METHODS: Brain tumor tissues and corresponding blood specimens were obtained from 45 patients. The ND3 10398A>G alteration at target codon 114 was detected using the PCR-RFLP analysis and later was confirmed by DNA sequencing.
RESULTS: Twenty-six (57.8%) patients showed ND3 10398A>G mutation in their tumor specimens, in which 26.9% of these mutations were heterozygous mutations. ND3 10398A>G mutation was not significantly correlated with age, gender, and histological tumor grade, however was found more frequently in intra-axial than in extra-axial tumors (62.5% vs. 46.2%, p<0.01).
CONCLUSION: For the first time, we have been able to describe the occurrence of ND3 10398A>G mutations in a Malaysian brain tumor population. It can be concluded that mitochondrial ND3 10398A>G alteration is frequently present in brain tumors among Malaysian population and it shows an impact on the intra-axial tumors.
Methods: Human neuroblastoma cells SH-SY5Y (as a neuronal model) and human glioblastoma cells T98G (as an astrocytic model), were treated with 100-500 µM PA, oleic acid (OA) or lauric acid (LA) for 24 h or 48 h, and their cell viability was assessed by 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of stable overexpression of γ-synuclein (γ-syn), a neuronal protein recently recognized as a novel regulator of lipid handling in adipocytes, and transient overexpression of Parkinson's disease (PD) α-synuclein [α-syn; wild-type (wt) and its pathogenic mutants A53T, A30P and E46K] in SH-SY5Y and T98G cells, were also evaluated. The effects of co-treatment of PA with paraquat (PQ), a Parkinsonian pesticide, and leptin, a hormone involved in the brain-adipose axis, were also assessed. Cell death mode and cell cycle were analyzed by Annexin V/PI flow cytometry. Reactive oxygen species (ROS) level was determined using 2',7'-dichlorofluorescien diacetate (DCFH-DA) assay and lipid peroxidation level was determined using thiobarbituric acid reactive substances (TBARS) assay.
Results: MTT assay revealed dose- and time-dependent PA cytotoxicity on SH-SY5Y and T98G cells, but not OA and LA. The cytotoxicity was significantly lower in SH-SY5Y-γ-syn cells, while transient overexpression of wt α-syn or its PD mutants (A30P and E46K, but not A53T) modestly (but still significantly) rescued the cytotoxicity of PA in SH-SY5Y and T98G cells. Co-treatment of increasing concentrations of PQ exacerbated PA's neurotoxicity. Pre-treatment of leptin, an anti-apoptotic adipokine, did not successfully rescue SH-SY5Y cells from PA-induced cytotoxicity-suggesting a mechanism of PA-induced leptin resistance. Annexin V/PI flow cytometry analysis revealed PA-induced increase in percentages of cells in annexin V-positive/PI-negative quadrant (early apoptosis) and subG0-G1 fraction, accompanied by a decrease in G2-M phase cells. The PA-induced ROS production and lipid peroxidation was at greater extent in T98G as compared to that in SH-SY5Y.
Discussion: In conclusion, PA induces apoptosis by increasing oxidative stress in neurons and astrocytes. Taken together, the results suggest that HFD may cause neuronal and astrocytic damage, which indirectly proposes that CNS pathologies involving neuroinflammation and reactive gliosis could be prevented via the diet regimen.
METHODS: Eight cyclists exercised at three submaximal intensities before completing a TTE100% at sea-level (SEA) and at 1657 m of altitude (ALT), with pre-exercise consumption of 1000 mg of POMx or a placebo (PLAC) in a randomized, double-blind, crossover design. Data were analysed using a three way (treatment x altitude x intensity) or two-way (treatment x altitude) repeated measures ANOVA with a Fisher's LSD post-hoc analysis. Significance was set at p ≤ 0.05. The effect size of significant interactions was calculated using Cohen's d.
RESULTS: TTE100% performance was reduced in ALT but was not influenced by POMx (p > 0.05). Plasma NO3- were 10.3 μmol greater with POMx vs. PLAC (95% CI, 0.8, 19.7,F1,7 = 7.83, p 0.05). Submaximal VO2 values were not affected by POMx (p ≥ 0.05).
CONCLUSIONS: The restoration of SEA VO2 values at ALT is likely driven by the high polyphenol content of POMx, which is proposed to improve nitric oxide bioavailability. Despite an increase in VO2, no change in exercise performance occurred and therefore this study does not support the use of POMx as an ergogenic supplement.