The Firre locus produces a trans -acting RNA molecule that functions in hematopoiesis

Abstract: RNA has been classically known to play central roles in biology, including maintaining telomeres, protein synthesis, and in sex chromosome compensation. While thousands of long noncoding RNAs (lncRNAs) have been identified, attributing RNA-based roles to lncRNA loci requires assessing whether phenotype(s) could be due to DNA regulatory elements, transcription, or the lncRNA. Here, we use the conserved X chromosome lncRNA locus Firre, as a model to discriminate between DNA- and RNA-mediated effects in vivo. We demonstrate that (i) Firre mutant mice have cell-specific hematopoietic phenotypes, and (ii) upon exposure to lipopolysaccharide, mice overexpressing Firre exhibit increased levels of pro-inflammatory cytokines and impaired survival. (iii) Deletion of Firre does not result in changes in local gene expression, but rather in changes on autosomes that can be rescued by expression of transgenic Firre RNA. Together, our results provide genetic evidence that the Firre locus produces a trans-acting lncRNA that has physiological roles in hematopoiesis

Protective Effects of Positive Lysosomal Modulation in Alzheimer's Disease Transgenic Mouse Models

Alzheimer's disease (AD) is an age-related neurodegenerative pathology in which defects in proteolytic clearance of amyloid β peptide (Aβ) likely contribute to the progressive nature of the disorder. Lysosomal proteases of the cathepsin family exhibit up-regulation in response to accumulating proteins including Aβ1–42. Here, the lysosomal modulator Z-Phe-Ala-diazomethylketone (PADK) was used to test whether proteolytic activity can be enhanced to reduce the accumulation events in AD mouse models expressing different levels of Aβ pathology. Systemic PADK injections in APPSwInd and APPswe/PS1ΔE9 mice caused 3- to 8-fold increases in cathepsin B protein levels and 3- to 10-fold increases in the enzyme's activity in lysosomal fractions, while neprilysin and insulin-degrading enzyme remained unchanged. Biochemical analyses indicated the modulation predominantly targeted the active mature forms of cathepsin B and markedly changed Rab proteins but not LAMP1, suggesting the involvement of enhanced trafficking. The modulated lysosomal system led to reductions in both Aβ immunostaining as well as Aβx-42 sandwich ELISA measures in APPSwInd mice of 10–11 months. More extensive Aβ deposition in 20-22-month APPswe/PS1ΔE9 mice was also reduced by PADK. Selective ELISAs found that a corresponding production of the less pathogenic Aβ1–38 occurs as Aβ1–42 levels decrease in the mouse models, indicating that PADK treatment leads to Aβ truncation. Associated with Aβ clearance was the elimination of behavioral and synaptic protein deficits evident in the two transgenic models. These findings indicate that pharmacologically-controlled lysosomal modulation reduces Aβ1–42 accumulation, possibly through intracellular truncation that also influences extracellular deposition, and in turn offsets the defects in synaptic composition and cognitive functions. The selective modulation promotes clearance at different levels of Aβ pathology and provides proof-of-principle for small molecule therapeutic development for AD and possibly other protein accumulation disorders

Heterogeneity of mammary lesions represent molecular differences

BACKGROUND: Human breast cancer is a heterogeneous disease, histopathologically, molecularly and phenotypically. The molecular basis of this heterogeneity is not well understood. We have used a mouse model of DCIS that consists of unique lines of mammary intraepithelial neoplasia (MIN) outgrowths, the premalignant lesion in the mouse that progress to invasive carcinoma, to understand the molecular changes that are characteristic to certain phenotypes. Each MIN-O line has distinguishable morphologies, metastatic potentials and estrogen dependencies. METHODS: We utilized oligonucleotide expression arrays and high resolution array comparative genomic hybridization (aCGH) to investigate whole genome expression patterns and whole genome aberrations in both the MIN-O and tumor from four different MIN-O lines that each have different phenotypes. From the whole genome analysis at 35 kb resolution, we found that chromosome 1, 2, 10, and 11 were frequently associated with whole chromosome gains in the MIN-Os. In particular, two MIN-O lines had the majority of the chromosome gains. Although we did not find any whole chromosome loss, we identified 3 recurring chromosome losses (2F1-2, 3E4, 17E2) and two chromosome copy number gains on chromosome 11. These interstitial deletions and duplications were verified with a custom made array designed to interrogate the specific regions at approximately 550 bp resolution. RESULTS: We demonstrated that expression and genomic changes are present in the early premalignant lesions and that these molecular profiles can be correlated to phenotype (metastasis and estrogen responsiveness). We also identified expression changes associated with genomic instability. Progression to invasive carcinoma was associated with few additional changes in gene expression and genomic organization. Therefore, in the MIN-O mice, early premalignant lesions have the major molecular and genetic changes required and these changes have important phenotypic significance. In contrast, the changes that occur in the transition to invasive carcinoma are subtle, with few consistent changes and no association with phenotype. CONCLUSION: We propose that the early lesions carry the important genetic changes that reflect the major phenotypic information, while additional genetic changes that accumulate in the invasive carcinoma are less associated with the overall phenotype

Nanostructures Technology, Research, and Applications

Contains reports on twenty-four research projects and a list of publications.Joint Services Electronics Program Grant DAAHO4-95-1-0038Defense Advanced Research Projects Agency/Semiconductor Research Corporation SA1645-25508PGU.S. Army Research Office Grant DAAHO4-95-1-0564Defense Advanced Research Projects Agency/U.S. Navy - Naval Air Systems Command Contract N00019-95-K-0131Suss Advanced Lithography P. O. 51668National Aeronautics and Space Administration Contract NAS8-38249National Aeronautics and Space Administration Grant NAGW-2003Defense Advanced Research Projects Agency/U.S. Army Research Office Grant DAAHO4-951-05643M CorporationDefense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Contract N66001-97-1-8909National Science Foundation Graduate FellowshipU.S. Army Research Office Contract DAAHO4-94-G-0377National Science Foundation Contract DMR-940034National Science Foundation Grant DMR 94-00334Defense Advanced Research Projects Agency/U.S. Air Force - Office of Scientific Research Contract F49620-96-1-0126Harvard-Smithsonian Astrophysical Observatory Contract SV630304National Aeronautics and Space Administration Grant NAG5-5105Los Alamos National Laboratory Contract E57800017-9GSouthwest Research Institute Contract 83832MIT Lincoln Laboratory Advanced Concepts ProgramMIT Lincoln Laboratory Contract BX-655

Zurfer: mobile multimedia access in spatial, social and topical context

What happens when you can access all the world’s media, but the access is constrained by screen size, bandwidth, attention, and battery life? We present a novel mobile contextaware software prototype that enables access to images on the go. Our prototype utilizes the channel metaphor to give users contextual access to media of interest according to key dimensions: spatial, social, and topical. Our experimental prototype attempts to be playful and simple to use, yet provide powerful and comprehensive media access. A temporally-driven sorting scheme for media items allows quick and easy access to items of interest in any dimension. For ad-hoc tasks, we extend the application with keyword search to deliver the long tail of media and images. Elements of social interaction and communication around the photographs are built into the mobile application, to increase user engagement. The application utilizes Flickr.com as an image and social-network data source, but could easily be extended to support other websites and media formats

PADK selectively enhances cathepsin B levels in two transgenic mouse models.

<p>APP_SwInd and APP-PS1 mice were injected i.p. daily with PADK (20 mg/kg; n = 11−13) or vehicle (n = 10) for 9–11 days. Hippocampal homogenates were analyzed by immunoblot and mean immunoreactivities are shown for active cathepsin B (CB), neprilysin (nep), insulin-degrading enzyme (IDE), α-secretase (α-sec), and LAMP1.</p><p>***<i>P</i><0.0001, unpaired t-test.</p

Reduced intracellular Aβ_1–42 staining corresponds with enhanced cathepsin B.

<p>Fixed brain sections from vehicle-treated wildtype mice (wt) and from the APP-PS1 mice treated with vehicle (veh) or PADK were double-stained for Aβ_1–42 (green) and cathepsin B (red). Immunofluorescence images of CA1 pyramidal neurons (arrows) are shown, with view-field widths of 56 µm.</p

PADK has no inhibitory effect on β-secretase activity.

<p>Recombinant human β-secretase (10 ng/ml) was incubated with different concentrations of PADK (open triangles), CA074me (circles), and β-secretase inhibitor IV (closed triangles), and the enzyme activity was determined with the SensiZyme assay kit that uses the procaspase-3 variant containing the β-secretase cleavage sequence Gly-Ser-Ser-Glu-Ile-Ser-Tyr-Glu-Val-Glu-Phe-Arg-Glu-Phe (A). Activity was expressed in absorbance units (mean±SEM), and only β-secretase inhibitor IV elicited inhibition with an IC₅₀ of 19.8±2.4 nM. The three compounds were also tested against cathepsin B activity using the fluorogenic substrate Z-Arg-Arg AMC (mean fluorescence units±SEM plotted). β-secretase inhibitor IV had no effect on the cathepsin B activity, and PADK and CA074me resulted in IC₅₀ values of 9,200±1,030 and 120±13 nM, respectively (B).</p

PADK-mediated reductions of intraneuronal accumulation in the APP_SwInd mice.

<p>Non-transgenic control (wt) and APP_SwInd mice were treated with 9 daily injections of PADK or vehicle. Brain sections were stained with the 6E10 antibody, and photomicrographs indicate PADK-mediated reductions of the intracellular labeling in hippocampal subfields and piriform cortex (A). Image analysis for densitometric quantification was conducted across view-fields of four different neuronal layers (B), and mean integrated optical densities were plotted (±SEM). Individual ANOVAs: <i>P</i><0.0001; Tukey's post hoc tests compared to APP_SwInd+vehicle: **<i>P</i><0.001. Size bar: 40 µm, CA1 and DG; 65 µm, piriform cortex. DG, dentate gyrus; sg, stratum granulosum; sp, stratum pyramidale.</p