Increased severity of renal ischemia-reperfusion injury with venous clamping compared to arterial clamping in a rat model (original) (raw)

Neutrophil CD11b upregulation during cardiopulmonary bypass is associated with postoperative renal injury

The Annals of Thoracic Surgery, 2003

Renal injury remains a persistent complication of cardiopulmonary bypass (CPB) that, when sufficient to require dialysis, increases mortality eight-fold. The high prevalence of renal failure in sepsis and adult respiratory distress syndrome has been linked to the systemic inflammatory response associated with those disorders. We hypothesized that components of the inflammatory response to CPB may similarly contribute to post-CPB acute renal injury. Markers of leukocyte and platelet activation peri-CPB were measured in 75 patients undergoing cardiac operation with CPB and were correlated with acute renal injury, defined as an increase (> or = 50%) in peak serum creatinine post-CPB. Eleven patients sustained post-CPB acute renal injury. This subset of patients demonstrated significantly greater increases in neutrophil CD11b density (p = 0.01), as well as higher total neutrophil counts (p = 0.045), compared with patients with preserved renal function. Hemodynamic instability sufficient to require postoperative hemodynamic support also predicted an increased risk of acute renal injury. However, neutrophil CD11b upregulation did not correlate with this or any other clinical variables associated with renal risk, suggesting that this marker of the neutrophil inflammatory response may independently predict renal injury. By contrast other inflammatory markers, neutrophil myeloperoxidase levels, monocyte CD11b, base line C-reactive protein, and platelet CD62P expression did not differ between the two patient groups. Upregulation of the neutrophil adhesion receptor CD11b and high circulating neutrophil numbers are associated with acute renal injury after CPB, suggesting a contribution by activated neutrophils to the pathophysiology of this complication.

Macrophages Expressing Heme Oxygenase-1 Improve Renal Function in Ischemia/Reperfusion Injury

Molecular Therapy, 2010

Acute kidney injury has a high mortality and lacks specific therapies, with ischemia/reperfusion injury (IRI) being the predominant cause. Macrophages (MΦ) 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 MΦ 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 MΦ (BMDM). In vitro Ad-HO-1 MΦ showed an anti-inflammatory phenotype with increased phagocytosis of apoptotic cells (ACs) and increased interleukin (IL)-10 but reduced TNF-α and nitric oxide (NO) following lipopolysaccharide/interferon-γ (IFNγ) stimulation compared to control transduced or unmodified MΦ. In vivo, intravenously (IV) injected MΦ 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 MΦ resulted in preserved renal function (serum creatinine reduced by 46%), and reduced microvascular platelet deposition. These data demonstrate that genetically modified MΦ 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.

Prolonged Kidney Ischemia-Reperfusion Injury Associates with Inflammation, Vascular Remodelling, and Myofibroblast Formation

Journal of the Medical Sciences, 2018

Prolonged kidney ischemia-reperfusion injury (IRI) is the important risk factor for leading to chronic kidney disease (CKD). Persistent hypoxia and inflammation are considered as the main pathogenesis of chronic injury, followed by myofibroblast expansion and fibrosis process. Tubular injury, cell proliferation, and vasoconstriction, as acute compensatory responses, are restored in chronic phase. The aim of the study was to investigate the relation between inflammation, vascular remodeling, and myofibroblast formation as response to ischemia injury after prolonged kidney ischemia-reperfusion (I/R). Fifteen male Swiss mice aged 3-4 months were used as kidney I/R injury model after bilateral pedicle renal clamping. Rats were divided into 3 groups with five rats in each group i.e. control group (sham operation/SO), acute I/R model (IR1), and chronic I/R model (IR12). PAS staining was used for scoring tubular injury. Fibrosis was assessed using sirius red and a-SMA immunostaining for myofibroblast expansion. PCNA and CD68 immunostaining were used for identifying cell proliferation and macrophage infiltration. RT-PCR was conducted for assessing MCP-1, HIF-1a, and ppET-1 expression, which were quantified using ImageJ software. Data were analyzed using one way ANOVA and Kruskal-Wallis test with significance level of p<0.05. Significantly increase of tubular injury score (p<0.001) and PCNA positive cell (p<0.001) in IR1 group compared to SO were observed, otherwise HIF-1a of IR12 enhanced (p<0.05). Macrophage cell count (p<0.01) and MCP-1 expression (p<0.05), were significantly increase in IR1 and IR12 injury, compared to SO. Wall thickness of arteries was significantly increase (p<0.05) as well as decrease of vascular lumen area (p<0.05), followed by enhancement of ppET-1 expression (p<0.01) in IR1 group and restored significantly (p<0.05) in IR12 group. Fibrosis fraction-area and myofibroblast expansion were significantly increase gradually from IR1 to IR12 injury (p<0.01). In conclusion, prolonged kidney I/R injury induces the sustainability of hypoxia and inflammatory response, which promotes myofibroblast formation, and decrease the response of vascular remodelling.

Macrophage depletion reduces monocyte chemotactic protein-1 and transforming growth factor-β1 in healing rat vein grafts

Journal of Vascular Surgery, 2004

We previously showed that treatment with liposomally encapsulated dichloromethylene bisphosphonate reduces intimal hyperplasia development and macrophage accumulation in a rat epigastric vein to femoral artery model of intimal hyperplasia. Our objective in this study was to determine the effect of liposomally encapsulated dichloromethylene bisphosphonate on the expression of two cytokines essential to neointimal development, monocyte chemotactic protein-1 (MCP-1) and transforming growth factor-␤ 1 (TGF-␤). Methods: We injected rats both 2 days preoperatively and 2 weeks postoperatively with liposomally encapsulated dichloromethylene bisphosphonate (Lip-Clod), liposomally encapsulated phosphate-buffered saline solution (Vector), or phosphate-buffered saline solution (PBS), and harvested the grafts at 1 and 4 weeks. In the perianastomotic region, MCP-1 and TGF-␤ protein expression in the total graft cross-section and in the neointima was determined with immunohistochemistry. In whole-graft lysates, MCP-1 and TGF-␤ protein were determined with an enzyme-linked immunosorbent assay, and messenger RNA expression was determined with reverse transcription quantitative polymerase chain reaction. Results: Lip-Clod treatment reduced intimal hyperplasia when compared with Vector or PBS treatment. These reductions were significant (P < .05) at both time points. When compared with the PBS treatment, at 1 week but not at 4 weeks Lip-Clod reduced both MCP-1 and TGF-␤ protein (P < .01 and P < .006) in the perianastomotic region of vein grafts.

Reduction of activated macrophages after ischaemia-reperfusion injury diminishes oxidative stress and ameliorates renal damage

Nephrology Dialysis Transplantation, 2012

Background. Macrophages are major effectors of the local inflammatory response syndrome (LIRS) and influence the extent of ischaemia/reperfusion injury, thereby impacting organ function. Several subgroups of macrophages exist, representing distinct modes of action. The specific role of the subset expressing Fc gamma receptor (FcγR) 1 in the activated state of macrophages is poorly defined. Methods. We induced a LIRS via 30 min of ischaemia in uninephrectomized rats, transgenic for the human FcγR1. Six hours after reperfusion, the treatment group was injected with a recombinant immunotoxin (IT) H22(scFv)-ETA' targeted against human FcγR1, which induced apoptosis of target cells. The placebo group received normal saline (NS). Contralateral kidneys served as healthy controls (Ctr). After 24 h of reperfusion, the animals were analysed. Results. Targeted treatment with IT resulted in preserved renal function [NS versus IT treatment and baseline (creatinine: 69.2 ± 2.6, 54.7 ± 3.4 and 27.3 ± 1.0 μmol/L; P < 0.001)]. The number of all infiltrating monocytes were significantly reduced (CD68-positive cells per view field: NS 3.8 ± 0.4, IT 2.5 ± 0.2 and Ctr 1.2 ± 0.4; P < 0.05), renal histology improved and there was a reduced expression of renal fibronectin (NS 4.0 ± 0.4, IT 2.3 ± 0.2 and Ctr 1.1 ± 0.1; P < 0.001). Following IT administration, we also observed less expression of renal monocyte chemoattractant protein-1-positive cells per view field (NS 19.0 ± 1, IT 10.1 ± 0.8 and Ctr 2.0 ± 0.3; P < 0.001) as well as reduced systemic and local oxidative stress [serum malondialdehyde (MDA): NS 340 ± 30, IT 224 ± 36 versus baseline 140 ± 5 nmol/mL; P < 0.01]; renal MDA arbitrary units of fluorescence intensity: NS 3.7 ± 0.2, IT 1.8 ± 0.3 and Ctr 0.4 ± 0.2; P < 0.001. Conclusions. Reduction of FcγR1-up-regulated monocytic cells leads to preserved renal function and morphology in a rat model of ischaemia-triggered LIRS. Our results show that targeting activated macrophages is a valuable approach for ameliorating ischaemia-induced tissue injury.

Local cellular inflammation as a result of elective standardized vascular surgery

Acta Histochemica, 2001

During surgery, incision of the skin under aseptic conditions is performed. Despite the absence of noxious agents, an inflammatory response may be induced. We studied the local inflammatory response in human skin as a result of surgical intervention, under aseptic conditions. Elective standardized vascular surgery served as a model. A series of skin biopsies was taken from the wound edge at different time points after first incision. Biopsies, directly taken at first incision were considered to represent normal skin. Additional biopsies were taken at 30 min after the start of surgery and just before closure of the wound, maximally 270 min after surgery. Kinetics of recruitment of cells, expression of adhesion molecules and the presence of pro-inflammatory cytokines was studied. Granulocytes were observed at first at 30 min after incision of the skin and their number increased in time. This granulocyte infiltration is paralleled by E-selectin expression on endothelial cells, which also was observed at first at 30 min after surgery with a further increase in number in time. Incision of the skin did not change P-selectin, ICAM-1, VCAM-1, TNFa, IL1a, IL1b, IL6 and IL8 expression. These results show that incision of the skin under aseptic conditions during elective standardized vascular surgery induces local nonspecific cellular inflammation.

Inflammatory events in a vascular remodeling model induced by surgical injury to the rat carotid artery

British Journal of Pharmacology, 2006

The aim of our study was to gain insight into the molecular and cellular mechanisms of the inflammatory response to arterial injury in a rat experimental model.Rats (five for each experimental time) were subjected to brief clamping and longitudinal incision of a carotid artery and monitored for 30 days. Subsequently, Nuclear Factor-kappaB (NF-κB) expression was measured by electrophoretic mobility shift assay. Heat shock protein (HSP) 27, HSP47 and HSP70 were evaluated by Western blot. Morphological changes of the vessel wall were investigated by light and electron microscopy.In injured rat carotid artery NF-κB activity started immediately upon injury, and peaked between 2 and 3 weeks later. Western blot showed a significant increase of HSP47 and HSP70 7 days after injury. At 2 weeks postinjury, HSP27 expression peaked. Ligth microscopy showed a neointima formation, discontinuity of the media layer and a rich infiltrate. Among infiltrating cells electron microscopy identified dendritic-like cells in contact with lymphocytes.Our model of surgical injury induces a significant inflammatory process characterized by enhanced NF-κB activity and HSPs hyperexpression. Dendritic-like cells were for the first time identified as a novel component of tissue repair consequent to acute arterial injury.The aim of our study was to gain insight into the molecular and cellular mechanisms of the inflammatory response to arterial injury in a rat experimental model.Rats (five for each experimental time) were subjected to brief clamping and longitudinal incision of a carotid artery and monitored for 30 days. Subsequently, Nuclear Factor-kappaB (NF-κB) expression was measured by electrophoretic mobility shift assay. Heat shock protein (HSP) 27, HSP47 and HSP70 were evaluated by Western blot. Morphological changes of the vessel wall were investigated by light and electron microscopy.In injured rat carotid artery NF-κB activity started immediately upon injury, and peaked between 2 and 3 weeks later. Western blot showed a significant increase of HSP47 and HSP70 7 days after injury. At 2 weeks postinjury, HSP27 expression peaked. Ligth microscopy showed a neointima formation, discontinuity of the media layer and a rich infiltrate. Among infiltrating cells electron microscopy identified dendritic-like cells in contact with lymphocytes.Our model of surgical injury induces a significant inflammatory process characterized by enhanced NF-κB activity and HSPs hyperexpression. Dendritic-like cells were for the first time identified as a novel component of tissue repair consequent to acute arterial injury.British Journal of Pharmacology (2006) 147, 175–182. doi:10.1038/sj.bjp.0706472

Leukocyte recruitment and expression of chemokines following different forms of vascular injury

Vascular Medicine, 2003

Inflammation plays a central role in restenosis following coronary intervention. Recent human and animal data suggest important differences between the inflammatory responses to simple balloon angioplasty compared with stent implantation. To investigate the mechanisms of these differences, New Zealand white rabbits underwent bilateral iliac artery balloon denudation. Half received intravascular stents. Arteries were harvested at three, seven and 14 days for immunohistochemistry, and 4 hours, 8 hours and 14 days for chemokine mRNA analysis. Leukocyte content was quantifi ed utilizing immunohistochemistry (RPN357, monoclonal antibody (mAb) against rabbit neutrophil; RAM-11, mAb against rabbit macrophage). We analyzed the mRNA levels of the chemokines monocyte chemoattractant protein 1 (MCP-1) and interleukin 8 (IL-8) through semi-quantitative polymerase chain reaction. We demonstrated the spatial pattern of MCP-1 mRNA levels through in situ mRNA hybridization. In balloon-injured arter...