WorldWideScience

Sample records for cd1c bypasses lysosomes

  1. CD1c-Expression by Monocytes - Implications for the Use of Commercial CD1c+ Dendritic Cell Isolation Kits.

    Directory of Open Access Journals (Sweden)

    Martine Schrøder

    Full Text Available Conventional dendritic cells (cDCs comprise a heterogeneous population of cells that are important regulators of immunity and homeostasis. CD1c+ cDCs are present in human blood and tissues, and found to efficiently activate naïve CD4+ T cells. While CD1c is thought to specifically identify this subset of human cDCs, we show here that also classical and intermediate monocytes express CD1c. Accordingly, the commercial CD1c (BDCA-1+ Dendritic Cell Isolation Kit isolates two distinct cell populations from blood: CD1c+CD14- cDCs and CD1c+CD14+ monocytes. CD1c+ cDCs and CD1c+ monocytes exhibited strikingly different properties, including their differential regulation of surface marker expression, their levels of cytokine production, and their ability to stimulate naïve CD4+ T cells. These results demonstrate that a commercial CD1c (BDCA-1+ Dendritic Cell Isolation Kit isolates two functionally different cell populations, which has important implications for the interpretation of previously generated data using this kit to characterize CD1c+ cDCs.

  2. CD1c+ blood dendritic cells have Langerhans cell potential.

    Science.gov (United States)

    Milne, Paul; Bigley, Venetia; Gunawan, Merry; Haniffa, Muzlifah; Collin, Matthew

    2015-01-15

    Langerhans cells (LCs) are self-renewing in the steady state but repopulated by myeloid precursors after injury. Human monocytes give rise to langerin-positive cells in vitro, suggesting a potential precursor role. However, differentiation experiments with human lineage-negative cells and CD34(+) progenitors suggest that there is an alternative monocyte-independent pathway of LC differentiation. Recent data in mice also show long-term repopulation of the LC compartment with alternative myeloid precursors. Here we show that, although monocytes are able to express langerin, when cultured with soluble ligands granulocyte macrophage colony-stimulating factor (GM-CSF), transforming growth factor β (TGFβ), and bone morphogenetic protein 7 (BMP7), CD1c(+) dendritic cells (DCs) become much more LC-like with high langerin, Birbeck granules, EpCAM, and E-cadherin expression under the same conditions. These data highlight a new potential precursor function of CD1c(+) DCs and demonstrate an alternative pathway of LC differentiation that may have relevance in vivo.

  3. Residual endotoxin contaminations in recombinant proteins are sufficient to activate human CD1c+ dendritic cells.

    Science.gov (United States)

    Schwarz, Harald; Schmittner, Maria; Duschl, Albert; Horejs-Hoeck, Jutta

    2014-01-01

    Many commercially available recombinant proteins are produced in Escherichia coli, and most suppliers guarantee contamination levels of less than 1 endotoxin unit (EU). When we analysed commercially available proteins for their endotoxin content, we found contamination levels in the same range as generally stated in the data sheets, but also some that were higher. To analyse whether these low levels of contamination have an effect on immune cells, we stimulated the monocytic cell line THP-1, primary human monocytes, in vitro differentiated human monocyte-derived dendritic cells, and primary human CD1c+ dendritic cells (DCs) with very low concentrations of lipopolysaccharide (LPS; ranging from 0.002-2 ng/ml). We show that CD1c+ DCs especially can be activated by minimal amounts of LPS, equivalent to the levels of endotoxin contamination we detected in some commercially available proteins. Notably, the enhanced endotoxin sensitivity of CD1c+ DCs was closely correlated with high CD14 expression levels observed in CD1c+ DCs that had been maintained in cell culture medium for 24 hours. When working with cells that are particularly sensitive to LPS, even low endotoxin contamination may generate erroneous data. We therefore recommend that recombinant proteins be thoroughly screened for endotoxin contamination using the limulus amebocyte lysate test, fluorescence-based assays, or a luciferase based NF-κB reporter assay involving highly LPS-sensitive cells overexpressing TLR4, MD-2 and CD14.

  4. Distinct morphophenotypic features of chronic B-cell leukaemias identified with CD1c and CD23 antibodies.

    Science.gov (United States)

    Orazi, A; Cattoretti, G; Polli, N; Delia, D; Rilke, F

    1991-07-01

    Morphological criteria usually applied to diagnose various subtypes of B-cell chronic lymphoid leukaemia are largely subjective. Immunophenotyping of 61 relevant cases using a selected panel of monoclonal antibodies (mAb), showed that CD1c and CD23 mAb were able to separate B-cell chronic lymphocytic leukaemia (B-CLL) from other chronic B-cell lymphoproliferative diseases. Lymphocytes of B-CLL were CD1c-, CD23+, whereas those of other types of chronic B-cell leukaemia were CD1c+/-, CD23-, and CD38/-. Non-B-CLL cases had a significantly higher amount of large peroxidase-negative (unstained) cells analyzed with an automated blood cell counter (Technicon H6000). This type of volumetric assessment allowed a separation between typical and "atypical" B-CLL, which otherwise were both CD1c-, and CD23+. These combinations of phenotypic markers corresponded to well-defined haematopathologic entities, conventionally diagnosed on peripheral blood (PB) and bone marrow smears, and on histologic sections of lymph nodes and spleen.

  5. Increased tubulointerstitial recruitment of human CD141(hi) CLEC9A(+) and CD1c(+) myeloid dendritic cell subsets in renal fibrosis and chronic kidney disease.

    Science.gov (United States)

    Kassianos, Andrew J; Wang, Xiangju; Sampangi, Sandeep; Muczynski, Kimberly; Healy, Helen; Wilkinson, Ray

    2013-11-15

    Dendritic cells (DCs) play critical roles in immune-mediated kidney diseases. Little is known, however, about DC subsets in human chronic kidney disease, with previous studies restricted to a limited set of pathologies and to using immunohistochemical methods. In this study, we developed novel protocols for extracting renal DC subsets from diseased human kidneys and identified, enumerated, and phenotyped them by multicolor flow cytometry. We detected significantly greater numbers of total DCs as well as CD141(hi) and CD1c(+) myeloid DC (mDCs) subsets in diseased biopsies with interstitial fibrosis than diseased biopsies without fibrosis or healthy kidney tissue. In contrast, plasmacytoid DC numbers were significantly higher in the fibrotic group compared with healthy tissue only. Numbers of all DC subsets correlated with loss of kidney function, recorded as estimated glomerular filtration rate. CD141(hi) DCs expressed C-type lectin domain family 9 member A (CLEC9A), whereas the majority of CD1c(+) DCs lacked the expression of CD1a and DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), suggesting these mDC subsets may be circulating CD141(hi) and CD1c(+) blood DCs infiltrating kidney tissue. Our analysis revealed CLEC9A(+) and CD1c(+) cells were restricted to the tubulointerstitium. Notably, DC expression of the costimulatory and maturation molecule CD86 was significantly increased in both diseased cohorts compared with healthy tissue. Transforming growth factor-β levels in dissociated tissue supernatants were significantly elevated in diseased biopsies with fibrosis compared with nonfibrotic biopsies, with mDCs identified as a major source of this profibrotic cytokine. Collectively, our data indicate that activated mDC subsets, likely recruited into the tubulointerstitium, are positioned to play a role in the development of fibrosis and, thus, progression to chronic kidney disease.

  6. CD1c-Related DCs that Express CD207/Langerin, but Are Distinguishable from Langerhans Cells, Are Consistently Present in Human Tonsils.

    Science.gov (United States)

    De Monte, Anne; Olivieri, Charles-Vivien; Vitale, Sébastien; Bailleux, Sonanda; Castillo, Laurent; Giordanengo, Valérie; Maryanski, Janet L; Segura, Elodie; Doglio, Alain

    2016-01-01

    Several subsets of dendritic cells (DCs) are present in the oropharyngeal tonsillar tissues and are thought to behave as major actors in development and regulation of immunity by acting as a first line of recognition for airborne and alimentary antigens. We previously discovered in human adult tonsils infected with Epstein-Barr virus (EBV), a subset of DCs that expressed langerin/CD207, a lectin usually recognized as a hallmark of epidermal Langerhans cells (LCs). In the present study, we analyzed the content of several child and adult tonsils in order to characterize in more detail the phenotype of these tonsillar CD207-expressing DCs (tCD207 DCs) and to compare it with that of other human DC subsets. We showed that all the human tonsils studied (n = 12) contained significant proportions of tCD207 DCs among tonsillar cells expressing HLA-DR. Moreover, the presence of tCD207 DCs in tonsils from young children free of EBV infection indicated that these cells could be established early in the tonsil independently of EBV infection. We also showed that tCD207 DCs, that were found mainly located within the tonsillar lymphoid stroma, were distinguishable from LCs by the level of expression of CD1a and EpCAM, and also from human inflammatory DCs by the lack of CD1a, CD206, and CD14 expression. Detailed analysis of cell surface DC markers showed that tCD207 DCs were unrelated to CD141(+) DCs or macrophages, but defined a subtype of tonsillar DCs closely related to myeloid resident CD1c DCs. Since it was established that blood CD1c myeloid DCs exhibit plasticity and are capable of expressing CD207 notably in the presence of inflammatory cytokines, it is tempting to speculate that CD207(+) CD1c(+) DCs may play a specific immune role.

  7. CD1c-related DCs that express CD207/langerin, but are distinguishable from Langerhans cells, are consistently present in human tonsils

    Directory of Open Access Journals (Sweden)

    Anne eDe Monte

    2016-05-01

    Full Text Available Several subsets of dendritic cells (DCs are present in the oropharyngeal tonsillar tissues and are thought to behave as major actors in development and regulation of immunity by acting as a first line of recognition for airborne and alimentary antigens. We previously discovered in human adult tonsils infected with Epstein-Barr Virus (EBV a subset of DCs that expressed langerin/CD207, a lectin usually recognized as a hallmark of epidermal Langerhans cells (LCs. In the present study, we analyzed the content of several child and adult tonsils in order to characterize in more detail the phenotype of these tonsillar CD207-expressing DCs (tCD207 DCs and to compare it with that of other human DC subsets. We showed that all the human tonsils studied (n=12 contained significant proportions of tCD207 DCs among tonsillar cells expressing HLA-DR. Moreover, the presence of tCD207 DCs in tonsils from young children free of EBV infection indicated that these cells could be established early in the tonsil independently of EBV infection. We also showed that tCD207 DCs, that were found mainly located within the tonsillar lymphoid stroma, were distinguishable from LCs by the level of expression of CD1a and EpCAM, and also from human inflammatory DCs (infDCs by the lack of CD1a, CD206 and CD14 expression. Detailed analysis of cell surface DC markers showed that tCD207 DCs were unrelated to CD141+ DCs or macrophages, but defined a subtype of tonsillar DCs closely related to myeloid resident CD1c DCs. Since it was established that blood CD1c myeloid DCs exhibit plasticity and are capable of expressing CD207 notably in the presence of inflammatory cytokines, it is tempting to speculate that CD207+ CD1c+ DCs may play a specific immune role.

  8. The proteome of lysosomes.

    Science.gov (United States)

    Schröder, Bernd A; Wrocklage, Christian; Hasilik, Andrej; Saftig, Paul

    2010-11-01

    Lysosomes are organelles of eukaryotic cells that are critically involved in the degradation of macromolecules mainly delivered by endocytosis and autophagocytosis. Degradation is achieved by more than 60 hydrolases sequestered by a single phospholipid bilayer. The lysosomal membrane facilitates interaction and fusion with other compartments and harbours transport proteins catalysing the export of catabolites, thereby allowing their recycling. Lysosomal proteins have been addressed in various proteomic studies that are compared in this review regarding the source of material, the organelle/protein purification scheme, the proteomic methodology applied and the proteins identified. Distinguishing true constituents of an organelle from co-purifying contaminants is a central issue in subcellular proteomics, with additional implications for lysosomes as being the site of degradation of many cellular and extracellular proteins. Although many of the lysosomal hydrolases were identified by classical biochemical approaches, the knowledge about the protein composition of the lysosomal membrane has remained fragmentary for a long time. Using proteomics many novel lysosomal candidate proteins have been discovered and it can be expected that their functional characterisation will help to understand functions of lysosomes at a molecular level that have been characterised only phenomenologically so far and to generally deepen our understanding of this indispensable organelle.

  9. TRPML and lysosomal function.

    Science.gov (United States)

    Zeevi, David A; Frumkin, Ayala; Bach, Gideon

    2007-08-01

    Mucolipin 1 (MLN1), also known as TRPML1, is a member of the mucolipin family. The mucolipins are the only lysosomal proteins within the TRP superfamily. Mutations in the gene coding for TRPML1 result in a lysosomal storage disorder (LSD). This review summarizes the current knowledge related to this protein and the rest of the mucolipin family.

  10. Lysosomal Storage Diseases

    Directory of Open Access Journals (Sweden)

    Joseph Alroy DVM, DACVP

    2014-03-01

    Full Text Available Lysosomal storage diseases are a group of inherited and acquired disorders. They are characterized by interruption of recycling of cellular and extracellular molecules. Clinically, they are presented as developmental and neurological symptoms similar to other inherited and acquired disorders. This article reviews the function of lysosomes, the current mechanisms that cause the interruption of recycling, the consequences that are manifested clinically, and the methods to diagnose these disorders.

  11. IL-10 promotes homeostatic proliferation of human CD8(+) memory T cells and, when produced by CD1c(+) DCs, shapes naive CD8(+) T-cell priming.

    Science.gov (United States)

    Nizzoli, Giulia; Larghi, Paola; Paroni, Moira; Crosti, Maria Cristina; Moro, Monica; Neddermann, Petra; Caprioli, Flavio; Pagani, Massimiliano; De Francesco, Raffaele; Abrignani, Sergio; Geginat, Jens

    2016-07-01

    IL-10 is an anti-inflammatory cytokine that inhibits maturation and cytokine production of dendritic cells (DCs). Although mature DCs have the unique capacity to prime CD8(+) CTL, IL-10 can promote CTL responses. To understand these paradoxic findings, we analyzed the role of IL-10 produced by human APC subsets in T-cell responses. IL-10 production was restricted to CD1c(+) DCs and CD14(+) monocytes. Interestingly, it was differentially regulated, since R848 induced IL-10 in DCs, but inhibited IL-10 in monocytes. Autocrine IL-10 had only a weak inhibitory effect on DC maturation, cytokine production, and CTL priming with high-affinity peptides. Nevertheless, it completely blocked cross-priming and priming with low-affinity peptides of a self/tumor-antigen. IL-10 also inhibited CD1c(+) DC-induced CD4(+) T-cell priming and enhanced Foxp3 induction, but was insufficient to induce T-cell IL-10 production. CD1c(+) DC-derived IL-10 had also no effect on DC-induced secondary expansions of memory CTL. However, IL-15-driven, TCR-independent proliferation of memory CTL was enhanced by IL-10. We conclude that DC-derived IL-10 selects high-affinity CTL upon priming. Moreover, IL-10 preserves established CTL memory by enhancing IL-15-dependent homeostatic proliferation. These combined effects on CTL priming and memory maintenance provide a plausible mechanism how IL-10 promotes CTL responses in humans.

  12. Mice Doubly-deficient in lysosomal hexosaminidase a and neuraminidase 4 show epileptic crises and rapid neuronal loss

    OpenAIRE

    Seyrantepe, Volkan; Lema, Pablo; Caqueret, Aurore; Dridi, Larbi; Hadj, Samar Bel; Carpentier, Stephane; Boucher, Francine; Levade, Thierry; Carmant, Lionel; Gravel, Roy A.; Hamel, Edith; Vachon, Pascal; Di Cristo, Graziella; Michaud, Jacques L.; Morales, Carlos R.

    2010-01-01

    Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the a-subunit of lysosomal β-hexosaminidase A, which converts GM2 to GM3 ganglioside. Hexa-/- mice, depleted of b-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise GM2 ganglioside via a lysosomal sialidase into glycolipid GA2, which is further processed by β-hexosaminidase B to lactosyl-ceramide, thereby bypassing the β-hexosaminidase A defect. Since this bypass is no...

  13. The lysosome and neurodegenerative diseases

    Institute of Scientific and Technical Information of China (English)

    Lisha Zhang; Rui Sheng; Zhenghong Qin

    2009-01-01

    It has long been believed that the lysosome is an important digestive organelle. There is increasing evidence that the lysosome is also involved in pathogenesis of a variety of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Abnormal protein degradation and deposition induced by lysosoreal dysfunction may be the primary contributor to age-related neurodegeneration. In this review, the possible relationship between lysosome and various neurodegenerative diseases is described.

  14. Cancer-associated lysosomal changes

    DEFF Research Database (Denmark)

    Kallunki, T; Olsen, O D; Jaattela, Marja

    2013-01-01

    Rapidly dividing and invasive cancer cells are strongly dependent on effective lysosomal function. Accordingly, transformation and cancer progression are characterized by dramatic changes in lysosomal volume, composition and cellular distribution. Depending on one's point of view, the cancer-associated......-targeting anti-cancer drugs. In this review we compile our current knowledge on cancer-associated changes in lysosomal composition and discuss the consequences of these alterations to cancer progression and the possibilities they can bring to cancer therapy.Oncogene advance online publication, 9 July 2012; doi...

  15. Coronary Artery Bypass Surgery

    Science.gov (United States)

    ... t help, you may need coronary artery bypass surgery. The surgery creates a new path for blood to flow ... more than one bypass. The results of the surgery usually are excellent. Many people remain symptom-free ...

  16. Coronary Artery Bypass

    Science.gov (United States)

    ... to 3 days in the Intensive Care Unit (ICU). Life After Bypass After bypass surgery, your doctor will recommend that you join a cardiac rehabilitation program. These programs help you make lifestyle changes ...

  17. Gastric bypass surgery

    Science.gov (United States)

    ... Roux-en-Y; Weight-loss surgery - gastric bypass; Obesity surgery - gastric bypass ... bypass surgery is not a quick fix for obesity. It will greatly change your lifestyle. After this surgery, you must eat healthy foods, control portion sizes of ...

  18. Lysosomal cell death mechanisms in aging.

    Science.gov (United States)

    Gómez-Sintes, Raquel; Ledesma, María Dolores; Boya, Patricia

    2016-12-01

    Lysosomes are degradative organelles essential for cell homeostasis that regulate a variety of processes, from calcium signaling and nutrient responses to autophagic degradation of intracellular components. Lysosomal cell death is mediated by the lethal effects of cathepsins, which are released into the cytoplasm following lysosomal damage. This process of lysosomal membrane permeabilization and cathepsin release is observed in several physiopathological conditions and plays a role in tissue remodeling, the immune response to intracellular pathogens and neurodegenerative diseases. Many evidences indicate that aging strongly influences lysosomal activity by altering the physical and chemical properties of these organelles, rendering them more sensitive to stress. In this review we focus on how aging alters lysosomal function and increases cell sensitivity to lysosomal membrane permeabilization and lysosomal cell death, both in physiological conditions and age-related pathologies.

  19. Brief exposure to copper activates lysosomal exocytosis.

    Science.gov (United States)

    Peña, Karina; Coblenz, Jessica; Kiselyov, Kirill

    2015-04-01

    Copper (Cu) is essential mineral, but its toxicity necessitates existence of powerful machinery responsible for the extraction of excess Cu from the cell. Cu exposure was recently shown to induce the translocation of Cu pump ATP7B to the lysosomes followed by lysosomal exocytosis. Here we sought to investigate the mechanisms underlying the effect of Cu on lysosomal exocytosis. We found that brief exposure to Cu activates lysosomal exocytosis, which was measured as a release of the lysosomal digestive enzyme β-hexosaminidase (β-hex) into the extracellular medium and by the presence lysosomal protein LAMP1 at the plasma membrane. Such release depends on calcium (Ca) and on the lysosomal SNARE VAMP7. ATP7B knockdown using RNAi suppressed the basal lysosomal exocytosis, but did not affect the ability of Cu to activate it. ATP7B knockdown was associated with sustained oxidative stress. The removal of Ca from the extracellular medium suppressed the Cu-dependent component of the lysosomal exocytosis. We propose that Cu promotes lysosomal exocytosis by facilitating a Ca-dependent step of the lysosomal exocytosis.

  20. Inhibitors of lysosomal cysteine proteases

    Directory of Open Access Journals (Sweden)

    Lyanna O. L.

    2011-04-01

    Full Text Available The review is devoted to the inhibitors of cysteine proteinases which are believed to be very important in many biochemical processes of living organisms. They participate in the development and progression of numerous diseases that involve abnormal protein turnover. One of the main regulators of these proteinases is their specific inhibitors: cystatins. The aim of this review was to present current knowledge about endogenous inhibitors of lysosomal cysteine proteases and their synthetic analogs.

  1. Flood Bypass Capacity Optimization

    Science.gov (United States)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  2. GNeosomes: Highly Lysosomotropic Nanoassemblies for Lysosomal Delivery.

    Science.gov (United States)

    Wexselblatt, Ezequiel; Esko, Jeffrey D; Tor, Yitzhak

    2015-01-01

    GNeosomes, lysosomotropic lipid vesicles decorated with guanidinoneomycin, can encapsulate and facilitate the cellular internalization and lysosomal delivery of cargo ranging from small molecules to high molecular weight proteins, in a process that is exclusively dependent on cell surface glycosaminoglycans. Their cellular uptake mechanism and co-localization with lysosomes, as well as the delivery, release, and activity of internalized cargo, are quantified. GNeosomes are proposed as a universal platform for lysosomal delivery with potential as a basic research tool and a therapeutic vehicle.

  3. Bypassing damaged nervous tissue

    CERN Document Server

    Shneider, M N

    2016-01-01

    We show the principal ability of bypassing damaged demyelinated portions of nervous tissue, thereby restoring its normal function for the passage of action potentials. We carry out a theoretical analysis on the basis of the synchronization mechanism of action potential propagation along a bundle of neurons, proposed recently in [1]. And we discuss the feasibility of implement a bypass to restore damaged nervous tissue and creating an artificial neuron network.

  4. Sensitivity to lysosome-dependent cell death is directly regulated by lysosomal cholesterol content.

    Directory of Open Access Journals (Sweden)

    Hanna Appelqvist

    Full Text Available Alterations in lipid homeostasis are implicated in several neurodegenerative diseases, although the mechanisms responsible are poorly understood. We evaluated the impact of cholesterol accumulation, induced by U18666A, quinacrine or mutations in the cholesterol transporting Niemann-Pick disease type C1 (NPC1 protein, on lysosomal stability and sensitivity to lysosome-mediated cell death. We found that neurons with lysosomal cholesterol accumulation were protected from oxidative stress-induced apoptosis. In addition, human fibroblasts with cholesterol-loaded lysosomes showed higher lysosomal membrane stability than controls. Previous studies have shown that cholesterol accumulation is accompanied by the storage of lipids such as sphingomyelin, glycosphingolipids and sphingosine and an up regulation of lysosomal associated membrane protein-2 (LAMP-2, which may also influence lysosomal stability. However, in this study the use of myriocin and LAMP deficient fibroblasts excluded these factors as responsible for the rescuing effect and instead suggested that primarily lysosomal cholesterol content determineD the cellular sensitivity to toxic insults. Further strengthening this concept, depletion of cholesterol using methyl-β-cyclodextrin or 25-hydroxycholesterol decreased the stability of lysosomes and cells became more prone to undergo apoptosis. In conclusion, cholesterol content regulated lysosomal membrane permeabilization and thereby influenced cell death sensitivity. Our data suggests that lysosomal cholesterol modulation might be used as a therapeutic strategy for conditions associated with accelerated or repressed apoptosis.

  5. A molecular mechanism to regulate lysosome motility for lysosome positioning and tubulation.

    Science.gov (United States)

    Li, Xinran; Rydzewski, Nicholas; Hider, Ahmad; Zhang, Xiaoli; Yang, Junsheng; Wang, Wuyang; Gao, Qiong; Cheng, Xiping; Xu, Haoxing

    2016-04-01

    To mediate the degradation of biomacromolecules, lysosomes must traffic towards cargo-carrying vesicles for subsequent membrane fusion or fission. Mutations of the lysosomal Ca(2+) channel TRPML1 cause lysosomal storage disease (LSD) characterized by disordered lysosomal membrane trafficking in cells. Here we show that TRPML1 activity is required to promote Ca(2+)-dependent centripetal movement of lysosomes towards the perinuclear region (where autophagosomes accumulate) following autophagy induction. ALG-2, an EF-hand-containing protein, serves as a lysosomal Ca(2+) sensor that associates physically with the minus-end-directed dynactin-dynein motor, while PtdIns(3,5)P(2), a lysosome-localized phosphoinositide, acts upstream of TRPML1. Furthermore, the PtdIns(3,5)P(2)-TRPML1-ALG-2-dynein signalling is necessary for lysosome tubulation and reformation. In contrast, the TRPML1 pathway is not required for the perinuclear accumulation of lysosomes observed in many LSDs, which is instead likely to be caused by secondary cholesterol accumulation that constitutively activates Rab7-RILP-dependent retrograde transport. Ca(2+) release from lysosomes thus provides an on-demand mechanism regulating lysosome motility, positioning and tubulation.

  6. Up-regulation of lysosomal TRPML1 channels is essential for lysosomal adaptation to nutrient starvation.

    Science.gov (United States)

    Wang, Wuyang; Gao, Qiong; Yang, Meimei; Zhang, Xiaoli; Yu, Lu; Lawas, Maria; Li, Xinran; Bryant-Genevier, Marthe; Southall, Noel T; Marugan, Juan; Ferrer, Marc; Xu, Haoxing

    2015-03-17

    Upon nutrient starvation, autophagy digests unwanted cellular components to generate catabolites that are required for housekeeping biosynthesis processes. A complete execution of autophagy demands an enhancement in lysosome function and biogenesis to match the increase in autophagosome formation. Here, we report that mucolipin-1 (also known as TRPML1 or ML1), a Ca(2+) channel in the lysosome that regulates many aspects of lysosomal trafficking, plays a central role in this quality-control process. By using Ca(2+) imaging and whole-lysosome patch clamping, lysosomal Ca(2+) release and ML1 currents were detected within hours of nutrient starvation and were potently up-regulated. In contrast, lysosomal Na(+)-selective currents were not up-regulated. Inhibition of mammalian target of rapamycin (mTOR) or activation of transcription factor EB (TFEB) mimicked a starvation effect in fed cells. The starvation effect also included an increase in lysosomal proteostasis and enhanced clearance of lysosomal storage, including cholesterol accumulation in Niemann-Pick disease type C (NPC) cells. However, this effect was not observed when ML1 was pharmacologically inhibited or genetically deleted. Furthermore, overexpression of ML1 mimicked the starvation effect. Hence, lysosomal adaptation to environmental cues such as nutrient levels requires mTOR/TFEB-dependent, lysosome-to-nucleus regulation of lysosomal ML1 channels and Ca(2+) signaling.

  7. BK Channels Alleviate Lysosomal Storage Diseases by Providing Positive Feedback Regulation of Lysosomal Ca2+ Release.

    Science.gov (United States)

    Cao, Qi; Zhong, Xi Zoë; Zou, Yuanjie; Zhang, Zhu; Toro, Ligia; Dong, Xian-Ping

    2015-05-26

    Promoting lysosomal trafficking represents a promising therapeutic approach for lysosome storage diseases. Efficient Ca(2+) mobilization from lysosomes is important for lysosomal trafficking. Ca(2+) release from lysosomes could generate a negative potential in the lumen to disturb subsequent Ca(2+) release in the absence of counter ion flux. Here we report that lysosomes express big-conductance Ca(2+)-activated potassium (BK) channels that form physical and functional coupling with the lysosomal Ca(2+) release channel, TRPML1. Ca(2+) release via TRPML1 causes BK activation, which in turn facilitates further lysosomal Ca(2+) release and membrane trafficking. Importantly, BK overexpression rescues the impaired TRPML1-mediated Ca(2+) release and abnormal lysosomal storage in cells from Niemann-Pick C1 patients. Therefore, we have identified a lysosomal K(+) channel that provides a positive feedback mechanism to facilitate TRPML1-mediated Ca(2+) release and membrane trafficking. Our findings suggest that upregulating BK may be a potential therapeutic strategy for certain lysosomal storage diseases and common neurodegenerative disorders.

  8. Endosome-lysosomes and neurodegeneration.

    Science.gov (United States)

    Mayer, R J; Tipler, C; Laszlo, L; Arnold, J; Lowe, J; Landon, M

    1994-01-01

    A number of the major human and animal neurodegenerative diseases, such as Alzheimer's disease and sheep scrapie, are characterised by deposits of amyloid, arising through incomplete breakdown of membrane proteins. Although our knowledge concerning these diseases is increasing, they remain largely untreatable. Recently, attention has focussed on the mechanisms of production of different types of amyloid and the likely involvement within cells of acid compartments called endosome-lysosomes. These organelles may be 'bioreactor' sites for the unfolding and partial degradation of membrane proteins to generate the amyloid materials. These subsequently become expelled from the cell, or are released from dead cells, and accumulate as pathological entities. Common features of the disease processes give new direction to therapeutic intervention.

  9. Your diet after gastric bypass surgery

    Science.gov (United States)

    Gastric bypass surgery - your diet; Obesity - diet after bypass; Weight loss - diet after bypass ... You had gastric bypass surgery. This surgery made your stomach smaller by closing off most of your stomach with staples. It changed the way your ...

  10. Lysosomal enlargement and lysosomal membrane destabilisation in mussel digestive cells measured by an integrative index

    Energy Technology Data Exchange (ETDEWEB)

    Izagirre, Urtzi [Cell Biology in Environmental Toxicology Research Group, Department of Zoology and Cell Biology, School of Sciences and Technology, University of the Basque Country, P.O. box 644, E-48080 Bilbo (Spain); Marigomez, Ionan, E-mail: ionan.marigomez@ehu.e [Cell Biology in Environmental Toxicology Research Group, Department of Zoology and Cell Biology, School of Sciences and Technology, University of the Basque Country, P.O. box 644, E-48080 Bilbo (Spain)

    2009-05-15

    Lysosomal responses (enlargement and membrane destabilisation) in mussel digestive cells are well-known environmental stress biomarkers in pollution effects monitoring in marine ecosystems. Presently, in laboratory and field studies, both responses were measured separately (in terms of lysosomal volume density - Vv - and labilisation period -LP) and combined (lysosomal response index - LRI) in order to contribute to their understanding and to develop an index useful for decisions makers. LRI integrates Vv and LP, which are not necessarily dependent lysosomal responses. It is unbiased and more sensitive than Vv and LP alone and diminishes background due to confounding factors. LRI provides a simple numerical index (consensus reference = 0; critical threshold = 1) directly related to the pollution impact degree. Moreover, LRI can be represented in a way that allows the interpretation of lysosomal responses, which is useful for environmental scientists. - Lysosomal responses to pollutants measured by an integrative index.

  11. Bypass Flow Study

    Energy Technology Data Exchange (ETDEWEB)

    Richard Schultz

    2011-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  12. Heart bypass surgery - minimally invasive

    Science.gov (United States)

    ... Names Minimally invasive direct coronary artery bypass; MIDCAB; Robot-assisted coronary artery bypass; RACAB; Keyhole heart surgery; ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  13. Presenilin 1 maintains lysosomal Ca2+ homeostasis by regulating vATPase-mediated lysosome acidification

    Science.gov (United States)

    Lee, Ju-Hyun; McBrayer, Mary Kate; Wolfe, Devin M.; Haslett, Luke J.; Kumar, Asok; Sato, Yutaka; Lie, Pearl P. Y.; Mohan, Panaiyur; Coffey, Erin E.; Kompella, Uday; Mitchell, Claire H.; Lloyd-Evans, Emyr; Nixon, Ralph A.

    2015-01-01

    Summary Presenilin-1 (PS1) deletion or Alzheimer’s Disease (AD)-linked mutations disrupt lysosomal acidification and proteolysis, which inhibits autophagy. Here, we establish that this phenotype stems from impaired glycosylation and instability of vATPase V0a1 subunit causing deficient lysosomal vATPase assembly and function. We further demonstrate that elevated lysosomal pH in PS1KO cells induces abnormal Ca2+ efflux from lysosomes mediated by TRPML1 and elevates cytosolic Ca2+. In WT cells, blocking vATPase activity or knockdown of either PS1 or the V0a1 subunit of vATPase reproduces all of these abnormalities. Normalizing lysosomal pH in PS1KO cells using acidic nanoparticles restores normal lysosomal proteolysis, autophagy, and Ca2+ homeostasis, but correcting lysosomal Ca2+ deficits alone neither re-acidifies lysosomes nor reverses proteolytic and autophagic deficits. Our results indicate that vATPase deficiency in PS1 loss of function states causes lysosomal/autophagy deficits and contributes to abnormal cellular Ca2+ homeostasis, thus linking two AD-related pathogenic processes through a common molecular mechanism. PMID:26299959

  14. Lipid storage disorders block lysosomal trafficking by inhibiting a TRP channel and lysosomal calcium release.

    Science.gov (United States)

    Shen, Dongbiao; Wang, Xiang; Li, Xinran; Zhang, Xiaoli; Yao, Zepeng; Dibble, Shannon; Dong, Xian-ping; Yu, Ting; Lieberman, Andrew P; Showalter, Hollis D; Xu, Haoxing

    2012-03-13

    Lysosomal lipid accumulation, defects in membrane trafficking and altered Ca(2+) homoeostasis are common features in many lysosomal storage diseases. Mucolipin transient receptor potential channel 1 (TRPML1) is the principle Ca(2+) channel in the lysosome. Here we show that TRPML1-mediated lysosomal Ca(2+) release, measured using a genetically encoded Ca(2+) indicator (GCaMP3) attached directly to TRPML1 and elicited by a potent membrane-permeable synthetic agonist, is dramatically reduced in Niemann-Pick (NP) disease cells. Sphingomyelins (SMs) are plasma membrane lipids that undergo sphingomyelinase (SMase)-mediated hydrolysis in the lysosomes of normal cells, but accumulate distinctively in lysosomes of NP cells. Patch-clamp analyses revealed that TRPML1 channel activity is inhibited by SMs, but potentiated by SMases. In NP-type C cells, increasing TRPML1's expression or activity was sufficient to correct the trafficking defects and reduce lysosome storage and cholesterol accumulation. We propose that abnormal accumulation of luminal lipids causes secondary lysosome storage by blocking TRPML1- and Ca(2+)-dependent lysosomal trafficking.

  15. The Best Bypass Surgery Trial

    DEFF Research Database (Denmark)

    Møller, Christian H; Jensen, Birte Østergaard; Gluud, Christian

    2007-01-01

    Recent trials suggest that off-pump coronary artery bypass grafting (OPCAB) reduces the risk of mortality and morbidity compared with conventional coronary artery bypass grafting (CCAB) using cardiopulmonary bypass. Patients with a moderate- to high-risk of complications after CCAB may have addit...

  16. Partial Ileal Bypass Undone

    NARCIS (Netherlands)

    Beynen, A.C.; Schouten, J.A.; Hoitsma, H.F.W.

    1984-01-01

    Partial ileal bypass (PIB) for the treatment of hypercholesterolaemia was introduced 20 years ago. About 110 cases have been described. We know of only 1 case of restoration of intestinal continuity; no details were given. We report here the second case of PIB in the Netherlands; the operation was r

  17. Aortic valve bypass

    DEFF Research Database (Denmark)

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik;

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI...

  18. Experimental laparoscopic aortobifemoral bypass.

    Science.gov (United States)

    Dion, Y M; Chin, A K; Thompson, T A

    1995-08-01

    The goal of the present study is to develop a technique for laparoscopic aortobifemoral bypass. Piglets weighing between 60 and 78 kg were anesthetized with halothane. The lateral retroperitoneal approach was preferred to the more familiar anterior transperitoneal approach and was successfully completed in 19 piglets. The piglets were placed in the right lateral decubitus position. The first port (2 cm) was inserted halfway between the tip of the 12th rib and the iliac crest. Four other trocars were placed in the retroperitoneum after balloon inflation had allowed creation of a space which permitted visualization of the aorta from the left renal artery down to the aorto-iliac junction. After evacuation of the retropneumoperitoneum, the cavity was maintained using an abdominal lift device and a retractor. Using this approach, we performed four aorto-bifemoral bypasses (end-to-end aortic anastomosis) after conventional intravenous heparinization (100 IU/kg) in less than 4 h. Blood loss did not exceed 250 ml and the hematocrit remained stable. Postmortem evaluation of the grafts revealed they were positioned as in a conventional bypass, their limbs having followed in the created retroperitoneal tunnels along the path of the native arteries. No mortality occurred before sacrifice of the animals. We believe that this first performed series of totally retroperitoneal laparoscopic aortobifemoral bypasses in the porcine model is useful in preparation for human application due to the anatomical similarities in the periaortic region.

  19. Lysosomal Storage Disorders and Malignancy

    Directory of Open Access Journals (Sweden)

    Gregory M. Pastores

    2017-02-01

    Full Text Available Lysosomal storage disorders (LSDs are infrequent to rare conditions caused by mutations that lead to a disruption in the usual sequential degradation of macromolecules or their transit within the cell. Gaucher disease (GD, a lipidosis, is among the most common LSD, with an estimated incidence of 1 in 40,000 among the Caucasian, non-Jewish population. Studies have indicated an increased frequency of polyclonal and monoclonal gammopathy among patients with GD. It has been shown that two major sphingolipids that accumulate in GD, namely, β-glucosylceramide 22:0 (βGL1-22 and glucosylsphingosine (LGL1, can be recognized by a distinct subset of CD1d-restricted human and murine type II natural killer T (NKT cells. Investigations undertaken in an affected mouse model revealed βGL1-22- and LGL1-specific NKT cells were present and constitutively promoted the expression of a T-follicular helper (TFH phenotype; injection of these lipids led to downstream induction of germinal center B cells, hypergammaglobulinemia, and the production of antilipid antibodies. Subsequent studies have found clonal immunoglobulin in 33% of sporadic human monoclonal gammopathies is also specific for the lysolipids LGL1 and lysophosphatidylcholine (LPC. Furthermore, substrate reduction ameliorated GD-associated gammopathy in mice. It had been hypothesized that chronic antigenic stimulation by the abnormal lipid storage and associated immune dysregulation may be the underlying mechanism for the increased incidence of monoclonal and polyclonal gammopathies, as well as an increased incidence of multiple myeloma in patients with GD. Current observations support this proposition and illustrate the value of investigations into rare diseases, which as ‘experiments of nature’ may provide insights into conditions found in the general population that continue to remain incompletely understood.

  20. Hsp70 stabilizes lysosomes and reverts Niemann-Pick disease-associated lysosomal pathology

    DEFF Research Database (Denmark)

    Kirkegaard, Thomas; Roth, Anke G; Petersen, Nikolaj H T

    2010-01-01

    inhibition of ASM, effectively revert the Hsp70-mediated stabilization of lysosomes. Notably, the reduced ASM activity in cells from patients with Niemann-Pick disease (NPD) A and B-severe lysosomal storage disorders caused by mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1) encoding for ASM...

  1. Mice doubly-deficient in lysosomal hexosaminidase A and neuraminidase 4 show epileptic crises and rapid neuronal loss.

    Science.gov (United States)

    Seyrantepe, Volkan; Lema, Pablo; Caqueret, Aurore; Dridi, Larbi; Bel Hadj, Samar; Carpentier, Stephane; Boucher, Francine; Levade, Thierry; Carmant, Lionel; Gravel, Roy A; Hamel, Edith; Vachon, Pascal; Di Cristo, Graziella; Michaud, Jacques L; Morales, Carlos R; Pshezhetsky, Alexey V

    2010-09-16

    Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the α-subunit of lysosomal β-hexosaminidase A, which converts G(M2) to G(M3) ganglioside. Hexa(-/-) mice, depleted of β-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise G(M2) ganglioside via a lysosomal sialidase into glycolipid G(A2), which is further processed by β-hexosaminidase B to lactosyl-ceramide, thereby bypassing the β-hexosaminidase A defect. Since this bypass is not effective in humans, infantile Tay-Sachs disease is fatal in the first years of life. Previously, we identified a novel ganglioside metabolizing sialidase, Neu4, abundantly expressed in mouse brain neurons. Now we demonstrate that mice with targeted disruption of both Neu4 and Hexa genes (Neu4(-/-);Hexa(-/-)) show epileptic seizures with 40% penetrance correlating with polyspike discharges on the cortical electrodes of the electroencephalogram. Single knockout Hexa(-/-) or Neu4(-/-) siblings do not show such symptoms. Further, double-knockout but not single-knockout mice have multiple degenerating neurons in the cortex and hippocampus and multiple layers of cortical neurons accumulating G(M2) ganglioside. Together, our data suggest that the Neu4 block exacerbates the disease in Hexa(-/-) mice, indicating that Neu4 is a modifier gene in the mouse model of Tay-Sachs disease, reducing the disease severity through the metabolic bypass. However, while disease severity in the double mutant is increased, it is not profound suggesting that Neu4 is not the only sialidase contributing to the metabolic bypass in Hexa(-/-) mice.

  2. Mice doubly-deficient in lysosomal hexosaminidase A and neuraminidase 4 show epileptic crises and rapid neuronal loss.

    Directory of Open Access Journals (Sweden)

    Volkan Seyrantepe

    2010-09-01

    Full Text Available Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the α-subunit of lysosomal β-hexosaminidase A, which converts G(M2 to G(M3 ganglioside. Hexa(-/- mice, depleted of β-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise G(M2 ganglioside via a lysosomal sialidase into glycolipid G(A2, which is further processed by β-hexosaminidase B to lactosyl-ceramide, thereby bypassing the β-hexosaminidase A defect. Since this bypass is not effective in humans, infantile Tay-Sachs disease is fatal in the first years of life. Previously, we identified a novel ganglioside metabolizing sialidase, Neu4, abundantly expressed in mouse brain neurons. Now we demonstrate that mice with targeted disruption of both Neu4 and Hexa genes (Neu4(-/-;Hexa(-/- show epileptic seizures with 40% penetrance correlating with polyspike discharges on the cortical electrodes of the electroencephalogram. Single knockout Hexa(-/- or Neu4(-/- siblings do not show such symptoms. Further, double-knockout but not single-knockout mice have multiple degenerating neurons in the cortex and hippocampus and multiple layers of cortical neurons accumulating G(M2 ganglioside. Together, our data suggest that the Neu4 block exacerbates the disease in Hexa(-/- mice, indicating that Neu4 is a modifier gene in the mouse model of Tay-Sachs disease, reducing the disease severity through the metabolic bypass. However, while disease severity in the double mutant is increased, it is not profound suggesting that Neu4 is not the only sialidase contributing to the metabolic bypass in Hexa(-/- mice.

  3. Mitochondrial Dysfunction in Lysosomal Storage Disorders

    Directory of Open Access Journals (Sweden)

    Mario de la Mata

    2016-10-01

    Full Text Available Lysosomal storage diseases (LSDs describe a heterogeneous group of rare inherited metabolic disorders that result from the absence or loss of function of lysosomal hydrolases or transporters, resulting in the progressive accumulation of undigested material in lysosomes. The accumulation of substances affects the function of lysosomes and other organelles, resulting in secondary alterations such as impairment of autophagy, mitochondrial dysfunction, inflammation and apoptosis. LSDs frequently involve the central nervous system (CNS, where neuronal dysfunction or loss results in progressive neurodegeneration and premature death. Many LSDs exhibit signs of mitochondrial dysfunction, which include mitochondrial morphological changes, decreased mitochondrial membrane potential (ΔΨm, diminished ATP production and increased generation of reactive oxygen species (ROS. Furthermore, reduced autophagic flux may lead to the persistence of dysfunctional mitochondria. Gaucher disease (GD, the LSD with the highest prevalence, is caused by mutations in the GBA1 gene that results in defective and insufficient activity of the enzyme β-glucocerebrosidase (GCase. Decreased catalytic activity and/or instability of GCase leads to accumulation of glucosylceramide (GlcCer and glucosylsphingosine (GlcSph in the lysosomes of macrophage cells and visceral organs. Mitochondrial dysfunction has been reported to occur in numerous cellular and mouse models of GD. The aim of this manuscript is to review the current knowledge and implications of mitochondrial dysfunction in LSDs.

  4. Relationship of femorodistal bypass patency to clinical outcome. Iloprost Bypass International Study Group

    DEFF Research Database (Denmark)

    Watson, H R; Schroeder, T V; Simms, M H;

    1999-01-01

    To investigate the relationship between bypass patency, limb survival and clinical symptoms after femorodistal bypass procedures.......To investigate the relationship between bypass patency, limb survival and clinical symptoms after femorodistal bypass procedures....

  5. Endo-lysosomal dysfunction in human proximal tubular epithelial cells deficient for lysosomal cystine transporter cystinosin.

    Directory of Open Access Journals (Sweden)

    Ekaterina A Ivanova

    Full Text Available Nephropathic cystinosis is a lysosomal storage disorder caused by mutations in the CTNS gene encoding cystine transporter cystinosin that results in accumulation of amino acid cystine in the lysosomes throughout the body and especially affects kidneys. Early manifestations of the disease include renal Fanconi syndrome, a generalized proximal tubular dysfunction. Current therapy of cystinosis is based on cystine-lowering drug cysteamine that postpones the disease progression but offers no cure for the Fanconi syndrome. We studied the mechanisms of impaired reabsorption in human proximal tubular epithelial cells (PTEC deficient for cystinosin and investigated the endo-lysosomal compartments of cystinosin-deficient PTEC by means of light and electron microscopy. We demonstrate that cystinosin-deficient cells had abnormal shape and distribution of the endo-lysosomal compartments and impaired endocytosis, with decreased surface expression of multiligand receptors and delayed lysosomal cargo processing. Treatment with cysteamine improved surface expression and lysosomal cargo processing but did not lead to a complete restoration and had no effect on the abnormal morphology of endo-lysosomal compartments. The obtained results improve our understanding of the mechanism of proximal tubular dysfunction in cystinosis and indicate that impaired protein reabsorption can, at least partially, be explained by abnormal trafficking of endosomal vesicles.

  6. Lysosomal Ca(2+) homeostasis: role in pathogenesis of lysosomal storage diseases.

    Science.gov (United States)

    Lloyd-Evans, Emyr; Platt, Frances M

    2011-08-01

    Disrupted cellular Ca(2+) signaling is believed to play a role in a number of human diseases including lysosomal storage diseases (LSD). LSDs are a group of ∼50 diseases caused predominantly by mutations in lysosomal proteins that result in accumulation of macromolecules within the lysosome. We recently reported that Niemann-Pick type C (NPC) is the first human disease to be associated with defective lysosomal Ca(2+) uptake and defective NAADP-mediated lysosomal Ca(2+) release. These defects in NPC cells leads to the disruption in endocytosis and subsequent lipid storage that is a feature of this disease. In contrast, Chediak-Higashi Syndrome cells have been reported to have enhanced lysosomal Ca(2+) uptake whilst the TRPML1 protein defective in mucolipidosis type IV is believed to function as a Ca(2+) channel. In this review we provide a summary of the current knowledge on the role of lysosomal Ca(2+) signaling in the pathogenesis of this group of diseases.

  7. Lysosomal stress: a new player in perturbed lipid metabolism

    NARCIS (Netherlands)

    Gabriel, T.L.

    2017-01-01

    Lysosomes are involved in many different essential cellular processes, among others organelle and molecule degradation, exocytosis, cell energy metabolism, cholesterol and sphingolipid level regulation. Lysosomal stress has a strong impact on the immune system, affecting specially macrophages as the

  8. Activation of lysosomal function in the course of autophagy via mTORC1 suppression and autophagosome-lysosome fusion

    Institute of Scientific and Technical Information of China (English)

    Jing Zhou; Shi-Hao Tan; Valérie Nicolas; Chantal Bauvy; Nai-Di Yang; Jianbin Zhang; Yuan Xue

    2013-01-01

    Lysosome is a key subcellular organelle in the execution of the autophagic process and at present little is known whether lysosomal function is controlled in the process of autophagy.In this study,we first found that suppression of mammalian target of rapamycin (mTOR) activity by starvation or two mTOR catalytic inhibitors (PP242 and Torinl),but not by an allosteric inhibitor (rapamycin),leads to activation of lysosomal function.Second,we provided evidence that activation of lysosomal function is associated with the suppression of mTOR complex 1 (mTORC1),but not mTORC2,and the mTORC1 localization to lysosomes is not directly correlated to its regulatory role in lysosomal function.Third,we examined the involvement of transcription factor EB (TFEB) and demonstrated that TFEB activation following mTORC1 suppression is necessary but not sufficient for lysosomal activation.Finally,Atg5 or Atg7deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation,suggesting that lysosomal activation occurring in the course of autophagy is dependent on antophagosome-lysosome fusion.Taken together,this study demonstrates that in the course of autophagy,lysosomal function is upregulated via a dual mechanism involving mTORC1 suppression and autophagosome-lysosome fusion.

  9. Activation of lysosomal function in the course of autophagy via mTORC1 suppression and autophagosome-lysosome fusion.

    Science.gov (United States)

    Zhou, Jing; Tan, Shi-Hao; Nicolas, Valérie; Bauvy, Chantal; Yang, Nai-Di; Zhang, Jianbin; Xue, Yuan; Codogno, Patrice; Shen, Han-Ming

    2013-04-01

    Lysosome is a key subcellular organelle in the execution of the autophagic process and at present little is known whether lysosomal function is controlled in the process of autophagy. In this study, we first found that suppression of mammalian target of rapamycin (mTOR) activity by starvation or two mTOR catalytic inhibitors (PP242 and Torin1), but not by an allosteric inhibitor (rapamycin), leads to activation of lysosomal function. Second, we provided evidence that activation of lysosomal function is associated with the suppression of mTOR complex 1 (mTORC1), but not mTORC2, and the mTORC1 localization to lysosomes is not directly correlated to its regulatory role in lysosomal function. Third, we examined the involvement of transcription factor EB (TFEB) and demonstrated that TFEB activation following mTORC1 suppression is necessary but not sufficient for lysosomal activation. Finally, Atg5 or Atg7 deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation, suggesting that lysosomal activation occurring in the course of autophagy is dependent on autophagosome-lysosome fusion. Taken together, this study demonstrates that in the course of autophagy, lysosomal function is upregulated via a dual mechanism involving mTORC1 suppression and autophagosome-lysosome fusion.

  10. Coronary Artery Bypass

    Directory of Open Access Journals (Sweden)

    Kadri Ceberut

    2011-01-01

    Full Text Available Ancient schwannoma is a rare variant of neural tumors though rarely seen in the thorax. The combination with coronary artery diseases is also rare. Here we describe a 66 year-old male who had undergone one-stage combined surgery for thoracic ancient schwannomas removal and coronary artery disease. The masses were, respectively, 13 cm in the middle mediastinum and 5 cm in diameter originating from the intercostal nerve. The tumors were successfully removed using sternotomy, and then a coronary artery bypass grafting was performed. Here we discuss this rare tumor in relation to the relevant literature.

  11. Effects of ethanol, acetaldehyde and cholesteryl esters on pancreatic lysosomes.

    OpenAIRE

    Wilson, J S; Apte, M V; Thomas, M. C.; Haber, P S; Pirola, R C

    1992-01-01

    Recent studies indicate that altered lysosomal function may be involved in the early stages of pancreatic injury. Chronic consumption of ethanol increases rat pancreatic lysosomal fragility. The aim of this study is to determine whether the lysosomal fragility observed after chronic ethanol consumption is mediated by ethanol per se, its oxidative metabolite acetaldehyde or cholesteryl esters (substances which accumulate in the pancreas after ethanol consumption). Pancreatic lysosomes from cho...

  12. Mucolipidosis type IV protein TRPML1-dependent lysosome formation.

    Science.gov (United States)

    Miller, Austin; Schafer, Jessica; Upchurch, Cameron; Spooner, Ellen; Huynh, Julie; Hernandez, Sebastian; McLaughlin, Brooke; Oden, Liam; Fares, Hanna

    2015-03-01

    Lysosomes are dynamic organelles that undergo cycles of fusion and fission with themselves and with other organelles. Following fusion with late endosomes to form hybrid organelles, lysosomes are reformed as discrete organelles. This lysosome reformation or formation is a poorly understood process that has not been systematically analyzed and that lacks known regulators. In this study, we quantitatively define the multiple steps of lysosome formation and identify the first regulator of this process.

  13. Transport of Lysosome-Related Organelles

    NARCIS (Netherlands)

    Jordens, Ingrid

    2005-01-01

    Many intracellular compartments, including (MHC class II-containing) lysosomes, melanosomes and phagosomes, move along microtubules in a bi-directional manner due to the alternating activities of the plus-end directed kinesin motor and the minus-end directed dynein-dynactin motor. However, it is lar

  14. Lysosomal proteolysis: effects of aging and insulin.

    Science.gov (United States)

    Gromakova, I A; Konovalenko, O A

    2003-07-01

    Age-related characteristics of the effect of insulin on the activity of lysosomal proteolytic enzymes were studied. The relationship between the insulin effect on protein degradation and insulin degradation was analyzed. The effect of insulin on the activities of lysosomal enzymes was opposite in young and old rats (inhibitory in 3-month-old and stimulatory in 24-month-old animals). The activities of proteolytic enzymes were regulated by insulin in a glucose-independent manner: similar hypoglycemic effects of insulin in animals of different ages were accompanied by opposite changes in the activities of lysosomal enzymes. The inhibition of lysosomal enzymes by insulin in 3-month-old rats is consistent with a notion on the inhibitory effect of insulin on protein degradation. An opposite insulin effect in 24-month-old rats (i.e., stimulation of proteolytic activity by insulin) may be partly associated with attenuation of the degradation of insulin, resulting in disturbances in signaling that mediates the regulatory effects of insulin on protein degradation.

  15. TRPML: transporters of metals in lysosomes essential for cell survival?

    Science.gov (United States)

    Kiselyov, Kirill; Colletti, Grace A; Terwilliger, Austen; Ketchum, Kathleen; Lyons, Christopher W P; Quinn, James; Muallem, Shmuel

    2011-09-01

    Key aspects of lysosomal function are affected by the ionic content of the lysosomal lumen and, therefore, by the ion permeability in the lysosomal membrane. Such functions include regulation of lysosomal acidification, a critical process in delivery and activation of the lysosomal enzymes, release of metals from lysosomes into the cytoplasm and the Ca(2+)-dependent component of membrane fusion events in the endocytic pathway. While the basic mechanisms of lysosomal acidification have been largely defined, the lysosomal metal transport system is not well understood. TRPML1 is a lysosomal ion channel whose malfunction is implicated in the lysosomal storage disease Mucolipidosis Type IV. Recent evidence suggests that TRPML1 is involved in Fe(2+), Ca(2+) and Zn(2+) transport across the lysosomal membrane, ascribing novel physiological roles to this ion channel, and perhaps to its relatives TRPML2 and TRPML3 and illuminating poorly understood aspects of lysosomal function. Further, alterations in metal transport by the TRPMLs due to mutations or environmental factors may contribute to their role in the disease phenotype and cell death.

  16. A non-conserved miRNA regulates lysosomal function and impacts on a human lysosomal storage disorder

    DEFF Research Database (Denmark)

    Frankel, Lisa B; Di Malta, Chiara; Wen, Jiayu;

    2014-01-01

    Sulfatases are key enzymatic regulators of sulfate homeostasis with several biological functions including degradation of glycosaminoglycans (GAGs) and other macromolecules in lysosomes. In a severe lysosomal storage disorder, multiple sulfatase deficiency (MSD), global sulfatase activity is defi...

  17. Reactivation of Lysosomal Ca2+ Efflux Rescues Abnormal Lysosomal Storage in FIG4-Deficient Cells.

    Science.gov (United States)

    Zou, Jianlong; Hu, Bo; Arpag, Sezgi; Yan, Qing; Hamilton, Audra; Zeng, Yuan-Shan; Vanoye, Carlos G; Li, Jun

    2015-04-29

    Loss of function of FIG4 leads to Charcot-Marie-Tooth disease Type 4J, Yunis-Varon syndrome, or an epilepsy syndrome. FIG4 is a phosphatase with its catalytic specificity toward 5'-phosphate of phosphatidylinositol-3,5-diphosphate (PI3,5P2). However, the loss of FIG4 decreases PI3,5P2 levels likely due to FIG4's dominant effect in scaffolding a PI3,5P2 synthetic protein complex. At the cellular level, all these diseases share similar pathology with abnormal lysosomal storage and neuronal degeneration. Mice with no FIG4 expression (Fig4(-/-)) recapitulate the pathology in humans with FIG4 deficiency. Using a flow cytometry technique that rapidly quantifies lysosome sizes, we detected an impaired lysosomal fission, but normal fusion, in Fig4(-/-) cells. The fission defect was associated with a robust increase of intralysosomal Ca(2+) in Fig4(-/-) cells, including FIG4-deficient neurons. This finding was consistent with a suppressed Ca(2+) efflux of lysosomes because the endogenous ligand of lysosomal Ca(2+) channel TRPML1 is PI3,5P2 that is deficient in Fig4(-/-) cells. We reactivated the TRPML1 channels by application of TRPML1 synthetic ligand, ML-SA1. This treatment reduced the intralysosomal Ca(2+) level and rescued abnormal lysosomal storage in Fig4(-/-) culture cells and ex vivo DRGs. Furthermore, we found that the suppressed Ca(2+) efflux in Fig4(-/-) culture cells and Fig4(-/-) mouse brains profoundly downregulated the expression/activity of dynamin-1, a GTPase known to scissor organelle membranes during fission. This downregulation made dynamin-1 unavailable for lysosomal fission. Together, our study revealed a novel mechanism explaining abnormal lysosomal storage in FIG4 deficiency. Synthetic ligands of the TRPML1 may become a potential therapy against diseases with FIG4 deficiency.

  18. Neuroinflammatory paradigms in lysosomal storage diseases

    Directory of Open Access Journals (Sweden)

    Megan Elizabeth Bosch

    2015-10-01

    Full Text Available Lysosomal storage diseases (LSDs include approximately 70 distinct disorders that collectively account for 14% of all inherited metabolic diseases. LSDs are caused by mutations in various enzymes/proteins that disrupt lysosomal function, which impairs macromolecule degradation following endosome-lysosome and phagosome-lysosome fusion and autophagy, ultimately disrupting cellular homeostasis. LSDs are pathologically typified by lysosomal inclusions composed of a heterogeneous mixture of various proteins and lipids that can be found throughout the body. However, in many cases the CNS is dramatically affected, which may result from heightened neuronal vulnerability based on their post-mitotic state. Besides intrinsic neuronal defects, another emerging factor common to many LSDs is neuroinflammation, which may negatively impact neuronal survival and contribute to neurodegeneration. Microglial and astrocyte activation is a hallmark of many LSDs that affect the CNS, which often precedes and predicts regions where eventual neuron loss will occur. However, the timing, intensity, and duration of neuroinflammation may ultimately dictate the impact on CNS homeostasis. For example, a transient inflammatory response following CNS insult/injury can be neuroprotective, as glial cells attempt to remove the insult and provide trophic support to neurons. However, chronic inflammation, as seen in several LSDs, can promote neurodegeneration by creating a neurotoxic environment due to elevated levels of cytokines, chemokines, and pro-apoptotic molecules. Although neuroinflammation has been reported in several LSDs, the cellular basis and mechanisms responsible for eliciting neuroinflammatory pathways are just beginning to be defined. This review highlights the role of neuroinflammation in select LSDs and its potential contribution to neuron loss.

  19. Spiritual Bypass: A Preliminary Investigation

    Science.gov (United States)

    Cashwell, Craig S.; Glosoff, Harriet L.; Hammond, Cheree

    2010-01-01

    The phenomenon of spiritual bypass has received limited attention in the transpersonal psychology and counseling literature and has not been subjected to empirical inquiry. This study examines the phenomenon of spiritual bypass by considering how spirituality, mindfulness, alexithymia (emotional restrictiveness), and narcissism work together to…

  20. Cardiopulmonary bypass in pregnancy

    Directory of Open Access Journals (Sweden)

    Mukul Chandra Kapoor

    2014-01-01

    Full Text Available Cardiac surgery carried out on cardiopulmonary bypass (CPB in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women. Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB. The CPB is associated with utero-placental hypoperfusion due to a number of factors, which may translate into low fetal cardiac output, hypoxia and even death. Better maternal and fetal outcomes may be achieved by early pre-operative optimization of maternal cardiovascular status, use of perioperative fetal monitoring, optimization of CPB, delivery of a viable fetus before the operation and scheduling cardiac surgery on an elective basis during the second trimester.

  1. Biphasic regulation of lysosomal exocytosis by oxidative stress.

    Science.gov (United States)

    Ravi, Sreeram; Peña, Karina A; Chu, Charleen T; Kiselyov, Kirill

    2016-11-01

    Oxidative stress drives cell death in a number of diseases including ischemic stroke and neurodegenerative diseases. A better understanding of how cells recover from oxidative stress is likely to lead to better treatments for stroke and other diseases. The recent evidence obtained in several models ties the process of lysosomal exocytosis to the clearance of protein aggregates and toxic metals. The mechanisms that regulate lysosomal exocytosis, under normal or pathological conditions, are only beginning to emerge. Here we provide evidence for the biphasic effect of oxidative stress on lysosomal exocytosis. Lysosomal exocytosis was measured using the extracellular levels of the lysosomal enzyme beta-hexosaminidase (ß-hex). Low levels or oxidative stress stimulated lysosomal exocytosis, but inhibited it at high levels. Deletion of the lysosomal ion channel TRPML1 eliminated the stimulatory effect of low levels of oxidative stress. The inhibitory effects of oxidative stress appear to target the component of lysosomal exocytosis that is driven by extracellular Ca(2+). We propose that while moderate oxidative stress promotes cellular repair by stimulating lysosomal exocytosis, at high levels oxidative stress has a dual pathological effect: it directly causes cell damage and impairs damage repair by inhibiting lysosomal exocytosis. Harnessing these adaptive mechanisms may point to pharmacological interventions for diseases involving oxidative proteotoxicity or metal toxicity.

  2. Regulation of lysosomal ion homeostasis by channels and transporters.

    Science.gov (United States)

    Xiong, Jian; Zhu, Michael X

    2016-08-01

    Lysosomes are the major organelles that carry out degradation functions. They integrate and digest materials compartmentalized by endocytosis, phagocytosis or autophagy. In addition to more than 60 hydrolases residing in the lysosomes, there are also ion channels and transporters that mediate the flux or transport of H(+), Ca(2+), Na(+), K(+), and Cl(-) across the lysosomal membranes. Defects in ionic exchange can lead to abnormal lysosome morphology, defective vesicle trafficking, impaired autophagy, and diseases such as neurodegeneration and lysosomal storage disorders. The latter are characterized by incomplete lysosomal digestion and accumulation of toxic materials inside enlarged intracellular vacuoles. In addition to degradation, recent studies have revealed the roles of lysosomes in metabolic pathways through kinases such as mechanistic target of rapamycin (mTOR) and transcriptional regulation through calcium signaling molecules such as transcription factor EB (TFEB) and calcineurin. Owing to the development of new approaches including genetically encoded fluorescence probes and whole endolysosomal patch clamp recording techniques, studies on lysosomal ion channels have made remarkable progress in recent years. In this review, we will focus on the current knowledge of lysosome-resident ion channels and transporters, discuss their roles in maintaining lysosomal function, and evaluate how their dysfunction can result in disease.

  3. BAX channel activity mediates lysosomal disruption linked to Parkinson disease.

    Science.gov (United States)

    Bové, Jordi; Martínez-Vicente, Marta; Dehay, Benjamin; Perier, Celine; Recasens, Ariadna; Bombrun, Agnes; Antonsson, Bruno; Vila, Miquel

    2014-05-01

    Lysosomal disruption is increasingly regarded as a major pathogenic event in Parkinson disease (PD). A reduced number of intraneuronal lysosomes, decreased levels of lysosomal-associated proteins and accumulation of undegraded autophagosomes (AP) are observed in PD-derived samples, including fibroblasts, induced pluripotent stem cell-derived dopaminergic neurons, and post-mortem brain tissue. Mechanistic studies in toxic and genetic rodent PD models attribute PD-related lysosomal breakdown to abnormal lysosomal membrane permeabilization (LMP). However, the molecular mechanisms underlying PD-linked LMP and subsequent lysosomal defects remain virtually unknown, thereby precluding their potential therapeutic targeting. Here we show that the pro-apoptotic protein BAX (BCL2-associated X protein), which permeabilizes mitochondrial membranes in PD models and is activated in PD patients, translocates and internalizes into lysosomal membranes early following treatment with the parkinsonian neurotoxin MPTP, both in vitro and in vivo, within a time-frame correlating with LMP, lysosomal disruption, and autophagosome accumulation and preceding mitochondrial permeabilization and dopaminergic neurodegeneration. Supporting a direct permeabilizing effect of BAX on lysosomal membranes, recombinant BAX is able to induce LMP in purified mouse brain lysosomes and the latter can be prevented by pharmacological blockade of BAX channel activity. Furthermore, pharmacological BAX channel inhibition is able to prevent LMP, restore lysosomal levels, reverse AP accumulation, and attenuate mitochondrial permeabilization and overall nigrostriatal degeneration caused by MPTP, both in vitro and in vivo. Overall, our results reveal that PD-linked lysosomal impairment relies on BAX-induced LMP, and point to small molecules able to block BAX channel activity as potentially beneficial to attenuate both lysosomal defects and neurodegeneration occurring in PD.

  4. A potentially dynamic lysosomal role for the endogenous TRPML proteins.

    Science.gov (United States)

    Zeevi, David A; Frumkin, Ayala; Offen-Glasner, Vered; Kogot-Levin, Aviram; Bach, Gideon

    2009-10-01

    Lysosomal storage disorders (LSDs) constitute a diverse group of inherited diseases that result from lysosomal storage of compounds occurring in direct consequence to deficiencies of proteins implicated in proper lysosomal function. Pathology in the LSD mucolipidosis type IV (MLIV), is characterized by lysosomal storage of lipids together with water-soluble materials in cells from every tissue and organ of affected patients. Mutations in the mucolipin 1 (TRPML1) protein cause MLIV and TRPML1 has also been shown to interact with two of its paralogous proteins, mucolipin 2 (TRPML2) and mucolipin 3 (TRPML3), in heterologous expression systems. Heterogeneous lysosomal storage is readily identified in electron micrographs of MLIV patient cells, suggesting that proper TRPML1 function is essential for the maintenance of lysosomal integrity. In order to investigate whether TRPML2 and TRPML3 also play a role in the maintenance of lysosomal integrity, we conducted gene-specific knockdown assays against these protein targets. Ultrastructural analysis revealed lysosomal inclusions in both TRPML2 and TRPML3 knockdown cells, suggestive of a common mechanism for these proteins, in parallel with TRPML1, in the regulation of lysosomal integrity. However, co-immunoprecipitation assays revealed that physical interactions between each of the endogenous TRPML proteins are quite limited. In addition, we found that all three endogenous proteins only partially co-localize with each other in lysosomal as well as extra-lysosomal compartments. This suggests that native TRPML2 and TRPML3 might participate with native TRPML1 in a dynamic form of lysosomal regulation. Given that depletion of TRPML2/3 led to lysosomal storage typical to an LSD, we propose that depletion of these proteins might also underlie novel LSD pathologies not described hitherto.

  5. The late endosome/lysosome-anchored p18-mTORC1 pathway controls terminal maturation of lysosomes

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yusuke; Nada, Shigeyuki; Mori, Shunsuke; Soma-Nagae, Taeko; Oneyama, Chitose [Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Okada, Masato, E-mail: okadam@biken.osaka-u.ac.jp [Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer p18 is a membrane adaptor that anchors mTORC1 to late endosomes/lysosomes. Black-Right-Pointing-Pointer We examine the role of the p18-mTORC1 pathway in lysosome biogenesis. Black-Right-Pointing-Pointer The loss of p18 causes accumulation of intact late endosomes by arresting lysosome maturation. Black-Right-Pointing-Pointer Inhibition of mTORC1 activity with rapamycin phenocopies the defects of p18 loss. Black-Right-Pointing-Pointer The p18-mTORC1 pathway plays crucial roles in the terminal maturation of lysosomes. -- Abstract: The late endosome/lysosome membrane adaptor p18 (or LAMTOR1) serves as an anchor for the mammalian target of rapamycin complex 1 (mTORC1) and is required for its activation on lysosomes. The loss of p18 causes severe defects in cell growth as well as endosome dynamics, including membrane protein transport and lysosome biogenesis. However, the mechanisms underlying these effects on lysosome biogenesis remain unknown. Here, we show that the p18-mTORC1 pathway is crucial for terminal maturation of lysosomes. The loss of p18 causes aberrant intracellular distribution and abnormal sizes of late endosomes/lysosomes and an accumulation of late endosome specific components, including Rab7, RagC, and LAMP1; this suggests that intact late endosomes accumulate in the absence of p18. These defects are phenocopied by inhibiting mTORC1 activity with rapamycin. Loss of p18 also suppresses the integration of late endosomes and lysosomes, resulting in the defective degradation of tracer proteins. These results suggest that the p18-mTORC1 pathway plays crucial roles in the late stages of lysosomal maturation, potentially in late endosome-lysosome fusion, which is required for processing of various macromolecules.

  6. Quantitative modeling of selective lysosomal targeting for drug design

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rosania, G.; Horobin, R.W.;

    2008-01-01

    Lysosomes are acidic organelles and are involved in various diseases, the most prominent is malaria. Accumulation of molecules in the cell by diffusion from the external solution into cytosol, lysosome and mitochondrium was calculated with the Fick–Nernst–Planck equation. The cell model considers....... This demonstrates that the cell model can be a useful tool for the design of effective lysosome-targeting drugs with minimal off-target interactions....

  7. Release and uptake of lysosomal enzymes : studied in cultured cells

    OpenAIRE

    1980-01-01

    textabstractThe purpose of the experimental work described in this thesiswas to investigate some aspects of the release and uptake of lysosomal enzymes. The experiments involved the use of normal human and animal fibroblasts and some other cell types such as hepatocytes and hepatoma cells as sources of hydrolytic enzymes, and fibroblasts from patients with lysosomal storage diseases associated with a single lysosomal enzyme deficiency and with "1-cell" disease as recipient cells. In a number ...

  8. Factors and processes modulating phenotypes in neuronopathic lysosomal storage diseases

    OpenAIRE

    Jakóbkiewicz-Banecka, Joanna; Gabig-Cimińska, Magdalena; Banecka-Majkutewicz, Zyta; Banecki, Bogdan; Węgrzyn, Alicja; Węgrzyn, Grzegorz

    2013-01-01

    Lysosomal storage diseases are inherited metabolic disorders caused by genetic defects causing deficiency of various lysosomal proteins, and resultant accumulation of non-degraded compounds. They are multisystemic diseases, and in most of them (>70 %) severe brain dysfunctions are evident. However, expression of various phenotypes in particular diseases is extremely variable, from non-neuronopathic to severely neurodegenerative in the deficiency of the same enzyme. Although all lysosomal stor...

  9. Bypass rewiring and robustness of complex networks

    Science.gov (United States)

    Park, Junsang; Hahn, Sang Geun

    2016-08-01

    A concept of bypass rewiring is introduced, and random bypass rewiring is analytically and numerically investigated with simulations. Our results show that bypass rewiring makes networks robust against removal of nodes including random failures and attacks. In particular, random bypass rewiring connects all nodes except the removed nodes on an even degree infinite network and makes the percolation threshold 0 for arbitrary occupation probabilities. In our example, the even degree network is more robust than the original network with random bypass rewiring, while the original network is more robust than the even degree networks without random bypass. We propose a greedy bypass rewiring algorithm which guarantees the maximum size of the largest component at each step, assuming which node will be removed next is unknown. The simulation result shows that the greedy bypass rewiring algorithm improves the robustness of the autonomous system of the Internet under attacks more than random bypass rewiring.

  10. Bypass Rewiring and Robustness of Complex Networks

    CERN Document Server

    Park, Junsang

    2016-01-01

    A concept of bypass rewiring is introduced and random bypass rewiring is analytically and numerically investigated with simulations. Our results show that bypass rewiring makes networks robust against removal of nodes including random failures and attacks. Especially, random bypass rewiring connects all nodes except the removed nodes on an even degree infinite network and makes the percolation threshold $0$ for arbitrary occupation probabilities. In our example, the even degree network is more robust than the original network with random bypass rewiring while the original network is more robust than the even degree networks without random bypass. We propose a greedy bypass rewiring algorithm which guarantees the maximum size of the largest component at each step, assuming which node will be removed next is unknown. The simulation result shows that the greedy bypass rewiring algorithm improves the robustness of the autonomous system of the Internet under attacks more than random bypass rewiring.

  11. A lysosome-centered view of nutrient homeostasis.

    Science.gov (United States)

    Mony, Vinod K; Benjamin, Shawna; O'Rourke, Eyleen J

    2016-01-01

    Lysosomes are highly acidic cellular organelles traditionally viewed as sacs of enzymes involved in digesting extracellular or intracellular macromolecules for the regeneration of basic building blocks, cellular housekeeping, or pathogen degradation. Bound by a single lipid bilayer, lysosomes receive their substrates by fusing with endosomes or autophagosomes, or through specialized translocation mechanisms such as chaperone-mediated autophagy or microautophagy. Lysosomes degrade their substrates using up to 60 different soluble hydrolases and release their products either to the cytosol through poorly defined exporting and efflux mechanisms or to the extracellular space by fusing with the plasma membrane. However, it is becoming evident that the role of the lysosome in nutrient homeostasis goes beyond the disposal of waste or the recycling of building blocks. The lysosome is emerging as a signaling hub that can integrate and relay external and internal nutritional information to promote cellular and organismal homeostasis, as well as a major contributor to the processing of energy-dense molecules like glycogen and triglycerides. Here we describe the current knowledge of the nutrient signaling pathways governing lysosomal function, the role of the lysosome in nutrient mobilization, and how lysosomes signal other organelles, distant tissues, and even themselves to ensure energy homeostasis in spite of fluctuations in energy intake. At the same time, we highlight the value of genomics approaches to the past and future discoveries of how the lysosome simultaneously executes and controls cellular homeostasis.

  12. Lysosomal disruption preferentially targets acute myeloid leukemia cells and progenitors

    Science.gov (United States)

    Sukhai, Mahadeo A.; Prabha, Swayam; Hurren, Rose; Rutledge, Angela C.; Lee, Anna Y.; Sriskanthadevan, Shrivani; Sun, Hong; Wang, Xiaoming; Skrtic, Marko; Seneviratne, Ayesh; Cusimano, Maria; Jhas, Bozhena; Gronda, Marcela; MacLean, Neil; Cho, Eunice E.; Spagnuolo, Paul A.; Sharmeen, Sumaiya; Gebbia, Marinella; Urbanus, Malene; Eppert, Kolja; Dissanayake, Dilan; Jonet, Alexia; Dassonville-Klimpt, Alexandra; Li, Xiaoming; Datti, Alessandro; Ohashi, Pamela S.; Wrana, Jeff; Rogers, Ian; Sonnet, Pascal; Ellis, William Y.; Corey, Seth J.; Eaves, Connie; Minden, Mark D.; Wang, Jean C.Y.; Dick, John E.; Nislow, Corey; Giaever, Guri; Schimmer, Aaron D.

    2012-01-01

    Despite efforts to understand and treat acute myeloid leukemia (AML), there remains a need for more comprehensive therapies to prevent AML-associated relapses. To identify new therapeutic strategies for AML, we screened a library of on- and off-patent drugs and identified the antimalarial agent mefloquine as a compound that selectively kills AML cells and AML stem cells in a panel of leukemia cell lines and in mice. Using a yeast genome-wide functional screen for mefloquine sensitizers, we identified genes associated with the yeast vacuole, the homolog of the mammalian lysosome. Consistent with this, we determined that mefloquine disrupts lysosomes, directly permeabilizes the lysosome membrane, and releases cathepsins into the cytosol. Knockdown of the lysosomal membrane proteins LAMP1 and LAMP2 resulted in decreased cell viability, as did treatment of AML cells with known lysosome disrupters. Highlighting a potential therapeutic rationale for this strategy, leukemic cells had significantly larger lysosomes compared with normal cells, and leukemia-initiating cells overexpressed lysosomal biogenesis genes. These results demonstrate that lysosomal disruption preferentially targets AML cells and AML progenitor cells, providing a rationale for testing lysosomal disruption as a novel therapeutic strategy for AML. PMID:23202731

  13. Presenilin 1 Maintains Lysosomal Ca(2+) Homeostasis via TRPML1 by Regulating vATPase-Mediated Lysosome Acidification.

    Science.gov (United States)

    Lee, Ju-Hyun; McBrayer, Mary Kate; Wolfe, Devin M; Haslett, Luke J; Kumar, Asok; Sato, Yutaka; Lie, Pearl P Y; Mohan, Panaiyur; Coffey, Erin E; Kompella, Uday; Mitchell, Claire H; Lloyd-Evans, Emyr; Nixon, Ralph A

    2015-09-01

    Presenilin 1 (PS1) deletion or Alzheimer's disease (AD)-linked mutations disrupt lysosomal acidification and proteolysis, which inhibits autophagy. Here, we establish that this phenotype stems from impaired glycosylation and instability of vATPase V0a1 subunit, causing deficient lysosomal vATPase assembly and function. We further demonstrate that elevated lysosomal pH in Presenilin 1 knockout (PS1KO) cells induces abnormal Ca(2+) efflux from lysosomes mediated by TRPML1 and elevates cytosolic Ca(2+). In WT cells, blocking vATPase activity or knockdown of either PS1 or the V0a1 subunit of vATPase reproduces all of these abnormalities. Normalizing lysosomal pH in PS1KO cells using acidic nanoparticles restores normal lysosomal proteolysis, autophagy, and Ca(2+) homeostasis, but correcting lysosomal Ca(2+) deficits alone neither re-acidifies lysosomes nor reverses proteolytic and autophagic deficits. Our results indicate that vATPase deficiency in PS1 loss-of-function states causes lysosomal/autophagy deficits and contributes to abnormal cellular Ca(2+) homeostasis, thus linking two AD-related pathogenic processes through a common molecular mechanism.

  14. Presenilin 1 Maintains Lysosomal Ca2+ Homeostasis via TRPML1 by Regulating vATPase-Mediated Lysosome Acidification

    Directory of Open Access Journals (Sweden)

    Ju-Hyun Lee

    2015-09-01

    Full Text Available Presenilin 1 (PS1 deletion or Alzheimer’s disease (AD-linked mutations disrupt lysosomal acidification and proteolysis, which inhibits autophagy. Here, we establish that this phenotype stems from impaired glycosylation and instability of vATPase V0a1 subunit, causing deficient lysosomal vATPase assembly and function. We further demonstrate that elevated lysosomal pH in Presenilin 1 knockout (PS1KO cells induces abnormal Ca2+ efflux from lysosomes mediated by TRPML1 and elevates cytosolic Ca2+. In WT cells, blocking vATPase activity or knockdown of either PS1 or the V0a1 subunit of vATPase reproduces all of these abnormalities. Normalizing lysosomal pH in PS1KO cells using acidic nanoparticles restores normal lysosomal proteolysis, autophagy, and Ca2+ homeostasis, but correcting lysosomal Ca2+ deficits alone neither re-acidifies lysosomes nor reverses proteolytic and autophagic deficits. Our results indicate that vATPase deficiency in PS1 loss-of-function states causes lysosomal/autophagy deficits and contributes to abnormal cellular Ca2+ homeostasis, thus linking two AD-related pathogenic processes through a common molecular mechanism.

  15. Gaucher disease: a lysosomal neurodegenerative disorder.

    Science.gov (United States)

    Huang, W J; Zhang, X; Chen, W W

    2015-04-01

    Gaucher disease is a multisystemic disorder that affects men and woman in equal numbers and occurs in all ethnic groups at any age with racial variations and an estimated worldwide incidence of 1/75,000. It is caused by a genetic deficient activity of the lysosomal enzyme glucocerebrosidase due to mutations in the β-glucocerebrosidase gene, and resulting in lack of glucocerebroside degradation. The subsequent accumulation of glucocerebroside in lysosomes of tissue macrophages primarily in the liver, bone marrow and spleen, causes damage in haematological, skeletal and nervous systems. The clinical manifestations show a high degree of variability with symptoms that varies according to organs involved. In many cases, these disorders do not correlate with mutations in the β-glucocerebrosidase gene. Although several mutations have been identified as responsible for the deficient activity of glucocerebrosidase, mechanisms by which this enzymatic defect leads to Gaucher disease remain poorly understood. Recent reports indicate the implication of complex mechanisms, including enzyme deficiency, substrate accumulation, unfolded protein response, and macrophage activation. Further elucidating these mechanisms will advance understanding of Gaucher disease and related disorders.

  16. Enhanced lysosomal activity by overexpressed aminopeptidase Y in Saccharomyces cerevisiae.

    Science.gov (United States)

    Yoon, Jihee; Sekhon, Simranjeet Singh; Kim, Yang-Hoon; Min, Jiho

    2016-06-01

    Saccharomyces cerevisiae contains vacuoles corresponding to lysosomes in higher eukaryotes. Lysosomes are dynamic (not silent) organelles in which enzymes can be easily integrated or released when exposed to stressful conditions. Changes in lysosomal enzymes have been observed due to oxidative stress, resulting in an increased function of lysosomes. The protein profiles from H2O2- and NH4Cl-treated lysosomes showed different expression patterns, observed with two-dimensional gel electrophoresis. The aminopeptidase Y protein (APE3) that conspicuously enhanced antimicrobial activity than other proteins was selected for further studies. The S. cerevisiae APE3 gene was isolated and inserted into pYES2.0 expression vector. The GFP gene was inserted downstream to the APE3 gene for confirmation of APE3 targeting to lysosomes, and S. cerevisiae was transformed to pYES2::APE3::GFP. The APE3 did not enter in lysosomes and formed an inclusion body at 30 °C, but it inserted to lysosomes as shown by the merger of GFP with lysosomes at 28 °C. Antimicrobial activity of the cloned S. cerevisiae increased about 5 to 10 % against eight strains, compared to normal cells, and galactose induction is increased more two folds than that of normal cells. Therefore, S. cerevisiae was transformed to pYES2::APE3::GFP, accumulating a large amount of APE3, resulting in increased lysosomal activity. Increase in endogenous levels of lysosomes and their activity following genetic modification can lead to its use in applications such as antimicrobial agents and apoptosis-inducing materials for cancer cells, and consequently, it may also be possible to use the organelles for improving in vitro functions.

  17. [The blood-brain barrier and neurodegenerative lysosomal storage diseases].

    Science.gov (United States)

    Urayama, Akihiko

    2013-02-01

    Enzyme replacement therapy has been a very effective treatment for several lysosomal storage diseases. However, correcting central nervous system (CNS) storage has been challenging due to the presence of the blood-brain barrier (BBB), which hampers the entry of circulating lysosomal enzymes into the brain. In our previous studies, we discovered that luminally expressed cation-independent mannose 6-phosphate (M6P) receptor is a universal transporter for lysosomal enzymes that contain M6P moieties on the enzyme molecule. This receptor-mediated transport of lysosomal enzymes showed developmental down-regulation that resulted in a failure of delivery of lysosomal enzymes across the BBB in the adult brain. Conceptually, if one can re-induce M6P receptor-mediated transport of lysosomal enzymes in adult BBB, this could provide a novel brain targeting approach for treating abnormal storage in the CNS, regardless of the age of subjects. We found that systemic adrenergic stimuli restored functional transport of β-glucuronidase across the adult BBB. The concept of manipulating BBB transport activity by endogenous characteristics has also been demonstrated by another group who showed effective treatment in a Pompe disease model animal in vivo. It is intriguing that lysosomal enzymes utilize multiple mechanisms for their transport across the BBB. This review explores pharmacological manipulations for the delivery of lysosomal enzymes into the CNS, and the mechanisms of their transport across the BBB, based on existing evidence from studies of β-glucuronidase, sulfamidase, acid α-glucosidase, and arylsulfatase A.

  18. Photoaffinity labeling of the lysosomal neuraminidase from bovine testis

    NARCIS (Netherlands)

    G.T.J. van der Horst (Gijsbertus); U. Rose (Ursula); R. Brossmer (Reinhard); F.W. Verheijen (Frans)

    1990-01-01

    markdownabstractAbstract ASA-NeuAc2en, a photoreactive arylazide derivative of sialic acid, is shown to be a powerful competitive inhibitor of lysosomal neuraminidase from bovine testis (Ki ≈ 21 μM). Photoaffinity labeling and partial purification of preparations containing this lysosomal neuramin

  19. Lysosome/lipid droplet interplay in metabolic diseases.

    Science.gov (United States)

    Dugail, Isabelle

    2014-01-01

    Lysosomes and lipid droplets are generally considered as intracellular compartments with divergent roles in cell metabolism, lipid droplets serving as lipid reservoirs in anabolic pathways, whereas lysosomes are specialized in the catabolism of intracellular components. During the last few years, new insights in the biology of lysosomes has challenged this view by providing evidence for the importance of lysosome recycling as a sparing mechanism to maintain cellular fitness. On the other hand the understanding of lipid droplets has evolved from an inert intracellular deposit toward the status of an intracellular organelle with dynamic roles in cellular homeostasis beyond storage. These unrelated aspects have also recently converged in the finding of unexpected lipid droplet/lysosome communication through autophagy, and the discovery of lysosome-mediated lipid droplet degradation called lipopagy. Furthermore, adipocytes which are professional cells for lipid droplet formation were also shown to be active in peptide antigen presentation a pathway requiring lysosomal activity. The potential importance of lipid droplet/lysosome interplay is discussed in the context of metabolic diseases and the setting of chronic inflammation.

  20. Artesunate induces cell death in human cancer cells via enhancing lysosomal function and lysosomal degradation of ferritin.

    Science.gov (United States)

    Yang, Nai-Di; Tan, Shi-Hao; Ng, Shukie; Shi, Yin; Zhou, Jing; Tan, Kevin Shyong Wei; Wong, Wai-Shiu Fred; Shen, Han-Ming

    2014-11-28

    Artesunate (ART) is an anti-malaria drug that has been shown to exhibit anti-tumor activity, and functional lysosomes are reported to be required for ART-induced cancer cell death, whereas the underlying molecular mechanisms remain largely elusive. In this study, we aimed to elucidate the molecular mechanisms underlying ART-induced cell death. We first confirmed that ART induces apoptotic cell death in cancer cells. Interestingly, we found that ART preferably accumulates in the lysosomes and is able to activate lysosomal function via promotion of lysosomal V-ATPase assembly. Furthermore, we found that lysosomes function upstream of mitochondria in reactive oxygen species production. Importantly, we provided evidence showing that lysosomal iron is required for the lysosomal activation and mitochondrial reactive oxygen species production induced by ART. Finally, we showed that ART-induced cell death is mediated by the release of iron in the lysosomes, which results from the lysosomal degradation of ferritin, an iron storage protein. Meanwhile, overexpression of ferritin heavy chain significantly protected cells from ART-induced cell death. In addition, knockdown of nuclear receptor coactivator 4, the adaptor protein for ferritin degradation, was able to block ART-mediated ferritin degradation and rescue the ART-induced cell death. In summary, our study demonstrates that ART treatment activates lysosomal function and then promotes ferritin degradation, subsequently leading to the increase of lysosomal iron that is utilized by ART for its cytotoxic effect on cancer cells. Thus, our data reveal a new mechanistic action underlying ART-induced cell death in cancer cells.

  1. Heart bypass surgery - minimally invasive - discharge

    Science.gov (United States)

    ... invasive direct coronary artery bypass - discharge; MIDCAB - discharge; Robot assisted coronary artery bypass - discharge; RACAB - discharge; Keyhole ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  2. Current peripheral bypass surgery: various clinical studies

    NARCIS (Netherlands)

    Slaa, Alexander te

    2011-01-01

    Substantial post-operative edema occurs in the majority of patients who undergo peripheral bypass surgery due to severe peripheral arterial disease (PAD). The pathophysiological mechanisms that underlay edema formation following peripheral bypass surgery include hyperemia, an increased capillary per

  3. Technology Solutions Case Study: Preventing Thermal Bypass

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-10-01

    This project highlights the importance of continuous air barriers in full alignment with insulation to prevent thermal bypasses and achieve high energy performance, and recommends use of ENERGY STAR's Thermal Bypass Inspection Checklist.

  4. Perforation in the bypassed stomach following laparoscopic Roux-en-Y gastric bypass.

    Science.gov (United States)

    Papasavas, Pavlos K; Yeaney, Woodrow W; Caushaj, Philip F; Keenan, Robert J; Landreneau, Rodney J; Gagné, Daniel J

    2003-10-01

    Access to the bypassed stomach is difficult following laparoscopic Roux-en-Y gastric bypass (LRYGBP). The bypassed stomach is not readily available for endoscopic or radiographic evaluation. Diagnosis and treatment of peptic ulcer disease and its complications in the excluded stomach becomes difficult. We present a case of perforation in the bypassed stomach following LRYGBP secondary to peptic ulcer disease.

  5. Mitochondrial respiration controls lysosomal function during inflammatory T cell responses

    Science.gov (United States)

    Baixauli, Francesc; Acín-Pérez, Rebeca; Villarroya-Beltrí, Carolina; Mazzeo, Carla; Nuñez-Andrade, Norman; Gabandé-Rodriguez, Enrique; Dolores Ledesma, Maria; Blázquez, Alberto; Martin, Miguel Angel; Falcón-Pérez, Juan Manuel; Redondo, Juan Miguel; Enríquez, Jose Antonio; Mittelbrunn, Maria

    2016-01-01

    Summary The endolysosomal system is critical for the maintenance of cellular homeostasis. However, how endolysosomal compartment is regulated by mitochondrial function is largely unknown. We have generated a mouse model with defective mitochondrial function in CD4+ T lymphocytes by genetic deletion of the mitochondrial transcription factor A (Tfam). Mitochondrial respiration-deficiency impairs lysosome function, promotes p62 and sphingomyelin accumulation and disrupts endolysosomal trafficking pathways and autophagy, thus linking a primary mitochondrial dysfunction to a lysosomal storage disorder. The impaired lysosome function in Tfam-deficient cells subverts T cell differentiation toward pro-inflammatory subsets and exacerbates the in vivo inflammatory response. Restoration of NAD+ levels improves lysosome function and corrects the inflammatory defects in Tfam-deficient T cells. Our results uncover a mechanism by which mitochondria regulate lysosome function to preserve T cell differentiation and effector functions, and identify novel strategies for intervention in mitochondrial-related diseases. PMID:26299452

  6. 40 CFR 403.17 - Bypass.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Bypass. 403.17 Section 403.17... GENERAL PRE-TREAT-MENT REGULATIONS FOR EXIST-ING AND NEW SOURCES OF POLLUTION § 403.17 Bypass. (a) Definitions. (1) Bypass means the intentional diversion of wastestreams from any portion of an Industrial...

  7. Undiagnosed phaeochromocytoma following infrainguinal bypass surgery

    DEFF Research Database (Denmark)

    Levi, N; Schroeder, T V

    1998-01-01

    We present a rare case of undiagnosed phaeochromocytoma following infrainguinal bypass surgery. The patient, a 59-year-old lady, had a one year history of hypertension following a first femoro-tibial bypass and presented as a cardiorespiratory emergency in the admission room following her...... contralateral femoro-tibial bypass. The patient recovered after some days in intensive care despite a delayed diagnosis....

  8. Activation of peroxisome proliferator-activated receptor α induces lysosomal biogenesis in brain cells: implications for lysosomal storage disorders.

    Science.gov (United States)

    Ghosh, Arunava; Jana, Malabendu; Modi, Khushbu; Gonzalez, Frank J; Sims, Katherine B; Berry-Kravis, Elizabeth; Pahan, Kalipada

    2015-04-17

    Lysosomes are ubiquitous membrane-enclosed organelles filled with an acidic interior and are central to the autophagic, endocytic, or phagocytic pathway. In contrast to its classical function as the waste management machinery, lysosomes are now considered to be an integral part of various cellular signaling processes. The diverse functionality of this single organelle requires a very complex and coordinated regulation of its activity with transcription factor EB (TFEB), a master regulator of lysosomal biogenesis, at its core. However, mechanisms by which TFEB is regulated are poorly understood. This study demonstrates that gemfibrozil, an agonist of peroxisome proliferator-activated receptor (PPAR) α, alone and in conjunction with all-trans-retinoic acid is capable of enhancing TFEB in brain cells. We also observed that PPARα, but not PPARβ and PPARγ, is involved in gemfibrozil-mediated up-regulation of TFEB. Reporter assay and chromatin immunoprecipitation studies confirmed the recruitment of retinoid X receptor α, PPARα, and PGC1α on the PPAR-binding site on the Tfeb promoter as well. Subsequently, the drug-mediated induction of TFEB caused an increase in lysosomal protein and the lysosomal abundance in cell. Collectively, this study reinforces the link between lysosomal biogenesis and lipid metabolism with TFEB at the crossroads. Furthermore, gemfibrozil may be of therapeutic value in the treatment of lysosomal storage disorders in which autophagy-lysosome pathway plays an important role.

  9. In situ bypass og diabetes

    DEFF Research Database (Denmark)

    Jensen, Leif Panduro; Schroeder, T V; Lorentzen, J E

    1993-01-01

    From 1986 through to 1990 a total of 483 in situ bypass procedures were performed in 444 patients. Preoperative risk-factors were equally distributed among diabetic (DM) and non-diabetic (NDM) patients, except for smoking habits (DM:48%, NDM:64%, p = 0.002) and cardiac disease (DM:45%, NDM:29%, p...

  10. Deep-water sediment bypass

    NARCIS (Netherlands)

    Stevenson, Christopher J.; Jackson, Christopher A L; Hodgson, David M.; Hubbard, Stephen M.; Eggenhuisen, Joris T.

    2015-01-01

    Submarine gravity flows are a key process for transporting large volumes of sediment from the continents to the deep sea. The location, volume, and character of the sediment bypassed by these flows dictates the areal extent and thickness of the associated deposits. Despite its importance, sediment b

  11. Mucolipidosis type IV: the effect of increased lysosomal pH on the abnormal lysosomal storage.

    Science.gov (United States)

    Kogot-Levin, Aviram; Zeigler, Marsha; Ornoy, Asher; Bach, Gideon

    2009-06-01

    Mucolipidosis type IV (MLIV) is a neurodegenerative channelopathy that is caused by the deficiency of TRPML1 activity, a nonselective cation channel. TRPML1 is a lysosomal membrane protein, and thus, MLIV is a lysosomal storage disorder. The basic, specific function of TRPML1 has not been yet clarified. A recent report (Soyombo AA, Tjon-Kon-Sang S, Rbaibi Y, Bashllari E, Bisceglia J, Muallem S, Kiselyov K: J Biol Chem 281:7294-7301, 2006) indicated that TRPML1 functions as an outwardly proton channel whose function is the prevention of overacidification of these organelles. Thus, in MLIV the lysosomal pH is lower than normal. Furthermore, attempts by these investigators to increase slightly the lysososmal pH with either Nigericin or Chloroquine suggested corrective effect of the abnormal storage in MLIV cells. We investigated this approach using these agents with cultured fibroblasts from severely affected and milder patients. Our data indicated that there was no reduction in the total number of storage vesicles by either agent, although Nigericin resulted in a change in the nature of the storage materials, reducing the presence of lamellated substances (lipids) so that the storage vesicles contained predominantly granulated substances. On the other hand, transfection with the normal MCOLN1 cDNA (the gene coding for TRPML1) resulted in the removal of almost all the storage materials.

  12. Autophagy and lysosomal dysfunction as emerging mechanisms of nanomaterial toxicity

    Directory of Open Access Journals (Sweden)

    Stern Stephan T

    2012-06-01

    Full Text Available Abstract The study of the potential risks associated with the manufacture, use, and disposal of nanoscale materials, and their mechanisms of toxicity, is important for the continued advancement of nanotechnology. Currently, the most widely accepted paradigms of nanomaterial toxicity are oxidative stress and inflammation, but the underlying mechanisms are poorly defined. This review will highlight the significance of autophagy and lysosomal dysfunction as emerging mechanisms of nanomaterial toxicity. Most endocytic routes of nanomaterial cell uptake converge upon the lysosome, making the lysosomal compartment the most common intracellular site of nanoparticle sequestration and degradation. In addition to the endo-lysosomal pathway, recent evidence suggests that some nanomaterials can also induce autophagy. Among the many physiological functions, the lysosome, by way of the autophagy (macroautophagy pathway, degrades intracellular pathogens, and damaged organelles and proteins. Thus, autophagy induction by nanoparticles may be an attempt to degrade what is perceived by the cell as foreign or aberrant. While the autophagy and endo-lysosomal pathways have the potential to influence the disposition of nanomaterials, there is also a growing body of literature suggesting that biopersistent nanomaterials can, in turn, negatively impact these pathways. Indeed, there is ample evidence that biopersistent nanomaterials can cause autophagy and lysosomal dysfunctions resulting in toxicological consequences.

  13. Bypass materials in vascular surgery

    Science.gov (United States)

    Eidt, Daniela; Roll, Stephanie; Kulp, Werner; Müller-Nordhorn, Jaqueline; Vauth, Christoph; Greiner, Wolfgang; Willich, Stefan N.; von der Schulenburg, Johann-Matthias

    2006-01-01

    Introduction Arteriosclerotic changes can lead to circulatory disturbances in various areas of the human vascular system. In addition to pharmacological therapy and the management of risk factors (e. g. hypertension, diabetes, lipid metabolism disorders, and lifestyle), surgical interventions also play an important role in the treatment of arteriosclerosis. Long-segment arterial occlusions, in particular, can be treated successfully with bypass sur-gery. A number of different materials are available for this type of operation, such as autologous vein or pros-thetic grafts comprised of polytetrafluoroethylene (PTFE) or Dacron®. Prosthetic materials are used especially in the treatment of peripheral artery disease, such as in aortoiliac or femoropopliteal bypass surgery. The present report will thus focus on this area in order to examine the effectiveness of different bypass materials. Among the efforts being made to refine the newly introduced DRG system in Germany, analysing the different bypass materials used in vascular surgery is particularly important. Indeed, in its current version the German DRG system does not distinguish between bypass materials in terms of reimbursement rates. Differences in cost structures are thus of especial interest to hospitals in their budget calculations, whereas both private and statutory health insurance funds are primarily interested in long-term results and their costs. Objectives The goal of this HTA is to compare the different bypass materials used in vascular surgery in terms of their medical efficiency and cost-effectiveness, as well as with regard to their ethical, social and legal implications. In addition, this report aims to point out the areas in which further medical, epidemiological and health economic research is still needed. Methods Relevant publications were identified by means of a structured search of databases accessed through the German Institute of Medical Documentation and Information (DIMDI), as well as by

  14. Two pore channel 2 (TPC2) inhibits autophagosomal-lysosomal fusion by alkalinizing lysosomal pH.

    Science.gov (United States)

    Lu, Yingying; Hao, Bai-Xia; Graeff, Richard; Wong, Connie W M; Wu, Wu-Tian; Yue, Jianbo

    2013-08-16

    Autophagy is an evolutionarily conserved lysosomal degradation pathway, yet the underlying mechanisms remain poorly understood. Nicotinic acid adenine dinucleotide phosphate (NAADP), one of the most potent Ca(2+) mobilizing messengers, elicits Ca(2+) release from lysosomes via the two pore channel 2 (TPC2) in many cell types. Here we found that overexpression of TPC2 in HeLa or mouse embryonic stem cells inhibited autophagosomal-lysosomal fusion, thereby resulting in the accumulation of autophagosomes. Treatment of TPC2 expressing cells with a cell permeant-NAADP agonist, NAADP-AM, further induced autophagosome accumulation. On the other hand, TPC2 knockdown or treatment of cells with Ned-19, a NAADP antagonist, markedly decreased the accumulation of autophagosomes. TPC2-induced accumulation of autophagosomes was also markedly blocked by ATG5 knockdown. Interestingly, inhibiting mTOR activity failed to increase TPC2-induced autophagosome accumulation. Instead, we found that overexpression of TPC2 alkalinized lysosomal pH, and lysosomal re-acidification abolished TPC2-induced autophagosome accumulation. In addition, TPC2 overexpression had no effect on general endosomal-lysosomal degradation but prevented the recruitment of Rab-7 to autophagosomes. Taken together, our data demonstrate that TPC2/NAADP/Ca(2+) signaling alkalinizes lysosomal pH to specifically inhibit the later stage of basal autophagy progression.

  15. Bypass Gástrico BII.

    OpenAIRE

    Himpens, Jaques

    2014-01-01

    Hay varias técnicas de bypass gástrico para la reducción del peso, la cual se decide dependiendo de la historia, hábitos dietéticos, evaluación psicológica, estado médico, reflujo gastroesofágico, diabetes. El bypass gástrico Roux-en-Y es la única opción en 50% de los pacientes debido a reflujo, diabetes o ambas. Estos pacientes tienen ciertas características como el IMC, síndrome metabólico y diabetes. Los pacientes obesos presentan mayor resistencia a la insulina, que se encuentra regulada ...

  16. Reconnaissance Report Yolo Bypass, California

    Science.gov (United States)

    1992-03-01

    proximity of these plans, a plan for one area could not be constructed separately without creating major hydraulic impacts to the other area. In essence ...native woody species which may be commonly found include eucalyptus , acacia, giant reed, and honey locust. Yolo Bypass. In the project area, vegetation...forbs form an often dense ground cover. Non- native woody species which may be commonly found include eucalyptus , acacia, giant reed and honey locust

  17. Cationic lipids delay the transfer of plasmid DNA to lysosomes.

    Science.gov (United States)

    Wattiaux, R; Jadot, M; Laurent, N; Dubois, F; Wattiaux-De Coninck, S

    1996-10-14

    Plasmid 35S DNA, naked or associated with different cationic lipid preparations was injected to rats. Subcellular distribution of radioactivity in the liver one hour after injection, was established by centrifugation methods. Results show that at that time, 35S DNA has reached lysosomes. On the contrary, when 35S DNA was complexed with lipids, radioactivity remains located in organelles whose distribution after differential and isopycnic centrifugation, is clearly distinct from that of arylsulfatase, lysosome marker enzyme. Injection of Triton WR 1339, a specific density perturbant of lysosomes, four days before 35S DNA injection causes a density decrease of radioactivity bearing structures, apparent one hour after naked 35S DNA injection but visible only after more than five hours, when 35S DNA associated with a cationic lipid is injected. These observations show that cationic lipids delay the transfer to lysosomes, of plasmid DNA taken up by the liver.

  18. Secondary Lysosomal Changes in Liver in Preclinical Drug Development

    Institute of Scientific and Technical Information of China (English)

    Vincent P. Meador; D. V. M.; Ph. D.; Diplomate ACVP

    2005-01-01

    @@ Lysosomes are intracytoplasmic membrane-bound organelles that function to degrade intracellular substances by enzymatic digestion. They occur normally in all cells, being especially prominent in phagocytic cells of the reticuloendothelial system.

  19. Endosome-lysosomes, ubiquitin and neurodegeneration.

    Science.gov (United States)

    Mayer, R J; Tipler, C; Arnold, J; Laszlo, L; Al-Khedhairy, A; Lowe, J; Landon, M

    1996-01-01

    Before the advent of ubiquitin immunochemistry and immunogold electron microscopy, there was no known intracellular molecular commonality between neurodegenerative diseases. The application of antibodies which primarily detect ubiquitin protein conjugates has shown that all of the human and animal idiopathic and transmissible chronic neurodegenerative diseases, (including Alzheimer's disease (AD), Lewy body disease (LBD), amyotrophic lateral sclerosis (ALS), Creutzfeldt-Jakob disease (CJD) and scrapie) are related by some form of intraneuronal inclusion which contains ubiquitin protein conjugates. In addition, disorders such as Alzheimer's disease, CJD and sheep scrapie, are characterised by deposits of amyloid, arising through incomplete breakdown of membrane proteins which may be associated with cytoskeletal reorganisation. Although our knowledge about these diseases is increasing, they remain largely untreatable. Recently, attention has focused on the mechanisms of production of different types of amyloid and the likely involvement within cells of the endosome-lysosome system, organelles which are immuno-positive for ubiquitin protein conjugates. These organelles may be 'bioreactor' sites for the unfolding and partial degradation of membrane proteins to generate the amyloid materials or their precursors which subsequently become expelled from the cell, or are released from dead cells, and accumulate as pathological entities. Such common features of the disease processes give new direction to therapeutic intervention.

  20. Lysosomal trafficking functions of mucolipin-1 in murine macrophages

    Directory of Open Access Journals (Sweden)

    Dang Hope

    2007-12-01

    Full Text Available Abstract Background Mucolipidosis Type IV is currently characterized as a lysosomal storage disorder with defects that include corneal clouding, achlorhydria and psychomotor retardation. MCOLN1, the gene responsible for this disease, encodes the protein mucolipin-1 that belongs to the "Transient Receptor Potential" family of proteins and has been shown to function as a non-selective cation channel whose activity is modulated by pH. Two cell biological defects that have been described in MLIV fibroblasts are a hyperacidification of lysosomes and a delay in the exit of lipids from lysosomes. Results We show that mucolipin-1 localizes to lysosomal compartments in RAW264.7 mouse macrophages that show subcompartmental accumulations of endocytosed molecules. Using stable RNAi clones, we show that mucolipin-1 is required for the exit of lipids from these compartments, for the transport of endocytosed molecules to terminal lysosomes, and for the transport of the Major Histocompatibility Complex II to the plasma membrane. Conclusion Mucolipin-1 functions in the efficient exit of molecules, destined for various cellular organelles, from lysosomal compartments.

  1. Lysosomal enzymes and their receptors in invertebrates: an evolutionary perspective.

    Science.gov (United States)

    Kumar, Nadimpalli Siva; Bhamidimarri, Poorna M

    2015-01-01

    Lysosomal biogenesis is an important process in eukaryotic cells to maintain cellular homeostasis. The key components that are involved in the biogenesis such as the lysosomal enzymes, their modifications and the mannose 6-phosphate receptors have been well studied and their evolutionary conservation across mammalian and non-mammalian vertebrates is clearly established. Invertebrate lysosomal biogenesis pathway on the other hand is not well studied. Although, details on mannose 6-phosphate receptors and enzymes involved in lysosomal enzyme modifications were reported earlier, a clear cut pathway has not been established. Recent research on the invertebrate species involving biogenesis of lysosomal enzymes suggests a possible conserved pathway in invertebrates. This review presents certain observations based on these processes that include biochemical, immunological and functional studies. Major conclusions include conservation of MPR-dependent pathway in higher invertebrates and recent evidence suggests that MPR-independent pathway might have been more prominent among lower invertebrates. The possible components of MPR-independent pathway that may play a role in lysosomal enzyme targeting are also discussed here.

  2. Lysosomal storage disorders: Molecular basis and laboratory testing

    Directory of Open Access Journals (Sweden)

    Filocamo Mirella

    2011-03-01

    Full Text Available Abstract Lysosomal storage disorders (LSDs are a large group of more than 50 different inherited metabolic diseases which, in the great majority of cases, result from the defective function of specific lysosomal enzymes and, in cases, of non-enzymatic lysosomal proteins or non-lysosomal proteins involved in lysosomal biogenesis. The progressive lysosomal accumulation of undegraded metabolites results in generalised cell and tissue dysfunction, and, therefore, multi-systemic pathology. Storage may begin during early embryonic development, and the clinical presentation for LSDs can vary from an early and severe phenotype to late-onset mild disease. The diagnosis of most LSDs--after accurate clinical/paraclinical evaluation, including the analysis of some urinary metabolites--is based mainly on the detection of a specific enzymatic deficiency. In these cases, molecular genetic testing (MGT can refine the enzymatic diagnosis. Once the genotype of an individual LSD patient has been ascertained, genetic counselling should include prediction of the possible phenotype and the identification of carriers in the family at risk. MGT is essential for the identification of genetic disorders resulting from non-enzymatic lysosomal protein defects and is complementary to biochemical genetic testing (BGT in complex situations, such as in cases of enzymatic pseudodeficiencies. Prenatal diagnosis is performed on the most appropriate samples, which include fresh or cultured chorionic villus sampling or cultured amniotic fluid. The choice of the test--enzymatic and/or molecular--is based on the characteristics of the defect to be investigated. For prenatal MGT, the genotype of the family index case must be known. The availability of both tests, enzymatic and molecular, enormously increases the reliability of the entire prenatal diagnostic procedure. To conclude, BGT and MGT are mostly complementary for post- and prenatal diagnosis of LSDs. Whenever genotype

  3. History of cardiopulmonary bypass (CPB).

    Science.gov (United States)

    Hessel, Eugene A

    2015-06-01

    The development of cardiopulmonary bypass (CPB), thereby permitting open-heart surgery, is one of the most important advances in medicine in the 20th century. Many currently practicing cardiac anesthesiologists, cardiac surgeons, and perfusionists are unaware of how recently it came into use (60 years) and how much the practice of CPB has changed during its short existence. In this paper, the development of CPB and the many changes and progress that has taken place over this brief period of time, making it a remarkably safe endeavor, are reviewed. The many as yet unresolved questions are also identified, which sets the stage for the other papers in this issue of this journal.

  4. Gut hormones and gastric bypass

    DEFF Research Database (Denmark)

    Holst, Jens J.

    2016-01-01

    , oxyntomodulin, neurotensin and peptide YY (PYY). However, some proximal hormones also show changes probably reflecting that the distribution of these hormones is not restricted to the bypassed segments of the gut. Thus, cholecystokinin responses are increased, whereas gastric inhibitory polypeptide responses......%. The increased insulin responses after the operation, one of the important mechanisms whereby these operations cause diabetes remission, is clearly due to a combination of the increased glucose absorption rates and the exaggerated GLP-1 secretion. The hormonal changes are therefore very important...

  5. α-Defensin HD5 Inhibits Human Papillomavirus 16 Infection via Capsid Stabilization and Redirection to the Lysosome

    Directory of Open Access Journals (Sweden)

    Mayim E. Wiens

    2017-01-01

    Full Text Available α-Defensins are an important class of abundant innate immune effectors that are potently antiviral against a number of nonenveloped viral pathogens; however, a common mechanism to explain their ability to block infection by these unrelated viruses is lacking. We previously found that human defensin 5 (HD5 blocks a critical host-mediated proteolytic processing step required for human papillomavirus (HPV infection. Here, we show that bypassing the requirement for this cleavage failed to abrogate HD5 inhibition. Instead, HD5 altered HPV trafficking in the cell. In the presence of an inhibitory concentration of HD5, HPV was internalized and reached the early endosome. The internalized capsid became permeable to antibodies and proteases; however, HD5 prevented dissociation of the viral capsid from the genome, reduced viral trafficking to the trans-Golgi network, redirected the incoming viral particle to the lysosome, and accelerated the degradation of internalized capsid proteins. This mechanism is equivalent to the mechanism by which HD5 inhibits human adenovirus. Thus, our data support capsid stabilization and redirection to the lysosome during infection as a general antiviral mechanism of α-defensins against nonenveloped viruses.

  6. α-Defensin HD5 Inhibits Human Papillomavirus 16 Infection via Capsid Stabilization and Redirection to the Lysosome

    Science.gov (United States)

    Wiens, Mayim E.

    2017-01-01

    ABSTRACT α-Defensins are an important class of abundant innate immune effectors that are potently antiviral against a number of nonenveloped viral pathogens; however, a common mechanism to explain their ability to block infection by these unrelated viruses is lacking. We previously found that human defensin 5 (HD5) blocks a critical host-mediated proteolytic processing step required for human papillomavirus (HPV) infection. Here, we show that bypassing the requirement for this cleavage failed to abrogate HD5 inhibition. Instead, HD5 altered HPV trafficking in the cell. In the presence of an inhibitory concentration of HD5, HPV was internalized and reached the early endosome. The internalized capsid became permeable to antibodies and proteases; however, HD5 prevented dissociation of the viral capsid from the genome, reduced viral trafficking to the trans-Golgi network, redirected the incoming viral particle to the lysosome, and accelerated the degradation of internalized capsid proteins. This mechanism is equivalent to the mechanism by which HD5 inhibits human adenovirus. Thus, our data support capsid stabilization and redirection to the lysosome during infection as a general antiviral mechanism of α-defensins against nonenveloped viruses. PMID:28119475

  7. The Link Between Lysosomal Storage Disorders and More Common Diseases

    Directory of Open Access Journals (Sweden)

    Michael Beck MD

    2016-12-01

    Full Text Available In the last decades, it has become more and more evident that lysosomal storage disorders and common neurodegenerative diseases such as Alzheimer and Parkinson diseases have clinical, neuropathological, and genetic features in common, including lysosomal dysfunction and impaired autophagy. Patients with Gaucher and even carriers of Gaucher disease have an increased risk to develop Parkinson disease. Likewise, individuals who are heterozygous for a mutation of a gene that causes an adult form of neuronal ceroid lipofuscinosis are more likely to be affected by a form of frontotemporal dementia in their later life. A further example is the gene NAGLU encoding the enzyme α-N-acetylglucosaminidase, which is deficient in patients with mucopolysaccharidosis type IIIB. Mutations of the NAGLU gene have been observed in patients affected by an axonal neuropathy. An interesting unexpected finding was the link between stuttering and genes that are essential for the function of all lysosomal enzymes. This review will present some example of the association of lysosomal storage disorders and neurodegenerative disease and discuss possible pathogenic mechanisms that are common to both conditions. The understanding of the pathophysiology of the endosomal–lysosomal–autophagic system may help to develop drugs, which might provide benefit not only for patients with rare lysosomal storage disorders but also for individuals affected by more common diseases.

  8. TRPML1: an ion channel in the lysosome.

    Science.gov (United States)

    Wang, Wuyang; Zhang, Xiaoli; Gao, Qiong; Xu, Haoxing

    2014-01-01

    The first member of the mammalian mucolipin TRP channel subfamily (TRPML1) is a cation-permeable channel that is predominantly localized on the membranes of late endosomes and lysosomes (LELs) in all mammalian cell types. In response to the regulatory changes of LEL-specific phosphoinositides or other cellular cues, TRPML1 may mediate the release of Ca(2+) and heavy metal Fe(2+)/Zn(2+)ions into the cytosol from the LEL lumen, which in turn may regulate membrane trafficking events (fission and fusion), signal transduction, and ionic homeostasis in LELs. Human mutations in TRPML1 result in type IV mucolipidosis (ML-IV), a childhood neurodegenerative lysosome storage disease. At the cellular level, loss-of-function mutations of mammalian TRPML1 or its C. elegans or Drosophila homolog gene results in lysosomal trafficking defects and lysosome storage. In this chapter, we summarize recent advances in our understandings of the cell biological and channel functions of TRPML1. Studies on TRPML1's channel properties and its regulation by cellular activities may provide clues for developing new therapeutic strategies to delay neurodegeneration in ML-IV and other lysosome-related pediatric diseases.

  9. Epicardial ultrasound in coronary artery bypass surgery

    NARCIS (Netherlands)

    Budde, R.P.J.

    2005-01-01

    Chapter 1 Coronary artery bypass surgery (CABG) is traditionally performed via a median sternotomy approach on cardiopulmonary bypass (arrested heart). Since the mid 1990ties, beating heart, minimally invasive and even totally endoscopic CABG are (re)explored. In all approaches to CABG, the surgeo

  10. Multimodality imaging of coronary artery bypass grafts

    NARCIS (Netherlands)

    Salm, Liesbeth Pauline

    2006-01-01

    This thesis describes multiple imaging modalities to examine coronary artery bypass grafts, and the research which was performed to further develop noninvasive imaging techniques to detect stenoses in native coronary arteries and bypass grafts in patients who experienced recurrent chest pain after c

  11. Parkinson's Disease Shares the Lysosome with Gaucher's Disease

    Science.gov (United States)

    Dawson, Ted M.; Dawson, Valina L.

    2015-01-01

    Summary The second most common neurodegenerative disorder, Parkinson's disease (PD) is an age dependent progressive neurodegenerative disorder that affects movement. While many of the causes of PD remain unclear, a consistent finding in PD is the abnormal accumulation of α-synuclein that has lead to the widely held notion that PD is a synucleinopathy. In a recent Cell manuscript Mazzuli et al., provide a potential mechanistic link between Gaucher's disease, a glycolipid lysosomal storage disorder due to Glucocerebrocidase (GBA) deficiency and PD. The authors reveal a reciprocal connection between the loss of GBA activity and accumulation of α-synuclein in the lysosome establishing a bidirectional positive feed back loop with pathologic consequences. These findings should stimulate further work on role of the lysosome in PD pathogenesis and the identification of new treatment strategies for PD. PMID:21753118

  12. PDT: loss of autophagic cytoprotection after lysosomal photodamage

    Science.gov (United States)

    Kessel, David; Price, Michael

    2012-02-01

    Photodynamic therapy is known to evoke both autophagy and apoptosis. Apoptosis is an irreversible death pathway while autophagy can serve a cytoprotective function. In this study, we examined two photosensitizing agents that target lysosomes, although they differ in the reactive oxygen species (ROS) formed during irradiation. With both agents, the 'shoulder' on the PDT dose-response curve was substantially attenuated, consistent with loss of a cytoprotective pathway. In contrast, this 'shoulder' is commonly observed when PDT targets mitochondria or the ER. We propose that lysosomal targets may offer the possibility of promoting PDT efficacy by eliminating a potentially protective pathway.

  13. Lysosome stability during lytic infection by simian virus 40.

    Science.gov (United States)

    Einck, K H; Norkin, L C

    1979-01-01

    By 48 h postinfection, 40--80% of SV40-infected CV-1 cells have undergone irreversible injury as indicated by trypan blue staining. Nevertheless, at this time the lysosomes of these cells appear as discrete structures after vital staining with either acridine orange or neutral red. Lysosomes, vitally stained with neutral red at 24 h postinfection, were still intact in cells stained with trypan blue at 48 h. Acid phosphatase activity is localized in discrete cytoplasmic particles at 48 h, as indicated by histochemical staining of both fixed and unfixed cells.

  14. Importance of lysosomal cysteine proteases in lung disease

    Directory of Open Access Journals (Sweden)

    Chapman Harold A

    2000-11-01

    Full Text Available Abstract The human lysosomal cysteine proteases are a family of 11 proteases whose members include cathepsins B, C, H, L, and S. The biology of these proteases was largely ignored for decades because of their lysosomal location and the belief that their function was limited to the terminal degradation of proteins. In the past 10 years, this view has changed as these proteases have been found to have specific functions within cells. This review highlights some of these functions, specifically their roles in matrix remodeling and in regulating the immune response, and their relationship to lung diseases.

  15. The endoplasmic reticulum, not the pH gradient, drives calcium refilling of lysosomes.

    Science.gov (United States)

    Garrity, Abigail G; Wang, Wuyang; Collier, Crystal Md; Levey, Sara A; Gao, Qiong; Xu, Haoxing

    2016-05-23

    Impaired homeostasis of lysosomal Ca(2+) causes lysosome dysfunction and lysosomal storage diseases (LSDs), but the mechanisms by which lysosomes acquire and refill Ca(2+) are not known. We developed a physiological assay to monitor lysosomal Ca(2+) store refilling using specific activators of lysosomal Ca(2+) channels to repeatedly induce lysosomal Ca(2+) release. In contrast to the prevailing view that lysosomal acidification drives Ca(2+) into the lysosome, inhibiting the V-ATPase H(+) pump did not prevent Ca(2+) refilling. Instead, pharmacological depletion or chelation of Endoplasmic Reticulum (ER) Ca(2+) prevented lysosomal Ca(2+) stores from refilling. More specifically, antagonists of ER IP3 receptors (IP3Rs) rapidly and completely blocked Ca(2+) refilling of lysosomes, but not in cells lacking IP3Rs. Furthermore, reducing ER Ca(2+) or blocking IP3Rs caused a dramatic LSD-like lysosome storage phenotype. By closely apposing each other, the ER may serve as a direct and primary source of Ca(2+)for the lysosome.

  16. Methods for monitoring Ca(2+) and ion channels in the lysosome.

    Science.gov (United States)

    Zhong, Xi Zoë; Yang, Yiming; Sun, Xue; Dong, Xian-Ping

    2016-12-09

    Lysosomes and lysosome-related organelles are emerging as intracellular Ca(2+) stores and play important roles in a variety of membrane trafficking processes, including endocytosis, exocytosis, phagocytosis and autophagy. Impairment of lysosomal Ca(2+) homeostasis and membrane trafficking has been implicated in many human diseases such as lysosomal storage diseases (LSDs), neurodegeneration, myopathy and cancer. Lysosomal membrane proteins, in particular ion channels, are crucial for lysosomal Ca(2+) signaling. Compared with ion channels in the plasma membrane, lysosomal ion channels and their roles in lysosomal Ca(2+) signaling are less understood, largely due to their intracellular localization and the lack of feasible functional assays directly applied to the native environment. Recent advances in biomedical methodology have made it possible to directly investigate ion channels in the lysosomal membrane. In this review, we provide a summary of the newly developed methods for monitoring lysosomal Ca(2+) and ion channels, as well as the recent discovery of lysosomal ion channels and their significances in intracellular Ca(2+) signaling. These new techniques will expand our research scope and our understanding of the nature of lysosomes and lysosome-related diseases.

  17. Genomic expression analyses reveal lysosomal, innate immunity proteins, as disease correlates in murine models of a lysosomal storage disorder.

    Directory of Open Access Journals (Sweden)

    Md Suhail Alam

    Full Text Available Niemann-Pick Type C (NPC disease is a rare, genetic, lysosomal disorder with progressive neurodegeneration. Poor understanding of the pathophysiology and a lack of blood-based diagnostic markers are major hurdles in the treatment and management of NPC and several additional, neurological lysosomal disorders. To identify disease severity correlates, we undertook whole genome expression profiling of sentinel organs, brain, liver, and spleen of Balb/c Npc1(-/- mice relative to Npc1(+/- at an asymptomatic stage, as well as early- and late-symptomatic stages. Unexpectedly, we found prominent up regulation of innate immunity genes with age-dependent change in their expression, in all three organs. We shortlisted a set of 12 secretory genes whose expression steadily increased with age in both brain and liver, as potential plasma correlates of neurological and/or liver disease. Ten were innate immune genes with eight ascribed to lysosomes. Several are known to be elevated in diseased organs of murine models of other lysosomal diseases including Gaucher's disease, Sandhoff disease and MPSIIIB. We validated the top candidate lysozyme, in the plasma of Npc1(-/- as well as Balb/c Npc1(nmf164 mice (bearing a point mutation closer to human disease mutants and show its reduction in response to an emerging therapeutic. We further established elevation of innate immunity in Npc1(-/- mice through multiple functional assays including inhibition of bacterial infection as well as cellular analysis and immunohistochemistry. These data revealed neutrophil elevation in the Npc1(-/- spleen and liver (where large foci were detected proximal to damaged tissue. Together our results yield a set of lysosomal, secretory innate immunity genes that have potential to be developed as pan or specific plasma markers for neurological diseases associated with lysosomal storage and where diagnosis is a major problem. Further, the accumulation of neutrophils in diseased organs

  18. Syntaxin 7 and VAMP-7 are soluble N-ethylmaleimide-sensitive factor attachment protein receptors required for late endosome-lysosome and homotypic lysosome fusion in alveolar macrophages.

    Science.gov (United States)

    Ward, D M; Pevsner, J; Scullion, M A; Vaughn, M; Kaplan, J

    2000-07-01

    Endocytosis in alveolar macrophages can be reversibly inhibited, permitting the isolation of endocytic vesicles at defined stages of maturation. Using an in vitro fusion assay, we determined that each isolated endosome population was capable of homotypic fusion. All vesicle populations were also capable of heterotypic fusion in a temporally specific manner; early endosomes, isolated 4 min after internalization, could fuse with endosomes isolated 8 min after internalization but not with 12-min endosomes or lysosomes. Lysosomes fuse with 12-min endosomes but not with earlier endosomes. Using homogenous populations of endosomes, we have identified Syntaxin 7 as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) required for late endosome-lysosome and homotypic lysosome fusion in vitro. A bacterially expressed human Syntaxin 7 lacking the transmembrane domain inhibited homotypic late endosome and lysosome fusion as well as heterotypic late endosome-lysosome fusion. Affinity-purified antibodies directed against Syntaxin 7 also inhibited lysosome fusion in vitro but had no affect on homotypic early endosome fusion. Previous work suggested that human VAMP-7 (vesicle-associated membrane protein-7) was a SNARE required for late endosome-lysosome fusion. A bacterially expressed human VAMP-7 lacking the transmembrane domain inhibited both late endosome-lysosome fusion and homotypic lysosome fusion in vitro. These studies indicate that: 1) fusion along the endocytic pathway is a highly regulated process, and 2) two SNARE molecules, Syntaxin 7 and human VAMP-7, are involved in fusion of vesicles in the late endocytic pathway in alveolar macrophages.

  19. The relationship between Cd-induced autophagy and lysosomal activation in WRL-68 cells.

    Science.gov (United States)

    Meng, Su-Fang; Mao, Wei-Ping; Wang, Fang; Liu, Xiao-Qian; Shao, Luan-Luan

    2015-11-01

    This study shows that Cd induces autophagy in the human's embryonic normal liver cell line (WRL-68). The expression of LC3B-II and the mature cathepsin L were analyzed by Western blotting. The autophagosomes and lysosomes were directly visualized by electron microscopy and confocal microscopy analysis in Cd-exposed WRL-68 cells. In this study, we first found that autophagy induced the activation of lysosomal function in WRL-68 cells. The lysosomal activation was markedly decreased when the cells were co-treated with 3-MA (an inhibitor of autophagy). Secondly, we provided the evidence that the activation of lysosomal function depended on autophagosome-lysosome fusion. The colocalization of lysosome-associated membrane protein-2 (LAMP2) and GFP-LC3 was significantly reduced, when they were treated with thapsigargin (an inhibitor of autophagosome-lysosome fusion). We demonstrated that deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation, which suggests that lysosomal activation occurring in the course of autophagy is dependent on autophagosome-lysosome fusion. Thirdly, we provided evidence that the activation of lysosomal function was associated with lysosomal acid. We investigated the relationship between autophagosome-lysosome fusion and pH in acidic compartments by visualizing fusion process in WRL-68 cells. This suggests that increasing pH in acidic compartments in WRL-68 cells inhibits the autophagosome-lysosome fusion. Finally, we found that the activation of lysosomal function was associated with Ca(2+) stores and the intracellular Ca(2+) channels or pumps were possibly pH-dependent.

  20. 30 CFR 57.19018 - Overtravel by-pass switches.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the... switch is held in the closed position by the hoistman. The overtravel by-pass switch shall...

  1. 30 CFR 56.19018 - Overtravel by-pass switches.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the... switch is held in the closed position by the hoistman. The overtravel by-pass switch shall...

  2. 34 CFR 76.677 - Continuation of a bypass.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Continuation of a bypass. 76.677 Section 76.677... Be Met by the State and Its Subgrantees? Procedures for Bypass § 76.677 Continuation of a bypass. The Secretary continues a bypass until the Secretary determines that the grantee or subgrantee will meet...

  3. Neuronopathic Lysosomal Storage Diseases: Clinical and Pathologic Findings

    Science.gov (United States)

    Prada, Carlos E.; Grabowski, Gregory A.

    2013-01-01

    Background: The lysosomal--autophagocytic system diseases (LASDs) affect multiple body systems including the central nervous system (CNS). The progressive CNS pathology has its onset at different ages, leading to neurodegeneration and early death. Methods: Literature review provided insight into the current clinical neurological findings,…

  4. PIG7 promotes leukemia cell chemosensitivity via lysosomal membrane permeabilization.

    Science.gov (United States)

    Liu, Jiazhuo; Peng, Leiwen; Niu, Ting; Wu, Yu; Li, Jianjun; Wang, Fangfang; Zheng, Yuhuan; Liu, Ting

    2016-01-26

    PIG7 localizes to lysosomal membrane in leukemia cells. Our previous work has shown that transduction of pig7 into a series of leukemia cell lines did not result in either apoptosis or differentiation of most tested cell lines. Interestingly, it did significantly sensitize these cell lines to chemotherapeutic drugs. Here, we further investigated the mechanism underlying pig7-induced improved sensitivity of acute leukemia cells to chemotherapy. Our results demonstrated that the sensitization effect driven by exogenous pig7 was more effective in drug-resistant leukemia cell lines which had lower endogenous pig7 expression. Overexpression of pig7 did not directly activate the caspase apoptotic pathway, but decreased the lysosomal stability. The expression of pig7 resulted in lysosomal membrane permeabilization (LMP) and lysosomal protease (e.g. cathepsin B, D, L) release. Moreover, we also observed increased reactive oxygen species (ROS) and decreased mitochondrial membrane potential (ΔΨm) induced by pig7. Some autophagy markers such as LC3I/II, ATG5 and Beclin-1, and necroptosis maker MLKL were also stimulated. However, intrinsic antagonism such as serine/cysteine protease inhibitors Spi2A and Cystatin C prevented downstream effectors from triggering leukemia cells, which were only on the "verge of apoptosis". When combined with chemotherapy, LMP increased and more proteases were released. Once this process was beyond the limit of intrinsic antagonism, it induced programmed cell death cooperatively via caspase-independent and caspase-dependent pathways.

  5. Recent advances in gene therapy for lysosomal storage disorders

    Directory of Open Access Journals (Sweden)

    Rastall DP

    2015-06-01

    Full Text Available David PW Rastall,1 Andrea Amalfitano1,2 1Department of Microbiology and Molecular Genetics, 2Department of Pediatrics, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA Abstract: Lysosomal storage disorders (LSDs are a group of genetic diseases that result in metabolic derangements of the lysosome. Most LSDs are due to the genetic absence of a single catabolic enzyme, causing accumulation of the enzyme's substrate within the lysosome. Over time, tissue-specific substrate accumulations result in a spectrum of symptoms and disabilities that vary by LSD. LSDs are promising targets for gene therapy because delivery of a single gene into a small percentage of the appropriate target cells may be sufficient to impact the clinical course of the disease. Recently, there have been several significant advancements in the potential for gene therapy of these disorders, including the first human trials. Future clinical trials will build upon these initial attempts, with an improved understanding of immune system responses to gene therapy, the obstacle that the blood–brain barrier poses for neuropathic LSDs, as well other biological barriers that, when overcome, may facilitate gene therapy for LSDs. In this manuscript, we will highlight the recent innovations in gene therapy for LSDs and discuss the clinical limitations that remain to be overcome, with the goal of fostering an understanding and further development of this important field. Keywords: human trials, clinical trials, gene therapy, lysosomal storage disease, blood-brain barrier, adeno-associated virus, lentivirus, adenovirus 

  6. The frequency of lysosomal storage diseases in The Netherlands

    NARCIS (Netherlands)

    Poorthuis, BJHM; Wevers, RA; Kleijer, WJ; Groener, JEM; de Jong, JGN; van Weely, S; Niezen-Koning, KE; van Diggelen, OP

    1999-01-01

    We have calculated the relative frequency and the birth prevalence of lysosomal storage diseases (LSDs) in The Netherlands based on all 963 enzymatically confirmed cases diagnosed during the period 1970-1996. The combined birth prevalence for all LSDs is 14 per 100,000 live births. Glycogenosis type

  7. Lysosomal acid phosphatase is internalized via clathrin-coated pits

    NARCIS (Netherlands)

    Klumperman, J.; Hille, A.; Geuze, H.J.; Peters, C.; Brodsky, F.M.; Figura, K. von

    1992-01-01

    The presence of lysosomal acid phosphatase (LAP) in coated pits at the plasma membrane was investigated by immunocytochemistry in thymidine kinase negative mouse L-cells (Ltk-) and baby hamster kidney (BHK) cells overexpressing human LAP (Ltk-LAP and BHK-LAP cells). Double immunogold labeling showed

  8. Release and uptake of lysosomal enzymes : studied in cultured cells

    NARCIS (Netherlands)

    D.J.J. Halley (Dicky)

    1980-01-01

    textabstractThe purpose of the experimental work described in this thesiswas to investigate some aspects of the release and uptake of lysosomal enzymes. The experiments involved the use of normal human and animal fibroblasts and some other cell types such as hepatocytes and hepatoma cells as sources

  9. Coronary Bypass Surgery in a 105-Year-Old Patient with Cardiopulmonary Bypass

    Directory of Open Access Journals (Sweden)

    Temucin Noyan Ogus

    2010-01-01

    Full Text Available Coronary artery bypass grafting is one of the routine daily surgical procedures in the current era. Parallel to the increasing life expectancy, cardiac surgery is commonly performed in octogenarians. However, literature consists of only seldom reports of coronary artery bypass grafting in patients above 90 years of age. In this report, we present our management strategy in a 105-year-old patient who underwent coronary artery bypass grafting at our institution.

  10. Glycolipid-dependent sorting of melanosomal from lysosomal membrane proteins by lumenal determinants

    NARCIS (Netherlands)

    Groux-Degroote, S.; Dijk, S.M. van; Wolthoorn, J.; Neumann, S.; Theos, A.C.; Mazière, A.M. de; Klumperman, J.; Meer, G. van; Sprong, H.

    2008-01-01

    Melanosomes are lysosome-related organelles that coexist with lysosomes in mammalian pigment cells. Melanosomal and lysosomal membrane proteins share similar sorting signals in their cytoplasmic tail, raising the question how they are segregated. We show that in control melanocytes, the melanosomal

  11. Exhaust gas bypass valve control for thermoelectric generator

    Science.gov (United States)

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  12. Fusion of lysosomes with secretory organelles leads to uncontrolled exocytosis in the lysosomal storage disease mucolipidosis type IV.

    Science.gov (United States)

    Park, Soonhong; Ahuja, Malini; Kim, Min Seuk; Brailoiu, G Cristina; Jha, Archana; Zeng, Mei; Baydyuk, Maryna; Wu, Ling-Gang; Wassif, Christopher A; Porter, Forbes D; Zerfas, Patricia M; Eckhaus, Michael A; Brailoiu, Eugen; Shin, Dong Min; Muallem, Shmuel

    2016-02-01

    Mutations in TRPML1 cause the lysosomal storage disease mucolipidosis type IV (MLIV). The role of TRPML1 in cell function and how the mutations cause the disease are not well understood. Most studies focus on the role of TRPML1 in constitutive membrane trafficking to and from the lysosomes. However, this cannot explain impaired neuromuscular and secretory cells' functions that mediate regulated exocytosis. Here, we analyzed several forms of regulated exocytosis in a mouse model of MLIV and, opposite to expectations, we found enhanced exocytosis in secretory glands due to enlargement of secretory granules in part due to fusion with lysosomes. Preliminary exploration of synaptic vesicle size, spontaneous mEPSCs, and glutamate secretion in neurons provided further evidence for enhanced exocytosis that was rescued by re-expression of TRPML1 in neurons. These features were not observed in Niemann-Pick type C1. These findings suggest that TRPML1 may guard against pathological fusion of lysosomes with secretory organelles and suggest a new approach toward developing treatment for MLIV.

  13. MHD Energy Bypass Scramjet Engine

    Science.gov (United States)

    Mehta, Unmeel B.; Bogdanoff, David W.; Park, Chul; Arnold, Jim (Technical Monitor)

    2001-01-01

    Revolutionary rather than evolutionary changes in propulsion systems are most likely to decrease cost of space transportation and to provide a global range capability. Hypersonic air-breathing propulsion is a revolutionary propulsion system. The performance of scramjet engines can be improved by the AJAX energy management concept. A magneto-hydro-dynamics (MHD) generator controls the flow and extracts flow energy in the engine inlet and a MHD accelerator downstream of the combustor accelerates the nozzle flow. A progress report toward developing the MHD technology is presented herein. Recent theoretical efforts are reviewed and ongoing experimental efforts are discussed. The latter efforts also include an ongoing collaboration between NASA, the US Air Force Research Laboratory, US industry, and Russian scientific organizations. Two of the critical technologies, the ionization of the air and the MHD accelerator, are briefly discussed. Examples of limiting the combustor entrance Mach number to a low supersonic value with a MHD energy bypass scheme are presented, demonstrating an improvement in scramjet performance. The results for a simplified design of an aerospace plane show that the specific impulse of the MHD-bypass system is better than the non-MHD system and typical rocket over a narrow region of flight speeds and design parameters. Equilibrium ionization and non-equilibrium ionization are discussed. The thermodynamic condition of air at the entrance of the engine inlet determines the method of ionization. The required external power for non-equilibrium ionization is computed. There have been many experiments in which electrical power generation has successfully been achieved by magneto-hydrodynamic (MHD) means. However, relatively few experiments have been made to date for the reverse case of achieving gas acceleration by the MHD means. An experiment in a shock tunnel is described in which MHD acceleration is investigated experimentally. MHD has several

  14. Prophylactic digitalization for coronary artery bypass surgery.

    Science.gov (United States)

    Johnson, L W; Dickstein, R A; Fruehan, C T; Kane, P; Potts, J L; Smulyan, H; Webb, W R; Eich, R H

    1976-05-01

    One hundred and twenty patients undergoing aortocoronary bypass procedures were randomly placed into control and digitalized groups. All were initially in normal sinus rhythm and without evidence of congestive heart failure. Supraventricular arrhythmias occurred in 17 of 66 controls and in only three of 54 digitalized patients (P less than 0.01). There was no evidence of digitals toxicity. Based on this evidence we recommend prophylactic digitalization for patients having aortocoronary bypass operations.

  15. Monsanto may bypass NIH in microbe test.

    Science.gov (United States)

    Sun, Marjorie

    1985-01-11

    The Monsanto Company is planning to ask the Environmental Protection Agency for clearance to field test a genetically engineered microbial pesticide, bypassing the traditional approval process of the National Institutes of Health. Although only federally funded institutions are required to obtain NIH approval for genetic engineering tests, Monsanto is the first company to bypass the NIH regulatory process, which has become mired in a lawsuit brought by Jeremy Rifkin.

  16. Bypass diode for a solar cell

    Science.gov (United States)

    Rim, Seung Bum; Kim, Taeseok; Smith, David D.; Cousins, Peter J.

    2012-03-13

    Bypass diodes for solar cells are described. In one embodiment, a bypass diode for a solar cell includes a substrate of the solar cell. A first conductive region is disposed above the substrate, the first conductive region of a first conductivity type. A second conductive region is disposed on the first conductive region, the second conductive region of a second conductivity type opposite the first conductivity type.

  17. Acute effects of the sigma-2 receptor agonist siramesine on lysosomal and extra-lysosomal proteolytic systems in lens epithelial cells

    OpenAIRE

    Jonhede, S.; Petersen, A; Zetterberg, M.; Karlsson, J-O

    2010-01-01

    Purpose The aim of the present study was to examine the effects of the sigma-2 receptor agonist, siramesine, on morphology, growth, cell death, lysosomal function, and effects on extra-lysosomal proteolytic systems in human lens epithelial cells. Methods Human lens epithelial cells in culture were exposed to siramesine and examined for morphological changes using Nomarski optics or calcein. Lysosomes were evaluated using acridine orange and Magic Red (RR-cresyl violet). Nuclear morphology was...

  18. An experimental study of nerve bypass graft

    Institute of Scientific and Technical Information of China (English)

    XU Jie; LI Xue-shi

    2008-01-01

    Objective: To study the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity. Methods: A sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained. Results: Nerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s±5.83 m/s vs. 54.88 m/s±4.79m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself. Conclusion: Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

  19. Autophagic flux promotes cisplatin resistance in human ovarian carcinoma cells through ATP-mediated lysosomal function.

    Science.gov (United States)

    Ma, Liwei; Xu, Ye; Su, Jing; Yu, Huimei; Kang, Jinsong; Li, Hongyan; Li, Xiaoning; Xie, Qi; Yu, Chunyan; Sun, Liankun; Li, Yang

    2015-11-01

    Lysosomes are involved in promoting resistance of cancer cells to chemotherapeutic agents. However, the mechanisms underlying lysosomal influence of cisplatin resistance in ovarian cancer remain incompletely understood. We report that, compared with cisplatin-sensitive SKOV3 cells, autophagy increases in cisplatin-resistant SKOV3/DDP cells treated with cisplatin. Inhibition of early-stage autophagy enhanced cisplatin-mediated cytotoxicity in SKOV3/DDP cells, but autophagy inhibition at a later stage by disturbing autophagosome-lysosome fusion is more effective. Notably, SKOV3/DDP cells contained more lysosomes than cisplatin-sensitive SKOV3 cells. Abundant lysosomes and lysosomal cathepsin D activity were required for continued autolysosomal degradation and maintenance of autophagic flux in SKOV3/DDP cells. Furthermore, SKOV3/DDP cells contain abundant lysosomal ATP required for lysosomal function, and inhibition of lysosomal ATP accumulation impaired lysosomal function and blocked autophagic flux. Therefore, our findings suggest that lysosomes at least partially contribute to cisplatin resistance in ovarian cancer cells through their role in cisplatin-induced autophagic processes, and provide insight into the mechanism of cisplatin resistance in tumors.

  20. The Role of Oxidized Cholesterol in Diabetes-Induced Lysosomal Dysfunction in the Brain.

    Science.gov (United States)

    Sims-Robinson, Catrina; Bakeman, Anna; Rosko, Andrew; Glasser, Rebecca; Feldman, Eva L

    2016-05-01

    Abnormalities in lysosomal function have been reported in diabetes, aging, and age-related degenerative diseases. These lysosomal abnormalities are an early manifestation of neurodegenerative diseases and often precede the onset of clinical symptoms such as learning and memory deficits; however, the mechanism underlying lysosomal dysfunction is not known. In the current study, we investigated the mechanism underlying lysosomal dysfunction in the cortex and hippocampi, key structures involved in learning and memory, of a type 2 diabetes (T2D) mouse model, the leptin receptor deficient db/db mouse. We demonstrate for the first time that diabetes leads to destabilization of lysosomes as well as alterations in the protein expression, activity, and/or trafficking of two lysosomal enzymes, hexosaminidase A and cathepsin D, in the hippocampus of db/db mice. Pioglitazone, a thiazolidinedione (TZD) commonly used in the treatment of diabetes due to its ability to improve insulin sensitivity and reverse hyperglycemia, was ineffective in reversing the diabetes-induced changes on lysosomal enzymes. Our previous work revealed that pioglitazone does not reverse hypercholesterolemia; thus, we investigated whether cholesterol plays a role in diabetes-induced lysosomal changes. In vitro, cholesterol promoted the destabilization of lysosomes, suggesting that lysosomal-related changes associated with diabetes are due to elevated levels of cholesterol. Since lysosome dysfunction precedes neurodegeneration, cognitive deficits, and Alzheimer's disease neuropathology, our results may provide a potential mechanism that links diabetes with complications of the central nervous system.

  1. Myelin lesions associated with lysosomal and peroxisomal disorders.

    Science.gov (United States)

    Faust, Phyllis L; Kaye, Edward M; Powers, James M

    2010-09-01

    Abnormalities of myelin are common in lysosomal and peroxisomal disorders. Most display a primary loss of myelin in which the myelin sheath and/or oligodendrocytes are selectively targeted by diverse pathogenetic processes. The most severe and, hence, clinically relevant are heritable diseases predominantly of infants and children, the leukodystrophies: metachromatic, globoid cell (Krabbe disease) and adreno-leukodystrophy. Our still limited understanding of these diseases has derived from multiple sources: originally, neurological-neuropathologic-neurochemical correlative studies of the natural disease in humans or other mammals, which has been enhanced by more sophisticated and contemporary techniques of cell and molecular biology. Transgenic mouse models seem to be the most promising methodology, allowing the examination of the cellular role of lysosomes and peroxisomes for formation and maintenance of both myelin and axons, and providing initial platforms to evaluate therapies. Treatment options are woefully inadequate and in their nascent stages, but still inspire some hope for the future.

  2. Targeting Androgen Receptor by Lysosomal Degradation in Prostate Cancer

    Science.gov (United States)

    2014-09-01

    were done as described.13 Protein Sample Preparation and Mass Spectrometry Tandem Affinity Purification of FLAG-His-EWS-Fli-1- Interacting Proteins . Forty...incubated with Ni-NTA agarose (Qiagen), FLAG-His-EWS-Fli-1 and its interacting proteins were collected by centrifugation, washed three times with TN buffer...the lysosome fraction was loaded at 100x compared to the input. ■ RESULTS AND DISCUSSION Proteomic Analysis of the EWS-Fli-1- Interacting Proteins To

  3. Recent advances in gene therapy for lysosomal storage disorders.

    Science.gov (United States)

    Rastall, David Pw; Amalfitano, Andrea

    2015-01-01

    Lysosomal storage disorders (LSDs) are a group of genetic diseases that result in metabolic derangements of the lysosome. Most LSDs are due to the genetic absence of a single catabolic enzyme, causing accumulation of the enzyme's substrate within the lysosome. Over time, tissue-specific substrate accumulations result in a spectrum of symptoms and disabilities that vary by LSD. LSDs are promising targets for gene therapy because delivery of a single gene into a small percentage of the appropriate target cells may be sufficient to impact the clinical course of the disease. Recently, there have been several significant advancements in the potential for gene therapy of these disorders, including the first human trials. Future clinical trials will build upon these initial attempts, with an improved understanding of immune system responses to gene therapy, the obstacle that the blood-brain barrier poses for neuropathic LSDs, as well other biological barriers that, when overcome, may facilitate gene therapy for LSDs. In this manuscript, we will highlight the recent innovations in gene therapy for LSDs and discuss the clinical limitations that remain to be overcome, with the goal of fostering an understanding and further development of this important field.

  4. Discriminating lysosomal membrane protein types using dynamic neural network.

    Science.gov (United States)

    Tripathi, Vijay; Gupta, Dwijendra Kumar

    2014-01-01

    This work presents a dynamic artificial neural network methodology, which classifies the proteins into their classes from their sequences alone: the lysosomal membrane protein classes and the various other membranes protein classes. In this paper, neural networks-based lysosomal-associated membrane protein type prediction system is proposed. Different protein sequence representations are fused to extract the features of a protein sequence, which includes seven feature sets; amino acid (AA) composition, sequence length, hydrophobic group, electronic group, sum of hydrophobicity, R-group, and dipeptide composition. To reduce the dimensionality of the large feature vector, we applied the principal component analysis. The probabilistic neural network, generalized regression neural network, and Elman regression neural network (RNN) are used as classifiers and compared with layer recurrent network (LRN), a dynamic network. The dynamic networks have memory, i.e. its output depends not only on the input but the previous outputs also. Thus, the accuracy of LRN classifier among all other artificial neural networks comes out to be the highest. The overall accuracy of jackknife cross-validation is 93.2% for the data-set. These predicted results suggest that the method can be effectively applied to discriminate lysosomal associated membrane proteins from other membrane proteins (Type-I, Outer membrane proteins, GPI-Anchored) and Globular proteins, and it also indicates that the protein sequence representation can better reflect the core feature of membrane proteins than the classical AA composition.

  5. Vamp-7 Mediates Vesicular Transport from Endosomes to Lysosomes

    Science.gov (United States)

    Advani, Raj J.; Yang, Bin; Prekeris, Rytis; Lee, Kelly C.; Klumperman, Judith; Scheller, Richard H.

    1999-01-01

    A more complete picture of the molecules that are critical for the organization of membrane compartments is beginning to emerge through the characterization of proteins in the vesicle-associated membrane protein (also called synaptobrevin) family of membrane trafficking proteins. To better understand the mechanisms of membrane trafficking within the endocytic pathway, we generated a series of monoclonal and polyclonal antibodies against the cytoplasmic domain of vesicle-associated membrane protein 7 (VAMP-7). The antibodies recognize a 25-kD membrane-associated protein in multiple tissues and cell lines. Immunohistochemical analysis reveals colocalization with a marker of late endosomes and lysosomes, lysosome-associated membrane protein 1 (LAMP-1), but not with other membrane markers, including p115 and transferrin receptor. Treatment with nocodozole or brefeldin A does not disrupt the colocalization of VAMP-7 and LAMP-1. Immunoelectron microscopy analysis shows that VAMP-7 is most concentrated in the trans-Golgi network region of the cell as well as late endosomes and transport vesicles that do not contain the mannose-6 phosphate receptor. In streptolysin- O–permeabilized cells, antibodies against VAMP-7 inhibit the breakdown of epidermal growth factor but not the recycling of transferrin. These data are consistent with a role for VAMP-7 in the vesicular transport of proteins from the early endosome to the lysosome. PMID:10459012

  6. MCOLN1 is a ROS sensor in lysosomes that regulates autophagy.

    Science.gov (United States)

    Zhang, Xiaoli; Cheng, Xiping; Yu, Lu; Yang, Junsheng; Calvo, Raul; Patnaik, Samarjit; Hu, Xin; Gao, Qiong; Yang, Meimei; Lawas, Maria; Delling, Markus; Marugan, Juan; Ferrer, Marc; Xu, Haoxing

    2016-06-30

    Cellular stresses trigger autophagy to remove damaged macromolecules and organelles. Lysosomes 'host' multiple stress-sensing mechanisms that trigger the coordinated biogenesis of autophagosomes and lysosomes. For example, transcription factor (TF)EB, which regulates autophagy and lysosome biogenesis, is activated following the inhibition of mTOR, a lysosome-localized nutrient sensor. Here we show that reactive oxygen species (ROS) activate TFEB via a lysosomal Ca(2+)-dependent mechanism independent of mTOR. Exogenous oxidants or increasing mitochondrial ROS levels directly and specifically activate lysosomal TRPML1 channels, inducing lysosomal Ca(2+) release. This activation triggers calcineurin-dependent TFEB-nuclear translocation, autophagy induction and lysosome biogenesis. When TRPML1 is genetically inactivated or pharmacologically inhibited, clearance of damaged mitochondria and removal of excess ROS are blocked. Furthermore, TRPML1's ROS sensitivity is specifically required for lysosome adaptation to mitochondrial damage. Hence, TRPML1 is a ROS sensor localized on the lysosomal membrane that orchestrates an autophagy-dependent negative-feedback programme to mitigate oxidative stress in the cell.

  7. Syntaxin 7 and VAMP-7 are Soluble N-Ethylmaleimide–sensitive Factor Attachment Protein Receptors Required for Late Endosome–Lysosome and Homotypic Lysosome Fusion in Alveolar Macrophages

    Science.gov (United States)

    Ward, Diane McVey; Pevsner, Jonathan; Scullion, Matthew A.; Vaughn, Michael; Kaplan, Jerry

    2000-01-01

    Endocytosis in alveolar macrophages can be reversibly inhibited, permitting the isolation of endocytic vesicles at defined stages of maturation. Using an in vitro fusion assay, we determined that each isolated endosome population was capable of homotypic fusion. All vesicle populations were also capable of heterotypic fusion in a temporally specific manner; early endosomes, isolated 4 min after internalization, could fuse with endosomes isolated 8 min after internalization but not with 12-min endosomes or lysosomes. Lysosomes fuse with 12-min endosomes but not with earlier endosomes. Using homogenous populations of endosomes, we have identified Syntaxin 7 as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) required for late endosome–lysosome and homotypic lysosome fusion in vitro. A bacterially expressed human Syntaxin 7 lacking the transmembrane domain inhibited homotypic late endosome and lysosome fusion as well as heterotypic late endosome–lysosome fusion. Affinity-purified antibodies directed against Syntaxin 7 also inhibited lysosome fusion in vitro but had no affect on homotypic early endosome fusion. Previous work suggested that human VAMP-7 (vesicle-associated membrane protein-7) was a SNARE required for late endosome–lysosome fusion. A bacterially expressed human VAMP-7 lacking the transmembrane domain inhibited both late endosome–lysosome fusion and homotypic lysosome fusion in vitro. These studies indicate that: 1) fusion along the endocytic pathway is a highly regulated process, and 2) two SNARE molecules, Syntaxin 7 and human VAMP-7, are involved in fusion of vesicles in the late endocytic pathway in alveolar macrophages. PMID:10888671

  8. [Simplified laparoscopic gastric bypass. Initial experience].

    Science.gov (United States)

    Hernández-Miguelena, Luis; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Ríos-Cruz, Daniel; Marín-Domínguez, Raúl; Castillo-González, Armando

    2014-01-01

    Antecedentes: la cirugía de la obesidad comprende diversos procedimientos gastrointestinales. El bypass gástrico en Y de Roux es el prototipo de los procedimientos mixtos y el más practicado en el mundo en sus diversas variedades. Una técnica similar y novedosa es la adoptada por Cardoso-Ramos y Galvao denominada "bypass simplificado" que rápidamente se aceptó por la mayor facilidad y resultados muy parecidos a la técnica convencional. Objetivo: describir los resultados a un año del bypass gástrico simplificado para el tratamiento de la obesidad mórbida. Material y métodos: estudio retrospectivo y descriptivo de todos los pacientes a quienes se realizó bypass gástrico de enero de 2008 a julio de 2012, en la clínica de obesidad de un hospital privado de la Ciudad de México. Resultados: se estudiaron 90 pacientes con diagnóstico de obesidad mórbida, con límites de edad de 18 y 65 años, operados para bypass gástrico simplificado. En 10% de los pacientes hubo complicaciones, las más frecuentes fueron: hemorragia y hernia interna. Durante el periodo de estudio la mortalidad fue de 0%. La pérdida de peso promedio a los 12 meses fue de 72.7%. Conclusión: el bypass gástrico simplificado laparoscópico es una cirugía segura, con buenos resultados a mediano plazo, y con una pérdida del exceso de peso adecuada en 71% de los casos.

  9. Analgesic Treatment in Laparoscopic Gastric Bypass Surgery

    DEFF Research Database (Denmark)

    Andersen, Lars P H; Werner, Mads U; Rosenberg, Jacob

    2014-01-01

    This review aimed to present an overview of the randomized controlled trials investigating analgesic regimens used in laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Literature search was performed in PubMed and EMBASE databases in August 2013 in accordance to PRISMA guidelines. The litera......This review aimed to present an overview of the randomized controlled trials investigating analgesic regimens used in laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Literature search was performed in PubMed and EMBASE databases in August 2013 in accordance to PRISMA guidelines...

  10. Doppler spectral characteristics of infrainguinal vein bypasses

    DEFF Research Database (Denmark)

    Nielsen, Tina G; von Jessen, F; Sillesen, H;

    1993-01-01

    With the aim of assessing the velocity profile of femoropopliteal and femorocrural vein bypasses, 128 patients undergoing infrainguinal vein bypass surgery entered a postoperative Duplex surveillance protocol, which included clinical assessment and Duplex scanning, using Doppler spectral analysis...... of arteriovenous fistulas the initially antegrade diastolic velocity was replaced by a retrograde flow within 3 months, whereas a forward flow in diastole was sustained in grafts with patent fistulas. Abnormal Duplex findings in 31 patients led to angiography and revision in 13 cases. Four revised grafts failed...

  11. Variable volume combustor with an air bypass system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Ostebee, Heath Michael; Keener, Christopher Paul

    2017-02-07

    The present application provides a combustor for use with flow of fuel and a flow of air in a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles positioned within a liner and an air bypass system position about the liner. The air bypass system variably allows a bypass portion of the flow of air to bypass the micro-mixer fuel nozzles.

  12. 46 CFR 154.550 - Excess flow valve: Bypass.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Excess flow valve: Bypass. 154.550 Section 154.550... and Process Piping Systems § 154.550 Excess flow valve: Bypass. If the excess flow valve allowed under § 154.532(b) has a bypass, the bypass must be of 1.0 mm (0.0394 in.) or less in diameter. Cargo Hose...

  13. Cathepsin B modulates lysosomal biogenesis and host defense against Francisella novicida infection.

    Science.gov (United States)

    Qi, Xiaopeng; Man, Si Ming; Malireddi, R K Subbarao; Karki, Rajendra; Lupfer, Christopher; Gurung, Prajwal; Neale, Geoffrey; Guy, Clifford S; Lamkanfi, Mohamed; Kanneganti, Thirumala-Devi

    2016-09-19

    Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic, and degenerative diseases in humans. In this study, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida Genetic deletion or pharmacological inhibition of cathepsin B down-regulated mechanistic target of rapamycin activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via transcription factor EB, which increased lysosomal biogenesis and activation of autophagy initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome populations and basic recycling functions in the cell.

  14. TFEB and TFE3: Linking Lysosomes to Cellular Adaptation to Stress.

    Science.gov (United States)

    Raben, Nina; Puertollano, Rosa

    2016-10-06

    In recent years, our vision of lysosomes has drastically changed. Formerly considered to be mere degradative compartments, they are now recognized as key players in many cellular processes. The ability of lysosomes to respond to different stimuli revealed a complex and coordinated regulation of lysosomal gene expression. This review discusses the participation of the transcription factors TFEB and TFE3 in the regulation of lysosomal function and biogenesis, as well as the role of the lysosomal pathway in cellular adaptation to a variety of stress conditions, including nutrient deprivation, mitochondrial dysfunction, protein misfolding, and pathogen infection. We also describe how cancer cells make use of TFEB and TFE3 to promote their own survival and highlight the potential of these transcription factors as therapeutic targets for the treatment of neurological and lysosomal diseases.

  15. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood...

  16. Obstructive and enteropathic syndromes after jejunoileal bypass surgery

    Energy Technology Data Exchange (ETDEWEB)

    Karasick, D.; Karasick, S.

    1981-05-15

    Small bowel bypass procedures for morbid obesity have been associated with many postoperative complications. With the use of the Scott procedure, the bypassed or excluded small bowel segment has recently been the focus of 2 syndromes - 'bypass enteritis' and 'defunctioned bowel syndrome'. We describe these postoperative complications and present their significant radiologic features.

  17. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device. 870.3545... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that...

  18. 20 CFR 631.18 - Federal by-pass authority.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Federal by-pass authority. 631.18 Section 631... Procedures § 631.18 Federal by-pass authority. (a) In the event that a State fails to submit a biennial State... Secretary's intent to exercise by-pass authority and an opportunity to request and to receive a...

  19. A TRP Channel in the Lysosome Regulates Large Particle Phagocytosis via Focal Exocytosis

    OpenAIRE

    2013-01-01

    Phagocytosis of large extracellular particles such as apoptotic bodies requires delivery of the intracellular endosomal and lysosomal membranes to form plasmalemmal pseudopods. Here we identified Mucolipin TRP channel 1 (TRPML1) as the key lysosomal Ca2+ channel regulating focal exocytosis and phagosome biogenesis. Both particle ingestion and lysosomal exocytosis are inhibited by synthetic TRPML1 blockers, and are defective in macrophages isolated from TRPML1 knockout mice. Furthermore, TRPML...

  20. Disruption of Lysosome Function Promotes Tumor Growth and Metastasis in Drosophila *

    OpenAIRE

    Chi, Congwu; Zhu, Huanhu; Han,Min; Zhuang, Yuan; Wu, Xiaohui; Xu, Tian

    2010-01-01

    Lysosome function is essential to many physiological processes. It has been suggested that deregulation of lysosome function could contribute to cancer. Through a genetic screen in Drosophila, we have discovered that mutations disrupting lysosomal degradation pathway components contribute to tumor development and progression. Loss-of-function mutations in the Class C vacuolar protein sorting (VPS) gene, deep orange (dor), dramatically promote tumor overgrowth and invasion of the RasV12 cells....

  1. Sub-lethal oxidative stress induces lysosome biogenesis via a lysosomal membrane permeabilization-cathepsin-caspase 3-transcription factor EB-dependent pathway.

    Science.gov (United States)

    Leow, San Min; Chua, Shu Xian Serene; Venkatachalam, Gireedhar; Shen, Liang; Luo, Le; Clement, Marie-Veronique

    2016-12-18

    Here we provide evidence to link sub-lethal oxidative stress to lysosomal biogenesis. Exposure of cells to sub-lethal concentrations of exogenously added hydrogen peroxide resulted in cytosol to nuclear translocation of the Transcription Factor EB (TFEB), the master controller of lysosome biogenesis and function. Nuclear translocation of TFEB was dependent upon the activation of a cathepsin-caspase 3 signaling pathway, downstream of a lysosomal membrane permeabilization and accompanied by a significant increase in lysosome numbers as well as induction of TFEB dependent lysosome-associated genes expression such as Ctsl, Lamp2 and its spliced variant Lamp2a, Neu1and Ctsb and Sqstm1 and Atg9b. The effects of sub-lethal oxidative stress on lysosomal gene expression and biogenesis were rescued upon gene silencing of caspase 3 and TFEB. Notably, caspase 3 activation was not associated with phenotypic hallmarks of apoptosis, evidenced by the absence of caspase 3 substrate cleavage, such as PARP, Lamin A/C or gelsolin. Taken together, these data demonstrate for the first time an unexpected and non-canonical role of a cathepsin-caspase 3 axis in the nuclear translocation of TFEB leading to lysosomes biogenesis under conditions of sub-lethal oxidative stress.

  2. Bypassing BDD Construction for Reliability Analysis

    DEFF Research Database (Denmark)

    Williams, Poul Frederick; Nikolskaia, Macha; Rauzy, Antoine

    2000-01-01

    In this note, we propose a Boolean Expression Diagram (BED)-based algorithm to compute the minimal p-cuts of boolean reliability models such as fault trees. BEDs make it possible to bypass the Binary Decision Diagram (BDD) construction, which is the main cost of fault tree assessment....

  3. Robotically-Assisted Coronary Artery Bypass Grafting

    Directory of Open Access Journals (Sweden)

    Thierry A. Folliguet

    2010-01-01

    Full Text Available Objectives. Robotic surgery enables to perform coronary surgery totally endoscopically. This report describes our experience using the da Vinci system for coronary artery bypass surgery. Methods. Patients requiring single-or-double vessel revascularization were eligible. The procedure was performed without cardiopulmonary bypass on a beating heart. Results. From April 2004 to May 2008, fifty-six patients were enrolled in the study. Twenty-four patients underwent robotic harvesting of the mammary conduit followed by minimal invasive direct coronary artery bypass (MIDCAB, and twenty-three patients had a totally endoscopic coronary artery bypass (TECAB grafting. Nine patients (16% were converted to open techniques. The mean total operating time for TECAB was 372±104 minutes and for MIDCAB was 220±69 minutes. Followup was complete for all patients up to one year. There was one hospital death following MIDCAB and two deaths at follow up. Forty-eight patients had an angiogram or CT scan revealing occlusion or anastomotic stenoses (>50% in 6 patients. Overall permeability was 92%. Conclusions. Robotic surgery can be performed with promising results.

  4. Gastric infarction following gastric bypass surgery

    Science.gov (United States)

    Do, Patrick H; Kang, Young S; Cahill, Peter

    2016-01-01

    Gastric infarction is an extremely rare occurrence owing to the stomach’s extensive vascular supply. We report an unusual case of gastric infarction following gastric bypass surgery. We describe the imaging findings and discuss possible causes of this condition. PMID:27200168

  5. Cephalic veins in coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Licht, P; Jakobsen, Erik; Lerbjerg, G;

    1996-01-01

    Various alternative conduits for aortocoronary bypass grafting have been suggested when the saphenous vein quality is inadequate. During a 10-year period we have used the cephalic vein in 39 patients. Eighteen entered an angiographic follow-up study. A total of 31 arm vein grafts were used with 4...

  6. Reporter assay for endo/lysosomal escape of toxin-based therapeutics.

    Science.gov (United States)

    Gilabert-Oriol, Roger; Thakur, Mayank; von Mallinckrodt, Benedicta; Bhargava, Cheenu; Wiesner, Burkhard; Eichhorst, Jenny; Melzig, Matthias F; Fuchs, Hendrik; Weng, Alexander

    2014-05-22

    Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters-horseradish peroxidase (HRP), Alexa Fluor 488 (Alexa) and ricin A-chain (RTA)-were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates-saporin-HRP, (Alexa)saporin and saporin-KQ-RTA-were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release) or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape) was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of (Alexa)saporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10-1000 nM.

  7. Cathepsin inhibition-induced lysosomal dysfunction enhances pancreatic beta-cell apoptosis in high glucose.

    Science.gov (United States)

    Jung, Minjeong; Lee, Jaemeun; Seo, Hye-Young; Lim, Ji Sun; Kim, Eun-Kyoung

    2015-01-01

    Autophagy is a lysosomal degradative pathway that plays an important role in maintaining cellular homeostasis. We previously showed that the inhibition of autophagy causes pancreatic β-cell apoptosis, suggesting that autophagy is a protective mechanism for the survival of pancreatic β-cells. The current study demonstrates that treatment with inhibitors and knockdown of the lysosomal cysteine proteases such as cathepsins B and L impair autophagy, enhancing the caspase-dependent apoptosis of INS-1 cells and islets upon exposure to high concentration of glucose. Interestingly, treatment with cathepsin B and L inhibitors prevented the proteolytic processing of cathepsins B, D and L, as evidenced by gradual accumulation of the respective pro-forms. Of note, inhibition of aspartic cathepsins had no effect on autophagy and cell viability, suggesting the selective role of cathepsins B and L in the regulation of β-cell autophagy and apoptosis. Lysosomal localization of accumulated pro-cathepsins in the presence of cathepsin B and L inhibitors was verified via immunocytochemistry and lysosomal fractionation. Lysotracker staining indicated that cathepsin B and L inhibitors led to the formation of severely enlarged lysosomes in a time-dependent manner. The abnormal accumulation of pro-cathepsins following treatment with inhibitors of cathepsins B and L suppressed normal lysosomal degradation and the processing of lysosomal enzymes, leading to lysosomal dysfunction. Collectively, our findings suggest that cathepsin defects following the inhibition of cathepsin B and L result in lysosomal dysfunction and consequent cell death in pancreatic β-cells.

  8. hLGDB: a database of human lysosomal genes and their regulation.

    Science.gov (United States)

    Brozzi, Alessandro; Urbanelli, Lorena; Germain, Pierre Luc; Magini, Alessandro; Emiliani, Carla

    2013-01-01

    Lysosomes are cytoplasmic organelles present in almost all eukaryotic cells, which play a fundamental role in key aspects of cellular homeostasis such as membrane repair, autophagy, endocitosis and protein metabolism. The characterization of the genes and enzymes constituting the lysosome represents a central issue to be addressed toward a better understanding of the biology of this organelle. In humans, mutations that cause lysosomal enzyme deficiencies result in >50 different disorders and severe pathologies. So far, many experimental efforts using different methodologies have been carried out to identity lysosomal genes. The Human Lysosome Gene Database (hLGDB) is the first resource that provides a comprehensive and accessible census of the human genes belonging to the lysosomal system. This database was developed by collecting and annotating gene lists from many different sources. References to the studies that have identified each gene are provided together with cross databases gene related information. Special attention has been given to the regulation of the genes through microRNAs and the transcription factor EB. The hLGDB can be easily queried to retrieve, combine and analyze information on different lists of lysosomal genes and their regulation by microRNA (binding sites predicted by five different algorithms). The hLGDB is an open access dynamic project that will permit in the future to collapse in a unique publicly accessible resource all the available biological information about lysosome genes and their regulation. Database URL: http://lysosome.unipg.it/.

  9. Lysosomes serve as a platform for hepatitis A virus particle maturation and nonlytic release.

    Science.gov (United States)

    Seggewiß, Nicole; Paulmann, Dajana; Dotzauer, Andreas

    2016-01-01

    Early studies on hepatitis A virus (HAV) in cell culture demonstrated the inclusion of several viral particles in an intracellular lipid-bilayer membrane. However, the origin of these virus-associated membranes and the mechanism for the non-lytic release of HAV into bile are still unknown. Analyzing the association of this virus with cell organelles, we found that newly synthesized HAV particles accumulate in lysosomal organelles and that lysosomal enzymes are involved in the maturation cleavage of the virion. Furthermore, by inhibiting the processes of fusion of lysosomes with the plasma membrane, we found that the nonlytic release of HAV from infected cells occurs via lysosome-related organelles.

  10. Lipid Storage Disorders Block Lysosomal Trafficking By Inhibiting TRP Channel and Calcium Release

    OpenAIRE

    2012-01-01

    Lysosomal lipid accumulation, defects in membrane trafficking, and altered Ca2+ homeostasis are common features in many lysosomal storage diseases. Mucolipin TRP channel 1 (TRPML1) is the principle Ca2+ channel in the lysosome. Here we show that TRPML1-mediated lysosomal Ca2+ release, measured using a genetically-encoded Ca2+ indicator (GCaMP3) attached directly to TRPML1 and elicited by a potent membrane-permeable synthetic agonist, is dramatically reduced in Niemann-Pick (NP) disease cells....

  11. Reporter Assay for Endo/Lysosomal Escape of Toxin-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Roger Gilabert-Oriol

    2014-05-01

    Full Text Available Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters—horseradish peroxidase (HRP, Alexa Fluor 488 (Alexa and ricin A-chain (RTA—were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates—saporin-HRP, Alexasaporin and saporin-KQ-RTA—were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of Alexasaporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10–1000 nM.

  12. Post-Bypass Extensive Ascites due to Splanchnic Bypass and the Effectiveness of Hyperalimentation Treatment

    Directory of Open Access Journals (Sweden)

    Veysel Temizkan

    2013-04-01

    Full Text Available Reperfusion edema may develop in the early periods of chronic ischemic tissue reperfusion. Reperfusion edema may be represented after the splanchnic bypass with ascites, abdominal distension, and liver and kidney function impairment. In this article, we are reporting the hyperalimentation treatment and its results for the common ascites and hepatorenal syndrome, after a coeliac and superior mesenteric artery bypass. [Arch Clin Exp Surg 2013; 2(2.000: 124-128

  13. Audiometric changes after coronary artery bypass graft

    Directory of Open Access Journals (Sweden)

    Khorsandi M T

    2007-09-01

    Full Text Available Background: Hearing is one of the most significant senses; There fore, any defect can be frightening. The incidence of sever hearing loss following coronary artery bypass surgery has been estimated as one per thousand. This Prospective study carried out to determine hearing effects of coronary artery bypass surgery."nMethods: age, audiometric changes before and after surgery (hearing levels at multiple frequencies, speech reception threshold and speech discrimination score, minimum blood pressure during the operation, and the time on bypass, measured on One hundred consecutive patients who candidate for coronary artery bypass surgery and the results analysed."nResults: One hundred patients completed the tests. Based on hearing changes found on pre- and post-operative tests, the patients were divided into 3 groups: Those with no change (47 patients according to their audiometric results; those with slight changes ≤10 db (43 patients; and those having average deficits of more than 10 db (10 patients. All the patients were male. None of the patients had complete or severe sensorineural hearing loss. The third group had more prolonged pumping duration when compared with the others groups (p=0.002. Furthermore, 90 percent of patients with a sensorineural hearing loss more than 10 db had diabetes mellitus and hyperlipidemia as risk factors."nConclusion: Sudden sensorineural hearing loss is a sequela in patients who undergoing coronary artery bypass surgery; however, it was usually mild and asymptomatic. Pumping time during the operation is a significant factor in occurring of this complication. With proper treatment of underlying diseases and eliminating the risk factors with improvement of our cardiopulmonary pumps we probably can get better hearing results.

  14. Crystal structure of the conserved domain of the DC lysosomal associated membrane protein: implications for the lysosomal glycocalyx

    OpenAIRE

    Wilke Sonja; Krausze Joern; Büssow Konrad

    2012-01-01

    Abstract Background The family of lysosome-associated membrane proteins (LAMP) comprises the multifunctional, ubiquitous LAMP-1 and LAMP-2, and the cell type-specific proteins DC-LAMP (LAMP-3), BAD-LAMP (UNC-46, C20orf103) and macrosialin (CD68). LAMPs have been implicated in a multitude of cellular processes, including phagocytosis, autophagy, lipid transport and aging. LAMP-2 isoform A acts as a receptor in chaperone-mediated autophagy. LAMP-2 deficiency causes the fatal Danon disease. The ...

  15. Noxa couples lysosomal membrane permeabilization and apoptosis during oxidative stress.

    Science.gov (United States)

    Eno, Colins O; Zhao, Guoping; Venkatanarayan, Avinashnarayan; Wang, Bing; Flores, Elsa R; Li, Chi

    2013-12-01

    The exact roles of lysosomal membrane permeabilization (LMP) in oxidative stress-triggered apoptosis are not completely understood. Here, we first studied the temporal relation between LMP and mitochondrial outer membrane permeabilization (MOMP) during the initial stage of apoptosis caused by the oxidative stress inducer H2O2. Despite its essential role in mediating apoptosis, the expression of the BH3-only Bcl-2 protein Noxa was dispensable for LMP. In contrast, MOMP was dependent on Noxa expression and occurred downstream of LMP. When lysosomal membranes were stabilized by the iron-chelating agent desferrioxamine, H2O2-induced increase in DNA damage, Noxa expression, and subsequent apoptosis were abolished by the inhibition of LMP. Importantly, LMP-induced Noxa expression increase was mediated by p53 and seems to be a unique feature of apoptosis caused by oxidative stress. Finally, exogenous iron loading recapitulated the effects of H2O2 on the expression of BH3-only Bcl-2 proteins. Overall, these data reveal a Noxa-mediated signaling pathway that couples LMP with MOMP and ultimate apoptosis during oxidative stress.

  16. Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes.

    Science.gov (United States)

    Cano, Victoria; March, Catalina; Insua, Jose Luis; Aguiló, Nacho; Llobet, Enrique; Moranta, David; Regueiro, Verónica; Brennan, Gerard P; Millán-Lou, Maria Isabel; Martín, Carlos; Garmendia, Junkal; Bengoechea, José A

    2015-11-01

    Klebsiella pneumoniae is an important cause of community-acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K. pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3-kinase (PI3K). Microscopy studies revealed that K. pneumoniae resides within a vacuolar compartment, the Klebsiella-containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV-killed bacteria, the majority of live bacteria did not co-localize with markers of the lysosomal compartment. Our data suggest that K. pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K. pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K-Akt-Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down-regulation of the expression of cps. Altogether, this study proves evidence that K. pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis.

  17. From Lysosomal Storage Diseases to NKT Cell Activation and Back

    Science.gov (United States)

    Pereira, Cátia S.; Ribeiro, Helena; Macedo, M. Fatima

    2017-01-01

    Lysosomal storage diseases (LSDs) are inherited metabolic disorders characterized by the accumulation of different types of substrates in the lysosome. With a multisystemic involvement, LSDs often present a very broad clinical spectrum. In many LSDs, alterations of the immune system were described. Special emphasis was given to Natural Killer T (NKT) cells, a population of lipid-specific T cells that is activated by lipid antigens bound to CD1d (cluster of differentiation 1 d) molecules at the surface of antigen-presenting cells. These cells have important functions in cancer, infection, and autoimmunity and were altered in a variety of LSDs’ mouse models. In some cases, the observed decrease was attributed to defects in either lipid antigen availability, trafficking, processing, or loading in CD1d. Here, we review the current knowledge about NKT cells in the context of LSDs, including the alterations detected, the proposed mechanisms to explain these defects, and the relevance of these findings for disease pathology. Furthermore, the effect of enzyme replacement therapy on NKT cells is also discussed. PMID:28245613

  18. Frustrated phagocytosis on micro-patterned immune complexes to characterize lysosome movements in live macrophages.

    Directory of Open Access Journals (Sweden)

    Arnaud M. Labrousse

    2011-10-01

    Full Text Available Lysosome mobilization is a key cellular process in phagocytes for bactericidal activities and trans-matrix migration. The molecular mechanisms that regulate lysosome mobilization are still poorly known. Lysosomes are hard to track as they move towards phagosomes throughout the cell volume. In order to anticipate cell regions where lysosomes are recruited to, human and RAW264.7 macrophages were seeded on surfaces that were micro-patterned with immune complexes (ICs as 4 µm-side squares. Distances between IC patterns were adapted to optimize cell spreading in order to constrain lysosome movements mostly in 2 dimensions. Fc receptors triggered local frustrated phagocytosis, frustrated phagosomes appeared as rings of F-actin dots around the IC patterns as early as 5 minutes after cells made contact with the substratum. Frustrated phagosomes recruited actin-associated proteins (vinculin, paxillin and gelsolin. The fusion of lysosomes with frustrated phagosomes was shown by the release of beta-hexosaminidase and the recruitment of Lamp-1 to frustrated phagosomes. Lysosomes of RAW264.7 macrophages were labeled with cathepsinD-mCherry to visualize their movements towards frustrated phagosomes. Lysosomes saltatory movements were markedly slowed down compared to cells layered on non-opsonized patterns. In addition, the linearity of the trajectories and the frequency and duration of contacts of lysosomes with frustrated phagosomes were measured.¬¬¬¬¬¬¬¬ Using PP2 we showed that instant velocity, pauses and frequency of lysosome/phagosome contacts were at least in part dependent on Src tyrosine kinases. This experimental set-up is the first step towards deciphering molecular mechanisms which are involved in lysosome movements in the cytoplasm (directionality, docking and fusion using RNA interference, pharmacological inhibition or mutant expression.

  19. Autophagy-lysosomal pathway is involved in lipid degradation in rat liver.

    Science.gov (United States)

    Skop, V; Cahová, M; Papáčková, Z; Páleníčková, E; Daňková, H; Baranowski, M; Zabielski, P; Zdychová, J; Zídková, J; Kazdová, L

    2012-01-01

    We present data supporting the hypothesis that the lysosomal-autophagy pathway is involved in the degradation of intracellular triacylglycerols in the liver. In primary hepatocytes cultivated in the absence of exogenous fatty acids (FFA), both inhibition of autophagy flux (asparagine) or lysosomal activity (chloroquine) decreased secretion of VLDL (very low density lipoproteins) and formation of FFA oxidative products while the stimulation of autophagy by rapamycine increased some of these parameters. Effect of rapamycine was completely abolished by inactivation of lysosomes. Similarly, when autophagic activity was influenced by cultivating the hepatocytes in "starving" (amino-acid poor medium) or "fed" (serum-supplemented medium) conditions, VLDL secretion and FFA oxidation mirrored the changes in autophagy being higher in starvation and lower in fed state. Autophagy inhibition as well as lysosomal inactivation depressed FFA and DAG (diacylglycerol) formation in liver slices in vitro. In vivo, intensity of lysosomal lipid degradation depends on the formation of autophagolysosomes, i.e. structures bringing the substrate for degradation and lysosomal enzymes into contact. We demonstrated that lysosomal lipase (LAL) activity in liver autophagolysosomal fraction was up-regulated in fasting and down-regulated in fed state together with the increased translocation of LAL and LAMP2 proteins from lysosomal pool to this fraction. Changes in autophagy intensity (LC3-II/LC3-I ratio) followed a similar pattern.

  20. The phytoestrogen genistein modulates lysosomal metabolism and transcription factor EB (TFEB) activation.

    Science.gov (United States)

    Moskot, Marta; Montefusco, Sandro; Jakóbkiewicz-Banecka, Joanna; Mozolewski, Paweł; Węgrzyn, Alicja; Di Bernardo, Diego; Węgrzyn, Grzegorz; Medina, Diego L; Ballabio, Andrea; Gabig-Cimińska, Magdalena

    2014-06-13

    Genistein (5,7-dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) has been previously proposed as a potential drug for use in substrate reduction therapy for mucopolysaccharidoses, a group of inherited metabolic diseases caused by mutations leading to inefficient degradation of glycosaminoglycans (GAGs) in lysosomes. It was demonstrated that this isoflavone can cross the blood-brain barrier, making it an especially desirable potential drug for the treatment of neurological symptoms present in most lysosomal storage diseases. So far, no comprehensive genomic analyses have been performed to elucidate the molecular mechanisms underlying the effect elicited by genistein. Therefore, the aim of this work was to identify the genistein-modulated gene network regulating GAG biosynthesis and degradation, taking into consideration the entire lysosomal metabolism. Our analyses identified over 60 genes with known roles in lysosomal biogenesis and/or function whose expression was enhanced by genistein. Moreover, 19 genes whose products are involved in both GAG synthesis and degradation pathways were found to be remarkably differentially regulated by genistein treatment. We found a regulatory network linking genistein-mediated control of transcription factor EB (TFEB) gene expression, TFEB nuclear translocation, and activation of TFEB-dependent lysosome biogenesis to lysosomal metabolism. Our data indicate that the molecular mechanism of genistein action involves not only impairment of GAG synthesis but more importantly lysosomal enhancement via TFEB. These findings contribute to explaining the beneficial effects of genistein in lysosomal storage diseases as well as envisage new therapeutic approaches to treat these devastating diseases.

  1. Protective effects of sinapic acid on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats.

    Science.gov (United States)

    Roy, Subhro Jyoti; Stanely Mainzen Prince, Ponnian

    2012-11-01

    In the pathology of myocardial infarction, lysosomal lipid peroxidation and resulting enzyme release play an important role. We evaluated the protective effects of sinapic acid on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats. Male Wistar rats were treated with sinapic acid (12 mg/kg body weight) orally daily for 10 days and isoproterenol (100 mg/kg body weight) was injected twice at an interval of 24 h (9th and 10th day). Then, lysosomal lipid peroxidation, lysosomal enzymes in serum, heart homogenate, lysosomal fraction and myocardial infarct size were measured. Isoproterenol induced myocardial infarcted rats showed a significant increase in serum creatine kinase-MB and lysosomal lipid peroxidation. The activities of β-glucuronidase, β-galactosidase, cathepsin-B and D were significantly increased in serum, heart and the activities of β-glucuronidase and cathepsin-D were significantly decreased in lysosomal fraction of myocardial infarcted rats. Pre-and-co-treatment with sinapic acid normalized all the biochemical parameters and reduced myocardial infarct size in myocardial infarcted rats. In vitro studies confirmed the free radical scavenging effects of sinapic acid. The possible mechanisms for the observed effects are attributed to sinapic acid's free radical scavenging and membrane stabilizing properties. Thus, sinapic acid has protective effects on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats.

  2. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation.

    Science.gov (United States)

    Chen, Fang; Zhang, Bing; Sun, Yong; Xiong, Zeng-Xing; Peng, Han; Deng, Ze-Yuan; Hu, Jiang-Ning

    2016-04-25

    Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  3. Expression Pattern of Lysosomal Protective Protein/Cathepsin A: Implications for the analysis of hnman galactosialidosis

    NARCIS (Netherlands)

    R.J. Rottier (Robbert)

    1998-01-01

    textabstractThe lysosome represents a well characterized, membrane-contained intracellular digestive system. Iu this important organelle a battery of lysosomal hydro lases and accessory proteins work in concert on the step-wise conversion of macromolecular substrates into small biological building b

  4. Calpains mediate epithelial-cell death during mammary gland involution: mitochondria and lysosomal destabilization.

    Science.gov (United States)

    Arnandis, T; Ferrer-Vicens, I; García-Trevijano, E R; Miralles, V J; García, C; Torres, L; Viña, J R; Zaragozá, R

    2012-09-01

    Our aim was to elucidate the physiological role of calpains (CAPN) in mammary gland involution. Both CAPN-1 and -2 were induced after weaning and its activity increased in isolated mitochondria and lysosomes. CAPN activation within the mitochondria could trigger the release of cytochrome c and other pro-apoptotic factors, whereas in lysosomes it might be essential for tissue remodeling by releasing cathepsins into the cytosol. Immunohistochemical analysis localized CAPNs mainly at the luminal side of alveoli. During weaning, CAPNs translocate to the lysosomes processing membrane proteins. To identify these substrates, lysosomal fractions were treated with recombinant CAPN and cleaved products were identified by 2D-DIGE. The subunit b(2) of the v-type H(+) ATPase is proteolyzed and so is the lysosomal-associated membrane protein 2a (LAMP2a). Both proteins are also cleaved in vivo. Furthermore, LAMP2a cleavage was confirmed in vitro by addition of CAPNs to isolated lysosomes and several CAPN inhibitors prevented it. Finally, in vivo inhibition of CAPN1 in 72-h-weaned mice decreased LAMP2a cleavage. Indeed, calpeptin-treated mice showed a substantial delay in tissue remodeling and involution of the mammary gland. These results suggest that CAPNs are responsible for mitochondrial and lysosomal membrane permeabilization, supporting the idea that lysosomal-mediated cell death is a new hallmark of mammary gland involution.

  5. Lysosomal cholesterol accumulation : driver on the road to inflammation during atherosclerosis and non-alcoholic steatohepatitis

    NARCIS (Netherlands)

    Hendrikx, T.; Walenbergh, S. M. A.; Hofker, M. H.; Shiri-Sverdlov, R.

    2014-01-01

    Many studies show an association between the accumulation of cholesterol inside lysosomes and the progression towards inflammatory disease states that are closely related to obesity. While in the past, the knowledge regarding lysosomal cholesterol accumulation was limited to its association with pla

  6. A TRP channel in the lysosome regulates large particle phagocytosis via focal exocytosis.

    Science.gov (United States)

    Samie, Mohammad; Wang, Xiang; Zhang, Xiaoli; Goschka, Andrew; Li, Xinran; Cheng, Xiping; Gregg, Evan; Azar, Marlene; Zhuo, Yue; Garrity, Abigail G; Gao, Qiong; Slaugenhaupt, Susan; Pickel, Jim; Zolov, Sergey N; Weisman, Lois S; Lenk, Guy M; Titus, Steve; Bryant-Genevier, Marthe; Southall, Noel; Juan, Marugan; Ferrer, Marc; Xu, Haoxing

    2013-09-16

    Phagocytosis of large extracellular particles such as apoptotic bodies requires delivery of the intracellular endosomal and lysosomal membranes to form plasmalemmal pseudopods. Here, we identified mucolipin TRP channel 1 (TRPML1) as the key lysosomal Ca2+ channel regulating focal exocytosis and phagosome biogenesis. Both particle ingestion and lysosomal exocytosis are inhibited by synthetic TRPML1 blockers and are defective in macrophages isolated from TRPML1 knockout mice. Furthermore, TRPML1 overexpression and TRPML1 agonists facilitate both lysosomal exocytosis and particle uptake. Using time-lapse confocal imaging and direct patch clamping of phagosomal membranes, we found that particle binding induces lysosomal PI(3,5)P2 elevation to trigger TRPML1-mediated lysosomal Ca2+ release specifically at the site of uptake, rapidly delivering TRPML1-resident lysosomal membranes to nascent phagosomes via lysosomal exocytosis. Thus phagocytic ingestion of large particles activates a phosphoinositide- and Ca2+-dependent exocytosis pathway to provide membranes necessary for pseudopod extension, leading to clearance of senescent and apoptotic cells in vivo.

  7. Ubiquitin trafficking to the lysosome: keeping the house tidy and getting rid of unwanted guests.

    Science.gov (United States)

    Purdy, Georgiana E; Russell, David G

    2007-01-01

    Bacterial killing by autophagic delivery to the lysosomal compartment has been shown for Mycobacteria, Streptococcus, Shigella, Legionella and Salmonella, indicating an important role for this conserved trafficking pathway for the control of intracellular bacterial pathogens.(1-5) In a recent study we found that solubilized lysosomes isolated from bone marrow-derived macrophages had potent antibacterial properties against M. tuberculosis and M. smegmatis that were associated with ubiquitin and ubiquitin-derived peptides. We propose that ubiquitinated proteins are delivered to the lysosomal compartment, where degradation by lysosomal proteinases generates ubiquitin-derived peptides with antimycobacterial properties. This surprising finding provokes a number of questions regarding the nature and trafficking of ubiquitin and ubiquitin-modified proteins in mammalian cells. We discuss the possible role(s) that the multivesicular body (MVB), the late endosome and the autophagosome may play in trafficking of ubiquitinated proteins to the lysosome.

  8. Power turbine bypass for improved compression braking

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, R.M.; Lutz, T.P.; Stang, J.

    1992-06-09

    This patent describes a turbocompound engine having a power turbine bypass control. It comprises an internal combustion engine having a crankshaft, an intake manifold and an exhaust manifold; turbocharger means connected with the intake and exhaust manifolds for converting exhaust gas energy into mechanical energy for boosting intake air pressure; power turbine means for producing mechanical energy from energy remaining in the exhaust gases exiting the first turbine.

  9. Coronary artery bypass grafting for Kawasaki disease

    Institute of Scientific and Technical Information of China (English)

    GUO Hong-wei; CHANG Qian; XU Jian-ping; SONG Yun-hu; SUN Han-song; HU Sheng-shou

    2010-01-01

    Background Kawasaki disease (KD) is the leading cause of pediatric ischemic heart disease. The incidence of serious coronary sequelae is low and about 2%-3% of patients with KD, but once myocardial infarction occurs in children, the mortality is quite high and 22% at the first infarction.This study aimed to evaluate the efficacy of coronary artery bypass grafting (CABG) in patients with KD.Methods Eight patients with a history of KD underwent CABG between October 1997 and July 2005. The number of bypass grafts placed was 2 to 4 per patient (mean 2.5±0.8). Various bypass grafts were used in patients, i.e. the left internal mammary artery (LIMA) in 3 patients, bilateral internal mammary artery (IMA) in 2 patients, LIMA plus gastroepiploic artery (GEA) in 1 patient and total saphenous vein grafts (SVGs) in 2 patients. The combined procedures included ventricular aneurysmectomy in 1 patient, mitral valve plasty in 1 and right coronary aneurysmectomy in 1. One patient was not able to wean from cardiopulmonary bypass (CPB), after being supported with intra-aortic balloon pump (IABP), the patient was weaned from CPB successfully.Results One patient died of low cardiac output syndrome and acute renal failure 19 days after operation. Other patients recovered and were discharged uneventfully. During the follow-up that ranged from 3 to 57 months (mean 27 months),clincal angina disappeared or improved. Cardiac function was in Class Ⅰ-Ⅱ (NYHA).Conclusion CABG is a safe and effective procedure for Kawasaki coronary artery disease. However long-term results need to be followed up.

  10. Bypass systems for shared outlets. Bypass-systemen voor gemeenschappelijke afvoersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Dijkhof, W.; Huijzer, E.L.; Beltman, H.A.

    1993-05-01

    In stacked buildings large pressure differences can occur when appliances with individual air supply pipes are connected to a communal outlet. This can be prevented by using a so-called bypass system, which couples the air supply pipe directly to the combustion gases outlet. In case of overpressure on the air supply of an appliance, air will be transported to the combustion gases outlet around the appliance. Descriptions are given of two GASTEC-developed indoor systems: a mechanical bypass system and an aerodynamic bypass system. The aerodynamic system has been optimized for a retrofitting boiler project in Assen, Netherlands. In this project a communal heating system has been replaced by individual central heating boilers. The appliance used was a high-efficiency boiler, the NEFIT Turbo 21. The disadvantage of the mechanical bypass system is one of the moving parts: the valve, which is too sensitive for pollution and failures. Large pressure difference reductions are possible by means of the aerodynamic bypass system. Recirculation can be prevented by high-speed injection of the combustion gases in the combustion gases outlet. 13 figs., 26 tabs., 2 appendices, 2 refs.

  11. Patient's Perception About Coronary Artery Bypass Grafting

    Directory of Open Access Journals (Sweden)

    Kelminda Maria Bulhões Mendonça

    2015-10-01

    Full Text Available ABSTRACT OBJECTIVE: The diagnosis of coronary artery disease referred for heart surgery has an important psychological component. The purpose of this study was to access the difficulties experienced by individuals awaiting coronary artery bypass grafting and to determine strategies that facilitate adaptation to a new lifestyle, modified by the disease. METHODS: A qualitative, exploratory study involving patients admitted to a university teaching hospital in the city of Salvador, Bahia, Brazil, awaiting coronary artery bypass grafting. Semi-structured interviews were performed in accordance with a previously defined script based on the study objective. Each transcription was read in its entirety to verify the representativeness, homogeneity and pertinence of the data obtained (pre-analysis, followed by separation of categories of analysis. RESULTS: The descriptions of this study show that patients admitted to the completion of coronary artery bypass grafting experience a wide range of psychological difficulties, considering that surgery acquires interpretations that vary according to individuals' subjectivity. The patients recognized the benefit of being able to discuss their feelings as a means of diminishing their fear and anxiety. CONCLUSION: Helping patients find resources to confront more positively the daily hospitalization is an important aspect for the health care professionals who assist them. This goal can be achieved through modification of the biomedical model of care for a biopsychosocial view. The investment of time and attention is of fundamental importance and aims to overcome existing deficiencies that interfere with the outcome of patients after cardiac surgery.

  12. Atypical complications of gastric bypass surgery

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Myrosia T. [University of Chicago, Department of Radiology, 5841 S. Maryland Avenue, MC 2026, Chicago, IL 60637 (United States)]. E-mail: mmitchell@radiology.bsd.uchicago.edu; Pizzitola, Victor J. [University of Chicago, Department of Radiology, 5841 S. Maryland Avenue, MC 2026, Chicago, IL 60637 (United States); Knuttinen, M-Grace [University of Chicago, Department of Radiology, 5841 S. Maryland Avenue, MC 2026, Chicago, IL 60637 (United States); Robinson, Tiffany [University of Chicago, Department of Internal Medicine, 5841 S. Maryland Avenue, MC 2026, Chicago, IL 60637 (United States); Gasparaitis, Arunas E. [University of Chicago, Department of Radiology, 5841 S. Maryland Avenue, MC 2026, Chicago, IL 60637 (United States)

    2005-03-01

    Although gastric bypass surgery continues to grow in popularity for weight loss and weight maintenance in the morbidly obese, there has been little attention given to the imaging of complications associated with these surgeries. The purpose of our study is to demonstrate the variety of gastric bypass surgery complications that can be identified radiographically, with attention to the more unusual complications. This study was performed with institutional Internal Review Board approval. We performed a 5-year retrospective review of all patients who had undergone gastric bypass surgery, had complications of the surgery, and had studies performed in our department to image these complications. These studies consisted of contrast fluoroscopy and CT. We identified the more common complications of anastomotic stenoses and anastomotic leaks. We also identified six unusual complications as follow: (1) internal herniation through the small bowel mesentery, (2) internal herniation through the transverse mesocolon, (3) external herniation through the abdominal wall incision, (4) enterocutaneous fistulas, (5) antiperistaltic construction of the Roux-en-Y, and (6) incorrect anstomoses of the Roux limbs resulting in a Roux-en-O configuration. Our findings show that a thorough understanding of expected postoperative bowel configuration is essential in the evaluation of these patients. In addition, fluoroscopic evaluation should assess not only anatomy, but also motility.

  13. Metallothionein-3 regulates lysosomal function in cultured astrocytes under both normal and oxidative conditions.

    Science.gov (United States)

    Lee, Sook-Jeong; Park, Mi-Ha; Kim, Hyun-Jae; Koh, Jae-Young

    2010-08-01

    Cellular zinc plays a key role in lysosomal change and cell death in neurons and astrocytes under oxidative stress. Here, using astrocytes lacking metallothionein-3 (MT3), a potential source of labile zinc in the brain, we studied the role of MT3 in oxidative stress responses. H(2)O(2) induced a large increase in labile zinc in wild-type (WT) astrocytes, but stimulated only a modest rise in MT3-null astrocytes. In addition, H(2)O(2)-induced lysosomal membrane permeabilization (LMP) and cell death were comparably attenuated in MT3-null astrocytes. Expression and glycosylation of Lamp1 (lysosome-associated membrane protein 1) and Lamp2 were increased in MT3-null astrocytes, and the activities of several lysosomal enzymes were significantly reduced, indicating an effect of MT3 on lysosomal components. Consistent with lysosomal dysfunction in MT3-null cells, the level of LC3-II (microtubule-associated protein 1 light chain 3), a marker of early autophagy, was increased by oxidative stress in WT astrocytes, but not in MT3-null cells. Similar changes in Lamp1, LC3, and cathepsin-D were induced by the lysosomal inhibitors bafilomycin A1, chloroquine, and monensin, indicating that lysosomal dysfunction may lie upstream of changes observed in MT3-null astrocytes. Consistent with this idea, lysosomal accumulation of cholesterol and lipofuscin were augmented in MT3-null astrocytes. Similar to the results seen in MT3-null cells, MT3 knockdown by siRNA inhibited oxidative stress-induced increases in zinc and LMP. These results indicate that MT3 may play a key role in normal lysosomal function in cultured astrocytes.

  14. Mild MPP(+) exposure impairs autophagic degradation through a novel lysosomal acidity-independent mechanism.

    Science.gov (United States)

    Miyara, Masatsugu; Kotake, Yaichiro; Tokunaga, Wataru; Sanoh, Seigo; Ohta, Shigeru

    2016-10-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder, but its underlying cause remains unknown. Although recent studies using PD-related neurotoxin MPP(+) suggest autophagy involvement in the pathogenesis of PD, the effect of MPP(+) on autophagic processes under mild exposure, which mimics the slow progressive nature of PD, remains largely unclear. We examined the effect of mild MPP(+) exposure (10 and 200 μM for 48 h), which induces a more slowly developing cell death, on autophagic processes and the mechanistic differences with acute MPP(+) toxicity (2.5 and 5 mM for 24 h). In SH-SY5Y cells, mild MPP(+) exposure predominantly inhibited autophagosome degradation, whereas acute MPP(+) exposure inhibited both autophagosome degradation and basal autophagy. Mild MPP(+) exposure reduced lysosomal hydrolase cathepsin D activity without changing lysosomal acidity, whereas acute exposure decreased lysosomal density. Lysosome biogenesis enhancers trehalose and rapamycin partially alleviated mild MPP(+) exposure induced impaired autophagosome degradation and cell death, but did not prevent the pathogenic response to acute MPP(+) exposure, suggesting irreversible lysosomal damage. We demonstrated impaired autophagic degradation by MPP(+) exposure and mechanistic differences between mild and acute MPP(+) toxicities. Mild MPP(+) toxicity impaired autophagosome degradation through novel lysosomal acidity-independent mechanisms. Sustained mild lysosomal damage may contribute to PD. We examined the effects of MPP(+) on autophagic processes under mild exposure, which mimics the slow progressive nature of Parkinson's disease, in SH-SY5Y cells. This study demonstrated impaired autophagic degradation through a reduction in lysosomal cathepsin D activity without altering lysosomal acidity by mild MPP(+) exposure. Mechanistic differences between acute and mild MPP(+) toxicity were also observed. Sustained mild damage of lysosome may be an underlying cause

  15. Identification of cytoskeleton-associated proteins essential for lysosomal stability and survival of human cancer cells.

    Science.gov (United States)

    Groth-Pedersen, Line; Aits, Sonja; Corcelle-Termeau, Elisabeth; Petersen, Nikolaj H T; Nylandsted, Jesper; Jäättelä, Marja

    2012-01-01

    Microtubule-disturbing drugs inhibit lysosomal trafficking and induce lysosomal membrane permeabilization followed by cathepsin-dependent cell death. To identify specific trafficking-related proteins that control cell survival and lysosomal stability, we screened a molecular motor siRNA library in human MCF7 breast cancer cells. SiRNAs targeting four kinesins (KIF11/Eg5, KIF20A, KIF21A, KIF25), myosin 1G (MYO1G), myosin heavy chain 1 (MYH1) and tropomyosin 2 (TPM2) were identified as effective inducers of non-apoptotic cell death. The cell death induced by KIF11, KIF21A, KIF25, MYH1 or TPM2 siRNAs was preceded by lysosomal membrane permeabilization, and all identified siRNAs induced several changes in the endo-lysosomal compartment, i.e. increased lysosomal volume (KIF11, KIF20A, KIF25, MYO1G, MYH1), increased cysteine cathepsin activity (KIF20A, KIF25), altered lysosomal localization (KIF25, MYH1, TPM2), increased dextran accumulation (KIF20A), or reduced autophagic flux (MYO1G, MYH1). Importantly, all seven siRNAs also killed human cervix cancer (HeLa) and osteosarcoma (U-2-OS) cells and sensitized cancer cells to other lysosome-destabilizing treatments, i.e. photo-oxidation, siramesine, etoposide or cisplatin. Similarly to KIF11 siRNA, the KIF11 inhibitor monastrol induced lysosomal membrane permeabilization and sensitized several cancer cell lines to siramesine. While KIF11 inhibitors are under clinical development as mitotic blockers, our data reveal a new function for KIF11 in controlling lysosomal stability and introduce six other molecular motors as putative cancer drug targets.

  16. Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line

    2013-01-01

    Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome-destab...... multidrug resistance. Their cancer selectivity is associated with transformation-associated reduction in ASM expression and subsequent failure to maintain sphingomyelin hydrolysis during drug exposure. Taken together, these data identify ASM as an attractive target for cancer therapy....

  17. Septins as modulators of endo-lysosomal membrane traffic

    Directory of Open Access Journals (Sweden)

    Kyungyeun Song

    2016-11-01

    Full Text Available Septins constitute a family of GTP-binding proteins, which assemble into non-polar filaments in a nucleotide-dependent manner. These filaments can be recruited to negatively charged membrane surfaces. When associated with membranes septin filaments can act as diffusion barriers, which confine subdomains of distinct biological functions. In addition, they serve scaffolding roles by recruiting cytosolic proteins and other cytoskeletal elements. Septins have been implicated in a large variety of membrane-dependent processes, including cytokinesis, signaling, cell migration, and membrane traffic, and several family members have been implicated in disease. However, surprisingly little is known about the molecular mechanisms underlying their biological functions. This review summarizes evidence in support of regulatory roles of septins during endo-lysosomal sorting, with a particular focus on phosphoinositides, which serve as spatial landmarks guiding septin recruitment to distinct subcellular localizations.

  18. Cloning and expression of mouse legumain, a lysosomal endopeptidase.

    Science.gov (United States)

    Chen, J M; Dando, P M; Stevens, R A; Fortunato, M; Barrett, A J

    1998-01-01

    Legumain, a recently discovered mammalian cysteine endopeptidase, was found in all mouse tissues examined, but was particularly abundant in kidney and placenta. The distribution in subcellular fractions of mouse and rat kidney showed a lysosomal localization, and activity was detectable only after the organelles were disrupted. Nevertheless, ratios of legumain activity to that of cathepsin B differed considerably between mouse tissues. cDNA encoding mouse legumain was cloned and sequenced, the deduced amino acid sequence proving to be 83% identical to that of the human protein [Chen, Dando, Rawlings, Brown, Young, Stevens, Hewitt, Watts and Barrett (1997) J. Biol. Chem. 272, 8090-8098]. Recombinant mouse legumain was expressed in human embryonic kidney 293 cells by use of a vector containing a cytomegalovirus promoter. The recombinant enzyme was partially purified and found to be an asparagine-specific endopeptidase closely similar to naturally occurring pig kidney legumain. PMID:9742219

  19. Dynamic Experimental Study of a Multi—bypass Pulse Tube Refrigerator with Two—bypass Tubes

    Institute of Scientific and Technical Information of China (English)

    YonglinJu; ChaoWang; 等

    1998-01-01

    A dynamic experimental apparatus to measure the instantaneous velocity and pressure in the multibypass pulse tube refrigerator(MPTR) was designed and constructed.Some important experimental results of the instantaneous measurements of the velocity and the pressure in the MPTR with twobypass tubes during actual operation are prsented.The effects of the middle-bypass version on the dynamic pressure and mass flow rate at the cold end of the pulse tube are ev aluated from experimental measurements.DC-flow phenomena are observed in this MPTR.The reasons of the multi-bypass version improved the performance of pulse tube refrigertor are given.

  20. Combined effects of thermal stress and Cd on lysosomal biomarkers and transcription of genes encoding lysosomal enzymes and HSP70 in mussels, Mytilus galloprovincialis.

    Science.gov (United States)

    Izagirre, Urtzi; Errasti, Aitzpea; Bilbao, Eider; Múgica, María; Marigómez, Ionan

    2014-04-01

    In estuaries and coastal areas, intertidal organisms may be subject to thermal stress resulting from global warming, together with pollution. In the present study, the combined effects of thermal stress and exposure to Cd were investigated in the endo-lysosomal system of digestive cells in mussels, Mytilus galloprovincialis. Mussels were maintained for 24h at 18°C and 26°C seawater temperature in absence and presence of 50 μg Cd/L seawater. Cadmium accumulation in digestive gland tissue, lysosomal structural changes and membrane stability were determined. Semi-quantitative PCR was applied to reveal the changes elicited by the different experimental conditions in hexosaminidase (hex), β-glucuronidase (gusb), cathepsin L (ctsl) and heat shock protein 70 (hsp70) gene transcription levels. Thermal stress provoked lysosomal enlargement whilst Cd-exposure led to fusion of lysosomes. Both thermal stress and Cd-exposure caused lysosomal membrane destabilisation. hex, gusb and ctsl genes but not hsp70 gene were transcriptionally up-regulated as a result of thermal stress. In contrast, all the studied genes were transcriptionally down-regulated in response to Cd-exposure. Cd bioaccumulation was comparable at 18°C and 26°C seawater temperatures but interactions between thermal stress and Cd-exposure were remarkable both in lysosomal biomarkers and in gene transcription. hex, gusb and ctsl genes, reacted to elevated temperature in absence of Cd but not in Cd-exposed mussels. Therefore, thermal stress resulting from global warming might influence the use and interpretation of lysosomal biomarkers in marine pollution monitoring programmes and, vice versa, the presence of pollutants may condition the capacity of mussels to respond against thermal stress in a climate change scenario.

  1. COOH-terminal isoleucine of lysosome-associated membrane protein-1 is optimal for its efficient targeting to dense secondary lysosomes.

    Science.gov (United States)

    Akasaki, Kenji; Suenobu, Michihisa; Mukaida, Maki; Michihara, Akihiro; Wada, Ikuo

    2010-12-01

    Lysosome-associated membrane protein-1 (LAMP-1) consists of a highly glycosylated luminal domain, a single-transmembrane domain and a short cytoplasmic tail that possesses a lysosome-targeting signal (GYQTI(382)) at the COOH terminus. It is hypothesized that the COOH-terminal isoleucine, I(382), could be substituted with any other bulky hydrophobic amino acid residue for LAMP-1 to exclusively localize in lysosomes. In order to test this hypothesis, we compared subcellular distribution of four substitution mutants with phenylalanine, leucine, methionine and valine at the COOH-terminus (termed I382F, I382L, I382M and I382V, respectively) with that of wild-type (WT)-LAMP-1. Double-labelled immunofluorescence analyses showed that these substitution mutants were localized as significantly to late endocytic organelles as WT-LAMP-1. However, the quantitative subcellular fractionation study revealed different distribution of WT-LAMP-1 and these four COOH-terminal mutants in late endosomes and dense secondary lysosomes. WT-LAMP-1 was accumulated three to six times more in the dense lysosomal fraction than the four mutants. The level of WT-LAMP-1 in late endosomal fraction was comparable to those of I382F, I382M and I382V. Conversely, I382L in the late endosomal fraction was approximately three times more abundant than WT-LAMP-1. These findings define the presence of isoleucine residue at the COOH-terminus of LAMP-1 as critical in governing its efficient delivery to secondary lysosomes and its ratio of lysosomes to late endosomes.

  2. A marked increase in gastric fluid volume during cardiopulmonary bypass

    OpenAIRE

    2011-01-01

    Major physiological stress occurs during cardiac surgery with cardiopulmonary bypass. This is related to hypothermia and artificial organ perfusion. Thus, serious gastrointestinal complications, particularly upper gastrointestinal bleeding, sometimes follow cardiac surgery. We have compared the antisecretory effects of a preanesthetic H2 antagonist (roxatidine, cardiopulmonary bypass-H2 group, n = 15) and a proton pump inhibitor (rabeprazole, cardiopulmonary bypass-PPI group, n = 15) in patie...

  3. Extra-intracranial standard bypass in the elderly

    DEFF Research Database (Denmark)

    Sandow, Nora; von Weitzel-Mudersbach, Paul; Rosenbaum, Sverre;

    2013-01-01

    Patients with chronic atherosclerotic vessel occlusion and cerebrovascular hemodynamic insufficiency may benefit from extra-intracranial (EC-IC) bypass surgery. Due to demographic changes, an increasing number of elderly patients presents with cerebrovascular hemodynamic insufficiency. So far......, little data for EC-IC bypass surgery in elderly patients suffering occlusive cerebrovascular disease are available. We therefore designed a retrospective study to address the question whether EC-IC bypass is a safe and efficient treatment in a patient cohort ≥70 years....

  4. Action of low-energy monochromatic coherent light on the stability of retinal lysosomes

    Science.gov (United States)

    Metelitsina, Irina P.; Leus, N. F.

    1995-05-01

    The data had been obtained during the experiment in vitro by irradiation of solubilized lysosomal enzymes, retinal homogenates and native lysosomes enabled us to conclude that the laser beam ((lambda) equals 632.8 nm, power density from 0.1 to 15.0 mWt/cm2) acts on the level of membranous structures of lysosomes. During irradiation of rabbits eyes in vitro with an unfocused laser beam (power density on the cornea aur face from 0.01 to 15.0 mWt/cm2 was shown, that low-energy, ranged from 0.01 to 1.0 mWt/cm2 promotes stabilization of lysosomal membranes. Irradiation with laser beam of 8.0 mWt/cm2 and more power induces destabilization of lysosomal membranes. We have also shown that vitamins A and E effecting membranotropic on lysosomes may be corrected by low-energy radiation of helium-neon laser. It is substantiated experimentally that the stabilizing effect of vitamin E may be intensified in case of the combined action of laser radiation on lysosomes. The labilizing effect of vitamin A on membranes of organelles, as was studied, may be weakened by application of laser radiation of low intensities.

  5. Chlamydia species-dependent differences in the growth requirement for lysosomes.

    Directory of Open Access Journals (Sweden)

    Scot P Ouellette

    Full Text Available Genome reduction is a hallmark of obligate intracellular pathogens such as Chlamydia, where adaptation to intracellular growth has resulted in the elimination of genes encoding biosynthetic enzymes. Accordingly, chlamydiae rely heavily on the host cell for nutrients yet their specific source is unclear. Interestingly, chlamydiae grow within a pathogen-defined vacuole that is in close apposition to lysosomes. Metabolically-labeled uninfected host cell proteins were provided as an exogenous nutrient source to chlamydiae-infected cells, and uptake and subsequent labeling of chlamydiae suggested lysosomal degradation as a source of amino acids for the pathogen. Indeed, Bafilomycin A1 (BafA1, an inhibitor of the vacuolar H(+/ATPase that blocks lysosomal acidification and functions, impairs the growth of C. trachomatis and C. pneumoniae, and these effects are especially profound in C. pneumoniae. BafA1 induced the marked accumulation of material within the lysosomal lumen, which was due to the inhibition of proteolytic activities, and this response inhibits chlamydiae rather than changes in lysosomal acidification per se, as cathepsin inhibitors also inhibit the growth of chlamydiae. Finally, the addition of cycloheximide, an inhibitor of eukaryotic protein synthesis, compromises the ability of lysosomal inhibitors to block chlamydial growth, suggesting chlamydiae directly access free amino acids in the host cytosol as a preferred source of these nutrients. Thus, chlamydiae co-opt the functions of lysosomes to acquire essential amino acids.

  6. Eucommia ulmoides cortex, geniposide and aucubin regulate lipotoxicity through the inhibition of lysosomal BAX.

    Science.gov (United States)

    Lee, Geum-Hwa; Lee, Mi-Rin; Lee, Hwa-Young; Kim, Seung Hyun; Kim, Hye-Kyung; Kim, Hyung-Ryong; Chae, Han-Jung

    2014-01-01

    In this study we examined the inhibition of hepatic dyslipidemia by Eucommia ulmoides extract (EUE). Using a screening assay for BAX inhibition we determined that EUE regulates BAX-induced cell death. Among various cell death stimuli tested EUE regulated palmitate-induced cell death, which involves lysosomal BAX translocation. EUE rescued palmitate-induced inhibition of lysosomal V-ATPase, α-galactosidase, α-mannosidase, and acid phosphatase, and this effect was reversed by bafilomycin, a lysosomal V-ATPase inhibitor. The active components of EUE, aucubin and geniposide, showed similar inhibition of palmitate-induced cell death to that of EUE through enhancement of lysosome activity. Consistent with these in vitro findings, EUE inhibited the dyslipidemic condition in a high-fat diet animal model by regulating the lysosomal localization of BAX. This study demonstrates that EUE regulates lipotoxicity through a novel mechanism of enhanced lysosomal activity leading to the regulation of lysosomal BAX activation and cell death. Our findings further indicate that geniposide and aucubin, active components of EUE, may be therapeutic candidates for non-alcoholic fatty liver disease.

  7. Structure Dependence of Lysosomal Transit of Chitosan-Based Polyplexes for Gene Delivery.

    Science.gov (United States)

    Thibault, Marc; Lavertu, Marc; Astolfi, Mélina; Buschmann, Michael D

    2016-10-01

    Chitosan-based polyplexes are known to traffic through lysosomes for a relatively long time, independent of the degree of deacetylation (DDA) and the number average molecular weight (Mn) of the polymer, even though both of these parameters have profound effects on polyplex stability and transfection efficiency. A better understanding of the lysosomal barrier is paramount to the rational design of vectors capable of overcoming obstacles to transgene expression. The aim of the present study was to investigate if lysosomal transit affects chitosan-based polyplex transfection efficiency in a structure-dependent (DDA, Mn) manner. Toward this end, we analyzed the effects of intracellular trafficking modifying agents on transfection efficiency and intracellular vesicular trafficking of polyplexes with different structural properties and stabilities or nucleic acid binding affinity. The use of agents that modify endosome/lysosome acidification and transit processes by distinct mechanisms and their effect on cell viability, polyplex uptake, vesicular trafficking, and transfection efficiency revealed novel and strong chitosan structure-dependent consequences of lysosomal transit. Inhibiting lysosomal transit using chloroquine significantly increased the efficiency of unstable polyplexes, while having minimal effects for polyplexes with intermediate or high stability. In parallel, specifically inhibiting the acidification of vesicles abrogated transfection for all formulations, suggesting that vesicular acidification is essential to promote transfection, most probably by facilitating lysosomal escape. These results provide novel insights into the structure-performance relationship of chitosan-based gene delivery systems.

  8. Involvement of lysosomes in the uptake of macromolecular material by bloodstream forms of Trypanosoma brucei.

    Science.gov (United States)

    Opperdoes, F R; Van Roy, J

    1982-09-01

    To investigate whether the lysosomes of Trypanosoma brucei are capable of uptake of macromolecules after internalization by the cell, we used Triton WR-1339, a non-digestible macromolecular compound, which is known to cause a marked decrease in the density of hepatic lysosomes due to massive intralysosomal storage. Intraperitoneal administration of 0.4 g/kg Triton WR-1339 to rats infected with T. brucei led to the development of a large vacuole in the trypanosomes between nucleus and kinetoplast within 22 h. Higher doses (2 g/kg) led to the disappearance of the trypanosomes from the blood and resulted in permanent cures (greater than 100 days). Lysosomes isolated from the trypanosomes of animals treated with a sub-curative dose showed a decrease in equilibrium density of 0.03 g/cm3 in sucrose gradients. These lysosomes were partly damaged as evidenced by a reduction in latency and an increase in the non-sedimentable part of lysosomal enzymes. We conclude that acid proteinase and alpha-mannosidase-containing organelles of T. brucei take up exogenous macromolecules and must therefore be considered as true lysosomes and that Triton WR-1339 acts in T. brucei as a true lysosomotropic drug. Its trypanocidal action probably results from an interference with lysosomal function.

  9. Lysosomal cholesterol accumulation: driver on the road to inflammation during atherosclerosis and non-alcoholic steatohepatitis.

    Science.gov (United States)

    Hendrikx, T; Walenbergh, S M A; Hofker, M H; Shiri-Sverdlov, R

    2014-05-01

    Many studies show an association between the accumulation of cholesterol inside lysosomes and the progression towards inflammatory disease states that are closely related to obesity. While in the past, the knowledge regarding lysosomal cholesterol accumulation was limited to its association with plaque severity during atherosclerosis, recently, a growing body of evidence indicates a causal link between lysosomal cholesterol accumulation and inflammation. These findings make lysosomal cholesterol accumulation an important target for intervention in metabolic diseases that are characterized by the presence of an inflammatory response. In this review, we aim to show the importance of cholesterol trapping inside lysosomes to the development of inflammation by focusing upon cardiovascular disease and non-alcoholic steatohepatitis (NASH) in particular. We summarize current data supporting the hypothesis that lysosomal cholesterol accumulation plays a key role in the development of inflammation during atherosclerosis and NASH. In addition, potential mechanisms by which disturbed lysosomal function can trigger the inflammatory response, the challenges in improving cholesterol trafficking in macrophages and recent successful research directions will be discussed.

  10. TRPML cation channels regulate the specialized lysosomal compartment of vertebrate B-lymphocytes.

    Science.gov (United States)

    Song, Yumei; Dayalu, Rashmi; Matthews, Sharon A; Scharenberg, Andrew M

    2006-12-01

    B-lymphocytes possess a specialized lysosomal compartment, the regulated transformation of which has been implicated in B-cell antigen presentation. Members of the mucolipin (TRPML) family of cation channels have been implicated in regulated vesicular transport in several tissues, but a role for TRPML function in lymphocyte vesicular transport physiology has not been previously described. To address the role of TRPML proteins in lymphocyte vesicular transport, we analyzed the lysosomal compartment in cultured B-lymphocytes engineered to lack TRPML1 or after expression of N- or C-terminal GFP fusion proteins of TRPML1 or TRPML2. Consistent with previous analyses of lymphocytes derived from human patients with mutations in TRPML1, we were not able to detect abnormalities in the lysosomes of TRPML1-deficient DT40 B-lymphocytes. However, while N-terminal GFP fusions of TRPML2 localized to normal appearing lysosomes, C-terminal GFP fusions of either TRPML1 or TRPML2 acted to antagonize endogenous TRPML function, localizing to large vesicular structures, the histological properties of which were indistinguishable from the enlarged lysosomes observed in affected tissues of TRPML1-deficient humans. Endocytosed B-cell receptors were delivered to these enlarged lysosomes, demonstrating that a TRPML-dependent process is required for normal regulation of the specialized lysosome compartment of vertebrate B-lymphocytes.

  11. Antimicrobial Properties of Lysosomal Enzymes Immobilized on NH₂Functionalized Silica-Encapsulated Magnetite Nanoparticles.

    Science.gov (United States)

    Bang, Seung Hyuck; Sekhon, Simranjeet Singh; Cho, Sung-Jin; Kim, So Jeong; Le, Thai-Hoang; Kim, Pil; Ahn, Ji-Young; Kim, Yang-Hoon; Min, Jiho

    2016-01-01

    The immobilization efficiency, antimicrobial activity and recovery of lysosomal enzymes on NH2 functionalized magnetite nanoparticles have been studied under various conditions. The immobi- lization efficiency depends upon the ratio of the amount of enzyme and magnetite and it shows an increase with magnetite concentration which is due to the presence of amine group at the magnetite surface that leads to a strong attraction. The optimized reaction time to immobilize the lysosomal enzymes on magnetite was determined by using a rolling method. The immobilization efficiency increases with reaction time and reached a plateau after 5 minutes and then remained constant for 10 minutes. However, after 30 minutes the immobilization efficiency decreased to 85%, which is due to the weaker electrostatic interactions between magnetite and detached lysosomal enzymes. The recovery and stability of immobilized lysosomal enzymes has also been studied. The antimicrobial activity was almost 100% but it decreased upon reuse and no activity was observed after its reuse for seven times. The storage stability of lysosomal enzymes as an antimicrobial agent was about 88%, which decreased to 53% after one day and all activity of immobilized lysosomal enzymes was maintained after five days. Thus, the lysosomal enzymes immobilized on magnetite nanoparticles could potentially be used as antimicrobial agents to remove bacteria.

  12. Endovascular exclusion of aortoesophageal fistula after coarctation extraanatomical bypass.

    Science.gov (United States)

    Myers, Patrick O; Gemayel, Gino; Mugnai, Damiano; Murith, Nicolas; Kalangos, Afksendiyos

    2014-07-01

    Extraanatomical bypass has been advocated as the primary technique in adolescents or adults presenting with aortic coarctation. This approach carries significant morbidity, and graft-related complications may be more important in the young patient population. A 52-year-old man who had previously undergone extraanatomical bypass of aortic coarctation was diagnosed with a distal anastomotic pseudoaneurysm and aortoesophageal fistula. This was managed by proximal bypass plugging with an occluder, endovascular exclusion with a stent-graft in the thoracic descending aorta covering the pseudoaneurysm, and coarctation balloon dilation. Aortoesophageal fistula is a late complication observed after extraanatomical bypass for coarctation. This case illustrates this rare complication.

  13. Hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass

    Institute of Scientific and Technical Information of China (English)

    苏肇伉; 周成斌; 张海波; 祝忠群

    2003-01-01

    Objective To study the hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass.Methods Six pregnant ewes underwent fetal cardiopulmonary bypasses with artificial oxygenators and roller pumps for 30 minutes, which maintained the blood gas value at the fetal physiological level. The fetal blood pressure, heart rate, pH value and blood lactate levels were monitored. The levels of catecholamine, cortisol and insulin were measured pre-bypass and then again 30 minutes later. The blood glucose and free fatty acid levels were monitored continuously during the bypass. Fetal hepatic PAS staining was also carried out.Results There were no changes before and during the bypass in fetal blood pressure, heart rate and blood gas. However, pH values decreased and blood lactate levels increased (P<0.05). The fetal catecholamine and cortisol levels increased significantly (P<0.01), while the levels of insulin did not change. The blood glucose and free fatty acid levels increased at the beginning of the bypass (P<0.01), and then gradually slowed down during the bypass. The fetal hepatic PAS staining showed that hepatic glycogen was consumed in large amounts. After 30 minutes of bypass, the fetal lamb would not survive more than 1 hour.Conclusion The fetal lamb has a strong negative reaction to cardiopulmonary bypass.

  14. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner.

    Directory of Open Access Journals (Sweden)

    Christine Burkard

    2014-11-01

    Full Text Available Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs. Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV. Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion.

  15. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner.

    Science.gov (United States)

    Burkard, Christine; Verheije, Monique H; Wicht, Oliver; van Kasteren, Sander I; van Kuppeveld, Frank J; Haagmans, Bart L; Pelkmans, Lucas; Rottier, Peter J M; Bosch, Berend Jan; de Haan, Cornelis A M

    2014-11-01

    Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs). Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV). Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion.

  16. Combined effects of thermal stress and Cd on lysosomal biomarkers and transcription of genes encoding lysosomal enzymes and HSP70 in mussels, Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Izagirre, Urtzi; Errasti, Aitzpea; Bilbao, Eider; Múgica, María; Marigómez, Ionan, E-mail: ionan.marigomez@ehu.es

    2014-04-01

    Highlights: • Thermal stress and Cd caused lysosomal enlargement and membrane destabilisation. • hex, gusb and ctsl but not hsp70 were up-regulated at elevated temperature but down-regulated by Cd. • Thermal stress influenced lysosomal responses to Cd exposure. • The presence of Cd jeopardised responsiveness against thermal stress. - Abstract: In estuaries and coastal areas, intertidal organisms may be subject to thermal stress resulting from global warming, together with pollution. In the present study, the combined effects of thermal stress and exposure to Cd were investigated in the endo-lysosomal system of digestive cells in mussels, Mytilus galloprovincialis. Mussels were maintained for 24 h at 18 °C and 26 °C seawater temperature in absence and presence of 50 μg Cd/L seawater. Cadmium accumulation in digestive gland tissue, lysosomal structural changes and membrane stability were determined. Semi-quantitative PCR was applied to reveal the changes elicited by the different experimental conditions in hexosaminidase (hex), β-glucuronidase (gusb), cathepsin L (ctsl) and heat shock protein 70 (hsp70) gene transcription levels. Thermal stress provoked lysosomal enlargement whilst Cd-exposure led to fusion of lysosomes. Both thermal stress and Cd-exposure caused lysosomal membrane destabilisation. hex, gusb and ctsl genes but not hsp70 gene were transcriptionally up-regulated as a result of thermal stress. In contrast, all the studied genes were transcriptionally down-regulated in response to Cd-exposure. Cd bioaccumulation was comparable at 18 °C and 26 °C seawater temperatures but interactions between thermal stress and Cd-exposure were remarkable both in lysosomal biomarkers and in gene transcription. hex, gusb and ctsl genes, reacted to elevated temperature in absence of Cd but not in Cd-exposed mussels. Therefore, thermal stress resulting from global warming might influence the use and interpretation of lysosomal biomarkers in marine pollution

  17. Lysosomal glycosphingolipid catabolism by acid ceramidase: formation of glycosphingoid bases during deficiency of glycosidases.

    Science.gov (United States)

    Ferraz, Maria J; Marques, André R A; Appelman, Monique D; Verhoek, Marri; Strijland, Anneke; Mirzaian, Mina; Scheij, Saskia; Ouairy, Cécile M; Lahav, Daniel; Wisse, Patrick; Overkleeft, Herman S; Boot, Rolf G; Aerts, Johannes M

    2016-03-01

    Glycosphingoid bases are elevated in inherited lysosomal storage disorders with deficient activity of glycosphingolipid catabolizing glycosidases. We investigated the molecular basis of the formation of glucosylsphingosine and globotriaosylsphingosine during deficiency of glucocerebrosidase (Gaucher disease) and α-galactosidase A (Fabry disease). Independent genetic and pharmacological evidence is presented pointing to an active role of acid ceramidase in both processes through deacylation of lysosomal glycosphingolipids. The potential pathophysiological relevance of elevated glycosphingoid bases generated through this alternative metabolism in patients suffering from lysosomal glycosidase defects is discussed.

  18. On streak breakdown in bypass transition

    Science.gov (United States)

    Schlatter, Philipp; Brandt, Luca; de Lange, H. C.; Henningson, Dan S.

    2008-10-01

    Recent theoretical, numerical, and experimental investigations performed at the Department of Mechanics, KTH Stockholm, and the Department of Mechanical Engineering, Eindhoven University of Technology, are reviewed, and new material is presented to clarify the role of the boundary-layer streaks and their instability with respect to turbulent breakdown in bypass transition in a boundary layer subject to free-stream turbulence. The importance of the streak secondary-instability process for the generation of turbulent spots is clearly shown. The secondary instability manifests itself as a growing wave packet located on the low-speed streak, increasing in amplitude as it is dispersing in the streamwise direction. In particular, qualitative and quantitative data pertaining to temporal sinuous secondary instability of a steady streak, impulse responses both on a parallel and a spatially developing streak, a model problem of bypass transition, and full simulations and experiments of bypass transition itself are collected and compared. In all the flow cases considered, similar characteristics in terms of not only growth rates, group velocity, and wavelengths but also three-dimensional visualizations of the streak breakdown have been found. The wavelength of the instability is about an order of magnitude larger than the local boundary-layer displacement thickness δ∗, the group velocity about 0.8 of the free-stream velocity U∞, and the growth rate on the order of a few percent of U∞/δ∗. The characteristic structures at the breakdown are quasistreamwise vortices, located on the flanks of the low-speed region arranged in a staggered pattern.

  19. Work on the Geneva motorway bypass

    CERN Multimedia

    État de Genève, DCTI, Direction du génie civil

    2006-01-01

    Work on the airport section of the Geneva motorway bypass is continuing and will require the temporary closure of two sliproads allowing traffic to make a U-turn near the airport and the Palexpo exhibition centre. The sliproads on the French and Lausanne sides will be closed until autumn 2006. U-turns will still be possible via clearly marked deviations. For further information: www.autoroute-aeroport.ch We would like to thank you in advance for your understanding. Civil Engineering Department, DCTI, State of Geneva

  20. Bypass variants of Zgornji Hotič

    OpenAIRE

    Vozelj, Nejc

    2014-01-01

    In my Graduation Thesis we presented the solution of road through Zgornji Hotič. This road si daily very busy, because the road is the main connection between the capital of Slovenia and the region Zasavje. The discussed road through Zgornji Hotič is problematic because of dangerous sections of the road and nearby buildings, which lower the transportability and safety of the road. As a solution we have decided to make a bypass between the south-end of Zgornji Hotič and the river Sava. We have...

  1. Hemodynamics Simulation of Stenosed Coronary Bypass Graft

    Institute of Scientific and Technical Information of China (English)

    LIU You-jun; QIAO Aike; DU Jian-jun

    2005-01-01

    By means of FEM, the physiological blood flow in coronary bypass graft is simulated. The stenosis in coronary artery is involved in the graft model,and the deformation of graft end to allow the surgical suture with a smaller diameter coronary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The floor opposed to the anastomosis is an area of high wall stress and high wall stress gradient. Both the toe downstream and the anastomosis bottom floor are prone to intimal hyperplasia.

  2. TRAS principles blight arterial bypass and plasty.

    Directory of Open Access Journals (Sweden)

    Kothari M

    1997-04-01

    Full Text Available A new concept--Tissue Requisitions (Principle I/Relinquishes (Principle II Arterial Supply--of TRAS principles is introduced to help appreciate the failures/successes of modern medicine′s attempts at restoring arterial flow in luminally compromised coronary/carotid fields, an invasive branch rightly called vascular ReRheology, which comprises diagnosing/treating arterial blocks. The technical wizardry of arterial reconstruction (bypass or lumen--restoration (plasty has to reckon with the TRAS principles all the time.

  3. Flow characteristics in narrowed coronary bypass graft

    Science.gov (United States)

    Bernad, S. I.; Bosioc, A.; Bernad, E. S.; Petre, I.; Totorean, A. F.

    2016-06-01

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  4. Indications and Outcomes of Prophylactic and Therapeutic Extracranial-to-intracranial Arterial Bypass for Cerebral Revascularization

    Directory of Open Access Journals (Sweden)

    Emre Gazyakan, MD, MSc

    2015-04-01

    Conclusions: The collaboration of neurosurgeons and plastic surgeons in performing EC-IC bypass can result in excellent outcomes with a high bypass patency rate and few complications, particularly for prophylactic EC-IC bypass.

  5. Roles of CUP-5, the Caenorhabditis elegans orthologue of human TRPML1, in lysosome and gut granule biogenesis

    Directory of Open Access Journals (Sweden)

    Fares Hanna

    2010-06-01

    Full Text Available Abstract Background CUP-5 is a Transient Receptor Potential protein in C. elegans that is the orthologue of mammalian TRPML1. Loss of TRPML1 results in the lysosomal storage disorder Mucolipidosis type IV. Loss of CUP-5 results in embryonic lethality and the accumulation of enlarged yolk granules in developing intestinal cells. The embryonic lethality of cup-5 mutants is rescued by mutations in mrp-4, which is required for gut granule differentiation. Gut granules are intestine-specific lysosome-related organelles that accumulate birefringent material. This link between CUP-5 and gut granules led us to determine the roles of CUP-5 in lysosome and gut granule biogenesis in developing intestinal cells. Results We show that CUP-5 protein localizes to lysosomes, but not to gut granules, in developing intestinal cells. Loss of CUP-5 results in defects in endo-lysosomal transport in developing intestinal cells of C. elegans embryos. This ultimately leads to the appearance of enlarged terminal vacuoles that show defective lysosomal degradation and that have lysosomal and endosomal markers. In contrast, gut granule biogenesis is normal in the absence of CUP-5. Furthermore, loss of CUP-5 does not result in inappropriate fusion or mixing of content between lysosomes and gut granules. Conclusions Using an in vivo model of MLIV, we show that there is a defect in lysosomal transport/biogenesis that is earlier than the presumed function of TRPML1 in terminal lysosomes. Our results indicate that CUP-5 is required for the biogenesis of lysosomes but not of gut granules. Thus, cellular phenotypes in Mucolipidosis type IV are likely not due to defects in lysosome-related organelle biogenesis, but due to progressive defects in lysosomal transport that lead to severe lysosomal dysfunction.

  6. Efficiency Biliopancreatic bypass surgery in bulimia nervosa

    Directory of Open Access Journals (Sweden)

    Yu I Yashkov

    2008-06-01

    Full Text Available A clinical significance in the treatment of bulimia nervosa patients with morbid obesity had already been raised [10, 13], but we did not find publications on the effectiveness of bariatric surgery in these cases. There is also information about the possibility of applying the operation bilio-pancreatic bypass, effective in patients with morbid obesity with uncontrolled eating behavior for the treatment of patients with anorexia BILIM not suffering from morbid obesity. In this article the data of clinical observation of a small sample of patients. As a result, the treatment of these patients found that severe nervous BILIM can be seen as a latent form of morbid obesity. The choice of treatment should depend not only on the initial body weight of the patient, but also on the severity of the nervous BILIM. Unsuccessful attempts at organized-balanced, conservative treatment of patients with severe bulimia nervosa may be considered a variant of surgical treatment, while bilio-pancreatic bypass surgery is considered as the most preferred operation, compared with the installation of the gastric balloon and others. All candidates for surgical treatment of obesity must identify clinical signs of bulimia nervosa, as this may influence the choice of method of operation. Further study of the role of hyperinsulinemia, secretion of ghrelin, leptin, intestinal peptide may contribute to the elucidation of the true causes of bulimia nervosa, probably has a similar origin with morbid obesity.

  7. Previous gastric bypass surgery complicating total thyroidectomy.

    Science.gov (United States)

    Alfonso, Bianca; Jacobson, Adam S; Alon, Eran E; Via, Michael A

    2015-03-01

    Hypocalcemia is a well-known complication of total thyroidectomy. Patients who have previously undergone gastric bypass surgery may be at increased risk of hypocalcemia due to gastrointestinal malabsorption, secondary hyperparathyroidism, and an underlying vitamin D deficiency. We present the case of a 58-year-old woman who underwent a total thyroidectomy for the follicular variant of papillary thyroid carcinoma. Her history included Roux-en-Y gastric bypass surgery. Following the thyroid surgery, she developed postoperative hypocalcemia that required large doses of oral calcium carbonate (7.5 g/day), oral calcitriol (up to 4 μg/day), intravenous calcium gluconate (2.0 g/day), calcium citrate (2.0 g/day), and ergocalciferol (50,000 IU/day). Her serum calcium levels remained normal on this regimen after hospital discharge despite persistent hypoparathyroidism. Bariatric surgery patients who undergo thyroid surgery require aggressive supplementation to maintain normal serum calcium levels. Preoperative supplementation with calcium and vitamin D is strongly recommended.

  8. Enantioselective effects of methamidophos on the coelomocytes lysosomal membrane stability of Eisenia fetida.

    Science.gov (United States)

    Chen, Linhua; Lu, Xianting; Ma, Yun

    2012-12-01

    Many of organophosphorous insecticides are chiral compounds. In this study, the enantioselective effects of organophosphate insecticide methamidophos on the coelomocytes lysosomal membrane stability of earthworm Eisenia fetida were studied: (1) The enantiomers of methamidophos were absolutely separated by high-performance liquid chromatography with a commercial chiral column; (2) The neutral red retention assay was used to judge the lysosomal membrane stability. The results showed that with the concentration increasing, lysosomal membranes have been significantly destroyed by individual stereoisomers and racemate of methamidophos. The neutral red retention times were significantly descended from 76.88 to 29.78 min. Both (+)- and (-)-methamidophos showed more prone to destroy the integrity of the lysosomal membrane than the racemate. However, the different effect between stereoisomers is slight.

  9. Lysosome associated membrane proteins maintain pancreatic acinar cell homeostasis : LAMP-2 deficient mice develop pancreatitis

    NARCIS (Netherlands)

    Mareninova, Olga A; Sendler, Matthias; Malla, Sudarshan Ravi; Yakubov, Iskandar; French, Samuel W; Tokhtaeva, Elmira; Vagin, Olga; Oorschot, Viola; Lüllmann-Rauch, Renate; Blanz, Judith; Dawson, David; Klumperman, Judith; Lerch, Markus M; Mayerle, Julia; Gukovsky, Ilya; Gukovskaya, Anna S

    2015-01-01

    BACKGROUND & AIMS: The pathogenic mechanism of pancreatitis is poorly understood. Recent evidence implicates defective autophagy in pancreatitis responses; however, the pathways mediating impaired autophagy in pancreas remain largely unknown. Here, we investigate the role of lysosome associated memb

  10. Lysosomal acid lipase: At the crossroads of normal and atherogenic cholesterol metabolism

    Directory of Open Access Journals (Sweden)

    Joshua A Dubland

    2015-02-01

    Full Text Available Unregulated cellular uptake of apolipoprotein B-containing lipoproteins in the arterial intima leads to the formation of foam cells in atherosclerosis. Lysosomal acid lipase (LAL plays a crucial role in both lipoprotein lipid catabolism and excess lipid accumulation as it is the primary enzyme that hydrolyzes cholesteryl esters derived from both low density lipoprotein (LDL and modified forms of LDL. Evidence suggests that as atherosclerosis progresses, accumulation of excess free cholesterol in lysosomes leads to impairment of LAL activity, resulting in accumulation of cholesteryl esters in the lysosome as well as the cytosol in foam cells. Impaired metabolism and release of cholesterol from lysosomes can lead to downstream defects in ATP-binding cassette transporter A1 regulation, needed to offload excess cholesterol from plaque foam cells. This review focuses on the role LAL plays in normal cholesterol metabolism and how the associated changes in its enzymatic activity may ultimately contribute to atherosclerosis progression.

  11. Lysosome dysfunction enhances oxidative stress-induced apoptosis through ubiquitinated protein accumulation in Hela cells.

    Science.gov (United States)

    Yu, Chunyan; Huang, Xiaowei; Xu, Ye; Li, Hongyan; Su, Jing; Zhong, Jiateng; Kang, Jinsong; Liu, Yuhe; Sun, Liankun

    2013-01-01

    The role of lysosomal system in oxidative stress-induced apoptosis in cancer cells is not fully understood. Menadione is frequently used as oxidative stress model. It is indicated that menadione could induce autophagy in Hela cells. In the present study, we examined whether the lysosomal inhibitor, ammonium chloride (NH(4)Cl) could prevent the autophagy flux by inhibiting the fusion of autophagosomes with lysosomes and enhance apoptosis induced by menadione via mitochondrial pathway. The results demonstrated generation and accumulation of reactive oxygen species and increased levels of ubiquitinated proteins and GRP78 in cells treated with both menadione and NH(4)Cl. Our data indicates that lysosomal system through autophagy plays an important role in preventing menadione-induced apoptosis in Hela cells by clearing misfolded proteins, which alleviates endoplasmic reticulum stress.

  12. Haemodynamics during maximal exercise after coronary bypass surgery

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); M.F. Rousseau (Francois); J. Cosyns; R. Ponlot; L.A. Brasseur; J-M.R. Detry (Jean-Marie)

    1978-01-01

    textabstractFifty patients underwent an objective measurement of physical working capacity by means of a multistage test of maximally tolerated exertion before and after coronary bypass surgery; 29 patients also had haemodynamic measurements during maximal exercise before and after coronary bypass s

  13. Renal tubular acidosis secondary to jejunoileal bypass for morbid obesity

    DEFF Research Database (Denmark)

    Schaffalitzky de Muckadell, O B; Ladefoged, Jens; Thorup, Jørgen Mogens

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...

  14. 20 CFR 631.38 - State by-pass authority.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false State by-pass authority. 631.38 Section 631.38 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE III OF THE JOB TRAINING PARTNERSHIP ACT State Administration § 631.38 State by-pass authority....

  15. Computed tomography perfusion evaluation after extracranial-intracranial bypass surgery

    NARCIS (Netherlands)

    Vos, P.C.; Riordan, A.J.; Smit, E.J.; Jong, H.W. de; Zwan, A. van der; Velthuis, B.K.; Viergever, M.A.; Dankbaar, J.W.

    2015-01-01

    OBJECTIVE: Perfusion imaging is increasingly used for postoperative evaluation of extracranial to intracranial (EC-IC) bypass surgery. Altered hemodynamics and delayed arrival of the contrast agent in the area fed by the bypass can influence perfusion measurement. We compared perfusion asymmetry obt

  16. Computed tomography perfusion evaluation after extracranial-intracranial bypass surgery

    NARCIS (Netherlands)

    Vos, Pieter C.; Riordan, Alan J.; Smit, Ewoud J.; de Jong, Hugo W. A. M.; van der Zwan, Albert; Velthuis, BK; Viergever, Max A.; Dankbaar, Jan Willem

    2015-01-01

    Objective: Perfusion imaging is increasingly used for postoperative evaluation of extracranial to intracranial (EC-IC) bypass surgery. Altered hemodynamics and delayed arrival of the contrast agent in the area fed by the bypass can influence perfusion measurement. We compared perfusion asymmetry obt

  17. Lower leg electrical impedance after distal bypass surgery

    DEFF Research Database (Denmark)

    Belanger, G K; Bolbjerg, M L; Heegaard, N H;

    1998-01-01

    Electrical impedance was determined in 13 patients following distal bypass surgery to evaluate lower leg oedema as reflected by its circumference. Tissue injury was assessed by the plasma concentration of muscle enzymes. After surgery, the volume of the control lower leg increased from 1250 (816...... to be a useful method for the evaluation of lower leg oedema after distal bypass surgery....

  18. Diagnostic tools for post-gastric bypass hypoglycaemia

    NARCIS (Netherlands)

    Emous, M.; Ubels, F. L.; van Beek, A. P.

    2015-01-01

    In spite of its evident success, several late complications can occur after gastric bypass surgery. One of these is post-gastric bypass hypoglycaemia. No evidence-based guidelines exist in the literature on how to confirm the presence of this syndrome. This study aims to describe and compare the tes

  19. Sen perforation af tyndtarm efter laparoskopisk gastrisk bypass

    DEFF Research Database (Denmark)

    Spanager, Lene; Sigild, Ulf Henrik; Neuenschwander, Anders Ulrich

    2010-01-01

    We present two cases in which the patients were admitted to a local hospital with acute abdominal pain four or five months after having undergone laparoscopic gastric bypass. In both cases, operation revealed a perforation of the small bowel close to the distal anastomosis. In the first case...... bypass but as our two cases illustrate they are important to keep in mind....

  20. The in situ saphenous vein bypass graft: radiologic aspects.

    Science.gov (United States)

    Schwarz, W; Nozick, J; Richmand, D; Rodgers, B; Simpson, A; Argila, C; Honickman, S

    1986-03-01

    The use of the in situ saphenous vein for bypassing arterial occlusions in the lower extremities appears to have a higher patency rate than other bypass procedures but presents unique technical problems, such as lysing valves and occluding venous tributaries. Forty-four patients undergoing in situ bypasses had preoperative arteriograms. Special attention was paid to the small runoff vessels around the ankle, which are not suitable for reversed bypass procedures but may be adequate for in situ bypasses. Eight patients also had preoperative saphenous venograms, which revealed surgically important abnormalities in six cases. Postoperative arteriograms obtained within 2 weeks in 10 patients and within 2-12 months in 15 patients revealed persistent arteriovenous fistulas in four patients, stenoses in nine, occlusions in five, and progressive disease in the nonbypassed arteries in five patients. Early recognition of these problems led to 11 surgical repairs; nine repairs used the interventional radiologic procedures of balloon angioplasty, transcatheter embolization, and catheter thrombolysis. In this group of 44 patients, five patients died with patent bypasses and three patients required amputation despite functioning bypasses. Only four amputations were attributed to bypass failure. This low figure may be due to the close cooperation of the vascular surgeons and the vascular radiologists in dealing with these complicated cases.

  1. Magnesium Modulates Doxorubicin Activity through Drug Lysosomal Sequestration and Trafficking.

    Science.gov (United States)

    Trapani, Valentina; Luongo, Francesca; Arduini, Daniela; Wolf, Federica I

    2016-03-21

    Magnesium is directly involved in the control of cell growth and survival, but its role in cancer biology and therapy is multifaceted; in particular, it is highly controversial whether magnesium levels can affect therapy outcomes. Here we investigated whether magnesium availability can modulate cellular responses to the widely used chemotherapeutic doxorubicin. We used an in vitro model consisting of mammary epithelial HC11 cells and found that high magnesium availability was correlated with diminished sensitivity both in cells chronically adapted to high magnesium concentrations and in acutely magnesium-supplemented cells. This decrease in sensitivity resulted from reduced intracellular doxorubicin accumulation in the face of a similar drug uptake rate. We observed that high-magnesium conditions caused a decrease in intracellular drug retention by altering drug lysosomal sequestration and trafficking. In our model, magnesium supplementation correspondingly modulated expression of the TRPM7 channel, which is known to control cytoskeletal organization and dynamics and may be involved in the proposed mechanism. Our findings suggest that magnesium supplementation in hypomagnesemic cancer patients may hinder response to therapy.

  2. Less Is More: Substrate Reduction Therapy for Lysosomal Storage Disorders

    Directory of Open Access Journals (Sweden)

    Maria Francisca Coutinho

    2016-07-01

    Full Text Available Lysosomal storage diseases (LSDs are a group of rare, life-threatening genetic disorders, usually caused by a dysfunction in one of the many enzymes responsible for intralysosomal digestion. Even though no cure is available for any LSD, a few treatment strategies do exist. Traditionally, efforts have been mainly targeting the functional loss of the enzyme, by injection of a recombinant formulation, in a process called enzyme replacement therapy (ERT, with no impact on neuropathology. This ineffectiveness, together with its high cost and lifelong dependence is amongst the main reasons why additional therapeutic approaches are being (and have to be investigated: chaperone therapy; gene enhancement; gene therapy; and, alternatively, substrate reduction therapy (SRT, whose aim is to prevent storage not by correcting the original enzymatic defect but, instead, by decreasing the levels of biosynthesis of the accumulating substrate(s. Here we review the concept of substrate reduction, highlighting the major breakthroughs in the field and discussing the future of SRT, not only as a monotherapy but also, especially, as complementary approach for LSDs.

  3. Dacron or PTFE for above-knee femoropopliteal bypass. a multicenter randomised study

    DEFF Research Database (Denmark)

    Jensen, L P; Lepäntalo, M; Fossdal, J E

    2007-01-01

    To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass.......To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass....

  4. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

    OpenAIRE

    Ouyang Xiaosen; Liang Qiuli; Schneider Lonnie; Zhang Jianhua

    2011-01-01

    Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt) protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease a...

  5. Action of polystyrene nanoparticles of different sizes on lysosomal function and integrity

    OpenAIRE

    Fröhlich Eleonore; Meindl Claudia; Roblegg Eva; Ebner Birgit; Absenger Markus; Pieber Thomas R

    2012-01-01

    Abstract Background Data from environmental exposure to nanoparticles (NPs) suggest that chronic exposure may increase the incidence of lung, cardiovascular and neurodegenerative diseases. Impairment of cell function by intracellular accumulation of NPs is also suspected. Many types of NPs have been detected in the endosomal-lysosomal system and, upon repeated exposure, alterations of the endosomal-lysosomal system may occur. To identify such effects we compared the effect of carboxyl polysty...

  6. Lysosomal responses to heat-shock of seasonal temperature extremes in Cd-exposed mussels.

    Science.gov (United States)

    Múgica, M; Izagirre, U; Marigómez, I

    2015-07-01

    The present study was aimed at determining the effect of temperature extremes on lysosomal biomarkers in mussels exposed to a model toxic pollutant (Cd) at different seasons. For this purpose, temperature was elevated 10°C (from 12°C to 22°C in winter and from 18°C to 28°C in summer) for a period of 6h (heat-shock) in control and Cd-exposed mussels, and then returned back to initial one. Lysosomal membrane stability and lysosomal structural changes in digestive gland were investigated. In winter, heat-shock reduced the labilisation period (LP) of the lysosomal membrane, especially in Cd-exposed mussels, and provoked transient lysosomal enlargement. LP values recovered after the heat-shock cessation but lysosomal enlargement prevailed in both experimental groups. In summer, heat-shock induced remarkable reduction in LP and lysosomal enlargement (more markedly in Cd-exposed mussels), which recovered within 3 days. Besides, whilst heat-shock effects on LP were practically identical for Cd-exposed mussels in winter and summer, the effects were longer-lasting in summer than in winter for control mussels. Thus, lysosomal responsiveness after heat-shock was higher in summer than in winter but recovery was faster as well, and therefore the consequences of the heat shock seem to be more decisive in winter. In contrast, inter-season differences were attenuated in the presence of Cd. Consequently, mussels seem to be better prepared in summer than in winter to stand short periods of abrupt temperature change; this is, however, compromised when mussels are exposed to pollutants such as Cd.

  7. The BH3 Mimetic Obatoclax Accumulates in Lysosomes and Causes Their Alkalinization.

    Directory of Open Access Journals (Sweden)

    Vasileios A Stamelos

    Full Text Available Obatoclax belongs to a class of compounds known as BH3 mimetics which function as antagonists of Bcl-2 family apoptosis regulators. It has undergone extensive preclinical and clinical evaluation as a cancer therapeutic. Despite this, it is clear that obatoclax has additional pharmacological effects that contribute to its cytotoxic activity. It has been claimed that obatoclax, either alone or in combination with other molecularly targeted therapeutics, induces an autophagic form of cell death. In addition, obatoclax has been shown to inhibit lysosomal function, but the mechanism of this has not been elucidated. We have evaluated the mechanism of action of obatoclax in eight ovarian cancer cell lines. Consistent with its function as a BH3 mimetic, obatoclax induced apoptosis in three cell lines. However, in the remaining cell lines another form of cell death was evident because caspase activation and PARP cleavage were not observed. Obatoclax also failed to show synergy with carboplatin and paclitaxel, chemotherapeutic agents which we have previously shown to be synergistic with authentic Bcl-2 family antagonists. Obatoclax induced a profound accumulation of LC-3 but knockdown of Atg-5 or beclin had only minor effects on the activity of obatoclax in cell growth assays suggesting that the inhibition of lysosomal function rather than stimulation of autophagy may play a more prominent role in these cells. To evaluate how obatoclax inhibits lysosomal function, confocal microscopy studies were conducted which demonstrated that obatoclax, which contains two basic pyrrole groups, accumulates in lysosomes. Studies using pH sensitive dyes demonstrated that obatoclax induced lysosomal alkalinization. Furthermore, obatoclax was synergistic in cell growth/survival assays with bafilomycin and chloroquine, two other drugs which cause lysosomal alkalinization. These studies explain, for the first time, how obatoclax inhibits lysosomal function and suggest that

  8. Observation of intracellular interactions between DNA origami and lysosomes by the fluorescence localization method.

    Science.gov (United States)

    Fu, Meifang; Dai, Luru; Jiang, Qiao; Tang, Yunqing; Zhang, Xiaoming; Ding, Baoquan; Li, Junbai

    2016-07-28

    We obtained the fluorescence localization images of tube DNA origami nanostructures in NIH 3T3 cells for the first time. The fluorescence localization images of tube DNA origami nanostructures and TIRF images of lysosomes were combined and they revealed the detailed interactions between the two structures. Quantitative analysis illustrated that the tube origami can be captured as well as degraded by lysosomes with time.

  9. Streptococcus oralis Induces Lysosomal Impairment of Macrophages via Bacterial Hydrogen Peroxide.

    Science.gov (United States)

    Okahashi, Nobuo; Nakata, Masanobu; Kuwata, Hirotaka; Kawabata, Shigetada

    2016-07-01

    Streptococcus oralis, an oral commensal, belongs to the mitis group of streptococci and occasionally causes opportunistic infections, such as bacterial endocarditis and bacteremia. Recently, we found that the hydrogen peroxide (H2O2) produced by S. oralis is sufficient to kill human monocytes and epithelial cells, implying that streptococcal H2O2 is a cytotoxin. In the present study, we investigated whether streptococcal H2O2 impacts lysosomes, organelles of the intracellular digestive system, in relation to cell death. S. oralis infection induced the death of RAW 264 macrophages in an H2O2-dependent manner, which was exemplified by the fact that exogenous H2O2 also induced cell death. Infection with either a mutant lacking spxB, which encodes pyruvate oxidase responsible for H2O2 production, or Streptococcus mutans, which does not produce H2O2, showed less cytotoxicity. Visualization of lysosomes with LysoTracker revealed lysosome deacidification after infection with S. oralis or exposure to H2O2, which was corroborated by acridine orange staining. Similarly, fluorescent labeling of lysosome-associated membrane protein-1 gradually disappeared during infection with S. oralis or exposure to H2O2 The deacidification and the following induction of cell death were inhibited by chelating iron in lysosomes. Moreover, fluorescent staining of cathepsin B indicated lysosomal destruction. However, treatment of infected cells with a specific inhibitor of cathepsin B had negligible effects on cell death; instead, it suppressed the detachment of dead cells from the culture plates. These results suggest that streptococcal H2O2 induces cell death with lysosomal destruction and then the released lysosomal cathepsins contribute to the detachment of the dead cells.

  10. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

    Directory of Open Access Journals (Sweden)

    Ouyang Xiaosen

    2011-06-01

    Full Text Available Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease activities may contribute to toxicity whereas others are consistent with protection. These discrepancies may be due to a number of mechanisms including distinct effects of the specific intermediate digestion products of mutant huntingtin generated by different proteases. These observations suggested a critical need to investigate the consequence of upregulation of individual lysosomal enzyme in mutant huntingtin accumulation and toxicity. Results In this study, we used molecular approaches to enhance lysosomal protease activities and examined their effects on mutant huntingtin level and toxicity. We found that enhanced expression of lysosomal cathepsins D and B resulted in their increased enzymatic activities and reduced both full-length and fragmented huntingtin in transfected HEK cells. Furthermore, enhanced expression of cathepsin D or B protected against mutant huntingtin toxicity in primary neurons, and their neuroprotection is dependent on macroautophagy. Conclusions These observations demonstrate a neuroprotective effect of enhancing lysosomal cathepsins in reducing mutant huntingtin level and toxicity in transfected cells. They highlight the potential importance of neuroprotection mediated by cathepsin D or B through macroautophagy.

  11. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability.

    Science.gov (United States)

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan; Li, Longjiang

    2015-11-01

    Para-toluenesulfonamide (PTS) has been implicated with anticancer effects against a variety of tumors. In the present study, we investigated the inhibitory effects of PTS on tongue squamous cell carcinoma (Tca-8113) and explored the lysosomal and mitochondrial changes after PTS treatment in vitro. High-performance liquid chromatography showed that PTS selectively accumulated in Tca-8113 cells with a relatively low concentration in normal fibroblasts. Next, the effects of PTS on cell viability, invasion, and cell death were determined. PTS significantly inhibited Tca-8113 cells' viability and invasive ability with increased cancer cell death. Flow cytometric analysis and the lactate dehydrogenase release assay showed that PTS induced cancer cell death by activating apoptosis and necrosis simultaneously. Morphological changes, such as cellular shrinkage, nuclear condensation as well as formation of apoptotic body and secondary lysosomes, were observed, indicating that PTS might induce cell death through disturbing lysosomal stability. Lysosomal integrity assay and western blot showed that PTS increased lysosomal membrane permeabilization associated with activation of lysosomal cathepsin B. Finally, PTS was shown to inhibit ATP biosynthesis and induce the release of mitochondrial cytochrome c. Therefore, our findings provide a novel insight into the use of PTS in cancer therapy.

  12. TMEM175 deficiency impairs lysosomal and mitochondrial function and increases α-synuclein aggregation

    Science.gov (United States)

    Jinn, Sarah; Drolet, Robert E.; Cramer, Paige E.; Wong, Andus Hon-Kit; Toolan, Dawn M.; Gretzula, Cheryl A.; Voleti, Bhavya; Vassileva, Galya; Disa, Jyoti; Tadin-Strapps, Marija; Stone, David J.

    2017-01-01

    Parkinson disease (PD) is a neurodegenerative disorder pathologically characterized by nigrostriatal dopamine neuron loss and the postmortem presence of Lewy bodies, depositions of insoluble α-synuclein, and other proteins that likely contribute to cellular toxicity and death during the disease. Genetic and biochemical studies have implicated impaired lysosomal and mitochondrial function in the pathogenesis of PD. Transmembrane protein 175 (TMEM175), the lysosomal K+ channel, is centered under a major genome-wide association studies peak for PD, making it a potential candidate risk factor for the disease. To address the possibility that variation in TMEM175 could play a role in PD pathogenesis, TMEM175 function was investigated in a neuronal model system. Studies confirmed that TMEM175 deficiency results in unstable lysosomal pH, which led to decreased lysosomal catalytic activity, decreased glucocerebrosidase activity, impaired autophagosome clearance by the lysosome, and decreased mitochondrial respiration. Moreover, TMEM175 deficiency in rat primary neurons resulted in increased susceptibility to exogenous α-synuclein fibrils. Following α-synuclein fibril treatment, neurons deficient in TMEM175 were found to have increased phosphorylated and detergent-insoluble α-synuclein deposits. Taken together, data from these studies suggest that TMEM175 plays a direct and critical role in lysosomal and mitochondrial function and PD pathogenesis and highlight this ion channel as a potential therapeutic target for treating PD. PMID:28193887

  13. Cross-talk between TRPML1 channel, lipids and lysosomal storage diseases.

    Science.gov (United States)

    Weiss, Norbert

    2012-03-01

    Described by the Belgian cytologist Christian De Duve in 1949,(1) lysosomes (from the Greek "digestive bodies") are ubiquitous specialized intracellular organelles that ensure the degradation/recycling of macromolecules (proteins, lipids, membranes) through the activity of specific enzymes (i.e., acid hydrolases). They receive their substrates through different internalization pathways (i.e., endocytosis, phagocytosis and autophagy) and are involved in a wide range of physiological functions from cell death and signaling to cholesterol homeostasis and plasma membrane repair.(2) In Mammals, 50 soluble lysosomal hydrolases have been described, each targeting specific substrates. They are confined in the lumen of the lysosome and require an optimum pH (i.e., pH 4.5) to work. This acidic pH compared with the slightly alkaline pH of the cytosol (i.e., ~pH 7.2) is maintained by the activity of integral lysosomal membrane proteins (LMPs, that represent the second class of lysosomal proteins), including the V-type proton (H(+))-ATPase(3) and the chloride ion channel CLC7(4) that pumps protons from the cytosol across the lysosomal membrane.

  14. Complement activation in coronary artery bypass grafting patients without cardiopulmonary bypass - The role of tissue injury by surgical incision

    NARCIS (Netherlands)

    Gu, YJ; Mariani, MA; Boonstra, PW; Grandjean, JG; van Oeveren, W

    1999-01-01

    Study objectives: Complement activation is a trigger in inducing inflammation in patients who undergo coronary artery bypass grafting (CABG) and is usually thought to be induced by the use of cardiopulmonary bypass (CPB), In this study, we examined whether tissue injury caused by chest surgical inci

  15. Enhancing lysosomal biogenesis and autophagic flux by activating the transcription factor EB protects against cadmium-induced neurotoxicity

    Science.gov (United States)

    Pi, Huifeng; Li, Min; Tian, Li; Yang, Zhiqi; Yu, Zhengping; Zhou, Zhou

    2017-01-01

    Cadmium (Cd), a highly ubiquitous heavy metal, is a well-known inducer of neurotoxicity. However, the mechanism underlying cadmium-induced neurotoxicity remains unclear. In this study, we found that Cd inhibits autophagosome-lysosome fusion and impairs lysosomal function by reducing the levels of lysosomal-associated membrane proteins, inhibiting lysosomal proteolysis and altering lysosomal pH, contributing to defects in autophagic clearance and subsequently leading to nerve cell death. In addition, Cd decreases transcription factor EB (TFEB) expression at both the mRNA and protein levels. Furthermore, Cd induces the nuclear translocation of TFEB and TFEB target-gene expression, associated with compromised lysosomal function or a compensatory effect after the impairment of the autophagic flux. Notably, restoration of the levels of lysosomal-associated membrane protein, lysosomal proteolysis, lysosomal pH and autophagic flux through Tfeb overexpression protects against Cd-induced neurotoxicity, and this protective effect is incompletely dependent on TFEB nuclear translocation. Moreover, gene transfer of the master autophagy regulator TFEB results in the clearance of toxic proteins and the correction of Cd-induced neurotoxicity in vivo. Our study is the first to demonstrate that Cd disrupts lysosomal function and autophagic flux and manipulation of TFEB signalling may be a therapeutic approach for antagonizing Cd-induced neurotoxicity. PMID:28240313

  16. Membrane cholesterol regulates lysosome-plasma membrane fusion events and modulates Trypanosoma cruzi invasion of host cells.

    Directory of Open Access Journals (Sweden)

    Bárbara Hissa

    Full Text Available BACKGROUND: Trypomastigotes of Trypanosoma cruzi are able to invade several types of non-phagocytic cells through a lysosomal dependent mechanism. It has been shown that, during invasion, parasites trigger host cell lysosome exocytosis, which initially occurs at the parasite-host contact site. Acid sphingomyelinase released from lysosomes then induces endocytosis and parasite internalization. Lysosomes continue to fuse with the newly formed parasitophorous vacuole until the parasite is completely enclosed by lysosomal membrane, a process indispensable for a stable infection. Previous work has shown that host membrane cholesterol is also important for the T. cruzi invasion process in both professional (macrophages and non-professional (epithelial phagocytic cells. However, the mechanism by which cholesterol-enriched microdomains participate in this process has remained unclear. METHODOLOGY/PRINCIPAL FINDING: In the present work we show that cardiomyocytes treated with MβCD, a drug able to sequester cholesterol from cell membranes, leads to a 50% reduction in invasion by T. cruzi trypomastigotes, as well as a decrease in the number of recently internalized parasites co-localizing with lysosomal markers. Cholesterol depletion from host membranes was accompanied by a decrease in the labeling of host membrane lipid rafts, as well as excessive lysosome exocytic events during the earlier stages of treatment. Precocious lysosomal exocytosis in MβCD treated cells led to a change in lysosomal distribution, with a reduction in the number of these organelles at the cell periphery, and probably compromises the intracellular pool of lysosomes necessary for T. cruzi invasion. CONCLUSION/SIGNIFICANCE: Based on these results, we propose that cholesterol depletion leads to unregulated exocytic events, reducing lysosome availability at the cell cortex and consequently compromise T. cruzi entry into host cells. The results also suggest that two different pools of

  17. A marked increase in gastric fluid volume during cardiopulmonary bypass

    Science.gov (United States)

    Hirota, Kazuyoshi; Kudo, Mihoko; Hashimoto, Hiroshi; Kushikata, Tetsuya

    2011-01-01

    Major physiological stress occurs during cardiac surgery with cardiopulmonary bypass. This is related to hypothermia and artificial organ perfusion. Thus, serious gastrointestinal complications, particularly upper gastrointestinal bleeding, sometimes follow cardiac surgery. We have compared the antisecretory effects of a preanesthetic H2 antagonist (roxatidine, cardiopulmonary bypass-H2 group, n = 15) and a proton pump inhibitor (rabeprazole, cardiopulmonary bypass-PPI group, n = 15) in patients undergoing cardiac surgery with cardiopulmonary bypass, and also compared in patients undergoing a off-pump coronary artery bypass graft surgery (off-pump cardiopulmonary bypass-H2 group, n = 15). Gastric pH (5.14 ± 0.61) and gastric fluid volume (13.2 ± 2.4 mL) at the end of surgery in off-pump cardiopulmonary bypass-H2 groups was significantly lower and higher than those in both cardiopulmonary bypass-H2 (6.25 ± 0.54, 51.3 ± 8.0 mL) and cardiopulmonary bypass-PPI (7.29 ± 0.13, 63.5 ± 14.8 mL) groups, respectively although those variables did not differ between groups after the induction of anesthesia. Plasma gastrin (142 ± 7 pg/mL) at the end of surgery and maximal blood lactate levels (1.50 ± 0.61 mM) in off-pump cardiopulmonary bypass-H2 group were also significantly lower than those in both cardiopulmonary bypass-H2 (455 ± 96 pg/mL, 3.97 ± 0.80 mM) and cardiopulmonary bypass-PPI (525 ± 27 pg/mL, 3.15 ± 0.44 mM) groups, respectively. In addition, there was a significant correlation between gastric fluid volume and maximal blood lactate (r = 0.596). In conclusion, cardiopulmonary bypass may cause an increase in gastric fluid volume which neither H2 antagonist nor PPI suppresses. A significant correlation between gastric fluid volume and maximal blood lactate suggests that gastric fluid volume may predict degree of gastrointestinal tract hypoperfusion. PMID:21765601

  18. Bypass technology enhances the efficiency of wind power plants; Bypass-Technologie erhoeht WEA-Effizienz

    Energy Technology Data Exchange (ETDEWEB)

    Ebach, Thorsten [EKS Engel GmbH und Co. KG, Wenden (Germany)

    2013-04-01

    A reliable operation of wind power parks significantly depends on a trouble-free data communication. If one or more network participants break down, then it depends on the topology whether the complete power distribution system is available or not. An optical bypass such as it is supplied by EKS Engel GmbH and Co. KG (Wenden, Federal Republic of Germany) offers a remedial action.

  19. Lysosomal {beta}-mannosidase: cDNA cloning and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Leipprandt, J.R.; Traviss, C.E. [Michigan State Univ., East Lansing, MI (United States)] [and others

    1994-09-01

    Lysosomal {beta}-mannosidase is an exoglycosidase that cleaves the single {beta}-linked mannose residue from the non-reducing end of all N-linked glycoprotein oligosaccharides. Deficiency of this enzyme results in {beta}-mannosidosis, a severe neurodegenerative disease in goats and cattle. The human cases described have a milder, highly variable presentation. Study of the molecular pathology of this disease in ruminants and humans and development of the animal model for gene therapy studies required cloning of the gene for {beta}-mannosidase has been cloned. {beta}-Mannosidase cDNA were obtained from a bovine thyroid cDNA library by screening with mixed oligonucleotides derived from peptide sequences resulting from microsequencing of bovine {beta}-mannosidase peptides. A total of six independent positive clones were identified from 5 x 10{sup 5} plaques, covering about 80% of the C-terminal region. The missing 5{prime} region was obtained using 5{prime} RACE. The full-length construct contains 3852-bp nucleotides, encoding 879 amino acids. The initiation codon is followed by 17 amino acids containing the characteristics of a typical signal peptide sequence. The deduced amino acid sequence is colinear with all peptide sequences determined by protein microsequencing. Northern blot analysis demonstrated a 4.2 kb single transcript in various tissues from both normal and affected goats and calves. The mRNA level was decreased in affected {beta}-mannosidosis animals. The gene encoding {beta}-mannosidase was localized on human chromosome 4 by Southern analysis of rodent/human somatic cell hybrids. The mutation in bovine {beta}-mannosidosis has been identified. This is the first report of cloning of the {beta}-mannosidase gene.

  20. Emergent cardiopulmonary bypass during pectus excavatum repair

    Directory of Open Access Journals (Sweden)

    Ryan Craner

    2013-01-01

    Full Text Available Pectus excavatum is a chest wall deformity that produces significant cardiopulmonary disability and is typically seen in younger patients. Minimally invasive repair of pectus excavatum or Nuss procedure has become a widely accepted technique for adult and pediatric patients. Although it is carried out through a thoracoscopic approach, the procedure is associated with a number of potential intraoperative and post-operative complications. We present a case of cardiac perforation requiring emergent cardiopulmonary bypass in a 29-year-old male with Marfan syndrome and previous mitral valve repair undergoing a Nuss procedure for pectus excavatum. This case illustrates the importance of vigilance and preparation by the surgeons, anesthesia providers as well as the institution to be prepared with resources to handle the possible complications. This includes available cardiac surgical backup, perfusionist support and adequate blood product availability.

  1. Transient Diabetes Insipidus Following Cardiopulmonary Bypass.

    Science.gov (United States)

    Ekim, Meral; Ekim, Hasan; Yilmaz, Yunus Keser; Bolat, Ali

    2015-04-01

    Diabetes insipidus (DI) results from inadequate output of Antidiuretic Hormone (ADH) from the pituitary gland (central DI) or the inability of the kidney tubules to respond to ADH (nephrogenic DI). ADH is an octapeptide produced in the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior lobe of the pituitary gland. Cardiopulmonary Bypass (CPB) has been shown to cause a six-fold increased circulating ADH levels 12 hours after surgery. However, in some cases, ADH release may be transiently suppressed due to cardioplegia (cardiac standstill) or CPB leading to DI. We present the postoperative course of a 60-year-old man who developed transient DI after CPB. He was successfully treated by applying nasal desmopressin therapy. Relevant biochemical parameters should be monitored closely in patients who produce excessive urine after open heart surgery.

  2. Current status of coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin

    2009-01-01

    @@ Surgical revascularization for atherosclerotic heart disease, also called coronary artery bypass grafting (CABG), was first performed in 1962, and is one of the great achievements in medicine. Relief of angina, improvement of exercise tolerance, and the realization of survival benefit have been documented.1 CABG has been used in multi-vessel disease and left main stenosis for over 40 years.2 In the last two decades the mortality of CABG has decreased to less than 2% despite an aging population with increased risk factors. However, percutaneous coronary intervention (PCI), especially with drug-eluting stents, has been challenging CABG, While PCI has improved, CABG has also progressed with better peri-operative management, a higher use of arterial grafting, off-pump surgery, and improved techniques with minimally invasive surgical options.3,4

  3. CFD Analysis of Core Bypass Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2009-11-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

  4. CFD Analysis of Core Bypass Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2010-03-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

  5. Alongshore sediment bypassing as a control on river mouth morphodynamics

    Science.gov (United States)

    Nienhuis, Jaap H.; Ashton, Andrew D.; Nardin, William; Fagherazzi, Sergio; Giosan, Liviu

    2016-04-01

    River mouths, shoreline locations where fluvial and coastal sediments are partitioned via erosion, trapping, and redistribution, are responsible for the ultimate sedimentary architecture of deltas and, because of their dynamic nature, also pose great management and engineering challenges. To investigate the interaction between fluvial and littoral processes at wave-dominated river mouths, we modeled their morphologic evolution using the coupled hydrodynamic and morphodynamic model Delft3D-SWAN. Model experiments replicate alongshore migration of river mouths, river mouth spit development, and eventual spit breaching, suggesting that these are emergent phenomena that can develop even under constant fluvial and wave conditions. Furthermore, we find that sediment bypassing of a river mouth develops though feedbacks between waves and river mouth morphology, resulting in either continuous bypassing pathways or episodic bar bypassing pathways. Model results demonstrate that waves refracting into the river mouth bar create a zone of low alongshore sediment transport updrift of the river mouth, which reduces sediment bypassing. Sediment bypassing, in turn, controls the river mouth migration rate and the size of the river mouth spit. As a result, an intermediate amount of river discharge maximizes river mouth migration. The fraction of alongshore sediment bypassing can be predicted from the balance between the jet and the wave momentum flux. Quantitative comparisons show a match between our modeled predictions of river mouth bypassing and migration rates observed in natural settings.

  6. Seasonal Variation of Climatological Bypassing Flows around the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; ZHANG Renhe

    2012-01-01

    The present study investigated diagnostically the seasonal variation of the bypassing flows caused by the splitting effect of the Tibetan Plateau (TP).The relationships among the splitting bypassing flows around the TP to precipitation in China,the westerly jet stream,and the thermal status over the TP are revealed.The bypassing flows occur from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively,and they disappear from the 29th to the 58th pentad.They are strongest in winter from the 1st to the 22nd pentad and from the 59th to the 73rd pentad,respectively.During the rebuilding of the bypassing flows from mid-October to mid-February,they are the main cause of precipitation over southeastern China.The enhancement of the bypassing flow intensity in March cau cause the precipitation to increase in the early stage of the persistent spring rain over southeastern China.From winter to summer,the seasonal transition of the bypassing flows in the lower troposphere precedes that of the westerly jet stream axis in the upper troposphere to the west of the TP by ~4 pentads,while from summer to winter lags by ~4 pentads.The seasonal variation of the thermal status over the TP plays an important role in the bypassing flows around the TP.The strengthening of the heating over the TP weakens the bypassing flows,and the increase in cooling over the TP is related to the rebuilding and strengthening of the bypassing flows.

  7. Interactions between autophagic and endo-lysosomal markers in endothelial cells.

    Science.gov (United States)

    Oeste, Clara L; Seco, Esther; Patton, Wayne F; Boya, Patricia; Pérez-Sala, Dolores

    2013-05-01

    Autophagic and endo-lysosomal degradative pathways are essential for cell homeostasis. Availability of reliable tools to interrogate these pathways is critical to unveil their involvement in physiology and pathophysiology. Although several probes have been recently developed to monitor autophagic or lysosomal compartments, their specificity has not been validated through co-localization studies with well-known markers. Here, we evaluate the selectivity and interactions between one lysosomal (Lyso-ID) and one autophagosomal (Cyto-ID) probe under conditions modulating autophagy and/or endo-lysosomal function in live cells. The probe for acidic compartments Lyso-ID was fully localized inside vesicles positive for markers of late endosome-lysosomes, including Lamp1-GFP and GFP-CINCCKVL. Induction of autophagy by amino acid deprivation in bovine aortic endothelial cells caused an early and potent increase in the fluorescence of the proposed autophagy dye Cyto-ID. Cyto-ID-positive compartments extensively co-localized with the autophagosomal fluorescent reporter RFP-LC3, although the time and/or threshold for organelle detection was different for each probe. Interestingly, use of Cyto-ID in combination with Lysotracker Red or Lyso-ID allowed the observation of structures labeled with either one or both probes, the extent of co-localization increasing upon treatment with protease inhibitors. Inhibition of the endo-lysosomal pathway with chloroquine or U18666A resulted in the formation of large Cyto-ID and Lyso-ID-positive compartments. These results constitute the first assessment of the selectivity of Cyto-ID and Lyso-ID as probes for the autophagic and lysosomal pathways, respectively. Our observations show that these probes can be used in combination with protein-based markers for monitoring the interactions of both pathways in live cells.

  8. The Phosphoinositide-Gated Lysosomal Ca(2+) Channel, TRPML1, Is Required for Phagosome Maturation.

    Science.gov (United States)

    Dayam, Roya M; Saric, Amra; Shilliday, Ryan E; Botelho, Roberto J

    2015-09-01

    Macrophages internalize and sequester pathogens into a phagosome. Phagosomes then sequentially fuse with endosomes and lysosomes, converting into degradative phagolysosomes. Phagosome maturation is a complex process that requires regulators of the endosomal pathway including the phosphoinositide lipids. Phosphatidylinositol-3-phosphate and phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P2 ), which respectively control early endosomes and late endolysosomes, are both required for phagosome maturation. Inhibition of PIKfyve, which synthesizes PtdIns(3,5)P2 , blocked phagosome-lysosome fusion and abated the degradative capacity of phagosomes. However, it is not known how PIKfyve and PtdIns(3,5)P2 participate in phagosome maturation. TRPML1 is a PtdIns(3,5)P2 -gated lysosomal Ca(2+) channel. Because Ca(2+) triggers membrane fusion, we postulated that TRPML1 helps mediate phagosome-lysosome fusion. Using Fcγ receptor-mediated phagocytosis as a model, we describe our research showing that silencing of TRPML1 hindered phagosome acquisition of lysosomal markers and reduced the bactericidal properties of phagosomes. Specifically, phagosomes isolated from TRPML1-silenced cells were decorated with lysosomes that docked but did not fuse. We could rescue phagosome maturation in TRPML1-silenced and PIKfyve-inhibited cells by forcible Ca(2+) release with ionomycin. We also provide evidence that cytosolic Ca(2+) concentration increases upon phagocytosis in a manner dependent on TRPML1 and PIKfyve. Overall, we propose a model where PIKfyve and PtdIns(3,5)P2 activate TRPML1 to induce phagosome-lysosome fusion.

  9. Expression of the lysosomal-associated membrane protein-1 (LAMP-1) in astrocytomas.

    Science.gov (United States)

    Jensen, Stine S; Aaberg-Jessen, Charlotte; Christensen, Karina G; Kristensen, Bjarne

    2013-01-01

    Targeting of lysosomes is a novel therapeutic anti-cancer strategy for killing the otherwise apoptosis-resistant cancer cells. Such strategies are urgently needed for treatment of brain tumors, especially the glioblastoma, which is the most frequent and most malignant type. The aim of the present study was to investigate the presence of lysosomes in astrocytic brain tumors focussing also on the therapy resistant tumor stem cells. Expression of the lysosomal marker LAMP-1 (lysosomal-associated membrane protein-1) was investigated by immunohistochemistry in 112 formalin fixed paraffin embedded astrocytomas and compared with tumor grade and overall patient survival. Moreover, double immunofluorescence stainings were performed with LAMP-1 and the astrocytic marker GFAP and the putative stem cell marker CD133 on ten glioblastomas. Most tumors expressed the LAMP-1 protein in the cytoplasm of the tumor cells, while the blood vessels were positive in all tumors. The percentage of LAMP-1 positive tumor cells and staining intensities increased with tumor grade but variations in tumors of the same grade were also found. No association was found between LAMP-1 expression and patient overall survival in the individual tumor grades. LAMP-1/GFAP showed pronounced co-expression and LAMP-1/CD133 was co-expressed as well suggesting that tumor cells including the proposed tumor stem cells contain lysosomes. The results suggest that high amounts of lysosomes are present in glioblastomas and in the proposed tumor stem cells. Targeting of lysosomes may be a promising novel therapeutic strategy against this highly malignant neoplasm.

  10. Asendan Desendan Aortic Bypass: Atan Kalpte Mediyan Sternotomi Yoluyla Onarim

    Directory of Open Access Journals (Sweden)

    Muhammet Akyuz

    2013-10-01

    Full Text Available We report the case of a 9-month-old patient presenting for redo aortic arch surgery because of recoarctation. In present case, ascending-to-descending aortic bypass via median sternotomy was performed without cardiopulmonary bypass with good result. In spite of the fact that the different surgical and intervention treatment options of aortic coarctation are quite satisfactory, a certain group of patients need reoperation because of recoarctation. The recoarctation repair of the aorta with the extra-anatomic aortic bypass is considered a low-risk procedure with high success rate.

  11. 34 CFR 300.198 - Continuation of a by-pass.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Continuation of a by-pass. 300.198 Section 300.198... CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.198 Continuation of a by-pass. The Secretary continues a by-pass until the Secretary determines that the SEA, LEA...

  12. 34 CFR 300.192 - Notice of intent to implement a by-pass.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Notice of intent to implement a by-pass. 300.192... EDUCATION OF CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.192 Notice of intent to implement a by-pass. (a) Before taking any final action to implement a by-pass,...

  13. 34 CFR 300.191 - Provisions for services under a by-pass.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Provisions for services under a by-pass. 300.191... EDUCATION OF CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.191 Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults...

  14. Glucagon-like Peptide-1 Protects Pancreatic Beta-cells from Death by Increasing Autophagic Flux and Restoring Lysosomal Function.

    Science.gov (United States)

    Zummo, Francesco P; Cullen, Kirsty S; Honkanen-Scott, Minna; Shaw, James Am; Lovat, Penny E; Arden, Catherine

    2017-02-23

    Studies in animal models of type 2 diabetes have shown that glucagon-like peptide-1 (GLP-1) receptor agonists prevent β-cell loss. Whether GLP-1 mediates β-cell survival via the key lysosomal-mediated process of autophagy is unknown.Here we report that treatment of INS-1E β-cells and primary islets with glucolipotoxicity (0.5mmol/l palmitate, 25mmol/l glucose) increases LC3 II, a marker of autophagy. Further analysis indicates a blockage in autophagic flux associated with lysosomal dysfunction. Accumulation of defective lysosomes leads to lysosomal membrane permeabilisation (LMP) and release of Cathepsin D, which contributes to cell death. Our data further demonstrated defects in autophagic flux and lysosomal staining in human samples of type 2 diabetes. Co-treatment with the GLP-1 receptor agonist exendin-4 reversed the lysosomal dysfunction, relieving the impairment in autophagic flux and further stimulated autophagy. siRNA knockdown showed the restoration of autophagic flux is also essential for the protective effects of exendin-4.Collectively, our data highlights lysosomal dysfunction as a critical mediator of β-cell loss and shows that exendin-4 improves cell survival via restoration of lysosomal function and autophagic flux. Modulation of autophagy / lysosomal homeostasis may thus define a novel therapeutic strategy for type 2 diabetes, with the GLP-1 signalling pathway as a potential focus.

  15. Evidence for lysosomal exocytosis and release of aggrecan-degrading hydrolases from hypertrophic chondrocytes, in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Edward R. Bastow

    2012-02-01

    The abundant proteoglycan, aggrecan, is resorbed from growth plate cartilage during endochondral bone ossification, yet mice with genetically-ablated aggrecan-degrading activity have no defects in bone formation. To account for this apparent anomaly, we propose that lysosomal hydrolases degrade extracellular, hyaluronan-bound aggrecan aggregates in growth plate cartilage, and that lysosomal hydrolases are released from hypertrophic chondrocytes into growth plate cartilage via Ca2+-dependent lysosomal exocytosis. In this study we confirm that hypertrophic chondrocytes release hydrolases via lysosomal exocytosis in vitro and we show in vivo evidence for lysosomal exocytosis in hypertrophic chondrocytes during skeletal development. We show that lysosome-associated membrane protein 1 (LAMP1 is detected at the cell surface following in vitro treatment of epiphyseal chondrocytes with the calcium ionophore, ionomycin. Furthermore, we show that in addition to the lysosomal exocytosis markers, cathepsin D and β-hexosaminidase, ionomycin induces release of aggrecan- and hyaluronan-degrading activity from cultured epiphyseal chondrocytes. We identify VAMP-8 and VAMP7 as v-SNARE proteins with potential roles in lysosomal exocytosis in hypertrophic chondrocytes, based on their colocalisation with LAMP1 at the cell surface in secondary ossification centers in mouse tibiae. We propose that resorbing growth plate cartilage involves release of destructive hydrolases from hypertrophic chondrocytes, via lysosomal exocytosis.

  16. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay-Sachs mouse models.

    Science.gov (United States)

    Timur, Z K; Akyildiz Demir, S; Marsching, C; Sandhoff, R; Seyrantepe, V

    2015-09-01

    Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA(−/−) mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s). These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2in vitro. Neu4(−/−) mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA(−/−) mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA(−/−) Neu1(−/−) and HexA(−/−) Neu4(−/−) Neu1(−/−) mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA(−/−) mice.

  17. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay–Sachs mouse models

    Directory of Open Access Journals (Sweden)

    Z.K. Timur

    2015-09-01

    Full Text Available Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA−/− mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s. These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2 in vitro. Neu4−/− mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA−/− mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA−/−Neu1−/− and HexA−/−Neu4−/−Neu1−/− mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA−/− mice.

  18. Not nanocarbon but dispersant induced abnormality in lysosome in macrophages in vivo

    Science.gov (United States)

    Yudasaka, Masako; Zhang, Minfang; Matsumura, Sachiko; Yuge, Ryota; Ichihashi, Toshinari; Irie, Hiroshi; Shiba, Kiyotaka; Iijima, Sumio

    2015-05-01

    The properties of nanocarbons change from hydrophobic to hydrophilic as a result of coating them with dispersants, typically phospholipid polyethylene glycols, for biological studies. It has been shown that the dispersants remain attached to the nanocarbons when they are injected in mice and influence the nanocarbons’ biodistribution in vivo. We show in this report that the effects of dispersants also appear at the subcellular level in vivo. Carbon nanohorns (CNHs), a type of nanocarbon, were dispersed with ceramide polyethylene glycol (CPEG) and intravenously injected in mice. Histological observations and electron microscopy with energy dispersive x-ray analysis revealed that, in liver and spleen, the lysosome membranes were damaged, and the nanohorns formed a complex with hemosiderin in the lysosomes of the macrophages. It is inferred that the lysosomal membrane was damaged by sphigosine generated as a result of CPEG decomposition, which changed the intra lysosomal conditions, inducing the formation of the CPEG-CNH and hemosiderin complex. For comparison, when glucose was used instead of CPEG, neither the nanohorn-hemosiderin complex nor lysosomal membrane damage was found. Our results suggest that surface functionalization can control the behavior of nancarbons in cells in vivo and thereby improve their suitability for medical applications.

  19. Color reduction of melanin by lysosomal and peroxisomal enzymes isolated from mammalian cells.

    Science.gov (United States)

    Park, Dong Jun; Sekhon, Simranjeet Singh; Yoon, Jihee; Kim, Yang-Hoon; Min, Jiho

    2016-02-01

    Lysosomes and peroxisomes are organelles with many functions in all eukaryotic cells. Lysosomes contain hydrolytic enzymes (lysozyme) that degrade molecules, whereas peroxisomes contain enzymes such as catalase that convert hydrogen peroxide (H2O2) to water and oxygen and neutralize toxicity. In contrast, melanin is known as a helpful element to protect the skin against harmful ultraviolet rays. However, a high quantity of melanin leads to hyperpigmentation or skin cancer in human. New materials have already been discovered to inhibit tyrosinase in melanogenesis; however, melanin reduction does not suggest their preparation. In this study, we report that the color intensity because of melanin decreased by the cellular activation of lysosomes and peroxisomes. An increase in the superficial intensity of lysosome and peroxisome activities of HeLa cells was observed. In addition, a decrease in the amount of melanin has also been observed in mammalian cells without using any other chemical, showing that the process can work in vivo for treating melanin. Therefore, the results of this study indicate that the amount of melanin decreases by the lysosome and peroxisome activity after entering the cells, and functional organelles are effective in color reduction. This mechanism can be used in vivo for treating melanin.

  20. LAMP-2 is required for incorporating syntaxin-17 into autophagosomes and for their fusion with lysosomes.

    Science.gov (United States)

    Hubert, Virginie; Peschel, Andrea; Langer, Brigitte; Gröger, Marion; Rees, Andrew; Kain, Renate

    2016-10-15

    Autophagy is an evolutionarily conserved process used for removing surplus and damaged proteins and organelles from the cytoplasm. The unwanted material is incorporated into autophagosomes that eventually fuse with lysosomes, leading to the degradation of their cargo. The fusion event is mediated by the interaction between the Qa-SNARE syntaxin-17 (STX17) on autophagosomes and the R-SNARE VAMP8 on lysosomes. Cells deficient in lysosome membrane-associated protein-2 (LAMP-2) have increased numbers of autophagosomes but the underlying mechanism is poorly understood. By transfecting LAMP-2-deficient and LAMP-1/2--double-deficient mouse embryonic fibroblasts (MEFs) with a tandem fluorescent-tagged LC3 we observed a failure of fusion between the autophagosomes and the lysosomes that could be rescued by complementation with LAMP-2A. Although we observed no change in expression and localization of VAMP8, its interacting partner STX17 was absent from autophagosomes of LAMP-2-deficient cells. Thus, LAMP-2 is essential for STX17 expression by the autophagosomes and this absence is sufficient to explain their failure to fuse with lysosomes. The results have clear implications for situations associated with a reduction of LAMP-2 expression.

  1. Disruption of lysosome function promotes tumor growth and metastasis in Drosophila.

    Science.gov (United States)

    Chi, Congwu; Zhu, Huanhu; Han, Min; Zhuang, Yuan; Wu, Xiaohui; Xu, Tian

    2010-07-09

    Lysosome function is essential to many physiological processes. It has been suggested that deregulation of lysosome function could contribute to cancer. Through a genetic screen in Drosophila, we have discovered that mutations disrupting lysosomal degradation pathway components contribute to tumor development and progression. Loss-of-function mutations in the Class C vacuolar protein sorting (VPS) gene, deep orange (dor), dramatically promote tumor overgrowth and invasion of the Ras(V12) cells. Knocking down either of the two other components of the Class C VPS complex, carnation (car) and vps16A, also renders Ras(V12) cells capable for uncontrolled growth and metastatic behavior. Finally, chemical disruption of the lysosomal function by feeding animals with antimalarial drugs, chloroquine or monensin, leads to malignant tumor growth of the Ras(V12) cells. Taken together, our data provide evidence for a causative role of lysosome dysfunction in tumor growth and invasion and indicate that members of the Class C VPS complex behave as tumor suppressors.

  2. Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy

    DEFF Research Database (Denmark)

    Patti, M E; McMahon, G; Mun, E C;

    2005-01-01

    was assessed in all three patients. RESULTS: All three patients had evidence of severe postprandial hyperinsulinaemia and hypoglycaemia. In one patient, reversal of gastric bypass was ineffective in reversing hypoglycaemia. All three patients ultimately required partial pancreatectomy for control...

  3. [Psychoprophylaxis in patients after coronary artery bypass graft operations].

    Science.gov (United States)

    Rymaszewska, Joanna; Chładzińska-Kiejna, Sylwia; Górna, Renata; Kustrzycki, Wojciech

    2004-05-01

    The paper presented problems of quality of life and psychosocial functioning of patients following coronary artery bypass grafting operations. Possibilities of psychoprophylactic effects towards these patients and its efficacy were described.

  4. Value of Optical Bypass in Packet Ring Networks

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper firstly examines the value of optical bypass scheme in packet ring networks. An Integer Linear Program (ILP) formulation is presented and analytical results under different traffic patterns are given.

  5. Oil Bypass Filter Technology Performance Evaluation - January 2003 Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Laurence R. Zirker; James E. Francfort

    2003-01-01

    This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

  6. Oil Bypass Filter Technology Performance Evaluation - First Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Zirker, L.R.; Francfort, J.E.

    2003-01-31

    This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

  7. Prolonged successful therapy for hyperinsulinaemic hypoglycaemia after gastric bypass

    DEFF Research Database (Denmark)

    Myint, K S; Greenfield, J R; Farooqi, I S;

    2012-01-01

    Spontaneous hyperinsulinaemic hypoglycaemia following gastric bypass surgery (GBS) is increasingly recognised. However, its pathophysiology remains unclear. Some patients require pancreatectomy. Medical therapy with calcium channel blockers, acarbose and diazoxide has been reported to be beneficial...

  8. Antiplatelet therapy at the time of coronary artery bypass grafting

    DEFF Research Database (Denmark)

    Kremke, Michael; Tang, Mariann; Bak, Mikkel;

    2013-01-01

    OBJECTIVES: The purpose of this multicentre cohort study was to examine the relationship between antiplatelet therapy (APT) at the time of coronary artery bypass grafting (CABG) and postoperative bleeding complications, transfusion requirements and adverse cardiovascular events. METHODS: A matched...

  9. Canals, Bypass Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Bypass Canal'. Data by this publisher are often provided in...

  10. Palliative surgical bypass for unresectable periampullar y carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shivendra Singh; Ajay Kumar Sachdev; Adarsh Chaudhary; Anil Kumar Agarwal

    2008-01-01

    BACKGROUND:Around 60% to 80% of patients with periampullary carcinoma are unresectable either due to distant metastasis or local vascular invasion. With the advancement of endoscopic interventional procedures, the role of surgical bypass has diminished. However, surgical bypass is still appropriate in patients with unresectable disease discovered at the time of surgery. This study was conducted to assess the results of palliative surgical bypass for patients with unresectable periampullary carcinoma at our hospital, a tertiary referral center of Northern India. METHOD:The study group comprised 204 patients who had undergone surgical bypass for advanced periampullary carcinoma over the last 15 years. RESULTS:Between January 1990 and December 2004, 204 patients (128 males, 76 females) consisting of 179 patients with carcinoma of head of the pancreas, 14 patients with ampullary carcinoma, 8 patients with lower end cholangiocarcinoma and 3 patients with duodenal carcinoma underwent surgical bypass. Their average age was 51 years (range 20-78 years). Both biliary and gastric bypasses were done in 158 (77.45%), biliary bypass alone in 37 (18.13%), and gastric bypass alone in 9 (4.32%). Biliary bypass was done by Roux-en-Y hepaticojejunostomy, and gastric bypass by retrocolic gastrojejunostomy. The overall postoperative mortality and morbidity were 0.98%and 26.9%, respectively. The patients who died had undergone previously endoscopic intervention. Complications included wound infection in 12.25% of the patients, bile leak in 5.12%, delayed gastric emptying in 5.38%, ascitic leak from drains in 8.8%, and upper gastrointestinal bleeding in 1.96%. The incidences of wound infection and bile leak both were signiifcantly higher in patients who had had preoperative biliary stenting. None of the patients who had undergone Roux-en-Y hepati-cojejunostomy+retrocolic gastrojejunostomy required any intervention later in their life. CONCLUSIONS:Surgical bypass is a safe procedure with

  11. Night Blindness and Vitamin A Deficiency following Jejunoilieal Bypass Surgery

    OpenAIRE

    Adams, Paul C; Canny, Christopher L.

    1989-01-01

    A 42-year-old man who developed severe night blindness 15 years following jejunoileal bypass surgery for morbid obesity is described. Ophthamological testing, including dark adaptation, electroretinography and serum vitamin A levels, confirmed a diagnosis of vitamin A deficiency. Oral vitamin A 25,000 iu/day for two months resulted in a full recovery of visual deficits. Nutritional vitamin A deficiency is discussed in the context of intestinal bypass surgery.

  12. Severe peripheral neuropathy following gastric bypass surgery for morbid obesity.

    OpenAIRE

    Maryniak, O.

    1984-01-01

    Severe weakness in the limbs developed in a young woman 3 1/2 months after successful gastric bypass surgery for morbid obesity. Electromyography confirmed the clinical impression of generalized axonal polyneuropathy. Vitamin B replacement therapy was started. The gastric bypass was not reversed, and the patient continued to lose weight while undergoing rehabilitation. After 10 months she had almost fully recovered. Her total weight loss was 76 kg. Neuropathy is an uncommon but serious compli...

  13. Association of sex with patency of femorodistal bypass grafts

    DEFF Research Database (Denmark)

    Watson, H R; Schroeder, T V; Simms, M H;

    2000-01-01

    There is evidence for superior patency in infra-inguinal bypass procedures in men compared to women. A large, prospectively planned series was investigated in order to confirm this finding and to determine the origin of this difference in outcome.......There is evidence for superior patency in infra-inguinal bypass procedures in men compared to women. A large, prospectively planned series was investigated in order to confirm this finding and to determine the origin of this difference in outcome....

  14. Bypass Selection for Control of Heat Exchanger Network

    Institute of Scientific and Technical Information of China (English)

    SUN Lin; LUO Xionglin; HOU Benquan; BAI Yujie

    2013-01-01

    Considering the flexibility and controllability of heat exchanger networks (HENs),bypasses are widely used for effective control of process stream target temperatures.However,the optimal location for the bypass is generally difficult to design with the trade-off between controllability and capital investments.In this paper,based on the steady-state model of heat exchanger networks the optimal bypass location was firstly selected by iteratively calculating the non-square Relative Gain Array (ns-RGA).To simplify the calculation process,rules of bypass selection were also proposed.In order to evaluate this method,then,the structural controllability of heat exchanger networks was analyzed.With both the consideration of the controllability and capital investments,the bypasses locations were finally selected.A case study on the HEN in Crude Distillation Unit was presented in which the ns-RGA and structural controllability were used to select bypasses and also to evaluate the results.

  15. One-dimensional Arterial Network Model for Bypass Grafts Assessment

    CERN Document Server

    Ghigo, Arthur; Wang, Xiaofei; Lagrée, Pierre-Yves; Fullana, Jose-Maria

    2016-01-01

    We propose an arterial network model based on 1D blood hemodynamic equations to study the behavior of different vascular surgical bypass grafts in case of an arterial occlusive pathology: an obliteration or stenosis of the iliac artery. We investigate the performances of three different bypass grafts (Aorto-Femoral, Axillo-Femoral and cross-over Femoral) depending on the degree of obliteration of the stenosis. Numerical simulations show that all bypass grafts are efficient since we retrieve in all cases the normal hemodynamics in the stenosed region while ensuring at the same time a global healthy circulation. We analyze in particular the Axillo-Femoral bypass graft by performing hundreds of simulations by varying the values of the Young's modulus [0.1--50 MPa] and the radius [0.01--5 cm] of the bypass graft. We show that the Young's modulus and radius of commercial bypass grafts are optimal in terms of hemodynamic considerations. The numerical findings prove that this approach could be used to optimize or pl...

  16. Progress on Complications of Direct Bypass for Moyamoya Disease

    Science.gov (United States)

    Yu, Jinlu; Shi, Lei; Guo, Yunbao; Xu, Baofeng; Xu, Kan

    2016-01-01

    Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD. PMID:27499690

  17. Progress on Complications of Direct Bypass for Moyamoya Disease.

    Science.gov (United States)

    Yu, Jinlu; Shi, Lei; Guo, Yunbao; Xu, Baofeng; Xu, Kan

    2016-01-01

    Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD.

  18. Characterization of two-pore channel 2 (TPCN2)-mediated Ca2+ currents in isolated lysosomes.

    Science.gov (United States)

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian A

    2010-07-01

    Two-pore channels (TPCNs) have been proposed to form lysosomal Ca(2+) release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca(2+) channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino acid residue in the putative pore region that is crucial for conferring high Ca(2+) selectivity. Our glass chip-based method will provide electrophysiological access not only to lysosomal TPCN channels but also to a broad range of other intracellular ion channels.

  19. Characterization of Two-pore Channel 2 (TPCN2)-mediated Ca2+ Currents in Isolated Lysosomes*

    Science.gov (United States)

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian A.

    2010-01-01

    Two-pore channels (TPCNs) have been proposed to form lysosomal Ca2+ release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca2+ channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino acid residue in the putative pore region that is crucial for conferring high Ca2+ selectivity. Our glass chip-based method will provide electrophysiological access not only to lysosomal TPCN channels but also to a broad range of other intracellular ion channels. PMID:20495006

  20. Guanidinylated neomycin mediates heparan sulfate-dependent transport of active enzymes to lysosomes.

    Science.gov (United States)

    Sarrazin, Stéphane; Wilson, Beth; Sly, William S; Tor, Yitzhak; Esko, Jeffrey D

    2010-07-01

    Guanidinylated neomycin (GNeo) can transport bioactive, high molecular weight cargo into the interior of cells in a process that depends on cell surface heparan sulfate proteoglycans. In this report, we show that GNeo-modified quantum dots bind to cell surface heparan sulfate, undergo endocytosis and eventually reach the lysosomal compartment. An N-hydroxysuccinimide activated ester of GNeo (GNeo-NHS) was prepared and conjugated to two lysosomal enzymes, beta-D-glucuronidase (GUS) and alpha-L-iduronidase. Conjugation did not interfere with enzyme activity and enabled binding of the enzymes to heparin-Sepharose and heparan sulfate on primary human fibroblasts. Cells lacking the corresponding lysosomal enzyme took up sufficient amounts of the conjugated enzymes to restore normal turnover of glycosaminoglycans. The high capacity of proteoglycan-mediated uptake suggests that this method of delivery might be used for enzyme replacement or introduction of foreign enzymes into cells.

  1. The role of VAMP7/TI-VAMP in cell polarity and lysosomal exocytosis in vivo.

    Science.gov (United States)

    Sato, Mahito; Yoshimura, Shinichiro; Hirai, Rika; Goto, Ayako; Kunii, Masataka; Atik, Nur; Sato, Takashi; Sato, Ken; Harada, Reiko; Shimada, Junko; Hatabu, Toshimitsu; Yorifuji, Hiroshi; Harada, Akihiro

    2011-10-01

    VAMP7 or tetanus neurotoxin-insensitive vesicle- associated membrane protein (TI-VAMP) has been proposed to regulate apical transport in polarized epithelial cells, axonal transport in neurons and lysosomal exocytosis. To investigate the function of VAMP7 in vivo, we generated VAMP7 knockout mice. Here, we show that VAMP7 knockout mice are indistinguishable from control mice and display a similar localization of apical proteins in the kidney and small intestine and a similar localization of axonal proteins in the nervous system. Neurite outgrowth of cultured mutant hippocampal neurons was reduced in mutant neurons. However, lysosomal exocytosis was not affected in mutant fibroblasts. Our results show that VAMP7 is required in neurons to extend axons to the full extent. However, VAMP7 does not seem to be required for epithelial cell polarity and lysosomal exocytosis.

  2. Elimination of paternal mitochondria through the lysosomal degradation pathway in C.elegans

    Institute of Scientific and Technical Information of China (English)

    Qinghua Zhou; Haimin Li; Ding Xue

    2011-01-01

    In mammals,the inheritance of mitochondrion and its DNA (mtDNA) is strictly maternal,despite the fact that a sperm can inject up to 100 functional mitochondria into the oocyte during fertilization.The mechanisms responsible for the elimination of the paternal mitochondria remain largely unknown.We report here that this paternal mitochondrial elimination process is conserved in Caenorhabditis elegans,and that the lysosomal pathway actively participates in this process.Molecular and cell biological analyses indicate that in wild-type animals paternal mitoehondria and mtDNA are destroyed within two hours after fertilization.In animals with compromised lysosomes,paternal mitochondria persist until late embryonic stages.Therefore,the lysosomal pathway plays an important role in degrading paternal mitochondria introduced into the oocyte during fertilization.Our study indicates that C.elegans is an excellent animal model for understanding and dissecting this conserved biological process critical for animal development and reproduction.

  3. The inactivation of the sortilin gene leads to a partial disruption of prosaposin trafficking to the lysosomes

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Jibin; Racicott, Jesse [Department of Anatomy and Cell Biology, McGill University, Montreal (Canada); Morales, Carlos R., E-mail: carlos.morales@mcgill.ca [Department of Anatomy and Cell Biology, McGill University, Montreal (Canada)

    2009-11-01

    Lysosomes are intracellular organelles which contain enzymes and activator proteins involved in the digestion and recycling of a variety of cellular and extracellular substances. We have identified a novel sorting receptor, sortilin, which is involved in the lysosomal trafficking of the sphingolipid activator proteins, prosaposin and GM{sub 2}AP, and the soluble hydrolases cathepsin D, cathepsin H, and acid sphingomyelinase. Sortilin belongs to a growing family of receptors with homology to the yeast Vps10 protein, which acts as a lysosomal sorting receptor for carboxypeptidase Y. In this study we examined the effects of the sortilin gene inactivation in mice. The inactivation of this gene did not yield any noticeable lysosomal pathology. To determine the existence of an alternative receptor complementing the sorting function of sortilin, we quantified the concentration of prosaposin in the lysosomes of the nonciliated epithelial cells lining the efferent ducts. These cells were chosen because they express sortilin and have a large number of lysosomes containing prosaposin. In addition, the nonciliated cells are known to endocytose luminal prosaposin that is synthesized and secreted by Sertoli cells into the seminiferous luminal fluids. Consequently, the nonciliated cells are capable of targeting both exogenous and endogenous prosaposin to the lysosomes. Using electron microscope immunogold labeling and quantitative analysis, our results demonstrate that inactivation of the sortilin gene produces a significant decrease of prosaposin in the lysosomes. When luminal prosaposin was excluded from the efferent ducts, the level of prosaposin in lysosomes was even lower in the mutant mice. Nonetheless, a significant amount of prosaposin continues to reach the lysosomal compartment. These results strongly suggest the existence of an alternative receptor that complements the function of sortilin and explains the lack of lysosomal storage disorders in the sortilin

  4. Post-gastric bypass hypoglycaemia: a review.

    Science.gov (United States)

    Shantavasinkul, Prapimporn C; Torquati, Alfonso; Corsino, Leonor

    2016-07-01

    Bariatric surgery is a highly effective treatment for severe obesity, resulting in substantial weight loss and normalizing obesity-related comorbidities. However, long-term consequences can occur, such as postbariatric surgery hypoglycaemia. This is a challenging medical problem, and the number of patients presenting with it has been increasing. Roux-en-Y gastric bypass (RYGB) is the most popular bariatric procedure, and it is the surgery most commonly associated with the development of postbariatric surgery hypoglycaemia. To date, the pathogenesis of this condition has not been completely established. However, various factors - particularly increased postprandial glucagon-like peptide (GLP)-1 secretion - have been considered as crucial mediator. The mechanisms responsible for diabetic remission after bariatric surgery may be responsible for the development of hypoglycaemia, which typically occurs 1-3 h after a meal and is concurrent with inappropriate hyperinsulinaemia. Carbohydrate-rich foods usually provoke hypoglycaemic symptoms, which can typically be alleviated by strict dietary modifications, including carbohydrate restriction and avoidance of high glycaemic index foods and simple sugars. Few patients require further medical intervention, such as medications, but some patients have required a pancreatectomy. Because this option is not always successful, it is no longer routinely recommended. Clinical trials are needed to further determine the pathophysiology of this condition as well as the best diagnostic and treatment approaches for these patients.

  5. Current status of mini-gastric bypass

    Science.gov (United States)

    Mahawar, Kamal K.; Kumar, Parveen; Carr, William RJ; Jennings, Neil; Schroeder, Norbert; Balupuri, Shlok; Small, Peter K.

    2016-01-01

    Mini-gastric bypass (MGP) is a promising bariatric procedure. Tens of thousands of this procedure have been performed throughout the world since Rutledge performed the first procedure in the United States of America in 1997. Several thousands of these have even been documented in the published scientific literature. Despite a proven track record over nearly two decades, this operation continues to polarise the bariatric community. A large number of surgeons across the world have strong objections to this procedure and do not perform it. The risk of symptomatic (bile) reflux, marginal ulceration, severe malnutrition, and long-term risk of gastric and oesophageal cancers are some of the commonly voiced concerns. Despite these expressed fears, several advantages such as technical simplicity, shorter learning curve, ease of revision and reversal, non-inferior weight loss and comorbidity resolution outcomes have prompted some surgeons to advocate a wider adoption of this procedure. This review examines the current status of these controversial aspects in the light of the published academic literature in English. PMID:27251826

  6. Postoperative abdominal complications after cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Dong Guohua

    2012-10-01

    Full Text Available Abstract Background To summarize the diagnostic and therapeutic experiences on the patients who suffered abdominal complications after cardiovascular surgery with cardiopulmonary bypass(CPB. Methods A total of 2349 consecutive patients submitted to cardiovascular surgery with CPB in our hospital from Jan 2004 to Dec 2010 were involved. The clinical data of any abdominal complication, including its incidence, characters, relative risks, diagnostic measures, medical or surgical management and mortality, was retrospectively analyzed. Results Of all the patients, 33(1.4% developed abdominal complications postoperatively, including 11(33.3% cases of paralytic ileus, 9(27.3% of gastrointestinal haemorrhage, 2(6.1% of gastroduodenal ulcer perforation, 2(6.1% of acute calculus cholecystitis, 3(9.1% of acute acalculus cholecystitis, 4(12.1% of hepatic dysfunction and 2(6.1% of ischemia bowel diseases. Of the 33 patients, 26 (78.8% accepted medical treatment and 7 (21.2% underwent subsequent surgical intervention. There were 5(15.2% deaths in this series, which was significantly higher than the overall mortality (2.7%. Positive history of peptic ulcer, advanced ages, bad heart function, preoperative IABP support, prolonged CPB time, low cardiac output and prolonged mechanical ventilation are the risk factors of abdominal complications. Conclusions Abdominal complications after cardiovascular surgery with CPB have a low incidence but a higher mortality. Early detection and prompt appropriate intervention are essential for the outcome of the patients.

  7. Current status of mini-gastric bypass

    Directory of Open Access Journals (Sweden)

    Kamal K Mahawar

    2016-01-01

    Full Text Available Mini-gastric bypass (MGP is a promising bariatric procedure. Tens of thousands of this procedure have been performed throughout the world since Rutledge performed the first procedure in the United States of America in 1997. Several thousands of these have even been documented in the published scientific literature. Despite a proven track record over nearly two decades, this operation continues to polarise the bariatric community. A large number of surgeons across the world have strong objections to this procedure and do not perform it. The risk of symptomatic (bile reflux, marginal ulceration, severe malnutrition, and long-term risk of gastric and oesophageal cancers are some of the commonly voiced concerns. Despite these expressed fears, several advantages such as technical simplicity, shorter learning curve, ease of revision and reversal, non-inferior weight loss and comorbidity resolution outcomes have prompted some surgeons to advocate a wider adoption of this procedure. This review examines the current status of these controversial aspects in the light of the published academic literature in English.

  8. Lysosomal and mitochondrial permeabilization mediates zinc(II) cationic phthalocyanine phototoxicity.

    Science.gov (United States)

    Marino, Julieta; García Vior, María C; Furmento, Verónica A; Blank, Viviana C; Awruch, Josefina; Roguin, Leonor P

    2013-11-01

    In order to find a novel photosensitizer to be used in photodynamic therapy for cancer treatment, we have previously showed that the cationic zinc(II) phthalocyanine named Pc13, the sulfur-linked dye 2,9(10),16(17),23(24)-tetrakis[(2-trimethylammonium) ethylsulfanyl]phthalocyaninatozinc(II) tetraiodide, exerts a selective phototoxic effect on human nasopharynx KB carcinoma cells and induces an apoptotic response characterized by an increase in the activity of caspase-3. Since the activation of an apoptotic pathway by chemotherapeutic agents contributes to the elimination of malignant cells, in this study we investigated the molecular mechanisms underlying the antitumor action of Pc13. We found that after light exposure, Pc13 induced the production of reactive oxygen species (ROS), which are mediating the resultant cytotoxic action on KB cells. ROS led to an early permeabilization of lysosomal membranes as demonstrated by the reduction of lysosome fluorescence with acridine orange and the release of lysosomal proteases to cytosol. Treatment with antioxidants inhibited ROS generation, preserved the integrity of lysosomal membrane and increased cell proliferation in a concentration-dependent manner. Lysosome disruption was followed by mitochondrial depolarization, cytosolic release of cytochrome C and caspases activation. Although no change in the total amount of Bax was observed, the translocation of Bax from cytosol to mitochondria, the cleavage of the pro-apoptotic protein Bid, together with the decrease of the anti-apoptotic proteins Bcl-XL and Bcl-2 indicated the involvement of Bcl-2 family proteins in the induction of the mitochondrial pathway. It was also demonstrated that cathepsin D, but not caspase-8, contributed to Bid cleavage. In conclusion, Pc13-induced cell photodamage is triggered by ROS generation and activation of the mitochondrial apoptotic pathway through the release of lysosomal proteases. In addition, our results also indicated that Pc13 induced

  9. Rapid recycling of Ca2+ between IP3-sensitive stores and lysosomes.

    Directory of Open Access Journals (Sweden)

    Cristina I López Sanjurjo

    Full Text Available Inositol 1,4,5-trisphosphate (IP3 evokes release of Ca2+ from the endoplasmic reticulum (ER, but the resulting Ca2+ signals are shaped by interactions with additional intracellular organelles. Bafilomycin A1, which prevents lysosomal Ca2+ uptake by inhibiting H+ pumping into lysosomes, increased the amplitude of the initial Ca2+ signals evoked by carbachol in human embryonic kidney (HEK cells. Carbachol alone and carbachol in combination with parathyroid hormone (PTH evoke Ca2+ release from distinct IP3-sensitive Ca2+ stores in HEK cells stably expressing human type 1 PTH receptors. Bafilomycin A1 similarly exaggerated the Ca2+ signals evoked by carbachol or carbachol with PTH, indicating that Ca2+ released from distinct IP3-sensitive Ca2+ stores is sequestered by lysosomes. The Ca2+ signals resulting from store-operated Ca2+ entry, whether evoked by thapsigargin or carbachol, were unaffected by bafilomycin A1. Using Gd3+ (1 mM to inhibit both Ca2+ entry and Ca2+ extrusion, HEK cells were repetitively stimulated with carbachol to assess the effectiveness of Ca2+ recycling to the ER after IP3-evoked Ca2+ release. Blocking lysosomal Ca2+ uptake with bafilomycin A1 increased the amplitude of each carbachol-evoked Ca2+ signal without affecting the rate of Ca2+ recycling to the ER. This suggests that Ca2+ accumulated by lysosomes is rapidly returned to the ER. We conclude that lysosomes rapidly, reversibly and selectively accumulate the Ca2+ released by IP3 receptors residing within distinct Ca2+ stores, but not the Ca2+ entering cells via receptor-regulated, store-operated Ca2+ entry pathways.

  10. Lysosomal exoglycosidases in serum and urine of patients with pancreatic adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Anna Stypułkowska

    2010-11-01

    Full Text Available Lysosomal exoglycosidases: N-acetyl-β-D-hexosaminidase (HEX, β-D-galactosidase (GAL, ι-L-fucosidase (FUC and ι-D-mannosidase (MAN modify oligosaccharide chains of glycoconjugates in endoplasmatic reticulum and/or Golgi apparatus and degrade them in lysosomes. In acid environment of lysosome, exoglycosidases degrade oligosaccharide chains of glycoproteins, glycolipids and glycosaminoglycans by eliminating single sugars from the edges of oligosaccharide chains. Neoplasms change biochemical processes in tissues and may significantly change the activity of many enzymes including the activity of lysosomal exoglycosidasses in serum and urine of persons with neoplasmatic diseases. The aim of the present paper was evaluation the activity of HEX, GAL, FUC and MAN in serum and urine of patients with pancreatic adenocarcinoma. Serum and urine samples were collected from 15 patients with adenocarcinoma of the pancreas and 15 healthy persons. The activity of lysosomal exoglycosidases was determined by the method of Marciniak et al. adapted to serum and urine of patients with adenocarcinoma of the pancreas. Our results indicate significant decrease in activity of GAL (p=0.037 in serum of patients with pancreatic adenocarcinoma, significant increase in activity of HEX (p<0.001 and FUC (p=0.027 in serum, and HEX (p=0.003 in urine, as well as significant decrease of FUC (p=0.016 and MAN (p=0.029 in urine o patients with adenocarcinoma of the pancreas, in comparison to the control group. Increase in activity of some lysosomal enzymes in serum and urine of pancreatic adenocarcinoma patients, may indicate on destruction of pancreatic tissue by pancreatic adenocarcinoma. Determination of the HEX, GAL, FUC and MAN in serum and urine may be useful in diagnostics of pancreatic adenocarcinoma.

  11. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage.

    Directory of Open Access Journals (Sweden)

    Corinna Hiller

    2014-04-01

    Full Text Available African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I-II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I-II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective

  12. SUrgical versus PERcutaneous Bypass: SUPERB-trial; Heparin-bonded endoluminal versus surgical femoro-popliteal bypass: study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Lensvelt, M.M.A.; Holewijn, S.; Fritschy, W.M.; Wikkeling, O.R.; Walraven, L.A. van; Wallis de Vries, B.M.; Zeebregts, C.J.A.; Reijnen, M.M.P.J.

    2011-01-01

    BACKGROUND: Endovascular treatment options for the superficial femoral artery are evolving rapidly. For long lesions, the venous femoropopliteal bypass considered to be superior above the prosthetic bypass. An endoluminal bypass, however, may provide equal patency rates compared to the prosthetic ab

  13. SUrgical versus PERcutaneous Bypass : SUPERB-trial; Heparin-bonded endoluminal versus surgical femoro-popliteal bypass: study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Lensvelt, Mare M. A.; Holewijn, Suzanne; Fritschy, Wilbert M.; Wikkeling, Otmar R. M.; van Walraven, Laurens A.; de Vries, Bas M. Wallis; Zeebregts, Clark J.; Reijnen, Michel M. P. J.

    2011-01-01

    Background: Endovascular treatment options for the superficial femoral artery are evolving rapidly. For long lesions, the venous femoropopliteal bypass considered to be superior above the prosthetic bypass. An endoluminal bypass, however, may provide equal patency rates compared to the prosthetic ab

  14. Lysosomal membrane stability of the mussel, Mytilus galloprovincialis (L.), as a biomarker of tributyltin exposure.

    Science.gov (United States)

    Okoro, Hussein K; Snyman, Reinette G; Fatoki, Olalekan S; Adekola, Folahan A; Ximba, Bhekumusa J; Slabber, Michelle Y

    2015-05-01

    The effect of tributyltin (TBT) on the stability of hemocytic lysosome membranes of the mussel, Mytilus galloprovincialis, and the use thereof as a biomarker of TBT-induced stress, was investigated. Mussels were exposed to 0.1 and 1.0 µg/L tributyltin respectively for 4 weeks. Lysosomal membrane stability of hemocytes was tested weekly by means of the neutral red retention time (NRRT) assay, after which the mussel samples were analyzed for TBT content. The two exposed groups exhibited significantly increased (p galloprovincialis.

  15. Characterization of Two-pore Channel 2 (TPCN2)-mediated Ca2+ Currents in Isolated Lysosomes*

    OpenAIRE

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian A.

    2010-01-01

    Two-pore channels (TPCNs) have been proposed to form lysosomal Ca2+ release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca2+ channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino ...

  16. Impact of high cholesterol in a Parkinson's disease model: Prevention of lysosomal leakage versus stimulation of α-synuclein aggregation.

    Science.gov (United States)

    Eriksson, Ida; Nath, Sangeeta; Bornefall, Per; Giraldo, Ana Maria Villamil; Öllinger, Karin

    2017-01-16

    Parkinson's disease is characterized by accumulation of intraneuronal cytoplasmic inclusions, Lewy bodies, which mainly consist of aggregated α-synuclein. Controversies exist as to whether high blood cholesterol is a risk factor for the development of the disease and whether statin treatment could have a protective effect. Using a model system of BE(2)-M17 neuroblastoma cells treated with the neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)), we found that MPP(+)-induced cell death was accompanied by cholesterol accumulation in a lysosomal-like pattern in pre-apoptotic cells. To study the effects of lysosomal cholesterol accumulation, we increased lysosomal cholesterol through pre-treatment with U18666A and found delayed leakage of lysosomal contents into the cytosol, which reduced cell death. This suggests that increased lysosomal cholesterol is a stress response mechanism to protect lysosomal membrane integrity in response to early apoptotic stress. However, high cholesterol also stimulated the accumulation of α-synuclein. Treatment with the cholesterol-lowering drug lovastatin reduced MPP(+)-induced cell death by inhibiting the production of reactive oxygen species, but did not prevent lysosomal cholesterol increase nor affect α-synuclein accumulation. Our study indicates a dual role of high cholesterol in Parkinson's disease, in which it acts both as a protector against lysosomal membrane permeabilization and as a stimulator of α-synuclein accumulation.

  17. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro.

    Science.gov (United States)

    Canfrán-Duque, Alberto; Barrio, Luis C; Lerma, Milagros; de la Peña, Gema; Serna, Jorge; Pastor, Oscar; Lasunción, Miguel A; Busto, Rebeca

    2016-03-18

    First- and second-generation antipsychotics (FGAs and SGAs, respectively), have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL)-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanineperchlorate (DiI)-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2) and LBPA (lysobisphosphatidic acid), which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1) and coatomer subunit β (β-COP) were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes' internal milieu induced by haloperidol affects lysosomal functionality.

  18. Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.

    Science.gov (United States)

    Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

    2011-07-01

    The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.

  19. Iron content and acid phosphatase activity in hepatic parenchymal lysosomes of patients with hemochromatosis before and after phlebotomy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cleton, M.I.; de Bruijn, W.C.; van Blokland, W.T.; Marx, J.J.; Roelofs, J.M.; Rademakers, L.H.

    1988-03-01

    Lysosomal structures in liver parenchymal cells of 3 patients with iron overload and of 3 subjects without iron-storage disorders were investigated. A combination of enzyme cytochemistry--with cerium as a captive ion to demonstrate lysosomal acid phosphatase activity--and electron probe X-ray microanalysis (EPMA) was used. We were able (1) to define and quantify lysosomal structures as lysosomes, siderosomes, or residual bodies, (2) to quantify the amount of iron and cerium simultaneously in these structures, and (3) to evaluate a possible relation between iron storage and enzyme activity. With histopathologically increased iron storage, the number of siderosomes had increased at the cost of lysosomes, with a corresponding increase in acid phosphatase activity in both organelles. In histopahtologically severe iron overload, however, acid phosphatase activity was low or not detectable and most of the iron was stored in residual bodies. After phlebotomy treatment, the number of siderosomes had decreased in favor of the lysosomes, approaching values obtained in control subjects, and acid phosphatase activity was present in all iron-containing structures. In this way a relationship between iron storage and enzyme activity was established. The iron content of the individual lysosomal structures per unit area had increased with histopathologically increased iron storage and had decreased after phlebotomy treatment. From this observation, it is concluded that the iron status of the patient is not only reflected by the amount of iron-containing hepatocytes but, as well, by the iron content lysosomal unit area.

  20. The Possible "Proton Sponge " Effect of Polyethylenimine (PEI) Does Not Include Change in Lysosomal pH

    DEFF Research Database (Denmark)

    Søndergaard, Rikke Vicki; Mattebjerg, Maria Ahlm; Henriksen, Jonas Rosager;

    2013-01-01

    is still elusive. The "proton sponge " hypothesis remains the most generally accepted mechanism, although it is heavily debated. This hypothesis is associated with the large buffering capacity of PEI and other polycations, which has been interpreted to cause an increase in lysosomal pH even though...... no conclusive proof has been provided. In the present study, we have used a nanoparticle pH sensor that was developed for pH measurements in the endosomal/lysosomal pathway. We have carried out quantitative measurements of lysosomal pH as a function of PEI content and correlate the results to the "proton sponge...... " hypothesis. Our measurements show that PEI does not induce change in lysosomal pH as previously suggested and quantification of PEI concentrations in lysosomes makes it uncertain that the "proton sponge " effect is the dominant mechanism of polyplex escape.Molecular Therapy (2012); doi:10.1038/mt.2012.185....

  1. Role of lysosomal enzymes released by alveolar macrophages in the pathogenesis of the acute phase of hypersensitivity pneumonitis

    Directory of Open Access Journals (Sweden)

    J. L. Pérez-Arellano

    1995-01-01

    Full Text Available Hydrolytic enzymes are the major constituents of alveolar macrophages (AM and have been shown to be involved in many aspects of the inflammatory pulmonary response. The aim of this study was to evaluate the role of lysosomal enzymes in the acute phase of hypersensitivity pneumonitis (HPs. An experimental study on AM lysosomal enzymes of an HP-guinea-pig model was performed. The results obtained both in vivo and in vitro suggest that intracellular enzymatic activity decrease is, at least partly, due to release of lysosomal enzymes into the medium. A positive but slight correlation was found between extracellular lysosomal activity and four parameters of lung lesion (lung index, bronchoalveolar fluid total (BALF protein concentration, BALF LDH and BALF alkaline phosphatase activities. All the above findings suggest that the AM release of lysosomal enzymes during HP is a factor involved, although possibly not the only one, in the pulmonary lesions appearing in this disease.

  2. Annular MHD Physics for Turbojet Energy Bypass

    Science.gov (United States)

    Schneider, Steven J.

    2011-01-01

    The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

  3. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Directory of Open Access Journals (Sweden)

    Rita-Eva Varga

    2015-08-01

    Full Text Available Hereditary spastic paraplegia (HSP is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs. Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  4. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Science.gov (United States)

    Varga, Rita-Eva; Khundadze, Mukhran; Damme, Markus; Nietzsche, Sandor; Hoffmann, Birgit; Stauber, Tobias; Koch, Nicole; Hennings, J Christopher; Franzka, Patricia; Huebner, Antje K; Kessels, Michael M; Biskup, Christoph; Jentsch, Thomas J; Qualmann, Britta; Braulke, Thomas; Kurth, Ingo; Beetz, Christian; Hübner, Christian A

    2015-08-01

    Hereditary spastic paraplegia (HSP) is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs). Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  5. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11

    Science.gov (United States)

    Varga, Rita-Eva; Khundadze, Mukhran; Damme, Markus; Nietzsche, Sandor; Hoffmann, Birgit; Stauber, Tobias; Koch, Nicole; Hennings, J. Christopher; Franzka, Patricia; Huebner, Antje K.; Kessels, Michael M.; Biskup, Christoph; Jentsch, Thomas J.; Qualmann, Britta; Braulke, Thomas; Kurth, Ingo; Beetz, Christian; Hübner, Christian A.

    2015-01-01

    Hereditary spastic paraplegia (HSP) is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs). Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice. PMID:26284655

  6. TPC1 Has Two Variant Isoforms, and Their Removal Has Different Effects on Endo-Lysosomal Functions Compared to Loss of TPC2

    OpenAIRE

    Ruas, Margarida; Chuang, Kai-Ting; Davis, Lianne C.; Al-Douri, Areej; Tynan, Patricia W.; Tunn, Ruth; Teboul, Lydia; Galione, Antony; Parrington, John

    2014-01-01

    Organelle ion homeostasis within the endo-lysosomal system is critical for physiological functions. Two-pore channels (TPCs) are cation channels that reside in endo-lysosomal organelles, and overexpression results in endo-lysosomal trafficking defects. However, the impact of a lack of TPC expression on endo-lysosomal trafficking is unknown. Here, we characterize Tpcn1 expression in two transgenic mouse lines (Tpcn1 XG716 and Tpcn1 T159) and show expression of a novel evolutionarily conserved ...

  7. Phototoxic effects of lysosome-associated genetically encoded photosensitizer KillerRed

    Science.gov (United States)

    Serebrovskaya, Ekaterina O.; Ryumina, Alina P.; Boulina, Maria E.; Shirmanova, Marina V.; Zagaynova, Elena V.; Bogdanova, Ekaterina A.; Lukyanov, Sergey A.; Lukyanov, Konstantin A.

    2014-07-01

    KillerRed is a unique phototoxic red fluorescent protein that can be used to induce local oxidative stress by green-orange light illumination. Here we studied phototoxicity of KillerRed targeted to cytoplasmic surface of lysosomes via fusion with Rab7, a small GTPase that is known to be attached to membranes of late endosomes and lysosomes. It was found that lysosome-associated KillerRed ensures efficient light-induced cell death similar to previously reported mitochondria- and plasma membrane-localized KillerRed. Inhibitory analysis demonstrated that lysosomal cathepsins play an important role in the manifestation of KillerRed-Rab7 phototoxicity. Time-lapse monitoring of cell morphology, membrane integrity, and nuclei shape allowed us to conclude that KillerRed-Rab7-mediated cell death occurs via necrosis at high light intensity or via apoptosis at lower light intensity. Potentially, KillerRed-Rab7 can be used as an optogenetic tool to direct target cell populations to either apoptosis or necrosis.

  8. Lysosomal-associated transmembrane protein 5 (LAPTM5 is a molecular partner of CD1e.

    Directory of Open Access Journals (Sweden)

    Catherine Angénieux

    Full Text Available The CD1e protein participates in the presentation of lipid antigens in dendritic cells. Its transmembrane precursor is transported to lysosomes where it is cleaved into an active soluble form. In the presence of bafilomycin, which inhibits vacuolar ATPase and consequently the acidification of endosomal compartments, CD1e associates with a 27 kD protein. In this work, we identified this molecular partner as LAPTM5. The latter protein and CD1e colocalize in trans-Golgi and late endosomal compartments. The quantity of LAPTM5/CD1e complexes increases when the cells are treated with bafilomycin, probably due to the protection of LAPTM5 from lysosomal proteases. Moreover, we could demonstrate that LAPTM5/CD1e association occurs under physiological conditions. Although LAPTM5 was previously shown to act as a platform recruiting ubiquitin ligases and facilitating the transport of receptors to lysosomes, we found no evidence that LATPM5 controls either CD1e ubiquitination or the generation of soluble lysosomal CD1e proteins. Notwithstanding these last observations, the interaction of LAPTM5 with CD1e and their colocalization in antigen processing compartments both suggest that LAPTM5 might influence the role of CD1e in the presentation of lipid antigens.

  9. Lysosomal Enzyme Glucocerebrosidase Protects against Aβ1-42 Oligomer-Induced Neurotoxicity

    Science.gov (United States)

    Kam, Tae-In; Yun, Seungpil; Kim, Sangjune; Park, Hyejin; Hwang, Heehong; Pletnikova, Olga; Troncoso, Juan C.; Dawson, Valina L.; Dawson, Ted M.; Ko, Han Seok

    2015-01-01

    Glucocerebrosidase (GCase) functions as a lysosomal enzyme and its mutations are known to be related to many neurodegenerative diseases, including Gaucher’s disease (GD), Parkinson’s disease (PD), and Dementia with Lewy Bodies (DLB). However, there is little information about the role of GCase in the pathogenesis of Alzheimer’s disease (AD). Here we demonstrate that GCase protein levels and enzyme activity are significantly decreased in sporadic AD. Moreover, Aβ1–42 oligomer treatment results in neuronal cell death that is concomitant with decreased GCase protein levels and enzyme activity, as well as impairment in lysosomal biogenesis and acidification. Importantly, overexpression of GCase promotes the lysosomal degradation of Aβ1–42 oligomers, restores the lysosomal impairment, and protects against the toxicity in neurons treated with Aβ1–42 oligomers. Our findings indicate that a deficiency of GCase could be involved in progression of AD pathology and suggest that augmentation of GCase activity may be a potential therapeutic option for the treatment of AD. PMID:26629917

  10. Lysosomal Enzyme Glucocerebrosidase Protects against Aβ1-42 Oligomer-Induced Neurotoxicity.

    Directory of Open Access Journals (Sweden)

    Seulah Choi

    Full Text Available Glucocerebrosidase (GCase functions as a lysosomal enzyme and its mutations are known to be related to many neurodegenerative diseases, including Gaucher's disease (GD, Parkinson's disease (PD, and Dementia with Lewy Bodies (DLB. However, there is little information about the role of GCase in the pathogenesis of Alzheimer's disease (AD. Here we demonstrate that GCase protein levels and enzyme activity are significantly decreased in sporadic AD. Moreover, Aβ1-42 oligomer treatment results in neuronal cell death that is concomitant with decreased GCase protein levels and enzyme activity, as well as impairment in lysosomal biogenesis and acidification. Importantly, overexpression of GCase promotes the lysosomal degradation of Aβ1-42 oligomers, restores the lysosomal impairment, and protects against the toxicity in neurons treated with Aβ1-42 oligomers. Our findings indicate that a deficiency of GCase could be involved in progression of AD pathology and suggest that augmentation of GCase activity may be a potential therapeutic option for the treatment of AD.

  11. Lysosomal Acid Lipase Activity Is Reduced Both in Cryptogenic Cirrhosis and in Cirrhosis of Known Etiology.

    Directory of Open Access Journals (Sweden)

    Umberto Vespasiani-Gentilucci

    Full Text Available Liver cirrhosis is characterized by a severe acquired reduction of LAL-activity, the precise causes and consequences of which need to be further addressed. DBS-determined lysosomal enzyme activities seem to be affected by white blood cell and platelet counts, and the specificity of these tests can be reduced when applied to determined populations, such as cirrhotics.

  12. Transcriptional control of the autophagy-lysosome system in pancreatic cancer

    Science.gov (United States)

    Perera, Rushika M.; Stoykova, Svetlana; Nicolay, Brandon N.; Ross, Kenneth N.; Fitamant, Julien; Boukhali, Myriam; Lengrand, Justine; Deshpande, Vikram; Selig, Martin K.; Ferrone, Cristina R.; Settleman, Jeff; Stephanopoulos, Gregory; Dyson, Nicholas J.; Zoncu, Roberto; Ramaswamy, Sridhar; Haas, Wilhelm; Bardeesy, Nabeel

    2016-01-01

    Activation of cellular stress response pathways to maintain metabolic homeostasis is emerging as a critical growth and survival mechanism in many cancers1. The pathogenesis of pancreatic ductal adenocarcinoma (PDA) requires high levels of autophagy2–4, a conserved self-degradative process5. However, the regulatory circuits that activate autophagy and reprogram PDA cell metabolism are unknown. We now show that autophagy induction in PDA occurs as part of a broader transcriptional program that coordinates activation of lysosome biogenesis and function, and nutrient scavenging, mediated by the MiT/TFE family transcription factors. In PDA cells, the MiT/TFE proteins6 – MITF, TFE3 and TFEB – are decoupled from regulatory mechanisms that control their cytoplasmic retention. Increased nuclear import in turn drives the expression of a coherent network of genes that induce high levels of lysosomal catabolic function essential for PDA growth. Unbiased global metabolite profiling reveals that MiT/TFE-dependent autophagy-lysosomal activation is specifically required to maintain intracellular amino acid (AA) pools. These results identify the MiT/TFE transcription factors as master regulators of metabolic reprogramming in pancreatic cancer and demonstrate activation of clearance pathways converging on the lysosome as a novel hallmark of aggressive malignancy. PMID:26168401

  13. Two-photon fluorescence probes for imaging of mitochondria and lysosomes.

    Science.gov (United States)

    Yang, Wanggui; Chan, Pui Shan; Chan, Miu Shan; Li, King Fai; Lo, Pik Kwan; Mak, Nai Ki; Cheah, Kok Wai; Wong, Man Shing

    2013-04-28

    Novel biocompatible cyanines show not only a very large two-photon cross-section of up to 5130 GM at 910 nm in aqueous medium for high-contrast and -brightness two-photon fluorescence live cell imaging but also highly selective subcellular localization properties including localization of mitochondria and lysosomes.

  14. Histopathologic correlates of radial stripes on MR images in lysosomal storage disorders.

    NARCIS (Netherlands)

    Voorn, J.P. van der; Pouwels, P.J.; Kamphorst, W.; Powers, J.M.; Lammens, M.M.Y.; Barkhof, F.; Knaap, M.S. van der

    2005-01-01

    BACKGROUND AND PURPOSE: Radially oriented hypointense stripes in hyperintense cerebral white matter are recognized on T2-weighted images of certain lysosomal storage disorders. We compared in vivo and postmortem MR imaging with histopathologic findings in three patients with metachromatic leukodystr

  15. Brucella suis-Impaired Specific Recognition of Phagosomes by Lysosomes due to Phagosomal Membrane Modifications

    Science.gov (United States)

    Naroeni, Aroem; Jouy, Nicolas; Ouahrani-Bettache, Safia; Liautard, Jean-Pierre; Porte, Françoise

    2001-01-01

    Brucella species are gram-negative, facultatively intracellular bacteria that infect humans and animals. These organisms can survive and replicate within a membrane-bound compartment in phagocytic and nonprofessional phagocytic cells. Inhibition of phagosome-lysosome fusion has been proposed as a mechanism for intracellular survival in both types of cells. However, the biochemical mechanisms and microbial factors implicated in Brucella maturation are still completely unknown. We developed two different approaches in an attempt to gain further insight into these mechanisms: (i) a fluorescence microscopy analysis of general intracellular trafficking on whole cells in the presence of Brucella and (ii) a flow cytometry analysis of in vitro reconstitution assays showing the interaction between Brucella suis-containing phagosomes and lysosomes. The fluorescence microscopy results revealed that fusion properties of latex bead-containing phagosomes with lysosomes were not modified in the presence of live Brucella suis in the cells. We concluded that fusion inhibition was restricted to the pathogen phagosome and that the host cell fusion machinery was not altered by the presence of live Brucella in the cell. By in vitro reconstitution experiments, we observed a specific association between killed B. suis-containing phagosomes and lysosomes, which was dependent on exogenously supplied cytosol, energy, and temperature. This association was observed with killed bacteria but not with live bacteria. Hence, this specific recognition inhibition seemed to be restricted to the pathogen phagosomal membrane, as noted in the in vivo experiments. PMID:11119541

  16. AP-3 and Rabip4' coordinately regulate spatial distribution of lysosomes.

    Directory of Open Access Journals (Sweden)

    Viorica Ivan

    Full Text Available The RUN and FYVE domain proteins rabip4 and rabip4' are encoded by RUFY1 and differ in a 108 amino acid N-terminal extension in rabip4'. Their identical C terminus binds rab5 and rab4, but the function of rabip4s is incompletely understood. We here found that silencing RUFY1 gene products promoted outgrowth of plasma membrane protrusions, and polarized distribution and clustering of lysosomes at their tips. An interactor screen for proteins that function together with rabip4' yielded the adaptor protein complex AP-3, of which the hinge region in the β3 subunit bound directly to the FYVE domain of rabip4'. Rabip4' colocalized with AP-3 on a tubular subdomain of early endosomes and the extent of colocalization was increased by a dominant negative rab4 mutant. Knock-down of AP-3 had an ever more dramatic effect and caused accumulation of lysosomes in protrusions at the plasma membrane. The most peripheral lysosomes were localized beyond microtubules, within the cortical actin network. Our results uncover a novel function for AP-3 and rabip4' in regulating lysosome positioning through an interorganellar pathway.

  17. Cancer cell injury by cytotoxins from cobra venom is mediated through lysosomal damage.

    Science.gov (United States)

    Feofanov, Alexei V; Sharonov, George V; Astapova, Maria V; Rodionov, Dmitriy I; Utkin, Yuriy N; Arseniev, Alexander S

    2005-08-15

    Cytotoxins from cobra venom are known to manifest cytotoxicity in various cell types. It is widely accepted that the plasma membrane is a target of cytotoxins, but the mechanism of their action remains obscure. Using the confocal spectral imaging technique, we show for the first time that cytotoxins from cobra venom penetrate readily into living cancer cells and accumulate markedly in lysosomes. Cytotoxins CT1 and CT2 from Naja oxiana, CT3 from Naja kaouthia and CT1 from Naja haje are demonstrated to possess this property with respect to human lung adenocarcinoma A549 and promyelocytic leukaemia HL60 cells. Immobilized plasma membrane binding accompanies the internalization of CT3 from Naja kaouthia in the HL60 cells, but it is very weak for other cytotoxins. Detectable membrane binding is not a property of any of the cytotoxins tested in A549 cells. The kinetics and concentration-dependence of cytotoxin accumulation in lysosomes correlate well with their cytotoxic effects. On the basis of the results obtained, we propose that lysosomes are a primary target of the lytic action of cytotoxins. Plasma membrane permeabilization seems to be a downstream event relative to lysosome rupture. Direct damage to the plasma membrane may be a complementary mechanism, but its relative contribution to the cytotoxic action depends on the cytotoxin structure and cell type.

  18. Frontotemporal dementia caused by CHMP2B mutation is characterised by neuronal lysosomal storage pathology

    DEFF Research Database (Denmark)

    Clayton, Emma L.; Mizielinska, Sarah; Edgar, James R.;

    2015-01-01

    Mutations in the charged multivesicular body protein 2B (CHMP2B) cause frontotemporal dementia (FTD). We report that mice which express FTD-causative mutant CHMP2B at physiological levels develop a novel lysosomal storage pathology characterised by large neuronal autofluorescent aggregates. The a...

  19. Lysosomal acid lipase deficiency--an under-recognized cause of dyslipidaemia and liver dysfunction.

    Science.gov (United States)

    Reiner, Željko; Guardamagna, Ornella; Nair, Devaki; Soran, Handrean; Hovingh, Kees; Bertolini, Stefano; Jones, Simon; Ćorić, Marijana; Calandra, Sebastiano; Hamilton, John; Eagleton, Terence; Ros, Emilio

    2014-07-01

    Lysosomal acid lipase deficiency (LAL-D) is a rare autosomal recessive lysosomal storage disease caused by deleterious mutations in the LIPA gene. The age at onset and rate of progression vary greatly and this may relate to the nature of the underlying mutations. Patients presenting in infancy have the most rapidly progressive disease, developing signs and symptoms in the first weeks of life and rarely surviving beyond 6 months of age. Children and adults typically present with some combination of dyslipidaemia, hepatomegaly, elevated transaminases, and microvesicular hepatosteatosis on biopsy. Liver damage with progression to fibrosis, cirrhosis and liver failure occurs in a large proportion of patients. Elevated low-density lipoprotein cholesterol levels and decreased high-density lipoprotein cholesterol levels are common features, and cardiovascular disease may manifest as early as childhood. Given that these clinical manifestations are shared with other cardiovascular, liver and metabolic diseases, it is not surprising that LAL-D is under-recognized in clinical practice. This article provides practical guidance to lipidologists, endocrinologists, cardiologists and hepatologists on how to recognize individuals with this life-limiting disease. A diagnostic algorithm is proposed with a view to achieving definitive diagnosis using a recently developed blood test for lysosomal acid lipase. Finally, current management options are reviewed in light of the ongoing development of enzyme replacement therapy with sebelipase alfa (Synageva BioPharma Corp., Lexington, MA, USA), a recombinant human lysosomal acid lipase enzyme.

  20. Identification of cytoskeleton-associated proteins essential for lysosomal stability and survival of human cancer cells

    DEFF Research Database (Denmark)

    Groth-Pedersen, Line; Aits, Sonja; Corcelle-Termeau, Elisabeth

    2012-01-01

    Microtubule-disturbing drugs inhibit lysosomal trafficking and induce lysosomal membrane permeabilization followed by cathepsin-dependent cell death. To identify specific trafficking-related proteins that control cell survival and lysosomal stability, we screened a molecular motor siRNA library...... in human MCF7 breast cancer cells. SiRNAs targeting four kinesins (KIF11/Eg5, KIF20A, KIF21A, KIF25), myosin 1G (MYO1G), myosin heavy chain 1 (MYH1) and tropomyosin 2 (TPM2) were identified as effective inducers of non-apoptotic cell death. The cell death induced by KIF11, KIF21A, KIF25, MYH1 or TPM2 si......), increased dextran accumulation (KIF20A), or reduced autophagic flux (MYO1G, MYH1). Importantly, all seven siRNAs also killed human cervix cancer (HeLa) and osteosarcoma (U-2-OS) cells and sensitized cancer cells to other lysosome-destabilizing treatments, i.e. photo-oxidation, siramesine, etoposide...

  1. Drosophila Vps16A is required for trafficking to lysosomes and biogenesis of pigment granules.

    Science.gov (United States)

    Pulipparacharuvil, Suprabha; Akbar, Mohammed Ali; Ray, Sanchali; Sevrioukov, Evgueny A; Haberman, Adam S; Rohrer, Jack; Krämer, Helmut

    2005-08-15

    Mutations that disrupt trafficking to lysosomes and lysosome-related organelles cause multiple diseases, including Hermansky-Pudlak syndrome. The Drosophila eye is a model system for analyzing such mutations. The eye-color genes carnation and deep orange encode two subunits of the Vps-C protein complex required for endosomal trafficking and pigment-granule biogenesis. Here we demonstrate that dVps16A (CG8454) encodes another Vps-C subunit. Biochemical experiments revealed a specific interaction between the dVps16A C-terminus and the Sec1/Munc18 homolog Carnation but not its closest homolog, dVps33B. Instead, dVps33B interacted with a related protein, dVps16B (CG18112). Deep orange bound both Vps16 homologs. Like a deep orange null mutation, eye-specific RNAi-induced knockdown of dVps16A inhibited lysosomal delivery of internalized ligands and interfered with biogenesis of pigment granules. Ubiquitous knockdown of dVps16A was lethal. Together, these findings demonstrate that Drosophila Vps16A is essential for lysosomal trafficking. Furthermore, metazoans have two types of Vps-C complexes with non-redundant functions.

  2. Photovoltaic-module bypass-diode encapsulation. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    1983-06-20

    The design and processing techniques necessary to incorporate bypass diodes within the module encapsulant are presented in this annual report. A comprehensive survey of available pad-mounted PN junction and Schottky diodes led to the selection of Semicon PN junction diode cells for this application. Diode junction-to-heat spreader thermal resistance measurements, performed on a variety of mounted diode chip types and sizes, have yielded values which are consistently below 1/sup 0/C per watt, but show some instability when thermally cycled over the temperature range from -40 to 150/sup 0/C. Based on the results of a detailed thermal analysis, which covered the range of bypass currents from 2 to 20 amperes, three representative experimental modules, each incorporating integral bypass diode/heat spreader assemblies of various sizes, were designed and fabricated. Thermal testing of these modules has enabled the formation of a recommended heat spreader plate sizing relationship. The production cost of three encapsulated bypass diode/heat spreader assemblies were compared with similarly rated externally-mounted packaged diodes. An assessment of bypass diode reliability, which relies heavily on rectifying diode failure rate data, leads to the general conclusion that, when proper designed and installed, these devices will improve the overall reliability of a terrestrial array over a 20 year design lifetime.

  3. Lysine suppresses protein degradation through autophagic-lysosomal system in C2C12 myotubes.

    Science.gov (United States)

    Sato, Tomonori; Ito, Yoshiaki; Nedachi, Taku; Nagasawa, Takashi

    2014-06-01

    Muscle mass is determined between protein synthesis and protein degradation. Reduction of muscle mass leads to bedridden condition and attenuation of resistance to diseases. Moreover, bedridden condition leads to additional muscle loss due to disuse muscle atrophy. In our previous study (Sato et al. 2013), we showed that administered lysine (Lys), one of essential amino acid, suppressed protein degradation in skeletal muscle. In this study, we investigated that the mechanism of the suppressive effects of Lys on skeletal muscle proteolysis in C2C12 cell line. C2C12 myotubes were incubated in the serum-free medium containing 10 mM Lys or 20 mM Lys, and myofibrillar protein degradation was determined by the rates of 3-methylhistidine (MeHis) release from the cells. The mammalian target of rapamycin (mTOR) activity from the phosphorylation levels of p70-ribosormal protein S6 kinase 1 and eIF4E-binding protein 1 and the autophagic-lysosomal system activity from the ratio of LC3-II/I in C2C12 myotubes stimulated by 10 mM Lys for 0-3 h were measured. The rates of MeHis release were markedly reduced by addition of Lys. The autophagic-lysosomal system activity was inhibited upon 30 min of Lys supplementation. The activity of mTOR was significantly increased upon 30 min of Lys supplementation. The suppressive effect of Lys on the proteolysis by the autophagic-lysosomal system was maintained partially when mTOR activity was inhibited by 100 nM rapamycin, suggesting that some regulator other than mTOR signaling, for example, Akt, might also suppress the autophagic-lysosomal system. From these results, we suggested that Lys suppressed the activity of the autophagic-lysosomal system in part through activation of mTOR and reduced myofibrillar protein degradation in C2C12 myotubes.

  4. Glucolipotoxicity diminishes cardiomyocyte TFEB and inhibits lysosomal autophagy during obesity and diabetes.

    Science.gov (United States)

    Trivedi, Purvi C; Bartlett, Jordan J; Perez, Lester J; Brunt, Keith R; Legare, Jean Francois; Hassan, Ansar; Kienesberger, Petra C; Pulinilkunnil, Thomas

    2016-12-01

    Impaired cardiac metabolism in the obese and diabetic heart leads to glucolipotoxicity and ensuing cardiomyopathy. Glucolipotoxicity causes cardiomyocyte injury by increasing energy insufficiency, impairing proteasomal-mediated protein degradation and inducing apoptosis. Proteasome-evading proteins are degraded by autophagy in the lysosome, whose metabolism and function are regulated by master regulator transcription factor EB (TFEB). Limited studies have examined the impact of glucolipotoxicity on intra-lysosomal signaling proteins and their regulators. By utilizing a mouse model of diet-induced obesity, type-1 diabetes (Akita) and ex-vivo model of glucolipotoxicity (H9C2 cells and NRCM, neonatal rat cardiomyocyte), we examined whether glucolipotoxicity negatively targets TFEB and lysosomal proteins to dysregulate autophagy and cause cardiac injury. Despite differential effects of obesity and diabetes on LC3B-II, expression of proteins facilitating autophagosomal clearance such as TFEB, LAMP-2A, Hsc70 and Hsp90 were decreased in the obese and diabetic heart. In-vivo data was recapitulated in H9C2 and NRCM cells, which exhibited impaired autophagic flux and reduced TFEB content when exposed to a glucolipotoxic milieu. Notably, overloading myocytes with a saturated fatty acid (palmitate) but not an unsaturated fatty acid (oleate) depleted cellular TFEB and suppressed autophagy, suggesting a fatty acid specific regulation of TFEB and autophagy in the cardiomyocyte. The effect of glucolipotoxicity to reduce TFEB content was also confirmed in heart tissue from patients with Class-I obesity. Therefore, during glucolipotoxicity, suppression of lysosomal autophagy was associated with reduced lysosomal content, decreased cathepsin-B activity and diminished cellular TFEB content likely rendering myocytes susceptible to cardiac injury.

  5. UVA causes dual inactivation of cathepsin B and L underlying lysosomal dysfunction in human dermal fibroblasts.

    Science.gov (United States)

    Lamore, Sarah D; Wondrak, Georg T

    2013-06-05

    Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display 'UVA-mimetic' effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts.

  6. Endothelial Nlrp3 inflammasome activation associated with lysosomal destabilization during coronary arteritis.

    Science.gov (United States)

    Chen, Yang; Li, Xiang; Boini, Krishna M; Pitzer, Ashley L; Gulbins, Erich; Zhang, Yang; Li, Pin-Lan

    2015-02-01

    Inflammasomes play a critical role in the development of vascular diseases. However, the molecular mechanisms activating the inflammasome in endothelial cells and the relevance of this inflammasome activation is far from clear. Here, we investigated the mechanisms by which an Nlrp3 inflammasome is activated to result in endothelial dysfunction during coronary arteritis by Lactobacillus casei (L. casei) cell wall fragments (LCWE) in a mouse model for Kawasaki disease. Endothelial dysfunction associated with increased vascular cell adhesion protein 1 (VCAM-1) expression and endothelial-leukocyte adhesion was observed during coronary arteritis in mice treated with LCWE. Accompanied with these changes, the inflammasome activation was also shown in coronary arterial endothelium, which was characterized by a marked increase in caspase-1 activity and IL-1β production. In cultured endothelial cells, LCWE induced Nlrp3 inflammasome formation, caspase-1 activation and IL-1β production, which were blocked by Nlrp3 gene silencing or lysosome membrane stabilizing agents such as colchicine, dexamethasone, and ceramide. However, a potassium channel blocker glibenclamide or an oxygen free radical scavenger N-acetyl-l-cysteine had no effects on LCWE-induced inflammasome activation. LCWE also increased endothelial cell lysosomal membrane permeability and triggered lysosomal cathepsin B release into cytosol. Silencing cathepsin B blocked LCWE-induced Nlrp3 inflammasome formation and activation in endothelial cells. In vivo, treatment of mice with cathepsin B inhibitor also abolished LCWE-induced inflammasome activation in coronary arterial endothelium. It is concluded that LCWE enhanced lysosomal membrane permeabilization and consequent release of lysosomal cathepsin B, resulting in activation of the endothelial Nlrp3 inflammasome, which may contribute to the development of coronary arteritis.

  7. A Comparative Study on the Alterations of Endocytic Pathways in Multiple Lysosomal Storage Disorders.

    Science.gov (United States)

    Rappaport, Jeff; Manthe, Rachel L; Solomon, Melani; Garnacho, Carmen; Muro, Silvia

    2016-02-01

    Many cellular activities and pharmaceutical interventions involve endocytosis and delivery to lysosomes for processing. Hence, lysosomal processing defects can cause cell and tissue damage, as in lysosomal storage diseases (LSDs) characterized by lysosomal accumulation of undegraded materials. This storage causes endocytic and trafficking alterations, which exacerbate disease and hinder treatment. However, there have been no systematic studies comparing different endocytic routes in LSDs. Here, we used genetic and pharmacological models of four LSDs (type A Niemann-Pick, type C Niemann-Pick, Fabry, and Gaucher diseases) and evaluated the pinocytic and receptor-mediated activity of the clathrin-, caveolae-, and macropinocytic routes. Bulk pinocytosis was diminished in all diseases, suggesting a generic endocytic alteration linked to lysosomal storage. Fluid-phase (dextran) and ligand (transferrin) uptake via the clathrin route were lower for all LSDs. Fluid-phase and ligand (cholera toxin B) uptake via the caveolar route were both affected but less acutely in Fabry or Gaucher diseases. Epidermal growth factor-induced macropinocytosis was altered in Niemann-Pick cells but not other LSDs. Intracellular trafficking of ligands was also distorted in LSD versus wild-type cells. The extent of these endocytic alterations paralleled the level of cholesterol storage in disease cell lines. Confirming this, pharmacological induction of cholesterol storage in wild-type cells disrupted endocytosis, and model therapeutics restored uptake in proportion to their efficacy in attenuating storage. This suggests a proportional and reversible relationship between endocytosis and lipid (cholesterol) storage. By analogy, the accumulation of biological material in other diseases, or foreign material from drugs or their carriers, may cause similar deficits, warranting further investigation.

  8. Neurologic abnormalities in mouse models of the lysosomal storage disorders mucolipidosis II and mucolipidosis III γ.

    Directory of Open Access Journals (Sweden)

    Rachel A Idol

    Full Text Available UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase is an α2β2γ2 hexameric enzyme that catalyzes the synthesis of the mannose 6-phosphate targeting signal on lysosomal hydrolases. Mutations in the α/β subunit precursor gene cause the severe lysosomal storage disorder mucolipidosis II (ML II or the more moderate mucolipidosis III alpha/beta (ML III α/β, while mutations in the γ subunit gene cause the mildest disorder, mucolipidosis III gamma (ML III γ. Here we report neurologic consequences of mouse models of ML II and ML III γ. The ML II mice have a total loss of acid hydrolase phosphorylation, which results in depletion of acid hydrolases in mesenchymal-derived cells. The ML III γ mice retain partial phosphorylation. However, in both cases, total brain extracts have normal or near normal activity of many acid hydrolases reflecting mannose 6-phosphate-independent lysosomal targeting pathways. While behavioral deficits occur in both models, the onset of these changes occurs sooner and the severity is greater in the ML II mice. The ML II mice undergo progressive neurodegeneration with neuronal loss, astrocytosis, microgliosis and Purkinje cell depletion which was evident at 4 months whereas ML III γ mice have only mild to moderate astrocytosis and microgliosis at 12 months. Both models accumulate the ganglioside GM2, but only ML II mice accumulate fucosylated glycans. We conclude that in spite of active mannose 6-phosphate-independent targeting pathways in the brain, there are cell types that require at least partial phosphorylation function to avoid lysosomal dysfunction and the associated neurodegeneration and behavioral impairments.

  9. Campylobacter jejuni cell lysates differently target mitochondria and lysosomes on HeLa cells.

    Science.gov (United States)

    Canonico, B; Campana, R; Luchetti, F; Arcangeletti, M; Betti, M; Cesarini, E; Ciacci, C; Vittoria, E; Galli, L; Papa, S; Baffone, W

    2014-08-01

    Campylobacter jejuni is the most common cause of bacterial gastroenteritis in humans. The synthesis of cytolethal distending toxin appears essential in the infection process. In this work we evaluated the sequence of lethal events in HeLa cells exposed to cell lysates of two distinct strains, C. jejuni ATCC 33291 and C. jejuni ISS3. C. jejuni cell lysates (CCLys) were added to HeLa cell monolayers which were analysed to detect DNA content, death features, bcl-2 and p53 status, mitochondria/lysosomes network and finally, CD54 and CD59 alterations, compared to cell lysates of C. jejuni 11168H cdtA mutant. We found mitochondria and lysosomes differently targeted by these bacterial lysates. Death, consistent with apoptosis for C. jejuni ATCC 33291 lysate, occurred in a slow way (>48 h); concomitantly HeLa cells increase their endolysosomal compartment, as a consequence of toxin internalization besides a simultaneous and partial lysosomal destabilization. C. jejuni CCLys induces death in HeLa cells mainly via a caspase-dependent mechanism although a p53 lysosomal pathway (also caspase-independent) seems to appear in addition. In C. jejuni ISS3-treated cells, the p53-mediated oxidative degradation of mitochondrial components seems to be lost, inducing the deepest lysosomal alterations. Furthermore, CD59 considerably decreases, suggesting both a degradation or internalisation pathway. CCLys-treated HeLa cells increase CD54 expression on their surface, because of the action of lysate as its double feature of toxin and bacterial peptide. In conclusion, we revealed that C. jejuni CCLys-treated HeLa cells displayed different features, depending on the particular strain.

  10. Neuroprotective Strategies during Cardiac Surgery with Cardiopulmonary Bypass

    Science.gov (United States)

    Salameh, Aida; Dhein, Stefan; Dähnert, Ingo; Klein, Norbert

    2016-01-01

    Aortocoronary bypass or valve surgery usually require cardiac arrest using cardioplegic solutions. Although, in principle, in a number of cases beating heart surgery (so-called off-pump technique) is possible, aortic or valve surgery or correction of congenital heart diseases mostly require cardiopulmonary arrest. During this condition, the heart-lung machine also named cardiopulmonary bypass (CPB) has to take over the circulation. It is noteworthy that the invention of a machine bypassing the heart and lungs enabled complex cardiac operations, but possible negative effects of the CPB on other organs, especially the brain, cannot be neglected. Thus, neuroprotection during CPB is still a matter of great interest. In this review, we will describe the impact of CPB on the brain and focus on pharmacological and non-pharmacological strategies to protect the brain. PMID:27879647

  11. Vitamin deficiency after gastric bypass surgery: a review.

    Science.gov (United States)

    Matrana, Marc R; Davis, William E

    2009-10-01

    More than 60% of the adult US population now meets the criteria for being overweight or obese. Gastric bypass surgery has become a popular and effective way to combat this medical problem. Despite the success of these procedures, they are associated with many complications, including malnutrition, neurological compromise, and vitamin deficiency. Research has determined that even with multivitamin supplementation for life, a large percentage of bypass patients develop vitamin deficiencies. We present a case of beriberi after Roux-en-Y bypass that illustrates the importance of close follow up. A thorough review of vitamin deficiencies in this unique patient population is explored. Vitamin supplementation and treatment recommendations are compiled from the most up-to-date sources. Even patients on regular supplements should be closely monitored for vitamin deficiencies. Patient education regarding vitamin supplementation is vital; it should begin prior to surgery and continue throughout the postoperative period and beyond.

  12. A Comparative Performance Analysis of Low Power Bypassing Array Multipliers

    Directory of Open Access Journals (Sweden)

    Nirlakalla Ravi

    2013-07-01

    Full Text Available Low power design of VLSI circuits has been identified as vital technology in battery powered portable electronic devices and signal processing applications such as Digital Signal Processors (DSP. Multiplier has an important role in the DSPs. Without degrading the performance of the processor, low power parallel multipliers are needed to be design. Bypassing is the widely used technique in the DSPs when the input operand of the multiplier is zero. A Row based Bypassing Multiplier with compressor at the final addition of the ripple carry adder (RCA is designed to focus on low power and high speed. The proposed bypassing multiplier with compressor shows high performance and energy efficiency than Kuo multiplier with Carry Save Adder (CSA at the final RCA.

  13. Rankine cycle load limiting through use of a recuperator bypass

    Science.gov (United States)

    Ernst, Timothy C.

    2011-08-16

    A system for converting heat from an engine into work includes a boiler coupled to a heat source for transferring heat to a working fluid, a turbine that transforms the heat into work, a condenser that transforms the working fluid into liquid, a recuperator with one flow path that routes working fluid from the turbine to the condenser, and another flow path that routes liquid working fluid from the condenser to the boiler, the recuperator being configured to transfer heat to the liquid working fluid, and a bypass valve in parallel with the second flow path. The bypass valve is movable between a closed position, permitting flow through the second flow path and an opened position, under high engine load conditions, bypassing the second flow path.

  14. Proposal of bypass in heat recovery system with sucking air

    Science.gov (United States)

    Siažik, Ján; Malcho, Milan; Rezničák, Štefan

    2016-06-01

    Waste heat is utilized in a wide variety of technologies for a number of reasons. But the significant one such reason is use of the energy contained for example in waste water or waste heat that would otherwise left unused. Other considerable reason it is also reduces primary costs to operate the technology. The article deals with the arrangement section of the unit in heat recovery systems where the entry of waste gases into defluorinastion device. The technologies re-use heat often use the bypass. Bypass fulfill their duty in equipment failures, for example heat exchanger where it is not possible to stop the operationimmediately and the hot combustion gases can flow bypass without interrupting operation.

  15. Loss of β-glucocerebrosidase activity does not affect alpha-synuclein levels or lysosomal function in neuronal cells.

    Science.gov (United States)

    Dermentzaki, Georgia; Dimitriou, Evangelia; Xilouri, Maria; Michelakakis, Helen; Stefanis, Leonidas

    2013-01-01

    To date, a plethora of studies have provided evidence favoring an association between Gaucher disease (GD) and Parkinson's disease (PD). GD, the most common lysosomal storage disorder, results from the diminished activity of the lysosomal enzyme β-glucocerebrosidase (GCase), caused by mutations in the β-glucocerebrosidase gene (GBA). Alpha-synuclein (ASYN), a presynaptic protein, has been strongly implicated in PD pathogenesis. ASYN may in part be degraded by the lysosomes and may itself aberrantly impact lysosomal function. Therefore, a putative link between deficient GCase and ASYN, involving lysosomal dysfunction, has been proposed to be responsible for the risk for PD conferred by GBA mutations. In this current work, we aimed to investigate the effects of pharmacological inhibition of GCase on ASYN accumulation/aggregation, as well as on lysosomal function, in differentiated SH-SY5Y cells and in primary neuronal cultures. Following profound inhibition of the enzyme activity, we did not find significant alterations in ASYN levels, or any changes in the clearance or formation of its oligomeric species. We further observed no significant impairment of the lysosomal degradation machinery. These findings suggest that additional interaction pathways together with aberrant GCase and ASYN must govern this complex relation between GD and PD.

  16. Cytosolic chloride ion is a key factor in lysosomal acidification and function of autophagy in human gastric cancer cell.

    Science.gov (United States)

    Hosogi, Shigekuni; Kusuzaki, Katsuyuki; Inui, Toshio; Wang, Xiangdong; Marunaka, Yoshinori

    2014-06-01

    The purpose of the present study was to clarify roles of cytosolic chloride ion (Cl(-) ) in regulation of lysosomal acidification [intra-lysosomal pH (pHlys )] and autophagy function in human gastric cancer cell line (MKN28). The MKN28 cells cultured under a low Cl(-) condition elevated pHlys and reduced the intra-lysosomal Cl(-) concentration ([Cl(-) ]lys ) via reduction of cytosolic Cl(-) concentration ([Cl(-) ]c ), showing abnormal accumulation of LC3II and p62 participating in autophagy function (dysfunction of autophagy) accompanied by inhibition of cell proliferation via G0 /G1 arrest without induction of apoptosis. We also studied effects of direct modification of H(+) transport on lysosomal acidification and autophagy. Application of bafilomycin A1 (an inhibitor of V-type H(+) -ATPase) or ethyl isopropyl amiloride [EIPA; an inhibitor of Na(+) /H(+) exchanger (NHE)] elevated pHlys and decreased [Cl(-) ]lys associated with inhibition of cell proliferation via induction of G0 /G1 arrest similar to the culture under a low Cl(-) condition. However, unlike low Cl(-) condition, application of the compound, bafilomycin A1 or EIPA, induced apoptosis associated with increases in caspase 3 and 9 without large reduction in [Cl(-) ]c compared with low Cl(-) condition. These observations suggest that the lowered [Cl(-) ]c primarily causes dysfunction of autophagy without apoptosis via dysfunction of lysosome induced by disturbance of intra-lysosomal acidification. This is the first study showing that cytosolic Cl(-) is a key factor of lysosome acidification and autophagy.

  17. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro

    Directory of Open Access Journals (Sweden)

    Alberto Canfrán-Duque

    2016-03-01

    Full Text Available First- and second-generation antipsychotics (FGAs and SGAs, respectively, have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1′-dioctadecyl-3,3,3,3′-tetramethylindocarbocyanineperchlorate (DiI-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2 and LBPA (lysobisphosphatidic acid, which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1 and coatomer subunit β (β-COP were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes’ internal milieu induced by haloperidol affects lysosomal functionality.

  18. Glyco-engineering strategies for the development of therapeutic enzymes with improved efficacy for the treatment of lysosomal storage diseases.

    Science.gov (United States)

    Oh, Doo-Byoung

    2015-08-01

    Lysosomal storage diseases (LSDs) are a group of inherent diseases characterized by massive accumulation of undigested compounds in lysosomes, which is caused by genetic defects resulting in the deficiency of a lysosomal hydrolase. Currently, enzyme replacement therapy has been successfully used for treatment of 7 LSDs with 10 approved therapeutic enzymes whereas new approaches such as pharmacological chaperones and gene therapy still await evaluation in clinical trials. While therapeutic enzymes for Gaucher disease have N-glycans with terminal mannose residues for targeting to macrophages, the others require N-glycans containing mannose-6-phosphates that are recognized by mannose-6-phosphate receptors on the plasma membrane for cellular uptake and targeting to lysosomes. Due to the fact that efficient lysosomal delivery of therapeutic enzymes is essential for the clearance of accumulated compounds, the suitable glycan structure and its high content are key factors for efficient therapeutic efficacy. Therefore, glycan remodeling strategies to improve lysosomal targeting and tissue distribution have been highlighted. This review describes the glycan structures that are important for lysosomal targeting and provides information on recent glyco-engineering technologies for the development of therapeutic enzymes with improved efficacy.

  19. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro

    Science.gov (United States)

    Canfrán-Duque, Alberto; Barrio, Luis C.; Lerma, Milagros; de la Peña, Gema; Serna, Jorge; Pastor, Oscar; Lasunción, Miguel A.; Busto, Rebeca

    2016-01-01

    First- and second-generation antipsychotics (FGAs and SGAs, respectively), have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL)-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1′-dioctadecyl-3,3,3,3′-tetramethylindocarbocyanineperchlorate (DiI)-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2) and LBPA (lysobisphosphatidic acid), which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1) and coatomer subunit β (β-COP) were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes’ internal milieu induced by haloperidol affects lysosomal functionality. PMID:26999125

  20. Fibrin Adhesive: Clinical Application in Coronary Artery Bypass Graft Surgery

    Science.gov (United States)

    Fundaró, Pino; Velardi, Antonio R.; Santoli, Carmine

    1985-01-01

    Fibrin adhesive was used 72 times in a group of 67 patients undergoing elective coronary artery bypass graft surgery. The indications were prophylactic sealing of potential sources of bleeding, topical hemostasis (control of bleeding sites dangerous or difficult to suture), and fixation of the graft in the optimal position. The method of glue application under varying circumstances is described and the results are reported. This experience suggests that in some cases the glue expedites the operation and makes it safer. We conclude that the fibrin sealing represents a valid aid in coronary artery bypass graft surgery. PMID:15227018

  1. Obstetrical and neonatal outcomes in women following gastric bypass

    DEFF Research Database (Denmark)

    Berlac, Janne Foss; Skovlund, Charlotte Wessel; Lidegaard, Ojvind

    2014-01-01

    more admissions to neonatal intensive care unit compared with newborn of normal weight mothers; RR = 1.5 (1.1-2.0). CONCLUSIONS: Gastric bypass may reduce the risk of preeclampsia, emergency cesarean section, and perinatal asphyxia, compared with adipose women without surgery. Compared with normal...... weight controls women who had had a gastric bypass had a higher risk of hypertension, gestational diabetes, and acute abdominal pain during pregnancy and their children a lower birthweight and higher incidence of admittance to neonatal intensive care....

  2. [Prevalence of early and late dumping after gastric bypass].

    Science.gov (United States)

    Héraïef, R; Giusti, V

    2014-03-26

    Gastric bypass surgery is an effective treatment of obesity, bringing a significant weight loss and a major improvement of carbohydrate profile. However, in some patients, a deregulation in carbohydrate metabolism between insulin secretion and sensitivity is observed, whereupon early and late dumping happen. Their prevalence isn't well studied, although it seems that 10 to 20% of patients are affected. We've studied a cohort of 70 patients who undergone gastric bypass surgery at the CHUV. 18 (25.7%) patients have a positive anamnesis for early dumping and 10 (14.3%) for late dumping, being it superior as what is described in the literature.

  3. Dextrocardia with situs inversus totalis: coronary artery bypass grafting.

    Science.gov (United States)

    Hashmi, Salila; Anis, Mariam; Darr, Umer

    2012-01-01

    Dextrocardia with situs inversus is a rare congenital abnormality involving a left-handed mal rotation of the visceral organs. The incidence of coronary artery disease is the same as that in the general population. Performing coronary artery bypass surgery on patients with dextrocardia poses a more challenging task. It is recommended that the right internal mammary artery be the first choice of graft for the anterior descending artery for a "situs inversus" situation. We report 2 cases of patients with Dextrocardia who developed coronary artery disease and underwent coronary artery bypass grafting. Also mentioned is the slight difference in our technique.

  4. Tidlige erfaringer med duplexovervågning af femoropopliteale og -krurale vene-bypass

    DEFF Research Database (Denmark)

    Nielsen, Tina G; von Jessen, Frants; Schroeder, T V

    1993-01-01

    Identification and correction of graft stenoses in femoropopliteal and -crural vein bypasses can prevent reconstruction failure. Sixty six consecutive vein bypasses entered a postoperative surveillance protocol, which implied clinical assessment, measurement of ankle blood pressure and duplex-sca...

  5. Managing the Inflammatory Response after Cardiopulmonary Bypass : Review of the Studies in Animal Models

    NARCIS (Netherlands)

    Liguori, Gabriel Romero; Kanas, Alexandre Fligelman; Moreira, Luiz Felipe Pinho

    2014-01-01

    OBJECTIVE: To review studies performed in animal models that evaluated therapeutic interventions to inflammatory response and microcirculatory changes after cardiopulmonary bypass. METHODS: It was used the search strategy ("Cardiopulmonary Bypass" (MeSH)) and ("Microcirculation" (MeSH) or "Inflammat

  6. Off-pump coronary artery bypass grafting in patients with mirror-imaging dextrocardia.

    Science.gov (United States)

    Yuan, Xin; Sun, Hansong; Wang, Xianqiang

    2015-08-01

    Dextrocardia requires alterations in techniques during coronary artery bypass graft (CABG) surgery. We report two cases undergoing off-pump coronary artery bypass graft (OPCAB) surgery and discuss techniques for the operative management of these patients.

  7. Hereditary spherocytosis in a patient undergoing coronary artery bypass grafting with cardiopulmonary bypass--a case report.

    Science.gov (United States)

    Spegar, J; Riha, H; Kotulak, T; Vanek, T

    2015-01-01

    Hereditary spherocytosis is a genetically determined abnormality of red blood cells. It is the most common cause of inherited haemolysis in Europe and North America within the Caucasian population. We document a patient who underwent an aortocoronary bypass procedure on cardiopulmonary bypass. In view of the uncertain tolerance of the abnormal red cells in hereditary spherocytosis to cardiopulmonary bypass, we reviewed the patient's chart and analyzed recorded values of these parameters: free plasma haemoglobin, renal parameters, cystatin C, bilirubin, liver tests, urine samples. From the results, we can see that slight haemolysis-elevated bilirubin in the blood sample and elevated bilirubin and urobilinogen in the urine sample occurred on the first postoperative day. The levels of these parameters slowly decreased during the next postoperative days. There was no real clinical effect of this haemolysis on renal functions.

  8. Characterization of the egg vesicular components in the seaweed, Fucus serratus L. (Fucales, Phaeophyta), using enzyme histochemistry and vital staining: the search for a lysosome-like body.

    Science.gov (United States)

    Holland, R D; Pitt, D; Moore, M N; Brownlee, C

    1997-03-01

    Fucus serratus eggs were examined for evidence of the existence of a lysosome-like body using enzyme histochemical and vital staining techniques. Simultaneous coupling azo-dye techniques for lysosomal acid phosphatase proved inappropriate owing to endogenous phenolic binding artefacts. The large number of alginate polysaccharide and polyphenolic egg vesicles interfered with vital staining techniques for lysosomes. Lysosomal esterase activity was detected in the abundant egg lipid bodies. The role of the egg lipid body as an equivalent lysosome-like body of higher plants, the spherosome, is discussed in relation to egg fertilization and early zygote development.

  9. Effects of pH and Iminosugar Pharmacological Chaperones on Lysosomal Glycosidase Structure and Stability

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, Raquel L.; D’aquino, J. Alejandro; Ringe, Dagmar; Petsko, Gregory A.; (Harvard-Med); (Brandeis)

    2009-06-05

    Human lysosomal enzymes acid-{beta}-glucosidase (GCase) and acid-{alpha}-galactosidase ({alpha}-Gal A) hydrolyze the sphingolipids glucosyl- and globotriaosylceramide, respectively, and mutations in these enzymes lead to the lipid metabolism disorders Gaucher and Fabry disease, respectively. We have investigated the structure and stability of GCase and {alpha}-Gal A in a neutral-pH environment reflective of the endoplasmic reticulum and an acidic-pH environment reflective of the lysosome. These details are important for the development of pharmacological chaperone therapy for Gaucher and Fabry disease, in which small molecules bind mutant enzymes in the ER to enable the mutant enzyme to meet quality control requirements for lysosomal trafficking. We report crystal structures of apo GCase at pH 4.5, at pH 5.5, and in complex with the pharmacological chaperone isofagomine (IFG) at pH 7.5. We also present thermostability analysis of GCase at pH 7.4 and 5.2 using differential scanning calorimetry. We compare our results with analogous experiments using {alpha}-Gal A and the chaperone 1-deoxygalactonijirimycin (DGJ), including the first structure of {alpha}-Gal A with DGJ. Both GCase and {alpha}-Gal A are more stable at lysosomal pH with and without their respective iminosugars bound, and notably, the stability of the GCase-IFG complex is pH sensitive. We show that the conformations of the active site loops in GCase are sensitive to ligand binding but not pH, whereas analogous galactose- or DGJ-dependent conformational changes in {alpha}-Gal A are not seen. Thermodynamic parameters obtained from {alpha}-Gal A unfolding indicate two-state, van't Hoff unfolding in the absence of the iminosugar at neutral and lysosomal pH, and non-two-state unfolding in the presence of DGJ. Taken together, these results provide insight into how GCase and {alpha}-Gal A are thermodynamically stabilized by iminosugars and suggest strategies for the development of new pharmacological

  10. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  11. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    Directory of Open Access Journals (Sweden)

    Chen Ting

    2016-01-01

    Full Text Available The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  12. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    OpenAIRE

    Chen Ting; Yang Kang; Wu Li-Li

    2016-01-01

    The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  13. On-Pump Versus Off-Pump Coronary Artery Bypass Surgery in Elderly Patients

    DEFF Research Database (Denmark)

    Holme, Susanne Juel; Houlind, Kim; Kjeldsen, Bo Juul;

    2012-01-01

    Conventional coronary artery bypass grafting performed with the use of cardiopulmonary bypass is a well-validated treatment for patients with ischemic heart disease. Off-pump coronary artery bypass grafting (OPCAB) has been suggested to reduce the number of perioperative complications, especially...... in elderly patients....

  14. Natural headland sand bypassing; towards identifying and modelling the mechanisms and processes

    NARCIS (Netherlands)

    Bin Ab Razak, M.S.

    2015-01-01

    Natural headland sand bypassing: Towards identifying and modelling the mechanisms and processes contributes to the understanding of the mechanisms and processes of sand bypassing in artificial and non-artificial coastal environments through a numerical modelling study. Sand bypassing processes in ge

  15. On-pump versus off-pump coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Houlind, Kim Christian

    2013-01-01

    Off pump coronary artery bypass surgery has been purported to be safer than conventional coronary artery bypass surgery performed using cardiopulmonary bypass. This theory was supported by a number of early series, but failed to be confirmed by a number of small, randomized controlled trials . Co...

  16. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Science.gov (United States)

    2010-04-01

    ... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery to... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass vascular catheter,...

  17. Patient Bypass Behavior and Critical Access Hospitals: Implications for Patient Retention

    Science.gov (United States)

    Liu, Jiexin (Jason); Bellamy, Gail R.; McCormick, Melissa

    2007-01-01

    Purpose: To assess the extent of bypass for inpatient care among patients living in Critical Access Hospital (CAH) service areas, and to determine factors associated with bypass, the reasons for bypass, and what CAHs can do to retain patients locally. Methods: Six hundred and forty-seven subjects, aged 18 years and older, who had been admitted to…

  18. Emergency EC-IC bypass for symptomatic atherosclerotic ischemic stroke.

    Science.gov (United States)

    Horiuchi, Tetsuyoshi; Nitta, Junpei; Ishizaka, Shigetoshi; Kanaya, Kohei; Yanagawa, Takao; Hongo, Kazuhiro

    2013-10-01

    Previous studies have shown that extracranial-intracranial (EC-IC) bypass surgery has no preventive effect on subsequent ipsilateral ischemic stroke in patients with symptomatic atherosclerotic internal carotid occlusion and hemodynamic cerebral ischemia. A few studies have assessed whether an urgent EC-IC bypass surgery is an effective treatment for main trunk stenosis or occlusion in acute stage. The authors retrospectively reviewed 58 consecutive patients who underwent urgent EC-IC bypass for symptomatic internal carotid artery or the middle cerebral artery stenosis or occlusion between January 2003 and December 2011. Clinical characteristics and neuroimagings were evaluated and analyzed. Based on preoperative angiogram, responsible lesions were the internal carotid artery in 19 (32.8%) patients and the middle cerebral artery in 39 (67.2%). No hemorrhagic complication occurred. Sixty-nine percent of patients showed improvement of neurological function after surgery, and 74.1% of patients had favorable outcome. Unfavorable outcome was associated with insufficient collateral flow and new infarction after bypass surgery.

  19. Emergency bypass post percutaneous atrial ablation: a case report.

    LENUS (Irish Health Repository)

    Hargrove, M

    2010-11-01

    A 34-year-old male undergoing percutaneous atrial ablation procedure for paroxysmal fibrillation required emergency sternotomy for cardiac tamponade. The patient had been anticoagulated and had received plavix and aspirin prior to and during the ablation procedure. Seven units of red cell concentrate had been transfused in the cardiac catherisation laboratory. On arrival in theatre, the patient was hypotensive, but was awake on induction of anaesthesia. No recordable blood pressure with non-invasive monitoring was observed. A sternotomy was immediately performed and, on evacuation of the pericardium, a bleeding site was not visible. The patient was commenced on cardiopulmonary bypass. Bleeding site was identified and the defect closed. The patient was weaned from cardiopulmonary bypass with minimal inotropic support and made an uneventful recovery. Bypass time was 38 minutes. A literature review showed a 1% incidence of post-ablation bleeding(1). The incidence of reverting to bypass for such an event has not been reported previously. During these procedures, it might be wise to have the cardiothoracic team notified while atrial ablation procedures are being performed in the cardiac catheterization laboratory.

  20. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass oxygenator. 870.4350 Section 870.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... gases between blood and a gaseous environment to satisfy the gas exchange needs of a patient during...

  1. Bypassing of a barrier by dissociated and superlattice dislocations

    DEFF Research Database (Denmark)

    Bhushan, Karihaloo

    1975-01-01

    Very simple procedures are used to calculate the upper and lower bounds for the applied stress required for the leading extended (superlattice) dislocation in a group of n coplanar screw dislocations of like sign with Burgers vector b to bypass a noncoplanar perfect screw dislocation with Burgers...... vector mb (m...

  2. Polarization for the by-pass SLAC/PEP collider

    Energy Technology Data Exchange (ETDEWEB)

    Chao, A.W.

    1980-06-01

    It was suggested that one can collide the store e/sup +/ beam in PEP with the e/sup /minus// beam from SLAC to reach a center-of-mass energy higher than that achieved by the PEP colliding beams. Although the future of this PEP/SLAC collider is not yet certain, it is useful to first explore its physics possibilities. One possible version of the SLAC/PEP collider utilizes a by-pass at the interaction point; the stored beam is displaced vertically by a set of vertical bending magnets every time the linac beam arrives. One feature of this by-pass scheme that makes it attractive is that the amount of the vertical displacement of the by-pass can be chosen so that the spin polarization of the stored beam is made longitudinal at the point of interaction. In this note, we have studied the various depolarization effects of the stored e/sup +/ beam due to the perturbation of the by-pass magnets. 1 fig.

  3. Prediction of bypass transition with differential Reynolds stress models

    NARCIS (Netherlands)

    Westin, K.J.A.; Henkes, R.A.W.M.

    1998-01-01

    Boundary layer transition induced by high levels of free stream turbulence (FSl), so called bypass transition, can not be predicted with conventional stability calculations (e.g. the en-method). The use of turbulence models for transition prediction has shown some success for this type of flows, and

  4. Blood concentrations of cefuroxime in cardiopulmonary bypass surgery

    NARCIS (Netherlands)

    Bertholee, Daphne; ter Horst, Peter G. J.; Hijmering, Michel L.; Spanjersberg, Alexander J.; Hospes, Wobbe; Wilffert, Bob

    2013-01-01

    Objectives Patients with coronary artery bypass graft (CABG) surgery are at risk for severe postoperative infections. Prophylactic cefuroxime may help to reduce this risk, however sufficient concentrations, i.e. above the breakpoint (32 mg/L), are mandatory. The aim of this study is to evaluate the

  5. The influence of biomaterials on inflammatory responses to cardiopulmonary bypass.

    Science.gov (United States)

    Courtney, J M; Matata, B M; Yin, H Q; Esposito, A; Mahiout, A; Taggart, D P; Lowe, G D

    1996-05-01

    The nature of cardiopulmonary bypass and the complexity of the inflammatory response make the detection and interpretation of a biomaterial influence difficult. However, if mediation of the inflammatory response is considered to be an appropriate clinical goal, alteration to the biomaterial influence merits further investigation.

  6. Gastrointestinal motility during cardiopulmonary bypass : A sonomicrometric study

    NARCIS (Netherlands)

    Gu, YJ; de Kroon, TL; Elstrodt, JM; Rakhorst, G

    2006-01-01

    Cardiopulmonary bypass (CPB) is known to impair the integrity of the gastrointestinal tract. However, little is known about the movement behavior of the gastrointestinal tract during CPB. This study was aimed to assess the gastrointestinal motility with sonomicrometry, a distance measurement using u

  7. Fabric heart retractor for coronary artery bypass operations.

    Science.gov (United States)

    Kazama, S; Ishihara, A

    1993-06-01

    A new device for heart retraction during coronary artery bypass operations has been developed. It provides safe and steady support and an unobstructed view of the lateral, posterior, and inferior surfaces of the heart; in addition, it is easy to handle.

  8. Pathophysiology and treatment of edema following femoropopliteal bypass surgery

    NARCIS (Netherlands)

    te Slaa, A.; Dolmans, D. E. J. G. J.; Ho, G. H.; Moll, F. L.; van der Laan, L.

    2012-01-01

    Substantial lower-limb edema affects the majority of patients who undergo peripheral bypass surgery. Edema has impairing effects on the microvascular and the macrovascular circulation, causes discomfort and might delay the rehabilitation process of the patient. However, the pathophysiology of this e

  9. Clinical benefit of steroid use in patients undergoing cardiopulmonary bypass

    DEFF Research Database (Denmark)

    Whitlock, Richard P; Chan, Simon; Devereaux, P J;

    2008-01-01

    We sought to establish the efficacy and safety of prophylactic steroids in adult patients undergoing cardiopulmonary bypass (CPB). We performed a meta-analysis of randomized trials reporting the effects of prophylactic steroids on clinical outcomes after CPB. Outcomes examined were mortality...

  10. Localization of acid hydrolases in protoplasts. Examination of the proposed lysosomal function of the mature vacuole

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, H.C.; Wagner, G.J.; Siegelman, H.W.

    1977-06-01

    The development of techniques to isolate and purify relatively large quantities of intact vacuoles from mature tissues permits direct biochemical analysis of this ubiquitous mature plant cell organelle. Vacuoles and a fraction enriched in soluble cytoplasmic constituents were quantitatively prepared from Hippeastrum flower petal protoplasts. Vacuolar lysate and soluble cytoplasmic fractions were examined for acid hydrolase activities commonly associated with animal lysosomes, and pH optima were determined. Esterase, protease, carboxypeptidase, ..beta..-galactosidase, ..cap alpha..-glycosidase and ..beta..-glycosidase, not found in the vacuole lysate fraction, were components of the soluble cytoplasmic fraction. Acid phosphatase, RNase and DNase were present in both fractions. Vacuolar enzyme activities were also examined as a function of flower development from bud through senescent stages. The data obtained are not consistent with the concept that the mature plant cell vacuole functions as a generalized lysosome.

  11. Campylobacter jejuni survives within epithelial cells by avoiding delivery to lysosomes.

    Directory of Open Access Journals (Sweden)

    Robert O Watson

    2008-01-01

    Full Text Available Campylobacter jejuni is one of the major causes of infectious diarrhea world-wide, although relatively little is know about its mechanisms of pathogenicity. This bacterium can gain entry into intestinal epithelial cells, which is thought to be important for its ability to persistently infect and cause disease. We found that C. jejuni is able to survive within intestinal epithelial cells. However, recovery of intracellular bacteria required pre-culturing under oxygen-limiting conditions, suggesting that C. jejuni undergoes significant physiological changes within the intracellular environment. We also found that in epithelial cells the C. jejuni-containing vacuole deviates from the canonical endocytic pathway immediately after a unique caveolae-dependent entry pathway, thus avoiding delivery into lysosomes. In contrast, in macrophages, C. jejuni is delivered to lysosomes and consequently is rapidly killed. Taken together, these studies indicate that C. jejuni has evolved specific adaptations to survive within host cells.

  12. uPARAP/endo180 directs lysosomal delivery and degradation of collagen IV

    DEFF Research Database (Denmark)

    Kjøller, Lars; Engelholm, Lars H; Høyer-Hansen, Maria

    2004-01-01

    transmembrane glycoprotein urokinase plasminogen activator receptor-associated protein (uPARAP/endo180) directs collagen IV for lysosomal delivery and degradation. In wild-type fibroblasts, fluorescently labeled collagen IV was first internalized into vesicular structures with diffuse fluorescence eventually......Collagen turnover is crucial for tissue homeostasis and remodeling and pathological processes such as cancer invasion, but the underlying molecular mechanisms are poorly understood. A major pathway appears to be internalization and degradation by fibroblasts. We now show that the endocytic...... appearing uniformly within the wild-type cells after longer incubation times. In these cells, some collagen-containing vesicles were identified as lysosomes by staining for LAMP-1. In contrast, collagen IV remained extracellular and associated with fiber-like structures on uPARAP/endo180-deficient...

  13. Computer-assisted LAD bypass grafting at the open heart

    Science.gov (United States)

    Hartung, Christine; Gnahm, Claudia; Friedl, Reinhard; Hoffmann, Martin; Dietmayer, Klaus

    2009-02-01

    Open heart bypass surgery is the standard treatment in advanced coronary heart diseases. For an effective revascularization procedure, optimal placement of the bypass is very important. To accelerate the intraoperative localization of the anastomosis site and to increase the precision of the procedure, a concept for computer assistance in open heart bypass surgery has been developed comprising the following steps: 1. Preprocedural planning: A patient-specific coronary map with information on vessel paths and wall plaque formations is extracted from a multi-slice computed tomography (MSCT). On this basis, the heart surgeon and the cardiac radiologist define the optimal anastomosis site prior to surgery. 2. Intraoperative navigation: During surgery, data are recorded at the beating heart using a stereo camera system. After registering the pre- and intraoperative data sets, preprocedural information can be transferred to the surgical site by overlaying the coronary map and the planned anastomosis site on the live video stream. With this visual guidance system, the surgeon can navigate to the planned anastomosis site. In this work, the proposed surgical assistance system has been validated for the left anterior descending coronary artery (LAD). The accuracy of the registration mechanism has been evaluated in retrospective on patient data sets and the effects of breathing motion were quantified. The promising results of the retrospective evaluation led to the in-vivo application of the computer assistance system during several bypass grafting procedures. Intraoperative navigation has been performed successfully and postoperative evaluation confirms that the bypass grafts were accurately positioned to the preoperatively planned anastomosis sites.

  14. Reoperations for occluded arterial bypasses in the lower limbs

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background We reviewed the outcomes of reoperations for 29 patients (30 limbs) who had undergone occluded arterial bypass in the lower limbs from May 1996 to September 2005. Methods The 30 lower limbs of the 29 patients with arteriosclerotic obstruction received 44 reoperations, including thrombectomy alone (group T, 27) and inflow or outflow reconstruction plus thrombectomy (group C, 17). Among the 17 operations in group C, 17.6% (3/17) were inflow reconstructions involving the axillary-femoral (1), aorta-iliac (1) and aorta-femoral (1) arteries, and 76.4% (13/17) outflow reconstructions involving the femoral-popliteal bypass-tibial (8), femoral-tibial (1), femoral-popliteal bypass-popliteal arteries below the knee (2), and the femoral-popliteal bypass-tibial-peroneal trunk (2). One patient (1 limb) underwent both inflow and outflow reconstructions with an iliac arterial stent and a graft-popliteal anastomosis patch. Polytetrafluoroethylene (PTFE) grafts were used in the inflow or outflow reconstructions abve the knee. Autovenous grafts or autovenously combined PTFE grafts were used in the outflow reconstructions below the knee. Results The percentages of Fontaine stage III and IV before primary operation and reoperation were 60% (18/30) and 86.7% (26/30), respectively (P0.05). Among 42 reoperations, 19 failed within 1 month in groups T (16) and C (3) (P0.05). The rate of limb salvage was 64.29% (18/28). Conclusions The percentages of Fontaine stage III and IV before reoperation may be much higher than those before primary operation. Thrombectomy plus inflow/outflow reconstruction creates patency better than thrombectomy alone for re-occluded bypass.

  15. Preventive effect of phytic acid on lysosomal hydrolases in normal and isoproterenol-induced myocardial infarction in Wistar rats.

    Science.gov (United States)

    Brindha, E; Rajasekapandiyan, M

    2015-02-01

    This study was aimed to evaluate the preventive role of phytic acid on lysosomal enzymes in isoproterenol (ISO)-induced myocardial infarction (MI) in male Wistar rats. Rats subcutaneously injected with ISO (85 mg/kg) at an interval of 24 h for two days showed a significant increase in the activities of lysosomal enzymes (glucuronidase, N-acetyl glucosaminidase, galactosidase, cathepsin-B and cathepsin-D) were increased significantly in serum and the heart of ISO-induced rats, but the activities of glucuronidase and cathepsin-D were decreased significantly in the lysosomal fraction of the heart. Pretreatment with phytic acid (25 and 50 mg/kg) daily for a period of 56 d positively altered activities of lysosomal hydrolases in ISO-induced rats. Thus, phytic acid possesses a cardioprotective effect in ISO-induced MI in rats.

  16. Constitutively internalized dopamine transporter is targeted to late endosomes and lysosomal degradation in heterologous cell lines and dopaminergic neurons

    DEFF Research Database (Denmark)

    Eriksen, Jacob; Madsen, Kenneth; Vægter, Christian Bjerggaard;

    (leupeptin, chloroquine, or ammonium chloride) increased the amount of transporter accumulated intracellularly over time, suggesting that constitutively endocytosed transporter was targeted to lysosomal degradation. This was further supported by expression of Tac-DAT in the immortalized dopaminergic cell...

  17. Endo-lysosomal TRP mucolipin-1 channels trigger global ER Ca2+ release and Ca2+ influx

    Science.gov (United States)

    Kilpatrick, Bethan S.; Yates, Elizabeth; Grimm, Christian; Schapira, Anthony H.

    2016-01-01

    ABSTRACT Transient receptor potential (TRP) mucolipins (TRPMLs), encoded by the MCOLN genes, are patho-physiologically relevant endo-lysosomal ion channels crucial for membrane trafficking. Several lines of evidence suggest that TRPMLs mediate localised Ca2+ release but their role in Ca2+ signalling is not clear. Here, we show that activation of endogenous and recombinant TRPMLs with synthetic agonists evoked global Ca2+ signals in human cells. These signals were blocked by a dominant-negative TRPML1 construct and a TRPML antagonist. We further show that, despite a predominant lysosomal localisation, TRPML1 supports both Ca2+ release and Ca2+ entry. Ca2+ release required lysosomal and ER Ca2+ stores suggesting that TRPMLs, like other endo-lysosomal Ca2+ channels, are capable of ‘chatter’ with ER Ca2+ channels. Our data identify new modalities for TRPML1 action. PMID:27577094

  18. A Genome-wide RNAi Screen for Microtubule Bundle Formation and Lysosome Motility Regulation in Drosophila S2 Cells

    Directory of Open Access Journals (Sweden)

    Amber L. Jolly

    2016-01-01

    Full Text Available Long-distance intracellular transport of organelles, mRNA, and proteins (“cargo” occurs along the microtubule cytoskeleton by the action of kinesin and dynein motor proteins, but the vast network of factors involved in regulating intracellular cargo transport are still unknown. We capitalize on the Drosophila melanogaster S2 model cell system to monitor lysosome transport along microtubule bundles, which require enzymatically active kinesin-1 motor protein for their formation. We use an automated tracking program and a naive Bayesian classifier for the multivariate motility data to analyze 15,683 gene phenotypes and find 98 proteins involved in regulating lysosome motility along microtubules and 48 involved in the formation of microtubule filled processes in S2 cells. We identify innate immunity genes, ion channels, and signaling proteins having a role in lysosome motility regulation and find an unexpected relationship between the dynein motor, Rab7a, and lysosome motility regulation.

  19. Protective Role of Endogenous Gangliosides for Lysosomal Pathology in a Cellular Model of Synucleinopathies

    OpenAIRE

    Wei, Jianshe; Fujita, Masayo; Nakai, Masaaki; Waragai, Masaaki; Sekigawa, Akio; Sugama, Shuei; Takenouchi, Takato; Masliah, Eliezer; Hashimoto,Makoto

    2009-01-01

    Gangliosides may be involved in the pathogenesis of Parkinson’s disease and related disorders, although the precise mechanisms governing this involvement remain unknown. In this study, we determined whether changes in endogenous ganglioside levels affect lysosomal pathology in a cellular model of synucleinopathy. For this purpose, dementia with Lewy body-linked P123H β-synuclein (β-syn) neuroblastoma cells transfected with α-synuclein were used as a model system because these cells were chara...

  20. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability

    OpenAIRE

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan; Li, Longjiang

    2015-01-01

    Para-toluenesulfonamide (PTS) has been implicated with anticancer effects against a variety of tumors. In the present study, we investigated the inhibitory effects of PTS on tongue squamous cell carcinoma (Tca-8113) and explored the lysosomal and mitochondrial changes after PTS treatment in vitro. High-performance liquid chromatography showed that PTS selectively accumulated in Tca-8113 cells with a relatively low concentration in normal fibroblasts. Next, the effects of PTS on cell viability...

  1. Revealing the fate of cell surface human P-glycoprotein (ABCB1): The Lysosomal Degradation Pathway

    Science.gov (United States)

    Katayama, Kazuhiro; Kapoor, Khyati; Ohnuma, Shinobu; Patel, Atish; Swaim, William; Ambudkar, Indu S.; Ambudkar, Suresh V.

    2015-01-01

    P-glycoprotein (P-gp) transports a variety of chemically dissimilar amphipathic compounds including anticancer drugs. Although mechanisms of P-gp drug transport are widely studied, the pathways involving its internalization are poorly understood. The present study is aimed at elucidating the pathways involved in degradation of cell surface P-gp. The fate of P-gp at the cell surface was determined by biotinylating cell surface proteins followed by flow cytometry and Western blotting. Our data shows that the half-life of endogenously expressed P-gp is 26.7 ± 1.1 h in human colorectal cancer HCT-15 cells. Treatment of cells with Bafilomycin A1 (BafA1) a vacuolar H+ ATPase inhibitor increased the half-life of P-gp at the cell surface to 36.1± 0.5 h. Interestingly, treatment with the proteasomal inhibitors MG132, MG115 or lactacystin alone did not alter the half-life of the protein. When cells were treated with both lysosomal and proteasomal inhibitors (BafA1 and MG132), the half-life was further prolonged to 39-50 h. Functional assays done with rhodamine 123 or calcein-AM, fluorescent substrates of P-gp, indicated that the transport function of P-gp was not affected by either biotinylation or treatment with BafA1 or proteasomal inhibitors. Immunofluorescence studies done with the antibody against lysosomal marker LAMP1 and the P-gp-specific antibody UIC2 in permeabilized cells indicated that intracellular P-gp is primarily localized in the lysosomal compartment. Our results suggest that the lysosomal degradation system could be targeted to increase the sensitivity of P-gp expressing cancer cells towards chemotherapeutic drugs. PMID:26057472

  2. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Peres, G.B. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Juliano, M.A. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Biofísica, São Paulo, SP, Brasil, Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Aguiar, J.A.K.; Michelacci, Y.M. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-05-09

    It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old), while 26 age-matched controls received only vehicle. The livers were removed on either the 10{sup th} or the 30{sup th} day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA) of cathepsins B and L was also decreased on the 10{sup th}, but not on the 30{sup th} day. Sulfatase decreased 30% on the 30{sup th} day, while glycosidases did not vary (or presented a transitory and slight decrease). There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  3. Lysosomal trafficking of {beta}-catenin induced by the tea polyphenol epigallocatechin-3-gallate

    Energy Technology Data Exchange (ETDEWEB)

    Dashwood, Wan-Mohaiza [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Carter, Orianna [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Al-Fageeh, Mohamed [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Li, Qingjie [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Dashwood, Roderick H. [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States)]. E-mail: Rod.Dashwood@oregonstate.edu

    2005-12-11

    {beta}-Catenin is a cadherin-binding protein involved in cell-cell adhesion, which also functions as a transcriptional activator when complexed in the nucleus with members of the T-cell factor (TCF)/lymphoid enhancer factor (LEF) family of proteins. There is considerable interest in mechanisms that down-regulate {beta}-catenin, since this provides an avenue for the prevention of colorectal and other cancers in which {beta}-catenin is frequently over-expressed. We show here that physiologically relevant concentrations of the tea polyphenol epigallocatechin-3-gallate (EGCG) inhibited {beta}-catenin/TCF-dependent reporter activity in human embryonic kidney 293 cells transfected with wild type or mutant {beta}-catenins, and there was a corresponding decrease in {beta}-catenin protein levels in the nuclear, cytosolic and membrane-associated fractions. However, {beta}-catenin accumulated as punctate aggregates in response to EGCG treatment, including in human colon cancer cells over-expressing {beta}-catenin endogenously. Confocal microscopy studies revealed that the aggregated {beta}-catenin in HEK293 cells was extra-nuclear and co-localized with lysosomes, suggesting that EGCG activated a pathway involving lysosomal trafficking of {beta}-catenin. Lysosomal inhibitors leupeptin and transepoxysuccinyl-L-leucylamido(4-guanido)butane produced an increase in {beta}-catenin protein in total cell lysates, without a concomitant increase in {beta}-catenin transcriptional activity. These data provide the first evidence that EGCG facilitates the trafficking of {beta}-catenin into lysosomes, presumably as a mechanism for sequestering {beta}-catenin and circumventing further nuclear transport and activation of {beta}-catenin/TCF/LEF signaling.

  4. Revealing the fate of cell surface human P-glycoprotein (ABCB1): The lysosomal degradation pathway.

    Science.gov (United States)

    Katayama, Kazuhiro; Kapoor, Khyati; Ohnuma, Shinobu; Patel, Atish; Swaim, William; Ambudkar, Indu S; Ambudkar, Suresh V

    2015-10-01

    P-glycoprotein (P-gp) transports a variety of chemically dissimilar amphipathic compounds including anticancer drugs. Although mechanisms of P-gp drug transport are widely studied, the pathways involving its internalization are poorly understood. The present study is aimed at elucidating the pathways involved in degradation of cell surface P-gp. The fate of P-gp at the cell surface was determined by biotinylating cell surface proteins followed by flow cytometry and Western blotting. Our data shows that the half-life of endogenously expressed P-gp is 26.7±1.1 h in human colorectal cancer HCT-15 cells. Treatment of cells with Bafilomycin A1 (BafA1) a vacuolar H+ ATPase inhibitor increased the half-life of P-gp at the cell surface to 36.1±0.5 h. Interestingly, treatment with the proteasomal inhibitors MG132, MG115 or lactacystin alone did not alter the half-life of the protein. When cells were treated with both lysosomal and proteasomal inhibitors (BafA1 and MG132), the half-life was further prolonged to 39-50 h. Functional assays done with rhodamine 123 or calcein-AM, fluorescent substrates of P-gp, indicated that the transport function of P-gp was not affected by either biotinylation or treatment with BafA1 or proteasomal inhibitors. Immunofluorescence studies done with the antibody against lysosomal marker LAMP1 and the P-gp-specific antibody UIC2 in permeabilized cells indicated that intracellular P-gp is primarily localized in the lysosomal compartment. Our results suggest that the lysosomal degradation system could be targeted to increase the sensitivity of P-gp- expressing cancer cells towards chemotherapeutic drugs.

  5. Characterization and cloning of lgp110, a lysosomal membrane glycoprotein from mouse and rat cells.

    Science.gov (United States)

    Granger, B L; Green, S A; Gabel, C A; Howe, C L; Mellman, I; Helenius, A

    1990-07-15

    lgp110 is a heavily glycosylated intrinsic protein of lysosomal membranes. Initially defined by monoclonal antibodies against mouse liver lysosomes, it consists of a 45-kilodalton core polypeptide with O-linked and 17 asparagine-linked oligosaccharide side chains in mouse cells. Sialic acid residues make the mature protein extremely acidic, with an isoelectric point of between 2 and 4 in both normal tissues and most cultured cell lines. Partial sequencing of mouse lgp110 allowed oligonucleotide probes to be constructed for the screening of several mouse cDNA libraries. A partial cDNA clone for mouse lgp110 was found and used for additional library screening, generating a cDNA clone covering all of the coding sequence of mature rat lgp110 as well as genomic clones covering most of the mouse gene. These new clones bring to seven the number of lysosomal membrane proteins whose amino acid sequences can be deduced, and two distinct but highly similar groups (designated lgp-A and lgp-B) can now be defined. Sequence comparisons suggest that differences within each group reflect species variations of the same protein and that lgp-A and lgp-B probably diverged from a common ancestor prior to the evolup4f1ary divergence of birds and mammals. Individual cells and individual lysosomes possess both lgp-A and lgp-B, suggesting that these two proteins have different functions. Mouse lgp110 is encoded by at least seven exons; intron positions suggest that the two homologous ectodomains of each lgp arose through gene duplication.

  6. MDMA induces cardiac contractile dysfunction through autophagy upregulation and lysosome destabilization in rats.

    Science.gov (United States)

    Shintani-ishida, Kaori; Saka, Kanju; Yamaguchi, Koji; Hayashida, Makiko; Nagai, Hisashi; Takemura, Genzou; Yoshida, Ken-ichi

    2014-05-01

    The underlying mechanisms of cardiotoxicity of 3,4-methylenedioxymethylamphetamine (MDMA, "ecstasy") abuse are unclear. Autophagy exerts either adaptive or maladaptive effects on cardiac function in various pathological settings, but nothing is known on the role of autophagy in the MDMA cardiotoxicity. Here, we investigated the mechanism through which autophagy may be involved in MDMA-induced cardiac contractile dysfunction. Rats were injected intraperitoneally with MDMA (20mg/kg) or saline. Left ventricular (LV) echocardiography and LV pressure measurement demonstrated reduction of LV systolic contractility 24h after MDMA administration. Western blot analysis showed a time-dependent increase in the levels of microtubule-associated protein light chain 3-II (LC3-II) and cathepsin-D after MDMA administration. Electron microscopy showed the presence of autophagic vacuoles in cardiomyocytes. MDMA upregulated phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) at Thr172, mammalian target of rapamycin (mTOR) at Thr2446, Raptor at Ser792, and Unc51-like kinase (ULK1) at Ser555, suggesting activation of autophagy through the AMPK-mTOR pathway. The effects of autophagic inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) on LC3-II levels indicated that MDMA enhanced autophagosome formation, but attenuated autophagosome clearance. MDMA also induced release of cathepsins into cytosol, and western blotting and electron microscopy showed cardiac troponin I (cTnI) degradation and myofibril damage, respectively. 3-MA, CQ, and a lysosomal inhibitor, E64c, inhibited cTnI proteolysis and improved contractile dysfunction after MDMA administration. In conclusion, MDMA causes lysosome destabilization following activation of the autophagy-lysosomal pathway, through which released lysosomal proteases damage myofibrils and induce LV systolic dysfunction in rat heart.

  7. Lysosomal membrane stability in laboratory- and field-exposed terrestrial isopods Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Nolde, Natasa; Drobne, Damjana; Valant, Janez; Padovan, Ingrid; Horvat, Milena

    2006-08-01

    Two established methods for assessment of the cytotoxicity of contaminants, the lysosomal latency (LL) assay and the neutral red retention (NRR) assay, were successfully applied to in toto digestive gland tubes (hepatopancreas) of the terrestrial isopod Porcellio scaber (Isopoda, Crustacea). In vitro exposure of isolated gland tubes to copper was used as a positive control to determine the performance of the two methods. Lysosomal latency and the NRR assay were then used on in vivo (via food) laboratory-exposed animals and on field populations. Arbitrarily selected criteria for determination of the fitness of P. scaber were set on the basis of lysosomal membrane stability (LMS) as assessed with in toto digestive gland tubes. Decreased LMS was detected in animals from all polluted sites, but cytotoxicity data were not in agreement with concentrations of pollutants. Lysosomal membrane stability in the digestive gland tubes of animals from an environment in Idrija, Slovenia that was highly polluted with mercury (260 microg/g dry wt food and 1,600 microg/g dry wt soil) was less affected than LMS in laboratory animals fed with 5 and 50 microg Hg/g dry weight for 3 d. This probably indicates tolerance of P. scaber to mercury in the mercury-polluted environment and/or lower bioavailability of environmental mercury. In animals from the vicinity of a thermal power plant with environmental mercury concentrations three to four orders of magnitude lower than those in Idrija, LMS was severely affected. In general, the LL assay was more sensitive than the NRR assay. The LMS assay conducted on digestive gland tubes of terrestrial isopods is highly recommended for integrated biomarker studies.

  8. Factors influencing the measurement of lysosomal enzymes activity in human cerebrospinal fluid.

    Directory of Open Access Journals (Sweden)

    Emanuele Persichetti

    Full Text Available Measurements of the activities of lysosomal enzymes in cerebrospinal fluid have recently been proposed as putative biomarkers for Parkinson's disease and other synucleinopathies. To define the operating procedures useful for ensuring the reliability of these measurements, we analyzed several pre-analytical factors that may influence the activity of β-glucocerebrosidase, α-mannosidase, β-mannosidase, β-galactosidase, α-fucosidase, β-hexosaminidase, cathepsin D and cathepsin E in cerebrospinal fluid. Lysosomal enzyme activities were measured by well-established fluorimetric assays in a consecutive series of patients (n = 28 with different neurological conditions, including Parkinson's disease. The precision, pre-storage and storage conditions, and freeze/thaw cycles were evaluated. All of the assays showed within- and between-run variabilities below 10%. At -20°C, only cathepsin D was stable up to 40 weeks. At -80°C, the cathepsin D, cathepsin E, and β-mannosidase activities did not change significantly up to 40 weeks, while β-glucocerebrosidase activity was stable up to 32 weeks. The β-galactosidase and α-fucosidase activities significantly increased (+54.9±38.08% after 4 weeks and +88.94±36.19% after 16 weeks, respectively. Up to four freeze/thaw cycles did not significantly affect the activities of cathepsins D and E. The β-glucocerebrosidase activity showed a slight decrease (-14.6% after two freeze/thaw cycles. The measurement of lysosomal enzyme activities in cerebrospinal fluid is reliable and reproducible if pre-analytical factors are accurately taken into consideration. Therefore, the analytical recommendations that ensue from this study may contribute to the establishment of actual values for the activities of cerebrospinal fluid lysosomal enzymes as putative biomarkers for Parkinson's disease and other neurodegenerative disorders.

  9. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Directory of Open Access Journals (Sweden)

    G.B. Peres

    2014-06-01

    Full Text Available It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old, while 26 age-matched controls received only vehicle. The livers were removed on either the 10th or the 30th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA of cathepsins B and L was also decreased on the 10th, but not on the 30th day. Sulfatase decreased 30% on the 30th day, while glycosidases did not vary (or presented a transitory and slight decrease. There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  10. Arsenic induces apoptosis by the lysosomal-mitochondrial pathway in INS-1 cells.

    Science.gov (United States)

    Pan, Xiao; Jiang, Liping; Zhong, Laifu; Geng, Chengyan; Jia, Li; Liu, Shuang; Guan, Huai; Yang, Guang; Yao, Xiaofeng; Piao, Fengyuan; Sun, Xiance

    2016-02-01

    Recently, long term arsenic exposure was considered to be associated with an increased risk of diabetes mellitus. While a relation of cause-and-effect between apoptosis of pancreatic β-cells and arsenic exposure, the precise mechanisms of these events remains unclear. The aim of this study was to explore arsenic-induced pancreatic β-cell apoptosis and the mechanisms of through the possible link between lysosomal and the mitochondrial apoptotic pathway. After exposure to 10 μM of arsenic, the reactive oxygen species (ROS) level was significantly increased at 12 h, while the mitochondrial membrane potential was reduced at 24 h and the lysosomal membrane integrity was disrupted at 48 h. A significant increase in protein expression for cytochrome c was also observed using Western blot analysis after exposure to arsenic for 48 h. To further demonstrate that arsenic reduced the lysosomal membrane integrity, cells pretreated with NH4 Cl and exposed to arsenic harbored a lower fluorescence increase than cells that were only exposed to arsenic. In addition, apoptosis was mesured using Hoechst 33342/PI dual staining by microscopy and annexin V-FITC/propidium iodide dual staining by flow cytometry. The results show an increased uptake of the arsenic dose and the cells changed from dark blue to light blue, karyopyknosis, nuclear chromatin condensation, side set or fracture, and a correlation was found between the number of apoptotic cells and arsenic dose. The result of present study suggest that arsenic may induce pancreatic β-cell apoptosis through activation of the lysosome-mitochondrial pathway.

  11. A genetic screen in Drosophila reveals novel cytoprotective functions of the autophagy-lysosome pathway.

    Directory of Open Access Journals (Sweden)

    Andrew M Arsham

    Full Text Available The highly conserved autophagy-lysosome pathway is the primary mechanism for breakdown and recycling of macromolecular and organellar cargo in the eukaryotic cell. Autophagy has recently been implicated in protection against cancer, neurodegeneration, and infection, and interest is increasing in additional roles of autophagy in human health, disease, and aging. To search for novel cytoprotective features of this pathway, we carried out a genetic mosaic screen for mutations causing increased lysosomal and/or autophagic activity in the Drosophila melanogaster larval fat body. By combining Drosophila genetics with live-cell imaging of the fluorescent dye LysoTracker Red and fixed-cell imaging of autophagy-specific fluorescent protein markers, the screen was designed to identify essential metazoan genes whose disruption causes increased flux through the autophagy-lysosome pathway. The screen identified a large number of genes associated with the protein synthesis and ER-secretory pathways (e.g. aminoacyl tRNA synthetases, Oligosaccharyl transferase, Sec61alpha, and with mitochondrial function and dynamics (e.g. Rieske iron-sulfur protein, Dynamin-related protein 1. We also observed that increased lysosomal and autophagic activity were consistently associated with decreased cell size. Our work demonstrates that disruption of the synthesis, transport, folding, or glycosylation of ER-targeted proteins at any of multiple steps leads to autophagy induction. In addition to illuminating cytoprotective features of autophagy in response to cellular damage, this screen establishes a genetic methodology for investigating cell biological phenotypes in live cells, in the context of viable wild type organisms.

  12. SIRT1 regulates accumulation of oxidized LDL in HUVEC via the autophagy-lysosomal pathway.

    Science.gov (United States)

    Zhang, Yanlin; Sun, Juanjuan; Yu, Xiaoyan; Shi, Luyao; Du, Wenxiu; Hu, Lifang; Liu, Chunfeng; Cao, Yongjun

    2016-01-01

    Autophagy is involved in the degradation of oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs). Sirtuin1 (SIRT1), a new anti-atherosclerotic factor, can induce autophagy in cardiac myocytes. In the present study, we observed the effect of SIRT1 on the accumulation of ox-LDL in HUVECs, and elucidated whether its effect is relative with the autophagy-lysosomal pathway. The results showed that treatment with either SIRT1 siRNA or SIRT1 inhibitor nicotinamide (NAM) increased Dil-labelled-ox-LDL (Dil-ox-LDL) accumulation in HUVECs, and the SIRT1 inducer resveratrol (RSV) decreased it. Knockdown of autophagy-related protein 5 or inhibit the lysosomal degradation by chloroquine (CQ) decreased the effect of RSV. In HUVECs with ox-LDL, expression of LC3II and LC3 puncta was decreased by treatment with SIRT1 siRNA or NAM, but increased by RSV treatment; sequestosome 1 p62 expression showed the opposite effects. Moreover, Dil-ox-LDL combined with SIRT1 siRNA or NAM showed a much smaller degree of overlap of Lamp1 or Cathepsin D with Dil-ox-LDL than in cells with Dil-ox-LDL alone, and RSV treatment resulted in a greater degree of overlap. These results suggest that SIRT1 can decrease the accumulation of ox-LDL in HUVECs, and this effect is related to the autophagy-lysosomal pathway.

  13. Planar patch clamp approach to characterize ionic currents from intact lysosomes.

    Science.gov (United States)

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian

    2010-01-01

    Since its launch in the early 1980s, the patch clamp method has been extensively used to study ion channels in the plasma membrane, but its application to the study of intracellular ion channels has been limited. Unlike the plasma membrane, intracellular membranes are usually not stable enough to withstand mechanical manipulation by glass electrodes during seal formation and rupturing of the membrane. To circumvent these problems, we developed a method involving the immobilization of isolated organelles on a solid matrix planar glass chip. This glass chip contains a microstructured hole that supports the formation of gigaseals and subsequent electrophysiological recordings despite the high fragility of intracellular membranes. Here, we report the experimental details of this method using lysosomes, which are the smallest cellular organelles, as a model system. We demonstrate that we can record endogenous ionic currents from wild-type lysosomes, as well as from lysosomes overexpressing ion channels, and expect that this method will provide electrophysiological access to a broad range of intracellular ion channels.

  14. Lack of the Lysosomal Membrane Protein, GLMP, in Mice Results in Metabolic Dysregulation in Liver.

    Directory of Open Access Journals (Sweden)

    Xiang Yi Kong

    Full Text Available Ablation of glycosylated lysosomal membrane protein (GLMP, formerly known as NCU-G1 has been shown to cause chronic liver injury which progresses into liver fibrosis in mice. Both lysosomal dysfunction and chronic liver injury can cause metabolic dysregulation. Glmp gt/gt mice (formerly known as Ncu-g1gt/gt mice were studied between 3 weeks and 9 months of age. Body weight gain and feed efficiency of Glmp gt/gt mice were comparable to wild type siblings, only at the age of 9 months the Glmp gt/gt siblings had significantly reduced body weight. Reduced size of epididymal fat pads was accompanied by hepatosplenomegaly in Glmp gt/gt mice. Blood analysis revealed reduced levels of blood glucose, circulating triacylglycerol and non-esterified fatty acids in Glmp gt/gt mice. Increased flux of glucose, increased de novo lipogenesis and lipid accumulation were detected in Glmp gt/gt primary hepatocytes, as well as elevated triacylglycerol levels in Glmp gt/gt liver homogenates, compared to hepatocytes and liver from wild type mice. Gene expression analysis showed an increased expression of genes involved in fatty acid uptake and lipogenesis in Glmp gt/gt liver compared to wild type. Our findings are in agreement with the metabolic alterations observed in other mouse models lacking lysosomal proteins, and with alterations characteristic for advanced chronic liver injury.

  15. Alpha Adrenergic Induction of Transport of Lysosomal Enzyme across the Blood-Brain Barrier.

    Directory of Open Access Journals (Sweden)

    Akihiko Urayama

    Full Text Available The impermeability of the adult blood-brain barrier (BBB to lysosomal enzymes impedes the ability to treat the central nervous system manifestations of lysosomal storage diseases. Here, we found that simultaneous stimulation of the alpha1 and alpha2 adrenoreceptor restores in adult mice the high rate of transport for the lysosomal enzyme P-GUS that is seen in neonates but lost with development. Beta adrenergics, other monoamines, and acetylcholine did not restore this transport. A high dose (500 microg/mouse of clonidine, a strong alpha2 and weak alpha1 agonist, was able to act as monotherapy in the stimulation of P-GUS transport. Neither use of alpha1 plus alpha2 agonists nor the high dose clonidine disrupted the BBB to albumin. In situ brain perfusion and immunohistochemistry studies indicated that adrengerics act on transporters already at the luminal surface of brain endothelial cells. These results show that adrenergic stimulation, including monotherapy with clonidine, could be key for CNS enzyme replacement therapy.

  16. Quantitative Differences in the Urinary Proteome of Siblings Discordant for Type 1 Diabetes Include Lysosomal Enzymes.

    Science.gov (United States)

    Suh, Moo-Jin; Tovchigrechko, Andrey; Thovarai, Vishal; Rolfe, Melanie A; Torralba, Manolito G; Wang, Junmin; Adkins, Joshua N; Webb-Robertson, Bobbie-Jo M; Osborne, Whitney; Cogen, Fran R; Kaplowitz, Paul B; Metz, Thomas O; Nelson, Karen E; Madupu, Ramana; Pieper, Rembert

    2015-08-01

    Individuals with type 1 diabetes (T1D) often have higher than normal blood glucose levels, causing advanced glycation end product formation and inflammation and increasing the risk of vascular complications years or decades later. To examine the urinary proteome in juveniles with T1D for signatures indicative of inflammatory consequences of hyperglycemia, we profiled the proteome of 40 T1D patients with an average of 6.3 years after disease onset and normal or elevated HbA1C levels, in comparison with a cohort of 41 healthy siblings. Using shotgun proteomics, 1036 proteins were identified, on average, per experiment, and 50 proteins showed significant abundance differences using a Wilcoxon signed-rank test (FDR q-value ≤ 0.05). Thirteen lysosomal proteins were increased in abundance in the T1D versus control cohort. Fifteen proteins with functional roles in vascular permeability and adhesion were quantitatively changed, including CD166 antigen and angiotensin-converting enzyme 2. α-N-Acetyl-galactosaminidase and α-fucosidase 2, two differentially abundant lysosomal enzymes, were detected in western blots with often elevated quantities in the T1D versus control cohort. Increased release of proteins derived from lysosomes and vascular epithelium into urine may result from hyperglycemia-associated inflammation in the kidney vasculature.

  17. Unfolded protein response activates glycogen synthase kinase-3 via selective lysosomal degradation.

    Science.gov (United States)

    Nijholt, Diana A T; Nölle, Anna; van Haastert, Elise S; Edelijn, Hessel; Toonen, Ruud F; Hoozemans, Jeroen J M; Scheper, Wiep

    2013-07-01

    The unfolded protein response (UPR) is a stress response that is activated upon disturbed homeostasis in the endoplasmic reticulum. In Alzheimer's disease, as well as in other tauopathies, the UPR is activated in neurons that contain early tau pathology. A recent genome-wide association study identified genetic variation in a UPR transducer as a risk factor for tauopathy, supporting a functional connection between UPR activation and tau pathology. Here we show that UPR activation increases the activity of the major tau kinase glycogen synthase kinase (GSK)-3 in vitro via a selective removal of inactive GSK-3 phosphorylated at Ser(21/9). We demonstrate that this is mediated by the autophagy/lysosomal pathway. In brain tissue from patients with different tauopathies, lysosomal accumulations of pSer(21/9) GSK-3 are found in neurons with markers for UPR activation. Our data indicate that UPR activation increases the activity of GSK-3 by a novel mechanism, the lysosomal degradation of the inactive pSer(21/9) GSK-3. This may provide a functional explanation for the close association between UPR activation and early tau pathology in neurodegenerative diseases.

  18. Characterization of lysosome-destabilizing DOPE/PLGA nanoparticles designed for cytoplasmic drug release.

    Science.gov (United States)

    Chhabra, Resham; Grabrucker, Andreas M; Veratti, Patrizia; Belletti, Daniela; Boeckers, Tobias M; Vandelli, Maria Angela; Forni, Flavio; Tosi, Giovanni; Ruozi, Barbara

    2014-08-25

    Polymeric nanoparticles (NPs) offer a promising approach for therapeutic intracellular delivery of proteins, conventionally hampered by short half-lives, instability and immunogenicity. Remarkably, NPs uptake occurs via endocytic internalization leading to NPs content's release within lysosomes. To overcome lysosomal degradation and achieve NPs and/or loaded proteins release into cytosol, we propose the formulation of hybrid NPs by adding 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as pH sensitive component in the formulation of poly-lactide-co-glycolide (PLGA) NPs. Hybrid NPs, featured by different DOPE/PLGA ratios, were characterized in terms of structure, stability and lipid organization within the polymeric matrix. Experiments on NIH cells and rat primary neuronal cultures highlighted the safety profile of hybrid NPs. Moreover, after internalization, NPs are able to transiently destabilize the integrity of lysosomes in which they are taken up, speeding their escape and favoring cytoplasmatic localization. Thus, these DOPE/PLGA-NPs configure themselves as promising carriers for intracellular protein delivery.

  19. A lysosome-targeted drug delivery system based on sorbitol backbone towards efficient cancer therapy.

    Science.gov (United States)

    Maniganda, Santhi; Sankar, Vandana; Nair, Jyothi B; Raghu, K G; Maiti, Kaustabh K

    2014-09-14

    A straightforward synthetic approach was adopted for the construction of a lysosome-targeted drug delivery system (TDDS) using sorbitol scaffold (Sor) linked to octa-guanidine and tetrapeptide GLPG, a peptide substrate of lysosomal cysteine protease, cathepsin B. The main objective was to efficiently deliver the potential anticancer drug, doxorubicin to the target sites, thereby minimizing dose-limiting toxicity. Three TDDS vectors were synthesized viz., DDS1: Sor-GLPG-Fl, DDS2: Sor-Fl (control) and DDS3: Sor-GLPGC-SMCC-Dox. Dox release from DDS3 in the presence of cathepsin B was studied by kinetics measurement based on the fluorescent property of Dox. The cytotoxicity of DDS1 was assessed and found to be non-toxic. Cellular internalization and colocalization studies of all the 3 systems were carried out by flow cytometry and confocal microscopy utilizing cathepsin B-expressing HeLa cells. DDS1 and DDS3 revealed significant localization within the lysosomes, in contrast to DDS2 (control). The doxorubicin-conjugated carrier, DDS3, demonstrated significant cytotoxic effect when compared to free Dox by MTT assay and also by flow cytometric analysis. The targeted approach with DDS3 is expected to be promising, because it is indicated to be advantageous over free Dox, which possesses dose-limiting toxicity, posing risk of injury to normal tissues.

  20. LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium.

    Science.gov (United States)

    Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

    2016-07-01

    Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.

  1. Hormonal and cholinergic influences on pancreatic lysosomal and digestive enzymes in rats.

    Science.gov (United States)

    Evander, A; Ihse, I; Lundquist, I

    1983-01-01

    Hormonal and cholinergic influences on lysosomal and digestive enzyme activities in pancreatic tissue were studied in normal adult rats. Hormonal stimulation by the cholecystokinin analogue, caerulein, induced a marked enhancement of the activities of cathepsin D and N-acetyl-beta-D-glucosaminidase in pancreatic tissue, whereas the activities of amylase and lipase tended to decrease. Acid phosphatase activity was not affected. Further, caerulein was found to induce a significant increase of cathepsin D output in bile-pancreatic juice. This output largely parallelled that of amylase. Cholinergic stimulation by the muscarinic agonist carbachol, at a dose level giving the same output of amylase as caerulein, did not affect pancreatic activities of cathepsin D and N-acetyl-beta-D-glucosaminidase. Further, cholinergic stimulation induced an increase of amylase activity and a slight decrease of acid phosphatase activity in pancreatic tissue. Lipase activity was not affected. No apparent effect on cathepsin D output in bile-pancreatic juice was encountered after cholinergic stimulation. The activities of neither the digestive nor the lysosomal enzymes were influenced by the administration of secretin. The results suggest a possible lysosomal involvement in caerulein-induced secretion and/or inactivation of pancreatic digestive enzymes, whereas cholinergic stimulation seems to act through different mechanisms.

  2. Disintegration of lysosomes mediated by GTPgammaS-treated cytosol: possible involvement of phospholipases.

    Science.gov (United States)

    Sai, Y; Matsuda, T; Arai, K; Ohkuma, S

    1998-04-01

    We showed previously that cytosol treated with guanosine 5'-O-(3-thiotriphosphate) (GTP-gammaS) disintegrated lysosomes in vitro [Sai, Y. et al. (1994) Biochem. Biophys. Res. Commun. 198, 869-877] in time-, temperature-, and dose-dependent manners. This also requires ATP, however, the latter can be substituted with deoxy-ATP, ADP, or ATPgammaS, suggesting no requirement of ATP hydrolysis. The lysis was inhibited by several chemical modifiers, including N-ethylmaleimide, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, and by various phospholipase inhibitors (trifluoperazine, p-bromophenacyl bromide, nordihydroguaiaretic acid, W-7, primaquine, compound 48/80, neomycin, and gentamicin), but not by ONO-RS-082, an inhibitor of phospholipase A2. The reaction was also inhibited by phospholipids (phosphatidylinositol, phosphatidylserine, phosphatidic acid, and phosphatidylcholine) and diacylglycerol. Among the phospholipase A2 hydrolysis products of phospholipids, unsaturated fatty acids (oleate, linoleate, and arachidonate) and lysophospholipid (lysophosphatidylcholine) by themselves broke lysosomes down directly, whereas saturated fatty acids (palmitate and stearate) had little effect. We found that GTPgammaS-stimulated cytosolic phospholipase A2 activity was highly sensitive to ONO-RS-082. These results suggest the participation of phospholipase(s), though not cytosolic phospholipase A2, in the GTPgammaS-dependent lysis of lysosomes.

  3. Investigation of endosome and lysosome biology by ultra pH-sensitive nanoprobes.

    Science.gov (United States)

    Wang, Chensu; Zhao, Tian; Li, Yang; Huang, Gang; White, Michael A; Gao, Jinming

    2016-09-06

    Endosomes and lysosomes play a critical role in various aspects of cell physiology such as nutrient sensing, receptor recycling, protein/lipid catabolism, and cell death. In drug delivery, endosomal release of therapeutic payloads from nanocarriers is also important in achieving efficient delivery of drugs to reach their intracellular targets. Recently, we invented a library of ultra pH-sensitive (UPS) nanoprobes with exquisite fluorescence response to subtle pH changes. The UPS nanoprobes also displayed strong pH-specific buffer effect over small molecular bases with broad pH responses (e.g., chloroquine and NH4Cl). Tunable pH transitions from 7.4 to 4.0 of UPS nanoprobes cover the entire physiological pH of endocytic organelles (e.g., early and late endosomes) and lysosomes. These unique physico-chemical properties of UPS nanoprobes allowed a 'detection and perturbation' strategy for the investigation of luminal pH in cell signaling and metabolism, which introduces a nanotechnology-enabled paradigm for the biological studies of endosomes and lysosomes.

  4. PV modules without bypass diodes; PV-Module ohne Bypass-Dioden? - Untersuchungen an einer PV-Fassade

    Energy Technology Data Exchange (ETDEWEB)

    Laukamp, H.; Kresse, A.; Leithold, W. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)]|[Ingenieurbuero A. Kresse, Karlsruhe (Germany)]|[Solare Systemtechnik GmbH, Freiburg (Germany)

    1998-12-01

    In order to protect solar modules against high output losses with non-homogeneous irradiation, bypass diodes which are mostly accommodated in the module connection socket are used. One would often gladly dispense with these connection sockets for integration of customer-specific large modules in facades. The question: ``Where will the diodes go?`` must then be satisfactorily answered. Both laminating the diodes in the module and their external accommodation cause extra expense elsewhere. It would be ideal if one could dispense with the bypass diodes altogether. This article tries to answer the question, in what conditions this is possible. Starting from the PV facade `Freiburg solar centre`, where one dispensed with the protective diodes, investigations are carried out experimentally and by means of simulation calculations. [Deutsch] Um Solarmodule bei inhomogener Bestrahlung vor hohen Verlustleistungen zu schuetzen, werden ueblicherweise Bypass-Dioden eingesetzt, die zumeist in der Modulanschlussdose untergebracht sind. Zur Fassadenintegration von kundenspezifischen Grossmodulen wuerde man manchmal gerne auf die Anschlussdosen verzichten. Hierfuer muesste zunaechst die Frage `wohin mit den Dioden?` befriedigend beantwortet werden. Sowohl die Einlaminierung der Dioden in das Modul, als auch deren externe Unterbringung versursachen an anderer Stelle einen erhoehten Aufwand. Ideal waere es, wenn man auf die Bypass-Dioden ganz verzichten koennte. Die vorliegende Arbeit versucht die Frage zu beantworten, unter welchen Bedingungen dies moeglich ist. Ausgehend von der PV-Fassade `Solarzentrum Freiburg` - hier wurde auf den Einsatz von Schutzdioden verzichtet - werden experimentell und mittels Simulationsrechnungen Untersuchungen durchgefuehrt. (orig./RHM)

  5. Endocytic pathway rapidly delivers internalized molecules to lysosomes: an analysis of vesicle trafficking, clustering and mass transfer.

    Science.gov (United States)

    Pangarkar, Chinmay; Dinh, Anh-Tuan; Mitragotri, Samir

    2012-08-20

    Lysosomes play a critical role in intracellular drug delivery. For enzyme-based therapies, they represent a potential target site whereas for nucleic acid or many protein drugs, they represent the potential degradation site. Either way, understanding the mechanisms and processes involved in routing of materials to lysosomes after cellular entry is of high interest to the field of drug delivery. Most therapeutic cargoes other than small hydrophobic molecules enter the cells through endocytosis. Endocytosed cargoes are routed to lysosomes via microtubule-based transport and are ultimately shared by various lysosomes via tethering and clustering of endocytic vesicles followed by exchange of their contents. Using a combined experimental and numerical approach, here we studied the rates of mass transfer into and among the endocytic vesicles in a model cell line, 3T3 fibroblasts. In order to understand the relationship of mass transfer with microtubular transport and vesicle clustering, we varied both properties through various pharmacological agents. At the same time, microtubular transport and vesicle clustering were modeled through diffusion-advection equations and the Smoluchowski equations, respectively. Our analysis revealed that the rate of mass transfer is optimally related to microtubular transport and clustering properties of vesicles. Further, the rate of mass transfer is highest in the innate state of the cell. Any perturbation to either microtubular transport or vesicle aggregation led to reduced mass transfer to lysosome. These results suggest that in the absence of an external intervention the endocytic pathway appears to maximize molecular delivery to lysosomes. Strategies are discussed to reduce mass transfer to lysosomes so as to extend the residence time of molecules in endosomes or late endosomes, thus potentially increasing the likelihood of their escape before disposition in the lysosomes.

  6. Long-term patency of superficial temporal artery to middle cerebral artery bypass for cerebral atherosclerotic disease: factors determining the bypass patent.

    Science.gov (United States)

    Matano, Fumihiro; Murai, Yasuo; Tateyama, Kojiro; Tamaki, Tomonori; Mizunari, Takayuki; Matsukawa, Hideoshi; Teramoto, Akira; Morita, Akio

    2016-10-01

    Long-term patency of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery for atherosclerotic disease and associated risk factors for loss of patency have rarely been discussed. We retrospectively analyzed long-term patency following STA-MCA bypass and evaluated various demographic and clinical factors to identify the ones predictive of postsurgical loss of patency using records of 84 revascularization procedures (58 patients, 45 males; mean age at surgery 63.6 years, range 31-78 years). Bypass patency was diagnosed based on magnetic resonance angiography or three-dimensional computed tomography. The mean follow-up period was 24.7 months (range 6-63 months). Decreased bypass patency was observed in 4 of 58 patients (6.9 %) who collectively underwent 6 bypasses (7.1 %) of 84. All cases of decreased bypass patency were first detected within 6 months of surgery. Bypass patency was not correlated with age, sex, number of anastomoses, postoperative cerebral infarction, or control of postoperative diabetes mellitus. We found a significant association of bypass patency with hyperperfusion (p = 0.01) and postoperative smoking (p = 0.0036). Furthermore, we found a significant association of hyperperfusion with STA diameter (p bypass patency in cerebral atherosclerotic disease patients. Careful monitoring of patency to prevent hyperperfusion and cessation of smoking are recommended, particularly within 6 months of the surgery.

  7. Iron-Mediated Lysosomal Membrane Permeabilization in Ethanol-Induced Hepatic Oxidative Damage and Apoptosis: Protective Effects of Quercetin.

    Science.gov (United States)

    Li, Yanyan; Chen, Man; Xu, Yanyan; Yu, Xiao; Xiong, Ting; Du, Min; Sun, Jian; Liu, Liegang; Tang, Yuhan; Yao, Ping

    2016-01-01

    Iron, in its free ferrous states, can catalyze Fenton reaction to produce OH∙, which is recognized as a crucial role in the pathogenesis of alcoholic liver diseases (ALD). As a result of continuous decomposition of iron-containing compounds, lysosomes contain a pool of redox-active iron. To investigate the important role of intralysosomal iron in alcoholic liver injury and the potential protection of quercetin, male C57BL/6J mice fed by Lieber De Carli diets containing ethanol (30% of total calories) were cotreated by quercetin or deferoxamine (DFO) for 15 weeks and ethanol-incubated mice primary hepatocytes were pretreated with FeCl3, DFO, and bafilomycin A1 at their optimal concentrations and exposure times. Chronic ethanol consumption caused an evident increase in lysosomal redox-active iron accompanying sustained oxidative damage. Iron-mediated ROS could trigger lysosomal membrane permeabilization (LMP) and subsequent mitochondria apoptosis. The hepatotoxicity was attenuated by reducing lysosomal iron while being exacerbated by escalating lysosomal iron. Quercetin substantially alleviated the alcoholic liver oxidative damage and apoptosis by decreasing lysosome iron and ameliorating iron-mediated LMP, which provided a new prospective of the use of quercetin against ALD.

  8. Preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in experimentally induced myocardial infarction.

    Science.gov (United States)

    Jyoti Roy, Abhro; Stanely Mainzen Prince, P

    2013-01-15

    The present study was designed to evaluate the preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Male albino Wistar rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days after which isoproterenol (100mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24h (8th and 9th day).The activity/levels of serum cardiac diagnostic markers, heart lysosomal lipid peroxidation products and the activities of lysosomal enzymes (β-glucuronidase, β-galactosidase, cathepsin-B and cathepsin-D) were significantly (Plysosomal fraction. The pretreatment with p-coumaric acid significantly (Plysosomal lipid peroxidation products and the activities of lysosomal enzymes. In addition, p-coumaric acid greatly reduced myocardial infarct size. p-Coumaric acid pretreatment (8 mg/kg body weight) to normal rats did not show any significant effect. Thus, this study showed that p-coumaric acid prevents lysosomal dysfunction against cardiac damage induced by isoproterenol and brings back the levels of lipid peroxidation products and activities of lysosomal enzymes to near normal levels. The in vitro study also revealed the free radical scavenging activity of p-coumaric acid. Thus, the observed effects are due to p-coumaric acid's free radical scavenging and membrane stabilizing properties.

  9. Polyketide synthase (PKS) reduces fusion of Legionella pneumophila-containing vacuoles with lysosomes and contributes to bacterial competitiveness during infection.

    Science.gov (United States)

    Shevchuk, Olga; Pägelow, Dennis; Rasch, Janine; Döhrmann, Simon; Günther, Gabriele; Hoppe, Julia; Ünal, Can Murat; Bronietzki, Marc; Gutierrez, Maximiliano Gabriel; Steinert, Michael

    2014-11-01

    L. pneumophila-containing vacuoles (LCVs) exclude endocytic and lysosomal markers in human macrophages and protozoa. We screened a L. pneumophila mini-Tn10 transposon library for mutants, which fail to inhibit the fusion of LCVs with lysosomes by loading of the lysosomal compartment with colloidal iron dextran, mechanical lysis of infected host cells, and magnetic isolation of LCVs that have fused with lysosomes. In silico analysis of the mutated genes, D. discoideum plaque assays and infection assays in protozoa and U937 macrophage-like cells identified well established as well as novel putative L. pneumophila virulence factors. Promising candidates were further analyzed for their co-localization with lysosomes in host cells using fluorescence microscopy. This approach corroborated that the O-methyltransferase, PilY1, TPR-containing protein and polyketide synthase (PKS) of L. pneumophila interfere with lysosomal degradation. Competitive infections in protozoa and macrophages revealed that the identified PKS contributes to the biological fitness of pneumophila strains and may explain their prevalence in the epidemiology of Legionnaires' disease.

  10. Ca2+ -regulated lysosome fusion mediates angiotensin II-induced lipid raft clustering in mesenteric endothelial cells.

    Science.gov (United States)

    Han, Wei-Qing; Chen, Wen-Dong; Zhang, Ke; Liu, Jian-Jun; Wu, Yong-Jie; Gao, Ping-Jin

    2016-04-01

    It has been reported that intracellular Ca2+ is involved in lysosome fusion and membrane repair in skeletal cells. Given that angiotensin II (Ang II) elicits an increase in intracellular Ca2+ and that lysosome fusion is a crucial mediator of lipid raft (LR) clustering, we hypothesized that Ang II induces lysosome fusion and activates LR formation in rat mesenteric endothelial cells (MECs). We found that Ang II acutely increased intracellular Ca2+ content, an effect that was inhibited by the extracellular Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) and the inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release inhibitor 2-aminoethoxydiphenyl borate (2-APB). Further study showed that EGTA almost completely blocked Ang II-induced lysosome fusion, the translocation of acid sphingomyelinase (ASMase) to LR clusters, ASMase activation and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activation. In contrast, 2-APB had a slight inhibitory effect. Functionally, both the lysosome inhibitor bafilomycin A1 and the ASMase inhibitor amitriptyline reversed Ang II-induced impairment of vasodilation. We conclude that Ca2+ -regulated lysosome fusion mediates the Ang II-induced regulation of the LR-redox signaling pathway and mesenteric endothelial dysfunction.

  11. ESCRT-Dependent Cell Death in a Caenorhabditis elegans Model of the Lysosomal Storage Disorder Mucolipidosis Type IV.

    Science.gov (United States)

    Huynh, Julie M; Dang, Hope; Munoz-Tucker, Isabel A; O'Ketch, Marvin; Liu, Ian T; Perno, Savannah; Bhuyan, Natasha; Crain, Allison; Borbon, Ivan; Fares, Hanna

    2016-02-01

    Mutations in MCOLN1, which encodes the cation channel protein TRPML1, result in the neurodegenerative lysosomal storage disorder Mucolipidosis type IV. Mucolipidosis type IV patients show lysosomal dysfunction in many tissues and neuronal cell death. The ortholog of TRPML1 in Caenorhabditis elegans is CUP-5; loss of CUP-5 results in lysosomal dysfunction in many tissues and death of developing intestinal cells that results in embryonic lethality. We previously showed that a null mutation in the ATP-Binding Cassette transporter MRP-4 rescues the lysosomal defect and embryonic lethality of cup-5(null) worms. Here we show that reducing levels of the Endosomal Sorting Complex Required for Transport (ESCRT)-associated proteins DID-2, USP-50, and ALX-1/EGO-2, which mediate the final de-ubiquitination step of integral membrane proteins being sequestered into late endosomes, also almost fully suppresses cup-5(null) mutant lysosomal defects and embryonic lethality. Indeed, we show that MRP-4 protein is hypo-ubiquitinated in the absence of CUP-5 and that reducing levels of ESCRT-associated proteins suppresses this hypo-ubiquitination. Thus, increased ESCRT-associated de-ubiquitinating activity mediates the lysosomal defects and corresponding cell death phenotypes in the absence of CUP-5.

  12. Azadirachtin-induced apoptosis involves lysosomal membrane permeabilization and cathepsin L release in Spodoptera frugiperda Sf9 cells.

    Science.gov (United States)

    Wang, Zheng; Cheng, Xingan; Meng, Qianqian; Wang, Peidan; Shu, Benshui; Hu, Qiongbo; Hu, Meiying; Zhong, Guohua

    2015-07-01

    Azadirachtin as a kind of botanical insecticide has been widely used in pest control. We previously reported that azadirachtin could induce apoptosis of Spodoptera litura cultured cell line Sl-1, which involves in the up-regulation of P53 protein. However, the detailed mechanism of azadirachtin-induced apoptosis is not clearly understood in insect cultured cells. The aim of the present study was to address the involvement of lysosome and lysosomal protease in azadirachtin-induced apoptosis in Sf9 cells. The result confirmed that azadirachtin indeed inhibited proliferation and induced apoptosis. The lysosomes were divided into different types as time-dependent manner, which suggested that changes of lysosomes were necessarily physiological processes in azadirachtin-induced apoptosis in Sf9 cells. Interestingly, we noticed that azadirachtin could trigger lysosomal membrane permeabilization and cathepsin L releasing to cytosol. Z-FF-FMK (a cathepsin L inhibitor), but not CA-074me (a cathepsin B inhibitor), could effectively hinder the apoptosis induced by azadirachtin in Sf9 cells. Meanwhile, the activity of caspase-3 could also be inactivated by the inhibition of cathepsin L enzymatic activity induced by Z-FF-FMK. Taken together, our findings suggest that azadirachtin could induce apoptosis in Sf9 cells in a lysosomal pathway, and cathepsin L plays a pro-apoptosis role in this process through releasing to cytosol and activating caspase-3.

  13. Iron-Mediated Lysosomal Membrane Permeabilization in Ethanol-Induced Hepatic Oxidative Damage and Apoptosis: Protective Effects of Quercetin

    Directory of Open Access Journals (Sweden)

    Yanyan Li

    2016-01-01

    Full Text Available Iron, in its free ferrous states, can catalyze Fenton reaction to produce OH∙, which is recognized as a crucial role in the pathogenesis of alcoholic liver diseases (ALD. As a result of continuous decomposition of iron-containing compounds, lysosomes contain a pool of redox-active iron. To investigate the important role of intralysosomal iron in alcoholic liver injury and the potential protection of quercetin, male C57BL/6J mice fed by Lieber De Carli diets containing ethanol (30% of total calories were cotreated by quercetin or deferoxamine (DFO for 15 weeks and ethanol-incubated mice primary hepatocytes were pretreated with FeCl3, DFO, and bafilomycin A1 at their optimal concentrations and exposure times. Chronic ethanol consumption caused an evident increase in lysosomal redox-active iron accompanying sustained oxidative damage. Iron-mediated ROS could trigger lysosomal membrane permeabilization (LMP and subsequent mitochondria apoptosis. The hepatotoxicity was attenuated by reducing lysosomal iron while being exacerbated by escalating lysosomal iron. Quercetin substantially alleviated the alcoholic liver oxidative damage and apoptosis by decreasing lysosome iron and ameliorating iron-mediated LMP, which provided a new prospective of the use of quercetin against ALD.

  14. Numerical analysis for the matching of the core driven compression system in a double bypass engine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin; LIU Bao-jie

    2011-01-01

    The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this paper. The system consists of a one-stage-core driven fan stage (CDFS), an inner bypass duet and a five-stage high pressure compressor (HPC), providing two basic operating modes: the single bypass mode and the double bypass mode. Variable vanes are necessary to realize the mode switch of the system. The correct matching in the double bypass mode requires a proper combination of the mass flow, total pressure ratio and blade speed. The work capacity of the system decreases in the double bypass mode and the pressure ratio tends to decrease more for the CDFS and the front stages of the HPC. The overall system efficiency is higher in the double bypass mode. The radial distributions of aerodynamic parameters are similar in different modes. The notable redistribution of mass flow downstream the CDFS in the single bypass mode leads to strong radial flows and additional mixing losses. The absolute flow angles into the inner bypass increase for the inner span and decrease for the outer span when the system is switched from the single bypass mode to the double bypass mode.

  15. Arterial pressure and deltoid muscle gas tensions during cardiopulmonary bypass in man.

    Science.gov (United States)

    Stanley, T H

    1978-07-01

    The results of this study demonstrate that standard techniques of conducting cardiopulmonary bypass produce low muscle oxygen and high muscle carbon dioxide tensions and, thus, little perfusion of skeletal muscle. Our findings also show that PmO2 and PmCO2 do not return to pre-bypass levels until the mean arterial blood pressure exceeds 12 kPa (90 torr) during bypass and that utilization of vasopressor drugs during bypass maintains the pressure; but at the expense of muscle blood flow. The data indicate that both high mean blood pressure and high flow are necessary during bypass to ensure skeletal muscle perfusion and suggest, when combined with preliminary animal findings, that this type of bypass perfusion may prove to be superior to standard techniques in hastening recovery after cardio-pulmonary bypass.

  16. Contribution of mitochondria and lysosomes to photodynamic therapy-induced death in cancer cells

    Science.gov (United States)

    Nieminen, Anna-Liisa; Azizuddin, Kashif; Zhang, Ping; Kenney, Malcolm E.; Pediaditakis, Peter; Lemasters, John J.; Oleinick, Nancy L.

    2008-02-01

    In photodynamic therapy (PDT), visible light activates a photosensitizing drug added to a tissue, resulting in singlet oxygen formation and cell death. Employing confocal microscopy, we previously found that the phthalocyanine Pc 4 localized primarily to mitochondrial membranes in various cancer cell lines, resulting in mitochondrial reactive oxygen species (ROS) production, followed by inner membrane permeabilization (mitochondrial permeability transition) with mitochondrial depolarization and swelling, which in turn led to cytochrome c release and apoptotic death. Recently, derivatives of Pc 4 with OH groups added to one of the axial ligands were synthesized. These derivatives appeared to be taken up more avidly by cells and caused more cytotoxicity than the parent compound Pc 4. Using organelle-specific fluorophores, we found that one of these derivatives, Pc 181, accumulated into lysosomes and that PDT with Pc 181 caused rapid disintegration of lysosomes. We hypothesized that chelatable iron released from lysosomes during PDT contributes to mitochondrial damage and subsequent cell death. We monitored cytosolic Fe2+ concentrations after PDT with calcein. Fe2+ binds to calcein causing quenching of calcein fluorescence. After bafilomycin, an inhibitor of the vacuolar proton-translocating ATPase, calcein fluorescence became quenched, an effect prevented by starch desferal s-DFO, an iron chelator that enters cells by endocytosis. After Pc 181-PDT, cytosolic calcein fluorescence also decreased, indicating increased chelatable Fe2+ in the cytosol, and apoptosis occurred. s-DFO decreased Pc 181-PDT-induced apoptosis as measured by a decrease of caspase-3 activation. In isolated mitochondria preparations, Fe2+ induced mitochondrial swelling, which was prevented by Ru360, an inhibitor of the mitochondrial Ca2+ uniporter. The data support a hypothesis of oxidative injury in which Pc 181-PDT disintegrates lysosomes and releases constituents that synergistically promote

  17. Protective effects of positive lysosomal modulation in Alzheimer's disease transgenic mouse models.

    Science.gov (United States)

    Butler, David; Hwang, Jeannie; Estick, Candice; Nishiyama, Akiko; Kumar, Saranya Santhosh; Baveghems, Clive; Young-Oxendine, Hollie B; Wisniewski, Meagan L; Charalambides, Ana; Bahr, Ben A

    2011-01-01

    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 Aβ(1-42). 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 APP(SwInd) 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 Aβ(x-42) sandwich ELISA measures in APP(SwInd) 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 Aβ(1-38) occurs as Aβ(1-42) 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 Aβ(1-42) 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

  18. Inhibitory effect of mTOR activator MHY1485 on autophagy: suppression of lysosomal fusion.

    Directory of Open Access Journals (Sweden)

    Yeon Ja Choi

    Full Text Available Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. Autophagic flux was measured to evaluate the autophagic activity. Autophagosomes were visualized in Ac2F cells transfected with AdGFP-LC3 by live-cell confocal microscopy. In addition, activity of mTOR, a major regulatory protein of autophagy, was assessed by western blot and docking simulation using AutoDock 4.2. In the result, treatment with MHY1485 suppressed the basal autophagic flux, and this inhibitory effect was clearly confirmed in cells under starvation, a strong physiological inducer of autophagy. The levels of p62 and beclin-1 did not show significant change after treatment with MHY1485. Decreased co-localization of autophagosomes and lysosomes in confocal microscopic images revealed the inhibitory effect of MHY1485 on lysosomal fusion during starvation-induced autophagy. These effects of MHY1485 led to the accumulation of LC3II and enlargement of the autophagosomes in a dose- and time-dependent manner. Furthermore, MHY1485 induced mTOR activation and correspondingly showed a higher docking score than PP242, a well-known ATP-competitive mTOR inhibitor, in docking simulation. In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel

  19. Protective effects of positive lysosomal modulation in Alzheimer's disease transgenic mouse models.

    Directory of Open Access Journals (Sweden)

    David Butler

    Full Text Available 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 Aβ(1-42. 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 APP(SwInd 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 Aβ(x-42 sandwich ELISA measures in APP(SwInd 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 Aβ(1-38 occurs as Aβ(1-42 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 Aβ(1-42 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

  20. Totally laparoscopic bypass surgery for aortoiliac occlusive disease in China

    Institute of Scientific and Technical Information of China (English)

    GUO Lian-rui; GU Yong-quan; QI Li-xing; TONG Zhu; WU Xin; GUO Jian-ming; ZHANG Jian

    2013-01-01

    Background Totally laparoscopic aortic surgery is still in its infancy in China.One of the factors preventing adoption of this technique is its steep learning curve.The objective of this study was to evaluate the feasibility and safety of laparoscopic surgery for aortoiliac occlusive disease (AIOD).Methods From November 2008 to November 2012,12 patients were treated for severe AIOD with a totally laparoscopic bypass surgery at our university hospital.The demographic data,operative data,postoperative recovery data,morbidity and mortality were analyzed and compared with those of conventional open approach.Results Twelve totally laparoscopic aortic surgery procedures,including two iliofemoral bypasses (IFB),three unilateral aortofemoral bypasses (UAFB),and seven aortobifemoral bypasses (ABFB),were performed.Conversion to open procedures was required in three patients.The mean operation time was 518 (range,325-840) minutes,mean blood loss was 962 (range,400-2500) ml,and mean aortic anastomosis time was 75 (range,40-150) minutes.Compared with conventional open approach for aortofemoral bypasses performed concomitantly during this period,laparoscopic patients required fewer narcotics and a shorter in-hospital stay and earlier recovery.Postoperative complications developed in four patients,including a single patient with transient left hydronephrosis,ischemic colonic fistula and pneumonia,residual aortic stenosis proximal to the anastomotic site,and asymptomatic partial left renal infarction.All patients recovered and were discharged on postoperative Days 7-14 except one patient that died of respiratory failure on Day 46.All grafts were patent with follow-up imaging performed by Duplex examination,with a mean follow-up time of 10.7 (range,2-61) months.Conclusion Totally laparoscopic bypass surgery is a feasible and safe procedure forAIOD,but attention needs to be paid to improve laparoscopic skills of vascular surgery in order to minimize morbidity during the learning

  1. Neuronal transport of acid hydrolases and peroxidase within the lysosomal system or organelles: involvement of agranular reticulum-like cisterns.

    Science.gov (United States)

    Broadwell, R D; Oliver, C; Brightman, M W

    1980-04-01

    Neurosecretory neurons of the hyperosmotically stressed hypothalamo-neurohypophysial system have been a useful model with which to demonstrate interrelationships among perikaryal lysosomes, agranular reticulum-like cisterns, endocytotic vacuoles, and the axoplasmic transport of acid hydrolases and horseradish peroxidase. Supraoptic neurons from normal mice and mice given 2% salt water to drink for 5--8 days have been studied using enzyme cytochemical techniques for peroxidase and lysosomal acid hydrolases. Peroxidase-labeling of these neurons was accomplished by intravenous injection or cerebral ventriculocisternal perfusion of the protein as previously reported (Broadwell and Brightman, '79). Compared to normal controls, supraoptic cell bodies from hyperosmotically stimulated mice contained elevated concentrations of peroxidase-labeled dense bodies demonstrated to be secondary lysosomes and acid hydrolase-positive and peroxidase-positive cisterns either attached or unattached to secondary lysosomes. These cisterns were smooth-surfaced and 400--1,000 A wide. Their morphology was similar to that of the agranular reticulum. Some of the cisterns contained both peroxidase and acid hydrolase activities. The cisterns probably represent an elongated form of lysosome and, therefore, are not elements of the agranular reticulum per se. By virtue of their direct connections with perikaryal secondary lysosomes, these cisterns may provide the route by which acid hydrolases and exogenous macromolecules can leave perikaryal secondary lysosomes for anterograde flow down the axon. Very few smooth-surfaced cisterns were involved in the retrograde transport of peroxidase within pituitary stalk axons from normal and salt-treated mice injected intravenously with peroxidase. Peroxidase undergoing retrograde transport was predominantly in endocytotic structures such as vacuoles and cup-shaped organelles, which deliver this exogenous macromolecule directly to secondary lysosomes for

  2. Lysosome-associated protein 1 (LAMP-1) and lysosome-associated protein 2 (LAMP-2) in a larger family carrier of Fabry disease.

    Science.gov (United States)

    Pereira, Ester M; do Monte, Semiramis J H; do Nascimento, Fernando F; de Castro, Jose A F; Sousa, Jackeline L M; Filho, Henrique C S A L C; da Silva, Raimundo N; Labilloy, Anatália; Monte Neto, José T; da Silva, Adalberto S

    2014-02-15

    This study investigated the potential relationship between the expression levels of lysosome-associated membrane proteins (LAMP) 1 and 2 and responses to enzyme replacement therapy (ERT) in the members of a single family with Fabry disease (FD). LAMP levels were assessed by flow cytometry in leukocytes from 17 FD patients who received an eight-month course of ERT course and 101 healthy individuals. We found that phagocytic cells from the FD patients had higher expression levels of both LAMP-1 and LAMP-2, relative to the levels in phagocytes from the healthy controls (p=0.001). Furthermore, the LAMP-1 and LAMP-2 levels in phagocytes from the FD carriers continuously decreased with ERT administration to reach levels similar to those in healthy controls. We suggest that LAMP-1 and LAMP-2 could be used as additional markers with which to assess ERT effectiveness in FD.

  3. Jugular-axillary vein bypass for salvage of arteriovenous access.

    Science.gov (United States)

    Fulks, K D; Hyde, G L

    1989-01-01

    Stenosis or occlusion of the subclavian vein can cause incapacitating upper extremity swelling and venous hypertension in the patient with an arteriovenous (AV) access. A case of subclavian vein occlusion is reported that was treated with internal jugular-axillary vein bypass. This procedure resulted in salvage of the access and rapid resolution of the associated upper extremity swelling. It was concluded that jugular-axillary vein bypass should be considered in patients who have massive upper extremity edema resulting from a functioning AV access and ipsilateral subclavian vein occlusion. Patients undergoing creation of an AV access who have had previous temporary subclavian catheters or previous early failure of an AV access should have phlebography before surgery.

  4. Arteriovenous fistulas aggravate the hemodynamic effect of vein bypass stenoses

    DEFF Research Database (Denmark)

    Nielsen, T G; Djurhuus, C; Pedersen, Erik Morre;

    1996-01-01

    PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced...... 10 cm upstream of a fistula with low outflow resistance. Flow and intraluminal pressure were measured proximal to the stenosis and downstream of the fistula. The waveform parameters peak systolic velocity, end-diastolic velocity, pulsatility index, and pulse rise time were determined from midstream...... Doppler spectra obtained 10 cm downstream of the fistula. All measurements were carried out with open and clamped fistula. RESULTS: At 30% diameter reducing stenosis opening of the fistula induced a 12% systolic pressure drop across the stenosis but had no adverse effect on the Doppler waveform parameters...

  5. Axillobifemoral bypass: a brief surgical and historical review

    Science.gov (United States)

    Mishall, Priti L.; Matakas, Jason D.; English, Keara; Allyn, Katherine; Algava, Diane; Howe, Ruth A.; Downie, Sherry A.

    2017-01-01

    Peripheral artery disease (PAD) occurs when plaque accumulates in the arterial system and obstructs blood flow. Narrowing of the abdominal aorta and the common iliac arteries due to atherosclerotic plaques restricts blood supply to the lower limbs. Clinically, the lower limb symptoms of PAD are intermittent claudication, discoloration of the toes, and skin ulcers, all due to arterial insufficiency. Surgical revascularization is the primary mode of treatment for patients with severe limb ischemia. The objective of the surgical procedure is to bypass a blockage in an occluded major vessel by constructing an alternate route for blood flow using an artificial graft. This article presents information on aortoiliac reconstruction, with an emphasis on axillobifemoral bypass grafting.

  6. Dobutamine for inotropic support during emergence from cardiopulmonary bypass.

    Science.gov (United States)

    Tinker, J H; Tarhan, S; White, R D; Pluth, J R; Barnhorst, D A

    1976-04-01

    Dobutamine, a recently introduced derivative of dopamine, is reported to retain inotropic properties with less pronounced chronotropic and arrhythmogenic effects than isoproterenol. The drug was evaluated in two doses, 5 mug/kg/min and 10 mug/kg/min, in two groups of ten patients each, during emergence from cardiopulmonary bypass. A third group of five patients was studied similarly with isoproterenol, 0.02 mug/kg/min. Cardiac index increased 16 and 28 per cent eith the two doses of dobutamine, respectively, and 9 per cent with isoproterenol. Heart rate, in contrast, increased 6 and 15 per cent with dobutamine (not significant) and 44 per cent with isoproterenol (significant). Dobutamine seemed to associated with fewer arrhythmias than isoproterenol. It is concluded that dobutamine, 5-10 mug/kg/min, is suitable for use during emergence from cardiopulmonary bypass and may possess advantages over isoproterenol.

  7. Coronary artery bypass grafting in a patient with organophosphate poisoning.

    Science.gov (United States)

    Pieris, Rajeeva R; Fernando, Ravindra

    2015-08-30

    A 43-year-old male, with no previous history of mental illness, was diagnosed with coronary heart disease, after which he became acutely depressed and attempted suicide by ingesting an organophosphate pesticide. He was admitted to an intensive care unit and treated with pralidoxime, atropine, and oxygen. His coronary occlusion pattern required early coronary artery bypass grafting (CABG) surgery. His family, apprehensive of a repeat suicidal attempt, requested surgery be performed as soon as possible. He recovered well from the OP poisoning and was mentally fit to express informed consent 2 weeks after admission. Seventeen days after poisoning, he underwent coronary artery bypass grafting and recovered uneventfully. Six years later, he remains in excellent health. We report this case because to the best of our knowledge there is no literature regarding CABG performed soon after organophosphate poisoning.

  8. In situ saphenous vein bypass surgery in diabetic patients

    DEFF Research Database (Denmark)

    Jensen, L P; Schroeder, T V; Lorentzen, J E

    1992-01-01

    .005). Indication for surgery was gangrene or ulceration in 57% of diabetics, as opposed to 36% in non-diabetic patients (p = 0.0002). A femoro-popliteal bypass was performed in 18% of patients, whereas 82% received an infrapopliteal procedure, of which 42% were to the distal third of the calf or foot. Diabetic......From 1986 through to 1990 a total of 483 consecutive in situ infra-inguinal vein bypass procedures were performed in 444 patients, of whom 112 (25%) were diabetics (57 insulin dependent diabetes mellitus and 55 non-insulin-dependent diabetes mellitus). Based on a prospective vascular data registry...... this material was analysed to determine the influence of diabetes on the outcome. Preoperative risk factors were equally distributed among diabetic and non-diabetic patients, except for smoking habits (diabetics: 48%; non-diabetics: 64%, p = 0.002) and cardiac disease (diabetics: 45%; non-diabetics: 29%, p = 0...

  9. Dacron or PTFE for above-knee femoropopliteal bypass

    DEFF Research Database (Denmark)

    Jensen, Leif P.; Lepäntalo, M.; Fossdal, J.E.

    2007-01-01

    OBJECTIVES: To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass. DESIGN: Multicenter randomised clinical trial. MATERIAL AND METHODS: 427 patients were randomised between 6mm Dacron (Uni-Graft, B. Braun Melsungen AG, 34212 Melsungen, Germany......) and PTFE (Goretex, W. L. Gore & Ass. Inc., Newark DE 19711, USA) above-knee femoropopliteal bypass grafts within 13 centres in Denmark (n=261), Norway (n=113) & Finland (n=53) between 1993 and 1998. Fourteen (3%) patients were excluded, leaving 413 patients with 208 Dacron and 205 PTFE grafts for analysis......-brachial pressures or imaging in case of doubt. RESULTS: The two-year primary patency rates for Dacron and PTFE were 70% and 57% (p=0.02), whereas the secondary patency rates were 76% and 65% (p=0.04), respectively. Primary patency at two years was significantly influenced by the number of patent crural vessels (two...

  10. ANALYSIS OF 312 CASES OF REPEAT CORONARY ARTERY BYPASS GRAFTING

    Institute of Scientific and Technical Information of China (English)

    陈长志; 陆佩中

    2003-01-01

    Objective To evaluate repeat coronary artery bypass grafting (CABG) in 312 patients.Methods The data of 312 patients (average age 65±9 years) who had CABG operation in Hartford hospital were collected and analyzed. The mean duration follow up after the first CABG was 11.8±4.5 years. A total of 1069 bypass grafts were performed. Among them, 386 were arterial grafts such as internal mammary artery, radial artery and gastroepiploic artery; 682 were venous grafts and 1 Gore-Tex graft. Results The operative mortality was 4. 5%. Fifteen patients (4. 8%) had peri-operative myocardial infarction and 46 patients (15%) had low cardiac output syndrome. Intra-aortic balloon pump (IABP) was used in 131 patients before, during and after operation. One hundred and nineteen patients weaned off IABP and recovered. ConclusionAlthough the difficulties and risk factors were increased, the results of redo CABG were still good.

  11. The impact of avoiding cardiopulmonary by-pass during coronary artery bypass surgery in elderly patients: the Danish On-pump Off-pump Randomisation Study (DOORS)

    DEFF Research Database (Denmark)

    Houlind, Kim; Kjeldsen, Bo Juul; Madsen, Susanne Nørgaard;

    2009-01-01

    BACKGROUND: Coronary Artery Bypass Graft operation for ischemic heart disease provides improved quality of life and, in some patients, prolonged survival. Concern has, however, been raised about complications that may be related to the use of cardiopulmonary by-pass (CPB) and aortic cross-clampin...

  12. secondary Prevention of Coronary Events by Coronary Artery Bypass Surgery

    OpenAIRE

    2003-01-01

    Coronary artery bypass surgery has shown its superiority on other therapeutic options in specific but frequent indications such as left main lesions, multivessel disease with alteration of ventricular function, proximal lesions of the LAD, and multivessel diseases in diabetic patients. After reviewing the epidemiology of coronary artherosclerosis, we emphasize the efficacy of the surgical treatment compared to medical or interventional therapy for preventing ischemic events. The results deriv...

  13. Human gut microbiota in obesity and after gastric bypass.

    Science.gov (United States)

    Zhang, Husen; DiBaise, John K; Zuccolo, Andrea; Kudrna, Dave; Braidotti, Michele; Yu, Yeisoo; Parameswaran, Prathap; Crowell, Michael D; Wing, Rod; Rittmann, Bruce E; Krajmalnik-Brown, Rosa

    2009-02-17

    Recent evidence suggests that the microbial community in the human intestine may play an important role in the pathogenesis of obesity. We examined 184,094 sequences of microbial 16S rRNA genes from PCR amplicons by using the 454 pyrosequencing technology to compare the microbial community structures of 9 individuals, 3 in each of the categories of normal weight, morbidly obese, and post-gastric-bypass surgery. Phylogenetic analysis demonstrated that although the Bacteria in the human intestinal community were highly diverse, they fell mainly into 6 bacterial divisions that had distinct differences in the 3 study groups. Specifically, Firmicutes were dominant in normal-weight and obese individuals but significantly decreased in post-gastric-bypass individuals, who had a proportional increase of Gammaproteobacteria. Numbers of the H(2)-producing Prevotellaceae were highly enriched in the obese individuals. Unlike the highly diverse Bacteria, the Archaea comprised mainly members of the order Methanobacteriales, which are H(2)-oxidizing methanogens. Using real-time PCR, we detected significantly higher numbers of H(2)-utilizing methanogenic Archaea in obese individuals than in normal-weight or post-gastric-bypass individuals. The coexistence of H(2)-producing bacteria with relatively high numbers of H(2)-utilizing methanogenic Archaea in the gastrointestinal tract of obese individuals leads to the hypothesis that interspecies H(2) transfer between bacterial and archaeal species is an important mechanism for increasing energy uptake by the human large intestine in obese persons. The large bacterial population shift seen in the post-gastric-bypass individuals may reflect the double impact of the gut alteration caused by the surgical procedure and the consequent changes in food ingestion and digestion.

  14. Interventions in infrainguinal bypass grafts; Interventionen an infrainguinalen Bypaessen

    Energy Technology Data Exchange (ETDEWEB)

    Schoder, M.; Cejna, M.; Lammer, J. [Univ. Klinik fuer Radiodiagnostik, Wien (Austria). Abt. fuer Angiographie und Interventionelle Radiologie

    2001-12-01

    The long-term success of infrainguinal bypass grafts depends on meticulous surgical technique and a periodic program of postoperative surveillance. Duplex scanning is the method of choice for the detection of stenotic lesions that threaten graft patency. As an alternative to surgery, PTA is gaining increasing acceptance for the treatment of non-recurrent, short, and single stenotic lesions, despite somewhat controversial opinions. The initial technical success rates for PTA were reported to be up to 100%, and a 5-year primary assisted patency rate of up to 65% has been achieved. Some authors favorize intra-arterial infusion of fibrinolytic agents for the treatment of bypass graft occlusion with technical success rates of up to 92%. In addition to a reduced trauma compared to surgical thrombectomy, of the venous wall the advantage of thrombolytic therapy is clot lysis in run-off vessels, and uncovering of the stenotic lesions. This stenosis may then be treated by an endovascular or surgical approach. (orig.) [German] Der Langzeiterfolg infrainguinaler Bypaesse wird vor allem durch Anastomosenstenosen, seltener durch Stenosen im Bypass selbst, bestimmt. Neben exakten Operationstechniken ist deshalb eine regelmaessige postoperative Ueberwachung des Bypasses zur Verbesserung der Langzeitdurchgaengigkeit allgemein akzeptiert. Zur Identifizierung von bypassgefaehrdenden Stenosen hat die Duplexsonographie als Untersuchungsmodalitaet der Wahl einen fixen Stellenwert erlangt. Die perkutane transluminale Angioplastie (PTA) ist eine sinnvolle, minimal invasive Alternative zur offenen chirurgischen Revision von erstmalig aufgetretenen kurzstreckigen und singulaeren Bypassstenosen respektive Anastomosenstenosen. Primaer technische Erfolgsraten nach PTA werden bis zu 100%, primaer assistierte 5-Jahres-Offenheitsraten bis zu 65% angegeben. Die intraarterielle Thrombolyse bei Bypassthrombosen ist mit bis zu 92%iger technischer Erfolgsrate von manchen Arbeitsgruppen als primaere

  15. Assessing Patient bypass Behavior Using Taxi Trip Origin–Destination (OD Data

    Directory of Open Access Journals (Sweden)

    Gege Yang

    2016-09-01

    Full Text Available Many patients prefer to use the best hospitals even if there are one or more other hospitals closer to their homes; this behavior is called “hospital bypass behavior”. Because this behavior can be problematic in urban areas, it is important that it be reduced. In this paper, the taxi GPS data of Beijing and Suzhou were used to measure hospital bypass behavior. The “bypass behavior index” (BBI represents the bypass behavior for each hospital. The results indicated that the mean hospital bypass trip distance value ranges from 5.988 km to 9.754 km in Beijing and from 4.168 km to 10.283 km in Suzhou. In general, the bypass shares of both areas show a gradually increasing trend. The following hospitals exhibited significant patient bypass behavior: the 301 Hospital, Beijing Children’s Hospital, the Second Affiliated Hospital of Soochow University and the Suzhou Hospital of Traditional Chinese Medicine. The hospitals’ reputation, transport accessibility and spatial distribution were found to be the main factors affecting patient bypass behavior. Although the hospital bypass phenomena generally appeared to be more pronounced in Beijing, the bypass trip distances between hospitals were found to be more significant in Suzhou.

  16. Chronic high glucose inhibits albumin reabsorption by lysosomal alkalinization in cultured porcine proximal tubular epithelial cells (LLC-PK1).

    Science.gov (United States)

    Ishibashi, Fukashi

    2006-06-01

    Lysosomal acidification is a key step of albumin reabsorption in proximal tubular epithelial cells (PTECs). This study was performed to examine the influence of chronic high glucose on lysosomal acidification in cultured PTECs. Porcine PTECs (LLC-PK(1) cells) were cultured in 16.7 mM (300 mg/dl) glucose (HG) alone or with 0.5 mM phlorizin for 24 weeks and subsequently for 12 weeks in 5.5 mM (100 mg/dl) glucose (NG). Chronic HG inhibited the fluorescein isothiocyanate (FITC)-albumin (A) uptake progressively, while phlorizin reversed the inhibition. NG for 12 weeks after HG normalized the uptake. The time-dependent uptake of FITC-A was inhibited by HG and bafilomycin A(1) (BafA(1)) after 15 min and by 4,4'-diisothiocyanato-2,2'-disulfonic acid (DIDS) and N-ethyl-N-isopropyl-amiloride (EIPA) after 3 min. Cellular ATP was depleted by HG and restored by NG. Lysosomal pH, assessed by an acidotropic fluorescent probe, was alkalinized (pH 4.5-7.8) with 5.5-27.8 mM glucose and normalized by subsequent NG. BafA(1) alkalinized lysosomes, and the concentration required to 50% change for the pH and 50% inhibition of FITC-A uptake was similar. EIPA inhibited FITC-A uptake, but did not influence lysosomal pH. DIDS inhibited FITC-A uptake, and unexpectedly lowered lysosomal pH. Real time PCR showed that HG reduced the mRNA level for vacuolar H(+)-ATPase, but did not alter those of chloride channel-5 and Na(+)-H(+)-exchanger-3. In conclusion, the chronic HG inhibits albumin reabsorption by lysosomal alkalinization in PTECs, probably due to ATP depletion and down-regulation of vacuolar H(+)-ATPase.

  17. Ceria nanoparticles stabilized by organic surface coatings activate the lysosome-autophagy system and enhance autophagic clearance.

    Science.gov (United States)

    Song, Wensi; Soo Lee, Seung; Savini, Marzia; Popp, Lauren; Colvin, Vicki L; Segatori, Laura

    2014-10-28

    Cerium oxide nanoparticles (nanoceria) are widely used in a variety of industrial applications including UV filters and catalysts. The expanding commercial scale production and use of ceria nanoparticles have inevitably increased the risk of release of nanoceria into the environment as well as the risk of human exposure. The use of nanoceria in biomedical applications is also being currently investigated because of its recently characterized antioxidative properties. In this study, we investigated the impact of ceria nanoparticles on the lysosome-autophagy system, the main catabolic pathway that is activated in mammalian cells upon internalization of exogenous material. We tested a battery of ceria nanoparticles functionalized with different types of biocompatible coatings (N-acetylglucosamine, polyethylene glycol and polyvinylpyrrolidone) expected to have minimal effect on lysosomal integrity and function. We found that ceria nanoparticles promote activation of the transcription factor EB, a master regulator of lysosomal function and autophagy, and induce upregulation of genes of the lysosome-autophagy system. We further show that the array of differently functionalized ceria nanoparticles tested in this study enhance autophagic clearance of proteolipid aggregates that accumulate as a result of inefficient function of the lysosome-autophagy system. This study provides a mechanistic understanding of the interaction of ceria nanoparticles with the lysosome-autophagy system and demonstrates that ceria nanoparticles are activators of autophagy and promote clearance of autophagic cargo. These results provide insights for the use of nanoceria in biomedical applications, including drug delivery. These findings will also inform the design of engineered nanoparticles with safe and precisely controlled impact on the environment and the design of nanotherapeutics for the treatment of diseases with defective autophagic function and accumulation of lysosomal storage material.

  18. Turning the gun on cancer: Utilizing lysosomal P-glycoprotein as a new strategy to overcome multi-drug resistance.

    Science.gov (United States)

    Seebacher, Nicole; Lane, Darius J R; Richardson, Des R; Jansson, Patric J

    2016-07-01

    Oxidative stress plays a role in the development of drug resistance in cancer cells. Cancer cells must constantly and rapidly adapt to changes in the tumor microenvironment, due to alterations in the availability of nutrients, such as glucose, oxygen and key transition metals (e.g., iron and copper). This nutrient flux is typically a consequence of rapid growth, poor vascularization and necrosis. It has been demonstrated that stress factors, such as hypoxia and glucose deprivation up-regulate master transcription factors, namely hypoxia inducible factor-1α (HIF-1α), which transcriptionally regulate the multi-drug resistance (MDR), transmembrane drug efflux transporter, P-glycoprotein (Pgp). Interestingly, in addition to the established role of plasma membrane Pgp in MDR, a new paradigm of intracellular resistance has emerged that is premised on the ability of lysosomal Pgp to transport cytotoxic agents into this organelle. This mechanism is enabled by the topological inversion of Pgp via endocytosis resulting in the transporter actively pumping agents into the lysosome. In this way, classical Pgp substrates, such as doxorubicin (DOX), can be actively transported into this organelle. Within the lysosome, DOX becomes protonated upon acidification of the lysosomal lumen, causing its accumulation. This mechanism efficiently traps DOX, preventing its cytotoxic interaction with nuclear DNA. This review discusses these effects and highlights a novel mechanism by which redox-active and protonatable Pgp substrates can utilize lysosomal Pgp to gain access to this compartment, resulting in catastrophic lysosomal membrane permeabilization and cell death. Hence, a key MDR mechanism that utilizes Pgp (the "gun") to sequester protonatable drug substrates safely within lysosomes can be "turned on" MDR cancer cells to destroy them from within.

  19. Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury.

    Science.gov (United States)

    Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

    2015-01-01

    Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury.

  20. Distal wound complications following pedal bypass: analysis of risk factors.

    Science.gov (United States)

    Robison, J G; Ross, J P; Brothers, T E; Elliott, B M

    1995-01-01

    Wound complications of the pedal incision continue to compromise successful limb salvage following aggressive revascularization. Significant distal wound disruption occurred in 14 of 142 (9.8%) patients undergoing pedal bypass with autogenous vein for limb salvage between 1986 and 1993. One hundred forty-two pedal bypass procedures were performed for rest pain in 66 patients and tissue necrosis in 76. Among the 86 men and 56 women, 76% were diabetic and 73% were black. All but eight patients had a history of diabetes and/or tobacco use. Eight wounds were successfully managed with maintenance of patent grafts from 5 to 57 months. Exposure of a patent graft precipitated amputation in three patients, as did graft occlusion in an additional patient. One graft was salvaged by revision to the peroneal artery and one was covered by a local bipedicled flap. Multiple regression analysis identified three factors associated with wound complications at the pedal incision site: diabetes mellitus (p = 0.03), age > 70 years (p = 0.03), and rest pain (p = 0.05). Ancillary techniques ("pie-crusting") to reduce skin tension resulted in no distal wound problems among 15 patients considered to be at greatest risk for wound breakdown. Attention to technique of distal graft tunneling, a wound closure that reduces tension, and control of swelling by avoiding dependency on and use of gentle elastic compression assume crucial importance in minimizing pedal wound complications following pedal bypass.

  1. Percutaneous mechanical thrombectomy for treatment of acute femoropopliteal bypass occlusion

    Directory of Open Access Journals (Sweden)

    Lichtenberg M

    2012-05-01

    Full Text Available Michael Lichtenberg1, Matthias Käunicke1, Birgit Hailer1,21Cardiovascular Clinic, Vascular Center, Katholisches Klinikum Essen, Germany; 2University of Witten/Herdecke, GermanyAbstract: Acute and subacute ischemia of the legs in acute and subacute femoropopliteal bypass occlusion is a dramatic situation that endangers the survival of the limbs, depending on the severity of the ischemia. Different therapy options like percutaneous mechanical thrombectomy procedures, which include rotational thrombectomy, have become available in recent years, in addition to local lysis and surgical thrombectomy. Surgical thrombectomy using the Fogarty catheter technique, in particular, shows an increased incidence of perioperative complications but only small technical success rates in randomized trials. On the other hand, local lysis is associated with increased costs due to resource-consuming measures, such as intensive monitoring and repeat angiographies, in addition to bleeding complications. In the past, further development of the Straub Rotarex® system as an endovascular therapy option has demonstrated good success leading to amputation-free survival in multiple studies. At the same time, a low rate of complications with use has been documented. Most examinations have been conducted in the thigh. To date, there are little investigational data on its use in acutely and subacutely occluded femoropopliteal bypasses. In this paper, the current study-based significance of the Rotarex system for this indication is analyzed based on the existing literature and the authors' own experiences with 22 patients.Keywords: acute limb ischemia, femoropopliteal bypass, local lysis, rotational thrombectomy

  2. Pipelining and bypassing in a RISC/DSP processor

    Science.gov (United States)

    Yu, Guojun; Yao, Qingdong; Liu, Peng; Jiang, Zhidi; Li, Fuping

    2005-03-01

    This paper proposes pipelining and bypassing unit (BPU) design method in our 32-bit RISC/DSP processor: MediaDsp3201 (briefly, MD32). MD32 is realized in 0.18μm technology, 1.8v, 200MHz working clock and can achieve 200 million/s Multiply-Accumulate (MAC) operations. It merges RISC architecture and DSP computation capability thoroughly, achieves fundamental RISC, extended DSP and single instruction multiple data (SIMD) instruction set with various addressing modes in a unified and customized DSP pipeline stage architecture. We will first describe the pipeline structure of MD32, comparing it to typical RISC-style pipeline structure. And then we will study the validity of two bypassing schemes in terms of their effectiveness in resolving pipeline data hazards: Centralized and Distributed BPU design strategy (CBPU and DBPU). A bypassing circuit chain model is given for DBPU, which register read is only placed at ID pipe stage. Considering the processor"s working clock which is decided by the pipeline time delay, the optimization of circuit that serial select with priority is also analyzed in detail since the BPU consists of a long serial path for combination logic. Finally, the performance improvement is analyzed.

  3. Ileal loop interposition:an alternative biliar y bypass technique

    Institute of Scientific and Technical Information of China (English)

    Felipe JF Coimbra; Alessandro L Diniz; Heber SC Ribeiro; Wilson L Costa Jr.; Eduardo NP Lima; André L Montagnini

    2010-01-01

    BACKGROUND: Obstructive jaundice is a common condition in advanced digestive cancer. Palliative procedures can improve quality of life and allow patients to attempt a systemic treatment. Bilioenteric anastomosis is still the procedure of choice for patients in many centers. When a surgical bypass is not possible, biliary drainage can be done by placing endoscopic or transparietal stents, which are less durable methods even when an expandable stent is employed. METHODS: A 47-year-old male with an excellent clinical status and a previous cholecystectomy and an exploratory laparotomy for advanced gastric cancer was referred with obstructive jaundice. A preoperative CT scan showed a dilated bile duct and a small mass at the distal hepatic hilum. No other signs of metastasis were found. A surgical bilioenteric anastomosis was indicated. At surgery, a distal choledochal obstruction and a mesenteric retraction by a lymph node mass prevented the jejunum to ascend for a bilioenteric anastomosis. Surgically, an alternative bilioenteric bypass was performed by means of an ileal loop interposition between the bile duct and the jejunum. RESULT: The recovery of the patient was uneventful and his bilirubin levels normalized after one week. The patient was then referred for systemic chemotherapy. CONCLUSIONS: This alternative biliary bypass can be safely and easily performed, and may be a good alternative for patients already referred for surgery because of a better life expectancy and when the jejunum is not an alternative.

  4. Breast cancer biomarkers predict weight loss after gastric bypass surgery

    Directory of Open Access Journals (Sweden)

    Sauter Edward R

    2012-01-01

    Full Text Available Abstract Background Obesity has long been associated with postmenopausal breast cancer risk and more recently with premenopausal breast cancer risk. We previously observed that nipple aspirate fluid (n levels of prostate specific antigen (PSA were associated with obesity. Serum (s levels of adiponectin are lower in women with higher body mass index (BMI and with breast cancer. We conducted a prospective study of obese women who underwent gastric bypass surgery to determine: 1 change in n- and s-adiponectin and nPSA after surgery and 2 if biomarker change is related to change in BMI. Samples (30-s, 28-n and BMI were obtained from women 0, 3, 6 and 12 months after surgery. Findings There was a significant increase after surgery in pre- but not postmenopausal women at all time points in s-adiponectin and at 3 and 6 months in n-adiponectin. Low n-PSA and high s-adiponectin values were highly correlated with decrease in BMI from baseline. Conclusions Adiponectin increases locally in the breast and systemically in premenopausal women after gastric bypass. s-adiponectin in pre- and nPSA in postmenopausal women correlated with greater weight loss. This study provides preliminary evidence for biologic markers to predict weight loss after gastric bypass surgery.

  5. EARLY POSTOPERATIVE COMPLICATIONS IN ROUX-EN-Y GASTRIC BYPASS

    Science.gov (United States)

    STOLL, Aluisio; ROSIN, Leandro; DIAS, Mariana Fernandes; MARQUIOTTI, Bruna; GUGELMIN, Giovana; STOLL, Gabriela Fanezzi

    2016-01-01

    ABSTRACT Background: Roux-en-Y gastric bypass is one of the most common bariatric surgery and leads to considerable weight loss in the first months. Aim: To quantify the main early postoperative complications in patients submitted to the gastric bypass. Method: Observational retrospective cohort. Data of 1051 patients with class II obesity associated with comorbidities or class III obesity submitted to the gastric bypass with 30 days of follow-up starting from the date of the surgery. Results: The age average was 36 years with a predominance of females (81.1%). The mean preoperative body mass index was 43 kg/m². The major complication was fistula (2.3%), followed by intestinal obstruction (0.5%) and pulmonary embolism (0.5%). Death occurred in 0.6% of the cases. Conclusion: In the period of 30 days after surgery the overall complication rate was 3.8%; reoperation was necessary in 2.6% and death occurred in 0.6%. Fistula was the main complication and the leading cause of hospitalization in intensive care unit, reoperation and death. PMID:27683781

  6. COMPLICATIONS RELATED TO GASTRIC BYPASS PERFORMED WITH DIFFERENT GASTROJEJUNAL DIAMETERS

    Science.gov (United States)

    SAMPAIO-NETO, José; BRANCO-FILHO, Alcides José; NASSIF, Luis Sérgio; BROSKA, Anne Caroline; KAMEI, Douglas Jun; NASSIF, André Thá

    2016-01-01

    ABSTRACT Background: Among the options for surgical treatment of obesity, the most widely used has been the Roux-en-Y gastric bypass. The gastrojejunal anastomosis can be accomplished in two ways: handsewn or using circular and linear stapled. The complications can be divided in early and late. Aim: To compare the incidence of early complications related with the handsewn gastrojejunal anastomosis in gastric bypass using Fouchet catheter with different diameters. Method: The records of 732 consecutive patients who had undergone the bypass were retrospectively analyzed and divided in two groups, group 1 with 12 mm anastomosis (n=374), and group 2 with 15 mm (n=358). Results: The groups showed anastomotic stenosis with rates of 11% and 3.1% respectively, with p=0.05. Other variables related to the anastomosis were also analyzed, but without statistical significance (p>0.05). Conclusion: The diameter of the anastomosis of 15 mm was related with lower incidence of stenosis. It was found that these patients had major bleeding postoperatively and lower surgical site infection, and in none was observed presence of anastomotic leak. PMID:27683767

  7. Effects of ammonia on processing and secretion of precursor and mature lysosomal enzyme from macrophages of normal and pale ear mice: evidence for two distinct pathways

    OpenAIRE

    1985-01-01

    Lysosomal enzymes have been shown to be synthesized as microsomal precursors, which are processed to mature enzymes located in lysosomes. We examined the effect of ammonium chloride on the intracellular processing and secretion of two lysosomal enzymes, beta-glucuronidase and beta-galactosidase, in mouse macrophages. This lysosomotropic drug caused extensive secretion of both precursor and mature enzyme forms within a few hours, as documented by pulse radiolabeling and molecular weight analys...

  8. SUrgical versus PERcutaneous Bypass: SUPERB-trial; Heparin-bonded endoluminal versus surgical femoro-popliteal bypass: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Wallis de Vries Bas M

    2011-07-01

    Full Text Available Abstract Background Endovascular treatment options for the superficial femoral artery are evolving rapidly. For long lesions, the venous femoropopliteal bypass considered to be superior above the prosthetic bypass. An endoluminal bypass, however, may provide equal patency rates compared to the prosthetic above knee bypass. The introduction of heparin-bonded endografts may further improve patency rates. The SUrgical versus PERcutaneous Bypass (SuperB study is designed to assess whether a heparin-bonded endoluminal bypass provides equal patency rates compared to the venous bypass and to prove that it is associated with improved quality of life, related to a decreased complication rate, or not. Methods/design Two-hundred-twenty-two patients with peripheral arterial occlusive disease, category 3-6 according to Rutherford, will be randomized in two treatment arms; 1. the surgical femoro-popliteal bypass, venous whenever possible, and 2. the heparin-bonded endoluminal bypass. The power analysis was based on a non-inferiority principle, with an effect size of 90% and 10% margins (alpha 5%, power 80%. Patients will be recruited from 5 teaching hospitals in the Netherlands during a 2-year period. The primary endpoint is primary patency and quality of life evaluated by the RAND-36 questionnaire and the Walking Impairment Questionnaire. Secondary endpoints include secondary patency, freedom-from-TLR and complications. Discussion The SuperB trial is a multicentre randomized controlled trial designed to show non-inferiority in patency rates of the heparin-bonded endograft compared to the surgical bypass for treatment of long SFA lesions, and to prove a better quality of life using the heparin bonded-endograft compared to surgically treatment, related to a reduction in complications. Trial Registration Clinicaltrials: NCT01220245

  9. Laparoscopic gastric bypass to robotic gastric bypass: time and cost commitment involved in training and transitioning an academic surgical practice.

    Science.gov (United States)

    Lyn-Sue, Jerome R; Winder, Josh S; Kotch, Shannon; Colello, Jacob; Docimo, Salvatore

    2016-06-01

    The Roux-en-Y gastric bypass is the gold standard procedure for weight loss. This relatively complex procedure has excellent outcomes when performed via laparoscopy. The advent of the DaVinci robotic platform has been a technological advancement. Our goal is to provide information regarding the cost, time commitment, and advantages of transitioning an LRYGB program to an RRYGB program in an academic setting. We retrospectively reviewed the last 25 laparoscopic gastric bypass procedures and the first 25 robotic gastric bypass procedures performed by a single surgeon. We compared clinical outcomes and focused on time and hospital cost during this transition phase. There was no significant demographic difference between the groups. The mean age was 41.7 (RRYGB) years vs 43.4 (LRYGM) years. The mean BMI were similar between groups, 45.3 vs 46.5 kg/m(2) for RRYGB and LRYGB. No anastomotic leaks or mortalities were noted. There was one anastomotic stricture in both groups. Excess weight loss was similar in both groups at 1 year. There was a significant increase in operative time with RRYGB, mean 241 min vs mean 174 min (p = 0.0005). Operative time fell by 25 min after the first 10 cases. The hospital cost was also increased with RRYGB mean $5922 vs $4395 (p = 0.03). Transitioning from a laparoscopic to a robotic practice can be done safely, however, the initial operative times were longer and the hospital cost was higher for robotic gastric bypass. We hope in the future that these will decrease after overcoming the learning and as the technology becomes widespread.

  10. [Results of using composite bypass grafts with infragenicular distal anastomosis].

    Science.gov (United States)

    Pokrovskiĭ, A V; Iakhontov, D I

    2014-01-01

    The authors share herein their experience with composite bypass grafts and PTFE synthetic prostheses used for treatment of obliterating diseases of the infrainguinal-segment arteries. The data of the study were based on the outcomes obtained in 92 patients. The authors assessed the condition of the outflow pathways and their effect on patency of composite bypass grafts in the immediate and remote postoperative periods, followed by comparative analysis of the short- and long-term therapeutic outcomes after using composite bypass grafts and PTFE synthetic prostheses in the infragenicular position for femoropopliteal and femorotibial reconstructions, also assessing the effect of the localization of the distal anastomosis on the immediate and remote therapeutic outcomes. Based on the obtained findings it was determined that the immediate results of patency depended upon the state of the outflow pathways and localization of the distal anastomosis. Thus, by the 1st, 3rd and 5th year of follow up patency of transplants in patients with the runoff score less than 7.0 amounted to 78.3, 21.7 and 4.3%, respectively. Analogous indices of patency in patients with the runoff score equalling or greater than 7.0 amounted to 60.7 and 3.6% for the 1st and 3rd year, respectively. The remote results of patency turned out to depend on the type of a vascular transplant and the state of the outflow pathways and did not depend on the localization of the distal anastomosis. Thus, the remote results of patency for the composite bypass graft for the 1st, 3rd and 5th year of follow up amounted to 74.5, 19.6 and 5.9%, respectively, versus 60.8 and 8.6% by the first and third year for the PTFE prosthesis. The limb salvage rate at the same terms for the composite bypass graft amounted to 94.1, 84.3 and 78.4% versus 73.9, 56.5 and 52.2% for the PTFE prosthesis.

  11. Triazoles inhibit cholesterol export from lysosomes by binding to NPC1.

    Science.gov (United States)

    Trinh, Michael N; Lu, Feiran; Li, Xiaochun; Das, Akash; Liang, Qiren; De Brabander, Jef K; Brown, Michael S; Goldstein, Joseph L

    2017-01-03

    Niemann-Pick C1 (NPC1), a membrane protein of lysosomes, is required for the export of cholesterol derived from receptor-mediated endocytosis of LDL. Lysosomal cholesterol export is reportedly inhibited by itraconazole, a triazole that is used as an antifungal drug [Xu et al. (2010) Proc Natl Acad Sci USA 107:4764-4769]. Here we show that posaconazole, another triazole, also blocks cholesterol export from lysosomes. We prepared P-X, a photoactivatable cross-linking derivative of posaconazole. P-X cross-linked to NPC1 when added to intact cells. Cross-linking was inhibited by itraconazole but not by ketoconazole, an imidazole that does not block cholesterol export. Cross-linking of P-X was also blocked by U18666A, a compound that has been shown to bind to NPC1 and inhibit cholesterol export. P-X also cross-linked to purified NPC1 that was incorporated into lipid bilayer nanodiscs. In this in vitro system, cross-linking of P-X was inhibited by itraconazole, but not by U18666A. P-X cross-linking was not prevented by deletion of the N-terminal domain of NPC1, which contains the initial binding site for cholesterol. In contrast, P-X cross-linking was reduced when NPC1 contained a point mutation (P691S) in its putative sterol-sensing domain. We hypothesize that the sterol-sensing domain has a binding site that can accommodate structurally different ligands.

  12. Sulindac metabolites induce proteosomal and lysosomal degradation of the epidermal growth factor receptor.

    Science.gov (United States)

    Pangburn, Heather A; Ahnen, Dennis J; Rice, Pamela L

    2010-04-01

    The epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases. In response to ligand, EGFR is internalized and degraded by the ubiquitin-proteasome/lysosome pathway. We previously reported that metabolites of the nonsteroidal anti-inflammatory drug sulindac downregulate the expression of EGFR and inhibit basal and EGF-induced EGFR signaling through extracellular signal-regulated kinase 1/2. We now have evaluated the mechanisms of sulindac metabolite-induced downregulation of EGFR. EGF-induced downregulation of EGFR occurs within 10 minutes and lasts for 24 hours. By contrast, downregulation of EGFR by sulindac sulfide and sulindac sulfone was first evident at 4 and 24 hours, respectively, with maximal downregulation at 72 hours. Pretreatment with either the lysosomal inhibitor chloroquine or the proteosomal inhibitor MG132 blocked sulindac metabolite-induced downregulation of EGFR. Sulindac metabolites also increased the ubiquitination of EGFR. Whereas sulindac metabolites inhibited phosphorylation of EGFR pY1068, they increased phosphorylation of EGFR pY1045, the docking site where c-Cbl binds, thereby enabling receptor ubiquitination and degradation. Immunofluorescence analysis of EGF and EGFR distribution confirmed the biochemical observations that sulindac metabolites alter EGFR localization and EGFR internalization in a manner similar to that seen with EGF treatment. Expression of ErbB family members HER2 and HER3 was also downregulated by sulindac metabolites. We conclude that downregulation of EGFR expression by sulindac metabolites is mediated via lysosomal and proteosomal degradation that may be due to drug-induced phosphorylation at pY1045 with resultant ubiquitination of EGFR. Thus, sulindac metabolite-induced downregulation of EGFR seems to be mediated through mechanism(s) similar, at least in part, to those involved in EGF-induced downregulation of EGFR.

  13. Passage of downstream migrant American eels through an airlift-assisted deep bypass

    Science.gov (United States)

    Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

    2016-01-01

    Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

  14. Thrombin-induced lysosomal exocytosis in human platelets is dependent on secondary activation by ADP and regulated by endothelial-derived substances.

    Science.gov (United States)

    Södergren, Anna L; Svensson Holm, Ann-Charlotte B; Ramström, Sofia; Lindström, Eva G; Grenegård, Magnus; Öllinger, Karin

    2016-01-01

    Exocytosis of lysosomal contents from platelets has been speculated to participate in clearance of thrombi and vessel wall remodelling. The mechanisms that regulate lysosomal exocytosis in platelets are, however, still unclear. The aim of this study was to identify the pathways underlying platelet lysosomal secretion and elucidate how this process is controlled by platelet inhibitors. We found that high concentrations of thrombin induced partial lysosomal exocytosis as assessed by analysis of the activity of released N-acetyl-β-glucosaminidase (NAG) and by identifying the fraction of platelets exposing the lysosomal-associated membrane protein (LAMP)-1 on the cell surface by flow cytometry. Stimulation of thrombin receptors PAR1 or PAR4 with specific peptides was equally effective in inducing LAMP-1 surface expression. Notably, lysosomal exocytosis in response to thrombin was significantly reduced if the secondary activation by ADP was inhibited by the P2Y12 antagonist cangrelor, while inhibition of thromboxane A2 formation by treatment with acetylsalicylic acid was of minor importance in this regard. Moreover, the NO-releasing drug S-nitroso-N-acetyl penicillamine (SNAP) or the cyclic AMP-elevating eicosanoid prostaglandin I2 (PGI2) significantly suppressed lysosomal exocytosis. We conclude that platelet inhibitors that mimic functional endothelium such as PGI2 or NO efficiently counteract lysosomal exocytosis. Furthermore, we suggest that secondary release of ADP and concomitant signaling via PAR1/4- and P2Y12 receptors is important for efficient platelet lysosomal exocytosis by thrombin.

  15. The serotonin transporter undergoes constitutive internalization and is primarily sorted to late endosomes and lysosomal degradation

    DEFF Research Database (Denmark)

    Rahbek-Clemmensen, Troels; Bay, Tina; Eriksen, Jacob

    2014-01-01

    The serotonin transporter (SERT) plays a critical role in regulating serotonin signaling by mediating reuptake of serotonin from the extracellular space. The molecular and cellular mechanisms controlling SERT levels in the membrane remain poorly understood. To study trafficking of surface resident....... Furthermore, internalized SERT co-localized with the lysosomal marker LysoTracker and not with transferrin. The sorting pattern was further confirmed by visualizing internalization of SERT using the fluorescent cocaine analogue JHC1-64, and by reversible and pulse chase biotinylation assays showing evidence...

  16. Involvement of the endosomal-lysosomal system correlates with regional pathology in Creutzfeldt-Jakob disease

    DEFF Research Database (Denmark)

    Kovács, Gábor G; Gelpi, Ellen; Ströbel, Thomas;

    2007-01-01

    these with the severity of neuropathologic changes. In regions with mild pathology and scant abnormal prion protein (PrP) deposition, neurons showed an increased volume of Rab5-immunopositive early endosomes. In contrast, neurons in regions with prominent pathology had an increased volume of cathepsin D- or B......-immunoreactive lysosomes. The intraneuronal distribution of cathepsin D and B diverges between Purkinje cells and frontal cortical neurons in sporadic Creutzfeldt-Jakob disease brains. We demonstrated focal intra- and perineuronal colocalization of cathepsin D and PrP. Our results indicate that effects in the ELS...

  17. Radiation-induced alterations in the distribution of lysosomal hydrolases in rat spleen homogenates. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S.L.; Eklund, S.K.

    1978-07-01

    Whole-body exposure of rats to /sup 60/Co-..gamma.. radiation results in increases in the activities of two lysosomal hydrolases, ..beta..-glucuronidase and ..cap alpha..-fucosidase, found in the supernatant fraction of spleen homogenates. The redistribution of these enzymes from the ''particulate-bound'' to the ''free-supernatant'' fraction of spleen homogenates has been studied as a function of radiation dose. The response curves for the ratio of free/bound enzyme versus dose sigmoidal with maximum occurring at 300 to 400 rad.

  18. Lysosomal Fusion Dysfunction as a Unifying Hypothesis for Alzheimer's Disease Pathology

    Directory of Open Access Journals (Sweden)

    Kristen E. Funk

    2012-01-01

    Full Text Available Alzheimer's disease is characterized pathologically by extracellular senile plaques, intracellular neurofibrillary tangles, and granulovacuolar degeneration. It has been debated whether these hallmark lesions are markers or mediators of disease progression, and numerous paradigms have been proposed to explain the appearance of each lesion individually. However, the unfaltering predictability of these lesions suggests a single pathological nidus central to disease onset and progression. One of the earliest pathologies observed in Alzheimer's disease is endocytic dysfunction. Here we review the recent literature of endocytic dysfunction with particular focus on disrupted lysosomal fusion and propose it as a unifying hypothesis for the three most-studied lesions of Alzheimer's disease.

  19. The spreading process of Ehrlichia canis in macrophages is dependent on actin cytoskeleton, calcium and iron influx and lysosomal evasion.

    Science.gov (United States)

    Alves, R N; Levenhagen, M A; Levenhagen, M M M D; Rieck, S E; Labruna, M B; Beletti, M E

    2014-01-31

    Ehrlichia canis is an obligate intracellular microorganism and the etiologic agent of canine monocytic ehrlichiosis. The invasion process has already been described for some bacteria in this genus, such as E. muris and E. chaffeensis, and consists of four stages: adhesion, internalisation, intracellular proliferation and intercellular spreading. However, little is known about the spreading process of E. canis. The aim of this study was to analyse the role of the actin cytoskeleton, calcium, iron and lysosomes from the host cell in the spreading of E. canis in dog macrophages in vitro. Different inhibitory drugs were used: cytochalasin D (actin polymerisation inhibitor), verapamil (calcium channel blocker) and deferoxamine (iron chelator). Our results showed a decrease in the number of bacteria in infected cells treated with all drugs when compared to controls. Lysosomes in infected cells were cytochemically labelled with acid phosphatase to allow the visualisation of phagosome-lysosome fusion and were further analysed by transmission electron microscopy. Phagosome-lysosome fusion was rarely observed in vacuoles containing viable E. canis. These data suggest that the spreading process of E. canis in vitro is dependent on cellular components analysed and lysosomal evasion.

  20. Effects of contaminant exposure and food restriction on hepatic autophagic lysosomal parameters in Herring Gull (Larus argentatus) chicks.

    Science.gov (United States)

    Hegseth, Marit Nøst; Gorbi, Stephania; Bocchetti, Raffaella; Camus, Lionel; Gabrielsen, Geir Wing; Regoli, Francesco

    2014-08-01

    Lysosomal autophagic responses, such as lysosomal membrane stability, neutral lipids (NL), lipofuscin (LF), and malondialdehyde (MDA) levels, are valuable measures of cellular early-onset effects induced by environmental stress factors, such as contaminant exposure and fasting. In this study, these parameters were analysed and related to levels of halogenated organic contaminants (HOCs) in 40 Herring Gull (Larus argentatus) chicks. Chicks were experimentally exposed to HOCs through diet and went through a period of nutrient deprivation at the end of the experiment. HOC exposure and fasting were conducted separately and in combination. NL storages were depleted, and lysosomal membranes were destabilised after HOC exposure and nutrient deprivation. These responses were not related specifically to one type of stress or the extent of the treatment. No synergistic or additive effects from the combination of HOC exposure and fasting were observed. LF accumulated, and MDA levels increased as a result of fasting, but were unaffected by HOC exposure. LF accumulation was strongly associated with the percent weight change in the chicks. Large weight loss was associated with high LF levels, and slight weight gain was associated with low LF levels. Hence, food deprivation affected all the measured parameters, and HOC exposure decreased NL levels and lysosomal membrane stability in HG chick liver. Furthermore, autophagic lysosomal parameters have frequently been applied as biomarkers of cellular health status in previous studies of marine and terrestrial invertebrates, and this study suggests that these parameters may be good candidates for biomarkers of cellular health status in seabirds as well.

  1. Citreoviridin Induces Autophagy-Dependent Apoptosis through Lysosomal-Mitochondrial Axis in Human Liver HepG2 Cells.

    Science.gov (United States)

    Wang, Yuexia; Liu, Yanan; Liu, Xiaofang; Jiang, Liping; Yang, Guang; Sun, Xiance; Geng, Chengyan; Li, Qiujuan; Yao, Xiaofeng; Chen, Min

    2015-08-06

    Citreoviridin (CIT) is a mycotoxin derived from fungal species in moldy cereals. In our previous study, we reported that CIT stimulated autophagosome formation in human liver HepG2 cells. Here, we aimed to explore the relationship of autophagy with lysosomal membrane permeabilization and apoptosis in CIT-treated cells. Our data showed that CIT increased the expression of LC3-II, an autophagosome biomarker, from the early stage of treatment (6 h). After treatment with CIT for 12 h, lysosomal membrane permeabilization occurred, followed by the release of cathepsin D in HepG2 cells. Inhibition of autophagosome formation with siRNA against Atg5 attenuated CIT-induced lysosomal membrane permeabilization. In addition, CIT induced collapse of mitochondrial transmembrane potential as assessed by JC-1 staining. Furthermore, caspase-3 activity assay showed that CIT induced apoptosis in HepG2 cells. Inhibition of autophagosome formation attenuated CIT-induced apoptosis, indicating that CIT-induced apoptosis was autophagy-dependent. Cathepsin D inhibitor, pepstatin A, relieved CIT-induced apoptosis as well, suggesting the involvement of the lysosomal-mitochondrial axis in CIT-induced apoptosis. Taken together, our data demonstrated that CIT induced autophagy-dependent apoptosis through the lysosomal-mitochondrial axis in HepG2 cells. The study thus provides essential mechanistic insight, and suggests clues for the effective management and treatment of CIT-related diseases.

  2. A novel approach to analyze lysosomal dysfunctions through subcellular proteomics and lipidomics: the case of NPC1 deficiency

    Science.gov (United States)

    Tharkeshwar, Arun Kumar; Trekker, Jesse; Vermeire, Wendy; Pauwels, Jarne; Sannerud, Ragna; Priestman, David A.; Te Vruchte, Danielle; Vints, Katlijn; Baatsen, Pieter; Decuypere, Jean-Paul; Lu, Huiqi; Martin, Shaun; Vangheluwe, Peter; Swinnen, Johannes V.; Lagae, Liesbet; Impens, Francis; Platt, Frances M.; Gevaert, Kris; Annaert, Wim

    2017-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have mainly been used as cellular carriers for genes and therapeutic products, while their use in subcellular organelle isolation remains underexploited. We engineered SPIONs targeting distinct subcellular compartments. Dimercaptosuccinic acid-coated SPIONs are internalized and accumulate in late endosomes/lysosomes, while aminolipid-SPIONs reside at the plasma membrane. These features allowed us to establish standardized magnetic isolation procedures for these membrane compartments with a yield and purity permitting proteomic and lipidomic profiling. We validated our approach by comparing the biomolecular compositions of lysosomes and plasma membranes isolated from wild-type and Niemann-Pick disease type C1 (NPC1) deficient cells. While the accumulation of cholesterol and glycosphingolipids is seen as a primary hallmark of NPC1 deficiency, our lipidomics analysis revealed the buildup of several species of glycerophospholipids and other storage lipids in selectively late endosomes/lysosomes of NPC1-KO cells. While the plasma membrane proteome remained largely invariable, we observed pronounced alterations in several proteins linked to autophagy and lysosomal catabolism reflecting vesicular transport obstruction and defective lysosomal turnover resulting from NPC1 deficiency. Thus the use of SPIONs provides a major advancement in fingerprinting subcellular compartments, with an increased potential to identify disease-related alterations in their biomolecular compositions.

  3. GTPase of the Immune-Associated Nucleotide Protein 5 Regulates the Lysosomal Calcium Compartment in T Lymphocytes

    Science.gov (United States)

    Serrano, Daniel; Ghobadi, Farnaz; Boulay, Guylain; Ilangumaran, Subburaj; Lavoie, Christine; Ramanathan, Sheela

    2017-01-01

    T lymphocytes from Gimap5lyp/lyp rats carrying a recessive mutation in the GTPase of immune-associated protein 5 (Gimap5) gene undergo spontaneous apoptosis. Molecular mechanisms underlying this survival defect are not yet clear. We have shown that Gimap5lyp/lyp T lymphocytes display reduced calcium influx following T cell antigen receptor (TCR) stimulation that was associated with impaired buffering of calcium by mitochondria. Here, we investigated the subcellular localization of GIMAP5 and its influence on Ca2+ response in HEK293T cells and T lymphocytes. The more abundantly expressed GIMAP5v2 localizes to the lysosome and certain endosomal vesicles. Gimap5lyp/lyp T lymphocytes showed increased accumulation of calcium in the lysosomes as evidenced by Gly-Phe β-naphthylamide (GPN) triggered Ca2+ release. As a corollary, GPN-induced Ca2+ flux was decreased in HEK293T cells expressing GIMAP5v2. Strikingly, TCR stimulation of rat, mouse, and human T lymphocytes increased lysosomal calcium content. Overall, our findings show that lysosomes modulate cellular Ca2+ response during T cell activation and that GIMAP5 regulates the lysosomal Ca2+ compartment in T lymphocytes. PMID:28223986

  4. Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Dong, E-mail: austhudong@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wu, Jing, E-mail: wujing8008@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Xiao, Jian [School of Pharmacy, Wenzhou Medical College, Wenzhou (China); Hu, Fengyu; Yang, Yabo [Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou (China); Zhang, Rongbo, E-mail: lory456@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China)

    2015-05-29

    The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy.

  5. A novel approach to analyze lysosomal dysfunctions through subcellular proteomics and lipidomics: the case of NPC1 deficiency

    Science.gov (United States)

    Tharkeshwar, Arun Kumar; Trekker, Jesse; Vermeire, Wendy; Pauwels, Jarne; Sannerud, Ragna; Priestman, David A.; te Vruchte, Danielle; Vints, Katlijn; Baatsen, Pieter; Decuypere, Jean-Paul; Lu, Huiqi; Martin, Shaun; Vangheluwe, Peter; Swinnen, Johannes V.; Lagae, Liesbet; Impens, Francis; Platt, Frances M.; Gevaert, Kris; Annaert, Wim

    2017-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have mainly been used as cellular carriers for genes and therapeutic products, while their use in subcellular organelle isolation remains underexploited. We engineered SPIONs targeting distinct subcellular compartments. Dimercaptosuccinic acid-coated SPIONs are internalized and accumulate in late endosomes/lysosomes, while aminolipid-SPIONs reside at the plasma membrane. These features allowed us to establish standardized magnetic isolation procedures for these membrane compartments with a yield and purity permitting proteomic and lipidomic profiling. We validated our approach by comparing the biomolecular compositions of lysosomes and plasma membranes isolated from wild-type and Niemann-Pick disease type C1 (NPC1) deficient cells. While the accumulation of cholesterol and glycosphingolipids is seen as a primary hallmark of NPC1 deficiency, our lipidomics analysis revealed the buildup of several species of glycerophospholipids and other storage lipids in selectively late endosomes/lysosomes of NPC1-KO cells. While the plasma membrane proteome remained largely invariable, we observed pronounced alterations in several proteins linked to autophagy and lysosomal catabolism reflecting vesicular transport obstruction and defective lysosomal turnover resulting from NPC1 deficiency. Thus the use of SPIONs provides a major advancement in fingerprinting subcellular compartments, with an increased potential to identify disease-related alterations in their biomolecular compositions. PMID:28134274

  6. Operation characteristics of AMS-02 loop heat pipe with bypass valve

    CERN Document Server

    Wang, N H; Xin, G M; Song, J W; Cui, Z; Burger, J; Du, W J; Luo, F; Cheng, L

    2011-01-01

    Loop heat pipes (LHPs) were designed for the alpha magnetic spectrometer (AMS-02) to dissipate heat from the cryocoolers. A bypass valve is applied to the LHP to keep the cryocooler temperature above its limit (-20A degrees C) in cold environment. Extensive experiments were performed on operation characteristics of LHPs with the bypass valve for AMS-02 during thermal vacuum and thermal balance (TVTB) test. We found that the bypass valve can start up successfully in cold environment. With the bypass valve, the evaporator temperature is stable and can meet the requirement of the cryocooler. We analyzed three operating modes of the bypass valve. Set point temperature and regulation temperature shifts were observed and their relations with the bypass valve temperature were given.

  7. Novel blood sampling method of an artificial endocrine pancreas via the cardiopulmonary bypass circuit.

    Science.gov (United States)

    Kawahito, Shinji; Higuchi, Seiichi; Mita, Naoji; Kitagawa, Tetsuya; Kitahata, Hiroshi

    2013-12-01

    We tried to perform continuous blood glucose monitoring during cardiovascular surgery involving cardiopulmonary bypass using an artificial endocrine pancreas (STG-22 or -55; Nikkiso, Tokyo, Japan); however, we often encountered problems during these procedures because insufficient blood was obtained for monitoring. Thus, we started performing the blood sampling via the venous side of the cardiopulmonary bypass circuit. As a result, continuous blood glucose monitoring using an artificial endocrine pancreas was proven to be stable and reliable during cardiovascular surgery involving cardiopulmonary bypass.

  8. Analysis of mucolipidosis II/III GNPTAB missense mutations identifies domains of UDP-GlcNAc:lysosomal enzyme GlcNAc-1-phosphotransferase involved in catalytic function and lysosomal enzyme recognition.

    Science.gov (United States)

    Qian, Yi; van Meel, Eline; Flanagan-Steet, Heather; Yox, Alex; Steet, Richard; Kornfeld, Stuart

    2015-01-30

    UDP-GlcNAc:lysosomal enzyme GlcNAc-1-phosphotransferase tags newly synthesized lysosomal enzymes with mannose 6-phosphate recognition markers, which are required for their targeting to the endolysosomal system. GNPTAB encodes the α and β subunits of GlcNAc-1-phosphotransferase, and mutations in this gene cause the lysosomal storage disorders mucolipidosis II and III αβ. Prior investigation of missense mutations in GNPTAB uncovered amino acids in the N-terminal region and within the DMAP domain involved in Golgi retention of GlcNAc-1-phosphotransferase and its ability to specifically recognize lysosomal hydrolases, respectively. Here, we undertook a comprehensive analysis of the remaining missense mutations in GNPTAB reported in mucolipidosis II and III αβ patients using cell- and zebrafish-based approaches. We show that the Stealth domain harbors the catalytic site, as some mutations in these regions greatly impaired the activity of the enzyme without affecting its Golgi localization and proteolytic processing. We also demonstrate a role for the Notch repeat 1 in lysosomal hydrolase recognition, as missense mutations in conserved cysteine residues in this domain do not affect the catalytic activity but impair mannose phosphorylation of certain lysosomal hydrolases. Rescue experiments using mRNA bearing Notch repeat 1 mutations in GNPTAB-deficient zebrafish revealed selective effects on hydrolase recognition that differ from the DMAP mutation. Finally, the mutant R587P, located in the spacer between Notch 2 and DMAP, was partially rescued by overexpression of the γ subunit, suggesting a role for this region in γ subunit binding. These studies provide new insight into the functions of the different domains of the α and β subunits.

  9. The role of bypass diodes in the failure of solar battery charging stations in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Greacen, C.; Green, D. [Energy and Resources Group, 310 Barrows Hall no. 3050, University of California, 94720-3050 Berkeley, CA (United States)

    2001-12-15

    This paper focuses on the failure of bypass diodes in solar battery charging stations (SBCS) in Thailand. The Thai government has installed over 1000 SBCS in unelectrified villages to be used to charge 12-V batteries for household lights and small appliances. The unnecessary inclusion of bypass diodes in these systems created an unexpected failure mode when villagers misconnected their batteries with reverse polarity. In a survey of 31 stations, 18 stations were disabled by burnt-out bypass diodes. The electrical engineering theory of this failure mode is analyzed. In addition, we discuss how the bypass diode failures have been compounded by lack of end-user feedback to the implementing agencies.

  10. The isolation of lysosomes from Ehrlich ascites tumor cells following pretreatment of mice with Triton WR-1339.

    Science.gov (United States)

    Horvat, A; Baxandall, J; Touster, O

    1969-08-01

    A method is described for obtaining highly purified lysosomes from Ehrlich ascites tumo cells grown in mice injected with Triton WR-1339. The isolated particles show a high specific activity for aryl sulfatase, representing an 80-90-fold purification over the homogenate, and a 15-18% yield of the total enzyme activity. Mitochondrial and microsomal marker enzymes are present in negligible amounts (0.2% of the activity of the homogenate). The biochemical evidence for a rather high degree of homogeneity of the fraction is supported by the electron microscopic examination of the purified lysosomes. The intracellular localizations of N-acetyl-beta-glucosaminidase, NADH-cytochrome c reductase and NADPH-cytochrome c reductase in Ehrlich ascites cells are also reported, the first two being present in highest concentration in the combined mitochondrial-lysosomal fraction and the third in the microsomal fraction.

  11. LINGO-1 promotes lysosomal degradation of amyloid-β protein precursor.

    Science.gov (United States)

    de Laat, Rian; Meabon, James S; Wiley, Jesse C; Hudson, Mark P; Montine, Thomas J; Bothwell, Mark

    2015-01-01

    Sequential proteolytic cleavages of amyloid-β protein precursor (AβPP) by β-secretase and γ-secretase generate amyloid β (Aβ) peptides, which are thought to contribute to Alzheimer's disease (AD). Much of this processing occurs in endosomes following endocytosis of AβPP from the plasma membrane. However, this pathogenic mode of processing AβPP may occur in competition with lysosomal degradation of AβPP, a common fate of membrane proteins trafficking through the endosomal system. Following up on published reports that LINGO-1 binds and promotes the amyloidogenic processing of AβPP we have examined the consequences of LINGO-1/AβPP interactions. We report that LINGO-1 and its paralogs, LINGO-2 and LINGO-3, decrease processing of AβPP in the amyloidogenic pathway by promoting lysosomal degradation of AβPP. We also report that LINGO-1 levels are reduced in AD brain, representing a possible pathogenic mechanism stimulating the generation of Aβ peptides in AD.

  12. LINGO-1 promotes lysosomal degradation of amyloid-β protein precursor

    Directory of Open Access Journals (Sweden)

    Rian de Laat

    2015-03-01

    Full Text Available Sequential proteolytic cleavages of amyloid-β protein precursor (AβPP by β-secretase and γ-secretase generate amyloid β (Aβ peptides, which are thought to contribute to Alzheimer's disease (AD. Much of this processing occurs in endosomes following endocytosis of AβPP from the plasma membrane. However, this pathogenic mode of processing AβPP may occur in competition with lysosomal degradation of AβPP, a common fate of membrane proteins trafficking through the endosomal system. Following up on published reports that LINGO-1 binds and promotes the amyloidogenic processing of AβPP we have examined the consequences of LINGO-1/AβPP interactions. We report that LINGO-1 and its paralogs, LINGO-2 and LINGO-3, decrease processing of AβPP in the amyloidogenic pathway by promoting lysosomal degradation of AβPP. We also report that LINGO-1 levels are reduced in AD brain, representing a possible pathogenic mechanism stimulating the generation of Aβ peptides in AD.

  13. Deleterious effects of interruption followed by reintroduction of enzyme replacement therapy on a lysosomal storage disorder.

    Science.gov (United States)

    Schneider, Ana Paula; Matte, Ursula; Pasqualim, Gabriela; Tavares, Angela Maria Vicente; Mayer, Fabiana Quoos; Martinelli, Barbara; Ribas, Graziela; Vargas, Carmen Regla; Giugliani, Roberto; Baldo, Guilherme

    2016-10-01

    Temporary interruption of enzyme replacement therapy (ERT) in patients with different lysosomal storage disorders may happen for different reasons (adverse reactions, issues with reimbursement, logistic difficulties, and so forth), and the impact of the interruption is still uncertain. In the present work, we studied the effects of the interruption of intravenous ERT (Laronidase, Genzyme) followed by its reintroduction in mice with the prototypical lysosomal storage disorder mucopolysaccharidosis type I, comparing to mice receiving continuous treatment, untreated mucopolysaccharidosis type I mice, and normal mice. In the animals which treatment was temporarily interrupted, we observed clear benefits of treatment in several organs (liver, lung, heart, kidney, and testis) after reintroduction, but a worsening in the thickness of the aortic wall was detected. Furthermore, these mice had just partial improvements in behavioral tests, suggesting some deterioration in the brain function. Despite worsening is some disease aspects, urinary glycosaminoglycans levels did not increase during interruption, which indicates that this biomarker commonly used to monitor treatment in patients should not be used alone to assess treatment efficacy. The deterioration observed was not caused by the development of serum antienzyme antibodies. All together our results suggest that temporary ERT interruption leads to deterioration of function in some organs and should be avoided whenever possible.

  14. WO3/Pt nanoparticles promote light-induced lipid peroxidation and lysosomal instability within tumor cells

    Science.gov (United States)

    Clark, Andrea J.; Petty, Howard R.

    2016-02-01

    Although metal-metal oxide nanoparticles have attracted considerable interest as catalysts, they have attracted little interest in nanomedicine. This is likely due to the fact that metal oxide semiconductors generally require biologically harmful ultraviolet excitation. In contrast, this study focuses upon WO3/Pt nanoparticles, which can be excited by visible light. To optimize the nanoparticles’ catalytic performance, platinization was performed at alkaline pH. These nanoparticles destroyed organic dyes, consumed dissolved oxygen and produced hydroxyl radicals. 4T1 breast cancer cells internalized WO3/Pt nanoparticles within the membrane-bound endo-lysosomal compartment as shown by electron and fluorescence microscopy. During visible light exposure, but not in darkness, WO3/Pt nanoparticles manufacture reactive oxygen species, promote lipid peroxidation, and trigger lysosomal membrane disruption. As cells of the immune system degrade organic molecules, produce reactive oxygen species, and activate the lipid peroxidation pathway within target cells, these nanoparticles mimic the chemical attributes of immune effector cells. These biomimetic nanoparticles should become useful in managing certain cancers, especially ocular cancer.

  15. The role of autophagic and lysosomal pathways in ischemic brain injury******

    Institute of Scientific and Technical Information of China (English)

    Zhaohua Gu; Nan Shi; Qian Zhang; Wei Zhang; Meizhen Zhao; Xiaojiang Sun; Yinyi Sun; Kangyong Liu; Fen Wang; Ting Zhang; Qiang Li; Liwei Shen; Ling Zhou; Liang Dong

    2013-01-01

    Autophagy is involved in neural cel death after cerebral ischemia. Our previous studies showed that rapamycin-induced autophagy decreased the rate of apoptosis, but the rate of apoptosis was creased after the autophagy inhibitor, 3-methyladenine, was used. In this study, a suture-occluded method was performed to generate a rat model of brain ischemia. Under a transmission electron microscope, autophagic bodies and autophagy lysosomes were markedly accumulated in neurons at 4 hours post brain ischemic injury, with their numbers gradual y reducing over time. Western blotting demonstrated that protein levels of light chain 3-II and cathepsin B were significantly in-creased within 4 hours of ischemic injury, but these levels were not persistently upregulated over time. Confocal microscopy showed that autophagy was mainly found in neurons with positive light chain 3 signal. Injection of rapamycin via tail vein promoted the occurrence of autophagy in rat brain tissue after cerebral ischemia and elevated light chain 3 and cathepsin B expression. However, in-jection of 3-methyladenine significantly diminished light chain 3-II and cathepsin B expression. Results verified that autophagic and lysosomal activity is increased in ischemic neurons. Abnormal components in cel s can be eliminated through upregulating cel autophagy or inhibiting autophagy after ischemic brain injury, resulting in a dynamic balance of substances in cel s. Moreover, drugs that interfere with autophagy may be potential therapies for the treatment of brain injury.

  16. Variations of lysosomal enzymes in different parts of rabbit Fallopian tube during ovum transport.

    Science.gov (United States)

    Puri, R K; Roy, S K

    1981-03-01

    Some lysosomal enzymes (viz., acid DNase, acid RNase and beta-glucuronidase) were estimated in different parts of the rabbit Fallopian tube during different hours post coitum (p. c.). At estrus, alterations of acid RNase and beta-glucuronidase were observed in different anatomical segments of the Fallopian tube but acid DNase was undetectable. When these enzymes were compared at different hours p.c., it was noticed that when the ovum reaches ampullary (A), ampullary-isthmic junction (AIJ) and isthmic (I) segments of the Fallopian tube at the respective hours 14, 24 and 70, the acid DNase activity showed increased value in these parts when compared to their preceding groups. Acid RNase also showed similar type of pattern except that it was not altered at 14 hr p. c. At 144 hr p. c. both the enzymes had no significant alteration over 70 hr value, beta-glucuronidase, however, did not show this type of pattern in all the segments till 144 hr p. c. The increased activity of acid RNase and DNase in AIJ and I segments of the tube till 70 hr p. c. suggests the increased lysosomal activity in the tubal fluid produced by secretory cells. The possible involvement of these lysomal factors in the process of fertilization and preparation of ovum prior to implantation is suggested.

  17. [High cost drugs for rare diseases in Brazil: the case of lysosomal storage disorders].

    Science.gov (United States)

    de Souza, Mônica Vinhas; Krug, Bárbara Corrêa; Picon, Paulo Dornelles; Schwartz, Ida Vanessa Doederlein

    2010-11-01

    This paper approaches in a critical way aspects of Brazilian public policies for drugs, emphasizing those classified as high cost and for rare diseases. The lysosomal storage diseases was taken as an example because of their rarity and the international trend for the development of new drugs for their treatment, all at high costs. Three lysosomal storage diseases were approached: Gaucher disease, Fabry disease and mucopolysaccharidosis type I. Gaucher disease has its treatment drug licensed in Brazil and guidelines for its use are established through a clinical protocol by the Ministry of Health. The others have their drug treatments registered in Brazil; however, no treatment guidelines for them have been developed by the government. The objective of the paper was to foster the discussion on the role of health technology assessment for high-cost drugs for rare diseases in Brazil, emphasizing the need for establishing health policies with legitimacy towards these diseases. Despite the difficulties in establishing a health policy for each rare disease, it is possible to create rational models to deal with this growing challenge.

  18. Low Serum Lysosomal Acid Lipase Activity Correlates with Advanced Liver Disease

    Directory of Open Access Journals (Sweden)

    Eyal Shteyer

    2016-02-01

    Full Text Available Fatty liver has become the most common liver disorder and is recognized as a major health burden in the Western world. The causes for disease progression are not fully elucidated but lysosomal impairment is suggested. Here we evaluate a possible role for lysosomal acid lipase (LAL activity in liver disease. To study LAL levels in patients with microvesicular, idiopathic cirrhosis and nonalcoholic fatty liver disease (NAFLD. Medical records of patients with microvesicular steatosis, cryptogenic cirrhosis and NAFLD, diagnosed on the basis of liver biopsies, were included in the study. Measured serum LAL activity was correlated to clinical, laboratory, imaging and pathological data. No patient exhibited LAL activity compatible with genetic LAL deficiency. However, serum LAL activity inversely predicted liver disease severity. A LAL level of 0.5 was the most sensitive for detecting both histologic and noninvasive markers for disease severity, including lower white blood cell count and calcium, and elevated γ-glutamyltransferase, creatinine, glucose, glycated hemoglobin, uric acid and coagulation function. Serum LAL activity <0.5 indicates severe liver injury in patients with fatty liver and cirrhosis. Further studies should define the direct role of LAL in liver disease severity and consider the possibility of replacement therapy.

  19. Phase coexistence in a triolein-phosphatidylcholine system. Implications for lysosomal membrane properties.

    Science.gov (United States)

    Pakkanen, Kirsi I; Duelund, Lars; Vuento, Matti; Ipsen, John Hjort

    2010-02-01

    The effects of tri- and monoglycerides on phospholipid (POPC) membranes were studied using spectroscopical methods. Triolein was found to form two types of POPC-rich membranes, both with POPC or as a three-component system with monopalmitin. These two membrane types were determined as co-existing phases based on their spontaneous and stable separation and named heavy and light phase according to their sedimentation behaviour. Marked differences were seen in the physical properties of these phases, even though only minor compositional variation was detected. The light, less polar phase was found to be less ordered and more fluid and seemed to allow significantly lower amount of water penetration into the membrane-water interface than pure POPC membrane. The heavy phase, apart from their slightly altered water penetration, resembled more a pure POPC membrane. As triglycerides are present in lysosomal membranes, the present results can be seen as an implication for polarity-based water permeability barrier possibly contributing to the integrity of lysosomes.

  20. Mucopolysaccharidosis IIIB, a lysosomal storage disease, triggers a pathogenic CNS autoimmune response

    Directory of Open Access Journals (Sweden)

    Popovich Phillip G

    2010-07-01

    Full Text Available Abstract Background Recently, using a mouse model of mucopolysaccharidosis (MPS IIIB, a lysosomal storage disease with severe neurological deterioration, we showed that MPS IIIB neuropathology is accompanied by a robust neuroinflammatory response of unknown consequence. This study was to assess whether MPS IIIB lymphocytes are pathogenic. Methods Lymphocytes from MPS IIIB mice were adoptively transferred to naïve wild-type mice. The recipient animals were then evaluated for signs of disease and inflammation in the central nervous system. Results Our results show for the first time, that lymphocytes isolated from MPS IIIB mice caused a mild paralytic disease when they were injected systemically into naïve wild-type mice. This disease is characterized by mild tail and lower trunk weakness with delayed weight gain. The MPS IIIB lymphocytes also trigger neuroinflammation within the CNS of recipient mice characterized by an increase in transcripts of IL2, IL4, IL5, IL17, TNFα, IFNα and Ifi30, and intraparenchymal lymphocyte infiltration. Conclusions Our data suggest that an autoimmune response directed at CNS components contributes to MPS IIIB neuropathology independent of lysosomal storage pathology. Adoptive transfer of purified T-cells will be needed in future studies to identify specific effector T-cells in MPS IIIB neuroimmune pathogenesis.