Ischemia-reperfusion Group Group Research Articles

Beta Glukanin Deneysel Böbrek İskemi Reperfüzyon Hasarina Karşi Koruyucu Etkileri

Aim: This study aims to investigate the possible protective effects of beta-glucan against oxidative stress caused by ischemia and reperfusion injury in kidney tissue.Methods: In the study, 30 male Wistar albino rats weighing 300-350g were used (n=10). Rats were randomly grouped into three groups of Sham control, ischemia reperfusion group (IR), ischemia reperfusion + beta glucan group (IR + BG). Sham group had left nephrectomy, the right kidney taken for histopathologic and biochemical examination. After left nephrectomy in IR group, ischemia procedure was applied for 45 minutes via nontraumatic microvascular clamp, then reperfusion was applied for 60 minutes in the right kidney. In the IR+BG group, rats were administered 100 mg/kg beta glucan via gastric gavage for 10 days. Reperfusion was applied for 60 minutes after 45 minutes of ischemia to the right kidney under anesthesia.Results: As a result of biochemical examination MDA values showed a significant increase in IR group compared to Sham group (p<0,05). In IR+BG group, there was a significant decrease compared to IR group (p<0,05). Tissue MPO values in IR group showed a significant increase compared to Sham group, whereas in the IR+BG group there was not a significant decrease. Also, there was not a significant difference in tissue catalase levels. Tissue GSH values showed a significant decrease in IR group compared to Sham group (p<0,05). In the IR+BG group a significant increase was found compared to IR group (p<0,05). Less damage has been revealed in the IR+BG group compared to IR group in histopathologic examination.Conclusion: All these data show that beta glucan may have an antioxidant effect on renal ischemia reperfusion injury.

Protective Effect of Hydrogen Gas on Mouse Hind Limb Ischemia-Reperfusion Injury

The aim of this study was to investigate the mechanism of hydrogen gas on hind limb IR injury. Male C57BL/6 mice were randomly divided into three groups: sham group (Sham), ischemia-reperfusion group (IR), IR plus H2 inhalation group (IR+H2). IR was induced by interrupting hind limb blood flow for 3h, followed by 4h of reperfusion, and H2 was administered by inhalation throughout the reperfusion process. Our data show that H2 inhalation could significantly decrease the infarct-affected tissue volume (P < 0.05), attenuate the degree of morphological injury (P < 0.05), and suppress the level of oxidative stress damage (P < 0.05), compared with the IR group. In exploring the underlying mechanisms, we found that hydrogen could markedly mitigate the degree of IR-induced ER stress and apoptosis (P < 0.05). Additionally, hydrogen could markedly inhibit the IR injury by modulating the phosphorylated c-Jun N-terminal kinase (JNK) signaling pathway (P < 0.05). Taken together, these results revealed the protective effect of hydrogen gas on hind limb ischemia reperfusion injury on mice by attenuating oxidative stress, impairing ER stress and apoptosis, and its ability to modulate JNK signaling pathway.

The long non-coding RNA MALAT1 is increased in renal ischemia-reperfusion injury and inhibits hypoxia-induced inflammation

Background: To investigate the expression of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in renal ischemia-reperfusion injury and explore its role in acute kidney injury.Methods: 18 mice were randomly divided into a sham operation group (Sham) and an ischemia-reperfusion group (IR) in which animals were sacrificed at 6 h or 12 h after surgery. The kidneys were harvested to measure the expression of MALAT1 mRNA. HK2 cells were treated with cobalt chloride (CoCl2) to mimic hypoxia or transfected with siRNA to knockdown MALAT1 before CoCl2 treatment. After that, MALAT1 was analyzed by RT-PCR (reverse transcription-polymerase chain reaction). HIF-1ɑ (hypoxia-inducible factor-1 alpha) and NF-κB (nuclear factor-kappa B) was measured by Western blot. The concentrations of IL-6 (interleukin-6) and TNF-ɑ (tumor necrosis factor-alpha) in the media were detected by ELISA (enzyme-linked immunosorbent assay).Results: The expression of MALAT1 in the IR (6 h/12 h) group was significantly higher than that in the sham group. In HK2 cells, MALAT1 was significantly increased at 1 h, 3 h, and 6 h after CoCl2 treatment but had reduced to the basal level at 12 h and 24 h. Knockdown of MALAT1 by siRNA significantly up-regulated the expression of HIF-1ɑ and NF-κB proteins in CoCl2-treated HK2 cells. In addition, the concentrations of IL-6 and TNF-ɑ were increased by MALAT1 siRNA transfection in CoCl2-treated HK2 cells.Conclusion: The expression of MALAT1 is increased in renal ischemia-reperfusion injury. It is likely that MALAT1 inhibits the hypoxia-induced inflammatory response through the NF-κB pathway.

The effect of hyperbaric oxygen preconditioning on the expression of ICAM-1, VCAM-1, NF-κB and flap survival rate during ischemia-reperfusion injury in rat abdominal skin flap

To evaluate the effect of hyperbaric oxygen preconditioning on the expression of intercellular adhesion molecule-1 (ICAM-1),vascular cell adhesion molecule-1 (VCAM-1),NF-κB and flap survival rate during Ischemia-Reperfusion Injury in Rat Abdominal Skin Flap. 18 male adult SD rats were divided randomly into sham group (SH),ischemia-reperfusion group (IR) and hyperbaric oxygen preconditioning group (HBO),6 rats in each group. The rats in HBO group received regular hyperbaric oxygen treatment for three days (twice a day with an interval of 12 h) before operation. An abdominal skin flap pedicled with superficial epigastric artery was established. Ischemia lasted for 3 hours in the IR group and HBO group.On the third postoperative day,samples were taken to evaluate the expression of ICAM-1,VCAM-1 and NF-κB by immunohistochemistry staining and Western Blot. In the IR group, the flap survival rate and average blood perfusion were (22.38 ±4.35) ％ and (32.61 ±5.68) PU, while in the HBO group they were (45.34 ±3.15) ％ and (61.78 ±3.61) PU, showing significant difference between the two groups (P ＜0.01).The inflammatory cell infiltration condition in IR group was much higher than that in the HBO group from the HE staining observation. Compared with the HBO group,ICAM-1,VCAM-1 and NF-κB showed (+ + +) with higher positive cells in the IR group (P ＜ 0.01). Results of Western Blot showed similar conclusion. The relative expression of ICAM-1,VCAM-1 and NF-κB was much higher in the IR group than that in the HBO group (P ＜ 0.01). Hyperbaric oxygen preconditioning could decrease the expression of ICAM-1,VCAM-1,NF-κB and promote flap survival rate during the process of ischemia-reperfusion injury on a rat abdominal skin flap model.

Protective Effect of Ischemic Preconditioning on Hepatic Ischemia-Reperfusion Injury in Rats

Aim: Ischemic preconditioning (IPC) protects tissue against ischemia and reperfusion (I/R) injury. The aim of this study was to examine the impact of IPC on protection of hepatocytes after prolonged I/R injury. Methods: Twenty-four Wistar rats were randomly divided into ischemic preconditioning group (IP), ischemia/reperfusion group (IR) and sham operation group (SO). A model of partial liver ischemia/reperfusion was used, in which rats were subjected to liver ischemia for 90 min prior to reperfusion. The animals in the IP group underwent ischemic preconditioning for 10 min prior to the ischemia/reperfusion challenge. After 3 h of reperfusion, serum and liver tissue in each group were collected to detect the level of serum ALT, AST, HA, MDA and liver histopathology. Results: Compared with IR group, IP group showed a significantly lower ALT, AST, HA and MDA level in 3 h. Proliferation index (PI) was significantly increased in IP group compared with IR group. Conclusion: Ischemic preconditioning can protect liver cells against ischemia/reperfusion injury, which may be related to cell proliferation during early ischemic reperfusion.

Expression of oxidative stress and antioxidant defense genes in the kidney of inbred mice after intestinal ischemia and reperfusion

To determine the gene expressions profile related to the oxidative stress and the antioxidant response in the kidneys of mice subjected to intestinal ischemia and reperfusion. Twelve inbred mice (C57BL/6) were randomly assigned to one of two groups: the control group (CG) underwent anesthesia and was observed for 120 min and the ischemia/reperfusion group (IRG), animals were anesthetized and subjected to laparotomy and ischemia for 60 minutes followed by 60 minutes of reperfusion. The expressions of 84 genes from the kidney were determined by the Reverse Transcription qualitative Polymerase Chain Reaction (RT-qPCR). All genes that were up regulated by more than threefold using the algorithm [2(ΔΔCt)] were considered statically significant (p<0.05). In the IRG group 29 (34.52%) of 84 genes, were up regulated by more than threefold. The genes that were differentially up regulated in the glutathione peroxidase cluster (10 genes): were Gpx2 and Gpx7. The genes that were up regulated in the peroxidase cluster (16 genes) were following: Duox1, Epx, Lpo, Mpo, Ptgs2, Rag2, Serpinb1b, Tmod1 and Tpo. The genes that up regulated in the reactive oxygen species cluster (16 genes): Il19, Il22, Nos2, Nox1, Noxa1, Noxo1, Recql4 and Sod2. The genes that were up regulated in the oxidative stress cluster (22 genes) were: Mpp4, Nudt15, Upc3 and Xpa. The genes that were up regulated in the oxygen carriers cluster (12 genes) were: Hbq1, Mb, Ngb, Slc38a1 and Xirp1. The peroxiredoxins genes (10) showed no consistent differential regulation. The genes related to oxidative stress and antioxidant defense showed increased expression in renal tissue trigged intestinal ischemia and reperfusion.

The role of calreticulin in three different kinds of preconditioning against myocardial ischemia/reperfusion injury in rats

Objective To evaluate the role of calreticulin (CRT) in myocardial protection of three different kinds of preconditioning against myocardial ischemia/reperfusion injury. Methods Thirty SD rats were randomly divided into 5 groups:ischemia reperfusion group (IR), ischemia preconditioning group(IP), adenosine preconditioning group (AP), remote preconditioning group(RP), and sham-opera-tion group (blank control). The ischemia/reperfusion model was established in vivo. Hemodynamic chan-ges of heart function were observed,and serum cardiac Troponin T (cTnT), superoxide dismutase (SOD), malondialdehyde (MDA) and the expression of CRT in myocardium were detected. Results ±dp/dt max,serum cTnT and MDA,and the expression of CRT in RP, AP and IP groups were significantly lower than those in IR group, also SOD level in these three groups was higher than in IR group (P<0.05). AP group had a higher SOD level venous IP and RP groups (P<0.05),also cTnT in AP group was lower than in IP and RP groups (P<0.05). Conclusion Remote preconditioning may mimic the protective effect of ischemic preconditioning. Remote preconditioning attenuated myocardial ischemia/reperfusion injury in vi-vo possibly through down-regulating the CRT expression in rats. Key words: Cadiocyte; Ischemic preconditoning; Adenosine; Reperfusion injury; Calret-iculin

Protective roles of heat stress on the neurons in hippocampal CA1 region of mice

The effects of heat stress on the neurons in hippocampal CA1 region of brain ischemia/reperfusion were explored. The mice were pretreated with heat stress followed by ischemia/reperfusion by clipping bilateral cervical common arteries for 7 min. Mice were divided randomly into four groups as follows: (1) normal control group; (2) heat stress pretreated subsequent to ischemia/reperfusion group (HS/IR); (3) ischemia/reperfusion group (IR); and (4) heat stress group (HS). Animals in the last three groups were subdivided into three subgroups: 1 d, 4 d, 14 d respectively. The Morris water maze was used to test the ability of learning and memorizing, Nissl staining was used to count the average number of survived neurons in hippocampal CA1 region, and immunohistochemistry combined with image analysis system to detect the changes of Microtubule associated protein 2 (MAP-2) expression. The results showed that mice in IR group exhibited increased escape latency when compared with that of normal, HS and HS/IR groups (P < 0.01), and the mice in IR group adopted an inefficient search strategy, major in circling and restricted searching manners. Nissl staining results showed a significant reduction in the number of pyramidal neurons in hippocampal CA1 regions in HS/IR and IR groups, with a decrease in IR group (P < 0.01). Compared with normal group, the expression of MAP-2 in hippocampal CA1 region obviously decreased in IR group (P < 0.05). The present results indicate that heat stress pretreatment can improve the spatial learning and memorizing function through protection to hippocampal neurons.

Effects of ischemic preconditioning on cyclinD1expression during early ischemic reperfusion in rats

To observe the effect of ischemic preconditioning on cyclinD1 expression in rat liver cells during early ischemic reperfusion. Fifty-four SD rats were randomly divided into ischemic preconditioning group (IP), ischemia/reperfusion group (IR) and sham operation group (SO). The IP and IR groups were further divided into four sub-groups (n = 6). Sham operation group (SO) served as the control group (n = 6). A model of partial liver ischemia/reperfusion was used, in which rats were subjected to liver ischemia for 60 min prior to reperfusion. The animals in the IP group underwent ischemic preconditioning twice for 5 min each time prior to the ischemia/reperfusion challenge. After 0, 1, 2, and 4 h of reperfusion, serum and liver tissue in each group were collected to detect the level of serum ALT, liver histopathology and expression of cyclinD1 mRNA and protein. Flow cytometry was used to detect cell cycle as the quantity indicator of cell regeneration. Compared with IR group, IP group showed a significantly lower ALT level in 1 h to 4 h sub-groups (P < 0.05). Proliferation index (PI) indicated by the S-phase and G2/M-phase ratio [(S+G2/M)/(G0/G1+S+G2/M)] was significantly increased in IP group at 0 and 1 h (26.44 +/- 7.60% vs 18.56 +/- 6.40%, 41.87 +/- 7.27% vs 20.25 +/- 6.70%, P < 0.05). Meanwhile, cyclinD1 protein expression could be detected in IP group. But in IR group, cyclinD1 protein expression occurred 2 h after reperfusion. The expression of cyclinD1 mRNA increased significantly in IP group at 0 and 1 h (0.568 +/- 0.112 vs 0.274 +/- 0.069, 0.762 +/- 0.164 vs 0.348 +/- 0.093, P < 0.05). Ischemic preconditioning can protect liver cells against ischemia/reperfusion injury, which may be related to cell proliferation and expression of cyclinD1 during early ischemic reperfusion.

The delayed protection of exercise preconditioning from the relative myocardial ischemia-reperfusion injury.

To explore the delayed protection of exercise preconditioning from the relative myocardial ischemia-reperfusion injury. The experiment included the vivo experiment and the vitro experiment, 32 Wistar rats in each experiment were divided into 4 groups randomly: control group (CN), relative ischemia reperfusion group (IR), exercise preconditioning group (EP) and Exercise preconditioning + relative ischemia-reperfusion group (EI). We detected the third loading exercise time, the levels of MDA in serum in vivo experiment and the Cardiac function parameter, the levels of MDA in coronary effluent in vitro experiment. (1) The vivo experiment: The third loading exercise time of EI group [(71.67 +/- 9.00) min] increased significantly compared with that of IR group [(58.67 +/- 4.13) min] (P < 0.05); The levels of MDA in serum of EP group (107.00 +/- 35.99) micromol/L and EI group [(152.23 +/- 29.94) micromol/L] decreased significantly contrasted to IR group (313.20 +/- 43.40 micromol/L) (P < 0.05). (2) The vitro experiment: The PRP (heart rate * left ventricular developed pressure) in reperfusion period of CN group and EP group were stable relatively, while it reached the peak after 30 minutes and almost recovered to the level before ischemia in EI group. The parameter of IR group recovered slightly but was lower significantly than that before ischemia. There was significant difference between the recovery rate of Cardiac function of EI group and that of IR group. The increase of MDA in coronary effluent after Ischemia-reperfusion of EP group (0.34 +/- 0.24 micromol/L) and EI group [(0.41 +/- 0.26) micromol/L] decreased significantly contrasted to that of IR group [(1.27 +/- 0.52) micromol/L] (P < 0.05). EP has the obvious delayed protection from the relative myocardial ischemia-reperfusion injury.

Role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning.

To investigate the role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning (IPC). A rat model of acute hepatic ischemia-reperfusion was established, 24 healthy male Wistar rats were randomly divided into sham-operated group, ischemia-reperfusion group (IR) and IPC group. IPC was achieved by several brief pre-reperfusions followed by a persistent reperfusion. Concentration of malondialdehyde (MDA) and activity of several antioxidant enzymes in hepatic tissue were measured respectively. Apoptotic cells were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and expression of Bcl-2 protein was measured by immunohistochemical techniques. Moreover, mitochondrial ultrastructure and parameters of morphology of the above groups were observed by electron microscope. Compared with IR group, the concentration of MDA and the hepatocellular apoptotic index in IPC group was significantly reduced (P<0.05), while the activity of antioxidant enzymes and OD value of Bcl-2 protein were markedly enhanced (P<0.05). Moreover, the injury of mitochondrial ultrastructure in IPC group was also obviously relieved. IPC can depress the synthesis of oxygen free radicals to protect the mitochondrial ultrastructure and increase the expression of Bcl-2 protein that lies across the mitochondrial membrane. Consequently, IPC can reduce hepatocellular apoptosis after reperfusion and has a protective effect on hepatic ischemia-reperfusion injury.