33 research outputs found

    Glioblastoma stem cells express non-canonical proteins and exclusive mesenchymal-like or non-mesenchymal-like protein signatures

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    Glioblastoma (GBM) cancer stem cells (GSCs) contribute to GBM's origin, recurrence, and resistance to treatment. However, the understanding of how mRNA expression patterns of GBM subtypes are reflected at global proteome level in GSCs is limited. To characterize protein expression in GSCs, we performed in-depth proteogenomic analysis of patient-derived GSCs by RNA-sequencing and mass-spectrometry. We quantified > 10 000 proteins in two independent GSC panels and propose a GSC-associated proteomic signature characterizing two distinct phenotypic conditions; one defined by proteins upregulated in proneural and classical GSCs (GPC-like), and another by proteins upregulated in mesenchymal GSCs (GM-like). The GM-like protein set in GBM tissue was associated with necrosis, recurrence, and worse overall survival. Through proteogenomics, we discovered 252 non-canonical peptides in the GSCs, i.e., protein sequences that are variant or derive from genome regions previously considered non-protein-coding, including variants of the heterogeneous ribonucleoproteins implicated in RNA splicing. In summary, GSCs express two protein sets that have an inverse association with clinical outcomes in GBM. The discovery of non-canonical protein sequences questions existing gene models and pinpoints new protein targets for research in GBM

    Long-Term Gene Therapy Causes Transgene-Specific Changes in the Morphology of Regenerating Retinal Ganglion Cells

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    Recombinant adeno-associated viral (rAAV) vectors can be used to introduce neurotrophic genes into injured CNS neurons, promoting survival and axonal regeneration. Gene therapy holds much promise for the treatment of neurotrauma and neurodegenerative diseases; however, neurotrophic factors are known to alter dendritic architecture, and thus we set out to determine whether such transgenes also change the morphology of transduced neurons. We compared changes in dendritic morphology of regenerating adult rat retinal ganglion cells (RGCs) after long-term transduction with rAAV2 encoding: (i) green fluorescent protein (GFP), or (ii) bi-cistronic vectors encoding GFP and ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF) or growth-associated protein-43 (GAP43). To enhance regeneration, rats received an autologous peripheral nerve graft onto the cut optic nerve of each rAAV2 injected eye. After 5–8 months, RGCs with regenerated axons were retrogradely labeled with fluorogold (FG). Live retinal wholemounts were prepared and GFP positive (transduced) or GFP negative (non-transduced) RGCs injected iontophoretically with 2% lucifer yellow. Dendritic morphology was analyzed using Neurolucida software. Significant changes in dendritic architecture were found, in both transduced and non-transduced populations. Multivariate analysis revealed that transgenic BDNF increased dendritic field area whereas GAP43 increased dendritic complexity. CNTF decreased complexity but only in a subset of RGCs. Sholl analysis showed changes in dendritic branching in rAAV2-BDNF-GFP and rAAV2-CNTF-GFP groups and the proportion of FG positive RGCs with aberrant morphology tripled in these groups compared to controls. RGCs in all transgene groups displayed abnormal stratification. Thus in addition to promoting cell survival and axonal regeneration, vector-mediated expression of neurotrophic factors has measurable, gene-specific effects on the morphology of injured adult neurons. Such changes will likely alter the functional properties of neurons and may need to be considered when designing vector-based protocols for the treatment of neurotrauma and neurodegeneration

    The effectiveness of proactive telephone support provided to breastfeeding mothers of preterm infants: Study protocol for a randomized controlled trial

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    Background: Although breast milk has numerous benefits for infants' development, with greater effects in those born preterm (at < 37 gestational weeks), mothers of preterm infants have shorter breastfeeding duration than mothers of term infants. One of the explanations proposed is the difficulties in the transition from a Neonatal Intensive Care Unit (NICU) to the home environment. A person-centred proactive telephone support intervention after discharge from NICU is expected to promote mothers' sense of trust in their own capacity and thereby facilitate breastfeeding. Methods/design: A multicentre randomized controlled trial has been designed to evaluate the effectiveness and cost-effectiveness of person-centred proactive telephone support on breastfeeding outcomes for mothers of preterm infants. Participating mothers will be randomized to either an intervention group or control group. In the intervention group person-centred proactive telephone support will be provided, in which the support team phones the mother daily for up to 14 days after hospital discharge. In the control group, mothers are offered a person-centred reactive support where mothers can phone the breastfeeding support team up to day 14 after hospital discharge. The intervention group will also be offered the same reactive telephone support as the control group. A stratified block randomization will be used; group allocation will be by high or low socioeconomic status and by NICU. Recruitment will be performed continuously until 1116 mothers (I: 558 C: 558) have been included. Primary outcome: proportion of mothers exclusively breastfeeding at eight weeks after discharge. Secondary outcomes: proportion of breastfeeding (exclusive, partial, none and method of feeding), mothers satisfaction with breastfeeding, attachment, stress and quality of life in mothers/partners at eight weeks after hospital discharge and at six months postnatal age. Data will be collected by researchers blind to group allocation for the primary outcome. A qualitative evaluation of experiences of receiving/providing the intervention will also be undertaken with mothers and staff. Discussion: This paper presents the rationale, study design and protocol for a RCT providing person-centred proactive telephone support to mothers of preterm infants. Furthermore, with a health economic evaluation, the cost-effectiveness of the intervention will be assessed

    Inactivation of Pmel Alters Melanosome Shape But Has Only a Subtle Effect on Visible Pigmentation

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    PMEL is an amyloidogenic protein that appears to be exclusively expressed in pigment cells and forms intralumenal fibrils within early stage melanosomes upon which eumelanins deposit in later stages. PMEL is well conserved among vertebrates, and allelic variants in several species are associated with reduced levels of eumelanin in epidermal tissues. However, in most of these cases it is not clear whether the allelic variants reflect gain-of-function or loss-of-function, and no complete PMEL loss-of-function has been reported in a mammal. Here, we have created a mouse line in which the Pmel gene has been inactivated (Pmel−/−). These mice are fully viable, fertile, and display no obvious developmental defects. Melanosomes within Pmel−/− melanocytes are spherical in contrast to the oblong shape present in wild-type animals. This feature was documented in primary cultures of skin-derived melanocytes as well as in retinal pigment epithelium cells and in uveal melanocytes. Inactivation of Pmel has only a mild effect on the coat color phenotype in four different genetic backgrounds, with the clearest effect in mice also carrying the brown/Tyrp1 mutation. This phenotype, which is similar to that observed with the spontaneous silver mutation in mice, strongly suggests that other previously described alleles in vertebrates with more striking effects on pigmentation are dominant-negative mutations. Despite a mild effect on visible pigmentation, inactivation of Pmel led to a substantial reduction in eumelanin content in hair, which demonstrates that PMEL has a critical role for maintaining efficient epidermal pigmentation

    Functional loss of IÎșBΔ leads to NF-ÎșB deregulation in aggressive chronic lymphocytic leukemia

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    NF-ÎșB is constitutively activated in chronic lymphocytic leukemia (CLL); however, the implicated molecular mechanisms remain largely unknown. Thus, we performed targeted deep sequencing of 18 core complex genes within the NF-ÎșB pathway in a discovery and validation CLL cohort totaling 315 cases. The most frequently mutated gene was NFKBIE (21/315 cases; 7%), which encodes IÎșBΔ, a negative regulator of NF-ÎșB in normal B cells. Strikingly, 13 of these cases carried an identical 4-bp frameshift deletion, resulting in a truncated protein. Screening of an additional 377 CLL cases revealed that NFKBIE aberrations predominated in poor-prognostic patients and were associated with inferior outcome. Minor subclones and/or clonal evolution were also observed, thus potentially linking this recurrent event to disease progression. Compared with wild-type patients, NFKBIE-deleted cases showed reduced IÎșBΔ protein levels and decreased p65 inhibition, along with increased phosphorylation and nuclear translocation of p65. Considering the central role of B cell receptor (BcR) signaling in CLL pathobiology, it is notable that IÎșBΔ loss was enriched in aggressive cases with distinctive stereotyped BcR, likely contributing to their poor prognosis, and leading to an altered response to BcR inhibitors. Because NFKBIE deletions were observed in several other B cell lymphomas, our findings suggest a novel common mechanism of NF-ÎșB deregulation during lymphomagenesis

    The Initial Oxide Scale Development on a Model FeNiCrAl Alloy at 900 degrees C in Dry and Humid Atmosphere: A Detailed Investigation

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    The investigated alumina forming FeNiCrAl model alloy shows protective oxidation behavior in dry and humid environment at 900 A degrees C. Hence, this type of alloy may replace conventional chromia forming austenitic alloys in aggressive oxidizing/reducing environments. A detailed investigation of the oxide scale development reveals a complex initial scale development. Firstly, at alloy grain boundaries, a thin Al rich oxide forms which is replaced by transient alumina platelets in dry and equiaxed alpha-Al2O3 crystallites in humid atmosphere. The scale at alloy grain centers develops via a layered scale of external chromia:Fe/Ni metal inclusions:internal alumina to a layered external spinel:internal alumina scale in dry atmosphere. In humid condition an additional oxide feature appears on the center of large alloy grains i.e. thick oxide protrusions. Despite the initially different phase compositions a continuous protective alpha-Al2O3 scale forms both atmospheres

    Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 Gene Editing Technique in Xenotransplantation

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    Genetically modified pigs have been considered favorable resources in xenotransplantation. Microinjection of randomly integrating transgenes into zygotes, somatic cell nuclear transfer, homologous recombination, zinc finger nucleases, transcription activator-like effector nucleases, and most recently, clustered regularly interspaced short palindromic repeats-cas9 (CRISPR/Cas9) are the techniques that have been used to generate these animals. Here, we provide an overview of the CRISPR approaches that have been used to modify genes which are vital in improving xenograft survival rate, including cytidine monophosphate-N-acetylneuraminic acid hydroxylase, B1,4N-acetylgalactosaminyltransferase, isoglobotrihexosylceramide synthase, class I MHC, von Willebrand factor, C3, and porcine endogenous retroviruses. In addition, we will mention the importance of potential candidate genes which could be targeted using CRISPR/Cas9
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