WorldWideScience

Sample records for cd1c bypasses lysosomes

  1. Lysosome

    Directory of Open Access Journals (Sweden)

    Ursula Matte BSc, PhD

    2016-12-01

    Full Text Available Since Christian de Duve first described the lysosome in the 1950s, it has been generally presented as a membrane-bound compartment containing acid hydrolases that enables the cell to degrade molecules without being digested by autolysis. For those working on the field of lysosomal storage disorders, the lack of one such hydrolase would lead to undegraded or partially degraded substrate storage inside engorged organelles disturbing cellular function by yet poorly explored mechanisms. However, in recent years, a much more complex scenario of lysosomal function has emerged, beyond and above the cellular “digestive” system. Knowledge on how the impairment of this organelle affects cell functioning may shed light on signs and symptoms of lysosomal disorders and open new roads for therapy.

  2. CD1c tetramers detect ex vivo T cell responses to processed phosphomycoketide antigens

    NARCIS (Netherlands)

    Ly, Dalam; Kasmar, Anne G.; Cheng, Tan-Yun; de Jong, Annemieke; Huang, Shouxiong; Roy, Sobhan; Bhatt, Apoorva; van Summeren, Ruben P.; Altman, John D.; Jacobs, William R.; Adams, Erin J.; Minnaard, Adriaan J.; Porcelli, Steven A.; Moody, Branch; Jacobs Jr., William R.

    2013-01-01

    CD1c is expressed with high density on human dendritic cells (DCs) and B cells, yet its antigen presentation functions are the least well understood among CD1 family members. Using a CD1c-reactive T cell line (DN6) to complete an organism-wide survey of M. tuberculosis lipids, we identified C32

  3. The 2.5 Å Structure of CD1c in Complex with a Mycobacterial Lipid Reveals an Open Groove Ideally Suited for Diverse Antigen Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Scharf, Louise; Li, Nan-Sheng; Hawk, Andrew J.; Garzón, Diana; Zhang, Tejia; Fox, Lisa M.; Kazen, Allison R.; Shah, Sneha; Haddadian, Esmael J.; Gumperz, Jenny E.; Saghatelian, Alan; Faraldo-Gómez, José D.; Meredith, Stephen C.; Piccirilli, Joseph A.; Adams, Erin J. (Harvard); (UC); (MXPL-G); (UW-MED)

    2011-08-24

    CD1 molecules function to present lipid-based antigens to T cells. Here we present the crystal structure of CD1c at 2.5 {angstrom} resolution, in complex with the pathogenic Mycobacterium tuberculosis antigen mannosyl-{beta}1-phosphomycoketide (MPM). CD1c accommodated MPM's methylated alkyl chain exclusively in the A pocket, aided by a unique exit portal underneath the {alpha}1 helix. Most striking was an open F pocket architecture lacking the closed cavity structure of other CD1 molecules, reminiscent of peptide binding grooves of classical major histocompatibility complex molecules. This feature, combined with tryptophan-fluorescence quenching during loading of a dodecameric lipopeptide antigen, provides a compelling model by which both the lipid and peptide moieties of the lipopeptide are involved in CD1c presentation of lipopeptides.

  4. Human Blood CD1c+ Dendritic Cells Promote Th1 and Th17 Effector Function in Memory CD4+ T Cells.

    Science.gov (United States)

    Leal Rojas, Ingrid M; Mok, Wai-Hong; Pearson, Frances E; Minoda, Yoshihito; Kenna, Tony J; Barnard, Ross T; Radford, Kristen J

    2017-01-01

    Dendritic cells (DC) initiate the differentiation of CD4 + helper T cells into effector cells including Th1 and Th17 responses that play an important role in inflammation and autoimmune disease pathogenesis. In mice, Th1 and Th17 responses are regulated by different conventional (c) DC subsets, with cDC1 being the main producers of IL-12p70 and inducers of Th1 responses, while cDC2 produce IL-23 to promote Th17 responses. The role that human DC subsets play in memory CD4 + T cell activation is not known. This study investigated production of Th1 promoting cytokine IL-12p70, and Th17 promoting cytokines, IL-1β, IL-6, and IL-23, by human blood monocytes, CD1c + DC, CD141 + DC, and plasmacytoid DC and examined their ability to induce Th1 and Th17 responses in memory CD4 + T cells. Human CD1c + DC produced IL-12p70, IL-1β, IL-6, and IL-23 in response to R848 combined with LPS or poly I:C. CD141 + DC were also capable of producing IL-12p70 and IL-23 but were not as proficient as CD1c + DC. Activated CD1c + DC were endowed with the capacity to promote both Th1 and Th17 effector function in memory CD4 + T cells, characterized by high production of interferon-γ, IL-17A, IL-17F, IL-21, and IL-22. These findings support a role for CD1c + DC in autoimmune inflammation where Th1/Th17 responses play an important role in disease pathogenesis.

  5. Human CD141+ Dendritic Cell and CD1c+ Dendritic Cell Undergo Concordant Early Genetic Programming after Activation in Humanized Mice In Vivo

    Directory of Open Access Journals (Sweden)

    Yoshihito Minoda

    2017-10-01

    Full Text Available Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ hematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity, and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. Conventional dendritic cells (cDCs in mice are categorized into cDC1, which mediate T helper (Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The likely human equivalents are CD141+ DC and CD1c+ DC subsets for mouse cDC1 and cDC2, respectively, but the extent of any interspecies differences is poorly characterized. Here, we exploit the fact that human CD141+ DC and CD1c+ DC develop in humanized mice, to further explore their equivalency in vivo. Global transcriptome analysis of CD141+ DC and CD1c+ DC isolated from humanized mice demonstrated that they closely resemble those in human blood. Activation of DC subsets in vivo, with the TLR3 ligand poly I:C, and the TLR7/8 ligand R848 revealed that a core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, while poly I:C upregulated IFN-λ genes specifically by CD141+ DC. MYCL expression, known to be essential for CD8+ T cell priming by mouse DC, was specifically induced in CD141+ DC after activation. Concomitantly, CD141+ DC were superior to CD1c+ DC in their ability to prime naïve antigen-specific CD8+ T cells. Thus, CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses, respectively. In combination, these data demonstrate that humanized mice provide an attractive and tractable model to study

  6. A pilot study of peripheral blood BDCA-1 (CD1c) positive dendritic cells pulsed with NY-ESO-1 ISCOMATRIX™ adjuvant.

    Science.gov (United States)

    Davis, Ian D; Quirk, Juliet; Morris, Leone; Seddon, Lauren; Tai, Tsin Yee; Whitty, Genevieve; Cavicchiolo, Tina; Ebert, Lisa; Jackson, Heather; Browning, Judy; MacGregor, Duncan; Wittke, Frederick; Winkels, Gregor; Alex, Regina; Miloradovic, Lena; Maraskovsky, Eugene; Chen, Weisan; Cebon, Jonathan

    2017-03-01

    Pilot clinical trial of NY-ESO-1 (ESO) protein in ISCOMATRIX™ adjuvant pulsed onto peripheral blood dendritic cells (PBDC), to ascertain feasibility, evaluate toxicity and assess induction of ESO-specific immune responses. Eligible participants had resected cancers expressing ESO or LAGE-1 and were at high risk of relapse. PBDC were produced using CliniMACS ® plus, with initial depletion of CD1c + B cells followed by positive selection of CD1c + PBDC. Patients received three intradermal vaccinations of ESO/IMX-pulsed PBDC at 4-week intervals. The process was feasible and safe. No vaccine-induced immune responses were detected. Assays of immunomodulatory cells did not correlate with outcomes. One patient had a long lasting complete remission. This method was feasible and safe but was minimally immunogenic.

  7. Lysosomes, Lysosomal Storage Diseases, and Inflammation

    Directory of Open Access Journals (Sweden)

    Calogera M. Simonaro PhD

    2016-05-01

    Full Text Available Lysosomes were originally described in the early 1950s by de Duve who was also the first to recognize the importance of these organelles in human disease. We know now that lysosomes are involved in numerous biological processes, and abnormalities in lysosomal function may result in a broad range of diseases. This review will briefly discuss the role of lysosomes in inflammation and how disruption of normal lysosomal function in the lysosomal storage diseases (LSDs leads to abnormalities in inflammation and immunity.

  8. lysosome tethering and fusion

    Indian Academy of Sciences (India)

    AMIT TULI

    LYSOSOME. MTOC. LATE ENDOSOME. Arl8b promotes the assembly of the HOPS complex on the lysosomes to mediate late endosome-lysosome fusion and cargo delivery to lysosomes. Khatter D et al., J Cell Science 2015. Khatter D et al., Cellular Logistics 2015 ...

  9. lysosome tethering and fusion

    Indian Academy of Sciences (India)

    AMIT TULI

    Molecular mechanisms regulating endosome- lysosome tethering and fusion. Mahak Sharma. Assistant Professor & Wellcome Trust-DBT Intermediate Fellow. Department of Biological Sciences. IISER-Mohali ...

  10. Lysosomal dysfunction in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Klaudia Tomala

    2017-05-01

    Full Text Available Recent data advocate for the implication of lysosomes in the development of programmed cell death. Lysosomal dysfunction decreased the efficiency of autophagosome/lysosome fusion that leads to vacuolation of cells. Autophagic vacuoles containing damaged organelles and altered proteins are hallmarks in most neurodegenerative disorders. These aggregates consequently disrupt cellular homeostasis causing neuronal cell death due apoptosis or necrosis. Moreover calpain mediated or mutation inducted lysosomal rupture result in release of lysosomal cathepsins into the cytoplasm and inducing neuronal cell death. In this review we emphasize the pathophysiological mechanism connecting disrupting autophagy – lysosomal pathway and lysosomal dysfunction in neuronal cell death called lysosomal cell death.

  11. Lysosomes and radiation injury

    International Nuclear Information System (INIS)

    Watkins, D.K.

    1975-01-01

    Changes in activities of lysosomal enzymes following whole-body treatment with ionizing radiation have long been recognized (e.g., Douglass and Day 1955, Okada et al., 1957). Attempts to explain nuclear damage by cytoplasmic enzyme attack, concentrated most of the earlier work on DNASE II and acid RNASE. Lysosomal enzymes have subsequently been studied in many tissues following whole-body irradiation. The observations coupled with in vitro results from isolated lysosomes, and u.v. and visible light studies on cells in culture, have led to the presentation of tentative mechanisms of action. General methods of detecting lysosomal damage have utilized the consequent activation or leakage of acid hydrolases. As this is of a temporal nature following irradiation, direct damage to the lysosomal membrane has not as yet been measured and the primary lesion either in the membrane itself or at the hypothetical site of acid hydrolase-membrane attachment has still to be discovered. Despite the accumulating evidence of lysosome disruption subsequent to treatment with radiation of various qualities, the role (if any) of these organelles in cell killing remains obscure. In the following pages a review of the many aspects of radiation damage will be presented and an attempt will be made to correlate the results and to draw general conclusions where possible. A final short section will deal with thecontribution that lysosomal damage may make in cell death and tissue injury and possible implications in radiotherapy

  12. Lysosomal storage disorders

    CERN Document Server

    Cabrera-Salazar, Mario A; Cabrera-Salazar, Mario

    2007-01-01

    This book describes the nature of the lysosomal dysfunction and diseases as well as potential future treatments and therapies. This is an invaluable resource for researchers in biochemical and molecular genetics, enzyme therapy, and gene transfer.

  13. 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.

  14. Lysosomes and Brain Health.

    Science.gov (United States)

    Sharma, Jaiprakash; di Ronza, Alberto; Lotfi, Parisa; Sardiello, Marco

    2018-04-16

    One of the fundamental properties of the cell is the capability to digest and remodel its own components according to metabolic and developmental needs. This is accomplished via the autophagy-lysosome system, a pathway of critical importance in the brain, where it contributes to neuronal plasticity and must protect nonreplaceable neurons from the potentially harmful accumulation of cellular waste. The study of lysosomal biogenesis and function in the context of common and rare neurodegenerative diseases has revealed that a dysfunctional autophagy-lysosome system is the shared nexus where multiple, interconnected pathogenic events take place. The characterization of pathways and mechanisms regulating the lysosomal system and autophagic clearance offers unprecedented opportunities for the development of polyvalent therapeutic strategies based on the enhancement of the autophagy-lysosome pathway to maintain cellular homeostasis and achieve neuroprotection. Expected final online publication date for the Annual Review of Neuroscience Volume 41 is July 8, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  15. Lysosomal lipid storage diseases.

    Science.gov (United States)

    Schulze, Heike; Sandhoff, Konrad

    2011-06-01

    Lysosomal lipid storage diseases, or lipidoses, are inherited metabolic disorders in which typically lipids accumulate in cells and tissues. Complex lipids, such as glycosphingolipids, are constitutively degraded within the endolysosomal system by soluble hydrolytic enzymes with the help of lipid binding proteins in a sequential manner. Because of a functionally impaired hydrolase or auxiliary protein, their lipid substrates cannot be degraded, accumulate in the lysosome, and slowly spread to other intracellular membranes. In Niemann-Pick type C disease, cholesterol transport is impaired and unesterified cholesterol accumulates in the late endosome. In most lysosomal lipid storage diseases, the accumulation of one or few lipids leads to the coprecipitation of other hydrophobic substances in the endolysosomal system, such as lipids and proteins, causing a "traffic jam." This can impair lysosomal function, such as delivery of nutrients through the endolysosomal system, leading to a state of cellular starvation. Therapeutic approaches are currently restricted to mild forms of diseases with significant residual catabolic activities and without brain involvement.

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

    Science.gov (United States)

    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 fission in the presence or absence of Chs1/Lyst. Here we show by microscopy, flow cytometry and in vitro fusion that the absence of the Chs1/Lyst protein does not increase the rate of lysosome fusion. Rather, our data indicate that loss of this protein decreases the rate of lysosome fission. We further show that overexpression of the Chs1/Lyst protein gives rise to a faster rate of lysosome fission. These results indicate that Chs1/Lyst regulates lysosome size by affecting fission. PMID:21985295

  17. 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...

  18. Lysosomal exocytosis and lipid storage disorders.

    Science.gov (United States)

    Samie, Mohammad Ali; Xu, Haoxing

    2014-06-01

    Lysosomes are acidic compartments in mammalian cells that are primarily responsible for the breakdown of endocytic and autophagic substrates such as membranes, proteins, and lipids into their basic building blocks. Lysosomal storage diseases (LSDs) are a group of metabolic disorders caused by genetic mutations in lysosomal hydrolases required for catabolic degradation, mutations in lysosomal membrane proteins important for catabolite export or membrane trafficking, or mutations in nonlysosomal proteins indirectly affecting these lysosomal functions. A hallmark feature of LSDs is the primary and secondary excessive accumulation of undigested lipids in the lysosome, which causes lysosomal dysfunction and cell death, and subsequently pathological symptoms in various tissues and organs. There are more than 60 types of LSDs, but an effective therapeutic strategy is still lacking for most of them. Several recent in vitro and in vivo studies suggest that induction of lysosomal exocytosis could effectively reduce the accumulation of the storage materials. Meanwhile, the molecular machinery and regulatory mechanisms for lysosomal exocytosis are beginning to be revealed. In this paper, we first discuss these recent developments with the focus on the functional interactions between lipid storage and lysosomal exocytosis. We then discuss whether lysosomal exocytosis can be manipulated to correct lysosomal and cellular dysfunction caused by excessive lipid storage, providing a potentially general therapeutic approach for LSDs. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  19. BACE is degraded via the lysosomal pathway.

    Science.gov (United States)

    Koh, Young Ho; von Arnim, Christine A F; Hyman, Bradley T; Tanzi, Rudolph E; Tesco, Giuseppina

    2005-09-16

    Amyloid plaques are formed by aggregates of amyloid-beta-peptide, a 37-43-amino acid fragment (primarily Abeta(40) and Abeta(42)) generated by proteolytic processing of the amyloid precursor protein (APP) by beta- and gamma-secretases. A type I transmembrane aspartyl protease, BACE (beta-site APP cleaving enzyme), has been identified to be the beta-secretase. BACE is targeted through the secretory pathway to the plasma membrane where it can be internalized to endosomes. The carboxyl terminus of BACE contains a di-leucine-based signal for sorting of transmembrane proteins to endosomes and lysosomes. In this study, we set out to determine whether BACE is degraded by the lysosomal pathway and whether the di-leucine motif is necessary for targeting BACE to the lysosomes. Here we show that lysosomal inhibitors, chloroquine and NH(4)Cl, lead to accumulation of endogenous and ectopically expressed BACE in a variety of cell types, including primary neurons. Furthermore, the inhibition of lysosomal hydrolases results in the redistribution and accumulation of BACE in the late endosomal/lysosomal compartments (lysosome-associated membrane protein 2 (LAMP2)-positive). In contrast, the BACE-LL/AA mutant, in which Leu(499) and Leu(500) in the COOH-terminal sequence (DDISLLK) were replaced by alanines, only partially co-localized with LAMP2-positive compartments following inhibition of lysosomal hydrolases. Collectively, our data indicate that BACE is transported to the late endosomal/lysosomal compartments where it is degraded via the lysosomal pathway and that the di-leucine motif plays a role in sorting BACE to lysosomes.

  20. Coronary Artery Bypass Surgery

    Science.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Hanna Appelqvist

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Heat shock protein 70 (Hsp70) is an evolutionarily highly conserved molecular chaperone that promotes the survival of stressed cells by inhibiting lysosomal membrane permeabilization, a hallmark of stress-induced cell death. Clues to its molecular mechanism of action may lay in the recently...... reported stress- and cancer-associated translocation of a small portion of Hsp70 to the lysosomal compartment. Here we show that Hsp70 stabilizes lysosomes by binding to an endolysosomal anionic phospholipid bis(monoacylglycero)phosphate (BMP), an essential co-factor for lysosomal sphingomyelin metabolism......-is also associated with a marked decrease in lysosomal stability, and this phenotype can be effectively corrected by treatment with recombinant Hsp70. Taken together, these data open exciting possibilities for the development of new treatments for lysosomal storage disorders and cancer with compounds...

  3. Genetics Home Reference: lysosomal acid lipase deficiency

    Science.gov (United States)

    ... less severe form can begin from childhood to late adulthood. In the severe, early-onset form of lysosomal ... childhood, although they can appear anytime up to late adulthood. Nearly all affected individuals develop an enlarged liver ( ...

  4. Subcellular Nanorheology Reveals Lysosomal Viscosity as a Reporter for Lysosomal Storage Diseases.

    Science.gov (United States)

    Devany, John; Chakraborty, Kasturi; Krishnan, Yamuna

    2018-02-14

    We describe a new method to measure viscosity within subcellular organelles of a living cell using nanorheology. We demonstrate proof of concept by measuring viscosity in lysosomes in multiple cell types and disease models. The lysosome is an organelle responsible for the breakdown of complex biomolecules. When different lysosomal proteins are defective, they are unable to break down specific biological substrates, which get stored within the lysosome, causing about 70 fatal diseases called lysosomal storage disorders (LSDs). Although the buildup of storage material is critical to the pathology of these diseases, methods to monitor cargo accumulation in the lysosome are lacking for most LSDs. Using passive particle tracking nanorheology and fluorescence recovery after photobleaching, we report that viscosity in the lysosome increases significantly during cargo accumulation in several LSD models. In a mammalian cell culture model of Niemann Pick C, lysosomal viscosity directly correlates with the levels of accumulated cholesterol. We also observed increased viscosity in diverse LSD models in Caenorhabditis elegans, revealing that lysosomal viscosity is a powerful reporter with which to monitor substrate accumulation in LSDs for new diagnostics or to assay therapeutic efficacy.

  5. Fasting-induced hormonal regulation of lysosomal function

    OpenAIRE

    Chen, Liqun; Wang, Ke; Long, Aijun; Jia, Liangjie; Zhang, Yuanyuan; Deng, Haiteng; Li, Yu; Han, Jinbo; Wang, Yiguo

    2017-01-01

    Lysosomes are centers for nutrient sensing and recycling that allow mammals to adapt to starvation. Regulation of lysosome dynamics by internal nutrient signaling is well described, but the mechanisms by which external cues modulate lysosomal function are unclear. Here, we describe an essential role of the fasting-induced hormone fibroblast growth factor 21 (FGF21) in lysosome homeostasis in mice. Fgf21 deficiency impairs hepatic lysosomal function by blocking transcription factor EB (TFEB), ...

  6. Lysosomal Storage Disorders and Malignancy

    Directory of Open Access Journals (Sweden)

    Gregory M. Pastores

    2017-02-01

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

  7. [Application of lysosomal detection in marine pollution monitoring: research progress].

    Science.gov (United States)

    Weng, You-Zhu; Fang, Yong-Qiang; Zhang, Yu-Sheng

    2013-11-01

    Lysosome is an important organelle existing in eukaryotic cells. With the development of the study on the structure and function of lysosome in recent years, lysosome is considered as a target of toxic substances on subcellular level, and has been widely applied abroad in marine pollution monitoring. This paper summarized the biological characteristics of lysosomal marker enzyme, lysosome-autophagy system, and lysosomal membrane, and introduced the principles and methods of applying lysosomal detection in marine pollution monitoring. Bivalve shellfish digestive gland and fish liver are the most sensitive organs for lysosomal detection. By adopting the lysosomal detection techniques such as lysosomal membrane stability (LMS) test, neutral red retention time (NRRT) assay, morphological measurement (MM) of lysosome, immunohistochemical (Ih) assay of lysosomal marker enzyme, and electron microscopy (EM), the status of marine pollution can be evaluated. It was suggested that the lysosome could be used as a biomarker for monitoring marine environmental pollution. The advantages and disadvantages of lysosomal detection and some problems worthy of attention were analyzed, and the application prospects of lysosomal detection were discussed.

  8. Lysosomal fusion and SNARE function are impaired by cholesterol accumulation in lysosomal storage disorders.

    Science.gov (United States)

    Fraldi, Alessandro; Annunziata, Fabio; Lombardi, Alessia; Kaiser, Hermann-Josef; Medina, Diego Luis; Spampanato, Carmine; Fedele, Anthony Olind; Polishchuk, Roman; Sorrentino, Nicolina Cristina; Simons, Kai; Ballabio, Andrea

    2010-11-03

    The function of lysosomes relies on the ability of the lysosomal membrane to fuse with several target membranes in the cell. It is known that in lysosomal storage disorders (LSDs), lysosomal accumulation of several types of substrates is associated with lysosomal dysfunction and impairment of endocytic membrane traffic. By analysing cells from two severe neurodegenerative LSDs, we observed that cholesterol abnormally accumulates in the endolysosomal membrane of LSD cells, thereby reducing the ability of lysosomes to efficiently fuse with endocytic and autophagic vesicles. Furthermore, we discovered that soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors (SNAREs), which are key components of the cellular membrane fusion machinery are aberrantly sequestered in cholesterol-enriched regions of LSD endolysosomal membranes. This abnormal spatial organization locks SNAREs in complexes and impairs their sorting and recycling. Importantly, reducing membrane cholesterol levels in LSD cells restores normal SNARE function and efficient lysosomal fusion. Our results support a model by which cholesterol abnormalities determine lysosomal dysfunction and endocytic traffic jam in LSDs by impairing the membrane fusion machinery, thus suggesting new therapeutic targets for the treatment of these disorders.

  9. Lysosome Enlargement Enhanced Photochemotherapy Using a Multifunctional Nanogel.

    Science.gov (United States)

    Zhang, Weiqi; Tung, Ching-Hsuan

    2018-02-07

    Large lysosomes are susceptible toward rupture because of an increased membrane tension. Here we report a strategy to first enlarge and weaken the lysosome and then destroy it to boost the efficiency of photochemotherapy using a hyaluronan nanogel, carrying chloroquine as a lysosomal expander, rhodamine B as a photosensitive lysosomal destroyer, and cisplatin as a chemotherapeutic. This all-in-one nanogel provides a facile approach and new insight into improve the photochemotherapy, by making use of lysosome's size, as a risk factor in lysosomal destabilization.

  10. Cardiopulmonary bypass and hemostasis

    NARCIS (Netherlands)

    Eijsman, Leon

    1992-01-01

    In chapter 1, we recalled that intracardiac defects can only be corrected when cardiopulmonary circulation is maintained by extracorporeal criculation and ventilation. To prevent clot formation in this artificial circuit, the socalled cardiopulmonary bypass (CPB), we completely depend on the

  11. Arterial bypass leg - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100155.htm Arterial bypass leg - series—Normal anatomy To use the sharing features ... Overview The arteries which supply blood to the leg originate from the aorta and iliac vessels. Review ...

  12. Coronary Artery Bypass Grafting

    Science.gov (United States)

    ... lung bypass machine is used during this procedure. Robot-assisted technique. This type of procedure allows for ... driving after 3 to 8 weeks. Returning to work after 6 weeks is common unless your job ...

  13. Transport of Lysosome-Related Organelles

    NARCIS (Netherlands)

    Jordens, Ingrid

    2005-01-01

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

  14. Prenatal diagnosis of lysosomal storage diseases using fetal blood

    NARCIS (Netherlands)

    Groener, J. E.; de Graaf, F. L.; Poorthuis, B. J.; Kanhai, H. H.

    1999-01-01

    Lysosomal storage diseases are a rare but significant cause of non-immune hydrops fetalis (NIHF). In 17 cases of NIHF detected by ultrasound, the activity of five lysosomal enzymes was measured in leukocytes or plasma of 1 ml of fetal blood obtained by cordocentesis. By this approach seven lysosomal

  15. 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.

  16. 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.

  17. Autophagy, lipophagy and lysosomal lipid storage disorders.

    Science.gov (United States)

    Ward, Carl; Martinez-Lopez, Nuria; Otten, Elsje G; Carroll, Bernadette; Maetzel, Dorothea; Singh, Rajat; Sarkar, Sovan; Korolchuk, Viktor I

    2016-04-01

    Autophagy is a catabolic process with an essential function in the maintenance of cellular and tissue homeostasis. It is primarily recognised for its role in the degradation of dysfunctional proteins and unwanted organelles, however in recent years the range of autophagy substrates has also been extended to lipids. Degradation of lipids via autophagy is termed lipophagy. The ability of autophagy to contribute to the maintenance of lipo-homeostasis becomes particularly relevant in the context of genetic lysosomal storage disorders where perturbations of autophagic flux have been suggested to contribute to the disease aetiology. Here we review recent discoveries of the molecular mechanisms mediating lipid turnover by the autophagy pathways. We further focus on the relevance of autophagy, and specifically lipophagy, to the disease mechanisms. Moreover, autophagy is also discussed as a potential therapeutic target in several key lysosomal storage disorders. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Intracellular sphingosine releases calcium from lysosomes

    Science.gov (United States)

    Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

    2015-01-01

    To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC. DOI: http://dx.doi.org/10.7554/eLife.10616.001 PMID:26613410

  19. Ultraviolet induced lysosome activity in corneal epithelium

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A 5.000 W Xe-Hg high pressure lamp and a double monochromator were used to produce a 3.3 nm half-bandpass ultraviolet radiation at 295 nm. Pigmented rabbit eyes were irradiated with radiant exposures from 140 Jm -2 to 10.000 Jm -2 and evaluated by slit-lamp biomicroscopy, light and electron microscopy. Corneal threshold (Hsub(c) was 200 Jm -2 and lens threshold (Hsub(L)) was 7.500 Jm -2 . The most repeatable and reliable corneal response to these levels of UV was the development of corneal epithelial granules. Histological changes included a loss of superficial epithelial cells and selective UV induced autolysis of the wing cells. It is suggested that the biomicroscopically observed granules are the clinical manifestation of the secondary lysosomes revealed by light and electron microscopy. It is proposed that UV breaks down the primary lysosome membranes to release hydrolytic enzymes which in turn form the secondary lysosomes during autolysis. Extreme levels of radiant exposure at 295 nm result in indiscriminate destruction of all layers of the corneal epithelium, but the posterior cornea was spared. (orig.) [de

  20. Lysosomal Re-acidification Prevents Lysosphingolipid-Induced Lysosomal Impairment and Cellular Toxicity.

    Directory of Open Access Journals (Sweden)

    Christopher J Folts

    2016-12-01

    Full Text Available Neurodegenerative lysosomal storage disorders (LSDs are severe and untreatable, and mechanisms underlying cellular dysfunction are poorly understood. We found that toxic lipids relevant to three different LSDs disrupt multiple lysosomal and other cellular functions. Unbiased drug discovery revealed several structurally distinct protective compounds, approved for other uses, that prevent lysosomal and cellular toxicities of these lipids. Toxic lipids and protective agents show unexpected convergence on control of lysosomal pH and re-acidification as a critical component of toxicity and protection. In twitcher mice (a model of Krabbe disease [KD], a central nervous system (CNS-penetrant protective agent rescued myelin and oligodendrocyte (OL progenitors, improved motor behavior, and extended lifespan. Our studies reveal shared principles relevant to several LSDs, in which diverse cellular and biochemical disruptions appear to be secondary to disruption of lysosomal pH regulation by specific lipids. These studies also provide novel protective strategies that confer therapeutic benefits in a mouse model of a severe LSD.

  1. The Best Bypass Surgery Trial

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  2. Heart bypass surgery - discharge

    Science.gov (United States)

    ... trouble with short-term memory or feel confused ("fuzzy-headed") Be tired or not have much energy ... or a fever over 101°F (38.3°C). Alternative Names Off-pump coronary artery bypass - discharge; ...

  3. Gastric bypass surgery

    Science.gov (United States)

    ... Buchwald H, ed. Buchwald's Atlas of Metabolic and Bariatric Surgical Techniques and Procedures . Philadelphia, PA: Elsevier Saunders; 2012:chap 5. Halperin F, Ding SA, Simonson DC, et al. Roux-en-Y gastric bypass surgery or lifestyle with intensive medical management in patients ...

  4. Partial Ileal Bypass Undone

    NARCIS (Netherlands)

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

    1984-01-01

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

  5. 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). ...

  6. Characterization of lysosomes and lysosomal enzymes from Chediak-Higashi-syndrome cultured fibroblasts.

    Science.gov (United States)

    Miller, A L; Stein, R; Sundsmo, M; Yeh, R Y

    1986-01-01

    Chediak-Higashi-syndrome cultured skin fibroblasts were used to study the possible involvement of lysosomal enzymes and lysosomal dysfunction in this disorder. Our evidence indicated that Chediak-Higashi fibroblasts displayed a significant decrease in the specific activity of the acidic alpha-D-mannosidase (pH 4.2) compared with normal controls. Additional studies revealed a small, but significant, decrease in the rate of degradation of 125I-labelled beta-D-glucosidase that had been endocytosed into Chediak-Higashi cells. PMID:3099770

  7. Cancer-associated lysosomal changes: friends or foes?

    Science.gov (United States)

    Kallunki, T; Olsen, O D; Jäättelä, M

    2013-04-18

    Rapidly dividing and invasive cancer cells are strongly dependent on effective lysosomal function. Accordingly, transformation and cancer progression are characterized by dramatic changes in lysosomal volume, composition and cellular distribution. Depending on one's point of view, the cancer-associated changes in the lysosomal compartment can be regarded as friends or foes. Most of them are clearly transforming as they promote invasive growth, angiogenesis and drug resistance. The same changes can, however, strongly sensitize cells to lysosomal membrane permeabilization and thereby to lysosome-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.

  8. Clinical neurogenetics: neuropathic lysosomal storage disorders.

    Science.gov (United States)

    Pastores, Gregory M; Maegawa, Gustavo H B

    2013-11-01

    The lysosomal storage disorders are a clinically heterogeneous group of inborn errors of metabolism, associated with the accumulation of incompletely degraded macromolecules within several cellular sites. Affected individuals present with a broad range of clinical problems, including hepatosplenomegaly and skeletal dysplasia. Onset of symptoms may range from birth to adulthood. Most are associated with neurologic features. Later-onset forms are often misdiagnosed as symptoms, which might include psychiatric manifestations, are slowly progressive, and may precede other neurologic or systemic features. Symptomatic care, which remains the mainstay for most subtypes, can lead to significant improvement in quality of life. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. 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

  10. 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

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

    Directory of Open Access Journals (Sweden)

    Ju-Hyun Lee

    2015-09-01

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

  12. The lysosomal enzyme receptor protein (LERP is not essential, but is implicated in lysosomal function in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Medina Hasanagic

    2015-10-01

    Full Text Available The lysosomal enzyme receptor protein (LERP of Drosophila melanogaster is the ortholog of the mammalian cation-independent mannose 6-phosphate (Man 6-P receptor, which mediates trafficking of newly synthesized lysosomal acid hydrolases to lysosomes. However, flies lack the enzymes necessary to make the Man 6-P mark, and the amino acids implicated in Man 6-P binding by the mammalian receptor are not conserved in LERP. Thus, the function of LERP in sorting of lysosomal enzymes to lysosomes in Drosophila is unclear. Here, we analyze the consequence of LERP depletion in S2 cells and intact flies. RNAi-mediated knockdown of LERP in S2 cells had little or no effect on the cellular content or secretion of several lysosomal hydrolases. We generated a novel Lerp null mutation, LerpF6, which abolishes LERP protein expression. Lerp mutants have normal viability and fertility and display no overt phenotypes other than reduced body weight. Lerp mutant flies exhibit a 30–40% decrease in the level of several lysosomal hydrolases, and are hypersensitive to dietary chloroquine and starvation, consistent with impaired lysosome function. Loss of LERP also enhances an eye phenotype associated with defective autophagy. Our findings implicate Lerp in lysosome function and autophagy.

  13. Cardiopulmonary bypass in pregnancy

    OpenAIRE

    Mukul Chandra Kapoor

    2014-01-01

    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 f...

  14. Expanding Newborn Screening for Lysosomal Disorders: Opportunities and Challenges

    Science.gov (United States)

    Waggoner, Darrel J.; Tan, Christopher A.

    2011-01-01

    Newborn screening (NBS), since its implementation in the 1960s, has traditionally been successful in reducing mortality and disability in children with a range of different conditions. Lysosomal storage disorders (LSD) are a heterogeneous group of inherited metabolic diseases that result from lysosomal dysfunction. Based on available treatment and…

  15. Fluorometric Assessment Of Lysosomal Enzymes In Garlic Oil ...

    African Journals Online (AJOL)

    The effect of Garlic oil on Lysosomal enzymes in streptozotocin-induced diabetic rats were investigated fluorometrically. The serum lysosomal enzymes assayed include β-glucuronidase, N-acetylglucosaminidase (NAG) β-D-galactosidase and α-D-galactosidase. The results of the study in nMole-4Mu/hr/ml show that ...

  16. Extracellular Acidification Alters Lysosomal Trafficking in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Kristine Glunde

    2003-11-01

    Full Text Available Cancer cells invade by secreting degradative enzymes, which are sequestered in lysosomal vesicles. In this study, the impact of an acidic extracellular environment on lysosome size, number, and distance from the nucleus in human mammary epithelial cells (HMECs and breast cancer cells of different degrees of malignancy was characterized because the physiological microenvironment of tumors is frequently characterized by extracellular acidity. An acidic extracellular pH (pHe resulted in a distinct shift of lysosomes from the perinuclear region to the cell periphery irrespective of the HMECs' degree of malignancy. With decreasing pH, larger lysosomal vesicles were observed more frequently in highly metastatic breast cancer cells, whereas smaller lysosomes were observed in poorly metastatic breast cancer cells and HMECs. The number of lysosomes decreased with acidic pH values. The displacement of lysosomes to the cell periphery driven by extracellular acidosis may facilitate exocytosis of these lysosomes and increase secretion of degradative enzymes. Filopodia formations, which were observed more frequently in highly metastatic breast cancer cells maintained at acidic pHe, may also contribute to invasion.

  17. Lysosomal and Mitochondrial Liaisons in Niemann-Pick Disease

    Directory of Open Access Journals (Sweden)

    Sandra Torres

    2017-11-01

    Full Text Available Lysosomal storage disorders (LSD are characterized by the accumulation of diverse lipid species in lysosomes. Niemann-Pick type A/B (NPA/B and type C diseases Niemann-Pick type C (NPC are progressive LSD caused by loss of function of distinct lysosomal-residing proteins, acid sphingomyelinase and NPC1, respectively. While the primary cause of these diseases differs, both share common biochemical features, including the accumulation of sphingolipids and cholesterol, predominantly in endolysosomes. Besides these alterations in lysosomal homeostasis and function due to accumulation of specific lipid species, the lysosomal functional defects can have far-reaching consequences, disrupting intracellular trafficking of sterols, lipids and calcium through membrane contact sites (MCS of apposed compartments. Although MCS between endoplasmic reticulum and mitochondria have been well studied and characterized in different contexts, emerging evidence indicates that lysosomes also exhibit close proximity with mitochondria, which translates in their mutual functional regulation. Indeed, as best illustrated in NPC disease, alterations in the lysosomal-mitochondrial liaisons underlie the secondary accumulation of specific lipids, such as cholesterol in mitochondria, resulting in mitochondrial dysfunction and defective antioxidant defense, which contribute to disease progression. Thus, a better understanding of the lysosomal and mitochondrial interactions and trafficking may identify novel targets for the treatment of Niemann-Pick disease.

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

    Science.gov (United States)

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

    2015-04-17

    Lysosomes are ubiquitous membrane-enclosed organelles filled with an acidic interior and are central to the autophagic, endocytic, or phagocytic pathway. In contrast to its classical function as the waste management machinery, lysosomes are now considered to be an integral part of various cellular signaling processes. The diverse functionality of this single organelle requires a very complex and coordinated regulation of its activity with transcription factor EB (TFEB), a master regulator of lysosomal biogenesis, at its core. However, mechanisms by which TFEB is regulated are poorly understood. This study demonstrates that gemfibrozil, an agonist of peroxisome proliferator-activated receptor (PPAR) α, alone and in conjunction with all-trans-retinoic acid is capable of enhancing TFEB in brain cells. We also observed that PPARα, but not PPARβ and PPARγ, is involved in gemfibrozil-mediated up-regulation of TFEB. Reporter assay and chromatin immunoprecipitation studies confirmed the recruitment of retinoid X receptor α, PPARα, and PGC1α on the PPAR-binding site on the Tfeb promoter as well. Subsequently, the drug-mediated induction of TFEB caused an increase in lysosomal protein and the lysosomal abundance in cell. Collectively, this study reinforces the link between lysosomal biogenesis and lipid metabolism with TFEB at the crossroads. Furthermore, gemfibrozil may be of therapeutic value in the treatment of lysosomal storage disorders in which autophagy-lysosome pathway plays an important role. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Variable clinical presentation in lysosomal storage disorders.

    Science.gov (United States)

    Beck, M

    2001-01-01

    Extensive clinical heterogeneity is seen in lysosomal storage disorders, regarding the age of onset and severity of symptoms, the organs involved, and effects on the central nervous system. A broad phenotypic spectrum is seen, for example, in mucopolysaccharidosis type I (Hurler/Scheie disease), Gaucher disease, the several forms of GM2-gangliosidosis and the different manifestations of beta-galactosidase deficiency (GM1-gangliosidosis and Morquio disease type B). Variable clinical expression of the same enzyme defect is not well understood. The presence of different mutations is only part of the explanation, as intrafamilial variability is observed in many cases. Other mechanisms, for example the effect of specific activators, may also have an influence on phenotype.

  20. Haemodynamics in axillobifemoral bypass grafts

    NARCIS (Netherlands)

    C.H. Wittens

    1992-01-01

    textabstractThis thesis is based on four publications on the subject of graft configuration and haemodynamics in axillobifemoral bypass grafts: 1. A clinical evaluation of 17 patients with axillobifemoral bypass graft operations, performed for various indications. Two important observations were

  1. 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…

  2. Crosstalk between Lysosomes and Mitochondria in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Nicoletta Plotegher

    2017-12-01

    Full Text Available Parkinson's disease (PD is the most common motor neurodegenerative disorder. In most cases the cause of the disease is unknown, while in about 10% of subjects, it is associated with mutations in a number of different genes. Several different mutations in 15 genes have been identified as causing familial forms of the disease, while many others have been identified as risk factors. A striking number of these genes are either involved in the regulation of mitochondrial function or of endo-lysosomal pathways. Mutations affecting one of these two pathways are often coupled with defects in the other pathway, suggesting a crosstalk between them. Moreover, PD-linked mutations in genes encoding proteins with other functions are frequently associated with defects in mitochondrial and/or autophagy/lysosomal function as a secondary effect. Even toxins that impair mitochondrial function and cause parkinsonian phenotypes, such as rotenone, also impair lysosomal function. In this review, we explore the reciprocal relationship between mitochondrial and lysosomal pathways in PD. We will discuss the impact of mitochondrial dysfunction on the lysosomal compartment and of endo-lysosomal defects on mitochondrial function, and explore the roles of both causative genes and genes that are risk factors for PD. Understanding the pathways that govern these interactions should help to define a framework to understand the roles and mechanisms of mitochondrial and lysosomal miscommunication in the pathophysiology of PD.

  3. 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.

  4. Cardiopulmonary bypass in pregnancy.

    Science.gov (United States)

    Kapoor, Mukul Chandra

    2014-01-01

    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.

  5. 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.

  6. 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...... of proteoglycan catabolism and lysosomal function. This blocks autophagy-mediated degradation, causing cytoplasmic accumulation of autophagosomes and autophagic substrates. By targeting miR-95 in cells from MSD patients, we can effectively increase residual SUMF1 expression, allowing for reactivation of sulfatase...... activity and increased clearance of sulfated GAGs. The identification of this regulatory mechanism opens the opportunity for a unique therapeutic approach in MSD patients where the need for exogenous enzyme replacement is circumvented....

  7. Epidemiology of lysosomal storage diseases in Sweden.

    Science.gov (United States)

    Hult, Malin; Darin, Niklas; von Döbeln, Ulrika; Månsson, Jan-Eric

    2014-12-01

    There are more than 50 inherited lysosomal storage diseases (LSDs), and this study examined the incidence of clinically diagnosed LSDs in Sweden. The number of patients diagnosed during 1980-2009 was compiled from the registries of the two Swedish diagnostic laboratories that cover the whole country. We identified 433 patients during the 30-year period, with a total incidence of one in every 6100 births and identified fairly constant annual diagnoses during the last 20 years. Krabbe disease was the most common (one in 39 000) followed by Gaucher disease (one in 47 000), metachromatic leukodystrophy and Salla disease. Gaucher disease was more frequent in Sweden than other European countries, due to a founder effect of the mutation (p.L444P) in northern Sweden. Metachromatic leukodystrophy was one of the most common LSDs, in common with other countries. Salla disease, which is very rare elsewhere, was the fourth most common, stemming from a founder mutation in the Salla region of northern Finland brought to Sweden by immigration. The collective incidence of LSDs in Sweden was essentially equal to other European countries, but with a somewhat different disease pattern. Our findings have implications for diagnostic algorithms and treatment strategies. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  8. Quantitative modeling of selective lysosomal targeting for drug design

    DEFF Research Database (Denmark)

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

    2008-01-01

    Lysosomes are acidic organelles and are involved in various diseases, the most prominent is malaria. Accumulation of molecules in the cell by diffusion from the external solution into cytosol, lysosome and mitochondrium was calculated with the Fick–Nernst–Planck equation. The cell model considers...... 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...

  9. Acidic nanoparticles are trafficked to lysosomes and restore an acidic lysosomal pH and degradative function to compromised ARPE-19 cells.

    Directory of Open Access Journals (Sweden)

    Gabriel C Baltazar

    Full Text Available Lysosomal enzymes function optimally in acidic environments, and elevation of lysosomal pH can impede their ability to degrade material delivered to lysosomes through autophagy or phagocytosis. We hypothesize that abnormal lysosomal pH is a key aspect in diseases of accumulation and that restoring lysosomal pH will improve cell function. The propensity of nanoparticles to end up in the lysosome makes them an ideal method of delivering drugs to lysosomes. This study asked whether acidic nanoparticles could traffic to lysosomes, lower lysosomal pH and enhance lysosomal degradation by the cultured human retinal pigmented epithelial cell line ARPE-19. Acidic nanoparticles composed of poly (DL-lactide-co-glycolide (PLGA 502 H, PLGA 503 H and poly (DL-lactide (PLA colocalized to lysosomes of ARPE-19 cells within 60 min. PLGA 503 H and PLA lowered lysosomal pH in cells compromised by the alkalinizing agent chloroquine when measured 1 hr. after treatment, with acidification still observed 12 days later. PLA enhanced binding of Bodipy-pepstatin-A to the active site of cathepsin D in compromised cells. PLA also reduced the cellular levels of opsin and the lipofuscin-like autofluorescence associated with photoreceptor outer segments. These observations suggest the acidification produced by the nanoparticles was functionally effective. In summary, acid nanoparticles lead to a rapid and sustained lowering of lysosomal pH and improved degradative activity.

  10. 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.

  11. LAAT-1 is the Lysosomal Lysine/Arginine Transporter that Maintains Amino Acid Homeostasis

    OpenAIRE

    Liu, Bin; Du, Hongwei; Rutkowski, Rachael; Gartner, Anton; Wang, Xiaochen

    2012-01-01

    Defective catabolite export from lysosomes results in lysosomal storage diseases in humans. Mutations in the cystine transporter gene CTNS cause cystinosis, but other lysosomal amino acid transporters are poorly characterized at the molecular level. Here we identified the C. elegans lysosomal lysine/arginine transporter, LAAT-1. Loss of laat-1 caused accumulation of lysine and arginine in enlarged, degradation-defective lysosomes. In mutants of ctns-1 (C. elegans homolog of CTNS), LAAT-1 was ...

  12. Lysosomal storage disorders: Molecular basis and laboratory testing

    Directory of Open Access Journals (Sweden)

    Filocamo Mirella

    2011-03-01

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

  13. Uncovering the role of Snapin in regulating autophagy-lysosomal function.

    Science.gov (United States)

    Cai, Qian; Sheng, Zu-Hang

    2011-04-01

    The autophagy-lysosomal system is the major degradation pathway essential for the maintenance and survival of neurons. This process requires efficient late endocytic transport from distal processes to the soma, in which lysosomes are predominantly localized. However, it is not clear how late endocytic transport has an impact upon neuronal autophagy-lysosomal function. We recently revealed that Snapin acts as a dynein motor adaptor and coordinates retrograde transport and late endosomal-lysosomal trafficking, thus maintaining efficient autophagy-lysosomal function in neurons. Snapin(-/-) neurons display impaired retrograde transport and clustering of late endosomes along neuronal processes, aberrant accumulation of immature lysosomes, and impaired clearance of autolysosomes. Snapin deficiency leads to reduced neuron viability, neurodegeneration, and developmental defects in the central nervous system. Reintroducing the snapin transgene rescues these phenotypes by enhancing the delivery of endosomal cargos to lysosomes and by facilitating autophagy-lysosomal function. Our study suggests that Snapin is a candidate molecular target for autophagy-lysosomal regulation.

  14. LAAT-1 is the lysosomal lysine/arginine transporter that maintains amino acid homeostasis.

    Science.gov (United States)

    Liu, Bin; Du, Hongwei; Rutkowski, Rachael; Gartner, Anton; Wang, Xiaochen

    2012-07-20

    Defective catabolite export from lysosomes results in lysosomal storage diseases in humans. Mutations in the cystine transporter gene CTNS cause cystinosis, but other lysosomal amino acid transporters are poorly characterized at the molecular level. Here, we identified the Caenorhabditis elegans lysosomal lysine/arginine transporter LAAT-1. Loss of laat-1 caused accumulation of lysine and arginine in enlarged, degradation-defective lysosomes. In mutants of ctns-1 (C. elegans homolog of CTNS), LAAT-1 was required to reduce lysosomal cystine levels and suppress lysosome enlargement by cysteamine, a drug that alleviates cystinosis by converting cystine to a lysine analog. LAAT-1 also maintained availability of cytosolic lysine/arginine during embryogenesis. Thus, LAAT-1 is the lysosomal lysine/arginine transporter, which suggests a molecular explanation for how cysteamine alleviates a lysosomal storage disease.

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

    Directory of Open Access Journals (Sweden)

    Mayim E. Wiens

    2017-01-01

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

  16. Unconventional Trafficking of Mammalian Phospholipase D3 to Lysosomes

    Directory of Open Access Journals (Sweden)

    Adriana Carolina Gonzalez

    2018-01-01

    Full Text Available Variants in the phospholipase D3 (PLD3 gene have genetically been linked to late-onset Alzheimer's disease. We present a detailed biochemical analysis of PLD3 and reveal its endogenous localization in endosomes and lysosomes. PLD3 reaches lysosomes as a type II transmembrane protein via a (for mammalian cells uncommon intracellular biosynthetic route that depends on the ESCRT (endosomal sorting complex required for transport machinery. PLD3 is sorted into intraluminal vesicles of multivesicular endosomes, and ESCRT-dependent sorting correlates with ubiquitination. In multivesicular endosomes, PLD3 is subjected to proteolytic cleavage, yielding a stable glycosylated luminal polypeptide and a rapidly degraded N-terminal membrane-bound fragment. This pathway closely resembles the delivery route of carboxypeptidase S to the yeast vacuole. Our experiments reveal a biosynthetic route of PLD3 involving proteolytic processing and ESCRT-dependent sorting for its delivery to lysosomes in mammalian cells.

  17. Salinomycin kills cancer stem cells by sequestering iron in lysosomes

    Science.gov (United States)

    Mai, Trang Thi; Hamaï, Ahmed; Hienzsch, Antje; Cañeque, Tatiana; Müller, Sebastian; Wicinski, Julien; Cabaud, Olivier; Leroy, Christine; David, Amandine; Acevedo, Verónica; Ryo, Akihide; Ginestier, Christophe; Birnbaum, Daniel; Charafe-Jauffret, Emmanuelle; Codogno, Patrice; Mehrpour, Maryam; Rodriguez, Raphaël

    2017-10-01

    Cancer stem cells (CSCs) represent a subset of cells within tumours that exhibit self-renewal properties and the capacity to seed tumours. CSCs are typically refractory to conventional treatments and have been associated to metastasis and relapse. Salinomycin operates as a selective agent against CSCs through mechanisms that remain elusive. Here, we provide evidence that a synthetic derivative of salinomycin, which we named ironomycin (AM5), exhibits a more potent and selective activity against breast CSCs in vitro and in vivo, by accumulating and sequestering iron in lysosomes. In response to the ensuing cytoplasmic depletion of iron, cells triggered the degradation of ferritin in lysosomes, leading to further iron loading in this organelle. Iron-mediated production of reactive oxygen species promoted lysosomal membrane permeabilization, activating a cell death pathway consistent with ferroptosis. These findings reveal the prevalence of iron homeostasis in breast CSCs, pointing towards iron and iron-mediated processes as potential targets against these cells.

  18. Analyzing Lysosome-Related Organelles by Electron Microscopy

    KAUST Repository

    Hurbain, Ilse

    2017-04-29

    Intracellular organelles have a particular morphological signature that can only be appreciated by ultrastructural analysis at the electron microscopy level. Optical imaging and associated methodologies allow to explore organelle localization and their dynamics at the cellular level. Deciphering the biogenesis and functions of lysosomes and lysosome-related organelles (LROs) and their dysfunctions requires their visualization and detailed characterization at high resolution by electron microscopy. Here, we provide detailed protocols for studying LROs by transmission electron microscopy. While conventional electron microscopy and its recent improvements is the method of choice to investigate organelle morphology, immunoelectron microscopy allows to localize organelle components and description of their molecular make up qualitatively and quantitatively.

  19. Current peripheral bypass surgery: various clinical studies

    NARCIS (Netherlands)

    Slaa, Alexander te

    2011-01-01

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

  20. Gluteopopliteal bypass for a compromised groin

    NARCIS (Netherlands)

    Aukema, Tjeerd S.; Legemate, Dink A.

    2009-01-01

    Extra-anatomic arterial reconstruction is indicated in patients with a compromised groin. Surgical options include obturator or transosseous bypass. We present a case of a patient with a necrotic radiation ulcer in the groin treated with a gluteopopliteal bypass

  1. Heart bypass surgery - minimally invasive - discharge

    Science.gov (United States)

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

  2. Secondary and College LD Bypass Strategies.

    Science.gov (United States)

    Mosby, Robert J.

    1981-01-01

    The author describes the Developmental By-Pass (DBP) Instructional technology for teaching secondary and college learning disabled (LD) students by allowing students to bypass ordering and organizational deficits. (SB)

  3. Collins' bypass for the main ring

    International Nuclear Information System (INIS)

    Ohnuma, S.

    1982-01-01

    Design of the bypass for the main ring at Fermilab is discussed. Specific design features discussed include space, path length, geometric closure, matching of betatron functions, and external dispersion. Bypass parameters are given

  4. Controversy surrounding 'mini' gastric bypass.

    Science.gov (United States)

    Mahawar, Kamal K; Carr, William R J; Balupuri, Shlok; Small, Peter K

    2014-02-01

    Mini gastric bypass is a modification of Mason loop gastric bypass with a longer lesser curvature-based pouch. Though it has been around for more than 15 years, its uptake by the bariatric community has been relatively slow, and the procedure has been mired in controversy right from its early days. Lately, there seems to be a surge in the interest in this procedure, and there is now published experience with more than 5,000 procedures globally. This review examines the major controversial aspects of this procedure against the available scientific literature. Surgeons performing this procedure need to be aware of these controversies and counsel their patients appropriately.

  5. Real-Time Visualization of Lysosome Destruction Using a Photosensitive Toluidine Blue Nanogel.

    Science.gov (United States)

    Zhang, Weiqi; Tung, Ching-Hsuan

    2018-02-09

    Breaking the lysosome helps its sequestered payloads access their molecular targets in cells and thus enhances the intracellular drug delivery. Current strategies for lysosomal escape involve direct physical interactions with the lipid membrane. These interactions pose a systemic toxicity and uncontrolled membrane rupture risk. Here, we report a light-detonated lysosome disruption using a hyaluronan (HA) nanogel packed with toludine blue (TB). The HA/TB nanogel is concentrated within the lysosomes. The applied light assists TB in generating reactive oxygen species and destroying the lysosome in situ, both in cells and isolated lysosomes. Real time fluorescent tracking reveals that quenched TB fluorescence recovers along with lysosome explosion, relocates to the nucleus, and is presented as a fluorescent sparkling in cells. This HA/TB, composed of all clinically approved materials, represents a biocompatible and facile strategy to "bomb" lysosomes in a spatiotemporally controlled fashion. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Haemoglobin and Lung Total and Lysosomal Phosphatase Activity ...

    African Journals Online (AJOL)

    Comparisons were made of the effect of Benson & Hedges cigarette (filter-tipped) and Captain Black cigar (Non filter-tipped) smoke on rat plasma haemoglobin, carboxy-haemoglobin and nicotine levels, average body weight and daily feed intake, lung Total and lysosomal acid phosphatase activity. The results showed that ...

  7. 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.

  8. Assessments of lysosomal membrane responses to stresses with ...

    African Journals Online (AJOL)

    In marine bivalves, it has been demonstrated that their lysosomal membrane stability are very susceptible to many internal and external environmental changes and this physiological response can be quantified by the neutral red retention (NRR) assay. This assay has been applied in many recent studies in the areas of ...

  9. Lysosomal multienzyme complex: biochemistry, genetics, and molecular pathophysiology.

    Science.gov (United States)

    Pshezhetsky, A V; Ashmarina, M

    2001-01-01

    Lysosomal enzymes sialidase (alpha-neuraminidase), beta-galactosidase, and N-acetylaminogalacto-6-sulfate sulfatase are involved in the catabolism of glycolipids, glycoproteins, and oligosaccharides. Their functional activity in the cell depends on their association in a multienzyme complex with lysosomal carboxypeptidase, cathepsin A. We review the data suggesting that the integrity of the complex plays a crucial role at different stages of biogenesis of lysosomal enzymes, including intracellular sorting and proteolytic processing of their precursors. The complex plays a protective role for all components, extending their half-life in the lysosome from several hours to several days; and for sialidase, the association with cathepsin A is also necessary for the expression of enzymatic activity. The disintegration of the complex due to genetic mutations in its components results in their functional deficiency and causes severe metabolic disorders: sialidosis (mutations in sialidase), GM1-gangliosidosis and Morquio disease type B (mutations in beta-galactosidase), galactosialidosis (mutations in cathepsin A), and Morquio disease type A (mutations in N-acetylaminogalacto-6-sulfate sulfatase). The genetic, biochemical, and direct structural studies described here clarify the molecular pathogenic mechanisms of these disorders and suggest new diagnostic tools.

  10. Inhibition of substrate synthesis as a strategy for glycolipid lysosomal storage disease therapy

    NARCIS (Netherlands)

    Platt, F. M.; Jeyakumar, M.; Andersson, U.; Priestman, D. A.; Dwek, R. A.; Butters, T. D.; Cox, T. M.; Lachmann, R. H.; Hollak, C.; Aerts, J. M.; van Weely, S.; Hrebícek, M.; Moyses, C.; Gow, I.; Elstein, D.; Zimran, A.

    2001-01-01

    The glycosphingolipid (GSL) lysosomal storage diseases are caused by mutations in the genes encoding the glycohydrolases that catabolize GSLs within lysosomes. In these diseases the substrate for the defective enzyme accumulates in the lysosome and the stored GSL leads to cellular dysfunction and

  11. 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

  12. A lysosome-locating and acidic pH-activatable fluorescent probe for visualizing endogenous H2O2 in lysosomes.

    Science.gov (United States)

    Liu, Jun; Zhou, Shunqing; Ren, Jing; Wu, Chuanliu; Zhao, Yibing

    2017-11-20

    There is increasing evidence indicating that lysosomal H 2 O 2 is closely related to autophagy and apoptotic pathways under both physiological and pathological conditions. Therefore, fluorescent probes that can be exploited to visualize H 2 O 2 in lysosomes are potential tools for exploring diverse roles of H 2 O 2 in cells. However, functional exploration of lysosomal H 2 O 2 is limited by the lack of fluorescent probes capable of compatibly sensing H 2 O 2 under weak acidic conditions (pH = 4.5) of lysosomes. Lower spatial resolution of the fluorescent visualization of lysosomal H 2 O 2 might be caused by the interference of signals from cytosolic and mitochondrial H 2 O 2 , as well as the non-specific distribution of the probes in cells. In this work, we developed a lysosome-locating and acidic-pH-activatable fluorescent probe for the detection and visualization of H 2 O 2 in lysosomes, which consists of a H 2 O 2 -responsive boronate unit, a lysosome-locating morpholine group, and a pH-activatable benzorhodol fluorophore. The response of the fluorescent probe to H 2 O 2 is significantly more pronounced under acidic pH conditions than that under neutral pH conditions. Notably, the present probe enables the fluorescence sensing of endogenous lysosomal H 2 O 2 in living cells without external stimulations, with signal interference from the cytoplasm and other intracellular organelles being negligible.

  13. Autophagic dysfunction in a lysosomal storage disorder due to impaired proteolysis.

    Science.gov (United States)

    Elrick, Matthew J; Lieberman, Andrew P

    2013-02-01

    Alterations in macroautophagy (hereafter referred to as "autophagy") are a common feature of lysosomal storage disorders, and have been hypothesized to play a major role in the pathogenesis of these diseases. We have recently reported multiple defects in autophagy contributing to the lysosomal storage disorder Niemann-Pick type C (NPC). These include increased formation of autophagosomes, slowed turnover of autophagosomes secondary to impaired lysosomal proteolysis, and delivery of stored lipids to the lysosome via autophagy. The study summarized here describes novel methods for the interrogation of individual stages of the autophagic pathway, and suggests mechanisms by which lipid storage may result in broader lysosomal dysfunction.

  14. Gut hormones and gastric bypass

    DEFF Research Database (Denmark)

    Holst, Jens J.

    2016-01-01

    Gut hormone secretion in response to nutrient ingestion appears to depend on membrane proteins expressed by the enteroendocrine cells. These include transporters (glucose and amino acid transporters), and, in this case, hormone secretion depends on metabolic and electrophysiological events elicited...... that determines hormone responses. It follows that operations that change intestinal exposure to and absorption of nutrients, such as gastric bypass operations, also change hormone secretion. This results in exaggerated increases in the secretion of particularly the distal small intestinal hormones, GLP-1, GLP-2......, oxyntomodulin, neurotensin and peptide YY (PYY). However, some proximal hormones also show changes probably reflecting that the distribution of these hormones is not restricted to the bypassed segments of the gut. Thus, cholecystokinin responses are increased, whereas gastric inhibitory polypeptide responses...

  15. Resolution of lysosomes in living cells with a ratiometric molecular pH-meter.

    Science.gov (United States)

    Li, Zhu; Wu, Shuqi; Han, Jiahuai; Yang, Liu; Han, Shoufa

    2013-09-30

    Intracellular acidic vesicles, constituted mostly by lysosomes, mediated a variety of biological events ranging from endocytosis, apoptosis, to cancer metastasis, etc. A chimeric molecular pH-meter (Lyso-DR), comprised of a dansyl fluorophore and proton activatable rhodamine-lactam, was prepared for ratiometric reporting of intralysosomal acidity. Exclusively confined in lysosomes, Lyso-DR exhibited pH dependent dual fluorescence emission bands which enable resolution of individual lysosomes in terms of acidity and quantitation of the overall intracellular lysosomal acidity, e.g. the lysosomal pH of HeLa cells is around pH 5.0 whereas that of L929 cells is around pH 6.2. Lyso-DR effectively differentiated the lysosomal pH changes of cells undergoing apoptosis vs necrosis, suggesting its utility in investigations on lysosome involved biomedical processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Induced pluripotent stem cell models of lysosomal storage disorders

    Directory of Open Access Journals (Sweden)

    Daniel K. Borger

    2017-06-01

    Full Text Available Induced pluripotent stem cells (iPSCs have provided new opportunities to explore the cell biology and pathophysiology of human diseases, and the lysosomal storage disorder research community has been quick to adopt this technology. Patient-derived iPSC models have been generated for a number of lysosomal storage disorders, including Gaucher disease, Pompe disease, Fabry disease, metachromatic leukodystrophy, the neuronal ceroid lipofuscinoses, Niemann-Pick types A and C1, and several of the mucopolysaccharidoses. Here, we review the strategies employed for reprogramming and differentiation, as well as insights into disease etiology gleaned from the currently available models. Examples are provided to illustrate how iPSC-derived models can be employed to develop new therapeutic strategies for these disorders. We also discuss how models of these rare diseases could contribute to an enhanced understanding of more common neurodegenerative disorders such as Parkinson’s disease, and discuss key challenges and opportunities in this area of research.

  17. A novel transgenic mouse model of lysosomal storage disorder

    OpenAIRE

    Ortiz-Miranda, Sonia; Ji, Rui; Jurczyk, Agata; Aryee, Ken-Edwin; Mo, Shunyan; Fletcher, Terry; Shaffer, Scott A.; Greiner, Dale L.; Bortell, Rita; Gregg, Ronald G.; Cheng, Alan; Hennings, Leah J.; Rittenhouse, Ann R.

    2016-01-01

    We provide an explanation for striking pathology found in a subset of genetically engineered mice homozygous for a rat CaVβ2a transgene (Tg+/+). Multiple transgene (Tg) copies inserted into chromosome 19; at this same site a large deletion occurred, ablating cholesterol 25-hydroxylase and partially deleting lysosomal acid lipase and CD95. Their loss of function can account for lipid build up and immune system hypertrophy, which defines this phenotype and serendipitously provides a novel model...

  18. Mitochondria-associated ER membranes (MAMs) and lysosomal storage diseases.

    Science.gov (United States)

    Annunziata, Ida; Sano, Renata; d'Azzo, Alessandra

    2018-02-28

    Lysosomal storage diseases (LSDs) comprise a large group of disorders of catabolism, mostly due to deficiency of a single glycan-cleaving hydrolase. The consequent endo-lysosomal accumulation of undigested or partially digested substrates in cells of virtually all organs, including the nervous system, is diagnostic of these diseases and underlies pathogenesis. A subgroup of LSDs, the glycosphingolipidoses, are caused by deficiency of glycosidases that process/degrade sphingolipids and glycosphingolipids (GSLs). GSLs are among the lipid constituents of mammalian membranes, where they orderly distribute and, together with a plethora of membrane proteins, contribute to the formation of discrete membrane microdomains or lipid rafts. The composition of intracellular membranes enclosing organelles reflects that at the plasma membrane (PM). Organelles have the tendencies to tether to one another and to the PM at specific membrane contact sites that, owing to their lipid and protein content, resemble PM lipid rafts. The focus of this review is on the MAMs, mitochondria associated ER membranes, sites of juxtaposition between ER and mitochondria that function as biological hubs for the exchange of molecules and ions, and control the functional status of the reciprocal organelles. We will focus on the lipid components of the MAMs, and highlight how failure to digest or process the sialylated GSL, GM1 ganglioside, in lysosomes alters the lipid conformation and functional properties of the MAMs and leads to neuronal cell death and neurodegeneration.

  19. 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.

  20. Newborn Screening for Lysosomal Storage Disorders in Belgium

    Directory of Open Access Journals (Sweden)

    Francois Eyskens MD, PhD

    2017-11-01

    Full Text Available Lysosomal storage disorders (LSDs are a group of metabolic disorders with various clinical presentations, which complicate diagnosis. A pilot study was performed to test the appropriateness and effectiveness of the newborn screening method for Pompe disease, Fabry disease and mucopolysaccharidosis (MPS I in dried blood spots using liquid chromatography–tandem mass spectrometry. Around 20 000 newborn samples were analyzed for 3 lysosomal enzyme activities: α-glucosidase (deficient in Pompe disease, α-galactosidase (deficient in Fabry disease and α-iduronidase (IDUA, deficient in MPS I. Data were used for statistical analysis and to establish sex- and age-dependent reference ranges. Statistically significant higher α-glucosidase, α-galactosidase, and IDUA enzyme activities were observed in female newborns compared to male newborns. Newborns with a higher gestational age have a statistically significant lower α-glucosidase, α-galactosidase, and IDUA enzyme activities compared to newborns with a lower gestational age. For the first time, the data of a large-scale LSD study were used to assess statistical differences in enzyme activity in the newborn population, and these data highlight the importance of using reference intervals for lysosomal enzyme activities in function of sex and gestational age.

  1. Coronary Artery Bypass in Octogenarians

    Directory of Open Access Journals (Sweden)

    Chen-Yen Chien

    2012-09-01

    Full Text Available Prevalence of coronary artery disease (CAD has increased with the expansion of life span among the elderly population in the world. Hence, the issue of the coronary artery bypass in octogenarians has attracted more attention. Recent literature about the topic revealed nearly the same excellent results as those in the younger population under the newly developed operative techniques and improving concept in perioperative management and postoperative care. In this article, we review the current status of the procedure that was thought to be dangerous in the earlier era, including its risk factors, result, and benefit.

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

    Science.gov (United States)

    Raben, Nina; Puertollano, Rosa

    2016-10-06

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

  3. Direct mobilisation of lysosomal Ca2+ triggers complex Ca2+ signals.

    Science.gov (United States)

    Kilpatrick, Bethan S; Eden, Emily R; Schapira, Anthony H; Futter, Clare E; Patel, Sandip

    2013-01-01

    Accumulating evidence implicates acidic organelles of the endolysosomal system as mobilisable stores of Ca(2+) but their relationship to the better-characterised endoplasmic reticulum (ER) Ca(2+) store remains unclear. Here we show that rapid osmotic permeabilisation of lysosomes evokes prolonged, spatiotemporally complex Ca(2+) signals in primary cultured human fibroblasts. These Ca(2+) signals comprised an initial response that correlated with lysosomal disruption and secondary long-lasting spatially heterogeneous Ca(2+) oscillations that required ER-localised inositol trisphosphate receptors. Electron microscopy identified extensive membrane contact sites between lysosomes and the ER. Mobilisation of lysosomal Ca(2+) stores is thus sufficient to evoke ER-dependent Ca(2+) release probably through lysosome-ER membrane contact sites, and akin to the proposed mechanism of action of the Ca(2+) mobilising messenger nicotinic acid adenine dinucleotide phosphate (NAADP). Our data identify functional and physical association of discrete Ca(2+) stores important for the genesis of Ca(2+) signal complexity.

  4. Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

    International Nuclear Information System (INIS)

    Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

    1989-01-01

    We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload

  5. Uncovering the role of Snapin in regulating autophagy-lysosomal function

    OpenAIRE

    Cai, Qian; Sheng, Zu-Hang

    2011-01-01

    The autophagy-lysosomal system is the major degradation pathway essential for the maintenance and survival of neurons. This process re~uires efficient late endocytic transport from distal processes to the soma, in which lysosomes are predominantly localized. However, it is not clear how late endocytic transport has an impact upon neuronal autophagy-lysosomal function. We recently revealed that Snapin acts as a dynein motor adaptor and coordinates retrograde transport and late endosomal-lysoso...

  6. Autophagic dysfunction in a lysosomal storage disorder due to impaired proteolysis

    OpenAIRE

    Elrick, Matthew J.; Lieberman, Andrew P.

    2013-01-01

    Alterations in macroautophagy (hereafter referred to as “autophagy”) are a common feature of lysosomal storage disorders, and have been hypothesized to play a major role in the pathogenesis of these diseases. We have recently reported multiple defects in autophagy contributing to the lysosomal storage disorder Niemann-Pick type C (NPC). These include increased formation of autophagosomes, slowed turnover of autophagosomes secondary to impaired lysosomal proteolysis, and delivery of stored lip...

  7. Role of Lysosomal Enzyme Release in Circulatory Shock and Critical Illness.

    Science.gov (United States)

    1978-06-01

    lysosomal enzyme release.9󈧟" 28 Furthermore, cellular hypoxia in- creases anaerobic glycolysis and results in a metabolic aci- dosis. Since lysosomal...lysosomal enzyme extracts in intact dogs . In their series, infusions of these extracts resulted in hypotension, altered blood coagulation, granulocytopenia...homogenization of dog kidney followed by two sequential ul- tracentrifugations at 15,000 x g. Glenn et al42 subjected dogs to infusions of hepatic

  8. 'Closed' in Situ Vein Infrainguinal Bypass

    NARCIS (Netherlands)

    L.C. van Dijk (Lukas)

    1996-01-01

    textabstractThe autologous greater saphenous vein is considered to be the best bypass material for below knee femoropopliteal and femorocnual arterial reconstructions . . The history of the greater saphenous vein arterial bypass in humans started in 1949, with its first introduction by Kunlin. Upto

  9. A novel transgenic mouse model of lysosomal storage disorder.

    Science.gov (United States)

    Ortiz-Miranda, Sonia; Ji, Rui; Jurczyk, Agata; Aryee, Ken-Edwin; Mo, Shunyan; Fletcher, Terry; Shaffer, Scott A; Greiner, Dale L; Bortell, Rita; Gregg, Ronald G; Cheng, Alan; Hennings, Leah J; Rittenhouse, Ann R

    2016-11-01

    Knockout technology has proven useful for delineating functional roles of specific genes. Here we describe and provide an explanation for striking pathology that occurs in a subset of genetically engineered mice expressing a rat Ca V β2a transgene under control of the cardiac α-myosin heavy chain promoter. Lesions were limited to mice homozygous for transgene and independent of native Cacnb2 genomic copy number. Gross findings included an atrophied pancreas; decreased adipose tissue; thickened, orange intestines; and enlarged liver, spleen, and abdominal lymph nodes. Immune cell infiltration and cell engulfment by macrophages were associated with loss of pancreatic acinar cells. Foamy macrophages diffusely infiltrated the small intestine's lamina propria, while similar macrophage aggregates packed liver and splenic red pulp sinusoids. Periodic acid-Schiff-positive, diastase-resistant, iron-negative, Oil Red O-positive, and autofluorescent cytoplasm was indicative of a lipid storage disorder. Electron microscopic analysis revealed liver sinusoids distended by clusters of macrophages containing intracellular myelin "swirls" and hepatocytes with enlarged lysosomes. Additionally, build up of cholesterol, cholesterol esters, and triglycerides, along with changes in liver metabolic enzyme levels, were consistent with a lipid processing defect. Because of this complex pathology, we examined the transgene insertion site. Multiple transgene copies inserted into chromosome 19; at this same site, an approximate 180,000 base pair deletion occurred, ablating cholesterol 25-hydroxylase and partially deleting lysosomal acid lipase and CD95 Loss of gene function can account for the altered lipid processing, along with hypertrophy of the immune system, which define this phenotype, and serendipitously provides a novel mouse model of lysosomal storage disorder. Copyright © 2016 the American Physiological Society.

  10. Cryptococcus neoformans-induced macrophage lysosome damage crucially contributes to fungal virulence.

    Science.gov (United States)

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

    2015-03-01

    Upon ingestion by macrophages, Cryptococcus neoformans can survive and replicate intracellularly unless the macrophages become classically activated. The mechanism enabling intracellular replication is not fully understood; neither are the mechanisms that allow classical activation to counteract replication. C. neoformans-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 infected host, we developed a novel flow cytometric method for measuring lysosome damage. Increased lysosome damage was found in C. neoformans-containing lung cells compared with C. neoformans-free cells. Among C. neoformans-containing myeloid cells, recently recruited cells displayed lower damage than resident cells, consistent with the protective role of recruited macrophages. The magnitude of lysosome damage correlated with increased C. neoformans replication. Experimental induction of lysosome damage increased C. neoformans replication. Activation of macrophages with IFN-γ abolished macrophage lysosome damage and enabled increased killing of C. neoformans. We conclude that induction of lysosome damage is an important C. neoformans survival strategy and that classical activation of host macrophages counters replication by preventing damage. Thus, therapeutic strategies that decrease lysosomal damage, or increase resistance to such damage, could be valuable in treating cryptococcal infections. Copyright © 2015 by The American Association of Immunologists, Inc.

  11. Lysosomal responses in the digestive gland of the freshwater mussel, Dreissena polymorpha, experimentally exposed to cadmium

    International Nuclear Information System (INIS)

    Giamberini, Laure; Cajaraville, Miren P.

    2005-01-01

    In order to examine the possible use of lysosomal response as a biomarker of freshwater quality, structural changes of lysosomes were measured by image analysis in the digestive gland of the zebra mussel, Dreissena polymorpha, exposed in laboratory conditions to cadmium. Mussels were exposed to the metal (10 and 200 μg/L) for 3 weeks and randomly collected after 7 and 21 days. At each treatment day, digestive tissues were excised and β-glucuronidase activity was revealed in cryotome sections. Four stereological parameters were calculated: lysosomal volume density, lysosomal surface density, lysosomal surface to volume ratio, and lysosomal numerical density. The changes observed in this study reflected a general activation of the lysosomal system, including an increase in both the number and the size of lysosomes in the digestive gland cells of mussels exposed to cadmium. The digestive lysosomal response in zebra mussels was related to exposure time and to metal concentration, demonstrating the potential of this biomarker in freshwater biomonitoring

  12. 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.

  13. Engaging the lysosomal compartment to combat B cell malignancies

    DEFF Research Database (Denmark)

    Gronbaek, K.; Jaattela, M.

    2009-01-01

    The combination of rituximab, a type I anti-CD20 mAb, with conventional chemotherapy has significantly improved the outcome of patients with B cell malignancies. Regardless of this success, many patients still relapse with therapy-resistant disease, highlighting the need for the development of mAbs...... with higher capacity to induce programmed cell death. The so-called type II anti-CD20 mAbs (e.g., tositumomab) that trigger caspase-independent B cell lymphoma cell death in vitro and show superior efficacy as compared with rituximab in eradicating target cells in mouse models are emerging as the next...... 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...

  14. Biogenesis and proteolytic processing of lysosomal DNase II.

    Directory of Open Access Journals (Sweden)

    Susumu Ohkouchi

    Full Text Available Deoxyribonuclease II (DNase II is a key enzyme in the phagocytic digestion of DNA from apoptotic nuclei. To understand the molecular properties of DNase II, particularly the processing, we prepared a polyclonal antibody against carboxyl-terminal sequences of mouse DNase II. In the present study, partial purification of DNase II using Con A Sepharose enabled the detection of endogenous DNase II by Western blotting. It was interesting that two forms of endogenous DNase II were detected--a 30 kDa form and a 23 kDa form. Neither of those forms carried the expected molecular weight of 45 kDa. Subcellular fractionation showed that the 23 kDa and 30 kDa proteins were localized in lysosomes. The processing of DNase II in vivo was also greatly altered in the liver of mice lacking cathepsin L. DNase II that was extracellularly secreted from cells overexpressing DNase II was detected as a pro-form, which was activated under acidic conditions. These results indicate that DNase II is processed and activated in lysosomes, while cathepsin L is involved in the processing of the enzyme.

  15. New therapeutic prospects for the glycosphingolipid lysosomal storage diseases.

    Science.gov (United States)

    Platt, F M; Butters, T D

    1998-08-15

    The glycosphingolipid (GSL) lysosomal storage diseases result from mutations in the genes that encode the enzymes required for glycosphingolipid catabolism within lysosomes. They are relatively rare diseases, but are frequently severe in terms of their pathology. Many involve progressive neurodegeneration, and in the most severe forms result in death in early infancy. The therapeutic options for treating these diseases are limited, and for the majority of these disorders there are currently no therapies available. To date, most research has focused on correcting the genetic lesion by gene therapy or by augmenting the enzyme activity deficient in these patients by introducing fully functional enzyme. This can be achieved by bone marrow transplantation or intravenous infusion of purified or recombinant enzyme (enzyme replacement). Gene therapy and enzyme replacement therapy are disease specific, and pharmacological approaches for the treatment of these disorders have not been fully explored. In this commentary, the problems associated with disease therapy are discussed, and a pharmacological agent (N-butyldeoxynojirimycin) is presented for the potential generic treatment of this family of disorders. Successful prevention of glycosphingolipid storage in a mouse model of Tay-Sachs disease suggests that this strategy merits clinical evaluation.

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

    Directory of Open Access Journals (Sweden)

    Cátia S. Pereira

    2017-02-01

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

  17. Toxoplasma depends on lysosomal consumption of autophagosomes for persistent infection.

    Science.gov (United States)

    Di Cristina, Manlio; Dou, Zhicheng; Lunghi, Matteo; Kannan, Geetha; Huynh, My-Hang; McGovern, Olivia L; Schultz, Tracey L; Schultz, Aric J; Miller, Alyssa J; Hayes, Beth M; van der Linden, Wouter; Emiliani, Carla; Bogyo, Matthew; Besteiro, Sébastien; Coppens, Isabelle; Carruthers, Vern B

    2017-06-19

    Globally, nearly 2 billion people are infected with the intracellular protozoan Toxoplasma gondii 1 . This persistent infection can cause severe disease in immunocompromised people and is epidemiologically linked to major mental illnesses 2 and cognitive impairment 3 . There are currently no options for curing this infection. The lack of effective therapeutics is due partly to a poor understanding of the essential pathways that maintain long-term infection. Although it is known that Toxoplasma replicates slowly within intracellular cysts demarcated with a cyst wall, precisely how it sustains itself and remodels organelles in this niche is unknown. Here, we identify a key role for proteolysis within the parasite lysosomal organelle (the vacuolar compartment or VAC) in turnover of autophagosomes and persistence during neural infection. We found that disrupting a VAC-localized cysteine protease compromised VAC digestive function and markedly reduced chronic infection. Death of parasites lacking the VAC protease was preceded by accumulation of undigested autophagosomes in the parasite cytoplasm. These findings suggest an unanticipated function for parasite lysosomal degradation in chronic infection, and identify an intrinsic role for autophagy in the T. gondii parasite and its close relatives. This work also identifies a key element of Toxoplasma persistence and suggests that VAC proteolysis is a prospective target for pharmacological development.

  18. In situ bypass og diabetes

    DEFF Research Database (Denmark)

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

    1993-01-01

    decreased survival rate was found in diabetics (p 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-diabetic......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...... = 0.005). Critical limb-ischaemia was more often present in diabetic than non-diabetic patients (DM:57%, NDM:36%, p = 0.0002). Diabetic patients had a significantly lower distal anastomosis than non-diabetic patients (p = 0.00001). There were no differences among diabetic and non-diabetic patients...

  19. [Influence of delta-sleep inducing peptide on the state of lysosomal membranes and intensity of lysosomal proteolysis in different rat tissues during physiological aging of the organism].

    Science.gov (United States)

    Kutilin, D S; Bondarenko, T I; Mikhaleva, I I

    2014-01-01

    It is shown that subcutaneous injection of exogenous delta-sleep inducing peptide (DSIP) to rats aged 2-24 months in a dose of 100 μg/kg animal body weight by courses of 5 consecutive days per month has a stabilizing effect on the state of lysosomal membranes in rat tissues (brain, heart muscle and liver) at different ontogenetic stages, and this effect is accompanied by increasing intensity of lysosomal proteolysis in these tissues.

  20. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class II...

  1. 21 CFR 870.4310 - Cardiopulmonary bypass coronary pressure gauge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass coronary pressure gauge... Cardiopulmonary bypass coronary pressure gauge. (a) Identification. A cardiopulmonary bypass coronary pressure gauge is a device used in cardiopulmonary bypass surgery to measure the pressure of the blood perfusing...

  2. Ubiquitination of exposed glycoproteins by SCFFBXO27 directs damaged lysosomes for autophagy

    Science.gov (United States)

    Yoshida, Yukiko; Yasuda, Sayaka; Fujita, Toshiharu; Hamasaki, Maho; Murakami, Arisa; Kawawaki, Junko; Iwai, Kazuhiro; Saeki, Yasushi; Yoshimori, Tamotsu; Matsuda, Noriyuki; Tanaka, Keiji

    2017-01-01

    Ubiquitination functions as a signal to recruit autophagic machinery to damaged organelles and induce their clearance. Here, we report the characterization of FBXO27, a glycoprotein-specific F-box protein that is part of the SCF (SKP1/CUL1/F-box protein) ubiquitin ligase complex, and demonstrate that SCFFBXO27 ubiquitinates glycoproteins in damaged lysosomes to regulate autophagic machinery recruitment. Unlike F-box proteins in other SCF complexes, FBXO27 is subject to N-myristoylation, which localizes it to membranes, allowing it to accumulate rapidly around damaged lysosomes. We also screened for proteins that are ubiquitinated upon lysosomal damage, and identified two SNARE proteins, VAMP3 and VAMP7, and five lysosomal proteins, LAMP1, LAMP2, GNS, PSAP, and TMEM192. Ubiquitination of all glycoproteins identified in this screen increased upon FBXO27 overexpression. We found that the lysosomal protein LAMP2, which is ubiquitinated preferentially on lysosomal damage, enhances autophagic machinery recruitment to damaged lysosomes. Thus, we propose that SCFFBXO27 ubiquitinates glycoproteins exposed upon lysosomal damage to induce lysophagy. PMID:28743755

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

    Directory of Open Access Journals (Sweden)

    Fang Chen

    2016-04-01

    Full Text Available Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O, has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu and Cat D inhibitor (pepA inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05 in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  4. Lysosomal membrane transport : physiological and pathological events / Grazia Maria Simonetta Mancini

    NARCIS (Netherlands)

    G.M.S. Mancini (Grazia)

    1991-01-01

    textabstractThis thesis deals with the identification of a lysosomal transport mechanism for sialic acid. A primary genetic defect of this transport mechanism is demonstrated in patients affected by lysosomal storage of free sialic acid and excessive sialuria (sialic acid storage diseases, SASD). A

  5. Vps33B is required for delivery of endocytosed cargo to lysosomes

    NARCIS (Netherlands)

    Galmes, Romain; ten Brink, Corlinda; Oorschot, Viola; Veenendaal, Tineke; Jonker, Caspar; van der Sluijs, Peter; Klumperman, Judith

    2015-01-01

    In mammalian cells Vps33B forms a complex with VIPAS-39 that is recruited to recycling endosomes. Here we show that when Vps33B is expressed together with Rab7-interacting lysosomal protein (RILP) it is recruited to late endosomes-lysosomes and that depletion of Vps33B impairs late

  6. 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.

  7. Alterations in membrane trafficking and pathophysiological implications in lysosomal storage disorders.

    Science.gov (United States)

    Kuech, Eva-Maria; Brogden, Graham; Naim, Hassan Y

    2016-11-01

    Lysosomal storage disorders are a heterogeneous group of more than 50 distinct inborn metabolic diseases affecting about 1 in 5000 to 7000 live births. The diseases often result from mutations followed by functional deficiencies of enzymes or transporters within the acidic environment of the lysosome, which mediate the degradation of a wide subset of substrates, including glycosphingolipids, glycosaminoglycans, cholesterol, glycogen, oligosaccharides, peptides and glycoproteins, or the export of the respective degradation products from the lysosomes. The progressive accumulation of uncleaved substrates occurs in multiple organs and finally causes a broad spectrum of different pathologies including visceral, neurological, skeletal and hematologic manifestations. Besides deficient lysosomal enzymes and transporters other defects may lead to lysosomal storage disorders, including activator defects, membrane defects or defects in modifier proteins. In this review we concentrate on four different lysosomal storage disorders: Niemann-Pick type C, Fabry disease, Gaucher disease and Pompe disease. While the last three are caused by defective lysosomal hydrolases, Niemann-Pick type C is caused by the inability to export LDL-derived cholesterol out of the lysosome. We want to emphasise potential implications of membrane trafficking defects on the pathology of these diseases, as many mutations interfere with correct lysosomal protein trafficking and alter cellular lipid homeostasis. Current therapeutic strategies are summarised, including substrate reduction therapy as well as pharmacological chaperone therapy which directly aim to improve folding and lysosomal transport of misfolded mutant proteins. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Characterization of Drosophila Saposin-related mutants as a model for lysosomal sphingolipid storage diseases

    Directory of Open Access Journals (Sweden)

    Julia Sellin

    2017-06-01

    Full Text Available Sphingolipidoses are inherited diseases belonging to the class of lysosomal storage diseases (LSDs, which are characterized by the accumulation of indigestible material in the lysosome caused by specific defects in the lysosomal degradation machinery. While some LSDs can be efficiently treated by enzyme replacement therapy (ERT, this is not possible if the nervous system is affected due to the presence of the blood-brain barrier. Sphingolipidoses in particular often present as severe, untreatable forms of LSDs with massive sphingolipid and membrane accumulation in lysosomes, neurodegeneration and very short life expectancy. The digestion of intralumenal membranes within lysosomes is facilitated by lysosomal sphingolipid activator proteins (saposins, which are cleaved from a prosaposin precursor. Prosaposin mutations cause some of the severest forms of sphingolipidoses, and are associated with perinatal lethality in mice, hampering studies on disease progression. We identify the Drosophila prosaposin orthologue Saposin-related (Sap-r as a key regulator of lysosomal lipid homeostasis in the fly. Its mutation leads to a typical spingolipidosis phenotype with an enlarged endolysosomal compartment and sphingolipid accumulation as shown by mass spectrometry and thin layer chromatography. Sap-r mutants show reduced viability with ∼50% survival to adulthood, allowing us to study progressive neurodegeneration and analyze their lipid profile in young and aged flies. Additionally, we observe a defect in sterol homeostasis with local sterol depletion at the plasma membrane. Furthermore, we find that autophagy is increased, resulting in the accumulation of mitochondria in lysosomes, concomitant with increased oxidative stress. Together, we establish Drosophila Sap-r mutants as a lysosomal storage disease model suitable for studying the age-dependent progression of lysosomal dysfunction associated with lipid accumulation and the resulting pathological

  9. Coronary Artery Bypass Surgery - Multiple Languages

    Science.gov (United States)

    ... Coronary Artery Bypass Surgery - 简体中文 (Chinese, Simplified (Mandarin dialect)) Bilingual PDF Health Information Translations Chinese, Traditional (Cantonese dialect) (繁體中文) Expand Section Coronary ...

  10. Role of Lysosomes in gallium concentration by mammalian tissues

    International Nuclear Information System (INIS)

    Berry, J.P.; Galle, S.; Escaig, F.; Poupon, M.F.

    1984-01-01

    Gallium is used as a tracer in nuclear medicine for the localization of malignant tumors. Two microanalytical methods, electron probe X ray analysis (EPMA) and ion mass analysis (IAM) were used to study gallium incorporation in normal tissues (kidney, liver, mammary gland, bone marrow, bone tissue) and in experimental tumors. The very high sensitivity of IMA makes possible the detection of very low cencentration of gallium (1 ppm) with a spatial resolution of 0.5 μm, on the other hand, EPMA of lower sensitivity (100 ppm) makes possible the relation between the gallium concentration and the ultrastructure of the cell. It was shown that gallium is concentrated in the lysosomes of both types of tissues, where it is precipitated in an insoluble form. In addition, gallium is systematically combined with phosphorus in these precipitates. These observations suggest an active intralysosomal concentrating mechanism related to the presence of local phosphatase activity

  11. Septins as modulators of endo-lysosomal membrane traffic

    Directory of Open Access Journals (Sweden)

    Kyungyeun Song

    2016-11-01

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

  12. [Plasma ionized magnesium concentration following cardiopulmonary bypass].

    Science.gov (United States)

    Amaya, Fumimasa; Fukui, Michihiko; Tsuruta, Hiroshi; Kooguchi, Kunihiko; Shimosato, Goshun

    2002-06-01

    We performed a retrospective study to analyze plasma ionized magnesium concentration following cardiopulmonary bypass. Severe decrease of ionized magnesium concentration associated with frequent abnormal ECG sign was found in a patient with magnesium-free cardioplegia. Cardioplegia containing 16 mmol.l-1 of magnesium ion maintained ionized magnesium concentration within normal ranges without postoperative magnesium loading. Use of cardioplegia containing magnesium or adequate magnesium supplement is thought to be essential for patients receiving cardiopulmonary bypass.

  13. Bypass diode for a solar cell

    Science.gov (United States)

    Rim, Seung Bum [Palo Alto, CA; Kim, Taeseok [San Jose, CA; Smith, David D [Campbell, CA; Cousins, Peter J [Menlo Park, CA

    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.

  14. 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.

  15. Organization of the gene encoding human lysosomal beta-galactosidase.

    Science.gov (United States)

    Morreau, H; Bonten, E; Zhou, X Y; D'Azzo, A

    1991-09-01

    Human beta-galactosidase precursor mRNA is alternatively spliced into an abundant 2.5-kb transcript and a minor 2.0-kb species. These templates direct the synthesis of the classic lysosomal beta-D-galactosidase enzyme and of a beta-galactosidase-related protein with no enzymatic activity. Mutations in the beta-galactosidase gene result in the lysosomal storage disorders GM1-gangliosidosis and Morquio B syndrome. To analyze the genetic lesions underlying these syndromes we have isolated the human beta-galactosidase gene and determined its organization. The gene spans greater than 62.5 kb and contains 16 exons. Promoter activity is located on a 236-bp Pst I fragment which works in a direction-independent manner. A second Pst I fragment of 851 bp located upstream from the first negatively regulates initiation of transcription. The promoter has characteristics of a housekeeping gene with GC-rich stretches and five potential SP1 transcription elements on two strands. We identified multiple cap sites of the mRNA, the major of which maps 53 bp upstream from the translation initiation codon. The portion of the human pre-mRNA undergoing alternative splicing is encoded by exons II-VII. Sequence analysis of equivalent mouse exons showed an identical genomic organization. However, translation of the corresponding differentially spliced murine transcript is interrupted in its reading frame. Thus, the mouse gene cannot encode a beta-galactosidase-related protein in a manner similar to the human counterpart. Differential expression of the murine beta-galactosidase transcript is observed in different mouse tissues.

  16. Synergistic Anticancer Action of Lysosomal Membrane Permeabilization and Glycolysis Inhibition.

    Science.gov (United States)

    Kosic, Milica; Arsikin-Csordas, Katarina; Paunovic, Verica; Firestone, Raymond A; Ristic, Biljana; Mircic, Aleksandar; Petricevic, Sasa; Bosnjak, Mihajlo; Zogovic, Nevena; Mandic, Milos; Bumbasirevic, Vladimir; Trajkovic, Vladimir; Harhaji-Trajkovic, Ljubica

    2016-10-28

    We investigated the in vitro and in vivo anticancer effect of combining lysosomal membrane permeabilization (LMP)-inducing agent N-dodecylimidazole (NDI) with glycolytic inhibitor 2-deoxy-d-glucose (2DG). NDI-triggered LMP and 2DG-mediated glycolysis block synergized in inducing rapid ATP depletion, mitochondrial damage, and reactive oxygen species production, eventually leading to necrotic death of U251 glioma cells but not primary astrocytes. NDI/2DG-induced death of glioma cells was partly prevented by lysosomal cathepsin inhibitor E64 and antioxidant α-tocopherol, suggesting the involvement of LMP and oxidative stress in the observed cytotoxicity. LMP-inducing agent chloroquine also displayed a synergistic anticancer effect with 2DG, whereas glucose deprivation or glycolytic inhibitors iodoacetate and sodium fluoride synergistically cooperated with NDI, thus further indicating that the anticancer effect of NDI/2DG combination was indeed due to LMP and glycolysis block. The two agents synergistically induced ATP depletion, mitochondrial depolarization, oxidative stress, and necrotic death also in B16 mouse melanoma cells. Moreover, the combined oral administration of NDI and 2DG reduced in vivo melanoma growth in C57BL/6 mice by inducing necrotic death of tumor cells, without causing liver, spleen, or kidney toxicity. Based on these results, we propose that NDI-triggered LMP causes initial mitochondrial damage that is further increased by 2DG due to the lack of glycolytic ATP required to maintain mitochondrial health. This leads to a positive feedback cycle of mitochondrial dysfunction, ATP loss, and reactive oxygen species production, culminating in necrotic cell death. Therefore, the combination of LMP-inducing agents and glycolysis inhibitors seems worthy of further exploration as an anticancer strategy. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. [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

    Obesity surgery includes various gastrointestinal procedures. Roux-en-Y gastric bypass is the prototype of mixed procedures being the most practiced worldwide. A similar and novel technique has been adopted by Dr. Almino Cardoso Ramos and Dr. Manoel Galvao called "simplified bypass," which has been accepted due to the greater ease and very similar results to the conventional technique. The aim of this study is to describe the results of the simplified gastric bypass for treatment of morbid obesity in our institution. We performed a descriptive, retrospective study of all patients undergoing simplified gastric bypass from January 2008 to July 2012 in the obesity clinic of a private hospital in Mexico City. A total of 90 patients diagnosed with morbid obesity underwent simplified gastric bypass. Complications occurred in 10% of patients; these were more frequent bleeding and internal hernia. Mortality in the study period was 0%. The average weight loss at 12 months was 72.7%. Simplified gastric bypass surgery is safe with good mid-term results and a loss of adequate weight in 71% of cases.

  18. Incorporation of lysosomal sequestration in the mechanistic model for prediction of tissue distribution of basic drugs.

    Science.gov (United States)

    Assmus, Frauke; Houston, J Brian; Galetin, Aleksandra

    2017-11-15

    The prediction of tissue-to-plasma water partition coefficients (Kpu) from in vitro and in silico data using the tissue-composition based model (Rodgers & Rowland, J Pharm Sci. 2005, 94(6):1237-48.) is well established. However, distribution of basic drugs, in particular into lysosome-rich lung tissue, tends to be under-predicted by this approach. The aim of this study was to develop an extended mechanistic model for the prediction of Kpu which accounts for lysosomal sequestration and the contribution of different cell types in the tissue of interest. The extended model is based on compound-specific physicochemical properties and tissue composition data to describe drug ionization, distribution into tissue water and drug binding to neutral lipids, neutral phospholipids and acidic phospholipids in tissues, including lysosomes. Physiological data on the types of cells contributing to lung, kidney and liver, their lysosomal content and lysosomal pH were collated from the literature. The predictive power of the extended mechanistic model was evaluated using a dataset of 28 basic drugs (pK a ≥7.8, 17 β-blockers, 11 structurally diverse drugs) for which experimentally determined Kpu data in rat tissue have been reported. Accounting for the lysosomal sequestration in the extended mechanistic model improved the accuracy of Kpu predictions in lung compared to the original Rodgers model (56% drugs within 2-fold or 88% within 3-fold of observed values). Reduction in the extent of Kpu under-prediction was also evident in liver and kidney. However, consideration of lysosomal sequestration increased the occurrence of over-predictions, yielding overall comparable model performances for kidney and liver, with 68% and 54% of Kpu values within 2-fold error, respectively. High lysosomal concentration ratios relative to cytosol (>1000-fold) were predicted for the drugs investigated; the extent differed depending on the lysosomal pH and concentration of acidic phospholipids among

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

    Science.gov (United States)

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

    2014-04-01

    In estuaries and coastal areas, intertidal organisms may be subject to thermal stress resulting from global warming, together with pollution. In the present study, the combined effects of thermal stress and exposure to Cd were investigated in the endo-lysosomal system of digestive cells in mussels, Mytilus galloprovincialis. Mussels were maintained for 24h at 18°C and 26°C seawater temperature in absence and presence of 50 μg Cd/L seawater. Cadmium accumulation in digestive gland tissue, lysosomal structural changes and membrane stability were determined. Semi-quantitative PCR was applied to reveal the changes elicited by the different experimental conditions in hexosaminidase (hex), β-glucuronidase (gusb), cathepsin L (ctsl) and heat shock protein 70 (hsp70) gene transcription levels. Thermal stress provoked lysosomal enlargement whilst Cd-exposure led to fusion of lysosomes. Both thermal stress and Cd-exposure caused lysosomal membrane destabilisation. hex, gusb and ctsl genes but not hsp70 gene were transcriptionally up-regulated as a result of thermal stress. In contrast, all the studied genes were transcriptionally down-regulated in response to Cd-exposure. Cd bioaccumulation was comparable at 18°C and 26°C seawater temperatures but interactions between thermal stress and Cd-exposure were remarkable both in lysosomal biomarkers and in gene transcription. hex, gusb and ctsl genes, reacted to elevated temperature in absence of Cd but not in Cd-exposed mussels. Therefore, thermal stress resulting from global warming might influence the use and interpretation of lysosomal biomarkers in marine pollution monitoring programmes and, vice versa, the presence of pollutants may condition the capacity of mussels to respond against thermal stress in a climate change scenario. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Tubular lysosome morphology and distribution within macrophages depend on the integrity of cytoplasmic microtubules

    International Nuclear Information System (INIS)

    Swanson, J.; Bushnell, A.; Silverstein, S.C.

    1987-01-01

    Pinocytosis of the fluorescent dye lucifer yellow labels elongated, membrane-bound tubular organelles in several cell types, including cultured human monocytes, thioglycolate-elicited mouse peritoneal macrophages, and the macrophage-like cell line J774.2. These tubular structures can be identified as lysosomes by acid phosphatase histochemistry and immunofluorescence localization of cathepsin L. The abundance of tubular lysosomes is markedly increased by treatment with phorbol 12-myristate 13-acetate. When labeled by pinocytosis of microperoxidase and examined by electron microscopic histochemistry, the tubular lysosomes have an outside diameter of ≅ 75 nm and a length of several micrometers; they radiate from the cell's centrosphere in alignment with cytoplasmic microtubules and intermediate filaments. Incubation of phorbol myristate acetate-treated macrophages at 4 0 C or in medium containing 5 μM colchicine or nocodazole at 37 0 C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 37 0 C or removal of nocodazole from the medium leads to reassembly of microtubules and the reappearance of tubular lysosomes within 10-20 min. The authors conclude that microtubules are essential for the maintenance of tubular lysosome morphology and that, in macrophages, a significant proportion of the lysosomal compartment is contained within these tubular structures

  1. Impaired JIP3-dependent axonal lysosome transport promotes amyloid plaque pathology.

    Science.gov (United States)

    Gowrishankar, Swetha; Wu, Yumei; Ferguson, Shawn M

    2017-10-02

    Lysosomes robustly accumulate within axonal swellings at Alzheimer's disease (AD) amyloid plaques. However, the underlying mechanisms and disease relevance of such lysosome accumulations are not well understood. Motivated by these problems, we identified JNK-interacting protein 3 (JIP3) as an important regulator of axonal lysosome transport and maturation. JIP3 knockout mouse neuron primary cultures accumulate lysosomes within focal axonal swellings that resemble the dystrophic axons at amyloid plaques. These swellings contain high levels of amyloid precursor protein processing enzymes (BACE1 and presenilin 2) and are accompanied by elevated Aβ peptide levels. The in vivo importance of the JIP3-dependent regulation of axonal lysosomes was revealed by the worsening of the amyloid plaque pathology arising from JIP3 haploinsufficiency in a mouse model of AD. These results establish the critical role of JIP3-dependent axonal lysosome transport in regulating amyloidogenic amyloid precursor protein processing and support a model wherein Aβ production is amplified by plaque-induced axonal lysosome transport defects. © 2017 Gowrishankar et al.

  2. Distribution and possible function of lysosomal enzymes in the inner ear under normal and pathophysiological conditions.

    Science.gov (United States)

    Schätzle, W

    1976-05-31

    The normal distribution of several lysosomal enzymes was studied in 20 guinea pigs. In the outer hair cells lysosomal enzymes are mainly localized at the apical cell pole, while in inner hair cells the distribution was uniform. Nonlysosomal enzymes like alcaline phosphatase are of predominantly basal localization. The concentration of some lysosomal enzymes like N-acetyl-beta-glucosaminidase was higher in outer than in inner hair cells while others like acid phosphatase, beta-glucuronidase and sulfatase showed a stronger reaction in the inner hair cells. After 10 days of sound overstimulation with 120 dB for 1 h a day, there was an increase of lysosomal enzyme content namely in the outer hair cells. There was no change of non-lysosomal enzymes. Under these conditions there might be a partial destruction of cellular organelles eliminated by lysosomal activity without loss of a total cell. In addition the distribution and possible function of lysosomal enzymes in other labyrinthine tissues was discussed.

  3. 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.

  4. Subversion of a lysosomal pathway regulating neutrophil apoptosis by a major bacterial toxin, pyocyanin.

    Science.gov (United States)

    Prince, Lynne R; Bianchi, Stephen M; Vaughan, Kathryn M; Bewley, Martin A; Marriott, Helen M; Walmsley, Sarah R; Taylor, Graham W; Buttle, David J; Sabroe, Ian; Dockrell, David H; Whyte, Moira K B

    2008-03-01

    Neutrophils undergo rapid constitutive apoptosis that is accelerated following bacterial ingestion as part of effective immunity, but is also accelerated by bacterial exotoxins as a mechanism of immune evasion. The paradigm of pathogen-driven neutrophil apoptosis is exemplified by the Pseudomonas aeruginosa toxic metabolite, pyocyanin. We previously showed pyocyanin dramatically accelerates neutrophil apoptosis both in vitro and in vivo, impairs host defenses, and favors bacterial persistence. In this study, we investigated the mechanisms of pyocyanin-induced neutrophil apoptosis. Pyocyanin induced early lysosomal dysfunction, shown by altered lysosomal pH, within 15 min of exposure. Lysosomal disruption was followed by mitochondrial membrane permeabilization, caspase activation, and destabilization of Mcl-1. Pharmacological inhibitors of a lysosomal protease, cathepsin D (CTSD), abrogated pyocyanin-induced apoptosis, and translocation of CTSD to the cytosol followed pyocyanin treatment and lysosomal disruption. A stable analog of cAMP (dibutyryl cAMP) impeded the translocation of CTSD and prevented the destabilization of Mcl-1 by pyocyanin. Thus, pyocyanin activated a coordinated series of events dependent upon lysosomal dysfunction and protease release, the first description of a bacterial toxin using a lysosomal cell death pathway. This may be a pathological pathway of cell death to which neutrophils are particularly susceptible, and could be therapeutically targeted to limit neutrophil death and preserve host responses.

  5. 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.

  6. 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

  7. Rheb localized on the Golgi membrane activates lysosome-localized mTORC1 at the Golgi-lysosome contact site.

    Science.gov (United States)

    Hao, Feike; Kondo, Kazuhiko; Itoh, Takashi; Ikari, Sumiko; Nada, Shigeyuki; Okada, Masato; Noda, Takeshi

    2018-01-29

    In response to amino acid supply, mTORC1, a master regulator of cell growth, is recruited to the lysosome and activated by the small GTPase Rheb. However, the intracellular localization of Rheb is controversial. In this study, we showed that a significant portion of Rheb is localized on the Golgi but not on the lysosome. GFP-Rheb could activate mTORC1, even when forced to exclusively localize to the Golgi. Likewise, artificial recruitment of mTORC1 to the Golgi allowed its activation. Accordingly, the Golgi was in contact with the lysosome at an newly discovered area of the cell that we term the Golgi-lysosome contact site (GLCS). The number of GLCSs increased in response to amino acid supply, whereas GLCS perturbation suppressed mTORC1 activation. These results suggest that inter-organelle communication between the Golgi and lysosome is important for mTORC1 regulation and the Golgi-localized Rheb may activate mTORC1 at GLCSs. © 2018. Published by The Company of Biologists Ltd.

  8. Percutaneous Transluminal Angioplasty of Peripheral Bypass Stenoses

    International Nuclear Information System (INIS)

    Hoksbergen, Arjan W.J.; Legemate, Dink A.; Reekers, Jim A.; Ubbink, Dirk T.; Jacobs, Michael J.H.M.

    1999-01-01

    Purpose: To assess the success of percutaneous transluminal angioplasty (PTA) in treating peripheral bypass stenoses. Methods: Patients who received a femoropopliteal or femorocrural bypass graft for limb ischemia were included in a duplex surveillance program. If duplex ultrasound revealed a short (<2 cm) severe (peak systolic velocity ratio ≥ 4.5) stenosis, patients were scheduled for arteriography and PTA. Fifty-eight peripheral bypass stenoses in 39 grafts in 37 patients were treated with PTA. The cumulative primary patency of treated stenoses was calculated. Results: During the first year after PTA 31 (53%) treated lesions remained patent, 15 (26%) lesions restenosed at a median interval of 5.0 (range 1-12) months and 4 (7%) bypasses occluded. The cumulative primary patency of 58 treated graft stenoses at 1 year was 60% [95% confidence interval (CI) 46%-74%] and 55% (95% CI 41%-70%) at 2 years. Graft body stenoses showed a better 2-year cumulative primary patency (86%; 95% CI 68%-100%) compared with juxta-anastomotic lesions (45%; 95% CI 29%-62%; p < 0.05). Conclusion: PTA is justifiable as the initial treatment of peripheral bypass stenoses. Nevertheless, the restenosis rate is rather high, especially in juxta-anastomotic lesions. Continuation of duplex surveillance after PTA and timely reintervention is recommended

  9. Lysosome-associated hypertrophic cardiomyopathy (Danon's disease in two siblings

    Directory of Open Access Journals (Sweden)

    I. V. Leontyeva

    2015-01-01

    Full Text Available The paper presents a clinical observation of two siblings with Danon's disease (lysosome-associated cardiomyopathy verified by genetic examination. Heart lesion in Danon's disease bears a phenotypic similarity to the primary forms of hypertrophic cardiomyopathy; in this connection the correct etiology of the disease has remained long unestablished. The presence of laboratory markers as the significantly raised levels of transaminases, creatine phosphokinase, and lactate dehydrogenase was as a guide for suspecting the metabolic origin of the disease. Two siblings with a similar LAMP gene mutation were observed to have a different clinical course: a severer clinical course of cardiomyopathy with extreme myocardial hypertrophy, myocardial electric instability, and mental development retardation in one case and a more favorable course in the other; although a 2-year follow-up also revealed negative changes. For the prevention of sudden cardiac death, a cardioverter defibrulator was implanted and continuous therapy with p-adrenoblockers was performed. The specific feature of the cases was no symptoms of skeletal myopathy, moderate mental retardation only in the elder brother, no evidence of an accessory atrioventricular junction despite the fact that there were ECG manifestations of Wolff-Parkinson-White syndrome

  10. 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.

  11. A TRP Channel Senses Lysosome Neutralization by Pathogens to Trigger Their Expulsion

    Science.gov (United States)

    Miao, Yuxuan; Li, Guojie; Zhang, Xiaoli; Xu, Haoxing; Abraham, Soman N.

    2015-01-01

    SUMMARY Vertebrate cells have evolved elaborate cell-autonomous defense programs to monitor subcellular compartments for infection and to evoke counter-responses. These programs are activated by pathogen-associated pattern molecules and by various strategies intracellular pathogens employ to alter cellular microenvironments. Here, we show that when uropathogenic E. coli (UPEC) infect bladder epithelial cells (BECs), they are targeted by autophagy but avoid degradation because of their capacity to neutralize lysosomal pH. This change is detected by mucolipin TRP channel 3 (TRPML3), a transient receptor potential cation channel localized to lysosomes. TRPML3 activation then spontaneously initiates lysosome exocytosis, resulting in expulsion of exosome-encased bacteria. These studies reveal a cellular default system for lysosome homeostasis that has been co-opted by the autonomous defense program to clear recalcitrant pathogens. PMID:26027738

  12. Lipid Involvement in Neurodegenerative Diseases of the Motor System: Insights from Lysosomal Storage Diseases.

    Science.gov (United States)

    Dodge, James C

    2017-01-01

    Lysosomal storage diseases (LSDs) are a heterogeneous group of rare inherited metabolic diseases that are frequently triggered by the accumulation of lipids inside organelles of the endosomal-autophagic-lysosomal system (EALS). There is now a growing realization that disrupted lysosomal homeostasis (i.e., lysosomal cacostasis) also contributes to more common neurodegenerative disorders such as Parkinson disease (PD). Lipid deposition within the EALS may also participate in the pathogenesis of some additional neurodegenerative diseases of the motor system. Here, I will highlight the lipid abnormalities and clinical manifestations that are common to LSDs and several diseases of the motor system, including amyotrophic lateral sclerosis (ALS), atypical forms of spinal muscular atrophy, Charcot-Marie-Tooth disease (CMT), hereditary spastic paraplegia (HSP), multiple system atrophy (MSA), PD and spinocerebellar ataxia (SCA). Elucidating the underlying basis of intracellular lipid mislocalization as well as its consequences in each of these disorders will likely provide innovative targets for therapeutic research.

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

    NARCIS (Netherlands)

    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.

    2016-01-01

    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

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  15. A NIR phosphorescent osmium(ii) complex as a lysosome tracking reagent and photodynamic therapeutic agent.

    Science.gov (United States)

    Zhang, Pingyu; Wang, Yi; Qiu, Kangqiang; Zhao, Zhiqian; Hu, Rentao; He, Chuanxin; Zhang, Qianling; Chao, Hui

    2017-11-14

    A novel near infrared (NIR) phosphorescent osmium complex (Os1) was developed for lysosome tracking and photodynamic therapy. Owing to its NIR photophysical properties, cellular imaging ability and phototoxicity, it has advantages over its ruthenium analogue (Ru1).

  16. Doppler spectral characteristics of infrainguinal vein bypasses

    DEFF Research Database (Denmark)

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

    1993-01-01

    of arteriovenous fistulas the initially antegrade diastolic velocity was replaced by a retrograde flow within 3 months, whereas a forward flow in diastole was sustained in grafts with patent fistulas. Abnormal Duplex findings in 31 patients led to angiography and revision in 13 cases. Four revised grafts failed......, while nine remained patent at follow-up 1-12 months later. Ten (56%) of 18 non-revised bypasses with abnormal Duplex findings failed within 9 months compared to 1 (1%) of 76 bypasses with a normal velocity profile (p ... valuable information concerning haemodynamics of infrainguinal vein bypasses and identifies grafts at risk of thrombosis. Inclusion of low resistance index (detection of stenoses appears to improve the sensitivity of Duplex scanning....

  17. Neuronal-Targeted TFEB Accelerates Lysosomal Degradation of APP, Reducing Aβ Generation and Amyloid Plaque Pathogenesis.

    Science.gov (United States)

    Xiao, Qingli; Yan, Ping; Ma, Xiucui; Liu, Haiyan; Perez, Ronaldo; Zhu, Alec; Gonzales, Ernesto; Tripoli, Danielle L; Czerniewski, Leah; Ballabio, Andrea; Cirrito, John R; Diwan, Abhinav; Lee, Jin-Moo

    2015-09-02

    In AD, an imbalance between Aβ production and removal drives elevated brain Aβ levels and eventual amyloid plaque deposition. APP undergoes nonamyloidogenic processing via α-cleavage at the plasma membrane, amyloidogenic β- and γ-cleavage within endosomes to generate Aβ, or lysosomal degradation in neurons. Considering multiple reports implicating impaired lysosome function as a driver of increased amyloidogenic processing of APP, we explored the efficacy of targeting transcription factor EB (TFEB), a master regulator of lysosomal pathways, to reduce Aβ levels. CMV promoter-driven TFEB, transduced via stereotactic hippocampal injections of adeno-associated virus particles in APP/PS1 mice, localized primarily to neuronal nuclei and upregulated lysosome biogenesis. This resulted in reduction of APP protein, the α and β C-terminal APP fragments (CTFs), and in the steady-state Aβ levels in the brain interstitial fluid. In aged mice, total Aβ levels and amyloid plaque load were selectively reduced in the TFEB-transduced hippocampi. TFEB transfection in N2a cells stably expressing APP695, stimulated lysosome biogenesis, reduced steady-state levels of APP and α- and β-CTFs, and attenuated Aβ generation by accelerating flux through the endosome-lysosome pathway. Cycloheximide chase assays revealed a shortening of APP half-life with exogenous TFEB expression, which was prevented by concomitant inhibition of lysosomal acidification. These data indicate that TFEB enhances flux through lysosomal degradative pathways to induce APP degradation and reduce Aβ generation. Activation of TFEB in neurons is an effective strategy to attenuate Aβ generation and attenuate amyloid plaque deposition in AD. A key driver for AD pathogenesis is the net balance between production and clearance of Aβ, the major component of amyloid plaques. Here we demonstrate that lysosomal degradation of holo-APP influences Aβ production by limiting the availability of APP for amyloidogenic

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

  20. Bearing/Bypass Material-Testing System

    Science.gov (United States)

    Crews, John H., Jr.

    1988-01-01

    System developed to test specimens in compression as well as tension while maintaining constant bearing/bypass ration. Test specimen with centrally located hole is clamped between two bearing-guide plates using one bolt. Bearing-guide plates then secured to two bearing-load cells. Test specimen independently loaded at both ends, using two separate control systems identified as applied and bypass. If two end loads unequal, difference between them reacted as bolt-bearing load on specimen. Throughout test, two control systems synchronized by common input signal (increasing voltage). As result, loads remain proportional as they increase.

  1. Uptake and degradation of cytoplasmic RNA by lysosomes in the perfused rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Heydrick, S.J.; Lardeux, B.; Mortimore, G.E.

    1987-05-01

    The release of (/sup 14/C)cytidine has been shown previously to be a valid marker for RNA degradation in rat hepatocytes. The breakdown of RNA measured with this marker in perfused livers prelabeled in vivo with (6-/sup 14/C)orotic acid was found to be regulated acutely by perfusate amino acids over a wide range, from 0.29 to 3.48%/h. This regulation paralleled that of lysosomal proteolysis. Chloroquine inhibited RNA degradation 60-70%. In subsequent cell fractionation studies labelled cytidine was released; the distribution of this release paralleled that of a lysosomal marker enzyme. The release plateaued after two hours, defining a distinct lysosomal pool of RNA. The lysosomal location of the RNA pool was confirmed in experiments where a 22% increase in the apparent pool size was obtained by lowering the homogenate pH from 7.0 to 5.5. The pool size correlated linearly with the rate of RNA degradation measured during perfusion, giving a turnover constant in reasonable agreement with values reported for autophagy. These results indicate that cytoplasmic RNA degradation occurs primarily in the lysosome and is regulated under these conditions by the amino acid control of lysosomal sequestration of cytoplasm.

  2. Variable volume combustor with an air bypass system

    Science.gov (United States)

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

    2017-02-07

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

  3. The LAMP-like protein p67 plays an essential role in the lysosome of African trypanosomes.

    Science.gov (United States)

    Peck, Ronald F; Shiflett, April M; Schwartz, Kevin J; McCann, Amanda; Hajduk, Stephen L; Bangs, James D

    2008-05-01

    RNAi knockdown was employed to study the function of p67, a lysosome-associated membrane protein (LAMP)-like type I transmembrane lysosomal glycoprotein in African trypanosomes. Conditional induction of p67 dsRNA resulted in specific approximately 90% reductions in de novo p67 synthesis in both mammalian bloodstream and procyclic insect-stage parasites. Bloodstream cell growth was severely retarded with extensive death after > 24 h of induction. Biosynthetic trafficking of residual p67, and of the soluble lysosomal protease trypanopain, were unimpaired. Endocytosis of tomato lectin, a surrogate receptor-mediated cargo, was only mildly impaired (approximately 20%), but proper lysosomal targeting was unaffected. p67 ablation had dramatic effects on lysosomal morphology with gross enlargement (four- to fivefold) and internal membrane profiles reminiscent of autophagic vacuoles. Ablation of p67 expression rendered bloodstream trypanosomes refractory to lysis by human trypanolytic factor (TLF), a lysosomally activated host innate immune mediator. Similar effects on lysosomal morphology and TLF sensitivity were also obtained by two pharmacological agents that neutralize lysosomal pH--chloroquine and bafilomycin A1. Surprisingly, however, lysosomal pH was not affected in ablated cells suggesting that other physiological alterations must account for increased resistance to TLF. These results indicate p67 plays an essential role in maintenance of normal lysosomal structure and physiology in bloodstream-stage African trypanosomes.

  4. A fluorescence resonance energy transfer-based approach for investigating late endosome–lysosome retrograde fusion events

    Science.gov (United States)

    Kaufmann, A.M.; Goldman, S.D.B.; Krise, J.P.

    2009-01-01

    Traditionally, lysosomes have been considered to be a terminal endocytic compartment. Recent studies suggest that lysosomes are quite dynamic, being able to fuse with other late endocytic compartments as well as with the plasma membrane. Here we describe a quantitative fluorescence energy transfer (FRET)-based method for assessing rates of retrograde fusion between terminal lysosomes and late endosomes in living cells. Late endosomes were specifically labeled with 800-nm latex beads that were conjugated with streptavidin and Alexa Fluor 555 (FRET donor). Terminal lysosomes were specifically labeled with 10,000-MW dextran polymers conjugated with biotin and Alexa Fluor 647 (FRET acceptor). Following late endosome–lysosome fusion, the strong binding affinity between streptavidin and biotin brought the donor and acceptor fluorophore molecules into close proximity, thereby facilitating the appearance of a FRET emission signal. Because apparent size restrictions in the endocytic pathway do not permit endocytosed latex beads from reaching terminal lysosomes in an anterograde fashion, the appearance of the FRET signal is consistent with retrograde transport of lysosomal cargo back to late endosomes. We assessed the efficiency of this transport step in fibroblasts affected by different lysosome storage disorders—Niemann–Pick type C, mucolipidosis type IV, and Sandhoff’s disease, all of which have a similar lysosomal lipid accumulation phenotype. We report here, for the first time, that these disorders can be distinguished by their rate of transfer of lysosome cargos to late endosomes, and we discuss the implications of these findings for developing new therapeutic strategies. PMID:19109922

  5. A fluorescence resonance energy transfer-based approach for investigating late endosome-lysosome retrograde fusion events.

    Science.gov (United States)

    Kaufmann, A M; Goldman, S D B; Krise, J P

    2009-03-01

    Traditionally, lysosomes have been considered to be a terminal endocytic compartment. Recent studies suggest that lysosomes are quite dynamic, being able to fuse with other late endocytic compartments as well as with the plasma membrane. Here we describe a quantitative fluorescence energy transfer (FRET)-based method for assessing rates of retrograde fusion between terminal lysosomes and late endosomes in living cells. Late endosomes were specifically labeled with 800-nm latex beads that were conjugated with streptavidin and Alexa Fluor 555 (FRET donor). Terminal lysosomes were specifically labeled with 10,000-MW dextran polymers conjugated with biotin and Alexa Fluor 647 (FRET acceptor). Following late endosome-lysosome fusion, the strong binding affinity between streptavidin and biotin brought the donor and acceptor fluorophore molecules into close proximity, thereby facilitating the appearance of a FRET emission signal. Because apparent size restrictions in the endocytic pathway do not permit endocytosed latex beads from reaching terminal lysosomes in an anterograde fashion, the appearance of the FRET signal is consistent with retrograde transport of lysosomal cargo back to late endosomes. We assessed the efficiency of this transport step in fibroblasts affected by different lysosome storage disorders-Niemann-Pick type C, mucolipidosis type IV, and Sandhoff's disease, all of which have a similar lysosomal lipid accumulation phenotype. We report here, for the first time, that these disorders can be distinguished by their rate of transfer of lysosome cargos to late endosomes, and we discuss the implications of these findings for developing new therapeutic strategies.

  6. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to flow...

  7. 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

  8. 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 or...

  9. 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. 870.4250 Section 870.4250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller...

  10. 21 CFR 870.4300 - Cardiopulmonary bypass gas control unit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass gas control unit. 870.4300... bypass gas control unit. (a) Identification. A cardiopulmonary bypass gas control unit is a device used to control and measure the flow of gas into the oxygenator. The device is calibrated for a specific...

  11. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pulsatile flow generator... Cardiopulmonary bypass pulsatile flow generator. (a) Identification. A cardiopulmonary bypass pulsatile flow generator is an electrically and pneumatically operated device used to create pulsatile blood flow. The...

  12. 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 assists...

  13. 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

  14. Reconstitution of lysosomal ion channels into artificial membranes.

    Science.gov (United States)

    Venturi, Elisa; Sitsapesan, Rebecca

    2015-01-01

    Ion channels that are located on intracellular organelles have always posed challenges for biophysicists seeking to measure their ion conduction, selectivity, and gating kinetics. Unlike cell surface ion channels, intracellular ion channels cannot be accessed for biophysical single-channel recordings using the patch-clamp technique while remaining in a physiological setting. Disruption of the cell is always necessary and hence experiments inevitably have a certain "artificial" nature about them. This drawback is turned to considerable advantage if the internal membranes containing the channels of interest can be isolated or if the channels can be purified because they can then be incorporated into artificial membranes of controlled composition. This approach guarantees a tight but flexible control over the biophysical and biochemical environment of the ion channel molecules. This includes the lipid composition of the membrane and the ionic solutions on both sides of the channel, thus allowing the conductance properties of the channel to be accurately measured. Since the influence of multiple unknown regulators of channel function (that could be present within the physiological membrane or in cytosolic, or intraorganelle compartments) is removed, the identification and characterization of physiological and pharmacological regulators that directly affect channel gating can also be achieved. This cannot be performed in a cellular environment. These techniques have typically been used to study the properties of channels located on endoplasmic/sarcoplasmic reticulum (ER/SR) membranes but in this chapter we describe how the techniques are also suited for ion channels of the acidic lysosomal and endolysosomal Ca(2+) stores. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. A Survey of Cache Bypassing Techniques

    Directory of Open Access Journals (Sweden)

    Sparsh Mittal

    2016-04-01

    Full Text Available With increasing core-count, the cache demand of modern processors has also increased. However, due to strict area/power budgets and presence of poor data-locality workloads, blindly scaling cache capacity is both infeasible and ineffective. Cache bypassing is a promising technique to increase effective cache capacity without incurring power/area costs of a larger sized cache. However, injudicious use of cache bypassing can lead to bandwidth congestion and increased miss-rate and hence, intelligent techniques are required to harness its full potential. This paper presents a survey of cache bypassing techniques for CPUs, GPUs and CPU-GPU heterogeneous systems, and for caches designed with SRAM, non-volatile memory (NVM and die-stacked DRAM. By classifying the techniques based on key parameters, it underscores their differences and similarities. We hope that this paper will provide insights into cache bypassing techniques and associated tradeoffs and will be useful for computer architects, system designers and other researchers.

  16. 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...... analgesic treatment in LRYGB surgery....

  17. Planetary science: Bypassing the habitable zone

    Science.gov (United States)

    Ingersoll, Andrew P.

    2017-08-01

    In our own solar system, Venus is too hot, Mars is too cold and Earth is just right. Simulations show that making an icy planet habitable is not as simple as melting its ice: many icy bodies swing from too cold to too hot, bypassing just right.

  18. 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

  19. 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.

  20. Ethambutol-induced toxicity is mediated by zinc and lysosomal membrane permeabilization in cultured retinal cells

    International Nuclear Information System (INIS)

    Chung, Hyewon; Yoon, Young Hee; Hwang, Jung Jin; Cho, Kyung Sook; Koh, Jae Young; Kim, June-Gone

    2009-01-01

    Ethambutol, an efficacious antituberculosis agent, can cause irreversible visual loss in a small but significant fraction of patients. However, the mechanism of ocular toxicity remains to be established. We previously reported that ethambutol caused severe vacuole formation in cultured retinal cells, and that the addition of zinc along with ethambutol aggravated vacuole formation whereas addition of the cell-permeable zinc chelator, N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), reduced vacuole formation. To investigate the origin of vacuoles and to obtain an understanding of drug toxicity, we used cultured primary retinal cells from newborn Sprague-Dawley rats and imaged ethambutol-treated cells stained with FluoZin-3, zinc-specific fluorescent dye, under a confocal microscope. Almost all ethambutol-induced vacuoles contained high levels of labile zinc. Double staining with LysoTracker or MitoTracker revealed that almost all zinc-containing vacuoles were lysosomes and not mitochondria. Intracellular zinc chelation with TPEN markedly blocked both vacuole formation and zinc accumulation in the vacuole. Immunocytochemistry with antibodies to lysosomal-associated membrane protein-2 (LAMP-2) and cathepsin D, an acid lysosomal hydrolase, disclosed lysosomal activation after exposure to ethambutol. Immunoblotting after 12 h exposure to ethambutol showed that cathepsin D was released into the cytosol. In addition, cathepsin inhibitors attenuated retinal cell toxicity induced by ethambutol. This is consistent with characteristics of lysosomal membrane permeabilization (LMP). TPEN also inhibited both lysosomal activation and LMP. Thus, accumulation of zinc in lysosomes, and eventual LMP, may be a key mechanism of ethambutol-induced retinal cell death

  1. Dictyostelium LvsB Mutants Model the Lysosomal Defects Associated with Chediak-Higashi Syndrome

    Science.gov (United States)

    Harris, Edward; Wang, Ning; Wu, Wei-l; Weatherford, Alisha; De Lozanne, Arturo; Cardelli, James

    2002-01-01

    Chediak-Higashi syndrome is a genetic disorder caused by mutations in a gene encoding a protein named LYST in humans (“lysosomal trafficking regulator”) or Beige in mice. A prominent feature of this disease is the accumulation of enlarged lysosome-related granules in a variety of cells. The genome of Dictyostelium discoideum contains six genes encoding proteins that are related to LYST/Beige in amino acid sequence, and disruption of one of these genes, lvsA (large volume sphere), results in profound defects in cytokinesis. To better understand the function of this family of proteins in membrane trafficking, we have analyzed mutants disrupted in lvsA, lvsB, lvsC, lvsD, lvsE, and lvsF. Of all these, only lvsA and lvsB mutants displayed interesting phenotypes in our assays. lvsA-null cells exhibited defects in phagocytosis and contained abnormal looking contractile vacuole membranes. Loss of LvsB, the Dictyostelium protein most similar to LYST/Beige, resulted in the formation of enlarged vesicles that by multiple criteria appeared to be acidic lysosomes. The rates of endocytosis, phagocytosis, and fluid phase exocytosis were normal in lvsB-null cells. Also, the rates of processing and the efficiency of targeting of lysosomal α-mannosidase were normal, although lvsB mutants inefficiently retained α-mannosidase, as well as two other lysosomal cysteine proteinases. Finally, results of pulse-chase experiments indicated that an increase in fusion rates accounted for the enlarged lysosomes in lvsB-null cells, suggesting that LvsB acts as a negative regulator of fusion. Our results support the notion that LvsB/LYST/Beige function in a similar manner to regulate lysosome biogenesis. PMID:11854420

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

    International Nuclear Information System (INIS)

    Odessey, R.

    1986-01-01

    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 3 H-phenylalanine or 3 H-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

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

    Directory of Open Access Journals (Sweden)

    Virginie Hubert

    2016-10-01

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

  4. 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.

  5. A lysosomal switch triggers proteostasis renewal in the immortal C. elegans germ lineage.

    Science.gov (United States)

    Bohnert, K Adam; Kenyon, Cynthia

    2017-11-30

    Although individuals age and die with time, an animal species can continue indefinitely, because of its immortal germ-cell lineage. How the germline avoids transmitting damage from one generation to the next remains a fundamental question in biology. Here we identify a lysosomal switch that enhances germline proteostasis before fertilization. We find that Caenorhabditis elegans oocytes whose maturation is arrested by the absence of sperm exhibit hallmarks of proteostasis collapse, including protein aggregation. Remarkably, sperm-secreted hormones re-establish oocyte proteostasis once fertilization becomes imminent. Key to this restoration is activation of the vacuolar H + -ATPase (V-ATPase), a proton pump that acidifies lysosomes. Sperm stimulate V-ATPase activity in oocytes by signalling the degradation of GLD-1, a translational repressor that blocks V-ATPase synthesis. Activated lysosomes, in turn, promote a metabolic shift that mobilizes protein aggregates for degradation, and reset proteostasis by enveloping and clearing the aggregates. Lysosome acidification also occurs during Xenopus oocyte maturation; thus, a lysosomal switch that enhances oocyte proteostasis in anticipation of fertilization may be conserved in other species.

  6. Lysosomal cross-correction by hematopoietic stem cell-derived macrophages via tunneling nanotubes

    Science.gov (United States)

    Naphade, Swati; Sharma, Jay; Chevronnay, Héloïse P. Gaide; Shook, Michael A.; Yeagy, Brian A.; Rocca, Celine J.; Ur, Sarah N.; Lau, Athena J.; Courtoy, Pierre J.; Cherqui, Stephanie

    2014-01-01

    Despite controversies on the potential of hematopoietic stem cells (HSCs) to promote tissue repair, we previously showed that HSC transplantation could correct cystinosis, a multi-systemic lysosomal storage disease, caused by a defective lysosomal membrane cystine transporter, cystinosin (CTNS). Addressing the cellular mechanisms, we here report vesicular cross-correction after HSC differentiation into macrophages. Upon co-culture with cystinotic fibroblasts, macrophages produced tunneling nanotubes (TNTs) allowing transfer of cystinosin-bearing lysosomes into Ctns-deficient cells, which exploited the same route to retrogradely transfer cystine-loaded lysosomes to macrophages, providing a bidirectional correction mechanism. TNT formation was enhanced by contact with diseased cells. In vivo, HSCs grafted to cystinotic kidneys also generated nanotubular extensions resembling invadopodia that crossed the dense basement membranes and delivered cystinosin into diseased proximal tubular cells. This is the first report of correction of a genetic lysosomal defect by bidirectional vesicular exchange via TNTs and suggests broader potential for HSC transplantation for other disorders due to defective vesicular proteins. PMID:25186209

  7. Alterations in lysosomal and proteasomal markers in Parkinson's disease: relationship to alpha-synuclein inclusions.

    Science.gov (United States)

    Chu, Yaping; Dodiya, Hemraj; Aebischer, Patrick; Olanow, C Warren; Kordower, Jeffrey H

    2009-09-01

    We explored the relationship between ubiquitin proteasome system (UPS) and lysosomal markers and the formation of alpha-synuclein (alpha-syn) inclusions in nigral neurons in Parkinson disease (PD). Lysosome Associated Membrane Protein 1(LAMP1), Cathepsin D (CatD), and Heat Shock Protein73 (HSP73) immunoreactivity were significantly decreased within PD nigral neurons when compared to age-matched controls. This decrease was significantly greater in nigral neurons that contained alpha-syn inclusions. Immunoreactivity for 20S proteasome was similarly reduced in PD nigral neurons, but only in cells that contained inclusions. In aged control brains, there is staining for alpha-syn protein, but it is non-aggregated and there is no difference in LAMP1, CatD, HSP73 or 20S proteasome immunoreactivity between alpha-syn positive or negative neuromelanin-laden nigral neurons. Targeting over-expression of mutant human alpha-syn in the rat substantia nigra using viral vectors revealed that lysosomal and proteasomal markers were significantly decreased in the neurons that displayed alpha-syn-ir inclusions. These findings suggest that alpha-syn aggregation is a key feature associated with decline of proteasome and lysosome and support the hypothesis that cell degeneration in PD involves proteosomal and lysosomal dysfunction, impaired protein clearance, and protein accumulation and aggregation leading to cell death.

  8. Waking up the gastric bypass patient.

    Science.gov (United States)

    Walter, D A

    1997-08-01

    Waking up the gastric bypass patient in the post-anesthesia care unit (PACU) is a continual challenge. From January 1992 to November 1996, 961 gastric bypasses (GBP) have been performed at Columbia St Mark's Hospital. Of the 961 patients, 957 came to the PACU. Four patients went directly to ICU because of respiratory status requiring mechanical ventilation. There have been no deaths and no respiratory arrests in PACU. Continuous bedside monitoring of the patient's respiratory status coupled with pain management contributed to positive care of the GBP patient. Methods of care for the GBP patient include the use of O2 masks and cannulas, coughing and deep breathing, administering i.v. narcotics until patient controlled analgesia pumps are initiated, encouragement and emotional support, ongoing assessment of patients' status, and treating problems/needs appropriately.

  9. Hypothenar hammer syndrome and basilic bypass.

    Science.gov (United States)

    Chander, R K; Phair, J; Oza, P; Patel, M; Balar, N

    2014-12-01

    We report a case of hypothenar hammer syndrome. The case presents necessary diagnostic measures and discusses the etiology of this syndrome. Additionally, the case reviews treatments, which culminated in the eventual use of ulnar artery bypass with autogenous basilica vein to treat and resolve the ischemic fingers of the patient. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  10. Interposition vein cuff in infrainguinal prosthetic bypasses.

    Science.gov (United States)

    D'Andrea, V; Biancari, F; Catania, A; Di Matteo, F M; Sorrenti, S; Spyrou, M; Dibra, A; Foti, N; Ortensi, A

    1999-01-01

    The Authors describe the interposition vein cuff technique as an adjuvant method to infrainguinal prosthetic bypass grafts. The haemodynamic, mechanical and humoral factors thought to be involved in the beneficial effects of the vein cuff are herein discussed. The results of the main series suggest the use of this method particularly in patients without any available autologous vein conduit requiring a below-knee popliteal or crural reconstruction.

  11. 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

    . Combined with stereologic techniques, we examined components of the ELS in human sporadic Creutzfeldt-Jakob disease brains. We immunostained for the early endosomal marker Rab5 and lysosomal enzymes cathepsin D and B. We determined neuron-specific changes in their expression and correlated......-immunoreactive lysosomes. The intraneuronal distribution of cathepsin D and B diverges between Purkinje cells and frontal cortical neurons in sporadic Creutzfeldt-Jakob disease brains. We demonstrated focal intra- and perineuronal colocalization of cathepsin D and PrP. Our results indicate that effects in the ELS......The endosomal-lysosomal system (ELS) has been suggested to play a role in the pathogenesis of prion diseases. The purpose of this study was to examine how experimental observations can be translated to human neuropathology and whether alterations of the ELS relate to neuropathologic changes...

  12. Prevention of lysosomal storage in Tay-Sachs mice treated with N-butyldeoxynojirimycin.

    Science.gov (United States)

    Platt, F M; Neises, G R; Reinkensmeier, G; Townsend, M J; Perry, V H; Proia, R L; Winchester, B; Dwek, R A; Butters, T D

    1997-04-18

    The glycosphingolipid (GSL) lysosomal storage diseases result from the inheritance of defects in the genes encoding the enzymes required for catabolism of GSLs within lysosomes. A strategy for the treatment of these diseases, based on an inhibitor of GSL biosynthesis N-butyldeoxynojirimycin, was evaluated in a mouse model of Tay-Sachs disease. When Tay-Sachs mice were treated with N-butyldeoxynojirimycin, the accumulation of GM2 in the brain was prevented, with the number of storage neurons and the quantity of ganglioside stored per cell markedly reduced. Thus, limiting the biosynthesis of the substrate (GM2) for the defective enzyme (beta-hexosaminidase A) prevents GSL accumulation and the neuropathology associated with its lysosomal storage.

  13. 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

    fibroblasts. Blocking lysosomal cysteine proteases with the inhibitor E64d resulted in strong accumulation of collagen IV in lysosomes in wild-type cells, but only very weak intracellular fluorescence accumulation in uPARAP/endo180-deficient fibroblasts. We conclude that uPARAP/endo180 is critical......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...

  14. Cell Entry of Porcine Epidemic Diarrhea Coronavirus Is Activated by Lysosomal Proteases*

    Science.gov (United States)

    Liu, Chang; Ma, Yuanmei; Yang, Yang; Zheng, Yuan; Shang, Jian; Zhou, Yusen; Jiang, Shibo; Du, Lanying; Li, Jianrong; Li, Fang

    2016-01-01

    Porcine epidemic diarrhea coronavirus (PEDV) is currently devastating the United States pork industry by causing an 80–100% fatality rate in infected piglets. Coronavirus spike proteins mediate virus entry into cells, a process that requires the spike proteins to be proteolytically activated. It has been a conundrum which proteases activate PEDV entry. Here we systematically investigated the roles of different proteases in PEDV entry using pseudovirus entry, biochemical, and live virus infection assays. We found that the PEDV spike is activated by lysosomal cysteine proteases but not proprotein convertases or cell surface serine proteases. Extracellular trypsin activates PEDV entry when lysosomal cysteine proteases are inhibited. We further pinpointed cathepsin L and cathepsin B as the lysosomal cysteine proteases that activate the PEDV spike. These results advance our understanding of the molecular mechanism for PEDV entry and identify potential antiviral targets for curbing the spread of PEDV. PMID:27729455

  15. 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

    study was to investigate the presence of lysosomes in astrocytic brain tumors focussing also on the therapy resistant tumor stem cells. Expression of the lysosomal marker LAMP-1 (lysosomal-associated membrane protein-1) was investigated by immunohistochemistry in 112 formalin fixed paraffin embedded...... astrocytomas and compared with tumor grade and overall patient survival. Moreover, double immunofluorescence stainings were performed with LAMP-1 and the astrocytic marker GFAP and the putative stem cell marker CD133 on ten glioblastomas. Most tumors expressed the LAMP-1 protein in the cytoplasm of the tumor...... cells, while the blood vessels were positive in all tumors. The percentage of LAMP-1 positive tumor cells and staining intensities increased with tumor grade but variations in tumors of the same grade were also found. No association was found between LAMP-1 expression and patient overall survival...

  16. [Hemorheological changes during mammary coronary bypass grafting].

    Science.gov (United States)

    Morozov, Iu A; Roĭtman, E V; Charnaia, M A

    2004-01-01

    Hemorheological studies were performed in 44 patients subjected to mammary coronary bypass surgery during induction of anesthesia, at initiation of cardiopulmonary bypass, at the end of operation, on the 1(st) and 2(nd) or 3(rd) postoperative day. Methods included determination of whole blood and plasma viscosity with estimation of suspension stability and calculation of Caisson viscosity and fluidity limit. Rigidometry was used for assessment times of linear (T(1)) and three dimensional (T(2)) aggregates formation, final aggregates dimensions, total hydrodynamic strength of aggregates (beta), index of strength of especially large aggregates. Indexes of aggregation and deformation of erythrocytes were also calculated. Cardiopulmonary bypass was associated with lengthening of T(1) and shortening of T(2), increase of aggregates dimension and their hydrodynamic strength beta and lowering deformability of erythrocytes. By the end of operation increase of difference between Caisson and asymptotic viscosity was noted. Postoperative period was characterized by improvement of deformability of erythrocytes, prolongation of T(2), increases of aggregates dimension, their hydrodynamic strength beta, and fluidity limit. Thus measures of intensive therapy should be directed at correction of disturbances of rheological properties of blood with consideration of their changes specific for cardiosurgical patients.

  17. LYSOSOMAL AND ULTRASTRUCTURAL CHANGES IN HUMAN "TOXIC" NEUTROPHILS DURING BACTERIAL INFECTION

    Science.gov (United States)

    McCall, Charles E.; Katayama, Isao; Cotran, Ramzi S.; Finland, Maxwell

    1969-01-01

    "Toxic" neutrophils from humans with severe bacterial infections, identified by the presence of Döhle bodies, "toxic" granules, and vacuoles were shown to differ from normal neutrophils both in ultrastructure and in lysosome activity. Döhle bodies were identified as lamellar aggregates of rough endoplasmic reticulum. Toxic granules corresponded to the azurophilic granules usually identified by Romanowsky stains only in neutrophil precursors. By electron microscopy such granules were large, electron-dense, and peroxidase positive; they could usually be distinguished from the smaller, less dense, "specific" granules also present in control neutrophils, but in the latter they became visible by light microscopy only after prolonged staining or following fixation with glutaraldehyde. These observations suggest that toxic granules represent an abnormal staining reaction of the large dense granules in the toxic cells, and not phagocytized material, newly formed abnormal granules or autophagic bodies. Alkaline phosphatase activity was significantly greater in toxic neutrophils than in normal ones; 80% of the activity of both was located in the lysosome fraction. Beta glucuronidase was normal. Total acid phosphatase was normal, but the percentage located in the nonlysosome fraction of toxic neutrophils was increased, suggesting that lysosomes were "labilized." Formation of neutral red vacuoles in supravitally stained preparations, an index of lysosome activity, occurred more rapidly in toxic neutrophils. This reaction paralleled degranulation and the formation of clear vacuoles in unstained wet mounts and could be blocked by colchicine, a lysosome stabilizer, or enhanced by procedures which activate lysosomes. "Autophagic" vacuoles were observed by electron microscopy in some toxic neutrophils. These observations are discussed in relation to the concept that the "toxic" neutrophils in severe bacterial infection reflect cellular immaturity and/or stimulation or

  18. Enhancing astrocytic lysosome biogenesis facilitates Aβ clearance and attenuates amyloid plaque pathogenesis.

    Science.gov (United States)

    Xiao, Qingli; Yan, Ping; Ma, Xiucui; Liu, Haiyan; Perez, Ronaldo; Zhu, Alec; Gonzales, Ernesto; Burchett, Jack M; Schuler, Dorothy R; Cirrito, John R; Diwan, Abhinav; Lee, Jin-Moo

    2014-07-16

    In sporadic Alzheimer's disease (AD), impaired Aβ removal contributes to elevated extracellular Aβ levels that drive amyloid plaque pathogenesis. Extracellular proteolysis, export across the blood-brain barrier, and cellular uptake facilitate physiologic Aβ clearance. Astrocytes can take up and degrade Aβ, but it remains unclear whether this function is insufficient in AD or can be enhanced to accelerate Aβ removal. Additionally, age-related dysfunction of lysosomes, the major degradative organelles wherein Aβ localizes after uptake, has been implicated in amyloid plaque pathogenesis. We tested the hypothesis that enhancing lysosomal function in astrocytes with transcription factor EB (TFEB), a master regulator of lysosome biogenesis, would promote Aβ uptake and catabolism and attenuate plaque pathogenesis. Exogenous TFEB localized to the nucleus with transcriptional induction of lysosomal biogenesis and function in vitro. This resulted in significantly accelerated uptake of exogenously applied Aβ42, with increased localization to and degradation within lysosomes in C17.2 cells and primary astrocytes, indicating that TFEB is sufficient to coordinately enhance uptake, trafficking, and degradation of Aβ. Stereotactic injection of adeno-associated viral particles carrying TFEB driven by a glial fibrillary acidic protein promoter was used to achieve astrocyte-specific expression in the hippocampus of APP/PS1 transgenic mice. Exogenous TFEB localized to astrocyte nuclei and enhanced lysosome function, resulting in reduced Aβ levels and shortened half-life in the brain interstitial fluid and reduced amyloid plaque load in the hippocampus compared with control virus-injected mice. Therefore, activation of TFEB in astrocytes is an effective strategy to restore adequate Aβ removal and counter amyloid plaque pathogenesis in AD. Copyright © 2014 the authors 0270-6474/14/349607-14$15.00/0.

  19. ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

    Science.gov (United States)

    Kessel, David H.; Price, Michael; Reiners, Jr., John J.

    2012-01-01

    Photodynamic therapy (PDT) involves photosensitizing agents that, in the presence of oxygen and light, initiate formation of cytotoxic reactive oxygen species (ROS). PDT commonly induces both apoptosis and autophagy. Previous studies with murine hepatoma 1c1c7 cells indicated that loss of autophagy-related protein 7 (ATG7) inhibited autophagy and enhanced the cytotoxicity of photosensitizers that mediate photodamage to mitochondria or the endoplasmic reticulum. In this study, we examined two photosensitizing agents that target lysosomes: the chlorin NPe6 and the palladium bacteriopheophorbide WST11. Irradiation of wild-type 1c1c7 cultures loaded with either photosensitizer induced apoptosis and autophagy, with a blockage of autophagic flux. An ATG7- or ATG5-deficiency suppressed the induction of autophagy in PDT protocols using either photosensitizer. Whereas ATG5-deficient cells were quantitatively similar to wild-type cultures in their response to NPe6 and WST11 PDT, an ATG7-deficiency suppressed the apoptotic response (as monitored by analyses of chromatin condensation and procaspase-3/7 activation) and increased the LD50 light dose by > 5-fold (as monitored by colony-forming assays). An ATG7-deficiency did not prevent immediate lysosomal photodamage, as indicated by loss of the lysosomal pH gradient. However, unlike wild-type and ATG5-deficient cells, the lysosomes of ATG7-deficient cells recovered this gradient within 4 h of irradiation, and never underwent permeabilization (monitored as release of endocytosed 10-kDa dextran polymers). We propose that the efficacy of lysosomal photosensitizers is in part due to both promotion of autophagic stress and suppression of autophagic prosurvival functions. In addition, an effect of ATG7 unrelated to autophagy appears to modulate lysosomal photodamage. PMID:22889762

  20. Excessive burden of lysosomal storage disorder gene variants in Parkinson's disease.

    Science.gov (United States)

    Robak, Laurie A; Jansen, Iris E; van Rooij, Jeroen; Uitterlinden, André G; Kraaij, Robert; Jankovic, Joseph; Heutink, Peter; Shulman, Joshua M

    2017-12-01

    Mutations in the glucocerebrosidase gene (GBA), which cause Gaucher disease, are also potent risk factors for Parkinson's disease. We examined whether a genetic burden of variants in other lysosomal storage disorder genes is more broadly associated with Parkinson's disease susceptibility. The sequence kernel association test was used to interrogate variant burden among 54 lysosomal storage disorder genes, leveraging whole exome sequencing data from 1156 Parkinson's disease cases and 1679 control subjects. We discovered a significant burden of rare, likely damaging lysosomal storage disorder gene variants in association with Parkinson's disease risk. The association signal was robust to the exclusion of GBA, and consistent results were obtained in two independent replication cohorts, including 436 cases and 169 controls with whole exome sequencing and an additional 6713 cases and 5964 controls with exome-wide genotyping. In secondary analyses designed to highlight the specific genes driving the aggregate signal, we confirmed associations at the GBA and SMPD1 loci and newly implicate CTSD, SLC17A5, and ASAH1 as candidate Parkinson's disease susceptibility genes. In our discovery cohort, the majority of Parkinson's disease cases (56%) have at least one putative damaging variant in a lysosomal storage disorder gene, and 21% carry multiple alleles. Our results highlight several promising new susceptibility loci and reinforce the importance of lysosomal mechanisms in Parkinson's disease pathogenesis. We suggest that multiple genetic hits may act in combination to degrade lysosomal function, enhancing Parkinson's disease susceptibility. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  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. Gene therapy approaches for lysosomal storage disorders, a good model for the treatment of mendelian diseases.

    Science.gov (United States)

    Tomanin, Rosella; Zanetti, Alessandra; Zaccariotto, Eva; D'Avanzo, Francesca; Bellettato, Cinzia M; Scarpa, Maurizio

    2012-07-01

    This review describes the different gene therapy technologies applied to approach lysosomal storage disorders, monogenic conditions, with known genetic and biochemical defects, for many of which animal models are available. Both viral and nonviral procedures are described, underlying the specific needs that the treatment of genetic disorders requires. Lysosomal storage disorders represent a good model of study of gene therapeutic procedures that are, or could be, relevant to the treatment of several other mendelian diseases. © 2012 The Author(s)/Acta Paediatrica © 2012 Foundation Acta Paediatrica.

  3. Building and Application of Cardiopulmonary Bypass Model in Rats

    Directory of Open Access Journals (Sweden)

    Zhang Kun

    2017-01-01

    Full Text Available To build a cardiopulmonary bypass model in rats, and research the feasibility. Method Cardiopulmonary bypass was built in 10 adult male SD rats of clean grade through intubation in jugular vein, caudal artery, and femoral artery, and bypass was sustained for 60 min at the flow rate of 100ml/(kg•min to monitor heart rate, blood pressure, blood gas, and electrolyte. Result Puncture succeeded in all the 20 rats, and cardiopulmonary bypass was finished under given conditions. Conclusion The model has the following advantages, economical efficiency, simplicity, minimal invasion, cardiopulmonary bypass parameter setting similar to that of clinical trail, high rate of success. Thus, it is reliable for researching pathological and physiological changes after cardiopulmonary bypass and evaluating therapeutic strategy.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    -destabilizing experimental anticancer agent siramesine inhibits ASM by interfering with the binding of ASM to its essential lysosomal cofactor, bis(monoacylglycero)phosphate. Like siramesine, several clinically relevant ASM inhibitors trigger cancer-specific lysosomal cell death, reduce tumor growth in vivo, and revert...

  5. Cocaine induces a mixed lysosomal lipidosis in cultured fibroblasts, by inactivation of acid sphingomyelinase and inhibition of phospholipase A1.

    Science.gov (United States)

    Nassogne, Marie-Cécile; Lizarraga, Chantal; N'Kuli, Francisca; Van Bambeke, Françoise; Van Binst, Roger; Wallemacq, Pierre; Tulkens, Paul M; Mingeot-Leclercq, Marie-Paule; Levade, Thierry; Courtoy, Pierre J

    2004-01-15

    This paper reports that cocaine may induce a lysosomal storage disorder. Indeed, culture of Rat-1 fibroblasts with 250-500 microM cocaine induced after 2-3 days a major accumulation in lysosomes of electron-dense lamellar structures. By subcellular fractionation, this was reflected by a selective decrease of the buoyant density of several lysosomal enzymes, indicating lysosomal lipid overload. Biochemical analysis confirmed an increased cellular content of major phospholipids and sphingomyelin, but not of cholesterol. Cocaine, a membrane-permeant weak base, is concentrated by acidotropic sequestration, because its accumulation was abrogated by the proton ionophore, monensin and the vacuolar ATPase inhibitor, bafilomycin A1. At its estimated lysosomal concentration, cocaine almost completely inhibited phospholipase A1 activity on liposomes. Cell incubation with cocaine, but not with its inactive metabolite, benzoylecgonine, rapidly inactivated acid sphingomyelinase, as reflected by a 10-fold decrease in Vmax with identical Km. Acid sphingomyelinase inactivation was fully prevented by the thiol proteinases inhibitors, leupeptin and E64, indicating that cocaine induces selective sphingomyelinase proteolysis. Upon cocaine removal, acid sphingomyelinase activity was rapidly restored, pointing to its fast turnover. In contrast, the cellular content of several other lysosomal hydrolases was increased up to 2-fold. Together, these data show that acidotropic accumulation of cocaine in lysosomes rapidly inhibits acid phospholipase A1 and inactivates acid sphingomyelinase, which can explain induction of a mixed lysosomal lipidosis.

  6. Cocaine induces a mixed lysosomal lipidosis in cultured fibroblasts, by inactivation of acid sphingomyelinase and inhibition of phospholipase A1

    International Nuclear Information System (INIS)

    Nassogne, Marie-Cecile; Lizarraga, Chantal; N'Kuli, Francisca; Van Bambeke, Francoise; Van Binst, Roger; Wallemacq, Pierre; Tulkens, Paul M.; Mingeot-Leclercq, Marie-Paule; Levade, Thierry; Courtoy, Pierre J.

    2004-01-01

    This paper reports that cocaine may induce a lysosomal storage disorder. Indeed, culture of Rat-1 fibroblasts with 250-500 μM cocaine induced after 2-3 days a major accumulation in lysosomes of electron-dense lamellar structures. By subcellular fractionation, this was reflected by a selective decrease of the buoyant density of several lysosomal enzymes, indicating lysosomal lipid overload. Biochemical analysis confirmed an increased cellular content of major phospholipids and sphingomyelin, but not of cholesterol. Cocaine, a membrane-permeant weak base, is concentrated by acidotropic sequestration, because its accumulation was abrogated by the proton ionophore, monensin and the vacuolar ATPase inhibitor, bafilomycin A 1 . At its estimated lysosomal concentration, cocaine almost completely inhibited phospholipase A 1 activity on liposomes. Cell incubation with cocaine, but not with its inactive metabolite, benzoylecgonine, rapidly inactivated acid sphingomyelinase, as reflected by a 10-fold decrease in V max with identical K m . Acid sphingomyelinase inactivation was fully prevented by the thiol proteinases inhibitors, leupeptin and E64, indicating that cocaine induces selective sphingomyelinase proteolysis. Upon cocaine removal, acid sphingomyelinase activity was rapidly restored, pointing to its fast turnover. In contrast, the cellular content of several other lysosomal hydrolases was increased up to 2-fold. Together, these data show that acidotropic accumulation of cocaine in lysosomes rapidly inhibits acid phospholipase A 1 and inactivates acid sphingomyelinase, which can explain induction of a mixed lysosomal lipidosis

  7. Transcription factor EB: from master coordinator of lysosomal pathways to candidate therapeutic target in degenerative storage diseases.

    Science.gov (United States)

    Sardiello, Marco

    2016-05-01

    The lysosome is the main catabolic hub of the cell. Owing to its role in fundamental processes such as autophagy, plasma membrane repair, mTOR signaling, and maintenance of cellular homeostasis, the lysosome has a profound influence on cellular metabolism and human health. Indeed, inefficient or impaired lysosomal function has been implicated in the pathogenesis of a number of degenerative diseases affecting various organs and tissues, most notably the brain, liver, and muscle. The discovery of the coordinated lysosomal expression and regulation (CLEAR) genetic program and its master controller, transcription factor EB (TFEB), has provided an unprecedented tool to study and manipulate lysosomal function. Most lysosome-based processes-including macromolecule degradation, autophagy, lysosomal exocytosis, and proteostasis-are under the transcriptional control of TFEB. Interestingly, impaired TFEB signaling has been suggested to be a contributing factor in the pathogenesis of several degenerative storage diseases. Preclinical studies based on TFEB exogenous expression to reinstate TFEB activity or promote CLEAR network-based lysosomal enhancement have highlighted TFEB as a candidate therapeutic target for the treatment of various degenerative storage diseases. © 2016 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.

  8. 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 p...

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

    Science.gov (United States)

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

    2017-03-01

    Parkinson's disease is characterized by accumulation of intraneuronal cytoplasmic inclusions, Lewy bodies, which mainly consist of aggregated α-synuclein. Controversies exist as to whether high blood cholesterol is a risk factor for the development of the disease and whether statin treatment could have a protective effect. Using a model system of BE(2)-M17 neuroblastoma cells treated with the neurotoxin 1-methyl-4-phenylpyridinium (MPP + ), we found that MPP + -induced cell death was accompanied by cholesterol accumulation in a lysosomal-like pattern in pre-apoptotic cells. To study the effects of lysosomal cholesterol accumulation, we increased lysosomal cholesterol through pre-treatment with U18666A and found delayed leakage of lysosomal contents into the cytosol, which reduced cell death. This suggests that increased lysosomal cholesterol is a stress response mechanism to protect lysosomal membrane integrity in response to early apoptotic stress. However, high cholesterol also stimulated the accumulation of α-synuclein. Treatment with the cholesterol-lowering drug lovastatin reduced MPP + -induced cell death by inhibiting the production of reactive oxygen species, but did not prevent lysosomal cholesterol increase nor affect α-synuclein accumulation. Our study indicates a dual role of high cholesterol in Parkinson's disease, in which it acts both as a protector against lysosomal membrane permeabilization and as a stimulator of α-synuclein accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Long-Term Lysosomes Tracking with a Water-Soluble Two-Photon Phosphorescent Iridium(III) Complex.

    Science.gov (United States)

    Qiu, Kangqiang; Huang, Huaiyi; Liu, Bingyang; Liu, Yukang; Huang, Ziyi; Chen, Yu; Ji, Liangnian; Chao, Hui

    2016-05-25

    Lysosomes are the stomachs of the cells that degrade endocytosis and intracellular biomacromolecules and participate in various other cellular processes, such as apoptosis and cell migration. The ability of long-term tracking of lysosomes is very important to understand the details of lysosomal functions and to evaluate drug and gene delivery systems. For studying lysosomes, we designed and synthesized a water-soluble triscyclometalated iridium(III) complex (Ir-lyso) attaching morpholine moieties. The phosphorescent intensity of Ir-lyso is responsive to pH and decreases with an increase in the pH but not quenching in high pH. With excellent two-photon properties, Ir-lyso was used to light up the lysosomes in living cells and 3D tumor spheroids. Moreover, Ir-lyso could label lysosomes more than 4 days, so we developed this complex to act as a long-term probe for tracking lysosomes during cell migration and apoptosis. To the best of our knowledge, this is the first paradigm of metal complexes as the two-photon phosphorescent probe for long-term lysosomes tracking.

  11. Disorders of lysosomal acidification-The emerging role of v-ATPase in aging and neurodegenerative disease.

    Science.gov (United States)

    Colacurcio, Daniel J; Nixon, Ralph A

    2016-12-01

    Autophagy and endocytosis deliver unneeded cellular materials to lysosomes for degradation. Beyond processing cellular waste, lysosomes release metabolites and ions that serve signaling and nutrient sensing roles, linking the functions of the lysosome to various pathways for intracellular metabolism and nutrient homeostasis. Each of these lysosomal behaviors is influenced by the intraluminal pH of the lysosome, which is maintained in the low acidic range by a proton pump, the vacuolar ATPase (v-ATPase). New reports implicate altered v-ATPase activity and lysosomal pH dysregulation in cellular aging, longevity, and adult-onset neurodegenerative diseases, including forms of Parkinson disease and Alzheimer disease. Genetic defects of subunits composing the v-ATPase or v-ATPase-related proteins occur in an increasingly recognized group of familial neurodegenerative diseases. Here, we review the expanding roles of the v-ATPase complex as a platform regulating lysosomal hydrolysis and cellular homeostasis. We discuss the unique vulnerability of neurons to persistent low level lysosomal dysfunction and review recent clinical and experimental studies that link dysfunction of the v-ATPase complex to neurodegenerative diseases across the age spectrum. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Phosphorylation of human aquaporin 2 (AQP2) allosterically controls its interaction with the lysosomal trafficking protein LIP5.

    NARCIS (Netherlands)

    Roche, J.V.; Survery, S.; Kreida, S.; Nesverova, V.; Ampah-Korsah, H.; Gourdon, M.; Deen, P.M.T.; Tornroth-Horsefield, S.

    2017-01-01

    The interaction between the renal water channel aquaporin-2 (AQP2) and the lysosomal trafficking regulator-interacting protein LIP5 targets AQP2 to multivesicular bodies and facilitates lysosomal degradation. This interaction is part of a process that controls AQP2 apical membrane abundance in a

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

    DEFF Research Database (Denmark)

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

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...... groups. Fractional loss of bicarbonate in urine was higher in controls than in bypass patients. The renal impairment is classified as distal renal tubular acidosis....

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

    DEFF Research Database (Denmark)

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

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients sho...... groups. Fractional loss of bicarbonate in urine was higher in controls than in bypass patients. The renal impairment is classified as distal renal tubular acidosis....

  15. Engineering of GlcNAc-1-Phosphotransferase for Production of Highly Phosphorylated Lysosomal Enzymes for Enzyme Replacement Therapy.

    Science.gov (United States)

    Liu, Lin; Lee, Wang-Sik; Doray, Balraj; Kornfeld, Stuart

    2017-06-16

    Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phosphorylate the mannose residues on their glycan chains. We show that co-expression of an engineered truncated GlcNAc-1-phosphotransferase α/β precursor and the lysosomal enzyme of interest in the producing cells resulted in markedly increased phosphorylation and cellular uptake of the secreted lysosomal enzyme. This method also results in the production of highly phosphorylated acid β-glucocerebrosidase, a lysosomal enzyme that normally has just trace amounts of this modification.

  16. 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.

  17. Heat exchanger bypass system for an absorption refrigeration system

    Science.gov (United States)

    Reimann, Robert C.

    1984-01-01

    A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

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

    Science.gov (United States)

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

    2015-08-01

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

  19. HEPES activates a MiT/TFE-dependent lysosomal-autophagic gene network in cultured cells: A call for caution.

    Science.gov (United States)

    Tol, Marc J; van der Lienden, Martijn J C; Gabriel, Tanit L; Hagen, Jacob J; Scheij, Saskia; Veenendaal, Tineke; Klumperman, Judith; Donker-Koopman, Wilma E; Verhoeven, Arthur J; Overkleeft, Hermen; Aerts, Johannes M; Argmann, Carmen A; van Eijk, Marco

    2018-02-17

    In recent years, the lysosome has emerged as a highly dynamic, transcriptionally regulated organelle that is integral to nutrient-sensing and metabolic rewiring. This is coordinated by a lysosome-to-nucleus signaling nexus in which MTORC1 controls the subcellular distribution of the microphthalmia-transcription factor E (MiT/TFE) family of "master lysosomal regulators". Yet, despite the importance of the lysosome in cellular metabolism, the impact of traditional in vitro culture media on lysosomal dynamics and/or MiT/TFE localization has not been fully appreciated. Here, we identify HEPES, a chemical buffering agent that is broadly applied in cell culture, as a potent inducer of lysosome biogenesis. Supplementation of HEPES to cell growth media is sufficient to decouple the MiT/TFE family members-TFEB, TFE3 and MITF-from regulatory mechanisms that control their cytosolic retention. Increased MiT/TFE nuclear import in turn drives the expression of a global network of lysosomal-autophagic and innate host-immune response genes, altering lysosomal dynamics, proteolytic capacity, autophagic flux, and inflammatory signaling. In addition, siRNA-mediated MiT/TFE knockdown effectively blunted HEPES-induced lysosome biogenesis and gene expression profiles. Mechanistically, we show that MiT/TFE activation in response to HEPES requires its macropinocytic ingestion and aberrant lysosomal storage/pH, but is independent of MTORC1 signaling. Altogether, our data underscore the cautionary use of chemical buffering agents in cell culture media due to their potentially confounding effects on experimental results.

  20. A saposin deficiency model in Drosophila: Lysosomal storage, progressive neurodegeneration and sensory physiological decline.

    Science.gov (United States)

    Hindle, Samantha J; Hebbar, Sarita; Schwudke, Dominik; Elliott, Christopher J H; Sweeney, Sean T

    2017-02-01

    Saposin deficiency is a childhood neurodegenerative lysosomal storage disorder (LSD) that can cause premature death within three months of life. Saposins are activator proteins that promote the function of lysosomal hydrolases that mediate the degradation of sphingolipids. There are four saposin proteins in humans, which are encoded by the prosaposin gene. Mutations causing an absence or impaired function of individual saposins or the whole prosaposin gene lead to distinct LSDs due to the storage of different classes of sphingolipids. The pathological events leading to neuronal dysfunction induced by lysosomal storage of sphingolipids are as yet poorly defined. We have generated and characterised a Drosophila model of saposin deficiency that shows striking similarities to the human diseases. Drosophila saposin-related (dSap-r) mutants show a reduced longevity, progressive neurodegeneration, lysosomal storage, dramatic swelling of neuronal soma, perturbations in sphingolipid catabolism, and sensory physiological deterioration. Our data suggests a genetic interaction with a calcium exchanger (Calx) pointing to a possible calcium homeostasis deficit in dSap-r mutants. Together these findings support the use of dSap-r mutants in advancing our understanding of the cellular pathology implicated in saposin deficiency and related LSDs. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Generation of specific deoxynojirimycin-type inhibitors of the non-lysosomal glucosylceramidase

    NARCIS (Netherlands)

    Overkleeft, H. S.; Renkema, G. H.; Neele, J.; Vianello, P.; Hung, I. O.; Strijland, A.; van der Burg, A. M.; Koomen, G. J.; Pandit, U. K.; Aerts, J. M.

    1998-01-01

    The existence of a non-lysosomal glucosylceramidase in human cells has been documented (van Weely, S., Brandsma, M., Strijland, A., Tager, J. M., and Aerts, J. M. F. G. (1993) Biochim. Biophys. Acta 1181, 55-62). Hypothetically, the activity of this enzyme, which is localized near the cell surface,

  2. The Endo-Lysosomal System of Brain Endothelial Cells Is Influenced by Astrocytes In Vitro.

    Science.gov (United States)

    Toth, Andrea E; Siupka, Piotr; P Augustine, Thomas J; Venø, Susanne T; Thomsen, Louiza B; Moos, Torben; Lohi, Hannes T; Madsen, Peder; Lykke-Hartmann, Karin; Nielsen, Morten S

    2018-03-20

    Receptor- and adsorptive-mediated transport through brain endothelial cells (BEC) of the blood-brain barrier (BBB) involves a complex array of subcellular vesicular structures, the endo-lysosomal system. It consists of several types of vesicles, such as early, recycling, and late endosomes, retromer-positive structures, and lysosomes. Since this system is important for receptor-mediated transcytosis of drugs across brain capillaries, our aim was to characterise the endo-lysosomal system in BEC with emphasis on their interactions with astrocytes. We used primary porcine BEC in monoculture and in co-culture with primary rat astrocytes. The presence of astrocytes changed the intraendothelial vesicular network and significantly impacted vesicular number, morphology, and distribution. Additionally, gene set enrichment analysis revealed that 60 genes associated with vesicular trafficking showed altered expression in co-cultured BEC. Cytosolic proteins involved in subcellular trafficking were investigated to mark transport routes, such as RAB25 for transcytosis. Strikingly, the adaptor protein called AP1-μ1B, important for basolateral sorting in epithelial cells, was not expressed in BEC. Altogether, our data pin-point unique features of BEC trafficking network, essentially mapping the endo-lysosomal system of in vitro BBB models. Consequently, our findings constitute a valuable basis for planning the optimal route across the BBB when advancing drug delivery to the brain.

  3. Excessive burden of lysosomal storage disorder gene variants in Parkinson's disease

    NARCIS (Netherlands)

    Robak, L.A.; Jansen, I.E.; Rooij, J van; Uitterlinden, A.G.; Kraaij, R.; Jankovic, J.; Heutink, P.; Shulman, J.M.; Bloem, B.; Post, B.; Scheffer, H.; Warrenburg, B.P.C. van de; et al.,

    2017-01-01

    Mutations in the glucocerebrosidase gene (GBA), which cause Gaucher disease, are also potent risk factors for Parkinson's disease. We examined whether a genetic burden of variants in other lysosomal storage disorder genes is more broadly associated with Parkinson's disease susceptibility. The

  4. The GARP Complex Is Involved in Intracellular Cholesterol Transport via Targeting NPC2 to Lysosomes.

    Science.gov (United States)

    Wei, Jian; Zhang, Ying-Yu; Luo, Jie; Wang, Ju-Qiong; Zhou, Yu-Xia; Miao, Hong-Hua; Shi, Xiong-Jie; Qu, Yu-Xiu; Xu, Jie; Li, Bo-Liang; Song, Bao-Liang

    2017-06-27

    Proper intracellular cholesterol trafficking is critical for cellular function. Two lysosome-resident proteins, NPC1 and NPC2, mediate the egress of low-density lipoprotein-derived cholesterol from lysosomes. However, other proteins involved in this process remain largely unknown. Through amphotericin B-based selection, we isolated two cholesterol transport-defective cell lines. Subsequent whole-transcriptome-sequencing analysis revealed two cell lines bearing the same mutation in the vacuolar protein sorting 53 (Vps53) gene. Depletion of VPS53 or other subunits of the Golgi-associated retrograde protein (GARP) complex impaired NPC2 sorting to lysosomes and caused cholesterol accumulation. GARP deficiency blocked the retrieval of the cation-independent mannose 6-phosphate receptor (CI-MPR) to the trans-Golgi network. Further, Vps54 mutant mice displayed reduced cellular NPC2 protein levels and increased cholesterol accumulation, underscoring the physiological role of the GARP complex in cholesterol transport. We conclude that the GARP complex contributes to intracellular cholesterol transport by targeting NPC2 to lysosomes in a CI-MPR-dependent manner. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. 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 incor...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  7. 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.

  8. Structural and functional analysis of lysosomal ss-galactosidase and its relation to the protective protein.

    NARCIS (Netherlands)

    H. Morreau (Hans)

    1992-01-01

    textabstractLysosomal B-galactosidase is the glycosidase, that cleaves B-linked galactosyl mmenes from a variety of natural and synthetic substrates. In normal tissues of various species this enzyme appears to associate with two other hydrolases, N-acetyl-o:-neuraminidase and the protective protein.

  9. Delayed lysosomal metabolism of lipids in mucolipidosis type IV fibroblasts after LDL-receptor-mediated endocytosis

    NARCIS (Netherlands)

    Jansen, S. M.; Groener, J. E.; Bax, W.; Poorthuis, B. J.

    2001-01-01

    We specifically probed the low-density lipoprotein-receptor-dependent endosomal/lysosomal pathway of lipid degradation in control and mucolipidosis type IV fibroblasts using either [choline-methyl-14C]sphingomyelin in complex with apolipoprotein E, or cholesteryl [14C]oleate-labelled low-density

  10. The serotonin transporter undergoes constitutive internalization and is primarily sorted to late endosomes and lysosomal degradation

    DEFF Research Database (Denmark)

    Rahbek-Clemmensen, Troels; Bay, Tina; Eriksen, Jacob

    2014-01-01

    . Furthermore, internalized SERT co-localized with the lysosomal marker LysoTracker and not with transferrin. The sorting pattern was further confirmed by visualizing internalization of SERT using the fluorescent cocaine analogue JHC1-64, and by reversible and pulse chase biotinylation assays showing evidence...

  11. AP-3 and Rabip4’ Coordinately Regulate Spatial Distribution of Lysosomes

    Science.gov (United States)

    Ivan, Viorica; Martinez-Sanchez, Emma; Sima, Livia E.; Oorschot, Viola; Klumperman, Judith; Petrescu, Stefana M.; van der Sluijs, Peter

    2012-01-01

    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. PMID:23144738

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  13. Effects of mercury on lysosomal protein digestion in the kidney proximal tubule

    International Nuclear Information System (INIS)

    Madsen, K.M.; Christensen, E.I.

    1978-01-01

    The effect of mercury on renal lysosomal protein digestion was studied after administration of mercury in vitro and in vivo. Mercuric chloride or methylmercury chloride was added in vitro to lysosomal enzymes isolated from normal rats, and subsequently, digestion experiments were carried out using 125 I-labeled lysozyme or cytochrome c as substrate proteins. Both mercury compounds produced a concentration-dependent inhibition of the degradation of the proteins, mercuric chloride being the strongest inhibitor. Mercuric chloride was also administered to rats in vivo for 5 to 8 months. Renal lysosomal enzymes from these animals also had a decreased ability to digest the two substrate proteins. Furthermore, the digestion of lysozyme intravenously injected into mercury-intoxicated rats was decreased in renal cortical slices incubated in vitro. Electron microscope autoradiography showed that intravenously injected labeled lysozyme was located primarily over lysosomes in proximal tubule cells 1 hour after injection in both control animals and mercury-intoxicated rats. These results suggest a decreased catabolism of low molecular weight proteins in the kidney during chronic mercury intoxication

  14. Lysosome-Targeting Amplifiers of Reactive Oxygen Species as Anticancer Prodrugs

    Czech Academy of Sciences Publication Activity Database

    Daum, S.; Reshetnikov, M.S.V.; Šíša, Miroslav; Dumych, T.; Lootsik, M. D.; Bilyy, R.; Bila, E.; Janko, C.; Alexiou, C.; Herrmann, M.; Sellner, L.; Mokhir, A.

    2017-01-01

    Roč. 56, č. 49 (2017), s. 15545-15549 ISSN 1433-7851 Institutional support: RVO:61389030 Keywords : aminoferrocene * cancer * lysosomes * prodrugs * reactive oxygen species Subject RIV: ED - Physiology OBOR OECD: Organic chemistry Impact factor: 11.994, year: 2016

  15. The lysosomal enzymes acid phosphatase and cathepsin D in rats intoxicated with Senna occidentalis seeds.

    Science.gov (United States)

    Calore, E E; Calore, N M; Weg, R; Cavaliere, M J; Ruckert da Rosa, A; De Souza Dias, S

    1999-04-01

    Chronic administration of Senna occidentalis seeds induces an experimental toxic myopathy characterized by skeletal muscle fibers atrophy, decrease in histochemical activity of cytochrome oxidase, and increase of the acid phosphatase activity in muscle fibres at the light microscopic level. The mechanisms that lead to the increase of this lysosomal enzyme activity are not known and could be related to other biochemical disturbs than the mitochondrial function impairment. The main aim of the present study is to localize the acid phosphatase activity using a cytochemical method at transmission electron microscopy level and to quantify cathepsin D in muscle of rats chronically intoxicated with Senna occidentalis seeds by immunoblotting. Acid phosphatase was observed in lysosomes and over profiles of some organelles apparently not involved by lysosomal membrane. In addition immunoblotting demonstrated a decrease in the content of the precursor and of the mature form of cathepsin D in samples of muscles and liver of intoxicated animals. We concluded that there is a selective increase in acid phosphatase activity in muscle--and maybe in other tissues--of animals intoxicated with Senna occidentalis, that can be related to the skeletal muscle atrophy and the intense decrease in weight gain of these animals. Further studies should be performed to establish the mechanisms of selectivity in increase of lysosomal enzymes in different situations and pathological states.

  16. Antibody-mediated enzyme replacement therapy targeting both lysosomal and cytoplasmic glycogen in Pompe disease.

    Science.gov (United States)

    Yi, Haiqing; Sun, Tao; Armstrong, Dustin; Borneman, Scott; Yang, Chunyu; Austin, Stephanie; Kishnani, Priya S; Sun, Baodong

    2017-05-01

    Pompe disease is characterized by accumulation of both lysosomal and cytoplasmic glycogen primarily in skeletal and cardiac muscles. Mannose-6-phosphate receptor-mediated enzyme replacement therapy (ERT) with recombinant human acid α-glucosidase (rhGAA) targets the enzyme to lysosomes and thus is unable to digest cytoplasmic glycogen. Studies have shown that anti-DNA antibody 3E10 penetrates living cells and delivers "cargo" proteins to the cytosol or nucleus via equilibrative nucleoside transporter ENT2. We speculate that 3E10-mediated ERT with GAA will target both lysosomal and cytoplasmic glycogen in Pompe disease. A fusion protein (FabGAA) containing a humanized Fab fragment derived from the murine 3E10 antibody and the 110 kDa human GAA precursor was constructed and produced in CHO cells. Immunostaining with an anti-Fab antibody revealed that the Fab signals did not co-localize with the lysosomal marker LAMP2 in cultured L6 myoblasts or Pompe patient fibroblasts after incubation with FabGAA. Western blot with an anti-GAA antibody showed presence of the 150 kDa full-length FabGAA in the cell lysates, in addition to the 95- and 76 kDa processed forms of GAA that were also seen in the rhGAA-treated cells. Blocking of mannose-6-phosphate receptor with mannose-6-phosphate markedly reduced the 95- and the 76 kDa forms but not the 150 kDa form. In GAA-KO mice, FabGAA achieved similar treatment efficacy as rhGAA at an equal molar dose in reducing tissue glycogen contents. Our data suggest that FabGAA retains the ability of rhGAA to treat lysosomal glycogen accumulation and has the beneficial potential over rhGAA to reduce cytoplasmic glycogen storage in Pompe disease. FabGAA can be delivered to both the cytoplasm and lysosomes in cultured cells. FabGAA equally reduced lysosomal glycogen accumulation as rhGAA in GAA-KO mice. FabGAA has the beneficial potential over rhGAA to clear cytoplasmic glycogen. This study suggests a novel antibody-enzyme fusion protein therapy

  17. 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.

  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. Work on the Geneva motorway bypass

    CERN Multimedia

    État de Genève, DCTI, Direction du génie civil

    2006-01-01

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

  20. Ascorbic Acid Modulation of Iron Homeostasis and Lysosomal Function in Trabecular Meshwork Cells

    Science.gov (United States)

    Xu, Ping; Lin, Yizhi; Porter, Kristine

    2014-01-01

    Abstract Purpose: To investigate the antioxidant properties and biological functions of ascorbic acid (AA) on trabecular meshwork (TM) cells. Methods: Primary cultures of porcine TM cells were supplemented for 10 days with increasing concentrations of AA. Antioxidant properties against cytotoxic effect of H2O2 were evaluated by monitoring cell viability. Redox-active iron was quantified using calcein-AM. Intracellular reactive oxygen species (iROS) production was quantified using H2DCFDA. Ferritin and cathepsin protein levels were analyzed by Western blot. Autophagy was evaluated by monitoring lipidation of LC3-I to LC3-II. Lysosomal proteolysis and cathepsins activities were quantified using specific fluorogenic substrates. Results: AA exerts a dual effect against oxidative stress in TM cells, acting as an anti-oxidant or a pro-oxidant, depending on the concentration used. The pro-oxidant effect of AA was mediated by free intracellular iron and correlated with increased protein levels of ferritin and elevated iROS. In contrast, antioxidant properties correlated with lower ferritin and basal iROS content. Ascorbic acid supplementation also caused induction of autophagy, as well as increased lysosomal proteolysis, with the latter resulting from higher proteolytic activation of lysosomal cathepsins in treated cultures. Conclusions: Our results suggest that the reported decrease of AA levels in plasma and aqueous humor can compromise lysosomal degradation in the outflow pathway cells with aging and contribute to the pathogenesis of glaucoma. Restoration of physiological levels of vitamin C inside the cells might improve their ability to degrade proteins within the lysosomal compartment and recover tissue function. PMID:24552277

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    Rachel A Idol

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

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

    Science.gov (United States)

    Idol, Rachel A; Wozniak, David F; Fujiwara, Hideji; Yuede, Carla M; Ory, Daniel S; Kornfeld, Stuart; Vogel, Peter

    2014-01-01

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

  4. Digestion of thyroglobulin with purified thyroid lysosomes: preferential release of iodoamino acids

    International Nuclear Information System (INIS)

    Tokuyama, T.; Yoshinari, M.; Rawitch, A.B.; Taurog, A.

    1987-01-01

    [ 131 I]Thyroglobulin [( 131 I]Tg), prepared by either enzymatic iodination of human goiter Tg in vitro or isolation from the thyroids of rats previously injected with 131 I, was digested with a solubilized enzyme mixture prepared from purified hog thyroid lysosomes. The digestion was performed at 37 C for 24 h under nitrogen at pH 5.0 in the presence of 4 mM dithiothreitol. Under these conditions the release of free [ 131 I] iodoamino acids (MIT, DIT, T4, and T3) was quantitatively very similar to that observed with a standard pronase digestion procedure. To determine whether other amino acids in Tg were released as quantitatively as the iodoamino acids, free amino acids in the lysosomal digest were measured, and total free amino acid release was compared with a similar analysis performed after digestion of [ 131 I]Tg with 6 N HCl. Total amino acid release was much less complete than iodoamino acid release, indicating preferential release of iodoamino acids from Tg by lysosomal digestion. Analysis of the lysosomal digest by HPLC on a size exclusion column indicated that Tg was degraded to peptides with a mol wt less than 4000. Assuming that the in vitro lysosomal digestion system represents a valid model for the physiological proteolytic system that degrades Tg, the results of the present study suggest that a substantial portion of the Tg in the thyroid is not degraded to free amino acids and that peptide fragments of Tg are normally present in the thyroid. In such a case, the fate and possible physiological activity of these fragments require further elucidation

  5. 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

  6. 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.

    2016-01-01

    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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  8. 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.

  9. The laparoscopic banded gastric bypass – operation technique

    Directory of Open Access Journals (Sweden)

    Simon Küsters

    2010-03-01

    Full Text Available The banded Roux-en-Y gastric bypass can be used as a primary or revisionary bariatric procedure. This article describesthe operation technique including materials, size and placement of the banding and gives an overview con cerningevolution and indications of the operation. A video of a primary banded Roux-en-Y gastric bypass is presented.

  10. 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

  11. Outcomes of coronary artery bypass graft surgery

    Directory of Open Access Journals (Sweden)

    Anna Louise Hawkes

    2006-12-01

    Full Text Available Anna Louise Hawkes1,3, Madeleine Nowak1, Benjamin Bidstrup2, Richard Speare11School of Public Health, Tropical, Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland, Australia (3Currently Queensland Cancer Fund; 2John Flynn Hospital, Gold Coast, Queensland, AustraliaAbstract: This review article summarizes the major studies that have investigated the outcomes of coronary artery bypass graft surgery (CABG. The article includes a review of the literature in the areas of: history of CABG; indications for CABG; and measurement of quality of life following CABG, including prolongation of life, physical functioning (ie, relief from angina and dyspnea, physical activity, as well as complications of surgery and re-hospitalization, psychological functioning, and social functioning. Overall, the literature demonstrates that the outcomes of CABG have historically been measured in terms of mortality and morbidity; however, it has now been well recognized that adjustment to CABG is a multidimensional phenomenon that is not fully explained by medical factors. Therefore, in addition to studying mortality and morbidity outcomes following CABG, many recent studies have identified that it is important to investigate various physical, psychological, and social variables that have a significant impact on post-operative adjustment to CABG. Keywords: coronary artery bypass graft surgery, outcomes, quality of life, recovery

  12. Autophagy Inhibits the Accumulation of Advanced Glycation End Products by Promoting Lysosomal Biogenesis and Function in the Kidney Proximal Tubules.

    Science.gov (United States)

    Takahashi, Atsushi; Takabatake, Yoshitsugu; Kimura, Tomonori; Maejima, Ikuko; Namba, Tomoko; Yamamoto, Takeshi; Matsuda, Jun; Minami, Satoshi; Kaimori, Jun-Ya; Matsui, Isao; Matsusaka, Taiji; Niimura, Fumio; Yoshimori, Tamotsu; Isaka, Yoshitaka

    2017-05-01

    Advanced glycation end products (AGEs) are involved in the progression of diabetic nephropathy. AGEs filtered by glomeruli or delivered from the circulation are endocytosed and degraded in the lysosomes of kidney proximal tubular epithelial cells (PTECs). Autophagy is a highly conserved degradation system that regulates intracellular homeostasis by engulfing cytoplasmic components. We have recently demonstrated that autophagic degradation of damaged lysosomes is indispensable for cellular homeostasis in some settings. In this study, we tested the hypothesis that autophagy could contribute to the degradation of AGEs in the diabetic kidney by modulating lysosomal biogenesis. Both a high-glucose and exogenous AGE overload gradually blunted autophagic flux in the cultured PTECs. AGE overload upregulated lysosomal biogenesis and function in vitro, which was inhibited in autophagy-deficient PTECs because of the impaired nuclear translocation of transcription factor EB. Consistently, streptozotocin-treated, PTEC-specific, autophagy-deficient mice failed to upregulate lysosomal biogenesis and exhibited the accumulation of AGEs in the glomeruli and renal vasculature as well as in the PTECs, along with worsened inflammation and fibrosis. These results indicate that autophagy contributes to the degradation of AGEs by the upregulation of lysosomal biogenesis and function in diabetic nephropathy. Strategies aimed at promoting lysosomal function hold promise for treating diabetic nephropathy. © 2017 by the American Diabetes Association.

  13. 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.

  14. 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.

  15. 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

  16. Lysosomal function is involved in 17β-estradiol-induced estrogen receptor α degradation and cell proliferation.

    Science.gov (United States)

    Totta, Pierangela; Pesiri, Valeria; Marino, Maria; Acconcia, Filippo

    2014-01-01

    The homeostatic control of the cellular proteome steady-state is dependent either on the 26S proteasome activity or on the lysosome function. The sex hormone 17β-estradiol (E2) controls a plethora of biological functions by binding to the estrogen receptor α (ERα), which is both a nuclear ligand-activated transcription factor and also an extrinsic plasma membrane receptor. Regulation of E2-induced physiological functions (e.g., cell proliferation) requires the synergistic activation of both transcription of estrogen responsive element (ERE)-containing genes and rapid extra-nuclear phosphorylation of many different signalling kinases (e.g., ERK/MAPK; PI3K/AKT). Although E2 controls ERα intracellular content and activity via the 26S proteasome-mediated degradation, biochemical and microscopy-based evidence suggests a possible cross-talk among lysosomes and ERα activities. Here, we studied the putative localization of endogenous ERα to lysosomes and the role played by lysosomal function in ERα signalling. By using confocal microscopy and biochemical assays, we report that ERα localizes to lysosomes and to endosomes in an E2-dependent manner. Moreover, the inhibition of lysosomal function obtained by chloroquine demonstrates that, in addition to 26S proteasome-mediated receptor elimination, lysosome-based degradation also contributes to the E2-dependent ERα breakdown. Remarkably, the lysosome function is further involved in those ERα activities required for E2-dependent cell proliferation while it is dispensable for ERα-mediated ERE-containing gene transcription. Our discoveries reveal a novel lysosome-dependent degradation pathway for ERα and show a novel biological mechanism by which E2 regulates ERα cellular content and, as a consequence, cellular functions.

  17. 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...

  18. Silymarin and vitamin E reduce amiodarone-induced lysosomal phospholipidosis in rats

    International Nuclear Information System (INIS)

    Agoston, Marta; Oersi, Ferenc; Feher, Erzsebet; Hagymasi, Krisztina; Orosz, Zsuzsa; Blazovics, Anna; Feher, Janos; Vereckei, Andras

    2003-01-01

    Several antioxidants have been shown to reduce lysosomal phospholipidosis, which is a potential mechanism of amiodarone toxicity, and prevent amiodarone toxicity by antioxidant and/or non-antioxidant mechanisms. The aim of this study was to test whether the co-administration of two structurally different antioxidants vitamin E and silymarin with amiodarone can reduce amiodarone-induced lysosomal phospholipidosis, and if yes, by reducing the tissue concentration of amiodarone and desethylamiodarone or by their antioxidant action. To this end, male Fischer 344 rats were treated by gavage once a day for 3 weeks and randomly assigned to the following four experimental groups: 1, control; 2, amiodarone (150 mg/(kg per day)); 3, amiodarone (150 mg/(kg per day)) plus vitamin E (100 mg/(kg per day)); 4, amiodarone (150 mg/(kg per day)) plus silymarin (60 mg/(kg per day)) treated groups. Total plasma phospholipid (PL), liver-conjugated diene, thiobarbituric acid reactive substances (TBARSs), amiodarone and desethylamiodarone concentrations were determined and the extent of lysosomal phospholipidosis in the liver was estimated by a semi-quantitative electron microscopic method. Amiodarone treatment increased significantly the liver-conjugated diene (P<0.001), TBARS (P=0.012), plasma total PL (P<0.001) concentrations compared with control. Antioxidants combined with amiodarone significantly decreased the liver-conjugated diene (P<0.001 for both), TBARS (P=0.016 for vitamin E, P=0.053 borderline for silymarin) and plasma total PL (P=0.058 borderline for vitamin E, P<0.01 for silymarin) concentrations compared with amiodarone treatment alone. Silymarin significantly (P=0.021) reduced liver amiodarone, but only tended to decrease desethylamiodarone concentration; however, vitamin E failed to do so. Amiodarone treatment increased lysosomal phospholipidosis (P<0.001) estimated by semi-quantitative electron microscopic method and both antioxidants combined with amiodarone reduced

  19. 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

  20. 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.

  1. Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease.

    Science.gov (United States)

    Seyrantepe, Volkan; Demir, Secil Akyildiz; Timur, Zehra Kevser; Von Gerichten, Johanna; Marsching, Christian; Erdemli, Esra; Oztas, Emin; Takahashi, Kohta; Yamaguchi, Kazunori; Ates, Nurselin; Dönmez Demir, Buket; Dalkara, Turgay; Erich, Katrin; Hopf, Carsten; Sandhoff, Roger; Miyagi, Taeko

    2018-01-01

    Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa -/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa -/- Neu3 -/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa -/- Neu3 -/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa -/- Neu3 -/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa -/- Neu3 -/- mice. Thus, the Hexa -/- Neu3 -/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Making Pure Science and Pure Politics: On the Expertise of Bypass and the Bypass of Expertise

    Czech Academy of Sciences Publication Activity Database

    Konopásek, Z.; Stöckelová, Tereza; Zamykalová, L.

    2008-01-01

    Roč. 33, č. 4 (2008), s. 529-553 ISSN 0162-2439 R&D Projects: GA MŠk 1P05OK459 Institutional research plan: CEZ:AV0Z70280505; CEZ:AV0Z90090514 Keywords : expertise * politics * highway bypass Subject RIV: AO - Sociology, Demography Impact factor: 1.926, year: 2008 http:// sth .sagepub.com/cgi/content/refs/33/4/529

  3. 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

    proteins, we have investigated the down-regulation of EGFRvIII and compared it to that of EGFR. We show that, in contrast to EGFR, EGFRvIII is inefficiently degraded. EGFRvIII is internalized, but the internalization rate of the mutated receptor is significantly less than that of unstimulated EGFR....... 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...... results suggest that the long lifetime of EGFRvIII is caused by inefficient internalization and impaired sorting to lysosomes due to lack of effective ubiquitinylation....

  4. 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...

  5. Biomarkers in the diagnosis of lysosomal storage disorders: proteins, lipids, and inhibodies.

    Science.gov (United States)

    Aerts, Johannes M F G; Kallemeijn, Wouter W; Wegdam, Wouter; Joao Ferraz, Maria; van Breemen, Marielle J; Dekker, Nick; Kramer, Gertjan; Poorthuis, Ben J; Groener, Johanna E M; Cox-Brinkman, Josanne; Rombach, Saskia M; Hollak, Carla E M; Linthorst, Gabor E; Witte, Martin D; Gold, Henrik; van der Marel, Gijs A; Overkleeft, Herman S; Boot, Rolf G

    2011-06-01

    A biomarker is an analyte indicating the presence of a biological process linked to the clinical manifestations and outcome of a particular disease. In the case of lysosomal storage disorders (LSDs), primary and secondary accumulating metabolites or proteins specifically secreted by storage cells are good candidates for biomarkers. Clinical applications of biomarkers are found in improved diagnosis, monitoring disease progression, and assessing therapeutic correction. These are illustrated by reviewing the discovery and use of biomarkers for Gaucher disease and Fabry disease. In addition, recently developed chemical tools allowing specific visualization of enzymatically active lysosomal glucocerebrosidase are described. Such probes, coined inhibodies, offer entirely new possibilities for more sophisticated molecular diagnosis, enzyme replacement therapy monitoring, and fundamental research.

  6. 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.

  7. Localization of acid hydrolases in protoplasts. Examination of the proposed lysosomal function of the mature vacuole

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, H.C.; Wagner, G.J.; Siegelman, H.W.

    1977-06-01

    The development of techniques to isolate and purify relatively large quantities of intact vacuoles from mature tissues permits direct biochemical analysis of this ubiquitous mature plant cell organelle. Vacuoles and a fraction enriched in soluble cytoplasmic constituents were quantitatively prepared from Hippeastrum flower petal protoplasts. Vacuolar lysate and soluble cytoplasmic fractions were examined for acid hydrolase activities commonly associated with animal lysosomes, and pH optima were determined. Esterase, protease, carboxypeptidase, ..beta..-galactosidase, ..cap alpha..-glycosidase and ..beta..-glycosidase, not found in the vacuole lysate fraction, were components of the soluble cytoplasmic fraction. Acid phosphatase, RNase and DNase were present in both fractions. Vacuolar enzyme activities were also examined as a function of flower development from bud through senescent stages. The data obtained are not consistent with the concept that the mature plant cell vacuole functions as a generalized lysosome.

  8. Pregnancy outcomes after gastric-bypass surgery.

    Science.gov (United States)

    Dao, Tuoc; Kuhn, Joseph; Ehmer, Dale; Fisher, Tammy; McCarty, Todd

    2006-12-01

    The purpose of this study is to compare outcomes of patients who become pregnant within the first year after surgery and those who delayed pregnancy until after 1 year after surgery. A retrospective review was performed to identify patients who became pregnant after their gastric-bypass surgery from 2001 to 2004. Endpoints included pregnancy complications, fetal birth weight and outcome, delivery method, weight change during pregnancy, and nutrition. Of 2,423 patients who had undergone bariatric surgery from 2001 to 2004, 21 patients became pregnant within the first year after surgery and 13 became pregnant after 1 year. Similar outcomes were seen between the 2 groups regarding fetal weight, term pregnancy, and complications. Pregnancy outcomes within the first year after weight-loss surgery revealed no significant episodes of malnutrition, adverse fetal outcomes, or pregnancy complications. Anxiety over poor outcomes of pregnancy during the first year after bariatric surgery can be allayed.

  9. Transient Diabetes Insipidus Following Cardiopulmonary Bypass.

    Science.gov (United States)

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

    2015-04-01

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

  10. Factor V Leiden and Cardiopulmonary Bypass.

    Science.gov (United States)

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

    2015-12-01

    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 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.

  11. 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.

  12. Laparoscopic Conversion of One Anastomosis Gastric Bypass to a Standard Roux-en-Y Gastric Bypass.

    Science.gov (United States)

    Amor, Imed Ben; Petrucciani, Niccolo; Kassir, Radwan; Al Munifi, Abdullah; Piche, Thierry; Debs, Tarek; Gugenheim, Jean

    2017-05-01

    One anastomosis gastric bypass (OAGB) demonstrated results similar to traditional Roux-en-Y procedures [1-3], in terms of weight loss and resolution of obesity-related comorbidities. The main controversy regarding OAGB is the concern for an association between biliary alkaline gastritis and esophageal or gastric cancer raised by some studies [4]. We present the case of a 51-year-old woman with a BMI of 41 kg/m2 who underwent a laparoscopic OAGB in 2014. One year later, she consulted for recurrent heartburns. An upper GI endoscopy showed pouchitis and bile reflux in the esophagus. Medical treatment of gastroesophageal reflux disease was ineffective. We decided to convert the OAGB to a Roux-en-Y gastric bypass (RYGB). In this video, we show how to revise an OAGB to treat chronic bile reflux, by converting the procedure to a standard RYGB. The intervention starts by restoring the normal anatomy of the small bowel, with the resection of the gastrojejunal anastomosis, which was located at 250-cm du Treitz's ligament. Then, the gastric pouch is created. A standard Roux-en-Y gastric bypass is performed. The resection of the gastrojejunal anastomosis allows fashioning the Roux-en-Y limb with the classical measures. This technique allows a conversion to a standard RYGB and is effective in treating the biliary reflux.

  13. Cholesteryl hemiesters alter lysosome structure and function and induce proinflammatory cytokine production in macrophages.

    Science.gov (United States)

    Domingues, Neuza; Estronca, Luís M B B; Silva, João; Encarnação, Marisa R; Mateus, Rita; Silva, Diogo; Santarino, Inês B; Saraiva, Margarida; Soares, Maria I L; Pinho E Melo, Teresa M V D; Jacinto, António; Vaz, Winchil L C; Vieira, Otília V

    2017-02-01

    Cholesteryl hemiesters are oxidation products of polyunsaturated fatty acid esters of cholesterol. Their oxo-ester precursors have been identified as important components of the "core aldehydes" of human atheromata and in oxidized lipoproteins (Ox-LDL). We had previously shown, for the first time, that a single compound of this family, cholesteryl hemisuccinate (ChS), is sufficient to cause irreversible lysosomal lipid accumulation (lipidosis), and is toxic to macrophages. These features, coupled to others such as inflammation, are typically seen in atherosclerosis. To obtain insights into the mechanism of cholesteryl hemiester-induced pathological changes in lysosome function and induction of inflammation in vitro and assess their impact in vivo. We have examined the effects of ChS on macrophages (murine cell lines and primary cultures) in detail. Specifically, lysosomal morphology, pH, and proteolytic capacity were examined. Exposure of macrophages to sub-toxic ChS concentrations caused enlargement of the lysosomes, changes in their luminal pH, and accumulation of cargo in them. In primary mouse bone marrow-derived macrophages (BMDM), ChS-exposure increased the secretion of IL-1β, TNF-α and IL-6. In zebrafish larvae (wild-type AB and PU.1:EGFP), fed with a ChS-enriched diet, we observed lipid accumulation, myeloid cell-infiltration in their vasculature and decrease in larval survival. Under the same conditions the effects of ChS were more profound than the effects of free cholesterol (FC). Our data strongly suggest that cholesteryl hemiesters are pro-atherogenic lipids able to mimic features of Ox-LDL both in vitro and in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A cyanobenzo[a]phenoxazine-based near infrared lysosome-tracker for in cellulo imaging.

    Science.gov (United States)

    Sun, Ru; Liu, Wu; Xu, Yu-Jie; Lu, Jian-Mei; Ge, Jian-Feng; Ihara, Masataka

    2013-11-25

    A cyanobenzo[a]phenoxazine-based pH probe with pKa = 5.0 exhibits OFF-ON emission at 625-850 nm upon excitation at 600 nm in aqueous buffers. The in cellulo imaging experiments with HeLa cells indicate that the probe can serve as a lysosome-specific probe under red light excitation (633 nm) with near infrared emission (650-790 nm).

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

    International Nuclear Information System (INIS)

    Dashwood, Wan-Mohaiza; Carter, Orianna; Al-Fageeh, Mohamed; Li, Qingjie; Dashwood, Roderick H.

    2005-01-01

    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

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    G.B. Peres

    2014-06-01

    Full Text Available It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old, while 26 age-matched controls received only vehicle. The livers were removed on either the 10th or the 30th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA of cathepsins B and L was also decreased on the 10th, but not on the 30th day. Sulfatase decreased 30% on the 30th day, while glycosidases did not vary (or presented a transitory and slight decrease. There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

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

    OpenAIRE

    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 ma...

  20. The role of lysosomal proteolytic enzymes in invasion and dissemination of malignant melanoma

    International Nuclear Information System (INIS)

    Bassalyk, L.S.; Tsanev, P.E.; Parshikova, S.M.; Demidov, L.V.

    1992-01-01

    Preoperative chemo- and radiation therapy was followed by a decrease in lysosomal cathepsins activity in metastatic lymph nodes which, however, did not reach the level established for intact lymph nodes. The pathogenetic role of proteolytic endopeptidases in invasion and sissemination of malignant melanoma is discussed as well as the value of their level measurement for assessing metastatic potential of tumor and prognosis of disease of disease on the basis of tumor site, degree of invasion regional lymph node status

  1. A Genome-wide RNAi Screen for Microtubule Bundle Formation and Lysosome Motility Regulation in Drosophila S2 Cells

    Directory of Open Access Journals (Sweden)

    Amber L. Jolly

    2016-01-01

    Full Text Available Long-distance intracellular transport of organelles, mRNA, and proteins (“cargo” occurs along the microtubule cytoskeleton by the action of kinesin and dynein motor proteins, but the vast network of factors involved in regulating intracellular cargo transport are still unknown. We capitalize on the Drosophila melanogaster S2 model cell system to monitor lysosome transport along microtubule bundles, which require enzymatically active kinesin-1 motor protein for their formation. We use an automated tracking program and a naive Bayesian classifier for the multivariate motility data to analyze 15,683 gene phenotypes and find 98 proteins involved in regulating lysosome motility along microtubules and 48 involved in the formation of microtubule filled processes in S2 cells. We identify innate immunity genes, ion channels, and signaling proteins having a role in lysosome motility regulation and find an unexpected relationship between the dynein motor, Rab7a, and lysosome motility regulation.

  2. Virus replication, cytopathology, and lysosomal enzyme response of mitotic and interphase Hep-2 cells infected with poliovirus.

    Science.gov (United States)

    Bienz, K; Egger, D; Wolff, D A

    1973-04-01

    Mitotic Hep-2 cells, selected by the PEL (colloidal silica) density gradient method and held in mitosis with Colcemid, are readily infected by poliovirus type I (Mahoney). They produce and release the same amount of virus as interphase, random-growing cells. In contrast to interphase cells, mitotic cells show no detectable virus-induced cytopathic effect at the light microscopy level and only slight alterations, consisting of small clusters of vacuoles, at the electron microscopy level. Mitotic cells contain the same total amount of lysosomal enzymes per cell as interphase cells, but they display no redistribution of lysosomal enzymes during the virus infection as interphase cells do. This supports the view that lysosomal enzyme redistribution is associated with the cytopathic effect in poliovirus infection but shows that virus synthesis and release is not dependent on either the cytopathic effect or lysosomal enzyme release. The possible reasons for the lack of cytopathic effect in mitotic cells are discussed.

  3. Demonstration of the existence of a second, non-lysosomal glucocerebrosidase that is not deficient in Gaucher disease

    NARCIS (Netherlands)

    van Weely, S.; Brandsma, M.; Strijland, A.; Tager, J. M.; Aerts, J. M.

    1993-01-01

    In addition to the lysosomal glucocerebrosidase, a distinct beta-glucosidase that is also active towards glucosylceramide could be demonstrated in various human tissues and cell types. Subcellular fractionation analysis revealed that the hitherto undescribed glucocerebrosidase is not located in

  4. Generation of a lysosomal enzyme targeting signal in the secretory protein pepsinogen.

    Science.gov (United States)

    Baranski, T J; Faust, P L; Kornfeld, S

    1990-10-19

    Lysosomal enzymes contain a common protein determinant that is recognized by UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase, the initial enzyme in the formation of mannose 6-phosphate residues. To identify this protein determinant, we constructed chimeric molecules between two aspartyl proteases: cathepsin D, a lysosomal enzyme, and pepsinogen, a secretory protein. When expressed in Xenopus oocytes, the oligosaccharides of cathepsin D were efficiently phosphorylated, whereas the oligosaccharides of a glycosylated form of pepsinogen were not phosphorylated. The combined substitution of two noncontinuous sequences of cathepsin D (lysine 203 and amino acids 265-292) into the analogous positions of glycopepsinogen resulted in phosphorylation of the oligosaccharides of the expressed chimeric molecule. These two sequences are in direct apposition on the surface of the molecule, indicating that amino acids from different regions come together in three-dimensional space to form this recognition domain. Other regions of cathepsin D were identified that may be components of a more extensive recognition marker.

  5. Response of tissue lysosomes in Gamma-irradiated rats and possible modulation through diclofenac treatment

    International Nuclear Information System (INIS)

    Hassan, S.H.S.; Abu-Ghadeer, A.R.M.; Osman, S.A.A.

    1995-01-01

    The effect of pre and post-irradiation treatment of rats with diclofenac (5 mg kg-1) for modulating the damaging effect of radiation on tissue lysosomes was investigated. The parameters used for this study were the activity level of acid phosphatase (ACP) and acid ribonuclease (RNase) activities, both being hydrolytic enzymes of lysosomes. The activities of ACP and RNase in liver, spleen, intestine, kidney, lung and brain were determined at different times up to 14 days after irradiation (4(Gy). Lysosomal affection was represented by time dependent significant increase in ACP activity in all the tissue homogenates of the investigated organs 3, 7 and 14 days after irradiation at 4 Gy. Gamma irradiation at 4 Gy resulted also in a significant rise in RNase activity of all the tissue organs 3 days post-irradiation. However, gradual decrease in the enzyme activity was recorded 7 and 14 days following irradiation. Diclofenac, pre (as prophylactic) and post (as therapeutic) irradiation treatment of rats successfully restored the increase in the enzymatic activities of ACP and RNase nearly to their normal levels in all the investigated organs. The beneficial effect of diclofenac inhibited completely the effect of irradiation at 14 days post-exposure. 2 figs., 2 tabs

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

    Directory of Open Access Journals (Sweden)

    Akihiko Urayama

    Full Text Available The impermeability of the adult blood-brain barrier (BBB to lysosomal enzymes impedes the ability to treat the central nervous system manifestations of lysosomal storage diseases. Here, we found that simultaneous stimulation of the alpha1 and alpha2 adrenoreceptor restores in adult mice the high rate of transport for the lysosomal enzyme P-GUS that is seen in neonates but lost with development. Beta adrenergics, other monoamines, and acetylcholine did not restore this transport. A high dose (500 microg/mouse of clonidine, a strong alpha2 and weak alpha1 agonist, was able to act as monotherapy in the stimulation of P-GUS transport. Neither use of alpha1 plus alpha2 agonists nor the high dose clonidine disrupted the BBB to albumin. In situ brain perfusion and immunohistochemistry studies indicated that adrengerics act on transporters already at the luminal surface of brain endothelial cells. These results show that adrenergic stimulation, including monotherapy with clonidine, could be key for CNS enzyme replacement therapy.

  7. Substrate deprivation: a new therapeutic approach for the glycosphingolipid lysosomal storage diseases.

    Science.gov (United States)

    Platt, F M; Butters, T D

    2000-02-01

    The glycosphingolipid (GSL) lysosomal storage diseases are a family of human metabolic diseases that, in their severest forms, cause death in early infancy, as a result of progressive neurodegeneration. They are caused by mutations in the genes encoding the glycohydrolases or the activator proteins that catabolise GSLs within lysosomes. In these diseases the GSL substrate of the defective enzyme accumulates in the lysosome, where it is stored and leads to cellular dysfunction and disease. The therapeutic options for treating these diseases are relatively limited; in fact, there are currently no available therapies for most of these disorders. The problem is further compounded by difficulties in delivering therapeutic agents to the central nervous system, which is where the pathology is frequently manifested. To date, research effort has mainly focused on strategies for augmenting enzyme concentrations to compensate for the underlying defect. These strategies include bone-marrow transplantation, enzyme-replacement therapy and gene therapy. Our group has been exploring the alternative strategy of substrate deprivation. This approach aims to balance the rate of GSL synthesis with the impaired rate of GSL breakdown. Studies using an asymptomatic mouse model of Tay-Sachs disease have shown that substrate deprivation prevents GSL storage. In a severe neurodegenerative mouse model of Sandhoff disease, substrate deprivation delayed the onset of symptoms and disease progression, and significantly increased life expectancy. The implications of this research for human therapy have been discussed.

  8. Wolman's disease and cholesteryl ester storage disorder: the phenotypic spectrum of lysosomal acid lipase deficiency.

    Science.gov (United States)

    Pericleous, Marinos; Kelly, Claire; Wang, Tim; Livingstone, Callum; Ala, Aftab

    2017-09-01

    Lysosomal acid lipase deficiency is a rare, autosomal recessive condition caused by mutations in the gene encoding lysosomal acid lipase (LIPA) that result in reduced or absent activity of this essential enzyme. The severity of the resulting disease depends on the nature of the underlying mutation and magnitude of its effect on enzymatic function. Wolman's disease is a severe disorder that presents during infancy, resulting in failure to thrive, hepatomegaly, and hepatic failure, and an average life expectancy of less than 4 months. Cholesteryl ester storage disorder arises later in life and is less severe, although the two diseases share many common features, including dyslipidaemia and transaminitis. The prevalence of these diseases has been estimated at one in 40 000 to 300 000, but many cases are undiagnosed and unreported, and awareness among clinicians is low. Lysosomal acid lipase deficiency-which can be diagnosed using dry blood spot testing-is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), hereditary dyslipidaemia, or cryptogenic cirrhosis. There are no formal guidelines for treatment of these patients, and treatment options are limited. In this Review we appraise the existing literature on Wolman's disease and cholesteryl ester storage disease, and discuss available treatments, including enzyme replacement therapy, oral lipid-lowering therapy, stem-cell transplantation, and liver transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. The influence of lysosomal stability of silver nanomaterials on their toxicity to human cells.

    Science.gov (United States)

    Setyawati, Magdiel Inggrid; Yuan, Xun; Xie, Jianping; Leong, David Tai

    2014-08-01

    How silver nanomaterials (Ag NMs) could induce toxicity has been debated heatedly by many researchers. We utilized Ag nanoclusters (Ag NCs) with the same size and ligand protection but different core surface speciation. Ag(+)-rich NCs (Ag(+)-R NCs) and their counterpart, the reduced Ag(0)-rich NCs (Ag(0)-R NCs) are synthesized to represent possible dichotomous stages in silver nanomaterial degradation process. Here we show Ag(0)-R NCs induce higher cellular toxicity when compared to Ag(+)-R NCs. This cellular toxicity is brought about via the modulation of reactive oxygen species (ROS) in cells as a result of the more rapid release of Ag species from Ag(0)-R NCs and subsequent oxidation into Ag(+) in the lysosomal compartment. The weaker Ag(0)-R bond greatly potentiated the release of Ag species in the acidic and enzymatic processes within the lysosomes. Since lysosomes are absent in bacteria, increasing silver nanomaterials stability may lower toxicity in mammalian cells whilst not reducing their efficacy to fight bacteria; this redesign can result in a safer silver nanomaterial. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Acid sphingomyelinase modulates the autophagic process by controlling lysosomal biogenesis in Alzheimer's disease.

    Science.gov (United States)

    Lee, Jong Kil; Jin, Hee Kyung; Park, Min Hee; Kim, Bo-ra; Lee, Phil Hyu; Nakauchi, Hiromitsu; Carter, Janet E; He, Xingxuan; Schuchman, Edward H; Bae, Jae-sung

    2014-07-28

    In Alzheimer's disease (AD), abnormal sphingolipid metabolism has been reported, although the pathogenic consequences of these changes have not been fully characterized. We show that acid sphingomyelinase (ASM) is increased in fibroblasts, brain, and/or plasma from patients with AD and in AD mice, leading to defective autophagic degradation due to lysosomal depletion. Partial genetic inhibition of ASM (ASM(+/-)) in a mouse model of familial AD (FAD; amyloid precursor protein [APP]/presenilin 1 [PS1]) ameliorated the autophagocytic defect by restoring lysosomal biogenesis, resulting in improved AD clinical and pathological findings, including reduction of amyloid-β (Aβ) deposition and improvement of memory impairment. Similar effects were noted after pharmacologic restoration of ASM to the normal range in APP/PS1 mice. Autophagic dysfunction in neurons derived from FAD patient induced pluripotent stem cells (iPSCs) was restored by partial ASM inhibition. Overall, these results reveal a novel mechanism of ASM pathogenesis in AD that leads to defective autophagy due to impaired lysosomal biogenesis and suggests that partial ASM inhibition is a potential new therapeutic intervention for the disease. © 2014 Lee et al.

  12. Investigation of endosome and lysosome biology by ultra pH-sensitive nanoprobes.

    Science.gov (United States)

    Wang, Chensu; Zhao, Tian; Li, Yang; Huang, Gang; White, Michael A; Gao, Jinming

    2017-04-01

    Endosomes and lysosomes play a critical role in various aspects of cell physiology such as nutrient sensing, receptor recycling, protein/lipid catabolism, and cell death. In drug delivery, endosomal release of therapeutic payloads from nanocarriers is also important in achieving efficient delivery of drugs to reach their intracellular targets. Recently, we invented a library of ultra pH-sensitive (UPS) nanoprobes with exquisite fluorescence response to subtle pH changes. The UPS nanoprobes also displayed strong pH-specific buffer effect over small molecular bases with broad pH responses (e.g., chloroquine and NH 4 Cl). Tunable pH transitions from 7.4 to 4.0 of UPS nanoprobes cover the entire physiological pH of endocytic organelles (e.g., early and late endosomes) and lysosomes. These unique physico-chemical properties of UPS nanoprobes allowed a 'detection and perturbation' strategy for the investigation of luminal pH in cell signaling and metabolism, which introduces a nanotechnology-enabled paradigm for the biological studies of endosomes and lysosomes. Published by Elsevier B.V.

  13. Lysosomal Cathepsin A Plays Significant Role In The Processing Of Endogenous Bioactive Peptides

    Directory of Open Access Journals (Sweden)

    Zehra Timur

    2016-10-01

    Full Text Available Lysosomal serine carboxypeptidase Cathepsin A (CTSA is a multifunctional enzyme with distinct protective and catalytic function. CTSA that is present in the lysosomal multienzyme complex facilitates correct lysosomal routing, stability and activation of betagalactosidase and alpha-neuraminidase. In addition, CTSA plays a role in the inactivation of bioactive peptides including bradykinin, substances P, oxytocin, angiotensin I and endothelin-I by cleavage of one or two amino acid(s from the C-terminal ends. In this study, we aimed to elucidate the regulatory role of CTSA on bioactive peptides in a knock-in mouse model of CTSAS190A. We evaluated the levels of bradykinin, substances P, oxytocin, angiotensin I and endothelin-I in the kidney, liver, lung, brain and serum of the CTSAS190A mouse model at three- and six-months of age. Our results suggest that CTSA selectively contributes to the processing of bioactive peptides in different tissues of CTSAS190A mice compared to those of age-matched wild-type mice.

  14. Both K63 and K48 ubiquitin linkages signal lysosomal degradation of the LDL receptor.

    Science.gov (United States)

    Zhang, Li; Xu, Ming; Scotti, Elena; Chen, Zhijian J; Tontonoz, Peter

    2013-05-01

    Linkage-specific ubiquitination often leads to distinct cellular events. It has been difficult to establish definitively the requirement for a particular linkage in mammalian degradation pathways due to the inability to deplete endogenous ubiquitin while maintaining cell viability. The E3 ubiquitin ligase inducible degrader of the LDL receptor (IDOL) targets the low density lipoprotein receptor (LDLR) for degradation. The nature of the linkages employed to signal lysosomal degradation of the LDLR, and to signal proteasomal autodegradation of IDOL, have not been determined. We used an inducible RNAi strategy to replace endogenous ubiquitin with mutants lacking K48 or K63. We found that IDOL catalyzes the transfer of ubiquitin chains to itself and to the LDLR that do not contain exclusively K48 or K63 linkages. Thus, LDLR can be targeted to the lysosome by either K48 or K63 linkages. We further demonstrate that although both ubiquitin conjugating enzyme E2 (UBE2)Ds and UBE2N/V1 can catalyze LDLR ubiquitination in a cell-free system, UBE2Ds appear to be the major E2 enzymes employed by IDOL in cells, consistent with their ability to catalyze both K48 and K63 linkages. The results reveal mechanistic insight into the posttranscriptional control of lipoprotein uptake and provide a test of the requirement of linkage-specific ubiquitination for specific lysosomal and proteasomal degradation pathways in mammalian cells.

  15. 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.

  16. SRT1720 induces lysosomal-dependent cell death of breast cancer cells.

    Science.gov (United States)

    Lahusen, Tyler J; Deng, Chu-Xia

    2015-01-01

    SRT1720 is an activator of SIRT1, a NAD(+)-dependent protein and histone deacetylase that plays an important role in numerous biologic processes. Several studies have illustrated that SRT1720 treatment could improve metabolic conditions in mouse models and in a study in cancer SRT1720 caused increased apoptosis of myeloma cells. However, the effect of SRT1720 on cancer may be complex, as some recent studies have demonstrated that SRT1720 may not directly activate SIRT1 and another study showed that SRT1720 treatment could promote lung metastasis. To further investigate the role of SRT1720 in breast cancer, we treated SIRT1 knockdown and control breast cancer cell lines with SRT1720 both in vitro and in vivo. We showed that SRT1720 more effectively decreased the viability of basal-type MDA-MB-231 and BT20 cells as compared with luminal-type MCF-7 breast cancer cells or nontumorigenic MCF-10A cells. We demonstrated that SRT1720 induced lysosomal membrane permeabilization and necrosis, which could be blocked by lysosomal inhibitors. In contrast, SRT1720-induced cell death occurred in vitro irrespective of SIRT1 status, whereas in nude mice, SRT1720 exhibited a more profound effect in inhibiting the growth of allograft tumors of SIRT1 proficient cells as compared with tumors of SIRT1-deficient cells. Thus, SRT1720 causes lysosomal-dependent necrosis and may be used as a therapeutic agent for breast cancer treatment. ©2014 American Association for Cancer Research.

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

    Directory of Open Access Journals (Sweden)

    Da Li

    2013-12-01

    Full Text Available 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 Parkinson’s disease (PD. However, it remains unclear what roles dynein plays in α-synuclein degradation. Our study demonstrated a decrease of dynein expression in neurotoxin-induced PD models in vitro and in vivo, accompanied by an increase of α-synuclein protein level. Dynein down-regulation induced by siRNA resulted in a prolonged half-life of α-synuclein and its over-accumulation in A53T overexpressing PC12 cells. Dynein knockdown also prompted the increase of microtubule-associated protein 1 light chain 3 (LC3-II and sequestosome 1 (SQSTM1, p62 expression, and the accumulation of autophagic vacuoles. Moreover, dynein suppression impaired the autophagosome fusion with lysosome. In summary, our findings indicate that dynein is critical for the clearance of aberrant α-synuclein via autophagosome-lysosome pathway.

  18. 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

  19. 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

    2016-08-05

    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. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    Directory of Open Access Journals (Sweden)

    Muhammet Akyuz

    2013-10-01

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

  1. Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease

    DEFF Research Database (Denmark)

    Møller, Christian H; Penninga, Luit; Wetterslev, Jørn

    2012-01-01

    Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.......Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear....

  2. Polyketide synthase (PKS) reduces fusion of Legionella pneumophila-containing vacuoles with lysosomes and contributes to bacterial competitiveness during infection.

    Science.gov (United States)

    Shevchuk, Olga; Pägelow, Dennis; Rasch, Janine; Döhrmann, Simon; Günther, Gabriele; Hoppe, Julia; Ünal, Can Murat; Bronietzki, Marc; Gutierrez, Maximiliano Gabriel; Steinert, Michael

    2014-11-01

    L. pneumophila-containing vacuoles (LCVs) exclude endocytic and lysosomal markers in human macrophages and protozoa. We screened a L. pneumophila mini-Tn10 transposon library for mutants, which fail to inhibit the fusion of LCVs with lysosomes by loading of the lysosomal compartment with colloidal iron dextran, mechanical lysis of infected host cells, and magnetic isolation of LCVs that have fused with lysosomes. In silico analysis of the mutated genes, D. discoideum plaque assays and infection assays in protozoa and U937 macrophage-like cells identified well established as well as novel putative L. pneumophila virulence factors. Promising candidates were further analyzed for their co-localization with lysosomes in host cells using fluorescence microscopy. This approach corroborated that the O-methyltransferase, PilY1, TPR-containing protein and polyketide synthase (PKS) of L. pneumophila interfere with lysosomal degradation. Competitive infections in protozoa and macrophages revealed that the identified PKS contributes to the biological fitness of pneumophila strains and may explain their prevalence in the epidemiology of Legionnaires' disease. Copyright © 2014 Elsevier GmbH. All rights reserved.

  3. 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.

  4. The Increased Activity of Liver Lysosomal Lipase in Nonalcoholic Fatty Liver Disease Contributes to the Development of Hepatic Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Monika Cahova

    2012-01-01

    Full Text Available We tested the hypothesis that TAG accumulation in the liver induced by short-term high-fat diet (HFD in rats leads to the dysregulation of endogenous TAG degradation by lysosomal lipase (LIPA via lysosomal pathway and is causally linked with the onset of hepatic insulin resistance. We found that LIPA could be translocated between qualitatively different depots (light and dense lysosomes. In contrast to dense lysosomal fraction, LIPA associated with light lysosomes exhibits high activity on both intracellular TAG and exogenous substrate and prandial- or diet-dependent regulation. On standard diet, LIPA activity was upregulated in fasted and downregulated in fed animals. In the HFD group, we demonstrated an increased TAG content, elevated LIPA activity, enhanced production of diacylglycerol, and the abolishment of prandial-dependent LIPA regulation in light lysosomal fraction. The impairment of insulin signalling and increased activation of PKCε was found in liver of HFD-fed animals. Lipolysis of intracellular TAG, mediated by LIPA, is increased in steatosis probably due to the enhanced formation of phagolysosomes. Consequent overproduction of diacylglycerol may represent the causal link between HFD-induced hepatic TAG accumulation and hepatic insulin resistance via PKCε activation.

  5. Atorvastatin inhibits the apoptosis of human umbilical vein endothelial cells induced by angiotensin II via the lysosomal-mitochondrial axis.

    Science.gov (United States)

    Chang, Ye; Li, Yuan; Ye, Ning; Guo, Xiaofan; Li, Zhao; Sun, Guozhe; Sun, Yingxian

    2016-09-01

    This study was aimed to evaluate lysosomes-mitochondria cross-signaling in angiotensin II (Ang II)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and whether atorvastatin played a protective role via lysosomal-mitochondrial axis. Apoptosis was detected by flow cytometry, Hoechst 33342 and AO/EB assay. The temporal relationship of lysosomal and mitochondrial permeabilization was established. Activity of Cathepsin D (CTSD) was suppressed by pharmacological and genetic approaches. Proteins production were measured by western blotting. Our study showed that Ang II could induce the apoptosis of HUVECs in a dose-depended and time-depended manner. Exposure to 1 μM Ang II for 24 h resulted in mitochondrial depolarization, cytochrome c release, and increased ROS production. Lysosomal permeabilization and CTSD redistribution into the cytoplasm occurred several hours prior to mitochondrial dysfunction. These effects were all suppressed by atorvastatin. Either pharmacological or genetic inhibition of CTSD preserved mitochondrial function and decreased apoptosis in HUVECs. Most importantly, we found that the protective effect of atorvastatin was significantly greater than pharmacological or genetic inhibition of CTSD. Finally, overexpression of CTSD without exposure to Ang II had no effect on mitochondrial function and apoptosis. Our data strongly suggested that Ang II induced apoptosis through the lysosomal-mitochondrial axis in HUVECs. Furthermore, atorvastatin played an important role in the regulation of lysosomes and mitochondria stability, resulting in an antagonistic role against Ang II on HUVECs.

  6. Intraoperative echocardiographic imaging of coronary arteries and graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass.

    Science.gov (United States)

    Suematsu, Y; Takamoto, S; Ohtsuka, T

    2001-12-01

    No accepted approach exists for the intraoperative evaluation of the quality of coronary arteries and the technical adequacy of graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass. We assessed the accuracy of high-frequency epicardial echocardiography and power Doppler imaging in evaluating coronary arteries during coronary artery bypass grafting without cardiopulmonary bypass. To validate measurements of coronary arteries and graft anastomoses by high-frequency epicardial echocardiography and power Doppler imaging, we compared luminal diameters determined by these methods with diameters determined histologically in a study of off-pump coronary artery bypass grafting in 20 dogs. Technical errors were deliberately created in 10 grafts (stenosis group). The results of these animal validation studies showed that the maximum luminal diameters of coronary arteries and graft anastomoses measured by high-frequency epicardial echocardiography (HEE) and power Doppler imaging (PDI) correlated well with the histologic measurements: HEE = 1.027 x Histologic measurements + 0.005 (P anastomoses were examined intraoperatively by high-frequency epicardial echocardiography and power Doppler imaging, and luminal diameters determined by power Doppler imaging were compared with those determined by postoperative coronary angiography. The results demonstrated that graft anastomosis by power Doppler imaging correlated well with the angiographic measurements: PDI = 1.018 x Angiographic measurements - 0.106 (P anastomoses and can detect technical errors and inadequacies during coronary artery bypass grafting without cardiopulmonary bypass.

  7. Modulating lysosomal function through lysosome membrane permeabilization or autophagy suppression restores sensitivity to cisplatin in refractory non-small-cell lung cancer cells

    Science.gov (United States)

    Circu, Magdalena; Cardelli, James; Barr, Martin; O’Byrne, Kenneth; Mills, Glenn

    2017-01-01

    Lung cancer is the leading cause of cancer-related deaths. Most patients develop resistance to platinum within several months of treatment. We investigated whether triggering lysosomal membrane permeabilization (LMP) or suppressing autophagy can restore cisplatin susceptibility in lung cancer with acquired chemoresistance. Cisplatin IC50 in A549Pt (parental) and A549cisR (cisplatin resistant) cells was 13 μM and 47 μM, respectively. Following cisplatin exposure, A549cisR cells failed to elicit an apoptotic response. This was manifested by diminished Annexin–V staining, caspase 3 and 9, BAX and BAK activation in resistant but not in parental cells. Chloroquine preferentially promoted LMP in A549cisR cells, revealed by leakage of FITC-dextran into the cytosol as detected by immunofluorescence microscopy. This was confirmed by increased cytosolic cathepsin D signal on Immunoblot. Cell viability of cisplatin-treated A549cisR cells was decreased when co-treated with chloroquine, corresponding to a combination index below 0.8, suggesting synergism between the two drugs. Notably, chloroquine activated the mitochondrial cell death pathway as indicated by increase in caspase 9 activity. Interestingly, inhibition of lysosomal proteases using E64 conferred cytoprotection against cisplatin and chloroquine co-treatment, suggesting that chloroquine-induced cell death occurred in a cathepsin-mediated mechanism. Likewise, blockage of caspases partially rescued A549cisR cells against the cytotoxicity of cisplatin and chloroquine combination. Cisplatin promoted a dose-dependent autophagic flux induction preferentially in A549cisR cells, as evidenced by a surge in LC3-II/α-tubulin following pre-treatment with E64 and increase in p62 degradation. Compared to untreated cells, cisplatin induced an increase in cyto-ID-loaded autophagosomes in A549cisR cells that was further amplified by chloroquine, pointing toward autophagic flux activation by cisplatin. Interestingly, this effect

  8. Giant Cellular Vacuoles Induced by Rare Earth Oxide Nanoparticles are Abnormally Enlarged Endo/Lysosomes and Promote mTOR-Dependent TFEB Nucleus Translocation.

    Science.gov (United States)

    Lin, Jun; Shi, Shan-Shan; Zhang, Ji-Qian; Zhang, Yun-Jiao; Zhang, Li; Liu, Yun; Jin, Pei-Pei; Wei, Peng-Fei; Shi, Rong-Hua; Zhou, Wei; Wen, Long-Ping

    2016-11-01

    Many nanomaterials are reported to disrupt lysosomal function and homeostasis, but how cells sense and then respond to nanomaterial-elicited lysosome stress is poorly understood. Nucleus translocation of transcription factor EB (TFEB) plays critical roles in lysosome biogenesis following lysosome stress induced by starvation. The authors previously reported massive cellular vacuolization, along with autophagy induction, in cells treated with rare earth oxide (REO) nanoparticles. Here, the authors identify these giant cellular vacuoles as abnormally enlarged and alkalinized endo/lysosomes whose formation is dependent on macropinocytosis. This vacuolization causes deactivation of mammalian target of rapamycin (mTOR), a TFEB-interacting kinase that resides on the lysosome membrane. Subsequently, TFEB is dephosphorylated at serine 142 and translocated into cell nucleus. This nucleus translocation of TFEB is observed only in vacuolated cells and it is critical for maintaining lysosome homeostasis after REO nanoparticle treatment, as knock-down of TFEB gene significantly compromises lysosome function and enhances cell death in nanoparticle-treated cells. Our results reveal that cellular vacuolization, which is commonly observed in cells treated with REOs and other nanomaterials, represents a condition of profound lysosome stress, and cells sense and respond to this stress by facilitating mTOR-dependent TFEB nucleus translocation in an effort to restore lysosome homeostasis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Energy Technology Data Exchange (ETDEWEB)

    Laurence R. Zirker; James E. Francfort

    2003-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-31

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

  11. Changes in the vessels following aorto-coronary bypass operation

    International Nuclear Information System (INIS)

    Goebel, N.; Pfluger, N.; Speiser, K.; Turina, M.; Rothlin, M.; Zurich Univ.; Zurich Univ.

    1983-01-01

    In a prospective study (238 men, mean age 53 years) the changes of the native vessels were studied 3 months after a-c-bypass operation and 5 months after preop. angiography. Progression was defined as increase of stenoses of at least 20% or new total occlusion. Progression was significantly more frequent in vessels with than without bypass and was located proximally to the anastomoses in most cases, less frequently at the anastomoses and very rarely distally to the anastomoses. Proximal progression was significantly more frequent with patent than with occluded bypasses. Stenoses at the anastomoses were significantly more frequent with occluded than with patent bypasses. Stenoses of higher degrees hat a stonger tendency for progression than slighter stenoses. Regression was rare and nearly always caused by surgery. (orig.) [de

  12. 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...

  13. Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  14. 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 matche...

  15. Transfusion requirements in elective cardiopulmonary bypass surgery patients

    DEFF Research Database (Denmark)

    Sivapalan, Praleene; Bäck, Anne Caroline; Ostrowski, Sisse Rye

    2017-01-01

    Managing haemostasis in patients undergoing cardiopulmonary bypass (CPB) surgery remains a challenge. There is no established laboratory test to predict transfusion requirements in cardiac surgery. We investigated whether preoperative Thromboelastography (TEG) with Platelet Mapping Assay (PMA......) or Multiple Electrode Aggrometry (MEA) could predict transfusion requirements in patients undergoing elective coronary artery bypass grafting (CABG) or combined CABG with aortic or mitral valve replacement. We prospectively investigated 199 patients undergoing elective CABG or combined procedures. PMA and MEA...

  16. Crohn’s disease after gastric bypass surgery

    OpenAIRE

    Janczewska, Izabella; Nekzada, Qayium; Kapraali, Marjo

    2011-01-01

    Bariatric surgery for the treatment of severe obesity has increased dramatically in recent years in the USA and parts of Western Europe. The most commonly used technique is the Roux-en Y gastric bypass (RYGBP). Several nutritional and gastrointestinal complications after bariatric surgery have been described during the last 10 years. The authors present two patients with diarrhoea and malnutrition; one after RYGBP and the other after jejunoileal bypass surgery. These patients were subsequentl...

  17. Combined coronary artery bypass surgery and abdominal aortic aneurysm repair.

    OpenAIRE

    Black, J J; Desai, J B

    1995-01-01

    The proper management of patients with asymptomatic abdominal aortic aneurysms and significant coexistent coronary artery disease is still debatable. The most common approach has been to perform the coronary artery bypass surgery some weeks before the abdominal aortic aneurysm repair in the hope of reducing the cardiac morbidity and mortality. We report our initial experience of three consecutive elective cases where the coronary artery bypass surgery and the abdominal aortic aneurysm repair ...

  18. Robotically assisted totally endoscopic coronary artery bypass surgery

    OpenAIRE

    Canale, Leonardo Secchin; Mick, Stephanie; Mihaljevic, Tomislav; Nair, Ravi; Bonatti, Johannes

    2013-01-01

    Robotically assisted totally endoscopic coronary artery bypass surgery has emerged as a feasible and efficient alternative to conventional full sternotomy coronary artery bypass graft surgery in selected patients. This minimally invasive approach using the daVinci robotic system allows fine intrathoracic maneuvers and excellent view of the coronary arteries. Both on-pump and off-pump operations can be performed to treat single and multivessel disease. Hybrid approaches have the potential of o...

  19. Cardiopulmonary bypass: development of John Gibbon's heart-lung machine

    OpenAIRE

    Passaroni, Andréia Cristina; Silva, Marcos Augusto de Moraes; Yoshida, Winston Bonetti

    2015-01-01

    AbstractObjective:To provide a brief review of the development of cardiopulmonary bypass.Methods:A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation.Results:The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from vari...

  20. Predictive factors for better bypass patency and limb salvage after prosthetic above-knee bypass reconstruction.

    Science.gov (United States)

    Klingelhoefer, Eric; Bergert, Hendrik; Kersting, Stephan; Ludwig, Stefan; Weiss, Norbert; Schönleben, Frank; Grützmann, Robert; Gäbel, Gabor

    2016-08-01

    Peripheral arterial disease (PAD) is one of the most underestimated diseases because of its high prevalence and unfavorable prognosis. Many PAD patients without suitable autologous veins or options for endovascular treatment receive prosthetic above-knee femoropopliteal bypass (PAKB). Until now predictors of prosthetic bypass failure and of increased amputation risk remain indistinct. This study aimed to identify predictive factors associated with better bypass patency and limb salvage to achieve a more favorable outcome after PAKB reconstruction. Pre-, intra-, and postoperative data of 244 PAKB procedures performed at a German university medical center were collected and analyzed using univariate and multivariate methods. To our knowledge this 12-year experience is the largest retrospective study to identify predictors for patency and limb salvage after PAKB reconstruction. Of the PAD patients 94% (229/244) were followed for an average of 34.9 months. Patient cohorts characteristics were: mean age, 66.1 years, 181 men (74%), claudication (64%), rest pain (16%), ischemic lesions (20%), arterial hypertension (92%), smoking (79%), hyperlipidemia (65%) and type 2 diabetes (43%). Cumulative primary 1- and 3-year graft patency rates were 60.8% and 50.7%, respectively, and cumulative 1- and 3-year limb salvage rates were 89.3% and 86.1%, respectively. One hundred seven bypasses (43.9%) failed, 26 patients (10.7%) required a major and seven patients (2.9%) required a minor amputation. Overall survival rates of PAD patients after 1- and 3-years were 94.4% and 82.9%, respectively. Subjective symptom improvement was found to be the most important prognostic follow-up factor for graft patency and limb salvage. Patients with recurrent symptoms in the follow-up had an increased risk of emerging bypass failure compared with patients with subjective symptom improvement (patency at 1 year: 40.8% vs 100% and at 3 years: 26% vs 100%; P limb salvage at 1 year: 100% vs 79% and

  1. Cerebroprotective effect of piracetam in patients undergoing coronary bypass burgery.

    Science.gov (United States)

    Holinski, Sebastian; Claus, Benjamin; Alaaraj, Nour; Dohmen, Pascal Maria; Kirilova, Kremena; Neumann, Konrad; Uebelhack, Ralf; Konertz, Wolfgang

    2008-11-01

    Reduction of cognitive function is a possible side effect after cardiac surgery using cardiopulmonary bypass. We investigated the cerebroprotective effect of piracetam on cognitive performance in patients undergoing coronary artery bypass surgery under cardiopulmonary bypass. Patients scheduled for elective, primary and isolated coronary bypass surgery were randomised either to piracetam or placebo group. The study was performed in a double blind fashion. Patients received either 12 g piracetam or placebo at the beginning of the operation. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on the third postoperative day. To assess the overall cognitive function and the degree of cognitive decline across all tests after surgery we combined the six test-scores by principal component analysis. A total number of 120 patients were enrolled into the study. Preoperative overall cognitive function were not significantly different between the groups. The postoperative combined score of the neuropsychological tests showed a deterioration of cognitive function in both groups (placebo-pre: -0.06+/-0.99 vs placebo-post: -1.38+/-1.11; ppiracetam-pre: 0.06+/-1.02 vs piracetam-post: -0.65+/-0.93; ppiracetam patients performed significantly better compared to the placebo patients after the operation and had a less decline of overall cognitive function (pPiracetam has a cerebroprotective effect in patients undergoing coronary artery bypass surgery with the use of cardiopulmonary bypass. It reduces an early postoperative substantial decline of neuropsychological abilities.

  2. Cardiac compression of lung lower lobes after coronary artery bypass graft with cardiopulmonary bypass.

    Directory of Open Access Journals (Sweden)

    Flávio H Neves

    Full Text Available BACKGROUND: Atelectasis is a major cause of hypoxemia after coronary artery bypass grafting (CABG and is commonly ascribed to general anesthesia, high inspiratory oxygen concentration and cardiopulmonary bypass (CPB. The objective of this study was to evaluate the role of heart-induced pulmonary compression after CABG with CPB. METHODS: Seventeen patients without pre-operative cardiac failure who were scheduled for coronary artery bypass graft underwent pre- and postoperative thoracic computed tomography. The cardiac mass, the pressure exerted on the lungs by the right and left heart and the fraction of collapsed lower lobe segments below and outside of the heart limits were evaluated on a computed tomography section 1 cm above the diaphragmatic cupola. RESULTS: In the postoperative period, cardiac mass increased by 32% (117±31 g versus 155±35 g, p<0.001, leading to an increase in the pressure that was exerted on the lungs by the right (2.2±0.6 g.cm(-2 versus 3.2±1.2 g.cm(-2, p<0.05 and left heart (2.4±0.7 g.cm(-2 versus 4.2±1.8 g.cm(-2, p<0.001. The proportion of collapsed lung segments beneath the heart markedly increased [from 6.7% to 32.9% on the right side (p<0.001 and from 6.2% to 29% on the left side (p<0.001], whereas the proportion of collapsed lung segments outside of the heart limits slightly increased [from 0.7% to 10.8% on the right side (p<0.001 and from 1.5% to 12.6% on the left side (p<0.001]. CONCLUSION: The pressure that is exerted by the heart on the lungs increased postoperatively and contributed to the collapse of subjacent pulmonary segments.

  3. 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.

  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. Right atrial bypass model in the dog.

    Science.gov (United States)

    Breen, P H; Isserles, S A

    1995-02-01

    In gas exchange studies addressing the storage and transport of CO2 in dogs, a model in which cardiac output (QT) can be precisely controlled and measured would be beneficial. We identified problems with described extracorporeal circuits and implemented right atrial bypass (RAB) in dogs. In 6 anesthetized (chloralose and urethane), heparinized dogs (mean +/- SD, 24 +/- 4 kg) with open thorax, cannulas were inserted in both vena cavas to drain venous blood return to a reservoir (anaerobic bag or bubble oxygenator). A roller pump then drove blood through a heat exchanger back to the right atrial appendage. After 1.8 +/- 1.4 hour of RAB, physiologic variables remained within reference limits for dogs (QT, 1.5 +/- 0.3 L/min; blood pressure, 92 +/- 25 mm of Hg; arterial PCO2, 35 +/- 4 mm of Hg; PO2, 513 +/- 39 mm of Hg; pH, 7.39 +/- 0.08; and tissue CO2 production, 126 +/- 56 ml/min). To permit study of gas exchange, venous return (and thus, QT) and venous PCO2 and PO2 could be accurately regulated and measured over a wide range. Maintenance of native pulsatile lung perfusion and cardiogenic oscillations minimizes mismatching of pulmonary ventilation and perfusion and facilitates studies addressing pulmonary gas exchange. This RAB model is designed so that investigators can establish the preparation in a few hours.

  6. 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.

  7. Membrane Cholesterol Removal Changes Mechanical Properties of Cells and Induces Secretion of a Specific Pool of Lysosomes

    Science.gov (United States)

    Roma, Paula Magda S.; Alves, Ana Paula; Rocha, Carolina D.; Valverde, Thalita M.; Aguiar, Pedro Henrique N.; Almeida, Fernando P.; Guimarães, Allan J.; Guatimosim, Cristina; Silva, Aristóbolo M.; Fernandes, Maria C.; Andrews, Norma W.; Viana, Nathan B.; Mesquita, Oscar N.; Agero, Ubirajara; Andrade, Luciana O.

    2013-01-01

    In a previous study we had shown that membrane cholesterol removal induced unregulated lysosomal exocytosis events leading to the depletion of lysosomes located at cell periphery. However, the mechanism by which cholesterol triggered these exocytic events had not been uncovered. In this study we investigated the importance of cholesterol in controlling mechanical properties of cells and its connection with lysosomal exocytosis. Tether extraction with optical tweezers and defocusing microscopy were used to assess cell dynamics in mouse fibroblasts. These assays showed that bending modulus and surface tension increased when cholesterol was extracted from fibroblasts plasma membrane upon incubation with MβCD, and that the membrane-cytoskeleton relaxation time increased at the beginning of MβCD treatment and decreased at the end. We also showed for the first time that the amplitude of membrane-cytoskeleton fluctuation decreased during cholesterol sequestration, showing that these cells become stiffer. These changes in membrane dynamics involved not only rearrangement of the actin cytoskeleton, but also de novo actin polymerization and stress fiber formation through Rho activation. We found that these mechanical changes observed after cholesterol sequestration were involved in triggering lysosomal exocytosis. Exocytosis occurred even in the absence of the lysosomal calcium sensor synaptotagmin VII, and was associated with actin polymerization induced by MβCD. Notably, exocytosis triggered by cholesterol removal led to the secretion of a unique population of lysosomes, different from the pool mobilized by actin depolymerizing drugs such as Latrunculin-A. These data support the existence of at least two different pools of lysosomes with different exocytosis dynamics, one of which is directly mobilized for plasma membrane fusion after cholesterol removal. PMID:24376622

  8. 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

    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...... endocytosis functioned, however, normally in these cells. Both HeLa and MCF-7 cells appeared to express similar levels of the KIF5B isoform but the death phenotype was weaker in KIF5B-depleted MCF-7 cells. Surprisingly, KIF5B depletion inhibited the rapamycin-induced accumulation of autophagosomes in MCF-7......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...

  9. Multi-slice spiral CT of aortocoronary grafts and internal mammary artery bypasses: Assessment of bypasses and their anastomoses

    International Nuclear Information System (INIS)

    Froehner, S.; Wagner, M.; Schmitt, R.; Christopoulos, G.; Coblenz, G.; Brunn, J.; Mueller, M.; Kerber, S.; Urbanski, P.

    2002-01-01

    Objective: To assess aortocoronary grafts and internal mammary artery bypasses by means of EKG-triggered contrast-enhanced multi-slice spiral CT, and to evaluate the diagnostic accuracy of this new imaging modality. Material and methods: 59 patients with up to 5 aortocoronary grafts and/or internal mammary artery bypasses per patient were examined with regard to bypass morphology, the free passage, and the proximal as well as the distal anastomoses using multi-slice computed tomography. Axial source images were calculated by means of retrospective triggering at different diastolic delay times, and were postprocessed in several planes with the multiplanar volume reconstruction (MPVR) software. Results: On the pre-condition that data sets were acquired at sinus rhythm and at a heart rate lower than 65/min, aortocoronary grafts and internal mammary artery bypasses could be depicted in adequate diagnostic quality in about 80% of all cases with contrast-enhanced multi-slice spiral CT. Both, the free passage of the bypasses as well as the morphology of the proximal anastomoses were sufficiently assessed with multiplanar volume reconstruction (MPVR), whereas the distal anastomoses couldn't be depicted sufficiently in 20% of all cases. Conclusion: As a non-invasive method, contrast-enhanced and ECG-triggered multi-slice spiral computed tomography has gained diagnostic potential for the accurate visualization of aortocoronary grafts and the internal mammary artery bypasses. (orig.) [de

  10. 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

  11. Magnetic Resonance Findings of the Corpus Callosum in Canine and Feline Lysosomal Storage Diseases

    Science.gov (United States)

    Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

    2013-01-01

    Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses. PMID:24386203

  12. Inhibition of substrate synthesis as a strategy for glycolipid lysosomal storage disease therapy.

    Science.gov (United States)

    Platt, F M; Jeyakumar, M; Andersson, U; Priestman, D A; Dwek, R A; Butters, T D; Cox, T M; Lachmann, R H; Hollak, C; Aerts, J M; Van Weely, S; Hrebícek, M; Moyses, C; Gow, I; Elstein, D; Zimran, A

    2001-04-01

    The glycosphingolipid (GSL) lysosomal storage diseases are caused by mutations in the genes encoding the glycohydrolases that catabolize GSLs within lysosomes. In these diseases the substrate for the defective enzyme accumulates in the lysosome and the stored GSL leads to cellular dysfunction and disease. The diseases frequently have a progressive neurodegenerative course. The therapeutic options for treating these diseases are relatively limited, and for the majority there are no effective therapies. The problem is further compounded by difficulties in delivering therapeutic agents to the brain. Most research effort to date has focused on strategies for augmenting enzyme levels to compensate for the underlying defect. These include bone marrow transplantation (BMT), enzyme replacement and gene therapy. An alternative strategy that we have been exploring is substrate deprivation. This approach aims to balance the rate of GSL synthesis with the impaired rate of GSL breakdown. The imino sugar N-butyldeoxynojirimycin (NB-DNJ) inhibits the first step in GSL biosynthesis and has been used to evaluate this approach. Studies in an asymptomatic mouse model of Tay-Sachs disease have shown that substrate deprivation prevents GSL storage in the CNS. In a severe neurodegenerative mouse model of Sandhoff disease, substrate deprivation delayed the onset of symptoms and disease progression and significantly increased life expectancy. Combining NB-DNJ and BMT was found to be synergistic in the Sandhoff mouse model. A clinical trial in type I Gaucher disease has been undertaken and has shown beneficial effects. Efficacy was demonstrated on the basis of significant decreases in liver and spleen volumes, gradual but significant improvement in haematological parameters and disease activity markers, together with diminished GSL biosynthesis and storage as determined by independent biochemical assays. Further trials in type I Gaucher disease are in progress; studies are planned in

  13. 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.

  14. MHC class I endosomal and lysosomal trafficking coincides with exogenous antigen loading in dendritic cells.

    Directory of Open Access Journals (Sweden)

    Genc Basha

    Full Text Available BACKGROUND: Cross-presentation by dendritic cells (DCs is a crucial prerequisite for effective priming of cytotoxic T-cell responses against bacterial, viral and tumor antigens; however, this antigen presentation pathway remains poorly defined. METHODOLOGY/PRINCIPAL FINDINGS: In order to develop a comprehensive understanding of this process, we tested the hypothesis that the internalization of MHC class I molecules (MHC-I from the cell surface is directly involved in cross-presentation pathway and the loading of antigenic peptides. Here we provide the first examination of the internalization of MHC-I in DCs and we demonstrate that the cytoplasmic domain of MHC-I appears to act as an addressin domain to route MHC-I to both endosomal and lysosomal compartments of DCs, where it is demonstrated that loading of peptides derived from exogenously-derived proteins occurs. Furthermore, by chasing MHC-I from the cell surface of normal and transgenic DCs expressing mutant forms of MHC-I, we observe that a tyrosine-based endocytic trafficking motif is required for the constitutive internalization of MHC-I molecules from the cell surface into early endosomes and subsequently deep into lysosomal peptide-loading compartments. Finally, our data support the concept that multiple pathways of peptide loading of cross-presented antigens may exist depending on the chemical nature and size of the antigen requiring processing. CONCLUSIONS/SIGNIFICANCE: We conclude that DCs have 'hijacked' and adapted a common vacuolar/endocytic intracellular trafficking pathway to facilitate MHC I access to the endosomal and lysosomal compartments where antigen processing and loading and antigen cross-presentation takes place.

  15. Combination of Classifiers Identifies Fungal-Specific Activation of Lysosome Genes in Human Monocytes

    Directory of Open Access Journals (Sweden)

    João P. Leonor Fernandes Saraiva

    2017-11-01

    Full Text Available Blood stream infections can be caused by several pathogens such as viruses, fungi and bacteria and can cause severe clinical complications including sepsis. Delivery of appropriate and quick treatment is mandatory. However, it requires a rapid identification of the invading pathogen. The current gold standard for pathogen identification relies on blood cultures and these methods require a long time to gain the needed diagnosis. The use of in situ experiments attempts to identify pathogen specific immune responses but these often lead to heterogeneous biomarkers due to the high variability in methods and materials used. Using gene expression profiles for machine learning is a developing approach to discriminate between types of infection, but also shows a high degree of inconsistency. To produce consistent gene signatures, capable of discriminating fungal from bacterial infection, we have employed Support Vector Machines (SVMs based on Mixed Integer Linear Programming (MILP. Combining classifiers by joint optimization constraining them to the same set of discriminating features increased the consistency of our biomarker list independently of leukocyte-type or experimental setup. Our gene signature showed an enrichment of genes of the lysosome pathway which was not uncovered by the use of independent classifiers. Moreover, our results suggest that the lysosome genes are specifically induced in monocytes. Real time qPCR of the identified lysosome-related genes confirmed the distinct gene expression increase in monocytes during fungal infections. Concluding, our combined classifier approach presented increased consistency and was able to “unmask” signaling pathways of less-present immune cells in the used datasets.

  16. 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.

  17. Matrix protein 2 of influenza A virus blocks autophagosome fusion with lysosomes

    DEFF Research Database (Denmark)

    Gannagé, Monique; Dormann, Dorothee; Albrecht, Randy

    2009-01-01

    demonstrate that influenza A virus inhibits macroautophagy, a cellular process known to be manipulated by diverse pathogens. Influenza A virus infection causes accumulation of autophagosomes by blocking their fusion with lysosomes, and one viral protein, matrix protein 2, is necessary and sufficient...... for this inhibition of autophagosome degradation. Macroautophagy inhibition by matrix protein 2 compromises survival of influenza virus-infected cells but does not influence viral replication. We propose that influenza A virus, which also encodes proapoptotic proteins, is able to determine the death of its host cell...

  18. Determination of frequencies of alleles, associated with the pseudodeficiency of lysosomal hydrolases, in population of Ukraine.

    Science.gov (United States)

    Olkhovych, N V; Gorovenko, N G

    2016-01-01

    The pseudodeficiency of lysosomal hydrolases described as a significant reduction in enzyme activi­ty in vitro in clinically healthy individuals, can lead to diagnostic errors in the process of biochemical analysis of lysosomal storage disease in case of its combination with pathology of another origin. Pseudodeficiency is mostly caused by some non-pathogenic changes in the corresponding gene. These changes lead to the in vitro lability of the enzyme molecule, whereas in vivo the enzyme retains its functional activity. To assess the prevalence of the most common lysosomal hydrolases pseudodeficiency alleles in Ukraine, we have determined the frequency of alleles c.1055A>G and c.* 96A>G in the ARSA gene, substitutions c.739C>T (R247W) and c.745C>T (R249W) in the HEXA gene, c.1726G>A (G576S) and c.2065G>A (E689K) in the GAA gene, c.937G>T (D313Y) in the GLA1 gene and c.898G>A (A300T) in the IDUA gene in a group of 117 healthy individuals from different regions of the country and 14 heterozygous carriers of pathogenic mutations in the HEXA gene (parents of children with confirmed diagnosis of Tay-Sachs disease). The total frequency of haplotypes, associated with arylsulfatase A pseudodeficiency, in healthy people in Ukraine (c.1055G/c.*96G and c.1055G/c.*96A haplotypes) was 10.3%. The frequency of c.739C>T (R247W) allele, associated with hexo­saminidase A pseudodeficiency, among Tay-Sachs carriers from Ukraine was 7.1%. The total frequency of α-glucosidase pseudodeficiency haplotypes in healthy individuals in Ukraine (c.1726A/c.2065A and c.1726G/c.2065A haplotypes) was 2.6%. No person among examined individuals with the substitution c.937G>T (D313Y) in the GLA1 gene and c.898G>A (A300T) in the IDUA gene was found. The differential diagnostics of lysosomal storage diseases requires obligatory determination of the presence of the pseudodeficiency alleles, particularly the ones with high incidence in the total population. Ignoring phenomenon of pseudodeficiency may

  19. Impaired cholesterol esterification in primary brain cultures of the lysosomal cholesterol storage disorder (LCSD) mouse mutant

    International Nuclear Information System (INIS)

    Patel, S.C.; Suresh, S.; Weintroub, H.; Brady, R.O.; Pentchev, P.G.

    1987-01-01

    Esterification of cholesterol was investigated in primary neuroglial cultures obtained from newborn lysosomal cholesterol storage disorder (LCSD) mouse mutants. An impairment in 3 H-oleic acid incorporation into cholesteryl esters was demonstrated in cultures of homozygous LCSD brain. Primary cultures derived from other phenotypically normal pups of the carrier breeders esterified cholesterol at normal levels or at levels which were intermediary between normal and deficient indicating a phenotypic expression of the LCSD heterozygote genotype. These observations on LCSD mutant brain cells indicate that the defect in cholesterol esterification is closely related to the primary genetic defect and is expressed in neuroglial cells in culture

  20. Determination of frequencies of alleles, associated with the pseudodeficiency of lysosomal hydrolases, in population of Ukraine

    Directory of Open Access Journals (Sweden)

    N. V. Olkhovych

    2016-10-01

    Full Text Available The pseudodeficiency of lysosomal hydrolases described as a significant reduction in enzyme activi­ty in vitro in clinically healthy individuals, can lead to diagnostic errors in the process of biochemical analysis of lysosomal storage disease in case of its combination with pathology of another origin. Pseudodeficiency is mostly caused by some non-pathogenic changes in the corresponding gene. These changes lead to the in vitro lability of the enzyme molecule, whereas in vivo the enzyme retains its functional activity. To assess the prevalence of the most common lysosomal hydrolases pseudodeficiency alleles in Ukraine, we have determined the frequency of alleles c.1055A>G and c.* 96A>G in the ARSA gene, substitutions c.739C>T (R247W and c.745C>T (R249W in the HEXA gene, c.1726G>A (G576S and c.2065G>A (E689K in the GAA gene, c.937G>T (D313Y in the GLA1 gene and c.898G>A (A300T in the IDUA gene in a group of 117 healthy individuals from different regions of the country and 14 heterozygous carriers of pathogenic mutations in the HEXA gene (parents of children with confirmed diagnosis of Tay-Sachs disease. The total frequency of haplotypes, associated with arylsulfatase A pseudodeficiency, in healthy people in Ukraine (c.1055G/c.*96G and c.1055G/c.*96A haplotypes was 10.3%. The frequency of c.739C>T (R247W allele, associated with hexo­saminidase A pseudodeficiency, among Tay-Sachs carriers from Ukraine was 7.1%. The total frequency of α-glucosidase pseudodeficiency haplotypes in healthy individuals in Ukraine (c.1726A/c.2065A and c.1726G/c.2065A haplotypes was 2.6%. No person among examined individuals with the substitution c.937G>T (D313Y in the GLA1 gene and c.898G>A (A300T in the IDUA gene was found. The differential diagnostics of lysosomal storage diseases requires obligatory determination of the presence of the pseudodeficiency alleles, particularly the ones with high incidence in the total population. Ignoring phenomenon of

  1. 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.

  2. 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

    Science.gov (United States)

    Kimpler, Lisa A.; Glosson, Nicole L.; Downs, Deanna; Gonyo, Patrick; May, Nathan A.; Hudson, Amy W.

    2014-01-01

    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. PMID:24901711

  3. Bowel habits after gastric bypass versus the duodenal switch operation.

    Science.gov (United States)

    Wasserberg, Nir; Hamoui, Nahid; Petrone, Patrizio; Crookes, Peter F; Kaufman, Howard S

    2008-12-01

    One of the perceived disadvantages of the biliopancreatic diversion with duodenal switch operation is diarrhea. The aim of this study was to compare the bowel habits of patients after duodenal switch operation or Roux-en-Y gastric bypass. A prospective comparative case series design was used. Forty-six patients who underwent duodenal switch (n=28) or gastric bypass (n=18) were asked to complete a daily diary for 14 days after losing least 50% of their excess body weight. Data were collected on number of bowel episodes, incontinence, urgency, stool consistency, and awakening from sleep to defecate. Background variables were recorded from the medical files. The duodenal switch group was heavier (body mass index 53.5 vs 47.0 kg/m(2), p=0.03) and older (47.5 vs 41.0 years, p=NS) than the gastric bypass group. Median time to 50% excess body weight loss was 22 months in the duodenal switch group compared to 10.0 months in the gastric bypass group (p=0.001). Patients after duodenal switch surgery reported a median of 23.5 bowel episodes over the 14-day study period compared to 16.5 in the gastric bypass group (p=NS). There was no between-group differences in any of the other bowel parameters studied. Although duodenal switch is associated with more bowel episodes than gastric bypass, the difference is not statistically significant. Bowel habits are similar in patients who achieve 50% estimated body weight loss with duodenal switch surgery or gastric bypass.

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

    International Nuclear Information System (INIS)

    Hu, Dong; Wu, Jing; Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan; Xiao, Jian; Hu, Fengyu; Yang, Yabo; Zhang, Rongbo

    2015-01-01

    The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy

  5. 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.

  6. Serum glycomarkers of endoplasmic reticulum and lysosomal-endosomal system stress in human healthy aging and diseases

    Directory of Open Access Journals (Sweden)

    I. U. Pismenetskaya

    2017-02-01

    Full Text Available To verify the idea that extracellular free oligosaccharides might be able to reflect the functional status of the endoplasmic reticulum (ER and lysosomal-endosomal system, HPLC-profiles of serum-derived free oligosaccharides (FOS in human healthy aging, acute myeloproliferative neoplasms, and cardiovascular pathologies were compared with intracellular glycans. After plasma deproteinization and FOS purification the oligosaccharides were labelled with anthranilic acid, separated into the neutral and charged with QAE Sephadex (Q25-120 chromatography and analysed using high-performance liquid chromatography (HPLC. The charged FOS were digested with a sialidase and compared with free oligosaccharides from transferrin for structural decoding. HPLC-profiles of serum-derived FOS revealed mild delay of the dolichol phosphate cycle in ER, moderate intensification of ER-associated degradation (ERAD and degradation in endosomal-lysosomal system with aging; an inhibition of the dolichol phosphate cycle, intensification of ERAD and increasing of lysosomal exocytosis in acute myeloproliferative neoplasms; intensification of ERAD and glycocojugate degradation with endosomal-lysosomal system in cardiovascular diseases. As serum free oligosaccharides are able to reflect specifically perturbations in ER and endosomal-lysosomal system under wide range of stressors they can serve as extracellular markers of functionality of these organelles.

  7. Dysfunction of autophagy and endosomal-lysosomal pathways: Roles in pathogenesis of Down syndrome and Alzheimer's Disease.

    Science.gov (United States)

    Colacurcio, Daniel J; Pensalfini, Anna; Jiang, Ying; Nixon, Ralph A

    2018-01-01

    Individuals with Down syndrome (DS) have an increased risk of early-onset Alzheimer's Disease (AD), largely owing to a triplication of the APP gene, located on chromosome 21. In DS and AD, defects in endocytosis and lysosomal function appear at the earliest stages of disease development and progress to widespread failure of intraneuronal waste clearance, neuritic dystrophy and neuronal cell death. The same genetic factors that cause or increase AD risk are also direct causes of endosomal-lysosomal dysfunction, underscoring the essential partnership between this dysfunction and APP metabolites in AD pathogenesis. The appearance of APP-dependent endosome anomalies in DS beginning in infancy and evolving into the full range of AD-related endosomal-lysosomal deficits provides a unique opportunity to characterize the earliest pathobiology of AD preceding the classical neuropathological hallmarks. Facilitating this characterization is the authentic recapitulation of this endosomal pathobiology in peripheral cells from people with DS and in trisomy mouse models. Here, we review current research on endocytic-lysosomal dysfunction in DS and AD, the emerging importance of APP/βCTF in initiating this dysfunction, and the potential roles of additional trisomy 21 genes in accelerating endosomal-lysosomal impairment in DS. Collectively, these studies underscore the growing value of investigating DS to probe the biological origins of AD as well as to understand and ameliorate the developmental disability of DS. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Regulation of Lysosomal Function by the DAF-16 Forkhead Transcription Factor Couples Reproduction to Aging in Caenorhabditis elegans.

    Science.gov (United States)

    Baxi, Kunal; Ghavidel, Ata; Waddell, Brandon; Harkness, Troy A; de Carvalho, Carlos E

    2017-09-01

    Aging in eukaryotes is accompanied by widespread deterioration of the somatic tissue. Yet, abolishing germ cells delays the age-dependent somatic decline in Caenorhabditis elegans In adult worms lacking germ cells, the activation of the DAF-9/DAF-12 steroid signaling pathway in the gonad recruits DAF-16 activity in the intestine to promote longevity-associated phenotypes. However, the impact of this pathway on the fitness of normally reproducing animals is less clear. Here, we explore the link between progeny production and somatic aging and identify the loss of lysosomal acidity-a critical regulator of the proteolytic output of these organelles-as a novel biomarker of aging in C. elegans The increase in lysosomal pH in older worms is not a passive consequence of aging, but instead is timed with the cessation of reproduction, and correlates with the reduction in proteostasis in early adult life. Our results further implicate the steroid signaling pathway and DAF-16 in dynamically regulating lysosomal pH in the intestine of wild-type worms in response to the reproductive cycle. In the intestine of reproducing worms, DAF-16 promotes acidic lysosomes by upregulating the expression of v-ATPase genes. These findings support a model in which protein clearance in the soma is linked to reproduction in the gonad via the active regulation of lysosomal acidification. Copyright © 2017 by the Genetics Society of America.

  9. 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).

  10. Loss of the interferon-γ-inducible regulatory immunity-related GTPase (IRG), Irgm1, causes activation of effector IRG proteins on lysosomes, damaging lysosomal function and predicting the dramatic susceptibility of Irgm1-deficient mice to infection.

    Science.gov (United States)

    Maric-Biresev, Jelena; Hunn, Julia P; Krut, Oleg; Helms, J Bernd; Martens, Sascha; Howard, Jonathan C

    2016-04-20

    The interferon-γ (IFN-γ)-inducible immunity-related GTPase (IRG), Irgm1, plays an essential role in restraining activation of the IRG pathogen resistance system. However, the loss of Irgm1 in mice also causes a dramatic but unexplained susceptibility phenotype upon infection with a variety of pathogens, including many not normally controlled by the IRG system. This phenotype is associated with lymphopenia, hemopoietic collapse, and death of the mouse. We show that the three regulatory IRG proteins (GMS sub-family), including Irgm1, each of which localizes to distinct sets of endocellular membranes, play an important role during the cellular response to IFN-γ, each protecting specific membranes from off-target activation of effector IRG proteins (GKS sub-family). In the absence of Irgm1, which is localized mainly at lysosomal and Golgi membranes, activated GKS proteins load onto lysosomes, and are associated with reduced lysosomal acidity and failure to process autophagosomes. Another GMS protein, Irgm3, is localized to endoplasmic reticulum (ER) membranes; in the Irgm3-deficient mouse, activated GKS proteins are found at the ER. The Irgm3-deficient mouse does not show the drastic phenotype of the Irgm1 mouse. In the Irgm1/Irgm3 double knock-out mouse, activated GKS proteins associate with lipid droplets, but not with lysosomes, and the Irgm1/Irgm3(-/-) does not have the generalized immunodeficiency phenotype expected from its Irgm1 deficiency. The membrane targeting properties of the three GMS proteins to specific endocellular membranes prevent accumulation of activated GKS protein effectors on the corresponding membranes and thus enable GKS proteins to distinguish organellar cellular membranes from the membranes of pathogen vacuoles. Our data suggest that the generalized lymphomyeloid collapse that occurs in Irgm1(-/-) mice upon infection with a variety of pathogens may be due to lysosomal damage caused by off-target activation of GKS proteins on lysosomal

  11. Double endoscopic bypass for gastric outlet obstruction and biliary obstruction

    Science.gov (United States)

    Brewer Gutierrez, Olaya I.; Nieto, Jose; Irani, Shayan; James, Theodore; Pieratti Bueno, Renata; Chen, Yen-I; Bukhari, Majidah; Sanaei, Omid; Kumbhari, Vivek; Singh, Vikesh K.; Ngamruengphong, Saowanee; Baron, Todd H.; Khashab, Mouen A.

    2017-01-01

    Background and study aims  Double endoscopic bypass entails EUS-guided gastroenterostomy (EUS-GE) and EUS-guided biliary drainage (EUS-BD) in patients who present with gastric outlet and biliary obstruction. We report a multicenter experience with double endoscopic bypass. Patients and methods  Retrospective, multicenter series involving 3 US centers. Patients who underwent double endoscopic bypass for malignant gastric and biliary obstruction from 1/2015 to 12/2016 were included. Primary outcome was clinical success defined as tolerance of oral intake and resolution of cholestasis. Secondary outcomes included technical success, re-interventions and adverse events (AE). Results  Seven patients with pancreatic head cancer (57.1 % females; mean age 64.6 ± 12.5 years) underwent double endoscopic bypass. Four patients had EUS-GE and EUS-BD performed during the same session with a mean procedure time of 70 ± 20.4 minutes. EUS-GE and EUS-BD were technically successful in all patients, all of whom were able to tolerate oral intake with resolution of cholestasis in 6 (87.5 %). One patient had a repeat EUS-BD with normalization of bilirubin. There were no adverse events. Conclusions  Double endoscopic bypass is feasible and effective when performed by experienced operators. Studies comparing this novel concept to existing techniques are warranted. PMID:28924596

  12. The influence of core bypass flow during SBLOCA

    International Nuclear Information System (INIS)

    Maselj, A.; Jurkovic, M.

    1996-01-01

    Many parameters affect the behaviour of a NPP during a Small Break Loss of Coolant Accident (SBLOCA). The bypass flow between the core side and the downcomer is one of them. Different PWRs have different values of core bypass flow. In spite of the complexity of the real situation in the primary system during SBLOCA, some fundamental details of the phenomena can be explained with simplified mathematical models, which relate on basic parameters of the primary coolant. These models define the conditions for loop seal clearance and final results are confirmed with measured values. The analysis presented in the paper refers to Bethsy Test 9.1.b SB LOCA scenario, with variation of core bypass flow. Basic RELAP5 input model calculation results show very good agreement with the experimental data. The core liquid level depression before loop seal clearance is lower in case of smaller core bypass flow. This affects the fuel clad temperature because of different heat transfer mechanisms. Time of loop seal clearance is delayed with larger core bypass flow and consequently lower differential pressure between downcomer and core. (author)

  13. Natural Product Screening Reveals Naphthoquinone Complex I Bypass Factors.

    Directory of Open Access Journals (Sweden)

    Scott B Vafai

    Full Text Available Deficiency of mitochondrial complex I is encountered in both rare and common diseases, but we have limited therapeutic options to treat this lesion to the oxidative phosphorylation system (OXPHOS. Idebenone and menadione are redox-active molecules capable of rescuing OXPHOS activity by engaging complex I-independent pathways of entry, often referred to as "complex I bypass." In the present study, we created a cellular model of complex I deficiency by using CRISPR genome editing to knock out Ndufa9 in mouse myoblasts, and utilized this cell line to develop a high-throughput screening platform for novel complex I bypass factors. We screened a library of ~40,000 natural product extracts and performed bioassay-guided fractionation on a subset of the top scoring hits. We isolated four plant-derived 1,4-naphthoquinone complex I bypass factors with structural similarity to menadione: chimaphilin and 3-chloro-chimaphilin from Chimaphila umbellata and dehydro-α-lapachone and dehydroiso-α-lapachone from Stereospermum euphoroides. We also tested a small number of structurally related naphthoquinones from commercial sources and identified two additional compounds with complex I bypass activity: 2-methoxy-1,4-naphthoquinone and 2-methoxy-3-methyl-1,4,-naphthoquinone. The six novel complex I bypass factors reported here expand this class of molecules and will be useful as tool compounds for investigating complex I disease biology.

  14. Hypoxia Induces Autophagy through Translational Up-Regulation of Lysosomal Proteins in Human Colon Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Ming-Chih Lai

    Full Text Available Hypoxia occurs in a wide variety of physiological and pathological conditions, including tumorigenesis. Tumor cells have to adapt to hypoxia by altering their gene expression and protein synthesis. Here, we showed that hypoxia inhibits translation through activation of PERK and inactivation of mTOR in human colon cancer HCT116 cells. Prolonged hypoxia (1% O2, 16 h dramatically inhibits general translation in HCT116 cells, yet selected mRNAs remain efficiently translated under such a condition. Using microarray analysis of polysome- associated mRNAs, we identified a large number of hypoxia-regulated genes at the translational level. Efficiently translated mRNAs during hypoxia were validated by polysome profiling and quantitative real-time RT-PCR. Pathway enrichment analysis showed that many of the up-regulated genes are involved in lysosome, glycan and lipid metabolism, antigen presentation, cell adhesion, and remodeling of the extracellular matrix and cytoskeleton. The majority of down-regulated genes are involved in apoptosis, ubiquitin-mediated proteolysis, and oxidative phosphorylation. Further investigation showed that hypoxia induces lysosomal autophagy and mitochondrial dysfunction through translational regulation in HCT116 cells. The abundance of several translation factors and the mTOR kinase activity are involved in hypoxia-induced mitochondrial autophagy in HCT116 cells. Our studies highlight the importance of translational regulation for tumor cell adaptation to hypoxia.

  15. The lysosomal potassium channel TMEM175 adopts a novel tetrameric architecture

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Changkeun; Guo, Jiangtao; Zeng, Weizhong; Kim, Sunghoon; She, Ji; Cang, Chunlei; Ren, Dejian; Jiang , Youxing (UPENN); (UTSMC); (HHMI)

    2017-07-19

    TMEM175 is a lysosomal K+ channel that is important for maintaining the membrane potential and pH stability in lysosomes1. It contains two homologous copies of a six-transmembrane-helix (6-TM) domain, which has no sequence homology to the canonical tetrameric K+ channels and lacks the TVGYG selectivity filter motif found in these channels2, 3, 4. The prokaryotic TMEM175 channel, which is present in a subset of bacteria and archaea, contains only a single 6-TM domain and functions as a tetramer. Here, we present the crystal structure of a prokaryotic TMEM175 channel from Chamaesiphon minutus, CmTMEM175, the architecture of which represents a completely different fold from that of canonical K+ channels. All six transmembrane helices of CmTMEM175 are tightly packed within each subunit without undergoing domain swapping. The highly conserved TM1 helix acts as the pore-lining inner helix, creating an hourglass-shaped ion permeation pathway in the channel tetramer. Three layers of hydrophobic residues on the carboxy-terminal half of the TM1 helices form a bottleneck along the ion conduction pathway and serve as the selectivity filter of the channel. Mutagenesis analysis suggests that the first layer of the highly conserved isoleucine residues in the filter is primarily responsible for channel selectivity. Thus, the structure of CmTMEM175 represents a novel architecture of a tetrameric cation channel whose ion selectivity mechanism appears to be distinct from that of the classical K+ channel family.

  16. Loss of spatacsin function alters lysosomal lipid clearance leading to upper and lower motor neuron degeneration.

    Science.gov (United States)

    Branchu, Julien; Boutry, Maxime; Sourd, Laura; Depp, Marine; Leone, Céline; Corriger, Alexandrine; Vallucci, Maeva; Esteves, Typhaine; Matusiak, Raphaël; Dumont, Magali; Muriel, Marie-Paule; Santorelli, Filippo M; Brice, Alexis; El Hachimi, Khalid Hamid; Stevanin, Giovanni; Darios, Frédéric

    2017-06-01

    Mutations in SPG11 account for the most common form of autosomal recessive hereditary spastic paraplegia (HSP), characterized by a gait disorder associated with various brain alterations. Mutations in the same gene are also responsible for rare forms of Charcot-Marie-Tooth (CMT) disease and progressive juvenile-onset amyotrophic lateral sclerosis (ALS). To elucidate the physiopathological mechanisms underlying these human pathologies, we disrupted the Spg11 gene in mice by inserting stop codons in exon 32, mimicking the most frequent mutations found in patients. The Spg11 knockout mouse developed early-onset motor impairment and cognitive deficits. These behavioral deficits were associated with progressive brain atrophy with the loss of neurons in the primary motor cortex, cerebellum and hippocampus, as well as with accumulation of dystrophic axons in the corticospinal tract. Spinal motor neurons also degenerated and this was accompanied by fragmentation of neuromuscular junctions and muscle atrophy. This new Spg11 knockout mouse therefore recapitulates the full range of symptoms associated with SPG11 mutations observed in HSP, ALS and CMT patients. Examination of the cellular alterations observed in this model suggests that the loss of spatacsin leads to the accumulation of lipids in lysosomes by perturbing their clearance from these organelles. Altogether, our results link lysosomal dysfunction and lipid metabolism to neurodegeneration and pinpoint a critical role of spatacsin in lipid turnover. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. 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.

  18. Lysosomal storage disease: gene therapy on both sides of the blood-brain barrier.

    Science.gov (United States)

    Aronovich, Elena L; Hackett, Perry B

    2015-02-01

    Most lysosomal storage disorders affect the nervous system as well as other tissues and organs of the body. Previously, the complexities of these diseases, particularly in treating neurologic abnormalities, were too great to surmount. However, based on recent developments there are realistic expectations that effective therapies are coming soon. Gene therapy offers the possibility of affordable, comprehensive treatment associated with these diseases currently not provided by standards of care. With a focus on correction of neurologic disease by systemic gene therapy of mucopolysaccharidoses types I and IIIA, we review some of the major recent advances in viral and non-viral vectors, methods of their delivery and strategies leading to correction of both the nervous and somatic tissues as well as evaluation of functional correction of neurologic manifestations in animal models. We discuss two questions: what systemic gene therapy strategies work best for correction of both somatic and neurologic abnormalities in a lysosomal storage disorder and is there evidence that targeting peripheral tissues (e.g., in the liver) has a future for ameliorating neurologic disease in patients? Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  19. The fusion of autophagosome with lysosome is impaired in L-arginine-induced acute pancreatitis.

    Science.gov (United States)

    Zhu, Hongwei; Yu, Xiao; Zhu, Shaihong; Li, Xia; Lu, Ben; Li, Zhiqiang; Yu, Can

    2015-01-01

    Acute pancreatitis is an inflammatory pancreatic disease that carries considerable morbidity and mortality. The pathogenesis of this disease remains poorly understood. We investigated the incidence of autophagy in mice following induction of acute pancreatitis. Mice were received intraperitoneal injections of L-arginine (200 mg × 2/100 g BW), while controls were administered with saline. Pancreatic tissues were assessed by histology, electron microscopy and western blotting. Injection of L-arginine resulted in the accumulation of autophagosomes and a relative paucity of autolysosomes. Moreover, the autophagy marker p62 is significantly increased. However, the lysosomal-associated membrane protein-2 (Lamp-2), a protein that is required for the proper fusion of autophagosomes with lysosomes, is decreased in acute pancreatitis. These results suggest that a crucial role for autophagy and Lamp-2 in the pathogenesis of acute pancreatitis. Our data suggest that the autophagic flux is impaired in acute pancreatitis. The depletion of Lamp-2 may play a role in the pathogenesis of acute pancreatitis.

  20. Newborn screening for lysosomal storage disorders: clinical evaluation of a two-tier strategy.

    Science.gov (United States)

    Meikle, Peter J; Ranieri, Enzo; Simonsen, Henrik; Rozaklis, Tina; Ramsay, Steve L; Whitfield, Phillip D; Fuller, Maria; Christensen, Ernst; Skovby, Flemming; Hopwood, John J

    2004-10-01

    To evaluate the use of protein markers using immune-quantification assays and of metabolite markers using tandem mass spectrometry for the identification, at birth, of individuals who have a lysosomal storage disorder. A retrospective analysis was conducted of Guthrie cards that were collected from newborns in Denmark during the period 1982-1997. Patients whose lysosomal storage disorder (LSD; 47 representing 12 disorders) was diagnosed in Denmark during the period 1982-1997 were selected, and their Guthrie cards were retrieved from storage. Control cards (227) were retrieved from the same period. Additional control cards (273) were collected from the South Australian Screening Centre (Australia). From 2 protein and 94 metabolite markers, 15 were selected and evaluated for their use in the identification of LSDs. Glycosphingolipid and oligosaccharide markers showed 100% sensitivity and specificity for the identification of Fabry disease, alpha-mannosidosis, mucopolysaccharidosis (MPS) IVA, MPS IIIA, Tay-Sachs disease, and I-cell disease. Lower sensitivities were observed for Gaucher disease and sialidosis. No useful markers were identified for Krabbe disease, MPS II, Pompe disease, and Sandhoff disease. The protein markers LAMP-1 and saposin C were not able to differentiate individuals who had an LSD from the control population. Newborn screening for selected LSDs is possible with current technology. However, additional development is required to provide a broad coverage of disorders in a single, viable program.

  1. Acetate-induced apoptosis in colorectal carcinoma cells involves lysosomal membrane permeabilization and cathepsin D release.

    Science.gov (United States)

    Marques, C; Oliveira, C S F; Alves, S; Chaves, S R; Coutinho, O P; Côrte-Real, M; Preto, A

    2013-02-21

    Colorectal carcinoma (CRC) is one of the most common causes of cancer-related mortality. Short-chain fatty acids secreted by dietary propionibacteria from the intestine, such as acetate, induce apoptosis in CRC cells and may therefore be relevant in CRC prevention and therapy. We previously reported that acetic acid-induced apoptosis in Saccharomyces cerevisiae cells involves partial vacuole permeabilization and release of Pep4p, the yeast cathepsin D (CatD), which has a protective role in this process. In cancer cells, lysosomes have emerged as key players in apoptosis through selective lysosomal membrane permeabilization (LMP) and release of cathepsins. However, the role of CatD in CRC survival is controversial and has not been assessed in response to acetate. We aimed to ascertain whether LMP and CatD are involved in acetate-induced apoptosis in CRC cells. We showed that acetate per se inhibits proliferation and induces apoptosis. More importantly, we uncovered that acetate triggers LMP and CatD release to the cytosol. Pepstatin A (a CatD inhibitor) but not E64d (a cathepsin B and L inhibitor) increased acetate-induced apoptosis of CRC cells, suggesting that CatD has a protective role in this process. Our data indicate that acetate induces LMP and subsequent release of CatD in CRC cells undergoing apoptosis, and suggest exploiting novel strategies using acetate as a prevention/therapeutic agent in CRC, through simultaneous treatment with CatD inhibitors.

  2. Macroautophagy-generated increase of lysosomal amyloid β-protein mediates oxidant-induced apoptosis of cultured neuroblastoma cells

    DEFF Research Database (Denmark)

    Zheng, Lin; Terman, Alexei; Hallbeck, Martin

    2011-01-01

    and accumulation of Aβ within lysosomes, induced apoptosis in differentiated SH-SY5Y neuroblastoma cells. Cells under hyperoxia showed: (1) increased numbers of autophagic vacuoles that contained amyloid precursor protein (APP) as well as Aβ monomers and oligomers, (2) increased reactive oxygen species production......, and (3) enhanced apoptosis. Oxidant-induced apoptosis positively correlated with cellular Aβ production, being the highest in cells that were stably transfected with APP Swedish KM670/671NL double mutation. Inhibition of γ-secretase, prior and/or in parallel to hyperoxia, suggested that the increase...... and resulting lysosomal Aβ accumulation are essential for oxidant-induced apoptosis in cultured neuroblastoma cells and provide additional support for the interactive role of oxidative stress and the lysosomal system in AD-related neurodegeneration....

  3. Alkaloids from the poisonous plant Ipomoea carnea: effects on intracellular lysosomal glycosidase activities in human lymphoblast cultures.

    Science.gov (United States)

    Ikeda, Kyoko; Kato, Atsushi; Adachi, Isao; Haraguchi, Mitsue; Asano, Naoki

    2003-12-17

    There is natural intoxication of livestock by the ingestion of Ipomoea carnea (Convolvulaceae) in Brazil and other parts of the world. The alkaloidal glycosidase inhibitors swainsonine, 2-epi-lentiginosine, and calystegines B(1), B(2), B(3), and C(1) have been identified as constituents of this plant. Swainsonine is a potent inhibitor of rat lysosomal alpha-mannosidase, with an IC(50) value of 0.02 microM, whereas calystegines B(1), B(2), and C(1) are potent inhibitors of rat lysosomal beta-glucosidase, with IC(50) values of 2.1, 0.75, and 0.84 microM, respectively. The action of swainsonine results in a lysosomal storage disorder that closely mimics alpha-mannosidosis in humans. To determine whether the toxicity of I. carnea to livestock is due to purely swainsonine or due to a combination of effects by swainsonine and calystegines, intracellular lysosomal glycosidase activities in normal human lymphoblasts grown with inhibitors in the medium were examined. Incubation of lymphoblasts with 0.1 microM swainsonine for 3 days resulted in approximately 60% reduction of alpha-mannosidase activity. On the other hand, calystegines B(2) and C(1) showed no inhibition of beta-glucosidase up to 1 mM; instead inclusion of calystegines B(2) and C(1) at 100 microM in the culture medium increased its activity by 1.5- and 1.6-fold, respectively. Calystegines B(2) and C(1) seem to act as chemical chaperones, enhancing correct folding of the enzyme and enabling smooth trafficking to the lysosome. The lysosomal beta-glucosidase inhibitory calystegines seem to have little risk of inducing intoxication of livestock.

  4. Robotically assisted totally endoscopic coronary artery bypass surgery

    Science.gov (United States)

    Canale, Leonardo Secchin; Mick, Stephanie; Mihaljevic, Tomislav; Nair, Ravi

    2013-01-01

    Robotically assisted totally endoscopic coronary artery bypass surgery has emerged as a feasible and efficient alternative to conventional full sternotomy coronary artery bypass graft surgery in selected patients. This minimally invasive approach using the daVinci robotic system allows fine intrathoracic maneuvers and excellent view of the coronary arteries. Both on-pump and off-pump operations can be performed to treat single and multivessel disease. Hybrid approaches have the potential of offering complete revascularization with the “best of both worlds” from surgery (internal mammary artery anastomosis in less invasive fashion) and percutaneous coronary intervention (least invasive approach). In this article we review the indications, techniques, short and long term results, as well as current developments in totally endoscopic robotic coronary artery bypass operations. PMID:24251021

  5. Right ventricle contractility during early postoperative period after coronary artery bypass grafting with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    А. Е. Баутин

    2015-10-01

    Full Text Available Emphasis in this research was placed on contractility of the right ventricle with regard to its relationship with systemic hemodynamics in patients undergoing coronary artery bypass grafting (CABG under cardiopulmonary bypass (CPB. The study included 25 patients (14 males, 11 females, mean age was 587 years admitted to ICU after CABG under CPB. All patients required inotropic therapy. The criterion for prescribing inotropic support in the postoperative period was a drop of the stroke volume index of the left ventricle below 35 ml/m 2 provided that the values of this indicator were normal before the perfusion period. Patients with previous pathology of the right ventricle or right coronary artery were excluded from the study. To evaluate the right ventricular function and systemic hemodynamics indicators, use was made of the PiCCO plus system and VoLEF addon device. It was found out that reduced contractility of the right ventricle may cause the reduction in stroke volume of the left ventricle with normal contractility. It was also observed that the increase of preload in patients with right ventricular ejection fraction less than 30% does not improve its function but leads to the increase of its end-diastolic volume. In 68% of cases, the need in inotropic agents in the early postoperative period after CABG was associated with the drop in right ventricle contractility, in 40% - with isolated right ven-tricular dysfunction. Patients with isolated reduction in right ventricle contractility required a longer period of inotropic support and ICU stay as compared with those with left ventricular failure.

  6. Diabetes resolution after one anastomosis gastric bypass.

    Science.gov (United States)

    Abu-Abeid, Adam; Lessing, Yonatan; Pencovich, Niv; Dayan, Danit; Klausner, Joseph M; Abu-Abeid, Subhi

    2018-02-01

    Diabetes and other obesity-related diseases are a worldwide pandemic that transcends geographic borders as well as socioeconomic levels. Currently, it is well known that medical treatment alone is insufficient to ensure adequate and sustainable weight loss and co-morbidity resolution. It has been well proven that bariatric surgery can produce almost immediate resolution of diabetes and other co-morbidities as well as long-term weight loss. Here, we present our experience with the one anastomosis gastric bypass (OAGB) in terms of weight loss and diabetes resolution with 1 year of follow-up. Large, metropolitan, tertiary, university hospital. A retrospective analysis of all patients who underwent OAGB between March 2015 and March 2016 was performed. Patient demographic characteristics, co-morbidities, operative and postoperative data, as well as first year outcomes were collected and analyzed. There were 407 patients who underwent OAGB (254 females, average age 41.8 ± 12.05 yr, body mass index = 41.7 ± 5.77 kg/m 2 ). Of patients, 102 (25.1%) had diabetes with average glycosylated hemoglobin of 8.64 ± 1.94 g%, 93 (22.8%) had hypertension, 123 (28.8%) had hyperlipidemia, and 35 patients (8.6%) had obstructive sleep apnea. The average length of hospital stay was 2.2 ± .84 days (range, 2-10 d). The average excess weight loss 1 year after surgery was 88.9 ± 27.3. After 1 year, follow-up data were available for more than 85% of the study's general population. Of 102 diabetic patients, only 8 (7.8%) were still considered diabetic and taking antidiabetic medication, with an average glycosylated hemoglobin of 5.4 ± 0.6. OAGB may be performed safely and with promising efficacy as both a primary and a revisional bariatric surgery, and it offers excellent resolution of diabetes. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  7. Autopsy findings following gastric bypass surgery for morbid obesity.

    Science.gov (United States)

    Melinek, Judy; Livingston, Edward; Cortina, Galen; Fishbein, Michael C

    2002-09-01

    Roux-en-Y gastric bypass, currently the most frequently performed surgical procedure for morbid obesity, has a low but significant mortality rate. There are limited data documenting the findings at necropsy in patients who have died following this procedure. To determine cause of death and pathologic processes present in obese subjects dying after gastric bypass surgery. We studied 10 patients who underwent autopsy following gastric bypass surgery for morbid obesity between the years 1994 and 2000. There were 6 men and 4 women. The mean age of the patients was 48 years (range, 28-62 years). The mean preoperative weight was 162 kg (range, 112-245 kg), and the mean body mass index was 54 kg/m(2) (range, 39-76 kg/m(2)), similar to all patients undergoing gastric bypass at our institution during the same period. Five deaths were directly attributable to technical complications. Five deaths were attributed to underlying comorbid conditions. One patient died of cirrhosis and one of pulmonary hemorrhage. Three patients died from pulmonary embolism. However, 8 of 10 patients had microscopic evidence of pulmonary emboli, despite prophylaxis for deep vein thrombosis. Most patients had some degree of steatohepatitis and hepatic fibrosis (80% and 70%, respectively). There were no deaths from primary cardiac events. In patients who die after Roux-en-Y gastric bypass, half die due to technical complications, whereas the other half die of complications of their obesity. Clinically, only 20% of patients were suspected to have pulmonary emboli, yet at autopsy, 80% of patients had pulmonary emboli. In morbidly obese patients undergoing Roux-en-Y gastric bypass, there is an unexpectedly high rate of clinically silent pulmonary emboli contributing to morbidity and mortality.

  8. Implantable endoscopic gastric bypass - device and experimental procedure.

    Science.gov (United States)

    Schurr, Marc Oliver; Ho, Chi-Nghia; Rieber, Fabian; Fleisch, Christine; Coscarella, Giorgio; Tognoni, Valeria; Di Lorenzo, Nicola

    2009-01-01

    Malabsorptive bariatric surgery is an effective treatment option for morbid obesity, but may be associated with complications and side effects. We have developed a new experimental approach to creating a gastric bypass through an intraluminal access. The goal is to reduce postoperative complications and to reduce mid-term side-effects of malabsorptive bypass food passage and to allow easy reversion of the procedure. The new procedure is based on an implantable gastric bypass device, installed by combined transoral flexible and minimally invasive abdominal access. The newly developed device and procedure were studied in a pilot experimental trial in the porcine animal model (n=8). Endpoints were the feasibility of the technical procedure, the ability of the animal to eat and digest food, the implant functionality over the survival period and the absence of major complications over a short-term follow-up (one week). The procedure was technically successful in all eight animals. Animals were able to take in food and water till sacrifice. Four animals had major complications (one abdominal wall dehiscence, one invagination ileus of the small bowel, one dehiscence of the gastro-jejunal anastomosis and one myocardial infarction) and did not complete follow-up. In two cases migration of the device into the stomach was observed. The difference between our experimental technique and the gold standard surgical methods for gastric bypass consists of the endoluminal approach by implanting an intraluminal gastric bypass device. This concept avoids gastric transsection and an additional anastomosis and enables an adjustable food passage between the bypass and the natural duodenal passage. Further long-term follow-up studies are required.

  9. Reduced complement activation during cardiopulmonary bypass does not affect the postoperative acute phase response

    NARCIS (Netherlands)

    van den Goor, J.; Nieuwland, R.; van den Brink, A.; van Oeveren, W.; Rutten, 27818; Tijssen, J.; Eijsman, L.; Rutten, P

    2004-01-01

    Objective: In the present study the relationship was evaluated between perioperative inflammation and the postoperative acute phase response in patients undergoing elective coronary artery bypass grafting (CABG) assisted by cardiopulmonary bypass (CPB). CPB circuits contained either non-coated-

  10. A Bypass Program of Supportive Instruction for Secondary Students with Learning Disabilities.

    Science.gov (United States)

    Mosby, Robert J.

    1979-01-01

    The developmental bypass teaching technique (which provides students an opportunity to bypass their learning deficits) was studied with regard to social studies achievement and classroom behaviors in 50 learning disabled junior high school students. (Author/PHR)

  11. Exercise thallium-201 scintigraphy in evaluating aortocoronary bypass surgery

    International Nuclear Information System (INIS)

    Iskandrian, A.S.; Haaz, W.; Segal, B.L.; Kane, S.A.

    1981-01-01

    Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts

  12. Construct exploit constraint in crash analysis by bypassing canary

    Science.gov (United States)

    Huang, Ning; Huang, Shuguang; Huang, Hui; Chang, Chao

    2017-08-01

    Selective symbolic execution is a common program testing technology. Developed on the basis of it, some crash analysis systems are often used to test the fragility of the program by constructing exploit constraints, such as CRAX. From the study of crash analysis based on symbolic execution, this paper find that this technology cannot bypass the canary stack protection mechanisms. This paper makes the improvement uses the API hook in Linux. Experimental results show that the use of API hook can effectively solve the problem that crash analysis cannot bypass the canary protection.

  13. 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 through...

  14. 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 the...

  15. On-pump versus off-pump coronary artery bypass surgery in elderly patients

    DEFF Research Database (Denmark)

    Houlind, Kim Christian; Kjeldsen, Bo Juul; Madsen, Susanne Nørgaard

    2012-01-01

    Conventional coronary artery bypass grafting performed with the use of cardiopulmonary bypass is a well-validated treatment for patients with ischemic heart disease. Off-pump coronary artery bypass grafting (OPCAB) has been suggested to reduce the number of perioperative complications, especially...... in elderly patients....

  16. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter nonbiologic...

  17. 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 II...

  18. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    OpenAIRE

    Chen Ting; Yang Kang; Wu Li-Li

    2016-01-01

    The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  19. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    Directory of Open Access Journals (Sweden)

    Chen Ting

    2016-01-01

    Full Text Available The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  20. Amyloid-β secretion, generation, and lysosomal sequestration in response to proteasome inhibition

    DEFF Research Database (Denmark)

    Agholme, Lotta; Hallbeck, Martin; Benedikz, Eirikur

    2012-01-01

    , as the autophagosome has been suggested as a site of amyloid-β (Aβ) generation. In this study, we investigated the effect of proteasome inhibition on Aβ accumulation and secretion, as well as the processing of amyloid-β protein precursor (AβPP) in AβPP(Swe) transfected SH-SY5Y neuroblastoma cells. We show...... makes C99 available for γ-secretase cleavage, leading to Aβ generation. Inhibition of autophagy after proteasome inhibition led to reduced levels of intracellular, but not secreted Aβ, and tended to further increase the C99 to AβPP ratio, supporting involvement of the autophagosome in Aβ generation....... Furthermore, proteasome inhibition caused a reduction in cellular viability, which was reverted by inhibition of autophagy. Dysfunction of the proteasome could cause lysosomal accumulation of Aβ, as well as increased generation and secretion of Aβ, which is partly facilitated by autophagy. As a decrease...

  1. Nuclear morphology and lysosomal stability of molluskan hemocytes as possible biomarkers of arsenic toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sudipta [Post Graduate Department of Zoology, Parasitology and Medical Entomology Laboratory, Darjeeling Government College, Darjeeling (India); Ray, Sajal [Department of Zoology, Aquatic Toxicology Laboratory, University of Calcutta, Kolkata (India)

    2009-10-15

    The frequency of nuclear aberrations and neutral red retention time of hemocytes in the mollusk Lamellidens marginalis were recorded under exposure to sublethal concentrations of sodium arsenite in order to examine the sensitivity and effectiveness of these inexpensive assays for screening the toxicity of As{sup 3+}in a freshwater ecosystem. A dose and time dependent increase in the density of micronucleated and binucleated hemocytes and gill cells was indicative of the pronounced genotoxic effect of arsenic on this animal. The disruption of intrahemocyte homeostasis imposed by this natural toxicant was evident from a dose and time dependent reduction in the lysosomal stability of the hemocytes of the animal. The tested parameters are indicative of arsenic toxicity in L. marginalis in the freshwater systems of the arsenic affected geographical areas of West Bengal, India. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  2. Structure and function of lysosomal phospholipase A2 and lecithin:cholesterol acyltransferase

    Science.gov (United States)

    Glukhova, Alisa; Hinkovska-Galcheva, Vania; Kelly, Robert; Abe, Akira; Shayman, James A.; Tesmer, John J. G.

    2015-03-01

    Lysosomal phospholipase A2 (LPLA2) and lecithin:cholesterol acyltransferase (LCAT) belong to a structurally uncharacterized family of key lipid-metabolizing enzymes responsible for lung surfactant catabolism and for reverse cholesterol transport, respectively. Whereas LPLA2 is predicted to underlie the development of drug-induced phospholipidosis, somatic mutations in LCAT cause fish eye disease and familial LCAT deficiency. Here we describe several high-resolution crystal structures of human LPLA2 and a low-resolution structure of LCAT that confirms its close structural relationship to LPLA2. Insertions in the α/β hydrolase core of LPLA2 form domains that are responsible for membrane interaction and binding the acyl chains and head groups of phospholipid substrates. The LCAT structure suggests the molecular basis underlying human disease for most of the known LCAT missense mutations, and paves the way for rational development of new therapeutics to treat LCAT deficiency, atherosclerosis and acute coronary syndrome.

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

    DEFF Research Database (Denmark)

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

    , the 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 both tumor grade and patient survival. Moreover double immunofluorescence stainings with LAMP-1 and the stem cell marker CD133 as well as the macrophage marker CD68 were performed. The results showed that LAMP-1 was expressed in the vast majority of tumors being present in the cytoplasm of single tumor...... cells, cell clusters and in blood vessel endothelial cells. The LAMP-1 expression in glioblastomas was significantly higher than in diffuse and anaplastic astrocytomas (pLAMP-1 and patient overall survival was found. Double immunofluorescence staining...

  4. Interaction of Legionella pneumophila with Acanthamoeba castellanii: uptake by coiling phagocytosis and inhibition of phagosome-lysosome fusion.

    Science.gov (United States)

    Bozue, J A; Johnson, W

    1996-01-01

    Legionella pneumophila is a facultative intracellular parasite able to survive within both human monocytes and amoebae. We have demonstrated that processing of L. pneumophila by the free-living amoeba Acanthamoeba castellanii shows many similarities to the processing of L. pneumophila by monocytes. These similarities include uptake of L. pneumophila by coiling phagocytosis and the subsequent confinement of L. pneumophila in a ribosome-studded phagosome. In addition, as in monocytes, inhibition of lysosomal fusion with phagosomes containing L. pneumophila was detected in amoebae. With all clinical isolates, inhibition of phagosomes-lysosome fusion correlated with virulence. However, with one of the environmental isolates tested, no significant difference in phagosome-lysosome fusion was observed between the virulent and avirulent forms. These results indicate that the avirulent form of this isolate differed from the virulent form in some other respect critical to intracellular survival. Therefore, intracellular multiplication of L. pneumophila within A. castellanii may not be solely dependent upon the inhibition of lysosomal fusion. PMID:8550225

  5. Lysosomal regulation of cholesterol homeostasis in tuberous sclerosis complex is mediated via NPC1 and LDL-R.

    Science.gov (United States)

    Filippakis, Harilaos; Alesi, Nicola; Ogorek, Barbara; Nijmeh, Julie; Khabibullin, Damir; Gutierrez, Catherine; Valvezan, Alexander J; Cunningham, James; Priolo, Carmen; Henske, Elizabeth P

    2017-06-13

    Tuberous sclerosis complex (TSC) is a multisystem disease associated with hyperactive mTORC1. The impact of TSC1/2 deficiency on lysosome-mediated processes is not fully understood. We report here that inhibition of lysosomal function using chloroquine (CQ) upregulates cholesterol homeostasis genes in TSC2-deficient cells. This TSC2-dependent transcriptional signature is associated with increased accumulation and intracellular levels of both total cholesterol and cholesterol esters. Unexpectedly, engaging this CQ-induced cholesterol uptake pathway together with inhibition of de novo cholesterol synthesis allows survival of TSC2-deficient, but not TSC2-expressing cells. The underlying mechanism of TSC2-deficient cell survival is dependent on exogenous cholesterol uptake via LDL-R, and endosomal trafficking mediated by Vps34. Simultaneous inhibition of lysosomal and endosomal trafficking inhibits uptake of esterified cholesterol and cell growth in TSC2-deficient, but not TSC2-expressing cells, highlighting the TSC-dependent lysosome-mediated regulation of cholesterol homeostasis and pointing toward the translational potential of these pathways for the therapy of TSC.

  6. Discovery of Small Molecules That Induce Lysosomal Cell Death in Cancer Cell Lines Using an Image-Based Screening Platform

    NARCIS (Netherlands)

    Pagliero, Romina J; D'Astolfo, Diego S; Lelieveld, Daphne; Pratiwi, Riyona D; Aits, Sonja; Jaattela, Marja; Martin, Nathaniel I; Klumperman, Judith; Egan, David A

    2016-01-01

    The lysosomal cell death (LCD) pathway is a caspase 3-independent cell death pathway that has been suggested as a possible target for cancer therapy, making the development of sensitive and specific high-throughput (HT) assays to identify LCD inducers highly desirable. In this study, we report a

  7. Concanavalin A/IFN-gamma triggers autophagy-related necrotic hepatocyte death through IRGM1-mediated lysosomal membrane disruption.

    Directory of Open Access Journals (Sweden)

    Chih-Peng Chang

    Full Text Available Interferon-gamma (IFN-γ, a potent Th1 cytokine with multiple biological functions, can induce autophagy to enhance the clearance of the invading microorganism or cause cell death. We have reported that Concanavalin A (Con A can cause autophagic cell death in hepatocytes and induce both T cell-dependent and -independent acute hepatitis in immunocompetent and immunodeficient mice, respectively. Although IFN-γ is known to enhance liver injury in Con A-induced hepatitis, its role in autophagy-related hepatocyte death is not clear. In this study we report that IFN-γ can enhance Con A-induced autophagic flux and cell death in hepatoma cell lines. A necrotic cell death with increased lysosomal membrane permeabilization (LMP is observed in Con A-treated hepatoma cells in the presence of IFN-γ. Cathepsin B and L were released from lysosomes to cause cell death. Furthermore, IFN-γ induces immunity related GTPase family M member 1(IRGM1 translocation to lysosomes and prolongs its activity in Con A-treated hepatoma cells. Knockdown of IRGM1 inhibits the IFN-γ/Con A-induced LMP change and cell death. Furthermore, IFN-γ(-/- mice are resistant to Con A-induced autophagy-associated necrotic hepatocyte death. We conclude that IFN-γ enhances Con A-induced autophagic flux and causes an IRGM1-dependent lysosome-mediated necrotic cell death in hepatocytes.

  8. Intermittent fasting preserves beta-cell mass in obesity-induced diabetes via the autophagy-lysosome pathway.

    Science.gov (United States)

    Liu, Haiyan; Javaheri, Ali; Godar, Rebecca J; Murphy, John; Ma, Xiucui; Rohatgi, Nidhi; Mahadevan, Jana; Hyrc, Krzysztof; Saftig, Paul; Marshall, Connie; McDaniel, Michael L; Remedi, Maria S; Razani, Babak; Urano, Fumihiko; Diwan, Abhinav

    2017-01-01

    Obesity-induced diabetes is characterized by hyperglycemia, insulin resistance, and progressive beta cell failure. In islets of mice with obesity-induced diabetes, we observe increased beta cell death and impaired autophagic flux. We hypothesized that intermittent fasting, a clinically sustainable therapeutic strategy, stimulates autophagic flux to ameliorate obesity-induced diabetes. Our data show that despite continued high-fat intake, intermittent fasting restores autophagic flux in islets and improves glucose tolerance by enhancing glucose-stimulated insulin secretion, beta cell survival, and nuclear expression of NEUROG3, a marker of pancreatic regeneration. In contrast, intermittent fasting does not rescue beta-cell death or induce NEUROG3 expression in obese mice with lysosomal dysfunction secondary to deficiency of the lysosomal membrane protein, LAMP2 or haplo-insufficiency of BECN1/Beclin 1, a protein critical for autophagosome formation. Moreover, intermittent fasting is sufficient to provoke beta cell death in nonobese lamp2 null mice, attesting to a critical role for lysosome function in beta cell homeostasis under fasting conditions. Beta cells in intermittently-fasted LAMP2- or BECN1-deficient mice exhibit markers of autophagic failure with accumulation of damaged mitochondria and upregulation of oxidative stress. Thus, intermittent fasting preserves organelle quality via the autophagy-lysosome pathway to enhance beta cell survival and stimulates markers of regeneration in obesity-induced diabetes.

  9. The autophagy/lysosome pathway is impaired in SCA7 patients and SCA7 knock-in mice

    NARCIS (Netherlands)

    Alves, Sandro; Cormier-Dequaire, Florence; Marinello, Martina; Marais, Thibaut; Muriel, Marie-Paule; Beaumatin, Florian; Charbonnier-Beaupel, Fanny; Tahiri, Khadija; Seilhean, Danielle; El Hachimi, Khalid; Ruberg, Merle; Stevanin, Giovanni; Barkats, Martine; den Dunnen, Wilfred; Priault, Muriel; Brice, Alexis; Durr, Alexandra; Corvol, Jean-Christophe; Sittler, Annie

    2014-01-01

    There is still no treatment for polyglutamine disorders, but clearance of mutant proteins might represent a potential therapeutic strategy. Autophagy, the major pathway for organelle and protein turnover, has been implicated in these diseases. To determine whether the autophagy/lysosome system

  10. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; Duross, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-08-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1-/-) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1-/- cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders.

  11. Numerical variation of cell lysosomes of the proximal convoluted tubules of mice Kidneys submitted to different X-ray doses

    International Nuclear Information System (INIS)

    Silva Lapa, R. de C.R. da; Pacheco, I.P.; Segreto, C.

    1984-01-01

    The number of cell lysosomes of the proximal convoluted tubules of mice Kidneys (Mus musculus) before and after whole-body irradiation with different X-ray doses is confronted. The mice were sacrificed after 72 hours and the cortex fragments were conduct to electron microscopy. A statistically significant numerical reduction of the lysosomas was observed in 72 hours. (M.A.C.) [pt

  12. Interaction between HLA-DM and HLA-DR involves regions that undergo conformational changes at lysosomal pH

    NARCIS (Netherlands)

    Ullrich, H. J.; Döring, K.; Grüneberg, U.; Jähnig, F.; Trowsdale, J.; van Ham, S. M.

    1997-01-01

    Antigenic peptide loading of major histocompatibility complex class II molecules is enhanced by lysosomal pH and catalyzed by the HLA-DM molecule. The physical mechanism behind the catalytic activity of DM was investigated by using time-resolved fluorescence anisotropy (TRFA) and fluorescence

  13. HLA-DM and MHC class II molecules co-distribute with peptidase-containing lysosomal subcompartments

    NARCIS (Netherlands)

    Fernandez-Borja, M.; Verwoerd, D.; Sanderson, F.; Aerts, H.; Trowsdale, J.; Tulp, A.; Neefjes, J.

    1996-01-01

    MHC class II molecules associate with peptides in the endocytic pathway. Different endosomal locations for peptide loading of class II molecules, varying from early endosomes (EE) to lysosomes, have been assigned on the basis of subcellular fractionation experiments. We have determined the

  14. Partial restoration of mutant enzyme homeostasis in three distinct lysosomal storage disease cell lines by altering calcium homeostasis.

    Directory of Open Access Journals (Sweden)

    Ting-Wei Mu

    2008-02-01

    Full Text Available A lysosomal storage disease (LSD results from deficient lysosomal enzyme activity, thus the substrate of the mutant enzyme accumulates in the lysosome, leading to pathology. In many but not all LSDs, the clinically most important mutations compromise the cellular folding of the enzyme, subjecting it to endoplasmic reticulum-associated degradation instead of proper folding and lysosomal trafficking. A small molecule that restores partial mutant enzyme folding, trafficking, and activity would be highly desirable, particularly if one molecule could ameliorate multiple distinct LSDs by virtue of its mechanism of action. Inhibition of L-type Ca2+ channels, using either diltiazem or verapamil-both US Food and Drug Administration-approved hypertension drugs-partially restores N370S and L444P glucocerebrosidase homeostasis in Gaucher patient-derived fibroblasts; the latter mutation is associated with refractory neuropathic disease. Diltiazem structure-activity studies suggest that it is its Ca2+ channel blocker activity that enhances the capacity of the endoplasmic reticulum to fold misfolding-prone proteins, likely by modest up-regulation of a subset of molecular chaperones, including BiP and Hsp40. Importantly, diltiazem and verapamil also partially restore mutant enzyme homeostasis in two other distinct LSDs involving enzymes essential for glycoprotein and heparan sulfate degradation, namely alpha-mannosidosis and type IIIA mucopolysaccharidosis, respectively. Manipulation of calcium homeostasis may represent a general strategy to restore protein homeostasis in multiple LSDs. However, further efforts are required to demonstrate clinical utility and safety.

  15. Lysosomal-cationic test and NBT reduction test just partially reflect the completeness of phagocytic process in human granulocytes.

    Science.gov (United States)

    Belokrylov, G A; Popova, O Ya

    2002-01-01

    The results of NBT test correlated with the index of phagocytosis completeness in only 43% of 21 clinically healthy volunteers. The level of the lysosomal-cationic test was significantly reduced only if the phagocytosis completeness index was markedly decreased. The latter is an integral value reflecting the bactericidal activity of granulocytes.

  16. Ouabain-induced internalization and lysosomal degradation of the Na+/K+-ATPase.

    Science.gov (United States)

    Cherniavsky-Lev, Marina; Golani, Ofra; Karlish, Steven J D; Garty, Haim

    2014-01-10

    Internalization of the Na(+)/K(+)-ATPase (the Na(+) pump) has been studied in the human lung carcinoma cell line H1299 that expresses YFP-tagged α1 from its normal genomic localization. Both real-time imaging and surface biotinylation have demonstrated internalization of α1 induced by ≥100 nm ouabain which occurs in a time scale of hours. Unlike previous studies in other systems, the ouabain-induced internalization was insensitive to Src or PI3K inhibitors. Accumulation of α1 in the cells could be augmented by inhibition of lysosomal degradation but not by proteosomal inhibitors. In agreement, the internalized α1 could be colocalized with the lysosomal marker LAMP1 but not with Golgi or nuclear markers. In principle, internalization could be triggered by a conformational change of the ouabain-bound Na(+)/K(+)-ATPase molecule or more generally by the disruption of cation homeostasis (Na(+), K(+), Ca(2+)) due to the partial inhibition of active Na(+) and K(+) transport. Overexpression of ouabain-insensitive rat α1 failed to inhibit internalization of human α1 expressed in the same cells. In addition, incubating cells in a K(+)-free medium did not induce internalization of the pump or affect the response to ouabain. Thus, internalization is not the result of changes in the cellular cation balance but is likely to be triggered by a conformational change of the protein itself. In physiological conditions, internalization may serve to eliminate pumps that have been blocked by endogenous ouabain or other cardiac glycosides. This mechanism may be required due to the very slow dissociation of the ouabain·Na(+)/K(+)-ATPase complex.

  17. Chitotriosidase activity as additional biomarker in the diagnosis of lysosomal storage diseases

    Directory of Open Access Journals (Sweden)

    N. V. Olkhovych

    2016-02-01

    Full Text Available To date, several genetic variants that lead to a deficiency of chitotriosidase activity have been described. The duplication of 24 bp (dup24bp in exon 10 of the CHIT1 gene, which causes a complete loss of enzymatic activity of the gene product, is the most common among the European population. The aim of the study was to evaluate the possibility of using chitotriosidase activity as an additional biomarker in diagnosis of lysosomal storage diseases (LSDs in Ukraine, to determine this parameter in blood plasma of the patients with various lysosomal diseases and to assess the effect of the presence of dup24bp in the CHIT1 gene on this parameter. It has been shown that chitotriosidase activity in blood plasma is a convenient additional biochemical marker in the diagnosis of some LSDs, namely Gaucher disease, Niemann-Pick disease A, B, C and GM1-gangliosidosis. Reference ranges of the normal chitotriosidase activity were determined in blood plasma of Ukrainian population and found to be 8.0-53.1 nmol 4-methylumbelliferone/h·ml of plasma. The total allele frequency of the dup24bp in the CHIT1 gene in Ukrainian population was determined, which amounted to 0.26 (323/1244 that is higher than in European population. It was indicated that molecular-genetic screening of dup24bp in the CHIT1 gene is a necessary stage in a protocol for the laboratory diagnosis of Gaucher disease, Niemann-Pick disease A, B, C as well as GM1-gangliosidosis to avoid incorrect diagnosis.

  18. Amlexanox provides a potential therapy for nonsense mutations in the lysosomal storage disorder Aspartylglucosaminuria.

    Science.gov (United States)

    Banning, Antje; Schiff, Manuel; Tikkanen, Ritva

    2018-03-01

    Aspartylglucosaminuria (AGU) is a lysosomal storage disorder caused by mutations in the gene for aspartylglucosaminidase (AGA). This enzyme participates in glycoprotein degradation in lysosomes. AGU results in progressive mental retardation, and no curative therapy is currently available. We have here characterized the consequences of AGA gene mutations in a compound heterozygous patient who exhibits a missense mutation producing a Ser72Pro substitution in one allele, and a nonsense mutation Trp168X in the other. Ser72 is not a catalytic residue, but is required for the stabilization of the active site conformation. Thus, Ser72Pro exchange impairs the autocatalytic activation of the AGA precursor, and results in a considerable reduction of the enzyme activity and in altered AGA precursor processing. Betaine, which can partially rescue the AGA activity in AGU patients carrying certain missense mutations, turned out to be ineffective in the case of Ser72Pro substitution. The Trp168X nonsense allele results in complete lack of AGA polypeptide due to nonsense-mediated decay (NMD) of the mRNA. Amlexanox, which inhibits NMD and causes a translational read-through, facilitated the synthesis of a full-length, functional AGA protein from the nonsense allele. This could be demonstrated as presence of the AGA polypeptide and increased enzyme activity upon Amlexanox treatment. Furthermore, in the Ser72Pro/Trp168X expressing cells, Amlexanox induced a synergistic increase in AGA activity and polypeptide processing due to enhanced processing of the Ser72Pro polypeptide. Our data show for the first time that Amlexanox might provide a valid therapy for AGU. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Targeted Polymeric Nanoparticles for Brain Delivery of High Molecular Weight Molecules in Lysosomal Storage Disorders.

    Directory of Open Access Journals (Sweden)

    Marika Salvalaio

    Full Text Available Lysosomal Storage Disorders (LSDs are a group of metabolic syndromes, each one due to the deficit of one lysosomal enzyme. Many LSDs affect most of the organ systems and overall about 75% of the patients present neurological impairment. Enzyme Replacement Therapy, although determining some systemic clinical improvements, is ineffective on the CNS disease, due to enzymes' inability to cross the blood-brain barrier (BBB. With the aim to deliver the therapeutic enzymes across the BBB, we here assayed biodegradable and biocompatible PLGA-nanoparticles (NPs in two murine models for LSDs, Mucopolysaccharidosis type I and II (MPS I and MPS II. PLGA-NPs were modified with a 7-aminoacid glycopeptide (g7, yet demonstrated to be able to deliver low molecular weight (MW molecules across the BBB in rodents. We specifically investigated, for the first time, the g7-NPs ability to transfer a model drug (FITC-albumin with a high MW, comparable to the enzymes to be delivered for LSDs brain therapy. In vivo experiments, conducted on wild-type mice and knockout mouse models for MPS I and II, also included a whole series of control injections to obtain a broad preliminary view of the procedure efficiency. Results clearly showed efficient BBB crossing of albumin in all injected mice, underlying the ability of NPs to deliver high MW molecules to the brain. These results encourage successful experiments with enzyme-loaded g7-NPs to deliver sufficient amounts of the drug to the brain district on LSDs, where exerting a corrective effect on the pathological phenotype.

  20. Preubiquitinated chimeric ErbB2 is constitutively endocytosed and subsequently degraded in lysosomes

    International Nuclear Information System (INIS)

    Vuong, Tram Thu; Berger, Christian; Bertelsen, Vibeke; Rødland, Marianne Skeie; Stang, Espen; Madshus, Inger Helene

    2013-01-01

    The oncoprotein ErbB2 is endocytosis-deficient, probably due to its interaction with Heat shock protein 90. We previously demonstrated that clathrin-dependent endocytosis of ErbB2 is induced upon incubation of cells with Ansamycin derivatives, such as geldanamycin and its derivative 17-AAG. Furthermore, we have previously demonstrated that a preubiquitinated chimeric EGFR (EGFR-Ub 4 ) is constitutively endocytosed in a clathrin-dependent manner. We now demonstrate that also an ErbB2-Ub 4 chimera is endocytosed constitutively and clathrin-dependently. Upon expression, the ErbB2-Ub 4 was further ubiquitinated, and by Western blotting, we demonstrated the formation of both Lys48-linked and Lys63-linked polyubiquitin chains. ErbB2-Ub 4 was constitutively internalized and eventually sorted to late endosomes and lysosomes where the fusion protein was degraded. ErbB2-Ub 4 was not cleaved prior to internalization. Interestingly, over-expression of Ubiquitin Interaction Motif-containing dominant negative fragments of the clathrin adaptor proteins epsin1 and Eps15 negatively affected endocytosis of ErbB2. Altogether, this argues that ubiquitination is sufficient to induce clathrin-mediated endocytosis and lysosomal degradation of the otherwise plasma membrane localized ErbB2. Also, it appears that C-terminal cleavage is not required for endocytosis. -- Highlights: ► A chimera containing ErbB2 and a tetra-Ubiquitin chain internalizes constitutively. ► Receptor fragmentation is not required for endocytosis of ErbB2. ► Ubiquitination is sufficient to induce endocytosis and degradation of ErbB2. ► ErbB2-Ub4 is internalized clathrin-dependently.

  1. Lysosomal arylsulfatase deficiencies in humans: chromosome assignments for arylsulfatase A and B.

    Science.gov (United States)

    DeLuca, C; Brown, J A; Shows, T B

    1979-04-01

    Genetics of human lysosomal arylsulfatases A and B (aryl-sulfate sulfohydrolase, EC 3.1.6.1), associated with childhood disease, has been studied with human-rodent somatic cell hybrids. Deficiency of arylsulfatase A (ARS(A)) in humans results in a progressive neurodegenerative disease, metachromatic leukodystrophy. Deficiency of arylsulfatase B (ARS(B)) is associated with skeletal and growth malformations, termed the Maroteaux-Lamy syndrome. Simultaneous deficiency of both enzymes is associated with the multiple sulfatase deficiency disease, suggesting a common relationship for ARS(A) and ARS(B). The genetic and structural relationships of human ARS(A) and ARS(B) have been determined by the use of human-Chinese hamster somatic cell hybrids. Independent enzyme segregation in cell hybrids demonstrated different chromosome assignments for the structural genes, ARS(A) and ARS(B), coding for the two lysosomal enzymes. ARS(A) activity showed concordant segregation with mitochondrial aconitase encoded by a gene assigned to chromosome 22. ARS(B) segregated with beta-hexosaminidase B encoded by a gene assigned to chromosome 5. These assignments were confirmed by chromosome analyses. The subunit structures of ARS(A) and ARS(B) were determined by their electrophoretic patterns in cell hybrids; a dimeric structure was demonstrated for ARS(A) and a monomeric structure for ARS(B). Although the multiple sulfatase deficiency disorder suggests a shared relationship between ARS(A) and ARS(B), independent segregation of these enzymes in cell hybrids did not support a common polypeptide subunit or structural gene assignment. The evidence demonstrates the assignment of ARS(A) to chromosome 22 and ARS(B) to chromosome 5. A third gene that affects ARS(A) and ARS(B) activity is suggested by the multiple sulfatase deficiency disorder.

  2. Predicting the need for blood during cardiopulmonary bypass

    African Journals Online (AJOL)

    Adele

    ness of autologous blood transfusions during open heart surgery. AR Coetzee, JF Coetzee. Department of Anesthesiology and Critical Care, School of Medicine, Faculty of Health Sciences, University of Stellenbosch, South Africa. Abstract. Background: Haematocrit (Hct) values <18%-20% during cardiopulmonary bypass ...

  3. 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.

  4. 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...

  5. Recovery from circulatory depression after coronary artery bypass surgery

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); R.W. Brower (Ronald); H.J. ten Katen (Harald); G.T. Meester (Geert)

    1980-01-01

    textabstractThe direct traumatic effects of coronary artery bypass surgery may counter-balance the expected improvement of myocardial function in the early postoperative period. In 55 patients, the regional shortening fraction was measured over 12 months using radiopaque epicardial markers pairs

  6. The effect of bypass protein supplementation on the reproductive ...

    African Journals Online (AJOL)

    Unknown

    Short paper and poster abstracts: 38th Congress of the South African Society of Animal Science. The South African Journal of Animal Science is available online at http://www.sasas.co.za/Sajas.html. 60. The effect of bypass protein supplementation on the reproductive performance of. Merino sheep grazing mixed karoo veld.

  7. Using skeletonised grafts for coronary artery bypass grafting.

    Science.gov (United States)

    Bawany, Faizan Imran; Khan, Muhammad Shahzeb; Khan, Asadullah; Kazi, Abdul Nafey; Naeem, Muhammed

    2014-05-01

    Coronary artery bypass graft surgery relieves angina symptoms and reduces mortality among ischaemic heart disease patients. It remains the gold standard for the treatment of multi-vessel and left main coronary artery disease. It is a well-known fact that internal mammary artery conduits have excellent and long-lasting patency when used for coronary artery bypass grafting. Its supremacy is largely because it prevents atherosclerosis. The old-style internal mammary artery bypass grafting, classically known as pedicle grafting, includes a circular rim of tissue around the graft. Bilateral pedicled internal mammary arteries, especially among diabetic patients, have been reported to cause complications in the sternum like sternal osteomyelitis. In many studies it has been reported that dissection of pedicled internal mammary artery can lead to sternal devascularisation which can lead to higher incidence of infections. Considering the higher incidence of deep sternal infections in patients with double pedicled arterial grafts, dissection of internal mammary artery in skeletonised manner was proposed. In this review, we outline the advantages of skeletonised grafting with respect to incidence of sternal infection, patency rates, blood flow, post-coronary artery bypass graft pain and the length of the graft.

  8. Vascular homograft use in a femoropopliteal rare bacterial infection bypass.

    Science.gov (United States)

    Dainese, Luca; Saccu, Claudio; Zoli, Stefano; Trabattoni, Piero; Guarino, Anna; Cavallero, Annalisa; Spirito, Rita

    2012-12-01

    We report on a patient with a femoropopliteal bypass infected by Kytococcus sedentarius. Treatment consisted of resection of the infected prosthesis with homograft substitution and antibiotic therapy started postoperatively. At 6 months followup, the patient showed no signs of infection and results of laboratory findings were normal.

  9. Combined Open-Heart Coronary Artery Bypass Surgery and ...

    African Journals Online (AJOL)

    CASE DETAILS: A 54-year-old woman suffering from dyspnea, chest pain and decreased left ventricular function (EF=40%) was diagnosed with coronary artery disease (3 vessel disease) and became candidate for coronary artery bypass grafting (CABG). Also, she had multinodular goiter with normal thyroid function test.

  10. Esophageal bypass after failed chemoradiotherapy for unresectable esophageal cancer

    International Nuclear Information System (INIS)

    Matono, Satoru; Tanaka, Toshiaki; Mori, Naoki; Nagano, Takeshi; Fujita, Hiromasa; Shirouzu, Kazuo

    2013-01-01

    Esophageal stenosis and/or fistula often occur after chemoradiotherapy (CRT) for unresectable esophageal cancer. In such patients, an esophageal stent can help achieve oral intake. However an esophageal stent cannot be inserted where there is complete stenosis or where the tumor is located. In such cases, esophageal bypass surgery may be necessary. Here, we investigated the clinical characteristics and outcomes in patients who underwent esophageal bypass surgery in our institution. We reviewed 10 cases of esophageal bypass surgery (gastric tube in 8 cases, colon in 2 cases) after CRT for unresectable esophageal cancer, between 2001 and 2009. There were 5 of stenosis-only cases, 4 fistula-only cases, and 1 case of stenosis and fistula. There were postoperative complications in 5 cases (50%), and all these were treated conservatively and healed. The median survival from surgery to peroral intake was 20 days (range 9-90 days), and the median survival after starting peroral intake was 130 days (range 48-293 days). Esophageal bypass surgery can achieve good performance status and improve peroral intake. (author)

  11. Lysosomal-associated protein multispanning transmembrane 5 gene (LAPTM5 is associated with spontaneous regression of neuroblastomas.

    Directory of Open Access Journals (Sweden)

    Jun Inoue

    Full Text Available BACKGROUND: Neuroblastoma (NB is the most frequently occurring solid tumor in children, and shows heterogeneous clinical behavior. Favorable tumors, which are usually detected by mass screening based on increased levels of catecholamines in urine, regress spontaneously via programmed cell death (PCD or mature through differentiation into benign ganglioneuroma (GN. In contrast, advanced-type NB tumors often grow aggressively, despite intensive chemotherapy. Understanding the molecular mechanisms of PCD during spontaneous regression in favorable NB tumors, as well as identifying genes with a pro-death role, is a matter of urgency for developing novel approaches to the treatment of advanced-type NB tumors. PRINCIPAL FINDINGS: We found that the expression of lysosomal associated protein multispanning transmembrane 5 (LAPTM5 was usually down-regulated due to DNA methylation in an NB cell-specific manner, but up-regulated in degenerating NB cells within locally regressing areas of favorable tumors detected by mass-screening. Experiments in vitro showed that not only a restoration of its expression but also the accumulation of LAPTM5 protein, was required to induce non-apoptotic cell death with autophagic vacuoles and lysosomal destabilization with lysosomal-membrane permeabilization (LMP in a caspase-independent manner. While autophagy is a membrane-trafficking pathway to degrade the proteins in lysosomes, the LAPTM5-mediated lysosomal destabilization with LMP leads to an interruption of autophagic flux, resulting in the accumulation of immature autophagic vacuoles, p62/SQSTM1, and ubiqitinated proteins as substrates of autophagic degradation. In addition, ubiquitin-positive inclusion bodies appeared in degenerating NB cells. CONCLUSIONS: We propose a novel molecular mechanism for PCD with the accumulation of autophagic vacuoles due to LAPTM5-mediated lysosomal destabilization. LAPTM5-induced cell death is lysosomal cell death with impaired autophagy

  12. Lysosomal membrane permeabilization: Carbon nanohorn-induced reactive oxygen species generation and toxicity by this neglected mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mei, E-mail: happy_deercn@163.com [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Zhang, Minfang; Tahara, Yoshio; Chechetka, Svetlana; Miyako, Eijiro [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Iijima, Sumio [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tenpaku, Nagoya 468-8502 (Japan); Yudasaka, Masako, E-mail: m-yudasaka@aist.go.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan)

    2014-10-01

    Understanding the molecular mechanisms responsible for the cytotoxic effects of carbon nanomaterials is important for their future biomedical applications. Carbon nanotubular materials induce the generation of reactive oxygen species (ROS), which causes cell death; however, the exact details of this process are still unclear. Here, we identify a mechanism of ROS generation that is involved in the apoptosis of RAW264.7 macrophages caused by excess uptake of carbon nanohorns (CNHs), a typical type of carbon nanotubule. CNH accumulated in the lysosomes, where they induced lysosomal membrane permeabilization (LMP) and the subsequent release of lysosomal proteases, such as cathepsins, which in turn caused mitochondrial dysfunction and triggered the generation of ROS in the mitochondria. The nicotinamide adenine dinucleotide phosphate oxidase was not directly involved in CNH-related ROS production, and the ROS generation cannot be regulated by mitochondrial electron transport chain. ROS fed back to amplify the mitochondrial dysfunction, leading to the subsequent activation of caspases and cell apoptosis. Carbon nanotubules commonly accumulate in the lysosomes after internalization in cells; however, lysosomal dysfunction has not attracted much attention in toxicity studies of these materials. These results suggest that LMP, a neglected mechanism, may be the primary reason for carbon nanotubule toxicity. - Highlights: • We clarify an apoptotic mechanism of RAW264.7 cells caused by carbon nanohorns. • In the meantime, the mechanism of CNH-induced ROS generation is identified. • LMP is the initial factor of CNH-induced ROS generation and cell death. • Cathepsins work as mediators that connect LMP and mitochondrial dysfunction.

  13. Distinguishing normal cells from cancer cells via lysosome-targetable pH biomarkers with benzo[a]phenoxazine skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Yan-Hua [College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren’Ai Road, Suzhou, 215123 (China); Li, Xiao-Jun [School of Radiation Medicine and Protection, Medicine College of Soochow University, Suzhou, 215123 (China); Sun, Ru, E-mail: sunru924@hotmail.com [College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren’Ai Road, Suzhou, 215123 (China); Xu, Yu-Jie [School of Radiation Medicine and Protection, Medicine College of Soochow University, Suzhou, 215123 (China); Ge, Jian-Feng, E-mail: ge_jianfeng@hotmail.com [College of Chemistry, Chemical Engineering and Material Science, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Soochow University, 199 Ren’Ai Road, Suzhou, 215123 (China); Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163 (China)

    2016-08-24

    In this paper, the design of a lysosome-targetable pH probe that has a fluorescent OFF (pH = 4) to ON (pH = 5–6) response is described to identify lysosomes in normal cells. The mechanism of photoinduced electron transfer with a fluorophore-based reaction (FBR-PET) was proposed. Benzo[a]phenoxazines with electro-donating aryl groups were selected, its (2,5-dimethoxyphenyl)imino-, (2-hydroxyphenyl)imino- and (2-hydroxy-5-methoxyphenyl)- imino-derivatives (probes 1a−c) were prepared and their optical responses towards pH were evaluated; their fluorescence pH titration experiments gave regularly changes with the increasing electro-donating abilities at the linked aryl groups, the (2-hydroxy-5-methoxyphenyl)iminobenzo[a]phenoxazine (probe 1c) exhibited a nearly OFF−ON response at 580–800 nm. All probes were reversible, and they showed excellent selectivity toward the proton over other competitive species. Fluorescence confocal images were performed with HeLa, KB cancer cells and V79 normal cells, probes 1a−c are all lysosome-targetable pH probes, and benzo[a]phenoxazine with (2-hydroxy-5-methoxyphenyl)imino-group (probe 1c) has potential applications in selective differentiation of normal cells from cancer cells. - Highlights: • pH probes for lysosome detection in normal cells. • Differentiation of normal cells from cancer cells by lysosome-biomarker. • The PET mechanism promoted by fluorophore based reactions (FBR-PET).

  14. TGFβ2-INDUCED CHANGES IN LRP-1/TβR-V AND THE IMPACT ON LYSOSOMAL Aβ UPTAKE AND NEUROTOXICITY

    Science.gov (United States)

    Eslami, Pirooz; Johnson, Ming F.; Terzakaryan, Ellen; Chew, Carolyn; Harris-White, Marni E.

    2008-01-01

    Numerous studies suggest a central role for the low-density lipoprotein receptor-related protein/transforming growth factor beta receptor V in Alzheimer’s Disease. We continue our investigation of a ligand for this receptor, transforming growth factor beta2, which is also implicated in Alzheimer Disease pathogenesis, but whose mechanism(s) remain elusive. Confocal imaging reveals that transforming growth factor beta2 rapidly targets amyloid beta peptide to the lysosomal compartment in cortical neurons and induces cell death. Low-density lipoprotein receptor-related protein/transforming growth factor beta receptor V is known as an endocytic receptor, delivering proteins to the lysosomal compartment for degradation. Transforming growth factor beta2 may alter this pathway resulting in increased uptake, intracellular accumulation and toxicity of amyloid beta peptide. RT-PCR and Western blot analysis of transforming growth factor beta2-treated cells demonstrate that transforming growth factor beta2 modestly increases the mRNA and protein levels of low-density lipoprotein receptor-related protein/transforming growth factor beta receptor V as well as increases the uptake activity. Furthermore, transforming growth factor beta2 alters the morphology and numbers of lysosomes in neurons. Lucifer yellow and lysosomal hydrolase analysis show that transforming growth factor beta2 makes lysosomal membranes unstable and leaky and this effect is exacerbated with the addition of amyloid beta protein. Our data support a key role for low-density lipoprotein receptor-related protein/transforming growth factor beta receptor V in mediating transforming growth factor beta2 enhancement of amyloid beta peptide uptake and neurotoxicity. PMID:18804458

  15. [Treatment of aorto-coronary saphenous vein bypass lesions: pros and cons of angioplasty].

    Science.gov (United States)

    Jacq, L; Deleuze, P; Bical, O; Lardoux, H

    2000-08-01

    Heart patients who have undergone a coronary bypass may present with renewed myocardial ischemia, often connected with bypass dysfunction. The saphenous bypass is the most frequently implicated, and palliative revascularization may be envisaged, either by further bypass surgery, or by angioplasty. The latter approach has been developed since the beginning of the 1980s, and since that time there has been considerable technical and pharmacological progress in performing this type of graft. However the indications for angioplasty and its comparison with reoperation remain controversial. In the present study, it therefore seemed pertinent to include the respective opinions of two experts in the field of angioplasty and coronary bypass surgery.

  16. Intraoperative Evaluation of Reverse Bypass Using a Naturally Formed "Bonnet" Superficial Temporal Artery: Technical Note.

    Science.gov (United States)

    Nagm, Alhusain; Horiuchi, Tetsuyoshi; Hasegawa, Takatoshi; Hongo, Kazuhiro

    2016-04-01

    In reverse bypass that used a naturally formed "bonnet" superficial temporal artery, intraoperative volume flow measurement quantifies flow augmentation after revascularization, confirms flow preservation, and identifies inadvertent vessel compromise. A 75-year-old man presented with transient ischemic attacks attributed to right internal carotid artery stenosis. He underwent successful reverse bypass via a naturally formed "bonnet" superficial temporal artery middle cerebral artery bypass. As the result of proper intraoperative volume flow evaluation, a successful reverse bypass was achieved. Modification of the intraoperative stroke risk and prediction of the long-term patency after reverse bypass can be achieved by meticulous intraoperative blood flow evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Cancer in the gastric remnant after gastric bypass: a case report.

    Science.gov (United States)

    Khitin, Lev; Roses, Robert E; Birkett, Desmond H

    2003-01-01

    Gastric cancer in the gastric stump after a Bilroth II subtotal gastrectomy is a well-recognized entity. However, gastric cancer in the bypassed gastric remnant after a gastric bypass operation for morbid obesity has not been well described, and only 2 such cases have been reported in the English literature. This case report presents a patient who developed gastric cancer in the defunctionalized, bypassed stomach 22 years after undergoing an open gastric bypass with a Roux-en-Y gastro-jejunostomy for morbid obesity. The problems of monitoring the defunctionalized bypassed stomach after gastric stapling and gastro-jejunostomy are discussed.

  18. Lysosomal Ca2+ Signaling Regulates High Glucose-Mediated Interleukin-1β Secretion via Transcription Factor EB in Human Monocytic Cells

    Science.gov (United States)

    Tseng, Hisa Hui Ling; Vong, Chi Teng; Kwan, Yiu Wa; Lee, Simon Ming-Yuen; Hoi, Maggie Pui Man

    2017-01-01

    Aberrant activation of the innate immune system, including NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome-dependent interleukin-1β (IL-1β) secretion, has been implicated in the pathogenesis of type 2 diabetes mellitus (T2DM) and its complication. Our previous study demonstrated that hyperglycemia, a hallmark characteristic of T2DM, induced NLRP3 inflammasome-dependent caspase-1 activation and IL-1β maturation in human monocytic cells. In this study, we examined the underlying mechanisms of secreting IL-1β during hyperglycemia, with a focus on the alteration of Ca2+ homeostasis and lysosomal exocytosis. We found that high glucose (HG; 30 mM glucose for 48 h) altered Ca2+ homeostasis by reducing lysosomal Ca2+ concentration that appeared to be resulted from Ca2+ moving out of lysosomes into cytosol in human monocytic cell lines, U937 and THP-1 cells. Moreover, HG-induced lysosomal Ca2+-dependent mature IL-1β release was strongly correlated with the activation and upregulation of two lysosomal marker proteins, cathepsin D and lysosomal-associated membrane protein-1 (LAMP-1). This involved calcineurin/transcription factor EB (TFEB) pathway and its target genes, cathepsin B, cathepsin D, and LAMP-1, to mediate lysosomal exocytosis. Therefore in this study, we revealed a novel mechanism of HG-induced lysosomal exocytosis which was regulated by lysosomal Ca2+ signals through calcineurin/TFEB pathway, thus contributing to IL-1β secretion in human monocytic cells. PMID:28970837

  19. Anesthetic implications of subxiphoid coronary artery bypass surgery.

    Science.gov (United States)

    Chakravarthy, Murali; Veerappa, Muralimanohar; Jawali, Vivek; Pandya, Nischal; Krishnamoorthy, Jayaprakash; Muniraju, Geetha; George, Antony; Baishya, Jitumoni

    2016-01-01

    Minimal invasive surgeries are carried out to benefit the patient with less pain, blood loss, mechanical ventilation and hospital stay; a smaller scar is not the aim. Minimal invasive cardiac surgeries are carried out via small sternotomy, small thoracotomy and via robotic arms. Subxiphoid route is a novel method and avoids sternotomy. This case series is an attempt to understand the anesthetic modifications required. Secondly, whether it is feasible to carry out subxiphoid coronary artery bypass surgery. Elective patients scheduled to undergo subxiphoid coronary artery bypass surgery were chosen. The surgeries were conducted under general anesthesia with left lung isolation via either endobronchial tube or bronchial blocker. We conducted ten (seven males and 3 females) coronary artery bypass graft surgeries via subxiphoid technique. The mean EuroSCORE was 1.7 and the mean ejection fraction was 53.6. Eight patients underwent surgery via endobronchial tube, while, in the remaining two lung isolation was obtained using bronchial blocker. Mean blood loss intraoperatively was 300 ± 42 ml and postoperatively 2000 ± 95 ml. The pain score on the postoperative day '0' was 4.3 ± 0.6 and 2.3 ± 0.7 on the day of discharge. Length of stay in the hospital was 4.8 ± 0.9 days. There were no complications, blood transfusions, conversion to cardiopulmonary bypass. The modifications in the anesthetic and surgical techniques are, use of left lung isolation using either endobronchial tube or bronchial blocker, increased duration for conduit harvesting, grafting, requirement of transesophageal echocardiography monitoring in addition to hemodynamic monitoring. Other minor requirements are transcutaneous pacing and defibrillator pads, a wedge under the chest to 'lift' up the chest, sparing right femoral artery and vein (to serve as vascular access) for an unlikely event of conversion to cardiopulmonary bypass. Any anesthesiologist wishing to start this technique must be aware of

  20. Anesthetic implications of subxiphoid coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Murali Chakravarthy

    2016-01-01

    Full Text Available Background: Minimal invasive surgeries are carried out to benefit the patient with less pain, blood loss, mechanical ventilation and hospital stay; a smaller scar is not the aim. Minimal invasive cardiac surgeries are carried out via small sternotomy, small thoracotomy and via robotic arms. Subxiphoid route is a novel method and avoids sternotomy. Aim: This case series is an attempt to understand the anesthetic modifications required. Secondly, whether it is feasible to carry out subxiphoid coronary artery bypass surgery. Methods: Elective patients scheduled to undergo subxiphoid coronary artery bypass surgery were chosen. The surgeries were conducted under general anesthesia with left lung isolation via either endobronchial tube or bronchial blocker. Results: We conducted ten (seven males and 3 females coronary artery bypass graft surgeries via subxiphoid technique. The mean EuroSCORE was 1.7 and the mean ejection fraction was 53.6. Eight patients underwent surgery via endobronchial tube, while, in the remaining two lung isolation was obtained using bronchial blocker. Mean blood loss intraoperatively was 300 ± 42 ml and postoperatively 2000 ± 95 ml. The pain score on the postoperative day ′0′ was 4.3 ± 0.6 and 2.3 ± 0.7 on the day of discharge. Length of stay in the hospital was 4.8 ± 0.9 days. There were no complications, blood transfusions, conversion to cardiopulmonary bypass. The modifications in the anesthetic and surgical techniques are, use of left lung isolation using either endobronchial tube or bronchial blocker, increased duration for conduit harvesting, grafting, requirement of transesophageal echocardiography monitoring in addition to hemodynamic monitoring. Other minor requirements are transcutaneous pacing and defibrillator pads, a wedge under the chest to ′lift′ up the chest, sparing right femoral artery and vein (to serve as vascular access for an unlikely event of conversion to cardiopulmonary bypass. Any

  1. EARLY POSTOPERATIVE COMPLICATIONS IN ROUX-EN-Y GASTRIC BYPASS.

    Science.gov (United States)

    Stoll, Aluisio; Rosin, Leandro; Dias, Mariana Fernandes; Marquiotti, Bruna; Gugelmin, Giovana; Stoll, Gabriela Fanezzi

    Roux-en-Y gastric bypass is one of the most common bariatric surgery and leads to considerable weight loss in the first months. To quantify the main early postoperative complications in patients submitted to the gastric bypass. Observational retrospective cohort. Data of 1051 patients with class II obesity associated with comorbidities or class III obesity submitted to the gastric bypass with 30 days of follow-up starting from the date of the surgery. The age average was 36 years with a predominance of females (81.1%). The mean preoperative body mass index was 43 kg/m². The major complication was fistula (2.3%), followed by intestinal obstruction (0.5%) and pulmonary embolism (0.5%). Death occurred in 0.6% of the cases. In the period of 30 days after surgery the overall complication rate was 3.8%; reoperation was necessary in 2.6% and death occurred in 0.6%. Fistula was the main complication and the leading cause of hospitalization in intensive care unit, reoperation and death. Bypass gástrico em Y-de-Roux é uma das operações bariátricas mais comuns e leva a perdas consideráveis de peso já nos primeiros meses. Quantificar as principais complicações pós-operatórias precoces em pacientes submetidos ao bypass gástrico. Coorte retrospectiva observacional. Amostra de 1051 pacientes portadores de obesidade grau II associada à comorbidades ou grau III submetidos ao bypass gástrico com acompanhamento de 30 dias a partir da data da operação. A idade média dos pacientes foi de 36 anos com predominância de mulheres (81,1%). O índice de massa corporal pré-operatório médio foi de 43 kg/m². A principal complicação foi fístula (2,3%), seguida de obstrução intestinal (0,5%) e tromboembolismo pulmonar (0,5%). Óbito ocorreu em 0,6% dos casos. No período de 30 dias de pós-operatório a taxa geral de complicações foi de 3,8%; a de reoperação de 2,6% e óbito em 0,6%. A fístula foi a principal complicação e a principal causa de internamento em

  2. Inspired by nonenveloped viruses escaping from endo-lysosomes: a pH-sensitive polyurethane micelle for effective intracellular trafficking

    Science.gov (United States)

    Song, Nijia; Zhou, Lijuan; Li, Jiehua; Pan, Zhicheng; He, Xueling; Tan, Hong; Wan, Xinyuan; Li, Jianshu; Ran, Rong; Fu, Qiang

    2016-03-01

    A multifunctional drug delivery system (DDS) for cancer therapy still faces great challenges due to multiple physiological barriers encountered in vivo. To increase the efficacy of current cancer treatment a new anticancer DDS mimicking the response of nonenveloped viruses, triggered by acidic pH to escape endo-lysosomes, is developed. Such a smart DDS is self-assembled from biodegradable pH-sensitive polyurethane containing hydrazone bonds in the backbone, named pHPM. The pHPM exhibits excellent micellization characteristics and high loading capacity for hydrophobic chemotherapeutic drugs. The responses of the pHPM in acidic media, undergoing charge conversion and hydrophobic core exposure, resulting from the detachment of the hydrophilic polyethylene glycol (PEG) shell, are similar to the behavior of a nonenveloped virus when trapped in acidic endo-lysosomes. Moreover, the degradation mechanism was verified by gel permeation chromatography (GPC). The endo-lysosomal membrane rupture induced by these transformed micelles is clearly observed by transmission electron microscopy. Consequently, excellent antitumor activity is confirmed both in vitro and in vivo. The results verify that the pHPM could be a promising new drug delivery tool for the treatment of cancer and other diseases.A multifunctional drug delivery system (DDS) for cancer therapy still faces great challenges due to multiple physiological barriers encountered in vivo. To increase the efficacy of current cancer treatment a new anticancer DDS mimicking the response of nonenveloped viruses, triggered by acidic pH to escape endo-lysosomes, is developed. Such a smart DDS is self-assembled from biodegradable pH-sensitive polyurethane containing hydrazone bonds in the backbone, named pHPM. The pHPM exhibits excellent micellization characteristics and high loading capacity for hydrophobic chemotherapeutic drugs. The responses of the pHPM in acidic media, undergoing charge conversion and hydrophobic core

  3. Role of autophagy and lysosomal drug sequestration in acquired resistance to doxorubicin in MCF-7 cells

    International Nuclear Information System (INIS)

    Guo, Baoqing; Tam, Adam; Santi, Stacey A.; Parissenti, Amadeo M.

    2016-01-01

    The roles and mechanisms involved in starvation-induced autophagy in mammalian cells have been extensively studied. However, less is known about the potential role for autophagy as a survival pathway in acquired drug resistance in cancer cells under nutrient-rich conditions. We selected MCF-7 breast tumor cells for survival in increasing concentrations of doxorubicin and assessed whether the acquisition of doxorubicin resistance was accompanied by changes in doxorubicin and lysosome localization and the activation of autophagy, as assessed by laser scanning confocal microscopy with or without immunohistochemical approaches. The ultrastructure of cells was also viewed using transmission electron microscopy. Cellular levels of autophagy and apoptosis-related proteins were assessed by immunoblotting techniques, while protein turnover was quantified using a flux assay. As cells acquired resistance to doxorubicin, the subcellular location of the drug moved from the nucleus to the perinuclear region. The location of lysosomes and autophagosomes also changed from being equally distributed throughout the cytoplasm to co-localizing with doxorubicin in the perinuclear region. There was an apparent temporal correlation between the acquisition of doxorubicin resistance and autophagy induction, as measured by increases in monodansylcadaverine staining, LC3-II production, and co-localization of LAMP1 and LC3-II immunofluorescence. Electron microscopy revealed an increase in cytoplasmic vacuoles containing mitochondria and other cellular organelles, also suggestive of autophagy. Consistent with this view, a known autophagy inhibitor (chloroquine) was highly effective in restoring doxorubicin sensitivity in doxorubicin-resistant cells. Moreover, this induction of autophagy correlated temporally with increased expression of the selective cargo receptor p62, which facilitates the delivery of doxorubicin-damaged mitochondria and other organelles to autophagosomes. Finally, we suggest

  4. Changes in Reward after Gastric Bypass: the Advantages and Disadvantages.

    Science.gov (United States)

    Scholtz, Samantha; Goldstone, Anthony P; le Roux, Carel W

    2015-10-01

    Gastric bypass surgery is an effective long-term weight loss intervention. Key to its success appears a putative shift in food preference away from high-energy-density foods associated with a reduced appetitive drive and loss of neural reactivity in the reward system of the brain towards food. Post-prandial exaggerated satiety gut hormone responses have been implicated as mediators. Whilst the positive impact of bariatric surgery on both physical and psychological outcomes for many patients is clearly evident, a subset of patients appear to be detrimentally affected by this loss of reward from food and by a lack of alternative strategies for regulating affect after surgery. Mindfulness training has emerged as a potential tool in reducing the need for immediate reward that underpins much of eating behaviour. Further research is needed to help identify patients who may be more vulnerable after gastric bypass and which forms of support may be most beneficial.

  5. Management of broken instrument by file bypass technique

    Directory of Open Access Journals (Sweden)

    Sultana Parveen

    2017-02-01

    Full Text Available Different devices and techniques have been developed to retrieve fractured instruments during the endodontic procedures. This case report describes the management of a broken instrument, which was accidentally broken during cleaning and shaping of the root canal in right 2nd molar tooth. A # 25 stainless steel K-file was separated in mesiobuccal canal of the treated tooth. At first, a radiograph was taken to confirm the level of separation of the instrument. The instrument was found to be separated at the apical 3rd of the mesial canal and then file bypass technique was performed. Calcium hydroxide dressing was given for 7 days followed by obturation with guttapercha cone and zinc oxide eugenol sealer in lateral condensation technique. It can be concluded that bypass technique can be considered as simple and effective technique for the management of broken instrument into the root canal.

  6. Aorto-aortic intrathoracic bypass in surgical treatment of aortic

    International Nuclear Information System (INIS)

    Gutierrez Perez, F.; Duran Reyes, A.; Bigalli, D.; Filgueira Berobide, J.

    1998-01-01

    The prevalence of coarctation of the aorta is 6.5 percent of all congenital heart defects, according to national and international data. There is a restenosis rate of patients after surgery. Factors that influence this evolution depends on the age at which patients underwent surgery for the first time the anatomy of the aortic arch and type of surgical technique. Several procedures can be used to correct the coarctation, which include surgery and balloon catheter dilation. We present here a case of a patient of 22 years old, with a recurrent coarctation of the aorta studied by echocardiography and magnetic resonance imaging. The patient underwent surgery a third time. We used an anterior approach (median sternotomy) and performed an aortic bypass graft, intrathoracic, under cardiopulmonary bypass. Evolved favorably and was discharged on the sixth day of post operative day (Author) [es

  7. In situ saphenous vein bypass surgery in diabetic patients

    DEFF Research Database (Denmark)

    Jensen, L P; Schroeder, T V; Lorentzen, J E

    1992-01-01

    .005). Indication for surgery was gangrene or ulceration in 57% of diabetics, as opposed to 36% in non-diabetic patients (p = 0.0002). A femoro-popliteal bypass was performed in 18% of patients, whereas 82% received an infrapopliteal procedure, of which 42% were to the distal third of the calf or foot. Diabetic......From 1986 through to 1990 a total of 483 consecutive in situ infra-inguinal vein bypass procedures were performed in 444 patients, of whom 112 (25%) were diabetics (57 insulin dependent diabetes mellitus and 55 non-insulin-dependent diabetes mellitus). Based on a prospective vascular data registry...... this material was analysed to determine the influence of diabetes on the outcome. Preoperative risk factors were equally distributed among diabetic and non-diabetic patients, except for smoking habits (diabetics: 48%; non-diabetics: 64%, p = 0.002) and cardiac disease (diabetics: 45%; non-diabetics: 29%, p = 0...

  8. Pharmacological Bypass of Cockayne Syndrome B Function in Neuronal Differentiation

    Directory of Open Access Journals (Sweden)

    Yuming Wang

    2016-03-01

    Full Text Available Cockayne syndrome (CS is a severe neurodevelopmental disorder characterized by growth abnormalities, premature aging, and photosensitivity. Mutation of Cockayne syndrome B (CSB affects neuronal gene expression and differentiation, so we attempted to bypass its function by expressing downstream target genes. Intriguingly, ectopic expression of Synaptotagmin 9 (SYT9, a key component of the machinery controlling neurotrophin release, bypasses the need for CSB in neuritogenesis. Importantly, brain-derived neurotrophic factor (BDNF, a neurotrophin implicated in neuronal differentiation and synaptic modulation, and pharmacological mimics such as 7,8-dihydroxyflavone and amitriptyline can compensate for CSB deficiency in cell models of neuronal differentiation as well. SYT9 and BDNF are downregulated in CS patient brain tissue, further indicating that sub-optimal neurotrophin signaling underlies neurological defects in CS. In addition to shedding light on cellular mechanisms underlying CS and pointing to future avenues for pharmacological intervention, these data suggest an important role for SYT9 in neuronal differentiation.

  9. Transfusion practice in coronary artery bypass surgery in Denmark

    DEFF Research Database (Denmark)

    Andreasen, Jan J.; Westen, Mikkel; Pallesen, Peter Appel

    2007-01-01

    Transfusion rates in coronary artery bypass grafting (CABG) continue to vary substantially, although guidelines for allogeneic transfusion have been developed. In order to evaluate ongoing transfusion practices, we performed a multicenter audit in four Danish hospitals regarding the use of alloge......Transfusion rates in coronary artery bypass grafting (CABG) continue to vary substantially, although guidelines for allogeneic transfusion have been developed. In order to evaluate ongoing transfusion practices, we performed a multicenter audit in four Danish hospitals regarding the use......-related factors. Interesting differences in transfusion rates exists in Danish hospitals and these differences may reflect true variations in transfusion practices. Audits create a basis for educational efforts among surgeons and anesthesiologists to standardize transfusion practices...

  10. Concomitant Thoracic Aortobifemoral Bypass With Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Bishawi, Muath; Shah, Asad A; McCann, Richard L; Milano, Carmelo A

    2016-11-01

    Improved quality of life for patients after left ventricular assist device (LVAD) implantation can be greatly limited by peripheral vascular disease even if heart failure symptoms are resolved by LVAD support. We present a case of concomitant thoracic aortobifemoral bypass and LVAD implantation in a patient with ischemic cardiomyopathy, severe peripheral vascular disease, and multiple previous failed revascularization attempts. In this patient, we used the LVAD outflow to provide the inflow to the femoral artery bypass graft. This graft has remained patent at a 2-year follow-up, without claudication symptoms. Performing concomitant major vascular operations safely and successfully is feasible in patients with LVADs. Quality of life after ventricular assist device placement can be limited by vascular disease, but it can be markedly improved after vascular surgical intervention. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Achalasia 5 years following Roux-en-y gastric bypass

    OpenAIRE

    Torghabeh, Mehyar Hefazi; Afaneh, Cheguevara; Saif, Taha; Dakin, Gregory F.

    2015-01-01

    Oesophageal achalasia is a rare, but serious condition in which the motility of the lower oesophageal sphincter (LES) is inhibited. This disorder of idiopathic aetiology complicates the peristaltic function and relaxation of the LES that may cause symptoms such as dysphagia, epigastric pain, and regurgitation of an obstructed food. The following case describes achalasia in a patient 5 years following a laparoscopic Roux-en-Y gastric bypass (RYGB). The patient underwent a laparoscopic Heller m...

  12. Protective effect of dexmedetomidine in coronary artery bypass grafting surgery

    OpenAIRE

    REN, JIANJUN; ZHANG, HUIJUN; HUANG, LINING; LIU, YUE; LIU, FENGQIN; DONG, ZHENMING

    2013-01-01

    The aim of this study was to observe the impact of dexmedetomidine on postoperative myocardial injury in patients undergoing off-pump coronary artery bypass (OPCAB) grafting. One hundred and sixty-two patients who were undergoing OPCAB surgery were randomly divided into control and dexmedetomidine groups (groups C and Dex, respectively). Following the first vascular anastomosis grafting, the patients in group Dex received a continuous intravenous infusion of 0.2?0.5 ?g/kg/h dexmedetomidine, u...

  13. Evaluation of a primary care paramedic STEMI bypass guideline.

    Science.gov (United States)

    Kwong, Jonathan L; Ross, Garry; Turner, Linda; Olynyk, Chris; Cheskes, Sheldon; Thurston, Adam; Verbeek, P Richard

    2017-11-20

    Limited evidence supports primary care paramedic (PCP) direct transport of ST-segment elevation myocardial infarction (STEMI) patients for percutaneous coronary intervention (PCI). The goal of this study was to evaluate an urban-based PCP STEMI bypass guideline. We reviewed consecutive Toronto Paramedic Services call reports between April 7, 2015, and May 31, 2016, regarding STEMI patients identified by PCPs. The primary outcome was patient assignment (stable versus unstable) according to guideline criteria. Secondary outcomes were the proportion of PCP-transported patients who had an indication for an advanced care intervention (ACI) or who received an ACI when PCPs rendezvoused with an advanced care paramedic (ACP). Lastly, we reviewed prehospital outcomes of cardiac arrest patients and calculated the difference in transport intervals between direct PCP bypass and a PCI-centre and predicted transport interval to the closest emergency department (ED). Of 361 patients, 232 were PCP transports and 129 were ACP-rendezvous transports. There was a significant difference in the distribution of stable and unstable patients between PCPs and ACPs (p<0.001). For PCP patients, 21/232 (9.1%) had indications for an ACI, whereas 34/129 (26.4%) ACP patients received an ACI. Eleven patients experienced cardiac arrest; 10 were successfully resuscitated (5 of these by PCPs). The median difference between direct PCP bypass and a PCI-centre versus transport to the closest ED was 5.53 minutes (IQR=6.71). We found a significant difference in the distribution of stable and unstable patients and fewer patients with indications for an ACI in PCP patients. This PCP STEMI bypass guideline appears feasible.

  14. Constitutive modeling of coronary artery bypass graft with incorporated torsion

    Czech Academy of Sciences Publication Activity Database

    Horný, L.; Chlup, Hynek; Žitný, R.; Adámek, T.

    2009-01-01

    Roč. 49, č. 2 (2009), s. 273-277 ISSN 0543-5846 R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : coronary artery bypass graft * constitutive model * digital image correlation Subject RIV: BJ - Thermodynamics Impact factor: 0.439, year: 2009 http://web.tuke.sk/sjf-kamam/mmams2009/contents.pdf

  15. Tuberculosis after jejuno-ileal bypass for morbid obesity.

    OpenAIRE

    Werbin, N.

    1981-01-01

    A patient contracted tuberculosis after 2 operations for morbid obesity. The difficulty in diagnosis and treatment is described. Jejuno-ileal bypass is a non-physiological operation, with many reported complications and side effects. Following this short experience the author and his colleagues have now abandoned this operation. Patients suffering from malnutrition as a result of slimming operations should be carefully monitored for tuberculosis.

  16. Experiences with the Montgomery Salivary Bypass Tube (MSBT)

    Science.gov (United States)

    Lörken, A; Krampert, J; Kau, R J; Arnold, W

    1997-01-01

    Patients with hypopharyngeal and cervical esophageal strictures and fistulas caused by advanced malignancy, ingestion of caustic material, or following surgery or radiation therapy often suffer from marked dysphagia. In such cases the implantation of a Montgomery Salivary Bypass Tube (MSBT) can be an effective therapeutic option to bridge the fistulous tract or bypass a stenosis. Being able to eat and drink without the need for intravenous supplementation or nasogastric or gastrostomy tube feeding in general greatly improves the patient's quality of life. Since 1981 we have successfully inserted the MSBT in 44 cases suffering from dysphagia of different etiology. Our experiences with the indications for implantation, insertion techniques, and postoperative results are presented. Three selected cases of progressive dysphagia in which the MSBT is demonstrated to be the treatment of choice are described in more detail. In one case, a tracheoesophageal fistula and in another a stricture of the upper esophageal sphincter (UES) were bypassed so that oral intake of soft food became possible again. The third patient suffered from a disturbance of the esophageal motility after resection of a Hippel-Lindau tumor in the spinal cord and syringe drainage; even swallowing saliva was impeded. After insertion of a MSBT, uncomplicated soft food intake became possible again.

  17. Augmented reality-assisted bypass surgery: embracing minimal invasiveness.

    Science.gov (United States)

    Cabrilo, Ivan; Schaller, Karl; Bijlenga, Philippe

    2015-04-01

    The overlay of virtual images on the surgical field, defined as augmented reality, has been used for image guidance during various neurosurgical procedures. Although this technology could conceivably address certain inherent problems of extracranial-to-intracranial bypass procedures, this potential has not been explored to date. We evaluate the usefulness of an augmented reality-based setup, which could help in harvesting donor vessels through their precise localization in real-time, in performing tailored craniotomies, and in identifying preoperatively selected recipient vessels for the purpose of anastomosis. Our method was applied to 3 patients with Moya-Moya disease who underwent superficial temporal artery-to-middle cerebral artery anastomoses and 1 patient who underwent an occipital artery-to-posteroinferior cerebellar artery bypass because of a dissecting aneurysm of the vertebral artery. Patients' heads, skulls, and extracranial and intracranial vessels were segmented preoperatively from 3-dimensional image data sets (3-dimensional digital subtraction angiography, angio-magnetic resonance imaging, angio-computed tomography), and injected intraoperatively into the operating microscope's eyepiece for image guidance. In each case, the described setup helped in precisely localizing donor and recipient vessels and in tailoring craniotomies to the injected images. The presented system based on augmented reality can optimize the workflow of extracranial-to-intracranial bypass procedures by providing essential anatomical information, entirely integrated to the surgical field, and help to perform minimally invasive procedures. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Reducing family stress during and after coronary artery bypass surgery.

    Science.gov (United States)

    Gilliss, C L

    1984-03-01

    Based on the findings of this study of couples after coronary artery bypass surgery, there are numerous stresses and unmet needs that might be addressed by hospital-based nurses. The study demonstrated that, as a group, the spouses of the bypass patients report higher levels of stress than the patients did while in the hospital. Together, patients and spouses reported high levels of marital conflict, dissatisfaction, and discord during the first 6 months after the surgery. Many indicated that they were unprepared for these experiences. Further, they found it difficult to maintain continuity with a provider who could answer their questions about recovery. As a result of these findings a program of nursing care that focuses on the family during and after coronary artery bypass surgery has been proposed. The model program consists of preparation for surgery, preparation for discharge, and continuous contact with the family after discharge, at least through the first follow-up appointment with the surgeon at 6 weeks. For each phase it is necessary to consider content that is appropriate to the individual patient, but it is essential to include content aimed at reducing the stresses and risk experienced by the family as well. By doing so hospital-based nurses are treating the family as well as nursing the patient through this episode of acute illness.

  19. Carotid disease in diabetic patients undergoing coronary artery bypass grafting

    International Nuclear Information System (INIS)

    Shahid, M.; Abid, A.R.; Dar, M.A.; Noeman, A.; Amin, S.; Azhar, M.

    2012-01-01

    Objective: To compare the severity of carotid artery disease in diabetic and non-diabetic patients undergoing coronary artery bypass grafting. Methods: From January to June 2008, 379 patients undergoing elective coronary artery bypass surgery were preoperatively evaluated for the presence of carotid stenoses by duplex scanning. Patients were divided into two groups, Group I, 156 (41.2%) diabetic patients and Group II, 223 (58.8%) non-diabetic patients. Results: There were 314 (82.8%) males and 65 (17.2%) females with a mean age of 57.2+-9.1 years. In diabetic group there were 125 (80.1%) males and 31 (19.9%) females with a mean age of 56.3+-8.9 years. Left main stem stenosis was present in 59 (37.8%) diabetics and 45 (20.2%) non-diabetics (p 70% stenosis was present in 20 (5.3%) with 13 (8.3%) diabetics and 7 (3.1%) non-diabetics (p<0.025). Stenosis of 50-70% was observed in 30 (7.9%) of which 17 (10.9%) were diabetics and 13 (5.8%) were non-diabetics. Conclusion: Presence of diabetes mellitus is associated with diffuse coronary artery disease and significant carotid artery disease in patients undergoing coronary artery bypass grafting. (author)

  20. Beta-adrenergic antagonist propranolol inhibits mammalian cell lysosome spreading and invasion by Trypanosoma cruzi metacyclic forms.

    Science.gov (United States)

    Macedo, Silene; Rodrigues, João Paulo Ferreira; Schenkman, Sergio; Yoshida, Nobuko

    The involvement of β-adrenergic receptor (β-AR) in host cell invasion by Trypanosoma cruzi metacyclic trypomastigote (MT) is not known. We examined whether isoproterenol, an agonist of β-AR, or nonselective β-blocker propranolol affected MT internalization mediated the stage-specific surface molecule gp82. Treatment of HeLa cells with propranolol significantly inhibited MT invasion whereas isoproterenol had no effect. Propranolol, but not isoproterenol, also inhibited the lysosome spreading required for gp82-dependent MT invasion. The effect of propranolol in inhibiting MT internalization was not due to the prevention of gp82 interaction with β-AR. It was mainly associated with its ability to impair lysosome spreading. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  1. Effects of sub-lethal dose of γ-irradiation on lysosomal enzymes in tissue of pigeon

    International Nuclear Information System (INIS)

    Shah, V.C.; Gadhia, P.K.

    1979-01-01

    Effects of total body γ-irradiation with sub-lethal dose (300 rad) on three lysosomal enzymes namely acid phosphatase, ribonuclease-II and deoxyribonuclease-II have been studied in pigeons. Liver, kidney and spleen were the tissues studied at different intervals like 1-h, 24-h, 48-h, and 72-h of irradiation. The specific activities ('crude' fraction) of acid phosphatase and ribonuclease-II increased significantly in spleen and liver at 48-h of irradiation. The activity of deoxyribonuclease-II in liver and spleen was increased only at 72-h post-irradiation. On the other hand, the total activities of three lysosomal enzymes did not show remarkable change throughout 72-h of irradiation. (author)

  2. Overexpression of SNX7 reduces Aβ production by enhancing lysosomal degradation of APP.

    Science.gov (United States)

    Xu, Shaohua; Zhang, Lu; Brodin, Lennart

    2018-01-01

    Abnormal production of amyloid-β peptides (Aβ) by proteolytic processing of amyloid precursor protein (APP) is thought to be central to the pathogenesis of Alzheimer's disease (AD). Although many efforts have been made to investigate mechanisms that regulate APP processing, many details remain incompletely understood. Sorting nexins (SNXs) are a family of proteins which are involved in many intracellular trafficking events. Several SNXs have been implicated in APP processing and Aβ production. In this study, we extended the investigation to SNX7. We found that overexpression of SNX7 in HEK293T cells reduces the levels of secreted Aβ and β-cleaved N-terminal APP fragments (sAPPβ). Moreover, SNX7 overexpression caused a significant reduction of the steady-state levels of APP as well as of the cell surface APP levels. By using NH 4 Cl and Bafilomycin A1 to inhibit the lysosomal degradative pathway, we found that the reduction of APP induced by SNX7 overexpression was prevented by such inhibition. No change in the cell surface distribution or steady-state levels of BACE1 was detected after overexpression of SNX7. Taken together, these results suggest that SNX7 regulates Aβ production by directing APP for degradation. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. High proportion of mannosidosis and fucosidosis among lysosomal storage diseases in Cuba.

    Science.gov (United States)

    Menéndez-Sainz, C; González-Quevedo, A; González-García, S; Peña-Sánchez, M; Giugliani, R

    2012-08-13

    Although lysosomal storage disorders (LSDs) are considered individually rare, as a group they present a non-negligible frequency. Few studies have been made of populational occurrence of LSDs; they have been conducted predominantly on Caucasian populations. We studied the occurrence of LSDs in Cuba. Data from individuals who had been referred to the Institute of Neurology and Neurosurgery in Havana from hospitals all over the country between January 1990 and December 2005 were analyzed. This institute was the only laboratory to provide enzyme-based diagnostic testing for 19 LSDs in Cuba during this period. Occurrence rates were calculated by dividing the number of postnatal diagnoses by the number of births during the study period. The combined occurrence of LSDs in Cuba was 5.6 per 100,000, lower than that reported in other studies conducted on Caucasian populations. The most frequent individual LSDs were: mucopolysaccharidosis type I (1.01 per 100,000) and, surprisingly, alpha-mannosidosis (0.72 per 100,000) and fucosidosis (0.62 per 100,000). These findings may be related to specific genetic characteristics and admixture of the Cuban population. This is the first comprehensive study of the occurrence of LSDs in Cuba. We conclude that the epidemiology of these diseases can vary regionally, and we stress the need for similar surveys in other Latin American countries.

  4. Formation of distinct inclusion bodies by inhibition of ubiquitin-proteasome and autophagy-lysosome pathways

    International Nuclear Information System (INIS)

    Lee, Junho; Yang, Kyu-Hwan; Joe, Cheol O.; Kang, Seok-Seong

    2011-01-01

    Research highlights: → Distinct inclusion bodies are developed by inhibition of UPP and ALP. → The inclusion bodies differ in morphology, localization and formation process. → The inclusion bodies are distinguishable by the localization of TSC2. → Inhibition of both UPP and ALP simultaneously induces those inclusion bodies. -- Abstract: Accumulation of misfolded proteins is caused by the impairment of protein quality control systems, such as ubiquitin-proteasome pathway (UPP) and autophagy-lysosome pathway (ALP). In this study, the formation of inclusion bodies was examined after the blockade of UPP and/or ALP in A549 cells. UPP inhibition induced a single and large inclusion body localized in microtubule-organizing center. Interestingly, however, ALP inhibition generated dispersed small inclusion bodies in the cytoplasm. Tuberous sclerosis complex 2 was selectively accumulated in the inclusion bodies of UPP-inhibited cells, but not those of ALP-inhibited cells. Blockade of transcription and translation entirely inhibited the formation of inclusion body induced by UPP inhibition, but partially by ALP inhibition. Moreover, the simultaneous inhibition of two protein catabolic pathways independently developed two distinct inclusion bodies within a single cell. These findings clearly demonstrated that dysfunction of each catabolic pathway induced formation and accumulation of unique inclusion bodies on the basis of morphology, localization and formation process in A549 cells.

  5. Formation of distinct inclusion bodies by inhibition of ubiquitin-proteasome and autophagy-lysosome pathways.

    Science.gov (United States)

    Lee, Junho; Yang, Kyu-Hwan; Joe, Cheol O; Kang, Seok-Seong

    2011-01-14

    Accumulation of misfolded proteins is caused by the impairment of protein quality control systems, such as ubiquitin-proteasome pathway (UPP) and autophagy-lysosome pathway (ALP). In this study, the formation of inclusion bodies was examined after the blockade of UPP and/or ALP in A549 cells. UPP inhibition induced a single and large inclusion body localized in microtubule-organizing center. Interestingly, however, ALP inhibition generated dispersed small inclusion bodies in the cytoplasm. Tuberous sclerosis complex 2 was selectively accumulated in the inclusion bodies of UPP-inhibited cells, but not those of ALP-inhibited cells. Blockade of transcription and translation entirely inhibited the formation of inclusion body induced by UPP inhibition, but partially by ALP inhibition. Moreover, the simultaneous inhibition of two protein catabolic pathways independently developed two distinct inclusion bodies within a single cell. These findings clearly demonstrated that dysfunction of each catabolic pathway induced formation and accumulation of unique inclusion bodies on the basis of morphology, localization and formation process in A549 cells. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Wnt Signaling Translocates Lys48-Linked Polyubiquitinated Proteins to the Lysosomal Pathway

    Directory of Open Access Journals (Sweden)

    Hyunjoon Kim

    2015-05-01

    Full Text Available Cellular proteins are degraded in either proteasomes or lysosomes depending on the types of ubiquitin chains that covalently modify them. It is not known whether the choice between these two pathways is physiologically regulated. The Lys48-polyubiquitin chain is the major signal directing proteins for degradation in proteasomes. Here, we report the unexpected finding that canonical Wnt signaling translocates some K48-linked polyubiquitinated proteins to the endolysosomal pathway. Proteasomal target proteins, such as β-catenin, Smad1, and Smad4, were targeted into endolysosomes in a process dependent on GSK3 activity. Relocalization was also dependent on Axin1 and the multivesicular body (MVB proteins HRS/Vps27 and Vps4. The Wnt-induced accumulation of K48-linked polyubiquitinated proteins in endolysosomal organelles was accompanied by a transient decrease in cellular levels of free mono-ubiquitin, which may contribute to Wnt-regulated stabilization of proteins (Wnt/STOP. We conclude that Wnt redirects Lys48-polyubiquitinated proteins that are normally degraded in proteasomes to endolysosomes.

  7. Efficacy of Kefir on the Release of Lysosomal Proteases After Expremintal Spinal Cord Trauma

    Directory of Open Access Journals (Sweden)

    Emre Delen

    2015-11-01

    Full Text Available Aim: Prevention of secondary injury developing as a result of spinal cord injury will reduce significantly neurological deficits which may occur after trauma. These are focused in experimental studies and many agents are being tested. In our study, we have invesitigated the effects of kefir, which is a a probiotic, associated with life prolongation, whose antioxidant and lipid peroxidation effects were revealed on despite the scientific studies were limited, on lipid peroxidation and lysosomal proteases which play important roles in spinal cord. Material and Method: In the study, female Sprague Dawley rats weighing 200 to 250 g were used. The study was conducted on five groups with a total of 40 rats including the control, trauma, trauma treatment, trauma treatment kefir and trauma kefir groups. The high-dose methylprednisolone was used as the therapy. Spinal cord trauma was performed with clip compression method at the level of T10. Kefir was given to rats via orogastric ways, prior to trauma for 7 days at a dose of 2 * 1cc/100g. All rats were sacrificed 48 hours after treatment. The changes in the value of tissue cathepsins B and L, MDA and histopathological changes were examined. Results: It has been found in our study according to the review of biochemical values that; kefir did not reduce significantly cathepsin B values compared to the treatment group (p> 0.05, did reduce significantly MDA value compared to treatment group (p

  8. Ocular manifestations and management recommendations of lysosomal storage disorders I: mucopolysaccharidoses

    Directory of Open Access Journals (Sweden)

    Fenzl CR

    2015-09-01

    Full Text Available Carlton R Fenzl,1 Kyla Teramoto,2 Majid Moshirfar3 1John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2John A Burns School of Medicine, University of Hawai’i, Honolulu, HI, USA; 3Cornea and Refractive Surgery Division, Department of Ophthalmology, Francis I. Proctor Foundation, University of California, San Francisco, CA, USA Abstract: The mucopolysaccharidoses (MPS are a group of lysosomal storage disorders caused by inborn errors of glycosaminoglycan (GAG metabolism. These diseases are classified by enzyme deficiency into seven groups: type I, II, III, IV, VI, VII, and IX. GAG accumulation leads to characteristic clinical features. Some ophthalmic findings that are characteristic of MPS diseases include corneal clouding, retinal degeneration, decreased electroretinogram wave amplitude, optic atrophy, papilledema, and glaucoma. Current treatments such as hematopoietic stem cell transplantation and enzyme replacement therapy have increased the life span of many MPS patients and created the need to improve management of ocular symptoms. This article aims to provide a comprehensive review of ocular manifestations and treatment options for the various types of MPS. Keywords: MPS, glycosaminoglycan, corneal clouding

  9. Mechanism of Aloe Vera extract protection against UVA: shelter of lysosomal membrane avoids photodamage.

    Science.gov (United States)

    Rodrigues, Daniela; Viotto, Ana Cláudia; Checchia, Robert; Gomide, Andreza; Severino, Divinomar; Itri, Rosangela; Baptista, Maurício S; Martins, Waleska Kerllen

    2016-03-01

    The premature aging (photoaging) of skin characterized by wrinkles, a leathery texture and mottled pigmentation is a well-documented consequence of exposure to sunlight. UVA is an important risk factor for human cancer also associated with induction of inflammation, immunosuppression, photoaging and melanogenesis. Although herbal compounds are commonly used as photoprotectants against the harmful effects of UVA, the mechanisms involved in the photodamage are not precisely known. In this study, we investigated the effects of Aloe Vera (Aloe barbadensis mil) on the protection against UVA-modulated cell killing of HaCaT keratinocytes. Aloe Vera exhibited the remarkable ability of reducing both in vitro and in vivo photodamage, even though it does not have anti-radical properties. Interestingly, the protection conferred by Aloe Vera was associated with the maintenance of membrane integrity in both mimetic membranes and intracellular organelles. The increased lysosomal stability led to a decrease in lipofuscinogenesis and cell death. This study explains why Aloe Vera extracts offer protection against photodamage at a cellular level in both the UV and visible spectra, leading to its beneficial use as a supplement in protective dermatological formulations.

  10. Radiological and clinical characterization of the lysosomal storage disorders: non-lipid disorders.

    Science.gov (United States)

    Parker, E I; Xing, M; Moreno-De-Luca, A; Harmouche, E; Terk, M R

    2014-01-01

    Lysosomal storage diseases (LSDs) are a large group of genetic metabolic disorders that result in the accumulation of abnormal material, such as mucopolysaccharides, glycoproteins, amino acids and lipids, within cells. Since many LSDs manifest during infancy or early childhood, with potentially devastating consequences if left untreated, timely identification is imperative to prevent irreversible damage and early death. In this review, the key imaging features of the non-lipid or extralipid LSDs are examined and correlated with salient clinical manifestations and genetic information. Disorders are stratified based on the type of excess material causing tissue or organ dysfunction, with descriptions of the mucopolysaccharidoses, mucolipidoses, alpha-mannosidosis, glycogen storage disorder II and cystinosis. In addition, similarities and differences in radiological findings between each of these LSDs are highlighted to facilitate further recognition. Given the rare and extensive nature of the LSDs, mastery of their multiple clinical and radiological traits may seem challenging. However, an understanding of the distinguishing imaging characteristics of LSDs and their clinical correlates may allow radiologists to play a key role in the early diagnosis of these progressive and potentially fatal disorders.

  11. Lysosomal Regulation of mTORC1 by Amino Acids in Mammalian Cells

    Directory of Open Access Journals (Sweden)

    Yao Yao

    2017-07-01

    Full Text Available The mechanistic target of rapamycin complex 1 (mTORC1 is a master regulator of cell growth in eukaryotic cells. The active mTORC1 promotes cellular anabolic processes including protein, pyrimidine, and lipid biosynthesis, and inhibits catabolic processes such as autophagy. Consistent with its growth-promoting functions, hyper-activation of mTORC1 signaling is one of the important pathomechanisms underlying major human health problems including diabetes, neurodegenerative disorders, and cancer. The mTORC1 receives multiple upstream signals such as an abundance of amino acids and growth factors, thus it regulates a wide range of downstream events relevant to cell growth and proliferation control. The regulation of mTORC1 by amino acids is a fast-evolving field with its detailed mechanisms currently being revealed as the precise picture emerges. In this review, we summarize recent progress with respect to biochemical and biological findings in the regulation of mTORC1 signaling on the lysosomal membrane by amino acids.

  12. Update on lysosomal acid lipase deficiency: Diagnosis, treatment and patient management.

    Science.gov (United States)

    Camarena, Carmen; Aldamiz-Echevarria, Luis J; Polo, Begoña; Barba Romero, Miguel A; García, Inmaculada; Cebolla, Jorge J; Ros, Emilio

    2017-05-10

    Lysosomal acid lipase deficiency (LALD) is an ultra-rare disease caused by a congenital disorder of the lipid metabolism, characterized by the deposition of cholesterol esters and triglycerides in the organism. In patients with no enzyme function, the disease develops during the perinatal period and is invariably associated with death during the first year of life. In all other cases, the phenotype is heterogeneous, although most patients develop chronic liver diseases and may also develop an early cardiovascular disease. Treatment for LALD has classically included the use of supportive measures that do not prevent the progression of the disease. In 2015, regulatory agencies approved the use of a human recombinant LAL for the treatment of LALD. This long-term enzyme replacement therapy has been associated with significant improvements in the hepatic and lipid profiles of patients with LALD, increasing survival rates in infants with a rapidly progressive disease. Both the severity of LALD and the availability of a specific treatment highlight the need to identify these patients in clinical settings, although its low prevalence and the existing clinical overlap with other more frequent pathologies limit its diagnosis. In this paper we set out practical recommendations to identify and monitor patients with LALD, including a diagnostic algorithm, along with an updated treatment. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  13. Cytosolic flagellin-induced lysosomal pathway regulates inflammasome-dependent and -independent macrophage responses.

    Science.gov (United States)

    Lage, Silvia L; Buzzo, Carina L; Amaral, Eduardo P; Matteucci, Kely C; Massis, Liliana M; Icimoto, Marcelo Y; Carmona, Adriana Karaoglanovic; D'Império Lima, Maria R; Rodrigues, Mauricio M; Ferreira, Luis C S; Amarante-Mendes, Gustavo P; Bortoluci, Karina R

    2013-08-27

    NAIP5/NLRC4 (neuronal apoptosis inhibitory protein 5/nucleotide oligomerization domain-like receptor family, caspase activation recruitment domain domain-containing 4) inflammasome activation by cytosolic flagellin results in caspase-1-mediated processing and secretion of IL-1β/IL-18 and pyroptosis, an inflammatory cell death pathway. Here, we found that although NLRC4, ASC, and caspase-1 are required for IL-1β secretion in response to cytosolic flagellin, cell death, nevertheless, occurs in the absence of these molecules. Cytosolic flagellin-induced inflammasome-independent cell death is accompanied by IL-1α secretion and is temporally correlated with the restriction of Salmonella Typhimurium infection. Despite displaying some apoptotic features, this peculiar form of cell death do not require caspase activation but is regulated by a lysosomal pathway, in which cathepsin B and cathepsin D play redundant roles. Moreover, cathepsin B contributes to NAIP5/NLRC4 inflammasome-induced pyroptosis and IL-1α and IL-1β production in response to cytosolic flagellin. Together, our data describe a pathway induced by cytosolic flagellin that induces a peculiar form of cell death and regulates inflammasome-mediated effector mechanisms of macrophages.

  14. Oral Health Status of Patients with Lysosomal Storage Diseases in Poland

    Directory of Open Access Journals (Sweden)

    Damian Drążewski

    2017-03-01

    Full Text Available Patients with lysosomal storage diseases (LSDs suffer from physical and mental disabilities, which together with poor access to professional care may lead to impaired oral health. This cross-sectional case-control study characterized the status of oral health in patients with LSDs in Poland. Thirty-six children and young adults with various forms of LSDs were examined. The data were compared with those from age- and sex-matched healthy controls. Exemplary cases were presented to highlight typical problems in oral care associated with LSDs. When possible, saliva was collected and analyzed for total protein, inflammatory mediators, and antioxidant status. Generally, patients with LSDs had significantly higher prevalence of caries, inferior gingival status, and inadequate oral hygiene. The severity of oral health impairment in mucopolysaccaridoses, the most common LSD in Poland, was similar to that seen in patients with mannosidoses or Pompe disease. Saliva could be collected only from few less handicapped patients. In MPS, it did not appear to differ significantly from the controls, but in patients with Pompe disease it contained lower concentrations of vascular endothelial growth factor (VEGF and monocyte chemoattractant protein-1 (MCP-1, but higher levels of tumor necrosis factor receptors 1 and 2 (TNF-R1, TNF-R2 and myeloperoxidase (MPO. In conclusion, Polish patients with LSDs have an inadequate level of oral hygiene and substantially deteriorated oral health.

  15. The Role of Next-Generation Sequencing in the Diagnosis of Lysosomal Storage Disorders

    Directory of Open Access Journals (Sweden)

    Katalin Komlosi MD, PhD

    2016-10-01

    Full Text Available Next-generation sequencing (NGS panels are used widely in clinical diagnostics to identify genetic causes of various monogenic disease groups including neurometabolic disorders and, more recently, lysosomal storage disorders (LSDs. Many new challenges have been introduced through these new technologies, both at the laboratory level and at the bioinformatics level, with consequences including new requirements for interpretation of results, and for genetic counseling. We review some recent examples of the application of NGS technologies, with purely diagnostic and with both diagnostic and research aims, for establishing a rapid genetic diagnosis in LSDs. Given that NGS can be applied in a way that takes into account the many issues raised by international consensus guidelines, it can have a significant role even early in the course of the diagnostic process, in combination with biochemical and clinical data. Besides decreasing the delay in diagnosis for many patients, a precise molecular diagnosis is extremely important as new therapies are becoming available within the LSD spectrum for patients who share specific types of mutations. A genetic diagnosis is also the prerequisite for genetic counseling, family planning, and the individual choice of reproductive options in affected families.

  16. Oral Health Status of Patients with Lysosomal Storage Diseases in Poland.

    Science.gov (United States)

    Drążewski, Damian; Grzymisławska, Małgorzata; Korybalska, Katarzyna; Czepulis, Natasza; Grzymisławski, Marian; Witowski, Janusz; Surdacka, Anna

    2017-03-09

    Patients with lysosomal storage diseases (LSDs) suffer from physical and mental disabilities, which together with poor access to professional care may lead to impaired oral health. This cross-sectional case-control study characterized the status of oral health in patients with LSDs in Poland. Thirty-six children and young adults with various forms of LSDs were examined. The data were compared with those from age- and sex-matched healthy controls. Exemplary cases were presented to highlight typical problems in oral care associated with LSDs. When possible, saliva was collected and analyzed for total protein, inflammatory mediators, and antioxidant status. Generally, patients with LSDs had significantly higher prevalence of caries, inferior gingival status, and inadequate oral hygiene. The severity of oral health impairment in mucopolysaccaridoses, the most common LSD in Poland, was similar to that seen in patients with mannosidoses or Pompe disease. Saliva could be collected only from few less handicapped patients. In MPS, it did not appear to differ significantly from the controls, but in patients with Pompe disease it contained lower concentrations of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1), but higher levels of tumor necrosis factor receptors 1 and 2 (TNF-R1, TNF-R2) and myeloperoxidase (MPO). In conclusion, Polish patients with LSDs have an inadequate level of oral hygiene and substantially deteriorated oral health.

  17. Marked enhancement of lysosomal targeting and efficacy of ErbB2-targeted drug delivery by HSP90 inhibition.

    Science.gov (United States)

    Raja, Srikumar M; Desale, Swapnil S; Mohapatra, Bhopal; Luan, Haitao; Soni, Kruti; Zhang, Jinjin; Storck, Matthew A; Feng, Dan; Bielecki, Timothy A; Band, Vimla; Cohen, Samuel M; Bronich, Tatiana K; Band, Hamid

    2016-03-01

    Targeted delivery of anticancer drugs to tumor cells using monoclonal antibodies against oncogenic cell surface receptors is an emerging therapeutic strategy. These strategies include drugs directly conjugated to monoclonal antibodies through chemical linkers (Antibody-Drug Conjugates, ADCs) or those encapsulated within nanoparticles that in turn are conjugated to targeting antibodies (Antibody-Nanoparticle Conjugates, ANPs). The recent FDA approval of the ADC Trastuzumab-TDM1 (Kadcyla; Genentech; San Francisco) for the treatment of ErbB2-overexpressing metastatic breast cancer patients has validated the strong potential of these strategies. Even though the activity of ANPs and ADCs is dependent on lysosomal traffic, the roles of the endocytic route traversed by the targeted receptor and of cancer cell-specific alterations in receptor dynamics on the efficiency of drug delivery have not been considered in these new targeted therapies. For example, constitutive association with the molecular chaperone HSP90 is thought to either retard ErbB2 endocytosis or to promote its recycling, traits undesirable for targeted therapy with ANPs and ADCs. HSP90 inhibitors are known to promote ErbB2 ubiquitination, targeting to lysosome and degradation. We therefore hypothesized that ErbB2-targeted drug delivery using Trastuzumab-conjugated nanoparticles could be significantly improved by HSP90 inhibitor-promoted lysosomal traffic of ErbB2. Studies reported here validate this hypothesis and demonstrate, both in vitro and in vivo, that HSP90 inhibition facilitates the intracellular delivery of Trastuzumab-conjugated ANPs carrying a model chemotherapeutic agent, Doxorubicin, specifically into ErbB2-overexpressing breast cancer cells, resulting in improved antitumor activity. These novel findings highlight the need to consider oncogene-specific alterations in receptor traffic in the design of targeted drug delivery strategies. We suggest that combination of agents that enhance receptor

  18. Inhibition of Host Cell Lysosome Spreading by Trypanosoma cruzi Metacyclic Stage-Specific Surface Molecule gp90 Downregulates Parasite Invasion.

    Science.gov (United States)

    Rodrigues, João Paulo Ferreira; Sant'ana, Guilherme Hideki Takahashi; Juliano, Maria Aparecida; Yoshida, Nobuko

    2017-09-01

    Successful infection by Trypanosoma cruzi , the agent of Chagas' disease, is critically dependent on host cell invasion by metacyclic trypomastigote (MT) forms. Two main metacyclic stage-specific surface molecules, gp82 and gp90, play determinant roles in target cell invasion in vitro and in oral T. cruzi infection in mice. The structure and properties of gp82, which is highly conserved among T. cruzi strains, are well known. Information on gp90 is still rather sparse. Here, we attempted to fill that gap. gp90, purified from poorly invasive G strain MT and expressing gp90 at high levels, inhibited HeLa cell lysosome spreading and the gp82-mediated internalization of a highly invasive CL strain MT expressing low levels of a diverse gp90 molecule. A recombinant protein containing the conserved C-terminal domain of gp90 exhibited the same properties as the native G strain gp90: it counteracted the host cell lysosome spreading induced by recombinant gp82 and exhibited an inhibitory effect on HeLa cell invasion by CL strain MT. Assays to identify the gp90 sequence associated with the property of downregulating MT invasion, using synthetic peptides spanning the gp90 C-terminal domain, revealed the sequence GVLYTADKEW. These data, plus the findings that lysosome spreading was induced upon HeLa cell interaction with CL strain MT, but not with G strain MT, and that in mixed infection CL strain MT internalization was inhibited by G strain MT, suggest that the inhibition of target cell lysosome spreading is the mechanism by which the gp90 molecule exerts its downregulatory role. Copyright © 2017 Rodrigues et al.

  19. Fiber type conversion by PGC-1α activates lysosomal and autophagosomal biogenesis in both unaffected and Pompe skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Shoichi Takikita

    2010-12-01

    Full Text Available PGC-1α is a transcriptional co-activator that plays a central role in the regulation of energy metabolism. Our interest in this protein was driven by its ability to promote muscle remodeling. Conversion from fast glycolytic to slow oxidative fibers seemed a promising therapeutic approach in Pompe disease, a severe myopathy caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA which is responsible for the degradation of glycogen. The recently approved enzyme replacement therapy (ERT has only a partial effect in skeletal muscle. In our Pompe mouse model (KO, the poor muscle response is seen in fast but not in slow muscle and is associated with massive accumulation of autophagic debris and ineffective autophagy. In an attempt to turn the therapy-resistant fibers into fibers amenable to therapy, we made transgenic KO mice expressing PGC-1α in muscle (tgKO. The successful switch from fast to slow fibers prevented the formation of autophagic buildup in the converted fibers, but PGC-1α failed to improve the clearance of glycogen by ERT. This outcome is likely explained by an unexpected dramatic increase in muscle glycogen load to levels much closer to those observed in patients, in particular infants, with the disease. We have also found a remarkable rise in the number of lysosomes and autophagosomes in the tgKO compared to the KO. These data point to the role of PGC-1α in muscle glucose metabolism and its possible role as a master regulator for organelle biogenesis - not only for mitochondria but also for lysosomes and autophagosomes. These findings may have implications for therapy of lysosomal diseases and other disorders with altered autophagy.

  20. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease.

    Science.gov (United States)

    Nixon, Ralph A

    2017-07-01

    Abnormalities of the endosomal-lysosomal network (ELN) are a signature feature of Alzheimer's disease (AD). These include the earliest known cytopathology that is specific to AD and that affects endosomes and induces the progressive failure of lysosomes, each of which are directly linked by distinct mechanisms to neurodegeneration. The origins of ELN dysfunction and β-amyloidogenesis closely overlap, which reflects their common genetic basis, the established early involvement of endosomes and lysosomes in amyloid precursor protein (APP) processing and clearance, and the pathologic effect of certain APP metabolites on ELN functions. Genes that promote β-amyloidogenesis in AD (APP, PSEN1/2, and APOE4) have primary effects on ELN function. The importance of primary ELN dysfunction to pathogenesis is underscored by the mutations in more than 35 ELN-related genes that, thus far, are known to cause familial neurodegenerative diseases even though different pathogenic proteins may be involved. In this article, I discuss growing evidence that implicates AD gene-driven ELN disruptions as not only the antecedent pathobiology that underlies β-amyloidogenesis but also as the essential partner with APP and its metabolites that drive the development of AD, including tauopathy, synaptic dysfunction, and neurodegeneration. The striking amelioration of diverse deficits in animal AD models by remediating ELN dysfunction further supports a need to integrate APP and ELN relationships, including the role of amyloid-β, into a broader conceptual framework of how AD arises, progresses, and may be effectively therapeutically targeted.-Nixon, R. A. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease. © FASEB.

  1. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    OpenAIRE

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; DuRoss, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-01-01

    2-Hydroxy-propyl-?-cyclodextrin (HP?CD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HP?CD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (e...

  2. Salivary Tick Cystatin OmC2 Targets Lysosomal Cathepsins S and C in Human Dendritic Cells

    Czech Academy of Sciences Publication Activity Database

    Zavasnik-Bergant, T.; Vidmar, R.; Sekirnik, A.; Fonovic, M.; Salát, Jiří; Grunclová, Lenka; Kopáček, Petr; Turk, B.

    2017-01-01

    Roč. 7, JUN 30 (2017), č. článku 288. ISSN 2235-2988 R&D Projects: GA ČR GA13-11043S Institutional support: RVO:60077344 Keywords : cystatin OmC2 * tick saliva * cathepsin S * cathepsin C * lysosomal proteases * dpp1 * dipeptidyl peptidase 1 * dendritic cells Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 4.300, year: 2016

  3. Effects of the polyene antibiotic derivative MS-8209 on the astrocyte lysosomal system of scrapie-infected hamsters.

    Science.gov (United States)

    Grigoriev, Vladimir B; Adjou, Karim T; Salès, Nicole; Simoneau, Steve; Deslys, Jean-Philippe; Seman, Michel; Dormont, Dominique; Fournier, Jean-Guy

    2002-06-01

    Amphotericine B (AmB), a macrolide polyene antibiotic, is one of a few drugs that has shown therapeutic properties in scrapie-infected hamster. Its beneficial effect on survival time is mostly marked when animals are treated with its derivative MS-8209. To explore the MS-8209 effect at the cellular level, we investigated at the light and electron microscopy levels, the sequential appearance and distribution of PrP concurrently with histopathological changes in hamsters that were infected intracerebrally with the 263 K scrapie strain and treated or not with the drug. The first histopathological modifications and PrP immunostaining were observed in the thalamus and at the inoculation site where the drug caused a delay in the appearance of lesions and PrP accumulation. Using immunoelectron microscopy, at 70 d postinfection, the inoculation site of untreated animals showed an accumulation of PrP in plaque areas constitued by filaments mixed with alterated membrane structures and in developed lysosomal system of reactive astrocytes. Most of the numerous lysosomes containing PrP showed intra-organelle filaments. In contrast, in MS-8209 treated animals, the number of lysosomes was significantly lower (p < 0.0038), with very few organelles harboring PrP. Our results suggest that in this scrapie model, MS-8209 treatment delays the disease by preventing the replication of the scrapie agent at the inoculation site where the astrocytes appear to be the first cells producing abnormal PrP. The lysosomal system of these astrocytes could constitute a privileged target for MS-8209.

  4. Crosstalk Between the Autophagy-Lysosome Pathway and the Ubiquitin-Proteasome Pathway in Retinal Pigment Epithelial Cells.

    Science.gov (United States)

    Zhan, J; He, J; Zhou, Y; Wu, M; Liu, Y; Shang, F; Zhang, X

    2016-01-01

    The accumulation of damaged or misfolded proteins in retinal pigment epithelial (RPE) cells was considered a contributing factor for RPE dysfunction in age-related macular degeneration (AMD). The ubiquitinproteasome pathway (UPP) and the autophagy-lysosome pathway (ALP) are the two major proteolytic systems for clearance of misfolded or damaged proteins. The aim is to investigate how these two systems communicate and coordinate with each other in RPE cells for eliminating intracellular misfolded and damaged proteins. Cultured ARPE-19 cells were treated with proteasome inhibitor MG132 and lysosomotropic agent chloroquine (CQ), respectively. The levels and cellular distributions of ubiquitinated proteins, LC3-I, LC3-II, LAMP1 and p62 were analyzed by Western blotting and immunofluorescence. Proteasome activity was determined using Suc-LLVY-AMC as a substrate. The level of ubiquitinated protein aggregations was significantly increased after the treatment of MG132 in RPE cells. The levels of LC3-I, LC3-II and LAMP1 increased in MG132 treated cells. The levels of γ-tubulin and p62 also increased in MG132 treated cells, suggesting that inhibition of the UPP up-regulates autophagy-lysosome pathway. Inhibition of lysosomal activity with CQ also increased the levels of high mass ubiquitin conjugates, LC3-II and p62. In addition, proteasome activity was compromised upon prolonged lysosomal inhibition. These data indicate that the UPP and the ALP are interrelated and that dysfunction of the ALP would also result in dysfunction of the UPP and severely compromise the capacity of eliminating misfolded and other forms of damaged proteins.

  5. N-Pyridineium-2-yl Darrow Red analogue: unique near-infrared lysosome-biomarker for the detection of cancer cells.

    Science.gov (United States)

    He, Dan-Dan; Liu, Wu; Sun, Ru; Fan, Chen; Xu, Yu-Jie; Ge, Jian-Feng

    2015-02-03

    The lysosome-targetable OFF-ON type pH sensor that does not emit at pH = 4.0 is adopted for the selective detection of cancer cells, and the acidity difference of lysosomes in cancer and normal cells is verified. Three pH probes based on Darrow Red derivatives were designed and prepared that were demonstrated to be lysosome-specific biomarkers with inducible emission at 580-850 nm by the comparable in cellular imaging assays using HeLa, KB, and V79 cells. Of these, a pyridineium-2-yl Darrow Red analogue with a pKa of 2.4 was found to be a lysosome tracker for cancer cells, it is a unique pH sensor for the optical identification and distinction of cancer cells from normal cells and has potential application as a fluorescent biomaker of cancer cells in in vitro assays.

  6. Quantitative co-localization and pattern analysis of endo-lysosomal cargo in subcellular image cytometry and validation on synthetic image sets

    DEFF Research Database (Denmark)

    Lund, Frederik W.; Wüstner, Daniel

    2017-01-01

    -binding protein NPC2 in LE/LYSs relative to cholesterol-rich lysosomal storage organelles (LSOs) stained with filipin. Second, we show how to simulate realistic vesicle patterns in the cell geometry using Markov Chain Monte Carlo and suitable inter-vesicle and cell-vesicle interaction potentials. Finally, we use......Late endosomes and lysosomes (LE/LYSs) play a central role in trafficking of endocytic cargo, secretion of exosomes, and hydrolysis of ingested proteins and lipids. Failure in such processes can lead to lysosomal storage disorders in which a particular metabolite accumulates within LE...... for quantification of the distribution and dynamics of endo-lysosomal cargo from fluorescence images of living cells. First, we explain how to analyze experimental images of endocytic processes in Niemann Pick C2 disease fibroblasts using SpatTrack. We demonstrate how to quantify the location of the sterol...

  7. Label-free silicon nanodots featured ratiometric fluorescent aptasensor for lysosomal imaging and pH measurement.

    Science.gov (United States)

    Zhang, Yanan; Guo, Shan; Cheng, Shibo; Ji, Xinghu; He, Zhike

    2017-08-15

    The homeostasis of lysosomal pH is crucial in cell physiology. Developing small fluorescent nanosensors for lysosome imaging and ratiometric measurement of pH is highly demanded yet challenging. Herein, a pH-sensitive fluorescein tagged aptamer AS1411 has been utilized to covalently modify the label-free fluorescent silicon nanodots via a crosslinker for construction of a ratiometric pH biosensor. The established aptasensor exhibits the advantages of ultrasmall size, hypotoxicity, excellent pH reversibility and good photostability, which favors its application in an intracellular environment. Using human breast MCF-7 cancer cells and MCF-10A normal cells as the model, this aptasensor shows cell specificity for cancer cells and displays a wide pH response range of 4.5-8.0 in living cells. The results demonstrate that the pH of MCF-7 cells is 5.1, which is the expected value for acidic organelles. Lysosome imaging and accurate measurement of pH in MCF-7 cells have been successfully conducted based on this nanosensor via fluorescent microscopy and flow cytometry. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Thiadiazole Carbamates: Potent Inhibitors of Lysosomal Acid Lipase and Potential Niemann-Pick Type C Disease Therapeuticsa

    Science.gov (United States)

    Rosenbaum, Anton I.; Cosner, Casey C.; Mariani, Christopher J.; Maxfield, Frederick R.; Wiest, Olaf; Helquist, Paul

    2010-01-01

    Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized at the cellular level by abnormal accumulation of cholesterol and other lipids in lysosomal storage organelles. Lysosomal acid lipase (LAL) has been recently identified as a potential therapeutic target for NPC. LAL can be specifically inhibited by a variety of 3,4-disubstituted thiadiazole carbamates. An efficient synthesis of the C(3) oxygenated/C(4) aminated analogues has been developed that furnishes the products in high yields and high degrees of purity. Common intermediates can also be used for the synthesis of the C(3) carbon substituted derivatives. Herein we tested various thiadiazole carbamates, amides, esters, and ketones for inhibition of LAL. In addition, we tested a diverse selection of commercially available non-thiadiazole carbamates. Our studies show that, among the compounds examined herein, only thiadiazole carbamates are effective inhibitors of LAL. We present a mechanism for LAL inhibition by these compounds whereby LAL transiently carbamoylates the enzyme similarly to previously described inhibition of acetylcholinesterase by rivastigmine and other carbamates as well as acylation of various lipases by orlistat. PMID:20557099

  9. Thiadiazole carbamates: potent inhibitors of lysosomal acid lipase and potential Niemann-Pick type C disease therapeutics.

    Science.gov (United States)

    Rosenbaum, Anton I; Cosner, Casey C; Mariani, Christopher J; Maxfield, Frederick R; Wiest, Olaf; Helquist, Paul

    2010-07-22

    Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized at the cellular level by abnormal accumulation of cholesterol and other lipids in lysosomal storage organelles. Lysosomal acid lipase (LAL) has been recently identified as a potential therapeutic target for NPC. LAL can be specifically inhibited by a variety of 3,4-disubstituted thiadiazole carbamates. An efficient synthesis of the C(3) oxygenated/C(4) aminated analogues has been developed that furnishes the products in high yields and high degrees of purity. Common intermediates can also be used for the synthesis of the C(3) carbon substituted derivatives. Herein we tested various thiadiazole carbamates, amides, esters, and ketones for inhibition of LAL. In addition, we tested a diverse selection of commercially available non-thiadiazole carbamates. Our studies show that, among the compounds examined herein, only thiadiazole carbamates are effective inhibitors of LAL. We present a mechanism for LAL inhibition by these compounds whereby LAL transiently carbamoylates the enzyme similarly to previously described inhibition of acetylcholinesterase by rivastigmine and other carbamates as well as acylation of various lipases by orlistat.

  10. Two rhodamine lactam modulated lysosome-targetable fluorescence probes for sensitively and selectively monitoring subcellular organelle pH change

    International Nuclear Information System (INIS)

    Li, Hongmei; Wang, Cuiling; She, Mengyao; Zhu, Yuelu; Zhang, Jidong; Yang, Zheng; Liu, Ping; Wang, Yaoyu; Li, Jianli

    2015-01-01

    Be a powerful technique for convenient detection of pH change in living cells, especially at subcellular level, fluorescent probes has attracted more and more attention. In this work, we designed and synthesized three rhodamine lactam modulated fluorescent probes RS1, RS2 and RS3, which all respond sensitively toward weak acidity (pH range 4–6) via the photophysical property in buffer solution without interference from the other metal ions, and they also show ideal pKa values and excellent reversibility. Particularly, by changing the lone pair electrons distribution of lactam-N atom with different conjugations, RS2 and RS3 exhibit high quantum yield, negligible cytotoxicity and excellent permeability. They are suitable to stain selectively lysosomes of tumor cells and monitor its pH changes sensitively via optical molecular imaging. The above findings suggest that the probes we designed could act as ideal and easy method for investigating the pivotal role of H + in lysosomes and are potential pH detectors in disease diagnosis through direct intracellular imaging. - Highlights: • Two probes for sensitively and selectively monitoring weak acidic pH change. • The pKa of the probes was highly suitable for staining lysosomes in tumor cells. • The properties of those probes were changed by different conjugate system. • These probes have negligible cytotoxicity and good sensitivity in vivo.

  11. Cryo-EM structures of the mammalian endo-lysosomal TRPML1 channel elucidate the combined regulation mechanism

    Directory of Open Access Journals (Sweden)

    Sensen Zhang

    2017-09-01

    Full Text Available Abstract TRPML1 channel is a non-selective group-2 transient receptor potential (TRP channel with Ca2+ permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the processes of endocytosis, membrane trafficking, and lysosome biogenesis. Mutations of TRPML1 cause a severe lysosomal storage disorder called mucolipidosis type IV (MLIV. In the present study, we determined the cryo-electron microscopy (cryo-EM structures of Mus musculus TRPML1 (mTRPML1 in lipid nanodiscs and Amphipols. Two distinct states of mTRPML1 in Amphipols are added to the closed state, on which could represent two different confirmations upon activation and regulation. The polycystin-mucolipin domain (PMD may sense the luminal/extracellular stimuli and undergo a “move upward” motion during endocytosis, thus triggering the overall conformational change in TRPML1. Based on the structural comparisons, we propose TRPML1 is regulated by pH, Ca2+, and phosphoinositides in a combined manner so as to accommodate the dynamic endocytosis process.

  12. Andrographolide sensitizes cisplatin-induced apoptosis via suppression of autophagosome-lysosome fusion in human cancer cells.

    Science.gov (United States)

    Zhou, Jing; Hu, Shuai-Er; Tan, Shi-Hao; Cao, Ruoxi; Chen, Yiyang; Xia, Dajing; Zhu, Xinqiang; Yang, Xing-Fen; Ong, Choon-Nam; Shen, Han-Ming

    2012-03-01

    Suppression of autophagy has been increasingly recognized as a novel cancer therapeutic approach. Andrographolide (Andro), a diterpenoid lactone isolated from an herbal plant Andrographis paniculata, is known to possess anti-inflammatory and anticancer activity. In this study, we sought to examine the effect of Andro on autophagy, and to evaluate whether such effect is relevant to the sensitization effect of Andro on apoptosis induced by DNA damage agents in cancer cells. First, we found that Andro is able to significantly enhance autophagic markers in various cancer cell lines, including GFP-LC3 puncta and LC3-II level. Interestingly, Andro treatment also led to marked increase of p62 protein level and addition of chloroquine (CQ) failed to further enhance either LC3-II or p62 level, indicating that Andro is likely to suppress autophagic flux at the maturation and degradation stage. Next, we provided evidence that Andro inhibits autophagosome maturation not by affecting the lysosomal function, but by impairing autophagosome-lysosome fusion. Lastly, we demonstrated that treatment with cisplatin, a DNA damage agent, induces autophagy in cancer cells. Importantly, Andro is capable of sensitizing cisplatin-induced cell killing determined with both short-term apoptosis assays and long-term clonogenic test, via suppression of autophagy, a process independent of p53. In summary, these observations collectively suggest that Andro could be a promising anti-cancer agent in combination therapy via its potent inhibitory effect on autophagy by disrupting autophagosome-lysosome fusion.

  13. Synergistic apoptotic response between valproic acid and fludarabine in chronic lymphocytic leukaemia (CLL) cells involves the lysosomal protease cathepsin B

    International Nuclear Information System (INIS)

    Yoon, J-Y; Szwajcer, D; Ishdorj, G; Benjaminson, P; Xiao, W; Kumar, R; Johnston, J B; Gibson, S B

    2013-01-01

    Fludarabine, a nucleoside analogue, is commonly used in combination with other agents for the treatment of chronic lymphocytic leukaemia (CLL). In previous studies, valproic acid (VPA), an inhibitor of histone deacetylases, combined with fludarabine to synergistically increase apoptotic cell death in CLL cells. In the present study, we found that the combination of fludarabine and VPA decreases the level of the anti-apoptotic proteins Mcl-1 and XIAP in primary CLL cells. Treatment with fludarabine alone, or in combination with VPA, led to the loss of lysosome integrity, and chemical inhibition of the lysosomal protease cathepsin B, using CA074-Me, was sufficient to reduce apoptosis. VPA treatment increased cathepsin B levels and activities in primary CLL cells, thereby priming CLL cells for lysosome-mediated cell death. Six previously treated patients with relapsed CLL were treated with VPA, followed by VPA/fludarabine combination. The combined therapy resulted in reduced lymphocyte count in five out of six and reduced lymph node sizes in four out of six patients. In vivo VPA treatment increased histone-3 acetylation and cathepsin B expression levels. Thus, the synergistic apoptotic response with VPA and fludarabine in CLL is mediated by cathepsin B activation leading to a decrease in the anti-apoptotic proteins

  14. Antioxidants inhibit low density lipoprotein oxidation less at lysosomal pH: A possible explanation as to why the clinical trials of antioxidants might have failed.

    Science.gov (United States)

    Ahmad, Feroz; Leake, David S

    2018-03-05

    Oxidised low density lipoprotein (LDL) was considered to be important in the pathogenesis of atherosclerosis, but the large clinical trials of antioxidants, including the first one using probucol (the PQRST Trial), failed to show benefit and have cast doubt on the importance of oxidised LDL. We have shown previously that LDL oxidation can be catalysed by iron in the lysosomes of macrophages. The aim of this study was therefore to investigate the effectiveness of antioxidants in preventing LDL oxidation at lysosomal pH and also establish the possible mechanism of oxidation. Probucol did not effectively inhibit the oxidation of LDL at lysosomal pH, as measured by conjugated dienes or oxidised cholesteryl esters or tryptophan residues in isolated LDL or by ceroid formation in the lysosomes of macrophage-like cells, in marked contrast to its highly effective inhibition of LDL oxidation at pH 7.4. LDL oxidation at lysosomal pH was inhibited very effectively for long periods by N,N'-diphenyl-1,4-phenylenediamine, which is more hydrophobic than probucol and has been shown by others to inhibit atherosclerosis in rabbits, and by cysteamine, which is a hydrophilic antioxidant that accumulates in lysosomes. Iron-induced LDL oxidation might be due to the formation of the superoxide radical, which protonates at lysosomal pH to form the much more reactive, hydrophobic hydroperoxyl radical, which can enter LDL and reach its core. Probucol resides mainly in the surface monolayer of LDL and would not effectively scavenge hydroperoxyl radicals in the core of LDL. This might explain why probucol failed to protect against atherosclerosis in various clinical trials. The oxidised LDL hypothesis of atherosclerosis now needs to be re-evaluated using different and more effective antioxidants that protect against the lysosomal oxidation of LDL. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes

    Directory of Open Access Journals (Sweden)

    Lee Sook-Jeong

    2010-10-01

    Full Text Available Abstract Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress. Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity. The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the

  16. Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Zahra S Faritous

    2011-01-01

    Full Text Available Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG, 31 women needed prolonged mechanical ventilation (PMV, and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG.

  17. A comparison of low vs conventional-dose heparin for minimal cardiopulmonary bypass in coronary artery bypass grafting surgery.

    Science.gov (United States)

    Fromes, Y; Daghildjian, K; Caumartin, L; Fischer, M; Rouquette, I; Deleuze, P; Bical, O M

    2011-06-01

    The biocompatibility of minimal extracorporeal circuits has improved; however, anticoagulation is still required. We compared standard high-dose anticoagulation with a low-dose heparin regimen in a retrospective study of patients who underwent coronary bypass surgery using minimal cardiopulmonary bypass. One hundred patients who received 300 IU.kg(-1) heparin were compared with 68 patients who received heparin according to an individually adjusted activated coagulation time target of 300 s, resulting in a mean (SD) heparin dose of 145 (30) IU.kg(-1) . There were no thromboembolic events in either group; however, patients in the low-dose group had lower 24-hour mean (SD) postoperative blood loss than the conventional group (545 (61) vs 680 (88) ml, p=0.001) and a reduced rate of transfusion of allogeneic blood (15% patients transfused vs 32%, p=0.01). An individually tailored low-dose heparin regimen for minimal cardiopulmonary bypass is safe and may be associated with reduced bleeding and lower transfusion requirements. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

  18. Implantation of transcatheter aortic valve prosthesis through the ascending aorta concomitant with coronary artery bypass grafting without cardiopulmonary bypass

    Science.gov (United States)

    Leal, João Carlos Ferreira; Avanci, Luis Ernesto; Abelaira Filho, Achilles; Almeida, Thiago Faria; Braile, Domingo Marcolino

    2014-01-01

    Introdution The transcatheter aortic valve implantation in the treatment of high-risk symptomatic aortic stenosis has increased the number of implants every year. The learning curve for transcatheter aortic valve implantation has improved since the last 12 years, allowing access alternatives. Objective The aim of this study is to approach the implantation of transcatheter aortic valve through transaortic via associated with off-pump cardiopulmonary bypass surgery in a 67-year-old man, with chronic obstructive pulmonary disease, arterial hypertension and kidney transplant. Methods Off-pump coronary artery bypass surgery was performed and the valve in the aortic position was released successfully. Results There were no complications in the intraoperative and postoperative period. Gradient reduction, effective orifice increasing of the prosthesis and absence of valvular regurgitation after implantation were observed by transesophageal echocardiography. Conclusion Procedural success demonstrates that implantation of transcatheter aortic valve through the ascending aorta associated with coronary artery bypass surgery without CPB is a new option for these patients. PMID:25714221

  19. Vacuole-mitochondrial cross-talk during apoptosis in yeast: a model for understanding lysosome-mitochondria-mediated apoptosis in mammals.

    Science.gov (United States)

    Sousa, Maria João; Azevedo, Flávio; Azevedo, Flávìa; Pedras, Andreia; Pedras, Ana; Marques, Carolina; Coutinho, Olga P; Preto, Ana; Gerós, Hernâni; Chaves, Susana R; Côrte-Real, Manuela

    2011-10-01

    The yeast apoptosis field emerged with the finding that key components of the apoptotic machinery are conserved in these simple eukaryotes. Thus it became possible to exploit these genetically tractable organisms to improve our understanding of the intricate mechanisms of cell death in higher eukaryotes and of severe human diseases associated with apoptosis dysfunctions. Early on, it was recognized that a mitochondria-mediated apoptotic pathway showing similarities to the mammalian intrinsic pathway was conserved in yeast. Recently, lysosomes have also emerged as central players in mammalian apoptosis. Following LMP (lysosomal membrane permeabilization), lysosomal proteases such as cathepsins B, D and L are released into the cytosol and can trigger a mitochondrial apoptotic cascade. CatD (cathepsin D) can also have anti-apoptotic effects in some cellular types and specific contexts. Nonetheless, the mechanisms underlying LMP and the specific role of cathepsins after their release into the cytosol remain poorly understood. We have recently shown that yeast vacuoles, membrane-bound acidic organelles, which share many similarities to plant vacuoles and mammalian lysosomes, are also involved in the regulation of apoptosis and that the vacuolar protease Pep4p, orthologue of the human CatD, is released from the vacuole into the cytosol in response to acetic acid. Here, we discuss how the conservation of cell-death regulation mechanisms in yeast by the lysosome-like organelle and mitochondria may provide new insights into the understanding of the complex interplay between the mitochondria and lysosome-mediated signalling routes during mammalian apoptosis.

  20. Novel blood sampling method of an artificial endocrine pancreas via the cardiopulmonary bypass circuit.

    Science.gov (United States)

    Kawahito, Shinji; Higuchi, Seiichi; Mita, Naoji; Kitagawa, Tetsuya; Kitahata, Hiroshi

    2013-12-01

    We tried to perform continuous blood glucose monitoring during cardiovascular surgery involving cardiopulmonary bypass using an artificial endocrine pancreas (STG-22 or -55; Nikkiso, Tokyo, Japan); however, we often encountered problems during these procedures because insufficient blood was obtained for monitoring. Thus, we started performing the blood sampling via the venous side of the cardiopulmonary bypass circuit. As a result, continuous blood glucose monitoring using an artificial endocrine pancreas was proven to be stable and reliable during cardiovascular surgery involving cardiopulmonary bypass.

  1. Decoupling internalization, acidification and phagosomal-endosomal/lysosomal fusion during phagocytosis of InlA coated beads in epithelial cells.

    Directory of Open Access Journals (Sweden)

    Craig D Blanchette

    Full Text Available BACKGROUND: Phagocytosis has been extensively examined in 'professional' phagocytic cells using pH sensitive dyes. However, in many of the previous studies, a separation between the end of internalization, beginning of acidification and completion of phagosomal-endosomal/lysosomal fusion was not clearly established. In addition, very little work has been done to systematically examine phagosomal maturation in 'non-professional' phagocytic cells. Therefore, in this study, we developed a simple method to measure and decouple particle internalization, phagosomal acidification and phagosomal-endosomal/lysosomal fusion in Madin-Darby Canine Kidney (MDCK and Caco-2 epithelial cells. METHODOLOGY/PRINCIPAL FINDINGS: Our method was developed using a pathogen mimetic system consisting of polystyrene beads coated with Internalin A (InlA, a membrane surface protein from Listeria monocytogenes known to trigger receptor-mediated phagocytosis. We were able to independently measure the rates of internalization, phagosomal acidification and phagosomal-endosomal/lysosomal fusion in epithelial cells by combining the InlA-coated beads (InlA-beads with antibody quenching, a pH sensitive dye and an endosomal/lysosomal dye. By performing these independent measurements under identical experimental conditions, we were able to decouple the three processes and establish time scales for each. In a separate set of experiments, we exploited the phagosomal acidification process to demonstrate an additional, real-time method for tracking bead binding, internalization and phagosomal acidification. CONCLUSIONS/SIGNIFICANCE: Using this method, we found that the time scales for internalization, phagosomal acidification and phagosomal-endosomal/lysosomal fusion ranged from 23-32 min, 3-4 min and 74-120 min, respectively, for MDCK and Caco-2 epithelial cells. Both the static and real-time methods developed here are expected to be readily and broadly applicable, as they simply

  2. A Case Report of Coronary-Subclavian Steal Syndrome Treated with Carotid to Axillary Artery Bypass

    Directory of Open Access Journals (Sweden)

    Wissam Al-Jundi

    2009-01-01

    Full Text Available Coronary-subclavian steal syndrome results from atherosclerotic disease of the proximal subclavian artery causing reversal of flow in an internal mammary artery used as conduit for coronary artery bypass. This rare complication of cardiac revascularisation leads to recurrence of myocardial ischaemia. When feasible, subclavian angioplasty and/or stent placement can provide acceptable result for these patients. Vascular reconstruction through carotid to subclavian artery bypass has been the standard procedure of choice. Other interventions in literature include axilloaxillary bypass and subclavian carotid transposition. This case report describes the use of carotid axillary artery bypass for the treatment of coronary-subclavian steal syndrome.

  3. Rural Bypass of Critical Access Hospitals in Iowa: Do Visiting Surgical Specialists Make a Difference?

    Science.gov (United States)

    Weigel, Paula A M; Ullrich, Fred; Ward, Marcia M

    2018-02-01

    Rural bypass for elective surgical procedures is a challenge for critical access hospitals, yet there are opportunities for rural hospitals to improve local retention of surgical candidates through alternative approaches to developing surgery lines of business. In this study we examine the effect of visiting surgical specialists on the odds of rural bypass. Discharge data from the 2011 State Inpatient Databases and State Ambulatory Surgery Databases for Iowa were linked to outreach data from the Office of Statewide Clinical Education Programs and Iowa Physician Information System to model the effect of surgeon specialist supply on rural patients' decision to bypass rural critical access hospitals. Patients in rural communities with a local general surgeon were more likely to be retained in a community than to bypass. Those in communities with visiting general surgeons were more likely to bypass, as were those in communities with visiting urologists and obstetricians. Patients in communities with visiting ophthalmologists and orthopedic surgeons were at higher odds of being retained for their elective surgeries. In addition to known patient and local hospital factors that have an influence on bypass behavior among rural patients seeking elective surgery, availability of surgeon specialists also plays an important role in whether patients bypass or not. Visiting ophthalmologists and orthopedic surgeons were associated with less bypass, as was having local general surgeons. Visiting general surgeons, urologists, and obstetricians were associated with greater odds of bypass. © 2016 National Rural Health Association.

  4. Tidlige erfaringer med duplexovervågning af femoropopliteale og -krurale vene-bypass

    DEFF Research Database (Denmark)

    Nielsen, Tina G; von Jessen, Frants; Schroeder, T V

    1993-01-01

    Identification and correction of graft stenoses in femoropopliteal and -crural vein bypasses can prevent reconstruction failure. Sixty six consecutive vein bypasses entered a postoperative surveillance protocol, which implied clinical assessment, measurement of ankle blood pressure and duplex...... could not be reestablished. Of the 34 bypasses with normal duplex-scans only 2 (6%) thrombosed (p blood pressure measurement could reliably predict graft failure. This study indicates that duplex......-scanning effectively identifies grafts at risk and can be expected to improve long-term patency of infrainguinal vein bypasses....

  5. Severe reduction of blood lysosomal acid lipase activity in cryptogenic cirrhosis: A nationwide multicentre cohort study.

    Science.gov (United States)

    Angelico, Francesco; Corradini, Stefano Ginanni; Pastori, Daniele; Fargion, Silvia; Fracanzani, Anna Ludovica; Angelico, Mario; Bolondi, Luigi; Tozzi, Giulia; Pujatti, Pietro Luigi; Labbadia, Giancarlo; Corazza, Gino Roberto; Averna, Maurizio; Perticone, Francesco; Croce, Giuseppe; Persico, Marcello; Bucci, Tommaso; Baratta, Francesco; Polimeni, Licia; Del Ben, Maria; Violi, Francesco

    2017-07-01

    Blood lysosomal acid lipase (LAL) is reduced in non-alcoholic steatohepatitis, which is the major cause of cryptogenic cirrhosis (CC); few data on LAL activity in CC do exist. We investigated LAL activity in a cohort of patients with liver cirrhosis. This is a multicentre cohort study including 274 patients with liver cirrhosis of different aetiology from 19 centres of Internal Medicine, Gastroenterology and Hepatology distributed throughout Italy. Blood LAL activity (nmol/spot/h) was measured with dried blood spot extracts using Lalistat 2. Overall, 133 patients had CC, and 141 patients had cirrhosis by other causes (61 viral, 53 alcoholic, 20 alcoholic + viral, 7 autoimmune). Mean age was 64.2 ± 13.4 years, and 28.5% were women. Patients with CC were older compared to other aetiology-cirrhosis, with a lower Child-Turcotte-Pugh (CTP, p=0.003) and MELD (p=0.009) score, and a higher prevalence of cardio-metabolic risk factors and previous ischemic events. In the whole cohort, median LAL activity value was 0.58 nmol/spot/h, 0.49 and 0.65 in the groups of CC and known-aetiology cirrhosis, respectively (p=0.002). The difference remained significant after adjustment for white blood cells count (p=0.001). Multivariable linear regression analysis showed that CC (vs. known aetiology, Beta = -0.144, p=0.018), platelet count (Beta = 0.398, p < 0.001) and CTP score (Beta = -0.133, p=0.022) were associated with log-LAL activity. Similar results were found using MELD as covariate. We found a marked reduction of LAL activity in patients with cryptogenic cirrhosis compared to the other known aetiologies. A prospective study will clarify the role of LAL in chronic liver diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Activation mobilizes the cholesterol in the late endosomes-lysosomes of Niemann Pick type C cells.

    Directory of Open Access Journals (Sweden)

    Yvonne Lange

    Full Text Available A variety of intercalating amphipaths increase the chemical activity of plasma membrane cholesterol. To test whether intracellular cholesterol can be similarly activated, we examined NPC1 and NPC2 fibroblasts, since they accumulate large amounts of cholesterol in their late endosomes and lysosomes (LE/L. We gauged the mobility of intracellular sterol from its appearance at the surface of the intact cells, as determined by its susceptibility to cholesterol oxidase and its isotope exchange with extracellular 2-(hydroxypropyl-β-cyclodextrin-cholesterol. The entire cytoplasmic cholesterol pool in these cells was mobile, exchanging with the plasma membrane with an apparent half-time of ∼3-4 hours, ∼4-5 times slower than that for wild type human fibroblasts (half-time ∼0.75 hours. The mobility of the intracellular cholesterol was increased by the membrane-intercalating amphipaths chlorpromazine and 1-octanol. Chlorpromazine also promoted the net transfer of LE/L cholesterol to serum and cyclodextrin. Surprisingly, the mobility of LE/L cholesterol was greatly stimulated by treating intact NPC cells with glutaraldehyde or formaldehyde. Similar effects were seen with wild type fibroblasts in which the LE/L cholesterol pool had been expanded using U18666A. We also showed that the cholesterol in the intracellular membranes of fixed wild-type fibroblasts was mobile; it was rapidly oxidized by cholesterol oxidase and was rapidly replenished by exogenous sterol. We conclude that a the cholesterol in NPC cells can exit the LE/L (and the extensive membranous inclusions therein over a few hours; b this mobility is stimulated by the activation of the cholesterol with intercalating amphipaths; c intracellular cholesterol is even more mobile in fixed cells; and d amphipaths that activate cholesterol might be useful in treating NPC disease.

  7. Comparative proteomic analysis of lung lamellar bodies and lysosome-related organelles.

    Directory of Open Access Journals (Sweden)

    Ross Ridsdale

    2011-01-01

    Full Text Available Pulmonary surfactant is a complex mixture of lipids and proteins that is essential for postnatal function. Surfactant is synthesized in alveolar type II cells and stored as multi-bilayer membranes in a specialized secretory lysosome-related organelle (LRO, known as the lamellar body (LB, prior to secretion into the alveolar airspaces. Few LB proteins have been identified and the mechanisms regulating formation and trafficking of this organelle are poorly understood. Lamellar bodies were isolated from rat lungs, separated into limiting membrane and core populations, fractionated by SDS-PAGE and proteins identified by nanoLC-tandem mass spectrometry. In total 562 proteins were identified, significantly extending a previous study that identified 44 proteins in rat lung LB. The lung LB proteome reflects the dynamic interaction of this organelle with the biosynthetic, secretory and endocytic pathways of the type II epithelial cell. Comparison with other LRO proteomes indicated that 60% of LB proteins were detected in one or more of 8 other proteomes, confirming classification of the LB as a LRO. Remarkably the LB shared 37.8% of its proteins with the melanosome but only 9.9% with lamellar bodies from the skin. Of the 229 proteins not detected in other LRO proteomes, a subset of 34 proteins was enriched in lung relative to other tissues. Proteins with lipid-related functions comprised a significant proportion of the LB unique subset, consistent with the major function of this organelle in the organization, storage and secretion of surfactant lipid. The lung LB proteome will facilitate identification of molecular pathways involved in LB biogenesis, surfactant homeostasis and disease pathogenesis.

  8. Distal anastomotic vein adjunct usage in infrainguinal prosthetic bypasses.

    Science.gov (United States)

    McPhee, James T; Goodney, Philip P; Schanzer, Andres; Shaykevich, Shimon; Belkin, Michael; Menard, Matthew T

    2013-04-01

    Single-segment saphenous vein remains the optimal conduit for infrainguinal revascularization. In its absence, prosthetic conduit may be used. Existing data regarding the significance of anastomotic distal vein adjunct (DVA) usage with prosthetic grafts are based on small series. This is a retrospective cohort analysis derived from the regional Vascular Study Group of New England as well as the Brigham and Women's hospital database. A total of 1018 infrainguinal prosthetic bypass grafts were captured in the dataset from 73 surgeons at 15 participating institutions. Propensity scoring and 3:1 matching was performed to create similar exposure groups for analysis. Outcome measures of interest included: primary patency, freedom from major adverse limb events (MALEs), and amputation free survival at 1 year as a function of vein patch utilization. Time to event data were compared with the log-rank test; multivariable Cox proportional hazard models were used to evaluate the adjusted association between vein cuff usage and the primary end points. DVA was defined as a vein patch, cuff, or boot in any configuration. Of the 1018 bypass operations, 94 (9.2%) had a DVA whereas 924 (90.8%) did not (no DVA). After propensity score matching, 88 DVAs (25%) and 264 no DVAs (75%) were analyzed. On univariate analysis of the matched cohort, the DVA and no DVA groups were similar in terms of mean age (70.0 vs 69.0; P = .55), male sex (58.0% vs 58.3%; P > .99), and preoperative characteristics such as living at home (93.2% vs 94.3%; P = .79) and independent ambulatory status (72.7% vs 75.7%; P = .64). The DVA and no DVA groups had similar rates of major comorbidities such as hypertension chronic obstructive pulmonary disease, diabetes mellitus, coronary artery disease, and dialysis dependence (P > .05 for all). Likewise, they had similar rates of distal origin grafts (13.6% vs 12.5%; P = .85), critical limb ischemia indications (P = .53), and prior arterial bypass (58% vs 47%; P = .08

  9. [Outcome of gastric bypass surgery in Iceland 2001-2015].

    Science.gov (United States)

    Thorarinsdottir, Rosamunda; Palmason, Vilhjalmur; Leifsson, Bjorn Geir; Gislason, Hjortur

    2016-01-01

    Laparoscopic roux-en-y gastric bypass (LRYGB) has been performed at Landspitali University Hospital (LSH) since 2001. The procedure represents an important treatment option for morbidly obese patients. The aim of this study is to evaluate the long-term results of these operations in Iceland. All 772 consecutive patients undergoing LRYGB at LSH during 2001-2015 were included. Information was collected from a prospective database. Successful weight loss was defined as body mass index (BMI) less than 33 kg/m2 or excess body mass index loss (EBMIL) more than 50%. Mean age of patients was 41 years and 83% were females. Mean pre-operative weight was 127 kg (±20) and mean BMI was 44 (±6). Mean %EBMIL was 80% after 1.5 year, 70% after 5 years and 64% after 10-13 years. 85% of patients had successful weight loss with a mean follow-up time of 7.4 years. Pre-operatively patients on average had 2.8 obesity related comorbid diseases. 71% of patients with type 2 diabetes were in full remission after surgery. One third of patients with hypertension and one third of patients with hyperlipidemia achieved full remission after surgery. 37 patients (5%) had an early complication and 174 (25%) had a late complication that frequently needed surgical solution. Most patients (78%) needed repeated adjustment of vitamins and minerals often many years after surgery. Majority of patients achieved a successful weight loss and most obesity related comorbidities are still in remission 7.4 years after surgery. Early complications were rare but one fourth of patients had late complications. Life long follow-up is of utmost importance after gastric bypass surgery. Key words: gastric bypass surgery in Iceland 2001-2015. Correspondence: Hjörtur Gíslason, hjorturg@landspitali.is.

  10. Off-pump coronary artery bypass prevents visceral organ damage.

    Science.gov (United States)

    Bierbach, Benjamin; Bomberg, Hagen; Pritzer, Hartmut; Prabhu, Sudesh; Petzina, Rainer; Kempski, Oliver; Horstick, Georg; Cremer, Jochen; Hoffmann, Grischa

    2014-06-01

    Visceral malperfusion after coronary artery bypass grafting (CABG) results in high morbidity and mortality. This study was designed to evaluate the effect of CABG performed by surgical techniques on visceral perfusion and function. Pigs (n = 28) were studied in four groups: I. Sham; II. Off-pump coronary artery bypass grafting (OPCAB): 1 h stabilizer with 40 min intracoronary shunt; III. Extracorporeal circulation (ECC): 1 h ECC with 40 min aortic cross-clamping and cardioplegic arrest; IV. Impella: 1 h left ventricular blood-pump support and stabilizer with 40 min intracoronary shunt. A left internal mammary to left anterior descending coronary artery bypass was performed in Groups II-IV. All animals were observed for a further 240 min. During the experiment haemodynamics, creatinine clearance, intestinal fatty acid binding protein (iFABP), pancreatic (lipase and amylase) and liver enzymes (α-glutathione s-transferase, glutamate-oxaloacetate transaminase (GOT), gamma-glutamyl transferase (GGT), glutamate dehydrogenase and glutamate-pyruvate transaminase (GPT)) were measured. Visceral perfusion (VP) was assessed in both kidneys, intestine, pancreas, liver and spleen with 15 µm fluorescent microspheres. During OPCAB surgery, VP decreased slightly. Renal functional parameters, iFABP, pancreatic and liver enzymes remained unchanged. ECC and Impella led to significantly reduced renal, pancreatic and intestinal blood flow (P < 0.05). Creatinine clearance, pancreatic and liver (GPT, GGT) enzymes were significantly decreased only after ECC (P < 0.05). ECC and Impella resulted in a significantly increased iFABP level (P < 0.05). GOT was elevated significantly after surgery in Groups II, III and IV (P < 0.05). CABG with ECC or Impella leads to impaired visceral blood flow and function. OPCAB minimizes these procedure associated alterations. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All

  11. Cine CT in the evaluation of coronary bypass graft patency

    International Nuclear Information System (INIS)

    Stanford, W.; Rooholamini, M.; Rumberger, J.; Marcus, M.; Hiratzka, L.

    1986-01-01

    Cine CT produces axial images over an 8-cm section of the aorta in 50 msec. This characteristic makes the technique useful for evaluating coronary bypass graft (CBG) patency. With the use of 40 ml of 67% iothalamate sodium injected via an antecubital vein, 28 patients with 68 CBGs underwent cine CT. Ten patients with 21 CBGs also underwent cardiac catheterization. In the latter group the overall accuracy of cine CT compared to cardiac catheterization was 95.2% (20/21). The sensitivity was 94.1% (16/17), and the specificity was 100% (4/4). This figure compares favorably with the 92% sensitivity achieved with conventional CT

  12. Reconstructive surgery after jejunoileal bypass or gastric partition operations.

    Science.gov (United States)

    Bingham, H G

    1982-05-01

    Twenty-five morbidly obese patients had plastic operations to remove redundant tissue after either jejunoileal bypass or gastric partition. The average weight loss in this group of patients was 79.9 kg (176 lb) and the average age was 32 years. Abdominoplasty was the most common operation, and, although there was no mortality, postoperative complications were common and usually related to wound healing. The average hospital stay was ten days. Most of these patients were pleased with their results and lived happier and more productive lives.

  13. Vacuum-assisted drainage in cardiopulmonary bypass: advantages and disadvantages.

    Science.gov (United States)

    Carvalho Filho, Elio Barreto de; Marson, Fernando Augusto de Lima; Costa, Loredana Nilkenes Gomes da; Antunes, Nilson

    2014-01-01

    Systematic review of vacuum assisted drainage in cardiopulmonary bypass, demonstrating its advantages and disadvantages, by case reports and evidence about its effects on microcirculation. We conducted a systematic search on the period 1997-2012, in the databases PubMed, Medline, Lilacs and SciELO. Of the 70 selected articles, 26 were included in the review. Although the vacuum assisted drainage has significant potential for complications and requires appropriate technology and professionalism, prevailed in literature reviewed the concept that vacuum assisted drainage contributed in reducing the rate of transfusions, hemodilutions, better operative field, no significant increase in hemolysis, reduced complications surgical, use of lower prime and of smaller diameter cannulas.

  14. Effect of morbid obesity, gastric banding and gastric bypass on esophageal symptoms, mucosa and function.

    Science.gov (United States)

    Borovicka, Jan; Krieger-Grübel, Claudia; van der Weg, Boudewijn; Thurnheer, Martin; Schultes, Bernd; Sulz, Michael Christian; Gutzwiler, Jean-Pierre; Bisang, Philipp; Pohl, Daniel; Fried, Michael; Meyenberger, Christa; Tutuian, Radu

    2017-02-01

    Obesity and gastroesophageal reflux disease (GERD) are commonly associated diseases. Bariatric surgery has been shown to have various impacts on esophageal function and GERD. Our aim was to evaluate changes in symptoms, endoscopic findings, bolus passage and esophageal function in patients after primary gastric bypass surgery as compared to patients converted from gastric banding to gastric bypass. Obese patients scheduled for laparoscopic Roux-en-Y gastric bypass (naïve-to-bypass) and patients who previously underwent gastric banding and were considered for conversion from gastric banding to gastric bypass (band-to-bypass) were included. Patients rated esophageal and epigastric symptoms (100 point VAS) and underwent upper endoscopy, impedance-manometry, and modified "timed barium swallow" before/after surgery. Data from 66 naïve-to-bypass patients (51/66, 77 % females, mean age 41.2 ± 11.1 years) and 68 band-to-bypass patients (53/68, 78 % females, mean age 43.8 ± 10.0 years) were available for analysis. Esophageal symptoms, esophagitis, esophageal motility abnormalities and impaired esophageal bolus transit were more common in patients that underwent gastric banding compared to those that underwent gastric bypass. The majority of symptoms, lesions and abnormalities induced by gastric banding were decreased by conversion to gastric bypass. Esophagitis was present in 28/68 (41 %) and 13/47 (28 %) patients in the band-to-bypass group, pre- versus postoperatively, respectively, (p symptoms and should be therefore favored over gastric banding in difficult to treat obese patients at risk of repeated bariatric surgery.

  15. Fuel temperature prediction using a variable bypass gap size in the prismatic VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Nam, E-mail: snlee@kaeri.re.kr; Tak, Nam-il; Kim, Min Hwan

    2016-04-15

    Highlights: • The bypass flow of the prismatic very high temperature reactor is analyzed. • The bypass gap sizes are calculated considering the effect of the neutron fluences and thermal expansion. • The fuel hot spot temperature and temperature profiles are calculated using the variable gap size. • The BOC, MOC and EOC condition at the cycle 07 and 14 are applied. - Abstract: The temperature gradient and hot spot temperatures were calculated in the prismatic very high temperature reactor as a function of the variable bypass gap size. Many previous studies have predicted the temperature of the reactor core based on a fixed bypass gap size. The graphite matrix of the assemblies in the reactor core undergoes a dimensional change during the operation due to thermal expansion and neutron fluence. The expansion and shrinkage of the bypass gaps change the coolant flow fractions into the coolant channels, the control rod holes, and the bypass gaps. Therefore, the temperature of the assemblies may differ compared to those for the fixed bypass gap case. The temperature gradient and the hot spot temperatures are important for the design of reactor structures to ensure their safety and efficiency. In the present study, the temperature variation of the PMR200 is studied at the beginning (BOC), middle (MOC), and end (EOC) of cycles 07 and 14. CORONA code which has been developed in KAERI is applied to solve the thermal-hydraulics of the reactor core of the PMR200. CORONA solves a fluid region using a one-dimensional formulation and a solid region using a three-dimensional formulation to enhance the computational speed and still obtain a reasonable accuracy. The maximum temperatures in the fuel assemblies using the variable bypass gaps did not differ much from the corresponding temperatures using the fixed bypass gaps. However, the maximum temperatures in the reflector assemblies using the variable bypass gaps differ significantly from the corresponding temperatures

  16. Fuel temperature prediction using a variable bypass gap size in the prismatic VHTR

    International Nuclear Information System (INIS)

    Lee, Sung Nam; Tak, Nam-il; Kim, Min Hwan

    2016-01-01

    Highlights: • The bypass flow of the prismatic very high temperature reactor is analyzed. • The bypass gap sizes are calculated considering the effect of the neutron fluences and thermal expansion. • The fuel hot spot temperature and temperature profiles are calculated using the variable gap size. • The BOC, MOC and EOC condition at the cycle 07 and 14 are applied. - Abstract: The temperature gradient and hot spot temperatures were calculated in the prismatic very high temperature reactor as a function of the variable bypass gap size. Many previous studies have predicted the temperature of the reactor core based on a fixed bypass gap size. The graphite matrix of the assemblies in the reactor core undergoes a dimensional change during the operation due to thermal expansion and neutron fluence. The expansion and shrinkage of the bypass gaps change the coolant flow fractions into the coolant channels, the control rod holes, and the bypass gaps. Therefore, the temperature of the assemblies may differ compared to those for the fixed bypass gap case. The temperature gradient and the hot spot temperatures are important for the design of reactor structures to ensure their safety and efficiency. In the present study, the temperature variation of the PMR200 is studied at the beginning (BOC), middle (MOC), and end (EOC) of cycles 07 and 14. CORONA code which has been developed in KAERI is applied to solve the thermal-hydraulics of the reactor core of the PMR200. CORONA solves a fluid region using a one-dimensional formulation and a solid region using a three-dimensional formulation to enhance the computational speed and still obtain a reasonable accuracy. The maximum temperatures in the fuel assemblies using the variable bypass gaps did not differ much from the corresponding temperatures using the fixed bypass gaps. However, the maximum temperatures in the reflector assemblies using the variable bypass gaps differ significantly from the corresponding temperatures

  17. Modified intermittent subfascial wound infiltration with local anaesthetic after open gastric bypass (wound infiltration aftrer gastric bypass

    Directory of Open Access Journals (Sweden)

    Kostić Tamara

    2017-01-01

    Full Text Available Introduction: Infiltration of the surgical wound with local anesthetic through a multi-holed catheter is widely applied as a component of multimodal postoperative analgesia, but there is little evidence of its use in bariatric surgery. A case of modified intermittent subfascial wound infiltration in a morbidly obese patient after open gastric bypass surgery is reported. Case report: A 57-year-old female morbidly obese patient underwent an open gastric bypass. Given the severity of obstructive sleep apnea syndrome and chronic obstructive pulmonary disease as well as limited availability of noninvasive ventilation, the anesthetic plan had to be tailored to minimize opioid consumption in postoperative period. Two multi-holed epidural catheters were placed between peritoneum and muscular fascia along the length of the wound. At the end of the surgery, subfascial and subcutaneous wound infiltration with 20 ml of 0.5% bupivacaine with 5 µg/ml adrenaline was performed. For 72h after surgery 5 ml of 0.25% Bupivacaine with 2 µg/ml Adrenaline were delivered q.i.d. through each catheter. Analgesia was supplemented with intravenous paracetamol 1 g q.i.d, and metamizole 2.5 g b.i.d. Tramadol was administered once for breakthrough pain after admission to intensive care unit. Pain intensity during 72h after surgery was 1-2 at rest and 3 during mobilization on numerical pain scale (NPS 1-10. Postoperative recovery was uneventful. Conclusion: Modified intermittent subfascial wound infiltration with local anesthetic applied through two epidural catheters as a part of multimodal analgesia with minimal usage of opioids provided effective pain relief for morbidly obese patient after open gastric bypass.

  18. Myocardial metabolism during anaesthesia with propofol--low dose fentanyl for coronary artery bypass surgery

    NARCIS (Netherlands)

    Vermeyen, K. M.; de Hert, S. G.; Erpels, F. A.; Adriaensen, H. F.

    1991-01-01

    We have studied the haemodynamic and myocardial effects of propofol-fentanyl anaesthesia in 12 patients undergoing coronary artery bypass surgery during the pre-bypass period. The induction dose of propofol was 1.5 mg kg-1 and mean infusion rate during maintenance was 4.48 mg kg-1 h-1 (range

  19. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H.R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Jacobus Adrianus Maria; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    Background To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Methods Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inlay

  20. Off-pump Coronary Artery Bypass Graft in a High Risk Patient ...

    African Journals Online (AJOL)

    On-pump coronary artery bypass graft (CABG) entails the use of cardiopulmonary bypass (CPB). The procedure is safe but it's not without complications like neurocognitive deficits, cerebrovascular accidents, myocardial ischemic injury and activation of inflammatory pathways that contribute to pulmonary, renal, hematologic ...