scholarly journals Chronic Reduction in Renal Mass in the Rat Attenuates Ischemia/Reperfusion Injury and Does Not Impair Tubular Regeneration

1999 ◽  
Vol 10 (12) ◽  
pp. 2551-2561
Author(s):  
SVEN R. VERCAUTEREN ◽  
DIRK K. YSEBAERT ◽  
KATHLEEN E. DE GREEF ◽  
ERIK J. EYSKENS ◽  
MARC E. DE BROE

Abstract. It is not known whether a kidney with chronic structural and functional changes is more vulnerable to an acute renal insult, and whether its regeneration capacity after injury is altered. To study this question, Lewis rats were submitted 10 wk after 5/6 nephrectomy to an ischemic insult of 60 min (remnant kidney [RK] group). Functional and morphologic data of the RK group were compared with data obtained in 10-wk uninephrectomized (1K) and normal (2K) Lewis rats with unilateral and bilateral renal ischemia, respectively. The acute postischemic decrease in creatinine clearance was smallest in the RK group, followed by the 2K and 1K groups, respectively. At days 1 and 3, fewer proximal tubules in the outer stripe of the outer medulla of the RK and 2K groups had undergone acute tubular necrosis compared with the 1K group. The mean percentage of tubules with signs of regeneration was maximal at day 3 in the three experimental groups. At day 10, regeneration was almost complete in the three groups. The number of leukocytes (OX1+cells) present in the RK before ischemia did not increase after ischemia/reperfusion injury (377 ± 146 cells/mm2at day 0) in contrast to the 1K and 2K groups. In the latter groups, the number of leukocytes had increased gradually, reaching a maximum at day 15 (1K: 960 ± 308 cells/mm2) and day 10 (2K: 668 ± 164 cells/mm2), respectively. In conclusion, this study has shown that an RK exhibiting chronic morphologic changes of interstitial fibrosis and tubular atrophy is protected against ischemia/reperfusion injury, and that its regeneration capacity is preserved. The reperfusion injury is not followed by further accumulation of leukocytes, which were already present in the RK before ischemia.

2001 ◽  
Vol 12 (12) ◽  
pp. 2691-2700 ◽  
Author(s):  
Ming Yin ◽  
Michael D. Wheeler ◽  
Henry D. Connor ◽  
Zhi Zhong ◽  
Hartwig Bunzendahl ◽  
...  

ABSTRACT. Evidence has accumulated for a role of toxic oxygen radicals in the pathogenesis of ischemia-reperfusion injury in the kidney. The aim of this study was to evaluate the hypothesis that reducing postischemic renal injury is possible by delivery of the gene for the antioxidant enzyme superoxide dismutase (SOD). Female Sprague-Dawley rats received intravenous injections of recombinant adenovirus (1 × 109 pfu) containing the transgenes for Escherichia coli β-galactosidase (Ad-LacZ, as control) or human Cu/Zn-SOD (Ad-SOD). Three days later, renal ischemia was produced by cross-clamping the left renal vessels for 60 min. The right kidney was removed before reperfusion and processed for the transgene. Renal SOD protein and activity in rats given Ad-SOD was 2.5-fold higher than from the animals receiving Ad-LacZ. Urinary lactate dehydrogenase concentrations were elevated by ischemia-reperfusion in the Ad-LacZ group (1403 ± 112 U/L), yet values were 50% lower in Ad-SOD-treated rats. Free radical production was elevated by ischemia-reperfusion but was significantly lower in SOD-treated animals. Importantly, on postischemic day 1, glomerular filtration rates were reduced to 0.21 ml/min per 100 g in the Ad-LacZ group, whereas values remained significantly higher (0.39) in the Ad-SOD group. Two weeks after ischemia-reperfusion, inflammation, interstitial fibrosis, tubular atrophy and tissue levels of tumor necrosis factor alpha and interleukin-1 were significantly higher in the Ad-LacZ-treated than in Ad-SOD-treated rats. In conclusion, these results indicate that SOD expression can be increased by delivery of the sod gene to the kidney by intravenous injection and that sod gene transduction minimized ischemia-reperfusion-induced acute renal failure.


2021 ◽  
Vol 2 (2) ◽  
pp. 191-207
Author(s):  
Davide Loizzo ◽  
Nicola Antonio di Meo ◽  
Mattia Rocco Peluso ◽  
Monica Rutigliano ◽  
Matteo Matera ◽  
...  

Ischemia reperfusion injury (IRI) is one of the most important mechanisms involved in delayed or reduced graft function after kidney transplantation. It is a complex pathophysiological process, followed by a pro-inflammatory response that enhances the immunogenicity of the graft and the risk of acute rejection. Many biologic processes are involved in its development, such as transcriptional reprogramming, the activation of apoptosis and cell death, endothelial dysfunction and the activation of the innate and adaptive immune response. Recent evidence has highlighted the importance of complement activation in IRI cascade, which expresses a pleiotropic action on tubular cells, on vascular cells (pericytes and endothelial cells) and on immune system cells. The effects of IRI in the long term lead to interstitial fibrosis and tubular atrophy, which contribute to chronic graft dysfunction and subsequently graft failure. Furthermore, several metabolic alterations occur upon IRI. Metabolomic analyses of IRI detected a “metabolic profile” of this process, in order to identify novel biomarkers that may potentially be useful for both early diagnosis and monitoring the therapeutic response. The aim of this review is to update the most relevant molecular mechanisms underlying IRI, and also to discuss potential therapeutic targets in future clinical practice.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Joshua G Travers ◽  
Fadia A Kamal ◽  
Michelle L Nieman ◽  
Michelle A Sargent ◽  
Jeffery D Molkentin ◽  
...  

Heart failure is a devastating disease characterized by chamber remodeling, interstitial fibrosis and reduced ventricular compliance. Cardiac fibroblasts are responsible for extracellular matrix homeostasis, however upon injury or pathologic stimulation, these cells transform to a myofibroblast phenotype and play a fundamental role in myocardial fibrosis and remodeling. Chronic sympathetic overstimulation induces excess signaling through G protein βγ subunits and ultimately the pathologic activation of G protein-coupled receptor kinase 2 (GRK2). We hypothesized that Gβγ-GRK2 inhibition plays an important role in the cardiac fibroblast to attenuate pathologic myofibroblast activation and cardiac remodeling. To investigate this hypothesis, mice were subjected to ischemia/reperfusion (I/R) injury and treated with the small molecule Gβγ-GRK2 inhibitor gallein. While animals receiving vehicle demonstrated a reduction in overall cardiac function as measured by echocardiography, mice treated with gallein exhibited nearly complete preservation of cardiac function and reduced fibrotic scar formation. We next sought to establish the cell specificity of this compound by treating inducible cardiomyocyte- and activated fibroblast-specific GRK2 knockout mice post-I/R. Although we observed modest restoration in cardiac function in cardiomyocyte-specific GRK2 null mice, treatment of these mice with gallein resulted in further protection against myocardial dysfunction following injury, suggesting a functional role in other cardiac cell types, including fibroblasts. Activated fibroblast-specific GRK2 knockout mice were also subjected to ischemia/reperfusion injury; these animals displayed preserved myocardial function and reduced collagen deposition compared to littermate controls following injury. Furthermore, systemic Gβγ-GRK2 inhibition by gallein did not appear to confer further protection over activated fibroblast-specific GRK2 ablation alone. In summary, these findings suggest a potential therapeutic role for Gβγ-GRK2 inhibition in limiting pathologic myofibroblast activation, interstitial fibrosis and heart failure progression.


2019 ◽  
Vol 317 (3) ◽  
pp. C525-C533 ◽  
Author(s):  
Yu Tina Zhao ◽  
Jianfeng Du ◽  
Naohiro Yano ◽  
Hao Wang ◽  
Jianguo Wang ◽  
...  

p38-Regulated/activated protein kinase (PRAK) plays a critical role in modulating cellular survival and biological function. However, the function of PRAK in the regulation of myocardial ischemic injury remains unknown. This study is aimed at determining the function of PRAK in modulating myocardial ischemia-reperfusion injury and myocardial remodeling following myocardial infarction. Hearts were isolated from adult male homozygous PRAK−/− and wild-type mice and subjected to global ischemia-reperfusion injury in Langendorff isolated heart perfusion. PRAK−/− mice mitigated postischemic ventricular functional recovery and decreased coronary effluent. Moreover, the infarct size in the perfused heart was significantly increased by deletion of PRAK. Western blot showed that deletion of PRAK decreased the phosphorylation of ERK1/2. Furthermore, the effect of deletion of PRAK on myocardial function and remodeling was also examined on infarcted mice in which the left anterior descending artery was ligated. Echocardiography indicated that PRAK−/− mice had accelerated left ventricular systolic dysfunction, which was associated with increased hypertrophy in the infarcted area. Deletion of PRAK augmented interstitial fibrosis and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive myocytes. Furthermore, immunostaining analysis shows that CD31-postive vascular density and α-smooth muscle actin capillary staining decreased significantly in PRAK−/− mice. These results indicate that deletion of PRAK enhances susceptibility to myocardial ischemia-reperfusion injury, attenuates cardiac performance and angiogenesis, and increases interstitial fibrosis and apoptosis in the infarcted hearts.


2007 ◽  
Vol 104 (18) ◽  
pp. 7576-7581 ◽  
Author(s):  
Masao Kakoki ◽  
Robert W. McGarrah ◽  
Hyung-Suk Kim ◽  
Oliver Smithies

To explore the role of the kallikrein–kinin system in relation to ischemia/reperfusion injury in the kidney, we generated mice lacking both the bradykinin B1 and B2 receptor genes (B1RB2R-null, Bdkrb1−/−/Bdkrb2−/−) by deleting the genomic region encoding the two receptors. In 4-month-old mice, blood pressures were not significantly different among B1RB2R-null, B2R-null (Bdkrb2−/−), and WT mice. After 30 min of bilateral renal artery occlusion and 24 h of reperfusion, mortality rates, renal histological and functional changes, 8-hydroxy-2′-deoxyguanosine levels in total DNA, mtDNA deletions, and the number of TUNEL-positive cells in the kidneys increased progressively in the following order (from lowest to highest): WT, B2R-null, and B1RB2R-null mice. Increases in mRNA levels of TGF-β1, connective tissue growth factor, and endothelin-1 after ischemia/reperfusion injury were also exaggerated in the same order (from lowest to highest): WT, B2R-null, and B1RB2R-null. Thus, both the B1 and B2 bradykinin receptors play an important role in reducing DNA damage, apoptosis, morphological and functional kidney changes, and mortality during renal ischemia/reperfusion injury.


2019 ◽  
Vol 30 (10) ◽  
pp. 1825-1840 ◽  
Author(s):  
Leyuan Xu ◽  
Diana Sharkey ◽  
Lloyd G. Cantley

BackgroundAfter bilateral kidney ischemia/reperfusion injury (IRI), monocytes infiltrate the kidney and differentiate into proinflammatory macrophages in response to the initial kidney damage, and then transition to a form that promotes kidney repair. In the setting of unilateral IRI (U-IRI), however, we have previously shown that macrophages persist beyond the time of repair and may promote fibrosis.MethodsMacrophage homing/survival signals were determined at 14 days after injury in mice subjected to U-IRI and in vitro using coculture of macrophages and tubular cells. Mice genetically engineered to lack Ccr2 and wild-type mice were treated ±CCR2 antagonist RS102895 and subjected to U-IRI to quantify macrophage accumulation, kidney fibrosis, and inflammation 14 and 30 days after the injury.ResultsFailure to resolve tubular injury after U-IRI results in sustained expression of granulocyte-macrophage colony-stimulating factor by renal tubular cells, which directly stimulates expression of monocyte chemoattractant protein-1 (Mcp-1) by macrophages. Analysis of CD45+ immune cells isolated from wild-type kidneys 14 days after U-IRI reveals high-level expression of the MCP-1 receptor Ccr2. In mice lacking Ccr2 and wild-type mice treated with RS102895, the numbers of macrophages, dendritic cells, and T cell decreased following U-IRI, as did the expression of profibrotic growth factors and proimflammatory cytokines. This results in a reduction in extracellular matrix and kidney injury markers.ConclusionsGM-CSF–induced MCP-1/CCR2 signaling plays an important role in the cross-talk between injured tubular cells and infiltrating immune cells and myofibroblasts, and promotes sustained inflammation and tubular injury with progressive interstitial fibrosis in the late stages of U-IRI.


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