Journal of molecular neuroscience : MN
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The current research aimed to investigate the role of hypoxia-inducible factor-1α (HIF-1α), aquaporin-4 (AQP-4), and matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) dysfunction and cerebral edema formation in a rat subarachnoid hemorrhage (SAH) model. The SAH model was induced by injection of 0.3 ml fresh arterial, non-heparinized blood into the prechiasmatic cistern in 20 s. Anti-AQP-4 antibody, minocycline (an inhibitor of MMP-9), or 2-methoxyestradiol (an inhibitor of HIF-1α), was administered intravenously at 2 and 24 h after SAH. ⋯ Finally, inhibition of HIF-1α significantly suppressed the level of AQP-4 and MMP-9, which could induce the expression of laminin and tight junction proteins. Our results suggest that HIF-1α plays a role in brain edema formation and BBB disruption via a molecular signaling pathway involving AQP-4 and MMP-9. Pharmacological intervention of this pathway in patients with SAH may provide a novel therapeutic strategy for early brain injury.
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Induction of demyelination in the central nervous system induce the oligodendrocyte progenitors to proliferate, migrate, and differentiate for restoring new myelin sheathes around demyelinated axons. Factors which increase the response of endogenous progenitor cells could be used to improve remyelination. In the current study, the effect of bFGF on lysolecithin-induced demyelination and remyelination processes in mouse optic chiasm and nerves was investigated. ⋯ Lysolecithin decreased MBP and increased Olig2 expression in different days post-lesion. Lysolecithin-induced changes in VEPs were partially ameliorated by endogenous repair. bFGF reduced the increased delay, increased the reduced amplitude of P1-N1 wave, increased MBP gene expression, and accelerated the increasing pattern of Olig2. bFGF seems to be able to potentiate the endogenous repair mechanisms of myelin. Its effect on demyelination and remyelination processes seems to be mediated by oligodendrocyte progenitor cells and their differentiation to myelinating cells.
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Alzheimer disease (AD) is characterized by chronic neuroinflammation, which may lead to dysfunction in neuronal circuits. Although reactive microglia are found in association with accumulation of beta amyloid (Aβ) plaques in the AD brain, their contribution to neuronal cell loss remains speculative. A major genetic risk factor for sporadic AD is inheritance of the apolipoprotein (apo) E4 allele, which has been shown to contribute significantly to neurodegeneration in AD. ⋯ Addition of Aβ(1-40) preincubated with apoE4 to H4 cells in the presence of SNAP led to an additive IL-1β-induced COX-2 expression and PGE(2) production. These observations indicate that increased PGE(2) resulted from increased nitrosative stress, which is enhanced by apoE4. Thus a molecular understanding of the interactions of apoE4 with Aβ, NO and IL-1β on the regulation of the COX-2/prostaglandin pathway may open new avenues in understanding the mechanism of development of neurodegenerative disease such as AD.
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The objective of this study is to investigate the expression and significance of isocitrate dehydrogenase 1 (IDH1) mutation in different subtypes of human gliomas. Direct DNA sequencing, western blot, and immunohistochemistry were used to detect IDH1 mutation and IDH1 gene expression levels in 97 cases of glioma and 9 cases of other CNS tumors. IDH1 mutation was heterozygous, with wild-type arginine 132 replaced by histidine (R132H). ⋯ For example, it can be used to distinguish primary glioblastoma from secondary glioblastoma, combining TP53 mutation and loss of heterozygosity involving 1p/19q. It can also be used as a marker for some gliomas. For example, it can be used to distinguish pilocytic astrocytoma from diffuse astrocytoma, combining detected BRAF proto-oncogene mutations.
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Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor (VEGF) are potent mitogens for endogenous neural stem cells (eNSC) and also induce angiogenesis. We infused the individual factors or their combination into the lateral ventricles of mice for 7 days after traumatic brain injury (TBI) in order to evaluate the effects on functional outcome and on eNSC proliferation and differentiation. The results show that VEGF induced a significant increment in the number of proliferating eNSC in the subventricular zone and in the perilesion cortex and that combination of FGF2 and VEGF did not augment the effects of VEGF alone. ⋯ Combination therapy did not have an additive effect on outcome or neuronal differentiation. In conclusion, FGF2-VEGF combination does not augment neurogenesis and angiogenesis or reduce lesion volumes after TBI compared with individual factors. This may suggest the existence of a ceiling effect for brain regeneration.