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The aim of this study was to summarize the efficacy and tolerability of rotigotine in the treatment of primary restless legs syndrome (RLS). PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for English-language randomized controlled trials (RCTs) that assessed the effectiveness of rotigotine for RLS. The pooled mean change from baseline in International RLS (IRLS) Study Group Rating Scalescore and relative risk (RR) of response based on the Clinical Global Impression-Improvement (CGI-I) scale score were applied to evaluate the outcomes. The pooled proportions of adverse events (AEs) were also estimated. Six RCTs were included. The meta-analysis showed a favorable effectiveness of rotigotine versus placebo on RLS [mean change on IRLS score: mean difference (MD)=-4.80; 95% confidence interval (CI): -5.90 to -3.70; P<0.00001 and RR of response on CGI-I was 2.19; 95% CI: 1.86 to 2.58, P<0.00001]. The most common AEs were application site reactions, nausea, headache and fatigue. In general, rotigotine was well-tolerated in patients with primary RLS. Based on the findings from the meta-analysis, rotigotine was more significantly efficacious in the treatment of RLS than placebo. Nevertheless, long-term studies and more evidence of comparisons of rotigotine with other dopamine agonists are needed.
Subject(s)
Humans , Placebos , Randomized Controlled Trials as Topic , Restless Legs Syndrome , Drug Therapy , Tetrahydronaphthalenes , Therapeutic Uses , Thiophenes , Therapeutic UsesABSTRACT
The aim of this study was to summarize the efficacy and tolerability of rotigotine in the treatment of primary restless legs syndrome (RLS). PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for English-language randomized controlled trials (RCTs) that assessed the effectiveness of rotigotine for RLS. The pooled mean change from baseline in International RLS (IRLS) Study Group Rating Scalescore and relative risk (RR) of response based on the Clinical Global Impression-Improvement (CGI-I) scale score were applied to evaluate the outcomes. The pooled proportions of adverse events (AEs) were also estimated. Six RCTs were included. The meta-analysis showed a favorable effectiveness of rotigotine versus placebo on RLS [mean change on IRLS score: mean difference (MD)=-4.80; 95% confidence interval (CI): -5.90 to -3.70; P<0.00001 and RR of response on CGI-I was 2.19; 95% CI: 1.86 to 2.58, P<0.00001]. The most common AEs were application site reactions, nausea, headache and fatigue. In general, rotigotine was well-tolerated in patients with primary RLS. Based on the findings from the meta-analysis, rotigotine was more significantly efficacious in the treatment of RLS than placebo. Nevertheless, long-term studies and more evidence of comparisons of rotigotine with other dopamine agonists are needed.
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Under global cerebral ischemia, the effect of different brain temperature on cerebral ischemic injury was studied. Male Sprague-Dawley rats were divided into normothermic (37-38°C) ischemia, mild hypothermic (31-32°C) ischemia, hyperthermic (41-42°C) ischemia and sham-operated groups. Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model and brain temperature was maintained at defined level for 60 min after 20-min ischemia. The expression of c-fos protein and the levels of malondialdehyde (MDA) and lactate in brain regions were detected by immunochemistry and spectrophotometrical methods, respectively. C-fos positive neurons were found in the hippocampus and cerebral cortex after cerebral ischemia reperfusion. Mild hypothermia increased the expression of c-fos protein in both areas, whereas hyperthermia decreased the expression of c-fos protein in the hippocampus at 24 h reperfusion, and the cerebral cortex at 48 h reperfusion when compared to normothermic conditions. In normothermic, mild hypothermic and hyperthermic ischemia groups, the levels of MDA and lactate in brain tissue were increased at 24, 48 and 72 h reperfusion following 20-min ischemia as compared with the sham-operated group (P<0.01). The levels of MDA and lactate in mild hypothermic group were significantly lower than those in normothermic group (P<0.01). It is suggested that brain temperature influences the translation of the immunoreactive protein product of c-fos after global cerebral ischemia, and MDA and lactate are also affected by hypothermia and hyperthermia.
Subject(s)
Animals , Male , Rats , Body Temperature , Brain , Metabolism , Brain Ischemia , Metabolism , Cerebral Cortex , Metabolism , Hippocampus , Metabolism , Immunochemistry , Lactic Acid , Metabolism , Malondialdehyde , Metabolism , Proto-Oncogene Proteins c-bcl-2 , Metabolism , Proto-Oncogene Proteins c-fos , Metabolism , Rats, Sprague-Dawley , Reperfusion Injury , Metabolism , Spectrophotometry , Temperature , Time Factors , Tumor Suppressor Protein p53 , MetabolismABSTRACT
Under global cerebral ischemia, the effect of different brain temperature on cerebral ischemic injury was studied. Male Sprague-Dawley rats were divided into normothermic (37-38°C) ischemia, mild hypothermic (31-32°C) ischemia, hyperthermic (41-42°C) ischemia and sham-operated groups. Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model and brain temperature was maintained at defined level for 60 min after 20-min ischemia. The expression of c-fos protein and the levels of malondialdehyde (MDA) and lactate in brain regions were detected by immunochemistry and spectrophotometrical methods, respectively. C-fos positive neurons were found in the hippocampus and cerebral cortex after cerebral ischemia reperfusion. Mild hypothermia increased the expression of c-fos protein in both areas, whereas hyperthermia decreased the expression of c-fos protein in the hippocampus at 24 h reperfusion, and the cerebral cortex at 48 h reperfusion when compared to normothermic conditions. In normothermic, mild hypothermic and hyperthermic ischemia groups, the levels of MDA and lactate in brain tissue were increased at 24, 48 and 72 h reperfusion following 20-min ischemia as compared with the sham-operated group (P<0.01). The levels of MDA and lactate in mild hypothermic group were significantly lower than those in normothermic group (P<0.01). It is suggested that brain temperature influences the translation of the immunoreactive protein product of c-fos after global cerebral ischemia, and MDA and lactate are also affected by hypothermia and hyperthermia.
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Alzheimer's disease (AD) is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. Abnormal sphingolipid metabolism was reported in AD previously. This study aimed to investigate whether sphK1 could exacerbate the accumulation of amyloid protein (Aβ) and sharpen the learning and memory ability of the animal model of AD using siRNA interference. An adenovirus vector expressing small interfering RNA (siRNA) against the sphK1 gene (sphK1-siRNA) was designed, and the effects of sphK1-siRNA on the APP/PS1 mouse four weeks after treatment with sphK1-siRNA hippocampal injection were examined. SphK1 protein expression was confirmed by using Western blotting and ceramide content coupled with S1P secretion was evaluated by enzyme-linked immunosorbent assay (ELISA). Aβ load was detected by immunohistochemical staining and ELISA. Morris water maze was adopted to test the learning and memory ability of the APP/PS1 mice. A significant difference in the expression of sphK1 protein and mRNA was observed between the siRNA group and the control group. Aβ load in transfected mice was accelerated in vivo, with significant aggravation of the learning and memory ability. The sphK1 gene modulation in the Aβ load and the learning and memory ability in the animal model of AD may be important for the treatment of AD.
Subject(s)
Animals , Mice , Alzheimer Disease , Diagnosis , Therapeutics , Disease Models, Animal , Gene Silencing , Genetic Therapy , Methods , Learning Disabilities , Diagnosis , Therapeutics , Mice, Transgenic , Microinjections , Phosphotransferases (Alcohol Group Acceptor) , Genetics , RNA, Small Interfering , Genetics , Therapeutic Uses , Treatment OutcomeABSTRACT
Alzheimer's disease (AD) is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. Abnormal sphingolipid metabolism was reported in AD previously. This study aimed to investigate whether sphK1 could exacerbate the accumulation of amyloid protein (Aβ) and sharpen the learning and memory ability of the animal model of AD using siRNA interference. An adenovirus vector expressing small interfering RNA (siRNA) against the sphK1 gene (sphK1-siRNA) was designed, and the effects of sphK1-siRNA on the APP/PS1 mouse four weeks after treatment with sphK1-siRNA hippocampal injection were examined. SphK1 protein expression was confirmed by using Western blotting and ceramide content coupled with S1P secretion was evaluated by enzyme-linked immunosorbent assay (ELISA). Aβ load was detected by immunohistochemical staining and ELISA. Morris water maze was adopted to test the learning and memory ability of the APP/PS1 mice. A significant difference in the expression of sphK1 protein and mRNA was observed between the siRNA group and the control group. Aβ load in transfected mice was accelerated in vivo, with significant aggravation of the learning and memory ability. The sphK1 gene modulation in the Aβ load and the learning and memory ability in the animal model of AD may be important for the treatment of AD.
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Objective To investigate the effect of agonist CD40 monoclonal antibody (CD40mAb) on the tolerance of experimental autoimmune myasthenia gravis (EAMG) induced by immature dendritic cells (iDCs). Methods Lewis rats were equally randomized into normal group,EAMG group, tolerance group and CD40mAb treatment group (n=5). Rats in the tolerance group and CD40mAb treatment group were vaccinated with AChR pulsed iDCs; and rats in the CD40mAb treatment group were intraperitoneally injected CD40mAb at a dosage of 0.5 mg once when performing the vaccination and on the 2rd d of vaccination. One mL serum-free medium was given to the rats in the EAMG group; normal group did not receive any treatment. Three weeks after that, rats in the above 4 groups were immunized with AChR and complete Freund's adjuvant (CFA). Seven weeks after the immunization, the corresponding indexes of MG were observed: behavioral assessment was performed and electromyogram was employed to detect the repetitive nerve stimulation on these rats; enzyme-linked immunosorbent assay (ELISA) was used to determine the level of AChRab; the pathological changes of neuromuscular junction were also detected. Results Just as the rats in the normal group, the rats in the tolerance group did not have significant changes in any of the corresponding indexes of MG after being immunized with AChR and CFA. In contrast, rats in both EAMG group and CD40mAb treatment group showed typical changes in the corresponding indexes of MG: their electromyogram wave amplitude obviously attenuated; the level of serum AChRab increased and neuromuscular junction appeared as a typical damage of MG. Conclusion Agonist CD40mAb could abrogate the tolerance of EAMG induced by AChR pulsed iDCs, suggesting that the dysfunction of DCs is related to the priming of abnormal immune of MG.
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<p><b>BACKGROUND</b>The optimal time window for the administration of hypothermia following cerebral ischemia has been studied for decades, with disparity outcomes. In this study, the efficacy of mild brain hypothermia beginning at different time intervals on brain endogenous antioxidant enzyme and energy metabolites was investigated in a model of global cerebral ischemia.</p><p><b>METHODS</b>Forty-eight male Sprague-Dawley rats were divided into a sham-operated group, a normothermia (37°C - 38°C) ischemic group and a mild hypothermic (31°C - 32°C) ischemia groups. Rats in the last group were subdivided into four groups: 240 minutes of hypothermia, 30 minutes of normothermia plus 210 minutes of hypothermia, 60 minutes of normothermia plus 180 minutes of hypothermia and 90 minutes of normothermia plus 150 minutes of hypothermia (n = 8). Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model for 20 minutes and mild hypothermia was applied after 20 minutes of ischemia. Brain tissue was collected following 20 minutes of cerebral ischemia and 240 minutes of reperfusion, and used to measure the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), reduced glutathione (GSH) and adenosine triphosphate (ATP).</p><p><b>RESULTS</b>Mild hypothermia that was started within 0 to 60 minutes delayed the consumption of SOD, GSH-Px, GSH, and ATP (P < 0.05 or P < 0.01) in ischemic tissue, as compared to a normothermic ischemia group. In contrast, mild hypothermia beginning at 90 minutes had little effect on the levels of SOD, GSH-Px, GSH, and ATP (P > 0.05).</p><p><b>CONCLUSIONS</b>Postischemic mild brain hypothermia can significantly delay the consumption of endogenous antioxidant enzymes and energy metabolites, which are critical to the process of cerebral protection by mild hypothermia. These results show that mild hypothermia limits ischemic injury if started within 60 minutes, but loses its protective effects when delayed until 90 minutes following cerebral ischemia.</p>
Subject(s)
Animals , Male , Rats , Adenosine Triphosphate , Metabolism , Antioxidants , Metabolism , Brain Ischemia , Metabolism , Glutathione , Metabolism , Glutathione Peroxidase , Metabolism , Hypothermia, Induced , Rats, Sprague-Dawley , Superoxide Dismutase , Metabolism , TemperatureABSTRACT
<p><b>BACKGROUND</b>Recently, 1,5-dicaffeoylquinic acid (1,5-DQA), a caffeoylquinic acid derivative isolated from Aster scaber, was found to have neuroprotective effects. However, the protective mechanisms of 1,5-DQA have not yet been clearly identified. The purpose of this study was to explore the protective mechanisms of 1,5-DQA on neuronal culture.</p><p><b>METHODS</b>We investigated the neuroprotective effects of 1,5-DQA against amyloid β(1-42) (Aβ(42))-induced neurotoxicity in primary neuronal culture. To evaluate the neuroprotective effects of 1,5-DQA, primary cultured cortical neurons from neonate rats were pretreated with 1,5-DQA for 2 hours and then treated with 40 µmol/L Aβ(42) for 6 hours. Cell counting kit-8, Hoechst staining and Western blotting were used for detecting the protective mechanism. Comparisons between two groups were evaluated by independent t test, and multiple comparisons were analyzed by one-way analysis of variance (ANOVA).</p><p><b>RESULTS</b>1,5-DQA treated neurons showed increased neuronal cell viability against Aβ(42) toxicity in a concentration-dependent manner, both phosphoinositide 3-kinase (PI3K)/Akt and extracellular regulated protein kinase 1/2 (Erk1/2) were activated by 1,5-DQA with stimulating their upstream tyrosine kinase A (Trk A). However, the neuroprotective effects of 1,5-DQA were blocked by LY294002, a PI3K inhibitor, but not by PD98059, an inhibitor of mitogen-activated protein kinase kinase. Furthermore, 1,5-DQA's anti-apoptotic potential was related to the enhanced inactivating phosphorylation of glycogen synthase kinase 3β (GSK3β) and the modulation of expression of apoptosis-related protein Bcl-2/Bax.</p><p><b>CONCLUSION</b>These results suggest that 1,5-DQA prevents Aβ(42)-induced neurotoxicity through the activation of PI3K/Akt followed by the stimulation of Trk A, then the inhibition of GSK3β as well as the modulation of Bcl-2/Bax.</p>
Subject(s)
Animals , Rats , Amyloid beta-Peptides , Pharmacology , Apoptosis , Blotting, Western , Cell Survival , Cells, Cultured , Cinnamates , Pharmacology , Neurons , Cell Biology , Metabolism , Phosphatidylinositol 3-Kinases , Metabolism , Proto-Oncogene Proteins c-akt , Metabolism , Rats, Sprague-Dawley , Signal TransductionABSTRACT
Objective To explore the protective effects of curcumin on dopaminergic cells by inducing the expression of heat shock protein 70 (Hsp70), inhibiting anormal expression and aggregation of α-synuclein and promoting proteasome system to degrade abnormal α-synuclein. Methods The cellular model of Parkinson's disease was induced by rotenone in the rat pheochromocytoma strain (PC12 cells) and curcumin was also employed to intervene the cell expression. Cell viability was assessed by MTT assay and the activity of the 3 hydrolases in proteasome was measured by the method of fluorescent anzyme immunoassay. Western blotting was employed to detect the expressions of Hsp70 and α-synuclein and immunofluorescence was used to observe the expression of Hsp70 and the aggregation of α-synuclein. Results The cell viability and the activity of proteasome in the rotenone group were decreased dramatically; the expression of Hsp70 was slightly increased while the expression and aggregation of α-synuclein was increased significantly as compared with those in other groups (P<0.05). Pretreatmant with 0.5 μmol/L and 1.0 μmol/L curcumin resulted in significantly increased cell viability and activity ofproteasome in PC12 cells after co-incubation with 0.1 μmol/L rotenone for 24 h compared with the rotenone group; the expression of Hsp70 was increased significantly and significantly decreased expression and aggregation of α-synuclein was found (P<0.05). The protective effects of 5.0 μmol/L and 10 μmol/L curcumin against the rotenone-induced injury in PC12 cells decreased apparently; when the curcumin reached 10 μmol/L, the activity of chymotrypsin in proteasome statistically lower than that in the rotenone group; the activity of the other 2 enzymes in proteasome were not significantly different from that in the rotenone group (P>0.05). Conclusion Low concentration of curcumin can induce higher expression of Hsp70 and higher activity of proteasome to inhibit the anormal expression and aggregation of α-synuclein in PC 12 cells, thus it can alleviate the rotenone-induced injury in PC 12 cells.
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Objective To study the neuroprotective effect and the mechanism of carbamylated erythropoietin (CEPO) on ischemic brain injury, and compare it with erythropoietin (EPO). Methods Focal cerebral ischemia/reperfusion models were induced by occlusion of the middle cerebral artery using the intraluminal filament technique. Four groups (control group, EPO 5 μg/kg treatment group, EPO 50μg/kg treatment group and CEPO 50 μg/kg treatment group) were chosen (n=6). The cerebral blood flow was monitored through a Laser-Doppler flow probe. The slices of brain tissue were stained with cresyl-violet and the cerebral volume of infarction and edema was measured by ImageJ software. The apoptotic cells were detected with TUNEL staining. The inducible NO synthase (iNOS) positive cells were observed by immunohistochemistry. Results Compared with the control group, the EPO 50 μg/kg treatment and CEPO 50 μg/kg treatment groups showed significantly decreased infarct and edema volume, and lower scores of national institutes of health stroke scale. The numbers ofiNOS positive cells in the ischemic cortex of the EPO 50 μg/kg treatment and CEPO 50 μg/kg treatment groups were statistically smaller than those of the control group (P＜0.05). The numbers of apoptotic cells in the ischemic cortex ofthe EPO 50 μg/kg treatment and CEPO 50 μg/kg treatment groups ([43.6±10.1] cells,[40.5±9.8] cells) were obviously smaller than those of the control group ([94.2±15.2] cells, P＜0.05).Conclusion Lower dose of EPO (5 μg/kg) has no brain protective effect. Treatment with CEPO 50μg/kg and EPO 50 μg/kg have equal roles in increasing the cerebral blood flow, decreasing the neurological deficit scores and volume of infarct and edema, and boosting the anti-apoptosis by means of inhibiting the expression of iNOS.
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<p><b>OBJECTIVE</b>To introduce the experiences of applying MR to diagnose the imaging characters in chronic injury of the elbows in athletes.</p><p><b>METHODS</b>From September 2005 to May 2008, 40 elbows of 34 athletes, included 21 males and 13 females,aged from 6 to 16 years old, averaged (12.3 +/- 3.1) years were taken axial, saggital and coronal planes MR Imaging.</p><p><b>RESULTS</b>Magnetic resonance imaging showed thickening and effusion of olecranon synovial plicaes, bone marrow edema of lower humeral ossification, radial head, olecranon, ulna coronoid, ulnar collateral ligament trauma in chronic injury of the elbow joint.</p><p><b>CONCLUSION</b>MRI is a susceptible method for the diagnoses of chronic injury of the elbow.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Athletic Injuries , Pathology , Chronic Disease , Elbow Joint , Wounds and Injuries , Magnetic Resonance ImagingABSTRACT
Objective To explore the effect of dendritic cells (DC) modified with transforming growth factor β1 (TGF-β1) gene on the expressions of CD28/CTLA-4:B7 costimulatory molecules in peripheral blood mononuclear cells (PBMC) in the Lewis rats with experimental autoimmune myasthenia gravis (EAMG). Methods Thirty inbreeding line, healthy, female Lewis rats were divided randomly into 6 groups: normal group, EAMG group, DC treatment group, pcDNA3-TGF-β1-DCtreatment group, pcDNA3-DC control group and normal saline group. The rats were immunized with the AChR protein extracted from electric organ of Narcine timilei and CFA in the groups except normal group. 2×106 pcDNA3-TGF-β1-DCs/rat were injected subcutaneously into the backs of the rats which had been immunized 5 d earlier with AChR+CFA. The rats in DC treatment group, pcDNA3-DC control group and normal saline group were injected in parallel with untreated DC, pcDNA3-DC and normal saline, respectively. Seven weeks after the first immunization, the expressions of CD28 mRNA and CTLA-4 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the levels of B7-1 and B7-2 on the surface of PBMC were examined using flow cytometry. Results (1)The low expression of CD28 mRNA and rare expression of CTLA-4 mRNA were found in the normal rats, and both expressions increased markedly in EAMG rats (P＜0.001). Compared to those in EAMG group, the expression of CD28 mRNA decreased and CTLA-4 mRNA was upregulated after the treatment with pcDNA3-TGF-β1-DC (P＜0.05). There was no significant difference in the expressions of CD28 mRNA and CTLA-4 mRNA among the EAMG group, DC treatment group, pcDNA3-DC control group and normal saline group (P＞0.05). (2) The expressions of CD28, CTLA-4, B7-1 and B7-2 on the surface of PBMC were rare in normal rats, which increased significantly in EAMG rats (P＜0.001). The levels of CD28, B7-1 and B7-2 in pcDNA3-TGF-β1-DC group were lower than those in EAMG group (P＜0.01), but the level of CTLA-4 was higher than that in EAMG group (P＜0.05). They showed no statistically difference among the EAMG group, DC treatment group, pcDNA3-DC control group and normal saline group (P＞0.05). Conclusions The expressions of CD28/CTLA-4:B7 costimulatory molecules are abnormal in the rats with EAMG. The regulation of CD28/CTLA-4:B7 costimulatory pathways may play a critical role in the mechanism of the treatment with DC transfected with pcDNA3-TGF-β1 in the incipient EAMG rats.
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<p><b>OBJECTIVE</b>To investigate the protective effects of hydrogen peroxide preconditioning (HPP) on the pheochromocytoma (PC12) cells treated with 1-methyl-4-phenylpyridinium (MPP(+)) and to explore the potential mechanisms.</p><p><b>METHODS</b>The viability and apoptosis of PC12 cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6'-diamidino-2-phenylindole (DAPI) staining, respectively. The expressions of 14-3-3 protein and phosphorylated p38 mitogen-activated protein kinase (MAPK) were determined by Western blot. Enzyme-linked immunosorbent assay (ELISA) was used to measure the activity of extracellular signal-regulated protein kinase 1/2 (ERK1/2).</p><p><b>RESULTS</b>The cell viability decreased and the number of apoptotic cells increased dramatically in MPP(+) group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP(+)-treated PC12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC12 cells induced by HPP.</p><p><b>CONCLUSION</b>HPP protects PC12 cells against MPP(+) toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.</p>
Subject(s)
Animals , Rats , 1-Methyl-4-phenylpyridinium , Toxicity , 14-3-3 Proteins , Apoptosis , Physiology , Blotting, Western , Cell Survival , Enzyme-Linked Immunosorbent Assay , Hydrogen Peroxide , Pharmacology , Mitogen-Activated Protein Kinase 1 , Metabolism , Mitogen-Activated Protein Kinase 3 , Metabolism , Neurons , Metabolism , Pathology , PC12 Cells , Phosphorylation , Signal Transduction , Physiology , Up-Regulation , p38 Mitogen-Activated Protein Kinases , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To evaluate the role of thrombin-activated microglia in the neurodegeneration of nigral dopaminergic neurons in the rat substantia nigra (SN) in vivo.</p><p><b>METHODS</b>After stereotaxic thrombin injection into unilateral SN of rats, immunostaining, reverse transcription polymerase chain reaction (RT-PCR) and biochemical methods were used to observe tyrosine hydroxylase (TH) immunoreactive positive cells, microglia activation, nitric oxide (NO) amount and inducible nitric-oxide synthase (iNOS) expression.</p><p><b>RESULTS</b>(1) Selective damage to dopaminergic neurons was produced after thrombin injection, which was evidenced by loss of TH immunostaining in time-dependent manner; (2) Strong microglial activation was observed in the SN; (3) RT-PCR demonstrated the early and transient expression of neurotoxic factors iNOS mRNA in the SN. Immunofluorescence results found that thrombin induced expression of iNOS in microglia. The NO production in the thrombin-injected rats was significantly higher than that of controls (P < 0.05).</p><p><b>CONCLUSION</b>Thrombin intranigral injection can injure the dopaminergic neurons in the SN. Thrombin-induced microglia activation precedes dopaminergic neuron degeneration, which suggest that activation of microglia and release of NO may play important roles in dopaminergic neuronal death in the SN.</p>
Subject(s)
Animals , Female , Rats , Disease Progression , Dopamine , Encephalitis , Metabolism , Gliosis , Metabolism , Immunohistochemistry , Inflammation Mediators , Toxicity , Injections , Microglia , Metabolism , Nerve Degeneration , Metabolism , Neurons , Metabolism , Pathology , Nitric Oxide , Nitric Oxide Synthase Type II , Metabolism , Oxidative Stress , Physiology , Parkinsonian Disorders , Metabolism , RNA, Messenger , Metabolism , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Substantia Nigra , Metabolism , Thrombin , Toxicity , Time Factors , Tyrosine 3-Monooxygenase , Genetics , Metabolism , Up-Regulation , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>The neuroprotective effect of erythropoietin (EPO) against 1-methyl-4-phenylpyridinium (MPP(+))-induced oxidative stress in cultured PC12 cells, as well as the underlying mechanism, were investigated.</p><p><b>METHODS</b>PC12 cells impaired by MPP(+) were used as the cell model of Parkinson's disease. Methyl thiazolyl tetrazolium (MTT) was used to assay the viability of the PC12 cells exposed to gradient concentrations of EPO, and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay was used to analyze the apoptosis ratio of PC12 cells. The expression of Bcl-2 and Bax in PC12 cells were examined by Western blot, and the reactive oxygen species (ROS), the mitochondrial transmembrane potential and the activity of caspase-3 in each group were detected by spectrofluorometer.</p><p><b>RESULTS</b>Treatment of PC12 cells with MPP(+) caused the loss of cell viability, which may be associated with the elevation in apoptotic rate, the formation of ROS and the disruption of mitochondrial transmembrane potential. It was also shown that MPP(+) significantly induced the upregulation of Bax/Bcl-2 ratio and the activation of caspase-3. In contrast, EPO significantly reversed these responses and had the maximum protective effect at 1 U/mL.</p><p><b>CONCLUSION</b>The inhibitive effect of EPO on the MPP(+)-induced cytotoxicity may be ascribed to its anti-oxidative property and anti-apoptotic activity, and EPO may provide a useful therapeutic strategy for treatment of neurodegenerative diseases such as Parkinson's disease.</p>
Subject(s)
Animals , Rats , 1-Methyl-4-phenylpyridinium , Toxicity , Analysis of Variance , Apoptosis , Caspase 3 , Metabolism , Cell Survival , Dose-Response Relationship, Drug , Drug Interactions , Erythropoietin , Pharmacology , Flow Cytometry , Methods , Herbicides , Toxicity , In Situ Nick-End Labeling , Methods , Membrane Potential, Mitochondrial , Neuroprotective Agents , Pharmacology , PC12 Cells , Proto-Oncogene Proteins c-bcl-2 , Genetics , Metabolism , Reactive Oxygen Species , Metabolism , Tetrazolium Salts , Thiazoles , bcl-2-Associated X Protein , Genetics , MetabolismABSTRACT
Objective To observe the influence of rotenone on the distribution of alpha-synuclein (ASN) in rat model of Parkinson's disease (PD). Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone (s.c.) or sunflower oil (as control group) for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase (TH) or ASN protein was determined by anti-TH or anti-alpha-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum (P < 0.05). In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.
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Objective To investigate the effects of 14-3-3 protein overexpression on the 1-methyl-4-phenylpyridinium (MPP(+)) induced pheochromocytoma (PC12) cell death and the potential mechanisms. Methods pcDNA3.1(+)-14-3-3 plasmids, which could be expressed in mammalian cell, were constructed and transfected into PC12 cells with Lipofectamine 2000. The expression of 14-3-3 protein, Bcl-2 protein, and BAD protein were determined by western blot. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, microplate reader, and flow cytometric analysis were used to measure cell viability, the caspase activity, and apoptotic ratio respectively. Results (1) The expression of 14-3-3 protein increased significantly three weeks after pcDNA3.1 (+)-14-3-3 plasmids transfected into PC12 cells. (2) MPP(+) caused a decrease of cell viability in a dose-dependent manner. At 100 mu mol/L MPP(+), cell viability reduced approximately 50%. (3) The caspase activity increased along with the MPP(+) concentrations rising and reached its maximum value (0.34 mu mol/mg protein) at 100 mu mol/L MPP(+). However caspase activity decreased significantly when the MPP(+) concentration exceeded 100 mu mol/L. (4) Overexpression of 14-3-3 protein decreased the apoptosis ratio of PC12 cells treated with 100 mu mol/L MPP(+) from 26.5% to 8.6%. (5) Bcl-2 protein tended to decrease but BAD protein tended to increase after treatment of PC12 cells with 100 mu mol/L MPP(+). Overexpression of 14-3-3 protein significantly increased the cellular level of Bcl-2 protein and decreased that of BAD protein. Conclusion Overexpression of 14-3-3 protein may reduce MPP(+)-induced apoptotic cell death in PC12 cells by up-regulating the Bcl-2 expression and down-regulating the BAD expression. These results may provide a promising target for treatment of Parkinson' s disease.
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<p><b>OBJECTIVE</b>To study the changes of prodynorphin (PDyn) gene expression and dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) phosphorylation in rats with levodopa-induced dyskinesia (LID), and to explore the mechanism of over-activation in direct pathway mediated by dopamine D₁ receptor.</p><p><b>METHODS</b>Parkinson's disease (PD) rats were received levodopa (10 mg/kg, i.p.) for 28 d to get the LID rats. According to the behavior scale, LID rats were divided into mild (n = 8) and severe (n = 16) groups. On day 29, 8 rats in severe LID group were given an acute intraperitoneal injection of MK-801 (0.1 mg/kg) 15 min before levodopa treatment (MK-801 group, n = 8). The normal rats received same course and dosage of levodopa as the control group (n = 8). Hybridization in situ was used to measure the expression of PDyn mRNA in striatum. Protein and mRNA levels of total DARPP-32 and phospho-Thr-34 DARPP-32 level were measured by immunoblotting and RT-PCR, respectively.</p><p><b>RESULTS</b>The levels of PDyn mRNA and phospho-Thr-34 DARPP-32 increased significantly in LID rats compared with control rats (P < 0.01), and they also increased markedly in severe LID group compared with mild group (P < 0.01).</p><p><b>CONCLUSION</b>Phospho-Thr-34 DARPP-32 level was increased in LID rats, which contributed to the over-activation of direct pathway mediated by dopamine D₁ receptor.</p>
ABSTRACT
<p><b>BACKGROUND</b>Previous studies have indicated that thrombin (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In this study, we explored the effect of TM on the permeability of the blood brain barrier (BBB) and investigated its possible mechanism, aiming at providing a potential target for brain edema therapy after ICHs.</p><p><b>METHODS</b>TM or TM + cathepsin G (CATG) was stereotaxically injected into the right caudate nucleus of Sprague-Dawley rats in vivo. BBB permeability was measured by Evans-Blue extravasation. Brain water content was determined by the dry-wet weight method. Brain microvascular endothelial cells were then cultured in vitro. After TM or TM + CATG was added to the endothelial cell medium, changes in the morphology of cells were dynamically observed by phase-contrast light microscopy, and the expression of matrix metalloproteinase-2 (MMP-2) protein was measured by immunohistochemical method.</p><p><b>RESULTS</b>BBB permeability increased at 6 hours after a TM injection into the ipsilateral caudate nucleus (P < 0.05), peaked between 24 hours (P < 0.01) and 48 hours (P < 0.05) after the injection, and then declined. Brain water content changed in parallel with the changes in BBB permeability. However, at all time points, BBB permeability and brain water content after a TM + CATG injection were not significantly different from the respective parameters in the control group (P > 0.05). TM induced endothelial cell contraction in vitro in a time-dependent manner and enhanced the expression of MMP-2 protein. After incubation with TM + CATG, cell morphology and MMP-2 expression did not change significantly as compared to the control group (P > 0.05).</p><p><b>CONCLUSIONS</b>Increased BBB permeability may be one of the mechanisms behind TM-induced cerebral edema. TM induces endothelial cell contraction and promotes MMP-2 expression by activating protease activated receptor-1 (PAR-1), possibly leading to the opening of the BBB.</p>