52 research outputs found

    A Modular BAM Complex in the Outer Membrane of the α-Proteobacterium Caulobacter crescentus

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    Mitochondria are organelles derived from an intracellular α-proteobacterium. The biogenesis of mitochondria relies on the assembly of β-barrel proteins into the mitochondrial outer membrane, a process inherited from the bacterial ancestor. Caulobacter crescentus is an α-proteobacterium, and the BAM (β-barrel assembly machinery) complex was purified and characterized from this model organism. Like the mitochondrial sorting and assembly machinery complex, we find the BAM complex to be modular in nature. A ∼150 kDa core BAM complex containing BamA, BamB, BamD, and BamE associates with additional modules in the outer membrane. One of these modules, Pal, is a lipoprotein that provides a means for anchorage to the peptidoglycan layer of the cell wall. We suggest the modular design of the BAM complex facilitates access to substrates from the protein translocase in the inner membrane

    Gene and protein expression of O-GlcNAc-cycling enzymes in human laryngeal cancer

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    Aberrant protein O-GlcNAcylation may contribute to the development and malignant behavior of many cancers. This modification is controlled by O-linked β-N-acetylglucosamine transferase (OGT) and O-GlcNAcase (OGA). The aim of this study was to determine the expression of O-GlcNAc cycling enzymes mRNA/protein and to investigate their relationship with clinicopathological parameters in laryngeal cancer. The mRNA levels of OGT and MGEA5 genes were determined in 106 squamous cell laryngeal cancer (SCLC) cases and 73 non-cancerous adjacent laryngeal mucosa (NCLM) controls using quantitative real-time PCR. The level of OGT and OGA proteins was analyzed by Western blot. A positive expression of OGT and MGEA5 transcripts and OGT and OGA proteins was confirmed in 75.5 and 68.9 % and in 43.7 and 59.4 % samples of SCLC, respectively. Higher levels of mRNA/protein for both OGT and OGA as well as significant increases of 60 % in total protein O-GlcNAcylation levels were noted in SCLC compared with NCLM (p < 0.05). As a result, an increased level of OGT and MGEA5 mRNA was related to larger tumor size, nodal metastases, higher grade and tumor behavior according to TFG scale, as well as incidence of disease recurrence (p < 0.05). An inverse association between OGT and MGEA5 transcripts was determined with regard to prognosis (p < 0.05). In addition, the highest OGT and OGA protein levels were observed in poorly differentiated tumors (p < 0.05). No correlations with other parameters were noted, but the results showed a trend of more advanced tumors to be more frequently OGT and OGA positive. The results suggest that increased O-GlcNAcylation may have an effect on tumor aggressiveness and prognosis in laryngeal cancer.This work was supported, in part, by a grant from the National Science Council, Poland (N403 043 32/2326), by the statutory fund of the Department of Cytobiochemistry, University of Łódź, Poland (506/811

    In-depth interviews of patients with primary immunodeficiency who have experienced pump and rapid push subcutaneous infusions of immunoglobulins reveal new insights on their preference and expectations

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    Gr&eacute;goire Jacques No&euml;l Cozon,1 Pierre Clerson,2 Anna&iuml;k Dokhan,3 Yann Fardini,2 Taylor Pindi Sala,4 Jean-Charles Crave4 1Department of Clinical Immunology and Rheumatology, Edouard Herriot Hospital, Lyon, France; 2Soladis Clinical Studies, Roubaix, France; 3KPL, Paris, France; 4Octapharma France, Boulogne, France Purpose: Patients with primary immunodeficiency (PID) often receive immunoglobulin replacement therapy (IgRT). Physicians and patients have the choice between various methods of administration. For subcutaneous immunoglobulin infusions, patients may use an automated pump (P) or push the plunger of a syringe (rapid push [RP]). P infusions are performed once a week and last around 1 hour. RP decreases the duration of administration, but requires more frequent infusions.Patients and methods: Eight out of 30 patients (coming from a single center) who had participated in the cross-over, randomized, open-label trial comparing P and RP participated in a focus group or underwent in-depth interviews. Patients had a long history of home-based subcutaneous immunoglobulin using P. The trial suggested that RP had slightly greater interference on daily life than P, but similar efficacy and better cost-effectiveness. When asked about the delivery method they had preferred, around one-third of patients pointed out RP rather than P. In-depth interviews may reveal unforeseen reasons for patients&rsquo; preferences. Results: Interviews underlined the complexity of the relationship that the patients maintain with their disease and IgRT. Even if they recognized the genetic nature of the disease and claimed PID was a part of them, patients tried not to be overwhelmed by the disease. IgRT by P was well integrated in patients&rsquo; routine. By contrast, RP too frequently reminded the patients of their disease. In addition, some patients pointed out the difficulty of pushing the plunger due to the viscosity of the product. Coming back too frequently, RP was not perceived as time saving over a week. Long-lasting use of P could partly explain patients&rsquo; reasonable reluctance to change to RP.Conclusion: In-depth interviews of PID patients highlighted unforeseen reasons for patients&rsquo; preference that the physician needs to explore during the shared medical decision-making process. Keywords: in-depth interviews, primary immunodeficiency, patients&rsquo; expectations, preference, immunoglobulins, immunoglobulins replacement therapy, pump, rapid push, syring

    Functional Roles of O-GlcNAc in Cell Signaling

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    How nutrition and the maternal microbiota shape the neonatal immune system.

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    The mucosal surfaces of mammals are densely colonized with microorganisms that are commonly referred to as the commensal microbiota. It is believed that the fetus in utero is sterile and that colonization with microorganisms starts only after birth. Nevertheless, the unborn fetus is exposed to a multitude of metabolites that originate from the commensal microbiota of the mother that reach systemic sites of the maternal body. The intestinal microbiota is strongly personalized and influenced by environmental factors, including nutrition. Members of the maternal microbiota can metabolize dietary components, pharmaceuticals and toxins, which can subsequently be passed to the developing fetus or the breast-feeding neonate. In this Review, we discuss the complex interplay between nutrition, the maternal microbiota and ingested chemicals, and summarize their effects on immunity in the offspring
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