(C) 2011 American Institute of Physics. [doi:10.1063/1.3531565]“
“Here we present the ascidian Ciona intestinalis
as an alternative invertebrate system to study Alzheimer’s disease (AD) pathogenesis. Through the use of AD animal models, researchers often attempt to reproduce various aspects of the disease, particularly the coordinated processing of the amyloid precursor CP358774 protein (APP) by alpha-, beta- and gamma-secretases to generate amyloid beta (A beta)-containing plaques. Recently, Drosophila and C. elegans AD models have been developed, exploiting the relative simplicity of these invertebrate systems, but they lack a functional A beta sequence and a beta-secretase ortholog, thus complicating efforts to examine APP processing in vivo. We propose that the ascidian is a more appropriate invertebrate AD model owing to their phylogenetic relationship with humans. This is supported by bioinformatic analyses, which indicate that the ascidian genome contains orthologs of all AD-relevant click here genes. We report that transgenic ascidian larvae can
properly process human APP(695) to generate A beta peptides. Furthermore, A beta can rapidly aggregate to form amyloid-like plaques, and plaque deposition is significantly increased in larvae expressing a human APP(695) variant associated with familial Alzheimer’s disease. We also demonstrate that nervous system-specific A beta expression alters normal larval behavior during attachment. Importantly, plaque formation and alterations in behavior are not only observed within 24 hours post-fertilization, but anti-amyloid drug treatment improves these AD-like pathologies. This ascidian model for AD provides a powerful and rapid system to study APP processing, A beta plaque formation and behavioral alterations, and could aid in identifying factors that modulate amyloid deposition and the associated disruption of normal cellular function and behaviors.”
“The grafted copolymer (SBS-g-MBP) with different grafting ratio, synthesized by our laboratory,
was irradiated by ultraviolet (UV) radiation with different time. The structure of SBS-g-MBP before and after UV exposure was characterized by Fourier transform infrared spectrometer, and the results confirmed that the UV-cross-linked structure was formed. The gel fraction before and after UV exposure was discussed, SGC-CBP30 and the results indicated that the gel fraction increased with both exposure time and grafting ratio, and it also indicated the gel fraction was affected mainly by the exposure time. Further-more, the results of scanning electron microscopy showed that the mode of fracture surfaces transmitted gradually from tough fracture to brittle fracture. The differential scanning calorimetry and thermal gravimetric analyzer indicated that the crosslinking has taken place in the polybutadiene block, and the thermal property was improved after UV exposure.