Therapeutic efficacy of novel memantine nitrate MN-08 in animal models of Alzheimer's disease and vascular dementia / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)and vascular dementia(VD)are the primary causes of dementia in elderly individuals,and therapeutic options for both conditions are limited.Overactivation of N-methyl-D-aspartate(NMDA)receptors,decreased cerebral blood flow,and subsequent pathological events,play signifi-cant roles in the progression of AD and VD.METHODS In this study,we investigated the therapeutic effects and underlying mechanisms of MN-08,a novel memantine nitrate,in mouse models of AD and rats with VD.RESULTS MN-08 was found to inhibit Aβ accumulation,prevent neuronal and dendritic spine loss,and attenuate cognitive deficits in 2-month-old APP/PS1 transgenic mice(following a 6-month preventative course)and in 8-month-old triple-transgenic(3×Tg-AD)mice(following a 4-month therapeutic course),as well as in rat models of VD with preventive and therapeutic treatments.In vitro,MN-08 was shown to bind to and antagonize NMDA receptors,inhibit calcium influx,and reverse dysregula-tions of the ERK and PI3K/Akt/GSK3β pathway,subse-quently preventing glutamate-induced neuronal loss.Additionally,MN-08 exhibited favorable pharmacokinet-ics,blood-brain barrier penetration,and safety profiles in rats and beagle dogs.CONCLUSION These findings suggest that the novel memantine nitrate MN-08 may be a useful therapeutic agent for AD and VD.

TBN improves motor function and prolongs survival in SOD1G93A and TDP-43M337V mouse model of ALS / 中国药理学与毒理学杂志

OBJECTIVE Amyotrophic lateral sclerosis(ALS)is a fetal neurodegenerative disease characterized by the progressive loss of upper and lower motor neu-rons,leading to skeletal muscle atrophy,weakness,and paralysis.Oxidative stress plays a crucial role in ALS pathogenesis,including the familial forms of the disease arising from mutations in the gene coding for superox-ide dismutase(SOD1).Additionally,the abnormal accu-mulation of TAR DNA-binding protein of 43 ku(TDP-43)is a pathological feature present in almost all patients,even though the pathogenesis of ALS is unclear.Current-ly,there is no drug that can cure ALS/FTLD.Tetramethyl-pyrazine nitrone(TBN)is a derivative of tetramethylapyr-azine,derived from traditional Chinese medicine Ligusti-cum chuanxiong,which has been extensively proven to have therapeutic effects on various models of neurode-generative diseases.METHODS We investigated the therapeutic effect of TBN in the SOD1G93A and TDP-43M337V ALS mouse models.In the SOD1G93A trans-genic mouse model,TBN was administered to mice via intraperitoneal or intragastric injection after the onset of motor deficits.We injected the TDP-43M337V virus into the striatum of mice unilaterally and bilaterally,and then administered TBN 30 mg·kg-1 intragastrically to observe changes in behavior and survival rate of mice.RESULTS TBN slowed the progression of motor neuron disease,as evidenced by improved motor performance,reduced spi-nal motor neuron loss and associated glial response,and decreased skeletal muscle fiber denervation and fibrosis.TBN treatment activated mitochondrial antioxidant activity through the PGC-1α/Nrf2/HO-1 pathway and decreased the expression of human SOD1.In the mice with unilateral injection of TDP-43M337V into the striatum,TBN improved motor deficits and cognitive impairment in the early stages of disease progression.In mice with bilateral injection of TDP-43M337V into the striatum,TBN not only improved motor function but also prolonged survival.Moreover,we demonstrate that its therapeutic effect may be through activation of the Akt/mTOR/GSK-3β and AMPK/PGC-1α/Nrf2 signaling pathways.CONCLUSION TBN shows promise as an agent for the treatment of ALS/FTLD.TBN is currently undergoing clinical investigation for several indications,including a Phase Ⅱ trial for ALS.

Memantine Improves Cognitive Function and Alters Hippocampal and Cortical Proteome in Triple Transgenic Mouse Model of Alzheimer's Disease

Memantine is a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist clinically approved for moderate-to-severe Alzheimer's disease (AD) to improve cognitive functions. There is no report about the proteomic alterations induced by memantine in AD mouse model yet. In this study, we investigated the protein profiles in the hippocampus and the cerebral cortex of AD-related transgenic mouse model (3×Tg-AD) treated with memantine. Mice (8-month) were treated with memantine (5 mg/kg/bid) for 4 months followed by behavioral and molecular evaluation. Using step-down passive avoidance (SDA) test, novel object recognition (NOR) test and Morris water maze (MWM) test, it was observed that memantine significantly improved learning and memory retention in 3xTg-AD mice. By using quantitative proteomic analysis, 3301 and 3140 proteins in the hippocampus and the cerebral cortex respectively were identified to be associated with AD abnormalities. In the hippocampus, memantine significantly altered the expression levels of 233 proteins, among which PCNT, ATAXIN2, TNIK, and NOL3 were up-regulated, and FLNA, MARK 2 and BRAF were down-regulated. In the cerebral cortex, memantine significantly altered the expression levels of 342 proteins, among which PCNT, PMPCB, CRK, and MBP were up-regulated, and DNM2, BRAF, TAGLN 2 and FRY1 were down-regulated. Further analysis with bioinformatics showed that memantine modulated biological pathways associated with cytoskeleton and ErbB signaling in the hippocampus, and modulated biological pathways associated with axon guidance, ribosome, cytoskeleton, calcium and MAPK signaling in the cerebral cortex. Our data indicate that memantine induces higher levels of proteomic alterations in the cerebral cortex than in the hippocampus, suggesting memantine affects various brain regions in different manners. Our study provides a novel view on the complexity of protein responses induced by memantine in the brain of AD.

Assessment of Neuronal Viability Using Fluorescein Diacetate-Propidium Iodide Double Staining in Cerebellar Granule Neuron Culture.

Primary cultured Cerebellar Granule Neurons (CGNs) have been widely used as an in vitro model in neuroscience and neuropharmacology research. However, the co-existence of glial cells and neurons in CGN culture might lead to biases in the accurate assessment of neuronal viability. Fluorescein diacetate (FDA) and Propidium Iodide (PI) double staining has been used to measure cell viability by simultaneously evaluating the viable and dead cells. We used FDA-PI double staining to improve the sensitivities of the colorimetric assays and to evaluate neuronal viability in CGNs. Furthermore, we added blue fluorescent DNA stains (e.g., Hoechst) to improve the accuracy. This protocol describes how to improve the accuracy of assessment of neuronal viability by using these methods in CGN culture. Using this protocol, the number of glial cells can be excluded by using fluorescence microscopy. A similar strategy can be applied to distinguish the unwanted glial cells from neurons in various mixed cell cultures, such as primary cortical culture and hippocampal culture.

Effect of rasagiline on neuroprotection and behavior improvement in MPTP-induced acute mouse model of Parkinson′s disease / 中国药科大学学报

@#This study aimed at investigating the neuroprotective effect and behavior improvement of rasagiline on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine(MPTP)model mice of Parkinson′s disease. The tyrosine hydroxylase(TH)-positive dopaminergic neurons in substantia nigra were observed by immunocytochemistry. HPLC-ECD was used to detect the dopamine and its metabolite levels. Western blot was used to examine the protein expression of TH. The results showed that the mice appeared a series of acute behavior change after the injection of MPTP. Rasagiline(20 mg/kg)exerted significant protection against MPTP-induced loss of TH-positive dopaminergic neurons. The TH-positive neurons in rasagiline-treated mice brain increased significantly compared with those of MPTP-treated group. Rasagiline also enhanced dopamine and its metabolite levels in striatum significantly. In conclusion, rasagiline has protective effect on the acute mouse model of MPTP-induced Parkinsonism.

Effects of new drug T-006 on improving learning and memory abilities in scopolamine-induced dementia Kunming mice / 中国药理学通报

Aim ToexploretheeffectsofnewdrugT-006 on improving learning and memory abilities in scopolamine-induced dementia mice and its possible mechanism.Methods 72maleKunmingmicewere randomly divided into six groups:normal control group,model group,donepezil treatment group,T -006 treatment group with different doses(1,3 and 10 mg·kg-1 ).All mice were treated by intragastric ad-ministration for 14 consecutive days. Learning and memory abilities were tested by a five-day Morris water maze trial from the 1 1 th day.the first 4 days of the five-day Morris water maze,the navigation test was performed,the last day of Morris water maze is the spatial probe test.During the navigation test, mice were intraperitoneally given 2 mg · kg-1 scopolamine 20 minutes before entering the water,while normal control group mice administrated with sterile saline in-stead.Mice were not given T-006 nor scopolamine in spatial probe test.After Morris water maze,all mice were sacrificed for hippocampus and cortex.The activi-ties of AchE and SOD and the levels of GSH and MDA in hippocampus and cortex were measured after tissue harvesting.Results Comparedwithmodelgroup,T-006 could obviously improve learning and memory abil-ities in scopolamine-induced mice, significantly in-crease the levels of SOD and GSH and decrease the levelsofMDAandAchE.Conclusion T-006can significantly improve cognitive abilities in scopolamine-induced dementia mice,and its relevant mechanism may be closely related to its antioxidative effect and the ability to decrease AchE level.

Effects and mechanisms of chloro-oxime derivatives on spatial learning and memory dysfunction in two dementia animal models / 中国药理学通报

Aim To explore the effects and mecha-nisms of choro-oxime derivatives on spatial learning and memory impairment in Kunming mice and SD rats induced by scopolamine and Aβ1-42 , respectively. Methods 40 Kunming mice were randomly divided into 5 groups: control group, model group, donepezil treatment group, arimoclomol treatment group and TCO-2 treatment group. There were 8 mice in each group. Mice of control group were established by intra-peritoneal injection of saline, and mice of other groups were injected with scopolamine and caused memory im-pairment. Both control group and model group were treated with solvent by intraperitoneal administration;donepezil treatment group received donepezil by intra-gastric administration; arimoclomol treatment group and TCO-2 treatment group were given the correspond-ing drugs by abdominal injection, respectively. The solvent and drugs were given at the same time every morning for 8 days. Spatial learning and memory abili-ty were tested by Morris water maze from the fifth day of the drugs administration. 40 SD rats were divided into 5 groups the same as the dementia model men-tioned above. Mice of control group were established by intracerebroventricular injection of saline, and mice of other groups were injected with insoluble Aβ1-42 to be induced of memory impairment. Solvent and drugs were also delivered as mentioned above. Morris water maze was carried out from the fifth day of the drug de-livery. After that, acetyl cholinesterase activity of hip-pocampus was tested with acetyl cholinesterase reagent kit; the content of Aβ1-42 in hippocampus was meas-ured by ELISA assay kit;the expression of phosphoryl-ated tau proteins was detected by Western Blot. Re-sults In both two dementia models, choro-oxime de-rivatives could improve the spatial learning and memory ability, shorten the escape latency and increase the times of crossing the former platform. Choro-oxime de-rivatives could also inhibit the acetyl cholinesterase ac-tivity in animal brain, decrease the concentration of Aβ1-42 and the expression of phosphorylated tau pro-teins in the dementia rats’ hippocampus. Conclusions Spatial learning and memory deficits induced by sco-polamine and Aβ1-42 could be reversed by choro-oxime derivatives. It may be concerned with enhancement of the cholinergic system functions and reduction of the levels of Aβ1-42 and phosphorylated tau proteins in the brain.

Research progress in characterizing multiple-target mechanisms of novel anti-Alzheimer's dimers / 中国药理学通报

Alzheimer's disease ( AD ) is a complex disease caused by environmental and genetic factors. Therefore, one-drug-multiple-target compounds represent the most promising pharmacological approaches to preventing and treating this dis-ease. We have previously designed and synthesized bis( n)-Cog-nitin, novel anti-Alzheimer's dimers derived from tacrine. Bis ( n)-Cognitin have been proven to act on multiple important AD targets, including acetylcholinesterase, β-secretase, N-methyl-D-aspartic acid receptor and neuronal nitric oxide synthase, con-currently. Moreover, Bis(n)-Cognitin could inhibit β-amyloid-induced neurotoxicity, decrease glutamate-induced excitotoxici-ty, reduce oxidative stress, improve learning and memory, and protect against neuronal apoptosis in various in vitro and in vivo models, suggesting that bis ( n )-Cognitin are potential anti-AD drug candidates.

Study on cross-reactivity of allergens between shrimps and crabs / 中国免疫学杂志

Objective:To explore the mechanism for the immune cross-reaction between crabs and shrimps.Methods:The cross-reactivity between shrimps and crabs was observed by inhibition of ELISA and Western blot.Results:The protein constituents were similar where their genus relationship was closer in shrimps and crabs.There were the same bands at 20,36,38,44,68,75,and 85 kD of molecule weight.The protein at 36 kD was the main allergen for shrimps and the proteins at 36,66 and 85 kD were the main allergens for crabs.S.serrata and M.nipponense could inhibit the allergic response of various kinds of shrimp and crab in a concentration-dependent pattern.Conclusion:There is a strong immune cross-reaction between different species of shrimp and crab in 36 000.