Pre- and Peri-/Post-Compaction Follistatin Treatment Increases In Vitro Production of Cattle Embryos.

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Guo Zhenhua

Full Text Available Our previous studies demonstrated that maternal (oocyte derived follistatin (FST expression is positively associated with bovine oocyte competence and exogenous follistatin treatment during the pre-compaction period of development (d 1-3 post insemination is stimulatory to bovine early embryogenesis in vitro [blastocyst rates and cell numbers/allocation to trophectoderm (TE]. In the present study, bovine embryos were treated with exogenous follistatin during d 1-3, d 4-7 and d 1-7 post insemination to test the hypothesis that embryotropic effects of exogenous follistatin are specific to the pre-compaction period (d 1-3 of early embryogenesis. Follistatin treatment during d 4-7 (peri-/post-compaction period of embryo culture increased proportion of embryos reaching blastocyst and expanded blastocyst stage and total cell numbers compared to controls, but blastocyst rates and total cell numbers were lower than observed following d 1-3 (pre-compaction follistatin treatment. Follistatin supplementation during d 1-7 of embryo culture increased development to blastocyst and expanded blastocyst stages and blastocyst total cell numbers compared to d 1-3 and d 4-7 follistatin treatment and untreated controls. A similar increase in blastocyst CDX2 mRNA and protein (TE cell marker was observed in response to d 1-3, d 4-7 and d 1-7 follistatin treatment. However, an elevation in blastocyst BMP4 protein (TE cell regulator was observed in response to d 1-3 and d 1-7, but not d 4-7 (peri-/post-compaction follistatin treatment. In summary, our study revealed the potential utility of follistatin treatment for increasing the success rate of in vitro embryo production in cattle. Such results also expand our understanding of the embryotropic actions of follistatin and demonstrate that follistatin actions on blastocyst development and cell allocation to the TE layer are not specific to the pre-compaction period.

Follistatin during pregnancy and its potential role as an ovarian suppressing agent.

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Köninger, Angela; Schmidt, Börge; Damaske, Daniela; Birdir, Cahit; Enekwe, Antje; Kimmig, Rainer; Strowitzki, Thomas; Gellhaus, Alexandra

2017-05-01

Ovarian quiescence is a common condition during pregnancy. In vitro, follistatin, an antagonist of follicle-stimulating hormone, blocks follicular development at early stages, and its serum levels increase during pregnancy. A possible surrogate biomarker of ovarian arrest during pregnancy is a decrease in anti-mullerian hormone (AMH) levels followed by an increase in these levels on the second day after labor. The purpose of this study was to determine whether follistatin could act as an ovarian-suppressing agent during pregnancy. Follistatin levels and AMH levels were determined at various stages of pregnancy and postpartum. The follistatin and AMH levels of 69 patients were retrospectively determined with the AMH Gen II ELISA and with the Human Follistatin Quantikine ELISA Kit. For 49 patients, samples were available from various trimesters for cross-sectional analysis; for the other 20, samples were available longitudinally from day one before labor and then daily on days 1 through 4 after labor. Statistical significance was determined with linear regression, the Friedman rank sum test and the Wilcoxon-Nemenyi-McDonald-Thompson post hoc test. The behavior of follistatin levels was exactly opposite that of AMH levels: Follistatin levels increased significantly during pregnancy and on the first day after parturition but declined afterwards, whereas AMH levels decreased significantly during pregnancy and increased after labor. Follistatin can induce ovarian arrest during pregnancy. Copyright © 2017 Elsevier B.V. All rights reserved.

Primary structure of the human follistatin precursor and its genomic organization

International Nuclear Information System (INIS)

Shimasaki, Shunichi; Koga, Makoto; Esch, F.

1988-01-01

Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. By use of the recently characterized porcine follistatin cDNA as a probe to screen a human testis cDNA library and a genomic library, the structure of the complete human follistatin precursor as well as its genomic organization have been determined. Three of eight cDNA clones that were sequenced predicted a precursor with 344 amino acids, whereas the remaining five cDNA clones encoded a 317 amino acid precursor, resulting from alternative splicing of the precursor mRNA. Mature follistatins contain four contiguous domains that are encoded by precisely separated exons; three of the domains are highly similar to each other, as well as to human epidermal growth factor and human pancreatic secretory trypsin inhibitor. The genomic organization of the human follistatin is similar to that of the human epidermal growth factor gene and thus supports the notion of exon shuffling during evolution

Staphylococcal superantigen-like 5 activates platelets and supports platelet adhesion under flow conditions, which involves glycoprotein Ib alpha and alpha(IIb)beta(3)

NARCIS (Netherlands)

De Haas, C. J. C.; Weeterings, C.; Vughs, M. M.; De Groot, P. G.; Van Strijp, J. A.; Lisman, T.

2009-01-01

Objectives: Staphylococcal superantigen-like 5 (SSL5) is an exoprotein secreted by Staphylococcus aureus that has been shown to inhibit neutrophil rolling over activated endothelial cells via a direct interaction with P-selectin glycoprotein ligand 1 (PSGL-1). Methods and Results: When purified

Follistatin allows efficient retroviral-mediated gene transfer into rat liver

International Nuclear Information System (INIS)

Borgnon, Josephine; Djamouri, Fatima; Lorand, Isabelle; Rico, Virginie Di; Loux, Nathalie; Pages, Jean-Christophe; Franco, Dominique; Capron, Frederique; Weber, Anne

2005-01-01

Retroviral vectors are widely used tools for gene therapy. However, in vivo gene transfer is only effective in dividing cells, which, in liver, requires a regenerative stimulus. Follistatin is effective in promoting liver regeneration after 90% and 70% hepatectomy in rats. We studied its efficacy on liver regeneration and retroviral-mediated gene delivery in 50% hepatectomized rats. When human recombinant follistatin was infused into the portal vein immediately after 50% hepatectomy, hepatocyte proliferation was significantly higher than in control 50% hepatectomized rats. A single injection of virus particles administered 23 h after follistatin infusion resulted in more than 20% gene transduction efficiency in hepatocytes compared to 3% in control rats. It is concluded that a single injection of follistatin induces onset of proliferation in 50% hepatectomized rats and allows efficient retroviral-mediated gene transfer to the liver

Over-expression of Follistatin-like 3 attenuates fat accumulation and improves insulin sensitivity in mice

DEFF Research Database (Denmark)

Brandt, Claus; Hansen, Rasmus Hvass; Hansen, Jakob Bondo

2015-01-01

-fat feeding. Body weight, food intake, fat accumulation by MR scanning, and glucose, insulin and glucagon tolerance were evaluated, as was the response in body weight and metabolic parameters to 24h fasting. Effects of fstl3 on pancreatic insulin and glucagon content, and pancreatic islet morphology were......OBJECTIVE: Follistatin-like 3 (fstl3), a natural inhibitor of members of the TGF-β family, increases during resistance training in human plasma. Fstl3 primarily binds myostatin and activin A, and thereby inhibits their functions. We hypothesize that blocking myostatin and activin A signalling....../glucagon ratio. Accordingly, fstl3 transfection improved counter-regulation to 24h fasting. CONCLUSION: Fstl3 over-expression regulates insulin and glucagon sensitivities through increased muscular insulin action, as well as increased hepatic glucagon sensitivity and pancreatic glucagon content....

Modulation of follistatin and myostatin propeptide by anabolic steroids and gender.

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Mosler, S; Geisler, S; Hengevoss, J; Schiffer, T; Piechotta, M; Adler, M; Diel, P

2013-07-01

The purpose of this pilot study was to investigate the impact of training, anabolic steroids and endogenous hormones on myostatin-interacting proteins in order to identify manipulations of myostatin signalling. To identify whether analysis of the myostatin interacting proteins follistatin and myostatin propeptide is suitable to detect the abuse of anabolic steroids, their serum concentrations were monitored in untrained males, bodybuilders using anabolic steroids and natural bodybuilders. In addition, we analysed follistatin and myostatin propeptide serum proteins in females during menstrual cycle. Our results showed increased follistatin concentrations in response to anabolic steroids. Furthermore, variations of sex steroid levels during the menstrual cycle had no impact on the expression of follistatin and myostatin propetide. In addition, we identified gender differences in the basal expression of the investigated proteins. In general, follistatin and myostatin propeptide concentrations were relatively stable within the same individual both in males and females. In conclusion, the current findings provide an insight into gender differences in myostatin-interacting proteins and their regulation in response to anabolic steroids and endogenous hormones. Therefore our data provide new aspects for the development of doping prevention strategies. © Georg Thieme Verlag KG Stuttgart · New York.

Follistatin-mediated skeletal muscle hypertrophy is regulated by Smad3 and mTOR independently of myostatin

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Winbanks, Catherine E.; Weeks, Kate L.; Thomson, Rachel E.; Sepulveda, Patricio V.; Beyer, Claudia; Qian, Hongwei; Chen, Justin L.; Allen, James M.; Lancaster, Graeme I.; Febbraio, Mark A.; Harrison, Craig A.; McMullen, Julie R.; Chamberlain, Jeffrey S.

2012-01-01

Follistatin is essential for skeletal muscle development and growth, but the intracellular signaling networks that regulate follistatin-mediated effects are not well defined. We show here that the administration of an adeno-associated viral vector expressing follistatin-288aa (rAAV6:Fst-288) markedly increased muscle mass and force-producing capacity concomitant with increased protein synthesis and mammalian target of rapamycin (mTOR) activation. These effects were attenuated by inhibition of mTOR or deletion of S6K1/2. Furthermore, we identify Smad3 as the critical intracellular link that mediates the effects of follistatin on mTOR signaling. Expression of constitutively active Smad3 not only markedly prevented skeletal muscle growth induced by follistatin but also potently suppressed follistatin-induced Akt/mTOR/S6K signaling. Importantly, the regulation of Smad3- and mTOR-dependent events by follistatin occurred independently of overexpression or knockout of myostatin, a key repressor of muscle development that can regulate Smad3 and mTOR signaling and that is itself inhibited by follistatin. These findings identify a critical role of Smad3/Akt/mTOR/S6K/S6RP signaling in follistatin-mediated muscle growth that operates independently of myostatin-driven mechanisms. PMID:22711699

Differential expression of follistatin and FLRG in human breast proliferative disorders

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Amaral Vania F

2009-09-01

Full Text Available Abstract Background Activins are growth factors acting on cell growth and differentiation. Activins are expressed in high grade breast tumors and they display an antiproliferative effect inducing G0/G1 cell cycle arrest in breast cancer cell lines. Follistatin and follistatin- related gene (FLRG bind and neutralize activins. In order to establish if these activin binding proteins are involved in breast tumor progression, the present study evaluated follistatin and FLRG pattern of mRNA and protein expression in normal human breast tissue and in different breast proliferative diseases. Methods Paraffin embedded specimens of normal breast (NB - n = 8; florid hyperplasia without atypia (FH - n = 17; fibroadenoma (FIB - n = 17; ductal carcinoma in situ (DCIS - n = 10 and infiltrating ductal carcinoma (IDC - n = 15 were processed for follistatin and FLRG immunohistochemistry and in situ hybridization. The area and intensity of chromogen epithelial and stromal staining were analyzed semi-quantitatively. Results Follistatin and FLRG were expressed both in normal tissue and in all the breast diseases investigated. Follistatin staining was detected in the epithelial cytoplasm and nucleus in normal, benign and malignant breast tissue, with a stronger staining intensity in the peri-alveolar stromal cells of FIB at both mRNA and protein levels. Conversely, FLRG area and intensity of mRNA and protein staining were higher both in the cytoplasm and in the nucleus of IDC epithelial cells when compared to NB, while no significant changes in the stromal intensity were observed in all the proliferative diseases analyzed. Conclusion The present findings suggest a role for follistatin in breast benign disease, particularly in FIB, where its expression was increased in stromal cells. The up regulation of FLRG in IDC suggests a role for this protein in the progression of breast malignancy. As activin displays an anti-proliferative effect in human mammary cells, the

Circulating Follistatin Is Liver-Derived and Regulated by the Glucagon-to-Insulin Ratio

DEFF Research Database (Denmark)

Hansen, Jakob S; Rutti, Sabine; Arous, Caroline

2016-01-01

CONTEXT: Follistatin is a plasma protein recently reported to increase under conditions with negative energy balance, such as exercise and fasting in humans. Currently, the perception is that circulating follistatin is a result of para/autocrine actions from various tissues. The large and acute i...

Development of a radioimmunoassay for 'Tamm-Horsfall-like' glycoprotein in serum and cerebrospinal fluid

International Nuclear Information System (INIS)

Hartmann, L.; Bringuier, A.-F.; Schuller, E.

1983-01-01

Affinity chromatography purification was combined with a radioimmunoassay for 'Tamm-Horsfall-like' glycoprotein. This enabled serum comcentrations to be established and to demonstrate its presence in cerebrospinal fluid for the first time. This assay method used in different circumstances suggests a multifocal synthesis. Nevertheless, urinary Tamm-Horsfall glycoprotein so far must be distinguished from the serum or cerebrospinal fluid Tamm-Horsfall-like glycoprotein. (Auth.)

Spatial Localization of the Ebola Virus Glycoprotein Mucin-Like Domain Determined by Cryo-Electron Tomography

OpenAIRE

Tran, Erin E. H.; Simmons, James A.; Bartesaghi, Alberto; Shoemaker, Charles J.; Nelson, Elizabeth; White, Judith M.; Subramaniam, Sriram

2014-01-01

The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function.

Myostatin, follistatin and activin type II receptors are highly expressed in adenomyosis.

Science.gov (United States)

Carrarelli, Patrizia; Yen, Chih-Fen; Arcuri, Felice; Funghi, Lucia; Tosti, Claudia; Wang, Tzu-Hao; Huang, Joseph S; Petraglia, Felice

2015-09-01

To evaluate the expression pattern of activins and related growth factor messenger RNA (mRNA) levels in adenomyotic nodules and in their endometrium. Prospective study. University hospital. Symptomatic premenopausal women scheduled to undergo hysterectomy for adenomyosis. Samples from adenomyotic nodules and homologous endometria were collected. Endometrial tissue was also obtained from a control group. Quantitative real-time polymerase chain reaction (PCR) analysis and immunohistochemical localization of activin-related growth factors (activin A, activin B, and myostatin), binding protein (follistatin), antagonists (inhibin-α, cripto), and receptors (ActRIIa, ActRIIb) were performed. Myostatin mRNA levels in adenomyotic nodule were higher than in eutopic endometrium and myostatin, activin A, and follistatin concentrations were higher than in control endometrium. No difference was observed for inhibin-α, activin B, and cripto mRNA levels. Increased mRNA levels of ActRIIa and ActRIIb were observed in adenomyotic nodules compared with eutopic endometrium and control endometrium. Immunofluorescent staining for myostatin and follistatin confirmed higher protein expression in both glands and stroma of patients with adenomyosis than in controls. The present study showed for the first time that adenomyotic tissues express high levels of myostatin, follistatin, and activin A (growth factors involved in proliferation, apoptosis, and angiogenesis). Increased expression of their receptors supports the hypothesis of a possible local effect of these growth factors in adenomyosis. The augmented expression of ActRIIa, ActRIIb, and follistatin in the endometrium of these patients may play a role in adenomyosis-related infertility. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The elicitin-like glycoprotein, ELI025, is secreted by the pathogenic oomycete Pythium insidiosum and evades host antibody responses.

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Tassanee Lerksuthirat

Full Text Available Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025 was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum's culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis.

Spatial localization of the Ebola virus glycoprotein mucin-like domain determined by cryo-electron tomography.

Science.gov (United States)

Tran, Erin E H; Simmons, James A; Bartesaghi, Alberto; Shoemaker, Charles J; Nelson, Elizabeth; White, Judith M; Subramaniam, Sriram

2014-09-01

The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Tight interplay in early pregnancy between follistatin and anti-mullerian hormone in women with polycystic ovarian syndrome (PCOS).

Science.gov (United States)

Köninger, Angela; Kampmeier, Antje; Mach, Pawel; Schmidt, Boerge; Strowitzki, Thomas; Kimmig, Rainer; Gellhaus, Alexandra

2018-05-01

Follistatin levels increase during the course of pregnancy and may play a role in ovarian arrest, reflected by the simultaneous decrease of anti-mullerian-hormone (AMH) levels. The aim of the study was to investigate AMH and follistatin levels during the hormonal window at the beginning of pregnancy. Since both parameters are described as deregulated in polycystic ovarian syndrome (PCOS), subgroup analysis of PCOS patients may additionally elucidate their interplay and effects on ovarian activity. Serum samples were retrospectively analyzed using the AMH Gen II ELISA and the Human Follistatin Quantikine ELISA Kit. Samples were collected longitudinally from 57 patients (32 with PCOS and 25 controls) before conception and during the first trimester. In 18 patients, measurements from the early and the late first trimester were available. Potential associations of AMH and follistatin levels with PCOS-related parameters were compared between the subgroups as well as longitudinally before and in the first trimester of pregnancy. For statistical analysis, the Spearman's correlation, Wilcoxon test, t test, Friedman test and multiple linear regression analysis was performed. In contrast to AMH, follistatin levels differed not between controls and PCOS patients before and in pregnancy. In both subgroups, AMH levels significantly decreased and follistatin levels significantly increased in longitudinally performed measurements before conceiving and in the first trimester of pregnancy. Follistatin levels are not suited as a biomarker for PCOS, but could be involved in suppressing ovarian activity, as reflected by AMH levels at the beginning of pregnancy.

Effects of the activin A-myostatin-follistatin system on aging bone and muscle progenitor cells

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Bowser, Matthew; Herberg, Samuel; Arounleut, Phonepasong; Shi, Xingming; Fulzele, Sadanand; Hill, William D.; Isales, Carlos M.; Hamrick, Mark W.

2013-01-01

The activin A-myostatin-follistatin system is thought to play an important role in the regulation of muscle and bone mass throughout growth, development, and aging; however, the effects of these ligands on progenitor cell proliferation and differentiation in muscle and bone are not well understood. In addition, age-associated changes in the relative expression of these factors in musculoskeletal tissues have not been described. We therefore examined changes in protein levels of activin A, follistatin, and myostatin (GDF-8) in both muscle and bone with age in C57BL6 mice using ELISA. We then investigated the effects of activin A, myostatin and follistatin on the proliferation and differentiation of primary myoblasts and mouse bone marrow stromal cells (BMSCs) in vitro. Myostatin levels and the myostatin:follistatin ratio increased with age in the primarily slow-twitch mouse soleus muscle, whereas the pattern was reversed with age in the fast-twitch extensor digitorum longus muscle. Myostatin levels and the myostatin: follistatin ratio increased significantly (+75%) in mouse bone marrow with age, as did activin A levels (+17%). Follistatin increased the proliferation of primary myoblasts from both young and aged mice, whereas myostatin increased proliferation of younger myoblasts but decreased proliferation of older myoblasts. Myostatin reduced proliferation of both young and aged BMSCs in a dose-dependent fashion, and activin A increased mineralization in both young and aged BMSCs. Together these data suggest that aging in mice is accompanied by changes in the expression of activin A and myostatin, as well as changes in the response of bone and muscle progenitor cells to these factors. Myostatin appears to play a particularly important role in the impaired proliferative capacity of muscle and bone progenitor cells from aged mice. PMID:23178301

A Carbohydrate Moiety of Secreted Stage-Specific Glycoprotein 4 Participates in Host Cell Invasion by Trypanosoma cruzi Extracellular Amastigotes

Science.gov (United States)

Florentino, Pilar T. V.; Real, Fernando; Orikaza, Cristina M.; da Cunha, Julia P. C.; Vitorino, Francisca N. L.; Cordero, Esteban M.; Sobreira, Tiago J. P.; Mortara, Renato A.

2018-01-01

Trypanosoma cruzi is the etiologic agent of Chagas’ disease. It is known that amastigotes derived from trypomastigotes in the extracellular milieu are infective in vitro and in vivo. Extracellular amastigotes (EAs) have a stage-specific surface antigen called Ssp-4, a GPI-anchored glycoprotein that is secreted by the parasites. By immunoprecipitation with the Ssp-4-specific monoclonal antibodies (mAb) 2C2 and 1D9, we isolated the glycoprotein from EAs. By mass spectrometry, we identified the core protein of Ssp-4 and evaluated mRNA expression and the presence of Ssp-4 carbohydrate epitopes recognized by mAb1D9. We demonstrated that the carbohydrate epitope recognized by mAb1D9 could promote host cell invasion by EAs. Although infectious EAs express lower amounts of Ssp-4 compared with less-infectious EAs (at the mRNA and protein levels), it is the glycosylation of Ssp-4 (identified by mAb1D9 staining only in infectious strains and recognized by galectin-3 on host cells) that is the determinant of EA invasion of host cells. Furthermore, Ssp-4 is secreted by EAs, either free or associated with parasite vesicles, and can participate in host-cell interactions. The results presented here describe the possible role of a carbohydrate moiety of T. cruzi surface glycoproteins in host cell invasion by EA forms, highlighting the potential of these moieties as therapeutic and vaccine targets for the treatment of Chagas’ disease. PMID:29692765

Pirenzepine block of ACh-induced mucus secretion in tracheal submucosal gland cells

International Nuclear Information System (INIS)

Farley, J.M.; Dwyer, T.M.

1991-01-01

Muscarinic stimulation of mucus secretion, as measured by the release of [ 3 H]glycoprotein, was studied in explants from the tracheal epithelium of weanling swine. The mucus glycoprotein secretion was transient, ceasing within the first 10 min of a continuous exposure to 100 μM ACh. Increasing the solutions' osmotic pressure did not alter basal mucus glycoprotein secretion. Mucus glycoprotein secretion was inhibited by 2-10 μM PZP, indicting that the M 3 muscarinic receptors mediate cholinergic stimulation of mucus production

A Carbohydrate Moiety of Secreted Stage-Specific Glycoprotein 4 Participates in Host Cell Invasion by Trypanosoma cruzi Extracellular Amastigotes

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Pilar T. V. Florentino

2018-04-01

Full Text Available Trypanosoma cruzi is the etiologic agent of Chagas’ disease. It is known that amastigotes derived from trypomastigotes in the extracellular milieu are infective in vitro and in vivo. Extracellular amastigotes (EAs have a stage-specific surface antigen called Ssp-4, a GPI-anchored glycoprotein that is secreted by the parasites. By immunoprecipitation with the Ssp-4-specific monoclonal antibodies (mAb 2C2 and 1D9, we isolated the glycoprotein from EAs. By mass spectrometry, we identified the core protein of Ssp-4 and evaluated mRNA expression and the presence of Ssp-4 carbohydrate epitopes recognized by mAb1D9. We demonstrated that the carbohydrate epitope recognized by mAb1D9 could promote host cell invasion by EAs. Although infectious EAs express lower amounts of Ssp-4 compared with less-infectious EAs (at the mRNA and protein levels, it is the glycosylation of Ssp-4 (identified by mAb1D9 staining only in infectious strains and recognized by galectin-3 on host cells that is the determinant of EA invasion of host cells. Furthermore, Ssp-4 is secreted by EAs, either free or associated with parasite vesicles, and can participate in host-cell interactions. The results presented here describe the possible role of a carbohydrate moiety of T. cruzi surface glycoproteins in host cell invasion by EA forms, highlighting the potential of these moieties as therapeutic and vaccine targets for the treatment of Chagas’ disease.

Pituitary glycoprotein hormone a-subunit secretion by cirrhotic patients

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Oliveira M.C.

1999-01-01

Full Text Available Secretion of the a-subunit of pituitary glycoprotein hormones usually follows the secretion of intact gonadotropins and is increased in gonadal failure and decreased in isolated gonadotropin deficiency. The aim of the present study was to determine the levels of the a-subunit in the serum of patients with cirrhosis of the liver and to compare the results obtained for eugonadal cirrhotic patients with those obtained for cirrhotic patients with hypogonadotropic hypogonadism. Forty-seven of 63 patients with cirrhosis (74.6% presented hypogonadism (which was central in 45 cases and primary in 2, 7 were eugonadal, and 9 women were in normal menopause. The serum a-subunit was measured by the fluorimetric method using monoclonal antibodies. Cross-reactivity with LH, TSH, FSH and hCG was 6.5, 1.2, 4.3 and 1.1%, respectively, with an intra-assay coefficient of variation (CV of less than 5% and an interassay CV of 5%, and sensitivity limit of 4 ng/l. The serum a-subunit concentration ranged from 36 to 6253 ng/l, with a median of 273 ng/l. The median was 251 ng/l for patients with central hypogonadism and 198 ng/l for eugonadal patients. The correlation between the a-subunit and basal LH levels was significant both in the total sample (r = 0.48, P<0.01 and in the cirrhotic patients with central hypogonadism (r = 0.33, P = 0.02. Among men with central hypogonadism there was a negative correlation between a-subunit levels and total testosterone levels (r = 0.54, P<0.01 as well as free testosterone levels (r = -0.53, P<0.01. In conclusion, although the a-subunit levels are correlated with LH levels, at present they cannot be used as markers for hypogonadism in patients with cirrhosis of the liver.

Sheng-ji Hua-yu formula promotes diabetic wound healing of re-epithelization via Activin/Follistatin regulation.

Science.gov (United States)

Kuai, Le; Zhang, Jing-Ting; Deng, Yu; Xu, Shun; Xu, Xun-Zhe; Wu, Min-Feng; Guo, Dong-Jie; Chen, Yu; Wu, Ren-Jie; Zhao, Xing-Qiang; Nian, Hua; Li, Bin; Li, Fu-Lun

2018-01-29

Sheng-ji Hua-yu(SJHY) formula is one of the most useful Traditional Chinese medicine (TCM) in the treatment of the delayed diabetic wound. However, elucidating the related molecular biological mechanism of how the SJHY Formula affects excessive inflammation in the process of re-epithelialization of diabetic wound healing is a task urgently needed to be fulfilled. The objectives of this study is to evaluate the effect of antagonisic expression of pro-/anti-inflammatory factors on transforming growth factor-β(TGF-β) superfamily (activin and follistatin) in the process of re-epithelialization of diabetic wound healing in vivo, and to characterize the involvement of the activin/follistatin protein expression regulation, phospho-Smad (pSmad2), and Nuclear factor kappa B p50 (NF-kB) p50 in the diabetic wound healing effects of SJHY formula. SJHY Formula was prepared by pharmaceutical preparation room of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine. Diabetic wound healing activity was evaluated by circular excision wound models. Wound healing activity was examined by macroscopic evaluation. Activin/follistatin expression regulation, protein expression of pSmad2 and NF-kB p50 in skin tissue of wounds were analyzed by Real Time PCR, Western blot, immunohistochemistry and hematoxylin and eosin (H&E) staining. Macroscopic evaluation analysis showed that wound healing of diabetic mice was delayed, and SJHY Formula accelerated wound healing time of diabetic mice. Real Time PCR analysis showed higher mRNA expression of activin/follistatin in diabetic delayed wound versus the wound in normal mice. Western Blot immunoassay analysis showed reduction of activin/follistatin proteins levels by SJHY Formula treatment 15 days after injury. Immunohistochemistry investigated the reduction of pSmad2 and NF-kB p50 nuclear staining in the epidermis of diabetic SJHY versus diabetic control mice on day 15 after wounding. H&E staining revealed that SJHY Formula

Multiple Factors Related to the Secretion of Glucagon-Like Peptide-1

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XingChun Wang

2015-01-01

Full Text Available The glucagon-like peptide-1 is secreted by intestinal L cells in response to nutrient ingestion. It regulates the secretion and sensitivity of insulin while suppressing glucagon secretion and decreasing postprandial glucose levels. It also improves beta-cell proliferation and prevents beta-cell apoptosis induced by cytotoxic agents. Additionally, glucagon-like peptide-1 delays gastric emptying and suppresses appetite. The impaired secretion of glucagon-like peptide-1 has negative influence on diabetes, hyperlipidemia, and insulin resistance related diseases. Thus, glucagon-like peptide-1-based therapies (glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are now well accepted in the management of type 2 diabetes. The levels of glucagon-like peptide-1 are influenced by multiple factors including a variety of nutrients. The component of a meal acts as potent stimulants of glucagon-like peptide-1 secretion. The levels of its secretion change with the intake of different nutrients. Some drugs also have influence on GLP-1 secretion. Bariatric surgery may improve metabolism through the action on GLP-1 levels. In recent years, there has been a great interest in developing effective methods to regulate glucagon-like peptide-1 secretion. This review summarizes the literature on glucagon-like peptide-1 and related factors affecting its levels.

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

International Nuclear Information System (INIS)

Ginsel, L.A.; Onderwater, J.J.M.; Daems, W.T.

1979-01-01

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

Regulation of the activins-follistatins-inhibins axis by energy status: Impact on reproductive function.

Science.gov (United States)

Perakakis, Nikolaos; Upadhyay, Jagriti; Ghaly, Wael; Chen, Joyce; Chrysafi, Pavlina; Anastasilakis, Athanasios D; Mantzoros, Christos S

2018-05-09

We have previously demonstrated that the adipose tissue derived hormone leptin controls reproductive function by regulating the hypothalamic-pituitary-gonadal axis in response to energy deficiency. Here, we evaluate the activins-follistatins-inhibins (AFI) axis during acute (short-term fasting in healthy people) and chronic energy deficiency (women with hypothalamic amenorrhea due to strenuous exercise [HA]) and investigate their relation to leptin and reproductive function in healthy subjects and subjects with HA. The AFI axis was investigated in: a) A double-blinded study in healthy subjects having three randomly assigned admissions, each time for four days: in the isocaloric fed state, complete fasting with placebo treatment, complete fasting with leptin replacement, b) A case-control study comparing women with HA vs healthy controls, c) An open-label interventional study investigating leptin treatment in women with HA over a period of up to three months, d) A randomized interventional trial investigating leptin treatment vs placebo in women with HA for nine months. The circulating levels of activin A, activin B, follistatin and follistatin-like 3 change robustly in response to acute and chronic energy deficiency. Leptin replacement in acute energy deprivation does not affect the levels of these hormones suggesting an independent regulation by these two hormonal pathways. In chronic energy deficiency, leptin replacement restores only activin B levels, which are in turn associated with an increase in the number of dominant follicles. We demonstrate for the first time that the AFI axis is affected both by acute and chronic energy deficiency. Partial restoration of a component of the axis, i.e. activin B only, through leptin replacement is associated with improved reproductive function in women with HA. Copyright © 2018. Published by Elsevier Inc.

FOXL2-induced follistatin attenuates activin A-stimulated cell proliferation in human granulosa cell tumors

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Cheng, Jung-Chien; Chang, Hsun-Ming; Qiu, Xin; Fang, Lanlan; Leung, Peter C.K., E-mail: peter.leung@ubc.ca

2014-01-10

Highlights: •Activin A stimulates cell proliferation in KGN human granulosa cell tumor-derived cell line. •Cyclin D2 mediates activin A-induced KGN cell proliferation. •FOXL2 induces follistatin expression in KGN cells. •FOXL2-induced follistatin attenuates activin A-stimulated KGN cell proliferation. -- Abstract: Human granulosa cell tumors (GCTs) are rare, and their etiology remains largely unknown. Recently, the FOXL2 402C > G (C134W) mutation was found to be specifically expressed in human adult-type GCTs; however, its function in the development of human GCTs is not fully understood. Activins are members of the transforming growth factor-beta superfamily, which has been shown to stimulate normal granulosa cell proliferation; however, little is known regarding the function of activins in human GCTs. In this study, we examined the effect of activin A on cell proliferation in the human GCT-derived cell line KGN. We show that activin A treatment stimulates KGN cell proliferation. Treatment with the activin type I receptor inhibitor SB431542 blocks activin A-stimulated cell proliferation. In addition, our results show that cyclin D2 is induced by treatment with activin A and is involved in activin A-stimulated cell proliferation. Moreover, the activation of Smad signaling is required for activin A-induced cyclin D2 expression. Finally, we show that the overexpression of the wild-type FOXL2 but not the C134W mutant FOXL2 induced follistatin production. Treatment with exogenous follistatin blocks activin A-stimulated cell proliferation, and the overexpression of wild-type FOXL2 attenuates activin A-stimulated cell proliferation. These results suggest that FOXL2 may act as a tumor suppressor in human adult-type GCTs by inducing follistatin expression, which subsequently inhibits activin-stimulated cell proliferation.

Transmembrane-sequence-dependent overexpression and secretion of glycoproteins in Saccharomyces cerevisiae.

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Schuster, M; Wasserbauer, E; Aversa, G; Jungbauer, A

2001-02-01

Protein expression using the secretory pathway in Saccharomyces cerevisiae can lead to high amounts of overexpressed and secreted proteins in culture supernatants in a short period of time. These post-translational modified expression products can be purified up to >90% in a single step. The overexpression and secretion of the transmembrane glycoprotein signaling lymphocytic activation molecule (SLAM) was studied. SLAM belongs to the immunoglobulin superfamily and its engagement results in T-cell expansion and INF-gamma production. The molecule is composed of an extracellular, a single-span transmembrane and a cytoplasmatic domain. The extracellular part may be relevant for stimulation studies in vitro since SLAM is a high-affinity self-ligand. Therefore several fragments of this region have been expressed as Flag-fusions in S. cerevisiae: a full-length fragment containing the transmembrane region and the autologous signal sequence, another without the transmembrane region, and two fragments without the autologous signal sequence with and without the transmembrane region. By molecular cloning, the different deletion mutants of the cDNA encoding the full-length construct have been inserted in a yeast episomal plasmid. Upstream of the cDNA, the alpha-leader sequence of a yeast mating pheromone has been cloned to direct the fusion proteins into the secretory protein maturation pathway. All four fragments were expressed but yield, location, and maturation were highly influenced by the transmembrane domain and the autologous signal sequence. Only the fragment without autologous signal sequence and transmembrane domain could be efficiently secreted. High-mannose glycosylation was analyzed by lectin mapping and digestion with specific glycosidases. After enzyme treatment, a single band product with the theoretical size could be detected and identified as SLAM by a specific monoclonal antibody. The fusion protein concentration in the supernatant was 30 microg/ml. The

Quantitative Secretome Analysis of Activated Jurkat Cells Using Click Chemistry-Based Enrichment of Secreted Glycoproteins.

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Witzke, Kathrin E; Rosowski, Kristin; Müller, Christian; Ahrens, Maike; Eisenacher, Martin; Megger, Dominik A; Knobloch, Jürgen; Koch, Andrea; Bracht, Thilo; Sitek, Barbara

2017-01-06

Quantitative secretome analyses are a high-performance tool for the discovery of physiological and pathophysiological changes in cellular processes. However, serum supplements in cell culture media limit secretome analyses, but serum depletion often leads to cell starvation and consequently biased results. To overcome these limiting factors, we investigated a model of T cell activation (Jurkat cells) and performed an approach for the selective enrichment of secreted proteins from conditioned medium utilizing metabolic marking of newly synthesized glycoproteins. Marked glycoproteins were labeled via bioorthogonal click chemistry and isolated by affinity purification. We assessed two labeling compounds conjugated with either biotin or desthiobiotin and the respective secretome fractions. 356 proteins were quantified using the biotin probe and 463 using desthiobiotin. 59 proteins were found differentially abundant (adjusted p-value ≤0.05, absolute fold change ≥1.5) between inactive and activated T cells using the biotin method and 86 using the desthiobiotin approach, with 31 mutual proteins cross-verified by independent experiments. Moreover, we analyzed the cellular proteome of the same model to demonstrate the benefit of secretome analyses and provide comprehensive data sets of both. 336 proteins (61.3%) were quantified exclusively in the secretome. Data are available via ProteomeXchange with identifier PXD004280.

Functional processing and secretion of Chikungunya virus E1 and E2 glycoproteins in insect cells

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Goldbach Rob W

2011-07-01

Full Text Available Abstract Background Chikungunya virus (CHIKV is a mosquito-borne, arthrogenic Alphavirus that causes large epidemics in Africa, South-East Asia and India. Recently, CHIKV has been transmitted to humans in Southern Europe by invading and now established Asian tiger mosquitoes. To study the processing of envelope proteins E1 and E2 and to develop a CHIKV subunit vaccine, C-terminally his-tagged E1 and E2 envelope glycoproteins were produced at high levels in insect cells with baculovirus vectors using their native signal peptides located in CHIKV 6K and E3, respectively. Results Expression in the presence of either tunicamycin or furin inhibitor showed that a substantial portion of recombinant intracellular E1 and precursor E3E2 was glycosylated, but that a smaller fraction of E3E2 was processed by furin into mature E3 and E2. Deletion of the C-terminal transmembrane domains of E1 and E2 enabled secretion of furin-cleaved, fully processed E1 and E2 subunits, which could then be efficiently purified from cell culture fluid via metal affinity chromatography. Confocal laser scanning microscopy on living baculovirus-infected Sf21 cells revealed that full-length E1 and E2 translocated to the plasma membrane, suggesting similar posttranslational processing of E1 and E2, as in a natural CHIKV infection. Baculovirus-directed expression of E1 displayed fusogenic activity as concluded from syncytia formation. CHIKV-E2 was able to induce neutralizing antibodies in rabbits. Conclusions Chikungunya virus glycoproteins could be functionally expressed at high levels in insect cells and are properly glycosylated and cleaved by furin. The ability of purified, secreted CHIKV-E2 to induce neutralizing antibodies in rabbits underscores the potential use of E2 in a subunit vaccine to prevent CHIKV infections.

Regulation of brown adipocyte metabolism by myostatin/follistatin signaling

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Rajan eSingh

2014-10-01

Full Text Available Obesity develops from perturbations of cellular bioenergetics, when energy uptake exceeds energy expenditure, and represents a major risk factor for the development of type 2 diabetes, dyslipidemia, cardiovascular disease, cancer, and other conditions. Brown adipose tissue (BAT has long been known to dissipate energy as heat and contribute to energy expenditure, but its presence and physiological role in adult human physiology has been questioned for years. Recent demonstrations of metabolically active brown fat depots in adult humans have revolutionized current therapeutic approaches for obesity-related diseases. The balance between white adipose tissue (WAT and BAT affects the systemic energy balance and is widely believed to be the key determinant in the development of obesity and related metabolic diseases. Members of the transforming growth factor-beta (TGF-β superfamily play an important role in regulating overall energy homeostasis by modulation of brown adipocyte characteristics. Inactivation of TGF-β/Smad3/myostatin (Mst signaling promotes browning of white adipocytes, increases mitochondrial biogenesis and protects mice from diet-induced obesity, suggesting the need for development of a novel class of TGF-β/Mst antagonists for the treatment of obesity and related metabolic diseases. We recently described an important role of follistatin (Fst, a soluble glycoprotein that is known to bind and antagonize Mst actions, during brown fat differentiation and the regulation of cellular metabolism. Here we highlight various investigations performed using different in vitro and in vivo models to support the contention that targeting TGF-β/Mst signaling enhances brown adipocyte functions and regulates energy balance, reducing insulin resistance and curbing the development of obesity and diabetes.

Appearance and cellular distribution of lectin-like receptors for alpha 1-acid glycoprotein in the developing rat testis

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1996-01-01

A histochemical avidin-biotin technique with three different alpha 1-acid glycoprotein glycoforms showed pronounced alterations in the cellular localization of two alpha 1-acid glycoprotein lectin-like receptors during cell differentiation in the developing rat testis. The binding of alpha 1-acid...

Regional localization of activin-βA, activin-βC, follistatin, proliferation, and apoptosis in adult and developing mouse prostate ducts.

Science.gov (United States)

Gold, Elspeth; Zellhuber-McMillan, Sylvia; Risbridger, Gail; Marino, Francesco Elia

2017-01-01

Activins and inhibins, members of the TGF-β superfamily, are growth and differentiation factors involved in the regulation of several biological processes, including reproduction, development, and fertility. Previous studies have shown that the activin-β A subunit plays a pivotal role in prostate development. Activin-A inhibits branching morphogenesis in the developing prostate, and its expression is associated with increased apoptosis in the adult prostate. Follistatin, a structurally unrelated protein to activins, is an antagonist of activin-A. A balance between endogenous activin-A and follistatin is required to maintain prostatic branching morphogenesis. Deregulation of this balance leads to branching inhibition or excessive branching and increased maturation of the stroma surrounding the differentiating epithelial ducts. Recent work identified another member of the TGF-β superfamily, the activin-β C subunit, as a novel antagonist of activin-A. Over-expression of activin-C (β C -β C ) alters prostate homeostasis, by interfering with the activin-A signaling. The current study characterized the spatiotemporal localization of activin-A, activin-C and follistatin in the adult and developing mouse prostate using immunohistochemical analysis. Results showed activin-C and follistatin are differentially expressed during prostate development and suggested that the antagonistic property of follistatin is secondary to the action of activin-C. In conclusion, the present study provides evidence to support a role of activin-C in prostate development and provides new insights in the spatiotemporal localization of activins and their antagonists during mouse prostate development. Copyright © 2017 Elsevier B.V. All rights reserved.

Water deprivation affects serotoninergic system and glycoprotein secretion in the sub-commissural organ of a desert rodent Meriones shawi.

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Elgot, Abdeljalil; Ahboucha, Samir; Bouyatas, My Mustapha; Fèvre-Montange, Michèlle; Gamrani, Halima

2009-11-27

Water deprivation is a stress that has been associated with activation of several endocrine systems, including circumventricular organs of the central nervous system. The sub-comissural organ (SCO), characterized by its glycoprotein secretion called Reissner's fiber has been suggested to play a role in the regulation of body water balance. Meriones shawi, a semi-desertic rodent characterized by its resistance to long periods of thirst was subjected to water deprivation for 1 and 3 months. Effect of water deprivation was evaluated immunohistochemically on 5-hydroxytryptamine (5-HT; serotonin) system and glycoprotein secretion of the SCO. Our findings demonstrate significant reduction of anti-Reissner's fiber immunoreactive materials within basal and apical parts of the SCO ependymocytes. These changes seem to be the consequence of reduced control by 5-HT fibers reaching the SCO as a concomitant and significant reduction of anti-5-HT immunoreactive fibers are also observed following water deprivation. 5-HT immunoreactive reduction is seen in several regions in the brain including the neurons of origin within the dorsal raphe nucleus and the projecting supra and sub-ependymal fibers reaching the classical ependyma of the third ventricle. The extent of Reissner's fiber and 5-HT immunoreactive changes significantly correlates with the severity of water restriction. We suggest that water deprivation causes changes of the classical ependyma and the specialized ependyma that differentiates into the SCO as well as other cirumventricular organs such as the subfornical organ and the organum vasculosum laminae terminalis known to control drinking behaviors.

Bidirectional regulation of bakuchiol, an estrogenic-like compound, on catecholamine secretion

International Nuclear Information System (INIS)

Mao, Haoping; Wang, Hong; Ma, Shangwei; Xu, Yantong; Zhang, Han; Wang, Yuefei; Niu, Zichang; Fan, Guanwei; Zhu, Yan; Gao, Xiu Mei

2014-01-01

Excess or deficiency of catecholamine (CA) secretion was related with several diseases. Recently, estrogen and phytoestrogens were reported to regulate the activity of CA system. Bakuchiol is a phytoestrogen isolated from the seeds of Psoralea corylifolia L. (Leguminosae) which has been used in Traditional Chinese medicine as a tonic or aphrodisiac. In the present study, bovine adrenal medullary cells were employed to investigate the effects and mechanisms of bakuchiol on the regulation of CA secretion. Further, its anti-depressant like and anti-stress effects were evaluated by using behavioral despair and chronic immobilization stress models. Our results indicated that bakuchiol showed bidirectional regulation on CA secretion. It stimulated basal CA secretion in a concentration dependent manner (p + (p + induced CA secretion was related with reduction of intracellular calcium rise. In vivo experiments, we found that bakuchiol significantly reduced immobilization time in behavioral despair mouse (p < 0.05 or 0.01), and plasma epinephrine (E) and norepinephrine (NE) levels in chronic immobilization stress (p < 0.05). Overall, these results present a bidirectional regulation of bakuchiol on CA secretion which indicated that bakuchiol may exert anti-stress and the potential anti-depressant-like effects. - Highlights: • Bakuchiol stimulated basal catecholamine secretion. • Bakuchiol inhibited various secretagogues induced catecholamine secretion. • Bakuchiol may have anti-stress and the potential anti-depression-like effects

EFFECTS OF CONCENTRIC AND ECCENTRIC MUSCLE ACTIONS ON SERUM MYOSTATIN AND FOLLISTATIN-LIKE RELATED GENE LEVELS

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Lemuel Taylor

2004-12-01

Full Text Available The present study determined the effects of concentric and eccentric muscle actions on the contents of serum myostatin and follistatin-like related gene (FLRG. Eight untrained males performed one exercise bout with each leg, separated by three weeks. One bout consisted of 7 sets of 10 repetitions of eccentric muscle actions of the knee extensors at 150% of the concentric 1-RM while the other bout consisted of 7 sets of 10 repetitions of concentric muscle actions at 75% 1-RM. The legs used and the bouts performed were randomized. Five days prior to each exercise bout, baseline measurements were taken for muscle strength. For both bouts, a venous blood sample was obtained immediately prior to exercise and again at 6, 24, and 48 hr post-exercise. Data were analyzed with 2 X 4 (bout x test ANOVA (p < 0.05. Increases in serum myostatin and FLRG occurred with each exercise bout and, excluding 48 hr post-exercise, were significantly correlated to one another (p < 0.05. After eccentric exercise, peak increases of 68% and 50% (p < 0.05 were observed for myostatin and FLRG, respectively. Similar increases of 54% and 44% (p < 0.05 were observed after concentric muscle actions. There was no significant difference in expression of myostatin or FLRG as a function of muscle action type. Our results suggest that a single bout of exercise with either eccentric or concentric muscle actions appear to elicit a similar increase in serum myostatin and FLRG. Therefore, the type of muscle action may not be as much a mitigating factor for increasing serum myostatin and FLRG rather than the muscle action per se.

Hantavirus Gn and Gc glycoproteins self-assemble into virus-like particles.

Science.gov (United States)

Acuña, Rodrigo; Cifuentes-Muñoz, Nicolás; Márquez, Chantal L; Bulling, Manuela; Klingström, Jonas; Mancini, Roberta; Lozach, Pierre-Yves; Tischler, Nicole D

2014-02-01

How hantaviruses assemble and exit infected cells remains largely unknown. Here, we show that the expression of Andes (ANDV) and Puumala (PUUV) hantavirus Gn and Gc envelope glycoproteins lead to their self-assembly into virus-like particles (VLPs) which were released to cell supernatants. The viral nucleoprotein was not required for particle formation. Further, a Gc endodomain deletion mutant did not abrogate VLP formation. The VLPs were pleomorphic, exposed protrusions and reacted with patient sera.

Follistatin: A Potential Anabolic Treatment for Re-Innervated Muscle

Science.gov (United States)

2017-09-01

Observations: ELISA , muscle histology, nerve histology, etc.are pending and no final conclusions can be made. 1. 3-month Protein: a. Muscle Weight: No...and virus needed for the study and also helped in Pilot Study- ELISA . He presented the following abstract in VCU School of Medicine Student Research...denervation groups (1-6): ▪ Follistatin ELISA – Run the assay, collect data, and prepare to present data ▪ Muscle Histology – Process tissue, image the

Bidirectional regulation of bakuchiol, an estrogenic-like compound, on catecholamine secretion

Energy Technology Data Exchange (ETDEWEB)

Mao, Haoping; Wang, Hong; Ma, Shangwei; Xu, Yantong; Zhang, Han; Wang, Yuefei [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China); Niu, Zichang [First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin (China); Fan, Guanwei; Zhu, Yan [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China); Gao, Xiu Mei, E-mail: gaoxiumei@tjutcm.edu.cn [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China)

2014-01-01

Excess or deficiency of catecholamine (CA) secretion was related with several diseases. Recently, estrogen and phytoestrogens were reported to regulate the activity of CA system. Bakuchiol is a phytoestrogen isolated from the seeds of Psoralea corylifolia L. (Leguminosae) which has been used in Traditional Chinese medicine as a tonic or aphrodisiac. In the present study, bovine adrenal medullary cells were employed to investigate the effects and mechanisms of bakuchiol on the regulation of CA secretion. Further, its anti-depressant like and anti-stress effects were evaluated by using behavioral despair and chronic immobilization stress models. Our results indicated that bakuchiol showed bidirectional regulation on CA secretion. It stimulated basal CA secretion in a concentration dependent manner (p < 0.01), while it reduced 300 μM acetylcholine (ACh) (p < 0.01), 100 μM veratridine (Ver) (p < 0.01) and 56 mM K{sup +} (p < 0.05) induced CA secretion, respectively. We also found that the stimulation of basal CA secretion by bakuchiol may act through estrogen-like effect and the JNK pathway in an extra-cellular calcium independent manner. Further, bakuchiol elevated tyrosine hydroxylase Ser40 and Ser31 phosphorylation (p < 0.01) through the PKA and ERK1/2 pathways, respectively. Bakuchiol inhibited ACh, Ver and 56 mM K{sup +} induced CA secretion was related with reduction of intracellular calcium rise. In vivo experiments, we found that bakuchiol significantly reduced immobilization time in behavioral despair mouse (p < 0.05 or 0.01), and plasma epinephrine (E) and norepinephrine (NE) levels in chronic immobilization stress (p < 0.05). Overall, these results present a bidirectional regulation of bakuchiol on CA secretion which indicated that bakuchiol may exert anti-stress and the potential anti-depressant-like effects. - Highlights: • Bakuchiol stimulated basal catecholamine secretion. • Bakuchiol inhibited various secretagogues induced catecholamine secretion

Evaluating the Effects of Cytomegalovirus Glycoprotein B on the Maturation and Function of Monocyte-derived dendritic cells

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Afsson shariat

2015-11-01

Full Text Available Background & Objectives: Interaction of cytomegalovirus glycoprotein B with toll-like receptors of dendritic cells leads to early signaling and innate immune responses. The aim of this study is to evaluate the effects of cytomegalovirus glycoprotein B on the maturation and function of monocyte-derived dendritic cells in treated groups in comparison with control groups. Materials & Methods: Blood samples were taken from 5 healthy volunteers. Following the generation of monocyte-derived dendritic cells on the fifth day of cell culture, half of the immature dendritic cells were treated with cytomegalovirus glycoprotein B, and the rest of them were induced to mature dendritic untreated cells and were used as the control group. The maturation and function of dendritic cells were evaluated in these two groups. Results: The gene expression level of toll-like receptor-4 significantly increased in the group treated with glycoprotein B (p < 0.05, whereas there were no significant differences in the expression rates of CD83, CD86, CD1a, and HLA-DR and the secretion of IL-23 from monocyte-derived dendritic cells between the treated groups and the controls. Conclusion: The increase in the gene expression of toll-like receptor-4 in monocyte-derived dendritic cells treated with cytomegalovirus glycoprotein B showed that cell contact is required to elicit cellular antiviral response and toll-like receptor activation. Thus, it is critical to recognize the viral and cellular determinants of the immune system in order to develop new therapeutic strategies against cytomegalovirus.

Follistatin, an Activin Antagonist, Ameliorates Renal Interstitial Fibrosis in a Rat Model of Unilateral Ureteral Obstruction

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Akito Maeshima

2014-01-01

Full Text Available Activin, a member of the TGF-β superfamily, regulates cell growth and differentiation in various cell types. Activin A acts as a negative regulator of renal development as well as tubular regeneration after renal injury. However, it remains unknown whether activin A is involved in renal fibrosis. To clarify this issue, we utilized a rat model of unilateral ureteral obstruction (UUO. The expression of activin A was significantly increased in the UUO kidneys compared to that in contralateral kidneys. Activin A was detected in glomerular mesangial cells and interstitial fibroblasts in normal kidneys. In UUO kidneys, activin A was abundantly expressed by interstitial α-SMA-positive myofibroblasts. Administration of recombinant follistatin, an activin antagonist, reduced the fibrotic area in the UUO kidneys. The number of proliferating cells in the interstitium, but not in the tubules, was significantly lower in the follistatin-treated kidneys. Expression of α-SMA, deposition of type I collagen and fibronectin, and CD68-positive macrophage infiltration were significantly suppressed in the follistatin-treated kidneys. These data suggest that activin A produced by interstitial fibroblasts acts as a potent profibrotic factor during renal fibrosis. Blockade of activin A action may be a novel approach for the prevention of renal fibrosis progression.

Intracellular localization of hydroxyproline-rich glycoprotein biosynthesis

International Nuclear Information System (INIS)

Robinson, D.G.; Andreae, M.; Glas, A.R.; Sauer, A.

1984-01-01

The structural proteins of plant cell walls are glycoproteins characterized by O-glucosidic linkages to hydroxyproline or serine. Proline, not hydroxyproline, is the translatable amino acid in hydroxyproline-rich glycoproteins (HRGP). Hydroxylation and arabinosylation of proline are sequential, post-translational events. Because of this, there is no a priori reason for expecting HRGP synthesis to follow the well-established route for secretory and plasma membrane (PM) glycoproteins, i.e., from endoplasmic reticulum (ER) via the Golgi apparatus (GA) to the PM. In this paper, two plausible alternatives for HRGO secretion are examined. Because a feature of the majority of dicotyledons is overlapping GA and PM regions in sucrose density gradients, the authors have used two monocotyledonous systems to determine the distribution of HRGP and enzyme activity

Neural regulation of glucagon-like peptide-1 secretion in pigs

DEFF Research Database (Denmark)

Hansen, Lene; Lampert, Sarah; Mineo, Hitoshi

2004-01-01

Glucagon-like peptide (GLP)-1 is secreted rapidly from the intestine postprandially. We therefore investigated its possible neural regulation. With the use of isolated perfused porcine ileum, GLP-1 secretion was measured in response to electrical stimulation of the mixed, perivascular nerve supply...

Circadian rhythm of glycoprotein secretion in the vas deferens of the moth, Spodoptera littoralis

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Gvakharia B

2002-09-01

Full Text Available Abstract Background Reproductive systems of male moths contain circadian clocks, which time the release of sperm bundles from the testis to the upper vas deferens (UVD and their subsequent transfer from the UVD to the seminal vesicles. Sperm bundles are released from the testis in the evening and are retained in the vas deferens lumen overnight before being transferred to the seminal vesicles. The biological significance of periodic sperm retention in the UVD lumen is not understood. In this study we asked whether there are circadian rhythms in the UVD that are correlated with sperm retention. Results We investigated the carbohydrate-rich material present in the UVD wall and lumen during the daily cycle of sperm release using the periodic acid-Shiff reaction (PAS. Males raised in 16:8 light-dark cycles (LD showed a clear rhythm in the levels of PAS-positive granules in the apical portion of the UVD epithelium. The peak of granule accumulation occurred in the middle of the night and coincided with the maximum presence of sperm bundles in the UVD lumen. These rhythms persisted in constant darkness (DD, indicating that they have circadian nature. They were abolished, however, in constant light (LL resulting in random patterns of PAS-positive material in the UVD wall. Gel-separation of the UVD homogenates from LD moths followed by detection of carbohydrates on blots revealed daily rhythms in the abundance of specific glycoproteins in the wall and lumen of the UVD. Conclusion Secretory activity of the vas deferens epithelium is regulated by the circadian clock. Daily rhythms in accumulation and secretion of several glycoproteins are co-ordinated with periodic retention of sperm in the vas deferens lumen.

Effect of physical training on liver expression of activin A and follistatin in a nonalcoholic fatty liver disease model in rats

International Nuclear Information System (INIS)

Silva, R.N.; Bueno, P.G.; Avó, L.R.S.; Nonaka, K.O.; Selistre-Araújo, H.S.; Leal, A.M.O.

2014-01-01

Nonalcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver and is associated with obesity and insulin resistance. Activin A is a member of the transforming growth factor beta (TGF)-β superfamily and inhibits hepatocyte growth. Follistatin antagonizes the biological actions of activin. Exercise is an important therapeutic strategy to reduce the metabolic effects of obesity. We evaluated the pattern of activin A and follistatin liver expression in obese rats subjected to swimming exercise. Control rats (C) and high-fat (HF) diet-fed rats were randomly assigned to a swimming training group (C-Swim and HF-Swim) or a sedentary group (C-Sed and HF-Sed). Activin βA subunit mRNA expression was significantly higher in HF-Swim than in HF-Sed rats. Follistatin mRNA expression was significantly lower in C-Swim and HF-Swim than in either C-Sed or HF-Sed animals. There was no evidence of steatosis or inflammation in C rats. In contrast, in HF animals the severity of steatosis ranged from grade 1 to grade 3. The extent of liver parenchyma damage was less in HF-Swim animals, with the severity of steatosis ranging from grade 0 to grade 1. These data showed that exercise may reduce the deleterious effects of a high-fat diet on the liver, suggesting that the local expression of activin-follistatin may be involved

Effect of physical training on liver expression of activin A and follistatin in a nonalcoholic fatty liver disease model in rats

Energy Technology Data Exchange (ETDEWEB)

Silva, R.N. [Departamento de Fisioterapia, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Bueno, P.G. [Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Avó, L.R.S. [Departamento de Medicina, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Nonaka, K.O.; Selistre-Araújo, H.S. [Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Leal, A.M.O. [Departamento de Medicina, Universidade Federal de São Carlos, São Carlos, SP (Brazil)

2014-07-25

Nonalcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver and is associated with obesity and insulin resistance. Activin A is a member of the transforming growth factor beta (TGF)-β superfamily and inhibits hepatocyte growth. Follistatin antagonizes the biological actions of activin. Exercise is an important therapeutic strategy to reduce the metabolic effects of obesity. We evaluated the pattern of activin A and follistatin liver expression in obese rats subjected to swimming exercise. Control rats (C) and high-fat (HF) diet-fed rats were randomly assigned to a swimming training group (C-Swim and HF-Swim) or a sedentary group (C-Sed and HF-Sed). Activin βA subunit mRNA expression was significantly higher in HF-Swim than in HF-Sed rats. Follistatin mRNA expression was significantly lower in C-Swim and HF-Swim than in either C-Sed or HF-Sed animals. There was no evidence of steatosis or inflammation in C rats. In contrast, in HF animals the severity of steatosis ranged from grade 1 to grade 3. The extent of liver parenchyma damage was less in HF-Swim animals, with the severity of steatosis ranging from grade 0 to grade 1. These data showed that exercise may reduce the deleterious effects of a high-fat diet on the liver, suggesting that the local expression of activin-follistatin may be involved.

Ammonia transport in the kidney by Rhesus glycoproteins

Science.gov (United States)

Verlander, Jill W.

2014-01-01

Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4+ with a new model in which specific and regulated transport of both NH3 and NH4+ across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport. PMID:24647713

EFFECTS OF SECRETABLE PLACENTAL FACTORS UPON SECRETION OF CYTOKINES BY THP-1 MONOCYTE-LIKE CELLS

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Ya. S. Onokhina

2013-01-01

Full Text Available Abstract. Мonocytes in feto-placental circulation are exposed to factors secreted by placental tissue. These factors influence monocyte functions in pregnancy. In present study, an in vitro model (monocyte-like THP-1 cells was used for assessing effects of soluble placental factors obtained from women with physiological pregnancies, or preeclampsia cases. The following effects of placental factors were revealed: increased secretion of VEGF by THP-1 cells along with decreased secretion of IL-6, IL-8 and MCP-1 under the influence of placental factors from the I. trimester of pregnancy in comparison with III. trimester. Secretion of IL-6 and MCP-1 by THP-1 cells was increased, and secretion of soluble TNFRII was decreased upon co-cultivation with soluble placental factors from the women with preeclampsia, as compared with placental products from physiological pregnancies.The work is supported by grants ГК № 02.740.11.0711 from Ministry of Education and Science, and НШ-3594.2010.7 grant from the President of Russian Federation.

Effect of physical training on liver expression of activin A and follistatin in a nonalcoholic fatty liver disease model in rats

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R.N. Silva

2014-09-01

Full Text Available Nonalcoholic fatty liver disease (NAFLD is characterized by fat accumulation in the liver and is associated with obesity and insulin resistance. Activin A is a member of the transforming growth factor beta (TGF-β superfamily and inhibits hepatocyte growth. Follistatin antagonizes the biological actions of activin. Exercise is an important therapeutic strategy to reduce the metabolic effects of obesity. We evaluated the pattern of activin A and follistatin liver expression in obese rats subjected to swimming exercise. Control rats (C and high-fat (HF diet-fed rats were randomly assigned to a swimming training group (C-Swim and HF-Swim or a sedentary group (C-Sed and HF-Sed. Activin βA subunit mRNA expression was significantly higher in HF-Swim than in HF-Sed rats. Follistatin mRNA expression was significantly lower in C-Swim and HF-Swim than in either C-Sed or HF-Sed animals. There was no evidence of steatosis or inflammation in C rats. In contrast, in HF animals the severity of steatosis ranged from grade 1 to grade 3. The extent of liver parenchyma damage was less in HF-Swim animals, with the severity of steatosis ranging from grade 0 to grade 1. These data showed that exercise may reduce the deleterious effects of a high-fat diet on the liver, suggesting that the local expression of activin-follistatin may be involved.

Concentration of activin A and follistatin in follicular fluid from human small antral follicles associated to gene expression of the corresponding granulosa cells

DEFF Research Database (Denmark)

Jeppesen, J V; Nielsen, M E; Kristensen, S G

2012-01-01

The present study correlated concentrations of activin A and follistatin in follicular fluid (FF) from human small antral follicles to FF concentrations of AMH, inhibin B, progesterone, and oestradiol and to the mRNA expression of FSH-receptor (FSHR), LH-receptor (LHR), AMH-receptor2 (AMHR2), CYP19...... activin A levels increased in follicles exceeding 10 mm in diameter. Levels of activin A and inhibin B showed a highly significant inverse association. Follistatin showed highly significant positive associations with AMH and inhibin B levels and with FSHR and AR gene expression in GC. This study revealed......a, and androgen-receptor (AR) in the corresponding granulosa cells (GC). FF from 144 follicles (3-12 mm in diameter) was included whereas mRNA expression profiles were established in GC from 66 of the 144 follicles. Levels of follistatin remained constant in relation to follicular diameter, whereas...

Structure of a trimeric variant of the Epstein-Barr virus glycoprotein B

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Backovic, Marija [Northwestern Univ., Evanston, IL (United States); Longnecker, Richard [Northwestern Univ., Chicago, IL (United States); Jardetzky, Theodore S [Northwestern Univ., Evanston, IL (United States)

2009-03-16

Epstein-Barr virus (EBV) is a herpesvirus that is associated with development of malignancies of lymphoid tissue. EBV infections are life-long and occur in >90% of the population. Herpesviruses enter host cells in a process that involves fusion of viral and cellular membranes. The fusion apparatus is comprised of envelope glycoprotein B (gB) and a heterodimeric complex made of glycoproteins H and L. Glycoprotein B is the most conserved envelope glycoprotein in human herpesviruses, and the structure of gB from Herpes simplex virus 1 (HSV-1) is available. Here, we report the crystal structure of the secreted EBV gB ectodomain, which forms 16-nm long spike-like trimers, structurally homologous to the postfusion trimers of the fusion protein G of vesicular stomatitis virus (VSV). Comparative structural analyses of EBV gB and VSV G, which has been solved in its pre and postfusion states, shed light on gB residues that may be involved in conformational changes and membrane fusion. Also, the EBV gB structure reveals that, despite the high sequence conservation of gB in herpesviruses, the relative orientations of individual domains, the surface charge distributions, and the structural details of EBV gB differ from the HSV-1 protein, indicating regions and residues that may have important roles in virus-specific entry.

Relationships among body composition, circulating concentrations of leptin and follistatin, and the onset of puberty and fertility in young female sheep.

Science.gov (United States)

Rosales Nieto, C A; Thompson, A N; Macleay, C A; Briegel, J R; Hedger, M P; Ferguson, M B; Martin, G B

2014-12-30

The onset of puberty depends on the attainment of critical body mass, so should also be affected by increases in the rate of accumulation of muscle and adipose tissue. Adipose tissue and reproduction are linked by leptin. For muscle, a link has not yet been identified, although one possibility is follistatin. We assessed the relationships among circulating concentrations of follistatin and leptin and the rates of growth and accumulation of muscle and fat during pubertal development in female sheep. We used 326 animals with known phenotypic values for live weight (LW), depths of eye muscle (EMD) and fat (FAT), and known breeding values at post-weaning age for body mass (PWT) and depths of eye muscle (PEMD) and fat (PFAT). Leptin concentration was positively correlated with values for EMD, PEMD, FAT, PFAT, LW and PWT (Preproductive rate (Preproductive rate (Preproductive performance. We conclude that leptin and follistatin are probably both involved in effects of accelerated accumulation of muscle and adipose tissues on the onset of puberty. Copyright © 2014 Elsevier B.V. All rights reserved.

Extracellular Glycoproteins in Embryogenic Culture of Pumpkin (Cucurbita pepo L.

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Hana Čipčić Paljetak

2011-01-01

Full Text Available The extracellular proteins in three distinctly induced embryogenic lines of pumpkin (Cucurbita pepo L. cultivated in four MS media modified regarding the nitrogen composition or auxin presence/absence have been analyzed. Extracellular glycoproteins containing α-D-mannose were specifically detected by the lectine concavalin A. During the cultivation of embryogenic tissue in the medium supplemented with reduced nitrogen, the embryos were mostly arrested at preglobular and globular developmental stages, which coincide with the absence of protein secretion. Secreted glycoproteins of 76, 68, 37 and 34 kDa were detected only if any of the three lines were cultivated in the medium that stimulates embryo development, irrespectively of the addition of 2,4-dichlorophenoxyacetic acid or tunicamycin. The glycoprotein of 64 kDa was detected in all lines cultivated in hormone-free MS medium with conventional nitrogen sources and it appears to be associated with embryo maturation. Tunicamycin treatment did not influence embryogenesis, although it specifically affected glycosylation of proteins in the investigated lines. Our results show that besides auxin, the source of nitrate is of great importance for proper protein glycosylation, excretion and developmental transition of pumpkin somatic embryos.

Protein and Site Specificity of Fucosylation in Liver-Secreted Glycoproteins

Czech Academy of Sciences Publication Activity Database

Pompach, Petr; Ashline, David J.; Brnáková, Z.; Benicky, J.; Sanda, M.; Goldman, R.

2014-01-01

Roč. 13, č. 12 (2014), s. 5561-5569 ISSN 1535-3893 R&D Projects: GA MŠk LH13051; GA ČR GAP206/12/0503 Grant - others:Charles Univ.(CZ) UNCE_204025/2012 Institutional support: RVO:61388971 Keywords : fucose * glycoproteins * liver * site specificity Subject RIV: CE - Biochemistry Impact factor: 4.245, year: 2014

Insulin-like growth factor-1 is a negative modulator of glucagon secretion

OpenAIRE

Mancuso, Elettra; Mannino, Gaia C.; Fatta, Concetta Di; Fuoco, Anastasia; Spiga, Rosangela; Andreozzi, Francesco; Sesti, Giorgio

2017-01-01

Glucagon secretion involves a combination of paracrine, autocrine, hormonal, and autonomic neural mechanisms. Type 2 diabetes often presents impaired glucagon suppression by insulin and glucose. Insulin-like growth factor-I (IGF-1) has elevated homology with insulin, and regulates pancreatic ?-cells insulin secretion. Insulin and IGF-1 receptors share considerable structure homology and function. We hypothesized the existence of a mechanism linking the inhibition of ?-cells glucagon secretion...

The hydroxyapatite-binding regions of a rat salivary glycoprotein.

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Embery, G; Green, D R

1989-09-01

The regions of a salivary sulphated glycoprotein which are involved in its attachment to hydroxyapatite (Biogel HTP) have been characterised. The sulphated glycoprotein, a 35S-labelled preparation from mixed palatal and buccal minor gland secretions of the rat was bound onto hydroxyapatite and the resultant glycoprotein-hydroxyapatite complex was sequentially digested with pronase E and alpha-L-fucosidase, a treatment which released 86.8% +/- 1.7% of the radioactivity of the initially bound glycoprotein. The fragments which remained attached to the hydroxyapatite after enzymic digestion were fractionated on Sephadex G-25 and analysed for carbohydrate and amino acid components. A range of amino acids were detected which could reflect both glycosylated and non-glycosylated-binding regions. Sialic acid, although considered to be involved in the attachment process was not detected in any of the fragments remaining after enzymic digestion, a finding which provides indirect evidence that the enzymically liberated products do not subsequently re-attach to the hydroxyapatite surface. The notable feature of the fractions with average Mr estimated at 1000 or less is the high proportion of N-acetylhexosamine and N-acetylgalactosamine. It is apparent that the hexosamine residues, which normally bear the ester sulphate moieties of sulphated glycoproteins, play an important role in the attachment of sulphated glycoproteins to hydroxyapatite.

Glycoprotein 130 receptor signaling mediates α-cell dysfunction in a rodent model of type 2 diabetes

DEFF Research Database (Denmark)

Chow, Samuel Z; Speck, Madeleine; Yoganathan, Piriya

2014-01-01

Dysregulated glucagon secretion accompanies islet inflammation in type 2 diabetes. We recently discovered that interleukin (IL)-6 stimulates glucagon secretion from human and rodent islets. IL-6 family cytokines require the glycoprotein 130 (gp130) receptor to signal. In this study, we elucidated...

The PsB glycoprotein complex is secreted as a preassembled precursor of the spore coat in Dictyostelium discoideum.

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Watson, N; McGuire, V; Alexander, S

1994-09-01

The PsB glycoprotein in Dictyostelium discoideum is one of a diverse group of developmentally regulated, prespore-cell-specific proteins, that contain a common O-linked oligosaccharide. This post-translational modification is dependent on the wild-type modB allele. The PsB protein exists as part of a multiprotein complex of six different proteins, which have different post-translational modifications and are held together by both covalent and non-covalent interactions (Watson et al. (1993). J. Biol. Chem. 268, 22634-22641). In this study we have used microscopic and biochemical analyses to examine the cellular localization and function of the PsB complex during development. We found that the PsB complex first accumulates in prespore vesicles in slug cells and is secreted later during culmination and becomes localized to both the extracellular matrix of the apical spore mass of mature fruiting bodies and to the inner layer of the spore coat. The PsB associated with the spore coat is covalently bound by disulfide bridges. The PsB protein always exists in a multiprotein complex, but the composition of the PsB complex changes during secretion and spore maturation. Some of the PsB complex proteins have been identified as spore coat proteins. These data demonstrate that some of the proteins that form the spore coat exist as a preassembled precursor complex. The PsB complex is secreted in a developmentally regulated manner during the process of spore differentiation, at which time proteins of the complex, as well as additional spore coat proteins, become covalently associated in at least two forms of extracellular matrix: the interspore matrix and the spore coat. These and other studies show that proteins with modB dependent O-linked oligosaccharides are involved in a wide variety of processes underlying morphogenesis in this organism. These developmental processes are the direct result of cellular mechanisms regulating protein targeting, assembly and secretion, and the

INFLUENCE OF ALPHA-1-ACID GLYCOPROTEIN UPON PRODUCTION OF CYTOKINES BY PERIPHERAL BLOOD MONONUCLEARS

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М. V. Osikov

2007-01-01

Full Text Available Abstract. Alpha-1-acid glycoprotein (orosomucoid is a multifunctional acute phase reactant belonging to the family of lipocalines from plasma alpha-2 globulin fraction. In present study, we investigated dosedependent effects of orosomucoid upon secretion of IL-1â, IL-2, IL-3, IL-4 by mononuclear cells from venous blood of healthy volunteers. Mononuclear cells were separated by means of gradient centrifugation, followed by incubation for 24 hours with 250, 500, or 1000 mcg of orosomucoid per ml RPMI-1640 medium (resp., low, medium and high dose. The levels of cytokine production were assayed by ELISA technique. Orosomucoid-induced secretion of IL-1â and IL-4 was increased, whereas IL-3 secretion was inhibited. IL-2 production was suppressed at low doses of orosomucoid, and stimulated at medium and high doses. The effect of alpha-1-acid glycoprotein upon production of IL-2, IL-3 and IL-4 was dose-dependent. Hence, these data indicate that orosomucoid is capable of modifying IL-1â, IL-2, IL-3, and IL-4 secretion by blood mononuclear cells.

The amino-terminus of the hepatitis C virus (HCV p7 viroporin and its cleavage from glycoprotein E2-p7 precursor determine specific infectivity and secretion levels of HCV particle types.

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Solène Denolly

2017-12-01

Full Text Available Viroporins are small transmembrane proteins with ion channel activities modulating properties of intracellular membranes that have diverse proviral functions. Hepatitis C virus (HCV encodes a viroporin, p7, acting during assembly, envelopment and secretion of viral particles (VP. HCV p7 is released from the viral polyprotein through cleavage at E2-p7 and p7-NS2 junctions by signal peptidase, but also exists as an E2p7 precursor, of poorly defined properties. Here, we found that ectopic p7 expression in HCVcc-infected cells reduced secretion of particle-associated E2 glycoproteins. Using biochemical assays, we show that p7 dose-dependently slows down the ER-to-Golgi traffic, leading to intracellular retention of E2, which suggested that timely E2p7 cleavage and p7 liberation are critical events to control E2 levels. By studying HCV mutants with accelerated E2p7 processing, we demonstrate that E2p7 cleavage controls E2 intracellular expression and secretion levels of nucleocapsid-free subviral particles and infectious virions. In addition, our imaging data reveal that, following p7 liberation, the amino-terminus of p7 is exposed towards the cytosol and coordinates the encounter between NS5A and NS2-based assembly sites loaded with E1E2 glycoproteins, which subsequently leads to nucleocapsid envelopment. We identify punctual mutants at p7 membrane interface that, by abrogating NS2/NS5A interaction, are defective for transmission of infectivity owing to decreased secretion of core and RNA and to increased secretion of non/partially-enveloped particles. Altogether, our results indicate that the retarded E2p7 precursor cleavage is essential to regulate the intracellular and secreted levels of E2 through p7-mediated modulation of the cell secretory pathway and to unmask critical novel assembly functions located at p7 amino-terminus.

'Leukodystrophy-like' phenotype in children with myelin oligodendrocyte glycoprotein antibody-associated disease.

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Hacohen, Yael; Rossor, Thomas; Mankad, Kshitij; Chong, Wk 'Kling'; Lux, Andrew; Wassmer, Evangeline; Lim, Ming; Barkhof, Frederik; Ciccarelli, Olga; Hemingway, Cheryl

2018-04-01

To review the demographics and clinical and paraclinical parameters of children with myelin oligodendrocyte glycoprotein (MOG) antibody-associated relapsing disease. In this UK-based, multicentre study, 31 children with MOG antibody-associated relapsing disease were studied retrospectively. Of the 31 children studied, 14 presented with acute disseminated encephalomyelitis (ADEM); they were younger (mean 4.1y) than the remainder (mean 8.5y) who presented with optic neuritis and/or transverse myelitis (p<0.001). Similarly, children who had an abnormal brain magnetic resonance imaging (MRI) at onset (n=20) were younger than patients with normal MRI at onset (p=0.001) or at follow-up (p<0.001). 'Leukodystrophy-like' MRI patterns of confluent largely symmetrical lesions was seen during the course of the disease in 7 out of 14 children with a diagnosis of ADEM, and was only seen in children younger than 7 years of age. Their disability after a 3-year follow-up was mild to moderate, and most patients continued to relapse, despite disease-modifying treatments. MOG antibody should be tested in children presenting with relapsing neurological disorders associated with confluent, bilateral white matter changes, and distinct enhancement pattern. Children with MOG antibody-associated disease present with age-related differences in phenotypes, with a severe leukoencephalopathy phenotype in the very young and normal intracranial MRI in the older children. This finding suggests a susceptibility of the very young and myelinating brain to MOG antibody-mediated mechanisms of damage. Myelin oligodendrocyte glycoprotein (MOG) antibody-associated demyelination manifest with an age-related phenotype. Children with MOG antibody and 'leukodystrophy-like' imaging patterns tend to have poor response to second-line immunotherapy. © 2017 Mac Keith Press.

The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

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Mingsheng Cai

Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

Alteration in follistatin gene expression detected in prenatally androgenized rats.

Science.gov (United States)

Salehi Jahromi, Marziyeh; Ramezani Tehrani, Fahimeh; Hill, Jennifer W; Noroozzadeh, Mahsa; Zarkesh, Maryam; Ghasemi, Asghar; Zadeh-Vakili, Azita

2017-06-01

Impaired ovarian follicle development, the hallmark of polycystic ovarian syndrome (PCOS), is believed to be due to the changes in expression of related genes such as follistatin (FST). Expression of FST gene and methylation level of its promoter in theca cells from adult female rats, prenatally exposed to androgen excess, during different phases of the estrus cycle was determined and compared with controls. Eight pregnant Wistar rats (experimental group) were treated by subcutaneous injection of 5 mg free testosterone on day 20 of pregnancy, while controls (n = 8) received 500 ml solvent. Based on observed vaginal smear, adult female offspring of mothers were divided into three groups. Levels of serum steroidogenic sexual hormones and gonadotropins, expression and promoter methylation of the FST gene were measured using ELISA, cyber-green real-time PCR and bisulfite sequence PCR (BSP), respectively. Compared to controls, the relative expression of FST gene in the treated group decreased overall by 0.85 fold; despite significant changes in different phases, but no significant differences in methylation of FST promoter. Our results reveal that manifestation of PCOS-like phenotype following prenatal exposure to excess androgen is associated with irregularity in expression of the FST gene during the estrus cycle.

Purification and partial characterization of low molecular weight vicilin-like glycoprotein from the seeds of Citrullus lanatus.

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Yadav, Sushila; Tomar, Anil Kumar; Jithesh, O; Khan, Meraj Alam; Yadav, R N; Srinivasan, A; Singh, Tej P; Yadav, Savita

2011-12-01

The watermelon (Citrullus lanatus) seeds are highly nutritive and contain large amount of proteins and many beneficial minerals such as magnesium, calcium, potassium, iron, phosphorous, zinc etc. In various parts of the world, C. lanatus seed extracts are used to cure cancer, cardiovascular diseases, hypertension, and blood pressure. C. lanatus seed extracts are also used as home remedy for edema and urinary tract problems. In this study, we isolated protein fraction of C. lanatus seeds using various protein separation methods. We successfully purified a low molecular weight vicilin-like glycoprotein using chromatographic methods followed by SDS-PAGE and MALDI-TOF/MS identification. This is the first report of purification of a vicilin like polypeptide from C. lanatus seeds. In next step, we extracted mRNA from immature seeds and reverse transcribed it using suitable forward and reverse primers for purified glycoprotein. The PCR product was analysed on 1% agarose gel and was subsequently sequenced by Dideoxy DNA sequencing method. An amino acid translation of the gene is in agreement with amino acid sequences of the identified peptides.

A phase 1/2a follistatin gene therapy trial for becker muscular dystrophy.

Science.gov (United States)

Mendell, Jerry R; Sahenk, Zarife; Malik, Vinod; Gomez, Ana M; Flanigan, Kevin M; Lowes, Linda P; Alfano, Lindsay N; Berry, Katherine; Meadows, Eric; Lewis, Sarah; Braun, Lyndsey; Shontz, Kim; Rouhana, Maria; Clark, Kelly Reed; Rosales, Xiomara Q; Al-Zaidy, Samiah; Govoni, Alessandra; Rodino-Klapac, Louise R; Hogan, Mark J; Kaspar, Brian K

2015-01-01

Becker muscular dystrophy (BMD) is a variant of dystrophin deficiency resulting from DMD gene mutations. Phenotype is variable with loss of ambulation in late teenage or late mid-life years. There is currently no treatment for this condition. In this BMD proof-of-principle clinical trial, a potent myostatin antagonist, follistatin (FS), was used to inhibit the myostatin pathway. Extensive preclinical studies, using adeno-associated virus (AAV) to deliver follistatin, demonstrated an increase in strength. For this trial, we used the alternatively spliced FS344 to avoid potential binding to off target sites. AAV1.CMV.FS344 was delivered to six BMD patients by direct bilateral intramuscular quadriceps injections. Cohort 1 included three subjects receiving 3 × 10(11) vg/kg/leg. The distance walked on the 6MWT was the primary outcome measure. Patients 01 and 02 improved 58 meters (m) and 125 m, respectively. Patient 03 showed no change. In Cohort 2, Patients 05 and 06 received 6 × 10(11) vg/kg/leg with improved 6MWT by 108 m and 29 m, whereas, Patient 04 showed no improvement. No adverse effects were encountered. Histological changes corroborated benefit showing reduced endomysial fibrosis, reduced central nucleation, more normal fiber size distribution with muscle hypertrophy, especially at high dose. The results are encouraging for treatment of dystrophin-deficient muscle diseases.

Up-Regulation of Follistatin-Like 1 By the Androgen Receptor and Melanoma Antigen-A11 in Prostate Cancer.

Science.gov (United States)

Su, Shifeng; Parris, Amanda B; Grossman, Gail; Mohler, James L; Wang, Zengjun; Wilson, Elizabeth M

2017-04-01

High affinity androgen binding to the androgen receptor (AR) activates genes required for male sex differentiation and promotes the development and progression of prostate cancer. Human AR transcriptional activity involves interactions with coregulatory proteins that include primate-specific melanoma antigen-A11 (MAGE-A11), a coactivator that increases AR transcriptional activity during prostate cancer progression to castration-resistant/recurrent prostate cancer (CRPC). Microarray analysis and quantitative RT-PCR were performed to identify androgen-regulated MAGE-A11-dependent genes in LAPC-4 prostate cancer cells after lentivirus shRNA knockdown of MAGE-A11. Chromatin immunoprecipitation was used to assess androgen-dependent AR recruitment, and immunocytochemistry to localize an androgen-dependent protein in prostate cancer cells and tissue and in the CWR22 human prostate cancer xenograft. Microarray analysis of androgen-treated LAPC-4 prostate cancer cells indicated follistatin-like 1 (FSTL1) is up-regulated by MAGE-A11. Androgen-dependent up-regulation of FSTL1 was inhibited in LAPC-4 cells by lentivirus shRNA knockdown of AR or MAGE-A11. Chromatin immunoprecipitation demonstrated AR recruitment to intron 10 of the FSTL1 gene that contains a classical consensus androgen response element. Increased levels of FSTL1 protein in LAPC-4 cells correlated with higher levels of MAGE-A11 relative to other prostate cancer cells. FSTL1 mRNA levels increased in CRPC and castration-recurrent CWR22 xenografts in association with predominantly nuclear FSTL1. Increased nuclear localization of FSTL1 in prostate cancer was suggested by predominantly cytoplasmic FSTL1 in benign prostate epithelial cells and predominantly nuclear FSTL1 in epithelial cells in CRPC tissue and the castration-recurrent CWR22 xenograft. AR expression studies showed nuclear colocalization of AR and endogenous FSTL1 in response to androgen. AR and MAGE-A11 cooperate in the up-regulation of FSTL1 to

Circulating irisin levels are lower in patients with either stable coronary artery disease (CAD) or myocardial infarction (MI) versus healthy controls, whereas follistatin and activin A levels are higher and can discriminate MI from CAD with similar to CK-MB accuracy.

Science.gov (United States)

Anastasilakis, Athanasios D; Koulaxis, Dimitrios; Kefala, Nikoleta; Polyzos, Stergios A; Upadhyay, Jagriti; Pagkalidou, Eirini; Economou, Fotios; Anastasilakis, Chrysostomos D; Mantzoros, Christos S

2017-08-01

Several myokines are produced by cardiac muscle. We investigated changes in myokine levels at the time of acute myocardial infarction (MI) and following reperfusion in relation to controls. Patients with MI (MI Group, n=31) treated with percutaneous coronary intervention (PCI) were compared to patients with stable coronary artery disease (CAD) subjected to scheduled PCI (CAD Group, n=40) and controls with symptoms mimicking CAD without stenosis in angiography (Control Group, n=43). The number and degree of stenosis were recorded. Irisin, follistatin, follistatin-like 3, activin A and B, ALT, AST, CK and CK-MB were measured at baseline and 6 or 24h after the intervention. MI and CAD patients had lower irisin than controls (p<0.001). MI patients had higher follistatin, activin A, CK, CK-MB and AST than CAD patients and controls (all p≤0.001). None of the myokines changed following reperfusion. Circulating irisin was associated with the degree of stenosis in all patients (p=0.05). Irisin was not inferior to CK-MB in predicting MI while folistatin and activin A could discriminate MI from CAD patients with similar to CK-MB accuracy. None of these myokines was altered following PCI in contrast to CK-MB. Irisin levels are lower in MI and CAD implying that their production may depend on myocadial blood supply. Follistatin and activin A are higher in MI than in CAD suggesting increased release due to myocardial necrosis. They can predict MI with accuracy similar to CK-MB and their role in the diagnosis of MI remains to be confirmed by prospective large clinical studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

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Aberle, Daniel; Oetter, Kay-Marcus; Meyers, Gregor

2015-01-01

Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

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Daniel Aberle

Full Text Available Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

Serum concentrations of insulin-like growth factor-1, members of the TGF-beta superfamily and follistatin do not reflect different stages of dynapenia and sarcopenia in elderly women.

Science.gov (United States)

Hofmann, Marlene; Halper, Barbara; Oesen, Stefan; Franzke, Bernhard; Stuparits, Petra; Tschan, Harald; Bachl, Norbert; Strasser, Eva-Maria; Quittan, Michael; Ploder, Martin; Wagner, Karl-Heinz; Wessner, Barbara

2015-04-01

There is a high need for blood-based biomarkers detecting age-related changes in muscular performance at an early stage. Therefore, we investigated whether serum levels of growth and differentiation factor-15 (GDF-15), activin A, myostatin, follistatin, and insulin-like growth factor-1 (IGF-1) would reflect age- and physical performance-related differences between young (22-28 years) and elderly (65-92 years) females. Isokinetic peak torque of knee extension (PTE) was measured in young females to obtain reference values for the discrimination of different stages of age-associated muscle weakness. Additionally, elderly women were screened for sarcopenia using the algorithm of the European Working Group on Sarcopenia in Older People (low muscle mass in addition to low PTE and/or low walking speed). IGF-1 levels were higher and GDF-15 levels were lower in young females in comparison to the elderly (p sarcopenia in elderly women. However, due to the associations of IGF-1 and GDF-15 with correlates of muscle mass and function, these parameters remain promising candidates in a potential set of blood-based biomarkers to diagnose sarcopenia and/or dynapenia. Copyright © 2015 Elsevier Inc. All rights reserved.

The glycoproteins of Marburg and Ebola virus and their potential roles in pathogenesis.

Science.gov (United States)

Feldmann, H; Volchkov, V E; Volchkova, V A; Klenk, H D

1999-01-01

Filoviruses cause systemic infections that can lead to severe hemorrhagic fever in human and non-human primates. The primary target of the virus appears to be the mononuclear phagocytic system. As the virus spreads through the organism, the spectrum of target cells increases to include endothelial cells, fibroblasts, hepatocytes, and many other cells. There is evidence that the filovirus glycoprotein plays an important role in cell tropism, spread of infection, and pathogenicity. Biosynthesis of the glycoprotein forming the spikes on the virion surface involves cleavage by the host cell protease furin into two disulfide linked subunits GP1 and GP2. GP1 is also shed in soluble form from infected cells. Different strains of Ebola virus show variations in the cleavability of the glycoprotein, that may account for differences in pathogenicity, as has been observed with influenza viruses and paramyxoviruses. Expression of the spike glycoprotein of Ebola virus, but not of Marburg virus, requires transcriptional editing. Unedited GP mRNA yields the nonstructural glycoprotein sGP, which is secreted extensively from infected cells. Whether the soluble glycoproteins GP1 and sGP interfere with the humoral immune response and other defense mechanisms remains to be determined.

Development of glycoprotein capture-based label-free method for the high-throughput screening of differential glycoproteins in hepatocellular carcinoma.

Science.gov (United States)

Chen, Rui; Tan, Yexiong; Wang, Min; Wang, Fangjun; Yao, Zhenzhen; Dong, Liwei; Ye, Mingliang; Wang, Hongyang; Zou, Hanfa

2011-07-01

A robust, reproducible, and high throughput method was developed for the relative quantitative analysis of glycoprotein abundances in human serum. Instead of quantifying glycoproteins by glycopeptides in conventional quantitative glycoproteomics, glycoproteins were quantified by nonglycosylated peptides derived from the glycoprotein digest, which consists of the capture of glycoproteins in serum samples and the release of nonglycopeptides by trypsin digestion of captured glycoproteins followed by two-dimensional liquid chromatography-tandem MS analysis of released peptides. Protein quantification was achieved by comparing the spectrum counts of identified nonglycosylated peptides of glycoproteins between different samples. This method was demonstrated to have almost the same specificity and sensitivity in glycoproteins quantification as capture at glycopeptides level. The differential abundance of proteins present at as low as nanogram per milliliter levels was quantified with high confidence. The established method was applied to the analysis of human serum samples from healthy people and patients with hepatocellular carcinoma (HCC) to screen differential glycoproteins in HCC. Thirty eight glycoproteins were found with substantial concentration changes between normal and HCC serum samples, including α-fetoprotein, the only clinically used marker for HCC diagnosis. The abundance changes of three glycoproteins, i.e. galectin-3 binding protein, insulin-like growth factor binding protein 3, and thrombospondin 1, which were associated with the development of HCC, were further confirmed by enzyme-linked immunosorbent assay. In conclusion, the developed method was an effective approach to quantitatively analyze glycoproteins in human serum and could be further applied in the biomarker discovery for HCC and other cancers.

Glycoprotein component of plant cell walls

International Nuclear Information System (INIS)

Cooper, J.B.; Chen, J.A.; Varner, J.E.

1984-01-01

The primary wall surrounding most dicotyledonous plant cells contains a hydroxyproline-rich glycoprotein (HRGP) component named extensin. A small group of glycopeptides solubilized from isolated cell walls by proteolysis contained a repeated pentapeptide glycosylated by tri- and tetraarabinosides linked to hydroxyproline and, by galactose, linked to serine. Recently, two complementary approaches to this problem have provided results which greatly increase the understanding of wall extensin. In this paper the authors describe what is known about the structure of soluble extensin secreted into the walls of the carrot root cells

Convergent evolution of pregnancy-specific glycoproteins in human and horse.

Science.gov (United States)

Aleksic, Denis; Blaschke, Lisa; Mißbach, Sophie; Hänske, Jana; Weiß, Wiebke; Handler, Johannes; Zimmermann, Wolfgang; Cabrera-Sharp, Victoria; Read, Jordan E; de Mestre, Amanda M; O'Riordan, Ronan; Moore, Tom; Kammerer, Robert

2016-09-01

Pregnancy-specific glycoproteins (PSGs) are members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family that are secreted by trophoblast cells. PSGs may modulate immune, angiogenic and platelet responses during pregnancy. Until now, PSGs are only found in species that have a highly invasive (hemochorial) placentation including humans, mice and rats. Surprisingly, analyzing the CEACAM gene family of the horse, which has a non-invasive epitheliochorial placenta, with the exception of the transient endometrial cups, we identified equine CEACAM family members that seem to be related to PSGs of rodents and primates. We identified seven genes that encode secreted PSG-like CEACAMs Phylogenetic analyses indicate that they evolved independently from an equine CEACAM1-like ancestor rather than from a common PSG-like ancestor with rodents and primates. Significantly, expression of PSG-like genes (CEACAM44, CEACAM48, CEACAM49 and CEACAM55) was found in non-invasive as well as invasive trophoblast cells such as purified chorionic girdle cells and endometrial cup cells. Chorionic girdle cells are highly invasive trophoblast cells that invade the endometrium of the mare where they form endometrial cups and are in close contact with maternal immune cells. Therefore, the microenvironment of invasive equine trophoblast cells has striking similarities to the microenvironment of trophoblast cells in hemochorial placentas, suggesting that equine PSG-like CEACAMs and rodent and primate PSGs have undergone convergent evolution. This is supported by our finding that equine PSG-like CEACAM49 exhibits similar activity to certain rodent and human PSGs in a functional assay of platelet-fibrinogen binding. Our results have implications for understanding the evolution of PSGs and their functions in maternal-fetal interactions. © 2016 Society for Reproduction and Fertility.

Uterine-embryonic interaction in pit : activin, follistatin, and activin receptor II in uterus and embryo during early gestation

NARCIS (Netherlands)

Pavert, van de S.A.; Boerjan, M.L.; Stroband, H.W.J.; Taverne, M.A.M.; Hurk, van der R.

2001-01-01

The mRNA expression patterns of activin A and follistatin in the uterus and embryo, the mRNA expression of the activin receptor II in the embryo, and the localization in the uterus of the immunoreactive activin A and the receptor II proteins in the uterus were examined at gestation days 7-12 after

Humanizing recombinant glycoproteins from Chinese hamster ovary cells

DEFF Research Database (Denmark)

Hansen, Anders Holmgaard; Amann, Thomas; Kol, Stefan

With new tools for gene-editing like zinc-fingers, TALENS and CRISPR, it is now feasible totailor-make the N-Glycoforms for therapeutic glycoproteins that have previously been almost impossible. We here demonstrate a case of humanizing a recombinant human glycoprotein that in Wild type (WT) Chinese...

p53- and ERK7-dependent ribosome surveillance response regulates Drosophila insulin-like peptide secretion.

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Kiran Hasygar

2014-11-01

Full Text Available Insulin-like signalling is a conserved mechanism that coordinates animal growth and metabolism with nutrient status. In Drosophila, insulin-producing median neurosecretory cells (IPCs regulate larval growth by secreting insulin-like peptides (dILPs in a diet-dependent manner. Previous studies have shown that nutrition affects dILP secretion through humoral signals derived from the fat body. Here we uncover a novel mechanism that operates cell autonomously in the IPCs to regulate dILP secretion. We observed that impairment of ribosome biogenesis specifically in the IPCs strongly inhibits dILP secretion, which consequently leads to reduced body size and a delay in larval development. This response is dependent on p53, a known surveillance factor for ribosome biogenesis. A downstream effector of this growth inhibitory response is an atypical MAP kinase ERK7 (ERK8/MAPK15, which is upregulated in the IPCs following impaired ribosome biogenesis as well as starvation. We show that ERK7 is sufficient and essential to inhibit dILP secretion upon impaired ribosome biogenesis, and it acts epistatically to p53. Moreover, we provide evidence that p53 and ERK7 contribute to the inhibition of dILP secretion upon starvation. Thus, we conclude that a cell autonomous ribosome surveillance response, which leads to upregulation of ERK7, inhibits dILP secretion to impede tissue growth under limiting dietary conditions.

Cell wall O-glycoproteins and N-glycoproteins: biosynthesis and some functional aspects.

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Eric eNguema-Ona

2014-10-01

Full Text Available Cell wall O-glycoproteins and N-glycoproteins are two types of glycomolecules whose glycans are structurally complex. They are both assembled and modified within the endomembrane system, i.e., the endoplasmic reticulum (ER and the Golgi apparatus, before their transport to their final locations within or outside the cell. In contrast to extensin, the O-glycan chains of arabinogalactan proteins are highly heterogeneous consisting mostly of (i a short oligo-arabinoside chain of three to four residues, and (ii a larger -1,3-linked galactan backbone with -1,6-linked side chains containing galactose, arabinose and, often, fucose, rhamnose or glucuronic acid. The fine structure of arabinogalactan chains varies between, and within plant species, and is important for the functional activities of the glycoproteins. With regards to N-glycans, ER-synthesizing events are highly conserved in all eukaryotes studied so far since they are essential for efficient protein folding. In contrast, evolutionary adaptation of N-glycan processing in the Golgi apparatus has given rise to a variety of organism-specific complex structures. Therefore, plant complex-type N-glycans contain specific glyco-epitopes such as core 1,2-xylose, core 1,3-fucose residues and Lewisa substitutions on the terminal position of the antenna. Like O-glycans, N-glycans of proteins are essential for their stability and function. Mutants affected in the glycan metabolic pathways have provided valuable information on the role of N-/O-glycoproteins in the control of growth, morphogenesis and adaptation to biotic and abiotic stresses. With regards to O-glycoproteins only extensin and arabinogalactan proteins are considered herein. The biosynthesis of these glycoproteins and functional aspects are presented and discussed in this review.

Regenerative hair waves in aging mice and extra-follicular modulators follistatin, dkk1, and sfrp4.

Science.gov (United States)

Chen, Chih-Chiang; Murray, Philip J; Jiang, Ting Xin; Plikus, Maksim V; Chang, Yun-Ting; Lee, Oscar K; Widelitz, Randall B; Chuong, Cheng-Ming

2014-08-01

Hair cycling is modulated by factors both intrinsic and extrinsic to hair follicles. Cycling defects lead to conditions such as aging-associated alopecia. Recently, we demonstrated that mouse skin exhibits regenerative hair waves, reflecting a coordinated regenerative behavior in follicle populations. Here, we use this model to explore the regenerative behavior of aging mouse skin. Old mice (>18 months) tracked over several months show that with progressing age, hair waves slow down, wave propagation becomes restricted, and hair cycle domains fragment into smaller domains. Transplanting aged donor mouse skin to a young host can restore donor cycling within a 3 mm range of the interface, suggesting that changes are due to extracellular factors. Therefore, hair stem cells in aged skin can be reactivated. Molecular studies show that extra-follicular modulators Bmp2, Dkk1, and Sfrp4 increase in early anagen. Further, we identify follistatin as an extra-follicular modulator, which is highly expressed in late telogen and early anagen. Indeed, follistatin induces hair wave propagation and its level decreases in aging mice. We present an excitable medium model to simulate the cycling behavior in aging mice and illustrate how the interorgan macroenvironment can regulate the aging process by integrating both "activator" and "inhibitor" signals.

Combined contributions of over-secreted glucagon-like peptide 1 and suppressed insulin secretion to hyperglycemia induced by gatifloxacin in rats

Energy Technology Data Exchange (ETDEWEB)

Yu, Yunli, E-mail: chrisyu1255@yahoo.com.cn [Department of Pharmaceutics, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Wang, Xinting, E-mail: wxinting1986@yahoo.com.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Can, E-mail: ltsan@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Yao, Dan, E-mail: erinyao@126.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Shanghai Institute of Materia Medica, Shanghai 201203 (China); Hu, Mengyue, E-mail: juliahmy@126.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Li, Jia, E-mail: ljbzd@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Hu, Nan, E-mail: hn_324@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Li, E-mail: liulee@cpu.edu.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Xiaodong, E-mail: xdliu@cpu.edu.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China)

2013-02-01

Accumulating evidences have showed that gatifloxacin causes dysglycemia in both diabetic and non-diabetic patients. Our preliminary study demonstrated that gatifloxacin stimulated glucagon-like peptide 1 (GLP-1) secretion from intestinal cells. The aim of the study was to investigate the association between gatifloxacin-stimulated GLP-1 release and dysglycemia in both normal and streptozotocin-induced diabetic rats and explore the possible mechanisms. Oral administration of gatifloxacin (100 mg/kg/day and 200 mg/kg/day) for 3 and 12 days led to marked elevation of GLP-1 levels, accompanied by significant decrease in insulin levels and increase in plasma glucose. Similar results were found in normal rats treated with 3-day gatifloxacin. Gatifloxacin-stimulated GLP-1 release was further confirmed in NCI-H716 cells, which was abolished by diazoxide, a K{sub ATP} channel opener. QT-PCR analysis showed that gatifloxacin also upregulated expression of proglucagon and prohormone convertase 3 mRNA. To clarify the contradiction on elevated GLP-1 without insulinotropic effect, effects of GLP-1 and gatifloxacin on insulin release were investigated using INS-1 cells. We found that short exposure (2 h) to GLP-1 stimulated insulin secretion and biosynthesis, whereas long exposure (24 h and 48 h) to high level of GLP-1 inhibited insulin secretion and biosynthesis. Moreover, we also confirmed gatifloxacin acutely stimulated insulin secretion while chronically inhibited insulin biosynthesis. All the results gave an inference that gatifloxacin stimulated over-secretion of GLP-1, in turn, high levels of GLP-1 and gatifloxacin synergistically impaired insulin release, worsening hyperglycemia. -- Highlights: ► Gatifloxacin induced hyperglycemia both in diabetic rats and normal rats. ► Gatifloxacin enhanced GLP-1 secretion but inhibited insulin secretion in rats. ► Long-term exposure to high GLP-1 inhibited insulin secretion and biosynthesis. ► GLP-1 over-secretion may be

Combined contributions of over-secreted glucagon-like peptide 1 and suppressed insulin secretion to hyperglycemia induced by gatifloxacin in rats

International Nuclear Information System (INIS)

Yu, Yunli; Wang, Xinting; Liu, Can; Yao, Dan; Hu, Mengyue; Li, Jia; Hu, Nan; Liu, Li; Liu, Xiaodong

2013-01-01

Accumulating evidences have showed that gatifloxacin causes dysglycemia in both diabetic and non-diabetic patients. Our preliminary study demonstrated that gatifloxacin stimulated glucagon-like peptide 1 (GLP-1) secretion from intestinal cells. The aim of the study was to investigate the association between gatifloxacin-stimulated GLP-1 release and dysglycemia in both normal and streptozotocin-induced diabetic rats and explore the possible mechanisms. Oral administration of gatifloxacin (100 mg/kg/day and 200 mg/kg/day) for 3 and 12 days led to marked elevation of GLP-1 levels, accompanied by significant decrease in insulin levels and increase in plasma glucose. Similar results were found in normal rats treated with 3-day gatifloxacin. Gatifloxacin-stimulated GLP-1 release was further confirmed in NCI-H716 cells, which was abolished by diazoxide, a K ATP channel opener. QT-PCR analysis showed that gatifloxacin also upregulated expression of proglucagon and prohormone convertase 3 mRNA. To clarify the contradiction on elevated GLP-1 without insulinotropic effect, effects of GLP-1 and gatifloxacin on insulin release were investigated using INS-1 cells. We found that short exposure (2 h) to GLP-1 stimulated insulin secretion and biosynthesis, whereas long exposure (24 h and 48 h) to high level of GLP-1 inhibited insulin secretion and biosynthesis. Moreover, we also confirmed gatifloxacin acutely stimulated insulin secretion while chronically inhibited insulin biosynthesis. All the results gave an inference that gatifloxacin stimulated over-secretion of GLP-1, in turn, high levels of GLP-1 and gatifloxacin synergistically impaired insulin release, worsening hyperglycemia. -- Highlights: ► Gatifloxacin induced hyperglycemia both in diabetic rats and normal rats. ► Gatifloxacin enhanced GLP-1 secretion but inhibited insulin secretion in rats. ► Long-term exposure to high GLP-1 inhibited insulin secretion and biosynthesis. ► GLP-1 over-secretion may be involved in

Use of radioactive glucosamine in the perfused rat liver to prepare α1-acid glycoprotein (orosomucoid) with 3H- or 14C-labelled sialic acid and N-acetylglucosamine residues

International Nuclear Information System (INIS)

Aronson, N.N. Jr.

1982-01-01

A method was developed whereby [1- 14 C]glucosamine was used in a perfused rat liver system to prepare over 2 mg of α 1 -acid glycoprotein with highly radioactive sialic acid and glucosamine residues. The liver secreted radioactive α 1 -acid glycoprotein over a 4-6 h period, and this glycoprotein was purified from the perfusate by chromatography on DEAE-cellulose at pH3.6. The sialic acid on the isolated glycoprotein had a specific radioactivity of 3.1 Ci/mol, whereas the glucosamine-specific radioactivity was 4.3 Ci/mole. The latter amino-sugar residues on the isolated protein were only 13-fold less radioactive than the initially added [1- 14 C]glucosamine. Orosomucoid with a specific radioactivity of 31.3 μCi/mg of protein was obtainable by using [6- 3 H]glucosamine. Many other radioactive glycoproteins were found to be secreted into the perfusate by the liver. Thus this experimental system should prove useful for obtaining other serum glycoproteins with highly radioactive sugar moieties. (author)

Metabolic profiling of follistatin overexpression: a novel therapeutic strategy for metabolic diseases

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Singh R

2018-03-01

Full Text Available Rajan Singh,1,2 Shehla Pervin,1,2 Se-Jin Lee,3,4 Alan Kuo,5 Victor Grijalva,6 John David,7 Laurent Vergnes,8 Srinivasa T Reddy1,6 1Department of Obstetrics and Gynecology, UCLA School of Medicine, Los Angeles, CA, USA; 2Division of Endocrinology and Metabolism, Charles R. Drew University of Medicine and Science, Los Angeles, CA, USA; 3The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; 4Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, CT, USA; 5Department of Biology, California State University Dominguez Hills, CA, USA; 6Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA, USA; 7Department of Comparative Medicine, Pfizer Inc, San Diego, CA, USA; 8Department of Human Genetics, UCLA School of Medicine, Los Angeles, CA, USA Background: Follistatin (Fst promotes brown adipocyte characteristics in adipose tissues.Methods: Abdominal fat volume (CT scan, glucose clearance (GTT test, and metabolomics analysis (mass spectrometry of adipose tissues from Fst transgenic (Fst-Tg and wild type (WT control mice were analyzed. Oxygen consumption (Seahorse Analyzer and lipidomics (gas chromatography was analyzed in 3T3-L1 cells.Results: Fst-Tg mice show significant decrease in abdominal fat content, increased glucose clearance, improved plasma lipid profiles and significant changes in several conventional metabolites compared to the WT mice. Furthermore, overexpression of Fst in 3T3-L1 cells resulted in up regulation of key brown/beige markers and changes in lipidomics profiles. Conclusion: Fst modulates key factors involved in promoting metabolic syndrome and could be used for therapeutic intervention. Keywords: follistatin, transgenic, adipocyte, fibroblast growth factor 21, AdipoQ

GnRH-induced Ca2+ signaling patterns and gonadotropin secretion in pituitary gonadotrophs. Functional adaptations to both ordinary and extraordinary physiological demands

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María Luisa eDurán-Pastén

2013-09-01

Full Text Available Pituitary gonadotrophs are a small fraction of the anterior pituitary population, yet they synthesize gonadotropins: luteinizing (LH and follicle stimulating (FSH, essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca2+ rises produced do not influence secretion, which is mainly driven by Gonadotropin Releasing Hormone (GnRH, a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G protein coupled receptors triggers Ca2+ mobilization from InsP3-sensitive intracellular pools, generating the global Ca2+ elevations necessary for secretion. Ca2+ signaling responses to increasing [GnRH] vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory, to biphasic (spike-oscillatory or spike-plateau. This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca2+ signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases and Ca2+ signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary

Global analysis of glycoproteins identifies markers of endotoxin tolerant monocytes and GPR84 as a modulator of TNFα expression.

Science.gov (United States)

Müller, Mario M; Lehmann, Roland; Klassert, Tilman E; Reifenstein, Stella; Conrad, Theresia; Moore, Christoph; Kuhn, Anna; Behnert, Andrea; Guthke, Reinhard; Driesch, Dominik; Slevogt, Hortense

2017-04-12

Exposure of human monocytes to lipopolysaccharide (LPS) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance. In this study, we investigated the LPS-induced global glycoprotein expression changes of tolerant human monocytes and THP-1 cells to identify markers and glycoprotein targets capable to modulate the immunosuppressive state. Using hydrazide chemistry and LC-MS/MS analysis, we analyzed glycoprotein expression changes during a 48 h LPS time course. The cellular snapshots at different time points identified 1491 glycoproteins expressed by monocytes and THP-1 cells. Label-free quantitative analysis revealed transient or long-lasting LPS-induced expression changes of secreted or membrane-anchored glycoproteins derived from intracellular membrane coated organelles or from the plasma membrane. Monocytes and THP-1 cells demonstrated marked differences in glycoproteins differentially expressed in the tolerant state. Among the shared differentially expressed glycoproteins G protein-coupled receptor 84 (GPR84) was identified as being capable of modulating pro-inflammatory TNFα mRNA expression in the tolerant cell state when activated with its ligand Decanoic acid.

Glutamine-Elicited Secretion of Glucagon-Like Peptide 1 Is Governed by an Activated Glutamate Dehydrogenase.

Science.gov (United States)

Andersson, Lotta E; Shcherbina, Liliya; Al-Majdoub, Mahmoud; Vishnu, Neelanjan; Arroyo, Claudia Balderas; Aste Carrara, Jonathan; Wollheim, Claes B; Fex, Malin; Mulder, Hindrik; Wierup, Nils; Spégel, Peter

2018-03-01

Glucagon-like peptide 1 (GLP-1), secreted from intestinal L cells, glucose dependently stimulates insulin secretion from β-cells. This glucose dependence prevents hypoglycemia, rendering GLP-1 analogs a useful and safe treatment modality in type 2 diabetes. Although the amino acid glutamine is a potent elicitor of GLP-1 secretion, the responsible mechanism remains unclear. We investigated how GLP-1 secretion is metabolically coupled in L cells (GLUTag) and in vivo in mice using the insulin-secreting cell line INS-1 832/13 as reference. A membrane-permeable glutamate analog (dimethylglutamate [DMG]), acting downstream of electrogenic transporters, elicited similar alterations in metabolism as glutamine in both cell lines. Both DMG and glutamine alone elicited GLP-1 secretion in GLUTag cells and in vivo, whereas activation of glutamate dehydrogenase (GDH) was required to stimulate insulin secretion from INS-1 832/13 cells. Pharmacological inhibition in vivo of GDH blocked secretion of GLP-1 in response to DMG. In conclusion, our results suggest that nonelectrogenic nutrient uptake and metabolism play an important role in L cell stimulus-secretion coupling. Metabolism of glutamine and related analogs by GDH in the L cell may explain why GLP-1 secretion, but not that of insulin, is activated by these secretagogues in vivo. © 2017 by the American Diabetes Association.

A glycoprotein with anti-inflammatory properties secreted by an Aspergillus nidulans modified strain

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J. C. F. Queiroz

2007-01-01

Full Text Available Total RNA from lipopolysaccharide (LPS-stimulated rat macrophages used to treat protoplasts from an Aspergillus nidulans strain originated the RT2 regenerated strain, whose culture supernatant showed anti-inflammatory activity in Wistar rats. The protein fraction presenting such anti-inflammatory activity was purified and biochemically identified. The screening of the fraction responsible for such anti-inflammatory property was performed by evaluating the inhibition of carrageenan-induced paw edema in male Swiss mice. Biochemical analyses of the anti-inflammatory protein used chromatography, carbohydrates quantification of the protein sample, amino acids content analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Total sugar quantification revealed 32% glycosylation of the protein fraction. Amino acid analysis of such fraction showed a peculiar pattern presenting 29% valine. SDS-PAGE revealed that the protein sample is pure and its molecular weight is about 40kDa. Intravenous injection of the isolated substance into mice significantly inhibited carrageenan-induced paw edema. The isolated glycoprotein decreased carrageenan-induced paw edema in a prostaglandin-dependent phase, suggesting an inhibitory effect of the isolated glycoprotein on prostaglandin synthesis.

Glucagon-like peptide 2 stimulates glucagon secretion, enhances lipid absorption, and inhibits gastric acid secretion in humans

DEFF Research Database (Denmark)

Meier, Juris J; Nauck, Michael A; Pott, Andrea

2006-01-01

or placebo during the ingestion of a solid test meal. Gastric emptying was determined using a 13C-sodium-octanote breath test. Plasma concentrations of glucose, insulin, C-peptide, glucagon, GLP-2, free fatty acids, free glycerol, and triglycerides were determined. RESULTS: GLP-2 administration led...... (P = .07). GLP-2 administration caused an approximately 15% reduction in pentagastrin-stimulated gastric acid and chloride secretion (P gastric emptying was not affected (P = .99). CONCLUSIONS: GLP-2 reduces gastric acid secretion but does not seem to have an influence on gastric......BACKGROUND & AIMS: The gut-derived peptide glucagon-like peptide 2 (GLP-2) has been suggested as a potential drug candidate for the treatment of various intestinal diseases. However, the acute effects of GLP-2 on gastric functions as well as on glucose and lipid homeostasis in humans are less well...

Brief Communication: Sexual dimorphic expression of myostatin and follistatin like-3 in a rat trans-generational under-nutrition model

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Mitchell Murray D

2010-05-01

Full Text Available Abstract The detrimental effects of maternal under-nutrition during gestation on fetal development are well known with an increased propensity of metabolic disorders identified in the adult offspring. Understanding exactly how and by which molecular pathways inadequate nutrition can impact upon offspring phenotype is critical and necessary for the development of treatment methods and ultimately prevention of any negative health effects. Myostatin, a negative regulator of muscle development, has recently been shown to effect glucose homeostasis and fat deposition. The involvement of myostatin in glucose metabolism and adipogenesis thus supports its ability to act in the continued alterations to the postnatal phenotype of the offspring. This hypothesis was examined in the current study using a trans-generational gestationally under-nourished rat model exposed to a high-fat (HF diet post-weaning. The body weight, body fat, plasma glucose and insulin concentrations of the offspring, both male and female, were investigated in relation to the protein expression of myostatin and its main inhibitor; follistatin like-3 (FSTL-3, in skeletal muscle of mature offspring. Sexual dimorphism was clearly evident in the majority of these measures, including myostatin and FSTL-3 expression. Generally males displayed higher (P myostatin precursor and dimer expression than females, which was especially apparent (P in both chow and HF trans-generationally undernourished (UNAD groups. In females only, myostatin precursor and dimer expression was altered by both trans-generational under-nutrition and postnatal diet. Overall FSTL-3 expression did not differ between sexes, although difference between sexes within certain treatments and diets were evident. Most notably, HF fed UNAD females had higher (P FSTL-3 expression than HF fed UNAD males. The former group also displayed higher (P FSTL-3 expression compared to all other female groups. In summary, myostatin may prove

Secreted Clusterin protein inhibits osteoblast differentiation of bone marrow mesenchymal stem cells by suppressing ERK1/2 signaling pathway

DEFF Research Database (Denmark)

Abdallah, Basem; Alzahrani, Abdullah M; Kassem, Moustapha

2018-01-01

Secreted Clusterin (sCLU, also known as Apolipoprotein J) is an anti-apoptotic glycoprotein involved in the regulation of cell proliferation, lipid transport, extracellular tissue remodeling and apoptosis. sCLU is expressed and secreted by mouse bone marrow-derived skeletal (stromal or mesenchyma...

Grass Carp Follisatin: Molecular Cloning, Functional Characterization, Dopamine D1 Regulation at Pituitary Level, and Implication in Growth Hormone Regulation

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Roger S. K. Fung

2017-08-01

Full Text Available Activin is involved in pituitary hormone regulation and its pituitary actions can be nullified by local production of its binding protein follistatin. In our recent study with grass carp, local release of growth hormone (GH was shown to induce activin expression at pituitary level, which in turn could exert an intrapituitary feedback to inhibit GH synthesis and secretion. To further examine the activin/follistatin system in the carp pituitary, grass carp follistatin was cloned and confirmed to be single-copy gene widely expressed at tissue level. At the pituitary level, follistatin signals could be located in carp somatotrophs, gonadotrophs, and lactotrophs. Functional expression also revealed that carp follistatin was effective in neutralizing activin’s action in stimulating target promoter with activin-responsive elements. In grass carp pituitary cells, follistatin co-treatment was found to revert activin inhibition on GH mRNA expression. Meanwhile, follistatin mRNA levels could be up-regulated by local production of activin but the opposite was true for dopaminergic activation with dopamine (DA or its agonist apomorphine. Since GH stimulation by DA via pituitary D1 receptor is well-documented in fish models, the receptor specificity for follistatin regulation by DA was also investigated. Using a pharmacological approach, the inhibitory effect of DA on follistatin gene expression was confirmed to be mediated by pituitary D1 but not D2 receptor. Furthermore, activation of D1 receptor by the D1-specific agonist SKF77434 was also effective in blocking follistatin mRNA expression induced by activin and GH treatment both in carp pituitary cells as well as in carp somatotrophs enriched by density gradient centrifugation. These results, as a whole, suggest that activin can interact with dopaminergic input from the hypothalamus to regulate follistatin expression in carp pituitary, which may contribute to GH regulation by activin/follistatin system

The Effect of an 8-week Aerobic Training and Weight-loss Diet on the Level of Serum Follistatin in Inactive Middle-aged Women

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M Tajik

2015-08-01

conclusion: The method of aerobic excercise along with the step-by-step diet can lead to achieving a healthy weight loss by increasing follistatin level and stimulating the catabolic process of body fal mass. Moreover, it may cause no ersion of fat free mass.

TROPHOBLASTIC β1 – GLYCOPROTEIN SYNTHESIS IN SEROPOSITIVE PREGNANT WOMEN

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R. N. Bogdanovich

2005-01-01

Full Text Available Abstract. The level of trophoblastic β1 – glycoprotein (SP–1 was determined in the blood sera of 200 healthy pregnant women and 184 women with threatened abortions in term till 20 weeks of pregnancy. In group of women experiencing recurrent abortions in 38 % cases antibodies to chorionic gonadotropin, in 39,5 % cases antibodies to phospholipids, in 25,5 % – antibodies to tireoglobulin were revealed in significant amounts. In 20,65 % lupus anticoagulant was found. The majority of women in this group had changes in homeostasis. The presence of autoantibodies during pregnancy is the unfavourable factor in the development of placental insufficiency. This is proved by the decreased secretion of trophoblastic β1 – glycoprotein – a marker of the fetal part of placenta. (Med. Immunol., 2005, vol.7, № 1, pp. 85588

Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain.

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Ou, Wu; Delisle, Josie; Jacques, Jerome; Shih, Joanna; Price, Graeme; Kuhn, Jens H; Wang, Vivian; Verthelyi, Daniela; Kaplan, Gerardo; Wilson, Carolyn A

2012-01-25

The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP1,2) is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD). We hypothesized that immunization with MLD-deleted GP1,2 (GPΔMLD) would induce cross-species immunity by making more conserved regions accessible to the immune system. To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs) bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP) that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. Cross-species neutralizing antibody and GP1,2-specific cellular immune responses were successfully induced. Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.

Orthobunyavirus ultrastructure and the curious tripodal glycoprotein spike.

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Thomas A Bowden

Full Text Available The genus Orthobunyavirus within the family Bunyaviridae constitutes an expanding group of emerging viruses, which threaten human and animal health. Despite the medical importance, little is known about orthobunyavirus structure, a prerequisite for understanding virus assembly and entry. Here, using electron cryo-tomography, we report the ultrastructure of Bunyamwera virus, the prototypic member of this genus. Whilst Bunyamwera virions are pleomorphic in shape, they display a locally ordered lattice of glycoprotein spikes. Each spike protrudes 18 nm from the viral membrane and becomes disordered upon introduction to an acidic environment. Using sub-tomogram averaging, we derived a three-dimensional model of the trimeric pre-fusion glycoprotein spike to 3-nm resolution. The glycoprotein spike consists mainly of the putative class-II fusion glycoprotein and exhibits a unique tripod-like arrangement. Protein-protein contacts between neighbouring spikes occur at membrane-proximal regions and intra-spike contacts at membrane-distal regions. This trimeric assembly deviates from previously observed fusion glycoprotein arrangements, suggesting a greater than anticipated repertoire of viral fusion glycoprotein oligomerization. Our study provides evidence of a pH-dependent conformational change that occurs during orthobunyaviral entry into host cells and a blueprint for the structure of this group of emerging pathogens.

Herpesvirus glycoproteins undergo multiple antigenic changes before membrane fusion.

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Daniel L Glauser

Full Text Available Herpesvirus entry is a complicated process involving multiple virion glycoproteins and culminating in membrane fusion. Glycoprotein conformation changes are likely to play key roles. Studies of recombinant glycoproteins have revealed some structural features of the virion fusion machinery. However, how the virion glycoproteins change during infection remains unclear. Here using conformation-specific monoclonal antibodies we show in situ that each component of the Murid Herpesvirus-4 (MuHV-4 entry machinery--gB, gH/gL and gp150--changes in antigenicity before tegument protein release begins. Further changes then occurred upon actual membrane fusion. Thus virions revealed their final fusogenic form only in late endosomes. The substantial antigenic differences between this form and that of extracellular virions suggested that antibodies have only a limited opportunity to block virion membrane fusion.

Secretion of glucagon-like peptide-1 in patients with type 2 diabetes mellitus

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Calanna, S; Christensen, M; Holst, Jens Juul

2013-01-01

We carried out a systematic review of clinical studies investigating glucagon-like peptide-1 (GLP-1) secretion in patients with type 2 diabetes and non-diabetic controls and performed meta-analyses of plasma total GLP-1 concentrations during an OGTT and/or meal test....

Interaction between Ebola Virus Glycoprotein and Host Toll-Like Receptor 4 Leads to Induction of Proinflammatory Cytokines and SOCS1 ▿ †

OpenAIRE

Okumura, Atsushi; Pitha, Paula M.; Yoshimura, Akihiko; Harty, Ronald N.

2009-01-01

Ebola virus initially targets monocytes and macrophages, which can lead to the release of proinflammatory cytokines and chemokines. These inflammatory cytokines are thought to contribute to the development of circulatory shock seen in fatal Ebola virus infections. Here we report that host Toll-like receptor 4 (TLR4) is a sensor for Ebola virus glycoprotein (GP) on virus-like particles (VLPs) and that resultant TLR4 signaling pathways lead to the production of proinflammatory cytokines and sup...

Vaccination with the Secreted Glycoprotein G of Herpes Simplex Virus 2 Induces Protective Immunity after Genital Infection.

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Önnheim, Karin; Ekblad, Maria; Görander, Staffan; Bergström, Tomas; Liljeqvist, Jan-Åke

2016-04-22

Herpes simplex virus 2 (HSV-2) infects the genital mucosa and establishes a life-long infection in sensory ganglia. After primary infection HSV-2 may reactivate causing recurrent genital ulcerations. HSV-2 infection is prevalent, and globally more than 400 million individuals are infected. As clinical trials have failed to show protection against HSV-2 infection, new vaccine candidates are warranted. The secreted glycoprotein G (sgG-2) of HSV-2 was evaluated as a prophylactic vaccine in mice using two different immunization and adjuvant protocols. The protocol with three intramuscular immunizations combining sgG-2 with cytosine-phosphate-guanine dinucleotide (CpG) motifs and alum induced almost complete protection from genital and systemic disease after intra-vaginal challenge with HSV-2. Robust immunoglobulin G (IgG) antibody titers were detected with no neutralization activity. Purified splenic CD4+ T cells proliferated and produced interferon-γ (IFN-γ) when re-stimulated with the antigen in vitro. sgG-2 + adjuvant intra-muscularly immunized mice showed a significant reduction of infectious HSV-2 and increased IFN-γ levels in vaginal washes. The HSV-2 DNA copy numbers were significantly reduced in dorsal root ganglia, spinal cord, and in serum at day six or day 21 post challenge. We show that a sgG-2 based vaccine is highly effective and can be considered as a novel candidate in the development of a prophylactic vaccine against HSV-2 infection.

Glucagon-like peptide 1 (GLP-1) suppresses ghrelin levels in humans via increased insulin secretion

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Hagemann, Dirk; Holst, Jens Juul; Gethmann, Arnica

2007-01-01

INTRODUCTION: Ghrelin is an orexigenic peptide predominantly secreted by the stomach. Ghrelin plasma levels rise before meal ingestion and sharply decline afterwards, but the mechanisms controlling ghrelin secretion are largely unknown. Since meal ingestion also elicits the secretion...... of the incretin hormone glucagon-like peptide 1 (GLP-1), we examined whether exogenous GLP-1 administration reduces ghrelin secretion in humans. PATIENTS AND METHODS: 14 healthy male volunteers were given intravenous infusions of GLP-1(1.2 pmol x kg(-1) min(-1)) or placebo over 390 min. After 30 min, a solid test...... meal was served. Venous blood was drawn frequently for the determination of glucose, insulin, C-peptide, GLP-1 and ghrelin. RESULTS: During the infusion of exogenous GLP-1 and placebo, GLP-1 plasma concentrations reached steady-state levels of 139+/-15 pmol/l and 12+/-2 pmol/l, respectively (p

Lipids in airway secretions

International Nuclear Information System (INIS)

Bhaskar, K.R.; DeFeudis O'Sullivan, D.; Opaskar-Hincman, H.; Reid, L.M.

1987-01-01

Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO 2 , (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors 14 C acetate and 14 C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway. (author)

Effects of preventing O-glycosylation on the secretion of human chorionic gonadotropin in Chinese hamster ovary cells

International Nuclear Information System (INIS)

Matzuk, M.M.; Krieger, M.; Corless, C.L.; Boime, I.

1987-01-01

Human chorionic gonadotropin (hCG) is a member of a family of heterodimeric glycoprotein hormones that have a common α subunit but differ in their hormone-specific β-subunits. The β subunit of hCG (hCGβ) is unique among the β subunits in that it contains four mucin-like O-linked oligosaccharides attached to a carboxyl-terminal extension. To study the effects of O-glycosylation on the secretion and assembly of hCG, expression vectors containing either hCGβ gene alone or together with the hCGα gene were transfected into a mutant Chinese hamster ovary cell line, 1d1D, which exhibits a reversible defect in O-glycosylation. The results reveal that hCGβ can be secreted normally in the absence of its O-linked oligosaccharides. hCGβ devoid of O-linked carbohydrate can also combine efficiently with hCGα and be secreted as an intact dimer. The authors conclude that in Chinese hamster ovary cells, the hCGβ O-linked chains play no role in the assembly and secretion of hCG. The normal and O-linked oligosaccharide-deficient forms of hCG secreted by these cells should prove useful in examining the role of O-linked chains on the biological function of hCG

Use of λgt11 to isolate genes for two pseudorabies virus glycoproteins with homology to herpes simplex virus and varicella-zoster virus glycoproteins

International Nuclear Information System (INIS)

Petrovskis, E.A.; Timmins, J.G.; Post, L.E.

1986-01-01

A library of pseudorabies virus (PRV) DNA fragments was constructed in the expression cloning vector λgt11. The library was screened with antisera which reacted with mixtures of PRV proteins to isolate recombinant bacteriophages expressing PRV proteins. By the nature of the λgt11 vector, the cloned proteins were expressed in Escherichia coli as β-galactosidase fusion proteins. The fusion proteins from 35 of these phages were purified and injected into mice to raise antisera. The antisera were screened by several different assays, including immunoprecipitation of [ 14 C]glucosamine-labeled PRV proteins. This method identified phages expressing three different PRV glycoproteins: the secreted glycoprotein, gX; gI; and a glycoprotein that had not been previously identified, which we designate gp63. The gp63 and gI genes map adjacent to each other in the small unique region of the PRV genome. The DNA sequence was determined for the region of the genome encoding gp63 and gI. It was found that gp63 has a region of homology with a herpes simplex virus type 1 (HSV-1) protein, encoded by US7, and also with varicella-zoster virus (VZV) gpIV. The gI protein sequence has a region of homology with HSV-1 gE and VZV gpI. It is concluded that PRV, HSV, and VZV all have a cluster of homologous glycoprotein genes in the small unique components of their genomes and that the organization of these genes is conserved

Requirements within the Ebola Viral Glycoprotein for Tetherin Antagonism

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Nathan H. Vande Burgt

2015-10-01

Full Text Available Tetherin is an interferon-induced, intrinsic cellular response factor that blocks release of numerous viruses, including Ebola virus, from infected cells. As with many viruses targeted by host factors, Ebola virus employs a tetherin antagonist, the viral glycoprotein (EboGP, to counteract restriction and promote virus release. Unlike other tetherin antagonists such as HIV-1 Vpu or KSHV K5, the features within EboGP needed to overcome tetherin are not well characterized. Here, we describe sequences within the EboGP ectodomain and membrane spanning domain (msd as necessary to relieve tetherin restriction of viral particle budding. Fusing the EboGP msd to a normally secreted form of the glycoprotein effectively promotes Ebola virus particle release. Cellular protein or lipid anchors could not substitute for the EboGP msd. The requirement for the EboGP msd was not specific for filovirus budding, as similar results were seen with HIV particles. Furthermore trafficking of chimeric proteins to budding sites did not correlate with an ability to counter tetherin. Additionally, we find that a glycoprotein construct, which mimics the cathepsin-activated species by proteolytic removal of the EboGP glycan cap and mucin domains, is unable to counteract tetherin. Combining these results suggests an important role for the EboGP glycan cap and msd in tetherin antagonism.

Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain

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Ou Wu

2012-01-01

Full Text Available Abstract Background The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP1,2 is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD. We hypothesized that immunization with MLD-deleted GP1,2 (GPΔMLD would induce cross-species immunity by making more conserved regions accessible to the immune system. Methods To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. Results Cross-species neutralizing antibody and GP1,2-specific cellular immune responses were successfully induced. Conclusion Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.

Determinants of foamy virus envelope glycoprotein mediated resistance to superinfection

International Nuclear Information System (INIS)

Berg, Angelika; Pietschmann, Thomas; Rethwilm, Axel; Lindemann, Dirk

2003-01-01

Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR. FV Env requires the extracellular domains of the SU and the TM subunits as well as membrane anchorage, efficient cell surface transport, and most probably correct subunit processing. This is in contrast to murine leukemia virus where secreted proteins comprising the receptor-binding domain in SU are sufficient to induce SIR. Furthermore, we demonstrate that cellular expression of the prototype FV envelope proteins induces SIR against pseudotypes with glycoproteins of other FV species, including of simian, feline, bovine, and equine origin. This implies that all of them use the same receptor molecules for viral entry

Multiple Pseudomonas species secrete exolysin-like toxins and provoke Caspase-1-dependent macrophage death.

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Basso, Pauline; Wallet, Pierre; Elsen, Sylvie; Soleilhac, Emmanuelle; Henry, Thomas; Faudry, Eric; Attrée, Ina

2017-10-01

Pathogenic bacteria secrete protein toxins that provoke apoptosis or necrosis of eukaryotic cells. Here, we developed a live-imaging method, based on incorporation of a DNA-intercalating dye into membrane-damaged host cells, to study the kinetics of primary bone marrow-derived macrophages (BMDMs) mortality induced by opportunistic pathogen Pseudomonas aeruginosa expressing either Type III Secretion System (T3SS) toxins or the pore-forming toxin, Exolysin (ExlA). We found that ExlA promotes the activation of Caspase-1 and maturation of interleukin-1β. BMDMs deficient for Caspase-1 and Caspase-11 were resistant to ExlA-induced death. Furthermore, by using KO BMDMs, we determined that the upstream NLRP3/ASC complex leads to the Caspase-1 activation. We also demonstrated that Pseudomonas putida and Pseudomonas protegens and the Drosophila pathogen Pseudomonas entomophila, which naturally express ExlA-like toxins, are cytotoxic toward macrophages and provoke the same type of pro-inflammatory death as does ExlA + P. aeruginosa. These results demonstrate that ExlA-like toxins of two-partner secretion systems from diverse Pseudomonas species activate the NLRP3 inflammasome and provoke inflammatory pyroptotic death of macrophages. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Two lectin-like receptors for alpha 1-acid glycoprotein in mouse testis

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Andersen, U O; Kirkeby, S; Bøg-Hansen, T C

1997-01-01

Three glycoforms of alpha 1-acid glycoprotein (AGP) were biotinylated to examine their binding in mouse testis by light microscopy. The transition from one stage to another in the spermatogenic cycle is marked with an appearance of a receptor for the Concanavalin A (Con A) non-reactive glycoform...

The secreted peptide PIP1 amplifies immunity through receptor-like kinase 7.

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Shuguo Hou

2014-09-01

Full Text Available In plants, innate immune responses are initiated by plasma membrane-located pattern recognition receptors (PRRs upon recognition of elicitors, including exogenous pathogen-associated molecular patterns (PAMPs and endogenous damage-associated molecular patterns (DAMPs. Arabidopsis thaliana produces more than 1000 secreted peptide candidates, but it has yet to be established whether any of these act as elicitors. Here we identified an A. thaliana gene family encoding precursors of PAMP-induced secreted peptides (prePIPs through an in-silico approach. The expression of some members of the family, including prePIP1 and prePIP2, is induced by a variety of pathogens and elicitors. Subcellular localization and proteolytic processing analyses demonstrated that the prePIP1 product is secreted into extracellular spaces where it is cleaved at the C-terminus. Overexpression of prePIP1 and prePIP2, or exogenous application of PIP1 and PIP2 synthetic peptides corresponding to the C-terminal conserved regions in prePIP1 and prePIP2, enhanced immune responses and pathogen resistance in A. thaliana. Genetic and biochemical analyses suggested that the receptor-like kinase 7 (RLK7 functions as a receptor of PIP1. Once perceived by RLK7, PIP1 initiates overlapping and distinct immune signaling responses together with the DAMP PEP1. PIP1 and PEP1 cooperate in amplifying the immune responses triggered by the PAMP flagellin. Collectively, these studies provide significant insights into immune modulation by Arabidopsis endogenous secreted peptides.

Defining glycoprotein cancer biomarkers by MS in conjunction with glycoprotein enrichment.

Science.gov (United States)

Song, Ehwang; Mechref, Yehia

2015-01-01

Protein glycosylation is an important and common post-translational modification. More than 50% of human proteins are believed to be glycosylated to modulate the functionality of proteins. Aberrant glycosylation has been correlated to several diseases, such as inflammatory skin diseases, diabetes mellitus, cardiovascular disorders, rheumatoid arthritis, Alzheimer's and prion diseases, and cancer. Many approved cancer biomarkers are glycoproteins which are not highly abundant proteins. Therefore, effective qualitative and quantitative assessment of glycoproteins entails enrichment methods. This chapter summarizes glycoprotein enrichment methods, including lectin affinity, immunoaffinity, hydrazide chemistry, hydrophilic interaction liquid chromatography, and click chemistry. The use of these enrichment approaches in assessing the qualitative and quantitative changes of glycoproteins in different types of cancers are presented and discussed. This chapter highlights the importance of glycoprotein enrichment techniques for the identification and characterization of new reliable cancer biomarkers.

High levels of DegU-P activate an Esat-6-like secretion system in Bacillus subtilis.

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Catarina Baptista

Full Text Available The recently discovered Type VII/Esat-6 secretion systems seem to be widespread among bacteria of the phyla Actinobacteria and Firmicutes. In some species they play an important role in pathogenic interactions with eukaryotic hosts. Several studies have predicted that the locus yukEDCByueBC of the non-pathogenic, Gram-positive bacterium Bacillus subtilis would encode an Esat-6-like secretion system (Ess. We provide here for the first time evidences for the functioning of this secretion pathway in an undomesticated B. subtilis strain. We show that YukE, a small protein with the typical features of the secretion substrates from the WXG100 superfamily is actively secreted to culture media. YukE secretion depends on intact yukDCByueBC genes, whose products share sequence or structural homology with known components of the S. aureus Ess. Biochemical characterization of YukE indicates that it exists as a dimer both in vitro and in vivo. We also show that the B. subtilis Ess essentially operates in late stationary growth phase in absolute dependence of phosphorylated DegU, the response regulator of the two-component system DegS-DegU. We present possible reasons that eventually have precluded the study of this secretion system in the B. subtilis laboratory strain 168.

Effect of chenodeoxycholic acid and the bile acid sequestrant colesevelam on glucagon-like peptide-1 secretion

DEFF Research Database (Denmark)

Hansen, Morten; Scheltema, Matthijs J; Sonne, David P

2016-01-01

AIMS: In patients with type 2 diabetes, rectal administration of bile acids increases glucagon-like peptide-1 (GLP-1) secretion and reduces plasma glucose. In addition, oral bile acid sequestrants (BASs) reduce blood glucose by an unknown mechanism. In this study we evaluated the effects...... of the primary human bile acid, chenodeoxycholic acid (CDCA), and the BAS, colesevelam, instilled into the stomach, on plasma levels of GLP-1, glucose-dependent insulinotropic polypeptide, glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin as well as gastric emptying, gallbladder volume, appetite......, and delayed gastric emptying. We speculate that bile acid-induced activation of TGR5 on L cells increases GLP-1 secretion, which in turn may result in amplification of glucose-stimulated insulin secretion. Furthermore our data suggest that colesevelam does not have an acute effect on GLP-1 secretion in humans....

Induction of IL-12 Production in Human Peripheral Monocytes by Trypanosoma cruzi Is Mediated by Glycosylphosphatidylinositol-Anchored Mucin-Like Glycoproteins and Potentiated by IFN-γ and CD40-CD40L Interactions

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Lúcia Cristina Jamli Abel

2014-01-01

Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, is characterized by immunopathology driven by IFN-γ secreting Th1-like T cells. T. cruzi has a thick coat of mucin-like glycoproteins covering its surface, which plays an important role in parasite invasion and host immunomodulation. It has been extensively described that T. cruzi or its products—like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins—are potent inducers of proinflammatory responses (i.e., cytokines and NO production by IFN-γ primed murine macrophages. However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells. We therefore decided to further investigate the in vitro cytokine production profile from human mononuclear cells from uninfected donors exposed to T. cruzi as well as tGPI-mucins. We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ. Our findings suggest that the polarized T1-type cytokine profile seen in T. cruzi infected patients might be a long-term effect of IL-12 production induced by lifelong exposure to T. cruzi tGPI-mucins.

Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes

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Nauck, M A; Vardarli, I; Deacon, C F

2011-01-01

The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP......-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency...... with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some...

In-vitro secretion of inhibin-like activity by Sertoli cells from normal and prenatally irradiated immature rats

International Nuclear Information System (INIS)

Ultee-van Gessel, A.M.; Leemborg, F.G.; Jong, F.H. de; Molen, H.J. van der

1986-01-01

The influence of in-vitro conditions on the production of inhibin by Sertoli cells from 21-day-old normal and prenatally irradiated rat testes was studied by measuring inhibin activity in culture media, using the suppression of the release of FSH from cultured rat pituitary cells. Sertoli cells secreted inhibin-like activity during at least 21 days of culture, and cells cultured at 37 0 C produced significantly more inhibin than those cultured at 32 0 C. The presence of fetal calf serum had no significant effect on inhibin production at 32 0 C, while at 37 0 C the production was decreased. The presence of ovine FSH stimulated inhibin secretion, while inhibin concentrations in Sertoli cell culture media were decreased after the addition of testosterone. Testosterone, added together with ovine FSH, suppressed inhibin secretion when compared with the levels found in the presence of FSH alone. The presence of spermatogenic cells decreased the release of inhibin. From these results it was concluded that both Sertoli cells isolated from normal immature rat testes and those from testes without spermatogenic cells can secrete inhibin-like activity in culture. A number of discrepancies with in-vivo observations was observed. (author)

Bile acids induce glucagon-like peptide 2 secretion with limited effects on intestinal adaptation in early weaned pigs

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Ipharraguerre, Ignacio R; Tedó, Gemma; Menoyo, David

2013-01-01

Early weaning is a stressful event characterized by a transient period of intestinal atrophy that may be mediated by reduced secretion of glucagon-like peptide (GLP) 2. We tested whether enterally fed bile acids or plant sterols could increase nutrient-dependent GLP-2 secretion and improve.......05) but did not affect plasma GLP-1 and feed intake. The intestinal expression of glucagon-like peptide 2 receptor, sodium-dependent bile acid transporter, farnesoid X receptor, and guanosine protein-coupled bile acid receptor genes were not affected by CDC treatment. The intragastric administration of CDC...

Apparent inhibition of β-fructosidase secretion by tunicamycin may be explained by breakdown of the unglycosylated protein during secretion

International Nuclear Information System (INIS)

Faye, L.; Chrispeels, M.J.

1989-01-01

Suspension-cultured carrot (Daucus carota) cells synthesize and secrete β-fructosidase, a glycoprotein with asparagine-linked glycans. Treatment of the cells with tunicamycin completely inhibits the apparent secretion of β-fructosidase as measured by the accumulation of the 35 S-labelled protein in the cell wall or the culture medium. In the past, such a result has been interpreted as an inhibition of secretion by tunicamycin, but we suggest another explanation based on the following results. In the presence of tunicamycin, unglycosylated β-fructosidase is synthesized and is associated with an endoplasmic-reticulum-rich microsomal fraction. Pulse-chase experiments show that the unglycosylated β-fructosidase does not remain in the cells and appears to be secreted in the same way as glycosylated β-fructosidase; however, no radioactive, unglycosylated β-fructosidase accumulates extracellularly (cell wall or medium). Protoplasts obtained from carrot cells secrete β-fructosidase protein and activity, and treatment of the protoplasts with tunicamycin results in the synthesis of unglycosylated β-fructosidase. In the presence of tunicamycin, there is no accumulation of β-fructosidase activity or unglycosylated β-fructosidase polypeptide in the protoplast incubation medium. These results are consistent with the interpretation that the glycans of β-fructosidase are necessary for its stability, and that in these suspension-cultured cells, the unglycosylated enzyme is degraded during the last stage(s) of secretion, or immediately after its arrival in the wall

Glycoprotein on cell surfaces

International Nuclear Information System (INIS)

Muramatsu, T.

1975-01-01

There are conjugated polysaccharides in cell membranes and outside of animal cells, and they play important role in the control of cell behavior. In this paper, the studies on the glycoprotein on cell surfaces are reported. It was found that the glycoprotein on cell surfaces have both N-glycoside type and O-glycoside type saccharic chains. Therefore it can be concluded that the basic structure of the saccharic chains in the glycoprotein on cell surfaces is similar to that of blood serum and body fluid. The main glycoprotein in the membranes of red blood corpuscles has been studied most in detail, and it also has both types of saccharic chains. The glycoprotein in liver cell membranes was found to have only the saccharic chains of acid type and to be in different pattern from that in endoplasmic reticula and nuclear membranes, which also has the saccharic chains of neutral type. The structure of the saccharic chains of H-2 antigen, i.e. the peculiar glycoprotein on the surfaces of lymph system cells, has been studied, and it is similar to the saccharic chains of glycoprotein in blood serum. The saccharic chain structures of H-2 antigen and TL antigen are different. TL, H-2 (D), Lna and H-2 (K) are the glycoprotein on cell surfaces, and are independent molecules. The analysis of the saccharic chain patterns on cell surfaces was carried out, and it was shown that the acid type saccharic chains were similar to those of ordinary glycoprotein, because the enzyme of pneumococci hydrolyzed most of the acid type saccharic chains. The change of the saccharic chain patterns of glycoprotein on cell surfaces owing to canceration and multiplication is complex matter. (Kako, I.)

Metformin as a prevention and treatment for preeclampsia: effects on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion and endothelial dysfunction.

Science.gov (United States)

Brownfoot, Fiona C; Hastie, Roxanne; Hannan, Natalie J; Cannon, Ping; Tuohey, Laura; Parry, Laura J; Senadheera, Sevvandi; Illanes, Sebastian E; Kaitu'u-Lino, Tu'uhevaha J; Tong, Stephen

2016-03-01

Preeclampsia is associated with placental ischemia/hypoxia and secretion of soluble fms-like tyrosine kinase 1 and soluble endoglin into the maternal circulation. This causes widespread endothelial dysfunction that manifests clinically as hypertension and multisystem organ injury. Recently, small molecule inhibitors of hypoxic inducible factor 1α have been found to reduce soluble fms-like tyrosine kinase 1 and soluble endoglin secretion. However, their safety profile in pregnancy is unknown. Metformin is safe in pregnancy and is also reported to inhibit hypoxic inducible factor 1α by reducing mitochondrial electron transport chain activity. The purposes of this study were to determine (1) the effects of metformin on placental soluble fms-like tyrosine kinase 1 and soluble endoglin secretion, (2) to investigate whether the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion are regulated through the mitochondrial electron transport chain, and (3) to examine its effects on endothelial dysfunction, maternal blood vessel vasodilation, and angiogenesis. We performed functional (in vitro and ex vivo) experiments using primary human tissues to examine the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion from placenta, endothelial cells, and placental villous explants. We used succinate, mitochondrial complex II substrate, to examine whether the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion were mediated through the mitochondria. We also isolated mitochondria from preterm preeclamptic placentas and gestationally matched control subjects and measured mitochondrial electron transport chain activity using kinetic spectrophotometric assays. Endothelial cells or whole maternal vessels were incubated with metformin to determine whether it rescued endothelial dysfunction induced by either tumor necrosis factor-α (to endothelial cells) or placenta villous

Utilization by the isolated perfused rat liver of N-acetyl-D-(1-/sup 14/C)galactosamine and N-brace/sup 3/H)-acetyl-D-galactosamine for the biosynthesis of glycoproteins

Energy Technology Data Exchange (ETDEWEB)

MacNicoll, A D; Wusteman, F S; Powell, G M; Curtis, C G [University Coll., Cardiff (UK)

1978-08-15

The isolated perfused rat liver system has been used to monitor the utilization of N-(/sup 3/H)acetyl-D-galactosamine and N-acetyl-D-(1-/sup 14/C)galactosamine for the biosynthesis of radiolabeled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.

Engineering and Characterization of a Fluorescent Native-Like HIV-1 Envelope Glycoprotein Trimer

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Kwinten Sliepen

2015-10-01

Full Text Available Generation of a stable, soluble mimic of the HIV-1 envelope glycoprotein (Env trimer on the virion surface has been considered an important first step for developing a successful HIV-1 vaccine. Recently, a soluble native-like Env trimer (BG505 SOSIP.664 has been described. This protein has facilitated major advances in the HIV-1 vaccine field, since it was the first Env immunogen that induced consistent neutralizing antibodies against a neutralization-resistant (tier 2 virus. Moreover, BG505 SOSIP.664 enabled elucidation of the atomic resolution structure of the Env trimer and facilitated the isolation and characterization of new broadly neutralizing antibodies against HIV-1. Here, we designed and characterized the BG505 SOSIP.664 trimer fused to fluorescent superfolder GFP (sfGFP, a GFP variant that allows efficient folding (BG505 SOSIP.664-sfGFP. Despite the presence of the sfGFP, the Env protein largely retained its morphology, antigenicity, glycan composition, and thermostability. In addition, we show that BG505 SOSIP.664-sfGFP can be used for fluorescence-based assays, such as flow cytometry.

The short mRNA isoform of the immunoglobulin superfamily, member 1 gene encodes an intracellular glycoprotein.

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Ying Wang

Full Text Available Mutations in the immunoglobulin superfamily, member 1 gene (IGSF1/Igsf1 cause an X-linked form of central hypothyroidism. The canonical form of IGSF1 is a transmembrane glycoprotein with 12 immunoglobulin (Ig loops. The protein is co-translationally cleaved into two sub-domains. The carboxyl-terminal domain (CTD, which contains the last 7 Ig loops, is trafficked to the plasma membrane. Most pathogenic mutations in IGSF1 map to the portion of the gene encoding the CTD. IGSF1/Igsf1 encodes a variety of transcripts. A little studied, but abundant splice variant encodes a truncated form of the protein, predicted to contain the first 2 Ig loops of the full-length IGSF1. The protein (hereafter referred to as IGSF1 isoform 2 or IGSF1-2 is likely retained in most individuals with IGSF1 mutations. Here, we characterized basic biochemical properties of the protein as a foray into understanding its potential function. IGSF1-2, like the IGSF1-CTD, is a glycoprotein. In both mouse and rat, the protein is N-glycosylated at a single asparagine residue in the first Ig loop. Contrary to earlier predictions, neither the murine nor rat IGSF1-2 is secreted from heterologous or homologous cells. In addition, neither protein associates with the plasma membrane. Rather, IGSF1-2 appears to be retained in the endoplasmic reticulum. Whether the protein plays intracellular functions or is trafficked through the secretory pathway under certain physiologic or pathophysiologic conditions has yet to be determined.

The alpha cell expresses glucagon-like peptide-2 receptors and glucagon-like peptide-2 stimulates glucagon secretion from the rat pancreas

DEFF Research Database (Denmark)

de Heer, J; Pedersen, J; Orskov, C

2007-01-01

AIMS/HYPOTHESIS: Glucagon-like peptide-2 (GLP-2) is a gut hormone regulating intestinal growth and nutrient absorption. Recently, GLP-2 has been reported to stimulate glucagon secretion in healthy humans. We sought to clarify the mechanism and physiological significance of this endocrine effect. ...... of the glucagonotropic action of GLP-2 in humans....

Human pituitary and placental hormones control human insulin-like growth factor II secretion in human granulosa cells

International Nuclear Information System (INIS)

Ramasharma, K.; Li, C.H.

1987-01-01

Human granulosa cells cultured with calf serum actively proliferated for 18-20 generations and secreted progesterone into the medium; progesterone levels appeared to decline with increase in generation number. Cells cultured under serum-free conditions secreted significant amounts of progesterone and insulin-like growth factor II (IGF-II). The progesterone secretion was enhanced by the addition of human follitropin, lutropin, and chorionic gonadotropin but not by growth hormone. These cells, when challenged to varying concentrations of human growth hormone, human chorionic somatomammotropin, human prolactin, chorionic gonadotropin, follitropin, and lutropin, secreted IGF-II into the medium as measured by specific IGF-II RIA. Among these human hormones, chorionic gonadotropin, follitropin, and lutropin were most effective in inducing IGF-II secretion from these cells. When synthetic lutropin-releasing hormone and α-inhibin-92 were tested, only lutropin-releasing hormone was effective in releasing IGF-II. The results described suggest that cultured human granulosa cells can proliferate and actively secrete progesterone and IGF-II into the medium. IGF-II production in human granulosa cells was influenced by a multi-hormonal complex including human growth hormone, human chorionic somatomammotropin, and prolactin

Enhancement of Ebola Virus Infection via Ficolin-1 Interaction with the Mucin Domain of GP Glycoprotein.

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Favier, Anne-Laure; Gout, Evelyne; Reynard, Olivier; Ferraris, Olivier; Kleman, Jean-Philippe; Volchkov, Viktor; Peyrefitte, Christophe; Thielens, Nicole M

2016-06-01

Ebola virus infection requires the surface viral glycoprotein to initiate entry into the target cells. The trimeric glycoprotein is a highly glycosylated viral protein which has been shown to interact with host C-type lectin receptors and the soluble complement recognition protein mannose-binding lectin, thereby enhancing viral infection. Similarly to mannose-binding lectin, ficolins are soluble effectors of the innate immune system that recognize particular glycans at the pathogen surface. In this study, we demonstrate that ficolin-1 interacts with the Zaire Ebola virus (EBOV) glycoprotein, and we characterized this interaction by surface plasmon resonance spectroscopy. Ficolin-1 was shown to bind to the viral glycoprotein with a high affinity. This interaction was mediated by the fibrinogen-like recognition domain of ficolin-1 and the mucin-like domain of the viral glycoprotein. Using a ficolin-1 control mutant devoid of sialic acid-binding capacity, we identified sialylated moieties of the mucin domain to be potential ligands on the glycoprotein. In cell culture, using both pseudotyped viruses and EBOV, ficolin-1 was shown to enhance EBOV infection independently of the serum complement. We also observed that ficolin-1 enhanced EBOV infection on human monocyte-derived macrophages, described to be major viral target cells,. Competition experiments suggested that although ficolin-1 and mannose-binding lectin recognized different carbohydrate moieties on the EBOV glycoprotein, the observed enhancement of the infection likely depended on a common cellular receptor/partner. In conclusion, ficolin-1 could provide an alternative receptor-mediated mechanism for enhancing EBOV infection, thereby contributing to viral subversion of the host innate immune system. A specific interaction involving ficolin-1 (M-ficolin), a soluble effector of the innate immune response, and the glycoprotein (GP) of EBOV was identified. Ficolin-1 enhanced virus infection instead of tipping the

Secreted Progranulin Is a Homodimer and Is Not a Component of High Density Lipoproteins (HDL)*

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Nguyen, Andrew D.; Nguyen, Thi A.; Cenik, Basar; Yu, Gang; Herz, Joachim; Walther, Tobias C.; Davidson, W. Sean; Farese, Robert V.

2013-01-01

Progranulin is a secreted glycoprotein, and the GRN gene is mutated in some cases of frontotemporal dementia. Progranulin has also been implicated in cell growth, wound healing, inflammation, and cancer. We investigated the molecular nature of secreted progranulin and provide evidence that progranulin exists as a homodimer. Although recombinant progranulin has a molecular mass of ∼85 kDa by SDS-PAGE, it elutes in fractions corresponding to ∼170–180 kDa by gel-filtration chromatography. Additionally, recombinant progranulin can be intermolecularly cross-linked, yielding a complex corresponding to a dimer (∼180 kDa), and progranulins containing different epitope tags physically interact. In plasma, progranulin similarly forms complexes of ∼180–190 kDa. Although progranulin partially co-fractionated with high density lipoproteins (HDL) by gel-filtration chromatography, we found no evidence that progranulin in mouse or human plasma is a component of HDL either by ultracentrifugation or by lipid binding assays. We conclude that circulating progranulin exists as a dimer and is not likely a component of HDL. PMID:23364791

Secreted progranulin is a homodimer and is not a component of high density lipoproteins (HDL).

Science.gov (United States)

Nguyen, Andrew D; Nguyen, Thi A; Cenik, Basar; Yu, Gang; Herz, Joachim; Walther, Tobias C; Davidson, W Sean; Farese, Robert V

2013-03-22

Progranulin is a secreted glycoprotein, and the GRN gene is mutated in some cases of frontotemporal dementia. Progranulin has also been implicated in cell growth, wound healing, inflammation, and cancer. We investigated the molecular nature of secreted progranulin and provide evidence that progranulin exists as a homodimer. Although recombinant progranulin has a molecular mass of ∼85 kDa by SDS-PAGE, it elutes in fractions corresponding to ∼170-180 kDa by gel-filtration chromatography. Additionally, recombinant progranulin can be intermolecularly cross-linked, yielding a complex corresponding to a dimer (∼180 kDa), and progranulins containing different epitope tags physically interact. In plasma, progranulin similarly forms complexes of ∼180-190 kDa. Although progranulin partially co-fractionated with high density lipoproteins (HDL) by gel-filtration chromatography, we found no evidence that progranulin in mouse or human plasma is a component of HDL either by ultracentrifugation or by lipid binding assays. We conclude that circulating progranulin exists as a dimer and is not likely a component of HDL.

Differential staining of Western blots of human secreted glycoproteins from serum, milk, saliva, and seminal fluid using lectins displaying diverse sugar specificities.

Science.gov (United States)

Gilboa-Garber, Nechama; Lerrer, Batya; Lesman-Movshovich, Efrat; Dgani, Orly

2005-12-01

Human milk, serum, saliva, and seminal fluid glycoproteins (gps) nourish and protect newborn and adult tissues. Their saccharides, which resemble cell membrane components, may block pathogen adhesion and infection. In the present study, they were examined by a battery of lectins from plants, animals, and bacteria, using hemagglutination inhibition and Western blot analyses. The lectins included galactophilic ones from Aplysia gonad, Erythrina corallodendron, Maclura pomifera (MPL), peanut, and Pseudomonas aeruginosa (PA-IL); fucose-binding lectins from Pseudomonas aeruginosa (PA-IIL), Ralstonia solanacearum (RSL), and Ulex europaeus (UEA-I), and mannose/glucose-binding Con A. The results demonstrated the chosen lectin efficiency for differential analysis of human secreted gps as compared to CBB staining. They unveiled the diversity of these body fluid gp glycans (those of the milk and seminal fluid being highest): the milk gps interacted most strongly with PA-IIL, followed by RSL; the saliva gps with RSL, followed by PA-IIL and MPL; the serum gps with Con A and MPL, followed by PA-IIL and RSL, and the seminal plasma gps with RSL and MPL, followed by UEA-I and PA-IIL. The potential usage of these lectins as probes for scientific, industrial, and medical purposes, and for quality control of the desired gps is clearly indicated.

Effect of truncated glucagon-like peptide-1 [proglucagon-(78-107) amide] on endocrine secretion from pig pancreas, antrum, and nonantral stomach

DEFF Research Database (Denmark)

Orskov, C; Holst, J J; Nielsen, O V

1988-01-01

We studied the effect of truncated glucagon-like peptide-1 [naturally occurring GLP-1; proglucagon-(78-107) amide], a potent insulinotropic peptide from the pig ileum, on endocrine and exocrine secretion of potential gastrointestinal target organs using isolated perfused preparations of the porcine...... pancreas, antrum, and nonantral part of the stomach. Truncated GLP-1 significantly increased somatostatin secretion from the pancreas at 10(-10) mol/liter and more than doubled the secretion at 10(-9) mol/liter, but had no effect on either somatostatin or gastrin secretion from the antrum...... or on somatostatin secretion from the nonantral stomach in concentrations up to 10(-8) mol/liter. Insulin secretion from the pancreas (with 7 mmol/liter glucose in the perfusate) increased 2-fold with truncated GLP-1 at 10(-10) mol/liter and almost 5-fold at 10(-9) mol/liter. Pancreatic glucagon secretion...

Glucose-induced glucagon-like Peptide 1 secretion is deficient in patients with non-alcoholic fatty liver disease.

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Christine Bernsmeier

Full Text Available The incretins glucagon-like peptide-1 (GLP-1 and glucose-dependent insulinotropic polypeptide (GIP are gastrointestinal peptide hormones regulating postprandial insulin release from pancreatic β-cells. GLP-1 agonism is a treatment strategy in Type 2 diabetes and is evaluated in Non-alcoholic fatty liver disease (NAFLD. However, the role of incretins in its pathophysiology is insufficiently understood. Studies in mice suggest improvement of hepatic steatosis by GLP-1 agonism. We determined the secretion of incretins after oral glucose administration in non-diabetic NAFLD patients.N=52 patients (n=16 NAFLD and n=36 Non-alcoholic steatohepatitis (NASH patients and n=50 matched healthy controls were included. Standardized oral glucose tolerance test was performed. Glucose, insulin, glucagon, GLP-1 and GIP plasma levels were measured sequentially for 120 minutes after glucose administration.Glucose induced GLP-1 secretion was significantly decreased in patients compared to controls (p<0.001. In contrast, GIP secretion was unchanged. There was no difference in GLP-1 and GIP secretion between NAFLD and NASH subgroups. All patients were insulin resistant, however HOMA2-IR was highest in the NASH subgroup. Fasting and glucose-induced insulin secretion was higher in NAFLD and NASH compared to controls, while the glucose lowering effect was diminished. Concomitantly, fasting glucagon secretion was significantly elevated in NAFLD and NASH.Glucose-induced GLP-1 secretion is deficient in patients with NAFLD and NASH. GIP secretion is contrarily preserved. Insulin resistance, with hyperinsulinemia and hyperglucagonemia, is present in all patients, and is more severe in NASH compared to NAFLD. These pathophysiologic findings endorse the current evaluation of GLP-1 agonism for the treatment of NAFLD.

Recent Progress in Electrochemical Biosensors for Glycoproteins

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Uichi Akiba

2016-12-01

Full Text Available This review provides an overview of recent progress in the development of electrochemical biosensors for glycoproteins. Electrochemical glycoprotein sensors are constructed by combining metal and carbon electrodes with glycoprotein-selective binding elements including antibodies, lectin, phenylboronic acid and molecularly imprinted polymers. A recent trend in the preparation of glycoprotein sensors is the successful use of nanomaterials such as graphene, carbon nanotube, and metal nanoparticles. These nanomaterials are extremely useful for improving the sensitivity of glycoprotein sensors. This review focuses mainly on the protocols for the preparation of glycoprotein sensors and the materials used. Recent improvements in glycoprotein sensors are discussed by grouping the sensors into several categories based on the materials used as recognition elements.

The Effect of 8 Weeks High-intensity Interval Training on Myostatin and Follistatin Gene Expression in Gastrocnemius Muscle of the Rats

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Soheil Biglari

2018-04-01

Full Text Available Abstract Background: The purpose of the present study is to investigate the effect of 8 weeks High-intensity Interval Training (HIIT on the expression of two muscle growth regulating genes (myostatin and follistatin in gastrocnemius muscle of healthy male rats. Materials and Methods: 16 male Wistar rats were randomly divided into two groups in the same number: control and HIIT. HIIT program was underwent 40 min each session, three sessions in a week for eight weeks. Each exercise training session consisted of 5 min warm-up and cool-down at 40-50 % VO2max, 30 min interval running including 4 min high-intensity (85-90% VO2max and 2 min active recovery (at 50-60% VO2max. Rats in control group did not do any exercise training program. 48 h after the last training session, rats` gastrocnemius muscle was extracted and the expression of myostatin and follistatin genes was determined by Real Time-PCR. For statistical data analysis, independent t-test was used. Results: The expression of myostatin was significantly reduced 68% in HIIT group in comparison with the control group (p0.05. Gastrocnemius muscle weight was significantly increased 23% in the HIIT group compared to the control group (p<0.05. Conclusion: Results indicated that HIIT lead to significant reduction in the expression of myostatin gene and increase in the weight of gastrocnemius muscle in rats.

Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion

DEFF Research Database (Denmark)

Witte, Anne-Barbara; Grybäck, Per; Jacobsson, Hans

2011-01-01

Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma ...

Glucagon-like peptide-1 secretion in women with gestational diabetes mellitus during and after pregnancy.

Science.gov (United States)

Lencioni, C; Resi, V; Romero, F; Lupi, R; Volpe, L; Bertolotto, A; Ghio, A; Del Prato, S; Marchetti, P; Di Cianni, G

2011-10-01

Gestational diabetes mellitus (GDM) predisposes women to future development of Type 2 diabetes mellitus (DM2) and the two conditions share similar metabolic alterations. Recent observations suggest that a defective glucose stimulated insulin secretion by glucagon-like peptide-1 (GLP- 1) plays a role in the pathogenesis of DM2. Whether such a defect is impaired in GDM remains to be ascertained. We have determined GLP-1 secretion in response to oral glucose tolerance test (OGTT) in GDM and normal glucose tolerance (NGT) during and after pregnancy. 100-g-3h OGTT was performed in 12 GDM and 16 NGT women at 27.3 ± 4.1 weeks of gestation, for determination of plasma GLP-1, glucose, insulin, and C-peptide. Insulin sensitivity (ISI) and insulin secretion (first and second phase); as well as ISI-secretion index (ISSI) were also derived. NGT and GDM women were comparable for age pre-pregnancy body mass index (BMI) and weight gain. GDM had higher glucose area under the curve (AUC): 27,575.5 ± 3448 vs 20,685.88 ± 2715 mg/dl min (pwomen (2542 ± 273 vs 10,092 ± 7367 pmol·l-1·min-1, pwomen is inadequate for the prevailing glycemic levels both in pregnancy and post partum. Moreover, we cannot exclude that other important aspects of the incretin effect may be involved in GDM development.

Progranulin, a glycoprotein deficient in frontotemporal dementia, is a novel substrate of several protein disulfide isomerase family proteins.

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Sandra Almeida

Full Text Available The reduced production or activity of the cysteine-rich glycoprotein progranulin is responsible for about 20% of cases of familial frontotemporal dementia. However, little is known about the molecular mechanisms that govern the level and secretion of progranulin. Here we show that progranulin is expressed in mouse cortical neurons and more prominently in mouse microglia in culture and is abundant in the endoplasmic reticulum (ER and Golgi. Using chemical crosslinking, immunoprecipitation, and mass spectrometry, we found that progranulin is bound to a network of ER Ca(2+-binding chaperones including BiP, calreticulin, GRP94, and four members of the protein disulfide isomerase (PDI family. Loss of ERp57 inhibits progranulin secretion. Thus, progranulin is a novel substrate of several PDI family proteins and modulation of the ER chaperone network may be a therapeutic target for controlling progranulin secretion.

Glycoproteins functionalized natural and synthetic polymers for prospective biomedical applications: A review.

Science.gov (United States)

Tabasum, Shazia; Noreen, Aqdas; Kanwal, Arooj; Zuber, Mohammad; Anjum, Muhammad Naveed; Zia, Khalid Mahmood

2017-05-01

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement. Copyright © 2017 Elsevier B.V. All rights reserved.

Secreted herpes simplex virus-2 glycoprotein G modifies NGF-TrkA signaling to attract free nerve endings to the site of infection.

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Jorge Rubén Cabrera

2015-01-01

Full Text Available Herpes simplex virus type 1 (HSV-1 and HSV-2 are highly prevalent viruses that cause a variety of diseases, from cold sores to encephalitis. Both viruses establish latency in peripheral neurons but the molecular mechanisms facilitating the infection of neurons are not fully understood. Using surface plasmon resonance and crosslinking assays, we show that glycoprotein G (gG from HSV-2, known to modulate immune mediators (chemokines, also interacts with neurotrophic factors, with high affinity. In our experimental model, HSV-2 secreted gG (SgG2 increases nerve growth factor (NGF-dependent axonal growth of sympathetic neurons ex vivo, and modifies tropomyosin related kinase (TrkA-mediated signaling. SgG2 alters TrkA recruitment to lipid rafts and decreases TrkA internalization. We could show, with microfluidic devices, that SgG2 reduced NGF-induced TrkA retrograde transport. In vivo, both HSV-2 infection and SgG2 expression in mouse hindpaw epidermis enhance axonal growth modifying the termination zone of the NGF-dependent peptidergic free nerve endings. This constitutes, to our knowledge, the discovery of the first viral protein that modulates neurotrophins, an activity that may facilitate HSV-2 infection of neurons. This dual function of the chemokine-binding protein SgG2 uncovers a novel strategy developed by HSV-2 to modulate factors from both the immune and nervous systems.

Structure of the Membrane Anchor of Pestivirus Glycoprotein Erns, a Long Tilted Amphipathic Helix

Science.gov (United States)

Aberle, Daniel; Muhle-Goll, Claudia; Bürck, Jochen; Wolf, Moritz; Reißer, Sabine; Luy, Burkhard; Wenzel, Wolfgang; Ulrich, Anne S.; Meyers, Gregor

2014-01-01

Erns is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the Erns membrane contact, processing and secretion. PMID:24586172

Biochemical characterization and comparison of aspartylglucosaminidases secreted in venom of the parasitoid wasps Asobara tabida and Leptopilina heterotoma.

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Quentin Coulette

Full Text Available Aspartylglucosaminidase (AGA is a low-abundance intracellular enzyme that plays a key role in the last stage of glycoproteins degradation, and whose deficiency leads to human aspartylglucosaminuria, a lysosomal storage disease. Surprisingly, high amounts of AGA-like proteins are secreted in the venom of two phylogenetically distant hymenopteran parasitoid wasp species, Asobara tabida (Braconidae and Leptopilina heterotoma (Cynipidae. These venom AGAs have a similar domain organization as mammalian AGAs. They share with them key residues for autocatalysis and activity, and the mature α- and β-subunits also form an (αβ2 structure in solution. Interestingly, only one of these AGAs subunits (α for AtAGA and β for LhAGA is glycosylated instead of the two subunits for lysosomal human AGA (hAGA, and these glycosylations are partially resistant to PGNase F treatment. The two venom AGAs are secreted as fully activated enzymes, they have a similar aspartylglucosaminidase activity and are both also efficient asparaginases. Once AGAs are injected into the larvae of the Drosophila melanogaster host, the asparaginase activity may play a role in modulating their physiology. Altogether, our data provide new elements for a better understanding of the secretion and the role of venom AGAs as virulence factors in the parasitoid wasps' success.

Rotavirus NSP4 is secreted from infected cells as an oligomeric lipoprotein and binds to glycosaminoglycans on the surface of non-infected cells

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Didsbury Alicia

2011-12-01

Full Text Available Abstract Background Nonstructural glycoprotein 4 (NSP4 encoded by rotavirus is the only viral protein currently believed to function as an enterotoxin. NSP4 is synthesized as an intracellular transmembrane glycoprotein and as such is essential for virus assembly. Infection of polarized Caco-2 cells with rotavirus also results in the secretion of glycosylated NSP4 apparently in a soluble form despite retention of its transmembrane domain. We have examined the structure, solubility and cell-binding properties of this secreted form of NSP4 to further understand the biochemical basis for its enterotoxic function. We show here that NSP4 is secreted as discrete detergent-sensitive oligomers in a complex with phospholipids and demonstrate that this secreted form of NSP4 can bind to glycosaminoglycans present on the surface of a range of different cell types. Methods NSP4 was purified from the medium of infected cells after ultracentrifugation and ultrafiltration by successive lectin-affinity and ion exchange chromatography. Oligomerisation of NSP4 was examined by density gradient centrifugation and chemical crosslinking and the lipid content was assessed by analytical thin layer chromatography and flame ionization detection. Binding of NSP4 to various cell lines was measured using a flow cytometric-based assay. Results Secreted NSP4 formed oligomers that contained phospholipid but dissociated to a dimeric species in the presence of non-ionic detergent. The purified glycoprotein binds to the surface of various non-infected cells of distinct lineage. Binding of NSP4 to HT-29, a cell line of intestinal origin, is saturable and independent of divalent cations. Complementary biochemical approaches reveal that NSP4 binds to sulfated glycosaminoglycans on the plasma membrane. Conclusion Our study is the first to analyze an authentic (i.e. non-recombinant form of NSP4 that is secreted from virus-infected cells. Despite retention of the transmembrane domain

The pestivirus Erns glycoprotein interacts with E2 in both infected cells and mature virions

International Nuclear Information System (INIS)

Lazar, Catalin; Zitzmann, Nicole; Dwek, Raymond A.; Branza-Nichita, Norica

2003-01-01

E rns is a pestivirus envelope glycoprotein indispensable for virus attachment and infection of target cells. Unlike the other two envelope proteins E1 and E2, E rns lacks a transmembrane domain and a vast quantity is secreted into the medium of infected cells. The protein is also present in fractions of pure pestivirus virions, raising the important and intriguing question regarding the mechanism of its attachment to the pestivirus envelope. In this study a direct interaction between E rns and E2 glycoproteins was demonstrated in both pestivirus-infected cells and mature virions. By co- and sequential immunoprecipitation we showed that an E rns -E2 heterodimer is assembled very early after translation of the viral polyprotein and before its processing is completed. Our results suggest that E rns is attached to the pestivirus envelope via a direct interaction with E2 and explain the role of E rns in the initial virus-target cell interaction

Glycoprotein hormone α subunit secretion by pituitary adenomas: influence of external irradiation

International Nuclear Information System (INIS)

Macfarlane, I.A.; Beardwell, C.G.; Shalet, S.M.; Darbyshire, P.J.; Hayward, E.; Sutton, M.L.

1980-01-01

In ninety-nine patients with pituitary adenomas, forty-six with acromegaly, the serum level of the glycoprotein hormone α subunit was elevated in eighteen cases. Thirteen of these were acromegalic and one had an FSH-producing tumour. Alpha levels varied little during the day, from one day to the next and over a 6 month period. In twenty-five patients with a variety of other hypothalamic-pituitary disorders examined, one patient with a craniopharyngioma had a mildly elevated α level. External pituitary irradiation was followed by an acute and often transient fall in α level in several of these patients. Of the fifty-four patients with pituitary adenomas who had received external irradiation before testing, only five had elevated α subunit levels compared with thirteen patients of the forty-five who had not been irradiated. This difference in incidence of elevated α level was statistically significant (P<0.025). It is concluded that external irradiation may reduce α subunit level chronically in many patients with pituitary adenoma. (author)

Structure of the membrane anchor of pestivirus glycoprotein E(rns, a long tilted amphipathic helix.

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Daniel Aberle

2014-02-01

Full Text Available E(rns is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns membrane contact, processing and secretion.

Structure of the membrane anchor of pestivirus glycoprotein E(rns), a long tilted amphipathic helix.

Science.gov (United States)

Aberle, Daniel; Muhle-Goll, Claudia; Bürck, Jochen; Wolf, Moritz; Reißer, Sabine; Luy, Burkhard; Wenzel, Wolfgang; Ulrich, Anne S; Meyers, Gregor

2014-02-01

E(rns) is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns) membrane contact, processing and secretion.

Progranulin, a Glycoprotein Deficient in Frontotemporal Dementia, Is a Novel Substrate of Several Protein Disulfide Isomerase Family Proteins

OpenAIRE

Almeida, Sandra; Zhou, Lijuan; Gao, Fen-Biao

2011-01-01

The reduced production or activity of the cysteine-rich glycoprotein progranulin is responsible for about 20% of cases of familial frontotemporal dementia. However, little is known about the molecular mechanisms that govern the level and secretion of progranulin. Here we show that progranulin is expressed in mouse cortical neurons and more prominently in mouse microglia in culture and is abundant in the endoplasmic reticulum (ER) and Golgi. Using chemical crosslinking, immunoprecipitation, an...

Early expression of pregnancy-specific glycoprotein 22 (PSG22) by trophoblast cells modulates angiogenesis in mice.

Science.gov (United States)

Blois, Sandra M; Tirado-González, Irene; Wu, Julie; Barrientos, Gabriela; Johnson, Briana; Warren, James; Freitag, Nancy; Klapp, Burghard F; Irmak, Ster; Ergun, Suleyman; Dveskler, Gabriela S

2012-06-01

Mouse and human pregnancy-specific glycoproteins (PSG) are known to exert immunomodulatory functions during pregnancy by inducing maternal leukocytes to secrete anti-inflammatory cytokines that promote a tolerogenic decidual microenvironment. Many such anti-inflammatory mediators also function as proangiogenic factors, which, along with the reported association of murine PSG with the uterine vasculature, suggest that PSG may contribute to the vascular adaptations necessary for successful implantation and placental development. We observed that PSG22 is strongly expressed around the embryonic crypt on Gestation Day 5.5, indicating that trophoblast giant cells are the main source of PSG22 during the early stages of pregnancy. PSG22 treatment up-regulated the secretion of transforming growth factor beta 1 and vascular endothelial growth factor A (VEGFA) in murine macrophages, uterine dendritic cells, and natural killer cells. A possible role of PSGs in uteroplacental angiogenesis is further supported by the finding that incubation of endothelial cells with PSG22 resulted in the formation of tubes in the presence and absence of VEGFA. We determined that PSG22, like human PSG1 and murine PSG17 and PSG23, binds to the heparan sulfate chains in syndecans. Therefore, our findings indicate that despite the independent evolution and expansion of human and rodent PSG, members in both families have conserved functions that include their ability to induce anti-inflammatory cytokines and proangiogenic factors as well as to induce the formation of capillary structures by endothelial cells. In summary, our results indicate that PSG22, the most abundant PSG expressed during mouse early pregnancy, is likely a major contributor to the establishment of a successful pregnancy.

Proteomic analysis of proteins secreted by the extra-embryonic membranes of the preimplantation sheep conceptus

International Nuclear Information System (INIS)

Lee, R.S.F.

2001-01-01

The extraembryonic membranes (EEM) of the preimplantation sheep conceptus play a major role in the supply of nutrition to the embryo and subsequently participate in the formation of the placentomes. Such functions are likely to be mediated by proteins secreted by the EEM. These proteins may mediate maternal-embryonic interactions or provide the embryo with essential nutrients during the period of early organogenesis and rapid growth and differentiation of the EEM, leading up to implantation. Large format (40 x 40 cm) 2-D gels were used to analyze proteins secreted by the trophoblast, allantois and the yolk sac of day 17 or 18 conceptuses after incubation separately for 3h in the presence of [ 35 S]-methionine. Hundreds of proteins were detected, many of which have not been identified. Each of these EEM secreted different compositions of proteins, as did the two cell layers of the trophoblast. Several proteins that were secreted by the trophectoderm were absent in proteins secreted by the mesoderm layer of the trophoblast. Two of those were identified as interferon-τ and aldose reductase. The proteins secreted by the yolk sac differed markedly from those secreted by the allantois even though both of these membranes were derived from endodermal and mesodermal lineages and are both vascularized. Many of the yolk sac secretory proteins were glycoproteins similar to those found in serum that are normally synthesized by the adult liver; one of these was identified as transferrin. Northern analysis showed that the transferrin mRNA in the yolk sac was even more abundant than it was in adult liver. The similarity between the set of proteins secreted by the yolk sac and those in serum that are attributable to the liver suggests that the yolk sac performs in part, the function of the liver in the synthesis of these proteins. Many proteins secreted by the trophoblast and yolk Sac were detectable in the allantoic fluid even though these membranes were not in contact with the

Restoration of glycoprotein Erns dimerization via pseudoreversion partially restores virulence of classical swine fever virus.

Science.gov (United States)

Tucakov, Anna Katharina; Yavuz, Sabine; Schürmann, Eva-Maria; Mischler, Manjula; Klingebeil, Anne; Meyers, Gregor

2018-01-01

The classical swine fever virus (CSFV) represents one of the most important pathogens of swine. The CSFV glycoprotein E rns is an essential structural protein and an important virulence factor. The latter is dependent on the RNase activity of this envelope protein and, most likely, its secretion from the infected cell. A further important feature with regard to its function as a virulence factor is the formation of disulfide-linked E rns homodimers that are found in virus-infected cells and virions. Mutant CSFV lacking cysteine (Cys) 171, the residue responsible for intermolecular disulfide bond formation, were found to be attenuated in pigs (Tews BA, Schürmann EM, Meyers G. J Virol 2009;83:4823-4834). In the course of an animal experiment with such a dimerization-negative CSFV mutant, viruses were reisolated from pigs that contained a mutation of serine (Ser) 209 to Cys. This mutation restored the ability to form disulphide-linked E rns homodimers. In transient expression studies E rns mutants carrying the S209C change were found to form homodimers with about wt efficiency. Also the secretion level of the mutated proteins was equivalent to that of wt E rns . Virus mutants containing the Cys171Ser/Ser209Cys configuration exhibited wt growth rates and increased virulence when compared with the Cys171Ser mutant. These results provide further support for the connection between CSFV virulence and E rns dimerization.

Recombinant pestivirus E2 glycoproteins prevent viral attachment to permissive and non permissive cells with different efficiency.

Science.gov (United States)

Asfor, A S; Wakeley, P R; Drew, T W; Paton, D J

2014-08-30

Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen, which like other pestiviruses has similar molecular biological features to hepaciviruses, including human Hepatitis C virus. The pestivirus E2 glycoproteins are the major target for virus-neutralising antibodies, as well as playing a role in receptor binding and host range restriction. In this study, recombinant E2 glycoproteins (rE2) derived from three different pestivirus species were examined for their inhibitory effects on pestivirus infectivity in cell culture. Histidine-tagged rE2 glycoproteins of BVDV type 2 strain 178003, BVDV type 1 strain Oregon C24V and CSFV strain Alfort 187 were produced in Spodoptera frugiperda insect cells and purified under native conditions. The ability of rE2 glycoprotein to inhibit the infection of permissive cells by both homologous and heterologous virus was compared, revealing that the inhibitory effects of rE2 glycoproteins correlated with the predicted similarity of the E2 structures in the recombinant protein and the test virus. This result suggests that the sequence and structure of E2 are likely to be involved in the host specificity of pestiviruses at their point of uptake into cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

NARCIS (Netherlands)

Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

2001-01-01

Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects.

Science.gov (United States)

Branco, Luis M; Grove, Jessica N; Moses, Lina M; Goba, Augustine; Fullah, Mohammed; Momoh, Mambu; Schoepp, Randal J; Bausch, Daniel G; Garry, Robert F

2010-11-09

Lassa hemorrhagic fever (LHF) is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV) GP1 (sGP1) in vitro resulting from the expression of the glycoprotein complex (GPC) gene [1, 2]. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV), a filovirus that also causes hemorrhagic fever with nearly 90 percent fatality rates [3 - 5]. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH) Lassa Fever Ward (LFW), in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. It is reasonable to expect that a narrow window exists for detection of sGP1 as the sole

Characterization of a secreted Chlamydia protease

DEFF Research Database (Denmark)

Shaw, A.C.; Vandahl, B.B.; Larsen, M.R.

2002-01-01

Chlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in order...... to promote infection. Effector proteins cannot be identified by motif or similarity searches. As a new strategy for identification of secreted proteins we have compared 2D-PAGE profiles of [35S]-labelled Chlamydia proteins from whole lysates of infected cells to 2D-PAGE profiles of proteins from purified...... Chlamydia. Several secretion candidates from Chlamydia trachomatis D and Chlamydia pneumoniae were detected by this method. Two protein spots were identified among the candidates. These represent fragments of the 'chlamydial protease- or proteasome-like activity factor' (CPAF) and were clearly present in 2D...

A SNX3-dependent retromer pathway mediates retrograde transport of the Wnt sorting receptor Wntless and is required for Wnt secretion

NARCIS (Netherlands)

Harterink, M.; Port, F.; Lorenowicz, M.J.; McGough, I.J.; Silhankova, M.; Betist, M.C.; van Weering, J.R.; van Heesbeen, R.G.; Middelkoop, T.C.; Basler, K.; Cullen, P.J.; Korswagen, H.C.

2011-01-01

Wnt proteins are lipid-modified glycoproteins that play a central role in development, adult tissue homeostasis and disease. Secretion of Wnt proteins is mediated by the Wnt-binding protein Wntless (Wls), which transports Wnt from the Golgi network to the cell surface for release. It has recently

Glycosylation in secreted proteins from yeast Kluyveromyces lactis

Energy Technology Data Exchange (ETDEWEB)

Santos, A.V.; Passos, F.M.L. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Microbiologia. Lab. de Fisiologia de Microrganismos; Azevedo, B.R.; Pimenta, A.M.C.; Santoro, M.M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia. Lab. de Enzimologia e Fisico-Quimica de Proteina

2008-07-01

Full text: The nutritional status of a cell culture affects either the expression or the traffic of a number of proteins. The identification of the physiological conditions which favor protein secretion has important biotechnological consequences in designing systems for recombinant extracellular protein industrial production. Yeast Kluyvromyces lactis has been cultured in a continuous stirring tank bioreactor (CSTR) under nitrogen limitation at growth rates (0.03 h{sup -1} and 0.09 h{sup -1}) close to either exponential or stationary batch growth phases, respectively the objective was to investigate the extracellular glycoproteins at these two level of nitrogen limitation. Proteins from free cell extracts were separated by gradient SDS-PAGE (5-15%) and two-dimensional chromatography, and were analyzed by mass spectrometry (MALDI-TOF-TOF-MS). In SDS-PAGE analysis, differences in extracellular proteome were visualized: different proteins profiles at these two growth rates. The 0.09 h-1 growth rate showed larger number of bands using colloidal Coma ssie Blue staining. Different bands were detected at these two growth rates when the PAS assay for glycoprotein detection in polyacrylamide gel was used. The two-dimensional chromatogram profiles were comparatively distinguished between the 0.03 h{sup -1} and 0.09 h{sup -1} growth rate samples. Protein peaks from the second dimension, were subjected to mass spectrometry. The mass spectrums visualized showed glycosylated proteins with N-acetylglucosamine molecules and 8, 9 or 15 hexoses molecules. Comparisons between the proteins averaged mass values with the deduced proteins masses from K. lactis secreted proteins database indicated possible post-translational modifications, such as post-translational proteolysis, acetylation, deamidation and myristoylation.

Glycosylation in secreted proteins from yeast Kluyveromyces lactis

International Nuclear Information System (INIS)

Santos, A.V.; Passos, F.M.L.; Azevedo, B.R.; Pimenta, A.M.C.; Santoro, M.M.

2008-01-01

Full text: The nutritional status of a cell culture affects either the expression or the traffic of a number of proteins. The identification of the physiological conditions which favor protein secretion has important biotechnological consequences in designing systems for recombinant extracellular protein industrial production. Yeast Kluyvromyces lactis has been cultured in a continuous stirring tank bioreactor (CSTR) under nitrogen limitation at growth rates (0.03 h -1 and 0.09 h -1 ) close to either exponential or stationary batch growth phases, respectively the objective was to investigate the extracellular glycoproteins at these two level of nitrogen limitation. Proteins from free cell extracts were separated by gradient SDS-PAGE (5-15%) and two-dimensional chromatography, and were analyzed by mass spectrometry (MALDI-TOF-TOF-MS). In SDS-PAGE analysis, differences in extracellular proteome were visualized: different proteins profiles at these two growth rates. The 0.09 h-1 growth rate showed larger number of bands using colloidal Coma ssie Blue staining. Different bands were detected at these two growth rates when the PAS assay for glycoprotein detection in polyacrylamide gel was used. The two-dimensional chromatogram profiles were comparatively distinguished between the 0.03 h -1 and 0.09 h -1 growth rate samples. Protein peaks from the second dimension, were subjected to mass spectrometry. The mass spectrums visualized showed glycosylated proteins with N-acetylglucosamine molecules and 8, 9 or 15 hexoses molecules. Comparisons between the proteins averaged mass values with the deduced proteins masses from K. lactis secreted proteins database indicated possible post-translational modifications, such as post-translational proteolysis, acetylation, deamidation and myristoylation

Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary.

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Zhengpin Wang

Full Text Available In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-β (TGF-β family member activin (ACT contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST, during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation.

Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme

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Mustafa Ulutas

2010-01-01

Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.

Salmonella-secreted Virulence Factors

Energy Technology Data Exchange (ETDEWEB)

Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

2011-05-01

In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

Glycoprotein biosynthesis by human normal platelets

International Nuclear Information System (INIS)

Rodriguez, P.; Bello, O.; Apitz-Castro, R.

1987-01-01

Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation

Bile-induced secretion of glucagon-like peptide-1: pathophysiological implications in type 2 diabetes?

DEFF Research Database (Denmark)

Knop, Filip Krag

2010-01-01

During the last decades it has become clear that bile acids not only act as simple fat solubilizers, but additionally represent complex hormonal metabolic integrators. Bile acids activate both nuclear receptors (controlling transcription of genes involved in for example bile acid, cholesterol......, and glucose metabolism) and the cell surface G protein-coupled receptor TGR5 (modulating energy expenditure in brown fat and muscle cells). It has been shown that TGR5 is expressed in enteroendocrine L cells, which secrete the potent glucose-lowering incretin hormone glucagon-like peptide-1 (GLP-1). Recently...

GMP-140 binds to a glycoprotein receptor on human neutrophils: Evidence for a lectin-like interaction

International Nuclear Information System (INIS)

Moore, K.L.; Varki, A.; McEver, R.P.

1991-01-01

GMP-140 is a rapidly inducible receptor for neutrophils and monocytes expressed on activated platelets and endothelial cells. It is a member of the selectin family of lectin-like cell surface molecules that mediate leukocyte adhesion. We used a radioligand binding assay to characterize the interaction of purified GMP-140 with human neutrophils. Unstimulated neutrophils rapidly bound [125I]GMP-140 at 4 degrees C, reaching equilibrium in 10-15 min. Binding was Ca2+ dependent, reversible, and saturable at 3-6 nM free GMP-140 with half-maximal binding at approximately 1.5 nM. Receptor density and apparent affinity were not altered when neutrophils were stimulated with 4 beta-phorbol 12-myristate 13-acetate. Treatment of neutrophils with proteases abolished specific binding of [125I]GMP-140. Binding was also diminished when neutrophils were treated with neuraminidase from Vibrio cholerae, which cleaves alpha 2-3-, alpha 2-6-, and alpha 2-8-linked sialic acids, or from Newcastle disease virus, which cleaves only alpha 2-3- and alpha 2-8-linked sialic acids. Binding was not inhibited by an mAb to the abundant myeloid oligosaccharide, Lex (CD15), or by the neoglycoproteins Lex-BSA and sialyl-Lex-BSA. We conclude that neutrophils constitutively express a glycoprotein receptor for GMP-140, which contains sialic acid residues that are essential for function. These findings support the concept that GMP-140 interacts with leukocytes by a lectin-like mechanism

Huh-7 cell line as an alternative cultural model for the production of human like erythropoietin (EPO

Directory of Open Access Journals (Sweden)

Kausar Humera

2011-11-01

Full Text Available Abstract Background and Aims Erythropoietin (EPO is a glycoprotein hormone which is required to regulate the production of red blood cells. Deficiency of EPO is known to cause anemia in chronically infected renal patients and they require regular blood transfusion. Availability of recombinant EPO has eliminated the need for blood transfusion and now it is extensively used for the treatment of anemia. Glycosylation of erythropoietin is essential for its secretion, stability, protein conformation and biological activity. However, maintenance of human like glycosylation pattern during manufacturing of EPO is a major challenge in biotechnology. Currently, Chinese hamster ovary (CHO cell line is used for the commercial production of erythropoietin but this cell line does not maintain glycosylation resembling human system. With the trend to eliminate non-human constituent from biopharmaceutical products, as a preliminary approach, we have investigated the potential of human hepatoma cell line (Huh-7 to produce recombinant EPO. Materials and methods Initially, the secretory signal and Kozak sequences was added before the EPO mature protein sequence using overlap extension PCR technique. PCR-amplified cDNA fragments of EPO was inserted into mammalian expression vector under the control of the cytomegalovirus (CMV promoter and transiently expressed in CHO and Huh-7 cell lines. After RT-PCR analysis, ELISA and Western blotting was performed to verify the immunochemical properties of secreted EPO. Results Addition of secretory signal and Kozak sequence facilitated the extra-cellular secretion and enhanced the expression of EPO protein. Significant expression (P Conclusion Huh-7 cell line has a great potential to produce glycosylated EPO, suggesting the use of this cell line to produce glycoproteins of the therapeutic importance resembling to the natural human system.

P-glycoprotein Inhibition Increases the Brain Distribution and Antidepressant-Like Activity of Escitalopram in Rodents

OpenAIRE

O'Brien, Fionn E; O'Connor, Richard M; Clarke, Gerard; Dinan, Timothy G; Griffin, Brendan T; Cryan, John F

2013-01-01

Despite the clinical prevalence of the antidepressant escitalopram, over 30% of escitalopram-treated patients fail to respond to treatment. Recent gene association studies have highlighted a potential link between the drug efflux transporter P-glycoprotein (P-gp) and response to escitalopram. The present studies investigated pharmacokinetic and pharmacodynamic interactions between P-gp and escitalopram. In vitro bidirectional transport studies revealed that escitalopram is a transported subst...

Gibberellic Acid-Induced Aleurone Layers Responding to Heat Shock or Tunicamycin Provide Insight into the N-Glycoproteome, Protein Secretion, and Endoplasmic Reticulum Stress

DEFF Research Database (Denmark)

Barba Espin, Gregorio; Dedvisitsakul, Plaipol; Hägglund, Per

2014-01-01

respond to gibberellic acid by secreting an array of proteins and provide a unique system for the analysis of plant protein secretion. Perturbation of protein secretion in gibberellic acid-induced aleurone layers by two independent mechanisms, heat shock and tunicamycin treatment, demonstrated overlapping...... and secretion, such as calreticulin, protein disulfide isomerase, proteasome subunits, and isopentenyl diphosphate isomerase. Sixteen heat shock proteins in 29 spots showed diverse responses to the treatments, with only a minority increasing in response to heat shock. The majority, all of which were small heat...... shock proteins, decreased in heat-shocked aleurone layers. Additionally, glycopeptide enrichment and N-glycosylation analysis identified 73 glycosylation sites in 65 aleurone layer proteins, with 53 of the glycoproteins found in extracellular fractions and 36 found in intracellular fractions...

Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects

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Momoh Mambu

2010-11-01

Full Text Available Abstract Background Lassa hemorrhagic fever (LHF is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV GP1 (sGP1 in vitro resulting from the expression of the glycoprotein complex (GPC gene 12. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV, a filovirus that also causes hemorrhagic fever with nearly 90% fatality rates 345. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH Lassa Fever Ward (LFW, in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. Results It is reasonable to expect that a narrow window exists for

“Would you like to meet the secret Beat?” – Tram Combs and a Beat poetry less celebrated

DEFF Research Database (Denmark)

Sørensen, Bent

of the poetry of Tram Combs, “the secret Beat”, whose 1957 collection Pilgrim’s Terrace contained forewords by both William Carlos Williams and Kenneth Rexroth, and whose collaborators included Allen Ginsberg – yet whose name is persistently left out of the Beat canon. One wonders why, when he is an example...... directly at Gorm, and asked: “Would you like to meet the secret Beat, then?” The old gentleman proceeded to introduce himself as Tram Combs, poet, bookseller, nude model and gay man about town, and for the next few days he took Gorm to art museums, gallery openings and story-telling sessions in his...

Incretin secretion: direct mechanisms

DEFF Research Database (Denmark)

Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich

2014-01-01

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...

Mathematical Modeling of Interacting Glucose-Sensing Mechanisms and Electrical Activity Underlying Glucagon-Like Peptide 1 Secretion.

Directory of Open Access Journals (Sweden)

Michela Riz

2015-12-01

Full Text Available Intestinal L-cells sense glucose and other nutrients, and in response release glucagon-like peptide 1 (GLP-1, peptide YY and other hormones with anti-diabetic and weight-reducing effects. The stimulus-secretion pathway in L-cells is still poorly understood, although it is known that GLP-1 secreting cells use sodium-glucose co-transporters (SGLT and ATP-sensitive K+-channels (K(ATP-channels to sense intestinal glucose levels. Electrical activity then transduces glucose sensing to Ca2+-stimulated exocytosis. This particular glucose-sensing arrangement with glucose triggering both a depolarizing SGLT current as well as leading to closure of the hyperpolarizing K(ATP current is of more general interest for our understanding of glucose-sensing cells. To dissect the interactions of these two glucose-sensing mechanisms, we build a mathematical model of electrical activity underlying GLP-1 secretion. Two sets of model parameters are presented: one set represents primary mouse colonic L-cells; the other set is based on data from the GLP-1 secreting GLUTag cell line. The model is then used to obtain insight into the differences in glucose-sensing between primary L-cells and GLUTag cells. Our results illuminate how the two glucose-sensing mechanisms interact, and suggest that the depolarizing effect of SGLT currents is modulated by K(ATP-channel activity. Based on our simulations, we propose that primary L-cells encode the glucose signal as changes in action potential amplitude, whereas GLUTag cells rely mainly on frequency modulation. The model should be useful for further basic, pharmacological and theoretical investigations of the cellular signals underlying endogenous GLP-1 and peptide YY release.

Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy.

Science.gov (United States)

Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A; Talbot, C Conover; Pytel, Peter; Barton, Elisabeth R; McNally, Elizabeth M; Lee, Se-Jin

2015-10-15

Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf(-/-)) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf(-/-) mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf(-/-) mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf(-/-) mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf(-/-) mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis. © The Author 2015. Published by Oxford University Press.

A predominance of R5-like HIV genotypes in vaginal secretions is associated with elevated plasma HIV-1 RNA levels and the absence of anti-retroviral therapy

Directory of Open Access Journals (Sweden)

Lacour Nedra

2008-07-01

Full Text Available Abstract HIV expressed in genital secretions provides the inoculum from which transmitting variants are selected, both in sexual transmission and mother-to-infant transmission during partuition. Characterization of HIV levels and genotypes found in vaginal secretions and the impact of anti-retroviral therapy (ART on this virus can provide valuable insight for the prevention of HIV transmission. Vaginal HIV was evaluated in a cohort of 43 women attending a New Orleans HIV outpatient clinic. Predominant vaginal genotypes were characterized as R5- or X4-like by heteroduplex tracking analyses of the envelope V3 region. Most women (67.4% shed R5-like genotypes in vaginal secretions which was associated with elevated plasma HIV levels (≥ 10,000 copies HIV-RNA/mL and absence of ART. Because R5-like genotypes are more frequently associated with transmission, these observations suggest that the majority of women shedding HIV in genital secretions present a transmission risk. The levels of vaginal virus were similar between both groups, but shedding of X4-like genotypes was associated with lower plasma viral loads and the use of ART, suggesting that ART use may impact the genotypes of virus found in the female genital compartment.

'Like a Virgin': Hymenoplasty and Secret Marriage in Egypt.

Science.gov (United States)

Wynn, L L

2016-01-01

In Egypt, women seek hymenoplasty to disguise evidence of premarital sexual intercourse. Physicians hide the fact that they perform the procedure, and laypeople condemn it as against religion and morality, a way of cheating men of knowledge of their wives' sexual history. Yet high-ranking religious leaders have condoned hymenoplasty. Based on ethnographic fieldwork, archival research, and formal interviews with laypeople and physicians, in this article, I investigate this discrepancy between religious and lay opinions. Many Egyptians believe women resort to hymenoplasty after contracting secret `urfi (customary) marriages, and I examine the relationship between hymenoplasty and extramarital and paramarital sexuality. Egyptian debates around hymenoplasty and marriage are concerned with the notion that women's sexual status must be socially visible, believing that doctors and kin have the ability and obligation to read women's sexual history through physiological markers and social rituals. Hymenoplasty and secret marriage render women's sexual histories illegible to observers.

Collagen and Stretch Modulate Autocrine Secretion of Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Proteins from Differentiated Skeletal Muscle Cells

Science.gov (United States)

Perrone, Carmen E.; Fenwick-Smith, Daniela; Vandenburgh, Herman H.

1995-01-01

Stretch-induced skeletal muscle growth may involve increased autocrine secretion of insulin-like growth factor-1 (IGF-1) since IGF-1 is a potent growth factor for skeletal muscle hypertrophy, and stretch elevates IGF-1 mRNA levels in vivo. In tissue cultures of differentiated avian pectoralis skeletal muscle cells, nanomolar concentrations of exogenous IGF-1 stimulated growth in mechanically stretched but not static cultures. These cultures released up to 100 pg of endogenously produced IGF-1/micro-g of protein/day, as well as three major IGF binding proteins of 31, 36, and 43 kilodaltons (kDa). IGF-1 was secreted from both myofibers and fibroblasts coexisting in the muscle cultures. Repetitive stretch/relaxation of the differentiated skeletal muscle cells stimulated the acute release of IGF-1 during the first 4 h after initiating mechanical activity, but caused no increase in the long-term secretion over 24-72 h of IGF-1, or its binding proteins. Varying the intensity and frequency of stretch had no effect on the long-term efflux of IGF-1. In contrast to stretch, embedding the differentiated muscle cells in a three-dimensional collagen (Type I) matrix resulted in a 2-5-fold increase in long-term IGF-1 efflux over 24-72 h. Collagen also caused a 2-5-fold increase in the release of the IGF binding proteins. Thus, both the extracellular matrix protein type I collagen and stretch stimulate the autocrine secretion of IGF-1, but with different time kinetics. This endogenously produced growth factor may be important for the growth response of skeletal myofibers to both types of external stimuli.

Glucagon-like peptide-1 7-36 amide and peptide YY from the L-cell of the ileal mucosa are potent inhibitors of vagally induced gastric acid secretion in man

DEFF Research Database (Denmark)

Wettergren, A; Petersen, H; Orskov, C

1994-01-01

BACKGROUND: Glucagon-like peptide (GLP-1) 7-36 amide and peptide YY (PYY) from the L-cell of the ileal mucosa are potent inhibitors of gastric acid secretion in man. It is not clear, however, by which mechanism(s) they inhibit acid secretion. In dogs the inhibitory effect of PYY on acid secretion...

Secretome analysis to elucidate metalloprotease-dependent ectodomain shedding of glycoproteins during neuronal differentiation.

Science.gov (United States)

Tsumagari, Kazuya; Shirakabe, Kyoko; Ogura, Mayu; Sato, Fuminori; Ishihama, Yasushi; Sehara-Fujisawa, Atsuko

2017-02-01

Many membrane proteins are subjected to limited proteolyses at their juxtamembrane regions, processes referred to as ectodomain shedding. Shedding ectodomains of membrane-bound ligands results in activation of downstream signaling pathways, whereas shedding those of cell adhesion molecules causes loss of cell-cell contacts. Secreted proteomics (secretomics) using high-resolution mass spectrometry would be strong tools for both comprehensive identification and quantitative measurement of membrane proteins that undergo ectodomain shedding. In this study, to elucidate the ectodomain shedding events that occur during neuronal differentiation, we establish a strategy for quantitative secretomics of glycoproteins released from differentiating neuroblastoma cells into culture medium with or without GM6001, a broad-spectrum metalloprotease inhibitor. Considering that most of transmembrane and secreted proteins are N-glycosylated, we include a process of N-glycosylated peptides enrichment as well as isotope tagging in our secretomics workflow. Our results show that differentiating N1E-115 neurons secrete numerous glycosylated polypeptides in metalloprotease-dependent manners. They are derived from cell adhesion molecules such as NCAM1, CADM1, L1CAM, various transporters and receptor proteins. These results show the landscape of ectodomain shedding and other secretory events in differentiating neurons and/or during axon elongation, which should help elucidate the mechanism of neurogenesis and the pathogenesis of neurological disorders. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Solubilization of glycoproteins of envelope viruses by detergents

International Nuclear Information System (INIS)

Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

1986-01-01

The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-β-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines

Effect of Omega-3 Polyunsaturated Fatty Acids Supplementation on Body Composition and Circulating Levels of Follistatin-Like 1 in Males With Coronary Artery Disease: A Randomized Double-Blind Clinical Trial.

Science.gov (United States)

Jafari Salim, Shirin; Alizadeh, Shahab; Djalali, Mahmoud; Nematipour, Ebrahim; Hassan Javanbakht, Mohammad

2017-11-01

Adipokines are mediators of body composition and are involved in obesity-related complications such as cardiovascular disease. Omega-3 supplementation has not been studied in the setting of body composition and follistatin-like 1 (FSTL1) levels in patients with coronary artery disease (CAD). This study aimed to investigate the effect of omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on body composition indices and serum levels of FSTL1 in CAD patients. A total of 42 male (aged 45-65 years) subjects with angiographically confirmed CAD were included in this randomized, double-blind, placebo-controlled trial study. The subjects were randomly divided into omega-3 and placebo groups. During the 8-week intervention, the omega-3 group received 1,200 mg of omega-3 daily, while the placebo group received paraffin. Before and after the study, anthropometric measurements and body composition components were taken; serum FSTL1 levels were assessed by an enzyme-linked immunosorbent assay (ELISA) kit. In the omega-3 group, a significant 27.6% increase in serum FSTL1 was seen after 8 weeks of intervention ( p = .001), but no significant difference in posttreatment levels of FSTL1 was observed between the two groups ( p > .05). At the end of the study, a significant decrease in low-density lipoprotein cholesterol (LDL-C; 94.29 ± 22.04 vs. 112.24 ± 24.5; p = .01) and high-sensitivity C-reactive protein (hs-CRP; 1.92 ± 0.79 vs. 3.19 ± 2.51; p = .03) concentration was detected between the two groups. Changes in fasting blood sugar, fasting insulin, body composition, and anthropometric parameters were not significant within and between the groups. Oral omega-3 might increase FSTL1 and decrease LDL-C and hs-CRP concentrations in CAD patients. However, omega-3 supplementation did not have any effect on FSTL1 levels between the groups.

HK2 Proximal Tubule Epithelial Cells Synthesize and Secrete Plasma Proteins Predominantly Through the Apical Surface.

Science.gov (United States)

Zhao, Ke-Wei; Murray, Elsa J Brochmann; Murray, Samuel S

2017-04-01

Renal proximal tubule epithelial cells (PTECs) are known to reabsorb salts and small plasma proteins filtered through Bowman's capsule. Following acute kidney injury, PTECs assume some characteristics of hepatocytes in producing various plasma proteins. We now demonstrate that even at a resting state, a PTEC cell line, HK2 expresses mRNAs for and synthesizes and secretes plasma proteins in a complex with complement C3, an α 2 -macroglobulin family chaperone, including albumin, transferrin, α 1 -antitrypsin, α 1 -antichymotrypsin, α 2 -HS-glycoprotein, ceruloplasmin, haptoglobin, C1-inhibitor, secreted phosphoprotein-24, and insulin-like growth factor-1. When grown on transwell inserts, HK2 cells predominantly secrete (∼90%) plasma proteins into the apical side and a smaller fraction into the basolateral side as determined by ELISA assays. When cultured in the presence of exogenous cytokines such as IL1β, IL6, TNFα, BMP2, or TGFβ1, HK2 cell mRNA expressions for plasma proteins were variably affected whereas basolateral secretions were elevated to or in excess of those of the apical level. In addition, HK2 cells produce proTGFβ1 with its intact N-terminal latency associated peptide and latent-TGF-β-binding proteins. The complex cannot be dissociated under conditions of SDS, heating, and electrophoresis. Moreover, HK2 cells maintain their ability to quickly uptake exogenously added serum proteins from the culture medium, as if they are recognized differently by the endocytic receptors. These results provide new insight into the hepatization of PTECs. In addition to their unique uptake of plasma proteins and salts from the filtrate, they are a source of urinary proteins under normal conditions as wells as in chronic and acute kidney diseases. J. Cell. Biochem. 118: 924-933, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

Energy Technology Data Exchange (ETDEWEB)

Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

1980-01-01

Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

P-glycoprotein Inhibition Increases the Brain Distribution and Antidepressant-Like Activity of Escitalopram in Rodents

Science.gov (United States)

O'Brien, Fionn E; O'Connor, Richard M; Clarke, Gerard; Dinan, Timothy G; Griffin, Brendan T; Cryan, John F

2013-01-01

Despite the clinical prevalence of the antidepressant escitalopram, over 30% of escitalopram-treated patients fail to respond to treatment. Recent gene association studies have highlighted a potential link between the drug efflux transporter P-glycoprotein (P-gp) and response to escitalopram. The present studies investigated pharmacokinetic and pharmacodynamic interactions between P-gp and escitalopram. In vitro bidirectional transport studies revealed that escitalopram is a transported substrate of human P-gp. Microdialysis-based pharmacokinetic studies demonstrated that administration of the P-gp inhibitor cyclosporin A resulted in increased brain levels of escitalopram without altering plasma escitalopram levels in the rat, thereby showing that P-gp restricts escitalopram transport across the blood–brain barrier (BBB) in vivo. The tail suspension test (TST) was carried out to elucidate the pharmacodynamic impact of P-gp inhibition on escitalopram effect in a mouse model of antidepressant activity. Pre-treatment with the P-gp inhibitor verapamil enhanced the response to escitalopram in the TST. Taken together, these data indicate that P-gp may restrict the BBB transport of escitalopram in humans, potentially resulting in subtherapeutic brain concentrations in certain patients. Moreover, by verifying that increasing escitalopram delivery to the brain by P-gp inhibition results in enhanced antidepressant-like activity, we suggest that adjunctive treatment with a P-gp inhibitor may represent a beneficial approach to augment escitalopram therapy in depression. PMID:23670590

Characterization of swiftlet edible bird nest, a mucin glycoprotein, and its adulterants by Raman microspectroscopy.

Science.gov (United States)

Shim, Eric K S; Chandra, Gleen F; Pedireddy, S; Lee, Soo-Y

2016-09-01

Edible bird's nest (EBN) is made from the glutinous salivary secretion of highly concentrated mucin glycoprotein by swiftlets (genus Aerodramus or Collocalia ) native to the Indo-Pacific region. The unique Raman spectrum of EBN has vibrational lines that can be assigned to peptides and saccharides in the glycoprotein, and it can be used to screen for adulteration. The common edible adulterants classified into two types. Type I adulterants, such as fish bladder, pork skin, karaya gum, coralline seaweed, agar strips, and tremella fungus, were solids which adhered externally on the surface of the EBN cement. They can usually be detected with a microscope based on differences in the surface structure. Type II adulterants were water soluble substances such as saccharides (e.g., glucose, sucrose), polypeptides (e.g., hydrolyzed collagen) and salts (e.g. monosodium glutamate) which can be readily soaked up by the EBN hydrogel when moist and adsorbed internally in the EBN cement matrix forming a composite upon drying, making them difficult to detect visually. The present study showed that Raman microspectroscopy offers a rapid, non-invasive, and label free technique to detect both Type I and II adulterants in EBN.

Pseudomonas aeruginosa lipopolysaccharide induces CF-like alteration of protein secretion by human tracheal gland cells.

Science.gov (United States)

Kammouni, W; Figarella, C; Baeza, N; Marchand, S; Merten, M D

1997-12-18

Human tracheal gland (HTG) serous cells are now believed to play a major role in the physiopathology of cystic fibrosis. Because of the persistent inflammation and the specific infection by Pseudomonas aeruginosa in the lung, we looked for the action of the lipopolysaccharide (LPS) of this bacteria on human tracheal gland cells in culture by studying the secretion of the secretory leukocyte proteinase inhibitor (SLPI) which is a specific serous secretory marker of these cells. Treatment with Pseudomonas aeruginosa LPS resulted in a significant dose-dependent increase in the basal production of SLPI (+ 250 +/- 25%) whilst the SLPI transcript mRNA levels remained unchanged. This LPS-induced increase in secretion was inhibited by glucocorticoides. Furthermore, LPS treatment of HTG cells induces a loss of responsiveness to carbachol and isoproterenol but not to adenosine triphosphate. These findings indicate that HTG cells treated by Pseudomonas aeruginosa LPS have the same behavior as those previously observed with CF-HTG cells. Exploration by using reverse transcriptase polymerase chain reaction amplification showed that LPS downregulated cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression in HTG cells indicative of a link between CFTR function and consequent CF-like alteration in protein secretory process.

Glutamine Triggers and Potentiates Glucagon-Like Peptide-1 Secretion by Raising Cytosolic Ca2+ and cAMP

OpenAIRE

Tolhurst, Gwen; Zheng, Yue; Parker, Helen E.; Habib, Abdella M.; Reimann, Frank; Gribble, Fiona M.

2011-01-01

L-glutamine stimulates glucagon-like peptide 1 (GLP-1) secretion in human subjects and cell lines. As recent advances have enabled the study of primary GLP-1–releasing L cells, this study aimed to characterize glutamine-sensing pathways in native murine L cells. L cells were identified using transgenic mice with cell-specific expression of fluorescent markers. Cells were studied in primary colonic cultures from adult mice, or purified by flow cytometry for expression analysis. Intracellular C...

A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors

NARCIS (Netherlands)

Annenkov, A.; Rigby, A.; Amor, S.; Zhou, D.M.; Yousaf, N.; Hemmer, B.; Chernajovsky, Y.

2011-01-01

In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 (IGF1R)

Stimulation of toll-like receptor 2 with bleomycin results in cellular activation and secretion of pro-inflammatory cytokines and chemokines

International Nuclear Information System (INIS)

Razonable, Raymund R.; Henault, Martin; Paya, Carlos V.

2006-01-01

The clinical use of bleomycin results in systemic and pulmonary inflammatory syndromes that are mediated by the production of cytokines and chemokines. In this study, we demonstrate that cell activation is initiated upon the recognition of bleomycin as a pathogen-associated molecular pattern by toll-like receptor (TLR) 2. The THP1 human monocytic cell line, which constitutively expresses high levels of TLR2, secretes interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α during bleomycin exposure. The TLR2-dependent nature of cell activation and cytokine secretion is supported by (1) the inability of TLR2-deficient human embryonic kidney (HEK) 293 cells to exhibit nuclear factor-kappa B (NF-κB) activation and secrete IL-8 in response to bleomycin; (2) the acquired ability of HEK293 to exhibit NF-κB activation and secrete IL-8 upon experimental expression of TLR2; and (3) the inhibition of cell activation in TLR2-expressing HEK293 and THP1 by anti-TLR2 monoclonal antibody. Collectively, these observations identify TLR2 activation as a critical event that triggers NF-κB activation and secretion of cytokines and chemokines during bleomycin exposure. Our in vitro findings could serve as a molecular mechanism underlying the pro-inflammatory toxicity associated with bleomycin. Whether bleomycin engages with other cellular receptors that results in activation of alternate signaling pathways and whether the TLR2-agonist activity of bleomycin contribute to its anti-neoplastic property deserve further study

An improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein

International Nuclear Information System (INIS)

Dawnay, A.B. St. J.; Thornley, C.; Cattell, W.R.

1982-01-01

A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 0 C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance. (author)

Incretin hormone secretion over the day

DEFF Research Database (Denmark)

Ahren, B; Carr, RD; Deacon, Carolyn F.

2010-01-01

The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years. Regulat......The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years....... Regulation of incretin hormone secretion is less well characterized. The main stimulus for incretin hormone secretion is presence of nutrients in the intestinal lumen, and carbohydrate, fat as well as protein all have the capacity to stimulate GIP and GLP-1 secretion. More recently, it has been established...... that a diurnal regulation exists with incretin hormone secretion to an identical meal being greater when the meal is served in the morning compared to in the afternoon. Finally, whether incretin hormone secretion is altered in disease states is an area with, so far, controversial results in different studies...

The glycoprotein of measles virus

International Nuclear Information System (INIS)

Anttonen, O.; Jokinen, M.; Salmi, A.; Vainionpaeae, R.; Gahmberg, C.G.

1980-01-01

Measles virus was propagated in VERO cells and purified from the culture supernatants by two successive tartrate-density-gradient centrifugations. Surface carbohydrates were labelled both in vitro and in vivo with 3 H after treatment with galactose oxidase/NaB 3 H 4 or with [ 3 H]glucosamine. The major labelled glycoprotein in measles virions had a mol.wt. of 79000. After labelling with periodate/NaB 3 H 4 , which would result in specific labelling of sialic acid residues, the 79000-mol.wt. glycoprotein was very weakly labelled. This suggested that there is no or a very low amount of sialic acid in the virions. Further analysis of the glycoprotein showed that galactose is the terminal carbohydrate unit in the oligosaccharide, and the molecular weight of the glycopeptide obtained after Pronase digestion is about 3000. The oligosaccharide is attached to the polypeptide through an alkali-stable bond, indicating a N-glycosidic asparagine linkage. (author)

Secreted and Transmembrane Wnt Inhibitors and Activators

Science.gov (United States)

Cruciat, Cristina-Maria; Niehrs, Christof

2013-01-01

Signaling by the Wnt family of secreted glycoproteins plays important roles in embryonic development and adult homeostasis. Wnt signaling is modulated by a number of evolutionarily conserved inhibitors and activators. Wnt inhibitors belong to small protein families, including sFRP, Dkk, WIF, Wise/SOST, Cerberus, IGFBP, Shisa, Waif1, APCDD1, and Tiki1. Their common feature is to antagonize Wnt signaling by preventing ligand–receptor interactions or Wnt receptor maturation. Conversely, the Wnt activators, R-spondin and Norrin, promote Wnt signaling by binding to Wnt receptors or releasing a Wnt-inhibitory step. With few exceptions, these antagonists and agonists are not pure Wnt modulators, but also affect additional signaling pathways, such as TGF-β and FGF signaling. Here we discuss their interactions with Wnt ligands and Wnt receptors, their role in developmental processes, as well as their implication in disease. PMID:23085770

Distinct activities of Bartonella henselae type IV secretion effector proteins modulate capillary-like sprout formation.

Science.gov (United States)

Scheidegger, F; Ellner, Y; Guye, P; Rhomberg, T A; Weber, H; Augustin, H G; Dehio, C

2009-07-01

The zoonotic pathogen Bartonella henselae (Bh) can lead to vasoproliferative tumour lesions in the skin and inner organs known as bacillary angiomatosis and bacillary peliosis. The knowledge on the molecular and cellular mechanisms involved in this pathogen-triggered angiogenic process is confined by the lack of a suitable animal model and a physiologically relevant cell culture model of angiogenesis. Here we employed a three-dimensional in vitro angiogenesis assay of collagen gel-embedded endothelial cell (EC) spheroids to study the angiogenic properties of Bh. Spheroids generated from Bh-infected ECs displayed a high capacity to form sprouts, which represent capillary-like projections into the collagen gel. The VirB/VirD4 type IV secretion system and a subset of its translocated Bartonella effector proteins (Beps) were found to profoundly modulate this Bh-induced sprouting activity. BepA, known to protect ECs from apoptosis, strongly promoted sprout formation. In contrast, BepG, triggering cytoskeletal rearrangements, potently inhibited sprouting. Hence, the here established in vitro model of Bartonella- induced angiogenesis revealed distinct and opposing activities of type IV secretion system effector proteins, which together with a VirB/VirD4-independent effect may control the angiogenic activity of Bh during chronic infection of the vasculature.

Current Therapies That Modify Glucagon Secretion

DEFF Research Database (Denmark)

Grøndahl, Magnus F.; Keating, Damien J.; Vilsbøll, Tina

2017-01-01

and provide insights into how antidiabetic drugs influence glucagon secretion as well as a perspective on the future of glucagon-targeting drugs. Recent Findings: Several older as well as recent investigations have evaluated the effect of antidiabetic agents on glucagon secretion to understand how glucagon...... may be involved in the drugs’ efficacy and safety profiles. Based on these findings, modulation of glucagon secretion seems to play a hitherto underestimated role in the efficacy and safety of several glucose-lowering drugs. Summary: Numerous drugs currently available to diabetologists are capable...... of altering glucagon secretion: metformin, sulfonylurea compounds, insulin, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors and amylin mimetics. Their diverse effects on glucagon secretion are of importance for their individual efficacy...

Immunization with a dicistronic plasmid expressing a truncated form of bovine herpesvirus-1 glycoprotein D and the amino-terminal subunit of glycoprotein B results in reduced gB-specific immune responses

International Nuclear Information System (INIS)

Manoj, Sharmila; Babiuk, Lorne A.; Drunen Littel van-Hurk, Sylvia van den

2003-01-01

As an approach to create a divalent DNA vaccine, a truncated secreted version of bovine herpesvirus-1 (BHV-1) glycoprotein D (tgD) and the amino-terminal subunit of glycoprotein B (gBb) were expressed from a dicistronic plasmid, designated pSLIAtgD-IRES-gBb. Intradermal immunization of mice with pSLIAtgD-IRES-gBb or a mixture of plasmids encoding tgD (pSLIAtgD) and gBb (pSLIAgBb) by needle injection or gene gun elicited strong tgD-specific immune responses. However, a significant reduction in gBb-specific immune responses was observed upon immunization of mice with pSLIAtgD-IRES-gBb or a mixture of pSLIAtgD and pSLIAgBb in comparison to immunization with pSLIAgBb alone. This reduction in gBb-specific immune responses induced by pSLIAtgD-IRES-gBb was due to production of low amounts of gBb from pSLIAtgD-IRES-gBb, inefficient processing and transport of gBb, and possibly competition for antigen-presenting cells by tgD and gBb. These results indicate that, although divalent plasmids may be used to express different antigens, the efficacy of vaccination with such plasmids may be influenced by the plasmid design and the characteristics of the expressed antigens

Zonal variation in the distribution of an alpha 1-acid glycoprotein glycoform receptor in human adrenal cortex

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1999-01-01

receptor was located in the cytoplasm of glomerulosa and outer fasciculata cells. The intensity of the reaction product decreased in the fasciculata, and no staining was seen in inner fasciculata and reticularis. Inhibition with the simple sugars, mannose and GlcNAc confirmed a lectin-like reaction...... specific receptor. The binding of alpha 1-acid glycoprotein glycoform B and alpha 1-acid glycoprotein glycoform C to the glycoform specific receptor is inhibited by the steroid hormones cortisone, aldosterone, estradiol and progesterone but not by testosterone. The pronounced changes in the distribution...

Genomic and exoproteomic analyses of cold- and alkaline-adapted bacteria reveal an abundance of secreted subtilisin-like proteases.

Science.gov (United States)

Lylloff, Jeanette E; Hansen, Lea B S; Jepsen, Morten; Sanggaard, Kristian W; Vester, Jan K; Enghild, Jan J; Sørensen, Søren J; Stougaard, Peter; Glaring, Mikkel A

2016-03-01

Proteases active at low temperature or high pH are used in many commercial applications, including the detergent, food and feed industries, and bacteria specifically adapted to these conditions are a potential source of novel proteases. Environments combining these two extremes are very rare, but offer the promise of proteases ideally suited to work at both high pH and low temperature. In this report, bacteria from two cold and alkaline environments, the ikaite columns in Greenland and alkaline ponds in the McMurdo Dry Valley region, Antarctica, were screened for extracellular protease activity. Two isolates, Arsukibacterium ikkense from Greenland and a related strain, Arsukibacterium sp. MJ3, from Antarctica, were further characterized with respect to protease production. Genome sequencing identified a range of potential extracellular proteases including a number of putative secreted subtilisins. An extensive liquid chromatography-tandem mass spectrometry analysis of proteins secreted by A. ikkense identified six subtilisin-like proteases as abundant components of the exoproteome in addition to other peptidases potentially involved in complete degradation of extracellular protein. Screening of Arsukibacterium genome libraries in Escherichia coli identified two orthologous secreted subtilisins active at pH 10 and 20 °C, which were also present in the A. ikkense exoproteome. Recombinant production of both proteases confirmed the observed activity. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Changes in the sialylation and sulfation of secreted thyrotropin in congenital hypothyroidism

International Nuclear Information System (INIS)

Gyves, P.W.; Gesundheit, N.; Thotakura, N.R.; Stannard, B.S.; DeCherney, G.S.; Weintraub, B.D.

1990-01-01

The authors have examined the oligosaccharide structure of secreted thyrotropin (TSH) in perinatal and mature rats with congenital primary hypothyroidism. Rat pituitaries from euthyroid control animals and those rendered hypothyroid by methimazole treatment were incubated with [ 3 H]glucosamine in vitro. Secreted TSH was purified, and oligosaccharides were enzymatically released and characterized by anion-exchange HPLC. In perinatal hypothyroid animals compared with control animals, oligosaccharides from TSH α and β subunits contained more species with three or more negative charges. Moreover, perinatal hypothyroid animals demonstrated a dramatic increase in the ratio of sialylated to sulfated species within oligosaccharides of the same negative charge. In mature hypothyroid 9-week-old animals compared with control animals, changes were less pronounced, suggesting that endocrine regulation of oligosaccharide structure is dependent upon the maturational state of the animal. Together, these data provide direct evidence and characterization of specific changes in the structure of a secreted pituitary glycoprotein hormone occurring as a result of in vivo endocrine alterations during early development. Moreover, they provide a potential structural basis to explain the delayed clearance of both TSH and the gonadotropins with end-organ deficiency, which may have important implications for the in vivo biological activities of these hormones

CCL28 induces mucosal homing of HIV-1-specific IgA-secreting plasma cells in mice immunized with HIV-1 virus-like particles.

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Veronica Rainone

Full Text Available Mucosae-associated epithelial chemokine (MEC or CCL28 binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASCs in the mucosal lamina propria. The ability of this chemokine to enhance migration of IgA-ASCs to mucosal sites was assessed in a mouse immunization model using HIV-1(IIIB Virus-like particles (VLPs. Mice receiving either HIV-1(IIIB VLPs alone, CCL28 alone, or the irrelevant CCL19 chemokine were used as controls. Results showed a significantly increased CCR3 and CCR10 expression on CD19(+ splenocytes of HIV-1(IIIB VPL-CCL28-treated mice. HIV-1 Env-specific IFN-γ, IL-4 and IL-5 production, total IgA, anti-Env IgA as well as gastro-intestinal mucosal IgA-secreting plasma cells were also significantly augmented in these mice. Notably, sera and vaginal secretions from HIV-1(IIIB VLP-CCL28-treated mice exhibited an enhanced neutralizing activity against both a HIV-1/B-subtype laboratory strain and a heterologous HIV-1/C-subtype primary isolate. These data suggest that CCL28 could be useful in enhancing the IgA immune response that will likely play a pivotal role in prophylactic HIV vaccines.

Isolation of allergenically active glycoprotein from Prosopis juliflora pollen.

Science.gov (United States)

Thakur, I S

1989-03-01

An allergenically active glycoprotein was homogeneously isolated from the aqueous extract of Prosopis juliflora pollen by ConA-Sepharose affinity chromatography. The molecular weight of this glycoprotein was 20,000 dalton, determined by gel filtration and SDS-PAGE. This fraction showed a total carbohydrate concentration of 25%. The purified glycoprotein revealed immunochemically most antigenic or allergenic and demonstrated homogeneous after reaction with P. juliflora pollen antiserum, characterized by gel diffusion, Immunoelectrophoresis and Radioallergosorbent test.

Bile salts stimulate mucin secretion by cultured dog gallbladder epithelial cells independent of their detergent effect.

Science.gov (United States)

Klinkspoor, J H; Yoshida, T; Lee, S P

1998-05-15

1. Bile salts stimulate mucin secretion by the gallbladder epithelium. We have investigated whether this stimulatory effect is due to a detergent effect of bile salts. 2. The bile salts taurocholic acid (TC) and tauroursodeoxycholic acid (TUDC) and the detergents Triton X-100 (12.5-400 microM) and Tween-20 (0.1-3.2 mM) were applied to monolayers of cultured dog gallbladder epithelial cells. Mucin secretion was studied by measuring the secretion of [3H]N-acetyl-d-glucosamine-labelled glycoproteins. We also attempted to alter the fluidity of the apical membrane of the cells through extraction of cholesterol with beta-cyclodextrin (2.5-15 mM). The effect on TUDC-induced mucin secretion was studied. Cell viability was assessed by measuring lactate dehydrogenase (LDH) leakage or 51Cr release. 3. In contrast with the bile salts, the detergents were not able to cause an increase in mucin secretion without causing concomitant cell lysis. Concentrations of detergent that increased mucin release (>100 microM Triton X-100, >0.8 mM Tween-20), caused increased LDH release. Incubation with beta-cyclodextrin resulted in effective extraction of cholesterol without causing an increase in 51Cr release. However, no effect of the presumed altered membrane fluidity on TUDC (10 mM)-induced mucin secretion was observed. 4. The stimulatory effect of bile salts on mucin secretion by gallbladder epithelial cells is not affected by the fluidity of the apical membrane of the cells and also cannot be mimicked by other detergents. We conclude that the ability of bile salts to cause mucin secretion by the gallbladder epithelium is not determined by their detergent properties.

Antiphospholipid antibody-induced miR-146a-3p drives trophoblast interleukin-8 secretion through activation of Toll-like receptor 8.

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Gysler, Stefan M; Mulla, Melissa J; Guerra, Marta; Brosens, Jan J; Salmon, Jane E; Chamley, Lawrence W; Abrahams, Vikki M

2016-07-01

What is the role of microRNAs (miRs) in antiphospholipid antibody (aPL)-induced trophoblast inflammation? aPL-induced up-regulation of trophoblast miR-146a-3p is mediated by Toll-like receptor 4 (TLR4), and miR-146a-3p in turn drives the cells to secrete interleukin (IL)-8 by activating the RNA sensor, TLR8. Obstetric antiphospholipid syndrome (APS) is an autoimmune disorder characterized by circulating aPL and an increased risk of pregnancy complications. We previously showed that aPL recognizing beta2 glycoprotein I (β2GPI) elicit human first trimester trophoblast secretion of IL-8 by activating TLR4. Since some miRs control TLR responses, their regulation in trophoblast cells by aPL and functional role in the aPL-mediated inflammatory response was investigated. miRs can be released from cells via exosomes, and therefore, miR exosome expression was also examined. A panel of miRs was selected based on their involvement with TLR signaling: miR-9; miR-146a-5p and its isomiR, miR-146a-3p; miR-155, miR-210; and Let-7c. Since certain miRs can activate the RNA sensor, TLR8, this was also investigated. For in vitro studies, the human first trimester extravillous trophoblast cell line, HTR8 was studied. HTR8 cells transfected to express a TLR8 dominant negative (DN) were also used. Plasma was evaluated from pregnant women who have aPL, either with or without systemic lupus erythematous (SLE) (n = 39); SLE patients without aPL (n = 30); and healthy pregnant controls (n = 20). Trophoblast HTR8 wildtype and TLR8-DN cells were incubated with or without aPL (mouse anti-human β2GPI mAb) for 48-72 h. HTR8 cells were also treated with or without aPL in the presence and the absence of a TLR4 antagonist (lipopolysaccharide from Rhodobacter sphaeroides; LPS-RS), specific miR inhibitors or specific miR mimics. miR expression levels in trophoblast cells, trophoblast-derived exosomes and exosomes isolated from patient plasma were measured by qPCR. Trophoblast IL-8 secretion was

Analysis of glycoprotein-derived oligosaccharides in glycoproteins detected on two-dimensional gel by capillary electrophoresis using on-line concentration method.

Science.gov (United States)

Kamoda, Satoru; Nakanishi, Yasuharu; Kinoshita, Mitsuhiro; Ishikawa, Rika; Kakehi, Kazuaki

2006-02-17

Capillary electrophoresis (CE) is an effective tool to analyze carbohydrate mixture derived from glycoproteins with high resolution. However, CE has a disadvantage that a few nanoliters of a sample solution are injected to a narrow capillary. Therefore, we have to prepare a sample solution of high concentration for CE analysis. In the present study, we applied head column field-amplified sample stacking method to the analysis of N-linked oligosaccharides derived from glycoprotein separated by two-dimensional gel electrophoresis. Model studies demonstrated that we achieved 60-360 times concentration effect on the analysis of carbohydrate chains labeled with 3-aminobenzoic acid (3-AA). The method was applied to the analysis of N-linked oligosaccharides from glycoproteins separated and detected on PAGE gel. Heterogeneity of alpha1-acid glycoprotein (AGP), i.e. glycoforms, was examined by 2D-PAGE and N-linked oligosaccharides were released by in-gel digestion with PNGase F. The released oligosaccharides were derivatized with 3-AA and analyzed by CE. The results showed that glycoforms having lower pI values contained a larger amount of tetra- and tri-antennary oligosaccharides. In contrast, glycoforms having higher pI values contained bi-antennary oligosaccharides abundantly. The result clearly indicated that the spot of a glycoprotein glycoform detected by Coomassie brilliant blue staining on 2D-PAGE gel is sufficient for quantitative profiling of oligosaccharides.

Determination of P-Glycoprotein Expression by Flow Cytometry in Hematological Malignancies

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Berkay Saraymen

2016-03-01

Full Text Available Objective: Determination the expression of P-glycoprotein is especially problematic for normal tissues because immuno­logical methods are limited in terms of sensitivity. We aimed to determine the expression of P-glycoprotein and CD34 by flow cytometry, and to evaluate the level of expression of P-glycoprotein and CD34 with unresponsive to treatment in pa­tients diagnosed with hematologic malignancy. Methods: Our study included fifty patients diagnosed with acute myeloblastic leukemia and acute lymphoblastic leuke­mia, and twenty healthy controls who were admitted to Erci­yes University Hematology-Oncology Hospital. The suspend­ed cells from bone marrow samples of patients and the pe­ripheral blood samples of healthy people were marked with P-glycoprotein phycoerythrin and CD34 FITC or PerCP Cy 5.5; and then surface expression was measured by means of flow cytometry. Results: In 6 of 30 acute myeloblastic leukemia patients P-glycoprotein and CD34 expression, in 6 of 20 acute lympho­blastic leukemia patients P-glycoprotein, in 5 of them CD34 expression were determined. A significant relation between P-glycoprotein and CD34 expressions in acute myeloblas­tic leukemia and acute lymphoblastic leukemia bone marrow samples was reported. Conclusion: Our data indicate that flow cytometry is more reliable, precise and faster than molecular methods for mea­suring P-glycoprotein expression and suggests the pos­sibility of a significant relationship between P-glycoprotein and CD34 expressions in acute myeloblastic leukemia and acute lymphoblastic leukemia bone marrow samples. The blast cells expressing CD34 on their surface along with P-glycoprotein simultaneously show that multi drug resistance 1 gene is mostly active in immature cells.

Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity

DEFF Research Database (Denmark)

Horvat, B; Multhaupt, H A; Damjanov, I

1993-01-01

We used lectin overlay blotting and SDS-PAGE to analyze the estrous cycle-specific expression of mouse vaginal epithelial glycoproteins. Seven lectins chosen for their differential carbohydrate-binding specificity revealed 15 glycoproteins that showed cycle-related expression. Each lectin had...... in proestrus, coincident with the transformation of two superficial layers of vaginal squamous epithelium into mucinous cuboidal cells. Electron microscopic lectin histochemistry revealed the glycoproteins in the mucinous granules of surface cuboidal cells and in the lumen of the vagina. Our results illustrate...... the complexity of glycoconjugate synthesis in mouse vagina and reveal the distinct cycle-specific patterns of individual glycoprotein expression. These cyclic glycoproteins could serve as vaginal biochemical markers for the specific phases of the estrous cycle....

Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA

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Menzel Diedrik

2011-02-01

Full Text Available Abstract Background Hydroxyproline rich glycoproteins (HRGPs are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis, and by immunomodulation with the JIM11 antibody. Results Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs, mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs, proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM. This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP

Three-Dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation.

Science.gov (United States)

Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W Andy

2016-11-30

Glycoproteins have vast structural diversity that plays an important role in many biological processes and have great potential as disease biomarkers. Here, we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase glycoprotein array (polyGPA), to capture and profile glycoproteomes specifically, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture preoxidized glycans on glycoproteins from complex protein samples such as biofluids. The captured glycoproteins were subsequently detected using the same validated antibodies as in RPPA. We demonstrated the outstanding specificity, sensitivity, and quantitative capabilities of polyGPA by capturing and detecting purified as well as endogenous α-1-acid glycoprotein (AGP) in human plasma. We further applied quantitative N-glycoproteomics and the strategy to validate a panel of glycoproteins identified as potential biomarkers for bladder cancer by analyzing urine glycoproteins from bladder cancer patients or matched healthy individuals.

Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

Science.gov (United States)

Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

2017-01-01

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.

Regulation of glucagon secretion by incretins

DEFF Research Database (Denmark)

Holst, Jens Juul; Christensen, M; Lund, A

2011-01-01

Glucagon secretion plays an essential role in the regulation of hepatic glucose production, and elevated fasting and postprandial plasma glucagon concentrations in patients with type 2 diabetes (T2DM) contribute to their hyperglycaemia. The reason for the hyperglucagonaemia is unclear, but recent...... studies have shown lack of suppression after oral but preserved suppression after isoglycaemic intravenous glucose, pointing to factors from the gut. Gastrointestinal hormones that are secreted in response to oral glucose include glucagon-like peptide-1 (GLP-1) that strongly inhibits glucagon secretion......, and GLP-2 and GIP, both of which stimulate secretion. When the three hormones are given together on top of isoglycaemic intravenous glucose, glucagon suppression is delayed in a manner similar to that observed after oral glucose. Studies with the GLP-1 receptor antagonist, exendin 9-39, suggest...

Developing baculovirus-insect cell expression systems for humanized recombinant glycoprotein production

International Nuclear Information System (INIS)

Jarvis, Donald L.

2003-01-01

The baculovirus-insect cell expression system is widely used to produce recombinant glycoproteins for many different biomedical applications. However, due to the fundamental nature of insect glycoprotein processing pathways, this system is typically unable to produce recombinant mammalian glycoproteins with authentic oligosaccharide side chains. This minireview summarizes our current understanding of insect protein glycosylation pathways and our recent efforts to address this problem. These efforts have yielded new insect cell lines and baculoviral vectors that can produce recombinant glycoproteins with humanized oligosaccharide side chains

Mining the O-mannose glycoproteome reveals cadherins as major O-mannosylated glycoproteins

DEFF Research Database (Denmark)

Vester-Christensen, Malene B; Halim, Adnan; Joshi, Hiren Jitendra

2013-01-01

The metazoan O-mannose (O-Man) glycoproteome is largely unknown. It has been shown that up to 30% of brain O-glycans are of the O-Man type, but essentially only alpha-dystroglycan (α-DG) of the dystrophin-glycoprotein complex is well characterized as an O-Man glycoprotein. Defects in O-Man...... glycosylation underlie congenital muscular dystrophies and considerable efforts have been devoted to explore this O-glycoproteome without much success. Here, we used our SimpleCell strategy using nuclease-mediated gene editing of a human cell line (MDA-MB-231) to reduce the structural heterogeneity of O-Man...... glycans and to probe the O-Man glycoproteome. In this breast cancer cell line we found that O-Man glycosylation is primarily found on cadherins and plexins on β-strands in extracellular cadherin and Ig-like, plexin and transcription factor domains. The positions and evolutionary conservation of O-Man...

Encoding asymmetry of the N-glycosylation motif facilitates glycoprotein evolution.

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Ryan Williams

Full Text Available Protein N-glycosylation is found in all domains of life and has a conserved role in glycoprotein folding and stability. In animals, glycoproteins transit through the Golgi where the N-glycans are trimmed and rebuilt with sequences that bind lectins, an innovation that greatly increases structural diversity and redundancy of glycoprotein-lectin interaction at the cell surface. Here we ask whether the natural tension between increasing diversity (glycan-protein interactions and site multiplicity (backup and status quo might be revealed by a phylogenic examination of glycoproteins and NXS/T(X ≠ P N-glycosylation sites. Site loss is more likely by mutation at Asn encoded by two adenosine (A-rich codons, while site gain is more probable by generating Ser or Thr downstream of an existing Asn. Thus mutations produce sites at novel positions more frequently than the reversal of recently lost sites, and therefore more paths though sequence space are made available to natural selection. An intra-species comparison of secretory and cytosolic proteins revealed a departure from equilibrium in sequences one-mutation-away from NXS/T and in (A content, indicating strong selective pressures and exploration of N-glycosylation positions during vertebrate evolution. Furthermore, secretory proteins have evolved at rates proportional to N-glycosylation site number, indicating adaptive interactions between the N-glycans and underlying protein. Given the topology of the genetic code, mutation of (A is more often nonsynonomous, and Lys, another target of many PTMs, is also encoded by two (A-rich codons. An examination of acetyl-Lys sites in proteins indicated similar evolutionary dynamics, consistent with asymmetry of the target and recognition portions of modified sites. Our results suggest that encoding asymmetry is an ancient mechanism of evolvability that increases diversity and experimentation with PTM site positions. Strong selective pressures on PTMs may have

Regulation of glycoprotein synthesis in yeast by mating pheromones

International Nuclear Information System (INIS)

Tanner, W.

1984-01-01

In Saccharomyces cerevisiae, glycosylated proteins amount to less than 2% of the cell protein. Two intensively studied examples of yeast glycoproteins are the external cell wall - associated invertase and the vacuolar carboxypeptidase Y. Recently, it was shown that the mating pheromone, alpha factor, specifically and strongly inhibits the synthesis of N-glycosylated proteins in haploid a cells, whereas O-glycosylated proteins are not affected. In this paper, the pathways of glycoprotein biosynthesis are summarized briefly, and evidence is presented that mating pheomones have a regulatory function in glycoprotein synthesis

Engineered CHO cells for production of diverse, homogeneous glycoproteins

DEFF Research Database (Denmark)

Yang, Zhang; Wang, Shengjun; Halim, Adnan

2015-01-01

Production of glycoprotein therapeutics in Chinese hamster ovary (CHO) cells is limited by the cells' generic capacity for N-glycosylation, and production of glycoproteins with desirable homogeneous glycoforms remains a challenge. We conducted a comprehensive knockout screen of glycosyltransferas...

Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

African Journals Online (AJOL)

The E glycoprotein of dengue virus is responsible for the viral binding to the receptor. The crystal structure of envelope glycoprotein has already been determined. However, where the well-defined Bcell and T-cell epitopes are located is still a question. Because of the large variations among the four dengue genotypes, it is ...

The Purification of a Blood Group A Glycoprotein: An Affinity Chromatography Experiment.

Science.gov (United States)

Estelrich, J.; Pouplana, R.

1988-01-01

Describes a purification process through affinity chromatography necessary to obtain specific blood group glycoproteins from erythrocytic membranes. Discusses the preparation of erythrocytic membranes, extraction of glycoprotein from membranes, affinity chromatography purification, determination of glycoproteins, and results. (CW)

Toll-like receptor triggered dendritic cell maturation and IL-12 secretion are necessary to overcome T-cell inhibition by glioma-associated TGF-beta2.

NARCIS (Netherlands)

Grauer, O.M.; Poschl, P.; Lohmeier, A.; Adema, G.J.; Bogdahn, U.

2007-01-01

Malignant gliomas are able to secrete large amounts of immunosuppressive cytokines like transforming growth factor beta 2 (TGF-beta2) and regularly escape from immune surveillance. Many strategies have been developed to induce potent anti-glioma responses, among those the use of dendritic cells (DC)

The First Scube3 Mutant Mouse Line with Pleiotropic Phenotypic Alterations

DEFF Research Database (Denmark)

Fuchs, Helmut; Sabrautzki, Sibylle; Przemeck, Gerhard K H

2016-01-01

The vertebrate Scube (Signal peptide, CUB, and EGF-like domain-containing protein) family consists of three independent members, Scube1-3, which encode secreted cell surface-associated membrane glycoproteins. Limited information about the general function of this gene family is available, and the...

Isolation and characterization of two antigenic glycoproteins from the pollen of Prosopis juliflora.

Science.gov (United States)

Thakur, I S

1991-03-01

Two antigenically active glycoprotein fractions were isolated from crude extract of the pollen of Prosopis juliflora using DEAE-cellulose ion exchange chromatography. The glycoproteins gave single band on polyacrylamide gel electrophoresis. The molecular weight of these two glycoprotein was 20,000 and 10,000 as determined by gel filtration on Sephadex G-75. With the help of crossed immunoelectrophoresis and gel diffusion crude extract exhibited twelve and three precipitating antigens suggesting its heterogeneous nature; and the purified glycoprotein fractions however formed single precipitin band on gel diffusion test and immunoelectrophoresis. As tested by ELISA the polyclonal antisera raised in rabbit showed strong binding affinity with glycoprotein of MW 20,000. These result indicates that the two glycoprotein fractions are not antigenically identical.

Gene structure of the pregnancy-associated glycoprotein-like (PAG-L) in the Eurasian beaver (Castor fiber L.).

Science.gov (United States)

Lipka, Aleksandra; Majewska, Marta; Panasiewicz, Grzegorz; Bieniek-Kobuszewska, Martyna; Szafranska, Bozena

2017-09-01

The pregnancy-associated glycoprotein-like family (PAG-L) is a large group of chorionic products, expressed in the pre-placental trophoblast and later in the post-implantational chorionic epithelium, and are involved in proper placenta development and embryo-maternal interaction in eutherians. This study describes identification of the PAG-L family in the genome of the Eurasian beaver (Castor fiber L.), named CfPAG-L. We identified 7657 bp of the CfPAG-L gDNA sequence (Acc. No. KX377932), encompassing nine exons (1-9) and eight introns (A-H). The length of the CfPAG-L exons (59-200 bp) was equivalently similar to the only known counterparts of bPAG1, bPAG2, and pPAG2. The length of the CfPAG-L introns ranged 288-1937 bp and was completely different from previously known PAG introns. The exonic CfPAG-L regions revealed 50.3-72.9% homology with equivalent segments of bPAG1 and pPAG2 structure. The intronic CfPAG-L regions alignments revealed a lack of homology. Within the entire CfPAG-L gene, 31 potential single nucleotide variants (SNV: 7 transversions and 24 transitions) were predicted. The identified exonic polymorphic loci did not affect the amino acid sequence of the CfPAG-L polypeptide precursor. This is the first report describing the CfPAG-L gene sequence, structural organization, and SNVs in the Eurasian beaver, one of the largest rodents.

Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

International Nuclear Information System (INIS)

Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

1983-01-01

Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP (platelet-rich plasma). Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. Results obtained by the two methods were compared using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI 2 (prostacyclin) or PGE 1 (prostaglandin E 1 ) was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP

Purification and characterization of the glycoprotein allergen from Prosopis juliflora pollen.

Science.gov (United States)

Thakur, I S

1991-02-01

Highly active glycoprotein allergens have been isolated from pollen of Prosopis juliflora by a combination of Sephadex G-100 gel filtration and Sodium dodecyl sulphate-Poly-acrylamide gel electrophoresis. The glycoprotein fraction was homogeneous, and had molecular weight 20,000. The purified glycoprotein allergen contained 20% carbohydrate, mainly arabinose and galactose. Enzymatic digestion of glycoprotein with protease released glycopeptides of molecular weight ranging from less than 1,000 to more than 5,000 on Sephadex G-25 gel filtration. Antigenicity or allergenicity testing of these glycopeptides by immunodiffusion, immunoelectrophoresis, and radioallergosorbent test indicated complete loss of allergenic activity after digestion with protease whereas incubation with beta-D-galactosidase and periodate oxidation had little affect on the allergenic activity of the glycoprotein fraction. But incubation with alpha-D-glucosidase did not affect the allergenic activity significantly. All these tests indicated that protein played significant role in allergenicity of P. juliflora pollen.

Strategies to overcome or circumvent P-glycoprotein mediated multidrug resistance.

Science.gov (United States)

Yuan, Hongyu; Li, Xun; Wu, Jifeng; Li, Jinpei; Qu, Xianjun; Xu, Wenfang; Tang, Wei

2008-01-01

Cancer patients who receive chemotherapy often experience intrinsic or acquired resistance to a broad spectrum of chemotherapeutic agents. The phenomenon, termed multidrug resistance (MDR), is often associated with the over-expression of P-glycoprotein, a transmembrane protein pump, which can enhance efflux of a various chemicals structurally unrelated at the expense of ATP depletion, resulting in decrease of the intracellular cytotoxic drug accumulation. The MDR has been a big threaten to the human health and the war fight for it continues. Although several other mechanisms for MDR are elucidated in recent years, considerable efforts attempting to inverse MDR are involved in exploring P-glycoprotein modulators and suppressing P-glycoprotein expression. In this review, we will report on the recent advances in various strategies for overcoming or circumventing MDR mediated by P-glycoprotein.

Inhibition of collagen production in scleroderma fibroblast cultures by a connective tissue glycoprotein extracted from normal dermis

International Nuclear Information System (INIS)

Maquart, F.X.; Bellon, G.; Cornillet-Stoupy, J.; Randoux, A.; Triller, R.; Kalis, B.; Borel, J.P.

1985-01-01

It was shown in a previous paper that a connective tissue glycoprotein (CTGP) extracted from normal rabbit dermis was able to inhibit total protein and collagen syntheses by normal dermis fibroblast cultures. In the present study, the effects of CTGP on scleroderma fibroblasts were investigated. [ 14 C]Proline incorporation into total proteins of the supernatant was not significantly different from that found in controls. By contrast, the amount of collagen, expressed as percentage of total secreted protein, was far higher in scleroderma cultures than in normal ones (14.4% +/- 6.0% vs 4.6% +/- 0.9%). Addition of CTGP to the medium induced a concentration-dependent inhibition of [ 14 C]proline incorporation into proteins from both control and scleroderma cells. In control cultures, no significant decrease of the percentage of collagen was observed, but over 60 micrograms/ml, both cytotoxic effects and inhibition of protein synthesis occurred. In scleroderma cultures, the inhibition was twice as effective on collagen as on noncollagen protein synthesis. The inhibition of collagen secretion was not related either to changes in collagen hydroxylation or to the intracellular catabolism of newly synthesized procollagen

A novel function of N-linked glycoproteins, alpha-2-HS-glycoprotein and hemopexin: Implications for small molecule compound-mediated neuroprotection.

Directory of Open Access Journals (Sweden)

Takuya Kanno

Full Text Available Therapeutic agents to the central nervous system (CNS need to be efficiently delivered to the target site of action at appropriate therapeutic levels. However, a limited number of effective drugs for the treatment of neurological diseases has been developed thus far. Further, the pharmacological mechanisms by which such therapeutic agents can protect neurons from cell death have not been fully understood. We have previously reported the novel small-molecule compound, 2-[mesityl(methylamino]-N-[4-(pyridin-2-yl-1H-imidazol-2-yl] acetamide trihydrochloride (WN1316, as a unique neuroprotectant against oxidative injury and a highly promising remedy for the treatment of amyotrophic lateral sclerosis (ALS. One of the remarkable characteristics of WN1316 is that its efficacious doses in ALS mouse models are much less than those against oxidative injury in cultured human neuronal cells. It is also noted that the WN1316 cytoprotective activity observed in cultured cells is totally dependent upon the addition of fetal bovine serum in culture medium. These findings led us to postulate some serum factors being tightly linked to the WN1316 efficacy. In this study, we sieved through fetal bovine serum proteins and identified two N-linked glycoproteins, alpha-2-HS-glycoprotein (AHSG and hemopexin (HPX, requisites to exert the WN1316 cytoprotective activity against oxidative injury in neuronal cells in vitro. Notably, the removal of glycan chains from these molecules did not affect the WN1316 cytoprotective activity. Thus, two glycoproteins, AHSG and HPX, represent a pivotal glycoprotein of the cytoprotective activity for WN1316, showing a concrete evidence for the novel glycan-independent function of serum glycoproteins in neuroprotective drug efficacy.

A Functional Henipavirus Envelope Glycoprotein Pseudotyped Lentivirus Assay System

Directory of Open Access Journals (Sweden)

Broder Christopher C

2010-11-01

Full Text Available Abstract Background Hendra virus (HeV and Nipah virus (NiV are newly emerged zoonotic paramyxoviruses discovered during outbreaks in Queensland, Australia in 1994 and peninsular Malaysia in 1998/9 respectively and classified within the new Henipavirus genus. Both viruses can infect a broad range of mammalian species causing severe and often-lethal disease in humans and animals, and repeated outbreaks continue to occur. Extensive laboratory studies on the host cell infection stage of HeV and NiV and the roles of their envelope glycoproteins have been hampered by their highly pathogenic nature and restriction to biosafety level-4 (BSL-4 containment. To circumvent this problem, we have developed a henipavirus envelope glycoprotein pseudotyped lentivirus assay system using either a luciferase gene or green fluorescent protein (GFP gene encoding human immunodeficiency virus type-1 (HIV-1 genome in conjunction with the HeV and NiV fusion (F and attachment (G glycoproteins. Results Functional retrovirus particles pseudotyped with henipavirus F and G glycoproteins displayed proper target cell tropism and entry and infection was dependent on the presence of the HeV and NiV receptors ephrinB2 or B3 on target cells. The functional specificity of the assay was confirmed by the lack of reporter-gene signals when particles bearing either only the F or only G glycoprotein were prepared and assayed. Virus entry could be specifically blocked when infection was carried out in the presence of a fusion inhibiting C-terminal heptad (HR-2 peptide, a well-characterized, cross-reactive, neutralizing human mAb specific for the henipavirus G glycoprotein, and soluble ephrinB2 and B3 receptors. In addition, the utility of the assay was also demonstrated by an examination of the influence of the cytoplasmic tail of F in its fusion activity and incorporation into pseudotyped virus particles by generating and testing a panel of truncation mutants of NiV and HeV F

Human decidua-derived mesenchymal stem cells differentiate into functional alveolar type II-like cells that synthesize and secrete pulmonary surfactant complexes.

Directory of Open Access Journals (Sweden)

Alejandro Cerrada

Full Text Available Lung alveolar type II (ATII cells are specialized in the synthesis and secretion of pulmonary surfactant, a lipid-protein complex that reduces surface tension to minimize the work of breathing. Surfactant synthesis, assembly and secretion are closely regulated and its impairment is associated with severe respiratory disorders. At present, well-established ATII cell culture models are not available. In this work, Decidua-derived Mesenchymal Stem Cells (DMSCs have been differentiated into Alveolar Type II- Like Cells (ATII-LCs, which display membranous cytoplasmic organelles resembling lamellar bodies, the organelles involved in surfactant storage and secretion by native ATII cells, and accumulate disaturated phospholipid species, a surfactant hallmark. Expression of characteristic ATII cells markers was demonstrated in ATII-LCs at gene and protein level. Mimicking the response of ATII cells to secretagogues, ATII-LCs were able to exocytose lipid-rich assemblies, which displayed highly surface active capabilities, including faster interfacial adsorption kinetics than standard native surfactant, even in the presence of inhibitory agents. ATII-LCs could constitute a highly useful ex vivo model for the study of surfactant biogenesis and the mechanisms involved in protein processing and lipid trafficking, as well as the packing and storage of surfactant complexes.

Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

Directory of Open Access Journals (Sweden)

Evan L Pannkuk

Full Text Available White nose syndrome (WNS is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1 was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE, broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

Science.gov (United States)

Pannkuk, Evan L; Risch, Thomas S; Savary, Brett J

2015-01-01

White nose syndrome (WNS) is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1) was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE), broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

Labelled antibody techniques in glycoprotein estimation

International Nuclear Information System (INIS)

Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

1977-01-01

The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

The stylar 120 kDa glycoprotein is required for S-specific pollen rejection in Nicotiana.

Science.gov (United States)

Hancock, C Nathan; Kent, Lia; McClure, Bruce A

2005-09-01

S-RNase participates in at least three mechanisms of pollen rejection. It functions in S-specific pollen rejection (self-incompatibility) and in at least two distinct interspecific mechanisms of pollen rejection in Nicotiana. S-specific pollen rejection and rejection of pollen from Nicotiana plumbaginifolia also require additional stylar proteins. Transmitting-tract-specific (TTS) protein, 120 kDa glycoprotein (120K) and pistil extensin-like protein III (PELP III) are stylar glycoproteins that bind S-RNase in vitro and are also known to interact with pollen. Here we tested whether these glycoproteins have a direct role in pollen rejection. 120K shows the most polymorphism in size between Nicotiana species. Larger 120K-like proteins are often correlated with S-specific pollen rejection. Sequencing results suggest that the polymorphism primarily reflects differences in glycosylation, although indels also occur in the predicted polypeptides. Using RNA interference (RNAi), we suppressed expression of 120K to determine if it is required for S-specific pollen rejection. Transgenic SC N. plumbaginifolia x SI Nicotiana alata (S105S105 or SC10SC10) hybrids with no detectable 120K were unable to perform S-specific pollen rejection. Thus, 120K has a direct role in S-specific pollen rejection. However, suppression of 120K had no effect on rejection of N. plumbaginifolia pollen. In contrast, suppression of HT-B, a factor previously implicated in S-specific pollen rejection, disrupts rejection of N. plumbaginifolia pollen. Thus, S-specific pollen rejection and rejection of N. plumbaginifolia pollen are mechanistically distinct, because they require different non-S-RNase factors.

Pathophysiology of glucagon secretion

International Nuclear Information System (INIS)

Boettger, J.; Pabst, H.W.

1980-01-01

Pathophysiology of glucagon secretion is reviewed in brief separating hyperglucagonemic from hypoclucagonemic states. Many questions concerning the role of glucagon in diabetes mellitus and in other diseases are still unresolved. The clucagon RIA is of clinical significance in a few diseases like glucagonoma, which may present without symptoms of the 'glucagonoma syndrome', the probably very rare hyperglucagonemia and some of the spontaneous hypoglycemias. Glucagon secretion may be evaluated by the determination of fasting immunoreactive glucagon (IRG) and by appropriate function tests as stimulation with i.v. arginine and suppression with oral glucose. However, the glucagon RIA at present is not a routine method, although commercial kits are available. Many pitfalls of radioimmunological glucagon determination still exist. (orig.) [de

On the connective tissue regulator Follistatin-like 1

NARCIS (Netherlands)

Sylva, M.

2014-01-01

Even though for many years the molecular mechanisms underlying cardiac development have been studied, the majority of cardiac defects remain unexplained. Defects in the cardiac connective tissue component result in a large proportion of heart defects such as valve and septal defects. Previous

Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters.

Science.gov (United States)

Wang, Fun-In; Deng, Ming-Chung; Huang, Yu-Liang; Chang, Chia-Yi

2015-06-29

Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase) activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

Quantitative proteomic analysis for high-throughput screening of differential glycoproteins in hepatocellular carcinoma serum

International Nuclear Information System (INIS)

Gao, Hua-Jun; Chen, Ya-Jing; Zuo, Duo; Xiao, Ming-Ming; Li, Ying; Guo, Hua; Zhang, Ning; Chen, Rui-Bing

2015-01-01

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths. Novel serum biomarkers are required to increase the sensitivity and specificity of serum screening for early HCC diagnosis. This study employed a quantitative proteomic strategy to analyze the differential expression of serum glycoproteins between HCC and normal control serum samples. Lectin affinity chromatography (LAC) was used to enrich glycoproteins from the serum samples. Quantitative mass spectrometric analysis combined with stable isotope dimethyl labeling and 2D liquid chromatography (LC) separations were performed to examine the differential levels of the detected proteins between HCC and control serum samples. Western blot was used to analyze the differential expression levels of the three serum proteins. A total of 2,280 protein groups were identified in the serum samples from HCC patients by using the 2D LC-MS/MS method. Up to 36 proteins were up-regulated in the HCC serum, whereas 19 proteins were down-regulated. Three differential glycoproteins, namely, fibrinogen gamma chain (FGG), FOS-like antigen 2 (FOSL2), and α-1,6-mannosylglycoprotein 6-β-N-acetylglucosaminyltransferase B (MGAT5B) were validated by Western blot. All these three proteins were up-regulated in the HCC serum samples. A quantitative glycoproteomic method was established and proven useful to determine potential novel biomarkers for HCC

Hormone-like peptides in the venoms of marine cone snails

Science.gov (United States)

Robinson, Samuel D.; Li, Qing; Bandyopadhyay, Pradip K.; Gajewiak, Joanna; Yandell, Mark; Papenfuss, Anthony T.; Purcell, Anthony W.; Norton, Raymond S.; Safavi-Hemami, Helena

2015-01-01

The venoms of cone snails (genus Conus) are remarkably complex, consisting of hundreds of typically short, disulfide-rich peptides termed conotoxins. These peptides have diverse pharmacological targets, with injection of venom eliciting a range of physiological responses, including sedation, paralysis and sensory overload. Most conotoxins target the prey’s nervous system but evidence of venom peptides targeting neuroendocrine processes is emerging. Examples include vasopressin, RFamide neuropeptides and recently also insulin. To investigate the diversity of hormone/neuropeptide-like molecules in the venoms of cone snails we systematically mined the venom gland transcriptomes of several cone snail species and examined secreted venom peptides in dissected and injected venom of the Australian cone snail Conus victoriae. Using this approach we identified several novel hormone/neuropeptide-like toxins, including peptides similar to the bee brain hormone prohormone-4, the mollusc ganglia neuropeptide elevenin, and thyrostimulin, a member of the glycoprotein hormone family, and confirmed the presence of insulin. We confirmed that at least two of these peptides are not only expressed in the venom gland but also form part of the injected venom cocktail, unambiguously demonstrating their role in envenomation. Our findings suggest that hormone/neuropeptide-like toxins are a diverse and integral part of the complex envenomation strategy of Conus. Exploration of this group of venom components offers an exciting new avenue for the discovery of novel pharmacological tools and drug candidates, complementary to conotoxins. PMID:26301480

Hormone-like peptides in the venoms of marine cone snails.

Science.gov (United States)

Robinson, Samuel D; Li, Qing; Bandyopadhyay, Pradip K; Gajewiak, Joanna; Yandell, Mark; Papenfuss, Anthony T; Purcell, Anthony W; Norton, Raymond S; Safavi-Hemami, Helena

2017-04-01

The venoms of cone snails (genus Conus) are remarkably complex, consisting of hundreds of typically short, disulfide-rich peptides termed conotoxins. These peptides have diverse pharmacological targets, with injection of venom eliciting a range of physiological responses, including sedation, paralysis and sensory overload. Most conotoxins target the prey's nervous system but evidence of venom peptides targeting neuroendocrine processes is emerging. Examples include vasopressin, RFamide neuropeptides and recently also insulin. To investigate the diversity of hormone/neuropeptide-like molecules in the venoms of cone snails we systematically mined the venom gland transcriptomes of several cone snail species and examined secreted venom peptides in dissected and injected venom of the Australian cone snail Conus victoriae. Using this approach we identified several novel hormone/neuropeptide-like toxins, including peptides similar to the bee brain hormone prohormone-4, the mollusc ganglia neuropeptide elevenin, and thyrostimulin, a member of the glycoprotein hormone family, and confirmed the presence of insulin. We confirmed that at least two of these peptides are not only expressed in the venom gland but also form part of the injected venom cocktail, unambiguously demonstrating their role in envenomation. Our findings suggest that hormone/neuropeptide-like toxins are a diverse and integral part of the complex envenomation strategy of Conus. Exploration of this group of venom components offers an exciting new avenue for the discovery of novel pharmacological tools and drug candidates, complementary to conotoxins. Copyright © 2015 Elsevier Inc. All rights reserved.

Normal sweat secretion despite impaired growth hormone-insulin-like growth factor-I axis in obese subjects

DEFF Research Database (Denmark)

Rasmussen, Michael Højby; Juul, Anders; Main, Katharina M

2011-01-01

Adults with GH deficiency are known to exhibit reduced sweating. Whether sweating capacity is impacted in obese subjects with impaired GH secretion have not previously been investigated. The main objective was to investigate sweat secretion rate and the GH-IGF-I axis in obese subjects before...... and after weight loss. Sixteen severely obese women (BMI, 40.6 ± 1.1 kg/m(2)) were investigated before and after a diet-induced weight loss. Sixteen age-matched nonobese women served as controls. The obese subjects presented the characteristic decreased GH release, hyperinsulinaemia, increased FFA levels......, and impaired insulin sensitivity, which all were normalised after diet-induced weight loss of 30 ± 5 kg. Sweat secretion rates were similar comparing obese and nonobese subjects (78 ± 10 versus 82 ± 9 mg/30 minutes) and sweat secretion did not change after a diet-induced weight loss in obese subjects. We...

Glucagon-like peptides GLP-1 and GLP-2, predicted products of the glucagon gene, are secreted separately from pig small intestine but not pancreas

DEFF Research Database (Denmark)

Holst, J J; Poulsen, Steen Seier

1986-01-01

We developed specific antibodies and RIAs for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2), two predicted products of the glucagon gene, and studied the occurrence, nature, and secretion of immunoreactive GLP-1 and GLP-2 in pig pancreas and small intestine. Immunoreactive GLP-1 and GLP-2 were...

Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

Science.gov (United States)

Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

2015-02-01

Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

Tumor associated osteoclast-like giant cells promote tumor growth and lymphangiogenesis by secreting vascular endothelial growth factor-C

International Nuclear Information System (INIS)

Hatano, Yu; Nakahama, Ken-ichi; Isobe, Mitsuaki; Morita, Ikuo

2014-01-01

Highlights: • M-CSF and RANKL expressing HeLa cells induced osteoclastogenesis in vitro. • We established OGC-containing tumor model in vivo. • OGC-containing tumor became larger independent of M-CSF or RANKL effect. • VEGF-C secreted from OGCs was a one of candidates for OGC-containing tumor growth. - Abstract: Tumors with osteoclast-like giant cells (OGCs) have been reported in a variety of organs and exert an invasive and prometastatic phenotype, but the functional role of OGCs in the tumor environment has not been fully clarified. We established tumors containing OGCs to clarify the role of OGCs in tumor phenotype. A mixture of HeLa cells expressing macrophage colony-stimulating factor (M-CSF, HeLa-M) and receptor activator of nuclear factor-κB ligand (RANKL, HeLa-R) effectively supported the differentiation of osteoclast-like cells from bone marrow macrophages in vitro. Moreover, a xenograft study showed OGC formation in a tumor composed of HeLa-M and HeLa-R. Surprisingly, the tumors containing OGCs were significantly larger than the tumors without OGCs, although the growth rates were not different in vitro. Histological analysis showed that lymphangiogenesis and macrophage infiltration in the tumor containing OGCs, but not in other tumors were accelerated. According to quantitative PCR analysis, vascular endothelial growth factor (VEGF)-C mRNA expression increased with differentiation of osteoclast-like cells. To investigate whether VEGF-C expression is responsible for tumor growth and macrophage infiltration, HeLa cells overexpressing VEGF-C (HeLa-VC) were established and transplanted into mice. Tumors composed of HeLa-VC mimicked the phenotype of the tumors containing OGCs. Furthermore, the vascular permeability of tumor microvessels also increased in tumors containing OGCs and to some extent in VEGF-C-expressing tumors. These results suggest that macrophage infiltration and vascular permeability are possible mediators in these tumors. These

Glycoprotein expression by adenomatous polyps of the colon

Science.gov (United States)

Roney, Celeste A.; Xie, Jianwu; Xu, Biying; Jabour, Paul; Griffiths, Gary; Summers, Ronald M.

2008-03-01

Colon cancer is the second leading cause of cancer related deaths in the United States. Specificity in diagnostic imaging for detecting colorectal adenomas, which have a propensity towards malignancy, is desired. Adenomatous polyp specimens of the colon were obtained from the mouse model of colorectal cancer called adenomatous polyposis coli-multiple intestinal neoplasia (APC Min). Histological evaluation, by the legume protein Ulex europaeus agglutinin I (UEA-1), determined expression of the glycoprotein α-L-fucose. FITC-labelled UEA-1 confirmed overexpression of the glycoprotein by the polyps on fluorescence microscopy in 17/17 cases, of which 13/17 included paraffin-fixed mouse polyp specimens. In addition, FITC-UEA-1 ex vivo multispectral optical imaging of 4/17 colonic specimens displayed over-expression of the glycoprotein by the polyps, as compared to non-neoplastic mucosa. Here, we report the surface expression of α-L-fucosyl terminal residues by neoplastic mucosal cells of APC specimens of the mouse. Glycoprotein expression was validated by the carbohydrate binding protein UEA-1. Future applications of this method are the development of agents used to diagnose cancers by biomedical imaging modalities, including computed tomographic colonography (CTC). UEA-1 targeting to colonic adenomas may provide a new avenue for the diagnosis of colorectal carcinoma by CT imaging.

A Potato cDNA Encoding a Homologue of Mammalian Multidrug Resistant P-Glycoprotein

Science.gov (United States)

Wang, W.; Takezawa, D.; Poovaiah, B. W.

1996-01-01

A homologue of the multidrug resistance (MDR) gene was obtained while screening a potato stolon tip cDNA expression library with S-15-labeled calmodulin. The mammalian MDR gene codes for a membrane-bound P-glycoprotein (170-180 kDa) which imparts multidrug resistance to cancerous cells. The potato cDNA (PMDR1) codes for a polypeptide of 1313 amino acid residues (ca. 144 kDa) and its structural features are very similar to the MDR P-glycoprotein. The N-terminal half of the PMDR1-encoded protein shares striking homology with its C-terminal half, and each half contains a conserved ATP-binding site and six putative transmembrane domains. Southern blot analysis indicated that potato has one or two MDR-like genes. PMDR1 mRNA is constitutively expressed in all organs studied with higher expression in the stem and stolon tip. The PMDR1 expression was highest during tuber initiation and decreased during tuber development.

Secretive eating among youth with overweight or obesity.

Science.gov (United States)

Kass, Andrea E; Wilfley, Denise E; Eddy, Kamryn T; Boutelle, Kerri N; Zucker, Nancy; Peterson, Carol B; Le Grange, Daniel; Celio-Doyle, Angela; Goldschmidt, Andrea B

2017-07-01

Secretive eating, characterized by eating privately to conceal being seen, may reflect eating- and/or body-related shame, be associated with depression, and correlate with binge eating, which predicts weight gain and eating disorder onset. Increasing understanding of secretive eating in youth may improve weight status and reduce eating disorder risk. This study evaluated the prevalence and correlates of secretive eating in youth with overweight or obesity. Youth (N = 577) presented to five research/clinical institutions. Using a cross-sectional design, secretive eating was evaluated in relation to eating-related and general psychopathology via linear and logistic regression analyses. Secretive eating was endorsed by 111 youth, who were, on average, older than youth who denied secretive eating (mean age = 12.07 ± 2.83 versus 10.97 ± 2.31). Controlling for study site and age, youth who endorsed secretive eating had higher eating-related psychopathology and were more likely to endorse loss of control eating and purging than their counterparts who did not endorse secretive eating. Groups did not differ in excessive exercise or behavioral problems. Dietary restraint and purging were elevated among adolescents (≥13y) but not children (<13y) who endorsed secretive eating; depression was elevated among children, but not adolescents, who endorsed secretive eating. Secretive eating may portend heightened risk for eating disorders, and correlates of secretive eating may differ across pediatric development. Screening for secretive eating may inform identification of problematic eating behaviors, and understanding factors motivating secretive eating may improve intervention tailoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Dictyostelium secreted factor requires a PTEN-like phosphatase to slow proliferation and induce chemorepulsion.

Science.gov (United States)

Herlihy, Sarah E; Tang, Yitai; Gomer, Richard H

2013-01-01

In Dictyostelium discoideum, AprA and CfaD are secreted proteins that inhibit cell proliferation. We found that the proliferation of cells lacking CnrN, a phosphatase and tensin homolog (PTEN)-like phosphatase, is not inhibited by exogenous AprA and is increased by exogenous CfaD. The expression of CnrN in cnrN cells partially rescues these altered sensitivities, suggesting that CnrN is necessary for the ability of AprA and CfaD to inhibit proliferation. Cells lacking CnrN accumulate normal levels of AprA and CfaD. Like cells lacking AprA and CfaD, cnrN cells proliferate faster and reach a higher maximum cell density than wild type cells, tend to be multinucleate, accumulate normal levels of mass and protein per nucleus, and form less viable spores. When cnrN cells expressing myc-tagged CnrN are stimulated with a mixture of rAprA and rCfaD, levels of membrane-associated myc-CnrN increase. AprA also causes chemorepulsion of Dictyostelium cells, and CnrN is required for this process. Combined, these results suggest that CnrN functions in a signal transduction pathway downstream of AprA and CfaD mediating some, but not all, of the effects of AprA and CfaD.

Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

Science.gov (United States)

Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

2014-01-01

The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

Monoclonal antibody to an external epitope of the human mdr1 P-glycoprotein

NARCIS (Netherlands)

Arceci, R. J.; Stieglitz, K.; Bras, J.; Schinkel, A.; Baas, F.; Croop, J.

1993-01-01

A membrane glycoprotein, termed P-glycoprotein, has been shown to be responsible for cross-resistance to a broad range of structurally and functionally distinct cytotoxic agents. P-glycoprotein, encoded in humans by the mdr1 gene, functions as an energy-dependent efflux pump to exclude these

THE ROLE OF P-GLYCOPROTEIN IN RATIONAL PHARMACOTHERAPY IN CARDIOLOGY

Directory of Open Access Journals (Sweden)

A. V. Shulkin

2015-09-01

Full Text Available On the basis of the analysis of published data the role of P-glycoprotein, carrier protein, in rational pharmacotherapy in cardiology was shown on the example of its substrates – digoxin, antiplatelet agents and anticoagulants. Determination of C3435T polymorphism of multidrug resistance gene (MDR1, encoding P-glycoprotein, in pharmacotherapy with digoxin, antiplatelet drugs (clopidogrel tikagrelol, prasugrel and anticoagulants (dabigatran etexilate, rivaroxaban, edoxaban is not feasible in routine practice. Drug in- teractions have clinical implications for the efficacy and safety of pharmacotherapy in coadministration of these drugs with P-glycoprotein substrates, inducers and inhibitors.

Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters

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Fun-In Wang

2015-06-01

Full Text Available Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

Conditional expression of the vesicular stomatitis virus glycoprotein gene in Escherichia coli.

OpenAIRE

Rose, J K; Shafferman, A

1981-01-01

Bacterial plasmids that directed expression of the vesicular stomatitis virus glycoprotein (G-protein) gene under control of the tryptophan operon regulatory region were constructed. A plasmid directing the synthesis of a G-protein-like protein (containing the NH2-terminal segment of seven amino acids encoded by the trpE gene fused to the complete G-protein sequence lacking only its NH2-terminal methionine) could be transformed into trpR+ (repressed) but not into trpR- (derepressed) cells. Th...

Glycosylation of dengue virus glycoproteins and their interactions with carbohydrate receptors: possible targets for antiviral therapy.

Science.gov (United States)

Idris, Fakhriedzwan; Muharram, Siti Hanna; Diah, Suwarni

2016-07-01

Dengue virus, an RNA virus belonging to the genus Flavivirus, affects 50 million individuals annually, and approximately 500,000-1,000,000 of these infections lead to dengue hemorrhagic fever or dengue shock syndrome. With no licensed vaccine or specific antiviral treatments available to prevent dengue infection, dengue is considered a major public health problem in subtropical and tropical regions. The virus, like other enveloped viruses, uses the host's cellular enzymes to synthesize its structural (C, E, and prM/M) and nonstructural proteins (NS1-5) and, subsequently, to glycosylate these proteins to produce complete and functional glycoproteins. The structural glycoproteins, specifically the E protein, are known to interact with the host's carbohydrate receptors through the viral proteins' N-glycosylation sites and thus mediate the viral invasion of cells. This review focuses on the involvement of dengue glycoproteins in the course of infection and the virus' exploitation of the host's glycans, especially the interactions between host receptors and carbohydrate moieties. We also discuss the recent developments in antiviral therapies that target these processes and interactions, focusing specifically on the use of carbohydrate-binding agents derived from plants, commonly known as lectins, to inhibit the progression of infection.

Importance of the short cytoplasmic domain of the feline immunodeficiency virus transmembrane glycoprotein for fusion activity and envelope glycoprotein incorporation into virions

International Nuclear Information System (INIS)

Celma, Cristina C.P.; Paladino, Monica G.; Gonzalez, Silvia A.; Affranchino, Jose L.

2007-01-01

The mature form of the envelope (Env) glycoprotein of lentiviruses is a heterodimer composed of the surface (SU) and transmembrane (TM) subunits. Feline immunodeficiency virus (FIV) possesses a TM glycoprotein with a cytoplasmic tail of approximately 53 amino acids which is unusually short compared with that of the other lentiviral glycoproteins (more than 100 residues). To investigate the relevance of the FIV TM cytoplasmic domain to Env-mediated viral functions, we characterized the biological properties of a series of Env glycoproteins progressively shortened from the carboxyl terminus. All the mutant Env proteins were efficiently expressed in feline cells and processed into the SU and TM subunits. Deletion of 5 or 11 amino acids from the TM C-terminus did not significantly affect Env surface expression, fusogenic activity or Env incorporation into virions, whereas removal of 17 or 23 residues impaired Env-mediated cell-to-cell fusion. Further truncation of the FIV TM by 29 residues resulted in an Env glycoprotein that was poorly expressed at the cell surface, exhibited only 20% of the wild-type Env fusogenic capacity and was inefficiently incorporated into virions. Remarkably, deletion of the TM C-terminal 35 or 41 amino acids restored or even enhanced Env biological functions. Indeed, these mutant Env glycoproteins bearing cytoplasmic domains of 18 or 12 amino acids were found to be significantly more fusogenic than the wild-type Env and were efficiently incorporated into virions. Interestingly, truncation of the TM cytoplasmic domain to only 6 amino acids did not affect Env incorporation into virions but abrogated Env fusogenicity. Finally, removal of the entire TM cytoplasmic tail or deletion of as many as 6 amino acids into the membrane-spanning domain led to a complete loss of Env functions. Our results demonstrate that despite its relatively short length, the FIV TM cytoplasmic domain plays an important role in modulating Env-mediated viral functions

Short communication: Promotion of glucagon-like peptide-2 secretion in dairy calves with a bioactive extract from Olea europaea.

Science.gov (United States)

Morrison, S Y; Pastor, J J; Quintela, J C; Holst, J J; Hartmann, B; Drackley, J K; Ipharraguerre, I R

2017-03-01

Diarrhea episodes in dairy calves involve profound alterations in the mechanism controlling gut barrier function that ultimately compromise intestinal permeability to macromolecules, including pathogenic bacteria. Intestinal dysfunction models suggest that a key element of intestinal adaptation during the neonatal phase is the nutrient-induced secretion of glucagon-like peptide (GLP)-2 and associated effects on mucosal cell proliferation, barrier function, and inflammatory response. Bioactive molecules found in Olea europaea have been shown to induce the release of regulatory peptides from model enteroendocrine cells. The ability to enhance GLP-2 secretion via the feeding of putative GLP-2 secretagogues is untested in newborn calves. The objectives of this study were to determine whether feeding a bioactive extract from Olea europaea (OBE) mixed in the milk replacer (1) can stimulate GLP-2 secretion beyond the response elicited by enteral nutrients and, thereby, (2) improve intestinal permeability and animal growth as well as (3) reduce the incidence of diarrhea in preweaning dairy calves. Holstein heifer calves (n = 60) were purchased, transported to the research facility, and blocked by body weight and total serum protein and assigned to 1 of 3 treatments. Treatments were control (CON), standard milk replacer (MR) and ad libitum starter; CON plus OBE added into MR at 30 mg/kg of body weight (OBE30); and CON plus OBE added into MR at 60 mg/kg of body weight (OBE60). The concentration of GLP-2 was measured at the end of wk 2. Intestinal permeability was measured at the onset of the study and the end of wk 2 and 6, with lactulose and d-mannitol as markers. Treatments did not affect calf growth and starter intake. Compared with CON, administration of OBE60 increased the nutrient-induced response in GLP-2 by about 1 fold and reduced MR intake during the second week of study. Throughout the study, however, all calves had compromised intestinal permeability and a high

Quantitative mass spectrometric analysis of glycoproteins combined with enrichment methods.

Science.gov (United States)

Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

2015-01-01

Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.

A Method for Determining the Content of Glycoproteins in Biological Samples

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Yang Gao

2016-11-01

Full Text Available The glycoprotein purified from the mycelium extract of Tremella fuciformis was marked with iodine through the iodine substitution reaction. The content of iodine, which is indicative of the amount of the marked tremella glycoprotein (ITG, was detected with Inductively coupled plasma mass spectrometry (ICP-MS. The method was found to be stable, sensitive, and accurate at detecting the content of iodine-substituted glycoprotein, and was used in the quantitative analysis of biological samples, including blood and organs. Different biological samples were collected from rats after oral administration of ITG, and were tested for iodine content by ICP-MS to calculate the amount of ITG in the samples. The results suggested that ICP-MS is a sensitive, stable, and accurate method for detection of iodinated glycoproteins in blood and organs.

High level expression and secretion of truncated forms of herpes simplex virus type I and type 2 glycoprotein D by the methylotrophic yeast Pichia pastoris

NARCIS (Netherlands)

van Kooij, A; Middel, J; Jakab, F; Elfferich, P; Koedijk, DGAM; Feijlbrief, M; Scheffer, AJ; Degener, JE; The, TH; Scheek, RM; Welling, GW; Welling-Wester, S

Herpes simplex virus type I and 2 (HSV-1 and -2) glycoproteins D (gD-1 and gD-2) play a role in the entry of the virus into the host cell. Availability of substantial amounts of these proteins, or large fragments thereof. will he needed to allow studies at the molecular level. We studied the potency

P-glycoprotein in autoimmune rheumatic diseases.

Science.gov (United States)

García-Carrasco, M; Mendoza-Pinto, C; Macias Díaz, S; Vera-Recabarren, M; Vázquez de Lara, L; Méndez Martínez, S; Soto-Santillán, P; González-Ramírez, R; Ruiz-Arguelles, A

2015-07-01

P-glycoprotein (Pgp) is a transmembrane protein of 170 kD encoded by the multidrug resistance 1 (MDR-1) gene, localized on chromosome 7. More than 50 polymorphisms of the MDR-1 gene have been described; a subset of these has been shown to play a pathophysiological role in the development of inflammatory bowel disease, femoral head osteonecrosis induced by steroids, lung cancer and renal epithelial tumors. Polymorphisms that have a protective effect on the development of conditions such as Parkinson disease have also been identified. P-glycoprotein belongs to the adenosine triphosphate binding cassette transporter superfamily and its structure comprises a chain of approximately 1280 aminoacid residues with an N-C terminal structure, arranged as 2 homologous halves, each of which has 6 transmembrane segments, with a total of 12 segments with 2 cytoplasmic nucleotide binding domains. Many cytokines like interleukin 2 and tumor necrosis factor alpha increase Pgp expression and activity. Pgp functions as an efflux pump for a variety of toxins in order to protect particular organs and tissues as the central nervous system. Pgp transports a variety of substrates including glucocorticoids while other drugs such as tacrolimus and cyclosporine A act as modulators of this protein. The most widely used method to measure Pgp activity is flow cytometry using naturally fluorescent substrates such as anthracyclines or rhodamine 123. The study of drug resistance and its association to Pgp began with the study of resistance to chemotherapy in the treatment of cancer and antiretroviral therapy for human immunodeficiency virus; however, the role of Pgp in the treatment of systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis has been a focus of study lately and has emerged as an important mechanism by which treatment failure occurs. The present review analyzes the role of Pgp in these autoimmune diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Glycoprotein of the wall of sycamore tissue-culture cells.

Science.gov (United States)

Heath, M F; Northcote, D H

1971-12-01

1. A glycoprotein containing a large amount of hydroxyproline is present in the cell walls of sycamore callus cells. This protein is insoluble and remained in the alpha-cellulose when a mild separation procedure was used to obtain the polysaccharide fractions of the wall. The glycoprotein contained a high proportion of arabinose and galactose. 2. Soluble glycopeptides were prepared from the alpha-cellulose fraction when peptide bonds were broken by hydrazinolysis. The soluble material was fractionated by gel filtration and one glycopeptide was further purified by electrophoresis; it had a composition of 10% hydroxyproline, 35% arabinose and 55% galactose, and each hydroxyproline residue carried a glycosyl radical so that the oligosaccharides on the glycopeptide had an average degree of polymerization of 9. 3. The extraction of the glycopeptides was achieved without cleavage of glycosyl bonds, so that the glycoprotein cannot act as a covalent cross-link between the major polysaccharides of the wall. 4. The wall protein approximates in conformation to polyhydroxyproline and therefore it probably has similar physicochemical properties to polyhydroxyproline. This is discussed in relation to the function of the glycoprotein and its effect on the physical and chemical nature of the wall.

Cyclophilin A secreted from fibroblast-like synoviocytes is involved in the induction of CD147 expression in macrophages of mice with collagen-induced arthritis

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Nishioku Tsuyoshi

2012-11-01

Full Text Available Abstract Background Cyclophilin A (CypA, a member of the immunophilin family, is a ubiquitously distributed intracellular protein. Recent studies have shown that CypA is secreted by cells in response to inflammatory stimuli. Elevated levels of extracellular CypA and its receptor, CD147 have been detected in the synovium of patients with RA. However, the precise process of interaction between CypA and CD147 in the development of RA remains unclear. This study aimed to investigate CypA secretion from fibroblast-like synoviocytes (FLS isolated from mice with collagen-induced arthritis (CIA and CypA-induced CD147 expression in mouse macrophages. Findings CIA was induced by immunization with type II collagen in mice. The expression and localization of CypA and CD147 was investigated by immunoblotting and immunostaining. Both CypA and CD147 were highly expressed in the joints of CIA mice. CD147 was expressed in the infiltrated macrophages in the synovium of CIA mice. In vitro, spontaneous CypA secretion from FLS was detected and this secretion was increased by stimulation with lipopolysaccharide. CypA markedly increased CD147 levels in macrophages. Conclusions These findings suggest that an interaction in the synovial joints between extracellular CypA and CD147 expressed by macrophages may be involved in the mechanisms underlying the development of arthritis.

Global identification of prokaryotic glycoproteins based on an Escherichia coli proteome microarray.

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Zong-Xiu Wang

Full Text Available Glycosylation is one of the most abundant protein posttranslational modifications. Protein glycosylation plays important roles not only in eukaryotes but also in prokaryotes. To further understand the roles of protein glycosylation in prokaryotes, we developed a lectin binding assay to screen glycoproteins on an Escherichia coli proteome microarray containing 4,256 affinity-purified E.coli proteins. Twenty-three E.coli proteins that bound Wheat-Germ Agglutinin (WGA were identified. PANTHER protein classification analysis showed that these glycoprotein candidates were highly enriched in metabolic process and catalytic activity classes. One sub-network centered on deoxyribonuclease I (sbcB was identified. Bioinformatics analysis suggests that prokaryotic protein glycosylation may play roles in nucleotide and nucleic acid metabolism. Fifteen of the 23 glycoprotein candidates were validated by lectin (WGA staining, thereby increasing the number of validated E. coli glycoproteins from 3 to 18. By cataloguing glycoproteins in E.coli, our study greatly extends our understanding of protein glycosylation in prokaryotes.

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

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Rafael Simó

Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

Science.gov (United States)

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

Virus-like-vaccines against HIV

DEFF Research Database (Denmark)

Andersson, Anne Marie C.; Schwerdtfeger, Melanie; Holst, Peter J.

2018-01-01

Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (......Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus...... of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production...

A new potential secretion pathway for recombinant proteins in Bacillus subtilis.

Science.gov (United States)

Wang, Guangqiang; Xia, Yongjun; Gu, Zhennan; Zhang, Hao; Chen, Yong Q; Chen, Haiqin; Ai, Lianzhong; Chen, Wei

2015-11-10

Secretion of cytoplasmic expressed proteins into growth media has significant advantages. Due to the lack of an outer membrane, Bacillus subtilis is considered as a desirable 'cell factory' for the secretion of recombinant proteins. However, bottlenecks in the classical pathway for the secretion of recombinant proteins limit its use on a wide scale. In this study, we attempted to use four typical non-classically secreted proteins as signals to export three recombinant model proteins to the culture medium. All four non-classically secreted proteins can direct the export of the intrinsically disordered nucleoskeletal-like protein (Nsp). Two of them can guide the secretion of alkaline phosphatase (PhoA). One can lead the secretion of the thermostable β-galactosidase BgaB, which cannot be secreted with the aid of typical Sec-dependent signal peptides. Our results show that the non-classically secreted proteins lead the recombinant proteins to the culture medium, and thus non-classical protein secretion pathways can be exploited as a novel secretion pathway for recombinant proteins.

Surface (glyco-)proteins: primary structure and crystallization under microgravity conditions

Science.gov (United States)

Claus, H.; Akca, E.; Schultz, N.; Karbach, G.; Schlott, B.; Debaerdemaeker, T.; De Clercq, J.-P.; König, H.

2001-08-01

The Archaea comprise microorganisms that live under environmental extremes, like high temperature, low pH value or high salt concentration. Their cells are often covered by a single layer of (glyco)protein subunits (S-layer) in hexagonal arrangement. In order to get further hints about the molecular mechanisms of protein stabilization we compared the primary and secondary structures of archaeal S-layer (glyco)proteins. We found an increase of charged amino acids in the S-layer proteins of the extreme thermophilic species compared to their mesophilic counterparts. Our data and those of other authors suggest that ionic interactions, e.g., salt bridges seem to be played a major role in protein stabilization at high temperatures. Despite the differences in the growth optima and the predominance of some amino acids the primary structures of S-layers revealed also a significant degree of identity between phylogenetically related archaea. These obervations indicate that protein sequences of S-layers have been conserved during the evolution from extremely thermophilic to mesophilic life. To support these findings the three-dimensional structure of the S-layer proteins has to be elucidated. Recently, we described the first successful crystallization of an extreme thermophilic surface(glyco)protein under microgravity conditions.

3,3′,4,4′,5-Pentachlorobiphenyl Inhibits Drug Efflux Through P-Glycoprotein in KB-3 Cells Expressing Mutant Human P-Glycoprotein

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Hiroshi Fujise

2004-01-01

Full Text Available The effects on the drug efflux of 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126, the most toxic of all coplanar polychlorinated biphenyls (Co-PCBs, were examined in KB-3 cells expressing human wild-type and mutant P-glycoprotein in which the 61st amino acid was substituted for serine or phenylalanine (KB3-Phe61. In the cells expressing P-glycoproteins, accumulations of vinblastine and colchicine decreased form 85% to 92% and from 62% to 91%, respectively, and the drug tolerances for these chemicals were increased. In KB3-Phe61, the decreases in drug accumulation were inhibited by adding PCB-126 in a way similar to that with cyclosporine A: by adding 1 μM PCB-126, the accumulations of vinblastine and colchicine increased up to 3.3- and 2.3-fold, respectively. It is suggested that PCB-126 decreased the drug efflux by inhibiting the P-glycoprotein in KB3-Phe61. Since there were various P-glycoproteins and many congeners of Co-PCBs, this inhibition has to be considered a new cause of the toxic effects of Co-PCBs.

Matryoshka: Hiding Secret Communication in Plain Sight

OpenAIRE

Safaka, Iris; Fragouli, Christina; Argyraki, Katerina

2016-01-01

We want to enable a pair of communicating users to exchange secret messages while hiding the fact that secret communication is taking place. We propose a linguistic steganography approach, where each human message is hidden in another human-like message. A hard open question is how to keep the steganographic message small -- existing related tools tend to blow up its size, thereby revealing the use of steganography. We encrypt by compressing each message, mapping it to a plausible sequence of...

Prediction of conserved sites and domains in glycoproteins B, C and D of herpes viruses.

Science.gov (United States)

Rasheed, Muhammad Asif; Ansari, Abdur Rahman; Ihsan, Awais; Navid, Muhammad Tariq; Ur-Rehman, Shahid; Raza, Sohail

2018-03-01

Glycoprotein B (gB), C (gC) and D (gD) of herpes simplex virus are implicated in virus adsorption and penetration. The gB, gC and gD are glycoproteins for different processes of virus binding and attachment to the host cells. Moreover, their expression is necessary and sufficient to induce cell fusion in the absence of other glycoproteins. Egress of herpes simplex virus (HSV) and other herpes viruses from cells involves extensive modification of cellular membranes and sequential envelopment, de-envelopment and re-envelopment steps. Viral glycoproteins are important in these processes, and frequently two or more glycoproteins can largely suffice in any step. Hence, we target the 3 important glycoproteins (B, C and D) of eight different herpes viruses of different species. These species include human (HSV1 and 2), bovine (BHV1), equine (EHV1 and 4), chicken (ILT1 and MDV2) and pig (PRV1). By applying different bioinformatics tools, we highlighted the conserved sites in these glycoproteins which might be most significant regarding attachment and infection of the viruses. Moreover the conserved domains in these glycoproteins are also highlighted. From this study, we will able to analyze the role of different viral glycoproteins of different species during herpes virus adsorption and penetration. Moreover, this study will help to construct the antivirals that target the glycoproteins of different herpes viruses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adaptive Secret Sharing for Color Images

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Jia-Hong Li

2011-10-01

Full Text Available A secret sharing model can secure a secret over multiple noise-like shadows and remain recoverable despite multiple shadow failures. Even if some of the shadows are compromised, the secret will not be revealed as long as the number of the compromised shadows is smaller than a pre-determined threshold. Moreover, there are some necessary details of concerns: the malicious tampering on shadows must be detectable; the shadows must be concealed in a camouflage image with adequate quality to reduce suspicion and possible attack; color image properties must be considered. In addition to these concerns, in this paper, an adaptable mechanism is further designed to balance the hiding quantity and the quality of camouflage images depending on different applications.This is an important and interesting aspect that has never been discussed in previous research.

Glycoprotein and proteoglycan techniques

International Nuclear Information System (INIS)

Beeley, J.G.

1985-01-01

The aim of this book is to describe techniques which can be used to answer some of the basic questions about glycosylated proteins. Methods are discussed for isolation, compositional analysis, and for determination of the primary structure of carbohydrate units and the nature of protein-carbohydrate linkages of glycoproteins and proteoglycans. High resolution NMR is considered, as well as radioactive labelling techniques. (Auth.)

HIV-1 envelope glycoprotein

Science.gov (United States)

Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

2017-08-22

The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

A Dictyostelium secreted factor requires a PTEN-like phosphatase to slow proliferation and induce chemorepulsion.

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Sarah E Herlihy

Full Text Available In Dictyostelium discoideum, AprA and CfaD are secreted proteins that inhibit cell proliferation. We found that the proliferation of cells lacking CnrN, a phosphatase and tensin homolog (PTEN-like phosphatase, is not inhibited by exogenous AprA and is increased by exogenous CfaD. The expression of CnrN in cnrN cells partially rescues these altered sensitivities, suggesting that CnrN is necessary for the ability of AprA and CfaD to inhibit proliferation. Cells lacking CnrN accumulate normal levels of AprA and CfaD. Like cells lacking AprA and CfaD, cnrN cells proliferate faster and reach a higher maximum cell density than wild type cells, tend to be multinucleate, accumulate normal levels of mass and protein per nucleus, and form less viable spores. When cnrN cells expressing myc-tagged CnrN are stimulated with a mixture of rAprA and rCfaD, levels of membrane-associated myc-CnrN increase. AprA also causes chemorepulsion of Dictyostelium cells, and CnrN is required for this process. Combined, these results suggest that CnrN functions in a signal transduction pathway downstream of AprA and CfaD mediating some, but not all, of the effects of AprA and CfaD.

Open Secrets

OpenAIRE

Madison, Michael

2017-01-01

The law of trade secrets is often conceptualized in bilateral terms, as creating and enforcing rights between trade secret owners, on the one hand, and misappropriators on the other hand. This paper, a chapter in a forthcoming collection on the law of trade secrets, argues that trade secrets and the law that guards them can serve structural and insitutional roles as well. Somewhat surprisingly, given the law’s focus on secrecy, among the institutional products of trade secrets law are commons...

An engineered diatom acting like a plasma cell secreting human IgG antibodies with high efficiency

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Hempel Franziska

2012-09-01

Full Text Available Abstract Background Although there are many different expression systems for recombinant production of pharmaceutical proteins, many of these suffer from drawbacks such as yield, cost, complexity of purification, and possible contamination with human pathogens. Microalgae have enormous potential for diverse biotechnological applications and currently attract much attention in the biofuel sector. Still underestimated, though, is the idea of using microalgae as solar-fueled expression system for the production of recombinant proteins. Results In this study, we show for the first time that completely assembled and functional human IgG antibodies can not only be expressed to high levels in algal systems, but also secreted very efficiently into the culture medium. We engineered the diatom Phaeodactylum tricornutum to synthesize and secrete a human IgG antibody against the Hepatitis B Virus surface protein. As the diatom P. tricornutum is not known to naturally secrete many endogenous proteins, the secreted antibodies are already very pure making extensive purification steps redundant and production extremely cost efficient. Conclusions Microalgae combine rapid growth rates with all the advantages of eukaryotic expression systems, and offer great potential for solar-powered, low cost production of pharmaceutical proteins.

Effects of glucagon-like peptide 1 on counterregulatory hormone responses, cognitive functions, and insulin secretion during hyperinsulinemic, stepped hypoglycemic clamp experiments in healthy volunteers

DEFF Research Database (Denmark)

Nauck, Michael A; Heimesaat, Markus M; Behle, Kai

2002-01-01

and neuroglucopenic symptoms were assessed, and cognitive function was tested at each plateau. Insulin secretion rates were estimated by deconvolution (two-compartment model of C-peptide kinetics). At insulin concentrations of approximately 45 mU/liter, glucose infusion rates were similar with and without GLP-1 (P......Glucagon-like peptide 1 (GLP-1) and analogues are being evaluated as a new therapeutic principle for the treatment of type 2 diabetes. GLP-1 suppresses glucagon secretion, which could lead to disturbances of hypoglycemia counterregulation. This has, however, not been tested. Nine healthy volunteers.......97). The other counterregulatory hormones and autonomic or neuroglucopenic symptom scores increased, and cognitive functions decreased with decreasing glucose concentrations, but there were no significant differences comparing experiments with GLP-1 or placebo, except for a significant reduction of GH responses...

Lipoidal Labellar Secretions in Maxillaria Ruiz & Pav. (Orchidaceae)

OpenAIRE

DAVIES, K. L.; TURNER, M. P.; GREGG, A.

2003-01-01

The labella of Maxillaria acuminata Lindl., M. cerifera Barb. Rodr. and M. notylioglossa Rchb.f., all members of the M. acuminata alliance, produce a viscid wax‐like secretion. Histochemical analysis revealed that the chemical composition of the secretion is similar in all three species, consisting largely of lipid and protein. Light microscopy and low‐vacuum scanning electron microscopy were used to investigate the secretory process. In a fourth taxon, M. cf. notylioglossa, transmission elec...

Caught in the act: discovering secreted proteins from fungi and oomycetes in action

DEFF Research Database (Denmark)

Roth, Doris; Grell, Morten Nedergaard; Jensen, Annette Bruun

Host-microbe relationships largely rely on secreted proteins like enzymes, virulence factors and antimicrobial peptides. To discover proteins secreted by microbe and host during the interaction with each other, we produced dual-organism cDNA libraries from three different fungus- or oomycete-infe......, by applying a similar strategy with a fungus-only library. As a result, we will show that our approach is widely applicable and allows us to deepen the understanding a variety of different host-microbe systems.......Host-microbe relationships largely rely on secreted proteins like enzymes, virulence factors and antimicrobial peptides. To discover proteins secreted by microbe and host during the interaction with each other, we produced dual-organism cDNA libraries from three different fungus- or oomycete...

Shigella IpaD has a dual role: signal transduction from the type III secretion system needle tip and intracellular secretion regulation.

Science.gov (United States)

Roehrich, A Dorothea; Guillossou, Enora; Blocker, Ariel J; Martinez-Argudo, Isabel

2013-02-01

Type III secretion systems (T3SSs) are protein injection devices essential for the interaction of many Gram-negative bacteria with eukaryotic cells. While Shigella assembles its T3SS when the environmental conditions are appropriate for invasion, secretion is only activated after physical contact with a host cell. First, the translocators are secreted to form a pore in the host cell membrane, followed by effectors which manipulate the host cell. Secretion activation is tightly controlled by conserved T3SS components: the needle tip proteins IpaD and IpaB, the needle itself and the intracellular gatekeeper protein MxiC. To further characterize the role of IpaD during activation, we combined random mutagenesis with a genetic screen to identify ipaD mutant strains unable to respond to host cell contact. Class II mutants have an overall defect in secretion induction. They map to IpaD's C-terminal helix and likely affect activation signal generation or transmission. The Class I mutant secretes translocators prematurely and is specifically defective in IpaD secretion upon activation. A phenotypically equivalent mutant was found in mxiC. We show that IpaD and MxiC act in the same intracellular pathway. In summary, we demonstrate that IpaD has a dual role and acts at two distinct locations during secretion activation. © 2013 Blackwell Publishing Ltd.

Glucagon-Like Peptide-1 Secreting Cell Function as well as Production of Inflammatory Reactive Oxygen Species Is Differently Regulated by Glycated Serum and High Levels of Glucose

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Alessandra Puddu

2014-01-01

Full Text Available Glucagon-like peptide-1 (GLP-1, an intestinal hormone contributing to glucose homeostasis, is synthesized by proglucagon and secreted from intestinal neuroendocrine cells in response to nutrients. GLP-1 secretion is impaired in type 2 diabetes patients. Here, we aimed at investigating whether diabetic toxic products (glycated serum (GS or high levels of glucose (HG may affect viability, function, and insulin sensitivity of the GLP-1 secreting cell line GLUTag. Cells were cultured for 5 days in presence or absence of different dilutions of GS or HG. GS and HG (alone or in combination increased reactive oxygen species (ROS production and upregulated proglucagon mRNA expression as compared to control medium. Only HG increased total production and release of active GLP-1, while GS alone abrogated secretion of active GLP-1. HG-mediated effects were associated with the increased cell content of the prohormone convertase 1/3 (PC 1/3, while GS alone downregulated this enzyme. HG upregulated Glucokinase (GK and downregulated SYNTHAXIN-1. GS abrogated SYNTHAXIN-1 and SNAP-25. Finally, high doses of GS alone or in combination with HG reduced insulin-mediated IRS-1 phosphorylation. In conclusion, we showed that GS and HG might regulate different pathways of GLP-1 production in diabetes, directly altering the function of neuroendocrine cells secreting this hormone.

The NS1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease.

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Andrew K I Falconar

Full Text Available Antibody-enhanced replication (AER of dengue type-2 virus (DENV-2 strains and production of antibody-enhanced disease (AED was tested in out-bred mice. Polyclonal antibodies (PAbs generated against the nonstructural-1 (NS1 glycoprotein candidate vaccine of the New Guinea-C (NG-C or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (<0.5 LD₅₀ of the DENV-2 NSx strain, but not the NG-C strain, they all generated dramatic and lethal DENV-2 AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS, displayed by diffuse alveolar damage (DAD resulting from i dramatic interstitial alveolar septa-thickening with mononuclear cells, ii some hyperplasia of alveolar type-II pneumocytes, iii copious intra-alveolar protein secretion, iv some hyaline membrane-covered alveolar walls, and v DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human "severe dengue" cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines

Crystallization and preliminary X-ray analysis of Chandipura virus glycoprotein G

International Nuclear Information System (INIS)

Baquero, Eduard; Buonocore, Linda; Rose, John K.; Bressanelli, Stéphane; Gaudin, Yves; Albertini, Aurélie A.

2012-01-01

Chandipura virus glycoprotein ectodomain (Gth) was purified and crystallized at pH 7.5. X-ray diffraction data set was collected to a resolution of 3.1 Å. Fusion in members of the Rhabdoviridae virus family is mediated by the G glycoprotein. At low pH, the G glycoprotein catalyzes fusion between viral and endosomal membranes by undergoing a major conformational change from a pre-fusion trimer to a post-fusion trimer. The structure of the G glycoprotein from vesicular stomatitis virus (VSV G), the prototype of Vesiculovirus, has recently been solved in its trimeric pre-fusion and post-fusion conformations; however, little is known about the structural details of the transition. In this work, a soluble form of the ectodomain of Chandipura virus G glycoprotein (CHAV G th ) was purified using limited proteolysis of purified virus; this soluble ectodomain was also crystallized. This protein shares 41% amino-acid identity with VSV G and thus its structure could provide further clues about the structural transition of rhabdoviral glycoproteins induced by low pH. Crystals of CHAV G th obtained at pH 7.5 diffracted X-rays to 3.1 Å resolution. These crystals belonged to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 150.3, b = 228.2, c = 78.8 Å. Preliminary analysis of the data based on the space group and the self-rotation function indicated that there was no trimeric association of the protomers. This unusual oligomeric status could result from the presence of fusion intermediates in the crystal

Autophagy-dependent secretion: contribution to tumor progression

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Tom Keulers

2016-11-01

Full Text Available Autophagy is best known as a lysosomal degradation and recycling pathway to maintain cellular homeostasis. During autophagy, cytoplasmic content is recognized and packed in autophagic vacuoles, or autophagosomes, and targeted for degradation. However, during the last years, it has become evident that the role of autophagy is not restricted to degradation alone but also mediates unconventional forms of secretion. Furthermore, cells with defects in autophagy apparently are able to reroute their cargo, like mitochondria, to the extracellular environment; effects that contribute to an array of pathologies. In this review we discuss the current knowledge of the physiological roles of autophagy-dependent secretion, i.e. the effect on inflammation and insulin/ hormone secretion. Finally, we focus on the effects of autophagy-dependent secretion on the tumour microenvironment and tumour progression. The autophagy mediated secreted factors may stimulate cellular proliferation via auto- and paracrine signaling. The autophagy mediated release of immune modulating proteins change the immunosuppresive tumor microenvironment and may promote an invasive phenotype. These effects may be either direct or indirect through facilitating formation of the mobilized vesicle, aid in anterograde trafficking or alterations in homeostasis and/or autonomous cell signaling.

Synthetic glycopeptides and glycoproteins with applications in biological research

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Ulrika Westerlind

2012-05-01

Full Text Available Over the past few years, synthetic methods for the preparation of complex glycopeptides have been drastically improved. The need for homogenous glycopeptides and glycoproteins with defined chemical structures to study diverse biological phenomena further enhances the development of methodologies. Selected recent advances in synthesis and applications, in which glycopeptides or glycoproteins serve as tools for biological studies, are reviewed. The importance of specific antibodies directed to the glycan part, as well as the peptide backbone has been realized during the development of synthetic glycopeptide-based anti-tumor vaccines. The fine-tuning of native chemical ligation (NCL, expressed protein ligation (EPL, and chemoenzymatic glycosylation techniques have all together enabled the synthesis of functional glycoproteins. The synthesis of structurally defined, complex glycopeptides or glyco-clusters presented on natural peptide backbones, or mimics thereof, offer further possibilities to study protein-binding events.

Mucin-like protein, a saliva component involved in brown planthopper virulence and host adaptation.

Science.gov (United States)

Huang, Hai-Jian; Liu, Cheng-Wen; Xu, Hai-Jun; Bao, Yan-Yuan; Zhang, Chuan-Xi

2017-04-01

The rice brown planthopper (BPH), Nilaparvata lugens, can rapidly adapt to new resistant rice varieties within several generations, rendering its management burdensome. However, the molecular mechanism underlying its adaptability remains unclear. In this study, we investigated the potential role of mucin-like protein (NlMul) in N. lugens virulence and adaptation to host resistance. NlMul is an important glycoprotein that constitutes both gelling and watery saliva, and specifically expressed in the salivary glands at all developmental stages except the egg period. Knocking down the expression of NlMul resulted in the secretion of short and single-branched salivary sheaths. NlMul might help BPH deal with plant resistance, and altered gene expression was observed when BPHs were transferred from a susceptible rice variety to a resistant one. The NlMul-deficient BPHs showed disordered developmental duration and a portion of these insects reared on resistant rice exhibited lethal effects. Our results uncover a saliva-mediated interaction between insect and host plant, and provide useful information in rice breeding and planthopper management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Co-immunization with virus-like particle and DNA vaccines induces protection against respiratory syncytial virus infection and bronchiolitis

Science.gov (United States)

Hwang, Hye Suk; Kwon, Young-Man; Lee, Jong Seok; Yoo, Si-Eun; Lee, Yu-Na; Ko, Eun-Ju; Kim, Min-Chul; Cho, Min-Kyoung; Lee, Young-Tae; Jung, Yu-Jin; Lee, Ji-Yun; Li, Jian Dong; Kang, Sang-Moo

2014-01-01

This study demonstrates that immunization with non-replicating virus-like particle (FFG VLP) containing RSV F and G glycoproteins together with RSV F DNA induced T helper type 1 antibody responses to RSV F similar to live RSV infection. Upon RSV challenge 21 weeks after immunization, FFG VLP vaccination induced protection against RSV infection as shown by clearance of lung viral loads, and the absence of eosinophil infiltrates, and did not cause lung pathology. In contrast, formalin-inactivated RSV (FI-RSV) vaccination showed significant pulmonary eosinophilia, severe mucus production, and extensive histopathology resulting in a hallmark of pulmonary pathology. Substantial lung pathology was also observed in mice with RSV re-infections. High levels of systemic and local inflammatory cytokine-secreting cells were induced in mice with FI-RSV but not with FFG VLP immunization after RSV challenge. Therefore, the results provide evidence that recombinant RSV FFG VLP vaccine can confer long-term protection against RSV without causing lung pathology. PMID:25110201

Three-dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation

OpenAIRE

Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W. Andy

2016-01-01

Glycoproteins have vast structural diversity which plays an important role in many biological processes and have great potential as disease biomarkers. Here we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase GlycoProtein Array (polyGPA), to specifically capture and profile glycoproteomes, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture pre-oxidized glycan...

CD109 is a component of exosome secreted from cultured cells

International Nuclear Information System (INIS)

Sakakura, Hiroki; Mii, Shinji; Hagiwara, Sumitaka; Kato, Takuya; Yamamoto, Noriyuki; Hibi, Hideharu; Takahashi, Masahide; Murakumo, Yoshiki

2016-01-01

Exosomes are 50–100-nm-diameter membrane vesicles released from various types of cells. Exosomes retain proteins, mRNAs and miRNAs, which can be transported to surrounding cells. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, and is released from the cell surface to the culture medium in vitro. Recently, it was reported that secreted CD109 from the cell surface downregulates transforming growth factor-β signaling in human keratinocytes. In this study, we revealed that CD109 is a component of the exosome in conditioned medium. FLAG-tagged human CD109 (FLAG-CD109) in conditioned medium secreted from HEK293 cells expressing FLAG-CD109 (293/FLAG-CD109) was immunoprecipitated with anti-FLAG affinity gel, and the co-precipitated proteins were analyzed by mass spectrometry and western blotting. Exosomal proteins were associated with CD109. We revealed the presence of CD109 in exosome fractions from conditioned medium of 293/FLAG-CD109. Moreover, the localization of CD109 in the exosome was demonstrated using immuno-electron microscopy. When we used HEK293 cells expressing FLAG-tagged truncated CD109, which does not contain the C-terminal region, the association of truncated CD109 with exosomes was not detected in conditioned medium. These findings indicate that CD109 is an exosomal protein and that the C-terminal region of CD109 is required for its presence in the exosome. - Highlights: • CD109 is an exosomal protein. • The C-terminal region of CD109 is required for its presence in the exosome. • Part of the secreted CD109 is present in the exosome-free fraction in the conditioned medium.

CD109 is a component of exosome secreted from cultured cells

Energy Technology Data Exchange (ETDEWEB)

Sakakura, Hiroki [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Mii, Shinji [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Hagiwara, Sumitaka [Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Nagoya (Japan); Kato, Takuya [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Yamamoto, Noriyuki; Hibi, Hideharu [Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Takahashi, Masahide, E-mail: mtakaha@med.nagoya-u.ac.jp [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Murakumo, Yoshiki, E-mail: murakumo@med.kitasato-u.ac.jp [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Pathology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan)

2016-01-22

Exosomes are 50–100-nm-diameter membrane vesicles released from various types of cells. Exosomes retain proteins, mRNAs and miRNAs, which can be transported to surrounding cells. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, and is released from the cell surface to the culture medium in vitro. Recently, it was reported that secreted CD109 from the cell surface downregulates transforming growth factor-β signaling in human keratinocytes. In this study, we revealed that CD109 is a component of the exosome in conditioned medium. FLAG-tagged human CD109 (FLAG-CD109) in conditioned medium secreted from HEK293 cells expressing FLAG-CD109 (293/FLAG-CD109) was immunoprecipitated with anti-FLAG affinity gel, and the co-precipitated proteins were analyzed by mass spectrometry and western blotting. Exosomal proteins were associated with CD109. We revealed the presence of CD109 in exosome fractions from conditioned medium of 293/FLAG-CD109. Moreover, the localization of CD109 in the exosome was demonstrated using immuno-electron microscopy. When we used HEK293 cells expressing FLAG-tagged truncated CD109, which does not contain the C-terminal region, the association of truncated CD109 with exosomes was not detected in conditioned medium. These findings indicate that CD109 is an exosomal protein and that the C-terminal region of CD109 is required for its presence in the exosome. - Highlights: • CD109 is an exosomal protein. • The C-terminal region of CD109 is required for its presence in the exosome. • Part of the secreted CD109 is present in the exosome-free fraction in the conditioned medium.

Filamentous fungi as production organisms for glycoproteins of bio-medical interest

NARCIS (Netherlands)

Maras, M.; Die, I. van; Contreras, R.; Hondel, C.A.M.J.J. van den

1999-01-01

Filamentous fungi are commonly used in the fermentation industry for large scale production of glycoproteins. Several of these proteins can be produced in concentrations up to 20-40 g per litre. The production of heterologous glycoproteins is at least one or two orders of magnitude lower but

Glucagon-like peptide 2 inhibits ghrelin secretion in humans

DEFF Research Database (Denmark)

Banasch, Matthias; Bulut, Kerem; Hagemann, Dirk

2006-01-01

INTRODUCTION: The growth hormone secretagogue receptor ligand ghrelin is known to play a pivotal role in the central nervous control of energy homeostasis. Circulating ghrelin levels are high under fasting conditions and decline after meal ingestion, but the mechanisms underlying the postprandial...... drop in ghrelin levels are poorly understood. In the present study we addressed, whether (1) exogenous GLP-2 administration decreases ghrelin levels and (2) what other endogenous factors are related to ghrelin secretion under fasting conditions. PATIENTS AND METHODS: Fifteen healthy male volunteers...... were studied with the intravenous infusion of GLP-2 (2 pmol l(-1) min(-1)) or placebo over 120 min in the fasting state. Plasma concentrations of glucose, insulin, C-peptide, glucagon, intact GLP-2 and ghrelin were determined. RESULTS: During the infusion of GLP-2, plasma concentrations of intact GLP-2...

Protective Effect of Prosopis cineraria Against N-Nitrosodiethylamine Induced Liver Tumor by Modulating Membrane Bound Enzymes and Glycoproteins

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Naina Mohamed Pakkir Maideen

2012-06-01

Full Text Available Purpose: The objective of the present study was to evaluate the protective effect of methanol extract of Prosopis cineraria (MPC against N-nitrosodiethylamine (DEN, 200mg/kg induced Phenobarbital promoted experimental liver tumors in male Wistar rats. Methods: The rats were divided into four groups, each group consisting of six animals. Group 1 served as control animals. Liver tumor was induced in group 2, 3, and 4 and Group 3 animals received MPC 200mg/kg and Group 4 animals received MPC 400mg/kg. Results: Administration of DEN has brought down the levels of membrane bound enzymes like Na+/ K+ ATPase, Mg2+ ATPase and Ca2+ATPase which were later found to be increased by the administration of Prosopis cineraria (200 and 400mg/kg in dose dependent manner. The MPC extract also suppressed the levels of glycoproteins like Hexose, Hexosamine and Sialic acid when compared to liver tumor bearing animals. Conclusions: Our study suggests that MPC may extend its protective role by modulating the levels of membrane bound enzymes and suppressing glycoprotein levels.

Co-treatment by docetaxel and vinblastine breaks down P-glycoprotein mediated chemo-resistance

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Mahsa Mohseni

2016-03-01

Results: Combination treatment of the cells with docetaxel and vinblastine decreased the IC50 values for docetaxel from (30±3.1 to (15±2.6 nM and for vinblastine from (30±5.9 to (5±5.6 nM (P≤0.05.               P-glycoprotein mRNA expression level showed a significant up-regulation in the cells incubated with each drug alone (P≤0.001. Incubation of the cells with combined concentrations of both agents neutralized P-glycoprotein overexpression (P≤0.05. Adding verapamil, a P-glycoprotein inhibitor caused a further increase in the percentage of apoptotic cells when the cells were treated with both agents.  Conclusion:Our results suggest that combination therapy along with P-glycoprotein inhibition can be considered as a novel approach to improve the efficacy of chemotherapeutics in cancer patients with high P-glycoprotein expression.

Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

International Nuclear Information System (INIS)

Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

1983-01-01

Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP. Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. We have compared the results obtained by the two methods, using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI2 or PGE1 was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP. It is suggested that there are advantages and disadvantages to both methods of measurement of platelet aggregation and that the parameters being measured must be clearly understood to properly interpret the results

Pregnancy-specific glycoproteins bind integrin αIIbβ3 and inhibit the platelet-fibrinogen interaction.

Science.gov (United States)

Shanley, Daniel K; Kiely, Patrick A; Golla, Kalyan; Allen, Seamus; Martin, Kenneth; O'Riordan, Ronan T; Ball, Melanie; Aplin, John D; Singer, Bernhard B; Caplice, Noel; Moran, Niamh; Moore, Tom

2013-01-01

Pregnancy-specific glycoproteins (PSGs) are immunoglobulin superfamily members encoded by multigene families in rodents and primates. In human pregnancy, PSGs are secreted by the syncytiotrophoblast, a fetal tissue, and reach a concentration of up to 400 ug/ml in the maternal bloodstream at term. Human and mouse PSGs induce release of anti-inflammatory cytokines such as IL-10 and TGFβ1 from monocytes, macrophages, and other cell types, suggesting an immunoregulatory function. RGD tri-peptide motifs in the majority of human PSGs suggest that they may function like snake venom disintegrins, which bind integrins and inhibit interactions with ligands. We noted that human PSG1 has a KGD, rather than an RGD motif. The presence of a KGD in barbourin, a platelet integrin αIIbβ3 antagonist found in snake venom, suggested that PSG1 may be a selective αIIbβ3 ligand. Here we show that human PSG1 binds αIIbβ3 and inhibits the platelet - fibrinogen interaction. Unexpectedly, however, the KGD is not critical as multiple PSG1 domains independently bind and inhibit αIIbβ3 function. Human PSG9 and mouse Psg23 are also inhibitory suggesting conservation of this function across primate and rodent PSG families. Our results suggest that in species with haemochorial placentation, in which maternal blood is in direct contact with fetal trophoblast, the high expression level of PSGs reflects a requirement to antagonise abundant (3 mg/ml) fibrinogen in the maternal circulation, which may be necessary to prevent platelet aggregation and thrombosis in the prothrombotic maternal environment of pregnancy.

Glycoproteins and sialyl transferase of human B lymphoblastoid cell lines

International Nuclear Information System (INIS)

Lui, S.W.L.; Ng, M.H.

1980-01-01

We used two radiolabeling methods to study glycoproteins on the surface of lymphoblastoid cells. One of the methods affects tritiation of residues which are oxidized with galactose oxidase and the other causes tritiation of neuraminic acid residues. This approach was shown to allow a better resolution of cell surface glycoproteins than if either method were used alone. Glycoproteins of B 1 - 19 cells which harbor the Epstein-Barr virus genomes were compared with those of its parental cell line, BJAB, which does not harbor the viral genomes. These studies did not reveal a unique viral protein. A 28,000 mol. wt. glycoprotein was found to be the most prominent neuraminic acidlabeled product of B 1 - 19 cells and also of the two other cell lines, Raji and Ly38, which harbor the EBV genomes. A similar molecular weight species from BJAB cells identified by galactose oxidase labeling might be deficient in neuraminic acid residues as it was poorly labeled by the periodate oxidation method. The neuraminic acid content and level of sialyl transferase of BJAB cells were found to be lower than those of the other cell lines studied. (auth.)

Identification, isolation, and N-terminal sequencing of style glycoproteins associated with self-incompatibility in Nicotiana alata.

Science.gov (United States)

Jahnen, W; Batterham, M P; Clarke, A E; Moritz, R L; Simpson, R J

1989-05-01

S-Gene-associated glycoproteins (S-glycoproteins) from styles of Nicotiana alata, identified by non-equilibrium two-dimensional electrophoresis, were purified by cation exchange fast protein liquid chromatography with yields of 0.5 to 8 micrograms of protein per style, depending on the S-genotype of the plant. The method relies on the highly basic nature of the S-glycoproteins. The elution profiles of the different S-glycoproteins from the fast protein liquid chromatography column were characteristic of each S-glycoprotein, and could be used to establish the S-genotype of plants in outbreeding populations. In all cases, the S-genotype predicted from the style protein profile corresponded to that predicted from DNA gel blot analysis using S-allele-specific DNA probes and to that established by conventional breeding tests. Amino-terminal sequences of five purified S-glycoproteins showed a high degree of homology with the previously published sequences of N. alata and Lycopersicon esculentum S-glycoproteins.

Activation of the classical pathway of complement by tobacco glycoprotein (TGP).

Science.gov (United States)

Koethe, S M; Nelson, K E; Becker, C G

1995-07-15

Tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from tobacco leaves, activates the classical complement pathway through a mechanism that appears to involve direct interaction with C1q. A binding site on C1q for TGP can be localized by competitive inhibition with DNA to a region located in the junction between the collagen-like and globular regions of the molecule. A protein with activity similar to TGP has also been isolated from cigarette smoke condensate (TGP-S); it shares a binding site on C1q with TGP and has similar functional activity, with the exception that complement activation does not proceed to formation of a C3 cleaving enzyme. The ability of TGP and TGP-S to activate complement can be partially duplicated using polyphenols associated with tobacco leaf and smoke, i.e., chlorogenic acid and rutin. These polyphenols also compete with TGP for a binding site on immobilized C1q, suggesting that the polyphenol portion of TGP is critical for activation of complement. These results provide an additional mechanism for complement activation by cigarette products that, in vivo, could result in a localized complement depletion, generation of biologically active complement cleavage products, and initiation of an inflammatory response.

The H2 receptor antagonist nizatidine is a P-glycoprotein substrate: characterization of its intestinal epithelial cell efflux transport.

Science.gov (United States)

Dahan, Arik; Sabit, Hairat; Amidon, Gordon L

2009-06-01

The aim of this study was to elucidate the intestinal epithelial cell efflux transport processes that are involved in the intestinal transport of the H(2) receptor antagonist nizatidine. The intestinal epithelial efflux transport mechanisms of nizatidine were investigated and characterized across Caco-2 cell monolayers, in the concentration range 0.05-10 mM in both apical-basolateral (AP-BL) and BL-AP directions, and the transport constants of P-glycoprotein (P-gp) efflux activity were calculated. The concentration-dependent effects of various P-gp (verapamil, quinidine, erythromycin, ketoconazole, and cyclosporine A), multidrug resistant-associated protein 2 (MRP2; MK-571, probenecid, indomethacin, and p-aminohipuric acid), and breast cancer resistance protein (BCRP; Fumitremorgin C) inhibitors on nizatidine bidirectional transport were examined. Nizatidine exhibited 7.7-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. All P-gp inhibitors investigated displayed concentration-dependent inhibition on nizatidine secretion in both directions. The IC(50) of verapamil on nizatidine P-gp secretion was 1.2 x 10(-2) mM. In the absence of inhibitors, nizatidine displayed concentration-dependent secretion, with one saturable (J(max) = 5.7 x 10(-3) nmol cm(-2) s(-1) and K(m) = 2.2 mM) and one nonsaturable component (K(d) = 7 x 10(-4) microL cm(-2) s(-1)). Under complete P-gp inhibition, nizatidine exhibited linear secretory flux, with a slope similar to the nonsaturable component. V(max) and K(m) estimated for nizatidine P-gp-mediated secretion were 4 x 10(-3) nmol cm(-2) s(-1) and 1.2 mM, respectively. No effect was obtained with the MRP2 or the BCRP inhibitors. Being a drug commonly used in pediatrics, adults, and elderly, nizatidine susceptibility to efflux transport by P-gp revealed in this paper may be of significance in its absorption, distribution, and clearance, as well as possible drug-drug interactions.

The peanut lectin-binding glycoproteins of human epidermal keratinocytes

International Nuclear Information System (INIS)

Morrison, A.I.; Keeble, S.; Watt, F.M.

1988-01-01

The peanut lectin (PNA) is known to bind more strongly to keratinocytes that are undergoing terminal differentiation than to proliferating keratinocytes. In order to investigate the significance of this change in cell-surface carbohydrate authors have identified the PNA-binding glycoproteins of cultured human keratinocytes and antibodies against them. Two heavily glycosylated bands of 110 and 250 kDa were resolved by PAGE of [ 14 C]galactose- or [ 14 C]mannose- and [ 14 C]glucosamine-labeled cell extracts eluted with galactose from PNA affinity columns. The higher molecular weight band was also detected on PNA blots of unlabeled cell extracts transferred to nitrocellulose. Both bands were sensitive to pronase digestion, but only the 250-kDa band was digested with trypsin. A rabbit antiserum that we prepared (anti-PNA-gp) immunoprecipitated both bands from cell extracts. In contrast to PNA, anti-PNA-gp bound equally to proliferating and terminally differentiating cells, indicating that some epitope(s) of the PNA-binding glycoproteins is present on the cell surface prior to terminal differentiation. When keratinocytes grown as a monolayer in low-calcium medium were switched to medium containing 2 mM calcium ions in order to induce desmosome formation and stratification, there was a dramatic redistribution of the PNA-binding glycoproteins, which became concentrated at the boundaries between cells. This may suggest a role for the glycoproteins in cell-cell interactions during stratification

A Novel Method for Detection of Glycoproteins on Sodium Dodecyl Sulphate Polyacrylamide Gel Using Radio-Iodinated Tyrosine

DEFF Research Database (Denmark)

Nalla, Amarnadh; Draz, Hossam M.; Dole, Anita

2009-01-01

The aim of this study is to develop a novel method for detection of glycoproteins on polyacrylamide gel. In this method, radio-iodinated-tyrosine (125I-tyrosine) was conjugated to glycoprotein by schiff's base mechanism on the sodium dodecyl sulfate- polyacrylamide gel. Ovalbumin and Concanavalin...... of glycoproteins using 125I-tyrosine selectively detected ovalbumin. Present results showed that MPD enhanced glycoprotein detection method can be used as a sensitive tool for the detection of glycoproteins on polyacrylamide gel...

Digestive physiology of the pig symposium: secretion of gastrointestinal hormones and eating control.

Science.gov (United States)

Steinert, R E; Feinle-Bisset, C; Geary, N; Beglinger, C

2013-05-01

Nutrient ingestion triggers numerous changes in gastrointestinal (GI) peptide hormone secretion that affect appetite and eating. Evidence for these effects comes from research in laboratory animals, healthy humans, and, increasingly, obese patients after Roux-en-Y gastric bypass (RYGB) surgery, which has marked effects on GI hormone function and is currently the most effective therapy for morbid obesity. Increases in cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine tyrosine (PYY) and decreases in ghrelin secretion after meals are triggered by changes in the nutrient content of the intestine. One apparent physiological function of each is to initiate a reflex-like feedback control of eating. Here we briefly review this function, with an emphasis on the controls of their secretion. Each is secreted from enteroendocrine cells that are directly or indirectly affected by caloric load, macronutrient composition, and other characteristics of ingested food such as fatty acid chain length. In addition, digestive hydrolysis is a critical mechanism that controls their secretion. Although there are relatively few data in agricultural animals, the generally consistent results across widely divergent mammals suggests that most of the processes described are also likely to be relevant to GI hormone functions and eating in agricultural animals.

P-glycoprotein targeted nanoscale drug carriers

KAUST Repository

Li, Wengang; Abu Samra, Dina Bashir Kamil; Merzaban, Jasmeen; Khashab, Niveen M.

2013-01-01

Multi-drug resistance (MDR) is a trend whereby tumor cells exposed to one cytotoxic agent develop cross-resistance to a range of structurally and functionally unrelated compounds. P -glycoprotein (P -gp) efflux pump is one of the mostly studied drug

Multi-party semi-quantum key distribution-convertible multi-party semi-quantum secret sharing

Science.gov (United States)

Yu, Kun-Fei; Gu, Jun; Hwang, Tzonelih; Gope, Prosanta

2017-08-01

This paper proposes a multi-party semi-quantum secret sharing (MSQSS) protocol which allows a quantum party (manager) to share a secret among several classical parties (agents) based on GHZ-like states. By utilizing the special properties of GHZ-like states, the proposed scheme can easily detect outside eavesdropping attacks and has the highest qubit efficiency among the existing MSQSS protocols. Then, we illustrate an efficient way to convert the proposed MSQSS protocol into a multi-party semi-quantum key distribution (MSQKD) protocol. The proposed approach is even useful to convert all the existing measure-resend type of semi-quantum secret sharing protocols into semi-quantum key distribution protocols.

Multiple genes encode the major surface glycoprotein of Pneumocystis carinii

DEFF Research Database (Denmark)

Kovacs, J A; Powell, F; Edman, J C

1993-01-01

hydrophobic region at the carboxyl terminus. The presence of multiple related msg genes encoding the major surface glycoprotein of P. carinii suggests that antigenic variation is a possible mechanism for evading host defenses. Further characterization of this family of genes should allow the development......The major surface antigen of Pneumocystis carinii, a life-threatening opportunistic pathogen in human immunodeficiency virus-infected patients, is an abundant glycoprotein that functions in host-organism interactions. A monoclonal antibody to this antigen is protective in animals, and thus...... blot studies using chromosomal or restricted DNA, the major surface glycoproteins are the products of a multicopy family of genes. The predicted protein has an M(r) of approximately 123,000, is relatively rich in cysteine residues (5.5%) that are very strongly conserved, and contains a well conserved...

Pancreatic bicarbonate secretion involves two proton pumps.

Science.gov (United States)

Novak, Ivana; Wang, Jing; Henriksen, Katrine L; Haanes, Kristian A; Krabbe, Simon; Nitschke, Roland; Hede, Susanne E

2011-01-07

Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium express H(+)/HCO(3)(-) transporters, which depend on gradients created by the Na(+)/K(+)-ATPase. However, the model cannot fully account for high-bicarbonate concentrations, and other active transporters, i.e. pumps, have not been explored. Here we show that pancreatic ducts express functional gastric and non-gastric H(+)-K(+)-ATPases. We measured intracellular pH and secretion in small ducts isolated from rat pancreas and showed their sensitivity to H(+)-K(+) pump inhibitors and ion substitutions. Gastric and non-gastric H(+)-K(+) pumps were demonstrated on RNA and protein levels, and pumps were localized to the plasma membranes of pancreatic ducts. Quantitative analysis of H(+)/HCO(3)(-) and fluid transport shows that the H(+)-K(+) pumps can contribute to pancreatic secretion in several species. Our results call for revision of the bicarbonate transport physiology in pancreas, and most likely other epithelia. Furthermore, because pancreatic ducts play a central role in several pancreatic diseases, it is of high relevance to understand the role of H(+)-K(+) pumps in pathophysiology.

The glucagon-like peptide-1 metabolite GLP-1-(9-36) amide reduces postprandial glycemia independently of gastric emptying and insulin secretion in humans

DEFF Research Database (Denmark)

Meier, Juris J; Gethmann, Arnica; Nauck, Michael A

2006-01-01

Glucagon-like peptide 1 (GLP-1) lowers glycemia by modulating gastric emptying and endocrine pancreatic secretion. Rapidly after its secretion, GLP-1-(7-36) amide is degraded to the metabolite GLP-1-(9-36) amide. The effects of GLP-1-(9-36) amide in humans are less well characterized. Fourteen...... healthy volunteers were studied with intravenous infusion of GLP-1-(7-36) amide, GLP-1-(9-36) amide, or placebo over 390 min. After 30 min, a solid test meal was served, and gastric emptying was assessed. Blood was drawn for GLP-1 (total and intact), glucose, insulin, C-peptide, and glucagon measurements....... Administration of GLP-1-(7-36) amide and GLP-1-(9-36) amide significantly raised total GLP-1 plasma levels. Plasma concentrations of intact GLP-1 increased to 21 +/- 5 pmol/l during the infusion of GLP-1-(7-36) amide but remained unchanged during GLP-1-(9-36) amide infusion [5 +/- 3 pmol/l; P

Macrophage-mediated gliadin degradation and concomitant IL-27 production drive IL-10- and IFN-γ-secreting Tr1-like-cell differentiation in a murine model for gluten tolerance.

Science.gov (United States)

van Leeuwen, M A; Costes, L M M; van Berkel, L A; Simons-Oosterhuis, Y; du Pré, M F; Kozijn, A E; Raatgeep, H C; Lindenbergh-Kortleve, D J; van Rooijen, N; Koning, F; Samsom, J N

2017-05-01

Celiac disease is caused by inflammatory T-cell responses against the insoluble dietary protein gliadin. We have shown that, in humanized mice, oral tolerance to deamidated chymotrypsin-digested gliadin (CT-TG2-gliadin) is driven by tolerogenic interferon (IFN)-γ- and interleukin (IL)-10-secreting type 1 regulatory T-like cells (Tr1-like cells) generated in the spleen but not in the mesenteric lymph nodes. We aimed to uncover the mechanisms underlying gliadin-specific Tr1-like-cell differentiation and hypothesized that proteolytic gliadin degradation by splenic macrophages is a decisive step in this process. In vivo depletion of macrophages caused reduced differentiation of splenic IFN-γ- and IL-10-producing Tr1-like cells after CT-TG2-gliadin but not gliadin peptide feed. Splenic macrophages, rather than dendritic cells, constitutively expressed increased mRNA levels of the endopeptidase Cathepsin D; macrophage depletion significantly reduced splenic Cathepsin D expression in vivo and Cathepsin D efficiently degraded recombinant γ-gliadin in vitro. In response to CT-TG2-gliadin uptake, macrophages enhanced the expression of Il27p28, a cytokine that favored differentiation of gliadin-specific Tr1-like cells in vitro, and was previously reported to increase Cathepsin D activity. Conversely, IL-27 neutralization in vivo inhibited splenic IFN-γ- and IL-10-secreting Tr1-like-cell differentiation after CT-TG2-gliadin feed. Our data infer that endopeptidase mediated gliadin degradation by macrophages and concomitant IL-27 production drive differentiation of splenic gliadin-specific Tr1-like cells.

A catalogue of human secreted proteins and its implications

Directory of Open Access Journals (Sweden)

Shivakumar Keerthikumar

2016-11-01

Full Text Available Under both normal and pathological conditions, cells secrete variety of proteins through classical and non-classical secretory pathways into the extracellular space. Majority of these proteins represent pathophysiology of the cell from which it is secreted. Recently, though more than 92% of the protein coding genes has been mapped by human proteome map project, but number of those proteins that constitutes secretome of the cell still remains elusive. Secreted proteins or the secretome can be accessible in bodily fluids and hence are considered as potential biomarkers to discriminate between healthy and diseased individuals. In order to facilitate the biomarker discovery and to further aid clinicians and scientists working in these arenas, we have compiled and catalogued secreted proteins from the human proteome using integrated bioinformatics approach. In this study, nearly 14% of the human proteome is likely to be secreted through classical and non-classical secretory pathways. Out of which, ~38% of these secreted proteins were found in extracellular vesicles including exosomes and shedding microvesicles. Among these secreted proteins, 94% were detected in human bodily fluids including blood, plasma, serum, saliva, semen, tear and urine. We anticipate that this high confidence list of secreted proteins could serve as a compendium of candidate biomarkers. In addition, the catalogue may provide functional insights in understanding the molecular mechanisms involved in various physiological and pathophysiological conditions of the cell.

The O-Linked Glycome and Blood Group Antigens ABO on Mucin-Type Glycoproteins in Mucinous and Serous Epithelial Ovarian Tumors.

Directory of Open Access Journals (Sweden)

Varvara Vitiazeva

Full Text Available Mucins are heavily O-glycosylated proteins where the glycosylation has been shown to play an important role in cancer. Normal epithelial ovarian cells do not express secreted mucins, but their abnormal expression has previously been described in epithelial ovarian cancer and may relate to tumor formation and progression. The cyst fluids were shown to be a rich source for acidic glycoproteins. The study of these proteins can potentially lead to the identification of more effective biomarkers for ovarian cancer.In this study, we analyzed the expression of the MUC5AC and the O-glycosylation of acidic glycoproteins secreted into ovarian cyst fluids. The samples were obtained from patients with serous and mucinous ovarian tumors of different stages (benign, borderline, malignant and grades. The O-linked oligosaccharides were released and analyzed by negative-ion graphitized carbon Liquid Chromatography (LC coupled to Electrospray Ionization tandem Mass Spectrometry (ESI-MSn. The LC-ESI-MSn of the oligosaccharides from ovarian cyst fluids displayed differences in expression of fucose containing structures such as blood group ABO antigens and Lewis-type epitopes.The obtained data showed that serous and mucinous benign adenomas, mucinous low malignant potential carcinomas (LMPs, borderline and mucinous low-grade carcinomas have a high level of blood groups and Lewis type epitopes. In contrast, this type of fucosylated structures were low abundant in the high-grade mucinous carcinomas or in serous carcinomas. In addition, the ovarian tumors that showed a high level of expression of blood group antigens also revealed a strong reactivity towards the MUC5AC antibody. To visualize the differences between serous and mucinous ovarian tumors based on the O-glycosylation, a hierarchical cluster analysis was performed using mass spectrometry average compositions (MSAC.Mucinous benign and LMPs along with mucinous low-grade carcinomas appear to be different from

Glycoproteins of axonal transport: affinity chromatography on fucose-specific lectins

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, S.; Ohlson, C.; Karlsson, J.O.

1982-03-01

Rapidly transported fucose-labeled glycoproteins from axons of rabbit retinal ganglion cells were solubilized with nonionic detergents. The solubilized components were subjected to affinity chromatography on three different fucose-specific lectins. A recently characterized fucose-specific lectin from Aleuria aurantia bound reversibly approximately 60% of the applied protein-bound radioactivity. The lectins from Lotus tetragonolobus and Ulex europaeus bound are very small proportions of the labeled rapidly transported glycoproteins.

Enteroendocrine L Cells Sense LPS after Gut Barrier Injury to Enhance GLP-1 Secretion

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Lorène J. Lebrun

2017-10-01

Full Text Available Summary: Glucagon-like peptide 1 (GLP-1 is a hormone released from enteroendocrine L cells. Although first described as a glucoregulatory incretin hormone, GLP-1 also suppresses inflammation and promotes mucosal integrity. Here, we demonstrate that plasma GLP-1 levels are rapidly increased by lipopolysaccharide (LPS administration in mice via a Toll-like receptor 4 (TLR4-dependent mechanism. Experimental manipulation of gut barrier integrity after dextran sodium sulfate treatment, or via ischemia/reperfusion experiments in mice, triggered a rapid rise in circulating GLP-1. This phenomenon was detected prior to measurable changes in inflammatory status and plasma cytokine and LPS levels. In human subjects, LPS administration also induced GLP-1 secretion. Furthermore, GLP-1 levels were rapidly increased following the induction of ischemia in the human intestine. These findings expand traditional concepts of enteroendocrine L cell biology to encompass the sensing of inflammatory stimuli and compromised mucosal integrity, linking glucagon-like peptide secretion to gut inflammation. : Lebrun et al. demonstrate that enteroendocrine L cells sense lipopolysaccharides (pro-inflammatory bacterial compounds after gut injury and respond by secreting glucagon-like peptide 1. These findings expand concepts of L cell function to include roles as both a nutrient and pathogen sensor, linking glucagon-like peptide secretion to gut inflammation. Keywords: glucagon-like peptide 1, lipopolysaccharides, enteroendocrine cells, TLR4, gut injury, intestinal ischemia, inflammation

The role of somatostatin in GLP-1-induced inhibition of glucagon secretion in mice

DEFF Research Database (Denmark)

Ørgaard, Anne; Holst, Jens J

2017-01-01

AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) receptor agonists are currently used for the treatment of type 2 diabetes. Their main mechanism of action is enhancement of glucose-induced insulin secretion (from increased beta cell glucose sensitivity) and inhibition of glucagon secretion...... on glucagon secretion is heavily debated. Glucagon inhibition is also said to be glucose-dependent, although it is unclear what is meant by this. We hypothesise here that GLP-1 does not inhibit glucagon secretion during hypoglycaemia because the inhibition depends on somatostatin secretion, which in turn...

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

Directory of Open Access Journals (Sweden)

Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Secreted Clusterin protein inhibits osteoblast differentiation of bone marrow mesenchymal stem cells by suppressing ERK1/2 signaling pathway.

Science.gov (United States)

Abdallah, Basem M; Alzahrani, Abdullah M; Kassem, Moustapha

2018-05-01

Secreted Clusterin (sCLU, also known as Apolipoprotein J) is an anti-apoptotic glycoprotein involved in the regulation of cell proliferation, lipid transport, extracellular tissue remodeling and apoptosis. sCLU is expressed and secreted by mouse bone marrow-derived skeletal (stromal or mesenchymal) stem cells (mBMSCs), but its functional role in MSC biology is not known. In this study, we demonstrated that Clusterin mRNA expression and protein secretion in conditioned medium increased during adipocyte differentiation and decreased during osteoblast differentiation of mBMSCs. Treatment of mBMSC cultures with recombinant sCLU protein increased cell proliferation and exerted an inhibitory effect on the osteoblast differentiation while stimulated adipocyte differentiation in a dose-dependent manner. siRNA-mediated silencing of Clu expression in mBMSCs reduced adipocyte differentiation and stimulated osteoblast differentiation of mBMSCs. Furthermore, the inhibitory effect of sCLU on the osteoblast differentiation of mBMSCs was mediated by the suppression of extracellular signal-regulated kinase (ERK1/2) phosphorylation. In conclusion, we identified sCLU as a regulator of mBMSCs lineage commitment to osteoblasts versus adipocytes through a mechanism mediated by ERK1/2 signaling. Inhibiting sCLU is a possible therapeutic approach for enhancing osteoblast differentiation and consequently bone formation. Copyright © 2018 Elsevier Inc. All rights reserved.

Authentication Without Secrets

Energy Technology Data Exchange (ETDEWEB)

Pierson, Lyndon G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-11-01

This work examines a new approach to authentication, which is the most fundamental security primitive that underpins all cyber security protections. Current Internet authentication techniques require the protection of one or more secret keys along with the integrity protection of the algorithms/computations designed to prove possession of the secret without actually revealing it. Protecting a secret requires physical barriers or encryption with yet another secret key. The reason to strive for "Authentication without Secret Keys" is that protecting secrets (even small ones only kept in a small corner of a component or device) is much harder than protecting the integrity of information that is not secret. Promising methods are examined for authentication of components, data, programs, network transactions, and/or individuals. The successful development of authentication without secret keys will enable far more tractable system security engineering for high exposure, high consequence systems by eliminating the need for brittle protection mechanisms to protect secret keys (such as are now protected in smart cards, etc.). This paper is a re-release of SAND2009-7032 with new figures numerous edits.

Regulation of gut hormone secretion. Studies using isolated perfused intestines

DEFF Research Database (Denmark)

Svendsen, Berit; Holst, Jens Juul.

2016-01-01

hormones is highly increased after gastric bypass operations, which have turned out to be an effective therapy of not only obesity but also type 2 diabetes. These effects are likely to be due, at least in part, to increases in the secretion of these gut hormones (except GIP). Therefore, stimulation...... of the endogenous hormone represents an appealing therapeutic strategy, which has spurred an interest in understanding the regulation of gut hormone secretion and a search for particularly GLP-1 and PYY secretagogues. The secretion of the gut hormones is stimulated by oral intake of nutrients often including...

Expression and functional study of extracellular BMP antagonists during the morphogenesis of the digits and their associated connective tissues.

Directory of Open Access Journals (Sweden)

Carlos I Lorda-Diez

Full Text Available The purpose of this study is to gain insight into the role of BMP signaling in the diversification of the embryonic limb mesodermal progenitors destined to form cartilage, joints, and tendons. Given the importance of extracellular BMP modulators in in vivo systems, we performed a systematic search of those expressed in the developing autopod during the formation of the digits. Here, we monitored the expression of extracellular BMP modulators including: Noggin, Chordin, Chordin-like 1, Chordin-like 2, Twisted gastrulation, Dan, BMPER, Sost, Sostdc1, Follistatin, Follistatin-like 1, Follistatin-like 5 and Tolloid. These factors show differential expression domains in cartilage, joints and tendons. Furthermore, they are induced in specific temporal patterns during the formation of an ectopic extra digit, preceding the appearance of changes that are identifiable by conventional histology. The analysis of gene regulation, cell proliferation and cell death that are induced by these factors in high density cultures of digit progenitors provides evidence of functional specialization in the control of mesodermal differentiation but not in cell proliferation or apoptosis. We further show that the expression of these factors is differentially controlled by the distinct signaling pathways acting in the developing limb at the stages covered by this study. In addition, our results provide evidence suggesting that TWISTED GASTRULATION cooperates with CHORDINS, BMPER, and NOGGIN in the establishment of tendons or cartilage in a fashion that is dependent on the presence or absence of TOLLOID.

Insulin-like growth factor-I and insulin-like growth factor binding proteins in the bovine mammary gland: Receptors, endogenous secretion, and appearance in milk

International Nuclear Information System (INIS)

Campbell, P.G.

1988-01-01

This is the first study to characterize both insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) in bovine milk, to characterize the IGF-I receptor in the dry and lactating mammary gland, and to report de novo synthesis and secretion of IGF-I and IGFBP from normal mammary tissue. Immunoreactive IGF-I was principally associated with 45 kDa IGFBP in milk. Multiparous cows had a higher IGF-I concentration of 307 ng/ml than primiparous cows at 147 ng/ml. IGF-I concentration on day 56 of lactation was 34 ng/ml for combined parity groups. At parturition, IGF-I mass in blood and milk pools was 1.4 and 1.2 mg, respectively. Binding of 125 I-IGF-I was specific for IGF-I with anIC 50 of 2.2 ng which was a 10- and 1273-fold greater affinity than IGF-II and insulin, respectively. Association constants, as determined by Scatchard analysis, were similar for both pregnant and lactating cows at 3.5 and 4.0 L/nM, respectively. In addition, estimated mean receptor concentration was 0.25 and 0.23 pM/mg protein for pregnant and lactating cows, respectively. In a survey of mammary microscomes prepared from 48 cows, 125 I-IGF-I binding declined with progressing lactation and a similar trend was observed during pregnancy

Preparation of 131I-asialo-α1-acid glycoprotein

International Nuclear Information System (INIS)

Rijk, P.P. van

1975-01-01

α 1 -Acid glycoprotein (orosomucoid) was prepared from a byproduct of the ethanol plasma fractionation by means of ion-exchange procedures. Immunoelectrophoresis suggested a high degree of purity; the purified protein contained 13.5% sialic acid and 17.8% hexose. The α 1 -acid glycoprotein was modified by removal of sialic acid with neurominidase (E.C. 3.2.1.18) followed by iodination with 131 I. The purpose of the preparation, its potential use as a pharmacon for liver-function studies in nuclear medicine, is the subject of further study

Nipah virus infection and glycoprotein targeting in endothelial cells

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Maisner Andrea

2010-11-01

Full Text Available Abstract Background The highly pathogenic Nipah virus (NiV causes fatal respiratory and brain infections in animals and humans. The major hallmark of the infection is a systemic endothelial infection, predominantly in the CNS. Infection of brain endothelial cells allows the virus to overcome the blood-brain-barrier (BBB and to subsequently infect the brain parenchyma. However, the mechanisms of NiV replication in endothelial cells are poorly elucidated. We have shown recently that the bipolar or basolateral expression of the NiV surface glycoproteins F and G in polarized epithelial cell layers is involved in lateral virus spread via cell-to-cell fusion and that correct sorting depends on tyrosine-dependent targeting signals in the cytoplasmic tails of the glycoproteins. Since endothelial cells share many characteristics with epithelial cells in terms of polarization and protein sorting, we wanted to elucidate the role of the NiV glycoprotein targeting signals in endothelial cells. Results As observed in vivo, NiV infection of endothelial cells induced syncytia formation. The further finding that infection increased the transendothelial permeability supports the idea of spread of infection via cell-to-cell fusion and endothelial cell damage as a mechanism to overcome the BBB. We then revealed that both glycoproteins are expressed at lateral cell junctions (bipolar, not only in NiV-infected primary endothelial cells but also upon stable expression in immortalized endothelial cells. Interestingly, mutation of tyrosines 525 and 542/543 in the cytoplasmic tail of the F protein led to an apical redistribution of the protein in endothelial cells whereas tyrosine mutations in the G protein had no effect at all. This fully contrasts the previous results in epithelial cells where tyrosine 525 in the F, and tyrosines 28/29 in the G protein were required for correct targeting. Conclusion We conclude that the NiV glycoprotein distribution is responsible for

Strategies To Keep Secret Through Sophie Kinsella’s Novel “Can You Keep A Secret”

OpenAIRE

Sihombing, Mariaty A.

2015-01-01

The paper entitled “Strategies to Keep Secret Through Sophie Kinsella’a novel : Can You Keep a Secret is about Emma Corrigan who like every girl in the world. She has a few little secrets. Can You Keep a Secret is the fifth novel that written by Sophie Kinsella and get best seller. The writer discusses about the strategies to keep secret. The strategies are Trust, Silence, and Cooperation. The writer interested in analyzing this novel, because it’s contain some informantions about keeping a s...

Isolation of glycoproteins from brown algae

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

International Nuclear Information System (INIS)

Leberer, E.; Charuk, J.H.M.; MacLennan, D.H.; Green, N.M.

1989-01-01

Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1,308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH 2 -terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca 2+ . The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45 C 2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca 2+ with the membrane. The authors propose that this lumenal Ca 2+ binding glycoprotein of the sarcoplasmic reticulum be designated sarcalumenin

Fusion of raft-like lipid bilayers operated by a membranotropic domain of the HSV-type I glycoprotein gH occurs through a cholesterol-dependent mechanism.

Science.gov (United States)

Vitiello, Giuseppe; Falanga, Annarita; Petruk, Ariel Alcides; Merlino, Antonello; Fragneto, Giovanna; Paduano, Luigi; Galdiero, Stefania; D'Errico, Gerardino

2015-04-21

A wealth of evidence indicates that lipid rafts are involved in the fusion of the viral lipid envelope with the target cell membrane. However, the interplay between these sterol- and sphingolipid-enriched ordered domains and viral fusion glycoproteins has not yet been clarified. In this work we investigate the molecular mechanism by which a membranotropic fragment of the glycoprotein gH of the Herpes Simplex Virus (HSV) type I (gH625) drives fusion of lipid bilayers formed by palmitoyl oleoyl phosphatidylcholine (POPC)-sphingomyelin (SM)-cholesterol (CHOL) (1 : 1 : 1 wt/wt/wt), focusing on the role played by each component. The comparative analysis of the liposome fusion assays, Dynamic Light Scattering (DLS), spectrofluorimetry, Neutron Reflectivity (NR) and Electron Spin Resonance (ESR) experiments, and Molecular Dynamics (MD) simulations shows that CHOL is fundamental for liposome fusion to occur. In detail, CHOL stabilizes the gH625-bilayer association by specific interactions with the peptide Trp residue. The interaction with gH625 causes an increased order of the lipid acyl chains, whose local rotational motion is significantly hampered. SM plays only a minor role in the process, favoring the propagation of lipid perturbation to the bilayer inner core. The stiffening of the peptide-interacting bilayer leaflet results in an asymmetric perturbation of the membrane, which is locally destabilized thus favoring fusion events. Our results show that viral fusion glycoproteins are optimally suited to exert a high fusogenic activity on lipid rafts and support the relevance of cholesterol as a key player of membrane-related processes.

Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

International Nuclear Information System (INIS)

Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D.

1989-01-01

Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the α-glucosidase amyloglucosidase (50% inhibition at 5.8 μM), but it did not inhibit β-glucosidase, α- or β-mannosidase, or α- or β-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc 3 Man 7-9 (GlcNAc) 2 -oligosaccharides

Statins Suppress Ebola Virus Infectivity by Interfering with Glycoprotein Processing.

Science.gov (United States)

Shrivastava-Ranjan, Punya; Flint, Mike; Bergeron, Éric; McElroy, Anita K; Chatterjee, Payel; Albariño, César G; Nichol, Stuart T; Spiropoulou, Christina F

2018-05-01

Ebola virus (EBOV) infection is a major public health concern due to high fatality rates and limited effective treatments. Statins, widely used cholesterol-lowering drugs, have pleiotropic mechanisms of action and were suggested as potential adjunct therapy for Ebola virus disease (EVD) during the 2013-2016 outbreak in West Africa. Here, we evaluated the antiviral effects of statin (lovastatin) on EBOV infection in vitro Statin treatment decreased infectious EBOV production in primary human monocyte-derived macrophages and in the hepatic cell line Huh7. Statin treatment did not interfere with viral entry, but the viral particles released from treated cells showed reduced infectivity due to inhibition of viral glycoprotein processing, as evidenced by decreased ratios of the mature glycoprotein form to precursor form. Statin-induced inhibition of infectious virus production and glycoprotein processing was reversed by exogenous mevalonate, the rate-limiting product of the cholesterol biosynthesis pathway, but not by low-density lipoprotein. Finally, statin-treated cells produced EBOV particles devoid of the surface glycoproteins required for virus infectivity. Our findings demonstrate that statin treatment inhibits EBOV infection and suggest that the efficacy of statin treatment should be evaluated in appropriate animal models of EVD. IMPORTANCE Treatments targeting Ebola virus disease (EVD) are experimental, expensive, and scarce. Statins are inexpensive generic drugs that have been used for many years for the treatment of hypercholesterolemia and have a favorable safety profile. Here, we show the antiviral effects of statins on infectious Ebola virus (EBOV) production. Our study reveals a novel molecular mechanism in which statin regulates EBOV particle infectivity by preventing glycoprotein processing and incorporation into virus particles. Additionally, statins have anti-inflammatory and immunomodulatory effects. Since inflammation and dysregulation of the immune

Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junin arenavirus envelope glycoprotein

International Nuclear Information System (INIS)

York, Joanne; Agnihothram, Sudhakar S.; Romanowski, Victor; Nunberg, Jack H.

2005-01-01

The G2 fusion subunit of the Junin virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever

Influence of Flavonoids on Mechanism of Modulation of Insulin Secretion.

Science.gov (United States)

Soares, Juliana Mikaelly Dias; Pereira Leal, Ana Ediléia Barbosa; Silva, Juliane Cabral; Almeida, Jackson R G S; de Oliveira, Helinando Pequeno

2017-01-01

-dependent protein kinase II, GSIS: Glucose-stimulated insulin secretion, Insig-1: Insulin-induced gene 1, IRS-2: Insulin receptor substrate 2, PDX-1: Pancreatic and duodenal homeobox 1, SREBP-1c: Sterol regulatory element binding protein-1c, DMC: Dihydroxy-6'-methoxy-3',5'-dimethylchalcone, GLP-1: Glucagon-like peptide-1, GLP-1R: Glucagon-like peptide 1 receptor.

Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

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Yadvinder S. Ahi

2016-11-01

Full Text Available Gammaretroviruses, such as murine leukemia viruses (MLVs, encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag. MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes.

The expression and serological reactivity of recombinant canine herpesvirus 1 glycoprotein D

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MarkéŽta Vaňkov‡á

2016-01-01

Full Text Available The aim of this work was to express recombinant glycoprotein D of canine herpesvirus 1 in bacterial cells and to evaluate its diagnostic sensitivity and specificity when compared to traditional serological methods. The gene fragment coding glycoprotein D of canine herpesvirus 1 was amplified by polymerase chain reaction, cloned into plasmid vector and expressed in Escherichia coli cells. Recombinant protein was then purified and used as an antigen in immunoblot for a detection of canine herpesvirus 1 specific antibodies. Antibody testing was performed on the panel of 100 canine sera by immunoblot with recombinant glycoprotein D as antigen and compared with indirect immunofluorescence assay. Serum samples were collected from 83 dogs with no history of canine herpesvirus 1 or reproductive disorders, and from 17 dogs from breeding kennels with a history of canine herpesvirus 1 related reproductive disorders. Sensitivity of glycoprotein D based immunoblot was 89.2% and specificity was 93%. Kappa value was calculated to be 0.8 between immunoblot and indirect immunofluorescence assay. Antibodies against canine herpesvirus 1 infection were detected in 33% of samples by immunoblot assay. Our study confirms that recombinant glycoprotein D expressed in bacterial cells could be used as a suitable and sensitive antigen for immunological tests and that herpesvirus infection seems to be common among the canine population in the Czech Republic.

Global site-specific analysis of glycoprotein N-glycan processing.

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Cao, Liwei; Diedrich, Jolene K; Ma, Yuanhui; Wang, Nianshuang; Pauthner, Matthias; Park, Sung-Kyu Robin; Delahunty, Claire M; McLellan, Jason S; Burton, Dennis R; Yates, John R; Paulson, James C

2018-06-01

N-glycans contribute to the folding, stability and functions of the proteins they decorate. They are produced by transfer of the glycan precursor to the sequon Asn-X-Thr/Ser, followed by enzymatic trimming to a high-mannose-type core and sequential addition of monosaccharides to generate complex-type and hybrid glycans. This process, mediated by the concerted action of multiple enzymes, produces a mixture of related glycoforms at each glycosite, making analysis of glycosylation difficult. To address this analytical challenge, we developed a robust semiquantitative mass spectrometry (MS)-based method that determines the degree of glycan occupancy at each glycosite and the proportion of N-glycans processed from high-mannose type to complex type. It is applicable to virtually any glycoprotein, and a complete analysis can be conducted with 30 μg of protein. Here, we provide a detailed description of the method that includes procedures for (i) proteolytic digestion of glycoprotein(s) with specific and nonspecific proteases; (ii) denaturation of proteases by heating; (iii) sequential treatment of the glycopeptide mixture with two endoglycosidases, Endo H and PNGase F, to create unique mass signatures for the three glycosylation states; (iv) LC-MS/MS analysis; and (v) data analysis for identification and quantitation of peptides for the three glycosylation states. Full coverage of site-specific glycosylation of glycoproteins is achieved, with up to thousands of high-confidence spectra hits for each glycosite. The protocol can be performed by an experienced technician or student/postdoc with basic skills for proteomics experiments and takes ∼7 d to complete.

Dynamics of synthetic activity of RNA and glycoproteins in epithel cells of endometrium in heifers after ovulation

International Nuclear Information System (INIS)

Pivko, J.; Grafenau, P.; Uhrin, V.; Kopecny, V.

1998-01-01

represented in the supranuclear parts. Intensive synthesis takes place in cells of glands of the functional zone on 3rd day, the intensity of the reaction is lower in the basal zone. The creation of glycoproteins is identical in surface as well as in deep parts of glands on 6th day, it declines in the surface parts on 9th day, whereas it remains on the same level in other parts. The intensive RNA synthesis was sustained in nuclei of epithel cells of uterus in luminal and glandular epithel. The synthetic and secretion activities of glycoproteins are intensive in the luteal phase, they decrease slightly in surface cells of glands white they are preserved in the deep cells

Analytical Pipeline for Discovery and Verification of Glycoproteins from Plasma-Derived Extracellular Vesicles as Breast Cancer Biomarkers.

Science.gov (United States)

Chen, I-Hsuan; Aguilar, Hillary Andaluz; Paez Paez, J Sebastian; Wu, Xiaofeng; Pan, Li; Wendt, Michael K; Iliuk, Anton B; Zhang, Ying; Tao, W Andy

2018-05-15

Glycoproteins comprise more than half of current FDA-approved protein cancer markers, but the development of new glycoproteins as disease biomarkers has been stagnant. Here we present a pipeline to develop glycoproteins from extracellular vesicles (EVs) through integrating quantitative glycoproteomics with a novel reverse phase glycoprotein array and then apply it to identify novel biomarkers for breast cancer. EV glycoproteomics show promise in circumventing the problems plaguing current serum/plasma glycoproteomics and allowed us to identify hundreds of glycoproteins that have not been identified in blood. We identified 1,453 unique glycopeptides representing 556 glycoproteins in EVs, among which 20 were verified significantly higher in individual breast cancer patients. We further applied a novel glyco-specific reverse phase protein array to quantify a subset of the candidates. Together, this study demonstrates the great potential of this integrated pipeline for biomarker discovery.

Secreted osteopontin is highly polymerized in human airways and fragmented in asthmatic airway secretions.

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Mehrdad Arjomandi

Full Text Available Osteopontin (OPN is a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING family and a cytokine with diverse biologic roles. OPN undergoes extensive post-translational modifications, including polymerization and proteolytic fragmentation, which alters its biologic activity. Recent studies suggest that OPN may contribute to the pathogenesis of asthma.To determine whether secreted OPN (sOPN is polymerized in human airways and whether it is qualitatively different in asthma, we used immunoblotting to examine sOPN in bronchoalveolar lavage (BAL fluid samples from 12 healthy and 21 asthmatic subjects (and in sputum samples from 27 healthy and 21 asthmatic subjects. All asthmatic subjects had mild to moderate asthma and abstained from corticosteroids during the study. Furthermore, we examined the relationship between airway sOPN and cellular inflammation.We found that sOPN in BAL fluid and sputum exists in polymeric, monomeric, and cleaved forms, with most of it in polymeric form. Compared to healthy subjects, asthmatic subjects had proportionately less polymeric sOPN and more monomeric and cleaved sOPN. Polymeric sOPN in BAL fluid was associated with increased alveolar macrophage counts in airways in all subjects.These results suggest that sOPN in human airways (1 undergoes extensive post-translational modification by polymerization and proteolytic fragmentation, (2 is more fragmented and less polymerized in subjects with mild to moderate asthma, and (3 may contribute to recruitment or survival of alveolar macrophages.

Homologous and heterologous antibody responses of mice immunized with purified feline herpesvirus type 1 and canine herpesvirus glycoproteins.

Science.gov (United States)

Limcumpao, J A; Horimoto, T; Xuan, X N; Tohya, Y; Azetaka, M; Takahashi, E; Mikami, T

1991-06-01

The three glycoproteins each of feline herpesvirus type 1 (FHV-1) and canine herpesvirus (CHV) were purified by affinity chromatography using glycoprotein-specific monoclonal antibodies and used individually or in combination in immunizing mice to determine their relative immunogenicity. All the glycoproteins induced detectable virus neutralizing antibodies to the homologous virus but FHV-1 gp143/108 and its cross-reacting counterpart, CHV gp145/112, elicited the highest titers not only to the homologous virus but to the heterologous virus as well. The production of ELISA antibodies after glycoprotein immunization was variable, while hemagglutination-inhibiting antibodies were produced by only 1 out of 10 FHV-1 gp60-inoculated mice. In general, the antibody titers induced by CHV glycoproteins were lower than those by FHV-1 glycoproteins. These results indicate that these glycoproteins may be useful as subunit vaccines against FHV-1 and CHV infections.

Expression of the chitinase family glycoprotein YKL-40 in undifferentiated, differentiated and trans-differentiated mesenchymal stem cells.

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Daniel J Hoover

Full Text Available The glycoprotein YKL-40 (CHI3L1 is a secreted chitinase family protein that induces angiogenesis, cell survival, and cell proliferation, and plays roles in tissue remodeling and immune regulation. It is expressed primarily in cells of mesenchymal origin, is overexpressed in numerous aggressive carcinomas and sarcomas, but is rarely expressed in normal ectodermal tissues. Bone marrow-derived mesenchymal stem cells (MSCs can be induced to differentiate into various mesenchymal tissues and trans-differentiate into some non-mesenchymal cell types. Since YKL-40 has been used as a mesenchymal marker, we followed YKL-40 expression as undifferentiated MSCs were induced to differentiate into bone, cartilage, and neural phenotypes. Undifferentiated MSCs contain significant levels of YKL-40 mRNA but do not synthesize detectable levels of YKL-40 protein. MSCs induced to differentiate into chondrocytes and osteocytes soon began to express and secrete YKL-40 protein, as do ex vivo cultured chondrocytes and primary osteocytes. In contrast, MSCs induced to trans-differentiate into neurons did not synthesize YKL-40 protein, consistent with the general absence of YKL-40 protein in normal CNS parenchyma. However, these trans-differentiated neurons retained significant levels of YKL-40 mRNA, suggesting the mechanisms which prevented YKL-40 translation in undifferentiated MSCs remained in place, and that these trans-differentiated neurons differ in at least this way from neurons derived from neuronal stem cells. Utilization of a differentiation protocol containing β-mercaptoethanol resulted in cells that expressed significant amounts of intracellular YKL-40 protein that was not secreted, which is not seen in normal cells. Thus the synthesis of YKL-40 protein is a marker for MSC differentiation into mature mesenchymal phenotypes, and the presence of untranslated YKL-40 mRNA in non-mesenchymal cells derived from MSCs reflects differences between differentiated and

Bioactivity of proteins isolated from Lactobacillus plantarum L67 treated with Zanthoxylum piperitum DC glycoprotein.

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Song, S; Oh, S; Lim, K-T

2015-06-01

Lactobacilli in the human gastrointestinal tract have beneficial effects on the health of their host. To enhance these effects, the bioactivity of lactobacilli can be fortified through exogenous dietary or pharmacological agents, such as glycoproteins. To elucidate the inductive effect of Zanthoxylum piperitum DC (ZPDC) glycoprotein on Lactobacillus plantarum L67, we evaluated the radical-scavenging activity, anti-oxidative enzymes (SOD, GPx and CAT), growth rate, ATPase activity and β-galactosidase activity of this strain. When Lact. plantarum L67 was treated with ZPDC glycoprotein at different concentrations, the intensities of a few SDS-PAGE bands were slightly changed. The amount of a 23 kDa protein was increased upon treatment with increasing concentrations of ZPDC glycoprotein. The results of this study indicate that the radical-scavenging activity for O2(-) and OH¯, but not for the DPPH radical, increased in a concentration-dependent manner after treatment with ZPDC glycoprotein. The activation of anti-oxidative enzymes (SOD, GPx and CAT), growth rate and β-galactosidase activity also increased in a concentration-dependent manner in response to ZPDC glycoprotein treatment, whereas ATPase activity was decreased. In summary, ZPDC glycoprotein stimulated an increase in the bioactivity of Lact. plantarum L67. Significance and impact of the study: This study demonstrated that Lactobacillus plantarum L67 possesses anti-oxidative activity. This strain of lactic bacteria has been known to have various probiotic uses, such as yogurt starters and dietary additional supplements. We found, through this experiment, that the protein has a strong anti-oxidative character, and the activity can be enhanced by treatment with Zanthoxylum piperitum DC (ZPDC) glycoprotein. This study may be application of Lact. plantarum L67 treated by ZPDC glycoprotein in yogurt fermentation. It could be one of the avenues of minimizing yogurt postacidification during storage. In addition

Delta-like Ligand-4-Notch Signaling Inhibition Regulates Pancreatic Islet Function and Insulin Secretion

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Fabienne Billiard

2018-01-01

Full Text Available Although Notch signaling has been proposed as a therapeutic target for type-2 diabetes, liver steatosis, and atherosclerosis, its direct effect on pancreatic islets remains unknown. Here, we demonstrated a function of Dll4-Notch signaling inhibition on the biology of insulin-producing cells. We confirmed enhanced expression of key Notch signaling genes in purified pancreatic islets from diabetic NOD mice and showed that treatment with anti-Dll4 antibody specifically abolished Notch signaling pathway activation. Furthermore, we showed that Notch inhibition could drive proliferation of β-islet cells and confer protection from the development of STZ-induced diabetes. Importantly, inhibition of the Dll4 pathway in WT mice increased insulin secretion by inducing the differentiation of pancreatic β-islet cell progenitors, as well as the proliferation of insulin-secreting cells. These findings reveal a direct effect of Dll4-blockade on pancreatic islets that, in conjunction with its immunomodulatory effects, could be used for unmet medical needs hallmarked by inefficient insulin action.

The haemagglutination activity of equine herpesvirus type 1 glycoprotein C.

Science.gov (United States)

Andoh, Kiyohiko; Hattori, Shiho; Mahmoud, Hassan Y A H; Takasugi, Maaya; Shimoda, Hiroshi; Bannai, Hiroshi; Tsujimura, Koji; Matsumura, Tomio; Kondo, Takashi; Kirisawa, Rikio; Mochizuki, Masami; Maeda, Ken

2015-01-02

Equine herpesvirus type 1 (EHV-1) has haemagglutination (HA) activity toward equine red blood cells (RBCs), but the identity of its haemagglutinin is unknown. To identify the haemagglutinin of EHV-1, the major glycoproteins of EHV-1 were expressed in 293T cells, and the cells or cell lysates were mixed with equine RBCs. The results showed that only EHV-1 glycoprotein C (gC)-producing cells adsorbed equine RBCs, and that the lysate of EHV-1 gC-expressing cells agglutinated equine RBCs. EHV-1 lacking gC did not show HA activity. HA activity was inhibited by monoclonal antibodies (MAbs) specific for gC, but not by antibodies directed against other glycoproteins. In addition, HA activity was not inhibited by the addition of heparin. These results indicate that EHV-1 gC can bind equine RBCs irrespective of heparin, in contrast to other herpesvirus gC proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

Energy Technology Data Exchange (ETDEWEB)

Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D. (Univ. of Texas Health Science Center, San Antonio (USA))

1989-03-07

Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the {alpha}-glucosidase amyloglucosidase (50% inhibition at 5.8 {mu}M), but it did not inhibit {beta}-glucosidase, {alpha}- or {beta}-mannosidase, or {alpha}- or {beta}-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc{sub 3}Man{sub 7-9}(GlcNAc){sub 2}-oligosaccharides.

Amino acid differences in glycoproteins B (gB, C (gC, H (gH and L(gL are associated with enhanced herpes simplex virus type-1 (McKrae entry via the paired immunoglobulin-like type-2 receptor α

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Chowdhury Sona

2012-06-01

Full Text Available Abstract Background Herpes simplex virus type-1 (HSV-1 enters into cells via membrane fusion of the viral envelope with plasma or endosomal membranes mediated by viral glycoproteins. HSV-1 virions attach to cell surfaces by binding of viral glycoproteins gC, gD and gB to specific cellular receptors. Here we show that the human ocular and highly neurovirulent HSV-1 strain McKrae enters substantially more efficiently into cells via the gB-specific human paired immunoglobulin-like type-2 receptor-α (hPILR-α. Comparison of the predicted amino acid sequences between HSV-1(F and McKrae strains indicates that amino acid changes within gB, gC, gH and gL may cause increased entry via the hPILR- α receptor. Results HSV-1 (McKrae entered substantially more efficiently than viral strain F in Chinese hamster ovary (CHO cells expressing hPIRL-α but not within CHO-human nectin-1, -(CHO-hNectin-1, CHO-human HVEM (CHO-hHVEM or Vero cells. The McKrae genes encoding viral glycoproteins gB, gC, gD, gH, gL, gK and the membrane protein UL20 were sequenced and their predicted amino acid (aa sequences were compared with virulent strains F, H129, and the attenuated laboratory strain KOS. Most aa differences between McKrae and F were located at their gB amino termini known to bind with the PILRα receptor. These aa changes included a C10R change, also seen in the neurovirulent strain ANG, as well as redistribution and increase of proline residues. Comparison of gC aa sequences revealed multiple aa changes including an L132P change within the 129-247 aa region known to bind to heparan sulfate (HS receptors. Two aa changes were located within the H1 domain of gH that binds gL. Multiple aa changes were located within the McKrae gL sequence, which were preserved in the H129 isolate, but differed for the F strain. Viral glycoproteins gD and gK and the membrane protein UL20 were conserved between McKrae and F strains. Conclusions The results indicate that the observed

The effect of P-glycoprotein on methadone hydrochloride flux in equine intestinal mucosa.

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Linardi, R L; Stokes, A M; Andrews, F M

2013-02-01

Methadone is an effective analgesic opioid that may have a place for the treatment of pain in horses. However, its absorption seems to be impaired by the presence of a transmembrane protein, P-glycoprotein, present in different tissues including the small intestine in other species. This study aims to determine the effect of the P-glycoprotein on methadone flux in the equine intestinal mucosa, as an indicator of in vivo drug absorption. Jejunum tissues from five horses were placed into the Ussing chambers and exposed to methadone solution in the presence or absence of Rhodamine 123 or verapamil. Electrical measurements demonstrated tissue viability for 120 min, and the flux of methadone across the jejunal membrane (mucosal to submucosal direction) was calculated based on the relative drug concentration measured by ELISA. The flux of methadone was significantly higher only in the presence of verapamil. P-glycoprotein was immunolocalized in the apical membrane of the jejunal epithelial cells (enterocytes), mainly located in the tip of the villi compared to cells of the crypts. P-glycoprotein is present in the equine jejunum and may possibly mediate the intestinal transport of methadone. This study suggests that P-glycoprotein may play a role in the poor intestinal absorption of methadone in vivo. © 2012 Blackwell Publishing Ltd.

[Pregnancy-specific beta-glycoprotein in the serum of women with a complicated early pregnancy].

Science.gov (United States)

Radikov, N

1989-01-01

The author determined pregnancy specific beta 1-glycoprotein in 109 women with threatened early pregnancy as 32 of the women suffered from abortus imminens with several unsuccessful pregnancies in the past as well as 67 women with abortus incipiens with bleeding ex utero. The author established that 87% of women with abortus imminens and preserved pregnancies had values of beta 1-glycoprotein close to those of normal pregnancy for the respective gestational week. 93% of women with abortus incipiens preserved pregnancies till term, but the specific glycoprotein was with in normal ranges. Spontaneous abortion occurred in 7% of women with low values under the 10th percentile. The present study show that examination of pregnancy specific beta 1-glycoprotein in women with threatened early pregnancy is of prognostic significance for the outcome of pregnancy.

Study on the extraction and purification of glycoprotein from the yellow seahorse, Hippocampus kuda Bleeker

Science.gov (United States)

Su, Yuting; Xu, Yongjian

2015-01-01

The optimum parameters of extraction for glycoprotein from seahorse were examined and determined by Box-Behnken combined with ultrasonic extraction technology. Column chromatography of glycoprotein was used for further purification. The optimal extraction conditions of seahorse glycoprotein were extracting time 4.3 h, salt concentration 0.08 mol/L, extracting temperature 73°C, raw material, and water ratio 1:6. At the optimal conditions, the yield of saccharide reached to 1.123%, and the yield of protein reached to 5.898%. For purifying the crude glycoprotein, the stage renounces of DEAE-52 column chromatography were done, respectively, with 0.05, 0.1, 0.5 mol/L NaHCO3 solution, and further purification was done with Sephadex G-100 column chromatography. Finally, two pieces of seahorse glycoprotein were obtained by the column chromatography, that is, HG-11 and HG-21. The saccharide content was 56.7975% and 39.479%, the protein content was 30.5475% and 51.747%, respectively. PMID:26288722

Improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein. Investigation and resolution of factors affecting its quantification

Energy Technology Data Exchange (ETDEWEB)

Dawney, A B.St.J.; Thornley, C; Cattell, W R [Saint Bartholomew' s Hospital, London (UK)

1982-09-15

A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4/sup 0/C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance.

Growth hormone secretion is diminished and tightly controlled in humans enriched for familial longevity

DEFF Research Database (Denmark)

van der Spoel, Evie; Jansen, Steffy W; Akintola, Abimbola A

2016-01-01

Reduced growth hormone (GH) signaling has been consistently associated with increased health and lifespan in various mouse models. Here, we assessed GH secretion and its control in relation with human familial longevity. We frequently sampled blood over 24 h in 19 middle-aged offspring of long......-living families from the Leiden Longevity Study together with 18 of their partners as controls. Circulating GH concentrations were measured every 10 min and insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP3) every 4 h. Using deconvolution analysis, we found that 24-h.......39-0.53)] compared with controls [0.66 (0.56-0.77)], indicating tighter control of GH secretion. No significant differences were observed in circulating levels of IGF-1 and IGFBP3 between offspring and controls. In conclusion, GH secretion in human familial longevity is characterized by diminished secretion rate...

A novel PET imaging protocol identifies seizure-induced regional overactivity of P-glycoprotein at the blood-brain barrier

Science.gov (United States)

Bankstahl, Jens P.; Bankstahl, Marion; Kuntner, Claudia; Stanek, Johann; Wanek, Thomas; Meier, Martin; Ding, Xiao-Qi; Müller, Markus; Langer, Oliver; Löscher, Wolfgang

2013-01-01

About one third of epilepsy patients are pharmacoresistant. Overexpression of P-glycoprotein and other multidrug transporters at the blood-brain barrier is thought to play an important role in drug-refractory epilepsy. Thus, quantification of regionally different P-glycoprotein activity in the brain in vivo is essential to identify P-glycoprotein overactivity as the relevant mechanism for drug-resistance in an individual patient. Using the radiolabeled P-glycoprotein substrate (R)-[11C]verapamil and different doses of co-administered tariquidar, which is an inhibitor of P-glycoprotein, we evaluated whether small-animal positron emission tomography (PET) can quantify regional changes in transporter function in the rat brain at baseline and 48 h after a pilocarpine-induced status epilepticus. P-glycoprotein expression was additionally quantified by immunohistochemistry. To reveal putative seizure-induced changes in blood-brain barrier integrity, we performed gadolinium-enhanced magnetic resonance scans on a 7.0 Tesla small-animal scanner. Before P-glycoprotein modulation, brain uptake of (R)-[11C]verapamil was low in all regions investigated in control and post-status epilepticus rats. After administration of 3 mg/kg tariquidar, which inhibits P-glycoprotein only partially, we observed increased regional differentiation in brain activity uptake in post-status epilepticus versus control rats, which diminished after maximal P-glycoprotein inhibition. Regional increases in the efflux rate constant k2, but not in distribution volume VT or influx rate constant K1, correlated significantly with increases in P-glycoprotein expression measured by immunohistochemistry. This imaging protocol proves to be suitable to detect seizure-induced regional changes in P-glycoprotein activity and is readily applicable to humans, with the aim to detect relevant mechanisms of pharmacoresistance in epilepsy in vivo. PMID:21677164

Immunoglobulin-E reactivity to wine glycoproteins in heavy drinkers

DEFF Research Database (Denmark)

Gonzalez-Quintela, Arturo; Gomez-Rial, Jose; Valcarcel, Catalina

2011-01-01

and biological significance of IgE antibodies to N-glycans from wine glycoproteins in heavy drinkers. A structured questionnaire, skin prick tests, serum IgE levels, IgE-immunoblotting to wine extracts, and basophil activation tests were used to characterize 20 heavy drinkers and 10 control subjects. Eleven...... heavy drinkers (55%) showed IgE binding to proteins in wine extracts. The proteins were identified by mass spectrometry as grape-derived vacuolar invertase and thaumatin-like protein. Immunoblot reactivity was closely associated with the presence of IgE to CCDs and was inhibited by preincubation...... with a glycoconjugate containing bromelain-type N-glycans. The same conjugate, CCD-bearing allergens, and wine extracts activated basophils in patients with high-titer CCD-specific IgE but not in healthy controls. There was no relationship between immunoblot reactivity and consumption of any specific type of wine...

Fbs1 protects the malfolded glycoproteins from the attack of peptide:N-glycanase

International Nuclear Information System (INIS)

Yamaguchi, Yoshiki; Hirao, Takeshi; Sakata, Eri; Kamiya, Yukiko; Kurimoto, Eiji; Yoshida, Yukiko; Suzuki, Tadashi; Tanaka, Keiji; Kato, Koichi

2007-01-01

Fbs1 is a cytosolic lectin putatively operating as a chaperone as well as a substrate-recognition subunit of the SCF Fbs1 ubiquitin ligase complex. To provide structural and functional basis of preferential binding of Fbs1 to unfolded glycoproteins, we herein characterize the interaction of Fbs1 with a heptapeptide carrying Man 3 GlcNAc 2 by nuclear magnetic resonance (NMR) spectroscopy and other biochemical methods. Inspection of the NMR data obtained by use of the isotopically labeled glycopeptide indicated that Fbs1 interacts with sugar-peptide junctions, which are shielded in native glycoprotein, in many cases, but become accessible to Fbs1 in unfolded glycoproteins. Furthermore, Fbs1 was shown to inhibit deglycosylation of denatured ribonuclease B by a cytosolic peptide:N-glycanase (PNGase). On the basis of these data, we suggest that Fbs1 captures malfolded glycoproteins, protecting them from the attack of PNGase, during the chaperoning or ubiquitinating operation in the cytosol

Purification and characterization of a soluble glycoprotein from garlic (Allium sativum) and its in vitro bioactivity.

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Wang, Yan; Zou, Tingting; Xiang, Minghui; Jin, Chenzhong; Zhang, Xuejiao; Chen, Yong; Jiang, Qiuqing; Hu, Yihong

2016-10-02

A soluble glycoprotein was purified to homogeneity from ripe garlic (Allium sativum) bulbs using ammonium sulfate precipitation, Sephadex G-100 gel filtration, and diethylaminoethyl-52 cellulose anion-exchange chromatography. A native mass of 55.7 kDa estimated on gel permeation chromatography and a molecular weight of 13.2 kDa observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis supported that the glycoprotein is a homotetramer. β-Elimination reaction result suggested that the glycoprotein is an N-linked type. Fourier-transform infrared spectroscopy proved that it contains sugar. Gas chromatography-mass spectrometer analysis showed that its sugar component was galactose. The glycoprotein has 1,1-diphenyl-2-picrylhydrazil free radical scavenging activity and the peroxidation inhibition ability to polyunsaturated fatty acid. These results indicated that the glycoprotein has potential for food additives, functional foods, and even biotechnological and medical applications.

Both Epistasis and Diversifying Selection Drive the Structural Evolution of the Ebola Virus Glycoprotein Mucin-Like Domain.

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Ibeh, Neke; Nshogozabahizi, Jean Claude; Aris-Brosou, Stéphane

2016-06-01

Throughout the last 3 decades, Ebola virus (EBOV) outbreaks have been confined to isolated areas within Central Africa; however, the 2014 variant reached unprecedented transmission and mortality rates. While the outbreak was still under way, it was reported that the variant leading up to this outbreak evolved faster than previous EBOV variants, but evidence for diversifying selection was undetermined. Here, we test this selection hypothesis and show that while previous EBOV outbreaks were preceded by bursts of diversification, evidence for site-specific diversifying selection during the emergence of the 2014 EBOV clade is weak. However, we show strong evidence supporting an interplay between selection and correlated evolution (epistasis), particularly in the mucin-like domain (MLD) of the EBOV glycoprotein. By reconstructing ancestral structures of the MLD, we further propose a structural mechanism explaining how the substitutions that accumulated between 1918 and 1969 distorted the MLD, while more recent epistatic substitutions restored part of the structure, with the most recent substitution being adaptive. We suggest that it is this complex interplay between weak selection, epistasis, and structural constraints that has shaped the evolution of the 2014 EBOV variant. The role that selection plays in the emergence of viral epidemics remains debated, particularly in the context of the 2014 EBOV outbreak. Most critically, should such evidence exist, it is generally unclear how this relates to function and increased virulence. Here, we show that the viral lineage leading up to the 2014 outbreak underwent a complex interplay between selection and correlated evolution (epistasis) in a protein region that is critical for immune evasion. We then reconstructed the three-dimensional structure of this domain and showed that the initial mutations in this lineage deformed the structure, while subsequent mutations restored part of the structure. Along this mutational path, the

LcrG secretion is not required for blocking of Yops secretion in Yersinia pestis

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Matson Jyl S

2008-02-01

Full Text Available Abstract Background LcrG, a negative regulator of the Yersinia type III secretion apparatus has been shown to be primarily a cytoplasmic protein, but is secreted at least in Y. pestis. LcrG secretion has not been functionally analyzed and the relevance of LcrG secretion on LcrG function is unknown. Results An LcrG-GAL4AD chimera, originally constructed for two-hybrid analyses to analyze LcrG protein interactions, appeared to be not secreted but the LcrG-GAL4AD chimera retained the ability to regulate Yops secretion. This result led to further investigation to determine the significance of LcrG secretion on LcrG function. Additional analyses including deletion and substitution mutations of amino acids 2–6 in the N-terminus of LcrG were constructed to analyze LcrG secretion and LcrG's ability to control secretion. Some changes to the N-terminus of LcrG were found to not affect LcrG's secretion or LcrG's secretion-controlling activity. However, substitution of poly-isoleucine in the N-terminus of LcrG did eliminate LcrG secretion but did not affect LcrG's secretion controlling activity. Conclusion These results indicate that secretion of LcrG, while observable and T3SS mediated, is not relevant for LcrG's ability to control secretion.

Tamper-proof secret image-sharing scheme for identifying cheated secret keys and shared images

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Chen, Chien-Chang; Liu, Chong-An

2013-01-01

A (t,n) secret image-sharing scheme shares a secret image to n participants, and the t users recover the image. During the recovery procedure of a conventional secret image-sharing scheme, cheaters may use counterfeit secret keys or modified shared images to cheat other users' secret keys and shared images. A cheated secret key or shared image leads to an incorrect secret image. Unfortunately, the cheater cannot be identified. We present an exponent and modulus-based scheme to provide a tamper-proof secret image-sharing scheme for identifying cheaters on secret keys or shared images. The proposed scheme allows users to securely select their secret key. This assignment can be performed over networks. Modulus results of each shared image is calculated to recognize cheaters of a shared image. Experimental results indicate that the proposed scheme is excellent at identifying cheated secret keys and shared images.

Annotating Human P-Glycoprotein Bioassay Data.

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Zdrazil, Barbara; Pinto, Marta; Vasanthanathan, Poongavanam; Williams, Antony J; Balderud, Linda Zander; Engkvist, Ola; Chichester, Christine; Hersey, Anne; Overington, John P; Ecker, Gerhard F

2012-08-01

Huge amounts of small compound bioactivity data have been entering the public domain as a consequence of open innovation initiatives. It is now the time to carefully analyse existing bioassay data and give it a systematic structure. Our study aims to annotate prominent in vitro assays used for the determination of bioactivities of human P-glycoprotein inhibitors and substrates as they are represented in the ChEMBL and TP-search open source databases. Furthermore, the ability of data, determined in different assays, to be combined with each other is explored. As a result of this study, it is suggested that for inhibitors of human P-glycoprotein it is possible to combine data coming from the same assay type, if the cell lines used are also identical and the fluorescent or radiolabeled substrate have overlapping binding sites. In addition, it demonstrates that there is a need for larger chemical diverse datasets that have been measured in a panel of different assays. This would certainly alleviate the search for other inter-correlations between bioactivity data yielded by different assay setups.

Wrapped up in Covers: Preschoolers' Secrets and Secret Hiding Places

Science.gov (United States)

Corson, Kimberly; Colwell, Malinda J.; Bell, Nancy J.; Trejos-Castillo, Elizabeth

2014-01-01

In this qualitative study, interviews about children's secret hiding places were conducted with 3-5-year-olds (n?=?17) in a university sponsored preschool programme using art narratives. Since prior studies indicate that children understand the concept of a secret as early as five and that they associate secrets with hiding places, the purpose of…

Chemoenzymatic site-specific labeling of influenza glycoproteins as a tool to observe virus budding in real time.

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Maximilian Wei-Lin Popp

Full Text Available The influenza virus uses the hemagglutinin (HA and neuraminidase (NA glycoproteins to interact with and infect host cells. While biochemical and microscopic methods allow examination of the early steps in flu infection, the genesis of progeny virions has been more difficult to follow, mainly because of difficulties inherent in fluorescent labeling of flu proteins in a manner compatible with live cell imaging. We here apply sortagging as a chemoenzymatic approach to label genetically modified but infectious flu and track the flu glycoproteins during the course of infection. This method cleanly distinguishes influenza glycoproteins from host glycoproteins and so can be used to assess the behavior of HA or NA biochemically and to observe the flu glycoproteins directly by live cell imaging.

Intestinal mucus and juice glycoproteins have a liquid crystalline structure

International Nuclear Information System (INIS)

Denisova, E.A.; Lazarev, P.I.; Vazina, A.A.; Zheleznaya, L.A.

1985-01-01

X-ray diffraction patterns have been obtained from the following components of canine gastrointestinal tract: (1) native small intestine mucus layer; (2) the precipitate of the flocks formed in the duodenal juice with decreasing pH; (3) concentrated solutions of glycoproteins isolated from the duodenal juice. The X-ray patterns consist of a large number of sharp reflections of spacings between about 100 and 4 A. Some reflections are common for all components studied. All the patterns are interpreted as arising from the glycoprotein molecules ordered into a liquid crystalline structure. (author)

Platelet Glycoprotein Ib-IX and Malignancy

Science.gov (United States)

2010-09-01

provide a unique microenvironment supporting the accumulation of more platelets and the elaboration of a fibrin - rich network produced by coagulation...process and can initiate the formation of a platelet - rich thrombus by tethering the platelet to a thrombogenic surface. Several ligands binding to GP Ib... Platelet Glycoprotein Ib-IX and Malignancy PRINCIPAL INVESTIGATOR: Jerry Ware, Ph.D

Tolerogenic β2-glycoprotein I DNA vaccine and FK506 as an adjuvant attenuates experimental obstetric antiphospholipid syndrome.

Science.gov (United States)

Chao, Ya-Hsuan; Chen, Der-Yuan; Lan, Joung-Liang; Tang, Kuo-Tung; Lin, Chi-Chien

2018-01-01

DNA vaccines have recently emerged as a therapeutic agent for treating autoimmune diseases, such as multiple sclerosis. Antiphospholipid antibody syndrome (APS) is an autoimmune disease characterized by β2-glycoprotein I (β2-GPI)-targeting antiphospholipid antibodies (APAs) and vascular thrombosis or obstetrical complications. To examine the therapeutic potential of a β2-GPI DNA vaccine, we administered a vaccine mixed with FK506 as an adjuvant to a mouse model of obstetric APS. First, the pCMV3-β2-GPI DNA vaccine, which encodes the full-length human β2-GPI gene, was constructed. Then, we administered the β2-GPI DNA vaccine in 0.1 ml of saline, mixed with or without 100 μg of FK506, intramuscularly to the mice on days 28, 35 and 42. Blood titers of the anti-β2-GPI antibody, platelet counts, activated partial thromboplastin times (aPTTs), and the percentage of fetal loss were measured. We also stimulated murine splenic T cells ex vivo with β2-GPI and determined the T helper cell proportion and cytokine secretion. The administration of the β2-GPI DNA vaccine mixed with FK506 reduced the blood IgG anti-β2-GPI antibody titers and suppressed APS manifestations in mice. The combination also suppressed interferon-γ and interleukin (IL)-17A secretion but increased the Treg cell proportion and IL-10 secretion in murine splenic T cells following ex vivo stimulation with β2-GPI. Our results demonstrated the therapeutic efficacy of a β2-GPI DNA vaccine and FK506 as an adjuvant in a murine model of obstetric APS. Possible mechanisms include the inhibition of Th1 and Th17 responses and the up-regulation of Treg cells.

C-terminus glycans with critical functional role in the maturation of secretory glycoproteins.

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Daniela Cioaca

Full Text Available The N-glycans of membrane glycoproteins are mainly exposed to the extracellular space. Human tyrosinase is a transmembrane glycoprotein with six or seven bulky N-glycans exposed towards the lumen of subcellular organelles. The central active site region of human tyrosinase is modeled here within less than 2.5 Å accuracy starting from Streptomyces castaneoglobisporus tyrosinase. The model accounts for the last five C-terminus glycosylation sites of which four are occupied and indicates that these cluster in two pairs--one in close vicinity to the active site and the other on the opposite side. We have analyzed and compared the roles of all tyrosinase N-glycans during tyrosinase processing with a special focus on the proximal to the active site N-glycans, s6:N337 and s7:N371, versus s3:N161 and s4:N230 which decorate the opposite side of the domain. To this end, we have constructed mutants of human tyrosinase in which its seven N-glycosylation sites were deleted. Ablation of the s6:N337 and s7:N371 sites arrests the post-translational productive folding process resulting in terminally misfolded mutants subjected to degradation through the mannosidase driven ERAD pathway. In contrast, single mutants of the other five N-glycans located either opposite to the active site or into the N-terminus Cys1 extension of tyrosinase are temperature-sensitive mutants and recover enzymatic activity at the permissive temperature of 31°C. Sites s3 and s4 display selective calreticulin binding properties. The C-terminus sites s7 and s6 are critical for the endoplasmic reticulum retention and intracellular disposal. Results herein suggest that individual N-glycan location is critical for the stability, regional folding control and secretion of human tyrosinase and explains some tyrosinase gene missense mutations associated with oculocutaneous albinism type I.

The quality control of glycoprotein folding in the endoplasmic reticulum, a trip from trypanosomes to mammals

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A.J. Parodi

1998-05-01

Full Text Available The present review deals with the stages of synthesis and processing of asparagine-linked oligosaccharides occurring in the lumen of the endoplasmic reticulum and their relationship to the acquisition by glycoproteins of their proper tertiary structures. Special emphasis is placed on reactions taking place in trypanosomatid protozoa since their study has allowed the detection of the transient glucosylation of glycoproteins catalyzed by UDP-Glc:glycoprotein glucosyltransferase and glucosidase II. The former enzyme has the unique property of covalently tagging improperly folded conformations by catalyzing the formation of protein-linked Glc1Man7GlcNAc2, Glc1Man8GlcNac2 and Glc1Man9GlcNAc2 from the unglucosylated proteins. Glucosyltransferase is a soluble protein of the endoplasmic reticulum that recognizes protein domains exposed in denatured but not in native conformations (probably hydrophobic amino acids and the innermost N-acetylglucosamine unit that is hidden from macromolecular probes in most native glycoproteins. In vivo, the glucose units are removed by glucosidase II. The influence of oligosaccharides in glycoprotein folding is reviewed as well as the participation of endoplasmic reticulum chaperones (calnexin and calreticulin that recognize monoglucosylated species in the same process. A model for the quality control of glycoprotein folding in the endoplasmic reticulum, i.e., the mechanism by which cells recognize the tertiary structure of glycoproteins and only allow transit to the Golgi apparatus of properly folded species, is discussed. The main elements of this control are calnexin and calreticulin as retaining components, the UDP-Glc:glycoprotein glucosyltransferase as a sensor of tertiary structures and glucosidase II as the releasing agent.

Boronic Acid-Based Approach for Separation and Immobilization of Glycoproteins and Its Application in Sensing

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Lin Liu

2013-10-01

Full Text Available Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The analysis of their glyco-structures and concentration levels are increasingly important in diagnosis and proteomics. Boronic acids can covalently react with cis-diols in the oligosaccharide chains of glycoproteins to form five- or six-membered cyclic esters. Based on this interaction, boronic acid-based ligands and materials have attracted much attention in both chemistry and biology as the recognition motif for enrichment and chemo/biosensing of glycoproteins in recent years. In this work, we reviewed the progress in the separation, immobilization and detection of glycoproteins with boronic acid-functionalized materials and addressed its application in sensing.

Secretome analysis of Aspergillus fumigatus reveals Asp-hemolysin as a major secreted protein.

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Wartenberg, Dirk; Lapp, Katrin; Jacobsen, Ilse D; Dahse, Hans-Martin; Kniemeyer, Olaf; Heinekamp, Thorsten; Brakhage, Axel A

2011-11-01

Surface-associated and secreted proteins represent primarily exposed components of Aspergillus fumigatus during host infection. Several secreted proteins are known to be involved in defense mechanisms or immune evasion, thus, probably contributing to pathogenicity. Furthermore, several secreted antigens were identified as possible biomarkers for the verification of diseases caused by Aspergillus species. Nevertheless, there is only limited knowledge about the composition of the secretome and about molecular functions of particular proteins. To identify secreted proteins potentially essential for virulence, the core secretome of A. fumigatus grown in minimal medium was determined. Two-dimensional gel electrophoretic separation and subsequent MALDI-TOF-MS/MS analyses resulted in the identification of 64 different proteins. Additionally, secretome analyses of A. fumigatus utilizing elastin, collagen or keratin as main carbon and nitrogen source were performed. Thereby, the alkaline serine protease Alp1 was identified as the most abundant protein and hence presumably represents an important protease during host infection. Interestingly, the Asp-hemolysin (Asp-HS), which belongs to the protein family of aegerolysins and which was often suggested to be involved in fungal virulence, was present in the secretome under all growth conditions tested. In addition, a second, non-secreted protein with an aegerolysin domain annotated as Asp-hemolysin-like (HS-like) protein can be found to be encoded in the genome of A. fumigatus. Generation and analysis of Asp-HS and HS-like deletion strains revealed no differences in phenotype compared to the corresponding wild-type strain. Furthermore, hemolysis and cytotoxicity was not altered in both single-deletion and double-deletion mutants lacking both aegerolysin genes. All mutant strains showed no attenuation in virulence in a mouse infection model for invasive pulmonary aspergillosis. Overall, this study provides a comprehensive

Paired Immunoglobulin-like Receptor B Knockout Does Not Enhance Axonal Regeneration or Locomotor Recovery after Spinal Cord Injury*

OpenAIRE

Nakamura, Yuka; Fujita, Yuki; Ueno, Masaki; Takai, Toshiyuki; Yamashita, Toshihide

2010-01-01

Myelin components that inhibit axonal regeneration are believed to contribute significantly to the lack of axonal regeneration noted in the adult central nervous system. Three proteins found in myelin, Nogo, myelin-associated glycoprotein, and oligodendrocyte-myelin glycoprotein, inhibit neurite outgrowth in vitro. All of these proteins interact with the same receptors, namely, the Nogo receptor (NgR) and paired immunoglobulin-like receptor B (PIR-B). As per previous reports, corticospinal tr...

Integrated expression analysis of muscle hypertrophy identifies Asb2 as a negative regulator of muscle mass

Science.gov (United States)

Davey, Jonathan R.; Watt, Kevin I.; Parker, Benjamin L.; Chaudhuri, Rima; Ryall, James G.; Cunningham, Louise; Qian, Hongwei; Sartorelli, Vittorio; Chamberlain, Jeffrey; James, David E.

2016-01-01

The transforming growth factor-β (TGF-β) signaling network is a critical regulator of skeletal muscle mass and function and, thus, is an attractive therapeutic target for combating muscle disease, but the underlying mechanisms of action remain undetermined. We report that follistatin-based interventions (which modulate TGF-β network activity) can promote muscle hypertrophy that ameliorates aging-associated muscle wasting. However, the muscles of old sarcopenic mice demonstrate reduced response to follistatin compared with healthy young-adult musculature. Quantitative proteomic and transcriptomic analyses of young-adult muscles identified a transcription/translation signature elicited by follistatin exposure, which included repression of ankyrin repeat and SOCS box protein 2 (Asb2). Increasing expression of ASB2 reduced muscle mass, thereby demonstrating that Asb2 is a TGF-β network–responsive negative regulator of muscle mass. In contrast to young-adult muscles, sarcopenic muscles do not exhibit reduced ASB2 abundance with follistatin exposure. Moreover, preventing repression of ASB2 in young-adult muscles diminished follistatin-induced muscle hypertrophy. These findings provide insight into the program of transcription and translation events governing follistatin-mediated adaptation of skeletal muscle attributes and identify Asb2 as a regulator of muscle mass implicated in the potential mechanistic dysfunction between follistatin-mediated muscle growth in young and old muscles. PMID:27182554

Influence of immunomodulators on the lymphokine secretion of irradiated lymphocytes

International Nuclear Information System (INIS)

Kowalczyk-Bronisz, S.H.

1986-01-01

Spleen lymphocytes derived from guinea pigs loose their ability to secrete lymphokines induced by Con A after treatment with irradiation (500 and 750 mC/kg). In the presence of the immunomodulators isoprinosine, levamisole and the thymosine-like factor TFX the lymphocytes are again capable of secreting lymphokines. After treatment with immunomodulators in dosages between 10 and 100 μg/ml the migration inhibition activity for macrophages and the chemotactic activity for polymorphonuclear granulocytes produced by lymphocytes were restored. (author)

Pituitary tumour causing gigantism. Morphology and in vitro hormone secretion.

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Anniko, M; Ritzén, E M

1986-01-01

True gigantism with overproduction of growth hormone (GH) and prolactin (PRL) was diagnosed in a 13-year-old boy. The clinical history indicated that the tumour had caused an oversecretion of GH since the age of 4-5 years. At diagnosis, the sella turcica was markedly enlarged. No infiltrative growth was noted at surgery. Endocrine investigations showed elevated GH and PRL secretion. Light and electron microscopy of tumour tissue revealed densely packed pleomorphic cells of both GH and PRL type. In addition, oncocyte-like cells were observed. Organ culture of pieces of tumour tissue demonstrated continued secretion of GH and PRL into the medium for more than 5 days in vitro. Addition of bromocriptine to the medium caused a rapid decline in PRL secretion while GH secretion remained the same. X-ray irradiation in vitro also caused a decrease in PRL secretion. These effects of bromocriptine and X-ray on hormone secretion in vitro mirrored the corresponding effect of treatment, when the patient showed signs of tumour recurrence after pituitary surgery. It is concluded that also in childhood, the in vitro response of tumour tissue to various treatments may be explored as a possible way to predict the efficacy of pharmacological or irradiation treatment of pituitary tumours.

Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.

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José-Daniel Aroca-Aguilar

Full Text Available Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc. affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues.

Glycan structures contain information for the spatial arrangement of glycoproteins in the plasma membrane.

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M Kristen Hall

Full Text Available Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro(-5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells.

Design and synthesis of an antigenic mimic of the Ebola glycoprotein

OpenAIRE

Rutledge, Ryan D.; Huffman, Brian J.; Cliffel, David E.; Wright, David W.

2008-01-01

An antigenic mimic of the Ebola glycoprotein was synthesized and tested for its ability to be recognized by an anti-Ebola glycoprotein antibody. Epitope-mapping procedures yielded a suitable epitope that, when presented on the surface of a nanoparticle, forms a structure that is recognized by an antibody specific for the native protein. This mimic-antibody interaction has been quantitated through ELISA and QCM-based methods and yielded an affinity (Kd = 12 × 10−6 M) within two orders of magni...

On the presence of prostatic secretion protein in rat seminal fluid

International Nuclear Information System (INIS)

Borgstroem, E.; Pousette, A.; Bjoerk, P.; Hoegberg, B.; Carlstroem, K.; Sundelin, B.; Gustafsson, J.A.

1981-01-01

The copulating plug collected from the tip of the penis from rats immediately after decapitation contains a protein very similar and probably identical to PSP (prostatic secretion protein); this protein has earlier been purified from rat prostatic cytosol and characterized. The protein present in the copulating plug interacts with [3H]estramustine and binds to the antibody raised against rat PSP. The concentration of the protein in the copulating plug is 400 ng/mg of total protein, when measured using the radioimmunoassay technique developed earlier for measurement of PSP in rat prostate. The [3H]estramustine-protein complex formed in a preparation of the copulating plug has an apparent molecular weight of about 50,000 and a sedimentation coefficient of about 3S when analyzed using sucrose density gradient centrifugation. The complex was retained on Concanavalin-A Sepharose indicating that the protein is a glycoprotein. Binding of the complex was also observed on hydroxylapatite and DEAE-Sephadex columns, from which it was eluted at 0.18 M KCl. Light microscope autoradiograms of rat sperms incubated with 125I-labeled PSP indicated that PSP is bound to all parts of the sperms. A macromolecule interacting with the PSP-antibodies is also present in human seminal fluid but at a concentration considerably lower than in rat seminal fluid. The present study shows that a macromolecule probably identical to prostatic secretion protein is present in the copulating plug from the rat. The biological role of this protein in normal male fertility is discussed

Involvement of Leishmania donovani major surface glycoprotein ...

Indian Academy of Sciences (India)

The major surface glycoprotein gp63 of the kinetoplastid protozoal parasite Leishmania is implicated as a ligand mediating uptake of the parasite into, and survival within, the host macrophage. By expressing gp63 antisense RNA from an episomal vector in L. donovani promastigotes, gp63-deficient transfectants were ...

A novel two-component system involved in secretion stress response in Streptomyces lividans.

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Sonia Gullón

Full Text Available BACKGROUND: Misfolded proteins accumulating outside the bacterial cytoplasmic membrane can interfere with the secretory machinery, hence the existence of quality factors to eliminate these misfolded proteins is of capital importance in bacteria that are efficient producers of secretory proteins. These bacteria normally use a specific two-component system to respond to the stress produced by the accumulation of the misfolded proteins, by activating the expression of HtrA-like proteases to specifically eliminate the incorrectly folded proteins. METHODOLOGY/PRINCIPAL FINDINGS: Overproduction of alpha-amylase in S. lividans causing secretion stress permitted the identification of a two-component system (SCO4156-SCO4155 that regulates three HtrA-like proteases which appear to be involved in secretion stress response. Mutants in each of the genes forming part of the two-genes operon that encodes the sensor and regulator protein components accumulated misfolded proteins outside the cell, strongly suggesting the involvement of this two-component system in the S. lividans secretion stress response. CONCLUSIONS/SIGNIFICANCE: To our knowledge this is the first time that a specific secretion stress response two-component system is found to control the expression of three HtrA-like protease genes in S. lividans, a bacterium that has been repeatedly used as a host for the synthesis of homologous and heterologous secretory proteins of industrial application.

Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

African Journals Online (AJOL)

User

2011-05-02

May 2, 2011 ... 1National Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan. 2Department of ..... E glycoprotein and its interaction with antibody with the method of molecular dynamics and molecular model ...

eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

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Xing Hua Tang

Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

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Kamel El Omari

2013-01-01

Full Text Available Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1 at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed.

Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

Science.gov (United States)

El Omari, Kamel; Iourin, Oleg; Harlos, Karl; Grimes, Jonathan M.; Stuart, David I.

2013-01-01

Summary Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1) at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed. PMID:23273918

Type 1 Does The Two-Step: Type 1 Secretion Substrates With A Functional Periplasmic Intermediate.

Science.gov (United States)

Smith, Timothy J; Sondermann, Holger; O'Toole, George A

2018-06-04

Bacteria have evolved several secretion strategies for polling and responding to environmental flux and insult. Of these, the type 1 secretion system (T1SS) is known to secrete an array of biologically diverse proteins - from small < 10 kDa bacteriocins to gigantic adhesins with a mass over 1 MDa. For the last several decades T1SS have been characterized as a one-step translocation strategy whereby the secreted substrate is transported directly into the extracellular environment from the cytoplasm with no periplasmic intermediate. Recent phylogenetic, biochemical, and genetic evidence point to a distinct sub-group of T1SS machinery linked with a bacterial transglutaminase-like cysteine proteinase (BTLCP), which uses a two-step secretion mechanism. BTLCP-linked T1SS transport a class of repeats-in-toxin (RTX) adhesins that are critical for biofilm formation. The prototype of this RTX adhesin group, LapA of Pseudomonas fluorescens Pf0-1, uses a novel N-terminal retention module to anchor the adhesin at the cell surface as a secretion intermediate threaded through the outer membrane-localized, TolC-like protein LapE. This secretion intermediate is post-translationally cleaved by the BTLCP family LapG protein to release LapA from its cognate T1SS pore. Thus, secretion of LapA and related RTX adhesins into the extracellular environment appears to be a T1SS-mediated, two-step process that involves a periplasmic intermediate. In this review, we contrast the T1SS machinery and substrates of the BLTCP-linked two-step secretion process with those of the classical one-step T1SS to better understand the newly recognized and expanded role of this secretion machinery. Copyright © 2018 American Society for Microbiology.

Combined virus-like particle and fusion protein-encoding DNA vaccination of cotton rats induces protection against respiratory syncytial virus without causing vaccine-enhanced disease

Energy Technology Data Exchange (ETDEWEB)

Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Park, Soojin; Kwon, Young-Man; Lee, Youri; Ko, Eun-Ju; Jung, Yu-Jin [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Lee, Jong Seok [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); National Institute of Biological Resources, Incheon (Korea, Republic of); Kim, Yu-Jin [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Lee, Yu-Na; Kim, Min-Chul [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo (Korea, Republic of); Cho, Minkyoung [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Kang, Sang-Moo, E-mail: skang24@gsu.edu [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States)

2016-07-15

A safe and effective vaccine against respiratory syncytial virus (RSV) should confer protection without causing vaccine-enhanced disease. Here, using a cotton rat model, we investigated the protective efficacy and safety of an RSV combination vaccine composed of F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins (FFG-VLP). Cotton rats with FFG-VLP vaccination controlled lung viral replication below the detection limit, and effectively induced neutralizing activity and antibody-secreting cell responses. In comparison with formalin inactivated RSV (FI-RSV) causing severe RSV disease after challenge, FFG-VLP vaccination did not cause weight loss, airway hyper-responsiveness, IL-4 cytokines, histopathology, and infiltrates of proinflammatory cells such as eosinophils. FFG-VLP was even more effective in preventing RSV-induced pulmonary inflammation than live RSV infections. This study provides evidence that FFG-VLP can be developed into a safe and effective RSV vaccine candidate. - Highlights: • Combined RSV FFG VLP vaccine is effective in inducing F specific responses. • FFG VLP vaccine confers RSV neutralizing activity and viral control in cotton rats. • Cotton rats with RSV FFG VLP vaccination do not show vaccine-enhanced disease. • Cotton rats with FFG VLP vaccine induce F specific antibody secreting cell responses. • Cotton rats with FFG VLP do not induce lung cellular infiltrates and Th2 cytokine.

Combined virus-like particle and fusion protein-encoding DNA vaccination of cotton rats induces protection against respiratory syncytial virus without causing vaccine-enhanced disease

International Nuclear Information System (INIS)

Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Park, Soojin; Kwon, Young-Man; Lee, Youri; Ko, Eun-Ju; Jung, Yu-Jin; Lee, Jong Seok; Kim, Yu-Jin; Lee, Yu-Na; Kim, Min-Chul; Cho, Minkyoung; Kang, Sang-Moo

2016-01-01

A safe and effective vaccine against respiratory syncytial virus (RSV) should confer protection without causing vaccine-enhanced disease. Here, using a cotton rat model, we investigated the protective efficacy and safety of an RSV combination vaccine composed of F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins (FFG-VLP). Cotton rats with FFG-VLP vaccination controlled lung viral replication below the detection limit, and effectively induced neutralizing activity and antibody-secreting cell responses. In comparison with formalin inactivated RSV (FI-RSV) causing severe RSV disease after challenge, FFG-VLP vaccination did not cause weight loss, airway hyper-responsiveness, IL-4 cytokines, histopathology, and infiltrates of proinflammatory cells such as eosinophils. FFG-VLP was even more effective in preventing RSV-induced pulmonary inflammation than live RSV infections. This study provides evidence that FFG-VLP can be developed into a safe and effective RSV vaccine candidate. - Highlights: • Combined RSV FFG VLP vaccine is effective in inducing F specific responses. • FFG VLP vaccine confers RSV neutralizing activity and viral control in cotton rats. • Cotton rats with RSV FFG VLP vaccination do not show vaccine-enhanced disease. • Cotton rats with FFG VLP vaccine induce F specific antibody secreting cell responses. • Cotton rats with FFG VLP do not induce lung cellular infiltrates and Th2 cytokine.

Fructose stimulates GLP-1 but not GIP secretion in mice, rats, and humans

DEFF Research Database (Denmark)

Kuhre, Rune Ehrenreich; Gribble, Fiona M; Hartmann, Bolette

2014-01-01

Nutrients often stimulate gut hormone secretion, but the effects of fructose are incompletely understood. We studied the effects of fructose on a number of gut hormones with particular focus on glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). In healthy humans......, fructose intake caused a rise in blood glucose and plasma insulin and GLP-1, albeit to a lower degree than isocaloric glucose. Cholecystokinin secretion was stimulated similarly by both carbohydrates, but neither peptide YY3-36 nor glucagon secretion was affected by either treatment. Remarkably, while...... glucose potently stimulated GIP release, fructose was without effect. Similar patterns were found in the mouse and rat, with both fructose and glucose stimulating GLP-1 secretion, whereas only glucose caused GIP secretion. In GLUTag cells, a murine cell line used as model for L cells, fructose...

A Diverse Panel of Hepatitis C Virus Glycoproteins for Use in Vaccine Research Reveals Extremes of Monoclonal Antibody Neutralization Resistance.

Science.gov (United States)

Urbanowicz, Richard A; McClure, C Patrick; Brown, Richard J P; Tsoleridis, Theocharis; Persson, Mats A A; Krey, Thomas; Irving, William L; Ball, Jonathan K; Tarr, Alexander W

2015-12-23

Despite significant advances in the treatment of hepatitis C virus (HCV) infection, the need to develop preventative vaccines remains. Identification of the best vaccine candidates and evaluation of their performance in preclinical and clinical development will require appropriate neutralization assays utilizing diverse HCV isolates. We aimed to generate and characterize a panel of HCV E1E2 glycoproteins suitable for subsequent use in vaccine and therapeutic antibody testing. Full-length E1E2 clones were PCR amplified from patient-derived serum samples, cloned into an expression vector, and used to generate viral pseudoparticles (HCVpp). In addition, some of these clones were used to generate cell culture infectious (HCVcc) clones. The infectivity and neutralization sensitivity of these viruses were then determined. Bioinformatic and HCVpp infectivity screening of approximately 900 E1E2 clones resulted in the assembly of a panel of 78 functional E1E2 proteins representing distinct HCV genotypes and different stages of infection. These HCV glycoproteins differed markedly in their sensitivity to neutralizing antibodies. We used this panel to predict antibody efficacy against circulating HCV strains, highlighting the likely reason why some monoclonal antibodies failed in previous clinical trials. This study provides the first objective categorization of cross-genotype patient-derived HCV E1E2 clones according to their sensitivity to antibody neutralization. It has shown that HCV isolates have clearly distinguishable neutralization-sensitive, -resistant, or -intermediate phenotypes, which are independent of genotype. The panel provides a systematic means for characterization of the neutralizing response elicited by candidate vaccines and for defining the therapeutic potential of monoclonal antibodies. Hepatitis C virus (HCV) has a global burden of more than 170 million people, many of whom cannot attain the new, expensive, direct-acting antiviral therapies. A safe and

Melatonin and Angelman Syndrome: Implications and Mathematical Model of Diurnal Secretion

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Justyna Paprocka

2017-01-01

Full Text Available The main aim of the study was to compare the melatonin rhythms in subjects with Angelman syndrome (n=9 and in children with (n=80 and without (n=40 epilepsy (nonepileptic patients diagnosed with peripheral nerve palsies, myopathy, and back pain using our mathematical model of melatonin circadian secretion. The characteristics describing the diurnal hormone secretion such as minimum melatonin concentration, release amplitude, phase shift of melatonin release, and sleep duration as well as the dim light melatonin onset (DLMO of melatonin secretion and the γ shape parameter allow analyzing the fit and deducing about how much the measured melatonin profile differs from a physiological bell-shaped secretion. The estimated sleep duration and phase shift of melatonin release as well as the DMLO offsets at 25% and 50% relative thresholds are the key characteristic of Angelman syndrome children. As revealed from the γ shape parameter, the melatonin secretion profiles are disturbed in majority of the AG subjects revealing rather a triangular course instead of the bell-like one.

Proghrelin peptides: Desacyl ghrelin is a powerful inhibitor of acylated ghrelin, likely to impair physiological effects of acyl ghrelin but not of obestatin A study of pancreatic polypeptide secretion from mouse islets

DEFF Research Database (Denmark)

Kumar, Rajesh; Salehi, Albert; Rehfeld, Jens F

2010-01-01

Proghrelin, produced by the ghrelin (A-like) cells of the gastric mucosa, gives rise to cleavage products, including desacyl ghrelin, acyl ghrelin and obestatin. The products are thought to be secreted concomitantly. In an earlier study we found acyl ghrelin and obestatin, but not desacyl ghrelin...

Effects of prostaglandin E/sub 1/ on the metabolism in rat parathyroid gland in vitro

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Licata, A A [Rochester Univ., NY (USA). School of Medicine and Dentistry; Au, W Y [Arkansas Univ., Little Rock (USA); Vera, J; Bartter, F C [National Institutes of Health, Bethesda, MD (USA)

1979-01-04

Some effects of prostaglandin E/sub 1/ on the metabolism of rat parathyroid glands have been investigated using a culture system containing basal Eagle's medium supplemented with 5-10% heat-inactivated rat serum. Rat parathyroid glands incorporate (/sup 3/H)fucose and /sup 14/C-labeled amino acids into cellular glycoproteins and secrete some of these into the culture medium. Gel filtration chromatography separates these glycoproteins into three classes, the smallest of which (peak 3) is secreted with immunoreactive parathyroid hormone. In cultures of 48 h, prostaglandin E/sub 1/ (1 ..mu..g/ml) specifically inhibits the secretion of peak 3 and of parathyroid hormone but has no effect on the incorporation of (/sup 3/H)-fucose, /sup 14/C-labeled amino acids, or (/sup 3/H)uridine into parathyroid glands. Cytochalasin B inhibits the secretion of parathyroid hormone and the incorporation of isotopic fucose and amino acids. Cortisol stimulates incorporation of (/sup 3/H)fucose and the secretion of parathyroid hormone even in the presence of inhibitory doses of prostaglandin E/sub 1/. It is concluded that, in organ culture, prostaglandin E/sub 1/ inhibits the secretion of parathyroid hormone and of a specific glycoprotein the function of which may be related to the secretion of the hormone.

Effect of oral contraceptives and/or metformin on GLP-1 secretion and reactive hypoglycemia in PCOS

DEFF Research Database (Denmark)

Glintborg, Dorte; Mumm, Hanne; Holst, Jens Juul

2017-01-01

CONTEXT: Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS ...... significantly lower in obese vs. lean patients and were inversely associated with BMI. CONCLUSIONS: AUC GLP-1 levels were unchanged during treatment. Increased risk of hypoglycemia during metformin +OCP could be associated with increased insulin secretion.......CONTEXT: Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS......, glucose, insulin, and C-peptide during 5 h OGTT. RESULTS: Fasting GLP-1 levels increased during metformin+OCP vs. OCP treatment, whereas AUC GLP-1 levels were unchanged during medical treatment. The prevalence of reactive hypoglycemia increased from 9/65 to 14/65 after intervention (P

Glucagon-like-peptide-1 secretion from canine L-cells is increased by glucose-dependent-insulinotropic peptide but unaffected by glucose

DEFF Research Database (Denmark)

Damholt, A B; Buchan, A M; Kofod, Hans

1998-01-01

dependently stimulated the release of GLP-1 and resulted in a 2-fold increase at 100 nM GIP. This effect was fully inhibited by 10 nM somatostatin. However, neither basal or GIP stimulated GLP-1 secretion were affected by ambient glucose concentrations from 5-25 mM. The receptor-independent secretagogues beta...... but not by staurosporine. These results indicate that glucose does not directly stimulate canine L-cells. It is more probable that glucose releases GIP from the upper intestine that in turn stimulates GLP-1 secretion. The ability of GIP to stimulate GLP-1 secretion is probably mediated through activation of protein kinase...

Proteomic identification of secreted proteins of Propionibacterium acnes

Directory of Open Access Journals (Sweden)

Holland Carsten

2010-08-01

Full Text Available Abstract Background The anaerobic Gram-positive bacterium Propionibacterium acnes is a human skin commensal that resides preferentially within sebaceous follicles; however, it also exhibits many traits of an opportunistic pathogen, playing roles in a variety of inflammatory diseases such as acne vulgaris. To date, the underlying disease-causing mechanisms remain ill-defined and knowledge of P. acnes virulence factors remains scarce. Here, we identified proteins secreted during anaerobic cultivation of a range of skin and clinical P. acnes isolates, spanning the four known phylogenetic groups. Results Culture supernatant proteins of P. acnes were separated by two-dimensional electrophoresis (2-DE and all Coomassie-stained spots were subsequently identified by MALDI mass spectrometry (MALDI-MS. A set of 20 proteins was secreted in the mid-exponential growth phase by the majority of strains tested. Functional annotation revealed that many of these common proteins possess degrading activities, including glycoside hydrolases with similarities to endoglycoceramidase, β-N-acetylglucosaminidase and muramidase; esterases such as lysophospholipase and triacylglycerol lipase; and several proteases. Other secreted factors included Christie-Atkins-Munch-Petersen (CAMP factors, glyceraldehyde 3-phosphate dehydrogenase (GAPDH, and several hypothetical proteins, a few of which are unique to P. acnes. Strain-specific differences were apparent, mostly in the secretion of putative adhesins, whose genes exhibit variable phase variation-like sequence signatures. Conclusions Our proteomic investigations have revealed that the P. acnes secretome harbors several proteins likely to play a role in host-tissue degradation and inflammation. Despite a large overlap between the secretomes of all four P. acnes phylotypes, distinct differences between predicted host-tissue interacting proteins were identified, providing potential insight into the differential virulence

Cholecystokinin inhibits gastrin secretion independently of paracrine somatostatin secretion in the pig

DEFF Research Database (Denmark)

Schmidt, P T; Hansen, L; Hilsted, L

2004-01-01

BACKGROUND: Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. The aim of the study was to test directly whether cholecystokinin inhibition of antral gastrin secretion is mediated by somatostatin....... METHODS: The effects of CCK on gastrin and somatostatin secretion were studied in isolated vascularly perfused preparations of pig antrum before and after immunoneutralization brought about by infusion of large amounts of a high affinity monoclonal antibody against somatostatin. RESULTS: CCK infusion...... at 10(-9) M and 10(-8) M decreased gastrin output to 70.5% +/- 7.6% (n = 8) and 76.3% +/- 3.6% (n = 7) of basal output, respectively. CCK at 10(-10) M had no effect (n = 6). Somatostatin secretion was dose-dependently increased by CCK infusion and increased to 268 +/- 38.2% (n = 7) of basal secretion...

Decidual-secreted factors alter invasive trophoblast membrane and secreted proteins implying a role for decidual cell regulation of placentation.

Directory of Open Access Journals (Sweden)

Ellen Melaleuca Menkhorst

Full Text Available Inadequate or inappropriate implantation and placentation during the establishment of human pregnancy is thought to lead to first trimester miscarriage, placental insufficiency and other obstetric complications. To create the placental blood supply, specialized cells, the 'extravillous trophoblast' (EVT invade through the differentiated uterine endometrium (the decidua to engraft and remodel uterine spiral arteries. We hypothesized that decidual factors would regulate EVT function by altering the production of EVT membrane and secreted factors. We used a proteomics approach to identify EVT membrane and secreted proteins regulated by decidual cell factors. Human endometrial stromal cells were decidualized in vitro by treatment with estradiol (10(-8 M, medroxyprogesterone acetate (10(-7 M and cAMP (0.5 mM for 14 days. Conditioned media (CM was collected on day 2 (non-decidualized CM and 14 (decidualized CM of treatment. Isolated primary EVT cultured on Matrigel™ were treated with media control, non-decidualized or decidualized CM for 16 h. EVT CM was fractionated for proteins <30 kDa using size-exclusion affinity nanoparticles (SEAN before trypsin digestion and HPLC-MS/MS. 43 proteins produced by EVT were identified; 14 not previously known to be expressed in the placenta and 12 which had previously been associated with diseases of pregnancy including preeclampsia. Profilin 1, lysosome associated membrane glycoprotein 1 (LAMP1, dipeptidyl peptidase 1 (DPP1/cathepsin C and annexin A2 expression by interstitial EVT in vivo was validated by immunhistochemistry. Decidual CM regulation in vitro was validated by western blotting: decidualized CM upregulated profilin 1 in EVT CM and non-decidualized CM upregulated annexin A2 in EVT CM and pro-DPP1 in EVT cell lysate. Here, non-decidualized factors induced protease expression by EVT suggesting that non-decidualized factors may induce a pro-inflammatory cascade. Preeclampsia is a pro

Dynamic quantum secret sharing

International Nuclear Information System (INIS)

Jia, Heng-Yue; Wen, Qiao-Yan; Gao, Fei; Qin, Su-Juan; Guo, Fen-Zhuo

2012-01-01

In this Letter we consider quantum secret sharing (QSS) between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications. -- Highlights: ► We consider quantum secret sharing between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). ► In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. ► Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. ► Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. ► Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications.

Presenting native-like HIV-1 envelope trimers on ferritin nanoparticles improves their immunogenicity

NARCIS (Netherlands)

Sliepen, Kwinten; Ozorowski, Gabriel; Burger, Judith A.; van Montfort, Thijs; Stunnenberg, Melissa; Labranche, Celia; Montefiori, David C.; Moore, John P.; Ward, Andrew B.; Sanders, Rogier W.

2015-01-01

Background: Presenting vaccine antigens in particulate form can improve their immunogenicity by enhancing B cell activation. Findings: We describe ferritin-based protein nanoparticles that display multiple copies of native-like HIV-1 envelope glycoprotein trimers (BG505 SOSIP.664). Trimer-bearing

Rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein VI, and the ligand-binding domain of glycoprotein Ibalpha

DEFF Research Database (Denmark)

Bergmeier, W; Bouvard, D; Eble, J A

2001-01-01

Although alpha(2)beta(1) integrin (glycoprotein Ia/IIa) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. Recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from the v...

Comparison of glycoprotein expression between ovarian and colon adenocarcinomas

DEFF Research Database (Denmark)

Multhaupt, H A; Arenas-Elliott, C P; Warhol, M J

1999-01-01

, carcinoembryonic antigen, and cytokeratins 7 and 20 to detect tumor-associated glycoproteins and keratin proteins in ovarian and colonic carcinomas. RESULTS: CA125, carcinoembryonic antigen, and cytokeratins 7 and 20 can distinguish between colonic and serous or endometrioid adenocarcinomas of the ovary in both...... primary and metastatic lesions. Mucinous ovarian adenocarcinomas differed in that they express carcinoembryonic antigen and cytokeratins 7 and 20 and weakly express CA125. The other glycoprotein antigens were equally expressed by ovarian and colonic adenocarcinomas and therefore were of no use...... in distinguishing between these 2 entities. CONCLUSION: A panel of monoclonal antibodies against cytokeratins 7 and 20 antigens, CA125, and carcinoembryonic antigen is useful in differentiating serous and endometrioid adenocarcinomas of the ovary from colonic adenocarcinomas. Mucinous ovarian adenocarcinomas cannot...

Secret Key Agreement: Fundamental Limits and Practical Challenges

KAUST Repository

Rezki, Zouheir

2017-02-15

Despite the tremendous progress made toward establishing PLS as a new paradigm to guarantee security of communication systems at the physical layerthere is a common belief among researchers and industrials that there are many practical challenges that prevent PLS from flourishing at the industrial scale. Most secure message transmission constructions available to date are tied to strong assumptions on CSI, consider simple channel models and undermine eavesdropping capabilities; thus compromising their practical interest to a big extent. Perhaps arguably, the most likely reasonable way to leverage PLS potential in securing modern wireless communication systems is via secret-key agreement. In the latter setting, the legitimate parties try to agree on a key exploiting availability of a public channel with high capacity which is also accessible to the eavesdropper. Once a key is shared by the legitimate parties, they may use it in a one-time pad encryption, for instance. In this article, we investigate two performance limits of secret-key agreement communications; namely, the secret-key diversity-multiplexing trade-off and the effect of transmit correlation on the secretkey capacity. We show via examples how secretkey agreement offers more flexibility than secure message transmissions. Finally, we explore a few challenges of secret-key agreement concept and propose a few guidelines to overturn them.

IgA antibodies against β2 glycoprotein I in hemodialysis patients are an independent risk factor for mortality.

Science.gov (United States)

Serrano, Antonio; García, Florencio; Serrano, Manuel; Ramírez, Elisa; Alfaro, F Javier; Lora, David; de la Cámara, Agustín Gómez; Paz-Artal, Estela; Praga, Manuel; Morales, Jose M

2012-06-01

Cardiovascular complications are the most important cause of death in patients on dialysis with end-stage renal disease. Antibodies reacting with β-glycoprotein I seem to play a pathogenic role in antiphospholipid syndrome and stroke and are involved in the origin of atherosclerosis. Here we evaluated the presence of anticardiolipin and anti-β-glycoprotein I antibodies together with other vascular risk factors and their relationship with mortality and cardiovascular morbidity in a cohort of 124 hemodialysis patients prospectively followed for 2 years. Of these, 41 patients were significantly positive for IgA anti-β-glycoprotein I, and the remaining had normal values. At 24 months, overall and cardiovascular mortality and thrombotic events were all significantly higher in patients with high anti-β-glycoprotein I antibodies. Multivariate analysis using Cox regression modeling found that age, hypoalbuminemia, use of dialysis catheters, and IgA β-glycoprotein I antibodies were independent risk factors for death. Thus, IgA antibodies to β-glycoprotein I are detrimental to the clinical outcome of hemodialysis patients.

Beta-amyloid peptides undergo regulated co-secretion with neuropeptide and catecholamine neurotransmitters.

Science.gov (United States)

Toneff, Thomas; Funkelstein, Lydiane; Mosier, Charles; Abagyan, Armen; Ziegler, Michael; Hook, Vivian

2013-08-01

Beta-amyloid (Aβ) peptides are secreted from neurons, resulting in extracellular accumulation of Aβ and neurodegeneration of Alzheimer's disease. Because neuronal secretion is fundamental for the release of neurotransmitters, this study assessed the hypothesis that Aβ undergoes co-release with neurotransmitters. Model neuronal-like chromaffin cells were investigated, and results illustrate regulated, co-secretion of Aβ(1-40) and Aβ(1-42) with peptide neurotransmitters (galanin, enkephalin, and NPY) and catecholamine neurotransmitters (dopamine, norepinephrine, and epinephrine). Regulated secretion from chromaffin cells was stimulated by KCl depolarization and nicotine. Forskolin, stimulating cAMP, also induced co-secretion of Aβ peptides with peptide and catecholamine neurotransmitters. These data suggested the co-localization of Aβ with neurotransmitters in dense core secretory vesicles (DCSV) that store and secrete such chemical messengers. Indeed, Aβ was demonstrated to be present in DCSV with neuropeptide and catecholamine transmitters. Furthermore, the DCSV organelle contains APP and its processing proteases, β- and γ-secretases, that are necessary for production of Aβ. Thus, Aβ can be generated in neurotransmitter-containing DCSV. Human IMR32 neuroblastoma cells also displayed regulated secretion of Aβ(1-40) and Aβ(1-42) with the galanin neurotransmitter. These findings illustrate that Aβ peptides are present in neurotransmitter-containing DCSV, and undergo co-secretion with neuropeptide and catecholamine neurotransmitters that regulate brain functions. Copyright © 2013 Elsevier Inc. All rights reserved.

Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages.

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Maaike Kockx

Full Text Available Dynamins are fission proteins that mediate endocytic and exocytic membrane events and are pharmacological therapeutic targets. These studies investigate whether dynamin II regulates constitutive protein secretion and show for the first time that pharmacological inhibition of dynamin decreases secretion of apolipoprotein E (apoE and several other proteins constitutively secreted from primary human macrophages. Inhibitors that target recruitment of dynamin to membranes (MiTMABs or directly target the GTPase domain (Dyngo or Dynole series, dose- and time- dependently reduced the secretion of apoE. SiRNA oligo's targeting all isoforms of dynamin II confirmed the involvement of dynamin II in apoE secretion. Inhibition of secretion was not mediated via effects on mRNA or protein synthesis. 2D-gel electrophoresis showed that inhibition occurred after apoE was processed and glycosylated in the Golgi and live cell imaging showed that inhibited secretion was associated with reduced post-Golgi movement of apoE-GFP-containing vesicles. The effect was not restricted to macrophages, and was not mediated by the effects of the inhibitors on microtubules. Inhibition of dynamin also altered the constitutive secretion of other proteins, decreasing the secretion of fibronectin, matrix metalloproteinase 9, Chitinase-3-like protein 1 and lysozyme but unexpectedly increasing the secretion of the inflammatory mediator cyclophilin A. We conclude that pharmacological inhibitors of dynamin II modulate the constitutive secretion of macrophage apoE as a class effect, and that their capacity to modulate protein secretion may affect a range of biological processes.

Normal secretion and action of the gut incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide in young men with low birth weight

DEFF Research Database (Denmark)

Schou, Jakob Hagen; Pilgaard, Kasper; Vilsbøll, Tina

2005-01-01

polypeptide (GIP) in young LBW men (n = 24) and matched normal birth weight controls (NBW) (n = 25). RESULTS: LBW subjects were 5 cm shorter but had a body mass index similar to NBW. LBW subjects had significantly elevated fasting and postprandial plasma glucose, as well as postprandial (standard meal test......CONTEXT: Low birth weight (LBW) is associated with increased risk of type 2 diabetes mellitus. An impaired incretin effect was reported previously in type 2 diabetic patients. OBJECTIVE: We studied the secretion and action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic...

Glycoprotein Ibalpha signalling in platelet apoptosis and clearance

NARCIS (Netherlands)

van der Wal, E.

2010-01-01

Storage of platelets at low temperature reduces bacterial growth and might better preserve the haemostatic function of platelets than current procedures. Incubation at 0C is known to expose ?-N-acetyl-D-glucosamine-residues on glycoprotein (GP)Ibalpha inducing receptor-clustering and platelet

Adrenocorticotropic Hormone Secreting Pheochromocytoma Underlying Glucocorticoid Induced Pheochromocytoma Crisis

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Gil A. Geva

2018-01-01

Full Text Available Context. Pheochromocytomas are hormone secreting tumors of the medulla of the adrenal glands found in 0.1–0.5% of patients with hypertension. The vast majority of pheochromocytomas secrete catecholamines, but they have been occasionally shown to also secrete interleukins, calcitonin, testosterone, and in rare cases adrenocorticotropic hormone. Pheochromocytoma crisis is a life threatening event in which high levels of catecholamines cause a systemic reaction leading to organ failure. Case Description. A 70-year-old man was admitted with acute myocardial ischemia following glucocorticoid administration as part of an endocrine workup for an adrenal mass. Cardiac catheterization disclosed patent coronary arteries and he was discharged. A year later he returned with similar angina-like chest pain. During hospitalization, he suffered additional events of chest pain, shortness of breath, and palpitations following administration of glucocorticoids as preparation for intravenous contrast administration. Throughout his admission, the patient demonstrated both signs of Cushing’s syndrome and high catecholamine levels. Following stabilization of vital parameters and serum electrolytes, the adrenal mass was resected surgically and was found to harbor an adrenocorticotropic hormone secreting pheochromocytoma. This is the first documented case of adrenocorticotropic hormone secreting pheochromocytoma complicated by glucocorticoid induced pheochromocytoma crisis. Conclusion. Care should be taken when administering high doses of glucocorticoids to patients with suspected pheochromocytoma, even in a patient with concomitant Cushing’s syndrome.

Serum-SP/sub 1/-pregnancy-specific-. beta. -glycoprotein in choriocarcinoma and other neoplastic disease

Energy Technology Data Exchange (ETDEWEB)

Searle, F; Leake, B A; Bagshawe, K D; Dent, J [Charing Cross Group of Hospitals, London (UK)

1978-03-18

A radioimmunoassay for a placental glycoprotein, ..beta../sub 1/SP/sub 1/, capable of detecting 2 ..mu..g/l of the glycoprotein in serum was used to measure concentrations of ..beta../sub 1/SP/sub 1/ in patients with choriocarcinoma, teratoma, colonic cancer, breast cancer, and ovarian cancer. Twelve out of 94 (13%) healthy men and healthy non-pregnant women had detectable serum-..beta../sub 1/SP/sub 1/ concentrations. Concentrations up to 50,000 ..mu..g/l were found in the sera of patients with hydatidiform mole, invasive mole, choriocarcinoma, and malignant teratoma. ..beta../sub 1/-glycoprotein concentrations were generally much lower than corresponding concentrations of chorionic gonadotrophin which is the most reliable marker for trophoblastic tumors. In a few cases, however, ..beta../sub 1/-glycoprotein measurements may be useful in the detection of minimal residual tumor. The slightly raised values found in some patients with carcinoma of the colon, breast, or ovary seem unlikely to be useful for diagnostic purposes or for monitoring the course of these cancers.

Skin pathology and medical prognosis in medieval Europe: the secrets of Hippocrates.

Science.gov (United States)

Ackerman Smoller, L

2000-12-01

This article analyzes a medieval text known as The Secrets of Hippocrates. Neither secret (because of its wide circulation in manuscript and print) nor by Hippocrates, the work offered readers a means of offering a prognosis of impending death based on observable signs on the skin. Although the aphorisms that make up the text make little sense in a modern medical understanding, the Secrets of Hippocrates fits well within three medieval traditions: the tradition of secrets literature, the medieval medical tradition, and the tradition of medieval Christian views about the body. First, like other books of secrets, a genre to whose conventions the text closely adheres, the Secrets of Hippocrates offered a shortcut to socially useful knowledge: the ability to offer an accurate medical prognosis. Second, the treatise corresponded to the medieval physician's concern for the so-called nonnaturals, such as diet and exercise. Third, it fit with a medieval Christian notion that sickness and sin were related, as were sin and ugliness. Just as a leper's deformities were a window to his sinful soul, so skin pathologies could clue a medieval physician to the lethal disease hidden inside the body.

Rat macrophages: membrane glycoproteins in differentiation and function

NARCIS (Netherlands)

van den Berg, T. K.; Döpp, E. A.; Dijkstra, C. D.

2001-01-01

Macrophages (mphi) play a crucial role in the immune system. The rat offers unique advantages for studying the biology of mphi. Firstly, monoclonal antibodies (mAb) against many rat mphi surface glycoproteins have become available. These have not only demonstrated a considerable heterogeneity among

Non-opiate [beta]-endorphin fragments and dopamine--V [gamma]-type endorphins and prolactin secretion in rats

NARCIS (Netherlands)

Lamberts, S.W.J.; De Quijada, M.; Ree, J.M. van; Wied, D. de

1982-01-01

The effects on prolactin secretion of three peptide-derivatives of β-endorphin which show neuroleptic-like activities in rats were studied. Intravenous administration of γ-endorphin (β-endorphin (βE) 1–17) enhanced plasma prolactin levels. γ-Endorphin did not affect the prolactin secretion by

Electrophoretic demonstration of glycoproteins, lipoproteins, and phosphoproteins in human and bovine enamel

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D; Bøg-Hansen, T C

1990-01-01

Enamel proteins from fully mineralized human molars and from bovine tooth germs were separated by electrophoresis. The gels were stained for detection of glycoproteins, lipoproteins, and phosphoproteins. Glycoproteins were shown by periodic acid-Schiff staining and lectin blotting. In mature human...... enamel a number of high molecular weight proteins could be demonstrated after ethylenediaminetetra-acetic acid demineralization and subsequent Triton X-100 extraction. These proteins are suggested to be lipoproteins. Phosphoproteins could only be visualized in enamel matrix from the tooth germs....

Synaptotagmin-7 phosphorylation mediates GLP-1-dependent potentiation of insulin secretion from β-cells

DEFF Research Database (Denmark)

Wu, Bingbing; Wei, Shunhui; Petersen, Natalia

2015-01-01

Glucose stimulates insulin secretion from β-cells by increasing intracellular Ca(2+). Ca(2+) then binds to synaptotagmin-7 as a major Ca(2+) sensor for exocytosis, triggering secretory granule fusion and insulin secretion. In type-2 diabetes, insulin secretion is impaired; this impairment...... is ameliorated by glucagon-like peptide-1 (GLP-1) or by GLP-1 receptor agonists, which improve glucose homeostasis. However, the mechanism by which GLP-1 receptor agonists boost insulin secretion remains unclear. Here, we report that GLP-1 stimulates protein kinase A (PKA)-dependent phosphorylation...... of synaptotagmin-7 at serine-103, which enhances glucose- and Ca(2+)-stimulated insulin secretion and accounts for the improvement of glucose homeostasis by GLP-1. A phospho-mimetic synaptotagmin-7 mutant enhances Ca(2+)-triggered exocytosis, whereas a phospho-inactive synaptotagmin-7 mutant disrupts GLP-1...

Effect of expression of P-glycoprotein on technetium-99m methoxyisobutylisonitrile single photon emission computed tomography of brain tumors

Energy Technology Data Exchange (ETDEWEB)

Shibata, Yasushi; Matsumura, Akira; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2002-08-01

The expression of P-glycoprotein was investigated imunohistochemically in 26 brain tumor tissues and compared with the findings of technetium-99m methoxyisobutylisonitrile single photon emission computed tomography ({sup 99m}Tc-MIBI SPECT) to clarify the effect of P-glycoprotein on the diagnostic accuracy. P-glycoprotein labeling index of both tumor cells and vascular endothelial cells showed no clear relationship with the findings of {sup 99m}Tc-MIBI SPECT imaging. Expression of P-glycoprotein has no effect on the diagnostic accuracy of {sup 99m}Tc-MIBI SPECT. (author)

Changes in intestinal absorption of nutrients and brush border glycoproteins after total parenteral nutrition in rats.

Science.gov (United States)

Miura, S; Tanaka, S; Yoshioka, M; Serizawa, H; Tashiro, H; Shiozaki, H; Imaeda, H; Tsuchiya, M

1992-01-01

The effect of total parenteral nutrition on nutrients absorption and glycoprotein changes of brush border membrane was examined in rat small intestine. In total parenteral nutrition rats, a marked decrease in activity of brush border enzymes was observed mainly in the proximal and middle segments of the intestine. Galactose perfusion of jejunal segment showed that hexose absorption was significantly inhibited, while intestinal absorption of glycine or dipeptide, glycylglycine was not significantly affected by total parenteral nutrition treatment. When brush border membrane glycoprotein profile was examined by [3H]-glucosamine or [3H]-fucose incorporation into jejunal loops, significant changes were observed in the glycoprotein pattern of brush border membrane especially in the high molecular weight range over 120 kDa after total parenteral nutrition treatment, suggesting strong dependency of glycoprotein synthesis on luminal substances. Molecular weight of sucrase isomaltase in brush border membrane detected by specific antibody showed no significant difference, however, in total parenteral nutrition and control rats. Also, molecular weight of specific sodium glucose cotransporter of intestinal brush border membrane detected by selective photoaffinity labelling was not altered in total parenteral nutrition rats. It may be that prolonged absence of oral food intake may produce significant biochemical changes in brush border membrane glycoprotein and absorptive capacity of small intestine, but these changes were not observed in all brush border membrane glycoproteins. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1582592

Carcinoma-specific Ulex europaeus agglutinin-I binding glycoproteins of human colorectal carcinoma and its relation to carcinoembryonic antigen.

Science.gov (United States)

Matsushita, Y; Yonezawa, S; Nakamura, T; Shimizu, S; Ozawa, M; Muramatsu, T; Sato, E

1985-08-01

Glycoproteins binding to Ulex europaeus agglutinin-I (UEA-I) lectin, which recognizes the terminal alpha-L-fucose residue, were analyzed in 18 cases of human colorectal carcinoma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by the Western blotting method. In the distal large bowel (descending and sigmoid colon and rectum), high-molecular-weight glycoproteins binding to UEA-I existed in carcinoma tissue but not in normal mucosa. In the proximal large bowel (ascending and transverse colon), high-molecular-weight glycoproteins binding to UEA-I were found both in normal mucosa and in carcinoma tissue, whereas those from the carcinoma tissue had an apparently lower molecular weight as compared to the weight of those from the normal mucosa. Thus there is a biochemical difference in UEA-I binding glycoproteins between the normal mucosa and the carcinoma tissue, although in our previous histochemical study no difference was observed in UEA-I binding glycoproteins of the proximal large bowel between the carcinoma tissue and the normal mucosa. Furthermore, carcinoembryonic antigen from the carcinoma tissue was found to have the same electrophoretical mobility as the UEA-I binding glycoproteins.

Extra-oviductal expression of oviductal glycoprotein 1 in mouse ...

Indian Academy of Sciences (India)

2017-01-11

Jan 11, 2017 ... oestrogen-dependent protein, oviduct-specific glycoprotein. 1 (Ovgp1) also ... the tissues collected were testis, epididymis, prostate gland and seminal vesicle. ... The antigenic sites were unmasked by incuba- tion of sections ...

Modification of P-selectin glycoprotein ligand-1 with a natural killer cell-restricted sulfated lactosamine creates an alternate ligand for L-selectin

Science.gov (United States)

André, Pascale; Spertini, Olivier; Guia, Sophie; Rihet, Pascal; Dignat-George, Françoise; Brailly, Hervé; Sampol, José; Anderson, Paul J.; Vivier, Eric

2000-01-01

Natural killer (NK) cells are components of the innate immune system that can recognize and kill virally infected cells, tumor cells, and allogeneic cells without prior sensitization. NK cells also elaborate cytokines (e.g., interferon-γ and tumor necrosis factor-α) and chemokines (e.g., macrophage inflammatory protein-1α) that promote the acquisition of antigen-specific immunity. NK cell differentiation is accompanied by the cell surface expression of a mucin-like glycoprotein bearing an NK cell-restricted keratan sulfate-related lactosamine carbohydrate, the PEN5 epitope. Here, we report that PEN5 is a post-translational modification of P-selectin glycoprotein ligand-1 (PSGL-1). The PEN5 epitope creates on PSGL-1 a unique binding site for L-selectin, which is independent of PSGL-1 tyrosine sulfation. On the surface of NK cells, the expression of PEN5 is coordinated with the disappearance of L-selectin and the up-regulation of Killer cell Ig-like Receptors (KIR). These results indicate that NK cell differentiation is accompanied by the acquisition of a unique carbohydrate, PEN5, that can serve as part of a combination code to deliver KIR+ NK cells to specific tissues. PMID:10725346

Progranulin: At the interface of neurodegenerative and metabolic diseases

OpenAIRE

Nguyen, Andrew D.; Nguyen, Thi A.; Martens, Lauren Herl; Mitic, Laura L.; Farese, Robert V.

2013-01-01

Progranulin is a widely expressed, cysteine-rich, secreted glycoprotein originally discovered for its growth factor–like properties. Its subsequent identification as a causative gene for frontotemporal dementia (FTD), a devastating early-onset neurodegenerative disease, has catalyzed a surge of new discoveries about progranulin’s function in the brain. More recently, progranulin was recognized as an adipokine involved in diet-induced obesity and insulin resistance, revealing its metabolic fun...

Celastraceae sesquiterpenes as a new class of modulators that bind specifically to human P-glycoprotein and reverse cellular multidrug resistance.

Science.gov (United States)

Muñoz-Martínez, Francisco; Lu, Peihua; Cortés-Selva, Fernando; Pérez-Victoria, José María; Jiménez, Ignacio A; Ravelo, Angel G; Sharom, Frances J; Gamarro, Francisco; Castanys, Santiago

2004-10-01

Overexpression of ABCB1 (MDR1) P-glycoprotein, a multidrug efflux pump, is one mechanism by which tumor cells may develop multidrug resistance (MDR), preventing the successful chemotherapeutic treatment of cancer. Sesquiterpenes from Celastraceae family are natural compounds shown previously to reverse MDR in several human cancer cell lines and Leishmania strains. However, their molecular mechanism of reversion has not been characterized. In the present work, we have studied the ability of 28 dihydro-beta-agarofuran sesquiterpenes to reverse the P-glycoprotein-dependent MDR phenotype and elucidated their molecular mechanism of action. Cytotoxicity assays using human MDR1-transfected NIH-3T3 cells allowed us to select the most potent sesquiterpenes reversing the in vitro resistance to daunomycin and vinblastine. Flow cytometry experiments showed that the above active compounds specifically inhibited drug transport activity of P-glycoprotein in a saturable, concentration-dependent manner (K(i) down to 0.24 +/- 0.01 micromol/L) but not that of ABCC1 (multidrug resistance protein 1; MRP1), ABCC2 (MRP2), and ABCG2 (breast cancer resistance protein; BCRP) transporters. Moreover, sesquiterpenes inhibited at submicromolar concentrations the P-glycoprotein-mediated transport of [(3)H]colchicine and tetramethylrosamine in plasma membrane from CH(R)B30 cells and P-glycoprotein-enriched proteoliposomes, supporting that P-glycoprotein is their molecular target. Photoaffinity labeling in plasma membrane and fluorescence spectroscopy experiments with purified protein suggested that sesquiterpenes interact with transmembrane domains of P-glycoprotein. Finally, sesquiterpenes modulated P-glycoprotein ATPase-activity in a biphasic, concentration-dependent manner: they stimulated at very low concentrations but inhibited ATPase activity as noncompetitive inhibitors at higher concentrations. Sesquiterpenes from Celastraceae are promising P-glycoprotein modulators with potential

Onset of apoprotein E secretion during differentiation of mouse bone marrow-derived mononuclear phagocytes

International Nuclear Information System (INIS)

Werb, Z.; Chin, J.R.

1983-01-01

A number of macrophage functions were sequentially expressed when the bone marrow precursors of mononuclear phagocytes differentiated in culture in the presence of a specific growth factor, colony-stimulating factor-1. The authors defined the expression of apoprotein E (ApoE), a major secreted protein of resident peritoneal macrophages, during maturation of adherent bone marrow-derived mononuclear phagocytes into macrophages. By 5 d the bone marrow macrophages were active secretory cells, but few cells contained intracellular immunoreactive ApoE, and little, if any, ApoE was secreted. ApoE secretion was initiated at 9 d, and this correlated with an increase in the percentage of macrophages containing intracellular ApoE. The onset of ApoE secretion was selective, and little change occurred in the other major secreted proteins detected by [ 35 S]methionine incorporation. In parallel, the high rate of plasminogen activator secretion, which peaked at 7 d, decreased markedly. ApoE secretion was not associated with altered expression of the macrophage surface antigen, la, or with secretion of fibronectin. Virtually all cells in independent colonies of bone marrow-derived macrophages eventually expressed ApoE. The proliferating monocyte/macrophage-like cell lines P388D1, J774.2, WHEI-3, RAW 264.1, and MGI.D + secreted little or no ApoE. These data establish that ApoE secretion is developmentally regulated

Glycoprotein H of herpes simplex virus type 1 requires glycoprotein L for transport to the surfaces of insect cells

NARCIS (Netherlands)

Westra, DF; Glazenburg, KL; Harmsen, MC; Tiran, A; Scheffer, AJ; Welling, GW; The, TH; WellingWester, S

In mammalian cells, formation of heterooligomers consisting of the glycoproteins H and L (gH and gL) of herpes simplex virus type 1 is essential for the cell-to-cell spread of virions and for the penetration of virions into cells. We examined whether formation of gH1/gL1 heterooligomers and cell

Interaction of E2 glycoprotein with heparan sulfate is crucial for cellular infection of Sindbis virus.

Directory of Open Access Journals (Sweden)

Wuyang Zhu

Full Text Available Cell culture-adapted strains of Sindbis virus (SINV initially attach to cells by the ability to interact with heparan sulfate (HS through selective mutation for positively charged amino acid (aa scattered in E2 glycoprotein (W. B. Klimstra, K. D. Ryman, and R. E. Johnston, J. Virol. 72: 7357-7366, 1998. Here we have further confirmed that interaction of E2 protein with HS is crucial for cellular infection of SINV based on the reverse genetic system of XJ-160 virus, a Sindbis-like virus (SINLV. Both SINV YN87448 and SINLV XJ-160 displayed similar infectivity on BHK-21, Vero, or C6/36 cells, but XJ-160 failed to infect mouse embryonic fibroblast (MEF cells. The molecular mechanisms underlying the selective infectivity of XJ-160 were approached by substituting the E1, E2, or both genes of XJ-160 with that of YN87448, and the chimeric virus was denominated as XJ-160/E1, XJ-160/E2, or XJ-160/E1E2, respectively. In contrast to the parental XJ-160, all chimeric viruses became infectious to wild-type MEF cells (MEF-wt. While MEF-Ext(-/- cells, producing shortened HS chains, were resistant not only to XJ-160, but also to YN87448 as well as the chimeric viruses, indicating that the inability of XJ-160 to infect MEF-wt cells likely due to its incompetent discrimination of cellular HS. Treatment with heparin or HS-degrading enzyme resulted in a substantial decrease in plaque formation by YN87448, XJ-160/E2, and XJ-160/E1E2, but had marginal effect on XJ-160 and XJ-160/E1, suggesting that E2 glycoprotein from YN87448 plays a more important role than does E1 in mediating cellular HS-related cell infection. In addition, the peptide containing 145-150 aa from E2 gene of YN87448 specifically bound to heparin, while the corresponding peptide from the E2 gene of XJ-160 essentially showed no binding to heparin. As a new dataset, these results clearly confirm an essential role of E2 glycoprotein, especially the domain of 145-150 aa, in SINV cellular infection

MDR1 P-glycoprotein transports endogenous opioid peptides

NARCIS (Netherlands)

Oude Elferink, R. P.; Zadina, J.

2001-01-01

MDR1 P-glycoprotein is generally regarded as an efflux pump for amphipathic toxic compounds. The question remains, however, whether certain endogenous compounds are also substrates for this transporter. Certain peptides have been shown to interact with MDR1 Pgp as well and we have therefore

Enteroendocrine secretion of gut hormones in diabetes, obesity and after bariatric surgery

DEFF Research Database (Denmark)

Holst, Jens Juul

2013-01-01

Gastric bypass surgery is associated with a major weight loss and often causes remission in patients with type 2 diabetes. Surgery is also associated with dramatic increases in the secretion of the gut hormones, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), both of which regulate appetite...... and food intake, while GLP-1 in addition functions as an incretin hormone, stimulating insulin secretion. It has been possible to probe the role of GLP-1 for the diabetes resolution after gastric bypass using a GLP-1 receptor antagonist, and it is clear that the enhanced beta cell sensitivity to glucose...... which underlies the enhanced insulin secretion in the patients after the operation depends critically on the increased GLP-1 secretion. Both hormones seem to contribute importantly to the reduction in food intake after bypass and, therefore, to the weight loss. Currently, there are no data to indicate...

Expression of variable viruses as herpes simplex glycoprotein D and varicella zoster gE glycoprotein using a novel plasmid based expression system in insect cell

Directory of Open Access Journals (Sweden)

A.M. Al-Sulaiman

2017-11-01

Full Text Available Several prokaryotic and eukaryotic expression systems have been used for in vitro production of viruses’ proteins. However eukaryotic expression system was always the first choice for production of proteins that undergo post-translational modification such as glycosylation. Recombinant baculoviruses have been widely used as safe vectors to express heterologous genes in the culture of insect cells, but the manipulation involved in creating, titrating, and amplifying viral stocks make it time consuming and laborious. Therefore, to facilitate rapid expression in insect cell, a plasmid based expression system was used to express herpes simplex type 1 glycoprotein D (HSV-1 gD and varicella zoster glycoprotein E (VZV gE. Recombinant plasmids were generated, transfected into insect cells (SF9, and both glycoproteins were expressed 48 h post-infection. A protein with approximately molecular weight of 64-kDa and 98-kDa for HSV-1 gD and VZV gE respectively was expressed and confirmed by SDS. Proteins were detected in insect cells cytoplasm and outer membrane by immunofluorescence. The antigenicity and immunoreactivity of each protein were confirmed by immunoblot and ELISA. Results suggest that this system can be an alternative to the traditional baculovirus expression for small scale expression system in insect cells.

Quantum strongly secure ramp secret sharing

DEFF Research Database (Denmark)

Zhang, Paul; Matsumoto, Rytaro Yamashita

2015-01-01

Quantum secret sharing is a scheme for encoding a quantum state (the secret) into multiple shares and distributing them among several participants. If a sufficient number of shares are put together, then the secret can be fully reconstructed. If an insufficient number of shares are put together...... however, no information about the secret can be revealed. In quantum ramp secret sharing, partial information about the secret is allowed to leak to a set of participants, called an unqualified set, that cannot fully reconstruct the secret. By allowing this, the size of a share can be drastically reduced....... This paper introduces a quantum analog of classical strong security in ramp secret sharing schemes. While the ramp secret sharing scheme still leaks partial information about the secret to unqualified sets of participants, the strong security condition ensures that qudits with critical information can...

Impact of alg3 gene deletion on growth, development, pigment production, protein secretion, and functions of recombinant Trichoderma reesei cellobiohydrolases in Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Dai, Ziyu; Aryal, Uma K.; Shukla, Anil; Qian, Wei-Jun; Smith, Richard D.; Magnuson, Jon K.; Adney, William S.; Beckham, Gregg T.; Brunecky, Roman; Himmel, Michael E.; Decker, Stephen R.; Ju, Xiaohui; Zhang, Xiao; Baker, Scott E.

2013-12-01

ALG3 is a Family 58 glycosyltransferase enzyme involved in early N-linked glycan synthesis. Here, we investigated the effect of the alg3 gene disruption on growth, development, metabolism, and protein secretion in Aspergillus niger. The alg3 gene deletion resulted in a significant reduction of growth on complete (CM) and potato dextrose agar (PDA) media and a substantial reduction of spore production on CM. It also delayed spore germination in the liquid cultures of both CM and PDA media, but led to a significant accumulation of red pigment on both CM and liquid modified minimal medium (MM) supplemented with yeast extract. The relative abundance of 55 proteins of the total 190 proteins identified in the secretome was significantly different as a result of alg3 gene deletion. Comparison of a Trichoderma reesei cellobiohydrolase (Cel7A) heterologously expressed in A. niger parental and Δalg3 strains showed that the recombinant Cel7A expressed in the mutant background was smaller in size than that from the parental strains. This study suggests that ALG3 is critical for growth and development, pigment production, and protein secretion in A. niger. Functional analysis of recombinant Cel7A with aberrant glycosylation demonstrates the feasibility of this alternative approach to evaluate the role of N-linked glycosylation in glycoprotein secretion and function.

Low rate doses effects of gamma radiation on glycoproteins of transmembrane junctions in fibroblasts

International Nuclear Information System (INIS)

Bringas, J.E.; Caceres, J.L.

1996-01-01

Glycoproteins of trans-membrane junctions are molecules that help to bind cells with the extracellular matrix. Integrins are the most important trans-membrane molecules among others. The damage of gamma radiation on those proteins could be an important early event that causes membrane abnormalities which may lead to cell malfunction and cancer induced by radiation due to cell dissociation. Randomized blocks with 3 repetitions of mouse embryo fibroblast cultures, were irradiated with Cobalt-60 gamma rays, during 20 days. Biological damage to glycoproteins and integrins was evaluated by cellular growth and fibroblast proliferative capacity. Integrins damage was studied by isolation by column immunoaffinity chromatography migrated on SDS-Page under reducing and non reducing conditions, and inhibition of integrins extracellular matrix adhesion by monoclonal antibodies effect. The dose/rate (0.05 Gy/day-0.2 Gy/day) of gamma given to cells did not show damage evidence on glycoproteins and integrins. If damage happened, it was repaired by cells very soon, was delayed by continuous cellular division or by glycoproteins characteristic of being multiple extracellular ligatures. Bio effects became more evident with an irradiation time greater than 20 days or a high dose/rate. (authors). 6 refs

Dynamic secrets in communication security

CERN Document Server

Xiao, Sheng; Towsley, Donald

2013-01-01

Dynamic secrets are constantly generated and updated from messages exchanged between two communication users. When dynamic secrets are used as a complement to existing secure communication systems, a stolen key or password can be quickly and automatically reverted to its secret status without disrupting communication. 'Dynamic Secrets in Communication Security' presents unique security properties and application studies for this technology. Password theft and key theft no longer pose serious security threats when parties frequently use dynamic secrets. This book also illustrates that a dynamic

A review on the relation between the brain-serum concentration ratio of drugs and the influence of P-glycoprotein

DEFF Research Database (Denmark)

Ejsing, Thomas Broeng; Morling, Niels; Linnet, Kristian

2007-01-01

This overview on the brain-serum relationship for drugs illustrates the importance of the drug transporter P-glycoprotein at the blood-brain barrier. Generally, an inverse relationship exists between the magnitude of the brain-serum ratio and the influence of P-glycoprotein. Concerning the pharma...... the pharmacogenomics of P-glycoprotein, no clear effect of single nucleotide polymorphisms (SNPs) has been demonstrated in humans....

Developmental and functional significance of the CSF-1 proteoglycan chondroitin sulfate chain

OpenAIRE

Nandi, Sayan; Akhter, Mohammed P.; Seifert, Mark F.; Dai, Xu-Ming; Stanley, E. Richard

2006-01-01

The primary macrophage growth factor, colony-stimulating factor-1 (CSF-1), is homodimeric and exists in 3 biologically active isoforms: a membrane-spanning, cell-surface glycoprotein (csCSF-1) and secreted glycoprotein (sgCSF-1) and proteoglycan (spCSF-1) isoforms. To investigate the in vivo role of the chondroitin sulfate glycosaminoglycan (GAG) chain of spCSF-1, we created mice that exclusively express, in a normal tissue-specific and developmental manner, either the secreted precursor of s...

Mucin secretion induced by titanium dioxide nanoparticles.

Directory of Open Access Journals (Sweden)

Eric Y T Chen

2011-01-01

Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

Ebola virus glycoprotein directly triggers T lymphocyte death despite of the lack of infection.

Science.gov (United States)

Iampietro, Mathieu; Younan, Patrick; Nishida, Andrew; Dutta, Mukta; Lubaki, Ndongala Michel; Santos, Rodrigo I; Koup, Richard A; Katze, Michael G; Bukreyev, Alexander

2017-05-01

Fatal outcomes of Ebola virus (EBOV) infections are typically preceded by a 'sepsis-like' syndrome and lymphopenia despite T cells being resistant to Ebola infection. The mechanisms that lead to T lymphocytes death remain largely unknown; however, the degree of lymphopenia is highly correlative with fatalities. Here we investigated whether the addition of EBOV or its envelope glycoprotein (GP) to isolated primary human CD4+ T cells induced cell death. We observed a significant decrease in cell viability in a GP-dependent manner, which is suggestive of a direct role of GP in T cell death. Using immunoprecipitation assays and flow cytometry, we demonstrate that EBOV directly binds to CD4+ T cells through interaction of GP with TLR4. Transcriptome analysis revealed that the addition of EBOV to CD4+ T cells results in the significant upregulation of pathways associated with interferon signaling, pattern recognition receptors and intracellular activation of NFκB signaling pathway. Both transcriptome analysis and specific inhibitors allowed identification of apoptosis and necrosis as mechanisms associated with the observed T cell death following exposure to EBOV. The addition of the TLR4 inhibitor CLI-095 significantly reduced CD4+ T cell death induced by GP. EBOV stimulation of primary CD4+ T cells resulted in a significant increase in secreted TNFα; inhibition of TNFα-mediated signaling events significantly reduced T cell death while inhibitors of both necrosis and apoptosis similarly reduced EBOV-induced T cell death. Lastly, we show that stimulation with EBOV or GP augments monocyte maturation as determined by an overall increase in expression levels of markers of differentiation. Subsequently, the increased rates of cellular differentiation resulted in higher rates of infection further contributing to T cell death. These results demonstrate that GP directly subverts the host's immune response by increasing the susceptibility of monocytes to EBOV infection and

Cryptanalysis of PRESENT-like ciphers with secret S-boxes

DEFF Research Database (Denmark)

Borghoff, Julia; Knudsen, Lars Ramkilde; Leander, Gregor

2011-01-01

At Eurocrypt 2001, Biryukov and Shamir investigated the security of AES-like ciphers where the substitutions and affine transformations are all key-dependent and successfully cryptanalysed two and a half rounds. This paper considers PRESENT-like ciphers in a similar manner. We focus on the settings...... where the S-boxes are key dependent, and repeated for every round. We break one particular variant which was proposed in 2009 with practical complexity in a chosen plaintext/chosen ciphertext scenario. Extrapolating these results suggests that up to 28 rounds of such ciphers can be broken. Furthermore...

A hybrid monolithic column based on boronate-functionalized graphene oxide nanosheets for online specific enrichment of glycoproteins.

Science.gov (United States)

Zhou, Chanyuan; Chen, Xiaoman; Du, Zhuo; Li, Gongke; Xiao, Xiaohua; Cai, Zongwei

2017-05-19

A hybrid monolithic column based on aminophenylboronic acid (APBA)-functionalized graphene oxide (GO) has been developed and used for selective enrichment of glycoproteins. The APBA/GO composites were homogeneously incorporated into a polymer monolithic column with the help of oligomer matrix and followed by in situ polymerization. The effect of dispersion of APBA/GO composites in the polymerization mixture on the performance of the monolithic column was explored in detail. The presence of graphene oxide not only enlarged the BET surface area from 6.3m 2 /g to 169.4m 2 /g, but also provided abundant boronic acid moieties for glycoprotein extraction, which improved the enrichment selectivity and efficiency for glycoproteins. The APBA/GO hybrid monolithic column was incorporated into a sequential injection system, which facilitated online extraction of proteins. Combining the superior properties of extraordinary surface area of GO and the affinity interaction of APBA to glycoproteins, the APBA/GO hybrid monolithic column showed higher enrichment factors for glycoproteins than other proteins without cis-diol-containing groups. Also, under comparable or even shorter processing time and without the addition of any organic solvent, it showed higher binding capacity toward glycoproteins compared with the conventional boronate affinity monolithic column. The practical applicability of this system was demonstrated by processing of egg white samples for extraction of ovalbumin and ovotransferrin, and satisfactory results were obtained by assay with SDS-PAGE. Copyright © 2017 Elsevier B.V. All rights reserved.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

Energy Technology Data Exchange (ETDEWEB)

Lee, Je Min, E-mail: jemin@knu.ac.kr [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of); Department of Horticultural Science, Kyungpook National University, Daegu (Korea, Republic of); Lee, Sang-Jik [Biotechnology Institute, Nongwoo Bio Co, Ltd, Yeoju (Korea, Republic of); Department of Plant Biology, Cornell University, Ithaca, NY (United States); Rose, Jocelyn K.C. [Department of Plant Biology, Cornell University, Ithaca, NY (United States); Yeam, Inhwa [Department of Horticulture and Breeding, Andong National University, Andong (Korea, Republic of); Kim, Byung-Dong [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of)

2014-04-18

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

International Nuclear Information System (INIS)

Lee, Je Min; Lee, Sang-Jik; Rose, Jocelyn K.C.; Yeam, Inhwa; Kim, Byung-Dong

2014-01-01

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening

Little enhancement of meal-induced glucagon-like peptide 1 secretion in Japanese

DEFF Research Database (Denmark)

Yabe, Daisuke; Kuroe, Akira; Lee, Soushou

2010-01-01

with or without type 2 diabetes (T2DM). Seventeen Japanese healthy controls and 18 age-matched and untreated patients with T2DM of short duration participated in the present study. Fasting levels of total GPL-1 were similar between the two groups (approximately 15 pM), and intact GLP-1 levels were considerably...... are considerably low in the Japanese and that meal-induced enhancement of GLP-1 secretion is negligible in the Japanese. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00010.x, 2010).......Although glucose-dependent insulinotropic polypeptide (GIP) levels have been characterized previously, GLP-1 levels in Asians remain unclear. Here, we investigate total and intact levels of GLP-1, as well as GIP during oral glucose and meal tolerance tests (OGTT and MTT) in Japanese patients...

Host cell tropism mediated by Australian bat lyssavirus envelope glycoproteins.

Science.gov (United States)

Weir, Dawn L; Smith, Ina L; Bossart, Katharine N; Wang, Lin-Fa; Broder, Christopher C

2013-09-01

Australian bat lyssavirus (ABLV) is a rhabdovirus of the lyssavirus genus capable of causing fatal rabies-like encephalitis in humans. There are two variants of ABLV, one circulating in pteropid fruit bats and another in insectivorous bats. Three fatal human cases of ABLV infection have been reported with the third case in 2013. Importantly, two equine cases also arose in 2013; the first occurrence of ABLV in a species other than bats or humans. We examined the host cell entry of ABLV, characterizing its tropism and exploring its cross-species transmission potential using maxGFP-encoding recombinant vesicular stomatitis viruses that express ABLV G glycoproteins. Results indicate that the ABLV receptor(s) is conserved but not ubiquitous among mammalian cell lines and that the two ABLV variants can utilize alternate receptors for entry. Proposed rabies virus receptors were not sufficient to permit ABLV entry into resistant cells, suggesting that ABLV utilizes an unknown alternative receptor(s). Published by Elsevier Inc.

Immunoglobins in mammary secretions

DEFF Research Database (Denmark)

Hurley, W L; Theil, Peter Kappel

2013-01-01

Immunoglobulins secreted in colostrum and milk by the lactating mammal are major factors providing immune protection to the newborn. Immunoglobulins in mammary secretions represent the cumulative immune response of the lactating animal to exposure to antigenic stimulation that occurs through...... the immunoglobulins found in mammary secretions in the context of their diversity of structure, origin, mechanisms of transfer, and function....

Thiolated polymers: evidence for the formation of disulphide bonds with mucus glycoproteins.

Science.gov (United States)

Leitner, Verena M; Walker, Greg F; Bernkop-Schnürch, Andreas

2003-09-01

Disulphide bonds between thiolated polymers (thiomers) and cysteine-rich subdomains of mucus glycoproteins are supposed to be responsible for the enhanced mucoadhesive properties of thiomers. This study set out to provide evidence for these covalent interactions using poly(acrylic acid)-cysteine conjugates of 2 and 450 kDa (PAA2-Cys, PAA450-Cys) displaying 402.5-776.0 micromol thiol groups per gram polymer. The effect of the disulphide bond breaker cysteine on thiomer-mucin disulphide bonds was monitored by (1) mucoadhesion studies and (2) rheological studies. Furthermore, (3) diffusion studies and (4) gel filtration studies were performed with thiomer-mucus mixtures. The addition of cysteine significantly (Ppolymer. Gel filtration studies showed that PAA2-Cys was able to form disulphide bonds with mucin glycoproteins resulting in an altered elution profile of the mucin/PAA2-Cys mixture in comparison to mucin alone or mucin/PAA2 mixture. According to these results, the study provides evidence for the formation of covalent bonds between thiomer and mucus glycoproteins.

Cytoplasmic tail domain of glycoprotein B is essential for HHV-6 infection

Energy Technology Data Exchange (ETDEWEB)

Mahmoud, Nora F. [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Faculty of Pharmacy, Suez Canal University, Ismailia (Egypt); Jasirwan, Chyntia [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Division of Hepatobiliary, Department of Internal Medicine, Faculty of Medicine, University of Indonesia (Indonesia); Kanemoto, Satoshi; Wakata, Aika; Wang, Bochao; Hata, Yuuki [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Nagamata, Satoshi [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe (Japan); Kawabata, Akiko [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Tang, Huamin [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Immunology, Nanjing Medical University, Nanjing (China); Mori, Yasuko, E-mail: ymori@med.kobe-u.ac.jp [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan)

2016-03-15

Human herpesvirus 6 (HHV-6) glycoprotein B (gB) is an abundantly expressed viral glycoprotein required for viral entry and cell fusion, and is highly conserved among herpesviruses. The present study examined the function of HHV-6 gB cytoplasmic tail domain (CTD). A gB CTD deletion mutant was constructed which, in contrast to its revertant, could not be reconstituted. Moreover, deletion of gB cytoplasmic tail impaired the intracellular transport of gB protein to the trans-Golgi network (TGN). Taken together, these results suggest that gB CTD is critical for HHV-6 propagation and important for intracellular transportation. - Highlights: • Glycoprotein B (gB) is highly conserved among herpesviruses. • HHV-6 gB is also abundantly expressed in virions. • In the present study, we showed the function of HHV-6 gB cytoplasmic tail domain (CTD). • We found that deletion of gB CTD impairs the intracellular transport of gB protein to the trans-Golgi network (TGN), and CTD of gB is critical for HHV-6 propagation.

Cytoplasmic tail domain of glycoprotein B is essential for HHV-6 infection

International Nuclear Information System (INIS)

Mahmoud, Nora F.; Jasirwan, Chyntia; Kanemoto, Satoshi; Wakata, Aika; Wang, Bochao; Hata, Yuuki; Nagamata, Satoshi; Kawabata, Akiko; Tang, Huamin; Mori, Yasuko

2016-01-01

Human herpesvirus 6 (HHV-6) glycoprotein B (gB) is an abundantly expressed viral glycoprotein required for viral entry and cell fusion, and is highly conserved among herpesviruses. The present study examined the function of HHV-6 gB cytoplasmic tail domain (CTD). A gB CTD deletion mutant was constructed which, in contrast to its revertant, could not be reconstituted. Moreover, deletion of gB cytoplasmic tail impaired the intracellular transport of gB protein to the trans-Golgi network (TGN). Taken together, these results suggest that gB CTD is critical for HHV-6 propagation and important for intracellular transportation. - Highlights: • Glycoprotein B (gB) is highly conserved among herpesviruses. • HHV-6 gB is also abundantly expressed in virions. • In the present study, we showed the function of HHV-6 gB cytoplasmic tail domain (CTD). • We found that deletion of gB CTD impairs the intracellular transport of gB protein to the trans-Golgi network (TGN), and CTD of gB is critical for HHV-6 propagation.

Neural glycoprotein M6a is released in extracellular vesicles and modulated by chronic stressors in blood

OpenAIRE

Monteleone, Melisa C.; Billi, Silvia C.; Brocco, Marcela A.; Frasch, Alberto C.

2017-01-01

Membrane neuronal glycoprotein M6a is highly expressed in the brain and contributes to neural plasticity promoting neurite growth and spine and synapse formation. We have previously showed that chronic stressors alter hippocampal M6a mRNA levels in rodents and tree shrews. We now show that M6a glycoprotein can be detected in mouse blood. M6a is a transmembrane glycoprotein and, as such, unlikely to be free in blood. Here we demonstrate that, in blood, M6a is transported in extracellular vesic...

Glycoprotein fucosylation is increased in seminal plasma of subfertile men

Directory of Open Access Journals (Sweden)

Beata Olejnik

2015-04-01

Full Text Available Fucose, the monosaccharide frequent in N- and O-glycans, is a part of Lewis-type antigens that are known to mediate direct sperm binding to the zona pellucida. Such interaction was found to be inhibited in vitroby fucose-containing oligo- and polysaccharides, as well as neoglycoproteins. The objective of this study was to screen seminal plasma proteins of infertile/subfertile men for the content and density of fucosylated glycoepitopes, and compare them to samples of fertile normozoospermic subjects. Seminal proteins were separated in polyacrylamide gel electrophoresis and blotted onto nitrocellulose membrane and probed with fucose-specific Aleuria aurantia lectin (AAL. Twelve electrophoretic bands were selected for quantitative densitometric analysis. It was found that the content, and especially the density of fucosylated glycans, were higher in glycoproteins present in seminal plasma of subfertile men. No profound differences in fucosylation density were found among the groups of normozoospermic, oligozoospermic, asthenozoospermic, and oligoasthenozoospermic subfertile men. According to the antibody probing, AAL-reactive bands can be attributed to male reproductive tract glycoproteins, including prostate-specific antigen, prostatic acid phosphatase, glycodelin and chorionic gonadotropin. Fibronectin, α1 -acid glycoprotein, α1 -antitrypsin, immunoglobulin G and antithrombin III may also contribute to this high fucosylation. It is suggested that the abundant fucosylated glycans in the sperm environment could interfere with the sperm surface and disturb the normal course of the fertilization cascade.

Matroids and quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Sarvepalli, Pradeep; Raussendorf, Robert

2010-01-01

A secret-sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret-sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret-sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum-secret-sharing schemes. In addition to providing a new perspective on quantum-secret-sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum-secret-sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum-secret-sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure-state quantum-secret-sharing scheme with information rate 1.

Extracellular secretion of recombinant proteins

Science.gov (United States)

Linger, Jeffrey G.; Darzins, Aldis

2014-07-22

Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

Separation and identification of carp pituitary proteins and glycoproteins

Czech Academy of Sciences Publication Activity Database

Ryšlavá, H.; Janatová, M.; Čalounová, G.; Selicharová, Irena; Barthová, J.; Barth, Tomislav

2005-01-01

Roč. 50, č. 9 (2005), 430-437 ISSN 1212-1819 R&D Projects: GA MZe(CZ) QF3028 Institutional research plan: CEZ:AV0Z4055905 Keywords : carp hormones * glycoproteins * oligosaccharide chains Subject RIV: CE - Biochemistry Impact factor: 0.254, year: 2005

Comparative Studies of Vertebrate Platelet Glycoprotein 4 (CD36

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Roger S. Holmes

2012-09-01

Full Text Available Platelet glycoprotein 4 (CD36 (or fatty acyl translocase [FAT], or scavenger receptor class B, member 3 [SCARB3] is an essential cell surface and skeletal muscle outer mitochondrial membrane glycoprotein involved in multiple functions in the body. CD36 serves as a ligand receptor of thrombospondin, long chain fatty acids, oxidized low density lipoproteins (LDLs and malaria-infected erythrocytes. CD36 also influences various diseases, including angiogenesis, thrombosis, atherosclerosis, malaria, diabetes, steatosis, dementia and obesity. Genetic deficiency of this protein results in significant changes in fatty acid and oxidized lipid uptake. Comparative CD36 amino acid sequences and structures and CD36 gene locations were examined using data from several vertebrate genome projects. Vertebrate CD36 sequences shared 53–100% identity as compared with 29–32% sequence identities with other CD36-like superfamily members, SCARB1 and SCARB2. At least eight vertebrate CD36 N-glycosylation sites were conserved which are required for membrane integration. Sequence alignments, key amino acid residues and predicted secondary structures were also studied. Three CD36 domains were identified including cytoplasmic, transmembrane and exoplasmic sequences. Conserved sequences included N- and C-terminal transmembrane glycines; and exoplasmic cysteine disulphide residues; TSP-1 and PE binding sites, Thr92 and His242, respectively; 17 conserved proline and 14 glycine residues, which may participate in forming CD36 ‘short loops’; and basic amino acid residues, and may contribute to fatty acid and thrombospondin binding. Vertebrate CD36 genes usually contained 12 coding exons. The human CD36 gene contained transcription factor binding sites (including PPARG and PPARA contributing to a high gene expression level (6.6 times average. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate CD36 gene with vertebrate

Human platelet glycoprotein IX: An adhesive prototype of leucine-rich glycoproteins with flank-center-flank structures

International Nuclear Information System (INIS)

Hickey, M.J.; Williams, S.A.; Roth, G.J.

1989-01-01

The glycoprotein (GP) Ib-IX complex on the surface of human platelets functions as the von Willebrand factor receptor and mediates von Willebrand factor-dependent platelet adhesion to blood vessels. GPIX is a relatively small (M r , 17,000) protein that may provide for membrane insertion and orientation of the larger component of the complex. GPIb (M r , 165,000). Using antibody screening, the authors cloned a cDNA encoding GPIX from a human erythroleukemia cell cDNA library constructed in phage λgt11. Lacking a 5' untranslated region and start codon, the cDNA sequence includes 604 nucleotides, beginning with 495 bases at the 5' end coding for 165 amino acids, followed by a stop codon and 106 noncoding bases at the 3' end. By Northern blot analysis, the GPIX cDNA hybridizes with a single 1.0-kilobase species of platelet poly(A) + RNA. Translation of the cDNA sequence gives a predicted protein sequence beginning with a truncated putative signal sequence of 5 amino acids followed by a sequence of 17 amino acids matching that determined directly by Edman degradation of intact GPIX. GPIX contains a leucine-rich glycoprotein (LRG) sequence of 24 amino acids similar to conserved LRG sequences in GPIb and other proteins from humans, Drosophila, and yeast. The role of the flank-LRG center-flank structure in the evolution and function of the LRG proteins remains to be defined

Cancer Biomarker Discovery: Lectin-Based Strategies Targeting Glycoproteins

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David Clark

2012-01-01

Full Text Available Biomarker discovery can identify molecular markers in various cancers that can be used for detection, screening, diagnosis, and monitoring of disease progression. Lectin-affinity is a technique that can be used for the enrichment of glycoproteins from a complex sample, facilitating the discovery of novel cancer biomarkers associated with a disease state.

The Lyssavirus glycoprotein: A key to cross-immunity.

Science.gov (United States)

Buthelezi, Sindisiwe G; Dirr, Heini W; Chakauya, Ereck; Chikwamba, Rachel; Martens, Lennart; Tsekoa, Tsepo L; Stoychev, Stoyan H; Vandermarliere, Elien

2016-11-01

Rabies is an acute viral encephalomyelitis in warm-blooded vertebrates, caused by viruses belonging to Rhabdovirus family and genus Lyssavirus. Although rabies is categorised as a neglected disease, the rabies virus (RABV) is the most studied amongst Lyssaviruses which show nearly identical infection patterns. In efforts to improving post-exposure prophylaxis, several anti-rabies monoclonal antibodies (mAbs) targeting the glycoprotein (G protein) sites I, II, III and G5 have been characterized. To explore cross-neutralization capacity of available mAbs and discover new possible B-cell epitopes, we have analyzed all available glycoprotein sequences from Lyssaviruses with a focus on sequence variation and conservation. This information was mapped on the structure of a representative G protein. We proposed several possible cross-neutralizing B-cell epitopes (GUVTTTF, WLRTV, REECLD and EHLVVEEL) in complement to the already well-characterized antigenic sites. The research could facilitate development of novel cross-reactive mAbs against RABV and even more broad, against possibly all Lyssavirus members. Copyright © 2016 Elsevier Inc. All rights reserved.

Reduction of VLDL secretion decreases cholesterol excretion in niemann-pick C1-like 1 hepatic transgenic mice.

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Stephanie M Marshall

Full Text Available An effective way to reduce LDL cholesterol, the primary risk factor of atherosclerotic cardiovascular disease, is to increase cholesterol excretion from the body. Our group and others have recently found that cholesterol excretion can be facilitated by both hepatobiliary and transintestinal pathways. However, the lipoprotein that moves cholesterol through the plasma to the small intestine for transintestinal cholesterol efflux (TICE is unknown. To test the hypothesis that hepatic very low-density lipoproteins (VLDL support TICE, antisense oligonucleotides (ASO were used to knockdown hepatic expression of microsomal triglyceride transfer protein (MTP, which is necessary for VLDL assembly. While maintained on a high cholesterol diet, Niemann-Pick C1-like 1 hepatic transgenic (L1Tg mice, which predominantly excrete cholesterol via TICE, and wild type (WT littermates were treated with control ASO or MTP ASO. In both WT and L1Tg mice, MTP ASO decreased VLDL triglyceride (TG and cholesterol secretion. Regardless of treatment, L1Tg mice had reduced biliary cholesterol compared to WT mice. However, only L1Tg mice treated with MTP ASO had reduced fecal cholesterol excretion. Based upon these findings, we conclude that VLDL or a byproduct such as LDL can move cholesterol from the liver to the small intestine for TICE.

Psycho-social correlates of students' involvement in secret cults and ...

African Journals Online (AJOL)

The study focuses on the premise of incessant havoc being perpetrated by adherents of secret cults in the country's institution of higher learning. These cult groups terrorize fellow students, intimidate members of campus communities in various ways and are often involved in crimes like rape, burglary, thuggery, stealing, ...

Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

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Se Chang Park

2013-01-01

Full Text Available Cyprinid herpes virus 3 (CyHV-3 diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio. Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116 of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116. In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies.

Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

Science.gov (United States)

Han, Jee Eun; Kim, Ji Hyung; Renault, Tristan; Choresca, Casiano; Shin, Sang Phil; Jun, Jin Woo; Park, Se Chang

2013-01-01

Cyprinid herpes virus 3 (CyHV-3) diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio). Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116) of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116). In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies. PMID:23435236

Commercial secret as an instrument of company competitive strategy effectiveness increase

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Peskova Dinara

2017-01-01

Full Text Available Modern companies are very much diversified in scale, sectoral affiliation, marketing behavior. There are many theoretical and applied studies in effective competitiveness strategies (see Porter, M. (2002, 1998, Kramer, M. (1998, Fatkhutdinov, R. A. (2000, Feigelson, V. M. (1996 and others.They present famous approaches and probably there is no need to repeat them in this article. We would like to feature a different concept (suggested by Yudanov A. and followers with terminology adopted from natural sciences and show the way the commercial secret can increase effectiveness of competitiveness strategy. We also perform valid methods of commercial secret protection.

Pituitary-hormone secretion by thyrotropinomas.

Science.gov (United States)

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M; Biermasz, Nienke R; Smit, Jan W; Frolich, Marijke; Keenan, Daniel M; Veldhuis, Johannes D; Romijn, Johannes A

2009-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

Glycoprotein Ibα clustering in platelet storage and function

NARCIS (Netherlands)

Gitz, E.

2013-01-01

Platelets are anucleated, discoid-shaped cells that play an essential role in the formation of a hemostatic plug to prevent blood loss from injured vessels. Initial platelet arrest at the damaged arterial vessel wall is mediated through the interaction between the platelet receptor glycoprotein (GP)