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Tao M, Deng Y, Cheng A, Zhang Y, Xu M. Effects of electroacupuncture pretreatment on motor function and cerebral blood flow in MCAO model rats. JOURNAL OF ACUPUNCTURE AND TUINA SCIENCE 2022. [DOI: 10.1007/s11726-022-1308-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Gonzalez LF, Warner DS, Sheng H, Chaparro E. Endovascular middle cerebral artery embolic stroke model: a novel approach. J Neurointerv Surg 2021; 14:413. [PMID: 34140285 DOI: 10.1136/neurintsurg-2021-017370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/06/2021] [Indexed: 11/03/2022]
Abstract
A video (video 1) describing a novel murine endovascular embolic stroke model is presented. Traditional middle cerebral artery (MCA) occlusion models include a blind insertion of a monofilament string12 into the common or external carotid artery with the expectation to selectively occlude the MCA. However, significant mortality occurs due to subarachnoid hemorrhage and variability in stroke size, possibly related to the filament's malposition-for example, external carotid or proximal internal carotid artery (ICA). Additionally, while the string is in place, it occludes the entire extracranial ICA affecting also the collateral pial circulation.neurintsurg;neurintsurg-2021-017370v1/V1F1V1Video 1Our model includes tail artery access, which tolerates several procedures facilitating survival studies. This model uses autologous blood3 4 clot deployed directly into the MCA, resembling what occurs in clinical practice. Autologous thrombi could be lysed with IA/IV tissue plasminogen activator.In summary, we describe a novel model that resembles real practice, permits multiple catheterizations, results in reliable embolization under fluoroscopic guidance and allows therapeutic interventions not available with traditional models.
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Affiliation(s)
| | - David S Warner
- Department of Anesthesia, Duke University, Durham, North Carolina, USA
| | - Huaxing Sheng
- Neurosurgery, Duke University Hospital, Durham, North Carolina, USA
| | - Eduardo Chaparro
- Neurosurgery, Duke University Hospital, Durham, North Carolina, USA
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Divani AA, Farr TD, Di Napoli M, Salazar P, SantaCruz KS, Jafarli A, Jafari M, Fisher M. Transfemoral Approach to Induce Transient Middle Cerebral Artery Occlusion in Rats: The Use of Commercially Available Endovascular Wires. Neurocrit Care 2019; 32:575-585. [PMID: 31346935 DOI: 10.1007/s12028-019-00791-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Animal models of stroke play a crucial role in determining the pathophysiology of stroke progression and assessment of any new therapeutic approaches. Transient middle cerebral artery occlusion (tMCAo) in rodent models are the most common site-specific type of ischemia because of their relevance to the clinical setting. Compared with the intraluminal filament technique for inducing tMCAo, the transfemoral approach using endovascular wires is relatively a new technique METHODS: Here we present the use of commercially available wires used for neuro-endovascular surgical procedures to induce tMCAo in rats via a transfemoral approach. We used male Wistar rats in four groups to assess the effect of occlusion time (1 vs. 2 hours) and the wire type (PT2 TM 0.014″ vs. TransendTM EX, 0.014″, Boston Scientific, MA, USA). Infarct volume, edema, neurological deficits, and pro-inflammatory/anti-inflammatory blood biomarkers were used as outcome measures. RESULTS We observed a significant effect of the wire type on the infarct volume (p value = 0.0096) where infarcts were slightly larger in the PT2 wiregroups. However, the occlusion time had no significant effect on infarct volume, even though the interaction between wire-type * occlusion-time was significant (p value = 0.024). Also, the amount of edema and blood pro-inflammatory/anti-inflammatory biomarkers were not statistically different among the wire-type and occlusion-time groups. CONCLUSIONS The choice of appropriate endovascular wire should probably be the focus of the study design instead of the occlusion time when planning an experiment. The transfemoral approach using endovascular wires for inducing tMCAo in rats provides a more consistent outcome with fewer complications compared with suture filament models.
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Affiliation(s)
- Afshin A Divani
- Department of Neurology, University of Minnesota, MMC 295, 420 Delaware Street S.E., Minneapolis, MN, 55455, USA. .,Department of Neurological Surgery, University of Minnesota, Minneapolis, MN, USA. .,Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Tracy D Farr
- Faculty of Medicine and Health Sciences, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Mario Di Napoli
- Department of Neurology, San Camillo de' Lellis District General Hospital, Rieti, Italy
| | | | - Karen S SantaCruz
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
| | - Alibay Jafarli
- Department of Neurology, University of Minnesota, MMC 295, 420 Delaware Street S.E., Minneapolis, MN, 55455, USA
| | - Mostafa Jafari
- Department of Neurology, University of Minnesota, MMC 295, 420 Delaware Street S.E., Minneapolis, MN, 55455, USA
| | - Marc Fisher
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Age-Related Upregulation of Carboxyl Terminal Modulator Protein Contributes to the Decreased Brain Ischemic Tolerance in Older Rats. Mol Neurobiol 2017; 55:6145-6154. [PMID: 29250714 DOI: 10.1007/s12035-017-0826-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 12/06/2017] [Indexed: 12/31/2022]
Abstract
Stroke remains one of the leading causes of death worldwide. The underlying neuropathology for stroke is ischemic brain injury. Carboxyl terminal modulator protein (CTMP), an endogenous inhibitor of the prosurvival Akt, may increase brain ischemic injury in young animals. Aging decreases brain ischemic tolerance. We hypothesize that CTMP is increased with aging and that this increase contributes to the decreased brain ischemic tolerance. To address these hypotheses, we determined the expression of CTMP and its downstream proteins in the brain of various ages of rats (Fischer 344 and Sprague-Dawley rats). The role of CTMP in ischemic brain injury was investigated by RNA interference. Here, we showed that CTMP in the brain was increased with aging in rats. The phosphorylated/activated Akt was decreased with aging. Six- and 20-month-old rats had poorer neurological outcome than did 2-month-old rats after brain ischemia. The neurological outcome of 2-month-old rats was worsened by LY294002, an Akt inhibitor. The poor neurological outcome in 6-month-old rats was improved by silencing CTMP. CTMP was increased in ischemic penumbral brain tissues. Silencing this increase activated Akt. These results suggest that CTMP increase with aging contributes to the aging-dependent decrease of brain ischemic tolerance.
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Zhang C, Zou Y, Li K, Li C, Jiang Y, Sun J, Sun R, Wen H. Different effects of running wheel exercise and skilled reaching training on corticofugal tract plasticity in hypertensive rats with cortical infarctions. Behav Brain Res 2017; 336:166-172. [PMID: 28882693 DOI: 10.1016/j.bbr.2017.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 12/15/2022]
Abstract
The approaches that facilitate white matter plasticity may prompt functional recovery after a stroke. The effects of different exercise methods on motor recovery in stroke rats have been investigated. However, it is not clear whether their effects on axonal plasticity different. The aim of this study was to compare the effects of the forced running wheel exercise (RWE) and skilled reaching training (SRT) on axonal plasticity and motor recovery. Cortical infarctions were generated in stroke-prone renovascular hypertensive rats. The rats were randomly divided into the following three groups: the control (Con) group, the RWE group, and the SRT group. A sham group was also included. The mNSS and forelimb grip strength tests were performed on days 3, 7, 14, 21, 28, 35, and 42 after ischemia. The anterograde tract tracer biotinylated dextran amine (BDA) was injected into the rats to trace the axonal plasticity of the contralesional corticofugal tracts. Compared with the Con group, the mNSS scores in the SRT and RWE groups decreased on day 28 (P<0.05) and on days 35 and 42 (P<0.01). The grip strength in the SRT group increased relative to that in the RWE group at 42day post-ischemia (P<0.01). Both the RWE and SRT groups exhibited enhanced plasticity of the contralesional corticofugal tract axons at the level of the red nucleus (P<0.01) and the cervical enlargement (P<0.01). More contralateral corticorubral tract remodeling was observed at the red nucleus level in the SRT group than in the RWE group (P<0.001). Taken together, these results suggest that SRT may enhance axon plasticity in the corticorubral tract more effectively than the forced RWE and is associated with better motor recovery after cerebral ischemia.
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Affiliation(s)
- ChanJuan Zhang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China; Department of Rehabilitation Medicine, Guangdong Second Provincial General Hospital, 466 Xingang Middle Road, Guangzhou 510317, Guangdong Province, China
| | - Yan Zou
- Department of Radiology, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China
| | - Kui Li
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China
| | - Chao Li
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China
| | - YingPing Jiang
- Department of Rehabilitation Medicine, Guangdong Second Provincial General Hospital, 466 Xingang Middle Road, Guangzhou 510317, Guangdong Province, China
| | - Ju Sun
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China
| | - Ruifang Sun
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China
| | - HongMei Wen
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, Guangdong Province, China.
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Shi P, Sun LL, Lee YS, Tu Y. Electroacupuncture regulates the stress-injury-repair chain of events after cerebral ischemia/reperfusion injury. Neural Regen Res 2017; 12:925-930. [PMID: 28761425 PMCID: PMC5514867 DOI: 10.4103/1673-5374.208574] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Inflammation after stroke is the main cause of cerebral ischemia/reperfusion injury. Cascading events after injury can lead to cell death. Heat shock protein 70 and other endogenous injury-signaling molecules are released by damaged cells, which can lead to systemic stress reactions. Protecting the brain through repair begins with the stress-injury-repair signaling chain. This study aimed to verify whether acupuncture acts through this chain to facilitate effective treatment of ischemic stroke. Rat models of cerebral ischemia/reperfusion injury were established by Zea Longa's method, and injury sites were identified by assessing neurological function, 2,3,5-triphenyltetrazolium chloride staining, and hematoxylin-eosin staining. Electroacupuncture at acupoints Baihui (DU20) and Zusanli (ST36) was performed in the model rats with dilatational waves, delivered for 20 minutes a day at 2–100 Hz and an amplitude of 2 mA. We analyzed the blood serum from the rats and found that inflammatory cytokines affected the levels of adrenotrophin and heat shock protein 70, each of which followed a similar bimodal curve. Specifically, electroacupuncture lowered the peak levels of adrenocorticotrophic hormone and heat shock protein 70. Thus, electroacupuncture was able to inhibit excessive stress, reduce inflammation, and promote the repair of neurons, which facilitated healing of ischemic stroke.
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Affiliation(s)
- Peng Shi
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Lin-Lin Sun
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Yi-Shuo Lee
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Ya Tu
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
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Abstract
In cerebral ischemia, studies of cell death have focused primarily on neurons, but recent work indicates that ischemia also causes damage to astrocytes. Activation of astrocytes is a typical brain response to stress stimuli and is evidenced by changes in cellular function and morphology, as well as upregulation of glial fibrillary acidic protein. The tumor-suppressor transcription factor p53 has recently been implicated as a mediator of ischemia-induced neuronal death, but very little is known about its role in the activation or the death of astrocytes. The present study investigated the role of p53 in astrocyte and neuronal toxicity using in-vitro and in-vivo ischemic stroke models. We showed that p53 is activated in ischemic brains and in oxygen-glucose deprivation (OGD)-induced cell death in neurons and astrocytes. Inhibition of p53 activity using either pifithrin-α or small interference RNA interference reduced OGD-induced cell death and pifithrin-α reversed OGD-induced impairment of glutamate uptake in astrocytes, suggesting that p53 might play a key role in mediating neurotoxicity and gliotoxicity in ischemic brain injury. This study shows that p53 is activated in astrocytes during ischemia and that inhibition of the activity of this molecule prevents not only OGD-induced neuronal and astrocytic death but also astrocyte activation and impaired glutamate uptake. These findings suggest that p53 may be a valuable therapeutic target in ischemic brain injury.
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Bachour SP, Hevesi M, Bachour O, Sweis BM, Mahmoudi J, Brekke JA, Divani AA. Comparisons between Garcia, Modo, and Longa rodent stroke scales: Optimizing resource allocation in rat models of focal middle cerebral artery occlusion. J Neurol Sci 2016; 364:136-40. [PMID: 27084232 DOI: 10.1016/j.jns.2016.03.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/24/2016] [Accepted: 03/17/2016] [Indexed: 10/22/2022]
Abstract
The use of rodent stroke models allow for the understanding of stroke pathophysiology. There is currently no gold standard neurological assessment to measure deficits and recovery from stroke in rodent models. Agreement on a universal preclinical stroke scale allows for comparison of the outcomes among conducted studies. The present study aimed to compare three routinely used neurological assessments in rodent studies (i.e., Garcia, Modo, and Longa) to determine which is most effective for accurately and consistently quantifying neurological deficits in the context of focal middle cerebral artery occlusion (MCAo) in rats. Focal MCAo was induced in 22 male Wistar rats using a novel transfemoral approach. Rodents were assessed for neurological deficit pre-injury as well as 3 and 24h post-injury. Data was analyzed to determine Pearson correlation coefficients in addition to McNemar's χ(2) values between each pair of neurological assessments. All three stroke scales, Garcia, Modo, and Longa, showed statistically significant changes between the baseline and the 3-hour neurological assessments. A trend towards neurological recovery was observed in all three stroke scales between the 3 and 24-hour endpoints. The three scales were highly correlated with each other, with Garcia and Modo having the strongest correlation. Of the three pairwise analyses, the comparison between the Garcia and Longa tests demonstrated the highest McNemar's χ(2) value, indicating least marginal homogeneity between these two tests. The combination of high correlation between Garcia and Modo tests along with greatest marginal heterogeneity observed between the Garcia and Longa test lead us to recommend the use of Garcia and Longa neurological scales when researchers are hoping to capture the broadest range of neurological factors using only two stroke scales.
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Affiliation(s)
- Salam P Bachour
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; College of Biological Sciences, University of Minnesota, Minneapolis, MN, United States
| | - Mario Hevesi
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; Medical School, Twin Cities Campus, University of Minnesota, Minneapolis, MN, United States
| | - Ornina Bachour
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; Medical School, Twin Cities Campus, University of Minnesota, Minneapolis, MN, United States
| | - Brian M Sweis
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; Medical School, Twin Cities Campus, University of Minnesota, Minneapolis, MN, United States; Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Javad Mahmoudi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Julia A Brekke
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Afshin A Divani
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States; Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States.
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Exercise Training Inhibits the Nogo-A/NgR1/Rho-A Signals in the Cortical Peri-infarct Area in Hypertensive Stroke Rats. Am J Phys Med Rehabil 2016; 94:1083-94. [PMID: 26135366 DOI: 10.1097/phm.0000000000000339] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to test the hypothesis that exercise training promotes motor recovery after stroke by facilitating axonal remodeling via inhibition of the Nogo-A/NgR1 and Rho-A pathway. DESIGN A distal middle cerebral artery occlusion model was generated in stroke-prone renovascular hypertensive rats. Stroke-prone renovascular hypertensive rats were randomly divided into a control group, an exercise training group, and a sham group. Motor function was measured using the grip strength test. Axon and myelin remodeling markers, growth-associated protein 43, myelin basic protein, Tau, and amyloid precursor protein were detected by immunofluorescence. The expression of Nogo-A, NgR1, and Rho-A was demonstrated by immunofluorescence and Western blotting in the peri-infarction area at 7, 14, 28, and 52 days after distal middle cerebral artery occlusion. RESULTS Grip strength was higher in the exercise training group (P < 0.05). Exercise training increased the expression of growth-associated protein 43, myelin basic protein (at 7, 14, and 28 days), and Tau (at 7 and 14 days), and decreased the expression of axonal damage amyloid precursor protein (at 7 and 14 days), compared with the control group. The protein levels of Nogo-A (at 7 and 14 days), NgR1 (at 7, 14, and 28 days), and Rho-A (at 14 and 28 days) were reduced after exercise training. CONCLUSIONS Exercise training promotes axonal recovery, which is associated with functional improvement after cerebral infarction. Down-regulation of the Nogo-A/NgR1/Rho-A may mediate the axonal remodeling induced by exercise training.
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Gao HH, Gao LB, Wen JM. Genetic polymorphisms in the ESR1 gene and cerebral infarction risk: a meta-analysis. DNA Cell Biol 2014; 33:605-15. [PMID: 24772998 DOI: 10.1089/dna.2013.2270] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A number of studies have documented that estrogen receptor α (ESR1) may play an important role in the development and progression of cerebral infarction, but many existing studies have yielded inconclusive results. This meta-analysis was performed to evaluate the relationships between ESR1 genetic polymorphisms and cerebral infarction risk. The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before October 1, 2013, without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Seven case-control studies were included with a total of 1471 patients with cerebral infarction and 4688 healthy control subjects. Two common single-nucleotide polymorphisms (SNPs) in the ESR1 gene (rs2234693 T>C and rs9340799 A>G) were assessed. Our meta-analysis results revealed that ESR1 genetic polymorphisms might increase the risk of cerebral infarction. Subgroup analysis by SNP type indicated that both rs2234693 and rs9340799 polymorphisms in the ESR1 gene were strongly associated with an increased risk of cerebral infarction. Further subgroup analysis by ethnicity showed significant associations between ESR1 genetic polymorphisms and increased risk of cerebral infarction among both Asians and Caucasians. In the stratified subgroup analysis by gender, the results suggested that ESR1 genetic polymorphisms were associated with an increased risk of cerebral infarction in the female population. However, there were no statistically significant associations between ESR1 genetic polymorphisms and cerebral infarction risk in the male population. Meta-regression analyses also confirmed that gender might be a main source of heterogeneity. Our findings indicate that ESR1 genetic polymorphisms may contribute to the development of cerebral infarction, especially in the female population.
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Affiliation(s)
- Hong-Hua Gao
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University , Shenyang, People's Republic of China
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Meng Q, He C, Shuaib A, Wang CX. Hyperthermia worsens ischaemic brain injury through destruction of microvessels in an embolic model in rats. Int J Hyperthermia 2012; 28:24-32. [PMID: 22235782 DOI: 10.3109/02656736.2011.631963] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Basal lamina is a major part of the microvascular wall and plays a critical role in the integrity of microvasculature. The aim of this study is to determine whether hyperthermia worsens the destruction of microvascular integrity in the ischaemic injured brain. MATERIALS AND METHODS Focal cerebral ischaemia was induced by embolising a pre-formed clot into the middle cerebral artery (MCA). Rats received either normothermic or hyperthermic treatment. Neurological score and infarct size were evaluated at 24 h after the MCA occlusion. Microvascular collagen type IV and laminin were measured with fluorescence microscopy. The activities of matrix metalloproteinases (MMP-2 and MMP-9) and plasminogen activators (tPA and uPA) were determined by zymography. RESULTS Treatment with hyperthermia significantly increased infarct volume (p<0.01), cortex swelling (p<0.01), striatum swelling (p<0.05) and neurologic score (p<0.01) at 24 h after the MCA occlusion. Compared to the normothermic groups, hyperthermia significantly worsened the losses of microvascular basal lamina structure proteins, collagen type IV and laminin, at 6 h (p<0.001) and 24 h (p<0.01) after MCA occlusion. Hyperthermia increased the MMP-9 activity at 6 and 24 h after MCA occlusion compared with normothermia (p<0.05), whereas increased the MMP-2 activity at 6 h only (p<0.05). Hyperthermia also elevated uPA activity significantly at 6 and 24 h after MCA occlusion compared to normothermia (p<0.05). CONCLUSIONS These results demonstrate that hyperthermia exacerbates the destruction of microvascular integrity possibly by increasing the activities of MMP-2, MMP-9 and uPA in the ischaemic cerebral tissues.
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Affiliation(s)
- Qiang Meng
- Department of Neurology, the First People's Hospital of Yunnan Province, Kunming, PR China
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Pirzad Jahromi G, Seidi S, Sadr SS, Shabanzadeh AP, Keshavarz M, Kaka GR, Hosseini SK, Sohanaki H, Charish J. Therapeutic Effects of a Combinatorial Treatment of Simvastatin and Bone Marrow Stromal Cells on Experimental Embolic Stroke. Basic Clin Pharmacol Toxicol 2012; 110:487-93. [DOI: 10.1111/j.1742-7843.2011.00848.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 12/05/2011] [Indexed: 12/29/2022]
Affiliation(s)
- G. Pirzad Jahromi
- Department of Physiology & Electrophysiology research Centre; School of Medicine; Tehran University of Medical Sciences; Tehran; Iran
| | - S. Seidi
- Department of Physiology & Electrophysiology research Centre; School of Medicine; Tehran University of Medical Sciences; Tehran; Iran
| | - S. S. Sadr
- Department of Physiology & Electrophysiology research Centre; School of Medicine; Tehran University of Medical Sciences; Tehran; Iran
| | | | - M. Keshavarz
- Department of Physiology & Electrophysiology research Centre; School of Medicine; Tehran University of Medical Sciences; Tehran; Iran
| | - G. R. Kaka
- Neuroscience Research Center of Baqiyatallah University of Medical Sciences
| | - S. K. Hosseini
- Tissue Bank & Preparation Research Center; Tehran University of Medical Sciences; Tehran; Iran
| | - H. Sohanaki
- Department of Physiology & Electrophysiology research Centre; School of Medicine; Tehran University of Medical Sciences; Tehran; Iran
| | - J. Charish
- Department of Genetics and Development; University Health Network; Toronto Western Research Institute; University of Toronto; Toronto; Canada
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Zhao H, Zhang Q, Xue Y, Chen X, Haun RS. Effects of hyperbaric oxygen on the expression of claudins after cerebral ischemia-reperfusion in rats. Exp Brain Res 2011; 212:109-17. [PMID: 21626096 DOI: 10.1007/s00221-011-2702-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 04/15/2011] [Indexed: 01/09/2023]
Abstract
The malfunction of tight junctions (TJs) between endothelial cells in the blood brain barrier (BBB) is the pathophysiological basis for cerebral ischemia-reperfusion (IR) injury. Claudins, major molecular elements of the TJs, play a key role in the paracellular permeability of the BBB. Although several studies have demonstrated the impact of hyperbaric oxygenation (HBO) on boosting oxygen supply and reducing infarct size, its effect and underlying mechanism on the integrity of the BBB is unknown. To study the function of HBO on claudins and the permeability of the BBB, we replicated the animal model of local cerebral IR. Using Evans blue dye, permeability of the BBB was examined. Transmission electron microscopy (TEM), immunohistochemistry, western blot, and gelatin zymography were used to detect the integrity of the BBB, the expression of claudin-1 and claudin-5, and the activity of matrix metalloproteinases (MMPs) in brain microvessel endothelium. Our data indicate that compared with the sham-operated group, IR increased permeability of the BBB to Evans blue dye (P < 0.01), peaking at 4 h. The BBB ultrastructure was disrupted and the expression of claudin-5 and claudin-1 decreased (P < 0.01) in the 4 and 72 h IR group, respectively. Increased claudin-5 and claudin-1 expression and decreased permeability of the BBB were observed in the HBO + IR group (P < 0.01) via the suppression of MMP-2 and MMP-9, respectively. Our study provides direct evidence that HBO decreases the permeability of the BBB by reducing the enzymatic activity of MMPs and augmenting the expression of claudins at different stages in cerebral IR injury.
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Affiliation(s)
- Hong Zhao
- Department of Experimental Center of Functional Subjects, College of Basic Medicine, China Medical University, Shenyang 110001, China.
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Lapergue B, Deroide N, Pocard M, Michel JB, Meilhac O, Bonnin P. Transcranial duplex sonography for monitoring circle of Willis artery occlusion in a rat embolic stroke model. J Neurosci Methods 2011; 197:289-96. [DOI: 10.1016/j.jneumeth.2011.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 02/16/2011] [Accepted: 02/18/2011] [Indexed: 11/28/2022]
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Yusubalieva GM, Baklaushev VP, Gurina OI, Tsitrin EB, Chekhonin VP. Immunochemical Analysis of Glial Fibrillary Acidic Protein as a Tool to Assess Astroglial Reaction in Experimental C6 Glioma. Bull Exp Biol Med 2010; 149:125-30. [DOI: 10.1007/s10517-010-0890-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nategh M, Shaveisi K, Shabanzadeh AP, Sadr SS, Parviz M, Ghabaei M. Systemic hyperthermia masks the neuroprotective effects of MK-801, but not rosiglitazone in brain ischaemia. Basic Clin Pharmacol Toxicol 2010; 107:724-9. [PMID: 20406202 DOI: 10.1111/j.1742-7843.2010.00570.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The use of neuroprotective agents has been under investigation for the treatment of ischaemic brain stroke. In this study, we examined the effects of rosiglitazone and MK-801, two potential neuroprotectants, on thromboembloic focal stroke in hyperthermic rats. The animals were assigned into groups of rosiglitazone, MK-801 and control, all under both normothermic and hyperthermic conditions. A focal ischaemia was induced by injection of preformed clot into the origin of the middle cerebral artery. The animals were assessed by measuring infarct size and brain oedema and also evaluating neurological deficit and seizure activity. Rosiglitazone improved infarct volume and neurological deficit in both normo- (36%) and hyperthermic (63%) animals; but MK-801 only improved normothermic animals. Our results do not support the use of MK-801 in hyperthermic conditions of brain stroke but suggest that rosiglitazone may preserve its efficiency even in hyperthermia.
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Affiliation(s)
- Mohsen Nategh
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Design, synthesis and biological evaluation of new ionone derivatives as potential neuroprotective agents in cerebral ischemia. Eur J Med Chem 2010; 45:1964-71. [PMID: 20170988 DOI: 10.1016/j.ejmech.2010.01.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 01/15/2010] [Accepted: 01/18/2010] [Indexed: 12/31/2022]
Abstract
A new series of ionone derived allylic alcohols have been evaluated for anti-ischemic activity. Out of them, 12f and 13b decreased infarct volume to 23.98+/-4.7 mm3 and 93.98+/-24.8 mm3 as compared to ischemic group.
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18
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Dose dependence and therapeutic window for the neuroprotective effects of curcumin in thromboembolic model of rat. Behav Brain Res 2008; 193:289-97. [DOI: 10.1016/j.bbr.2008.06.012] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 06/06/2008] [Accepted: 06/09/2008] [Indexed: 11/22/2022]
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Nagel S, Papadakis M, Hoyte L, Buchan AM. Therapeutic hypothermia in experimental models of focal and global cerebral ischemia and intracerebral hemorrhage. Expert Rev Neurother 2008; 8:1255-68. [PMID: 18671669 DOI: 10.1586/14737175.8.8.1255] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Experimental evidence shows that therapeutic hypothermia (TH) protects the brain from cerebral injury in multiple ways. In different models of focal and global cerebral ischemia, mild-to-moderate hypothermia reduces mortality and neuronal injury and improves neurological outcome. In models of experimental intracerebral hemorrhage (ICH), TH reduces edema formation but does not show consistent benefi cial effects on functional outcome parameters. However, the number of studies of hypothermia on ICH is still limited. TH is most effective when applied before or during the ischemic event, and its neuroprotective properties vary according to species, strains and the model of ischemia used. Intrinsic changes in body and brain temperature frequently occur in experimental models of focal and global cerebral ischemia, and may have infl uenced studies on other neuroprotectants. This might be one explanation for the failure of a large amount of translational clinical neuroprotective trials. Hypothermia is the only neuroprotective therapeutic agent for cerebral ischemia that has successfully managed the transfer from bench to bedside, and it is an approved therapy for patients after cardiac arrest and children with hypoxic-ischemic encephalopathy. However, the implementation of hypothermia in the treatment of stroke patients is still far from routine clinical practice. In this article, the authors describe the development of TH in different models of focal and global cerebral ischemia, point out why hypothermia is so efficient in experimental cerebral ischemia, explain why temperature regulation is essential for further neuroprotective studies and discuss why TH for acute ischemic stroke still remains a promising but controversial therapeutic option.
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Affiliation(s)
- Simon Nagel
- Acute Stroke Programme, Nuffield Department of Clinical Medicine, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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Dohare P, Garg P, sharma U, Jagannathan NR, Ray M. Neuroprotective efficacy and therapeutic window of curcuma oil: in rat embolic stroke model. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2008; 8:55. [PMID: 18826584 PMCID: PMC2573880 DOI: 10.1186/1472-6882-8-55] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 09/30/2008] [Indexed: 01/08/2023]
Abstract
BACKGROUND Among the naturally occurring compounds, turmeric from the dried rhizome of the plant Curcuma longa has long been used extensively as a condiment and a household remedy all over Southeast Asia. Turmeric contains essential oil, yellow pigments (curcuminoids), starch and oleoresin. The present study was designed for investigating the neuroprotective efficacy and the time window for effective therapeutic use of Curcuma oil (C. oil). METHOD In the present study, the effect of post ischemic treatment of C.oil after ischemia induced by occlusion of the middle cerebral artery in the rat was observed. C.oil (500 mg/kg body wt) was given 4 hrs post ischemia. The significant effect on lesion size as visualized by using diffusion-weighted magnetic resonance imaging and neuroscore was still evident when treatment was started 4 hours after insult. Animals were assessed for behavioral deficit scores after 5 and 24 hours of ischemia. Subsequently, the rats were sacrificed for evaluation of infarct and edema volumes and other parameters. RESULTS C.oil ameliorated the ischemia induced neurological functional deficits and the infarct and edema volumes measured after 5 and 24 hrs of ischemia. After 24 hrs, immunohistochemical and Western blot analysis demonstrated that the expression of iNOS, cytochrome c and Bax/Bcl-2 were altered after the insult, and antagonized by treatment with C.oil. C.oil significantly reduced nitrosative stress, tended to correct the decreased mitochondrial membrane potential, and also affected caspase-3 activation finally apoptosis. CONCLUSION Here we demonstrated that iNOS-derived NO produced during ischemic injury was crucial for the up-regulation of ischemic injury targets. C.oil down-regulates these targets this coincided with an increased survival rate of neurons.
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Shabanzadeh AP, Shuaib A, Wang CX. Reduction of ischemic brain injury in rats with normothermic and hyperthermic conditions. J Neurosurg 2008; 109:522-9. [DOI: 10.3171/jns/2008/109/9/0522] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Statins have been used for induction of ischemic tolerance after cerebral ischemia. The authors have previously shown that simvastatin is protective after ischemic cerebral injury in normothermic conditions. In this study they further examined whether treatment with simvastatin can reduce ischemic brain injury in a hyperthermic condition.
Methods
Focal ischemic brain injury was induced by embolizing a preformed clot into the middle cerebral artery in rats. The authors initially examined whether treatment with simvastatin could reduce ischemic brain injury without or with hyperthermia. The infarct volume, edema, and neurological deficits were examined. They then studied whether simvastatin could reduce the perfusion deficits, damage to the blood–brain barrier (BBB), and degeneration of neurons in the ischemic injured brain.
Results
Simvastatin significantly reduced the infarct volume in both normothermic and hyperthermic conditions, compared with appropriate controls. Concomitantly, this treatment also significantly reduced neurological deficits and brain edema. Administration of simvastatin significantly decreased perfusion deficits, BBB permeability, and degenerated neurons.
Conclusions
These studies suggest that simvastatin is an effective agent for ischemic brain injury not only in normothermic but also in hyperthermic conditions, which may be through the decrease of BBB permeability, degenerated neurons, and perfusion deficits.
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Affiliation(s)
- Alireza P. Shabanzadeh
- 1Stroke Research Laboratory, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Ashfaq Shuaib
- 1Stroke Research Laboratory, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Chen Xu Wang
- 1Stroke Research Laboratory, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- 2Laboratory of Central Illinois Neuroscience Foundation, Bloomington; and
- 3Department of Biological Science, Illinois State University, Normal, Illinois
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Dohare P, Varma S, Ray M. Curcuma oil modulates the nitric oxide system response to cerebral ischemia/reperfusion injury. Nitric Oxide 2008; 19:1-11. [PMID: 18485279 DOI: 10.1016/j.niox.2008.04.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 04/01/2008] [Accepted: 04/12/2008] [Indexed: 10/22/2022]
Abstract
The antioxidant activity of C.oil in cerebral stroke has been reported earlier. We have attempted here to clarify the mechanisms underlying the neuroprotection against experimental cerebral ischemia by Curcuma oil (C.oil), isolated from the rhizomes of Curcuma longa. C.oil (250 mg/kg i.p.) was given 30 min before focal ischemia in rats caused by occlusion of the middle cerebral artery (1h of occlusion, 24h of reflow). Ischemia, leads to elevation in [Ca(2+)] this sets into motion a cascades of ischemic injury which was attenuated by C.oil. C.oil reduced post-ischemic brain neutrophil infiltration in the ischemic area, controlled tissue NOx levels and the neuronal levels of nitric oxide, peroxynitrite and reactive oxygen species when measured after 24h of reflow. Double immunofluorescence staining analysis and Western immunoblot analysis with C.oil treatment showed that the expression of nitric oxide synthase (NOS) isoforms were decreased significantly compared to the untreated ischemia group. Ischemia is associated with increased in TUNEL (TdT-mediated dUTP nick-end labeling) positive cells in brain sections indicating DNA fragmentation. The C.oil treated group showed a significant decrease in numbers of apoptotic cells compared to the untreated ischemia group, as seen in the flowcytometric analysis of the neurons. Results of immunohistochemistry and Western immunoblot indicate that C.oil suppressed the elevated protein level of Bax, and aided mitochondrial translocation and activation of Bcl-2 by altered mitochondrial membrane potential. It also inhibits the cytosolic release of apoptogenic molecules like cytochrome c, inhibits the activation of caspase-3 and the expression of p53 ultimately inhibiting apoptosis. Our observations suggest that high levels of NO generated by NOS isoforms are partially responsible for exacerbating the neuronal damage induced by MCAo by intraluminal filament.
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Affiliation(s)
- Preeti Dohare
- Division of Pharmacology, Central Drug Research Institute, P.O. Box No. 173, Chattar Manzil Palace, Lucknow, UP 226001, India
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Aldandashi S, Noor R, Wang CX, Uddin G, Shuaib A. Combination treatment with dipyridamole, aspirin, and tPA in an embolic model of stroke in rats. Exp Neurol 2007; 205:563-8. [PMID: 17466978 DOI: 10.1016/j.expneurol.2007.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 03/05/2007] [Accepted: 03/17/2007] [Indexed: 10/23/2022]
Abstract
Antithrombotic therapy has been shown to be effective in preventing secondary strokes. Inhibition of platelet function may reduce formation of thrombi thereby reducing the incidence of stroke. However, stronger inhibition of platelets is correlated with increased risk of bleeding events. The purpose of this study was to test the protective effects of combination therapy with dipyridamole and acetylsalicylic acid (ASA) in comparison to ASA alone, and whether such combination treatment may produce any added benefits when tissue plasminogen activator (tPA) treatment is also used. The study was divided into three parts. In part A, effect of antiplatelets on infarct volume was assessed. In part B, perfusion deficits were measured. In part C, efficacy of antiplatelet therapy in combination with tPA was assessed. In part A, dipyridamole and aspirin treatment significantly reduced infarct volume (P<0.05). In part B, treatment with dipyridamole significantly reduced the perfusion deficits as compared to control (P<0.05). In part C, dipyridamole plus tPA or dipyridamole and aspirin plus tPA significantly decreased infarct volume as compared to tPA alone (P<0.05). The present study suggests that there is significant protection with dipyridamole as both infarct volume and perfusion deficits are significantly reduced. Dipyridamole with tPA also significantly reduced infarct volume as compared to tPA alone. Our data suggests that higher doses of antithrombotic therapy with dipyridamole offer best neuroprotection.
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Affiliation(s)
- Samer Aldandashi
- Stroke Research Laboratory, University of Alberta, 533 HMRC, Edmonton, Alberta, Canada T6G 2S2
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Kelly MA, Shuaib A, Todd KG. Matrix metalloproteinase activation and blood–brain barrier breakdown following thrombolysis. Exp Neurol 2006; 200:38-49. [PMID: 16624294 DOI: 10.1016/j.expneurol.2006.01.032] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 01/09/2006] [Accepted: 01/12/2006] [Indexed: 11/22/2022]
Abstract
Thrombolysis with tissue plasminogen activator (tPA) is the only pharmacotherapy available for cerebral ischemia. However, the use of tPA can increase the risk of hemorrhage due to blood-brain barrier (BBB) breakdown. Recent evidence suggests that increased activation of matrix metalloproteinases (MMPs) may be involved in this breakdown. This study examines the temporal profile of MMP-2 and -9 following tPA administration to ischemic rats. Male Sprague-Dawley rats were randomly assigned to one of four groups (Sham-tPA; Sham-Saline; Ischemia-tPA; Ischemia-Saline; group n = 6, total N = 120). Focal embolic ischemia was induced by middle cerebral artery occlusion through injection of an autologous clot. One hour post-surgery, tPA (10 mg/kg) or saline was delivered intravenously and animals were euthanized at 3, 6, 12, or 24 h after onset of ischemia. Infarct volume was measured by TTC staining; BBB components examined immunohistochemically; and MMP activation measured by gelatin zymography. Our results show that tPA significantly reduced infarct volumes (overall infarct volume-Sham-tPA: 5.80 +/- 4.55 [mean +/- SE]; Sham-Saline: 5.00 +/- 4.23; Ischemia-tPA: 186.1 +/- 73.45; Ischemia-Saline: 284.8 +/- 88.74; all P < 0.05). Treatment with tPA was also associated with the activation of MMP-9 at 6, 12, and 24 h following ischemia. No temporal changes were observed in MMP-2 activation, although tPA administration increased its activity compared to saline treatment. Analyses of immunohistochemistry showed that destruction of components of the BBB followed MMP-9 activation. Thus, increased MMP-9 activation may, in part, be responsible for the increases in hemorrhagic transformation reported with use of tPA. Our study is the first to demonstrate the temporal profile of MMP activation following thrombolysis with tPA in a model of thrombotic focal cerebral ischemia.
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Affiliation(s)
- Melissa A Kelly
- Center for Neuroscience, University of Alberta, Edmonton, AB, Canada
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Wang CX, Yang T, Shuaib A. Clot Fragments Formed from Original Thrombus Obstruct Downstream Arteries in the Ischemic Injured Brain. Microcirculation 2006; 13:229-36. [PMID: 16627365 DOI: 10.1080/10739680600556936] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Embolic occlusion of the middle cerebral artery (MCA) leads to distal perfusion deficits as the vessel is recanalized. However, the mechanism for the perfusion deficits is not fully understood. The authors examined whether distal movement of fragments formed from the original thrombus contributes to the perfusion deficits. METHODS In the first series, they studied whether the reduction in perfusion deficits is due to the dissolution of the original clots embolized or due to collateral perfusion. In the second series, they studied whether fragments formed from the original clots move to distal arterial system. In the third series, they studied whether plasminogen activator plays a role in the thrombolysis following ischemia. RESULTS Occlusion of MCA permanently resulted in large perfusion deficits in the ipsilateral hemisphere, and these perfusion deficits did not change significantly after the occlusion. In contrast, perfusion deficits reduced significantly in a model of transient MCA occlusion. The numbers of fragments formed from the original clots increased gradually after the MCA occlusion in the ischemic injured brain. In addition, expression of urokinase plasminogen activator was also upregulated. CONCLUSION The present study thus reveals the mechanisms of the downstream arterial occlusion following the dissolution of original thrombus.
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Affiliation(s)
- Chen Xu Wang
- Stroke Research Laboratory, University of Alberta, Edmonton, Alberta, Canada
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Wang CX, Yang T, Noor R, Shuaib A. Role of MC-1 alone and in combination with tissue plasminogen activator in focal ischemic brain injury in rats. J Neurosurg 2005; 103:165-9. [PMID: 16121987 DOI: 10.3171/jns.2005.103.1.0165] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Pyridoxal-5-phosphate (PLP), the biologically active form of pyridoxine, can rescue neurons from death in vitro and in vivo. In the present project, the authors have studied whether MC-1, an analog of PLP, alone or in combination with the thrombolytic agent tissue plasminogen activator (tPA), can protect the brains of rats injured by ischemia. METHODS Ischemic brain injury was induced in rats by injecting a preformed blood clot in the middle cerebral artery (MCA). Neurological deficits and infarct volumes caused by the embolus were measured to evaluate the effects of MC-1 on the ischemic injury. Systemic blood pressure and local brain blood flow were also monitored. Administration of different doses of MC-1 1 hour after embolization significantly reduced the infarct volume and improved functional recovery. Injection of MC-1 (40 mg/kg) at 3 or 6 hours after embolization also reduced the volume of the infarct significantly and improved functional recovery. Combined treatment with MC-1 and tPA was also neuroprotective, although it was not superior to treatment involving either MC-1 or tPA alone. Treatment with MC-1 did not result in significant changes in either systemic blood pressure or local blood flow in the ischemic brain. CONCLUSIONS These data support the hypothesis that in the focal embolic stroke model in rats MC-1 is a neuroprotective agent. The neuroprotection this compound provides still exists when MC-1 administration is delayed up to 6 hours after ischemic injury.
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Affiliation(s)
- Chen Xu Wang
- Stroke Research Laboratory, University of Alberta, Edmonton, Canada
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Shabanzadeh AP, Shuaib A, Wang CX. Simvastatin reduced ischemic brain injury and perfusion deficits in an embolic model of stroke. Brain Res 2005; 1042:1-5. [PMID: 15823246 DOI: 10.1016/j.brainres.2005.01.105] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 01/24/2005] [Accepted: 01/25/2005] [Indexed: 11/28/2022]
Abstract
Simvastatin is cholesterol lowering agent and also a modulator of cytokine in the nervous system. The functional significance and neuroprotectiove mechanism of simvastatins in ischemic brain injury is controversial. The purpose of study is to evaluate the effect of simvastatin on ischemic brain injury and to investigate the perfusion capability of brain microvessels in the ischemic injury. This study included two series of experiments. In the first series, we studied if simvastatin is neuroprotective in an embolic model of stroke. The treatments began 2 weeks before middle cerebral artery (MCA) occlusion. Infarct volume was measured at 48 h post stroke. Neurological deficits were assessed at 2 h, 24 h and 48 h post stroke. Results showed that infarct volume in rats which received saline and simvastatin was 32.5 +/- 9.3% (mean +/- SD) and 18.7 +/- 6.5%, respectively. The infarct volume in the simvastatin group was significantly smaller than in the controls (P < 0.002). Treatment with simvastatin also improved neurological deficits and reduced brain edema significantly (P < 0.05). In the second series, we studied if simvastatin can improve microvascular reperfusions after ischemia. Perfusion deficits were detected at 8 h post stroke using Evens blue dye. Neurological deficits were assessed at 2 h and 8 h post stroke. Results showed that perfusion deficit in saline and simvastatin-treated groups were 58.7 +/- 8.7% and 23.4 +/- 7.5%, respectively. The perfusion deficit in simvastatin-treated group was decreased 61% (P < 0.01). These studies thus suggest that simvastatin is a protective agent in ischemic brain injury and this protective effect may be partially due to its action in the improvement of microvascular reperfusion.
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Affiliation(s)
- Alireza P Shabanzadeh
- Stroke Research Laboratory, 533 HMRC, University of Alberta, Edmonton, Canada ABT6G 2S2
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Noor R, Wang CX, Shuaib A. Effects of hyperthermia on infarct volume in focal embolic model of cerebral ischemia in rats. Neurosci Lett 2003; 349:130-2. [PMID: 12946569 DOI: 10.1016/s0304-3940(03)00802-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hyperthermia worsens outcome of stroke in patients and also in animal models. In the present study, we tested the effects of hyperthermia in a focal embolic model of cerebral ischemia in rats. Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery. Hyperthermia significantly increased the brain infarct volume as compared to the normothermic controls measured at 48 h following the ischemic insult. Neurological deficits were also significantly elevated in the animals undergoing hyperthermic treatment. In addition, hyperthermia also significantly increased mortality. Our data thus show that hyperthermia exacerbates neuronal injury in the focal embolic model of cerebral ischemia in rats.
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Affiliation(s)
- Raza Noor
- Department of Neurology, University of Alberta Hospital, Edmonton, Alta 6G 2S2, Canada
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Ardehali MR, Rondouin G. Microsurgical intraluminal middle cerebral artery occlusion model in rodents. Acta Neurol Scand 2003; 107:267-75. [PMID: 12675700 DOI: 10.1034/j.1600-0404.2003.00010.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Focal brain ischemia induced in rodents by occlusion of the middle cerebral artery (MCA) is a widely used paradigm of human brain infarct. The objective of this study is to compare the effectiveness and reproducibility of MCA filament occlusion model in rats and mice. MATERIALS AND METHODS A total of 140 rodents (69 rats and 71 mice) were operated. Ninety-five animals were subjected to MCA occlusion; the surgical procedure consisted of introducing an uncoated surgical nylon monofilament into the cervical common carotid artery (CCA) and advancing it intracranially to permanently block blood flow into the right MCA. Forty-five sham-occluded rodents underwent CCA ligation. Surgical success, autopsy confirmed success and mortality rate were evaluated. Effective MCA occlusion was confirmed by the evidence of motor neurological deficit, by histopathology, immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR). IHC was performed in a randomly selected number of animals to detect the protein product of monocyte chemoattractant protein-1. The brain tissue in mice was examined by RT-PCR for the expression of macrophage inflammatory protein-1 alpha mRNA. RESULTS Surgical success rate was 89% in the rats, significantly lower than that in the mice (100%, P < 0.05). Autopsy confirmed success rate in the rats, 60%, was also significantly different from that in the mice (92.5%, P < 0.001). The operative mortality rate was 4.3% in the rats and 15% in the mice. CONCLUSION The present study demonstrates that the microsurgical filament occlusion of the MCA can be more successfully performed in mice. The lower rate of success in rats seems to be as a result of the architecture of the carotid canal in this animal. No previous reports, using a considerable number of animals, have compared the feasibility of intraluminal model in the rat with that in the mouse.
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Affiliation(s)
- M R Ardehali
- National Center of Scientific Research, CNRS, UPR 9023, Montpellier, France.
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Wang CX, Yang T, Shuaib A. Effects of minocycline alone and in combination with mild hypothermia in embolic stroke. Brain Res 2003; 963:327-9. [PMID: 12560140 DOI: 10.1016/s0006-8993(02)04045-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Inflammatory reactions occurring in the brain after ischemia may contribute to secondary damage. In the present study effects of minocycline, an anti-inflammatory agent, alone or in combination with mild hypothermia, on focal embolic brain ischemia have been examined. Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA). Infarct volume was measured at 48 h after the injury. Administration of minocycline alone or minocycline plus mild hypothermia reduced infarct volume significantly. However, mild hypothermia in combination with minocycline did not show any additive effect. These results suggest that minocycline is beneficial in focal ischemic brain injury, and the lack of the enhanced neuroprotection may be due to the brief exposure to hypothermia.
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Affiliation(s)
- Chen Xu Wang
- Stroke Research Laboratory, 533 HMRC, University of Alberta, T6G 2S2, Edmonton, Canada.
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Shuaib A, Xu Wang C, Yang T, Noor R. Effects of nonpeptide V(1) vasopressin receptor antagonist SR-49059 on infarction volume and recovery of function in a focal embolic stroke model. Stroke 2002; 33:3033-7. [PMID: 12468809 DOI: 10.1161/01.str.0000039405.31526.06] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral edema develops very early after the onset of focal cerebral ischemia and may be a major factor in early disability after an acute ischemic stroke. There have been very limited studies on the usefulness of antiedemic agents as neuroprotective agents in the setting of focal cerebral ischemia. We tested the neuroprotective effects of a new potent nonpeptide vasopressin receptor V(1) antagonist, SR-49059, in a focal embolic stroke model in rats. METHODS Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA). Infarction volume was measured at 48 hours after the MCA occlusion. Neurological deficits, ischemic brain edema, seizure activity, and mortality and hemorrhage rates were also documented. RESULTS Treatment with SR-49059 (2 mg/kg), initiated immediately after MCA occlusion, significantly reduced infarction volume (P<0.05) measured at 48 hours after the arterial occlusion. In animals in which the treatment was delayed for 1 hour after MCA occlusion, infarction volume was also reduced significantly (P<0.05). Infarction volume in the rats that received the drug at 3 or 6 hours after MCA occlusion was not different from that in the vehicle-treated group. Treatment with SR-49059, when started early after the arterial occlusion, also reduced neurological deficits and ischemic brain edema. Injection of drug at a higher dose (30 mg/kg) also reduced infarction volume and improved functional recovery but was not superior to the lower dose (2 mg/kg) when the drug was administrated at 1 hour after MCA occlusion. CONCLUSIONS Our data show that the selective vasopressin receptor antagonist SR-49059 is a potent neuroprotective agent when used early after onset of arterial occlusion in an embolic focal ischemia model in rats. Further studies are needed in stroke models to better understand its neuroprotective properties when used alone or in combination with thrombolysis.
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Affiliation(s)
- Ashfaq Shuaib
- Stroke Research Laboratory, Department of Medicine (Neurology), University of Alberta, Edmonton, Alberta, Canada.
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Wang CX, Yang T, Noor R, Shuaib A. Delayed minocycline but not delayed mild hypothermia protects against embolic stroke. BMC Neurol 2002; 2:2. [PMID: 11960560 PMCID: PMC107740 DOI: 10.1186/1471-2377-2-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2002] [Accepted: 04/18/2002] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Inflammatory reactions occurring in the brain after ischemia may contribute to secondary damage. In the present study, effects of minocycline, an anti-inflammatory agent, alone or in combination with mild hypothermia on focal embolic cerebral ischemia have been examined. METHODS Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA). Infarction volume was measured at 48 h after the injury. Mortality was also recorded. RESULTS Delayed administration of minocycline alone or delayed minocycline plus delayed mild hypothermia reduced the infarction volume significantly. However, delayed mild hypothermia alone was not protective and delayed mild hypothermia in combination with minocycline did not show any additive effect. CONCLUSIONS These results suggest that minocycline is beneficial in focal ischemic brain injury, and the lack of the enhanced neuroprotection may be due to the brief exposure to hypothermia.
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Affiliation(s)
- Chen Xu Wang
- Stroke Research Laboratory, Department of Medicine, University of Alberta, Canada
| | - Tao Yang
- Stroke Research Laboratory, Department of Medicine, University of Alberta, Canada
| | - Raza Noor
- Stroke Research Laboratory, Department of Medicine, University of Alberta, Canada
| | - Ashfaq Shuaib
- Stroke Research Laboratory, Department of Medicine, University of Alberta, Canada
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Wang CX, Yang T, Shuaib A. An improved version of embolic model of brain ischemic injury in the rat. J Neurosci Methods 2001; 109:147-51. [PMID: 11513949 DOI: 10.1016/s0165-0270(01)00408-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A modified version of focal embolic stroke model has been developed in rats. Ischemic injury was induced by injection of a pre-formed clot into the middle cerebral artery (MCA). In the first series of experiments, the model was validated. Embolizing a pre-formed clot resulted in an infarction in the territory irrigated by the MCA. At 48 h after embolization, 2,3,5-triphenyltetrazolium chloride (TTC) staining showed that infarction volume was 42.1+/-15.6% (mean+/-S.D.) when 5 microl clot was injected (n=8) and 28.4+/-8.6% in the animals received 3.5 microl clot (n=8). The infarction volume between these two groups showed a significant difference (P<0.05). In the second series of experiments, the natural dissolution of the clot in the MCA was studied. Five min after embolization (n=6), clots were observed in the MCA of all the animals. Clots in the MCA were seen in 68 and 29% of the animals at 1 and 3 h, respectively, after embolization. These results suggest that the procedure described here produces a reliable and reproducible ischemic injury. The clots injected were dissolved in the MCA in relatively short period of time. The model shows a close similarity to thromboembolic stroke in human, and it provides a useful tool to investigate mechanisms and test thrombolytic agents in ischemic brain injury.
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Affiliation(s)
- C X Wang
- The Department of Medicine, Division of Neurology, 533 HMRC, Neurology Laboratory, University of Alberta, AB T6G 2S2, Edmonton, Canada.
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