Aim of studyMutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) gene were recently discovered in vast majority of World Health Organization (WHO) grade II/III gliomas. This study is to understand the effects of IDH1 R132H mutation in gliomagenesis and to develop new strategies to treat glioma with IDH1 R132H mutation.Materials and methodsOver expression of IDH1 R132H in U87MG cells was done by transfecting cells with IDH1 R132H plasmid. MTT assay, scratch repair assay and western blot were performed to study effects of IDH1 R132H mutation on cell proliferation, migration, regulating AKT-mTOR signaling pathway and cell death respectively. NADP+/NADPH and GSH quantification assays were performed to evaluate effects of IDH1 R132H mutation on the production of antioxidant NADPH and GSH.ResultsWe found that over expression of IDH1 R132H mutation decreased cell proliferation consistent with previous reports; however, it increased cell migration and enhanced AKT-mTOR signaling pathway activation. Mutations in isocitrate dehydrogenase (IDH) 1 also change the function of the enzymes and cause them to produce 2-hydroxyglutarate and not produce NADPH. We tested the level of NADPH and GSH and demonstrated that IDH1 R132H mutant stable cells had significantly low NADPH and GSH level compared to control or IDH1 wild type stable cells. The reduced antioxidants (NADPH and GSH) sensitized U87MG cells with IDH R132H mutant to 5-FU treatment.ConclusionOur study highlights the important role of IHD1 R132H mutant in up- regulating AKT-mTOR signaling pathway and enhancing cell migration. Furthermore, we demonstrate that IDH1 R132H mutation affects cellular redox status and sensitizes gliomas cells with IDH1 R132H mutation to 5FU treatment.

The study of the genes that are related to the pathogenesis of Parkinson's disease (PD) will improve our understanding of the mechanisms that underlie the development of PD. α-Synuclein is a major protein component of Lewy bodies, which are characteristic structures of PD pathology. Mutations in α-synuclein are closely related to the early onset of autosomal dominant PD. Transgenic flies with mutant α-synuclein (A53T) display neurodegenerative changes that include movement dysfunctions and a loss of dopaminergic neurons in the brain. In the present study, we measured reactive oxygen species (ROS) levels in α-synuclein transgenic flies by monitoring the fluorescence levels of redox-sensitive indicators based on GFP (roGFP) in flies co-expressing roGFP and mutant α-synuclein. We found that the ROS levels were significantly increased in the mutant α-synuclein flies. The elevations in ROS levels were also proportionate to the behavioral disorders and the losses of dopaminergic neurons. We also found that CDDO-Me inhibited the increases in ROS levels in the A53T flies and improved the neurodegenerative changes by activating the Nrf2/antioxidant response element signaling pathway. Selective expression of the Nrf2 homologous gene cncC in the dopaminergic neurons effectively protected against the neurodegenerative phenotype of the A53T α-synuclein flies, compared to the flies that expressed cncC in all neurons. These results indicate that the reductions in oxidative stress that are mediated by the activation of the antioxidant signaling pathway can effectively attenuate the neurotoxicity caused by mutations in α-synuclein.

S100 calcium binding proteins have long been known to express in the adult nervous system, but their distribution in the developing brain, especially the human fetal brain, is largely unknown. We used an immunohistochemical method to determine the expression of three S100 proteins, namely S100A4, S100A5, and S100A13, in the human fetal hippocampus and temporal cortex from 12 to 33 weeks of gestation. At 12 weeks, S100A5 was strongly expressed in the cells and fibers of the polymorphic, pyramidal, and molecular layers of the hippocampus. Thereafter, its expression decreased with age. In the temporal cortex, S100A5 expression was detected from 12 weeks onwards, peaked at 20 to 24 weeks, and then decreased with age. The horizontal fibers of the marginal zone were immunoreactive at all stages examined. S100A13 immunoreactivity was also detected in both cells and fibers of the hippocampus at 12 weeks, became slightly stronger at 20 weeks, and then decreased with age. In the temporal cortex, S100A13 immunoreactivity was also strong in all cellular layers at 12 to 24 weeks before it declined with age from 28 weeks onwards. Among the three proteins examined, S100A4 showed the weakest expression, which was detected in the cells and fibers of the hippocampus and the temporal cortex at all stages examined. Our results have demonstrated for the first time, in the human fetal hippocampus and temporal cortex, specific spatio-temporal patterns of expression of these proteins, all of which are likely to have different roles to play during development despite their pronounced sequence homology.

The important role of neuroinflammation in many chronic and acute pathological conditions of the central nervous system is widely recognized. Curcumin is a major component of turmeric and reportedly has anti-inflammatory and anti-oxidant effects. This study investigated the inhibitory effect of curcumin on lipopolysacharide (LPS)-induced chemokine CCL2 (or monocyte chemoattractant protein-1, MCP-1) production and whether the effect is mediated by mitogen-activated protein kinases (MAPKs) in the rat astrocytoma cell C6. We observed that LPS (1 μg/ml) induced the upregulation of CCL2 mRNA and protein in C6. Treatment with curcumin (2.5, 10, and 25 μM) decreased the expression of CCL2 mRNA and protein in a dose-dependent manner under treatment with LPS. Additionally, the c-jun N-terminal kinase (JNK) inhibitor (SP600125) dose-dependently inhibited LPS-induced CCL2 upregulation, whereas the MAPK kinase (MEK) inhibitor (PD98059) only had a mild effect and the p38 MAPK inhibitor (SB203580) had no effect. Finally, western blot showed that LPS induced rapid JNK activation and curcumin reduced LPS-induced phosphoJNK (pJNK) expression at 30 min after LPS stimulation. These data suggest that the anti-neuroinflammatory effect of curcumin relates to the downregulation of CCL2 expression through the JNK pathway in astrocytoma cells, which indicates a possible benefit from the use of curcumin in the treatment of neuroinflammation-associated disorders.

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