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  • Expression of recombinant NMDA receptors in hippocampal neurons by adenoviral-mediated gene transfer. 10320794

    N-methyl-d-aspartate (NMDA) receptors have attracted a great deal of attention because they are intimately involved in brain development, synaptic plasticity and a variety of neurological disorders. The ability to artificially alter the properties of NMDA receptors in central nervous system (CNS) neurons would be useful for elucidating the physiological roles of these receptors. It would also raise the possibility of gene therapy of neurological diseases caused by malfunction of NMDA receptors. In this study, we constructed three recombinant adenoviruses encoding rat NMDA receptor subunit cDNAs, NMDAR1 (NR1), NMDAR2B (NR2B) and mutant NR1(N598R) in which the asparagine (N) site of the wild-type NR1 was replaced with arginine (R) by site-directed mutagenesis. PC12 cells co-infected with recombinant adenoviruses bearing NR1 and NR2B cDNAs expressed conventional NMDA receptors that were permeable to Ca2+ and sensitive to Mg2+, whereas those with viruses bearing NR1(N598R) and NR2B cDNAs expressed Ca2+-impermeable and Mg2+-insensitive receptors. When rat hippocampal neurons in culture were infected with NR1(N598R) and NR2B viruses, both Ca2+ permeability and Mg2+ sensitivity of NMDA receptors were markedly reduced in the infected neurons. Excitatory postsynaptic currents (EPSCs) mediated by NMDA receptors also became much less sensitive to Mg2+. Thus, the NR1(N598R)/NR2B receptors were more dominant than the native NMDA receptors in the infected neurons, and the former receptors introduced by the adenoviral vectors functioned as postsynaptic receptors. These results indicate that the functional properties of postsynaptic NMDA receptors can be manipulated by gene transfer technology using adenoviral vectors.
    Document Type:
    Reference
    Product Catalog Number:
    AB1557P
    Product Catalog Name:
    Anti-NMDAR2B Antibody

  • Sites of allergic airway smooth muscle remodeling and hyperresponsiveness are not associated in the rat. 20651225

    The cause-and-effect relationship between airway smooth muscle (ASM) remodeling and airway hyperresponsiveness (AHR) following allergen challenge is not well established. Using a rat model of allergen-induced ASM remodeling we explored the relationship between the site of ASM remodeling and AHR. Brown Norway rats, sensitized and challenged (3 times at 5-day intervals) with ovalbumin, were intranasally administered 0.1 mg/kg budesonide 24 and 1 h before challenge. Airway responses to aerosolized methacholine were assessed 48 h or 1 wk after three challenges. Airways were stained and analyzed for total airway wall area, area of smooth muscle-specific α-actin, and goblet cell hyperplasia, and the constant-phase model was used to resolve the changes in respiratory system mechanics into large airway and peripheral lung responses. After three ovalbumin challenges, there was a significant increase in ASM area and in the total wall area in all sized airways as well as an increase in goblet cells in the central airways. Budesonide inhibited ASM growth and central airway goblet cell hyperplasia following ovalbumin challenges. Budesonide also inhibited small but not large airway total wall area. AHR was attributable to excessive responses of the small airways, whereas responsiveness of the large airways was unchanged. Budesonide did not inhibit AHR after repeated challenge. We conclude that ASM remodeling induced by repeated allergen challenges involves the entire bronchial tree, whereas AHR reflects alterations in the lung periphery. Prevention of ASM remodeling by corticosteroid does not abrogate AHR.
    Document Type:
    Reference
    Product Catalog Number:
    07-677

  • Constant illumination causes spatially discrete dopamine depletion in the normal and degenerate retina. 17223011

    A fully competent retinal dopamine system underpins normal visual function. Although this system is known to be compromised both prior to and during retinal degeneration, the spatial dynamics of dopamine turnover within the degenerate retina are at present unknown. Here, using immunohistochemistry for dopamine in combination with quantitative optical density measurements, we reveal a global decline in retinal dopamine levels in the light adapted RCS dystrophic rat, which is restricted to plexiform layers in the dark. Pharmacological blockade of dopamine production with the drug alpha-methyl-p-tyrosine (AMPT) allows the direct visualisation of dopamine depletion in normal and degenerate retina in response to constant illumination. In normal retinae this effect is spatially discrete, being undetectable in perikarya and specific to amacrine cell fibres in sublamina 1 of the inner plexiform layer. A similar response was observed in the retinae of dystrophic rats but with a reduction in amplitude of approximately 50%. It is suggested that the pattern of dopamine depletion observed in rat retina may reflect an AMPT-resistant pool of perikaryal dopamine and/or a reduction in extrasynaptic release of this neurotransmitter in response to illumination in vivo. We conclude that the visualisation of dopamine depletion reported here represents a release of this neurotransmitter in the response to light. Turnover of dopamine in the dystrophic retina is discussed in the context of surviving photoreceptors, including the intrinsically photosensitive melanopsin ganglion cells of the inner retina.
    Document Type:
    Reference
    Product Catalog Number:
    AB122S
    Product Catalog Name:

  • Constant p53 pathway inactivation in a large series of soft tissue sarcomas with complex genetics. 20884963

    Alterations of the p53 pathway are among the most frequent aberrations observed in human cancers. We have performed an exhaustive analysis of TP53, p14, p15, and p16 status in a large series of 143 soft tissue sarcomas, rare tumors accounting for around 1% of all adult cancers, with complex genetics. For this purpose, we performed genomic studies, combining sequencing, copy number assessment, and expression analyses. TP53 mutations and deletions are more frequent in leiomyosarcomas than in undifferentiated pleomorphic sarcomas. Moreover, 50% of leiomyosarcomas present TP53 biallelic inactivation, whereas most undifferentiated pleomorphic sarcomas retain one wild-type TP53 allele (87.2%). The spectrum of mutations between these two groups of sarcomas is different, particularly with a higher rate of complex mutations in undifferentiated pleomorphic sarcomas. Most tumors without TP53 alteration exhibit a deletion of p14 and/or lack of mRNA expression, suggesting that p14 loss could be an alternative genotype for direct TP53 inactivation. Nevertheless, the fact that even in tumors altered for TP53, we could not detect p14 protein suggests that other p14 functions, independent of p53, could be implicated in sarcoma oncogenesis. In addition, both p15 and p16 are frequently codeleted or transcriptionally co-inhibited with p14, essentially in tumors with two wild-type TP53 alleles. Conversely, in TP53-altered tumors, p15 and p16 are well expressed, a feature not incompatible with an oncogenic process.
    Document Type:
    Reference
    Product Catalog Number:
    S7821
    Product Catalog Name:
    CpGenome Universal Methylated DNA

  • Evolution of the eye transcriptome under constant darkness in Sinocyclocheilus cavefish. 23612715

    In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and evolve alternatives for exploring their environments. Although troglodyte features evolved independently many times in cavefish, we do not yet know whether independent evolution of these characters involves common genetic mechanisms. Surface-dwelling and many cave-dwelling species make the freshwater teleost genus Sinocyclocheilus an excellent model for studying the evolution of adaptations to life in constant darkness. We compared the mature retinal histology of surface and cave species in Sinocyclocheilus and found that adult cavefish showed a reduction in the number and length of photoreceptor cells. To identify genes and genetic pathways that evolved in constant darkness, we used RNA-seq to compare eyes of surface and cave species. De novo transcriptome assemblies were developed for both species, and contigs were annotated with gene ontology. Results from cave-dwelling Sinocyclocheilus revealed reduced transcription of phototransduction and other genes important for retinal function. In contrast to the blind Mexican tetra cavefish Astyanax mexicanus, our results on morphologies and gene expression suggest that evolved retinal reduction in cave-dwelling Sinocyclocheilus occurs in a lens-independent fashion by the reduced proliferation and downregulation of transcriptional factors shown to have direct roles in retinal development and maintenance, including cone-rod homeobox (crx) and Wnt pathway members. These results show that the independent evolution of retinal degeneration in cavefish can occur by different developmental genetic mechanisms.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Long-term, progressive, aerobic training increases adiponectin in middle-aged, overweight, untrained males and females. 21271804

    Abstract Adipose tissue secretes the adipokine, adiponectin (ADPN), which increases insulin sensitivity. Because some of the metabolic effects of exercise and ADPN are similar, exercise has been proposed to increase ADPN. However, most short-term (≤3 mos) and constant-effort exercise protocols have not produced increases in ADPN. Furthermore, no direct comparisons of male and female subjects on the effect of exercise on ADPN levels have been reported. We hypothesized that long-term (6 mos), progressive training would increase ADPN levels in both males and females. We recruited middle-aged, untrained males and females to participate in an interventional study employing a marathon training regimen progressing from 9.7 to 88.5 km (6 to 55 miles) per week over 6 mos. At baseline, we matched the mean ages of the male and female groups. We collected and stored fasting plasma samples and recorded body measurements at 0 (baseline) and 6 mos. Stored samples were analysed for insulin, glucose, and ADPN. ADPN increased significantly among both males (from 5.89 ± 2.46 (mean ± SD) to 7.65 ± 3.18 μg/ml; p < 0.05) and females (from 8.48 ± 3.22 to 10.56 ± 4.05 μg/ml; p < 0.05). The extent of the increase in ADPN was similar in the male (40.7 ± 50%; median, 12.1%) and female (27.0 ± 31.1%; median, 22.3%) groups. However, there was no significant reduction in insulin resistance as measured by the HOMA-IR scores in either group. We conclude that long-term, progressive aerobic training increases circulating ADPN levels in middle-aged, untrained males and females.
    Document Type:
    Reference
    Product Catalog Number:
    EZHI-14K
    Product Catalog Name:
    Human Insulin ELISA