Xanthohumol suppresses inflammatory response to warm ischemia–reperfusion induced liver injury

Liver ischemia/reperfusion (I/R) leads to formation of reactive oxygen species (ROS), which cause hepatic injury and initiate an inflammatory response, which is a critical problem after liver surgery and transplantation. Xanthohumol, the major prenylated chalcone found in hops, has been discussed for its anti-inflammatory and ROS-scavenging properties, and thus, we aimed to investigate the effect of xanthohumol in a model of warm I/R liver injury. Xanthohumol was applied to BALB/c mice orally at a dose of 1 mg/g body weight for 5 days before I/R-injury was induced by clamping the vascular blood supply to the median and left lateral liver lobe for 1 h followed by a 6 h period of reperfusion. At this time, HPLC analysis revealed hepatic xanthohumol levels of approximately 2 μM, a concentration which has been shown to inhibit inflammatory effects in vitro. Assessment of hepatic HMOX1 expression, hepatic glutathione content and immunohistochemical analysis for proteins conjugated with the reactive aldehyde 4-hydroxynonenal indicated that I/R-induced oxidative stress was significantly inhibited in xanthohumol-fed compared to control mice. Histological analysis, TUNEL staining and determination of transaminase serum levels revealed no significant effects of xanthohumol on acute hepatocellular injury. However, at the same time point, pretreatment with xanthohumol almost completely blunted the I/R-induced AKT and NFκB activation and the expression of the proinflammatory genes IL-1alpha, IL-6, MCP-1 and ICAM-1, which are known to play a crucial role in the subacute phase of I/R-induced liver damage. In conclusion, these data indicate the potential of xanthohumol application to prevent adverse inflammatory responses to I/R-induced liver damage such as after surgical liver resection or transplantation.     

Comparison of cardioprotective and anti-inflammatory effects of ischemia pre- and postconditioning in rats with myocardial ischemia–reperfusion injury

Objective  

To compare cardioprotective and anti-inflammatory effects of ischemia preconditioning (IPC) and ischemia postconditioning (IPOC) in a rat myocardial ischemia–reperfusion injury (IRI) model.     

Emulsified isoflurane postconditioning produces cardioprotection against myocardial ischemia–reperfusion injury in rats

Emulsified isoflurane (EIso) preconditioning can induce cardioprotection. We investigated whether EIso application after ischemia protects hearts against reperfusion injury and whether it is mediated by the inhibition of apoptosis. Rats were subjected to 30-min coronary occlusion followed by 180-min reperfusion. At the onset of reperfusion, rats were intravenously administered saline (sham, control group), 30 % intralipid (IL group) or 2 ml kg^?1 EIso (EIso group) for 30 min. After reperfusion, infarct sizes, myocardial apoptosis and expression of Bcl-2, Bax and caspase-3 proteins were determined. Hemodynamic parameters were not different among groups. Compared with control and intralipid group, EIso limited infarct size, inhibited apoptosis, increased the expression of Bcl-2, decreased the expression of Bax, cleaved caspase-3, and enhanced Bcl-2/Bax ratio. EIso protects hearts against reperfusion injury when administered at the onset of reperfusion, which may be mediated by the inhibition of apoptosis via modulation of the expression of pro- and anti-apoptotic proteins.     

The effect of erythropoietin on endometrial edema during ischemia–reperfusion injury in rats

This experimental study examined the effect of erythropoietin (Epo) in a rat model and particularly in an ischemia–reperfusion protocol. The potential beneficial effect of Epo was studied pathologically using endometrial edema (EE) lesions. Endometrial edema was evaluated 60 min after reperfusion (Groups A and C) and 120 min after reperfusion (Groups B and D) in rats. Epo was administered only in Groups C and D. Epo administration non-significantly increased the EE scores by 0.05 (p = 0.9315). Reperfusion non-significantly increased the EE scores by 0.15 (p = 0.6508). Epo administration and reperfusion together non-significantly increased the EE scores by 0.027 (p = 0.8898). Epo administration, reperfusion, and their interaction reduced the EE scores from significant to non-significant levels. Perhaps a study time longer than 2 h or a higher Epo dose could result in complete resolution of the endometrial edema formed as a result of the ischemia–reperfusion injury in this rat model.     

Higenamine regulates Nrf2-HO-1-Hmgb1 axis and attenuates intestinal ischemia–reperfusion injury in mice

Inflammation Research - Intestinal ischemia and reperfusion (IR) syndrome is a life-threatening dilemma caused by diverse events. Higenamine (HG), an active ingredient of Aconiti Lateralis Radix...     

The interaction between ischemia–reperfusion and immune responses in the kidney

Kidney ischemia–reperfusion injury (IRI) engages both the innate and adaptive immune responses. Cellular mediators of immunity, such as dendritic cells, neutrophils, macrophages, natural killer T, T, and B cells, contribute to the pathogenesis of renal injury after IRI. Postischemic kidneys express increased levels of adhesion molecules on endothelial cells and toll-like receptors on tubular epithelial cells. Soluble components of the immune system, such as complement activation proteins and cytokines, also participate in injury/repair of postischemic kidneys. Experimental studies on the immune response in kidney IRI have resulted in better understanding of the mechanisms underlying IRI and led to the discovery of novel therapeutic and diagnostic targets.     

The opposite roles of nNOS in cardiac ischemia–reperfusion-induced injury and in ischemia preconditioning-induced cardioprotection in mice

The role of neuronal nitric oxide synthase (nNOS) in cardiac ischemia–reperfusion (IR) and ischemia preconditioning (IP) is still controversial. Here, we focused on the possible roles of nNOS in cardiac IR and IP. Wild type C57BL/6 (WT) mice were subjected to coronary artery occlusion for 30 min followed by 24-h reperfusion (IR). Cardiac injury (infarct size and apoptotic cell number) was increased, associated with elevation of oxidative stress (lipid peroxidation) and nitrative stress (nitrotyrosine formation). A potent nNOS inhibitor, L-VNIO, and a superoxide dismutase mimetic and peroxynitrite scavenger, MnTBAP, significantly reduced IR-induced increases of oxidative/nitrative stress and cardiac injury. IR-induced cardiac injury in nNOS^−/− (KO) mice was significantly lower than that in WT mice. MnTBAP markedly reduced IR-induced cardiac injury by suppression of oxidative/nitrative stress in KO mice. Cardiac IP was performed by three cycles of 5-min IR before 30-min ischemia followed by 24-h reperfusion. IP attenuated IR-induced cardiac injury in WT mice associated with reductions of oxidative/nitrative stress. IP-induced reduction of cardiac injury and oxidative/nitrative stress were eliminated by pretreatment with L-VNIO. In contrast with WT mice, IP had no protective effects in nNOS KO mice. In conclusion, nNOS played a dual role during cardiac IR and IP; nNOS exacerbated IR-induced injury by increasing oxidative/nitrative stress and contributed to IP-induced protection by inhibition of oxidative/nitrative stress.     

Quercetin ameliorates peripheral nerve ischemia–reperfusion injury through the NF-kappa B pathway

This study aimed to investigate the protective effect of quercetin against ischemia–reperfusion (IR) injury induced in the sciatic nerve of the rat. Quercetin (20 mg/kg) was given during ischemia just before reperfusion. Four groups of rats (Q+IR3, Q+IR7, Q+IR14, and Q+IR28) received 3, 7, 14, and 28 days of reperfusion, respectively, after the intraperitoneal injection of quercetin. After reperfusion, a behavioral test was performed and the sciatic functional index was calculated. Each sciatic nerve was stained to check for edema and ischemic fiber degeneration. Immunohistochemical staining was performed to detect TNF-alpha and NF-kappa B, and TUNEL staining was carried out to detect apoptosis. The Q+IR3, Q+IR7, and Q+IR14 groups showed significantly increased behavioral scores and ameliorated sciatic functional index values compared to IR-injured rats that received vehicle alone during ischemia and then the same period of reperfusion. The Q+IR3, Q+IR7, Q+IR14, and Q+IR28 groups presented significant ischemic fiber degeneration (IFD), TNF-alpha expression, and apoptosis as compared with the IR-injured and perfused rats that did not receive quercetin. The Q+IR3, Q+IR7, and Q+IR28 groups also exhibited significantly decreased NF-kappa B expression (p < 0.001, p = 0.001, p = 0.026) as compared with the IR-injured rats that were perfused but did not receive quercetin. These results imply that quercetin may be beneficial in the treatment of sciatic IR injury because of its antiapoptotic and antiinflammatory effects and its ability to decrease the expression of NF-kappa B.     

Expression and clinical significance of protein disulfide-isomerase a3 in a rabbit model of spinal cord ischemia/reperfusion injury北大核心

BACKGROUND: At present, spinal cord ischemia/reperfusion injury is considered as the main reason for “secondary paralysis” after spinal decompression, and to control the levels of stress-related proteins and excitatory amino acids plays an important role in the treatment of spinal cord ischemia/reperfusion injury. OBJECTIVE: To investigate the expression level of protein disulfide-isomerase A3 (PDIA3) after spinal cord ischemia/reperfusion injury in rabbits. METHODS: Thirty-six New Zealand white rabbits were enrolled, the models of spinal cord ischemia/reperfusion injury were established using Zivin’s method, and were then randomized into six groups (n=6 per group). The rabbit abdominal aorta in control group was exposed without vascular occlusion and then the abdominal cavity was closed 30 minutes later. In experimental groups, the abdominal aorta was blocked for 30 minutes, followed by 0, 6, 12, 24 and 48 hours of reperfusion, and then the abdominal cavity was closed. The neurological function was evaluated with a modified Tarlov score. The L3-5 lumbar vertebrae were removed, and PDIA3 was screened by two-dimensional fluorescence differential gel electrophoresis combined with mass spectrometry, and then its temporal and spatial changes in the spinal cord were detected by western blot assay and immunohistochemistry. RESULTS AND CONCLUSION: The function of hind limbs was improved in all the experimental groups after spinal cord ischemia/reperfusion injury, and the modified Tarlov scores reached the peak at 24 hours after schemia/reperfusion injury, and decreased slightly at 48 hours. The expression of PDIA3 in the control group showed clear imprinting, which was slightly strengthened at 0 hour, became more strengthened at 6-12 hours, significantly reduced to the minimum level at 24 hours, and returned to the level of 6-12 hours at 48 hours after ischemia/reperfusion. Immunohistochemical results showed that there was visible PDIA3 in the cytoplasm of neurons, and the expression level in the interneurons was significantly higher than that in the motor neurons. These results suggest that upregulated PDIA3 appears in the development and progression of spinal cord ischemia/reperfusion injury, indicating that PDIA3 is closely related to spinal cord ischemia/reperfusion injury, which can be used as a new diagnosis and treatment target. © 2017, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Nerve growth factor protects retinal ganglion cells against injury induced by retinal ischemia–reperfusion in rats

Abstract

In this study, we investigated the protective effect of mouse nerve growth factor (NGF) on retinal ganglion cell (RGC) injury induced by retinal ischemia–reperfusion (RIR) in rats and explored its possible mechanisms of action. RIR caused a significant injury to RGCs and an obvious impairment of the inner retina functions, which could be seen from flash electroretinogram and flash visual evoked potential recordings. RIR also increased the expression of the apoptotic protein Bax while decreasing the expression of Bcl-2 and the phosphorylation of protein kinase B (Akt) in RGCs. Preinjection (i.m.) of NGF for 22 d reversed the injury induced by RIR and ameliorated the inner retina functions. NGF also reduced the expression of Bax and reversed the reduction of Bcl-2 and the phosphorylated Akt induced by RIR. These results indicate that NGF produces a neuroprotective effect on RGCs against RIR injury and the protective effect of NGF is mainly mediated by the PI-3K/Akt signaling pathway.     

Protective effects of N-(2-mercaptopropionyl)-glycine against ischemia–reperfusion injury in hypertrophied hearts

The beneficial effects of N-(2-mercaptopropionyl)-glycine (MPG) against ischemia–reperfusion injury in normotensive animals have been previously studied. Our objective was to test the action of MPG during ischemia and reperfusion in hearts from spontaneously hypertensive rats (SHR). Isolated hearts from SHR and age-matched normotensive rats Wistar Kyoto (WKY) were subjected to 50-min global ischemia (GI) and 2-hour reperfusion (R). In other hearts MPG 2 mM was administered during 10 min before GI and the first 10 min of R. Infarct size (IS) was assessed by TTC staining technique and expressed as percentage of risk area. Postischemic recovery of myocardial function was assessed. Reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and SOD cytosolic activity — as estimators of oxidative stress and MnSOD cytosolic activity — as an index of (mPTP) opening were determined. In isolated mitochondria H₂O₂-induced mPTP opening was also measured. The treatment with MPG decreased infarct size, preserved GSH levels and decreased SOD and MnSOD cytosolic activities, TBARS concentration, and H₂O₂ induced-mPTP opening in both rat strains. Our results show that in both hypertrophied and normal hearts an attenuation of mPTP opening via reduction of oxidative stress appears to be the predominant mechanism involved in the cardioprotection against reperfusion injury MPG-mediated.     

Hyperbaric oxygen preconditioning reduces ischemia–reperfusion injury by inhibition of apoptosis via mitochondrial pathway in rat brain

This study examined the hypothesis that apoptotic inhibition via mitochondrial pathway was involved in hyperbaric oxygen preconditioning (HBO-PC)–induced neuroprotection on ischemia–reperfusion injury in rat brain. Male Sprague–Dawley rats (250∼280 g, n=144) were divided into control, middle cerebral artery occlusion (MCAO) for 90 min, and HBO-PC plus MCAO groups. HBO-PC was conducted four times by giving 100% oxygen at 2.5 atm absolute (ATA), for 1 h at 12 h intervals for 2 days. At 24 h after the last HBO-PC, MCAO was performed and at 24 h after MCAO, neurological function, brain water content, infarct volume, and cell death were evaluated. Enzymatic activity of capase-3 and −9, and expression of cytochrome c, Bcl-2 and Bax proteins were performed in the samples from hippocampus, ischemic penumbra and core of the brain cortex, respectively. HBO-PC reduced brain edema, decreased infarction volume, and improved neurological recovery. HBO-PC reduced cytoplasm cytochrome c levels, decreased caspase enzyme activity, upregulated the ratio of Bcl-2 and Bax expression, and abated the apoptosis of ischemic tissue. HBO-PC protects brain tissues from ischemia–reperfusion injury by suppressing mitochondrial apoptotic pathways.     

Anandamide enhances expression of heat shock protein 72 to protect against ischemia–reperfusion injury in rat heart

Anandamide (AEA), one of endocannabinoids, has been reported to exhibit a cardioprotective ability to limit the damage produced by ischemia–reperfusion injury. AEA reportedly enhanced heat shock protein 72 (HSP72) and HSP25 expression in lungs to protect against lung inflammation. This study tested the hypothesis that intravenously injected AEA would induce HSP72 in the heart and thus render cardioprotection against ischemia–reperfusion injury in rats. Cardiac expression of HSPs was quantitatively evaluated in rats by Western blot analysis. That intravenously injected AEA 1 mg/kg in vivo induced expression of HSP72, which peaked at 24 h after administration. The enhancement of HSP72 by AEA was blocked by cannabinoid 2 (CB₂) receptor antagonist AM630, but not cannabinoid 1 (CB₁) receptor antagonist AM251. Therefore, the rats were induced with a 30-min coronary occlusion followed by a 120-min reperfusion in vivo at 24 h after administration of drugs or vehicle, and then the infarct size was measured. AEA reduced myocardial infarct size compared to control group. Pretreatment with AM630 but not AM251 abolished the infarct size-limiting effect of AEA. Further study demonstrated pretreatment with phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin, Akt inhibitor MK-2206 and AM630 attenuated phosphorylation of Akt and AEA-induced HSP72 expression. The results suggest that AEA is cardioprotective against ischemia–reperfusion insult through its induction of HSP72, which might be mediated by the PI3K/Akt signaling pathway. These effects were mediated by CB₂ but not CB₁ receptors.     

Locally synthesized HSP27 in hepatocytes: Is it possibly a novel strategy against human liver ischemia/reperfusion injury?

Ischemia/reperfusion injury (IRI) is a common complication after liver surgery. Approximately 10% of grafts lose function in the early stage after liver transplantation. However, there is no effective way against IRI yet. Heat shock protein 27 (HSP27), a member of the heat shock protein families, is recognized as a protective factor against liver IRI recently. Studies showed that HSP27 can lessen the induction of proinflammatory messenger, reduce neutrophil infiltration, decrease apoptosis (caspase 3 fragmentation and DNA laddering), and reduce disruption of filamentous actin. In addition, Kupffer cells inhibitor- gadolinium chloride can reduce lipid peroxidation and promote hepatocytes regeneration. Herein, we hypothesize that transfecting liver with HSP27 gene accompanied by gadolinium chloride might be a potentially novel treatment against IRI. Compared to passive defense, we firstly suggest positive protection against ischemia/reperfusion injury by hepatocytes automatically.     

Hydrogen rich water protects against myocardial ischemia/reperfusion injury in rats北大核心

BACKGROUND: Increasing evidence has indicated that low-concentration hydrogen or hydrogen rich water or hydrogen saturated saline exerts a protective effect on various diseases, such as myocardial ischemia/reperfusion injury. OBJECTIVE: To explore the protective effect of hydrogen rich water on myocardial ischemia/reperfusion injury. METHODS: Forty-eight Wistar rats were equally randomized into control and hydrogen-rich groups, and then subdivided into ischemic preconditioning, ischemia, and ischemia/reperfusion groups (n=8 rats in each subgroup). The myocardial ischemia/reperfusion model was established in the heart of each rat by the following procedures: reverse perfusion for 10 minutes, room temperature for 20 minutes, and reperfusion for 20 minutes. The control rats was perfused with pre-oxygenated (95% O2 plus 5% CO2) 37 ℃ K-R solution and the hydrogen-rich group was perfused with pre-oxygen-equilibrated (95% O2 plus 5% CO2) 37 ℃ K-R solution plus hydrogen-rich water (0.6 mmol/L, pH=7.3). Subsequently, the heart was removed, the pathological changes of the myocardial tissues were observe by hematoxylin-eosin staining, the activities of lactic dehydrogenase and creatine kinase in the myocardial tissues were determined, and the levels of tumor necrosis factor-α and interleukin-1β were detected by ELISA. RESULTS AND CONCLUSION: In the control group, the activity of lactic dehydrogenase at the ischemic and ischemia/reperfusion stages was significantly higher than that at the ischemic preconditioning stage (P < 0.05), and the activity of creatine kinase at the ischemia/reperfusion stage was significantly higher than that at the ischemic preconditioning and ischemic stages (P < 0.05). In the hydrogen-rich group, there was no significant difference in the activities of lactic dehydrodenase and creatine kinase at each stage, but the activities of at the ischemia/reperfusion stage was significantly lower than those in the control group (P < 0.05). In the two groups, the order of the levels of tumor necrosis factor-α and interleukin-1β was as follows: the ischemia/reperfusion stage > ischemic stage > ischemic preconditioning stage (P < 0.05). The levels of above factors in the hydrogen-rich group were significantly lower than those in the control group (P < 0.05). Our findings imply that hydrogen rich water has protective effect on myocardial ischemia/reperfusion injury of the rat hearts in vitro, which may be by reducing the expression of tumor necrosis factor-α and interleukin-1β, and further alleviating the inflammatory response. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.