Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats.

PubMed

Kim, Eun Soo; Lee, Seung-Koo; Kwon, Mi Jung; Lee, Phil Hye; Ju, Young-Su; Yoon, Dae Young; Kim, Hye Jeong; Lee, Kwan Seop

2016-01-01

The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min(-1) vs. 0.07 ± 0.02 min(-1), p = 0.661 for K(trans); 0.30 ± 0.05 min(-1) vs. 0.37 ± 0.11 min(-1), p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group.

Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats

PubMed Central

Kim, Eun Soo; Kwon, Mi Jung; Lee, Phil Hye; Ju, Young-Su; Yoon, Dae Young; Kim, Hye Jeong; Lee, Kwan Seop

2016-01-01

Objective The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Materials and Methods Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Results Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min-1 vs. 0.07 ± 0.02 min-1, p = 0.661 for Ktrans; 0.30 ± 0.05 min-1 vs. 0.37 ± 0.11 min-1, p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Conclusion Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group. PMID:27587960

TIA model is attainable in Wistar rats by intraluminal occlusion of the MCA for 10min or shorter.

PubMed

Durukan Tolvanen, A; Tatlisumak, E; Pedrono, E; Abo-Ramadan, U; Tatlisumak, T

2017-05-15

Transient ischemic attack (TIA) has received only little attention in the experimental research field. Recently, we introduced a TIA model for mice, and here we set similar principles for simulating this human condition in Wistar rats. In the model: 1) transient nature of the event is ensured, and 2) 24h after the event animals are free from any sensorimotor deficit and from any detectable lesion by magnetic resonance imaging (MRI). Animals experienced varying durations of ischemia (5, 10, 12.5, 15, 25, and 30min, n=6-8pergroup) by intraluminal middle cerebral artery occlusion (MCAO). Ischemia severity and reperfusion rates were controlled by cerebral blood flow measurements. Sensorimotor neurological evaluations and MRI at 24h differentiated between TIA and ischemic stroke. Hematoxylin and eosin staining and apoptotic cell counts revealed pathological correlates of the event. We found that already 12.5min of ischemia was long enough to induce ischemic stroke in Wistar rats. Ten min or shorter durations induced neither gross neurological deficits nor infarcts visible on MRI, but histologically caused selective neuronal necrosis. A separate group of animals with 10min of ischemia followed up to 1week after reperfusion remained free of infarction and any MRI signal change. Thus, 10min or shorter focal cerebral ischemia induced by intraluminal MCAO in Wistar rats provides a clinically relevant TIA the rat. This model is useful for studying molecular correlates of TIA. Copyright © 2017 Elsevier B.V. All rights reserved.

Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

PubMed

Kelsen, Jesper; Kjaer, Katrine; Chen, Gang; Pedersen, Michael; Røhl, Lisbeth; Frøkiaer, Jørgen; Nielsen, Søren; Nyengaard, Jens R; Rønn, Lars Christian B

2006-12-06

Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo). Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator. We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related

Optimization of a therapeutic protocol for intravenous injection of human mesenchymal stem cells after cerebral ischemia in adult rats.

PubMed

Omori, Yoshinori; Honmou, Osamu; Harada, Kuniaki; Suzuki, Junpei; Houkin, Kiyohiro; Kocsis, Jeffery D

2008-10-21

The systemic injection of human mesenchymal stem cells (hMSCs) prepared from adult bone marrow has therapeutic benefits after cerebral artery occlusion in rats, and may have multiple therapeutic effects at various sites and times within the lesion as the cells respond to a particular pathological microenvironment. However, the comparative therapeutic benefits of multiple injections of hMSCs at different time points after cerebral artery occlusion in rats remain unclear. In this study, we induced middle cerebral artery occlusion (MCAO) in rats using intra-luminal vascular occlusion, and infused hMSCs intravenously at a single 6 h time point (low and high cell doses) and various multiple time points after MCAO. From MRI analyses lesion volume was reduced in all hMSC cell injection groups as compared to serum alone injections. However, the greatest therapeutic benefit was achieved following a single high cell dose injection at 6 h post-MCAO, rather than multiple lower cell infusions over multiple time points. Three-dimensional analysis of capillary vessels in the lesion indicated that the capillary volume was equally increased in all of the cell-injected groups. Thus, differences in functional outcome in the hMSC transplantation subgroups are not likely the result of differences in angiogenesis, but rather from differences in neuroprotective effects.

Quercetin attenuates neuronal cells damage in a middle cerebral artery occlusion animal model.

PubMed

Park, Dong-Ju; Shah, Fawad-Ali; Koh, Phil-Ok

2018-04-27

Cerebral ischemia is a neurological disorder with high mortality. Quercetin is a flavonoid compound that is abundant in vegetables and fruits. It exerts anti-inflammatory and anti-apoptotic effects. This study investigated the neuroprotective effects of quercetin in focal cerebral ischemia. Male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) to induce focal cerebral ischemia. Quercetin or vehicle was injected 30 min before the onset of ischemia. A neurological function test, brain edema measurement, and 2,3,5-triphenyltetrazolium chloride staining were performed to elucidate the neuroprotective effects of quercetin. Western blot analysis was performed to observe caspase-3 and poly ADP-ribose polymerase (PARP) protein expression. MCAO leads to severe neuronal deficits and increases brain edema and infarct volume. However, quercetin administration attenuated the MCAO-induced neuronal deficits and neuronal degeneration. We observed increases in caspase-3 and PARP protein levels in MCAO-operated animals injected with vehicle, whereas quercetin administration attenuated these increases in MCAO injury. This study reveals the neuroprotective effect of quercetin in an MCAO-induced animal model and demonstrates the regulation of caspase-3 and PARP expression by quercetin treatment. These results suggest that quercetin exerts a neuroprotective effect through preventing the MCAO-induced activation of apoptotic pathways affecting caspase-3 and PARP expression.

Stroke treatment in rats with tail temperature increase by 40-min moxibustion.

PubMed

Chen, Ri-Xin; Lv, Zhi-Mai; Chen, Ming-Ren; Yi, Fan; An, Xin; Xie, Ding-Yi

2011-10-03

The distant heat induced by suspended moxibustion (SM) for 40 min is confirmed to have a favorable effect in treating diseases such as ischemic brain injury in the clinical setting, but its precise mechanism remains to be explained. Since a similar reaction to the phenomenon of distant heat is found in some transient middle cerebral artery occlusion (tMCAO) rats treated by a 40-min SM session with tail temperature increase (TTI), we hereby study its mechanism by comparing the neuroprotective effect of 40 min's SM with TTI to those without. The experimental results show that 40 min's SM with TTI can significantly reduce the infarct volume and neurological deficit score in tMCAO rats. Western blot demonstrates that a reduction in the levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) expression in tMCAO rats with TTI is more striking than that of the rats without TTI. The expression of caspase-3 protein is inhibited in tMCAO rats with TTI. The results suggest that the efficacy of SM for 40 min with TTI is higher than that without. Although neuroprotective effects present in tMCAO rats with and without TTI, those with TTI revealed a higher level of anti-inflammation effect and exhibited an anti-apoptosis effect. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Perillyl alcohol improves functional and histological outcomes against ischemia-reperfusion injury by attenuation of oxidative stress and repression of COX-2, NOS-2 and NF-κB in middle cerebral artery occlusion rats.

PubMed

Tabassum, Rizwana; Vaibhav, Kumar; Shrivastava, Pallavi; Khan, Andleeb; Ahmed, Mohd Ejaz; Ashafaq, Mohammad; Khan, M Badruzzaman; Islam, Farah; Safhi, Mohammed M; Islam, Fakhrul

2015-01-15

Perillyl alcohol (PA) is a monoterpene found in essential oils of mints, cherries, citreous fruits and lemon grass, reported to have antioxidant and anti-inflammatory properties. However, the role of PA in stroke is still illusive. Since oxidative stress and inflammation play a pivotal role in ischemia-reperfusion (I-R) injury, this study was designed to elucidate the potential effects of PA against I-R induced pathology in rat׳s brain. Middle cerebral artery occlusion (MCAO) for 2h followed by 22h reperfusion in Wistar male rats (250-280g, 14-16 weeks old) induced the behavioral and histological alterations along with exhausted antioxidant status and enhanced inflammatory mediators. However, PA administration (25, 50 and 100mg/kg b.wt orally once daily for 7 days) prior to MCAO significantly attenuated neurological deficits related to flexion test and spontaneous motor activity, improved grip strength and motor coordination in a dose dependent manner. PA treatment also inhibited oxidative stress in MCAO rats as evident from decreased lipid peroxidation and augmented level of reduced glutathione and restored activities of catalase, glutathione peroxidase, and glutathione reductase and thus, reduced infarct volume and protected the brain histology after I-R injury. Furthermore, PA markedly suppressed the level of proinflammatory cytokines (IL-1β, TNF α and IL-6) and down regulated expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (NOS-2) and nuclear factor κB (NF-κB) in MCAO group. In conclusion, PA mediates neuroprotection against I-R injury via mitigation of oxidative stress and inflammation and thus, may be a good therapeutic approach in stroke prone patient. Copyright © 2014 Elsevier B.V. All rights reserved.

JM-20 Treatment After MCAO Reduced Astrocyte Reactivity and Neuronal Death on Peri-infarct Regions of the Rat Brain.

PubMed

Ramírez-Sánchez, Jeney; Pires, Elisa Nicoloso Simões; Meneghetti, André; Hansel, Gisele; Nuñez-Figueredo, Yanier; Pardo-Andreu, Gilberto L; Ochoa-Rodríguez, Estael; Verdecia-Reyes, Yamila; Delgado-Hernández, René; Salbego, Christianne; Souza, Diogo O

2018-05-03

Stroke is frequently associated with severe neurological decline and mortality, and its incidence is expected to increase due to aging population. The only available pharmacological treatment for cerebral ischemia is thrombolysis, with narrow therapeutic windows. Efforts aimed to identify new therapeutics are crucial. In this study, we look into plausible molecular and cellular targets for JM-20, a new hybrid molecule, against ischemic stroke in vivo. Male Wistar rats were subjected to 90 min middle cerebral artery occlusion (MCAO) following 23 h of reperfusion. Animals treated with 8 mg/kg JM-20 (p.o., 1 h after reperfusion) showed minimal neurological impairment and lower GABA and IL-1β levels in CSF when compared to damaged rats that received vehicle. Immunocontent of pro-survival, phosphorylated Akt protein decreased in the cortex after 24 h as result of the ischemic insult, accompanied by decreased number of NeuN + cells in the peri-infarct cortex, cornu ammonis 1 (CA1) and dentate gyrus (DG) areas. Widespread reactive astrogliosis in both cortex and hippocampus (CA1, CA3, and DG areas) was observed 24 h post-ischemia. JM-20 prevented the activated Akt reduction, neuronal death, and astrocytes reactivity throughout the brain. Overall, the results reinforce the pharmacological potential of JM-20 as neuroprotective agent and provide important evidences about its molecular and cellular targets in this model of cerebral ischemia.

Progesterone treatment shows greater protection in brain vs. retina in a rat model of middle cerebral artery occlusion: Progesterone receptor levels may play an important role

PubMed Central

Allen, Rachael S.; Sayeed, Iqbal; Oumarbaeva, Yuliya; Morrison, Katherine C.; Choi, Paul H.; Pardue, Machelle T.; Stein, Donald G.

2018-01-01

Background/Objective To determine whether inflammation increases in retina as it does in brain following middle cerebral artery occlusion (MCAO), and whether the neurosteroid progesterone, shown to have protective effects in both retina and brain after MCAO, reduces inflammation in retina as well as brain. Methods MCAO rats treated systemically with progesterone or vehicle were compared with shams. Protein levels of cytosolic NF-κB, nuclear NF-κB, phosphorylated NF-κB, IL-6, TNF-α, CD11b, progesterone receptor A and B, and pregnane × receptor were assessed in retinas and brains at 24 and 48 h using western blots. Results Following MCAO, significant increases were observed in the following inflammatory markers: pNF-κB and CD11b at 24 h in both brain and retina, nuclear NF-κB at 24 h in brain and 48 h in retina, and TNF-α at 24 h in brain. Progesterone treatment in MCAO animals significantly attenuated levels of the following markers in brain: pNF-κB, nuclear NF-κB, IL-6, TNF-α, and CD11b, with significantly increased levels of cytosolic NF-κB. Retinas from progesterone-treated animals showed significantly reduced levels of nuclear NF-κB and IL-6 and increased levels of cytosolic NF-κB, with a trend for reduction in other markers. Post-MCAO, progesterone receptors A and B were upregulated in brain and downregulated in retina. Conclusion Inflammatory markers increased in both brain and retina after MCAO, with greater increases observed in brain. Progesterone treatment reduced inflammation, with more dramatic reductions observed in brain than retina. This differential effect may be due to differences in the response of progesterone receptors in brain and retina after injury. PMID:27802245

Regulatory T cells accumulate and proliferate in the ischemic hemisphere for up to 30 days after MCAO.

PubMed

Stubbe, Tobias; Ebner, Friederike; Richter, Daniel; Engel, Odilo; Randolf Engel, Odilo; Klehmet, Juliane; Royl, Georg; Meisel, Andreas; Nitsch, Robert; Meisel, Christian; Brandt, Christine

2013-01-01

Local and peripheral immune responses are activated after ischemic stroke. In our present study, we investigated the temporal distribution, location, induction, and function of regulatory T cells (Tregs) and the possible involvement of microglia, macrophages, and dendritic cells after middle cerebral artery occlusion (MCAO). C57BL/6J and Foxp3(EGFP) transgenic mice were subjected to 30 minutes MCAO. On days 7, 14, and 30 after MCAO, Tregs and antigen presenting cells were analyzed using fluorescence activated cell sorting multicolor staining and immunohistochemistry. A strong accumulation of Tregs was observed on days 14 and 30 in the ischemic hemisphere accompanied by the elevated presence and activation of microglia. Dendritic cells and macrophages were found on each analyzed day. About 60% of Foxp3(+) Tregs in ischemic hemispheres were positive for the proliferation marker Ki-67 on days 7 and 14 after MCAO. The transfer of naive CD4(+) cells depleted of Foxp3(+) Tregs into RAG1(-/-) mice 1 day before MCAO did not lead to a de novo generation of Tregs 14 days after surgery. After depletion of CD25(+) Tregs, no changes regarding neurologic outcome were detected. The sustained presence of Tregs in the brain after MCAO indicates a long-lasting immunological alteration and involvement of brain cells in immunoregulatory mechanisms.

Progesterone treatment shows greater protection in brain vs. retina in a rat model of middle cerebral artery occlusion: Progesterone receptor levels may play an important role.

PubMed

Allen, Rachael S; Sayeed, Iqbal; Oumarbaeva, Yuliya; Morrison, Katherine C; Choi, Paul H; Pardue, Machelle T; Stein, Donald G

2016-11-22

To determine whether inflammation increases in retina as it does in brain following middle cerebral artery occlusion (MCAO), and whether the neurosteroid progesterone, shown to have protective effects in both retina and brain after MCAO, reduces inflammation in retina as well as brain. MCAO rats treated systemically with progesterone or vehicle were compared with shams. Protein levels of cytosolic NF-κB, nuclear NF-κB, phosphorylated NF-κB, IL-6, TNF-α, CD11b, progesterone receptor A and B, and pregnane X receptor were assessed in retinas and brains at 24 and 48 h using western blots. Following MCAO, significant increases were observed in the following inflammatory markers: pNF-κB and CD11b at 24 h in both brain and retina, nuclear NF-κB at 24 h in brain and 48 h in retina, and TNF-α at 24 h in brain.Progesterone treatment in MCAO animals significantly attenuated levels of the following markers in brain: pNF-κB, nuclear NF-κB, IL-6, TNF-α, and CD11b, with significantly increased levels of cytosolic NF-κB. Retinas from progesterone-treated animals showed significantly reduced levels of nuclear NF-κB and IL-6 and increased levels of cytosolic NF-κB, with a trend for reduction in other markers. Post-MCAO, progesterone receptors A and B were upregulated in brain and downregulated in retina. Inflammatory markers increased in both brain and retina after MCAO, with greater increases observed in brain. Progesterone treatment reduced inflammation, with more dramatic reductions observed in brain than retina. This differential effect may be due to differences in the response of progesterone receptors in brain and retina after injury.

6-Mercaptopurine exerts an immunomodulatory and neuroprotective effect on permanent focal cerebral occlusion in rats.

PubMed

Chang, Chih-Zen; Kwan, Aij-Lie; Howng, Shen-Long

2010-08-01

A bursting cascade of inflammation imposes progressive neurological deterioration after experimental stroke has been demonstrated. In our study, 6-mercaptopurine (6-mp) has been successful in alleviating cerebral infarct in a rodent permanent middle cerebral artery occlusion (pMCAO) model. The present study was aimed to examine the effect of 6-mp on cytokine levels in experimental stroke. The rodent pMCAO model was employed. A dose of 2 mg/kg 6-mp or vehicle (0.1 mol/L PBS) was administered intraperitoneally 30 min after the induction of pMCAO. Neurological score, serum, and cerebrospinal fluid (CSF) cytokines such as IL-1beta, IL-6, and TNF-alpha and infarct volume were determined 48 h after pMCAO. Cerebral infarction volume was significantly decreased in animals treated with 6-mp (74.3%, p < 0.01), and the ratio of tissue edema was also decreased in 6-mp-treated groups (71%). Animals receiving 6-mp thus showed a significant decrease in IL-1 and TNF-alpha (18/43% and 48/64% in CSF/serum, respectively) when compared with the pMCAO groups (p < 0.01). This study demonstrates that 6-mp interposes the production of IL-1 and TNF-alpha in CSF and serum, attenuates ischemic brain injury, and thus alleviates neurological deficits in the pMCAO animals. These findings also offer first evidence that 6-mp may attenuate TNF-alpha-related neuron apoptosis and also support the notion that 6-mp and other anti-inflammatory agents could potentially have therapeutic uses in cases of cerebral infarct.

Regulatory T cells accumulate and proliferate in the ischemic hemisphere for up to 30 days after MCAO

PubMed Central

Stubbe, Tobias; Ebner, Friederike; Richter, Daniel; Randolf Engel, Odilo; Klehmet, Juliane; Royl, Georg; Meisel, Andreas; Nitsch, Robert; Meisel, Christian; Brandt, Christine

2013-01-01

Local and peripheral immune responses are activated after ischemic stroke. In our present study, we investigated the temporal distribution, location, induction, and function of regulatory T cells (Tregs) and the possible involvement of microglia, macrophages, and dendritic cells after middle cerebral artery occlusion (MCAO). C57BL/6J and Foxp3EGFP transgenic mice were subjected to 30 minutes MCAO. On days 7, 14, and 30 after MCAO, Tregs and antigen presenting cells were analyzed using fluorescence activated cell sorting multicolor staining and immunohistochemistry. A strong accumulation of Tregs was observed on days 14 and 30 in the ischemic hemisphere accompanied by the elevated presence and activation of microglia. Dendritic cells and macrophages were found on each analyzed day. About 60% of Foxp3+ Tregs in ischemic hemispheres were positive for the proliferation marker Ki-67 on days 7 and 14 after MCAO. The transfer of naive CD4+ cells depleted of Foxp3+ Tregs into RAG1−/− mice 1 day before MCAO did not lead to a de novo generation of Tregs 14 days after surgery. After depletion of CD25+ Tregs, no changes regarding neurologic outcome were detected. The sustained presence of Tregs in the brain after MCAO indicates a long-lasting immunological alteration and involvement of brain cells in immunoregulatory mechanisms. PMID:22968321

Protective Effect of Ischemic Preconditioning on Myocardium Against Remote Tissue Injury Following Transient Focal Cerebral Ischemia in Diabetic Rats

PubMed Central

Kumas, Meltem; Altintas, Ozge; Karatas, Ersin; Kocyigit, Abdurrahim

2017-01-01

Background Remote ischemic preconditioning (IPreC) could provide tissue-protective effect at a remote site by anti-inflammatory, neuronal, and humoral signaling pathways. Objectives The aim of the study was to investigate the possible protective effects of remote IPreC on myocardium after transient middle cerebral artery occlusion (MCAo) in streptozotocin- induced diabetic (STZ) and non-diabetic rats. Methods 48 male Spraque Dawley rats were divided into eight groups: Sham, STZ, IPreC, MCAo, IPreC+MCAo, STZ+IPreC, STZ+MCAo and STZ+IPreC+MCAo groups. We induced transient MCAo seven days after STZ-induced diabetes, and performed IPreC 72 hours before transient MCAo. Remote myocardial injury was investigated histopathologically. Bax, Bcl2 and caspase-3 protein levels were measured by Western blot analysis. Total antioxidant status (TAS), total oxidant status (TOS) of myocardial tissue were measured by colorimetric assay. Oxidative stress index(OSI) was calculated as TOS-to-TAS ratio. For all statistical analysis, p values < 0.05 were considered significant. Results We observed serious damage including necrosis, congestion and mononuclear cell infiltration in myocardial tissue of the diabetic and ischemic groups. In these groups TOS and OSI levels were significantly higher; TAS levels were lower than those of IPreC related groups (p < 0.05). IPreC had markedly improved histopathological alterations and increased TAS levels in IPreC+MCAo and STZ+IPreC+MCAo compared to MCAo and STZ+MCAo groups (p < 0.05). In non-diabetic rats, MCAo activated apoptotic cell death via increasing Bax/Bcl2 ratio and caspase-3 levels. IPreC reduced apoptotic cell death by suppressing pro-apoptotic proteins. Diabetes markedly increased apoptotic protein levels and the effect did not reversed by IPreC. Conclusions We could suggest that IPreC attenuates myocardial injury via ameliorating histological findings, activating antioxidant mechanisms, and inducing antiapoptotic activity in diabetic

Protective effects of alkaloid extract from Leonurus heterophyllus on cerebral ischemia reperfusion injury by middle cerebral ischemic injury (MCAO) in rats.

PubMed

Liang, Hao; Liu, Ping; Wang, Yunshan; Song, Shuliang; Ji, Aiguo

2011-07-15

The neuronal damage following cerebral ischemia is a serious risk to stroke patients. The aim of this study was to investigate the neuroprotective effects of alkaloid extract from Leonurus heterophyllus (LHAE) on cerebral ischemic injury. After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), some rats were intraperitoneally administered different doses of LHAE (3.6, 7.2, 14.4 mg/kg, respectively). Neurological examination was measured in all animals. Infarct volume, myeloperoxidase (MPO) activity, levels of nitrate/nitrite metabolite (NO) and apoptosis ratio of nerve fiber in brain were determined. The results showed that LHAE at 7.2 mg/kg or 14.4 mg/kg exerted significantly decreasing neurological deficit scores and reducing the infarct volume on rats with focal cerebral ischemic injury (p<0.05). At those dose, the MPO content were significantly decreased in ischemic brain as compared with model group (p<0.05). LHAE at 14.4 mg/kg significantly decreased the NO level compared with the model group (p<0.05). In addition, LHAE significantly decreased the apoptosis ratio of nerve fiber compared with the model group (p<0.05). This study suggests that LHAE may be used for treatment of ischemic stroke as a neuroprotective agent. Further studies are warranted to assess the efficacy and safety of LHAE in patients. Copyright © 2011 Elsevier GmbH. All rights reserved.

Neuroprotective effect of electroacupuncture and upregulation of hypoxia-inducible factor-1α during acute ischaemic stroke in rats.

PubMed

Li, Ce; Zhang, Tingting; Yu, Kewei; Xie, Hongyu; Bai, Yulong; Zhang, Li; Wu, Yi; Wang, Nianhong

2017-10-01

Acupuncture is a traditional method that has been widely used in various fields of medicine with therapeutic effect. However, evidence of effectiveness to support the application of electroacupuncture (EA) during the process of ischaemia is scarce. To investigate dynamic changes in hypoxia-inducible factor (HIF)-1α expression as well as its association with neurological status in rats subjected to acute ischaemic stroke and EA intervention. Forty adult male rats were randomly divided into three groups that received sham surgery (Control group, n=10) or underwent middle cerebral artery occlusion and EA (MCAO+EA group, n=15) or minimal acupuncture as a control treatment (MCAO+MA group, n=15). The rats in the MCAO+EA and MCAO+MA groups received EA or acupuncture without any electrical current, respectively, during 90 min of ischaemia. Rats in the Control group received the same surgical procedure but without MCAO. EA involved electrical stimulation of needles inserted into the quadriceps at 50 Hz frequency and 3 mA current intensity. Neurological status was evaluated on postoperative day 1, and cerebral infarction volume (IV) and HIF-1α expression 24 hours later. Neurological scores were improved and cerebral IV was decreased in the MCAO+EA group compared to the MCAO+MA group (both p<0.05). Moreover, HIF-1α expression was higher in the MCAO+EA group versus the MCAO+MA group (p<0.05). EA enhanced recovery of neurological function, decreased cerebral IV and increased HIF-1α expression in ischaemic rats. Further research is needed to determine whether EA is effective for stroke treatment through the stimulation of muscle contraction. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of activation of the Ca(2+)-permeable acid-sensing ion channel 1a on focal cerebral ischemia in diabetic rats.

PubMed

Wang, Jie; Wen, Chun-Yan; Cui, Cui-Cui; Xing, Ying

2015-01-01

We investigated the role of acid-sensing ion channel Ia (ASIC1a) expression and changes in intracellular Ca(2+) concentration ([Ca(2+)]) in focal cerebral ischemia after middle cerebral artery occlusion (MCAO) in a rat model of diabetes mellitus (DM). Male Wistar rats (n = 108) were divided into three groups: the MCAO, DM + MCAO, and DM + MCAO + fasudil groups (n = 36 each). Samples were obtained 1, 3, 6, and 24 h after ischemia induction (n = 9). Rats in the DM + MCAO + fasudil group were treated with 1 mg/kg fasudil, a Rho-kinase inhibitor, by caudal vein injection 30 min after MCAO was performed. ASIC1a expression gradually increased with time in the MCAO and DM + MCAO groups (0.71 ± 0.10 nM, 0.80 ± 0.11 nM, 0.86 ± 0.08 nM, 0.93 ± 0.09 nM; 0.86 ± 0.11 nM, 1.05 ± 0.51 nM, 2.42 ± 0.08 nM, 2.78 ± 0.04 nM; pairwise comparisons at each time point, P < 0.05), and was higher in the DM + MCAO than the MCAO group (P < 0.05). [Ca(2+)] gradually increased in the DM + MCAO group (106.32 ± 18.6 nM, 137.84 ± 14.32 nM, 151.94 ± 18.38 nM, 183.61 ± 7.96 nM, P < 0.05). ASIC1a expression and calcium currents were reduced in the DM + MCAO + fasudil group. The overload of intracellular [Ca(2+)] caused by ASIC1a activation could be one mechanism for the aggravation of focal cerebral ischemia in diabetes.

The TNFα-Transgenic Rat: Hippocampal Synaptic Integrity, Cognition, Function, and Post-Ischemic Cell Loss

PubMed Central

Pettigrew, L. Creed; Kryscio, Richard J.; Norris, Christopher M.

2016-01-01

The cytokine, tumor necrosis factor α (TNFα), is a key regulator of neuroinflammation linked to numerous neurodegenerative conditions and diseases. The present study used transgenic rats that overexpress a murine TNFα gene, under the control of its own promoter, to investigate the impact of chronically elevated TNFα on hippocampal synaptic function. Neuronal viability and cognitive recovery in TNFα Tg rats were also determined following an ischemic insult arising from reversible middle cerebral artery occlusion (MCAO). Basal CA3-CA1 synaptic strength, recorded in acute brain slices, was not significantly different between eight-week-old TNFα Tg rats and non-Tg rats. In contrast, slices from TNFα Tg rats showed significantly greater levels of long-term potentiation (LTP) in response to 100 Hz stimulation, suggesting that synaptic networks may be hyperexcitable in the context of elevated TNFα. Cognitive and motor deficits (assessed on the Morris Water Maze and Rotarod task, respectively) were present in TNFα Tg rats in the absence of significant differences in the loss of cortical and hippocampal neurons. TNF overexpression exacerbated MCAO-dependent deficits on the rotarod, but ameliorated cortical neuron loss in response to MCAO. PMID:27144978

In vivo MRI assessment of permanent middle cerebral artery occlusion by electrocoagulation: pitfalls of procedure

PubMed Central

2010-01-01

Permanent middle cerebral artery (MCA) occlusion (pMCAO) by electrocoagulation is a commonly used model but with potential traumatic lesions. Early MRI monitoring may assess pMCAO for non-specific brain damage. The surgical steps of pMCAO were evaluated for traumatic cerebral injury in 22 Swiss mice using diffusion and T2-weighted MRI (7T) performed within 1 h and 24 h after surgery. Temporal muscle cauterization without MCA occlusion produced an early T2 hyperintensity mimicking an infarct. No lesion was visible after temporal muscle incision or craniotomy. Early MRI monitoring is useful to identify non-specific brain injury that could hamper neuroprotective drugs assessment. PMID:20298536

Effect of activation of the Ca2+-permeable acid-sensing ion channel 1a on focal cerebral ischemia in diabetic rats

PubMed Central

Wang, Jie; Wen, Chun-Yan; Cui, Cui-Cui; Xing, Ying

2015-01-01

We investigated the role of acid-sensing ion channel Ia (ASIC1a) expression and changes in intracellular Ca2+ concentration ([Ca2+]) in focal cerebral ischemia after middle cerebral artery occlusion (MCAO) in a rat model of diabetes mellitus (DM). Male Wistar rats (n = 108) were divided into three groups: the MCAO, DM + MCAO, and DM + MCAO + fasudil groups (n = 36 each). Samples were obtained 1, 3, 6, and 24 h after ischemia induction (n = 9). Rats in the DM + MCAO + fasudil group were treated with 1 mg/kg fasudil, a Rho-kinase inhibitor, by caudal vein injection 30 min after MCAO was performed. ASIC1a expression gradually increased with time in the MCAO and DM + MCAO groups (0.71 ± 0.10 nM, 0.80 ± 0.11 nM, 0.86 ± 0.08 nM, 0.93 ± 0.09 nM; 0.86 ± 0.11 nM, 1.05 ± 0.51 nM, 2.42 ± 0.08 nM, 2.78 ± 0.04 nM; pairwise comparisons at each time point, P < 0.05), and was higher in the DM + MCAO than the MCAO group (P < 0.05). [Ca2+] gradually increased in the DM + MCAO group (106.32 ± 18.6 nM, 137.84 ± 14.32 nM, 151.94 ± 18.38 nM, 183.61 ± 7.96 nM, P < 0.05). ASIC1a expression and calcium currents were reduced in the DM + MCAO + fasudil group. The overload of intracellular [Ca2+] caused by ASIC1a activation could be one mechanism for the aggravation of focal cerebral ischemia in diabetes. PMID:26722526

Neuroprotection by dimethyloxalylglycine following permanent and transient focal cerebral ischemia in rats

PubMed Central

Nagel, Simon; Papadakis, Michalis; Chen, Ruoli; Hoyte, Lisa C; Brooks, Keith J; Gallichan, Daniel; Sibson, Nicola R; Pugh, Chris; Buchan, Alastair M

2011-01-01

Dimethyloxalylglycine (DMOG) is an inhibitor of prolyl-4-hydroxylase domain (PHD) enzymes that regulate the stability of hypoxia-inducible factor (HIF). We investigated the effect of DMOG on the outcome after permanent and transient middle cerebral artery occlusion (p/tMCAO) in the rat. Before and after pMCAO, rats were treated with 40 mg/kg, 200 mg/kg DMOG, or vehicle, and with 40 mg/kg or vehicle after tMCAO. Serial magnetic resonance imaging (MRI) was performed to assess infarct evolution and regional cerebral blood flow (rCBF). Both doses significantly reduced infarct volumes, but only 40 mg/kg improved the behavior after 24 hours of pMCAO. Animals receiving 40 mg/kg were more likely to maintain rCBF values above 30% from the contralateral hemisphere within 24 hours of pMCAO. DMOG after tMCAO significantly reduced the infarct volumes and improved behavior at 24 hours and 8 days and also improved the rCBF after 24 hours. A consistent and significant upregulation of both mRNA and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) was associated with the observed neuroprotection, although this was not consistently related to HIF-1α levels at 24 hours and 8 days. Thus, DMOG afforded neuroprotection both at 24 hours after pMCAO and at 24 hours and 8 days after tMCAO. This effect was associated with an increase of VEGF and eNOS and was mediated by improved rCBF after DMOG treatment. PMID:20407463

[Focal cerebral ischemia in rats with estrogen deficiency and endothelial dysfunction].

PubMed

Litvinov, A A; Volotova, E V; Kurkin, D V; Logvinova, E O; Darmanyan, A P; Tyurenkov, I N

2017-01-01

To assess an effect of ovariectomy (OE) on the cerebral blood flow, endothelium-dependent vasodilation, neurological, cognitive and locomotor deficit as markers of brain damage after focal ischemia in rats. The study was conducted in 48 female Wistar rats. Ovariectomy was performed with ovaries and uterine body extirpation, cerebral ischemia was performed by middle cerebral artery occlusion (MCAO) in rats. To assess brain damage, Combs and Garcia scores, 'open field' test (OFT), 'extrapolatory escape test' (EET), 'passive avoidance test' (PAT), 'beam-walking test' were used. Cerebral blood flow was measured using ultrasonic flowmetry. After 7 days of MCAO, the cerebral blood flow in ovarioectomized animals was reduced by 20% compared to sham-ovariectomized animals. Ovariectomized animals with MCAO showed a three-fold endothelium-dependent vasodilation reduction (the reaction of cerebral vessels to the introduction of acetylcholine and N-L-arginine), indicating the presence of severe endothelial dysfunction. In ovarioectomized animals, the cerebral blood flow was reduced by 34% compared to sham-operated animals. MCAO and OE taken together resulted in more than 2-fold increase in neurological, motor disturbances, 3-fold decrease in motor activity of the animals in the OP test. Focal ischemia in ovarioectomized animals with endothelial dysfunction led to memory decrease by 1/5 fold in PAT and by 2-fold in EET.

Rat brain digital stereotaxic white matter atlas with fine tract delineation in Paxinos space and its automated applications in DTI data analysis.

PubMed

Liang, Shengxiang; Wu, Shang; Huang, Qi; Duan, Shaofeng; Liu, Hua; Li, Yuxiao; Zhao, Shujun; Nie, Binbin; Shan, Baoci

2017-11-01

To automatically analyze diffusion tensor images of the rat brain via both voxel-based and ROI-based approaches, we constructed a new white matter atlas of the rat brain with fine tracts delineation in the Paxinos and Watson space. Unlike in previous studies, we constructed a digital atlas image from the latest edition of the Paxinos and Watson. This atlas contains 111 carefully delineated white matter fibers. A white matter network of rat brain based on anatomy was constructed by locating the intersection of all these tracts and recording the nuclei on the pathway of each white matter tract. Moreover, a compatible rat brain template from DTI images was created and standardized into the atlas space. To evaluate the automated application of the atlas in DTI data analysis, a group of rats with right-side middle cerebral artery occlusion (MCAO) and those without were enrolled in this study. The voxel-based analysis result shows that the brain region showing significant declines in signal in the MCAO rats was consistent with the occlusion position. We constructed a stereotaxic white matter atlas of the rat brain with fine tract delineation and a compatible template for the data analysis of DTI images of the rat brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Decrease of tight junction integrity in the ipsilateral thalamus during the acute stage after focal infarction and ablation of the cerebral cortex in rats.

PubMed

Li, Jing-Jing; Xing, Shi-Hui; Zhang, Jian; Hong, Hua; Li, Yi-Liang; Dang, Chao; Zhang, Yu-Sheng; Li, Chuo; Fan, Yu-Hua; Yu, Jian; Pei, Zhong; Zeng, Jin-Sheng

2011-11-01

1. Whether damage to the blood-brain barrier (BBB) occurs in remote areas after a focal cortical lesion remains unknown. The present study investigated tight junction-related proteins and tight junction microstructure in the ipsilateral thalamus during the acute stage after middle cerebral artery occlusion (MCAO) and cortical aspiration lesion (CAL) in rats. 2. Thirty-six hypertensive and normotensive rats were subjected to MCAO or CAL; another 18 rats in each group were submitted to sham operation. Zonula Occluden (ZO)-1, occludin and albumin were detected by western blotting 12 and 24 h after surgery. Tight junction microstructure was evaluated using electron microscopy, whereas albumin location in the ipsilateral thalamus was determined using double immunostaining for albumin and occludin or albumin and neuronal nuclei (NeuN) 24 h after surgery. 3. Twenty-four hours after MCAO or CAL, occludin expression was reduced to 78.4% and 81.3%, respectively, compared with control. A reduction in ZO-1 expression in the ipsilateral thalamus (to 79%) was seen only after CAL (P < 0.05). Membrane contact at the tight junction was discontinuous in the ipsilateral thalamus in both MCAO and CAL rats. Albumin levels were 23.2% and 82.5% higher in the ipsilateral thalamus after MCAO and CAL, respectively (P < 0.05). The percentage of the albumin-positive area that coincided with the occludin-positive area in the MCAO and CAL groups was 76.8% and 64.6%, respectively, indicating that albumin was mainly localized around the microvessels. 4. The results of the present study suggest that tight junction integrity decreases during the acute stage in the ipsilateral thalamus after MCAO and CAL in rats. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

Korean red ginseng protects against neuronal damage induced by transient focal ischemia in rats

PubMed Central

BAN, JU YEON; KANG, SUNG WOOK; LEE, JONG SEOK; CHUNG, JOO-HO; KO, YOUNG GWAN; CHOI, HAN SUNG

2012-01-01

In the present study, we investigated the neuroprotective effect of Korean red ginseng (KRG) following focal brain ischemia/reperfusion injury, in relation to its antioxidant activities. The middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats was employed. The KRG extract (100 mg/kg, perorally) was administered once daily for 7 days following MCAO/R. The elevated levels of lipid peroxidation in the MCAO/R group were attenuated significantly in the KRG-administered group. The significantly depleted activity of the antioxidant enzymes glutathione peroxidase, superoxide dismutase and catalase was prevented in the KRG-administered group. In the neurobehavioral evaluation expressed as the modified neurological severity score and corner-turn test, the daily intake of KRG showed consistent and significant improvement in the neurological deficits for 7 days following MCAO/R injury. These results indicate that KRG has a neuroprotective effect against ischemia/reperfusion brain injury by reducing the level of lipid peroxidation and increasing the endogenous antioxidant enzymatic activity. PMID:22969953

-(S)-Alpha-phenyl-2-pyridine-ethanamine Dihydrochloride-, a low affinity uncompetitive N-methyl-D-aspartic acid antagonist, is effective in rodent models of global and focal ischemia.

PubMed

Cregan, E F; Peeling, J; Corbett, D; Buchan, A M; Saunders, J; Auer, R N; Gao, M; Mccarthy, D J; Eisman, M S; Campbell, T M; Murray, R J; Stagnitto, M L; Palmer, G C

1997-12-01

[(S)-Alpha-phenyl-2-pyridine-ethanamine dihydrochloride] (ARL 15896AR) is a low affinity uncompetitive N-methyl-D-aspartic acid receptor antagonist that was tested in animal models of anoxia and ischemia. Pretreatment of rodents with ARL 15896AR extended survival time during exposure to hypoxia. With the rat four-vessel occlusion model of global ischemia (20 min), oral dosing commencing at reflow, resulted in significant protection of the CA1 hippocampal neurons. ARL 15896AR was, however, ineffective in the rat two-vessel occlusion model and in the gerbil models of forebrain ischemia, the latter due to an inability to attain suitable plasma levels. In the spontaneously hypertensive rat model of middle cerebral artery occlusion (MCAO) (2 hr plus 22 hr reflow), acute dosing with ARL 15896AR (i.p.) beginning from 30 min before or up to 1 hr post-MCAO significantly reduced cortical infarct volume. The ability of ARL 15896AR to influence infarct size, as well as functional correlates was examined in SHR after 90 min of MCAO. T2 weighted magnetic resonance images taken at 2 and 6 days post-MCAO revealed significantly smaller lesion sizes in the group receiving injections with ARL 15896AR beginning 30 min after occlusion. Spontaneously hypertensive rats were subsequently tested (30-42 days post-MCAO) and found to be deficient in skilled use of the forepaws (staircase test). The contralateral forepaw was most severely impaired, however, ARL 15896AR treatment prevented motor impairment in only the ipsilateral forepaw. Histopathological examination of cortical infarct size was unremarkable between treated and control rats. The findings indicate that ARL 15896AR exhibits neuroprotection in global and focal models of ischemia

Ferulic acid regulates the AKT/GSK-3β/CRMP-2 signaling pathway in a middle cerebral artery occlusion animal model

PubMed Central

Gim, Sang-A; Sung, Jin-Hee; Shah, Fawad-Ali; Kim, Myeong-Ok

2013-01-01

Ferulic acid, a component of the plants Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort, exerts a neuroprotective effect by regulating various signaling pathways. This study showed that ferulic acid treatment prevents the injury-induced increase of collapsin response mediator protein 2 (CRMP-2) in focal cerebral ischemia. Glycogen synthase kinase-3β (GSK-3β) regulates CRMP-2 function through phosphorylation of CRMP-2. Moreover, the pro-apoptotic activity of GSK-3β is inactivated by phosphorylation by Akt. This study investigated whether ferulic acid modulates the expression of CRMP-2 and its upstream targets, Akt and GSK-3β, in focal cerebral ischemia. Male rats were treated immediately with ferulic acid (100 mg/kg, i.v.) or vehicle after middle cerebral artery occlusion (MCAO), and then cerebral cortices were collected 24 hr after MCAO. MCAO resulted in decreased levels of phospho-Akt and phospho-GSK-3β, while ferulic acid treatment prevented the decrease in the levels of these proteins. Moreover, phospho-CRMP-2 and CRMP-2 levels increased during MCAO, whereas ferulic acid attenuated these injury-induced increases. These results demonstrate that ferulic acid regulates the Akt/GSK-3β/CRMP-2 signaling pathway in focal cerebral ischemic injury, thereby protecting against brain injury. PMID:23825478

Role of the NMDA receptor and iron on free radical production and brain damage following transient middle cerebral artery occlusion.

PubMed

Im, Doo Soon; Jeon, Jeong Wook; Lee, Jin Soo; Won, Seok Joon; Cho, Sung Ig; Lee, Yong Beom; Gwag, Byoung Joo

2012-05-21

Excess activation of ionotropic glutamate receptors and iron is believed to contribute to free radical production and neuronal death following hypoxic ischemia. We examined the possibility that both NMDA receptor activation and iron overload determine spatial and temporal patterns of free radical production after transient middle cerebral artery occlusion (tMCAO) in male Sprague-Dawley rats. Mitochondrial free radical (MFR) levels were maximally increased in neurons in the core at 1 h and 24 h after tMCAO. Early MFR production was blocked by administration of MK-801, an NMDA receptor antagonist, but not deferoxamine, an iron chelator. Neither MK-801 nor deferoxamine attenuated late MFR production in the core. Increased MFRs were observed in penumbral neurons within 6 h and gradually increased over 24 h after tMCAO. Slowly-evolving MFRs in the core and penumbra were accompanied by iron overload. Deferoxamine blocked iron overload but reduced MFR production only in the penumbra. Combined MK-801/deferoxamine reduced late MFR production in both core and penumbra in an additive manner. Combination therapy significantly ameliorated infarction compared with monotherapy. These findings suggest that the NMDA receptor activation and iron overload mediate late MFR production and infarction after tMCAO. Copyright © 2012 Elsevier B.V. All rights reserved.

Potent sigma 1-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine provides ischemic neuroprotection without altering dopamine accumulation in vivo in rats.

PubMed

Goyagi, Toru; Bhardwaj, Anish; Koehler, Raymond C; Traystman, Richard J; Hurn, Patricia D; Kirsch, Jeffrey R

2003-02-01

The in vivo signaling of ischemic neuroprotection provided by sigma-receptor ligands remains unclear. Catecholamines have been implicated in the propagation of ischemic neuronal injury, and previous in vitro studies suggest that sigma ligands modulate dopaminergic neurotransmission. In this study, we tested the hypothesis that the potent sigma(1)-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine (PPBP) attenuates the increase of extracellular dopamine in ischemic striatum. Under controlled physiological conditions, a microdialysis probe was implanted in right caudoputamen (CP) complex of adult male Wistar rats. Rats were subjected to 2 h of transient middle cerebral artery occlusion (MCAO) by the intraluminal suture technique. In a blinded, randomized fashion, rats were divided into five treatment groups: Group 1 (n = 8; saline-saline) continuous i.v. infusion of saline vehicle 30 min before MCAO followed by saline at reperfusion until the end of the experiment; Group 2 (n = 8; PPBP-PPBP) i.v. PPBP 30 min before MCAO followed by 1 micromol x kg(-1) x h(-1) of PPBP; Group 3 (n = 8; saline-PPBP) i.v. saline before MCAO followed by PPBP; Group 4 (n = 4) surgical shams (saline-saline); and Group 5 (n = 4) surgical shams (PPBP-PPBP). Infarction volume at 22 h of reperfusion in the CP complex (percentage of ipsilateral structure) was significantly attenuated in rats treated with PPBP-PPBP (27.3% +/- 9.1%) and saline-PPBP (27.8% +/- 12.7%) compared with saline-saline (59.3% +/- 7.3%) treatment. There was a three- to fourfold increase in dopamine concentrations in the microdialysates within 40 min of the onset of MCAO. Dopamine and its metabolites dihydroxy phenylacetic acid and homovallinic acid levels were similar among the three groups subjected to MCAO. Therefore, PPBP provides significant ischemic neuroprotection in the CP complex without altering the acute accumulation of dopamine in vivo during transient focal ischemia in the rat.

Neuroprotective effects of chloroform and petroleum ether extracts of Nigella sativa seeds in stroke model of rat

PubMed Central

Akhtar, Mohammad; Maikiyo, Aliyu Muhammad; Najmi, Abul Kalam; Khanam, Razia; Mujeeb, Mohd; Aqil, Mohd

2013-01-01

PURPOSE: Stroke still remains a challenge for the researchers and scientists for developing ideal drug. Several new drugs are being evaluated showing excellent results in preclinical studies but when tested in clinical trials, they failed. Many herbal drugs in different indigenous system of medicine claim to have beneficial effects but not extensively evaluated for stroke (cerebral ischemia). AIM: The present study was undertaken to evaluate chloroform and petroleum ether extract of Nigella sativa seeds administered at a dose of 400 mg/kg, per orally for seven days in middle cerebral artery occluded (MCAO) rats for its neuroprotective role in cerebral ischemia. MATERIALS AND METHODS: Focal cerebral ischemia was induced by middle cerebral artery occlusion for two hours followed by reperfusion for 22 hours. After 24 hours, grip strength, locomotor activity tests were performed in different treatment groups of rats. After completing behavioral tests, animals were sacrificed; brains were removed for the measurement of infarct volume followed by the estimation of markers of oxidative stress. RESULTS: Both chloroform and petroleum ether extracts-pretreated rats showed improvement in locomotor activity and grip strength, reduced infarct volume when compared with MCAO rats. MCA occlusion resulted in the elevation of levels of thiobarbituric acid reactive substance (TBARS), while a reduction in the levels of glutathione (GSH) and antioxidant enzymes viz. superoxide dismutase (SOD) and catalase levels were observed. Pre-treatment of both extracts of Nigella sativa showed reduction in TBARS, elevation in glutathione, SOD, and catalase levels when compared with MCAO rats. CONCLUSION: The chloroform and petroleum ether extract of Nigella sativa showed the protective effects in cerebral ischemia. The present study confirms the antioxidant, free radical scavenging, and anti-inflammatory properties of Nigella sativa already reported. PMID:23833517

Niche astrocytes promote the survival, proliferation and neuronal differentiation of co-transplanted neural stem cells following ischemic stroke in rats

PubMed Central

Luo, Li; Guo, Kaihua; Fan, Wenguo; Lu, Yinghong; Chen, Lizhi; Wang, Yang; Shao, Yijia; Wu, Gongxiong; Xu, Jie; Lü, Lanhai

2017-01-01

Niche astrocytes have been reported to promote neuronal differentiation through juxtacrine signaling. However, the effects of astrocytes on neuronal differentiation following ischemic stroke are not fully understood. In the present study, transplanted astrocytes and neural stem cells (NSCs) were transplanted into the ischemic striatum of transient middle cerebral artery occlusion (MCAO) model rats 48 h following surgery. It was observed that the co-transplantation of astrocytes and NSCs resulted in a higher ratio of survival and proliferation of the transplanted NSCs, and neuronal differentiation, in MCAO rats compared with NSC transplantation alone. These results demonstrate that the co-administration of astrocytes promotes the survival and neuronal differentiation of NSCs in the ischemic brain. These results suggest that the co-transplantation of astrocytes and NSCs is more effective than NSCs alone in the production of neurons following ischemic stroke in rats. PMID:28352345

Multi-unit activity suppression and sensorimotor deficits after endothelin-1-induced middle cerebral artery occlusion in conscious rats.

PubMed

Moyanova, Slavianka; Kirov, Roumen; Kortenska, Lidia

2003-08-15

Conscious Wistar rats with stereotaxically and unilaterally implanted cannula just above the middle cerebral artery (MCA) were injected with the powerful vasoconstrictor peptide endothelin-1 (ET1, 60 pmol in 3 microl). The purpose was to examine the long-term (from the 1st to the 14th day) changes in neuronal bioelectrical activity together with sensorimotor deficits after ET1-induced MCA occlusion (MCAO). Extracellular multi-unit activity (MUA) recorded from the ipsilateral fronto-parietal cortical area (supplied by MCA) and sensorimotor behavior (one postural reflex test and six limb placing tests) were examined. A significant suppression of the multi-unit activity was observed until the 14th day post-ET1. The rats exhibited significant unilateral sensorimotor deficits with a maximum at the 3-7 days after ET1 and a spontaneous partial recovery by days 11-14. A significant correlation was found between the suppression of the multi-unit activity and the sensorimotor deficits between the 3rd and the 10th day post-ET1. The results suggest that studying the bioelectrical activity in combination with the behavioral sensorimotor functions may be of use to assess the functional disturbances associated with focal cerebral ischemia and would help to examine the therapeutic benefits of various cerebroprotective treatments before initiating human clinical trials.

Evolution of ischemic damage and behavioural deficit over 6 months after MCAo in the rat: Selecting the optimal outcomes and statistical power for multi-centre preclinical trials

PubMed Central

Churilov, Leonid; Sidon, T. Kate; Aleksoska, Elena; Cox, Susan F.; Macleod, Malcolm R.; Howells, David W.

2017-01-01

Key disparities between the timing and methods of assessment in animal stroke studies and clinical trial may be part of the reason for the failure to translate promising findings. This study investigates the development of ischemic damage after thread occlusion MCAo in the rat, using histological and behavioural outcomes. Using the adhesive removal test we investigate the longevity of behavioural deficit after ischemic stroke in rats, and examine the practicality of using such measures as the primary outcome for future studies. Ischemic stroke was induced in 132 Spontaneously Hypertensive Rats which were assessed for behavioural and histological deficits at 1, 3, 7, 14, 21, 28 days, 12 and 24 weeks (n>11 per timepoint). The basic behavioural score confirmed induction of stroke, with deficits specific to stroke animals. Within 7 days, these deficits resolved in 50% of animals. The adhesive removal test revealed contralateral neglect for up to 6 months following stroke. Sample size calculations to facilitate the use of this test as the primary experimental outcome resulted in cohort sizes much larger than are the norm for experimental studies. Histological damage progressed from a necrotic infarct to a hypercellular area that cleared to leave a fluid filled cavity. Whilst absolute volume of damage changed over time, when corrected for changes in hemispheric volume, an equivalent area of damage was lost at all timepoints. Using behavioural measures at chronic timepoints presents significant challenges to the basic science community in terms of the large number of animals required and the practicalities associated with this. Multicentre preclinical randomised controlled trials as advocated by the MultiPART consortium may be the only practical way to deal with this issue. PMID:28182727

Arctigenin protects focal cerebral ischemia-reperfusion rats through inhibiting neuroinflammation.

PubMed

Fan, Tao; Jiang, Wei Long; Zhu, Jian; Feng Zhang, Yu

2012-01-01

Stroke is the third leading cause of death in industrialized countries and the most important cause of acquired adult disability. Many evidences suggest that inflammation accounts for the progression of cerebral ischemic injury. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignin isolated from certain plants, has shown anti-inflammatory activity against diabetes and Alzheimer's disease. In this study, we tested whether arctigenin can protect middle cerebral artery occluded (MCAO) rats. Male Sprague-Dawley rats were pretreated with arctigenin or vehicle for 7 d before being subjected to transient occlusion of middle cerebral artery and reperfusion. Rats were evaluated at 24 h after MCAO for neurological deficit scoring. Furthermore, the mechanism of the anti-inflammatory effect of arctigenin was investigated with a focus on inflammatory cells, proinflammatory cytokines, and transcriptional factors. Arctigenin significantly reduced cerebral infarction and improved neurological outcome. Arctigenin suppressed the activation of microglia and decreased the expression of interleukin (IL)- 1β and tumor necrosis factor (TNF)-α. These results revealed that arctigenin has a promising therapeutic effect in ischemic stroke treatment through an anti-inflammatory mechanism.

Laboratory MCAO Test-Bed for Developing Wavefront Sensing Concepts.

PubMed

Goncharov, A V; Dainty, J C; Esposito, S; Puglisi, A

2005-07-11

An experimental optical bench test-bed for developing new wavefront sensing concepts for Multi-Conjugate Adaptive Optics (MCAO) systems is described. The main objective is to resolve imaging problems associated with wavefront sensing of the atmospheric turbulence for future MCAO systems on Extremely Large Telescopes (ELTs). The test-bed incorporates five reference sources, two deformable mirrors (DMs) and atmospheric phase screens to simulate a scaled version of a 10-m adaptive telescope operating at the K band. A recently proposed compact tomographic wavefront sensor is employed for star-oriented DMs control in the MCAO system. The MCAO test-bed is used to verify the feasibility of the wavefront sensing concept utilizing a field lenslet array for multi-pupil imaging on a single detector. First experimental results of MCAO correction with the proposed tomographic wavefront sensor are presented and compared to the theoretical prediction based on the characteristics of the phase screens, actuator density of the DMs and the guide star configuration.

Identification of ischemic regions in a rat model of stroke.

PubMed

Popp, Anke; Jaenisch, Nadine; Witte, Otto W; Frahm, Christiane

2009-01-01

Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.

Identification of Ischemic Regions in a Rat Model of Stroke

PubMed Central

Popp, Anke; Jaenisch, Nadine; Witte, Otto W.; Frahm, Christiane

2009-01-01

Background Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. Methodology/Principal Findings Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. Conclusions/Significance TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study. PMID:19274095

Identification of Proteins Differentially Expressed by Quercetin Treatment in a Middle Cerebral Artery Occlusion Model: A Proteomics Approach.

PubMed

Shah, Fawad-Ali; Park, Dong-Ju; Koh, Phil-Ok

2018-06-20

Cerebral ischemia is a major cause of death and neurological disability. It also leads to severe brain tissue damage by excessive generation of oxidative stress. Quercetin is a bioflavonoid substance that acts an antioxidant agent and exerts a neuroprotective effect against cerebral ischemia. The aim of this study was to detect specific proteins that are differentially expressed in response to quercetin treatment in focal cerebral ischemia. Adult male rats were intraperitoneally injected with vehicle or quercetin (10 mg/kg) 30 min prior to right middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO surgery and right cerebral cortices proteins were identified by two-dimensional gel electrophoresis and mass spectrometry. MCAO leads to neurological behavior disorders, infarction, and histopathological change. However, quercetin treatment alleviated MCAO-induced neuronal deficits and damages. We identified specific proteins differentially expressed between vehicle- and quercetin-treated animals. Among these detected proteins, isocitrate dehydrogenase [NAD + ], adenosylhomocysteinase, pyruvate kinase, and ubiquitin carboxy terminal hydrolase L1 were decreased in vehicle-treated animals, while quercetin administration alleviated the MCAO-induced decreases in these proteins. However, 60 kDa heat shock protein and collapsin response mediator protein 2 were increased in the vehicle-treated animals, and quercetin treatment attenuated increases in these proteins. The expression changes in these proteins were confirmed by Western blot and reverse transcription-PCR analyses. These proteins are associated with cellular differentiation, metabolism, and oxidative stress related proteins. These results suggest that quercetin reduces ischemic injury by modulating the expression of various proteins in focal cerebral ischemia.

Metabolomics-based mechanisms exploration of Huang-Lian Jie-Du decoction on cerebral ischemia via UPLC-Q-TOF/MS analysis on rat serum.

PubMed

Zhu, Baojie; Cao, Huiting; Sun, Limin; Li, Bo; Guo, Liwei; Duan, Jinao; Zhu, Huaxu; Zhang, Qichun

2018-04-24

Huang-Lian Jie-Du decoction (HLJDD), a traditional formula of Chinese medicine constituted with Rhizoma Coptidis, RadixScutellariae, CortexPhellodendri amurensis and Fructus Gardeniae, exhibits unambiguous therapeutic effect on cerebral ischemia via multi-targets action. Further investigation, however, is still required to explore the relationship between those mechanisms and targets through system approaches. Rats of cerebral ischemia were completed by middle cerebral artery occlusion (MCAO) with reperfusion. Following evaluation of pharmacological actions of HLJDD on MCAO rats, the plasma samples from rats of control, MCAO and HLJDD-treated MCAO groups were prepared strictly and subjected to ultra-performance liquid chromatography quadrupole time of flight mass spectrometry for metabolites analysis. The raw mass data were imported to MassLynx software for peak detection and alignment, and further introduced to EZinfo 2.0 software for orthogonal projection to latent structures analysis, principal component analysis and partial least-squares-discriminant analysis. The metabolic pathways assay of those potential biomarkers were performed with MetaboAnalyst through the online database, HMDB, Metlin, KEGG and SMPD. Those intriguing metabolic pathways were further investigated via biochemical assay. HLJDD ameliorated the MCAO-induce cerebral damage and blocked the severe inflammation response. There were nineteen different biomarkers identified among control, MCAO and HLJDD-treated MCAO groups. Ten metabolic pathways were proposed from these significant metabolites. Incorporation with the biochemical assay of cerebral tissue, modulation of metabolic stress, regulation glutamate/GABA-glutamine cycle and enhancement of cholinergic neurons function were explored that involved in the actions of HLJDD on cerebral ischemia. HLJDD achieves therapeutic action on cerebral ischemia via coordinating the basic pathophysiological network of metabolic stress, glutamate metabolism

Ovarian blood vessel occlusion as a surgical sterilization method in rats.

PubMed

Murakami, Eduardo; Sartori de Camargo, Laíza; Freitas Cardoso, Karym Christine de; Miguel, Marina Pacheco; Tavares, Denise Cláudia; Santos Honsho, Cristiane dos; Ferreira de Souza, Fabiana

2014-04-01

To evaluate the female sterilization by occlusion of the ovarian blood flow, using the rat as experimental model. Fifty-five females rats were divided into four groups: I (n=10), bilateral ovariectomy, euthanized at 60 or 90 days; II (n=5), opening the abdominal cavity, euthanized at 90 days; III (n=20), bilateral occlusion of the ovarian blood supply using titanium clips, euthanized at 60 or 90 days; and IV (n=20), bilateral occlusion of the ovarian blood supply using nylon thread, euthanized at 60 or 90 days. The estrous cycle was monitored by vaginal cytology. After euthanasia, the reproductive tissues were evaluated histologically. Ovarian atresia was identified macroscopically at 60 days after surgery in the rats in groups III and IV; however, most of the rats in group III maintained cyclicity. Histology of the tissues from group IV revealed that the ovarian tissue was replaced by dense fibrous connective tissue that was slightly vascularized and that intact follicles were absent by 90 days. Ovarian blood vessels occluded caused ischemia, leading to progressive tissue necrosis, and bilateral occlusion using a nylon ligature is a viable method for surgical sterilization.

Curcumin by down-regulating NF-kB and elevating Nrf2, reduces brain edema and neurological dysfunction after cerebral I/R.

PubMed

Li, Wei; Suwanwela, Nijasri C; Patumraj, Suthiluk

2016-07-01

Oxidation, inflammation, and apoptosis are three critical factors for the pathogenic mechanism of cerebral ischemia/reperfusion (I/R) injury. Curcumin exhibits substantial biological properties via anti-oxidation, anti-inflammation and anti-apoptotic effects; however, the molecular mechanism underlying the effects of curcumin against cerebral I/R injury remains unclear. To investigate the effects of curcumin on cerebral I/R injury associated with water content, infarction volume, and the expression of nuclear factor-kappa-B (NF-κB) and nuclear factor-erythroid-related factor-2 (Nrf2). Middle cerebral artery occlusion (MCAO, 1-hour occlusion and 24-hour reperfusion) was performed in male Wistar rats (n=64) as a cerebral I/R injury model. In the MCAO+CUR group, the rats were administered curcumin (300mg/kg BW, i.p.) at 30min after occlusion. The same surgical procedures were performed in SHAM rats without MCAO occlusion. At 24h post-operation, the parameters, including neurological deficit scores, blood brain barrier (BBB) disruption, water content, and infarction volume, were determined. Brain tissue NF-κB and Nrf2 expression levels were assayed through immunohistochemistry. Compared with the SHAM group, BBB disruption, neurological deficit, and increased brain water content and infarction volume were markedly demonstrated in the MCAO group. NF-κB expression was enhanced in the MCAO group. However, in the MCAO+CUR group, the upregulation of Nrf2, an anti-oxidation related protein, was consistent with a significant decline in the water content, infarction volume, and NF-κB expression. The protective effects of curcumin against cerebral I/R injury reflect anti-oxidation, anti-inflammation and anti-apoptotic activities, resulting in the elevation of Nrf2 and down-regulation of NF-κB. Copyright © 2015 Elsevier Inc. All rights reserved.

Activation of the PI3K-Akt pathway promotes neuroprotection of the δ-opioid receptor agonist against cerebral ischemia-reperfusion injury in rat models.

PubMed

Lv, Mei-Rong; Li, Bin; Wang, Ming-Guang; Meng, Fan-Guo; Yu, Jian-Jun; Guo, Feng; Li, Ye

2017-09-01

The central objective was to identify the role of the PI3K-Akt activation pathway on the neuroprotection of δ-opioid receptor agonist (DADLE) against cerebral ischemia-reperfusion (I/R) injury in a rat model. Fifty-five male Sprague-Dawley (SD) rats were included to establish a middle cerebral artery occlusion (MCAO) model which were then divided into the sham, MCAO, LY294002 (MCAO+DADLE+LY294002 [inhibitor of PI3K-Akt pathway]), DADLE (MCAO+DADLE) and DMSO (MCAO+DADLE+DMSO [dimethyl sulphoxide]) groups. The cerebral infarction (CI) volume and nerve cell apoptosis was determined using TTC and TUNEL staining. Quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and immunohistochemistry staining were applied for the expressions of Bad, Bax, Bcl-2 and cleaved caspase-3. The MCAO group showed higher CI volume, nerve cell apoptosis and cleaved caspase-3 expressions than the DADLE and DMSO groups, which were also higher in the LY294002 group than the DADLE group. Compared with the MCAO group, the mRNA and protein expressions of PI3K and Bcl-2, and the protein expressions of p-Akt and p-Bad were elevated, while the mRNA and protein expressions of Bax were decreased in the DADLE and DMSO groups. Decreased mRNA and protein expressions of PI3K and Bcl-2, reduced protein expressions of p-Akt and p-Bad and elevated mRNA and protein expressions of Bax exhibited in the LY294002 group than the DADLE group. These results indicate that activation of PI3K-Akt pathway promotes the neuroprotection of DADLE against cerebral I/R injury in a rat model by decreasing nerve cells apoptosis. Copyright © 2017. Published by Elsevier Masson SAS.

Protective effect of zinc against ischemic neuronal injury in a middle cerebral artery occlusion model.

PubMed

Kitamura, Youji; Iida, Yasuhiko; Abe, Jun; Ueda, Masashi; Mifune, Masaki; Kasuya, Fumiyo; Ohta, Masayuki; Igarashi, Kazuo; Saito, Yutaka; Saji, Hideo

2006-02-01

In this study, we investigated the effect of vesicular zinc on ischemic neuronal injury. In cultured neurons, addition of a low concentration (under 100 microM) of zinc inhibited both glutamate-induced calcium influx and neuronal death. In contrast, a higher concentration (over 150 microM) of zinc decreased neuronal viability, although calcium influx was inhibited. These results indicate that zinc exhibits biphasic effects depending on its concentration. Furthermore, in cultured neurons, co-addition of glutamate and CaEDTA, which binds extra-cellular zinc, increased glutamate-induced calcium influx and aggravated the neurotoxicity of glutamate. In a rat transient middle cerebral artery occlusion (MCAO) model, the infarction volume, which is related to the neurotoxicity of glutamate, increased rapidly on the intracerebral ventricular injection of CaEDTA 30 min prior to occlusion. These results suggest that zinc released from synaptic vesicles may provide a protective effect against ischemic neuronal injury.

Rapamycin ameliorates brain metabolites alterations after transient focal ischemia in rats.

PubMed

Chauhan, Anjali; Sharma, Uma; Jagannathan, Naranamangalam R; Gupta, Yogendra Kumar

2015-06-15

Rapamycin has been shown to protect against middle cerebral artery occlusion (MCAo) induced ischemic injury. In this study, the neuroprotective effect of rapamycin on the metabolic changes induced by MCAo was evaluated using nuclear magnetic resonance (NMR) spectroscopy of brain tissues. MCAo in rats was induced by insertion of nylon filament. One hour after ischemia, rapamycin (250 µg/kg, i.p.) in dimethyl sulfoxide was administered. Reperfusion was done 2h after ischemia. Twenty-four hours after ischemia phospholipase A2 (PLA2) levels and metabolic changes were assessed. Perchloric acid extraction was performed on the brain of all animals (n=7; sham, vehicle; DMSO and rapamycin 250 µg/kg) and the various brain metabolites were assessed by NMR spectroscopy. In all 44 metabolites were assigned in the proton NMR spectrum of rat brain tissues. In the vehicle group, we observed increased lactate levels and decreased levels of glutamate/glutamine, choline containing compounds, creatine/phosphocreatine (Cr/PCr), taurine, myo-inositol, γ-amino butryic acid (GABA), N-aspartyl aspartate (NAA), purine and pyrimidine metabolites. In rapamycin treated rats, there was increase in the levels of choline containing compounds, NAA, myo-inositol, glutamate/glutamine, GABA, Cr/PCr and taurine as compared to those of vehicle control (P<0.05). Rapamycin treatment reduced PLA2 levels as compared to vehicle group (P<0.05). Our findings indicated that rapamycin reduced the increased PLA2 levels and altered brain metabolites after MCAo. These protective effects might be attributed to its effect on cell membrane metabolism; glutamate induced toxicity and calcium homeostasis in stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification of proteins regulated by ferulic acid in a middle cerebral artery occlusion animal model-a proteomics approach.

PubMed

Sung, Jin-Hee; Cho, Eun-Hae; Cho, Jae-Hyeon; Won, Chung-Kil; Kim, Myeong-Ok; Koh, Phil-Ok

2012-11-01

Ferulic acid plays a neuroprotective role in cerebral ischemia. The aim of this study was to identify the proteins that are differentially expressed following ferulic acid treatment during ischemic brain injury using a proteomics technique. Middle cerebral artery occlusion (MCAO) was performed to induce a focal cerebral ischemic injury in adult male rats, and ferulic acid (100 mg/kg) or vehicle was administered immediately after MCAO. Brain tissues were collected 24 hr after MCAO. The proteins in the cerebral cortex were separated using two-dimensional gel electrophoresis and were identified by mass spectrometry. We detected differentially expressed proteins between vehicle- and ferulic acid-treated animals. Adenosylhomocysteinase, isocitrate dehydrogenase [NAD(+)], mitogen-activated protein kinase kinase 1 and glyceraldehyde-3-phosphate dehydrogenase were decreased in the vehicle-treated group, and ferulic acid prevented the injury-induced decreases in these proteins. However, pyridoxal phosphate phosphatase and heat shock protein 60 were increased in the vehicle-treated group, while ferulic acid prevented the injury-induced increase in these proteins. It is accepted that these enzymes are involved in cellular metabolism and differentiation. Thus, these findings suggest evidence that ferulic acid plays a neuroprotective role against focal cerebral ischemia through the up- and down-modulation of specific enzymes.

Blood-Spinal Cord Barrier Alterations in Subacute and Chronic Stages of a Rat Model of Focal Cerebral Ischemia

PubMed Central

Haller, Edward; Tajiri, Naoki; Thomson, Avery; Barretta, Jennifer; Williams, Stephanie N.; Haim, Eithan D.; Qin, Hua; Frisina-Deyo, Aric; Abraham, Jerry V.; Sanberg, Paul R.; Van Loveren, Harry; Borlongan, Cesario V.

2016-01-01

We previously demonstrated blood-brain barrier impairment in remote contralateral brain areas in rats at 7 and 30 days after transient middle cerebral artery occlusion (tMCAO), indicating ischemic diaschisis. Here, we focused on effects of subacute and chronic focal cerebral ischemia on the blood-spinal cord barrier (BSCB). We observed BSCB damage on both sides of the cervical spinal cord in rats at 7 and 30 days post-tMCAO. Major BSCB ultrastructural changes in spinal cord gray and white matter included vacuolated endothelial cells containing autophagosomes, pericyte degeneration with enlarged mitochondria, astrocyte end-feet degeneration and perivascular edema; damaged motor neurons, swollen axons with unraveled myelin in ascending and descending tracts and astrogliosis were also observed. Evans Blue dye extravasation was maximal at 7 days. There was immunofluorescence evidence of reduction of microvascular expression of tight junction occludin, upregulation of Beclin-1 and LC3B immunoreactivities at 7 days and a reduction of the latter at 30 days post-ischemia. These novel pathological alterations on the cervical spinal cord microvasculature in rats after tMCAO suggest pervasive and long-lasting BSCB damage after focal cerebral ischemia, and that spinal cord ischemic diaschisis should be considered in the pathophysiology and therapeutic approaches in patients with ischemic cerebral infarction. PMID:27283328

Traditional Mongolian medicine Eerdun Wurile improves stroke recovery through regulation of gene expression in rat brain.

PubMed

Gaowa, Saren; Bao, Narisi; Da, Man; Qiburi, Qiburi; Ganbold, Tsogzolmaa; Chen, Lu; Altangerel, Altanzul; Temuqile, Temuqile; Baigude, Huricha

2018-05-16

Eerdun Wurile (EW) is one of the key Mongolian medicines for treatment of neurological and cardiological disorders. EW is ranked most regularly used Mongolian medicine in clinic. Components of EW which mainly originate from natural products are well defined and are unique to Mongolian medicine. Although the recipe of EW contains known neuroactive chemicals originated from plants, its mechanism of action has never been elucidated at molecular level. The objective of the present study is to explore the mechanism of neuroregenerative activity of EW by focusing on the regulation of gene expression in the brain of rat model of stroke. Rat middle cerebral artery occlusion (MCAO) models were treated with EW for 15 days. Then, total RNAs from the cerebral cortex of rat MCAO models treated with either EW or control (saline) were extracted and analyzed by transcriptome sequencing. Differentially expressed genes were analyzed for their functions during the recovery of ischemic stroke. The expression level of significantly differentially expressed genes such as growth factors, microglia markers and secretive enzymes in the lesion was further validated by RT-qPCR and immunohistochemistry. Previously identified neuroactive compounds, such as geniposide (Yu et al., 2009), myristicin (Shin et al., 1988), costunolide (Okugawa et al., 1996), toosendanin (Shi and Chen, 1999) were detected in EW formulation. Bederson scale indicated that the treatment of rat MCAO models with EW showed significantly lowered neurological deficits (p < 0.01). The regional cerebral blood circulation was also remarkably higher in rat MCAO models treated with EW compared to the control group. A total of 186 genes were upregulated in the lesion of rat MCAO models treated with EW compared to control group. Among them, growth factors such as Igf1 (p < 0.05), Igf2 (p < 0.01), Grn (p < 0.01) were significantly upregulated in brain after treatment of rat MCAO models with EW. Meanwhile, greatly

Neurogenesis and angiogenesis within the ipsilateral thalamus with secondary damage after focal cortical infarction in hypertensive rats.

PubMed

Ling, Li; Zeng, Jinsheng; Pei, Zhong; Cheung, Raymond T F; Hou, Qinghua; Xing, Shihui; Zhang, Suping

2009-09-01

Neurogenesis and angiogenesis in the subventricular zone and peri-infarct region have been confirmed. However, newly formed neuronal cells and blood vessels that appear in the nonischemic ipsilateral ventroposterior nucleus (VPN) of the thalamus with secondary damage after stroke has not been previously studied. Twenty-four stroke-prone renovascular hypertensive rats were subjected to distal right middle cerebral artery occlusion (MCAO) or sham operation. 5'-Bromo-2'-deoxyuridine (BrdU) was used to label cell proliferation. Rats were killed at 7 or 14 days after the operation. Neuronal nuclei (NeuN), OX-42, BrdU, nestin, laminin(+), BrdU(+)/nestin(+), BrdU(+)/NeuN(+), nestin(+)/GFAP(+)(glial fibrillary acidic protein), and BrdU(+)/laminin(+) immunoreactive cells were detected within the ipsilateral VPN. The primary infarction was confined to the right somatosensory cortex. Within the ipsilateral VPN of the ischemic rats, the number of NeuN(+) neurons decreased, the OX-42(+) microglia cells were activated, and BrdU(+) and nestin(+) cells were detected at day 7 after MCAO and increased in number at day 14. Moreover, BrdU(+)/nestin(+) cells and BrdU(+)/NeuN(+) cells were detected at day 14 after MCAO. In addition, the ischemic rats showed a significant increase in vascular density in the ipsilateral VPN compared with the sham-operated rats. These results suggest that secondary damage with neurogenesis and angiogenesis of the ipsilateral VPN of the thalamus occurs after focal cortical infarction.

Long-lasting neuroprotection and neurological improvement in stroke models with new, potent and brain permeable inhibitors of poly(ADP-ribose) polymerase

PubMed Central

Moroni, F; Cozzi, A; Chiarugi, A; Formentini, L; Camaioni, E; Pellegrini-Giampietro, DE; Chen, Y; Liang, S; Zaleska, MM; Gonzales, C; Wood, A; Pellicciari, R

2012-01-01

BACKGROUND AND PURPOSES Thienyl-isoquinolone (TIQ-A) is a relatively potent PARP inhibitor able to reduce post-ischaemic neuronal death in vitro. Here we have studied, in different stroke models in vivo, the neuroprotective properties of DAMTIQ and HYDAMTIQ, two TIQ-A derivatives able to reach the brain and to inhibit PARP-1 and PARP-2. EXPERIMENTAL APPROACH Studies were carried out in (i) transient (2 h) middle cerebral artery occlusion (tMCAO), (ii) permanent MCAO (pMCAO) and (iii) electrocoagulation of the distal portion of MCA in conjunction with transient (90 min) bilateral carotid occlusion (focal cortical ischaemia). KEY RESULTS In male rats with tMCAO, HYDAMTIQ (0.1–10 mg·kg−1) injected i.p. three times, starting 4 h after MCAO, reduced infarct volumes by up to 70%, reduced the loss of body weight by up to 60% and attenuated the neurological impairment by up to 40%. In age-matched female rats, HYDAMTIQ also reduced brain damage. Protection, however, was less pronounced than in the male rats. In animals with pMCAO, HYDAMTIQ administered 30 min after MCAO reduced infarct volumes by approximately 40%. In animals with focal cortical ischaemia, HYDAMTIQ treatment decreased post-ischaemic accumulation of PAR (the product of PARP activity) and the presence of OX42-positive inflammatory cells in the ischaemic cortex. It also reduced sensorimotor deficits for up to 90 days after MCAO. CONCLUSION AND IMPLICATIONS Our results show that HYDAMTIQ is a potent PARP inhibitor that conferred robust neuroprotection and long-lasting improvement of post-stroke neurological deficits. PMID:21913897

Progesterone Treatment in Two Rat Models of Ocular Ischemia

PubMed Central

Allen, Rachael S.; Olsen, Timothy W.; Sayeed, Iqbal; Cale, Heather A.; Morrison, Katherine C.; Oumarbaeva, Yuliya; Lucaciu, Irina; Boatright, Jeffrey H.; Pardue, Machelle T.; Stein, Donald G.

2015-01-01

Purpose. To determine whether the neurosteroid progesterone, shown to have protective effects in animal models of traumatic brain injury, stroke, and spinal cord injury, is also protective in ocular ischemia animal models. Methods. Progesterone treatment was tested in two ocular ischemia models in rats: a rodent anterior ischemic optic neuropathy (rAION) model, which induces permanent monocular optic nerve stroke, and the middle cerebral artery occlusion (MCAO) model, which causes transient ischemia in both the retina and brain due to an intraluminal filament that blocks the ophthalmic and middle cerebral arteries. Visual function and retinal histology were assessed to determine whether progesterone attenuated retinal injury in these models. Additionally, behavioral testing and 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining in brains were used to compare progesterone's neuroprotective effects in both retina and brain using the MCAO model. Results. Progesterone treatment showed no effect on visual evoked potential (VEP) reduction and retinal ganglion cell loss in the permanent rAION model. In the transient MCAO model, progesterone treatment reduced (1) electroretinogram (ERG) deficits, (2) MCAO-induced upregulation of glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP), and (3) retinal ganglion cell loss. As expected, progesterone treatment also had significant protective effects in behavioral tests and a reduction in infarct size in the brain. Conclusions. Progesterone treatment showed protective effects in the retina following MCAO but not rAION injury, which may result from mechanistic differences with injury type and the therapeutic action of progesterone. PMID:26024074

Progesterone induces neuroprotection following reperfusion-promoted mitochondrial dysfunction after focal cerebral ischemia in rats.

PubMed

Andrabi, Syed Suhail; Parvez, Suhel; Tabassum, Heena

2017-06-01

Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has

Nogo-A is involved in secondary axonal degeneration of thalamus in hypertensive rats with focal cortical infarction.

PubMed

Wang, Fang; Liang, Zhijian; Hou, Qinghua; Xing, Shihui; Ling, Li; He, Meixia; Pei, Zhong; Zeng, Jinsheng

2007-05-07

We investigate whether Nogo-A is involved in the secondary axonal degeneration in the thalamus after distal middle cerebral artery occlusion (MCAO) in stroke-prone renovascular hypertensive rats (RHRSP). The expression of Nogo-A in ipsilateral ventroposterior nucleus (VPN) of the thalamus in RHRSP was observed at 1, 2 and 4 weeks after distal MCAO. In addition, intracerebroventricular infusion of NEP1-40, a Nogo-66 receptor (NgR) antagonist peptide, was administered starting 24 h after MCAO and continued for 1, 2 and 4 weeks, respectively. Axonal damage and regeneration were evaluated by analysis of the immunoreactivity (IR) of amyloid betaA4 precursor protein (APP), growth associated protein 43 (GAP-43) and microtubule associated protein 2 (MAP-2) in ipsilateral VPN of the thalamus at 1, 2 and 4 weeks after distal MCAO. Following ischemia, the expression of Nogo-A in oligodendrocytes increased persistently and its localization became redistributed around damaged axons and dendrites. Administration of NEP1-40 downregulated the expression of Nogo-A, reduced axonal injury and enhanced axonal regeneration. Our data suggest that Nogo-A is involved in secondary axonal degeneration and that inhibition of Nogo-A can reduce neuronal damage in the thalamus after distal MCAO.

[Study of neuron-protective effect and mechanism of neuregulin1β against cerebral ischemia reperfusion-induced injury in rats].

PubMed

Ji, Y Q; Zhang, R; Teng, L; Li, H Y; Guo, Y L

2017-07-18

Objective: Thecurrent study is to explore the neuron-protective mechanism of neuregulin1β (NRG1β) in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) through inhibiting the c-Jun phosphorylation. Methods: After 24 h of MCAO/R (referring to Longa's method), neurobehavioral function was measured by modified neurological severity score (mNSS) test; the cerebral infarction volume was detected by triphenyltetrazolium chloride (TTC) staining; the blood brain barrier (BBB) permeability was measured by Evans Blue (EB); the neuron morphology of brain tissue was observed by Nissl stain; the ultra-structures of the neurons were observed by transmission electron microscopy (TEM); the apoptotic neurons were counted by in situ cell death detection kit colocalized with NeuN; the expressions of phospho-c-Jun was determined by immunofluorescent labeling and Western blot analysis. Results: Compared with the sham-operation rats, the rats receiving MCAO/R showed increased mNSS (9.7±1.2), cerebral infarction volume (41.4±3.0)%, permeability of BBB, deformation of neurons, ischemia-induced apoptosis (0.63±0.04), and enhanced expression of phospho-c-Jun protein (0.90±0.07) (all P <0.05). Our data indicated that NRG1β attenuated neurologic deficits (6.4±0.9), decreased the cerebral infarction volume (10.4±0.5), reduced EB extravasation (1.55±0.13) and the deformation of neurons, protected the ultra-structure of neurons, blocked ischemia-induced apoptosis (0.23±0.02), through down-regulated phospho-c-Jun expression (0.40±0.03) in MCAO/R rats ( P <0.05). Conclusion: NRG1β exerts neuron-protective effects against ischemia reperfusion-induced injury in rats through inhibiting the c-Jun phosphorylation.

Effect of ligustrazine on levels of amino acid neurotransmitters in rat striatum after cerebral ischemia-reperfusion injury.

PubMed

Han, Jin; Wan, Hai-Tong; Yang, Jie-Hong; Zhang, Yu-Yan; Ge, Li-Jun; Bie, Xiao-Dong

2014-01-01

This study aimed to evaluate the effect of ligustrazine on levels of amino acid transmitters in the extracellular fluid of striatum following cerebral ischemia/reperfusion (I/R) in male Sprague-Dawley rats. A microdialysis cannula guide was implanted into the right striatum. After recovery, animals underwent a sham operation or middle cerebral artery occlusion (MCAO). Those that developed cerebral ischemia after MCAO were randomized to receive propylene glycol salt water and ligustrazine respectively. Striatal fluid samples were collected from all animals at 15-min intervals after treatment and were subjected to HPLC analysis of aspartic acid, glutamic acid, taurine, and γ-amino butyric acid. Upon the last sample collection, animals were sacrificed and brain tissue specimens were collected for triphenyltetrazolium chloride staining and NeuN staining. Compared with the sham operation, MCAO induced significant neurological deficits and increased striatal concentrations of the four neurotransmitters assessed in a time-dependent manner (P < 0.01). Ligustrazine effectively attenuated the detrimental effects of MCAO on the brain. These observations suggest that ligustrazine as a novel cerebral infarction-protective agent may have potential clinical implications for I/R-related brain damage.

Resting-state Functional Magnetic Resonance Imaging Analysis of Brain Functional Activity in Rats with Ischemic Stroke Treated by Electro-acupuncture.

PubMed

Liang, Shengxiang; Lin, Yunjiao; Lin, Bingbing; Li, Jianhong; Liu, Weilin; Chen, Lidian; Zhao, Shujun; Tao, Jing

2017-09-01

To evaluate whether electro-acupuncture (EA) treatment at acupoints of Zusanli (ST 36) and Quchi (LI 11) could reduce motor impairments and enhance brain functional recovery in rats with ischemic stroke. A rat model of middle cerebral artery occlusion (MCAO) was established. EA at ST 36 and LI 11was started at 24 hours (MCAO + EA group) after ischemic stroke. The nontreatment (MCAO) and sham-operated control (SC) groups were included as controls. The neurologic deficits of all groups were assessed by Zea Longa scores and the modified neurologic severity scores on 24 hours and 8 days after MCAO. To further investigate the effect of EA on infract volume and brain function, magnetic resonance imaging was used to estimate the brain lesion and brain neural activities of each group at 8 days after ischemic stroke. Within 1 week after EA treatment, the neurologic deficits were significantly alleviated, and the cerebral infarctions were improved, including visual cortex, motor cortex, striatum, dorsal thalamus, and hippocampus. Furthermore, whole brain neural activities of auditory cortex, lateral nucleus group of dorsal thalamus, hippocampus, motor cortex, orbital cortex, sensory cortex, and striatum were decreased in MCAO group, whereas that of brain neural activities were increased after EA treatment, suggesting these brain regions are in accordance with the brain structure analysis. EA at ST 36 and LI 11 could enhance the neural activity of motor function-related brain regions, including motor cortex, dorsal thalamus, and striatum in rats, which is a potential treatment for ischemia stroke. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Preconditioning with the traditional Chinese medicine Huang-Lian-Jie-Du-Tang initiates HIF-1α-dependent neuroprotection against cerebral ischemia in rats.

PubMed

Zhang, Qichun; Bian, Huimin; Li, Yu; Guo, Liwei; Tang, Yuping; Zhu, Huaxu

2014-06-11

Huang-Lian-Jie-Du-Tang (HLJDT) is a classical heat-clearing and detoxicating formula of traditional Chinese medicine that is widely used to treat stroke. The present study was designed to investigate the effects of HLJDT preconditioning on neurons under oxygen and glucose deprivation (OGD) and rats subjected to middle cerebral artery occlusion (MCAO). A stroke model of rats was obtained through MCAO. Following HLJDT preconditioning, the cerebral infarction volume, cerebral water content, and neurological deficient score were determined. Cerebral cortical neurons cultured in vitro were preconditioned with HLJDT and then subjected to OGD treatment. The release of lactate dehydrogenase (LDH) from neurons was detected. The levels of hypoxia-inducible factor-1α (HIF-1α) and PI3K/Akt signaling were analyzed by western blotting, and the levels of erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in the supernatant of the neurons and the plasma of MCAO rats were measured through a radioimmunological assay. The apoptosis and proliferation of neurons were analyzed by immunohistochemistry. HLJDT preconditioning significantly reduced the cerebral infarction volume and cerebral water content and ameliorated the neurological deficient score of MCAO rats. In addition, HLJDT preconditioning protected neurons against OGD. Increased HIF-1α, EPO, and VEGF levels and the activation of PI3K/Akt signaling were observed as a result of HLJDT preconditioning. Furthermore, HLJDT preconditioning was found to inhibit ischemia-induced neuron apoptosis and to promote neuron proliferation under conditions of ischemia/reperfusion. Both rats and neurons subjected to HLJDT preconditioning were able to resist ischemia/reperfusion or hypoxia injury through the inhibition of apoptosis and the enhancement of proliferation, and these effects were primarily dependent on the activation of the PI3K/Akt signaling pathway and HIF-1α. Copyright © 2014 Elsevier Ireland Ltd. All rights

Neuroprotective effects of Danggui-Jakyak-San on rat stroke model through antioxidant/antiapoptotic pathway.

PubMed

Kim, Sang-Ho; Chung, Dae-Kyoo; Lee, Young Joon; Song, Chang-Hyun; Ku, Sae-Kwang

2016-07-21

Dangui-Jakyak-San (DJ) is a traditional Korean medicinal polyherb, prescribed typically in patients with insufficient blood supply in Eastern Asia. The DJ also has been reported to have neuroprotective effects in vitro and in vivo studies. The therapeutic potential of DJ was examined in stroke rat model, in comparison with donepezil, a reversible acetylcholinesterase inhibitor. Ischemic stroke rat model was induced by surgery of permanent occlusion of middle cerebral artery (pMCAO). The model was orally administered with distilled water (pMCAO control), donepezil at 10mg/kg (Donepezil) and DJ at 200, 100 and 50mg/kg (DJ 200, DJ 100 and DJ 50, respectively). Sham had the same surgery excepting for the pMCAO, and it was administered with distilled water (sham control). After the administration for 28 days, the groups of DJ exhibited dose-dependent reduction in infarct/defect volumes with improvement in sensorimotor and cognitive motor function, comparing to pMCAO control. The DJ treatments seemed to enhance antiapoptotic and antioxidant effects; increases in antiapoptotic expressions (STAT3 and Pim-1) and decreases in lipid peroxidation (MDA) together with increases in contents of endogenous antioxidant (GSH) and activities of antioxidant enzymes (catalase and SOD). The histopathological analyses revealed significant reduction in neuronal apoptosis (caspase-3 and PARP) and neuronal degradation with atrophy and degeneration, in the DJ treatments. Furthermore, the oxidative stresses (nitrotyrosine as an iNOS factor and 4-HNE as a marker of lipid peroxidation) were observed mild. Although the similar neuroprotective effects were observed, the body weight loss was scarcely alleviated in Donepezil comparing to pMCAO control. These suggest that DJ ameliorate the neurological dysfunction of cerebral ischemia through augmentation of antioxidant defense system and up-regulation of STAT3 and Pim-1. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

TDAG8 activation attenuates cerebral ischaemia-reperfusion injury via Akt signalling in rats.

PubMed

Ma, X D; Hang, L H; Shao, D H; Shu, W W; Hu, X L; Luo, H

2017-07-01

T-cell death-associated gene 8 (TDAG8), a member of the proton-sensitive G-protein-coupled receptor (GPCR) class with an immune-specific expression profile, was recently shown to be expressed in the rat brain; however, its role in ischaemic stroke remains unknown. We initially confirmed the time-dependent expression of TDAG8 in rat brain tissue after ischaemic stroke and reperfusion. Further evaluations were performed to increase TDAG8 expression 6h prior to middle cerebral artery occlusion (MCAO) by injecting a specific agonist, BTB09089, into the lateral ventricle to increase TDAG8 expression. Twenty-four hours before MCAO, a specific small interfering RNA (siRNA) was introduced. The infarction volume, neurological deficit score and cleaved caspase-3 and Bcl-2 expression were used to assess the effects of TDAG8 on ischaemic stroke. Finally, the effects of TDAG8 on the development of primary cortical neurons exposed to oxygen-glucose deprivation (OGD) were investigated. TDAG8 expression increased both in vivo and in vitro. Pretreatment with BTB09089 up-regulated TDAG8 and Bcl-2 expression and down-regulated cleaved caspase-3 expression, while the infarction volume was reduced, and neurological deficits were ameliorated 24 and 72h after MCAO. However, the protective effects of TDAG8 were reversed when its level was reduced in TDAG8-deficient rats. More importantly, these findings are consistent with data from neurons subjected to OGD. TDAG8 plays an important neuroprotective role through inhibition of neuronal apoptosis and alleviation of neurological deficits by activating the Akt signalling pathway in rats. Copyright © 2017 Elsevier Inc. All rights reserved.

A New Approach of Short Wave Protection against Middle Cerebral Artery Occlusion/Reperfusion Injury via Attenuation of Golgi Apparatus Stress by Inhibition of Downregulation of Secretory Pathway Ca(2+)-ATPase Isoform 1 in Rats.

PubMed

Fan, Yongmei; Zhang, Changjie; Li, Ting; Peng, Wenna; Yin, Jing; Li, Xiaofao; Kong, Ying; Lan, Chunna; Wang, Rumi; Hu, Zhiping

2016-07-01

Short wave (SW), a pattern of electromagnetic therapy, achieves an oscillating electromagnetic field. It has been reported that it may have a potential effect on cerebral injury. The present study was designed to investigate the potential role and possible mechanism of SW in focal cerebral ischemia/reperfusion (I/R) injury in rats. Secretory pathway Ca(2+)/Mn(2+) ATPase isoform 1 is a major component of Golgi apparatus stress. It has been reported as representative of Golgi apparatus stress. Up to 120 minutes of middle cerebral artery occlusion (MCAO) and reperfusion injury was induced in male Sprague-Dawley rats. Different sessions of SW daily were administered over head after reperfusion from day 1 to day 7. Functional recovery scores, survival rates, infarct volume analysis, electron microscope test, and western blotting studies were used to analyze the therapy. SW protected against neuronal death and apoptosis in cornu ammon 1 region of hippocampus by reducing neuronal deficit, infarct volume, and ultrastructure. SW partly inhibited upregulation of caspase3. In addition, the expression of secretory pathway Ca(2+)-ATPase isoform 1 (SPCA1) was upregulated by SW. Our data indicate that SW can be protected against focal cerebral I/R injury, and the influence on Golgi apparatus stress might provide us a new perspective in further study. To the authors' knowledge, this is the first report using SW to increase expression of SPCA1 indicating modulate Golgi apparatus stress in MCAO and reperfusion model. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Prevention of Glutamate Accumulation and Upregulation of Phospho-Akt may Account for Neuroprotection Afforded by Bergamot Essential Oil against Brain Injury Induced by Focal Cerebral Ischemia in Rat.

PubMed

Amantea, Diana; Fratto, Vincenza; Maida, Simona; Rotiroti, Domenicantonio; Ragusa, Salvatore; Nappi, Giuseppe; Bagetta, Giacinto; Corasaniti, Maria Tiziana

2009-01-01

The effects of bergamot essential oil (BEO; Citrus bergamia, Risso) on brain damage caused by permanent focal cerebral ischemia in rat were investigated. Administration of BEO (0.1-0.5 ml/kg but not 1 ml/kg, given intraperitoneally 1 h before occlusion of the middle cerebral artery, MCAo) significantly reduced infarct size after 24 h permanent MCAo. The most effective dose (0.5 ml/kg) resulted in a significant reduction of infarct extension throughout the brain, especially in the medial striatum and the motor cortex as revealed by TTC staining of tissue slices. Microdialysis experiments show that BEO (0.5 ml/kg) did not affect basal amino acid levels, whereas it significantly reduced excitatory amino acid, namely aspartate and glutamate, efflux in the frontoparietal cortex typically observed following MCAo. Western blotting experiments demonstrated that these early effects were associated, 24 h after permanent MCAo, to a significant increase in the phosphorylation and activity of the prosurvival kinase, Akt. Indeed, BEO significantly enhanced the phosphorylation of the deleterious downstream kinase, GSK-3beta, whose activity is negatively regulated via phosphorylation by Akt.

Sustained functional improvement by hepatocyte growth factor-like small molecule BB3 after focal cerebral ischemia in rats and mice

PubMed Central

Chaparro, Rafael E; Izutsu, Miwa; Sasaki, Toshihiro; Sheng, Huaxin; Zheng, Yi; Sadeghian, Homa; Qin, Tao; von Bornstadt, Daniel; Herisson, Fanny; Duan, Bin; Li, Jing-Song; Jiang, Kai; Pearlstein, Molly; Pearlstein, Robert D; Smith, David E; Goldberg, Itzhak D; Ayata, Cenk; Warner, David S

2015-01-01

Hepatocyte growth factor (HGF), efficacious in preclinical models of acute central nervous system injury, is burdened by administration of full-length proteins. A multiinstitutional consortium investigated the efficacy of BB3, a small molecule with HGF-like activity that crosses the blood–brain barrier in rodent focal ischemic stroke using Stroke Therapy Academic Industry Roundtable (STAIR) and Good Laboratory Practice guidelines. In rats, BB3, begun 6 hours after temporary middle cerebral artery occlusion (tMCAO) reperfusion, or permanent middle cerebral artery occlusion (pMCAO) onset, and continued for 14 days consistently improved long-term neurologic function independent of sex, age, or laboratory. BB3 had little effect on cerebral infarct size and no effect on blood pressure. BB3 increased HGF receptor c-Met phosphorylation and synaptophysin expression in penumbral tissue consistent with a neurorestorative mechanism from HGF-like activity. In mouse tMCAO, BB3 starting 10 minutes after reperfusion and continued for 14 days improved neurologic function that persisted for 8 weeks in some, but not all measures. Study in animals with comorbidities and those exposed to common stroke drugs are the next steps to complete preclinical assessment. These data, generated in independent, masked, and rigorously controlled settings, are the first to suggest that the HGF pathway can potentially be harnessed by BB3 for neurologic benefit after ischemic stroke. PMID:25712497

Neuronal precursor cell proliferation in the hippocampus after transient cerebral ischemia: a comparative study of two rat strains using stereological tools.

PubMed

Kelsen, Jesper; Larsen, Marianne H; Sørensen, Jens Christian; Møller, Arne; Frøkiaer, Jørgen; Nielsen, Søren; Nyengaard, Jens R; Mikkelsen, Jens D; Rønn, Lars Christian B

2010-04-06

We are currently investigating microglial activation and neuronal precursor cell (NPC) proliferation after transient middle cerebral artery occlusion (tMCAo) in rats. This study aimed: (1) to investigate differences in hippocampal NPC proliferation in outbred male spontaneously hypertensive rats (SHRs) and Sprague-Dawley rats (SDs) one week after tMCAo; (2) to present the practical use of the optical fractionator and 2D nucleator in stereological brain tissue analyses; and (3) to report our experiences with an intraluminal tMCAo model where the occluding filament is advanced 22 mm beyond the carotid bifurcation and the common carotid artery is clamped during tMCAo. Twenty-three SDs and twenty SHRs were randomized into four groups subjected to 90 minutes tMCAo or sham. BrdU (50 mg/kg) was administered intraperitoneally twice daily on Day 4 to 7 after surgery. On Day 8 all animals were euthanized. NeuN-stained tissue sections were used for brain and infarct volume estimation with the 2D nucleator and Cavalieri principle. Brains were studied for the presence of activated microglia (ED-1) and hippocampal BrdU incorporation using the optical fractionator. We found no significant difference or increase in post-ischemic NPC proliferation between the two strains. However, the response to remote ischemia may differ between SDs and SHRs. In three animals increased post-stroke NPC proliferation was associated with hippocampal ischemic injury. The mean infarct volume was 89.2 +/- 76.1 mm3 in SHRs and 16.9 +/- 22.7 mm3 in SDs (p < 0.005). Eight out of eleven SHRs had ischemic neocortical damage in contrast to only one out of 12 SDs. We observed involvement of the anterior choroidal and hypothalamic arteries in several animals from both strains and the anterior cerebral artery in two SHRs. We found no evidence of an early hippocampal NPC proliferation one week after tMCAo in both strains. Infarction within the anterior choroidal artery could induce hippocampal ischemia and

TRANSCUTANEOUS CERVICAL VAGUS NERVE STIMULATION AMELIORATES ACUTE ISCHEMIC INJURY IN RATS

PubMed Central

Ay, Ilknur; Nasser, Rena; Simon, Bruce; Ay, Hakan

2016-01-01

Background Direct stimulation of the vagus nerve in the neck via surgically implanted electrodes is protective in animal models of stroke. We sought to determine the safety and efficacy of a non-invasive cervical VNS (nVNS) method using surface electrodes applied to the skin overlying the vagus nerve in the neck in a model of middle cerebral artery occlusion (MCAO). Methods nVNS was initiated variable times after MCAO hour in rats (n=33). Control animals received sham stimulation (n=33). Infarct volume and functional outcome were assessed on day 7. Brains were processed by immunohistochemistry for microglial activation and cytokine levels. The ability of nVNS to activate the nucleus tractus solitarius (NTS) was assessed using c-Fos immunohistochemistry. Results Infarct volume was 43.15±3.36 percent of the contralateral hemisphere (PCH) in control and 28.75±4.22 PCH in nVNS-treated animals (p<0.05). The effect of nVNS on infarct size was consistent when stimulation was initiated up to 4 hours after MCAO. There was no difference in heart rate and blood pressure between control and nVNS-treated animals. The number of c-Fos positive cells was 32.4±10.6 and 6.2±6.3 in the ipsilateral NTS (p<0.05) and 30.4±11.2 and 5.8±4.3 in the contralateral NTS (p<0.05) in nVNS-treated and control animals, respectively. nVNS reduced the number of Iba-1, CD68, and TNF-α positive cells and increased the number of HMGB1 positive cells. Conclusions nVNS inhibits ischemia-induced immune activation and reduces the extent of tissue injury and functional deficit in rats without causing cardiac or hemodynamic adverse effects when initiated up to 4 hours after MCAO. PMID:26723020

Neuroprotection of the leaf and stem of Vitis amurensis and their active compounds against ischemic brain damage in rats and excitotoxicity in cultured neurons.

PubMed

Kim, Joo Youn; Jeong, Ha Yeon; Lee, Hong Kyu; Kim, SeungHwan; Hwang, Bang Yeon; Bae, KiHwan; Seong, Yeon Hee

2012-01-15

Vitis amurensis (Vitaceae) has been reported to have anti-oxidant and anti-inflammatory activities. The present study investigated a methanol extract from the leaf and stem of V. amurensis for neuroprotective effects on cerebral ischemic damage in rats and on excitotoxicity induced by glutamate in cultured rat cortical neurons. Transient focal cerebral ischemia was induced by 2h middle cerebral artery occlusion followed by 24h reperfusion (MCAO/reperfusion) in rats. Orally administered V. amurensis (25-100 mg/kg) reduced MCAO/reperfusion-induced infarct and edema formation, neurological deficits, and neuronal death. Depletion of glutathione (GSH) level and lipid peroxidation induced by MCAO/reperfusion was inhibited by administration of V. amurensis. The increase of phosphorylated mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2), and pro-apoptotic proteins and the decrease of anti-apoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with V. amurensis. Exposure of cultured cortical neurons to 500 μM glutamate for 12h induced neuronal cell death. V. amurensis (1-50 μg/ml) and (+)-ampelopsin A, γ-2-viniferin, and trans-ε-viniferin isolated from the leaf and stem of V. amurensis inhibited glutamate-induced neuronal death, the elevation of intracellular calcium ([Ca(2+)](i)), the generation of reactive oxygen species (ROS), and changes of apoptosis-related proteins in cultured cortical neurons, suggesting that the neuroprotective effect of V. amurensis may be partially attributed to these compounds. These results suggest that the neuroprotective effect of V. amurensis against focal cerebral ischemic injury might be due to its anti-apoptotic effect, resulting from anti-excitotoxic, anti-oxidative, and anti-inflammatory effects and that the leaf and stem of V. amurensis have possible therapeutic roles for preventing neurodegeneration in stroke. Copyright © 2011 Elsevier GmbH. All rights reserved.

Protective Effect of Ad-VEGF-Bone Mesenchymal Stem Cells on Cerebral Infarction.

PubMed

Chen, Bo; Zhang, Feng; Li, Qiao-Yu; Gong, Aihua; Lan, Qing

2016-01-01

To understand the mechanism of intracerebroventricular transplantation of vascular endothelial growth factor (VEGF) genemodified bone mesenchymal stem cells (BMSCs) in rats after cerebral infarction. The middle cerebral artery occlusion ischemia/reperfusion (MCAO I/R) model was established in rats using the Zea-Longa suture method. A recombinant adenovirus (Ad-VEGF) was engineered to express VEGF. The rats were divided into 3 groups. Control BMSC infected with control adenovirus (BMSC-Ad), BMSC infected by Ad-VEGF (BMSC-Ad-VEGF), and phosphate buffered saline (PBS) suspension were injected into the intracerebroventricular system of the rats in groups 1, 2 and 3 respectively, 24 hours after middle cerebral artery occlusion (MCAO). The neurological function of rats was evaluated with the modified Neurological Severity Scores (mNSS). The infarct volume of brain in rats was determined using 2,3,5-triphenyltetrazolium chloride (TTC) stain at 14 days. GFAP and pGSK3β expression of ischemic penumbra was determined using immunohistochemical method. GFAP, pAKT, AKT, and pGSK3β expressions were determined with Western blot. Functional improvement was accelerated in animals receiving BMSC-Ad, while improvement at all times between 7 days and 28 days post MCAO was significantly greater in animals transplanted with BMSC-Ad-VEGF than for other treated animals. The number of GFAP-labeled cells was prevented by post-ischemic BMSC-Ad-VEGF treatment; pMCAO activate the PI3K/AKT/GSK3β pathway to reduce reactive gliosis. Our findings demonstrate that PI3K/AKT/GSK3β pathway could reduce reactive gliosis, ameliorate neurological deficit, diminish the percentage of cerebral infarction volume in rats, and facilitate angiogenesis.

l-Homocarnosine attenuates inflammation in cerebral ischemia-reperfusion injury through inhibition of nod-like receptor protein 3 inflammasome.

PubMed

Huang, Jing; Wang, Tao; Yu, Daorui; Fang, Xingyue; Fan, Haofei; Liu, Qiang; Yi, Guohui; Yi, Xinan; Liu, Qibin

2018-06-08

We investigated the therapeutic effects of l-homocarnosine against inflammation in a rat model of cerebral ischemia-reperfusion injury. Rats were grouped into control, middle cerebral artery occlusion (MCAO), 0.5 mM l-homocarnosine + MCAO, and 1 mM l-homocarnosine + MCAO treatment groups. Superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, lipid peroxidation, and reduced glutathione (GSH) levels were measured. Neurological scores were assessed, and histopathology, scanning electron microscopy (SEM), and fluorescence microscopy analyses were conducted. The mRNA expression levels of nod-like receptor protein 3 (NLRP3), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) and protein expression levels of NLRP3 were assessed. l-Homocarnosine supplementation substantially increased SOD, catalase, Gpx, and GSH levels, whereas it reduced the levels of lipid peroxidation relative to MCAO rats. l-Homocarnosine significantly reduced the infarct area and neurological deficit score, as well as histopathological alteration, apoptosis, and necrosis in brain tissue. The mRNA expression levels of NLRP3, TNF-α, and IL-6 were increased in MCAO rats, whereas l-homocarnosine supplementation reduced mRNA expression by >40%, and NLRP3 protein expression was reduced by >30% in 1 mM l-homocarnosine-treated MCAO rats. We propose that l-homocarnosine exerts a protective effect in cerebral ischemia-reperfusion injury-induced rats by downregulating NLRP3 expression. Copyright © 2017. Published by Elsevier B.V.

Docosahexaenoic acid complexed to albumin provides neuroprotection after experimental stroke in aged rats.

PubMed

Eady, Tiffany N; Khoutorova, Larissa; Obenaus, Andre; Mohd-Yusof, Alena; Bazan, Nicolas G; Belayev, Ludmila

2014-02-01

Recently we have shown that docosahexaenoic acid complexed to albumin (DHA-Alb) is neuroprotective after experimental stroke in young rats. The purpose of this study was to determine whether treatment with DHA-Alb would be protective in aged rats after focal cerebral ischemia. Isoflurane/nitrous oxide-anesthetized normothermic (brain temperature 36-36.5°C) Sprague-Dawley aged rats (18-months old) received 2h middle cerebral artery occlusion (MCAo) by poly-l-lysine-coated intraluminal suture. The neurological status was evaluated during occlusion (60min) and on days 1, 2, 3 and 7 after MCAo; a grading scale of 0-12 was employed. DHA (5mg/kg), Alb (0.63g/kg), DHA-Alb (5mg/kg+0.63g/kg) or saline was administered i.v. 3h after onset of stroke (n=8-10 per group). Ex vivo T2-weighted imaging (T2WI) of the brains was conducted on an 11.7T MRI on day 7 and 3D reconstructions were generated. Infarct volumes and number of GFAP (reactive astrocytes), ED-1 (activated microglia/microphages), NeuN (neurons)-positive cells and SMI-71 (positive vessels) were counted in the cortex and striatum at the level of the central lesion. Physiological variables were entirely comparable between groups. Animals treated with DHA-Alb showed significantly improved neurological scores compared to vehicle rats; 33% improvement on day 1; 39% on day 2; 41% on day 3; and 45% on day 7. Total and cortical lesion volumes computed from T2WI were significantly reduced by DHA-Alb treatment (62 and 69%, respectively). In addition, treatment with DHA-Alb reduced cortical and total brain infarction while promoting cell survival. We conclude that DHA-Alb therapy is highly neuroprotective in aged rats following focal cerebral ischemia and has potential for the effective treatment of ischemic stroke in aged individuals. © 2013. Published by Elsevier Inc. All rights reserved.

Calibration of the MCAO Canopus Bench

NASA Astrophysics Data System (ADS)

Garcia-Rissmann, Aurea; Rigaut, François; Bec, Matthieu; Boccas, Maxime; Galvez, Ramon; Gausachs, Gaston; Gratadour, Damien; Neichel, Benoit

The final phase of implementation of all optical components, as well as their integration and tests on the Canopus MCAO bench is currently underway. We present here a detailed description of the LGS and NGS WFS calibration sequences implemented through MYST (MCAO Yorick Smart Tool), a yorick+python+glade software package developed in-house which allows multiple users to control and monitor the bench remotely over the network using EPICS commands. A fine tuning of the optical setup and a better understanding of the flexure/temperature dependencies is being carried out and will allow us to build the many look-up tables to be eventually used by the system (e.g. telescope primary and secondary mirrors). Preliminary work on non-common path aberrations to account for the static aberrations in the central 60 arcsec science field of view (FoV) has been done iteratively using a science focal plane wavefront sensor and has shown good results both in individual directions as well as simultaneously over the entire FoV, the latter using the tomographic approach (presented in another paper in this conference).

Intraoperative laser speckle contrast imaging improves the stability of rodent middle cerebral artery occlusion model

NASA Astrophysics Data System (ADS)

Yuan, Lu; Li, Yao; Li, Hangdao; Lu, Hongyang; Tong, Shanbao

2015-09-01

Rodent middle cerebral artery occlusion (MCAO) model is commonly used in stroke research. Creating a stable infarct volume has always been challenging for technicians due to the variances of animal anatomy and surgical operations. The depth of filament suture advancement strongly influences the infarct volume as well. We investigated the cerebral blood flow (CBF) changes in the affected cortex using laser speckle contrast imaging when advancing suture during MCAO surgery. The relative CBF drop area (CBF50, i.e., the percentage area with CBF less than 50% of the baseline) showed an increase from 20.9% to 69.1% when the insertion depth increased from 1.6 to 1.8 cm. Using the real-time CBF50 marker to guide suture insertion during the surgery, our animal experiments showed that intraoperative CBF-guided surgery could significantly improve the stability of MCAO with a more consistent infarct volume and less mortality.

Combination cell therapy with mesenchymal stem cells and neural stem cells for brain stroke in rats.

PubMed

Hosseini, Seyed Mojtaba; Farahmandnia, Mohammad; Razi, Zahra; Delavari, Somayeh; Shakibajahromi, Benafsheh; Sarvestani, Fatemeh Sabet; Kazemi, Sepehr; Semsar, Maryam

2015-05-01

Brain stroke is the second most important events that lead to disability and morbidity these days. Although, stroke is important, there is no treatment for curing this problem. Nowadays, cell therapy has opened a new window for treating central nervous system disease. In some previous studies the Mesenchymal stem cells and neural stem cells. In this study, we have designed an experiment to assess the combination cell therapy (Mesenchymal and Neural stem cells) effects on brain stroke. The Mesenchymal stem cells were isolated from adult rat bone marrow and the neural stem cells were isolated from ganglion eminence of rat embryo 14 days. The Mesenchymal stem cells were injected 1 day after middle cerebral artery occlusion (MCAO) and the neural stem cells transplanted 7 day after MCAO. After 28 days, the neurological outcomes and brain lesion volumes were evaluated. Also, the activity of Caspase 3 was assessed in different groups. The group which received combination cell therapy had better neurological examination and less brain lesion. Also the combination cell therapy group had the least Caspase 3 activity among the groups. The combination cell therapy is more effective than Mesenchymal stem cell therapy and neural stem cell therapy separately in treating the brain stroke in rats.

Neuroprotective effect of agmatine in rats with transient cerebral ischemia using MR imaging and histopathologic evaluation.

PubMed

Huang, Y C; Tzeng, W S; Wang, C C; Cheng, B C; Chang, Y K; Chen, H H; Lin, P C; Huang, T Y; Chuang, T J; Lin, J W; Chang, C P

2013-09-01

This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation. Following surgical induction of MCAO for 90min, agmatine was injected 5min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3h-72h in a 1.5T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections. Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3h and peaked at 24h-48h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72h) point except for significantly smaller ADC lesions in the MCAO model (P<0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P<0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P<0.05). Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after

Effects of gemfibrozil on outcome after permanent middle cerebral artery occlusion in mice

PubMed Central

Guo, Qingmin; Wang, Guangming; Liu, Xiaowei; Namura, Shobu

2009-01-01

Fibrates are lipid lowering drugs and found as ligands for peroxisome proliferator-activated receptors (PPARs). A clinical study has shown that one type of fibrate gemfibrozil reduces stroke incidence in men. However, it remains unknown whether gemfibrozil improves outcome after stroke. We hypothesized that prophylactic administration of gemfibrozil improves outcome after ischemic stroke. In this study, we measured the impact of gemfibrozil in two permanent middle cerebral artery occlusion (MCAO) models in young adult male mice on normal diet. First, we tested gemfibrozil in a filamentous MCAO model. Pretreatment with gemfibrozil (30 mg/kg) for 7 days moderately but significantly reduced infarct size at 24 h after MCAO. A higher dose (120 mg/kg) did not attenuate infarct size. Rather, it tended to increase brain swelling. Second, we tested in a distal MCAO model. Gemfibrozil (30 mg/kg) for 7 days before and after stroke significantly attenuated cortical lesion size at 7 days after MCAO. Cortical blood flow measured by laser speckle imaging was improved by gemfibrozil in the ischemic hemisphere. In non-stroke animals gemfibrozil also altered gene expression levels of PPARs in both the aorta and brain in organ specific manners; however, endothelial nitric oxide synthase (eNOS) was not significantly affected. These findings suggested the possibility that the observed infarct reductions and cortical blood flow improvements in ischemic brains were not through eNOS-mediated mechanisms. Further investigations may be meritorious to examine whether prophylactic usage of gemfibrozil against stroke is beneficial. PMID:19427843

Effects of gemfibrozil on outcome after permanent middle cerebral artery occlusion in mice.

PubMed

Guo, Qingmin; Wang, Guangming; Liu, Xiaowei; Namura, Shobu

2009-07-07

Fibrates are lipid lowering drugs and found as ligands for peroxisome proliferator-activated receptors (PPARs). A clinical study has shown that one type of fibrate gemfibrozil reduces stroke incidence in men. However, it remains unknown whether gemfibrozil improves outcome after stroke. We hypothesized that prophylactic administration of gemfibrozil improves outcome after ischemic stroke. In this study, we measured the impact of gemfibrozil in two permanent middle cerebral artery occlusion (MCAO) models in young adult male mice on normal diet. First, we tested gemfibrozil in a filamentous MCAO model. Pretreatment with gemfibrozil (30 mg/kg) for 7 days moderately but significantly reduced infarct size at 24 h after MCAO. A higher dose (120 mg/kg) did not attenuate infarct size. Rather, it tended to increase brain swelling. Second, we tested in a distal MCAO model. Gemfibrozil (30 mg/kg) for 7 days before and after stroke significantly attenuated cortical lesion size at 7 days after MCAO. Cortical blood flow measured by laser speckle imaging was improved by gemfibrozil in the ischemic hemisphere. In non-stroke animals gemfibrozil also altered gene expression levels of PPARs in both the aorta and brain in organ specific manners; however, endothelial nitric oxide synthase (eNOS) was not significantly affected. These findings suggested the possibility that the observed infarct reductions and cortical blood flow improvements in ischemic brains were not through eNOS-mediated mechanisms. Further investigations may be meritorious to examine whether prophylactic usage of gemfibrozil against stroke is beneficial.

Dynamics of myelin content decrease in the rat stroke model

NASA Astrophysics Data System (ADS)

Kisel, A.; Khodanovich, M.; Atochin, D.; Mustafina, L.; Yarnykh, V.

2017-08-01

The majority of studies were usually focused on neuronal death after brain ischemia; however, stroke affects all cell types including oligodendrocytes that form myelin sheath in the CNS. Our study is focused on the changes of myelin content in the ischemic core and neighbor structures in early terms (1, 3 and 10 days) after stroke. Stroke was modeled with middle cerebral artery occlusion (MCAo) in 15 male rats that were divided into three groups by time points after operation. Brain sections were histologically stained with Luxol Fast Blue (LFB) for myelin quantification. The significant demyelination was found in the ischemic core, corpus callosum, anterior commissure, whereas myelin content was increased in caudoputamen, internal capsule and piriform cortex compared with the contralateral hemisphere. The motor cortex showed a significant increase of myelin content on the 1st day and a significant decrease on the 3rd and 10th days after MCAo. These results suggest that stroke influences myelination not only in the ischemic core but also in distant structures.

Pretreatment of 6-shogaol attenuates oxidative stress and inflammation in middle cerebral artery occlusion-induced mice.

PubMed

Na, Ji-Young; Song, Kibbeum; Lee, Ju-Woon; Kim, Sokho; Kwon, Jungkee

2016-10-05

6-Shogaol can be extracted from ginger and has been shown to exert anti-inflammatory and antioxidant activities, which are potentially relevant to the treatment of central nervous system disorders. Oxidative stress and inflammation are closely associated with ischemic injury and can eventually result in neuronal death. The aim of this study was to evaluate if 6-shogaol exerts neuroprotective activity. To this end, we determined its effects on oxidative stress and inflammation in a mouse model of middle cerebral artery occlusion (MCAO)-induced brain damage. In this model, MCAO was induced in C57BL/6 mice (30-35g, 9 weeks) for 1h, followed by 24h reperfusion. Mice were treated orally with 6-shogaol (0.1ml, 5 or 20mg/kg) once daily for 7 consecutive days prior to MCAO. We found that 6-shogaol significantly reduced neurological deficit scores and the mean infarct area. Moreover, 6-shogaol improved the behavioral deficits in the MCAO group. In addition, 6-shogaol pretreatment dampened MCAO-mediated production of reactive oxygen species and inflammatory cytokines. Mechanistic studies revealed that 6-shogaol inhibits the cysteinyl leukotriene 1 receptor (CysLT1R) and mitogen-activated protein kinase (MAPK) signaling proteins, thus providing a potential pharmacological mechanism for our observations. These results suggest that 6-shogaol can ameliorate the outcomes of MCAO and could thus be used as a potential preventive of stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

Integrated pharmacokinetics of major bioactive components in MCAO rats after oral administration of Huang-Lian-Jie-Du-Tang.

PubMed

Zhu, Huaxu; Qian, Zhilei; Li, Huan; Guo, Liwei; Pan, Linmei; Zhang, Qichun; Tang, Yuping

2012-05-07

Huang-Lian-Jie-Du-Tang (HLJDT, or Oren-gedoku-to in Japanese), an important multi-herb remedy in China and other Asia countries, has been used clinically to treat cerebral ischemia for decades. According to the previous studies we have reported, an HPLC method was developed and validated for determination of berberine, palmatine, baicalin, baicalein and geniposide simultaneously in MCAO rat plasma after administration of HLJDT aqueous extract. A classified integral pharmacokinetic method was put forward after having compared the integrated concentration-time profile with that of single component. An AUC based weighting approach was used for integrated principle. The results indicated the classified integral pharmacokinetic profile of index components from HLJDT could reveal the pharmacokinetic behavior of original components, and was corresponding to the holistic pharmacological effects of anti-ischemia with HLJDT. This study was aimed to explore an approach that could be applied to integrate the pharmacokinetic behavior of different components derived from HLJDT. The integrated pharmacokinetic results also provided more information for further understanding of the clinical cerebrovascular disease in use of HLJDT. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Neuroprotective capabilities of TSA against cerebral ischemia/reperfusion injury via PI3K/Akt signaling pathway in rats.

PubMed

Ma, Xiao-Hui; Gao, Qiang; Jia, Zhen; Zhang, Ze-Wei

2015-02-01

Hundreds of previous studies demonstrated the cytoprotective effect of trichostatin-A (TSA), a kind of histone deacetylases inhibitors (HDACIs), against cerebral ischemia/reperfusion insult. Meanwhile, phosphatidylinositol-3 kinase/Akt (PI3K/Akt) is a well-known, important signaling pathway that mediates neuroprotection. However, it should be remains unclear whether the neuroprotective capabilities of TSA against cerebral ischemia/reperfusion is mediated by activation of the PI3K/Akt signaling pathway. Five groups rats (n = 12 each), with middle cerebral artery occlusion (MCAO) except sham group, were used to investigate the neuroprotective effect of certain concentration (0.05 mg/kg) of TSA, and whether the neuroprotective effect of TSA is associated with activation of the PI3K/Akt signaling pathway through using of wortmannin (0.25 mg/kg). TSA significantly increased the expression of p-Akt protein, reduced infarct volume, and attenuated neurological deficit in rats with transient MCAO, wortmannin weakened such effect of TSA dramatically. TSA could significantly decrease the neurological deficit scores and reduce the cerebral infarct volume during cerebral ischemia/reperfusion injury, which was achieved partly by activation of the PI3K/Akt signaling pathway via upgrading of p-Akt protein.

The Vermicelli Handling Test: A Simple Quantitative Measure of Dexterous Forepaw Function in Rats

PubMed Central

Allred, Rachel P.; Adkins, DeAnna L.; Woodlee, Martin T.; Husbands, Lincoln C.; Maldonado, Mónica A.; Kane, Jacqueline R.; Schallert, Timothy; Jones, Theresa A.

2008-01-01

Loss of function in the hands occurs with many brain disorders, but there are few measures of skillful forepaw use in rats available to model these impairments that are both sensitive and simple to administer. Whishaw and Coles (1996) previously described the dexterous manner in which rats manipulate food items with their paws, including thin pieces of pasta. We set out to develop a measure of this food handling behavior that would be quantitative, easy to administer, sensitive to the effects of damage to sensory and motor systems of the CNS and useful for identifying the side of lateralized impairments. When rats handle 7 cm lengths of vermicelli, they manipulate the pasta by repeatedly adjusting the forepaw hold on the pasta piece. As operationally defined, these adjustments can be easily identified and counted by an experimenter without specialized equipment. After unilateral sensorimotor cortex (SMC) lesions, transient middle cerebral artery occlusion (MCAO) and striatal dopamine depleting (6-hydroxydopamine, 6-OHDA) lesions in adult rats, there were enduring reductions in adjustments made with the contralateral forepaw. Additional pasta handling characteristics distinguished between the lesion types. MCAO and 6-OHDA lesions increased the frequency of several identified atypical handling patterns. Severe dopamine depletion increased eating time and adjustments made with the ipsilateral forepaw. However, contralateral forepaw adjustment number most sensitively detected enduring impairments across lesion types. Because of its ease of administration and sensitivity to lateralized impairments in skilled forepaw use, this measure may be useful in rat models of upper extremity impairment. PMID:18325597

Electroacupuncture improves cerebral blood flow and attenuates moderate ischemic injury via Angiotensin II its receptors-mediated mechanism in rats.

PubMed

Li, Jing; He, Jiaojun; Du, Yuanhao; Cui, Jingjun; Ma, Ying; Zhang, Xuezhu

2014-11-11

To investigate the effects and potential mechanism of electroacupuncture intervention on expressions of Angiotensin II and its receptors-mediated signaling pathway in experimentally induced cerebral ischemia. Totally 126 male Wistar rats were randomly divided into control group, model group and EA group. The latter two were further divided into ten subgroups (n = 6) following Middle Cerebral Artery Occlusion (MCAO). Changes in regional cerebral blood flow (rCBF) and expressions of Angiotensin II and its receptors (AT1R, AT2R), as well as effector proteins in phosphatidyl inositol signal pathway were monitored before and at different times after MCAO. MCAO-induced decline of ipsilateral rCBF was partially suppressed by electroacupuncture, and contralateral blood flow was also superior to that of model group. Angiotensin II level was remarkably elevated immediately after MCAO, while electroacupuncture group exhibited significantly lower levels at 1 to 3 h and the value was significantly increased thereafter. The enhanced expression of AT1R was partially inhibited by electroacupuncture, while increased AT2R level was further induced. Electroacupuncture stimulation attenuated and postponed the upregulated-expressions of Gq and CaM these upregulations. ELISA results showed sharply increased expressions of DAG and IP3, which were remarkably neutralized by electroacupuncture. MCAO induced significant increases in expression of Angiotensin II and its receptor-mediated signal pathway. These enhanced expressions were significantly attenuated by electroacupuncture intervention, followed by reduced vasoconstriction and improved blood supply in ischemic region, and ultimately conferred beneficial effects on cerebral ischemia.

Effect of Buyang Huanwu decoction on amino acid content in cerebrospinal fluid of rats during ischemic/reperfusion injury.

PubMed

Wang, Lisheng; Huang, Yuwei; Wu, Junhong; Lv, Gengbin; Zhou, Liling; Jia, Jie

2013-12-01

The inhibitory effect of Buyang Huanwu decoction (BYHWD) on ischemic injury has been proven, but it is not clear how amino acid levels in cerebrospinal fluid (CSF) are associated with BYHWD treatment, nor the mechanism by which BYHWD protects the brain from ischemia/reperfusion injury. We investigated the effect of BYHWD on the amino acid content of CSF in rats during ischemia-reperfusion injury. Ischemia was imposed by right middle cerebral artery occlusion (MCAO). CSF was continuously collected from the striatum via brain microdialysis before and after ischemia/reperfusion. We used on-line derivatization combined with high-performance liquid chromatography with fluorescence detection (HPLC-FD) to determine levels of glutamate (Glu), aspartate (Asp), glycine (Gly), taurine (Tau), and γ-aminobutyric acid (GABA) in CSF. The MCAO model displayed an infarct lesion in the ipsilateral hemisphere and nerve injuries, as the left upper limb was unable to extend and turn leftward. Significant increases in excitatory and inhibitory amino acids were observed in the CSF of the ischemic rats relative to the sham-operated group (P<0.01). Treatment with BYHWD reduced the areas of cerebral infarction and improved the neurological behavior scores of rats after MCAO. BYHWD treatment was also associated with a significant decrease in excitatory amino acids and increase in inhibitory amino acids in the CSF. Only the higher dose of BYHWD (20mg/kg) affected all these levels significantly. Attenuated excitatory toxicity and reduced areas of cerebral infarction associated with BYHWD treatment might be due to a protective mechanism induced by BYHWD against ischemia/reperfusion injury. Copyright © 2013 Elsevier B.V. All rights reserved.

Optimization of behavioural tests for the prediction of outcomes in mouse models of focal middle cerebral artery occlusion.

PubMed

Wen, Zhuoyu; Xu, Xiaomeng; Xu, Lili; Yang, Lian; Xu, Xiaohui; Zhu, Juehua; Wu, Li; Jiang, Yongjun; Liu, Xinfeng

2017-06-15

Intraluminal middle cerebral artery occlusion (MCAO) is the most widely used model of stroke. We aimed to predict the outcome of MCAO using a combination of fine behavioural tests for the prediction of unsuccessful surgery in mice leading to no infarction, haemorrhage and unexpected death. MCAO was performed on adult mice under the guidance of laser-Doppler flowmetry (LDF) to warrant a decrease in regional cerebral blood flow (rCBF) in the MCA territory. Four outcomes of MCAO were defined according to histological analysis: infarction, no infarction, haemorrhage and unexpected death (death within 24h post-surgery). Fine behavioural tests including the rotarod, modified neurological severity score (mNSS), Clark general and Clark focal tests were performed separately at 6h, 12h and 24h post-stroke. A total of 94 mice were included in the analysis. The infarction rate associated with MCAO was 58.5% (55/94). After optimization of the timing and behavioural tests, we found that higher Clark focal (>17.5) or higher mNSS scores (>10) were markedly related to early death, whereas a lower mNSS score (<3.5) was indicative of a tendency to show no infarction at 6h post-stroke. After 24h post-stroke, there was a positive correlation between the infarct volume and Clark focal results. Behavioural tests could help to predict the outcomes in the MCAO mouse model. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Involvement of brain-gut axis in treatment of cerebral infarction by β-asaron and paeonol.

PubMed

He, Xiaogang; Cai, Qiufang; Li, Jianxiang; Guo, Weifeng

2018-02-14

Cerebral infarction (CI) causes severe brain damage with high incidence. This study aimed to investigate the involvement of brain-gut axis in the treatment of CI by combined administration of β-asaron and paeonol. Rat middle cerebral artery occlusion (MCAO) model was established, the interleukin-1beta (IL-1β) and tumor necrosis factor α (TNF-α) in the rat peripheral blood were determined by ELISA assay, and brain tissue damage was evaluated by TUNNEL assay. The correlation of cholecystokinin (CCK) and nuclear factor-kappaB (NF-κB) signaling components between intestinal mucosa and prefrontal cortex of MCAO rats treated with β-asaron and paeonol were analyzed by quantitative RT-PCR and western blotting. In vitro transwell co-culture was performed to confirm the correlated expression. The expression of CCK and NF-κB signaling components were closely correlated between the intestinal mucosa and prefrontal cortex of MCAO rats treated with β-asaron and paeonol. The combined administration also regulates the IL-1β and TNF-α in the MCAO rat peripheral blood and ameliorate the brain damage in MCAO rats. Elevated expression of related genes was observed in the cortical neurons co-cultured with intestinal mucosal epithelial cells treated by β-asaron and paeonol. The brain-gut axis mediates the therapeutic effect of β-asaron and paeonol for cerebral infarction through CCK and NF-κB signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

Breviscapine confers a neuroprotective efficacy against transient focal cerebral ischemia by attenuating neuronal and astrocytic autophagy in the penumbra.

PubMed

Pengyue, Zhang; Tao, Guo; Hongyun, He; Liqiang, Yang; Yihao, Deng

2017-06-01

Breviscapine is a flavonoid derived from a traditional Chinese herb Erigerin breviscapus (Vant.) Hand-Mazz, and has been extensively used in clinical treatment for cerebral stroke in China, but the underlying pharmacological mechanisms are still unclear. In present study, we investigated whether breviscapine could confer a neuroprotection against cerebral ischemia injury by targeting autophagy mechanisms. A cerebral stroke model in Sprague-Dawley rats was prepared by middle cerebral artery occlusion (MCAO), rats were then randomly divided into 5 groups: MCAO+Bre group, rats were treated with breviscapine; MCAO+Tat-Beclin-1 group, animals were administrated with specific autophagy inducer Tat-Beclin-1; MCAO+Bre+Tat-Beclin-1 group, rats were treated with both breviscapine and Tat-Beclin-1, MCAO+saline group, rats received the same volume of physiological saline, and Sham surgery group. The autophagy levels in infarct penumbra were evaluated by western blotting, real-time PCR and immunofluorescence 7days after the insult. Meanwhile, infarct volume, brain water content and neurological deficit score were assessed. The results illustrated that the infarct volume, brain water content and neurofunctional deficiency were significantly reduced by 7days of breviscapine treatment in MCAO+Bre group, compared with those in MCAO+saline group. Meanwhile, the western blotting, quantitative PCR and immunofluorescence showed that the autophagy in both neurons and astrocytes at the penumbra were markedly attenuated by breviscapine admininstration. Moreover, these pharmacological effects of breviscapine could be counteracted by autophagy inducer Tat-Beclin-1. Our study suggests that breviscapine can provide a neuroprotection against transient focal cerebral ischemia, and this biological function is associated with attenuating autophagy in both neurons and astrocytes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Biochemical and inflammatory biomarkers in ischemic stroke: translational study between humans and two experimental rat models

PubMed Central

2014-01-01

Background our objective was to examine the plasma levels of three biological markers involved in cerebral ischemia (IL-6, glutamate and TNF-alpha) in stroke patients and compare them with two different rat models of focal ischemia (embolic stroke model- ES and permanent middle cerebral artery occlusion ligation model-pMCAO) to evaluate which model is most similar to humans. Secondary objectives: 1) to analyze the relationship of these biological markers with the severity, volume and outcome of the brain infarction in humans and the two stroke models; and 2) to study whether the three biomarkers are also increased in response to damage in organs other than the central nervous system, both in humans and in rats. Methods Multi-center, prospective, case-control study including acute stroke patients (n = 58) and controls (n = 19) with acute non-neurological diseases Main variables: plasma biomarker levels on admission and at 72 h; stroke severity (NIHSS scale) and clinical severity (APACHE II scale); stroke volume; functional status at 3 months (modified Rankin Scale [mRS] and Barthel index [BI]). Experimental groups: ES (n = 10), pMCAO (n = 6) and controls (tissue stress by leg compression) (n = 6). Main variables: plasma biomarker levels at 3 and 72 h; volume of ischemic lesion (H&E) and cell death (TUNEL). Results in stroke patients, IL-6 correlated significantly with clinical severity (APACHE II scale), stroke severity (NIHSS scale), infarct volume (cm3) and clinical outcome (mRS) (r = 0.326, 0.497, 0.290 and 0.444 respectively; P < 0.05). Glutamate correlated with stroke severity, but not with outcome, and TNF-alpha levels with infarct volume. In animals, The ES model showed larger infarct volumes (median 58.6% vs. 29%, P < 0.001) and higher inflammatory biomarkers levels than pMCAO, except for serum glutamate levels which were higher in pMCAO. The ES showed correlations between the biomarkers and cell death (r = 0.928 for IL-6

Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke.

PubMed

Ma, Junqiang; Ma, Yonglie; Dong, Bin; Bandet, Mischa V; Shuaib, Ashfaq; Winship, Ian R

2017-08-01

Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80-90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105-110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.

High-density lipoprotein-based therapy reduces the hemorrhagic complications associated with tissue plasminogen activator treatment in experimental stroke.

PubMed

Lapergue, Bertrand; Dang, Bao Quoc; Desilles, Jean-Philippe; Ortiz-Munoz, Guadalupe; Delbosc, Sandrine; Loyau, Stéphane; Louedec, Liliane; Couraud, Pierre-Olivier; Mazighi, Mikael; Michel, Jean-Baptiste; Meilhac, Olivier; Amarenco, Pierre

2013-03-01

We have previously reported that intravenous injection of high-density lipoproteins (HDLs) was neuroprotective in an embolic stroke model. We hypothesized that HDL vasculoprotective actions on the blood-brain barrier (BBB) may decrease hemorrhagic transformation-associated with tissue plasminogen activator (tPA) administration in acute stroke. We used tPA alone or in combination with HDLs in vivo in 2 models of focal middle cerebral artery occlusion (MCAO) (embolic and 4-hour monofilament MCAO) and in vitro in a model of BBB. Sprague-Dawley rats were submitted to MCAO, n=12 per group. The rats were then randomly injected with tPA (10 mg/kg) or saline with or without human plasma purified-HDL (10 mg/kg). The therapeutic effects of HDL and BBB integrity were assessed blindly 24 hours later. The integrity of the BBB was also tested using an in vitro model of human cerebral endothelial cells under oxygen-glucose deprivation. tPA-treated groups had significantly higher mortality and rate of hemorrhagic transformation at 24 hours in both MCAO models. Cotreatment with HDL significantly reduced stroke-induced mortality versus tPA alone (by 42% in filament MCAO, P=0.009; by 73% in embolic MCAO, P=0.05) and tPA-induced intracerebral parenchymal hematoma (by 92% in filament MCAO, by 100% in embolic MCAO; P<0.0001). This was consistent with an improved BBB integrity. In vitro, HDLs decreased oxygen-glucose deprivation-induced BBB permeability (P<0.05) and vascular endothelial cadherin disorganization. HDL injection decreased tPA-induced hemorrhagic transformation in rat models of MCAO. Both in vivo and in vitro results support the vasculoprotective action of HDLs on BBB under ischemic conditions.

Effects of exercise intensity on spatial memory performance and hippocampal synaptic plasticity in transient brain ischemic rats.

PubMed

Shih, Pei-Cheng; Yang, Yea-Ru; Wang, Ray-Yau

2013-01-01

Memory impairment is commonly noted in stroke survivors, and can lead to delay of functional recovery. Exercise has been proved to improve memory in adult healthy subjects. Such beneficial effects are often suggested to relate to hippocampal synaptic plasticity, which is important for memory processing. Previous evidence showed that in normal rats, low intensity exercise can improve synaptic plasticity better than high intensity exercise. However, the effects of exercise intensities on hippocampal synaptic plasticity and spatial memory after brain ischemia remain unclear. In this study, we investigated such effects in brain ischemic rats. The middle cerebral artery occlusion (MCAO) procedure was used to induce brain ischemia. After the MCAO procedure, rats were randomly assigned to sedentary (Sed), low-intensity exercise (Low-Ex), or high-intensity exercise (High-Ex) group. Treadmill training began from the second day post MCAO procedure, 30 min/day for 14 consecutive days for the exercise groups. The Low-Ex group was trained at the speed of 8 m/min, while the High-Ex group at the speed of 20 m/min. The spatial memory, hippocampal brain-derived neurotrophic factor (BDNF), synapsin-I, postsynaptic density protein 95 (PSD-95), and dendritic structures were examined to document the effects. Serum corticosterone level was also quantified as stress marker. Our results showed the Low-Ex group, but not the High-Ex group, demonstrated better spatial memory performance than the Sed group. Dendritic complexity and the levels of BDNF and PSD-95 increased significantly only in the Low-Ex group as compared with the Sed group in bilateral hippocampus. Notably, increased level of corticosterone was found in the High-Ex group, implicating higher stress response. In conclusion, after brain ischemia, low intensity exercise may result in better synaptic plasticity and spatial memory performance than high intensity exercise; therefore, the intensity is suggested to be considered

Aging causes exacerbated ischemic brain injury and failure of sevoflurane post-conditioning: role of B-cell lymphoma-2.

PubMed

Dong, P; Zhao, J; Zhang, Y; Dong, J; Zhang, L; Li, D; Li, L; Zhang, X; Yang, B; Lei, W

2014-09-05

Aging is associated with exacerbated brain injury after ischemic stroke. Herein, we explored the possible mechanisms underlying the age-associated exacerbated brain injury after ischemic stroke and determined whether therapeutic intervention with anesthetic post-conditioning would provide neuroprotection in aged rats. Male Fisher 344 rats (young, 4 months; aged, 24 months) underwent 2h of middle cerebral artery occlusion (MCAO) followed by 24-h reperfusion, with or without sevoflurane post-conditioning for 15 min immediately at the onset of reperfusion. Compared with young rats, aged rats showed larger infarct size, worse neurological scores and more TUNEL-positive cells in the penumbral cerebral cortex at 24h after MCAO. However, edema formation and motor coordination were similar in both groups. Sevoflurane reduced the infarct size, edema formation, and TUNEL-positive cells, and improved the neurological outcome in young rats but not in aged rats. Molecular studies revealed that basal expression of the anti-apoptotic molecule B-cell lymphoma-2 (Bcl-2) in the brain was lower in aged rats compared with young rats before MCAO, while basal expression of the pro-apoptotic molecule Bcl-2-associated X protein (Bax) showed similar levels in both groups. MCAO reduced Bcl-2 expression and increased Bax expression in both groups; however, Bax increase was more pronounced in aged rats. In young rats, sevoflurane reversed the above MCAO-induced changes. In contrast, sevoflurane failed to enhance Bcl-2 expression but decreased Bax expression in aged rats. These findings suggest that aging-associated reduction in basal Bcl-2 expression in the brain contributes to increased neuronal injury by enhancing cell apoptosis after ischemic stroke. Sevoflurane post-conditioning failed to provide neuroprotection in aged rats, probably due to its inability to increase Bcl-2 levels and prevent apoptosis in the brain. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model

PubMed Central

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-01-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology. PMID:25690471

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model.

PubMed

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-06-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

Laser targeted photo-occlusion of rat choroidal neovascularization without collateral damage.

PubMed

Nishiwaki, Hirokazu; Zeimer, Ran; Goldberg, Morton F; D'Anna, Salvatore A; Vinores, Stanley A; Grebe, Rhonda

2002-02-01

Laser targeted photo-occlusion (LTO) is a novel method being developed to treat choroidal neovascular membranes (CNV) in age-related and other macular degenerations. A photosensitive agent, encapsulated in heat-sensitive liposomes, is administered intravenously. A low power laser warms the targeted tissue and releases a bolus of photosensitizer. The photosensitizer is activated after it clears from the normal choriocapillaris but not from the CNV. Forty-five experimental CNV were induced in seven rats. Five weeks after LTO, complete occlusion was observed by laser targeted angiography (LTA) in 76% of treated CNV, and partial occlusion was found in the remaining 24%. The tissues outside the CNV but within the area treated by LTO showed no flow alteration and no dye leakage. All untreated CNV were patent on LTA at 5 weeks. Light microscopy and electron microscopy confirmed the results in treated and control lesions. Moreover, treated areas next to lesions showed normal photoreceptors, retinal pigment epithelium (RPE), Bruch's membrane and choriocapillaris. These results indicate that LTO may improve current photodynamic therapy by alleviating the need for repeated treatments and by avoiding the long-term risks associated with damage to the RPE and occlusion of normal choriocapillaries.

The Neuroprotective Effects of Flaxseed Oil Supplementation on Functional Motor Recovery in a Model of Ischemic Brain Stroke: Upregulation of BDNF and GDNF.

PubMed

Bagheri, Abolqasem; Talei, Sahand; Hassanzadeh, Negar; Mokhtari, Tahmineh; Akbari, Mohammad; Malek, Fatemeh; Jameie, Seyed Behnamedin; Sadeghi, Yousef; Hassanzadeh, Gholamreza

2017-12-01

Cerebral ischemic stroke is a common leading cause of disability. Flaxseed is a richest plant-based source of antioxidants. In this study, the effects of flaxseed oil (FSO) pretreatment on functional motor recovery and gene expression and protein content of neurotrophic factors in motor cortex area in rat model of brain ischemia/reperfusion (I/R) were assessed. Transient middle cerebral artery occlusion (tMCAo) in rats was used as model brain I/R. Rats (6 in each group) were randomly divided into four groups of Control (Co+normal saline [NS]), Sham (Sh+NS), tMCAo+NS and tMCAo+FSO. After three weeks of pretreatment with vehicle or FSO (0.2 ml~800 mg/kg body weight), the rats were operated in sham and ischemic groups. Ischemia was induced for 1 h and then reperfused. After 24 h of reperfusion, neurological examination was performed, and animals were sacrificed, and their brains were used for molecular and histopathological studies. FSO significantly improved the functional motor recovery compared with tMCAo+NS group (P<0.05). A significant reduction in brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) mRNAs and protein levels were observed in the tMCAo+NS group compared with Co+NS and Sh+NS group (P<0.05). A significant increase of BDNF and GDNF mRNAs and proteins was recorded in the tMCAo+FSO group compared with Co+NS, Sh+NS and tMCAO+NS groups (P<0.05). The results of the current study demonstrated that pretreatment with FSO had neuroprotective effects on motor cortex area following cerebral ischemic stroke by increasing the neurotrophic factors (BDNF, GDNF).

Oestradiol supplement minimises coronary occlusion-induced myocardial infarction and ventricular dysfunction in oophorectomised female rats.

PubMed

Zheng, Xiao-Pu; Ma, Ai-Qun; Dong, An-Ping; Wang, Shun; Jiang, Wen-Hui; Wang, Ting-Zhong; Fan, Fen-Ling; Ling, Shanhong

2011-09-15

Endogenous oestrogen deficiency after menopause is associated with high risk of acute cardiac events and the protection of exogenous oestrogen supplements remains uncertain. This study investigates whether oestrogen therapy protects the heart from ischemic injury in oophorectomised rats. Sexually mature female Sprague-Dawley rats (6 for each group) with bilateral oophorectomy underwent selective ligation (occlusion) of left coronary artery for 4 weeks. 17β-oestradiol (E2) supplements (10 μg, i.m., every other day) were started before (preventive-therapeutic supplement) or after coronary occlusion (therapeutic supplement). In oophorectomised rats plasma levels of E2 declined from 1301 ± 80 to 196 ± 48 pmol/L (p<0.01) and cardiac expression of oestrogen receptors (ER) decreased by ∼60%. E2 supplements recovered the ER expression. Selective ligation of left coronary led myocardial infarction in the left ventricle, with an increase in plasma cardiac troponin I (cTn-I), decrease in systolic blood pressure (SBP), and reduction of left ventricular pressures. Preventive-therapeutic but not therapeutic E2 supplement reduced cTn-I levels (from 21.9 ± 2.0 to 6.0 ± 0.3 ng/mL, p<0.01), minimised infarction (from 37.0 ± 1.2% to 18.1 ± 2.3%, p<0.05), increased SBP (from 82 ± 4.2 to 97 ± 4.4mm Hg, p<0.05), and improved left ventricular end pressures in the oophorectomised rats following coronary occlusion. Postmenopausal (ooporectomised) oestrogen supplement commenced before establishment of myocardial ischemia minimises myocardial infarction and ventricular dysfunction following the coronary artery occlusion. Cellular and molecular mechanisms underlying the cardiac protection of oestrogen therapy remain unclear, in which activation of cardiac ER expression and increasing in circulating CD90(+) stem cells may be involved. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Preventive Effect of Cashew-Derived Protein Hydrolysate with High Fiber on Cerebral Ischemia

PubMed Central

Thukham-mee, Wipawee; Wannanon, Panakaporn; Tiamkao, Somsak

2017-01-01

This study aimed to determine the protective effect of cashew nut-derived protein hydrolysate with high dietary fiber (AO) in cerebral ischemic rats induced by the occlusion of right middle cerebral artery (Rt.MCAO). Acute toxicity was determined and data showed that LD50 of AO > 5000 mg/kg BW. To determine the cerebroprotective effect of AO, male Wistar rats were orally given AO at doses of 2, 10, and 50 mg/kg for 14 days and subjected to Rt.MCAO. Brain infarction volume, neurological score, spatial memory, serum lipid profiles, and C-reactive protein together with the brain oxidative stress status were assessed. All doses of AO significantly decreased brain infarction in cortex, hippocampus, and striatum together with the decreased oxidative stress status. The improvement of spatial memory and serum C-reactive protein were also observed in MCAO rats which received AO at all doses. In addition, the decreased serum cholesterol, TG, and LDL but increased HDL were observed in MCAO rats which received high dose of AO. Taken all together, AO is the potential protectant against cerebral ischemia. The improvement of oxidative stress, inflammation, and dyslipidemia might play roles in the actions. However, further researches are required to understand the precise underlying mechanism. PMID:29457029

Middle Cerebral Artery Occlusion Model of Stroke in Rodents: A Step-by-Step Approach

PubMed Central

Shahjouei, Shima; Cai, Peter Y.; Ansari, Saeed; Sharififar, Sharareh; Azari, Hassan; Ganji, Sarah; Zand, Ramin

2016-01-01

Stroke is one of the leading causes of morbidity and mortality in developed countries and an immense amount of medical care resources are devoted to combat the poststroke debilitating consequences. The key to develop effective and clinically applicable treatment methodologies is a better understanding of the pathophysiology of the disease, including the root causes and targets for pharmacology. Developing these foundations requires the use of standard animal models that mimic the physicochemical process of the diseases that can reliably replicate results in order to test and fine-tune therapeutic modalities. Middle cerebral artery occlusion (MCAO), endothelin-1-induced ischemic stroke, photothrombosis, devascularization, embolization, and spontaneous infarction using hemorrhage are some examples of different animal models. Reliability of MCAO has been proved and due to the ability to induce reperfusion similar to tissue plasminogen activator (tPA) therapy, this model is widely used in preclinical studies. Here, we describe a detailed methodology on how to develop MCAO stroke in rodents using intra-arterial insertion of filament to occlude the middle cerebral artery. This approach allows for the study of a wide array of basic pathophysiology mechanisms, regenerative medicine and rehabilitation therapy. PMID:26958146

Extracerebral Tissue Damage in the Intraluminal Filament Mouse Model of Middle Cerebral Artery Occlusion

PubMed Central

Vaas, Markus; Ni, Ruiqing; Rudin, Markus; Kipar, Anja; Klohs, Jan

2017-01-01

Middle cerebral artery occlusion is the most common model of focal cerebral ischemia in the mouse. In the surgical procedure, the external carotid artery (ECA) is ligated; however, its effect on the tissue supplied by the vessel has not been described so far. C57BL/6 mice underwent 1 h of transient MCAO (tMCAO) or sham surgery. Multi-spectral optoacoustic tomography was employed at 30 min after surgery to assess oxygenation in the temporal muscles. Microstructural changes were assessed with magnetic resonance imaging and histological examination at 24 h and 48 h after surgery. Ligation of the ECA resulted in decreased oxygenation of the left temporal muscle in most sham-operated and tMCAO animals. Susceptible mice of both groups exhibited increased T2 relaxation times in the affected muscle with histological evidence of myofibre degeneration, interstitial edema, and neutrophil influx. Ligatures had induced an extensive neutrophil-dominated inflammatory response. ECA ligation leads to distinct hypoxic degenerative changes in the tissue of the ECA territory and to ligature-induced inflammatory processes. An impact on outcome needs to be considered in this stroke model. PMID:28348545

Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversal.

PubMed

Lohiya, N K; Suthar, R; Khandelwal, A; Goyal, S; Ansari, A S; Manivannan, B

2010-02-01

The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F(1) progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F(1) progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO.

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

PubMed Central

Wattanathorn, Jintanaporn; Jittiwat, Jinatta; Tongun, Terdthai; Muchimapura, Supaporn; Ingkaninan, Kornkanok

2011-01-01

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia. PMID:21197427

[Effects of introduction of short peptides before carotid artery occlusion on behaviour and caspase-3 activity in the brain of old rats].

PubMed

Mendzheritskiĭ, A M; Karantysh, G V; Ivonina, K O

2011-01-01

The comparative research of effect of Pinealon and Cortexin on behavior and activity of caspase-3 in a brain of old rats in a model of carotid arteries occlusion was conducted. It is shown that introduction of short peptides promotes a survival rate of the animals that have modeled occlusion of carotid arteries. Under Pinealon before occlusion of carotid arteries, behavioral dream has been increased and a position-finding behavior, a motivational behavior and a motor performance have been reduced. The rats that were introduced Cortexin before carotid arteries occlusion demonstrated the raise of behavioral dream time. At introduction of Pinealon activity of caspase-3 moderately raises in false-operated animals and in a model of occlusion of carotid arteries.

A free radical scavenger edaravone suppresses systemic inflammatory responses in a rat transient focal ischemia model

PubMed Central

Fujiwara, Norio; Som, Angel T.; Pham, Loc-Duyen D.; Lee, Brian J.; Mandeville, Emiri T.; Lo, Eng H.; Arai, Ken

2017-01-01

A free radical scavenger edaravone is clinically used in Japan for acute stroke, and several basic researches have carefully examined the mechanisms of edaravone's protective effects. However, its actions on pro-inflammatory responses under stroke are still understudied. In this study, we subjected adult male Sprague-Dawley rats to 90-min middle cerebral artery (MCA) occlusion followed by reperfusion. Edaravone was treated twice via tail vein; after MCA occlusion and after reperfusion. As expected, edaravone-treated group showed less infarct volume and edema formation compared with control group at 24-hour after ischemic onset. Furthermore, edaravone reduced the levels of plasma interleukin (IL)-1β and matrix metalloproteinase-9 at 3-hour after ischemic onset. Several molecules besides IL-1β and MMP-9 are involved in inflammatory responses under stroke conditions. Therefore, we also examined whether edaravone treatment could decrease a wide range of pro-inflammatory cytokines/chemokines by testing rat plasma samples with a rat cytokine array. MCAO rats showed elevations in plasma levels of CINC-1, Fractalkine, IL-1α, IL-1ra, IL-6, IL-10, IP-10, MIG, MIP-1α, and MIP-3α, and all these increases were reduced by edaravone treatment. These data suggest that free radical scavengers may reduce systemic inflammatory responses under acute stroke conditions, and therefore, oxidative stress can be still a viable target for acute stroke therapy. PMID:27589890

Neuroprotection by the Traditional Chinese Medicine, Tao-Hong-Si-Wu-Tang, against Middle Cerebral Artery Occlusion-Induced Cerebral Ischemia in Rats

PubMed Central

Wu, Chih-Jen; Chen, Jui-Tai; Yen, Ting-Lin; Jayakumar, Thanasekaran; Chou, Duen-Suey; Hsiao, George; Sheu, Joen-Rong

2011-01-01

Tao-Hong-Si-Wu-Tang (THSWT) is a famous traditional Chinese medicine (TMC). In the present study, oral administration of THSWT (0.7 and 1.4 g kg−1day−1) for 14 days before MCAO dose-dependently attenuated focal cerebral ischemia in rats. MCAO-induced focal cerebral ischemia was associated with increases in hypoxia-inducible factor (HIF)-1α, inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, and active caspase-3 expressions in ischemic regions. These expressions were obviously inhibited by 0.7 g kg−1day−1 THSWT treatment. In addition, THSWT inhibited platelet aggregation stimulated by collagen in washed platelets. In an in vivo study, THSWT (16 g kg−1) significantly prolonged platelet plug formation in mice. However, THSWT (20 and 40 μg mL−1) did not significantly reduce the electron spin resonance (ESR) signal intensity of hydroxyl radical (OH•) formation. In conclusion, the most important findings of this study demonstrate for the first time that THSWT possesses potent neuroprotective activity against MCAO-induced focal cerebral ischemia in vivo. This effect may be mediated, at least in part, by the inhibition of both HIF-1α and TNF-α activation, followed by the inhibition of inflammatory responses (i.e., iNOS expression), apoptosis formation (active caspase-3), and platelet activation, resulting in a reduction in the infarct volume in ischemia-reperfusion brain injury. PMID:21076527

Pericyte protection by edaravone after tissue plasminogen activator treatment in rat cerebral ischemia

PubMed Central

Deguchi, Kentaro; Liu, Ning; Liu, Wentao; Omote, Yoshio; Kono, Syoichiro; Yunoki, Taijun; Deguchi, Shoko; Yamashita, Toru; Ikeda, Yoshio; Abe, Koji

2014-01-01

Pericytes play a pivotal role in contraction, mediating inflammation and regulation of blood flow in the brain. In this study, changes of pericytes in the neurovascular unit (NVU) were examined in relation to the effects of exogenous tissue plasminogen activator (tPA) and a free radical scavenger, edaravone. Immunohistochemistry and Western blot analyses showed that the overlap between platelet-derived growth factor receptor β-positive pericytes and N-acetylglucosamine oligomers (NAGO)-positive endothelial cells increased significantly at 4 days after 90 min of transient middle cerebral artery occlusion (tMCAO). The number of pericytes and the overlap with NAGO decreased with tPA but recovered with edaravone 4 days after tMCAO with proliferation. Thus, tPA treatment damaged pericytes, resulting in the detachment from astrocytes and a decrease in glial cell line-derived neurotrophic factor secretion. However, treatment with edaravone greatly improved tPA-induced damage to pericytes. The present study demonstrates that exogenous tPA strongly damages pericytes and destroys the integrity of the NVU, but edaravone treatment can greatly ameliorate such damage after acute cerebral ischemia in rats. © 2014 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc. PMID:24938625

Oxygen therapy reduces secondary hemorrhage after thrombolysis in thromboembolic cerebral ischemia.

PubMed

Sun, Li; Zhou, Wei; Mueller, Christian; Sommer, Clemens; Heiland, Sabine; Bauer, Alexander T; Marti, Hugo H; Veltkamp, Roland

2010-09-01

Hyperbaric oxygen (HBO) and normobaric hyperoxia (NBO) protect the brain parenchyma and the cerebral microcirculation against ischemia. We studied their effect on secondary hemorrhage after thrombolysis in two thromboembolic middle cerebral artery occlusion (MCAO) (tMCAO) models. Beginning 60 minutes after tMCAO with either thrombin-induced thromboemboli (TT) or calcium-induced thromboemboli (CT), spontaneously hypertensive rats (n=96) breathed either air, 100% O(2) (NBO), or 100% O(2) at 3 bar (HBO) for 1 hour. Immediately thereafter, recombinant tissue plasminogen activator (rt-PA, 9 mg/kg) was injected. Although significant reperfusion was observed after thrombolysis in TT-tMCAO, vascular occlusion persisted in CT-tMCAO. In TT-tMCAO, NBO and HBO significantly reduced diffusion-weighted imaging-magnetic resonance imaging (MRI) lesion volume and postischemic blood-brain barrier (BBB) permeability on postcontrast T1-weighted images. NBO and, significantly more potently, HBO reduced macroscopic hemorrhage on T2* MRI and on corresponding postmortem cryosections. Oxygen therapy lowered hemoglobin content and attenuated activation of matrix metalloproteinases in the ischemic hemisphere. In contrast, NBO and HBO failed to reduce infarct size in CT but both decreased BBB damage and microscopic hemorrhagic transformation. Only HBO reduced hemoglobin extravasation in the ischemic hemisphere. In conclusion, NBO and HBO decrease infarct size after thromboembolic ischemia only if recanalization is successful. As NBO and HBO also reduce postthrombolytic intracerebral hemorrhage, combining the two with thrombolysis seems promising.

Physical exercise induces expression of CD31 and facilitates neural function recovery in rats with focal cerebral infarction.

PubMed

Hu, Xiquan; Zheng, Haiqing; Yan, Tiebin; Pan, Sanqiang; Fang, Jie; Jiang, Ruishu; Ma, Shangfeng

2010-05-01

The present study was aimed at examining the role of physical exercise in the improvement of damaged neural function and the induction of angiogenesis. An infarction model was induced by ligating the left middle cerebral artery occlusion (MCAO) in a total of 66 adult Sprague-Dawley rats that were further randomly divided into three groups: the physical exercise group (n=30), which was given running wheel exercise every day after MCAO, the control group (n=30) and sham-operated group (n=6), which were fed in standard cages without any special training exercise. The rats were killed on the third, seventh and fourteenth days and the neurological severity scores were examined for evaluating the neural function. And the neogenetic microvessels around the peri-infarction region were checked with the specific marker CD31. Although neogenetic microvessels in the peri-infarction region were observed in both control group and physical exercise group, which showed the highest signal on the seventh day after ischemia, the number of CD31 positive cells significantly increased in physical exercise group in comparison with those in control group on the seventh and fourteenth days after ischemia (p<0.01). Moreover, the neurological severity scores in the physical exercise group showed more quick declination as compared to those in control group from the seventh day after ischemic. Our results suggested that physical exercise plays an important role in the recovery of damaged neural function and induction of angiogenesis after cerebral infarction in rats.

Ebselen attenuates oxidative DNA damage and enhances its repair activity in the thalamus after focal cortical infarction in hypertensive rats.

PubMed

He, Meixia; Xing, Shihui; Yang, Bo; Zhao, Liqun; Hua, Haiying; Liang, Zhijian; Zhou, Wenliang; Zeng, Jinsheng; Pei, Zhong

2007-11-21

Oxidative DNA damage has been proposed to be a major contributor to focal cerebral ischemic injury. However, little is known about the role of oxidative DNA damage in remote damage secondary to the primary infarction. In the present study, we investigated oxidative damage within the ventroposterior nucleus (VPN) after distal middle cerebral artery occlusion (MCAO) in hypertensive rats. We also examined the possible protective effect of ebselen, one glutathione peroxidase mimic, on delayed degeneration in the VPN after distal MCAO. Neuronal damage in the ipsilateral VPN was examined by Nissl staining. Oxidative DNA damage and base repair enzyme activity were assessed by analyzing immunoreactivity of 8-hydroxy-2'-deoxyguanosine (8-ohdG) and 8-oxoguanine DNA glycosylase (OGG1), respectively. The number of intact neurons in the ipsilateral VPN decreased by 52% compared to the contralateral side in ischemia group 2 weeks after distal cerebral cortical infarction. The immunoreactivity of 8-ohdG significantly increased while OGG1 immunoreactivity significantly decreased in the ipsilateral VPN 2 weeks after distal cortical infarction (all p<0.01). Compared with vehicle treatment, ebselen significantly attenuated the neuron loss, ameliorated ischemia-induced increase in 8-ohdG level as well as decrease in OGG1 level within the ipsilateral VPN (all p<0.01). OGG1 was further demonstrated to mainly express in neurons. These findings strongly suggest that oxidative DNA damage may be involved in the delayed neuronal death in the VPN region following distal MCAO. Furthermore, ebselen protects against the delayed damage in the VPN when given at 24 h following distal MCAO.

Dynamic change of collateral flow varying with distribution of regional blood flow in acute ischemic rat cortex

NASA Astrophysics Data System (ADS)

Wang, Zhen; Luo, Weihua; Zhou, Fangyuan; Li, Pengcheng; Luo, Qingming

2012-12-01

Cerebral blood flow (CBF) is critical for the maintenance of cerebral function by guaranteed constant oxygen and glucose supply to brain. Collateral channels (CCs) are recruited to provide alternatives to CBF to ischemic regions once the primary vessel is occluded during ischemic stroke. However, the knowledge of the relationship between dynamic evolution of collateral flow and the distribution of regional blood flow remains limited. In this study, laser speckle imaging was used to assess dynamic changes of CCs and regional blood flow in a rat cortex with permanent middle cerebral artery occlusion (MCAo). We found that CCs immediately provided blood flow to ischemic territories after MCAo. More importantly, there were three kinds of dynamic changes of CCs during acute stroke: persistent CC, impermanent CC, and transient CC, respectively, related to different distributions of regional blood flow. Although there was the possible occurrence of peri-infarct depolarization (PID) during ischemia, there was no obvious significance about the onset time and duration of CCs between rats with and without PID. These results suggest that the initial arising of CCs does not ensure their persistence, and that collateral flow could be varied with distribution of regional blood flow in acute ischemic stroke, which may facilitate the understanding of collateral recruitment and promote the development of collateral therapeutics in the future.

Dynamic change of collateral flow varying with distribution of regional blood flow in acute ischemic rat cortex.

PubMed

Wang, Zhen; Luo, Weihua; Zhou, Fangyuan; Li, Pengcheng; Luo, Qingming

2012-12-01

Cerebral blood flow (CBF) is critical for the maintenance of cerebral function by guaranteed constant oxygen and glucose supply to brain. Collateral channels (CCs) are recruited to provide alternatives to CBF to ischemic regions once the primary vessel is occluded during ischemic stroke. However, the knowledge of the relationship between dynamic evolution of collateral flow and the distribution of regional blood flow remains limited. In this study, laser speckle imaging was used to assess dynamic changes of CCs and regional blood flow in a rat cortex with permanent middle cerebral artery occlusion (MCAo). We found that CCs immediately provided blood flow to ischemic territories after MCAo. More importantly, there were three kinds of dynamic changes of CCs during acute stroke: persistent CC, impermanent CC, and transient CC, respectively, related to different distributions of regional blood flow. Although there was the possible occurrence of peri-infarct depolarization (PID) during ischemia, there was no obvious significance about the onset time and duration of CCs between rats with and without PID. These results suggest that the initial arising of CCs does not ensure their persistence, and that collateral flow could be varied with distribution of regional blood flow in acute ischemic stroke, which may facilitate the understanding of collateral recruitment and promote the development of collateral therapeutics in the future.

In-Depth Proteomic Analysis of the Hippocampus in a Rat Model after Cerebral Ischaemic Injury and Repair by Danhong Injection (DHI)

PubMed Central

Cui, Yiran; Liu, Xin; Li, Xianyu; Yang, Hongjun

2017-01-01

Stroke is the second most common cause of death worldwide. A systematic description and characterization of the strokes and the effects induced in the hippocampus have not been performed so far. Here, we analysed the protein expression in the hippocampus 24 h after cerebral ischaemic injury and repair. Drug intervention using Danhong injection (DHI), which has been reported to have good therapeutic effects in a clinical setting, was selected for our study of cerebral ischaemia repair in rat models. A larger proteome dataset and total 4091 unique proteins were confidently identified in three biological replicates by combining tissue extraction for rat hippocampus and LC-MS/MS analysis. A label-free approach was then used to quantify the differences among the four experimental groups (Naive, Sham, middle cerebral artery occlusion (MCAO) and MCAO + DHI groups) and showed that about 2500 proteins on average were quantified in each of the experiment group. Bioinformatics analysis revealed that in total 280 unique proteins identified above were differentially expressed (P < 0.05). By combining the subcellular localization, hierarchical clustering and pathway information with the results from injury and repair phase, 12 significant expressed proteins were chosen and verified with respect to their potential as candidates for cerebral ischaemic injury by Western blot. The primary three signalling pathways of the candidates related may be involved in molecular mechanisms related to cerebral ischaemic injury. In addition, a glycogen synthase kinase-3β (Gsk-3β) inhibitor of the candidates with the best corresponding expression trends between western blotting (WB) and label-free quantitative results were chosen for further validation. The results of Western blot analysis of protein expression and 2,3,5- chloride three phenyl tetrazole (TTC) staining of rat brains showed that DHI treatment and Gsk-3β inhibitor are both able to confer protection against ischaemic injury in rat

Neuroprotective effect of 4-methylcyclopentadecanone on focal cerebral ischemia/reperfusion injury in rats.

PubMed

Ma, Yukui; Li, Yue; Zhang, Chunxia; Zhou, Xiaomian; Wu, Yingliang

2014-01-01

The present study aimed to investigate the effect of 4-methylcyclopentadecanone (4-MCPC) on local cerebral ischemia-reperfusion and the possible mechanisms involved. For this purpose, the focal cerebral ischemia rat model was induced by middle cerebral artery occlusion (MCAO) for 2 h, and the rats were treated with 4-MCPC (4 or 8 mg·kg(-1), p.o.) just 0.5 h before reperfusion. The neurological deficit scores and the ischemic infarct volume were recorded 24 h after the MCAO. In addition, the number of apoptotic cells was measured by TUNEL assay, and the expression of apoptosis-regulatory proteins and the PI3K/Akt neuroprotective signaling pathway were investigated by western blotting. Our results indicated that 4-MCPC (4 or 8 mg·kg(-1)) remarkably alleviated cerebral I/R injury by decreasing infarct volume and neurological deficit scores. 4-MCPC also decreased the number of apoptotic cells, regulated the expression of Bcl-2 and Bax, and increased the ratio of Bcl-2/Bax. Further study revealed that 4-MCPC treatment also increased the level of p-Akt and p-GSK-3β. Wortmannin (PI3K inhibitor) markedly abolished the effects of 4-MCPC. Taken together, our results suggest that 4-MCPC protects against cerebral I/R injury through the inhibition of apoptosis, and this neuroprotective effect may be partly related to the activation of the PI3K/Akt signal pathway.

Adult responses to an ischemic stroke in a rat model of neonatal stress and morphine treatment.

PubMed

Hays, Sarah L; Valieva, Olga A; McPherson, Ronald J; Juul, Sandra E; Gleason, Christine A

2013-02-01

Critically ill newborn infants experience stressors that may alter brain development. Using a rodent model, we previously showed that neonatal stress, morphine, and stress plus morphine treatments each influence early gene expression and may impair neurodevelopment and learning behavior. We hypothesized that the combination of neonatal stress with morphine may alter neonatal angiogenesis and/or adult cerebral blood vessel density and thus increase injury after cerebral ischemia in adulthood. To test this, neonatal Lewis rats underwent 8 h/d maternal separation, plus morning/afternoon hypoxia exposure and either saline or morphine treatment (2 mg/kg s.c.) from postnatal day 3-7. A subset received bromodeoxyuridine to track angiogenesis. Adult brains were stained with collagen IV to quantify cerebral blood vessel density. To examine vulnerability to brain injury, postnatal day 80 adult rats underwent right middle cerebral artery occlusion (MCAO) to produce unilateral ischemic lesions. Brains were removed and processed for histology 48 h after injury. Brain injury was assessed by histological evaluation of hematoxylin and eosin, and silver staining. In contrast to our hypothesis, neither neonatal morphine, stress, nor the combination affected cerebral vessel density or MCAO-induced brain injury. Neonatal angiogenesis was not detected in adult rats possibly due to turnover of endothelial cells. Although unrelated to angiogenesis, hippocampal granule cell neurogenesis was detected and there was a trend (P = 0.073) toward increased bromodeoxyuridine incorporation in rats that underwent neonatal stress. These findings are discussed in contrast to other data concerning the effects of morphine on cerebrovascular function, and acute effects of morphine on hippocampal neurogenesis. Copyright © 2012 ISDN. Published by Elsevier Ltd. All rights reserved.

Down-regulated Na+/K+-ATPase activity in ischemic penumbra after focal cerebral ischemia/reperfusion in rats

PubMed Central

Huang, Hao; Chen, Yang-Mei; Zhu, Fei; Tang, Shi-Ting; Xiao, Ji-Dong; Li, Lv-Li; Lin, Xin-Jing

2015-01-01

This study was aimed to examine whether the Na+/K+ adenosine triphosphatase (Na+/K+-ATPase) activity in ischemic penumbra is associated with the pathogenesis of ischemia/reperfusion-induced brain injury. An experimental model of cerebral ischemia/reperfusion was made by transient middle cerebral artery occlusion (tMCAO) in rats and the changes of Na+/K+-ATPase activity in the ischemic penumbra was examined by Enzyme Assay Kit. Extensive infarction was observed in the frontal and parietal cortical and subcortical areas at 6 h, 24 h, 48 h, 3 d and 7 d after tMCAO. Enzyme Assay analyses revealed the activity of Na+/K+-ATPase was decreased in the ischemic penumbra of model rats after focal cerebral ischemia/reperfusion compared with sham-operated rats, and reduced to its minimum at 48 h, while the infarct volume was enlarged gradually. In addition, accompanied by increased brain water content, apoptosis-related bcl-2 and Bax proteins, apoptotic index and neurologic deficits Longa scores, but fluctuated the ratio of bcl-2/Bax. Correlation analysis showed that the infarct volume, apoptotic index, neurologic deficits Longa scores and brain water content were negatively related with Na+/K+-ATPase activity, while the ratio of bcl-2/Bax was positively related with Na+/K+-ATPase activity. Our results suggest that down-regulated Na+/K+-ATPase activity in ischemic penumbra might be involved in the pathogenesis of cerebral ischemia/reperfusion injury presumably through the imbalance ratio of bcl-2/Bax and neuronal apoptosis, and identify novel target for neuroprotective therapeutic intervention in cerebral ischemic disease. PMID:26722460

A novel animal model of dysphagia following stroke.

PubMed

Sugiyama, Naoto; Nishiyama, Eiji; Nishikawa, Yukitoshi; Sasamura, Takashi; Nakade, Shinji; Okawa, Katsumasa; Nagasawa, Tadashi; Yuki, Akane

2014-02-01

Patients who have an ischemic stroke are at high risk of swallowing disorders. Aspiration due to swallowing disorders, specifically delayed trigger of the pharyngeal stage of swallowing, predisposes such patients to pneumonia. In the present study, we evaluated swallowing reflex in a rat model of transient middle cerebral artery occlusion (tMCAO), which is one of the most common experimental animal models of cerebral ischemia, in order to develop a novel animal model of dysphagia following ischemic stroke. A swallowing reflex was elicited by a 10-s infusion of distilled water (DW) to the pharyngolaryngeal region in the tMCAO rat model. Swallowing reflex was estimated using the electromyographic activity of the mylohyoid muscle from 1 to 3 weeks after surgery. Two weeks after tMCAO, the number of swallows significantly decreased and the onset latency of the first swallow was prolonged compared with that of the sham group. The number of swallows in rats significantly increased by infusions of 10 mM citric acid and 0.6 μM capsaicin to the pharyngolaryngeal region compared with the number from infusion of DW. It has been reported that sensory stimulation of the pharyngolaryngeal region with citric acid, capsaicin, and L-menthol ameliorates hypofunction of pharyngeal-stage swallowing in dysphagia patients. Therefore, the tMCAO rat model may show some of the symptoms of pharyngeal-stage swallowing disorders, similar to those in patients with ischemic stroke. This rat tMCAO model has the potential to become a novel animal model of dysphagia following stroke that is useful for development of therapeutic methods and drugs.

Mesenchymal stem cells derived from peripheral blood protects against ischemia.

PubMed

Ukai, Ryo; Honmou, Osamu; Harada, Kuniaki; Houkin, Kiyohiro; Hamada, Hirofumi; Kocsis, Jeffery D

2007-03-01

Intravenous delivery of mesenchymal stem cells (MSCs) prepared from bone marrow (BMSCs) reduces infarction volume and ameliorates functional deficits in a rat cerebral ischemia model. MSC-like multipotent precursor cells (PMSCs) have also been suggested to exist in peripheral blood. To test the hypothesis that treatment with PMSCs may have a therapeutic benefit in stroke, we compared the efficacy of systemic delivery of BMSCs and PMSCs. A permanent middle cerebral artery occlusion (MCAO) in rat was induced by intraluminal vascular occlusion with a microfilament. Rat BMSCs and PMSCs were prepared in culture and intravenously injected into the rats 6 h after MCAO. Lesion size was assessed at 6 h, and 1, 3, and 7 days using MR imaging and histology. The hemodynamic change of cerebral blood perfusion on stroke was assessed the same times using perfusion-weighted image (PWI). Functional outcome was assessed using the treadmill stress test. Both BMSCs and PMSCs treated groups had reduced lesion volume, improved regional cerebral blood flow, and functional improvement compared to the control group. The therapeutic benefits of both MSC-treated groups were similar. These data suggest that PMSCs derived from peripheral blood could be an important cell source of cell therapy for stroke.

[Changes in DNA repair enzymes in rat ventroposterior nucleus of the thalamus after cerebral cortex infarction].

PubMed

He, Mei-Xia; Zeng, Jin-Sheng; Hua, Hai-Ying; Xing, Shi-Hui; Ba, Yun-Peng

2010-10-01

To investigate the damage within the ventroposterior nucleus (VPN) of the thalamus after focal cortical infarction and its mechanism, and explore the effect of ebselen on the oxidative damage after cerebral cortex infarction in hypertensive rats. Middle cerebral artery occlusion (MCAO) was induced in stroke-prone renovascular hypertensive rats (RHRSP), and the rats were divided into four groups by table of random number: sham operation group, model group, vehicle group and ebselen group, each group consisted of 8 rats. In animals subjected to sham surgery the middle cerebral artery was exposed only. Ebselen (5 ml/kg) or vehicle (a mixed solvent consisting of 0.5% carboxymethyl cellulose and 0.02% Tween 20, 5 ml/kg) was given by gastric gavage starting 24 hours after cerebral cortical infarction. Two weeks after the MCAO, the rats were sacrificed, and VPN from each group was sectioned and stained with hematoxylin-eosin (HE), and apurinic/apyrimidinic endonuclease (APE) and Escherichia coli MutY DNA glycosylase (MYH) were determined by immunohistochemistry. HE staining showed that ebselen ameliorated the VPN damage induced by ischemia. Immunohistochemical imaging analysis revealed a distinct nuclear staining of APE and nuclear and cytoplasm distribution of MYH in the entire region of the VPN. Compared with sham operation group, the number of APE and MYH positive cells decreased in model group and vehicle group (APE: 57.0±14.7, 49.4±12.5 vs. 101.0±13.6, MYH: 15.0±4.7, 10.4±2.5 vs. 56.0±13.2, all P<0.05). Compared with model group and vehicle group, the number of APE and MYH positive cells increased significantly in ebselen group (APE: 72.2±7.6 vs. 57.0±14.7, 49.4±12.5, MYH: 32.2±7.6 vs. 15.0±4.7, 10.4±2.5, all P<0.05); the difference of the number of APE and MYH positive cells between model group and vehicle group showed no statistical significance. After 2 weeks of MCAO, there is a marked decrease of APE and MYH in VPN; ebselen can obviously increase the

A free radical scavenger edaravone suppresses systemic inflammatory responses in a rat transient focal ischemia model.

PubMed

Fujiwara, Norio; Som, Angel T; Pham, Loc-Duyen D; Lee, Brian J; Mandeville, Emiri T; Lo, Eng H; Arai, Ken

2016-10-28

A free radical scavenger edaravone is clinically used in Japan for acute stroke, and several basic researches have carefully examined the mechanisms of edaravone's protective effects. However, its actions on pro-inflammatory responses under stroke are still understudied. In this study, we subjected adult male Sprague-Dawley rats to 90-min middle cerebral artery (MCA) occlusion followed by reperfusion. Edaravone was treated twice via tail vein; after MCA occlusion and after reperfusion. As expected, edaravone-treated group showed less infarct volume and edema formation compared with control group at 24-h after an ischemic onset. Furthermore, edaravone reduced the levels of plasma interleukin (IL)-1β and matrix metalloproteinase-9 at 3-h after ischemic onset. Several molecules besides IL-1β and MMP-9 are involved in inflammatory responses under stroke conditions. Therefore, we also examined whether edaravone treatment could decrease a wide range of pro-inflammatory cytokines/chemokines by testing rat plasma samples with a rat cytokine array. MCAO rats showed elevations in plasma levels of CINC-1, Fractalkine, IL-1α, IL-1ra, IL-6, IL-10, IP-10, MIG, MIP-1α, and MIP-3α, and all these increases were reduced by edaravone treatment. These data suggest that free radical scavengers may reduce systemic inflammatory responses under acute stroke conditions, and therefore, oxidative stress can be still a viable target for acute stroke therapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Normobaric hyperoxia retards the evolution of ischemic brain tissue toward infarction in a rat model of transient focal cerebral ischemia.

PubMed

Xu, Ji; Zhang, Yuan; Liang, Zhouyuan; Wang, Ting; Li, Weiping; Ren, Lijie; Huang, Shaonong; Liu, Wenlan

2016-01-01

Oxygen therapy has been long considered a logical therapy for ischemic stroke. Our previous studies showed that normobaric hyperoxia (normobaric hyperoxia (NBO), 95% O2 with 5% CO2) treatment during ischemia reduced ischemic neuronal death and cerebromicrovascular injury in animal stroke models. In this study, we studied the effects of NBO on the evolution of ischemic brain tissue to infarction in a rat model of transient focal cerebral ischemia. Male Sprague-Dawley rats were given NBO (95% O2) or normoxia (21% O2) during 90-min filament occlusion of the middle cerebral artery (MCAO), followed by 3 or 22.5 h of reperfusion. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to evaluate the longitudinal evolution of tissue infarction. Results： In normoxic rats, MCA-supplied cortical and striatal tissue was infarcted after 90-min MCAO with 22.5 h of reperfusion. NBO-treated rats showed a 61.4% reduction in infarct size and tissue infarction mainly occurred in the ischemic striatum. When infarction was assessed at an earlier time point, i.e. at 3 h of reperfusion, normoxic rats showed significantly smaller but mature infarction (no TTC staining, white color), with the infarction mainly occurring in the striatum. Unexpectedly, NBO-treated rats only showed immature lesion (partially stained by TTC, light white color) in the ischemic striatum, indicating that NBO treatment also retarded the process of neuronal death in the ischemic core. Of note, NBO-preserved striatal tissue underwent infarction after prolonged reperfusion. Conclusions： Our results demonstrate that NBO treatment given during cerebral ischemia retards the evolution of ischemic brain tissue toward infarction and NBO-preserved cortical tissue survives better than NBO-preserved striatal tissue during the phase of reperfusion.

[Effect of ginsenoside Rb1 on cerebral infarction volume and IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion injury model rats].

PubMed

Liu, Jun-Wei; Ren, Ye-Long; Liu, Xu-Ling; Xia, Hong-Lian; Zhang, Hui-Ling; Jin, Shen-Hui; Dai, Qin-Xue; Wang, Jun-Lu

2013-12-01

To investigate the effect of ginsenoside Rb1 on cerebral infarction volume as well as IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion (I/R) injury model rats. The I/R rat model was established by using thread according to Zea-Longa. SD rats were randomly divided into five groups, i.e., the sham-operation group, the model group, the low dose ginsenoside Rb1 (20 mg/kg) group, the medium dose ginsenoside Rb1 group (40 mg/kg), and the high dose ginsenoside Rb1 group (80 mg/kg), 12 in each group. Rats in the sham-operation group only received middle cerebral artery occlusion (MCAO) but without thread insertion. The MCAO model was prepared in the rest 4 groups, followed by MCAO2 h later. Ginsenoside Rb1 at each dose was peritoneally administrated to rats in corresponding groups immediately after cerebral ischemia. Equal volume of normal saline was administered to rats in the sham-operation group. Rats' cerebral infarction volume, integrals of neurologic defect degree, expression of IL-1 beta content in the brain tissue and sera were observed 24 h after 2-h cerebral I/R. In the model group, integrals of neurologic defect degree were improved (P < 0.01), IL-1 beta positive cells in the brain tissue increased and serum IL-1 beta content elevated (P < 0.05), when compared with the sham-operation group. In comparison of the model group, integrals of neurologic defect degree were lowered in the medium dose and high dose ginsenoside Rb1 groups (P < 0.05, P < 0.01). The cerebral infarction volume was all shrunken in each ginsenoside Rb1 group, IL-1 beta positive cells in the brain tissue decreased, and IL-1 beta content in serum reduced (P < 0.01, P < 0.05). Compared with the low dose ginsenoside Rb1 group, integrals of neurologic defect degree decreased, the cerebral infarction volume shrunken, and IL-1 beta content in serum reduced in the high dose ginsenoside Rb1 group (P < 0.01, P < 0.05). Ginsenoside Rb1 (20, 40, 80 mg/kg) might effectively

Pharmacologically increasing collateral perfusion during acute stroke using a carboxyhemoglobin gas transfer agent (Sanguinate™) in spontaneously hypertensive rats.

PubMed

Cipolla, Marilyn J; Linfante, Italo; Abuchowski, Abe; Jubin, Ronald; Chan, Siu-Lung

2018-05-01

Similar to patients with chronic hypertension, spontaneously hypertensive rats (SHR) develop fast core progression during middle cerebral artery occlusion (MCAO) resulting in large final infarct volumes. We investigated the effect of Sanguinate™ (SG), a PEGylated carboxyhemoglobin (COHb) gas transfer agent, on changes in collateral and reperfusion cerebral blood flow and brain injury in SHR during 2 h of MCAO. SG (8 mL/kg) or vehicle ( n = 6-8/group) was infused i.v. after 30 or 90 min of ischemia with 2 h reperfusion. Multi-site laser Doppler probes simultaneously measured changes in core MCA and collateral flow during ischemia and reperfusion using a validated method. Brain injury was measured using TTC. Animals were anesthetized with choral hydrate. Collateral flow changed little in vehicle-treated SHR during ischemia (-8 ± 9% vs. prior to infusion) whereas flow increased in SG-treated animals (29 ± 10%; p < 0.05). In addition, SG improved reperfusion regardless of time of treatment; however, brain injury was smaller only with early treatment in SHR vs. vehicle (28.8 ± 3.2% vs. 18.8 ± 2.3%; p < 0.05). Limited collateral flow in SHR during MCAO is consistent with small penumbra and large infarction. The ability to increase collateral flow in SHR with SG suggests that this compound may be useful as an adjunct to endovascular therapy and extend the time window for treatment.

Beneficial effect of agmatine on brain apoptosis, astrogliosis, and edema after rat transient cerebral ischemia

PubMed Central

2010-01-01

Background Although agmatine therapy in a mouse model of transient focal cerebral ischemia is highly protective against neurological injury, the mechanisms underlying the protective effects of agmatine are not fully elucidated. This study aimed to investigate the effects of agmatine on brain apoptosis, astrogliosis and edema in the rats with transient cerebral ischemia. Methods Following surgical induction of middle cerebral artery occlusion (MCAO) for 90 min, agmatine (100 mg/kg, i.p.) was injected 5 min after beginning of reperfusion and again once daily for the next 3 post-operative days. Four days after reperfusion, both motor and proprioception functions were assessed and then all rats were sacrificed for determination of brain infarct volume (2, 3, 5-triphenyltetrazolium chloride staining), apoptosis (TUNEL staining), edema (both cerebral water content and amounts of aquaporin-4 positive cells), gliosis (glial fibrillary acidic protein [GFAP]-positive cells), and neurotoxicity (inducible nitric oxide synthase [iNOS] expression). Results The results showed that agmatine treatment was found to accelerate recovery of motor (from 55 degrees to 62 degrees) and proprioception (from 54% maximal possible effect to 10% maximal possible effect) deficits and to prevent brain infarction (from 370 mm3 to 50 mm3), gliosis (from 80 GFAP-positive cells to 30 GFAP-positive cells), edema (cerebral water contents decreased from 82.5% to 79.4%; AQP4 positive cells decreased from 140 to 84 per section), apoptosis (neuronal apoptotic cells decreased from 100 to 20 per section), and neurotoxicity (iNOS expression cells decreased from 64 to 7 per section) during MCAO ischemic injury in rats. Conclusions The data suggest that agmatine may improve outcomes of transient cerebral ischemia in rats by reducing brain apoptosis, astrogliosis and edema. PMID:20815926

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

NASA Astrophysics Data System (ADS)

Kawauchi, Satoko; Nishidate, Izumi; Nawashiro, Hiroshi; Sato, Shunichi

2014-03-01

To understand the pathophysiology of ischemic stroke, in vivo imaging of the brain tissue viability and related spreading depolarization is crucial. In the infarct core, impairment of energy metabolism causes anoxic depolarization (AD), which considerably increases energy consumption, accelerating irreversible neuronal damage. In the peri-infarct penumbra region, where tissue is still reversible despite limited blood flow, peri-infarct depolarization (PID) occurs, exacerbating energy deficit and hence expanding the infarct area. We previously showed that light-scattering signal, which is sensitive to cellular/subcellular structural integrity, was correlated with AD and brain tissue viability in a rat hypoxia-reoxygenation model. In the present study, we performed transcranial NIR diffuse reflectance imaging of the rat brain during middle cerebral artery (MCA) occlusion and examined whether the infarct core and PIDs can be detected. Immediately after occluding the left MCA, light scattering started to increase focally in the occlusion site and a bright region was generated near the occlusion site and spread over the left entire cortex, which was followed by a dark region, showing the occurrence of PID. The PID was generated repetitively and the number of times of occurrence in a rat ranged from four to ten within 1 hour after occlusion (n=4). The scattering increase in the occlusion site was irreversible and the area with increased scattering expanded with increasing the number of PIDs, indicating an expansion of the infarct core. These results suggest the usefulness of NIR diffuse reflectance signal to visualize spatiotemporal changes in the infarct area and PIDs.

GSK-3β inhibitors suppressed neuroinflammation in rat cortex by activating autophagy in ischemic brain injury.

PubMed

Zhou, Xiaogang; Zhou, Jian; Li, Xilei; Guo, Chang'an; Fang, Taolin; Chen, Zhengrong

2011-07-29

Previous studies have shown that GSK-3β inhibitor could reduce infarct volume after ischemia brain injury. However, the underlying mechanisms of GSK-3β inhibitor involving neuroprotection remain poorly understood. In the present study, we demonstrated that GSK-3β inhibitor suppressed insult-induced neuroinflammation in rat cortex by increasing autophagy activation in ischemic injury. Male rats were subjected to pMCAO (permanent middle cerebral artery occlusion) followed by treating with SB216763, a GSK-3β inhibitor. We found that insult-induced inflammatory response was significantly decreased by intraperitoneal infusion of SB216763 in rat cortex. A higher level of autophagy was also detected after SB216763 treatment. In the cultured primary microglia, SB216763 activated autophagy and suppressed inflammatory response. Importantly, inhibition of autophagy by Beclin1-siRNA increased inflammatory response in the SB216763-treated microglia. These data suggest that GSK-3β inhibitor suppressed neuroinflammation by activating autophagy after ischemic brain injury, thus offering a new target for prevention of ischemic brain injury. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of electroacupuncture on the expression of interlukin-1beta mRNA after transient focal cerebral ischemia.

PubMed

Xu, Zhen-Feng; Wu, Gen-Cheng; Cao, Xiao-Ding

2002-01-01

It has been reported that interleukin-1beta (IL-1beta ) play a key role in the pathogenesis of cerebral ischemia. Acupuncture is an effective traditional medical therapy in China. The aim of present study was to evaluate the effect of electroacupuncture (EA) on IL-1beta mRNA expression after middle cerebral artery occlusion (MCAO) in rats. Using in situ hybridization technique, it was found that in the MCAO group the expression of IL-1beta mRNA was significantly increased at 2h, 6h, 12h after reperfusion in cerebral ischemic cortex compared with normal group. In EA+ MCAO group the expression of IL-1beta mRNA was significantly decreased at 2h, 6h and 12h in ischemic cortex compared with MCAO group. The results indicated that EA might decrease the IL-1beta protein expression by reducing the IL-beta mRNA expression in ischemic cortex.

Neuroprotective effects of bisperoxovanadium on cerebral ischemia by inflammation inhibition.

PubMed

Mao, Lun-Lin; Hao, Dong-Lin; Mao, Xiao-Wei; Xu, Yuan-Feng; Huang, Ting-Ting; Wu, Bo-Na; Wang, Li-Hui

2015-08-18

PTEN is a dual specificity phosphatase and is implicated in inflammation and apoptosis of cerebral ischemia and reperfusion (I/R) injury. Bisperoxovanadium (Bpv), a specific inhibitor of PTEN's phosphatase activity, has demonstrated powerful neuroprotective properties. We investigated the neuroprotective roles of Bpv in the rat model of middle cerebral artery occlusion (MCAO) cerebral I/R injury, and explored the modulation of inflammatory mediators and PI3K/Akt/GSK-3β pathways by Bpv. Our results showed that treatment with Bpv (0.2 mg/kg/day) significantly decreased neurological deficit scores at 7 days after MCAO and infarct volume at 4 days after MCAO. The IL-10 concentration was increased and TNF-α concentration was decreased in the ischemic boundary zone of the cerebral cortex at 4 days after MCAO by Bpv. Furthermore, Bpv (0.2 mg/kg/day) treatment significantly reduced PTEN mRNA and protein levels and increased PI3K, Akt and p-GSK-3β proteins expression in the ischemic boundary zone of the cerebral cortex at 4 days after MCAO. In conclusions, Bpv treatment demonstrates neuroprotective effects on cerebral ischemia and reperfusion injury of ischemic stroke rats and is associated with its modulation of inflammatory mediator production and up-regulation of PTEN downstream proteins PI3K, Akt and p-GSK-3β. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Calibrations for a MCAO Imaging System

NASA Astrophysics Data System (ADS)

Hibon, Pascale; B. Neichel; V. Garrel; R. Carrasco

2017-09-01

"GeMS, the Gemini Multi conjugate adaptive optics System installed at the Gemini South telescope (Cerro Pachon, Chile) started to deliver science since the beginning of 2013. GeMS is using the Multi Conjugate AdaptiveOptics (MCAO) technique allowing to dramatically increase the corrected field of view (FOV) compared to classical Single Conjugated Adaptive Optics (SCAO) systems. It is the first sodium-based multi-Laser Guide Star (LGS) adaptive optics system. It has been designed to feed two science instruments: GSAOI, a 4k×4k NIR imager covering 85"×85" with 0.02" pixel scale, and Flamingos-2, a NIR multi-object spectrograph. We present here an overview of the calibrations necessary for reducing and analysing the science datasets obtained with GeMS+GSAOI."

Ferulic acid attenuates the cerebral ischemic injury-induced decrease in peroxiredoxin-2 and thioredoxin expression.

PubMed

Sung, Jin-Hee; Gim, Sang-Ah; Koh, Phil-Ok

2014-04-30

Ferulic acid, a phenolic phytochemical compound found in various plants, has a neuroprotective effect through its anti-oxidant and anti-inflammation functions. Peroxiredoxin-2 and thioredoxin play a potent neuroprotective function against oxidative stress. We investigated whether ferulic acid regulates peroxiredoxin-2 and thioredoxin levels in cerebral ischemia. Sprague-Dawley rats (male, 210-230g) were treated with vehicle or ferulic acid (100mg/kg) after middle cerebral artery occlusion (MCAO), and cerebral cortex tissues were collected 24h after MCAO. Decreases in peroxiredoxin-2 and thioredoxin levels were elucidated in MCAO-operated animals using a proteomics approach. We found that ferulic acid treatment prevented the MCAO-induced decrease in the expression of peroxiredoxin-2 and thioredoxin. RT-PCR and Western blot analyses confirmed that ferulic acid treatment attenuated the MCAO-induced decrease in peroxiredoxin-2 and thioredoxin levels. Moreover, immunoprecipitation analysis showed that the interaction between thioredoxin and apoptosis signal-regulating kinase 1 (ASK1) decreased during MCAO, whereas ferulic acid prevented the MCAO-induced decrease in this interaction. Our findings suggest that ferulic acid plays a neuroprotective role by attenuating injury-induced decreases in peroxiredoxin-2 and thioredoxin levels in neuronal cell injury. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Electroacupunctre improves motor impairment via inhibition of microglia-mediated neuroinflammation in the sensorimotor cortex after ischemic stroke.

PubMed

Liu, Weilin; Wang, Xian; Yang, Shanli; Huang, Jia; Xue, Xiehua; Zheng, Yi; Shang, Guanhao; Tao, Jing; Chen, Lidian

2016-04-15

Electroacupuncture (EA) is one of the safety and effective therapies for improving neurological and sensorimotor impairment via blockade of inappropriate inflammatory responses. However, the mechanisms of anti-inflammation involved is far from been fully elucidated. Focal cerebral ischemic stroke was administered by the middle cerebral artery occlusion and reperfusion (MCAO/R) surgery. The MCAO/R rats were accepted EA treatment at the LI 11 and ST 36 acupoints for consecutive 3days. The neurological outcome, animal behaviors test and molecular biology assays were used to evaluate the MCAO/R model and therapeutic effect of EA. EA treatment for MCAO rats showed a significant reduction in the infarct volumes accompanied by functional recovery in mNSS outcomes, motor function performances. The possible mechanisms that EA treatment attenuated the over-activation of Iba-1 and ED1 positive microglia in the peri-infract sensorimotor cortex. Simultaneously, both tissue and serum protein levels of the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were decreased by EA treatment in MCAO/R injured rats. The levels of inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) were decreased in the peri-infract sensorimotor cortex and blood serum of MCAO/R injured rats after EA treatment. Furthermore, we found that EA treatment prevented from the nucleus translocation of NF-κB p65 and suppressed the expression of p38 mitogen-activated protein kinase (p38 MAPK) and myeloid differentiation factor 88 (MyD88) in the peri-infract sensorimotor cortex. The findings from this study indicated that EA improved the motor impairment via inhibition of microglia-mediated neuroinflammation that invoked NF-κB p65, p38 MAPK and MyD88 produced proinflammatory cytokine in the peri-infract sensorimotor cortex of rats following ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Perillaldehyde attenuates cerebral ischemia-reperfusion injury-triggered overexpression of inflammatory cytokines via modulating Akt/JNK pathway in the rat brain cortex.

PubMed

Xu, Lixing; Li, Yuebi; Fu, Qiang; Ma, Shiping

2014-11-07

Perillaldehyde (PAH), one of the major oil components in Perilla frutescens, has anti-inflammatory effects. Few studies have examined the neuroprotective effect of PAH on stroke. So the aim of our study is to investigate the effect of PAH on ischemia-reperfusion-induced injury in the rat brain cortex. Middle cerebral artery occlusion (MCAO) model was selected to make cerebral ischemia-reperfusion injury. Rats were assigned randomly to groups of sham, MCAO, and two treatment groups by PAH at 36.0, 72.0mg/kg. Disease model was set up after intragastrically (i.g.) administering for 7 consecutive days. The neurological deficit, the cerebral infarct size, biochemical parameters and the relative mRNA and protein levels were examined. The results showed that the NO level, the iNOS activity, the neurological deficit scores, the cerebral infarct size and the expression of inflammatory cytokines including interleukin (IL)-1β, interleukin (IL)-6 and tumor necrosis factor (TNF)-α were significantly decreased by PAH treatment. PAH also increased the Phospho-Akt level and decrease the Phospho-JNK level by Western blot analysis. Meanwhile, the PAH groups exhibited a dramatically decrease of apoptosis-related mRNA expression such as Bax and caspase-3. Our findings shown that PAH attenuates cerebral ischemia/reperfusion injury in the rat brain cortex, and suggest its neuroprotective effect is relate to regulating the inflammatory response through Akt /JNK pathway. The activation of this signalling pathway eventually inhibits apoptotic cell death induced by cerebral ischemia-reperfusion. Copyright © 2014 Elsevier Inc. All rights reserved.

5'-adenosine monophosphate-induced hypothermia attenuates brain ischemia/reperfusion injury in a rat model by inhibiting the inflammatory response.

PubMed

Miao, Yi-Feng; Wu, Hui; Yang, Shao-Feng; Dai, Jiong; Qiu, Yong-Ming; Tao, Zhen-Yi; Zhang, Xiao-Hua

2015-01-01

Hypothermia treatment is a promising therapeutic strategy for brain injury. We previously demonstrated that 5'-adenosine monophosphate (5'-AMP), a ribonucleic acid nucleotide, produces reversible deep hypothermia in rats when the ambient temperature is appropriately controlled. Thus, we hypothesized that 5'-AMP-induced hypothermia (AIH) may attenuate brain ischemia/reperfusion injury. Transient cerebral ischemia was induced by using the middle cerebral artery occlusion (MCAO) model in rats. Rats that underwent AIH treatment exhibited a significant reduction in neutrophil elastase infiltration into neuronal cells and matrix metalloproteinase 9 (MMP-9), interleukin-1 receptor (IL-1R), tumor necrosis factor receptor (TNFR), and Toll-like receptor (TLR) protein expression in the infarcted area compared to euthermic controls. AIH treatment also decreased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling- (TUNEL-) positive neuronal cells. The overall infarct volume was significantly smaller in AIH-treated rats, and neurological function was improved. By contrast, rats with ischemic brain injury that were administered 5'-AMP without inducing hypothermia had ischemia/reperfusion injuries similar to those in euthermic controls. Thus, the neuroprotective effects of AIH were primarily related to hypothermia.

Licorice Pretreatment Protects Against Brain Damage Induced by Middle Cerebral Artery Occlusion in Mice.

PubMed

Lim, Chiyeon; Lim, Sehyun; Lee, Byoungho; Kim, Buyeo; Cho, Suin

2018-05-01

Licorice is extracted from the roots of plants in the Glycyrrhiza genus, especially Glycyrrhiza uralensis in China and Korea. It has several pharmacological activities, including neuro-protective, anti-fungal, and anti-cariogenic effects. Ischemia/reperfusion-induced brain injury is a leading cause of adult disability and death; thus, the identification of anti-apoptotic, neuro-protective therapeutic agents is viewed as an attractive drug development strategy. Infarct volumes and the expression of several apoptosis-related proteins, including Bcl-xL, Bcl-2, caspase-8, and caspase-9, were evaluated by western blotting in the brains of mice subjected to middle cerebral artery occlusion (MCAO). Three consecutive days of oral pretreatment with the methanol extract of licorice (GRex) significantly reduced infarct volumes 24 h after MCAO. In addition, GRex effectively inhibited the activation of caspase-9 by upregulating protein expression of Bcl-xL and Bcl-2. The neuro-protective effect of licorice was due to its regulation of apoptosis-related proteins. These data suggest that licorice could be a potential candidate for the treatment of ischemia-induced brain damage.

Niaspan increases axonal remodeling after stroke in type 1 diabetes rats✩

PubMed Central

Yan, Tao; Chopp, Michael; Ye, Xinchun; Liu, Zhongwu; Zacharek, Alex; Cui, Yisheng; Roberts, Cynthia; Buller, Ben; Chen, Jieli

2012-01-01

Background and objective We investigated axonal plasticity in the bilateral motor cortices and the long term therapeutic effect of Niaspan on axonal remodeling after stroke in type-1 diabetic (T1DM) rats. Experimental approaches T1DM was induced in young adult male Wistar rats via injection of streptozotocin. T1DM rats were subjected to 2 h transient middle cerebral artery occlusion (MCAo) and were treated with 40 mg/kg Niaspan or saline starting 24 h after MCAo and daily for 28 days. Anterograde tracing using biotinylated dextran amine (BDA) injected into the contralateral motor cortex was performed to assess axonal sprouting in the ipsilateral motor cortex area. Functional outcome, SMI-31 (a pan-axonal microfilament marker), Bielschowsky silver and synaptophysin expression were measured. In vitro studies using primary cortical neuron (PCN) cultures and in vivo BDA injection into the brain to anterogradely label axons and terminals were employed. Results Niaspan treatment of stroke in T1DM–MCAo rats significantly improved functional outcome after stroke and increased SMI-31, Bielschowsky silver and synaptophysin expression in the ischemic brain compared to saline treated T1DM–MCAo rats (p<0.05). Using BDA to anterograde label axons and terminals, Niaspan treatment significantly increased axonal density in ipsilateral motor cortex in T1DM–MCAo rats (p<0.05, n=7/group). Niacin treatment of PCN significantly increased Ang1 expression under high glucose condition. Niacin and Ang1 significantly increased neurite outgrowth, and anti-Ang1 antibody marginally attenuated Niacin induced neurite outgrowth (p=0.06, n=6/group) in cultured PCN under high glucose condition. Conclusion Niaspan treatment increased ischemic brain Ang1 expression and promoted axonal remodeling in the ischemic brain as well as improved functional outcome after stroke. Ang1 may partially contribute to Niaspan-induced axonal remodeling after stroke in T1DM-rats. PMID:22266016

MiR-133b promotes neural plasticity and functional recovery after treatment of stroke with multipotent mesenchymal stromal cells in rats via transfer of exosome-enriched extracellular particles

PubMed Central

Xin, Hongqi; Li, Yi; Liu, Zhongwu; Wang, Xinli; Shang, Xia; Cui, Yisheng; Zhang, Zheng Gang; Chopp, Michael

2013-01-01

To test, in vivo, the hypothesis that exosomes from multipotent mesenchymal stromal cells (MSCs) mediate microRNA 133b (miR-133b) transfer which promotes neurological recovery from stroke, we employed knock-in and knock-down technologies to up-regulate or down-regulate the miR-133b level in MSCs (miR-133b+MSCs or miR-133b−MSCs) and their corresponding exosomes, respectively. Rats were subjected to middle cerebral artery occlusion (MCAo) and were treated with naïve MSCs, miR-133b+MSCs, or miR-133b−MSC at one day after MCAo. Compared with controls, rats receiving naïve MSC treatment significantly improved functional recovery, and exhibited increased axonal plasticity and neurite remodeling in the ischemic boundary zone (IBZ) at day 14 after MCAo. The outcomes were significantly enhanced with miR-133b+MSC treatment, and were significantly decreased with miR-133b−MSC treatment, compared to naïve MSC treatment. The miR-133b level in exosomes collected from the cerebral spinal fluid was significantly increased after miR-133b+MSC treatment, and was significantly decreased after miR-133b−MSC treatment at day 14 after MCAo, compared to naïve MSC treatment. Tagging exosomes with green fluorescent protein demonstrated that exosomes-enriched extracellular particles were released from MSCs and transferred to adjacent astrocytes and neurons. The expression of selective targets for miR-133b, connective tissue growth factor and ras homolog gene family member A, were significantly decreased in the IBZ after miR-133b+MSC treatment, while their expression remained at similar elevated levels after miR-133b−MSC treatment, compared to naïve MSC treatment. Collectively, our data suggest that exosomes from MSCs mediate the miR-133b transfer to astrocytes and neurons, which regulate gene expression, subsequently benefit neurite remodeling and functional recovery after stroke. PMID:23630198

[18F]DPA-714 PET imaging shows immunomodulatory effect of intravenous administration of bone marrow stromal cells after transient focal ischemia.

PubMed

Tan, Chengbo; Zhao, Songji; Higashikawa, Kei; Wang, Zifeng; Kawabori, Masahito; Abumiya, Takeo; Nakayama, Naoki; Kazumata, Ken; Ukon, Naoyuki; Yasui, Hironobu; Tamaki, Nagara; Kuge, Yuji; Shichinohe, Hideo; Houkin, Kiyohiro

2018-05-02

The potential application of bone marrow stromal cell (BMSC) therapy in stroke has been anticipated due to its immunomodulatory effects. Recently, positron emission tomography (PET) with [ 18 F]DPA-714, a translocator protein (TSPO) ligand, has become available for use as a neural inflammatory indicator. We aimed to evaluate the effects of BMSC administration after transient middle cerebral artery occlusion (MCAO) using [ 18 F]DPA-714 PET. The BMSCs or vehicle were administered intravenously to rat MCAO models at 3 h after the insult. Neurological deficits, body weight, infarct volume, and histology were analyzed. [ 18 F]DPA-714 PET was performed 3 and 10 days after MCAO. Rats had severe neurological deficits and body weight loss after MCAO. Cell administration ameliorated these effects as well as the infarct volume. Although weight loss occurred in the spleen and thymus, cell administration suppressed it. In both vehicle and BMSC groups, [ 18 F]DPA-714 PET showed a high standardized uptake value (SUV) around the ischemic area 3 days after MCAO. Although SUV was increased further 10 days after MCAO in both groups, the increase was inhibited in the BMSC group, significantly. Histological analysis showed that an inflammatory reaction occurred in the lymphoid organs and brain after MCAO, which was suppressed in the BMSC group. The present results suggest that BMSC therapy could be effective in ischemic stroke due to modulation of systemic inflammatory responses. The [ 18 F]DPA-714 PET/CT system can accurately demonstrate brain inflammation and evaluate the BMSC therapeutic effect in an imaging context. It has great potential for clinical application.

Ferulic Acid Attenuates the Injury-Induced Decrease of Protein Phosphatase 2A Subunit B in Ischemic Brain Injury

PubMed Central

Koh, Phil-Ok

2013-01-01

Background Ferulic acid provides a neuroprotective effect during cerebral ischemia through its anti-oxidant function. Protein phosphatase 2A (PP2A) is a serine and threonine phosphatase that contributes broadly to normal brain function. This study investigated whether ferulic acid regulates PP2A subunit B in a middle cerebral artery occlusion (MCAO) animal model and glutamate toxicity-induced neuronal cell death. Methodology/Principal Findings MCAO was surgically induced to yield permanent cerebral ischemic injury in rats. The rats were treated with either vehicle or ferulic acid (100 mg/kg, i.v.) immediately after MCAO, and cerebral cortex tissues were collected 24 h after MCAO. A proteomics approach, RT-PCR, and Western blot analyses performed to identification of PP2A subunit B expression levels. Ferulic acid significantly reduced the MCAO-induced infarct volume of the cerebral cortex. A proteomics approach elucidated the reduction of PP2A subunit B in MCAO-induced animals, and ferulic acid treatment prevented the injury-induced reduction in PP2A subunit B levels. RT-PCR and Western blot analyses also showed that ferulic acid treatment attenuates the injury-induced decrease in PP2A subunit B levels. Moreover, the number of PP2A subunit B-positive cells was reduced in MCAO-induced animals, and ferulic acid prevented these decreases. In cultured neuronal cells, ferulic acid treatment protected cells against glutamate toxicity and prevented the glutamate-induced decrease in PP2A subunit B. Conclusions/Significance These results suggest that the maintenance of PP2A subunit B by ferulic acid in ischemic brain injury plays an important role for the neuroprotective function of ferulic acid. PMID:23349830

Neuroprotection of early and short-time applying berberine in the acute phase of cerebral ischemia: up-regulated pAkt, pGSK and pCREB, down-regulated NF-κB expression, ameliorated BBB permeability.

PubMed

Zhang, Xiaolin; Zhang, Xiangjian; Wang, Chaohui; Li, Yanhua; Dong, Lipeng; Cui, Lili; Wang, Lina; Liu, Zongjie; Qiao, Huimin; Zhu, Chunhua; Xing, Yinxue; Cao, Xiaoyun; Ji, Ye; Zhao, Kang

2012-06-12

Berberine (BBR) has gained attention for its vast beneficial biological effects through immunomodulation, anti-inflammatory and anti-apoptosis properties. Inflammatory and apoptosis damage play an important role in cerebral ischemic pathogenesis and may represent a target for treatment. The aim of this study was to explore BBR's effect in ischemic injury and the role of the Akt/GSK (glycogen synthase kinase) signaling cascade in mediating the anti-apoptosis and anti-inflammatory effects in the rat brain of permanent middle cerebral artery occlusion (pMCAO). Male Sprague-Dawley rats were subjected to pMCAO and randomly assigned into four groups: Sham (sham-operated) group, pMCAO (pMCAO+0.9% saline) group, BBR-L (pMCAO+BBR 10 mg/kg) and BBR-H (pMCAO+BBR 40 mg/kg) group. BBR was administered immediately after pMCAO and the neuroprotection was detected. Phospho-Akt (pAkt), phospho-glycogen synthase kinase 3-β (pGSK3β), phospho-cAMP response element binding protein (pCREB), nuclear factor-kappa B (NF-κB) and claudin-5 in ischemic cerebral cortex were detected by immunohistochemistry, reverse transcription-polymerase chain reaction and western blotting. Compared with pMCAO group, BBR dramatically lessened neurological deficits scores, brain water contents and infarct sizes, upregulated the expression of pAkt, pGSK3β, pCREB and claudin-5, and decreased the nuclear accumulation of NF-κB (P<0.05) in ischemic brain. The results showed that BBR reduced ischemic brain injury after pMACO, and this effect may be via the increasing the activation of Akt/GSK signaling and claudin-5, and decreasing NF-κB expression. Copyright © 2012 Elsevier B.V. All rights reserved.

Netrin-1 rescues neuron loss by attenuating secondary apoptosis in ipsilateral thalamic nucleus following focal cerebral infarction in hypertensive rats.

PubMed

Liao, S-J; Gong, Q; Chen, X-R; Ye, L-X; Ding, Q; Zeng, J-S; Yu, J

2013-02-12

Neurological deficit following cerebral infarction correlates with not only primary injury, but also secondary neuronal apoptosis in remote loci connected to the infarction. Netrin-1 is crucial for axonal guidance by interacting with its receptors, deleted in colorectal cancer (DCC) and uncoordinated gene 5H (UNC5H). DCC and UNC5H are also dependence receptors inducing cell apoptosis when unbound by netrin-1. The present study is to investigate the role of netrin-1 and its receptors in ipsilateral ventroposterior thalamic nucleus (VPN) injury secondary to stroke in hypertensive rats. Renovascular hypertensive Sprague-Dawley rats underwent middle cerebral artery occlusion (MCAO). Continuous intracerebroventricular infusion of netrin-1 (600 ng/d for 7 days) or vehicle (IgG/Fc) was given 24h after MCAO. Neurological function was evaluated by postural reflex 8 and 14 days after MCAO. Then, immunoreactivity was determined in the ipsilateral VPN for NeuN, glial fibrillary acidic protein, netrin-1 and its receptors (DCC and UNC5H2), apoptosis was detected with Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling (TUNEL) assay, and the expressions of caspase-3, netrin-1, DCC, and UNC5H2 were quantified by western blot analysis. MCAO resulted in the impaired postural reflex after 8 and 14 days, with decreased NeuN marked neurons and increased TUNEL-positive cells, as well as an up-regulation in the levels of cleaved caspase-3 and UNC5H2 protein in the ipsilateral VPN, without significant change in DCC or netrin-1 expression. By exogenous netrin-1 infusion, the number of neurons was increased in the ipsilateral VPN, and both TUNEL-positive cell number and caspase-3 protein level were reduced, while UNC5H2 expression remained unaffected, simultaneously, the impairment of postural reflex was improved. Taken together, the present study indicates that exogenous netrin-1 could rescue neuron loss by attenuating secondary apoptosis in the

Dragon's blood dropping pills have protective effects on focal cerebral ischemia rats model.

PubMed

Xin, Nian; Yang, Fang-Ju; Li, Yan; Li, Yu-Juan; Dai, Rong-Ji; Meng, Wei-Wei; Chen, Yan; Deng, Yu-Lin

2013-12-15

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis (Lour.) S.C.Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has great traditional medicinal value and is used for wound healing and to stop bleeding. Its main biological activity comes from phenolic compounds. In this study, phenolic compounds were made into dropping pills and their protective effects were examined by establishing focal cerebral ischemia rats model used method of Middle Cerebral Artery Occlusion (MCAO), and by investigating indexes of neurological scores, infarct volume, cerebral index, cerebral water content and oxidation stress. Compared to model group, high, middle and low groups of Dragon's blood dropping pills could improve the neurological function significantly (p<0.01) and reduce cerebral infarct volume of focal cerebral ischemia rats remarkably (p<0.05-0.01). Meanwhile, each group could alleviate cerebral water content and cerebral index (p<0.05-0.01) and regulate oxidative stress of focal cerebral ischemia rats obviously (p<0.05-0.01). Activities of middle group corresponded with that treated with positive control drug. The results obtained here showed that Dragon's blood dropping pills had protective effects on focal cerebral ischemia rats. Copyright © 2013 Elsevier GmbH. All rights reserved.

(-)-Phenserine inhibits neuronal apoptosis following ischemia/reperfusion injury.

PubMed

Chang, Cheng-Fu; Lai, Jing-Huei; Wu, John Chung-Che; Greig, Nigel H; Becker, Robert E; Luo, Yu; Chen, Yen-Hua; Kang, Shuo-Jhen; Chiang, Yung-Hsiao; Chen, Kai-Yun

2017-12-15

Stroke commonly leads to adult disability and death worldwide. Its major symptoms are spastic hemiplegia and discordant motion, consequent to neuronal cell death induced by brain vessel occlusion. Acetylcholinesterase (AChE) is upregulated and allied with inflammation and apoptosis after stroke. Recent studies suggest that AChE inhibition ameliorates ischemia-reperfusion injury and has neuroprotective properties. (-)-Phenserine, a reversible AChE inhibitor, has a broad range of actions independent of its AChE properties, including neuroprotective ones. However, its protective effects and detailed mechanism of action in the rat middle cerebral artery occlusion model (MCAO) remain to be elucidated. This study investigated the therapeutic effects of (-)-phenserine for stroke in the rat focal cerebral ischemia model and oxygen-glucose deprivation/reperfusion (OGD/RP) damage model in SH-SY5Y neuronal cultures. (-)-Phenserine mitigated OGD/PR-induced SH-SY5Y cell death, providing an inverted U-shaped dose-response relationship between concentration and survival. In MCAO challenged rats, (-)-phenserine reduced infarction volume, cell death and improved body asymmetry, a behavioral measure of stoke impact. In both cellular and animal studies, (-)-phenserine elevated brain-derived neurotrophic factor (BDNF) and B-cell lymphoma 2 (Bcl-2) levels, and decreased activated-caspase 3, amyloid precursor protein (APP) and glial fibrillary acidic protein (GFAP) expression, potentially mediated through the ERK-1/2 signaling pathway. These actions mitigated neuronal apoptosis in the stroke penumbra, and decreased matrix metallopeptidase-9 (MMP-9) expression. In synopsis, (-)-phenserine significantly reduced neuronal damage induced by ischemia/reperfusion injury in a rat model of MCAO and cellular model of OGD/RP, demonstrating that its anti-apoptotic/neuroprotective/neurotrophic cholinergic and non-cholinergic properties warrant further evaluation in conditions of brain injury

Long-term behavioral deficits and recovery after transient ischemia in middle-aged rats: Effects of behavioral testing.

PubMed

Yousuf, Seema; Atif, Fahim; Sayeed, Iqbal; Tang, Huiling; Wang, Jun; Stein, Donald G

2015-01-01

Most pre-clinical stroke studies address the acute phase after injury, with less attention to long-term effects of injury, treatment, and experimental testing itself. We addressed these questions: 1) Will functional deficits persist up to 8 weeks following transient stroke in older animals? 2) Will functional deficits resolve spontaneously, with time and/or repeated behavioral testing? Male Sprague-Dawley rats (12 months) were pre-trained on behavioral tasks to provide baseline data and then underwent transient middle artery occlusion (tMCAO) or sham surgery. We measured motor, sensory, cognitive and gait impairments over 8 weeks, and the extent of hemispheric brain infarction. One cohort underwent behavioral testing once at 8 weeks post-stroke (LT); a second cohort (RLT) was tested at 3, 6 and 8 weeks post-stroke. Significant deficits were exhibited in all functional outcomes in both cohorts after 8 weeks. We observed some recovery in some behavioral parameters in both cohorts at 8 weeks. Deficits persist for at least 8 weeks after tMCAO. The greater spontaneous recovery seen in the RLT groups suggest that repeated testing did reduce the severity of these stroke-induced impairments. These findings have implications for designing future studies of agents to induce long-term functional recovery following stroke.

Inhibition of Cathepsin B Alleviates Secondary Degeneration in Ipsilateral Thalamus After Focal Cerebral Infarction in Adult Rats.

PubMed

Zuo, Xialin; Hou, Qinghua; Jin, Jizi; Zhan, Lixuan; Li, Xinyu; Sun, Weiwen; Lin, Kunqin; Xu, En

2016-09-01

Secondary degeneration in areas beyond ischemic foci can inhibit poststroke recovery. The cysteine protease Cathepsin B (CathB) regulates cell death and intracellular protein catabolism. To investigate the roles of CathB in the development of secondary degeneration in the ventroposterior nucleus (VPN) of the ipsilateral thalamus after focal cerebral infarction, infarct volumes, immunohistochemistry and immunofluorescence, and Western blotting analyses were conducted in a distal middle cerebral artery occlusion (dMCAO) stroke model in adult rats. We observed marked neuron loss and gliosis in the ipsilateral thalamus after dMCAO, and the expression of CathB and cleaved caspase-3 in the VPN was significantly upregulated; glial cells were the major source of CathB. Although it had no effect on infarct volume, delayed intracerebroventricular treatment with the membrane-permeable CathB inhibitor CA-074Me suppressed the expression of CathB and cleaved caspase-3 in ipsilateral VPN and accordingly alleviated the secondary degeneration. These data indicate that CathB mediates a novel mechanism of secondary degeneration in the VPN of the ipsilateral thalamus after focal cortical infarction and suggest that CathB might be a therapeutic target for the prevention of secondary degeneration in patients after stroke. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

Neuroprotection by baicalein in ischemic brain injury involves PTEN/AKT pathway.

PubMed

Liu, Chao; Wu, Jiliang; Xu, Kui; Cai, Fei; Gu, Jun; Ma, Liqun; Chen, Jianguo

2010-03-01

Recently more evidences support baicalein (Bai) is neuroprotective in models of ischemic stroke. This study was conducted to determine the molecular mechanisms involved in this effect. Either permanent or transient (2 h) middle cerebral artery occlusion (MCAO) was induced in rats in this study. Permanent MCAO led to larger infarct volumes in contrast to transient MCAO. Only in transient MCAO, Bai administration significantly reduced infarct size. Baicalein also markedly reduced apoptosis in the penumbra of transient MCAO rats. Additionally, oxygen and glucose deprivation (OGD) was used to mimic ischemic insult in primary cultured cortical neurons. A rapid increase in the intracellular reactive oxygen species level and nitrotyrosine formation induced by OGD was counteracted by Bai, which is parallel with attenuated cell injury. The reduction of phosphorylation Akt and glycogen synthase kinase-3beta (GSK3beta) induced by OGD was restored by Bai, which was associated with preserved levels of phosphorylation of PTEN, the phophatase that negatively regulates Akt. As a consequence, Bcl-2/Bcl-xL-associated death protein phosphorylation was increased and the protein level of Bcl-2 in motochondria was maintained, which subsequently antagonize cytochrome c released in cytosol. LY294002 blocked the increase in phospho-AKT evoked by Bai and abolished the associated protective effect. Together, these findings provide evidence that Bai protects neurons against ischemia injury and this neuroprotective effect involves PI3K/Akt and PTEN pathway.

Evaluation of cerebral blood flow changes in focal cerebral ischemia rats by using transcranial Doppler ultrasonography.

PubMed

Li, Le; Ke, Zheng; Tong, Kai Yu; Ying, Michael

2010-04-01

Ischemic stroke is typically characterized by the disruption of cerebral blood flow. This study aimed to consecutively evaluate the cerebral blood flow changes in a focal ischemia rat model during the occlusion-reperfusion procedure and along the recovery stage after stroke. In 12 Sprague Dawley (SD) rats, a middle cerebral artery occlusion/reperfusion (MCAo/r) surgery was conducted, which combines a permanent occlusion of the right common carotid artery (CCA), external carotid artery (ECA) and a transient occlusion of the right internal carotid artery (ICA) and middle cerebral artery (MCA) with a monofilament introduced from the proximal ICA towards the distal right ICA then removed after 90 min. Blood flow velocity (BFV) from the concerned arteries were measured using ultrasonography (13-4 MHz) at the basal stage before the surgery, after the reperfusion stage and during the post-stroke status. At reperfusion stage and after, BFV increased significantly in the left ICA and in the basilar artery (BA) (starting from post-24 h, p < 0.05 vs. basal). Moreover, BFV were reversed in the distal right ICA and reflow was recorded in the right MCA. Time-average maximum BFV in the right MCA at reperfusion and post-stroke 24-96 h was decreased significantly (p < 0.05 vs. basal). The reversed flow in the right ICA was enabled by the settlement of the collateral supply through the circle of Willis which consisted in higher BFV in the opposite ICA and in the BA still 24 h, although the proximal right ICA remain occluded. Ultrasound measurement of BFV helps to provide information on the redistribution of the blood flow supply after the onset of stroke. Copyright 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Ebselen reduces autophagic activation and cell death in the ipsilateral thalamus following focal cerebral infarction.

PubMed

Li, Yiliang; Zhang, Jian; Chen, Li; Xing, Shihui; Li, Jingjing; Zhang, Yusheng; Li, Chuo; Pei, Zhong; Zeng, Jinsheng

2015-07-23

Previous studies have demonstrated that both oxidative stress and autophagy play important roles in secondary neuronal degeneration in the ipsilateral thalamus after distal middle cerebral artery occlusion (MCAO). This study aimed to investigate whether oxidative stress is associated with autophagy activation within the ipsilateral thalamus after distal MCAO. Sixty stroke-prone renovascular hypertensive rats were subjected to distal MCAO or sham operation, and were killed at 14 days after MCAO. Mn-SOD, LC3-II, Beclin-1 and p62 expression were evaluated by immunostaining and immunoblotting. Secondary damage in the thalamus was assessed with Nissl staining and immunostaining. The association of oxidative stress with autophagy activation was investigated by the antioxidant, ebselen. We found that treatment with ebselen at 24h after MCAO significantly reduced the expression of Mn-SOD in the ipsilateral thalamus at 14 days following focal cerebral infarction. In parallel, it prevented the elevation of LC3-II and Beclin-1, and the reduction of p62. Furthermore, ebselen attenuated the neuronal loss and gliosis in the ipsilateral thalamus. These results suggested that ebselen reduced oxidative stress, autophagy activation and secondary damage in the ipsilateral thalamus following MCAO. There are associations between oxidative stress, autophagy activation and secondary damage in the thalamus after MCAO. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Splenectomy Fails to Provide Long-Term Protection Against Ischemic Stroke.

PubMed

Ran, Yuanyuan; Liu, Zongjian; Huang, Shuo; Shen, Jiamei; Li, Fengwu; Zhang, Wenxiu; Chen, Chen; Geng, Xiaokun; Ji, Zhili; Du, Huishan; Hu, Xiaoming

2018-06-01

Splenectomy before or immediately after stroke provides early brain protection. This study aims to explore the effect of splenectomy on long-term neurological recovery after stroke, which is currently lacking in the field. Adult male rats were randomized into splenectomy or sham groups and then subjected to 90 min of middle cerebral artery occlusion (MCAO). Spleen was removed right upon reperfusion or 3d after MCAO. Infarct volume, neurological functions, and peripheral immune cell populations were assessed up to 28d after stroke. The results show that delayed removal of spleen did not reduce brain tissue loss and showed no effect on sensorimotor function (Rotarod, beam balance, forelimb placing, grid walk, and adhesive removal tests) or cognitive function (Morris water maze). Spleen removal immediately upon reperfusion, although significantly reduced the infarct size and immune cell infiltration 3d after MCAO, also failed to promote long-term recovery. Flow cytometry analysis demonstrated that immediate splenectomy after MCAO resulted in a prolonged decrease in the percentage of CD3 + CD4 + and CD3 + CD8 + T cells in total lymphocytes as compared to non-splenectomy MCAO rats. In contrast, the percentage of CD3 - CD45RA + B cells was significantly elevated after splenectomy. As a result, the ratio of T/B cells was significantly reduced in stroke rats with splenectomy. In conclusion, delayed splenectomy failed to provide long-term protection to the ischemic brain or improve functional recovery. The acute neuroprotective effect achieved by early splenectomy after stroke cannot last for long term. This loss of neuroprotection might be related to the prolonged disturbance in the T cell to B cell ratio.

VEGF attenuated increase of outward delayed-rectifier potassium currents in hippocampal neurons induced by focal ischemia via PI3-K pathway.

PubMed

Wu, K W; Yang, P; Li, S S; Liu, C W; Sun, F Y

2015-07-09

We recently indicated that the vascular endothelial growth factor (VEGF) protects neurons against hypoxic death via enhancement of tyrosine phosphorylation of Kv1.2, an isoform of the delayed-rectifier potassium channels through activation of the phosphatidylinositol 3-kinase (PI3-K) signaling pathway. The present study investigated whether VEGF could attenuate ischemia-induced increase of the potassium currents in the hippocampal pyramidal neurons of rats after ischemic injury. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) to induce brain ischemia. The whole-cell patch-clamp technique was used to record the potassium currents of hippocampal neurons in brain slices from the ischemically injured brains of the rats 24h after MCAO. We detected that transient MCAO caused a significant increase of voltage-gated potassium currents (Kv) and outward delayed-rectifier potassium currents (IK), but not outward transient potassium currents (IA), in the ipsilateral hippocampus compared with the sham. Moreover, we found that VEGF could acutely, reversibly and voltage-dependently inhibit the ischemia-induced IK increase. This inhibitory effect of VEGF could be completely abolished by wortmannin, an inhibitor of PI3-K. Our data indicate that VEGF attenuates the ischemia-induced increase of IK via activation of the PI3-K signaling pathway. Published by Elsevier Ltd.

Mapping the dynamics of brain perfusion using functional ultrasound in a rat model of transient middle cerebral artery occlusion

PubMed Central

Brunner, Clément; Isabel, Clothilde; Martin, Abraham; Dussaux, Clara; Savoye, Anne; Emmrich, Julius; Montaldo, Gabriel; Mas, Jean-Louis; Urban, Alan

2015-01-01

Following middle cerebral artery occlusion, tissue outcome ranges from normal to infarcted depending on depth and duration of hypoperfusion as well as occurrence and efficiency of reperfusion. However, the precise time course of these changes in relation to tissue and behavioral outcome remains unsettled. To address these issues, a three-dimensional wide field-of-view and real-time quantitative functional imaging technique able to map perfusion in the rodent brain would be desirable. Here, we applied functional ultrasound imaging, a novel approach to map relative cerebral blood volume without contrast agent, in a rat model of brief proximal transient middle cerebral artery occlusion to assess perfusion in penetrating arterioles and venules acutely and over six days thanks to a thinned-skull preparation. Functional ultrasound imaging efficiently mapped the acute changes in relative cerebral blood volume during occlusion and following reperfusion with high spatial resolution (100 µm), notably documenting marked focal decreases during occlusion, and was able to chart the fine dynamics of tissue reperfusion (rate: one frame/5 s) in the individual rat. No behavioral and only mild post-mortem immunofluorescence changes were observed. Our study suggests functional ultrasound is a particularly well-adapted imaging technique to study cerebral perfusion in acute experimental stroke longitudinally from the hyper-acute up to the chronic stage in the same subject. PMID:26721392

Electroacupuncture ameliorates cognitive impairment and regulates the expression of apoptosis-related genes Bcl-2 and Bax in rats with cerebral ischaemia-reperfusion injury.

PubMed

Liu, Fang; Jiang, Yi-Jing; Zhao, Hong-Jia; Yao, Li-Qun; Chen, Li-Dian

2015-12-01

Post-stroke cognitive impairment seriously affects the quality of life and functional rehabilitation of patients with stroke. To examine the effects of electroacupuncture (EA) at GV20 and GV24 on cognitive impairment and apoptosis including expression of apoptosis-related genes Bcl-2 and Bax in a rat model of cerebral ischaemia-reperfusion (IR) induced by middle cerebral artery occlusion (MCAO). Thirty-five Sprague-Dawley rats were allocated to a sham operation control group (SC group, n=10) or underwent surgery and MCAO (n=25). Postoperatively the latter group was randomly subdivided into EA or untreated (IR) groups. Cognitive impairment was assessed using the Morris water maze (MWM). Apoptosis was examined by detection of Bcl-2 and Bax expression in the cerebral cortex. The EA group had significantly decreased neurological deficit scores compared to the IR group (p<0.05). In the MWM test, significant differences in escape latency and route were observed between the EA and IR groups (p<0.05). Rats in the EA group performed better in the probe trial than those in the IR group (p<0.05). EA treatment markedly reduced the number of TUNEL-positive cells compared to the IR group (20.13±4.30% vs 38.40±3.38%; p<0.001). Reverse transcription-polymerase chain reaction (RT-PCR) results showed the Bcl-2/Bax ratio was significantly increased in the EA group compared to the IR group (1.61±0.19 vs 0.50±0.05, p<0.01). These findings suggest that EA ameliorates cognitive impairment of rats with IR injury by modulating Bcl-2 and Bax expression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Melatonin Ameliorates Injury and Specific Responses of Ischemic Striatal Neurons in Rats

PubMed Central

Ma, Yuxin; Feng, Qiqi; Ma, Jing; Feng, Zhibo; Zhan, Mali; OuYang, Lisi; Mu, Shuhua; Liu, Bingbing; Jiang, Zhuyi; Jia, Yu; Li, Youlan

2013-01-01

Studies have confirmed that middle cerebral artery occlusion (MCAO) causes striatal injury in which oxidative stress is involved in the pathological mechanism. Increasing evidence suggests that melatonin may have a neuroprotective effect on cerebral ischemic damage. This study aimed to examine the morphological changes of different striatal neuron types and the effect of melatonin on striatal injury by MCAO. The results showed that MCAO induced striatum-related dysfunctions of locomotion, coordination, and cognition, which were remarkably relieved with melatonin treatment. MCAO induced severe striatal neuronal apoptosis and loss, which was significantly decreased with melatonin treatment. Within the outer zone of the infarct, the number of Darpp-32+ projection neurons and the densities of dopamine-receptor-1 (D1)+ and dopamine-receptor-2 (D2)+ fibers were reduced; however, both parvalbumin (Parv)+ and choline acetyltransferase (ChAT)+ interneurons were not significantly decreased in number, and neuropeptide Y (NPY)+ and calretinin (Cr)+ interneurons were even increased. With melatonin treatment, the loss of projection neurons and characteristic responses of interneurons were notably attenuated. The present study demonstrates that the projection neurons are rather vulnerable to ischemic damage, whereas the interneurons display resistance and even hyperplasia against injury. In addition, melatonin alleviates striatal dysfunction, neuronal loss, and morphological transformation of interneurons resulting from cerebral ischemia. PMID:23686363

Edaravone, a free radical scavenger, attenuates cerebral infarction and hemorrhagic infarction in rats with hyperglycemia.

PubMed

Okamura, Koichi; Tsubokawa, Tamiji; Johshita, Hiroo; Miyazaki, Hiroshi; Shiokawa, Yoshiaki

2014-01-01

Thrombolysis due to acute ischemic stroke is associated with the risk of hemorrhagic infarction, especially after reperfusion. Recent experimental studies suggest that the main mechanism contributing to hemorrhagic infarction is oxidative stress caused by disruption of the blood-brain barrier. Edaravone, a free radical scavenger, decreases oxidative stress, thereby preventing hemorrhagic infarction during ischemia and reperfusion. In this study, we investigated the effects of edaravone on hemorrhagic infarction in a rat model of hemorrhagic transformation. We used a previously established hemorrhagic transformation model of rats with hyperglycemia. Hyperglycemia was induced by intraperitoneal injection of glucose to all rats (n  =  20). The rats with hyperglycemia showed a high incidence of hemorrhagic infarction. Middle cerebral artery occlusion (MCAO) for 1.5 hours followed by reperfusion for 24 hours was performed in edaravone-treated rats (n  =  10) and control rats (n  =  10). Upon completion of reperfusion, both groups were evaluated for infarct size and hemorrhage volume and the results obtained were compared. Edaravone significantly decreased infarct volume, with the average infarct volume in the edaravone-treated rats (227.6 mm(3)) being significantly lower than that in the control rats (264.0 mm(3)). Edaravone treatment also decreased the postischemic hemorrhage volumes (53.4 mm(3) in edaravone-treated rats vs 176.4 mm(3) in controls). In addition, the ratio of hemorrhage volume to infarct volume was lower in the edaravone-treated rats (23.5%) than in the untreated rats (63.2%). Edaravone attenuates cerebral infarction and hemorrhagic infarction in rats with hyperglycemia.

Administration of sonic hedgehog protein induces angiogenesis and has therapeutic effects after stroke in rats.

PubMed

Chen, Sheng-Cai; Huang, Ming; He, Quan-Wei; Zhang, Yan; Opoku, Elvis Nana; Yang, Hang; Jin, Hui-Juan; Xia, Yuan-Peng; Hu, Bo

2017-06-03

The Sonic hedgehog (Shh) signaling pathway is recapitulated in response to ischemic injury. Here, we investigated the clinical implications of Shh protein in the ischemic stroke and explored the underlying mechanism. Intracerebroventricular injection of Shh, Cyclopamine, or anti-vascular endothelial growth factor (VEGF) was performed immediately after permanent middle cerebral artery occlusion (pMCAO) surgery and lasted for 7days (d). Phosphate-buffered saline (PBS) was used as control. Neurological deficits and infarct volume were examined 7d after pMCAO. Microvascular density with fluorescein-iso-thiocyanate (FITC) assay and double staining with CD31 and Ki-67 was measured at 7d. To observe in vitro angiogenesis, rat brain microvascular endothelial cells (RBMECs) were incubated under oxygen glucose deprivation (OGD) for 6h (h) and treated with Shh/anti-VEGF. We found that (1) Shh improved neurological scores and reduced infarct volume, which was blocked by Cyclopamine, (2) Shh improved the microvascular density and promoted angiogenesis and neuron survival in the ischemic boundary zone, (3) Shh enhanced VEGF expression and VEGF antibody could reverse angiogenic and protective effect of Shh in vivo and in vitro. These data demonstrate that the administration of Shh protein could protect brain from ischemic injury, in part by promoting angiogenic repair. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Comparison of different 3D wavefront sensing and reconstruction techniques for MCAO

NASA Astrophysics Data System (ADS)

Bello, Dolores; Vérinaud, Christophe; Conan, Jean-Marc; Fusco, Thierry; Carbillet, Marcel; Esposito, Simone

2003-02-01

The vertical distribution of the turbulence limits the field of view of classical adaptive optics due to the anisoplanatism. Multiconjugate adaptive optics (MCAO) uses several deformable mirrors conjugated to different layers in the atmosphere to overcome this effect. In the last few years, many studies and developments have been done regarding the analysis of the turbulence volume, and the choice of the wavefront reconstruction techniques.An extensive study of MCAO modelisation and performance estimation has been done at OAA and ONERA. The developed Monte Carlo codes allow to simulate and investigate many aspects: comparison of turbulence analysis strategies (tomography or layer oriented) and comparison of different reconstruction approaches. For instance in the layer oriented approach, the control for a given deformable mirror can be either deduced from the whole set of wavefront sensor measurements or only using the associated wavefront sensor. Numerical simulations are presented showing the advantages and disadvantages of these different options for several cases depending on the number, geometry and magnitude of the guide stars.

Soluble TNF receptor 1-secreting ex vivo-derived dendritic cells reduce injury after stroke.

PubMed

Works, Melissa G; Koenig, Jenny B; Sapolsky, Robert M

2013-09-01

Inflammation is a major factor in the progression of damage after stroke and in the clinic, current therapies treat the clot, not the resulting damage. We have developed a novel method of protein delivery that exploits the migration ability of leukocytes after ischemic stroke (transient middle cerebral artery occlusion; tMCAO). In our studies, ex vivo-derived dendritic cells (exDCs) migrate to the inflamed rat brain soon after tMCAO onset and the number of cells that remain in the brain after injection is significantly correlated with the amount of local inflammation at the injury site. In addition, exDCs transduced to overexpress soluble tumor necrosis factor (TNF) receptor1 (sTNFR1) produce functional cargo that is secreted and that blocks TNF-α bioavailability in vitro. When delivered at 6 hours post-tMCAO reperfusion, sTNFR1-exDC-treated rats show significantly smaller infarct size and decreased inflammation compared with animals treated with exDCs transduced with GFP lentivirus. These studies indicate that cell-mediated delivery of proteins may be a promising new approach to reduce brain damage after acute neurologic insult.

Neuroprotective Efficacy of an Aminopropyl Carbazole Derivative P7C3-A20 in Ischemic Stroke.

PubMed

Wang, Shu-Na; Xu, Tian-Ying; Wang, Xia; Guan, Yun-Feng; Zhang, Sai-Long; Wang, Pei; Miao, Chao-Yu

2016-09-01

NAMPT is a novel therapeutic target of ischemic stroke. The aim of this study was to investigate the effect of a potential NAMPT activator, P7C3-A20, an aminopropyl carbazole derivative, on ischemic stroke. In vitro study, neuron protection effect of P7C3-A20 was investigated by co-incubation with primary neurons subjected to oxygen-glucose deprivation (OGD) or oxygen-glucose deprivation/reperfusion (OGD/R) injury. In vivo experiment, P7C3-A20 was administrated in middle cerebral artery occlusion (MCAO) rats and infarct volume was examined. Lastly, the brain tissue nicotinamide adenine dinucleotide (NAD) levels were detected in P7C3-A20 treated normal or MCAO mice. Cell viability, morphology, and Tuj-1 staining confirmed the neuroprotective effect of P7C3-A20 in OGD or OGD/R model. P7C3-A20 administration significantly reduced cerebral infarction in MCAO rats. Moreover, brain NAD levels were elevated both in normal and MCAO mice after P7C3-A20 treatment. P7C3-A20 has neuroprotective effect in cerebral ischemia. The study contributes to the development of NAMPT activators against ischemic stroke and expands the horizon of the neuroprotective effect of aminopropyl carbazole chemicals. © 2016 John Wiley & Sons Ltd.

Transplantation of cryopreserved human umbilical cord blood mononuclear cells does not induce sustained recovery after experimental stroke in spontaneously hypertensive rats

PubMed Central

Weise, Gesa; Lorenz, Marlene; Pösel, Claudia; Maria Riegelsberger, Ute; Störbeck, Veronika; Kamprad, Manja; Kranz, Alexander; Wagner, Daniel-Christoph; Boltze, Johannes

2014-01-01

Previous studies have highlighted the enormous potential of cell-based therapies for stroke not only to prevent ischemic brain damage, but also to amplify endogenous repair processes. Considering its widespread availability and low immunogenicity human umbilical cord blood (HUCB) is a particularly attractive stem cell source. Our goal was to investigate the neurorestorative potential of cryopreserved HUCB mononuclear cells (MNC) after permanent middle cerebral artery occlusion (MCAO) in spontaneously hypertensive rats (SHR). Human umbilical cord blood MNC or vehicle solution was administered intravenously 24 hours after MCAO. Experimental groups were as follows: (1) quantitative polymerase chain reaction (PCR) of host-derived growth factors up to 48 hours after stroke; (2) immunohistochemical analysis of astroglial scarring; (3) magnetic resonance imaging (MRI) and weekly behavioral tests for 2 months after stroke. Long-term functional outcome and lesion development on MRI were not beneficially influenced by HUCB MNC therapy. Furthermore, HUCB MNC treatment did not change local growth factor levels and glial scarring extent. In summary, we could not demonstrate neurorestorative properties of HUCB MNC after stroke in SHR. Our results advise caution regarding a prompt translation of cord blood therapy into clinical stroke trials as long as deepened knowledge about its precise modes of action is missing. PMID:24169850

17β-Estradiol prevents mesenteric injury induced by occlusion of the proximal descending aorta in male rats.

PubMed

Rocha de Sousa, Paulo Thales; Breithaupt-Faloppa, Ana Cristina; de Jesus Correia, Cristiano; Simão, Raif Restivo; Ferreira, Sueli Gomes; Fiorelli, Alfredo Inácio; Moreira, Luiz Felipe Pinho; Sannomiya, Paulina

2018-02-01

In surgical aortic repair or cardiac surgery with aorta occlusion, the occurrence of mesenteric ischemia and bowel injury has been associated with higher short-term mortality. The vascular protection of estrogens has been investigated and is mainly mediated by increasing the availability of nitric oxide (NO). Therefore, this study investigated the role of 17β-estradiol on visceral ischemia-reperfusion (I/R) injury after descending aorta occlusion in male rats. Mesenteric ischemia was induced in male Wistar rats by placing a 2F Fogarty arterial embolectomy catheter (Edwards Lifesciences, Irvine, Calif) in the descending aorta, which remained occluded for 15 minutes, followed by reperfusion for up to 2 hours. Rats were divided into four groups: (1) rats that underwent surgical manipulation only (sham, n = 22); (2) rats that underwent I/R injury (n = 22); (3) rats treated with intravenous 17β-estradiol (280 μg/kg) 30 minutes before I/R (n = 22); (4) or at the beginning of reperfusion (n = 22). Intestinal histopathologic changes were evaluated by histomorphometry. Mesenteric microcirculatory alterations were assessed by laser Doppler flowmetry and intravital microscopy technique. Protein expression of intercellular adhesion molecule-1, P-selectin, endothelial NO synthase (eNOS), and endothelin-1 was evaluated by immunohistochemistry; in addition, eNOS and endothelin-1 gene expressions were quantified by real-time polymerase chain reaction. Serum cytokines were measured by enzyme-linked immunosorbent assay. Relative to the sham group, the I/R group exhibited a highly pronounced loss of intestine mucosal thickness, a reduction in mesenteric blood flow (P = .0203), increased migrated leukocytes (P < .05), and high mortality rate (35%). Treatment with 17β-estradiol before aorta occlusion preserved intestine mucosal thickness (P = .0437) and mesenteric blood flow (P = .0251), reduced the number of migrated leukocytes (P < .05), and prevented any fatal

EMBOLIC MIDDLE CEREBRAL ARTERY OCCLUSION MODEL USING THROMBIN AND FIBRINOGEN COMPOSED CLOTS IN RAT

PubMed Central

Ren, Ming; Lin, Zi-Jing; Qian, Hai; Gourav, Choudhury Roy; liu, Ran; Liu, Hanli; Yang, Shao-Hua

2012-01-01

Ischemic stroke accounts for over 80% in total human stroke which mostly affect middle cerebral artery (MCA) territory. Embolic stroke models induced by injection of homologous clots into the internal carotid artery and MCA closely mimic human stroke and have been commonly used in stroke research. Studies indicate that the size and composition of clots are critical for the reproducibility of the stroke model. In the present study, we modified the homologous clots formation by addition of thrombin and fibrinogen which produced even distribution of fibrin with tight cross linkage of red blood cells. We optimized the embolic MCA occlusion model in rats using different size of the mixed clots. A precise lodgment of the clots at the MCA bifurcation and highly reproducible ischemic lesion in the MCA territory were demonstrated in the embolic MCA occlusion model induced by injection of 10 pieces of 1-mm long mixed clots made in PE-60 catheter. We further tested the effect of recombinant tissue plasminogen activator (rtPA) in this embolic MCA occlusion model. rtPA induced thrombolysis, improved neurological outcome, and significantly reduced ischemic lesion volume when administered at 1 hour after embolism as compared with control. In summary, we have established a reproducible embolic MCA occlusion model using clots made of homologous blood, thrombin and fibrinogen. The mixed clots enable precise lodgment at the MCA bifurcation which is responsive to thrombolytic therapy of rtPA. PMID:22985597

Embolic middle cerebral artery occlusion model using thrombin and fibrinogen composed clots in rat.

PubMed

Ren, Ming; Lin, Zi-Jing; Qian, Hai; Choudhury, Gourav Roy; Liu, Ran; Liu, Hanli; Yang, Shao-Hua

2012-11-15

Ischemic stroke accounts for over 80% in total human stroke which mostly affect middle cerebral artery (MCA) territory. Embolic stroke models induced by injection of homologous clots into the internal carotid artery and MCA closely mimic human stroke and have been commonly used in stroke research. Studies indicate that the size and composition of clots are critical for the reproducibility of the stroke model. In the present study, we modified the homologous clots formation by addition of thrombin and fibrinogen which produced even distribution of fibrin with tight cross linkage of red blood cells. We optimized the embolic MCA occlusion model in rats using different size of the mixed clots. A precise lodgment of the clots at the MCA bifurcation and highly reproducible ischemic lesion in the MCA territory were demonstrated in the embolic MCA occlusion model induced by injection of 10 pieces of 1-mm long mixed clots made in PE-60 catheter. We further tested the effect of recombinant tissue plasminogen activator (rtPA) in this embolic MCA occlusion model. rtPA induced thrombolysis, improved neurological outcome, and significantly reduced ischemic lesion volume when administered at 1h after embolism as compared with control. In summary, we have established a reproducible embolic MCA occlusion model using clots made of homologous blood, thrombin and fibrinogen. The mixed clots enable precise lodgment at the MCA bifurcation which is responsive to thrombolytic therapy of rtPA. Copyright © 2012 Elsevier B.V. All rights reserved.

Neuroprotective effect of chondroitinase ABC on primary and secondary brain injury after stroke in hypertensive rats.

PubMed

Chen, Xin-ran; Liao, Song-jie; Ye, Lan-xiang; Gong, Qiong; Ding, Qiao; Zeng, Jin-sheng; Yu, Jian

2014-01-16

Focal cerebral infarction causes secondary damage in the ipsilateral ventroposterior thalamic nucleus (VPN). Chondroitin sulfate proteoglycans (CSPGs) are a family of putative inhibitory components, and its degradation by chondroitinase ABC (ChABC) promotes post-injury neurogenesis. This study investigated the role of ChABC in the primary and secondary injury post stroke in hypertension. Renovascular hypertensive Sprague-Dawley rats underwent middle cerebral artery occlusion (MCAO), and were subjected to continuous intra-infarct infusion of ChABC (0.12 U/d for 7 days) 24 h later. Neurological function was evaluated by a modified neurologic severity score. Neurons were counted in the peri-infarct region and the ipsilateral VPN 8 and 14 days after MCAO by Nissl staining and NeuN labeling. The expressions of CSPGs, growth-associated protein-43 (GAP-43) and synaptophysin (SYN) were detected with immunofluorescence or Western blotting. The intra-infarct infusion of ChABC, by degrading accumulated CSPGs, rescued neuronal loss and increased the levels of GAP-43 and SYN in both the ipsilateral cortex and VPN, indicating enhancd neuron survival as well as augmented axonal growth and synaptic plasticity, eventually improving overall neurological function. The study demonstrated that intra-infarct ChABC infusion could salvage the brain from both primary and secondary injury by the intervention on the neuroinhibitory environment post focal cerebral infarction. © 2013 Published by Elsevier B.V.

Andrographolide stimulates p38 mitogen-activated protein kinase-nuclear factor erythroid-2-related factor 2-heme oxygenase 1 signaling in primary cerebral endothelial cells for definite protection against ischemic stroke in rats.

PubMed

Yen, Ting-Lin; Chen, Ray-Jade; Jayakumar, Thanasekaran; Lu, Wan-Jung; Hsieh, Cheng-Ying; Hsu, Ming-Jen; Yang, Chih-Hao; Chang, Chao-Chien; Lin, Yen-Kuang; Lin, Kuan-Hung; Sheu, Joen-Rong

2016-04-01

Stroke pathogenesis involves complex oxidative stress-related pathways. The nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) pathways have been considered molecular targets in pharmacologic intervention for ischemic diseases. Andrographolide, a labdane diterpene, has received increasing attention in recent years because of its various pharmacologic activities. We determined that andrographolide modulates the mitogen-activated protein kinase (MAPK)-Nrf2-HO-1 signaling cascade in primary cerebral endothelial cells (CECs) to provide positive protection against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in rats. In the present study, andrographolide (10 μM) increased HO-1 protein and messenger RNA expressions, Nrf2 phosphorylation, and nuclear translocation in CECs, and these activities were disrupted by a p38 MAPK inhibitor, SB203580, but not by the extracellular signal-regulated kinase inhibitor PD98059 or c-Jun amino-terminal kinase inhibitor SP600125. Similar results were observed in confocal microscopy analysis. Moreover, andrographolide-induced Nrf2 and HO-1 protein expressions were significantly inhibited by Nrf2 small interfering RNA. Moreover, HO-1 knockdown attenuated the protective effect of andrographolide against oxygen-glucose deprivation-induced CEC death. Andrographolide (0.1 mg/kg) significantly suppressed free radical formation, blood-brain barrier disruption, and brain infarction in MCAO-insulted rats, and these effects were reversed by the HO-1 inhibitor zinc protoporphyrin IX. The mechanism is attributable to HO-1 activation, as directly evidenced by andrographolide-induced pronounced HO-1 expression in brain tissues, which was highly localized in the cerebral capillary. In conclusion, andrographolide increased Nrf2-HO-1 expression through p38 MAPK regulation, confirming that it provides protection against MCAO-induced brain injury. These findings provide strong evidence that andrographolide could

Spatiotemporal characterization of brain infarction by sequential multimodal MR imaging following transient focal ischemia in a Rat model of intra-arterial middle cerebral artery occlusion.

PubMed

Gory, Benjamin; Chauveau, Fabien; Bolbos, Radu; Langlois, Jean-Baptiste; Labeyrie, Paul-Emile; Signorelli, Francesco; Turjman, Alexis; Turjman, Francis

2016-12-01

To assess spatiotemporal brain infarction evolution by sequential multimodal magnetic resonance (MR) imaging in an endovascular model of acute stroke in rats. A microwire was selectively placed in the middle cerebral artery (MCA) in 16 consecutives rats during 90 minutes occlusion. Longitudinal 7-T MR imaging, including angiography, diffusion, and perfusion was performed during ischemia, immediately after reperfusion, 3 h and 24 h after subsequent reperfusion. MCA occlusion was complete in 75 % and partial in 18.7 %. Hypoperfusion (mean ± SD) was observed in all animals during ischemia (-59 ± 18 % of contralateral hemisphere, area 31 ± 5 mm 2 ). Infarction volume (mean ± SD) was 90 ± 64 mm 3 during ischemia and 57 ± 67 mm 3 at 24 h. Brain infarction was fronto-parietal cortical in five animals (31 %), striatal in four animals (25 %), and cortico-striatal in seven animals (44 %) at 24 h. All rats survived at 24 h. This model is suitable to neuroprotection studies because of possible acute and close characterization of spatiotemporal evolution of brain infarction by MR imaging techniques, and evidence of ischemic penumbra, the target of neuroprotection agents. However, optimization of the brain infarct reproducibility needs further technical and neurointerventional tools improvements. • Nitinol microwire is MRI compatible allowing spatiotemporal characterization of brain infarction in rats. • Microwire selective placement in middle cerebral artery allows complete artery occlusion in 75 %. • A diffusion/perfusion mismatch during arterial occlusion is observed in 77 % of rats.

Prolonged, 24-h delayed peripheral inflammation increases short- and long-term functional impairment and histopathological damage after focal ischemia in the rat.

PubMed

Langdon, Kristopher D; Maclellan, Crystal L; Corbett, Dale

2010-08-01

The incidence of infection among stroke patients is alarmingly high and both acute and delayed infections increase morbidity and mortality. Experimental studies support the acute clinical data, but little attention has focused on delayed systemic infections. Here, we investigated the effects of prolonged systemic inflammation either before or 24-h after ischemia. Systemic inflammation was induced by injecting rats with three separate doses of lipopolysaccharide (LPS; 50 mug/kg, i.p.) with core temperature monitoring for 48-h after middle cerebral artery occlusion (MCAo). Lipopolysaccharide injected before MCAo increased injury by approximately 30%, whereas delayed injection increased injury by approximately 85% (30-day survival). Proinflammatory cytokines assessed repeatedly for 72 h were significantly and persistently elevated with inflammation. This was accompanied by increases in microglia/macrophage and infiltrating leukocyte numbers in delayed LPS-treated animals. Behavioral assessments at 7 and 30 days revealed approximately 15% deficit in hindlimb function in animals treated with LPS 24-h after ischemia. Clearly, delayed and prolonged postischemic systemic inflammation has devastating effects on stroke outcome, in the absence of a prolonged febrile response. These findings, together with corroborative clinical data, emphasize the importance of early intervention to counteract the deleterious consequences of stroke-associated inflammation and infection.

THR-18, a 18-mer peptide derived from PAI-1, is neuroprotective and improves thrombolysis by tPA in rat stroke models.

PubMed

Krakovsky, M; Polianski, V; Nimrod, A; Higazi, A; Leker, R R; Lamensdorf, I

2011-11-01

The thrombolytic treatment of stroke is limited by a narrow therapeutic time window and is associated with significant adverse side effects. To improve this situation, the modulation of tissue-type plasminogen activator (tPA) activity by a synthetic plasminogen activator inhibitor-1-derived 18-mer peptide (THR-18) was examined in two models of stroke in rats. In the first model (thromboembolic), stroke was induced by intra-carotid injection of micro-clots to rats, and tPA (6 mg/kg) was intravenously infused for 30 minutes with or without THR-18 (1 mg/kg) at 4 hours post-induction. In the second model [transient middle cerebral artery occlusion (tMCAO)], stroke was induced for 2 hours by a transient mechanical occlusion. tPA and/or THR-18 (0.02, 0.1, and 1 mg/kg) were intravenously infused for 60 minutes at the time of reperfusion. In the thromboembolic model, cerebral blood flow, measured before and up to 5.5 hours post-induction, revealed that tPA administration caused reperfusion of flow at 30 minutes post-infusion. Later on, an additional increase in reperfusion was seen in the tPA+THR-18 group, and not with tPA alone. In both models, the frequency of intracranial hemorrhage in the tPA-treated group was found to be significantly higher than the control, and this tPA effect was attenuated by THR-18. In the thromboembolic study, infarct size and brain edema were similar in the control and tPA-treated rats. However, the combination of tPA and THR-18 caused a statistically significant reduction in both parameters (infarct size 17.8 versus 25.0%, brain edema 5 versus 8%, tPA+THR-18 versus control, respectively). In the tMCAO mechanical model, infarct size and brain edema were both increased by tPA treatment as compared to the control group, and this increase was markedly diminished by THR-18 co-administration. Neurobehavioral assessment of the tMCAO animals performed at 72 hours post-stroke induction revealed significant improvements (P<0.05-0.01) in neuroscores in

Ferulic acid attenuates focal cerebral ischemia-induced decreases in p70S6 kinase and S6 phosphorylation.

PubMed

Koh, Phil-Ok

2013-10-25

Ferulic acid exhibits neuroprotective effects against focal cerebral ischemia. PI3/K and Akt signaling pathways play an essential role in protecting against cerebral ischemia. Mammalian target of rapamycin (mTOR), a major downstream target of Akt, regulates p70S6 kinase and S6, both of which are involved in ribosomal biogenesis and protein synthesis. I investigated whether ferulic acid regulates mTOR, p70S6 kinase, and S6 phosphorylation during brain ischemic injury. Rats were treated immediately with vehicle or ferulic acid (100mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brains tissues were removed at 24h after the onset of MCAO and the cerebral cortex regions were collected. Ferulic acid reduced the MCAO-induced infarct volume. I showed previously that ferulic acid prevents the MCAO injury-induced decrease of Akt phosphorylation. In this study, MCAO injury induced decreases in mTOR, p70S6 kinase, and S6 phosphorylation levels, while ferulic acid attenuated the injury-induced decreases. Immunohistochemical staining demonstrated that ferulic acid prevented the MCAO-induced reduction in the number of positive cells for phosphorylated p70S6 kinase and phosphorylated S6. These findings suggest that ferulic acid has a neuroprotective function against focal cerebral ischemia by modulating p70S6 kinase expression and S6 phosphorylation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Ferulic acid attenuates the down-regulation of MEK/ERK/p90RSK signaling pathway in focal cerebral ischemic injury.

PubMed

Koh, Phil-Ok

2015-02-19

Ferulic acid provides neuroprotective effects against a middle cerebral artery occlusion (MCAO)-induced cerebral ischemia. Mitogen-activated protein kinases can regulate extensive intracellular processes including cell differentiation, growth, and death. This study further investigated whether ferulic acid modulates a protective mechanism through the activation of Raf-MEK-ERK and its downstream targets, including 90 ribosomal S6 kinase (p90RSK) and Bad during cerebral ischemic injury. Male Sprague-Dawley rats were treated with ferulic acid (100mg/kg) or vehicle after the onset of MCAO and brain tissues were collected 24h after MCAO. These results indicated that ferulic acid decreases the volume of the infarct area and the number of cells positive in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Although MCAO injury induces a decrease in the phosphorylation of Raf-1, MEK1/2, and ERK1/2, ferulic acid treatment prevents the injury-induced decrease in these phosphorylation levels. Ferulic acid also attenuates the injury-induced decrease in p90RSK and Bad phosphorylation levels. These findings suggest that ferulic acid prevents MCAO-induced neuronal cell death and that the MEK-ERK-p90RSK-Bad signaling pathway is involved in these neuroprotective effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Neuroprotection of Osthole against Cerebral Ischemia/Reperfusion Injury through an Anti-apoptotic Pathway in Rats.

PubMed

Li, Kang; Ding, Dun; Zhang, Ming

2016-01-01

Cerebral ischemia/reperfusion (I/R) injury is a major cause of acute brain injury. The pathogenetic mechanisms underlying I/R injury involve apoptosis, inflammation and oxidative stress. Osthole-a plant coumarin compound-has been reported to protect against focal cerebral I/R-induced injury in rats. However, the mechanism remains unknown. Here we hypothesize that osthole acts through inhibition of apoptosis during focal cerebral I/R injury in rats. We induced cerebral I/R injury by middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion. We randomly assigned 60 rats to three groups (20 rats per group): sham-operated, vehicle-treated I/R, and osthole-treated I/R. We treated rats intraperitoneally with osthole (40 mg/kg) or vehicle 30 min before cerebral ischemia. We harvested the brains for infarct volume, brain water content, histological changes and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining as well as cleaved caspase-3, bax, and bcl-2 levels 24 h after reperfusion. Osthole treatment significantly attenuated cerebral dysfunction and histologic damage induced by I/R injury. Moreover, osthole-treated rats had a dramatic decrease in apoptotic neuronal cells along with a decrease in bax and cleaved caspase-3. The bcl-2 levels increased. Osthole treatment protects the brain from cerebral I/R injury by suppressing cell apoptosis. Thus, osthole may represent a novel practical strategy to prevent cerebral I/R injury.

Secondary Release of Exosomes from Astrocytes Contributes to the Increase in Neural Plasticity and Improvement of Functional Recovery after Stroke in Rats Treated with Exosomes Harvested from MicroRNA 133b-Overexpressing Multipotent Mesenchymal Stromal Cells

PubMed Central

Xin, Hongqi; Wang, Fengjie; Li, Yanfeng; Lu, Qing-E; Cheung, Wing Lee; Zhang, Yi; Zhang, Zheng Gang; Chopp, Michael

2017-01-01

We previously demonstrated that multipotent mesenchymal stromal cells (MSCs) that overexpress microRNA 133b (miR-133b) significantly improve functional recovery in rats subjected to middle cerebral artery occlusion (MCAO) compared with naive MSCs and that exosomes generated from naive MSCs mediate the therapeutic benefits of MSC therapy for stroke. Here we investigated whether exosomes isolated from miR-133b-overexpressing MSCs (Ex-miR-133b+) exert amplified therapeutic effects. Rats subjected to 2 h of MCAO were intra-arterially injected with Ex-miR-133b+, exosomes from MSCs infected by blank vector (Ex-Con), or phosphate-buffered saline (PBS) and were sacrificed 28 days after MCAO. Compared with the PBS treatment, both exosome treatment groups exhibited significant improvement of functional recovery. Ex-miR-133b+ treatment significantly increased functional improvement and neurite remodeling/brain plasticity in the ischemic boundary area compared with the Ex-Con treatment. Treatment with Ex-miR-133b+ also significantly increased brain exosome content compared with Ex-Con treatment. To elucidate mechanisms underlying the enhanced therapeutic effects of Ex-miR-133b+, astrocytes cultured under oxygen- and glucose-deprived (OGD) conditions were incubated with exosomes harvested from naive MSCs (Ex-Naive), miR-133b downregulated MSCs (Ex-miR-133b−), and Ex-miR-133b+. Compared with the Ex-Naive treatment, Ex-miR-133b+ significantly increased exosomes released by OGD astrocytes, whereas Ex-miR-133b− significantly decreased the release. Also, exosomes harvested from OGD astrocytes treated with Ex-miR-133b+ significantly increased neurite branching and elongation of cultured cortical embryonic rat neurons compared with the exosomes from OGD astrocytes subjected to Ex-Con. Our data suggest that exosomes harvested from miR-133b-overexpressing MSCs improve neural plasticity and functional recovery after stroke with a contribution from a stimulated secondary release of

SO2 inhalation contributes to the development and progression of ischemic stroke in the brain.

PubMed

Sang, Nan; Yun, Yang; Li, Hongyan; Hou, Li; Han, Ming; Li, Guangke

2010-04-01

Epidemiological literatures show an association between air pollution and ischemic stroke, and effective pollutants may include SO(2), NO(x), O(3), CO, and particulates. However, existing experimental studies lack evidence as to the presence of effects for SO(2), which has been the focus in developing countries with increasing use of coal as the main resource. In the present study, we treated Wistar rats with SO(2) at various concentrations and determined endothelin-1 (ET-1), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and intercellular adhesion molecule 1 (ICAM-1) messenger RNA (mRNA) and protein expression in the cortex. The results show that SO(2) elevated the levels of ET-1, iNOS, COX-2, and ICAM-1 mRNA and protein in a concentration-dependent manner. Then, we set up rat model of ischemic stroke using middle cerebral artery occlusion (MCAO) and further treated the model rats with filtered air and lower concentration SO(2) for the same period. As expected, elevated expression of ET-1, iNOS, COX-2, and ICAM-1 occurred in the cortex of MCAO model rats exposed to filtered air, followed by increased activation of caspase-3 and cerebral infarct volume. Interestingly, SO(2) inhalation after MCAO significantly amplified above effects. It implies that SO(2) inhalation caused brain injuries similar to that of cerebral ischemia, and its exposure in atmospheric environment contributed to the development and progression of ischemic stroke.

Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis.

PubMed

Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

2016-11-01

Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis.

Transplanted Dental Pulp Stem Cells Migrate to Injured Area and Express Neural Markers in a Rat Model of Cerebral Ischemia.

PubMed

Zhang, Xuemei; Zhou, Yinglian; Li, Hulun; Wang, Rui; Yang, Dan; Li, Bing; Cao, Xiaofang; Fu, Jin

2018-01-01

Ischemic stroke is a major cause of disability and mortality worldwide, while effective restorative treatments are limited at present. Stem cell transplantation holds therapeutic potential for ischemic vascular diseases and may provide an opportunity for neural regeneration. Dental pulp stem cells (DPSCs) origin from neural crest and have neuro-ectodermal features including proliferation and multilineage differentiation potentials. The rat model of middle cerebral artery occlusion (MCAO) was used to evaluate whether intravenous administration of DPSCs can reduce infarct size and to estimate the migration and trans-differentiation into neuron-like cells in focal cerebral ischemia models. Brain tissues were collected at 4 weeks following cell transplantation and analyzed with immunofluorescence, immunohistochemistry and real-time polymerase chain reaction (RT-PCR) methods. Intravenously administration of rat-derived DPSCs were found to migrate into the boundary of ischemic areas and expressed neural specific markers, reducing infarct volume and cerebral edema. These results suggest that DPSCs treatment may serve as a potential therapy for clinical stroke patients in the future. © 2018 The Author(s). Published by S. Karger AG, Basel.

Neuroprotection of dietary virgin olive oil on brain lipidomics during stroke.

PubMed

Rabiei, Zahra; Bigdeli, Mohammad Reza; Rasoulian, Bahram

2013-08-01

Recent studies suggest that dietary virgin olive oil reduces hypoxia-reoxygenation injury in rat brain. This study investigated the effect of pretreatment with different doses of dietary virgin olive oil on brain lipidomics during stroke. In this experimental trial, 60 male Wistar rats were studied in 5 groups of 12 each. The control group received distilled water while three treatment groups received oral virgin olive oil for 30 days (0.25, 0.5 and 0.75 ml/kg/day respectively). Also the sham group received distilled water. Two hours after the last dose, the animals divided two groups. The middle cerebral artery occlusion (MCAO) group subjected to 60 min of middle cerebral artery occlusion (MCAO) and intact groups for brain lipids analysis. The brain phosphatidylcholine, cholesterol ester and cholesterol levels increased significantly in doses of 0.5 and 0.75 ml/kg/day compare with control group. VOO in all three doses increased the brain triglyceride levels. VOO with dose 0.75 ml/kg increased the brain cerebroside levels when compared with control group. VOO pretreatment for 30 days decreased the brain ceramide levels in doses of 0.5 and 0.75 ml/kg/day (p<0.05). Although further studies are needed, the results indicate that the VOO pretreatment improved the injury of ischemia and reperfusion and might be beneficial in patients with these disorders and seems to partly exert their effects via change in brain lipid levels in rat.

Transcriptomic analysis of neuregulin-1 regulated genes following ischemic stroke by computational identification of promoter binding sites: A role for the ETS-1 transcription factor.

PubMed

Surles-Zeigler, Monique C; Li, Yonggang; Distel, Timothy J; Omotayo, Hakeem; Ge, Shaokui; Ford, Byron D

2018-01-01

Ischemic stroke is a major cause of mortality in the United States. We previously showed that neuregulin-1 (NRG1) was neuroprotective in rat models of ischemic stroke. We used gene expression profiling to understand the early cellular and molecular mechanisms of NRG1's effects after the induction of ischemia. Ischemic stroke was induced by middle cerebral artery occlusion (MCAO). Rats were allocated to 3 groups: (1) control, (2) MCAO and (3) MCAO + NRG1. Cortical brain tissues were collected three hours following MCAO and NRG1 treatment and subjected to microarray analysis. Data and statistical analyses were performed using R/Bioconductor platform alongside Genesis, Ingenuity Pathway Analysis and Enrichr software packages. There were 2693 genes differentially regulated following ischemia and NRG1 treatment. These genes were organized by expression patterns into clusters using a K-means clustering algorithm. We further analyzed genes in clusters where ischemia altered gene expression, which was reversed by NRG1 (clusters 4 and 10). NRG1, IRS1, OPA3, and POU6F1 were central linking (node) genes in cluster 4. Conserved Transcription Factor Binding Site Finder (CONFAC) identified ETS-1 as a potential transcriptional regulator of NRG1 suppressed genes following ischemia. A transcription factor activity array showed that ETS-1 activity was increased 2-fold, 3 hours following ischemia and this activity was attenuated by NRG1. These findings reveal key early transcriptional mechanisms associated with neuroprotection by NRG1 in the ischemic penumbra.

The Role of Glutamate Release on Voltage-Dependent Anion Channels (VDAC)-Mediated Apoptosis in an Eleven Vessel Occlusion Model in Rats

PubMed Central

Park, Eunkuk; Lee, Gi-Ja; Choi, Samjin; Choi, Seok-Keun; Chae, Su-Jin; Kang, Sung-Wook; Pak, Youngmi Kim; Park, Hun-Kuk

2010-01-01

Voltage-dependent anion channel (VDAC) is the main protein in mitochondria-mediated apoptosis, and the modulation of VDAC may be induced by the excessive release of extracellular glutamate. This study examined the role of glutamate release on VDAC-mediated apoptosis in an eleven vessel occlusion model in rats. Male Sprague-Dawley rats (250–350 g) were used for the 11 vessel occlusion ischemic model, which were induced for a 10-min transient occlusion. During the ischemic and initial reperfusion episode, the real-time monitoring of the extracellular glutamate concentration was measured using an amperometric microdialysis biosensor and the cerebral blood flow (CBF) was monitored by laser-Doppler flowmetry. To confirm neuronal apoptosis, the brains were removed 72 h after ischemia to detect the neuron-specific nuclear protein and pro-apoptotic proteins (cleaved caspase-3, VDAC, p53 and BAX). The changes in the mitochondrial morphology were measured by atomic force microscopy. A decrease in the % of CBF was observed, and an increase in glutamate release was detected after the onset of ischemia, which continued to increase during the ischemic period. A significantly higher level of glutamate release was observed in the ischemia group. The increased glutamate levels in the ischemia group resulted in the activation of VDAC and pro-apoptotic proteins in the hippocampus with morphological alterations to the mitochondria. This study suggests that an increase in glutamate release promotes VDAC-mediated apoptosis in an 11 vessel occlusion ischemic model. PMID:21203570

Multiple FoV MCAO on its way to the sky

NASA Astrophysics Data System (ADS)

Bergomi, Maria; Viotto, Valentina; Farinato, Jacopo; Marafatto, Luca; Radakrishnan, Kalyan; Ragazzoni, Roberto; Dima, Marco; Magrin, Demetrio; Arcidiacono, Carmelo; Diolaiti, Emiliano; Foppiani, Italo; Lombini, Matteo; Schreiber, Laura; Bertram, Thomas; Bizenberger, Peter; Conrad, Al; Herbst, Tom; Kittmann, Frank; Kopon, Derek; Meschke, Daniel; Zhang, Xianyu

2013-12-01

LINC-NIRVANA, an infrared camera working in a Fizeau interferometric layout, takes advantage of the Layer Oriented MCAO MFoV technique to correct a 2 arcmin FoV using only Natural Guide Stars (NGSs), exploiting the central 10 arcsec with a resolving power of a 23 meter telescope. For each arm of the LBT telescope 2 WaveFront Sensors (WFSs) optically conjugated, respectively at ground and high (7 km) layers, are used to search for NGSs. To avoid unnecessary waste of photons the two sensors look at different FoVs. The ground-layer one, essentially limited by practical conditions, searches for up to 12 NGSs in an annular 2-6 arcmin FoV, while the high-layer one, limited by the pupils superposition, looks for up to 8 NGSs in the central 2 arcmin FoV. The concept has left paper's realm to become glass and metal a few years ago. With the completion of the 2 high-layer WFSs by INAF-Bologna and, recently with the successful tests performed on the first ground-layer WFSs by INAF-Padova, further followed by the GWS Pathfinder experiment to test the ground layer correction at LBT, in collaboration with MPIA-Heidelberg, the concept is finally getting closer to its on-sky commissioning, foreseen in the next very few years. In this paper the basic concepts of MFoV MCAO will be revised, the current status of the system described and the near future toward final completion of the instrument depicted. Moreover a possible path for this concept toward an ELT will be traced.

Osthole prevents cerebral ischemia-reperfusion injury via the Notch signaling pathway.

PubMed

Guan, Junhong; Wei, Xiangtai; Qu, Shengtao; Lv, Tao; Fu, Qiang; Yuan, Ye

2017-08-01

Stroke is a common cerebrovascular disease in aging populations, and constitutes the second highest principle cause of mortality and the principle cause of permanent disability, and ischemic stroke is the primary form. Osthole is a coumarin derivative extracted from the fruits of Cnidium monnieri (L.) Cusson. In this study, we established a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo and found that MCAO/R caused cerebral infarction, hippocampus neuronal injury and apoptosis, and also activated the Notch 1 signaling pathway. However, treatment with osthole further enhanced the activity of Notch 1 signaling and reduced the cerebral infarction as well as the hippocampus neuronal injury and apoptosis induced by MCAO/R in a dose-dependent manner. The same results were observed in a primary neuronal oxygen glucose deficiency/reperfusion (OGD/R) model in vitro, and the effect of osthole could be blocked by an inhibitor of Notch 1 signaling, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine tert-butyl ester (DAPT). Therefore, we demonstrated that osthole injection prevented rat ischemia-reperfusion injury via activating the Notch 1 signaling pathway in vivo and in vitro in a dose-dependent manner, which may be significant for clinical treatment of ischemic stroke.

The cerebral embolism evoked by intra-arterial delivery of allogeneic bone marrow mesenchymal stem cells in rats is related to cell dose and infusion velocity.

PubMed

Cui, Li-li; Kerkelä, Erja; Bakreen, Abdulhameed; Nitzsche, Franziska; Andrzejewska, Anna; Nowakowski, Adam; Janowski, Miroslaw; Walczak, Piotr; Boltze, Johannes; Lukomska, Barbara; Jolkkonen, Jukka

2015-01-27

Intra-arterial cell infusion is an efficient delivery route with which to target organs such as the ischemic brain. However, adverse events including microembolisms and decreased cerebral blood flow were recently reported after intra-arterial cell delivery in rodent models, raising safety concerns. We tested the hypothesis that cell dose, infusion volume, and velocity would be related to the severity of complications after intra-arterial cell delivery. In this study, 38 rats were subjected to a sham middle cerebral artery occlusion (sham-MCAO) procedure before being infused with allogeneic bone-marrow mesenchymal stem cells at different cell doses (0 to 1.0 × 10(6)), infusion volumes (0.5 to 1.0 ml), and infusion times (3 to 6 minutes). An additional group (n = 4) was infused with 1.0 × 10(6) cells labeled with iron oxide for in vivo tracking of cells. Cells were infused through the external carotid artery under laser Doppler flowmetry monitoring 48 hours after sham-MCAO. Magnetic resonance imaging (MRI) was performed 24 hours after cell infusion to reveal cerebral embolisms or hemorrhage. Limb placing, cylinder, and open field tests were conducted to assess sensorimotor functions before the rats were perfused for histology. A cell dose-related reduction in cerebral blood flow was noted, as well as an increase in embolic events and concomitant lesion size, and sensorimotor impairment. In addition, a low infusion velocity (0.5 ml/6 minutes) was associated with high rate of complications. Lesions on MRI were confirmed with histology and corresponded to necrotic cell loss and blood-brain barrier leakage. Particularly cell dose but also infusion velocity contribute to complications encountered after intra-arterial cell transplantation. This should be considered before planning efficacy studies in rats and, potentially, in patients with stroke.

The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS) Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury

PubMed Central

Ljubisavljevic, Milos R.; Javid, Asma; Oommen, Joji; Parekh, Khatija; Nagelkerke, Nico; Shehab, Safa; Adrian, Thomas E.

2015-01-01

Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions. PMID

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

PubMed

Wang, Shanshan; Sun, Hong; Liu, Sainan; Wang, Ting; Guan, Jinqun; Jia, Jianjun

2016-03-01

One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated. Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats. To this end, rats were treated with middle cerebral artery occlusion (MCAO) followed by chronic unpredictable mild stress (CUMS) treatment procedure. We then assessed the expression of CB1 and CB2 receptors in the hypothalamus, and evaluated the effects of pharmacological stimulations of CB1 or CB2 receptors on the expression and development of depression-like behaviors in PSD rats. We found that PSD rats exhibited decreased the expression of CB1 receptor, but not CB2 receptor, in the ventral medial hypothalamus (VMH). Such an effect was not observed in the dorsally adjacent brain regions. Furthermore, intra-VMH injections of CB2 receptor agonist, but not CB1 receptor agonist, attenuated the expression of depression-like behaviors in PSD rats. Finally, repeated intraperitoneal injections of CB1 or CB2 receptor agonists during CUMS treatment inhibited the development of depression-like behaviors in PSD rats. Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

An Innovative Running Wheel-based Mechanism for Improved Rat Training Performance.

PubMed

Chen, Chi-Chun; Yang, Chin-Lung; Chang, Ching-Ping

2016-09-19

This study presents an animal mobility system, equipped with a positioning running wheel (PRW), as a way to quantify the efficacy of an exercise activity for reducing the severity of the effects of the stroke in rats. This system provides more effective animal exercise training than commercially available systems such as treadmills and motorized running wheels (MRWs). In contrast to an MRW that can only achieve speeds below 20 m/min, rats are permitted to run at a stable speed of 30 m/min on a more spacious and high-density rubber running track supported by a 15 cm wide acrylic wheel with a diameter of 55 cm in this work. Using a predefined adaptive acceleration curve, the system not only reduces the operator error but also trains the rats to run persistently until a specified intensity is reached. As a way to evaluate the exercise effectiveness, real-time position of a rat is detected by four pairs of infrared sensors deployed on the running wheel. Once an adaptive acceleration curve is initiated using a microcontroller, the data obtained by the infrared sensors are automatically recorded and analyzed in a computer. For comparison purposes, 3 week training is conducted on rats using a treadmill, an MRW and a PRW. After surgically inducing middle cerebral artery occlusion (MCAo), modified neurological severity scores (mNSS) and an inclined plane test were conducted to assess the neurological damages to the rats. PRW is experimentally validated as the most effective among such animal mobility systems. Furthermore, an exercise effectiveness measure, based on rat position analysis, showed that there is a high negative correlation between the effective exercise and the infarct volume, and can be employed to quantify a rat training in any type of brain damage reduction experiments.

Hyperglycemia decreases expression of 14-3-3 proteins in an animal model of stroke.

PubMed

Jeon, Seong-Jun; Sung, Jin-Hee; Koh, Phil-Ok

2016-07-28

Diabetes is a severe metabolic disorder and a major risk factor for stroke. Stroke severity is worse in patients with diabetes compared to the non-diabetic population. The 14-3-3 proteins are a family of conserved acidic proteins that are ubiquitously expressed in cells and tissues. These proteins are involved in many cellular processes including metabolic pathways, signal transduction, protein trafficking, protein synthesis, and cell cycle control. This study investigated 14-3-3 proteins expression in the cerebral cortex of animals with diabetes, cerebral ischemic injury and a combination of both diabetes and cerebral ischemic injury. Diabetes was induced by intraperitoneal injection of streptozotocin (40mg/kg) in adult male rats. After 4 weeks of treatment, middle cerebral artery occlusion (MCAO) was performed for the induction of focal cerebral ischemia and cerebral cortex tissue was collected 24h after MCAO. We confirmed that diabetes increases infarct volume following MCAO compared to non-diabetic animals. In diabetic animals with MCAO injury, reduction of 14-3-3 β/α, 14-3-3 ζ/δ, 14-3-3 γ, and 14-3-3 ε isoforms was detected. The expression of these proteins was significantly decreased in diabetic animals with MCAO injury compared to diabetic-only and MCAO-only animals. Moreover, Western blot analysis ascertained the decreased expression of 14-3-3 family proteins in diabetic animals with MCAO injury, including β/α, ζ/δ, γ, ε, τ, and η isoforms. These results show the changes of 14-3-3 proteins expression in streptozotocin-induced diabetic animals with MCAO injury. Thus, these findings suggest that decreases in 14-3-3 proteins might be involved in the regulation of 14-3-3 proteins under the presence of diabetes following MCAO. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Salvia miltiorrhiza Bunge (Danshen) extract attenuates permanent cerebral ischemia through inhibiting platelet activation in rats.

PubMed

Fei, Yu-Xiang; Wang, Si-Qi; Yang, Li-Jian; Qiu, Yan-Ying; Li, Yi-Ze; Liu, Wen-Yuan; Xi, Tao; Fang, Wei-Rong; Li, Yun-Man

2017-07-31

Danshen is a crude herbal drug isolated from dried roots of Salvia miltiorrhiza Bunge. This plant is widely used in oriental medicine for the treatment of cardiovascular and cerebrovascular diseases. The supercritical CO 2 extract from Danshen (SCED) (57.85%, 5.67% and 4.55% for tanshinone IIA, tanshinone I and cryptotanshinone respectively) was studied in this article, whose potential molecular mechanism remains unclear, especially in anti-thrombosis. The present study was designed to observe the protective effect of SCED on ischemic stroke in rats and to explore the underlying anti-thrombosis mechanism. Following induction of cerebral ischemia in rats by permanent middle cerebral artery occlusion (pMCAO). Neurological defect score, cerebral blood flow, infarct size, and brain edema were measured to evaluate the injury. Arteriovenous shunt thrombosis model and adenosine 5'-diphosphate (ADP) induced acute pulmonary embolism model were conducted to estimate the antithrombotic effect of SCED. In order to investigate the effects of SCED on platelet aggregation, rat platelet-rich-plasma (PRP) were incubated with SCED prior to the addition of the stimuli (ADP or 9, 11-dideoxy-11α, 9α-epoxymethanoprostaglandin F2α (U46619)). Aggregation was monitored in a light transmission aggregometer. Inhibitory effect of SCED on thromboxane A2 (TXA 2 ) release was detected by ELISA kit. Phospholipase C (PLC)/ Protein kinase C (PKC) signaling pathway was analyzed by a Western blot technique. The effect of the SCED was also studied in vivo on bleeding time in mice. SCED improved the neurological defect score, increased cerebral blood flow, reduced infarct size and alleviated brain edema in rats exposed to pMCAO. After administration of SCED, thrombosis formation in arteriovenous shunt was inhibited and recovery time in pulmonary embolism was shortened. The inhibitory effect of SCED on platelet activation was further confirmed by TXB 2 ELISA kit and Western blot analysis of PLC

Human recombinant glutamate oxaloacetate transaminase 1 (GOT1) supplemented with oxaloacetate induces a protective effect after cerebral ischemia.

PubMed

Pérez-Mato, M; Ramos-Cabrer, P; Sobrino, T; Blanco, M; Ruban, A; Mirelman, D; Menendez, P; Castillo, J; Campos, F

2014-01-09

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment.

Human recombinant glutamate oxaloacetate transaminase 1 (GOT1) supplemented with oxaloacetate induces a protective effect after cerebral ischemia

PubMed Central

Pérez-Mato, M; Ramos-Cabrer, P; Sobrino, T; Blanco, M; Ruban, A; Mirelman, D; Menendez, P; Castillo, J; Campos, F

2014-01-01

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment PMID:24407245

Early VEGF inhibition attenuates blood-brain barrier disruption in ischemic rat brains by regulating the expression of MMPs.

PubMed

Zhang, Hai-Tao; Zhang, Ping; Gao, Yi; Li, Chen-Long; Wang, Hong-Jun; Chen, Ling-Chao; Feng, Yan; Li, Rui-Yan; Li, Yong-Li; Jiang, Chuan-Lu

2017-01-01

Vascular endothelial growth factor (VEGF) inhibition has been demonstrated to be an effective strategy in preserving the integrity of the blood-brain barrier (BBB) in patients with acute ischemic stroke. Loss of the BBB is the key event associated with morbidity and mortality in these patients. However, the underlying mechanisms remain poorly understood. In the present study, the effects of VEGF inhibition and the possible mechanism that underlies acute cerebral ischemia in rats was investigated. Following the induction of transient middle cerebral artery occlusion for a 90‑min period, either an anti‑VEGF neutralizing antibody (RB‑222; 5 or 10 µg), or IgG (control), was administered by intracerebroventricular injection at 1 h following reperfusion. Functional outcomes, BBB leakage, brain edema, microvessel numbers and the relative protein levels of VEGF, matrix metalloproteinase (MMP)-2, MMP-9, occludin and collagen-IV were then determined using neurological assessments, Evans Blue staining, brain water content, CD31 staining and western blotting. Treatment with RB‑222 at a dose of 5 and 10 µg significantly improved neurological functional outcomes and diminished infarct size, BBB leakage and brain edema compared with the MCAO and IgG groups at 24 h following reperfusion; 10 µg RB‑222 was more effective than a 5 µg dose of the antibody. In addition, RB‑222 reduced the number of immature microvessels, which subsequently attenuated BBB permeability. RB‑222 significantly repressed VEGF expression as well as decreased MMP‑2 and MMP‑9 expression. However, it enhanced occludin and collagen‑IV levels in the ischemic rat brain compared with the MCAO and IgG groups. Taken together, the results indicate that early inhibition of VEGF may have significant potential against cerebral ischemia, partly by regulating the expression of MMPs.

Hyperphosphorylation of tau protein in the ipsilateral thalamus after focal cortical infarction in rats.

PubMed

Dong, Da-Wei; Zhang, Yu-Sheng; Yang, Wan-Yong; Wang-Qin, Run-Qi; Xu, An-Ding; Ruan, Yi-Wen

2014-01-16

Hyperphosphorylation of tau has been considered as an important risk factor for neurodegenerative diseases. It has been found also in the cortex after focal cerebral ischemia. The present study is aimed at investigating changes of tau protein expression in the ipsilateral thalamus remote from the primary ischemic lesion site after distal middle cerebral artery occlusion (MCAO). The number of neurons in the ventroposterior thalamic nucleus (VPN) was evaluated using Nissl staining and neuronal nuclei (NeuN) immunostaining. Total tau and phosphorylated tau at threonine 231 (p-T231-tau) and serine 199 (p-S199-tau) levels, respectively, in the thalamus were measured using immunostaining and immunoblotting. Moreover, apoptosis was detected with terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling (TUNEL) assay. It was found that the numbers of intact neurons and NeuN(+) cells within the ipsilateral VPN were reduced significantly compared with the sham-operated group, but the levels of p-T231-tau and p-S199-tau in the ipsilateral thalamus were increased significantly in rats subjected to ischemia for 3 days, 7 days and 28 days. Furthermore, the number of TUNEL-positive cells was increased in the ipsilateral VPN at 7 days and 28 days after MCAO. Thus, hyperphosphorylated tau protein is observed in ipsilateral thalamus after focal cerebral infarction in this study. Our findings suggest that the expression of hyperphosphorylated tau protein induced by ischemia may be associated with the secondary thalamic damage after focal cortical infarction via an apoptotic pathway. © 2013 Published by Elsevier B.V.

Rivaroxaban does not influence hemorrhagic transformation in a diabetes ischemic stroke and endovascular thrombectomy model.

PubMed

Liu, Feng-Di; Zhao, Rong; Feng, Xiao-Yan; Shi, Yan-Hui; Wu, Yi-Lan; Shen, Xiao-Lei; Li, Ge-Fei; Liu, Yi-Sheng; Zhao, Ying; He, Xin-Wei; Yin, Jia-Wen; Zhuang, Mei-Ting; Zhao, Bing-Qiao; Liu, Jian-Ren

2018-05-09

Managing endovascular thrombectomy (ET) in diabetic ischemic stroke (IS) with novel anticoagulants is challenging due to putative risk of intracerebral hemorrhage. The study evaluates increased hemorrhagic transformation (HT) risk in Rivaroxaban-treated diabetic rats post ET. Diabetes was induced in male Sprague-Dawley rats by intraperitoneal injection of 60 mg/kg streptozotocin. After 4-weeks, rats were pretreated orally with 30 mg/kg Rivaroxaban/saline; prothrombin time was monitored. IS and ET was induced after 1 h, by thread-induced transient middle cerebral artery occlusion (tMCAO) that mimicked mechanical ET for proximal MCA occlusion at 60 min. After 24 h reperfusion, infarct volumes, HT, blood-brain barrier (BBB) permeability, tight junction at peri-ischemic lesion and matrix metalloproteinase-9 (MMP-9) activity was measured. Diabetic rats seemed to exhibit increased infarct volume and HT at 24 h after ET than normal rats. Infarct volumes and functional outcomes did not differ between Rivaroxaban and diabetic control groups. A significant increase in HT volumes and BBB permeability under Rivaroxaban treatment was not detected. Compared to diabetic control group, neither the occludin expression was remarkably lower in the Rivaroxaban group nor the MMP-9 activity was higher. Together, Rivaroxaban does not increase HT after ET in diabetic rats with proximal MCA occlusion, since Rivaroxaban has fewer effects on post-ischemic BBB permeability.

Occlusion of carotid artery and hypergravity loading of animals caused similar effects on L-[14C]glutamate uptake in rat brain nerve terminals

NASA Astrophysics Data System (ADS)

Borisova, Tatiana; Sivko, Roman; Krisanova, Natalia

Changes in sodium-dependent L-[14C]glutamate uptake in rat brain nerve terminals was com-paratively analysed after hypergravity loading of animals (centrifugation of rats in special con-tainers at 10 G for 1 hour) and unilateral occlusion of carotid artery (20 min). The initial velocity of L-[14C]glutamate uptake was decreased from 2.5 ± 0.2 nmol x min-1 x mg-1 of proteins to 2.05 ± 0.1 nmol x min-1 x mg-1 of proteins after hypergravity and after occlusion -up to 2.25 ± 0.1 nmol x min-1 x mg-1 of proteins. Recently, we have shown that a decrease in L-[14C]glutamate uptake was at least partially caused by the redaction in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. These parameters were analysed after unilateral occlusion of carotid artery, where one brain hemisphere was used as a control, whereas the second one as subjected to ischemic/hypoxic conditions. Similarly with hypergravity, we revealed a decrease in the membrane potential of nerve terminals by ˜ 10 % and a reduction of the proton gradient of synaptic vesicles by ˜ 5 % after occlusion of carotid artery. Thus, a decrease in the activity of glutamate transporters after hypergrav-ity and unilateral occlusion of carotid artery was at least partially caused by changes in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. This fact may be considered in support of the suggestion that ischemia/hypoxia was a main unspecific stressor, which caused the alterations in glutamatergic neurotransmission under conditions of hypergravity.

Ferulic acid prevents cerebral ischemic injury-induced reduction of hippocalcin expression.

PubMed

Koh, Phil-Ok

2013-07-01

Intracellular calcium overload is a critical pathophysiological factor in ischemic injury. Hippocalcin is a neuronal calcium sensor protein that buffers intracellular calcium levels and protects cells from apoptotic stimuli. Ferulic acid exerts a neuroprotective effect in cerebral ischemia through its anti-oxidant and anti-inflammation activity. This study investigated whether ferulic acid contributes to hippocalcin expression during cerebral ischemia and glutamate exposure-induced neuronal cell death. Rats were immediately treated with vehicle or ferulic acid (100 mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO and followed by assessment of cerebral infarct. Ferulic acid reduced MCAO-induced infarct regions. A proteomics approach elucidated a decrease in hippocalcin in MCAO-operated animals, ferulic acid attenuates the injury-induced decrease in hippocalcin expression. Reverse transcription-polymerase chain reaction and Western blot analyses confirmed that ferulic acid prevents the injury-induced decrease in hippocalcin. In cultured HT22 hippocampal cells, glutamate exposure increased the intracellular Ca(2+) levels, whereas ferulic acid attenuated this increase. Moreover, ferulic acid attenuated the glutamate toxicity-induced decrease in hippocalcin expression. These findings can suggest the possibility that ferulic acid exerts a neuroprotective effect through modulating hippocalcine expression and regulating intracellular calcium levels. Copyright © 2013 Wiley Periodicals, Inc.

Neuroprotective Effect of Curcumin Against Cerebral Ischemia-Reperfusion Via Mediating Autophagy and Inflammation.

PubMed

Huang, Lifa; Chen, Chengwei; Zhang, Xin; Li, Xu; Chen, Zupeng; Yang, Chao; Liang, Xiaolong; Zhu, Guochong; Xu, Zhen

2018-01-01

Curcumin, a polyphenolic compound extracted from Curcuma longa, has drawn attention for its effective bioactivities against ischemia-induced injury. This study aimed to evaluate the neuroprotective effect of curcumin and investigate the underlying mechanism that mediates autophagy and inflammation in an animal model of middle cerebral artery occlusion (MCAO) in rats. Curcumin was delivered to Sprague Dawley male rats at a dose of 200 mg/kg curcumin by intraperitoneal injection 30 min after ischemia-reperfusion (I/R). LY294002, a specific inhibitor of the PI3K/Akt/mTOR pathway, as well as anisomycin, an activator of TLR4/p38/MAPK, was administered by ventricle injection 30 min before MCAO. The same volume of saline was given as a control. Brain infarction and neurological function were determined 24 h post-MCAO. Immunoblotting and immunofluorescence were used to detect alterations in autophagy-relevant proteins Akt, p-Akt, mTOR, p-mTOR, LC3-II, and LC3-I, and inflammation-related proteins TLR4, p-38, p-p38, and IL-1 in the ipsilateral hemisphere. Cerebral I/R injury resulted in significant alterations of LC3-II/LC3-I, IL-1, TLR4, and p-p38. Curcumin in MCAO rats significantly improved brain damage and neurological function by upregulating p-Akt and p-mTOR and downregulating LC3-II/LC3-I, IL-1, TLR4, p-38, and p-p38. However, these protective effects against ischemia could be suppressed when LY294002 or anisomycin was included. Curcumin exerts neuroprotective effects by attenuating autophagic activities through mediating the PI3K/Akt/mTOR pathway, while also suppressing an inflammatory reaction by regulating the TLR4/p38/MAPK pathway. Furthermore, this study indicates that curcumin could be an effective therapy for patients afflicted with ischemia.

Depletion of CD11c+ Cells Does Not Influence Outcomes in Mice Subjected to Transient Middle Cerebral Artery Occlusion.

PubMed

Kraft, Peter; Scholtyschik, Karolina; Schuhmann, Michael K; Kleinschnitz, Christoph

2017-01-01

While it has been shown that different T-cell subsets have a detrimental role in the acute phase of ischemic stroke, data on the impact of dendritic cells (DC) are missing. Classic DC can be characterized by the cluster of differentiation (CD)11c surface antigen. In this study, we depleted CD11c+ cells by using a CD11c-diphtheria toxin (DTX) receptor mouse strain that allows selective depletion of CD11c+ cells by DTX injection. For stroke induction, we used the model of transient middle cerebral artery occlusion (tMCAO) and analyzed stroke volume and functional outcome on days 1 and 3 as well as expression of prototypical pro- and anti-inflammatory cytokines on day 1 after tMCAO. Three different protocols for CD11c+ cell depletion, tMCAO duration, and readout time point were applied. Injection of DTX (5 or 100 ng/g) reliably depleted CD11c+ cells without influencing the fractions of other immune cell subsets. CD11c+ cell depletion had no impact on stroke volume, but mice with a longer DTX pretreatment performed worse than those with vehicle treatment. CD11c+ cell depletion led to a decrease in cortical interleukin (IL)-1β and IL-6 messenger ribonucleic acid levels. We show, for the first time, that CD11c+ cell depletion does not influence stroke volume in a mouse model of focal cerebral ischemia. Nevertheless, given the unspecificity of the CD11c surface antigen for DC, mouse models that allow a more selective depletion of DC are needed to investigate the role of DC in stroke pathophysiology. © 2017 S. Karger AG, Basel.

Morphologic study of tissue changes occurring in the apical third and periapex of rat molars after endodontic treatment performed under different occlusal conditions.

PubMed

Sato, E F; Antoniazzi, J H; Bauer, J A

1994-01-01

The purpose of the present study was to carry out a histologic study of the periapical changes of the maxillary first molar of rats submitted to endodontic treatment under different occlusal conditions. The experiment was carried out under conditions analogous to those used in clinical practice. Pulpotomy, pulpectomy and chemomechanical preparation of the mesial root canal were carried out according to previously established techniques and the mesial root canal was filled with cement and gutta-percha. A glass ionomer cement was used as restorative material under conditions of subocclusion, normal occlusion and excessive occlusal forces. No inflammatory reaction of periapical tissue was observed under the three conditions used, and active closing of the root canal was observed 15 days after the procedure, with the formation of cementum replacing the pulpar remnant.

Effects of total saponins from Trillium tschonoskii rhizome on grey and white matter injury evaluated by quantitative multiparametric MRI in a rat model of ischemic stroke.

PubMed

Li, Manzhong; Ouyang, Junyao; Zhang, Yi; Cheng, Brian Chi Yan; Zhan, Yu; Yang, Le; Zou, Haiyan; Zhao, Hui

2018-04-06

Trillium tschonoskii rhizome (TTR), a medicinal herb, has been traditionally used to treat traumatic brain injury and headache in China. Although the potential neuroprotective efficacy of TTR has gained increasing interest, the pharmacological mechanism remains unclear. Steroid saponins are the main bioactive components of the herb. To investigate the protective and repair-promoting effects of the total saponins from TTR (TSTT) on grey and white matter damages in a rat model of middle cerebral artery occlusion (MCAO) using magnetic resonance imaging (MRI) assay. Ischemic stroke was induced by MCAO. TSTT and Ginaton (positive control) were administered orally to rats 6h after stroke and daily thereafter. After 15 days of treatment, the survival rate of each group was calculated. We then conducted neurological deficit scores and beam walking test to access the neurological function after ischemic stroke. Subsequently, T2-weighted imaging (T2WI) and T2 relaxometry mapping were performed to measure infarct volume and grey and white matter integrity, respectively. Moreover, diffusion tensor imaging (DTI) was carried out to evaluate the grey and white matter microstructural damage. Additionally, arterial spin labelling (ASL) - cerebral blood flow (CBF) and magnetic resonance angiography (MRA) images provided dynamic information about vascular hemodynamic dysfunction after ischemic stroke. Finally, haematoxylin and eosin (HE) staining was carried out to evaluate the stroke-induced pathological changes in the brain. The survival rate and neurological behavioural outcomes (Bederson scores and beam walking tests) were markedly ameliorated by TSTT (65mg/kg) treatment within 15 days after ischemic stroke. Moreover, T2WI and T2 relaxometry mapping showed that TSTT (65mg/kg) significantly reduced infarct volume and attenuated grey and white matter injury, respectively, which was confirmed by histopathological evaluation of brain tissue. The results obtained from DTI showed that

Alcohol-induced chronic pancreatitis in rats after temporary occlusion of biliopancreatic ducts with Ethibloc.

PubMed

Pap, A; Boros, L

1989-01-01

Chronic obstructive pancreatitis-like histological and biochemical alterations were provoked in male Wistar rats with Ethibloc occlusion of the common bile duct and the main pancreatic ducts. After the disappearance of the glue from the ducts, a gradual and almost total recovery was demonstrated during a 2-month observation period. About 12 g/kg of alcohol (20% vol/vol) given daily by gastric intubation and ad libitum intake inhibited the recovery of pancreatic weight and enzyme contents in the occluded rats, and within a 2-month period chronic calcifying-type pancreatitis became evident with some signs of remaining obstructive pancreatitis-like lesions. Cessation of alcohol administration after 2 months resulted in a recovery of pancreatic weight and enzyme contents, although morphological regeneration was less pronounced and calcification remained visible in some rats. A 50% raw soy flour diet provoked some further changes in the proportion of enzymes without any supplementary increases of pancreatic weight and protein content. This animal model of chronic pancreatitis demonstrates that chronic obstructive and calcifying pancreatitis can appear together and earlier if the etiological factors act in combination. Suppression of pancreatic regeneration by alcohol seems to be necessary to maintain chronic pancreatitis-like lesions and to develop calcification.

Tanshinone inhibits neuronal cell apoptosis and inflammatory response in cerebral infarction rat model

PubMed Central

Zhou, Liang; Zhang, Jie; Wang, Chao; Sun, Qiangsan

2017-01-01

We aimed to investigate the effect and mechanisms of tanshinone (TSN) IIA in cerebral infarction. The cerebral infarction rat model was established by middle cerebral artery occlusion (MCAO). After pretreatment with TSN, cerebral infarct volume, cerebral edema, and neurological deficits score were evaluated, as well as cell apoptosis in hippocampus and cortex of the brain was examined with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). In addition, rat primary neuronal cells were isolated and cultured in oxygen-glucose deprivation (OGD) conditions. After pretreatment with TSN, cell viability and apoptosis were observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. The expressions of Bax and B-cell lymphoma 2 (Bcl-2) were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. Compared with untreated cerebral infarction rat, TSN treatment significantly reduced cerebral infarct volume, cerebral edema, and neurological deficits score (P < 0.05). Cell apoptosis as well as the levels of IL-6, TNF-α, and CRP in hippocampus and cortex of cerebral infarction rat were inhibited after pretreatment with TSN (P < 0.05). Furthermore, TSN remarkably increased cell viability and inhibited cell apoptosis ratio (P < 0.05) in OGD-induced rat neuronal cells. Besides, TSN significantly downregulated the expression of Bax and upregulated Bcl-2 (P < 0.05). TSN IIA has a preventive effect on cerebral infarction by inhibiting neuronal cell apoptosis and inflammatory response in vitro and in vivo. PMID:28402151

Tanshinone inhibits neuronal cell apoptosis and inflammatory response in cerebral infarction rat model.

PubMed

Zhou, Liang; Zhang, Jie; Wang, Chao; Sun, Qiangsan

2017-06-01

We aimed to investigate the effect and mechanisms of tanshinone (TSN) IIA in cerebral infarction. The cerebral infarction rat model was established by middle cerebral artery occlusion (MCAO). After pretreatment with TSN, cerebral infarct volume, cerebral edema, and neurological deficits score were evaluated, as well as cell apoptosis in hippocampus and cortex of the brain was examined with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). In addition, rat primary neuronal cells were isolated and cultured in oxygen-glucose deprivation (OGD) conditions. After pretreatment with TSN, cell viability and apoptosis were observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. The expressions of Bax and B-cell lymphoma 2 (Bcl-2) were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. Compared with untreated cerebral infarction rat, TSN treatment significantly reduced cerebral infarct volume, cerebral edema, and neurological deficits score ( P < 0.05). Cell apoptosis as well as the levels of IL-6, TNF-α, and CRP in hippocampus and cortex of cerebral infarction rat were inhibited after pretreatment with TSN ( P < 0.05). Furthermore, TSN remarkably increased cell viability and inhibited cell apoptosis ratio ( P < 0.05) in OGD-induced rat neuronal cells. Besides, TSN significantly downregulated the expression of Bax and upregulated Bcl-2 ( P < 0.05). TSN IIA has a preventive effect on cerebral infarction by inhibiting neuronal cell apoptosis and inflammatory response in vitro and in vivo.

A simple and efficient method for generating Nurr1-positive neuronal stem cells from human wisdom teeth (tNSC) and the potential of tNSC for stroke therapy.

PubMed

Yang, Kuo-Liang; Chen, Mei-Fang; Liao, Chia-Hsin; Pang, Cheng-Yoong; Lin, Py-Yu

2009-01-01

We have isolated human neuronal stem cells from exfoliated third molars (wisdom teeth) using a simple and efficient method. The cultured neuronal stem cells (designated tNSC) expressed embryonic and adult stem cell markers, markers for chemotatic factor and its corresponding ligand, as well as neuron proteins. The tNSC expressed genes of Nurr1, NF-M and nestin. They were used to treat middle cerebral artery occlusion (MCAO) surgery-inflicted Sprague-Dawley (SD) rats to assess their therapeutic potential for stroke therapy. For each tNSC cell line, a normal human impacted wisdom tooth was collected from a donor with consent. The tooth was cleaned thoroughly with normal saline. The molar was vigorously shaken or vortexed for 30 min in a 50-mL conical tube with 15-20mL normal saline. The mixture of dental pulp was collected by centrifugation and cultured in a 25-cm(2) tissue culture flask with 4-5mL Medium 199 supplemented with 5-10% fetal calf serum. The tNSC harvested from tissue culture, at a concentration of 1-2x10(5), were suspended in 3 microL saline solution and injected into the right dorsolateral striatum of experimental animals inflicted with MCAO. Behavioral measurements of the tNSC-treated SD rats showed a significant recovery from neurologic dysfunction after MCAO treatment. In contrast, a sham group of SD rats failed to recover from the surgery. Immunohistochemistry analysis of brain sections of the tNSC-treated SD rats showed survival of the transplanted cells. These results suggest that adult neuronal stem cells may be procured from third molars, and tNSC thus cultivated have potential for treatment of stroke-inflicted rats.

Hemopexin induces neuroprotection in the rat subjected to focal cerebral ischemia.

PubMed

Dong, Beibei; Cai, Min; Fang, Zongping; Wei, Haidong; Zhu, Fangyun; Li, Guochao; Dong, Hailong; Xiong, Lize

2013-06-10

The plasma protein hemopexin (HPX) exhibits the highest binding affinity to free heme. In vitro experiments and gene-knock out technique have suggested that HPX may have a neuroprotective effect. However, the expression of HPX in the brain was not well elucidated and its expression after cerebral ischemia-reperfusion injury was also poorly studied. Furthermore, no in vivo data were available on the effect of HPX given centrally on the prognosis of focal cerebral ischemia. In the present study, we systematically investigated expression of HPX in normal rat brain by immunofluorescent staining. The results showed that HPX was mainly expressed in vascular system and neurons, as well as in a small portion of astrocytes adjacent to the vessels in normal rat brain. Further, we determined the role of HPX in the process of focal cerebral ischemic injury and explored the effects of HPX treatment in a rat model of transient focal cerebral ischemia. After 2 h' middle cerebral artery occlusion (MCAO) followed by 24 h' reperfusion, the expression of HPX was increased in the neurons and astrocytes in the penumbra area, as demonstrated by immunohistochemistry and Western blot techniques. Intracerebroventricular injection of HPX at the onset of reperfusion dose-dependently reduced the infarct volumes and improved measurements of neurological function of the rat subjected to transient focal cerebral ischemia. The neuroprotective effects of HPX sustained for up to 7 days after experiments. Our study provides a new insight into the potential neuroprotective role of HPX as a contributing factor of endogenous protective mechanisms against focal cerebral ischemia injury, and HPX might be developed as a potential agent for treatment of ischemic stroke.

High-dose estrogen treatment at reperfusion reduces lesion volume and accelerates recovery of sensorimotor function after experimental ischemic stroke.

PubMed

Carpenter, Randall S; Iwuchukwu, Ifeanyi; Hinkson, Cyrus L; Reitz, Sydney; Lee, Wonhee; Kukino, Ayaka; Zhang, An; Pike, Martin M; Ardelt, Agnieszka A

2016-05-15

Estrogens have previously been shown to protect the brain against acute ischemic insults, by potentially augmenting cerebrovascular function after ischemic stroke. The current study hypothesized that treatment with sustained release of high-dose 17β-estradiol (E2) at the time of reperfusion from middle cerebral artery occlusion (MCAO) in rats would attenuate reperfusion injury, augment post-stroke angiogenesis and cerebral blood flow, and attenuate lesion volume. Female Wistar rats underwent ovariectomy, followed two weeks later by transient, two-hour right MCAO (tMCAO) and treatment with E2 (n=13) or placebo (P; n=12) pellets starting at reperfusion. E2 treatment resulted in significantly smaller total lesion volume, smaller lesions within striatal and cortical brain regions, and less atrophy of the ipsilateral hemisphere after six weeks of recovery. E2-treated animals exhibited accelerated recovery of contralateral forelimb sensorimotor function in the cylinder test. Magnetic resonance imaging (MRI) showed that E2 treatment reduced the formation of lesion cysts, decreased lesion volume, and increased lesional cerebral blood flow (CBF). K(trans), a measure of vascular permeability, was increased in the lesions. This finding, which represents lesion neovascularization, was not altered by E2 treatment. Ischemic stroke-related angiogenesis and vessel formation was confirmed with immunolabeling of brain tissue and was not altered with E2 treatment. In summary, E2 treatment administered immediately following reperfusion significantly reduced lesion size, cyst formation, and brain atrophy while improving lesional CBF and accelerating recovery of functional deficits in a rat model of ischemic stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

Suppressing Receptor-Interacting Protein 140: a New Sight for Salidroside to Treat Cerebral Ischemia.

PubMed

Chen, Tong; Ma, Zhanqiang; Zhu, Lingpeng; Jiang, Wenjiao; Wei, Tingting; Zhou, Rui; Luo, Fen; Zhang, Kai; Fu, Qiang; Ma, Chunhua; Yan, Tianhua

2016-11-01

The purpose of the current study was to detect the effect of salidroside (Sal) on cerebral ischemia and explore its potential mechanism. Middle cerebral artery occlusion (MCAO) was performed to investigate the effects of Sal on cerebral ischemia. The rats were randomly divided into five groups: sham group, vehicle group, clopidogrel (7.5 mg/kg) group, Sal (20 mg/kg) group, and Sal (40 mg/kg) group. SH-SY5Y cells were exposed to ischemia-reperfusion (I/R) injury to verify the protective effect of Sal in vitro. We also built the stable receptor-interacting protein 140 (RIP140)-overexpressing SH-SY5Y cells. The results showed that Sal significantly reduces brain infarct size and cerebral edema. Sal could effectively decrease the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in serum of the MCAO rats and supernatant of I/R-induced SH-SY5Y cells. Immunohistochemical and Western blot results demonstrated that Sal inhibited RIP140-mediated inflammation and apoptosis in the MCAO rats and SH-SY5Y cells. In addition, we further confirmed that RIP140/NF-κB signaling plays a crucial role by evaluating the protein expression in RIP140-overexpressing SH-SY5Y cells. Our findings suggested that Sal could be used as an effective neuroprotective agent for cerebral ischemia due to its significant effect on preventing neuronal cell injury after cerebral ischemia both in vivo and in vitro by the inhibitions of RIP140-mediated inflammation and apoptosis.

Protective effect of estrogen in endothelin-induced middle cerebral artery occlusion in female rats.

PubMed

Glendenning, Michele L; Lovekamp-Swan, Tara; Schreihofer, Derek A

2008-11-14

Estrogen is a powerful endogenous and exogenous neuroprotective agent in animal models of brain injury, including focal cerebral ischemia. Although this protection has been demonstrated in several different treatment and injury paradigms, it has not been demonstrated in focal cerebral ischemia induced by intraparenchymal endothelin-1 injection, a model with many advantages over other models of experimental focal ischemia. Reproductively mature female Sprague-Dawley rats were ovariectomized and divided into placebo and estradiol-treated groups. Two weeks later, halothane-anesthetized rats underwent middle cerebral artery (MCA) occlusion by interparenchymal stereotactic injection of the potent vasoconstrictor endothelin 1 (180pmoles/2microl) near the middle cerebral artery. Laser-Doppler flowmetry (LDF) revealed similar reductions in cerebral blood flow in both groups. Animals were behaviorally evaluated before, and 2 days after, stroke induction, and infarct size was evaluated. In agreement with other models, estrogen treatment significantly reduced infarct size evaluated by both TTC and Fluoro-Jade staining and behavioral deficits associated with stroke. Stroke size was significantly correlated with LDF in both groups, suggesting that cranial perfusion measures can enhance success in this model.

The neuroprotective effects of intravascular low level laser irradiation on cerebral ischemia rats

NASA Astrophysics Data System (ADS)

Qiu, Yongming; Lu, Zhaofeng; Wang, Zhongguang; Jiang, Jiyao

2005-07-01

The effects of intravascular low level laser irradiation of He-Ne on rat MCAo-induced cerebral injury were studied. The results showed that control rats (subjected to MCAo injury without laser treatment) at 7d exhibited striatal and cortical brain infarction in the right hemisphere from approximately 3 to 11mm from the front pole. the total infarct volume in this group was 34.5+/-8.1mm3. For experimental rats (with laser management), the total infarct volume was 29.0+/-9.0mm3. P was gained less than 0.05. The neurological score of control group was 4.7+/-0.6 and it was 5.2+/-1.0 in experimental group, comparison by statistical analysis showed P less than 0.05. The cerebral pathological damages in the control group were more severe than in experimental group. We concluded that the intravascular low level laser irradiation has no remarked complication and is helpful to reduce ischemic damage. There is clinically potential for the application of intravascular He-Ne low level laser irradiation in ischemia stroke.

Effects of transcranial direct current stimulation on hemichannel pannexin-1 and neural plasticity in rat model of cerebral infarction.

PubMed

Jiang, T; Xu, R X; Zhang, A W; Di, W; Xiao, Z J; Miao, J Y; Luo, N; Fang, Y N

2012-12-13

The aim of this study was to investigate the effects of transcranial direct current stimulation (TDCS) on hemichannel pannexin-1 (PX1) in cortical neurons and neural plasticity, and explore the optimal time window of TDCS therapy after stroke. Adult male Sprague-Dawley rats (n=90) were randomly assigned to sham operation, middle cerebral artery occlusion (MCAO), and TDCS groups, and underwent sham operation, unilateral middle cerebral artery (MCA) electrocoagulation, and unilateral MCA electrocoagulation plus TDCS (daily anodal and cathodal 10 Hz, 0.1 mA TDCS for 30 min beginning day 1 after stroke), respectively. Motor function was assessed using the beam walking test (BWT), and density of dendritic spines (DS) and PX1 mRNA expression were compared among groups on days 3, 7, and 14 after stroke. Effects of PX1 blockage on DS in hippocampal neurons after hypoxia-ischemia were observed. TDCS significantly improved motor function on days 7 and 14 after stroke as indicated by reduced BWT scores compared with the MCAO group. The density of DS was decreased after stroke; the TDCS group had increased DS density compared with the MCAO group on days 3, 7, and 14 (all P<0.0001). Cerebral infarction induced increased PX1 mRNA expression on days 3, 7, and 14 (P<0.0001), and the peak PX1 mRNA expression was observed on day 7. TDCS did not decrease the up-regulated PX1 mRNA expression after stroke on day 3, but did reduce the increased post-stroke PX1 mRNA expression on days 7 and 14 (P<0.0001). TDCS increased the DS density after stroke, indicating that it may promote neural plasticity after stroke. TDCS intervention from day 7 to day 14 after stroke demonstrated motor function improvement and can down-regulate the elevated PX1 mRNA expression after stroke. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

MORIN MITIGATES OXIDATIVE STRESS, APOPTOSIS AND INFLAMMATION IN CEREBRAL ISCHEMIC RATS

PubMed Central

Chen, Yanrong; Li, Yanke; Xu, Huali; Li, Gang; Ma, Yunxia; Pang, Yu Jun

2017-01-01

Background: Morin is a flavanoid which exhibits potent antioxidant activity in various oxidative stress related diseases. The current study was attempted to scrutinize the preclinical bio-efficacy of morin on focal ischemia. Methods: The animal model of focal cerebral ischemic injury was done by midbrain carotid artery occlusion (MCAO) method, followed by Morin (30mg/kg) administration for seven days. Results: The outcome of the study showed that treatment with morin displayed positive effects in reducing the focal cerebral ischemia. This effect was evident with the improvements in neurological deficits, reduction in MDA content and elevation of antioxidant levels (SOD, GSH and Gpx). Furthermore, protein expression of Bax and caspase-3 were effectively down-regulated, whilst the expression of Bcl-2 was significantly elevated. On the other hand, the mRNA expression of proinflammatory cytokines was significantly reduced in focal cerebral ischemic rats upon morin intervention. Conclusion: Thus, the beneficial effects of morin on cerebral ischemia assault may result from the reduction of oxidative stress, inhibition of apoptosis and inflammation. The neuroprotective effects of morin supplement may serve as potent adjuvant in the amelioration of ischemic stroke. PMID:28573251

Implications of Natural Occlusion of Ventilated Racks on Ammonia and Sanitation Practices

PubMed Central

Creamer, Michelle A; Petty, Joann; Martin, Tara; Bergdall, Valerie; Hickman-Davis, Judy M

2014-01-01

Examination of ventilated rat racks prior to semiannual sanitation revealed silicone nozzles and ventilation ports that were partially or completely occluded with granular debris. We subsequently sought to document performance standards for rack sanitation and investigate the effect of ventilation port occlusion on rack function and animal husbandry practices. We hypothesized that individually ventilated cages with occluded airflow would require more frequent cage changes, comparable to those for static cages (that is, every 3 to 4 d). Sprague–Dawley rats were housed under one of 4 conditions: no airflow occlusion, occluded air-supply inlet, occluded air-exhaust outlet, and occlusion of both inlet and outlet. Cages were changed when daily ammonia concentration exceeded 20 ppm or after 14 d had elapsed. Most cages with unoccluded or partial airflow occlusion remained below the 20 ppm limit until day 12 or 13. Cages with occlusion of both inlet and outlet exceeded 20 ppm ammonia by as early as day 5. Airflow was significantly lower in cages with occlusion of both inlet and outlet airflow. Weekly inspection revealed that occlusion of ventilation ports was detectable by 3 mo after semiannual sanitation. This study demonstrates that silicone nozzles should be removed prior to rack sanitation to improve the effectiveness of cleaning ventilation ports and nozzles. While the rack is in use, silicone nozzles and ventilation ports should be inspected regularly to identify occlusion that is likely to diminish environmental quality in the cage. Intracage ammonia levels are significantly higher when both inlet and outlet airflow are occluded. PMID:24602544

Implications of natural occlusion of ventilated racks on ammonia and sanitation practices.

PubMed

Creamer, Michelle A; Petty, Joann; Martin, Tara; Bergdall, Valerie; Hickman-Davis, Judy M

2014-03-01

Examination of ventilated rat racks prior to semiannual sanitation revealed silicone nozzles and ventilation ports that were partially or completely occluded with granular debris. We subsequently sought to document performance standards for rack sanitation and investigate the effect of ventilation port occlusion on rack function and animal husbandry practices. We hypothesized that individually ventilated cages with occluded airflow would require more frequent cage changes, comparable to those for static cages (that is, every 3 to 4 d). Sprague-Dawley rats were housed under one of 4 conditions: no airflow occlusion, occluded air-supply inlet, occluded air-exhaust outlet, and occlusion of both inlet and outlet. Cages were changed when daily ammonia concentration exceeded 20 ppm or after 14 d had elapsed. Most cages with unoccluded or partial airflow occlusion remained below the 20 ppm limit until day 12 or 13. Cages with occlusion of both inlet and outlet exceeded 20 ppm ammonia by as early as day 5. Airflow was significantly lower in cages with occlusion of both inlet and outlet airflow. Weekly inspection revealed that occlusion of ventilation ports was detectable by 3 mo after semiannual sanitation. This study demonstrates that silicone nozzles should be removed prior to rack sanitation to improve the effectiveness of cleaning ventilation ports and nozzles. While the rack is in use, silicone nozzles and ventilation ports should be inspected regularly to identify occlusion that is likely to diminish environmental quality in the cage. Intracage ammonia levels are significantly higher when both inlet and outlet airflow are occluded.

Caspase-Independent Apoptosis Induced by Reperfusion Following Ischemia without Bile Duct Occlusion in Rat Liver.

PubMed

Matsui, Nobuaki; Yoshioka, Rie; Nozawa, Asako; Kobayashi, Naonobu; Shichijo, Yukari; Yoshikawa, Tadatoshi; Akagi, Masaaki

2017-01-01

The contribution of caspases to hepatic ischemia/reperfusion (I/R)-induced apoptosis has not been completely understood yet. Several studies have demonstrated increased caspase activity during I/R and the protective effect of caspase inhibitors against I/R injuries. However, reports with opposing results also exist. Herein, we examined the contribution of caspases to the I/R-induced hepatic apoptosis in rats using caspase inhibitors and specific substrates of caspases. Hepatic I/R was induced via a 2-h occlusion of the portal vein and the hepatic artery, without conducting bile duct occlusion. DNA laddering and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling (TUNEL)-positive cells were increased at 3 h after reperfusion. Pretreatment with caspase inhibitors (Z-Asp-2,6-dichlorobenzoyloxymethylketone (Z-Asp-cmk) 2 or 10 mg/kg intravenously (i.v.), 20 mg/kg intraperitoneally (i.p.), Z-Val-Ala-Asp(OMe)-fluoromethylketone (Z-VAD-fmk) 3 mg/kg i.v.) failed to reduce apoptosis induced by I/R. Interestingly, apoptosis induced by the portal triad (hepatic artery, portal vein, and bile duct) occlusion/reperfusion could be marginally attenuated using Z-Asp-cmk (2 mg/kg i.v.). The cleavage activity for Ac-DEVD-α-(4-methylcoumaryl-7-amide) (MCA), a caspase-3/7/8/9 substrate, was significantly increased by I/R. Conversely, the cleavage activities for Ac-DNLD-MCA and MCA-VDQVDGW[K-DNP]-NH 2 , specific substrates for caspase-3 and -7 respectively, were decreased by I/R. Protein expression of the cellular inhibitor of apoptosis protein 2 (c-IAP2), an endogenous caspase inhibitor, was increased by ischemia. Nuclear translocation of the apoptosis-inducing factor (AIF), an initiator protein of caspase-independent apoptosis, was also increased during I/R. These results suggest that caspases are inhibited by c-IAP2 induced during ischemia and that AIF may be involved in initiation of apoptosis induced by hepatic I/R without

Identification of proteins in hyperglycemia and stroke animal models.

PubMed

Sung, Jin-Hee; Shah, Fawad-Ali; Gim, Sang-Ah; Koh, Phil-Ok

2016-01-01

Stroke is a major cause of disability and death in adults. Diabetes mellitus is a metabolic disorder that strongly increases the risk of severe vascular diseases. This study compared changes in proteins of the cerebral cortex during ischemic brain injury between nondiabetic and diabetic animals. Adult male rats were injected with streptozotocin (40 mg/kg) via the intraperitoneal route to induce diabetes and underwent surgical middle cerebral artery occlusion (MCAO) 4 wk after streptozotocin treatment. Cerebral cortex tissues were collected 24 h after MCAO and cerebral cortex proteins were analyzed by two-dimensional gel electrophoresis and mass spectrometry. Several proteins were identified as differentially expressed between nondiabetic and diabetic animals. Among the identified proteins, we focused on the following metabolism-related enzymes: isocitrate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, adenosylhomocysteinase, pyruvate kinase, and glucose-6-phosphate isomerase (neuroleukin). Expression of these proteins was decreased in animals that underwent MCAO. Moreover, protein expression was reduced to a greater extent in diabetic animals than in nondiabetic animals. Reverse transcription-polymerase chain reaction analysis confirmed that the diabetic condition exacerbates the decrease in expression of metabolism-related proteins after MCAO. These results suggest that the diabetic condition may exacerbate brain damage during focal cerebral ischemia through the downregulation of metabolism-related proteins. Copyright © 2016 Elsevier Inc. All rights reserved.

Human Recombinant Peptide Sponge Enables Novel, Less Invasive Cell Therapy for Ischemic Stroke

PubMed Central

Miyamoto, Michiyuki; Yamauchi, Tomohiro; Kawabori, Masahito; Osanai, Toshiya; Sasaki, Tasuku; Houkin, Kiyohiro; Kuroda, Satoshi

2018-01-01

Bone marrow stromal cell (BMSC) transplantation has the therapeutic potential for ischemic stroke. However, it is unclear which delivery routes would yield both safety and maximal therapeutic benefits. We assessed whether a novel recombinant peptide (RCP) sponge, that resembles human collagen, could act as a less invasive and beneficial scaffold in cell therapy for ischemic stroke. BMSCs from green fluorescent protein-transgenic rats were cultured and Sprague–Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAo). A BMSC-RCP sponge construct was transplanted onto the ipsilateral intact neocortex 7 days after MCAo. A BMSC suspension or vehicle was transplanted into the ipsilateral striatum. Rat motor function was serially evaluated and histological analysis was performed 5 weeks after transplantation. The results showed that BMSCs could proliferate well in the RCP sponge and the BMSC-RCP sponge significantly promoted functional recovery, compared with the vehicle group. Histological analysis revealed that the RCP sponge provoked few inflammatory reactions in the host brain. Moreover, some BMSCs migrated to the peri-infarct area and differentiated into neurons in the BMSC-RCP sponge group. These findings suggest that the RCP sponge may be a promising candidate for animal protein-free scaffolds in cell therapy for ischemic stroke in humans. PMID:29765415

Human Recombinant Peptide Sponge Enables Novel, Less Invasive Cell Therapy for Ischemic Stroke.

PubMed

Miyamoto, Michiyuki; Nakamura, Kentaro; Shichinohe, Hideo; Yamauchi, Tomohiro; Ito, Masaki; Saito, Hisayasu; Kawabori, Masahito; Osanai, Toshiya; Sasaki, Tasuku; Houkin, Kiyohiro; Kuroda, Satoshi

2018-01-01

Bone marrow stromal cell (BMSC) transplantation has the therapeutic potential for ischemic stroke. However, it is unclear which delivery routes would yield both safety and maximal therapeutic benefits. We assessed whether a novel recombinant peptide (RCP) sponge, that resembles human collagen, could act as a less invasive and beneficial scaffold in cell therapy for ischemic stroke. BMSCs from green fluorescent protein-transgenic rats were cultured and Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAo). A BMSC-RCP sponge construct was transplanted onto the ipsilateral intact neocortex 7 days after MCAo. A BMSC suspension or vehicle was transplanted into the ipsilateral striatum. Rat motor function was serially evaluated and histological analysis was performed 5 weeks after transplantation. The results showed that BMSCs could proliferate well in the RCP sponge and the BMSC-RCP sponge significantly promoted functional recovery, compared with the vehicle group. Histological analysis revealed that the RCP sponge provoked few inflammatory reactions in the host brain. Moreover, some BMSCs migrated to the peri-infarct area and differentiated into neurons in the BMSC-RCP sponge group. These findings suggest that the RCP sponge may be a promising candidate for animal protein-free scaffolds in cell therapy for ischemic stroke in humans.

Electroacupuncture preconditioning-induced neuroprotection may be mediated by glutamate transporter type 2

PubMed Central

Zhu, Xiaoling; Yin, Jinbo; Li, Liaoliao; Ma, Lei; Tan, Hongying; Deng, Jiao; Chen, Shaoyang; Zuo, Zhiyi

2013-01-01

Electroacupuncture has been shown to induce a preconditioning effect in the brain. The mechanisms for this protection are not fully elucidated. We hypothesize that this protection is mediated by excitatory amino acid transporters (EAATs) that have been shown to be neuroprotective. To test this hypothesis, two-month old male Sprague-Dawley rats and EAAT type 3 (EAAT3) knockout mice received or did not receive 30-min electroacupuncture once a day for 5 consecutive days. They were subjected to a 120-min middle cerebral arterial occlusion (MCAO) at 24 h after the last electroacupuncture. Neurological outcome was assessed 2 days after the MCAO. Brain tissues were harvested at 24 h after the last electroacupuncture for Western blotting. Rats subjected to electroacupuncture at the Baihui acupoint had smaller brain infarct volumes and better neurological deficit scores than control rats. Electroacupuncture increased EAAT type 2 (EAAT2) in the cerebral cortex, tended to increase EAAT3 in the hippocampus, and had no effect on EAAT type 1 expression. Dihydrokainate, an EAAT2 inhibitor, worsened the neurological outcome of rats with electroacupuncture pretreatment. Electroacupuncture pretreatment at the Baihui acupoint increased EAAT2 in the cerebral cortex and improved the neurological outcome of EAAT3 knockout mice. Together, our results suggest that EAAT2 may mediate the electroacupuncture preconditioning-induced neuroprotection. PMID:23831620

Electroacupuncture preconditioning-induced neuroprotection may be mediated by glutamate transporter type 2.

PubMed

Zhu, Xiaoling; Yin, Jinbo; Li, Liaoliao; Ma, Lei; Tan, Hongying; Deng, Jiao; Chen, Shaoyang; Zuo, Zhiyi

2013-10-01

Electroacupuncture has been shown to induce a preconditioning effect in the brain. The mechanisms for this protection are not fully elucidated. We hypothesize that this protection is mediated by excitatory amino acid transporters (EAATs) that have been shown to be neuroprotective. To test this hypothesis, two-month old male Sprague-Dawley rats and EAAT type 3 (EAAT3) knockout mice received or did not receive 30-min electroacupuncture once a day for five consecutive days. They were subjected to a 120-min middle cerebral arterial occlusion (MCAO) at 24h after the last electroacupuncture. Neurological outcome was assessed 2days after the MCAO. Brain tissues were harvested at 24h after the last electroacupuncture for Western blotting. Rats subjected to electroacupuncture at the Baihui acupoint had smaller brain infarct volumes and better neurological deficit scores than control rats. Electroacupuncture increased EAAT type 2 (EAAT2) in the cerebral cortex, tended to increase EAAT3 in the hippocampus, and had no effect on EAAT type 1 expression. Dihydrokainate, an EAAT2 inhibitor, worsened the neurological outcome of rats with electroacupuncture pretreatment. Electroacupuncture pretreatment at the Baihui acupoint increased EAAT2 in the cerebral cortex and improved the neurological outcome of EAAT3 knockout mice. Together, our results suggest that EAAT2 may mediate the electroacupuncture preconditioning-induced neuroprotection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Design of a noninvasive face mask for ocular occlusion in rats and assessment in a visual discrimination paradigm.

PubMed

Hager, Audrey M; Dringenberg, Hans C

2012-12-01

The rat visual system is structured such that the large (>90 %) majority of retinal ganglion axons reach the contralateral lateral geniculate nucleus (LGN) and visual cortex (V1). This anatomical design allows for the relatively selective activation of one cerebral hemisphere under monocular viewing conditions. Here, we describe the design of a harness and face mask allowing simple and noninvasive monocular occlusion in rats. The harness is constructed from synthetic fiber (shoelace-type material) and fits around the girth region and neck, allowing for easy adjustments to fit rats of various weights. The face mask consists of soft rubber material that is attached to the harness by Velcro strips. Eyeholes in the mask can be covered by additional Velcro patches to occlude either one or both eyes. Rats readily adapt to wearing the device, allowing behavioral testing under different types of viewing conditions. We show that rats successfully acquire a water-maze-based visual discrimination task under monocular viewing conditions. Following task acquisition, interocular transfer was assessed. Performance with the previously occluded, "untrained" eye was impaired, suggesting that training effects were partially confined to one cerebral hemisphere. The method described herein provides a simple and noninvasive means to restrict visual input for studies of visual processing and learning in various rodent species.

Neuroprotective effect of curcumin on transient focal cerebral ischemia in rats.

PubMed

Zhao, Jing; Zhao, Yong; Zheng, Weiping; Lu, Yuyu; Feng, Gang; Yu, Shanshan

2008-09-10

Curcumin, a member of the curcuminoid family of compounds, is a yellow colored phenolic pigment obtained from the powdered rhizome of C. longa Linn. Recent studies have demonstrated that curcumin has protective effects against cerebral ischemia/reperfusion injury. However, little is known about its mechanism. Hence, in the present study the neuroprotective potential of curcumin was investigated in middle cerebral artery occlusion (MCAO) induced focal cerebral IR injury. Administration of curcumin 100 and 300 mg/kg i.p. 60 min after MCAO significantly diminished infarct volume, and improved neurological deficit in a dose-dependent manner. Nissl staining showed that the neuronal injury was significantly improved after being treated with curcumin. Curcumin significantly decreased the expression of caspase-3 protein. A higher number of TUNEL-positive cells were found in the vehicle group, but they were significantly decreased in the treated group. Taken together, these results suggest that the neuroprotective potentials of curcumin against focal cerebral ischemic injury are, at least in part, ascribed to its anti-apoptotic effects.

Overexpression of caveolin-1 attenuates brain edema by inhibiting tight junction degradation.

PubMed

Choi, Kang-Ho; Kim, Hyung-Seok; Park, Man-Seok; Lee, Eun-Bin; Lee, Jung-Kil; Kim, Joon-Tae; Kim, Ja-Hae; Lee, Min-Cheol; Lee, Hong-Joon; Cho, Ki-Hyun

2016-10-18

Cerebral edema from the disruption of the blood-brain barrier (BBB) after cerebral ischemia is a major cause of morbidity and mortality as well as a common event in patients with stroke. Caveolins (Cavs) are thought to regulate BBB functions. Here, we report for the first time that Cav-1 overexpression (OE) decreased brain edema from BBB disruption following ischemic insult. Edema volumes and Cav-1 expression levels were measured following photothrombosis and middle cerebral artery occlusion (MCAO). Endothelial cells that were transduced with a Cav-1 lentiviral expression vector were transplanted into rats. BBB permeability was quantified with Evans blue extravasation. Edema volume was determined from measures of the extravasation area, brain water content, and average fluorescence intensity after Cy5.5 injections. Tight junction (TJ) protein expression was measured with immunoblotting. Cav-1 expression levels and vasogenic brain edema correlated strongly after ischemic insult. Cav-1 expression and BBB disruption peaked 3 d after the MCAO. In addition, intravenous administration of endothelial cells expressing Cav-1 effectively increased the Cav-1 levels 3 d after the MCAO ischemic insult. Importantly, Cav-1 OE ameliorated the vasogenic edema by inhibiting the degradation of TJ protein expression in the acute phase of ischemic stroke. These results suggested that Cav-1 OE protected the integrity of the BBB mainly by preventing the degradation of TJ proteins in rats. These findings need to be confirmed in a clinical setting in human subjects.

Bone marrow stromal cells promote neuroplasticity of cerebral ischemic rats via a phosphorylated CRMP2-mediated mechanism.

PubMed

He, Xiang; Jiang, Ling; Dan, Qi-Qin; Lv, Qiang; Hu, Yue; Liu, Jia; Wang, Shu-Fen; Wang, Ting-Hua

2017-03-01

Collapsin response mediator protein 2 (CRMP2), an important protein involved in axonal growth and the maintenance of neuronal membrane integrity, has proved to be altered in nervous system diseases. This study was aimed to investigate the role of CRMP2 in bone marrow stromal cells (BMSCs) treating rats with cerebral ischemia. BMSCs were isolated from shaft of the femurs, tibiae, and humeri and were intra-carotid administrated immediately after middle cerebral artery occlusion (MCAO). Modified Neurological Severity Scores (mNSS) was conducted at 3, 7, 14dpo and the electrophysiologic evaluation was evaluated at 14dpo. Then all rats were sacrificed and brain tissues were harvested for RT-PCR, Western blot and Immunohistochemistry analysis. We found BMSCs treatment significantly improved the neurobehavioral performance impaired by ischemic brain injury, accompanied with the notably increasing levels of Synaptophysin (SYP) and Growth associated protein 43 (GAP43). We also found the protein level of phosphorylated CRMP2 (p-CRMP2) and phosphorylation-mediated protein including Glycogen synthase kinase 3 Beta (GSK3β), Cyclin-dependent kinase 5 (CDK5) were dramatically downregulated in ischemic rats following BMSCs transplant. Furthermore, the GSK3β-mediated factors including neurotrophic and signaling factors were all significantly upregulated in BMSCs-treated group. On the basis of these findings, we suggest that the neuroplasticity effect of BMSCs on cerebral ischemia may be associated with the phosphorylated modulation of CRMP2. Copyright © 2016 Elsevier B.V. All rights reserved.

Mulberry Fruit Extract Protects against Memory Impairment and Hippocampal Damage in Animal Model of Vascular Dementia

PubMed Central

Kaewkaen, Pratchaya; Tong-un, Terdthai; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Kaewrueng, Wiroje; Wongcharoenwanakit, Sathaporn

2012-01-01

Nowadays, the preventive strategy of vascular dementia, one of the challenge problems of elderly, has received attention due to the limitation of therapeutic efficacy. In this study, we aimed to determine the protective effect and possible mechanism of action of mulberry fruit extract on memory impairment and brain damage in animal model of vascular dementia. Male Wistar rats, weighing 300–350 g, were orally given mulberry extract at doses of 2, 10 and 50 mg/kg at a period of 7 days before and 21 days after the occlusion of right middle cerebral artery (Rt.MCAO). It was found that rats subjected to mulberry fruits plus Rt.MCAO showed the enhanced memory, the increased densities of neuron, cholinergic neuron, Bcl-2-immunopositive neuron together with the decreased oxidative stress in hippocampus. Taken all data together, the cognitive enhancing effect of mulberry fruit extract observed in this study might be partly associated with the increased cholinergic function and its neuroprotective effect in turn occurs partly via the decreased oxidative stress and apoptosis. Therefore, mulberry fruit is the potential natural cognitive enhancer and neuroprotectant. However, further researches are essential to elucidate the possible active ingredient. PMID:22952555

Involvement of arterial baroreflex in the protective effect of dietary restriction against stroke

PubMed Central

Liu, Ai-Jun; Guo, Jin-Min; Liu, Wei; Su, Feng-Yun; Zhai, Qi-Wei; Mehta, Jawahar L; Wang, Wei-Zhong; Su, Ding-Feng

2013-01-01

Dietary restriction (DR) protects against neuronal dysfunction and degeneration, and reduces the risk of ischemic stroke. This study examined the role of silent information regulator T1 (SIRT1) and arterial baroreflex in the beneficial effects of DR against stroke, using two distinct stroke models: stroke-prone spontaneously hypertensive rats (SP-SHRs) and Sprague-Dawley (SD) rats with middle cerebral artery occlusion (MCAO). Sirt1 knockout (KO) mice were used to examine the involvement of sirt1. Sinoaortic denervation was used to inactivate arterial baroreflex. Dietary restriction was defined as 40% reduction of dietary intake. Briefly, DR prolonged the life span of SP-SHRs and reduced the infarct size induced by MCAO. Dietary restriction also improved the function arterial baroreflex, decreased the release of proinflammatory cytokines, and reduced end-organ damage. The beneficial effect of DR on stroke was markedly attenuated by blunting arterial baroreflex. Lastly, the infarct area in sirt1 KO mice was significantly larger than in the wild-type mice. However, the beneficial effect of DR against ischemic injury was still apparent in sirt1 KO mice. Accordingly, arterial baroreflex, but not sirt1, is important in the protective effect of DR against stroke. PMID:23443169

Diabetes synergistically exacerbates poststroke dementia and tau abnormality in brain.

PubMed

Zhang, Ting; Pan, Bai-Shen; Sun, Guang-Chun; Sun, Xiao; Sun, Feng-Yan

2010-07-01

This study investigated whether exacerbation of poststroke dementia by diabetes associated abnormal tau phosphorylation and its mechanism. Streptozotocin (STZ) injection and/or a high fat diet (HFD) were used to treat rats to induce type 1 and 2 diabetes. Animals were randomly divided into STZ, HFD, STZ-HFD, and normal diet (NPD) groups. Focal ischemic stroke was induced by middle cerebral artery occlusion (MCAO). Cognitive function was tested by the Morris water maze. STZ or STZ-HFD treatment exacerbated ischemia-induced cognitive deficits, brain infarction and reduction of synaptophysin expression. Moreover, we found that diabetes further increased AT8, a marker of hyperphosphorylated tau, protein and immunopositive stained cells in the hippocampus of rats following MCAO while reduced the level of phosphorylated glycogen synthase kinase 3-beta at serine-9 residues (p-ser9-GSK-3beta), indicating activation of GSK-3beta. We conclude that diabetes further deteriorates ischemia-induced brain damage and cognitive deficits which may be associated with abnormal phosphorylation of tau as well as activation of GSK-3beta. These findings may be helpful for developing new strategies to prevent/delay formation of poststroke dementia in patients with diabetes. 2010 Elsevier Ltd. All rights reserved.

Middle-aged, but not young, rats develop cognitive impairment and cortical neurodegeneration following the four-vessel occlusion/internal carotid artery model of chronic cerebral hypoperfusion.

PubMed

Ferreira, Emilene D Fiuza; Romanini, Cássia V; Mori, Marco A; de Oliveira, Rúbia M Weffort; Milani, Humberto

2011-10-01

Permanent, stepwise occlusion of the vertebral arteries (VAs) and internal carotid arteries (ICAs) following the sequence VA→ICA→ICA, with an interstage interval (ISI, →) of 7 days, has been investigated as a four-vessel occlusion (4-VO)/ICA model of chronic cerebral hypoperfusion. This model has the advantage of not causing retinal damage. In young rats, however, 4-VO/ICA with an ISI of 7 days fails to cause behavioral sequelae. We hypothesized that such a long ISI would allow the brain to efficiently compensate for cerebral hypoperfusion, preventing the occurrence of cognitive impairment and neurodegeneration. The present study evaluated whether brain neurodegeneration and learning/memory deficits can be expressed by reducing the length of the ISI and whether aging influences the outcome. Young, male Wistar rats were subjected to 4-VO/ICA with different ISIs (5, 4, 3 or 2 days). An ISI of 4 days was used in middle-aged rats. Ninety days after 4-VO/ICA, the rats were tested for learning/memory impairment in a modified radial maze and then examined for neurodegeneration of the hippocampus and cerebral cortex. Regardless of the ISI, young rats were not cognitively impaired, although hippocampal damage was evident. Learning/memory deficits and hippocampal and cortical neurodegeneration occurred in middle-aged rats. The data indicate that 4-VO/ICA has no impact on the capacity of young rats to learn the radial maze task, despite 51% hippocampal cell death. Such resistance is lost in middle-aged animals, for which the most extensive neurodegeneration observed in both the hippocampus and cerebral cortex may be responsible. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Plasma Exosomal miRNA-122-5p and miR-300-3p as Potential Markers for Transient Ischaemic Attack in Rats.

PubMed

Li, Dong-Bin; Liu, Jing-Li; Wang, Wei; Luo, Xiu-Mei; Zhou, Xia; Li, Jin-Pin; Cao, Xiao-Li; Long, Xiao-Hong; Chen, Jia-Gui; Qin, Chao

2018-01-01

Background: Differentiation of transient ischaemic attack (TIA) from ischaemic stroke within the thrombolysis time window is difficult. Although TIA may be diagnosed within this window, the latest imaging technologies are complex and costly. Serum markers, which are non-invasive, rapid and economic, are used for diagnosis and prognosis of various diseases. Exosome-derived miRNA markers for TIA are unknown. Methods: We examined focal brain ischaemia produced by occlusion of the middle cerebral artery (MCAo) for 5 min, 10 min, and 2 h in rats. Exosomal miRNAs with consistent trends in cerebrospinal fluid (CSF) and plasma were identified by deep sequencing and quantitative real-time polymerase chain reaction (qRT-PCR). The areas under the curve (AUC) of the receiver operating characteristic (ROC) curve were used to evaluate the diagnostic accuracy of these miRNAs for TIA in rats. Results: Rno-miR-122-5p and rno-miR-300-3p were selected. Plasma exosomal rno-miR-122-5p was significantly downregulated in 10 min ischaemic rats compared with control and 5 min plasma. Plasma exosomal rno-miR-300-3p was significantly upregulated in 5 min ischaemic rats compared with control, 10 min and 2 h rats. Plasma and CSF levels of these miRNAs were correlated. ROC analysis showed high AUC values for rno-miR-122-5p (0.960) and rno-miR-300-3p (0.970) in the 10 and 5 min rats, respectively, compared with controls. Conclusions: Plasma exosomal rno-miR-122-5p and rno-miR-300-3p may be blood-based TIA biomarkers.

Characterization of the rat cerebrospinal fluid proteome following acute cerebral ischemia using an aptamer-based proteomic technology.

PubMed

Simats, Alba; García-Berrocoso, Teresa; Ramiro, Laura; Giralt, Dolors; Gill, Natalia; Penalba, Anna; Bustamante, Alejandro; Rosell, Anna; Montaner, Joan

2018-05-21

The limited accessibility to the brain has turned the cerebrospinal fluid (CSF) into a valuable source that may contribute to the complete understanding of the stroke pathophysiology. Here we have described the CSF proteome in the hyper-acute phase of cerebral ischemia by performing an aptamer-based proteomic assay (SOMAscan) in CSF samples collected before and 30 min after male Wistar rats had undergone a 90 min Middle Cerebral Artery Occlusion (MCAO) or sham-surgery. Proteomic results indicated that cerebral ischemia acutely increased the CSF levels of 716 proteins, mostly overrepresented in leukocyte chemotaxis and neuronal death processes. Seven promising candidates were further evaluated in rat plasma and brain (CKB, CaMK2A, CaMK2B, CaMK2D, PDXP, AREG, CMPK). The 3 CaMK2 family-members and CMPK early decreased in the infarcted brain area and, together with AREG, co-localized with neurons. Conversely, CKB levels remained consistent after the insult and specifically matched with astrocytes. Further exploration of these candidates in human plasma revealed the potential of CKB and CMPK to diagnose stroke, while CaMK2B and CMPK resulted feasible biomarkers of functional stroke outcome. Our findings provided insights into the CSF proteome following cerebral ischemia and identified new outstanding proteins that might be further considered as potential biomarkers of stroke.

Synthesis and biological evaluation of pyrrolidine derivatives as novel and potent sodium channel blockers for the treatment of ischemic stroke.

PubMed

Seki, Maki; Tsuruta, Osamu; Tatsumi, Ryo; Soejima, Aki

2013-07-15

A novel series of pyrrolidine derivatives as Na(+) channel blockers was synthesized and evaluated for their inhibitory effects on neuronal Na(+) channels. Structure-activity relationship (SAR) studies of a pyrrolidine analogue 2 led to the discovery of 5e as a potent Na(+) channel blocker with a low inhibitory action against human ether-a-go-go-related gene (hERG) channels. Compound 5e showed remarkably neuroprotective activity in a rat transient middle cerebral artery occlusion (MCAO) model, suggesting that 5e would act as a neuroprotectant for ischemic stroke. Copyright © 2013 Elsevier Ltd. All rights reserved.

IMM-H004, A New Coumarin Derivative, Improved Focal Cerebral Ischemia via Blood-Brain Barrier Protection in Rats.

PubMed

Niu, Fei; Song, Xiu-Yun; Hu, Jin-Feng; Zuo, Wei; Kong, Ling-Lei; Wang, Xiao-Feng; Han, Ning; Chen, Nai-Hong

2017-10-01

IMM-H004 (7-hydroxy-5-methoxy-4-methyl-3-[4-methylpiperazin-1-yl]-2H-chromen-2-one) is a novel coumarin derivative that showed better effect in improving global cerebral ischemia in rats. However, the effects and mechanisms in focal cerebral ischemia were not clear. Blood-brain barrier (BBB) protection is a vital strategy for the treatment of cerebral ischemia. This study is to investigate whether IMM-H004 improves brain ischemia injury via BBB protection. Focal brain ischemia model was induced by middle cerebral artery occlusion for 1 hour and reperfusion (MCAO/R) for 24 hours in rats. IMM-H004 (1.5, 3, 6 mg/kg) and edaravone (positive drug, 6 mg/kg) were administered after 5 minutes of occlusion. Neurological score and TTC staining were used to evaluate the effect of IMM-H004. Evans Blue (EB) staining and electron microscopy were used to assess BBB permeability. Western blot, reverse transcription-polymerase chain reaction, and immunohistochemistry were used to detect the expression of BBB structure-related proteins. Compared with the model group, IMM-H004 in the focal brain ischemia model improved neurological function and reduced cerebral infarction size and edema content. IMM-H004 sharply reduced the EB content and alleviated BBB structure. In addition, IMM-H004 increased the level of zonula occludens (ZO-1) and occluding, decreased the level of aquaporin 4 and matrix metalloproteinase 9, either in cortex or in hippocampus. And all of these changed were related to BBB protection. IMM-H004 improved cerebral ischemia injury via BBB protection. For a potential therapy drug of cerebral ischemia, IMM-H004 merits further study. Copyright © 2017. Published by Elsevier Inc.

Gastrodia and Uncaria (tianma gouteng) water extract exerts antioxidative and antiapoptotic effects against cerebral ischemia in vitro and in vivo.

PubMed

Xian, Jia Wen; Choi, Angus Yiu-Ting; Lau, Clara Bik-San; Leung, Wing Nang; Ng, Chun Fai; Chan, Chun Wai

2016-01-01

Gastrodia and Uncaria decoction (tianma gouteng yin) is commonly used in Chinese medicine to treat cerebral ischemia. The aim of this study was to investigate the neuroprotective effects of a water extract (GUW) of Gastrodia elata (tianma; GE) and Uncaria rhynchophylla (gouteng; UR) against ischemic insult using oxygen-glucose-deprived neuronal differentiated PC12 cells and rats subjected to middle cerebral artery occlusion (MCAO). GUW was prepared by boiling raw GE and UR in water, followed by the lyophilization of the resulting extract. Neuronal differentiated PC12 cells were subjected to oxygen-glucose deprivation with or without GUW. The neuroprotective effects of GUW were compared with those of the corresponding GE and UR extracts to tease apart the effects of the different herbs. The synergistic effect of GE and UR in GUW was measured using a modified version of Burgi's formulae. The neuroprotective mechanisms via Nrf2 and anti-apoptotic pathways were investigated using real time PCR and enzyme activity assays. The neuroprotective effects of GUW were studied in vivo using a rat MCAO model. Neurofunctional outcome and brain infarct volume we assessed. H&E staining, cresyl violet staining and immunohistochemistry were performed to assess the histological outcome. The results of lactate dehydrogenase assay showed that GUW protected cells in a concentration-dependent manner (P < 0.001). Moreover, the neuroprotective effects of GUW were greater than those of GE + UR (P = 0.018). Burgi's formula showed that the herbs in GUW acted synergistically to protect cells from ischemic injury. GUW significantly upregulated Bcl-2 expression (P = 0.0130) and reduced caspase-3 activity by 60 % (P < 0.001). GUW upregulated Nrf-2 expression (P = 0.0066) and the antioxidant response element pathway genes. The infarct volume was reduced by 55 % at day 7 of reperfusion (P < 0.001), and significant improvements were observed in the neurological deficit score and beam

Talampanel improves the functional deficit after transient focal cerebral ischemia in rats. A 30-day follow up study.

PubMed

Erdo, Franciska; Berzsenyi, Pál; Német, László; Andrási, Ferenc

2006-01-15

The neuroprotective effect of talampanel, a negative allosteric modulator of alpha-amino-3-hydroxy-methyl-4-isoxazolyl-propionic acid (AMPA) receptors has been described previously. However, in these studies the histological changes and not the functional consequences of the brain damage were evaluated. The aim of present investigation was to analyze the sensorimotor function after stroke and to test the influence of talampanel (GYKI-53773, LY-300164) by 30-day monitoring in rats. After 1h middle cerebral artery occlusion (MCAO) general 'well-being', neurological status, spontaneous motor activity, rotation, motor coordination, balancing, muscle strength and reaction time were followed for 1 month. Talampanel (6 x 10 mg/kg i.p. given on the day of stroke) improved the motor coordination in rotarod (p < 0.01) and beam walking (p < 0.01) tests, reduced the number of stroke-induced rotations (p < 0.05), shortened the reflex time on the forelimb contralateral to brain ischemia and improved the survival rate comparing with vehicle treated control. After stroke, serious sensorimotor deficits appeared in rats but they showed partial spontaneous recovery after 30 days. Talampanel treatment enhanced the rate of functional improvement without changing the morphology at the end of the experiment. Our results indicate that modulation of AMPA receptors by talampanel can be a promising therapeutic approach to the treatment of stroke.

Inhibition of Aquaporin-4 Improves the Outcome of Ischaemic Stroke and Modulates Brain Paravascular Drainage Pathways.

PubMed

Pirici, Ionica; Balsanu, Tudor Adrian; Bogdan, Catalin; Margaritescu, Claudiu; Divan, Tamir; Vitalie, Vacaras; Mogoanta, Laurentiu; Pirici, Daniel; Carare, Roxana Octavia; Muresanu, Dafin Fior

2017-12-23

Aquaporin-4 (AQP4) is the most abundant water channel in the brain, and its inhibition before inducing focal ischemia, using the AQP4 inhibitor TGN-020, has been showed to reduce oedema in imaging studies. Here, we aimed to evaluate, for the first time, the histopathological effects of a single dose of TGN-020 administered after the occlusion of the medial cerebral artery (MCAO). On a rat model of non-reperfusion ischemia, we have assessed vascular densities, albumin extravasation, gliosis, and apoptosis at 3 and 7 days after MCAO. TGN-020 significantly reduced oedema, glial scar, albumin effusion, and apoptosis, at both 3 and 7 days after MCAO. The area of GFAP-positive gliotic rim decreased, and 3D fractal analysis of astrocytic processes revealed a less complex architecture, possibly indicating water accumulating in the cytoplasm. Evaluation of the blood vessels revealed thicker basement membranes colocalizing with exudated albumin in the treated animals, suggesting that inhibition of AQP4 blocks fluid flow towards the parenchyma in the paravascular drainage pathways of the interstitial fluid. These findings suggest that a single dose of an AQP4 inhibitor can reduce brain oedema, even if administered after the onset of ischemia, and AQP4 agonists/antagonists might be effective modulators of the paravascular drainage flow.

Nicotinamide attenuates the ischemic brain injury-induced decrease of Akt activation and Bad phosphorylation.

PubMed

Koh, Phil-Ok

2011-07-08

Nicotinamide protects cortical neuronal cells against cerebral ischemic injury through activation of various cytoprotective mechanisms. Here, this study confirmed the neuroprotective effects of nicotinamide in focal cerebral ischemic injury and investigated whether nicotinamide modulates a crucial survival pathway, Akt and its downstream targets. Adult male rats were treated with vehicle or nicotinamide (500 mg/kg) 2h after the onset of middle cerebral artery occlusion (MCAO). Brains were collected 24h after MCAO and infarct volumes were analyzed. Nicotinamide significantly reduced the infarct volume in the cerebral cortex. Potential activation was measured by phosphorylation of PDK1 at Ser(241), Akt at Ser(473), and Bad at Ser(136) using Western blot analysis. Nicotinamide prevented the injury-induced decrease of pPDK1, pAkt, and pBad levels. 14-3-3 levels were not different between vehicle- and nicotinamide-treated animals. However, pBad and 14-3-3 interaction levels decreased during MCAO, but were maintained in the presence of nicotinamide, compared to levels in control animals. These findings suggest that nicotinamide attenuates cell death due to focal cerebral ischemic injury and that neuroprotective effects are mediated through the Akt signaling pathway, thus enhancing neuronal survival. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Isoflurane reduces the ischemia reperfusion injury surge: a longitudinal study with MRI.

PubMed

Taheri, Saeid; Shunmugavel, Anandakumar; Clark, Danielle; Shi, Honglian

2014-10-24

Recent studies show neuroprotective benefits of isoflurane (ISO) administered during cerebral ischemia. However, the available studies evaluated cerebral injury only at a single time point following the intervention and thus the longitudinal effect of ISO on ischemic tissues remains to be investigated. The objective of the present study was to investigate the longitudinal effect of ISO treatment in counteracting the deleterious effect of ischemia by evoking the transcription factor, hypoxia inducible factor-1 (HIF-1), and vascular endothelial growth factor (VEGF). Focal cerebral ischemia was induced in 70 rats by filament medial cerebral artery occlusion (MCAo) method. MCAo rats were randomly assigned to control (90 min ischemia) and MCAo+ISO (90 min ischemia+2% ISO) groups. Infarct volume, edema, intracerebral hemorrhage (ICH), and regional cerebral blood flow (rCBF) were measured in eight in vivo sequential MR imaging sessions for 3 weeks. Western blot analysis and immunofluorescence were used to determine the expression level of HIF-1α (the regulatable subunit of HIF-1) and VEGF proteins. ISO inhalation during ischemia significantly decreased the surge of infarct volume, edema, ICH, and reduced the mortality rate (p<0.01). ISO transiently altered the rCBF, significantly enhanced the expression of HIF-1α and VEGF, and decreased the immune cell infiltration. Locomotor dysfunction was ameliorated at a significantly faster pace, and the benefit was seen to persist up to three weeks. Treatment with ISO during ischemia limits the deadly surge in the dynamics of ischemia reperfusion injury with no observed long-term inverse effect. Copyright © 2014 Elsevier B.V. All rights reserved.

Amelioration of cerebral infarction and improvement of neurological deficit by a Korean herbal medicine, modified Bo-Yang-Hwan-O-Tang.

PubMed

Choi, Yookeum; Kim, Seul-Ki; Choi, In-Young; Ju, Chung; Nam, Kung-Woo; Hwang, Sunyoung; Kim, Byung-Woo; Yoon, Min Ji; Won, Moo-Ho; Park, Yong-Ki; Kim, Won-Ki

2011-05-01

Modified Bo-Yang-Hwan-O-Tang (mBHT) is an improved herbal formula of BHT, which has been widely used to treat ischaemic stroke in East Asia, by the addition of five herbs having anti-ischaemic properties. In this study, we investigated whether mBHT would reduce cerebral ischaemic injury in rats. Sprague-Dawley rats were subjected to a 90-min middle cerebral artery occlusion (MCAO) and subsequent 22-h reperfusion. mBHT was administered either intraperitoneally twice 15 min before and 15 min after, or orally once 30 min or 120 min after the onset of MCAO (50 or 200 mg/kg each). Intraperitoneal administration of mBHT markedly reduced the cerebral infarct size and neurological deficit caused by MCAO/reperfusion. mBHT treatment also significantly improved long-term survival rate after cerebral ischaemic injury. Oral administration of mBHT 30 min after ischaemia also markedly reduced the infarct size after cerebral ischaemia. The anti-ischaemic effect of mBHT was significantly, but not fully, reduced when mBHT-induced hypothermia was abolished. In cultured cortical neurons, we further found that mBHT decreased oxygen-glucose deprivation/re-oxygenation-evoked neuronal injury by inhibiting production of reactive oxygen species, decrease in mitochondrial transmembrane potential, and activation of caspase-3. However, mBHT did not inhibit N-Methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity. Taken together, our data suggest that mBHT has multiple anti-ischaemic properties and would be a good therapeutic herbal prescription for the treatment of cerebral ischaemic stroke. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.

4'-O-β-D-Glucosyl-5-O-Methylvisamminol, A Natural Histone H3 Phosphorylation Epigenetic Suppressor, Exerts a Neuroprotective Effect Through PI3K/Akt Signaling Pathway on Focal Cerebral Ischemia in Rats.

PubMed

Chang, Chih-Zen; Wu, Shu-Chuan

2016-05-01

A bursting inflammation has been observed that compromises neurologic function in patients who experience stroke. We sought to examine the neuroprotective efficacy of 4'-O-β-D-glucosyl-5-O-methylvisamminol (OGOMV), a novel histone H3 phosphorylation epigenetic suppressor) in a transient middle cerebral artery occlusion (tMCAO). A rodent tMCAO model was used. Administration with 400 μg/kg/day OGOMV was initiated 12 hours before (prevention) and 1 hour after animals were subjected to tMCAO (reversal). The cerebral cortex was harvested to examine protein kinase B (PI3D/Akt), 5-bromo-2'-deoxyuridine (Western blot), and caspases (reverse-transcription polymerase chain reaction). In addition, cerebrospinal fluid samples were collected to examine interleukin 1-β, interleukin-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α (reverse-transcription polymerase chain reaction). Cortical 5-bromo-2'-deoxyuridine and phospho-PI3D/Akt were reduced in tMCAO animals, compared with the healthy controls but increased in the OGOMV treatment and prevention groups. Activated cortical caspase-3,-6, and -9a as well as increased IL-1β and TNF-α levels were observed in the tMCAO animals (P < 0.05). Both prevention and treatment with OGOMV significantly reduced cleaved caspase-3 and -9a groups, but no significant change in caspase-6 was noted. Perifosine, an Akt inhibitor, was added to reduce the bioexpression of phospho-P13D/Akt, and Bcl-2 level and increased cleaved caspase-9a level in both OGOMV prevention and treatment tMCAO groups (P > 0.05). Our study suggests that OGOMV could exert a neuroprotective effect by inhibiting the P13D/Akt protein, attenuating inflammation, and cleaved caspase-3- and -9a-related apoptosis. This study also lends credence to support the notion that the prevention of OGOMV could attenuate proinflammatory cytokine mRNA and late-onset caspases in tMCAO and merits further study. Copyright © 2016 Elsevier Inc. All rights reserved.

Magnetic resonance imaging detection of multiple ischemic injury produced in an adult rat model of minor stroke followed by mild transient cerebral ischemia.

PubMed

Tuor, Ursula I; Qiao, Min

2017-04-01

To determine whether cumulative brain damage produced adjacent to a minor stroke that is followed by a mild transient ischemia is detectable with MRI and histology, and whether acute or chronic recovery between insults influences this damage. A minor photothrombotic (PT) stroke was followed acutely (1-2 days) or chronically (7 days) by a mild transient middle cerebral artery occlusion (tMCAO). MRI was performed after each insult, followed by final histology. The initial PT produced small hyperintense T 2 and DW infarct lesions and peri-lesion regions of scattered necrosis and modestly increased T 2 . Following tMCAO, in a slice and a region adjacent to the PT, a region of T 2 augmentation was observed when recovery between insults was acute but not chronic. Within the PT slice, a modest region of exacerbated T 2 change proximate to the PT was also observed in the chronic group. Corresponding histological changes within regions of augmented T 2 included increased vacuolation and cell death. Within regions adjacent to an experimental minor stroke, a recurrence of a mild transient cerebral ischemia augmented T 2 above increases produced by tMCAO alone, reflecting increased damage in this region. Exacerbation appeared broader with acute versus chronic recovery between insults.

High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS) Improves Functional Recovery by Enhancing Neurogenesis and Activating BDNF/TrkB Signaling in Ischemic Rats

PubMed Central

Luo, Jing; Zheng, Haiqing; Zhang, Liying; Zhang, Qingjie; Li, Lili; Pei, Zhong; Hu, Xiquan

2017-01-01

Repetitive transcranial magnetic stimulation (rTMS) has rapidly become an attractive therapeutic approach for stroke. However, the mechanisms underlying this remain elusive. This study aimed to investigate whether high-frequency rTMS improves functional recovery mediated by enhanced neurogenesis and activation of brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway and to compare the effect of conventional 20 Hz rTMS and intermittent theta burst stimulation (iTBS) on ischemic rats. Rats after rTMS were sacrificed seven and 14 days after middle cerebral artery occlusion (MCAO), following evaluation of neurological function. Neurogenesis was measured using specific markers: Ki67, Nestin, doublecortin (DCX), NeuN and glial fibrillary acidic protein (GFAP), and the expression levels of BDNF were visualized by Western blotting and RT-PCR analysis. Both high-frequency rTMS methods significantly improved neurological function and reduced infarct volume. Moreover, 20 Hz rTMS and iTBS significantly promoted neurogenesis, shown by an increase of Ki67/DCX, Ki67/Nestin, and Ki67/NeuN-positive cells in the peri-infarct striatum. These beneficial effects were accompanied by elevated protein levels of BDNF and phosphorylated-TrkB. In conclusion, high-frequency rTMS improves functional recovery possibly by enhancing neurogenesis and activating BDNF/TrkB signaling pathway and conventional 20 Hz rTMS is better than iTBS at enhancing neurogenesis in ischemic rats. PMID:28230741

Carvacrol Exerts Neuroprotective Effects Via Suppression of the Inflammatory Response in Middle Cerebral Artery Occlusion Rats.

PubMed

Li, Zhenlan; Hua, Cong; Pan, Xiaoqiang; Fu, Xijia; Wu, Wei

2016-08-01

Increasing evidence demonstrates that inflammation plays an important role in cerebral ischemia. Carvacrol, a monoterpenic phenol, is naturally occurring in various plants belonging to the family Lamiaceae and exerts protective effects in a mice model of focal cerebral ischemia/reperfusion injury by reducing infarct volume and decreasing the expression of cleaved caspase-3. However, the anti-inflammatory mechanisms by which carvacrol protect the brain have yet to be fully elucidated. We investigated the effects of carvacrol on inflammatory reaction and inflammatory mediators in middle cerebral artery occlusion rats. The results of the present study showed that carvacrol inhibited the levels of inflammatory cytokines and myeloperoxidase (MPO) activity, as well as the expression of iNOS and COX-2. It also increased SOD activity and decreased MDA level in ischemic cortical tissues. In addition, carvacrol treatment suppressed the ischemia/reperfusion-induced increase in the protein expression of nuclear NF-kB p65. In conclusion, we have shown that carvacrol inhibits the inflammatory response via inhibition of the NF-kB signaling pathway in a rat model of focal cerebral ischemia. Therefore, carvacrol may be a potential therapeutic agent for the treatment of cerebral ischemia injury.

Effect of fibrin glue occlusion of the hepatobiliary tract on thioacetamide-induced liver failure.

PubMed

Schmandra, T C; Bauer, H; Petrowsky, H; Herrmann, G; Encke, A; Hanisch, E

2001-07-01

Expression and activation of hepatocyte growth factor (HGF) is stimulated by a complex system of interacting proteins, with thrombin playing an initial role in this process. The impact of temporary occlusion of the hepatobiliary tract with fibrin glue (major component thrombin) on the HGF system in acute and chronic liver damage in a rat model was investigated. Chronic liver damage was induced in 40 rats by daily intraperitoneal application of thioacetamide (100 mg/kg) for 14 days. After 7 days half of them received an injection of 0.2 mL fibrin glue into the hepatobiliary system. Daily intraperitoneal administration of thioacetamide continued for 7 consecutive days. The rats were then sacrificed for blood and tissue analysis. Acute liver failure was induced in 12 rats by intraperitoneal administration of a lethal dose of thioacetamide (500 mg/kg per day for 3 days) after an injection with 0.2 mL fibrin glue into their hepatobiliary tract. Survival rates and histological outcome were investigated and compared with control animals. Fibrin glue occluded rats showed significantly lower liver enzyme activities and serum levels of bilirubin, creatinine and urea nitrogen. Immunohistochemistry revealed a significant increase in c-met-, HGFalpha- and especially HGFbeta-positive cells. Rats subjected to a lethal dose of thioacetamide survived when fibrin glue was applied 24 hours prior to the toxic challenge. These animals showed normal liver structure and no clinical abnormalities. Fibrin glue occlusion of the hepatobiliary tract induces therapeutic and prophylactic effects on chronic and acute liver failure by stimulating the HGF system. Therefore, fibrin glue occlusion might be useful in treating toxic liver failure.

Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

PubMed

Guo, Ruo-Bing; Wang, Guo-Feng; Zhao, An-Peng; Gu, Jun; Sun, Xiu-Lan; Hu, Gang

2012-01-01

Paeoniflorin (PF), the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO)-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2) and 5-LOX) in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

Radial extracorporeal shock wave therapy improves cerebral blood flow and neurological function in a rat model of cerebral ischemia.

PubMed

Kang, Nan; Zhang, Jing; Yu, Xiaotong; Ma, Yuewen

2017-01-01

We performed middle cerebral artery occlusion (MCAO) in rats to investigate the effect and some of the underlying mechanisms of radial extracorporeal shock wave therapy (rESWT) in cerebral ischemia rats. We measured neurological function and cerebral blood flow (CBF) using a full-field laser perfusion imager and brain infarct volume on days 3, 12, and 30. Immunofluorescence, western blot, and real-time polymerase chain reaction (PCR) techniques were used to detect the expression of vascular endothelial growth factor (VEGF), neuron-specific enolase (NSE), nestin, Wnt3a, and β-catenin in the ischemic hemisphere. The dose of rESWT used on the head revealed remarkable advantages over sham rESWT, as demonstrated by improved neurological function scores, increased CBF, and reduced brain infarct volume. Furthermore, applying rESWT to the head and limbs enhanced short-term neurological function. Our results confirmed that rESWT can induce VEGF expression over an extended period with a profound effect, which may be the primary reason for CBF recovery. High NSE and nestin expression levels suggest that rESWT enhanced the number of neurons and neural stem cells (NSCs). Wnt3a and β-catenin expression were up-regulated in the ischemic hemisphere, indicating that rESWT promoted NSC proliferation and differentiation via the Wnt/β-catenin pathway. Overall, our findings suggest that an appropriate rESWT dose delivered to the head of rats helps restore neurological function and CBF, and additional application of rESWT to the limbs is more effective than treating the head alone.

Opposite effects of the gap junction blocker octanol on focal cerebral ischemia occluded for different durations.

PubMed

Ding, Wenting; Zhou, Lequan; Liu, Wei; Guan, Li; Li, Xiaoying; Liu, Haimei; Yan, Fuman; Xu, Jinwen; Zeng, Weiyong; Qiu, Min

2014-06-01

Protectants and executioners have been demonstrated to be used by gap junctions in focal cerebral ischemia. Certain researchers hypothesized that the opposite role of gap junctions may be associated with the injury extent, which has been demonstrated to be highly correlated with occlusion duration. In order to examine this hypothesis directly, the effects of octanol, a frequently used drug, were examined to investigate the role of gap junctions, in rats following middle cerebral artery occlusion (MCAO) for 30 min/2 h and 24 h reperfusion, respectively. Octanol significantly reduced the infarct volume following 2 h of occlusion concomitant with lower neurological deficits, whereas it enlarged the infarct volume following 30 min of occlusion. Consistently, octanol attenuated the number of transferase dUTP nick-end labeling (TUNEL) positive neurons in the hippocampal CA1 region following 2 h of occlusion, while opposite effects were observed for 30 min of occlusion. Further immunohistochemical studies demonstrated that the expression of B-cell leukemia-2 (Bcl-2, anti-apoptotic protein) was upregulated and that Bcl-2-associated X (Bax, proapoptotic protein) was downregulated following 2 h of occlusion in the octanol group compared with the ischemic group. Conversely, octanol downregulated the expression of the Bcl-2 protein concomitant with increased Bax protein following 30 min of occlusion. These results indicated that the gap junction blocker octanol can protect against ischemic injury following long-term occlusion, however, can aggravate ischemic injury following short-term occlusion.

[Relationship between Occlusal Discomfort Syndrome and Occlusal Threshold].

PubMed

Munakata, Motohiro; Ono, Yumie; Hayama, Rika; Kataoka, Kanako; Ikuta, Ryuhei; Tamaki, Katsushi

2016-03-01

Occlusal dysesthesia has been defined as persistent uncomfortable feelings of intercuspal position continuing for more than 6 months without evidence of physical occlusal discrepancy. The problem often occurs after occlusal intervention by dental care. Although various dental treatments (e. g. occlusal adjustment, orthodontic treatment and prosthetic reconstruction) are attempted to solve occlusal dysesthesia, they rarely reach a satisfactory result, neither for patients nor dentists. In Japan, these symptoms are defined by the term "Occlusal discomfort syndrome" (ODS). The aim of this study was to investigate the characteristics of ODS with the simple occlusal sensory perceptive and discriminative test. Twenty-one female dental patients with ODS (mean age 55.8 ± 19.2 years) and 21 age- and gender-matched dental patients without ODS (mean age 53.1 ± 16.8 years) participated in the study. Upon grinding occlusal registration foils that were stacked to different thicknesses, participants reported the thicknesses at which they recognized the foils (recognition threshold) and felt discomfort (discomfort threshold). Although there was no significant difference in occlusal recognition thresholds between the two patient groups, the discomfort threshold was significantly smaller in the patients with ODS than in those without ODS. Moreover, the recognition threshold showed an age-dependent increase in patients without ODS, whereas it remained comparable between the younger (< 60 years old) and elderly (60 years old or more) patient subgroups with ODS. These results suggest that occlusal discomfort threshold rather than recognition threshold is an issue in ODS. The foil grinding procedure is a simple and useful method to evaluate occlusal perceptive and discriminative abilities in patients with ODS.

[The effect of butylphthalide on expression of NGF and BDNF in ischemia stroke tissue of rat cerebrum].

PubMed

Kong, Shuang-yan; Li, Qi-fu; Yang, Jie; He, Li

2007-06-01

To study the expressions of BDNF, BDNF mRNA, NGF and NGF mRNA in the permanent focal cerebral ischemia tissues of rats. METHHODS: Healthy male Sprague-Dawley rats were taken for this study project. According to the procedure of Zea-Longa, the rat model with permanent cerebral ischemia was established by rat middle cerebral artery obstructed (MCAO) with a nylon thread, and the model rats of neurobehavioral evaluation as 1-3 grade were randomly divided into two groups: butylphthalide group (A group) and control group (B group). A group was given with 25 mg/kg butylphthalide, B group was given with edible oil, two times every day. 3 days after occlusion, all rats were sacrificed after evaluated the neurobehavioral scores, and the samples of cerebrum were obtained after in situ perfusion and fixation with 40 g/L paraformaldehyde. 5 rats in each group were taken to tetrazolium chloride (TTC) staining for macroscopic observation of cerebral infarction area, the rest samples were processed by immunohistochemistry to evaluate effects of butylphthalide on BDNF and NGF expression, hybridization in situ to evaluate effects of butylphthalide on BDNF mRNA and NGF mRNA expression. SPSS12. 0 for statistical analysis, it was P<0. 05 as having statistical significance. Comparing to control group (B group), butylphthalide group (A group) did not have significantly pathological difference, but the grade of behavior and infarction area were apparently reduced (P<0. 05). In butylphthalide group, there was a significant expression up-regulation to BDNF, NGF, BDNF mRNA and NGF mRNA in the peripheral around infarction and cornu ammonis or hippocampus area (P<0. 05). However in the infarction area, the expressions of BDNF, NGF, BDNF mRNA and NGF mRNA had no significantly statistical difference (P> 0. 05). Comparing to control group, butylphthalide can significantly up-regulate the expressions of BDNF and NGF in genetic transcription level, and protect from the ischemia injury.

A microarray study of gene and protein regulation in human and rat brain following middle cerebral artery occlusion

PubMed Central

Mitsios, Nick; Saka, Mohamad; Krupinski, Jerzy; Pennucci, Roberta; Sanfeliu, Coral; Wang, Qiuyu; Rubio, Francisco; Gaffney, John; Kumar, Pat; Kumar, Shant; Sullivan, Matthew; Slevin, Mark

2007-01-01

Background Altered gene expression is an important feature of ischemic cerebral injury and affects proteins of many functional classes. We have used microarrays to investigate the changes in gene expression at various times after middle cerebral artery occlusion in human and rat brain. Results Our results demonstrated a significant difference in the number of genes affected and the time-course of expression between the two cases. The total number of deregulated genes in the rat was 335 versus 126 in the human, while, of 393 overlapping genes between the two array sets, 184 were changed only in the rat and 36 in the human with a total of 41 genes deregulated in both cases. Interestingly, the mean fold changes were much higher in the human. The expression of novel genes, including p21-activated kinase 1 (PAK1), matrix metalloproteinase 11 (MMP11) and integrase interactor 1, was further analyzed by RT-PCR, Western blotting and immunohistochemistry. Strong neuronal staining was seen for PAK1 and MMP11. Conclusion Our findings confirmed previous studies reporting that gene expression screening can detect known and unknown transcriptional features of stroke and highlight the importance of research using human brain tissue in the search for novel therapeutic agents. PMID:17997827

GSK-3β inhibitor TWS119 attenuates rtPA-induced hemorrhagic transformation and activates the Wnt/β-catenin signaling pathway after acute ischemic stroke in rats.

PubMed

Wang, Wei; Li, Mingchang; Wang, Yuefei; Li, Qian; Deng, Gang; Wan, Jieru; Yang, Qingwu; Chen, Qianxue; Wang, Jian

2016-12-01

Hemorrhagic transformation (HT) is a devastating complication for patients with acute ischemic stroke who are treated with tissue plasminogen activator (tPA). It is associated with high morbidity and mortality, but no effective treatments are currently available to reduce HT risk. Therefore, methods to prevent HT are urgently needed. In this study, we used TWS119, an inhibitor of glycogen synthase kinase 3β (GSK-3β), to evaluate the role of the Wnt/β-catenin signaling pathway in recombinant tPA (rtPA)-induced HT. Sprague-Dawley rats were subjected to a middle cerebral artery occlusion (MCAO) model of ischemic stroke and then were administered rtPA, rtPA combined with TWS119, or vehicle at 4 h. The animals were sacrificed 24 h after infarct induction. Rats treated with rtPA showed evident HT, had more severe neurologic deficit, brain edema, and blood-brain barrier breakdown, and had larger infarction volume than did the vehicle group. Rats treated with TWS119 had significantly improved outcomes compared with those of rats treated with rtPA alone. In addition, Western blot analysis showed that TWS119 increased the protein expression of β-catenin, claudin-3, and ZO-1 while suppressing the expression of GSK-3β. These results suggest that TWS119 reduces rtPA-induced HT and attenuates blood-brain barrier disruption, possibly through activation of the Wnt/β-catenin signaling pathway. This study provides a potential therapeutic strategy to prevent tPA-induced HT after acute ischemic stroke.

Systematic and detailed analysis of behavioural tests in the rat middle cerebral artery occlusion model of stroke: Tests for long-term assessment

PubMed Central

Diaz, Claris; Farr, Tracy D; Harrison, David J; Fuller, Anna; Tokarczuk, Paweł F; Stewart, Andrew J; Paisey, Stephen J; Dunnett, Stephen B

2016-01-01

In order to test therapeutics, functional assessments are required. In pre-clinical stroke research, there is little consensus regarding the most appropriate behavioural tasks to assess deficits, especially when testing over extended times in milder models with short occlusion times and small lesion volumes. In this study, we comprehensively assessed 16 different behavioural tests, with the aim of identifying those that show robust, reliable and stable deficits for up to two months. These tasks are regularly used in stroke research, as well as being useful for examining striatal dysfunction in models of Huntington’s and Parkinson’s disease. Two cohorts of male Wistar rats underwent the intraluminal filament model of middle cerebral artery occlusion (30 min) and were imaged 24 h later. This resulted in primarily subcortical infarcts, with a small amount of cortical damage. Animals were tested, along with sham and naïve groups at 24 h, seven days, and one and two months. Following behavioural testing, brains were processed and striatal neuronal counts were performed alongside measurements of total brain and white matter atrophy. The staircase, adjusting steps, rotarod and apomorphine-induced rotations were the most reliable for assessing long-term deficits in the 30 min transient middle cerebral artery occlusion model of stroke. PMID:27317655

Methylene Blue Ameliorates Ischemia/Reperfusion-Induced Cerebral Edema: An MRI and Transmission Electron Microscope Study.

PubMed

Fang, Qing; Yan, Xu; Li, Shaowu; Sun, Yilin; Xu, Lixin; Shi, Zhongfang; Wu, Min; Lu, Yi; Dong, Liping; Liu, Ran; Yuan, Fang; Yang, Shao-Hua

2016-01-01

The neuroprotective effect of methylene blue (MB) has been identified against various brain disorders, including ischemic stroke. In the present study, we evaluated the effects of MB on postischemic brain edema using magnetic resonance imaging (MRI) and transmission electron microscopy (TEM). Adult male rats were subjected to transient focal cerebral ischemia induced by 1 h middle cerebral artery occlusion (MCAO), followed by reperfusion. MB was infused intravenously immediately after reperfusion (3 mg/kg) and again at 3 h post-occlusion (1.5 mg/kg). Normal saline was administered as vehicle control. Sequential MRIs, including apparent diffusion coefficient (ADC) and T2-weighted imaging (T2WI), were obtained at 0.5, 2.5, and 48 h after the onset of stroke. Separated groups of animals were sacrificed at 2.5 and 48 h after stroke for ultrastructural analysis by TEM. In addition, final lesion volumes were analyzed by triphenyltetrazolium chloride (TTC) staining at 48 h after stroke. Ischemic stroke induced ADC lesion volume at 0.5 h during MCAOs that were temporally recovered at 1.5 h after reperfusion. No significant difference in ADC-defined lesion was observed between vehicle and MB treatment groups. At 48 h after stroke, MB significantly reduced ADC lesion and T2WI lesion volume and attenuated cerebral swelling. Consistently, MB treatment significantly decreased TTC-defined lesion volume at 48 h after stroke. TEM revealed remarkable swollen astrocytes, astrocytic perivascular end-feet, and concurrent shrunken neurons in the penumbra at 2.5 and 48 h after MCAO. MB treatment attenuated astrocyte swelling, the perivascular astrocytic foot process, and endothelium and also alleviated neuron degeneration. This study demonstrated that MB could decrease postischemic brain edema and provided additional evidence that future clinical investigation of MB for the treatment of ischemic stroke is warrented.

Treatment of experimental stroke with IL-10-producing B-cells reduces infarct size and peripheral and CNS inflammation in wild-type B-cell-sufficient mice

PubMed Central

Bodhankar, Sheetal; Chen, Yingxin; Vandenbark, Arthur A.; Murphy, Stephanie J.; Offner, Halina

2014-01-01

Clinical stroke induces inflammatory processes leading to cerebral and splenic injury and profound peripheral immunosuppression. IL-10 expression is elevated during major CNS diseases and limits inflammation in the brain. Recent evidence demonstrated that absence of B-cells led to larger infarct volumes and CNS damage after middle cerebral artery occlusion (MCAO) that could be prevented by transfer of IL-10+ B-cells. The purpose of this study was to determine if the beneficial immunoregulatory effects on MCAO of the IL-10+ B-cell subpopulation also extends to B-cell-sufficient mice that would better represent stroke subjects. CNS inflammation and infarct volumes were evaluated in male C57BL/6J (WT) mice that received either RPMI or IL-10+ B-cells and underwent 60 min of middle cerebral artery occlusion (MCAO) followed by 96 hours of reperfusion. Transfer of IL-10+ B-cells markedly reduced infarct volume in WT recipient mice when given 24 hours prior to or 4 hours after MCAO. B-cell protected MCAO mice had increased regulatory subpopulations in the periphery, reduced numbers of activated, inflammatory T-cells, decreased infiltration of T-cells and a less inflammatory milieu in the ischemic hemispheres of the IL-10+ B-cell-treated group. Moreover, transfer of IL-10+ B-cells 24 hours before MCAO led to a significant preservation of regulatory immune subsets in the IL-10+ B-cell protected group presumably indicating their role in immunomodulatory mechanisms, post-stroke. Our studies are the first to demonstrate a major immunoregulatory role for IL-10+ regulatory B-cells in preventing and treating MCAO in WT mice and also implicating their potential role in attenuating complications due to post-stroke immunosuppression. PMID:24374817

Combined metabolic and transcriptional profiling identifies pentose phosphate pathway activation by HSP27 phosphorylation during cerebral ischemia.

PubMed

Imahori, Taichiro; Hosoda, Kohkichi; Nakai, Tomoaki; Yamamoto, Yusuke; Irino, Yasuhiro; Shinohara, Masakazu; Sato, Naoko; Sasayama, Takashi; Tanaka, Kazuhiro; Nagashima, Hiroaki; Kohta, Masaaki; Kohmura, Eiji

2017-05-04

The metabolic pathophysiology underlying ischemic stroke remains poorly understood. To gain insight into these mechanisms, we performed a comparative metabolic and transcriptional analysis of the effects of cerebral ischemia on the metabolism of the cerebral cortex using middle cerebral artery occlusion (MCAO) rat model. Metabolic profiling by gas-chromatography/mass-spectrometry analysis showed clear separation between the ischemia and control group. The decreases of fructose 6-phosphate and ribulose 5-phosphate suggested enhancement of the pentose phosphate pathway (PPP) during cerebral ischemia (120-min MCAO) without reperfusion. Transcriptional profiling by microarray hybridization indicated that the Toll-like receptor and mitogen-activated protein kinase (MAPK) signaling pathways were upregulated during cerebral ischemia without reperfusion. In relation to the PPP, upregulation of heat shock protein 27 (HSP27) was observed in the MAPK signaling pathway and was confirmed through real-time polymerase chain reaction. Immunoblotting showed a slight increase in HSP27 protein expression and a marked increase in HSP27 phosphorylation at serine 85 after 60-min and 120-min MCAO without reperfusion. Corresponding upregulation of glucose 6-phosphate dehydrogenase (G6PD) activity and an increase in the NADPH/NAD + ratio were also observed after 120-min MCAO. Furthermore, intracerebroventricular injection of ataxia telangiectasia mutated (ATM) kinase inhibitor (KU-55933) significantly reduced HSP27 phosphorylation and G6PD upregulation after MCAO, but that of protein kinase D inhibitor (CID755673) did not affect HSP27 phosphorylation. Consequently, G6PD activation via ischemia-induced HSP27 phosphorylation by ATM kinase may be part of an endogenous antioxidant defense neuroprotection mechanism during the earliest stages of ischemia. These findings have important therapeutic implications for the treatment of stroke. Copyright © 2017 IBRO. Published by Elsevier Ltd. All

Immunomodulatory effect of Hawthorn extract in an experimental stroke model.

PubMed

Elango, Chinnasamy; Devaraj, Sivasithambaram Niranjali

2010-12-30

Recently, we reported a neuroprotective effect for Hawthorn (Crataegus oxyacantha) ethanolic extract in middle cerebral artery occlusion-(MCAO) induced stroke in rats. The present study sheds more light on the extract's mechanism of neuroprotection, especially its immunomodulatory effect. After 15 days of treatment with Hawthorn extract [100 mg/kg, pretreatment (oral)], male Sprague Dawley rats underwent transient MCAO for 75 mins followed by reperfusion (either 3 or 24 hrs). We measured pro-inflammatory cytokines (IL-1β, TNF-α, IL-6), ICAM-1, IL-10 and pSTAT-3 expression in the brain by appropriate methods. We also looked at the cytotoxic T cell sub-population among leukocytes (FACS) and inflammatory cell activation and recruitment in brain (using a myeloperoxidase activity assay) after ischemia and reperfusion (I/R). Apoptosis (TUNEL), and Bcl-xL- and Foxp3- (T(reg) marker) positive cells in the ipsilateral hemisphere of the brain were analyzed separately using immunofluorescence. Our results indicate that occlusion followed by 3 hrs of reperfusion increased pro-inflammatory cytokine and ICAM-1 gene expressions in the ipsilateral hemisphere, and that Hawthorn pre-treatment significantly (p ≤ 0.01) lowered these levels. Furthermore, such pre-treatment was able to increase IL-10 levels and Foxp3-positive cells in brain after 24 hrs of reperfusion. The increase in cytotoxic T cell population in vehicle rats after 24 hrs of reperfusion was decreased by at least 40% with Hawthorn pretreatment. In addition, there was a decrease in inflammatory cell activation and infiltration in pretreated brain. Hawthorn pretreatment elevated pSTAT-3 levels in brain after I/R. We also observed an increase in Bcl-xL-positive cells, which in turn may have influenced the reduction in TUNEL-positive cells compared to vehicle-treated brain. In summary, Hawthorn extract helped alleviate pro-inflammatory immune responses associated with I/R-induced injury, boosted IL-10 levels, and

Immunomodulatory effect of Hawthorn extract in an experimental stroke model

PubMed Central

2010-01-01

Background Recently, we reported a neuroprotective effect for Hawthorn (Crataegus oxyacantha) ethanolic extract in middle cerebral artery occlusion-(MCAO) induced stroke in rats. The present study sheds more light on the extract's mechanism of neuroprotection, especially its immunomodulatory effect. Methods After 15 days of treatment with Hawthorn extract [100 mg/kg, pretreatment (oral)], male Sprague Dawley rats underwent transient MCAO for 75 mins followed by reperfusion (either 3 or 24 hrs). We measured pro-inflammatory cytokines (IL-1β, TNF-α, IL-6), ICAM-1, IL-10 and pSTAT-3 expression in the brain by appropriate methods. We also looked at the cytotoxic T cell sub-population among leukocytes (FACS) and inflammatory cell activation and recruitment in brain (using a myeloperoxidase activity assay) after ischemia and reperfusion (I/R). Apoptosis (TUNEL), and Bcl-xL- and Foxp3- (Treg marker) positive cells in the ipsilateral hemisphere of the brain were analyzed separately using immunofluorescence. Results Our results indicate that occlusion followed by 3 hrs of reperfusion increased pro-inflammatory cytokine and ICAM-1 gene expressions in the ipsilateral hemisphere, and that Hawthorn pre-treatment significantly (p ≤ 0.01) lowered these levels. Furthermore, such pre-treatment was able to increase IL-10 levels and Foxp3-positive cells in brain after 24 hrs of reperfusion. The increase in cytotoxic T cell population in vehicle rats after 24 hrs of reperfusion was decreased by at least 40% with Hawthorn pretreatment. In addition, there was a decrease in inflammatory cell activation and infiltration in pretreated brain. Hawthorn pretreatment elevated pSTAT-3 levels in brain after I/R. We also observed an increase in Bcl-xL-positive cells, which in turn may have influenced the reduction in TUNEL-positive cells compared to vehicle-treated brain. Conclusions In summary, Hawthorn extract helped alleviate pro-inflammatory immune responses associated with I

Electroacupuncture ameliorating post-stroke cognitive impairments via inhibition of peri-infarct astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia.

PubMed

Huang, Jia; You, Xiaofang; Liu, Weilin; Song, Changming; Lin, Xiaomin; Zhang, Xiufeng; Tao, Jing; Chen, Lidian

2017-10-10

During ischemic stroke (IS), adenosine 5'-triphosphate (ATP) is released from damaged nerve cells of the infract core region to the extracellular space, invoking peri-infarct glial cellular P2 purinoceptors singling, and causing pro-inflammatory cytokine secretion, which is likely to initiate or aggravate motor and cognitive impairment. It has been proved that electroacupuncture (EA) is an effective and safe strategy used in anti-inflammation. However, EA for the role of purine receptors in the central nervous system has not yet been reported. Ischemia-reperfusion injured rat model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). EA treatment at the DU 20 and DU 24 acupoints treatment were conducted to rats from the 12 h after MCAO/R injury for consecutive 7 days. The neurological outcomes, infarction volumes and the level of astroglial and microglial/macrophage hyperplasia, inflammatory cytokine and P2X7R and P2Y1R expression in the peri-infarct hippocampal CA1and sensorimotor cortex were investigated after IS to evaluate the MCAO/R model and therapeutic mechanism of EA treatment. EA effectively reduced the level of pro-inflammatory cytokine interleukin-1β (IL-1β) as evidenced by reduction in astroglial and microglial/macrophage hyperplasia and the levels of P2X7R and ED1, P2X7R and GFAP, P2Y1R and ED1, P2Y1R and GFAP co-expression in peri-infarct hippocampal CA1 and sensorimotor cortex compared with that of MCAO/R model and Non-EA treatment, accompanied by the improved neurological deficit and the motor and memory impairment outcomes. Therefore, our data support the hypothesis that EA could exert its anti-inflammatory effect via inhibiting the astroglial and microglial/macrophage P2 purinoceptors (P2X7R and P2Y1R)-mediated neuroinflammation after MCAO/R injury. Astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia in peri-infarct hippocampal CA1 and sensorimotor cortex were attenuated by EA

The Gemini-South MCAO operational model: insights on a new era of telescope operation

NASA Astrophysics Data System (ADS)

Trancho, Gelys; Bec, Matthieu; Artigau, Etienne; d'Orgeville, Celine; Gratadour, Damien; Rigaut, Francois J.; Walls, Brian

2008-07-01

The Gemini Observatory is implementing a Multi-Conjugate Adaptive Optics (MCAO) system as a facility instrument for the Gemini South telescope (GeMS). The system will include 5 Laser Guide Stars, 3 Natural Guide Stars, and 3 deformable mirrors, optically conjugated at different altitudes, to achieve near-uniform atmospheric compensation over a one arc minute square field of view. This setup implies some level of operational complexity. In this paper we describe how GeMS will be integrated into the flow of Gemini operations, from the observing procedures necessary to execute the programs in the queue (telescope control software, observing tools, sequence executor) to the safety implementation needed such as spotters/ASCAM, space command and laser traffic control software.

Human Dental Pulp Stem Cells Are More Effective Than Human Bone Marrow-Derived Mesenchymal Stem Cells in Cerebral Ischemic Injury.

PubMed

Song, Miyeoun; Lee, Jae-Hyung; Bae, Jinhyun; Bu, Youngmin; Kim, Eun-Cheol

2017-06-09

We compared the therapeutic effects and mechanism of transplanted human dental pulp stem cells (hDPSCs) and human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in a rat stroke model and an in vitro model of ischemia. Rats were intravenously injected with hDPSCs or hBM-MSCs 24 h after middle cerebral artery occlusion (MCAo), and both groups showed improved functional recovery and reduced infarct volume versus control rats, but the hDPSC group showed greater reduction in infarct volume than the hBM-MSC group. The positive area for the endothelial cell marker was greater in the lesion boundary areas in the hDPSC group than in the hBM-MSC group. Administration of hDPSCs to rats with stroke significantly decreased reactive gliosis, as evidenced by the attenuation of MCAo-induced GFAP+/nestin+ and GFAP+/Musashi-1+ cells, compared with hBM-MSCs. In vivo findings were confirmed by in vitro data illustrating that hDPSCs showed superior neuroprotective, migratory, and in vitro angiogenic effects in oxygen-glucose deprivation (OGD)-injured human astrocytes (hAs) versus hBM-MSCs. Comprehensive comparative bioinformatics analyses from hDPSC- and hBM-MSC-treated in vitro OGD-injured hAs were examined by RNA sequencing technology. In gene ontology and KEGG pathway analyses, significant pathways in the hDPSC-treated group were the MAPK and TGF-β signaling pathways. Thus, hDPSCs may be a better cell therapy source for ischemic stroke than hBM-MSCs.

Focal cerebral ischemic tolerance and change in blood-brain barrier permeability after repetitive pure oxygen exposure preconditioning in a rodent model.

PubMed

Wang, Xi; Kang, Kai; Wang, Shiquan; Yao, Jianhua; Zhang, Xijing

2016-10-01

OBJECTIVE The goal of this study was to demonstrate that repetitive pure oxygen exposure preconditioning (O 2 PC) for 8 hours per day for 3 or 7 days, a practicable preconditioning for clinical use, is able to induce cerebral ischemic tolerance (IT) and further clarify the accompanying changes in the blood-brain barrier (BBB) that may be involved. METHODS A total of 68 adult male Sprague-Dawley rats and eight 1-day-old rat pups were used in this study. The adult rats were exposed to pure O 2 (38 rats) 8 hours a day for 3 or 7 days or to room air (in an identical setup) for 8 hours a day for 7 days as controls (30 rats). Arterial O 2 tension (PaO 2 ) was measured in 6 rats exposed to O 2 and 3 controls. Focal cerebral ischemia was elicited by middle cerebral artery occlusion (MCAO) in 37 rats, of which 21 had been exposed to pure O 2 for 3 or 7 days and 16 to room air for 7 days as controls. Neurological behavior was scored with the Garcia score in 15 MCAO rats, of which 10 had been exposed to pure O 2 for 3 or 7 days and 5 to room air for 7 days as controls, and cerebral infarct volumes were assessed with TTC (2,3,5-triphenyltetrazolium chloride) staining in 10 rats (5 from each group) after 7 days of exposure. Formamide-extraction method was used to detect leakage of Evans blue (EB) dye in 7 rats exposed to pure O 2 for 7 days and 7 exposed to room air for 7 days. Fluorescence microscopy was used to analyze the leaked EB in the nonischemic areas of 4 rats exposed to pure O 2 for 7 days and 4 exposed to room air for 7 days before MCAO and the brain of the rats that had not been subjected to MCAO. Astrocyte changes associated with O 2 PC were evaluated by means of fluorescence microscopy and electron microscopy in 14 rats that were exposed to the same O 2 or control conditions as the MCAO rats but without MCAO. Astrocytes were also obtained from 8 rat pups and cultured; levels of AQP4 and VEGF were detected by Western blot and ELISA in cells with and without O 2

PD-L1 mAb Treats Ischemic Stroke by Controlling CNS Inflammation

PubMed Central

Bodhankar, Sheetal; Chen, Yingxin; Lapato, Andrew; Dotson, Abby L.; Wang, Jianming; Vandenbark, Arthur A.; Saugstad, Julie A.; Offner, Halina

2015-01-01

Background and Purpose Both pathogenic and regulatory immune processes are involved in the middle cerebral artery occlusion (MCAO) model of experimental stroke, including interactions involving the Programmed Death 1 (PD-1) receptor and its two ligands, PD-L1 and PD-L2. Although PD-1 reduced stroke severity, PD-L1 and PD-L2 appeared to play pathogenic roles, suggesting use of anti-PD-L monoclonal Ab (mAb) therapy for MCAO. Methods Male C57BL/6 mice were treated with a single dose of anti-PD-L1 mAb 4 h after MCAO and evaluated for clinical, histological and immunological changes after 96 h reperfusion. Results Blockade of the PD-L1 checkpoint using a single injection of 200μg anti-PD-L1 mAb given i.v. 4 h after occlusion significantly reduced MCAO infarct volumes and improved neurological outcomes after 96 h reperfusion. Treatment partially reversed splenic atrophy and decreased CNS infiltrating immune cells concomitant with enhanced appearance of CD8+ regulatory T cells in the lesioned CNS hemisphere. Conclusions This study demonstrates for the first time the beneficial therapeutic effects of PD-L1 checkpoint blockade on MCAO, thus validating proposed mechanisms obtained in our previous studies using PD-1 and PD-L deficient mice. These results provide strong support for use of available humanized anti-PD-L1 antibodies for treatment of human stroke subjects. PMID:26306753

Corticotropin-releasing factor: effect on cerebral blood flow in physiologic and ischaemic conditions.

PubMed

De Michele, Manuela; Touzani, Omar; Foster, Alan C; Fieschi, Cesare; Sette, Giuliano; McCulloch, James

2005-09-01

The expression of corticotrophin-releasing factor (CRF) receptors in cerebral arteries and arterioles suggests that CRF may modulate cerebral blood flow (CBF). In the present study, the effects of CRF, CRF-like peptides and the CRF broad spectrum antagonist DPhe-CRF on CBF have been investigated under normal physiologic conditions and in the margins of focal ischaemic insult. The experiments were carried out in anaesthetised and ventilated rats. Changes in CBF after subarachnoid microapplication of CRF and related peptides were assessed with a laser-Doppler flowmetry (LDF) probe. In the ischaemic animals, agents were injected approximately 60 minutes after permanent middle cerebral artery occlusion (MCAo). Microapplication of CRF and related peptides in normal rats into the subarachnoid space produced sustained concentration-dependent increases in CBF. This effect was attenuated by co-application with DPhe-CRF, which did not alter CBF itself. A second microapplication of CRF 30 min after the first failed to produce increases in CBF in normal animals. Microapplication of CRF in the subarachnoid space overlying the ischaemic cortex effected minor increases in CBF whereas D-Phe-CRF had no significant effect on CBF. Activation of the CRF peptidergic system increases CBF in the rat. Repeated activation of CRF receptors results in tachyphylaxis of the vasodilator response. CRF vasodilator response is still present after MCAo in the ischaemic penumbra, suggesting that the CRF peptidergic system may modulate CBF in ischaemic stroke.

Hawthorn extract reduces infarct volume and improves neurological score by reducing oxidative stress in rat brain following middle cerebral artery occlusion.

PubMed

Elango, Chinnasamy; Jayachandaran, Kasevan Sawaminathan; Niranjali Devaraj, S

2009-12-01

In our present investigation the neuroprotective effect of alcoholic extract of Hawthorn (Crataegus oxycantha) was evaluated against middle cerebral artery occlusion induced ischemia/reperfusion injury in rats. Male Sprague-Dawley rats were pretreated with 100 mg/kg body weight of the extract by oral gavage for 15 days. The middle cerebral artery was then occluded for 75 min followed by 24 h of reperfusion. The pretreated rats showed significantly improved neurological behavior with reduced brain infarct when compared to vehicle control rats. The glutathione level in brain was found to be significantly (p<0.05) low in vehicle control rats after 24 h of reperfusion when compared to sham operated animals. However, in Hawthorn extract pretreated rats the levels were found to be close to that of sham. Malondialdehyde levels in brain of sham and pretreated group were found to be significantly lower than the non-treated vehicle group (p<0.05). The nitric oxide levels in brain were measured and found to be significantly (p<0.05) higher in vehicle than in sham or extract treated rats. Our results suggest that Hawthorn extract which is a well known prophylactic for cardiac conditions may very well protect the brain against ischemia-reperfusion. The reduced brain damage and improved neurological behavior after 24 h of reperfusion in Hawthorn extract pretreated group may be attributed to its antioxidant property which restores glutathione levels, circumvents the increase in lipid peroxidation and nitric oxide levels thereby reducing peroxynitrite formation and free radical induced brain damage.

Long-Term Post-Stroke Changes Include Myelin Loss, Specific Deficits in Sensory and Motor Behaviors and Complex Cognitive Impairment Detected Using Active Place Avoidance

PubMed Central

Li, Jie; Ooi, Evelyn; Bloom, Jonathan; Poon, Carrie; Lax, Daniel; Rosenbaum, Daniel M.; Barone, Frank C.

2013-01-01

Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be

[Effect of Electroacupuncture on Expression of Apelin-APJ System of Cerebral Vascular Endothelial Cell in Rats with Cerebral Infarction].

PubMed

Yang, Li-Hong; Du, Yuan-Hao; Li, Jing

2017-02-25

To observe the regulation of APJ and its ligand Apelin on the angiogenesis pathway after cerebral infarction and the intervention effect of acupuncture. Wistar rats were randomly divided into model group( n =90), electroacupuncture(EA) group( n =90), sham operation group( n =90) and control group( n =10). The first three groups were further divided into 1,3,6,9,12,24 h and 3,7, 12 d subgroups( n =10 in each subgroup). The cerebral infarction model was established by middle cerebral artery occlusion (MCAO). EA(15 Hz, 2 mA) was applied to "Shuigou" (GV 26) for 20 min in the EA group. The 1, 3, 6, 9, 12, 24 h subgroups were treated immediately after modeling, the 3, 7, 9 d subgroups were treated once daily for 3, 7 or 9 days. Real-time fluorescent quantitative (RT-PCR) and Western blot were applied to detect the changes of Apelin and APJ in cerebrovascular endothelial cells, respectively. Compared with the control group, the expression of Apelin-APJ mRNA was decreased in the model group(12 h, 12 d, P <0.05, P <0.01); After EA, the Apelin mRNA expression was increased in the 12 h and 7 d subgroups ( P <0.01), while the APJ mRNA expression was increased in the 6, 9, 12 h subgroups( P <0.05, P <0.01). Compared with the control group, the Apelin(1, 3, 6, 24 h and 3, 7, 12 d) and APJ(1, 3, 6, 9 h and 3 d) protein expressions were decreased in the model group( P <0.01, P <0.05); After EA, the Apelin protein expression was increased in the 6, 24 h and 3, 7, 12 d subgroups ( P <0.05, P <0.01), while the APJ protein expression was increased in the 1, 9, 12, 24 h and 3, 7, 12 d subgroups ( P <0.05, P <0.01). EA can up-regulate the expression of Apelin-APJ mRNA and protein of cerebral vascular endothelial cell in MCAO rats which has an important role in the establishment of blood vessel regeneration and collateral circulation.

An Antioxidant Phytotherapy to Rescue Neuronal Oxidative Stress

PubMed Central

Lin, Zhihong; Zhu, Danni; Yan, Yongqing; Yu, Boyang; Wang, Qiujuan; Shen, Pingniang; Ruan, Kefeng

2011-01-01

Oxidative stress is involved in the pathogenesis of ischemic neuronal injury. A Chinese herbal formula composed of Poria cocos (Chinese name: Fu Ling), Atractylodes macrocephala (Chinese name: Bai Zhu) and Angelica sinensis (Chinese names: Danggui, Dong quai, Donggui; Korean name: Danggwi) (FBD), has been proved to be beneficial in the treatment of cerebral ischemia/reperfusion (I/R).This study was carried out to evaluate the protective effect of FBD against neuronal oxidative stress in vivo and in vitro. Rat I/R were established by middle cerebral artery occlusion (MCAO) for 1 h, followed by 24 h reperfusion. MCAO led to significant depletion in superoxide dismutase and glutathione and rise in lipid peroxidation (LPO) and nitric oxide in brain. The neurological deficit and brain infarction were also significantly elevated by MCAO as compared with sham-operated group. All the brain oxidative stress and damage were significantly attenuated by 7 days pretreatment with the aqueous extract of FBD (250 mg kg−1, p.o.). Moreover, cerebrospinal fluid sampled from FBD-pretreated rats protected PC12 cells against oxidative insult induced by 0.2 mM hydrogen peroxide, in a concentration and time-dependent manner (IC50 10.6%, ET50 1.2 h). However, aqueous extract of FBD just slightly scavenged superoxide anion radical generated in xanthine–xanthine oxidase system (IC50 2.4 mg ml−1) and hydroxyl radical generated in Fenton reaction system (IC50 3.6 mg ml−1). In conclusion, FBD was a distinct antioxidant phytotherapy to rescue neuronal oxidative stress, through blocking LPO, restoring endogenous antioxidant system, but not scavenging free radicals. PMID:18955358

Neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides on cerebral ischemic injury in rats.

PubMed

Zhou, Zi-Yi; Tang, Yu-Ping; Xiang, Jun; Wua, Pin; Jin, Hui-Ming; Wang, Zhong; Mori, Masao; Cai, Ding-Fang

2010-08-19

To investigate the neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides (GLPS) on cerebral ischemic injury in rats, and to explore the involved mechanisms. Two models [middle cerebral artery occlusion (MCAO) in Sprague-Dawley (SD) rats and oxygen and glucose deprivation (OGD) in primary cultured rat cortical neurons] were employed to mimic ischemia-reperfusion (I/R) damage, in vivo and in vitro, respectively. Cerebral infarct area was measured by tetrazolium staining, and neurological functional deficits were assessed at 24h after I/R. Neuronal apoptosis was studied by Nissl staining and DNA fragmentation assay. Neuronal injury was assessed by morphological examination using phase-contrast microscopy and quantified by measuring the amount of lactate dehydrogenase (LDH) leakage, cell viability was measured by sodium 3'-1- (phenylaminocarbonyl)-3, 4-tetrazolium-bis (4-methoxy-6-nitro) benzene sulfonic acid (XTT) reduction. Neuronal apoptosis was determined by flow cytometry, and electron microscopy was used to study morphological changes of neurons. Caspase-3, -8 and -9 activation and Bcl-2, Bax protein expression were determined by western blot analysis. Oral administration of GLPS (100, 200 and 400mg/kg) significantly reduced cerebral infarct area, attenuated neurological functional deficits, and reduced neuronal apoptosis in ischemic cortex. In OGD model, GLSP (0.1, 1 and 10 microg/ml) effectively reduced neuronal cell death and relieved cell injury. Moreover, GLPS decreased the percentage of apoptotic neurons, relieved neuronal morphological damage, suppressed overexpression of active caspases-3, -8 and -9 and Bax, and inhibited the reduction of Bcl-2 expression. Our findings indicate that GLPS protects against cerebral ischemic injury by inhibiting apoptosis by downregulating caspase-3 activation and modulating the Bcl-2/Bax ratio. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Intermittent fasting attenuates increases in neurogenesis after ischemia and reperfusion and improves recovery.

PubMed

Manzanero, Silvia; Erion, Joanna R; Santro, Tomislav; Steyn, Frederik J; Chen, Chen; Arumugam, Thiruma V; Stranahan, Alexis M

2014-05-01

Intermittent fasting (IF) is neuroprotective across a range of insults, but the question of whether extending the interval between meals alters neurogenesis after ischemia remains unexplored. We therefore measured cell proliferation, cell death, and neurogenesis after transient middle cerebral artery occlusion (MCAO) or sham surgery (SHAM) in mice fed ad libitum (AL) or maintained on IF for 3 months. IF was associated with twofold reductions in circulating levels of the adipocyte cytokine leptin in intact mice, but also prevented further reductions in leptin after MCAO. IF/MCAO mice also exhibit infarct volumes that were less than half those of AL/MCAO mice. We observed a 30% increase in basal cell proliferation in the hippocampus and subventricular zone (SVZ) in IF/SHAM, relative to AL/SHAM mice. However, cell proliferation after MCAO was limited in IF mice, which showed twofold increases in cell proliferation relative to IF/SHAM, whereas AL/MCAO mice exhibit fivefold increases relative to AL/SHAM. Attenuation of stroke-induced neurogenesis was correlated with reductions in cell death, with AL/MCAO mice exhibiting twice the number of dying cells relative to IF/MCAO mice. These observations indicate that IF protects against neurological damage in ischemic stroke, with circulating leptin as one possible mediator.

Intermittent fasting attenuates increases in neurogenesis after ischemia and reperfusion and improves recovery

PubMed Central

Manzanero, Silvia; Erion, Joanna R; Santro, Tomislav; Steyn, Frederik J; Chen, Chen; Arumugam, Thiruma V; Stranahan, Alexis M

2014-01-01

Intermittent fasting (IF) is neuroprotective across a range of insults, but the question of whether extending the interval between meals alters neurogenesis after ischemia remains unexplored. We therefore measured cell proliferation, cell death, and neurogenesis after transient middle cerebral artery occlusion (MCAO) or sham surgery (SHAM) in mice fed ad libitum (AL) or maintained on IF for 3 months. IF was associated with twofold reductions in circulating levels of the adipocyte cytokine leptin in intact mice, but also prevented further reductions in leptin after MCAO. IF/MCAO mice also exhibit infarct volumes that were less than half those of AL/MCAO mice. We observed a 30% increase in basal cell proliferation in the hippocampus and subventricular zone (SVZ) in IF/SHAM, relative to AL/SHAM mice. However, cell proliferation after MCAO was limited in IF mice, which showed twofold increases in cell proliferation relative to IF/SHAM, whereas AL/MCAO mice exhibit fivefold increases relative to AL/SHAM. Attenuation of stroke-induced neurogenesis was correlated with reductions in cell death, with AL/MCAO mice exhibiting twice the number of dying cells relative to IF/MCAO mice. These observations indicate that IF protects against neurological damage in ischemic stroke, with circulating leptin as one possible mediator. PMID:24549184

Infarct Volume Prediction by Early Magnetic Resonance Imaging in a Murine Stroke Model Depends on Ischemia Duration and Time of Imaging.

PubMed

Leithner, Christoph; Füchtemeier, Martina; Jorks, Devi; Mueller, Susanne; Dirnagl, Ulrich; Royl, Georg

2015-11-01

Despite standardization of experimental stroke models, final infarct sizes after middle cerebral artery occlusion (MCAO) vary considerably. This introduces uncertainties in the evaluation of drug effects on stroke. Magnetic resonance imaging may detect variability of surgically induced ischemia before treatment and thus improve treatment effect evaluation. MCAO of 45 and 90 minutes induced brain infarcts in 83 mice. During, and 3 and 6 hours after MCAO, we performed multiparametric magnetic resonance imaging. We evaluated time courses of cerebral blood flow, apparent diffusion coefficient (ADC), T1, T2, accuracy of infarct prediction strategies, and impact on statistical evaluation of experimental stroke studies. ADC decreased during MCAO but recovered completely on reperfusion after 45 and partially after 90-minute MCAO, followed by a secondary decline. ADC lesion volumes during MCAO or at 6 hours after MCAO largely determined final infarct volumes for 90 but not for 45 minutes MCAO. The majority of chance findings of final infarct volume differences in random group allocations of animals were associated with significant differences in early ADC lesion volumes for 90, but not for 45-minute MCAO. The prediction accuracy of early magnetic resonance imaging for infarct volumes depends on timing of magnetic resonance imaging and MCAO duration. Variability of the posterior communicating artery in C57Bl6 mice contributes to differences in prediction accuracy between short and long MCAO. Early ADC imaging may be used to reduce errors in the interpretation of post MCAO treatment effects on stroke volumes. © 2015 American Heart Association, Inc.

Potential therapeutic and protective effect of curcumin against stroke in the male albino stroke-induced model rats.

PubMed

Zhang, Yuanyuan; Yan, Yi; Cao, Yi; Yang, Yongtao; Zhao, Qing; Jing, Rui; Hu, Jiayi; Bao, Juan

2017-08-15

The present study was carried out to understand the therapeutic effect of curcumin (CUR) against stroke in the experimental animal model. The study investigates the healing effect of CUR on mitochondrial dysfunction and inflammation. Male albino, Wistar strain rats were used for the induction of middle cerebral artery occlusion (MCAO), and reperfusion. Enzyme-linked immunosorbent assay (ELISA) was used for the determination of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in the brain region. Western blot analysis was used to determine the protein expression levels of Bax, Bcl-2, p53, and Sirt1. The water level was determined in brain region by using standard method. Experimental results indicated that the use of CUR significantly reduced brain edema and water content. IL-6 and TNF-α were significantly reduced in the brain region following use of CUR. Mitochondrial membrane potential (MMP) also reduced significantly after CUR treatment. Protein expression of p53 and Bax were significantly reduced, whereas Bcl-2 and Sirt1 were increased following CUR treatment. Taking all these data together, it is suggested that the use of CUR may be a potential therapeutic agent for the treatment of stroke. Copyright © 2017 Elsevier Inc. All rights reserved.

TGF-β1/Smad3 Signaling Pathway Suppresses Cell Apoptosis in Cerebral Ischemic Stroke Rats

PubMed Central

Zhu, Haiping; Gui, Qunfeng; Hui, Xiaobo; Wang, Xiaodong; Jiang, Jian; Ding, Lianshu; Sun, Xiaoyang; Wang, Yanping; Chen, Huaqun

2017-01-01

Background We desired to observe the changes of transforming growth factor-β1/drosophila mothers against decapentaplegic protein (TGF-β1/Smad3) signaling pathway in the hippocampus region of cerebral ischemic stroke rats so that the effects of this pathway on nerve cells can be investigated. Material/Methods The ischemic stroke models were built by middle cerebral artery occlusion (MCAO) in vivo and oxygen-glucose deprivation (OGD) in vitro. TGF-β1 and TGF-β1 inhibitors were injected into rat models while TGF-β1, TGF-β1 siRNA, Smad3, and Smad3 siRNA were transfected into cells. Infarct sizes were measured using triphenyltetrazolium chloride (TTC) staining, while the apoptosis rate of cells were calculated by Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining. Levels of TGF-β1, Smad3, and Bcl-2 were examined by real-time polymerase chain reaction (RT-PCR), immunohistochemical, and Western blot analysis. Results The expressions of TGF-β1/Smad3 signal pathway were significantly increased in both model rats and BV2 cells, whereas the expression of Bcl-2 was down-regulated (P<0.05). The TGF-β1/Smad3 signal pathway exhibited protective effects, including the down-regulation of infarction size in cerebral tissues and the down-regulation of apoptosis rate of BV2 cells by increasing the expression of Bcl-2 (P<0.05). In addition, these effects could be antagonized by the corresponding inhibitors and siRNA (P<0.05). Conclusions The TGF-β1/Smad3 signaling pathway was up-regulated once cerebral ischemic stroke was simulated. TGF-β1 may activate the expression of Bcl-2 via Smad3 to suppress the apoptosis of neurons. PMID:28110342

AAV-mediated targeting of gene expression to the peri-infarct region in rat cortical stroke model.

PubMed

Mätlik, Kert; Abo-Ramadan, Usama; Harvey, Brandon K; Arumäe, Urmas; Airavaara, Mikko

2014-10-30

For stroke patients the recovery of cognitive and behavioral functions is often incomplete. Functional recovery is thought to be mediated largely by connectivity rearrangements in the peri-infarct region. A method for manipulating gene expression in this region would be useful for identifying new recovery-enhancing treatments. We have characterized a way of targeting adeno-associated virus (AAV) vectors to the peri-infarct region of cortical ischemic lesion in rats 2days after middle cerebral artery occlusion (MCAo). We used magnetic resonance imaging (MRI) to show that the altered properties of post-ischemic brain tissue facilitate the spreading of intrastriatally injected nanoparticles toward the infarct. We show that subcortical injection of green fluorescent protein-encoding dsAAV7-GFP resulted in transduction of cells in and around the white matter tract underlying the lesion, and in the cortex proximal to the lesion. A similar result was achieved with dsAAV7 vector encoding the cerebral dopamine neurotrophic factor (CDNF), a protein with therapeutic potential. Viral vector-mediated intracerebral gene delivery has been used before in rodent models of ischemic injury. However, the method of targeting gene expression to the peri-infarct region, after the initial phase of ischemic cell death, has not been described before. We demonstrate a straightforward and robust way to target AAV vector-mediated over-expression of genes to the peri-infarct region in a rat stroke model. This method will be useful for studying the action of specific proteins in peri-infarct region during the recovery process. Copyright © 2014 Elsevier B.V. All rights reserved.

Increased brain injury and vascular leakage after pretreatment with p38-inhibitor SB203580 in transient ischemia.

PubMed

Lennmyr, F; Ericsson, A; Gerwins, P; Ahlström, H; Terént, A

2003-11-01

Focal cerebral ischemia activates intracellular signaling pathways including the mitogen-activated protein kinase p38, which may be involved in the process of ischemic brain injury. In this study, the effect of pretreatment with the p38-inhibitor SB203580 on infarct size and blood-brain barrier (BBB) breakdown was investigated with magnetic resonance imaging (MRI). Rats were given SB203580 (n = 6) or vehicle (n = 6) in the right lateral ventricle prior to transient (90 min) middle cerebral artery occlusion (MCAO) on the left side. The rats were examined with serial MRI during MCAO, at reperfusion and after 1 and 4 days. The mean infarct size on T2-weighted images after 1 day was significantly higher in the SB203580-treated group than in controls (300 +/- 95 mm3 vs 126 +/- 75 mm3; P < 0.01). Vascular gadolinium leakage, indicating BBB breakdown, was significantly larger in the SB203580-treated group than in controls after 1 day (median leakage score 18.5; range 15-21 vs 6.5; 4-17; P < 0.05) and 4 days (11; 6-15 vs 3.5; 1-9; P < 0.05), although no significant difference was seen initially. Pretreatment with SB203580 may aggravate ischemic brain injury and cerebral vascular leakage in the present model of transient ischemia.

Delayed administration of parecoxib, a specific COX-2 inhibitor, attenuated postischemic neuronal apoptosis by phosphorylation Akt and GSK-3β.

PubMed

Ye, Zhi; Wang, Na; Xia, Pingping; Wang, E; Yuan, Yajing; Guo, Qulian

2012-02-01

Parecoxib is a recently described novel COX-2 inhibitor whose functional significance and neuroprotective mechanisms remain elusive. Therefore, in this study, we aimed to investigate whether delayed administration of parecoxib inhibited mitochondria-mediated neuronal apoptosis induced by ischemic reperfusion injury via phosphorylating Akt and its downstream target protein, glycogen synthase kinase 3β (GSK-3β). Adult male Sprague-Dawley rats were administered parecoxib (10 or 30 mg kg(-1), IP) or isotonic saline twice a day starting 24 h after middle cerebral artery occlusion (MCAO) for three consecutive days. Cerebral infarct volume, apoptotic neuron, caspase-3 immunoreactivity and the protein expression of p-Akt, p-GSK-3β and Cytochrome C in cerebral ischemic cortex were evaluated at 96 h after reperfusion. Parecoxib significantly diminished infarct volume and attenuated neuron apoptosis in a dose-independent manner, compared with MCAO group alone. Increased p-Akt and p-GSK-3β was observed in the ischemic penumbra of parecoxib group after stroke. Moreover, parecoxib also reduced the release of Cytochrome C from mitochondrial into cytosol and attenuated the caspase-3 immunoreactivity in the penumbra. Taken together, these results suggested that parecoxib ameliorated postischemic mitochondria-mediated neuronal apoptosis induced by focal cerebral ischemia in rats and this neuroprotective potential is involved in phosphorylation of Akt and GSK-3β.

Formononetin mediates neuroprotection against cerebral ischemia/reperfusion in rats via downregulation of the Bax/Bcl-2 ratio and upregulation PI3K/Akt signaling pathway.

PubMed

Liang, Kun; Ye, Yu; Wang, Yong; Zhang, Jianfeng; Li, Chaoqian

2014-09-15

Isoflavone formononetin is a typical phytoestrogen isolated from Chinese medical herb red clover. It has been reported that estrogens have neuroprotective properties, and dietary intake of phytoestrogens could reduce stroke injury in cerebral ischemia/reperfusion (I/R) animal models. In the present research, we sought to investigate the molecular mechanisms underlying the neuroprotective effects of formononetin on I/R rats. Male Sprague-Dawley rats were subjected to a 2 h period of right middle cerebral artery occlusion (MCAO) followed by 24 h of reperfusion. Then neurological deficits and brain edema were evaluated. To provide insight into the functions of phosphatidylinositol 3-kinase (PI3K)/Akt and MAPK (mitogen-activated protein kinase) signaling pathway in formononetin-induced neuroprotection, the expression of ER-α, Bax, Bcl-2, p-Akt (phosphorylated protein kinase B), and p-ERK1/2 (phosphorylated extracellular signal-regulated kinases 1/2) was determined by qPCR or Western blot assay. Consequently, we found that formononetin has significantly reduced the infarcted volume and the brain water content, and improved the neurological deficit. Formononetin also exhibited an upregulation in ER-α and p-Akt, a downregulation in the ratio of Bax/Bcl-2. However, formononetin had little effect on p-ERK1/2 proteins expression. Taken together, formononetin has shown neuroprotective effects in cerebral I/R rats, and the molecular mechanisms may correlate with the downregulation of the Bax/Bcl-2 ratio and the activation of PI3K/Akt signaling pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of electroacupuncture on the cortical extracellular signal regulated kinase pathway in rats with cerebral ischaemia/reperfusion.

PubMed

Wu, Chunxiao; Li, Chun; Zhou, Guoping; Yang, Lu; Jiang, Guimei; Chen, Jing; Li, Qiushi; Zhan, Zhulian; Xu, Xiuhong; Zhang, Xin

2017-12-01

To explore the effects of electroacupuncture (EA) on the phosphorylated extracellular signal regulated kinase (p-ERK) pathway of the cerebral cortex in a rat model of focal cerebral ischaemia/reperfusion (I/R). 160 adult Sprague-Dawley rats underwent middle carotid artery occlusion (MCAO) to establish I/R injury and were randomly divided into four groups (n=40 each) that remained untreated (I/R group) or received EA at LU5, LI4, ST36 and SP6 (I/R+EA group), the ERK inhibitor PD98059 (I/R+PD group), or both interventions (I/R+PD+EA groups). An additional 40 rats undergoing sham surgery formed a healthy control group. Eight rats from each group were sacrificed at the following time points: 2 hours, 6 hours, 1 day, 3 days and 1 week. Neurological function was assessed using neurological deficit scores, morphological examination was performed following haematoxylin-eosin staining of cortical tissues, and apoptotic indices were calculated after terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labelling. Cortical protein and mRNA expression of p-ERK and ERK were measured by immunohistochemistry and real-time quantitative PCR, respectively. Compared with the I/R group, neurological deficit scores and apoptotic indices were lower in the I/R+EA group at 1 and 3 days, whereas mRNA/protein expression of ERK/p-ERK was higher in the EA group at all time points studied. Our results suggest that EA can alleviate neurological deficits and reduce cortical apoptosis in rats with I/R injury. These anti-apoptotic effects may be due to upregulation of p-ERK. Moreover, apoptosis appeared to peak at 1 day after I/R injury, which might therefore represent the optimal time point for targeting of EA. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Different mechanisms of secondary neuronal damage in thalamic nuclei after focal cerebral ischemia in rats.

PubMed

Dihné, Marcel; Grommes, Christian; Lutzenburg, Michael; Witte, Otto W; Block, Frank

2002-12-01

After focal cerebral ischemia, depending on its localization and extent, secondary neuronal damage may occur that is remote from the initial lesion. In this study differences in secondary damage of the ventroposterior thalamic nucleus (VPN) and the reticular thalamic nucleus (RTN) were investigated with the use of different ischemia models. Transient middle cerebral artery occlusion (MCAO) leads to cortical infarction, including parts of the basal ganglia such as the globus pallidus, and to widespread edema. Photothrombotic ischemia generates pure cortical infarcts sparing the basal ganglia and with only minor edema. Neuronal degeneration was quantified within the ipsilateral RTN and VPN 14 days after ischemia. Glial reactions were studied with the use of immunohistochemistry. MCAO resulted in delayed neuronal cell loss of the ipsilateral VPN and RTN. Glial activation occurred in both nuclei beginning after 24 hours. Photothrombotic ischemia resulted in delayed neuronal cell loss only within the VPN. Even 2 weeks after photothrombotic ischemia, glial activation could only be seen within the VPN. Pure cortical infarcts after photothrombotic ischemia, without major edema and without effects on the globus pallidus of the basal ganglia, only lead to secondary VPN damage that is possibly due to retrograde degeneration. MCAO, which results in infarction of cortex and globus pallidus and which causes widespread edema, leads to secondary damage in the VPN and RTN. Thus, additional RTN damage may be due to loss of protective GABAergic input from the globus pallidus to the RTN or due to the extensive edema. Retrograde degeneration is not possible because the RTN, in contrast to the VPN, has no efferents to the cortex.

Protective effects of beef decoction rich in carnosine on cerebral ischemia injury by permanent middle cerebral artery occlusion in rats

PubMed Central

Wang, Ai-Hong; Ma, Qian; Wang, Xin; Xu, Gui-Hua

2018-01-01

Inflammation has a role in the cerebral injury induced by ischemia and the present study aimed to determine the mechanism of the protective effect of beef decoction (BD) with carnosine against it. A rat model of permanent middle cerebral artery occlusion was established using a suture method in the vehicle and each of the BD groups. In experiment 1, 72 Sprague Dawley (SD) rats were randomly divided into three groups: Sham, vehicle and BD-treated group. Rats in the BD group were given 600 mg/kg BD by oral gavage for 1, 3 and 7 days. The sham and vehicle group rats received an equivalent amount of normal saline. In experiment 2, 60 SD rats were randomly divided into six groups: Sham-operated I, sham-operated II, vehicle, low-dose BD, medium-dose BD and high-dose BD group. Rats in the low-, medium- and high-dose BD groups were given BD at the dose of 200, 400 and 600 mg/kg, respectively, by oral gavage for 7 days. Rats in the sham-operated II group were given 600 mg/kg BD. Rats in the sham-operated I group and vehicle group were given the same volume of normal saline by oral gavage. The body weight, neurological deficits and infarct volume were recorded at 1, 3 and 7 days after the operation. Furthermore, the effect of different doses of BD on interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin-4 (IL-4) levels in peripheral blood was measured at 7 days. BD-treated rats showed less neurological deficits and a smaller infarct volume at 7 days. BD at 400 and 600 mg/kg significantly decreased the infarct volume in rats. At 600 mg/kg BD, a decline in IL-6, TNF-α, IFN-γ and an increase in IL-4 expression was observed in the BD groups, while no difference in body weight and neurological dysfunction was detected. In conclusion, BD is a neuroprotective agent that may be used as a supplement treatment of ischemic stroke. PMID:29399121

Protective effects of beef decoction rich in carnosine on cerebral ischemia injury by permanent middle cerebral artery occlusion in rats.

PubMed

Wang, Ai-Hong; Ma, Qian; Wang, Xin; Xu, Gui-Hua

2018-02-01

Inflammation has a role in the cerebral injury induced by ischemia and the present study aimed to determine the mechanism of the protective effect of beef decoction (BD) with carnosine against it. A rat model of permanent middle cerebral artery occlusion was established using a suture method in the vehicle and each of the BD groups. In experiment 1, 72 Sprague Dawley (SD) rats were randomly divided into three groups: Sham, vehicle and BD-treated group. Rats in the BD group were given 600 mg/kg BD by oral gavage for 1, 3 and 7 days. The sham and vehicle group rats received an equivalent amount of normal saline. In experiment 2, 60 SD rats were randomly divided into six groups: Sham-operated I, sham-operated II, vehicle, low-dose BD, medium-dose BD and high-dose BD group. Rats in the low-, medium- and high-dose BD groups were given BD at the dose of 200, 400 and 600 mg/kg, respectively, by oral gavage for 7 days. Rats in the sham-operated II group were given 600 mg/kg BD. Rats in the sham-operated I group and vehicle group were given the same volume of normal saline by oral gavage. The body weight, neurological deficits and infarct volume were recorded at 1, 3 and 7 days after the operation. Furthermore, the effect of different doses of BD on interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin-4 (IL-4) levels in peripheral blood was measured at 7 days. BD-treated rats showed less neurological deficits and a smaller infarct volume at 7 days. BD at 400 and 600 mg/kg significantly decreased the infarct volume in rats. At 600 mg/kg BD, a decline in IL-6, TNF-α, IFN-γ and an increase in IL-4 expression was observed in the BD groups, while no difference in body weight and neurological dysfunction was detected. In conclusion, BD is a neuroprotective agent that may be used as a supplement treatment of ischemic stroke.

Time-course of neurodegeneration and memory impairment following the 4-vessel occlusion/internal carotid artery model of chronic cerebral hypoperfusion in middle-aged rats.

PubMed

Pereira, Francine Martins; Ferreira, Emilene Dias Fiuza; de Oliveira, Rúbia Maria Weffort; Milani, Humberto

2012-04-15

The present work extends previous studies with the aim of developing the 4-vessel occlusion/internal carotid artery (4-VO/ICA) model of chronic cerebral hypoperfusion. The permanent occlusion of the vertebral arteries (VAs) and internal carotid arteries (ICAs) followed the sequence VA→ICA→ICA. The interstage interval (ISI, →), chronicity of 4-VO/ICA, and age of the animals may determine the success of the model with regard to neurohistological and behavioral outcomes. Using middle-aged rats, the present study evaluated (i) how brain damage evolves as the ISI is reduced and duration (i.e., "chronicity") of 4-VO/ICA is prolonged and (ii) how the duration of 4-VO/ICA affects retrograde memory performance. Male Wistar rats (12-15 months of age) were subjected to 4-VO/ICA with an ISI of 7, 5, 4, or 3 days, and hippocampal and cortical damage was examined 7, 30, and 90 days later. Using an ISI of 4 days, retrograde memory performance was assessed in the aversive radial maze after 4-VO/ICA with a duration of 7, 30, and 90 days. The severity of brain neurodegeneration and rate of mortality progressively increased as the ISI length decreased from 7 to 3 days, an effect that was not significantly altered by the chronicity of 4-VO/ICA. Permanent 4-VO/ICA effectively caused retrograde amnesia, an effect that worsened as the chronicity of 4-VO/ICA was prolonged. The findings confirm and expand the notion that permanent, 3-stage 4-VO/ICA effectively produces extensive neurodegeneration and persistent learning/memory impairment in middle-aged rats and that the ISI length, more than the chronicity of 4-VO/ICA, determines the final results. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of the Sigma-1 Receptor Agonist 1-(3,4-Dimethoxyphenethyl)-4-(3-Phenylpropyl)-Piperazine Dihydro-Chloride on Inflammation after Stroke

PubMed Central

Ruscher, Karsten; Inácio, Ana R.; Kuric, Enida; Wieloch, Tadeusz

2012-01-01

Activation of the sigma-1 receptor (Sig-1R) improves functional recovery in models of experimental stroke and is known to modulate microglia function. The present study was conducted to investigate if Sig-1R activation after experimental stroke affects mediators of the inflammatory response in the ischemic hemisphere. Male Wistar rats were subjected to transient occlusion of the middle cerebral artery (MCAO) and injected with the specific Sig-1R agonist 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) or saline for 5 days starting on day 2 after MCAO. Treatment did not affect the increased levels of the pro-inflammatory cytokines interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin 4 (IL-4), interleukin 5 (IL-5), and interleukin 13 (IL-13) in the infarct core and peri-infarct area after MCAO. In addition, treatment with SA4503 did not affect elevated levels of nitrite, TNF-α and IL-1β observed in primary cultures of microglia exposed to combined Hypoxia/Aglycemia, while the unspecific sigma receptor ligand 1,3-di-o-tolylguanidine (DTG) significantly decreased the production of nitrite and levels of TNF-α. Analysis of the ischemic hemisphere also revealed increased levels of ionized calcium binding adaptor molecule 1 (Iba1) levels in the infarct core of SA4503 treated animals. However, no difference in Iba1 immunoreactivity was detected in the infarct core. Also, levels of the proliferation marker proliferating cell nuclear antigen (PCNA) and OX-42 were not increased in the infarct core in rats treated with SA4503. Together, our results suggest that sigma-1 receptor activation affects Iba1 expression in microglia/macrophages of the ischemic hemisphere after experimental stroke but does not affect post-stroke inflammatory mediators. PMID:23028794

Diet-Induced Ketosis Protects Against Focal Cerebral Ischemia in Mouse.

PubMed

Xu, Kui; Ye, Lena; Sharma, Katyayini; Jin, Yongming; Harrison, Matthew M; Caldwell, Tylor; Berthiaume, Jessica M; Luo, Yu; LaManna, Joseph C; Puchowicz, Michelle A

2017-01-01

Over the past decade we have consistently shown that ketosis is neuroprotective against ischemic insults in rats. We reported that diet-induced ketotic rats had a significant reduction in infarct volume when subjected to middle cerebral artery occlusion (MCAO), and improved survival and recovery after cardiac arrest and resuscitation. The neuroprotective mechanisms of ketosis (via ketogenic diet; KG) include (i) ketones are alternate energy substrates that can restore energy balance when glucose metabolism is deficient and (ii) ketones modulate cell-signalling pathways that are cytoprotective. We investigated the effects of diet-induced ketosis following transient focal cerebral ischemia in mice. The correlation between levels of ketosis and hypoxic inducible factor-1alpha (HIF-1α), AKT (also known as protein kinase B or PKB) and 5' AMP-activated protein kinase (AMPK) were determined. Mice were fed with KG diet or standard lab-chow (STD) diet for 4 weeks. For the MCAO group, mice underwent 60 min of MCAO and total brain infarct volumes were evaluated 48 h after reperfusion. In a separate group of mice, brain tissue metabolites, levels of HIF-1α, phosphorylated AKT (pAKT), and AMPK were measured. After feeding a KG diet, levels of blood ketone bodies (beta-hydroxyburyrate, BHB) were increased. There was a proportional decrease in infarct volumes with increased blood BHB levels (KG vs STD; 4.2 ± 0.6 vs 7.8 ± 2.2 mm 3 , mean ± SEM). A positive correlation was also observed with HIF-1α and pAKT relative to blood BHB levels. Our results showed that chronic ketosis can be induced in mice by KG diet and was neuroprotective against focal cerebral ischemia in a concentration dependent manner. Potential mechanisms include upregulation of cytoprotective pathways such as those associated with HIF-1α, pAKT and AMPK.

Dabigatran Etexilate Reduces Thrombin-Induced Inflammation and Thrombus Formation in Experimental Ischemic Stroke.

PubMed

Dittmeier, Melanie; Wassmuth, Kathrin; Schuhmann, Michael K; Kraft, Peter; Kleinschnitz, Christoph; Fluri, Felix

2016-01-01

Dabigatran etexilate (DE), a direct-acting, oral inhibitor of thrombin, significantly reduces the risk of stroke compared with traditional anticoagulants, without increasing the risk of major bleeding. However, studies on the fate of cerebral tissue after ischemic stroke in patients receiving DE are sparse and the role of dabigatran-mediated reduction of thrombin in this context has not yet been investigated. Here, we investigated whether pretreatment with DE reduces thrombin-mediated pro-inflammatory mechanisms and leakage of the blood-brain barrier (BBB) following ischemic stroke in rats. Male Wistar rats received DE (15 mg/kg) or a vehicle solution 1 hour before transient middle cerebral artery occlusion (tMCAO) for 90 minutes. Infarct volume, neurologic outcome and intracranial hemorrhage (ICH) were determined after tMCAO. Thrombin generation was indirectly assessed by measuring thrombin/antithrombin III complex. Microvascular patency was evaluated histologically. Cytokine expression and immunoreactivity of cluster of differentiation (CD) 68 were examined to characterize inflammatory processes after pretreatment with DE. BBB integrity was examined by quantifying brain edema. Rats given DE revealed a significant reduction in infarct size without an increase in ICH and significant recovery of neurologic deficits compared to controls. Administration of DE decreased thrombin generation and thrombus formation, dampened the CD68-immunoreactivity and attenuated pro-inflammatory cytokine expression in the cerebral parenchyma ipsilateral to the ischemic lesion. BBB permeability was unaltered following treatment with DE. In summary, prophylactic anticoagulation with DE improves stroke outcome by reducing thrombin-induced inflammation and thrombus formation without increasing the rate of ICH.

The effect of in vitro tracheal occlusion on branching morphogenesis in fetal lung explants from the rat nitrofen model of congenital diaphragmatic hernia.

PubMed

Grushka, Jeremy R; Al-Abbad, Saleh; Baird, Robert; Puligandla, Pramod; Kaplan, Feige; Laberge, Jean-Martin

2010-05-01

Fetal tracheal occlusion (TO) has been investigated as a treatment option for lung hypoplasia secondary to congenital diaphragmatic hernia. Tracheal occlusion has been shown to accelerate lung growth, but its effect on bronchial branching is unknown. In this study, we characterize the effects of in vitro TO on bronchial branch development in fetal lung explants derived from the nitrofen rat model of congenital diaphragmatic hernia. Rat dams were gavaged nitrofen on gestational day 9.5, and fetal lungs were harvested for explant culture on gestational day 14 (term, 22 days). Four experimental groups were investigated, with TO performed ex vivo using cautery: control, control + TO, nitrofen, and nitrofen + TO. Explants were incubated for 72 hours. Representative photographs were taken at 0, 24, 48, and 72 hours from the time of culture, and the number of distal branches was counted for each explant. The Student t test was used to compare distal branch measurements. A minimum of 12 fetal lung explants were cultured for each group. By 24 hours, all explants undergoing TO had more branch iterations than explants that did not. Moreover, TO in nitrofen-exposed explants increased bronchial branching to control levels by 24 hours in culture. Our results suggest that TO at day 14 increases branching in normal and nitrofen-exposed lung explants. In addition, TO increases airway branching in nitrofen-exposed explants to control levels suggesting that early TO reverses the lung hypoplasia seen in this model. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Effect of enriched environment on angiogenesis and neurological functions in rats with focal cerebral ischemia.

PubMed

Zhang, Xin; Chen, Xiu-Ping; Lin, Jun-Bin; Xiong, Yu; Liao, Wei-Jing; Wan, Qi

2017-01-15

The purpose of this study was to investigate the effect of enriched environment (EE) on cerebral angiogenesis after ischemia-reperfusion injury. Middle cerebral artery occlusion (MCAO) followed by reperfusion was performed in rats to set up an animal model of ischemia-reperfusion injury. In a set of behavioral tests, we demonstrated that the animals in the IEE (ischemia + enriched environment) group exhibited significantly improved neurological functions compared to those in the standard housing condition group. In consistent with the functional tests, smaller infarction volumes were observed in the animals of IEE group. Laser scanning confocal microscopy and 3D quantitative analysis of cerebral microvessels revealed that EE treatment increased the total vessel surface area and number of branch point in the ischemic boundary zone. IgG extraction assay showed that the blood brain barrier (BBB) leakage in the ischemic brain was attenuated after EE treatment. EE treatment also enhanced endothelial cells (ECs) proliferation and increased the expression levels of VEGF and its receptor Flk-1 after ischemia-reperfusion injury. Analyses of Spearman's correlation coefficients indicated a correlation of mNSS scores with enhanced cerebral angiogenesis. Together, the results suggest that EE treatment-induced cerebral angiogenesis may contribute to the improved neurological outcome of stroke animals after ischemia-reperfusion injury. Copyright © 2016 Elsevier B.V. All rights reserved.

Salvianolic acid B attenuates apoptosis and inflammation via SIRT1 activation in experimental stroke rats.

PubMed

Lv, Hongdi; Wang, Ling; Shen, Jinchang; Hao, Shaojun; Ming, Aimin; Wang, Xidong; Su, Feng; Zhang, Zhengchen

2015-06-01

Silent information regulator 1 (SIRT1), a histone deacetylase, has been suggested to be effective in ischemic brain diseases. Salvianolic acid B (SalB) is a polyphenolic and one of the active components of Salvia miltiorrhiza Bunge. Previous studies suggested that SalB is protective against ischemic stroke. However, the role of SIRT1 in the protective effect of SalB against cerebral ischemia has not been explored. In this study, the rat brain was subjected to middle cerebral artery occlusion (MCAO). Before this surgery, rats were intraperitoneally administrated SalB with or without EX527, a specific SIRT1 inhibitor. The infarct volume, neurological score and brain water content were assessed. In addition, levels of TNF-α and IL-1β in the brain tissues were detected by commercial ELISA kits. And the expression levels of SIRT, Ac-FOXO1, Bcl-2 and Bax were detected by Western blot. The results suggested that SalB exerted a cerebral-protective effect, as shown by reduced infarct volume, lowered brain edema and increased neurological scores. SalB also exerted anti-inflammatory effects as indicated by the decreased TNF-α and IL-1β levels in the brain tissue. Moreover, SalB upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of Ac-FOXO1 and Bax. These effects of SalB were abolished by EX527 treatment. In summary, our results demonstrate that SalB treatment attenuates brain injury induced by ischemic stoke via reducing apoptosis and inflammation through the activation of SIRT1 signaling. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulatory CD8+CD122+ T-cells predominate in CNS after treatment of experimental stroke in male mice with IL-10-secreting B-cells

PubMed Central

Lapato, Andrew; Vandenbark, Arthur A.; Murphy, Stephanie J.; Saugstad, Julie A.; Offner, Halina

2014-01-01

Clinical stroke induces inflammatory processes leading to cerebral and splenic injury and profound peripheral immunosuppression. IL-10 expression is elevated during major CNS diseases and limits inflammation in the brain. Recent evidence demonstrated that transfer of IL-10+ B-cells reduced infarct volume in male C57BL/6J (wild-type, WT) recipient mice when given 24 h prior to or 4 h after middle cerebral artery occlusion (MCAO). The purpose of this study was to determine if passively transferred IL-10+ B-cells can exert therapeutic and immunoregulatory effects when injected 24 hours after MCAO induction in B-cell-sufficient male WT mice. The results demonstrated that IL-10+ B-cell treated mice had significantly reduced infarct volumes in the ipsilateral cortex and hemisphere and improved neurological deficits vs. Vehicle-treated control mice after 60 min occlusion and 96 h of reperfusion. The MCAO-protected B-cell recipient mice had less splenic atrophy and reduced numbers of activated, inflammatory T-cells, decreased infiltration of T-cells and a less inflammatory milieu in the ischemic hemispheres compared with Vehicle-treated control mice. These immunoregulatory changes occurred in concert with the predominant appearance of IL-10-secreting CD8+CD122+ Treg cells in both the spleen and the MCAO-affected brain hemisphere. This study for the first time demonstrates a major neuroprotective role for IL-10+ B-cells in treating MCAO in male WT mice at a time point well beyond the ~4 h tPA treatment window, leading to the generation of a dominant IL-10+CD8+CD122+ Treg population associated with spleen preservation and reduced CNS inflammation. PMID:25537181

[Relationship between the changes in ischemia/reperfusion cerebro-microvessel basement membrane injury and gelatinase system in senile rat].

PubMed

Li, Jian-sheng; Liu, Ke; Liu, Jing-xia; Wang, Ming-hang; Zhao, Yue-wu; Liu, Zheng-guo

2008-11-01

To study the relationship of cerebro-microvessel basement membrane injury and gelatinase system after cerebral ischemia/reperfusion (I/R) in aged rats. Cerebral I/R injury model was reproduced by intraluminal silk ligature thrombosis of the middle cerebral artery occlusion (MCAO). Rats were divided randomly into sham control and I/R groups in young rats [ischemia 3 hours (I 3 h) and reperfusion 6 hours (I/R 6 h), 12 hours (I/R 12 h), 24 hours (I/R 24 h), 3 days (I/R 3 d), 6 days (I/R 6 d)], and sham control group and I/R group in aged rats (I 3 h and I/R 6 h, I/R 12 h, I/R 24 h , I/R 3 d, I/R 6 d). The change in cerebro-cortex microvessel basement membrane structure, basement membrane type IV collagen (Col IV) and laminin (LN) contents, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) expression in every group were determined with immunohistochemical method and zymogram analysis. With the increase in age, Col IV and LN contents of the microvessel basement membrane were increased, and MMP-2 and MMP-9 expressions were stronger. With prolongation of I/R, the degradation of microvessel basement membrane components (Col IV and LN) was positively correlated with the duration of cerebral I/R. MMP-2 expression was increased gradually, and MMP-9 and TIMP-1 expression increased at the beginning and decreased subsequently. Col IV(I 3 h, I/R 6 h , I/R 12 h), LN (I 3 h, I/R 6-24 h), MMP-2 (I 3 h, I/R 6 h-6 d) and MMP-9 (I 3 h, I/R 6-24 h) expression level in aged rats with I/R injury were higher, and TIMP-1 (I/R 24 h) expression was lower than those in young rats (P<0.05 or P<0.01). In addition, changes in MMP-2 and MMP-9 contents as determined by zymogram analysis method coincided with their immunoexpression. With the increase of age, alteration in membrane components of cerebro-microvessel basement membrane in rats is related with MMPs and TIMP. Cerebro-microvessel basement membrane injury is more serious in aged rats than that of young rats

Immune cell infiltration in malignant middle cerebral artery infarction: comparison with transient cerebral ischemia

PubMed Central

Chu, Hannah X; Kim, Hyun Ah; Lee, Seyoung; Moore, Jeffrey P; Chan, Christopher T; Vinh, Antony; Gelderblom, Mathias; Arumugam, Thiruma V; Broughton, Brad RS; Drummond, Grant R; Sobey, Christopher G

2014-01-01

We tested whether significant leukocyte infiltration occurs in a mouse model of permanent cerebral ischemia. C57BL6/J male mice underwent either permanent (3 or 24 hours) or transient (1 or 2 hours+22- to 23-hour reperfusion) middle cerebral artery occlusion (MCAO). Using flow cytometry, we observed ∼15,000 leukocytes (CD45+high cells) in the ischemic hemisphere as early as 3 hours after permanent MCAO (pMCAO), comprising ∼40% lymphoid cells and ∼60% myeloid cells. Neutrophils were the predominant cell type entering the brain, and were increased to ∼5,000 as early as 3 hours after pMCAO. Several cell types (monocytes, macrophages, B lymphocytes, CD8+ T lymphocytes, and natural killer cells) were also increased at 3 hours to levels sustained for 24 hours, whereas others (CD4+ T cells, natural killer T cells, and dendritic cells) were unchanged at 3 hours, but were increased by 24 hours after pMCAO. Immunohistochemical analysis revealed that leukocytes typically had entered and widely dispersed throughout the parenchyma of the infarct within 3 hours. Moreover, compared with pMCAO, there were ∼50% fewer infiltrating leukocytes at 24 hours after transient MCAO (tMCAO), independent of infarct size. Microglial cell numbers were bilaterally increased in both models. These findings indicate that a profound infiltration of inflammatory cells occurs in the brain early after focal ischemia, especially without reperfusion. PMID:24326388

A novel indication of platonin, a therapeutic immunomodulating medicine, on neuroprotection against ischemic stroke in mice

PubMed Central

Sheu, Joen-Rong; Chen, Zhih-Cherng; Jayakumar, Thanasekaran; Chou, Duen-Suey; Yen, Ting-Lin; Lee, Hsing-Ni; Pan, Szu-Han; Hsia, Chih-Hsuan; Yang, Chih-Hao; Hsieh, Cheng-Ying

2017-01-01

Thrombosis and stroke are major causes of disability and death worldwide. However, the regular antithrombotic drugs may have unsatisfactory results and side effects. Platonin, a cyanine photosensitizing dye, has been used to treat trauma, ulcers and some acute inflammation. Here, we explored the neuroprotective effects of platonin against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in mice. Platonin(200 μg/kg) substantially reduced cerebral infarct volume, brain edema, neuronal cell death and neurological deficit scores, and improved the MCAO-reduced locomotor activity and rotarod performance. Platonin(5–10 μM) potently inhibited platelet aggregation and c-Jun NH2-terminal kinase (JNK) phosphorylation in collagen-activated platelets. The antiaggregation effect did not affect bleeding time but increased occlusion time in platonin(100 and 200 μg/kg)-treated mice. Platonin(2–10 μM) was potent in diminishing collagen- and Fenton reaction-induced ∙OH formation. Platonin(5–10 μM) also suppressed the expression of nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-1β, and JNK phosphorylation in lipopolysaccharide-stimulated macrophages. MCAO-induced expression of 3-nitrotyrosine and Iba1 was apparently attenuated in platonin(200 μg/kg)-treated mice. In conclusion, platonin exhibited remarkable neuroprotective properties against MCAO-induced ischemia in a mouse model through its antiaggregation, antiinflammatory and antiradical properties. The observed therapeutic efficacy of platonin may consider being a novel medcine against ischemic stroke. PMID:28165057

Memantine attenuates cell apoptosis by suppressing the calpain-caspase-3 pathway in an experimental model of ischemic stroke.

PubMed

Chen, Bin; Wang, Guoxiang; Li, Weiwei; Liu, Weilin; Lin, Ruhui; Tao, Jing; Jiang, Min; Chen, Lidian; Wang, Yun

2017-02-15

Ischemic stroke, the second leading cause of death worldwide, leads to excessive glutamate release, over-activation of N-methyl-D-aspartate receptor (NMDAR), and massive influx of calcium (Ca 2+ ), which may activate calpain and caspase-3, resulting in cellular damage and death. Memantine is an uncompetitive NMDAR antagonist with low-affinity/fast off-rate. We investigated the potential mechanisms through which memantine protects against ischemic stroke in vitro and in vivo. Middle cerebral artery occlusion-reperfusion (MCAO) was performed to establish an experimental model of ischemic stroke. The neuroprotective effects of memantine on ischemic rats were evaluated by neurological deficit scores and infarct volumes. The activities of calpain and caspase-3, and expression levels of microtubule-associated protein-2 (MAP2) and postsynaptic density-95 (PSD95) were determined by Western blotting. Additionally, Nissl staining and immunostaining were performed to examine brain damage, cell apoptosis, and neuronal loss induced by ischemia. Our results show that memantine could significantly prevent ischemic stroke-induced neurological deficits and brain infarct, and reduce ATP depletion-induced neuronal death. Moreover, memantine markedly suppressed the activation of the calpain-caspase-3 pathway and cell apoptosis, and consequently, attenuated brain damage and neuronal loss in MCAO rats. These results provide a molecular basis for the role of memantine in reducing neuronal apoptosis and preventing neuronal damage, suggesting that memantine may be a promising therapy for stroke patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Paeoniflorin, a Monoterpene Glycoside, Protects the Brain from Cerebral Ischemic Injury via Inhibition of Apoptosis.

PubMed

Zhang, Yuqin; Li, Huang; Huang, Mingqing; Huang, Mei; Chu, Kedan; Xu, Wei; Zhang, Shengnan; Que, Jinhua; Chen, Lidian

2015-01-01

Paeoniflorin (PF) is a principal bioactive component, which exhibits many pharmacological effects, including protection against ischemic injury. This paper aimed to investigate the protective effect of PF both in vivo and in vitro. Middle cerebral artery occlusion (MCAO) was performed on male Sprague-Dawley (SD) rat for 2 h, and different doses of PF or vehicle were administered 2 h after reperfusion. Rats were sacrificed after 7 days treatment of PF/vehicle. PF treatment for 7 days ameliorated MCAO-induced neurological deficit and decreased the infarct area. Further study demonstrated that PF inhibited the over-activation of astrocytes and apoptosis of neurons, and PF promoted up-regulation of neuronal specific marker neuron-specific nuclear (NeuN) and microtubule-associated protein 2 (MAP-2) in brain. Moreover, NMDA-induced neuron apoptosis was employed. The in vitro study revealed that PF treatment protected against NMDA-induced cell apoptosis and neuronal loss via up-regulation of neuronal specific marker NeuN, MAP-2 and Bcl-2 and the down-regulation Bax. Taken together, the present study demonstrates that PF produces its protective effect by inhibiting the over-activation of astrocytes, apoptosis of neurons and up-regulation of neuronal specific marker NeuN, MAP-2, and B-cell lymphoma-2 (Bcl-2), and down-regulation Bax. Our study reveals that PF may be a potential neuroprotective agent for stroke and can provide basic data for clinical use.

Experimental occlusal disharmony - A promoting factor for anxiety in rats under chronic psychological stress.

PubMed

Tang, Xuan; Li, Jian; Jiang, Ting; Han, Shu-Hui; Yao, Dong-Yuan

2017-04-03

Clinically, patients under chronic psychological stress (PS) appear to be more susceptible to occlusal disharmony (OD) compared with those without PS. OD was proved to introduce anxiety-like stress. Therefore, the purpose of the study was to investigate whether OD would affect psychological stress-induced anxiety and its underlying mechanisms. Chronic PS was induced by a communication box, and OD was produced by bonding a 0.3mm-thick crown on the right maxillary first molar of male Sprague-Dawley rats. Sixty-seven rats were randomly divided into 8 groups: (A) chronic PS plus OD group (n=6); (B) chronic PS plus sham OD group (n=6); (C) chronic PS only group (n=6); (D) OD group (n=6); (E) sham OD group (n=6); (F) control group (n=6); (G) naive group (n=6); (H) foot-shock group (n=25). Open-field test (OFT) and elevated plus maze test (EPM) were conducted on the 7th, 21th, 35th day to measure the anxiety level of each group except naive and foot-shock group. In addition, corticosterone (CORT) level in serum, 5-hydroxytryptamine (5-HT) and 5-HT 2A receptor (5-HT 2A R) expressions in prefrontal cortex (PFC), hippocampal CA1 and dentate gyrus (DG) areas were measured on the 35th day to elucidate the mechanism(s) by which the exacerbation occurred. The significant differences in OFT and EPM tests on day 21 or day 35 between groups (p<0.01) indicated the successful establishment of animal model of PS or OD. And there was a significant increase in CORT concentration in serum (p<0.01), 5-HT expressions in PFC, hippocampal DG areas and 5-HT 2A R expressions in PFC, hippocampal CA1 areas (p<0.05) in group A, B, C, D compared with group F. Similar results were also found in group A, B, C, D when compared with group G (p<0.05) except 5-HT expression in DG area in group C and D (p>0.05), together with a gradual decrease in values of all the parameters mentioned above from group A to group G. The significant changes in exploratory behaviors, serum CORT concentration, 5-HT and 5-HT

Exercise preconditioning improves behavioral functions following transient cerebral ischemia induced by 4-vessel occlusion (4-VO) in rats.

PubMed

Tahamtan, Mahshid; Allahtavakoli, Mohammad; Abbasnejad, Mehdi; Roohbakhsh, Ali; Taghipour, Zahra; Taghavi, Mohsen; Khodadadi, Hassan; Shamsizadeh, Ali

2013-12-01

There is evidence that exercise decreases ischemia/reperfusion injury in rats. Since behavioral deficits are the main outcome in patients after stroke, our study was designed to investigate whether exercise preconditioning improves the acute behavioral functions and also brain inflammatory injury following cerebral ischemia. Male rats weighing 250-300 g were randomly allocated into five experimental groups. Exercise was performed on a treadmill 30min/day for 3 weeks. Ischemia was induced by 4-vessel occlusion method. Recognition memory was assessed by novel object recognition task (NORT) and step-through passive avoidance task. Sensorimotor function and motor movements were evaluated by adhesive removal test and ledged beam-walking test, respectively. Brain inflammatory injury was evaluated by histological assessment. In NORT, the discrimination ratio was decreased after ischemia (P < 0.05) and exercise preconditioning improved it in ischemic animals. In the passive avoidance test, a significant reduction in response latency was observed in the ischemic group. Exercise preconditioning significantly decreased the response latency in the ischemic rats (P < 0.001). In the adhesive removal test, latency to touch and remove the sticky labels from forepaw was increased following induction of ischemia (all P < 0.001) and exercise preconditioning decreased these indices compared to the ischemic group (all P < 0.001). In the ledged beam-walking test, the slip ratio was increased following ischemia (P < 0.05).  In the ischemia group, marked neuronal injury in hippocampus was observed. These neuropathological changes were attenuated by exercise preconditioning (P < 0.001). Our results showed that exercise preconditioning improves behavioral functions and maintains more viable cells in the dorsal hippocampus of the ischemic brain.

The effect of melatonin on bacterial translocation following ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion.

PubMed

Ozban, Murat; Aydin, Cagatay; Cevahir, Nural; Yenisey, Cigdem; Birsen, Onur; Gumrukcu, Gulistan; Aydin, Berrin; Berber, Ibrahim

2015-03-08

Acute mesenteric ischemia is a life-threatening vascular emergency resulting in tissue destruction due to ischemia-reperfusion injury. Melatonin, the primary hormone of the pineal gland, is a powerful scavenger of reactive oxygen species (ROS), including the hydroxyl and peroxyl radicals, as well as singlet oxygen, and nitric oxide. In this study, we aimed to investigate whether melatonin prevents harmful effects of superior mesenteric ischemia-reperfusion on intestinal tissues in rats. Rats were randomly divided into three groups, each having 10 animals. In group I, the superior mesenteric artery (SMA) was isolated but not occluded. In group II and group III, the SMA was occluded immediately distal to the aorta for 60 minutes. After that, the clamp was removed and the reperfusion period began. In group III, 30 minutes before the start of reperfusion, 10 mg/kg melatonin was administered intraperitonally. All animals were sacrified 24 hours after reperfusion. Tissue samples were collected to evaluate the I/R-induced intestinal injury and bacterial translocation (BT). There was a statistically significant increase in myeloperoxidase activity, malondialdehyde levels and in the incidence of bacterial translocation in group II, along with a decrease in glutathione levels. These investigated parameters were found to be normalized in melatonin treated animals (group III). We conclude that melatonin prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.

The protective effect of SCR(15-18) on cerebral ischemia-reperfusion injury.

PubMed

Li, Shu; Xian, Jinhong; He, Li; Luo, Xue; Tan, Bing; Yang, Yongtao; Liu, Gaoke; Wang, Zhengqing

2011-10-01

Soluble complement receptor type 1 (sCR1), a potent inhibitor of complement activation, has been shown to protect brain cells against cerebral ischemic/reperfusion (CI/R) injury due to its decay-accelerating activity for C3/C5 convertase and co-factor activity for C3b/C4b degradation. However, the effect of short consensus repeats (SCRs) 15-18, one of active domains of sCR1 with high C3b/C4b degradability, has not been demonstrated. Here, we investigated the protective effect of recombinant SCR(15-18) protein in middle cerebral artery occlusion (MCAO)-induced focal CI/R injury. Recombinant SCR(15-18) protein was successfully expressed in Escherichia coli and refolded to its optimal bioactivity. Seventy-five Sprague-Dawley rats were randomly assigned into three groups: sham-operated group, CI/R group, and SCR(15-18)+CI/R group pretreated with 20 mg/kg SCR(15-18) protein. After 2 hours of MCAO and subsequent 24 hours of reperfusion, rats were evaluated for neurological deficits and cerebral infarction. Polymorphonuclear leukocyte accumulation, C3b deposition, and morphological changes in cerebral tissue were also estimated. SCR(15-18) pretreatment induced a 20% reduction of infarct size and an improvement of neurological function with 22·2% decrease of neurological deficit scores. Inhibition of cerebral neutrophils infiltration by SCR(15-18) was indicated from the reduction of myeloperoxidase activity in SCR(15-18)+CI/R rats. Decreased C3b deposition and improved morphological changes were also found in cerebral tissue of SCR(15-18)-treated rats. Our studies suggest a definitive moderately protective effect of SCR(15-18) against CI/R damage and provide preclinical experimental evidence supporting the possibility of using it as a small anti-complement therapeutic agent for CI/R injury therapy.

Protective effect of extract of Cordyceps sinensis in middle cerebral artery occlusion-induced focal cerebral ischemia in rats

PubMed Central

2010-01-01

Background Ischemic hypoxic brain injury often causes irreversible brain damage. The lack of effective and widely applicable pharmacological treatments for ischemic stroke patients may explain a growing interest in traditional medicines. From the point of view of "self-medication" or "preventive medicine," Cordyceps sinensis was used in the prevention of cerebral ischemia in this paper. Methods The right middle cerebral artery occlusion model was used in the study. The effects of Cordyceps sinensis (Caterpillar fungus) extract on mortality rate, neurobehavior, grip strength, lactate dehydrogenase, glutathione content, Lipid Peroxidation, glutathione peroxidase activity, glutathione reductase activity, catalase activity, Na+K+ATPase activity and glutathione S transferase activity in a rat model were studied respectively. Results Cordyceps sinensis extract significantly improved the outcome in rats after cerebral ischemia and reperfusion in terms of neurobehavioral function. At the same time, supplementation of Cordyceps sinensis extract significantly boosted the defense mechanism against cerebral ischemia by increasing antioxidants activity related to lesion pathogenesis. Restoration of the antioxidant homeostasis in the brain after reperfusion may have helped the brain recover from ischemic injury. Conclusions These experimental results suggest that complement Cordyceps sinensis extract is protective after cerebral ischemia in specific way. The administration of Cordyceps sinensis extract significantly reduced focal cerebral ischemic/reperfusion injury. The defense mechanism against cerebral ischemia was by increasing antioxidants activity related to lesion pathogenesis. PMID:20955613

Protective effect of extract of Cordyceps sinensis in middle cerebral artery occlusion-induced focal cerebral ischemia in rats.

PubMed

Liu, Zhenquan; Li, Pengtao; Zhao, Dan; Tang, Huiling; Guo, Jianyou

2010-10-19

Ischemic hypoxic brain injury often causes irreversible brain damage. The lack of effective and widely applicable pharmacological treatments for ischemic stroke patients may explain a growing interest in traditional medicines. From the point of view of "self-medication" or "preventive medicine," Cordyceps sinensis was used in the prevention of cerebral ischemia in this paper. The right middle cerebral artery occlusion model was used in the study. The effects of Cordyceps sinensis (Caterpillar fungus) extract on mortality rate, neurobehavior, grip strength, lactate dehydrogenase, glutathione content, Lipid Peroxidation, glutathione peroxidase activity, glutathione reductase activity, catalase activity, Na+K+ATPase activity and glutathione S transferase activity in a rat model were studied respectively. Cordyceps sinensis extract significantly improved the outcome in rats after cerebral ischemia and reperfusion in terms of neurobehavioral function. At the same time, supplementation of Cordyceps sinensis extract significantly boosted the defense mechanism against cerebral ischemia by increasing antioxidants activity related to lesion pathogenesis. Restoration of the antioxidant homeostasis in the brain after reperfusion may have helped the brain recover from ischemic injury. These experimental results suggest that complement Cordyceps sinensis extract is protective after cerebral ischemia in specific way. The administration of Cordyceps sinensis extract significantly reduced focal cerebral ischemic/reperfusion injury. The defense mechanism against cerebral ischemia was by increasing antioxidants activity related to lesion pathogenesis.

Does acupuncture ameliorate motor impairment after stroke? An assessment using the CatWalk gait system.

PubMed

Cao, Yan; Sun, Ning; Yang, Jing-Wen; Zheng, Yang; Zhu, Wen; Zhang, Zhen-Hua; Wang, Xue-Rui; Shi, Guang-Xia; Liu, Cun-Zhi

2017-07-01

The effect of acupuncture on gait deficits after stroke is uncertain. This animal study was designed to determine whether acupuncture improves gait impairment following experimentally induced ischemic stroke. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in rats. After 7 days' of acupuncture treatment, assessment of gait changes using the CatWalk automated gait analysis system was performed. Comparison of the CatWalk gait parameters among the groups showed that gait function was impaired after ischemic stroke and acupuncture treatment was effective in improving a variety of gait parameters including intensity, stance and swing time, swing speed and stride length at postoperative day 8. This study demonstrates a beneficial effect of acupuncture on gait impairment in rats following ischemic stroke. Further studies aimed to investigate the effects of acupuncture at different stages during stroke using the CatWalk system are required. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of the static occlusion by "occlusal surface settling" in the Cerec 3D software.

PubMed

Späth, C; Kordass, B

2006-04-01

The adjustment of the static occlusion can be automated in computer-based systems. The Cerec 3D software makes it possible to take preformed occlusal surfaces from a database and adapt them to the antagonist. In this adaptation (settling), the CAD occlusal surface "settles" as whole or each cusp individually into the occlusal surface of the antagonist until stable occlusion is reached. Two occlusal surface shapes were compared: Vita Physiodens and Lee Culp. An index was formed from the number, quality, and position of the occlusal contacts for 35 model cases (25 molars, 10 premolars). With regard to the settling of the total occlusal surfaces, there were no differences between the two occlusal surface shapes. In "cusp settling" of the molars, Vita Physiodens performed significantly better. In the comparison of the 1st with the 3rd settling process, significant improvements occurred the 3rd time in many cases when settling individual cusps, but in clearly fewer cases in the settling process of the total occlusal surface. The Lee Culp tooth occlusion improved especially after the 3rd settling process of individual cusps. It is therefore expedient to combine both settling versions with one another.

Anti-excitotoxic effects of cannabidiol are partly mediated by enhancement of NCX2 and NCX3 expression in animal model of cerebral ischemia.

PubMed

Khaksar, Sepideh; Bigdeli, Mohammad Reza

2017-01-05

Excitotoxicity and imbalance of sodium and calcium homeostasis trigger pathophysiologic processes in cerebral ischemia which can accelerate neuronal death. Neuroprotective role of cannabidiol (CBD), one of the main non-psychoactive phytocannabinoids of the cannabis plant, has attracted attention of many researchers in the neurodegenerative diseases studies. The present investigation was designed to determine whether cannabidiol can alleviate the severity of ischemic damages and if it is able to exert its anti-excitotoxic effects through sodium and calcium regulation. By using stereotaxic surgery, a guide cannula was implanted into the lateral ventricle. Cannabidiol (50, 100, and 200ng/rat; i.c.v.) was administrated for 5 consecutive days. After pretreatment, the rats were subjected to 60min of right middle cerebral artery occlusion (MCAO). After 24h, neurological deficits score, infarct volume, brain edema, and blood-brain barrier (BBB) permeability in total of hemisphere, cortex, piriform cortex-amygdala, and striatum were assessed. The expression of Na + /Ca 2+ exchangers (NCXs) protein as an endogenous target in these regions was also studied. The present results indicate that administration of cannabidiol (100 and 200ng/rat) in the MCAO-induced cerebral ischemia caused a remarkable reduction in neurological deficit, infarction, brain edema, and BBB permeability in comparison with the vehicle group. Up-regulation of NCX2 and NCX3 in cannabidiol-received groups was also observed. These findings support the view that the reduction of ischemic injuries elicited by cannabidiol can be at least partly due to the enhancement of NCX protein expression and its cerebro-protective role in those cerebral territories supplied by MCA. Copyright © 2016 Elsevier B.V. All rights reserved.

Occlusion and rupture of ex vivo capillary bifurcation due to acoustic droplet vaporization

NASA Astrophysics Data System (ADS)

Feng, Yi; Qin, Dui; Zhang, Jun; Zhang, Lei; Bouakaz, Ayache; Wan, Mingxi

2018-06-01

Gas embolotherapy (GE) consists in the occlusion of tumor blood vessels using gas emboli induced by acoustic droplet vaporization (ADV), to create tumor starvation and localized drug delivery. Therefore, the occlusion and rupture of capillary bifurcation due to ADV was investigated in an ex vivo rat mesentery model using a confocal acousto-optical high-speed microscope system. Following ADV bubble formation, coalescence, and translational movement, the growing bubbles lodged in and then occluded two different capillary bifurcations. Capillary rupture was induced at the bubble lodging area, immediately followed by gas extravasation and bubble dislodging. Before and after bubble lodgment/occlusion, a local microvessel invagination was observed due to the interactions between ADV bubbles and the microvessel itself, indicating a contribution to the capillary rupture. Understanding the transient dynamics of ADV bubble, the bubble-microvessel interaction and the consequent mechanical bio-effects in GE is of the paramount importance for developing and applying this approach in clinical practice.

Nobiletin improves propofol-induced neuroprotection via regulating Akt/mTOR and TLR 4/NF-κB signaling in ischemic brain injury in rats.

PubMed

Zheng, Yuzhen; Bu, Jinmei; Yu, Liang; Chen, Jun; Liu, Haigen

2017-07-01

Stroke is regarded as one of the main health concerns globally, presenting with high mortality and morbidity rates. Cerebral ischemic damage and infarction are critically associated with stroke. Various mechanisms related to inflammation, oxidative stress and excitotoxicity are found to be involved in ischemic damage. Very short time period for treatment has necessitated in development of more effective neuroprotective agents. Study aimed in investigated the effects of nobiletin on experimentally induced ischemic brain injury and also to assess whether nobiletin potentiated the neuroprotective effects of propofol. Male Sprague-Dawley rats were subjected to ischemia/reperfusion (I/R) injury. Induction of cerebral infarction and I/R was done by middle cerebral artery occlusion (MCAO). Nobiletin (100 or 200mg/kg b.wt.) was intragastrically administered to rats for 9 days before ischemia induction and on the day of induction nobiletin was administered an hour prior. Separate group of rats were post-conditioned with propofol (50mg/kg/h; i.v.) for 30min following 24h of reperfusion. Propofol post-conditioning either with or without administration of nobiletin prior I/R injury attenuated pulmonary edema, neuronal apoptosis and reduced cerebral infarct volume. Overproduction of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and nitric oxide following I/R were reduced. Propofol either alone or with prior nobiletin treatment had down-regulated TLR4 and TLR4-mediated NF-κB signaling and caused activation of Akt/mTOR cascade. Propofol post-conditioning either with nobiletin prior I/R injury was found to be more effective than propofol alone, suggesting the positive effects of nobiletin on propofol-mediated anti-inflammatory and neuroprotective effects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Development of occlusive neointimal lesions in distal pulmonary arteries of endothelin B receptor-deficient rats: a new model of severe pulmonary arterial hypertension.

PubMed

Ivy, D Dunbar; McMurtry, Ivan F; Colvin, Kelley; Imamura, Masatoshi; Oka, Masahiko; Lee, Dong-Seok; Gebb, Sarah; Jones, Peter Lloyd

2005-06-07

Human pulmonary arterial hypertension (PAH) is characterized by proliferation of vascular smooth muscle and, in its more severe form, by the development of occlusive neointimal lesions. However, few animal models of pulmonary neointimal proliferation exist, thereby limiting a complete understanding of the pathobiology of PAH. Recent studies of the endothelin (ET) system demonstrate that deficiency of the ET(B) receptor predisposes adult rats to acute and chronic hypoxic PAH, yet these animals fail to develop neointimal lesions. Herein, we determined and thereafter showed that exposure of ET(B) receptor-deficient rats to the endothelial toxin monocrotaline (MCT) leads to the development of neointimal lesions that share hallmarks of human PAH. The pulmonary hemodynamic and morphometric effects of 60 mg/kg MCT in control (MCT(+/+)) and ET(B) receptor-deficient (MCT(sl/sl)) rats at 6 weeks of age were assessed. MCT(sl/sl) rats developed more severe PAH, characterized by elevated pulmonary artery pressure, diminished cardiac output, and right ventricular hypertrophy. In MCT(sl/sl) rats, morphometric evaluation revealed the presence of neointimal lesions within small distal pulmonary arteries, increased medial wall thickness, and decreased arterial-to-alveolar ratio. In keeping with this, barium angiography revealed diminished distal pulmonary vasculature of MCT(sl/sl) rat lungs. Cells within neointimal lesions expressed smooth muscle and endothelial cell markers. Moreover, cells within neointimal lesions exhibited increased levels of proliferation and were located in a tissue microenvironment enriched with vascular endothelial growth factor, tenascin-C, and activated matrix metalloproteinase-9, factors already implicated in human PAH. Finally, assessment of steady state mRNA showed that whereas expression of ET(B) receptors was decreased in MCT(sl/sl) rat lungs, ET(A) receptor expression increased. Deficiency of the ET(B) receptor markedly accelerates the progression of

Development of Occlusive Neointimal Lesions in Distal Pulmonary Arteries of Endothelin B Receptor–Deficient Rats: A New Model of Severe Pulmonary Arterial Hypertension

PubMed Central

Ivy, D. Dunbar; McMurtry, Ivan F.; Colvin, Kelley; Imamura, Masatoshi; Oka, Masahiko; Lee, Dong-Seok; Gebb, Sarah; Jones, Peter Lloyd

2007-01-01

Background Human pulmonary arterial hypertension (PAH) is characterized by proliferation of vascular smooth muscle and, in its more severe form, by the development of occlusive neointimal lesions. However, few animal models of pulmonary neointimal proliferation exist, thereby limiting a complete understanding of the pathobiology of PAH. Recent studies of the endothelin (ET) system demonstrate that deficiency of the ETB receptor predisposes adult rats to acute and chronic hypoxic PAH, yet these animals fail to develop neointimal lesions. Herein, we determined and thereafter showed that exposure of ETB receptor–deficient rats to the endothelial toxin monocrotaline (MCT) leads to the development of neointimal lesions that share hallmarks of human PAH. Methods and Results The pulmonary hemodynamic and morphometric effects of 60 mg/kg MCT in control (MCT+/+) and ETB receptor–deficient (MCTsl/sl) rats at 6 weeks of age were assessed. MCTsl/sl rats developed more severe PAH, characterized by elevated pulmonary artery pressure, diminished cardiac output, and right ventricular hypertrophy. In MCTsl/sl rats, morphometric evaluation revealed the presence of neointimal lesions within small distal pulmonary arteries, increased medial wall thickness, and decreased arterial-to-alveolar ratio. In keeping with this, barium angiography revealed diminished distal pulmonary vasculature of MCTsl/sl rat lungs. Cells within neointimal lesions expressed smooth muscle and endothelial cell markers. Moreover, cells within neointimal lesions exhibited increased levels of proliferation and were located in a tissue microenvironment enriched with vascular endothelial growth factor, tenascin-C, and activated matrix metalloproteinase-9, factors already implicated in human PAH. Finally, assessment of steady state mRNA showed that whereas expression of ETB receptors was decreased in MCTsl/sl rat lungs, ETA receptor expression increased. Conclusions Deficiency of the ETB receptor markedly

Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms.

PubMed

Ikeda, Yohei; Yoshimura, Norihiko; Hori, Yoshiro; Horii, Yosuke; Ishikawa, Hiroyuki; Yamazaki, Motohiko; Noto, Yoshiyuki; Aoyama, Hidefumi

2014-12-01

The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as "decreased," "slightly decreased," and "preserved". Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P<0.001) between the two groups. HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group (33.8 ± 8.2 HU vs. 11.9 ± 6.1 HU, P<0.001). There was no significant difference in HUs for the entire lesion between the non-occlusive (33.8 ± 8.2 HU) and corresponding normal group (34.5 ± 6.8 HU; P=0.294). Iodine perfusion tended to be visually and quantitatively preserved in lungs with

Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model

PubMed Central

Garbuzova-Davis, Svitlana; Rodrigues, Maria C. O.; Hernandez-Ontiveros, Diana G.; Tajiri, Naoki; Frisina-Deyo, Aric; Boffeli, Sean M.; Abraham, Jerry V.; Pabon, Mibel; Wagner, Andrew; Ishikawa, Hiroto; Shinozuka, Kazutaka; Haller, Edward; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesario V.

2013-01-01

Background Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. Methodology/Principal Findings In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. Conclusions/Significance These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke. PMID:23675488

White matter changes after stroke in type 2 diabetic rats measured by diffusion magnetic resonance imaging.

PubMed

Ding, Guangliang; Chen, Jieli; Chopp, Michael; Li, Lian; Yan, Tao; Davoodi-Bojd, Esmaeil; Li, Qingjiang; Davarani, Siamak Pn; Jiang, Quan

2017-01-01

Diffusion-related magnetic resonance imaging parametric maps may be employed to characterize white matter of brain. We hypothesize that entropy of diffusion anisotropy may be most effective for detecting therapeutic effects of bone marrow stromal cell treatment of ischemia in type 2 diabetes mellitus rats. Type 2 diabetes mellitus was induced in adult male Wistar rats. These rats were then subjected to 2 h of middle cerebral artery occlusion, and received bone marrow stromal cell (5 × 10 6 , n = 8) or an equal volume of saline (n = 8) via tail vein injection at three days after middle cerebral artery occlusion. Magnetic resonance imaging was performed on day one and then weekly for five weeks post middle cerebral artery occlusion. The diffusion metrics complementarily permitted characterization of axons and axonal myelination. All six magnetic resonance imaging diffusion metrics, confirmed by histological measures, demonstrated that bone marrow stromal cell treatment significantly (p < 0.05) improved magnetic resonance imaging diffusion indices of white matter in type 2 diabetes mellitus rats after middle cerebral artery occlusion compared with the saline-treated rats. Superior to the fractional anisotropy metric that provided measures related to organization of neuronal fiber bundles, the entropy metric can also identify microstructures and low-density axonal fibers of cerebral tissue after stroke in type 2 diabetes mellitus rats. © The Author(s) 2015.

White matter changes after stroke in type 2 diabetic rats measured by diffusion magnetic resonance imaging

PubMed Central

Ding, Guangliang; Chen, Jieli; Chopp, Michael; Li, Lian; Yan, Tao; Davoodi-Bojd, Esmaeil; Li, Qingjiang; Davarani, Siamak PN

2015-01-01

Diffusion-related magnetic resonance imaging parametric maps may be employed to characterize white matter of brain. We hypothesize that entropy of diffusion anisotropy may be most effective for detecting therapeutic effects of bone marrow stromal cell treatment of ischemia in type 2 diabetes mellitus rats. Type 2 diabetes mellitus was induced in adult male Wistar rats. These rats were then subjected to 2 h of middle cerebral artery occlusion, and received bone marrow stromal cell (5 × 106, n = 8) or an equal volume of saline (n = 8) via tail vein injection at three days after middle cerebral artery occlusion. Magnetic resonance imaging was performed on day one and then weekly for five weeks post middle cerebral artery occlusion. The diffusion metrics complementarily permitted characterization of axons and axonal myelination. All six magnetic resonance imaging diffusion metrics, confirmed by histological measures, demonstrated that bone marrow stromal cell treatment significantly (p < 0.05) improved magnetic resonance imaging diffusion indices of white matter in type 2 diabetes mellitus rats after middle cerebral artery occlusion compared with the saline-treated rats. Superior to the fractional anisotropy metric that provided measures related to organization of neuronal fiber bundles, the entropy metric can also identify microstructures and low-density axonal fibers of cerebral tissue after stroke in type 2 diabetes mellitus rats. PMID:26685128

Zinc translocation accelerates infarction after mild transient focal ischemia.

PubMed

Lee, J-M; Zipfel, G J; Park, K H; He, Y Y; Hsu, C Y; Choi, D W

2002-01-01

Excess release of chelatable zinc (Zn(2+)) from central synaptic vesicles may contribute to the pathogenesis of selective neuronal cell death following transient forebrain ischemia, but a role in neurodegeneration after focal ischemia has not been defined. Adult male Long-Evans rats subjected to middle cerebral artery occlusion (MCAO) for 30 min followed by reperfusion developed delayed cerebral infarction reaching completion 3 days after the insult. One day after the insult, many degenerating cerebral neurons exhibited increased intracellular Zn(2+), and some labeled with the antibody against activated caspase-3. I.c.v. administration of the Zn(2+) chelator, EDTA saturated with equimolar Ca(2+) (CaEDTA), 15 min prior to ischemia attenuated subsequent Zn(2+) translocation into cortical neurons, and reduced infarct volume measured 3 days after ischemia. Although the protective effect of CaEDTA at this endpoint was substantial (about 70% infarct reduction), it was lost when insult severity was increased (from 30 to 60 min MCAO), or when infarct volume was measured at a much later time point (14 days instead of 3 days after ischemia). These data suggest that toxic Zn(2+) translocation, from presynaptic terminals to post-synaptic cell bodies, may accelerate the development of cerebral infarction following mild transient focal ischemia.

Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

PubMed

Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

2013-01-01

To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

Non-invasive detection of matrix-metalloproteinase activity in a mouse model of cerebral ischemia using multispectral optoacoustic tomography

NASA Astrophysics Data System (ADS)

Ni, Ruiqing; Vaas, Markus; Ren, Wuwei; Klohs, Jan

2018-02-01

Matrix metalloproteinases (MMPs) play important roles in the pathophysiology of cerebral ischemia. Here we visualized in vivo MMP activity in the transient middle cerebral artery occlusion (tMCAO) mouse model using multispectral optoacoustic imaging (MSOT) with a MMP-activatable probe. MSOT data was co-registered with structural magnetic resonance imaging (MRI) obtained at 7 T for localization of signal distribution. We demonstrated upregulated MMP signal within the focal ischemic lesion in the tMCAO mouse model using MSOT/MRI multimodal imaging. This convenient non-invasive method will allow repetitive measurement following the time course of MMP-lesion development in ischemic stroke animal model.

Neuronal Sodium Channels in Neurodegeneration and Neuroprotection

DTIC Science & Technology

2002-06-01

following 2 h MCAo/ reperfusion injury Group’ Baselineb 2 h 4 h 6 h $ 24 1h Vehicle 37.0±0.7 38.3±0.7 37.1 ±0.8 37.5 ±0.7 36.6±0.8 RS (0.01 mg/kg) 36.4-±0.3...brain injury caused by middle cerebral neuronal cell death caused by ischemia results from artery occlusion (MCAo) for 2h followed by reperfusion a...expression following cerebral ischemia study, was delayed post- injury (i.e. > 2 -6h post- involves the up-regulation of several gene families injury ). This

Rapamycin preconditioning attenuates transient focal cerebral ischemia/reperfusion injury in mice.

PubMed

Yin, Lele; Ye, Shasha; Chen, Zhen; Zeng, Yaoying

2012-12-01

Rapamycin, an mTOR inhibitor and immunosuppressive agent in clinic, has protective effects on traumatic brain injury and neurodegenerative diseases. But, its effects on transient focal ischemia/reperfusion disease are not very clear. In this study, we examined the effects of rapamycin preconditioning on mice treated with middle cerebral artery occlusion/reperfusion operation (MCAO/R). We found that the rapamycin preconditioning by intrahippocampal injection 20 hr before MCAO/R significantly improved the survival rate and longevity of mice. It also decreased the neurological deficit score, infracted areas and brain edema. In addition, rapamycin preconditioning decreased the production of NF-κB, TNF-α, and Bax, but not Bcl-2, an antiapoptotic protein in the ischemic area. From these results, we may conclude that rapamycin preconditioning attenuate transient focal cerebral ischemia/reperfusion injury and inhibits apoptosis induced by MCAO/R in mice.

Imaging cortical absorption, scattering, and hemodynamic response during ischemic stroke using spatially modulated near-infrared illumination

NASA Astrophysics Data System (ADS)

Abookasis, David; Lay, Christopher C.; Mathews, Marlon S.; Linskey, Mark E.; Frostig, Ron D.; Tromberg, Bruce J.

2009-03-01

We describe a technique that uses spatially modulated near-infrared (NIR) illumination to detect and map changes in both optical properties (absorption and reduced scattering parameters) and tissue composition (oxy- and deoxyhemoglobin, total hemoglobin, and oxygen saturation) during acute ischemic injury in the rat barrel cortex. Cerebral ischemia is induced using an open vascular occlusion technique of the middle cerebral artery (MCA). Diffuse reflected NIR light (680 to 980 nm) from the left parietal somatosensory cortex is detected by a CCD camera before and after MCA occlusion. Monte Carlo simulations are used to analyze the spatial frequency dependence of the reflected light to predict spatiotemporal changes in the distribution of tissue absorption and scattering properties in the brain. Experimental results from seven rats show a 17+/-4.7% increase in tissue concentration of deoxyhemoglobin and a 45+/-3.1, 23+/-5.4, and 21+/-2.2% decrease in oxyhemoglobin, total hemoglobin concentration and cerebral tissue oxygen saturation levels, respectively, 45 min following induction of cerebral ischemia. An ischemic index (Iisch=ctHHb/ctO2Hb) reveals an average of more then twofold contrast after MCAo. The wavelength-dependence of the reduced scattering (i.e., scatter power) decreased by 35+/-10.3% after MCA occlusion. Compared to conventional CCD-based intrinsic signal optical imaging (ISOI), the use of structured illumination and model-based analysis allows for generation of separate maps of light absorption and scattering properties as well as tissue hemoglobin concentration. This potentially provides a powerful approach for quantitative monitoring and imaging of neurophysiology and metabolism with high spatiotemporal resolution.

Numeric simulation of occlusal interferences in molars restored with ultrathin occlusal veneers.

PubMed

Magne, Pascal; Cheung, Raymond

2017-01-01

Selecting material for a minimally invasive occlusal veneer reconstruction concept requires an understanding of how stresses are distributed during functional and parafunctional forces. The purpose of this in vitro study was to investigate stress distribution in a maxillary molar restored with ultrathin occlusal veneers and subjected by an antagonistic mandibular molar to clenching and working and nonworking movements. A maxillary first molar was modeled from microcomputed tomography (micro-CT) data, using medical image processing software, stereolithography editing/optimizing software, and finite element software. Simulated ultrathin occlusal veneer materials were used. The mandibular molar antagonist was a solid nondeformable geometric entity. Loads simulated clenching, working, and nonworking movements with loading of 500 N. The values of the maximum principal stress were recorded. In the clenching load situation, maximum tensile stresses were located at the occlusal veneer (52 MPa for composite resin versus 47 MPa for ceramic). In the working movement, significant additional tensile stresses were found on the palatal root (87 MPa for composite resin and 85 MPa for ceramic). In the nonworking movement, tensile stress on the ultrathin occlusal veneer increased to 118 MPa for composite resin and 143 MPa for ceramic veneers. Tensile stress peaks shifted to the mesiobuccal root (75 MPa for composite resin and 74 MPa for ceramic). The topography of stresses generated by the various occlusal interferences were clearly identified. Significant tensile stress concentrations were found within the restoration's occlusal topography and root, with the nonworking interference being the most harmful and also the most revealing of the difference between the composite resin and ceramic ultrathin occlusal veneers. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Arctigenin attenuates ischemic stroke via SIRT1-dependent inhibition of NLRP3 inflammasome.

PubMed

Zhang, Shimeng; Jiang, Liangjun; Che, Fengyuan; Lu, Yucheng; Xie, Zhongxiang; Wang, Hao

2017-11-04

Arctigenin (ARC), a phenylpropanoid dibenzylbutyrolactone lignan derived from Arctium lappa L, has been reported to protect against cerebral ischemia injury in rats, but the underlying mechanism is unclear. In this study, we investigated whether ARC ameliorated ischemic stroke by inhibiting NLRP3 inflammasome-derived neuroinflammation and whether SIRT1 signaling was involved in this process. ARC (20 mg/kg) or vehicle were intraperitoneally injected to Sprague-Dawley rats for 3 days before middle cerebral artery occlusion (MCAO) surgery performed. The infarct volume, neurological score, brain water content, neuroinflammation, NLRP3 inflammasome activation and SIRT1 protein expression were assessed. Furthermore, we also investigated whether ARC protected against cerebral ischemia via SIRT1-dependent inhibition of NLRP3 inflammasome by administrating EX527, a specific SIRT1 inhibitor, under oxygen-glucose deprivation (OGD) condition. We found that ARC pretreatment decreased infarct volume, neurological score and brain water content. Moreover, ARC treatment effectively inhibited cerebral ischemia induced NLRP3 inflammasome activation and IL-1β, IL-18 secretion both in vivo and in vitro. Futhermore, ARC treatment activated Silent information regulator 1 (SIRT1) singnaling in the brain. Importantly, suppress of SIRT1 reversed the inhibitory effect of ARC on NLRP3 inflammasome activation. Taken together our results demonstrated that ARC may confer protection against ischemic stroke by inhibiting NLRP3 inflammasome activation. The activation of SIRT1 signaling pathway may contribute to the neuroprotection of ARC in MCAO. Copyright © 2017 Elsevier Inc. All rights reserved.

Green tea polyphenols alleviate early BBB damage during experimental focal cerebral ischemia through regulating tight junctions and PKCalpha signaling.

PubMed

Liu, Xiaobai; Wang, Zhenhua; Wang, Ping; Yu, Bo; Liu, Yunhui; Xue, Yixue

2013-07-21

It has been supposed that green tea polyphenols (GTPs) have neuroprotective effects on brain damage after brain ischemia in animal experiments. Little is known regarding GTPs' protective effects against the blood-brain barrier (BBB) disruption after ischemic stroke. We investigated the effects of GTPs on the expression of claudin-5, occludin, and ZO-1, and the corresponding cellular mechanisms involved in the early stage of cerebral ischemia. Male Wistar rats were subjected to a middle cerebral artery occlusion (MCAO) for 0, 30, 60, and 120 min. GTPs (400 mg/kg/day) or vehicle was administered by intragastric gavage twice a day for 30 days prior to MCAO. At different time points, the expression of claudin-5, occludin, ZO-1, and PKCα signaling pathway in microvessel fragments of cerebral ischemic tissue were evaluated. GTPs reduced BBB permeability at 60 min and 120 min after ischemia as compared with the vehicle group. Transmission electron microscopy also revealed that GTPs could reverse the opening of tight junction (TJ) barrier at 60 min and 120 min after MACO. The decreased mRNA and protein expression levels of claudin-5, occludin, and ZO-1 in microvessel fragments of cerebral ischemic tissue were significantly prevented by treatment with GTPs at the same time points after ischemia in rats. Furthermore, GTPs could attenuate the increase in the expression levels of PKCα mRNA and protein caused by cerebral ischemia. These results demonstrate that GTPs may act as a potential neuroprotective agent against BBB damage at the early stage of focal cerebral ischemia through the regulation of TJ and PKCα signaling.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference.

PubMed

Ono, Yumie; Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-11-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near-infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task-related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task-related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference

PubMed Central

Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-01-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near‐infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task‐related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task‐related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD. PMID:29744159

Blood flow of the right and left submandibular gland during unilateral carotid artery occlusion in rat: role of nitric oxide.

PubMed

Vág, J; Hably, C; Fazekas, A; Bartha, J

1999-01-01

The aim of the present study was to investigate the effect of unilateral carotid artery occlusion on the blood flow of submandibular gland in anesthetized rats and identify the role of nitric oxide (NO) in blood flow changes after the artery occlusion. L-NAME (N omega-nitro-L-arginine-methyl-ester; 10 mg/kg/day, per os) dissolved in tap water was used to block nitric oxide synthase. Glandular blood flow was measured using Sapirstein's indicator (86Rb) distribution technique. In the control animals the blood flow of left (ligated side) submandibular gland was lower than in the right (unligated side) one (right: 76.4+/-15.4 ml/min/100 g, 64.1+/-13.4 ml/min/100 g, p<0.01). The blood flow of submandibular glands decreased in NOS blocked group versus control. The vascular resistance after L-NAME treatment was elevated (control: 11+/-2.3 R/kg, L-NAME: 17.5+/-4.1 R/kg, p<0.001). In L-NAME group the difference between blood flow value of the left and right submandibular gland was significantly lower than in the control group (control: -16%, NAME: -8%, p<0.01). The maintenance of the blood flow in the left submandibular gland during ligation of the left common carotid artery could be due to the good vascular anastomotic system at these regions and adaptation of the submandibular vessels to the decreased perfusion pressure. Nitric oxide may have a role in the regulation of blood flow tinder this condition.

An Antagomir to MicroRNA-106b-5p Ameliorates Cerebral Ischemia and Reperfusion Injury in Rats Via Inhibiting Apoptosis and Oxidative Stress.

PubMed

Li, Pengfei; Shen, Meihong; Gao, Feng; Wu, Jinping; Zhang, Jiahui; Teng, Fengmeng; Zhang, Chunbing

2017-05-01

We previously observed that microRNA miR-106b-5p significantly increased in serum of patients with acute ischemic stroke. The present study was to determine whether miR-106b-5p antagomir can protect against cerebral ischemia/reperfusion (I/R) injury and elucidate its underlying mechanisms. Middle cerebral artery occlusion (MCAO) was operated on male Sprague Dawley rats. MiR-106b-5p antagomir significantly decreased neurological deficit scores, infarct volumes, and neuronal injury. Furthermore, miR-106b-5p antagomir markedly reduced malondialdehyde (MDA) content, restored superoxide dismutase (SOD) activity, increased the expression of myeloid cell leukemia-1 (Mcl-1) and B cell lymphoma-2 (Bcl-2), and decreased the expression of Bax in the ischemic cortex. In PC12 cells, miR-106b-5p inhibitor increased the Mcl-1 and Bcl-2 expression, which provided protection against glutamate-induced apoptosis and oxidative damage, as evidenced by decreased lactate dehydrogenase (LDH) release, and enhanced SOD activity. Notably, luciferase reported assay proved Mcl-1 was the target gene of miR-106b-5p. In conclusion, our data indicates that the neuroprotective effects of miR-106b-5p antagomir on cerebral I/R injury are associated with its inhibition of apoptosis and oxidative stress, suggesting a potential therapeutic target for ischemic stroke.

Neuroprotection by Curcumin in Ischemic Brain Injury Involves the Akt/Nrf2 Pathway

PubMed Central

Wu, Jingxian; Li, Qiong; Wang, Xiaoyan; Yu, Shanshan; Li, Lan; Wu, Xuemei; Chen, Yanlin; Zhao, Jing; Zhao, Yong

2013-01-01

Oxidative damage plays a critical role in many diseases of the central nervous system. This study was conducted to determine the molecular mechanisms involved in the putative anti-oxidative effects of curcumin against experimental stroke. Oxygen and glucose deprivation/reoxygenation (OGD/R) was used to mimic ischemic insult in primary cultured cortical neurons. A rapid increase in the intracellular expression of NAD(P)H: quinone oxidoreductase1 (NQO1) induced by OGD was counteracted by curcumin post-treatment, which paralleled attenuated cell injury. The reduction of phosphorylation Akt induced by OGD was restored by curcumin. Consequently, NQO1 expression and the binding activity of nuclear factor-erythroid 2-related factor 2 (Nrf2) to antioxidant response element (ARE) were increased. LY294002 blocked the increase in phospho-Akt evoked by curcumin and abolished the associated protective effect. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion for 60 minutes. Curcumin administration significantly reduced infarct size. Curcumin also markedly reduced oxidative stress levels in middle cerebral artery occlusion (MCAO) rats; hence, these effects were all suppressed by LY294002. Taken together, these findings provide evidence that curcumin protects neurons against ischemic injury, and this neuroprotective effect involves the Akt/Nrf2 pathway. In addition, Nrf2 is involved in the neuroprotective effects of curcumin against oxidative damage. PMID:23555802

TRPV1 receptor-mediated expression of Toll-like receptors 2 and 4 following permanent middle cerebral artery occlusion in rats

PubMed Central

Hakimizadeh, Elham; Shamsizadeh, Ali; Roohbakhsh, Ali; Arababadi, Mohammad Kazemi; Hajizadeh, Mohammad Reza; Shariati, Mehdi; Fatemi, Iman; Moghadam-ahmadi, Amir; Bazmandegan, Gholamreza; Rezazadeh, Hossein; Allahtavakoli, Mohammad

2017-01-01

Objective(s): Stroke is known as a main cause of mortality and prolonged disability in adults. Both transient receptor potential V1 (TRPV1) channels and toll-like receptors (TLRs) are involved in mediating the inflammatory responses. In the present study, the effects of TRPV1 receptor activation and blockade on stroke outcome and gene expression of TLR2 and TLR4 were assessed following permanent middle cerebral artery occlusion in rats Materials and Methods: Eighty male Wistar rats were divided into four groups as follows: sham, vehicle, AMG9810 (TRPV1 antagonist) -treated and capsaicin (TRPV1 agonist) -treated. For Stroke induction, the middle cerebral artery was permanently occluded and then behavioral functions were evaluated 1, 3 and 7 days after stroke. Results: TRPV1 antagonism significantly reduced the infarct volume compared to the stroke group. Also, neurological deficits were decreased by AMG9810 seven days after cerebral ischemia. In the ledged beam-walking test, the slip ratio was enhanced following ischemia. AMG9810 decreased this index in stroke animals. However, capsaicin improved the ratio 3 and 7 days after cerebral ischemia. Compared to the sham group, the mRNA expression of TLR2 and TLR4 was significantly increased in the stroke rats. AMG9810 Administration significantly reduced the mRNA expression of TLR2 and TLR4. However, capsaicin did not significantly affect the gene expression of TLR2 and TLR4. Conclusion: Our results demonstrated that TRPV1 antagonism by AMG9810 attenuates behavioral function and mRNA expression of TLR2 and TLR4. Thus, it might be useful to shed light on future therapeutic strategies for the treatment of ischemic stroke. PMID:29085577

Morpho-histological assessment of the periodontal support structures under the action of excessive occlusal forces and under the influence of nicotine.

PubMed

Ispas, Ana; Mihu, Carmen Mihaela; Crăciun, Antarinia Maria; Constantiniuc, Mariana

2018-01-01

Smoking and occlusal trauma are two factors that can interfere with bone homeostasis. The aim of this study was to evaluate the histocellular changes occurring in the periodontal ligament and alveolar bone during the action of excessive occlusal forces, and to assess the influence of nicotine on the alveolar bone loss in teeth subjected to occlusal trauma. Fifty-six Wistar rats were randomized into seven groups (n=8). Animals were exposed to nicotine and occlusal trauma for 7, 14 and 30 days. Three groups were exposed to occlusal trauma alone, another three groups were exposed to occlusal trauma and nicotine, and one group was not exposed to any treatment. Periodontal lesions induced in the first stage (7-14 days) manifested by a moderate increase of the periodontal space, a multiplication, thickening and elongation of periodontal fibers, as well as their condensation in the middle area of the periradicular space. Regarding bone changes induced by occlusal trauma, groups 5 and 7 (occlusal trauma and nicotine administration) had higher bone losses compared to groups 1, 2, 3, 4 and 6. This study demonstrated that nicotine significantly affected the alveolar bone. The induced occlusal trauma caused obvious tissue damage. At the same time, it was found that nicotine enhanced alveolar bone resorption, increased tooth mobility and induced an exacerbation of inflammatory processes.

Tetramethylpyrazine-2'-O-sodium ferulate attenuates blood-brain barrier disruption and brain oedema after cerebral ischemia/reperfusion.

PubMed

Xu, S-H; Yin, M-S; Liu, B; Chen, M-L; He, G-W; Zhou, P-P; Cui, Y-J; Yang, D; Wu, Y-L

2017-07-01

Disruption of blood-brain barrier (BBB) and subsequent oedema are major causes of the pathogenesis in ischaemic stroke with which the current clinical therapy remains unsatisfied. In this study, we examined the therapeutic effect of tetramethylpyrazine-2'-O-sodium ferulate (TSF)-a novel analogue of tetramethylpyrazine in alleviating BBB breakdown and brain oedema after cerebral ischaemia/reperfusion (I/R). Then, we explored the potential mechanism of the protection on BBB disruption in cerebral I/R rat models. Male Sprague-Dawley rats (250-300 g) were subjected to 120 min middle cerebral artery occlusion (MCAO), followed by 48 h reperfusion. TSF (10.8, 18 and 30 mg kg -1 ) and ozagrel (18 mg kg -1 ) were administrated by intravenous injection immediately for the first time and then received the same dose every 24 h for 2 days. We found that TSF treatment significantly attenuated the cerebral water content, infarction volume and improved neurological outcomes in MCAO rats compared to I/R models. Moreover, we investigated the effect of TSF on the BBB for that cerebral oedema is closely related to the permeability of the BBB. We found that the permeability of BBB was improved significantly in TSF groups compared to I/R model group by Evans blue leakage testing. Furthermore, the expressions of tight junction (TJ) proteins junction adhesion molecule-1 and occludin significantly decreased, but the protein expression of matrix metalloproteinase-9 (MMP-9) and aquaporin 4 (AQP4) increased after cerebral I/R, all of which were alleviated by TSF treatment. In conclusion, TSF significantly reduced BBB permeability and brain oedema, which were correlated with regulating the expression of TJ proteins, MMP-9 and AQP4. These findings provide a novel approach to the treatment of ischaemic stroke.

The neuroprotective properties of the superoxide dismutase mimetic tempol correlate with its ability to reduce pathological glutamate release in a rodent model of stroke

PubMed Central

Dohare, Preeti; Hyzinski-García, María C.; Vipani, Aarshi; Bowens, Nicole H.; Nalwalk, Julia W.; Feustel, Paul J.; Keller, Richard W.; Jourd’heuil, David; Mongin, Alexander A.

2014-01-01

The contribution of oxidative stress to ischemic brain damage is well established. Nevertheless, for unknown reasons, several clinically tested antioxidant therapies failed to show benefits in human stroke. Based on our previous in vitro work, we hypothesized that the neuroprotective potency of antioxidants is related to their ability to limit release of the excitotoxic amino acids, glutamate and aspartate. We explored the effects of two antioxidants, tempol and edaravone, on amino acid release in the brain cortex, in a rat model of transient occlusion of the middle cerebral artery (MCAo). Amino acid levels were quantified using a microdialysis approach, with the probe positioned in the ischemic penumbra as verified by a laser Doppler technique. Two-hour MCAo triggered a dramatic increase in the levels of glutamate, aspartate, taurine and alanine. Microdialysate delivery of 10 mM tempol reduced the amino acid release by 60–80%, while matching levels of edaravone had no effect. In line with these latter data, an intracerebroventri-cular injection of tempol but not edaravone (500 nmols each, 15 minutes prior to MCAo) reduced infarction volumes by ~50% and improved neurobehavioral outcomes. In vitro assays showed that tempol was superior in removing superoxide anion, whereas edaravone was more potent in scavenging hydrogen peroxide, hydroxyl radical, and peroxynitrite. Overall, our data suggests that the neuroprotective properties of tempol are likely related to its ability to reduce tissue levels of the superoxide anion and pathological glutamate release, and, in such a way, limit progression of brain infarction within ischemic penumbra. These new findings may be instrumental in developing new antioxidant therapies for treatment of stroke. PMID:25224033

Neuroprotective effects of AT1 receptor antagonists after experimental ischemic stroke: what is important?

PubMed

Culman, Juraj; Jacob, Toni; Schuster, Sven O; Brolund-Spaether, Kjell; Brolund, Leonie; Cascorbi, Ingolf; Zhao, Yi; Gohlke, Peter

2017-09-01

The present study conducted in rats defines the requirements for neuroprotective effects of systemically administered AT1 receptor blockers (ARBs) in acute ischaemic stroke. The inhibition of central effects to angiotensin II (ANG II) after intravenous (i.v.) treatment with candesartan (0.3 and 3 mg/kg) or irbesartan and losartan (3 and 30 mg/kg) was employed to study the penetration of these ARBs across the blood-brain barrier. Verapamil and probenecid were used to assess the role of the transporters, P-glycoprotein and the multidrug resistance-related protein 2, in the entry of losartan and irbesartan into the brain. Neuroprotective effects of i.v. treatment with the ARBs were investigated after transient middle cerebral artery occlusion (MCAO) for 90 min. The treatment with the ARBs was initiated 3 h after the onset of MCAO and continued for two consecutive days. Blood pressure was continuously recorded before and during MCAO until 5.5 h after the onset of reperfusion. The higher dose of candesartan completely abolished, and the lower dose of candesartan and higher doses of irbesartan and losartan partially inhibited the drinking response to intracerebroventricular ANG II. Only 0.3 mg/kg candesartan improved the recovery from ischaemic stroke, and 3 mg/kg candesartan did not exert neuroprotective effects due to marked blood pressure reduction during reperfusion. Both doses of irbesartan and losartan had not any effect on the stroke outcome. An effective, long-lasting blockade of brain AT1 receptors after systemic treatment with ARBs without extensive blood pressure reductions is the prerequisite for neuroprotective effects in ischaemic stroke.

HDAC inhibitors mitigate ischemia-induced oligodendrocyte damage: potential roles of oligodendrogenesis, VEGF, and anti-inflammation

PubMed Central

Kim, Hyeon Ju; Chuang, De-Maw

2014-01-01

White matter injury is an important component of stroke pathology, but its pathophysiology and potential treatment remain relatively elusive and underexplored. We previously reported that after permanent middle cerebral artery occlusion (pMCAO), sodium butyrate (SB) and trichostatin A (TSA) induced neurogenesis via histone deacetylase (HDAC) inhibition in multiple ischemic brain regions in rats; these effects-which depended on activation of brain-derived neurotrophic factor (BDNF)-TrkB signaling-contributed to behavioral improvement. The present study found that SB or TSA robustly protected against ischemia-induced loss of oligodendrocytes detected by confocal microscopy of myelin basic protein (MBP) immunostaining in the ipsilateral subventricular zone (SVZ), striatum, corpus callosum, and frontal cortex seven days post-pMCAO. Co-localization of 5-bromo-2’-deoxyuridine (BrdU)+ and MBP+ cells after SB treatment suggested the occurrence of oligodendrogenesis. SB also strongly upregulated vascular endothelial growth factor (VEGF), which plays a major role in neurogenesis, angiogenesis, and functional recovery after stroke. These SB-induced effects were markedly suppressed by blocking the TrkB signaling pathway with K252a. pMCAO-induced activation of microglia (OX42+) and macrophages/monocytes (ED1+)-which has been linked to white matter injury-was robustly suppressed by SB in a K252a-sensitive manner. In addition, SB treatment largely blocked caspase-3+ and OX42+ cells in ipsilateral brain regions. Our results suggest that HDAC inhibitor-mediated protection against ischemia-induced oligodendrocyte loss may involve multiple mechanisms including oligodendrogenesis, VEGF upregulation, anti-inflammation, and caspase-3 downregulation. Taken together, the results suggest that post-insult treatment with HDAC inhibitors is a rational strategy to mitigate white matter injury following ischemic stroke. PMID:24936215

Contralateral Occlusion Test: The effect of external ear canal occlusion on hearing thresholds.

PubMed

Reis, Luis Roque; Fernandes, Paulo; Escada, Pedro

Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test. Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners. Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners. The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

[Effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patient with implant restoration].

PubMed

Wang, Rong; Xu, Xin

2015-12-01

To compare the effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patients with dental implant restoration. Twenty patients, each with a single edentulous posterior dentition with no distal dentition were selected, and divided into 2 groups. Patients in group A underwent original occlusion adjustment method and patients in group B underwent occlusal plane reduction technique. Ankylos implants were implanted in the edentulous space in each patient and restored with fixed prosthodontics single unit crown. Occlusion was adjusted in each restoration accordingly. Electromyograms were conducted to determine the effect of adjustment methods on occlusion and muscles of mastication 3 months and 6 months after initial restoration and adjustment. Data was collected and measurements for balanced occlusal measuring standards were obtained, including central occlusion force (COF), asymmetry index of molar occlusal force(AMOF). Balanced muscles of mastication measuring standards were also obtained including measurements from electromyogram for the muscles of mastication and the anterior bundle of the temporalis muscle at the mandibular rest position, average electromyogram measurements of the anterior bundle of the temporalis muscle at the intercuspal position(ICP), Astot, masseter muscle asymmetry index, and anterior temporalis asymmetry index (ASTA). Statistical analysis was performed using Student 's t test with SPSS 18.0 software package. Three months after occlusion adjustment, parameters of the original occlusion adjustment method were significantly different between group A and group B in balanced occlusal measuring standards and balanced muscles of mastication measuring standards. Six months after occlusion adjustment, parameters of the original occlusion adjustment methods were significantly different between group A and group B in balanced muscles of mastication measuring standards, but was no significant difference in balanced

TOWARD PRECISION PHOTOMETRY FOR THE ELT ERA: THE DOUBLE SUBGIANT BRANCH OF NGC 1851 OBSERVED WITH THE GEMINI/GeMS MCAO SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turri, P.; McConnachie, A. W.; Stetson, P. B.

2015-10-01

The Extremely Large Telescopes currently under construction have a collecting area that is an order of magnitude larger than the present largest optical telescopes. For seeing-limited observations the performance will scale as the collecting area, but with the successful use of adaptive optics (AO), for many applications it will scale as D{sup 4} (where D is the diameter of the primary mirror). Central to the success of the ELTs, therefore, is the successful use of multi-conjugate adaptive optics (MCAO) which applies a high degree of correction over a field of view larger than the few arcseconds that limits classical AOmore » systems. In this Letter, we report on the analysis of crowded field images taken on the central region of the galactic globular cluster NGC 1851 in the K{sub s} band using the Gemini Multi-conjugate Adaptive Optics System (GeMS) at the Gemini South Telescope, the only science-grade MCAO system in operation. We use this cluster as a benchmark to verify the ability to achieve precise near-infrared photometry by presenting the deepest K{sub s} photometry in crowded fields ever obtained from the ground. We construct a color–magnitude diagram in combination with the F606W band from the Hubble Space Telescope/Advanced Camera for Surveys. As well as detecting the “knee” in the lower main sequence at K{sub s} ≃ 20.5, we also detect the double subgiant branch of NGC 1851, which demonstrates the high photometric accuracy of GeMS in crowded fields.« less

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion.

PubMed

Quartu, Marina; Serra, Maria P; Boi, Marianna; Pillolla, Giuliano; Melis, Tiziana; Poddighe, Laura; Del Fiacco, Marina; Falconieri, Danilo; Carta, Gianfranca; Murru, Elisabetta; Cordeddu, Lina; Piras, Antonio; Collu, Maria; Banni, Sebastiano

2012-01-12

Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of Pistacia lentiscus L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma. Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone. BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA). Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

PubMed Central

2012-01-01

Background Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of Pistacia lentiscus L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma. Methods Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone. Results BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA). Conclusions Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury. PMID:22239952

Acute stroke with major intracranial vessel occlusion: Characteristics of cardioembolism and atherosclerosis-related in situ stenosis/occlusion.

PubMed

Horie, Nobutaka; Tateishi, Yohei; Morikawa, Minoru; Morofuji, Yoichi; Hayashi, Kentaro; Izumo, Tsuyoshi; Tsujino, Akira; Nagata, Izumi; Matsuo, Takayuki

2016-10-01

Acute ischemic stroke with major intracranial vessel occlusion is commonly due to cardioembolic or atherosclerosis-related in situ stenosis/occlusion, and immediate identification of these subtypes is important to establish the optimal treatment strategy. The aim of this study was to clarify the differences in clinical presentation, radiological findings, neurological temporal courses, and outcomes between these etiologies, which have not been fully evaluated. Consecutive emergency patients with acute ischemic stroke were retrospectively reviewed. Among them, patients with stroke with major intracranial vessel occlusion were analyzed with a focus on clinical and radiological findings, and a comparison was performed for those with cardioembolic or atherosclerosis-related in situ stenosis/occlusion. Of 1053 patients, 80 had stroke with acute major intracranial vessel occlusion (45 with cardioembolic and 35 with atherosclerosis-related in situ stenosis/occlusion). Interestingly, the susceptibility vessel sign (SVS) on T2-weighted MR angiography was more frequently detected in cardioembolic stroke (80.0%) than in atherosclerosis (in situ stenosis: 5.9%, chronic occlusion: 14.3%). Moreover, the proximal intra-arterial signal (IAS) on arterial spin labeling MRI and the distal IAS on fluid attenuated inversion recovery MRI was less frequently detected in chronic occlusion (27.3% and 50.0%, respectively) than in acute occlusion due to cardioembolic or in situ stenosis. Multivariate regression analysis showed that the SVS was significantly related to cardioembolism (adjusted odds ratio (OR): 21.68, P=0.004). Clinical characteristics of acute stroke with major intracranial vessel occlusion differ depending on the etiology. The SVS and proximal/distal IAS on MRI are useful to distinguish between cardioembolic and atherosclerotic-related in situ stenosis/occlusion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Focal epidural cooling reduces the infarction volume of permanent middle cerebral artery occlusion in swine.

PubMed

Zhang, Lihua; Cheng, Huilin; Shi, Jixin; Chen, Jun

2007-02-01

The protective effect against ischemic stroke by systemic hypothermia is limited by the cooling rate and it has severe complications. This study was designed to evaluate the effect of SBH induced by epidural cooling on infarction volume in a swine model of PMCAO. Permanent middle cerebral artery occlusion was performed in 12 domestic swine assigned to groups A and B. In group A, the cranial and rectal temperatures were maintained at normal range (37 degrees C-39 degrees C) for 6 hours after PMCAO. In group B, cranial temperature was reduced to moderate (deep brain, <30 degrees C) and deep (brain surface, <20 degrees C) temperature and maintained at that level for 5 hours after 1 hour after PMCAO, by the epidural cooling method. All animals were euthanized 6 hours after MCAO; their brains were sectioned and stained with 2,3,5-triphenyltetrazolium chloride and their infarct volumes were calculated. The moderate and deep brain temperature (at deep brain and brain surface) can be induced by rapid epidural cooling, whereas the rectal temperature was maintained within normal range. The infarction volume after PMCAO was significantly reduced by epidural cooling compared with controls (13.73% +/- 1.82% vs 5.62% +/- 2.57%, P < .05). The present study has demonstrated, with histologic confirmation, that epidural cooling may be a useful strategy for reducing infarct volume after the onset of ischemia.

Recurrence of amblyopia after occlusion therapy.

PubMed

Bhola, Rahul; Keech, Ronald V; Kutschke, Pamela; Pfeifer, Wanda; Scott, William E

2006-11-01

To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. Retrospective, population-based, consecutive observational case series. Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)-level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as > or =2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age (P<0.0001).

Melatonin improves neuroplasticity by upregulating the growth-associated protein-43 (GAP-43) and NMDAR postsynaptic density-95 (PSD-95) proteins in cultured neurons exposed to glutamate excitotoxicity and in rats subjected to transient focal cerebral ischemia even during a long-term recovery period.

PubMed

Juan, Wei-Sheng; Huang, Sheng-Yang; Chang, Che-Chao; Hung, Yu-Chang; Lin, Yu-Wen; Chen, Tsung-Ying; Lee, Ai-Hua; Lee, Ai-Chiang; Wu, Tian-Shung; Lee, E-Jian

2014-03-01

Recent evidence shows that the NMDAR postsynaptic density-95 (PSD-95), growth-associated protein-43 (GAP-43), and matrix metalloproteinase-9 (MMP-9) protein enhance neuroplasticity at the subacute stage of stroke. Here, we evaluated whether melatonin would modulate the PSD-95, GAP-43, and MMP-9 proteins in cultured neurons exposed to glutamate excitotoxicity and in rats subjected to experimental stroke. Adult male Sprague-Dawley rats were treated with melatonin (5 mg/kg) or vehicle at reperfusion onset after transient occlusion of the right middle cerebral artery (tMCAO) for 90 min. Animals were euthanized for Western immunoblot analyses for the PSD-95 and GAP-43 proteins and gelatin zymography for the MMP-9 activity at 7 days postinsult. Another set of animals was sacrificed for histologic and Golgi-Cox-impregnated sections at 28 days postinsult. In cultured neurons exposed to glutamate excitotoxicity, melatonin significantly upregulated the GAP-43 and PSD-95 expressions and improved dendritic aborizations (P<0.05, respectively). Relative to controls, melatonin-treated stroke animals caused a significant improvement in GAP-43 and PSD-95 expressions as well as the MMP-9 activity in the ischemic brain (P<0.05). Consequently, melatonin also significantly promoted the dendritic spine density and reduced infarction in the ischemic brain, and improved neurobehaviors as well at 28 days postinsult (P<0.05, respectively). Together, melatonin upregulates GAP-43, PSD-95, and MMP-9 proteins, which likely accounts for its actions to improve neuroplasticity in cultured neurons exposed to glutamate excitotoxicity and to enhance long-term neuroprotection, neuroplasticity, and brain remodeling in stroke rats. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Neuropilin 2 deficiency does not affect cortical neuronal viability in response to oxygen-glucose-deprivation and transient middle cerebral artery occlusion.

PubMed

Hou, Sheng T; Jiang, Susan X; Slinn, Jacqueline; O'Hare, Michael; Karchewski, Laurie

2010-04-01

Neuropilin 2 (NRP2) is a type I transmembrane protein that binds to distinct members of the class III secreted Semaphorin subfamily. NRP2 plays important roles in repulsive axon guidance, angiogenesis and vasculogenesis through partnering with co-receptors such as vascular endothelial growth factor receptors (VEGFRs) during development. Emerging evidence also suggests that NRP2 contributes to injury response and environment changes in adult brains. In this study, we examined the contribution of NRP2 gene to cerebral ischemia-induced brain injury using NRP2 deficient mouse. To our surprise, the lack of NRP2 expression does not affect the outcome of brain injury induced by transient occlusion of the middle cerebral artery (MCAO) in mouse. The cerebral vasculature in terms of the middle cerebral artery anatomy and microvessel density in the cerebral cortex of NRP2 deficient homozygous (NRP2(-/-)) mice are normal and almost identical to those of the heterozygous (NRP2(+/-)) and wild type (NRP2(+/+)) littermates. MCAO (1h) and 24h reperfusion caused a brain infarction of 23% (compared to the contralateral side) in NRP2(-/-) mice, which is not different from those in NRP2(+/- and +/+) mice at 22 and 21%, respectively (n=19, p>0.05). Correspondingly, NRP2(-/-) mouse also showed a similar level of deterioration of neurological functions after stroke compared with their NRP2(+/- and +/+) littermates. Oxygen-glucose-deprivation (OGD) caused a significant neuronal death in NRP2(-/-) cortical neurons, at the level similar to that in NRP(+/+) cortical neurons (72% death in NRP(-/-) neurons vs. 75% death in NRP2(+/+) neurons; n=4; p>0.05). Together, these loss-of-function studies demonstrated that despite of its critical role in neuronal guidance and vascular formation during development, NRP2 expression dose not affect adult brain response to cerebral ischemia. Crown Copyright 2009. Published by Elsevier Ireland Ltd. All rights reserved.

Estradiol and Progesterone Administration After pMCAO Stimulates the Neurological Recovery and Reduces the Detrimental Effect of Ischemia Mainly in Hippocampus.

PubMed

Perez-Alvarez, Maria Jose; Mateos, Laura; Alonso, Alvaro; Wandosell, Francisco

2015-12-01

Epidemiological studies have suggested a differential response, males versus female, in stroke incidence and prognosis. These divergences in brain response after damage are based mostly on hormonal differences. To date, estradiol and progesterone administered independently have demonstrated neuroprotection after ischemia in animal models. Nonetheless, contradictory results were revealed using a combined administration. In order to evaluate the effects of combinatorial treatment administered after ischemia induction, we used two different approaches: in vivo and in vitro models. Male rats which underwent permanent middle cerebral artery occlusion were treated with a combination of estradiol/progesterone at 6, 24 and 48 h after injury and sacrificed at 54 h post-ischemia. The rat brains were evaluated for reactive gliosis, NeuN-positive neurons, levels of synapse-associated proteins and activity levels of PI3K/Akt/GSK3/β-catenin survival pathway. Also, primary cortical neurons were subjected to oxygen and glucose deprivation for 17 h and returned to a normal environment in the presence of estradiol or estradiol/progesterone. Cell viability was evaluated, and activity levels of the PI3K/Akt/GSK3/β-catenin pathway. Our results indicate that some beneficial effects of estradiol were abolished in the presence of progesterone, particularly in the cerebral cortex (core). However, the combinatorial treatment showed positive effects in the hippocampus.

[Temporomandibular joint, occlusion and bruxism].

PubMed

Orthlieb, J D; Ré, J P; Jeany, M; Giraudeau, A

2016-09-01

Temporomandibular joint and dental occlusion are joined for better and worse. TMJ has its own weaknesses, sometimes indicated by bad functional habits and occlusal disorders. Occlusal analysis needs to be addressed simply and clearly. The term "malocclusion" is not reliable to build epidemiological studies, etiologic mechanisms or therapeutic advice on this "diagnosis". Understanding the impact of pathogenic malocclusion is not just about occlusal relationships that are more or less defective, it requires to locate them within the skeletal framework, the articular and behavioural context of the patient, and above all to assess their impact on the functions of the masticatory system. The TMJ-occlusion couple is often symbiotic, developing together in relation to its environment, compensating for its own shortcomings. However, a third partner may alter this relationship, such as bruxism, or more generally oral parafunctions, trauma or an interventionist practitioner. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A comparison of different models of stroke on behaviour and brain morphology.

PubMed

Gonzalez, C L R; Kolb, B

2003-10-01

We compared the effects of three models of permanent ischemia, as well as cortical aspiration, on behaviour and brain morphology. Rats received a stroke either by devascularization or by two different procedures of medial cerebral artery occlusion (MCAO; small vs. large). Animals were trained in a reaching task, forepaw asymmetry, forepaw inhibition, sunflower seed task and tongue extension. Behaviour was assessed 1 week after the lesion and at 2-week intervals for a total of 9 weeks. One week after the surgery all animals were severely impaired on all tasks and although they improved over time they only reached preoperative base lines on tongue extension. Animals with small MCAOs performed better in reaching and sunflower tasks; no other behavioural differences were detected among the groups. Pyramidal cells in forelimb and cingulate areas as well as spiny neurons of the striatum were examined for dendritic branching and spine density using a Golgi-Cox procedure. Each lesion type had a different impact on cell morphology. Overall, different changes (atrophy or hypertrophy) were observed with each kind of lesion and these changes were specific for the region (forelimb, cingulate, striatum) and the condition (intact vs. damaged hemisphere). These results suggest that: (i) different lesions to the motor cortex produce subtle differences in behaviour, and (ii) the method used to induce the lesion produces striking differences in cortical and subcortical plasticity.

Docosahexaenoic acid confers enduring neuroprotection in experimental stroke.

PubMed

Hong, Sung-Ha; Belayev, Ludmila; Khoutorova, Larissa; Obenaus, Andre; Bazan, Nicolas G

2014-03-15

Recently we demonstrated that docosahexaenoic acid (DHA) is highly neuroprotective when animals were allowed to survive during one week. This study was conducted to establish whether the neuroprotection induced by DHA persists with chronic survival. Sprague-Dawley rats underwent 2h of middle cerebral artery occlusion (MCAo) and treated with DHA or saline at 3h after MCAo. Animals received neurobehavioral examination (composite neuroscore, rota-rod, beam walking and Y maze tests) followed by ex vivo magnetic resonance imaging and histopathology at 3 weeks. DHA improved composite neurologic score beginning on day 1 by 20%, which persisted throughout weeks 1-3 by 24-41% compared to the saline-treated group. DHA prolonged the latency in rota-rod on weeks 2-3 by 162-178%, enhanced balance performance in the beam walking test on weeks 1 and 2 by 42-51%, and decreased the number of entries in the Y maze test by 51% and spontaneous alteration by 53% on week 2 compared to the saline-treated group. DHA treatment reduced tissue loss (computed from T2-weighted images) by 24% and total and cortical infarct volumes by 46% and 54% compared to the saline-treated group. These results show that DHA confers enduring ischemic neuroprotection. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Regulation of body temperature and neuroprotection by endogenous interleukin-6 in cerebral ischemia.

PubMed

Herrmann, Oliver; Tarabin, Victoria; Suzuki, Shigeaki; Attigah, Nicolas; Coserea, Irinel; Schneider, Armin; Vogel, Johannes; Prinz, Simone; Schwab, Stefan; Monyer, Hannah; Brombacher, Frank; Schwaninger, Markus

2003-04-01

Although the function of fever is still unclear, it is now beyond doubt that body temperature influences the outcome of brain damage. An elevated body temperature is often found in stroke patients and denotes a bad prognosis. However, the pathophysiologic basis and treatment options of elevated body temperature after stroke are still unknown. Cerebral ischemia rapidly induced neuronal interleukin-6 (IL-6) expression in mice. In IL-6-deficient mice, body temperature was markedly decreased after middle cerebral artery occlusion (MCAO), but infarct size was comparable to that in control mice. If body temperature was controlled by external warming after MCAO, IL-6-deficient mice had a reduced survival, worse neurologic status, and larger infarcts than control animals. In cell culture, IL-6 exerted an antiapoptotic and neuroprotective effect. These data suggest that IL-6 is a key regulator of body temperature and an endogenous neuroprotectant in cerebral ischemia. Neuroprotective properties apparently compensate for its pyretic action after MCAO and enhance the safety of this endogenous pyrogen.

Magnetic resonance lactate and lipid signals in rat brain after middle cerebral artery occlusion model

PubMed Central

Harada, Kuniaki; Honmou, Osamu; Liu, He; Bando, Michio; Houkin, Kiyohiro; Kocsis, Jeffery D.

2008-01-01

Proton magnetic resonance spectroscopy (1-H MRS) has revealed changes of metabolites in acute cerebral infarction. Although the drastic changes of lactate and N-acetyl-aspartate have been reported to be useful indicators of the ischemic damage in both humans and experimental animals, lipid signals are also detected by the short echo time sequence 1–5 days after ischemia. The objective of this study was to find a novel technique to isolate lactate signals from lipid signals in the ischemic brain. First, MRS was used to study the lipid and lactate components of a spherical phantom in vitro, and parameters were established to separate these components in vitro. Then, MR measurements were obtained from the brains of middle cerebral artery occlusion rats. All MR measurements were performed using a 7-T (300 MHz), 18.3-cm-bore superconducting magnet (Oxford Magnet Technologies) interfaced to a Unity INOVA Imaging System (Varian Technologies). T2-weighted images were obtained from a 1.0-mm-thick coronal section using a 3-cm field of view. It is well known that lipid has a shorter and lactate a longer T2 relaxation time. These distinct magnetic characteristics allowed us to separate the lactate signal from the lipid signal. Thus, adjustment of the echo time is essential to analyze the metabolites in acute cerebral infarction, which may be useful in both the clinic and laboratory. PMID:17196558

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

PubMed

Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Sulforaphane preconditioning of the Nrf2/HO-1 defense pathway protects the cerebral vasculature against blood-brain barrier disruption and neurological deficits in stroke.

PubMed

Alfieri, Alessio; Srivastava, Salil; Siow, Richard C M; Cash, Diana; Modo, Michel; Duchen, Michael R; Fraser, Paul A; Williams, Steven C R; Mann, Giovanni E

2013-12-01

Disruption of the blood-brain barrier (BBB) and cerebral edema are the major pathogenic mechanisms leading to neurological dysfunction and death after ischemic stroke. The brain protects itself against infarction via activation of endogenous antioxidant defense mechanisms, and we here report the first evidence that sulforaphane-mediated preactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1) in the cerebral vasculature protects the brain against stroke. To induce ischemic stroke, Sprague-Dawley rats were subjected to 70 min middle cerebral artery occlusion (MCAo) followed by 4, 24, or 72 h reperfusion. Nrf2 and HO-1 protein expression was upregulated in cerebral microvessels of peri-infarct regions after 4-72 h, with HO-1 preferentially associated with perivascular astrocytes rather than the cerebrovascular endothelium. In naïve rats, treatment with sulforaphane increased Nrf2 expression in cerebral microvessels after 24h. Upregulation of Nrf2 by sulforaphane treatment prior to transient MCAo (1h) was associated with increased HO-1 expression in perivascular astrocytes in peri-infarct regions and cerebral endothelium in the infarct core. BBB disruption, lesion progression, as analyzed by MRI, and neurological deficits were reduced by sulforaphane pretreatment. As sulforaphane pretreatment led to a moderate increase in peroxynitrite generation, we suggest that hormetic preconditioning underlies sulforaphane-mediated protection against stroke. In conclusion, we propose that pharmacological or dietary interventions aimed to precondition the brain via activation of the Nrf2 defense pathway in the cerebral microvasculature provide a novel therapeutic approach for preventing BBB breakdown and neurological dysfunction in stroke. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

P2X7 receptor inhibition increases CNTF in the subventricular zone, but not neurogenesis or neuroprotection after stroke in adult mice.

PubMed

Kang, Seong Su; Keasey, Matthew Phillip; Hagg, Theo

2013-10-01

Increasing endogenous ciliary neurotrophic factor (CNTF) expression with a pharmacological agent might be beneficial after stroke as CNTF both promotes neurogenesis and, separately, is neuroprotective. P2X7 purinergic receptor inhibition is neuroprotective in rats and increases CNTF release in rat CMT1A Schwann cells. We, first, investigated the role of P2X7 in regulating CNTF and neurogenesis in adult mouse subventricular zone (SVZ). CNTF expression was increased by daily intravenous injections of the P2X7 antagonist Brilliant Blue G (BBG) in naïve C57BL/6 or Balb/c mice over 3 days. Despite the ∼40-60 % increase or decrease in CNTF with BBG or the agonist BzATP, respectively, the number of proliferated BrdU+SVZ nuclei did not change. BBG failed to increase FGF2, which is involved in CNTF-regulated neurogenesis, but induced IL-6, LIF, and EGF, which are known to reduce SVZ proliferation. Injections of IL-6 next to the SVZ induced CNTF and FGF2, but not proliferation, suggesting that IL-6 counteracts their neurogenesis-inducing effects. Following ischemic injury of the striatum by middle cerebral artery occlusion (MCAO), a 3-day BBG treatment increased CNTF in the medial penumbra containing the SVZ. BBG also induced CNTF and LIF, which are known to be protective following stroke, in the whole striatum after MCAO, but not GDNF or BDNF. However, BBG treatment did not reduce the lesion area or apoptosis in the penumbra. Even so, this study shows that P2X7 can be targeted with systemic drug treatments to differentially regulate neurotrophic factors in the brain following stroke.

P43/pro-EMAPII: A Potential Biomarker for Discriminating Traumatic Versus Ischemic Brain Injury

PubMed Central

Yao, Changping; Williams, Anthony J.; Ottens, Andrew K.; Lu, X.-C. May; Liu, Ming Cheng; Hayes, Ronald L.; Wang, Kevin K.; Tortella, Frank C.

2009-01-01

Abstract To gain additional insights into the pathogenic cellular and molecular mechanisms underlying different types of brain injury (e.g., trauma versus ischemia), recently attention has focused on the discovery and study of protein biomarkers. In previous studies, using a high-throughput immunoblotting (HTPI) technique, we reported changes in 29 out of 998 proteins following acute injuries to the rat brain (penetrating traumatic versus focal ischemic). Importantly, we discovered that one protein, endothelial monocyte-activating polypeptide II precursor (p43/pro-EMAPII), was differentially expressed between these two types of brain injury. Among other functions, p43/pro-EMAPII is a known pro-inflammatory cytokine involved in the progression of apoptotic cell death. Our current objective was to verify the changes in p43/pro-EMAPII expression, and to evaluate the potentially important implications that the differential regulation of this protein has on injury development. At multiple time points following either a penetrating ballistic-like brain injury (PBBI), or a transient middle cerebral artery occlusion (MCAo) brain injury, tissue samples (6–72 h), CSF samples (24 h), and blood samples (24 h) were collected from rats for analysis. Changes in protein expression were assessed by Western blot analysis and immunohistochemistry. Our results indicated that p43/pro-EMAPII was significantly increased in brain tissues, CSF, and plasma following PBBI, but decreased after MCAo injury compared to their respective sham control samples. This differential expression of p43/pro-EMAPII may be a useful injury-specific biomarker associated with the underlying pathologies of traumatic versus ischemic brain injury, and provide valuable information for directing injury-specific therapeutics. PMID:19317603

Using OCT-based microangiography for in vivo longitudinal study of arteriogenesis (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Yuandong; Choi, Woo June; Wang, Ruikang K.

2017-03-01

The adaptive growth of collateral vessels, termed "arteriogenesis", is crucial for maintaining regional blood supply during arterial obstruction and offsetting the adverse effect of tissue ischemia. Stimulation of arteriogenesis has been applied for the treatment of occlusive vascular diseases, and in vivo imaging of the progressive development of collateral vessel will facilitate a better understanding of the mechanism. We present using high-resolution OCT-based microangiography (OMAG) to image arteriogenesis process longitudinally in mouse cerebral cortex after middle cerebral artery occlusion (MCAO). We imaged the collateral arterioles at the arteriolo-arteriolar anastomosis (AAA) within 7-day period after MCAO to reveal key elements of collateral vessel remodeling, including alteration in vessel morphology, velocity and directionality of blood flow. The magnitudes of changes in these parameters matched the time course of the active building of collateral vessels stated in previous studies using histology. Hence, OMAG is a promising imaging tool for non-invasive longitudinal study of functional collateral vessel growth in small animal models and can be potentially applied in the experimental study of arteriogenesis stimulation.

The antioxidant and antiapoptotic effects of crocin pretreatment on global cerebral ischemia reperfusion injury induced by four vessels occlusion in rats.

PubMed

Oruc, Serdar; Gönül, Yücel; Tunay, Kamil; Oruc, Oya Akpinar; Bozkurt, Mehmet Fatih; Karavelioğlu, Ergün; Bağcıoğlu, Erman; Coşkun, Kerem Senol; Celik, Sefa

2016-06-01

Cerebral ischemia reperfusion (IR) injury is a process in which oxidative and apoptotic mechanisms play a part. Neuroprotective agents to be found could work out well for the efficient and safe minimization of cerebral IR injury. Crocin is a strong antioxidant agent; however the influence of this agent on the experimental cerebral ischemia model has not been studied extensively and thus it is not well-known. The objective of our study was to investigate the antioxidant, antiapoptotic and protective effects of crocin on the global cerebral IR induced by four-vessel occlusion. A total of 30 adult female Sprague-Dawley rats were equally and randomly separated into three groups as follows: sham, IR and IR+crocin (40mg/kg/day orally for 10days). 24h after electrocauterization of bilateral vertebral arteries, bilateral common carotid arteries were occluded for 30min and reperfused for 30min. Oxidative stress parameters (TAS, TOS, OSI), haematoxylin and eosin staining, caspase-3 and hypoxia-inducible factor-1 alpha (HIF-1α) expressions and TUNEL methods were investigated. There was a significant difference between the IR and sham groups by means of OSI level, histopathological scoring, caspase-3, HIF-1α and TUNEL-positive cell parameters. We have also observed that pre-treatment with crocin reduced these parameter levels back to the baseline. The data obtained from the present study suggest that crocin may exert antiapoptotic, antioxidant and protective effects in IR-mediated brain injury induced by four-vessel occlusion. To the best of our knowledge, this would be the first study to be conducted in this field. Copyright © 2016 Elsevier Inc. All rights reserved.

Overexpression of Human S100B Exacerbates Brain Damage and Periinfarct Gliosis After Permanent Focal Ischemia

PubMed Central

Mori, Takashi; Tan, Jun; Arendash, Gary W.; Koyama, Naoki; Nojima, Yoshiko; Town, Terrence

2009-01-01

Background and Purpose We have previously demonstrated that augmented and prolonged activation of astrocytes detrimentally influences both the subacute and chronic phases of cerebral ischemia. Furthermore, we have suggested that the astrocyte-derived protein S100B may be important in these pathogenic events. However, the causal relationship between S100B and exacerbation of brain damage in vivo remains to be elucidated. Methods Using transgenic mice overexpressing human S100B (Tg huS100B mice), we examined whether S100B plays a cardinal role in aggravation of brain damage after permanent middle cerebral artery occlusion (pMCAO). Results Tg huS100B mice had significantly larger infarct volumes and worse neurological deficits at any time point examined after pMCAO as compared with CD-1 background strain-matched control mice. Infarct volumes in Tg huS100B mice were significantly increased from 1 to 3 and 5 days after pMCAO (delayed infarct expansion), whereas those in control mice were not significantly altered. S100, glial fibrillary acidic protein, and Iba1 burdens in the periinfarct area were significantly increased through to 7 days after pMCAO in Tg huS100B mice, whereas those in control mice reached a plateau at 3 days after pMCAO. Conclusions These results provide genetic evidence that overexpression of human S100B acts to exacerbate brain damage and periinfarct reactive gliosis (astrocytosis and microgliosis) during the subacute phase of pMCAO. PMID:18451356

In vivo imaging of brain infarct with the novel fluorescent probe PSVue 794 in a rat middle cerebral artery occlusion-reperfusion model.

PubMed

Chu, Chun; Huang, Xiaofang; Chen, Chiung-Tong; Zhao, Yuanli; Luo, Jin J; Gray, Brian D; Pak, Koon Y; Dun, Nae J

2013-01-01

The utility of PSVue 794 (PS794), a near-infrared fluorescent dye conjugated to a bis[zinc (II)-dipicolylamine] (Zn-DPA) targeting moiety, in imaging brain infarct was assessed in a rat middle cerebral artery occlusion-reperfusion model. Following reperfusion, 1 mM PS794 solution was administered intravenously via a tail vein. Fluorescence images were captured between 6 to 72 hours postinjection using a LI-COR Biosciences Pearl Imaging System. Strong fluorescence signals, which may represent the infarct core, were detected in the right hemisphere, ipsilateral to the injured site, and weaker signals in areas surrounding the core. In ischemia-reperfusion rats injected with a control dye not linked to a targeting agent, fluorescence was distributed diffusely throughout the brain. To address the issue of whether Zn-DPA targets apoptotic/necrotic cells, HT22 mouse hippocampal neurons were cultured in either Dulbecco's Modified Eagle's Medium, serum-deprived medium, Hank's Balanced Salt Solution, or L-glutamate (10 mM)-containing medium for up to 33 hours. Cells were then double-labeled with PSVue 480 (Zn-DPA conjugated to fluorescein isothiocyanate) and propidium iodide, which labels necrotic cells. Microscopic examination revealed that PS480 targeted apoptotic and necrotic cells. The result indicates that PS794 is applicable to in vivo imaging of brain infarct and that Zn-DPA selectively targets apoptotic/necrotic cells.

Chronic photoperiod disruption does not increase vulnerability to focal cerebral ischemia in young normotensive rats.

PubMed

Ku Mohd Noor, Ku Mastura; Wyse, Cathy; Roy, Lisa A; Biello, Stephany M; McCabe, Christopher; Dewar, Deborah

2017-11-01

Photoperiod disruption, which occurs during shift work, is associated with changes in metabolism or physiology (e.g. hypertension and hyperglycaemia) that have the potential to adversely affect stroke outcome. We sought to investigate if photoperiod disruption affects vulnerability to stroke by determining the impact of photoperiod disruption on infarct size following permanent middle cerebral artery occlusion. Adult male Wistar rats (210-290 g) were housed singly under two different light/dark cycle conditions ( n = 12 each). Controls were maintained on a standard 12:12 light/dark cycle for nine weeks. For rats exposed to photoperiod disruption, every three days for nine weeks, the lights were switched on 6 h earlier than in the previous photoperiod. T 2 -weighted magnetic resonance imaging was performed at 48 h after middle cerebral artery occlusion. Disruption of photoperiod in young healthy rats for nine weeks did not alter key physiological variables that can impact on ischaemic damage, e.g. blood pressure and blood glucose immediately prior to middle cerebral artery occlusion. There was no effect of photoperiod disruption on infarct size after middle cerebral artery occlusion. We conclude that any potentially adverse effect of photoperiod disruption on stroke outcome may require additional factors such as high fat/high sugar diet or pre-existing co-morbidities.

By improving regional cortical blood flow, attenuating mitochondrial dysfunction and sequential apoptosis galangin acts as a potential neuroprotective agent after acute ischemic stroke.

PubMed

Li, Shaojing; Wu, Chuanhong; Zhu, Li; Gao, Jian; Fang, Jing; Li, Defeng; Fu, Meihong; Liang, Rixin; Wang, Lan; Cheng, Ming; Yang, Hongjun

2012-11-09

Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxidant agent. However, its effects against ischemic stroke have not been reported and its related neuroprotective mechanism has not really been explored. In this study, neurological behavior, cerebral infarct volumes and the improvement of the regional cortical blood flow (rCBF) were used to evaluate the therapeutic effect of galangin in rats impaired by middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia. Furthermore, the determination of mitochondrial function and Western blot of apoptosis-related proteins were performed to interpret the neuroprotective mechanism of galangin. The results showed that galangin alleviated the neurologic impairments, reduced cerebral infarct at 24 h after MCAO and exerted a protective effect on the mitochondria with decreased production of mitochondrial reactive oxygen species (ROS). These effects were consistent with improvements in the membrane potential level (Dym), membrane fluidity, and degree of mitochondrial swelling in a dose-dependent manner. Moreover, galangin significantly improved the reduced rCBF after MCAO. Western blot analysis revealed that galangin also inhibited apoptosis in a dose-dependent manner concomitant with the up-regulation of Bcl-2 expression, down-regulation of Bax expression and the Bax/Bcl-2 ratio, a reduction in cytochrome c release from the mitochondria to the cytosol, the reduced expression of activated caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). All these data in this study demonstrated that galangin might have therapeutic potential for ischemic stroke and play its protective role through the improvement in rCBF, mitochondrial protection and inhibiting caspase-dependent mitochondrial cell death pathway for the first time.

Attenuation of reperfusion-induced hepatocyte apoptosis is associated with reversed bcl-2/bax ratio in hemi-hepatic artery-preserved portal occlusion.

PubMed

Jin, Shan; Dai, Chao-Liu

2012-05-15

This study aimed to examine the hepatocyte apoptosis in a hepatic blood inflow occlusion rat model without hemi-hepatic arterial control and its association with the expressions of the apoptosis-regulating genes bcl-2 and bax. Wistar rats were equally and randomly assigned to undergo sham operation (control group, n = 8), Pringle's maneuver (group PR, n = 32), hemi-hepatic occlusion (group HH, n = 32), or hemi-hepatic artery-preserved portal occlusion (group HP, n = 32). The hepatic blood inflow was interrupted for 30 min using a microvascular clip in the three experimental groups. The clips were removed to achieve hepatic reperfusion for up to 24 h. Blood samples and liver specimens were collected following reperfusion to perform pathologic examination, serum transferase assay, apoptosis analysis, and determination of bcl-2 and bax mRNA and protein expressions. The reperfusion-related hepatocytic injuries were more severe in the PR group than in the HH and HP groups, both pathologically and biochemically. More reperfused hepatocytes became apoptotic in the PR group than in the HH and HP groups. However, the values of the HH and HP groups were comparable in cellularity, levels of serum transferases, and apoptosis rate following reperfusion. The ratios of bcl-2/bax were reversed, which was more evident in the HH and HP groups than in the PR group. Hemi-hepatic artery-preserved portal occlusion had little effect on hepatocyte apoptosis compared with Pringle's maneuver and caused minor ischemia-reperfusion injury as shown by the reversed bcl-2/bax ratio. Copyright © 2012 Elsevier Inc. All rights reserved.

Therapeutic effects of oral dimethyl fumarate on stroke induced by middle cerebral artery occlusion: An animal experimental study.

PubMed

Safari, Anahid; Fazeli, Mehdi; Namavar, Mohammad Reza; Tanideh, Nader; Jafari, Peyman; Borhani-Haghighi, Afshin

2017-01-01

Dimethyl fumarate (DMF) has immune-modulatory and neuro-protective characteristics that can be used for treatment of acute ischemic stroke. To investigate the therapeutic effects of DMF on histological and functional recovery of rats after transient middle cerebral artery (MCA) occlusion. 22 Sprague-Dawley male rats weighing 275-300 g were randomized into three groups by block randomization. In the sham group (n = 7), the neck was opened, but neither MCA was occluded, nor any drug was administered.The control group (n = 7) was treated with vehicle (methocel) by gavage for 14 days after MCA occlusion. In the DMF-treated group (n = 8), treatment was performed with 15 mg/kg body weight dimethyl fumarate twice a day for 14 days after MCA occlusion. Transient occlusion of the right MCA was performed by intraluminal thread method in the DMF-treated and the control group. Neurological deficit score (NDS), pole test, and adhesive removal test were performed before the surgery, and on post-operative Days 0, 3, 5, 7, 10, and 14. After the final behaviour test, the animals' brains were perfused and removed. Brains were frozen and sectioned serially and coronally using a cryostat. Infract volume and brain volume were estimated by stereology. The percentage of infarct volume was significantly lower in DMF-treated animals (5.76%) than in the control group (22.39%) (P < 0.0001). Regarding behavioural tests, the DMF-treated group showed better function in NDS on Days 7 (P = 0.041) and 10 (P = 0.046), but not in pole and adhesive removal tests. There was no significant correlation between behavioural tests and histological results. Dimethyl fumarate could be beneficial as a potential neuroprotective agent in the treatment of stroke.

The Akt/GSK-3β pathway mediates flurbiprofen-induced neuroprotection against focal cerebral ischemia/reperfusion injury in rats.

PubMed

Sun, Baozhu; Chen, Lin; Wei, Xinbing; Xiang, Yanxiao; Liu, Xiaoqian; Zhang, Xiumei

2011-06-17

Apoptosis is one of the major mechanisms of cell death during cerebral ischemia and reperfusion injury. Flurbiprofen has been shown to reduce cerebral ischemia/reperfusion injury in both focal and global cerebral ischemia models, but the mechanism remains unclear. This study aimed to investigate the potential association between the neuroprotective effect of flurbiprofen and the apoptosis inhibiting signaling pathways, in particularly the Akt/GSK-3β pathway. A focal cerebral ischemia rat model was subjected to middle cerebral artery occlusion (MCAO) for 120 min and then treated with flurbiprofen at the onset of reperfusion. The infarct volume and the neurological deficit scores were evaluated at 24h after reperfusion. Cell apoptosis, apoptosis-related proteins and the levels of p-Akt and p-GSK-3β in ischemic penumbra were measured using TUNEL and western blot. The results showed that administration of flurbiprofen at the doses of 5 and 10mg/kg significantly attenuated brain ischemia/reperfusion injury, as shown by a reduction in the infarct volume, neurological deficit scores and cell apoptosis. Moreover, flurbiprofen not only inhibited the expression of Bax protein and p-GSK-3β, but also increased the expression of Bcl-2 protein, the ratio of Bcl-2/Bax as well as the P-Akt level. Taken together, these results suggest that flurbiprofen protects the brain from ischemia/reperfusion injury by reducing apoptosis and this neuroprotective effect may be partly due to the activation of Akt/GSK-3β signaling pathway. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Low-energy shock wave preconditioning reduces renal ischemic reperfusion injury caused by renal artery occlusion.

PubMed

Xue, Yuquan; Xu, Zhibin; Chen, Haiwen; Gan, Weimin; Chong, Tie

2017-07-01

To evaluate whether low energy shock wave preconditioning could reduce renal ischemic reperfusion injury caused by renal artery occlusion. The right kidneys of 64 male Sprague Dawley rats were removed to establish an isolated kidney model. The rats were then divided into four treatment groups: Group 1 was the sham treatment group; Group 2, received only low-energy (12 kv, 1 Hz, 200 times) shock wave preconditioning; Group 3 received the same low-energy shock wave preconditioning as Group 2, and then the left renal artery was occluded for 45 minutes; and Group 4 had the left renal artery occluded for 45 minutes. At 24 hours and one-week time points after reperfusion, serum inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), creatinine (Cr), and cystatin C (Cys C) levels were measured, malondialdehyde (MDA) in kidney tissue was detected, and changes in nephric morphology were evaluated by light and electron microscopy. Twenty-four hours after reperfusion, serum iNOS, NGAL, Cr, Cys C, and MDA levels in Group 3 were significantly lower than those in Group 4; light and electron microscopy showed that the renal tissue injury in Group 3 was significantly lighter than that in Group 4. One week after reperfusion, serum NGAL, KIM-1, and Cys C levels in Group 3 were significantly lower than those in Group 4. Low-energy shock wave preconditioning can reduce renal ischemic reperfusion injury caused by renal artery occlusion in an isolated kidney rat model.

Influence of the fast-processing technique on the number of the occlusal contacts and occlusal vertical dimension of complete dentures.

PubMed

Atashrazm, Parsa; Alavijeh, Leila Zamani; Afshar, Maryam Sadat Sadrzadeh

2011-03-01

Occlusal errors during acryl processing affect the retention and stability of complete dentures. The aim of the present study was to assess the influence of a short curing technique on the number of occlusal contacts and the occlusal vertical dimension (OVD) of complete dentures. Complete dentures were prepared. The number of occlusal contacts was recorded in centric relation (CR) using 60 µ articulation paper. The OVD was recorded with the waxed trial denture in place. Dentures were then invested and processed with compression molding and short cure water bath technique. The number of occlusal contacts was recorded again. The amount of pin opening was measured for all of the complete dentures on the articulator. Data were analyzed with paired t-test to determine the alterations. The mean number of occlusal contacts before and after processing was 10.9 ± 2.4 and 6.3 ± 3.1 respectively (4.7 ± 1.9 decrease; p < 0.001). A 2 mm mean increase in OVD was observed in 47.7% of the dentures with < 6 occlusal contact changes and 88.9% of the dentures with ≥ 6 occlusal contact changes (p < 0.003). A significant change in the number of occlusal contacts was associated with an OVD increased up to two times. The short curing technique seems to be related to the decreased occlusal contacts and increased OVD. CLINICAL SIGNIFICANCES: More time is needed to adjust the occlusal errors of this method, because it has a negative effect on the morphologic pattern of artificial teeth of complete dentures and thus should be used carefully.

Ursolic Acid Ameliorates Inflammation in Cerebral Ischemia and Reperfusion Injury Possibly via High Mobility Group Box 1/Toll-Like Receptor 4/NFκB Pathway.

PubMed

Wang, Yanzhe; Li, Lei; Deng, Shumin; Liu, Fang; He, Zhiyi

2018-01-01

Toll-like receptors (TLRs) play key roles in cerebral ischemia and reperfusion injury by inducing the production of inflammatory mediators, such as interleukins (ILs) and tumor necrosis factor-alpha (TNF-α). According to recent studies, ursolic acid (UA) regulates TLR signaling and exhibits notable anti-inflammatory properties. In the present study, we explored the mechanism by which UA regulates inflammation in the rat middle cerebral artery occlusion and reperfusion (MCAO/R) model. The MCAO/R model was induced in male Sprague-Dawley rats (MCAO for 2 h, followed by reperfusion for 48 h). UA was administered intragastrically at 0.5, 24, and 47 h after reperfusion. The direct high mobility group box 1 (HMGB1) inhibitor glycyrrhizin (GL) was injected intravenously after 0.5 h of ischemia as a positive control. The degree of brain damage was estimated using the neurological deficit score, infarct volume, histopathological changes, and neuronal apoptosis. We assessed IL-1β, TNF-α, and IL-6 levels to evaluate post-ischemic inflammation. HMGB1 and TLR4 expression and phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) were also examined to explore the underlying mechanism. UA (10 and 20 mg/kg) treatment significantly decreased the neurological deficit scores, infarct volume, apoptotic cells, and IL-1β, TNF-α, and IL-6 concentrations. The infarct area ratio was reduced by (33.07 ± 1.74), (27.05 ± 1.13), (27.49 ± 1.87), and (39.74 ± 2.14)% in the 10 and 20 mg/kg UA, GL, and control groups, respectively. Furthermore, UA (10 and 20 mg/kg) treatment significantly decreased HMGB1 release and the TLR4 level and inactivated NFκB signaling. Thus, the effects of intragastric administration of 20 mg/kg of UA and 10 mg/kg of GL were similar. We provide novel evidence that UA reduces inflammatory cytokine production to protect the brain from cerebral ischemia and reperfusion injury possibly through the

Delayed treatment with ADAMTS13 ameliorates cerebral ischemic injury without hemorrhagic complication.

PubMed

Nakano, Takafumi; Irie, Keiichi; Hayakawa, Kazuhide; Sano, Kazunori; Nakamura, Yoshihiko; Tanaka, Masayoshi; Yamashita, Yuta; Satho, Tomomitsu; Fujioka, Masayuki; Muroi, Carl; Matsuo, Koichi; Ishikura, Hiroyasu; Futagami, Kojiro; Mishima, Kenichi

2015-10-22

Tissue plasminogen activator (tPA) is the only approved therapy for acute ischemic stroke. However, delayed tPA treatment increases the risk of cerebral hemorrhage and can result in exacerbation of nerve injury. ADAMTS13, a von Willebrand factor (VWF) cleaving protease, has a protective effect against ischemic brain injury and may reduce bleeding risk by cleaving VWF. We examined whether ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA in mice subjected to middle cerebral artery occlusion (MCAO). ADAMTS13 (0.1mg/kg) or tPA (10mg/kg) was administered i.v., immediately after reperfusion of after 2-h or 4-h MCAO for comparison of the therapeutic time windows in ischemic stroke. Infarct volume, hemorrhagic volume, plasma high-mobility group box1 (HMGB1) levels and cerebral blood flow were measured 24h after MCAO. Both ADAMTS13 and tPA improved the infarct volume without hemorrhagic complications in 2-h MCAO mice. On the other hand, ADAMTS13 reduced the infarct volume and plasma HMGB1 levels, and improved cerebral blood flow without hemorrhagic complications in 4-h MCAO mice, but tPA was not effective and these animals showed massive intracerebral hemorrhage. These results indicated that ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA, and ADAMTS13 may be useful as a new therapeutic agent for ischemic stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

Application of photogrammetry for analysis of occlusal contacts.

PubMed

Shigeta, Yuko; Hirabayashi, Rio; Ikawa, Tomoko; Kihara, Takuya; Ando, Eriko; Hirai, Shinya; Fukushima, Shunji; Ogawa, Takumi

2013-04-01

The conventional 2D-analysis methods for occlusal contacts provided limited information on tooth morphology. This present study aims to detect 3D positional information of occlusal contacts from 2D-photos via photogrammetry. We propose an image processing solution for analysis of occlusal contacts and facets via the black silicone method and a photogrammetric technique. The occlusal facets were reconstructed from a 2D-photograph data-set of inter-occlusal records into a 3D image via photogrammetry. The configuration of the occlusal surface was reproduced with polygons. In addition, the textures of the occlusal contacts were mapped to each polygon. DIFFERENCE FROM CONVENTIONAL METHODS: Constructing occlusal facets with 3D polygons from 2D-photos with photogrammetry was a defining characteristic of this image processing technique. It allowed us to better observe findings of the black silicone method. Compared with conventional 3D analysis using a 3D scanner, our 3D models did not reproduce the detail of the anatomical configuration. However, by merging the findings of the inter-occlusal record, the deformation of mandible and the displacement of periodontal ligaments under occlusal force were reflected in our model. EFFECT OR PERFORMANCE: Through the use of polygons in the conversion of 2D images to 3D images, we were able to define the relation between the location and direction of the occlusal contacts and facets, which was difficult to detect via conventional methods. Through our method of making a 3D polygon model, the findings of inter-occlusal records which reflected the jaw/teeth behavior under occlusal force could be observed 3-dimensionally. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Occlusal wear and occlusal condition in a convenience sample of young adults.

PubMed

Van't Spijker, A; Kreulen, C M; Bronkhorst, E M; Creugers, N H J

2015-01-01

To study progression of tooth wear quantitatively in a convenient sample of young adults and to assess possible correlations with occlusal conditions. Twenty-eight dental students participated in a three-year follow up study on tooth wear. Visible wear facets on full arch gypsum casts were assessed using a flatbed scanner and measuring software. Regression analyses were used to assess possible associations between the registered occlusal conditions 'occlusal guidance scheme', 'vertical overbite', 'horizontal overbite', 'depth of sagittal curve', 'canine Angle class relation', 'history of orthodontic treatment', and 'self-reported grinding/clenching' (independent variables) and increase of wear facets (dependent variable). Mean increase in facet surface areas ranged from 1.2 mm2 (premolars, incisors) to 3.4 mm2 (molars); the relative increase ranged from 15% to 23%. Backward regression analysis showed no significant relation for 'group function', 'vertical overbite', 'depth of sagittal curve', 'history of orthodontic treatment' nor 'self-reported clenching. The final multiple linear regression model showed significant associations amongst 'anterior protected articulation' and 'horizontal overbite' and increase of facet surface areas. For all teeth combined, only 'anterior protected articulation' had a significant effect. 'Self reported grinding' did not have a significant effect (p>0.07). In this study 'anterior protected articulation' and 'horizontal overbite', were significantly associated with the progression of tooth wear. Self reported grinding was not significantly associated with progression of tooth wear. Occlusal conditions such as anterior protected articulation and horizontal overbite seem to have an effect on the progression of occlusal tooth wear in this convenient sample of young adults. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Neuroprotective activity of the proline-containing dipeptide noopept on the model of brain ischemia induced by the middle cerebral artery occlusion].

PubMed

Gavrilova, S A; Us, K S; Ostrovskaia, R U; Koshelev, V B

2006-01-01

The influence of noopept (N-phenylacetyl-L-prolylglycine ethyl ester, GVS-111) on the extent of ischemic cortical stroke was investigated in experiments on white mongrel male rats with ischemia induced by a combination of the middle cerebral artery occlusion with ipsilateral common carotid artery ligation. Animals were treated with noopept (0.5 mg/kg, i.p.) according to the following schedule: 15 min and 2, 24, and 48 h after the occlusion. Test rats were decapitated 72 h after occlusion, brains were extracted and frozen, and thin brain slices were stained with 2,3,5-triphenyltetrazolium chloride. The slices were scanned and processed using Auc 1 computer program, which estimates the percentage of damaged area relative to that of the whole ipsilateral hemisphere. The conditions of coagulation the distal segment of middle cerebral artery were selected, which caused necrosis localized in the fronto-parietal and dorso-lateral regions of the brain cortex without any damage of subcortical structures. The extent of the brain damage in control group (treated by saline) was 18.6%, while that in the group treated with noopept was 12.2%, thus demonstrating a decrease in the infarction area by 34.5% (p < 05). The data on noopept efficacy on the model of the extensive ischemic injury of brain cortex show that this drug has good prospects for use in the neuroprotective treatment of stroke.

Detecting natural occlusion boundaries using local cues

PubMed Central

DiMattina, Christopher; Fox, Sean A.; Lewicki, Michael S.

2012-01-01

Occlusion boundaries and junctions provide important cues for inferring three-dimensional scene organization from two-dimensional images. Although several investigators in machine vision have developed algorithms for detecting occlusions and other edges in natural images, relatively few psychophysics or neurophysiology studies have investigated what features are used by the visual system to detect natural occlusions. In this study, we addressed this question using a psychophysical experiment where subjects discriminated image patches containing occlusions from patches containing surfaces. Image patches were drawn from a novel occlusion database containing labeled occlusion boundaries and textured surfaces in a variety of natural scenes. Consistent with related previous work, we found that relatively large image patches were needed to attain reliable performance, suggesting that human subjects integrate complex information over a large spatial region to detect natural occlusions. By defining machine observers using a set of previously studied features measured from natural occlusions and surfaces, we demonstrate that simple features defined at the spatial scale of the image patch are insufficient to account for human performance in the task. To define machine observers using a more biologically plausible multiscale feature set, we trained standard linear and neural network classifiers on the rectified outputs of a Gabor filter bank applied to the image patches. We found that simple linear classifiers could not match human performance, while a neural network classifier combining filter information across location and spatial scale compared well. These results demonstrate the importance of combining a variety of cues defined at multiple spatial scales for detecting natural occlusions. PMID:23255731

Occlusal adjustment using the bite plate-induced occlusal position as a reference position for temporomandibular disorders: a pilot study

PubMed Central

2010-01-01

Background Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs). However, a recent report described a discrepancy between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP) as a muscular reference position should be evaluated in patients with TMD. Methods The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI) and the Helkimo Clinical Dysfunction Index (CDI) before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment. Results The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p < 0.001). The changes in the mean HOP-BPOP differences on the x-axis (mediolateral) and the y-axis (anteroposterior) were significant (p < 0.05), whereas the change on the z-axis (superoinferior) was not significant (p > 0.1). Conclusion Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted. PMID:20346167

Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhudesai, V., E-mail: v_prabhudesai@hotmail.com; Mitra, K.; West, D. J.

2003-09-15

Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome.

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

Acute left main coronary artery occlusion

PubMed Central

Burgazli, K. Mehmet; Bilgin, Mehmet; Soydan, Nedim; Chasan, Ridvan; Erdogan, Ali

2013-01-01

The treatment of an acute left main coronary artery occlusion still poses a challenge. In this case report we present a 50-year-old patient with an acute occlusion of the left main artery. After a successful angioplasty without “stenting” due to the complexity of the stenosis the patient underwent a successful bypass surgery. We discuss the therapeutic options of acute left main occlusion regarding medical, interventional and surgical options. PMID:24353543

Inheritance of Occlusal Topography: A Twin Study

PubMed Central

Su, C-Y.; Corby, P.M.; Elliot, M.A.; Studen-Pavlovich, D.A.; Ranalli, D.N.; Rosa, B.; Wessel, J.; Schork, N.J.; Hart, T.C.; Bretz, W.A.

2011-01-01

Aim This was to determine the relative contribution of genetic factors on the morphology of occlusal surfaces of mandibular primary first molars by employing the twin study model. Methods The occlusal morphology of mandibular primary first molar teeth from dental casts of 9 monozygotic (MZ) twin pairs and 12 dizygotic (DZ) twin pairs 4 to 7 years old, were digitized by contact-type three-dimensional (3D) scanner. To compare the similarity of occlusal morphology between twin sets, each twin pair of occlusal surfaces was superimposed to establish the best fit by using computerized least squared techniques. Heritability was computed using a variance component model, adjusted for age and gender. Results DZ pairs demonstrated a greater degree of occlusal morphology variance. The total amount of difference in surface overlap was 0.0508 mm (0.0018 (inches) for the MZ (n=18) sample and 0.095 mm (0.0034 inches) for the DZ (n=24) sample and were not statistically significant (p=0.2203). The transformed mean differences were not statistically significantly different (p=0.2203). Heritability estimates of occlusal surface areas for right and left mandibular primary first molars were 97.5% and 98.2% (p<0.0001), respectively. Conclusions Occlusal morphology of DZ twin pairs was more variable than that of MZ twin pairs. Heritability estimates revealed that genetic factors strongly influence occlusal morphology of mandibular primary first molars. PMID:18328234

MRI Features in a Canine Model of Ischemic Stroke: Correlation between Lesion Volume and Neurobehavioral Status during the Subacute Stage

PubMed Central

Kang, Byeong-Teck; Jang, Dong-Pyo; Gu, Su-Hyun; Lee, Jong-Hwan; Jung, Dong-In; Lim, Chae-Young; Kim, Ha-Jung; Kim, Young-Bo; Kim, Hyung-Joong; Woo, Eung-Je; Cho, Zang-Hee; Park, Hee-Myung

2009-01-01

The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) and assess the correlation between the volume of the ischemic lesion and neurobehavioral status during the subacute stage of ischemic stroke. Ischemic stroke was induced in 6 healthy laboratory beagles through permanent occlusion of the middle cerebral artery (MCAO). T2-weighted and fluid-attenuated inversion recovery (FLAIR) imaging, diffusion-weighted imaging (DWI), measurement of the apparent diffusion coefficient (ADC) ratio, and neurobehavioral evaluation were performed 3 times serially by using a 1.5-T MR system: before and 3 and 10 d after MCAO. Ischemic lesions demonstrated T2 hyperintensity, FLAIR hyperintensity, and DWI hyperintensity. The ADC ratio was decreased initially but then was increased at 10 d after MCAO. Ischemic lesion volumes on T2-weighted and FLAIR imaging were not significantly different from those on DWI. The lesion volume and neurobehavioral score showed strong correlation. Our results suggest that conventional MRI may be a reliable diagnostic tool during the subacute stage of canine ischemic stroke. PMID:19887030

1,5-Diaminonaphthalene hydrochloride assisted laser desorption/ionization mass spectrometry imaging of small molecules in tissues following focal cerebral ischemia.

PubMed

Liu, Huihui; Chen, Rui; Wang, Jiyun; Chen, Suming; Xiong, Caiqiao; Wang, Jianing; Hou, Jian; He, Qing; Zhang, Ning; Nie, Zongxiu; Mao, Lanqun

2014-10-21

A sensitive analytical technique for visualizing small endogenous molecules simultaneously is of great significance for clearly elucidating metabolic mechanisms during pathological progression. In the present study, 1,5-naphthalenediamine (1,5-DAN) hydrochloride was prepared for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of small molecules in liver, brain, and kidneys from mice. Furthermore, 1,5-DAN hydrochloride assisted LDI MSI of small molecules in brain tissue of rats subjected to middle cerebral artery occlusion (MCAO) was carried out to investigate the altered metabolic pathways and mechanisms underlying the development of ischemic brain damage. Our results suggested that the newly prepared matrix possessed brilliant features including low cost, strong ultraviolet absorption, high salt tolerance capacity, and fewer background signals especially in the low mass range (typically m/z < 500), which permitted us to visualize the spatial distribution of a broad range of small molecule metabolites including metal ions, amino acids, carboxylic acids, nucleotide derivatives, peptide, and lipids simultaneously. Nineteen endogenous metabolites involved in metabolic networks such as ATP metabolism, tricarboxylic acid (TCA) cycle, glutamate-glutamine cycle, and malate-aspartate shuttle, together with metal ions and phospholipids as well as antioxidants underwent relatively obvious changes after 24 h of MCAO. The results were highly consistent with the data obtained by MRM MS analysis. These findings highlighted the promising potential of the organic salt matrix for application in the field of biomedical research.

Sodium-23 magnetic resonance imaging has potential for improving penumbra detection but not for estimating stroke onset time

PubMed Central

Wetterling, Friedrich; Gallagher, Lindsay; Mullin, Jim; Holmes, William M; McCabe, Chris; Macrae, I Mhairi; Fagan, Andrew J

2015-01-01

Tissue sodium concentration increases in irreversibly damaged (core) tissue following ischemic stroke and can potentially help to differentiate the core from the adjacent hypoperfused but viable penumbra. To test this, multinuclear hydrogen-1/sodium-23 magnetic resonance imaging (MRI) was used to measure the changing sodium signal and hydrogen-apparent diffusion coefficient (ADC) in the ischemic core and penumbra after rat middle cerebral artery occlusion (MCAO). Penumbra and core were defined from perfusion imaging and histologically defined irreversibly damaged tissue. The sodium signal in the core increased linearly with time, whereas the ADC rapidly decreased by >30% within 20 minutes of stroke onset, with very little change thereafter (0.5–6 hours after MCAO). Previous reports suggest that the time point at which tissue sodium signal starts to rise above normal (onset of elevated tissue sodium, OETS) represents stroke onset time (SOT). However, extrapolating core data back in time resulted in a delay of 72±24 minutes in OETS compared with actual SOT. At the OETS in the core, penumbra sodium signal was significantly decreased (88±6%, P=0.0008), whereas penumbra ADC was not significantly different (92±18%, P=0.2) from contralateral tissue. In conclusion, reduced sodium-MRI signal may serve as a viability marker for penumbra detection and can complement hydrogen ADC and perfusion MRI in the time-independent assessment of tissue fate in acute stroke patients. PMID:25335803

Breaking the Blood-Brain Barrier With Mannitol to Aid Stem Cell Therapeutics in the Chronic Stroke Brain.

PubMed

Tajiri, Naoki; Lee, Jea Young; Acosta, Sandra; Sanberg, Paul R; Borlongan, Cesar V

2016-01-01

Blood-brain barrier (BBB) permeabilizers, such as mannitol, can facilitate peripherally delivered stem cells to exert therapeutic benefits on the stroke brain. Although this BBB permeation-aided stem cell therapy has been demonstrated in the acute stage of stroke, such BBB permeation in the chronic stage of the disease remains to be examined. Adult Sprague-Dawley rats initially received sham surgery or experimental stroke via the 1-h middle cerebral artery occlusion (MCAo) model. At 1 month after the MCAo surgery, stroke animals were randomly assigned to receive human umbilical cord stem cells only (2 million viable cells), mannitol only (1.1 mol/L mannitol at 4°C), combined human umbilical cord stem cells (200,000 viable cells) and mannitol (1.1 mol/L mannitol at 4°C), and vehicle (phosphate-buffered saline) only. Stroke animals that received human umbilical cord blood cells alone or combined human umbilical cord stem cells and mannitol exhibited significantly improved motor performance and significantly better brain cell survival in the peri-infarct area compared to stroke animals that received vehicle or mannitol alone, with mannitol treatment reducing the stem cell dose necessary to afford functional outcomes. Enhanced neurogenesis in the subventricular zone accompanied the combined treatment of human umbilical cord stem cells and mannitol. We showed that BBB permeation facilitates the therapeutic effects of a low dose of peripherally transplanted stem cells to effectively cause functional improvement and increase neurogenesis in chronic stroke.

Evaluation of Aged Garlic Extract Neuroprotective Effect in a Focal Model of Cerebral Ischemia

NASA Astrophysics Data System (ADS)

Aguilera, Penélope; Maldonado, Perla D.; Ortiz-Plata, Alma; Barrera, Diana; Chánez-Cárdenas, María Elena

2008-02-01

The oxidant species generated in cerebral ischemia have been implicated as important mediators of neuronal injury through damage to lipids, DNA, and proteins. Since ischemia as well as reperfusion insults generate oxidative stress, the administration of antioxidants may limit oxidative damage and ameliorate disease progression. The present work shows the transitory neuroprotective effect of the aged garlic extract (AGE) administration (a proposed antioxidant compound) in a middle cerebral artery occlusion (MCAO) model in rats and established its therapeutic window. To determine the optimal time of administration, animal received AGE (1.2 mL/kg) intraperitoneally 30 min before onset of reperfusion (-0.5 R), at the beginning of reperfusion (0R), or 1 h after onset of reperfusion (1R). Additional doses were administrated after 1, 2, or 3 h after onset of reperfusion. To establish the therapeutic window of AGE, the infarct area was determined for each treatment after different times of reperfusion. Results show that the administration of AGE at the onset of reperfusion reduced the infarct area by 70% (evaluated after 2 h reperfusion). The therapeutic window of AGE was determined. Repeated doses did not extend the temporal window of protection. A significant reduction in the nitrotyrosine level was observed in the brain tissue subjected to MCAO after AGE treatment at the onset of reperfusion. Data in the present work show that AGE exerts a transitory neuroprotective effect in response to ischemia/reperfusion-induced neuronal injury.

The 15-LO-1/15-HETE system promotes angiogenesis by upregulating VEGF in ischemic brains.

PubMed

Chen, Li; Zhu, Yan-Mei; Li, Yu-Nong; Li, Peng-Yan; Wang, Di; Liu, Yu; Qu, You-Yang; Zhu, Da-Ling; Zhu, Yu-Lan

2017-09-01

Angiogenesis promotes neurobehavioral recovery after cerebral ischemic stroke. 15(S)-hydroxyeicosatetraenoic acid (15-HETE) is one of the major metabolites of arachidonic acid by 15-lipoxygenase (15-LO) and stimulates the production of vascular endothelial growth factor (VEGF), thus, inducing autocrine-mediated angiogenesis. The present study aimed to investigate the role of 15-LO/15-HETE system on VEGF expression and angiogenesis in brain ischemia. Rat cerebral arterial vascular endothelial cells were used to set up a cell injury model of oxygen-glucose deprivation and reoxygenation (OGD/R), mimicking a condition of brain ischemia. A mouse model of middle cerebral artery occlusion (MCAO) was established. Oxygen-glucose deprivation increased cellular expression of 15-LO-1 and VEGF. Transfection of 15-LO-1 siRNA depleted cells of 15-LO-1, and sequentially induced downregulation of VEGF expression; while, incubation of 15-HETE increased the expression of VEGF. Incubation of 15-HETE attenuated the reduction in cell viability induced by oxygen-glucose deprivation, and promoted cell migration, while transfection of 15-LO-1 siRNA showed an opposite effect. In animal experiments, the density of microvessels in hypoxic regions of brains was significantly increased after MCAO, while intracerebroventricular delivery of 15-LO-1 siRNA significantly reduced the density of microvessels, and downregulates VEGF expression. The results indicate that the 15-LO-1/15-HETE system promotes angiogenesis in ischemic brains by upregulation of VEGF, representing a potential target for improving neurobehavioral recovery after cerebral ischemic stroke.

Naturally occurring marine steroid 24-methylenecholestane-3β,5α,6β,19-tetraol functions as a novel neuroprotectant.

PubMed

Leng, Tiandong; Liu, Ailing; Wang, Youqiong; Chen, Xinying; Zhou, Shujia; Li, Qun; Zhu, Wenbo; Zhou, Yuehan; Su, Xingwen; Huang, Yijun; Yin, Wei; Qiu, Pengxin; Hu, Haiyan; Xiong, Zhi-gang; Zhang, Jingxia; Yan, Guangmei

2016-01-01

Steroids have been shown to have multiple effects on the nervous system including neuroprotective activities, and they have the potential to be used for the treatment of neurodegenerative diseases. In this current study, we tested the hypothesis that the marine steroid 24-methylenecholestane-3β,5α,6β,19-tetraol (Tetrol) has a neuroprotective effect. (1) We synthesized Tetrol through a multiple step reaction starting from hyodeoxycholic acid (HDCA). (2) We then evaluated the neuroprotective effect of Tetrol with a glutamate-induced neuronal injury model in vitro. Tetrol concentration dependently increased the survival rate of cerebellar granule neurons challenged with toxic concentration of glutamate. Consistently, Tetrol significantly decreased glutamate-induced lactate dehydrogenase (LDH) release with a threshold concentration of 2.5 μM. (3) We further evaluated the neuroprotective effect of Tetrol in a middle cerebral artery occlusion (MCAO)-induced cerebral ischemia model in rat. Tetrol, at a dose of 12 mg/kg, significantly decreased MCAO-induced infarction volume by ∼50%. (4) Finally, we probed the mechanism and found that Tetrol concentration dependently attenuated N-methyl-d-aspartate (NMDA)-induced intracellular calcium ([Ca(2+)]i) increase with an IC50 of 7.8±0.62 μM, and inhibited NMDA currents in cortical neurons with an IC50 of 10.28±0.71 μM. Taken together, we have synthesized and characterized Tetrol as a novel neuroprotectant through negative modulation of NMDA receptors. Copyright © 2015. Published by Elsevier Inc.

Ultrasonic assessment of cerebral blood flow changes during ischemia-reperfusion in 7-day-old rats.

PubMed

Bonnin, Philippe; Debbabi, Haythem; Mariani, Jean; Charriaut-Marlangue, Christiane; Renolleau, Sylvain

2008-06-01

A model of ischemic brain injury in 7-day-old rat pups has been developed to study perinatal ischemia. It combines permanent occlusion of the distal left middle cerebral artery (LMCA) and transient occlusion of homolateral common carotid artery (LCCA). At removal of the clip on LCCA, reflow allowed brain reperfusion through cortical anastomoses. In 10 rat pups, we measured blood flow velocities (BFV) in main cerebral arteries with 12-MHz ultrasound imaging. At basal states, peak systolic BFV in proximal LMCA was 16.0 +/- 3.0 cm.s(-1). Occlusion of LMCA did not yield significant modifications. Occlusion of LCCA involved only a decrease in BFV to 9.5 +/- 2.6 cm.s(-1) (p < 0.001). Indeed, LMCA was then supply by the right internal carotid and the vertebral arteries through the circle of Willis. In three rat pups, release of occlusion of LCCA was followed by restoration of BFV in the left internal carotid artery and in LMCA, in seven pups, by a reversed flow in the LICA and lower BFV in LMCA (11.9 +/- 2.3, p < 0.05). BFV returned to basal values from h5 to h48 in all animals. In addition, ultrasound imaging is a useful, reproducible, non invasive, easy-to-repeat, method to assess and monitor arterial cerebral blood flow supply in small animals. It helps to characterize changes occurring during cerebral ischemia and reperfusion, particularly the depth of the hypoperfusion, as well as the variability of reflow. In preclinical studies, this method could help to identify what can be assigned to a neuroprotective treatment and what depends on changes in cerebral blood flow supply.

Neuromuscular dentistry: Occlusal diseases and posture.

PubMed

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.

Identification of the boundary between normal brain tissue and ischemia region using two-photon excitation fluorescence microscopy

NASA Astrophysics Data System (ADS)

Du, Huiping; Wang, Shu; Wang, Xingfu; Zhu, Xiaoqin; Zhuo, Shuangmu; Chen, Jianxin

2016-10-01

Ischemic stroke is one of the common neurological diseases, and it is becoming the leading causes of death and permanent disability around the world. Early and accurate identification of the potentially salvageable boundary region of ischemia brain tissues may enable selection of the most appropriate candidates for early stroke therapies. In this work, TPEF microscopy was used to image the microstructures of normal brain tissues, ischemia regions and the boundary region between normal and ischemia brain tissues. The ischemia brain tissues from Sprague-Dawley (SD) rats were subjected to 6 hours of middle cerebral artery occlusion (MCAO). Our study demonstrates that TPEF microscopy has the ability to not only reveal the morphological changes of the neurons but also identify the boundary between normal brain tissue and ischemia region, which correspond well to the hematoxylin and eosin (H and E) stained images. With the development of miniaturized TPEF microscope imaging devices, TPEF microscopy can be developed into an effectively diagnostic and monitoring tool for cerebral ischemia.

A non-ionotropic activity of NMDA receptors contributes to glycine-induced neuroprotection in cerebral ischemia-reperfusion injury.

PubMed

Chen, Juan; Hu, Rong; Liao, Huabao; Zhang, Ya; Lei, Ruixue; Zhang, Zhifeng; Zhuang, Yang; Wan, Yu; Jin, Ping; Feng, Hua; Wan, Qi

2017-06-15

NMDA receptor (NMDAR) is known for its ionotropic function. But recent evidence suggests that NMDAR also has a non-ionotropic property. To determine the role of non-ionotropic activity of NMDARs in clinical relevant conditions, we tested the effect of glycine, a co-agonist of NMDARs, in rat middle cerebral artery occlusion (MCAO), an animal model of cerebral ischemia-reperfusion injury after the animals were injected with the NMDAR channel blocker MK-801 and the glycine receptor antagonist strychnine. We show that glycine reduces the infarct volume in the brain of ischemic stroke animals pre-injected with MK-801 and strychnine. The effect of glycine is sensitive to the antagonist of glycine-GluN1 binding site and blocked by Akt inhibition. In the neurobehavioral tests, glycine improves the functional recovery of stroke animals pre-injected with MK-801 and strychnine. This study suggests that glycine-induced neuroprotection is mediated in part by the non-ionotropic activity of NMDARs via Akt activation in cerebral ischemia-reperfusion injury.

Biomechanics of occlusion--implications for oral rehabilitation.

PubMed

Peck, C C

2016-03-01

The dental occlusion is an important aspect of clinical dentistry; there are diverse functional demands ranging from highly precise tooth contacts to large crushing forces. Further, there are dogmatic, passionate and often diverging views on the relationship between the dental occlusion and various diseases and disorders including temporomandibular disorders, non-carious cervical lesions and tooth movement. This study provides an overview of the biomechanics of the masticatory system in the context of the dental occlusion's role in function. It explores the adaptation and precision of dental occlusion, its role in bite force, jaw movement, masticatory performance and its influence on the oro-facial musculoskeletal system. Biomechanics helps us better understand the structure and function of biological systems and consequently an understanding of the forces on, and displacements of, the dental occlusion. Biomechanics provides insight into the relationships between the dentition, jaws, temporomandibular joints, and muscles. Direct measurements of tooth contacts and forces are difficult, and biomechanical models have been developed to better understand the relationship between the occlusion and function. Importantly, biomechanical research will provide knowledge to help correct clinical misperceptions and inform better patient care. The masticatory system demonstrates a remarkable ability to adapt to a changing biomechanical environment and changes to the dental occlusion or other components of the musculoskeletal system tend to be well tolerated. © 2015 John Wiley & Sons Ltd.

Dental occlusion and temporomandibular disorders.

PubMed

Stone, J Caitlin; Hannah, Andrew; Nagar, Nathan

2017-10-27

Data sourcesMedline, Scopus and Google Scholar.Study selectionTwo reviewers selected studies independently. English language clinical studies assessing the association between temporomandibular disorders (TMD) and features of dental occlusion were considered.Data extraction and synthesisStudy quality was assessed based on the Newcastle-Ottawa Scale (NOS) and a narrative synthesis was presented.ResultsIn all 25 studies (17 case-control, eight comparative) were included. Overall there was a high variability between occlusal features and TMD diagnosis. Findings were consistent with a lack of clinically relevant association between TMD and dental occlusion. Only two studies were associated with TMD in the majority (≥50%) of single variable analyses in patient populations. Only mediotrusive interferences are associated with TMD in the majority of multiple variable analyses.ConclusionsThe findings support the absence of a disease-specific association, there is no ground to hypothesise a major role for dental occlusion in the pathophysiology of TMDs. Dental clinicians are thus encouraged to move forward and abandon the old-fashioned gnathological paradig.

Conventional occlusion versus pharmacologic penalization for amblyopia.

PubMed

Li, Tianjing; Shotton, Kate

2009-10-07

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses. To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia. We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009. We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia. Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias. Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and

Necrotizing Fasciitis of the Periorbital Region Complicated by Combined Central Retinal Artery Occlusion, Central Retinal Vein Occlusion, and Posterior Ciliary Occlusion.

PubMed

Sultan, Harris; Malik, Amina; Li, Helen K; Chévez-Barrios, Patricia; Lee, Andrew G

A 50 year-old man on immunosuppressive agents presented with left eye vision loss, periorbital swelling, pain, and ophthalmoplegia. The patient was clinically found to have a central retinal artery and vein occlusion. A CT scan was performed which demonstrated intraorbital fat stranding, however the patient lacked sinus disease. The etiology of the orbital infection was held in question. The area was debrided in the operating room, and the specimen demonstrated group A streptococcal species consistent with necrotizing fasciitis. Periorbital necrotizing fasciitis should be suspected in patients with rapidly progressive orbital symptoms without sinus disease as lack of surgical intervention can result in poor outcomes. The unusual aspect to this case is the mechanism of vision loss, as the authors hypothesize that there was vascular infiltration of the infection resulting in the central retinal artery occlusion and central retinal vein occlusion which have not been previously reported secondary to necrotizing fasciitis of the orbit.

Neuromuscular dentistry: Occlusal diseases and posture

PubMed Central

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K.

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture. PMID:25737904

Glatiramer Acetate administration does not reduce damage after cerebral ischemia in mice.

PubMed

Poittevin, Marine; Deroide, Nicolas; Azibani, Feriel; Delcayre, Claude; Giannesini, Claire; Levy, Bernard I; Pocard, Marc; Kubis, Nathalie

2013-01-15

Inflammation plays a key role in ischemic stroke pathophysiology: microglial/macrophage cells and type-1 helper cells (Th1) seem deleterious, while type-2 helper cells (Th2) and regulatory T cells (Treg) seem protective. CD4 Th0 differentiation is modulated by microglial cytokine secretion. Glatiramer Acetate (GA) is an immunomodulatory drug that has been approved for the treatment of human multiple sclerosis by means of a number of mechanisms: reduced microglial activation and pro-inflammatory cytokine production, Th0 differentiation shifting from Th2 to Th2 and Treg with anti-inflammatory cytokine production and increased neurogenesis. We induced permanent (pMCAo) or transient middle cerebral artery occlusion (tMCAo) and GA (2 mg) or vehicle was injected subcutaneously immediately after cerebral ischemia. Mice were sacrificed at D3 to measure neurological deficit, infarct volume, microglial cell density and qPCR of TNFα and IL-1β (pro-inflammatory microglial cytokines), IFNγ (Th2 cytokine), IL-4 (Th2 cytokine), TGFβ and IL-10 (Treg cytokines), and at D7 to evaluate neurological deficit, infarct volume and neurogenesis assessment. We showed that in GA-treated pMCAo mice, infarct volume, microglial cell density and cytokine secretion were not significantly modified at D3, while neurogenesis was enhanced at D7 without significant infarct volume reduction. In GA-treated tMCAo mice, microglial pro-inflammatory cytokines IL-1β and TNFα were significantly decreased without modification of microglial/macrophage cell density, cytokine secretion, neurological deficit or infarct volume at D3, or modification of neurological deficit, neurogenesis or infarct volume at D7. In conclusion, Glatiramer Acetate administered after cerebral ischemia does not reduce infarct volume or improve neurological deficit in mice despite a significant increase in neurogenesis in pMCAo and a microglial pro-inflammatory cytokine reduction in tMCAo. Copyright © 2012 Elsevier B.V. All rights

Human Neural Stem Cell Extracellular Vesicles Improve Recovery in a Porcine Model of Ischemic Stroke

PubMed Central

Webb, Robin L.; Kaiser, Erin E.; Jurgielewicz, Brian J.; Spellicy, Samantha; Scoville, Shelley L.; Thompson, Tyler A.; Swetenburg, Raymond L.; Hess, David C.; West, Franklin D.

2018-01-01

Background and Purpose— Recent work from our group suggests that human neural stem cell–derived extracellular vesicle (NSC EV) treatment improves both tissue and sensorimotor function in a preclinical thromboembolic mouse model of stroke. In this study, NSC EVs were evaluated in a pig ischemic stroke model, where clinically relevant end points were used to assess recovery in a more translational large animal model. Methods— Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO), and either NSC EV or PBS treatment was administered intravenously at 2, 14, and 24 hours post-MCAO. NSC EV effects on tissue level recovery were evaluated via magnetic resonance imaging at 1 and 84 days post-MCAO. Effects on functional recovery were also assessed through longitudinal behavior and gait analysis testing. Results— NSC EV treatment was neuroprotective and led to significant improvements at the tissue and functional levels in stroked pigs. NSC EV treatment eliminated intracranial hemorrhage in ischemic lesions in NSC EV pigs (0 of 7) versus control pigs (7 of 8). NSC EV–treated pigs exhibited a significant decrease in cerebral lesion volume and decreased brain swelling relative to control pigs 1-day post-MCAO. NSC EVs significantly reduced edema in treated pigs relative to control pigs, as assessed by improved diffusivity through apparent diffusion coefficient maps. NSC EVs preserved white matter integrity with increased corpus callosum fractional anisotropy values 84 days post-MCAO. Behavior and mobility improvements paralleled structural changes as NSC EV–treated pigs exhibited improved outcomes, including increased exploratory behavior and faster restoration of spatiotemporal gait parameters. Conclusions— This study demonstrated for the first time that in a large animal model novel NSC EVs significantly improved neural tissue preservation and functional levels post-MCAO, suggesting NSC EVs may be a paradigm changing stroke therapeutic

Role of a Burr Hole and Calvarial Bone Marrow-Derived Stem Cells in the Ischemic Rat Brain: A Possible Mechanism for the Efficacy of Multiple Burr Hole Surgery in Moyamoya Disease.

PubMed

Nam, Taek-Kyun; Park, Seung-Won; Park, Yong-Sook; Kwon, Jeong-Taik; Min, Byung-Kook; Hwang, Sung-Nam

2015-09-01

This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD). Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done. In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis. Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.

[Studies on the correlation between the expression of Toll-like receptor 4 and the synovitis of the temporomandibular joint in rats].

PubMed

Kong, Jingjing; Wu, Qingting; Wang, Xiaohui; Yang, Yingying; Lin, Xuefen; Ji, Ping

2014-08-01

To investigate the expression of the Toll-like receptor-4 (TLR-4) in temporo-mandibular joint synovitis in rats, and to discuss the correlation between the expression of TLR-4 and the synovitis. Sixty male wistar rats were randomly divided into five groups, 12 each. Group A was the control group in which the rats were given normal diet.In Group B, the rats' bilateral masseter muscles were cut off (masseter resection group). In Group C, An cast metal crown were bonded on the mandibular right first molar of each rat (occlusal interference group). In Group D, occlusal pad were bonded on maxillary molars of each rat (occlusal dimension increase group). In Group E, rats' bilateral masseter muscles were re-sected and occlusal pads were bonded on their maxillary molars (masseter resection and occlusal dimension increase group). Pathological changes of synovium were observed using hematoxylin and eosin (HE) stains and pathology scores were evaluated. The expression of TLR- 4 were determined by immunohistochemical stains, and the expression of TLR-4 mRNA were determined by real-time PCR. The correlation between the expression of TLR-4, TLR-4 mRNA and the pathological score were analyzed using Spearman analysis. The pathological scores of Group A-E were 0.5 ± 0.5, 2.5 ± 1.0, 2.7 ± 1.0, 3.0 ± 0.9, 5.3 ± 1.2 respectively. The expression of TLR-4 were (3.2 ± 1.5)%, (16.± 2.6)%, (15.8 ± 2.1)%, (17.5 ± 2.4)%, (38.2 ± 4.4) %. The expression of TLR-4 mRNA were 1.07 ± 0.09, 2.12 ± 0.33, 2.07 ± 0.29, 2.17 ± 0.34, 4.53 ± 0.46. Compared with group A, groups B- E showed significant higher pathology score (P < 0.05) and increased expression of both TLR-4 (P < 0.05) and TLR-4 mRNA (P < 0.05). An significant positive correlation was found between the expression of TLR- 4 and the pathology score (r = 0.785, P < 0.05), and between the expression of TLR- 4 mRNA and the pathology score (r = 0.720, P < 0.05). TLR-4 may be closely associated with the development of the synovitis

Hypoglycemia Prevents Increase in Lactic Acidosis During Reperfusion After Temporary Cerebral Ischemia in Rats

PubMed Central

Sappey-Marinier, Dominique; Chileuitt, Laureano; Weiner, Michael W.; Faden, Alan I.; Weinstein, Philip R.

2009-01-01

Sequential 31P and 1H MRS was used to measure cerebral phosphate metabolites, intracellular pH, and lactate in normoglycemic and hypoglycemic rats during 30 min of complete cerebral ischemia and 5.5 h of reperfusion. These results were correlated with brain levels of free fatty acids (FFAs), excitatory amino acids, cations, and water content at death. The lactate/N-acetyl aspartate ratio was not significantly different between groups before or during occlusion. During reperfusion, the ratio was higher in normoglycemic rats from 3 to 85 min (p≤ 0.05), and recovery time was faster in hypoglycemic rats (29 vs 45 min; p = 0.04), suggesting reduced lactate production and faster recovery of aerobic metabolism. During occlusion, significant but comparable decrease of intracellular pH occurred in each group. Intracellular pH was higher in hypoglycemic rats at 140 min and 260 min of reperfusion. Water content, Na and K+ concentrations, and FFA and excitatory amino acid levels were not significantly different between groups, but hypoglycemic rats had less depletion of levels of Mg2+ (p=0.011). These results show that hypoglycemia has a limited but potentially beneficial effect on postischemic lactic acidosis. PMID:8771092

Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia.

PubMed

Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta; Klohs, Jan

2017-08-01

Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia.

Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia

PubMed Central

Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta

2016-01-01

Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia. PMID:27789786

The role of "rescue saccades" in tracking objects through occlusions.

PubMed

Zelinsky, Gregory J; Todor, Andrei

2010-12-29

We hypothesize that our ability to track objects through occlusions is mediated by timely assistance from gaze in the form of "rescue saccades"-eye movements to tracked objects that are in danger of being lost due to impending occlusion. Observers tracked 2-4 target sharks (out of 9) for 20 s as they swam through a rendered 3D underwater scene. Targets were either allowed to enter into occlusions (occlusion trials) or not (no occlusion trials). Tracking accuracy with 2-3 targets was ≥ 92% regardless of target occlusion but dropped to 74% on occlusion trials with four targets (no occlusion trials remained accurate; 83%). This pattern was mirrored in the frequency of rescue saccades. Rescue saccades accompanied approximatlely 50% of the Track 2-3 target occlusions, but only 34% of the Track 4 occlusions. Their frequency also decreased with increasing distance between a target and the nearest other object, suggesting that it is the potential for target confusion that summons a rescue saccade, not occlusion itself. These findings provide evidence for a tracking system that monitors for events that might cause track loss (e.g., occlusions) and requests help from the oculomotor system to resolve these momentary crises. As the number of crises increase with the number of targets, some requests for help go unsatisfied, resulting in degraded tracking.

Optical-resolution photoacoustic microscopy of ischemic stroke

NASA Astrophysics Data System (ADS)

Hu, Song; Gonzales, Ernie; Soetikno, Brian; Gong, Enhao; Yan, Ping; Maslov, Konstantin; Lee, Jin-Moo; Wang, Lihong V.

2011-03-01

A major obstacle in understanding the mechanism of ischemic stroke is the lack of a tool to noninvasively or minimally invasively monitor cerebral hemodynamics longitudinally. Here, we applied optical-resolution photoacoustic microscopy (OR-PAM) to longitudinally study ischemic stroke induced brain injury in a mouse model with transient middle cerebral artery occlusion (MCAO). OR-PAM showed that, during MCAO, the average hemoglobin oxygen saturation (sO2) values of feeder arteries and draining veins within the stroke core region dropped ~10% and ~34%, respectively. After reperfusion, arterial sO2 recovered back to the baseline; however, the venous sO2 increased above the baseline value by ~7%. Thereafter, venous sO2 values were close to the arterial sO2 values, suggesting eventual brain tissue infarction.

Vascular occlusion with a balloon-expandable stent occluder.

PubMed

Moss, J G; Laborde, J C; Clem, M C; Rivera, F J; Encarnacion, C E; Meyer, K B; Palmaz, J C

1994-05-01

To evaluate the effectiveness of a new vascular occlusion device. The device was created by coating a balloon-expandable stent with a silicone sleeve that tapers to a blind-ended nozzle at its leading end. Once crimp-mounted on an angioplasty balloon catheter, the device is introduced over a guide wire through a small end hole in the nozzle. The device was tested for stability and occlusive ability. No migration was measured over a pulsatile pulse range of 50-300 mm Hg, and mean flow rate in the occluded vessel was reduced from 443 mL/min +/- 99 (standard deviation) to 1.9 mL/min +/- 2.7. Subsequently, 12 arteries were occluded in three dogs, and immediate vascular occlusion was achieved in all vessels. An arteriovenous fistula was created in another six dogs and was successfully occluded with the device. Follow-up arteriography at 3 months demonstrated persistent occlusion with no migration of the device. This new occlusive device offers immediate vascular occlusion with excellent stability.

A New Occlusion Device: Application of the ArtVentive Endoluminal Occlusion System (EOS)—First in Human Clinical Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venbrux, Anthony C., E-mail: avenbrux@mfa.gwu.edu; Rudakov, Leon, E-mail: leonrudakov@artventivemedical.com; Plass, Andre, E-mail: andre.plass@usz.ch

2013-05-24

PurposeThe purpose of this study was to determine the safety and efficacy of a new endoluminal occlusion device, ArtVentive endoluminal occlusion system (EOS), to occlude the spermatic vein in symptomatic males with varicoceles.MethodsThe ArtVentive EOS device has been developed for percutaneous, peripheral occlusion of the peripheral arterial and venous vasculature. The system is comprised of an implantable occlusion device and a delivery catheter. At present, there are two device sizes: (a) size 1 for target vessels ranging between 3.5 and 5.5 mm in diameter, and (b) size 2 for target vessels 5.5–8.5 mm in diameter. The treatment group included six adult males,more » ages 22–34 years. Nine target vessels were occluded. A total of 20 devices were implanted in six subjects.ResultsThe acute occlusion rate at the end of the procedure was 100 % occurring in nine of nine vessels. The spermatic veins of all patients remained occluded on venography at 30 days follow-up. Pain scores related to varicoceles decreased in five of six patients.ConclusionsAlthough we recognize this study is limited, initial experience indicates that the ArtVentive EOS is a safe and effective new device for occlusion of vessels (varicoceles). The device has potential applications in other clinical conditions requiring occlusion of veins or arteries.« less

Occlusal considerations in implant therapy: clinical guidelines with biomechanical rationale.

PubMed

Kim, Yongsik; Oh, Tae-Ju; Misch, Carl E; Wang, Hom-Lay

2005-02-01

Due to lack of the periodontal ligament, osseointegrated implants, unlike natural teeth, react biomechanically in a different fashion to occlusal force. It is therefore believed that dental implants may be more prone to occlusal overloading, which is often regarded as one of the potential causes for peri-implant bone loss and failure of the implant/implant prosthesis. Overloading factors that may negatively influence on implant longevity include large cantilevers, parafunctions, improper occlusal designs, and premature contacts. Hence, it is important to control implant occlusion within physiologic limit and thus provide optimal implant load to ensure a long-term implant success. The purposes of this paper are to discuss the importance of implant occlusion for implant longevity and to provide clinical guidelines of optimal implant occlusion and possible solutions managing complications related to implant occlusion. It must be emphasized that currently there is no evidence-based, implant-specific concept of occlusion. Future studies in this area are needed to clarify the relationship between occlusion and implant success.

2-(2-Benzofuranyl)-2-Imidazoline Mediates Neuroprotection by Regulating the Neurovascular Unit Integrity in a Rat Model of Focal Cerebral Ischemia.

PubMed

Zhang, Zheng; Zhang, Linlei; Chen, Jiaou; Cao, Yungang; Qu, Man; Lin, Xinda; Han, Zhao; Ji, Xunming

2018-06-01

We showed previously that 2-(2-benzofuranyl)-2-imidazoline (2-BFI), a ligand to type 2 imidazoline receptor (I2R) exerts neuroprotective effects in ischemia stroke via an unknown mechanism. The present study was to investigate whether 2-BFI can protect the neurovascular unit (NVU) using a rat model of 90 min focal cerebral ischemia. Rats were randomly divided into three groups: thesham-operated group; the vehicle control group and the 2-BFI group which received 2-BFI (3 mg/kg) immediately after the start of middle cerebralartery occlusion (MCAO). Neurological deficit score, infarct size, apoptosis level, brain water content and Evans Blue extravasation were assessed at 24 h after stroke. Expressions of occludin and zonula occludens 1 (ZO-1), collagen IV, aquaporin-4 (AQP-4), matrix metalloproteinase-9 (MMP-9) and MMP-2 were assessed by Western blotting. 2-BFI treatment was associated with significant improvement of neurological performance and decreased infarct volume at 24 h after stroke. Apoptosis level reduced significantly by 2-BFI compared to the vehicle group (34.3 ± 5.4% vs 56.1 ± 7.9%, p < 0.05). Significant decreased of brain water content (79.5 ± 2.6% vs 84.62 ± 2%, p < 0.05) and Evans Blue extravasation (1.2 ± 0.5 vs 2.5 ± 0.41 µg/g, p < 0.05) of ipsilateral hemisphere was observed in 2-BFI group compared to vehicle group. Expressions of occludin, ZO-1 and collagen IV were significantly higher while MMP-9 level significantly lower in 2-BFI group. AQP-4 and MMP-2 showed no difference between 2-BFI and the vehicle groups. These results suggest that the neuroprotective effects of 2-BFI in acute ischemic brain damage are at least partly due to the drug's ability to improve the functions of NVU. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Fumarate decreases edema volume and improves functional outcome after experimental stroke.

PubMed

Clausen, Bettina Hjelm; Lundberg, Louise; Yli-Karjanmaa, Minna; Martin, Nellie Anne; Svensson, Martina; Alfsen, Maria Zeiler; Flæng, Simon Bertram; Lyngsø, Kristina; Boza-Serrano, Antonio; Nielsen, Helle H; Hansen, Pernille B; Finsen, Bente; Deierborg, Tomas; Illes, Zsolt; Lambertsen, Kate Lykke

2017-09-01

Oxidative stress and inflammation exacerbate tissue damage in the brain after ischemic stroke. Dimethyl-fumarate (DMF) and its metabolite monomethyl-fumarate (MMF) are known to stimulate anti-oxidant pathways and modulate inflammatory responses. Considering these dual effects of fumarates, we examined the effect of MMF treatment after ischemic stroke in mice. Permanent middle cerebral artery occlusion (pMCAO) was performed using adult, male C57BL/6 mice. Thirty minutes after pMCAO, 20mg/kg MMF was administered intravenously. Outcomes were evaluated 6, 24 and 48h after pMCAO. First, we examined whether a bolus of MMF was capable of changing expression of kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor (Nrf)2 in the infarcted brain. Next, we studied the effect of MMF on functional recovery. To explore mechanisms potentially influencing functional changes, we examined infarct volumes, edema formation, the expression of heat shock protein (Hsp)72, hydroxycarboxylic acid receptor 2 (Hcar2), and inducible nitric oxide synthase (iNOS) in the infarcted brain using real-time PCR and Western blotting. Concentrations of a panel of pro- and anti-inflammatory cytokines (IFNγ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, TNF) were examined in both the infarcted brain tissue and plasma samples 6, 24 and 48h after pMCAO using multiplex electrochemoluminiscence analysis. Administration of MMF increased the protein level of Nrf2 6h after pMCAO, and improved functional outcome at 24 and 48h after pMCAO. MMF treatment did not influence infarct size, however reduced edema volume at both 24 and 48h after pMCAO. MMF treatment resulted in increased Hsp72 expression in the brain 6h after pMCAO. Hcar2 mRNA levels increased significantly 24h after pMCAO, but were not different between saline- and MMF-treated mice. MMF treatment also increased the level of the anti-inflammatory cytokine IL-10 in the

Occlusion issues in early Renaissance art

PubMed Central

Gillam, Barbara

2011-01-01

Early Renaissance painters innovatively attempted to depict realistic three-dimensional scenes. A major problem was to produce the impression of overlap for surfaces that occlude one another in the scene but are adjoined in the picture plane. Much has been written about perspective in art but little about occlusion. Here I examine some of the strategies for depicting occlusion used by early Renaissance painters in relation to ecological considerations and perceptual research. Perceived surface overlap is often achieved by implementing the principle that an occluding surface occludes anything behind it, so that occlusion perception is enhanced by a lack of relationship of occluding contour to occluded contours. Some well-known figure-ground principles are also commonly used to stratify adjoined figures. Global factors that assist this stratification include the placement of figures on a ground plane, a high viewpoint, and figure grouping. Artists of this period seem to have differed on whether to occlude faces and heads, often carefully avoiding doing so. Halos were either eliminated selectively or placed oddly to avoid such occlusions. Finally, I argue that the marked intransitivity in occlusion by architecture in the paintings of Duccio can be related to the issue of perceptual versus cognitive influences on the visual impact of paintings. PMID:23145262

Neuroprotective effect of cathodal transcranial direct current stimulation in a rat stroke model.

PubMed

Notturno, Francesca; Pace, Marta; Zappasodi, Filippo; Cam, Etrugul; Bassetti, Claudio L; Uncini, Antonino

2014-07-15

Experimental focal brain ischemia generates in the penumbra recurrent depolarizations which spread across the injured cortex inducing infarct growth. Transcranial direct current stimulation can induce a lasting, polarity-specific, modulation of cortical excitability. To verify whether cathodal transcranial direct current stimulation could reduce the infarct size and the number of depolarizations, focal ischemia was induced in the rat by the 3 vessels occlusion technique. In the first experiment 12 ischemic rats received cathodal stimulation (alternating 15 min on and 15 min off) starting 45 min after middle cerebral artery occlusion and lasting 4 h. In the second experiment 12 ischemic rats received cathodal transcranial direct current stimulation with the same protocol but starting soon after middle cerebral artery occlusion and lasting 6 h. In both experiments controls were 12 ischemic rats not receiving stimulation. Cathodal stimulation reduced the infarct volume in the first experiment by 20% (p=0.002) and in the second by 30% (p=0.003). The area of cerebral infarction was smaller in animals receiving cathodal stimulation in both experiments (p=0.005). Cathodal stimulation reduced the number of depolarizations (p=0.023) and infarct volume correlated with the number of depolarizations (p=0.048). Our findings indicate that cathodal transcranial direct current stimulation exert a neuroprotective effect in the acute phase of stroke possibly decreasing the number of spreading depolarizations. These findings may have translational relevance and open a new avenue in neuroprotection of stroke in humans. Copyright © 2014. Published by Elsevier B.V.

Time to aortic occlusion: It's all about access.

PubMed

Romagnoli, Anna; Teeter, William; Pasley, Jason; Hu, Peter; Hoehn, Melanie; Stein, Deborah; Scalea, Thomas; Brenner, Megan

2017-12-01

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a less invasive method of proximal aortic occlusion compared with resuscitative thoracotomy with aortic cross-clamping (RTACC). This study compared time to aortic occlusion with REBOA and RTACC, both including and excluding time required for common femoral artery (CFA) cannulation. This was a retrospective, single-institution review of REBOA or RTACC performed between February 2013 and January 2016. Time of skin incision to aortic cross-clamp for RTACC, time required for CFA cannulation by percutaneous and open methods, and time from guide-wire insertion to balloon inflation at Zone 1 for REBOA, were obtained from videographic recordings. Eighteen RTACC and 21 REBOAs were performed. Median (Q1, Q3) time from skin incision to aortic cross-clamping was 317 seconds (227, 551 seconds). Median (Q1, Q3) time from start of arterial access to Zone 1 balloon occlusion was 474 seconds (431, 572 seconds) (vs. RTACC, p = 0.01). All REBOA procedures were performed with the same device. The median time to complete CFA cannulation was 247 seconds (range, 164-343 seconds), with no difference between percutaneous or open procedures (p = 0.07). The median (Q1, Q3) time to aortic occlusion in REBOA once arterial access had been established was 245 seconds (179, 295.5 seconds), which was significantly shorter than RTACC (p = 0.003). Once CFA access is achieved, time to aortic occlusion is faster with REBOA. Time to aortic occlusion is less than the time required to cannulate the CFA either by percutaneous or open approaches, emphasizing the importance of accurate and expedient CFA access. Resuscitative endovascular balloon occlusion of the aorta may represent a feasible alternative to thoracotomy for aortic occlusion. Time to aortic occlusion will likely decrease with the advent of newer REBOA technology. The rate-limiting portion of REBOA continues to be obtaining CFA access. Therapeutic, level V.

Predictors of early stent occlusion among plastic biliary stents.

PubMed

Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K

2012-09-01

A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.

Influence of denture adhesives on occlusion and disocclusion times.

PubMed

Abdelnabi, Mohamed Hussein; Swelem, Amal Ali; Al-Dharrab, Ayman A

2016-03-01

The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (P<.001) in stability and retention and a significant decrease in duration of all occlusal parameters (OT [P=.003], DT-right [P=.003], and DT-left [P=.008]). Adhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions

PubMed Central

Choi, Sulki

2017-01-01

PURPOSE The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal thickness. PMID:29279761

Parecoxib suppresses CHOP and Foxo1 nuclear translocation, but increases GRP78 levels in a rat model of focal ischemia.

PubMed

Ye, Zhi; Wang, Na; Xia, Pingping; Wang, E; Liao, Juan; Guo, Qulian

2013-04-01

Parecoxib, a novel COX-2 inhibitor, functions as a neuroprotective agent and rescues neurons from cerebral ischemic reperfusion injury-induced apoptosis. However, the molecular mechanisms underlying parecoxib neuroprotection remain to be elucidated. There is growing evidence that endoplasmic reticulum (ER) stress plays an important role in neuronal death caused by brain ischemia. However, very little is known about the role of parecoxib in mediating pathophysiological reactions to ER stress induced by ischemic reperfusion injury. Therefore, in the present study, we investigated whether delayed administration of parecoxib attenuates brain damage via suppressing ER stress-induced cell death. Adult male Sprague-Dawley rats were administered parecoxib (10 or 30 mg kg(-1), IP) or isotonic saline twice a day starting 24 h after middle cerebral artery occlusion (MCAO) for three consecutive days. The expressions of glucose-regulated protein 78 (GRP78) and oxygen-regulated protein 150 (ORP150) and C/EBP-homologous protein (CHOP) and forkhead box protein O 1 (Foxo1) in cytoplasmic and nuclear fraction were determined by Western blotting. The levels of caspase-12 expression were checked by immunohistochemistry analysis, served as a marker for ER stress-induced apoptosis. Parecoxib significantly suppressed cerebral ischemic injury-induced nuclear translocation of CHOP and Foxo1 and attenuated the immunoreactivity of caspase-12 in ischemic penumbra. Furthermore, the protective effect of delayed administration of parecoxib was accompanied by an increased GRP78 and ORP150 expression. Therefore, our study suggested that elevation of GRP78 and ORP150, and suppression of CHOP and Foxo1 nuclear translocation may contribute to parecoxib-mediated neuroprotection during ER stress responses.

Oxaloacetate restores the long-term potentiation impaired in rat hippocampus CA1 region by 2-vessel occlusion.

PubMed

Marosi, Máté; Fuzik, János; Nagy, Dávid; Rákos, Gabriella; Kis, Zsolt; Vécsei, László; Toldi, József; Ruban-Matuzani, Angela; Teichberg, Vivian I; Farkas, Tamás

2009-02-14

Various acute brain pathological conditions are characterized by the presence of elevated glutamate concentrations in the brain interstitial fluids. It has been established that a decrease in the blood glutamate level enhances the brain-to-blood efflux of glutamate, removal of which from the brain may prevent glutamate excitotoxicity and its contribution to the long-lasting neurological deficits seen in stroke. A decrease in blood glutamate level can be achieved by exploiting the glutamate-scavenging properties of the blood-resident enzyme glutamate-oxaloacetate transaminase, which transforms glutamate into 2-ketoglutarate in the presence of the glutamate co-substrate oxaloacetate. The present study had the aim of an evaluation of the effects of the blood glutamate scavenger oxaloacetate on the impaired long-term potentiation (LTP) induced in the 2-vessel occlusion ischaemic model in rat. Transient (30-min) incomplete forebrain ischaemia was produced 72 h before LTP induction. Although the short transient brain hypoperfusion did not induce histologically identifiable injuries in the CA1 region (Fluoro-Jade B, S-100 and cresyl violet), it resulted in an impaired LTP function in the hippocampal CA1 region without damaging the basal synaptic transmission between the Schaffer collaterals and the pyramidal neurons. This impairment could be fended off in a dose-dependent manner by the intravenous administration of oxaloacetate in saline (at doses between 1.5 mmol and 0.1 mumol) immediately after the transient hypoperfusion. Our results suggest that oxaloacetate-mediated blood and brain glutamate scavenging contributes to the restoration of the LTP after its impairment by brain ischaemia.

Proinflammatory cytokines correlate with early exercise attenuating anxiety-like behavior after cerebral ischemia.

PubMed

Zhang, Qi; Zhang, Jingjun; Yan, Yuzhong; Zhang, Pengyue; Zhang, Wei; Xia, Rong

2017-11-01

Stroke may cause neuropsychiatric problems, which have negative effects on cognitive functions and behavior. Exercise plays an important role in reducing the occurrence and development of stroke, the concrete mechanism is not fully clarified. In this study, we attempted to determine whether early treadmill exercise attenuates anxiety-like behavior by regulation of inflammation after brain ischemia. We subjected adult male rats to middle cerebral artery occlusion (MCAO) for 90 min and trained rats started to run on a treadmill from postoperative day 1 to day 14. The effects of treadmill on cognitive functions, anxiety-like behavior, and immune activation were analyzed by Morris water maze test, open field test, elevated plus maze test, and enzyme-linked immunosorbent assay. Early treadmill exercise significantly improved cognitive function, alleviated anxiety-like behavior in ischemic rats model; this improvement was associated with significantly decreased activation of astrocytes and microglia cells and proinflammatory markers (platelet-activating factor [PAF], interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-α], intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]). Our results indicated that early treadmill exercise attenuated anxiety-like behavior by decreasing inflammation response, exercise conferred a great benefit of attenuating anxiety-like behavior via anti-inflammatory treatment may prove to be a novel neuroprotective strategy for stroke.

Role of fractalkine/CX3CR1 signaling pathway in the recovery of neurological function after early ischemic stroke in a rat model.

PubMed

Liu, Yan-Zhi; Wang, Chun; Wang, Qian; Lin, Yong-Zhong; Ge, Yu-Song; Li, Dong-Mei; Mao, Geng-Sheng

2017-09-01

This study aims to explore the role of fractalkine/CX3C chemokine receptor 1 (CX3CR1) signaling pathway in the recovery of neurological functioning after an early ischemic stroke in rats. After establishment of permanent middle cerebral artery occlusion (pMCAO) models, 50 rats were divided into blank, sham, model, positive control and CX3CR1 inhibitor groups. Neurological impairment, walking and grip abilities, and cortical and hippocampal infarctions were evaluated by Zea Longa scoring criterion, beam-walking assay and grip strength test, and diffusion-weighted magnetic resonance imaging. qRT-PCR and Western blotting were performed to detect mRNA and protein expressions. ELISA was conducted to measure concentration of sFractalkine (sFkn), interleukin-1β (IL-1β) and TNF-α. The recovery rate of neurological functioning impairment and reduced walking and grip abilities was faster in the positive control and CX3CR1 inhibitor groups than the model group. The model, positive control and CX3CR1 inhibitor groups showed increased mRNA and protein expression of chemokine C-X3-C motif ligand 1 (CX3CL1) and CX3CR1, concentration of sFkn, IL-1β and TNF-α, and size of cortical and cerebral infarctions while decreased expression of NGF and BDNF compared with the blank and sham groups. Compared with the model group, the mRNA and protein expression of CX3CL1 and CX3CR1, concentration of sFkn, IL-1β and TNF-α, and size of cortical and cerebral infarctions decreased while expression of NGF and BDNF increased in the positive control and CX3CR1 inhibitor groups. Thus, the study suggests that inhibition of fractalkine/CX3CR1 signaling pathway promotes the recovery of neurological functioning after the occurrence of an early ischemic stroke. Copyright © 2017 Elsevier Inc. All rights reserved.

Retinoic acid-pretreated Wharton's jelly mesenchymal stem cells in combination with triiodothyronine improve expression of neurotrophic factors in the subventricular zone of the rat ischemic brain injury.

PubMed

Sabbaghziarani, Fatemeh; Mortezaee, Keywan; Akbari, Mohammad; Kashani, Iraj Ragerdi; Soleimani, Mansooreh; Moini, Ashraf; Ataeinejad, Nahid; Zendedel, Adib; Hassanzadeh, Gholamreza

2017-02-01

Stroke is the consequence of limited blood flow to the brain with no established treatment to reduce the neurological deficits. Focusing on therapeutic protocols in targeting subventricular zone (SVZ) neurogenesis has been investigated recently. This study was designed to evaluate the effects of retinoic acid (RA)-pretreated Wharton's jelly mesenchymal stem cells (WJ-MSCs) in combination with triiodothyronine (T3) in the ischemia stroke model. Male Wistar rats were used to induce focal cerebral ischemia by middle cerebral artery occlusion (MCAO). There were seven groups of six animals: Sham, Ischemic, WJ-MSCs, RA-pretreated WJ-MSCs, T3, WJ-MSCs +T3, and RA-pretreated WJ-MSCs + T3. The treatment was performed at 24 h after ischemia, and animals were sacrificed one week later for assessments of retinoid X receptor β (RXRβ), brain-derived neurotrophic factor (BDNF), Sox2 and nestin in the SVZ. Pro-inflammatory cytokines in sera were measured at days four and seven after ischemia. RXRβ, BDNF, Sox2 and nestin had the significant expressions in gene and protein levels in the treatment groups, compared with the ischemic group, which were more vivid in the RA-pretreated WJ-MSCs + T3 (p ≤ 0.05). The same trend was also resulted for the levels of TNF-α and IL-6 at four days after ischemia (p ≤ 0.05). In conclusion, application of RA-pretreated WJ-MSCs + T3 could be beneficial in exerting better neurotrophic function probably via modulation of pro-inflammatory cytokines.

Neuroprotection by glutamate oxaloacetate transaminase in ischemic stroke: an experimental study.

PubMed

Campos, Francisco; Sobrino, Tomás; Ramos-Cabrer, Pedro; Argibay, Bárbara; Agulla, Jesús; Pérez-Mato, María; Rodríguez-González, Raquel; Brea, David; Castillo, José

2011-06-01

As ischemic stroke is associated with an excessive release of glutamate into the neuronal extracellular space, a decrease in blood glutamate levels could provide a mechanism to remove it from the brain tissue, by increasing the brain-blood gradient. In this regard, the ability of glutamate oxaloacetate transaminase (GOT) to metabolize glutamate in blood could represent a potential neuroprotective tool for ischemic stroke. This study aimed to determine the neuroprotective effects of GOT in an animal model of cerebral ischemia by means of a middle cerebral arterial occlusion (MCAO) following the Stroke Therapy Academic Industry Roundtable (STAIR) group guidelines. In this animal model, oxaloacetate-mediated GOT activation inhibited the increase of blood and cerebral glutamate after MCAO. This effect is reflected in a reduction of infarct size, smaller edema volume, and lower sensorimotor deficits with respect to controls. Magnetic resonance spectroscopy confirmed that the increase of glutamate levels in the brain parenchyma after MCAO is inhibited after oxaloacetate-mediated GOT activation. These findings show the capacity of the GOT to remove glutamate from the brain by means of blood glutamate degradation, and suggest the applicability of this enzyme as an efficient and novel neuroprotective tool against ischemic stroke.

Hemodynamic changes in a rat parietal cortex after endothelin-1-induced middle cerebral artery occlusion monitored by optical coherence tomography

NASA Astrophysics Data System (ADS)

Liu, Jian; Ma, Yushu; Dou, Shidan; Wang, Yi; La, Dongsheng; Liu, Jianghong; Ma, Zhenhe

2016-07-01

A blockage of the middle cerebral artery (MCA) on the cortical branch will seriously affect the blood supply of the cerebral cortex. Real-time monitoring of MCA hemodynamic parameters is critical for therapy and rehabilitation. Optical coherence tomography (OCT) is a powerful imaging modality that can produce not only structural images but also functional information on the tissue. We use OCT to detect hemodynamic changes after MCA branch occlusion. We injected a selected dose of endothelin-1 (ET-1) at a depth of 1 mm near the MCA and let the blood vessels follow a process first of occlusion and then of slow reperfusion as realistically as possible to simulate local cerebral ischemia. During this period, we used optical microangiography and Doppler OCT to obtain multiple hemodynamic MCA parameters. The change trend of these parameters from before to after ET-1 injection clearly reflects the dynamic regularity of the MCA. These results show the mechanism of the cerebral ischemia-reperfusion process after a transient middle cerebral artery occlusion and confirm that OCT can be used to monitor hemodynamic parameters.

Volumetric ambient occlusion for real-time rendering and games.

PubMed

Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M