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Aim To investigate the dynamic time-course changes in neuronal cytoskeleton after acute ischemia and reperfusion in rats. Methods Reperfusion was performedin rats by blocking the middle cerebralarteryfor 90 min, then therats wereobserved and collected at different time points. The brain damage wasobserved by Nissl staining,and neurobehavioural function was evaluated with neurological deficit score and forelimb placement test. The cellular changes in the alternations of cytoskeletal elements including microtubule associated protein 2 (MAP2) and neurofilament heavy chain (NF-H) were observed by immunohistochemistry staining and Western blot. Impaired axons, dendrites and cytoskeletal alternations were detected by electron microscope. Results Brain damage and neurobehavioural function were gradually aggravated with the prolongation of reperfusion. Brain damage appeared earlier and more severe in striatum than in cortex. Moreover, decreased MAP2-related and increased NF-H-related immunoreactive intensities were found in the ischemic areas. Impaired cytoskeletal arrangement and reduced dense were indicated. Damaged cytoskeletal components such as microtubules and neurofilament arrangement, decreased axonal filament density, and swelled dendrites were observed after cerebral ischemia reperfusion by ultrastructural observations. Conclusions Different brain regions have diverse tolerance to ischemia-reperfusion injury. Major elements of neuronal cytoskeleton show dynamic responses to ischemia and reperfusion, which may further contribute to brain damage and neurological impairment following MCAO and reperfusion.
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Ischemic stroke is the second leading cause of human death and the third reason of disability. Meanwhile, the incidence is rising year after year worldwide. Ischemic stroke could cause ischemia-reperfusion injury after blood recanalization treat-ment, but the mechanism of ischemia-reperfusion injury is still not very clear, so it is necessary to build a preclinical model with specific characteristics. Up to now, animal experiments have been still complicated, and the culture of brain slices has some limitations. The cell model in vitro has become a simplified and valuable tool widely used by researchers. The paper systematically summarizes the common type of nerve cells, and further analyzes establishment methods and principle, relevant research progress on the in vitro model of ischemia-reperfusion, in order to provide reference for rationally selecting hypoxia and reoxygenation model for basic research on cerebral ischemia and reperfusion and drug screening.
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Aim To observe cellular damage and astrocyte activation at different time points of cerebral ischemia and reperfusion. Methods The middle cerebral artery of male SpragueDawley rats was occluded for 90 min followed by different time points of reperfusion. Eighty-five SPF male SD rats were randomly divided into control group (Sham), IR3, 6, 12, 24 and IR48h (MCAO followed by 48 h of reperfusion) group. Cerebral ischemia and reperfusion injury was observed by HE staining, and the structure of astrocytes was estimated with transmission electron microscopy (TEM). GFAP expression was detected by immunofluorescence staining and Western blot. Results Cerebral ischemia following by different time points of reperfusion led to different degrees of cellular damage, which was the most serious at 24 h of reperfusion. TEM showed destruction of astrocytes structure, swollen organelles and broken mitochondrial ridge. After cerebral ischemia-reperfusion, the expression levels of GFAP were significant up-regulated in the ischemic penumbra cortex and the highest was at 48 h of reperfusion, indicating astrocytes were activated. In addition, the results showed the gradual decrease in GFAP expression in the infarct core. Conclusions After cerebral ischemia-reperfusion, cellular damage is aggravated, and astrocytes are gradually activated in the ischemic penumbra. With the extension of reperfusion time, the boundaries of infarct area and ischemic area are gradually clear, and scarring may occur.
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Stroke is the second leading cause of death in the world, of which about 60 % - 80 % are ischemic stroke. Ischemic stroke will inevitably cause the damage of neurons in the core area. With the increase of ischemic time, other neurons in the ischemic penumbra will also die due to the loss of " signal connection", and further lead to body dysfunction. In view of the complexity of neuronal death mechanism after ischemic stroke, understanding the action principle of death mechanism can better save ischemic penumbra neurons. This review mainly expounds several main mechanisms and potential therapeutic targets of neuronal death after ischemic stroke, so as to provide basis and help for the improvement of action mechanism research and drug development.
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This study aims to explore the effect of Xiaoxuming Decoction on synaptic plasticity in rats with acute cerebral ischemia-reperfusion. A rat model of cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion(MCAO). Rats were randomly assigned into a sham group, a MCAO group, and a Xiaoxuming Decoction(60 g·kg~(-1)·d~(-1)) group. The Longa score was rated to assess the neurological function of rats with cerebral ischemia for 1.5 h and reperfusion for 24 h. The 2,3,5-triphenyltetrazolium chloride(TTC) staining and hematoxylin-eosin(HE) staining were employed to observe the cerebral infarction and the pathological changes of brain tissue after cerebral ischemia, respectively. Transmission electron microscopy was employed to detect the structural changes of neurons and synapses in the ischemic penumbra, and immunofluorescence, Western blot to determine the expression of synaptophysin(SYN), neuronal nuclei(NEUN), and postsynaptic density 95(PSD95) in the ischemic penumbra. The experimental results showed that the modeling increased the Longa score and led to cerebral infarction after 24 h of ischemia-reperfusion. Compared with the model group, Xiaoxuming Decoction intervention significantly decreased the Longa score and reduced the formation of cerebral infarction area. The modeling led to the shrinking and vacuolar changes of nuclei in the brain tissue, disordered cell arrangement, and severe cortical ischemia-reperfusion injury, while the pathological damage in the Xiaoxuming Decoction group was mild. The modeling blurred the synaptic boundaries and broadened the synaptic gap, while such changes were recovered in the Xiaoxuming Decoction group. The modeling decreased the fluorescence intensity of NEUN and SYN, while the intensity in Xiaoxuming Decoction group was significantly higher than that in the model group. The expression of SYN and PSD95 in the ischemic penumbra was down-regulated in the model group, while such down-regulation can be alleviated by Xiaoxuming Decoction. In summary, Xiaoxuming Decoction may improve the synaptic plasticity of ischemic penumbra during acute cerebral ischemia-reperfusion by up-regulating the expression of SYN and PSD95.
Subject(s)
Rats , Animals , Rats, Sprague-Dawley , Brain Ischemia/drug therapy , Reperfusion Injury/metabolism , Infarction, Middle Cerebral Artery , Neuronal Plasticity , ReperfusionABSTRACT
This study investigated the effect of Xiaoxuming Decoction(XXMD) on the activation of astrocytes after cerebral ischemia/reperfusion(I/R) injury. The model of cerebral IR injury was established using the middle cerebral artery occlusion method. Fluorocitrate(FC), an inhibitor of astrocyte activation, was applied to inhibit astrocyte activation. Rats were randomly divided into a sham group, a model group, a XXMD group, a XXMD+FC group, and a XXMD+Vehicle group. Neurobehavioral changes at 24 hours after cerebral IR injury, cerebral infarction, histopathological changes observed through HE staining, submicroscopic structure of astrocytes observed through transmission electron microscopy, fluorescence intensity of glial fibrillary acidic protein(GFAP) and thrombospondin 1(TSP1) measured through immunofluorescence, and expression of GFAP and TSP1 in brain tissue measured through Western blot were evaluated in rats from each group. The experimental results showed that neurobehavioral scores and cerebral infarct area significantly increased in the model group. The XXMD group, the XXMD+FC group, and the XXMD+Vehicle group all alleviated neurobehavioral changes in rats. The pathological changes in the brain were evident in the model group, while the XXMD group, the XXMD+FC group, and the XXMD+Vehicle group exhibited milder cerebral IR injury in rats. The submicroscopic structure of astrocytes in the model group showed significant swelling, whereas the XXMD group, the XXMD+FC group, and XXMD+Vehicle group protected the submicroscopic structure of astrocytes. The fluorescence intensity and protein expression of GFAP and TSP1 increased in the model group compared with those in the sham group. However, the XXMD group, the XXMD+FC group, and XXMD+Vehicle group all down-regulated the expression of GFAP and TSP1. The combination of XXMD and FC showed a more pronounced effect. These results indicate that XXMD can improve cerebral IR injury, possibly by inhibiting astrocyte activation and down-regulating the expression of GFAP and TSP1.
Subject(s)
Rats , Animals , Astrocytes , Brain Ischemia/metabolism , Brain , Reperfusion Injury/metabolism , Infarction, Middle Cerebral ArteryABSTRACT
<p><b>OBJECTIVE</b>To explore the effects of acrylamide on the permeability of blood cerebrospinal fluid barrier (BCB) and tight junction protein ZO-1 of choroid plexus in rats and to provide a theoretical basis for explaining the mechanism of nerve injury induced by acrylamide.</p><p><b>METHODS</b>Thirty two male Sprague-Dawley rats were randomly divided into ACR and control groups. ACR group was exposed to 20 mg/kg ACR daily for 5 days a week by intraperitoneal injection (i.p.) for 4 weeks. Control group was exposed to normal saline. The neurobehavioral tests (including sensatory and motor functions) were performed every week. At the end of exposure, Evan blue (EB) and Sodium fluorescein (NaFI) content in rat CSF were detected for determining the BCB permeability, Real-time PCR was used to measure the expression levels of ZO-1 mRNA in the epithelium cells of choroid plexus, and laser scanning confocal microscope (LSCM) was utilized to observe the distribution of ZO-1 protein.</p><p><b>RESULTS</b>Neurobehavioral tests showed that the tail-flick latencies of ACR group were 27.77% and 53.71% as long as control group in the 3rd week and 4th week, respectively (P < 0.05). The hind lamb splay distances of ACR group were 131.76% and 153.77% as long as control group in the 3rd week and 4th week, respectively (P < 0.05). Evan blue (EB) and Sodium fluorescein (NaFI) content of ACR group were significantly higher than those of control group (P < 0.05). In the 4th week, the expression level of ZO-1 mRNA in ACR group was 0.21 +/- 0.07, which was significantly lower than that (0.31 +/- 0.11) in control group (P < 0.05). In the 4th week, the ZO-1 protein expression level of choroid plexus in ACR group was significantly lower than that in control group (P < 0.05).</p><p><b>CONCLUSION</b>Acrylamide could increased the BCB permeability of rats, which may be involved in the central nervous injury induced by ACR.</p>
Subject(s)
Animals , Male , Rats , Acrylamide , Toxicity , Blood-Brain Barrier , Choroid Plexus , Metabolism , Permeability , Rats, Sprague-Dawley , Zonula Occludens-1 Protein , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the renal protective effects of sulodexide and its anti-oxidative stress mechanism in diabetic rats.</p><p><b>METHOD</b>Thirty male SD rats were randomized into 3 equal groups, namely the control group, diabetic group, and sulodexide treatment group. Twelve weeks after establishment of rat diabetic models and administration of sulodexide, the rats were sacrificed for measurement of the urine volume, body mass, kidney mass/body weight ratio, plasma glucose, and glycosylated hemoglobin (HbA1c). Malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) activities in the renal tissue or serum were tested. Electron microscopy was performed to observe the pathological changes in the kidneys.</p><p><b>RESULTS</b>The urine volume, renal mass/body mass ratio, serum glucose, HbA1C, and serum and renal MDA levels all significantly increased in the diabetic rats in comparison with the normal controls (P<0.05). But the body weight and activities of SOD, CAT, and GSH-PX in the renal tissue in the normal control group were significantly higher than those in the diabetic and sulodexide group. After 12 weeks of sulodexide treatment, SOD, CAT, and GSH-PX activities in the renal tissue of rats were significantly increased in comparison with those in the diabetic rats (P<0.05). Electron microscopy showed obvious irregular thickening of the glomerular capillary basement membrane in the diabetic group with vacuolization in the mitochondria in the epithelial cells, and such pathological changes were significantly alleviated in the sulodexide treatment group.</p><p><b>CONCLUSIONS</b>Sulodexide can effectively lower the urinary albumin excretion rate, improve the ultrastructural renal pathologies and prevent glomerular basement membrane thickening in diabetic rats, probably in association with the reduction of the MDA levels and enhancement of SOD, CAT, and GSH-PX activities.</p>
Subject(s)
Animals , Male , Rats , Antioxidants , Pharmacology , Therapeutic Uses , Body Weight , Catalase , Metabolism , Diabetes Mellitus , Drug Therapy , Metabolism , Pathology , Glutathione Peroxidase , Metabolism , Glycosaminoglycans , Pharmacology , Therapeutic Uses , Kidney , Metabolism , Pathology , Malondialdehyde , Metabolism , Organ Size , Rats, Sprague-Dawley , Superoxide Dismutase , MetabolismABSTRACT
Objective To observe the cost-effectiveness of using continuous subcutaneous insulin infusion (CS Ⅱ) and multi-point daily insulin injections (MDI) in controlling blood sugar in the newly hospitalized type 2 diabetes patients. Methods Retrospective analysis on 86 cases taking CS Ⅱ and 103 cases using MDI on a 'blood sugar control program' among the newly hospitalized patients with type 2 diabetes. The period for observation was 2 weeks, using cost-effectiveness analysis methods to evaluate the two treatment programs. Results After two weeks of treatment, the effectiveness in the control of blood sugar in CS Ⅱ group was similar to the MDI group, with no significant difference(P<0.05) and the adverse reactions were similar. Costs in the CS Ⅱ program (Yuan/person) was less than in the MDI program (1478.34 vs. 1620.46), with significant differences (P< 0.05). The cost-effectiveness ratios (C/E) were 15.07 in the CS Ⅱ group, and 16.34 in the MDI group, with no significant difference (P>0.05). In order to further reduce the cost of CS Ⅱ group as a reference, the incremental cost-effectiveness ratio (△C/ △E)ofthe MDI group was 129.20. Conclusion Costs-effective of the CS Ⅱ program was better than the MDI one in treating the newly hospitalized patients with type 2 diabetes, suggesting that CS Ⅱ program might be a better choice for hospitals to carry on an intensive insulin therapy program.
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<p><b>OBJECTIVE</b>To study the expression of HBsAg and HBcAg in hepatocytes in CHB patients, and analyze the correlation among the expression of HBsAg and HBcAg, the quantity of HBV DNA in serum, the pathology of liver tissue and the clinical manifestation.</p><p><b>METHODS</b>Quantitative polymerase chain reaction was used to assay the quantity of HBV DNA in serum in 351 CHB patients. Furthermore pathological diagnosis was performed using liver biopsy to assay the expression of HBsAg and HBcAg in hepatocytes by an immunohistochemical staining technique.</p><p><b>RESULTS</b>The positive expression rate of HBsAg and HBcAg in hepatocytes was 92.3% and 76.9% respectively. Cytoplasm-membrane HBcAg expression type (75.6%) was observed in the CHB with more active inflammation, while Nucleus HBcAg expression type (24.4%) was observed in the CHB with more sedative one (P < 0.0001). The expression of HBsAg was correlated with the quantity of HBV DNA in serum (rp = 0.24, P = 0.0129), while inversely correlated with the inflammation and the fibrillation of liver tissue (rp = -0.22, P = 0.0279; rp = -0.23, P = 0.0186). The expression of HBcAg was correlated with the quantity of HBV DNA in serum (rp = 0.52, P < 0.0001), while was inversely correlated with the inflammation and the fibrosis of liver (rp = -0.33, P < 0.0001; rp = -0.34, P < 0.0001).</p><p><b>CONCLUSION</b>Cytoplasm-membrane HBcAg expression type was observed in the CHB with more active inflammation, while Nucleus HBcAg expression type was observed in the CHB with mild change. In the immunopathogenesis of the liver damage in CHB, HBcAg might be a main target antigen. HBsAg might be a sensitive index to screen HBV infection; HBcAg might probably be a reliable index to evaluate the replication of HBV</p>
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Male , Middle Aged , DNA, Viral , Blood , Hepatitis B Core Antigens , Hepatitis B Surface Antigens , Hepatitis B, Chronic , Allergy and Immunology , Pathology , Virology , Hepatocytes , Virology , Immunohistochemistry , Liver , PathologyABSTRACT
A total of 126 patients with type 2 diabetes mellitus were randomized into two groups:one received glimepiride 1 mg twice daily and the other 2 mg once daily.Fasing blood glucose(BG),BG 2 h after meals(breakfast,lunch and dinner)and HbA_(IC)were tested,△and standard deviation of the 4 point BG were calculated.It was found that two kinds of administration of glimepiride were equally effective in decreasing BG and once daily aministration could ease better the fluctuation of BG.