Capillary Zone Electrophoretic Separation of Basic Proteins with Coated Columns Prepared by Sol-Gel Technology

Coated capillary columns were prepared by sol-gel technology and used in the separation of basic proteins with capillary zone electrophoresis. The results indicated that a significant decrease in protein adsorption was obtained and EOF was also diminished to zero in the pH range of 3-10.

Triethylamine or diethylenetriamine as dynamic modifier for suppressing basic protein adsorption in capillary electrophoresis

Either triethylamine or diethylenetriamine can be conveniently used as a dynamic modifier to suppress the adsorption of basic proteins in capillary zone electrophoresis. Sufficiently high column efficiencies (> 2x10(5) plates/m for cytochrome C) were obtained with either of them along with the improvement of the peak shapes and repeatability of migration time. The relationship between the adsorption suppression effect of the modifier and its structure was discussed.

Acupuncture effects on serum myelin basic protein and remyelination following 30 minutes and 2 hours of ischemia in a rat model of cerebral ischemia-reperfusion injury

BACKGROUND： Acupuncture treatment on injured cerebral axons has shown to provide efficacy in clinical practice. It is unknown whether acupuncture produces therapeutic effects by protecting injured cerebral myelin in ischemic stroke. OBJECTIVE： To test whether acupuncture provides protection for injured cerebral myelin, based on quantitative data from cerebral ischemia-reperfusion rats, and to compare the effects of early and late acupuncture on serum myelin basic protein （MBP） content and remyelination of the ischemic internal capsule.DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed at the Neurobiological Laboratory, Sichuan University from March 2005 to March 2006. MATERIALS： ＂Hua Tuo＂ Brand filiform needles were produced by the Medical Instrument Factory of Suzhou, China.METHODS： A total of 52 adult, healthy, male, Sprague Dawley rats were randomly assigned to four groups： control （n = 4）, model （n = 16）, early acupuncture （n = 16）, and late acupuncture （n = 16）. The focal cerebral ischemia-reperfusion model was established by middle cerebral artery occlusion in the right hemisphere using the modified thread embolism method in the latter three groups. Early and late acupuncture groups underwent acupuncture after ischemia for 30 minutes and 2 hours using the Xingnaokaiqiao needling method, respectively. Acupoints were ＂Neiguarf＇ （PC 6） and ＂Sanyinjiao＂ （SP 6） on the bilateral sides, as well as ＂Shuigou＇ （DU 26） and ＂Baihui＂ （DU 20） with stimulation for 1 minute at each acupoint. Acupuncture at all acupoints was performed two or three times while the needle was retained, once per day. No special handling was administered to the control clroup.MAIN OUTCOME MEASURES： For each group, remyelination of the internal capsule was observed by Pal-Weigert＇s myelin staining and serum MBP content was detected using enzyme-linked immunosorbent assay method on days 1,3, 5, and 7 following ischemia-reperfusion injury.RESULTS： Compared with the control group, massive demyelination of the internal capsule occurred, and serum MBP content increased in the model group （P 〈 0.05）. Compared with the model group, the extent of demyelination in the internal capsule was less distinct and serum MBP content was significantly less in the early and late acupuncture group （P 〈 0.01 ）. Compared with the late acupuncture group, serum MBP content reached a peak later and the peak value was less in the early acupuncture group. CONCLUSION： Results suggest that acupuncture exerts a protective effect on injured cerebral myelin in ischemia-reperfusion rats by reducing serum MBP content and promoting remyelination. The study also suggests that the effect of early acupuncture is superior to late acupuncture.

Neuron-specific Enclose and Myelin Basic Protein in Cerebrospinal Fluid of Patients with First Episode Schizophrenia

In order to study whether patients with schizophrenia have cerebral injury, neuron-specific enolase （NSE） and myelin basic protein （MBP）in cerebrospinal fluid （CSF） of 33 patients with first episode schizophrenia and 9 from the control group were determined by double antibody sandwich enzyme immunoassay method. The results showed that there was significant difference in the NSE contents between the experimental group and control group （P〈0.01）. The NSE contents in CSF in the experimental group were positively correlated with MBP in schizophrenia patients （P〈 0.05）. These findings suggested that patients with schizophrenia had cerebral injury.

Analysis of the induction of the myelin basic protein binding to the plasma membrane phospholipid monolayer

Myelin basic protein（MBP） is an essential structure involved in the generation of central nervous system（CNS）myelin.Myelin shape has been described as liquid crystal structure of biological membrane.The interactions of MBP with monolayers of different lipid compositions are responsible for the multi-lamellar structure and stability of myelin.In this paper,we have designed MBP-incorporated model lipid monolayers and studied the phase behavior of MBP adsorbed on the plasma membrane at the air/water interface by thermodynamic method and atomic force microscopy（AFM）.By analyzing the pressure–area（π–A） and pressure–time（π–T） isotherms,univariate linear regression equation was obtained.In addition,the elastic modulus,surface pressure increase,maximal insertion pressure,and synergy factor of monolayers were detected.These parameters can be used to modulate the monolayers binding of protein,and the results show that MBP has the strongest affinity for 1,2-dipalmitoyl-sn-glycero-3-phosphoserine（DPPS） monolayer,followed by DPPC/DPPS mixed and1,2-dipalmitoyl-sn-glycero-3-phospho-choline（DPPC） monolayers via electrostatic and hydrophobic interactions.AFM images of DPPS and DPPC/DPPS mixed monolayers in the presence of MBP（5 n M） show a phase separation texture at the surface pressure of 20 m N/m and the incorporation of MBP put into the DPPC monolayers has exerted a significant effect on the domain structure.MBP is not an integral membrane protein but,due to its positive charge,interacts with the lipid head groups and stabilizes the membranes.The interaction between MBP and phospholipid membrane to determine the nervous system of the disease has a good biophysical significance and medical value.

Effects of diethyldithiocarbamate on myelin basic protein expression in the rat lateral olfactory tract

BACKGROUND： Dithiocarbamates can cause demyelination of axons in the peripheral nervous system. Its derivate, diethyldithiocarbamate, is cytotoxic, and causes olfactory mucosal damage and atrophy of the olfactory bulb. However, it is still unclear whether the myelin sheath of the lateral olfactory tract is affected by diethyldithiocarbamate. OBJECTIVE： To investigate the effects of diethyldithiocarbamate on the myelin sheath of the rat lateral olfactory tract. This was done by examining changes in myelin basic protein expression after diethyldithiocarbamate treatment. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of the Department of Human Anatomy and Neurobiology, Xiangya School of Medicine, Central South University, China from July to November 2007. MATERIALS： A total of 72 Sprague Dawley rats were randomly assigned into a diethyldithiocarbamate group （n = 32）, a solvent control group （n = 32）, and a blank control group （n = 8）. The diethyldithiocarbamate and solvent control groups were separately divided into 3-d, 7-d, 14-d and 28-d survival subgroups, with eight rats in each. Diethyldithiocarbamate （Sigma, USA） and goat anti-myelin basic protein polyclonal antibody （Santa Cruz, USA） were used in this study. METHODS： Rats in the diethyldithiocarbamate and solvent control groups were subcutaneously injected with diethyldithiocarbamate （600 mg/kg） and 0.01 mol/L phosphate buffered saline （600 mg/kg） at the posterior neck, respectively. Rats in the blank control group received no treatment. MAIN OUTCOME MEASURES： Immunohistochemical staining and Western blot assay were used to measure myelin basic protein expression in the rat lateral olfactory tract. RESULTS： Following immunohistochemical staining, myelin basic protein was uniformly distributed in the rat lateral olfactory tract in the blank control and solvent control groups. Western blot assay showed 21.5, 18, 17 and 14 ku positive bands. No significant difference was found in myelin basic protein distribution and blot pattern, in the rat lateral olfactory tract, in the diethyldithiocarbamate group, following immunohistochemical staining and Western blot assay. Myelin basic protein expression gradually decreased at day 3, reached the lowest level at day 7, and gradually increased again at days 14 and 28. CONCLUSION： Demyelination is induced by diethyldithiocarbamate in the rat lateral olfactory tract in an early stage, followed by remyelination at later stages.

Clinical Significance of Serum Myelin Basic Protein in Patients with Severe Acute Pancreatitis

Objective In order to determine serum myelin basic protein (MBP) in patients with severe acute pancreatitis and evaluate its clinical significance. Methods\ Serum MBP was measured in 20 patients with acute hemorrhagic necrotic pancreatitis (AHNP) and in 20 normal subjects by enzyme linked immunoabsorbent assay. Results\ Serum MBP content of AHNP group was significantly higher than that of normal control group (P<0.05). Serum MBP content in patients with pancreatic encephalopathy (PE) was significantly higher than that of those without PE (P<0.05). Conclusion\ ①Serum MBP content in patients with AHNP increased significantly;②Serum MBP content may reflect brain injury and its severity;③The prognosis of AHNP is correlated with its serum MBP content.\;

Piezo1 suppression reduces demyelination after intracerebral hemorrhage

Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.

Association between Alzheimer's disease pathogenesis and early demyelination and oligodendrocyte dysfunction

The APPSwe/PSEN1 dE9（APP/PS1） transgenic mouse model is an Alzheimer＇s disease mouse model exhibiting symptoms of dementia, and is commonly used to explore pathological changes in the development of Alzheimer＇s disease. Previous clinical autopsy and imaging studies suggest that Alzheimer＇s disease patients have white matter and oligodendrocyte damage, but the underlying mechanisms of these have not been revealed. Therefore, the present study used APP/PS1 mice to assess cognitive change, myelin loss, and corresponding changes in oligodendrocytes, and to explore the underlying mechanisms. Morris water maze tests were performed to evaluate cognitive change in APP/PS1 mice and normal C57 BL/6 mice aged 3 and 6 months. Luxol fast blue staining of the corpus callosum and quantitative reverse transcription-polymerase chain reaction（q RT-PCR） for myelin basic protein（MBP） mRNA were carried out to quantify myelin damage. Immunohistochemistry staining for NG2 and qRT-PCR for monocarboxylic acid transporter 1（MCT1） mRNA were conducted to assess corresponding changes in oligodendrocytes. Our results demonstrate that compared with C57 BL/6 mice, there was a downregulation of MBP mRNA in APP/PS1 mice aged 3 months. This became more obvious in APP/PS1 mice aged 6 months accompanied by other abnormalities such as prolonged escape latency in the Morris water maze test, shrinkage of the corpus callosum, upregulation of NG2-immunoreactive cells, and downregulation of MCT1 mRNA. These findings indicate that the involvement of early demyelination at 3 months and the oligodendrocyte dysfunction at 6 months in APP/PS1 mice are in association with Alzheimer＇s disease pathogenesis.

Human bone marrow mesenchymal stem cell transplantation attenuates axonal injury in stroke rats

Previous studies have shown that transplantation of human bone marrow mesenchymal stem cells promotes neural functional recovery after stroke, but the neurorestorative mechanisms remain largely unknown. We hypothesized that functional recovery of myelinated axons may be one of underlying mechanisms. In this study, an ischemia/reperfusion rat model was established using the middle cerebral artery occlusion method. Rats were used to test the hypothesis that intravenous transplantation of human bone marrow mesenchyrnal stem cells through the femoral vein could exert neuroprotective effects against cerebral ischemia via a mechanism associated with the ability to attenuate axonal injury. The results of behavioral tests, infarction volume analysis and immunohistochemistry showed that cerebral ischemia caused severe damage to the myelin sheath and axons. After rats were intravenously transplanted with human bone marrow mesenchymal stem cells, the levels of axon and myelin sheath-related proteins, including microtubule-associated protein 2, myelin basic protein, and growth-associated protein 43, were elevated, infarct volume was decreased and neural function was improved in cerebral ischemic rats. These findings suggest that intravenously transplanted human bone marrow mesenchymal stem cells promote neural function. Possible mechanisms underlying these beneficial effects include resistance to demyelination after cerebral ischemia, prevention of axonal degeneration, and promotion of axonal regeneration.

Oligodendrocyte pathology in fetal alcohol spectrum disorders

The pathology of fetal alcohol syndrome and the less severe fetal alcohol spectrum disorders includes brain dysmyelination.Recent studies have shed light on the molecular mechanisms underlying these white matter abnormalities.Rodent models of fetal alcohol syndrome and human studies have shown suppressed oligodendrocyte differentiation and apoptosis of oligodendrocyte precursor cells.Ethanol exposure led to reduced expression of myelin basic protein and delayed myelin basic protein expression in rat and mouse models of fetal alcohol syndrome and in human histopathological specimens.Several studies have reported increased expression of many chemokines in dysmyelinating disorders in central nervous system,including multiple sclerosis and fetal alcohol syndrome.Acute ethanol exposure reduced levels of the neuroprotective insulin-like growth factor-1 in fetal and maternal sheep and in human fetal brain tissues,while ethanol increased the expression of tumor necrosis factor α in mouse and human neurons.White matter lesions have been induced in the developing sheep brain by alcohol exposure in early gestation.Rat fetal alcohol syndrome models have shown reduced axon diameters,with thinner myelin sheaths,as well as reduced numbers of oligodendrocytes,which were also morphologically aberrant oligodendrocytes.Expressions of markers for mature myelination,including myelin basic protein,also were reduced.The accumulating knowledge concerning the mechanisms of ethanol-induced dysmyelination could lead to the development of strategies to prevent dysmyelination in children exposed to ethanol during fetal development.Future studies using fetal oligodendrocyte-and oligodendrocyte precursor cell-derived exosomes isolated from the mother's blood may identify biomarkers for fetal alcohol syndrome and even implicate epigenetic changes in early development that affect oligodendrocyte precursor cell and oligodendrocyte function in adulthood.By combining various imaging modalities with molecular studies,it may be possible to determine which fetuses are at risk and to intervene therapeutically early in the pregnancy.

Treatment with acetyl-L-carnitine exerts a neuroprotective effect in the sciatic nerve following loose ligation:a functional and microanatomical study

Peripheral neuropathies are chronic painful syndromes characterized by allodynia,hyperalgesia and altered nerve functionality.Nerve tissue degeneration represents the microanatomical correlate of peripheral neuropathies.Aimed to improve the therapeutic possibilities,this study investigated the hypersensitivity and the neuromorphological alterations related to the loose ligation of the sciatic nerve in rats.Effects elicited by treatment with acetyl-L-carnitine（ALCAR） in comparison to gabapentin were assessed.Axonal injury,reduction of myelin deposition and accumulation of inflammatory cells were detected in damaged nerve.A decrease of phosphorylated 200-k Da neurofilament（NFP） immunoreactivity and a redistribution in small clusters of myelin basic like-protein（MBP） were observed in ipsilateral nerves.Treatment with ALCAR（100 mg/kg intraperitoneally-i.p.） and gabapentin（70 mg/kg i.p.） administered bis in die for 14 days induced a significant pain relieving effect.ALCAR,but not gabapentin,significantly countered neuromorphological changes and increased axonal NFP immunoreactivity.These findings indicate that both ALCAR and gabapentin significantly decreased the hypersensitivity related to neuropathic lesions.The observation of the positive ALCAR effect on axonal and myelin sheath alterations in damaged nerve supports its use as neurorestorative agent against neuropathies through mechanism（s） consistent to those focused in this study.

Aminooxyacetic acid improves learning and memory in a rat model of chronic alcoholism

Chronic alcoholism seriously damages the central nervous system and leads to impaired learning and memory.Cell damage in chronic alcoholism is strongly associated with elevated levels of hydrogen sulfide（H2S） and calcium ion overload.Aminooxyacetic acid is a cystathionine-β-synthase activity inhibitor that can reduce H2S formation in the brain.This study sought to observe the effect of aminooxyacetic acid on learning and memory in a chronic alcoholism rat model.Rats were randomly divided into three groups.Rats in the control group were given pure water for 28 days.Rats in the model group were given 6% alcohol for 28 days to establish an alcoholism rat model.Rats in the aminooxyacetic acid remedy group were also given 6% alcohol for 28 days and were also intraperitoneally injected daily with aminooxyacetic acid（5 mg/kg） from day 15 to day 28.Learning and memory was tested using the Morris water maze test.The ultrastructure of mitochondria in the hippocampus was observed by electron microscopy.H2S levels in the hippocampus were measured indirectly by spectrophotometry,and ATPase activity was measured using a commercial kit.The expression of myelin basic protein was determined by immunohistochemistry and western blotting.Compared with the control group,latency and swimming distance were prolonged in the navigation test on days 2,3,and 4 in the model group.In the spatial probe test on day 5,the number of platform crosses was reduced in the model group.Cristae cracks,swelling or deformation of mitochondria appeared in the hippocampus,the hippocampal H2S level was increased,the mitochondrial ATPase activity was decreased,and the expression of myelin basic protein in the hippocampus was down-regulated in the model group compared with the control group.All the above indexes were ameliorated in the aminooxyacetic acid remedy group compared with the model group.These findings indicate that aminooxyacetic acid can improve learning and memory in a chronic alcoholism rat model,which may be associated with reduction of hippocampal H2S level and mitochondrial ATPase activity,and up-regulation of myelin basic protein levels in the hippocampus.

HIGH LEVELS OF MYELIN ANTIGEN AUTOREACTIVE T CELL RESPONSES IN BLOOD AND CEREBROSPINAL FLUID IN PATIENTS WITH ALZHEIMER'S DISEASE

The participation of immune mechanisms in the pathogenesis of dementia of Alzheimer type (AD) has been suggested. We examined T cell responses to myelin basic protein (MBP) and myelin proteolipid protein (PLP) using an enzyme linked immunospot (ELISPOT) assay by enumerating mononuclear cells (MNC) that in blood and cerebrospinal fluid (CSF) secreted the cytokine interferon γ (IFN γ) spontaneously and after short time culture of the cells in presence of MBP or PLP. These myelin components are supposed to induce autoaggressive immunity in multiple sclerosis. MBP and PLP reactive IFN γ secreting cells were detected in patients with AD and, for comparison, in patients with other non inflammatory neurological diseases(OND) and patients with tension type headache (TH). Elevated levels of MBP and PLP reactive IFN γ secreting cells were found in blood in AD patients compared to OND and TH, such cells in AD patients were further enriched in CSF. Levels of MBP reactive as well as spontaneously IFN γ secreting cells in CSF were about 180 fold and 250 fold higher than in blood of AD patients, and also higher than the corresponding data in OND(30 fold and 20 fold) and in TH (120 fold and 20 fold). It is unclear whether the autoreactive T cell responses to MBP and PLP, especially accumulated in CSF, have any importance for the pathogenesis of AD.

Effect of dexamethasone by local treatment on cerebral edema and serum myelin basic protein after brain injury in rabbits

To explore the effect of dexamethasone by local treatment on cerebral edema and brain damage after brain injury. Methods: Twenty-two rabbits were classified into 2 groups, Group A (the control group, n=11) and Group B (the treated group, n=11). An rabbit brain contusion model was made by bone windowplasty by extradural hitting. Group B was treated by local infiltrating and spraying of dexamethasone at equidistance to lesions. Group A was given normal saline in the same way as Group B. The changes of moisture in brain tissues and serum myelin basic protein (MBP) were observed. Results: The percentage of water content in damaged hemisphere in Group A and Group B was 81.75 %± 0.56 % and 79.45 %± 0.52 % respectively. There was a significant difference between the 2 groups (P< 0.05 ). The normal level of MBP was 1.66 μg/L± 0.71 μg/L, while the value of MBP in Group A and Group B were 5.98 μg/L± 2.08 μg/L and 3.15 μg/L± 1.09 μg/L separately. The level of MBP in Group A and Group B were higher than normal level and there was also a significant difference between Group A and Group B (P< 0.05 ). Conclusions: The results of our study showed that the brain moisture and MBP in serum were increased after brain injury while reduced after treatment with dexamethasone. It is demonstrated that local treatment of brain injury with dexamethasone has an obvious therapeutic effect on cerebral edema and serum MBP.

Effect of nerve growth factor on changes of myelin basic protein and functional repair of peripheral nerve following sciatic nerve injury in rats

Objective: To investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury. Methods: The sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD 4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.Results: The latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P< 0.05 ). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP positive cells in the Group A than in the Group B in one and four weeks respectively.Conclusions: NGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.

Could Intrathymic Injection of Myelin Basic Protein Suppress Inflammatory Response After Co-culture of T Lymphocytes and BV-2 Microglia Cells？

Background： The interaction between activated microglia and T lymphocytes can yield abundant pro-inflammatory cytokines. Our previous study proved that thymus immune tolerance could alleviate the inflammatory response. This study aimed to investigate whether intrathymic injection of myelin basic protein （MBP） in mice could suppress the inflammatory response after co-culture ofT lymphocytes and BV-2 microglia cells. Methods： Totally, 72 male C57BL/6 mice were randomly assigned to three groups （17 - 24 in each）： Group A： intrathymic injection of 100 μl M BP （1 mg/ml）; Group B： intrathymic injection of 100 μ1 phosphate-buffered saline （PBS）; and Group C： sham operation group. Every eight mice in each group were sacrificed to obtain the spleen at postoperative days 3, 7, and 14, respectively. T lymphocytes those were extracted and purified from the spleens were then co-cultured with activated BV-2 microglia cells at a proportion of 1：2 in the medium containing MBP for 3 days. After identified the T lymphocytes by CD3, surface antigens oft lymphocytes （CD4, CD8, CD152, and CD154） and BV-2 microglia cells （CD45 and CD54） were detected by flow cytometry. The expressions of pro-inflammatory factors of BV-2 microglia cells （interleukin [1L]- 1β, tumor necrosis factor-o~ [TNF-α], and inducible nitric oxide synthase [iNOS]） were detected by quantitative real-time polymerase chain reaction （PCR）. One-way analysis of variance （ANOVA） and the least significant difference test were used for data analysis. Results： The levels of CD152 in Group A showed an upward trend from the 3rd to 7th day, with a downward trend from the 7th to 14th day （20.12 ± 0.71%, 30.71 ± 1.14%, 13.50 ± 0.71% at postoperative days 3, 7, and 14, respectively, P 〈 0.05）. The levels of CD 154 in Group A showed a downward trend from the 3ra to 7th day, with an upward trend from the 7th to 14th day （1 0.00± 0.23%, 5.28 ±0.69%, 14.67 ± 2.71% at postoperative days 3, 7, and 14, respectively, P 〈 0.05）. The ratio ofCD4＋/CD8 ＋ T in Group A showed a downward trend from the 3rd to 7th day, with the minimum at postoperative day 7, then an upward trend from the 7th to 14th day （P 〈 0.05）. Meanwhile, the levels of CD45 and CD54 in Group A were found as the same trend as the ratio of CD4＋/CD8 ＋ T （CD45：83.39 ± 2.56%, 82.74± 2.09%, 87.56 ± 2. 11%： CD54：3.80 ± 0.24%, 0.94 ± 0.40%, 3.41 ± 0.33% at postoperative days 3, 7, and 14, respectively, P 〈 0.05）. The expressions of TNF-α, IL- 1 β, and iNOS in Group A were significantly lower than those in Groups B and C, and the values at postoperative day 7 were the lowest compared with those at postoperative days 3 and 14 （P 〈 0.05）. No significant difference was found between Groups B and C. Conclusions： l ntrathymic injection of MBP could suppress the immune reaction that might reduce the secondary immune injury of brain tissue induced by an inflammatory response.

A thermodynamic investigation on the binding of mercury ion with myelin basic protein at different temperatures

A thermodynamic study on the interaction of myelin basic protein with mercury ion was studied by using isothermal titration calonmetry,ITC,at 300.15,310.15 and 320.15 K in Tris buffer solution at pH 7.The enthalpies of MBP ＋ Hg^（2＋） interaction are reported and analysed in terms of the extended solvation model.It was found that MBP has two identical and non-cooperative binding sites for Hg^（2＋） ions.The intrinsic dissociation equilibrium constants are 99.904,112.968 and 126.724μmol/L,and the molar enthalpy of binding are -11.634,-10.768 and -10.117kJ mol^（-1） at 300.15,310.15 and 320.15 K,respectively.

Protective effect of Tanreqing injection on axon myelin damage in the brain of mouse model for experimental autoimmune encephalomyelitis

OBJECTIVE: To evaluate the effect of Tanreqing injection on axon myelin in the mouse brain of experimental autoimmune encephalomyelitis(EAE).METHODS: An EAE model was established by myelin oligodendrocyte glycoprotein(MOG)35-55 immunization in C57BL/6 mice. Mice were randomly divided into the following groups: normal, model,prednisone acetate(PA)(6 mg/kg), Tanreqing high dose(5.14 m L/kg), Tanreqing low dose(2.57 m L/kg). On the day of immunization, both Tanreqing groups were treated by intraperitoneal injection,with the PA group treated by intragastrical perfusion after T cell response, and the other groups treated with saline. Changes in body weight, neurological deficit score, incidence rate, mortality rate,and course of disease were observed for all mice.Brain tissue was isolated and stained with hematoxylin-eosin, and pathological investigations performed to evaluate axon myelin damage by transmission electron microscopy(TEM). Myelin basic protein and microtubule associated protein-2 were analyzed by immunohistochemistry.RESULTS: Tanreqing injection significantly prolonged EAE latency and decreased the neurological deficit score, alleviated infiltration of inflammatory cells in the focus area, up-regulated hippocampal MBP expression at the acute stage and the remission stage, and increased microtubule associated protein-2 expression in the EAE brain to varying degrees in the acute stage. TEM analysis indicated that Tanreqing injection alleviates myelin damage in the EAE mouse and maintains the integrity of circular layer structures and alleviates axon mitochondrial swelling.CONCLUSION: Tanreqing injection alleviates EAE symptoms.

Further Analysis of the Function of AtBHLH29 in Regulating the Iron Uptake Process in Arabidopsis thaliana

Using T-DNA insertion and chemical mutants, two recent studies have shown that AtBHLH29, encoding a putative basic helix-loop-helix （BHLH） protein, is involved in regulating the iron uptake process in Arabidopsis thaliana. Herein, we report that RNA interference （RNAi） mutants can be used to reveal more accurately the genetic function of AtBHLH29. We compared the iron deficiency responses of seven RNAi strains that contained decreasing amounts of AtBHLH29transcripts. Under high iron conditions （50 μmol/L iron）, only in the most severe RNAi strains （R101, R111, and R119） was plant growth significantly retarded. However, these mutants could still survive and produce seeds. This suggests that the function of AtBHLH29 is beneficial, but not absolutely essential, to plant growth when iron supply is not limiting. Under low iron conditions （less than 10 μmol/L iron）, the Rlll and R119 strains died prematurely, demonstrating that AtBHLH29 is absolutely necessary for plant survival when iron supply is restricted. The transcription of AtBHLH29 was essential for the expression of AtFRO2 （encoding the ferric chelate reductase）. In contrast, the expression of AtlRT1 （encoding the high-affinity iron transporter） was not so strongly dependent upon the transcription of AtBHLH29. By transient expression, we found that the AtBHLH29-GUS fusion protein was targeted specifically to the nucleus in plant cells. Interestingly, the nuclear localization of AtBHLH29-GUS was abolished when the four consecutive arginine residues located in the basic region of the putative AtBHLH29 protein were replaced by alanine residues by mutagenesis. The implications of our findings on further studies of the mechanism underlying the function of AtBHLH29 are discussed.