1,613 research outputs found

    Upregulation of chondroitin 6-sulphotransferase-1 facilities Schwann cell migration during axonal growth

    Get PDF
    Cell migration is central to development and posttraumatic regeneration. The differential increase in 6-sulphated chondroitins during axonal growth in both crushed sciatic nerves and brain development suggests that chondroitin 6-sulphotransferase-1 (C6ST-1) is a key enzyme that mediates cell migration in the process. We have cloned the cDNA of the C6ST-1 gene (C6st1) (GenBank accession number AF178689) from crushed sciatic nerves of adult rats and produced ribonucleotide probes accordingly to track signs of 6-sulphated chondroitins at the site of injury. We found C6st1 mRNA expression in Schwann cells emigrating from explants of both sciatic nerve segments and embryonic dorsal root ganglia. Immunocytochemistry indicated pericellular 6-sulphated chondroitin products around C6ST-1-expressing frontier cells. Motility analysis of frontier cells in cultures subjected to staged treatment with chondroitinase ABC indicated that freshly produced 6-sulphated chondroitin moieties facilitated Schwann cell motility, unlike restrictions resulting from proteoglycan interaction with matrix components. Sciatic nerve crush provided further evidence of in vivo upregulation of the C6ST-1 gene in mobile Schwann cells that guided axonal regrowth 1-14 days post crush; downregulation then accompanied declining mobility of Schwann cells as they engaged in the myelination of re-growing axons. These findings are the first to identify upregulated C6st1 gene expression correlating with the motility of Schwann cells that guide growing axons through both developmental and injured environments.published_or_final_versio

    Crystallization and preliminary X-ray crystallographic analysis of SEDL

    Get PDF
    SEDL (known also as sedlin) is a 140 amino-acid protein with a putative role in endoplasmic reticulum-to-Golgi transport. Several missense mutations and deletion mutations in the SEDL gene, which result in protein truncation by frame shift, are responsible for spondyloepiphyseal dysplasia tarda, a progressive skeletal disorder. The protein is identical to MIP-2A, which was shown to interact physically with c-myc promotor-binding protein 1 (MBP-1) and relieve the regulatory role of MBP-1 as a general transcription repressor. In order to gain insights into the function of SEDL by structural analysis, the protein was overexpressed and crystallized as a first step. SEDL was overexpressed in Escherichia coli and crystallized using the hanging-drop vapour-diffusion method at 298 K. The crystals belong to the orthorhombic space group C2221, with unit-cell parameters a = 46.69, b = 101.30, c = 66.15 A. The unit cell is likely to contain one molecule of SEDL, with a crystal volume per protein mass (VM) of 2.36 A3 Da-1 and a solvent content of about 47.9% by volume. A native data set to 2.8 A resolution was obtained from a flash-cooled crystal using synchrotron radiation.open1

    Noninvasive imaging of radiolabeled exosome-mimetic nanovesicle using Tc-99m-HMPAO

    Get PDF
    Exosomes known as nano-sized extracellular vesicles attracted recent interests due to their potential usefulness in drug delivery. Amid remarkable advances in biomedical applications of exosomes, it is crucial to understand in vivo distribution and behavior of exosomes. Here, we developed a simple method for radiolabeling of macrophage-derived exosome-mimetic nanovesicles (ENVs) with Tc-99m-HMPAO under physiologic conditions and monitored in vivo distribution of Tc-99m-HMPAO-ENVs using SPECT/CT in living mice. ENVs were produced from the mouse RAW264.7 macrophage cell line and labeled with Tc-99m-HMPAO for 1 hr incubation, followed by removal of free Tc-99m-HMPAO. SPECT/CT images were serially acquired after intravenous injection to BALB/c mouse. When ENVs were labeled with Tc-99m-HMPAO, the radiochemical purity of Tc-99m-HMPAO-ENVs was higher than 90% and the expression of exosome specific protein (CD63) did not change in Tc-99m-HMPAO-ENVs. Tc-99m-HMPAOENVs showed high serum stability (90%) which was similar to that in phosphate buffered saline until 5 hr. SPECT/CT images of the mice injected with Tc-99m-HMPAO-ENVs exhibited higher uptake in liver and no uptake in brain, whereas mice injected with Tc-99m-HMPAO showed high brain uptake until 5 hr. Our noninvasive imaging of radiolabeled-ENVs promises better understanding of the in vivo behavior of exosomes for upcoming biomedical application.114327Ysciescopu

    Moxifloxacin: Clinically compatible contrast agent for multiphoton imaging

    Get PDF
    Multiphoton microscopy (MPM) is a nonlinear fluorescence microscopic technique widely used for cellular imaging of thick tissues and live animals in biological studies. However, MPM application to human tissues is limited by weak endogenous fluorescence in tissue and cytotoxicity of exogenous probes. Herein, we describe the applications of moxifloxacin, an FDA-approved antibiotic, as a cell-labeling agent for MPM. Moxifloxacin has bright intrinsic multiphoton fluorescence, good tissue penetration and high intracellular concentration. MPM with moxifloxacin was demonstrated in various cell lines, and animal tissues of cornea, skin, small intestine and bladder. Clinical application is promising since imaging based on moxifloxacin labeling could be 10 times faster than imaging based on endogenous fluorescence.1152sciescopu

    Clinical significance of amyloid β positivity in patients with probable cerebral amyloid angiopathy markers

    Get PDF
    Purpose: We investigated the frequency and clinical significance of amyloid β (Aβ) positivity on PET in patients with cerebral amyloid angiopathy (CAA). / Methods: We recruited 65 patients who met the modified Boston criteria for probable CAA. All underwent amyloid PET, MRI, APOE genotyping and neuropsychological testing, and we obtained information on MRI markers of CAA and ischemic cerebral small-vessel disease (CSVD). We investigated the CAA/ischemic CSVD burden and APOE genotypes in relation to Aβ positivity and investigated the effect of Aβ positivity on longitudinal cognitive decline. / Results: Among the 65 CAA patients, 43 (66.2%) showed Aβ PET positivity (Aβ+). Patients with Aβ+ CAA had more lobar microbleeds (median 9, interquartile range 2–41, vs. 3, 2–8; P = 0.045) and a higher frequency of cortical superficial siderosis (34.9% vs. 9.1%; P = 0.025), while patients with Aβ− CAA had more lacunes (1, 0–2, vs. 0, 0–1; P = 0.029) and a higher frequency of severe white matter hyperintensities (45.5% vs. 20.9%; P = 0.040). The frequency of ε4 carriers was higher in Aβ+ patients (57.1%) than in Aβ− patients (18.2%; P = 0.003), while the frequency of ε2 carriers did not differ between the two groups. Finally, Aβ positivity was associated with faster decline in multiple cognitive domains including language (P < 0.001), visuospatial function (P < 0.001), and verbal memory (P < 0.001) in linear mixed effects models. / Conclusion: Our findings suggest that a significant proportion of patients with probable CAA in a memory clinic are Aβ− on PET. Aβ positivity in CAA patients is associated with a distinct pattern of CSVD biomarker expression, and a worse cognitive trajectory. Aβ positivity has clinical relevance in CAA and might represent either advanced CAA or additional Alzheimer’s disease neuropathological changes

    Performance analysis of MIMO-SESS with Alamouti scheme over Rayleigh fading channels

    Get PDF
    Las unidades fraseológicas han estado presentes en los repertorios desde los comienzos de la lexicografía. Y no solamente en los diccionarios generales, sino también en las catalogaciones especializadas, tanto de naturaleza monolingüe como bilingüe. No obstante, siempre ha existido dificultad terminológica para la categorización de los diferentes fenómenos del discurso repetido. Si bien esto no ha sido un inconveniente para que se hayan publicado numerosas compilaciones, sobre todo de refranes en un principio, ya que en la actualidad, fundamentalmente, gracias al auge de los estudios teóricos sobre fraseología, han proliferado otras obras (algunas aplicadas a la glosodidáctica, dada su importancia hoy en día) en las que se da cabida con mayor frecuencia a enunciados de valor específico y a locuciones; en unas ocasiones, ahondando en el origen que les dio entidad y, en otras, estableciendo etiquetados precisos que hasta el momento solían estar ausentes, pero con la finalidad, al fin y al cabo, de desentrañar el sentido, dada la escasa deducibilidad que presentan estas secuencias fijadas por la simple suma de sus elementos constitutivos. Un análisis de estos repertorios a través de los siglos, es, por tanto, el objetivo de este trabajo.Since the beginning of lexicography, phraseological units have been included in repertoires; not only in general dictionaries, but also in monolingual and bilingual specialized catalogues. However, there have always been terminological difficulties for classifying various phenomena of repeated speech. Although this has not been inconvenient for publishing many compilations of sayings, especially at the beginning, because nowadays they frequently include utterances with precise value and idioms, mainly due to the rise of theoretical studies on phraseology (some applied to ASL Linguistics, given its importance today). In them, sometimes, the origin of the phraseological unit is included and, in others, accurate labels that were absent before are determined in order, finally and ultimately, to unravel the meaning, given the reduced deductibility that these sequences present from the simple sum of their constituent elements. The objective of this work is, therefore, an analysis of these repertories throughout the centuries

    Can electrocoagulation process be an appropriate technology for phosphorus removal from municipal wastewater?

    Full text link
    © 2016 Elsevier B.V. This paper evaluated a novel pilot scale electrocoagulation (EC) system for improving total phosphorus (TP) removal from municipal wastewater. This EC system was operated in continuous and batch operating mode under differing conditions (e.g. flow rate, initial concentration, electrolysis time, conductivity, voltage) to evaluate correlative phosphorus and electrical energy consumption. The results demonstrated that the EC system could effectively remove phosphorus to meet current stringent discharge standards of less than 0.2 mg/L within 2 to 5 min. This target was achieved in all ranges of initial TP concentrations studied. It was also found that an increase in conductivity of solution, voltages, or electrolysis time, correlated with improved TP removal efficiency and reduced specific energy consumption. Based on these results, some key economic considerations, such as operating costs, cost-effectiveness, product manufacturing feasibility, facility design and retrofitting, and program implementation are also discussed. This EC process can conclusively be highly efficient in a relatively simple, easily managed, and cost-effective for wastewater treatment system

    Gut microbe-derived extracellular vesicles induce insulin resistance, thereby impairing glucose metabolism in skeletal muscle

    Get PDF
    Gut microbes might influence host metabolic homeostasis and contribute to the pathogenesis of type 2 diabetes (T2D), which is characterized by insulin resistance. Bacteria-derived extracellular vesicles (EVs) have been suggested to be important in the pathogenesis of diseases once believed to be noninfectious. Here, we hypothesize that gut microbe-derived EVs are important in the pathogenesis of T2D. In vivo administration of stool EVs from high fat diet (HFD)-fed mice induced insulin resistance and glucose intolerance compared to regular diet (RD)-fed mice. Metagenomic profiling of stool EVs by 16S ribosomal DNA sequencing revealed an increased amount of EVs derived from Pseudomonas panacis (phylum Proteobacteria) in HFD mice compared to RD mice. Interestingly, P. panacis EVs blocked the insulin signaling pathway in both skeletal muscle and adipose tissue. Moreover, isolated P. panacis EVs induced typical diabetic phenotypes, such as glucose intolerance after glucose administration or systemic insulin injection. Thus, gut microbe-derived EVs might be key players in the development of insulin resistance and impairment of glucose metabolism promoted by HFD.11148Ysciescopu

    Large oncosomes contain distinct protein cargo and represent a separate functional class of tumor-derived extracellular vesicles

    Get PDF
    Large oncosomes (LO) are atypically large (1-10 mu m diameter) cancer-derived extracellular vesicles (EVs), originating from the shedding of membrane blebs and associated with advanced disease. We report that 25% of the proteins, identified by a quantitative proteomics analysis, are differentially represented in large and nano-sized EVs from prostate cancer cells. Proteins enriched in large EVs included enzymes involved in glucose, glutamine and amino acid metabolism, all metabolic processes relevant to cancer. Glutamine metabolism was altered in cancer cells exposed to large EVs, an effect that was not observed upon treatment with exosomes. Large EVs exhibited discrete buoyant densities in iodixanol (OptiPrep (TM)) gradients. Fluorescent microscopy of large EVs revealed an appearance consistent with LO morphology, indicating that these structures can be categorized as LO. Among the proteins enriched in LO, cytokeratin 18 (CK18) was one of the most abundant (within the top 5th percentile) and was used to develop an assay to detect LO in the circulation and tissues of mice and patients with prostate cancer. These observations indicate that LO represent a discrete EV type that may play a distinct role in tumor progression and that may be a source of cancer-specific markers.1182Ysciescopu
    corecore