Protection Of Ischemia-reperfusion Injury Research Articles

Nanoparticle targeting of neutrophil glycolysis prevents lung ischemia-reperfusion injury

Neutrophils exacerbate pulmonary ischemia-reperfusion injury (IRI) resulting in poor short and long-term outcomes for lung transplant recipients. Glycolysis powers neutrophil activation, but it remains unclear if neutrophil-specific targeting of this pathway will inhibit IRI. Lipid nanoparticles containing the glycolysis flux inhibitor 2-deoxyglucose (2-DG) were conjugated to neutrophil-specific Ly6G antibodies (NP-Ly6G[2-DG]). Intravenously administered NP-Ly6G(2-DG) to mice exhibited high specificity for circulating neutrophils. NP-Ly6G(2-DG)–treated neutrophils were unable to adapt to hypoglycemic conditions of the lung airspace environment as evident by the loss of demand-induced glycolysis, reductions in glycogen and ATP content, and an increased vulnerability to apoptosis. NP-Ly6G(2-DG) treatment inhibited pulmonary IRI following hilar occlusion and orthotopic lung transplantation. IRI protection was associated with less airspace neutrophil extracellular trap generation, reduced intragraft neutrophilia, and enhanced alveolar macrophage efferocytotic clearance of neutrophils. Collectively, our data show that pharmacologically targeting glycolysis in neutrophils inhibits their activation and survival leading to reduced pulmonary IRI.

Effects of Recombinant Human Erythropoietin and 2-Mercaptoethane Sulfonate on Liver Ischemia-Reperfusion Injury in Rats.

The aim of this study was to determine the effects of recombinant human erythropoietin and 2-merkaptoethane sulfonate, administered in combination, on the biochemical and histopathological changes of ischemia-reperfusion injury. Fifty female Wistar Albino rats were used in this study. The animals were randomly divided into 5 groups: a sham group that underwent standard laparotomy only, an ischemia-reperfusion group that was subjected to 30 minutes of hepatic ischemia and 2 hours of reperfusion, a group that intraperitoneally received 1000 IU/kg recombinant human erythropoietin 5 minutes before ischemiareperfusion, a group that intraperitoneally received 150 mg/kg 2-merkaptoethane sulfonate 15 minutes before ischemia-reperfusion, and a combined group that received both drugs intraperitoneally before ischemia-reperfusion. After the reperfusion period, serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and malondialdehyde levels were measured. We also evaluated histological changes in rat liver tissues samples. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and malondialdehyde levels were high in the control groups, but aspartate and alanine aminotransferase levels were within normal limits, especially in rats that only received recombinant human erythropoietin. In rats that received combined treatment, parenchymal alterations in liver tissue were less severe than in the other groups and necrosis did not occur. Recombinant human erythropoietin was clearly more effective than 2-merkaptoethane sulfonate for preventing oxidative injury. When the agents were combined, obvious biochemically and histologically protective effects occurred, providing significant tissue protection in ischemia-reperfusion injury.

Chronic estradiol exposure - harmful effects on behavior, cardiovascular and reproductive functions.

Estradiol (E2) is a female hormone that is produced largely by the ovaries, but also by the adrenal glands, fat and liver. It is present in the circulation of both males and females. Many studies in the literature have described how E2 is beneficial to the body in terms of preventing bone loss, affording protection in ischemia reperfusion injury, relieving symptoms of menopause, maintaining vaginal health and helping with ovarian failure or hypogonadism. Beneficial effects on the brain have been reported to include protection against memory loss, neuronal degeneration, changes in cognition, mood and behavior. However, the effects of E2 exposure on the neuroendocrine system have not been understood completely. This is because differences in doses, preparation and duration of exposure have produced variable results ranging from beneficial, to no change, or to detrimental. Studies in our lab over the last few years have shown that chronic exposures to low levels of E2 in young rats can produce specific effects on the neuroendocrine system. We have observed that these exposures can induce reproductive senescence, hypertension, anxiety-like behavior and cause degenerative changes in specific neuronal populations leading to hyperprolactinemia. The purpose of the review is to present evidence from the literature for these effects and to discuss the underlying molecular mechanisms.

Effects of remote ischemic preconditioning and topical hypothermia in renal ischemia-reperfusion injury in rats.

To evaluate whether combining hypothermia and remote ischemic preconditioning (RIPC) results in protection from ischemia-reperfusion (IR). Thirty-two Wistar rats underwent right nephrectomy and were randomly assigned to four experimental protocols on the left kidney: warm ischemia (group 1), cold ischemia (group 2), RIPC followed by warm ischemia (group 3), and RIPC followed by cold ischemia (group 4). After 240 minutes of reperfusion, histological changes in the left kidney, as well as lipid peroxidation and antioxidant enzyme activity, were analyzed. The right kidney was used as the control. Serum creatinine was collected before and after the procedures. RIPC combined with hypothermia during IR experiments revealed no differences on interventional groups regarding histological changes (p=0.722). Oxidative stress showed no significant variations among the groups. Lower serum creatinine at the end of the procedure was seen in animals exposed to hypothermia (p<0.001). Combination of RIPC and local hypothermia provides no renal protection in IR injury. Hypothermia preserves renal function during ischemic events. Furthermore, RIPC followed by warm IR did not show benefits compared to warm IR alone or controls in our experimental protocol.

Effect of heme oxygenase-1 on the protection of ischemia reperfusion injury of bile duct in rats after liver transplantation

To investigate the effect of heme oxygenase-1 (HO-1) on the ischemic reperfusion injury (IRI) of bile duct in rat models after liver transplantation. 320 SD rats were equally and randomly divided into 5 groups, which were group A receiving injection of 3×108/pfu/ml adenovirus (adv), group B with donor receiving Adv-HO-1 and recipient receiving Adv-HO-1-siRNA, group C with donor and recipient both receiving Adv-HO-1, group D with donor receiving Adv-HO-1-siRNA and recipient receiving Adv-HO-1, and group E with donor and recipient both receiving Adv-HO-1-siRNA at 24h before liver transplantation. Donor liver was stored in UW liquid at 4°C followed by measuring HO-1 level by western blot before transplantation. On d1, d3, d7 and d14, serum and liver was isolated for analysis of liver function, inflammatory cell infiltration by H&E staining, ultrastructure of liver by transmission electron microscopy as well as the expression of HO-1, Bsep, Mrp2 and Ntcp by western blot. Compared with group D and E, group B and C displayed improved liver function as demonstrated by lower level of ALT, AST, LDH, TBIL, ALP and GGT, increased secretion of TBA and PL as well as expression of transporter proteins (Bsep, Mrp2 and Ntcp), reduced inflammatory cells infiltration and liver injury. Our study demonstrated that overexpression of HO-1 in donor liver can ameliorate the damage to bile duct and liver, and improved liver function, suggesting HO-1 might be a new therapeutic target in the treatment of IRI after liver transplantation.

Retraction note: Microarray analysis for differentially expressed genes of patients undergoing total knee arthroplasty with ischemia preconditioning.

Ischemia preconditioning (IPC) has been proved as a powerful method of protecting tissues against ischemia reperfusion insults. We aimed to elucidate the mechanism of IPC in ischemia reperfused tissues. GSE21164 containing 16 muscle biopsies taken from the operative knee of four IPC-treated patients and four control at the onset of surgery (T = 0) and 1 h into surgery (T = 1) undergoing primary total knee arthroplasty was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between IPC group and control were screened with Limma package in R language. KEGG pathway enrichment analysis was performed by the DAVID online tool. Meanwhile, potential regulatory microRNAs (miRNAs) for downregulated DEGs and targets of transcription factors for upregulated DEGs were screened out. Based on the above DEGs, protein-protein interaction (PPI) networks were constructed by the STRING software. Significantly upregulated DEGs at T1 were mainly enriched in asthma and p53 signaling pathway. Meanwhile, significantly enriched transcriptional factor NOTCH1 at T1 and GABP at T0 were obtained. Moreover, miRNA analysis showed that targets of miR141/200a were enriched in downregulated DEGs both at T0 and T1. Mostly, RPA1 and JAK2 in PPI network at T1 were with higher degree. In our study, obtained DEGs, regulatory transcriptional factors, and miRNA might play a vital role in the protection of ischemia reperfusion injury. This finding will provide a deeper understanding to the mechanism of IPC.

Protective function of tocilizumab in human cardiac myocytes ischemia reperfusion injury.

To investigate the protective function of tocilizumab in human cardiac myocytes ischemia-reperfusion injury. The human cardiac myocytes were treated by tocilizumab with different concentrations(1.0 mg/mL, 3.0 mg/mL, 5.0 mg/mL) for 24 h, then cells were cultured in ischemia environment for 24 h and reperfusion environment for 1 h. The MTT and flow cytometry were used to detect the proliferation and apoptosis of human cardiac myocytes, respectively. The mRNA and protein expressions of Bcl-2 and Bax were measured by qRT-PCR and western blot, respectively. Compared to the negative group, pretreated by tocilizumab could significantly enhance the proliferation viability and suppress apoptosis of human cardiac myocytes after suffering ischemia reperfusion injury (P<0.05). The expression of Bcl-2 in tocilizumab treated group were higher than NC group (P<0.05), while the Bax expression were lower (P<0.05). Tocilizumab could significantly inhibit apoptosis and keep the proliferation viability of human cardiac myocytes after suffering ischemia reperfusion injury. Tocilizumab may obtain a widely application in the protection of ischemia reperfusion injury.

Medicinal Chemistry: Insights into the Development of Novel H2S Donors.

Hydrogen sulfide (H2S) was traditionally considered as a toxic gas. However, recent studies have demonstrated H2S is an endogenously generated gaseous signaling molecule (gasotransmitter) with importance on par with that of two other well-known endogenous gasotransmitters, nitric oxide (NO) and carbon monoxide (CO). Although H2S's exact mechanisms of action are still under investigation, the production of endogenous H2S and the exogenous administration of H2S have been demonstrated to elicit a wide range of physiological responses including modulation of blood pressure and protection of ischemia reperfusion injury, exertion of anti-inflammatory effects, and reduction of metabolic rate. These results strongly suggest that modulation of H2S levels could have potential therapeutic values. In this regard, synthetic H2S-releasing agents (i.e., H2S donors) are not only important research tools, but also potential therapeutic agents. This chapter summarizes the knowledge of currently available H2S donors. Their preparation, H2S releasing mechanisms, and biological applications are discussed.

Microarray analysis for differentially expressed genes of patients undergoing total knee arthroplasty with ischemia preconditioning.

BackgroundIschemia preconditioning (IPC) has been proved as a powerful method of protecting tissues against ischemia reperfusion insults. We aimed to elucidate the mechanism of IPC in ischemia reperfused tissues.MethodsGSE21164 containing 16 muscle biopsies taken from the operative knee of four IPC-treated patients and four control at the onset of surgery (T = 0) and 1 h into surgery (T = 1) undergoing primary total knee arthroplasty was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between IPC group and control were screened with Limma package in R language. KEGG pathway enrichment analysis was performed by the DAVID online tool. Meanwhile, potential regulatory microRNAs (miRNAs) for downregulated DEGs and targets of transcription factors for upregulated DEGs were screened out. Based on the above DEGs, protein-protein interaction (PPI) networks were constructed by the STRING software.ResultsSignificantly upregulated DEGs at T1 were mainly enriched in asthma and p53 signaling pathway. Meanwhile, significantly enriched transcriptional factor NOTCH1 at T1 and GABP at T0 were obtained. Moreover, miRNA analysis showed that targets of miR141/200a were enriched in downregulated DEGs both at T0 and T1. Mostly, RPA1 and JAK2 in PPI network at T1 were with higher degree.ConclusionsIn our study, obtained DEGs, regulatory transcriptional factors, and miRNA might play a vital role in the protection of ischemia reperfusion injury. This finding will provide a deeper understanding to the mechanism of IPC.

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

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.

428: Lipopolysaccharide preconditioning is protective in lung ischemia reperfusion injury

Purpose: In lung transplantation, donor lungs are procured from ventilated patients who are frequently colonized with bacteria. How bacterial colonization influences subsequent ischemia-reperfusion injury and graft function is poorly understood. Exposure to bacterial products at sufficient levels can cause lung injury. However, recent work in other organ systems suggests that low-dose lipopolysaccharide (LPS) pretreatment may confer protection in ischemia-reperfusion injury through replication of ischemic preconditioning responses.

Involvement of potassium channel in hemin-induced cardioprotection in rat hearts

To investigate the effects of heme oxygenase 1 inducer hemin on protection of ischemia-reperfusion injury in rats and its mechanisms. The Langendorff model of isolated rat heart was used; the left anterior descending coronary artery was occluded for 30 min and subsequently reperfused for 2 h. Then the ventricular function and infarct size were measured. Hemin preconditioning prevented the increase in LVEDP, decrease in LVDP and +/- dp/dt(max) in the isolated ischemia-reperfusion rat hearts. The leakage of LDH and CK in the coronary effluent was significantly declined in hemin-treated rat hearts. And the infarct size was also reduced. Administration of a blocker of mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) 5-HD (5 mg/kg) before hemin preconditioning increased the LVEDP, and reduced the LVDP and +/- dp/dt(max). The leakage of LDH and CK in the coronary effluent and the infarct size were also increased compared with only hemin-treated rat hearts. Pretreatment of the rats with a blocker of sarcolemmal ATP-sensitive potassium channel (sarcK(ATP)) HMR-1098 (6 mg/kg) before hemin preconditioning also abolished the protective effect. Infusion of paxilline (1 micromol/L), a blocker of calcium activated potassium channel (K(Ca)) for 10 min before ischemia/reperfusion led to larger infarct size and poorer myocardial performance as compared with the hemin group. The leakage of LDH and CK in the coronary effluent was also increased. Both mitoK(ATP)and sarcK(ATP)channels activation are required for the delayed cardioprotection induced by hemin. The opening of K(Ca) channels-dependent mechanism may be involved in the protection.

肝虚血再灌流障害におけるウリナスタチン (UTI) 投与の有用性について

肝虚血再灌流障害におけるウリナスタチン (UTI) 投与の有用性について

Role of Cytokines and Chemokines in Renal Ischemia-Reperfusion Injury.

Cytokines and chemokines produced by renal tubular epithelial cells and infiltrated cells are critical factors in inflammatory processes of renal ischemia-reperfusion injury. In vitro studies reveal that renal tubular epithelial cells have the potential to produce diverse cytokines, chemokines and other mediators, such as tumor necrosis factor-alpha, interleukin-1 (IL-1), monocyte chemoattractant protein-1, IL-8, platelet-derived growth factor, regulated upon activation, normal T cell expressed and secreted, endothelin-1 and vascular endothelial growth factor (VEGF). Huge numbers of in vivo studies show that cytokines, chemokines and adhesion molecules in diseased kidney together govern critical aspects of ischemia-reperfusion injury. Leukocyte­endothelial cell interactions are critical processes of leukocytic infiltration, which are pathologically key factors in inflammatory processes of renal ischemia-reperfusion injury. Leukocyte­endothelial interactions are regulated by a cascade of molecular steps of cytokines, chemokines and adhesion molecules. In contrast, the intracellular cascades of cytokine and chemokine expression in the renal ischemia-reperfusion injury remain to be investigated. p38 mitogen-activated protein kinase is one of the essential mediators in cytokine and chemokine expression through the activation of nuclear factor-kappaB and activating protein-1. Moreover, hypoxia-inducible factor-1 (HIF-1) is a transcription factor activated by reductions in oxygen concentration. HIF-1­related gene expression, such as erythropoietin or VEGF, results in protection of ischemia reperfusion injury. This review focuses on the contribution of cytokines, chemokines and their related molecules to the inflammatory cascade in renal ischemia-reperfusion injury. (c) 2002 Prous Science. All rights reserved.

Protection of Ischemia-Reperfusion Injury by Sydnonimine NO Donors via Inhibition of Neutrophil-Endothelium Interaction

Ischemia of a vascular bed followed by re-establishment of blood flow results in an accelerated and severe form of tissue injury known as “reperfusion injury.” We have investigated reperfusion injury in cats subjected to either myocardial ischemia-reperfusion or splanchnic ischemia-reperfusion. In both cases, a critical early event after reperfusion is endothelial dysfunction characterized by reduced release of endothelium-derived relaxing factor now known to be nitric oxide (NO). Endothelial dysfunction leads to adherence of polymorphonuclear (PMN) leukocytes to the dysfunctional endothelium. Infusion of a sydnonimine NO donor (C87–3754), but not a similar compound lacking the NO moiety (C88–3934), just before reperfusion protected in both forms of ischemia-reperfusion. In the first case, C87–3754, but not C88–3934, attenuated myocardial necrosis, and in the second case, the NO donor improved survival and moderated the indices of shock. In both cases, C87–3754 preserved the endothelium of the ischemic-reperfused vasculature and exerted anti-PMN effects (i.e., reduced PMN adherence to the endothelium or attenuated PMN release of superoxide radicals). Thus, an NO donor infused at a rate calculated to replace the lost NO from the vascular endothelium of the ischemic region exerts significant protective effects on reperfusion of that ischemic vascular bed.

Protection of Ischemia-Reperfusion Injury by Sydnonimine NO Donors via Inhibition of Neutrophil-Endothelium Interaction

Ischemia of a vascular bed followed by reestablishment of blood flow results in an accelerated and severe form of tissue injury known as "reperfusion injury." We have investigated reperfusion injury in cats subjected to either myocardial ischemia-reperfusion or splanchnic ischemia-reperfusion. In both cases, a critical early event after reperfusion is endothelial dysfunction characterized by reduced release of endothelium-derived relaxing factor now known to be nitric oxide (NO). Endothelial dysfunction leads to adherence of polymorphonuclear (PMN) leukocytes to the dysfunctional endothelium. Infusion of a sydnonimine NO donor (C87-3754), but not a similar compound lacking the NO moiety (C88-3934), just before reperfusion protected in both forms of ischemia-reperfusion. In the first case, C87-3754, but not C88-3934, attenuated myocardial necrosis, and in the second case, the NO donor improved survival and moderated the indices of shock. In both cases, C87-3754 preserved the endothelium of the ischemic-reperfused vasculature and exerted anti-PMN effects (i.e., reduced PMN adherence to the endothelium or attenuated PMN release of superoxide radicals). Thus, an NO donor infused at a rate calculated to replace the lost NO from the vascular endothelium of the ischemic region exerts significant protective effects on reperfusion of that ischemic vascular bed.