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Riedl MA, Maurer M, Bernstein JA, Banerji A, Longhurst HJ, Li HH, Lu P, Hao J, Juethner S, Lumry WR, Hébert J, Ritchie B, Sussman G, Yang WH, Escuriola Ettingshausen C, Magerl M, Martinez‐Saguer I, Maurer M, Staubach P, Zimmer S, Cicardi M, Perego F, Wu MA, Zanichelli A, Al‐Ghazawi A, Shennak M, Zaragoza‐Urdaz RH, Ghurye R, Longhurst HJ, Zinser E, Anderson J, Banerji A, Baptist AP, Bernstein JA, Boggs PB, Busse PJ, Christiansen S, Craig T, Davis‐Lorton M, Gierer S, Gower RG, Harris D, Hong DI, Jacobs J, Johnston DT, Levitch ES, Li HH, Lockey RF, Lugar P, Lumry WR, Manning ME, McNeil DL, Melamed I, Mostofi T, Nickel T, Otto WR, Petrov AA, Poarch K, Radojicic C, Rehman SM, Riedl MA, Schwartz LB, Shapiro R, Sher E, Smith AM, Smith TD, Soteres D, Tachdjian R, Wedner HJ, Weinstein ME, Zafra H, Zuraw BL. Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks. Allergy 2020; 75:2879-2887. [PMID: 32452549 PMCID: PMC7689768 DOI: 10.1111/all.14416] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 02/06/2023]
Abstract
Background Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study. Objective To assess time to onset of effect and long‐term efficacy of lanadelumab, based on exploratory findings from the HELP Study. Methods Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0‐69 findings using a Poisson regression model accounting for overdispersion. Least‐squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0‐69 versus steady state (days 70‐182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints. Results One hundred twenty‐five patients were randomized and treated. During days 0‐69, mean monthly attack rate was significantly lower with lanadelumab (0.41‐0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33‐0.61 vs 1.66) and moderate/severe attacks (0.31‐0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%‐48.1% vs 7.3%) and responders (85.7%‐100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0‐69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable—HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0‐69 and 70‐182. Conclusion Protection with lanadelumab started from the first dose and continued throughout the entire study period.
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Affiliation(s)
- Marc A. Riedl
- Division of Rheumatology, Allergy and Immunology University of California, San Diego San Diego CA USA
| | - Marcus Maurer
- Dermatological Allergology Allergie‐Centrum‐Charité Department of Dermatology and Allergy Charité – Universitätsmedizin Berlin Berlin Germany
| | - Jonathan A. Bernstein
- Division of Immunology/Allergy Section Department of Internal Medicine University of Cincinnati Cincinnati OH USA
- Bernstein Clinical Research Center Cincinnati OH USA
| | - Aleena Banerji
- Division of Rheumatology, Allergy and Immunology Department of Medicine Massachusetts General Hospital Harvard Medical School Boston MA USA
| | - Hilary J. Longhurst
- Addenbrooke's Hospital Cambridge University Hospitals NHS Foundation Trust, Cambridge and University College London Hospitals London UK
| | - H. Henry Li
- Institute for Asthma and Allergy, P.C. Chevy Chase MD USA
| | - Peng Lu
- Shire, a Takeda company Lexington MA USA
| | - James Hao
- Shire, a Takeda company Lexington MA USA
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Kuehn C, Kerek F, Steinkasserer A, Zinser E, Achenbach S, Dietel B. Impact of therapeutic treatment with MCS-18 on advanced murine atherosclerosis. Atherosclerosis 2015. [DOI: 10.1016/j.atherosclerosis.2015.04.150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Eckhardt J, Döbbeler M, König C, Kuczera K, Kuhnt C, Ostalecki C, Zinser E, Mak TW, Steinkasserer A, Lechmann M. Thymic stromal lymphopoietin deficiency attenuates experimental autoimmune encephalomyelitis. Clin Exp Immunol 2015; 181:51-64. [PMID: 25753260 DOI: 10.1111/cei.12621] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 12/19/2022] Open
Abstract
In the present study we examined the role of thymic stromal lymphopoietin (TSLP) in experimental autoimmune encephalomyelitis (EAE). Here, we report that TSLP knock-out (KO) mice display a delayed onset of disease and an attenuated form of EAE. This delayed onset was accompanied by a reduced number of encephalitogenic T helper type 1 (Th1) cells in the central nervous system (CNS) of TSLP KO mice. In addition, CD4(+) and CD8(+) T cells from CNS of TSLP KO mice show a reduced activation status in comparison to wild-type mice. It is noteworthy that we could also show that lymph node cells from TSLP KO mice expanded less efficiently and that interleukin (IL)-6-, interferon (IFN)-γ and tumour necrosis factor (TNF)-α levels were reduced. Furthermore, CD3(+) T cells isolated in the preclinical phase from myelin oligodendrocyte glycoprotein peptide 35-55 (MOG(35-55))-immunized TSLP KO mice showed a reduced response after secondary exposure to MOG(35-55), indicating that differentiation of naive T cells into MOG(35-55)-specific effector and memory T cells was impaired in KO mice. The addition of recombinant TSLP enhanced T cell proliferation during MOG(35-55) restimulation, showing that T cells also respond directly to TSLP. In summary, these data demonstrate that expression of, and immune activation by, TSLP contributes significantly to the immunopathology of EAE.
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Affiliation(s)
- J Eckhardt
- Department of Immune Modulation at the Department of Dermatology
| | - M Döbbeler
- Department of Immune Modulation at the Department of Dermatology
| | - C König
- Department of Immune Modulation at the Department of Dermatology
| | - K Kuczera
- Department of Immune Modulation at the Department of Dermatology
| | - C Kuhnt
- Department of Immune Modulation at the Department of Dermatology
| | - C Ostalecki
- Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - E Zinser
- Department of Immune Modulation at the Department of Dermatology
| | - T W Mak
- The Campbell Family Institute for Breast Cancer Research at Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
| | - A Steinkasserer
- Department of Immune Modulation at the Department of Dermatology
| | - M Lechmann
- Department of Immune Modulation at the Department of Dermatology
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Eckhardt J, Kreiser S, Döbbeler M, Nicolette C, DeBenedette MA, Tcherepanova IY, Ostalecki C, Pommer AJ, Becker C, Günther C, Zinser E, Mak TW, Steinkasserer A, Lechmann M. Soluble CD83 ameliorates experimental colitis in mice. Mucosal Immunol 2014; 7:1006-18. [PMID: 24424524 DOI: 10.1038/mi.2013.119] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 12/02/2013] [Indexed: 02/04/2023]
Abstract
The physiological balance between pro- and anti-inflammatory processes is dysregulated in inflammatory bowel diseases (IBD) as in Crohn's disease and ulcerative colitis. Conventional therapy uses anti-inflammatory and immunosuppressive corticosteroids to treat acute-phase symptoms. However, low remission rate and strong side effects of these therapies are not satisfying. Thus, there is a high medical need for new therapeutic strategies. Soluble CD83, the extracellular domain of the transmembrane CD83 molecule, has been reported to have interesting therapeutic and immunosuppressive properties by suppressing dendritic cell (DC)-mediated T-cell activation and inducing tolerogenic DCs. However, the expression and function of CD83 in IBD is still unknown. Here, we show that CD83 expression is upregulated by different leukocyte populations in a chemical-induced murine colitis model. Furthermore, in this study the potential of sCD83 to modulate colitis using an experimental murine colitis model was investigated. Strikingly, sCD83 ameliorated the clinical disease symptoms, drastically reduced mortality, and strongly decreased inflammatory cytokine expression in mesenteric lymph nodes and colon. The infiltration of macrophages and granulocytes into colonic tissues was vigorously inhibited. Mechanistically, we could show that sCD83-induced expression of indolamine 2,3-dioxygenase is essential for its protective effects.
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Affiliation(s)
- J Eckhardt
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - S Kreiser
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - M Döbbeler
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - C Nicolette
- Argos Therapeutics, Durham, North Carolina, USA
| | | | | | - C Ostalecki
- Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - A J Pommer
- Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - C Becker
- Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany
| | - C Günther
- Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany
| | - E Zinser
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - T W Mak
- The Campbell Family Institute for Breast Cancer Research at Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
| | - A Steinkasserer
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
| | - M Lechmann
- Department of Immune Modulation at the Department of Dermatology, University Hospital Erlangen, Erlangen, Germany
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Dietel B, Muench R, Altendorf R, Cicha I, Steinkasserer A, Zinser E, Kerek F, Achenbach S, Garlichs C. Maturation of dendritic cells is involved in the progression of atherosclerosis in ApoE-deficient mice. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p2402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Leber R, Landl K, Zinser E, Ahorn H, Spök A, Kohlwein SD, Turnowsky F, Daum G. Dual localization of squalene epoxidase, Erg1p, in yeast reflects a relationship between the endoplasmic reticulum and lipid particles. Mol Biol Cell 1998; 9:375-86. [PMID: 9450962 PMCID: PMC25265 DOI: 10.1091/mbc.9.2.375] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Squalene epoxidase, encoded by the ERG1 gene in yeast, is a key enzyme of sterol biosynthesis. Analysis of subcellular fractions revealed that squalene epoxidase was present in the microsomal fraction (30,000 x g) and also cofractionated with lipid particles. A dual localization of Erg1p was confirmed by immunofluorescence microscopy. On the basis of the distribution of marker proteins, 62% of cellular Erg1p could be assigned to the endoplasmic reticulum and 38% to lipid particles in late logarithmic-phase cells. In contrast, sterol Delta24-methyltransferase (Erg6p), an enzyme catalyzing a late step in sterol biosynthesis, was found mainly in lipid particles cofractionating with triacylglycerols and steryl esters. The relative distribution of Erg1p between the endoplasmic reticulum and lipid particles changes during growth. Squalene epoxidase (Erg1p) was absent in an erg1 disruptant strain and was induced fivefold in lipid particles and in the endoplasmic reticulum when the ERG1 gene was overexpressed from a multicopy plasmid. The amount of squalene epoxidase in both compartments was also induced approximately fivefold by treatment of yeast cells with terbinafine, an inhibitor of the fungal squalene epoxidase. In contrast to the distribution of the protein, enzymatic activity of squalene epoxidase was only detectable in the endoplasmic reticulum but was absent from isolated lipid particles. When lipid particles of the wild-type strain and microsomes of an erg1 disruptant were mixed, squalene epoxidase activity was partially restored. These findings suggest that factor(s) present in the endoplasmic reticulum are required for squalene epoxidase activity. Close contact between lipid particles and endoplasmic reticulum may be necessary for a concerted action of these two compartments in sterol biosynthesis.
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Affiliation(s)
- R Leber
- Institut für Biochemie und Lebensmittelchemie and SFB Biomembrane Research Center, Technische Universität Graz, 1121 Vienna, Austria
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Affiliation(s)
- E Zinser
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Leber R, Zinser E, Hrastnik C, Paltauf F, Daum G. Export of steryl esters from lipid particles and release of free sterols in the yeast, Saccharomyces cerevisiae. Biochim Biophys Acta 1995; 1234:119-26. [PMID: 7880852 DOI: 10.1016/0005-2736(94)00270-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fatty acyl esters of the yeast specific sterol, ergosterol, are exclusively stored in lipid particles. Under conditions of sterol deficiency, e.g., in the presence of terbinafine, an inhibitor of fungal squalene epoxidase, steryl esters are hydrolyzed, and sterols are set free for membrane formation. Lipid particles do not contain steryl-ester hydrolase activity themselves; the highest specific activity of this enzyme is found in the plasma membrane. Therefore, steryl esters have to be exported from lipid particles to their site of hydrolytic cleavage. This process of translocation and metabolic conversion was studied in vivo. Addition of nocodazole to terbinafine-treated cells did not disturb the mobilization of steryl esters, indicating that this process is not mediated by microtubuli-dependent vesicle flux. Under the influence of inhibitors of cellular energy production (azide and fluoride) and protein biosynthesis (cycloheximide) mobilization of steryl esters came to an halt. These results support the view that ongoing membrane proliferation may be a driving force for the release of sterols from steryl esters of lipid particles.
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Affiliation(s)
- R Leber
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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9
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Abstract
Lipid particles of the yeast, Saccharomyces cerevisiae, were isolated to high purity and their components were analysed. The hydrophobic core of this organelle consists of triacylglycerols and steryl esters, which are almost exclusively located to that compartment. Lipid particles are stabilized by a surface membrane consisting of phospholipids and proteins. Electron microscopy confirmed the purity of the preparations and the proposed structure deduced from biochemical experiments. Major proteins of lipid particles have molecular weights of 72, 52, 43 and 34 kDa, respectively. The 43 kDa protein reacts with an antiserum against human apolipoprotein AII. In lipid particles of the yeast mutant strain S. cerevisiae erg6, which is deficient in sterol delta 24-methyltransferase, this protein is missing thereby identifying the protein and confirming our previous finding (Zinser et al., 1993) that sterol delta 24-methylation is associated with lipid particles. A possible involvement of surface proteins of lipid particles in the interaction with other organelles is discussed with respect to sterol translocation in yeast.
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Affiliation(s)
- R Leber
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Hechtberger P, Zinser E, Saf R, Hummel K, Paltauf F, Daum G. Characterization, quantification and subcellular localization of inositol-containing sphingolipids of the yeast, Saccharomyces cerevisiae. Eur J Biochem 1994; 225:641-9. [PMID: 7957179 DOI: 10.1111/j.1432-1033.1994.00641.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In yeast, as in higher eukaryotic cells, sphingolipids are essential membrane components. The yeast, Saccharomyces cerevisiae, contains three classes of sphingolipids, inositolphosphorylceramide (InsPCer), mannosylinositolphosphorylceramide (ManInsPCer) and mannosyldiinositolphosphorylceramide (ManPIns2PCer). As a prerequisite to localize these sphingolipids in subcellular membranes, authentic standards of the respective lipids were isolaed and characterized using biochemical methods and electrospray ionization mass spectrometry. The complete set of yeast subcellular membranes was isolated at high purity, and sphingolipids were extracted. InsPCer, ManInsPCer, and ManPIns2PCer were separated by thin-layer chromatography, stained and densitometrically scanned along with the respective standards. These methods enable a complete overview of the subcellular distribution of yeast sphingolipids to be obtained, as far as is known, for the first time. InsPCer was highly enriched in Golgi and vacuolar membranes, whereas the largest amounts of ManInsPCer and ManPIns2PCer were found in the plasma membrane. The presence of inositol-containing sphingolipids in organelles of the protein-secretory pathway strongly supports the notion that protein secretion and intracellular trafficking of sphingolipids are linked processes.
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Affiliation(s)
- P Hechtberger
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Small P, Blankenhorn D, Welty D, Zinser E, Slonczewski JL. Acid and base resistance in Escherichia coli and Shigella flexneri: role of rpoS and growth pH. J Bacteriol 1994; 176:1729-37. [PMID: 8132468 PMCID: PMC205261 DOI: 10.1128/jb.176.6.1729-1737.1994] [Citation(s) in RCA: 292] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Escherichia coli K-12 strains and Shigella flexneri grown to stationary phase can survive several hours at pH 2 to 3, which is considerably lower than the acid limit for growth (about pH 4.5). A 1.3-kb fragment cloned from S. flexneri conferred acid resistance on acid-sensitive E. coli HB101; sequence data identified the fragment as a homolog of rpoS, the growth phase-dependent sigma factor sigma 38. The clone also conferred acid resistance on S. flexneri rpoS::Tn10 but not on Salmonella typhimurium. E. coli and S. flexneri strains containing wild-type rpoS maintained greater internal pH in the face of a low external pH than strains lacking functional rpoS, but the ability to survive at low pH did not require maintenance of a high transmembrane pH difference. Aerobic stationary-phase cultures of E. coli MC4100 and S. flexneri 3136, grown initially at an external pH range of 5 to 8, were 100% acid resistant (surviving 2 h at pH 2.5). Aerobic log-phase cultures grown at pH 5.0 were acid resistant; survival decreased 10- to 100-fold as the pH of growth was increased to pH 8.0. Extended growth in log phase also decreased acid resistance substantially. Strains containing rpoS::Tn10 showed partial acid resistance when grown at pH 5 to stationary phase; log-phase cultures showed < 0.01% acid resistance. When grown anaerobically at low pH, however, the rpoS::Tn10 strains were acid resistant. E. coli MC4100 also showed resistance at alkaline pH outside the growth range (base resistance). Significant base resistance was observed up to pH 10.2. Base resistance was diminished by rpoS::Tn10 and by the presence of Na+. Base resistance was increased by an order of magnitude for stationary-phase cultures grown in moderate base (pH 8) compared with those grown in moderate acid (pH 5). Anaerobic growth partly restored base resistance in cultures grown at pH 5 but not in those grown at pH 8. Thus, both acid resistance and base resistance show dependence on growth pH and are regulated by rpoS under certain conditions. For acid resistance, and in part for base resistance, the rpoS requirement can be overcome by anaerobic growth in moderate acid.
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Affiliation(s)
- P Small
- Laboratory of Vectors and Pathogens, National Institute of Allergy and Infections Disease, Hamilton, Montana 59840
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Tahotna D, Hapala I, Zinser E, Flekl W, Paltauf F, Daum G. Two yeast peroxisomal proteins crossreact with an antiserum against human sterol carrier protein 2 (SCP-2). Biochim Biophys Acta 1993; 1148:173-6. [PMID: 8499465 DOI: 10.1016/0005-2736(93)90175-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An antibody raised against human sterol carrier protein 2 (SCP-2) crossreacts with two yeast peroxisomal proteins. These proteins have apparent molecular weights of 35 and 58 kDa. Subfractionation of peroxisomes revealed that the 58 kDa species is a soluble matrix protein, whereas the 35 kDa protein is membrane bound. Treatment of isolated peroxisomal membranes with 0.25 M KCl released the 35 kDa crossreactive protein into the soluble supernatant. However, lipid transfer activity could be attributed neither to the 35 kDa nor to the 58 kDa protein.
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Affiliation(s)
- D Tahotna
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Abstract
Organelles of the yeast Saccharomyces cerevisiae were isolated and analyzed for sterol composition and the activity of three enzymes involved in sterol metabolism. The plasma membrane and secretory vesicles, the fractions with the highest sterol contents, contain ergosterol as the major sterol. In other subcellular membranes, which exhibit lower sterol contents, intermediates of the sterol biosynthetic pathway were found at higher percentages. Lipid particles contain, in addition to ergosterol, large amounts of zymosterol, fecosterol, and episterol. These sterols are present esterified with long-chain fatty acids in this subcellular compartment, which also harbors practically all of the triacylglycerols present in the cell but very little phospholipids and proteins. Sterol delta 24-methyltransferase, an enzyme that catalyzes one of the late steps in sterol biosynthesis, was localized almost exclusively in lipid particles. Steryl ester formation is a microsomal process, whereas steryl ester hydrolysis occurs in the plasma membrane and in secretory vesicles. The fact that synthesis, storage, and hydrolysis of steryl esters occur in different subcellular compartments gives rise to the view that ergosteryl esters of lipid particles might serve as intermediates for the supply of ergosterol from internal membranes to the plasma membrane.
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Affiliation(s)
- E Zinser
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Hohenwarter O, Zinser E, Schmatz C, Rüker F, Katinger H. Influence of transfected SV40 early region on growth and differentiation of human endothelial cells. J Biotechnol 1992; 25:349-56. [PMID: 1369397 DOI: 10.1016/0168-1656(92)90167-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Endothelial cells isolated from human umbilical veins show a limited in vitro life span of about 40 population doublings. Cell division is dependent on the presence of endothelial cell growth factor in the culture medium. We have transfected primary endothelial cells with a plasmid containing the early region of SV40 virus. Large T positive cells were obtained which grew in the absence of endothelial cell growth factor at low serum concentrations and showed a prolonged lifespan. Expression of von Willebrand factor and SV40 large T antigen was detected simultaneously in transfected cells.
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Affiliation(s)
- O Hohenwarter
- Institute of Applied Microbiology, University of Agriculture, Vienna, Austria
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15
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Simbeni R, Pon L, Zinser E, Paltauf F, Daum G. Mitochondrial membrane contact sites of yeast. Characterization of lipid components and possible involvement in intramitochondrial translocation of phospholipids. J Biol Chem 1991; 266:10047-9. [PMID: 2037561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Submitochondrial membrane fractions from yeast that are enriched in inner and outer membrane contact sites were analyzed with respect to their lipid composition. Characteristic features were the significantly reduced content of phosphatidylinositol, the decreased amount of phosphatidylcholine, and the enrichment in phosphatidylethanolamine and cardiolipin. Coisolation of phosphatidylserine synthase with the outer membrane portion and enrichment of phosphatidylserine decarboxylase in the inner membrane portion of isolated contact sites provided the basis for a metabolic assay to study phosphatidylserine transfer from the outer to the inner mitochondrial membrane via contact sites. The efficient conversion to [3H]phosphatidylethanolamine of [3H]phosphatidylserine synthesized from [3H]serine in situ supports the notion that mitochondrial membrane contact sites are zones of intramitochondrial translocation of phosphatidylserine.
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Affiliation(s)
- R Simbeni
- Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Austria
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Paltauf F, Zinser E, Daum G. Utilization of exogenous glycerophosphodiesters and glycerol 3-phosphate by inositol-starved yeast, Saccharomyces uvarum. Biochim Biophys Acta 1985; 835:322-30. [PMID: 2988639 DOI: 10.1016/0005-2760(85)90288-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Inositol-starved Saccharomyces uvarum cells hydrolyse exogenous glycerophosphodiesters to glycerol 3-phosphate and the corresponding alcohol. Glycerophosphodiesterase activity is highest with glycerophosphoinositol as the substrate, followed by glycerophosphoethanolamine and glycerophosphocholine; the artificial substrate for phosphodiesterases, bis-p-nitrophenylphosphate,is hydrolysed at a similar rate as compared with glycerophosphoinositol. Competition experiments suggest that distinct phosphodiesterases are involved in the hydrolysis of the respective substrates. An Mg2+-dependent glycerophosphate phosphohydrolase with a pH-optimum around neutral cleaves glycerol 3-phosphate to glycerol and orthophosphate. The latter is taken up into cells without first entering the pool of orthophosphate present in the growth medium. Accessibility to substrates with whole cells, adhesion of enzymes to spheroplasts, and solubilization of enzymes by treatment of whole cells with Triton X-100 under mild conditions suggest that phosphodiesterases and glycerol-3-phosphate phosphohydrolase are loosely associated with the outer side of the yeast plasma membrane. Enzyme activities are only marginal in inositol-supplemented cells, but are derepressed not only by inositol deficiency, but also by starvation of orthophosphate.
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Abstract
Activities of several phosphohydrolases are significantly enhanced when cells of the inositol-requiring yeast, Saccharomyces uvarum ATCC 9080, are deprived of inositol. This effect is most pronounced for the external acid phosphatase and cannot be explained simply by limitation of cellular growth, because starvation for vitamins or sulphate has no effect on acid phosphatase activities. Excessive secretion of acid phosphatase by spheroplasts prepared from inositol-deficient cells is greatly reduced when the spheroplast medium is supplemented with inositol and is immediately suppressed by the addition of cycloheximide. These results together with data obtained from experiments with whole cells, employing cycloheximide and actinomycin D, point to a regulatory effect of inositol limitation at the level of transcription. The external enzymes beta-D-fructofuranosidase, alpha-D-galactosidase and L-asparaginase, and the vacuolar enzyme carboxypeptidase Y are not affected by inositol deficiency indicating that inositol deficiency has no general effect on protein secretion.
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