Kainic acid induces expression of caveolin-1 in activated microglia in rat brain

Caveolin-1, a major constituent of caveolae, has been implicated in endocytosis, signal transduction and cholesterol transport in a wide variety of cells. In the present study, the expression of caveolin-1 was examined by immunohistochemistry in rat brain with or without systemic injection of kainic acid (KA). Caveolin-1 immunoreactivity was observed in capillary walls in brains of control rats. From one to seven days after KA injection, caveolin-1 immunoreactivity appeared in activated microglia in the cerebral cortex, hippocampus and other brain regions. The strongest immunoreactivity of microglia was seen after 3 days after KA administration. The expression of caveolin-1 was confirmed by RT-PCR and Western blot analysis, respectively. The induction of caveolin-1 expression in microglia activated in response to kainic acid administration suggests its possible role in a modulation of inflammation. (Folia Histochemica et Cytobiologica 2013, Vol. 51, No. 1, 25–30

Immunohistochemical Mapping of TRK-Fused Gene Products in the Rat Brainstem

The TRK-fused gene (TFG in human, Tfg in rat) was originally identified in human papillary thyroid cancer as a chimeric form of the NTRK1 gene. It was since reported that the gene product (TFG) plays a role in regulating phosphotyrosine-specific phosphatase-1 activity. As shown in the accompanying paper, we produced an antibody to rat TFG and used it to localize TFG to selected neurons in specific regions. In the present study, we mapped the TFG-positive neurons in the brainstem, cerebellum, and spinal cord of rats. In the brainstem, neurons intensely positive for TFG were distributed in the raphe nuclei, the gigantocellular reticular nucleus, the reticulotegmental nucleus of the pons, and some cranial nerve nuclei such as the trigeminal nuclei, the vestibulocochlear nuclei, and the dorsal motor nucleus of the vagus. Purkinje cells in the cerebellum and motor neurons in the spinal anterior horn were also positive for TFG. These results provide fundamental data for studying the functions of TFG in the brain

Depth of interaction measured with LYSO (Ce) scintillator in a new method

　The importance of the information concerning the depth of interaction (DOI) in a PET device has been stressed by many authors. In this paper, the attenuation of the emitted light in a thin LYSO (Ce) scintillator crystal has been measured for the purpose of obtaining information about DOI from the ratio of the light output measured at both ends of the crystal. A pair of photomultipliers were attached to the two ends of the crystal for this purpose. An array of wave-length shifters(WLS) attached to the crystal from a side was used in order to find the hit point of the incident gamma rays along the crystal. The attenuation constant μ determined in this measurement is μ＝0.79 ± 0.0007/cm. This value is experimentally demonstrated to be appropriate for the DOI estimation using the ratio of the amounts of light. The obtainable DOI resolution, when the crystal is read out using WLS and a new kind of position-sensitive photomultipliers in our next prototype, is estimated

Expression and Localization of TRK-Fused Gene Products in the Rat Brain and Retina

The TRK-fused gene (TFG in human, Tfg in rat) was originally identified in human papillary thyroid cancer as a chimeric form of the NTRK1 gene. It has been reported that the gene product (TFG) plays a role in regulating phosphotyrosine-specific phosphatase-1 activity. However, no information regarding the localization of Tfg in rat tissues is available. In this study, we investigated the expression of Tfg mRNA in normal rat tissues using reverse transcription-polymerase chain reaction (RT-PCR). We also produced an antibody against Tfg gene products and examined the localization of TFG in the rat brain and retina. The RT-PCR experiments demonstrated that two types of Tfg mRNA were expressed in rat tissues: the conventional form of Tfg (cTfg) and a novel variant form, retinal Tfg (rTfg). RT-PCR analyses demonstrated that cTfg was ubiquitously expressed in rat tissues, while rTfg was predominantly expressed in the brain and retina. Western blot analysis demonstrated two bands with molecular weights of about 30 kDa and 50 kDa in the rat brain. Immunohistochemistry indicated that TFG proteins were predominantly expressed by neurons in the brain. In the rat retina, intense TFG-immunoreactivity was detected in the layer of rods and cones and the outer plexiform layer

Differences in Gene Expression Profiles and Phenotypes of Differentiated SH-SY5Y Neurons Stably Overexpressing Mitochondrial Ferritin

Mitochondrial ferritin (FtMt) is an iron-transport protein with ferroxidase properties localized to mitochondria. Levels are generally low in all tissues, while increasing the expression of FtMt in neuronal-like cells has been shown to be protective. To determine whether FtMt has potential as a therapeutic approach, there remains the question of how much FtMt is protective. To address this issue, we transfected SH-SY5Y neuroblastoma cells with a FtMt expression plasmid and isolated cell lines with stable expression of FtMt at high, medium and low levels. Using these cell lines, we examined effects of FtMt on neuronal phenotype, neuroprotective activity and gene expression profiles. The phenotypic properties of high, medium and low FtMt expressors were compared with native untransfected SH-SY5Y cells after differentiation with retinoic acid to a neuronal phenotype. Overexpression of FtMt, even in low expressing cells, showed significant protection from oxidative stress induced by hydrogen peroxide or cobalt chloride. Higher levels of FtMt expression did not appear to offer greater protection, and did not have toxic consequences to cells, even though there were significantly more aggregated mitochondria in the highest expressing clone. The phenotypes differed between cell clones when assessed by cell growth, neurite outgrowth, and expression of neuronal proteins including those associated with neurodegenerative diseases. Microarray analysis of high, medium and negative FtMt-expressing cells identified different patterns of expression of certain genes associated with oxidative stress and neuronal development, amongst others. Validation of microarray analyses was carried out by real time polymerase chain reaction. The results showed significant differences in expression of thioredoxin-interacting protein (TXNIP) and microsomal glutathione transfer-1 (MGST-1), which can have critical roles in the regulation of oxidative stress. Differences in expression of calcitonin-related polypeptide alpha (CALCA), growth differentiation factor-15 (GDF-15) and secretogranin II (SCG2) were also observed. Our findings indicate that even low levels of increased FtMt expression can be protective possibly by alterations of some oxidative stress-related and growth factor genes, while high levels of expression did not appear to offer greater protection from oxidative stress or induce significant toxicity in cells. These experiments provide supporting data that increasing FtMt might be a feasible strategy for therapeutics in certain neurodegenerative and neurological diseases

Novel scheme for Lane-Bates\u27 blind deconvolution : Determinant conditions for the zeros of blurs and a simple algorithm for eliminating blurs

　The Lane-Bates method of blind deconvolution makes it possible to analytically recover the original image without prior knowledge of blurs convolved in a given image. The method utilizes the zeros of the z-transform of the given image. Its implementation, however, requires highly nontrivial analysis of the zeros. We have developed a novel scheme that considerably simplifies the analysis of the zeros. We have developed two versions of the scheme, i.e., determinant conditions (DCs) for the zeros of blurs and a search algorithm (SA) of blur images. The DCs consist of two forms, i.e., a derivative form and a multi-point form. The derivative form is given as a determinant form of conditions on derivatives of the zeros of assumed blurs that can be evaluated by using zeros of the z-transform of the given image. On the other hand, the multi-point form is given as a determinant form of conditions on the zeros of assumed blurs that are evaluated at multiple points in z space. The scheme is particularly powerful when the blurs have multiple structures as we illustrate. The SA is given as a form of simultaneous equations for blur elements of an assumed blur. The method is powerful when we try to find a single blur. This method is robust for compressed gray-scale images. These methods have been experimentally tested with model blurred images and shown to be powerful. In this report we illustrate how they are useful for the Lane-Bates blind deconvolution

Efficient Methods of Blind Deconvolution Based on the Lane-Bates Algorithm: Comprehensive Summary

　We developed efficient methods of blind deconvolution on the basis of the Lane-Bates algorithm. The methods consist of two kinds of mathematical tools and their modified versions. We give a comprehensive summary of them in this report

Study on the light insulator between scintillator crystals

　In our current project, we undertake an R&D of a new type of PED device which can be produced with a much lower cost yet has a better spatial resolution, compared to the currently used devices. In the course of this development, we encountered a difficulty of light cross-talk between the scintillator crystals. Large amount of effort has been paid to find out the best material to be used to reduce this cross-talk without reducing the light output and the spatial resolution. The experimental result shows that a black flock paper has the most promising features