A novel transgenic mouse model of Chinese CharcotMarie-Tooth disease type 2L

We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141N HSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the KI41NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141N HSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141N HSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the KI4mHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.

Compound Danshen tablets downregulate amyloid protein precursor mRNA expression in a transgenic cell model of Alzheimer's disease Effects and a comparison with donepezil

After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.

Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models （c-myc/SV40Tag＋/Tet-on＋） to explore the malignant trans- formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cells were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibrillary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibrillary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibrillary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cells. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

Critical thinking of Alzheimer's transgenic mouse model:current research and future perspective

Transgenic models are useful tools for studying the pathogenesis of and drug development for Alzheimer's Disease(AD).AD models are constructed usually using overexpression or knock-in of multiple pathogenic gene mutations from familial AD.Each transgenic model has its unique behavioral and pathological features.This review summarizes the research progress of transgenic mouse models,and their progress in the unique mechanism of amyloid-βoligomers,including the first transgenic mouse model built in China based on a single gene mutation(PSEN1 V97L)found in Chinese familial AD.We further summarized the preclinical findings of drugs using the models,and their future application in exploring the upstream mechanisms and multi-target drug development in AD.

Near infra-red light treatment of Alzheimer's disease

Alzheimers disease(AD)is a chronic neurodegenerative disease.The symptoms include memoryand spatial learning dificulties,language disorders,and loss of motivation,which get worse overtime,eventually ending in death.No ffective treatments are available for AD,currently.Currenttreatments only attenuate symptoms temporarily and are associated with severe side ffects.Nearinfra-red(NIR)light has been studied for a long time.We investigated the effect of NIR on ADusing a transgenic mouse model,which was obtained by co-injecting two vectors carrying ADmutations in amyloid precursor protein(APP)and presenilin-i(PSEN1)into C57BL/6J mice.The irradiation equipment consisted of an accommodating box and an LED array.The wave-length of NIR light emitted from LED was between 1040 nm and 1090 nm.The power densitydelivered at the level of the mice was approximately 15 mW/cm^(2),Firstly,we treated the micewith NIR for 40 days,Then,the irradiation was suspended for 28 days.Finally,another 15 daystreatment was brought to mice.We conducted Morris water maze and immunofluorescenceanalysis to evaluate the effects of treatment.Immunofuorescence analysis was based on mea-suring the quantity of plaques in mouse brain slices,Our results show that NIR light improvesmemory and spatial learning ability and reduces plaques moderately.NIR light represents apotential treatment for AD.

The adjustment of γ-aminobutyric acid_A tonic subunits in Huntington＇s disease：from transcription to translation to synaptic levels into the neostriatum

γ-Aminobutyric acid（GABA）,plays a key role in all stages of life,also is considered the main inhibitory neurotransmitter.GABA activates two kind of membrane receptors known as GABAA and GABAB,the first one is responsible to render tonic inhibition by pentameric receptors containing α4-6,β3,δ,or ρ1-3 subunits,they are located at perisynaptic and/or in extrasynaptic regions.The biophysical properties of GABAA tonic inhibition have been related with cellular protection against excitotoxic injury and cell death in presence of excessive excitation.On this basis,GABAA tonic inhibition has been proposed as a potential target for therapeutic intervention of Huntington＇s disease.Huntington＇s disease is a neurodegenerative disorder caused by a genetic mutation of the huntingtin protein.For experimental studies of Huntington＇s disease mouse models have been developed,such as R6/1,R6/2,Hdh Q92,Hdh Q150,as well as YAC128.In all of them,some key experimental reports are focused on neostriatum.The neostriatum is considered as the most important connection between cerebral cortex and basal ganglia structures,its cytology display two pathways called direct and indirect constituted by medium sized spiny neurons expressing dopamine D1 and D2 receptors respectively,they display strong expression of many types of GABAA receptors,including tonic subunits.The studies about of GABAA tonic subunits and Huntington＇s disease into the neostriatum are rising in recent years,suggesting interesting changes in their expression and localization which can be used as a strategy to delay the cellular damage caused by the imbalance between excitation and inhibition,a hallmark of Huntington＇s disease.

Targeting lactate dehydrogenase A (LDHA) exerts antileukemic effects on T-cell acute lymphoblastic leukemia

Background:T-cell acute lymphoblastic leukemia(T-ALL)is an uncommon and aggressive subtype of acute lymphoblastic leukemia(ALL).In the serum of T-ALL patients,the activity of lactate dehydrogenase A(LDHA)is increased.We proposed that targeting LDHA may be a potential strategy to improve T-ALL outcomes.The current study was conducted to investigate the antileukemic effect of LDHA gene-targeting treatment on T-ALL and the underlying molecular mechanism.Methods:Primary T-ALL cell lines Jurkat and DU528 were treated with the LDH inhibitor oxamate.MTT,colony formation,apoptosis,and cell cycle assays were performed to investigate the effects of oxamate on T-ALL cells.Quantitative real-time PCR(qPCR)and Western blotting analyses were applied to determine the related signaling pathways.A mitochondrial reactive oxygen species(ROS)assay was performed to evaluate ROS production after T-ALL cells were treated with oxamate.A T-ALL transgenic zebrafish model with LDHA gene knockdown was established using CRISPR/Cas9 gene-editing technology,and then TUNEL,Western blotting,and T-ALL tumor progression analyses were conducted to investigate the effects of LDHA gene knockdown on T-ALL transgenic zebrafish.Results:Oxamate significantly inhibited proliferation and induced apoptosis of Jurkat and DU528 cells.It also arrested Jurkat and DU528 cells in G0/G1 phase and stimulated ROS production(all P<0.001).Blocking LDHA significantly decreased the gene and protein expression of c-Myc,as well as the levels of phosphorylated serine/threonine kinase(AKT)and glycogen synthase kinase 3 beta(GSK-3β)in the phosphatidylinositol 3′-kinase(PI3K)signaling pathway.LDHA gene knockdown delayed disease progression and down-regulated c-Myc mRNA and protein expression in T-ALL transgenic zebrafish.Conclusion:Targeting LDHA exerted an antileukemic effect on T-ALL,representing a potential strategy for T-ALL treatment.

CD70 defines a subset of proinflammatory and CNSpathogenic TH1/TH17 lymphocytes and is overexpressed in multiple sclerosis

activation.Therefore,engagement of the costimulatory CD27/CD70 pathway is solely dependent on upregulation of CD70.However,the T cell-intrinsic effect and function of human CD70 remain underexplored.Herein,we describe that CD70 expression distinguishes proinflammatory CD4^(+)T lymphocytes that display an increased potential to migrate into the central nervous system(CNS).Upregulation of CD70 on CD4^(+)T lymphocytes is induced by TGF-β1 and TGF-β3,which promote a pathogenic phenotype.In addition,CD70 is associated with a TH1 and TH17 profile of lymphocytes and is important for T-bet and IFN-γexpression by both T helper subtypes.Moreover,adoptive transfer of CD70−/−CD4^(+)T lymphocytes induced less severe experimental autoimmune encephalomyelitis(EAE)disease than transfer of WT CD4^(+)T lymphocytes.CD70+CD4^(+)T lymphocytes are found in the CNS during acute autoimmune inflammation in humans and mice,highlighting CD70 as both an immune marker and an important costimulator of highly pathogenic proinflammatory TH1/TH17 lymphocytes infiltrating the CNS.