RESUMEN
Renal ischaemia-reperfusion injury (RIRI) is a primary cause of acute kidney damage, occurring frequently in situations like renal transplantation, yet the underlying mechanisms were not fully understood. Sentrin-specific protease 1 (SENP1) is an important member of the SENP family, which is widely involved in various diseases. However, the role of SENP1 in RIRI has been unclear. In our study, we discovered that SENP1 was involved in RIRI and reduced renal cell apoptosis and oxidative stress at elevated levels. Further mechanistic studies showed that hypoxia-inducible factor-1α (HIF-1α) was identified as a substrate of SENP1. Furthermore, SENP1 deSUMOylated HIF-1α, which reduced the degradation of HIF-1α, and exerted a renoprotective function. In addition, the protective function was lost after application of the HIF-1α specific inhibitor KC7F2. Briefly, our results fully demonstrated that SENP1 reduced the degradation of HIF-1α and attenuated oxidative stress and apoptosis in RIRI by regulating the deSUMOylation of HIF-1α, suggesting that SENP1 may serve as a potential therapeutic target for the treatment of RIRI.
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Apoptosis , Cisteína Endopeptidasas , Subunidad alfa del Factor 1 Inducible por Hipoxia , Estrés Oxidativo , Daño por Reperfusión , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Animales , Cisteína Endopeptidasas/metabolismo , Cisteína Endopeptidasas/genética , Sumoilación , Riñón/metabolismo , Riñón/patología , Humanos , Masculino , RatonesRESUMEN
Background: Renal ischaemia-reperfusion injury (RIRI) is a common kidney procedure complication due to temporary blood flow interruption, leading to kidney injuries. This study aimed to analyze the effect of metamizole on the levels of interleukin-18 (IL-18), neutrophil-gelatinase-associated lipocalin (NGAL), myeloperoxidase (MPO), and histopathological changes in rats with RIRI. Materials and methods: Animal pre-clinical design study was used. Thirty-two male Wistar rats (Rattus norvegicus) were divided into four groups: negative control, positive control, M100, and M200. Blood samples were collected by intracardiac puncture, followed by bilateral nephrectomy and analyzed histopathologically. Results: Significant difference in IL-18 levels between positive control vs negative control (114.1 + 12.07 vs. 94.0 + 11.4; P = 0.019) and positive control vs M100 (114.1 + 12.07 vs. 86.9 + 8.34; P = 0.007). There was no difference in NGAL. M100 group had the lowest serum MPO levels (14.78+2.01), there was a significant difference in MPO levels in all pairwise analyses. There was a difference in cumulative EGTI scores among the study groups [positive 10.5 (8-11) vs. negative 9 (7-10) vs. M100 9 (7-10) vs. M200 9 (7-11); P = 0.021]. Conclusion: Metamizole 100 mg/kgBW can reduce IL-18 and MPO levels in RIRI, giving more optimal results without affecting NGAL levels. Metamizole administration can reduce cumulative EGTI scores in RIRI, both at doses of 100 mg/kgBW and 200 mg/kgBW. This study shows that Metamizole can be used to prevent kidney injury caused by RIRI. IL-18 and MPO can be biomarkers in predicting kidney injury in RIRI.
RESUMEN
Renal ischaemia-reperfusion (RI/R) injury is one major pathological state of acute kidney injury (AKI) with a mortality rate ranking 50% to 80%. MiR-144-5p acts as a molecular trigger in various diseases. We presumed that miR-144-5p might be involved RI/R injury progression. We found that RI/R injury decreased miR-144-5p expression in rat models. MiR-144-5p downregulation promoted cell apoptosis rate and activated Wnt/ß-catenin signal in RI/R injury rats. By performing bioinformatic analysis, RIP, RNA pull-down, luciferase reporter experiments, we found that circ-AKT3 sponged to miR-144-5p and decreased its expression in RI/R injury rats. Moreover, we found that circ-AKT3 promoted cell apoptosis rate and activated Wnt/ß-catenin signal, and miR-144-5p mimic reversed the promotive effect of circ-AKT3 in rat models. We also found that circ-AKT3 increased the oxidative stress level in rat models. In conclusion, our study suggests that the circAKT3 is involved RI/R injury progression through regulating miR-144-5p/Wnt/ß-catenin pathway and oxidative stress.
Asunto(s)
MicroARNs , Daño por Reperfusión , Animales , Apoptosis/genética , MicroARNs/metabolismo , Estrés Oxidativo/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Circular/genética , Ratas , Daño por Reperfusión/genética , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
NEW FINDINGS: What is the central question of this study? What is the role of circulating exosomal miR-687 in remote hepatic injury following renal ischaemia-reperfusion injury (IRI) and does thymoquinone have a modulatory impact? What is the main finding and its importance? Exosomal miR-687 was expressed in renal IRI, entered the circulation and was deposited in the liver. Liver exosomal miR-687 was correlated with liver inflammation and apoptosis. Thymoquinone aborted the renal production of exosomal miR-687 and its further circulation to the liver. ABSTRACT: The pathophysiology of remote hepatic injury following acute renal ischaemia-reperfusion injury (IRI) is of particular clinical interest. Secreted small non-coding microRNA (miRs) are thought to exist in exosome-encapsulated form. Thymoquinone (TQ) is the main bioactive ingredient of Nigella sativa and has several renoprotective actions. We expected exosomal miR-687 to be relevant as it could act as a humoral mediator, with possible modulation by TQ. Thirty adult male Wister albino rats were assigned to three groups (n = 10); (1) sham-operated, (2) renal ischaemia-reperfusion injury (IRI), and (3) renal IRI pre-treated with TQ 10 mg/kg/day i.v. (TQ-IRI) for 10 days in addition to a dose administered at reperfusion onset. Following 24 h of reperfusion, the IRI group showed renal tissue hypoxia-inducible factor upregulation (P < 0.001). Electron microscopy images of exosomes and analysis of miR-687 revealed elevated levels, which appeared in the circulation. Large amounts of exosomal miR-687 were transmitted to the liver tissue. In the IRI group, liver transaminases (alanine aminotransferase, aspartate aminotransferase) were markedly (P < 0.001) elevated. The hepatic tissue inflammatory markers (vascular cell adhesion molecule-1, myeloperoxidase, monocyte chemotactic protein-1 and nuclear factor-κB) were upregulated (P < 0.001) accompanied with elevated caspase-3. TQ suppressed (P < 0.001) the renal expression and release of exosomal miR-687 into the circulation and its further deposition in the liver tissue; consequently, TQ diminished (P < 0.001) liver tissue inflammation and cellular apoptosis. The results were confirmed by histological tissue assessment. In conclusion, exosomal miR-687 liberated from injured renal tissues into the circulation may be an important factor in inducing remote hepatic injury. Exosomal miR-687 inhibition by TQ protected both renal and hepatic tissues from injury.
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Lesión Renal Aguda , MicroARNs , Daño por Reperfusión , Lesión Renal Aguda/tratamiento farmacológico , Lesión Renal Aguda/metabolismo , Animales , Benzoquinonas , Isquemia/metabolismo , Hígado/metabolismo , Masculino , MicroARNs/genética , MicroARNs/metabolismo , Ratas , Reperfusión , Daño por Reperfusión/metabolismoRESUMEN
Renal ischaemia/reperfusion (I/R) injury may induce kidney damage and dysfunction, in which oxidative stress and apoptosis play important roles. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are reported to be closely related to renal I/R, but the specific molecular mechanism is still unclear. The purpose of this research was to explore the regulatory effect of lncRNA TUG1 on oxidative stress and apoptosis in renal I/R injury. This research revealed that in renal I/R injury and hypoxia/reperfusion (H/R) injury in vitro, the expression level of lncRNA TUG1 was upregulated, and oxidative stress levels and apoptosis levels were negatively correlated with the expression level of lncRNA TUG1. Using bioinformatics databases such as TargetScan and microRNA.org, microRNA-144-3p (miR-144-3p) was predicted to be involved in the association between lncRNA TUG1 and Nrf2. This study confirmed that the level of miR-144-3p was significantly reduced following renal I/R injury and H/R injury in vitro, and miR-144-3p was determined to target Nrf2 and inhibit its expression. In addition, lncRNA TUG1 can reduce the inhibitory effect of miR-144-3p on Nrf2 by sponging miR-144-3p. In summary, our research shows that lncRNA TUG1 regulates oxidative stress and apoptosis during renal I/R injury through the miR-144-3p/Nrf2 axis, which may be a new treatment target for renal I/R injury.
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Apoptosis/genética , Células Epiteliales/metabolismo , Enfermedades Renales/etiología , Túbulos Renales/metabolismo , MicroARNs/genética , Factor 2 Relacionado con NF-E2/genética , Daño por Reperfusión/etiología , Animales , Biomarcadores , Línea Celular , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Estrés del Retículo Endoplásmico/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Técnicas de Inactivación de Genes , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Masculino , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Estrés Oxidativo/genética , Interferencia de ARN , ARN Largo no Codificante , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Transducción de SeñalRESUMEN
ABSTRACT Objective: We aimed to research that naringin whether protects from renal ischemia/reperfusion induced renal damage in rats. Methods: Twenty-four Wistar albino female rats randomly were divided into three groups: 1) control group, in which the rats were only performed right nephrectomy; 2) a second group received right nephrectomy and left kidney ischemia (1 h) and reperfusion (24 h) group ischemia/reperfusion (I/R); 3) a third group received 50 mg/kg naringin orally once a day for two weeks before ischemia/reperfusion (I/R/N). Expression of cyclooxygenase-2 (COX-2), cytosolic phospholipase A2 (cPLA2), inducible nitric oxide synthase (iNOS), caspase-3, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated x protein (Bax), serum creatinine (Cr), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) were measured by using enzyme-linked immunosorbent assay (ELISA). Results: Naringin-treated rats that performed renal ischemia/reperfusion demonstrated significant decrease in Cr, IL-6 and TNF-α levels when compared to the only renal ischemia/reperfusion performed rats. While renal ischemia/reperfusion caused a decrease of bcl-2 (1.72 ± 0.20 pg/ml) levels, while an increase of COX-2 (11882 ± 642 pg/ml), cPLA2 (2448 ± 139 pg/ml), iNOS (4331 ± 438 IU/ml), cleaved caspase-3 (7.33 ± 0.76 ng/ml) and Bax (2.33 ± 0.44 ng/ml) levels. The treatment of naringin reversed these kidney effects (7.47 ± 60.35 pg/ml; 9299 ± 327 pg/ml; 2001 ± 78 pg/ml; 3112 ± 220 IU/ml; 3.38 ± 0.54 ng/ml; 2.33 ± 0.44 ng/ml, respectively) (p <0.05). Conclusion: This study showed that naringin treatment attenuated renal damage induced by ischemia/reperfusion in rats.
RESUMEN Objetivo: Nuestro objetivo fue investigar si la naringina protege del daño en los riñones provocado por isquemia-reperfusión renal en ratas. Material y métodos: De forma aleatoria, dividimos 24 ratas albinas Wistar hembras en tres grupos: 1) grupo control, en el que solo se les realizó a las ratas una nefrectomía derecha; 2) un segundo grupo isquemia-reperfusión, con nefrectomía derecha e isquemia de riñón izquierdo (1 h) y reperfusión (24 h); 3) un tercer grupo al que se le administró 50 mg/kg de naringina por vía oral una vez al día durante dos semanas antes de la isquemia-reperfusión. Por medio de un ensayo inmunoabsorbente ligado a enzimas (ELISA), se midieron las siguientes expresiones: ciclooxigenasa-2 (COX-2), fosfolipasa citosólica A2 (cPLA2), óxido nítrico sintetasa inducible (ONSi), caspasa-3, linfoma de células B2 (Bcl-2), proteína X asociada a Bcl-2 (Bax), creatinina sérica (Cr), factor de necrosis tumoral alfa (FNT-α) e interleucina 6 (IL-6). Resultados: Las ratas tratadas con naringina por isquemia-reperfusión renal mostraron un descenso significativo en los niveles de Cr, IL-6 y FNT-α en comparación con las ratas a las que se les indujo isquemia-reperfusión renal pero que no se les suministró naringina. La isquemia-reperfusión renal provocó un descenso de los niveles de Bcl-2 (1,72 ± 0,20 pg/ml) y un ascenso en los niveles de COX-2 (11882 ± 642 pg/ml), cPLA2 (2448 ± 139 pg/ml), ONSi (4331 ± 438 UI/ml), caspasa-3 escindida (7,33 ± 0,76 ng/ml) y Bax (2,33 ± 0.,44 ng/ml). El tratamiento con naringina diminuyó estos efectos en el riñón (7,47 ± 60,35 pg/ml; 9299 ± 327 pg/ml; 2001 ± 78 pg/ml; 3112 ± 220 UI/ml; 3.38 ± 0.54 ng/ml; 2.33 ± 0,44 ng/ml, respectivamente) (p <0,05). Conclusión: En este estudio se demostró que el tratamiento con naringina atenuó el daño renal producido por isquemia-reperfusión en ratas.
RESUMEN
Despite extensive research that has been carried out over the past three decades in the field of renal ischaemia-reperfusion (I/R) injury, the pathogenic role of mitochondrial fission in renal I/R injury is poorly understood. The aim of our study is to investigate the molecular mechanism by which mammalian STE20-like kinase 1 (Mst1) participates in renal I/R injury through modifying mitochondrial fission, microtubule cytoskeleton dynamics, and the GSK3ß-p53 signalling pathway. Our data demonstrated that genetic ablation of Mst1 improved renal function, alleviated reperfusion-mediated tubular epithelial cell apoptosis, and attenuated the vulnerability of kidney to I/R injury. At the molecular level, Mst1 upregulation exacerbated mitochondrial damage, as evidenced by reduced mitochondrial potential, increased ROS generation, more cyt-c liberation from mitochondria into the cytoplasm, and an activated mitochondrial apoptotic pathway. Furthermore, we demonstrated that I/R-mediated mitochondrial damage resulted from mitochondrial fission, and the blockade of mitochondrial fission preserved mitochondrial homeostasis in the I/R setting. Functional studies have discovered that Mst1 regulated mitochondrial fission through two mechanisms: induction of Drp1 phosphorylation and enhancement of F-actin assembly. Activated Mst1 promoted Drp1 phosphorylation at Ser616, contributing to Drp1 translocation from the cytoplasm to the surface of the mitochondria. Additionally, Mst1 facilitated F-actin polymerization, contributing to mitochondrial contraction. Finally, we confirmed that Mst1 regulated Drp1 post-transcriptional modification and F-actin stabilization via the GSK3ß-p53 signalling pathway. Inhibition of GSK3ß-p53 signalling provided a survival advantage for the tubular epithelial cell in the context of renal I/R injury by repressing mitochondrial fission. Collectively, our study identified Mst1 as the primary pathogenesis for the development and progression of renal I/R injury via activation of fatal mitochondrial fission by modulating Drp1 phosphorylation, microtubule cytoskeleton dynamics, and the GSK3ß-p53 signalling pathway.
Asunto(s)
Eliminación de Gen , Factor de Crecimiento de Hepatocito/genética , Enfermedades Renales/genética , Enfermedades Renales/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo , Transducción de Señal , Actinas/química , Actinas/metabolismo , Animales , Apoptosis/genética , Línea Celular , Supervivencia Celular , Citoesqueleto/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Enfermedades Renales/patología , Ratones , Mitocondrias/metabolismo , Dinámicas Mitocondriales , Fosforilación , Multimerización de Proteína , Proteínas Serina-Treonina Quinasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/patología , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
AIM: Long non-coding RNA (lncRNAs) have been shown to play a critical role in a variety of pathophysiological processes, such as cell proliferation, apoptosis and migration. However, there were few studies addressing the function of lncRNAs in renal ischaemia/reperfusion (I/R) injury. Apoptosis is an important pathogenesis during I/R injury. Here, we identified the effect of hypoxia-responsive lncRNA growth arrest-specific 5 (GAS5) on apoptosis in renal I/R injury. METHODS: Ischaemia/reperfusion injury in mice or hypoxia/re-oxygenation (H/R) in human proximal renal tubular epithelial cells (HK-2) was practiced to induce apoptosis. The kidneys and blood were collected at 24 h after reperfusion. The GAS5 messenger RNA (mRNA) expression and apoptosis-related gene mRNA and protein levels, including p53, cellular inhibitor of apoptosis protein 2 (cIAP2) and thrombospondin-1 (TSP-1), were analysed. GAS5 small-interfering RNA was transfected with H/R induced cells. Over-expression of GAS5 was performed by plasmid transfection. RESULTS: Apoptotic cells significantly increased in I/R-injured kidneys. GAS5 could be up-regulated in kidneys at 24 h after reperfusion and 3 h after re-oxygenation, combined with increased expression of its downstream apoptosis-related proteins p53 and cIAP2. GAS5 small-interfering RNA treatment down-regulated the mRNA and protein levels of p53 and TSP-1, and attenuated apoptosis induced by H/R in HK-2 cells. Conversely, over-expression of GAS5 up-regulated the mRNA and protein levels of p53 and TSP-1, and promoted apoptosis in HK-2 cells. CONCLUSION: Long non-coding RNA GAS5 induced by I/R injury could promote apoptosis in kidney. TSP-1 might be one of the downstream effectors of GAS5, which will be explored in the future.
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Lesión Renal Aguda/metabolismo , Apoptosis , Túbulos Renales Proximales/metabolismo , ARN Largo no Codificante/metabolismo , Daño por Reperfusión/metabolismo , Lesión Renal Aguda/genética , Lesión Renal Aguda/patología , Animales , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Línea Celular , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Humanos , Túbulos Renales Proximales/patología , Masculino , Ratones Endogámicos C57BL , ARN Largo no Codificante/genética , Daño por Reperfusión/genética , Daño por Reperfusión/patología , Transducción de Señal , Trombospondina 1/genética , Trombospondina 1/metabolismoRESUMEN
BACKGROUND/AIMS: The aim of our study is to investigate the molecular mechanism by which mammalian STE20-like kinase 1 (Mst1) participates in renal I/R injury through modifying mitophagy and the AMPK-YAP signalling pathway. METHODS: WT mice and Mst1-knockout mice were subjected to renal ischaemia-reperfusion (I/R) in vivo. In vitro, the hypoxia-reoxygenation model was used with renal tubular epithelial cells to mimic renal I/R injury. Mitochondrial function was monitored via western blotting and immunofluorescence. Pathway blocker and siRNA knockout technology were used to establish the role of the AMPK-YAP signalling pathway in Mst1-mediated mitochondrial apoptosis in the setting of renal I/R injury. RESULTS: Our data demonstrated that Mst1 expression was upregulated in response to renal I/R injury in vivo, and a higher Mst1 content was positively associated with renal dysfunction and more tubular epithelial cell apoptosis. However, genetic ablation of Mst1 improved renal function, alleviated reperfusion-mediated tubular epithelial cell apoptosis, and attenuated the vulnerability of kidney to I/R injury. In vitro, Mst1 upregulation induced mitochondrial damage including mitochondrial potential reduction, ROS overloading, cyt-c liberation and caspase-9 apoptotic pathway activation. At the molecular levels, I/R-mediated mitochondrial damage via repressing mitophagy and Mst1 suppressed mitophagy via inactivating AMPK signalling pathway and dowregulating OPA1 expression. Re-activation of AMPK-YAP-OPA1 signalling pathway provided a survival advantage for the tubular epithelial cell in the context of renal I/R injury by repressing mitochondrial fission. CONCLUSION: Overall, our results demonstrate that the pathogenesis of renal I/R injury is closely associated with an increase in Mst1 expression and the inactive AMPK-YAP-OPA1 signalling pathway. Based on this, strategies to repress Mst1 expression and activate mitophagy could serve as therapeutic targets to treat kidney ischaemia-reperfusion injury.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Eliminación de Gen , Enfermedades Renales/patología , Mitofagia , Fosfoproteínas/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Daño por Reperfusión/patología , Quinasas de la Proteína-Quinasa Activada por el AMP , Animales , Proteínas de Ciclo Celular , Enfermedades Renales/genética , Enfermedades Renales/metabolismo , Ratones , Ratones Noqueados , Mitocondrias/genética , Mitocondrias/metabolismo , Mitocondrias/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo , Transducción de Señal , Proteínas Señalizadoras YAPRESUMEN
AIM: Upregulation of miR-21 in renal ischaemic preconditioning (IPC) was associated with increased hypoxia inducible factor (HIF)-1α expression. Hypoxic induction of HIF-1α is mediated by inhibition of prolyl hydroxylase domain protein 2 (PHD2) .We hypothesized that miR-21 regulated HIF-1α by targeting PHD2 in the renal IPC. METHODS: Luciferase reporter assay examined if miR-21 target the 3'-untranslated region of PHD2. In vitro, human proximal tubular cell line (HK-2) was incubated in hypoxia or hypoxia/ reoxygenation condition. Kidneys of Mice were respectively subjected to ischaemia/reperfusion injury (IRI) and IPC. Locked nucleic acid (LNA) modified anti-miR-21 was used to knockdown miR-21. Serum creatinine and histological changes estimated the renal injury. Levels of HIF-1α, PHD2, VEGF and miR-21 were examined by western blot or real-time PCR. RESULT: miR-21 targeting of PHD2 was confirmed by 3'-untranslated region reporter assay. miR-21 was significantly upregulated by hypoxia/reoxygenation in HK-2 cell, while PHD2 protein level decreased significantly. LNA anti-miR-21 significantly repressed miR-21 levels and increased the abundance of PHD2. In vivo, IPC upregulated miR-21 expression 24 h after the second ischaemia, while PHD2 expression decreased significantly with upregulation of HIF-1α protein and VEGF mRNA. MiR-21 induced by delayed IPC was effectively inhibited by the LNA anti-miR-21. With downregulation of miR-21, the protection of delayed IPC was attenuated and PHD2 protein was increased. Furthermore, upregulation of HIF-1α and VEGF were abolished after the LNA anti-miR-21 treatment. CONCLUSION: miR-21 could protect kidney against IRI via HIF-1α by inhibiting its target PHD2.The study suggested a new relationship between miR-21 and HIF-1α.
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Prolina Dioxigenasas del Factor Inducible por Hipoxia/metabolismo , Precondicionamiento Isquémico/métodos , Enfermedades Renales/prevención & control , Túbulos Renales Proximales/enzimología , MicroARNs/metabolismo , Daño por Reperfusión/prevención & control , Regiones no Traducidas 3' , Animales , Sitios de Unión , Hipoxia de la Célula , Línea Celular , Modelos Animales de Enfermedad , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Enfermedades Renales/enzimología , Enfermedades Renales/genética , Enfermedades Renales/patología , Túbulos Renales Proximales/patología , Masculino , Ratones Endogámicos C57BL , MicroARNs/genética , Daño por Reperfusión/enzimología , Daño por Reperfusión/genética , Daño por Reperfusión/patología , Transducción de Señal , Factores de Tiempo , Transfección , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
The complement system is an essential component of our innate immunity, both for the protection against infections and for proper handling of dying cells. However, the complement system can also contribute to tissue injury and inflammatory responses. In view of novel therapeutic possibilities, there is an increasing interest in measurement of the complement system activation in the systemic compartment, both in the clinical setting as well as in experimental models. Here we describe in parallel a sensitive and specific sandwich ELISA detecting mouse C3 activation fragments C3b/C3c/iC3b, as well as functional complement ELISAs detecting specific activities of the three complement pathways at the level of C3 and at the level of C9 activation. In a murine model of renal ischaemia/reperfusion injury (IRI) we found transient complement activation as shown by generation of C3b/C3c/iC3b fragments at 24 h following reperfusion, which returned to base-line at 3 and 7 days post reperfusion. When the pathway specific complement activities were measured at the level of C3 activation, we found no significant reduction in any of the pathways. However, the functional complement activity of all three pathways was significantly reduced when measured at the level of C9, with the strongest reduction being observed in the alternative pathway. For all three pathways there was a strong correlation between the amount of C3 fragments and the reduction in functional complement activity. Moreover, at 24 h both C3 fragments and the functional complement activities showed a correlation with the rise in serum creatinine. Together our results show that determination of the systemic pathway specific complement activity is feasible in experimental mouse models and that they are useful in understanding complement activation and inhibition in vivo.
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Activación de Complemento/inmunología , Complemento C3b/inmunología , Complemento C3c/inmunología , Riñón/inmunología , Daño por Reperfusión/inmunología , Animales , Activación de Complemento/genética , Complemento C3b/genética , Complemento C3b/metabolismo , Complemento C3c/genética , Complemento C3c/metabolismo , Complemento C9/inmunología , Complemento C9/metabolismo , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática/métodos , Estudios de Factibilidad , Riñón/irrigación sanguínea , Riñón/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
AIM: Renal ischaemia-reperfusion (I/R) injury, a primary cause of acute renal failure, can induce high morbidity and mortality. This study aimed to explore the effect of erythropoietin on renal I/R injury and its underlying mechanism. METHODS: Fifty male Sprague-Dawley rats were randomly allocated to three groups (n = 10): the sham group, the renal ischaemia-reperfusion-saline (IRI) group, and the IRI+-Erythropoietin (EPO) group. Erythropoietin (250, 500, 1000 U/kg) was intraperitoneally injected 30 min before inducing I/R. Renal I/R injury were induced by clamping the left renal artery for 30 min followed by reperfusion, along with a contralateral nephrectomy. Renal function and histological damage were determined after 24 h reperfusion. The expression of pro-inflammatory cytokines interleukin-6 (IL-6), interleukin-1 ß (IL-1ß), and tumour necrosis factor-α (TNF-α) in the serum and renal tissue were evaluated by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Further, the effects of erythropoietin on PI3K/Akt signalling, erythropoietin receptor (EPOR) and nuclear factor (NF)-κB activation were measured by Western blotting. RESULTS: Erythropoietin pretreatment can significantly decrease the level of renal dysfunction in a dose-dependent manner, attenuated the renal histological changes, the expression of TNF-α, IL-1ß, and IL-6, the levels of reactive oxygen species (ROS) production and NF-κB p65 phosphorylation in renal tissue upon IRI. Moreover, erythropoietin pretreatment could further activate the PI3K/Akt signalling and induced EPOR activity. CONCLUSIONS: Erythropoietin pretreatment could attenuate renal I/R injury by suppressing inflammation, which was associated with activating PI3K/Akt signalling though EPOR activation. Our findings suggest that erythropoietin may be a novel practical strategy to prevent renal I/R injury.