RESUMO
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.
RESUMO
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.