OBJECTIVE To evaluate the effects of Tong-Qiao-Huo-Xue decoction(TQHXD)on the bloodbrain barrier(BBB)permeability and the expressions of related proteins on the rats;and to analyse the constituents in the cerebrospina...OBJECTIVE To evaluate the effects of Tong-Qiao-Huo-Xue decoction(TQHXD)on the bloodbrain barrier(BBB)permeability and the expressions of related proteins on the rats;and to analyse the constituents in the cerebrospinal fluid on the rats with cerebral ischemic injury.METHODS Cerebral ischemia rats were induced by middle cerebral artery occlusion(MCAO).Adult male sprague-dawley(SD)rats were randomly divided into seven groups:sham-group;model group;nimodipine(NMP)-treated group and nao mai tai(NMT)-treated group were set as positive drug control groups;TQHXD-treated group(3,6 and 12g·kg-1body weight);The neurological function of rats was estimated by neurological defect scoring after the 1,7and 15 dafter administration.Histological structure of the brain in rats were observed by hematoxylin and eosin(H&E)staining.Ultramicrostructural features of hippocampus neurons and the opening of tight junction(TJ)of BBB in rats were observed by transmission electron microscope(TEM).Western blotting was performed to detect the expression of ZO-1,occludin,claudin-5,AQP-4 and MMP-9 in BBB after cerebral ischemia injury.Component analysis experiments:adult male SD rats were randomly divided into four groups:Distilled water was administered intragastrically sham-operated rats;Distilled water was administered intragastrically model rats by MCAO;TQHXD was administered intragatrically to rats in sham-operated group;TQHXD was administered intragestrically to rats in model group by MCAO.GC and HPLC was used to detect three compounds,namely,muscone,ligustilide and hydroxysafflor yellow A,in rats cerebrospinal fluid(CSF)after oral administration of TQHXD.Finally,samples of cerebrospinal fluid of rats in each group were compared with single medicine so as to explicit the three compounds come from which herb.RESULTS TQHXD significantly reduced the neurological defect scores.Histological examination indicated that dense neuropil and largely surviving neurons had been seen in TQHXD-treated rats.TEM observation revealed that TQHXD could significantly inhibit the damage of hippocampal neurons and reduce the opening of TJ.The decreased protein expression levels of claudin-5,occludin,ZO-1 and the increased protein expression levels of AQP-4 and MMP-9in cerebral ischemia tissue were significantly prevented by treatment of TQHXD.Analysis of experimental results showed that muscone,ligustilide and hydroxysafflor yellow A could penetrate the BBB into the CSF,and the content of the model group was lower than that of sham group after intragastric administration of TQHXD.CONCLUSION These results demonstrated that TQHXD may act as a potential neuroprotective agent against BBB damage for cerebral ischemia through protecting of hippocampus neurons,reducing the opening of TJ and decreasing the permeability of BBB by up-regulating ZO-1,occludin,claudin-5 expressions,down-regulating AQP-4 and MMP-9 expressions.The effect of TQHXD on the decrease of the opening of TJ also reduced the content of muscone,ligustilide and hydroxysafflor yellow A in cerebrospinal fluid.展开更多
OBJECTIVE Scalp mechanical stimulation, like combing, is one of the useful methods to keep brain health, which was historically recorded in traditional Chinese medicine thousand years ago. For the brain care, it is co...OBJECTIVE Scalp mechanical stimulation, like combing, is one of the useful methods to keep brain health, which was historically recorded in traditional Chinese medicine thousand years ago. For the brain care, it is considered to promote cerebrovascular circulation to prevent alopecia,headache, neurasthenia, insomnia, memory deficits. However, few study was reported on its effect and how the scalp mechanical stimulation works on vascular functions. Therefore, in this study, we try to illustrate the effect of combing on the cerebrovascular. METHODS In vivo, the anesthetized mice have been used to observe the effects of scalp mechanical stimulation. Infrared thermal imaging has been used to measure the skin temperature;vasodilation has been evaluated by retro-orbital injection of FITC-dextran 150 ku;the permeability of Blood-Brain Barrier(BBB) was analyzed by confocal microscopy of FITC-dextran 40 ku extravasation and a spectrofluorometric assay of Even Blue extravasation.RESLUTS We found that scalp mechanical stimulation rather than on the back can maintain the body temperature, especially raise the temperature in the ears. Accordingly, a moderate vasodilatation of auricles′ capillaries(≤ 8 μm) was observed, the phenomenon of which did not occur combing on the back. Furthermore, the permeability of BBB was promoted by the assays of small molecular extravasation. In addition, in vivo imaging, the small molecular of FITC-dextran(40 ku) was found to transport far away from the blood vessels into the brain parenchyma with the lapse of time. CONCLUSION Scalp mechanical stimulation can work on vasodilatation of auricles and promotion of BBB under a biological condition. Combing, as a daily behavior, simple but may yield novel insights into neuroprotection.展开更多
OBJECTIVE To investigate the role of chemokine-like factor 1(CKLF1),a novel C-C chemokine,on brain-blood barrier(BBB)integrity in rat focal cerebral ischemia and reperfusion model.METHODS Antibodies against CKLF1 was ...OBJECTIVE To investigate the role of chemokine-like factor 1(CKLF1),a novel C-C chemokine,on brain-blood barrier(BBB)integrity in rat focal cerebral ischemia and reperfusion model.METHODS Antibodies against CKLF1 was applied to the rightcerebral ventricle immediately after transient middle cerebral artery occlusion.Brain water content,Evans blue leakage and the expression of aquaporin-4(AQP-4),matrix metalloproteinase-9(MMP-9),zonula occludens-1(ZO-1)and occludin were measured.RESULTS After treatment with antiCKLF1 antibody,brain water content and Evans blue leakage in ipsilateral hemisphere were decreased in a dose-dependent manner at 24 h after reperfusion,but not changed in contralateral hemisphere.Anti-CKLF1 antibody reduced the expression of AQP-4 and MMP-9,and upregulated the expression of ZO-1 and Occludin.These results suggest that CKLF1 is involved in BBB disruption after reperfusion.CONCLUSION Inhibition of CKLF1 protects against cerebral ischemia by maintaining BBB integrity,possibly via inhibiting the expression of AQP-4 and MMP-9,and increasing the expression of tight junction protein.展开更多
The integrity and function dysfunction of the blood brain barrier(BBB)is considered to be an early event in the pathogenesis of a variety of neurological diseases in old patients and dysfunction of BBB could be induce...The integrity and function dysfunction of the blood brain barrier(BBB)is considered to be an early event in the pathogenesis of a variety of neurological diseases in old patients and dysfunction of BBB could be induced bycommon stress that old people often face,such as sepsis during which lipopolysaccharide(LPS)is released into circulation and BBB is damaged.Since decreased melatonin level had been shown in the serum and brain of old people and mice,we aim to investigate whether supplement with melatonin could alleviate LPSinduced BBB damage in old mice.Mice(24-28 months old)received one week melatonin(10 mg·kg-1·d-1,intraperitoneally,ip)or saline before challenge with LPS(1 mg·kg-1,ip).Evan′s blue(EB)and immunoglobulin G(Ig G)leakage were used to assess the BBB permeability.Immunofluoresence and Western blotting were used to detect the protein expression and distribution.Our results showed that LPS significantly increased BBB permeability in old mice accompanied by tight junction protein occludin and claudin-5 degradation,inhibition of AMP-activated protein kinase(AMPK)activation and increase of gp91phox protein expression.Interestingly,one week of melatonin treatment significantly decreased LPS-induced BBB hyperpermeability,activated AMPK and inhibited gp91phox expression upregualtion.Moreover,activation of AMPK by metformin significantly inhibited LPS-induced gp91phox expression upregualtion in endothelial cells.Taken together,our findings demonstrate that melatonin alleviates LPS-impaired integrity of BBB by activation of AMPK and inhibition of gp91phox expression in old mice.展开更多
The purpose of this study was to develop a quantitative structure–property relationship(QSPR) model based on the enhanced replacement method(ERM) and support vector machine(SVM) to predict the blood-to-brain barrier ...The purpose of this study was to develop a quantitative structure–property relationship(QSPR) model based on the enhanced replacement method(ERM) and support vector machine(SVM) to predict the blood-to-brain barrier partitioning behavior(log BB) of various drugs and organic compounds. Different molecular descriptors were calculated using a dragon package to represent the molecular structures of the compounds studied. The enhanced replacement method(ERM) was used to select the variables and construct the SVM model. The correlation coefficient, R^2, between experimental results and predicted log BB was 0.878 and 0.986, respectively. The results obtained demonstrated that, for all compounds, the log BB values estimated by SVM agreed with the experimental data, demonstrating that SVM is an effective method for model development, and can be used as a powerful chemometric tool in QSPR studies.展开更多
OBJECTIVE Tissue plasminogen activator(tPA) is the only approved pharmaco.logical therapy for acute brain ischaemia;however,a major limitation of tPA is the haemorrhagic trans.formation that follows tPA treatment.Here...OBJECTIVE Tissue plasminogen activator(tPA) is the only approved pharmaco.logical therapy for acute brain ischaemia;however,a major limitation of tPA is the haemorrhagic trans.formation that follows tPA treatment.Here,we determined whether nicotinamide mononucleotide(NMN),a key intermediate of nicotinamide adenine dinucleotide biosynthesis,affects tPA-induced haemorrhagic transformation.METHODS Middle cerebral artery occlusion(MCAO) was achieved in CD1 mice by introducing a filament to the left MCA for 5 h.When the filament was removed for reperfusion,tPA was infused via the tail vein.A single dose of NMN was injected i.p.(300 mg·kg^(-1)).Mice were killed at 24 h post ischaemia,and their brains were evaluated for brain infarction,oedema,haemoglobin content,apoptosis,neuroinflammation,blood-brain barrier(BBB) permeability,the expression of tight junction proteins(TJPs) and the activity/expression of MMPs.RESULTS In the mice infused with tPA at 5 h post ischaemia,there were significant increases in mortality,brain infarction,brain oedema,brain haemoglobin level,neural apoptosis,Iba-1 staining(microglia activation) and myeloperoxidase staining(neutrophil infiltration).All these tPA-induced alterations were significantly prevented by NMN administration.Mechanistically,the delayed tPA treatment increased BBB permeability by downregulating TJPs,including claudin-1,occludin and zonula occludens-1,and enhancing the activities and protein expression of MMP9 and MMP2.Similarly,NMN administration partly blocked these tPAinduced molecular changes.CONCLUSION Our results demonstrate that NMN ameliorates tPAinduced haemorrhagic transformation in brain ischaemia by maintaining the integrity of the BBB.展开更多
Suppression of excessive inflammation can ameliorate blood brain barrier （BBB） injury, which shows therapeutic potential for clinical treatment of brain injury induced by stroke superimposed on systemic inflammatory...Suppression of excessive inflammation can ameliorate blood brain barrier （BBB） injury, which shows therapeutic potential for clinical treatment of brain injury induced by stroke superimposed on systemic inflammatory diseases. In this study, we investigated whether and how clematichinenoside （AR）, an anti-inflammatory triter- pene saponin, protects brain injury from stroke superimposed on systemic inflammation. Lipopolysaccharide （LPS） was intraperitoneally injected immediately after middle cerebral artery occlusion （MCAO） in rats. Rat microvessel endothelial cells （rBMECs） were exposed to hypoxia/reoxygenation （H/R） coexisting with LPS. The results re- vealed that AR suppressed the excessive inflammation, restored BBB dysfunction, alleviated brain edema, de- lessened neurological dysfunction, and decreased infarct rate. Further study demon- creased neutrophil infiltration, inducible nitric oxide synthase （iNOS） , strated that the expression of nucleus nuclear factor kappa B （NF-KB）, intercellular adhesion molecule-1 （ ICAM-1 ）, tumor necrosis factor-α （TNF-α） and interlukin-1β （ IL-1β） were suppressed by AR via zinc finger protein A20. Besides, AR increased in vitro BBB integrity through A20. In con- clusion, AR alleviated cerebral inflammatory injury through A20-NF-KB signal pathway, offering an alternative medication for stroke associated with systemic inflammatory diseases.展开更多
Astrocytes are implicated in the pathological changes of Alzheimer's disease. Our previous studies have demonstrated that estrogen deprivation and oxidative stress act synergistically to accelerate the progress of...Astrocytes are implicated in the pathological changes of Alzheimer's disease. Our previous studies have demonstrated that estrogen deprivation and oxidative stress act synergistically to accelerate the progress of Alzheimer's disease. Long-term D-galactose injection combined with ovariectomy may serve as a rodent model for Alzheimer's disease. To address the potential contribution of astroglia to the Alzheimer's disease pathogenesis, we investigated pathological and biochemical alterations of astrocytes under this animal model. Ovadectomized rats injected with D-galactose for 2 weeks showed extensive localization of glial fibrillary acidic protein immunoreactive astrocytes and slightly elevated glutathione levels in the hippocampus without significant impairments in the water maze test and deficits of the cholinergic analyses, compared to the saline-injected rats. Ovariectomized rats injected with D-galactose for 6 weeks, however, exhibited degeneration of astrocytes and decreased glutathione levels in the hippocampus, accompanied with severe dysfunction of behavioral test and deficiency of cholinergic terminals. Electron microscopy further confirmed the pathological changes of astrocytes, especially in the aggregated area of synapse and brain microvessels. Consistent with degeneration of perivascular astrocytic endfeet, analysis of the horseradish peroxidase demonstrated an impairment of the blood-brain barrier permeability. These findings indicate that biochemical and pathological alterations of astrocytes may partially contribute to exacerbating neuronal deficits in the course of Alzheimer's disease. Restoring neuroprotective potential of astrocytes may be a useful therapeutic target for Alzheimer's disease and other neurodegenerative diseases.展开更多
基金The project supported by National Natural Science Foundation of China(81374005)″Twelfth Five Year″National Science and Technology Support Program(2012BAI26B03)
文摘OBJECTIVE To evaluate the effects of Tong-Qiao-Huo-Xue decoction(TQHXD)on the bloodbrain barrier(BBB)permeability and the expressions of related proteins on the rats;and to analyse the constituents in the cerebrospinal fluid on the rats with cerebral ischemic injury.METHODS Cerebral ischemia rats were induced by middle cerebral artery occlusion(MCAO).Adult male sprague-dawley(SD)rats were randomly divided into seven groups:sham-group;model group;nimodipine(NMP)-treated group and nao mai tai(NMT)-treated group were set as positive drug control groups;TQHXD-treated group(3,6 and 12g·kg-1body weight);The neurological function of rats was estimated by neurological defect scoring after the 1,7and 15 dafter administration.Histological structure of the brain in rats were observed by hematoxylin and eosin(H&E)staining.Ultramicrostructural features of hippocampus neurons and the opening of tight junction(TJ)of BBB in rats were observed by transmission electron microscope(TEM).Western blotting was performed to detect the expression of ZO-1,occludin,claudin-5,AQP-4 and MMP-9 in BBB after cerebral ischemia injury.Component analysis experiments:adult male SD rats were randomly divided into four groups:Distilled water was administered intragastrically sham-operated rats;Distilled water was administered intragastrically model rats by MCAO;TQHXD was administered intragatrically to rats in sham-operated group;TQHXD was administered intragestrically to rats in model group by MCAO.GC and HPLC was used to detect three compounds,namely,muscone,ligustilide and hydroxysafflor yellow A,in rats cerebrospinal fluid(CSF)after oral administration of TQHXD.Finally,samples of cerebrospinal fluid of rats in each group were compared with single medicine so as to explicit the three compounds come from which herb.RESULTS TQHXD significantly reduced the neurological defect scores.Histological examination indicated that dense neuropil and largely surviving neurons had been seen in TQHXD-treated rats.TEM observation revealed that TQHXD could significantly inhibit the damage of hippocampal neurons and reduce the opening of TJ.The decreased protein expression levels of claudin-5,occludin,ZO-1 and the increased protein expression levels of AQP-4 and MMP-9in cerebral ischemia tissue were significantly prevented by treatment of TQHXD.Analysis of experimental results showed that muscone,ligustilide and hydroxysafflor yellow A could penetrate the BBB into the CSF,and the content of the model group was lower than that of sham group after intragastric administration of TQHXD.CONCLUSION These results demonstrated that TQHXD may act as a potential neuroprotective agent against BBB damage for cerebral ischemia through protecting of hippocampus neurons,reducing the opening of TJ and decreasing the permeability of BBB by up-regulating ZO-1,occludin,claudin-5 expressions,down-regulating AQP-4 and MMP-9 expressions.The effect of TQHXD on the decrease of the opening of TJ also reduced the content of muscone,ligustilide and hydroxysafflor yellow A in cerebrospinal fluid.
文摘OBJECTIVE Scalp mechanical stimulation, like combing, is one of the useful methods to keep brain health, which was historically recorded in traditional Chinese medicine thousand years ago. For the brain care, it is considered to promote cerebrovascular circulation to prevent alopecia,headache, neurasthenia, insomnia, memory deficits. However, few study was reported on its effect and how the scalp mechanical stimulation works on vascular functions. Therefore, in this study, we try to illustrate the effect of combing on the cerebrovascular. METHODS In vivo, the anesthetized mice have been used to observe the effects of scalp mechanical stimulation. Infrared thermal imaging has been used to measure the skin temperature;vasodilation has been evaluated by retro-orbital injection of FITC-dextran 150 ku;the permeability of Blood-Brain Barrier(BBB) was analyzed by confocal microscopy of FITC-dextran 40 ku extravasation and a spectrofluorometric assay of Even Blue extravasation.RESLUTS We found that scalp mechanical stimulation rather than on the back can maintain the body temperature, especially raise the temperature in the ears. Accordingly, a moderate vasodilatation of auricles′ capillaries(≤ 8 μm) was observed, the phenomenon of which did not occur combing on the back. Furthermore, the permeability of BBB was promoted by the assays of small molecular extravasation. In addition, in vivo imaging, the small molecular of FITC-dextran(40 ku) was found to transport far away from the blood vessels into the brain parenchyma with the lapse of time. CONCLUSION Scalp mechanical stimulation can work on vasodilatation of auricles and promotion of BBB under a biological condition. Combing, as a daily behavior, simple but may yield novel insights into neuroprotection.
基金The project supported by National Natural Science Foundation of China(81302760)the Chinese Postdoctoral Science Foundation Project(2013M542510)
文摘OBJECTIVE To investigate the role of chemokine-like factor 1(CKLF1),a novel C-C chemokine,on brain-blood barrier(BBB)integrity in rat focal cerebral ischemia and reperfusion model.METHODS Antibodies against CKLF1 was applied to the rightcerebral ventricle immediately after transient middle cerebral artery occlusion.Brain water content,Evans blue leakage and the expression of aquaporin-4(AQP-4),matrix metalloproteinase-9(MMP-9),zonula occludens-1(ZO-1)and occludin were measured.RESULTS After treatment with antiCKLF1 antibody,brain water content and Evans blue leakage in ipsilateral hemisphere were decreased in a dose-dependent manner at 24 h after reperfusion,but not changed in contralateral hemisphere.Anti-CKLF1 antibody reduced the expression of AQP-4 and MMP-9,and upregulated the expression of ZO-1 and Occludin.These results suggest that CKLF1 is involved in BBB disruption after reperfusion.CONCLUSION Inhibition of CKLF1 protects against cerebral ischemia by maintaining BBB integrity,possibly via inhibiting the expression of AQP-4 and MMP-9,and increasing the expression of tight junction protein.
文摘The integrity and function dysfunction of the blood brain barrier(BBB)is considered to be an early event in the pathogenesis of a variety of neurological diseases in old patients and dysfunction of BBB could be induced bycommon stress that old people often face,such as sepsis during which lipopolysaccharide(LPS)is released into circulation and BBB is damaged.Since decreased melatonin level had been shown in the serum and brain of old people and mice,we aim to investigate whether supplement with melatonin could alleviate LPSinduced BBB damage in old mice.Mice(24-28 months old)received one week melatonin(10 mg·kg-1·d-1,intraperitoneally,ip)or saline before challenge with LPS(1 mg·kg-1,ip).Evan′s blue(EB)and immunoglobulin G(Ig G)leakage were used to assess the BBB permeability.Immunofluoresence and Western blotting were used to detect the protein expression and distribution.Our results showed that LPS significantly increased BBB permeability in old mice accompanied by tight junction protein occludin and claudin-5 degradation,inhibition of AMP-activated protein kinase(AMPK)activation and increase of gp91phox protein expression.Interestingly,one week of melatonin treatment significantly decreased LPS-induced BBB hyperpermeability,activated AMPK and inhibited gp91phox expression upregualtion.Moreover,activation of AMPK by metformin significantly inhibited LPS-induced gp91phox expression upregualtion in endothelial cells.Taken together,our findings demonstrate that melatonin alleviates LPS-impaired integrity of BBB by activation of AMPK and inhibition of gp91phox expression in old mice.
文摘The purpose of this study was to develop a quantitative structure–property relationship(QSPR) model based on the enhanced replacement method(ERM) and support vector machine(SVM) to predict the blood-to-brain barrier partitioning behavior(log BB) of various drugs and organic compounds. Different molecular descriptors were calculated using a dragon package to represent the molecular structures of the compounds studied. The enhanced replacement method(ERM) was used to select the variables and construct the SVM model. The correlation coefficient, R^2, between experimental results and predicted log BB was 0.878 and 0.986, respectively. The results obtained demonstrated that, for all compounds, the log BB values estimated by SVM agreed with the experimental data, demonstrating that SVM is an effective method for model development, and can be used as a powerful chemometric tool in QSPR studies.
基金supported by National Natural Science Foundation of China(8142204981473208+3 种基金816734858137341481130061) National 863 Plan Young Scientist Program of China(2015AA020943)
文摘OBJECTIVE Tissue plasminogen activator(tPA) is the only approved pharmaco.logical therapy for acute brain ischaemia;however,a major limitation of tPA is the haemorrhagic trans.formation that follows tPA treatment.Here,we determined whether nicotinamide mononucleotide(NMN),a key intermediate of nicotinamide adenine dinucleotide biosynthesis,affects tPA-induced haemorrhagic transformation.METHODS Middle cerebral artery occlusion(MCAO) was achieved in CD1 mice by introducing a filament to the left MCA for 5 h.When the filament was removed for reperfusion,tPA was infused via the tail vein.A single dose of NMN was injected i.p.(300 mg·kg^(-1)).Mice were killed at 24 h post ischaemia,and their brains were evaluated for brain infarction,oedema,haemoglobin content,apoptosis,neuroinflammation,blood-brain barrier(BBB) permeability,the expression of tight junction proteins(TJPs) and the activity/expression of MMPs.RESULTS In the mice infused with tPA at 5 h post ischaemia,there were significant increases in mortality,brain infarction,brain oedema,brain haemoglobin level,neural apoptosis,Iba-1 staining(microglia activation) and myeloperoxidase staining(neutrophil infiltration).All these tPA-induced alterations were significantly prevented by NMN administration.Mechanistically,the delayed tPA treatment increased BBB permeability by downregulating TJPs,including claudin-1,occludin and zonula occludens-1,and enhancing the activities and protein expression of MMP9 and MMP2.Similarly,NMN administration partly blocked these tPAinduced molecular changes.CONCLUSION Our results demonstrate that NMN ameliorates tPAinduced haemorrhagic transformation in brain ischaemia by maintaining the integrity of the BBB.
文摘Suppression of excessive inflammation can ameliorate blood brain barrier （BBB） injury, which shows therapeutic potential for clinical treatment of brain injury induced by stroke superimposed on systemic inflammatory diseases. In this study, we investigated whether and how clematichinenoside （AR）, an anti-inflammatory triter- pene saponin, protects brain injury from stroke superimposed on systemic inflammation. Lipopolysaccharide （LPS） was intraperitoneally injected immediately after middle cerebral artery occlusion （MCAO） in rats. Rat microvessel endothelial cells （rBMECs） were exposed to hypoxia/reoxygenation （H/R） coexisting with LPS. The results re- vealed that AR suppressed the excessive inflammation, restored BBB dysfunction, alleviated brain edema, de- lessened neurological dysfunction, and decreased infarct rate. Further study demon- creased neutrophil infiltration, inducible nitric oxide synthase （iNOS） , strated that the expression of nucleus nuclear factor kappa B （NF-KB）, intercellular adhesion molecule-1 （ ICAM-1 ）, tumor necrosis factor-α （TNF-α） and interlukin-1β （ IL-1β） were suppressed by AR via zinc finger protein A20. Besides, AR increased in vitro BBB integrity through A20. In con- clusion, AR alleviated cerebral inflammatory injury through A20-NF-KB signal pathway, offering an alternative medication for stroke associated with systemic inflammatory diseases.
文摘Astrocytes are implicated in the pathological changes of Alzheimer's disease. Our previous studies have demonstrated that estrogen deprivation and oxidative stress act synergistically to accelerate the progress of Alzheimer's disease. Long-term D-galactose injection combined with ovariectomy may serve as a rodent model for Alzheimer's disease. To address the potential contribution of astroglia to the Alzheimer's disease pathogenesis, we investigated pathological and biochemical alterations of astrocytes under this animal model. Ovadectomized rats injected with D-galactose for 2 weeks showed extensive localization of glial fibrillary acidic protein immunoreactive astrocytes and slightly elevated glutathione levels in the hippocampus without significant impairments in the water maze test and deficits of the cholinergic analyses, compared to the saline-injected rats. Ovariectomized rats injected with D-galactose for 6 weeks, however, exhibited degeneration of astrocytes and decreased glutathione levels in the hippocampus, accompanied with severe dysfunction of behavioral test and deficiency of cholinergic terminals. Electron microscopy further confirmed the pathological changes of astrocytes, especially in the aggregated area of synapse and brain microvessels. Consistent with degeneration of perivascular astrocytic endfeet, analysis of the horseradish peroxidase demonstrated an impairment of the blood-brain barrier permeability. These findings indicate that biochemical and pathological alterations of astrocytes may partially contribute to exacerbating neuronal deficits in the course of Alzheimer's disease. Restoring neuroprotective potential of astrocytes may be a useful therapeutic target for Alzheimer's disease and other neurodegenerative diseases.
文摘目的研究临床经验复方补肾活血方对慢性脑低灌注(chronic cerebral hypoperfusion,CCH)小鼠髓鞘以及认知功能的影响。方法选择30只无特定病原体级雄性C57BL/6J小鼠,按照随机数字表分为假手术组8只和手术组22只。手术组应用微弹簧双侧颈总动脉狭窄法构建CCH小鼠模型。假手术组小鼠仅分离双侧迷走神经。手术组22只小鼠术后2 d共死亡6只,其余16只成活小鼠按随机数字表法分为模型组及治疗组,每组8只。手术2周后治疗组给予补肾活血方中草药汤剂0.2 ml/d灌胃,假手术组及模型组给予等体积纯水灌胃,连续灌胃60 d。采用Morris水迷宫实验评价各组小鼠认知功能的变化,采用MRI检测弥散张量成像-分数各向异性(diffusion tensor imaging-fractional anisotropy,DTI-FA)评价小鼠脑白质病变,采用劳克坚牢蓝(Luxol fast blue,LFB)染色观察胼胝体区脱髓鞘情况,采用尼氏染色观察海马CA1区神经元损伤情况。结果与假手术组比较,模型组小鼠Morris水迷宫第5天游泳距离及逃避潜伏期显著延长、穿越平台次数、DTI-FA值、LFB染色髓鞘吸光度值、尼氏染色海马区神经元数量明显降低,差异有统计学意义(P<0.05,P<0.01);与模型组小鼠比较,治疗组Morris水迷宫第5天游泳距离[188.14(105.19,342.00)cm vs 280.22(168.47,501.37)cm,P<0.05]、逃避潜伏期第5天[10.22(5.77,19.47)s vs 19.39(13.57,31.09)s,P<0.01]显著缩短,穿越平台次数[3.00(2.00,4.00)次vs 2.00(1.00,3.00)次,P<0.05]、DTI-FA值(0.34±0.01 vs 0.31±0.01,P<0.01)、LFB染色髓鞘吸光度值[0.353(0.328,0.364)vs 0.305(0.290,0.350),P<0.05]以及尼氏染色神经元数量明显升高,差异有统计学意义[(9.94±2.22)个vs(7.11±2.02)个,P<0.01]。结论补肾活血方可以通过修复白质微结构、挽救神经元丢失,并且改善CCH小鼠的认知功能障碍。
