Expression changes of microtubule associated protein 1B in the brain of Fmr1 knockout mice

Objective To explore the regulatory effect of fragile X mental retardation protein （FMRP） on the translation of microtubule associated protein 1B （MAP1B）. Methods The expressions of MAP1B protein and MAP1B mRNA in the brains of 1-week and 6-week old fragile X mental retardation-1 （FmrI） knockout （KO） mice were investigated by immunohistochemistry, Western blot, and in situ hybridization, with the age-matched wild type mice （WT） as controls. Results The mean optical density （MOD） of MAP1B was significantly decreased in each brain region in KO6W compared with WT6W, whereas in KO1W, this decrease was only found in the hippocampus and cerebellum. MAP1B in 6-week mice was much less than that in 1-week mice of the same genotype. The results of Western blot and in situ hybridization showed that MAP1B protein and MAP1B mRNA were significantly decreased in the hippocampus of both KO1W and KO6W. Conclusion The decreased MAP1B protein and MAP1B mRNA in the Fmrl knockout mice indicate that FMRP may positively regulate the expression of MAP1B.

Overexpression of vascular endothelial growth factor enhances the neuroprotective effects of bone marrow mesenchymal stem cell transplantation in ischemic stroke

Although bone marrow mesenchymal stem cells(BMSCs)might have therapeutic potency in ischemic stroke,the benefits are limited.The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor(VEGF)on behavioral defects in a rat model of transient cerebral ischemia,which was induced by middle cerebral artery occlusion.VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke.We found that compared with the stroke-only group and the vehicle-and BMSCs-control groups,the VEGF-BMSCs treated animals displayed the largest benefits,as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke.Additionally,VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier,increased the regeneration of blood vessels in the region of ischemic penumbra,and reducedneuronal degeneration surrounding the infarct core.Further mechanistic studies showed that among all transplant groups,VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor.These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available.

T cells promote the regeneration of neural precursor cells in the hippocampus of Alzheimer's disease mice

Alzheimer＇s disease is closely associated with disorders of neurogenesis in the brain, and growing evidence supports the involvement of immunological mechanisms in the development of the disease. However, at present, the role of T cells in neuronal regeneration in the brain is unknown. We injected amyloid-beta 1-42 peptide into the hippocampus of six BALB/c wild-type mice and six BALB/c-nude mice with T-cell immunodeficiency to establish an animal model of Alzhei- mer＇s disease. A further six mice of each genotype were injected with same volume of normal saline. Immunohistochemistry revealed that the number of regenerated neural progenitor cells in the hippocampus of BALB/c wild-type mice was significantly higher than that in BALB/c-nude mice. Quantitative fluorescence PCR assay showed that the expression levels of peripheral T cell-associated cytokines （interleukin-2, interferon-y） and hippocampal microglia-related cyto- kines （interleukin-113, tumor necrosis factor-a） correlated with the number of regenerated neural progenitor cells in the hippocampus. These results indicate that T cells promote hippocampal neurogenesis in Alzheimer＇s disease and T-cell immunodeficiency restricts neuronal regeneration in the hippocampus. The mechanism underlying the promotion of neuronal regeneration by T cells is mediated by an increased expression of peripheral T cells and central microglial cytokines in Alzheimer＇s disease mice. Our findings provide an experimental basis for understanding the role of T cells in Alzheimer＇s disease.

Isolation,cultivation and identification of brain glioma stem cells by magnetic bead sorting

This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening. Furthermore, the proliferation, differentiation and self-renewal biological features of brain glioma stem cells were identified. Results showed that a small number of CD133 positive tumor cells isolated from brain glioma samples survived as a cell suspension in serum-free media and proliferated. Subcultured CD133 positive cells maintained a potent self-renewal and proliferative ability, and expressed the stem cell-specific markers CD133 and nestin. After incubation with fetal bovine serum, the number of glial fibrillary acidic protein and microtubule associated protein 2 positive cells increased significantly, indicating that the cultured brain glioma stem cells can differentiate into astrocytes and neurons. Western blot analysis showed that tumor suppressor phosphatase and tensin homolog was highly expressed in tumor spheres compared with the differentiated tumor cells. These experimental findings indicate that the immunomagnetic beads technique is a useful method to obtain brain glioma stem cells from human brain tumors.

Changes in and effective factors of microtubule associated protein 2 in traumatic neurons

Objective To investigate alterations in the microtubule-associated protein 2 (MAP-2) of neurons in Wistar rats and the effect of nimodipine (Nim), D-2-amino-5-phosphonovaleric acid (D-AP-5) and mild hypothermia on neuronal MAP-2 following fluid percussion injury (FPI).Methods Alterations of MAP-2 in Wistar rat neurons following FPI were measured by a confocal laserscanning microscope using MAP-2 immunofluorescence staining as a MAP-2 indicator.Results MAP-2 immunofluorescence staining was limited to the cell bodies and dendritic compartments of neurons and more intense in dendrites than in cell bodies. The loss of MAP-2 was marked at 3 h posttrauma ( P ＜ 0.01 ), and reached a maximum at 48 h post-trauma. Afterwards, fluorescence recovered partly at 72 h post-trauma. The application of Nim markedly reduced the loss of MAP-2 immunoreectivity within 1 h post-trauma ( P ＜ 0.01 ), and the application of D-AP-5 markedly reduced the loss of MAP-2immunoreactivity within 10 h post-injury ( P ＜ 0.01 ). The application of mild hypothermia decreased the loss of MAP-2 immunoreactivity within 1 h post-injury (P＜ 0.05).Conclusions The partial recovery of fluorescence at 72 h post-trauma indicate that the partial structure of the neuronal microtubules can be repaired by itself. Nim, D-AP-5 and mild hypothermia reduce the degradation of MAP-2 by different mechanisms. The treatment of neuronal cytoskeleton degradation following FPI must employ multiple therapeutic approaches.

Cardiac proteomics reveals the potential mechanism of microtubule associated protein 4 phosphorylation-induced mitochondrial dysfunction

Background:Our previous work suggested that microtubule associated protein 4(MAP4)phosphorylation led to mitochondrial dysfunction in MAP4 phosphorylation mutant mice with cardiomyopathy,but the detailed mechanism was still unknown.Thus,the aim of this study was to investigate the potential mechanism involved in mitochondrial dysfunction responsible for cardiomyopathy.Methods:The present study was conducted to explore the potential mechanism underlying the mitochondrial dysfunction driven by MAP4 phosphorylation.Strain of mouse that mimicked constant MAP4 phosphorylation(S737 and S760)was generated.The isobaric tag for relative and absolute quantitation(iTRAQ)analysis was applied to the heart tissue.Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),and protein-protein interaction(PPI)were all analyzed on the basis of differential expressed proteins(DEPs).Results:Among the 72 cardiac DEPs detected between the two genotypes of mice,12 were upregulated and 60 were downregulated.GO analysis showed the biological process,molecular function,and cellular component of DEPs,and KEGG enrichment analysis linked DEPs to 96 different biochemical pathways.In addition,the PPI network was also extended on the basis of DEPs as the seed proteins.Three proteins,including mitochondrial ubiquitin ligase activator of NF-κB 1,reduced form of nicotinamide adenine dinucleotide(NADH)-ubiquinone oxidoreductase 75 kDa subunit,mitochondrial and growth arrest,and DNA-damage-inducible proteins-interacting protein 1,which play an important role in the regulation of mitochondrial function,may correlate with MAP4 phosphorylationinduced mitochondrial dysfunction.Western blot was used to validate the expression of the three proteins,which was consistent with iTRAQ experiments.Conclusions:These findings revealed that the DEPs caused by MAP4 phosphorylation in heart tissue using iTRAQ technique and may provide clues to uncover the potential mechanism of MAP4 phosphorylation-induced mitochondrial dysfunction.