286 research outputs found
Iron Insufficiency Compromises Motor Neurons and Their Mitochondrial Function in Irp2-Null Mice
Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2), which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 and ferritin, may have a causal role in disease. We demonstrated that two therapeutic approaches were beneficial for motor neuron survival. First, we activated a homologous protein, IRP1, by oral Tempol treatment and found that axons were partially spared from degeneration. Secondly, we genetically decreased expression of the iron storage protein, ferritin, to diminish functional iron starvation. These data suggest that functional iron deficiency may constitute a previously unrecognized molecular basis for degeneration of motor neurons in mice
Bundling up carbon nanotubes through Wigner defects
We show, using ab initio total energy density functional theory, that the
so-called Wigner defects, an interstitial carbon atom right besides a vacancy,
which are present in irradiated graphite can also exist in bundles of carbon
nanotubes. Due to the geometrical structure of a nanotube, however, this defect
has a rather low formation energy, lower than the vacancy itself, suggesting
that it may be one of the most important defects that are created after
electron or ion irradiation. Moreover, they form a strong link between the
nanotubes in bundles, increasing their shear modulus by a sizeable amount,
clearly indicating its importance for the mechanical properties of nanotube
bundles.Comment: 5 pages and 4 figure
Path Dependence in the Law: The Course and Pattern of Legal Change in a Common Law System
Can the Income Tax Be Saved?: The Promise and Pitfalls of Unitary Formulary Apportionment
NÃveis de energia lÃquida e ractopamina para leitoas em terminação sob conforto térmico
Titan's diverse landscapes as evidenced by Cassini RADAR's third and fourth looks at Titan
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