Hiromi Kawai

Okayama University, Okayama, Okayama, Japan

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Publications (16)35.37 Total impact

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    ABSTRACT: Recent studies show that modern In vivo optical imaging can detect matrix metallopeptidase (MMP) activation in the ischemic brain. In this study, we analyze the protective effects of bone marrow stromal cells (BMSCs) and edaravone (EDA) against tissue plasminogen activator (tPA) risk in the ischemic brain with In vivo optical fluorescence MMP imaging. At 48 hours after 60 minutes of transient middle cerebral artery occlusion (tMCAO) with tPA, C57BL/6J mice were subjected to motor function analysis, In vivo and ex vivo optical imaging for MMP activation, gelatin zymography, and double immunofluorescent analyses with or without intravenous BMSC transplantation and the intravenous free radical scavenger EDA. In vivo fluorescent signals for MMP were detected over the heads of living mice 48 hours after tMCAO; the strongest were in the tPA group, which were reduced by BMSC or EDA treatment. These In vivo data were confirmed by ex vivo fluorescence imaging. While massive intracerebral hemorrhages were observed in the ischemic hemispheres of the tPA group, only slight hemorrhages were found in the tPA/BMSC, tPA/EDA, and EDA groups. Gelatin zymography showed the strongest MMP-9 activation in the tPA group after tMCAO, which was reduced by BMSC or EDA treatment. The present study provides a correlation between In vivo optical imaging of MMP activation and the improvement of ischemic brain damage caused by tPA after tMCAO and treated by BMSC and EDA.
    Neurological Research 08/2013; · 1.18 Impact Factor
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    ABSTRACT: OBJECTIVES: Obesity is the major risk factor for metabolic syndrome and atherosclerotic cardiocerebrovascular diseases. METHODS: We studied effects of amlodipine, atorvastatin, and their combination on carotid arteriosclerotic processes in a metabolic syndrome model of Zucker fatty rats. Zucker fatty rats were treated with vehicle, amlodipine, atorvastatin, or combination amlodipine plus atorvastatin for 28 days. RESULTS: Compared with the single treatment with amlodipine or atorvastatin, the combination of amlodipine plus atorvastatin treatment prevented arteriosclerotic processes, and induced a strong recovery of Sirtuin1 (Sirt1) expression and a marked reduction in p53, p21, and monocyte chemoattractant protein-1 (MCP-1). DISCUSSION: As Sirt1 is a longevity gene that prevents endothelial atherosclerotic processes, and p53, p21, and MCP-1 play pivotal roles in the initiation and development of atherosclerosis, these data suggest a strong synergistic benefit of combination therapy with amlodipine and atorvastatin for preventing atherosclerotic processes, and potentially reducing the clinical risk of cerebrovascular events in metabolic obesity patients.
    Neurological Research 12/2012; · 1.18 Impact Factor
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    ABSTRACT: OBJECTIVES: To examine and compare the pleiotropic effects on oxidative stress and metabolic signalling pathways of atorvastatin and pitavastatin in mouse model of Alzheimer's disease (AD). METHODS: We gave the transgenic (Tg) mice either atorvastatin or pitavastatin from 5-20 months (M) of age, and performed immunohistological analysis [4-hydroxy-2-nonenal (4-HNE)-positive, advanced glycation end products (AGEs), low-density lipoprotein receptor (LDL-R)-positive neurons, apolipoprotein E (ApoE)-positive senile plaque (SP), and insulin receptor (IR)-positive endothelium], and biochemistry analysis (adiponectin and leptin). RESULTS: The numbers of 4-HNE- and AGE-positive neurons and the sum of ApoE-positive SP size progressively increased with age in amyloid precursor protein (APP)-Tg mice, while the amount of IRpositive endothelium and the number of LDL-R-positive neurons decreased. Adiponectin and leptin serum levels were lower in APP-Tg mice than in non-Tg mice. Treatment with statins reduced the number of AGEpositive neurons from as early as 10 M, preserved the numbers of 4-HNE- and LDL-R-positive neurons and the amount of IR-positive endothelium at 15 M, and reduced the sum of ApoE-positive SP size and adiponectin serum level at 20 M. DISCUSSION: Atorvastatin and pitavastatin reduced the level of oxidative stress, as revealed by the presence of 4-HNE and AGE, in AD mouse brains, and that treatment with statins improves insulin signaling and LDLR/ApoE systems. The beneficial effects of these statins may be associated with direct pleiotropic effects on AD mouse brains, indirect effects through improving the serum adiponectin/leptin balance, or both.
    Neurological Research 12/2012; · 1.18 Impact Factor
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    ABSTRACT: Structural and functional abnormalities in the neurovascular unit (NVU) have been recently observed in Alzheimer's disease (AD). Statins, which are used clinically for reducing cholesterol levels, can also exert beneficial vascular actions, improve behavioral memory and reduce senile plaque (SP). Thus, we examined cognitive function, the serum level of lipids, senile plaque (SP), and the protective effects of statins on NVU disturbances in a mouse AD model. Amyloid precursor protein (APP) transgenic (Tg) mice were used as a model of AD. Atorvastatin (30mg/kg/day, p.o.) or pitavastatin (3mg/kg/day, p.o.) were administered from 5 to 20months of age. These 2 statins improved behavioral memory and reduced the numbers of SP at 15 and 20M without affecting serum lipid levels. There was a reduction in immunopositive staining for N-acetyl glucosamine oligomer (NAGO) in the endothelium and in collagen IV in the APP vehicle (APP/Ve) group, with collagen IV staining most weakest near SP. There was also an increase in intensity and numbers of glial fibrillary acidic protein (GFAP) positive astrocytes, particularly around the SP, where MMP-9 was more strongly labeled. Double immunofluorescent analysis showed that astrocytic endfeet had detached from the capillary endothelium in the APP/Ve group. Overall, these data suggest that statins may have therapeutic potential for AD by protecting NVU.
    Journal of the neurological sciences 07/2012; 322(1-2):59-63. · 2.32 Impact Factor
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    ABSTRACT: Cerebral infarction is a major cause of death or decreasing activities of daily living. This study aimed to investigate the efficacy of commonly used antiplatelet drugs on stroke and motor and cognitive functions in relation to oxidative stress markers and insulin-like growth factor 1 receptor (IGF-1R). Stroke-prone spontaneously hypertensive rats were treated with vehicle, aspirin, clopidogrel, and cilostazol from 8 to 10 weeks of age. Physiological parameters, regional cerebral blood flow, and serum lipids were examined. Motor and cognitive functions were evaluated weekly by the Rotorod and water maze task. Spontaneous infarct volume, oxidative stress markers for lipid, protein, and DNA at the ischemic boundary zone of spontaneous infarction, and the IGF-1R-positive cell ratio in the hippocampus were immunohistochemically examined in brain sections. IGF-1Rβ expression in the hippocampus was assessed by Western blotting. The antiplatelet drugs, cilostazol and clopidogrel, reduced the spontaneous infarct volume more than aspirin. Only cilostazol improved motor and cognitive functions with a significant increase (P<0.05) in the memory-related IGF-1R-positive ratio and IGF-1Rβ expression in the hippocampus. Cilostazol reduced the 4 oxidative stress markers in affected neurons in stroke-prone spontaneously hypertensive rats regardless of blood pressure, regional cerebral blood flow, or serum lipid levels. The present results suggest that a possible pleiotropic effect of cilostazol resulted in the reduction of spontaneous infarct volume and preservation of motor and spatial cognitive functions. The increase of IGF-1R-positive cells in the hippocampal CA1 region could partly explain the preservation of spatial cognitive function in stroke-prone spontaneously hypertensive rats.
    Stroke 04/2012; 43(6):1639-46. · 6.16 Impact Factor
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    ABSTRACT: Changes in expression of neurorepair and neuroregenerative factors were examined after transient cerebral ischemia in relation to the effects of tissue plasminogen activator (tPA) and the free radical scavenger edaravone. Physiological saline or edaravone was injected twice during 90 min of transient middle cerebral artery occlusion (tMCAO) in rats, followed by the same saline or tPA at reperfusion. Sizes of the infarct and protein factors relating to neurorepair and neuroregeneration were examined at 4d after tMCAO. The protein factors examined were: a chondroitin sulfate proteoglycan neurocan, semaphorin type 3A (Sema3A), a myelin-associated glycoprotein receptor (Nogo receptor, Nogo-R), a synaptic regenerative factor (growth associated protein-43, GAP43), and a chemotropic factor netrin receptor (deleted in colorectal cancer, DCC). Two groups treated by edaravone only or edaravone plus tPA showed a reduction in infarct volume compared to the two groups treated by vehicle only or vehicle plus tPA. Immunohistochemistry and western blot analyses indicated that protein expression of neurocan, Sema3A, Nogo-R, GAP43, and DCC was decreased with tPA, but recovered with edaravone. Additive edaravone prevented the reductions of these five proteins induced by tPA. The present study demonstrates for the first time that exogenous tPA reduced protein factors involved in inhibiting and promoting axonal growth, but that edaravone ameliorated such damage in brain repair after acute ischemia.
    Brain research 02/2012; 1436:168-77. · 2.46 Impact Factor
  • Koji Abe, Toru Yamashita, Hiromi Kawai
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    ABSTRACT: Stroke is a major neurologic disorder. Induced pluripotent stem (iPS) cells can be produced from basically any part of patients, with high reproduction ability and pluripotency to differentiate into various types of cells, suggesting that iPS cells can provide a hopeful therapy for cell transplantation. However, transplantation of iPS cells into ischemic brain has not been reported. In this study, we showed that the iPS cells fate in a mouse model of transient middle cerebral artery occlusion (MCAO). Undifferentiated iPS cells (5×10(5)) were transplanted into ipsilateral striatum and cortex at 24 h after 30 mins of transient MCAO. Behavioral and histologic analyses were performed at 28 day after the cell transplantation. To our surprise, the transplanted iPS cells expanded and formed much larger tumors in mice postischemic brain than in sham-operated brain. The clinical recovery of the MCAO+iPS group was delayed as compared with the MCAO+PBS (phosphate-buffered saline) group. iPS cells formed tridermal teratoma, but could supply a great number of Dcx-positive neuroblasts and a few mature neurons in the ischemic lesion. iPS cells have a promising potential to provide neural cells after ischemic brain injury, if tumorigenesis is properly controlled.
    Rinshō shinkeigaku = Clinical neurology. 01/2012; 52(11):1143-6.
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    ABSTRACT: Bone marrow (BM) cells from amyotrophic lateral sclerosis (ALS) patients show significantly reduced expression of several neurotrophic factors. Monotherapy with either wild-type (WT) BM transplantation (BMT) or granulocyte colony-stimulating factor (GCSF) has only a small clinical therapeutic effect in an ALS mouse model, due to the phenomenon of neuroprotection. In this study, we investigated the clinical benefits of combination therapy using BMT with WT BM cells, plus GCSF after disease onset in ALS mice [transgenic mice expressing human Cu/Zn superoxide dismutase (SOD1) bearing a G93A mutation]. Combined treatment with BMT and GCSF delayed disease progression and prolonged the survival of G93A mice, whereas BMT or GCSF treatment alone did not. Histological study of the ventral horns of lumbar cords from G93A mice treated with BMT and GCSF showed a reduction in motor neuron loss coupled with induced neuronal precursor cell proliferation, increased expression of neurotrophic factors (glial cell line-derived neurotrophic factor, brain-derived neurotrophic factor, vascular endothelial growth factor and angiogenin), and neovascularization compared with controls (vehicle only). Compared with G93A microglial cells, most BM-derived WT cells differentiated into microglial cells and strongly expressed neurotrophic factors, combined BMT and GCSF treatment led to the replacement of G93A microglial cells with BM-derived WT cells. These results indicate combined treatment with BMT and GCSF has potential neuroprotective and angiogenic effects in ALS mice, induced by the replacement of G93A microglial cells with BM-derived WT cells. Furthermore, this is the first report showing the effects of combined BMT and GCSF treatment on blood vessels in ALS.
    Cell Medicine. 01/2011; 2(2):69-83.
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    ABSTRACT: Ischemic stroke is a major neurologic disorder and a leading cause of disability and death in the world. We compared neuroprotective effects of single or combination therapy of amlodipine (AM) and atorvastatin (AT) in such a metabolic syndrome model Zucker rat. The animals were pretreated with vehicle, AM, AT, or the combination of AM plus AT for 28days, and physical and serum parameters were analyzed, then 90min of transient middle cerebral artery occlusion (tMCAO), was performed followed by immunohistochemical analyses at 24h. Without affecting serum levels of lipids, adiponectin, and leptin, the combination therapy of AM plus AT ameliorated the post-ischemic brain weight increase. The single treatment with AM or AT itself exerted neuroprotective effects with reducing inductions of MMP-9 and AT2R, as well as with preserving collagen IV, and the combination therapy of AM plus AT showed a further synergistic benefit against acute ischemic neural damages. Single AT was more protective on these 3 molecules than single AM at this time point of 24h after tMCAO. Thus, the combination therapy with AM plus AT extended the neuroprotectives effect of single treatment with AM or AT on a part of neurovascular unit and a hypertension-related receptor.
    Brain research 01/2011; 1382:308-14. · 2.46 Impact Factor
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    ABSTRACT: One of the therapeutics for acute cerebral ischemia is tissue plasminogen activator (t-PA). Using t-PA after 3 hour time window increases the chances of hemorrhage, involving multiple mechanisms. In order to show possible mechanisms of t-PA toxicity and the effect of the free radical scavenger edaravone, we administered vehicle, plasmin, and t-PA into intact rat cortex, and edaravone intravenously. Plasmin and t-PA damaged rat brain with the most prominent injury in t-PA group on 4-HNE, HEL, and 8-OHdG immunostainings. Such brain damage was strongly decreased in t-PA plus edaravone group. For the neurovascular unit immunostainings, occludin and collagen IV expression was decreased in single plasmin or t-PA group, which was recovered in t-PA plus edaravone group. In contrast, matrix metalloproteinase-9 intensity was the strongest in t-PA group, less in plasmin, and was the least prominent in t-PA plus edaravone group. In vitro data showed a strong damage to tight junctions for occludin and claudin 5 in both administration groups, while there were no changes for endothelial (NAGO) and perivascular (GFAP) stainings. Such damage to tight junctions was recovered in t-PA plus edaravone group with similar recovery in Sodium-Fluorescein permeability assay. Administration of t-PA caused oxidative stress damage to lipids, proteins and DNA, and led to disruption of outer parts of neurovascular unit, greater than the effect in plasmin administration. Additive edaravone ameliorated such an oxidative damage by t-PA with protecting outer layers of blood-brain barrier (in vivo) and tight junctions (in vitro).
    Current neurovascular research 11/2010; 7(4):319-29. · 3.23 Impact Factor
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    ABSTRACT: Induced pluripotent stem (iPS) cells may provide cures for various neurological diseases. However, undifferentiated iPS cells have high tumorigenicity, and evaluation of the cells fates, especially in pathologic condition model, is needed. In this study, we demonstrated the effect of ischemic condition to undifferentiated iPS cells fates in a mouse model of transient middle cerebral artery occlusion (MCAO). Undifferentiated iPS cells were characterized with immunofluorescent staining. The iPS cells (5 × 10⁵) were injected into ipsilateral striatum and cortex after 24 h of MCAO. Histological analysis was performed from 3 to 28 days after cell transplantation. iPS cells in ischemic brain formed teratoma with higher probability (p < 0.05) and larger volume (p < 0.01) compared with those in intact brain. Among the four transcriptional factors to produce iPS cells, c-Myc, Oct3/4, and Sox2 strongly expressed in iPS-derived tumors in ischemic brain (p < 0.01). Additionally, expression of matrix metalloproteinase-9 (MMP-9) and phosphorylated vascular endothelial growth factor receptor2 (phospho-VEGFR2) were significantly increased in iPS-derived tumors in the ischemic brain (p < 0.05). These results suggest that the transcriptional factors might increase expression of MMP-9 and activate VEGFR2, promoting teratoma formation in the ischemic brain. We strongly propose that the safety of iPS cells should be evaluated not only in normal condition, but also in a pathologic, disease model.
    Cell Transplantation 11/2010; 20(6):883-91. · 4.42 Impact Factor
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    ABSTRACT: One of the therapeutics for acute cerebral ischemia is tissue plasminogen activator (t-PA). Using t-PA after 3 hour time window increases the chances of hemorrhage, involving multiple mechanisms. In order to show possible mechanisms of t-PA toxicity and the effect of the free radical scavenger edaravone, we administered vehicle, plasmin, and t-PA into intact rat cortex, and edaravone intravenously. Plasmin and t-PA damaged rat brain with the most prominent injury in t-PA group on 4-HNE, HEL, and 8-OHdG immunostainings. Such brain damage was strongly decreased in t-PA plus edaravone group. For the neurovascular unit immunostainings, occludin and collagen IV expression was decreased in single plasmin or t-PA group, which was recovered in t-PA plus edaravone group. In contrast, matrix metalloproteinase-9 intensity was the strongest in t-PA group, less in plasmin, and was the least prominent in t-PA plus edaravone group. In vitro data showed a strong damage to tight junctions for occludin and claudin 5 in both administration groups, while there were no changes for endothelial (NAGO) and perivascular (GFAP) stainings. Such damage to tight junctions was recovered in t-PA plus edaravone group with similar recovery in Sodium-Fluorescein permeability assay. Administration of t-PA caused oxidative stress damage to lipids, proteins and DNA, and led to disruption of outer parts of neurovascular unit, greater than the effect in plasmin administration. Additive edaravone ameliorated such an oxidative damage by t-PA with protecting outer layers of blood-brain barrier (in vivo) and tight junctions (in vitro).
    Current Neurovascular Research 10/2010; 7(4):319-329. · 2.84 Impact Factor
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    ABSTRACT: Stroke is a major neurologic disorder and a leading cause of death in the world. We compared neuroprotective effects of single or combination therapy of amlodipine (AM) and atorvastatin (AT) in such a metabolic syndrome model Zucker rat after 90 min of transient middle cerebral artery occlusion (tMCAO). The animals were pretreated with vehicle, AM, AT, or the combination of AM plus AT for 28 days, and at 24h of tMCAO, infarct volume and immunohistochemical analyses were performed. The combination of AM plus AT treatment decreased the infarct volume stronger than each single treatment with AM or AT. The numbers of positive cells of oxidative stress markers such as 8-hydroxy-2'-deoxyguanosin (8-OHdG), 4-hydroxy-2-nonenal (4-HNE), and advanced end glycation products (AGE) and inflammation markers such as tumor necrosis factor alpha (TNF-α) and monocyte chemoattractant protein-1(MCP-1) decreased dramatically in the combination-treated group compared with single AM- or AT-treated group. The present study showed that single AM or AT treatment showed neuroprotective effects both with antioxidative and anti-inflammatory mechanisms, but combination therapy of AM plus AT presented a further synergistic benefit in acute ischemic neural damages.
    Brain research 10/2010; 1368:317-23. · 2.46 Impact Factor
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    ABSTRACT: Stroke is a major neurologic disorder. Induced pluripotent stem (iPS) cells can be produced from basically any part of patients, with high reproduction ability and pluripotency to differentiate into various types of cells, suggesting that iPS cells can provide a hopeful therapy for cell transplantation. However, transplantation of iPS cells into ischemic brain has not been reported. In this study, we showed that the iPS cells fate in a mouse model of transient middle cerebral artery occlusion (MCAO). Undifferentiated iPS cells (5 x 10(5)) were transplanted into ipsilateral striatum and cortex at 24 h after 30 mins of transient MCAO. Behavioral and histologic analyses were performed at 28 day after the cell transplantation. To our surprise, the transplanted iPS cells expanded and formed much larger tumors in mice postischemic brain than in sham-operated brain. The clinical recovery of the MCAO+iPS group was delayed as compared with the MCAO+PBS (phosphate-buffered saline) group. iPS cells formed tridermal teratoma, but could supply a great number of Dcx-positive neuroblasts and a few mature neurons in the ischemic lesion. iPS cells have a promising potential to provide neural cells after ischemic brain injury, if tumorigenesis is properly controlled.
    Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism 03/2010; 30(8):1487-93. · 5.46 Impact Factor
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    ABSTRACT: Obesity is the major risk factor for metabolic syndrome and atherosclerotic cardiocerebrovascular diseases and induces insulin resistance characterized by a dysfunction of insulin to activate insulin receptor /insulin receptor substrate 1(IRS-1)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Zucker fatty rats (8 weeks) were treated with vehicle (0.5 % methyl cellulose in physiological saline, p.o.), amlodipine (3 mg/kg/day, p.o.), atorvastatin (10 mg/kg/day, p.o.), or the combination of amlodipine plus atorvastatin (3 + 10 mg/kg/day, p.o.) for 28 days, and anti-insulin-like growth factor 1 (IGF-1)/IRS-1/PI3K/Akt pathways were evaluated. Our present immunohistochemical study first demonstrated that a combination of amlodipine plus atorvastatin treatment prevented an arteriosclerotic process compared to the single treatment with amlodipine or atorvastatin with strong recoveries of pTyr IRS-1, pPI3K, and pAkt expressions and with remarkable restraints of IGF-1 and pSer IRS-1. As a result, combination therapy with amlodipine plus atorvastatin showed a strong synergistic effect to prevent atherosclerotic processes. The present study newly suggests a synergistic benefit of combination therapy with amlodipine plus atorvastatin for strong prevention of atherosclerotic processes, which could reduce the clinical risk of cerebrovascular events for obesity patients.
    Translational Stroke Research. 3(4).
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    ABSTRACT: To investigate the effects of amlodipine in combination with atorvastatin on carotid atherosclerotic changes in metabolic syndrome, 8-week-old Zucker fatty rats were treated with vehicle, amlodipine, atorvastatin, or amlodipine in combination with atorvastatin for 28 days. Histological studies of common carotid arteries showed that lipid deposition determined by Sudan III staining was significantly reduced in rats treated with amlodipine or atorvastatin alone and was further reduced by amlodipine in combination with atorvastatin. Immunohistochemical studies of the pro-inflammatory cytokine tumor necrosis factor (TNF)-α, the arterial calcification initiator bone morphogenetic protein (BMP) 2, the angiogenic factor Notch1, and the smooth muscle cell marker α-smooth muscle actin (SMA) showed that the high expression of all four protein in vehicle-treated rats was greatly decreased by amlodipine, atorvastatin, or amlodipine in combination with atorvastatin, in ascending order. Double immunostaining showed marked colocalization of TNF-α with bone morphogenetic protein 2 and Notch1 with α-SMA in the vehicle group, which was greatly reduced by amlodipine plus atorvastatin. These data suggest that combination therapy may be more effective in preventing atherosclerotic processes and subsequent carotid vascular events than administrating amlodipine or atorvastatin alone in metabolic syndrome.
    Translational Stroke Research. 3(4).