renal-ischaemia-reperfusion-injury-mouse-model-injury

Renal Ischaemia Reperfusion Injury: A Mouse Model of Injury and Regeneration

Renal ischaemia reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) in patients and occlusion of renal blood flow is unavoidable ...

University of Edinburgh

Macrophages play a pivotal role in tissue injury and fibrosis during renal inflammation. Although macrophages may induce apoptosis of renal tubular epithelial cells, the mechanisms involved are unclear. We used a microscopically quantifiable co-culture assay to dissect the cytotoxic interaction between murine bone marrow-derived macrophages and Madin-Darby canine kidney cells and primary murine renal tubular epithelial cells. The induction of tubular cell apoptosis by cytokine-activated macrophages was reduced by inhibitors of nitric oxide synthase whereas tubular cell proliferation was unaffected. Furthermore, cytokine-activated macrophages derived from mice targeted for the deletion of inducible nitric oxide synthase were noncytotoxic. We then examined the role of nitric oxide in vivo by inhibiting inducible nitric oxide synthase in the model of murine experimental hydronephrosis. l-N(6)-(1-iminoethyl)-lysine was administered in the drinking water between days 5 and 7 after ureteric obstruction. Macrophage infiltration was comparable between groups, but treatment significantly inhibited tubular cell apoptosis at day 7. Tubular cell proliferation was unaffected. Inducible nitric oxide synthase blockade also reduced interstitial cell apoptosis and increased collagen III deposition. These data indicate that nitric oxide is a key mediator of macrophage-directed tubular cell apoptosis in vitro and in vivo and also modulates tubulointerstitial fibrosis.

Nitric oxide is an important mediator of renal tubular epithelial cell death in vitro and in murine experimental hydronephrosis.

Infiammazione renale possa derivare da una miriade di insulti e spesso &egrave; caratterizzata dalla presenza di infiltrazione infiammatori dei leucociti all&#39;interno del glomerulo o tubulointerstitium. Accumulando prove indica che i leucociti infiltranti sono giocatori chiave nell&#39;induzione del danno renale. Sebbene l&#39;infiammazione renale &egrave; spesso seguita dallo sviluppo di fibrosi, con perdita di funzione renale, pu&ograve; risolvere. Risoluzione pu&ograve; essere spontanea come glomerulonefrite poststreptococcal o dopo la somministrazione di un trattamento efficace come agenti immunosoppressivi. I meccanismi e le cellule sottostanti il processo di risoluzione e l&#39;esatta sequenza temporale rimane incerti al presente ma probabilmente comporta la rimozione dei leucociti pregiudizievoli, la down-regulation della risposta immunitaria e l&#39;alterazione del fenotipo di infiltrazione macrofagi di proinflammatory di prorepair. Questa revisione esamina il ruolo dei leucociti nell&#39;infiammazione renale e la riparazione.

Cellule infiammatorie in riparazione e danno renale.

Renal inflammation may result from a myriad of insults and often is characterized by the presence of infiltrating inflammatory leukocytes within the glomerulus or tubulointerstitium. Accumulating evidence indicates that infiltrating leukocytes are key players in the induction of renal injury. Although renal inflammation often is followed by the development of fibrosis with loss of renal function, it can resolve. Resolution may be spontaneous as in poststreptococcal glomerulonephritis or after the administration of effective treatment such as immunosuppressive agents. The mechanisms and cells underlying the resolution process and the exact temporal sequence remains uncertain at present but likely involves the removal of injurious leukocytes, the down-regulation of immune responses, and the alteration of the phenotype of infiltrating macrophages from proinflammatory to prorepair. In this review we examine the role of leukocytes in both renal inflammation and repair.

Inflammatory cells in renal injury and repair.

Inflammation r&eacute;nale peut entra&icirc;ner une myriade d&#39;insultes et souvent se caract&eacute;rise par la pr&eacute;sence d&#39;infiltration de leucocytes inflammatoires au sein du glom&eacute;rule ou tubulointerstitium. Accumulation de preuves indique que les leucocytes infiltrantes sont des acteurs cl&eacute;s dans l&#39;induction de l&eacute;sion r&eacute;nale. Bien que l&#39;inflammation r&eacute;nale est souvent suivie par le d&eacute;veloppement de la fibrose avec perte de la fonction r&eacute;nale, il peut r&eacute;soudre. R&eacute;solution peut &ecirc;tre spontan&eacute;e comme dans la glom&eacute;rulon&eacute;phrite poststreptococcique ou apr&egrave;s l&#39;administration d&#39;un traitement efficace comme agents immunosuppresseurs. Les m&eacute;canismes et les cellules qui sous-tend le processus de r&eacute;solution et les restes de la s&eacute;quence temporelle exacte incertaines &agrave; pr&eacute;sent mais probablement implique la suppression de leucocytes pr&eacute;judiciables, la r&eacute;gulation des r&eacute;ponses immunitaires et la modification du ph&eacute;notype d&#39;infiltration de macrophages de pro-inflammatoires &agrave; prorepair. Dans cette revue, nous examinons le r&ocirc;le des leucocytes dans l&#39;inflammation r&eacute;nale et de r&eacute;paration.

Cellules inflammatoires dans les l&eacute;sions r&eacute;nales et de la r&eacute;paration.

Kupffer cells are the resident macrophage population of the liver and have previously been implicated in the pathogenesis of hepatic ischemia-reperfusion injury (IRI). Kupffer cells are the major site of expression of hepatic heme oxygenase-1 (HO-1), which has been shown to have anti-inflammatory actions and to protect animals and cells from oxidative injury. Kupffer cells and circulating monocytes were selectively ablated using liposomal clodronate (LC) in the CD11b DTR mouse before induction of hepatic ischemia. Kupffer cell depletion resulted in loss of HO-1 expression and increased susceptibility to hepatic IRI, whereas ablation of circulating monocytes did not affect IRI phenotype. Targeted deletion of HO-1 rendered mice highly susceptible to hepatic IRI. In vivo, HO-1 deletion resulted in pro-inflammatory Kupffer cell differentiation characterized by enhanced Ly6c and MARCO (macrophage receptor with collagenous structure) expression as well as decreased F4/80 expression, mirrored by an expansion in immature circulating monocytes. In vitro, HO-1 inhibition throughout macrophage differentiation led to increased cell numbers, and pro-inflammatory Ly6c+ CD11c- F4/80- phenotype. These data support a critical role for tissue-resident macrophages in homeostasis following ischemic injury, and a co-dependence of HO-1 expression and tissue-resident macrophage differentiation.

Tissue-resident macrophages protect the liver from ischemia reperfusion injury via a heme oxygenase-1-dependent mechanism.

Les cellules de Kupffer sont la population r&eacute;sident macrophages du foie et ont d&eacute;j&agrave; &eacute;t&eacute; impliqu&eacute;s dans la pathogen&egrave;se des l&eacute;sions h&eacute;patiques isch&eacute;mie-reperfusion (IRI). Les cellules de Kupffer sont le principal lieu d&#39;expression de l&#39;h&eacute;patique h&egrave;me oxyg&eacute;nase-1 (HO-1), qui a &eacute;t&eacute; montr&eacute; pour avoir des effets anti-inflammatoires et &agrave; prot&eacute;ger les animaux et les cellules du dommage oxydatif. Les cellules de Kupffer et monocytes circulants ont &eacute;t&eacute; s&eacute;lectivement ablation &agrave; l&#39;aide de liposomes clodronate (LC) chez la souris CD11b DTR avant l&#39;induction d&#39;une isch&eacute;mie h&eacute;patique. &Eacute;puisement de cellules de Kupffer a r&eacute;sult&eacute; en une perte d&#39;expression de l&#39;HO-1 et une susceptibilit&eacute; accrue &agrave; l&#39;IRI h&eacute;patique, tandis que l&#39;ablation des monocytes circulants n&#39;affectait pas le ph&eacute;notype de l&#39;IRI. Suppression cibl&eacute;e de HO-1 rendue souris tr&egrave;s sensibles &agrave; l&#39;IRI h&eacute;patique. In vivo, HO-1 suppression entra&icirc;n&eacute; pro-inflammatoires Kupffer diff&eacute;renciation cellulaire caract&eacute;ris&eacute;e par des expression accrue de Ly6c et MARCO (receveur de macrophages avec structure collag&eacute;nique) ainsi qu&#39;a diminu&eacute; l&#39;expression F4/80, refl&eacute;t&eacute;e par une augmentation des monocytes circulants immatures. Inhibition in vitro, HO-1 dans toute diff&eacute;renciation de macrophages conduit &agrave; des num&eacute;ros de cellulaire accrue et pro-inflammatoires Ly6c + CD11c-F4/80-ph&eacute;notype. Ces donn&eacute;es confirment un r&ocirc;le critique pour les macrophages de tissu-r&eacute;sident dans l&#39;hom&eacute;ostasie suite &agrave; une l&eacute;sion isch&eacute;mique et une interd&eacute;pendance de HO-1 expression et diff&eacute;renciation des macrophages de tissu-r&eacute;sident.

Macrophages r&eacute;sidents tissus prot&egrave;gent le foie d&#39;isch&eacute;mie reperfusion injury via un m&eacute;canisme de h&egrave;me oxyg&eacute;nase-1-d&eacute;pendante.

Cellule di Kupffer sono la popolazione residente dei macrofagi del fegato e precedentemente sono state implicate nella patogenesi del danno epatico da ischemia-riperfusione (IRI). Cellule di Kupffer sono il sito principale di espressione di epatica eme ossigenasi-1 (HO-1), che ha dimostrato di avere le azioni anti-infiammatorie e di proteggere gli animali e le cellule dal danno ossidativo. Cellule di Kupffer e monociti circolanti sono stati selettivamente ablazione utilizzando liposomiale clodronate (LC) nel topo CD11b DTR prima dell&#39;induzione di ischemia epatica. Deplezione delle cellule di Kupffer ha provocato perdita di espressione di HO-1 e aumento della suscettibilit&agrave; all&#39;IRI epatica, considerando che l&#39;ablazione di monociti circolanti non influisce sulla fenotipo IRI. Eliminazione mirata di HO-1 reso topi altamente suscettibili all&#39;IRI epatica. Eliminazione in vivo, HO-1 ha provocato pro-infiammatorie Kupffer differenziamento cellulare caratterizzato da una maggiore Ly6c e MARCO (macrofago con struttura collagenosica) espressione dei recettori come pure diminuita espressione F4/80, specchiato di un&#39;espansione in immaturi monociti circolanti. Inibizione in vitro, HO-1 durante la differenziazione dei macrofagi ha portato a numeri di cellulare aumentato e pro-infiammatoria Ly6c + CD11c-F4/80-fenotipo. Questi dati supportano un ruolo critico per tessuto residenti macrofagi nell&#39;omeostasi dopo lesione ischemica e una co-dipendenza di espressione di HO-1 e la differenziazione dei macrofagi dei tessuti-residente.

Macrofagi residenti in tessuto proteggono il fegato da danno da riperfusione ischemia attraverso un meccanismo di eme ossigenasi-1-dipendente.

Gandolfo et al. report the key role played by regulatory T cells in modulating recovery from ischemic renal injury. The role of regulatory T cells in modulating ischemia-reperfusion injury in the kidney and other organs is discussed in this commentary.

Regulatory T cells: a brake on ischemic injury or an active promoter of tissue healing?

Gandolfo et coll. rapportent le r&ocirc;le cl&eacute; jou&eacute; par les lymphocytes T r&eacute;gulateurs dans r&eacute;cup&eacute;ration modulante de l&eacute;sion r&eacute;nale isch&eacute;mique. Le r&ocirc;le des lymphocytes T r&eacute;gulateurs de l&#39;isch&eacute;mie-reperfusion dans les reins et autres organes de modulation est discut&eacute; dans ce commentaire.

Les lymphocytes T r&eacute;gulateurs : un frein sur une l&eacute;sion isch&eacute;mique ou un promoteur actif de la gu&eacute;rison des tissus ?

Gandolfo et al riportano il ruolo chiave svolto da cellule T regolatorie nel recupero modulante da lesione ischemica renale. Il ruolo delle cellule T regolatorie nel modulare la lesione ischemia-reperfusion nel rene e di altri organi &egrave; discusso in questo commento.

Cellule T regolatorie: un freno sulla lesione ischemica o un promotore attivo di guarigione dei tessuti?

Degradation by the inducible enzyme hemeoxygenase-1 (HO-1) is the principal route of mammalian heme metabolism. The resultant generation of free iron, carbon monoxide and biliverdin results in myriad actions including promoting cell survival, circulatory integrity and immunomodulation. This review examines the evidence from both human studies and work performed in experimental models implicating the intrinsic heme-HO-1 pathway as important in determining both the susceptibility and severity of acute kidney injury. Additional work using chemical inducers of HO-1 has demonstrated the efficacy of strategies to upregulate enzyme activity in ameliorating the severity of experimental ischaemia-reperfusion injury whilst genetic ablation of HO-1 or pharmacological inhibition of HO-1 activity results in an augmented injury phenotype. There remain a multitude of candidate pathways to account for the therapeutic efficacy of HO-1 induction. Although this may reflect a truly multifactorial mechanism of action, the identification of the relative contribution of key components such as carbon monoxide generation remains critical to allow the rational design of agents for translational application in human disease.

Hemeoxygenase-1 and renal ischaemia-reperfusion injury.

D&eacute;gradation par l&#39;enzyme inductible hemeoxygenase-1 (HO-1) est la principale voie du m&eacute;tabolisme de l&#39;h&egrave;me chez les mammif&egrave;res. La g&eacute;n&eacute;ration qui en r&eacute;sultent de fer libre, de monoxyde de carbone et de r&eacute;sultats de biliverdine dans des actions multiples incluant la promotion de la survie cellulaire, int&eacute;grit&eacute; circulatoire et l&#39;immunomodulation. La pr&eacute;sente analyse examine les &eacute;l&eacute;ments de preuve &agrave; la fois des &eacute;tudes et travaux ex&eacute;cut&eacute;s sur des mod&egrave;les exp&eacute;rimentaux, impliquant la voie intrins&egrave;que d&#39;h&egrave;me-HO-1 aussi important dans la d&eacute;termination de la susceptibilit&eacute; et la s&eacute;v&eacute;rit&eacute; de l&#39;insuffisance r&eacute;nale aigu&euml;. Des travaux suppl&eacute;mentaires &agrave; l&#39;aide d&#39;inducteurs chimiques de HO-1 a d&eacute;montr&eacute; l&#39;efficacit&eacute; des strat&eacute;gies visant &agrave; augmenter l&#39;activit&eacute; enzymatique en att&eacute;nuer la gravit&eacute; des blessures de l&#39;isch&eacute;mie-reperfusion exp&eacute;rimentale tandis qu&#39;ablation g&eacute;n&eacute;tique de HO-1 ou l&#39;inhibition pharmacologique de HO-1 entra&icirc;ne un ph&eacute;notype de blessure augment&eacute;e. Il reste une multitude de sentiers de candidat pour tenir compte de l&#39;efficacit&eacute; th&eacute;rapeutique d&#39;induction de HO-1. Bien que cela peut refl&eacute;ter un v&eacute;ritable multifactoriel m&eacute;canisme d&#39;action, l&#39;identification de la contribution relative des composantes cl&eacute;s comme la production de monoxyde de carbone demeure critique pour permettre la conception rationnelle des agents pour l&#39;application translationnelle dans la maladie humaine.

L&eacute;sion d&#39;isch&eacute;mie-reperfusion r&eacute;nale et Hemeoxygenase-1.

Degradazione dell&#39;enzima inducibile hemeoxygenase-1 (HO-1) &egrave; l&#39;itinerario principale del metabolismo dell&#39;eme dei mammiferi. La conseguente generazione di ferro libero, monossido di carbonio e Biliverdina risultati in innumerevoli azioni tra cui promuovere la sopravvivenza delle cellule, l&#39;integrit&agrave; circolatorio e immunomodulazione. Questa revisione esamina le prove da studi umani e lavoro eseguito in modelli sperimentali, implicando il pathway intrinseco eme-HO-1 come importante nel determinare la suscettibilit&agrave; e la gravit&agrave; delle lesioni renali acute. Lavoro supplementare utilizzando induttori chimici di HO-1 ha dimostrato l&#39;efficacia delle strategie di potenziamento attivit&agrave; enzimatica nel miglioramento della gravit&agrave; della lesione sperimentale ischemia-reperfusion mentre l&#39;ablazione genetica di HO-1 o inibizione farmacologica di HO-1 attivit&agrave; si traduce in un fenotipo lesioni aumentata. Ci rimangono una moltitudine di percorsi candidato per tenere conto dell&#39;effetto terapeutico di induzione di HO-1. Anche se questo pu&ograve; riflettere un veramente multifattoriale meccanismo d&#39;azione, l&#39;identificazione del relativo contributo di componenti chiave come il monossido di carbonio generazione rimane critica per consentire la razionale progettazione degli agenti per applicazione traslazionale in malattie umane.

Lesione renale e Hemeoxygenase-1 ischemia-reperfusion.

Acute kidney injury has a high mortality and lacks specific therapies, with ischemia/reperfusion injury (IRI) being the predominant cause. Macrophages (M phi) have been used successfully in cell therapy to deliver targeted therapeutic genes in models of inflammatory kidney disease. Heme oxygenase-1 (HO-1) catalyzes heme breakdown and has important cytoprotective functions. We hypothesized that administration of M phi modified to overexpress HO-1 would protect from renal IRI. Using an adenoviral construct (Ad-HO-1), HO-1 was overexpressed in primary bone marrow-derived M phi (BMDM). In vitro Ad-HO-1 M phi showed an anti-inflammatory phenotype with increased phagocytosis of apoptotic cells (ACs) and increased interleukin (IL)-10 but reduced TNF-alpha and nitric oxide (NO) following lipopolysaccharide/interferon-gamma (IFN gamma) stimulation compared to control transduced or unmodified M phi. In vivo, intravenously (IV) injected M phi homed preferentially to the post-IRI kidney compared to uninjured control following experimental IRI. At 24 hours postinjury, despite equivalent levels of tubular necrosis, apoptosis, and capillary density between groups, the injection of Ad-HO-1 M phi resulted in preserved renal function (serum creatinine reduced by 46%), and reduced microvascular platelet deposition. These data demonstrate that genetically modified M phi improve the outcomes in IRI when administered after the establishment of structural injury, raising the prospect of targeted cell therapy to support the function of the acutely injured kidney.

Macrophages expressing heme oxygenase-1 improve renal function in ischemia/reperfusion injury.

Insuffisance r&eacute;nale aigu&euml; a une mortalit&eacute; &eacute;lev&eacute;e et manque de th&eacute;rapies sp&eacute;cifiques, avec isch&eacute;mie/reperfusion (IRI) &eacute;tant la principale cause. Macrophages (phi M) ont &eacute;t&eacute; utilis&eacute;s avec succ&egrave;s dans la th&eacute;rapie cellulaire pour livrer des g&egrave;nes th&eacute;rapeutiques cibl&eacute;s dans les mod&egrave;les de la maladie de rein inflammatoires. H&egrave;me oxyg&eacute;nase-1 (HO-1) catalyse la d&eacute;gradation de l&#39;h&egrave;me et a des fonctions importantes cytoprotecteurs. Nous avons &eacute;mis l&#39;hypoth&egrave;se que l&#39;administration de M phi modifi&eacute;e d&#39;overexpress HO-1 prot&eacute;gerait contre IRI r&eacute;nale. &Agrave; l&#39;aide d&#39;une construction ad&eacute;novirale (Ad-HO-1), HO-1 &eacute;tait surexprim&eacute; dans primaire moelle osseuse M phi (BMDM). In vitro Ad-HO-1 M phi a montr&eacute; un ph&eacute;notype anti-inflammatoires avec augmentation phagocytose des cellules apoptotiques (ACs) et accrue interleukine (IL) -10 mais r&eacute;duite de TNF-alpha et de l&#39;oxyde nitrique (aucun) apr&egrave;s la stimulation lipopolysaccharide/interf&eacute;ron-gamma (IFN-gamma) compar&eacute;e pour contr&ocirc;ler transduite ou non modifi&eacute;e M phi. In vivo, par voie intraveineuse (IV) inject&eacute; M phi h&eacute;berg&eacute;s pr&eacute;f&eacute;rentiellement pour le rein post-IRI par rapport au t&eacute;moin indemne suite IRI exp&eacute;rimentale. &Agrave; postinjury 24 heures, malgr&eacute; des niveaux &eacute;quivalents de n&eacute;crose tubulaire, l&#39;apoptose et la densit&eacute; capillaire entre les groupes, l&#39;injection de Ad-HO-1 M phi a donn&eacute; lieu &agrave; une fonction r&eacute;nale pr&eacute;serv&eacute;e (cr&eacute;atinin&eacute;mie r&eacute;duit de 46 %) et r&eacute;duit les d&eacute;p&ocirc;ts de plaquettes microvasculaire. Ces r&eacute;sultats d&eacute;montrent que phi M g&eacute;n&eacute;tiquement modifi&eacute; am&eacute;liorer les r&eacute;sultats en IRI lorsqu&#39;il est administr&eacute; apr&egrave;s la mise en place de dommage structurel, soulevant la perspective de cibl&eacute; la th&eacute;rapie cellulaire pour appuyer la fonction du rein gravement bless&eacute;.

Macrophages exprimant l&#39;h&egrave;me oxyg&eacute;nase-1 am&eacute;liorent la fonction r&eacute;nale dans l&#39;isch&eacute;mie/reperfusion.

Danno renale acuto ha un alto tasso di mortalit&agrave; e manca di terapie specifiche, con lesioni di ischemia/riperfusione (IRI) essendo la causa predominante. Macrofagi (M phi) sono stati utilizzati con successo nella terapia cellulare per trasportare geni terapeutici mirati in modelli di malattie infiammatorie renali. Eme ossigenasi-1 (HO-1) catalizza la seguente ripartizione di heme e ha citoprotettivo importanti funzioni. Abbiamo ipotizzato che la somministrazione di M phi modificato ai overexpress HO-1 proteggerebbe da IRI renale. Utilizzando un costrutto adenovirale (Ad-HO-1), HO-1 era overexpressed in primarie derivate da midollo osseo M phi (BMDM). Phi annuncio-HO-1 M in vitro hanno mostrato un fenotipo anti-infiammatorio con aumentata fagocitosi delle cellule apoptotiche (ACs) e aumentato interleuchina (IL) -10, ma ridotta TNF-alfa e ossido nitrico (NO) seguente stimolazione lipopolisaccaride/interferone-gamma (IFN gamma) rispetto al controllo non modificato o trasdotte M phi. In vivo, per via endovenosa (IV) iniettato M phi homed preferenzialmente al rene post-IRI rispetto al controllo illeso dopo IRI sperimentale. A postinjury di 24 ore, nonostante livelli equivalenti di necrosi tubulare, apoptosi e densit&agrave; capillare tra i gruppi, l&#39;iniezione di annuncio-HO-1 M phi portato a conservata funzione renale (creatinina sierica ridotta del 46%) e ridotta deposizione piastrinica microvascolare. Questi dati dimostrano che geneticamente modificati phi M migliorare i risultati in IRI quando somministrato dopo l&#39;istituzione delle lesioni strutturali, alzando la prospettiva di mirata terapia cellulare per supportare la funzione del rene acutamente ferito.

Macrofagi che esprimono eme ossigenasi-1 migliorano la funzione renale nel danno da ischemia/riperfusione.

Macrophages play an important role in many aspects of tissue injury, inflammation, and repair. Macrophage accumulation is found in most forms of renal disease and depletion studies have shown that they contribute to injury. However, it is also clear that monocytes and macrophages can develop reparative properties that are critical to disease resolution. A number of studies have now shown that macrophages can be transduced or stimulated ex vivo, injected after the initiation of disease, and localize preferentially to the site of renal inflammation. Such macrophage cell therapy can result in reduced inflammation and fibrosis and lead to improved renal function and attenuation of proteinuria. These studies provide a platform for future translational approaches in human renal disease.

Macrophage cell therapy in renal disease.

Les macrophages jouent un r&ocirc;le important dans de nombreux aspects d&#39;une l&eacute;sion tissulaire, l&#39;inflammation et r&eacute;parer. L&#39;accumulation des macrophages se trouve dans la plupart des formes de la maladie r&eacute;nale et appauvrissement ont d&eacute;montr&eacute; qu&#39;ils contribuent &agrave; l&#39;injure. Toutefois, il est &eacute;galement clair que les monocytes et les macrophages peuvent d&eacute;velopper des propri&eacute;t&eacute;s r&eacute;paratrices qui sont essentielles &agrave; la r&eacute;solution de la maladie. Plusieurs &eacute;tudes ont montr&eacute; que les macrophages peuvent &ecirc;tre transduites ou stimul&eacute;e par ex vivo, inject&eacute; apr&egrave;s introduction de la maladie et localiser pr&eacute;f&eacute;rentiellement vers le site de l&#39;inflammation r&eacute;nale. Cette th&eacute;rapie par cellules macrophages peut entra&icirc;ner r&eacute;duite l&#39;inflammation et la fibrose et conduire &agrave; l&#39;am&eacute;lioration de la fonction r&eacute;nale et l&#39;att&eacute;nuation de la prot&eacute;inurie. Ces &eacute;tudes fournissent une plate-forme pour futures approches translationnelles dans les maladies r&eacute;nales humaines.

Th&eacute;rapie cellulaire de macrophages dans l&#39;insuffisance r&eacute;nale.

I macrofagi svolgono un ruolo importante in molti aspetti delle lesioni tessutali, infiammazione e la ripristino. Accumulo di macrofagi &egrave; trovato nella maggior parte delle forme di malattia renale e deplezione studi hanno dimostrato che contribuiscono alla lesione. Tuttavia, &egrave; anche chiaro che monociti e macrofagi possono sviluppare Propriet&agrave; riparative che sono fondamentali per la risoluzione della malattia. Un certo numero di studi hanno ora dimostrato che macrofagi possono essere transduced o stimolati ex vivo, iniettato dopo l&#39;inizio della malattia e si localizza preferenzialmente al sito di infiammazione renale. Tale terapia cellulare dei macrofagi pu&ograve; provocare ridotta infiammazione e fibrosi e portare a miglioramento della funzione renale e l&#39;attenuazione della proteinuria. Questi studi forniscono una piattaforma per futuri approcci traslazionali nella malattia renale umano.

Terapia cellulare dei macrofagi nell&#39;insufficienza renale cronica.

Vieillissement semble &ecirc;tre associ&eacute;e &agrave; une susceptibilit&eacute; accrue aux l&eacute;sions d&#39;isch&eacute;mie-reperfusion r&eacute;nale (IRI). Afin d&#39;&eacute;tudier si l&#39;induction d&eacute;fectueuse de la hemeoxygenase-1 (HO-1, une enzyme protectrice et anti-inflammatoires) pourrait contribuer &agrave; cela, nous avons constat&eacute; que, tandis que 12 mois souris avaient une fonction r&eacute;nale similaire de base et l&#39;expression HO-1, l&#39;induction de HO-1 g&eacute;n&eacute;ralement vu dans l&#39;isch&eacute;mie-reperfusion a &eacute;t&eacute; r&eacute;duite. C&#39;&eacute;tait &eacute;galement associ&eacute;e &agrave; la d&eacute;t&eacute;rioration de la fonction r&eacute;nale et une n&eacute;crose tubulaire aigu&euml; dans les personnes &acirc;g&eacute;es par rapport aux souris jeunes. Chez les souris &acirc;g&eacute;es, h&egrave;me arginate (HA) induit HO-1 dans le cortex et la m&eacute;dulla, l&#39;am&eacute;lioration significative de la fonction r&eacute;nale et r&eacute;duit les l&eacute;sions tissulaires. Cellulaire induction HO-1 dans la m&eacute;dulla en r&eacute;ponse &agrave; des blessures ou HA traitement s&#39;est av&eacute;r&eacute;e interstitielle et non &eacute;pith&eacute;liales, comme en t&eacute;moigne sa co-localisation avec marqueurs de macrophages. In vitro, HA traitement des macrophages primaires a marqu&eacute; HO-1 induction sans alt&eacute;ration des voies d&#39;activation classique. &Eacute;puisement des macrophages, provoqu&eacute;e par le traitement de toxine dipht&eacute;rique d&#39;animaux transg&eacute;niques de 12 mois CD11b-DTR, a entra&icirc;n&eacute; la perte de cellules interstitielles de HO-1 positive et inversion du ph&eacute;notype protecteur du traitement HA. Ainsi, &eacute;chec de l&#39;induction de HO-1 suite IRI r&eacute;nale s&#39;aggrave les l&eacute;sions structurales et fonctionnelles chez les souris &acirc;g&eacute;es et repr&eacute;sente une cible th&eacute;rapeutique chez les personnes &acirc;g&eacute;es. Par cons&eacute;quent, macrophages r&eacute;nales HO-1 positives m&eacute;dient protection induite par HA en IRI.

L&#39;induction de macrophage hemeoxygenase-1 assure une protection au cours de la l&eacute;sion r&eacute;nale aigu&euml; au cours du vieillissement souris.

Aging is thought to be associated with a higher susceptibility to renal ischemia-reperfusion injury (IRI). To study whether defective induction of hemeoxygenase-1 (HO-1, a protective and anti-inflammatory enzyme) might contribute to this, we found that while 12-month-old mice had similar baseline renal function and HO-1 expression, the induction of HO-1 usually seen in ischemia-reperfusion was reduced. This was also associated with worsened renal function and acute tubular necrosis in the aged compared with young mice. In the older mice, heme arginate (HA) induced HO-1 in the cortex and medulla, significantly improved renal function, and reduced tissue injury. Cellular HO-1 induction in the medulla in response to injury or HA treatment was found to be interstitial rather than epithelial, as evidenced by its colocalization with macrophage markers. In vitro, HA treatment of primary macrophages resulted in marked HO-1 induction without impairment of classical activation pathways. Macrophage depletion, caused by diphtheria toxin treatment of 12-month-old CD11b-DTR transgenic animals, resulted in the loss of interstitial HO-1-positive cells and reversal of the protective phenotype of HA treatment. Thus, failure of HO-1 induction following renal IRI worsens structural and functional injury in older mice and represents a therapeutic target in the elderly. Hence, HO-1-positive renal macrophages mediate HA-induced protection in IRI.

The induction of macrophage hemeoxygenase-1 is protective during acute kidney injury in aging mice.

Invecchiamento &egrave; pensato per essere associato con una maggiore suscettibilit&agrave; al danno renale ischemia-riperfusione (IRI). Per studiare se difettoso induzione di hemeoxygenase-1 (HO-1, un enzima protettivo e anti-infiammatorio) potrebbe contribuire a questo, abbiamo trovato che mentre 12-month-old topi avevano simile funzione renale di base e l&#39;espressione di HO-1, l&#39;induzione di HO-1 di solito visto in ischemia-reperfusion &egrave; stato ridotto. Questa &egrave; stata anche associata con peggioramento funzione renale e necrosi tubulare acuta in et&agrave; rispetto ai topi giovani. Nei topi anziani, EME arginato (HA) indotta da HO-1 nella corteccia e midollo, notevolmente migliorata la funzione renale e ridotto lesioni tessutali. Induzione di HO-1 cellulare nel midollo in risposta a lesioni o trattamento HA &egrave; stato trovato essere interstiziale anzich&eacute; epiteliali, come evidenziato dalla sua presenza con marcatori dei macrofagi. In vitro, HA trattamento dei macrofagi primari provocato contrassegnato HO-1 induzione senza compromissione delle vie di attivazione classica. Deplezione dei macrofagi, causata dal trattamento con tossina difterite di animali transgenici CD11b-DTR di 12 mesi, ha provocato la perdita delle cellule interstiziali di HO-1 positivi e inversione del fenotipo HA trattamento protettivo. Cos&igrave;, guasto di HO-1 induzione seguito IRI renale peggiora lesioni strutturali e funzionali nei topi anziani e rappresenta un obiettivo terapeutico nei pazienti anziani. Quindi, macrofagi renali HO-1-positivi mediano protezione HA indotto in IRI.

L&#39;induzione del macrofago hemeoxygenase-1 &egrave; protettivo durante il danno renale acuto in topi di invecchiamento.

The study objective was to determine the key early mechanisms underlying the beneficial redistribution, function, and inflammatory profile of adipose tissue in 11β-hydroxysteroid dehydrogenase type 1 knockout (11β-HSD1(-/-)) mice fed a high-fat (HF) diet.

Novel fat depot-specific mechanisms underlie resistance to visceral obesity and inflammation in 11 β-hydroxysteroid dehydrogenase type 1-deficient mice.

Garcia et al. report the utility of pharmacological activation of the adenosine A(2A) receptor (A(2A)R) in preserving renal function, reversing fibrosis, and reducing macrophage infiltration and inflammatory activation in rat nephrotoxic nephritis. The role of A(2A)R activation in determining outcome in renal inflammation is discussed.

Adenosine A(2A) agonists as therapy for glomerulonephritis.

The role of resident renal mononuclear phagocytes in acute kidney injury is controversial with experimental data suggesting both deleterious and protective functions. To help resolve this, we used mice transgenic for the human diphtheria toxin receptor under the control of the CD11b promoter and treated them with diphtheria toxin, or liposomal clodronate, or both to deplete monocyte/mononuclear phagocytes prior to renal ischemia/reperfusion injury. Although either system effectively depleted circulating monocytes and resident mononuclear phagocytes, depletion was most marked in diphtheria toxin-treated mice. Despite this, diphtheria toxin treatment did not protect from renal ischemia. In contrast, mice treated with clodronate exhibited reduced renal failure and acute tubular necrosis, suggesting key differences between these depletion strategies. Clodronate did not deplete CD206-positive renal macrophages and, unlike diphtheria toxin, left resident CD11c-positive cells unscathed while inducing dramatic apoptosis in hepatic and splenic mononuclear phagocyte populations. Abolition of the protected phenotype by administration of diphtheria toxin to clodronate-treated mice suggested that the protective effect of clodronate resulted from the presence of a cytoprotective intrarenal population of mononuclear phagocytes sensitive to diphtheria toxin-mediated ablation.

Macrophage/monocyte depletion by clodronate, but not diphtheria toxin, improves renal ischemia/reperfusion injury in mice.

Le r&ocirc;le du r&eacute;sidents phagocytes mononucl&eacute;&eacute;es r&eacute;nales dans l&#39;insuffisance r&eacute;nale aigu&euml; est controvers&eacute; avec les donn&eacute;es exp&eacute;rimentales sugg&eacute;rant des fonctions d&eacute;l&eacute;t&egrave;res et de protection. Pour aider &agrave; r&eacute;soudre ce probl&egrave;me, nous avons utilis&eacute; des souris transg&eacute;niques pour le r&eacute;cepteur de la toxine dipht&eacute;rique humaine sous le contr&ocirc;le du promoteur CD11b et trait&eacute;s avec la toxine dipht&eacute;rique, ou clodronate liposomale ou les deux pour &eacute;puiser les monocytes/mononucl&eacute;aires phagocytes avant l&#39;isch&eacute;mie/reperfusion r&eacute;nale. Bien que chaque syst&egrave;me appauvri efficacement circulant de monocytes et de r&eacute;sident mononucl&eacute;aire phagocytes, appauvrissement de la couche a &eacute;t&eacute; plus marqu&eacute;e chez les souris trait&eacute;es &agrave; la toxine dipht&eacute;rique. Malgr&eacute; cela, le traitement de la toxine dipht&eacute;rique ne prot&egrave;ge pas de l&#39;isch&eacute;mie r&eacute;nale. En revanche, les souris trait&eacute;es avec le clodronate expos&eacute;e r&eacute;duit insuffisance r&eacute;nale et une n&eacute;crose tubulaire aigu&euml;, sugg&eacute;rant des principales diff&eacute;rences entre ces strat&eacute;gies d&#39;&eacute;puisement. Clodronate appauvrissent pas macrophages r&eacute;nales CD206 positifs et, contrairement &agrave; la toxine dipht&eacute;rique, rel&egrave;ve des cellules positives &agrave; CD11c r&eacute;sidents indemne tout en induisant l&#39;apoptose dramatique des populations phagocyte mononucl&eacute;aire h&eacute;patiques et spl&eacute;niques. Abolition du ph&eacute;notype prot&eacute;g&eacute;e par l&#39;administration de la toxine dipht&eacute;rique &agrave; souris trait&eacute;es au clodronate a sugg&eacute;r&eacute; que l&#39;effet protecteur du clodronate r&eacute;sulte de la pr&eacute;sence d&#39;une population de cytoprotecteurs intrar&eacute;nale des phagocytes mononucl&eacute;es sensibles &agrave; l&#39;ablation induite par la toxine dipht&eacute;rique.

&Eacute;puisement des macrophages/monocytes par clodronate, mais pas la toxine dipht&eacute;rique, am&eacute;liore r&eacute;nale isch&eacute;mie/reperfusion chez la souris.

Il ruolo del residente fagociti mononucleati renale in lesioni renali acute &egrave; controverso con dati sperimentali suggeriscono funzioni sia deleterie e protettive. Per aiutare a risolvere questo problema, abbiamo utilizzato topi transgenici per il recettore della tossina di difterite umana sotto il controllo del promotore CD11b e li trattavano con tossina difterica, o clodronate liposomiale o entrambi per esaurire i fagociti mononucleati e monociti prima della lesione renale ischemia/reperfusion. Sebbene sia sistema efficacemente impoverito circolanti monociti e residente mononucleari fagociti, deplezione pi&ugrave; fu segnato nei topi trattati con tossina di difterite. Nonostante questo, trattamento con tossina difterite non proteggeva da ischemia renale. Al contrario, topi trattati con clodronate esposto ridotto insufficienza renale e necrosi tubulare acuta, suggerendo differenze principali tra queste strategie di esaurimento. Clodronate non ha fatto esaurire macrofagi renali CD206-positivo e, a differenza di tossina difterica, lasciato residente cellule CD11c-positive illeso mentre indurre apoptosi drammatica nelle popolazioni fagocita mononucleari epatica e splenica. Abolizione del fenotipo protetto mediante somministrazione di tossina difterica per topi trattati clodronate ha suggerito che l&#39;effetto protettivo di clodronate ha provocato dalla presenza di una popolazione intrarenale citoprotettivo dei fagociti mononucleati sensibili per l&#39;ablazione di difterite tossina-mediate.

Deplezione dei macrofagi/monociti da clodronate, ma non la tossina difterica, migliora la lesione renale ischemia/reperfusion nei topi.

Acute lung injury (ALI) is an important cause of morbidity and mortality, with no currently effective pharmacological therapies. Neutrophils have been specifically implicated in the pathogenesis of ALI, and there has been significant research into the mechanisms of early neutrophil recruitment, but those controlling the later phases of neutrophil emigration that characterize disease are poorly understood.

Monocytes control second-phase neutrophil emigration in established lipopolysaccharide-induced murine lung injury.

This case describes the unexpected survival of an adult man who presented to the emergency department with hypovolaemic shock secondary to a splenic haemorrhage. Before surgery he had a pH 6.527, base excess (BE) -34.2 mmol/l and lactate 15.6 mmol/l. He underwent a splenectomy after which his condition stabilised. He was managed in the intensive care unit postoperatively where he required organ support including renal replacement therapy but was subsequently discharged home with no neurological or renal deficit. Although there are case reports of patients surviving such profound metabolic acidosis these have mainly been cases of near drowning or toxic alcohol ingestion. To the best of our knowledge this is the first reported case of survival after a pH of 6.5 secondary to hypovolaemic shock.

David Ferenbach

MRC Centre for Inflammation Research

University of Edinburgh

Renal Ischaemia Reperfusion Injury: A Mouse Model of Injury and Regeneration