Electroacupuncture improves cognitive function through Rho GTPases and enhances dendritic spine plasticity in rats with cerebral ischemia-reperfusion.

The aim of the present study was to evaluate the effect of electroacupuncture (EA) on cognitive function following cerebral ischemia­reperfusion (I/R) injury, and to clarify the mechanism through which Rho GTPase is associated with EA analgesia modulation of dendritic spine plasticity. Rats were randomly divided into three groups: The sham surgery group, the middle cerebral artery occlusion (MCAO) model of ischemia group, and the MCAO with EA (MCAO+EA) treatment group. The MCAO+EA group received treatment with EA at points of Baihui (DU20) and Shenting (DU24) following surgery. It was demonstrated that treatment with EA significantly (P<0.05) protected the cognitive function of rats from impairment caused by cerebral I/R injury. Furthermore, EA treatment increased the density of dendritic spines in the hippocampus of cerebral I/R­injured rats. Simultaneously, EA increased the expression of cell division cycle 42, Ras­related C3 botulinum toxin substrate 1 and F­actin proteins. By contrast, EA treatment inhibited the expression of Ras homologous member A. Collectively, these findings suggest that Rho GTPases and dendritic spine plasticity are critical in mediating the effects of EA treatment at the points of Shenting and Baihui, and that EA protects against impairment of cognitive function following ischemic stroke.

[Effect of Electroacupuncture on Expression of Cortical srGAP 1 and Cdc 42 in Rats with Focal Cerebral Infarction].

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention on the neurological function and the expression change of Slit-Robo GTPase-activating protein-1 (srGAP 1) and cell division-cycle 42 (Cdc 42) in the cortex of rats with cerebral ischemic injury (CIRI) , so as to explore the mechanism of EA in the management of cerebral infarction. METHODS: A total of 48 male Sprague Dawley (SD) rats were randomly and equally divided into control, model, non-acupoint EA and EA groups (n = 12/group). The CIRI model was established based on the modified Zea Longa method. EA intervention was applied for 30 min, once a day for 14 days. Modified neurologic severity scores (mNSS) were assessed on day 1,3,7 and 14 after mode- ling. Immunofluorescence assay was used to detect the immunoactivity and distribution of srGAP 1 and Cdc 42 in the cortical ischemic region. Western blot was employed to detect the expression of srGAP 1 and Cdc 42 in the affected cortex. RESULTS: The mNSS displayed that the neurological score in the EA group was significantly lower than that in the model group and non-acupoint EA group at the 7th d and 14th d (P<0. 01). Immunofluorescence results showed that cerebral srGAP 1 and Cdc 42 were ex- pressed mainly in the cytoplasm. The fluorescence intensity of srGAP 1 of the EA group was significantly lower than that of the model group and non-acupoint EA group(P<0. 01). Meanwhile the fluorescence intensity of Cdc 42 of the EA group was markedly higher than that in the model group and non-acupoint EA group(P<0. 01). Western blot assay indicated that the expression level of srGAP 1 in the model group was significantly higher than that of the control group( P<0. 01) ,and that of the EA group was much lower than those of the model group and non-acupoint EA group(P<0. 01). There was no significant difference of srGAP 1 expression levels between the non-acupoint EA group and the model group(P>0. 05). Additionally, the protein expression of Cdc 42 in the model group was slightly higher than that of the control group(P>0. 05), and that of the EA group was significantly higher than those of the model group and non-acupoint EA group(P<0. 01). There was no significant difference of Cdc 42 expression levels between the non-acupoint EA group and the model group(P>0. 05). CONCLUSION: Cerebral infarction induced increase of cerebral srGAP 1 and decrease of Cdc 42 can be reversed by acupoint EA intervention in CIRI rats, which may be responsible for its effect in improving impaired neurological function after cerebral infarction.

[Effect of Electroacupuncture at "Shuigou" (GV 26) on Immunoactivity and Content of Protein Kinase C in the Middle Cerebral Artery in Acute Cerebral Infarction Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention on expression and content of protein kinase C (PKC) in the middle cerebral artery in acute cerebral infarction (ACI) rats so as to explore its mechanism underlying improvement of ACI. METHODS: Wistar rats were randomly divided into normal control (n = 6), sham operation (n = 30), ACI model (n = 30), and EA (n = 30) groups, and the latter three groups were further divided into 0. 5 h, 1 h, 3 h, 6 h and 12 h subgroups (n = 6 in each subgroup). The ACI model was established by occlusion of the middle cerebral artery (MCAO). EA (15 Hz, 1 mA) was applied to "Shuigou" (GV 26) for 20 min. The PKC expression levels and activity in the vascular smooth muscle of the middle cerebral artery were detected using immunohistochemistry and ELISA, respectively. RESULTS: In comparison with the control group, the immunoactivity and activities of PKC in the middle cerebral artery tissue at 0. 5 h, 1 h, 3 h, 6 h and 12 h were significantly increased in the model group (P<0. 05). After EA intervention, the expression levels and activities of PKC at the 5 time-points were markedly down-regulated in comparison with the model group at the same corresponding time-point (P<0. 05). No significant changes of PKC expression and activity were found in the sham operation group (P>0. 05). CONCLUSION: EA intervention can up-regulate the immunoactivity and activity of PKC in the vascular smooth muscle of the middle cerebral artery in ACI rats, which may contribute to its effect in improving ACI by relieving arterial spasm.

[Effect of electroacupuncture intervention on expression of vascular PKC in the ischemic cerebral tissue in rats with cerebral infarction].

OBJECTIVE: To observe the effect of electroacupunctur (EA) of Shuigou(GV 26)on the expression of vascular protein kinase C (PKC) in the focal ischemia cerebral tissue in rats so as to study its dynamic regulation mechanism. METHODS: A total of 78 Wistar rats were randomly divided into model group (n = 24), EA group (n = 24), sham operation (sham) group (n = 24) and control group (n = 6). The first 3 groups were further divided into 0. 5 h, 1 h, 3 h and 6 h subgroups, with 6 cases in each. Cerebral ischemia (CI) model was established by occlusion of the middle cerebral artery. EA (15 Hz, 1.0 mA) was applied to "Shuigou" (GV 26) for 20 min. The anterior, middle and posterior cerebral arteries on the infarct side of the brain were collected for assaying the expression of PKC protein by using Western blot, and the formalin-fixed artery samples were embedded with paraffin, followed by sectioning and staining with immunohistochemistry. RESULTS: Compared with the control group, the expression levels of cerebral vascular smooth PKC protein shown by both immunohistochemistry and Western blot were upregulated significantly at the time-points of 0.5 h, 1 h, 3 h and 6 h after CI in the model group (P<0.05, P<0.01). In comparison with the model group, the expression levels of PKC protein in the cerebral vascular smooth muscle shown by the aforementioned two methods were down-regulated considerably in the EA group (P<0.01, P<0.05). No statistic differences were found between the control and sham groups in the expression of vascular PKC protein at different time-points (P>0.05). CONCLUSION: EA Intervention can significantly inhibit PKC expression in the cerebral vascular smooth muscle in CI rats, which may be responsible for its efficacy in improving ischemic stroke.

Neuroprotection of tanshinone IIA against cerebral ischemia/reperfusion injury through inhibition of macrophage migration inhibitory factor in rats.

BACKGROUND: Ischemia/reperfusion (I/R) injury is associated with systemic inflammatory response. Macrophage migration inhibitory factor (MIF) has been implicated in many inflammatory processes. Tanshinone IIA (TSA) is one of the active ingredients in danshen, which derived from the dried root or rhizome of Salviae miltiorrhizae Bge. Recent studies have demonstrated that TSA has protective effects against focal cerebral I/R injury. However, little is known about the underlying mechanisms. Here we put forward the hypothesis that TSA acts through inhibition of MIF expression during focal cerebral I/R injury in rats. METHODOLOGY/PRINCIPAL FINDINGS: Rats were subjected to middle cerebral artery occlusion (MCAO) for 2 hours. This was followed by reperfusion. We measured neurological deficits, brain water content, and infarct volume, and found that neurological dysfunction, brain edema, and brain infarction were significantly attenuated by TSA 6 hours after reperfusion. We also measured myeloperoxidase (MPO) activity at 6 and 24 hours, and found that neutrophil infiltration was significantly higher in the vehicle+I/R group than in the TSA+I/R group. ELISA demonstrated that TSA could inhibit MIF expression and the release of TNF-α and IL-6 induced by I/R injury. Western blot analysis and immunofluorescence staining showed that MIF expression was significantly lower in the TSA+I/R group than in the vehicle+I/R group. MIF was found almost all located in neurons and hardly any located in astrocytes in the cerebral cortex. Western blot analysis and EMSA demonstrated that NF-κB expression and activity were significantly increased in the vehicle+I/R group. However, these changes were attenuated by TSA. CONCLUSION/SIGNIFICANCE: Our results suggest that TSA helps alleviate the proinflammatory responses associated with I/R-induced injury and that this neuroprotective effect may occur through down-regulation of MIF expression in neurons.

Autophagosomes accumulation is associated with ß-amyloid deposits and secondary damage in the thalamus after focal cortical infarction in hypertensive rats.

Focal cerebral cortical infarction after distal middle cerebral artery occlusion causes ß-amyloid deposition and secondary neuronal degeneration in the ipsilateral ventroposterior nucleus of the thalamus. Several studies suggest that autophagy is an active pathway for ß-amyloid peptide generation. This study aimed to investigate the role of autophagy in thalamic ß-amyloid deposition and neuronal degeneration after cerebral cortical infarction in hypertensive rats. At 7 and 14days after middle cerebral artery occlusion, neuronal death and ß-amyloid deposits were evident in the ipsilateral ventroposterior nucleus, and the activity of ß-site amyloid precursor protein (APP)-cleaving enzyme 1, required for ß-amyloid peptide generation, was elevated in the thalamus. In correlation, both the number of cells showing punctate microtubule-associated protein 1A light chain 3 fluorescence and levels of light chain 3-II protein, an autophagosome marker, were markedly increased. Notably, most of the cells that over-expressed ß-site APP-cleaving enzyme 1 displayed punctate light chain 3 staining. Furthermore, the inhibition of autophagy with 3-methyladenine significantly reduced the thalamic neuronal damage, ß-amyloid deposits, and ß-site APP-cleaving enzyme 1 activity. These results suggest that autophagosomes accumulate within thalamic cells after cerebral cortical infarction, which is associated with thalamic ß-amyloid deposition and secondary neuronal degeneration via elevation of ß-site APP-cleaving enzyme 1 level.

Extension of the thrombolytic time window with minocycline in experimental stroke.

BACKGROUND AND PURPOSE: Thrombolysis with tPA is the only FDA-approved therapy for acute ischemic stroke. But its widespread application remains limited by narrow treatment time windows and the related risks of cerebral hemorrhage. In this study, we ask whether minocycline can prevent tPA-associated cerebral hemorrhage and extend the reperfusion window in an experimental stroke model in rats. METHODS: Spontaneously hypertensive rats were subjected to embolic focal ischemia using homologous clots and treated with: saline at 1 hour; early tPA at 1 hour, delayed tPA at 6 hours; minocycline at 4 hours; combined minocycline at 4 hours plus tPA at 6 hours. Infarct volumes and hemorrhagic transformation were quantified at 24 hours. Gelatin zymography was used to measure blood levels of circulating matrix metalloproteinase-9 (MMP-9). RESULTS: Early 1-hour thrombolysis restored perfusion and reduced infarction. Late 6-hour tPA did not decrease infarction but instead worsened hemorrhagic conversion. Combining minocycline with delayed 6-hour tPA decreased plasma MMP-9 levels, reduced infarction, and ameliorated brain hemorrhage. Blood levels of MMP-9 were also significantly correlated with volumes of infarction and hemorrhage. CONCLUSIONS: Combination therapy with minocycline may extend tPA treatment time windows in ischemic stroke.

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

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

Homozygous MTHFR C677T gene mutation and recurrent stroke in an infant.

The role of homozygosity for the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene as an independent risk factor for primary and recurrent stroke has been questioned, although recent data appear to be supportive. However, the association of homozygous C677T MTHFR mutation with silent brain infarctions in infancy has not been reported. The authors describe an 11-month-old male who had suffered a silent brain infarction followed by a symptomatic arterial stroke. The evaluation revealed mildly elevated homocysteine levels secondary to homozygous C677T alleles for MTHFR and iron deficiency anemia. An extensive evaluation for other causes of infarction was negative. We suggest that the mother's homozygous MTHFR status played a role in the early onset of stroke and that iron deficiency anemia may have contributed to the recurrence. The patient was treated with anticoagulation therapy, folic acid, and iron supplementation and has not had a recurrent event during 3 years of follow-up. This case provides further evidence that homozygous MTHFR mutation is a predisposing factor for early and recurrent pediatric stroke, including silent infarcts, especially in the presence of other risk factors.

A highly specific inhibitor of matrix metalloproteinase-9 rescues laminin from proteolysis and neurons from apoptosis in transient focal cerebral ischemia.

Neuronal cell death occurs during many neurodegenerative disorders and stroke. The aberrant, excessive activity of matrix metalloproteinases (MMPs), especially MMP-9, contributes directly to neuron apoptosis and brain damage (Rosenberg et al., 1996; Asahi et al., 2001; Gu et al., 2002; Horstmann et al., 2003). We determined that MMP-9 degrades the extracellular matrix protein laminin and that this degradation induces neuronal apoptosis in a transient focal cerebral ischemia model in mice. We also determined that the highly specific thiirane gelatinase inhibitor SB-3CT blocks MMP-9 activity, including MMP-9-mediated laminin cleavage, thus rescuing neurons from apoptosis. We conclude that MMP-9 is a highly promising drug target and that SB-3CT derivatives have significant therapeutic potential in stroke patients.

Expression of damage-induced neuronal endopeptidase (DINE) mRNA in peri-infarct cortical and thalamic neurons following middle cerebral artery occlusion.

Damage-induced neuronal endopeptidase (DINE) is a unique nerve-injury associated molecule, which was recently identified in a peripheral nerve injury model. The aim of this study was to determine the expression profiles and distribution of DINE in adult rats after middle cerebral artery (MCA) occlusion. Focal cerebral ischemia induced late-onset and prolonged expression of DINE mRNA in the peri-infarct cortex and specific nuclei of thalamus. Double labeling using immunohistochemistry and in situ hybridization revealed that DINE mRNA was exclusively expressed in cells that were positive to a neuronal marker NeuN. Previously established knowledge on neuroanatomical fiber connection suggests that DINE mRNA was expressed in areas projecting their axons to or through the core region of the infarction. This unique expression profile was similar to that of activating transcription factor-3 (ATF-3), which is a marker of nerve-injured neuron. More than 98% of ATF-3 immunoreactive neurons simultaneously expressed DINE mRNA, suggesting that DINE expression is observed in injured neurons of CNS as well as PNS. Since DINE expression promotes antioxidant activity, our results suggest that DINE may act as a neuroprotective molecule in neurons under ischemic insult.

[Lipid peroxides and antioxidants in the blood of patients with arteriosclerotic circulatory disorders]. / Lipidperoxide und Antioxidantien im Blut von Patienten mit arteriosklerotischen Durchblutungsstörungen.

Malondialdehyde, vitamin E, glutathione peroxidase and selenium were analysed in the blood of 96 male patients with arteriosclerotic obstructive disease in the region of the leg. Of these 32 patients additionally had manifestations of a coronary or cerebral arteriosclerosis. In the parameters mentioned no significant differences were found between patients with general arteriosclerosis and isolated arteriosclerosis of the leg. Patients with arteriosclerosis and hyperlipoproteinaemia revealed higher values of malondialdehyde than patients without hyperlipoproteinaemia. No correlations were found between malondialdehyde and total cholesterol, triglycerides, vitamin E, glutathione peroxidase as well as selenium.

Acute subcortical lesions modify cortical muscarinic receptors in human brain.

Post-mortem determinations of muscarinic cholinergic receptor parameters by means of binding procedures were carried out in human brains. In patients who died from internal capsule stroke a significant increase in cortical (Brodmann area 8) muscarinic receptor density was present when compared to non-neurological controls. No significant changes were detected in cortical choline acetyltransferase. Subcortical structures such as thalamus and caudate nucleus seemed to undergo opposite effects. It is suggested that acute interruption of fibers ascending to the cortex from subcortical areas can alter muscarinic receptor properties in the cerebral cortex.