This study aims to investigate the mechanism of acacetin in protecting rats from cerebral ischemia-reperfusion injury via the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. Wistar rats were randomized into sham, model, low-and high-dose acacetin, and nimodipine groups, with 10 rats in each group. The rat model of middle cerebral artery occlusion(MCAO) was established with the improved suture method in other groups except the sham group. The neurological deficit score and cerebral infarction volume of each group were evaluated 24 h after modeling. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1β(IL-1β), IL-6, tumor necrosis factor-α(TNF-α), malondialdehyde(MDA), supe-roxide dismutase(SOD), and glutathione(GSH). Western blot was employed to determine the expression levels of B-cell lymphonoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and TLR4/NLRP3 signaling pathway-related proteins(TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β) in the rat brain tissue. Hematoxylin-eosin(HE) staining was employed to reveal the histopathological changes in the ischemic area. Compared with the sham group, the modeling of MCAO increased the neurological deficit score and cerebral infarction volume, elevated the IL-1β, IL-6, TNF-α, and MDA levels and lowered the SOD and GSH levels in the brain tissue(P<0.05). Compared with the MCAO model group, low-and high-dose acacetin and nimodipine decreased the neurological deficit score and cerebral infarction volume, lowered the IL-1β, IL-6, TNF-α, and MDA levels and elevated the SOD and GSH levels in the brain tissue(P<0.05). Compared with the sham group, the model group showed up-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and down-regulated protein level of Bcl-2 in the brain tissue(P<0.05). Compared with the MCAO model group, the acacetin and nimodipine groups showed down-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and up-regulated protein level of Bcl-2 in the brain tissue(P<0.05). In conclusion, acacetin regulates the TLR4/NLRP3 signaling pathway to inhibit neuroinflammatory response and oxidative stress, thus exerting the protective effect on cerebral ischemia-reperfusion injury in rats.
Rats ; Animals ; NF-kappa B/metabolism* ; bcl-2-Associated X Protein ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Sprague-Dawley ; Caspase 1/metabolism* ; Toll-Like Receptor 4/metabolism* ; Nimodipine/pharmacology* ; Interleukin-6 ; Rats, Wistar ; Signal Transduction ; Infarction, Middle Cerebral Artery ; Reperfusion Injury/prevention & control* ; Superoxide Dismutase/metabolism*

Cerebral ischemia-reperfusion injury(CIRI) is an important factor hindering the recovery of ischemic stroke patients after blood flow recanalization. Mitochondria, serving as the "energy chamber" of cells, have multiple important physiological functions, such as supplying energy, metabolizing reactive oxygen species, storing calcium, and mediating programmed cell death. During CIRI, oxidative stress, calcium overload, inflammatory response, and other factors can easily lead to neuronal mitochondrial dyshomeostasis, which is the key pathological link leading to secondary injury. As reported, the mitochondrial quality control(MQC) system, mainly including mitochondrial biosynthesis, kinetics, autophagy, and derived vesicles, is an important endogenous mechanism to maintain mitochondrial homeostasis and plays an important protective role in the damage of mitochondrial structure and function caused by CIRI. This paper reviewed the mechanism of MQC and the research progress on MQC-targeting therapy of CIRI in recent 10 years to provide theoretical references for exploring new strategies for the prevention and treatment of ischemic stroke with traditional Chinese medicine.
Brain Ischemia/prevention & control* ; Calcium/metabolism* ; Humans ; Ischemic Stroke ; Mitochondria/pathology* ; Reactive Oxygen Species/metabolism* ; Reperfusion Injury/prevention & control*

Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia Miltiorrhiza Bge, a traditional Chinese medicine, which has been used for the treatment of cerebrovascular diseases for centuries. The present study aimed to determine the brain protective effects of SAA against cerebral ischemia reperfusion injury in rats, and to figure out whether SAA could protect the blood brain barrier (BBB) through matrix metallopeptidase 9 (MMP-9) inhibition. A focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion (MCAO) for 1.5-h followed by 24-h reperfusion. SAA was administered intravenously at doses of 5, 10, and 20 mg·kg. SAA significantly reduced the infarct volumes and neurological deficit scores. Immunohistochemical analyses showed that SAA treatments could also improve the morphology of neurons in hippocampus CA1 and CA3 regions and increase the number of neurons. Western blotting analyses showed that SAA downregulated the levels of MMP-9 and upregulated the levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) to attenuate BBB injury. SAA treatment significantly prevented MMP-9-induced degradation of ZO-1, claudin-5 and occludin proteins. SAA also prevented cerebral NF-κB p65 activation and reduced inflammation response. Our results suggested that SAA could be a promising agent to attenuate cerebral ischemia reperfusion injury through MMP-9 inhibition and anti-inflammation activities.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; Blood-Brain Barrier ; drug effects ; enzymology ; immunology ; Brain ; Brain Ischemia ; drug therapy ; enzymology ; genetics ; Caffeic Acids ; administration & dosage ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Lactates ; administration & dosage ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; enzymology ; genetics ; immunology ; prevention & control ; Salvia miltiorrhiza ; chemistry ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Transcription Factor RelA ; genetics ; immunology

To explore the effect of epigallocatechin gallate (EGCG) on oxidative stress and Nrf2/HO-1 pathway in neurons subjected to oxygen-glucose deprivation/reperfusion (OGD/R).
 Methods: Primary cultured cerebral cortical neurons were prepared from Sprague-Dawley rats, and the OGD/R cell model was established. After pretreatment with EGCG at different concentrations (12.5, 25.0, 50.0 or 100.0 μmol/L), the neurons were subjected to OGD/R. The cell viability, reactive oxygen species (ROS) level and malondialdehyde (MDA) content were assessed after reperfusion. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured. The expression of Nrf2 protein in nucleus, HO-1 mRNA and protein were detected.
 Results: OGD/R treatment reduced the cell viability, elevated ROS level and MDA content, decreased SOD and GSH-Px activities. The expression of Nrf2 protein in nucleus, HO-1 mRNA and protein were increased (P<0.01). Pretreatment with EGCG promoted the survival of neurons exposed to OGD/R, decreased ROS level and MDA content while increased SOD and GSH-Px activities. The levels of Nrf2 protein in nucleus, HO-1 mRNA and protein were upregulated (P<0.01).
 Conclusion: EGCG can reduce the oxidative stress of neurons subjected to OGD/R, which may be related to activation of Nrf2/HO-1 signal pathway and enhancement of the antioxidant ability of neurons.
Animals ; Catechin ; analogs & derivatives ; pharmacology ; Cell Survival ; drug effects ; Cells, Cultured ; Gene Expression Regulation ; drug effects ; Glucose ; Heme Oxygenase-1 ; genetics ; metabolism ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Neurons ; drug effects ; Neuroprotective Agents ; pharmacology ; Oxidative Stress ; drug effects ; Oxygen ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control

To explore the protective effect of rosiglitazone (RGZ) on hepatic ischemia reperfusion injury (HIRI) and the underlying mechanisms.
 Methods: A rat model of ischemia-reperfusion injury was established by clamping the left and middle lobe of liver with noninvasive vascular clamp. A total of 30 Sprague-Dawley rats were randomly divided into a sham group, an HIRI group, and a RGZ group (10 rats in each group). Two hours after reperfusion, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, lactate dehydrogenase (LDH) level, malondialdehyde (MDA) content and catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were examined. HE staining was used to observe liver pathological morphology. The liver peroxisome proliferators-activated receptor γ (PPAR-γ), p-PPAR-γ, nuclear factor related factor 2 (Nrf-2), antioxidant response element (ARE), heme oxygenase 1 (HO-1) and quinone oxidoreductase-1 (NQO-1) were detected by Western blot.
 Results: Compared with the HIRI group, the levels of ALT, AST, LDH and MDA in the RGZ group were significantly decreased (all P<0.05), while the levels of Nrf-2, ARE, HO-1 and NQO-1 in the RGZ group were significantly increased. The hepatic swelling, necrosis and pathological damage were decreased (all P<0.05). In addition, there was no difference in the level of PPAR-γ between the 2 groups (P>0.05).
 Conclusion: PPAR-γ agonist RGZ can attenuate HIRI, which may be related to activating Nrf2/ARE signaling pathway and enhancement of antioxidant ability.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Catalase ; blood ; Disease Models, Animal ; Glutathione Peroxidase ; blood ; L-Lactate Dehydrogenase ; blood ; Ligation ; Liver ; blood supply ; metabolism ; Malondialdehyde ; blood ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; blood ; etiology ; prevention & control ; Rosiglitazone ; Superoxide Dismutase ; blood ; Thiazolidinediones ; therapeutic use

BACKGROUNDIt is well documented that sevoflurane postconditioning (SP) has a significant myocardial protection effect. However, the mechanisms underlying SP are still unclear. In the present study, we investigated the hypothesis that the Pim-1 kinase played a key role in SP-induced cardioprotection by regulating dynamics-related protein 1 (Drp1).

METHODSA Langendorff model was used in this study. Seventy-two rats were randomly assigned into six groups as follows: CON group, ischemia reperfusion (I/R) group, SP group , SP+proto-oncogene serine/threonine-protein kinase 1 (Pim-1) inhibitor II group, SP+dimethylsufoxide group, and Pim-1 inhibitor II group (n = 12, each). Hemodynamic parameters and infarct size were measured to reflect the extent of myocardial I/R injury. The expressions of Pim-1, B-cell leukemia/lymphoma 2 (Bcl-2) and cytochrome C (Cyt C) in cytoplasm and mitochondria, the Drp1 in mitochondria, and the total Drp1 and p-Drp1ser637 were measured by Western blotting. In addition, transmission electron microscope was used to observe mitochondrial morphology. The experiment began in October 2014 and continued until July 2016.

RESULTSSP improved myocardial I/R injury-induced hemodynamic parametric changes, cardiac function, and preserved mitochondrial phenotype and decreased myocardial infarct size (24.49 ± 1.72% in Sev group compared with 41.98 ± 4.37% in I/R group; P< 0.05). However, Pim-1 inhibitor II significantly (P < 0.05) abolished the protective effect of SP. Western blotting analysis demonstrated that, compared with I/R group, the expression of Pim-1 and Bcl-2 in cytoplasm and mitochondria as well as the total p-Drp1ser637 in Sev group (P < 0.05) were upregulated. Meanwhile, SP inhibited Drp1 compartmentalization to the mitochondria followed by a reduction in the release of Cyt C. Pretreatment with Pim-1 inhibitor II significantly (P < 0.05) abolished SP-induced Pim-1/p-Drp1ser637 signaling activation.

CONCLUSIONSThese findings suggested that SP could attenuate myocardial ischemia-reperfusion injury by increasing the expression of the Pim-1 kinase. Upregulation of Pim-1 might phosphorylate Drp1 and prevent extensive mitochondrial fission through Drp1 cytosolic sequestration.

Animals ; Dynamins ; metabolism ; Hemodynamics ; drug effects ; Ischemic Postconditioning ; methods ; Male ; Methyl Ethers ; therapeutic use ; Mitochondria ; drug effects ; metabolism ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Proto-Oncogene Proteins c-pim-1 ; antagonists & inhibitors ; metabolism ; Quinazolinones ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the effect of limb remote ischemic preconditioning (RIPC) on hepatic ischemia/reperfusion (IR) injury and the underlying mechanisms.
 METHODS: Rats were subjected to partial hepatic IR (60 min ischemia followed by 24 hours reperfusion) with or without RIPC, which was achieved by 3 cycles of 10 min-occlusion and 10 min-
reperfusion at the bilateral femoral arteries interval 30 min before ischemia. Some rats were treated with a new PPAR-γ inhibitor, T0070907, before RIPC.
 RESULTS: At the end of reperfusion, liver injury was significantly increased (increases in Suzike's injury score, AST and ALT release), concomitant with elevated oxidative stress (increases in MDA formation, MPO activity, as well as the decrease in SOD activity) and inflammation (increases in TNF-α and IL-6 levels, decrease in IL-10 content). RIPC improved liver function and reduced histologic damage, accompanied by the increased PPAR-γ activation and autophagosome formation as well as the reduced autophagosome clearance. The beneficial effects of RIPC were markedly attenuated by T0070907, an inhibitor of PPAR-γ.
 CONCLUSION RIPC exerts the protective effects on liver by activation of autophagy via PPAR-γ.
Animals ; Autophagy ; drug effects ; genetics ; physiology ; Extremities ; Interleukin-10 ; metabolism ; Interleukin-6 ; metabolism ; Ischemia ; Ischemic Preconditioning ; methods ; Liver ; injuries ; Liver Diseases ; prevention & control ; Oxidative Stress ; drug effects ; PPAR gamma ; antagonists & inhibitors ; Rats ; Reperfusion Injury ; prevention & control ; Tumor Necrosis Factor-alpha ; metabolism

Inflammation plays a critical role in intestinal ischemia reperfusion injury (IRI). Epigallocatechin-3-gallate (EGCG) has been demonstrated to possess anti-inflammatory effect. This study examined the effect of EGCG on intestinal IRI and explored the possible mechanisms. Male Wistar rats were randomly divided into three groups: sham-operated group (Sham), IRI control group (IRI) and IRI-EGCG group (EGCG). Rats in IRI-EGCG group were administered dissolved EGCG in drinking water (0.4 mg/mL) for 14 days prior to IRI induction. A rat model of intestinal IRI was established by ligating the superior mesenteric artery (SMA) for 30 min, followed by reperfusion for 1 h. Intestinal histology, pro-inflammatory cytokines and mediators were examined and the effect of EGCG on PI3K/Akt signalling was assessed. EGCG significantly alleviated the pathological changes of the intestine and suppressed the IRI-induced up-regulation of TNF-α, IL-1 and IL-6 mRNA and protein expression in the serum and intestine. The mechanism might be that EGCG enhanced the activation of PI3K/Akt signalling pathway. In conclusion, the administration of EGCG can significantly mitigate the acute intestinal IRI in rats by enhancing the activation of PI3K/Akt signalling pathway to suppress inflammatory response and might be a promising alternative for the prevention or treatment of intestinal IRI in the clinical practice.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; pharmacology ; Catechin ; administration & dosage ; analogs & derivatives ; pharmacology ; Disease Models, Animal ; Gene Expression Regulation ; drug effects ; Interleukin-1 ; genetics ; metabolism ; Interleukin-6 ; genetics ; metabolism ; Intestines ; drug effects ; pathology ; Male ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Wistar ; Reperfusion Injury ; genetics ; metabolism ; prevention & control ; Signal Transduction ; drug effects ; Tumor Necrosis Factor-alpha ; genetics ; metabolism

OBJECTIVETo investigate the protective effect of propofol against focal cerebral ischemia/reperfusion (I/R) injury in rats and its relation with gap junction.

METHODSSeventy adult male SD rats were randomly divided into sham-operated group, I/R group, low-, moderate-, and high-dose propofol groups (25, 50, 100 mg/kg; P25, P50, P100 groups, respectively), I/R+CBX group and P100+CBX group. Thread occlusion was used to induce middle cerebral artery occlusion (MCAO) in the mice for 2 h followed by reperfusion for 24 h. Longa's scores were used to evaluate the neurological behavior of the rats. TTC staining was used to measure the cerebral infarction volume and Western blotting was performed to detect the expressions of Cx43, PKC, Bax, and Bcl-2 in the brain of the rats.

RESULTSCompared with the I/R group, the rats pretreated with moderate and high doses of propofol showed significantly reduced neurological behavior scores and cerebral infarction volume percentage, and the effect was more obvious in high-dose propofol pretreatment group. CBX obviously enhanced the protective effect of propofol against I/R injury. Compared with those in the sham-operated group, the protein expression of Cx43 and the Bax/Bcl-2 ratio were increased and the protein expression of PKC was reduced in I/R group, and these changes were significantly reversed by high-dose propofol pretreatment; the effects of propofol were further enhanced by CBX.

CONCLUSIONThe protective effect of propofol against cerebral I/R injury may involve the inhibition of the gap junction via PKC signaling and by reducing the Bax/Bcl-2 ratio.

Animals ; Brain ; metabolism ; Brain Ischemia ; prevention & control ; Connexin 43 ; metabolism ; Gap Junctions ; Infarction, Middle Cerebral Artery ; Male ; Propofol ; pharmacology ; Protein Kinase C ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control ; Signal Transduction ; bcl-2-Associated X Protein ; metabolism

We investigated the protective effects of electromagnetic field (EMF) on the survival of the human renal proximal tubular cell line, HK-2, using an in vitro hypoxia/reoxygenation (H/R) injury model. The survival rate of cells cultured under H/R condition declined significantly, while the intracellular reactive oxygen species (ROS) levels markedly increased. The 10 Hz/1 mT EMF exposure reversed the H/R induced reduction in cell survival and induction of intracellular ROS. Our results suggest that 10 Hz/1 mT EMF exposure could inhibit H/R-induced cell death of HK-2 via suppression of intracellular ROS production and that this treatment might be clinically useful for the amelioration of renal ischemia/reperfusion injury.
Cell Hypoxia ; Cell Line ; Electromagnetic Fields ; Humans ; Kidney Tubules, Proximal ; cytology ; metabolism ; radiation effects ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; prevention & control