101 research outputs found

    Caveolin-3 differentially orchestrates cholinergic and serotonergic constriction of murine airways

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    The mechanisms of controlling airway smooth muscle (ASM) tone are of utmost clinical importance as inappropriate constriction is a hallmark in asthma and chronic obstructive pulmonary disease. Receptors for acetylcholine and serotonin, two relevant mediators in this context, appear to be incorporated in specialized, cholesterol-rich domains of the plasma membrane, termed caveolae due to their invaginated shape. The structural protein caveolin-1 partly accounts for anchoring of these receptors. We here determined the role of the other major caveolar protein, caveolin-3 (cav-3), in orchestrating cholinergic and serotonergic ASM responses, utilizing newly generated cav-3 deficient mice. Cav-3 deficiency fully abrogated serotonin-induced constriction of extrapulmonary airways in organ baths while leaving intrapulmonary airways unaffected, as assessed in precision cut lung slices. The selective expression of cav-3 in tracheal, but not intrapulmonary bronchial epithelial cells, revealed by immunohistochemistry, might explain the differential effects of cav-3 deficiency on serotonergic ASM constriction. The cholinergic response of extrapulmonary airways was not altered, whereas a considerable increase was observed in cav-3â -/- intrapulmonary bronchi. Thus, cav-3 differentially organizes serotonergic and cholinergic signaling in ASM through mechanisms that are specific for airways of certain caliber and anatomical position. This may allow for selective and site-specific intervention in hyperreactive states

    Metabolomic Characterization of Human Model of Liver Rejection Identifies Aberrancies Linked to Cyclooxygenase (COX) and Nitric Oxide Synthase (NOS)

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    BACKGROUND Acute liver rejection (ALR), a significant complication of liver transplantation, burdens patients, healthcare payers, and the healthcare providers due to an increase in morbidity, cost, and resources. Despite clinical resolution, ALR is associated with an increased risk of graft loss. A unique protocol of delayed immunosuppression used in our institute provided a model to characterize metabolomic profiles in human ALR. MATERIAL AND METHODS Twenty liver allograft biopsies obtained 48 hours after liver transplantation in the absence of immunosuppression were studied. Hepatic metabolites were quantitated in these biopsies by liquid chromatography and mass spectroscopy (LC/MS). Metabolite profiles were compared among: 1) biopsies with reperfusion injury but no histological evidence of rejection (n=7), 2) biopsies with histological evidence of moderate or severe rejection (n=5), and 3) biopsies with histological evidence of mild rejection (n=8). RESULTS There were 133 metabolites consistently detected by LC/MS and these were prioritized using variable importance to projection (VIP) analysis, comparing moderate or severe rejection vs. no rejection or mild rejection using partial least squares discriminant statistical analysis (PLS-DA). Twenty metabolites were identified as progressively different. Further PLS-DA using these metabolites identified 3 metabolites (linoleic acid, γ-linolenic acid, and citrulline) which are associated with either cyclooxygenase or nitric oxide synthase functionality. CONCLUSIONS Hepatic metabolic aberrancies associated with cyclooxygenase and nitric oxide synthase function occur contemporaneous with ALR. Additional studies are required to better characterize the role of these metabolic pathways to enhance utility of the metabolomics approach in diagnosis and outcomes of ALR

    LAPORAN INDIVIDU PRAKTIK PENGALAMAN LAPANGAN (PPL) Periode 10 Agustus – 12 September 2015 Lokasi : SMA NEGERI 2SLEMAN

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    Mata kuliah PPL pada dasarnya dapat memberikan life skill bagi mahasiswa, yaitu pengalaman belajar yang kaya, dapat memperluas wawasan, melatih dan mengembangkan kompetensi yang diperlukan dalam bidangnya, meningkatkan ketrampilan, kemandirian, tanggung jawab, dan kemampuan dalam memecahkan masalah. PPL di sekolah bertujuan untuk memberikan kesempatan kepada mahasiswa untuk mempelajari, mengenal, dan menghayati permasalahan lembaga pendidikan baik yang terkait dengan proses pembelajaran maupun manajerial kelembagaan. Selain itu juga memacu pengembangan sekolah atau lembaga dengan cara menumbuhkan motivasi atas dasar kekuatan sendiri serta meningkatkan hubungan kemitraan antara UNY dan pihak sekolah. Kegiatan PPL di SMA Negeri 2 Sleman, merupakan salah satu kesempatan bagi mahasiswa khususnya mahasiswa jurusan kependidikan dalam mengamalkan ilmu yang telah didapat di bangku kuliah untuk diterapkan secara nyata di lingkungan sekolah. Praktik Pengalaman Lapangan (PPL) bertujuan untuk melatih praktikan dalam menerapkan kemampuannya dan pengetahuannya serta mempraktikkan ilmu yang telah diperoleh selama perkuliahan. Dengan demikian, praktikan diharapkan mempunyai bekal dan pengalaman sebagai calon pendidik yang berkualitas. Dalam kegiatan praktik mengajar di Sekolah, secara langsung praktikan dibimbing oleh guru pembimbing dan dosen pembimbing. Praktikan juga berperan dalam kegiatan sekolah lainnya seperti piket harian. Dengan adanya pengalaman tentang penyelenggaraan sekolah ini diharapkan praktikan mempunyai bekal untuk menjadi tenaga pendidik yang profesiona

    Leading the Way: Investing in Management Development for SME Productivity and Growth: Report by the Expert Group on Future Skills Needs

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    The vision set out for this project is to support and enable a fresh approach to growth for SMEs in Ireland where management development is a key strategic priority for SMEs to drive productivity, sustainability, competitiveness and growth, and prepare for the future of work. This research, carried out between October 2019 and March 2020, identifies 7 key findings outlined in the report

    Porcine iGb3s gene silencing provides minimal benefit for clinical xenotransplantation

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    Background The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1−/− pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1−/− animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1−/− pigs to GGTA1−/−- and A3GalT2−/−-double-knockout pigs. Methods We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3. Results Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing. Conclusions Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral

    Methionine Adenosyltransferase α1 Is Targeted to the Mitochondrial Matrix and Interacts with Cytochrome P450 2E1 to Lower Its Expression

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    Methionine adenosyltransferase α1 (MATα1, encoded by MAT1A) is responsible for hepatic biosynthesis of S‐adenosyl methionine, the principal methyl donor. MATα1 also act as a transcriptional cofactor by interacting and influencing the activity of several transcription factors. Mat1a knockout (KO) mice have increased levels of cytochrome P450 2E1 (CYP2E1), but the underlying mechanisms are unknown. The aims of the current study were to identify binding partners of MATα1 and elucidate how MATα1 regulates CYP2E1 expression. We identified binding partners of MATα1 by coimmunoprecipitation (co‐IP) and mass spectrometry. Interacting proteins were confirmed using co‐IP using recombinant proteins, liver lysates, and mitochondria. Alcoholic liver disease (ALD) samples were used to confirm relevance of our findings. We found that MATα1 negatively regulates CYP2E1 at mRNA and protein levels, with the latter being the dominant mechanism. MATα1 interacts with many proteins but with a predominance of mitochondrial proteins including CYP2E1. We found that MATα1 is present in the mitochondrial matrix of hepatocytes using immunogold electron microscopy. Mat1a KO hepatocytes had reduced mitochondrial membrane potential and higher mitochondrial reactive oxygen species, both of which were normalized when MAT1A was overexpressed. In addition, KO hepatocytes were sensitized to ethanol and tumor necrosis factor α–induced mitochondrial dysfunction. Interaction of MATα1 with CYP2E1 was direct, and this facilitated CYP2E1 methylation at R379, leading to its degradation through the proteasomal pathway. Mat1a KO livers have a reduced methylated/total CYP2E1 ratio. MATα1’s influence on mitochondrial function is largely mediated by its effect on CYP2E1 expression. Patients with ALD have reduced MATα1 levels and a decrease in methylated/total CYP2E1 ratio. Conclusion: Our findings highlight a critical role of MATα1 in regulating mitochondrial function by suppressing CYP2E1 expression at multiple levels

    Novel interactions of transglutaminase-2 with heparan sulphate proteoglycans: reflection on physiological implications

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    This mini-review brings together information from publications and recent conference proceedings that have shed light on the biological interaction between transglutaminase-2 and heparan sulphate proteoglycans. We subsequently draw hypothesis of possible implications in the wound healing process. There is a substantial overlap in the action of transglutaminase-2 and the heparan sulphate proteoglycan syndecan-4 in normal and abnormal wound repair. Our latest findings have identified syndecan-4 as a possible binding and signalling partner of fibronectinbound TG2 and support the idea that transglutaminase-2 and syndecan-4 acts in synergy
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