Valproic acid (VPA) has long been used as an antiepileptic drug and recently as a mood stabilizer, and evidence is increasing that VPA exerts neuroprotective effects through changes in a variety of intracellular signalling pathways including upregulation of Bcl-2 protein with an antiapoptotic property and inhibiting glycogen synthase kinase 3-beta, which is considered to promote cell survival. Although the neuroprotective effects of VPA have been demonstrated in a murine model of human immunodeficiency virus-1 encephalitis, there have been no reports on the effect of VPA in chronic progressing neurodegenerative disease models including amyotrophic lateral sclerosis (ALS). ALS is a devastating disease selectively affecting motoneurons, and its disease model mice bear a close resemblance to ALS symptomatically and pathologically. First, we used an organotypic slice culture using mouse spinal cord, and showed that VPA protected spinal motoneurons against death from glutamate toxicity in vitro. Then, we treated ALS model mice with VPA at the dose effective level for epileptic model mice after 45 days of age (pre-onset treatment) or the day of the disease onset (post-onset treatment). We found a significant prolongation of the disease duration in ALS model mice in both methods of treatment. Considering the long usage of VPA for epileptic patients with good tolerance and safety, these data strongly support the clinical application of VPA for ALS treatment.

During embryonic development, approximately one-half of the spinal motoneurons initially generated are lost during a wave of programmed cell death (PCD). Classical studies in this system laid the basis of much work on the role and control of neuronal cell death during development. However, we have little information concerning the timing of cell death in motoneuron pools at different rostrocaudal levels, especially in rodents. We developed a novel protocol for whole-mount TUNEL labeling that allows apoptotic nuclei to be visualized in whole-mount preparations of embryonic spinal cord; double labeling with antibodies to Islet 1/2 showed that nearly all TUNEL-positive cells were motoneurons. In chicken and mouse embryos, the density of TUNEL-positive nuclei was specifically increased following target ablation. The pattern of naturally occurring motoneuron PCD was studied in spinal cords from different species and ages: chick (E4.5-E9.0), mouse (E11.5-E15.5), and rat (E13.5-E16. 5). In all species, motoneuron PCD is first apparent at cervical levels and last at sacral levels. However, motoneuron PCD does not follow a strict rostrocaudal sequence. Following cervical motoneuron PCD, TUNEL profiles are first observed at lumbar levels in chick but at thoracic levels in rat. At a given rostrocaudal level, medial motoneurons tend to die before lateral populations, but here too there are exceptions. Motoneuron cell death is thus regulated in a highly stereotyped manner during development of vertebrate spinal cord. Our technique will provide a basis for the monitoring even localized changes in this pattern.

Hepatoma-derived growth factor (HDGF) is a heparinbinding proliferating factor originally isolated from conditioned medium of the hepatoma-derived cell line HuH-7. HDGF has greatest homology in an amino acid sequence with high mobility group 1 (HMG1), which has been characterized as a DNA-binding, inflammatory, and potent neurite outgrowth molecule. HDGF is reported to be widely expressed and act as a growth factor in many kinds of cells. However, it has not been investigated in the nervous system. Here, we show by Western blot analysis that HDGF is present in the mouse brain from the embryonic period until adulthood. In situ hybridization and immunohistochemical analyses revealed that HDGF was expressed mainly in neurons, and HDGF protein was localized to the nucleus. HDGF and high mobility group 1 were secreted under physiological conditions and released extracellularly in necrotic conditions. Furthermore, we showed that exogenously supplied HDGF had a neurotrophic effect and was able to partially prevent the cell death of neurons in which endogenous HDGF was suppressed. Therefore, we propose that HDGF is a novel type of neurotrophic factor, on account of its localization in the nucleus and its potential to function in an autocrine manner under both physiological and pathological conditions throughout life.

Activation of the Fas death receptor leads to the death of motoneurons in culture. To investigate the role of Fas in programmed cell death and pathological situations, we used several mutant mice deficient for Fas signaling and made a novel transgenic FADD-DN (FAS-associated death domain-dominant-negative) strain. In vitro, motoneurons from all of these mice were found to be resistant to Fas activation and to show a delay in trophic deprivation-induced death. During normal development in vivo, no changes in motoneuron survival were observed. However, the number of surviving motoneurons was twofold higher in animals deficient for Fas signaling after facial nerve transection in neonatal mice. These results reveal a novel role for Fas as a trigger of axotomy-induced death and suggest that the Fas pathway may be activated in pathological degeneration of motoneurons.

Studies on the clinical course of familial ALS suggest that the duration of illness is relatively consistent for each mutation but variable among the different mutations. The authors analyzed the relative amount of mutant compared with normal SOD1 protein in the erythrocytes from 29 patients with ALS with 22 different mutations. Turnover of mutant SOD1 correlated with a shorter disease survival time.

8-OHdG is a risk factor for the development of HCC in patients with chronic HCV infection. Patients with chronic HCV who express 8-OHdG should be monitored carefully for the development of HCC.

We previously reported that myelin-associated oligodendrocytic basic protein (MOBP) was abundantly expressed in the central nervous system (CNS) myelin, and shared several characteristics with myelin basic protein (MBP). In particular, a cluster of positively charged amino acids was considered to facilitate compaction of the cytoplasmic face of the myelin sheath, as in the case of MBP. However, the contribution of MOBP in forming and maintaining the myelin sheath still remains unclear. Recent investigations showed that one isoform of MOBP was expressed in the embryo prior to myelination, and MOBP isoforms were colocalized with the microtubular network and nucleus in vitro. To explore the role of MOBP in vivo, we generated MOBP-deficient mice and analysed the CNS myelin. Surprisingly, the compact myelin was formed, however, the myelin from MOBP-deficient mice exposed to hexachlorophene, a known dysmyelinating agent, showed widening of the major dense lines. These results suggest that MOBP is not essential for myelin formation, but reinforces the apposition of the cytoplasmic faces of the myelin sheath. A striking phenotype of MOBP-deficient mice was the presence of the straight 'condensed' radial component. This component has been described as a tight junction-like complex running radially and zig-zag through the CNS myelin sheath between inner and outer mesaxons. These results suggest that MOBP is essential for normal arrangement of the radial component.

The charge-carrier dynamics of anatase TiO2 nanoparticles in an aqueous solution were studied by femtosecond time-resolved X-ray absorption spectroscopy using an X-ray free electron laser in combination with a synchronized ultraviolet femtosecond laser (268 nm). Using an arrival time monitor for the X-ray pulses, we obtained a temporal resolution of 170 fs. The transient X-ray absorption spectra revealed an ultrafast Ti K-edge shift and a subsequent growth of a pre-edge structure. The edge shift occurred in ca. 100 fs and is ascribed to reduction of Ti by localization of generated conduction band electrons into shallow traps of self-trapped polarons or deep traps at penta-coordinate Ti sites. Growth of the pre-edge feature and reduction of the above-edge peak intensity occur with similar time constants of 300–400 fs, which we assign to the structural distortion dynamics near the surface.