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Sample records for cd1c bypasses lysosomes

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

    Directory of Open Access Journals (Sweden)

    Harald Schwarz

    Full Text Available 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.

  2. 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.

  3. The awesome lysosome

    OpenAIRE

    Ballabio, Andrea

    2016-01-01

    In the early 50s, Christian De Duve identified a new cellular structure, the lysosome, defined as the cell's “suicide bag” (de Duve, 2005). Sixty years later, it is clear that the lysosome greatly exceeded the expectations of its discoverer. Over 50 different types of lysosomal storage diseases have been identified, each due to the deficiency or malfunction of a specific lysosomal protein. In addition, an important role of the lysosome has been unveiled in several common human diseases, such ...

  4. Proteomics of the Lysosome

    OpenAIRE

    Lübke, Torben; Lobel, Peter; Sleat, David

    2008-01-01

    Defects in lysosomal function have been associated with numerous monogenic human diseases typically classified as lysosomal storage diseases. However, there is increasing evidence that lysosomal proteins are also involved in more widespread human diseases including cancer and Alzheimer disease. Thus, there is a continuing interest in understanding the cellular functions of the lysosome and an emerging approach to this is the identification of its constituent proteins by proteomic analyses. To...

  5. Lysosome Transport as a Function of Lysosome Diameter

    OpenAIRE

    Debjyoti Bandyopadhyay; Austin Cyphersmith; Zapata, Jairo A.; Y Joseph Kim; Payne, Christine K.

    2014-01-01

    Lysosomes are membrane-bound organelles responsible for the transport and degradation of intracellular and extracellular cargo. The intracellular motion of lysosomes is both diffusive and active, mediated by motor proteins moving lysosomes along microtubules. We sought to determine how lysosome diameter influences lysosome transport. We used osmotic swelling to double the diameter of lysosomes, creating a population of enlarged lysosomes. This allowed us to directly examine the intracellular ...

  6. 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.

  7. Targeting the lysosome in cancer

    OpenAIRE

    Piao, Shengfu; Amaravadi, Ravi K.

    2015-01-01

    Lysosomes are membrane-bound intracellular organelles that receive macromolecules delivered by endocytosis, phagocytosis, and autophagy for degradation and recycling. Over the last decade, advances in lysosome research have established a broad role for the lysosome in the pathophysiology of disease. In this review, we highlight the recent discoveries in lysosome biology, with an emphasis on their implications for cancer therapy. We focus on targeting the lysosome in cancer by exploring lysoso...

  8. TFEB regulates lysosomal proteostasis.

    Science.gov (United States)

    Song, Wensi; Wang, Fan; Savini, Marzia; Ake, Ashley; di Ronza, Alberto; Sardiello, Marco; Segatori, Laura

    2013-05-15

    Loss-of-function diseases are often caused by destabilizing mutations that lead to protein misfolding and degradation. Modulating the innate protein homeostasis (proteostasis) capacity may lead to rescue of native folding of the mutated variants, thereby ameliorating the disease phenotype. In lysosomal storage disorders (LSDs), a number of highly prevalent alleles have missense mutations that do not impair the enzyme's catalytic activity but destabilize its native structure, resulting in the degradation of the misfolded protein. Enhancing the cellular folding capacity enables rescuing the native, biologically functional structure of these unstable mutated enzymes. However, proteostasis modulators specific for the lysosomal system are currently unknown. Here, we investigate the role of the transcription factor EB (TFEB), a master regulator of lysosomal biogenesis and function, in modulating lysosomal proteostasis in LSDs. We show that TFEB activation results in enhanced folding, trafficking and lysosomal activity of a severely destabilized glucocerebrosidase (GC) variant associated with the development of Gaucher disease (GD), the most common LSD. TFEB specifically induces the expression of GC and of key genes involved in folding and lysosomal trafficking, thereby enhancing both the pool of mutated enzyme and its processing through the secretory pathway. TFEB activation also rescues the activity of a β-hexosaminidase mutant associated with the development of another LSD, Tay-Sachs disease, thus suggesting general applicability of TFEB-mediated proteostasis modulation to rescue destabilizing mutations in LSDs. In summary, our findings identify TFEB as a specific regulator of lysosomal proteostasis and suggest that TFEB may be used as a therapeutic target to rescue enzyme homeostasis in LSDs. PMID:23393155

  9. Heart bypass surgery

    Science.gov (United States)

    Off-pump coronary artery bypass; OPCAB; Beating heart surgery; Bypass surgery - heart; CABG; Coronary artery bypass graft; Coronary artery bypass surgery; Coronary bypass surgery; Coronary artery disease - CABG; CAD - CABG; Angina - ...

  10. The Biogenesis of Lysosomes and Lysosome-Related Organelles

    Science.gov (United States)

    Luzio, J. Paul; Hackmann, Yvonne; Dieckmann, Nele M.G.; Griffiths, Gillian M.

    2014-01-01

    Lysosomes were once considered the end point of endocytosis, simply used for macromolecule degradation. They are now recognized to be dynamic organelles, able to fuse with a variety of targets and to be re-formed after fusion events. They are also now known to be the site of nutrient sensing and signaling to the cell nucleus. In addition, lysosomes are secretory organelles, with specialized machinery for regulated secretion of proteins in some cell types. The biogenesis of lysosomes and lysosome-related organelles is discussed, taking into account their dynamic nature and multiple roles. PMID:25183830

  11. 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.

  12. 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......-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...

  13. Lysosomal Adaptation: How the Lysosome Responds to External Cues

    OpenAIRE

    Settembre, C.; Ballabio, A

    2014-01-01

    Recent evidence indicates that the importance of the lysosome in cell metabolism and organism physiology goes far beyond the simple disposal of cellular garbage. This dynamic organelle is situated at the crossroad of the most important cellular pathways and is involved in sensing, signaling, and transcriptional mechanisms that respond to environmental cues, such as nutrients. Two main mediators of these lysosomal adaptation mechanisms are the mTORC1 kinase complex and the transcription factor...

  14. The enlarged lysosomes in beigej cells result from decreased lysosome fission and not increased lysosome fusion

    OpenAIRE

    Durchfort, Nina; Verhoef, Shane; Vaughn, Michael B.; Shrestha, Rishna; Adam, Dieter; Kaplan, Jerry; Ward, Diane McVey

    2011-01-01

    Chediak-Higashi Syndrome is an autosomal recessive disorder that affects vesicle morphology. The Chs1/Lyst protein is a member of the BEACH family of proteins. The absence of Chs1/Lyst gives rise to enlarged lysosomes. Lysosome size is regulated by a balance between vesicle fusion and fission and can be reversibly altered by acidifying the cytoplasm using Acetate Ringer’s or by incubating with the drug vacuolin-1. We took advantage of these procedures to determine rates of lysosome fusion and...

  15. Mice Doubly-Deficient in Lysosomal Hexosaminidase A and Neuraminidase 4 Show Epileptic Crises and Rapid Neuronal Loss

    OpenAIRE

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

  16. Lysosomal cell death at a glance

    DEFF Research Database (Denmark)

    Aits, Sonja; Jaattela, Marja

    2013-01-01

    Lysosomes serve as the cellular recycling centre and are filled with numerous hydrolases that can degrade most cellular macromolecules. Lysosomal membrane permeabilization and the consequent leakage of the lysosomal content into the cytosol leads to so-called "lysosomal cell death". This form...... of cell death is mainly carried out by the lysosomal cathepsin proteases and can have necrotic, apoptotic or apoptosis-like features depending on the extent of the leakage and the cellular context. This article summarizes our current knowledge on lysosomal cell death with an emphasis on the upstream...

  17. 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 ...

  18. Coronary Artery Bypass Surgery

    Science.gov (United States)

    ... don't help, you may need coronary artery bypass surgery. The surgery creates a new path for ... narrowed area or blockage. This allows blood to bypass (get around) the blockage. Sometimes people need more ...

  19. 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 ...

  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. Impaired lysosomal cobalamin transport in Alzheimer's disease.

    Science.gov (United States)

    Zhao, Hua; Li, Hongyun; Ruberu, Kalani; Garner, Brett

    2015-01-01

    Cobalamin (vitamin B12) is required for erythrocyte formation and DNA synthesis and it plays a crucial role in maintaining neurological function. As a coenzyme for methionine synthase and methylmalonyl-CoA mutase, cobalamin utilization depends on its efficient transit through the intracellular lysosomal compartment and subsequent delivery to the cytosol and mitochondria. Lysosomal function deteriorates in Alzheimer's disease (AD). Lysosomal acidification is defective in AD and lysosomal proteolysis is disrupted by AD-related presenilin 1 mutation. In this study, we propose that AD related lysosomal dysfunction may impair lysosomal cobalamin transport. The experiments use in vitro and in vivo models of AD to define how lysosomal dysfunction directly affects cobalamin utilization. SH-SY5Y-AβPP mutant cells were treated with a proteasome inhibitor to induce lysosomal amyloid-β accumulation. We metabolically labeled these cells with [57Co] cobalamin and isolated purified lysosomes, mitochondria, and cytosol fractions. The results indicated that proteasome inhibition was associated with lysosomal amyloid-β accumulation and a doubling of lysosomal [57Co] cobalamin levels. We also used AβPPxPS1 transgenic AD mice that were intraperitoneally injected with [57Co] cobalamin. The amount of [57Co] cobalamin in the major organs of these mice was measured and the subcellular [57Co] cobalamin distribution in the brain was assessed. The results demonstrated that lysosomal [57Co] cobalamin level was significantly increased by 56% in the AβPPxPS1 AD mouse brains as compared to wild type control mice. Together these data provide evidence that lysosomal cobalamin may be impaired in AD in association with amyloid-β accumulation. PMID:25125476

  2. Heart bypass surgery - minimally invasive

    Science.gov (United States)

    Minimally invasive direct coronary artery bypass; MIDCAB; Robot assisted coronary artery bypass; RACAB; Keyhole heart surgery ... doctor may recommend a minimally invasive coronary artery bypass if you have a blockage in one or ...

  3. 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.

  4. Role of lysosomes in cancer therapy

    Directory of Open Access Journals (Sweden)

    Halaby R

    2015-09-01

    Full Text Available Reginald Halaby Department of Biology, Montclair State University, Montclair, NJ, USA Abstract: Lysosomes are acidic organelles that are involved in cellular digestion by endocytosis, phagocytosis, and autophagy. They contain more than 50 hydrolases that are capable of degrading all macromolecules. There is accumulating evidence that lysosomal enzymes can provoke apoptotic cell death. This has important implications for cancer, where proapoptotic genes are mutated and antiapoptotic genes are often overexpressed leading to chemoresistance. Lysosomes play a dual role in cancer development depending on their subcellular localization. When they are located extracellularly they can promote invasion, angiogenesis, and metastasis. However, when they are located intracellularly they can trigger apoptosis by leaking into the cytosol. In this review, we examine the pathways by which lysosomes can evoke both apoptosis and tumorigenesis. Although cancer cells have defects in their apoptotic machinery, they can still undergo lysosomal cell death. We offer several strategies to explain how targeting lysosomes can serve as a putative model for the development of novel anticancer agents. Furthermore, we propose that lysosomal cell death is an effective treatment against apoptosis-resistant cancer cells and thus holds great potential as a therapeutic strategy for circumventing apoptosis deficiency in tumors. Keywords: cathepsins, lysosomal membrane permeability, apoptosis, chemoresistance 

  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. PMID:26950892

  6. Nanoparticles restore lysosomal acidification defects: Implications for Parkinson and other lysosomal-related diseases.

    Science.gov (United States)

    Bourdenx, Mathieu; Daniel, Jonathan; Genin, Emilie; Soria, Federico N; Blanchard-Desce, Mireille; Bezard, Erwan; Dehay, Benjamin

    2016-01-01

    Lysosomal impairment causes lysosomal storage disorders (LSD) and is involved in pathogenesis of neurodegenerative diseases, notably Parkinson disease (PD). Strategies enhancing or restoring lysosomal-mediated degradation thus appear as tantalizing disease-modifying therapeutics. Here we demonstrate that poly(DL-lactide-co-glycolide) (PLGA) acidic nanoparticles (aNP) restore impaired lysosomal function in a series of toxin and genetic cellular models of PD, i.e. ATP13A2-mutant or depleted cells or glucocerebrosidase (GBA)-mutant cells, as well as in a genetic model of lysosomal-related myopathy. We show that PLGA-aNP are transported to the lysosome within 24 h, lower lysosomal pH and rescue chloroquine (CQ)-induced toxicity. Re-acidification of defective lysosomes following PLGA-aNP treatment restores lysosomal function in different pathological contexts. Finally, our results show that PLGA-aNP may be detected after intracerebral injection in neurons and attenuate PD-related neurodegeneration in vivo by mechanisms involving a rescue of compromised lysosomes. PMID:26761717

  7. 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.

  8. 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 ...

  9. Bypass Flow Study

    International Nuclear Information System (INIS)

    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.

  10. 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.

  11. ErbB2-associated changes in the lysosomal proteome

    DEFF Research Database (Denmark)

    Nylandsted, Jesper; Becker, Andrea C; Bunkenborg, Jakob;

    2011-01-01

    Late endosomes and lysosomes (hereafter referred to as lysosomes) play an essential role in the turnover of cellular macromolecules and organelles. Their biochemical characterization has so far depended on purification methods based on either density gradient centrifugations or magnetic...... purification of iron-loaded organelles. Owing to dramatic changes in lysosomal density and stability associated with lysosomal diseases and cancer, these methods are not optimal for the comparison of normal and pathological lysosomes. Here, we introduce an efficient method for the purification of intact...... lysosomes by magnetic immunoprecipitation with antibodies against the vacuolar-type H(+) -ATPase. Quantitative MS-based proteomics analysis of the obtained lysosomal membranes identified 60 proteins, most of which have previously been associated with the lysosomal compartment. Interestingly, the lysosomal...

  12. 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.

  13. 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...

  14. 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

    2010-09-01

    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. PMID:20862357

  15. 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.

  16. Cardiopulmonary bypass in pregnancy.

    Science.gov (United States)

    Pomini, F; Mercogliano, D; Cavalletti, C; Caruso, A; Pomini, P

    1996-01-01

    The cardiopathic patient can sustain acute heart failure during pregnancy. In such cases, if open heart operation is necessary to save the patient's life, the fetus could be seriously compromised after exposure to cardiopulmonary bypass. From 1958 to 1992, 69 reports of cardiac operations during pregnancy with the aid of cardiopulmonary bypass have been published. Maternal mortality was 2.9%. Embryofetal mortality was 20.2%. Examining only the last 40 patients, maternal and embryofetal mortality were 0.0% and 12.5%, respectively. Embryofetal mortality was 24.0% when hypothermia was used, compared with 0.0% while operating in normothermia. Maternal mortality did not change. The use of hypothermia during cardiopulmonary bypass provoked uterine contractions in several patients. Hypothermia decreases O2 exchange through the placenta. Pump flow and mean arterial pressure during cardiopulmonary bypass seem to be the most important parameters that influence fetal oxygenation. We speculate that cardiac operation is not a contraindication to pregnancy prolongation. PMID:8561577

  17. Bypassing AMPK Phosphorylation

    OpenAIRE

    Viollet, Benoit; Foretz, Marc; Schlattner, Uwe

    2014-01-01

    AMP-activated protein kinase (AMPK) functions as a signaling hub to balance energy supply with demand. Phosphorylation of activation loop Thr172 has been considered as an essential step in AMPK activation. In this issue of Chemistry & Biology, Scott and colleagues show that the small molecule direct AMPK activator, A-769662, bypasses this phosphorylation event, and acts synergistically with AMP on naive AMPK.

  18. 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...

  19. 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.

  20. 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.

  1. 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

  2. Screening and Optimization of Ligand Conjugates for Lysosomal Targeting

    OpenAIRE

    Meerovich, Igor; Koshkaryev, Alexander; Thekkedath, Ritesh; Torchilin, Vladimir P.

    2011-01-01

    The use of lysosome-targeted liposomes may significantly improve the delivery of therapeutic enzymes and chaperones into lysosomes for the treatment of lysosomal storage disorders. The aim of this research was to synthesize new potentially lysosomotropic ligands on a base of Neutral Red and rhodamine B and to study their ability to enhance specific lysosomal delivery of surface-modified liposomes loaded with a model compound, fluorescein isothiocyanate-dextran (FD). The delivery of these lipo...

  3. Purification of Lysosomes Using Supraparamagnetic Iron Oxide Nanoparticles (SPIONs).

    Science.gov (United States)

    Rofe, Adam P; Pryor, Paul R

    2016-04-01

    Lysosomes can be rapidly isolated from tissue culture cells using supraparamagnetic iron oxide particles (SPIONs). In this protocol, colloidal iron dextran (FeDex) particles, a type of SPION, are taken up by cultured mouse macrophage cells via the endocytic pathway. The SPIONs accumulate in lysosomes, the end point of the endocytic pathway, permitting the lysosomes to be isolated magnetically. The purified lysosomes are suitable for in vitro fusion assays or for proteomic analysis. PMID:27037068

  4. Axillobifemoral bypass grafting

    Directory of Open Access Journals (Sweden)

    Davidović Lazar B.

    2004-01-01

    Full Text Available INTRODUCTION Axillo-femoral bypass (AxF means connecting the axillar and femoral artery with the graft that is placed subcutaneously [1]. Usually, this graft is connected with contralateral femoral artery via one accessory subcutaneous graft, and this connection is known as axillobifemoral bypass (AxFF. This extra-anatomic procedure is an alternative method to the standard reconstruction of aortoiliac region when there are contraindications for general or local reasons. OBJECTIVE The objective of this paper is to show early and late results of AxFF bypass grafting as well as to show the indications for AxFF bypass. METHODS The sample consisted of 37 patients. The procedure was performed in 28 patients who suffered from aortoiliac occlusive disease and who were at high risk due to the comorbidity- in one patient with the rupture of juxtarenal aneurysm of abdominal aorta; in five patients with aortoenteric fistula, in two patients with iatrogenic lesion of abdominal aorta and in one female patient with anus preternaturalis definitivus who was treated for rectovaginal fistula. Donor's right axillary artery was used in 26 cases (70.3%, and donor's left axillary artery was used in 9 cases (29.7%. Dacron graft was used in 34 patients and Polytetrafluo-roethlylene graft was used in three patients. Simultaneously, profundo-plastic was done in four patients and femoro-popliteal bypass was performed in three patients. In five patients who suffered from aortoenteric fistula, simultaneous intervention of gastrointerstinal system has been done, x2 test was used for statistical evaluation and life table method was used for verification of late graft patency. RESULTS The rate of early postoperative mortality was 13.5%. The causes of death were: sepsis -1, MOFS - 3, and infarct myocardium -1. The mean follow up period was 40.1 months, ranging from six months to 17 years. During the follow up period, an early graft thrombosis was identified in two and late graft

  5. Close encounters of the lysosome/peroxisome kind

    OpenAIRE

    Jin, Yui; Strunk, Bethany S.; Weisman, Lois S.

    2015-01-01

    Lysosomes provide a major source for cellular cholesterol; however, most of this cholesterol is trafficked to the plasma membrane via unknown mechanisms. In this issue of Cell, Chu et al. identify an unexpected role for peroxisomes in the transport of cholesterol from the lysosome to the plasma membrane via a lysosome-peroxisome membrane contact site.

  6. Lysosome-targeted stress reveals increased stability of lipofuscin-containing lysosomes

    OpenAIRE

    Stroikin, Yuri; Mild, Hanna; Johansson, Uno; Roberg, Karin; Öllinger, Karin

    2008-01-01

    Cellular ageing is associated with accumulation of undegradable intralysosomal material, called lipofuscin. In order to accelerate the lipofuscin-accumulation, confluent, growth arrested human fibroblasts were cultured under hyperoxic conditions. To provide a better insight into the effects of lipofuscin on cellular functions, we compared lysosomal stability in control and lipofuscin-loaded human fibroblasts under conditions of lysosome-targeted stress induced by exposure to either the lysoso...

  7. A Proteolytic Cascade Controls Lysosome Rupture and Necrotic Cell Death Mediated by Lysosome-Destabilizing Adjuvants

    OpenAIRE

    Jürgen Brojatsch; Heriberto Lima; Alak K Kar; Jacobson, Lee S.; Stefan M Muehlbauer; Kartik Chandran; Felipe Diaz-Griffero

    2014-01-01

    Recent studies have linked necrotic cell death and proteolysis of inflammatory proteins to the adaptive immune response mediated by the lysosome-destabilizing adjuvants, alum and Leu-Leu-OMe (LLOMe). However, the mechanism by which lysosome-destabilizing agents trigger necrosis and proteolysis of inflammatory proteins is poorly understood. The proteasome is a cellular complex that has been shown to regulate both necrotic cell death and proteolysis of inflammatory proteins. We found that the p...

  8. 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.

  9. 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...

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

    OpenAIRE

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

    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 Torin1), but not by an allosteric inhibitor (rapamycin), leads to activation of lysosomal function. Second, we provided evidence that activation of lysosomal f...

  11. A lysosome-to-nucleus signalling mechanism senses and regulates the lysosome via mTOR and TFEB

    OpenAIRE

    Settembre C; Zoncu R; Medina DL; Vetrini F; Erdin S; Huynh T; Ferron M; Karsenty G; Vellard MC; Facchinetti V; Sabatini DM; Ballabio A.

    2012-01-01

    The lysosome plays a key role in cellular homeostasis by controlling both cellular clearance and energy production to respond to environmental cues. However, the mechanisms mediating lysosomal adaptation are largely unknown. Here, we show that the Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis, colocalizes with master growth regulator mTOR complex 1 (mTORC1) on the lysosomal membrane. When nutrients are present, phosphorylation of TFEB by mTORC1 inhibits TFEB activ...

  12. 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....

  13. Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus

    Science.gov (United States)

    Hole, Camaron R.; Bui, Hoang; Wormley, Floyd L.; Wozniak, Karen L.

    2012-10-01

    Cryptococcus neoformans is an opportunistic pulmonary fungal pathogen that disseminates to the CNS causing fatal meningitis in immunocompromised patients. Dendritic cells (DCs) phagocytose C. neoformans following inhalation. Following uptake, cryptococci translocate to the DC lysosomal compartment and are killed by oxidative and non-oxidative mechanisms. DC lysosomal extracts kill cryptococci in vitro; however, the means of antifungal activity remain unknown. Our studies determined non-oxidative antifungal activity by DC lysosomal extract. We examined DC lysosomal killing of cryptococcal strains, anti-fungal activity of purified lysosomal enzymes, and mechanisms of killing against C. neoformans. Results confirmed DC lysosome fungicidal activity against all cryptococcal serotypes. Purified lysosomal enzymes, specifically cathepsin B, inhibited cryptococcal growth. Interestingly, cathepsin B combined with its enzymatic inhibitors led to enhanced cryptococcal killing. Electron microscopy revealed structural changes and ruptured cryptococcal cell walls following treatment. Finally, additional studies demonstrated that osmotic lysis was responsible for cryptococcal death.

  14. Thrombin during cardiopulmonary bypass.

    Science.gov (United States)

    Edmunds, L Henry; Colman, Robert W

    2006-12-01

    Cardiopulmonary bypass (CPB) ignites a massive defense reaction that stimulates all blood cells and five plasma protein systems to produce a myriad of vasoactive and cytotoxic substances, cell-signaling molecules, and upregulated cellular receptors. Thrombin is the key enzyme in the thrombotic portion of the defense reaction and is only partially suppressed by heparin. During CPB, thrombin is produced by both extrinsic and intrinsic coagulation pathways and activated platelets. The routine use of a cell saver and the eventual introduction of direct thrombin inhibitors now offer the possibility of completely suppressing thrombin production and fibrinolysis during cardiac surgery with CPB. PMID:17126170

  15. 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.

  16. Lysosome: regulator of lipid degradation pathways

    OpenAIRE

    Settembre, Carmine; Ballabio, Andrea

    2014-01-01

    Autophagy is a catabolic pathway that has a fundamental role in the adaptation to fasting and primarily relies on the activity of the endolysosomal system, to which the autophagosome targets substrates for degradation. Recent studies have revealed that the lysosomal–autophagic pathway plays an important part in the early steps of lipid degradation. In this review, we discuss the transcriptional mechanisms underlying co-regulation between lysosome, autophagy, and other steps of lipid catabolis...

  17. 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…

  18. The Role of Microscopy in Understanding Atherosclerotic Lysosomal Lipid Metabolism

    Science.gov (United States)

    Gray Jerome, W.; Yancey, Patricia G.

    2003-02-01

    Microscopy has played a critical role in first identifying and then defining the role of lysosomes in formation of atherosclerotic foam cells. We review the evidence implicating lysosomal lipid accumulation as a factor in the pathogenesis of atherosclerosis with reference to the role of microscopy. In addition, we explore mechanisms by which lysosomal lipid engorgement occurs. Low density lipoproteins which have become modified are the major source of lipid for foam cell formation. These altered lipoproteins are taken into the cell via receptor-mediated endocytosis and delivered to lysosomes. Under normal conditions, lipids from these lipoproteins are metabolized and do not accumulate in lysosomes. In the atherosclerotic foam cell, this normal metabolism is inhibited so that cholesterol and cholesteryl esters accumulate in lysosomes. Studies of cultured cells incubated with modified lipoproteins suggests this abnormal metabolism occurs in two steps. Initially, hydrolysis of lipoprotein cholesteryl esters occurs normally, but the resultant free cholesterol cannot exit the lysosome. Further lysosomal cholesterol accumulation inhibits hydrolysis, producing a mixture of cholesterol and cholesteryl esters within swollen lysosomes. Various lipoprotein modifications can produce this lysosomal engorgement in vitro and it remains to be seen which modifications are most important in vivo.

  19. Screening and Optimization of Ligand Conjugates for Lysosomal Targeting

    Science.gov (United States)

    Meerovich, Igor; Koshkaryev, Alexander; Thekkedath, Ritesh; Torchilin, Vladimir P.

    2011-01-01

    The use of lysosome-targeted liposomes may significantly improve the delivery of therapeutic enzymes and chaperones into lysosomes for the treatment of lysosomal storage disorders. The aim of this research was to synthesize new potentially lysosomotropic ligands on a base of Neutral Red and rhodamine B and to study their ability to enhance specific lysosomal delivery of surface-modified liposomes loaded with a model compound, fluorescein isothiocyanate-dextran (FD). The delivery of these liposomes and their content to lysosomes in HeLa cells was investigated by confocal immunofluorescent microscopy, subcellular fractionation and flow cytometry. Confocal microscopy demonstrated that liposomes modified with derivatives of rhodamine B provide good rate of co-localization well the specific lysosomal markers. The comparison of fluorescence of FD in lysosomes isolated by subcellular fractionation also showed that the efficiency of lysosomal delivery of liposomal load by liposomes modified with some of synthesized ligands was significantly higher compared with plain liposomes. These results were additionally confirmed by the flow cytometry of the intact cells treated with liposomes loaded with with 5-dodecanoylaminofluorescein di-β-D-galactopyranoside, a specific substrate for the intralysosomal β-galactosidase, using a number of cell lines, including macrophages with induced phenotype of lysosomal enzyme deficiency; two of the synthesized ligands – rhodamine B DSPE-PEG2k-amide and 6-(3-(DSPE-PEG2k)-thioureido) rhodamine B – demonstrated enhanced lysosomal delivery, in some cases, higher than that for commercially available rhodamine B octadecyl ester, with the best results (the enhancement of the lysosomal delivery up to 75% greater in comparison to plain liposomes) shown for the cells with induced lysosomal enzyme deficiency phenotype. Use of liposomes modified with rhodamine B derivatives may be advantageous for the development of drug delivery systems for the

  20. 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.

  1. 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.

  2. Chinese hamster ovary cell lysosomes rapidly exchange contents

    OpenAIRE

    1987-01-01

    We have used cell fusion to address the question of whether macromolecules are rapidly exchanged between lysosomes. Donor cell lysosomes were labeled by the long-term internalization of the fluid- phase pinocytic markers, invertase (sucrase), Lucifer Yellow, FITC- conjugated dextran, or Texas red-conjugated dextran. Recipient cells contained lysosomes swollen by long-term internalization of dilute sucrose or marked by an overnight FITC-dextran uptake. Cells were incubated for 1 or 2 h in mark...

  3. Inhibition of macrophage phagosome-lysosome fusion by Salmonella typhimurium.

    OpenAIRE

    Buchmeier, N A; Heffron, F

    1991-01-01

    Salmonella typhimurium-infected macrophages were examined by electron microscopy to determine whether intracellular survival of S. typhimurium is associated with failure of bacteria containing phagosomes to fuse with secondary lysosomes. S. typhimurium 14028 actively inhibited phagosome-lysosome fusion and appeared to preferentially divide within unfused phagocytic vesicles. In comparison with Escherichia coli, S. typhimurium inhibited phagosome-lysosome fusion in peritoneal macrophages, J774...

  4. 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.

  5. 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

  6. Lysosomal Targeting with Stable and Sensitive Fluorescent Probes (Superior LysoProbes): Applications for Lysosome Labeling and Tracking during Apoptosis

    OpenAIRE

    Xin Chen; Yue Bi; Tianyang Wang; Pengfei Li; Xin Yan; Shanshan Hou; Catherine E. Bammert; Jingfang Ju; K. Michael Gibson; Pavan, William J.; Lanrong Bi

    2015-01-01

    Intracellular pH plays an important role in the response to cancer invasion. We have designed and synthesized a series of new fluorescent probes (Superior LysoProbes) with the capacity to label acidic organelles and monitor lysosomal pH. Unlike commercially available fluorescent dyes, Superior LysoProbes are lysosome-specific and are highly stable. The use of Superior LysoProbes facilitates the direct visualization of the lysosomal response to lobaplatin elicited in human chloangiocarcinoma (...

  7. Engaging the lysosomal compartment to combat B cell malignancies

    DEFF Research Database (Denmark)

    Gronbaek, K.; Jaattela, M.

    2009-01-01

    generation of therapeutic anti-CD20 mAbs. In this issue of the JCI, Ivanov and colleagues identify the lysosomal compartment as a target for type II mAbs (see the related article beginning on page 2143). These data encourage the further clinical development of type II mAbs as well as other lysosome...

  8. 溶酶体贮积病%Lysosomal storage disorders

    Institute of Scientific and Technical Information of China (English)

    Yong QU

    2006-01-01

    Lysosomal storage disorders (LSDs) are genetic defects caused by lysosomal hydrolase deficiencies. These deficiencies lead to substrate accumulation affecting cells, tissues and organs. Detecting abnormal compound excretion and deficient enzymes assist diagnosis of these disorders for treatment and prevention. This mini review summarizes clinical presentations and diagnostic workup of LSDs and updates the new development in the area.

  9. 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

  10. 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

    OpenAIRE

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

    2015-01-01

    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 lact...

  11. Lysosomal Dysfunction Caused by Cellular Accumulation of Silica Nanoparticles.

    Science.gov (United States)

    Schütz, Irene; Lopez-Hernandez, Tania; Gao, Qi; Puchkov, Dmytro; Jabs, Sabrina; Nordmeyer, Daniel; Schmudde, Madlen; Rühl, Eckart; Graf, Christina M; Haucke, Volker

    2016-07-01

    Nanoparticles (NPs) are widely used as components of drugs or cosmetics and hold great promise for biomedicine, yet their effects on cell physiology remain poorly understood. Here we demonstrate that clathrin-independent dynamin 2-mediated caveolar uptake of surface-functionalized silica nanoparticles (SiNPs) impairs cell viability due to lysosomal dysfunction. We show that internalized SiNPs accumulate in lysosomes resulting in inhibition of autophagy-mediated protein turnover and impaired degradation of internalized epidermal growth factor, whereas endosomal recycling proceeds unperturbed. This phenotype is caused by perturbed delivery of cargo via autophagosomes and late endosomes to SiNP-filled cathepsin B/L-containing lysosomes rather than elevated lysosomal pH or altered mTOR activity. Given the importance of autophagy and lysosomal protein degradation for cellular proteostasis and clearance of aggregated proteins, these results raise the question of beneficial use of NPs in biomedicine and beyond. PMID:27226546

  12. 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

  13. Homotypic Lysosome Fusion in Macrophages: Analysis Using an In Vitro Assay

    OpenAIRE

    Diane M Ward; Jonathan D Leslie; Kaplan, Jerry

    1997-01-01

    Lysosomes are dynamic structures capable of fusing with endosomes as well as other lysosomes. We examined the biochemical requirements for homotypic lysosome fusion in vitro using lysosomes obtained from rabbit alveolar macrophages or the cultured macrophage-like cell line, J774E. The in vitro assay measures the formation of a biotinylated HRP–avidin conjugate, in which biotinylated HRP and avidin were accumulated in lysosomes by receptor-mediated endocytosis. We determined that lysosome fusi...

  14. 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.

  15. 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.

  16. Lysosomal Storage Causes Cellular Dysfunction in Mucolipidosis II Skin Fibroblasts*

    Science.gov (United States)

    Otomo, Takanobu; Higaki, Katsumi; Nanba, Eiji; Ozono, Keiichi; Sakai, Norio

    2011-01-01

    Mucolipidosis II (ML-II) is a fatal inherited metabolic disease caused by deficiency of GlcNAc-phosphotransferase, which plays a role in generating the mannose 6-phosphate recognition marker on lysosomal enzymes. In ML-II, many lysosomal acid hydrolases are mistargeted out of cells, and lysosomes become filled with undigested substrates, which explains inclusion cell disease as an alternative name for this disease. In this study, we revealed various cellular phenotypes in ML-II skin fibroblasts. We quantitated phospholipid and cholesterol within cells and showed ∼2-fold accumulation in ML-II as compared with normal cells. Lysosomal pH of ML-II cells was higher than that of normal cells (5.29 ± 0.08 versus 4.79 ± 0.10, p < 0.001). The proliferated lysosomes in ML-II cells were accumulated ∼3-fold in amount as compared with normal cells. Intracellular logistics including endocytosis and mannose 6-phosphate receptor recycling were impaired in ML-II cells. To confirm whether these ML-II cellular phenotypes derive from deficient lysosomal acid hydrolases within lysosomes, we performed supplementation of lysosomal enzymes using a partially purified total enzyme mixture, which was derived from the conditioned culture medium of normal skin fibroblasts after NH4Cl treatment. This supplementation corrected all of the previously described ML-II phenotypes. In addition, the autophagic and mitochondrial impairment that we have previously reported improved, and inclusion bodies disappeared on electron micrography following total lysosomal enzyme supplementation. Our results indicate that various cellular phenotypes in ML-II are caused by the deficiency of many lysosomal enzymes and massive accumulation of undigested substrates. PMID:21846724

  17. Cyclodextrin induces calcium-dependent lysosomal exocytosis.

    Directory of Open Access Journals (Sweden)

    Fannie W Chen

    Full Text Available Cyclodextrins (CDs have long been used to manipulate cellular cholesterol levels both in vitro and in vivo, but their direct effects at a cellular level are not well characterized. Recently, CDs have garnered much interest because of their ability to clear stored cholesterol from Niemann Pick Type C (NPC cells and markedly prolong the life of NPC1 disease mice. Here, we investigate the hypothesis that treatment with 2-hydroxypropyl- β-cyclodextrin (HPB-CD stimulates lysosomal exocytosis in a calcium-enhanced manner. We propose that this exocytosis is the mechanism by which HPB-CD ameliorates the endolysosomal cholesterol storage phenotype in NPC cells. These findings have significant implications for the use of HPB-CD in biochemical assays and data interpretation as well as for their use for the treatment for NPC and other disorders.

  18. Hyperamylasemia following cardiopulmonary bypass.

    Science.gov (United States)

    Chang, H; Chung, Y T; Wu, G J; Hwang, F Y; Chen, K T; Peng, W L; Hung, C R

    1992-01-01

    In order to study the occurrence of postbypass hyperamylasemia, 75 patients undergoing cardiopulmonary bypass (CPB) were studied from March 1989 to January 1990. There were 49 males and 26 females. Among them, 27 had congenital heart disease, 30 had valvular disease, and 18 had coronary artery disease. There were 27 patients with at least one elevated serum amylase sample after operation. Thus, the overall incidence of hyperamylasemia was 36%. As compared with the preoperative data (1.3%), there was a statistically significant difference in the occurrence of hyperamylasemia (p less than 0.05). Three patients had overt clinical pancreatitis postoperatively. There was no positive correlation between the serum amylase level and the occurrence of pancreatitis (p greater than 0.05). Forty-two cases had a significant elevation of the amylase creatinine clearance ratio (ACCR) after CPB. However, there was no significant difference between the groups with pulsatile and nonpulsatile CPB (p greater than 0.05). Three patients (4%) died in our series. The causes of death were heart failure in two and fulminant pancreatitis associated with low cardiac output in one. Although our experience in dealing with pancreatitis improved survival, mortality was still high (33.3%) in our series. Nevertheless, there was no apparent correlation between mortality and postbypass hyperamylasemia (p greater than 0.05). Logistic regression analysis was used to analyze the risk factors of the occurrence of hyperamylasemia, and the analysis revealed that patients with coronary artery disease were susceptible to postbypass hyperamylasemia. Our studies indicate that the use of total serum amylase or ACCR to monitor for the occurrence of pancreatitis in postbypass patients is inadequate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1377742

  19. Presence of detergent-resistant microdomains in lysosomal membranes.

    Science.gov (United States)

    Taute, Antje; Wätzig, Kristin; Simons, Brigitte; Lohaus, Christiane; Meyer, Helmut; Hasilik, Andrej

    2002-10-18

    We examined the association of acetyl-CoA:alpha-glucosaminide N-acetyltransferase, a lysosomal enzyme participating in the degradation of heparan sulfate with other components of the lysosomal membrane. We prepared lysosomal membranes from human placenta and treated them with zwitterionic and non-ionic detergents. Membrane proteins were solubilized either in the presence of CHAPS at room temperature or of Triton X-100 at 4 degrees C. The CHAPS-containing extract was subjected to gel filtration in a column with the nominal size exclusion of 0.6 MDa. Under these conditions the enzyme fractionated near the void volume. To examine the association of the enzyme with detergent-resistant lipid microdomains, the extract that had been prepared with Triton X-100 was subjected to flotation in a density gradient medium. After centrifugation, a major portion of the activity of the acetyltransferase was found at the top of the gradient along with the bulk of alkaline phosphatase. Alkaline phosphatase is a glycosylphosphatidylinositol-anchored protein; possibly a contaminant in the lysosomal fraction originating from the plasma membrane and adventitiously an internal control for the flotation in the gradient. In contrast, acetyltransferase is a genuine lysosomal protein that obligatorily spans the membrane since it transfers acetyl residues from acetyl-CoA in cytosol to glucosaminyl residues in heparan sulfate fragments in the lysosomal matrix. To our knowledge this is the first report on association of a lysosomal membrane protein with detergent-resistant membrane microdomains or rafts. PMID:12379211

  20. 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.

  1. 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...... decreased survival rate was found in diabetics (p bypass technique very useful in the treatment of critical ischaemia of the lower limb in diabetic patients. The overall results in diabetic patients, whether insulin-dependent or not, were equal to those in non...

  2. 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...

  3. Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass

    DEFF Research Database (Denmark)

    Christiansen, Claus Behrend; Berg, Ronan M G; Plovsing, Ronni;

    2016-01-01

    Background Cerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (d...

  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. 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...

  6. 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....

  7. 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.

  8. 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.

  9. Interventions in Infrainguinal Bypass Grafts

    International Nuclear Information System (INIS)

    The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft

  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. A Lysosome-Targeting AIEgen for Autophagy Visualization.

    Science.gov (United States)

    Leung, Chris Wai Tung; Wang, Zhiming; Zhao, Engui; Hong, Yuning; Chen, Sijie; Kwok, Ryan Tsz Kin; Leung, Anakin Chun Sing; Wen, Rongsen; Li, Bingshi; Lam, Jacky Wing Yip; Tang, Ben Zhong

    2016-02-18

    In this work, a morpholine-functionalized aggregation-induced emission luminogen (AIEgen), AIE-LysoY, is reported for lysosomal imaging and autophagy visualization. To attain outstanding imaging contrast, AIE-LysoY is equipped with excited state intramolecular proton transfer (ESIPT) characteristic. AIE-LysoY provides a new platform for lysosome visualization with good biocompatibility, large Stokes shift, superior signal-to-noise ratio, and high photostability. PMID:26688031

  12. 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.

  13. Lysosomes from rabbit type II cells catabolize surfactant lipids.

    Science.gov (United States)

    Rider, E D; Ikegami, M; Pinkerton, K E; Peake, J L; Jobe, A H

    2000-01-01

    The role of a lysosome fraction from rabbit type II cells in surfactant dipalmitoylphosphatidylcholine (DPPC) catabolism was investigated in vivo using radiolabeled DPPC and dihexadecylphosphatidylcholine (1, 2-dihexadecyl-sn-glycero-3-phosphocholine; DEPC), a phospholipase A(1)- and A(2)-resistant analog of DPPC. Freshly isolated type II cells were gently disrupted by shearing, and lysosomes were isolated with Percoll density gradients (density range 1.0591-1.1457 g/ml). The lysosome fractions were relatively free of contaminating organelles as determined by electron microscopy and organelle marker enzymes. After intratracheal injection of rabbits with [(3)H]DPPC and [(14)C]DEPC associated with a trace amount of natural rabbit surfactant, the degradation-resistant DEPC accumulated 16-fold compared with DPPC in lysosome fractions at 15 h. Lysosomes can be isolated from freshly isolated type II cells, and lysosomes from type II cells are the primary catabolic organelle for alveolar surfactant DPPC following reuptake by type II cells in vivo. PMID:10645892

  14. 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.

  15. Glucosamine-Bound Near-Infrared Fluorescent Probes with Lysosomal Specificity for Breast Tumor Imaging1

    OpenAIRE

    Li, Cong; Greenwood, Tiffany R; Glunde, Kristine

    2008-01-01

    Noninvasive imaging of lysosomes will be useful 1) to elucidate the role of lysosomal parameters in cancer, 2) to diagnose malignant lesions, and 3) to evaluate future lysosome-targeted anticancer therapies. Lysosome-specific labeling of glucosamine-bound near-infrared (NIR) fluorescent probes, IR-1 and IR-2, but not control probe IR-15 without the glucosamine moiety, was observed by fluorescence microscopy in human breast epithelial cell lines. Lysosome labeling and tumor specificity of thes...

  16. Spinster is required for autophagic lysosome reformation and mTOR reactivation following starvation

    OpenAIRE

    Rong, Yueguang; McPhee, Christina K; Deng, Shuangshen; Huang, Lei; Chen, Lilian; Liu, Mei; Tracy, Kirsten; Baehrecke, Eric H.; Yu, Li; Lenardo, Michael J.

    2011-01-01

    Autophagy is a conserved cellular process to degrade and recycle cytoplasmic components. During autophagy, lysosomes fuse with an autophagosome to form an autolysosome. Sequestered components are degraded by lysosomal hydrolases and presumably released into the cytosol by lysosomal efflux permeases. Following starvation-induced autophagy, lysosome homeostasis is restored by autophagic lysosome reformation (ALR) requiring activation of the “target of rapamycin” (TOR) kinase. Spinster (Spin) en...

  17. Glucosamine-Bound Near-Infrared Fluorescent Probes with Lysosomal Specificity for Breast Tumor Imaging

    OpenAIRE

    Cong Li; Greenwood, Tiffany R; Kristine Glunde

    2008-01-01

    Noninvasive imaging of lysosomes will be useful 1) to elucidate the role of lysosomal parameters in cancer, 2) to diagnose malignant lesions, and 3) to evaluate future lysosome-targeted anticancer therapies. Lysosome-specific labeling of glucosamine-bound near-infrared (NIR) fluorescent probes, IR-1 and IR-2, but not control probe IR-15 without the glucosamine moiety, was observed by fluorescence microscopy in human breast epithelial cell lines. Lysosome labeling and tumor specificity of thes...

  18. Bypass materials in vascular surgery

    Directory of Open Access Journals (Sweden)

    Willich, Stephan N.

    2006-03-01

    Full Text Available 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

  19. Mini cardiopulmonary bypass: Anesthetic considerations

    OpenAIRE

    Alsatli, Raed A.

    2012-01-01

    This review article is going to elaborate on the description, components, and advantages of mini-cardiopulmonary bypass (mini-CPB), with special reference to the anesthetic management and fast track anesthesia with mini-CPB. There are several clinical advantages of mini-CPB like, reduced inflammatory reaction to the pump, reduced need for allogenic blood transfusion and lower incidence of postoperative neurological complications. There are certainly important points that have to be considered...

  20. LAMP proteins are required for fusion of lysosomes with phagosomes.

    Science.gov (United States)

    Huynh, Kassidy K; Eskelinen, Eeva-Liisa; Scott, Cameron C; Malevanets, Anatoly; Saftig, Paul; Grinstein, Sergio

    2007-01-24

    Lysosome-associated membrane proteins 1 and 2 (LAMP-1 and LAMP-2) are delivered to phagosomes during the maturation process. We used cells from LAMP-deficient mice to analyze the role of these proteins in phagosome maturation. Macrophages from LAMP-1- or LAMP-2-deficient mice displayed normal fusion of lysosomes with phagosomes. Because ablation of both the lamp-1 and lamp-2 genes yields an embryonic-lethal phenotype, we were unable to study macrophages from double knockouts. Instead, we reconstituted phagocytosis in murine embryonic fibroblasts (MEFs) by transfection of FcgammaIIA receptors. Phagosomes formed by FcgammaIIA-transfected MEFs obtained from LAMP-1- or LAMP-2- deficient mice acquired lysosomal markers. Remarkably, although FcgammaIIA-transfected MEFs from double-deficient mice ingested particles normally, phagosomal maturation was arrested. LAMP-1 and LAMP-2 double-deficient phagosomes acquired Rab5 and accumulated phosphatidylinositol 3-phosphate, but failed to recruit Rab7 and did not fuse with lysosomes. We attribute the deficiency to impaired organellar motility along microtubules. Time-lapse cinematography revealed that late endosomes/lysosomes as well as phagosomes lacking LAMP-1 and LAMP-2 had reduced ability to move toward the microtubule-organizing center, likely precluding their interaction with each other. PMID:17245426

  1. Epicardial ultrasound in coronary artery bypass surgery

    OpenAIRE

    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 surgeon may face several intraoperative difficulties: 1. Localization of the target coronary artery for bypass grafting. 2. Selection of the optimal anastomotic site on the target coronary artery. 3. Asses...

  2. Genetic Coding Variant in GPR65 Alters Lysosomal pH and Links Lysosomal Dysfunction with Colitis Risk.

    Science.gov (United States)

    Lassen, Kara G; McKenzie, Craig I; Mari, Muriel; Murano, Tatsuro; Begun, Jakob; Baxt, Leigh A; Goel, Gautam; Villablanca, Eduardo J; Kuo, Szu-Yu; Huang, Hailiang; Macia, Laurence; Bhan, Atul K; Batten, Marcel; Daly, Mark J; Reggiori, Fulvio; Mackay, Charles R; Xavier, Ramnik J

    2016-06-21

    Although numerous polymorphisms have been associated with inflammatory bowel disease (IBD), identifying the function of these genetic factors has proved challenging. Here we identified a role for nine genes in IBD susceptibility loci in antibacterial autophagy and characterized a role for one of these genes, GPR65, in maintaining lysosome function. Mice lacking Gpr65, a proton-sensing G protein-coupled receptor, showed increased susceptibly to bacteria-induced colitis. Epithelial cells and macrophages lacking GPR65 exhibited impaired clearance of intracellular bacteria and accumulation of aberrant lysosomes. Similarly, IBD patient cells and epithelial cells expressing an IBD-associated missense variant, GPR65 I231L, displayed aberrant lysosomal pH resulting in lysosomal dysfunction, impaired bacterial restriction, and altered lipid droplet formation. The GPR65 I231L polymorphism was sufficient to confer decreased GPR65 signaling. Collectively, these data establish a role for GPR65 in IBD susceptibility and identify lysosomal dysfunction as a potentially causative element in IBD pathogenesis with effects on cellular homeostasis and defense. PMID:27287411

  3. Quantitative modeling of selective lysosomal targeting for drug design

    DEFF Research Database (Denmark)

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

    2008-01-01

    the diffusion of neutral and ionic molecules across biomembranes, protonation to mono- or bivalent ions, adsorption to lipids, and electrical attraction or repulsion. Based on simulation results, high and selective accumulation in lysosomes was found for weak mono- and bivalent bases with intermediate to high...... predicted by the model and three were close. Five of the antimalarial drugs were lipophilic weak dibasic compounds. The predicted optimum properties for a selective accumulation of weak bivalent bases in lysosomes are consistent with experimental values and are more accurate than any prior calculation...

  4. 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

    2016-01-01

    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. PMID:27213518

  5. A Rab3a-dependent complex essential for lysosome positioning and plasma membrane repair.

    Science.gov (United States)

    Encarnação, Marisa; Espada, Lília; Escrevente, Cristina; Mateus, Denisa; Ramalho, José; Michelet, Xavier; Santarino, Inês; Hsu, Victor W; Brenner, Michael B; Barral, Duarte; Vieira, Otília V

    2016-06-20

    Lysosome exocytosis plays a major role in resealing plasma membrane (PM) disruptions. This process involves two sequential steps. First, lysosomes are recruited to the periphery of the cell and then fuse with the damaged PM. However, the trafficking molecular machinery involved in lysosome exocytosis and PM repair (PMR) is poorly understood. We performed a systematic screen of the human Rab family to identify Rabs required for lysosome exocytosis and PMR. Rab3a, which partially localizes to peripheral lysosomes, was one of the most robust hits. Silencing of Rab3a or its effector, synaptotagmin-like protein 4a (Slp4-a), leads to the collapse of lysosomes to the perinuclear region and inhibition of PMR. Importantly, we have also identified a new Rab3 effector, nonmuscle myosin heavy chain IIA, as part of the complex formed by Rab3a and Slp4-a that is responsible for lysosome positioning at the cell periphery and lysosome exocytosis. PMID:27325790

  6. 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.

  7. Clinical, biochemical and genetic heterogeneity in lysosomal storage diseases

    NARCIS (Netherlands)

    A.J.J. Reuser (Arnold)

    1977-01-01

    textabstractThe history of lysosomal storage diseases dates back to the end of the last century when the first clinical reports appeared of patients suffering from these genetic, metabolic disorders (Tay, 1881; Gaucher, 1882; Sachs, 1887; Fabry, 1898). About seventy years wouid pass before the term

  8. 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

  9. Structure of human saposin A at lysosomal pH

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Chris H.; Read, Randy J.; Deane, Janet E., E-mail: jed55@cam.ac.uk [University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY (United Kingdom)

    2015-06-27

    A 1.8 Å resolution structure of the sphingolipid activator protein saposin A has been determined at pH 4.8, the physiologically relevant lysosomal pH for hydrolase enzyme activation and lipid-transfer activity. The saposins are essential cofactors for the normal lysosomal degradation of complex glycosphingolipids by acid hydrolase enzymes; defects in either saposin or hydrolase function lead to severe metabolic diseases. Saposin A (SapA) activates the enzyme β-galactocerebrosidase (GALC), which catalyzes the breakdown of β-d-galactocerebroside, the principal lipid component of myelin. SapA is known to bind lipids and detergents in a pH-dependent manner; this is accompanied by a striking transition from a ‘closed’ to an ‘open’ conformation. However, previous structures were determined at non-lysosomal pH. This work describes a 1.8 Å resolution X-ray crystal structure determined at the physiologically relevant lysosomal pH 4.8. In the absence of lipid or detergent at pH 4.8, SapA is observeed to adopt a conformation closely resembling the previously determined ‘closed’ conformation, showing that pH alone is not sufficient for the transition to the ‘open’ conformation. Structural alignments reveal small conformational changes, highlighting regions of flexibility.

  10. 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,…

  11. 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

  12. Atrial fibrillation post cardiac bypass surgery

    OpenAIRE

    Mostafa, Ashraf; EL-Haddad, Mohamed A.; Shenoy, Maithili; Tuliani, Tushar

    2012-01-01

    Atrial fibrillation occurs in 5-40% patients after coronary artery bypass graft surgery. Atrial fibrillation increases mortality and morbidity in the post-operative period. We sought to conduct a comprehensive review of literature focusing on pathophysiology, risk factors, prevention and treatment of post coronary artery bypass graft atrial fibrillation.

  13. 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

  14. 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

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

    OpenAIRE

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

    2015-01-01

    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 ...

  16. Lysosomal Exocytosis in Schwann Cells Contributes to Axon Remyelination

    Institute of Scientific and Technical Information of China (English)

    GANG CHEN; ZHIJUN ZHANG; ZHONGYA WEI; QIONG CHENG; XIA LI; WEI LI; SHUMIN DUAN; XIAOSONG GU

    2012-01-01

    Myelin biogenesis is a complex process involving coordinated exocytosis, endocytosis, mRNA transport, and cytoskeletal dynamics. Although abnormalities of myelin are common in lysosomal storage diseases, our understanding of the role of lysosomes in the formation and maintenance of myelin is still limited. Here, we show that late endosomes/lysosomes in Schwann cells contain abundant myelin protein P0, which accounts for over half the total protein of compact myelin in the peripheral nervous system and exhibit Ca2+-dependent exocytosis in response to various stimuli. Downregulation of Rab27a, a small GTPase required for the trafficking of the secretory lysosomes to the plasma membrane, largely blocked lysosomal exocytosis in Schwann cells and reduced the remyelination of regenerated sciatic nerve. These findings highlight a novel role for lysosomes in Schwann cells and suggest that the regulated lysosome exocytosis in Schwann cells may have important physiological and pathological significance in the peripheral nervous%髓鞘形成是一个包括协同性的胞吐、内吞、mRNA转运和细胞骨架的动态变化的复杂过程.尽管髓鞘的异常在溶酶体贮积症中很常见,但对溶酶体在髓鞘形成和维持中所扮演的角色仍不清楚.本文发现Schwann细胞中的晚期内涵体/溶酶体包含大量的髓鞘蛋白P0,含量占超过一半的外周神经系统中的致密髓鞘的总蛋白并且在不同的刺激下表现出Ca2+依赖性的胞吐作用.Rab27a(一种将分泌溶酶体运输至细胞膜的小GTP酶)下调,极大地阻碍了Schwann细胞中的溶酶体胞吐作用,减少了再生坐骨神经的髓鞘形成.这些发现强调了Schwann细胞中溶酶体的新角色,提示调节Schwann细胞中的溶酶体胞吐作用在外周神经系统中有很重要的生理和病理意义.

  17. 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

  18. 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 i...

  19. Enrichment and analysis of secretory lysosomes from lymphocyte populations

    Directory of Open Access Journals (Sweden)

    Leippe Matthias

    2009-07-01

    Full Text Available Abstract Background In specialized cells, such as mast cells, macrophages, T lymphocytes and Natural Killer cells in the immune system and for instance melanocytes in the skin, secretory lysosomes (SL have evolved as bifunctional organelles that combine degradative and secretory properties. Mutations in lysosomal storage, transport or sorting molecules are associated with severe immunodeficiencies, autoimmunity and (partial albinism. In order to analyze the function and content of secretory lysosomes in different cell populations, an efficient enrichment of these organelles is mandatory. Results Based on a combination of differential and density gradient centrifugation steps, we provide a protocol to enrich intact SL from expanded hematopoietic cells, here T lymphocytes and Natural Killer cells. Individual fractions were initially characterized by Western blotting using antibodies against an array of marker proteins for intracellular compartments. As indicated by the presence of LAMP-3 (CD63 and FasL (CD178, we obtained a selective enrichment of SL in one of the resulting organelle fractions. The robustness and reproducibility of the applied separation protocol was examined by a high-resolution proteome analysis of individual SL preparations of different donors by 2D difference gel electrophoresis (2D-DIGE. Conclusion The provided protocol is readily applicable to enrich and isolate intact secretory vesicles from individual cell populations. It can be used to compare SL of normal and transformed cell lines or primary cell populations from healthy donors and patients with lysosomal storage or transport diseases, or from corresponding mutant mice. A subsequent proteome analysis allows the characterization of molecules involved in lysosomal maturation and cytotoxic effector function at high-resolution.

  20. 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. PMID:26682800

  1. Cardiopulmonary Bypass and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Mustafa Zakkar

    2015-01-01

    Full Text Available The development of the cardiopulmonary bypass (CPB revolutionized cardiac surgery and contributed immensely to improved patients outcomes. CPB is associated with the activation of different coagulation, proinflammatory, survival cascades and altered redox state. Haemolysis, ischaemia, and perfusion injury and neutrophils activation during CPB play a pivotal role in oxidative stress and the associated activation of proinflammatory and proapoptotic signalling pathways which can affect the function and recovery of multiple organs such as the myocardium, lungs, and kidneys and influence clinical outcomes. The administration of agents with antioxidant properties during surgery either intravenously or in the cardioplegia solution may reduce ROS burst and oxidative stress during CPB. Alternatively, the use of modified circuits such as minibypass can modify both proinflammatory responses and oxidative stress.

  2. 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. PMID:25976368

  3. Secondary coolant purification system with demineralizer bypass

    International Nuclear Information System (INIS)

    Apparatus and method are provided for a nuclear stream supply system for adequately controlling the chemistry of the secondary coolant. The invention includes means for the addition of volatile chemicals, a full flow condensate demineralizer, continuous blowdown capability, radiation detection means, a condensate demineralizer bypass line, and an auxiliary demineralizer bypass line, and an auxiliary demineralizer sized to handle full blowdown flow. The auxiliary demineralizer is cut into the system and the steam generator feedwater flow is bypassed around the full flow condensate demineralizer whenever radioactivity is detected in the secondary coolant

  4. 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...

  5. 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.

  6. A genetic model with specifically impaired autophagosome–lysosome fusion

    OpenAIRE

    Takáts, Szabolcs; Juhász, Gábor

    2013-01-01

    Yeast studies identified the evolutionarily conserved core ATG genes responsible for autophagosome formation. However, the SNARE-dependent machinery involved in autophagosome fusion with the vacuole in yeast is not conserved. We recently reported that the SNARE complex consisting of Syx17 (Syntaxin 17), ubisnap (SNAP-29) and Vamp7 is required for the fusion of autophagosomes with late endosomes and lysosomes in Drosophila. Syx17 mutant flies are viable but exhibit neuronal dysfunction, locomo...

  7. 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...

  8. Role of alveolar macrophage lysosomes in metal detoxification.

    Science.gov (United States)

    Berry, J P; Zhang, L; Galle, P; Ansoborlo, E; Hengé-Napoli, M H; Donnadieu-Claraz, M

    1997-02-15

    The intracellular behaviour of different toxic mineral elements inhaled as soluble aerosols or as insoluble particles was studied in the rat by electron microscopy, electron probe microanalysis, and electron microdiffraction. This study showed that, after inhalation, aerosols of soluble elements like cerous chloride, chromic chloride, uranyl nitrate, and aluminium chloride, are concentrated in the lysosomes of alveolar macrophages and are precipitated in the lysosomes in the form of insoluble phosphate, probably due to the activity of acid phosphatase (intralysosomial enzyme). Also, after inhalation of crystalline particles that are insoluble or poorly soluble in water such as the illites (phyllosilicates), ceric oxides (opaline), and industrial uranium oxides (U3O8), the small crystals are captured by the alveolar macrophage lysosomes and transformed over time into an amorphous form. This structural transformation is associated with changes in the chemical nature of particles inhaled in the oxide form. Microanalysis of amorphous deposits observed after inhalation of uranium or ceric oxides has shown that they contain high concentrations of phosphorus associated with the initial elements cerium and uranium. These different processes tend to limit the diffusion of these toxic elements within the organism, whether they are inhaled in soluble form or not. PMID:9140931

  9. 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.

  10. 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

  11. The Use of Lysosomotropic Dyes to Exclude Lysosomal Membrane Permeabilization.

    Science.gov (United States)

    Repnik, Urška; Česen, Maruša Hafner; Turk, Boris

    2016-01-01

    Progressive lowering of pH is characteristic for the endocytic pathway and enables efficient degradation of molecules by hydrolytic enzymes at its distal end. The existence of the proton gradient over the endosomal/lysosomal membranes depends on the action of the vacuolar ATPase (v-ATPase). During lysosomal membrane permeabilization (LMP), protons leak through the destabilized membrane, resulting in loss of the pH gradient. Here, we present a protocol showing how this effect can be detected by staining cells with lysosomotropic dyes, which accumulate in acidic organelles after protonation. During LMP, cells lose the ability to retain these dyes and therefore appear pale. Among the most commonly used lysosomotropic dyes are LysoTracker reagents and acridine orange. Cells can be analyzed with a fluorescence microscope; however, flow-cytometric analysis enables fast, objective, and reliable evaluation of differences between samples. Advantages of the technique include the fact that sample preparation is relatively simple and can be scaled-up to test several different compounds or conditions. However, as we will discuss, cells treated with v-ATPase inhibitors also lose the pH gradient across lysosomal membranes and cannot be stained with lysosomotropic dyes, although this is not accompanied by LMP. Therefore, merely observing loss of staining is not in itself a proof of LMP. PMID:27140914

  12. 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.

  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. Phrenic Nerve Injury during Coronary Artery Bypass

    OpenAIRE

    Guinn, Gene A.; Beall, Arthur C.; Lamki, Neela; Heibig, Jacques; Thornby, John

    1990-01-01

    After coronary artery bypass, some patients have diaphragmatic elevation, usually on the left side. To test our hypothesis that this phenomenon is due to phrenic nerve injury resulting from either 1) dissection of the proximal portion of the left internal mammary artery or 2) topical cooling of the heart with icy slush, we performed the following 2-part study. First, we reviewed our hospital records of 99 coronary artery bypass patients, 55 of whom had received left internal mammary artery gr...

  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. 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.

  18. Targeting of lysosomes by liposomes modified with octadecyl-rhodamine B

    Science.gov (United States)

    Koshkaryev, Alexander; Thekkedath, Ritesh; Pagano, Cinzia; Meerovich, Igor; Torchilin, Vladimir P.

    2014-01-01

    The use of lysosome-targeted liposomes may significantly improve a delivery of therapeutic enzymes into lysosomes for the treatment of lysosome-associated diseases. The aim of this research was to achieve a specific intracellular targeting of lysosomes, by using liposomes modified with the lysosomotropic octadecyl-rhodamine B (RhB) and loaded with a model compound, fluorescein isothiocyanate (FITC)–dextran (FD). Plain and RhB-modified liposomes were prepared by hydration of lipid films and loaded with FD or with 5-dodecanoylaminofluorescein di-β-D-galactopyranoside (C12FDG), a specific substrate for the intralysosomal β-galactosidase. The delivery of these liposomes and their content to lysosomes in HeLa cells was investigated by confocal microscopy, flow cytometry, and subcellular fractionation. Confocal microscopy demonstrated that RhB-liposomes co-localize well with the specific lysosomal markers, unlike plain liposomes. The comparison of the FITC fluorescence of the lysosomes isolated by subcellular fractionation also showed that the efficiency of FD delivery into lysosomes by RhB-modified liposomes was significantly higher compared with plain liposomes. These results were additionally confirmed by the flow cytometry of the intact cells treated with C12FDG-loaded liposomes that also demonstrated increased lysosomal targeting by RhB-modified liposomes. The modification of the liposomal surface with a lysosomotropic ligand, such as octadecyl-RhB, can significantly increase the delivery of liposomal loads to lysosomes. PMID:21275828

  19. 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

    2016-01-01

    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 Ca2+-dependent mechanism independent of mTOR. Exogenous oxidants or increasing mitochondrial ROS levels directly and specifically activate lysosomal TRPML1 channels, inducing lysosomal Ca2+ 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. PMID:27357649

  20. 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

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

    DEFF Research Database (Denmark)

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

    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...... 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...

  2. "Orpheus" cardiopulmonary bypass simulation system.

    Science.gov (United States)

    Morris, Richard W; Pybus, David A

    2007-12-01

    In this paper we describe a high-fidelity perfusion simulation system intended for use in the training and continuing education of perfusionists. The system comprises a hydraulic simulator, an electronic interface unit and a controlling computer with associated real-time computer models. It is designed for use within an actual operating theatre, or within a specialized simulation facility. The hydraulic simulator can be positioned on an operating table and physically connected to the circuit of the institutional heart-lung machine. The institutional monitoring system is used to display the arterial and central venous pressures, the ECG and the nasopharyngeal temperature using appropriate connections. The simulator is able to reproduce the full spectrum of normal and abnormal events that may present during the course of cardiopulmonary bypass. The system incorporates a sophisticated blood gas model that accurately predicts the behavior of a modern, hollow-fiber oxygenator. Output from this model is displayed in the manner of an in-line blood gas electrode and is updated every 500 msecs. The perfusionist is able to administer a wide variety of drugs during a simulation session including: vasoconstrictors (metaraminol, epinephrine and phenylephrine), a vasodilator (sodium nitroprusside), chronotropes (epinephrine and atropine), an inotrope (epinephrine) and modifiers of coagulation (heparin and protamine). Each drug has a pharmacokinetic profile based on a three-compartment model plus an effect compartment. The simulation system has potential roles in the skill training of perfusionists, the development of crisis management protocols, the certification and accreditation of perfusionists and the evaluation of new perfusion equipment and/or techniques. PMID:18293807

  3. Virulent Brucella abortus Prevents Lysosome Fusion and Is Distributed within Autophagosome-Like Compartments

    OpenAIRE

    Pizarro-Cerdá, Javier; Moreno, Edgardo; Sanguedolce, Veronique; Mege, Jean-Louis; Gorvel, Jean-Pierre

    1998-01-01

    Virulent and attenuated Brucella abortus strains attach to and penetrate nonprofessional phagocytic HeLa cells. Compared to pathogenic Brucella, the attenuated strain 19 hardly replicates within cells. The majority of the strain 19 bacteria colocalized with the lysosome marker cathepsin D, suggesting that Brucella-containing phagosomes had fused with lysosomes, in which they may have degraded. The virulent bacteria prevented lysosome-phagosome fusion and were found distributed in the perinucl...

  4. Phagosome-lysosome fusion is a calcium-independent event in macrophages

    OpenAIRE

    1996-01-01

    Phagosome-lysosome membrane fusion is a highly regulated event that is essential for intracellular killing of microorganisms. Functionally, it represents a form of polarized regulated secretion, which is classically dependent on increases in intracellular ionized calcium ([Ca2+]i). Indeed, increases in [Ca2+]i are essential for phagosome- granule (lysosome) fusion in neutrophils and for lysosomal fusion events that mediate host cell invasion by Trypanosoma cruzi trypomastigotes. Since several...

  5. FLCN Maintains the Leucine Level in Lysosome to Stimulate mTORC1

    OpenAIRE

    Wu, Xiaochun; Zhao, Lingling; Chen, Zhi; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

    2016-01-01

    The intracellular amino acid pool within lysosome is a signal that stimulates the nutrient-sensing mTORC1 signalling pathway. The signal transduction cascade has garnered much attention, but little is known about the sequestration of the signalling molecules within the lysosome. Using human HEK293 cells as a model, we found that suppression of the BHD syndrome gene FLCN reduced the leucine level in lysosome, which correlated with decreased mTORC1 activity. Both consequences could be reversed ...

  6. 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....

  7. Deviant Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Ca2+ Signaling upon Lysosome Proliferation*

    OpenAIRE

    Dickinson, G. D.; Churchill, G. C.; Brailoiu, E; Patel, S.

    2010-01-01

    Accumulating evidence suggests that the endolysosomal system is a novel intracellular Ca2+ pool mobilized by the second messenger, nicotinic acid adenine dinucleotide phosphate (NAADP). Although lysosomes in neurons are known to proliferate in numerous neurodegenerative diseases and during the normal course of aging, little is known concerning the effect of lysosomal proliferation on Ca2+ homeostasis. Here, we induce proliferation of lysosomes in primary cultures of rat hippocampal neurons an...

  8. Role of lysosome rupture in controlling Nlrp3 signaling and necrotic cell death

    OpenAIRE

    Lima, Jr., Heriberto; Jacobson, Lee S.; Goldberg, Michael F.; Chandran, Kartik; Diaz-Griffero, Felipe; Lisanti, Michael P; Brojatsch, Jürgen

    2013-01-01

    The Nod-like receptor, Nlrp3, has been linked to inflammatory diseases and adjuvant-mediated immune responses. A wide array of structurally diverse agents does not interact directly with Nlrp3, but is thought to activate the Nlrp3 inflammasome by inducing a common upstream signal, such as lysosome rupture. To test the connection between lysosome integrity and Nlrp3 signaling, we analyzed inflammasome activation following stimulation of murine macrophages with lysosome-destabilizing agents and...

  9. Coordinated host responses during pyroptosis: caspase-1-dependent lysosome exocytosis and inflammatory cytokine maturation

    OpenAIRE

    Bergsbaken, Tessa; Fink, Susan L.; den Hartigh, Andreas B.; Loomis, Wendy P.; Cookson, Brad T.

    2011-01-01

    Activation of caspase-1 leads to pyroptosis, a program of cell death characterized by cell lysis and inflammatory cytokine release. Caspase-1 activation triggered by multiple NLRs (NLRC4, NLRP1b, or NLRP3) leads to loss of lysosomes via their fusion with the cell surface, or lysosome exocytosis. Active caspase-1 increased cellular membrane permeability and intracellular calcium levels, which facilitated lysosome exocytosis and release of host antimicrobial factors and microbial products. Lyso...

  10. Signals for the lysosome: a control center for cellular clearance and energy metabolism

    OpenAIRE

    Settembre, Carmine; Fraldi, Alessandro; Medina, Diego L.; Ballabio, Andrea

    2013-01-01

    For a long time lysosomes were considered merely to be cellular “incinerators” involved in the degradation and recycling of cellular waste. However, there is now compelling evidence indicating that lysosomes have a much broader function and that they are involved in fundamental processes such as secretion, plasma membrane repair, signaling and energy metabolism. Furthermore, the essential role of lysosomes in the autophagic pathway puts these organelles at the crossroads of several cellular p...

  11. Lysosomal-specific Cholesterol Reduction by Biocleavable Polyrotaxanes for Ameliorating Niemann-Pick Type C Disease

    OpenAIRE

    Atsushi Tamura; Nobuhiko Yui

    2014-01-01

    Niemann-Pick type C (NPC) disease is an autosomal recessive lysosomal trafficking disorder, in which the cholesterols are abnormally accumulated in lysosomes. Recently, the β-cyclodextrin (CD) derivatives are revealed to show therapeutic effect for NPC disease through the removal of accumulated cholesterols in lysosomes. Herein, to enhance the therapeutic effect and reduce the toxicity of β-CD derivatives, biocleavable Pluronic/β-CD-based polyrotaxanes (PRXs) bearing terminal disulfide linkag...

  12. Effect of glutamate on lysosomal membrane permeabilization in primary cultured cortical neurons

    OpenAIRE

    Yan, Min; Zhu, Wenbo; Zheng, Xiaoke; Li, Yuan; TANG, LIPENG; LU, BINGZHENG; Chen, WenLi; Qiu, Pengxin; Leng, Tiandong; Lin, Suizhen; Yan, Guangmei; Yin, Wei

    2016-01-01

    Glutamate is the principal neurotransmitter in the central nervous system. Glutamate-mediated excitotoxicity is the predominant cause of cerebral damage. Recent studies have shown that lysosomal membrane permeabilization (LMP) is involved in ischemia-associated neuronal death in non-human primates. This study was designed to investigate the effect of glutamate on lysosomal stability in primary cultured cortical neurons. Glutamate treatment for 30 min induced the permeabilization of lysosomal ...

  13. Imidazoacridinone-dependent lysosomal photodestruction: a pharmacological Trojan horse approach to eradicate multidrug-resistant cancers

    OpenAIRE

    Adar, Y.; M. ; Stark; Bram, E E; Nowak-Sliwinska, P.; Bergh, van den, H.; Szewczyk, G.; Sarna, T.; Skladanowski, A.; Griffioen, A W; Assaraf, Y.G.

    2012-01-01

    Multidrug resistance (MDR) remains a primary hindrance to curative cancer therapy. Thus, introduction of novel strategies to overcome MDR is of paramount therapeutic significance. Sequestration of chemotherapeutics in lysosomes is an established mechanism of drug resistance. Here, we show that MDR cells display a marked increase in lysosome number. We further demonstrate that imidazoacridinones (IAs), which are cytotoxic fluorochromes, undergo a dramatic compartmentalization in lysosomes beca...

  14. 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.

  15. 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.

  16. [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.

  17. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Science.gov (United States)

    ROBOT-ASSISTED MINIMALLY INVASIVE CORONARY ARTERY BYPASS SURGERY OPERATION PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 ... Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery operation. ...

  18. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Medline Plus

    Full Text Available ROBOT-ASSISTED MINIMALLY INVASIVE CORONARY ARTERY BYPASS SURGERY OPERATION PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 ... Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery operation. ...

  19. Coronary Artery Bypass Graft Surgery (Beyond the Basics)

    Science.gov (United States)

    ... for people with coronary heart disease is called "percutaneous coronary intervention" (PCI), or "stenting." This involves using a flexible ... artery disease: Coronary artery bypass graft surgery versus percutaneous coronary intervention Coronary artery bypass grafting in patients with cerebrovascular ...

  20. 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.

  1. Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results.

    Science.gov (United States)

    Mishra, Y; Mehta, Y; Kohli, V M; Kohli, V; Mairal, M; Mishra, A; Bapna, R K; Trehan, N

    1997-01-01

    From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary

  2. 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...

  3. Lysosome-targeted octadecyl-rhodamine B-liposomes enhance lysosomal accumulation of glucocerebrosidase in Gaucher’s cells in vitro

    Science.gov (United States)

    Thekkedath, Ritesh; Koshkaryev, Alexander; Torchilin, Vladimir P

    2013-01-01

    Aim We hypothesized that liposomes modified with lysosomotropic octadecyl-rhodamine B (Rh) and loaded with therapeutic glucocerebroside velaglucerase alfa (VPRIV™) will improve lysosomal delivery of the enzyme into Gaucher’s cells. Materials & methods Confocal microscopy and flow cytometry were used to evaluate the ability of Rh-modified liposomes loaded with VPRIV to improve the lysosomal targeting in monocyte-derived macrophages and Gaucher’s fibroblasts. Results Confocal microscopy demonstrated that Rh-modified liposomes localized primarily in the lysosomes. As confirmed by flow cytometry using specific substrate 5-(pentafluorobenzoylamino)fluorescein diglucoside, intralysosomal accumulation of VPRIV in the cells treated with Rh-modified liposomes was significantly increased (up to 68%) relative to the cells treated with plain liposomes or free VPRIV. Conclusion Rh-modified lysosomotropic liposomes can improve lysosomal accumulation of liposomal enzymes both in nonphagocytic Gaucher’s fibroblasts and phagocytic monocyte-derived macrophages. PMID:23199221

  4. 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...

  5. Outcomes after off-pump coronary bypass surgery

    NARCIS (Netherlands)

    Dijk, Diederik van

    2002-01-01

    The complications associated with in coronary artery bypass surgery (CABG) using cardiopulmonary bypass (CPB) have led to a renewed interest in coronary bypass surgery on the beating heart. The primary objective of the Octopus Study was to compare cognitive outcome between patients randomized to off

  6. 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...

  7. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  8. Taking Out TB–Lysosomal Trafficking and Mycobactericidal Ubiquitin-Derived Peptides

    OpenAIRE

    Purdy, Georgiana E.

    2011-01-01

    Tuberculosis remains a significant global health concern. The hallmark of Mycobacterium tuberculosis pathogenicity is its ability to infect resting macrophages and establish an intracellular niche. Activated and autophagic macrophages control mycobacterial infections through bactericidal mechanisms ranging from reactive oxygen and nitrogen intermediates to the delivery of the bacterium to the acidified, hydrolytically active lysosome. The mycobactericidal activity of the lysosome is due in pa...

  9. Taking out TB – A role for lysosomal ubiquitin-derived peptides

    OpenAIRE

    Georgiana ePurdy

    2011-01-01

    Tuberculosis remains a significant global health concern. The hallmark of Mycobacterium tuberculosis pathogenicity is its ability to infect resting macrophages and establish an intracellular niche. Activated and autophagic macrophages control mycobacterial infections through bactericidal mechanisms ranging from reactive oxygen and nitrogen intermediates to the delivery of the bacterium to the acidified, hydrolytically active lysosome. The mycobactericidal activity of the lysosome is due in pa...

  10. The FTLD risk factor TMEM106B and MAP6 control dendritic trafficking of lysosomes

    NARCIS (Netherlands)

    Schwenk, B.M.; Lang, C.M.; Hogl, S.; Tahirovic, S.; Orozco, D.; Rentzsch, K.; Lichtenthaler, S.F.; Hoogenraad, Casper; Capell, A.; Haass, C.; Edbauer, D.

    2014-01-01

    TMEM106B is a major risk factor for frontotemporal lobar degeneration with TDP‐43 pathology. TMEM106B localizes to lysosomes, but its function remains unclear. We show that TMEM106B knockdown in primary neurons affects lysosomal trafficking and blunts dendritic arborization. We identify microtubule‐

  11. Plasma Membrane Repair Is Regulated Extracellularly by Proteases Released from Lysosomes.

    Directory of Open Access Journals (Sweden)

    Thiago Castro-Gomes

    Full Text Available Eukaryotic cells rapidly repair wounds on their plasma membrane. Resealing is Ca(2+-dependent, and involves exocytosis of lysosomes followed by massive endocytosis. Extracellular activity of the lysosomal enzyme acid sphingomyelinase was previously shown to promote endocytosis and wound removal. However, whether lysosomal proteases released during cell injury participate in resealing is unknown. Here we show that lysosomal proteases regulate plasma membrane repair. Extracellular proteolysis is detected shortly after cell wounding, and inhibition of this process blocks repair. Conversely, surface protein degradation facilitates plasma membrane resealing. The abundant lysosomal cysteine proteases cathepsin B and L, known to proteolytically remodel the extracellular matrix, are rapidly released upon cell injury and are required for efficient plasma membrane repair. In contrast, inhibition of aspartyl proteases or RNAi-mediated silencing of the lysosomal aspartyl protease cathepsin D enhances resealing, an effect associated with the accumulation of active acid sphingomyelinase on the cell surface. Thus, secreted lysosomal cysteine proteases may promote repair by facilitating membrane access of lysosomal acid sphingomyelinase, which promotes wound removal and is subsequently downregulated extracellularly by a process involving cathepsin D.

  12. Plasma Membrane Repair Is Regulated Extracellularly by Proteases Released from Lysosomes.

    Science.gov (United States)

    Castro-Gomes, Thiago; Corrotte, Matthias; Tam, Christina; Andrews, Norma W

    2016-01-01

    Eukaryotic cells rapidly repair wounds on their plasma membrane. Resealing is Ca(2+)-dependent, and involves exocytosis of lysosomes followed by massive endocytosis. Extracellular activity of the lysosomal enzyme acid sphingomyelinase was previously shown to promote endocytosis and wound removal. However, whether lysosomal proteases released during cell injury participate in resealing is unknown. Here we show that lysosomal proteases regulate plasma membrane repair. Extracellular proteolysis is detected shortly after cell wounding, and inhibition of this process blocks repair. Conversely, surface protein degradation facilitates plasma membrane resealing. The abundant lysosomal cysteine proteases cathepsin B and L, known to proteolytically remodel the extracellular matrix, are rapidly released upon cell injury and are required for efficient plasma membrane repair. In contrast, inhibition of aspartyl proteases or RNAi-mediated silencing of the lysosomal aspartyl protease cathepsin D enhances resealing, an effect associated with the accumulation of active acid sphingomyelinase on the cell surface. Thus, secreted lysosomal cysteine proteases may promote repair by facilitating membrane access of lysosomal acid sphingomyelinase, which promotes wound removal and is subsequently downregulated extracellularly by a process involving cathepsin D. PMID:27028538

  13. 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...... analgesic treatment in LRYGB surgery....

  14. TECAB - Totally Endoscopic Coronary Artery Bypass

    Medline Plus

    Full Text Available ... completely endoscopic coronary artery bypass grafting procedure using robotics. We call this operation a “TECAB,” “Totally Endoscopic ... scrub nurse, also a lot of experience with robotics now. And Dr. Atiq Rahman, fellow here for ...

  15. 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....

  16. 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...

  17. TECAB - Totally Endoscopic Coronary Artery Bypass

    Medline Plus

    Full Text Available ... is in place right now. There’s usually some slack or redundancy in the balloon once we initially ... go on bypass, and then it’s without any slack in the right position, and we can inflate ...

  18. 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

  19. 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

  20. Is a fully heparin-bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?

    OpenAIRE

    Mahmood, Sarah; Bilal, Haris; Zaman, Mahvash; Tang, Augustine

    2012-01-01

    A best-evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘Is a fully heparin bonded cardiopulmonary bypass circuit superior to a standard cardiopulmonary bypass circuit?’ Altogether more than 792 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of...

  1. The lysosome as a command-and-control center for cellular metabolism.

    Science.gov (United States)

    Lim, Chun-Yan; Zoncu, Roberto

    2016-09-12

    Lysosomes are membrane-bound organelles found in every eukaryotic cell. They are widely known as terminal catabolic stations that rid cells of waste products and scavenge metabolic building blocks that sustain essential biosynthetic reactions during starvation. In recent years, this classical view has been dramatically expanded by the discovery of new roles of the lysosome in nutrient sensing, transcriptional regulation, and metabolic homeostasis. These discoveries have elevated the lysosome to a decision-making center involved in the control of cellular growth and survival. Here we review these recently discovered properties of the lysosome, with a focus on how lysosomal signaling pathways respond to external and internal cues and how they ultimately enable metabolic homeostasis and cellular adaptation. PMID:27621362

  2. Lysosomal ATP imaging in living cells by a water-soluble cationic polythiophene derivative.

    Science.gov (United States)

    Huang, Bing-Huan; Geng, Zhi-Rong; Ma, Xiao-Yan; Zhang, Cui; Zhang, Zhi-Yang; Wang, Zhi-Lin

    2016-09-15

    Lysosomes in astrocytes and microglia can release ATP as the signaling molecule for the cells through ca(2+)-dependent exocytosis in response to various stimuli. At present, fluorescent probes that can detect ATP in lysosomes have not been reported. In this work, we have developed a new water-soluble cationic polythiophene derivative that can be specifically localized in lysosomes and can be utilized as a fluorescent probe to sense ATP in cells. PEMTEI exhibits high selectivity and sensitivity to ATP at physiological pH values and the detection limit of ATP is as low as 10(-11)M. The probe has low cytotoxicity, good permeability and high photostability in living cells and has been applied successfully to real-time monitoring of the change in concentrations of ATP in lysosomes though fluorescence microscopy. We also demonstrated that lysosomes in Hela cells can release ATP through Ca(2+)-dependent exocytosis in response to drug stimuli. PMID:27131993

  3. 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.

  4. Potential pitfalls and solutions for use of fluorescent fusion proteins to study the lysosome.

    Directory of Open Access Journals (Sweden)

    Ling Huang

    Full Text Available Use of fusion protein tags to investigate lysosomal proteins can be complicated by the acidic, protease-rich environment of the lysosome. Potential artifacts include degradation or release of the tag and acid quenching of fluorescence. Tagging can also affect protein folding, glycosylation and/or trafficking. To specifically investigate the use of fluorescent tags to reveal lysosomal localization, we tested mCherry derivatives as C-terminal tags for Niemann-Pick disease type C protein 2 (NPC2, a luminal lysosomal protein. Full-length mCherry was released from the NPC2 chimera while deletion of the 11 N-terminal residues of mCherry generated a cleavage-resistant (cr fluorescent variant. Insertion of proline linkers between NPC2 and crmCherry had little effect while Gly-Ser linkers promoted cleavage. The NPC2-crmCherry fusion was targeted to the lysosome and restored function in NPC2-deficient cells. Fusion of crmCherry to known and candidate lysosomal proteins revealed that the linkers had different effects on lysosomal localization. Direct fusion of crmCherry impaired mannose 6-phosphorylation and lysosomal targeting of the lysosomal protease tripeptidyl peptidase I (TPP1, while insertion of linkers corrected the defects. Molecular modeling suggested structural bases for the effects of different linkers on NPC2 and TPP1 fusion proteins. While mCherry fusion proteins can be useful tools for studying the lysosome and related organelles, our findings underscore the potential artifacts associated with such applications.

  5. A quantitative assay for lysosomal acidification rates in human osteoclasts

    DEFF Research Database (Denmark)

    Jensen, Vicki Kaiser; Nosjean, Olivier; Dziegiel, Morten Hanefeld;

    2011-01-01

    The osteoclast initiates resorption by creating a resorption lacuna. The ruffled border surrounding the lacunae arises from exocytosis of lysosomes. To dissolve the inorganic phase of the bone, the vacuolar adenosine triphosphatase, located in the ruffled border, pumps protons into the resorption...... lacunae. The electroneutrality of the lacunae is maintained by chloride transport through the chloride-proton antiporter chloride channel 7. Inhibition of either proton or chloride transport prevents bone resorption. The aims of this study were to validate the human osteoclastic microsome- based influx......, the effect of valinomycin, inhibitor sensitivity, and the ion profile of the human osteoclast microsomes. The expression level of chloride channel 7 was increased in the human osteoclastic microsomes compared with whole osteoclasts. Acid influx was induced by 1.25 mM adenosine triphosphate. Further 1.1 μ...

  6. 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

  7. Diagnosing Lysosomal Storage Disorders: The GM2 Gangliosidoses.

    Science.gov (United States)

    Hall, Patricia; Minnich, Sara; Teigen, Claire; Raymond, Kimiyo

    2014-01-01

    The GM2 gangliosidoses are a group of autosomal recessive lysosomal storage disorders caused by defective β-hexosaminidase. There are three clinical conditions in this group: Tay-Sachs disease (TSD), Sandhoff disease (SD), and hexosaminidase activator deficiency. The three conditions are clinically indistinguishable. TSD and SD have been identified with infantile, juvenile, and adult onset forms. The activator deficiency is only known to present with infantile onset. Diagnosis of TSD and SD is based on decreased hexosaminidase activity and a change in the percentage of activity between isoforms. There are no biochemical tests currently available for activator deficiency. This unit provides a detailed procedure for identifying TSD and SD in affected individuals and carriers from leukocyte samples, the most robust sample type available. PMID:25271840

  8. 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.

  9. 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Geum-Hwa Lee

    Full Text Available 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.

  12. 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.

  13. 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.

  14. 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

  15. Temporary extracorporeal bypass modalities during aortic surgery.

    Science.gov (United States)

    Bassin, Levi; Bell, David

    2016-09-01

    The key to aortic surgery is protection of the brain, heart, spinal cord, and viscera. For operations involving the aortic arch, the focus is on cerebral protection, while for pathology involving the descending thoracic aorta, the focus is on spinal protection. Optimal cerebral and spinal protection requires an extensive knowledge of the operative steps and an understanding of the cardiopulmonary bypass modalities that are possible. A bloodless field is required when operating on the aorta. As a result, periods of ischemia to the central nervous system and end-organ viscera are often unavoidable. The main techniques to mitigate ischemia include hypothermia and selective perfusion of the ischemic organ in question. This chapter will first briefly review bypass modalities and then describe how they can be used for various aortic scenarios. PMID:27650344

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

    DEFF Research Database (Denmark)

    Jensen, Stine Skov; Christensen, Karina; Aaberg-Jessen, Charlotte;

    aim of this study was to investigate the immunohistochemical expression of LAMP-1, a membrane bound protein in lysosomes, in formalin fixed paraffin embedded tumor tissue from 23 diffuse astrocytomas, 17 anaplastic astrocytomas and 72 glioblastomas. The LAMP-1 expression was scored and compared with......Targeting lysosomes is a novel approach in cancer therapy providing a possible way of killing the otherwise apoptosis-resistant cancer cells. Recent research has thus shown that lysosome targeting compounds induce cell death in a cervix cancer cell line. Tumor stem cells in glioblastomas have...

  17. A Two-Photon Fluorescent Probe for Lysosomal Thiols in Live Cells and Tissues

    Science.gov (United States)

    Fan, Jiangli; Han, Zhichao; Kang, Yao; Peng, Xiaojun

    2016-01-01

    Lysosome-specific fluorescent probes are exclusive to elucidate the functions of lysosomal thiols. Moreover, two-photon microscopy offers advantages of less phototoxicity, better three dimensional spatial localization, deeper penetration depth and lower self-absorption. However, such fluorescent probes for thiols are still rare. In this work, an efficient two-photon fluorophore 1,8-naphthalimide-based probe conjugating a 2,4-dinitrobenzenesulfonyl chloride and morpholine was designed and synthesized, which exhibited high selectivity and sensitivity towards lysosomal thiols by turn-on fluorescence method quantitatively and was successfully applied to the imaging of thiols in live cells and tissues by two-photon microscopy.

  18. 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.

  19. Efficiency Biliopancreatic bypass surgery in bulimia nervosa

    OpenAIRE

    Yu I Yashkov; D K Bekuzarov; A V Nikol'skiy

    2008-01-01

    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 dat...

  20. Factor V Leiden and Cardiopulmonary Bypass

    OpenAIRE

    Uppal, Victor; Rosin, Mark; Marcoux, Jo-Anne; Olson, Marnie; Bezaire, Jennifer; Dalshaug, Gregory

    2015-01-01

    We present a case of a patient with factor V Leiden with an antithrombin III activity of 67% who received a successful aortic valve replacement supported by cardiopulmonary bypass (CPB). A safe level of anticoagulation was achieved by monitoring activated clotting time (ACT) and heparin concentration ensuring adequate anticoagulation throughout the procedure. Results from ACT, heparin dose response, heparin protamine titration, and thrombelastography are given. Factor V Leiden patients can be...

  1. 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.

  2. 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.

  3. 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.

  4. [Robot-assisted Coronary Artery Bypass Grafting].

    Science.gov (United States)

    Ishikawa, Norihiko; Watanabe, Go

    2016-07-01

    The application for robot-assisted coronary surgery ranges from internal thoracic artery (ITA) harvesting with hand-sewn anastomoses to totally endoscopic coronary artery bypass grafting (TECAB), either on- or off-pump. The bilateral IMA can be harvested with the aid of a surgical robot and then multivessel bypass grafting can follow. Such robot-assisted minimally invasive direct coronary artery bypass grafting is called "ThoraCAB". Surgical robots cannot only endoscopically harvest the ITA but they can also anastomose the coronary artery in TECAB. But TECAB still has the difficulties, such as narrow surgical field in Japanese patients. Both procedures have the significant advantages of minimizing surgical trauma, such as reduced comlications, faster return back to normal activities and being improved cosmesis, and which have resulted in the development of minimally invasive surgery. Robot-assisted cardiac surgery for structural heart disease has been approved by the Ministry of Health, Labour and Welfare (MHLW) since December 2015, however, robot-assisted cardiac surgery for TECAB has not been approved yet in Japan.

  5. Vein harvesting and techniques for infrainguinal bypass.

    Science.gov (United States)

    Albäck, Anders; Saarinen, Eva; Venermo, Maarit

    2016-04-01

    In order to achieve good long term results after bypass surgery, alongside with good inflow and outflow arteries, the bypass graft material also has an important role. The best patency and limb salvage rates are achieved with autologous vein. If great saphenous vein is not available, acceptable long-term results can be achieved with arm veins and lesser saphenous vein. The quality and size of the vein are important. A small-caliber vein, increased wall thickness, postphlebitic changes and varicosities are associated with a risk of early failure. Preoperative vein mapping with ultrasound reduces readmissions and postoperative surgical site infections. During the mapping, the vein to be used and its main tributaries are marked with a permanent marker pen. To reduce wound complication rates we recommend bridged incisions in vein harvesting. Endoscopic vein harvesting seems to have no benefit compared to open techniques in lower limb bypasses, and has been associated with higher risk of primary patency loss at one year. With deep tunneling of the graft the problems caused by wound infection can be avoided. PMID:26837257

  6. 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.

  7. 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.

  8. Oral small molecule therapy for lysosomal storage diseases.

    Science.gov (United States)

    Weinreb, Neal J

    2013-11-01

    For more than 20 years, "enzyme replacement therapy" (ERT) has been the prevalent treatment approach for lysosomal storage disorders (LSDs). Unfortunately, ERT, as currently administered, is ineffective for primary neuronopathic LSDs. For LSDs whose major disease burden is non-neurological, ERT efficacy is limited by uneven tissue distribution and penetration, immunological intolerance, and disturbed intracellular homeostasis associated with persistent mutant enzymes that are not "replaced" by ERT. Many of these limitations might be circumvented by oral, low molecular weight pharmaceuticals that address relevant LSD pathophysiology and distribute widely in steady state concentrations in all cells and body tissues including the CNS. Two oral small molecule drugs (miglustat and cysteamine) are currently approved for clinical use and two (eliglustat and migalastat) are in advanced stage clinical trials. Several others are in early stages of clinical or pre-clinical investigation. This article reviews current knowledge of small molecule treatment for LSDs including approaches such as substrate synthesis inhibition, pharmacological chaperones, and proteostasis modification. PMID:24380126

  9. 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.

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

    Science.gov (United States)

    Coutinho, Maria Francisca; Santos, Juliana Inês; Alves, Sandra

    2016-01-01

    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. PMID:27384562

  11. 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

  12. 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.

  13. Purification of the lysosomal sialic acid transporter. Functional characteristics of a monocarboxylate transporter

    NARCIS (Netherlands)

    A.C. Havelaar (Adrie); G.M.S. Mancini (Grazia); C.E.M.T. Beerens (Cecile); R.M. Souren; F.W. Verheijen (Frans)

    1998-01-01

    textabstractSialic acid and glucuronic acid are monocarboxylated monosaccharides, which are normally present in sugar side chains of glycoproteins, glycolipids, and glycosaminoglycans. After degradation of these compounds in lysosomes, the free monosaccharides are relea

  14. 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.

  15. Outcomes after off-pump coronary bypass surgery

    OpenAIRE

    van Dijk, Diederik

    2002-01-01

    The complications associated with in coronary artery bypass surgery (CABG) using cardiopulmonary bypass (CPB) have led to a renewed interest in coronary bypass surgery on the beating heart. The primary objective of the Octopus Study was to compare cognitive outcome between patients randomized to off-pump or on-pump CABG. In chapter 2, the literature suggesting that CABG may impair cognitive function is systematically reviewed and chapter 3 describes in detail the rationale and design of the O...

  16. 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....

  17. 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...... hemodynamic conditions of a more severe stenosis. Assessment of the hemodynamic impact of fistulas must be undertaken in the evaluation of in situ vein bypass stenoses....

  18. Lysosomal exocytosis in response to subtle membrane damage following nanosecond pulse exposure

    Science.gov (United States)

    Dalzell, Danielle R.; Roth, Caleb C.; Bernhard, Joshua A.; Payne, Jason A.; Wilmink, Gerald J.; Ibey, Bennett L.

    2011-03-01

    The cellular response to subtle membrane damage following exposure to nanosecond electric pulses (nsEP) is not well understood. Recent work has shown that when cells are exposed to nsEP, ion permeable nanopores ( 2nm) created by longer micro and millisecond duration pulses. Macroscopic damage to a plasma membrane by a micropipette has been shown to cause internal vesicles (lysosomes) to undergo exocytosis to repair membrane damage, a calcium mediated process called lysosomal exocytosis. Formation of large pores in the plasma membrane by electrical pulses has been shown to elicit lysosomal exocytosis in a variety of cell types. Our research objective is to determine whether lysosomal exocytosis will occur in response to nanopores formed by exposure to nsEP. In this paper we used propidium iodide (PI) and Calcium Green-1 AM ester (CaGr) to differentiate between large and small pores formed in CHO-K1 cells following exposure to either 1 or 20, 600-ns duration electrical pulses at 16.2 kV/cm. This information was compared to changes in membrane organization observed by increases in FM1-43 fluorescence, both in the presence and absence of calcium ions in the outside buffer. In addition, we monitored the real time migration of lysosomes within the cell using Cellular Lights assay to tag LAMP-1, a lysosomal membrane protein. Both 1 and 20 pulses elicited a large influx of extracellular calcium, while little PI uptake was observed following a single pulse exposure. Statistically significant increases in FM1-43 fluorescence were seen in samples containing calcium suggesting that calcium-triggered membrane repair may be occurring. Lastly, density of lysosomes within cells, specifically around the nucleus, appeared to change rapidly upon nsEP stimulation suggesting lysosomal migration.

  19. Oxidative Stress and Autophagy in the Regulation of Lysosome-Dependent Neuron Death

    OpenAIRE

    Pivtoraiko, Violetta N.; Stone, Sara L; Roth, Kevin A.; Shacka, John J

    2009-01-01

    Lysosomes critically regulate the pH-dependent catabolism of extracellular and intracellular macromolecules delivered from the endocytic/heterophagy and autophagy pathways, respectively. The importance of lysosomes to cell survival is underscored not only by their unique ability effectively to degrade metalloproteins and oxidatively damaged macromolecules, but also by the distinct potential for induction of both caspase-dependent and -independent cell death with a compromise in the integrity ...

  20. Apolipoprotein L-I Promotes Trypanosome Lysis by Forming Pores in Lysosomal Membranes

    Science.gov (United States)

    Pérez-Morga, David; Vanhollebeke, Benoit; Paturiaux-Hanocq, Françoise; Nolan, Derek P.; Lins, Laurence; Homblé, Fabrice; Vanhamme, Luc; Tebabi, Patricia; Pays, Annette; Poelvoorde, Philippe; Jacquet, Alain; Brasseur, Robert; Pays, Etienne

    2005-07-01

    Apolipoprotein L-I is the trypanolytic factor of human serum. Here we show that this protein contains a membrane pore-forming domain functionally similar to that of bacterial colicins, flanked by a membrane-addressing domain. In lipid bilayer membranes, apolipoprotein L-I formed anion channels. In Trypanosoma brucei, apolipoprotein L-I was targeted to the lysosomal membrane and triggered depolarization of this membrane, continuous influx of chloride, and subsequent osmotic swelling of the lysosome until the trypanosome lysed.

  1. The HOPS complex mediates autophagosome–lysosome fusion through interaction with syntaxin 17

    OpenAIRE

    Jiang, Peidu; Nishimura, Taki; Sakamaki, Yuriko; Itakura, Eisuke; Hatta, Tomohisa; Natsume, Tohru; Mizushima, Noboru

    2014-01-01

    Membrane fusion is generally controlled by Rabs, soluble N-ethylmaleimide–sensitive factor attachment protein receptors (SNAREs), and tethering complexes. Syntaxin 17 (STX17) was recently identified as the autophagosomal SNARE required for autophagosome–lysosome fusion in mammals and Drosophila. In this study, to better understand the mechanism of autophagosome–lysosome fusion, we searched for STX17-interacting proteins. Immunoprecipitation and mass spectrometry analysis identified vacuolar p...

  2. Activation of macrophages by lymphokines: enhancement of phagosome-lysosome fusion and killing of Coccidioides immitis.

    OpenAIRE

    Beaman, L; Benjamini, E; Pappagianis, D

    1983-01-01

    Previously, it was shown that arthroconidia of Coccidioides immitis appear to inhibit phagosome-lysosome fusion and survive within normal mouse peritoneal macrophages. However, when these macrophages are exposed to antigen-stimulated T lymphocytes from immune mice, activation occurs, leading to enhanced phagosome-lysosome fusion and killing of C. immitis. Results indicate that the activation of macrophages can be effected after incubation with soluble lymphocyte product(s) (lymphokines). The ...

  3. Cryptococcus neoformans-induced macrophage lysosome damage crucially contributes to fungal virulence1

    OpenAIRE

    Davis, Michael J.; Eastman, Alison J.; Qiu, Yafeng; Gregorka, Brian; Kozel, Thomas R.; Osterholzer, John J.; Curtis, Jeffrey L; Swanson, Joel A.; Michal A Olszewski

    2015-01-01

    Upon ingestion by macrophages, Cryptococcus neoformans (Cn) can survive and replicate intracellularly unless the macrophages become classically activated. The mechanism enabling intracellular replication is not fully understood; neither are the mechanisms which allow classical activation to counteract replication. Cn-induced lysosome damage was observed in infected murine bone marrow-derived macrophages, increased with time and required yeast viability. To demonstrate lysosome damage in the i...

  4. Distinct Lysosome Phenotypes Influence Inflammatory Function in Peritoneal and Bone Marrow-Derived Macrophages

    OpenAIRE

    Kassandra Weber; Schilling, Joel D.

    2014-01-01

    Lysosomes play a critical role in the degradation of both extracellular and intracellular material. These dynamic organelles also contribute to nutrient sensing and cell signaling pathways. Macrophages represent a heterogeneous group of phagocytic cells that contribute to tissue homeostasis and inflammation. Recently, there has been a renewed interest in understanding the role of macrophage autophagy and lysosome function in health and disease. Thioglycollate-elicited peritoneal and bone marr...

  5. Exosome Secretion Ameliorates Lysosomal Storage of Cholesterol in Niemann-Pick Type C Disease*

    OpenAIRE

    STRAUSS, K; C. GOEBEL; Runz, H.; Mobius, W.; Weiss, S; Feussner, I.; M. Simons; A. Schneider

    2010-01-01

    Niemann-Pick type C1 disease is an autosomal-recessive lysosomal storage disorder. Loss of function of the npc1 gene leads to abnormal accumulation of free cholesterol and sphingolipids within the late endosomal and lysosomal compartments resulting in progressive neurodegeneration and dysmyelination. Here, we show that oligodendroglial cells secrete cholesterol by exosomes when challenged with cholesterol or U18666A, which induces late endosomal cholesterol accumulation. Up-regulation of exos...

  6. 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

  7. Analysis of lysosomal membrane proteins exposed to melanin in HeLa cells

    OpenAIRE

    Bang, Seung Hyuck; Park, Dong Jun; Kim, Yang-Hoon; Min, Jiho

    2016-01-01

    Objectives There have been developed to use targeting ability for antimicrobial, anticancerous, gene therapy and cosmetics through analysis of various membrane proteins isolated from cell organelles. Methods It was examined about the lysosomal membrane protein extracted from lysosome isolated from HeLa cell treated by 100 ppm melanin for 24 hours in order to find associated with targeting ability to melanin using by 2-dimensional electrophoresis. Results The result showed 14 up-regulated (1.5...

  8. 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. PMID:27113357

  9. 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...... correlate with regional pathology. Overloading of this system might impair the function of lysosomal enzymes and thus may mimic some features of lysosomal storage disorders. Udgivelsesdato: 2007-Jul...

  10. Cardiac Bypass Pump Flow Management via NIRS Monitoring

    OpenAIRE

    Macnab, Andrew J.; Gagnon, Roy E.; Gagnon, Faith A.; Blackstock, Derek; LeBlanc, Jacques G.

    2003-01-01

    During cardiac surgery, bypass pumps rely on pressure monitors to evaluate flow. We studied whether it would be possible to optimize pump flow by monitoring changes in cerebral cytochrome a,a3 using NIRS to maintain cyt redox status at its pre-bypass level. Method: 18 healthy 7–45 kg swine were placed on bypass for repeated cycles of cooling and re-warming from 36 to 15 to 36°C in 3°C steps. Between each cycle, the swine's bypass pump blood flow rate was adjusted to restore cytochrome redox s...

  11. 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.

  12. 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.

  13. Wilson Disease Protein ATP7B Utilizes Lysosomal Exocytosis to Maintain Copper Homeostasis

    Science.gov (United States)

    Polishchuk, Elena V.; Concilli, Mafalda; Iacobacci, Simona; Chesi, Giancarlo; Pastore, Nunzia; Piccolo, Pasquale; Paladino, Simona; Baldantoni, Daniela; van IJzendoorn, Sven C.D.; Chan, Jefferson; Chang, Christopher J.; Amoresano, Angela; Pane, Francesca; Pucci, Piero; Tarallo, Antonietta; Parenti, Giancarlo; Brunetti-Pierri, Nicola; Settembre, Carmine; Ballabio, Andrea; Polishchuk, Roman S.

    2014-01-01

    Summary Copper is an essential yet toxic metal and its overload causes Wilson disease, a disorder due to mutations in copper transporter ATP7B. To remove excess copper into the bile, ATP7B traffics toward canalicular area of hepatocytes. However, the trafficking mechanisms of ATP7B remain elusive. Here, we show that, in response to elevated copper, ATP7B moves from the Golgi to lysosomes and imports metal into their lumen. ATP7B enables lysosomes to undergo exocytosis through the interaction with p62 subunit of dynactin that allows lysosome translocation toward the canalicular pole of hepatocytes. Activation of lysosomal exocytosis stimulates copper clearance from the hepatocytes and rescues the most frequent Wilson-disease-causing ATP7B mutant to the appropriate functional site. Our findings indicate that lysosomes serve as an important intermediate in ATP7B trafficking, whereas lysosomal exocytosis operates as an integral process in copper excretion and hence can be targeted for therapeutic approaches to combat Wilson disease. PMID:24909901

  14. An efficient ratiometric fluorescent probe for tracking dynamic changes in lysosomal pH.

    Science.gov (United States)

    Wang, Qianqian; Zhou, Liyi; Qiu, Liping; Lu, Danqing; Wu, Yongxiang; Zhang, Xiao-Bing

    2015-08-21

    Lysosomes are acidic organelles (approximately pH 4.5-5.5) and tracking the changes in lysosomal pH is of great biological importance. To address this issue, quite a few of fluorescent probes have been developed. However, few of these probes can realize the tracking of dynamic changes in lysosomal pH. Herein, we report a new lysosome-targeted ratiometric fluorescent probe (FR-Lys) by hybridizing morpholine with a xanthane derivative and an o-hydroxy benzoxazole group. In this probe, the morpholine group serves as a targeting unit for lysosome, the xanthane derivative exhibits a pH-modulated open/close reaction of the spirocycle, while the o-hydroxy benzoxazole moiety shows a pH modulated excited-state intramolecular proton transfer (ESIPT) process. Such a design affords the probe a ratiometric fluorescence response towards pH with pH values ranging from 4.0 to 6.3. The response of the probe to pH was fast and reversible with high selectivity. Moreover, this probe possesses further advantages such as easy synthesis, high photostability and low cytotoxicity. These features are favorable for tracking dynamic pH changes in biosystems. It was then applied for dynamic imaging pH changes in lysosomes with satisfactory results. PMID:26107774

  15. TFEB activation promotes the recruitment of lysosomal glycohydrolases β-hexosaminidase and β-galactosidase to the plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Magini, Alessandro [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Department of Medical and Biological Sciences (DSMB), University of Udine, Udine (Italy); Polchi, Alice; Urbanelli, Lorena [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Cesselli, Daniela; Beltrami, Antonio [Department of Medical and Biological Sciences (DSMB), University of Udine, Udine (Italy); Tancini, Brunella [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Emiliani, Carla, E-mail: carla.emiliani@unipg.it [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy)

    2013-10-18

    Highlights: •TFEB activation promotes the increase of Hex and Gal activities. •The increase of Hex and Gal activities is related to transcriptional regulation. •TFEB promotes the recruitment of mature Hex and Gal on cell surface. -- Abstract: Lysosomes are membrane-enclosed organelles containing acid hydrolases. They mediate a variety of physiological processes, such as cellular clearance, lipid homeostasis, energy metabolism and pathogen defence. Lysosomes can secrete their content through a process called lysosome exocytosis in which lysosomes fuse with the plasma membrane realising their content into the extracellular milieu. Lysosomal exocytosis is not only responsible for the secretion of lysosomal enzymes, but it also has a crucial role in the plasma membrane repair. Recently, it has been demonstrated that lysosome response to the physiologic signals is regulated by the transcription factor EB (TFEB). In particular, lysosomal secretion is transcriptionally regulated by TFEB which induces both the docking and fusion of lysosomes with the plasma membrane. In this work we demonstrated that TFEB nuclear translocation is accompanied by an increase of mature glycohydrolases β-hexosaminidase and β-galactosidase on cell surface. This evidence contributes to elucidate an unknown TFEB biological function leading the lysosomal glycohydrolases on plasma membrane.

  16. Glucose Modulation Induces Lysosome Formation and Increases Lysosomotropic Drug Sequestration via the P-Glycoprotein Drug Transporter.

    Science.gov (United States)

    Seebacher, Nicole A; Lane, Darius J R; Jansson, Patric J; Richardson, Des R

    2016-02-19

    Pgp is functional on the plasma membrane and lysosomal membrane. Lysosomal-Pgp can pump substrates into the organelle, thereby trapping certain chemotherapeutics (e.g. doxorubicin; DOX). This mechanism serves as a "safe house" to protect cells against cytotoxic drugs. Interestingly, in contrast to DOX, lysosomal sequestration of the novel anti-tumor agent and P-glycoprotein (Pgp) substrate, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), induces lysosomal membrane permeabilization. This mechanism of lysosomal-Pgp utilization enhances cytotoxicity to multidrug-resistant cells. Consequently, Dp44mT has greater anti-tumor activity in drug-resistant relative to non-Pgp-expressing tumors. Interestingly, stressors in the tumor microenvironment trigger endocytosis for cell signaling to assist cell survival. Hence, this investigation examined how glucose variation-induced stress regulated early endosome and lysosome formation via endocytosis of the plasma membrane. Furthermore, the impact of glucose variation-induced stress on resistance to DOX was compared with Dp44mT and its structurally related analogue, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC). These studies showed that glucose variation-induced stress-stimulated formation of early endosomes and lysosomes. In fact, through the process of fluid-phase endocytosis, Pgp was redistributed from the plasma membrane to the lysosomal membrane via early endosome formation. This lysosomal-Pgp actively transported the Pgp substrate, DOX, into the lysosome where it became trapped as a result of protonation at pH 5. Due to increased lysosomal DOX trapping, Pgp-expressing cells became more resistant to DOX. In contrast, cytotoxicity of Dp44mT and DpC was potentiated due to more lysosomes containing functional Pgp under glucose-induced stress. These thiosemicarbazones increased lysosomal membrane permeabilization and cell death. This mechanism has critical implications for drug-targeting in

  17. 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

  18. Impossible Airway Requiring Venovenous Bypass for Tracheostomy

    Directory of Open Access Journals (Sweden)

    Johnathan Gardes

    2012-01-01

    Full Text Available The elective surgical airway is the definitive management for a tracheal stenotic lesion that is not a candidate for tracheal resection, or who has failed multiple-tracheal dilations. This case report details the management of a patient who has failed an elective awake tracheostomy secondary to the inability to be intubated as well as severe scar tissue at the surgical site. A combination of regional anesthesia and venovenous bypass is used to facilitate the surgical airway management of this patient. Cerebral oximetry and a multidisciplinary team approach aid in early detection of an oxygenation issue, as well as the emergent intervention that preserved this patient’s life.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Reverse bias protected solar array with integrated bypass battery

    Science.gov (United States)

    Landis, Geoffrey A (Inventor)

    2012-01-01

    A method for protecting the photovoltaic cells in a photovoltaic (PV) array from reverse bias damage by utilizing a rechargeable battery for bypassing current from a shaded photovoltaic cell or group of cells, avoiding the need for a bypass diode. Further, the method mitigates the voltage degradation of a PV array caused by shaded cells.

  7. 46 CFR 56.20-20 - Valve bypasses.

    Science.gov (United States)

    2010-10-01

    ... (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2010-10-01 2010-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...

  8. 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

  9. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4420 Cardiopulmonary bypass cardiotomy...

  10. 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....

  11. 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....

  12. 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

  13. Obstetrical and neonatal outcomes in women following gastric bypass

    DEFF Research Database (Denmark)

    Berlac, Janne Foss; Skovlund, Charlotte Wessel; Lidegaard, Ojvind

    2014-01-01

    OBJECTIVE: To assess obstetrical and neonatal outcomes in women following gastric bypass, compared with adipose women without surgery and with a normal weight control population. DESIGN: Historical controlled cohort study. SETTING: Denmark. POPULATION: All women undergoing gastric bypass during...... the period 1996-2011, and subsequently giving birth. METHODS AND MAIN OUTCOME MEASURES: Obstetrical and neonatal outcomes in women without gastric bypass matched on age, parity, plurality, year, and body mass index, and normal weight women. RESULTS: In 415 women giving birth after gastric bypass we found...... 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...

  14. Lysosome fusion to the cell membrane is mediated by the dysferlin C2A domain in coronary arterial endothelial cells

    OpenAIRE

    Han, Wei-Qing; Xia, Min; Xu, Ming; Krishna M Boini; Ritter, Joseph K.; Li, Ning-Jun; Li, Pin-Lan

    2012-01-01

    Dysferlin has recently been reported to participate in cell membrane repair in muscle and other cells through lysosome fusion. Given that lysosome fusion is a crucial mechanism that leads to membrane raft clustering, the present study attempted to determine whether dysferlin is involved in this process and its related signalling, and explores the mechanism underlying dysferlin-mediated lysosome fusion in bovine coronary arterial endothelial cells (CAECs). We found that dysferlin is clustered ...

  15. Intracellular targeting of peroxiredoxin 6 to lysosomal organelles requires MAPK activity and binding to 14-3-3ε

    OpenAIRE

    Sorokina, Elena M.; Feinstein, Sheldon I.; Zhou, Suiping; Fisher, Aron B.

    2011-01-01

    Peroxiredoxin 6 (Prdx6), a bifunctional protein with GSH peroxidase and lysosomal-type phospholipase A2 activities, has been localized to both cytosolic and acidic compartments (lamellar bodies and lysosomes) in lung alveolar epithelium. We postulate that Prdx6 subcellular localization affects the balance between the two activities. Immunostaining localized Prdx6 to lysosome-related organelles in the MLE12 and A549 alveolar epithelial cell lines. Inhibition of trafficking by brefeldin A indic...

  16. Lack of lysosomal fusion with phagosomes containing Ehrlichia risticii in P388D1 cells: abrogation of inhibition with oxytetracycline.

    OpenAIRE

    Wells, M Y; Rikihisa, Y

    1988-01-01

    Fusion of lysosomes with phagosomes containing Ehrlichia risticii, an obligate intracellular parasite, was evaluated in P388D1 murine macrophagelike cells. Lysosomes in cells ranging in infectivity from 30 to 70% were labeled cytochemically with acid phosphatase or via endocytosis of thorium dioxide or cationized ferritin to document phagosome-lysosome (P-L) fusion in untreated cells and cells treated with oxytetracycline. Regardless of the marker used, P-L fusion was generally not observed i...

  17. Protective effect of squalene on certain lysosomal hydrolases and free amino acids in isoprenaline-induced myocardial infarction in rats

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Surendraraj, A.; Anandan, R.

    2010-01-01

    This study was aimed to evaluate the preventive role of squalene on free amino acids and lysosomal alterations in experimentally induced myocardial infarction in rats. The levels of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, beta-glucosidase, acid phosphatase and cathepsin D......) in plasma and lysosomal fractions, hydroxyproline content and free amino acids in heart tissue were determined. Isoprenaline administration to rats resulted in decreased stability of the membranes which was reflected by significantly (p...

  18. 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.

  19. Depletion of kinesin 5B affects lysosomal distribution and stability and induces peri-nuclear accumulation of autophagosomes in cancer cells

    DEFF Research Database (Denmark)

    Cardoso, Carla M P; Groth-Pedersen, Line; Høyer-Hansen, Maria;

    2009-01-01

    BACKGROUND: Enhanced lysosomal trafficking is associated with metastatic cancer. In an attempt to discover cancer relevant lysosomal motor proteins, we compared the lysosomal proteomes from parental MCF-7 breast cancer cells with those from highly invasive MCF-7 cells that express an active form...... of the ErbB2 (DeltaN-ErbB2). METHODOLOGY/PRINCIPAL FINDINGS: Mass spectrometry analysis identified kinesin heavy chain protein KIF5B as the only microtubule motor associated with the lysosomes in MCF-7 cells, and ectopic DeltaN-ErbB2 enhanced its lysosomal association. KIF5B associated with lysosomes also...... in HeLa cervix carcinoma cells as analyzed by subcellular fractionation. The depletion of KIF5B triggered peripheral aggregations of lysosomes followed by lysosomal destabilization, and cell death in HeLa cells. Lysosomal exocytosis in response to plasma membrane damage as well as fluid phase...

  20. Cathepsin B launches an apoptotic exit effort upon cell death-associated disruption of lysosomes.

    Science.gov (United States)

    de Castro, M A G; Bunt, G; Wouters, F S

    2016-01-01

    The release of cathepsin proteases from disrupted lysosomes results in lethal cellular autodigestion. Lysosomal disruption-related cell death is highly variable, showing both apoptotic and necrotic outcomes. As the substrate spectrum of lysosomal proteases encompasses the apoptosis-regulating proteins of the Bcl-2 family, their degradation could influence the cell death outcome upon lysosomal disruption. We used Förster resonance energy transfer (FRET)-based biosensors to image the real-time degradation of the Bcl-2-family members, Bcl-xl, Bax and Bid, in living cells undergoing lysosomal lysis and identified an early chain of proteolytic events, initiated by the release of cathepsin B, which directs cells toward apoptosis. In this apoptotic exit strategy, cathepsin B's proteolytic activity results in apoptosis-inducing Bid and removes apoptosis-preventing Bcl-xl. Cathepsin B furthermore appears to degrade a cystein protease that would otherwise have eliminated apoptosis-supporting Bax, indirectly keeping cellular levels of the Bax protein up. The concerted effort of these three early events shifts the balance of cell fate away from necrosis and toward apoptosis. PMID:27551506

  1. 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.

  2. Lysosomes and apoptosis%溶酶体与细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    赵凯; 卫涛涛

    2011-01-01

    在特定条件下,包括活性氧、鞘氨醇、细胞凋亡效应因子Bax等在内的多种刺激因子均可诱发溶酶体膜通透,之后溶酶体内含的蛋白酶(如组织蛋白酶等)及其他水解酶从溶酶体释放至胞浆中,通过剪切效应分子、激活包括凋亡酶在内的其他水解酶而启动细胞凋亡程序的执行.简要概括了引发溶酶体膜通透的可能机制及溶酶体参与细胞凋亡的主要途径.%In certain conditions, lysosomal membrane permeabilization could be induced by a broad array of stimuli including reactive oxygen species (ROS), sphingosine, and some endogenous cell death effector proteins such as Bax. As a consequence of LMP, lysosomal proteases (such as cathepsins) and other hydrolases were released from the lysosomal lumen to the cytosol, where they lead to apoptosis by the activation apoptotic cascades. This review describes the possible molecular mechanisms underlying the occurrence of lysosomal membrane permeabilization and the consequent lysosome-mediated apoptosis.

  3. Cytochemical localisation of lysosomal enzymes and acidic mucopolysaccharides in the salivary glands of Aplysia depilans (Opisthobranchia).

    Science.gov (United States)

    Lobo-da-Cunha, A

    2002-04-01

    Three types of secretory cells were reported in the salivary glands of Aplysia depilans: granular cells, vacuolated cells and mucocytes. To improve the characterisation of these cells, cytochemical methods for the detection of lysosomal enzymes and acidic mucopolysaccharides were applied. In granular cells, acid phosphatase and arylsulphatase were present in small lysosomes and in some secretory granules. The secretory granules could have received these enzymes after fusion with the small lysosomes that were frequently found very close to them. These cells were not stained with colloidal iron because they do not contain acidic mucopolysaccharides. In vacuolated cells, acid phosphatase and arylsulphatase were detected in lysosomes but not in the secretory vacuoles. Colloidal iron staining revealed the presence of acidic mucopolysaccharides in the vacuoles and in the Golgi apparatus of these cells. In mucocytes, lysosomes were very rare, but the secretion of these cells was very rich in acidic mucopolysaccharides. The filamentous network within the secretory vesicles was completely covered with iron particles, but practically no particles were observed over the granular masses attached to the membrane of the vesicles. Iron particles were also found in the trans-face cisternae of the U-shaped Golgi stacks, but were not seen in the cis-face cisternae or in the rough endoplasmic reticulum. PMID:12117284

  4. TNFα Post-Translationally Targets ZnT2 to Accumulate Zinc in Lysosomes.

    Science.gov (United States)

    Hennigar, Stephen R; Kelleher, Shannon L

    2015-10-01

    Mammary epithelial cells undergo widespread lysosomal-mediated cell death (LCD) during early mammary gland involution. Recently, we demonstrated that tumor necrosis factor-α (TNFα), a cytokine released during early involution, redistributes the zinc (Zn) transporter ZnT2 to accumulate Zn in lysosomes and activate LCD and involution. The objective of this study is to determine how TNFα retargets ZnT2 to lysosomes. We tested the hypothesis that TNFα signaling dephosphorylates ZnT2 to uncover a highly conserved dileucine motif (L294L) in the C-terminus of ZnT2, allowing adaptor protein complex-3 (AP-3) to bind and traffic ZnT2 to lysosomes. Confocal micrographs showed that TNFα redistributed wild-type (WT) ZnT2 from late endosomes (Pearson's coefficient = 0.202 ± 0.05 and 0.097 ± 0.03; Pwomen with variation in the C-terminus of ZnT2 may be at risk for inadequate involution and breast disease due the inability to traffic ZnT2 to lysosomes. PMID:25808614

  5. Burn-induced stimulation of lysosomal enzyme synthesis in skeletal muscle

    International Nuclear Information System (INIS)

    A localized burn injury to a rat hindlimb results in atrophy of soleus muscle (in the absence of cellular damage) which is attributable to an increase in muscle protein breakdown. Previous work has shown that lysosomal enzyme activities (cathepsins B, H, L, and D) are elevated in muscle from the burned leg by 50% to 100%. There is no change in endogenous neutral protease activity (+/- Ca++). The increase in protease activity can not be attributed to changes in endogenous protease inhibitors. The latency [(Triton X100 treated - control)/triton treated] of lysosomal enzymes is approximately 50% and is not altered by burn injury. The rate of sucrose uptake is also not altered by burn. These experiments suggest that the rate of substrate supply to the lysosomal apparatus via endocytosis or autophagocytosis is not altered by burn. When muscles are preincubated with 3H-phenylalanine or 3H-mannose burn increased incorporation into protein of the fraction containing lysosomes by 100%. Preincubation in the presence of tunicamycin (an inhibitor of glycoprotein synthesis) inhibited incorporation of both labels into a microsomal fraction of the muscle from the burned leg, but has little effect on incorporation in the control muscle. These findings are consistent with the hypothesis that the burn-induced increase in protein breakdown is caused by an increase in lysosomal protease synthesis

  6. Giant Lysosomes as a Chemotherapy Resistance Mechanism in Hepatocellular Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Federico Colombo

    Full Text Available Despite continuous improvements in therapeutic protocols, cancer-related mortality is still one of the main problems facing public health. The main cause of treatment failure is multi-drug resistance (MDR: simultaneous insensitivity to different anti-cancer agents, the underlying molecular and biological mechanisms of which include the activity of ATP binding cassette (ABC proteins and drug compartmentalisation in cell organelles. We investigated the expression of the main ABC proteins and the role of cytoplasmic vacuoles in the MDR of six hepatocellular carcinoma (HCC cell lines, and confirmed the accumulation of the yellow anti-cancer drug sunitinib in giant (four lines and small cytoplasmic vacuoles of lysosomal origin (two lines. ABC expression analyses showed that the main ABC protein harboured by all of the cell lines was PGP, whose expression was not limited to the cell membrane but was also found on lysosomes. MTT assays showed that the cell lines with giant lysosomes were more resistant to sorafenib treatment than those with small lysosomes (p<0.01, and that verapamil incubation can revert this resistance, especially if it is administered after drug pre-incubation. The findings of this study demonstrate the involvement of PGP-positive lysosomes in drug sequestration and MDR in HCC cell lines. The possibility of modulating this mechanism using PGP inhibitors could lead to the development of new targeted strategies to enhance HCC treatment.

  7. Factor V Leiden and Cardiopulmonary Bypass

    Science.gov (United States)

    Uppal, Victor; Rosin, Mark; Marcoux, Jo-Anne; Olson, Marnie; Bezaire, Jennifer; Dalshaug, Gregory

    2015-01-01

    Abstract: We present a case of a patient with factor V Leiden with an antithrombin III activity of 67% who received a successful aortic valve replacement supported by cardiopulmonary bypass (CPB). A safe level of anticoagulation was achieved by monitoring activated clotting time (ACT) and heparin concentration ensuring adequate anticoagulation throughout the procedure. Results from ACT, heparin dose response, heparin protamine titration, and thrombelastography are given. Factor V Leiden patients can be safely anti-coagulated using heparin for CPB procedures when monitored with ACT, heparin protamine titration, and thrombelastography. Postoperative chest tube losses were 360 mL, less than half our institutional average. Anticoagulation for the pre-and post-operative phase is also discussed. PMID:26834284

  8. 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.

  9. Rumen bypass nutrients: Manipulation and implications

    International Nuclear Information System (INIS)

    The feeds available for ruminants in developing countries are either agro-industrial by-products or specially grown forage crops. Many of these feeds are low in protein and require supplementation with non-protein N (NPN) to maintain efficient rumen function and digestibility. The principles for utilizing high energy, low protein feeds by ruminants are discussed in relation to the supply of NPN, the establishment of efficient rumen function, maximizing feed intake by means of supplements, and increasing total energy and protein intake by using supplements which bypass the rumen. To illustrate it the application of these principles to feeding systems based on molasses, chopped whole sugar cane and derinded sugar cane is discussed. The implications of the principles in increasing the feeding value of straw are also discussed. (author)

  10. 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

  11. Innovative Double Bypass Engine for Increased Performance

    Science.gov (United States)

    Manoharan, Sanjivan

    Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Lacrimal bypass surgery in endoscopic dacryocystorhinostomy

    Directory of Open Access Journals (Sweden)

    V. A. Obodov

    2014-01-01

    Full Text Available Background: Optimal placement of dacryostoma and minimally invasive non-traumatic bypass surgery that creates an anastomosis between the lacrimal sac and the nasal cavity are important to prevent the recurrence of nasolacrimal duct obstruction. Aim: To develop a simplified technique of bypass creation. Methods: In addition to optic rhinoendoscopy, virtual endoscopy of lacrimal sac and nasal cavity was performed (n = 15. Virtual endoscopy is based on 3 D computer data processing with subsequent reconstruction of nasal cavity and lacrimal sac visualization. This provides 4 D movement effect mimicking optic endoscopy. Nasal mucosal flap was created using radio-wave Jawad tip, lacrimal sac flap was created through the canal using improved radio-wave tip. Flaps were fixed with Tissucol® bioglue. The whole surgery was performed under the control of video endoscope (Storz. Results: The analysis of virtual endoscopy protocols with visible projection of lacrimal sac on nasal cavity lateral wall enabled to select an optimal place for dacryostoma depending on the size and the placement of lacrimal sac. The use of curved radio-wave Jawad tip made possible to create mucosal periosteal flap in all patients. Transcanalicular radio-wave formation of the flap from lacrimal sac wall was easier and safer than endonasal one. Glue flap fixation was technologically easier than suturing.Conclusion: Radio-wave endoscopic nasal mucosal flap creation, radio-wave transcanalicular lacrimal sac flap creation, and flap gluing are a simple and safe method of anastomosis formation in endoscopic dacryocystorhinoscopy.

  18. CFD Analysis of Core Bypass Phenomena

    International Nuclear Information System (INIS)

    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

  19. 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

  20. 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.

  1. 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

  2. Changes in lysosomal morphology and enzyme activities during the development of adriamycin-induced cardiomyopathy.

    Science.gov (United States)

    Singal, P K; Segstro, R J; Singh, R P; Kutryk, M J

    1985-03-01

    Morphologic and enzymic changes in heart lysosomes were studied following a chronic treatment of animals with a cumulative dose of 15 mg/kg of adriamycin. Myocardial cell damage due to adriamycin included lysosomal changes, sarcotubular swelling, vacuolization and myofibrillar drop-out. These structural changes were more pronounced in the 6-week treated group as opposed to the 3-week treated group. The number of lysosomes per unit area increased from a control value of 3.6 +/- 1.7 to 17.8 +/- 4.0 in the 3-week treated group and 35.9 +/- 9.2 in the 6-week treated groups, respectively. The scatter in the size distribution of lysosomes was much wider in treated animals. Lysosomal hydrolases in the 3-week and 6-week adriamycin-treated group changed as follows: N acetyl beta-glucosaminidase activity fell in the homogenate (H) and nonsedimentable (NS) and rose in the serum (Ser) fractions; a drop in alpha-mannosidase was seen in the sedimentable (S) and Ser fractions; an increase in beta-galactosidase was noted in the H, S and Ser fractions; acid phosphatase was increased in H, S, NS and Ser fractions. Lanthanum staining, used as a cytochemical probe for normal membrane permeability, revealed intracytoplasmic localization of the tracer only in the 6-week group. Malondialdehyde content was increased significantly in the 3-week and 6-weed treated groups. These results show lysosomal changes in adriamycin-treated hearts which precede as well as accompany nonspecific permeability changes in the sarcolemma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3931886

  3. Lysosomal delivery of therapeutic enzymes in cell models of Fabry disease.

    Science.gov (United States)

    Marchesan, D; Cox, T M; Deegan, P B

    2012-11-01

    The success of enzymatic replacement in Gaucher disease has stimulated development of targeted protein replacement for other lysosomal disorders, including Anderson-Fabry disease, which causes fatal cardiac, cerebrovascular and renal injury: deficiency of lysosomal α-Galactosidase A induces accumulation of glycosphingolipids. Endothelial cell storage was the primary endpoint in a clinical trial that led to market authorization. Two α-Galactosidase A preparations are licensed worldwide, but fatal outcomes persist, with storage remaining in many tissues. We compare mechanisms of uptake of α -Galactosidase A into cells relevant to Fabry disease, in order to investigate if the enzyme is targeted to the lysosomes in a mannose-6-phosphate receptor dependent fashion, as generally believed. α -Galactosidase A uptake was examined in fibroblasts, four different endothelial cell models, and hepatic cells in vitro. Uptake of europium-labeled human α -Galactosidase A was measured by time-resolved fluorescence. Ligand-specific uptake was quantified in inhibitor studies. Targeting to the lysosome was determined by precipitation and by confocal microscopy. The quantity and location of cation-independent mannose-6-phosphate receptors in the different cell models were investigated using confocal microscopy. Uptake and delivery of α -Galactosidase A to lysosomes in fibroblasts is mediated by the canonical mannose-6-phosphate receptor pathway, but in endothelial cells in vitro this mechanism does not operate. Moreover, this observation is supported by a striking paucity of expression of cation independent mannose-6-phosphate receptors on the plasma membrane of the four endothelial cell models and by little delivery of enzyme to lysosomes, when compared with fibroblasts. If these observations are confirmed in vivo, alternative mechanisms will be needed to explain the ready clearance of storage from endothelial cells in patients undergoing enzyme replacement therapy. PMID:22450713

  4. 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.

  5. 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.

  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. An adenosine triphosphate-dependent calcium uptake pump in human neutrophil lysosomes.

    OpenAIRE

    Klemper, M S

    1985-01-01

    Regulation of the cytosolic free calcium concentration is important to neutrophil function. In these studies, an ATP-dependent calcium uptake pump has been identified in human neutrophil lysosomes. This energy-dependent Ca++ uptake pump has a high affinity for Ca++ (Michaelis constant [Km] Ca++ = 107 nM) and a maximum velocity (Vmax) of 5.3 pmol/mg of protein per min. ATP was the only nucleotide that supported Ca++ uptake by lysosomes. The Km for ATP was 177 microM. ATP-dependent Ca++ uptake ...

  8. Inhibition of Endosome-Lysosome System Acidification Enhances Porcine Circovirus 2 Infection of Porcine Epithelial Cells▿

    OpenAIRE

    Misinzo, Gerald; Delputte, Peter; Nauwynck, Hans

    2007-01-01

    Recently, Misinzo et al. (G. Misinzo, P. Meerts, M. Bublot, J. Mast, H. M. Weingartl, and H. J. Nauwynck, J. Gen. Virol. 86:2057-2068, 2005) reported that inhibiting endosome-lysosome system acidification reduced porcine circovirus 2 (PCV2) infection of monocytic 3D4/31 cells. The present study examined the effect of inhibiting endosome-lysosome system acidification in epithelial cells, since epithelial cells support PCV2 infection in vivo and are used in culturing PCV2 in vitro. Ammonium chl...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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....

  14. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... to check their blood sugar several times a day. Other problems that patients with morbid obesity have ... a lap band and he’s discharged the next day. With the gastric bypass, the patient comes in ...

  15. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... and are morbidly obese have higher incidents of heart problems. The other things that we see are ... used for multiple surgical procedures. It’s used for heart procedures, the CABG, coronary artery bypass, valve procedures, ...

  16. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... you a detailed account of how the operation works. During that time, I’d like to answer ... you’ll understand it. Basically, the gastric bypass works on two different principals for weight loss, one ...

  17. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... later, there was laparoscopic gastric bypass surgery. The learning curve, which is the time that it takes ... that you can do it proficiently; however the learning curve with robotic surgery is much shorter. In ...

  18. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I ... study in 1991 at the National Institute of Health in Washington, D.C. And what they looked ...

  19. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

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    Full Text Available ... Health South Florida Miami, FL May 20, 2010 I am Dr. Anthony Gonzalez, and welcome to South ... live webcast, a fully robotic gastric bypass, as I mentioned, we’re in the operating room at ...

  20. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... Anthony Gonzalez, and welcome to South Miami Hospital. We’re here for a live webcast, a fully robotic gastric bypass, as I mentioned, we’re in the operating room at South Miami ...

  1. Alveolar proteinosis lung lavage using partial cardiopulmonary bypass.

    OpenAIRE

    Freedman, A P; Pelias, A; Johnston, R F; Goel, I P; Hakki, H I; Oslick, T; Shinnick, J P

    1981-01-01

    An adult case of pulmonary alveolar proteinosis presented with an arterial oxygen tension of 27 mmHg (3.6 kPa) while breathing air. Dangerous hypoxaemia during lung lavage was avoided by using partial cardiopulmonary bypass.

  2. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... The feet are in this direction. And the robot is brought and docked over the patient’s body ... this location where I will be using the robot to perform this fully robotic gastric bypass. So ...

  3. Collider bypass diode thermal simulations and measurements for the SSCL

    Energy Technology Data Exchange (ETDEWEB)

    Rostamzadeh, C.; Tool, G.

    1993-05-01

    Warm bypass diodes will be used as a component of a quench protection system to bypass an exponentially decaying current of 36 sec. time constant and peak current of 7000 A. Temperature excursions due to approximately 252 Kilo Ampere Sec. are studied using ANSYS, a finite element analysis program. A parabolic current waveform of similar energy but higher MIITs (1058 MIIT) was applied to the bypass circuit and temperature excursion was measured at various locations. The procedure of current waveform generation and thermal measurements is illustrated in this paper. A comparison of simulation technique with actual measurements confirms the accuracy of the bypass diode assembly model. This assembly is installed at the SSC half-cell string test facility and results are extremely encouraging.

  4. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... done in two dimensions. Here we have an added dimension, and the depth perception is incredible and ... just a restrictive type of procedure. There’s no combined procedure like with the gastric bypass. So the ...

  5. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I ... robotic prostatectomy, which is probably the standard of care today for prostate cancer. This is our eighth ...

  6. 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....

  7. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass Baptist Health South Florida Miami, FL May 20, 2010 I am Dr. Anthony Gonzalez, and welcome to South Miami Hospital. We’ ...

  8. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... of reinforce this. This has been a really beautiful case. There’s really no bleeding, even though we ... on BAPTISTHEALTH.NET and joining us for this beautiful fully robotic gastric bypass. I hope that Dr. ...

  9. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Medline Plus

    Full Text Available ... Harrisburg Hospital campus. We are going to witness a robot-assisted minimally invasive coronary artery bypass surgery ... you're starting to do and maybe give a little background on the patient's condition? 00:00: ...

  10. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... gastric bypass. So without further adieu, let me send you out, right outside our doors to my ... everything else that’s going into it, it will send the same signal to the brain that you’ ...

  11. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... operative procedure, the live procedure, you’ll understand it. Basically, the gastric bypass works on two different ... a small portion of the stomach and divide it from the rest of the stomach, and that’s ...

  12. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... gastrectomy. Another question is, “Does gastric bypass eliminate diabetes?” The morbidly obese patients that we see are those patients that have diabetes mellitus type II, and that’s diabetes associated with ...

  13. 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...

  14. Value of Optical Bypass in Packet Ring Networks

    Institute of Scientific and Technical Information of China (English)

    Xu Zhu; Qingji Zeng; Fengqing Liu; Xudong Yang; Shilin Xiao

    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.

  15. 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...

  16. 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...

  17. 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

  18. 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.

  19. Electrical failure during cardiopulmonary bypass: a critical moment.

    Science.gov (United States)

    Durukan, Ahmet Baris; Gurbuz, Hasan Alper; Ozcelik, Gokhan; Yorgancioglu, Cem

    2016-06-01

    Electrical failure during cardiopulmonary bypass is a crisis situation for the cardiac surgical team. Fortunately, it has a low incidence with low morbidity and mortality rates. Notwithstanding, institutional preventative and management measures should be taken. Here, we report a case of electrical failure during cardiopulmonary bypass, which was successfully managed during the surgery, allowing the patient to recover uneventfully. These unwanted complications can only be managed by promoting awareness and putting in place strategies against them. PMID:27516788

  20. Controllability and Operability Analysis of Heat Exchanger Networks Including Bypasses

    OpenAIRE

    Hernández, S; Balcazar-López, L.; Sánchez-Márquez, J. A.; González-García, G.

    2010-01-01

    In this paper, the influence of bypasses in heat exchanger networks on theoretical control properties and closed-loop behavior was investigated. According to theoretical control properties obtained using the singular value decomposition technique, the presence of bypasses increases flexibility of the heat exchanger network. This result was corroborated using closed-loop dynamic simulations using a proportional integral controller and a proportional integral controller with dynamic estimati...

  1. 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....

  2. 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.

  3. Prion infection impairs lysosomal degradation capacity by interfering with rab7 membrane attachment in neuronal cells.

    Science.gov (United States)

    Shim, Su Yeon; Karri, Srinivasarao; Law, Sampson; Schatzl, Hermann M; Gilch, Sabine

    2016-01-01

    Prions are proteinaceous infectious particles which cause fatal neurodegenerative disorders in humans and animals. They consist of a mostly β-sheeted aggregated isoform (PrP(Sc)) of the cellular prion protein (PrP(c)). Prions replicate autocatalytically in neurons and other cell types by inducing conformational conversion of PrP(c) into PrP(Sc). Within neurons, PrP(Sc) accumulates at the plasma membrane and in vesicles of the endocytic pathway. To better understand the mechanisms underlying neuronal dysfunction and death it is critical to know the impact of PrP(Sc) accumulation on cellular pathways. We have investigated the effects of prion infection on endo-lysosomal transport. Our study demonstrates that prion infection interferes with rab7 membrane association. Consequently, lysosomal maturation and degradation are impaired. Our findings indicate a mechanism induced by prion infection that supports stable prion replication. We suggest modulation of endo-lysosomal vesicle trafficking and enhancement of lysosomal maturation as novel targets for the treatment of prion diseases. PMID:26865414

  4. Combination Therapies for Lysosomal Storage Diseases: A Complex Answer to a Simple Problem.

    Science.gov (United States)

    Macauley, Shannon L

    2016-06-01

    Abstract Lysosomal storage diseases (LSDs) are a group of 40-50 rare monogenic disorders that result in disrupted lysosomal function and subsequent lysosomal pathology. Depending on the protein or enzyme deficiency associated with each disease, LSDs affect an array of organ systems and elicit a complex set of secondary disease mechanisms that make many of these disorders difficult to fully treat. The etiology of most LSDs is known and the innate biology of lysosomal enzymes favors therapeutic intervention, yet most attempts at treating LSDs with enzyme replacement strategies fall short of being curative. Even with the advent of more sophisticated approaches, like substrate reduction therapy, pharmacologic chaperones, gene therapy or stem cell therapy, comprehensive treatments for LSDs have yet to be achieved. Given the limitations with individual therapies, recent research has focused on using a combination approach to treat LSDs. By coupling protein-, cell-, and gene- based therapies with small molecule drugs, researchers have found greater success in eradicating the clinical features of disease. This review seeks to discuss the positive and negatives of singular therapies used to treat LSDs, and discuss how, in combination, studies have demonstrated a more holistic benefit on pathological and functional parameters. By optimizing routes of delivery, therapeutic timing, and targeting secondary disease mechanisms, combination therapy represents the future for LSD treatment. PMID:27491211

  5. Dietary protein deficiency reduces lysosomal and nonlysosomal ATP-dependent proteolysis in muscle

    Science.gov (United States)

    Tawa, N. E. Jr; Kettelhut, I. C.; Goldberg, A. L.

    1992-01-01

    When rats are fed a protein deficient (PD) diet for 7 days, rates of proteolysis in skeletal muscle decrease by 40-50% (N. E. Tawa, Jr., and A. L. Goldberg. Am. J. Physiol. 263 (Endocrinol. Metab. 26): E317-325, 1992). To identify the underlying biochemical adaptations, we measured different proteolytic processes in incubated muscles. The capacity for intralysosomal proteolysis, as shown by sensitivity to methylamine or lysosomal protease inhibitors, fell 55-75% in muscles from PD rats. Furthermore, extracts of muscles of PD rats showed 30-70% lower activity of many lysosomal proteases, including cathepsins B, H, and C, and carboxypeptidases A and C, as well as other lysosomal hydrolases. The fall in cathepsin B and proteolysis was evident by 3 days on the PD diet, and both returned to control levels 3 days after refeeding of the normal diet. In muscles maintained under optimal conditions, 80-90% of protein breakdown occurs by nonlysosomal pathways. In muscles of PD rats, this ATP-dependent process was also 40-60% slower. Even though overall proteolysis decreased in muscles of PD rats, their capacity for Ca(2+)-dependent proteolysis increased (by 66%), as did the activity of the calpains (+150-250%). Thus the lysosomal and the ATP-dependent processes decrease coordinately and contribute to the fall in muscle proteolysis in PD animals.

  6. Septins promote macropinosome maturation and traffic to the lysosome by facilitating membrane fusion.

    Science.gov (United States)

    Dolat, Lee; Spiliotis, Elias T

    2016-08-29

    Macropinocytosis, the internalization of extracellular fluid and material by plasma membrane ruffles, is critical for antigen presentation, cell metabolism, and signaling. Macropinosomes mature through homotypic and heterotypic fusion with endosomes and ultimately merge with lysosomes. The molecular underpinnings of this clathrin-independent endocytic pathway are largely unknown. Here, we show that the filamentous septin GTPases associate preferentially with maturing macropinosomes in a phosphatidylinositol 3,5-bisphosphate-dependent manner and localize to their contact/fusion sites with macropinosomes/endosomes. Septin knockdown results in large clusters of docked macropinosomes, which persist longer and exhibit fewer fusion events. Septin depletion and overexpression down-regulates and enhances, respectively, the delivery of fluid-phase cargo to lysosomes, without affecting Rab5 and Rab7 recruitment to macropinosomes/endosomes. In vitro reconstitution assays show that fusion of macropinosomes/endosomes is abrogated by septin immunodepletion and function-blocking antibodies and is induced by recombinant septins in the absence of cytosol and polymerized actin. Thus, septins regulate fluid-phase cargo traffic to lysosomes by promoting macropinosome maturation and fusion with endosomes/lysosomes. PMID:27551056

  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. Lysosome vs. mitochondrion as photosensitizer binding site: how does the tortoise overtake the hare?

    Science.gov (United States)

    Oleinick, Nancy L.; Azizuddin, Kashif; Chiu, Song-mao; Joseph, Sheeba; Rodriguez, Myriam E.; Xue, Liang-yan; Zhang, Ping; Kenney, Malcolm E.; Lam, Minh; Nieminen, Anna-Liisa

    2008-02-01

    Pc 4, a photosensitizer first synthesized at Case Western Reserve University and now in clinical trial at University Hospitals Case Medical Center, has been shown to bind preferentially and with high affinity to mitochondrial and endoplasmic reticulum membranes. Upon photoirradiation of Pc 4-loaded cells, membrane components, especially the anti-apoptotic protein Bcl-2, are photodamaged. Apoptosis, as indicated by activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase, is triggered by the initial photodamage. A series of analogues of Pc 4 has been synthesized containing two axial ligands, one identical to the single ligand of Pc 4 and the other either the same as the Pc 4 ligand or bearing one or more hydroxyl groups. The hydroxyl-bearing axial ligands reduce the aggregation of the Pc in polar environments and direct the Pc's to lysosomes. Photoirradiation of cells that have taken up these Pc's into their lysosomes is 4-6 times more efficient at killing cells, as defined by loss of clonogenicity, than with Pc 4. Whereas PDT with Pc 4 photodamages Bcl-2 and Bcl-xL over the same dose response range as for cell killing, PDT with Pc 181 or the other lysosome-localizing Pc's causes much less photodamage to Bcl-2 relative to cell killing. Furthermore, in the case of the lysosome-bound Pc's, little or no caspase-3-dependent apoptosis is observed.

  9. 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

  10. (-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization

    Science.gov (United States)

    LeGendre, Onica; Breslin, Paul AS; Foster, David A

    2015-01-01

    (-)-Oleocanthal (OC), a phenolic compound present in extra-virgin olive oil (EVOO), has been implicated in the health benefits associated with diets rich in EVOO. We investigated the effect of OC on human cancer cell lines in culture and found that OC induced cell death in all cancer cells examined as rapidly as 30 minutes after treatment in the absence of serum. OC treatment of non-transformed cells suppressed their proliferation but did not cause cell death. OC induced both primary necrotic and apoptotic cell death via induction of lysosomal membrane permeabilization (LMP). We provide evidence that OC promotes LMP by inhibiting acid sphingomyelinase (ASM) activity, which destabilizes the interaction between proteins required for lysosomal membrane stability. The data presented here indicate that cancer cells, which tend to have fragile lysosomal membranes compared to non-cancerous cells, are susceptible to cell death induced by lysosomotropic agents. Therefore, targeting lysosomal membrane stability represents a novel approach for the induction of cancer-specific cell death. PMID:26380379

  11. Diagnosing lysosomal storage diseases in a Brazilian non-newborn population by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Guilherme Dotto Brand

    2013-11-01

    Full Text Available OBJECTIVES: High-throughput mass spectrometry methods have been developed to screen newborns for lysosomal storage disorders, allowing the implementation of newborn screening pilot studies in North America and Europe. It is currently feasible to diagnose Pompe, Fabry, Gaucher, Krabbe, and Niemann-Pick A/B diseases, as well as mucopolysaccharidosis I, by tandem mass spectrometry in dried blood spots, which offers considerable technical advantages compared with standard methodologies. We aimed to investigate whether the mass spectrometry methodology for lysosomal storage disease screening, originally developed for newborns, can also discriminate between affected patients and controls of various ages. METHODS: A total of 205 control individuals were grouped according to age and subjected to mass spectrometry quantification of lysosomal α-glucosidase, β-glucocerebrosidase, α-galactosidase, acid sphingomyelinase, galactocerebrosidase, and α−L-iduronidase activities. Additionally, 13 affected patients were analyzed. RESULTS: The median activities for each enzyme and each age group were determined. Enzyme activities were significantly lower in individuals aged older than 18 years compared with those in newborns. Affected patients presented enzymatic activities corresponding to less than 20% of the age-matched controls. CONCLUSIONS: Our data indicate that the mass spectrometry methodology can be used for the screening of lysosomal storage diseases in non-newborn patients. However, for some diseases, such as Fabry and mucopolysaccharidosis I, a combination of biochemical and clinical data may be necessary to achieve accurate diagnoses.

  12. 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.

  13. Gallium and Functionalized-Porphyrins Combine to Form Potential Lysosome-Specific Multimodal Bioprobes.

    Science.gov (United States)

    Pan, Jie; Harriss, Bethany I; Chan, Chi-Fai; Jiang, Lijun; Tsoi, Tik-Hung; Long, Nicholas J; Wong, Wing-Tak; Wong, Wai-Kwok; Wong, Ka-Leung

    2016-07-18

    A water-soluble bimetallic normal ("cold") and radiochemical ("hot") gallium-porphyrin-ruthenium-bipyridine complex (GaporRu-1) has been synthesized by microwave methodology in short reaction times with good (>85%) yields. (68)GaporRu-1 is demonstrated to be a potential multimodal and functional bioprobe for positron emission tomography (PET), lysosome specific optical imaging, and photodynamic therapy. PMID:27355871

  14. Inhibition of lysosomal protease cathepsin D reduces renal fibrosis in murine chronic kidney disease.

    Science.gov (United States)

    Fox, Christopher; Cocchiaro, Pasquale; Oakley, Fiona; Howarth, Rachel; Callaghan, Krystena; Leslie, Jack; Luli, Saimir; Wood, Katrina M; Genovese, Federica; Sheerin, Neil S; Moles, Anna

    2016-01-01

    During chronic kidney disease (CKD) there is a dysregulation of extracellular matrix (ECM) homeostasis leading to renal fibrosis. Lysosomal proteases such as cathepsins (Cts) regulate this process in other organs, however, their role in CKD is still unknown. Here we describe a novel role for cathepsins in CKD. CtsD and B were located in distal and proximal tubular cells respectively in human disease. Administration of CtsD (Pepstatin A) but not B inhibitor (Ca074-Me), in two mouse CKD models, UUO and chronic ischemia reperfusion injury, led to a reduction in fibrosis. No changes in collagen transcription or myofibroblasts numbers were observed. Pepstatin A administration resulted in increased extracellular urokinase and collagen degradation. In vitro and in vivo administration of chloroquine, an endo/lysosomal inhibitor, mimicked Pepstatin A effect on renal fibrosis. Therefore, we propose a mechanism by which CtsD inhibition leads to increased collagenolytic activity due to an impairment in lysosomal recycling. This results in increased extracellular activity of enzymes such as urokinase, triggering a proteolytic cascade, which culminates in more ECM degradation. Taken together these results suggest that inhibition of lysosomal proteases, such as CtsD, could be a new therapeutic approach to reduce renal fibrosis and slow progression of CKD. PMID:26831567

  15. Sorting Nexin 11 Regulates Lysosomal Degradation of Plasma Membrane TRPV3.

    Science.gov (United States)

    Li, Caiyue; Ma, Wenbo; Yin, Shikui; Liang, Xin; Shu, Xiaodong; Pei, Duanqing; Egan, Terrance M; Huang, Jufang; Pan, Aihua; Li, Zhiyuan

    2016-05-01

    The trafficking of ion channels to/from the plasma membrane is considered an important mechanism for cellular activity and an interesting approach for disease therapies. The transient receptor potential vanilloid 3 (TRPV3) ion channel is widely expressed in skin keratinocytes, and its trafficking mechanism to/from the plasma membrane is unknown. Here, we report that the vesicular trafficking protein sorting nexin 11 (SNX11) downregulates the level of the TRPV3 plasma membrane protein. Overexpression of SNX11 causes a decrease in the level of TRPV3 current and TRPV3 plasma membrane protein in TRPV3-transfected HEK293T cells. Subcellular localizations and western blots indicate that SNX11 interacts with TRPV3 and targets it to lysosomes for degradation, which is blocked by the lysosomal inhibitors chloroquine and leupeptin. Both TRPV3 and SNX11 are highly expressed in HaCaT cells. We show that TRPV3 agonists-activated Ca(2+) influxes and the level of native TRPV3 total protein in HaCaT cells are decreased by overexpression of SNX11 and increased by knockdown of SNX11. Our findings reveal that SNX11 promotes the trafficking of TRPV3 from the plasma membrane to lysosomes for degradation via protein-protein interactions, which demonstrates a previously unknown function of SNX11 as a regulator of TRPV3 trafficking from the plasma membrane to lysosomes. PMID:26818531

  16. Neural stem cell transplantation as a therapeutic approach for treating lysosomal storage diseases.

    Science.gov (United States)

    Shihabuddin, Lamya S; Cheng, Seng H

    2011-10-01

    Treating the central nervous system manifestations of subjects with neuropathic lysosomal storage diseases remains a major technical challenge. This is because of the low efficiency by which lysosomal enzymes in systemic circulation are able to traverse the blood brain barrier into the central nervous system. Intracranial transplantation of neural stems cells genetically modified to overexpress the respective deficient enzymes represents a potential approach to addressing this group of diseases. The unique properties of neural stem cells and progenitor cells, such as their ability to migrate to distal sites, differentiate into various cell types and integrate within the host brain without disrupting normal function, making them particularly attractive therapeutic agents. In addition, neural stem cells are amenable to ex vivo propagation and modification by gene transfer vectors. In this regard, transplanted cells can serve not only as a source of lysosomal enzymes but also as a means to potentially repair the injured brain by replenishing the organ with healthy cells and effecting the release of neuroprotective factors. This review discusses some of the well-characterized neural stem cell types and their possible use in treating neuropathic lysosomal storage diseases such as the Niemann Pick A disease.

  17. A Requirement for Bid for Induction of Apoptosis by Photodynamic Therapy with a Lysosome- but not a Mitochondrion-Targeted Photosensitizer

    OpenAIRE

    Chiu, Song-mao; Xue, Liang-Yan; Lam, Minh; Rodriguez, Myriam E.; Zhang, Ping; Kenney, Malcolm E.; Nieminen, Anna-Liisa; Oleinick, Nancy L.

    2010-01-01

    Photodynamic therapy (PDT) with lysosome-targeted photosensitizers induces the intrinsic pathway of apoptosis via the cleavage and activation of the BH3-only protein Bid by proteolytic enzymes released from photo-disrupted lysosomes. To investigate the role of Bid in apoptosis induction and the role of damaged lysosomes on cell killing by lysosome-targeted PDT, we compared the responses of wild type and Bid-knock-out murine embryonic fibroblasts toward a mitochondrion/endoplasmic reticulum-bi...

  18. 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.

  19. 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.

  20. Variations in dietary intake after bypass surgery for obesity. Possible relation to development of fatty liver after jejunoileal bypass

    Energy Technology Data Exchange (ETDEWEB)

    Rogus, J.; Blumenthal, S.A.

    1981-01-01

    Consumption of nutrients and food energy was compared, with concomitant chemical and radiologic measurements of hepatic fat content, preoperatively and postoperatively in 25 patients who underwent gastric or jejunoileal bypass for obesity. Patients in the two operative groups ingested similar quantities of food before surgery. After surgery, caloric intake from all sources decreased in both groups but to a significantly greater extent in the gastric bypass patients. During the first six months postoperatively, the 13 gastric bypass patients showed no changes in hepatic fat content, whereas substantial increases in liver fat uniformly occurred in the 12 patients who had jejunoileal bypasses. It is suggested that dietary carbohydrate may have contributed to the accretion of liver fat in these 12 patients.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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. PMID:26702793

  6. Secretory Lysosomes and Diseases%分泌型溶酶体与疾病

    Institute of Scientific and Technical Information of China (English)

    王俊伟; 周逸蒋; 竺可青

    2011-01-01

    The classical lysosomes contain a variety of hydrolytic enzymes and lipase to decompose proteins and membrane structures and considered as the cellular terminus digestive organelle. The secretory lysosomes are dicovered in certain cell types with the functions of both intracellular digestion and regulatory exocytosis. Rab27a plays a central role in the regulation of the exocytosis of lysosomal proteins. The exocytosis-related gene mutations, particularly in the regulatory proteins, can cause a variety of immune deficiency phenotypes. The ATP released from the astrocytes lysosomes can be used as the transmission signal between neurons and glial cells. The secretory lysosomes also get involved in the invasion and metastasis of cancer cells.%传统意义的溶酶体被认为是细胞内消化途径的终点站,是含有多种水解酶和脂肪酶的细胞器,可以消化蛋白以及膜结构等.某些特殊类型的细胞中存在分泌型溶酶体,它既有胞内消化的功能,又有调节分泌功能.在调节溶酶体胞吐的蛋白质中,Rab27a蛋白起到了核心作用.相关基因特别是控制胞吐的基因突变,可造成各种免疫缺陷综合症.星型胶质细胞溶酶体胞吐释放ATP,在神经元和胶质细胞之间传递信息.分泌型溶酶体还参与了肿瘤细胞浸润、转移的过程.

  7. 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

  8. 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

  9. 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.

  10. Lysosome-associated membrane proteins (LAMPs) regulate intracellular positioning of mitochondria in MC3T3-E1 cells.

    Science.gov (United States)

    Rajapakshe, Anupama R; Podyma-Inoue, Katarzyna A; Terasawa, Kazue; Hasegawa, Katsuya; Namba, Toshimitsu; Kumei, Yasuhiro; Yanagishita, Masaki; Hara-Yokoyama, Miki

    2015-02-01

    The intracellular positioning of both lysosomes and mitochondria meets the requirements of degradation and energy supply, which are respectively the two major functions for cellular maintenance. The positioning of both lysosomes and mitochondria is apparently affected by the nutrient status of the cells. However, the mechanism coordinating the positioning of the organelles has not been sufficiently elucidated. Lysosome-associated membrane proteins-1 and -2 (LAMP-1 and LAMP-2) are highly glycosylated proteins that are abundant in lysosomal membranes. In the present study, we demonstrated that the siRNA-mediated downregulation of LAMP-1, LAMP-2 or their combination enhanced the perinuclear localization of mitochondria, in the pre-osteoblastic cell line MC3T3-E1. On the other hand, in the osteocytic cell line MLO-Y4, in which both the lysosomes and mitochondria originally accumulate in the perinuclear region and mitochondria also fill dendrites, the effect of siRNA of LAMP-1 or LAMP-2 was barely observed. LAMPs are not directly associated with mitochondria, and there do not seem to be any accessory molecules commonly required to recruit the motor proteins to lysosomes and mitochondria. Our results suggest that LAMPs may regulate the positioning of lysosomes and mitochondria. A possible mechanism involving the indirect and context-dependent action of LAMPs is discussed. PMID:25246127

  11. 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.

  12. 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

  13. NLRP3 inflammasome signaling is activated by low-level lysosome disruption but inhibited by extensive lysosome disruption: roles for K+ efflux and Ca2+ influx.

    Science.gov (United States)

    Katsnelson, Michael A; Lozada-Soto, Kristen M; Russo, Hana M; Miller, Barbara A; Dubyak, George R

    2016-07-01

    Nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) is a cytosolic protein that nucleates assembly of inflammasome signaling platforms, which facilitate caspase-1-mediated IL-1β release and other inflammatory responses in myeloid leukocytes. NLRP3 inflammasomes are assembled in response to multiple pathogen- or environmental stress-induced changes in basic cell physiology, including the destabilization of lysosome integrity and activation of K(+)-permeable channels/transporters in the plasma membrane (PM). However, the quantitative relationships between lysosome membrane permeabilization (LMP), induction of increased PM K(+) permeability, and activation of NLRP3 signaling are incompletely characterized. We used Leu-Leu-O-methyl ester (LLME), a soluble lysosomotropic agent, to quantitatively track the kinetics and extent of LMP in relation to NLRP3 inflammasome signaling responses (ASC oligomerization, caspase-1 activation, IL-1β release) and PM cation fluxes in murine bone marrow-derived dendritic cells (BMDCs). Treatment of BMDCs with submillimolar (≤1 mM) LLME induced slower and partial increases in LMP that correlated with robust NLRP3 inflammasome activation and K(+) efflux. In contrast, supramillimolar (≥2 mM) LLME elicited extremely rapid and complete collapse of lysosome integrity that was correlated with suppression of inflammasome signaling. Supramillimolar LLME also induced dominant negative effects on inflammasome activation by the canonical NLRP3 agonist nigericin; this inhibition correlated with an increase in NLRP3 ubiquitination. LMP elicited rapid BMDC death by both inflammasome-dependent pyroptosis and inflammasome-independent necrosis. LMP also triggered Ca(2+) influx, which attenuated LLME-stimulated NLRP3 inflammasome signaling but potentiated LLME-induced necrosis. Taken together, these studies reveal a previously unappreciated signaling network that defines the coupling between LMP, changes

  14. 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).

  15. Invariant Natural Killer T cells are not affected by lysosomal storage in patients with Niemann-Pick disease type C

    OpenAIRE

    Speak, Anneliese O; Platt, Nicholas; Salio, Mariolina; te Vruchte, Danielle Taylor; Smith, David A.; Shepherd, Dawn; Veerapen, Natacha; Besra, Gurdyal; Yanjanin, Nicole M.; Simmons, Louise; Imrie, Jackie; Wraith, James E.; Lachmann, Robin; Hartung, Ralf; Runz, Heiko

    2012-01-01

    Invariant Natural Killer T (iNKT) cells are a specialised subset of T cells that are restricted to the MHC class I like molecule, CD1d. The ligands for iNKT cells are lipids, with the canonical superagonist being α-galactosylceramide, a non-mammalian glycosphingolipid. Trafficking of CD1d through the lysosome is required for the development of murine iNKT cells. Niemann-Pick type C (NPC) disease is a lysosomal storage disorder caused by dysfunction in either of two lysosomal proteins, NPC1 or...

  16. 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

  17. Minimally invasive coronary artery bypass grafting: initial Connecticut experience.

    Science.gov (United States)

    Tellides, G; Maragh, M R; Smith, J M; Kopf, G S; Ezekowitz, M; Remetz, M; Elefteriades, J A

    1997-03-01

    We report the initial Connecticut experience with minimally invasive coronary artery bypass grafting. This procedure allows bypass grafting to the left anterior descending coronary artery utilizing the internal mammary artery as the conduit. The procedure is minimally invasive because it is performed through a mini-thoracotomy incision in the fourth anterior intercostal space and it is conducted without the use of cardiopulmonary bypass. The procedure has been applied to 13 patients operated between February and October 1996. All but one patient selected were poor candidates for conventional coronary artery bypass surgery because of advanced age (6), chronic renal failure/dialysis/kidney transplant (4), redo status with vulnerable grafts (1), severe peripheral vascular disease (6), severe chronic obstructive pulmonary disease (4). All patients survived operation and were discharged in good condition. Mean postoperative intubation time was seven hours and mean hospital stay was 4.5 days despite the very high pre-existing comorbidity of these patients. All patients are alive at the current follow-up time. Two patients required a conventional bypass procedure for occlusion of the minimally invasive graft, the first because of diffuse disease in the target artery and the second attributable to the technical limitations of minimally invasive coronary artery bypass grafting; both tolerated the subsequent procedure well. All patients are now angina-free. All four grafts studied by routine postoperative angiography were widely patent. Routine post-operative exercise nuclear imaging was normal in an additional patient. This procedure of minimally invasive coronary artery bypass grafting offers significant advantages compared to the conventional bypass procedure (short hospital stay, quick recovery, and, especially, avoidance of cerebrovascular accidents caused by the heart-lung machine). This minimally invasive procedure is expected to apply to a growing percentage of

  18. 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.

  19. Transport of radiolabelled glycoprotein to cell surface and lysosome-like bodies of absorptive cells in cultured small-intestinal tissue from normal subjects and patients with a lysosomal storage disease

    International Nuclear Information System (INIS)

    The transport of 3H-fucose and 3H-glucosamine-labelled glycoproteins in the absorptive cells of cultured human small-intestinal tissue was investigated with light- and electron-microscopical autoradiography. The findings showed that these glycoproteins were completed in the Golgi apparatus and transported in small vesicular structures to the apical cytoplasm of these cells. Since this material arrived in the cell coat on the microvilli and in the lysosome-like bodies simultaneously, a crinophagic function of these organelles in the regulation of the transport or secretion of cell-coat material was supported. In the absorptive cells of patients with fucosidosis or Hunter's type of lysosomal storage disease, a similar transport of cell-coat material to the lysosome-like bodies and a congenital defect of a lysosomal hydrolase normally involved in the degradation of cell-coat material, can explain the accumulation of this material in the dense bodies. (orig.)

  20. Lysosome-associated miniSOG as a photosensitizer for mammalian cells.

    Science.gov (United States)

    Ryumina, Alina P; Serebrovskaya, Ekaterina O; Staroverov, Dmitry B; Zlobovskaya, Olga A; Shcheglov, Alexander S; Lukyanov, Sergey A; Lukyanov, Konstantin A

    2016-01-01

    Genetically encoded photosensitizers represent a promising optogenetic tool for the induction of light-controlled oxidative stress strictly localized to a selected intracellular compartment. Here we tested the phototoxic effects of the flavin-containing phototoxic protein miniSOG targeted to the cytoplasmic surfaces of late endosomes and lysosomes by fusion with Rab7. In HeLa Kyoto cells stably expressing miniSOG-Rab7, we demonstrated a high level of cell death upon blue-light illumination. Pepstatin A completely abolished phototoxicity of miniSOG-Rab7, showing a key role for cathepsin D in this model. Using a far-red fluorescence sensor for caspase-3, we observed caspase-3 activation during miniSOG-Rab7-mediated cell death. We conclude that upon illumination, miniSOG-Rab7 induces lysosomal membrane permeabilization (LMP) and leakage of cathepsins into the cytosol, resulting in caspase-dependent apoptosis. PMID:27528074

  1. Three-layer poly(methyl methacrylate) microsystem for analysis of lysosomal enzymes for diagnostic purposes

    DEFF Research Database (Denmark)

    Kwapiszewski, Radoslaw; Kwapiszewska, Karina; Kutter, Jörg P;

    2015-01-01

    Lysosomal storage diseases are chronic, progressive and typically have a devastating impact on the patient and the family. The diagnosis of these diseases is still a challenge, however, even for trained specialists. Accurate diagnostic methods and high-throughput tools that could be readily...... incorporated into existing screening laboratories are urgently required. We propose a new method for measuring the activity of lysosomal enzymes using a microfluidic device. The principle of the method is the fluorometric determination of a protonated form of 4-methylumbelliferone directly in the enzymatic...... simplified analytical procedure and a significantly shortened processing time. We measured the activity of β-galactosidase in RPMI-1788 human B lymphocytes and in isolated leukocytes from healthy adults. The method shows a good agreement with the standard diagnostic method. The agreement was confirmed...

  2. 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

    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...... 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...... 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...

  3. 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 aggregates are an early and progressive pathology that occur at 3 months of age and increase in both size and number over time. These autofluorescent aggregates are not observed in mice expressing wild-type CHMP2B, or in non-transgenic controls, indicating that they are a specific pathology caused by mutant...... in human CHMP2B mutation brain than in neurodegenerative disease or age-matched control brains. These data suggest that lysosomal storage pathology is the major neuronal pathology in FTD caused by CHMP2B mutation. Recent evidence suggests that two other genes associated with FTD, GRN and TMEM106B...

  4. Role of phospholipids in destabilization of lysosomal membranes in chronic alcohol poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Tadevosyan, Y.V.; Batikyan, T.B.; Gevorkyan, G.A.; Karagezyan, K.G.

    1986-04-01

    The aim of this investigation was to study changes in the phospholipids (PL) spectrum and possible activity of membrane-bound phospholipase A/sub 2/ in lysosomal membranes from albino rat liver under conditions of the normally metabolizing tissue and during long-term alcohol poisoning. Changes in stability of the lysosomal membranes were determined by measuring nonsedimented acid phosphatase (AP) activity. The substance 1-acyl-2-(1-/sup 14/C)-oleoyl-phosphatidyl-choline (/sup 14/C-PCh) was synthesized by an enzymic method. Phospholipase A/sub 2/ activity was determined in an incubation medium of Tris-Maleate buffer containing 20 nanomoles (/sup 14/C)-PCH, 8 mM CaC1/sub 2/, and about 100 micrograms protein.

  5. 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.

  6. 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...... more often than patients operated on for intermittent claudication, 10 and 3 respectively (p=0.003), and had higher mortality rates, 20% and 8% respectively (p=0.001). CONCLUSION: This trial confirms that Dacron is at least as durable as PTFE for above-knee bypass procedures, and might even be superior....

  7. Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy

    DEFF Research Database (Denmark)

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

    2005-01-01

    AIMS/HYPOTHESIS: Postprandial hypoglycaemia following gastric bypass for obesity is considered a late manifestation of the dumping syndrome and can usually be managed with dietary modification. We investigated three patients with severe postprandial hypoglycaemia and hyperinsulinaemia unresponsive...... 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...... of neuroglycopenia; pancreas pathology of all patients revealed diffuse islet hyperplasia and expansion of beta cell mass. CONCLUSIONS/INTERPRETATION: These findings suggest that gastric bypass-induced weight loss may unmask an underlying beta cell defect or contribute to pathological islet hyperplasia, perhaps via...

  8. 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.

  9. Mucopolysaccharidosis IIIB, a lysosomal storage disease, triggers a pathogenic CNS autoimmune response

    OpenAIRE

    Popovich Phillip G; Divers Erin; DiRosario Julianne; Killedar Smruti; McCarty Douglas M; Fu Haiyan

    2010-01-01

    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 ...

  10. WASH is required for lysosomal recycling and efficient autophagic and phagocytic digestion

    OpenAIRE

    King, Jason S.; Gueho, Aurélie; Hagedorn, Monica; Gopaldass, Navin Andréw; Leuba, Florence; Soldati, Thierry; Insall, Robert H.

    2013-01-01

    Wiskott-Aldrich syndrome protein and SCAR homologue (WASH) is an important regulator of vesicle trafficking. By generating actin on the surface of intracellular vesicles, WASH is able to directly regulate endosomal sorting and maturation. We report that, in Dictyostelium, WASH is also required for the lysosomal digestion of both phagocytic and autophagic cargo. Consequently, Dictyostelium cells lacking WASH are unable to grow on many bacteria or to digest their own cytoplasm to survive starva...

  11. 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.

  12. PHOSPHATIDYLINOSITOL 3,5-BISPHOSPHATE IS AN ESSENTIAL REGULATOR OF LYSOSOME MORPHOLOGY

    OpenAIRE

    Asanuma, Ken; Takasuga, Shunsuke; Sasaki, Junko; Sasaki, Takehiko

    2013-01-01

    Phosphoinositides are lipid second messengers that act as key players in endosomal membrane trafficking, and mutations in several phosphatases that metabolize these lipids cause severe genetic diseases. We previously reported that type III phosphatidylinositol phosphate kinase (PIPKIII) is a critical regulator of lysosome size. However, the lipid products that mediate PIPKIII function have not been well characterized. Using a series of phosphoinositide phosphatase expression vectors, we show ...

  13. Alteration of Dynein Function Affects α-Synuclein Degradation via the Autophagosome-Lysosome Pathway

    OpenAIRE

    Da Li; Ji-Jun Shi; Cheng-Jie Mao; Sha Liu; Jian-Da Wang; Jing Chen; Fen Wang; Ya-Ping Yang; Wei-Dong Hu; Li-Fang Hu; Chun-Feng Liu

    2013-01-01

    Growing evidence suggests that dynein dysfunction may be implicated in the pathogenesis of neurodegeneration. It plays a central role in aggresome formation, the delivery of autophagosome to lysosome for fusion and degradation, which is a pro-survival mechanism essential for the bulk degradation of misfolded proteins and damaged organells. Previous studies reported that dynein dysfuntion was associated with aberrant aggregation of α-synuclein, which is a major component of inclusion bodies in...

  14. OXIDATIVE STRESS TRIGGERS CA2+-DEPENDENT LYSOSOME TRAFFICKING AND ACTIVATION OF ACID SPHINGOMYELINASE

    OpenAIRE

    Li, Xiang; Gulbins, Erich; Zhang, Yang

    2012-01-01

    Recent studies demonstrate that rapid translocation of the acid sphingomyelinase (ASM), a lysosomal hydrolase, to the outer leaflet of the cell membrane and concomitant release of ceramide constitute a common cellular signaling cascade to various stimuli including CD95 ligation, UV-irradiation, bacterial and viral infections. Reactive oxygen species (ROS) were shown to play a crucial role in regulating this signaling cascade at least for some bacterial infections and UV-irradiation. However, ...

  15. Possible Existence of Lysosome-Like Organella within Mitochondria and Its Role in Mitochondrial Quality Control

    OpenAIRE

    Yuji Miyamoto; Noriaki Kitamura; Yasuyuki Nakamura; Manabu Futamura; Takafumi Miyamoto; Masaki Yoshida; Masaya Ono; Shizuko Ichinose; Hirofumi Arakawa

    2011-01-01

    The accumulation of unhealthy mitochondria results in mitochondrial dysfunction, which has been implicated in aging, cancer, and a variety of degenerative diseases. However, the mechanism by which mitochondrial quality is regulated remains unclear. Here, we show that Mieap, a novel p53-inducible protein, induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control. Mieap expression is directly regulated by p53 and is frequently lost in human c...

  16. Protein breakdown in muscle wasting: Role of autophagy-lysosome and ubiquitin-proteasome

    OpenAIRE

    Sandri, Marco

    2013-01-01

    Skeletal muscle adapts its mass as consequence of physical activity, metabolism and hormones. Catabolic conditions or inactivity induce signaling pathways that regulate the process of muscle loss. Muscle atrophy in adult tissue occurs when protein degradation rates exceed protein synthesis. Two major protein degradation pathways, the ubiquitin-proteasome and the autophagy-lysosome systems, are activated during muscle atrophy and variably contribute to the loss of muscle mass. These degradatio...

  17. Vacuolin-1 potently and reversibly inhibits autophagosome-lysosome fusion by activating RAB5A

    OpenAIRE

    Lu, Yingying; Dong, Shichen; Hao, Baixia; Li, Chang; Zhu, Kaiyuan; Guo, Wenjing; Wang, Qian; Cheung, King-Ho; Wong, Connie WM; Wu, Wu-Tian; Markus, Huss; Yue, Jianbo

    2014-01-01

    Autophagy is a catabolic lysosomal degradation process essential for cellular homeostasis and cell survival. Dysfunctional autophagy has been associated with a wide range of human diseases, e.g., cancer and neurodegenerative diseases. A large number of small molecules that modulate autophagy have been widely used to dissect this process and some of them, e.g., chloroquine (CQ), might be ultimately applied to treat a variety of autophagy-associated human diseases. Here we found that vacuolin-1...

  18. 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.

  19. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    International Nuclear Information System (INIS)

    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

  20. 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.

  1. Relative acidic compartment volume as a lysosomal storage disorder–associated biomarker

    OpenAIRE

    te Vruchte, Danielle; Speak, Anneliese O; Wallom, Kerri L.; Al Eisa, Nada; Smith, David A.; Hendriksz, Christian J.; Simmons, Louise; Lachmann, Robin H.; Cousins, Alison; Hartung, Ralf; Mengel, Eugen; Runz, Heiko; Beck, Michael; Amraoui, Yasmina; Imrie, Jackie

    2014-01-01

    Lysosomal storage disorders (LSDs) occur at a frequency of 1 in every 5,000 live births and are a common cause of pediatric neurodegenerative disease. The relatively small number of patients with LSDs and lack of validated biomarkers are substantial challenges for clinical trial design. Here, we evaluated the use of a commercially available fluorescent probe, Lysotracker, that can be used to measure the relative acidic compartment volume of circulating B cells as a potentially universal bioma...

  2. 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.

  3. New biotechnological and nanomedicine strategies for treatment of lysosomal storage disorders

    OpenAIRE

    Muro, Silvia

    2010-01-01

    This review discusses the multiple bio- and nano-technological strategies developed in the last few decades for treatment of a group of fatal genetic diseases, termed lysosomal storage disorders. Some basic foundation on the biomedical causes and social and clinical relevance of these diseases is provided. Several treatment modalities, from those currently available to novel therapeutic approaches under development, are also discussed; these include gene and cell therapies, substrate reductio...

  4. 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.

  5. Glutathione transferase mu 2 protects glioblastoma cells against aminochrome toxicity by preventing autophagy and lysosome dysfunction

    Science.gov (United States)

    Huenchuguala, Sandro; Muñoz, Patricia; Zavala, Patricio; Villa, Mónica; Cuevas, Carlos; Ahumada, Ulises; Graumann, Rebecca; Nore, Beston F; Couve, Eduardo; Mannervik, Bengt; Paris, Irmgard; Segura-Aguilar, Juan

    2014-01-01

    U373MG cells constitutively express glutathione S-transferase mu 2 (GSTM2) and exhibit 3H-dopamine uptake, which is inhibited by 2 µM of nomifensine and 15 µM of estradiol. We generated a stable cell line (U373MGsiGST6) expressing an siRNA against GSTM2 that resulted in low GSTM2 expression (26% of wild-type U373MG cells). A significant increase in cell death was observed when U373MGsiGST6 cells were incubated with 50 µM purified aminochrome (18-fold increase) compared with wild-type cells. The incubation of U373MGsiGST6 cells with 75 µM aminochrome resulted in the formation of autophagic vacuoles containing undigested cellular components, as determined using transmission electron microscopy. A significant increase in autophagosomes was determined by measuring endogenous LC3-II, a significant decrease in cell death was observed in the presence of bafilomycin A1, and a significant increase in cell death was observed in the presence of trehalose. A significant increase in LAMP2 immunostaining was observed, a significant decrease in bright red fluorescence of lysosomes with acridine orange was observed, and bafilomycin A1 pretreatment reduced the loss of lysosome acidity. A significant increase in cell death was observed in the presence of lysosomal protease inhibitors. Aggregation of TUBA/α-tubulin (tubulin, α) and SQSTM1 protein accumulation were also observed. Moreover, a significant increase in the number of lipids droplets was observed compared with U373MG cells with normal expression of GSTM2. These results support the notion that GSTM2 is a protective enzyme against aminochrome toxicity in astrocytes and that aminochrome cell death in U373MGsiGST6 cells involves autophagic-lysosomal dysfunction. PMID:24434817

  6. Lysosomal trafficking of β-catenin induced by the tea polyphenol epigallocatechin-3-gallate

    International Nuclear Information System (INIS)

    β-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 β-catenin, since this provides an avenue for the prevention of colorectal and other cancers in which β-catenin is frequently over-expressed. We show here that physiologically relevant concentrations of the tea polyphenol epigallocatechin-3-gallate (EGCG) inhibited β-catenin/TCF-dependent reporter activity in human embryonic kidney 293 cells transfected with wild type or mutant β-catenins, and there was a corresponding decrease in β-catenin protein levels in the nuclear, cytosolic and membrane-associated fractions. However, β-catenin accumulated as punctate aggregates in response to EGCG treatment, including in human colon cancer cells over-expressing β-catenin endogenously. Confocal microscopy studies revealed that the aggregated β-catenin in HEK293 cells was extra-nuclear and co-localized with lysosomes, suggesting that EGCG activated a pathway involving lysosomal trafficking of β-catenin. Lysosomal inhibitors leupeptin and transepoxysuccinyl-L-leucylamido(4-guanido)butane produced an increase in β-catenin protein in total cell lysates, without a concomitant increase in β-catenin transcriptional activity. These data provide the first evidence that EGCG facilitates the trafficking of β-catenin into lysosomes, presumably as a mechanism for sequestering β-catenin and circumventing further nuclear transport and activation of β-catenin/TCF/LEF signaling

  7. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

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    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.

  8. Activity of lysosomal and mitochondrial ferments in serum and liver tissue at controlled and treated by leukotitin animals

    International Nuclear Information System (INIS)

    In this chapter author describes the experiments on rats and gives the information on activity of lysosomal and mitochondrial ferments in serum and liver tissue at controlled and treated by leukotitin animals

  9. 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

  10. Hormonal and cholinergic influences on pancreatic lysosomal and digestive enzymes in rats.

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    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.

  11. 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.

  12. BNIP3 and NIX mediate Mieap-induced accumulation of lysosomal proteins within mitochondria.

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    Yasuyuki Nakamura

    Full Text Available Mieap, a p53-inducible protein, controls mitochondrial quality by repairing unhealthy mitochondria. During repair, Mieap induces the accumulation of intramitochondrial lysosomal proteins (designated MALM for Mieap-induced accumulation of lysosome-like organelles within mitochondria by interacting with NIX, leading to the elimination of oxidized mitochondrial proteins. Here, we report that an additional mitochondrial outer membrane protein, BNIP3, is also involved in MALM. BNIP3 interacts with Mieap in a reactive oxygen species (ROS-dependent manner via the BH3 domain of BNIP3 and the coiled-coil domains of Mieap. The knockdown of endogenous BNIP3 expression severely inhibited MALM. Although the overexpression of either BNIP3 or NIX did not cause a remarkable change in the mitochondrial membrane potential (MMP, the co-expression of all three exogenous proteins, Mieap, BNIP3 and NIX, caused a dramatic reduction in MMP, implying that the physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may regulate the opening of a pore in the mitochondrial double membrane. This effect was not related to cell death. These results suggest that two mitochondrial outer membrane proteins, BNIP3 and NIX, mediate MALM in order to maintain mitochondrial integrity. The physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may play a critical role in the translocation of lysosomal proteins from the cytoplasm to the mitochondrial matrix.

  13. 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.

  14. 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.

  15. [Structuro-functional changes in dog liver and regional lymph node lysosomes in toxic hepatitis].

    Science.gov (United States)

    Borodin, Iu I; Korolenko, T A; Malygin, A E; Pupyshev, A B; Sharaĭkina, E O

    1978-10-01

    Structural and functional changes in the dog liver and regional lymph nodes lysosomes were studied during toxic hepatitis induced by CCl4 administration (single and repeated). Total activity of lysosomal enzymes (acid RNA-ase and beta-galactosidase) was higher in the regional lymph nodes than in the liver, reflecting the barrier, protective function of the organ. During acute toxic hepatitis the specific activities of acid RNA-ase and cathepsin D displayed a sharp rise. No normalization of the indices under study occurred during the observation period (from 8 to 30 days). At the same time there was a rise of the regional lymph node weight and an elevation of the relative macrophage and neutrophil content in the sinuses. The increased activity of the lysosome enzymes in the regional lymph nodes in injury of the liver was connected with greater functional load on the lymph nodes effecting hydrolysis of biopolymeres which penetrated into the regional lymphatic node with the lymph. PMID:708870

  16. Prevention of lysosomal storage diseases and derivation of mutant stem cell lines by preimplantation genetic diagnosis.

    Science.gov (United States)

    Altarescu, Gheona; Beeri, Rachel; Eiges, Rachel; Epsztejn-Litman, Silvina; Eldar-Geva, Talia; Elstein, Deborah; Zimran, Ari; Margalioth, Ehud J; Levy-Lahad, Ephrat; Renbaum, Paul

    2012-01-01

    Preimplantation genetic diagnosis (PGD) allows birth of unaffected children for couples at risk for a genetic disorder. We present the strategy and outcome of PGD for four lysosomal storage disorders (LSD): Tay-Sachs disease (TSD), Gaucher disease (GD), Fabry disease (FD), and Hunter syndrome (HS), and subsequent development of stem cell lines. For each disease, we developed a family-specific fluorescent multiplex single-cell PCR protocol that included the familial mutation and informative markers surrounding the mutation. Embryo biopsy and PGD analysis were performed on either oocytes (polar bodies one and two) or on single blastomeres from a six-cell embryo. We treated twenty families carrying mutations in these lysosomal storage disorders, including 3 couples requiring simultaneous analysis for two disorders (TSD/GD, TSD/balanced Robertsonian translocation 45XYder(21;14), and HS/oculocutaneus albinism). These analyses led to an overall pregnancy rate/embryo transfer of 38% and the birth of 20 unaffected children from 17 families. We have found that PGD for lysosomal disorders is a safe and effective method to prevent birth of affected children. In addition, by using mutant embryos for the derivation of stem cell lines, we have successfully established GD and HS hESC lines for use as valuable models in LSD research. PMID:23320174

  17. Lysosomal storage of oligosaccharide and glycosphingolipid in imino sugar treated cells.

    Science.gov (United States)

    Boomkamp, Stephanie D; Rountree, J S Shane; Neville, David C A; Dwek, Raymond A; Fleet, George W J; Butters, Terry D

    2010-04-01

    Sandhoff and Tay-Sachs disease are autosomal recessive GM2 gangliosidoses where a deficiency of lysosomal beta-hexosaminidase results in storage of glycoconjugates. Imino sugar (2-acetamido-1,4-imino-1,2,4-trideoxy-L-arabinitol) inhibition of beta-hexosaminidase in murine RAW264.7 macrophage-like cells led to lysosomal storage of glycoconjugates that were characterised structurally using fluorescence labelling of the free or glycolipid-derived oligosaccharides followed by HPLC and mass spectrometry. Stored glycoconjugates were confirmed as containing non-reducing GlcNAc or GalNAc residues resulting from the incomplete degradation of N-linked glycoprotein oligosaccharide and glycolipids, respectively. When substrate reduction therapeutics N-butyl-deoxynojirimycin (NB-DNJ) or N-butyldeoxygalactonojirimycin (NB-DGJ) were applied to the storage phenotype cells, an increase in glucosylated and galactosylated oligosaccharide species was observed due to endoplasmic reticulum alpha-glucosidases and lysosomal beta-galactosidase inhibition, respectively. Hexosaminidase inhibition triggered a tightly regulated cytokine-mediated inflammatory response that was normalised using imino sugars NB-DNJ and NB-DGJ, which restored the GM2 ganglioside storage burden but failed to reduce the levels of GA2 glycolipid or glycoprotein-derived N-linked oligosaccharides. Using a chemically induced gangliosidosis phenotype that can be modulated with substrate lowering drugs, the critical role of GM2 ganglioside in the progression of inflammatory disease is also demonstrated. PMID:20186478

  18. Prevention of Lysosomal Storage Diseases and Derivation of Mutant Stem Cell Lines by Preimplantation Genetic Diagnosis

    Directory of Open Access Journals (Sweden)

    Gheona Altarescu

    2012-01-01

    Full Text Available Preimplantation genetic diagnosis (PGD allows birth of unaffected children for couples at risk for a genetic disorder. We present the strategy and outcome of PGD for four lysosomal storage disorders (LSD: Tay-Sachs disease (TSD, Gaucher disease (GD, Fabry disease (FD, and Hunter syndrome (HS, and subsequent development of stem cell lines. For each disease, we developed a family-specific fluorescent multiplex single-cell PCR protocol that included the familial mutation and informative markers surrounding the mutation. Embryo biopsy and PGD analysis were performed on either oocytes (polar bodies one and two or on single blastomeres from a six-cell embryo. We treated twenty families carrying mutations in these lysosomal storage disorders, including 3 couples requiring simultaneous analysis for two disorders (TSD/GD, TSD/balanced Robertsonian translocation 45XYder(21;14, and HS/oculocutaneus albinism. These analyses led to an overall pregnancy rate/embryo transfer of 38% and the birth of 20 unaffected children from 17 families. We have found that PGD for lysosomal disorders is a safe and effective method to prevent birth of affected children. In addition, by using mutant embryos for the derivation of stem cell lines, we have successfully established GD and HS hESC lines for use as valuable models in LSD research.

  19. Inflammatory cytokine response to Bacillus anthracis peptidoglycan requires phagocytosis and lysosomal trafficking.

    Science.gov (United States)

    Iyer, Janaki K; Khurana, Taruna; Langer, Marybeth; West, Christopher M; Ballard, Jimmy D; Metcalf, Jordan P; Merkel, Tod J; Coggeshall, K Mark

    2010-06-01

    During advanced stages of inhalation anthrax, Bacillus anthracis accumulates at high levels in the bloodstream of the infected host. This bacteremia leads to sepsis during late-stage anthrax; however, the mechanisms through which B. anthracis-derived factors contribute to the pathology of infected hosts are poorly defined. Peptidoglycan, a major component of the cell wall of Gram-positive bacteria, can provoke symptoms of sepsis in animal models. We have previously shown that peptidoglycan of B. anthracis can induce the production of proinflammatory cytokines by cells in human blood. Here, we show that biologically active peptidoglycan is shed from an active culture of encapsulated B. anthracis strain Ames in blood. Peptidoglycan is able to bind to surfaces of responding cells, and internalization of peptidoglycan is required for the production of inflammatory cytokines. We also show that the peptidoglycan traffics to lysosomes, and lysosomal function is required for cytokine production. We conclude that peptidoglycan of B. anthracis is initially bound by an unknown extracellular receptor, is phagocytosed, and traffics to lysosomes, where it is degraded to a product recognized by an intracellular receptor. Binding of the peptidoglycan product to the intracellular receptor causes a proinflammatory response. These findings provide new insight into the mechanism by which B. anthracis triggers sepsis during a critical stage of anthrax disease. PMID:20308305

  20. Lack of the Lysosomal Membrane Protein, GLMP, in Mice Results in Metabolic Dysregulation in Liver.

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    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.

  1. Alpha-synuclein induces lysosomal rupture and cathepsin dependent reactive oxygen species following endocytosis.

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    David Freeman

    Full Text Available α-synuclein dysregulation is a critical aspect of Parkinson's disease pathology. Recent studies have observed that α-synuclein aggregates are cytotoxic to cells in culture and that this toxicity can be spread between cells. However, the molecular mechanisms governing this cytotoxicity and spread are poorly characterized. Recent studies of viruses and bacteria, which achieve their cytoplasmic entry by rupturing intracellular vesicles, have utilized the redistribution of galectin proteins as a tool to measure vesicle rupture by these organisms. Using this approach, we demonstrate that α-synuclein aggregates can induce the rupture of lysosomes following their endocytosis in neuronal cell lines. This rupture can be induced by the addition of α-synuclein aggregates directly into cells as well as by cell-to-cell transfer of α-synuclein. We also observe that lysosomal rupture by α-synuclein induces a cathepsin B dependent increase in reactive oxygen species (ROS in target cells. Finally, we observe that α-synuclein aggregates can induce inflammasome activation in THP-1 cells. Lysosomal rupture is known to induce mitochondrial dysfunction and inflammation, both of which are well established aspects of Parkinson's disease, thus connecting these aspects of Parkinson's disease to the propagation of α-synuclein pathology in cells.

  2. Alpha Adrenergic Induction of Transport of Lysosomal Enzyme across the Blood-Brain Barrier.

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    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.

  3. 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.

  4. A Contiguous Compartment Functions as Endoplasmic Reticulum and Endosome/Lysosome in Giardia lamblia▿ †

    Science.gov (United States)

    Abodeely, Marla; DuBois, Kelly N.; Hehl, Adrian; Stefanic, Sasa; Sajid, Mohammed; deSouza, Wanderley; Attias, Marcia; Engel, Juan C.; Hsieh, Ivy; Fetter, Richard D.; McKerrow, James H.

    2009-01-01

    The dynamic evolution of organelle compartmentalization in eukaryotes and how strictly compartmentalization is maintained are matters of ongoing debate. While the endoplasmic reticulum (ER) is classically envisioned as the site of protein cotranslational translocation, it has recently been proposed to have pluripotent functions. Using transfected reporter constructs, organelle-specific markers, and functional enzyme assays, we now show that in an early-diverging protozoan, Giardia lamblia, endocytosis and subsequent degradation of exogenous proteins occur in the ER or in an adjacent and communicating compartment. The Giardia endomembrane system is simple compared to those of typical eukaryotes. It lacks peroxisomes, a classical Golgi apparatus, and canonical lysosomes. Giardia orthologues of mammalian lysosomal proteases function within an ER-like tubulovesicular compartment, which itself can dynamically communicate with clathrin-containing vacuoles at the periphery of the cell to receive endocytosed proteins. These primitive characteristics support Giardia's proposed early branching and could serve as a model to study the compartmentalization of endocytic and lysosomal functions into organelles distinct from the ER. This system also may have functional similarity to the retrograde transport of toxins and major histocompatibility complex class I function in the ER of mammals. PMID:19749174

  5. A contiguous compartment functions as endoplasmic reticulum and endosome/lysosome in Giardia lamblia.

    Science.gov (United States)

    Abodeely, Marla; DuBois, Kelly N; Hehl, Adrian; Stefanic, Sasa; Sajid, Mohammed; DeSouza, Wanderley; Attias, Marcia; Engel, Juan C; Hsieh, Ivy; Fetter, Richard D; McKerrow, James H

    2009-11-01

    The dynamic evolution of organelle compartmentalization in eukaryotes and how strictly compartmentalization is maintained are matters of ongoing debate. While the endoplasmic reticulum (ER) is classically envisioned as the site of protein cotranslational translocation, it has recently been proposed to have pluripotent functions. Using transfected reporter constructs, organelle-specific markers, and functional enzyme assays, we now show that in an early-diverging protozoan, Giardia lamblia, endocytosis and subsequent degradation of exogenous proteins occur in the ER or in an adjacent and communicating compartment. The Giardia endomembrane system is simple compared to those of typical eukaryotes. It lacks peroxisomes, a classical Golgi apparatus, and canonical lysosomes. Giardia orthologues of mammalian lysosomal proteases function within an ER-like tubulovesicular compartment, which itself can dynamically communicate with clathrin-containing vacuoles at the periphery of the cell to receive endocytosed proteins. These primitive characteristics support Giardia's proposed early branching and could serve as a model to study the compartmentalization of endocytic and lysosomal functions into organelles distinct from the ER. This system also may have functional similarity to the retrograde transport of toxins and major histocompatibility complex class I function in the ER of mammals. PMID:19749174

  6. Rotenone Upregulates Alpha-Synuclein and Myocyte Enhancer Factor 2D Independently from Lysosomal Degradation Inhibition

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    Gessica Sala

    2013-01-01

    Full Text Available Dysfunctions of chaperone-mediated autophagy (CMA, the main catabolic pathway for alpha-synuclein, have been linked to the pathogenesis of Parkinson’s disease (PD. Since till now there is limited information on how PD-related toxins may affect CMA, in this study we explored the effect of mitochondrial complex I inhibitor rotenone on CMA substrates, alpha-synuclein and MEF2D, and effectors, lamp2A and hsc70, in a human dopaminergic neuroblastoma SH-SY5Y cell line. Rotenone induced an upregulation of alpha-synuclein and MEF2D protein levels through the stimulation of their de novo synthesis rather than through a reduction of their CMA-mediated degradation. Moreover, increased MEF2D transcription resulted in higher nuclear protein levels that exert a protective role against mitochondrial dysfunction and oxidative stress. These results were compared with those obtained after lysosome inhibition with ammonium chloride. As expected, this toxin induced the cytosolic accumulation of both alpha-synuclein and MEF2D proteins, as the result of the inhibition of their lysosome-mediated degradation, while, differently from rotenone, ammonium chloride decreased MEF2D nuclear levels through the downregulation of its transcription, thus reducing its protective function. These results highlight that rotenone affects alpha-synuclein and MEF2D protein levels through a mechanism independent from lysosomal degradation inhibition.

  7. Role of Nanotechnology for Enzyme Replacement Therapy in Lysosomal Diseases. A Focus on Gaucher's Disease.

    Science.gov (United States)

    Martín-Banderas, L; Holgado, M A; Durán-Lobato, M; Infante, J J; Álvarez-Fuentes, J; Fernández-Arévalo, M

    2016-01-01

    Lysosomal storage diseases (LSDs) comprise a group of rare inherited chronic syndromes that cause deficiency of specific native enzymes within the lysosomes. The macromolecular compounds that are usually catabolized by lysosomal enzymes are accumulated within these organelles, causing progressive damage to tissues, skeleton and organs and, in several cases, the central nervous system (CNS). The damage caused by substrate accumulation finally results in physical deterioration, functional impairment and potential death. Up to date, the most promising therapy for most LSDs is enzyme-replacement therapy (ERT), which provides patients with the corresponding active enzyme. However, these enzymes do not have enough stability in blood, the treatment must be therefore periodically administrated by i.v. infusion under medical supervision, and immunogenicity issues are frequent. In addition, affected areas within the CNS, where the blood-brain barrier (BBB) is a major obstacle, cannot be reached by the enzymes. Nanotechnology can provide useful carriers to successfully protect and preserve enzymes, and transport them through the BBB towards brain locations. Several strategies based on targeting specific receptors on the BBB have led to nanoparticles that successfully carry sensitive molecules to the brain. Then, the main LSDs are described and a thorough review of nanotechnology strategies for brain delivery studied up to date is presented. PMID:26860997

  8. The Deubiquitinating Enzyme UBPY Is Required for Lysosomal Biogenesis and Productive Autophagy in Drosophila.

    Directory of Open Access Journals (Sweden)

    Anne-Claire Jacomin

    Full Text Available Autophagy is a catabolic process that delivers cytoplasmic components to the lysosomes. Protein modification by ubiquitination is involved in this pathway: it regulates the stability of autophagy regulators such as BECLIN-1 and it also functions as a tag targeting specific substrates to autophagosomes. In order to identify deubiquitinating enzymes (DUBs involved in autophagy, we have performed a genetic screen in the Drosophila larval fat body. This screen identified Uch-L3, Usp45, Usp12 and Ubpy. In this paper, we show that Ubpy loss of function results in the accumulation of autophagosomes due to a blockade of the autophagy flux. Furthermore, analysis by electron and confocal microscopy of Ubpy-depleted fat body cells revealed altered lysosomal morphology, indicating that Ubpy inactivation affects lysosomal maintenance and/or biogenesis. Lastly, we have shown that shRNA mediated inactivation of UBPY in HeLa cells affects autophagy in a different way: in UBPY-depleted HeLa cells autophagy is deregulated.

  9. Cellular uptake of saposin (SAP) precursor and lysosomal delivery by the low density lipoprotein receptor-related protein (LRP).

    OpenAIRE

    Hiesberger, T; Hüttler, S; Rohlmann, A; Schneider, W; Sandhoff, K.; Herz, J.

    1998-01-01

    Sphingolipid activator proteins SAP-A, -B, -C and -D (also called saposins) are generated by proteolytic processing from a 73 kDa precursor and function as obligatory activators of lysosomal enzymes involved in glycosphingolipid metabolism. Although the SAP precursor can be recognized by the mannose-6-phosphate (M-6-P) receptor and shuttled directly from the secretory pathway to the lysosome, a substantial fraction of newly synthesized precursor is secreted from the cell where it may particip...

  10. Distinct Mechanisms of Ferritin Delivery to Lysosomes in Iron-Depleted and Iron-Replete Cells ▿

    OpenAIRE

    Asano, Takeshi; Komatsu, Masaaki; Yamaguchi-Iwai, Yuko; Ishikawa, Fuyuki; Mizushima, Noboru; Iwai, Kazuhiro

    2011-01-01

    Ferritin is a cytosolic protein that stores excess iron, thereby protecting cells from iron toxicity. Ferritin-stored iron is believed to be utilized when cells become iron deficient; however, the mechanisms underlying the extraction of iron from ferritin have yet to be fully elucidated. Here, we demonstrate that ferritin is degraded in the lysosome under iron-depleted conditions and that the acidic environment of the lysosome is crucial for iron extraction from ferritin and utilization by ce...

  11. Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury

    OpenAIRE

    Godar, Rebecca J.; Ma, Xiucui; Liu, Haiyan; Murphy, John T.; Carla J Weinheimer; Kovacs, Attila; Seth D Crosby; 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 fe...

  12. 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.

  13. Crystal structures of native and inhibited forms of human cathepsin D: implications for lysosomal targeting and drug design.

    OpenAIRE

    Baldwin, E. T.; Bhat, T N; Gulnik, S; Hosur, M. V.; Sowder, R C; Cachau, R.E.; Collins, J.; A. M. Silva; Erickson, J. W.

    1993-01-01

    Cathepsin D (EC 3.4.23.5) is a lysosomal protease suspected to play important roles in protein catabolism, antigen processing, degenerative diseases, and breast cancer progression. Determination of the crystal structures of cathepsin D and a complex with pepstatin at 2.5 A resolution provides insights into inhibitor binding and lysosomal targeting for this two-chain, N-glycosylated aspartic protease. Comparison with the structures of a complex of pepstatin bound to rhizopuspepsin and with a h...

  14. Starch Binding Domain-containing Protein 1 Plays a Dominant Role in Glycogen Transport to Lysosomes in Liver.

    Science.gov (United States)

    Sun, Tao; Yi, Haiqing; Yang, Chunyu; Kishnani, Priya S; Sun, Baodong

    2016-08-01

    A small portion of cellular glycogen is transported to and degraded in lysosomes by acid α-glucosidase (GAA) in mammals, but it is unclear why and how glycogen is transported to the lysosomes. Stbd1 has recently been proposed to participate in glycogen trafficking to lysosomes. However, our previous study demonstrated that knockdown of Stbd1 in GAA knock-out mice did not alter lysosomal glycogen storage in skeletal muscles. To further determine whether Stbd1 participates in glycogen transport to lysosomes, we generated GAA/Stbd1 double knock-out mice. In fasted double knock-out mice, glycogen accumulation in skeletal and cardiac muscles was not affected, but glycogen content in liver was reduced by nearly 73% at 3 months of age and by 60% at 13 months as compared with GAA knock-out mice, indicating that the transport of glycogen to lysosomes was suppressed in liver by the loss of Stbd1. Exogenous expression of human Stbd1 in double knock-out mice restored the liver lysosomal glycogen content to the level of GAA knock-out mice, as did a mutant lacking the Atg8 family interacting motif (AIM) and another mutant that contains only the N-terminal 24 hydrophobic segment and the C-terminal starch binding domain (CBM20) interlinked by an HA tag. Our results demonstrate that Stbd1 plays a dominant role in glycogen transport to lysosomes in liver and that the N-terminal transmembrane region and the C-terminal CBM20 domain are critical for this function. PMID:27358407

  15. 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

    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.......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...

  16. Divertor bypass in the Alcator C-Mod tokamak

    Science.gov (United States)

    Pitcher, C. S.; LaBombard, B.; Danforth, R.; Pina, W.; Silveira, M.; Parkin, B.

    2001-01-01

    The Alcator C-Mod divertor bypass has for the first time allowed in situ variations to the mechanical baffle design in a tokamak. The design utilizes small coils which interact with the ambient magnetic field inside the vessel to provide the torque required to control small flaps of a Venetian blind geometry. Plasma physics experiments with the bypass have revealed the importance of the divertor baffling to maintain high divertor gas pressures. These experiments have also indicated that the divertor baffling has only a limited effect on the main chamber pressure in C-Mod.

  17. 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.

  18. Full turbine bypass system for nuclear power plant

    International Nuclear Information System (INIS)

    With the increase in the weight of electric power network, vigilant watch is kept on the toughness of nuclear power plants against disturbances on the side of the network. Basically speaking, it is desirable that reactors continue operation even in case the station is removed from the network due to an outside disturbance. In order to meet this requirement, the application of a full-load turbine bypass system for 1,100-MW-class nuclear power plants has been planned; the development of system components was advanced; the reliability of the full-load turbine bypass system was confirmed through simulation tests. The process of development is outlined here. (author)

  19. Surgical cartographic navigation system for endoscopic bypass grafting.

    Science.gov (United States)

    Voruganti, Arun; Mayoral, Rafael; Jacobs, Stephan; Grunert, Ronny; Moeckel, Hendrik; Korb, Werner

    2007-01-01

    Endoscopic bypass grafting with the da Vinci system is still challenging and needs high level of experience and skill of the surgeon. Therefore, it is necessary to support the surgeon with enhanced vision and augmented reality. The augmentation of the patient model into the view of the endoscope is a direct approach to enhance support. The results of a preclinical study are shown in this paper. The method applied is suitable for endoscopic bypass grafting and in general applicable to minimal invasive surgery. The system was designed as an open architecture to facilitate easy transfer of the methodology into other surgical domain applications. PMID:18002243

  20. 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...

  1. 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.

  2. 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

  3. 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. PMID:25849458

  4. 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.

  5. 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.

  6. A six-membered-ring incorporated Si-rhodamine for imaging of copper(ii) in lysosomes.

    Science.gov (United States)

    Wang, Baogang; Cui, Xiaoyan; Zhang, Zhiqiang; Chai, Xiaoyun; Ding, Hao; Wu, Qiuye; Guo, Zhongwu; Wang, Ting

    2016-07-12

    The regulation of copper homeostasis in lysosomes of living cells is closely related to various physiological and pathological processes. Thus, it is of urgent need to develop a fluorescent probe for selectively and sensitively monitoring the location and concentration of lysosomal Cu(2+). Herein, a six-membered ring, thiosemicarbazide, was incorporated into a Si-rhodamine (SiR) scaffold for the first time, affording a SiR-based fluorescent probe SiRB-Cu. Through the effective Cu(2+)-triggered ring-opening process, the probe exhibits fast NIR chromogenic and fluorogenic responses to Cu(2+) within 2 min as the result of formation of a highly fluorescent product SiR-NCS. Compared with a five-membered ring, the expanded ring retains great tolerance to H(+), ensuring the superior sensitivity with a detection limit as low as 7.7 nM and 200-fold enhancement of relative fluorescence in the presence of 1.0 equiv. of Cu(2+) in pH = 5.0 solution, the physiological pH of lysosome. Moreover, the thiosemicarbazide moiety acts not only as the chelating and reactive site, but also as an efficient lysosome-targeting group, leading to the proactive accumulation of the probe into lysosomes. Taking advantage of these distinct properties, SiRB-Cu provides a functional probe suitable for imaging exogenous and endogenous lysosomal Cu(2+) with high imaging contrast and fidelity. PMID:27314426

  7. 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

  8. 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

  9. 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

  10. 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,...

  11. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  12. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  13. 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...

  14. 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...

  15. 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…

  16. 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.

  17. A device for a noninvasive evaluation of coronary bypass grafts.

    Science.gov (United States)

    McInerney, J J; Lamser, D G; Herr, M D

    1994-01-01

    A new device is presented for evaluating the patency of coronary bypass grafts. Bypass grafts are located within the chest cavity using a Compton backscatter imaging (CBI) technique that creates frontal plane tomographic images. The tomographic image pixels are mapped into computer memory and displayed. A display pointer is used to mark the position of the bypass graft. The computer uses that information to subsequently position a radiation detector, such that it "looks" at the location of the bypass graft within the closed chest. The patency of the graft is then evaluated by monitoring an X-ray induced iodine fluorescence transient in the graft, subsequent to a peripheral intravenous contrast injection. This imaging and graft evaluation device is relatively inexpensive and its application does not require cutdowns or catheterization. The associated radiation dose is 1/10 to 1/50 of that associated with alternative X-ray graft patency evaluation techniques. Preliminary testing has been performed on mechanical and animal models. PMID:18218544

  18. Integral bypass diodes in an amorphous silicon alloy photovoltaic module

    Science.gov (United States)

    Hanak, J. J.; Flaisher, H.

    1991-01-01

    Thin-film, tandem-junction, amorphous silicon (a-Si) photovoltaic modules were constructed in which a part of the a-Si alloy cell material is used to form bypass protection diodes. This integral design circumvents the need for incorporating external, conventional diodes, thus simplifying the manufacturing process and reducing module weight.

  19. Simulation and Analysis of the bypass Influences on Tire Noise

    Directory of Open Access Journals (Sweden)

    Haichao Zhou

    2014-01-01

    Full Text Available It is a well-known scientific fact that circumferential groove exists great influence on tire noise. Increasing the void can help the rubber blocks to penetrate faster into the underlying water film and improve anti-skid performance, but which gives way to an increased air pumping noise. Therefore, the structure parameters of circumferential grooves play large influence on tire performance. The goal of this present study is using the bypass to change the grooves design and analysis the influence of bypass on tire noise and offer the tire designer a better approach to improve tire comfort ability. By virtual of numerical simulation method, the influence of bypass structure parameters, such as the width of junction pipe, the volume of resonance cavity, on tire noise were analyzed in this study. The result shows that the circumferential grooves with bypass not only bring down pipe resonance noise of circumferential grooves but also decrease far-field radiated noise of tire. Besides, with a certain resonant cavity, the width of junction pipeline between the circumferential grooves and the resonance cavity plays an important role in the improvement of tire noise. Simulation results are in reasonable agreement with experimental results.

  20. 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

  1. Advances in Weight Loss Surgery: The Fully Robotic Gastric Bypass

    Medline Plus

    Full Text Available ... that we see are those patients that have diabetes mellitus type II, and that’s diabetes associated with obesity. And there’s no question that ... The other question is, “Does gastric bypass eliminate diabetes and does the sleeve?” It’s not the type of -- it’s not actually the type of procedure ...

  2. 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...

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. Changes in Hematology and Calcium Metabolism After Gastric Bypass Surgery

    DEFF Research Database (Denmark)

    Worm, Dorte; Madsbad, Sten; Kristiansen, Viggo B;

    2015-01-01

    BACKGROUND: Concerns regarding nutritional deficiencies have recently emerged after Roux-en-Y gastric bypass (RYGB). METHODS: A total of 835 subjects underwent RYGB, age 43.3 years, body mass index (BMI) 47.2 kg/m(2). Hematological and calcium metabolic variables were measured before, 6, 12, and 24...

  8. 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...

  9. Robot-Assisted Minimally Invasive Coronary Artery Bypass Surgery Operation

    Medline Plus

    Full Text Available ... PINNACLEHEALTH HARRISBURG HOSPITAL HARRISBURG, PA 00:00:08 JOHN PENNOCK, MD: Welcome this evening to PinnacleHealth Harrisburg ... artery bypass surgery operation. My name is Dr. John Pennock. I'm going to introduce you shortly ...

  10. 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.

  11. 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.

  12. 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. PMID:27154979

  13. 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.

  14. 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. PMID:26103523

  15. 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.

  16. 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.

  17. Diagnostic and clinical relevance of the autophago-lysosomal network in human gliomas

    Science.gov (United States)

    Jennewein, Lukas; Ronellenfitsch, Michael W.; Antonietti, Patrick; Ilina, Elena I.; Jung, Jennifer; Stadel, Daniela; Flohr, Lisa-Marie; Zinke, Jenny; von Renesse, Janusz; Drott, Ulrich; Baumgarten, Peter; Braczynski, Anne K.; Penski, Cornelia; Burger, Michael C.; Theurillat, Jean-Philippe; Steinbach, Joachim P.; Plate, Karl-Heinz; Dikic, Ivan; Fulda, Simone; Brandts, Christian; Kögel, Donat; Behrends, Christian; Harter, Patrick N.; Mittelbronn, Michel

    2016-01-01

    Recently, the conserved intracellular digestion mechanism ‘autophagy’ has been considered to be involved in early tumorigenesis and its blockade proposed as an alternative treatment approach. However, there is an ongoing debate about whether blocking autophagy has positive or negative effects in tumor cells. Since there is only poor data about the clinico-pathological relevance of autophagy in gliomas in vivo, we first established a cell culture based platform for the in vivo detection of the autophago-lysosomal components. We then investigated key autophagosomal (LC3B, p62, BAG3, Beclin1) and lysosomal (CTSB, LAMP2) molecules in 350 gliomas using immunohistochemistry, immunofluorescence, immunoblotting and qPCR. Autophagy was induced pharmacologically or by altering oxygen and nutrient levels. Our results show that autophagy is enhanced in astrocytomas as compared to normal CNS tissue, but largely independent from the WHO grade and patient survival. A strong upregulation of LC3B, p62, LAMP2 and CTSB was detected in perinecrotic areas in glioblastomas suggesting micro-environmental changes as a driver of autophagy induction in gliomas. Furthermore, glucose restriction induced autophagy in a concentration-dependent manner while hypoxia or amino acid starvation had considerably lesser effects. Apoptosis and autophagy were separately induced in glioma cells both in vitro and in vivo. In conclusion, our findings indicate that autophagy in gliomas is rather driven by micro-environmental changes than by primary glioma-intrinsic features thus challenging the concept of exploitation of the autophago-lysosomal network (ALN) as a treatment approach in gliomas. PMID:26956048

  18. Three-layer poly(methyl methacrylate) microsystem for analysis of lysosomal enzymes for diagnostic purposes

    International Nuclear Information System (INIS)

    Highlights: • New approach for measuring the activity of lysosomal enzymes. • Determination of a protonated form of 4-MU directly in the enzymatic mixture. • Elimination of a long incubation step. • Significant reduction of the processing time and simplification of the procedure. - Abstract: Lysosomal storage diseases are chronic, progressive and typically have a devastating impact on the patient and the family. The diagnosis of these diseases is still a challenge, however, even for trained specialists. Accurate diagnostic methods and high-throughput tools that could be readily incorporated into existing screening laboratories are urgently required. We propose a new method for measuring the activity of lysosomal enzymes using a microfluidic device. The principle of the method is the fluorometric determination of a protonated form of 4-methylumbelliferone directly in the enzymatic mixture. Compared to the standard diagnostic protocols, the method eliminates the necessity to add alkaline buffer to stop the enzymatic reaction, and thus, the number of analytical steps is reduced. The system allows for on-chip short-term incubation of the enzymatic reagents, leading to a much simplified analytical procedure and a significantly shortened processing time. We measured the activity of β-galactosidase in RPMI-1788 human B lymphocytes and in isolated leukocytes from healthy adults. The method shows a good agreement with the standard diagnostic method. The agreement was confirmed by statistical analysis including construction of a Bland–Altman plot. The approach presented can be an alternative for the currently used diagnostic procedures. The method developed has a potential for the implementation into complex microfluidic devices thus becoming a powerful tool for a high-throughput and multiplex screening of newborns

  19. The Serotonin Transporter Undergoes Constitutive Internalization and Is Primarily Sorted to Late Endosomes and Lysosomal Degradation*

    Science.gov (United States)

    Rahbek-Clemmensen, Troels; Bay, Tina; Eriksen, Jacob; Gether, Ulrik; Jørgensen, Trine Nygaard

    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 the surface resident SERT, two functional epitope-tagged variants were generated. Fusion of a FLAG-tagged one-transmembrane segment protein Tac to the SERT N terminus generated a transporter with an extracellular epitope suited for trafficking studies (TacSERT). Likewise, a construct with an extracellular antibody epitope was generated by introducing an HA (hemagglutinin) tag in the extracellular loop 2 of SERT (HA-SERT). By using TacSERT and HA-SERT in antibody-based internalization assays, we show that SERT undergoes constitutive internalization in a dynamin-dependent manner. Confocal images of constitutively internalized SERT demonstrated that SERT primarily co-localized with the late endosomal/lysosomal marker Rab7, whereas little co-localization was observed with the Rab11, a marker of the “long loop” recycling pathway. This sorting pattern was distinct from that of a prototypical recycling membrane protein, the β2-adrenergic receptor. 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 analog JHC1-64 and by reversible and pulse-chase biotinylation assays showing evidence for lysosomal degradation of the internalized transporter. Finally, we found that SERT internalized in response to stimulation with 12-myristate 13-acetate co-localized primarily with Rab7- and LysoTracker-positive compartments. We conclude that SERT is constitutively internalized and that the internalized transporter is sorted mainly to degradation. PMID:24973209

  20. Three-layer poly(methyl methacrylate) microsystem for analysis of lysosomal enzymes for diagnostic purposes

    Energy Technology Data Exchange (ETDEWEB)

    Kwapiszewski, Radoslaw, E-mail: r.kwapiszewski@gmail.com [Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Kwapiszewska, Karina [Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Kutter, Jörg P. [Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen (Denmark); Brzozka, Zbigniew [Department of Microbioanalytics, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

    2015-01-01

    Highlights: • New approach for measuring the activity of lysosomal enzymes. • Determination of a protonated form of 4-MU directly in the enzymatic mixture. • Elimination of a long incubation step. • Significant reduction of the processing time and simplification of the procedure. - Abstract: Lysosomal storage diseases are chronic, progressive and typically have a devastating impact on the patient and the family. The diagnosis of these diseases is still a challenge, however, even for trained specialists. Accurate diagnostic methods and high-throughput tools that could be readily incorporated into existing screening laboratories are urgently required. We propose a new method for measuring the activity of lysosomal enzymes using a microfluidic device. The principle of the method is the fluorometric determination of a protonated form of 4-methylumbelliferone directly in the enzymatic mixture. Compared to the standard diagnostic protocols, the method eliminates the necessity to add alkaline buffer to stop the enzymatic reaction, and thus, the number of analytical steps is reduced. The system allows for on-chip short-term incubation of the enzymatic reagents, leading to a much simplified analytical procedure and a significantly shortened processing time. We measured the activity of β-galactosidase in RPMI-1788 human B lymphocytes and in isolated leukocytes from healthy adults. The method shows a good agreement with the standard diagnostic method. The agreement was confirmed by statistical analysis including construction of a Bland–Altman plot. The approach presented can be an alternative for the currently used diagnostic procedures. The method developed has a potential for the implementation into complex microfluidic devices thus becoming a powerful tool for a high-throughput and multiplex screening of newborns.

  1. Visualization of Endogenous and Exogenous Hydrogen Peroxide Using A Lysosome-Targetable Fluorescent Probe

    Science.gov (United States)

    Kim, Dabin; Kim, Gyoungmi; Nam, Sang-Jip; Yin, Jun; Yoon, Juyoung

    2015-02-01

    Reactive oxygen species (ROS) play crucial roles in diverse physiological processes; therefore, the efficient detection of ROS is very crucial. In this study, we report a boronate-based hydrogen peroxide (H2O2) probe having naphthalimide fluorophore. This probe also contained a morpholine moiety as a directing group for lysosome. The recognition property indicated that the probe exhibited high selectivity towards H2O2 not only in the solution but also in the living cells. Furthermore, it was used to monitor the level of endogenous and exogenous H2O2. These results support that the probe can function as an efficient indicator to detect H2O2.

  2. Phorbol myristate acetate stimulates phagosome-lysosome fusion in mouse macrophages

    OpenAIRE

    1981-01-01

    The effect of the tumor promoter phorbol myristate acetate (PMA) on phagosome-lysosome (P-L) fusion in mouse macrophages has been studied using a previously described (10) fluorescence assay. Treatment with 0.1--1.0 microgram PMA/ml caused a striking increase in the rate and extent of P-L fusion. Exposure of cells to phorbol, free myristate, or the monoesters of PMA did not reproduce this effect. Macrophages required from 2 to 3 h of pretreatment to express maximal P-L fusion, and this was ma...

  3. 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.

  4. EGFRvIII escapes down-regulation due to impaired internalization and sorting to lysosomes

    DEFF Research Database (Denmark)

    Grandal, Michael V; Zandi, Roza; Pedersen, Mikkel W;

    2007-01-01

    signaling pathways. Failure to attenuate signaling by receptor down-regulation could be one of the major mechanisms by which EGFRvIII becomes oncogenic. Using a cell system expressing either EGFR or EGFRvIII with no expression of other EGFR family members and with endogenous levels of key degradation....... Moreover, internalized EGFRvIII is recycled rather than delivered to lysosomes. EGFRvIII binds the ubiquitin ligase c-Cbl via Grb2, whereas binding via phosphorylated tyrosine residue 1045 seems to be limited. Despite c-Cbl binding, the receptor fails to become effectively ubiquitinylated. Thus, our...

  5. 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.

  6. Adaptor protein complexes AP-1 and AP-3 are required by the HHV-7 Immunoevasin U21 for rerouting of class I MHC molecules to the lysosomal compartment.

    Directory of Open Access Journals (Sweden)

    Lisa A Kimpler

    Full Text Available The human herpesvirus-7 (HHV-7 U21 gene product binds to class I major histocompatibility complex (MHC molecules and reroutes them to a lysosomal compartment. Trafficking of integral membrane proteins to lysosomes is mediated through cytoplasmic sorting signals that recruit heterotetrameric clathrin adaptor protein (AP complexes, which in turn mediate protein sorting in post-Golgi vesicular transport. Since U21 can mediate rerouting of class I molecules to lysosomes even when lacking its cytoplasmic tail, we hypothesize the existence of a cellular protein that contains the lysosomal sorting information required to escort class I molecules to the lysosomal compartment. If such a protein exists, we expect that it might recruit clathrin adaptor protein complexes as a means of lysosomal sorting. Here we describe experiments demonstrating that the μ adaptins from AP-1 and AP-3 are involved in U21-mediated trafficking of class I molecules to lysosomes. These experiments support the idea that a cellular protein(s is necessary for U21-mediated lysosomal sorting of class I molecules. We also examine the impact of transient versus chronic knockdown of these adaptor protein complexes, and show that the few remaining μ subunits in the cells are eventually able to reroute class I molecules to lysosomes.

  7. Loss of Niemann-Pick C1 or C2 protein results in similar biochemical changes suggesting that these proteins function in a common lysosomal pathway.

    Directory of Open Access Journals (Sweden)

    Sayali S Dixit

    Full Text Available Niemann-Pick Type C (NPC disease is a lysosomal storage disorder characterized by accumulation of unesterified cholesterol and other lipids in the endolysosomal system. NPC disease results from a defect in either of two distinct cholesterol-binding proteins: a transmembrane protein, NPC1, and a small soluble protein, NPC2. NPC1 and NPC2 are thought to function closely in the export of lysosomal cholesterol with both proteins binding cholesterol in vitro but they may have unrelated lysosomal roles. To investigate this possibility, we compared biochemical consequences of the loss of either protein. Analyses of lysosome-enriched subcellular fractions from brain and liver revealed similar decreases in buoyant densities of lysosomes from NPC1 or NPC2 deficient mice compared to controls. The subcellular distribution of both proteins was similar and paralleled a lysosomal marker. In liver, absence of either NPC1 or NPC2 resulted in similar alterations in the carbohydrate processing of the lysosomal protease, tripeptidyl peptidase I. These results highlight biochemical alterations in the lysosomal system of the NPC-mutant mice that appear secondary to lipid storage. In addition, the similarity in biochemical phenotypes resulting from either NPC1 or NPC2 deficiency supports models in which the function of these two proteins within lysosomes are linked closely.

  8. 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.

  9. Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

    International Nuclear Information System (INIS)

    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

  10. 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

  11. Bilateral Internal Thoracic Artery Configuration for Coronary Artery Bypass Surgery

    Science.gov (United States)

    Boodhwani, Munir; Hanet, Claude; de Kerchove, Laurent; Navarra, Emiliano; Astarci, Parla; Noirhomme, Philippe; El Khoury, Gebrine

    2016-01-01

    Background— Bilateral internal thoracic arteries (BITA) have demonstrated superior patency and improved survival in patients undergoing coronary artery bypass grafting. However, the optimal configuration for BITA utilization and its effect on long-term outcome remains uncertain. Methods and Results— We randomly assigned 304 patients undergoing coronary artery bypass grafting using BITA to either in situ or Y grafting configurations. The primary end point was 3-year angiographic patency. Secondary end points included major adverse cardiac and cerebrovascular events (ie, death from any cause, stroke, myocardial infarction, or repeat revascularization) at 7 years. More coronary targets were able to be revascularized using internal thoracic arteries in patients randomized to Y grafting versus in situ group (3.2±0.8 versus 2.4±0.5 arteries/patient; PURL: http://www.clinicaltrials.gov. Unique identifier: NCT01666366. PMID:27406988

  12. Ultra High Bypass Ratio Low Noise Engine Study

    Science.gov (United States)

    Dalton, W. N., III

    2003-01-01

    A study was conducted to identify engine cycle and technologies needed for a regional aircraft which could be capable of achieving a 10 EPNdB reduction in community noise level relative to current FAR36 Stage 3 limits. The study was directed toward 100-passenger regional aircraft with engine configurations in the 15,000 pound thrust class. The study focused on Ultra High Bypass Ratio (UHBR) cycles due to low exhaust jet velocities and reduced fan tip speeds. The baseline engine for this study employed a gear-driven, 1000 ft/sec tip speed fan and had a cruise bypass ratio of 14:1. A revised engine configuration employing fan and turbine design improvements are predicted to be 9.2 dB below current takeoff limits and 12.8 dB below current approach limits. An economic analysis was also done by estimating Direct Operating Cost (DOC).

  13. 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.

  14. Glycemic control and outcome related to cardiopulmonary bypass.

    Science.gov (United States)

    Thiessen, Steven; Vanhorebeek, Ilse; Van den Berghe, Greet

    2015-06-01

    Perioperative hyperglycemia, aggravated by cardiopulmonary bypass, is associated with adverse outcome in adult and pediatric patients. Whereas hyperglycemia was originally perceived as an adaptive response to surgical stress, it is now clear that glycemic control is a strategy to reduce adverse outcomes after cardiac surgery and cardiopulmonary bypass. The optimal blood glucose target, whether or not glycemic control should be initiated already intraoperatively, and whether or not perioperative glucose administration affects the impact of glycemic control on ischemia-reperfusion damage remain open questions. Hypoglycemia, the risk of which is increased with glycemic control, is also associated with adverse outcomes. However, it remains controversial whether brief episodes of hypoglycemia, rapidly corrected during glycemic control, have adverse effects on outcome. This review gives an overview of the currently available literature on glycemic control during and after cardiac surgery and focuses on the indicated open questions about this intervention for this specific patient population. PMID:26060029

  15. Psoriasis remission after gastric bypass surgery: a case report

    Directory of Open Access Journals (Sweden)

    Ornella De Pità

    2014-03-01

    Full Text Available Case reports suggest that gastric bypass surgery in patients with psoriasis may result in complete remission of the disease. A substantial weight loss is achieved in the months following surgery, which is likely to reduce psoriasis symptoms and risk of comorbidities. A 50-year-old man was followed in our Department for several years. He had severe plaque psoriasis requiring superpotent topical steroids and methotrexate. His medical history included morbid obesity (138 kg, dyslipidemia , hypertension and positive family history for psoriasis. He underwent gastric bypass surgery on November 2011. Eight months later, his weight decreased to 86 kg, and he noted a marked improvement in his psoriasis, with reduction of body surface area involvement. In our opinion weight loss may be a useful adjunctive therapy for obese patients with psoriasis.http://dx.doi.org/10.7175/cmi.v8i1.898  

  16. Outflow distribution at the distal anastomosis of infrainguinal bypass grafts.

    Science.gov (United States)

    Fisher, R K; How, T V; Bakran, A; Brennan, J A; Harris, P L

    2004-03-01

    Outflow distribution at the distal anastomosis of infrainguinal bypass grafts remains unquantified in vivo, but is likely to influence flow patterns and haemodynamics, thereby impacting upon graft patency. This study measured the ratio of distal to proximal outflow in 30 patients undergoing infrainguinal bypass for lower limb ischaemia, using a flow probe and a transit-time ultrasonic flow meter. The mean outflow distribution was approximately 75% distal to 25% proximal, with above knee anastomoses having a greater proportion of distal flow (84%) compared to below knee grafts (73%). These in vivo flow characteristics differ significantly from those used in theoretical models studying flow phenomena (50:50 and/or 100:0), and should be incorporated into future research. PMID:14757463

  17. 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.

  18. Glucocerebrosidase deficiency and lysosomal storage of glucocerebroside induced in cultured macrophages

    International Nuclear Information System (INIS)

    A cell culture model simulating the genetic deficiency of glucocerebrosidase has been developed, utilizing macrophages and conduritol B epoxide (CBE), the specific irreversible inhibitor of the enzyme. Rat peritoneal macrophage glucocerebrosidase was completely inhibited when cells were treated with 10 +M CBE for 16 h or 100 μM CBE for 2 h. The t/sub 1/2/ of inactivation was 30 min at 10+M concentration. When cells were washed free of CBE, the enzyme activity reappeared linearly with time, reaching 50% of control activity 48 h after removal of the inhibitor. CBE-treated macrophages have normal phagocytic activity toward [3H]glycine-coupled latex beads and a normal number of mannose receptors. CBE was found to have no effect on other lysosomal enzymes. When [14C]glucocerebroside, encapsulated in multilamellar liposomes with α-D-mannopyranoside covalently coupled to the surface, was fed to glucocerebrosidase-depleted macrophages, the radiolabelled glycolipid accumulated and was undegraded. Subcellular fractionation on a Percol density gradient demonstrated that the stored glucocerebroside in the CBE-treated macrophages was localized in lysosomes

  19. Microglial migration mediated by ATP-induced ATP release from lysosomes

    Institute of Scientific and Technical Information of China (English)

    Ying Dou; Qing-ming Luo; Shumin Duan; Hang-jun Wu; Hui-quan Li; Song Qin; Yin-er Wang; Jing Li; Hui-fang Lou; Zhong Chen; Xiao-ming Li

    2012-01-01

    Microglia are highly motile cells that act as the main form of active immune defense in the central nervous system.Attracted by factors released from damaged cells,microglia are recruited towards the damaged or infected site,where they are involved in degenerative and regenerative responses and phagocytotic clearance of cell debris.ATP release from damaged neural tissues has been suggested to mediate the rapid extension of microglial process towards the site of injury.However,the mechanisms of the long-range migration of microglia remain to be clarified.Here,we found that lysosomes in microglia contain abundant ATP and exhibit Ca2+-dependent exocytosis in response to various stimuli.By establishing an efficient in vitro chemotaxis assay,we demonstrated that endogenously-released ATP from microglia triggered by local microinjection of ATPγS is critical for the long-range chemotaxis of microglia,a response that was significantly inhibited in microglia treated with an agent inducing iysosome osmodialysis or in cells derived from mice deficient in Rab 27a (ashen mice),a small GTPase required for the trafficking and exocytosis of secretory iysosomes.These results suggest that microglia respond to extracellular ATP by releasing ATP themselves through lysosomal exocytosis,thereby providing a positive feedback mechanism to generate a long-range extracellular signal for attracting distant microglia to migrate towards and accumulate at the site of injury.

  20. Influence of cucumariosides upon intracellular [Ca2+]i and lysosomal activity of macrophages.

    Science.gov (United States)

    Agafonova, Irina G; Aminin, Dmitry L; Avilov, Sergey A; Stonik, Valentin A

    2003-11-19

    Biological effects of the triterpene glycosides, cucumariosides A(2)-2 and A(7)-1 from the edible sea cucumber Cucumaria japonica and their aglycones were investigated using embryos of the sea urchin Strongylocentrotus nudus and the BALB/C line mouse peritoneal macrophages. Cucumariosides were highly cytotoxic in a sea urchin embryo development test with EC(50) values of 0.3 and 1.98 microg/mL, respectively. The aglycone was completely lacking in cytotoxicity. In subtoxic concentrations (0.001-0.1 microg/mL), cucumarioside A(2)-2 showed more then 2-fold stimulation of lysosomal activity and induced a rapid short-term increase in cytosolic Ca(2+) content in mouse macrophages. The maximal stimulatory effect was detected after 1-2 h of cultivation of cells with this glycoside. Cucumarioside A(7)-1 demonstrated more weak effects and even slightly inhibited lysosomal activity, while the aglycone was completely ineffective. At the toxic concentration (1 microg/mL), cucumarioside A(2)-2 induced the sharp irreversable increase of intracellular Ca(2+) concentration. We suggested that cucumariosides, especially A(2)-2, may act as Ca(2+) agonists due to their membranolytic properties. PMID:14611158

  1. Disease models for the development of therapies for lysosomal storage diseases.

    Science.gov (United States)

    Xu, Miao; Motabar, Omid; Ferrer, Marc; Marugan, Juan J; Zheng, Wei; Ottinger, Elizabeth A

    2016-05-01

    Lysosomal storage diseases (LSDs) are a group of rare diseases in which the function of the lysosome is disrupted by the accumulation of macromolecules. The complexity underlying the pathogenesis of LSDs and the small, often pediatric, population of patients make the development of therapies for these diseases challenging. Current treatments are only available for a small subset of LSDs and have not been effective at treating neurological symptoms. Disease-relevant cellular and animal models with high clinical predictability are critical for the discovery and development of new treatments for LSDs. In this paper, we review how LSD patient primary cells and induced pluripotent stem cell-derived cellular models are providing novel assay systems in which phenotypes are more similar to those of the human LSD physiology. Furthermore, larger animal disease models are providing additional tools for evaluation of the efficacy of drug candidates. Early predictors of efficacy and better understanding of disease biology can significantly affect the translational process by focusing efforts on those therapies with the higher probability of success, thus decreasing overall time and cost spent in clinical development and increasing the overall positive outcomes in clinical trials. PMID:27144735

  2. 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.

  3. Lyso-glycosphingolipid abnormalities in different murine models of lysosomal storage disorders.

    Science.gov (United States)

    Ferraz, Maria J; Marques, André R A; Gaspar, Paulo; Mirzaian, Mina; van Roomen, Cindy; Ottenhoff, Roelof; Alfonso, Pilar; Irún, Pilar; Giraldo, Pilar; Wisse, Patrick; Sá Miranda, Clara; Overkleeft, Herman S; Aerts, Johannes M

    2016-02-01

    In lysosomal glycosphingolipid storage disorders, marked elevations in corresponding glycosphingoid bases (lyso-glycosphingolipids) have been reported, such as galactosylsphingosine in Krabbe disease, glucosylsphingosine in Gaucher disease and globotriaosylsphingosine in Fabry disease. Using LC–MS/MS, we comparatively investigated the occurrence of abnormal lyso-glycosphingolipids in tissues and plasma of mice with deficiencies in lysosomal α-galactosidase A, glucocerebrosidase and galactocerebrosidase. The nature and specificity of lyso-glycosphingolipid abnormalities are reported and compared to that in correspondingly more abundant N-acylated glycosphingolipids. Specific elevations in tissue and plasma globotriaosylsphingosine were detected in α-galactosidase A-deficient mice; glucosylsphingosine in glucocerebrosidase-deficient mice and galactosylsphingosine in galactocerebrosidase-deficient animals. A similar investigation was conducted for two mouse models of Niemann Pick type C (Npc1nih and Npc1nmf164), revealing significant tissue elevation of several neutral glycosphingolipids and concomitant increased plasma glucosylsphingosine. This latter finding was recapitulated by analysis of plasma of NPC patients. The value of plasma glucosylsphingosine in biochemical confirmation of the diagnosis of NPC is discussed. PMID:26750750

  4. Demographic characteristics and distribution of lysosomal storage disorder subtypes in Eastern China.

    Science.gov (United States)

    Chen, Xueru; Qiu, Wenjuan; Ye, Jun; Han, Lianshu; Gu, Xuefan; Zhang, Huiwen

    2016-04-01

    Lysosomal storage disorders (LSDs) are a group of >50 different types of inherited metabolic disorders that result from defects in the lysosome. The aim of this study was to investigate the distribution and demographic characteristics of the different subtypes of LSDs in Eastern China. From 2006 to 2012, 376 out of 1331 clinically suspected patients were diagnosed with 17 different subtypes of LSDs at our hospital. Mucopolysaccharidoses (MPS) were the most common group of LSDs (50.5%), followed by sphingolipidoses (25.4%) and Pompe disease (19.8%). Mucolipidosis type II/III accounted for the remaining 4% of diagnosed LSDs. MPS II was the most common form of MPS, comprising 47.4% of all MPS cases diagnosed, followed by MPS IVA (26.8%) and MPS I (16.3%). Gaucher disease and Niemann-Pick disease type A/B were the two most common forms of sphingolipidoses. There was a large variation in the time between disease onset and eventual diagnosis, from 0.3 years in infantile-onset Pompe disease to 30 years in Fabry disease, highlighting timely and accurate diagnosis of LSDs as the main challenge in China. PMID:26740238

  5. [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.

  6. 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.

  7. 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.

  8. 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.

  9. Efficacy of Intravenous Acetaminophen after Coronary Artery Bypass Graft Surgery

    OpenAIRE

    Leick AM; Ratliff PD; Shely RN; Lester WC; Short MR

    2015-01-01

    In recent years, a multimodal approach to post-operative pain control consisting of opioid and non-opioid agents administered simultaneously has been used to provide synergistic effects and reduce opioid-related adverse effects. This is a retrospective, cohort study involving coronary artery bypass graft surgery patients who received scheduled intravenous IV acetaminophen 1gm every 6 hours for 4 doses starting at surgery end time with opioids administered as needed versus opioids as monother...

  10. Access pricing, bypass and universal service in post

    OpenAIRE

    Armstrong, Mark

    2006-01-01

    A postal regulator typically faces two issues which make the design of efficient access pricing especially difficult and which complicate the process of liberalizing the industry. First, universal service obligations, together with the presence of fixed costs, require retail prices to depart from the underlying marginal costs of the incumbent provider. Second, competing firms may be able to bypass the incumbent’s delivery network. Within a simple and stylized framework, this note ...

  11. Effects of Deep Breathing Exercises after Coronary Artery Bypass Surgery

    OpenAIRE

    Westerdahl, Elisabeth

    2004-01-01

    Deep breathing exercises are widely used in the postoperative care to prevent or reduce pulmonary complications, but no scientific evidence for the efficacy has been found after coronary artery bypass grafting (CABG) surgery. The aim of the thesis was to describe postoperative pulmonary function and to evaluate the efficacy of deep breathing exercises performed with or without a blow bottle device for positive expiratory pressure (PEP) 10 cmH2O or an inspiratory resistance-positive expirator...

  12. Early chest tube removal after coronary artery bypass graft surgery

    Directory of Open Access Journals (Sweden)

    Mohsen Mirmohammad-Sadeghi

    2009-01-01

    Full Text Available Background: There is no clear data about the optimum time for chest tube removal after coronary artery bypass surgery. Aim: The aim of this study was to assess the impact of the chest tube removal time following coronary artery bypass grafting surgery on the clinical outcome of the patients. Material and Methods: An analysis of data from 307 patients was performed. The patients were randomized into two groups: in group 1 (N=107 chest tubes were removed within the first 24 hours after surgery, whereas in group 2 (N=200, chest tubes were removed in the second 24 hours after surgery. Demographics, lactate and pH at the beginning, during and after the operation, creatinine, left ventricular ejection fraction, inotropic drugs administration, length of ICU stay, and mortality data were collected. Respiratory rate and pain level was assessed. Results: In these surgeries, the mean± standard deviation for the aortic clamping time was 49.18±17.59 minutes and cardiopulmonary bypass time was 78.39±25.12 minutes. The amount of heparin consumed by the second group was higher (P <0.001 which could be considered as an important factor in increasing the drainage time after the surgery (P =0.047. The pain level evaluated 24 hours post-operation was lower in the first group, and the difference in the pain level between the 2 groups evaluated 30 hours post-operation was significant (P=0.016. The mean time of intensive care unit stay was longer in the second group but it was not statistically significant. Conclusion: Early extracting of chest tubes after coronary artery bypass graft surgery when there is no significant drainage can lead to pain reduction and consuming oxygen is an effective measure after surgery toward healing; it doesn′t increase the risk of creation of plural effusion and pericardial effusion.

  13. An Efficient Bypassing Void Routing Algorithm for Wireless Sensor Network

    OpenAIRE

    2015-01-01

    Since the sensor node’s distribution in a wireless sensor network (WSN) is irregular, geographic routing protocols using the greedy algorithm can cause local minima problem. This problem may fail due to routing voids and lead to failure of data transmission. Based on the virtual coordinate mapping, this paper proposes an efficient bypassing void routing protocol to solve the control packet overhead and transmission delay in routing void of WSN, which is called EBVRPVCM. The basic idea is to t...

  14. CULTURAL DIAGNOSIS AND BYPASSING; THE EFFECT ON SUCCESSFUL INTERNATIONALIZATION

    OpenAIRE

    Andrews Adugudaa Akolaa

    2012-01-01

    Globalization and its effect on business continue to propel firms to look beyond local markets for opportunities for market development and as a source of growth. However, Cultural differences in various markets continue to exert enormous pressure on international market operations as a result of cultural bypassing or misdiagnosis and this requires international marketers to undertake robust cultural analysis to ensure successful market servicing strategies. This paper reviews and discusses t...

  15. 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

    showed impaired capacity for acidification of urine. The lowest urinary pH was 5.53 +/- 0.10 in 10 bypass patients and 4.76 +/- 0.06 in 6 controls. The corresponding values for standard bicarbonate in plasma were 15.0 +/- 0.3 mM and 15.8 +/- 0.3 mM. Glomerular filtration rate was identical in the two...

  16. Simulation and Analysis of the bypass Influences on Tire Noise

    OpenAIRE

    Haichao Zhou; Guolin Wang; Jian Yang; Shizhou Ying

    2014-01-01

    It is a well-known scientific fact that circumferential groove exists great influence on tire noise. Increasing the void can help the rubber blocks to penetrate faster into the underlying water film and improve anti-skid performance, but which gives way to an increased air pumping noise. Therefore, the structure parameters of circumferential grooves play large influence on tire performance. The goal of this present study is using the bypass to change the grooves design and analysis the influe...

  17. Successful cardiopulmonary bypass in diabetics with anaphylactoid reactions to protamine.

    OpenAIRE

    Walker, W. S.; Reid, K G; Hider, C F; Davidson, I. A.; Boulton, F. E.; Yap, P L

    1984-01-01

    Two insulin dependent diabetics with previous anaphylactic like (anaphylactoid) reactions to protamine underwent successful cardiopulmonary bypass for coronary artery surgery. Platelet concentrates instead of protamine were used to neutralise their systemic heparinisation. In both cases the anaphylactoid reactions first became apparent after administration of protamine sulphate at the end of cardiac catheterisation. These cases show that adverse reactions to protamine need not be a contraindi...

  18. Laboratory research: bed load guidance into sediment bypass tunnel inlet

    OpenAIRE

    De Cesare, Giovanni; Manso, Pedro; Daneshvari, M.; Schleiss, Anton

    2015-01-01

    Sediment management in reservoirs situated in mountainous regions is a critical operational concern with direct implications in live storage sustainability and therefore in production revenues. The paper presents the main results of a physical model study of a sediment evacuation system foreseen for a large hydropower scheme in Ecuador, carried out at the Laboratory of Hydraulic Constructions (LCH) of the Ecole Polytechnique Fédérale de Lausanne (EPFL). The system comprises a sediment bypass ...

  19. 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.

  20. Pathogenic LRRK2 mutations, through increased kinase activity, produce enlarged lysosomes with reduced degradative capacity and increase ATP13A2 expression.

    Science.gov (United States)

    Henry, Anastasia G; Aghamohammadzadeh, Soheil; Samaroo, Harry; Chen, Yi; Mou, Kewa; Needle, Elie; Hirst, Warren D

    2015-11-01

    Lysosomal dysfunction plays a central role in the pathogenesis of several neurodegenerative disorders, including Parkinson's disease (PD). Several genes linked to genetic forms of PD, including leucine-rich repeat kinase 2 (LRRK2), functionally converge on the lysosomal system. While mutations in LRRK2 are commonly associated with autosomal-dominant PD, the physiological and pathological functions of this kinase remain poorly understood. Here, we demonstrate that LRRK2 regulates lysosome size, number and function in astrocytes, which endogenously express high levels of LRRK2. Expression of LRRK2 G2019S, the most common pathological mutation, produces enlarged lysosomes and diminishes the lysosomal capacity of these cells. Enlarged lysosomes appears to be a common phenotype associated with pathogenic LRRK2 mutations, as we also observed this effect in cells expressing other LRRK2 mutations; R1441C or Y1699C. The lysosomal defects associated with these mutations are dependent on both the catalytic activity of the kinase and autophosphorylation of LRRK2 at serine 1292. Further, we demonstrate that blocking LRRK2's kinase activity, with the potent and selective inhibitor PF-06447475, rescues the observed defects in lysosomal morphology and function. The present study also establishes that G2019S mutation leads to a reduction in lysosomal pH and increased expression of the lysosomal ATPase ATP13A2, a gene linked to a parkinsonian syndrome (Kufor-Rakeb syndrome), in brain samples from mouse and human LRRK2 G2019S carriers. Together, these results demonstrate that PD-associated LRRK2 mutations perturb lysosome function in a kinase-dependent manner, highlighting the therapeutic promise of LRRK2 kinase inhibitors in the treatment of PD. PMID:26251043