Immunoreactivity of valosin-containing protein in sporadic amyotrophic lateral sclerosis and in a case of its novel mutant.

BACKGROUND: Mutations in the valosin-containing protein (VCP) gene were first found to cause inclusion- body myopathy with early-onset Paget disease and frontotemporal dementia (IBMPFD). Mutations in the VCP gene were later reported to occur in familial amyotrophic lateral sclerosis (ALS). But the role of VCP in the neurodegenerative processes that occur in ALS remains unknown. The purpose of the present study was to elucidate the role of VCP in the neurodegeneration seen in sporadic and VCP mutant ALS. RESULTS: Immunohistochemistry demonstrated that the frequency of distinct VCP-positive nuclei of spinal motor neurons of patients with sporadic ALS (SALS) and the ALS with VCP novel mutation (ALS-VCP, M158V) was increased, compared with that of the control cases. No VCP-positive inclusion bodies were observed in SALS patients, a ALS-VCP patient or in control subjects. Neuropathologic examination of the ALS-VCP case showed loss of motor neurons, the presence of Bunina bodies, and degeneration of the corticospinal tracts. Bunina bodies detected in this case were confirmed to show immunohistochemical and ultrastructural features similar to those previously described. Furthermore, neuronal intracytoplasmic inclusions immunopositive for TAR DNA-binding protein 43 kDa (TDP-43), phosphorylated TDP-43, ubiquitin (Ub), p62, and optineurin were identified in the spinal and medullary motoneurons, but not in the neocortex. Gene analysis of this ALS-VCP patient confirmed the de novo mutation of M158V, which was not found in control cases; and bioinformatics using several in silico analyses showed possible damage to the structure of VCP. Immunocytochemical study of cultured cells showed increased cytoplasmic translocation of TDP-43 in cells transfected with several mutant VCP including our patient's compared with wild-type VCP. CONCLUSION: These findings support the idea that VCP is associated with the pathomechanism of SALS and familial ALS with a VCP mutation, presumably acting through a dominant-negative mechanism.

Nano-micrometer-architectural acidic silica prepared from iron oxide of Leptothrix ochracea origin.

We prepared nano-micrometer-architectural acidic silica from a natural amorphous iron oxide with structural silicon which is a product of the iron-oxidizing bacterium Leptothrix ochracea. The starting material was heat-treated at 500 °C in a H2 gas flow leading to segregation of α-Fe crystalline particles and then dissolved in 1 M hydrochloric acid to remove the α-Fe particles, giving a gray-colored precipitate. It was determined to be amorphous silica containing some amount of iron (Si/Fe = ~60). The amorphous silica maintains the nano-microstructure of the starting material-~1-µm-diameter micrometer-tubules consisting of inner globular and outer fibrillar structures several tens of nanometer in size-and has many large pores which are most probably formed as a result of segregation of the α-Fe particles on the micrometer-tubule wall. The smallest particle size of the amorphous silica is ~10 nm, and it has a large surface area of 550 m(2)/g with micropores (0.7 nm). By using pyridine vapor as a probe molecule to evaluate the active sites in the amorphous silica, we found that it has relatively strong Brønsted and Lewis acidic centers that do not desorb pyridine, even upon evacuation at 400 °C. The acidity of this new silica material was confirmed through representative two catalytic reactions: ring-opening reaction and Friedel-Crafts-type reaction, both of which are known to require acid catalysts.

Impact of obesity on IgA nephropathy: comparative ultrastructural study between obese and non-obese patients.

BACKGROUND: The pathological role of obesity in the progression of glomerular lesions has rarely been studied in primary glomerular diseases. The purpose of this study is to investigate the influence of non-diabetic obesity on clinicopathological findings in IgA nephropathy. METHODS: 74 patients with biopsy-proven IgA nephropathy were retrospectively divided into two groups according to the criteria for obesity in Japan: non-obese group (group N: n = 50) with BMI <25 kg/m(2), and obese group (group O: n = 24) with BMI > or =25 kg/m(2). Clinical and pathological data at the time of renal biopsy were analyzed. Moreover, the outcome of proteinuria in patients treated with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin II receptor blockers (ARB) was evaluated in different groups after a 1-year follow-up. RESULTS: Urinary protein excretion was significantly greater in the obese group compared to normal-weight patients (p < 0.05). There was no significant difference in the prevalence of hypertension and hyperlipidemia. By light microscopy, the obese group showed significantly larger glomerular size (p < 0.0001). On the other hand, the severity of mesangial matrix expansion and crescent formation revealed no difference between the two groups. By electron microscopy, glomerular basement membrane (GBM) thickness was significantly increased in obese patients (p < 0.001). Among 61 patients who were followed up for 1 year in our institute, 15 patients were treated with ACE-I or ARB without steroids. ACE-I or ARB treatment without steroids tended to reduce proteinuria in the obese patients, but this change did not achieve statistical significance. CONCLUSIONS: In IgA nephropathy, obesity induces not only glomerular enlargement but also ultrastructural modification of GBM, which would contribute to increase proteinuria.