION CRITERIA pregnancy, do-not-resuscitate status, or cardiac arrest. MEASUREMENTS AND MAIN RESULTS Nine biomarkers were assayed from blood draws obtained on ED presentation. Multivariable logistic regression was used to identify an optimal combination of biomarkers to create a panel. The derived formula for weighting biomarker values was used to calculate a "sepsis score," which was the predicted probability of the primary outcome of severe sepsis (sepsis plus organ dysfunction) within 72 hrs. We also assessed the ability of the sepsis score to predict secondary outcome measures of septic shock within 72 hrs and in-hospital mortality. The overall rates of each outcome were severe sepsis, 52%; septic shock, 39%; and in-hospital mortality 7%. Among the nine biomarkers tested, the optimal 3-marker panel was neutrophil gelatinase-associated lipocalin, protein C, and interleukin-1 receptor antagonist. The area under the curve for the accuracy of the sepsis score derived from these three biomarkers was 0.80 for severe sepsis, 0.77 for septic shock, and 0.79 for death. When included in multivariate models with clinical variables, the sepsis score remained highly significant (p < 0.001) for all the three outcomes. CONCLUSIONS A biomarker panel of neutrophil gelatinase-associated lipocalin, interleukin-1ra, and Protein C was predictive of severe sepsis, septic shock, and death in ED patients with suspected sepsis. Further study is warranted to prospectively validate the clinical utility of these biomarkers and the sepsis score in risk-stratifying patients with suspected sepsis.
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657
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Zhuang S, Lu B, Daubert RA, Chavin KD, Wang L, Schnellmann RG. Suramin promotes recovery from renal ischemia/reperfusion injury in mice. Kidney Int 2009; 75:304-11. [DOI: 10.1038/ki.2008.506] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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658
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Prachasilchai W, Sonoda H, Yokota-Ikeda N, Ito K, Kudo T, Imaizumi K, Ikeda M. The protective effect of a newly developed molecular chaperone-inducer against mouse ischemic acute kidney injury. J Pharmacol Sci 2009; 109:311-4. [PMID: 19179808 DOI: 10.1254/jphs.08272sc] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Activation of the unfolded protein response (UPR) has been suggested to attenuate renal ischemia-reperfusion (I/R) injury. We recently found a compound, namely BIX, that activated the UPR selectively through the activating transcription factor 6 pathway. This study examined the effect of BIX on renal I/R injury in mice. BIX selectively up-regulated renal BiP mRNA and protein. Pretreatment with BIX significantly ameliorated renal I/R injury. Co-administration of BIX and tunicamycin, a non-selective UPR inducer, provided no additional protection. Our results suggest that the UPR activation by BIX leads to a novel drug therapy against renal I/R injury.
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Affiliation(s)
- Worapat Prachasilchai
- Department of Veterinary Pharmacology, Faculty of Agriculture, University of Miyazaki, Japan
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659
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Xin C, Yulong X, Yu C, Changchun C, Feng Z, Xinwei M. Urine neutrophil gelatinase-associated lipocalin and interleukin-18 predict acute kidney injury after cardiac surgery. Ren Fail 2009; 30:904-13. [PMID: 18925531 DOI: 10.1080/08860220802359089] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND About 30-50% patients develop acute kidney injury (AKI) after cardiac surgery, which is still diagnosed by serum creatinine on clinic. However, the increase of serum creatinine is insensitive and delayed. The aim of this study is to test the hypothesis that neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) are early biomarkers for AKI in patients after cardiac surgery. METHODS Thirty-three cases undergoing cardiac surgery were classified into an AKI group and non-AKI group, according to the AKI definition (> 26.5 micromol/L increase of serum creatinine, more than or equal to 50% increase of serum creatinine within 48 h, or a reduction in urine output < 0.5 mL/Kg per hour for more than six hours). The concentrations of serum NGAL, urine NGAL, and urine IL-18 at different time-points were measured. RESULTS Nine cases (27.27%) developed postoperative AKI, but diagnosis with serum creatinine was 12-48 h postoperation. The concentrations of serum NGAL were not significantly increased postoperation. The concentrations of urine NGAL and IL-18 were significantly increased in the AKI group, which reached the peak at 2-4 h postoperation, and a more significant difference could be seen after correction for urine creatinine. The concentrations of urine NGAL and IL-18 2 h postoperation, either corrected for urine creatinine or not, showed good sensitivity and specificity. Increased levels of urine NGAL and IL-18 2 h postoperation were significantly correlated with increased level of serum creatinine 12 h postoperation. Logistic regression analysis showed that urine NGAL corrected for urine creatinine 2 h postoperation and urine IL-18 2 h postoperation emerged as powerful independent predictors of AKI after cardiac surgery. CONCLUSIONS The concentrations of urine NGAL and IL-18 could be useful biomarkers for AKI in patients after cardiac surgery, especially after correction for urine creatinine.
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Affiliation(s)
- Chen Xin
- Department of Chest Surgery, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing, China
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660
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Semedo P, Palasio CG, Oliveira CD, Feitoza CQ, Gonçalves GM, Cenedeze MA, Wang PMH, Teixeira VPA, Reis MA, Pacheco-Silva A, Câmara NOS. Early modulation of inflammation by mesenchymal stem cell after acute kidney injury. Int Immunopharmacol 2009; 9:677-82. [PMID: 19146993 DOI: 10.1016/j.intimp.2008.12.008] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 11/17/2008] [Accepted: 12/10/2008] [Indexed: 12/29/2022]
Abstract
Therapy with stem cells has showed to be promising for acute kidney injury (AKI), although how it works is still controversial. Modulation of the inflammatory response is one possible mechanism. Most of published data relies on early time and whether the protection is still maintained after that is not known. Here, we analyzed whether immune modulation continues after 24 h of reperfusion. MSC were obtained from male Wistar rats. After 3-5 passages, cells were screened for CD73, CD90, CD44, CD45, CD29 and CD 31. In addition, MSC were submitted to differentiation in adipocyte and in osteocyte. AKI was induced by bilaterally clamping of renal pedicles for 60 min. Six hours after injury, MSC (2 x 10(5) cells) were administered intravenously. MSC-treated animals presented the lowest serum creatinine compared to non-treated animals (24 h: 1.3+/-0.21 vs. 3.23+/-0.89 mg/dl, p<0.05). The improvement in renal function was followed by a lower expression of IL-1b, IL-6 and TNF-alpha and higher expression of IL-4 and IL-10. However, 48 h after reperfusion, this cytokine profile has changed. The decrease in Th1 cytokines was less evident and IL-6 was markedly up regulated. PCNA analysis showed that regeneration occurs faster in kidney tissues of MSC-treated animals than in controls at 24 h. And also ratio of Bcl-2/Bad was higher at treated animals after 24 and 48 h. Our data demonstrated that the immunomodulatory effects of MSC occur at very early time point, changing the inflammation profile toward a Th2 profile.
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Affiliation(s)
- Patricia Semedo
- Division of Nephrology, Federal University of São Paulo, São Paulo (UNIFESP), Brazil
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661
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Kell DB. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases. BMC Med Genomics 2009; 2:2. [PMID: 19133145 PMCID: PMC2672098 DOI: 10.1186/1755-8794-2-2] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 01/08/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. REVIEW We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here. CONCLUSION Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
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662
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Dezoti C, Watanabe M, Pinto CF, Neiva LBDM, Vattimo MDFF. Proteção funcional da enzima heme-oxigenase-1 na lesão renal aguda isquêmica e tóxica. ACTA PAUL ENFERM 2009. [DOI: 10.1590/s0103-21002009000800006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJETIVOS: Verificar a proteção funcional da heme-oxigenase (HO-1), por meio do uso do seu indutor (Hemin) e seu inibidor químico (protoporfirina de zinco-ZnPP) na lesão renal aguda isquêmica e tóxica pela Polimixina B (PmxB) em ratos. MATERIAL: Foram utilizados ratos Wistar, adultos e machos divididos em 8 grupos: SHAM (controle), Isquemia (Isq), Isq+Hemin (indutor de HO-1), Isq+ZnPP (inibidor de HO-1), SALINA (controle), Polimixina B (PmxB), PmxB+Hemin, PmxB+ZnPP. MÉTODOS: Jaffé (clearance de creatinina, Clcr) e FOX-2 (peróxidos urinários). RESULTADOS: A isquemia (30´) dos pedículos reais e a administração de PmxB reduziu o Clcr com manutenção do fluxo urinário. Os peróxidos urinários se elevaram em ambas as lesões. A administração do Indutor de HO-1 determinou melhora da função renal e redução dos níveis de peróxidos urinários. CONCLUSÃO: Os resultados deste estudo demonstraram que a isquemia e a PmxB induzem LRA oxidativa. O indutor de HO-1 atenuou a lesão em ambos os modelos por atenuação do mecanismo redox.
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663
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Devarajan P. Neutrophil Gelatinase-associated Lipocalin: An Emerging Biomarker for Angina Renalis. Intensive Care Med 2009. [DOI: 10.1007/978-0-387-92278-2_58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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664
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Makris K, Markou N, Evodia E, Dimopoulou E, Drakopoulos I, Ntetsika K, Rizos D, Baltopoulos G, Haliassos A. Urinary neutrophil gelatinase-associated lipocalin (NGAL) as an early marker of acute kidney injury in critically ill multiple trauma patients. Clin Chem Lab Med 2009; 47:79-82. [DOI: 10.1515/cclm.2009.004] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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665
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666
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Grenier N, Hauger O, Eker O, Combe C, Couillaud F, Moonen C. Molecular magnetic resonance imaging of the genitourinary tract: recent results and future directions. Magn Reson Imaging Clin N Am 2008; 16:627-41, viii. [PMID: 18926427 DOI: 10.1016/j.mric.2008.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This article focuses on preclinical and early clinical applications of renal cell MR imaging, on new developments in MR control of intrarenal gene therapy, and on several potential applications of molecular imaging techniques, mainly targeting cell receptors and enzyme activity, which could find exciting applications within the genitourinary tract.
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Affiliation(s)
- Nicolas Grenier
- UMR-CNRS 5231 Imagerie Moléculaire et Fonctionnelle, Université Victor Segalen-Bordeaux 2, Bordeaux-Cedex, France.
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667
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Abstract
Acute kidney injury (AKI) represents a common and devastating problem in clinical medicine. A major reason is the lack of early biomarkers for AKI, and hence an unacceptable delay in initiating therapy. Fortunately, the application of innovative technologies has uncovered several novel biomarkers. The most promising of these are included in a putative AKI biomarker panel, consisting of neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1. These biomarkers have completed initial validation, and have entered the prospective screening stage in the biomarker development process, facilitated by the development of commercial tools for their reproducible measurement across laboratories. The availability of a panel of validated biomarkers will revolutionize renal and critical care, and enable the practice of personalized and predictive medicine at an unprecedented level.
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Affiliation(s)
- Prasad Devarajan
- Departments of Pediatrics and Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA.
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668
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Devarajan P. Neutrophil gelatinase-associated lipocalin--an emerging troponin for kidney injury. Nephrol Dial Transplant 2008; 23:3737-43. [PMID: 18809975 PMCID: PMC2720816 DOI: 10.1093/ndt/gfn531] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 09/01/2008] [Indexed: 11/14/2022] Open
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669
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The role of hypotension in the development of acute renal failure. Nephrol Dial Transplant 2008; 24:337-8. [DOI: 10.1093/ndt/gfn679] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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670
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Lavery AP, Meinzen-Derr JK, Anderson E, Ma Q, Bennett MR, Devarajan P, Schibler KR. Urinary NGAL in premature infants. Pediatr Res 2008; 64:423-8. [PMID: 18552711 DOI: 10.1203/pdr.0b013e318181b3b2] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Premature infants are at unique risk for developing acute kidney injury (AKI) due to incomplete nephrogenesis, early exposure to nephrotoxic medications, and coexisting conditions such as patent ductus arteriosus (PDA) and respiratory distress syndrome (RDS). Unfortunately, laboratory testing for the diagnosis of AKI in this population is problematic because of the physiology of both the placenta and the extra-uterine premature kidney. Recent research has led to the development of promising biomarkers for the early detection of AKI in children but there are no published reports in neonates. Our goal was to determine whether urine neutrophil gelatinase-associated lipocalin (NGAL) was detectable in premature infants and to correlate levels with gestational age, birth weight (BW), or indomethacin exposure. We enrolled 20 infants in four BW groups: 500-750, 751-1000, 1001-1250, and 1251-1500 g. Urine was collected every day for the first 14 d of life. Neonates born at earlier gestational ages and lower BWs had higher urine NGAL levels (p < 0.01). We conclude that urine NGAL is easily obtained in premature infants and that it correlates significantly with both BW and gestational age. The use of urinary NGAL as a biomarker of AKI in premature infants warrants further investigation.
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Affiliation(s)
- Adrian P Lavery
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
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671
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Sutton TA, Wilkinson J, Mang HE, Knipe NL, Plotkin Z, Hosein M, Zak K, Wittenborn J, Dagher PC. p53 regulates renal expression of HIF-1{alpha} and pVHL under physiological conditions and after ischemia-reperfusion injury. Am J Physiol Renal Physiol 2008; 295:F1666-77. [PMID: 18815219 DOI: 10.1152/ajprenal.90304.2008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) and is characterized by widespread tubular and microvascular damage. The tumor suppressor p53 is upregulated after IRI and contributes to renal injury in part by promoting apoptosis. Acute, short-term inhibition of p53 with pifithrin-alpha conveys significant protection after IRI. The hypoxia-inducible factor-1 (HIF-1) pathway is also activated after IRI and has opposing effects to those promoted by p53. The balance between the HIF-1 and p53 responses can determine the outcome of IRI. In this manuscript, we investigate whether p53 regulates the HIF-1 pathway in a rodent model of IRI. HIF-1alpha is principally expressed in the collecting tubules (CT) and thick ascending limbs (TAL) under physiological conditions. However, inhibition of p53 with pifithrin-alpha increases the faint expression of HIF-1alpha in proximal tubules (PT) under physiological conditions. Twenty-four hours after IRI, HIF-1alpha expression is decreased in both CT and TAL. HIF-1alpha expression in the PT is not significantly altered after IRI. Acute inhibition of p53 significantly increases HIF-1alpha expression in the PT after IRI. Additionally, pifithrin-alpha prevents the IRI-induced decrease in HIF-1alpha in the CT and TAL. Parallel changes are observed in the HIF-1alpha transcriptive target, carbonic anhydrase-9. Finally, inhibition of p53 prevents the dramatic changes in Von Hippel-Lindau protein morphology and expression after IRI. We conclude that activation of p53 after IRI mitigates the concomitant activation of the protective HIF-1 pathway. Modulating the interactions between the p53 and HIF-1 pathway can provide novel options in the treatment of AKI.
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Affiliation(s)
- Timothy A Sutton
- Div. of Nephrology, Dept. of Medicine, Indiana Univ. School of Medicine, 950 West Walnut St., R-II, 202, Indianapolis, IN 46202, USA.
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672
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Schmitt R, Marlier A, Cantley LG. Zag expression during aging suppresses proliferation after kidney injury. J Am Soc Nephrol 2008; 19:2375-83. [PMID: 18815245 DOI: 10.1681/asn.2008010035] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Recovery after acute kidney injury is impaired in the elderly, but mechanistic information regarding why this occurs is limited. In this study, aged mouse kidneys displayed a reduced epithelial proliferative reserve in vivo and in vitro. Microarray analysis identified increased expression of zinc-alpha (2)-glycoprotein (Zag) in aged proximal tubular cells. The addition of recombinant Zag to primary renal epithelial cell cultures decreased proliferation, whereas knockdown of Zag increased proliferation. In vivo, systemic small interference RNA suppressed expression of Zag in the mouse proximal tubule; this increased the rate of epithelial cell proliferation after renal ischemia/reperfusion in aged mice but also increased parenchymal fibrosis. These results demonstrate that increased Zag expression in the aged kidney acts to suppress the proliferative response to injury and introduce Zag as a modifier of the aging phenotype.
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Affiliation(s)
- Roland Schmitt
- Section of Nephrology, Department of Medicine, Yale University, New Haven, Connecticut 06510, USA
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673
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Devarajan P. NGAL in acute kidney injury: from serendipity to utility. Am J Kidney Dis 2008; 52:395-9. [PMID: 18725011 DOI: 10.1053/j.ajkd.2008.07.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 07/18/2008] [Indexed: 11/11/2022]
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674
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Leonard EC, Friedrich JL, Basile DP. VEGF-121 preserves renal microvessel structure and ameliorates secondary renal disease following acute kidney injury. Am J Physiol Renal Physiol 2008; 295:F1648-57. [PMID: 18799550 DOI: 10.1152/ajprenal.00099.2008] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute kidney injury induced by renal ischemia-reperfusion (I/R) compromises microvascular density and predisposes to chronic kidney disease (CKD) and sodium-dependent hypertension. VEGF-121 was administered to rats fed a standard (0.4%) sodium diet at various times following recovery from I/R injury for up to 35 days. VEGF-121 had no effect on the initial loss of renal function, as indicated by serum creatinine levels measured 24 h after injury. Serum creatinine levels declined thereafter, indicative of renal repair. Rats were then switched to an elevated (4.0%) sodium diet for an additional 28 days to induce CKD. The 4.0% sodium diet enhanced renal hypertrophy, interstitial volume, albuminuria, and cardiac hypertrophy relative to postischemic animals maintained on the 0.4% sodium diet. Administration of VEGF-121 from day 0 to 14, day 0 to 35, or day 3 to 35 after I/R suppressed the effects of sodium diet on CKD development, while delayed administration of VEGF-121 from day 21 to 35 had no effect. Endothelial nitric oxide synthase protein levels were upregulated in postischemic animals, and this effect was significantly increased by the 4.0% sodium diet but was not influenced by prior treatment with VEGF. Conversely, microvascular density was preserved in postischemic animals treated with VEGF-121 relative to vehicle-treated postischemic animals. These data suggest that early, but not delayed, treatment with VEGF-121 can preserve vascular structure after ischemia and influence chronic renal function in response to elevated sodium intake.
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Affiliation(s)
- Ellen C Leonard
- Dept. of Cellular and Integrative Physiology, Indiana Univ. School of Medicine, 635 Barnhill Dr. MS 334, Indianapolis, IN 46202, USA
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675
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Rubinstein I, Abassi Z, Milman F, Ovcharenko E, Coleman R, Winaver J, Better OS. Hyperbaric oxygen treatment improves GFR in rats with ischaemia/reperfusion renal injury: a possible role for the antioxidant/oxidant balance in the ischaemic kidney. Nephrol Dial Transplant 2008; 24:428-36. [PMID: 18799609 PMCID: PMC2639336 DOI: 10.1093/ndt/gfn511] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Ischaemic kidney injury continues to play a dominant role in the pathogenesis of acute renal failure (ARF) in many surgical and medical settings. A major event in the induction of renal injury is related to the generation of oxygen-free radicals. Hyperbaric oxygen therapy (HBO) is indicated for treatment of many ischaemic events but not for ARF. Therefore, the present study examined the effects of HBO on kidney function and renal haemodynamics in rats with ischaemic ARF. METHODS Renal ischaemia was induced by unilateral renal artery clamping (45 min) in rats. Within 24 h following ischaemia, rats were treated twice with HBO of 100% O(2) at 2.5 absolute atmospheres for 90 min each (+HBO). Untreated rats (-HBO) served as a control. Forty-eight hours later, GFR, RBF and endothelial-dependent vasorelaxation were measured. In addition, the immunoreactive staining of 4-hydroxy-2-noneal (4-HNE), a major product of endogenous lipid peroxidation, and superoxide dismutase (SOD) were assessed. RESULTS In the -HBO group, GFR was reduced by 94% compared with the untouched normal kidney (ischaemic: 0.06 +/- 0.03 ml/min, normal: 1.02 +/- 0.13 ml). In contrast, in the +HBO group, GFR of the ischaemic kidney (0.36 +/- 0.07 ml/min) was reduced only by 68% compared with the contralateral normal kidney (1.12 +/- 0.12 ml/min). In line with these findings, HBO improved the vasodilatory response to ACh as expressed in enhancement of both total and regional renal blood flow. In addition, HBO reduced the formation of 4-HNE by 33% and 76% and increased SOD by 30% and 70% in the cortex and outer stripe region of the medulla of the ischaemic kidney, respectively. CONCLUSION HBO attenuates the decline in GFR following renal ischaemia, and improves endothelial-dependent vasorelaxation, suggesting that treatment with HBO may be beneficial in the setting of ischaemic ARF.
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Affiliation(s)
- Irit Rubinstein
- Department of Physiology, the B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology and Rambam Medical Center, Haifa, 31096, Israel
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676
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Autophagy is cytoprotective during cisplatin injury of renal proximal tubular cells. Kidney Int 2008; 74:631-40. [DOI: 10.1038/ki.2008.214] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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677
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He Z, Lu L, Altmann C, Hoke TS, Ljubanovic D, Jani A, Dinarello CA, Faubel S, Edelstein CL. Interleukin-18 binding protein transgenic mice are protected against ischemic acute kidney injury. Am J Physiol Renal Physiol 2008; 295:F1414-21. [PMID: 18753296 DOI: 10.1152/ajprenal.90288.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
IL-18 function is neutralized in IL-18 binding protein transgenic (IL-18BP Tg) mice. First, we determined whether IL-18BP Tg mice are protected against ischemic acute kidney injury (AKI). Ischemic AKI was induced by bilateral renal pedicle clamping. IL-18BP Tg mice were functionally and histologically protected against ischemic AKI as determined by blood urea nitrogen, serum creatinine, and acute tubular necrosis score. We have demonstrated that the injurious effect of IL-18 in the kidney is independent of neutrophils and lymphocytes. Thus the effect of IL-18 inhibition on renal macrophage infiltration was determined. The number of macrophages was significantly reduced in IL-18BP Tg compared with wild-type kidneys. To determine the cytokines and chemokines that are dependent on IL-18, we performed flow cytometry based assays. Multiple chemokines/cytokines, IL-3, IL-6, IL-15, IL-18, leukemia inhibitory factor, macrophage colony-stimulating factor, macrophage inflammatory protein-2, granulocyte-macrophage colony-stimulating factor, and monocyte chemotactic protein-1 were significantly increased in AKI vs. sham kidneys. Only CXCL1 (also known as KC or IL-8) was significantly increased in AKI vs. sham kidneys and significantly reduced in IL-18BP Tg AKI vs. wild-type AKI kidneys. To determine whether macrophages are the source of CXCL1 in the kidney, we depleted macrophages with liposomal encapsulated clodronate. CXCL1 was significantly decreased in macrophage-depleted vs. control AKI mice. In summary, in ischemic AKI in mice, 1) IL-18BP Tg mice are functionally and histologically protected, 2) macrophage infiltration in the kidney and CXCL1 are significantly reduced in IL-18BP Tg mice, and 3) macrophage depletion significantly reduces CXCL1 in the kidney. In conclusion, protection against ischemic AKI in IL-18BP Tg mice is associated with less macrophage infiltration and less production of CXCL1 in the kidney.
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Affiliation(s)
- Zhibin He
- Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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678
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Urinary aprotinin as a predictor of acute kidney injury after cardiac surgery in children receiving aprotinin therapy. Pediatr Nephrol 2008; 23:1317-26. [PMID: 18506488 DOI: 10.1007/s00467-008-0827-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 02/14/2008] [Accepted: 02/14/2008] [Indexed: 12/24/2022]
Abstract
Proteomic analysis has revealed potential early biomarkers of acute kidney injury (AKI) in children undergoing cardiopulmonary bypass (CPB), the most prominent one with a mass-to-charge ratio of 6.4 kDa. The objective of this study was to identify this protein and test its utility as a biomarker of AKI. Trypsin-digested protein bands were analyzed by tandem mass spectrometry (MS/MS) to identify the protein in urine samples. Surface-enhanced laser desorption/ionization time-of-flight analysis and a functional activity assay were performed to quantify urinary levels in a pilot study of 106 pediatric patients undergoing CPB. The protein was identified as aprotinin. Urinary aprotinin levels 2 h after initiation of CPB were predictive of AKI (for functional assay: 92% sensitivity, 96% specificity, area under the curve of 0.98). By multivariate analysis, the urinary aprotinin level 2 h after CPB was an independent predictor of AKI (beta = 0.001, P < 0.0001). The 2 h urinary aprotinin level correlated with serum creatinine, duration of AKI, and length of hospital stay. We concluded that urinary aprotinin levels 2 h after initiation of CPB predict the development of AKI and adverse clinical outcomes.
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679
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Prachasilchai W, Sonoda H, Yokota-Ikeda N, Oshikawa S, Aikawa C, Uchida K, Ito K, Kudo T, Imaizumi K, Ikeda M. A protective role of unfolded protein response in mouse ischemic acute kidney injury. Eur J Pharmacol 2008; 592:138-45. [PMID: 18644364 DOI: 10.1016/j.ejphar.2008.06.108] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 06/03/2008] [Accepted: 06/27/2008] [Indexed: 10/21/2022]
Abstract
Although renal ischemia-reperfusion is known to activate the unfolded protein response, the renal site and role of activation of this response following the insult in vivo remains largely unknown. Here we studied the renal spatio-temporal expression pattern of glucose-regulated protein (GRP) 78, a central regulator of the unfolded protein response network, following renal ischemia-reperfusion and the effects of the specific chemical unfolded protein response inducers, tunicamycin and thapsigargin, on renal ischemia-reperfusion injury in mice. Renal ischemia-reperfusion resulted in expression of the spliced form of the X-box binding protein-1 (XBP-1s) transcript, an unfolded protein response target, at 1 and 2 h after the insult. This response was followed by an increase in the GRP78 transcript and protein. The increased amount of GRP78 protein after ischemia-reperfusion was largely localized in proximal tubule cells. Pretreatment with tunicamycin or thapsigargin significantly ameliorated renal dysfunction and injury after ischemia-reperfusion. Taken together with these results, the unfolded protein response was activated following renal ischemia-reperfusion at sites that are susceptible to ischemia-reperfusion injury, and this activation had a protective effect against renal ischemia-reperfusion injury in vivo. Molecules involved in the unfolded protein response may offer new opportunities for pharmacological intervention against renal ischemia-reperfusion injury, which is an important cause of acute kidney injury.
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Affiliation(s)
- Worapat Prachasilchai
- Department of Veterinary Pharmacology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
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680
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Abstract
PURPOSE OF REVIEW The paucity of early, predictive, noninvasive biomarkers has impaired our ability to institute potentially effective therapies for acute kidney injury and chronic kidney disease in a timely manner. RECENT FINDINGS Promising novel biomarkers for acute kidney injury include a plasma panel (neutrophil gelatinase-associated lipocalin and cystatin C) and a urine panel (neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1). For chronic kidney disease, these include a similar plasma panel and a urine panel (neutrophil gelatinase-associated lipocalin, asymetric dimethylarginine, and liver-type fatty acid-binding protein). The biomarker panels will probably be useful for assessing the duration and severity of kidney disease, and for predicting progression and adverse clinical outcomes. It is also likely that the biomarker panels will help to distinguish between the various etiologies of acute kidney injury or chronic kidney disease. SUMMARY The tools of functional genomics and proteomics have provided us with promising novel biomarkers for acute kidney injury and chronic kidney disease. It will be important in future studies to validate the sensitivity and specificity of these biomarker panels in clinical samples from large cohorts and in multiple clinical situations. Such studies will be facilitated by the availability of commercial tools for reproducible measurement of these panels.
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681
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Yu SJ, Oh DJ, Yu SH. The investigation of macrophage infiltration in the early phase of ischemic acute renal failure in mice. Korean J Intern Med 2008; 23:64-71. [PMID: 18646508 PMCID: PMC2686976 DOI: 10.3904/kjim.2008.23.2.64] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIMS Inflammation plays a key role in ischemic acute renal failure (ARF). The present study investigated the infiltration of macrophages in the early phase of ischemic ARF in mice. METHODS Ischemic ARF was induced by renal clamping for 22 min, while the control mice underwent sham surgery (no clamping). The serum creatinine and blood urea nitrogen (BUN) levels were measured in the control and post-ischemia mice. Immunofluorescence staining was used to measure the number of CD 11b-positive cells in the kidney tissue sections to determine the amount of post-ischemic macrophage infiltration. Lipo-Cl2MBP (clodronate) for macrophages depletion was injected via a tail vein 5 d before ischemia induction and again 2 d before ischemia induction. RESULTS The study found that the post-ischemia mice had higher levels of serum creatinine and BUN at 16 and 24 h compared to the controls. Immunofluorescence staining showed there were more macrophages in the post-ischemic tissue at 2, 8, 16 and 24 h compared to the control tissue, and that most of these macrophages were located in the outer medulla. The mice treated with clodronate prior to ischemia induction were found to have lower levels of serum creatinine compared to those mice that weren't treated with clodronate. CONCLUSIONS There was significant infiltration of macrophages from the early phase of ischemic ARF, and this peaked at 16-24 h. Macrophage depletion using clodronate was protective against ischemic ARF.
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Affiliation(s)
- Soo-Jeong Yu
- Department of Internal Medicine, Incheon Christian Hospital, Korea
| | - Dong-Jin Oh
- Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Suk-Hee Yu
- Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
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682
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Sharyo S, Yokota-Ikeda N, Mori M, Kumagai K, Uchida K, Ito K, Burne-Taney MJ, Rabb H, Ikeda M. Pravastatin improves renal ischemia-reperfusion injury by inhibiting the mevalonate pathway. Kidney Int 2008; 74:577-84. [PMID: 18509318 DOI: 10.1038/ki.2008.210] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Statins are known to lessen the severity of renal ischemia-reperfusion injury. The present study was undertaken to define the mechanism of renoprotective actions of statins using a mouse kidney injury model. Treatment of mice with pravastatin, a widely used statin, improved renal function after renal ischemia-reperfusion without lowering the plasma cholesterol level. Administration of pravastatin with mevalonate, a product of HMG-CoA reductase, eliminated renal protection suggesting an effect of pravastatin on mevalonate or its metabolism. In hypercholestrolemic apolipoprotein E knockout mice with reduced HMG-CoA reductase activity; the degree of injury was less severe than in control mice, however, there was no protective action of pravastatin on renal injury in the knockout mice. Treatment with a farnesyltransferase inhibitor (L-744832) mimicked pravastatin's protective effect but co-administration with the statin provided no additional protection. Both pravastatin and L-744832 inhibited the injury-induced increase in plasma IL-6 concentration to a similar extent. Our results suggest the protective effect of pravastatin on renal ischemia-reperfusion injury is mediated by inhibition of the mevalonate-isoprenoid pathway independent of its lipid lowering action.
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Affiliation(s)
- Satoru Sharyo
- Department of Veterinary Pharmacology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
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683
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Lewis AG, Köhl G, Ma Q, Devarajan P, Köhl J. Pharmacological targeting of C5a receptors during organ preservation improves kidney graft survival. Clin Exp Immunol 2008; 153:117-26. [PMID: 18505432 DOI: 10.1111/j.1365-2249.2008.03678.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cadaveric renal transplants suffer frequently from delayed graft function, which is associated with increased risk for long-term graft survival loss. One-third of kidney grafts that are stored in current organ preservation solutions experience delayed graft function, demonstrating the urgent need for improvement. Although ischaemic graft injury is complex in nature, complement activation is considered important to the process. Here we show that pharmacological targeting of the complement 5a receptor (C5aR) during cold ischaemia has a protective effect on early kidney graft survival, inflammation and apoptosis in a mouse model of syngeneic kidney transplantation. Graft survival of kidneys that were stored in University of Wisconsin solution in the presence of a C5aR antagonist increased from 29% to 57%. Increased graft survival was associated with less tubular damage and apoptosis, protection from sustained C5aR expression and decreased production of tumour necrosis factor-alpha and macrophage inflammatory protein-2. In a translational approach, we determined C5aR expression in paediatric living-related and cadaveric allografts. C5aR expression was significantly higher in all compartments of kidneys from cadaveric compared with kidneys from living-related donors. C5aR expression in cadaveric kidneys correlated positively with cold ischaemia time, renal dysfunction and the frequency of apoptotic tubular cells, suggesting a novel role for C5a in delayed graft function pathogenesis. Supplementing organ preservation solutions with C5aR inhibitors may improve early graft function following cadaveric kidney transplantation.
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Affiliation(s)
- A G Lewis
- Division of Molecular Immunology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, College of Medicine, Cincinnati, OH 45229, USA
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684
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Interleukin-20 induced cell death in renal epithelial cells and was associated with acute renal failure. Genes Immun 2008; 9:395-404. [PMID: 18496552 DOI: 10.1038/gene.2008.28] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Acute renal failure is an abrupt decrease in renal function. Interleukin (IL)-10 inhibits ischemic and cisplatin-induced acute renal failure. We aimed to determine whether IL-20 affects renal tubular epithelial cells and is associated with acute renal failure. We analyzed the expression of IL-20 and its receptor (R) in the kidneys of rats with HgCl(2)-induced acute renal failure. Reverse transcription-PCR showed upregulated IL-20, and its receptors and immunohistochemical staining showed strongly expressed IL-20 protein in proximal tubular epithelial cells. We analyzed human proximal tubular epithelial (HK-2) cells, which expressed both IL-20 and its receptors. IL-20 specifically induced mitochondria-dependent apoptosis by activating caspase 9 in HK-2 cells. IL-20 also activated c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2, the downstream signals implicated in the apoptosis of HK-2 cells. Furthermore, IL-20 upregulated the transcripts of transforming growth factor (TGF)-beta1, a critical mediator of renal injury. In hypoxic HK-2 cells, IL-20 and IL-22R1 transcripts increased, and IL-20 upregulated IL-1 beta transcripts. In vivo study further demonstrated that anti-IL-20 antibody reduced the expression of TGF-beta1 and IL-1 beta and the number of damaged tubular cells in the kidneys of rats with acute renal failure. We concluded that IL-20 may be involved in the injury of renal epithelial cells in acute renal failure.
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685
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Srichai MB, Hao C, Davis L, Golovin A, Zhao M, Moeckel G, Dunn S, Bulus N, Harris RC, Zent R, Breyer MD. Apoptosis of the thick ascending limb results in acute kidney injury. J Am Soc Nephrol 2008; 19:1538-46. [PMID: 18495962 DOI: 10.1681/asn.2007101101] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Ischemia- or toxin-induced acute kidney injury is generally thought to affect the cells of the proximal tubule, but it has been difficult to define the involvement of other tubular segments because of the widespread damage caused by ischemia/reperfusion or toxin-induced injury in experimental models. For evaluation of whether thick ascending limb (TAL)-specific epithelial injury results in acute kidney injury, a novel transgenic mouse model that expresses the herpes simplex virus 1 thymidine kinase gene under the direction of the TAL-specific Tamm-Horsfall protein promoter was generated. After administration of gancyclovir, these mice demonstrated apoptosis only in TAL cells, with little evidence of neutrophil infiltration. Compared with control mice, blood urea nitrogen and creatinine levels were at least five-fold higher in the transgenic mice, which also developed oliguria and impaired urinary concentrating ability. These findings suggest that acute injury targeted only to the TAL is sufficient to cause severe acute kidney injury in mice with features similar to those observed in humans.
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Affiliation(s)
- Manakan B Srichai
- Veterans Administration Hospital, Department of Medicine/Division of Nephrology, Vanderbilt University, Nashville, TN 37232, USA.
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686
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El-Achkar TM, Wu XR, Rauchman M, McCracken R, Kiefer S, Dagher PC. Tamm-Horsfall protein protects the kidney from ischemic injury by decreasing inflammation and altering TLR4 expression. Am J Physiol Renal Physiol 2008; 295:F534-44. [PMID: 18495803 DOI: 10.1152/ajprenal.00083.2008] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Tamm-Horsfall protein (THP) is a glycoprotein with unclear functions expressed exclusively in thick ascending limbs (TAL) of the kidney. Its role in ischemic acute kidney injury is uncertain, with previous data suggesting a possible negative effect by enhancing cast formation and promoting inflammation. Using a recently characterized THP knockout mouse (THP-/-), we investigated the role of THP in renal ischemia-reperfusion injury (IRI). In wild-type mice (THP+/+), THP expression was increased by injury. THP-/- mice developed more functional and histological renal damage after IRI compared with THP+/+. THP-/- kidneys showed more inflammation and tubular necrosis. Cast formation correlated with the severity of injury and was independent of THP presence. THP absence was associated with a more necrotic, rather than apoptotic, phenotype of cell death. The outer medulla was predominantly affected, where significant interstitial neutrophil infiltration was detected in proximity to injured S3 proximal tubular segments and TAL. This coincided with an enhanced expression of the innate immunity receptor Toll-like receptor 4 (TLR4) in S3 segments of THP-/- compared with THP+/+ mice. Specifically, a basolateral S3 expression of TLR4 was more evident in THP-/- kidneys compared with a more apical distribution in THP+/+. Such basolateral location for TLR4 allows a greater interaction with proinflammatory ligands present in the interstitium during ischemia. In conclusion, we are showing a completely novel role for a very old protein in the setting of renal injury. Our data suggest that THP stabilizes the outer medulla in the face of injury by decreasing inflammation, possibly through an effect on TLR4.
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Affiliation(s)
- Tarek M El-Achkar
- Department of Medicine, Saint Louis University and St. Louis Veterans Affairs Medical Center, St. Louis, MO, USA.
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687
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Abstract
Transcriptome profiling has shown that the pro-apoptotic death-domain-associated protein Daxx is rapidly induced in the kidney of animals following ischemic injury. Here we found that Daxx protein was increased 5-fold in tubule cells in both animal and human models of ischemic acute kidney injury. Further there was upregulation of its primary interacting partner, Fas and phosphorylation of its primary downstream activator (JNK) in parallel to Daxx induction. In cultured tubule cells, partial ATP depletion resulted in a rapid induction of Daxx, Fas, JNK phosphorylation and apoptosis. Antisense oligonucleotides to Daxx and specific JNK inhibitors blunted the apoptotic response to ATP depletion. These studies indicate that Daxx may play an unrecognized role in the early apoptotic response to ischemic renal injury.
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688
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Expression and function of the Delta-1/Notch-2/Hes-1 pathway during experimental acute kidney injury. Kidney Int 2008; 73:1240-50. [PMID: 18418349 DOI: 10.1038/ki.2008.74] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Notch signaling pathway consists of several receptors and their ligands Delta and Jagged and is important for embryogenesis, cellular differentiation and proliferation. Activation of Notch receptors causes their cleavage yielding cytoplastic domains that translocate into the nucleus to induce target proteins such as the basic-loop-helix proteins Hes and Hey. Here we sought to clarify the significance of the Notch signaling pathway in acute kidney injury using a rat ischemia-reperfusion injury model and cultured NRK-52E cells. Analysis of the whole kidney after injury showed increased expression of Delta-1 and Hes-1 mRNA and protein along with processed Notch-2. Confocal microscopy, using specific antibodies, showed that Delta-1, cleaved Notch-2 and Hes-1 colocalized in the same segments of the injured renal proximal tubules. Recombinant Delta-1 significantly stimulated NRK-52E cell proliferation. Our study suggests that the Delta-1/Notch-2/Hes-1 signaling pathway may regulate the regeneration and proliferation of renal tubules during acute kidney injury.
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689
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Dent CL, Ma Q, Dastrala S, Bennett M, Mitsnefes MM, Barasch J, Devarajan P. Plasma neutrophil gelatinase-associated lipocalin predicts acute kidney injury, morbidity and mortality after pediatric cardiac surgery: a prospective uncontrolled cohort study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 11:R127. [PMID: 18070344 PMCID: PMC2246223 DOI: 10.1186/cc6192] [Citation(s) in RCA: 321] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 11/26/2007] [Accepted: 12/10/2007] [Indexed: 12/02/2022]
Abstract
Introduction Acute kidney injury (AKI) is a frequent complication of cardiopulmonary bypass (CPB). The lack of early biomarkers has impaired our ability to intervene in a timely manner. We previously showed in a small cohort of patients that plasma neutrophil gelatinase-associated lipocalin (NGAL), measured using a research enzyme-linked immunosorbent assay, is an early predictive biomarker of AKI after CPB. In this study we tested whether a point-of-care NGAL device can predict AKI after CPB in a larger cohort. Methods First, in a cross-sectional pilot study including 40 plasma samples (NGAL range 60 to 730 ng/ml) and 12 calibration standards (NGAL range 0 to 1,925 ng/ml), NGAL measurements by enzyme-linked immunosorbent assay and by Triage® NGAL Device (Biosite Inc., San Diego, CA, USA) were highly correlated (r = 0.94). Second, in a subsequent prospective uncontrolled cohort study, 120 children undergoing CPB were enrolled. Plasma was collected at baseline and at frequent intervals for 24 hours after CPB, and analyzed for NGAL using the Triage® NGAL device. The primary outcome was AKI, which was defined as a 50% or greater increase in serum creatinine. Results AKI developed in 45 patients (37%), but the diagnosis using serum creatinine was delayed by 2 to 3 days after CPB. In contrast, mean plasma NGAL levels increased threefold within 2 hours of CPB and remained significantly elevated for the duration of the study. By multivariate analysis, plasma NGAL at 2 hours after CPB was the most powerful independent predictor of AKI (β = 0.004, P < 0.0001). For the 2-hour plasma NGAL measurement, the area under the curve was 0.96, sensitivity was 0.84, and specificity was 0.94 for prediction of AKI using a cut-off value of 150 ng/ml. The 2 hour postoperative plasma NGAL levels strongly correlated with change in creatinine (r = 0.46, P < 0.001), duration of AKI (r = 0.57, P < 0.001), and length of hospital stay (r = 0.44, P < 0.001). The 12-hour plasma NGAL strongly correlated with mortality (r = 0.48, P = 0.004) and all measures of morbidity mentioned above. Conclusion Accurate measurements of plasma NGAL are obtained using the point-of-care Triage® NGAL device. Plasma NGAL is an early predictive biomarker of AKI, morbidity, and mortality after pediatric CPB.
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Affiliation(s)
- Catherine L Dent
- Department of Cardiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, 3333 Burnet Ave, Cincinnati, Ohio 45229, USA
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690
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Devarajan P. Emerging urinary biomarkers in the diagnosis of acute kidney injury. ACTA ACUST UNITED AC 2008; 2:387-398. [PMID: 19079800 DOI: 10.1517/17530059.2.4.387] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND: Acute kidney injury (AKI) represents a common and devastating problem in clinical medicine. The lack of early biomarkers for AKI has led to a delay in initiating potentially effective therapies. OBJECTIVE: Identification of novel urinary biomarkers for AKI that have progressed to the clinical phase of the biomarker discovery process. METHODS: A literature review (PubMed, MedLine) from 2000 to the present. RESULTS/CONCLUSIONS;: The most promising AKI biomarkers include neutrophil gelatinase-associated lipocalin, IL-18, kidney injury molecule-1 and liver-type fatty acid binding protein. Studies to validate the sensitivity and specificity of these biomarkers in clinical samples from large cohorts and from multiple clinical situations are in progress, facilitated by the development of commercial tools for their measurement.
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Affiliation(s)
- Prasad Devarajan
- University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Nephrology and Hypertension, MLC 7022, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
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691
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Bennett M, Dent CL, Ma Q, Dastrala S, Grenier F, Workman R, Syed H, Ali S, Barasch J, Devarajan P. Urine NGAL predicts severity of acute kidney injury after cardiac surgery: a prospective study. Clin J Am Soc Nephrol 2008; 3:665-73. [PMID: 18337554 DOI: 10.2215/cjn.04010907] [Citation(s) in RCA: 514] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND OBJECTIVES The authors have previously shown that urine neutrophil gelatinase-associated lipocalin (NGAL), measured by a research ELISA, is an early predictive biomarker of acute kidney injury (AKI) after cardiopulmonary bypass (CPB). In this study, whether an NGAL immunoassay developed for a standardized clinical platform (ARCHITECT analyzer, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL) can predict AKI after CPB was tested. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In a pilot study with 136 urine samples (NGAL range, 0.3 to 815 ng/ml) and 6 calibration standards (NGAL range, 0 to 1000 ng/ml), NGAL measurements by research ELISA and by the ARCHITECT assay were highly correlated (r = 0.99). In a subsequent study, 196 children undergoing CPB were prospectively enrolled and serial urine NGAL measurements obtained by ARCHITECT assay. The primary outcome was AKI, defined as a > or = 50% increase in serum creatinine. RESULTS AKI developed in 99 patients (51%), but the diagnosis using serum creatinine was delayed by 2 to 3 d after CPB. In contrast, mean urine NGAL levels increased 15-fold within 2 h and by 25-fold at 4 and 6 h after CPB. For the 2-h urine NGAL measurement, the area under the curve was 0.95, sensitivity was 0.82, and the specificity was 0.90 for prediction of AKI using a cutoff value of 100 ng/ml. The 2-h urine NGAL levels correlated with severity and duration of AKI, length of stay, dialysis requirement, and death. CONCLUSIONS Accurate measurements of urine NGAL are obtained using the ARCHITECT platform. Urine NGAL is an early predictive biomarker of AKI severity after CPB.
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Affiliation(s)
- Michael Bennett
- Nephrology & Hypertension, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, OH 45229-3039, USA
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692
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Wei Q, Dong Z. Regulation and pathological role of bid in ischemic acute kidney injury. Ren Fail 2008; 29:935-40. [PMID: 18067037 DOI: 10.1080/08860220701641165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Bid, a BH3-only member of the Bcl-2 family proteins, is most abundantly expressed in the kidneys. Recent research has shown Bid activation in renal tubular cells in vitro following ATP-depletion and hypoxic injury, and also in vivo during renal ischemia-reperfusion in rats and mice. Importantly, Bid-deficient mice are resistant to ischemic kidney injury. Targeting Bid may therefore offer a new strategy for the treatment of acute renal failure associated with ischemia-reperfusion.
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Affiliation(s)
- Qingqing Wei
- Department of Cellular Biology and Anatomy, Medical College of Georgia and Veterans Affairs Medical Center, Augusta, Georgia 30912, USA
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693
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Marumo T, Hishikawa K, Yoshikawa M, Fujita T. Epigenetic regulation of BMP7 in the regenerative response to ischemia. J Am Soc Nephrol 2008; 19:1311-20. [PMID: 18322163 DOI: 10.1681/asn.2007091040] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Kidneys damaged by ischemia have the potential to regenerate through a mechanism involving intrarenal induction of protective factors, including bone morphogenetic protein-7 (BMP7). Epigenetic changes, such as alterations in histone modifications, have also been shown to play a role in various pathologic conditions, but their involvement in ischemic injury and regeneration remains unknown. This study investigated whether changes in histone acetylation, regulated by histone acetyltransferase and histone deacetylase (HDAC), are induced by renal ischemia and involved in the regenerative response. Ischemia/reperfusion of the mouse kidney induced a transient decrease in histone acetylation in proximal tubular cells, likely as a result of a decrease in histone acetyltransferase activity as suggested by experiments with energy-depleted renal epithelial cells in culture. During recovery after transient energy depletion in epithelial cells, the HDAC isozyme HDAC5 was selectively downregulated in parallel with the return of acetylated histone. Knockdown of HDAC5 by RNAi significantly increased histone acetylation and BMP7 expression. BMP7 induction and HDAC5 downregulation in the recovery phase were also observed in proximal tubular cells in vivo after transient ischemia. These data indicate that ischemia induces dynamic epigenetic changes involving HDAC5 downregulation, which contributes to histone re-acetylation and BMP7 induction in the recovery phase. This highlights HDAC5 as a modulator of the regenerative response after ischemia and suggests HDAC5 inhibition may be a therapeutic strategy to enhance BMP7 expression.
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Affiliation(s)
- Takeshi Marumo
- Department of Clinical Renal Regeneration and Division of Nephrology and Endocrinology, Department of Internal Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-8655 Tokyo, Japan.
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694
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Sphingosine-1-phosphate receptors: biology and therapeutic potential in kidney disease. Kidney Int 2008; 73:1220-30. [PMID: 18322542 DOI: 10.1038/ki.2008.34] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The major sphingolipid metabolite, sphingosine-1-phosphate (S1P), has important biological functions. S1P is the ligand for a family of five G-protein-coupled receptors with distinct signaling pathways that regulate angiogenesis, vascular maturation, immunity, chemotaxis, and other important biological pathways. Recently, clinical trials have targeted S1P receptors (S1PRs) for autoimmune diseases and transplantation and have generated considerable interest in developing additional, more selective compounds. This review summarizes current knowledge on the biology of S1P and S1PRs that forms the basis for future drug development and the treatment of kidney disease.
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695
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Maeshima A, Miya M, Mishima K, Yamashita S, Kojima I, Nojima Y. Activin A: autocrine regulator of kidney development and repair. Endocr J 2008; 55:1-9. [PMID: 17827789 DOI: 10.1507/endocrj.kr-113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The research described in this review suggests a novel and important role for activin A in the developmental and repair processes of the kidney (Table 1). The results obtained in these studies indicate that activin A is a negative regulator of kidney development and plays an essential part in kidney diseases, such as acute renal failure or renal fibrosis. It is also possible that activin A is a key player in the pathophysiological processes of other kidney diseases, such as congenital urogenital abnormalities, renal cystic disease and renal cell carcinoma. Activin A is thus a potential target for therapeutic interventions in kidney diseases. To address this issue, more detailed analysis on the regulation of activin production, modulation of activin activity and activin target genes is required.
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Affiliation(s)
- Akito Maeshima
- Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Japan
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696
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Abstract
The process of normal aging affects organ homeostasis as well as responses to acute and chronic injury. In view of the rapid growth in the elderly population, it is increasingly important for us to develop a mechanistic understanding of how these age-dependent changes can impact the susceptibility and response of the kidney to injurious stimuli. In this overview, we focus on the current understanding of those mechanisms by reviewing how cellular changes in the aging kidney might lead to a diminished proliferative reserve, an increased tendency for apoptosis, alterations in growth factor profiles, and changes in potential progenitor and immune cell functions. A better understanding of these processes may help us to define new targets for studying kidney repair and could ultimately lead to new therapeutic strategies that are specifically tailored for treatment of the elderly population.
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Affiliation(s)
- Roland Schmitt
- Department of Nephrology, Hannover Medical School, Hannover, Germany
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697
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Abstract
Acute kidney injury (AKI), previously referred to as acute renal failure, represents a common and devastating problem in clinical medicine. Despite significant improvements in therapeutics, the mortality and morbidity associated with AKI remain high. A major reason for this is the lack of early markers for AKI, and hence an unacceptable delay in initiating therapy. Fortunately, the application of innovative technologies such as functional genomics and proteomics to human and animal models of AKI has uncovered several novel biomarkers and therapeutic targets. The most promising of these are chronicled in this review. These include the identification of biomarker panels in plasma (neutrophil gelatinase-associated lipocalin and cystatin C) and urine (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18, cystatin C, alpha1-microglobulin, Fetuin-A, Gro-alpha, and meprin). It is likely that the AKI panels will be useful for timing the initial insult, and assessing the duration and severity of AKI. It is also probable that the AKI panels will distinguish between the various etiologies of AKI and predict clinical outcomes. It will be important in future studies to validate the sensitivity and specificity of these biomarker panels in clinical samples from large cohorts and from multiple clinical situations. Such studies will be facilitated markedly by the development of commercial tools for the reproducible measurement of biomarkers across different laboratories.
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Affiliation(s)
- Prasad Devarajan
- Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, USA.
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698
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Pabla N, Dong Z. Cisplatin nephrotoxicity: mechanisms and renoprotective strategies. Kidney Int 2008; 73:994-1007. [PMID: 18272962 DOI: 10.1038/sj.ki.5002786] [Citation(s) in RCA: 1300] [Impact Index Per Article: 81.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cisplatin is one of the most widely used and most potent chemotherapy drugs. However, side effects in normal tissues and organs, notably nephrotoxicity in the kidneys, limit the use of cisplatin and related platinum-based therapeutics. Recent research has shed significant new lights on the mechanism of cisplatin nephrotoxicity, especially on the signaling pathways leading to tubular cell death and inflammation. Renoprotective approaches are being discovered, but the protective effects are mostly partial, suggesting the need for combinatorial strategies. Importantly, it is unclear whether these approaches would limit the anticancer effects of cisplatin in tumors. Examination of tumor-bearing animals and identification of novel renoprotective strategies that do not diminish the anticancer efficacy of cisplatin are essential to the development of clinically applicable interventions.
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Affiliation(s)
- N Pabla
- Department of Cellular Biology and Anatomy, Medical College of Georgia and Charlie Norwood VA Medical Center, Augusta, Georgia 30912, USA
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699
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Wu D, Chen X, Ding R, Qiao X, Shi S, Xie Y, Hong Q, Feng Z. Ischemia/reperfusion induce renal tubule apoptosis by inositol 1,4,5-trisphosphate receptor and L-type Ca2+ channel opening. Am J Nephrol 2008; 28:487-99. [PMID: 18185015 DOI: 10.1159/000113107] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 11/12/2007] [Indexed: 01/01/2023]
Abstract
Recent studies suggest that besides the L-type calcium channel, two calcium channels on the endoplasmic reticulum (ER), the inositol 1,4,5-trisphosphate receptor (InsP3R) and ryanodine receptor (RyR), may play a role in the apoptotic process of renal tubular cells induced by ischemia/reperfusion (I/R) injury. We used antimycin A to induce cell I/R injury in vitro and found an elevation of the cytosolic calcium concentration and consequently apoptosis. Blocking either the L-type calcium channel with nicardipine or the InsP3R with TMB-8 can inhibit cytochrome c release, activate caspase 3 and decrease the apoptotic cell number. However, blocking the RyR with dantrolene had no effect. We further found that Ca(2+) influx through the L-type channel is needed for the opening of the InsP3R which activates a cascade of Ca(2+) release from the ER store. To test these blockers in vivo, in a rat renal I/R model, pretreatment with nicardipine and TMB-8, but not dantrolene, can protect renal function. Taken together, our results suggest that after I/R injury, Ca(2+) influx through the L-type calcium channel triggers the Ca(2+) release from the InsP3R and finally induces apoptosis. The InsP3R could be a new target for the treatment of renal I/R injury.
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MESH Headings
- Animals
- Antimycin A
- Apoptosis/drug effects
- Blood Pressure/drug effects
- Calcium/metabolism
- Calcium Channel Blockers
- Calcium Channels, L-Type/metabolism
- Cells, Cultured
- Cytochromes c/metabolism
- DNA Fragmentation/drug effects
- Dantrolene
- Endoplasmic Reticulum/metabolism
- Epithelial Cells/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/antagonists & inhibitors
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Kidney Tubules, Proximal/metabolism
- Kidney Tubules, Proximal/pathology
- Male
- Malondialdehyde/metabolism
- Muscle Relaxants, Central
- Rats
- Rats, Wistar
- Reperfusion Injury/enzymology
- Reperfusion Injury/metabolism
- Reperfusion Injury/pathology
- Ryanodine Receptor Calcium Release Channel/metabolism
- Superoxide Dismutase/metabolism
- Urothelium/metabolism
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Affiliation(s)
- Di Wu
- Department of Nephrology, Kidney Center and Key Laboratory of PLA, General Hospital of PLA, Beijing, PR China
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700
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Abstract
The incidence of both acute kidney injury (AKI, previously referred to as acute renal failure) and chronic kidney disease (CKD) is reaching epidemic proportions. In both situations, early intervention can significantly improve the prognosis. However, the paucity of early, predictive, non-invasive biomarkers has impaired our ability to institute potentially effective therapies for these common clinical conditions in a timely manner. The current status of one of the most promising novel biomarkers, namely neutrophil gelatinase-associated lipocalin (NGAL), is presented in this review. The evidence for the role of NGAL measurements in a variety of clinical situations leading to AKI (cardiac surgery, kidney transplantation, contrast nephropathy, haemolytic uraemic syndrome and in the intensive care setting) or to CKD (lupus nephritis, glomerulonephritides, obstruction, dysplasia, polycystic kidney disease, IgA nephropathy) is explored. The emerging utility of standardized clinical platforms for reliable measurement of NGAL in plasma (Triage NGAL Device; Biosite Incorporated) and urine (ARCHITECT analyzer; Abbott Diagnostics) is also discussed. It will be important in future studies to validate the sensitivity and specificity of NGAL concentration measurements in clinical samples from large cohorts and from multiple clinical situations. Such studies will be facilitated by the anticipated widespread availability of standardized commercial tools in the near future.
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Affiliation(s)
- Prasad Devarajan
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229-2029, USA.
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