Hormone synthesis and secretion by rat parathyroid glands in tissue culture

PubMed Central

Au, William Y. W.; Poland, Alan P.; Stern, Paula H.; Raisz, Lawrence G.

1970-01-01

Rat parathyroid glands maintained in organ culture secrete biologically active parathyroid hormone (PTH) and synthesize and secrete labeled proteins from 3H- or 14C-labeled amino acids added to the medium. The amounts of biological activity and labeled protein in the medium are both inversely proportional to the calcium concentration. Some of the labeled low molecular weight protein was identified as PTH which had been synthesized and secreted in culture by preliminary isolation on Sephadex G-100 columns and further purification using an antibody to bovine PTH which cross-reacted with rat PTH. The cross-reacting antibody inhibited the biological effects of rat PTH and caused hypocalcemia in intact rats. The antibody bound some of the labeled low molecular weight protein of the medium at neutral pH so that it migrated as a large molecular weight complex on Sephadex. Biologically active, labeled PTH was recovered by dissociation of this complex in acid and rechromatography. PMID:5449703

The secret life of marbled murrelets: monitoring populations and habitats.

Treesearch

Jonathan Thompson

2007-01-01

The marbled murrelet is a small diving seabird that occupies coastal waters from Alaska to central California. Murrelets have a unique nesting strategy that requires them to commute tens of miles inland, where they use large mossy branches on older conifers as platforms to balance their solitary egg. Populations have been declining for decades as the amount of nesting...

NK Depletion Results in Increased CCL22 Secretion and Treg Levels in Lewis Lung Carcinoma via the Accumulation of CCL22-secreting CD11b+CD11c+ Cells

PubMed Central

W., Mailloux, Adam; A., Clark, Anna-Maria; Rita, I. Young, M.

2010-01-01

Tumor induced immune suppression involves the accumulation of suppressive infiltrates in the tumor microenvironment such as regulatory T-cells (Tregs). Previous studies demonstrated that NK-dependant increases in CCL22 secretion selectively recruit Tregs toward murine lungs bearing Lewis Lung Carcinoma (LLC). In order to extend the in vitro studies, the present studies utilized in vivo depletion of NK cells to ascertain the contribution of NK-derived CCL22 toward total CCL22 and subsequent Treg levels in both normal and LLC-bearing lungs. However, NK depletion had the unexpected effect of increasing both CCL22 secretion and Treg levels in the lungs of NK-depleted LLC-bearing mice. This was concurrent with an increase in tumor burden. Flow cytometry and a series of both immunomagnetic and FACS isolations were used to identify the CCL22-producing cellular fractions in LLC-bearing lungs. A novel CD11b+CD11c+ cell population was identified that accumulates in large numbers in NK-depleted LLC-bearing lung tissue. These CD11b+CD11c+ cells secreted large amounts of CCL22 that may overcompensate for the loss of NK-derived CCL22 in the lungs of NK-depleted LLC-bearing mice. Taken together these data suggest that NK cells play both a positive and negative role in the regulation of CCL22 secretion and, in turn, the recruitment of Tregs toward LLC-bearing lungs. PMID:20198623

Induction of polyclonal antibody synthesis by human allogeneic and autologous helper factors

PubMed Central

1979-01-01

Human helper factors were obtained from supernates of 48 h unidirectional allogeneic and autologous mixed lymphocyte reactions. These supernates were shown to induce the production of large amounts of immunoglobulin by tonsillar and peripheral blood mononuclear cells. Abundant polyclonal activation to antibody production occurred in these cultures in the absence of antigenic challenge which was similar in degree to that produced by pokeweed mitogen. This was documented by quantitating plasma cells, specific plaque-forming cells, and secreted immunoglobulin. In addition, the supplementation of companion cultures with sheep erythrocytes resulted in a significant enhancement of the specific plaque-forming cell response without an appreciable change in plasma cell number of secreted Ig. PMID:156242

Unexpected features of exponentially growing Tobacco Bright Yellow-2 cell suspension culture in relation to excreted extracellular polysaccharides and cell wall composition.

PubMed

Issawi, Mohammad; Muhieddine, Mohammad; Girard, Celine; Sol, Vincent; Riou, Catherine

2017-10-01

This article presents a new insight about TBY-2 cells; from extracellular polysaccharides secretion to cell wall composition during cell suspension culture. In the medium of cells taken 2 days after dilution (end of lag phase), a two unit pH decrease from 5.38 to 3.45 was observed and linked to a high uronic acid (UA) amount secretion (47.8%) while, in 4 and 7 day-old spent media, pH increased and UA amounts decreased 35.6 and 42.3% UA, respectively. To attain deeper knowledge of the putative link between extracellular polysaccharide excretion and cell wall composition, we determined cell wall UA and neutral sugar composition of cells from D2 to D12 cultures. While cell walls from D2 and D3 cells contained a large amount of uronic acid (twice as much as the other analysed cell walls), similar amounts of neutral sugar were detected in cells from lag to end of exponential phase cells suggesting an enriched pectin network in young cultures. Indeed, monosaccharide composition analysis leads to an estimated percentage of pectins of 56% for D3 cell wall against 45% D7 cell walls indicating that the cells at the mid-exponential growth phase re-organized their cell wall linked to a decrease in secreted UA that finally led to a stabilization of the spent medium pH to 5.4. In conclusion, TBY-2 cell suspension from lag to stationary phase showed cell wall remodeling that could be of interest in drug interaction and internalization study.

Mucinous (colloid) adenocarcinomas secrete distinct O-acylated forms of sialomucins: a histochemical study of gastric, colorectal and breast adenocarcinomas.

PubMed

Sáez, C; Japón, M A; Poveda, M A; Segura, D I

2001-12-01

Mucinous (colloid) adenocarcinomas represent a distinct group of tumours defined by the presence of large amounts of extracellular mucins. By using histochemical methods, we analysed mucins secreted by mucinous versus non-mucinous adenocarcinomas and looked for differential secretion profiles. Sixty-four adenocarcinomas were studied (23 colorectal, 17 gastric, and 24 breast tumours). Thirty-two tumours were of the colloid type. The following methods were applied to paraffin tissue sections: (i) Alcian blue (pH 2.5) and periodic acid-Schiff (PAS); (ii) high iron diamine and Alcian blue (pH 2.5); (iii) periodic acid borohydride, potassium hydroxide, and PAS; (iv) periodic acid-thionine Schiff, potassium hydroxide, and PAS; and (v) periodic acid-borohydride and PAS. Most adenocarcinomas secreted acidic mucins, with sialomucins predominating over sulfomucins, except for non-mucinous adenocarcinomas of the breast which showed predominant neutral mucins. All mucinous adenocarcinomas contained C9-O-acyl sialic acid as mono, di(C8,C9)-, or tri(C7,C8,C9)-O-acyl forms. Acidic mucins secreted by the majority of non-colloid adenocarcinomas consisted of non-O-acylated sialomucins. C9-O-acylation of sialic acid is a characteristic feature of mucinous adenocarcinomas and can be readily detected by histochemical methods.

Secretion of wound healing mediators by single and bi-layer skin substitutes.

PubMed

Maarof, Manira; Law, Jia Xian; Chowdhury, Shiplu Roy; Khairoji, Khairul Anuar; Saim, Aminuddin Bin; Idrus, Ruszymah Bt Hj

2016-10-01

Limitations of current treatments for skin loss caused by major injuries leads to the use of skin substitutes. It is assumed that secretion of wound healing mediators by these skin substitutes plays a role in treating skin loss. In our previous study, single layer keratinocytes (SK), single layer fibroblast (SF) and bilayer (BL; containing keratinocytes and fibroblasts layers) skin substitutes were fabricated using fibrin that had shown potential to heal wounds in preclinical studies. This study aimed to quantify the secretion of wound healing mediators, and compare between single and bi-layer skin substitutes. Skin samples were digested to harvest fibroblasts and keratinocytes, and expanded to obtain sufficient cells for the construction of skin substitutes. Acellular fibrin (AF) construct was used as control. Substitutes i.e. AF, SK, SF and BL were cultured for 2 days, and culture supernatant was collected to analyze secretion of wound healing mediators via multiplex ELISA. Among 19 wound healing mediators tested, BL substitute secreted significantly higher amounts of CXCL1 and GCSF compared to SF and AF substitute but this was not significant with respect to SK substitute. The BL substitute also secreted significantly higher amounts of CXCL5 and IL-6 compared to other substitutes. In contrast, the SK substitute secreted significantly higher amounts of VCAM-1 compared to other substitutes. However, all three skin substitutes also secreted CCL2, CCL5, CCL11, GM-CSF, IL8, IL-1α, TNF-α, ICAM-1, FGF-β, TGF-β, HGF, VEGF-α and PDGF-BB factors, but no significant difference was seen. Secretion of these mediators after transplantation may play a significant role in promoting wound healing process for the treatment of skin loss.

Jamming dynamics of stretch-induced surfactant release by alveolar type II cells

PubMed Central

Majumdar, Arnab; Arold, Stephen P.; Bartolák-Suki, Erzsébet; Parameswaran, Harikrishnan

2012-01-01

Secretion of pulmonary surfactant by alveolar epithelial type II cells is vital for the reduction of interfacial surface tension, thus preventing lung collapse. To study secretion dynamics, rat alveolar epithelial type II cells were cultured on elastic membranes and cyclically stretched. The amounts of phosphatidylcholine, the primary lipid component of surfactant, inside and outside the cells, were measured using radiolabeled choline. During and immediately after stretch, cells secreted less surfactant than unstretched cells; however, stretched cells secreted significantly more surfactant than unstretched cells after an extended lag period. We developed a model based on the hypothesis that stretching leads to jamming of surfactant traffic escaping the cell, similar to vehicular traffic jams. In the model, stretch increases surfactant transport from the interior to the exterior of the cell. This transport is mediated by a surface layer with a finite capacity due to the limited number of fusion pores through which secretion occurs. When the amount of surfactant in the surface layer approaches this capacity, interference among lamellar bodies carrying surfactant reduces the rate of secretion, effectively creating a jam. When the stretch stops, the jam takes an extended time to clear, and subsequently the amount of secreted surfactant increases. We solved the model analytically and show that its dynamics are consistent with experimental observations, implying that surfactant secretion is a fundamentally nonlinear process with memory representing collective behavior at the level of single cells. Our results thus highlight the importance of a jamming dynamics in stretch-induced cellular secretory processes. PMID:22033531

Enhancing the Biological Relevance of Secretome-Based Proteomics by Linking Tumor Cell Proliferation and Protein Secretion.

PubMed

Gregori, Josep; Méndez, Olga; Katsila, Theodora; Pujals, Mireia; Salvans, Cándida; Villarreal, Laura; Arribas, Joaquin; Tabernero, Josep; Sánchez, Alex; Villanueva, Josep

2014-07-15

Secretome profiling has become a methodology of choice for the identification of tumor biomarkers. We hypothesized that due to the dynamic nature of secretomes cellular perturbations could affect their composition but also change the global amount of protein secreted per cell. We confirmed our hypothesis by measuring the levels of secreted proteins taking into account the amount of proteome produced per cell. Then, we established a correlation between cell proliferation and protein secretion that explained the observed changes in global protein secretion. Next, we implemented a normalization correcting the statistical results of secretome studies by the global protein secretion of cells into a generalized linear model (GLM). The application of the normalization to two biological perturbations on tumor cells resulted in drastic changes in the list of statistically significant proteins. Furthermore, we found that known epithelial-to-mesenchymal transition (EMT) effectors were only statistically significant when the normalization was applied. Therefore, the normalization proposed here increases the sensitivity of statistical tests by increasing the number of true-positives. From an oncology perspective, the correlation between protein secretion and cellular proliferation suggests that slow-growing tumors could have high-protein secretion rates and consequently contribute strongly to tumor paracrine signaling.

Computerised lung sound monitoring to assess effectiveness of chest physiotherapy and secretion removal: a feasibility study.

PubMed

Ntoumenopoulos, G; Glickman, Y

2012-09-01

To explore the feasibility of computerised lung sound monitoring to evaluate secretion removal in intubated and mechanically ventilated adult patients. Before and after observational investigation. Intensive care unit. Fifteen intubated and mechanically ventilated adult patients receiving chest physiotherapy. Chest physiotherapy included combinations of standard closed airway suctioning, saline lavage, postural drainage, chest wall vibrations, manual-assisted cough and/or lung hyperinflation, dependent upon clinical indications. Lung sound amplitude at peak inspiration was assessed using computerised lung sound monitoring. Measurements were performed immediately before and after chest physiotherapy. Data are reported as mean [standard deviation (SD)], mean difference and 95% confidence intervals (CI). Significance testing was not performed due to the small sample size and the exploratory nature of the study. Fifteen patients were included in the study [11 males, four females, mean age 65 (SD 14) years]. The mean total lung sound amplitude at peak inspiration decreased two-fold from 38 (SD 59) units before treatment to 17 (SD 19) units after treatment (mean difference 22, 95% CI of difference -3 to 46). The mean total lung sound amplitude from the lungs of patients with a large amount of secretions (n=9) was over four times 'louder' than the lungs of patients with a moderate or small amount of secretions (n=6) [56 (SD 72) units vs 12 (13) units, respectively; mean difference -44, 95% CI of difference -100 to 11]. The mean total lung sound amplitude decreased in the group of 'loud' right and left lungs (n=15) from 37 (SD 36) units before treatment to 15 (SD 13) units after treatment (mean difference 22, 95% CI of difference 6 to 38). Computerised lung sound monitoring in this small group of patients demonstrated a two-fold decrease in lung sound amplitude following chest physiotherapy. Subgroup analysis also demonstrated decreasing trends in lung sound amplitude in the group of 'loud' lungs following chest physiotherapy. Due to the small sample size and large SDs with high variability in the lung sound amplitude measurements, significance testing was not reported. Further investigation is needed in a larger sample of patients with more accurate measurement of sputum wet weight in order to distinguish between secretion-related effects and changes due to other factors such as airflow rate and pattern. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Jejunal and ileal absorption of oxprenolol in man: influence of nutrients and digestive secretions on jejunal absorption and systemic availability.

PubMed Central

Godbillon, J; Vidon, N; Palma, R; Pfeiffer, A; Franchisseur, C; Bovet, M; Gosset, G; Bernier, J J; Hirtz, J

1987-01-01

1 Study I evaluated the absorption of oxprenolol in the ileum, compared to jejunum, in healthy volunteers by an intestinal perfusion technique. Around 80 mg of drug were delivered as a saline solution directly in the small bowel. 2 Samples taken 30 cm distally to the site of perfusion showed that 63% of perfused oxprenolol was absorbed in the jejunum and 48% in the ileum; the differences were significant. 3 The plasma concentration-time profiles were similar for the two perfusions. The AUC and Cmax values of free and conjugated oxprenolol for the jejunal perfusion were significantly lower than those of ileum. They showed large but consistent intersubject variations in the two treatments. 4 Study II investigated, using the same technique, the influence of nutrients and digestive secretions on jejunal absorption and systemic availability of this drug. A saline (in treatments A and B) or a nutrient (in treatment C) solution containing oxprenolol was perfused into the jejunum below a balloon either inflated (A) or deflated (B and C). 5 The disappearance rate of oxprenolol from the jejunum was unaffected by endogenous secretions. The mean amount of drug absorbed along a 30-cm jejunal segment accounted for 52 (A) and 57% (B) of the total amount perfused. The intestinal absorption rate was markedly increased in the presence of nutrients (mean amount absorbed 96% for C). 6 The change in the rate of disappearance from the intestine had no effect on the systemic availability of oxprenolol (mean AUC values 8740, 8250 and 8020 nmol l-1 h for A, B and C, respectively) or its elimination from plasma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3663450

Permeability of oral tissues to blood-borne coxsackievirus B-1.

PubMed

Madonia, J V; Bahn, A N

1967-03-01

The ability of coxsackievirus B-1 to pass the barriers of the circulatory system into whole saliva has been shown previously. In this investigation, the major salivary glands and the oral mucosa were studied, and their role as participants in the excretion of coxsackievirus B-1 during viremia was evaluated. The effect of the salivary-gland stimulant pilocarpine nitrate on both the salivary flow rate and the recovery of virus during viremia was determined. A comparison was made between the amount of virus recovered from whole saliva during viremia in animals deficient in one or both of the major salivary-gland pairs and animals with a complete complement of salivary glands. The salivary glands in other animals were cannulated, and pure glandular secretions were collected during viremia and assayed for the presence of virus The amount of virus passing from the capillaries of the oral mucosa to the surface was also determined to evaluate this route as a possible site for the excretion of virus into saliva during viremia. The major salivary glands did not excrete appreciable quantities of virus during viremia. The submaxillary-gland secretions did not contain virus, and the parotid-gland secretions showed virus only at extremely high blood virus levels. Either removal of the major salivary glands or decreased salivary flow rates increased the concentration of virus in whole saliva. This observation suggested that the production of saliva by the major salivary glands tends to dilute the virus in the oral cavity. A 0.88-cm(2) sample of the oral mucosa excreted significantly large amounts of virus during viremia and suggested that the passage of virus through the oral mucosa was the major route for the excretion of virus into saliva during viremia.

Covert Channels within IRC

DTIC Science & Technology

2011-03-24

in the secret file in bits. Therefore, CPP is a function of the size of the secret file and amount of covert information embedded per packet, while...CPS is dependent on the size of the secret file and the rate at which the covert packets are transmitted to the IRC server. • Build a covert...and decode a secret message. • Cover. The object being used to hide the secret information; this is often in the form of pictures [FPK07], audio

Noncoordinate expression of J-chain and Blimp-1 define nurse shark plasma cell populations during ontogeny.

PubMed

Castro, Caitlin D; Ohta, Yuko; Dooley, Helen; Flajnik, Martin F

2013-11-01

B-lymphocyte-induced maturation protein 1 (Blimp-1) is the master regulator of plasma cell development, controlling genes such as those encoding J-chain and secretory Ig heavy chain. However, some mammalian plasma cells do not express J-chain, and mammalian B1 cells secrete "natural" IgM antibodies without upregulating Blimp-1. While these results have been controversial in mammalian systems, here we describe subsets of normally occurring Blimp-1(-) antibody-secreting cells in nurse sharks, found in lymphoid tissues at all ontogenic stages. Sharks naturally produce large amounts of both pentameric (classically "19S") and monomeric (classically "7S") IgM, the latter an indicator of adaptive immunity. Consistent with the mammalian paradigm, shark Blimp-1 is expressed in splenic 7S IgM-secreting cells, though rarely detected in the J-chain(+) cells producing 19S IgM. Although IgM transcript levels are lower in J-chain(+) cells, these cells nevertheless secrete 19S IgM in the absence of Blimp-1, as demonstrated by ELISPOT and metabolic labeling. Additionally, cells in the shark BM equivalent (epigonal) are Blimp-1(-). Our data suggest that, in sharks, 19S-secreting cells and other secreting memory B cells in the epigonal are maintained for long periods without Blimp-1, but like in mammals, Blimp-1 is required for terminating the B-cell program following an adaptive immune response in the spleen. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Non-coordinate expression of J-chain and Blimp-1 define nurse shark plasma cell populations during ontogeny

PubMed Central

Castro, Caitlin D.; Ohta, Yuko; Dooley, Helen; Flajnik, Martin F.

2014-01-01

Summary Blimp-1 is the master regulator of plasma cell development, controlling genes such as J-chain and secretory Ig heavy chain. However, some mammalian plasma cells do not express J-chain, and mammalian B1 cells secrete “natural” IgM antibodies without upregulating Blimp-1. While these results have been controversial in mammalian systems, here we describe subsets of normally occurring Blimp-1- antibody secreting cells in nurse sharks, found in lymphoid tissues at all ontogenic stages. Sharks naturally produce large amounts of both pentameric (classically ‘19S’) and monomeric (classically ‘7S’) IgM, the latter an indicator of adaptive immunity. Consistent with the mammalian paradigm, shark Blimp-1 is expressed in splenic 7S IgM-secreting cells, though rarely detected in the J-chain+ cells producing 19S IgM. Although IgM transcript levels are lower in J-chain+ cells, these cells nevertheless secrete 19S IgM in the absence of Blimp-1, as demonstrated by ELISPOT and metabolic labeling. Additionally, cells in the shark bone marrow equivalent (epigonal) are Blimp-1-. Our data suggest that, in sharks, 19S-secreting cells and other secreting memory B cells in the epigonal can be maintained for long periods without Blimp-1, but like in mammals, Blimp-1 is required for terminating the B cell program following an adaptive immune response in the spleen. PMID:23897025

A broad diversity of volatile carboxylic acids, released by a bacterial aminoacylase from axilla secretions, as candidate molecules for the determination of human-body odor type.

PubMed

Natsch, Andreas; Derrer, Samuel; Flachsmann, Felix; Schmid, Joachim

2006-01-01

Human body odor is to a large part determined by secretions of glands in the axillary regions. Two key odoriferous principles, 3-methylhex-2-enoic acid (3MH2; 4/5) and 3-hydroxy-3-methylhexanoic acid (HMHA; 6) have been shown to be released from glutamine conjugates secreted in the axilla by a specific N(alpha)-acyl-glutamine aminoacylase (N-AGA) obtained from axilla isolates of Corynebacteria sp. However, the low number of different odorants reported in humans stands in contrast to the observed high inter-individual variability in body odors. Axilla secretions of individual donors were, therefore, analyzed in detail. The secretions were treated with N-AGA, analyzed by GC/MS, and compared to undigested controls. Over 28 different carboxylic acids were released by this enzyme from odorless axilla secretions (Table 1). Many of these body odorants have not been reported before from a natural source, and they include several aliphatic 3-hydroxy acids with 4-Me branches, 3,4-unsaturated, 4-Et-branched aliphatic acids, and a variety of degradation products of amino acids. The odor threshold of some of the acids was found to be in the range of 1 ng. Most of these compounds were present in all donors tested, but in highly variable relative amounts, and they are, thus, candidate molecules as key components of a 'compound odor' determining the individual types of human body odor.

Low cost of gastric acid secretion during digestion in ball pythons.

PubMed

Nørgaard, Simon; Andreassen, Kim; Malte, Christian Lind; Enok, Sanne; Wang, Tobias

2016-04-01

Due to their large metabolic responses to digestion (specific dynamic action, SDA), snakes represent an interesting animal group to identify the underlying mechanisms for the postprandial rise in metabolism. The SDA response results from the energetic costs of many different processes ranging over prey handling, secretions by the digestive system, synthesis of enzymes, plasticity of most visceral organs, as well as protein synthesis and nitrogen excretion. The contribution of the individual mechanisms, however, remains elusive. Gastric acid secretion has been proposed to account for more than half of the SDA response, while other studies report much lower contributions of the gastric processes. To investigate the energetic cost of gastric acid secretion, ball pythons (Python regius) were fed meals with added amounts of bone meal (up to 25 g bone meal kg(-1) snake) to achieve a five-fold rise in the buffer capacity of the meals. Direct measurements within the stomach lumen showed similar reduction in gastric pH when buffer capacity was increased, but we found no effects on the rise in oxygen consumption over the first three days of digestion. There was, however, a slower return of oxygen consumption to resting baseline. We conclude that gastric acid secretion only contributes modestly to the SDA response and propose that post-absorptive processes, such as increased protein synthesis, are likely to underlie the SDA response. Copyright © 2016 Elsevier Inc. All rights reserved.

Dermal glands in freshwater mites Limnesia undulata (O.F. Müller, 1776) and Limnesia fulgida (C.L. Koch, 1836) (Acariformes, Limnesiidae).

PubMed

Shatrov, Andrew B; Soldatenko, Elena V

2016-07-01

Dermal glands in the water mites Limnesia undulata (O.F. Müller, 1776) and Limnesia fulgida (C.L. Koch, 1836) and their secretion were studied by means of light microscopical, transmission electron microscopical (TEM) and scanning electron microscopical (SEM) methods. These mites possess two types of dermal glands - the 'common' dermal glands in a number of 14 pairs and one pair of the so-called 'idiosomal' dermal glands. The common dermal glands are bi-lobed organs and consist of high prismatic secretory cells directed to the gland mouth and mostly replacing the intra-alveolar lumen. The cells contain numerous cisterns of rough endoplasmic reticulum (RER) and specifically organized Golgi bodies (GB) producing electron-dense elongated secretory granules. These granules are released from the cells via apocrine secretion and come to the gland mouth, where they are sometimes accompanied by secretory cell cytoplasm. The final secretion may show a fibrous character. The idiosomal glands are sac-like organs stretched along the ventral body wall in posterior direction from the gland orifice corresponding to the epimeroglandularia 4. The secretory epithelium leaves a large intra-alveolar lumen filled with an electron-dense secretory material. Golgi bodies are organized identically with those in the common glands, which indicates the general homology of these two types of dermal glands. The glands' orifices are organized similarly in all glands and possess an internal funnel-shaped sclerite with muscle armament, an internal valve, medial epicuticular flaps and an external circular cuticular ring. All glandularia, except for E4 and V1, are accompanied with a long and thin sensitive seta. During fixation, secretion of the common dermal glands is extruded to the exterior in the form of large amounts of convoluted tube-like structures. In the living organisms, being secreted in mass from the glands, this secretion acquires the form of long rigid mostly hollow un-branched threads comparable with the similar silken threads of other water arthropods. The function of the idiosomal glands secretion still remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diadenosine tetraphosphate contributes to carbachol-induced tear secretion.

PubMed

Fonseca, Begoña; Martínez-Águila, Alejandro; Díaz-Hernández, Miguel; Pintor, Jesús

2015-03-01

The purpose of this study is to investigate if the cholinergic stimulation by carbachol on tear secretion is a direct process or if it is also mediated by purinergic mechanisms. Experiments were performed in New Zealand male rabbits. The amount of tear secretion was measured with Schirmer's test and then analyzed by a HPLC protocol in order to study the nucleotide levels. Animal eyes were instilled with carbachol (a cholinergic agonist), pirenzepine, gallamine and 4-DAMP (muscarinic antagonists), PPADS, suramin and reactive blue 2 (purinergic antagonists), and a P2Y2 receptor small interfering RNA (siRNA). Tear secretion increased with the instillation of carbachol, approximately 84 % over control values 20 min after the instillation and so did Ap4A and ATP release. When we applied carbachol in the presence of muscarinic antagonists, tear volume only increased to 4 % with atropine, 12 % in the case of pirenzepine, 3 % with gallamine, and 8 % with 4-DAMP. In the presence of carbachol and purinergic antagonists, tear secretion was increased to 12 % (all values compared to basal tear secretion). By analyzing tear secretion induced with carbachol in presence of a P2Y2 receptor siRNA, we found that tear secretion was diminished to 60 %. The inhibition of tear secretion in the presence of carbachol and purinergic antagonists or P2Y2 siRNA occurred with no apparent change in the tear amount of Ap4A. These experiments demonstrated the participation of Ap4A in lacrimal secretion process.

The Daily Consumption of Cola Can Determine Hypocalcemia: A Case Report of Postsurgical Hypoparathyroidism-Related Hypocalcemia Refractory to Supplemental Therapy with High Doses of Oral Calcium.

PubMed

Guarnotta, Valentina; Riela, Serena; Massaro, Marina; Bonventre, Sebastiano; Inviati, Angela; Ciresi, Alessandro; Pizzolanti, Giuseppe; Benvenga, Salvatore; Giordano, Carla

2017-01-01

The consumption of soft drinks is a crucial factor in determining persistent hypocalcemia. The aim of the study is to evaluate the biochemical mechanisms inducing hypocalcemia in a female patient with usual high consumption of cola drink and persistent hypocalcemia, who failed to respond to high doses of calcium and calcitriol supplementation. At baseline and after pentagastrin injection, gastric secretion (Gs) and duodenal secretion (Ds) samples were collected and calcium and total phosphorus (P tot ) concentrations were evaluated. At the same time, blood calcium, P tot , sodium, potassium, chloride, magnesium concentrations, and vitamin D were sampled. After intake of cola (1 L) over 180 min, Gs and Ds and blood were collected and characterized in order to analyze the amount of calcium and P tot or sodium, potassium, magnesium, and chloride ions, respectively. A strong pH decrease was observed after cola intake with an increase in phosphorus concentration. Consequently, a decrease in calcium concentration in Gs and Ds was observed. A decrease in calcium concentration was also observed in blood. In conclusion, we confirm that in patients with postsurgical hypoparathyroidism, the intake of large amounts of cola containing high amounts of phosphoric acid reduces calcium absorption efficiency despite the high doses of calcium therapy.

Interleukins 1alpha and 1beta secreted by some melanoma cell lines strongly reduce expression of MITF-M and melanocyte differentiation antigens.

PubMed

Kholmanskikh, Olga; van Baren, Nicolas; Brasseur, Francis; Ottaviani, Sabrina; Vanacker, Julie; Arts, Nathalie; van der Bruggen, Pierre; Coulie, Pierre; De Plaen, Etienne

2010-10-01

We report that melanoma cell lines expressing the interleukin-1 receptor exhibit 4- to 10-fold lower levels of mRNA of microphthalmia-associated transcription factor (MITF-M) when treated with interleukin-1beta. This effect is NF-kappaB and JNK-dependent. MITF-M regulates the expression of melanocyte differentiation genes such as MLANA, tyrosinase and gp100, which encode antigens recognized on melanoma cells by autologous cytolytic T lymphocytes. Accordingly, treating some melanoma cells with IL-1beta reduced by 40-100% their ability to activate such antimelanoma cytolytic T lymphocytes. Finally, we observed large amounts of biologically active IL-1alpha or IL-1beta secreted by two melanoma cell lines that did not express MITF-M, suggesting an autocrine MITF-M downregulation. We estimate that approximately 13% of melanoma cell lines are MITF-M-negative and secrete IL-1 cytokines. These results indicate that the repression of melanocyte-differentiation genes by IL-1 produced by stromal cells or by tumor cells themselves may represent an additional mechanism of melanoma immune escape.

Odor of the muskox : A preliminary investigation.

PubMed

Flood, P F; Abrams, S R; Muir, G D; Rowell, J E

1989-08-01

The behavior of captive male muskoxen was observed closely during their characteristic superiority display, the anatomy of the preputial region was studied in two adults and three calves, and preputial washings and preorbital gland secretion were subjected to gas chromatography and mass spectroscopy. During the superiority display, the prepuce was everted to form a pendulous tube tipped with a fringe of matted hair. Owing to the movement of the animal, the urine that dribbled from the preputial opening was liberally applied to the long guard hairs of the belly. The superiority display was almost exclusively confined to dominant males and apparently accounted for their odor. In the quiescent state, the hair seen around the preputial opening was drawn inside and formed an 8 cm-wide band on the lining of the prepuce. The preputial washings contained large amounts of benzoic acid andp-cresol. The infraorbital gland secretion contained cholesterol, benzaldehyde, and a homologous series of saturated γ-lactones ranging from 8 to 12 carbons. The latter compounds and the natural secretion smell similar to the human nose.

Remediation of lead-contaminated water by geological fluorapatite and fungus Penicillium oxalicum.

PubMed

Tian, Da; Wang, Wenchao; Su, Mu; Zheng, Junyi; Wu, Yuanyi; Wang, Shimei; Li, Zhen; Hu, Shuijin

2018-05-16

Phosphate-solubilizing fungi (PSF) can secrete large amounts of organic acids. In this study, the application of the fungus Penicillium oxalicum and geological fluorapatite (FAp) to lead immobilization was investigated. The formation and morphology of the lead-related minerals were analyzed by ATR-IR, XRD, Raman, and SEM. The quantity of organic acids secreted by P. oxalicum reached the maximum on the fourth day, which elevated soluble P concentrations from 0.4 to 108 mg/L in water. The secreted oxalic acid dominates the acidity in solution. P. oxalicum can survive in the solution with Pb concentration of ~ 1700 mg/L. In addition, it was shown that ~ 98% lead cations were removed while the fungus was cultured with Pb (~ 1700 mg/L) and FAp. The mechanism is that the released P from FAp (enhanced by organic acids) can react with Pb 2+ to form the stable pyromorphite mineral [Pb 5 (PO 4 ) 3 F]. The precipitation of lead oxalate also contributes to Pb immobilization. However, lead oxalate is more soluble due to its relatively high solubility. P. oxalicum has a higher rate of organic acid secretion compared with other typical PSF, e.g., Aspergillus niger. This study sheds light on bright future of applying P. oxalicum in Pb remediation.

Stable expression of the hepatitis B virus surface antigen containing pre-S2 protein in mouse cells using a bovine papillomavirus vector.

PubMed

Yoneyama, T; Akatsuka, T; Miyamura, T

1988-08-01

The large BglII fragment (2.8 kilobases) of hepatitis B virus DNA including the transcription unit for the hepatitis B surface antigen (HBsAg) was inserted into a bovine papillomavirus vector containing the neomycin resistance gene. The recombinant DNA was transfected into mouse C127 cells. A stable transformed cell line (MS128) secreting a large amount of 22 nm HBsAg particles containing pre-S2 protein was established. The secreted HBsAg particles had the receptor for polymerized human serum albumin. Immunoprecipitation and Western blot analyses showed that HBsAg particles consisted of two major proteins of 22K and 26K encoded by the S gene and a minor protein of 35K encoded by the pre-S2 and S genes. Southern blot analysis revealed that the transfected plasmid was integrated into the host chromosomal DNA and that most of the plasmid sequences were present. These results suggest that the stable expression of the HBsAg in MS128 cells is related to the integrated state of the recombinant DNA.

Sugary secretions of wasp galls: a want-to-be extrafloral nectar?

PubMed

Aranda-Rickert, Adriana; Rothen, Carolina; Diez, Patricia; González, Ana María; Marazzi, Brigitte

2017-11-10

The most widespread form of protective mutualisms is represented by plants bearing extrafloral nectaries (EFNs) that attract ants and other arthropods for indirect defence. Another, but less common, form of sugary secretion for indirect defence occurs in galls induced by cynipid wasps. Until now, such galls have been reported only for cynipid wasps that infest oak trees in the northern hemisphere. This study provides the first evidence of galls that exude sugary secretions in the southern hemisphere and asks whether they can be considered as analogues of plants' EFNs. The ecology and anatomy of galls and the chemical composition of the secretion were investigated in north-western Argentina, in natural populations of the host trees Prosopis chilensis and P. flexuosa . To examine whether ants protect the galls from natural enemies, ant exclusion experiments were conducted in the field. The galls produce large amounts of sucrose-rich, nectar-like secretions. No typical nectary and sub-nectary parenchymatic tissues or secretory trichomes can be observed; instead there is a dense vascularization with phloem elements reaching the gall periphery. At least six species of ants, but also vespid wasps, Diptera and Coleoptera, consumed the gall secretions. The ant exclusion experiment showed that when ants tended galls, no differences were found in the rate of successful emergence of gall wasps or in the rate of parasitism and inquiline infestation compared with ant-excluded galls. The gall sugary secretion is not analogous to extrafloral nectar because no nectar-producing structure is associated with it, but is functionally equivalent to arthropod honeydew because it provides indirect defence to the plant parasite. As in other facultative mutualisms mediated by sugary secretions, the gall secretion triggers a complex multispecies interaction, in which the outcome of individual pair-wise interactions depends on the ecological context in which they take place. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Expression analysis and identification of antimicrobial peptide transcripts from six North American frog species

USGS Publications Warehouse

Robertson, Laura S.; Fellers, Gary M.; Marranca, Jamie Marie; Kleeman, Patrick M.

2013-01-01

Frogs secrete antimicrobial peptides onto their skin. We describe an assay to preserve and analyze antimicrobial peptide transcripts from field-collected skin secretions that will complement existing methods for peptide analysis. We collected skin secretions from 4 North American species in the field in California and 2 species in the laboratory. Most frogs appeared healthy after release; however, Rana boylii in the Sierra Nevada foothills, but not the Coast Range, showed signs of morbidity and 2 died after handling. The amount of total RNA extracted from skin secretions was higher in R. boylii and R. sierrae compared to R. draytonii, and much higher compared to Pseudacris regilla. Interspecies variation in amount of RNA extracted was not explained by size, but for P. regilla it depended upon collection site and date. RNA extracted from skin secretions from frogs handled with bare hands had poor quality compared to frogs handled with gloves or plastic bags. Thirty-four putative antimicrobial peptide precursor transcripts were identified. This study demonstrates that RNA extracted from skin secretions collected in the field is of high quality suitable for use in sequencing or quantitative PCR (qPCR). However, some species do not secrete profusely, resulting in very little extracted RNA. The ability to measure transcript abundance of antimicrobial peptides in field-collected skin secretions complements proteomic analyses and may provide insight into transcriptional mechanisms that could affect peptide abundance.

Insulin and glucose sensitivity, insulin secretion and beta-cell distribution in endocrine pancreas of the fruit bat Artibeus lituratus.

PubMed

Protzek, A O P; Rafacho, A; Viscelli, B A; Bosqueiro, J R; Cappelli, A P; Paula, F M M; Boschero, A C; Pinheiro, E C

2010-10-01

The fruit bat Artibeus lituratus absorbs large amounts of glucose in short periods of time and maintains normoglycemia even after a prolonged starvation period. Based on these data, we aimed to investigate various aspects related with glucose homeostasis analyzing: blood glucose and insulin levels, intraperitoneal glucose and insulin tolerance tests (ipGTT and ipITT), glucose-stimulated insulin secretion (2.8, 5.6 or 8.3 mmol/L glucose) in pancreas fragments, cellular distribution of beta cells, and the amount of pAkt/Akt in the pectoral muscle and liver. Blood glucose levels were higher in fed bats (6.88+/-0.5 mmol/L) than fasted bats (4.0+/-0.8 mmol/L), whereas insulin levels were similar in both conditions. The values of the area-under-the curve obtained from ipGTT were significantly higher when bats received 2 (5.5-fold) or 3g/kg glucose (7.5-fold) b.w compared to control (saline). These bats also exhibited a significant decrease of blood glucose values after insulin administration during the ipITT. Insulin secretion from fragments of pancreas under physiological concentrations of glucose (5.6 or 8.3 mmol/L) was similar but higher than in 2.8 mmol/L glucose 1.8- and 2.0-fold, respectively. These bats showed a marked beta-cell distribution along the pancreas, and the pancreatic beta cells are not exclusively located at the central part of the islet. The insulin-induced Akt phosphorylation was more pronounced in the pectoral muscle, compared to liver. The high sensitivity to glucose and insulin, the proper insulin response to glucose, and the presence of an apparent large beta-cell population could represent benefits for the management of high influx of glucose from a carbohydrate-rich meal, which permits appropriate glucose utilization. 2010 Elsevier Inc. All rights reserved.

National Special Security Events

DTIC Science & Technology

2009-03-24

issue Congress may wish to address. In FY2008, Congress appropriated $1 million for NSSE costs within the Secret Service.18 Some might argue that the...as the recent presidential inauguration. The amount appropriated could be additionally problematic considering that the Secret Service is not...authorized to reimburse state and local law enforcement entities’ overtime costs associated with NSSEs. Any security costs incurred by the Secret Service

Bile Formation and Secretion

PubMed Central

Boyer, James L.

2014-01-01

Bile is a unique and vital aqueous secretion of the liver that is formed by the hepatocyte and modified down stream by absorptive and secretory properties of the bile duct epithelium. Approximately 5% of bile consists of organic and inorganic solutes of considerable complexity. The bile-secretory unit consists of a canalicular network which is formed by the apical membrane of adjacent hepatocytes and sealed by tight junctions. The bile canaliculi (~1 μm in diameter) conduct the flow of bile countercurrent to the direction of portal blood flow and connect with the canal of Hering and bile ducts which progressively increase in diameter and complexity prior to the entry of bile into the gallbladder, common bile duct, and intestine. Canalicular bile secretion is determined by both bile salt-dependent and independent transport systems which are localized at the apical membrane of the hepatocyte and largely consist of a series of adenosine triphosphate-binding cassette transport proteins that function as export pumps for bile salts and other organic solutes. These transporters create osmotic gradients within the bile canalicular lumen that provide the driving force for movement of fluid into the lumen via aquaporins. Species vary with respect to the relative amounts of bile salt-dependent and independent canalicular flow and cholangiocyte secretion which is highly regulated by hormones, second messengers, and signal transduction pathways. Most determinants of bile secretion are now characterized at the molecular level in animal models and in man. Genetic mutations serve to illuminate many of their functions. PMID:23897680

Homogeneity and heterogeneity in amylase production by Bacillus subtilis under different growth conditions.

PubMed

Ploss, Tina N; Reilman, Ewoud; Monteferrante, Carmine G; Denham, Emma L; Piersma, Sjouke; Lingner, Anja; Vehmaanperä, Jari; Lorenz, Patrick; van Dijl, Jan Maarten

2016-03-29

Bacillus subtilis is an important cell factory for the biotechnological industry due to its ability to secrete commercially relevant proteins in large amounts directly into the growth medium. However, hyper-secretion of proteins, such as α-amylases, leads to induction of the secretion stress-responsive CssR-CssS regulatory system, resulting in up-regulation of the HtrA and HtrB proteases. These proteases degrade misfolded proteins secreted via the Sec pathway, resulting in a loss of product. The aim of this study was to investigate the secretion stress response in B. subtilis 168 cells overproducing the industrially relevant α-amylase AmyM from Geobacillus stearothermophilus, which was expressed from the strong promoter P(amyQ)-M. Here we show that activity of the htrB promoter as induced by overproduction of AmyM was "noisy", which is indicative for heterogeneous activation of the secretion stress pathway. Plasmids were constructed to allow real-time analysis of P(amyQ)-M promoter activity and AmyM production by, respectively, transcriptional and out-of-frame translationally coupled fusions with gfpmut3. Our results show the emergence of distinct sub-populations of high- and low-level AmyM-producing cells, reflecting heterogeneity in the activity of P(amyQ)-M. This most likely explains the heterogeneous secretion stress response. Importantly, more homogenous cell populations with regard to P(amyQ)-M activity were observed for the B. subtilis mutant strain 168degUhy32, and the wild-type strain 168 under optimized growth conditions. Expression heterogeneity of secretory proteins in B. subtilis can be suppressed by degU mutation and optimized growth conditions. Further, the out-of-frame translational fusion of a gene for a secreted target protein and gfp represents a versatile tool for real-time monitoring of protein production and opens novel avenues for Bacillus production strain improvement.

Host Immune Selection of Rumen Bacteria through Salivary Secretory IgA

PubMed Central

Fouhse, Janelle M.; Smiegielski, Luke; Tuplin, Melanie; Guan, Le Luo; Willing, Benjamin P.

2017-01-01

The rumen microbiome is integral to efficient production in cattle and shows strong host specificity, yet little is known about what host factors shape rumen microbial composition. Secretory immunoglobulin A (SIgA) is produced in large amounts in the saliva, can coat both commensal and pathogenic microbes within the gut, and presents a plausible mechanism of host specificity. However, the role salivary SIgA plays in commensal bacteria selection in ruminants remains elusive. The main objectives of this study were to develop an immuno-affinity benchtop method to isolate SIgA-tagged microbiota and to determine if salivary SIgA preferentially binds selected bacteria. We hypothesized that SIgA-tagged bacteria would differ from total bacteria, thus supporting a potential host-derived mechanism in commensal bacterial selection. Whole rumen (n = 9) and oral secretion samples (n = 10) were incubated with magnetic beads conjugated with anti-secretory IgA antibodies to enrich SIgA-tagged microbiota. Microbial DNA from the oral secretion, whole rumen, SIgA-tagged oral secretion, and SIgA-tagged rumen was isolated for amplicon sequencing of V1–V3 region of 16S rDNA genes. Whole rumen and oral secretion had distinctive (P < 0.05) bacterial compositions indicated by the non-parametric multidimensional scaling plot using Euclidean distance metrics. The SIgA-tagged microbiota from rumen and oral secretion had similar abundance of Bacteroidetes, Actinobacteria, Fibrobacter, candidate phyla TM7, and Tenericutes and are clustered tightly. Composition of SIgA-tagged oral secretion microbiota was more similar to whole rumen microbiota than whole oral secretion due to enrichment of rumen bacteria (Lachnospiraceae) and depletion of oral taxa (Streptococcus, Rothia, Neisseriaceae, and Lactobacillales). In conclusion, SIgA-tagged oral secretion microbiota had an increased resemblance to whole rumen microbiota, suggesting salivary SIgA-coating may be one host-derived mechanism impacting commensal colonization. Further studies, to explore the variations in antibody affinity between different animals as a driver of microbial composition are warranted. PMID:28553275

Parasympathetic control of airway submucosal glands: central reflexes and the airway intrinsic nervous system.

PubMed

Wine, Jeffrey J

2007-04-30

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences of this for gland secretion and airway defense are poorly understood, but it is possible that interventions to modify submucosal gland secretion in transplanted lungs might have therapeutic consequences.

Mechanical Verification of Cryptographic Protocols

NASA Astrophysics Data System (ADS)

Cheng, Xiaochun; Ma, Xiaoqi; Huang, Scott C.-H.; Cheng, Maggie

Information security is playing an increasingly important role in modern society, driven especially by the uptake of the Internet for information transfer. Large amount of information is transmitted everyday through the Internet, which is often the target of malicious attacks. In certain areas, this issue is vital. For example, military departments of governments often transmit a great amount of top-secret data, which, if divulged, could become a huge threat to the public and to national security. Even in our daily life, it is also necessary to protect information. Consider e-commerce systems as an example. No one is willing to purchase anything over the Internet before being assured that all their personal and financial information will always be kept secure and will never be leaked to any unauthorised person or organisation.

Relationship between naturally occurring human mucosal and serum antibody to the capsular polysaccharide of Haemophilus influenzae type b.

PubMed

Pichichero, M E; Insel, R A

1982-08-01

The prevalence of natural mucosal antibody to the capsular polysaccharide (polyribosylribitolphosphate [PRP]) of Haemophilus influenzae type b in adults at multiple secretory sites and the relationship between natural serum and mucosal antibodies with respect to their amount and fine binding specificity were examined. All of 16 lactating women had antibody to PRP in serum and mammary samples; 11 of 14 studied had nasal antibody and 12 of 14 had salivary antibody. The amount of serum antibody to PRP in an individual positively correlated with the amount of mucosal antibody at each of the three secretory sites examined, and the antibody amount between certain secretions were also positively correlated. Antibody to PRP that is cross-reactive with Escherichia coli K100 or Streptococcus pneumoniae type 6 capsular polysaccharides was detected in the secretions of seven and one subjects, respectively, but the amount was not correlated with serum cross-reactive antibody.

Cross-talk between adipose and gastric leptins for the control of food intake and energy metabolism.

PubMed

Cammisotto, Philippe G; Levy, Emile; Bukowiecki, Ludwik J; Bendayan, Moise

2010-09-01

The understanding of the regulation of food intake has become increasingly complex. More than 20 hormones, both orexigenic and anorexigenic, have been identified. After crossing the blood-brain barrier, they reach their main site of action located in several hypothalamic areas and interact to balance satiety and hunger. One of the most significant advances in this matter has been the discovery of leptin. This hormone plays fundamental roles in the control of appetite and in regulating energy expenditure. In accordance with the lipostatic theory stated by Kennedy in 1953, leptin was originally discovered in white adipose tissue. Its expression by other tissues was later established. Among them, the gastric mucosa has been shown to secrete large amounts of leptin. Both the adipose and the gastric tissues share similar characteristics in the synthesis and storage of leptin in granules, in the formation of a complex with the soluble receptor and a secretion modulated by hormones and energy substrates. However while adipose tissue secretes leptin in a slow constitutive endocrine way, the gastric mucosa releases leptin in a rapid regulated exocrine fashion into the gastric juice. Exocrine-secreted leptin survives the extreme hydrolytic conditions of the gastric juice and reach the duodenal lumen in an intact active form. Scrutiny into transport mechanisms revealed that a significant amount of the exocrine leptin crosses the intestinal wall by active transcytosis. Leptin receptors, expressed on the luminal and basal membrane of intestinal epithelial cells, are involved in the control of nutrient absorption by enterocytes, mucus secretion by goblet cells and motility, among other processes, and this control is indeed different depending upon luminal or basal stimulus. Gastric leptin after transcytosis reaches the central nervous system, to control food intake. Studies using the Caco-2, the human intestinal cell line, in vitro allowed analysis of the mechanisms of leptin actions on the intestinal mucosa, identification of the mechanisms of leptin transcytosis and understanding the modulation of leptin receptors by nutrients and hormones. Exocrine-secreted gastric leptin thus participates in a physiological axis independent in terms of time and regulation from that of adipose tissue to rapidly control food intake and nutrient absorption. Adipocytes and gastric epithelial cells are two cell types the metabolism of which is closely linked to food intake and energy storage. The coordinated secretion of adipose and gastric leptins ensures proper management of food processing and energy storage. Copyright (c) 2010 Elsevier GmbH. All rights reserved.

Exposure to cigarette smoke disturbs adipokines secretion causing intercellular damage and insulin resistance in high fructose diet-induced metabolic disorder mice.

PubMed

Kim, Sanghwa; Lee, Ah Young; Kim, Hyeon-Jeong; Hong, Seong-Ho; Go, Ryeo-Eun; Choi, Kyung-Chul; Kang, Kyung-Sun; Cho, Myung-Haing

2017-12-16

A large amount of fructose intake along with smoking is associated with increased incidence of diseases linked to metabolic syndrome. More research is necessary to understand the complex mechanism that ultimately results in metabolic syndrome and the effect, if any, of high fructose dietary intake and smoking on individual health. In this study, we investigated changes in ER-Golgi network and disturbance to secretion of adipokines induced by cigarette smoking (CS) and excess fructose intake and their contribution to the disruption of metabolic homeostasis. We used high fructose-induced metabolic disorder mice model by feeding them with high fructose diet for 8 weeks. For CS exposure experiment, these mice were exposed to CS for 28 days according to OECD guideline 412. Our results clearly showed that the immune system was suppressed and ER stress was induced in mice with exposure to CS and fed with high fructose. Furthermore, their concentrations of adipokines including leptin and adiponectin were aberrant. Such alteration in secretion of adipokines could cause insulin resistance which may lead to the development of type 2 diabetes. Copyright © 2017 Elsevier Inc. All rights reserved.

A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes.

PubMed

Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme.

Comparative Proteome Analysis in Schizosaccharomyces pombe Identifies Metabolic Targets to Improve Protein Production and Secretion*

PubMed Central

Hung, Chien-Wen; Klein, Tobias; Cassidy, Liam; Linke, Dennis; Lange, Sabrina; Anders, Uwe; Bureik, Matthias; Heinzle, Elmar; Schneider, Konstantin; Tholey, Andreas

2016-01-01

Protein secretion in yeast is a complex process and its efficiency depends on a variety of parameters. We performed a comparative proteome analysis of a set of Schizosaccharomyces pombe strains producing the α-glucosidase maltase in increasing amounts to investigate the overall proteomic response of the cell to the burden of protein production along the various steps of protein production and secretion. Proteome analysis of these strains, utilizing an isobaric labeling/two dimensional LC-MALDI MS approach, revealed complex changes, from chaperones and secretory transport machinery to proteins controlling transcription and translation. We also found an unexpectedly high amount of changes in enzyme levels of the central carbon metabolism and a significant up-regulation of several amino acid biosyntheses. These amino acids were partially underrepresented in the cellular protein compared with the composition of the model protein. Additional feeding of these amino acids resulted in a 1.5-fold increase in protein secretion. Membrane fluidity was identified as a second bottleneck for high-level protein secretion and addition of fluconazole to the culture caused a significant decrease in ergosterol levels, whereas protein secretion could be further increased by a factor of 2.1. In summary, we show that high level protein secretion causes global changes of protein expression levels in the cell and that precursor availability and membrane composition limit protein secretion in this yeast. In this respect, comparative proteome analysis is a powerful tool to identify targets for an efficient increase of protein production and secretion in S. pombe. Data are available via ProteomeXchange with identifiers PXD002693 and PXD003016. PMID:27477394

Antimicrobial Lipids: Novel Innate Defense Molecules are Elevated in Sinus Secretions of Patients with Chronic Rhinosinusitis

PubMed Central

Lee, Jivianne T.; Jansen, Mike; Yilma, Abebayehu N.; Nguyen, Angels; Desharnais, Robert; Porter, Edith

2010-01-01

Introduction Airway secretions possess intrinsic antimicrobial properties that contribute to the innate host defense of the respiratory tract. These microbicidal capabilities have largely been attributed to the presence of antibacterial polypeptides. However, recent investigation has demonstrated that host-derived lipids including cholesteryl esters also exhibit antimicrobial properties. The purpose of this study was to determine whether sinus secretions contain such antimicrobial lipids and to compare the lipid composition in patients with and without chronic rhinosinusitis (CRS). Methods Maxillary sinus fluid was obtained via antral lavage from subjects with (7) and without (9) a history of CRS. Following specimen collection, total lipid was extracted according to Bligh & Dyer and lipid profiles were obtained by reverse phase HPLC on an amide-embedded C18 column. In addition, the neutrophil specific antimicrobial peptides HNP1-3 were quantified by immunoblotting. Results Lipids were identified in the maxillary sinus secretions of patients with and without CRS including cholesteryl esters. However, levels of lipid composition differed between the two groups with CRS patients exhibiting greater amounts of all classes of lipids; reaching over 10-fold higher concentration when compared to nonCRS patients. This increase was independent of HNP1-3 content. Conclusions Sinus secretions of patients with CRS appear to demonstrate elevated levels of antimicrobial lipids compared to controls independent from neutrophil influx. This upregulation suggests that host-derived lipids act as mediators of mucosal immunity in CRS. Further study is necessary to determine if such antimicrobial lipids function alone or synergistically with antibacterial peptides in conferring such inherent microbicidal properties. PMID:20338107

Contribution of single amino acid and codon substitutions to the production and secretion of a lipase by Bacillus subtilis.

PubMed

Skoczinski, Pia; Volkenborn, Kristina; Fulton, Alexander; Bhadauriya, Anuseema; Nutschel, Christina; Gohlke, Holger; Knapp, Andreas; Jaeger, Karl-Erich

2017-09-25

Bacillus subtilis produces and secretes proteins in amounts of up to 20 g/l under optimal conditions. However, protein production can be challenging if transcription and cotranslational secretion are negatively affected, or the target protein is degraded by extracellular proteases. This study aims at elucidating the influence of a target protein on its own production by a systematic mutational analysis of the homologous B. subtilis model protein lipase A (LipA). We have covered the full natural diversity of single amino acid substitutions at 155 positions of LipA by site saturation mutagenesis excluding only highly conserved residues and qualitatively and quantitatively screened about 30,000 clones for extracellular LipA production. Identified variants with beneficial effects on production were sequenced and analyzed regarding B. subtilis growth behavior, extracellular lipase activity and amount as well as changes in lipase transcript levels. In total, 26 LipA variants were identified showing an up to twofold increase in either amount or activity of extracellular lipase. These variants harbor single amino acid or codon substitutions that did not substantially affect B. subtilis growth. Subsequent exemplary combination of beneficial single amino acid substitutions revealed an additive effect solely at the level of extracellular lipase amount; however, lipase amount and activity could not be increased simultaneously. Single amino acid and codon substitutions can affect LipA secretion and production by B. subtilis. Several codon-related effects were observed that either enhance lipA transcription or promote a more efficient folding of LipA. Single amino acid substitutions could improve LipA production by increasing its secretion or stability in the culture supernatant. Our findings indicate that optimization of the expression system is not sufficient for efficient protein production in B. subtilis. The sequence of the target protein should also be considered as an optimization target for successful protein production. Our results further suggest that variants with improved properties might be identified much faster and easier if mutagenesis is prioritized towards elements that contribute to enzymatic activity or structural integrity.

On the mode of action of ACTH on the isolated perfused adrenal gland

PubMed Central

Jaanus, Siret D.; Rosenstein, M. J.; Rubin, R. P.

1970-01-01

1. Isolated cat adrenal glands were perfused with Locke solution, and the corticosteroid outputs in response to adrenocorticotrophin (ACTH) were studied. 2. Steroid outputs varied with the ACTH concentration, as well as with the duration of exposure to a given ACTH concentration. 3. Omission of calcium from the perfusion medium markedly depressed ACTH-evoked steroid release. The steroid output was directly related to the extracellular calcium concentration up to 0·5 mM. 4. During a constant exposure to ACTH, steroid output was maintained for at least 2-3 hr, provided that calcium was present in the perfusion medium. 5. Strontium, but not barium or magnesium, replaced calcium in maintaining the secretory response to ACTH. 6. Magnesium depressed ACTH-evoked secretion in the presence of calcium, and this depression of secretion was antagonized by increasing the calcium concentration. 7. Prolonged perfusion with sodium-free or potassium-free solutions did not markedly inhibit steroid output in response to ACTH. Excess potassium (56 mM) did not produce a consistent or marked increase in spontaneous steroid output and did not affect the response to ACTH. 8. The steroid content of adrenal glands perfused with Locke solution and exposed to ACTH was about 10% of the amount which was secreted. By contrast, adrenal glands perfused with calcium-free media and exposed to ACTH contained much higher amounts of steroid, despite the negligible amount secreted. 9. These data suggest that calcium plays a critical role in the mechanism of corticosteroid secretion from the adrenal cortex. PMID:4322584

The changes of proteins and polysaccharides in extracellular polymeric substance for Spirogyra fluviatilis under different salinity

NASA Astrophysics Data System (ADS)

Lee, Yichao; Chang, Shuiping

2017-05-01

Spirogyra is a genus of widely distributed, large green fresh water algae. This study discovered that changes in salinity can induce Spirogyra fluviatilis to produce amounts of extracellular polymeric substance (EPS) when controlling other environmental conditions. If culturing S. fluviatilis with salinity greater than a 3.0‰ medium for 4 hours, the secretion EPS will be changed. And the level of polysaccharides and proteins, the primary components of EPS, is slightly increased in accordance with the increase in the salinity. But the proteins to polysaccharides ratio changes are not significantly

Production of matrix metalloproteinases in response to mycobacterial infection.

PubMed

Quiding-Järbrink, M; Smith, D A; Bancroft, G J

2001-09-01

Matrix metalloproteinases (MMPs) constitute a large family of enzymes with specificity for the various proteins of the extracellular matrix which are implicated in tissue remodeling processes and chronic inflammatory conditions. To investigate the role of MMPs in immunity to mycobacterial infections, we incubated murine peritoneal macrophages with viable Mycobacterium bovis BCG or Mycobacterium tuberculosis H37Rv and assayed MMP activity in the supernatants by zymography. Resting macrophages secreted only small amounts of MMP-9 (gelatinase B), but secretion increased dramatically in a dose-dependent manner in response to either BCG or M. tuberculosis in vitro. Incubation with mycobacteria also induced increased MMP-2 (gelatinase A) activity. Neutralization of tumor necrosis alpha (TNF-alpha), and to a lesser extent interleukin 18 (IL-18), substantially reduced MMP production in response to mycobacteria. Exogenous addition of TNF-alpha or IL-18 induced macrophages to express MMPs, even in the absence of bacteria. The immunoregulatory cytokines gamma interferon (IFN-gamma), IL-4, and IL-10 all suppressed BCG-induced MMP production, but through different mechanisms. IFN-gamma treatment increased macrophage secretion of TNF-alpha but still reduced their MMP activity. Conversely, IL-4 and IL-10 seemed to act by reducing the amount of TNF-alpha available to the macrophages. Finally, infection of BALB/c or severe combined immunodeficiency (SCID) mice with either BCG or M. tuberculosis induced substantial increases in MMP-9 activity in infected tissues. In conclusion, we show that mycobacterial infection induces MMP-9 activity both in vitro and in vivo and that this is regulated by TNF-alpha, IL-18, and IFN-gamma. These findings indicate a possible contribution of MMPs to tissue remodeling processes that occur in mycobacterial infections.

Chemical composition of the frontal gland secretion ofSyntermes soldiers (Isoptera, Termitidae).

PubMed

Baker, R; Coles, H R; Edwards, M; Evans, D A; Howse, P E; Walmsley, S

1981-01-01

The defensive secretions from the frontal glands of soldier termites of the genusSyntermes contain similar mixtures of mono- and sesquiterpene hydrocarbons. The major components inS. dirus, S. molestus, S. brevimalatus, S. peruanus, and a new species (Syntermes sp. n), iscis-β-ocimene. A substantial amount of aristolochene is found inSyntermes sp. n. and is present at lower levels in all the other species;S. brevimalatus contains onlycis-β-ocimene and aristolochene. The four other species also contain minor amounts of epi-α-selinene and germacrene A. The latter compound has been identified on the basis of its rearrangement product β-elemene. The termiteS. grandis differed markedly from the otherSyntermes species in that no terpenoid components were found in the soldier extract. With the obvious exception ofS. grandis, the same soldier-specific mono- and sesquiterpenes occurred in all species. The total amount of secretion per unit weight of soldiers varies with the species and is inversely proportional to the development of the mandibular apparatus. InS. molestus smaller gland size is compensated for by a greater number of soldiers foraging trails.

A self-sampling method to obtain large volumes of undiluted cervicovaginal secretions.

PubMed

Boskey, Elizabeth R; Moench, Thomas R; Hees, Paul S; Cone, Richard A

2003-02-01

Studies of vaginal physiology and pathophysiology sometime require larger volumes of undiluted cervicovaginal secretions than can be obtained by current methods. A convenient method for self-sampling these secretions outside a clinical setting can facilitate such studies of reproductive health. The goal was to develop a vaginal self-sampling method for collecting large volumes of undiluted cervicovaginal secretions. A menstrual collection device (the Instead cup) was inserted briefly into the vagina to collect secretions that were then retrieved from the cup by centrifugation in a 50-ml conical tube. All 16 women asked to perform this procedure found it feasible and acceptable. Among 27 samples, an average of 0.5 g of secretions (range, 0.1-1.5 g) was collected. This is a rapid and convenient self-sampling method for obtaining relatively large volumes of undiluted cervicovaginal secretions. It should prove suitable for a wide range of assays, including those involving sexually transmitted diseases, microbicides, vaginal physiology, immunology, and pathophysiology.

Molecular pathology of prostate cancer.

PubMed

Cazares, L H; Drake, R R; Esquela-Kirscher, A; Lance, R S; Semmes, O J; Troyer, D A

2010-01-01

This chapter includes discussion of the molecular pathology of tissue, blood, urine, and expressed prostatic secretions. Because we are unable to reliably image the disease in vivo, a 12 core method that oversamples the peripheral zone is widely used. This generates large numbers of cores that need to be carefully processed and sampled. In spite of the large number of tissue cores, the amount of tumor available for study is often quite limited. This is a particular challenge for research, as new biomarker assays will need to preserve tissue architecture intact for histopathology. Methods of processing and reporting pathology are discussed. With the exception of ductal variants, recognized subtypes of prostate cancer are largely confined to research applications, and most prostate cancers are acinar. Biomarker discovery in urine and expressed prostatic secretions would be useful since these are readily obtained and are proximate fluids. The well-known challenges of biomarker discovery in blood and urine are referenced and discussed. Mediators of carcinogenesis can serve as biomarkers as exemplified by mutations in PTEN and TMPRSS2:ERG fusion. The use of proteomics in biomarker discovery with an emphasis on imaging mass spectroscopy of tissues is discussed. Small RNAs are of great interest, however, their usefulness as biomarkers in clinical decision making remains the subject of ongoing research. The chapter concludes with an overview of blood biomarkers such as circulating nucleic acids and tumor cells and bound/free isoforms of prostate specific antigen (PSA).

Is there adaptation of the exocrine pancreas in wild animal? The case of the Roe deer.

PubMed

Guilloteau, Paul; Vitari, Francesca; Metzinger-Le Meuth, Valérie; Le Normand, Laurence; Romé, Véronique; Savary, Gérard; Delaby, Luc; Domeneghini, Cinzia; Morisset, Jean

2012-05-28

Physiology of the exocrine pancreas has been well studied in domestic and in laboratory animals as well as in humans. However, it remains quite unknown in wildlife mammals. Roe deer and cattle (including calf) belong to different families but have a common ancestor. This work aimed to evaluate in the Roe deer, the adaptation to diet of the exocrine pancreatic functions and regulations related to animal evolution and domestication. Forty bovine were distributed into 2 groups of animals either fed exclusively with a milk formula (monogastric) or fed a dry feed which allowed for rumen function to develop, they were slaughtered at 150 days of age. The 35 Roe deer were wild animals living in the temperate broadleaf and mixed forests, shot during the hunting season and classified in two groups adult and young. Immediately after death, the pancreas was removed for tissue sample collection and then analyzed. When expressed in relation to body weight, pancreas, pancreatic protein weights and enzyme activities measured were higher in Roe deer than in calf. The 1st original feature is that in Roe deer, the very high content in pancreatic enzymes seems to be related to specific digestive products observed (proline-rich proteins largely secreted in saliva) which bind tannins, reducing their deleterious effects on protein digestion. The high chymotrypsin and elastase II quantities could allow recycling of proline-rich proteins. In contrast, domestication and rearing cattle resulted in simplified diet with well digestible components. The 2nd feature is that in wild animal, both receptor subtypes of the CCK/gastrin family peptides were present in the pancreas as in calf, although CCK-2 receptor subtype was previously identified in higher mammals. Bovine species could have lost some digestive capabilities (no ingestion of great amounts of tannin-rich plants, capabilities to secrete high amounts of proline-rich proteins) compared with Roe deer species. CCK and gastrin could play an important role in the regulation of pancreatic secretion in Roe deer as in calf. This work, to the best of our knowledge is the first study which compared the Roe deer adaptation to diet with a domesticated animal largely studied.

The Physiological Suppressing Factors of Dry Forage Intake and the Cause of Water Intake Following Dry Forage Feeding in Goats — A Review

PubMed Central

Sunagawa, Katsunori; Nagamine, Itsuki

2016-01-01

The goats raised in the barn are usually fed on fresh grass. As dry forage can be stored for long periods in large amounts, dry forage feeding makes it possible to feed large numbers of goats in barns. This review explains the physiological factors involved in suppressing dry forage intake and the cause of drinking following dry forage feeding. Ruminants consume an enormous amount of dry forage in a short time. Eating rates of dry forage rapidly decreased in the first 40 min of feeding and subsequently declined gradually to low states in the remaining time of the feeding period. Saliva in large-type goats is secreted in large volume during the first hour after the commencement of dry forage feeding. It was elucidated that the marked suppression of dry forage intake during the first hour was caused by a feeding-induced hypovolemia and the loss of NaHCO3 due to excessive salivation during the initial stages of dry forage feeding. On the other hand, it was indicated that the marked decrease in feed intake observed in the second hour of the 2 h feeding period was related to ruminal distension caused by the feed consumed and the copious amount of saliva secreted during dry forage feeding. In addition, results indicate that the marked decreases in dry forage intake after 40 min of feeding are caused by increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding. After 40 min of the 2 h dry forage feeding period, the feed salt content is absorbed into the rumen and plasma osmolality increases. The combined effects of ruminal distension and increased plasma osmolality accounted for 77.6% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality are the main physiological factors in suppression of dry forage intake in large-type goats. There was very little drinking behavior observed during the first hour of the 2 h feeding period most water consumption occurring in the second hour. The cause of this thirst sensation during the second hour of dry forage feeding period was not hypovolemia brought about by excessive salivation, but rather increases in plasma osmolality due to the ruminal absorption of salt from the consumed feed. This suggests the water intake following dry forage feeding is determined by the level of salt content in the feed. PMID:26732440

Roles of silkworm endoplasmic reticulum chaperones in the secretion of recombinant proteins expressed by baculovirus system.

PubMed

Imai, Saki; Kusakabe, Takahiro; Xu, Jian; Li, Zhiqing; Shirai, Shintaro; Mon, Hiroaki; Morokuma, Daisuke; Lee, Jae Man

2015-11-01

Baculovirus expression vector system (BEVS) is widely used for production of recombinant eukaryotic proteins in insect larvae or cultured cells. BEVS has advantages over bacterial expression system in producing post-translationally modified secreted proteins. However, for some unknown reason, it is very difficult for insects to secrete sufficiently for certain proteins of interest. To understand the reasons why insect cells fail to secrete some kinds of recombinant proteins, we here employed three mammalian proteins as targets, EPO, HGF, and Wnt3A, with different secretion levels in BEVS and investigated their mRNA transcriptions from the viral genome, subcellular localizations, and interactions with silkworm ER chaperones. Moreover, we observed that no significantly influence on the secretion amounts of all three proteins when depleting or overexpressing most endogenous ER chaperone genes in cultured silkworm cells. However, among all detected ER chaperones, the depletion of BiP severely decreased the recombinant protein secretion in BEVS, indicating the possible central role of Bip in silkworm secretion pathway.

Cystic Fibrosis Heterozygote Resistance to Cholera Toxin in the Cystic Fibrosis Mouse Model

NASA Astrophysics Data System (ADS)

Gabriel, Sherif E.; Brigman, Kristen N.; Koller, Beverly H.; Boucher, Richard C.; Stutts, M. Jackson

1994-10-01

The effect of the number of cystic fibrosis (CF) alleles on cholera toxin (CT)-induced intestinal secretion was examined in the CF mouse model. CF mice that expressed no CF transmembrane conductance regulator (CFTR) protein did not secrete fluid in response to CT. Heterozygotes expressed 50 percent of the normal amount of CFTR protein in the intestinal epithelium and secreted 50 percent of the normal fluid and chloride ion in response to CT. This correlation between CFTR protein and CT-induced chloride ion and fluid secretion suggests that CF heterozygotes might possess a selective advantage of resistance to cholera.

[The effect of bombesin and its analogs on the secretion of gastric juice and its content of pepsin and hydrochloric acid].

PubMed

Barashkova, G M; Klimov, P K; Kuranova, I L; Churkina, S I; Filonova, E B

1990-07-01

I.V. Infusion of bombesine after eating raw meat inhibited for 30-60 min the secretion of gastric juice and hydrochloric acid in dogs. Within 90-120 min of simultaneous infusion of pentagastrin and bombesine, the amount of secreted juice and its acidity decreased and then the secretion of gastric parietal cells increased. Simultaneous infusion of histamine and bombesine increased the response of gastric parietal cells during the whole experiment as compared with the histamine effect alone. Microapplication of bombesine into cerebral structures also decreased the secretory response of the parietal cells.

Antimicrobial lipids: novel innate defense molecules are elevated in sinus secretions of patients with chronic rhinosinusitis.

PubMed

Lee, Jivianne T; Jansen, Mike; Yilma, Abebayehu N; Nguyen, Angels; Desharnais, Robert; Porter, Edith

2010-01-01

Airway secretions possess intrinsic antimicrobial properties that contribute to the innate host defense of the respiratory tract. These microbicidal capabilities have largely been attributed to the presence of antibacterial polypeptides. However, recent investigation has indicated that host-derived lipids including cholesteryl esters also exhibit antimicrobial properties. The purpose of this study was to determine whether sinus secretions contain such antimicrobial lipids and to compare the lipid composition in patients with and without chronic rhinosinusitis (CRS). Maxillary sinus fluid was obtained via antral lavage from subjects with (seven patients) and without (nine patients) a history of CRS. After specimen collection, total lipid was extracted according to Bligh and Dyer (Bligh EG and Dyer WJ, A rapid method of total lipid extraction and purification, Can J Biochem Physiol 37:911-918, 1959) and lipid profiles were obtained by reverse phase high-performance liquid chromatography on an amide-embedded C18 column. In addition, the neutrophil-specific antimicrobial peptides human neutrophil peptides 1-3 (HNP1-3) were quantified by Western immunoblotting. Lipids, including cholesteryl esters, were identified in the maxillary sinus secretions of patients with and without CRS. However, levels of lipid composition differed between the two groups with CRS patients exhibiting greater amounts of all classes of lipids, reaching over 10-fold higher concentration when compared with non-CRS patients. This increase was independent of HNP1-3 content. Sinus secretions of patients with CRS appear to show elevated levels of antimicrobial lipids compared with controls independent from neutrophil influx. This up-regulation suggests that host-derived lipids act as mediators of mucosal immunity in CRS. Further study is necessary to determine if such antimicrobial lipids function alone or synergistically with antibacterial peptides in conferring such inherent microbicidal properties.

Auxin Deprivation Induces Synchronous Golgi Differentiation in Suspension-Cultured Tobacco BY-2 Cells1

PubMed Central

Winicur, Zev M.; Feng Zhang, Guo; Andrew Staehelin, L.

1998-01-01

To date, the lack of a method for inducing plant cells and their Golgi stacks to differentiate in a synchronous manner has made it difficult to characterize the nature and extent of Golgi retailoring in biochemical terms. Here we report that auxin deprivation can be used to induce a uniform population of suspension-cultured tobacco (Nicotiana tabacum cv BY-2) cells to differentiate synchronously during a 4-d period. Upon removal of auxin, the cells stop dividing, undergo elongation, and differentiate in a manner that mimics the formation of slime-secreting epidermal and peripheral root-cap cells. The morphological changes to the Golgi apparatus include a proportional increase in the number of trans-Golgi cisternae, a switch to larger-sized secretory vesicles that bud from the trans-Golgi cisternae, and an increase in osmium staining of the secretory products. Biochemical alterations include an increase in large, fucosylated, mucin-type glycoproteins, changes in the types of secreted arabinogalactan proteins, and an increase in the amounts and types of molecules containing the peripheral root-cap-cell-specific epitope JIM 13. Taken together, these findings support the hypothesis that auxin deprivation can be used to induce tobacco BY-2 cells to differentiate synchronously into mucilage-secreting cells. PMID:9625703

Expression of lignocellulolytic enzymes in Pichia pastoris

PubMed Central

2012-01-01

Background Sustainable utilization of plant biomass as renewable source for fuels and chemical building blocks requires a complex mixture of diverse enzymes, including hydrolases which comprise the largest class of lignocellulolytic enzymes. These enzymes need to be available in large amounts at a low price to allow sustainable and economic biotechnological processes. Over the past years Pichia pastoris has become an attractive host for the cost-efficient production and engineering of heterologous (eukaryotic) proteins due to several advantages. Results In this paper codon optimized genes and synthetic alcohol oxidase 1 promoter variants were used to generate Pichia pastoris strains which individually expressed cellobiohydrolase 1, cellobiohydrolase 2 and beta-mannanase from Trichoderma reesei and xylanase A from Thermomyces lanuginosus. For three of these enzymes we could develop strains capable of secreting gram quantities of enzyme per liter in fed-batch cultivations. Additionally, we compared our achieved yields of secreted enzymes and the corresponding activities to literature data. Conclusion In our experiments we could clearly show the importance of gene optimization and strain characterization for successfully improving secretion levels. We also present a basic guideline how to correctly interpret the interplay of promoter strength and gene dosage for a successful improvement of the secretory production of lignocellulolytic enzymes in Pichia pastoris. PMID:22583625

A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes

PubMed Central

Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme. PMID:28072851

Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation.

PubMed

Koymans, Kirsten J; Vrieling, Manouk; Gorham, Ronald D; van Strijp, Jos A G

2017-01-01

Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.

The altered expression of perineuronal net elements during neural differentiation.

PubMed

Eskici, Nazli F; Erdem-Ozdamar, Sevim; Dayangac-Erden, Didem

2018-01-01

Perineuronal nets (PNNs), which are localized around neurons during development, are specialized forms of neural extracellular matrix with neuroprotective and plasticity-regulating roles. Hyaluronan and proteoglycan link protein 1 (HAPLN1), tenascin-R (TNR) and aggrecan (ACAN) are key elements of PNNs. In diseases characterized by neuritogenesis defects, the expression of these proteins is known to be downregulated, suggesting that PNNs may have a role in neural differentiation. In this study, the mRNA and protein levels of HAPLN1, TNR and ACAN were determined and compared at specific time points of neural differentiation. We used PC12 cells as the in vitro model because they reflect this developmental process. On day 7, the HAPLN1 mRNA level showed a 2.9-fold increase compared to the non-differentiated state. However, the cellular HAPLN1 protein level showed a decrease, indicating that the protein may have roles in neural differentiation, and may be secreted during the early period of differentiation. By contrast, TNR mRNA and protein levels remained unchanged, and the amount of cellular ACAN protein showed a 3.7-fold increase at day 7. These results suggest that ACAN may be secreted after day 7, possibly due to its large amount of post-translational modifications. Our results provide preliminary data on the expression of PNN elements during neural differentiation. Further investigations will be performed on the role of these elements in neurological disease models.

Characterisation of adipocyte-derived extracellular vesicle subtypes identifies distinct protein and lipid signatures for large and small extracellular vesicles

PubMed Central

Durcin, Maëva; Fleury, Audrey; Taillebois, Emiliane; Hilairet, Grégory; Krupova, Zuzana; Henry, Céline; Truchet, Sandrine; Trötzmüller, Martin; Köfeler, Harald; Mabilleau, Guillaume; Hue, Olivier; Andriantsitohaina, Ramaroson; Martin, Patrice; Le Lay, Soazig

2017-01-01

ABSTRACT Extracellular vesicles (EVs) are biological vectors that can modulate the metabolism of target cells by conveying signalling proteins and genomic material. The level of EVs in plasma is significantly increased in cardiometabolic diseases associated with obesity, suggesting their possible participation in the development of metabolic dysfunction. With regard to the poor definition of adipocyte-derived EVs, the purpose of this study was to characterise both qualitatively and quantitatively EVs subpopulations secreted by fat cells. Adipocyte-derived EVs were isolated by differential centrifugation of conditioned media collected from 3T3-L1 adipocytes cultured for 24 h in serum-free conditions. Based on morphological and biochemical properties, as well as quantification of secreted EVs, we distinguished two subpopulations of adipocyte-derived EVs, namely small extracellular vesicles (sEVs) and large extracellular vesicles (lEVs). Proteomic analyses revealed that lEVs and sEVs exhibit specific protein signatures, allowing us not only to define novel markers of each population, but also to predict their biological functions. Despite similar phospholipid patterns, the comparative lipidomic analysis performed on these EV subclasses revealed a specific cholesterol enrichment of the sEV population, whereas lEVs were characterised by high amounts of externalised phosphatidylserine. Enhanced secretion of lEVs and sEVs is achievable following exposure to different biological stimuli related to the chronic low-grade inflammation state associated with obesity. Finally, we demonstrate the ability of primary murine adipocytes to secrete sEVs and lEVs, which display physical and biological characteristics similar to those described for 3T3-L1. Our study provides additional information and elements to define EV subtypes based on the characterisation of adipocyte-derived EV populations. It also underscores the need to distinguish EV subpopulations, through a combination of multiple approaches and markers, since their specific composition may cause distinct metabolic responses in recipient cells and tissues. PMID:28473884

Host-Pathogen Interactions: I. A Correlation Between α-Galactosidase Production and Virulence 1

PubMed Central

English, Patricia D.; Albersheim, Peter

1969-01-01

Resistance or susceptibility of Red Kidney, Pinto and Small White beans (Phaseolus vulgaris) to the alpha, beta, and gamma strains of Colletotrichum lindemuthianum was either confirmed or established. These fungal strains secrete α-galactosidase, β-galactosidase and β-xylosidase when grown on cell walls isolated from the hypocotyls of any of the above bean varieties. These enzymes effectively degrade cell walls isolated from susceptible 5-day old hypocotyls but degrade only slightly the walls isolated from resistant 18-day old hypocotyls. The amounts of the β-galactosidase and β-xylosidase secreted by the 3 fungal strains are relatively low and are approximately equivalent. The secretion of these 2 enzymes is not dependent upon the bean variety from which the hypocotyl cell walls used as a carbon source were isolated. However, the fungal strains secrete greater amounts of α-galactosidase when grown on hypocotyl cell walls isolated from susceptible plants than when grown on walls from resistant plants. Virulent isolates of the fungus, when grown on hypocotyl cell walls isolated from a susceptible plant, secrete more α-galactosidase than do attenuated (avirulent) isolates of the same fungal strain grown under the same conditions. The α-galactosidase secreted by each of the fungal strains is capable of removing galactose from the hypocotyl cell walls of each bean variety tested. Galactose is removed from the cell walls of each variety at the same rate regardless of whether the cell walls were isolated from a susceptible or resistant plant. PMID:16657049

Experimental quantum data locking

NASA Astrophysics Data System (ADS)

Liu, Yang; Cao, Zhu; Wu, Cheng; Fukuda, Daiji; You, Lixing; Zhong, Jiaqiang; Numata, Takayuki; Chen, Sijing; Zhang, Weijun; Shi, Sheng-Cai; Lu, Chao-Yang; Wang, Zhen; Ma, Xiongfeng; Fan, Jingyun; Zhang, Qiang; Pan, Jian-Wei

2016-08-01

Classical correlation can be locked via quantum means: quantum data locking. With a short secret key, one can lock an exponentially large amount of information in order to make it inaccessible to unauthorized users without the key. Quantum data locking presents a resource-efficient alternative to one-time pad encryption which requires a key no shorter than the message. We report experimental demonstrations of a quantum data locking scheme originally proposed by D. P. DiVincenzo et al. [Phys. Rev. Lett. 92, 067902 (2004), 10.1103/PhysRevLett.92.067902] and a loss-tolerant scheme developed by O. Fawzi et al. [J. ACM 60, 44 (2013), 10.1145/2518131]. We observe that the unlocked amount of information is larger than the key size in both experiments, exhibiting strong violation of the incremental proportionality property of classical information theory. As an application example, we show the successful transmission of a photo over a lossy channel with quantum data (un)locking and error correction.

Correspondence of High Levels of Beta-Exotoxin I and the Presence of cry1B in Bacillus thuringiensis

PubMed Central

Espinasse, Sylvain; Gohar, Michel; Chaufaux, Josette; Buisson, Christophe; Perchat, Stéphane; Sanchis, Vincent

2002-01-01

Examination of 640 natural isolates of Bacillus thuringiensis showed that the 58 strains (9%) whose supernatants were toxic to Anthonomus grandis (Coleoptera: Curculionidae) produced between 10 and 175 μg of β-exotoxin I per ml. We also found that 55 (46%) of a sample of 118 strains whose culture supernatants were not toxic to A. grandis nevertheless produced between 2 and 5 μg/ml. However, these amounts of β-exotoxin I were below the threshold for detectable toxicity against this insect species. Secretion of large amounts of β-exotoxin I was strongly associated with the presence of cry1B and vip2 genes in the 640 natural B. thuringiensis isolates studied. We concluded that strains carrying cry1B and vip2 genes also possess, on the same plasmid, genetic determinants necessary to promote high levels of production of β-exotoxin I. PMID:12200263

The Genetic Program of Pancreatic β-Cell Replication In Vivo

PubMed Central

Klochendler, Agnes; Caspi, Inbal; Corem, Noa; Moran, Maya; Friedlich, Oriel; Elgavish, Sharona; Nevo, Yuval; Helman, Aharon; Glaser, Benjamin; Eden, Amir; Itzkovitz, Shalev

2016-01-01

The molecular program underlying infrequent replication of pancreatic β-cells remains largely inaccessible. Using transgenic mice expressing green fluorescent protein in cycling cells, we sorted live, replicating β-cells and determined their transcriptome. Replicating β-cells upregulate hundreds of proliferation-related genes, along with many novel putative cell cycle components. Strikingly, genes involved in β-cell functions, namely, glucose sensing and insulin secretion, were repressed. Further studies using single-molecule RNA in situ hybridization revealed that in fact, replicating β-cells double the amount of RNA for most genes, but this upregulation excludes genes involved in β-cell function. These data suggest that the quiescence-proliferation transition involves global amplification of gene expression, except for a subset of tissue-specific genes, which are “left behind” and whose relative mRNA amount decreases. Our work provides a unique resource for the study of replicating β-cells in vivo. PMID:26993067

Securing Secrets and Managing Trust in Modern Computing Applications

ERIC Educational Resources Information Center

Sayler, Andy

2016-01-01

The amount of digital data generated and stored by users increases every day. In order to protect this data, modern computing systems employ numerous cryptographic and access control solutions. Almost all of such solutions, however, require the keeping of certain secrets as the basis of their security models. How best to securely store and control…

Alveolar type II cell-fibroblast interactions, synthesis and secretion of surfactant and type I collagen.

PubMed

Griffin, M; Bhandari, R; Hamilton, G; Chan, Y C; Powell, J T

1993-06-01

During alveolar development and alveolar repair close contacts are established between fibroblasts and lung epithelial cells through gaps in the basement membrane. Using co-culture systems we have investigated whether these close contacts influence synthesis and secretion of the principal surfactant apoprotein (SP-A) by cultured rat lung alveolar type II cells and the synthesis and secretion of type I collagen by fibroblasts. The alveolar type II cells remained cuboidal and grew in colonies on fibroblast feeder layers and on Matrigel-coated cell culture inserts but were progressively more flattened on fixed fibroblast monolayers and plastic. Alveolar type II cells cultured on plastic released almost all their SP-A into the medium by 4 days. Alveolar type II cells cultured on viable fibroblasts or Matrigel-coated inserts above fibroblasts accumulated SP-A in the medium at a constant rate for the first 4 days, and probably recycle SP-A by endocytosis. The amount of mRNA for SP-A was very low after 4 days of culture of alveolar type II cells on plastic, Matrigel-coated inserts or fixed fibroblast monolayers: relatively, the amount of mRNA for SP-A was increased 4-fold after culture of alveolar type II cells on viable fibroblasts. Co-culture of alveolar type II cells with confluent human dermal fibroblasts stimulated by 2- to 3-fold the secretion of collagen type I into the culture medium, even after the fibroblasts' growth had been arrested with mitomycin C. Collagen secretion, by fibroblasts, also was stimulated 2-fold by conditioned medium from alveolar type II cells cultured on Matrigel. The amount of mRNA for type I collagen increased only modestly when fibroblasts were cultured in this conditioned medium. This stimulation of type I collagen secretion diminished as the conditioned medium was diluted out, but at high dilutions further stimulation occurred, indicating that a factor that inhibited collagen secretion also was being diluted out. The conditioned medium contained low levels of IGF-1 and the stimulation of type I collagen secretion was abolished when the conditioned medium was pre-incubated with antibodies to insulin-like growth factor 1 (IGF-1). There are important reciprocal interactions between alveolar type II cells and fibroblasts in co-culture. Direct contacts between alveolar type II cells and fibroblasts appear to have a trophic effect on cultured alveolar type II cells, increasing the levels of mRNA for SP-A. Rat lung alveolar type II cells appear to release a factor (possibly IGF-1) that stimulates type I collagen secretion by fibroblasts.

Production and purification of staphylococcal nuclease in Lactococcus lactis using a new expression-secretion system and a pH-regulated mini-reactor

PubMed Central

2010-01-01

Background Staphylococcal (or micrococcal) nuclease or thermonuclease (SNase or Nuc) is a naturally-secreted nucleic acid degrading enzyme that participates in Staphylococcus aureus spread in the infected host. Purified Nuc protein can be used as an exogenous reagent to clear cellular extracts and improve protein purification. Here, a recombinant form of Nuc was produced and secreted in a Gram-positive host, Lactococcus lactis, and purified from the culture medium. Results The gene segment corresponding to the S. aureus nuclease without its signal peptide was cloned in an expression-secretion vector. It was then fused to a lactococcal sequence encoding a signal peptide, and expressed under the control of a lactococcal promoter that is inducible by zinc starvation. An L. lactis subsp cremoris model strain (MG1363) transformed with the resulting plasmid was grown in either of two media (GM17v and CDM) that are free of animal compounds, allowing GMP (Good Manufacturing Practice) production. Induction conditions (concentration of the metal chelator EDTA and timing of addition) in small-scale pH-regulated fermentors were optimized using LacMF (Lactis Multi-Fermentor), a home-made parallel fermentation control system able to monitor 12 reactors simultaneously. Large amounts of recombinant Nuc (rNuc) were produced and secreted in both media, and rNuc was purified from GM17v medium in a single-step procedure. Conclusions In L. lactis, rNuc production and secretion were optimal after induction by 0.5 mM EDTA in small scale (200 mL) GM17v exponential phase cultures (at an OD600 of 2), leading to a maximal protein yield of 210 mg per L of culture medium. Purified rNuc was highly active, displaying a specific activity of 2000 U/mg. PMID:20492646

Secret-key expansion from covert communication

NASA Astrophysics Data System (ADS)

Arrazola, Juan Miguel; Amiri, Ryan

2018-02-01

Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.

Absence of CD9 reduces endometrial VEGF secretion and impairs uterine repair after parturition.

PubMed

Kawano, Natsuko; Miyado, Kenji; Yoshii, Noriko; Kanai, Seiya; Saito, Hidekazu; Miyado, Mami; Inagaki, Noboru; Odawara, Yasushi; Hamatani, Toshio; Umezawa, Akihiro

2014-04-16

In mammals, uterine epithelium is remodeled cyclically throughout adult life for pregnancy. Despite the expression of CD9 in the uterine epithelium, its role in maternal reproduction is unclear. Here, we addressed this issue by examining uterine secretions collected from patients undergoing fertility treatment and fertilization-competent Cd9(-/-) mice expressing CD9-GFP in their eggs (Cd9(-/-)TG). CD9 in uterine secretions was observed as extracellular matrix-like feature, and its amount of the secretions associated with repeated pregnancy failures. We also found that the litter size of Cd9(-/-)TG female mice was significantly reduced after their first birth. Severely delayed re-epithelialization of the endometrium was then occurred. Concomitantly, vascular endothelial growth factor (VEGF) was remarkably reduced in the uterine secretions of Cd9(-/-)TG female mice. These results provide the first evidence that CD9-mediated VEGF secretion plays a role in re-epithelialization of the uterus.

Secret key distillation from shielded two-qubit states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Joonwoo

The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key canmore » be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.« less

Steganography on multiple MP3 files using spread spectrum and Shamir's secret sharing

NASA Astrophysics Data System (ADS)

Yoeseph, N. M.; Purnomo, F. A.; Riasti, B. K.; Safiie, M. A.; Hidayat, T. N.

2016-11-01

The purpose of steganography is how to hide data into another media. In order to increase security of data, steganography technique is often combined with cryptography. The weakness of this combination technique is the data was centralized. Therefore, a steganography technique is develop by using combination of spread spectrum and secret sharing technique. In steganography with secret sharing, shares of data is created and hidden in several medium. Medium used to concealed shares were MP3 files. Hiding technique used was Spread Spectrum. Secret sharing scheme used was Shamir's Secret Sharing. The result showed that steganography with spread spectrum combined with Shamir's Secret Share using MP3 files as medium produce a technique that could hid data into several cover. To extract and reconstruct the data hidden in stego object, it is needed the amount of stego object which more or equal to its threshold. Furthermore, stego objects were imperceptible and robust.

Rhizonema sequoiae n.gen. n.sp. from Coast Redwood Sequoia sempervirens (D.Don) Endl.

PubMed Central

Del Prado Vera, I. Cid; Lownsbery, B. F.; Maggenti, A. R.

1983-01-01

Rhizonema sequoiae n.gen, u. sp. is described from the roots of Coast Redwood, Sequoia sempervirens (D. Don) Endl., growing near Lake Lagunitas, Marin County, California. Rhizonema females are annulated over their entire bodies, are wholly embedded in host tissue, and secrete an abundant amount of gel material. Mature females do not form a cyst. The vulva is located on a large posterior terminal cone, and the anus is on the dorsal vulval lip. Esophageal glands of the second-stage larvae fill more than half of the body cavity. Tails of the vermiform males are blunt, and a cloacal tubus is present. PMID:19295834

Parasympathetic Control of Airway Submucosal Glands: Central Reflexes and the Airway Intrinsic Nervous System

PubMed Central

Wine, Jeffrey J.

2007-01-01

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences of this for gland secretion and airway defense are poorly understood, but it is possible that interventions to modify submucosal gland secretion in transplanted lungs might have therapeutic consequences. Introduction and overviewProtecting the Airways: mucus and submucosal glands.The airway intrinsic nervous system: a special role in innate defense?Innate defense: prophylactic secretion and local responses.Acute ‘Emergency’ airway defense reflexesAirway receptors: Improved methods reveal greater diversityHijacking emergency defense for innate defense: receptor plasticity and airways sensitization.Conclusion: Implications for cystic fibrosis and lung transplantation. PMID:17350348

Assessment of sodium status in large ruminants by measuring the sodium-to-potassium ratio in muzzle secretions.

PubMed

Singh, S P; Rani, D

1999-09-01

To develop a simple diagnostic test to assess sodium status in large ruminants on the basis of the sodium-to-potassium ratio (Na:K) and to determine its relevance. 7 buffalo heifers and 21 lactating, pregnant, and nonpregnant dairy cows and heifers. Buffalo heifers were subjected in 2 experiments to variable dietary sodium intake or sodium depletion and changes in sodium and potassium concentrations; Na:K was simultaneously monitored in various body fluids to study its value for indicating sodium status. Validity of the muzzle secretion test was assessed. Muzzle secretion and urinary Na:K and sodium concentration, but not serum electrolyte concentrations, reflected the sodium status of buffalo heifers in response to the widely variable intake of sodium (0.03 to 0.16% of dry matter [DM]). Progressive sodium depletion during an 11-day period, using saliva deprivation caused reciprocal changes in sodium and potassium concentrations in saliva and muzzle secretion, but not in urine. Decreasing urine sodium concentration was associated with decreasing urine potassium concentration. Saliva, urine, and muzzle secretion Na:K closely reflected the degree of sodium deficit. Buffaloes or dairy cows maintained on optimal sodium intake had muzzle secretion and urine Na:K > 0.30. Muzzle secretion or urine Na:K < 0.20 or < 0.10, respectively, was indicative of sodium deficiency. Analysis of muzzle secretion Na:K, and to a large extent urine Na:K, may be used as a convenient diagnostic tool to assess sodium status in large ruminants. It has accuracy similar to that of saliva Na:K.

Production and characterization of two major Aspergillus oryzae secreted prolyl endopeptidases able to efficiently digest proline-rich peptides of gliadin.

PubMed

Eugster, Philippe J; Salamin, Karine; Grouzmann, Eric; Monod, Michel

2015-12-01

Prolyl endopeptidases are key enzymes in the digestion of proline-rich proteins. Fungal extracts rich in prolyl endopeptidases produced by a species such as Aspergillus oryzae used in food fermentation would be of particular interest for the development of an oral enzyme therapy product in patients affected by intolerance to gluten. Two major A. oryzae secreted prolyl endopeptidases of the MEROPS S28 peptidase family, AoS28A and AoS28B, were identified when this fungus was grown at acidic pH in a medium containing soy meal protein or wheat gliadin as the sole source of nitrogen. AoS28B was produced by 12 reference A. oryzae strains used in food fermentation. AoS28A was secreted by six of these 12 strains. This protease is the orthologue of the previously characterized Aspergillus fumigatus (AfuS28) and Aspergillus niger (AN-PEP) prolyl endopeptidases which are encoded by genes with a similar intron-exon structure. Large amounts of secreted AoS28A and AoS28B were obtained by gene overexpression in A. oryzae. AoS28A and AoS28B are endoproteases able to cleave N-terminally blocked proline substrates. Both enzymes very efficiently digested the proline-rich 33-mer of gliadin, the most representative immunotoxic peptide deriving from gliadin, with some differences in terms of specificity and optimal pH. Digestion of the gliadin peptide in short peptides with both enzymes was found to occur from its N terminus.

Detection and Measurement of Staphylococcal Enterotoxin-Like K (SEl-K) Secretion by Staphylococcus aureus Clinical Isolates

PubMed Central

Aguilar, Jorge L.; Varshney, Avanish K.; Wang, Xiaobo; Stanford, Lindsay; Scharff, Matthew

2014-01-01

Staphylococcal enterotoxin-like K (SEl-K) is a potent mitogen that elicits T-cell proliferation and cytokine production at very low concentrations. However, unlike the classical enterotoxins SEB and toxic shock syndrome toxin 1 (TSST-1), the gene for SEl-K is commonly present in more than half of all Staphylococcus aureus clinical isolates and is present in almost all USA300 community-acquired methicillin-resistant S. aureus (CA-MRSA) isolates. Sequencing of the sel-k gene in over 20 clinical isolates and comparative analysis with all 14 published sel-k sequences indicate that there are at least 6 variants of the sel-k gene, including one that is conserved among all examined USA300 strains. Additionally, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) that specifically detects and measures SEl-K protein in culture supernatants and biological fluids. Quantification of in vitro SEl-K secretion by various S. aureus isolates using this novel capture ELISA revealed detectable amounts of SEl-K secretion by all isolates, with the highest secretion levels being exhibited by MRSA strains that coexpress SEB. In vivo secretion was measured in a murine thigh abscess model, where similar levels of SEl-K accumulation were noted regardless of whether the infecting strain exhibited high or low secretion of SEl-K in vitro. We conclude that SEl-K is commonly expressed in the setting of staphylococcal infection, in significant amounts. SEl-K should be further explored as a target for passive immunotherapy against complicated S. aureus infection. PMID:24808237

Molecular Mechanism of Pancreatic and Salivary Glands Fluid and HCO3− Secretion

PubMed Central

Lee, Min Goo; Ohana, Ehud; Park, Hyun Woo; Yang, Dongki; Muallem, Shmuel

2013-01-01

Fluid and HCO3− secretion is a vital function of all epithelia and is required for the survival of the tissue. Aberrant fluid and HCO3− secretion is associated with many epithelial diseases, such as cystic fibrosis, pancreatitis, Sjögren’s syndrome and other epithelial inflammatory and autoimmune diseases. Significant progress has been made over the last 20 years in our understanding of epithelial fluid and HCO3− secretion, in particular by secretory glands. Fluid and HCO3− secretion by secretory glands is a two step process. Acinar cells secrete isotonic fluid in which the major salt is NaCl. Subsequently, the duct modifies the volume and electrolyte composition of the fluid to absorb the Cl− and secrete HCO3−. The relative volume secreted by acinar and duct cells and modification of electrolyte composition of the secreted fluids varies among secretory glands to meet their physiological functions. In the pancreas, acinar cells secrete small amount of NaCl-rich fluid, while the duct absorbs the Cl− and secretes HCO3− and the bulk of the fluid in the pancreatic juice. Fluid secretion appears to be driven by active HCO3− secretion. In the salivary glands, acinar cells secrete the bulk of the fluid in the saliva that contains high concentrations of Na+ and Cl− and fluid secretion is mediated by active Cl− secretion. The salivary glands duct absorbs both the Na+ and Cl− and secretes K+ and HCO3−. In this review, we focus on the molecular mechanism of fluid and HCO3− secretion by the pancreas and salivary glands, to highlight the similarities of the fundamental mechanisms of acinar and duct cell functions, and point the differences to meet glands specific secretions. PMID:22298651

Mutations in ppe38 block PE_PGRS secretion and increase virulence of Mycobacterium tuberculosis.

PubMed

Ates, Louis S; Dippenaar, Anzaan; Ummels, Roy; Piersma, Sander R; van der Woude, Aniek D; van der Kuij, Kim; Le Chevalier, Fabien; Mata-Espinosa, Dulce; Barrios-Payán, Jorge; Marquina-Castillo, Brenda; Guapillo, Carolina; Jiménez, Connie R; Pain, Arnab; Houben, Edith N G; Warren, Robin M; Brosch, Roland; Hernández-Pando, Rogelio; Bitter, Wilbert

2018-02-01

Mycobacterium tuberculosis requires a large number of secreted and exported proteins for its virulence, immune modulation and nutrient uptake. Most of these proteins are transported by the different type VII secretion systems 1,2 . The most recently evolved type VII secretion system, ESX-5, secretes dozens of substrates belonging to the PE and PPE families, which are named for conserved proline and glutamic acid residues close to the amino terminus 3,4 . However, the role of these proteins remains largely elusive 1 . Here, we show that mutations of ppe38 completely block the secretion of two large subsets of ESX-5 substrates, that is, PPE-MPTR and PE_PGRS, together comprising >80 proteins. Importantly, hypervirulent clinical M. tuberculosis strains of the Beijing lineage have such a mutation and a concomitant loss of secretion 5 . Restoration of PPE38-dependent secretion partially reverted the hypervirulence phenotype of a Beijing strain, and deletion of ppe38 in moderately virulent M. tuberculosis increased virulence. This indicates that these ESX-5 substrates have an important role in virulence attenuation. Phylogenetic analysis revealed that deletion of ppe38 occurred at the branching point of the 'modern' Beijing sublineage and is shared by Beijing outbreak strains worldwide, suggesting that this deletion may have contributed to their success and global distribution 6,7 .

Role of Carbohydrate in Glycoprotein Traffic and Secretion

DTIC Science & Technology

1988-01-01

synthesized in normal amounts but accumu- lated intracellularly, with transport to the cell surface being greatly de - layed. Glycoprotein E2 isolated from...UNcLA ,F E 2 Role of Carbohydrate in Glycoprotein Traffic and Secretion JAMES B. PARENT I. Introduction I!. Evidence for Intracellular Transport Signals...Ill. Oligosaccharide Biosynthesis IV. Role of Carbohydrate in Protein Solubility. Structure, and Stability V. Evidence for Carbohydrate Transport

Secretion of Ipa proteins by Shigella flexneri: inducer molecules and kinetics of activation.

PubMed Central

Bahrani, F K; Sansonetti, P J; Parsot, C

1997-01-01

The type III Mxi-Spa secretion machinery of Shigella flexneri is responsible for secretion of Ipa proteins, which are involved in the entry of bacteria into epithelial cells. Ipa proteins accumulate within bacteria growing in laboratory media, and their secretion is activated upon contact of bacteria with eukaryotic cells. In this study, we have identified a group of chemical compounds, including Congo red, Evans blue, and direct orange, which are able to induce secretion of Ipa proteins by bacteria suspended in phosphate-buffered saline. Parameters of kinetics of activation of Ipa secretion by Congo red were determined by measuring by enzyme-linked immunosorbent assay the amount of IpaC secreted and by investigating the increase in susceptibility of Ipa proteins to proteinase K degradation. Ipa secretion occurred at 37 degrees C, was obtained with 5 to 10 microM Congo red, and was complete within 30 min. In addition, activation of Ipa secretion by Congo red was observed with bacteria harvested throughout the exponential phase of growth but not with bacteria in the stationary phase. The interactions of Congo red and Congo red-related compounds with the Mxi-Spa secretion apparatus might be specific hydrophobic interactions similar to those involved in binding of Congo red to amyloid proteins. PMID:9316999

An Image Secret Sharing Method

DTIC Science & Technology

2006-07-01

the secret image in lossless manner and (2) any or fewer image shares cannot get sufficient information to reveal the ... secret image. It is an effective, reliable and secure method to prevent the secret image from being lost, stolen or corrupted. In comparison with...other image secret sharing methods, this approach’s advantages are its large compression rate on the size of the image shares, its strong protection of the secret image and its ability for real-time

The transforming growth factor-ss superfamily cytokine macrophage inhibitory cytokine-1 is present in high concentrations in the serum of pregnant women.

PubMed

Moore, A G; Brown, D A; Fairlie, W D; Bauskin, A R; Brown, P K; Munier, M L; Russell, P K; Salamonsen, L A; Wallace, E M; Breit, S N

2000-12-01

Macrophage inhibitory cytokine-1 (MIC-1) is a recently described divergent member of the transforming growth factor-ss superfamily. MIC-1 transcription up-regulation is associated with macrophage activation, and this observation led to its cloning. Northern blots indicate that MIC-1 is also present in human placenta. A sensitive sandwich enzyme-linked immunosorbent assay for the quantification of MIC-1 was developed and used to examine the role of this cytokine in pregnancy. High levels of MIC-1 are present in the sera of pregnant women. The level rises substantially with progress of gestation. MIC-1 can also be detected, in large amounts, in amniotic fluid and placental extracts. In addition, the BeWo placental trophoblastic cell line was found to constitutively express the MIC-1 transcript and secrete large amounts of MIC-1. These findings suggest that the placental trophoblast is a major source of the MIC-1 present in maternal serum and amniotic fluid. We suggest that MIC-1 may promote fetal survival by suppressing the production of maternally derived proinflammatory cytokines within the uterus.

Mast cells contribute to autoimmune diabetes by releasing interleukin-6 and failing to acquire a tolerogenic IL-10+ phenotype.

PubMed

Betto, Elena; Usuelli, Vera; Mandelli, Alessandra; Badami, Ester; Sorini, Chiara; Capolla, Sara; Danelli, Luca; Frossi, Barbara; Guarnotta, Carla; Ingrao, Sabrina; Tripodo, Claudio; Pucillo, Carlo; Gri, Giorgia; Falcone, Marika

2017-05-01

Mast cells (MCs) are innate immune cells that exert positive and negative immune modulatory functions capable to enhance or limit the intensity and/or duration of adaptive immune responses. Although MCs are crucial to regulate T cell immunity, their action in the pathogenesis of autoimmune diseases is still debated. Here we demonstrate that MCs play a crucial role in T1D pathogenesis so that their selective depletion in conditional MC knockout NOD mice protects them from the disease. MCs of diabetic NOD mice are overly inflammatory and secrete large amounts of IL-6 that favors differentiation of IL-17-secreting T cells at the site of autoimmunity. Moreover, while MCs of control mice acquire an IL-10+ phenotype upon interaction with FoxP3+ Treg cells, MCs of NOD mice do not undergo this tolerogenic differentiation. Our data indicate that overly inflammatory MCs unable to acquire a tolerogenic IL-10+ phenotype contribute to the pathogenesis of autoimmune T1D. Copyright © 2016 Elsevier Inc. All rights reserved.

The Inflammasome Drives GSDMD-Independent Secondary Pyroptosis and IL-1 Release in the Absence of Caspase-1 Protease Activity.

PubMed

Schneider, Katharina S; Groß, Christina J; Dreier, Roland F; Saller, Benedikt S; Mishra, Ritu; Gorka, Oliver; Heilig, Rosalie; Meunier, Etienne; Dick, Mathias S; Ćiković, Tamara; Sodenkamp, Jan; Médard, Guillaume; Naumann, Ronald; Ruland, Jürgen; Kuster, Bernhard; Broz, Petr; Groß, Olaf

2017-12-26

Inflammasomes activate the protease caspase-1, which cleaves interleukin-1β and interleukin-18 to generate the mature cytokines and controls their secretion and a form of inflammatory cell death called pyroptosis. By generating mice expressing enzymatically inactive caspase-1 C284A , we provide genetic evidence that caspase-1 protease activity is required for canonical IL-1 secretion, pyroptosis, and inflammasome-mediated immunity. In caspase-1-deficient cells, caspase-8 can be activated at the inflammasome. Using mice either lacking the pyroptosis effector gasdermin D (GSDMD) or expressing caspase-1 C284A , we found that GSDMD-dependent pyroptosis prevented caspase-8 activation at the inflammasome. In the absence of GSDMD-dependent pyroptosis, the inflammasome engaged a delayed, alternative form of lytic cell death that was accompanied by the release of large amounts of mature IL-1 and contributed to host protection. Features of this cell death modality distinguished it from apoptosis, suggesting it may represent a distinct form of pro-inflammatory regulated necrosis. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Human mesenchymal stromal cell-secreted lactate induces M2-macrophage differentiation by metabolic reprogramming

PubMed Central

Civini, Sara; Pacelli, Consiglia; Dieng, Mame Massar; Lemieux, William; Jin, Ping; Bazin, Renée; Patey, Natacha; Marincola, Francesco M.; Moldovan, Florina; Zaouter, Charlotte; Trudeau, Louis-Eric; Benabdhalla, Basma; Louis, Isabelle; Beauséjour, Christian; Stroncek, David; Le Deist, Françoise; Haddad, Elie

2016-01-01

Human mesenchymal stromal cells (MSC) have been shown to dampen immune response and promote tissue repair, but the underlying mechanisms are still under investigation. Herein, we demonstrate that umbilical cord-derived MSC (UC-MSC) alter the phenotype and function of monocyte-derived dendritic cells (DC) through lactate-mediated metabolic reprogramming. UC-MSC can secrete large quantities of lactate and, when present during monocyte-to-DC differentiation, induce instead the acquisition of M2-macrophage features in terms of morphology, surface markers, migratory properties and antigen presentation capacity. Microarray expression profiling indicates that UC-MSC modify the expression of metabolic-related genes and induce a M2-macrophage expression signature. Importantly, monocyte-derived DC obtained in presence of UC-MSC, polarize naïve allogeneic CD4+ T-cells into Th2 cells. Treatment of UC-MSC with an inhibitor of lactate dehydrogenase strongly decreases lactate concentration in culture supernatant and abrogates the effect on monocyte-to-DC differentiation. Metabolic analysis further revealed that UC-MSC decrease oxidative phosphorylation in differentiating monocytes while strongly increasing the spare respiratory capacity proportional to the amount of secreted lactate. Because both MSC and monocytes are recruited in vivo at the site of tissue damage and inflammation, we propose the local increase of lactate concentration induced by UC-MSC and the consequent enrichment in M2-macrophage generation as a mechanism to achieve immunomodulation. PMID:27070086

Secretory pattern of inhibin during estrous cycle and pregnancy in African (Loxodonta africana) and Asian (Elephas maximus) elephants.

PubMed

Yamamoto, Yuki; Yuto, Natsuki; Yamamoto, Tatsuya; Kaewmanee, Saroch; Shiina, Osamu; Mouri, Yasushi; Narushima, Etsuo; Katayanagi, Masayuki; Sugimura, Keisuke; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

2012-01-01

The ovary of female elephants has multiple corpora lutea (CL) during the estrous cycle and gestation. The previous reports clearly demonstrated that inhibin was secreted from lutein cells as well as granulosa cells of antral follicles in cyclic Asian elephants. The aim of this study is to investigate the inhibin secretion during the pregnancy in African and Asian elephants. Two African elephants and two Asian elephants were subjected to this study. Circulating levels of immunoreactive (ir-) inhibin and progesterone were measured by radioimmunoassay. Four pregnant periods of an African elephant and three pregnant periods of an Asian elephant were analyzed in this study. Circulating levels of ir-inhibin started to increase at 1 or 2 week before the ovulation and reached the peak level 3 or 4 weeks earlier than progesterone during the estrous cycle in both African and Asian elephants. After last luteal phase, the serum levels of ir-inhibin remained low throughout pregnancy in both an African and an Asian elephant. The mean levels of ir-inhibin during the pregnancy were lower than the luteal phase in the estrous cycle despite high progesterone levels were maintained throughout the pregnancy. These results strongly suggest that CL secrete a large amount of progesterone but not inhibin during the pregnancy in elephants. © 2011 Wiley Periodicals, Inc.

The extracellular matrix of the oleolytic biofilms of Marinobacter hydrocarbonoclasticus comprises cytoplasmic proteins and T2SS effectors that promote growth on hydrocarbons and lipids.

PubMed

Ennouri, Habiba; d'Abzac, Paul; Hakil, Florence; Branchu, Priscilla; Naïtali, Murielle; Lomenech, Anne-Marie; Oueslati, Ridha; Desbrières, Jacques; Sivadon, Pierre; Grimaud, Régis

2017-01-01

The assimilation of the nearly water insoluble substrates hydrocarbons and lipids by bacteria entails specific adaptations such as the formation of oleolytic biofilms. The present article reports that the extracellular matrix of an oleolytic biofilm formed by Marinobacter hydrocarbonoclasticus at n-hexadecane-water interfaces is largely composed of proteins typically cytoplasmic such as translation factors and chaperones, and a lesser amount of proteins of unknown function that are predicted extra-cytoplasmic. Matrix proteins appear to form a structured film on hydrophobic interfaces and were found mandatory for the development of biofilms on lipids, alkanes and polystyrene. Exo-proteins secreted through the type-2 secretion system (T2SS) were shown to be essential for the formation of oleolytic biofilms on both alkanes and triglycerides. The T2SS effector involved in biofilm formation on triglycerides was identified as a lipase. In the case of biofilm formation on n-hexadecane, the T2SS effector is likely involved in the mass transfer, capture or transport of alkanes. We propose that M. hydrocarbonoclasticus uses cytoplasmic proteins released by cell lysis to form a proteinaceous matrix and dedicated proteins secreted through the T2SS to act specifically in the assimilation pathways of hydrophobic substrates. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-06-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-03-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Absence of CD9 reduces endometrial VEGF secretion and impairs uterine repair after parturition

PubMed Central

Kawano, Natsuko; Miyado, Kenji; Yoshii, Noriko; Kanai, Seiya; Saito, Hidekazu; Miyado, Mami; Inagaki, Noboru; Odawara, Yasushi; Hamatani, Toshio; Umezawa, Akihiro

2014-01-01

In mammals, uterine epithelium is remodeled cyclically throughout adult life for pregnancy. Despite the expression of CD9 in the uterine epithelium, its role in maternal reproduction is unclear. Here, we addressed this issue by examining uterine secretions collected from patients undergoing fertility treatment and fertilization-competent Cd9−/− mice expressing CD9-GFP in their eggs (Cd9−/−TG). CD9 in uterine secretions was observed as extracellular matrix-like feature, and its amount of the secretions associated with repeated pregnancy failures. We also found that the litter size of Cd9−/−TG female mice was significantly reduced after their first birth. Severely delayed re-epithelialization of the endometrium was then occurred. Concomitantly, vascular endothelial growth factor (VEGF) was remarkably reduced in the uterine secretions of Cd9−/−TG female mice. These results provide the first evidence that CD9-mediated VEGF secretion plays a role in re-epithelialization of the uterus. PMID:24736431

Secreted production of Renilla luciferase in Bacillus subtilis.

PubMed

Chiang, Chung-Jen; Chen, Po Ting; Chao, Yun-Peng

2010-01-01

Luciferase (Rluc) from the soft coral Renilla reniformis has been widely used as a bioluminescent reporter, and its secreted production has been solely performed in mammalian cells thus far. To make the production more efficient, a series of approaches was attempted to overproduce Rluc extracellularly in Bacillus subtilis. First, Cys124 in the Rluc gene was substituted with Ala. The mutant gene was subsequently incorporated into a pUB110/R6K-based plasmid, consequently, fusing with the P43 promoter and the sacB signal peptide. With the nitrogen-rich medium, B. subtilis strain bearing the plasmid became able to secret a detectable amount of Rluc. Moreover, the secretion signal for the Rluc gene was replaced by the aprN leader peptide with or without the propeptide. The result led to a more than twofold increase in the secreted Rluc. Finally, by enhancing the transcription of the Rluc gene implementing the P43 and spac tandem promoter, it resulted in the secreted Rluc with a yield of 100 mg/L. Overall, this study illustrates a potential strategy for improving the secretion efficiency of heterologous proteins in B. subtilis.

Neonatal hyperthyroidism impairs epinephrine-provoked secretion of nerve growth factor and epidermal growth factor in mouse saliva.

PubMed

Lakshmanan, J; Landel, C P

1986-07-01

We examined long-term effects of neonatal hyperthyroidism on salivary secretions of nerve growth factor and epidermal growth factor in male and female mice at the age of 31 days. Hyperthyroidism was induced by thyroxine (T4) injections (0.4 microgram/g body weight/day) during days 0-6. Littermate control mice were treated with vehicle. T4 treatment did not alter the amounts of protein secreted into saliva but hormone administration induced alteration in the types of protein secreted. T4 treatment decreased the contents of both nerve growth factor and epidermal growth factor secreted into the saliva. A Sephadex G-200 column chromatographic profile revealed the presence of two distinct nerve growth factor immunoreactive peaks, while epidermal growth factor immunoreactivity predominantly eluted as a single low molecular weight form. T4 treatment did not alter the molecular nature of their secretion, but the treatment decreased their contents. These results indicate an impairment in salivary secretion of nerve growth factor and epidermal growth factor long after T4 treatment has been discontinued.

Secretive marsh aird species co-eccurrences and habitat associations across the midwest, USA

USGS Publications Warehouse

Bolenbaugh, Jason R.; Krementz, David G.; Lehnen, Sarah E.

2011-01-01

Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus, co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina) and open-water birds (pied-billed grebe Podilymbus podiceps, common moorhen Gallinula chloropus, and American coot Fulica americana; coots were only surveyed in 2009), co-occurred more often than expected by chance. These groupings were consistent between years. We then estimated the relation of these species and groups to landscape and local site characteristics by using zero-inflated abundance models that accounted for incomplete detection. At the landscape level (5-km radius), the amount of emergent herbaceous wetland was positively associated with least bittern occupancy, whereas the amount of woody wetland was negatively associated with least bittern, rail, and open-water bird occupancy. At the local level, habitat variables that were associated with abundance were not consistent among groups or between years, with the exception that both least bitterns and open-water birds had a strong positive association between abundance and water-vegetation interspersion. Land managers interested in marsh bird management or conservation may want to consider focusing efforts on landscapes with high amounts of emergent herbaceous wetland and low amounts of woody wetland, and managing for high amounts of water-vegetation interspersion within the wetland.

Proteases induce secretion of collagenase and plasminogen activator by fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werb, Z.; Aggeler, J.

1978-04-01

We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2 to 24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or ..cap alpha..-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16 to 48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10/sup 6/ cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continuedmore » presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, ..cap alpha../sub 1/-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.« less

Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants

PubMed Central

Yek, Sze Huei; Nash, David R.; Jensen, Annette B.; Boomsma, Jacobus J.

2012-01-01

Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi, we show that the ants adjust the amount of MG secretion to the virulence of the fungus with which they are infected. We further applied fixed volumes of MG secretion of ants challenged with constant conidia doses to agar mats of the same fungal species. This showed that inhibition halos were significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis-challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components, of which some are constitutive and others induced. PMID:22915672

Hormone supply of the organism in prolonged emotional stress

NASA Technical Reports Server (NTRS)

Amiragova, M. G.; Stulnikov, B. V.; Svirskaya, R. I.

1980-01-01

The effect of prolonged emotional stress of varying genesis on the hormonal function of the pancreas, thyroid gland, and adrenal cortex was studied. The amount of the hormonal secretion was found to depend on the type of adaptation activity and its duration. High secretion of the hormones observed outside the adaptation activity was examined as an index of the phase transition of defense reactions to the phase of overstress.

Cell stress increases ATP release in NLRP3 inflammasome-mediated autoinflammatory diseases, resulting in cytokine imbalance

PubMed Central

Carta, Sonia; Penco, Federica; Lavieri, Rosa; Martini, Alberto; Dinarello, Charles Anthony; Gattorno, Marco; Rubartelli, Anna

2015-01-01

Cell stress is implicated in triggering bouts of systemic inflammation in patients with autoinflammatory disorders. Blood monocytes from patients affected by NLRP3-mediated cryopyrin-associated periodic syndromes (CAPS) release greater amounts of IL-1β than monocytes from unaffected subjects. Here we show that stress lowers the threshold of activation; blood monocytes from CAPS patients maintain the high levels of secreted IL-1β (fivefold) and IL-18 (10-fold) when stimulated with 1,000-fold less LPS than that required for full IL-1β secretion in control subjects. Unexpectedly, IL-1α secretion is increased 10-fold, indicating that inflammatory episodes in CAPS may not be entirely a result of IL-1β but may also involve IL-1α. In CAPS monocytes, LPS induces the externalization of copious amounts of ATP (10-fold), which drive IL-1β, IL-18, and IL-1α release via activation of the P2X purinoceptor 7. This enhanced ATP release appears to be the link between cell stress and increased cytokine secretion in CAPS. In the later phase after LPS stimulation, CAPS monocytes undergo oxidative stress, which impairs production of the anti-inflammatory IL-1 receptor antagonist (IL-1Ra). Remarkably, IL-1Ra secretion is fully restored by treatment with antioxidants. In two patients with the same NLRP3 mutation, but different disease severity, monocytes from the mildly affected patient exhibited more efficient redox response, lower ATP secretion, and more balanced cytokine production. Thus, the robustness of the individual antioxidant response increases the tolerance to stress and reduces the negative effect of the disease. Pharmacologic block of P2X purinoceptor 7 and improved stress tolerance may represent novel treatment strategies in stress-associated inflammatory diseases. PMID:25730877

Secretion of Hepatitis C Virus Replication Intermediates Reduces Activation of Toll-Like Receptor 3 in Hepatocytes.

PubMed

Grünvogel, Oliver; Colasanti, Ombretta; Lee, Ji-Young; Klöss, Volker; Belouzard, Sandrine; Reustle, Anna; Esser-Nobis, Katharina; Hesebeck-Brinckmann, Jasper; Mutz, Pascal; Hoffmann, Katrin; Mehrabi, Arianeb; Koschny, Ronald; Vondran, Florian W R; Gotthardt, Daniel; Schnitzler, Paul; Neumann-Haefelin, Christoph; Thimme, Robert; Binder, Marco; Bartenschlager, Ralf; Dubuisson, Jean; Dalpke, Alexander H; Lohmann, Volker

2018-06-01

Hepatitis C virus (HCV) infections most often result in chronic outcomes, although the virus constantly produces replication intermediates, in particular double-stranded RNA (dsRNA), representing potent inducers of innate immunity. We aimed to characterize the fate of HCV dsRNA in hepatocyte cultures to identify mechanisms contributing to viral persistence in presence of an active innate immune response. We analyzed hepatocyte-based culture models for HCV for induction of innate immunity, secretion of virus positive- or negative-strand RNA, and viral replication using different quantification methods and microscopy techniques. Expression of pattern recognition receptors was reconstituted in hepatoma cells by lentiviral transduction. HCV-infected cells secrete substantial amounts of virus positive- and negative-strand RNAs in extracellular vesicles (EVs), toward the apical and basolateral domain of hepatocytes. Secretion of negative-strand RNA was independent from virus production, and viral RNA secreted in EVs contained higher relative amounts of negative-strands, indicating that mostly virus dsRNA is released. A substantial part of viral replication complexes and dsRNA was found in the endosomal compartment and multivesicular bodies, indicating that secretion of HCV replication intermediates is mediated by the exosomal pathway. Block of vesicle release in HCV-positive cells increased intracellular dsRNA levels and increased activation of toll-like receptor 3, inhibiting HCV replication. Using hepatocyte-based culture models for HCV, we found a portion of HCV dsRNA intermediates to be released from infected cells in EVs, which reduces activation of toll-like receptor 3. This represents a novel mechanism how HCV evades host immune responses, potentially contributing to viral persistence. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

THE SECRETION OF DIGESTIVE ENZYMES AND CAECAL SIZE ARE DETERMINED BY DIETARY PROTEIN IN THE CRICKET Gryllus bimaculatus.

PubMed

Woodring, Joseph; Weidlich, Sandy

2016-11-01

In Gryllus bimaculatus, the size of the caecum decreases in the latter half of each instar to a stable minimal size with a steady minimal rate of digestive enzyme secretion until feeding resumes after ecdysis. The higher the percent protein in the newly ingested food, the faster and larger the caecum grows, and as a consequent the higher the secretion rate of trypsin and amylase. When hard boiled eggs (40% protein) are eaten the caecum is 2× larger, the trypsin secretion is almost 3× greater, and amylase 2.5× greater then when fed the same amount of apples (1.5% protein). Only dietary protein increases amylase secretion, whereas dietary carbohydrates have no effect on amylase secretion. The minimal caecal size and secretion rate must be supported by utilization of hemolymph amino acids, but the growth of the caecum and increasing enzymes secretions after the molt depend upon an amino acid source in the lumen. This simple regulation of digestive enzyme secretion is ideal for animals that must stop feeding in order to molt. This basic control system does not preclude additional regulation mechanisms, such as prandal, which is also indicated for G. bimaculatus, or even paramonal regulation. © 2016 Wiley Periodicals, Inc.

Skimming behaviour and spreading potential of Stenus species and Dianous coerulescens (Coleoptera: Staphylinidae)

NASA Astrophysics Data System (ADS)

Lang, Carolin; Seifert, Karlheinz; Dettner, Konrad

2012-11-01

Rove beetles of the genus Stenus Latreille and the genus Dianous Leach possess pygidial glands containing a multifunctional secretion of piperidine and pyridine-derived alkaloids as well as several terpenes. One important character of this secretion is the spreading potential of its different compounds, stenusine, norstenusine, 3-(2-methyl-1-butenyl)pyridine, cicindeloine, α-pinene, 1,8-cineole and 6-methyl-5-heptene-2-one. The individual secretion composition enables the beetles to skim rapidly and far over the water surface, even when just a small amount of secretion is emitted. Ethological investigations of several Stenus species revealed that the skimming ability, skimming velocity and the skimming behaviour differ between the Stenus species. These differences can be linked to varied habitat claims and secretion saving mechanisms. By means of tensiometer measurements using the pendant drop method, the spreading pressure of all secretion constituents as well as some naturally identical beetle secretions on the water surface could be established. The compound 3-(2-methyl-1-butenyl)pyridine excelled stenusine believed to date to be mainly responsible for skimming relating to its surface activity. The naturally identical secretions are not subject to synergistic effects of the single compounds concerning the spreading potential. Furthermore, evolutionary aspects of the Steninae's pygidial gland secretion are discussed.

Cultured 3T3L1 adipocytes dispose of excess medium glucose as lactate under abundant oxygen availability

NASA Astrophysics Data System (ADS)

Sabater, David; Arriarán, Sofía; Romero, María Del Mar; Agnelli, Silvia; Remesar, Xavier; Fernández-López, José Antonio; Alemany, Marià

2014-01-01

White adipose tissue (WAT) produces lactate in significant amount from circulating glucose, especially in obesity;Under normoxia, 3T3L1 cells secrete large quantities of lactate to the medium, again at the expense of glucose and proportionally to its levels. Most of the glucose was converted to lactate with only part of it being used to synthesize fat. Cultured adipocytes were largely anaerobic, but this was not a Warburg-like process. It is speculated that the massive production of lactate, is a process of defense of the adipocyte, used to dispose of excess glucose. This way, the adipocyte exports glucose carbon (and reduces the problem of excess substrate availability) to the liver, but the process may be also a mechanism of short-term control of hyperglycemia. The in vivo data obtained from adipose tissue of male rats agree with this interpretation.

Diarrhoeal disease through enterocyte secretion: a doctrine untroubled by proof.

PubMed

Lucas, Michael L

2010-04-01

For almost 40 years, one of the principal causes of diarrhoeal disease has been thought to be fluid secretion emanating from the epithelial cells of the small and large intestine. Given the extremely large fluid losses seen in cholera, where secretion can be up to several litres per day, this seems a plausible hypothesis. The enterocyte (epithelial cell) secretion hypothesis rapidly displaced all other alternatives, such as vasodilatation coupled with enhanced paracellular permeability. An essential mechanism underlying enterocyte secretion has always been assumed to be electrogenic chloride secretion, leading to a localized osmotic imbalance at the mucosal surface of the enterocytes that causes fluid entry into the lumen by osmosis. The chloride secretion basis for enterotoxin-deranged secretion is assumed to be measurable by changes in electrical currents and by altered transport of chloride ion. These can be detected after the small intestine is exposed to a heat-stable enterotoxin (STa) produced by Escherichia coli. However, in vivo, when the recovered volume technique is used, STa is found not to be secretory. The heat-stable enterotoxin is therefore a test case toxin, because the complex techniques used to demonstrate enterocyte secretion after STa exposure show apparent secretion, while the simplest technique based on fluid recovery and genuinely measuring the mass transport of fluid does not. This review scrutinizes the nature of the evidence put forward for enterocyte secretion and reaches the conclusion that there is no evidence for it. Debilitating secretion undoubtedly does take place in severe diarrhoeal disease, but secretion from enterocytes is unlikely to be the cause.

The Role of Diet in Shaping the Chemical Signal Design of Lacertid Lizards.

PubMed

Baeckens, Simon; García-Roa, Roberto; Martín, José; Van Damme, Raoul

2017-09-01

Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall, diet appears a relatively poor predictor of interspecific differences in the broad chemical profiles of secretions of lacertid lizards.

High-performance compression and double cryptography based on compressive ghost imaging with the fast Fourier transform

NASA Astrophysics Data System (ADS)

Leihong, Zhang; Zilan, Pan; Luying, Wu; Xiuhua, Ma

2016-11-01

To solve the problem that large images can hardly be retrieved for stringent hardware restrictions and the security level is low, a method based on compressive ghost imaging (CGI) with Fast Fourier Transform (FFT) is proposed, named FFT-CGI. Initially, the information is encrypted by the sender with FFT, and the FFT-coded image is encrypted by the system of CGI with a secret key. Then the receiver decrypts the image with the aid of compressive sensing (CS) and FFT. Simulation results are given to verify the feasibility, security, and compression of the proposed encryption scheme. The experiment suggests the method can improve the quality of large images compared with conventional ghost imaging and achieve the imaging for large-sized images, further the amount of data transmitted largely reduced because of the combination of compressive sensing and FFT, and improve the security level of ghost images through ciphertext-only attack (COA), chosen-plaintext attack (CPA), and noise attack. This technique can be immediately applied to encryption and data storage with the advantages of high security, fast transmission, and high quality of reconstructed information.

Axonal transport and secretion of fibrillar forms of α-synuclein, Aβ42 peptide and HTTExon 1.

PubMed

Brahic, Michel; Bousset, Luc; Bieri, Gregor; Melki, Ronald; Gitler, Aaron D

2016-04-01

Accruing evidence suggests that prion-like behavior of fibrillar forms of α-synuclein, β-amyloid peptide and mutant huntingtin are responsible for the spread of the lesions that characterize Parkinson disease, Alzheimer disease and Huntington disease, respectively. It is unknown whether these distinct protein assemblies are transported within and between neurons by similar or distinct mechanisms. It is also unclear if neuronal death or injury is required for neuron-to-neuron transfer. To address these questions, we used mouse primary cortical neurons grown in microfluidic devices to measure the amounts of α-synuclein, Aβ42 and HTTExon1 fibrils transported by axons in both directions (anterograde and retrograde), as well as to examine the mechanism of their release from axons after anterograde transport. We observed that the three fibrils were transported in both anterograde and retrograde directions but with strikingly different efficiencies. The amount of Aβ42 fibrils transported was ten times higher than that of the other two fibrils. HTTExon1 was efficiently transported in the retrograde direction but only marginally in the anterograde direction. Finally, using neurons from two distinct mutant mouse strains whose axons are highly resistant to neurodegeneration (Wld(S) and Sarm1(-/-)), we found that the three different fibrils were secreted by axons after anterograde transport, in the absence of axonal lysis, indicating that trans-neuronal spread can occur in intact healthy neurons. In summary, fibrils of α-synuclein, Aβ42 and HTTExon1 are all transported in axons but in directions and amounts that are specific of each fibril. After anterograde transport, the three fibrils were secreted in the medium in the absence of axon lysis. Continuous secretion could play an important role in the spread of pathology between neurons but may be amenable to pharmacological intervention.

Assimilation of water and dietary ions by the gastrointestinal tract during digestion in seawater-acclimated rainbow trout.

PubMed

Bucking, Carol; Fitzpatrick, John L; Nadella, Sunita R; McGaw, Iain J; Wood, Chris M

2011-07-01

Recent studies focusing on the consequences of feeding for ion and water balance in freshwater fish have revealed the need for similar comparative studies in seawater fish. A detailed time course sampling of gastrointestinal (GI) tract contents following the ingestion of a single meal of a commercial diet revealed the assimilation of both water and dietary ions (Na(+), Cl(-), K(+), Ca(2+), Mg(2+)) along the GI tract of seawater-acclimated rainbow trout (Oncorhynchus mykiss) which had been fasted for 1 week. Consumption of the meal did not change the drinking rate. There was a large secretion of fluid into the anterior intestine and caecae (presumably bile and/or pancreatic secretions). As a result, net assimilation (63%) of the ingested water along the GI tract was lower than generally reported for fasted trout. Mg(2+) was neither secreted into nor absorbed from the GI tract on a net basis. Only K(+) (93% assimilated) and Ca(2+) (43% assimilated) were absorbed in amounts in excess of those provided by ingested seawater, suggesting that dietary sources of K(+) and Ca(2+) may be important to seawater teleosts. The oesophagus-stomach served as a major site of absorption for Na(+), Cl(-), K(+), Ca(2+), and Mg(2+), and the anterior intestine and caecae as a major site of net secretion for all of these ions, except Cl(-). Despite large absorptive fluxes of these ions, the ionic composition of the plasma was maintained during the digestion of the meal. The results of the present study were compared with previous work on freshwater-acclimated rainbow trout, highlighting some important differences, but also several similarities on the assimilation of water and ions along the gastrointestinal tract during digestion. This study highlights the complicated array of ion and water transport that occurs in the intestine during digestion while revealing the importance of dietary K(+) and Ca(2+) to seawater-acclimated rainbow trout. Additionally, this study reveals that digestion in seawater-acclimated rainbow trout appears to compromise intestinal water absorption.

Plant Glandular Trichomes: Natural Cell Factories of High Biotechnological Interest1[OPEN

PubMed Central

2017-01-01

Multicellular glandular trichomes are epidermal outgrowths characterized by the presence of a head made of cells that have the ability to secrete or store large quantities of specialized metabolites. Our understanding of the transcriptional control of glandular trichome initiation and development is still in its infancy. This review points to some central questions that need to be addressed to better understand how such specialized cell structures arise from the plant protodermis. A key and unique feature of glandular trichomes is their ability to synthesize and secrete large amounts, relative to their size, of a limited number of metabolites. As such, they qualify as true cell factories, making them interesting targets for metabolic engineering. In this review, recent advances regarding terpene metabolic engineering are highlighted, with a special focus on tobacco (Nicotiana tabacum). In particular, the choice of transcriptional promoters to drive transgene expression and the best ways to sink existing pools of terpene precursors are discussed. The bioavailability of existing pools of natural precursor molecules is a key parameter and is controlled by so-called cross talk between different biosynthetic pathways. As highlighted in this review, the exact nature and extent of such cross talk are only partially understood at present. In the future, awareness of, and detailed knowledge on, the biology of plant glandular trichome development and metabolism will generate new leads to tap the largely unexploited potential of glandular trichomes in plant resistance to pests and lead to the improved production of specialized metabolites with high industrial or pharmacological value. PMID:28724619

Effect of Parainfluenza-3 Neuraminidase on Bovine Nasal Secretion

PubMed Central

Morein, Bror; Bergman, Rune

1972-01-01

Three samples of bovine nasal secretion were each separated into a sol phase and a surface gel phase. In all samples, the gel phase contained an approximately four times greater amount of bound N-acetylneuraminic acid (NANA) than the sol phase. From the gel phase, bound NANA could be released by exposure to parainfluenza-3 virus neuraminidase. The surface gel appears to be a natural substrate for this enzyme. PMID:4347547

The Secret of Safety Lies in Danger.

ERIC Educational Resources Information Center

Wildavsky, Aaron

In creating and maintaining public safety, risks which entail some amount of danger are necessary. These risks must be rated regarding the amount of benefit and danger they would bring in order to ascertain the worthiness of the risk. It is important to realize that risks can often bring greater safety, that many safety devices themselves involve…

Maturation of hepatic lipase. Formation of functional enzyme in the endoplasmic reticulum is the rate-limiting step in its secretion.

PubMed

Ben-Zeev, Osnat; Doolittle, Mark H

2004-02-13

Among three lipases in the lipase gene family, hepatic lipase (HL), lipoprotein lipase, and pancreatic lipase, HL exhibits the lowest intracellular specific activity (i.e. minimal amounts of catalytic activity accompanied by massive amounts of inactive lipase mass in the endoplasmic reticulum (ER)). In addition, HL has a distinctive sedimentation profile, where the inactive mass overlaps the region containing active dimeric HL and trails into progressively larger molecular forms. Eventually, at least half of the HL inactive mass in the ER reaches an active, dimeric conformation (t(1/2) = 2 h) and is rapidly secreted. The remaining inactive mass is degraded. HL maturation occurs in the ER and is strongly dependent on binding to calnexin in the early co-/post-translational stages. Later stages of HL maturation occur without calnexin assistance, although inactive HL at all stages appears to be associated in distinct complexes with other ER proteins. Thus, unlike other lipases in the gene family, HL maturation is the rate-limiting step in its secretion as a functional enzyme.

Kyolic and Pycnogenol increase human growth hormone secretion in genetically-engineered keratinocytes.

PubMed

Buz'Zard, Amber R; Peng, Qiaoling; Lau, Benjamin H S

2002-02-01

The amount of human growth hormone (HGH) decreases significantly after the age of 30. This decrease has been implicated as one of the major causes in the signs of aging, such as thinning of the skin and bones, a decrease in lean muscle mass and an increase in adipose tissue. Supplementing the body's dwindling supply with recombinant human growth hormone (rHGH) has been shown to reverse the signs and symptoms of aging. However, drawbacks in rHGH replacement therapy include prohibitively high cost, the need for repeated injection and side effects such as carpel tunnel syndrome, gynecomastia and insulin resistance. The purpose of this study was to establish an in vitro model using genetically-engineered keratinocytes to screen natural compounds for the ability to stimulate HGH secretion. We now report that a combination of equal amounts of L-arginine and L-lysine, aged garlic extract (Kyolic), S-allyl cysteine and Pycnogenol significantly increased secretion of HGH in this in vitro model. The data indicate that this in vitro model may be used to screen for other secretagogues.

Release of Liposomal Contents by Cell-Secreted Matrix Metalloproteinase-9

PubMed Central

Banerjee, Jayati; Hanson, Andrea J.; Gadam, Bhushan; Elegbede, Adekunle I.; Tobwala, Shakila; Ganguly, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

2011-01-01

Liposomes have been widely used as a drug delivery vehicle and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately-formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes. PMID:19601658

Single cells from human primary colorectal tumors exhibit polyfunctional heterogeneity in secretions of ELR+ CXC chemokines.

PubMed

Adalsteinsson, Viktor A; Tahirova, Narmin; Tallapragada, Naren; Yao, Xiaosai; Campion, Liam; Angelini, Alessandro; Douce, Thomas B; Huang, Cindy; Bowman, Brittany; Williamson, Christina A; Kwon, Douglas S; Wittrup, K Dane; Love, J Christopher

2013-10-01

Cancer is an inflammatory disease of tissue that is largely influenced by the interactions between multiple cell types, secreted factors, and signal transduction pathways. While single-cell sequencing continues to refine our understanding of the clonotypic heterogeneity within tumors, the complex interplay between genetic variations and non-genetic factors ultimately affects therapeutic outcome. Much has been learned through bulk studies of secreted factors in the tumor microenvironment, but the secretory behavior of single cells has been largely uncharacterized. Here we directly profiled the secretions of ELR+ CXC chemokines from thousands of single colorectal tumor and stromal cells, using an array of subnanoliter wells and a technique called microengraving to characterize both the rates of secretion of several factors at once and the numbers of cells secreting each chemokine. The ELR+ CXC chemokines are highly redundant, pro-angiogenic cytokines that signal via the CXCR1 and CXCR2 receptors, influencing tumor growth and progression. We find that human primary colorectal tumor and stromal cells exhibit polyfunctional heterogeneity in the combinations and magnitudes of secretions for these chemokines. In cell lines, we observe similar variance: phenotypes observed in bulk can be largely absent among the majority of single cells, and discordances exist between secretory states measured and gene expression for these chemokines among single cells. Together, these measures suggest secretory states among tumor cells are complex and can evolve dynamically. Most importantly, this study reveals new insight into the intratumoral phenotypic heterogeneity of human primary tumors.

A Study on the Gastrointestinal Hormones and the Gastric Acid Secretion during Physical Stress in Man,

DTIC Science & Technology

1983-12-15

meal and oral glucose during prolonged severe exercise, caloric deficit and sleep deprivation 43 Paper II Secretin - a new stress hormone? 49 8 Page...secretion (gastrin), and that are influenced by the amount of gastric acid produced (secretin, group I pepsinogens). Our subjects were in caloric deficit...response to a liquid meal and oral glucose during prolonged severe exercise, caloric deficit, and sleep deprivation. O Oektedalen, 0 Flaten, P K Opstad

Platelets from patients with the Quebec platelet disorder contain and secrete abnormal amounts of urokinase-type plasminogen activator.

PubMed

Kahr, W H; Zheng, S; Sheth, P M; Pai, M; Cowie, A; Bouchard, M; Podor, T J; Rivard, G E; Hayward, C P

2001-07-15

The Quebec platelet disorder (QPD) is an autosomal dominant platelet disorder associated with delayed bleeding and alpha-granule protein degradation. The degradation of alpha-granule, but not plasma, fibrinogen in patients with the QPD led to the investigation of their platelets for a protease defect. Unlike normal platelets, QPD platelets contained large amounts of fibrinolytic serine proteases that had properties of plasminogen activators. Western blot analysis, zymography, and immunodepletion experiments indicated this was because QPD platelets contained large amounts of urokinase-type plasminogen activator (u-PA) within a secretory compartment. u-PA antigen was not increased in all QPD plasmas, whereas it was increased more than 100-fold in QPD platelets (P <.00009), which contained increased u-PA messenger RNA. Although QPD platelets contained 2-fold more plasminogen activator inhibitor 1 (PAI-1) (P <.0008) and 100-fold greater u-PA-PAI-1 complexes (P <.0002) than normal platelets, they contained excess u-PA activity, predominantly in the form of two chain (tcu-PA), which required additional PAI-1 for full inhibition. There was associated proteolysis of plasminogen in QPD platelets, to forms that comigrated with plasmin. When similar amounts of tcu-PA were incubated with normal platelet secretory proteins, many alpha-granule proteins were proteolyzed to forms that resembled degraded QPD platelet proteins. These data implicate u-PA in the pathogenesis of alpha-granule protein degradation in the QPD. Although patients with the QPD have normal to increased u-PA levels in their plasma, without evidence of systemic fibrinogenolysis, their increased platelet u-PA could contribute to bleeding by accelerating fibrinolysis within the hemostatic plug. QPD is the only inherited bleeding disorder in humans known to be associated with increased u-PA.

Quantitative visualization of synchronized insulin secretion from 3D-cultured cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Takahiro; Kanamori, Takao; Inouye, Satoshi

Quantitative visualization of synchronized insulin secretion was performed in an isolated rat pancreatic islet and a spheroid of rat pancreatic beta cell line using a method of video-rate bioluminescence imaging. Video-rate images of insulin secretion from 3D-cultured cells were obtained by expressing the fusion protein of insulin and Gaussia luciferase (Insulin-GLase). A subclonal rat INS-1E cell line stably expressing Insulin-GLase, named iGL, was established and a cluster of iGL cells showed oscillatory insulin secretion that was completely synchronized in response to high glucose. Furthermore, we demonstrated the effect of an antidiabetic drug, glibenclamide, on synchronized insulin secretion from 2D- andmore » 3D-cultured iGL cells. The amount of secreted Insulin-GLase from iGL cells was also determined by a luminometer. Thus, our bioluminescence imaging method could generally be used for investigating protein secretion from living 3D-cultured cells. In addition, iGL cell line would be valuable for evaluating antidiabetic drugs. - Highlights: • An imaging method for protein secretion from 3D-cultured cells was established. • The fused protein of insulin to GLase, Insulin-GLase, was used as a reporter. • Synchronous insulin secretion was visualized in rat islets and spheroidal beta cells. • A rat beta cell line stably expressing Insulin-GLase, named iGL, was established. • Effect of an antidiabetic drug on insulin secretion was visualized in iGL cells.« less

Loss of Cln3 impacts protein secretion in the social amoeba Dictyostelium.

PubMed

Huber, Robert J

2017-07-01

Neuronal ceroid lipofuscinosis (NCL), also referred to as Batten disease, is the most common form of childhood neurodegeneration. Mutations in CLN3 cause the most prevalent subtype of the disease, which manifests during early childhood and is currently untreatable. The precise function of the CLN3 protein is still not known, which has inhibited the development of targeted therapies. In the social amoeba Dictyostelium discoideum, loss of the CLN3 homolog, Cln3, reduces adhesion during early development, which delays streaming and aggregation. The results of the present study indicate that this phenotype may be at least partly due to aberrant protein secretion in cln3 - cells. It is well-established that Cln3 localizes primarily to the contractile vacuole (CV) system in Dictyostelium, and to a lesser extent, compartments of the endocytic pathway. Intriguingly, the CV system has been linked to the secretion of proteins that do not contain a signal peptide for secretion (i.e., unconventional protein secretion). Proteins that do contain a signal peptide are secreted via a conventional mechanism involving the endoplasmic reticulum, transport through the Golgi, and secretion via vesicle release. In this study, Cln3 was observed to co-localize with the Golgi marker wheat germ agglutinin suggesting that Cln3 participates in both secretion mechanisms. Chimeras of wild-type (WT) and cln3 - cells displayed delayed streaming and aggregation, and interestingly, cln3 - cells starved in conditioned media (CM) harvested from starving WT cells showed near normal timing of streaming and aggregation suggesting aberrant protein secretion in Cln3-deficient cells. Based on these observations, LC-MS/MS was used to reveal the protein content of CM from starved cells (mass spectrometry data are available via ProteomeXchange with identifier PXD004897). A total of 450 proteins were detected in WT and cln3 - CM, of which 3 were absent in cln3 - CM. Moreover, 12 proteins that were present in cln3 - CM were absent in WT CM. Label-free quantification identified 42 proteins that were present in significantly higher amounts in cln3 - CM compared to WT, and 3 proteins that were present in significantly reduced amounts. A GO term enrichment analysis showed that a majority of the affected proteins are linked to endocytosis, vesicle-mediated transport, proteolysis, and metabolism. In total, the results of this study indicate that Cln3 functions in both conventional and unconventional protein secretion and that loss of Cln3 results in deregulated secretion during early development. Importantly, this is the first evidence in any system linking CLN3 function to protein secretion. Copyright © 2017 Elsevier Inc. All rights reserved.

In Vitro Mineralization by Preosteoblasts in Poly(D, L-lactide-co-glycolide) Inverse Opal Scaffolds Reinforced with Hydroxyapatite Nanoparticles

PubMed Central

Choi, Sung-Wook; Zhang, Yu; Thomopoulos, Stavros; Xia, Younan

2010-01-01

Inverse opal scaffolds made of poly(D, L-lactide-co-glycolide) (PLGA) and hydroxyapatite (HAp) were fabricated using cubic-closed packed (ccp) lattices of uniform gelatin microspheres as templates and evaluated for bone tissue engineering. The scaffolds exhibited a uniform pore size (213 ± 4.4 μm), a porosity of ∼75%, and an excellent connectivity in three dimensions. Three different formulations were examined: pure PLGA, HAp-impregnated PLGA (PLGA/HAp), and apatite (Ap)-coated PLGA/HAp. After seeding with preosteoblasts (MC3T3-E1), the samples were cultured for different periods of time and then characterized by X-ray microcomputed tomography (micro-CT) and scanning electron microscopy to evaluate osteoinductivity in terms of the amount and spatial distribution of mineral secreted from the differentiated preosteoblasts. Our results indicate that preosteoblasts cultured in the Ap-coated PLGA/HAp scaffolds secreted the largest amount of mineral, which was also homogeneously distributed throughout the scaffolds. In contrast, the cells in the pure PLGA scaffolds secreted very little mineral, which was mainly deposited around the perimeter of the scaffolds. These results suggest that the uniform pore structure and favorable surface properties could facilitate the uniform secretion of extracellular matrix from cells throughout the scaffold. The Ap-coated PLGA/HAp scaffold with uniform pore structure could be a promising material for bone tissue engineering. PMID:20450216

Can Victoria's Secret Change the Future? A Subjective Time Perception Account of Sexual-Cue Effects on Impatience

ERIC Educational Resources Information Center

Kim, B. Kyu; Zauberman, Gal

2013-01-01

Sexual cues influence decisions not only about sex, but also about unrelated outcomes such as money. In the presence of sexual cues, individuals are more "impatient" when making intertemporal monetary tradeoffs, choosing smaller immediate amounts over larger delayed amounts. Previous research has emphasized the power of sexual cues to induce a…

Transient Expression of Chimeric Fluorescent Reporter Proteins in Pollen Tubes to Study Protein Polar Secretion and Dynamics.

PubMed

Zhong, Guitao; Liu, Ronghe; Zhuang, Menglong; Wang, Hao

2017-01-01

Transient expression of chimeric fluorescent reporter proteins by biolistic bombardment is a quick and useful procedure for studying subcellular protein localization and dynamics in plants. It is especially beneficial in specific plant cells which are not suitable for protoplast-based and Agrobacterium-mediated protein transient expression. Polar protein secretion and vesicular trafficking play essential functions for cell polarization and tip growth. The growing pollen tube is regarded as an ideal model plant cell system to study the machinery and regulation of polar protein trafficking and targeting. A large amount of newly synthesized proteins are packed and polarly transported to the apical region to support the rapid and highly polarized tip growth. Here, we described a detailed step-by-step protocol for the transient expression of chimeric fluorescent reporter proteins in growing Arabidopsis and tobacco pollen tubes to study polar transportation logistics and mechanisms. In addition, we have optimized the Arabidopsis and tobacco in vitro pollen germination medium and the conditions to maximize the efficiency of protein expression. As a proof of concept, we have used this protocol to express actin microfilament and late endosomal fluorescent markers in Arabidopsis and tobacco pollen tubes.

Mucilage processing and secretion in the green alga closterium. I. Cytology and biochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domozych, C.R.; Plante, K.; Blais, P.

1993-10-01

Placoderm desmids (Conjugales, Chlorophyta) such as Closterium exhibit a gliding locomotory behavior. This results from the forceful extrusion of an acidic polysaccharide from one pole of the cell causing the cell to glide in the opposite direction. A biochemical and cytological analysis of gliding behavior was performed. The mucilage is a high molecular weight polysaccharide rich in glucuronic acid and fucose. Under normal growth conditions, 3 [mu]g of mucilage is produced per cell in 30 days. Mucilage production increased 3-4 fold in cells challenged with low phosphate or nitrate conditions. A polyclonal antibody was raised against the mucilage and usedmore » in immunofluorescence studies. These results show that upon contact with another object Closterium aligns itself parallel to that object by a [open quotes]jack-knife[close quotes] motion. Subsequently, large amounts of mucilage are released to form elongate tubes enmeshing the cell with that object. In post-cytokinetic phases of the cell cycle, mucilage is extruded only through the pole of the developing semi-cell. Chlorotetracyclene-labeling of mucilage-secreting cells show a correlation between calcium-rich loci on the cell surface and sites of mucilage release. 20 refs., 25 figs., 1 tab.« less

Acute carbon tetrachloride feeding induces damage of large but not small cholangiocytes from BDL rat liver.

PubMed

LeSage, G D; Glaser, S S; Marucci, L; Benedetti, A; Phinizy, J L; Rodgers, R; Caligiuri, A; Papa, E; Tretjak, Z; Jezequel, A M; Holcomb, L A; Alpini, G

1999-05-01

Bile duct damage and/or loss is limited to a range of duct sizes in cholangiopathies. We tested the hypothesis that CCl4 damages only large ducts. CCl4 or mineral oil was given to bile duct-ligated (BDL) rats, and 1, 2, and 7 days later small and large cholangiocytes were purified and evaluated for apoptosis, proliferation, and secretion. In situ, we measured apoptosis by morphometric and TUNEL analysis and the number of small and large ducts by morphometry. Two days after CCl4 administration, we found an increased number of small ducts and reduced number of large ducts. In vitro apoptosis was observed only in large cholangiocytes, and this was accompanied by loss of proliferation and secretion in large cholangiocytes and loss of choleretic effect of secretin. Small cholangiocytes de novo express the secretin receptor gene and secretin-induced cAMP response. Consistent with damage of large ducts, we detected cytochrome P-4502E1 (which CCl4 converts to its radicals) only in large cholangiocytes. CCl4 induces selective apoptosis of large ducts associated with loss of large cholangiocyte proliferation and secretion.

Skin secretion peptides: the molecular facet of the deimatic behavior of the four-eyed frog, Physalaemus nattereri (Anura, Leptodactylidae).

PubMed

Barbosa, Eder Alves; Iembo, Tatiane; Martins, Graciella Ribeiro; Silva, Luciano Paulino; Prates, Maura Vianna; Andrade, Alan Carvalho; Bloch, Carlos

2015-11-15

Amphibians can produce a large amount of bioactive peptides over the skin. In order to map the precise tissue localization of these compounds and evaluate their functions, mass spectrometry imaging (MSI) and gene expression studies were used to investigate a possible correlation between molecules involved in the antimicrobial defense mechanisms and anti-predatory behavior by Physalaemus nattereri. Total skin secretion of P. nattereri was analyzed by classical Protein Chemistry and proteomic techniques. Intact inguinal macroglands were dissected from the rest of the skin and both tissues were analyzed by MSI and real-time polymerase chain reaction (RT-PCR) experiments. Peptides were primarily identified by de novo sequencing, automatic Edman degradation and cDNA data. Fifteen bradykinin (BK)-related peptides and two antimicrobial peptides were sequenced and mapped by MSI on the inguinal macrogland and the rest of P. nattereri skin. RT-PCR results revealed that BK-related peptide levels of expression were about 30,000 times higher on the inguinal macroglands than on the any other region of the skin, whilst antimicrobial peptide ions appear to be evenly distributed in both investigated regions. The presence of antimicrobial peptides in all investigated tissue regions is in accordance with the defensive role against microorganisms thoroughly demonstrated in the literature, whereas BK-related molecules are largely found on the inguinal macroglands suggesting an intriguing link between their noxious activities against potential predators of P. nattereri and the frog's deimatic behavior. Copyright © 2015 John Wiley & Sons, Ltd.

Inhibition of gastric secretion in treatment of pancreatic insufficiency.

PubMed Central

Saunders, J H; Drummond, S; Wormsley, K G

1977-01-01

The content of pancreatic enzymes in the duodenum was studied in two patients with pancreatic achylia after a standard meal supplemented with commercial pancreatic extract. Gastric transit of the enzymes, with appearance of near-normal amounts in the duodenal contents, occurred only after inhibition of gastric secretion and buffering of residual gastric acid with antacids. Gastric inhibition and neutralisation of acid are therefore necessary for the satisfactory treatment of patients with pancreatic exocrine insufficiency but normal gastric function. PMID:13906

In vitro steroid secretion by staged spermatocysts (Sertoli/germ cell units) of dogfish (Squalus acanthias) testis.

PubMed

Cuevas, M E; Callard, G

1992-10-01

Using the dogfish shark (Squalus acanthias) testis model in which different germ cell stages are topographically separated, we previously observed that steroidogenic enzyme activities vary qualitatively and quantitatively during spermatogenesis. To determine whether these data, obtained by radiolabeled tracer analysis of testicular microsomes, accurately predict steroid secretion by intact cultured spermatocysts (germ cell/Sertoli cell units), steroids were radioimmunoassayed directly in spent medium. Steroid output in basal medium was low, but after addition of 25-hydroxycholesterol (25-OH chol, 60 microM), large amounts of progestins (P) and testosterone (T) accumulated. Dehydroepiandrosterone (DHEA), androstenedione (A), and estradiol (E2) were low or nondetectable in the presence or absence of 25-OH chol; however, addition of T (1 microM) as substrate elevated E2 above assay limits. T and P contents of media increased progressively over a 24-hr culture period (Day 1). Replacement and analysis of spent media at 24-hr intervals indicated that secretion was continuous up to 6 days after seeding, although secretory rates (T plus P) and T/P ratios changed with time in culture. Spermatocysts in premeiotic (PrM), meiotic (M), and post-meiotic (PoM) stages all secreted T and P; however, absolute values, T/P ratios, and stage-dependent patterns varied from one experiment to another with no obvious seasonal pattern. Also steroid secretion by staged cysts did not consistently agree with predictions based on steroidogenic enzyme activities measured in earlier cell-free assays, whether or not 25-OH chol was present. This discrepancy was not explained by stage-related patterns of steroid secretion vs retention or by addition of putative in vivo regulators. Agents that elevated P and/or T were dibutyryl cyclic AMP, 1-isobutyl-3-methylxanthine (IBMX), and forskolin, whereas ventral lobe extract and Ca2+ ionophore (A23817) were inhibitory. An autoregulatory feedback loop was indicated by a negative relationship between cyst concentration per well and steroid secretion rate. In contrast to T and P, E2 secretion in the presence of substrate (T, 1 microM) was as predicted from previously determined patterns of aromatase activity (M > PrM > PoM) and increased in response to IBMX. Added [3H]P, [3H]T and [3H]E2 all were extensively metabolized to polar products and P metabolism was stage related (PoM > M > PrM). These data indicate that analysis of free P, T, and E2 in static cyst cultures may underestimate true steroidogenic potential. Assuming further characterization of the system, we conclude that cultured spermatocysts from dogfish testis have potential for studying the multifactorial regulation of steroid synthesis and secretion stage-by-stage during spermatogenesis.

[Intragastric utilization of antacids following meals in relation to stomach emptying].

PubMed

Lux, G; Hartog, C; Ruppin, H; Lederer, P; Schmitt, W

1983-03-01

Gastric acid secretion and gastric emptying rate was measured using double marker method and continuous titration of a liquid peptone test meal. Titration rate was significantly reduced by 30 ml of an aluminiumhydroxide- and magnesiumhydroxide containing antacid compound (Maalox). Acidity of gastric contents was reduced over a period of 48.4 +/- 9.1 min (mean +/- SD; endpoint of titration pH 5.5) and 77.6 +/- 2.0 min (pH 3.5) (p less than 0.05). The histamine H2-receptor blocker Ranitidine (0.25 mg/kg b.w.) and the antimuscarinic agent Pirenzepine reduced titrable gastric acid secretion in a similar range, as far as the observation period of 90 min is concerned. Biosorbin MCT, a formula diet, stimulated gastric acid secretion half the amount of gastric acid secretion stimulated by the peptone meal. Gastric emptying rate was significantly reduced by formula diet, but not by either of the other compounds.

Antisense RNA to the first N-glycosylation gene, ALG7, inhibits protein N-glycosylation and secretion by Xenopus oocytes.

PubMed

Kukuruzinska, M A; Apekin, V; Lamkin, M S; Hiltz, A; Rodriguez, A; Lin, C C; Paz, M A; Oppenheim, F G

1994-02-15

N-Glycosylation has been shown to affect the rate of glycoprotein transport through the secretory pathway. In order to identify the critical components in the N-glycosylation pathway that directly influence protein secretion, we have studied the effects of downregulation of the first gene in the dolichol pathway, ALG7, on the synthesis, glycosylation and secretion of native and heterologous proteins by Xenopus laevis oocytes. Our strategy involved the use of ALG7 antisense RNA (asRNA) to lower the effective abundance of the ALG7 protein in oocytes. The results showed that there was an inverse dose-response relationship between ALG7 asRNA and the amount of glycosylated and secreted proteins. These effects were also observed for heterologously expressed rat parotid amylase. Since ALG7 asRNA did not inhibit overall protein synthesis, we conclude that downregulation of ALG7 expression directly lowered protein export.

Regulation of Lipid Droplet Size in Mammary Epithelial Cells by Remodeling of Membrane Lipid Composition—A Potential Mechanism

PubMed Central

Cohen, Bat-Chen; Shamay, Avi; Argov-Argaman, Nurit

2015-01-01

Milk fat globule size is determined by the size of its precursors—intracellular lipid droplets—and is tightly associated with its composition. We examined the relationship between phospholipid composition of mammary epithelial cells and the size of both intracellular and secreted milk fat globules. Primary culture of mammary epithelial cells was cultured in medium without free fatty acids (control) or with 0.1 mM free capric, palmitic or oleic acid for 24 h. The amount and composition of the cellular lipids and the size of the lipid droplets were determined in the cells and medium. Mitochondrial quantity and expression levels of genes associated with mitochondrial biogenesis and polar lipid composition were determined. Cells cultured with oleic and palmitic acids contained similar quantities of triglycerides, 3.1- and 3.8-fold higher than in controls, respectively (P < 0.0001). When cultured with oleic acid, 22% of the cells contained large lipid droplets (>3 μm) and phosphatidylethanolamine concentration was higher by 23 and 63% compared with that in the control and palmitic acid treatments, respectively (P < 0.0001). In the presence of palmitic acid, only 4% of the cells contained large lipid droplets and the membrane phosphatidylcholine concentration was 22% and 16% higher than that in the control and oleic acid treatments, respectively (P < 0.0001). In the oleic acid treatment, approximately 40% of the lipid droplets were larger than 5 μm whereas in that of the palmitic acid treatment, only 16% of the droplets were in this size range. Triglyceride secretion in the oleic acid treatment was 2- and 12-fold higher compared with that in the palmitic acid and control treatments, respectively. Results imply that membrane composition of bovine mammary epithelial cells plays a role in controlling intracellular and secreted lipid droplets size, and that this process is not associated with cellular triglyceride content. PMID:25756421

Comparison of secretory signal peptides for heterologous protein expression in microalgae: Expanding the secretion portfolio for Chlamydomonas reinhardtii

PubMed Central

de Carvalho, João Carlos Monteiro; Mayfield, Stephen Patrick

2018-01-01

Efficient protein secretion is a desirable trait for any recombinant protein expression system, together with simple, low-cost, and defined media, such as the typical media used for photosynthetic cultures of microalgae. However, low titers of secreted heterologous proteins are usually obtained, even with the most extensively studied microalga Chlamydomonas reinhardtii, preventing their industrial application. In this study, we aimed to expand and evaluate secretory signal peptides (SP) for heterologous protein secretion in C. reinhardtii by comparing previously described SP with untested sequences. We compared the SPs from arylsulfatase 1 and carbonic anhydrase 1, with those of untried SPs from binding protein 1, an ice-binding protein, and six sequences identified in silico. We identified over 2000 unique SPs using the SignalP 4.0 software. mCherry fluorescence was used to compare the protein secretion of up to 96 colonies for each construct, non-secretion construct, and parental wild-type cc1690 cells. Supernatant fluorescence varied according to the SP used, with a 10-fold difference observed between the highest and lowest secretors. Moreover, two SPs identified in silico secreted the highest amount of mCherry. Our results demonstrate that the SP should be carefully selected and that efficient sequences can be coded in the C. reinhardtii genome. The SPs described here expand the portfolio available for research on heterologous protein secretion and for biomanufacturing applications. PMID:29408937

Effect of OPC-12759 on EGF receptor activation, p44/p42 MAPK activity, and secretion in conjunctival goblet cells.

PubMed

Ríos, J David; Shatos, Marie A; Urashima, Hiroki; Dartt, Darlene A

2008-04-01

The purpose of the study was to determine if OPC-12759 stimulates secretion from conjunctival goblet cells in culture and if it activates the EGF receptor (EGFR) and p44/p42 mitogen-activated protein kinase (MAPK) to cause mucin secretion. Conjunctival goblet cells were cultured from pieces of male rat conjunctiva. OPC-12759 was added at increasing concentrations and for varying times to the cultured cells. The cholinergic agonist carbachol was used as a positive control. In selected experiments an inhibitor of the EGFR, AG1478, or an inhibitor of the kinase that activates MAPK, U0126, were added before OPC-12759. Goblet cell secretion of high molecular weight glycoconjugates was measured by an enzyme-linked lectin assay using the lectin UEA-1. Activation of the EGFR and MAPK were determined with Western blotting analysis using antibodies specific to the phosphorylated and the total amounts of these proteins. We found that OPC-12759 induced goblet cell secretion in a time- and concentration-dependent manner. Inhibition of the EGFR with AG1478 blocked secretion stimulated by OPC-12759. Inhibition of MAPK with U0126 also blocked secretion stimulated by OPC-12759. OPC-12759 increased the phosphorylation of the EGFR and MAPK in a time-dependent manner. We concluded that OPC-12759 stimulates secretion from cultured conjunctival goblet cells by activating the EGFR, which then induces MAPK activity.

Role of carbonic anhydrase in basal and stimulated bicarbonate secretion by the guinea pig duodenum.

PubMed

Muallem, R; Reimer, R; Odes, H S; Schwenk, M; Beil, W; Sewing, K F

1994-05-01

The role of carbonic anhydrase in the process of proximal duodenal mucosal bicarbonate secretion was investigated in the guinea pig. In a series of experiments in vivo, the duodenum was perfused with 24 mmol/liter NaHCO3 solution (+ NaCl for isotonicity) to ensure that active duodenal HCO3- secretion against a concentration gradient was measured. Acetazolamide (80 mg/kg) was infused intravenously to examine the role of carbonic anhydrase on basal and agonist-stimulated HCO3- secretion. Acetazolamide abolished basal HCO3- secretion and significantly decreased HCO3- secretion after stimulation with dibutyryl 5'-cyclic adenosine monophosphate (dBcAMP, 10(-5) mol/kg), dibutyryl 5'-cyclic guanosine monophosphate (dBcGMP, 10(-5) mol/kg), prostaglandin E2 (PGE2, 10(-6) mol/kg), PGF2 alpha (10(-6) mol/kg), tetradecanoyl-phorbol-acetate (TPA, 10(-7) mol/kg), glucagon (10(-7) mol/kg), vasoactive intestinal polypeptide (VIP, 10(-8) mol/kg), and carbachol (10(-8) mol/kg). Utilizing a fluorescence technique, we could detect the enzyme carbonic anhydrase in equal amounts in villous and crypt cells of the proximal duodenal epithelium; no activity was demonstrated in tissues pretreated with acetazolamide. In conclusion, carbonic anhydrase is required for both basal and stimulated duodenal HCO3- secretion.

Vitamin E Supplementation Increases the Attractiveness of Males' Scent for Female European Green Lizards

PubMed Central

Kopena, Renáta; Martín, José; López, Pilar; Herczeg, Gábor

2011-01-01

Background In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown. Methodology/Principal Findings Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger. Conclusions/Significance Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals. PMID:21552540

Heat Shock Protein HSP27 Secretion by Ovarian Cancer Cells Is Linked to Intracellular Expression Levels, Occurs Independently of the Endoplasmic Reticulum Pathway and HSP27's Phosphorylation Status, and Is Mediated by Exosome Liberation

PubMed Central

Klinkmann, Gerd; Diesing, Karoline; Koensgen, Dominique; Burchardt, Martin

2017-01-01

The heat shock protein HSP27 has been correlated in ovarian cancer (OC) patients with aggressiveness and chemoresistance and, therefore, represents a promising potential biomarker for OC diagnosis, prognosis, and treatment response. Notably, secretion of soluble HSP27 has been described by a few cell types and may take place as well in OC cells. Therefore, we studied HSP27 secretion mechanisms under diverse cellular conditions in an OC cell model system. Secretion of HSP27 was characterized after overexpression of HSP27 by transfected plasmids and after heat shock. Intra- and extracellular HSP27 amounts were assessed by Western blotting and ELISA. Protein secretion was blocked by brefeldin A and the impact of the HSP27 phosphorylation status was analyzed overexpressing HSP27 phosphomutants. The present study demonstrated that HSP27 secretion by OVCAR-3 and SK-OV-3 cells depends on intracellular HSP27 concentrations. Moreover, HSP27 secretion is independent of the endoplasmic reticulum secretory pathway and HSP27 phosphorylation. Notably, analysis of OC cell-born exosomes not only confirmed the concentration-dependent correlation of HSP27 expression and secretion but also demonstrated a concentration-dependent incorporation of HSP27 protein into exosomes. Thus, secreted HSP27 may become more important as an extracellular factor which controls the tumor microenvironment and might be a noninvasive biomarker. PMID:28325957

Heat Shock Protein HSP27 Secretion by Ovarian Cancer Cells Is Linked to Intracellular Expression Levels, Occurs Independently of the Endoplasmic Reticulum Pathway and HSP27's Phosphorylation Status, and Is Mediated by Exosome Liberation.

PubMed

Stope, Matthias B; Klinkmann, Gerd; Diesing, Karoline; Koensgen, Dominique; Burchardt, Martin; Mustea, Alexander

2017-01-01

The heat shock protein HSP27 has been correlated in ovarian cancer (OC) patients with aggressiveness and chemoresistance and, therefore, represents a promising potential biomarker for OC diagnosis, prognosis, and treatment response. Notably, secretion of soluble HSP27 has been described by a few cell types and may take place as well in OC cells. Therefore, we studied HSP27 secretion mechanisms under diverse cellular conditions in an OC cell model system. Secretion of HSP27 was characterized after overexpression of HSP27 by transfected plasmids and after heat shock. Intra- and extracellular HSP27 amounts were assessed by Western blotting and ELISA. Protein secretion was blocked by brefeldin A and the impact of the HSP27 phosphorylation status was analyzed overexpressing HSP27 phosphomutants. The present study demonstrated that HSP27 secretion by OVCAR-3 and SK-OV-3 cells depends on intracellular HSP27 concentrations. Moreover, HSP27 secretion is independent of the endoplasmic reticulum secretory pathway and HSP27 phosphorylation. Notably, analysis of OC cell-born exosomes not only confirmed the concentration-dependent correlation of HSP27 expression and secretion but also demonstrated a concentration-dependent incorporation of HSP27 protein into exosomes. Thus, secreted HSP27 may become more important as an extracellular factor which controls the tumor microenvironment and might be a noninvasive biomarker.

Evaluation of the secretion and release of vascular endothelial growth factor from two-dimensional culture and three-dimensional cell spheroids formed with stem cells and osteoprecursor cells.

PubMed

Lee, Hyunjin; Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2018-05-18

Co-culture has been applied in cell therapy, including stem cells, and has been reported to give enhanced functionality. In this study, stem-cell spheroids were formed in concave micromolds at different ratios of stem cells to osteoprecursor cells, and the amount of secretion of vascular endothelial growth factor (VEGF) was evaluated. Gingiva-derived stem cells and osteoprecursor cells in the amount of 6 × 105 were seeded on a 24-well culture plate or concave micromolds. The ratios of stem cells to osteoprecursor cells included: 0:4 (group 1), 1:3 (group 2), 2:2 (group 3), 3:1 (group 4), and 4:0 (group 5). The morphology of cells in a 2-dimensional culture (groups 1-5) showed a fibroblast-like appearance. The secretion of VEGF increased with the increase in stem cells, and a statistically significant increase was noted in groups 3, 4 and 5 when compared with the media-only group (p < 0.05). Osteoprecursor cells formed spheroids in concave microwells, and no noticeable change in the morphology was noted with the increase in stem cells. Spheroids containing stem cells were positive for the stem-cell markers SSEA-4. The secretion of VEGF from cell spheroids increased with the increase in stem cells. This study showed that cell spheroids formed with stem cells and osteoprecursor cells with different ratios, using microwells, had paracrine effects on the stem cells. The secretion of VEGF increased with the increase in stem cells. This stem-cell spheroid may be applied for tissue-engineering purposes.

Evolution of Sulfobacillus thermosulfidooxidans secreting alginate during bioleaching of chalcopyrite concentrate.

PubMed

Yu, R-L; Liu, A; Liu, Y; Yu, Z; Peng, T; Wu, X; Shen, L; Liu, Y; Li, J; Liu, X; Qiu, G; Chen, M; Zeng, W

2017-06-01

To explore the distribution disciplinarian of alginate on the chalcopyrite concentrate surface during bioleaching. The evolution of Sulfobacillus thermosulfidooxidans secreting alginate during bioleaching of chalcopyrite concentrate was investigated through gas chromatography coupled with mass spectrometry (GC-MS) and confocal laser scanning microscope (CLSM), and the critical synthetic genes (algA, algC, algD) of alginate were analysed by real-time polymerase chain reaction (RT-PCR). The GC-MS analysis results indicated that there was a little amount of alginate formed on the mineral surface at the early stage, while increasing largely to the maximum value at the intermediate stage, and then kept a stable value at the end stage. The CLSM analysis of chalcopyrite slice showed the same variation trend of alginate content on the mineral surface. Furthermore, the RT-PCR results showed that during the early stage of bioleaching, the expressions of the algA, algC and the algD genes were all overexpressed. However, at the final stage, the algD gene expression decreased in a large scale, and the algA and algC decreased slightly. This expression pattern was attributed to the fact that algA and algC genes were involved in several biosynthesis reactions, but the algD gene only participated in the alginate biosynthesis and this was considered as the key gene to control alginate synthesis. The content of alginate on the mineral surface increased largely at the beginning of bioleaching, and remained stable at the end of bioleaching due to the restriction of algD gene expression. Our findings provide valuable information to explore the relationship between alginate formation and bioleaching of chalcopyrite. © 2017 The Society for Applied Microbiology.

Use of conivaptan to allow aggressive hydration to prevent tumor lysis syndrome in a pediatric patient with large-cell lymphoma and SIADH.

PubMed

Rianthavorn, Pornpimol; Cain, Joan P; Turman, Martin A

2008-08-01

The available treatment options for hyponatremia secondary to SIADH are limited and not completely effective. Conivaptan is a vasopressin 1a and 2 receptor antagonist recently approved by the US Food and Drug Administration (FDA) for treating euvolemic and hypervolemic hyponatremia in adult patients. However, data on efficacy and safety of conivaptan in pediatrics are limited. We report a case of a 13-year-old boy with extensively metastasized anaplastic large-cell lymphoma. He also developed hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH) prior to chemotherapy initiation. SIADH management in this case was complicated when fluid restriction was not safely attainable. Conivaptan played a significant role in this situation by allowing provision of a large amount of intravenous fluid prior to and during induction chemotherapy. It proved to be an important component in preventing uric acid nephropathy/tumor lysis syndrome. Conivaptan induced free-water clearance as indicated by increased urine output and decreased urine osmolality. The patient responded to conivaptan without any adverse effects.

Sequential quantum secret sharing in a noisy environment aided with weak measurements

NASA Astrophysics Data System (ADS)

Ray, Maharshi; Chatterjee, Sourav; Chakrabarty, Indranil

2016-05-01

In this work we give a (n,n)-threshold protocol for sequential secret sharing of quantum information for the first time. By sequential secret sharing we refer to a situation where the dealer is not having all the secrets at the same time, at the beginning of the protocol; however if the dealer wishes to share secrets at subsequent phases she/he can realize it with the help of our protocol. First of all we present our protocol for three parties and later we generalize it for the situation where we have more (n> 3) parties. Interestingly, we show that our protocol of sequential secret sharing requires less amount of quantum as well as classical resource as compared to the situation wherein existing protocols are repeatedly used. Further in a much more realistic situation, we consider the sharing of qubits through two kinds of noisy channels, namely the phase damping channel (PDC) and the amplitude damping channel (ADC). When we carry out the sequential secret sharing in the presence of noise we observe that the fidelity of secret sharing at the kth iteration is independent of the effect of noise at the (k - 1)th iteration. In case of ADC we have seen that the average fidelity of secret sharing drops down to ½ which is equivalent to a random guess of the quantum secret. Interestingly, we find that by applying weak measurements one can enhance the average fidelity. This increase of the average fidelity can be achieved with certain trade off with the success probability of the weak measurements.

Effect of adrenal hormones on thyroid secretion and thyroid hormones on adrenal secretion in the sheep.

PubMed Central

Falconer, I R; Jacks, F

1975-01-01

1. Previous work has shown that after stressful stimuli, sheep initially secrete increased amounts of thyroid hormone, at a time when adrenal secretion is also elevated. 2. This study was designed to evaluate (a) any short-term activation or inhibition of thyroid secretion by exogenous cortisol or ACTH administered in quantities comparable to those secreted after stress in sheep and (b) any short-term effect that exogenous thyroxine or triiodothyronine may have on the concentration of plasma cortisol in the sheep. 3. Thyroid activity was measured by determination of plasma protein bound 125I (PB125I) and total 125I in thyroid vein and mixed venous (jugular) blood. Plasma cortisol and thyroxine concentrations were measured by a competitive protein-binding assay at intervals for up to 5 hr after commencement of the experiment. 4. No evidence of an activation of thyroid secretion was found during cortisol or ACTH infusion, as monitored by thyroid vein PB125I. Similarly there was no evidence of any inhibition of thyroid function, as measured by continued secretion of thyroid hormones into thyroid vein blood. 5. No effect on plasma cortisol concentration due to thyroid hormone treatment was observed. 6. It was concluded that (a) elevated circulating corticosteroids in physiological concentrations have no short-term effects on thyroid activity in the sheep and (b) the short-term alterations in thyroid and adrenal cortical secretion observed during stress in the sheep could not be attributed to direct interaction of elevated thyroid hormone concentrations with adrenal cortical secretion. PMID:170400

Protein adsorption in microengraving immunoassays.

PubMed

Song, Qing

2015-10-16

Microengraving is a novel immunoassay for characterizing multiple protein secretions from single cells. During the immunoassay, characteristic diffusion and kinetic time scales  and  determine the time for molecular diffusion of proteins secreted from the activated single lymphocytes and subsequent binding onto the glass slide surface respectively. Our results demonstrate that molecular diffusion plays important roles in the early stage of protein adsorption dynamics which shifts to a kinetic controlled mechanism in the later stage. Similar dynamic pathways are observed for protein adsorption with significantly fast rates and rapid shifts in transport mechanisms when  is increased a hundred times from 0.313 to 31.3. Theoretical adsorption isotherms follow the trend of experimentally obtained data. Adsorption isotherms indicate that amount of proteins secreted from individual cells and subsequently captured on a clean glass slide surface increases monotonically with time. Our study directly validates that protein secretion rates can be quantified by the microengraving immunoassay. This will enable us to apply microengraving immunoassays to quantify secretion rates from 10⁴-10⁵ single cells in parallel, screen antigen-specific cells with the highest secretion rate for clonal expansion and quantitatively reveal cellular heterogeneity within a small cell sample.

Protein Adsorption in Microengraving Immunoassays

PubMed Central

Song, Qing

2015-01-01

Microengraving is a novel immunoassay forcharacterizing multiple protein secretions from single cells. During the immunoassay, characteristic diffusion and kinetic time scales τD and τK determine the time for molecular diffusion of proteins secreted from the activated single lymphocytes and subsequent binding onto the glass slide surface respectively. Our results demonstrate that molecular diffusion plays important roles in the early stage of protein adsorption dynamics which shifts to a kinetic controlled mechanism in the later stage. Similar dynamic pathways are observed for protein adsorption with significantly fast rates and rapid shifts in transport mechanisms when C0* is increased a hundred times from 0.313 to 31.3. Theoretical adsorption isotherms follow the trend of experimentally obtained data. Adsorption isotherms indicate that amount of proteins secreted from individual cells and subsequently captured on a clean glass slide surface increases monotonically with time. Our study directly validates that protein secretion rates can be quantified by the microengraving immunoassay. This will enable us to apply microengraving immunoassays to quantify secretion rates from 104–105 single cells in parallel, screen antigen-specific cells with the highest secretion rate for clonal expansion and quantitatively reveal cellular heterogeneity within a small cell sample. PMID:26501282

The dynamics of secretion during sea urchin embryonic skeleton formation.

PubMed

Wilt, Fred H; Killian, Christopher E; Hamilton, Patricia; Croker, Lindsay

2008-05-01

Skeleton formation involves secretion of massive amounts of mineral precursor, usually a calcium salt, and matrix proteins, many of which are deposited on, or even occluded within, the mineral. The cell biological underpinnings of this secretion and subsequent assembly of the biomineralized skeletal element is not well understood. We ask here what is the relationship of the trafficking and secretion of the mineral and matrix within the primary mesenchyme cells of the sea urchin embryo, cells that deposit the endoskeletal spicule. Fluorescent labeling of intracellular calcium deposits show mineral precursors are present in granules visible by light microscopy, from whence they are deposited in the endoskeletal spicule, especially at its tip. In contrast, two different matrix proteins tagged with GFP are present in smaller post-Golgi vesicles only seen by electron microscopy, and the secreted protein are only incorporated into the spicule in the vicinity of the cell of origin. The matrix protein, SpSM30B, is post-translationally modified during secretion, and this processing continues after its incorporation into the spicule. Our findings also indicate that the mineral precursor and two well characterized matrix proteins are trafficked by different cellular routes.

The Dynamics of Secretion during Sea Urchin Embryonic Skeleton Formation

PubMed Central

Wilt, Fred H.; Killian, Christopher E.; Hamilton, Patricia; Croker, Lindsay

2008-01-01

Skeleton formation involves secretion of massive amounts of mineral precursor, usually a calcium salt, and matrix proteins, many of which are deposited on, or even occluded within, the mineral. The cell biological underpinnings of this secretion and subsequent assembly of the biomineralized skeletal element is not well understood. We ask here what is the relationship of the trafficking and secretion of the mineral and matrix within the primary mesenchyme cells of the sea urchin embryo, cells that deposit the endoskeletal spicule. Fluorescent labeling of intracellular calcium deposits show mineral precursors are present in granules visible by light microscopy, from whence they are deposited in the endoskeletal spicule, especially at its tip. In contrast, two different matrix proteins tagged with GFP are present in smaller post-Golgi vesicles only seen by electron microscopy, and the secreted protein are only incorporated into the spicule in the vicinity of the cell of origin. The matrix protein, SpSM30B, is post-translationally modified during secretion, and this processing continues after its incorporation into the spicule. Our findings also indicate that the mineral precursor and two well characterized matrix proteins are trafficked by different cellular routes. PMID:18355808

Xanthine oxidoreductase mediates membrane docking of milk-fat droplets but is not essential for apocrine lipid secretion.

PubMed

Monks, Jenifer; Dzieciatkowska, Monika; Bales, Elise S; Orlicky, David J; Wright, Richard M; McManaman, James L

2016-10-15

Xanthine oxidoreductase (XOR) modulates milk lipid secretion and lactation initiation. XOR is required for butyrophilin1a1 clustering in the membrane during milk lipid secretion. XOR mediates apical membrane reorganization during milk lipid secretion. Loss of XOR delays milk fat globule secretion. XOR loss alters the proteome of milk fat globules. Apocrine secretion is utilized by epithelial cells of exocrine glands. These cells bud off membrane-bound particles into the lumen of the gland, losing a portion of the cytoplasm in the secretion product. The lactating mammary gland secretes milk lipid by this mechanism, and xanthine oxidoreductase (XOR) has long been thought to be functionally important. We generated mammary-specific XOR knockout (MGKO) mice, expecting lactation to fail. Histology of the knockout glands showed very large lipid droplets enclosed in the mammary alveolar cells, but milk analysis showed that these large globules were secreted. Butyrophilin, a membrane protein known to bind to XOR, was clustered at the point of contact of the cytoplasmic lipid droplet with the apical plasma membrane, in the wild-type gland but not in the knockout, suggesting that XOR mediates 'docking' to this membrane. Secreted milk fat globules were isolated from mouse milk of wild-type and XOR MGKO dams, and subjected to LC-MS/MS for analysis of protein component. Proteomic results showed that loss of XOR leads to an increase in cytoplasmic, cytoskeletal, Golgi apparatus and lipid metabolism proteins associated with the secreted milk fat globule. Association of XOR with the lipid droplet results in membrane docking and more efficient retention of cytoplasmic components by the secretory cell. Loss of XOR then results in a reversion to a more rudimentary, less efficient, apocrine secretion mechanism, but does not prevent milk fat globule secretion. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Bladder cancer cells secrete while normal bladder cells express but do not secrete AGR2

DOE PAGES

Ho, Melissa E.; Quek, Sue -Ing; True, Lawrence D.; ...

2016-02-15

Anterior gradient 2 (AGR2) is a cancer-associated secreted protein found predominantly in adenocarcinomas. Given its ubiquity in solid tumors, cancer-secreted AGR2 could be a useful biomarker in urine or blood for early detection. Normal organs express AGR2 and might also secrete AGR2, which would impact on the utility of AGR2 as a cancer biomarker. Uniform AGR2 expression is found in the normal bladder urothelium. Little AGR2 is, however, secreted by the urothelial cells as no measurable amounts could be detected in urine. The urinary proteomes of healthy people contain no listing for AGR2. The blood proteomes also contain no significantmore » peptide counts for AGR2 suggesting that little urothelial secretion into capillaries of the lamina propria. Expression is lost in urothelial carcinoma, but 25% primary tumors retained AGR2 expression in a cohort of lymph node positive cases. AGR2 is secreted by the urothelial carcinoma cells as urinary AGR2 was measured in the voided urine of 25% of the cases analyzed in a cohort of cancer vs. non-cancer urine, which matched the frequency of AGR2-positive urothelial carcinoma. Since cancer cells secrete AGR2 while normal cells do not, its measurement in body fluids could be used to indicate tumor presence. In addition to secretion, AGR2 is also localized to the cell surface. Thus, secretion/cell surface localization of AGR2 is pecific to cancer while expression itself is not. Lastly, since AGR2 is found in many solid tumor types, this tumor-associated antigen constitutes a highly promising therapeutic target.« less

Bladder cancer cells secrete while normal bladder cells express but do not secrete AGR2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Melissa E.; Quek, Sue -Ing; True, Lawrence D.

Anterior gradient 2 (AGR2) is a cancer-associated secreted protein found predominantly in adenocarcinomas. Given its ubiquity in solid tumors, cancer-secreted AGR2 could be a useful biomarker in urine or blood for early detection. Normal organs express AGR2 and might also secrete AGR2, which would impact on the utility of AGR2 as a cancer biomarker. Uniform AGR2 expression is found in the normal bladder urothelium. Little AGR2 is, however, secreted by the urothelial cells as no measurable amounts could be detected in urine. The urinary proteomes of healthy people contain no listing for AGR2. The blood proteomes also contain no significantmore » peptide counts for AGR2 suggesting that little urothelial secretion into capillaries of the lamina propria. Expression is lost in urothelial carcinoma, but 25% primary tumors retained AGR2 expression in a cohort of lymph node positive cases. AGR2 is secreted by the urothelial carcinoma cells as urinary AGR2 was measured in the voided urine of 25% of the cases analyzed in a cohort of cancer vs. non-cancer urine, which matched the frequency of AGR2-positive urothelial carcinoma. Since cancer cells secrete AGR2 while normal cells do not, its measurement in body fluids could be used to indicate tumor presence. In addition to secretion, AGR2 is also localized to the cell surface. Thus, secretion/cell surface localization of AGR2 is pecific to cancer while expression itself is not. Lastly, since AGR2 is found in many solid tumor types, this tumor-associated antigen constitutes a highly promising therapeutic target.« less

Dexamethasone modifies mitomycin C-triggered interleukin-8 secretion in isolated human Tenon's capsule fibroblasts.

PubMed

Ho, Wei-Ting; Chen, Tsan-Chi; Chou, San-Fang; Chang, Shu-Wen

2014-07-01

Intraoperative mitomycin C (MMC) is widely used to prevent pterygium recurrence and glaucoma filtering bleb failure, but it has been shown to induce corneal inflammation and cell death. Postoperative dexamethasone (DEX) is advocated to reduce MMC-related inflammation and cell death in corneal fibroblasts. Nevertheless, its long-term regulation mechanism in Tenon's capsule remains to be explored. The purpose of this study was to investigate how DEX modifies MMC's effects in human Tenon's capsule fibroblasts (HTFs). HTFs isolated from the pterygium surgical patients (n = 6) were treated with MMC at 0, 0.1, 0.2, and 0.4 mg/ml for 5 min and incubated in DEX at 10 μM for 0, 1, 2, and 3 days. Recombinant interleukin-8 (IL-8) was used to verify the effect of MMC-related IL-8 secretion. Cell proliferation of all the treated cells was analyzed by WST-1 assay. The amount of IL-8 secretion in HTFs was determined by enzyme-linked immunosorbent assay. Immunoblotting assay was used to analyze the expression of peroxisome-proliferator-activated receptor gamma (PPARγ) and B-cell lymphoma-extra large (Bcl-xL). Our results revealed that MMC significantly reduced the HTF cell proliferation rate. Additionally, MMC significantly upregulated IL-8 secretion in HTFs concentration-dependently. At 3 days post treatment (dpt), 5-min exposures to 0.1, 0.2, and 0.4 mg/ml MMC resulted in 1.4-fold (p = 0.012), 1.6-fold (p = 0.012), and 2.5-fold (p = 0.001) increases of IL-8 secretion. In contrast, DEX reversed the MMC-retarded cell proliferation rate (p = 0.036) and repressed MMC-related IL-8 secretion by 33.5% at 3 dpt (p = 0.003). Addition of recombinant IL-8 noticeably suppressed HTF cell proliferation in a concentration-dependent manner. DEX stimulated upregulation of both PPARγ and Bcl-xL at 1 dpt in normal HTFs and at 2 dpt in MMC-treated HTFs. PPARγ silencing reduced expression of PPARγ and Bcl-xL, but enhanced IL-8 secretion (p < 0.001). On the other hand, Bcl-xL silencing enhanced IL-8 secretion (p < 0.001), but did not affect PPARγ expression. These revealed that IL-8 secretion in HTFs is modulated by PPARγ-dependent Bcl-xL signaling. We conclude that DEX reversed the MMC-inhibited HTF cell proliferation via diminishing the MMC-induced IL-8 secretion, which resulted from a late-phase upregulation of the PPARγ and Bcl-xL. These long-term effects suggest a beneficial postoperative DEX treatment following intraoperative MMC application. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-Dimensional Circular Quantum Secret Sharing Using Orbital Angular Momentum

NASA Astrophysics Data System (ADS)

Tang, Dawei; Wang, Tie-jun; Mi, Sichen; Geng, Xiao-Meng; Wang, Chuan

2016-11-01

Quantum secret sharing is to distribute secret message securely between multi-parties. Here exploiting orbital angular momentum (OAM) state of single photons as the information carrier, we propose a high-dimensional circular quantum secret sharing protocol which increases the channel capacity largely. In the proposed protocol, the secret message is split into two parts, and each encoded on the OAM state of single photons. The security of the protocol is guaranteed by the laws of non-cloning theorem. And the secret messages could not be recovered except that the two receivers collaborated with each other. Moreover, the proposed protocol could be extended into high-level quantum systems, and the enhanced security could be achieved.

Bacterial Translocation Ratchets: Shared Physical Principles with Different Molecular Implementations: How bacterial secretion systems bias Brownian motion for efficient translocation of macromolecules.

PubMed

Hepp, Christof; Maier, Berenike

2017-10-01

Secretion systems enable bacteria to import and secrete large macromolecules including DNA and proteins. While most components of these systems have been identified, the molecular mechanisms of macromolecular transport remain poorly understood. Recent findings suggest that various bacterial secretion systems make use of the translocation ratchet mechanism for transporting polymers across the cell envelope. Translocation ratchets are powered by chemical potential differences generated by concentration gradients of ions or molecules that are specific to the respective secretion systems. Bacteria employ these potential differences for biasing Brownian motion of the macromolecules within the conduits of the secretion systems. Candidates for this mechanism include DNA import by the type II secretion/type IV pilus system, DNA export by the type IV secretion system, and protein export by the type I secretion system. Here, we propose that these three secretion systems employ different molecular implementations of the translocation ratchet mechanism. © 2017 The Authors. BioEssays Published by WILEY Periodicals, Inc.

Reduction of diffusion barriers in isolated rat islets improves survival, but not insulin secretion or transplantation outcome

PubMed Central

Janette Williams, S; Huang, Han-Hung; Kover, Karen; Moore, Wayne; Berkland, Cory; Singh, Milind; Smirnova, Irina V; MacGregor, Ronal

2010-01-01

For people with type 1 diabetes and severe hypoglycemic unawareness, islet transplants offer hope for improving the quality of life. However, islet cell death occurs quickly during or after transplantation, requiring large quantities of islets per transplant. The purpose of this study was to determine whether poor function demonstrated in large islets was a result of diffusion barriers and if removing those barriers could improve function and transplantation outcomes. Islets were isolated from male DA rats and measured for cell viability, islet survival, glucose diffusion and insulin secretion. Modeling of diffusion barriers was completed using dynamic partial differential equations for a sphere. Core cell death occurred in 100% of the large islets (diameter >150 µm), resulting in poor survival within 7 days after isolation. In contrast, small islets (diameter <100 µm) exhibited good survival rates in culture (91%). Glucose diffusion into islets was tracked with 2-NBDG; 4.2 µm/min in small islets and 2.8 µm/min in large islets. 2-NBDG never permeated to the core cells of islets larger than 150 µm diameter. Reducing the diffusion barrier in large islets improved their immediate and long-term viability in culture. However, reduction of the diffusion barrier in large islets failed to improve their inferior in vitro insulin secretion compared to small islets, and did not return glucose control to diabetic animals following transplantation. Thus, diffusion barriers lead to low viability and poor survival for large islets, but are not solely responsible for the inferior insulin secretion or poor transplantation outcomes of large versus small islets. PMID:20885858

Entropy change of biological dynamics in COPD.

PubMed

Jin, Yu; Chen, Chang; Cao, Zhixin; Sun, Baoqing; Lo, Iek Long; Liu, Tzu-Ming; Zheng, Jun; Sun, Shixue; Shi, Yan; Zhang, Xiaohua Douglas

2017-01-01

In this century, the rapid development of large data storage technologies, mobile network technology, and portable medical devices makes it possible to measure, record, store, and track analysis of large amount of data in human physiological signals. Entropy is a key metric for quantifying the irregularity contained in physiological signals. In this review, we focus on how entropy changes in various physiological signals in COPD. Our review concludes that the entropy change relies on the types of physiological signals under investigation. For major physiological signals related to respiratory diseases, such as airflow, heart rate variability, and gait variability, the entropy of a patient with COPD is lower than that of a healthy person. However, in case of hormone secretion and respiratory sound, the entropy of a patient is higher than that of a healthy person. For mechanomyogram signal, the entropy increases with the increased severity of COPD. This result should give valuable guidance for the use of entropy for physiological signals measured by wearable medical device as well as for further research on entropy in COPD.

Structural definition of a potent macrophage activating factor derived from vitamin D3-binding protein with adjuvant activity for antibody production.

PubMed

Yamamoto, N

1996-10-01

Incubation of human vitamin D3-binding protein (Gc protein), with a mixture of immobilized beta-galactosidase and sialidase, efficiently generated a potent macrophage activating factor, a protein with N-acetylgalactosamine as the remaining sugar. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase, and isolation of the intermediates with immobilized lectins, revealed that either sequence of hydrolysis of Gc glycoprotein by these glycosidases yields the macrophage-activating factor, implying that Gc protein carries a trisaccharide composed of N-acetylgalactosamine and dibranched galactose and sialic acid termini. A 3 hr incubation of mouse peritoneal macrophages with picomolar amounts of the enzymatically generated macrophage-activating factor (GcMAF) resulted in a greatly enhanced phagocytic activity. Administration of a minute amount (10-50 pg/mouse) of GcMAF resulted in a seven- to nine-fold enhanced phagocytic activity of macrophages. Injection of sheep red blood cells (SRBC) along with GcMAF into mice produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days.

Stimulants and growth in children with attention-deficit/hyperactivity disorder.

PubMed

Negrao, Bianca Lee; Viljoen, Margaretha

2011-07-01

Initial suggestions that suppression of growth may be an intrinsic characteristic of attention-deficit/hyperactivity disorder (ADHD) have now largely been disproven. Although controversy persists regarding the possible negative effect of adrenergic stimulants on growth in children with ADHD, the consensus that appears to be reached in the scientific literature is that stimulant usage may cause a manageable attenuation of growth in these children. Since it is known that stimulants increase the amount of dopamine and noradrenaline in the synapse, this writing suggests that these increases in dopamine and noradrenaline are responsible for the growth attenuation in these children. It appears that increased amounts of dopamine and noradrenaline have the ability to inhibit the secretion of growth hormone and growth-related hormones such as prolactin, thyroid hormones, sex hormones and insulin. Therefore, it would be reasonable to suggest that the increases in dopamine and noradrenaline caused by stimulant usage can disrupt the homeostasis of both growth hormone and growth-related hormones, generating the potential for the suppression of growth. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Genetic Program of Pancreatic β-Cell Replication In Vivo.

PubMed

Klochendler, Agnes; Caspi, Inbal; Corem, Noa; Moran, Maya; Friedlich, Oriel; Elgavish, Sharona; Nevo, Yuval; Helman, Aharon; Glaser, Benjamin; Eden, Amir; Itzkovitz, Shalev; Dor, Yuval

2016-07-01

The molecular program underlying infrequent replication of pancreatic β-cells remains largely inaccessible. Using transgenic mice expressing green fluorescent protein in cycling cells, we sorted live, replicating β-cells and determined their transcriptome. Replicating β-cells upregulate hundreds of proliferation-related genes, along with many novel putative cell cycle components. Strikingly, genes involved in β-cell functions, namely, glucose sensing and insulin secretion, were repressed. Further studies using single-molecule RNA in situ hybridization revealed that in fact, replicating β-cells double the amount of RNA for most genes, but this upregulation excludes genes involved in β-cell function. These data suggest that the quiescence-proliferation transition involves global amplification of gene expression, except for a subset of tissue-specific genes, which are "left behind" and whose relative mRNA amount decreases. Our work provides a unique resource for the study of replicating β-cells in vivo. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Secretory production of tetrameric native full-length streptavidin with thermostability using Streptomyces lividans as a host.

PubMed

Noda, Shuhei; Matsumoto, Takuya; Tanaka, Tsutomu; Kondo, Akihiko

2015-01-13

Streptavidin is a tetrameric protein derived from Streptomyces avidinii, and has tight and specific biotin binding affinity. Applications of the streptavidin-biotin system have been widely studied. Streptavidin is generally produced using protein expression in Escherichia coli. In the present study, the secretory production of streptavidin was carried out using Streptomyces lividans as a host. In this study, we used the gene encoding native full-length streptavidin, whereas the core region is generally used for streptavidin production in E. coli. Tetrameric streptavidin composed of native full-length streptavidin monomers was successfully secreted in the culture supernatant of S. lividans transformants, and had specific biotin binding affinity as strong as streptavidin produced by E. coli. The amount of Sav using S. lividans was about 9 times higher than using E. coli. Surprisingly, streptavidin produced by S. lividans exhibited affinity to biotin after boiling, despite the fact that tetrameric streptavidin is known to lose its biotin binding ability after brief boiling. We successfully produced a large amount of tetrameric streptavidin as a secretory-form protein with unique thermotolerance.

The interrelationships of thyroid and growth hormones: effect of growth hormone releasing hormone in hypo- and hyperthyroid male rats.

PubMed

Root, A W; Shulman, D; Root, J; Diamond, F

1986-01-01

Growth hormone (GH) and the thyroid hormones interact in the hypothalamus, pituitary and peripheral tissues. Thyroid hormone exerts a permissive effect upon the anabolic and metabolic effects of GH, and increases pituitary synthesis of this protein hormone. GH depresses the secretion of thyrotropin and the thyroid hormones and increases the peripheral conversion of thyroxine to triiodothyronine. In the adult male rat experimental hypothyroidism produced by ingestion of propylthiouracil depresses the GH secretory response to GH-releasing hormone in vivo and in vitro, reflecting the lowered pituitary stores of GH in the hypothyroid state. Short term administration of large amounts of thyroxine with induction of the hyperthyroid state does not affect the in vivo GH secretory response to GH-releasing hormone in this animal.

Key role of regulated upon activation normal T-cell expressed and secreted, nonstructural protein1 and myeloperoxidase in cytokine storm induced by influenza virus PR-8 (A/H1N1) infection in A549 bronchial epithelial cells.

PubMed

Phung, Thuy Thi Bich; Sugamata, Ryuichi; Uno, Kazuko; Aratani, Yasuaki; Ozato, Keiko; Kawachi, Shoji; Thanh Nguyen, Liem; Nakayama, Toshinori; Suzuki, Kazuo

2011-12-01

Influenza virus infection causes severe respiratory disease such as that due to avian influenza (H5N1). Influenza A viruses proliferate in human epithelial cells, which produce inflammatory cytokines/chemokines as a "cytokine storm" attenuated with the viral nonstructural protein 1 (NS1). Cytokine/chemokine production in A549 epithelial cells infected with influenza A/H1N1 virus (PR-8) or nonstructural protein 1 (NS1) plasmid was examined in vitro. Because tumor necrosis factor-α (TNF-α) and regulated upon activation normal T-cell expressed and secreted (RANTES) are predominantly produced from cells infected with PR-8 virus, the effects of mRNA knockdown of these cytokines were investigated. Small interfering (si)TNF-α down-regulated RANTES expression and secretion of RANTES, interleukin (IL)-8, and monocyte chemotactic protein-1 (MCP-1). In addition, siRANTES suppressed interferon (IFN)-γ expression and secretion of RANTES, IL-8, and MCP-1, suggesting that TNF-α stimulates production of RANTES, IL-8, MCP-1, and IFN-γ, and RANTES also increased IL-8, MCP-1, and IFN-γ. Furthermore, administration of TNF-α promoted increased secretion of RANTES, IL-8, and MCP-1. Administration of RANTES enhanced IL-6, IL-8, and MCP-1 production without PR-8 infection. These results strongly suggest that, as an initial step, TNF-α regulates RANTES production, followed by increase of IL-6, IL-8, and MCP-1 and IFNs concentrations. At a later stage, cells transfected with viral NS1 plasmid showed production of a large amount of IL-8 and MCP-1 in the presence of the H(2)O(2)-myeloperoxidse (MPO) system, suggesting that NS1 of PR-8 may induce a "cytokine storm" from epithelial cells in the presence of an H(2)O(2)-MPO system. © 2011 The Societies and Blackwell Publishing Asia Pty Ltd.

Cell differentiation: therapeutical challenges in diabetes.

PubMed

Roche, Enrique; Vicente-Salar, Nestor; Arribas, Maribel; Paredes, Beatriz

2012-01-01

Stem cells, derived from either embryonic or adult tissues, are considered to be potential sources of insulin-secreting cells to be transplanted into type 1 and advanced stages of type 2 diabetic patients. Many laboratories have considered this possibility, resulting in a large amount of published protocols, with a wide degree of complexity among them. Our group was the first to report that it was possible to obtain insulin-secreting cells from mouse embryonic stem cells, proving the feasibility of this new challenge. The same observation was immediately reported using human embryonic stem cells. However, the resulting cell product was not properly characterised, affecting the reproducibility of the protocol by other groups. A more elaborated protocol was developed by Lumelsky and co-workers, demonstrating that neuroectodermal cells could be an alternative source for insulin-producing cells. However, the resulting cells of this protocol produced low amounts of the hormone. This aimed other groups to perform key changes in order to improve the insulin content of the resulting cells. Recently, Baetge's group has published a new protocol based on the knowledge accumulated in pancreatic development. In this protocol, human embryonic stem cells were differentiated into islet-like structures through a five step protocol, emulating the key steps during embryonic development of the endocrine pancreas. The final cell product, however, seemed to be in an immature state, thus further improvement is required. Despite this drawback, the protocol represents the culmination of work performed by different groups and offers new research challenges for the investigators in this exciting field. Concerning adult stem cells, the possibility of identifying pancreatic precursors or of reprogramming extrapancreatic derived cells are key possibilities that may circumvent the problems that appear when using embryonic stem cells, such as immune rejection and tumour formation.

Comprehensive analysis of the cellulolytic system reveals its potential for deconstruction of lignocellulosic biomass in a novel Streptomyces sp.

PubMed

Pinheiro, Guilherme L; de Azevedo-Martins, Allan C; Albano, Rodolpho M; de Souza, Wanderley; Frases, Susana

2017-01-01

The giant snail Achatina fulica is considered an invasive species in most territories in which it was introduced, due to its ability to process a large amount of lignocellulose as a consequence of the presence of a cellulolytic-associated microflora. Streptomyces are well known as crucial agents in the decomposition of complex polymers in soil environments and also as cellulolytic symbionts commonly associated with herbivore insects. Here, we employed a combination of genomic and biochemical tools for a detailed evaluation of the cellulolytic potential of Streptomyces sp. I1.2, an aerobic bacterium isolated from the intestinal lumen of A. fulica in a screening for cellulolytic bacteria. Genomic analysis revealed that the ratio and diversity of CAZy domains and GH families coded by Streptomyces sp. I1.2 are comparable to those present in other highly cellulolytic bacteria. After growth on crystalline cellulose or sugarcane bagasse as sole carbon sources, the functionality of several genes encoding endoglucanases, cellobiohydrolases, xylanases, CBMs, and one β-glucosidase were confirmed by the combination of enzymatic activity measurements, zymography, TLC, and cellulose-binding assays. The endoglucanases secreted by this isolate were stable at 50 °C and exhibited activity over a broad pH range between 4.0 and 8.0. The endoglucanases and cellobiohydrolases secreted by Streptomyces sp. I1.2 exhibited specific activities that were similar to the levels present in a commercial cellulase preparation from Trichoderma reesei, while I1.2 xylanase levels were even 350 % higher. The results presented here show that Streptomyces sp. I1.2 is promising for future biotechnological applications, since it is able to produce endoglucanases, cellobiohydrolases, and xylanases in appreciable amounts when grown on a low-cost residue such as sugarcane bagasse.

Biliary secretion of fluid-phase markers by the isolated perfused rat liver. Role of transcellular vesicular transport.

PubMed Central

Lake, J R; Licko, V; Van Dyke, R W; Scharschmidt, B F

1985-01-01

In these studies, we have used several approaches to systematically explore the contribution of transcellular vesicular transport (transcytosis) to the blood-to-bile movement of inert fluid-phase markers of widely varying molecular weight. First, under steady-state conditions, the perfused rat liver secreted even large markers in appreciable amounts. The bile-to-plasma (B/P) ratio of these different markers, including microperoxidase (B/P ratio = 0.06; mol wt = 1,879), insulin (B/P ratio = 0.09, mol wt = 5,000), horseradish peroxidase (B/P ratio = 0.04, mol wt = 40,000), and dextran (B/P ratio = 0.09, mol wt = 70,000), exhibited no clear ordering based on size alone, and when dextrans of two different sizes (40,000 and 70,000 mol wt) were studied simultaneously, the relative amounts of the two dextran species in bile were the same as in perfusate. Taurocholate administration produced a 71% increase in bile flow but little or no (0-20%) increase in the output of horseradish peroxidase, microperoxidase, inulin, and dextran. Second, under nonsteady-state conditions in which the appearance in or disappearance from bile of selected markers was studied after their abrupt addition to or removal from perfusate, erythritol reached a B/P ratio of 1 within 2 min. Microperoxidase and dextran appeared in bile only after a lag period of approximately 12 min and then slowly approached maximal values, whereas sucrose exhibited kinetically intermediate behavior. A similar pattern was observed after removal of greater than 95% of the marker from the perfusate. Erythritol rapidly reapproached a B/P ratio of 1, whereas the B/P ratio for sucrose, dextran, and microperoxidase fell much more slowly and exceeded 1 for a full 30 min after perfusate washout. Finally, electron microscopy and fluorescence microscopy of cultured hepatocytes demonstrated the presence of horseradish peroxidase and fluorescein-dextran, respectively, in intracellular vesicles, and fractionation of perfused liver homogenates revealed that at least 35-50% of sucrose, inulin, and dextran was associated with subcellular organelles. Collectively, these observations are most compatible with a transcytosis pathway that contributes minimally to the secretion of erythritol, but accounts for a substantial fraction of sucrose secretion and virtually all (greater than 95%) of the blood-to-bile transport of microperoxidase and larger markers. These findings have important implications with respect to current concepts of canalicular bile formation as well as with respect to the conventional use of solutes such as sucrose as markers of canalicular or paracellular pathway permeability. Images PMID:2411761

Cevimeline-induced monophasic salivation from the mouse submandibular gland: decreased Na+ content in saliva results from specific and early activation of Na+/H+ exchange.

PubMed

Kondo, Yusuke; Nakamoto, Tetsuji; Mukaibo, Taro; Kidokoro, Manami; Masaki, Chihiro; Hosokawa, Ryuji

2011-04-01

Cevimeline and pilocarpine are muscarinic agonists used clinically to treat dry mouth. In this study, we explored fluid secretion from mouse submandibular glands to determine the mechanism of cevimeline, pilocarpine, and an experimentally used agent carbachol. Cevimeline evoked almost the same amount of secretion at concentrations from 30 μM to 1 mM. Pilocarpine also induced secretion at a concentration as low as 1 μM and was the most powerful secretagogue at 10 μM. Secretion was induced by carbachol at 0.1 μM, with maximum secretion at 1.0 μM. Cevimeline induced monophasic secretion at all concentrations tested, whereas higher concentrations of pilocarpine and carbachol induced secretion with variable kinetics, i.e., an initial transient high flow rate, followed by decreased secretion after 2 to 3 min. In the presence of an epithelial Na(+) channel blocker, amiloride, neither carbachol nor pilocarpine affected the Na(+) level of secreted saliva; however, it significantly increased the Na(+) content of cevimeline-induced saliva. The intracellular Ca(2+) response of acinar cells was almost identical among all three agents, although recovery after drug removal was slower for cevimeline and pilocarpine. A profound decrease in intracellular pH was observed during pilocarpine and carbachol treatment, whereas intracellular acidification induced by cevimeline was only seen in the presence of a Na(+)/H(+) exchange inhibitor. When external HCO(3)(-) was removed, cevimeline-induced saliva significantly decreased. These findings suggest that cevimeline specifically activates Na(+)/H(+) exchange and may promote Na(+) reabsorption by stabilizing epithelial sodium channel activity.

Characteristics of repaglinide effects on insulin secretion.

PubMed

Takahashi, Harumi; Hidaka, Shihomi; Seki, Chihiro; Yokoi, Norihide; Seino, Susumu

2018-06-05

The dynamics of insulin secretion stimulated by repaglinide, a glinide, and the combinatorial effects of repaglinide and incretin were investigated. At 4.4 mM glucose, repaglinide induced insulin secretion with a gradually increasing first phase, showing different dynamics from that induced by glimepiride, a sulfonylurea. In the presence of glucagon-like peptide-1 (GLP-1), insulin secretion by repaglinide was augmented significantly but to lesser extent and showed different dynamics from that by glimepiride. At 4.4 mM glucose, the intracellular Ca 2+ level was gradually increased by repaglinide alone or repaglinide plus GLP-1, which differs from the Ca 2+ dynamics by glimepiride alone or glimepiride plus GLP-1, suggesting that the difference in Ca 2+ dynamics contributes to the difference in the dynamics of insulin secretion. At a higher concentration (8.8 mM) of glucose, the dynamics of insulin secretion stimulated by repaglinide was similar to that by glimepiride. Combination of repaglinide and GLP-1 significantly augmented insulin secretion, the amount of which was comparable to that by the combination of glimepiride and GLP-1. The Ca 2+ dynamics was similar for repaglinide and glimepiride at 8.8 mM glucose. Our data indicate that repaglinide has characteristic properties in its effects on the dynamics of insulin secretion and intracellular Ca 2+ and that the combination of repaglinide and GLP-1 stimulates insulin secretion more effectively than the combination of glimepiride and GLP-1 at a high concentration of glucose, providing a basis for its use in clinical settings. Copyright © 2018 Elsevier B.V. All rights reserved.

Differential secretion pathways of proteins fused to the Escherichia coli maltose binding protein (MBP) in Pichia pastoris.

PubMed

Moua, Pachai S; Gonzalez, Alfonso; Oshiro, Kristin T; Tam, Vivian; Li, Zhiguo Harry; Chang, Jennifer; Leung, Wilson; Yon, Amy; Thor, Der; Venkatram, Sri; Franz, Andreas H; Risser, Douglas D; Lin-Cereghino, Joan; Lin-Cereghino, Geoff P

2016-08-01

The Escherichia coli maltose binding protein (MBP) is an N-terminal fusion partner that was shown to enhance the secretion of some heterologous proteins from the yeast Pichia pastoris, a popular host for recombinant protein expression. The amount of increase in secretion was dependent on the identity of the cargo protein, and the fusions were proteolyzed prior to secretion, limiting its use as a purification tag. In order to overcome these obstacles, we used the MBP as C-terminal partner for several cargo peptides. While the Cargo-MBP proteins were no longer proteolyzed in between these two moieties when the MBP was in this relative position, the secretion efficiency of several fusions was lower than when MBP was located at the opposite end of the cargo protein (MBP-Cargo). Furthermore, fluorescence analysis suggested that the MBP-EGFP and EGFP-MBP proteins followed different routes within the cell. The effect of several Pichia pastoris beta-galactosidase supersecretion (bgs) strains, mutants showing enhanced secretion of select reporters, was also investigated on both MBP-EGFP and EGFP-MBP. While the secretion efficiency, proteolysis and localization of the MBP-EGFP was influenced by the modified function of Bgs13, EGFP-MBP behavior was not affected in the bgs strain. Taken together, these results indicate that the location of the MBP in a fusion affects the pathway and trans-acting factors regulating secretion in P. pastoris. Copyright © 2016 Elsevier Inc. All rights reserved.

Two-Partner Secretion: Combining Efficiency and Simplicity in the Secretion of Large Proteins for Bacteria-Host and Bacteria-Bacteria Interactions

PubMed Central

Guérin, Jeremy; Bigot, Sarah; Schneider, Robert; Buchanan, Susan K.; Jacob-Dubuisson, Françoise

2017-01-01

Initially identified in pathogenic Gram-negative bacteria, the two-partner secretion (TPS) pathway, also known as Type Vb secretion, mediates the translocation across the outer membrane of large effector proteins involved in interactions between these pathogens and their hosts. More recently, distinct TPS systems have been shown to secrete toxic effector domains that participate in inter-bacterial competition or cooperation. The effects of these systems are based on kin vs. non-kin molecular recognition mediated by specific immunity proteins. With these new toxin-antitoxin systems, the range of TPS effector functions has thus been extended from cytolysis, adhesion, and iron acquisition, to genome maintenance, inter-bacterial killing and inter-bacterial signaling. Basically, a TPS system is made up of two proteins, the secreted TpsA effector protein and its TpsB partner transporter, with possible additional factors such as immunity proteins for protection against cognate toxic effectors. Structural studies have indicated that TpsA proteins mainly form elongated β helices that may be followed by specific functional domains. TpsB proteins belong to the Omp85 superfamily. Open questions remain on the mechanism of protein secretion in the absence of ATP or an electrochemical gradient across the outer membrane. The remarkable dynamics of the TpsB transporters and the progressive folding of their TpsA partners at the bacterial surface in the course of translocation are thought to be key elements driving the secretion process. PMID:28536673

Effects of endurance exercise training, metformin, and their combination on adipose tissue leptin and IL-10 secretion in OLETF rats

PubMed Central

Padilla, Jaume; Arce-Esquivel, Arturo A.; Bayless, David S.; Martin, Jeffrey S.; Leidy, Heather J.; Booth, Frank W.; Rector, R. Scott; Laughlin, M. Harold

2012-01-01

Adipose tissue inflammation plays a role in cardiovascular (CV) and metabolic diseases associated with obesity, insulin resistance, and type 2 diabetes mellitus (T2DM). The interactive effects of exercise training and metformin, two first-line T2DM treatments, on adipose tissue inflammation are not known. Using the hyperphagic, obese, insulin-resistant Otsuka Long-Evans Tokushima Fatty (OLETF) rat model, we tested the hypothesis that treadmill training, metformin, or a combination of these reduces the secretion of proinflammatory cytokines from adipose tissue. Compared with Long-Evans Tokushima Otsuka (LETO) control rats (L-Sed), sedentary OLETF (O-Sed) animals secreted significantly greater amounts of leptin from retroperitoneal adipose tissue. Conversely, secretion of interleukin (IL)-10 by O-Sed adipose tissue was lower than that in L-Sed animals. Examination of leptin and IL-10 secretion from adipose tissue in OLETF groups treated with endurance exercise training (O-EndEx), metformin treatment (O-Met), and a combination of these (O-E+M) from 20 to 32 wk of age indicated that 1) leptin secretion from adipose tissue was reduced in O-Met and O-E+M, but not O-EndEx animals; 2) adipose tissue IL-10 secretion was increased in O-EndEx and O-E+M but not in O-Met animals; and 3) only the combined treatment (O-E+M) displayed both a reduction in leptin secretion and an increase in IL-10 secretion. Leptin and IL-10 concentrations in adipose tissue–conditioned buffers were correlated with their plasma concentrations, adipocyte diameters, and total adiposity. Overall, this study indicates that exercise training and metformin have additive influences on adipose tissue secretion and plasma concentrations of leptin and IL-10. PMID:23019312

Recombinant MUC1 mucin with a breast cancer-like O-glycosylation produced in large amounts in Chinese-hamster ovary cells.

PubMed Central

Bäckström, Malin; Link, Thomas; Olson, Fredrik J; Karlsson, Hasse; Graham, Rosalind; Picco, Gianfranco; Burchell, Joy; Taylor-Papadimitriou, Joyce; Noll, Thomas; Hansson, Gunnar C

2003-01-01

We have developed an expression system for the production of large quantities of recombinant MUC1 mucin in CHO-K1 (Chinese-hamster ovary K1) cells. The extracellular part of human MUC1, including 16 MUC1 tandem repeats, was produced as a fusion protein with murine IgG Fc, with an intervening enterokinase cleavage site for the removal of the Fc tail. Stable MUC1-IgG-producing CHO-K1 clones were generated and were found to secrete MUC1-IgG into the culture medium. After adaptation to suspension culture in protein-free medium in a bioreactor, the fusion protein was secreted in large quantities (100 mg/l per day) into the culture supernatant. From there, MUC1 could be purified to homogeneity using a two-step procedure including enterokinase cleavage and ion-exchange chromatography. Capillary liquid chromatography MS of released oligosaccharides from CHO-K1-produced MUC1 identified the main O-glycans as Galbeta1-3GalNAc (core 1) and mono- and di-sialylated core 1. The glycans occupied on average 4.3 of the five potential O-glycosylation sites in the tandem repeats, as determined by nano-liquid chromatography MS of partially deglycosylated Clostripain-digested protein. A very similar O-glycan profile and site occupancy was found in MUC1-IgG produced in the breast carcinoma cell line T47D, which has O-glycosylation typical for breast cancer. In contrast, MUC1-IgG produced in another breast cancer cell line, MCF-7, showed a more complex pattern with both core 1- and core 2-based O-glycans. This is the first reported production of large quantities of recombinant MUC1 with a breast cancer-like O-glycosylation that could be used for the immunotherapy of breast cancer. PMID:12950230

Porosome: The Universal Secretory Portal in Cells

NASA Astrophysics Data System (ADS)

Jena, Bhanu

2012-10-01

In the past 50 years it was believed that during cell secretion, membrane-bound secretory vesicles completely merge at the cell plasma membrane resulting in the diffusion of intra-vesicular contents to the cell exterior and the compensatory retrieval of the excess membrane by endocytosis. This explanation made no sense or logic, since following cell secretion partially empty vesicles accumulate as demonstrated in electron micrographs. Furthermore, with the ``all or none'' mechanism of cell secretion by complete merger of secretory vesicle membrane at the cell plasma membrane, the cell is left with little regulation and control of the amount of content release. Moreover, it makes no sense for mammalian cells to possess such `all or none' mechanism of cell secretion, when even single-cell organisms have developed specialized and sophisticated secretory machinery, such as the secretion apparatus of Toxoplasma gondii, the contractile vacuoles in paramecium, or the various types of secretory structures in bacteria. Therefore, in 1993 in a News and Views article in Nature, E. Neher wrote ``It seems terribly wasteful that, during the release of hormones and neurotransmitters from a cell, the membrane of a vesicle should merge with the plasma membrane to be retrieved for recycling only seconds or minutes later.'' This conundrum in the molecular mechanism of cell secretion was finally resolved in 1997 following discovery of the ``Porosome,'' the universal secretory machinery in cells. Porosomes are supramolecular lipoprotein structures at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to release inravesicular contents to the outside during cell secretion. In the past decade, the composition of the porosome, its structure and dynamics at nm resolution and in real time, and its functional reconstitution into artificial lipid membrane, have all been elucidated. Since porosomes in exocrine and neuroendocrine cells measure 100-180 nm, and only 20-45% increase in porosome diameter is demonstrated following the docking and fusion of 0.2-1.2 μm in diameter secretory vesicles, it is concluded that secretory vesicles ``transiently'' dock and fuse, rather than completely merge at the base of the porosome complex to release their contents to the outside. In agreement, it has been demonstrated that ``secretory granules are recaptured largely intact after stimulated exocytosis in cultured endocrine cells''; that ``single synaptic vesicles fuse transiently and successively without loss of identity''; and that``zymogen granule (the secretory vesicle in exocrine pancreas) exocytosis is characterized by long fusion pore openings and preservation of vesicle lipid identity.'' In this presentation, the discovery of the porosome, resulting in a paradigm shift in our understanding of cell secretion will be briefly discussed.

Genetic Architecture Promotes the Evolution and Maintenance of Cooperation

PubMed Central

Frénoy, Antoine; Taddei, François; Misevic, Dusan

2013-01-01

When cooperation has a direct cost and an indirect benefit, a selfish behavior is more likely to be selected for than an altruistic one. Kin and group selection do provide evolutionary explanations for the stability of cooperation in nature, but we still lack the full understanding of the genomic mechanisms that can prevent cheater invasion. In our study we used Aevol, an agent-based, in silico genomic platform to evolve populations of digital organisms that compete, reproduce, and cooperate by secreting a public good for tens of thousands of generations. We found that cooperating individuals may share a phenotype, defined as the amount of public good produced, but have very different abilities to resist cheater invasion. To understand the underlying genetic differences between cooperator types, we performed bio-inspired genomics analyses of our digital organisms by recording and comparing the locations of metabolic and secretion genes, as well as the relevant promoters and terminators. Association between metabolic and secretion genes (promoter sharing, overlap via frame shift or sense-antisense encoding) was characteristic for populations with robust cooperation and was more likely to evolve when secretion was costly. In mutational analysis experiments, we demonstrated the potential evolutionary consequences of the genetic association by performing a large number of mutations and measuring their phenotypic and fitness effects. The non-cooperating mutants arising from the individuals with genetic association were more likely to have metabolic deleterious mutations that eventually lead to selection eliminating such mutants from the population due to the accompanying fitness decrease. Effectively, cooperation evolved to be protected and robust to mutations through entangled genetic architecture. Our results confirm the importance of second-order selection on evolutionary outcomes, uncover an important genetic mechanism for the evolution and maintenance of cooperation, and suggest promising methods for preventing gene loss in synthetically engineered organisms. PMID:24278000

Intermittent subglottic secretion drainage may cause tracheal damage in patients with few oropharyngeal secretions.

PubMed

Suys, E; Nieboer, K; Stiers, W; De Regt, J; Huyghens, L; Spapen, H

2013-12-01

Injurious prolapse of tracheal mucosa into the suction port has been reported in up to 50% of intubated patients receiving continuous aspiration of subglottic secretions. We investigated whether similar injury could be inflicted by automated intermittent aspiration. Six consecutive patients, intubated with the Mallinckrodt TaperGuard Evac™ endotracheal tube, were studied. A flow sensor was placed between the vacuum regulating system and the mucus collector. Intermittent suctioning was performed at a pressure of -125 mmHg with a 25s interval and duration of 15s. After 24h, a CT scan of the tracheal region was performed. Excessive negative suction pressure, a fast drop in aspiration flow to zero, and important "swinging" movements of secretions in the evacuation line were observed in all patients. Oral instillation of antiseptic mouthwash restored normal aspiration flow and secretion mobility. CT imaging showed marked entrapment of tracheal mucosa into the suction port in all patients. In patients with few oropharyngeal secretions, automated intermittent subglottic aspiration may result in significant and potential harmful invagination of tracheal mucosa into the suction lumen. A critical amount of fluid must be present in the oropharynx to assure adequate and safe aspiration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Suppression of GH secretion in pituitary gigantism by continuous subcutaneous octreotide infusion in a pubertal boy.

PubMed

Näntö-Salonen, K; Koskinen, P; Sonninen, P; Toppari, J

1999-01-01

We describe a 12-y-old boy with excessive growth hormone and prolactin secretion presumably due to diffuse somatotroph hyperplasia. Until mid-puberty, his growth rate was under reasonable control, with high-dose octreotide injections every 8 h combined with a dopamine agonist. As his growth velocity started to increase, the efficacy of continuous s.c. octreotide infusion on GH secretion was tested. Similar total daily doses (600 microg) of octreotide were administered either by incremental s.c. injections at 8 h intervals, or by continuous s.c. infusion, two-thirds of the amount during night-time to control the presumed high nocturnal growth hormone (GH) peaks of the pubertal growth spurt. An overnight GH profile showed inadequate suppression of GH levels by incremental injections, while continuous s.c. infusion efficiently brought down the GH secretion. Another somatostatin analogue, lanreotide as a single depot injection was not effective. A 6-mo trial on the s.c. infusion regimen significantly reduced growth hormone secretion (as judged by IGF-I and IGFBP3 concentrations), and normalized growth velocity overcoming the pubertal growth spurt. It also caused a decrease in the pituitary size in magnetic resonance images. We conclude that the efficacy of octreotide infusion in suppressing GH secretion is superior to incremental injections with the same dose.

Assembly of viral particles in Xenopus oocytes: pre-surface-antigens regulate secretion of the hepatitis B viral surface envelope particle.

PubMed Central

Standring, D N; Ou, J H; Rutter, W J

1986-01-01

Infection with hepatitis B virus (HBV) is associated with the production of a viral envelope particle that contains membrane lipids, surface antigen (S), and two presurface-antigens (pre-S) comprised of the entire S moiety with approximately 55 (pre-S2) and 174 (pre-S1) additional NH2-terminal amino acids. We show here that Xenopus oocytes injected with synthetic S mRNA assemble and secrete characteristic 22-nm viral envelope particles. In contrast, pre-S1 and pre-S2 antigens are synthesized but not secreted. By coinjecting mRNAs, we found that synthesis of high levels of pre-S proteins specifically inhibits S antigen secretion. On the other hand, high levels of S synthesis can drive the secretion of small amounts of either pre-S antigen. These observations are consistent with a model for viral envelope assembly in which both S and pre-S proteins are incorporated into a multimeric particle, presumably via interactions between the S protein domains, while the pre-S amino-terminal moieties regulate the secretion of this structure. Our results indicate that Xenopus oocytes will provide a powerful system for studying the morphogenesis of simple structures of viral or cellular origin. Images PMID:3467308

Secret Sharing of a Quantum State.

PubMed

Lu, He; Zhang, Zhen; Chen, Luo-Kan; Li, Zheng-Da; Liu, Chang; Li, Li; Liu, Nai-Le; Ma, Xiongfeng; Chen, Yu-Ao; Pan, Jian-Wei

2016-07-15

Secret sharing of a quantum state, or quantum secret sharing, in which a dealer wants to share a certain amount of quantum information with a few players, has wide applications in quantum information. The critical criterion in a threshold secret sharing scheme is confidentiality: with less than the designated number of players, no information can be recovered. Furthermore, in a quantum scenario, one additional critical criterion exists: the capability of sharing entangled and unknown quantum information. Here, by employing a six-photon entangled state, we demonstrate a quantum threshold scheme, where the shared quantum secrecy can be efficiently reconstructed with a state fidelity as high as 93%. By observing that any one or two parties cannot recover the secrecy, we show that our scheme meets the confidentiality criterion. Meanwhile, we also demonstrate that entangled quantum information can be shared and recovered via our setting, which shows that our implemented scheme is fully quantum. Moreover, our experimental setup can be treated as a decoding circuit of the five-qubit quantum error-correcting code with two erasure errors.

Silks produced by insect labial glands

PubMed Central

Sutherland, Tara

2008-01-01

Insect silks are secreted from diverse gland types; this chapter deals with the silks produced by labial glands of Holometabola (insects with pupa in their life cycle). Labial silk glands are composed of a few tens or hundreds of large polyploid cells that secrete polymerizing proteins which are stored in the gland lumen as a semi-liquid gel. Polymerization is based on weak molecular interactions between repetitive amino acid motifs present in one or more silk proteins; cross-linking by disulfide bonds may be important in the silks spun under water. The mechanism of long-term storage of the silk dope inside the glands and its conversion into the silk fiber during spinning is not fully understood. The conversion occurs within seconds at ambient temperature and pressure, under minimal drawing force and in some cases under water. The silk filament is largely built of proteins called fibroins and in Lepidoptera and Trichoptera coated by glue-type proteins known as sericins. Silks often contain small amounts of additional proteins of poorly known function. The silk components controlling dope storage and filament formation seem to be conserved at the level of orders, while the nature of polymerizing motifs in the fibroins, which determine the physical properties of silk, differ at the level of family and even genus. Most silks are based on fibroin β-sheets interrupted with other structures such as α-helices but the silk proteins of certain sawflies have predominantly a collagen-like or polyglycine II arrangement and the silks of social Hymenoptera are formed from proteins in a coiled coil arrangement. PMID:19221523

Bioprinted Amniotic Fluid-Derived Stem Cells Accelerate Healing of Large Skin Wounds

PubMed Central

Skardal, Aleksander; Mack, David; Kapetanovic, Edi; Atala, Anthony; Jackson, John D.; Yoo, James

2012-01-01

Stem cells obtained from amniotic fluid show high proliferative capacity in culture and multilineage differentiation potential. Because of the lack of significant immunogenicity and the ability of the amniotic fluid-derived stem (AFS) cells to modulate the inflammatory response, we investigated whether they could augment wound healing in a mouse model of skin regeneration. We used bioprinting technology to treat full-thickness skin wounds in nu/nu mice. AFS cells and bone marrow-derived mesenchymal stem cells (MSCs) were resuspended in fibrin-collagen gel and “printed” over the wound site. At days 0, 7, and 14, AFS cell- and MSC-driven wound closure and re-epithelialization were significantly greater than closure and re-epithelialization in wounds treated by fibrin-collagen gel only. Histological examination showed increased microvessel density and capillary diameters in the AFS cell-treated wounds compared with the MSC-treated wounds, whereas the skin treated only with gel showed the lowest amount of microvessels. However, tracking of fluorescently labeled AFS cells and MSCs revealed that the cells remained transiently and did not permanently integrate in the tissue. These observations suggest that the increased wound closure rates and angiogenesis may be due to delivery of secreted trophic factors, rather than direct cell-cell interactions. Accordingly, we performed proteomic analysis, which showed that AFS cells secreted a number of growth factors at concentrations higher than those of MSCs. In parallel, we showed that AFS cell-conditioned media induced endothelial cell migration in vitro. Taken together, our results indicate that bioprinting AFS cells could be an effective treatment for large-scale wounds and burns. PMID:23197691

Establishment and characterization of a new human functional cell line from a choriocarcinoma.

PubMed

Okabe, T; Sasaki, N; Matsuzaki, M; Imai, Y; Kaneko, Y; Matsuzaki, F; Takaku, F; Tsushima, T

1983-10-01

A new human functional tumor cell line, designated as T3M-3, has been established from a xenotransplanted choriocarcinoma grown in nude mice. One of the biggest problems of the in vitro culture of these tumor cells using the xenotransplanted tumors had been the dense contamination of fibroblasts of host nude mouse origin. In the present study, these fibroblasts were completely removed by incubating the cells with antiserum raised against nude mouse spleen cells. The cell line established from the remaining tumor cells has been successfully propagated in vitro for as long as 4 years. These cells show the morphology of epithelioid cells containing a prominent nucleus with one or two large nucleoli. The cells grow in a monolayered sheet with the population-doubling time of 19 hr. The cells show perfect tumor takes when they are reinoculated into nude mice. Chromosomal analysis revealed that the cell is a human aneuploid one with a hypotriploid mode. These cultured cells maintained well the function of secreting large amounts of human chorionic gonadotropin, progesterone, and estrogen. The secretion of human chorionic gonadotropin and progesterone by these cells is enhanced by stimulation with tumor promoters, such as 12-O-tetradecanoylphorbol-13-acetate and teleocidin B, or with epidermal growth factor in a dose-and time-dependent manner. Interestingly, however, the tumor promoters did not exert a marked effect on the cellular binding of epidermal growth factor, indicating that the receptors for these reagents in T3M-3 cells are not shared by epidermal growth factor.

Ubiquitin-specific protease 8 deubiquitinates Sec31A and decreases large COPII carriers and collagen IV secretion.

PubMed

Kawaguchi, Kohei; Endo, Akinori; Fukushima, Toshiaki; Madoka, Yuka; Tanaka, Toshiaki; Komada, Masayuki

2018-05-15

Nascent cargo proteins in the endoplasmic reticulum are transported to the Golgi by COPII carriers. Typical COPII vesicles are 60-70 nm in diameter, and much larger macromolecules, such as procollagen, are transported by atypical large COPII carriers in mammalian cells. The formation of large COPII carriers is enhanced by Cul3 ubiquitin ligase, which mono-ubiquitinates Sec31A, a COPII coat protein. However, the deubiquitinating enzyme for Sec31A was unclear. Here, we show that the deubiquitinating enzyme USP8 interacts with and deubiquitinates Sec31A. The interaction was mediated by the adaptor protein STAM1. USP8 overexpression inhibited the formation of large COPII carriers. By contrast, USP8 knockdown caused the accumulation of COPII coat proteins around the cis-Golgi, promoted the intracellular trafficking of procollagen IV from the endoplasmic reticulum to the Golgi, and increased collagen IV secretion. We concluded that USP8 deubiquitinates Sec31A and inhibits the formation of large COPII carriers, thereby suppressing collagen IV secretion. Copyright © 2018 Elsevier Inc. All rights reserved.

Exploring the Secretomes of Microbes and Microbial Communities Using Filamentous Phage Display

PubMed Central

Gagic, Dragana; Ciric, Milica; Wen, Wesley X.; Ng, Filomena; Rakonjac, Jasna

2016-01-01

Microbial surface and secreted proteins (the secretome) contain a large number of proteins that interact with other microbes, host and/or environment. These proteins are exported by the coordinated activities of the protein secretion machinery present in the cell. A group of bacteriophage, called filamentous phage, have the ability to hijack bacterial protein secretion machinery in order to amplify and assemble via a secretion-like process. This ability has been harnessed in the use of filamentous phage of Escherichia coli in biotechnology applications, including screening large libraries of variants for binding to “bait” of interest, from tissues in vivo to pure proteins or even inorganic substrates. In this review we discuss the roles of secretome proteins in pathogenic and non-pathogenic bacteria and corresponding secretion pathways. We describe the basics of phage display technology and its variants applied to discovery of bacterial proteins that are implicated in colonization of host tissues and pathogenesis, as well as vaccine candidates through filamentous phage display library screening. Secretome selection aided by next-generation sequence analysis was successfully applied for selective display of the secretome at a microbial community scale, the latter revealing the richness of secretome functions of interest and surprising versatility in filamentous phage display of secretome proteins from large number of Gram-negative as well as Gram-positive bacteria and archaea. PMID:27092113

Endogenous cyclo-oxygenase activity regulates mouse gastric surface pH

PubMed Central

Baumgartner, Heidi K; Kirbiyik, Uzay; Coskun, Tamer; Chu, Shaoyou; Montrose, Marshall H

2002-01-01

In the stomach, production of prostaglandins by cyclo-oxygenase (COX) is believed to be important in mucosal defence. We tested the hypothesis that endogenous COX activity is required for protective gastric surface pH control. Intact stomachs of anaesthetized mice were perfused with a weakly buffered solution (150 mmNaCl + 4 mm Homopipes) at pH values from 2.5 to 7.0. Gastric effluents were collected to measure pH and estimate amounts of acid or alkali secretion in nanomoles secreted per minute. A switch from net acid to net alkali secretion was seen in response to acidifying luminal pH with an apparent ‘set point’ between pH 4 and 5. At luminal pH 3, the net alkali secretion (12.7 ± 2.8 nmol OH− equivalents min−1) was abolished (2.2 ± 1.7 nmol OH− min−1) by the non-specific COX inhibitor indomethacin (5 mg kg−1 I.P.). Similar inhibition was observed using a COX-1 inhibitor (SC-560; 10 mg kg−1 I.P.), but not a COX-2 inhibitor (NS-398; 10 mg kg−1 I.P.). Subsequent treatment with 16,16-dimethyl prostaglandin E2 (dm-PGE2; 1 mg kg−1 I.P.) rescued the alkali secretion (21.8 ± 2.7 nmol OH− min−1). In either the absence or presence of the H+,K+-ATPase inhibitor omeprazole (60 mg kg−1 I.P.), indomethacin blocked similar amounts of net alkali secretion (10.5 ± 2.7 and 16.4 ± 3.4 nmol OH− min−1, respectively). We also used in vivo confocal microscopy to examine pH near the mucosal surface. The gastric mucosal surface of anaesthetized mice was exposed and mucosal surface pH was imaged using the fluorescence intensity ratio of Cl-NERF as a pH indicator. Results showed a switch from a continuous net acid to net alkali secretion by the stomach in response to changing superfusate pH from 5 to 3. At luminal pH 3, the relatively alkaline surface pH (4.3 ± 0.1) was acidified (3.6 ± 0.2) by indomethacin, and subsequent dm-PGE2 restored surface pH (4.2 ± 0.2). We conclude that the pre-epithelial alkaline layer is regulated by endogenous COX activity. PMID:12411530

The metabolism of testosterone by dermal papilla cells cultured from human pubic and axillary hair follicles concurs with hair growth in 5 alpha-reductase deficiency.

PubMed

Hamada, K; Thornton, M J; Laing, I; Messenger, A G; Randall, V A

1996-05-01

Androgens regulate the growth of many human hair follicles, but only pubic, axillary, and scalp hair growth occur in men with 5 alpha-reductase deficiency. This suggests that 5 alpha-dihydrotestosterone is the active intracellular androgen in androgen-dependent follicles, except in the axilla and pubis. Since the dermal papilla plays a major regulatory role in hair follicles and may be the site of androgen action, we have investigated androgen metabolism in six primary lines of cultured dermal papilla cells from pubic and axillary hair follicles; previous studies have shown that beard cells take up and metabolize testosterone, retaining and secreting 5 alpha-dihydrotestosterone. After 24 h preincubation in serum-free Eagle's medium 199, 100-mm dishes of confluent cells were incubated for 2 h with 5 nM [1,2,6,7-3H]testosterone. Media were collected and the cells washed with phosphate-buffered saline and extracted with chloroform: methanol (2:1). After the addition of unlabeled and 14C-labeled marker steroids, the extracts were analyzed by a two-step thin-layer chromatography system; steroid identity was confirmed by recrystallization to a constant 3H/14C ratio. Beard and pubic dermal papilla cells were also incubated for 24 h, and the medium was analyzed at various times. The results from pubic and axillary primary cell lines were similar. In both cells and media the major steroid identified was testosterone, but significant amounts of androstenedione were present, indicating 17 beta-hydroxysteroid dehydrogenase activity; androstenedione was also identified within the cells, but a small amount of 5 alpha-dihydrotestosterone was only identified in one pubic cell line. Beard dermal papilla cells secreted large amounts of 5 alpha-dihydrotestosterone into the medium over 24 h in contrast to pubic cells, which produced only very small amounts. The pubic and axillary cell results contrasts with the observations of pronounced 5 alpha-dihydrotestosterone in beard cells and confirm that androgen metabolism in cultured dermal papilla cells reflects the parent follicle's ability to respond to androgen in the absence of 5 alpha-reductase type II in vivo. This supports our hypothesis that androgen acts on hair follicles via the dermal papilla and suggests that cultured dermal papilla cells may offer an important model system for studies of androgen action.

Production of Staphylococcal Enterotoxins D and R in Milk and Meat Juice by Staphylococcus aureus Strains.

PubMed

Schubert, Justyna; Podkowik, Magdalena; Bystroń, Jarosław; Bania, Jacek

2017-04-01

Seventeen Staphylococcus aureus strains were tested for production of staphylococcal enterotoxin D (SED) and staphylococcal enterotoxin R (SER) in milk and meat juice. SED was secreted in milk by 12 S. aureus strains at 6-54 ng/mL at 24 h and 9-98 ng/mL at 48 h. Another five strains secreted SED at 0.9-1.9 μg/mL at 24 h and at 1.2-2.4 μg/mL at 48 h. Strains producing high levels of SED in milk secreted 77-666 μg/mL of SED in meat juice at 24 h and 132-1225 μg/mL at 48 h. Strains producing lower amounts of SED in milk secreted 228-1109 ng/mL of SED at 24 h and 377-1782 ng/mL at 48 h in meat juice. Tested S. aureus strains produced SER in milk at 33-183 ng/mL at 24 h and 41-832 ng/mL at 48 h. Fourteen strains produced more SER in meat juice than in milk (17- to 232-fold and 15- to 269-fold more at 24 and 48 h, respectively). Three S. aureus strains secreted less than 74 ng/mL of SER in meat juice. Expression pattern of known enterotoxin regulators, that is, agrA, sarA, hld, rot, and sigB, was similar in selected strong and weak SED producers grown in both food matrices and could not explain differences in enterotoxin protein level. This suggests that enterotoxin regulation is more complex than previously thought. We demonstrated that in a number of tested S. aureus strains, production of SED and SER was significantly decreased in milk when compared with meat juice, supporting previous reports. However, certain strains secreted high amounts of SED and SER, irrespective of environment, likely contributing to higher food safety risk.

Sex pheromone in the dog.

PubMed

Goodwin, M; Gooding, K M; Regnier, F

1979-02-09

Methyl p-hydroxybenzoate has been identified in the vaginal secretions of female dogs in estrus. When small amounts of this compound were applied to the vulvas of anestrous or spayed females, males placed with these females became sexually aroused and attempted to mount them.

The action of volatile anaesthetics on stimulus-secretion coupling in bovine adrenal chromaffin cells.

PubMed Central

Pocock, G.; Richards, C. D.

1988-01-01

1. The action of four volatile anaesthetics, ethrane, halothane, isoflurane and methoxyflurane on stimulus-secretion coupling has been studied in isolated bovine adrenal medullary cells. All four agents inhibited the secretion of adrenaline and noradrenaline evoked by 500 microM carbachol at concentrations within the anaesthetic range. Total catecholamine secretion induced by stimulation with 77 mM potassium was also inhibited but at higher concentrations. All four agents inhibited the 45Ca influx evoked by stimulation with 500 microM carbachol and the 45Ca influx in response to K+-depolarization. 2. When total catecholamine secretion in response to potassium or carbachol was modulated by varying extracellular calcium or by adding halothane or methoxyflurane to the incubation medium, the amount of catecholamine secretion for a given Ca2+ entry was the same. 3. The action of methoxyflurane on the relationship between intracellular free Ca and exocytosis was examined using electropermeabilised cells, which were suspended in solutions containing a range of concentrations of ionised calcium between 10(-8) and 10(-4)M. The anaesthetic had no effect on the activation of exocytosis by intracellular free calcium. 4. Halothane and methoxyflurane inhibited the carbachol-induced secretion of catecholamines in a non-competitive manner. 5. Halothane and methoxyflurane inhibited the increase in 22Na influx evoked by carbachol. For halothane and methoxyflurane this inhibition of Na influx appears to be sufficient to account for the inhibition of the evoked catecholamine secretion. 6. We conclude that the volatile anaesthetics ethrane, halothane, isoflurane and methoxyflurane inhibit the secretion of adrenaline and noradrenaline induced by carbachol at concentrations that lie within the range encountered during general anaesthesia.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2464384

Novel Threshold Changeable Secret Sharing Schemes Based on Polynomial Interpolation

PubMed Central

Li, Mingchu; Guo, Cheng; Choo, Kim-Kwang Raymond; Ren, Yizhi

2016-01-01

After any distribution of secret sharing shadows in a threshold changeable secret sharing scheme, the threshold may need to be adjusted to deal with changes in the security policy and adversary structure. For example, when employees leave the organization, it is not realistic to expect departing employees to ensure the security of their secret shadows. Therefore, in 2012, Zhang et al. proposed (t → t′, n) and ({t1, t2,⋯, tN}, n) threshold changeable secret sharing schemes. However, their schemes suffer from a number of limitations such as strict limit on the threshold values, large storage space requirement for secret shadows, and significant computation for constructing and recovering polynomials. To address these limitations, we propose two improved dealer-free threshold changeable secret sharing schemes. In our schemes, we construct polynomials to update secret shadows, and use two-variable one-way function to resist collusion attacks and secure the information stored by the combiner. We then demonstrate our schemes can adjust the threshold safely. PMID:27792784

Novel Threshold Changeable Secret Sharing Schemes Based on Polynomial Interpolation.

PubMed

Yuan, Lifeng; Li, Mingchu; Guo, Cheng; Choo, Kim-Kwang Raymond; Ren, Yizhi

2016-01-01

After any distribution of secret sharing shadows in a threshold changeable secret sharing scheme, the threshold may need to be adjusted to deal with changes in the security policy and adversary structure. For example, when employees leave the organization, it is not realistic to expect departing employees to ensure the security of their secret shadows. Therefore, in 2012, Zhang et al. proposed (t → t', n) and ({t1, t2,⋯, tN}, n) threshold changeable secret sharing schemes. However, their schemes suffer from a number of limitations such as strict limit on the threshold values, large storage space requirement for secret shadows, and significant computation for constructing and recovering polynomials. To address these limitations, we propose two improved dealer-free threshold changeable secret sharing schemes. In our schemes, we construct polynomials to update secret shadows, and use two-variable one-way function to resist collusion attacks and secure the information stored by the combiner. We then demonstrate our schemes can adjust the threshold safely.

A fluid secretion pathway unmasked by acinar-specific Tmem16A gene ablation in the adult mouse salivary gland

PubMed Central

Catalán, Marcelo A.; Kondo, Yusuke; Peña-Munzenmayer, Gaspar; Jaramillo, Yasna; Liu, Frances; Choi, Sooji; Crandall, Edward; Borok, Zea; Flodby, Per; Shull, Gary E.; Melvin, James E.

2015-01-01

Activation of an apical Ca2+-activated Cl− channel (CaCC) triggers the secretion of saliva. It was previously demonstrated that CaCC-mediated Cl− current and Cl− efflux are absent in the acinar cells of systemic Tmem16A (Tmem16A Cl− channel) null mice, but salivation was not assessed in fully developed glands because Tmem16A null mice die within a few days after birth. To test the role of Tmem16A in adult salivary glands, we generated conditional knockout mice lacking Tmem16A in acinar cells (Tmem16A−/−). Ca2+-dependent salivation was abolished in Tmem16A−/− mice, demonstrating that Tmem16A is obligatory for Ca2+-mediated fluid secretion. However, the amount of saliva secreted by Tmem16A−/− mice in response to the β-adrenergic receptor agonist isoproterenol (IPR) was comparable to that seen in controls, indicating that Tmem16A does not significantly contribute to cAMP-induced secretion. Furthermore, IPR-stimulated secretion was unaffected in mice lacking Cftr (Cftr∆F508/∆F508) or ClC-2 (Clcn2−/−) Cl− channels. The time course for activation of IPR-stimulated fluid secretion closely correlated with that of the IPR-induced cell volume increase, suggesting that acinar swelling may activate a volume-sensitive Cl− channel. Indeed, Cl− channel blockers abolished fluid secretion, indicating that Cl− channel activity is critical for IPR-stimulated secretion. These data suggest that β-adrenergic–induced, cAMP-dependent fluid secretion involves a volume-regulated anion channel. In summary, our results using acinar-specific Tmem16A−/− mice identify Tmem16A as the Cl− channel essential for muscarinic, Ca2+-dependent fluid secretion in adult mouse salivary glands. PMID:25646474

Pulsatile insulin secretion, impaired glucose tolerance and type 2 diabetes

PubMed Central

Satin, Leslie S.; Butler, Peter C.; Ha, Joon; Sherman, Arthur S.

2015-01-01

Type 2 diabetes (T2DM) results when increases in beta cell function and/or mass cannot compensate for rising insulin resistance. Numerous studies have documented the longitudinal changes in metabolism that occur during the development of glucose intolerance and lead to T2DM. However, the role of changes in insulin secretion, both amount and temporal pattern has been understudied. Most of the insulin secreted from pancreatic beta cells of the pancreas is released in a pulsatile pattern, which is disrupted in T2DM. Here we review the evidence that changes in beta cell pulsatility occur during the progression from glucose intolerance to T2DM in humans, and contribute significantly to the etiology of the disease. We review the evidence that insulin pulsatility improves the efficacy of secreted insulin on its targets, particularly hepatic glucose production, but also examine evidence that pulsatility alters or is altered by changes in peripheral glucose uptake. Finally, we summarize our current understanding of the biophysical mechanisms responsible for oscillatory insulin secretion. Understanding how insulin pulsatility contributes to normal glucose homeostasis and is altered in metabolic disease states may help improve the treatment of T2DM. PMID:25637831

Excessive fluoride induces endoplasmic reticulum stress and interferes enamel proteinases secretion.

PubMed

Wei, Wei; Gao, Yanhui; Wang, Cheng; Zhao, Lijun; Sun, Dianjun

2013-06-01

Protein retention in the enamel layer during tooth formation is well known to be associated with dental fluorosis but the underlying mechanism is unclear. The functions of the endoplasmic reticulum (ER) correlate directly with secreted protein metabolism. We used an ameloblast-derived cell line to determine whether excessive amounts of fluoride cause ER stress, and whether this interferes with the secretion of enamel matrix proteinases. ER stress activates a signaling network called the unfolded protein response (UPR). Here, we used real-time RT-PCR and immunofluorescence to study the effect of fluoride on the expression, translation, and secretion of UPR transcription factors in ameloblast-like cells. Measurement of both the gene and protein expression of UPR transcription factors indicated that high-dose fluoride increases the expression of UPR transcription factors in a dose-dependent manner. We also used ELISA to detect and quantify the enamel proteinases secreted by ameloblasts. We found a corresponding decrease in extracellular secretion of the enamel proteinases matrix metalloproteinase-20 and kallikrein-4, after exposure to fluoride. Furthermore, correlation analysis indicated that the expression of UPR transcription factors showed a strong inverse correlation with that of enamel proteinases. The results suggest that high-dose fluoride initiates an ER stress response in ameloblasts and induces the UPR, which interferes with the synthesis and secretion of enamel proteinases. Taken together, these results suggest that excessive ingestion of fluoride during tooth formation can decrease the secretion of proteinases, thus causing protein retention in the enamel layer, indicating that the ER stress response may be responsible for dental fluorosis. Copyright © 2011 Wiley Periodicals, Inc.

Activation and desensitization of platelets by platelet-activating factor (PAF) derived from IgE-sensitized basophils. I. Characteristics of the secretory response

PubMed Central

1976-01-01

The secretion of vasoactive amines from rabbit platelets induced by the platelet-activating factor (PAF) derived from IgE-sensitized rabbit basophils, was examined. The secretion required calcium has previously been shown to be noncytotoxic and was optimal in both rate and extent at 37 degrees C and pH 7.2. Different temperature-sensitive steps were rate limiting for secretion above or below 20 degrees C. The rate of secretion was dependent upon the concentration of PAF and also of platelets. Maximal rates were observed with relatively low concentrations of platelets (2.5 X 10(8)/ml), sharply contrasting with other platelet stimuli such as C3 or thrombin. The extent of secretion was dependent upon PAF concentration until a maximum of 50 or 60% of the serotonin was released and then declined with increasing amounts of PAF. This was interpreted to result from the platelets becoming desensitized to the PAF, a process that shuts off the secretion. Such a desensitization was demonstrated and was shown to be stimulus specific, i.e., other stimuli could still induce secretion from PAF-desensitized platelets. PAF extracted with ethanol from the albumin to which it is usually bound during preparation, exhibited similar characteristics, except that secretion of up to 90% of the serotonin was induced. The extracted PAF thus seemed less able to induce the desensitization. Its use did provide important evidence that populations of rabbit platelets are relatively homogenous in their ability to respond to PAF. PMID:3618

Fluorescent Immortalized Human Adipose Derived Stromal Cells (hASCs-TS/GFP+) for Studying Cell Drug Delivery Mediated by Microvesicles.

PubMed

Cocce, Valentina; Balducci, Luigi; Falchetti, Maria L; Pascucci, Luisa; Ciusani, Emilio; Brini, Anna T; Sisto, Francesca; Piovani, Giovanna; Alessandri, Giulio; Parati, Eugenio; Cabeza, Laura; Pessina, Augusto

2017-11-24

A new tool for the drug delivery is based on the use of Mesenchymal Stromal Cells (MSCs) loaded in vitro with anti-cancer drugs. Unfortunately, the restricted lifespan of MSCs represents a significant limitation to produce them in high amounts and for long time studies. Immortalized MSCs from adipose tissue (hASCs) have been generated as good source of cells with stable features. These cells could improve the development of standardized procedures for both in vitro and preclinical studies. Furthermore they facilitate procedures for preparing large amounts of secretome containing microvesicles (MVs). We used human adipose tissue derived MSCs immortalized with hTERT+SV40 (TS) genes and transfected with GFP (hASCs-TS/GFP+). This line was investigated for its ability to uptake and release anticancer drugs. Microvesicles associated to paclitaxel (MVs/PTX) were isolated, quantified, and tested on pancreatic cancer cells. The line hASCs-TS/GFP+ maintained the main mesenchymal characters and was able to uptake and release, in active form, both paclitaxel and gemcitabine. From paclitaxel loaded hASCs-TS/GFP+ cells were isolated microvesicles in sufficient amount to inhibit "in vitro" the proliferation of pancreatic tumor cells. Our study suggests that human immortalized MSCs could be used for a large scale production of cells for mediated drug delivery. Moreover, the secretion of drug-associated MVs could represent a new way for producing new drug formulation by "biogenesis". In the context of the "advanced cell therapy procedure", the MVs/PTX production would use less resource and time and it could possibly contribute to simplification of GMP procedures. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The Legionella pneumophila global regulatory protein LetA affects DotA and Mip.

PubMed

Shi, Chunwei; Forsbach-Birk, Vera; Marre, Reinhard; McNealy, Tamara L

2006-02-01

Several genes have been identified in Legionella pneumophila which are necessary for its virulence properties. These genes include the dot/icm type IV secretion system (T4SS), mip and letA. Genes of the dot/icm system, in particular dotA, have been found to be essential for intracellular growth. The macrophage infectivity protein (Mip) is also necessary for full virulence of the bacteria. Although these genes are well characterized, the regulation of such virulence factors is not. The LetA transcriptional activator interacts with the global regulator CsrA in controlling the switch from the replicative, non-infectious to the transmissive, highly infectious form of L. pneumophila. Regulation by LetA of the dot/icm genes has also been previously postulated. Here we show that the letA mutation exerts effects not only on DotA but on a substrate of the secretion system, RalF as well. LetA was found to be necessary for full transcriptional expression of the dotA and ralF genes. Although at the transcriptional level dotA was reduced, this did not result in a decrease of DotA protein in whole cell lysates. The letA mutation, however, does result in decreased amounts of the DotA protein found in the membrane and increased amounts in the culture supernatant. Additionally, the letA mutation dramatically decreased the secretion of Mip. This work demonstrates the participation of the global regulatory protein LetA in the regulation of an essential part of the dot/icm T4SS. Also shown is the presence of secreted Mip and a decrease in this secretion in the letA(-) strain. Exactly how LetA is regulating these virulence factors remains to be elucidated but it obviously occurs at both transcriptional and post-transcriptional levels.

Secretion imbalance between tumour necrosis factor and its inhibitor in inflammatory bowel disease

PubMed Central

Noguchi, M; Hiwatashi, N; Liu, Z; Toyota, T

1998-01-01

Background—Tumour necrosis factor (TNF) α and TNF-β are soluble ligands binding to TNF receptors with similar activities; soluble TNF receptors neutralise TNF activity by acting as inhibitors. Little is known about the cytokine/soluble receptor role in inflammatory bowel disease (IBD). 
Aims—To test the hypothesis that an imbalance in secretion between TNF and TNF inhibitors plays a role in gut inflammation in patients with IBD. 
Methods—The secretion of TNF-α, TNF-β, and soluble TNF receptors was compared in the culture supernatants of colonic biopsy specimens and isolated lamina propria mononuclear cells from patients with active colonic IBD. 
Results—Spontaneous secretion of TNF-α in involved IBD mucosa was higher than in normal control and self limited colitis mucosa. Secretion of TNF-β was higher in patients with Crohn's disease than in those with ulcerative colitis. Soluble TNF receptor in IBD mucosa inhibited TNF activity. Type 2 soluble receptor release from IBD mucosa was increased in active inflammation; release from lamina propria cells was not increased. Mucosal TNF-α production correlated with severity of disease. 
Conclusions—Results showed enhanced secretion of TNF-α but failure to release enhanced amounts of soluble TNF receptor in lamina propria mononuclear cells of patients with IBD. An imbalance in secretion between TNF and TNF inhibitor may be implicated in the pathogenesis of IBD. 

 Keywords: Crohn's disease; inflammation; mucosal immunology; soluble TNF receptor; tumour necrosis factor; ulcerative colitis PMID:10189845

Proteolipidic Composition of Exosomes Changes during Reticulocyte Maturation*

PubMed Central

Carayon, Kévin; Chaoui, Karima; Ronzier, Elsa; Lazar, Ikrame; Bertrand-Michel, Justine; Roques, Véronique; Balor, Stéphanie; Terce, François; Lopez, André; Salomé, Laurence; Joly, Etienne

2011-01-01

During the orchestrated process leading to mature erythrocytes, reticulocytes must synthesize large amounts of hemoglobin, while eliminating numerous cellular components. Exosomes are small secreted vesicles that play an important role in this process of specific elimination. To understand the mechanisms of proteolipidic sorting leading to their biogenesis, we have explored changes in the composition of exosomes released by reticulocytes during their differentiation, in parallel to their physical properties. By combining proteomic and lipidomic approaches, we found dramatic alterations in the composition of the exosomes retrieved over the course of a 7-day in vitro differentiation protocol. Our data support a previously proposed model, whereby in reticulocytes the biogenesis of exosomes involves several distinct mechanisms for the preferential recruitment of particular proteins and lipids and suggest that the respective prominence of those pathways changes over the course of the differentiation process. PMID:21828046

Parathyroid hormone - Secretion and metabolism in vivo.

NASA Technical Reports Server (NTRS)

Habener, J. F.; Powell, D.; Murray, T. M.; Mayer, G. P.; Potts, J. T., Jr.

1971-01-01

Gel filtration and radioimmunoassay were used to determine the molecular size and immunochemical reactivity of parathyroid hormone present in gland extracts, in the general peripheral circulation, and in parathyroid effluent blood from patients with hyperparathyroidism, as well as from calves and from cattle. It was found that parathyroid hormone secreted from the parathyroids in man and cattle is at least as large as the molecule extracted from normal bovine glands. However, once secreted into the circulation the hormone is cleaved, and one or more fragments, immunologically, dissimilar to the originally secreted hormone, constitute the dominant form of circulating immunoreactive hormone.

A C-terminal Aldehyde Analog of the Insect Kinins Inhibits Diuresis in the Housefly

DTIC Science & Technology

2006-09-21

p e p t i d e s 2 8 ( 2 0 0 7 ) 1 4 6 – 1 5 2A C-terminal aldehyde analog of the insect kinins inhibits diuresis in the housefly Ronald J. Nachman a...secretion in crickets, but shows inhibition of both in vitro and in vivo diuresis in the housefly . R-LK-CHO reduced the total amount of urine voided over 3 h...from flies injected with 1 mL of distilled water by almost 50%. The analog not only inhibits stimulation of housefly fluid secretion by the native

Developmental co-expression of small molecular weight apolipoprotein B synthesis and triacylglycerol secretion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coleman, R.A.; Haynes, E.B.; Sand, T.M.

1987-05-01

The development of the liver's ability to coordinately express the synthesis and secretion of the two major components of very low density lipoproteins (VLDL): triacylglycerol (TG) and apolipoprotein B (apo B) was examined in cultured hepatocytes obtained from fetal, suckling and adult rats. Hepatocytes from fetal and suckling rats synthesized and secreted TG at rates lower than that displayed by adult cells. When TG synthesis was equalized by adding oleic acid to the culture medium, fetal cells still secreted only 39% as much TG as did adult cells. To determine the basis for the apparent defect in VLDL assembly/secretion displayedmore » by fetal cells, the synthesis and secretion of (TVS)methionine-labeled apo B was quantified by immunoprecipitation. Although adult and fetal cells synthesized and secreted large molecular weight apo B at similar rates, the synthesis and secretion of small molecular weight apo B was 2-fold greater in adult cells. These data suggest that the ability to assemble/secrete VLDL triacylglycerol varies in parallel with the developmental expression of small molecular weight apo B. Furthermore, these studies show the usefulness of the cultured rat hepatocyte model for examining the ontogeny and regulation of VLDL assembly/secretion.« less

A Constitutive Expression System for Cellulase Secretion in Escherichia coli and Its Use in Bioethanol Production

PubMed Central

Munjal, Neha; Jawed, Kamran; Wajid, Saima; Yazdani, Syed Shams

2015-01-01

The production of biofuels from lignocellulosic biomass appears to be attractive and viable due to the abundance and availability of this biomass. The hydrolysis of this biomass, however, is challenging because of the complex lignocellulosic structure. The ability to produce hydrolytic cellulase enzymes in a cost-effective manner will certainly accelerate the process of making lignocellulosic ethanol production a commercial reality. These cellulases may need to be produced aerobically to generate large amounts of protein in a short time or anaerobically to produce biofuels from cellulose via consolidated bioprocessing. Therefore, it is important to identify a promoter that can constitutively drive the expression of cellulases under both aerobic and anaerobic conditions without the need for an inducer. Using lacZ as reporter gene, we analyzed the strength of the promoters of four genes, namely lacZ, gapA, ldhA and pflB, and found that the gapA promoter yielded the maximum expression of the β-galactosidase enzyme under both aerobic and anaerobic conditions. We further cloned the genes for two cellulolytic enzymes, β-1,4-endoglucanase and β-1,4-glucosidase, under the control of the gapA promoter, and we expressed these genes in Escherichia coli, which secreted the products into the extracellular medium. An ethanologenic E. colistrain transformed with the secretory β-glucosidase gene construct fermented cellobiose in both defined and complex medium. This recombinant strain also fermented wheat straw hydrolysate containing glucose, xylose and cellobiose into ethanol with an 85% efficiency of biotransformation. An ethanologenic strain that constitutively secretes a cellulolytic enzyme is a promising platform for producing lignocellulosic ethanol. PMID:25768292

Compound heterozygous mutations in SLC30A2/ZnT2 results in low milk zinc concentrations: a novel mechanism for zinc deficiency in a breast-fed infant.

PubMed

Itsumura, Naoya; Inamo, Yasuji; Okazaki, Fumiko; Teranishi, Fumie; Narita, Hiroshi; Kambe, Taiho; Kodama, Hiroko

2013-01-01

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant.

De novo Analysis of the Epiphytic Transcriptome of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii and Identification of Candidate Secreted Effector Proteins

PubMed Central

Vela-Corcía, David; Bautista, Rocío; de Vicente, Antonio; Spanu, Pietro D.; Pérez-García, Alejandro

2016-01-01

The cucurbit powdery mildew fungus Podosphaera xanthii is a major limiting factor for cucurbit production worldwide. Despite the fungus’s agronomic and economic importance, very little is known about fundamental aspects of P. xanthii biology, such as obligate biotrophy or pathogenesis. To design more durable control strategies, genomic information about P. xanthii is needed. Powdery mildews are fungal pathogens with large genomes compared with those of other fungi, which contain vast amounts of repetitive DNA sequences, much of which is composed of retrotransposons. To reduce genome complexity, in this work we aimed to obtain and analyse the epiphytic transcriptome of P. xanthii as a starting point for genomic research. Total RNA was isolated from epiphytic fungal material, and the corresponding cDNA library was sequenced using a 454 GS FLX platform. Over 676,562 reads were obtained and assembled into 37,241 contigs. Annotation data identified 8,798 putative genes with different orthologues. As described for other powdery mildew fungi, a similar set of missing core ascomycete genes was found, which may explain obligate biotrophy. To gain insight into the plant-pathogen relationships, special attention was focused on the analysis of the secretome. After this analysis, 137 putative secreted proteins were identified, including 53 candidate secreted effector proteins (CSEPs). Consistent with a putative role in pathogenesis, the expression profile observed for some of these CSEPs showed expression maxima at the beginning of the infection process at 24 h after inoculation, when the primary appressoria are mostly formed. Our data mark the onset of genomics research into this very important pathogen of cucurbits and shed some light on the intimate relationship between this pathogen and its host plant. PMID:27711117

Collagen type I and III synthesis by Tenon's capsule fibroblasts in culture: individual patient characteristics and response to mitomycin C, 5-fluorouracil, and ascorbic acid.

PubMed Central

Gross, R L

1999-01-01

PURPOSE: This study was performed to better understand the differences between patients in specific components of wound healing as it may pertain to glaucoma filtration surgery, including the use of antimetabolites. METHODS: Human Tenon's capsule fibroblasts were obtained at the time of glaucoma filtering surgery and established in individual cell cultures from 35 glaucoma patients. The dose-response to 5-fluorouracil (5FU) and mitomycin C (MMC) was determined. The individual cell lines were exposed to the antimetabolites and ascorbic acid with measurement of collagen type I and III production by an ELISA-type dot blot assay. These results were then statistically compared to the individual patient characteristics including age, race, previous surgery and medications, and type of glaucoma. RESULTS: 5-FU had little effect on collagen type I and III production or protein synthesis. MMC had an inhibitory effect on collagen secretion and total protein synthesis with increasing concentration. Photomicrographs of the cells after each treatment condition revealed characteristic morphologic changes when compared to controls. There was a large range of collagen type I and III production with correlation between the amounts of each collagen type secreted in response to the antimetabolites. However, there was no correlation with accepted risk factors for filtration failure. CONCLUSION: These antimetabolites act similarly on different cell lines in a nonspecific manner. The results suggest that the increased risk of filtration failure due to age, race, diagnosis, and previous conjunctival surgery is not due to differences in secretion of collagen types I and III by Tenon's capsule fibroblasts. Images FIGURE 3 PMID:10703140

Compound Heterozygous Mutations in SLC30A2/ZnT2 Results in Low Milk Zinc Concentrations: A Novel Mechanism for Zinc Deficiency in a Breast-Fed Infant

PubMed Central

Itsumura, Naoya; Inamo, Yasuji; Okazaki, Fumiko; Teranishi, Fumie; Narita, Hiroshi; Kambe, Taiho; Kodama, Hiroko

2013-01-01

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant. PMID:23741301

Larvae of the parasitoid wasp Ampulex compressa sanitize their host, the American cockroach, with a blend of antimicrobials

PubMed Central

Herzner, Gudrun; Schlecht, Anja; Dollhofer, Veronika; Parzefall, Christopher; Harrar, Klaus; Kreuzer, Andreas; Pilsl, Ludwig; Ruther, Joachim

2013-01-01

Food resources contaminated with spoilage or pathogenic microorganisms pose severe problems to all higher organisms. Here, we describe a food-hygienic strategy of the emerald cockroach wasp Ampulex compressa. The wasp larvae develop on and inside the American cockroach Periplaneta americana, a host that can harbor various putrefactive microbes, as well as human and insect pathogens. From P. americana, we isolated the Gram-negative bacterium Serratia marcescens, which is a potent entomopathogen that can rapidly kill insect larvae. It is also known as a food contaminant and as an opportunistic human pathogen. Using behavioral observations and chemical analyses, we demonstrated that A. compressa larvae impregnate their cockroach hosts from inside with large amounts of an oral secretion containing a blend of γ-lactones and isocoumarins with (R)-(-)-mellein [(R)-(-)-3,4-diydro-8-hydroxy-3-methylisocoumarin] and micromolide [(4R,9Z)-octadec-9-en-4-olide] as dominant components. We fractionated hexane extracts of the secretion and investigated the antimicrobial properties of the fraction containing the lactones and isocoumarins, as well as of synthetic (R)-(-)-mellein and micromolide, against S. marcescens and a Gram-positive bacterium, Staphylococcus hyicus, in broth microdilution assays. The test fraction inhibited growth of both tested bacteria. The activity of the fraction against S. marcescens was explained by (R)-(-)-mellein alone, and the activity against S. hyicus was explained by the combined action of (R)-(-)-mellein and micromolide. Our data suggest that the specific combination of antimicrobials in the larval secretion provides an effective frontline defense against the unpredictable spectrum of microbes that A. compressa larvae may encounter during their development inside their cockroach hosts. PMID:23297195

De novo Analysis of the Epiphytic Transcriptome of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii and Identification of Candidate Secreted Effector Proteins.

PubMed

Vela-Corcía, David; Bautista, Rocío; de Vicente, Antonio; Spanu, Pietro D; Pérez-García, Alejandro

2016-01-01

The cucurbit powdery mildew fungus Podosphaera xanthii is a major limiting factor for cucurbit production worldwide. Despite the fungus's agronomic and economic importance, very little is known about fundamental aspects of P. xanthii biology, such as obligate biotrophy or pathogenesis. To design more durable control strategies, genomic information about P. xanthii is needed. Powdery mildews are fungal pathogens with large genomes compared with those of other fungi, which contain vast amounts of repetitive DNA sequences, much of which is composed of retrotransposons. To reduce genome complexity, in this work we aimed to obtain and analyse the epiphytic transcriptome of P. xanthii as a starting point for genomic research. Total RNA was isolated from epiphytic fungal material, and the corresponding cDNA library was sequenced using a 454 GS FLX platform. Over 676,562 reads were obtained and assembled into 37,241 contigs. Annotation data identified 8,798 putative genes with different orthologues. As described for other powdery mildew fungi, a similar set of missing core ascomycete genes was found, which may explain obligate biotrophy. To gain insight into the plant-pathogen relationships, special attention was focused on the analysis of the secretome. After this analysis, 137 putative secreted proteins were identified, including 53 candidate secreted effector proteins (CSEPs). Consistent with a putative role in pathogenesis, the expression profile observed for some of these CSEPs showed expression maxima at the beginning of the infection process at 24 h after inoculation, when the primary appressoria are mostly formed. Our data mark the onset of genomics research into this very important pathogen of cucurbits and shed some light on the intimate relationship between this pathogen and its host plant.

Larvae of the parasitoid wasp Ampulex compressa sanitize their host, the American cockroach, with a blend of antimicrobials.

PubMed

Herzner, Gudrun; Schlecht, Anja; Dollhofer, Veronika; Parzefall, Christopher; Harrar, Klaus; Kreuzer, Andreas; Pilsl, Ludwig; Ruther, Joachim

2013-01-22

Food resources contaminated with spoilage or pathogenic microorganisms pose severe problems to all higher organisms. Here, we describe a food-hygienic strategy of the emerald cockroach wasp Ampulex compressa. The wasp larvae develop on and inside the American cockroach Periplaneta americana, a host that can harbor various putrefactive microbes, as well as human and insect pathogens. From P. americana, we isolated the Gram-negative bacterium Serratia marcescens, which is a potent entomopathogen that can rapidly kill insect larvae. It is also known as a food contaminant and as an opportunistic human pathogen. Using behavioral observations and chemical analyses, we demonstrated that A. compressa larvae impregnate their cockroach hosts from inside with large amounts of an oral secretion containing a blend of γ-lactones and isocoumarins with (R)-(-)-mellein [(R)-(-)-3,4-diydro-8-hydroxy-3-methylisocoumarin] and micromolide [(4R,9Z)-octadec-9-en-4-olide] as dominant components. We fractionated hexane extracts of the secretion and investigated the antimicrobial properties of the fraction containing the lactones and isocoumarins, as well as of synthetic (R)-(-)-mellein and micromolide, against S. marcescens and a Gram-positive bacterium, Staphylococcus hyicus, in broth microdilution assays. The test fraction inhibited growth of both tested bacteria. The activity of the fraction against S. marcescens was explained by (R)-(-)-mellein alone, and the activity against S. hyicus was explained by the combined action of (R)-(-)-mellein and micromolide. Our data suggest that the specific combination of antimicrobials in the larval secretion provides an effective frontline defense against the unpredictable spectrum of microbes that A. compressa larvae may encounter during their development inside their cockroach hosts.

Defective PDI release from platelets and endothelial cells impairs thrombus formation in Hermansky-Pudlak syndrome

PubMed Central

Sharda, Anish; Kim, Sarah H.; Jasuja, Reema; Gopal, Srila; Flaumenhaft, Robert; Furie, Barbara C.

2015-01-01

Protein disulfide isomerase (PDI), secreted from platelets and endothelial cells after injury, is required for thrombus formation. The effect of platelet and endothelial cell granule contents on PDI-mediated thrombus formation was studied by intravital microscopy using a mouse model of Hermansky-Pudlak syndrome in which platelet dense granules are absent. Platelet deposition and fibrin generation were nearly absent, and extracellular PDI was significantly reduced in HPS6−/− mice after vascular injury. HPS6−/− platelets displayed impaired PDI secretion and impaired exocytosis of α granules, lysosomes, and T granules due to decreased sensitivity to thrombin, but these defects could be corrected by addition of subthreshold amounts of adenosine 5′-diphosphate (ADP). Human Hermansky-Pudlak syndrome platelets demonstrated similar characteristics. Infusion of wild-type platelets rescued thrombus formation in HPS6−/− mice. Human umbilical vein endothelial cells in which the HPS6 gene was silenced displayed impaired PDI secretion and exocytosis of Weibel-Palade bodies. Defective thrombus formation in Hermansky-Pudlak syndrome, associated with impaired exocytosis of residual granules in endothelial cells and platelets, the latter due to deficiency of ADP, is characterized by a defect in T granule secretion, a deficiency in extracellular PDI secretion, and impaired fibrin generation and platelet aggregation. Hermansky-Pudlak syndrome is an example of a hereditary disease whereby impaired PDI secretion contributes to a bleeding phenotype. PMID:25593336

Secretion profiles of fungi as potential tools for metal ecotoxicity assessment: a study of enzymatic system in Trametes versicolor.

PubMed

Lebrun, Jérémie D; Demont-Caulet, Nathalie; Cheviron, Nathalie; Laval, Karine; Trinsoutrot-Gattin, Isabelle; Mougin, Christian

2011-01-01

The relationship between the expression of extracellular enzymatic system and a metal stress is scarce in fungi, hence limiting the possible use of secretion profiles as tools for metal ecotoxicity assessment. In the present study, we investigated the effect of Zn, Cu, Pb and Cd, tested alone or in equimolar cocktail, on the secretion profiles at enzymatic and protein levels in Trametesversicolor. For that purpose, extracellular hydrolases (acid phosphatase, β-glucosidase, β-galactosidase and N-acetyl-β-glucosaminidase) and ligninolytic oxidases (laccase, Mn-peroxidase) were monitored in liquid cultures. Fungal secretome was analyzed by electrophoresis and laccase secretion was characterized by western-blot and mass spectrometry analyses. Our results showed that all hydrolase activities were inhibited by the metals tested alone or in cocktail, whereas oxidase activities were specifically stimulated by Cu, Cd and metal cocktail. At protein level, metal exposure modified the electrophoretic profiles of fungal secretome and affected the diversity of secreted proteins. Two laccase isoenzymes, LacA and LacB, identified by mass spectrometry were differentially glycosylated according to the metal exposure. The amount of secreted LacA and LacB was strongly correlated with the stimulation of laccase activity by Cu, Cd and metal cocktail. These modifications of extracellular enzymatic system suggest that fungal oxidases could be used as biomarkers of metal exposure. Copyright © 2010 Elsevier Ltd. All rights reserved.

Stimulatory effect of Coca-Cola on gastroduodenal HCO3- secretion in rats.

PubMed

Sasaki, Y; Aihara, E; Ise, F; Kita, K; Takeuchi, K

2007-10-01

We examined the effect of various carbonated beverages, especially Coca-Cola, on the HCO3- secretion in the rat stomach and duodenum. Under urethane anaesthesia, a chambered stomach or a proximal duodenal loop was perfused with saline, and HCO3- secretion was measured at pH 7.0 using a pH-stat method and by adding 2 mM HCl. The amount of CO2 contained in these beverages was about 4-7 g/mL. Coca-Cola topically applied to the mucosa for 10 min significantly increased the HCO3- secretion in both the stomach and the duodenum. The HCO3- response in the duodenum was totally abolished by indomethacin and also partially inhibited by acetazolamide, an inhibitor of carbonic anhydrase. Likewise, the response in the stomach was also markedly inhibited by either acetazolamide or indomethacin. The mucosal application of Coca-Cola increased the PGE2 contents in both the stomach and the duodenum. Other carbonated beverages, such as sparkling water, Fanta Grape or cider, also increased the HCO3- secretion in these tissues. These results suggest that Coca-Cola induces HCO3- secretion in both the stomach and the duodenum, and these responses may be attributable to both the intracellular supply of HCO3- generated via carbonic anhydrase, and endogenous PGs, probably related to the acidic pH of the solution.

Secretins revealed: structural insights into the giant gated outer membrane portals of bacteria.

PubMed

Majewski, Dorothy D; Worrall, Liam J; Strynadka, Natalie Cj

2018-03-23

The acquisition and evolution of customized and often highly complex secretion systems allows Gram-negative bacteria to efficiently passage large macromolecules across both inner and outer membranes and, in some cases, that of the infected host. Essential to the virulence and ultimate survival of the many pathogenic species that encode them, secretion systems export a wide variety of effector proteins and DNA as well as the downstream extracellular filaments of the secretion apparatus themselves. Although these customized secretion systems differ in their cytosolic and inner membrane components, several commonly rely on the secretin family of giant pores to allow these large substrates to traverse the outer membrane. Recently, several near-atomic resolution cryo-EM secretin structures have unveiled the first insights into the unique structural motifs required for outer membrane localization, assembly, hallmark ultrastable nature, spontaneous membrane insertion, and mechanism of action-including the requisite central gating needed to prevent deleterious passage of periplasmic contents to the extracellular space. Copyright © 2018. Published by Elsevier Ltd.

Water dynamics in the digestive tract of the freshwater rainbow trout during the processing of a single meal.

PubMed

Bucking, Carol; Wood, Chris M

2006-05-01

The temporal effects of feeding and digestion on chyme composition, specifically water and solid content, and net fluxes across the gastrointestinal tract, as well as plasma parameters, were examined in freshwater rainbow trout. A single meal of commercial dry pellets, incorporating ballotini beads as inert reference markers, was employed. Plasma Na+ levels increased by 15-20% at 2 h post-feeding, where Cl- levels did not change. Plasma osmolality was well regulated despite an initial chyme osmolality (775 mOsm) 2.8-fold higher than that in the blood plasma. Chyme osmolality throughout the gastrointestinal tract remained significantly higher than plasma osmolality for the duration of the 72 h period. Solid material was absorbed along the entire intestinal tract, although not in the stomach, necessitating the incorporation of an inert marker. A similar temporal pattern of transit between the ballotini beads (solid phase marker) and 3[H]-PEG 4000 (fluid phase marker), provided support for the use of ballotini beads. Large additions of water to the chyme were seen in the stomach, the largest occurring within 2 h following feeding (7.1+/-1.4 ml kg(-1)), and amounted to approximately 16 ml kg(-1) over the first 12 h. As the chyme entered the anterior intestine, a further large water secretion (3.5+/-0.5 ml kg(-1)) was seen. Thereafter the water fluxes into the chyme of the anterior intestine decreased steadily over time, but remained positive, whereas the mid-intestine exhibited net absorption of water at all time points, and the posterior intestine demonstrated little water handling at any time. The endogenous water that was secreted into the anterior intestine was absorbed along the tract, which showed a net water flux close to zero. However, assuming that the water secreted into the stomach was endogenous in nature, the processing of a single meal resulted in net loss of endogenous water (0.24 ml kg(-1) h(-1)) to the environment, a beneficial consequence of the osmotic challenge offered by the food for a freshwater hyperosmotic regulator.

Fibroblast responses and antibacterial activity of Cu and Zn co-doped TiO2 for percutaneous implants

NASA Astrophysics Data System (ADS)

Zhang, Lan; Guo, Jiaqi; Yan, Ting; Han, Yong

2018-03-01

In order to enhance skin integration and antibacterial activity of Ti percutaneous implants, microporous TiO2 coatings co-doped with different doses of Cu2+ and Zn2+ were directly fabricated on Ti via micro-arc oxidation (MAO). The structures of coatings were investigated; the behaviors of fibroblasts (L-929) as well as the response of Staphylococcus aureus (S. aureus) were evaluated. During the MAO process, a large number of micro-arc discharges forming on Ti performed as penetrating channels; O2-, Ca2+, Zn2+, Cu2+ and PO43- delivered via the channels, giving rise to the formation of doped TiO2. Surface characteristics including phase component, topography, surface roughness and wettability were almost the same for different coatings, whereas, the amount of Cu doped in TiO2 decreased with the increased Zn amount. Compared with Cu single-doped TiO2 (0.77 Wt% Cu), the co-doped with appropriate amounts of Cu and Zn, for example, 0.55 Wt% Cu and 2.53 Wt% Zn, further improved proliferation of L-929, facilitated fibroblasts to switch to fibrotic phenotype, and enhanced synthesis of collagen I as well as the extracellular collagen secretion; the antibacterial properties including contact-killing and release-killing were also enhanced. By analyzing the relationship of Cu/Zn amount in TiO2 and the behaviors of L-929 and S. aureus, it can be deduced that when the doped Zn is in a low dose (<1.79 Wt%), the behaviors of L-929 and S. aureus are sensitive to the reduced amount of Cu2+, whereas, Zn2+ plays a key role in accelerating fibroblast functions and reducing S. aureus when its dose obviously increases from 2.63 to 6.47 Wt%.

Unauthorized Disclosure: Can Behavioral Indicators Help Predict Who Will Commit Unauthorized Disclosure of Classified National Security Information?

DTIC Science & Technology

2015-06-01

Katherine Herbig, Espionage by the Numbers: A Statistical Overview, accessed April 14, 2015, http://www.wright.edu/rsp/Security/Treason/Numbers.htm 5...submitted for top-secret clearances with “derogatory financial information.”43 The debt amount reviewed was $500 in delinquency for at least 120 days, which...Investigative Service’s (DIS) “ delinquent debt criteria with amount of delinquent debt” and Defense Central Index of Investigation’s (DCII) final

Matrix Metalloproteinase-3 (MMP-3) Is an Endogenous Activator of the MMP-9 Secreted by Placental Leukocytes: Implication in Human Labor.

PubMed

Flores-Pliego, Arturo; Espejel-Nuñez, Aurora; Castillo-Castrejon, Marisol; Meraz-Cruz, Noemi; Beltran-Montoya, Jorge; Zaga-Clavellina, Veronica; Nava-Salazar, Sonia; Sanchez-Martinez, Maribel; Vadillo-Ortega, Felipe; Estrada-Gutierrez, Guadalupe

2015-01-01

The activity of matrix degrading enzymes plays a leading role in the rupture of the fetal membranes under normal and pathological human labor, and matrix metalloproteinase-9 (MMP-9) it is considered a biomarker of this event. To gain further insight into local MMP-9 origin and activation, in this study we analyzed the contribution of human placental leukocytes to MMP-9 secretion and explored the local mechanisms of the pro-enzyme activation. Placental blood leukocytes were obtained from women at term gestation without labor and maintained in culture up to 72 h. MMP-9 activity in the culture supernatants was determined by zymography and using a specific substrate. The presence of a potential pro-MMP-9 activator in the culture supernatants was monitored using a recombinant biotin-labeled human pro-MMP-9. To characterize the endogenous pro-MMP-9 activator, MMP-1, -3, -7 and -9 were measured by multiplex assay in the supernatants, and an inhibition assay of MMP-9 activation was performed using an anti-human MMP-3 and a specific MMP-3 inhibitor. Finally, production of MMP-9 and MMP-3 in placental leukocytes obtained from term pregnancies with and without labor was assessed by immunofluorescence. Placental leukocytes spontaneously secreted pro-MMP-9 after 24 h of culture, increasing significantly at 48 h (P≤0.05), when the active form of MMP-9 was detected. Culture supernatants activated the recombinant pro-MMP-9 showing that placental leukocytes secrete the activator. A significant increase in MMP-3 secretion by placental leukocytes was observed since 48 h in culture (P≤0.05) and up to 72 h (P≤0.001), when concentration reached its maximum value. Specific activity of MMP-9 decreased significantly (P≤0.005) when an anti-MMP-3 antibody or a specific MMP-3 inhibitor were added to the culture media. Placental leukocytes from term labor produced more MMP-9 and MMP-3 compared to term non-labor cells. In this work we confirm that placental leukocytes from human term pregnancies are able to secrete large amounts of MMP-9, and that the production of the enzyme it is enhanced by labor. We also demonstrate for the first time that endogenous MMP-3 plays a major role in MMP-9 activation process. These findings support the contribution of placental leukocytes to create the collagenolytic microenvironment that induces the rupture of the fetal membranes during human labor.

Cell surfaces in plant-microorganism interactions. I. A structural investigation of cell wall hydroxyproline-rich glycoproteins which accumulate in fungus-infected plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esquerre-Tugaye, M.T.; Lamport, D.T.A.

1979-08-01

Infection of muskmelon Cucumis melo seedlings by the fungus Colletotrichum lagenarium causes a 10-fold increase in the amount of cell wall hydroxyproline-rich glycoprotein. Evidence for this increase was provided by studying two specific markers of this glycoprotein, namely hydroxyproline and glycosylated serine. The lability of the O-glycosidic linkage of wall-bound glycosylated serine in the presence of hydrazine was used to determine the amount of serine which is glycosylated. A large increase in the hydroxyproline content of infected plants is shown, but the ratios of glycosylated serine to hydroxyproline are similar in healthy and infected plants. As far as these markersmore » are concerned, the hydroxyproline-rich glycoproteins secreted into the wall as a result of the disease are similar to those of healthy plants. In addition, the extent of glycosylation of the wall serine, in both healthy and infected plants, decreases as the plant ages. Serine- and hydroxyproline-rich (glyco)peptides were also isolated after trypsinolysis of the wall. These (glyco)peptides include the galactosyl-containing pentapeptide, serine-hydroxyproline. This pentapeptide is characteristic of cell wall protein.« less

Effect of swainsonine on the processing of the asparagine-linked carbohydrate chains of alpha 1-antitrypsin in rat hepatocytes. Evidence for the formation of hybrid oligosaccharides.

PubMed

Gross, V; Tran-Thi, T A; Vosbeck, K; Heinrich, P C

1983-03-25

The biosynthesis of the proteinase inhibitor alpha 1-antitrypsin has been studied in rat hepatocyte primary cultures. Newly synthesized alpha 1-antitrypsin was found in hepatocytes as a glycoprotein of an apparent molecular weight of 49,000 carrying oligosaccharide side chains of the high mannose type. In the hepatocyte medium a secreted alpha 1-antitrypsin of an apparent molecular weight of 54,000 could be identified as a glycoprotein with carbohydrate chains of the complex type. Pulse-chase experiments revealed a precursor-product relationship for the two forms of alpha 1-antitrypsin. When the hepatocytes were treated with swainsonine, an intracellular form of alpha 1-antitrypsin with an apparent molecular weight of 49,000 indistinguishable from that of control cells was found. However, the alpha 1-antitrypsin secreted from swainsonine-treated hepatocytes was different from that present in control media. It was characterized by a lower apparent molecular weight (51,000), a higher amount of [3H]mannose incorporation, half as much incorporation of [3H]galactose, and the same amount of [3H]fucose incorporation compared to alpha 1-antitrypsin of control media. In contrast to the 54,000 complex type alpha 1-antitrypsin from control media the 51,000 alpha 1-antitrypsin from the medium of swainsonine-treated cells was found to be susceptible to the action of endoglucosaminidase H, even when fucose was attached to the proximal GlcNAc residue. alpha 1-Antitrypsin secreted from swainsonine-treated cells combines features usually associated with either high mannose or complex type oligosaccharides and therefore represents a hybrid structure. In spite of its effect on the carbohydrate part of alpha 1-antitrypsin swainsonine did not impair the secretion of the incompletely processed glycoprotein.

Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas

NASA Astrophysics Data System (ADS)

Ruiz-Rodríguez, Magdalena; Møller, Anders Pape; Mousseau, Timothy A.; Soler, Juan J.

2016-10-01

Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows ( Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense capacity against bacterial infections during the 30 years since the Chernobyl disaster.

Molecular genetic and biochemical analyses of FGF23 mutations in familial tumoral calcinosis.

PubMed

Garringer, Holly J; Malekpour, Mahdi; Esteghamat, Fatemehsadat; Mortazavi, Seyed M J; Davis, Siobhan I; Farrow, Emily G; Yu, Xijie; Arking, Dan E; Dietz, Harry C; White, Kenneth E

2008-10-01

Fibroblast growth factor 23 (FGF23) is a hormone required for normal renal phosphate reabsorption. FGF23 gain-of-function mutations result in autosomal dominant hypophosphatemic rickets (ADHR), and FGF23 loss-of-function mutations cause familial hyperphosphatemic tumoral calcinosis (TC). In this study, we identified a novel recessive FGF23 TC mutation, a lysine (K) substitution for glutamine (Q) (160 C>A) at residue 54 (Q54K). To understand the molecular consequences of all known FGF23-TC mutants (H41Q, S71G, M96T, S129F, and Q54K), these proteins were stably expressed in vitro. Western analyses revealed minimal amounts of secreted intact protein for all mutants, and ELISA analyses demonstrated high levels of secreted COOH-terminal FGF23 fragments but low amounts of intact protein, consistent with TC patients' FGF23 serum profiles. Mutant protein function was tested and showed residual, yet decreased, bioactivity compared with wild-type protein. In examining the role of the FGF23 COOH-terminal tail (residues 180-251) in protein processing and activity, truncated mutants revealed that the majority of the residues downstream from the known FGF23 SPC protease site ((176)RXXR(179)/S(180)) were not required for protein secretion. However, residues adjacent to the RXXR site (between residues 188 and 202) were required for full bioactivity. In summary, we report a novel TC mutation and demonstrate a common defect of reduced FGF23 stability for all known FGF23-TC mutants. Finally, the majority of the COOH-terminal tail of FGF23 is not required for protein secretion but is required for full bioactivity.

Candida krusei form mycelia along agar surfaces towards each other and other Candida species.

PubMed

Fleischmann, Jacob; Broeckling, Corey D; Lyons, Sarah

2017-03-11

Candida krusei has been known to exhibit communal interactions such as pellicle formation and crawling out of nutritional broth. We noticed another possible interaction on agar surfaces, where C. krusei yeast cells formed mycelia along agar surfaces toward each other. We report here the results of experiments to study this interaction. When C.krusei yeast cells are plated in parallel streaks, they form mycelia along agar surfaces toward other yeasts. They also detect the presence of Candida albicans and Candida glabrata across agar surfaces, while the latter two react neither to their own kind, nor to C. krusei. Secreted molecule(s) are likely involved as C.krusei does not react to heat killed C. krusei. Timing and rate of mycelia formation across distances suggests that mycelia start forming when a secreted molecule(s) on agar surface reaches a certain concentration. We detected farnesol, tyrosol and tryptophol molecules that may be involved with mycelial formation, on the agar surfaces between yeast streaks. Unexpectedly the amounts detected between streaks were significantly higher than would have expected from additive amounts of two streaks. All three Candida species secreted these molecules. When tested on agar surface however, none of these molecules individually or combined induced mycelia formation by C. krusei. Our data confirms another communal interaction by C. krusei, manifested by formation of mycelia by yeast cells toward their own kind and other yeasts on agar surfaces. We detected secretion of farnesol, tyrosol and tryptophol by C. krusei but none of these molecules induced this activity on agar surface making it unlikely that they are the ones utilized by this yeast for this activity.

Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas.

PubMed

Ruiz-Rodríguez, Magdalena; Møller, Anders Pape; Mousseau, Timothy A; Soler, Juan J

2016-10-01

Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows (Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense capacity against bacterial infections during the 30 years since the Chernobyl disaster.

Label-free detection of protein molecules secreted from an organ-on-a-chip model for drug toxicity assays

NASA Astrophysics Data System (ADS)

Morales, Andres W.; Zhang, Yu S.; Aleman, Julio; Alerasool, Parissa; Dokmeci, Mehmet R.; Khademhosseini, Ali; Ye, Jing Yong

2016-03-01

Clinical attrition is about 30% from failure of drug candidates due to toxic side effects, increasing the drug development costs significantly and slowing down the drug discovery process. This partly originates from the fact that the animal models do not accurately represent human physiology. Hence there is a clear unmet need for developing drug toxicity assays using human-based models that are complementary to traditional animal models before starting expensive clinical trials. Organ-on-a-chip techniques developed in recent years have generated a variety of human organ models mimicking different human physiological conditions. However, it is extremely challenging to monitor the transient and long-term response of the organ models to drug treatments during drug toxicity tests. First, when an organ-on-a-chip model interacts with drugs, a certain amount of protein molecules may be released into the medium due to certain drug effects, but the amount of the protein molecules is limited, since the organ tissue grown inside microfluidic bioreactors have minimum volume. Second, traditional fluorescence techniques cannot be utilized for real-time monitoring of the concentration of the protein molecules, because the protein molecules are continuously secreted from the tissue and it is practically impossible to achieve fluorescence labeling in the dynamically changing environment. Therefore, direct measurements of the secreted protein molecules with a label-free approach is strongly desired for organs-on-a-chip applications. In this paper, we report the development of a photonic crystal-based biosensor for label-free assays of secreted protein molecules from a liver-on-a-chip model. Ultrahigh detection sensitivity and specificity have been demonstrated.

Whole-body DHA synthesis-secretion kinetics from plasma eicosapentaenoic acid and alpha-linolenic acid in the free-living rat.

PubMed

Metherel, Adam H; Domenichiello, Anthony F; Kitson, Alex P; Hopperton, Kathryn E; Bazinet, Richard P

2016-09-01

Whole body docosahexaenoic acid (DHA, 22:6n-3) synthesis from α-linolenic acid (ALA, 18:3n-3) is considered to be very low, however, the daily synthesis-secretion of DHA may be sufficient to supply the adult brain. The current study aims to assess whether whole body DHA synthesis-secretion kinetics are different when comparing plasma ALA versus eicosapentaenoic acid (EPA, 20:5n-3) as the precursor. Male Long Evans rats (n=6) were fed a 2% ALA in total fat diet for eight weeks, followed by surgery to implant a catheter into each of the jugular vein and carotid artery and 3h of steady-state infusion with a known amount of (2)H-ALA and (13)C-eicosapentaenoic acid (EPA, 20:5n3). Blood samples were collected at thirty-minute intervals and plasma enrichment of (2)H- and (13)C EPA, n-3 docosapentaenoic acid (DPAn-3, 22:5n-3) and DHA were determined for assessment of synthesis-secretion kinetic parameters. Results indicate a 13-fold higher synthesis-secretion coefficient for DHA from EPA as compared to ALA. However, after correcting for the 6.6 fold higher endogenous plasma ALA concentration, no significant differences in daily synthesis-secretion (nmol/day) of DHA (97.6±28.2 and 172±62), DPAn-3 (853±279 and 1139±484) or EPA (1587±592 and 1628±366) were observed from plasma unesterified ALA and EPA sources, respectively. These results suggest that typical diets which are significantly higher in ALA compared to EPA yield similar daily DHA synthesis-secretion despite a significantly higher synthesis-secretion coefficient from EPA. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Type-IVC Secretion System: A Novel Subclass of Type IV Secretion System (T4SS) Common Existing in Gram-Positive Genus Streptococcus

PubMed Central

Chen, Chen; Gao, George F.

2012-01-01

A growing number of pathogens are being found to possess specialized secretion systems which they use in various ways to subvert host defenses. Type IV secretion system (T4SS) is one of versatile secretion systems essential for the virulence and even survival of some bacteria species, and they enable the secretion of protein and DNA substrates across the cell envelope. T4SS was once believed to be present only in Gram-negative bacteria. In this study, we present evidence of a new subclass of T4SS, Type-IVC secretion system and indicate its common existence in the Gram-positive bacterial genus Streptococcus. We further identified that VirB1, VirB4, VirB6 and VirD4 are the minimal key components of this system. Using genome comparisons and evolutionary relationship analysis, we proposed that Type-IVC secretion system is movable via transposon factors and mediates the conjugative transfer of DNA, enhances bacterial pathogenicity, and could cause large-scale outbreaks of infections in humans. PMID:23056296

Nitric oxide-dependent neutrophil recruitment: role in nasal secretion.

PubMed

Cardell, L O; Agustí, C; Nadel, J A

2000-12-01

Leukotriene B4 (LTB4), an inflammatory mediator, is a potent chemoattractant for neutrophils that plays an important role in nasal secretion via release of elastase. Nitric oxide (NO) is an important modulator of leucocyte-endothelial cell interactions, endogenously produced in large quantities in the paranasal sinuses. To examine the role of NO in LTB4-stimulated nasal secretion. A newly-developed method for isolating and superfusing a nasal segment in dogs was used. Instillation of LTB4 into the nasal segment caused a time-dependent increase in the volume of airway fluid and in the recruitment of neutrophils. N(G)-nitro-L-arginine-methylester (L-NAME), an inhibitor of NO synthase, prevented LTB4-induced neutrophil recruitment and nasal secretion. These studies show that NO modulates LTB4-induced neutrophil recruitment and subsequent fluid secretion in the nose, and they suggest a therapeutic role for NO inhibitors in modulating neutrophil-dependent nasal secretion.

Entropy change of biological dynamics in COPD

PubMed Central

Cao, Zhixin; Sun, Baoqing; Lo, Iek Long; Liu, Tzu-Ming; Zheng, Jun; Sun, Shixue; Shi, Yan; Zhang, Xiaohua Douglas

2017-01-01

In this century, the rapid development of large data storage technologies, mobile network technology, and portable medical devices makes it possible to measure, record, store, and track analysis of large amount of data in human physiological signals. Entropy is a key metric for quantifying the irregularity contained in physiological signals. In this review, we focus on how entropy changes in various physiological signals in COPD. Our review concludes that the entropy change relies on the types of physiological signals under investigation. For major physiological signals related to respiratory diseases, such as airflow, heart rate variability, and gait variability, the entropy of a patient with COPD is lower than that of a healthy person. However, in case of hormone secretion and respiratory sound, the entropy of a patient is higher than that of a healthy person. For mechanomyogram signal, the entropy increases with the increased severity of COPD. This result should give valuable guidance for the use of entropy for physiological signals measured by wearable medical device as well as for further research on entropy in COPD. PMID:29066881

Low molecular weight compounds from Zoanthus sociatus impair insulin secretion via Ca(+2) influx blockade and cause glucose intolerance in vivo.

PubMed

Diaz-Garcia, Carlos Manlio; Sanchez-Soto, Carmen; Fuentes-Silva, Deyanira; Leon-Pinzon, Carolina; Dominguez-Perez, Dany; Varela, Carlos; Rodriguez-Romero, Adela; Castañeda, Olga; Hiriart, Marcia

2012-02-01

Cnidarians comprise a taxon with a high biodiversity of cytolitic, neurotoxic and cardiotoxic compounds, which have not been studied on insulin release. We tested the effect of a crude extract of Zoanthus sociatus (Ellis, 1767) and the low molecular weight fraction of this extract on insulin secretion in isolated rat β-cells and also in a glucose tolerance test in vivo. We observed that the extract inhibited insulin release by reducing the amount secreted by individual β-cells and also by silencing a fraction of the secreting population. This effect coincided with a diminished rise of intracellular Ca(+2) in response to high glucose and high K+ -induced depolarization. Moreover intraperitoneal administration of the low molecular weight fraction produced glucose intolerance in adult rats. The active fraction exhibited molecular weights similar to the neurotoxins described in the phylum. Our results broaden the toxic effects of cnidarian venoms and show evidence of potential modulators of voltage-gated Ca(+2) channels in this group. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multidimensional analysis of the frequencies and rates of cytokine secretion from single cells by quantitative microengraving.

PubMed

Han, Qing; Bradshaw, Elizabeth M; Nilsson, Björn; Hafler, David A; Love, J Christopher

2010-06-07

The large diversity of cells that comprise the human immune system requires methods that can resolve the individual contributions of specific subsets to an immunological response. Microengraving is process that uses a dense, elastomeric array of microwells to generate microarrays of proteins secreted from large numbers of individual live cells (approximately 10(4)-10(5) cells/assay). In this paper, we describe an approach based on this technology to quantify the rates of secretion from single immune cells. Numerical simulations of the microengraving process indicated an operating regime between 30 min-4 h that permits quantitative analysis of the rates of secretion. Through experimental validation, we demonstrate that microengraving can provide quantitative measurements of both the frequencies and the distribution in rates of secretion for up to four cytokines simultaneously released from individual viable primary immune cells. The experimental limits of detection ranged from 0.5 to 4 molecules/s for IL-6, IL-17, IFNgamma, IL-2, and TNFalpha. These multidimensional measures resolve the number and intensities of responses by cells exposed to stimuli with greater sensitivity than single-parameter assays for cytokine release. We show that cells from different donors exhibit distinct responses based on both the frequency and magnitude of cytokine secretion when stimulated under different activating conditions. Primary T cells with specific profiles of secretion can also be recovered after microengraving for subsequent expansion in vitro. These examples demonstrate the utility of quantitative, multidimensional profiles of single cells for analyzing the diversity and dynamics of immune responses in vitro and for identifying rare cells from clinical samples.

Comparative genome analysis of entomopathogenic fungi reveals a complex set of secreted proteins.

PubMed

Staats, Charley Christian; Junges, Angela; Guedes, Rafael Lucas Muniz; Thompson, Claudia Elizabeth; de Morais, Guilherme Loss; Boldo, Juliano Tomazzoni; de Almeida, Luiz Gonzaga Paula; Andreis, Fábio Carrer; Gerber, Alexandra Lehmkuhl; Sbaraini, Nicolau; da Paixão, Rana Louise de Andrade; Broetto, Leonardo; Landell, Melissa; Santi, Lucélia; Beys-da-Silva, Walter Orlando; Silveira, Carolina Pereira; Serrano, Thaiane Rispoli; de Oliveira, Eder Silva; Kmetzsch, Lívia; Vainstein, Marilene Henning; de Vasconcelos, Ana Tereza Ribeiro; Schrank, Augusto

2014-09-29

Metarhizium anisopliae is an entomopathogenic fungus used in the biological control of some agricultural insect pests, and efforts are underway to use this fungus in the control of insect-borne human diseases. A large repertoire of proteins must be secreted by M. anisopliae to cope with the various available nutrients as this fungus switches through different lifestyles, i.e., from a saprophytic, to an infectious, to a plant endophytic stage. To further evaluate the predicted secretome of M. anisopliae, we employed genomic and transcriptomic analyses, coupled with phylogenomic analysis, focusing on the identification and characterization of secreted proteins. We determined the M. anisopliae E6 genome sequence and compared this sequence to other entomopathogenic fungi genomes. A robust pipeline was generated to evaluate the predicted secretomes of M. anisopliae and 15 other filamentous fungi, leading to the identification of a core of secreted proteins. Transcriptomic analysis using the tick Rhipicephalus microplus cuticle as an infection model during two periods of infection (48 and 144 h) allowed the identification of several differentially expressed genes. This analysis concluded that a large proportion of the predicted secretome coding genes contained altered transcript levels in the conditions analyzed in this study. In addition, some specific secreted proteins from Metarhizium have an evolutionary history similar to orthologs found in Beauveria/Cordyceps. This similarity suggests that a set of secreted proteins has evolved to participate in entomopathogenicity. The data presented represents an important step to the characterization of the role of secreted proteins in the virulence and pathogenicity of M. anisopliae.

Mapping N-linked glycosylation of carbohydrate-active enzymes in the secretome of Aspergillus nidulans grown on lignocellulose.

PubMed

Rubio, Marcelo Ventura; Zubieta, Mariane Paludetti; Franco Cairo, João Paulo Lourenço; Calzado, Felipe; Paes Leme, Adriana Franco; Squina, Fabio Marcio; Prade, Rolf Alexander; de Lima Damásio, André Ricardo

2016-01-01

The genus Aspergillus includes microorganisms that naturally degrade lignocellulosic biomass, secreting large amounts of carbohydrate-active enzymes (CAZymes) that characterize their saprophyte lifestyle. Aspergillus has the capacity to perform post-translational modifications (PTM), which provides an additional advantage for the use of these organisms as a host for the production of heterologous proteins. In this study, the N-linked glycosylation of CAZymes identified in the secretome of Aspergillus nidulans grown on lignocellulose was mapped. Aspergillus nidulans was grown in glucose, xylan and pretreated sugarcane bagasse (SCB) for 96 h, after which glycoproteomics and glycomics were carried out on the extracellular proteins (secretome). A total of 265 proteins were identified, with 153, 210 and 182 proteins in the glucose, xylan and SCB substrates, respectively. CAZymes corresponded to more than 50 % of the total secretome in xylan and SCB. A total of 182 N-glycosylation sites were identified, of which 121 were detected in 67 CAZymes. A prevalence of the N-glyc sequon N-X-T (72.2 %) was observed in N-glyc sites compared with N-X-S (27.8 %). The amino acids flanking the validated N-glyc sites were mainly composed of hydrophobic and polar uncharged amino acids. Selected proteins were evaluated for conservation of the N-glyc sites in Aspergilli homologous proteins, but a pattern of conservation was not observed. A global analysis of N-glycans released from the proteins secreted by A. nidulans was also performed. While the proportion of N-glycans with Hex5 to Hex9 was similar in the xylan condition, a prevalence of Hex5 was observed in the SCB and glucose conditions. The most common and frequent N-glycosylated motifs, an overview of the N-glycosylation of the CAZymes and the number of mannoses found in N-glycans were analyzed. There are many bottlenecks in protein production by filamentous fungi, such as folding, transport by vesicles and secretion, but N-glycosylation in the correct context is a fundamental event for defining the high levels of secretion of target proteins. A comprehensive analysis of the protein glycosylation processes in A. nidulans will assist with a better understanding of glycoprotein structures, profiles, activities and functions. This knowledge can help in the optimization of heterologous expression and protein secretion in the fungal host.

Transovarial Transmission of Rickettsia spp. and Organ-Specific Infection of the Whitefly Bemisia tabaci

PubMed Central

Brumin, Marina; Levy, Maggie

2012-01-01

The whitefly Bemisia tabaci is a cosmopolitan insect pest that harbors Portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. Secondary symbionts in B. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, Rickettsia is an exception and occupies most of the body cavity, except the bacteriome. The mode of Rickettsia transfer between generations and its subcellular localization in insect organs have not been investigated. Using electron and fluorescence microscopy, we show that Rickettsia infects the digestive, salivary, and reproductive organs of the insect; however, it was not observed in the bacteriome. Rickettsia invades the oocytes during early developmental stages and resides in follicular cells and cytoplasm; it is mostly excluded when the egg matures; however, some bacterial cells remain in the egg, ensuring their transfer to subsequent generations. Rickettsia was localized to testicles and the spermatheca, suggesting a horizontal transfer between males and females during mating. The bacterium was further observed at large amounts in midgut cells, concentrating in vacuole-like structures, and was located in the hemolymph, specifically at exceptionally large amounts around bacteriocytes and in fat bodies. Organs further infected by Rickettsia included the primary salivary glands and stylets, sites of possible secretion of the bacterium outside the whitefly body. The close association between Rickettsia and the B. tabaci digestive system might be important for digestive purposes. The vertical transmission of Rickettsia to subsequent generations occurs via the oocyte and not, like other secondary symbionts, the bacteriome. PMID:22660706

Nuclear localization of Klotho in brain: an anti-aging protein

PubMed Central

German, Dwight C.; Khobahy, Ida; Pastor, Johanne; Kuro-o, Makoto; Liu, Xinran

2011-01-01

Klotho is a putative age-suppressing gene whose over-expression in mice results in extension of life span. The klotho gene encodes a single-pass transmembrane protein whose extracellular domain is shed and released into blood, urine, and cerebrospinal fluid, potentially functioning as a humoral factor. The extracellular domain of Klotho has an activity that increases the expression of anti-oxidant enzymes and confers resistance to oxidative stress in cultured cells and in whole animals. The transmembrane form of the Klotho protein directly binds to multiple fibroblast growth factor receptors and modifies their ligand affinity and specificity. The purpose of the present study was to determine the precise cellular localization of Klotho in the mouse brain. Using light microscopic immunohistochemical methods, we found the highest levels of Klotho immunoreactivity in two brain regions: the choroid plexus, and cerebellar Purkinje cells. In the choroid plexus cells, Klotho was found not only on the plasma membrane but also in large amounts near the nuclear membrane. Likewise, in the Purkinje cell Klotho was found throughout the cell including dendrites, axon and soma with large amounts near the nuclear membrane. Using immunoelectron microscopy, we found Klotho in the cell membrane, but the highest concentration was localized in the peripheral portion of the nucleus and the nucleolus in both cell types. This new finding suggests that in addition to Klotho being secreted from cells in brain, it also has a nuclear function. PMID:22245317

Engineering of a Bacillus subtilis strain with adjustable levels of intracellular biotin for secretory production of functional streptavidin.

PubMed

Wu, Sau-Ching; Wong, Sui-Lam

2002-03-01

Streptavidin is a biotin-binding protein which has been widely used in many in vitro and in vivo applications. Because of the ease of protein recovery and availability of protease-deficient strains, the Bacillus subtilis expression-secretion system is an attractive system for streptavidin production. However, attempts to produce streptavidin using B. subtilis face the problem that cells overproducing large amounts of streptavidin suffer poor growth, presumably because of biotin deficiency. This problem cannot be solved by supplementing biotin to the culture medium, as this will saturate the biotin binding sites in streptavidin. We addressed this dilemma by engineering a B. subtilis strain (WB800BIO) which overproduces intracellular biotin. The strategy involves replacing the natural regulatory region of the B. subtilis chromosomal biotin biosynthetic operon (bioWAFDBIorf2) with an engineered one consisting of the B. subtilis groE promoter and gluconate operator. Biotin production in WB800BIO is induced by gluconate, and the level of biotin produced can be adjusted by varying the gluconate dosage. A level of gluconate was selected to allow enhanced intracellular production of biotin without getting it released into the culture medium. WB800BIO, when used as a host for streptavidin production, grows healthily in a biotin-limited medium and produces large amounts (35 to 50 mg/liter) of streptavidin, with over 80% of its biotin binding sites available for future applications.

Ultra-structural study of insulin granules in pancreatic β-cells of db/db mouse by scanning transmission electron microscopy tomography.

PubMed

Xue, Yanhong; Zhao, Wei; Du, Wen; Zhang, Xiang; Ji, Gang; Ying, Wang; Xu, Tao

2012-07-01

Insulin granule trafficking is a key step in the secretion of glucose-stimulated insulin from pancreatic β-cells. The main feature of type 2 diabetes (T2D) is the failure of pancreatic β-cells to secrete sufficient amounts of insulin to maintain normal blood glucose levels. In this work, we developed and applied tomography based on scanning transmission electron microscopy (STEM) to image intact insulin granules in the β-cells of mouse pancreatic islets. Using three-dimensional (3D) reconstruction, we found decreases in both the number and the grey level of insulin granules in db/db mouse pancreatic β-cells. Moreover, insulin granules were closer to the plasma membrane in diabetic β-cells than in control cells. Thus, 3D ultra-structural tomography may provide new insights into the pathology of insulin secretion in T2D.

Toolkit for visualization of the cellular structure and organelles in Aspergillus niger.

PubMed

Buren, Emiel B J Ten; Karrenbelt, Michiel A P; Lingemann, Marit; Chordia, Shreyans; Deng, Ying; Hu, JingJing; Verest, Johanna M; Wu, Vincen; Gonzalez, Teresita J Bello; Heck, Ruben G A van; Odoni, Dorett I; Schonewille, Tom; Straat, Laura van der; Graaff, Leo H de; Passel, Mark W J van

2014-12-19

Aspergillus niger is a filamentous fungus that is extensively used in industrial fermentations for protein expression and the production of organic acids. Inherent biosynthetic capabilities, such as the capacity to secrete these biomolecules in high amounts, make A. niger an attractive production host. Although A. niger is renowned for this ability, the knowledge of the molecular components that underlie its production capacity, intercellular trafficking processes and secretion mechanisms is far from complete. Here, we introduce a standardized set of tools, consisting of an N-terminal GFP-actin fusion and codon optimized eforRed chromoprotein. Expression of the GFP-actin construct facilitates visualization of the actin filaments of the cytoskeleton, whereas expression of the chromoprotein construct results in a clearly distinguishable red phenotype. These experimentally validated constructs constitute the first set of standardized A. niger biomarkers, which can be used to study morphology, intercellular trafficking, and secretion phenomena.

Release of feruloylated oligosaccharides from wheat bran through submerged fermentation by edible mushrooms.

PubMed

Xie, Chunyan; Wu, Zhiyan; Guo, Hongzhen; Gu, Zhenxin

2014-07-01

Wheat bran, a by-product of the flour industry, is believed to be a raw material for the production of feruloylated oligosaccharides (FOs) because of its high content of conjiont ferulic acid (FA). Studies were carried out to identify edible mushrooms that are able to release FOs from wheat bran. All the six tested mushrooms (Pleurotus ostreatus, Hericium erinaceum, Auricularia auricula, Cordyceps militaris, Agrocybe chaxingu, and Ganoderma lucium) were found to release FOs, and Agrocybe chaxingu had the highest yield, reaching 35.4 µM in wheat bran broth. Enzymes detection showed that these species secreted extracellular enzymes during fermentation, including cellulase and xylanase. Agrocybe chaxingu secreted the significant amount of xylanase (180 mU ml(-1) ), which was responsible for the release of FOs from wheat bran, while Hericium erinaceum secreted FA esterase which could disassemble FOs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Urea and ammonia excretion into gastric juice in regularly dialyzed patients and patients after renal transplantation. I. Dialyzed patients.

PubMed

Skála, I; Marecková, O; Růzicková, J; Bláha, J; Straková, M; Reneltová, I; Jirka, J; Kocandrle, V; Zvolánková, K

1978-01-01

In regularly dialyzed patients in basal gastric juice and after stimulation with pentagastrin the volume of titrable acidity, urea and ammonia were assessed. It was revealed that in relation to the plasma urea concentration in basal juice the mean urea and ammonia concentration is roughly half and in stimulation juice roughly one third. The urea concentration in gastric juice is negatively correlated to the ammonia concentration. Urea excretion into the stomach depends on the plasma urea level and on the secretory gastric activity. The decisive factor of gastric secretion is probably parietal cell secretion. From the results ensues that gastric juice of dialyzed patients contains a quantitatively significant amount of urea and ammonia. Ammonia due to its neutralizing action distorts the examination of gastric acidity assessed by titration. The findings call for a revision of hitherto known data concerning gastric secretion of uraemic patients.

Functional characterization of CLE peptides from a plant-parasitic nematode Globodera rostochiensis

USDA-ARS?s Scientific Manuscript database

Plant CLAVATA3/ESR (CLE) proteins are a large family of secreted peptide ligands that play important roles in plant growth and development. Recent evidence suggests that plant-parasitic cyst nematodes secrete ligand mimics of plant CLE peptides to modify selected host root cells into multinucleate f...

Nasal lavage natural killer cell function is suppressed in smokers after live attenuated influenza virus

EPA Science Inventory

Background Modified function of immune cells in nasal secretions may playa role in the enhanced susceptibility to resp iratory viruses that is seen in smokers. Innate immune cells in nasal secretions have largely been characterized by cellular differentials using morphologic c...

The intracellular citrus huanglongbing bacterium, ‘Candidatus Liberibacter asiaticus’ encodes two novel autotransporters

USDA-ARS?s Scientific Manuscript database

Proteins secreted by the type V secretion system (T5SS), known as autotransporters, are large extracellular virulence proteins localized to the bacterial poles. In this study, we characterized two novel autotransporter proteins of ‘Candidatus Liberibacter asiaticus’ (Las), and designated them as Las...

Percolation of secret correlations in a network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leverrier, Anthony; Garcia-Patron, Raul; Research Laboratory of Electronics, MIT, Cambridge, MA 02139

In this work, we explore the analogy between entanglement and secret classical correlations in the context of large networks--more precisely, the question of percolation of secret correlations in a network. It is known that entanglement percolation in quantum networks can display a highly nontrivial behavior depending on the topology of the network and on the presence of entanglement between the nodes. Here we show that this behavior, thought to be of a genuine quantum nature, also occurs in a classical context.

Otomastoiditis caused by Sphingomonas paucimobilis: case report and literature review.

PubMed

Benevides, Gabriel Nuncio; Hein, Noely; Lo, Denise Swei; Ferronato, Angela Esposito; Ragazzi, Selma Lopes Betta; Yoshioka, Cristina Ryoka Miyao; Hirose, Maki; Cardoso, Debora Morais; Regina Dos Santos, Silvia; Gilio, Alfredo Elias

2014-01-01

Sphingomonas paucimobilis is an aerobic Gram-negative bacillus that, although rare in humans, most commonly infects immunocompromised and hospitalized patients. Among the 59 pediatric cases of S. paucimobilis infection reported in the literature, the most common diagnosis involves isolated bacteremia. These cases are related to sporadic or epidemic infections. Death related to this infection occurred in only one case. The authors report a case of an 11-year-old boy with the diagnosis of Sphingomonas paucimobilis otomastoiditis and a thorough review of the literature on this infection in pediatrics. The patient presented a 20-day history of fever, otalgia, otorrhea, and progressive retroauricular swelling with protrusion of the left ear; despite 15 days of amoxicillin regimen. His past medical history included chronic bilateral otitis media, but no cause of immunosuppression was found. A brain computed tomography scan showed left otomastoiditis associated with a large circumscribed fluid collection with deep involvement of the soft tissues of the temporal region, including the subperiosteal space. Blood tests showed neutrophilia and elevated C-reactive protein. Surgical manipulation of the cited collection drained a large amount of a fetid purulent secretion. Ceftazidime and clindamycin were empirically initiated. The outcome was favorable, with fever defervescence and resolution of the scalp deformation. Culture of the drained secretion was positive for S. paucimobilis . Ciprofloxacin was scheduled for a further 10 days after discharge. The follow-up showed complete recovery. As far as we know, this is the first case of S. paucimobilis otomastoiditis, complicated with subperiosteal abscess in an immunocompetent child. The authors call attention to the increasing number of reports on S. paucimobilis infection over the years, and therefore to the importance of this pathogen, which was previously underestimated.

Inhibitory effect of fentanyl citrate on the release of endothlin-1 induced by bradykinin in melanoma cells.

PubMed

Andoh, Tsugunobu; Shinohara, Akira; Kuraishi, Yasushi

2017-02-01

Our previous study showed that the μ-opioid receptor agonist fentanyl citrate inhibits endothelin-1-and bradykinin-mediated pain responses in mice orthotopically inoculated with melanoma cells. We also demonstrated that bradykinin induces endothelin-1 secretion in melanoma cells. However, the analgesic mechanisms of fentanyl citrate remain unclear. Thus, the present study was conducted to determine whether fentanyl citrate affects bradykinin-induced endothelin-1 secretion in B16-BL6 melanoma cells. The amount of endothelin-1 in the culture medium was measured using an enzyme immunoassay. The expression of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL/6 melanoma cells was determined using immunocytochemistry. Fentanyl citrate inhibited bradykinin-induced endothelin-1 secretion. The inhibitory effect of fentanyl citrate on the secretion of endothelin-1 was attenuated by the μ-opioid receptor antagonist naloxone methiodide. The immunoreactivities of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL6 melanoma cells were observed. These results suggest that fentanyl citrate regulates bradykinin-induced endothelin-1 secretion through μ-opioid receptors in melanoma cells. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

GARP is regulated by miRNAs and controls latent TGF-β1 production by human regulatory T cells.

PubMed

Gauthy, Emilie; Cuende, Julia; Stockis, Julie; Huygens, Caroline; Lethé, Bernard; Collet, Jean-François; Bommer, Guido; Coulie, Pierre G; Lucas, Sophie

2013-01-01

GARP is a transmembrane protein present on stimulated human regulatory T lymphocytes (Tregs), but not on other T lymphocytes (Th cells). It presents the latent form of TGF-β1 on the Treg surface. We report here that GARP favors the cleavage of the pro-TGF-β1 precursor and increases the amount of secreted latent TGF-β1. Stimulated Tregs, which naturally express GARP, and Th cells transfected with GARP secrete a previously unknown form of latent TGF-β1 that is disulfide-linked to GARP. These GARP/TGF-β1 complexes are possibly shed from the T cell surface. Secretion of GARP/TGF-β1 complexes was not observed with transfected 293 cells and may thus be restricted to the T cell lineage. We conclude that in stimulated human Tregs, GARP not only displays latent TGF-β1 at the cell surface, but also increases its secretion by forming soluble disulfide-linked complexes. Moreover, we identified six microRNAs (miRNAs) that are expressed at lower levels in Treg than in Th clones and that target a short region of the GARP 3' UTR. In transfected Th cells, the presence of this region decreased GARP levels, cleavage of pro-TGF-β1, and secretion of latent TGF-β1.

Role of the M3 muscarinic acetylcholine receptor in beta-cell function and glucose homeostasis.

PubMed

Gautam, D; Han, S-J; Duttaroy, A; Mears, D; Hamdan, F F; Li, J H; Cui, Y; Jeon, J; Wess, J

2007-11-01

The release of insufficient amounts of insulin in the presence of elevated blood glucose levels is one of the key features of type 2 diabetes. Various lines of evidence indicate that acetylcholine (ACh), the major neurotransmitter of the parasympathetic nervous system, can enhance glucose-stimulated insulin secretion from pancreatic beta-cells. Studies with isolated islets prepared from whole body M(3) muscarinic ACh receptor knockout mice showed that cholinergic amplification of glucose-dependent insulin secretion is exclusively mediated by the M(3) muscarinic receptor subtype. To investigate the physiological relevance of this muscarinic pathway, we used Cre/loxP technology to generate mutant mice that lack M(3) receptors only in pancreatic beta-cells. These mutant mice displayed impaired glucose tolerance and significantly reduced insulin secretion. In contrast, transgenic mice overexpressing M(3) receptors in pancreatic beta-cells showed a pronounced increase in glucose tolerance and insulin secretion and were resistant to diet-induced glucose intolerance and hyperglycaemia. These findings indicate that beta-cell M(3) muscarinic receptors are essential for maintaining proper insulin secretion and glucose homeostasis. Moreover, our data suggest that enhancing signalling through beta-cell M(3) muscarinic receptors may represent a new avenue in the treatment of glucose intolerance and type 2 diabetes.

Mechanisms of fluid production in smooth adhesive pads of insects

PubMed Central

Dirks, Jan-Henning; Federle, Walter

2011-01-01

Insect adhesion is mediated by thin fluid films secreted into the contact zone. As the amount of fluid affects adhesive forces, a control of secretion appears probable. Here, we quantify for the first time the rate of fluid secretion in adhesive pads of cockroaches and stick insects. The volume of footprints deposited during consecutive press-downs decreased exponentially and approached a non-zero steady state, demonstrating the presence of a storage volume. We estimated its size and the influx rate into it from a simple compartmental model. Influx was independent of step frequency. Fluid-depleted pads recovered maximal footprint volumes within 15 min. Pads in stationary contact accumulated fluid along the perimeter of the contact zone. The initial fluid build-up slowed down, suggesting that flow is driven by negative Laplace pressure. Freely climbing stick insects left hardly any traceable footprints, suggesting that they save secretion by minimizing contact area or by recovering fluid during detachment. However, even the highest fluid production rates observed incur only small biosynthesis costs, representing less than 1 per cent of the resting metabolic rate. Our results show that fluid secretion in insect wet adhesive systems relies on simple physical principles, allowing for passive control of fluid volume within the contact zone. PMID:21208970

The enteric nervous system modulates mammalian duodenal mucosal bicarbonate secretion.

PubMed

Hogan, D L; Yao, B; Steinbach, J H; Isenberg, J I

1993-08-01

Interaction of the enteric nerves in regulating mammalian duodenal mucosal bicarbonate secretion is not well understood. The purpose of the present experiments was to evaluate the role of the enteric nervous system on bicarbonate secretion from rabbit duodenal mucosa in vitro. Proximal duodenum from male New Zealand White rabbits was stripped of seromuscular layers, mounted in Ussing chambers, and studied under short-circuited conditions. Effects of electrical field stimulation, vasoactive intestinal polypeptide (VIP), carbachol, prostaglandin E2 (PGE2), dibutyryl-cyclic adenosine monophosphate (db-cAMP), and the neurotoxin tetrodotoxin (TTX) and muscarinic blockade by atropine were studied. Electrical field stimulation significantly (P < 0.01) stimulated bicarbonate secretion, short-circuit current (Isc), and electrical potential difference (PD) that was sensitive to both TTX and atropine. VIP-stimulated bicarbonate secretion was significantly inhibited by TTX (-73%), yet Isc and PD remained unchanged. Atropine decreased VIP-induced bicarbonate secretion (-69%) and Isc (-43%). Carbachol-stimulated bicarbonate secretion, Isc, and PD were abolished by atropine, whereas TTX was without affect. Neither TTX nor atropine had a significant effect on PGE2 or db-cAMP-stimulated bicarbonate secretion. These results suggest that (1) enteric nerve stimulation activates an acetylcholine receptor that in turn stimulates duodenal epithelial bicarbonate secretion; (2) VIP stimulates bicarbonate secretion, in large part, via the enteric nervous system; and (3) PGE2 and cAMP stimulate bicarbonate secretion independent of the enteric nervous system.

How great white sharks nourish their embryos to a large size: evidence of lipid histotrophy in lamnoid shark reproduction.

PubMed

Sato, Keiichi; Nakamura, Masaru; Tomita, Taketeru; Toda, Minoru; Miyamoto, Kei; Nozu, Ryo

2016-09-15

The great white shark (Carcharodon carcharias) exhibits viviparous and oophagous reproduction. A 4950 mm total length (TL) gravid female accidentally caught by fishermen in the Okinawa Prefecture, Southern Japan carried six embryos (543-624 mm TL, three in each uterus). Both uteri contained copious amounts of yellowish viscous uterine fluid (over 79.2 litres in the left uterus), nutrient eggs and broken egg cases. The embryos had yolk stomachs that had ruptured, the mean volume of which was approximately 197.9 ml. Embryos had about 20 rows of potentially functional teeth in the upper and lower jaws. Periodic acid Schiff (PAS)-positive substances were observed on the surface and in the cytoplasm of the epithelial cells, and large, secretory, OsO4-oxidized lipid droplets of various sizes were distributed on the surface of the villous string epithelium on the uterine wall. Histological examination of the uterine wall showed it to consist of villi, similar to the trophonemata of Dasyatidae rays, suggesting that the large amount of fluid found in the uterus of the white shark was likely required for embryo nutrition. We conclude that: (1) the lipid-rich fluid is secreted from the uterine epithelium only in early gestation before the onset of oophagy, (2) the embryos probably use the abundant uterine fluid and encased nutrient eggs for nutrition at this stage of their development, and (3) the uterine fluid is the major source of embryonic nutrition before oophagy onset. This is the first record of the lipid histotrophy of reproduction among all shark species. © 2016. Published by The Company of Biologists Ltd.

Analysis of the Oxidative Stress Status in Nonspecific Vaginitis and Its Role in Vaginal Epithelial Cells Apoptosis

PubMed Central

Chen, Zhaojie; Zhang, Zhen; Zhang, Haiyan; Xie, Beibei

2015-01-01

Nonspecific vaginitis (NSV), also named bacterial vaginosis, is one of the most common genital system diseases in women during their reproductive years. The specific pathogenic mechanism of NSV is not clear yet. Upon the balance alteration, large amount of reactive oxidant species (ROS) is generated and accumulated in the genital tract, and thus resulting in oxidative stress, which has been reported to be an important trigger of mitochondrial pathway cell apoptosis. In this study, the antioxidant secretion level and antioxidant enzyme activity in the vaginal discharge were evaluated to analyze the oxidative status in the vaginal tract of NSV patients. The effect of oxidative stress on the vaginal mucosa epithelial cell apoptosis was then studied. The role of oxidative stress on NSV development was uncovered; thus open new direction for the prevention and treatment of NSV by providing antiradical agents was revealed. PMID:26558281

Mechanical properties of the cement of the stalked barnacle Dosima fascicularis (Cirripedia, Crustacea)

PubMed Central

Zheden, Vanessa; Klepal, Waltraud; Gorb, Stanislav N.; Kovalev, Alexander

2015-01-01

The stalked barnacle Dosima fascicularis secretes foam-like cement, the amount of which usually exceeds that produced by other barnacles. When Dosima settles on small objects, this adhesive is additionally used as a float which gives buoyancy to the animal. The dual use of the cement by D. fascicularis requires mechanical properties different from those of other barnacle species. In the float, two regions with different morphological structure and mechanical properties can be distinguished. The outer compact zone with small gas-filled bubbles (cells) is harder than the interior one and forms a protective rind presumably against mechanical damage. The inner region with large, gas-filled cells is soft. This study demonstrates that D. fascicularis cement is soft and visco-elastic. We show that the values of the elastic modulus, hardness and tensile stress are considerably lower than in the rigid cement of other barnacles. PMID:25657833

Improvement of heterologous protein production in Aspergillus oryzae by RNA interference with alpha-amylase genes.

PubMed

Nemoto, Takashi; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

2009-11-01

Aspergillus oryzae RIB40 has three alpha-amylase genes (amyA, amyB, and amyC), and secretes alpha-amylase abundantly. However, large amounts of endogenous secretory proteins such as alpha-amylase can compete with heterologous protein in the secretory pathway and decrease its production yields. In this study, we examined the effects of suppression of alpha-amylase on heterologous protein production in A. oryzae, using the bovine chymosin (CHY) as a reporter heterologous protein. The three alpha-amylase genes in A. oryzae have nearly identical DNA sequences from those promoters to the coding regions. Hence we performed silencing of alpha-amylase genes by RNA interference (RNAi) in the A. oryzae CHY producing strain. The silenced strains exhibited a reduction in alpha-amylase activity and an increase in CHY production in the culture medium. This result suggests that suppression of alpha-amylase is effective in heterologous protein production in A. oryzae.

[Physical activity and exercise training in the prevention and therapy of type 2 diabetes mellitus].

PubMed

Francesconi, Claudia; Lackinger, Christian; Weitgasser, Raimund; Haber, Paul; Niebauer, Josef

2016-04-01

Lifestyle in general (nutrition, exercise, smoking habits), besides the genetic predisposition, is known to be a strong predictor for the development of diabetes. Exercise in particular is not only useful in improving glycaemia by lowering insulin resistance and positively affect insulin secretion, but to reduce cardiovascular risk.To gain substantial health benefits a minimum of 150 min of moderate or vigorous intense aerobic physical activity and muscle strengthening activities per week are needed. The positive effect of training correlates directly with the amount of fitness gained and lasts only as long as the fitness level is sustained. The effect of exercise is independent of age and gender. It is reversible and reproducible.Based on the large evidence of exercise referral and prescription the Austrian Diabetes Associations aims to implement the position of a "physical activity adviser" in multi-professional diabetes care.

CD4+ T helper 2 cells – microbial triggers, differentiation requirements and effector functions

PubMed Central

Okoye, Isobel S; Wilson, Mark S

2011-01-01

Over the past 10 years we have made great strides in our understanding of T helper cell differentiation, expansion and effector functions. Within the context of T helper type 2 (Th2) cell development, novel innate-like cells with the capacity to secrete large amounts of interleukin-5 (IL-5), IL-13 and IL-9 as well as IL-4-producing and antigen-processing basophils have (re)-emerged onto the type 2 scene. To what extent these new players influence αβ+ CD4+ Th2 cell differentiation is discussed throughout this appraisal of the current literature. We highlight the unique features of Th2 cell development, highlighting the three necessary signals, T-cell receptor ligation, co-stimulation and cytokine receptor ligation. Finally, putting these into context, microbial and allergenic properties that trigger Th2 cell differentiation and how these influence Th2 effector function are discussed and questioned. PMID:22043920

A Protein Chimera Strategy Supports Production of a Model "Difficult-to-Express" Recombinant Target.

PubMed

Hussain, Hirra; Fisher, David I; Roth, Robert G; Abbott, W Mark; Carballo-Amador, Manuel Alejandro; Warwicker, Jim; Dickson, Alan J

2018-06-22

Due in part to the needs of the biopharmaceutical industry, there has been an increased drive to generate high quality recombinant proteins in large amounts. However, achieving high yields can be a challenge as the novelty and increased complexity of new targets often makes them 'difficult-to-express'. This study aimed to define the molecular features that restrict the production of a model 'difficult-to-express' recombinant protein, Tissue Inhibitor Metalloproteinase-3 (TIMP-3). Building from experimental data, computational approaches were used to rationalise the re-design of this recombinant target to generate a chimera with enhanced secretion. The results highlight the importance of early identification of unfavourable sequence attributes, enabling the generation of engineered protein forms that bypass 'secretory' bottlenecks and result in efficient recombinant protein production. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The s29x gene of symbiotic bacteria in Amoeba proteus with a novel promoter.

PubMed

Pak, J W; Jeon, K W

1996-05-24

Gram-symbiotic bacteria (called X-bacteria), present in the xD strain of Amoeba proteus as required cell components, synthesize and export a large amount of a 29-kDa protein, S29x. S29x is exported into the host's cytoplasm across the bacterial membranes and the symbiosome membrane. The complete nucleotide (nt) sequence of the s29x gene of X-bacteria has been determined, and the promoter sequence and tsp have also been identified. The gene has a nonconventional promoter with putative nt sequences different from the known consensus sequences. When Escherichia coli cells are transformed with s29x, the gene is expressed and the product is secreted into the culture medium. Functions of S29x are not fully known, but it is suspected that S29x plays an important role in the symbiotic relationship between amoebae and X-bacteria.

Identification of a Gene Cluster for Biosynthesis of Mannosylerythritol Lipids in the Basidiomycetous Fungus Ustilago maydis

PubMed Central

Hewald, Sandra; Linne, Uwe; Scherer, Mario; Marahiel, Mohamed A.; Kämper, Jörg; Bölker, Michael

2006-01-01

Many microorganisms produce surface-active substances that enhance the availability of water-insoluble substrates. Although many of these biosurfactants have interesting potential applications, very little is known about their biosynthesis. The basidiomycetous fungus Ustilago maydis secretes large amounts of mannosylerythritol lipids (MELs) under conditions of nitrogen starvation. We recently described a putative glycosyltransferase, Emt1, which is essential for MEL biosynthesis and whose expression is strongly induced by nitrogen limitation. We used DNA microarray analysis to identify additional genes involved in MEL biosynthesis. Here we show that emt1 is part of a gene cluster which comprises five open reading frames. Three of the newly identified proteins, Mac1, Mac2, and Mat1, contain short sequence motifs characteristic for acyl- and acetyltransferases. Mutational analysis revealed that Mac1 and Mac2 are essential for MEL production, which suggests that they are involved in the acylation of mannosylerythritol. Deletion of mat1 resulted in the secretion of completely deacetylated MELs, as determined by mass spectrometry. We overexpressed Mat1 in Escherichia coli and demonstrated that this enzyme acts as an acetyl coenzyme A-dependent acetyltransferase. Remarkably, Mat1 displays relaxed regioselectivity and is able to acetylate mannosylerythritol at both the C-4 and C-6 hydroxyl groups. Based on these results, we propose a biosynthesis pathway for the generation of mannosylerythritol lipids in U. maydis. PMID:16885300

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study.

PubMed

Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

2018-01-01

Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger . This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger , we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi.

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

PubMed Central

Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

2018-01-01

Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi. PMID:29623069

[Culture of pancreatic progenitor cells in hanging drop and on floating filter].

PubMed

Ma, Feng-xia; Chen, Fang; Chi, Ying; Yang, Shao-guang; Lu, Shi-hong; Han, Zhong-chao

2013-06-01

To construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method. Murine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR). One day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose. In hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

A novel subset of helper T cells promotes immune responses by secreting GM-CSF

PubMed Central

Zhang, J; Roberts, A I; Liu, C; Ren, G; Xu, G; Zhang, L; Devadas, S; Shi, Yufang

2013-01-01

Helper T cells are crucial for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte macrophage-colony-stimulating factor (GM-CSF). By depleting major cytokines during the differentiation of CD4+ T cells in vitro, we derived cells that were found to produce large amounts of GM-CSF, but little of the cytokines produced by other helper T subsets. By their secretion of GM-CSF, this novel subset of helper T cells (which we have termed ThGM cells) promoted the production of cytokines by other T-cell subtypes, including type 1 helper T cell (Th1), type 2 helper T cell (Th2), type 1 cytotoxic T cell (Tc1), type 2 cytotoxic T cell (Tc2), and naive T cells, as evidenced by the fact that antibody neutralization of GM-CSF abolished this effect. ThGM cells were found to be highly prone to activation-induced cell death (AICD). Inhibitors of TRAIL or granzymes could not block AICD in ThGM cells, whereas inhibition of FasL/Fas interaction partially rescued ThGM cells from AICD. Thus, ThGM cells are a novel subpopulation of T helper cells that produce abundant GM-CSF, exhibit exquisite susceptibility to apoptosis, and therefore play a pivotal role in the regulation of the early stages of immune responses. PMID:24076588

Targeting the Intratumoral Dendritic Cells by the Oncolytic Adenoviral Vaccine Expressing RANTES Elicits Potent Antitumor Immunity

PubMed Central

Lapteva, Natalia; Aldrich, Melissa; Weksberg, David; Rollins, Lisa; Goltsova, Tatiana; Chen, Si-Yi; Huang, Xue F.

2014-01-01

Summary Dendritic cells (DCs) are professional antigen (Ag)-presenting cells capable of inducing immune responses to tumor Ags and, therefore, play a central role in the induction of antitumor immunity. There is a large amount of evidence, however, about paucity of tumor-associated DCs and that DCs’ immunogenic functions are suppressed in a tumor environment. Here we describe a potent in situ vaccine targeting tumoral DCs in vivo. This vaccine comprised of an oncolytic adenovirus expressing RANTES (regulated upon activation, normally T expressed, and presumably secreted) (Ad-RANTES-E1A), enhanced tumor infiltration, and maturation of Ag-presenting cells in vivo. In this study, we show that intratumoral vaccinations with Ad-RANTES-E1A induced significant primary tumor growth regression and blocked metastasis formation in JC and E.G-7 murine tumor models. This vaccine recruited DCs, macrophages, natural killer cells, and CD8+ T cells to the tumor site, and thus enhanced Ag-specific cytotoxic T lymphocyte responses and natural killer cell responses. DCs purified from the Ad-RANTES-E1A–treated E.G-7 tumors secreted significantly higher levels of interferon-γ and interleukin-12, as compared with control groups and more efficiently enhanced CD8+ T-cell response. This in situ immunization strategy could be a potent antitumor immunotherapy approach for aggressive established tumors. PMID:19238013

Efficient production of glycosylated Cypridina luciferase using plant cells.

PubMed

Mitani, Yasuo; Oshima, Yoshimi; Mitsuda, Nobutaka; Tomioka, Azusa; Sukegawa, Masako; Fujita, Mika; Kaji, Hiroyuki; Ohmiya, Yoshihiro

2017-05-01

Cypridina noctiluca luciferase has been utilized for biochemical and molecular biological applications, including bioluminescent enzyme immunoassays, far-red luminescence imaging, and high-throughput reporter assays. Some of these applications require a large amount of purified luciferase. However, conventional protein expression systems are not capable of producing sufficient quantities of protein with a high quality and purity without laborious and costly purification processes. To improve the productivity and expand the breadth of possibilities for Cypridina luciferase applications, we employed a variety of secretion expression systems, including yeast, mammalian cells, and silk worms. In this study, we established a simple production procedure using plant cell cultures. The plant cell culture BY-2 efficiently secreted luciferase, which was easily purified using a simple one-step ion-exchange chromatography method. The production yield was 20-30 mg of luciferase per liter of culture medium, and its Km for the luciferin (0.45 μM) was similar to that of the native protein. Additionally, we characterized its glycosylation pattern and confirmed that the two potential N-glycosylation sites were modified with plant-type oligosaccharide chains. Interestingly, the oligosaccharide chains could be trimmed without any detectable decrease in recombinant protein activity. Therefore, the results of our study indicate that this method offers a more cost-effective production method for Cypridina luciferase than conventional methods. Copyright © 2017 Elsevier Inc. All rights reserved.

High level heterologous protein production in Lactococcus and Lactobacillus using a new secretion system based on the Lactobacillus brevis S-layer signals.

PubMed

Savijoki, K; Kahala, M; Palva, A

1997-02-28

A secretion cassette, based on the expression and secretion signals of a S-layer protein (SlpA) from Lactobacillus brevis, was constructed. E. coli beta-lactamase (Bla) was used as the reporter protein to determine the functionality of the S-layer signals for heterologous expression and secretion in Lactococcus lactis, Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus gasseri and Lactobacillus casei using a low-copy-number plasmid derived from pGK12. In all hosts tested, the bla gene was expressed under the slpA signals and all Bla activity was secreted to the culture medium. The Lb. brevis S-layer promoters were very efficiently recognized in L. lactis, Lb. brevis and Lb. plantarum, whereas in Lb. gasseri the slpA promoter region appeared to be recognized at a lower level and in Lb. casei the level of transcripts was below the detection limit. The production of Bla was mainly restricted to the exponential phase of growth. The highest yield of Bla was obtained with L. lactis and Lb. brevis. Without pH control, substantial degradation of Bla occurred during prolonged cultivations with all lactic acid bacteria (LAB) tested. When growing L. lactis and Lb. brevis under pH control, the Bla activity could be stabilized also at the stationary phase. L. lactis produced up to 80 mg/l of Bla which to our knowledge represents the highest amount of a heterologous protein secreted by LAB so far. The short production phase implied a very high rate of secretion with a calculated value of 5 x 10(5) Bla molecules/cell per h. Such a high rate was also observed with Lb. plantarum, whereas in Lb. brevis the competition between the wild type slpA gene and the secretion construct probably lowered the rate of Bla production. The results obtained indicate wide applicability of the Lb. brevis slpA signals for efficient protein production and secretion in LAB.

Hyperthyroidism

PubMed Central

Sharma, Mala; Aronow, Wilbert S.; Patel, Laxesh; Gandhi, Kaushang; Desai, Harit

2011-01-01

Summary Hyperthyroidism is a pathological syndrome in which tissue is exposed to excessive amounts of circulating thyroid hormone. The most common cause of this syndrome is Graves’ disease, followed by toxic multinodular goitre, and solitary hyperfunctioning nodules. Autoimmune postpartum and subacute thyroiditis, tumors that secrete thyrotropin, and drug-induced thyroid dysfunction, are also important causes. PMID:21455118

Compressed Secret Key Agreement:Maximizing Multivariate Mutual Information per Bit

NASA Astrophysics Data System (ADS)

Chan, Chung

2017-10-01

The multiterminal secret key agreement problem by public discussion is formulated with an additional source compression step where, prior to the public discussion phase, users independently compress their private sources to filter out strongly correlated components for generating a common secret key. The objective is to maximize the achievable key rate as a function of the joint entropy of the compressed sources. Since the maximum achievable key rate captures the total amount of information mutual to the compressed sources, an optimal compression scheme essentially maximizes the multivariate mutual information per bit of randomness of the private sources, and can therefore be viewed more generally as a dimension reduction technique. Single-letter lower and upper bounds on the maximum achievable key rate are derived for the general source model, and an explicit polynomial-time computable formula is obtained for the pairwise independent network model. In particular, the converse results and the upper bounds are obtained from those of the related secret key agreement problem with rate-limited discussion. A precise duality is shown for the two-user case with one-way discussion, and such duality is extended to obtain the desired converse results in the multi-user case. In addition to posing new challenges in information processing and dimension reduction, the compressed secret key agreement problem helps shed new light on resolving the difficult problem of secret key agreement with rate-limited discussion, by offering a more structured achieving scheme and some simpler conjectures to prove.

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity

PubMed Central

1984-01-01

The processing of asparagine-linked oligosaccharides on the alpha- chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N- acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin. PMID:6420419

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity.

PubMed

Hickman, S; Theodorakis, J L; Greco, J M; Brown, P H

1984-02-01

The processing of asparagine-linked oligosaccharides on the alpha-chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N-acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin.

Transcriptomic analyses of the secreted proteins from the salivary glands of the wheat midge larvae

USDA-ARS?s Scientific Manuscript database

Both the wheat midge (Sitodiplosis mosellana) and the Hessian fly (Mayetiola destructor) belong to a group of insects called gall midges (Diptera: Cecidomyiidae) and both are destructive pests of wheat. From Hessian fly larvae, a large number of genes have been identified to encode Secreted Salivary...

Nutritional regulation of LH secretion in gilts: Hypothalamic expression of kisspeptin and neurokinin B

USDA-ARS?s Scientific Manuscript database

Puberty, brought about by changes in LH pulse frequency and amplitude, is metabolically gated in the pig. How nutrition regulates LH secretion to initiate puberty in gilts is largely unknown. Kisspeptin (Kiss1) and neurokinin B (NKB) are neuropeptides that have been implicated in regulating LH pulsa...

Virulence from vesicles: Novel mechanisms of host cell injury by Escherichia coli O104:H4 outbreak strain

USDA-ARS?s Scientific Manuscript database

The highly virulent Escherichia coli O104:H4 that caused the large 2011 outbreak of diarrhoea and haemolytic uraemic syndrome secretes blended virulence factors of enterohaemorrhagic and enteroaggregative E. coli, but their secretion pathways are unknown. We demonstrate that the outbreak strain rele...

The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex.

PubMed

Yang, Guowei; Waterfield, Nicholas R

2013-01-01

The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5∶1∶1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man.

MEK-ERK inhibition corrects the defect in VLDL assembly in HepG2 cells: potential role of ERK in VLDL-ApoB100 particle assembly.

PubMed

Tsai, Julie; Qiu, Wei; Kohen-Avramoglu, Rita; Adeli, Khosrow

2007-01-01

Hepatic VLDL assembly is defective in HepG2 cells, resulting in the secretion of immature triglyceride-poor LDL-sized apoB particles. We investigated the mechanisms underlying defective VLDL assembly in HepG2 and have obtained evidence implicating the MEK-ERK pathway. HepG2 cells exhibited considerably higher levels of the ERK1/2 mass and activity compared with primary hepatocytes. Inhibition of ERK1/2 using the MEK1/MEK2 inhibitor, U0126 (but not the inactive analogue) led to a significant increase in apoB secretion. In the presence of oleic acid, ERK1/2 inhibition caused a major shift in the lipoprotein distribution with a majority of particles secreted as VLDL, an effect independent of insulin. In contrast, overexpression of constitutively active MEK1 decreased apoB and large VLDL secretion. MEK1/2 inhibition significantly increased both cellular and microsomal TG mass, and mRNA levels for DGAT-1 and DGAT-2. In contrast to ERK, modulation of the PI3-K pathway or inhibition of the p38 MAP kinase, had no effect on lipoprotein density profile. Modulation of the MEK-ERK pathway in primary hamster hepatocytes led to changes in apoB secretion and altered the density profile of apoB-containing lipoproteins. Inhibition of the overactive ras-MEK-ERK pathway in HepG2 cells can correct the defect in VLDL assembly leading to the secretion of large, VLDL-sized particles, similar to primary hepatocytes, implicating the MEK-ERK cascade in VLDL assembly in the HepG2 model. Modulation of this pathway in primary hepatocytes also regulates apoB secretion and appears to alter the formation of VLDL-1 sized particles.

Pulsatile LH secretion and ovarian follicular wave emergence and growth in anestrous ewes.

PubMed

Seekallu, Srinivas V; Barrett, David M W; Toosi, Behzad M; Clarke, Kelsey; Ewen, Kirk A; Duggavathi, Rajesha; Davies, Kate L; Pattullo, Kim M; Bagu, Edward T; Rawlings, Norman C

2010-10-01

The objective of this study was to determine if pulsatile LH secretion was needed for ovarian follicular wave emergence and growth in the anestrous ewe. In Experiment 1, ewes were either large or small (10 x 0.47 or 5 x 0.47 cm, respectively; n = 5/group) sc implants releasing estradiol-17 beta for 10 d (Day 0 = day of implant insertion), to suppress pulsed LH secretion, but not FSH secretion. Five sham-operated control ewes received no implants. In Experiment 2, 12 ewes received large estradiol-releasing implants for 12 d (Day 0 = day of implant insertion); six were given GnRH (200 ng IV) every 4 h for the last 6 d that the implants were in place (to reinitiate pulsed LH secretion) whereas six Control ewes were given saline. Ovarian ultrasonography and blood sampling were done daily; blood samples were also taken every 12 min for 6 h on Days 5 and 9, and on Days 6 and 12 of the treatment period in Experiments 1 and 2, respectively. Treatment with estradiol blocked pulsatile LH secretion (P < 0.001). In Experiment 1, implant treatment halted follicular wave emergence between Days 2 and 10. In Experiment 2, follicular waves were suppressed during treatment with estradiol, but resumed following GnRH treatment. In both experiments, the range of peaks in serum FSH concentrations that preceded and triggered follicular wave emergence was almost the same as control ewes and those given estradiol implants alone or with GnRH; mean concentrations did not differ (P < 0.05). We concluded that some level of pulsatile LH secretion was required for the emergence of follicular waves that were triggered by peaks in serum FSH concentrations in the anestrous ewe. (c) 2010 Elsevier Inc. All rights reserved.

Effects of ANP receptor antagonists on ANP secretion from adult rat cultured atrial myocytes.

PubMed

Nachshon, S; Zamir, O; Matsuda, Y; Zamir, N

1995-03-01

Atrial natriuretic peptide (ANP) is a hormone-secreted predominantly by atrial myocytes. ANP exerts many of its actions via activation of the particulate guanylyl cyclase receptor ANPR-A and the formation of guanosine 3',5'-cyclic monophosphate (cGMP), which serves as a second messenger in the target cells. Using membrane-permeable cGMP analogues (8-bromo-cGMP and dibutyryl- cGMP), we first tested the hypothesis that ANP secretion by adult rat cultured atrial myocytes can be modulated through the second messenger cGMP. Second, we examined the effects of two competitive ANPR-A receptor antagonists, namely HS-142-1 and anantin, on cGMP formation and ANP secretion from cultured atrial myocytes. Cultured atrial myocytes secreted large quantities of immunoreactive (ir) ANP under basal conditions. We found that cGMP analogues inhibited basal irANP secretion from cultured atrial myocytes, whereas HS-142-1 and anantin had stimulating effects. HS-142-1 and anantin reduced cGMP formation in cultured atrial myocytes at basal conditions. These results suggest an autoregulatory mechanism of ANP secretion by atrial myocytes in an autocrine/paracrine fashion.

Siderophore production and the evolution of investment in a public good: An adaptive dynamics approach to kin selection.

PubMed

Lee, William; van Baalen, Minus; Jansen, Vincent A A

2016-01-07

Like many other bacteria, Pseudomonas aeruginosa sequesters iron from the environment through the secretion, and subsequent uptake, of iron-binding molecules. As these molecules can be taken up by other bacteria in the population than those who secreted them, this is a form of cooperation through a public good. Traditionally, this problem has been studied by comparing the relative fitnesses of siderophore-producing and non-producing strains, but this gives no information about the fate of strains that do produce intermediate amounts of siderophores. Here, we investigate theoretically how the amount invested in this form of cooperation evolves. We use a mechanistic description of the laboratory protocols used in experimental evolution studies to describe the competition and cooperation of the bacteria. From this dynamical model we derive the fitness following the adaptive dynamics method. The results show how selection is driven by local siderophore production and local competition. Because siderophore production reduces the growth rate, local competition decreases with the degree of relatedness (which is a dynamical variable in our model). Our model is not restricted to the analysis of small phenotypic differences and allows for theoretical exploration of the effects of large phenotypic differences between cooperators and cheats. We predict that an intermediate ESS level of cooperation (molecule production) should exist. The adaptive dynamics approach allows us to assess evolutionary stability, which is often not possible in other kin-selection models. We found that selection can lead to an intermediate strategy which in our model is always evolutionarily stable, yet can allow invasion of strategies that are much more cooperative. Our model describes the evolution of a public good in the context of the ecology of the microorganism, which allows us to relate the extent of production of the public good to the details of the interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential exocytosis from human endothelial cells evoked by high intracellular Ca2+ concentration

PubMed Central

Zupančič, G; Ogden, D; Magnus, C J; Wheeler-Jones, C; Carter, T D

2002-01-01

Endothelial cells secrete a range of procoagulant, anticoagulant and inflammatory proteins by exocytosis to regulate blood clotting and local immune responses. The mechanisms regulating vesicular exocytosis were studied in human umbilical vein endothelial cells (HUVEC) with high-resolution membrane capacitance (Cm) measurements. The total whole-cell Cm and the amplitudes and times of discrete femtoFarad (fF)-sized Cm steps due to exocytosis and endocytosis were monitored simultaneously. Intracellular calcium concentration [Ca2+]i was elevated by intracellular photolysis of calcium-DM-nitrophen to evoke secretion and monitored with the low-affinity Ca2+ indicator furaptra. Sustained elevation of [Ca2+]i to > 20 μm evoked large, slow increases in Cm of up to 5 pF in 1-2 min. Exocytotic and endocytotic steps of amplitude 0.5-110 fF were resolved, and accounted on average for ≈33 % of the total Cm change. A prominent component of Cm steps of 2.5-9.0 fF was seen and could be attributed to exocytosis of von-Willebrand-factor-containing Weibel-Palade bodies (WPb), based on the near-identical distributions of capacitance step amplitudes, with calculated estimates of WPb capacitance from morphometry, and on the absence of 2.5-9.0 fF Cm steps in cells deficient in WPb. WPb secretion was delayed on average by 23 s after [Ca2+]i elevation, whereas total Cm increased immediately due to the secretion of small, non-WPb granules. The results show that following a large increase of [Ca2+]i, corresponding to strong stimulation, small vesicular components are immediately available for secretion, whereas the large WPb undergo exocytosis only after a delay. The presence of events of magnitude 9-110 fF also provides evidence of compound secretion of WPb due to prior fusion of individual granules. PMID:12411520

Studies on gastric bicarbonate secretion in man.

PubMed

Forssell, H

1987-01-01

A method for measurement of human basal and stimulated gastric bicarbonate secretion was developed in the present investigation. The mechanisms involved in the regulation of basal, vagus nerve stimulated as well as fundic distension induced bicarbonate secretion were studied. The investigations were performed in healthy subjects and duodenal ulcer patients, the latter group before and/or after a proximal gastric vagotomy operation. Healthy subjects as well as ulcer patients were premedicated with a histamine H2-receptor antagonist and gastric bicarbonate secretion was determined by use of a gastric perfusion system in combination with computerized continuous recordings of pH and PCO2. The contribution of alkaline saliva to the measured gastric bicarbonate secretion was minimized by continuous salivary suction and correction was made for swallowed saliva by measurement of amylase in the gastric aspirate. A high rate of gastric perfusion facilitated the identification of alkaline duodenogastric reflux and also eliminated its influence on the measurement of gastric bicarbonate secretion. Validation of the measuring system by instillation of small amounts of bicarbonate showed a satisfactory correlation between added and recovered bicarbonate in the range of bicarbonate determinations usually recorded. Decreasing intragastric pH to between 3 and 4 converted all secreted bicarbonate into CO2, but did not affect the measured value of bicarbonate secretion. Vagal stimulation accomplished by sham feeding increased gastric bicarbonate secretion in sixteen healthy subjects from 410 +/- 39 mumol/h to 692 +/- 67 mumol/h (mean +/- SEM, p less than 0.001). This response was independent of intragastric pH in the range of 2 to 7. The muscarinic receptor antagonist, benzilonium bromide, almost abolished the sham feeding response while indomethacin left it nearly unchanged. Nine duodenal ulcer patients had identical basal and vagally stimulated bicarbonate output as healthy subjects. Two months after proximal gastric vagotomy, the basal bicarbonate secretion was significantly increased, whereas the output in response to sham feeding was unaltered. In the early postoperative period, anticholinergics reduced the enhanced basal bicarbonate secretion to a preoperative level. In six healthy subjects, graded fundic distension with a balloon to volumes of 150 ml, 300 ml and 600 ml, each distension period lasting 60 minutes, increased the bicarbonate secretion by 46% (p less than 0.05), 28% (NS) and 84% (p less than 0.05), respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

The whipworm (Trichuris suis) secretes prostaglandin E2 to suppress proinflammatory properties in human dendritic cells.

PubMed

Laan, Lisa C; Williams, Andrew R; Stavenhagen, Kathrin; Giera, Martin; Kooij, Gijs; Vlasakov, Iliyan; Kalay, Hakan; Kringel, Helene; Nejsum, Peter; Thamsborg, Stig M; Wuhrer, Manfred; Dijkstra, Christine D; Cummings, Richard D; van Die, Irma

2017-02-01

Clinical trials have shown that administration of the nematode Trichuris suis can be beneficial in treating various immune disorders. To provide insight into the mechanisms by which this worm suppresses inflammatory responses, an active component was purified from T. suis soluble products (TsSPs) that suppress---- TNF and IL-12 secretion from LPS-activated human dendritic cells (DCs). Analysis by liquid chromatography tandem mass spectrometry identified this compound as prostaglandin (PG)E2. The purified compound showed similar properties compared with TsSPs and commercial PGE2 in modulating LPS-induced expression of many cytokines and chemokines and in modulating Rab7B and P2RX7 expression in human DCs. Furthermore, the TsSP-induced reduction of TNF secretion from DCs is reversed by receptor antagonists for EP2 and EP4, indicating PGE2 action. T. suis secretes extremely high amounts of PGE2 (45-90 ng/mg protein) within their excretory/secretory products but few related lipid mediators as established by metabololipidomic analysis. Culture of T. suis with several cyclooxygenase (COX) inhibitors that inhibit mammalian prostaglandin synthesis affected the worm's motility but did not inhibit PGE2 secretion, suggesting that the worms can synthesize PGE2 via a COX-independent pathway. We conclude that T. suis secretes PGE2 to suppress proinflammatory responses in human DCs, thereby modulating the host's immune response.-Laan, L. C., Williams, A. R., Stavenhagen, K., Giera, M., Kooij, G., Vlasakov, I., Kalay, H., Kringel, H., Nejsum, P., Thamsborg, S. M., Wuhrer, M., Dijkstra, C. D., Cummings, R. D., van Die, I. The whipworm (Trichuris suis) secretes prostaglandin E2 to suppress proinflammatory properties in human dendritic cells. © FASEB.

Role of sex steroids in progesterone and corticosterone response to acute restraint stress in rats: sex differences.

PubMed

Kalil, B; Leite, C M; Carvalho-Lima, M; Anselmo-Franci, J A

2013-07-01

Adrenal progesterone secretion increases along with corticosterone in response to stress in male and female rats to modulate some stress responses. Here we investigated the role of sex steroids in sex differences in the progesterone response to 60 min of restraint stress in adult male and female rats. Comparisons between males and females in the progesterone response were evaluated in parallel with corticosterone responses. From day 5 to 7 after gonadectomy, female and male rats were treated with estradiol or testosterone, respectively (OVX-E and ORCH-T groups), or oil (OVX and ORCH groups). Female rats in proestrus, intact and 7 d adrenalectomized (ADX) male rats were also studied. At 10:00 h, blood samples were withdrawn via an implanted jugular cannula before (-5 min), during (15, 30, 45, 60 min) and after (90 and 120 min) restraint stress to measure plasma progesterone and corticosterone concentrations by radioimmunoassay. Intact male and proestrus female rats exhibited similar progesterone responses to stress. Gonadectomy did not alter the amount of progesterone secreted during stress in female rats but decreased secretion in male rats. Unlike corticosterone, the progesterone response to stress in females was not influenced by estradiol. In males, testosterone replacement attenuated the progesterone and corticosterone responses to stress. Basal secretion of progesterone among intact, ORCH and ADX males was similar, but ADX-stressed rats secreted little progesterone. Hence, the gonads differently modulate adrenal progesterone and corticosterone responses to stress in female and male rats. The ovaries enhance corticosterone but not progesterone secretion, while the testes stimulate progesterone but not corticosterone secretion.

Mechanical properties of nanostructure of biological materials

NASA Astrophysics Data System (ADS)

Ji, Baohua; Gao, Huajian

2004-09-01

Natural biological materials such as bone, teeth and nacre are nanocomposites of protein and mineral with superior strength. It is quite a marvel that nature produces hard and tough materials out of protein as soft as human skin and mineral as brittle as classroom chalk. What are the secrets of nature? Can we learn from this to produce bio-inspired materials in the laboratory? These questions have motivated us to investigate the mechanics of protein-mineral nanocomposite structure. Large aspect ratios and a staggered alignment of mineral platelets are found to be the key factors contributing to the large stiffness of biomaterials. A tension-shear chain (TSC) model of biological nanostructure reveals that the strength of biomaterials hinges upon optimizing the tensile strength of the mineral crystals. As the size of the mineral crystals is reduced to nanoscale, they become insensitive to flaws with strength approaching the theoretical strength of atomic bonds. The optimized tensile strength of mineral crystals thus allows a large amount of fracture energy to be dissipated in protein via shear deformation and consequently enhances the fracture toughness of biocomposites. We derive viscoelastic properties of the protein-mineral nanostructure and show that the toughness of biocomposite can be further enhanced by the viscoelastic properties of protein.

Large Gliadin Peptides Detected in the Pancreas of NOD and Healthy Mice following Oral Administration

PubMed Central

Sidenius, Ulrik; Heegaard, Niels H.

2016-01-01

Gluten promotes type 1 diabetes in nonobese diabetic (NOD) mice and likely also in humans. In NOD mice and in non-diabetes-prone mice, it induces inflammation in the pancreatic lymph nodes, suggesting that gluten can initiate inflammation locally. Further, gliadin fragments stimulate insulin secretion from beta cells directly. We hypothesized that gluten fragments may cross the intestinal barrier to be distributed to organs other than the gut. If present in pancreas, gliadin could interact directly with the immune system and the beta cells to initiate diabetes development. We orally and intravenously administered 33-mer and 19-mer gliadin peptide to NOD, BALB/c, and C57BL/6 mice and found that the peptides readily crossed the intestinal barrier in all strains. Several degradation products were found in the pancreas by mass spectroscopy. Notably, the exocrine pancreas incorporated large amounts of radioactive label shortly after administration of the peptides. The study demonstrates that, even in normal animals, large gliadin fragments can reach the pancreas. If applicable to humans, the increased gut permeability in prediabetes and type 1 diabetes patients could expose beta cells directly to gliadin fragments. Here they could initiate inflammation and induce beta cell stress and thus contribute to the development of type 1 diabetes. PMID:27795959

[Effect of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) on gas exgange in patients after cardiac surgery].

PubMed

Benova, A; Dimitrov, N; Stoilova, M; Evstatiev, I; Tsarianski, G; Chirkov, A

2005-01-01

Fiberoptic bronchoscopy (FOB) has become a commonplace procedure in ICUs in patients after operation. We studied the outcomes of 35 FOBs performed in 26 patients (18 male and 8 female) during their stay in the ICU of "St. Ekaterina" University Hospital in Sofia after cardiac surgery with Cardiopulmonary Bypass. 33 (95%) of our patients were receiving mechanical ventilation at the time of the FOB. Bronchoalveolar lavage (BAL) was added to all procedures. 21 (60%) patients demonstrated an improvement after FOB. We defined improvement as either an increase of PaO2 with 10 or more mmHg in 6 hours after the procedure or better aeration on the follow-up chest radiograph (CXR). In 19 (54%) FOBs a great amount of secretions, plugging up bronchial lumens was seen. 14 (73%) of these patients were improved after the FOB. From the rest 16 patients, in whom such increased amount of secretions was not seen on FOB, only 7 (43%) demonstrated an improvement after the FOB. 16 procedures were performed on indications of atelectasis. 9 (56%) of them showed an improvement after the FOB. When atelectasis was not present on the CXR, an improvement was found in 12 (63%) cases. 1. FOB is most effective in removing retained secretions. 2. Although not so effective in resolving atelectasis that is not caused by central plugging, FOB should not be neglected because of the additional benefit of BAL for clearing more distal airways.

Choriodecidual Cells from Term Human Pregnancies Show Distinctive Functional Properties Related to the Induction of Labor

PubMed Central

Castillo-Castrejon, Marisol; Meraz-Cruz, Noemí; Gomez-Lopez, Nardhy; Flores-Pliego, Arturo; Beltrán-Montoya, Jorge; Viveros-Alcaráz, Martín; Vadillo-Ortega, Felipe

2014-01-01

Problem Human parturition is associated with an intrauterine pro-inflammatory environment in the choriodecidua. Evidence that some mediators of this signaling cascade also elicit responses leading to labor prompted us to characterize the cellular sources of these mediators in the human choriodecidua. Method of study Leukocyte-enriched preparations from human choriodecidua (ChL) and intervillous placental blood leukocytes (PL) were maintained in culture. Secretions of inflammatory cytokines, chemokines and MMP-9 were documented. Leukocyte phenotype of ChL and PL was determined by flow cytometry using specific fluorochrome-conjugated antibodies. Results and Conclusions ChL showed a distinct pro-inflammatory secretion pattern of cytokines and chemokines when compared with PL, including higher amounts of TNF-α and IL-6, and decreased secretions of IL-4 and IL-1ra. ChL also secreted more MIP-1α and MCP-1 and MMP-9 than PL. No significant differences were found in leukocytes subsets between compartments. Based on our findings, we propose that ChL isolated from fetal membranes at term are functionally different from PL and may collaborate to modulate the microenvironment linked to induction and progression of human labor. PMID:24286217

Mycoplasma detection and isolation from one-humped camels (Camelus dromedarius).

PubMed

Mederos-Iriarte, Lidia E; Poveda, José B; Poveda, Carlos G; Vega-Orellana, Orestes M; Gutiérrez, Carlos; Corbera, Juan A; Ramírez, Ana S

2014-10-01

In scientific literature, a small amount of information is found concerning mycoplasmosis in camel species. Mycoplasma (M.) arginini, Acholeplasma (A.) laidlawii, and Acholeplasma oculi have been reported to be isolated from these host species. Serologically positive results have been reported for Mycoplasma mycoides subsp. mycoides SC type, Mycoplasma capricolum subsp. capripneumoniae, and M. mycoides subsp. capri. The aims of this study were to detect, isolate, and identify mycoplasmas from camels (Camelus dromedarius). Initially, saliva and ear smears plus conjunctival and vaginal secretions were taken from five female animals, but only conjunctival secretions in three male animals, all belonging to the same farm. An unknown mycoplasma was isolated from one of the vagina samples. Additionally, another unknown and uncultured mycoplasma was detected with molecular biology in the same sample. In the second stage, 23 vaginal secretions were taken from the same farm plus another secretion from a different one. Ten isolates of the same unknown and previously isolated mycoplasma were detected, nine of them recovered from the vagina of female camels. Some mycoplasmas have been related to reproductive disorders; however, there is no evidence that the isolated mycoplasmas are related to such disorders.

Isolation of Endoplasmic Reticulum Fractions from Mammary Epithelial Tissue.

PubMed

Chanat, Eric; Le Parc, Annabelle; Lahouassa, Hichem; Badaoui, Bouabid

2016-06-01

In the mammary glands of lactating animals, the mammary epithelial cells that surround the lumen of the acini produce and secrete copious amounts of milk. Functional differentiation of these mammary epithelial cells depends on the development of high-efficiency secretory pathways, notably for protein and lipid secretion. Protein secretion is a fundamental process common to all animal cells that involves a subset of cellular organelles, including the endoplasmic reticulum and the Golgi apparatus. In contrast, en masse secretion of triglycerides and cholesterol esters in the form of milk fat globules is a unique feature of the mammary epithelial cell. Cytoplasmic lipid droplets, the intracellular precursors of milk fat globules, originate from the endoplasmic reticulum, as do most milk-specific proteins. This organelle is therefore pivotal in the biogenesis of milk components. Fractionation of the cell into its subcellular parts is an approach that has proven very powerful for understanding organelle function and for studying the specific role of an organelle in a given cell activity. Here we describe a method for the purification of both smooth and rough microsomes, the membrane-bound endoplasmic reticulum fragments that form from endoplasmic reticulum domains when cells are broken up, from mammary gland tissue at lactation.

Diabetes Mellitus and the Insulin Pump: What Teachers Need to Know

ERIC Educational Resources Information Center

Obringer, S. John; Coffey, Kenneth

2006-01-01

Diabetes is a condition where high amounts of glucose are found in the bloodstream due to impaired secretion of insulin. The hormone insulin was discovered by two physicians, Fredrick Banting and James Mcleod in 1921. Individuals with severe diabetes typically controlled their glucose level with multiple daily injections of insulin. Recently the…

Influence of ovarian reserves in beef heifers on uterine morphometry and function

USDA-ARS?s Scientific Manuscript database

The size of the reproductive tract and the number of follicles in the ovaries are positively associated with fertility and early conception in beef heifers. Heifers with greater numbers of ovarian follicles have larger uteri that secrete a greater amount of protein on day 16 after estrus. Therefor...

Gastric mucosal protective mechanisms: roles of epithelial bicarbonate and mucus secretions.

PubMed

Garner, A; Flemström, G; Allen, A; Heylings, J R; McQueen, S

1984-01-01

Secretion of HCO3 (amounting to 2-10% of maximum H+ secretion) in conjunction with the adherent mucus gel layer (functioning as a mixing barrier) protects gastric mucosa from luminal acid by a process of surface neutralization. Gastric HCO3 secretion is augmented by cholinergic agonists, prostaglandins and low luminal pH. Ulcerogens attenuate HCO3 secretion although passive diffusion of alkali consequent upon an increase in mucosal permeability may mask these inhibitory actions. Studies in vitro indicate that HCO3 transport in the stomach is dependent on oxidative metabolism, carbonic anhydrase activity and involves a CL exchange mechanism. Mucus, synthesized and released from epithelial cells, adheres to the mucosal surface as a thin (less than 80 microns in rat) but continuous gel layer. Prostaglandins and carbachol induced release of preformed mucus and thereby increase thickness, whereas acute exposure to ulcerogens has little effect on overall dimensions of the surface mucus layer. Measurements of pH gradients adjacent to gastric mucosa indicate that the disposal of luminal H+ occurs by extracellular neutralization. However, the fall in pH at the apical cell membrane when luminal pH is low (pH 1.5) suggests that while a mucus-bicarbonate barrier comprises the first line of mucosal defence, other factors are involved in the overall process of mucosal protection in the stomach.

Co-fermentation using Recombinant Saccharomyces cerevisiae Yeast Strains Hyper-secreting Different Cellulases for the Production of Cellulosic Bioethanol.

PubMed

Lee, Cho-Ryong; Sung, Bong Hyun; Lim, Kwang-Mook; Kim, Mi-Jin; Sohn, Min Jeong; Bae, Jung-Hoon; Sohn, Jung-Hoon

2017-06-30

To realize the economical production of ethanol and other bio-based chemicals from lignocellulosic biomass by consolidated bioprocessing (CBP), various cellulases from different sources were tested to improve the level of cellulase secretion in the yeast Saccharomyces cerevisiae by screening an optimal translational fusion partner (TFP) as both a secretion signal and fusion partner. Among them, four indispensable cellulases for cellulose hydrolysis, including Chaetomium thermophilum cellobiohydrolase (CtCBH1), Chrysosporium lucknowense cellobiohydrolase (ClCBH2), Trichoderma reesei endoglucanase (TrEGL2), and Saccharomycopsis fibuligera β-glucosidase (SfBGL1), were identified to be highly secreted in active form in yeast. Despite variability in the enzyme levels produced, each recombinant yeast could secrete approximately 0.6-2.0 g/L of cellulases into the fermentation broth. The synergistic effect of the mixed culture of the four strains expressing the essential cellulases with the insoluble substrate Avicel and several types of cellulosic biomass was demonstrated to be effective. Co-fermentation of these yeast strains produced approximately 14 g/L ethanol from the pre-treated rice straw containing 35 g/L glucan with 3-fold higher productivity than that of wild type yeast using a reduced amount of commercial cellulases. This process will contribute to the cost-effective production of bioenergy such as bioethanol and biochemicals from cellulosic biomass.

Transformation of postingestive glucose responses after deletion of sweet taste receptor subunits or gastric bypass surgery

PubMed Central

Geraedts, Maartje C. P.; Takahashi, Tatsuyuki; Vigues, Stephan; Markwardt, Michele L.; Nkobena, Andongfac; Cockerham, Renee E.; Hajnal, Andras; Dotson, Cedrick D.; Rizzo, Mark A.

2012-01-01

The glucose-dependent secretion of the insulinotropic hormone glucagon-like peptide-1 (GLP-1) is a critical step in the regulation of glucose homeostasis. Two molecular mechanisms have separately been suggested as the primary mediator of intestinal glucose-stimulated GLP-1 secretion (GSGS): one is a metabotropic mechanism requiring the sweet taste receptor type 2 (T1R2) + type 3 (T1R3) while the second is a metabolic mechanism requiring ATP-sensitive K+ (KATP) channels. By quantifying sugar-stimulated hormone secretion in receptor knockout mice and in rats receiving Roux-en-Y gastric bypass (RYGB), we found that both of these mechanisms contribute to GSGS; however, the mechanisms exhibit different selectivity, regulation, and localization. T1R3−/− mice showed impaired glucose and insulin homeostasis during an oral glucose challenge as well as slowed insulin granule exocytosis from isolated pancreatic islets. Glucose, fructose, and sucralose evoked GLP-1 secretion from T1R3+/+, but not T1R3−/−, ileum explants; this secretion was not mimicked by the KATP channel blocker glibenclamide. T1R2−/− mice showed normal glycemic control and partial small intestine GSGS, suggesting that T1R3 can mediate GSGS without T1R2. Robust GSGS that was KATP channel-dependent and glucose-specific emerged in the large intestine of T1R3−/− mice and RYGB rats in association with elevated fecal carbohydrate throughout the distal gut. Our results demonstrate that the small and large intestines utilize distinct mechanisms for GSGS and suggest novel large intestine targets that could mimic the improved glycemic control seen after RYGB. PMID:22669246

PITPNC1 recruits RAB1B to the Golgi network to drive malignant secretion

PubMed Central

Halberg, Nils; Sengelaub, Caitlin A.; Navrazhina, Kristina; Molina, Henrik; Uryu, Kunihiro; Tavazoie, Sohail F.

2017-01-01

SUMMARY Enhanced secretion of tumorigenic effector proteins is a feature of malignant cells. The molecular and cellular mechanisms underlying this feature are poorly defined. We identify PITPNC1 as a gene amplified in a large fraction of human breast cancer and over-expressed in metastatic breast, melanoma and colon cancer. Biochemical, molecular, and cell-biological studies reveal that PITPNC1 promotes malignant secretion by binding Golgi resident PI4P and localizing RAB1B to the Golgi. RAB1B localization to the Golgi allows for the recruitment of GOLPH3 to the trans-Golgi, which facilitates Golgi extension and enhanced vesicular release. PITPNC1-mediated vesicular release drives metastasis by increasing the secretion of pro-invasive and pro-angiogenic mediators HTRA1, MMP1, FAM3C, PDGFA, and ADAM10. We establish PITPNC1 as a PI4P-binding protein that enhances vesicular secretion capacity in malignancy. PMID:26977884

High-Yield Secretion of Multiple Client Proteins in Aspergillus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segato, F.; Damasio, A. R. L.; Goncalves, T. A.

2012-07-15

Production of pure and high-yield client proteins is an important technology that addresses the need for industrial applications of enzymes as well as scientific experiments in protein chemistry and crystallization. Fungi are utilized in industrial protein production because of their ability to secrete large quantities of proteins. In this study, we engineered a high-expression-secretion vector, pEXPYR that directs proteins towards the extracellular medium in two Aspergillii host strains, examine the effect of maltose-induced over-expression and protein secretion as well as time and pH-dependent protein stability in the medium. We describe five client proteins representing a core set of hemicellulose degradingmore » enzymes that accumulated up to 50-100 mg/L of protein. Using a recyclable genetic marker that allows serial insertion of multiple genes, simultaneous hyper-secretion of three client proteins in a single host strain was accomplished.« less

New insight in expression, transport, and secretion of brain-derived neurotrophic factor: Implications in brain-related diseases

PubMed Central

Adachi, Naoki; Numakawa, Tadahiro; Richards, Misty; Nakajima, Shingo; Kunugi, Hiroshi

2014-01-01

Brain-derived neurotrophic factor (BDNF) attracts increasing attention from both research and clinical fields because of its important functions in the central nervous system. An adequate amount of BDNF is critical to develop and maintain normal neuronal circuits in the brain. Given that loss of BDNF function has been reported in the brains of patients with neurodegenerative or psychiatric diseases, understanding basic properties of BDNF and associated intracellular processes is imperative. In this review, we revisit the gene structure, transcription, translation, transport and secretion mechanisms of BDNF. We also introduce implications of BDNF in several brain-related diseases including Alzheimer’s disease, Huntington’s disease, depression and schizophrenia. PMID:25426265

Limnonectins: a new class of antimicrobial peptides from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis).

PubMed

Wu, Youjia; Wang, Lei; Zhou, Mei; Ma, Chengbang; Chen, Xiaole; Bai, Bing; Chen, Tianbao; Shaw, Chris

2011-06-01

Amphibian skin secretions are rich sources of biologically-active peptides with antimicrobial peptides predominating in many species. Several studies involving molecular cloning of biosynthetic precursor-encoding cDNAs from skin or skin secretions have revealed that these exhibit highly-conserved domain architectures with an unusually high degree of conserved nucleotide and resultant amino acid sequences within the signal peptides. This high degree of nucleotide sequence conservation has permitted the design of primers complementary to such sites facilitating "shotgun" cloning of skin or skin secretion-derived cDNA libraries from hitherto unstudied species. Here we have used such an approach using a skin secretion-derived cDNA library from an unstudied species of Chinese frog - the Fujian large-headed frog, Limnonectes fujianensis - and have discovered two 16-mer peptides of novel primary structures, named limnonectin-1Fa (SFPFFPPGICKRLKRC) and limnonectin-1Fb (SFHVFPPWMCKSLKKC), that represent the prototypes of a new class of amphibian skin antimicrobial peptide. Unusually these limnonectins display activity only against a Gram-negative bacterium (MICs of 35 and 70 μM) and are devoid of haemolytic activity at concentrations up to 160 μM. Thus the "shotgun" cloning approach described can exploit the unusually high degree of nucleotide conservation in signal peptide-encoding domains of amphibian defensive skin secretion peptide precursor-encoding cDNAs to rapidly expedite the discovery of novel and functional defensive peptides in a manner that circumvents specimen sacrifice without compromising robustness of data. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Stress-induced dissociations between intracellular calcium signaling and insulin secretion in pancreatic islets.

PubMed

Qureshi, Farhan M; Dejene, Eden A; Corbin, Kathryn L; Nunemaker, Craig S

2015-05-01

In healthy pancreatic islets, glucose-stimulated changes in intracellular calcium ([Ca(2+)]i) provide a reasonable reflection of the patterns and relative amounts of insulin secretion. We report that [Ca(2+)]i in islets under stress, however, dissociates with insulin release in different ways for different stressors. Islets were exposed for 48h to a variety of stressors: cytokines (low-grade inflammation), 28mM glucose (28G, glucotoxicity), free fatty acids (FFAs, lipotoxicity), thapsigargin (ER stress), or rotenone (mitochondrial stress). We then measured [Ca(2+)]i and insulin release in parallel studies. Islets exposed to all stressors except rotenone displayed significantly elevated [Ca(2+)]i in low glucose, however, increased insulin secretion was only observed for 28G due to increased nifedipine-sensitive calcium-channel flux. Following 3-11mM glucose stimulation, all stressors substantially reduced the peak glucose-stimulated [Ca(2+)]i response (first phase). Thapsigargin and cytokines also substantially impacted aspects of calcium influx and ER calcium handling. Stressors did not significantly impact insulin secretion in 11mM glucose for any stressor, although FFAs showed a borderline reduction, which contributed to a significant decrease in the stimulation index (11:3mM glucose) observed for FFAs and also for 28G. We also clamped [Ca(2+)]i using 30mM KCl+250μM diazoxide to test the amplifying pathway. Only rotenone-treated islets showed a robust increase in 3-11mM glucose-stimulated insulin secretion under clamped conditions, suggesting that low-level mitochondrial stress might activate the metabolic amplifying pathway. We conclude that different stressors dissociate [Ca(2+)]i from insulin secretion differently: ER stressors (thapsigargin, cytokines) primarily affect [Ca(2+)]i but not conventional insulin secretion and 'metabolic' stressors (FFAs, 28G, rotenone) impacted insulin secretion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Condition-dependent pheromone signaling by male rock lizards: more oily scents are more attractive.

PubMed

Martín, José; López, Pilar

2010-05-01

Pheromones of vertebrates are often a mixture of several chemicals with different properties and messages, and their production seems condition dependent. Thus, pheromones are a good, but little studied, example of multiple sexual signals. Femoral gland secretions of male rock lizards Iberolacerta cyreni contain steroids that may act as pheromones, but there are also many other lipids, such as oleic acid, whose allocation to secretions may be costly because it has to be diverted from body fat reserves. This suggests that oleic acid could also have some function in secretions. Chemical analyses showed that proportions of oleic acid in femoral secretions of males were positively related to body condition of males, suggesting that the oleic acid secreted may reflect the amount of body fat reserves of a male. Tongue-flick bioassays showed that females were able to detect by chemosensory cues alone differences in proportions of oleic acid in secretions of males. Scents of males with more oleic acid elicited stronger chemosensory responses by females. Further tests with chemical standards confirmed that females distinguished oleic acid, and changes in its concentration, from other chemicals that are naturally found in secretions of males. Moreover, choice trials of scent-marked substrates showed that females were more attracted to areas that were experimentally manipulated to increase the proportion of oleic acid in natural scent marks of males. We suggest that oleic acid in femoral secretions might be a reliable advertisement of a male's body condition, which females could use to select high-quality mates in conjunction with information provided by other chemicals. Alternatively, scent marks with more oleic acid might be simply more attractive to females if chemosensory responses of females to scent of males were originated by a preexisting sensory bias for food chemicals such as the oleic acid. Nevertheless, this sensory trap might have evolved into an honest signal because the elaboration of the signal seems differentially costly for males with different body conditions.

Regulation of aldosterone secretion by mineralocorticoid receptor-mediated signaling.

PubMed

Chong, Cherish; Hamid, Anis; Yao, Tham; Garza, Amanda E; Pojoga, Luminita H; Adler, Gail K; Romero, Jose R; Williams, Gordon H

2017-03-01

We posit the existence of a paracrine/autocrine negative feedback loop, mediated by the mineralocorticoid receptor (MR), regulating aldosterone secretion. To assess this hypothesis, we asked whether altering MR activity in zona glomerulosa (ZG) cells affects aldosterone production. To this end, we studied ex vivo ZG cells isolated from male Wistar rats fed chow containing either high (1.6% Na + (HS)) or low (0.03% Na + (LS)) amount of sodium. Western blot analyses demonstrated that MR was present in both the ZG and zona fasciculata/zona reticularis (ZF/ZR/ZR). In ZG cells isolated from rats on LS chow, MR activation by fludrocortisone produced a 20% and 60% reduction in aldosterone secretion basally and in response to angiotensin II (ANGII) stimulation, respectively. Corticosterone secretion was increased in these cells suggesting that aldosterone synthase activity was being reduced by fludrocortisone. In contrast, canrenoic acid, an MR antagonist, enhanced aldosterone production by up to 30% both basally and in response to ANGII. Similar responses were observed in ZG cells from rats fed HS. Modulating glucocorticoid receptor (GR) activity did not alter aldosterone production by ZG cells; however, altering GR activity did modify corticosterone production from ZF/ZR/ZR cells both basally and in response to adrenocorticotropic hormone (ACTH). Additionally, activating the MR in ZF/ZR/ZR cells strikingly reduced corticosterone secretion. In summary, these data support the hypothesis that negative ultra-short feedback loops regulate adrenal steroidogenesis. In the ZG, aldosterone secretion is regulated by the MR, but not the GR, an effect that appears to be secondary to a change in aldosterone synthase activity. © 2017 Society for Endocrinology.

New saliva secretion model based on the expression of Na+-K+ pump and K+ channels in the apical membrane of parotid acinar cells.

PubMed

Almássy, János; Siguenza, Elias; Skaliczki, Marianna; Matesz, Klara; Sneyd, James; Yule, David I; Nánási, Péter P

2018-04-01

The plasma membrane of parotid acinar cells is functionally divided into apical and basolateral regions. According to the current model, fluid secretion is driven by transepithelial ion gradient, which facilitates water movement by osmosis into the acinar lumen from the interstitium. The osmotic gradient is created by the apical Cl - efflux and the subsequent paracellular Na + transport. In this model, the Na + -K + pump is located exclusively in the basolateral membrane and has essential role in salivary secretion, since the driving force for Cl - transport via basolateral Na + -K + -2Cl - cotransport is generated by the Na + -K + pump. In addition, the continuous electrochemical gradient for Cl - flow during acinar cell stimulation is maintained by the basolateral K + efflux. However, using a combination of single-cell electrophysiology and Ca 2+ -imaging, we demonstrate that photolysis of Ca 2+ close to the apical membrane of parotid acinar cells triggered significant K + current, indicating that a substantial amount of K + is secreted into the lumen during stimulation. Nevertheless, the K + content of the primary saliva is relatively low, suggesting that K + might be reabsorbed through the apical membrane. Therefore, we investigated the localization of Na + -K + pumps in acinar cells. We show that the pumps appear evenly distributed throughout the whole plasma membrane, including the apical pole of the cell. Based on these results, a new mathematical model of salivary fluid secretion is presented, where the pump reabsorbs K + from and secretes Na + to the lumen, which can partially supplement the paracellular Na + pathway.

The Rab11 Effector Protein FIP1 Regulates Adiponectin Trafficking and Secretion

PubMed Central

Moreno-Navarrete, Jose Maria; Fernandez-Real, Jose Manuel; Mora, Silvia

2013-01-01

Adiponectin is an adipokine secreted by white adipocytes involved in regulating insulin sensitivity in peripheral tissues. Secretion of adiponectin in adipocytes relies on the endosomal system, however, the intracellular machinery involved in mediating adiponectin release is unknown. We have previously reported that intracellular adiponectin partially compartmentalizes with rab 5 and rab11, markers for the early/sorting and recycling compartments respectively. Here we have examined the role of several rab11 downstream effector proteins (rab11 FIPs) in regulating adiponectin trafficking and secretion. Overexpression of wild type rab11 FIP1, FIP3 and FIP5 decreased the amount of secreted adiponectin expressed in HEK293 cells, whereas overexpression of rab11 FIP2 or FIP4 had no effect. Furthermore shRNA-mediated depletion of FIP1 enhanced adiponectin release whereas knock down of FIP5 decreased adiponectin secretion. Knock down of FIP3 had no effect. In 3T3L1 adipocytes, endogenous FIP1 co-distributed intracellularly with endogenous adiponectin and FIP1 depletion enhanced adiponectin release without altering insulin-mediated trafficking of the glucose transporter Glut4. While adiponectin receptors internalized with transferrin receptors, there were no differences in transferrin receptor recycling between wild type and FIP1 depleted adipocytes. Consistent with its inhibitory role, FIP1 expression was decreased during adipocyte differentiation, by treatment with thiazolidinediones, and with increased BMI in humans. In contrast, FIP1 expression increased upon exposure of adipocytes to TNFα. In all, our findings identify FIP1 as a novel protein involved in the regulation of adiponectin trafficking and release. PMID:24040321

Enrichment and Detection of Molecules Secreted by Tumor Cells Using Magnetic Reversed-Phase Particles and LC-MALDI-TOF-MS

PubMed Central

Peter, Jochen F.; Otto, Angela M.; Wolf, Bernhard

2007-01-01

Tumor cells change their genetic expression pattern as they progress to states of increasing malignancy. Investigations at the DNA and RNA level alone cannot provide all the information resulting after the translation and processing of the corresponding proteins, which is one reason for a poor correlation between mRNA and the respective protein abundance. In diagnostics, differentially expressed peptides or proteins are important markers for the early detection of cancer. Unfortunately, tumor cells secrete peptides and proteins in only very low amounts, making mass spectrometric determination very difficult. In this publication, methods have been developed for the effective enrichment and cleanup of substances secreted by cultivated cancer cells. To obviate peptides from fetal calf serum used in cell culture, a serum surrogate was developed, which maintained growth of the cancer cells. After the binding of substances from cell-culture supernatants to custom-made magnetic reversed-phase particles, the substances were eluted and separated by capillary high-performance liquid chromatography. Fractions were spotted directly on a MALDI target, and MALDI-TOF mass spectrometric data acquisition was performed in automatic mode. This technology was used to detect substances secreted by two mammary carcinoma cell lines differing in their malignancy (MCF-7, MDA-MB231). Unequivocal differences in the peptide secretion patterns were observed. In conclusion, this system allows the sensitive investigation of peptides secreted by cancer cells in culture and provides a valuable tool for the investigation of cancer cells in different states of malignancy. PMID:18166672

Transfection of primary brain capillary endothelial cells for protein synthesis and secretion of recombinant erythropoietin: a strategy to enable protein delivery to the brain.

PubMed

Burkhart, Annette; Andresen, Thomas Lars; Aigner, Achim; Thomsen, Louiza Bohn; Moos, Torben

2017-07-01

Treatment of chronic disorders affecting the central nervous system (CNS) is complicated by the inability of drugs to cross the blood-brain barrier (BBB). Non-viral gene therapy applied to brain capillary endothelial cells (BCECs) denotes a novel approach to overcome the restraints in this passage, as turning BCECs into recombinant protein factories by transfection could result in protein secretion further into the brain. The present study aims to investigate the possibility of transfecting primary rat brain endothelial cells (RBECs) for recombinant protein synthesis and secretion of the neuroprotective protein erythropoietin (EPO). We previously showed that 4% of RBECs with BBB properties can be transfected without disrupting the BBB integrity in vitro, but it can be questioned whether this is sufficient to enable protein secretion at therapeutic levels. The present study examined various transfection vectors, with regard to increasing the transfection efficiency without disrupting the BBB integrity. Lipofectamine 3000™ was the most potent vector compared to polyethylenimine (PEI) and Turbofect. When co-cultured with astrocytes, the genetically modified RBECs secreted recombinant EPO into the cell culture medium both luminally and abluminally, and despite lower levels of EPO reaching the abluminal chamber, the amount of recombinant EPO was sufficient to evolve a biological effect on astrocytes cultured at the abluminal side in terms of upregulated gene expression of brain-derived neurotropic factor (BDNF). In conclusion, non-viral gene therapy to RBECs leads to protein secretion and signifies a method for therapeutic proteins to target cells inside the CNS otherwise omitted due to the BBB.

Cell Surface Galectin-9 Expressing Th Cells Regulate Th17 and Foxp3+ Treg Development by Galectin-9 Secretion

PubMed Central

Niki, Toshiro; Kadowaki, Takeshi; Ueno, Masaki; Nishi, Nozomu; Yamauchi, Akira; Hattori, Toshio; Masaki, Tsutomu; Hirashima, Mitsuomi

2012-01-01

Galectin-9 (Gal-9), a β-galactoside binding mammalian lectin, regulates immune responses by reducing pro-inflammatory IL-17-producing Th cells (Th17) and increasing anti-inflammatory Foxp3+ regulatory T cells (Treg) in vitro and in vivo. These functions of Gal-9 are thought to be exerted by binding to receptor molecules on the cell surface. However, Gal-9 lacks a signal peptide for secretion and is predominantly located in the cytoplasm, which raises questions regarding how and which cells secrete Gal-9 in vivo. Since Gal-9 expression does not necessarily correlate with its secretion, Gal-9-secreting cells in vivo have been elusive. We report here that CD4 T cells expressing Gal-9 on the cell surface (Gal-9+ Th cells) secrete Gal-9 upon T cell receptor (TCR) stimulation, but other CD4 T cells do not, although they express an equivalent amount of intracellular Gal-9. Gal-9+ Th cells expressed interleukin (IL)-10 and transforming growth factor (TGF)-β but did not express Foxp3. In a co-culture experiment, Gal-9+ Th cells regulated Th17/Treg development in a manner similar to that by exogenous Gal-9, during which the regulation by Gal-9+ Th cells was shown to be sensitive to a Gal-9 antagonist but insensitive to IL-10 and TGF-β blockades. Further elucidation of Gal-9+ Th cells in humans indicates a conserved role of these cells through evolution and implies the possible utility of these cells for diagnosis or treatment of immunological diseases. PMID:23144904

DBSecSys: a database of Burkholderia mallei secretion systems.

PubMed

Memišević, Vesna; Kumar, Kamal; Cheng, Li; Zavaljevski, Nela; DeShazer, David; Wallqvist, Anders; Reifman, Jaques

2014-07-16

Bacterial pathogenicity represents a major public health concern worldwide. Secretion systems are a key component of bacterial pathogenicity, as they provide the means for bacterial proteins to penetrate host-cell membranes and insert themselves directly into the host cells' cytosol. Burkholderia mallei is a Gram-negative bacterium that uses multiple secretion systems during its host infection life cycle. To date, the identities of secretion system proteins for B. mallei are not well known, and their pathogenic mechanisms of action and host factors are largely uncharacterized. We present the Database of Burkholderia malleiSecretion Systems (DBSecSys), a compilation of manually curated and computationally predicted bacterial secretion system proteins and their host factors. Currently, DBSecSys contains comprehensive experimentally and computationally derived information about B. mallei strain ATCC 23344. The database includes 143 B. mallei proteins associated with five secretion systems, their 1,635 human and murine interacting targets, and the corresponding 2,400 host-B. mallei interactions. The database also includes information about 10 pathogenic mechanisms of action for B. mallei secretion system proteins inferred from the available literature. Additionally, DBSecSys provides details about 42 virulence attenuation experiments for 27 B. mallei secretion system proteins. Users interact with DBSecSys through a Web interface that allows for data browsing, querying, visualizing, and downloading. DBSecSys provides a comprehensive, systematically organized resource of experimental and computational data associated with B. mallei secretion systems. It provides the unique ability to study secretion systems not only through characterization of their corresponding pathogen proteins, but also through characterization of their host-interacting partners.The database is available at https://applications.bhsai.org/dbsecsys.

Regulation of extrafloral nectar secretion by jasmonates in lima bean is light dependent

PubMed Central

Radhika, Venkatesan; Kost, Christian; Mithöfer, Axel; Boland, Wilhelm

2010-01-01

To maximize fitness, plants need to perceive changes in their light environment and adjust their physiological responses accordingly. Whether and how such changes also affect the regulation of their defense responses against herbivores remains largely unclear. We addressed this issue by studying the secretion of extrafloral nectar (EFN) in lima bean (Phaseolus lunatus), which is known to be activated by the phytohormone jasmonic acid (JA) and functions as an indirect defense mechanism against herbivores. We found that the plant’s EFN secretion in response to JA was light dependent: In the dark, JA reduced EFN secretion, whereas under light conditions, JA induced EFN secretion relative to controls. This modulation was affected by the light’s spectral composition [i.e., ratio of red to far-red (R:FR) radiation], but not light intensity. These findings demonstrate a unique differential effect of JA on EFN secretion depending on the ambient light conditions. Interestingly, treatment with the isoleucine–JA conjugate (JA–Ile) enhanced EFN secretion under light conditions yet did not reduce EFN secretion in the dark. Moreover, inhibition of Ile biosynthesis in light-exposed plants significantly decreased the EFN secretion rate. This reduction could be recovered by additional application of JA–Ile, suggesting that JA–Ile is the active compound required to up-regulate EFN secretion. Finally, experiments with mechanically damaged plants revealed that light was required for the formation of JA–Ile, but not of JA. These results demonstrate that in lima bean, the light environment modulates the plant’s response to jasmonates as well as JA–Ile biosynthesis, which controls the subsequent EFN secretion. PMID:20855624

Molecular cloning and expression in mammalian cells of ricin B chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, M.

1987-01-01

In these studies, the cDNA encoding the B chain of ricin has been cloned and expressed in monkey kidney COS-M6 cells. The recombinant B chain was detected by labeling the transfected cells with {sup 35}S-methionine and {sup 35}S-cysteine and demonstrating secretion of a protein with a Mr of 30-32,000 which was not present in the medium of mock-transfected COS-M6 cells. This protein was specifically immunoprecipitated by an anti-ricin or anti-B chain antibody. The amount of recombinant B chain secreted by the COS-M6 cells was determined by radioimmunoassay to be 1-10 ng/ml of media. Virtually all the recombinant B chain formedmore » active ricin when mixed with native A chain; it could also bind as effectively as native B chain to the galactose-containing glycoprotein, asialofetuin. These results indicate that the vast majority of recombinant B chains secreted into the medium of the COS-M6 cells retain biological function.« less

Cloning and expression of recombinant, functional ricin B chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, M.S.; Russell, D.W.; Uhr, J.W.

1987-08-01

The cDNA encoding the B chain of the plant toxin ricin has been cloned and expressed in monkey kidney COS-M6 cells. The recombinant B chain was detected by labeling the transfected cells with (/sup 35/S)methionine and (/sup 35/S)-cysteine and demonstrating the secretion of a protein with a M/sub r/ of 30,000-32,000 that was not present in the medium of mock-transfected COS-M6 cells. This protein was specifically immunoprecipitated by an anti-ricin or anti-B-chain antibody and the amount of recombinant B chain secreted by the COS-M6 cells was determined by a radioimmunoassay. Virtually all of the recombinant B chain formed active ricinmore » when mixed with native A chain; it could also bind to the galactose-containing glycoprotein asialofetuin as effectively as native B chain.These results indicate that the vast majority of recombinant B chains secreted into the medium of the COS-M6 cells retain biological function« less

Heterogeneous Households A within-subject test of asymmetric information between spouses in Kenya

PubMed Central

Hoel, Jessica B.

2015-01-01

To identify which spouses respond to asymmetric information, I play two dictator games with each member of the couple. One decision is kept secret from the respondent's spouse, while another choice is public. Most people give the same amount in public and secret, while a minority behave opportunistically and give more to their spouse in public and less in secret. The types identified in the lab also behave differently at home. For those who behave opportunistically in the lab, greater knowledge about finances at home is associated with worse opportunism in the lab, suggesting that for these couples complete information at home is not due to trust but rather is an endogenous response to non-cooperative behavior. The paper highlights that allowing for heterogeneous types changes the conclusions we draw about appropriate models of the household and suggests that laboratory games can be used to identify household types useful in the interpretation of field data. PMID:26504256

Periostin is identified as a putative metastatic marker in breast cancer-derived exosomes

PubMed Central

Vardaki, Ioulia; Ceder, Sophia; Rutishauser, Dorothea; Baltatzis, George; Foukakis, Theodoros; Panaretakis, Theocharis

2016-01-01

Breast cancer (BrCa) is the most frequent cancer type in women and a leading cause of cancer related deaths in the world. Despite the decrease in mortality due to better diagnostics and palliative care, there is a lack of prognostic markers of metastasis. Recently, the exploitation of liquid biopsies and in particular of the extracellular vesicles has shown promise in the identification of such prognostic markers. In this study we compared the proteomic content of exosomes derived from metastatic and non-metastatic human (MCF7 and MDA-MB-231) and mouse (67NR and 4T1) cell lines. We found significant differences not only in the amount of secreted exosomes but most importantly in the protein content of exosomes secreted from metastatic versus non-metastatic ones. We identified periostin as a protein that is enriched in exosomes secreted by metastatic cells and validated its presence in a pilot cohort of breast cancer patient samples with localized disease or lymph node (LN) metastasis. PMID:27589561

Periostin is identified as a putative metastatic marker in breast cancer-derived exosomes.

PubMed

Vardaki, Ioulia; Ceder, Sophia; Rutishauser, Dorothea; Baltatzis, George; Foukakis, Theodoros; Panaretakis, Theocharis

2016-11-15

Breast cancer (BrCa) is the most frequent cancer type in women and a leading cause of cancer related deaths in the world. Despite the decrease in mortality due to better diagnostics and palliative care, there is a lack of prognostic markers of metastasis. Recently, the exploitation of liquid biopsies and in particular of the extracellular vesicles has shown promise in the identification of such prognostic markers. In this study we compared the proteomic content of exosomes derived from metastatic and non-metastatic human (MCF7 and MDA-MB-231) and mouse (67NR and 4T1) cell lines. We found significant differences not only in the amount of secreted exosomes but most importantly in the protein content of exosomes secreted from metastatic versus non-metastatic ones. We identified periostin as a protein that is enriched in exosomes secreted by metastatic cells and validated its presence in a pilot cohort of breast cancer patient samples with localized disease or lymph node (LN) metastasis.

The Amino Acid Valine Is Secreted in Continuous-Flow Bacterial Biofilms▿ ‡

PubMed Central

Valle, Jaione; Da Re, Sandra; Schmid, Solveig; Skurnik, David; D'Ari, Richard; Ghigo, Jean-Marc

2008-01-01

Biofilms are structured communities characterized by distinctive gene expression patterns and profound physiological changes compared to those of planktonic cultures. Here, we show that many gram-negative bacterial biofilms secrete high levels of a small-molecular-weight compound, which inhibits the growth of only Escherichia coli K-12 and a rare few other natural isolates. We demonstrate both genetically and biochemically that this molecule is the amino acid valine, and we provide evidence that valine production within biofilms results from metabolic changes occurring within high-density biofilm communities when carbon sources are not limiting. This finding identifies a natural environment in which bacteria can encounter high amounts of valine, and we propose that in-biofilm valine secretion may be the long-sought reason for widespread but unexplained valine resistance found in most enterobacteria. Our results experimentally validate the postulated production of metabolites that is characteristic of the conditions associated with some biofilm environments. The identification of such molecules may lead to new approaches for biofilm monitoring and control. PMID:17981982

PREFERENTIAL SECRETION OF INDUCIBLE HSP70 BY VITILIGO MELANOCYTES UNDER STRESS

PubMed Central

Mosenson, Jeffrey A.; Flood, Kelsey; Klarquist, Jared; Eby, Jonathan M.; Koshoffer, Amy; Boissy, Raymond E.; Overbeck, Andreas; C.Tung, Rebecca; Poole, I. Caroline Le

2014-01-01

SUMMARY Inducible HSP70 (HSP70i) chaperones peptides from stressed cells, protecting them from apoptosis. Upon extracellular release, HSP70i serves an adjuvant function, enhancing immune responses to bound peptides. We questioned whether HSP70i differentially protects control and vitiligo melanocytes from stress and subsequent immune responses. We compared expression of HSP70i in skin samples, evaluated the viability of primary vitiligo and control melanocytes exposed to bleaching phenols, and measured secreted HSP70i. We determined whether HSP70i traffics to melanosomes to contact immunogenic proteins by cell fractionation, western blotting, electron microscopy and confocal microscopy. Viability of vitiligo and control melanocytes was equally affected under stress. However, vitiligo melanocytes secreted increased amounts of HSP70i in response to MBEH, corroborating with aberrant HSP70i expression in patient skin. Intracellular HSP70i colocalized with melanosomes, and more so in response to MBEH in vitiligo melanocytes. Thus whereas either agent is cytotoxic to melanocytes, MBEH preferentially induces immune responses to melanocytes. PMID:24354861

The dipeptide Pro-Asp promotes IGF-1 secretion and expression in hepatocytes by enhancing JAK2/STAT5 signaling pathway.

PubMed

Wang, Songbo; Wang, Guoqing; Zhang, Mengyuan; Zhuang, Lu; Wan, Xiaojuan; Xu, Jingren; Wang, Lina; Zhu, Xiaotong; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Shu, Gang; Jiang, Qingyan

2016-11-15

It has been implicated that IGF-1 secretion can be regulated by dietary protein. However, whether the dipeptides, one of digested products of dietary protein, have influence on IGF-1 secretion remain largely unknown. Our study aimed to investigate the effects of the dipeptide Pro-Asp on IGF-1 secretion and expression in hepatocytes and to explore the possible underlying mechanisms. Our findings demonstrated that Pro-Asp promoted the secretion and gene expression of IGF-1 in HepG2 cells and primary porcine hepatocytes. Meanwhile, Pro-Asp activated the ERK and Akt signaling pathways, downstream of IGF-1. In addition, Pro-Asp enhanced GH-mediated JAK2/STAT5 signaling pathway, while inhibition of JAK2/STAT5 blocked the promotive effect of Pro-Asp on IGF-1 secretion and expression. Moreover, acute injection of Pro-Asp stimulated IGF-1 expression and activated JAK2/STAT5 signaling pathway in mice liver. Together, these results suggested that the dipeptide Pro-Asp promoted IGF-1 secretion and expression in hepatocytes by enhancing GH-mediated JAK2/STAT5 signaling pathway. Copyright © 2016. Published by Elsevier Ireland Ltd.

Over-expression of ZnT7 increases insulin synthesis and secretion in pancreatic beta-cells by promoting insulin gene transcription

USDA-ARS?s Scientific Manuscript database

The mechanism by which zinc regulates insulin synthesis and secretion in pancreatic beta-cells is still unclear. Cellular zinc homeostasis is largely maintained by zinc transporters and intracellular zinc binding proteins. In this study, we demonstrated that zinc transporter 7 (ZnT7, Slc30a7) was co...

The Gasdermin-D pore acts as a conduit for IL-1β secretion in mice.

PubMed

Heilig, Rosalie; Dick, Mathias S; Sborgi, Lorenzo; Meunier, Etienne; Hiller, Sebastian; Broz, Petr

2018-04-01

The pro-inflammatory cytokine IL-1β is well known for its role in host defense and the initiation of potent inflammatory responses. It is processed from its inactive pro-form by the inflammatory caspase-1 into its mature bioactive form, which is then released from the cell via an unconventional secretion mechanism. Recently, gasdermin-D has been identified as a new target of caspase-1. After proteolytical cleavage of gasdermin-D, the N-terminal fragment induces pyroptosis, a lytic cell death, by forming large permeability pores in the plasma membrane. Here we show using the murine system that gasdermin-D is required for IL-1β secretion by macrophages, dendritic cells and partially in neutrophils, and that secretion is a cell-lysis-independent event. Liposome transport assays in vitro further demonstrate that gasdermin-D pores are large enough to allow the direct release of IL-1β. Moreover, IL-18 and other small soluble cytosolic proteins can also be released in a lysis-independent but gasdermin-D-dependent mode, suggesting that the gasdermin-D pores allow passive the release of cytosolic proteins in a size-dependent manner. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proteomic Analysis of the Secretory Response of Aspergillus niger to D-Maltose and D-Xylose

PubMed Central

Ferreira de Oliveira, José Miguel P.; van Passel, Mark W. J.; Schaap, Peter J.; de Graaff, Leo H.

2011-01-01

Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition. During growth of A. niger on d-sorbitol, small amounts of d-maltose or d-xylose were used as inducers of the extracellular amylolytic and xylanolytic enzymes. Upon induction, protein compositions in the extracellular broth as well as in enriched secretory organelle (microsomal) fractions were analyzed using a shotgun proteomics approach. In total 102 secreted proteins and 1,126 microsomal proteins were identified in this study. Induction by d-maltose or d-xylose resulted in the increase in specific extracellular enzymes, such as glucoamylase A on d-maltose and β-xylosidase D on d-xylose, as well as of microsomal proteins. This reflects the differential expression of selected genes coding for dedicated extracellular enzymes. As expected, the addition of extra d-sorbitol had no effect on the expression of carbohydrate-active enzymes, compared to addition of d-xylose or d-maltose. Furthermore, d-maltose induction caused an increase in microsomal proteins related to translation (e.g., Rpl15) and vesicular transport (e.g., the endosomal-cargo receptor Erv14). Millimolar amounts of the inducers d-maltose and d-xylose are sufficient to cause a direct response in specific protein expression levels. Also, after induction by d-maltose or d-xylose, the induced enzymes were found in microsomes and extracellular. In agreement with our previous findings for d-xylose induction, d-maltose induction leads to recruitment of proteins involved in proteasome-mediated degradation. PMID:21698107

Proteomic analysis of the secretory response of Aspergillus niger to D-maltose and D-xylose.

PubMed

de Oliveira, José Miguel P Ferreira; van Passel, Mark W J; Schaap, Peter J; de Graaff, Leo H

2011-01-01

Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition. During growth of A. niger on D-sorbitol, small amounts of D-maltose or D-xylose were used as inducers of the extracellular amylolytic and xylanolytic enzymes. Upon induction, protein compositions in the extracellular broth as well as in enriched secretory organelle (microsomal) fractions were analyzed using a shotgun proteomics approach. In total 102 secreted proteins and 1,126 microsomal proteins were identified in this study. Induction by D-maltose or D-xylose resulted in the increase in specific extracellular enzymes, such as glucoamylase A on D-maltose and β-xylosidase D on D-xylose, as well as of microsomal proteins. This reflects the differential expression of selected genes coding for dedicated extracellular enzymes. As expected, the addition of extra D-sorbitol had no effect on the expression of carbohydrate-active enzymes, compared to addition of D-xylose or D-maltose. Furthermore, D-maltose induction caused an increase in microsomal proteins related to translation (e.g., Rpl15) and vesicular transport (e.g., the endosomal-cargo receptor Erv14). Millimolar amounts of the inducers D-maltose and D-xylose are sufficient to cause a direct response in specific protein expression levels. Also, after induction by D-maltose or D-xylose, the induced enzymes were found in microsomes and extracellular. In agreement with our previous findings for D-xylose induction, D-maltose induction leads to recruitment of proteins involved in proteasome-mediated degradation.

The secretion of alkali metal ions by the perfused cat pancreas as influenced by the composition and osmolality of the external environment and by inhibitors of metabolism and Na+, K+-ATPase activity

PubMed Central

Case, R. M.; Scratcherd, T.

1974-01-01

1. The secretion of sodium, potassium and lithium has been studied in the isolated cat pancreas, perfused with bicarbonate buffered saline solutions of varying composition and osmolality, and stimulated maximally with secretin. 2. Under isosmolal conditions, when perfusate sodium chloride was replaced by sucrose, sodium secretion and potassium secretion were directly related to perfusate sodium concentration, [Na]p. 3. When osmolality was varied by increasing or decreasing perfusate sodium chloride concentration, the secretion of sodium and of potassium were maximal at [Na]p of about 120 and 80 mM respectively. 4. At a given [Na]p, sodium secretion was greater under hypo-osmolal conditions than under isosmolal conditions. 5. When potassium concentration was varied over the range 0-130 mM under isosmolal conditions, by adjusting perfusate NaCl concentration, the secretion of potassium and of sodium were maximal at [K]p of about 50 and 10 mM respectively. Water flux was maximal at a [K]p of 10-15 mM. The concentration of potassium in the secretion was almost identical with that in the perfusate over the whole concentration range. 6. Replacement of perfusate sodium by lithium reduced the volume of secretion, though a small secretion was maintained even in the complete absence of sodium. The concentration of lithium in the secretion was generally slightly greater than that in the perfusate. 7. Omission of potassium from the perfusate reduced secretion by about 65%. Rubidium was a complete substitute for potassium; caesium was not. 8. Energy for secretion is derived largely from oxidative phosphorylation. Secretion was reduced by more than 90% under anaerobic conditions and in the presence of dinitrophenol or cyanide. Removal of glucose from the perfusate reduced secretion by more than 50% within 30 min; lactate was a complete substitute for glucose. 9. Ouabain, ethacrinic acid and frusimide, known inhibitors of Na+, K+-ATPase activity, all inhibited pancreatic electrolyte secretion. 10. The observations are interpreted with reference to the nature of active transport processes involved in pancreatic electrolyte secretion. PMID:4281836

Impact of dietary lipids on sow milk composition and balance of essential fatty acids during lactation in prolific sows.

PubMed

Rosero, D S; Odle, J; Mendoza, S M; Boyd, R D; Fellner, V; van Heugten, E

2015-06-01

Two studies were designed to determine the effects of supplementing diets with lipid sources of EFA (linoleic and α-linolenic acid) on sow milk composition to estimate the balance of EFA for sows nursing large litters. In Exp. 1, 30 sows, equally balanced by parity (1 and 3 to 5) and nursing 12 pigs, were fed diets supplemented with 6% animal-vegetable blend (A-V), 6% choice white grease (CWG), or a control diet without added lipid. Diets were corn-soybean meal based with 8% corn distiller dried grains with solubles and 6% wheat middlings and contained 3.25 g standardized ileal digestible Lys/Mcal ME. Sows fed lipid-supplemented diets secreted greater amounts of fat (P = 0.082; 499 and 559 g/d for control and lipid-added diets, respectively) than sows fed the control diet. The balance of EFA was computed as apparent ileal digestible intake of EFA minus the outflow of EFA in milk. For sows fed the control diet, the amount of linoleic acid secreted in milk was greater than the amount consumed, throughout lactation. This resulted in a pronounced negative balance of linoleic acid (-22.4, -38.0, and -14.1 g/d for d 3, 10, and 17 of lactation, respectively). In Exp. 2, 50 sows, equally balanced by parity and nursing 12 pigs, were randomly assigned to a 2 × 2 factorial arrangement of diets plus a control diet without added lipids. Factors included linoleic acid (2.1% and 3.3%) and α-linolenic acid (0.15% and 0.45%). The different concentrations of EFA were obtained by adding 4% of different mixtures of canola, corn, and flaxseed oils to diets. The n-6 to n-3 fatty acid ratios in the diets ranged from 5 to 22. Increasing supplemental EFA increased (P < 0.001) milk concentrations of linoleic (16.7% and 20.8%, for 2.1% and 3.3% linoleic acid, respectively) and α-linolenic acid (P < 0.001; 1.1 and 1.9% for 0.15 and 0.45% α-linolenic acid, respectively). Increasing supplemental EFA increased the estimated balance of α-linolenic acid (P < 0.001; -0.2 and 5.3 g/d for 0.15% and 0.45% α-linolenic acid, respectively), but not linoleic acid (P = 0.14; -3.4 and 10.0 g/d for 2.1% and 3.3% linoleic acid, respectively). In conclusion, lipid supplementation to sow lactation diets improved milk fat secretion. The fatty acid composition of milk fat reflected the dietary supplementation of EFA. The net effect of supplemental EFA was to create a positive balance during lactation, which may prove to be beneficial for the development of nursing piglets and the subsequent reproduction of sows.

Quantifying time-varying cellular secretions with local linear models.

PubMed

Byers, Jeff M; Christodoulides, Joseph A; Delehanty, James B; Raghu, Deepa; Raphael, Marc P

2017-07-01

Extracellular protein concentrations and gradients initiate a wide range of cellular responses, such as cell motility, growth, proliferation and death. Understanding inter-cellular communication requires spatio-temporal knowledge of these secreted factors and their causal relationship with cell phenotype. Techniques which can detect cellular secretions in real time are becoming more common but generalizable data analysis methodologies which can quantify concentration from these measurements are still lacking. Here we introduce a probabilistic approach in which local-linear models and the law of mass action are applied to obtain time-varying secreted concentrations from affinity-based biosensor data. We first highlight the general features of this approach using simulated data which contains both static and time-varying concentration profiles. Next we apply the technique to determine concentration of secreted antibodies from 9E10 hybridoma cells as detected using nanoplasmonic biosensors. A broad range of time-dependent concentrations was observed: from steady-state secretions of 230 pM near the cell surface to large transients which reached as high as 56 nM over several minutes and then dissipated.

Chemosystematics in the Opiliones (Arachnida): a comment on the evolutionary history of alkylphenols and benzoquinones in the scent gland secretions of Laniatores

PubMed Central

Raspotnig, Günther; Bodner, Michaela; Schäffer, Sylvia; Koblmüller, Stephan; Schönhofer, Axel; Karaman, Ivo

2015-01-01

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best-studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best-fitting explanation of the distribution of scent-gland secretion compounds across extant laniatorean taxa, and hence represent a key toward a well-founded opilionid chemosystematics. PMID:26074662

Chemosystematics in the Opiliones (Arachnida): a comment on the evolutionary history of alkylphenols and benzoquinones in the scent gland secretions of Laniatores.

PubMed

Raspotnig, Günther; Bodner, Michaela; Schäffer, Sylvia; Koblmüller, Stephan; Schönhofer, Axel; Karaman, Ivo

2015-04-01

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best-studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best-fitting explanation of the distribution of scent-gland secretion compounds across extant laniatorean taxa, and hence represent a key toward a well-founded opilionid chemosystematics.

Adsorption of surfactant protein D from human respiratory secretions by carbon nanotubes and polystyrene nanoparticles depends on nanomaterial surface modification and size

PubMed Central

Marchetti, Magda; Shaffer, Milo S. P.; Zambianchi, Martina; Chen, Shu; Superti, Fabiana; Schwander, Stephan; Gow, Andrew; Zhang, Junfeng (Jim); Chung, Kian Fan; Ryan, Mary P.; Porter, Alexandra E.; Tetley, Teresa D.

2015-01-01

The alveolar respiratory unit constitutes one of the main targets of inhaled nanoparticles; the effect of engineered nanomaterials (NMs) on human health is largely unknown. Surfactant protein D (SP-D) is synthesized by alveolar type II epithelial cells and released into respiratory secretions; its main function is in immune defence, notably against inhaled microbes. SP-D also plays an important role in modulating an appropriate inflammatory response in the lung, and reduced SP-D is associated with a number of inflammatory lung diseases. Adsorption of SP-D to inhaled NMs may facilitate their removal via macrophage phagocytosis. This study addresses the hypothesis that the chemistry, size and surface modification of engineered NMs will impact on their interaction with, and adsorption of, SP-D. To this purpose, we have examined the interactions between SP-D in human lung lavage and two NMs, carbon nanotubes and polystyrene nanoparticles, with different surface functionalization. We have demonstrated that particle size, functionalization and concentration affect the adsorption of SP-D from human lung lavage. Functionalization with negatively charged groups enhanced the amount of SP-D binding. While SP-D binding would be expected to enhance macrophage phagocytosis, these results suggest that the degree of binding is markedly affected by the physicochemistry of the NM and that deposition of high levels of some nanoparticles within the alveolar unit might deplete SP-D levels and affect alveolar immune defence mechanisms. PMID:25533095

Efficient and versatile one-step affinity purification of in vivo biotinylated proteins: Expression, characterization and structure analysis of recombinant human glutamate carboxypeptidase II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tykvart, J.; Sacha, P.; Barinka, C.

2012-02-07

Affinity purification is a useful approach for purification of recombinant proteins. Eukaryotic expression systems have become more frequently used at the expense of prokaryotic systems since they afford recombinant eukaryotic proteins with post-translational modifications similar or identical to the native ones. Here, we present a one-step affinity purification set-up suitable for the purification of secreted proteins. The set-up is based on the interaction between biotin and mutated streptavidin. Drosophila Schneider 2 cells are chosen as the expression host, and a biotin acceptor peptide is used as an affinity tag. This tag is biotinylated by Escherichia coli biotin-protein ligase in vivo.more » We determined that localization of the ligase within the ER led to the most effective in vivo biotinylation of the secreted proteins. We optimized a protocol for large-scale expression and purification of AviTEV-tagged recombinant human glutamate carboxypeptidase II (Avi-GCPII) with milligram yields per liter of culture. We also determined the 3D structure of Avi-GCPII by X-ray crystallography and compared the enzymatic characteristics of the protein to those of its non-tagged variant. These experiments confirmed that AviTEV tag does not affect the biophysical properties of its fused partner. Purification approach, developed here, provides not only a sufficient amount of highly homogenous protein but also specifically and effectively biotinylates a target protein and thus enables its subsequent visualization or immobilization.« less

CARD8 is a negative regulator for NLRP3 inflammasome, but mutant NLRP3 in cryopyrin-associated periodic syndromes escapes the restriction

PubMed Central

2014-01-01

Introduction NLRP3 plays a role in sensing various pathogen components or stresses in the innate immune system. Once activated, NLRP3 associates with apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and procaspase-1 to form a large protein complex termed inflammasome. Although some investigators have proposed a model of NLRP3-inflammasome containing an adaptor protein caspase recruitment domain-containing protein 8 (CARD8), the role of this molecule remains obscure. This study aimed to clarify the interaction between CARD8 and wild-type NLRP3 as well as mutant forms of NLRP3 linked with cryopyrin-associated periodic syndromes (CAPS). Methods In here HEK293 expression system, cells were transfected with the cDNAs for inflammasome components. Also used were peripheral blood mononuclear cells (PBMCs) and human monocyte-derived macrophages (HMDMs) from healthy volunteers. The interaction of CARD8 and NLRP3 was studied by immunoprecipitation. The effect of CARD8 expression on IL-1β secretion was assessed by ELISA. CARD8 knockdown experiments were carried out by transfection of the specific siRNA into HMDMs. Results In HEK293 cells, CARD8 interacted with wild-type NLRP3, but not with CAPS-associated mutant NLRP3. CARD8 significantly reduced IL-1β secretion from cells transfected with wild-type NLRP3, but not if they were transfected with mutant NLRP3. In addition, association of endogenously expressed CARD8 with NLRP3 was confirmed in resting PBMCs, and CARD8 knockdown resulted in higher amount of IL-1β secretion from HMDMs. Conclusions Until specific stimuli activate NLRP3, CARD8 holds NLRP3, and is supposed to prevent activation by subtle stimuli. However, CAPS-associated mutant NLRP3 is unable to bind with CARD8, which might be relevant to the pathogenesis of CAPS. PMID:24517500

CARD8 is a negative regulator for NLRP3 inflammasome, but mutant NLRP3 in cryopyrin-associated periodic syndromes escapes the restriction.

PubMed

Ito, Sayaka; Hara, Yukichi; Kubota, Tetsuo

2014-02-12

NLRP3 plays a role in sensing various pathogen components or stresses in the innate immune system. Once activated, NLRP3 associates with apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and procaspase-1 to form a large protein complex termed inflammasome. Although some investigators have proposed a model of NLRP3-inflammasome containing an adaptor protein caspase recruitment domain-containing protein 8 (CARD8), the role of this molecule remains obscure. This study aimed to clarify the interaction between CARD8 and wild-type NLRP3 as well as mutant forms of NLRP3 linked with cryopyrin-associated periodic syndromes (CAPS). In here HEK293 expression system, cells were transfected with the cDNAs for inflammasome components. Also used were peripheral blood mononuclear cells (PBMCs) and human monocyte-derived macrophages (HMDMs) from healthy volunteers. The interaction of CARD8 and NLRP3 was studied by immunoprecipitation. The effect of CARD8 expression on IL-1β secretion was assessed by ELISA. CARD8 knockdown experiments were carried out by transfection of the specific siRNA into HMDMs. In HEK293 cells, CARD8 interacted with wild-type NLRP3, but not with CAPS-associated mutant NLRP3. CARD8 significantly reduced IL-1β secretion from cells transfected with wild-type NLRP3, but not if they were transfected with mutant NLRP3. In addition, association of endogenously expressed CARD8 with NLRP3 was confirmed in resting PBMCs, and CARD8 knockdown resulted in higher amount of IL-1β secretion from HMDMs. Until specific stimuli activate NLRP3, CARD8 holds NLRP3, and is supposed to prevent activation by subtle stimuli. However, CAPS-associated mutant NLRP3 is unable to bind with CARD8, which might be relevant to the pathogenesis of CAPS.

Functional Characterization of Cultured Keratinocytes after Acute Cutaneous Burn Injury

PubMed Central

Gauglitz, Gerd G.; Zedler, Siegfried; v. Spiegel, Felix; Fuhr, Jasmin; v. Donnersmarck, Guido Henkel; Faist, Eugen

2012-01-01

Background In addition to forming the epithelial barrier against the outside environment keratinocytes are immunologically active cells. In the treatment of severely burned skin, cryoconserved keratinocyte allografts gain in importance. It has been proposed that these allografts accelerate wound healing also due to the expression of a favourable - keratinocyte-derived - cytokine and growth factor milieu. Methods In this study the morphology and cytokine expression profile of keratinocytes from skin after acute burn injury was compared to non-burned skin. Skin samples were obtained from patients after severe burn injury and healthy controls. Cells were cultured and secretion of selected inflammatory mediators was quantified using Bioplex Immunoassays. Immunohistochemistry was performed to analyse further functional and morphologic parameters. Results Histology revealed increased terminal differentiation of keratinocytes (CK10, CK11) in allografts from non-burned skin compared to a higher portion of proliferative cells (CK5, vimentin) in acute burn injury. Increased levels of IL-1α, IL-2, IL-4, IL-10, IFN-γ and TNFα could be detected in culture media of burn injury skin cultures. Both culture groups contained large amounts of IL-1RA. IL-6 and GM-CSF were increased during the first 15 days of culture of burned skin compared to control skin. Levels of VEGF, FGF-basic, TGF-ß und G-CSF were high in both but not significantly different. Cryoconservation led to a diminished mediator synthesis except for higher levels of intracellular IL-1α and IL-1ß. Conclusion Skin allografts from non-burned skin show a different secretion pattern of keratinocyte-derived cytokines and inflammatory mediators compared to keratinocytes after burn injury. As these secreted molecules exert auto- and paracrine effects and subsequently contribute to healing and barrier restoration after acute burn injury therapies affecting this specific cytokine/growth factor micromilieu could be beneficial in burned patients. PMID:22359539

A prohormone convertase cleavage site within a predicted alpha-helix mediates sorting of the neuronal and endocrine polypeptide VGF into the regulated secretory pathway.

PubMed

Garcia, Angelo L; Han, Shan-Kuo; Janssen, William G; Khaing, Zin Z; Ito, Timothy; Glucksman, Marc J; Benson, Deanna L; Salton, Stephen R J

2005-12-16

Distinct intracellular pathways are involved in regulated and constitutive protein secretion from neuronal and endocrine cells, yet the peptide signals and molecular mechanisms responsible for targeting and retention of soluble proteins in secretory granules are incompletely understood. By using confocal microscopy and subcellular fractionation, we examined trafficking of the neuronal and endocrine peptide precursor VGF that is stored in large dense core vesicles and undergoes regulated secretion. VGF cofractionated with secretory vesicle membranes but was not detected in detergent-resistant lipid rafts. Deletional analysis using epitope-tagged VGF suggested that the C-terminal 73-amino acid fragment of VGF, containing two predicted alpha-helical loops and four potential prohormone convertase (PC) cleavage sites, was necessary and sufficient with an N-terminal signal peptide-containing domain, for large dense core vesicle sorting and regulated secretion from PC12 and INS-1 cells. Further transfection analysis identified the sorting sequence as a compact C-terminal alpha-helix and embedded 564RRR566 PC cleavage site; mutation of the 564RRR566 PC site in VGF-(1-65): GFP:VGF-(545-617) blocked regulated secretion, whereas disruption of the alpha-helix had no effect. Mutation of the adjacent 567HFHH570 motif, a charged region that might enhance PC cleavage in acidic environments, also blocked regulated release. Finally, inhibition of PC cleavage in PC12 cells using the membrane-permeable synthetic peptide chloromethyl ketone (decanoyl-RVKR-CMK) blocked regulated secretion of VGF. Our studies define a critical RRR-containing C-terminal domain that targets VGF into the regulated pathway in neuronal PC12 and endocrine INS-1 cells, providing additional support for the proposed role that PCs and their cleavage sites play in regulated peptide secretion.

Inhibitory activity of diacylglycerol acyltransferase (DGAT) and microsomal triglyceride transfer protein (MTP) by the flavonoid, taxifolin, in HepG2 cells: potential role in the regulation of apolipoprotein B secretion.

PubMed

Casaschi, Adele; Rubio, Brent K; Maiyoh, Geoffrey K; Theriault, Andre G

2004-10-01

The purpose of the present study was to examine the role of taxifolin, a plant flavonoid, on several aspects involving apolipoprotein B (apoB) secretion and triglyceride (TG) availability in HepG2 cells. Taxifolin was shown by ELISA to markedly reduce apoB secretion under basal and lipid-rich conditions up to 63% at 200 micromol/L. As to the mechanism underlying this effect, we examined whether taxifolin exerted its effect by limiting TG availability in the microsomal lumen essential for lipoprotein assembly. Taxifolin was shown to inhibit microsomal TG synthesis by 37% and its subsequent transfer into the lumen (-26%). The reduction in synthesis was due to a decrease in diacylglycerol acyltransferase (DGAT) activity (-35%). The effect on DGAT activity was found to be non-competitive and non-transcriptional in nature. Both DGAT-1 and DGAT-2 mRNA expression remained essentially unchanged suggesting the point of regulation may be at the post-transcriptional level. Evidence is accumulating that microsomal triglyceride transfer protein (MTP) is also involved in determining the amount of lumenal TG available for lipoprotein assembly and secretion. Taxifolin was shown to inhibit this enzyme by 41%. Whether the reduction in TG accumulation in the microsomal lumen is predominantly due to DGAT and/or MTP activity remains to be addressed. In summary, taxifolin reduced apoB secretion by limiting TG availability via DGAT and MTP activity.

Synthesis and Secretion of Isoflavones by Field-Grown Soybean.

PubMed

Sugiyama, Akifumi; Yamazaki, Yumi; Hamamoto, Shoichiro; Takase, Hisabumi; Yazaki, Kazufumi

2017-09-01

Isoflavones play important roles in rhizosphere plant-microbe interactions. Daidzein and genistein secreted by soybean roots induce the symbiotic interaction with rhizobia and may modulate rhizosphere interactions with microbes. Yet despite their important roles, little is known about the biosynthesis, secretion and fate of isoflavones in field-grown soybeans. Here, we analyzed isoflavone contents and the expression of isoflavone biosynthesis genes in field-grown soybeans. In roots, isoflavone contents and composition did not change with crop growth, but the expression of UGT4, an isoflavone-specific 7-O-glucosyltransferase, and of ICHG (isoflavone conjugates hydrolyzing beta-glucosidase) was decreased during the reproductive stages. Isoflavone contents were higher in rhizosphere soil than in bulk soil during both vegetative and reproductive stages, and were comparable in the rhizosphere soil between these two stages. We analyzed the degradation dynamics of daidzein and its glucosides to develop a model for predicting rhizosphere isoflavone contents from the amount of isoflavones secreted in hydroponic culture. Conjugates of daidzein were degraded much faster than daidzein, with degradation rate constants of 8.51 d-1 for malonyldaidzin and 11.6 d-1 for daidzin, vs. 9.15 × 10-2 d-1 for daidzein. The model suggested that secretion of isoflavones into the rhizosphere is higher during vegetative stages than during reproductive stages in field-grown soybean. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Analysis of Bufo arenarum oviductal secretion during the sexual cycle.

PubMed

Crespo, Claudia A; Ramos, Inés; Medina, Marcela F; Fernández, Silvia N

2009-11-01

SummaryBufo arenarum oocytes are oviposited surrounded by jelly coats, one component of the extracellular matrix required for fertilization. The secretion, released to the oviductal lumen, was analysed by SDS-PAGE. The coomassie blue staining evidenced an electrophoretic pattern with molecules ranging between 300 and 19 kDa that showed variations in their secretion profiles during the sexual cycle. In the preovulatory period the densitometric analysis showed the presence of nine peaks with marked predominance of the 74 kDa molecule. Once ovulation has occurred, the jelly coats become arranged around the oocytes during their transit throughout the oviductal pars convoluta (PC), revealing the addition of three proteins only observed during this period, which suggests a differential secretion. Some of these proteins could not diffuse under any extraction treatment, indicating for them a structural or in situ function. Proteins of low molecular mass diffused totally while others showed a partial diffusing capacity. After ovulation a marked decrease in the relative amount of all the proteins released to the lumen, especially the 74 kDa protein, could be detected. During this period, unlike the other stages of the sexual cycle, a differential secretion pattern was observed along the PC. The histochemical analysis performed during the ovulatory period showed the presence of glycoconjugates including both acidic and neutral groups. The present results are in agreement with previous ultrastructural and histochemical studies that describe the role of Bufo arenarum jelly coats in fertilization.

Modelling the metabolism of protein secretion through the Tat route in Streptomyces lividans.

PubMed

Valverde, José R; Gullón, Sonia; Mellado, Rafael P

2018-06-14

Streptomyces lividans has demonstrated its value as an efficient host for protein production due to its ability to secrete functional proteins directly to the media. Secretory proteins that use the major Sec route need to be properly folded outside the cell, whereas secretory proteins using the Tat route appear outside the cell correctly folded. This feature makes the Tat system very attractive for the production of natural or engineered Tat secretory proteins. S. lividans cells are known to respond differently to overproduction and secretion of Tat versus Sec proteins. Increased understanding of the impact of protein secretion through the Tat route can be obtained by a deeper analysis of the metabolic impact associated with protein production, and its dependence on protein origin, composition, secretion mechanisms, growth phases and nutrients. Flux Balance Analysis of Genome-Scale Metabolic Network models provides a theoretical framework to investigate cell metabolism under different constraints. We have built new models for various S. lividans strains to better understand the mechanisms associated with overproduction of proteins secreted through the Tat route. We compare models of an S. lividans Tat-dependent agarase overproducing strain with those of the S. lividans wild-type, an S. lividans strain carrying the multi-copy plasmid vector and an α-amylase Sec-dependent overproducing strain. Using updated genomic, transcriptomic and experimental data we could extend existing S. lividans models and produce a new model which produces improved results largely extending the coverage of S. lividans strains, the number of genes and reactions being considered, the predictive behaviour and the dependence on specification of exchange constraints. Comparison of the optimized solutions obtained highlights numerous changes between Tat- and Sec-dependent protein secreting strains affecting the metabolism of carbon, amino acids, nucleotides, lipids and cofactors, and variability analysis predicts a large potential for protein overproduction. This work provides a detailed look to metabolic changes associated to Tat-dependent protein secretion reproducing experimental observations and identifying changes that are specific to each secretory route, presenting a novel, improved, more accurate and strain-independent model of S. lividans, thus opening the way for enhanced metabolic engineering of protein overproduction in S. lividans.

Depression of brain dopamine and its metabolite after mating in European honeybee (Apis mellifera) queens

NASA Astrophysics Data System (ADS)

Harano, Ken-Ichi; Sasaki, Ken; Nagao, Takashi

2005-07-01

To explore neuro-endocrinal changes in the brain of European honeybee (Apis mellifera) queens before and after mating, we measured the amount of several biogenic amines, including dopamine and its metabolite in the brain of 6- and 12-day-old virgins and 12-day-old mated queens. Twelve-day-old mated queens showed significantly lower amounts of dopamine and its metabolite (N-acetyldopamine) than both 6- and 12-day-old virgin queens, whereas significant differences in the amounts of these amines were not detected between 6- and 12-day-old virgin queens. These results are explained by down-regulation of both synthesis and secretion of brain dopamine after mating. It is speculated that higher amounts of brain dopamine in virgin queens might be involved in activation of ovarian follicles arrested in previtellogenic stages, as well as regulation of their characteristic behaviors.

Large-Capacity Three-Party Quantum Digital Secret Sharing Using Three Particular Matrices Coding

NASA Astrophysics Data System (ADS)

Lai, Hong; Luo, Ming-Xing; Pieprzyk, Josef; Tao, Li; Liu, Zhi-Ming; Orgun, Mehmet A.

2016-11-01

In this paper, we develop a large-capacity quantum digital secret sharing (QDSS) scheme, combined the Fibonacci- and Lucas-valued orbital angular momentum (OAM) entanglement with the recursive Fibonacci and Lucas matrices. To be exact, Alice prepares pairs of photons in the Fibonacci- and Lucas-valued OAM entangled states, and then allocates them to two participants, say, Bob and Charlie, to establish the secret key. Moreover, the available Fibonacci and Lucas values from the matching entangled states are used as the seed for generating the Fibonacci and Lucas matrices. This is achieved because the entries of the Fibonacci and Lucas matrices are recursive. The secret key can only be obtained jointly by Bob and Charlie, who can further recover the secret. Its security is based on the facts that nonorthogonal states are indistinguishable, and Bob or Charlie detects a Fibonacci number, there is still a twofold uncertainty for Charlie' (Bob') detected value. Supported by the Fundamental Research Funds for the Central Universities under Grant No. XDJK2016C043 and the Doctoral Program of Higher Education under Grant No. SWU115091, the National Natural Science Foundation of China under Grant No. 61303039, the Fundamental Research Funds for the Central Universities under Grant No. XDJK2015C153 and the Doctoral Program of Higher Education under Grant No. SWU114112, and the Financial Support the 1000-Plan of Chongqing by Southwest University under Grant No. SWU116007

Intracellular Action of a Secreted Peptide Required for Fungal Virulence.

PubMed

Homer, Christina M; Summers, Diana K; Goranov, Alexi I; Clarke, Starlynn C; Wiesner, Darin L; Diedrich, Jolene K; Moresco, James J; Toffaletti, Dena; Upadhya, Rajendra; Caradonna, Ippolito; Petnic, Sarah; Pessino, Veronica; Cuomo, Christina A; Lodge, Jennifer K; Perfect, John; Yates, John R; Nielsen, Kirsten; Craik, Charles S; Madhani, Hiten D

2016-06-08

Quorum sensing (QS) is a bacterial communication mechanism in which secreted signaling molecules impact population function and gene expression. QS-like phenomena have been reported in eukaryotes with largely unknown contributing molecules, functions, and mechanisms. We identify Qsp1, a secreted peptide, as a central signaling molecule that regulates virulence in the fungal pathogen Cryptococcus neoformans. QSP1 is a direct target of three transcription factors required for virulence, and qsp1Δ mutants exhibit attenuated infection, slowed tissue accumulation, and greater control by primary macrophages. Qsp1 mediates autoregulatory signaling that modulates secreted protease activity and promotes cell wall function at high cell densities. Peptide production requires release from a secreted precursor, proQsp1, by a cell-associated protease, Pqp1. Qsp1 sensing requires an oligopeptide transporter, Opt1, and remarkably, cytoplasmic expression of mature Qsp1 complements multiple phenotypes of qsp1Δ. Thus, C. neoformans produces an autoregulatory peptide that matures extracellularly but functions intracellularly to regulate virulence. Copyright © 2016 Elsevier Inc. All rights reserved.

Lipids of the anal sac secretions of the red fox, Vulpes vulpes and of the lion, Panthera leo.

PubMed

Albone, E S; Grönnerberg, T O

1977-07-01

Lion anal sac secretion were found to be richer in lipids and to contain more complex less uniform mixtures of lower moleculas weight lipids then the anal sac of the red fox. In the lion, homologous series of 1-alkylglycerols and 2-hydroxy-fatty acids were identified. Phenylacetic, 3-phenylpropionic, and related hydroxylated acids were also observed. Gas-liquid chromatography profiles of fox anal sac secretion lower molecular weight lipids were found to be less variable in their major constituents and to be dominated by relatively few large peaks, mainly (derivatized) fatty acids. Indole was also identified. Free cholesterol, and occasionally, stanols were observed in fox and lion secretions. In the red fox, total cholesterol levels averaged 0.93 mg/g (% free, 56.4), n = 5. Findings are discussed in relation to histological and anatomical similarities and differences between the anal sacs of the lion and the fox and in the context of the role of these secretions in chemical communication.

Quantifying expert consensus against the existence of a secret, large-scale atmospheric spraying program

NASA Astrophysics Data System (ADS)

Shearer, Christine; West, Mick; Caldeira, Ken; Davis, Steven J.

2016-08-01

Nearly 17% of people in an international survey said they believed the existence of a secret large-scale atmospheric program (SLAP) to be true or partly true. SLAP is commonly referred to as ‘chemtrails’ or ‘covert geoengineering’, and has led to a number of websites purported to show evidence of widespread chemical spraying linked to negative impacts on human health and the environment. To address these claims, we surveyed two groups of experts—atmospheric chemists with expertize in condensation trails and geochemists working on atmospheric deposition of dust and pollution—to scientifically evaluate for the first time the claims of SLAP theorists. Results show that 76 of the 77 scientists (98.7%) that took part in this study said they had not encountered evidence of a SLAP, and that the data cited as evidence could be explained through other factors, including well-understood physics and chemistry associated with aircraft contrails and atmospheric aerosols. Our goal is not to sway those already convinced that there is a secret, large-scale spraying program—who often reject counter-evidence as further proof of their theories—but rather to establish a source of objective science that can inform public discourse.

Structural and functional dissection reveals distinct roles of Ca2+-binding sites in the giant adhesin SiiE of Salmonella enterica

PubMed Central

Klingl, Stefan; Sandmann, Achim; Taccardi, Nicola; Sticht, Heinrich; Muller, Yves A.; Hensel, Michael

2017-01-01

The giant non-fimbrial adhesin SiiE of Salmonella enterica mediates the first contact to the apical site of epithelial cells and enables subsequent invasion. SiiE is a 595 kDa protein composed of 53 repetitive bacterial immunoglobulin (BIg) domains and the only known substrate of the SPI4-encoded type 1 secretion system (T1SS). The crystal structure of BIg50-52 of SiiE revealed two distinct Ca2+-binding sites per BIg domain formed by conserved aspartate or glutamate residues. In a mutational analysis Ca2+-binding sites were disrupted by aspartate to serine exchange at various positions in the BIg domains of SiiE. Amounts of secreted SiiE diminish with a decreasing number of intact Ca2+-binding sites. BIg domains of SiiE contain distinct Ca2+-binding sites, with type I sites being similar to other T1SS-secreted proteins and type II sites newly identified in SiiE. We functionally and structurally dissected the roles of type I and type II Ca2+-binding sites in SiiE, as well as the importance of Ca2+-binding sites in various positions of SiiE. Type I Ca2+-binding sites were critical for efficient secretion of SiiE and a decreasing number of type I sites correlated with reduced secretion. Type II sites were less important for secretion, stability and surface expression of SiiE, however integrity of type II sites in the C-terminal portion was required for the function of SiiE in mediating adhesion and invasion. PMID:28558023

Honeybee Foraging, Nectar Secretion, and Honey Potential of Wild Jujube Trees, Ziziphus nummularia.

PubMed

Alqarni, A S

2015-06-01

Ziziphus trees are of economic importance due to their aggregated value (source of fruits and timber) and are the most important melliferous plants in the Arabian Peninsula. Interaction between honeybees and Ziziphus nummularia was investigated by assessing foraging, flower phenology, nectar secretion, and honey potential. It is demonstrate that both the native Apis mellifera jemenitica Ruttner and the exotic Apis mellifera carnica Pollmann foraged on Z. nummularia flowers. Bee foraging for nectar and pollen was low (2 ± 0.7 workers/200 flowers/3 min) during early morning and increased to a peak in the afternoon (100 ± 15 workers/200 flowers/3 min). Remarkable foraging activity was recorded during high temperature (35°C) and low humidity (20%) conditions. Foraging for nectar collection was more distinct than that for pollen. The flowering of Z. nummularia was gradual, and was characterized by some flowers that opened and secreted nectar early before sunrise, whereas other flowers remained opened until sunrise. The flowers lasted 2 days, with 83% of nectar secreted in the first day. The peak of nectar secretion was recorded at noon under hot and dry conditions. The lowest amount of nectar was secreted during sunrise under mild temperature (24°C) and humidity (31%) conditions. Under optimum conditions, it is assumed that the average sugar mass was 0.321 ± 0.03 mg TSS/flower, while the total sugar mass was 27.65 ± 11 g/tree. The average honey production potential of tested Z. nummularia was approximately 2.998 kg/tree and 749.475 kg/ha in the main flowering season.

Physical exercise and menstrual cycle alterations. What are the mechanisms?

PubMed

Keizer, H A; Rogol, A D

1990-10-01

The prevalence of menstrual cycle alterations in athletes is considerably higher than in sedentary controls. There appears to be a multicausal aetiology, which makes it extremely difficult to dissociate the effects of physical exercise on the menstrual cycle from the other predisposing factors. From cross-sectional studies it appeared that physical training eventually might lead to shortening of the luteal phase and secondary amenorrhoea. Prospective studies in both trained and previously untrained women have shown that the amount and/or the intensity of exercise has to exceed a certain limit in order to elicit this phenomenon. We hypothesise, therefore, that apart from a certain predisposition, athletes with a training-induced altered menstrual cycle are overreached (short term overtraining, which is reversible in days to weeks after training reduction). Menstrual cycle alterations are most likely caused by subtle changes in the episodic secretion pattern of luteinising hormone (LH) as have been found in sedentary women with hypothalamic amenorrhoea as well as in athletes after very demanding training. The altered LH secretion then, might be caused by an increased corticotrophin-releasing hormone (CRH) secretion which inhibits the gonadotrophin-releasing hormone (GnRH) release. In addition, increased CRH tone will lead to increased beta-endorphin levels which will also inhibit the GnRH signaller. Finally, the continuous activation of the adrenals will result in a higher catecholamine production, which may be converted to catecholestrogens. These compounds are known to be potent inhibitors of GnRH secretion. In conclusion, menstrual cycle alterations are likely to occur after very demanding training, which causes an increase secretion of antireproductive hormones. These hormones can inhibit the normal pulsatile secretion pattern of the gonadotrophins.

Synergistic action of cyclic adenosine monophosphate- and calcium-mediated chloride secretion in a colonic epithelial cell line.

PubMed Central

Cartwright, C A; McRoberts, J A; Mandel, K G; Dharmsathaphorn, K

1985-01-01

Vasoactive intestinal polypeptide (VIP) and the calcium ionophore A23187 caused dose-dependent changes in the potential difference and the short circuit current (Isc) across confluent T84 cell monolayers mounted in modified Ussing chambers. Both VIP and A23187 stimulated net chloride secretion without altering sodium transport. Net chloride secretion accounted for the increase in Isc. When A23187 was tested in combination with VIP, net chloride secretion was significantly greater than predicted from the calculated sum of their individual responses indicating a synergistic effect. VIP increased cellular cyclic AMP (cAMP) production in a dose-dependent manner, whereas A23187 had no effect on cellular cAMP. We then determined whether VIP and A23187 activated different transport pathways. Earlier studies suggest that VIP activates a basolaterally localized, barium-sensitive potassium channel as well as an apically localized chloride conductance pathway. In this study, stimulation of basolateral membrane potassium efflux by A23187 was documented by preloading the monolayers with 86Rb+. Stimulation of potassium efflux by A23187 was additive to the VIP-stimulated potassium efflux. By itself, 0.3 microM A23187 did not alter transepithelial chloride permeability, and its stimulation of basolateral membrane potassium efflux caused only a relatively small amount of chloride secretion. However, in the presence of an increased transepithelial chloride permeability induced by VIP, the effectiveness of A23187 on chloride secretion was greatly augmented. Our studies suggest that cAMP and calcium each activate basolateral potassium channels, but cAMP also activates an apically localized chloride channel. Synergism results from cooperative interaction of potassium channels and the chloride channel. PMID:2997291

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

PubMed Central

Coulette, Quentin; Lemauf, Séverine; Colinet, Dominique; Prévost, Geneviève; Anselme, Caroline; Poirié, Marylène

2017-01-01

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 (αβ)2 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. PMID:28742131

Decreased catecholamine secretion from the adrenal medullae of chronically diabetic BB-Wistar rats

NASA Technical Reports Server (NTRS)

Wilke, R. A.; Riley, D. A.; Lelkes, P. I.; Hillard, C. J.

1993-01-01

Many humans with IDDM eventually lose the capacity to secrete epinephrine from their adrenal medullae. The mechanism for this pathological change is unknown. We hypothesized that this abnormality is attributable to neuropathic changes in the greater splanchnic nerves or in the chromaffin cells that they innervate. To study this hypothesis, we isolated rat adrenal glands, perfused them ex vivo, and measured the epinephrine content of the perfusate under various conditions of stimulation. We used transmural electrical stimulation (20-80 V, at 10 Hz) to induce epinephrine secretion indirectly by selectively activating residual splanchnic nerve terminals within the isolated glands. Under these conditions, epinephrine secretion was severely attenuated in glands from female BB-Wistar rats with diabetes of 4 mo duration compared with their age-matched, nondiabetic controls. These perfused diabetic adrenal medullae also demonstrated decreased catecholamine release in response to direct chromaffin cell depolarization with 20 mM K+, evidence that a functional alteration exists within the chromaffin cells themselves. Nonetheless, total catecholamine content of adrenal medullae from these diabetic rats was not significantly different from controls, indicating that the secretory defect was not simply attributable to a difference in the amount of catecholamines stored and available for release. Herein, we also provide histological evidence of degenerative changes within the cholinergic nerve terminals that innervate these glands.

A dopamine receptor d2-type agonist attenuates the ability of stress to alter sleep in mice.

PubMed

Jefferson, F; Ehlen, J C; Williams, N S; Montemarano, J J; Paul, K N

2014-11-01

Although sleep disruptions that accompany stress reduce quality of life and deteriorate health, the mechanisms through which stress alters sleep remain obscure. Psychological stress can alter sleep in a variety of ways, but it has been shown to be particularly influential on rapid eye movement (REM) sleep. Prolactin (PRL), a sexually dimorphic, stress-sensitive hormone whose basal levels are higher in females, has somnogenic effects on REM sleep. In the current study, we examined the relationship between PRL secretion and REM sleep after restraint stress to determine whether: 1) the ability of stress to increase REM sleep is PRL-dependent, and 2) fluctuating PRL levels underlie sex differences in sleep responses to stress. Because dopamine D2 receptors in the pituitary gland are the primary regulator of PRL secretion, D2 receptor agonist, 1-[(6-allylergolin-8β-yl)-carbonyl]-1-[3-(dimethylamino) propyl]-3-ethylurea (cabergoline), was used to attenuate PRL levels in mice before 1 hour of restraint stress. Mice were implanted with electroencephalographic/electromyographic recording electrodes and received an ip injection of either 0.3-mg/kg cabergoline or vehicle before a control procedure of 1 hour of sleep deprivation by gentle handling during the light phase. Six days after the control procedure, mice received cabergoline or vehicle 15 minutes before 1 hour of restraint stress. Cabergoline blocked the ability of restraint stress to increase REM sleep amount in males but did not alter REM sleep amount after stress in females even though it reduced basal REM sleep amount in female controls. These data provide evidence that the ability for restraint stress to increase REM sleep is dependent on PRL and that sex differences in REM sleep amount may be driven by PRL.

Substrate adaptation of Trichophyton rubrum secreted endoproteases.

PubMed

Chen, Jian; Yi, Jinling; Liu, Li; Yin, Songchao; Chen, Rongzhang; Li, Meirong; Ye, Congxiu; Zhang, Yu-qing; Lai, Wei

2010-02-01

Trichophyton rubrum is the most common pathogen caused the dermatophytosis of nail and skin in human. The secreted proteases were considered to be the most important virulence factors. However, the substrates adaptation of T. rubrum secreted proteases is largely unknown. For the first time, we use the keratins from human nail and skin stratum corneum as the growth medium to investigate the different expression patterns of T. rubrum secreted endoproteases genes. During grow in both keratin-containing media SUB7 and MEP2 were the highest expressed gene in each family. These results indicated that SUB7 and MEP2 may be the dominant endoproteases secreted by T. rubrum during host infection and the other proteases may play a supplementary role. The direct comparison of T. rubrum grown on skin and nail medium showed different substrate favorite of secreted endoproteases. The genes MEP2, SUB5, SUB2 and SUB3 were more active during growth in skin medium, possibly these proteases have a higher affinity for skin original keratins. While the structures of SUB1, SUB4, and MEP4 maybe more suitable for the degradation of nail original keratins. This work presents useful molecular details for further understanding the pathogenesis of secreted proteases and the wide adaptation of T. rubrum.

System Specificity of the TpsB Transporters of Coexpressed Two-Partner Secretion Systems of Neisseria meningitidis

PubMed Central

ur Rahman, Sadeeq

2013-01-01

The two-partner secretion (TPS) systems of Gram-negative bacteria consist of a large secreted exoprotein (TpsA) and a transporter protein (TpsB) located in the outer membrane. TpsA targets TpsB for transport across the membrane via its ∼30-kDa TPS domain located at its N terminus, and this domain is also the minimal secretory unit. Neisseria meningitidis genomes encode up to five TpsAs and two TpsBs. Sequence alignments of TPS domains suggested that these are organized into three systems, while there are two TpsBs, which raised questions on their system specificity. We show here that the TpsB2 transporter of Neisseria meningitidis is able to secrete all types of TPS domains encoded in N. meningitidis and the related species Neisseria lactamica but not domains of Haemophilus influenzae and Pseudomonas aeruginosa. In contrast, the TpsB1 transporter seemed to be specific for its cognate N. meningitidis system and did not secrete the TPS domains of other meningococcal systems. However, TpsB1 did secrete the TPS2b domain of N. lactamica, which is related to the meningococcal TPS2 domains. Apparently, the secretion depends on specific sequences within the TPS domain rather than the overall TPS domain structure. PMID:23222722

The Secretion of Oxygen into the Swim-bladder of Fish

PubMed Central

Wittenberg, Jonathan B.; Wittenberg, Beatrice A.

1961-01-01

Toadfish, Opsanus tau, L., were maintained in sea water equilibrated with gas mixtures containing a fixed proportion of oxygen and varying proportions of carbon monoxide. The swim-bladder was emptied by puncture, and, after an interval of 24 or 48 hours, the newly secreted gases were withdrawn and analyzed. Both carbon monoxide and oxygen are accumulated in the swim-bladder at tensions greater than ambient. The ratio of concentrations, carbon monoxide (secreted): carbon monoxide (administered) bears a constant relation to the ratio, oxygen (secreted): oxygen (administered). The value of the partition coefficient describing this relation is (α = 5.44). The two gases are considered to compete for a common intracellular carrier mediating their active transport. The suggestion is advanced that the intracellular oxygen carrier is a hemoglobin. Comparison of the proportions of carboxy- and oxyhemoglobin in the blood with the composition of the secreted gas proves that the secreted gases are not evolved directly from combination with blood hemoglobin. The suggestion is advanced that cellular oxygen secretion occurs in the rete mirabile: the rete may build up large oxygen tensions in the gas gland capillaries. It is suggested that the gas gland acts as a valve impeding back diffusion of gases from the swim-bladder. PMID:13786093

Integrated Bottom-Up and Top-Down Liquid Chromatography-Mass Spectrometry for Characterization of Recombinant Human Growth Hormone Degradation Products.

PubMed

Wang, Yu Annie; Wu, Di; Auclair, Jared R; Salisbury, Joseph P; Sarin, Richa; Tang, Yang; Mozdzierz, Nicholas J; Shah, Kartik; Zhang, Anna Fan; Wu, Shiaw-Lin; Agar, Jeffery N; Love, J Christopher; Love, Kerry R; Hancock, William S

2017-12-05

With the advent of biosimilars to the U.S. market, it is important to have better analytical tools to ensure product quality from batch to batch. In addition, the recent popularity of using a continuous process for production of biopharmaceuticals, the traditional bottom-up method, alone for product characterization and quality analysis is no longer sufficient. Bottom-up method requires large amounts of material for analysis and is labor-intensive and time-consuming. Additionally, in this analysis, digestion of the protein with enzymes such as trypsin could induce artifacts and modifications which would increase the complexity of the analysis. On the other hand, a top-down method requires a minimum amount of sample and allows for analysis of the intact protein mass and sequence generated from fragmentation within the instrument. However, fragmentation usually occurs at the N-terminal and C-terminal ends of the protein with less internal fragmentation. Herein, we combine the use of the complementary techniques, a top-down and bottom-up method, for the characterization of human growth hormone degradation products. Notably, our approach required small amounts of sample, which is a requirement due to the sample constraints of small scale manufacturing. Using this approach, we were able to characterize various protein variants, including post-translational modifications such as oxidation and deamidation, residual leader sequence, and proteolytic cleavage. Thus, we were able to highlight the complementarity of top-down and bottom-up approaches, which achieved the characterization of a wide range of product variants in samples of human growth hormone secreted from Pichia pastoris.

Can GLP-1 preparations be used in children and adolescents with diabetes mellitus?

PubMed

Shehadeh, Naim; Daich, Eena; Zuckerman-Levin, Nehama

2014-03-01

The number of young diabetics is increasing and therapeutic options for these patients are limited. Glucagon-like peptide-1 (GLP-1) is secreted from the gut after meals and enhances glucose-induced insulin secretion, inhibits glucagon secretion, suppresses appetite, and delays the gastric-emptying rate. GLP-1 analogs are already widely used in the adult population to improve glycemic control and induce weight loss in overweight subjects with type 2 diabetes. The glucose-lowering effects resulting from the inhibition of glucagon secretion and the gastric-emptying rate could be of clinical importance in type 1 diabetes. In this article we review clinical data regarding the use of GLP-1 receptor agonists in youth and address the potential benefits and safety aspects of these compounds. Large scale clinical trials are still needed in the pediatric population.

Species variation in biology and physiology of the ciliary epithelium: similarities and differences.

PubMed

Do, Chi Wai; Civan, Mortimer M

2009-04-01

Glaucoma is a leading cause of irreversible blindness worldwide. Lowering intraocular pressure (IOP) is the only strategy documented to delay the appearance and retard the progression of vision loss. One major approach for lowering IOP is to slow the rate of aqueous humor formation by the ciliary epithelium. As discussed in the present review, the transport basis for this secretion is largely understood. However, several substantive issues are yet to be resolved, including the integrated regulation of secretion, the functional topography of the ciliary epithelium, and the degree and significance of species variation in aqueous humor inflow. This review discusses species differences in net secretion, particularly of Cl(-) and HCO(3)(-) secretion. Identifying animal models most accurately mimicking aqueous humor formation in the human will facilitate development of future novel initiatives to lower IOP.

Novel evidence that nitric oxide of the medial septal area influences the salivary secretion induced by pilocarpine.

PubMed

Saad, Wilson Abrão; Guarda, Ismael Francisco Motta Siqueira; Camargo, Luiz Antonio de Arruda; dos Santos, Talmir Augusto Faria Brisola; Saad, William Abrão; Simões, Sylvio; Guarda, Renata Saad

2002-04-05

Our studies have focused on the effect of injection of L-NAME and sodium nitroprussiate (SNP) on the salivary secretion, arterial blood pressure, sodium excretion and urinary volume induced by pilocarpine which was injected into the medial septal area (MSA). Rats were anesthetized with urethane (1.25 g/kg b. wt.) and a stainless steel cannula was implanted into their MSA. The amount of saliva secretion was studied over a five-minute period after injection of pilocarpine into MSA. Injection of pilocarpine (10, 20, 40, 80, 160 microg/microl) into MSA produced a dose-dependent increase in salivary secretion. L-NG-nitro arginine methyl-esther (L-NAME) (40 microg/microl), a nitric oxide (NO) synthase inhibitor, was injected into MSA prior to the injection of pilocarpine into MSA, producing an increase in salivary secretion due to the effect of pilocarpine. Sodium nitroprussiate (SNP) (30 microg/microl) was injected into MSA prior to the injection of pilocarpine into MSA attenuating the increase in salivary secretion induced by pilocarpine. Medial arterial pressure (MAP) increase after injections of pilocarpine into the MSA. L-NAME injected into the MSA prior to injection of pilocarpine into MSA increased the MAP. SNP injected into the MSA prior to pilocarpine attenuated the effect of pilocarpine on MAP. Pilocarpine (40 ug/ul) injected into the MAS induced an increase in sodium and urinary excretion. L-NAME injected prior to pilocarpine into the MSA increased the urinary sodium excretion and urinary volume induced by pilocarpine. SNP injected prior to pilocarpine into the MSA decreased the sodium excretion and urinary volume induced by pilocarpine. All these roles of pilocarpine depend on the release of nitric oxide into the MSA. We may also conclude that the MSA is involved with the cholinergic excitatory mechanism that induce salivary secretion, increase in MAP and increase in sodium excretion and urinary volume.

Effects of growth hormone and insulin-like growth factor 1 deficiency on ageing and longevity.

PubMed

Laron, Zvi

2002-01-01

Present knowledge on the effects of growth hormone (GH)/insulin-like growth hormone (IGF)1 deficiency on ageing and lifespan are reviewed. Evidence is presented that isolated GH deficiency (IGHD), multiple pituitary hormone deficiencies (MPHD) including GH, as well as primary IGE1 deficiency (GH resistance, Laron syndrome) present signs of early ageing such as thin and wrinkled skin, obesity, hyperglycemia and osteoporosis. These changes do not seem to affect the lifespan, as patients reach old age. Animal models of genetic MPHD (Ames and Snell mice) and GH receptor knockout mice (primary IGF1 deficiency) also have a statistically significant higher longevity compared to normal controls. On the contrary, mice transgenic for GH and acromegalic patients secreting large amounts of GH have premature death. In conclusion longstanding GH/IGF1 deficiency affects several parameters of the ageing process without impairing lifespan, and as shown in animal models prolongs longevity. In contrast high GH/IGF1 levels accelerate death.

The unconventional antimicrobial peptides of the classical propionibacteria.

PubMed

Faye, Therese; Holo, Helge; Langsrud, Thor; Nes, Ingolf F; Brede, Dag A

2011-02-01

The classical propionibacteria produce genetically unique antimicrobial peptides, whose biological activities are without equivalents, and to which there are no homologous sequences in public databases. In this review, we summarize the genetics, biochemistry, biosynthesis, and biological activities of three extensively studied antimicrobial peptides from propionibacteria. The propionicin T1 peptide constitutes a bona fide example of an unmodified general secretory pathway (sec)-dependent bacteriocin, which is bactericidal towards all tested species of propionibacteria except Propionibacterium freudenreichii. The PAMP antimicrobial peptide represents a novel concept within bacterial antagonism, where an inactive precursor protein is secreted in large amounts, and which activation appears to rely on subsequent processing by proteases in its resident milieu. Propionicin F is a negatively charged bacteriocin that displays an intraspecies bactericidal inhibition spectrum. The biosynthesis of propionicin F appears to proceed through a series of unusual events requiring both N- and C-terminal processing of a precursor protein, which probably requires the radical SAM superfamily enzyme PcfB.

Branched-chain ketoacids secreted by glioblastoma cells via MCT1 modulate macrophage phenotype.

PubMed

Silva, Lidia Santos; Poschet, Gernot; Nonnenmacher, Yannic; Becker, Holger M; Sapcariu, Sean; Gaupel, Ann-Christin; Schlotter, Magdalena; Wu, Yonghe; Kneisel, Niclas; Seiffert, Martina; Hell, Rüdiger; Hiller, Karsten; Lichter, Peter; Radlwimmer, Bernhard

2017-12-01

Elevated amino acid catabolism is common to many cancers. Here, we show that glioblastoma are excreting large amounts of branched-chain ketoacids (BCKAs), metabolites of branched-chain amino acid (BCAA) catabolism. We show that efflux of BCKAs, as well as pyruvate, is mediated by the monocarboxylate transporter 1 (MCT1) in glioblastoma. MCT1 locates in close proximity to BCKA-generating branched-chain amino acid transaminase 1, suggesting possible functional interaction of the proteins. Using in vitro models, we demonstrate that tumor-excreted BCKAs can be taken up and re-aminated to BCAAs by tumor-associated macrophages. Furthermore, exposure to BCKAs reduced the phagocytic activity of macrophages. This study provides further evidence for the eminent role of BCAA catabolism in glioblastoma by demonstrating that tumor-excreted BCKAs might have a direct role in tumor immune suppression. Our data further suggest that the anti-proliferative effects of MCT1 knockdown observed by others might be related to the blocked excretion of BCKAs. © 2017 The Authors.

Quality and utilization of food co-products and residues

NASA Astrophysics Data System (ADS)

Cooke, P.; Bao, G.; Broderick, C.; Fishman, M.; Liu, L.; Onwulata, C.

2010-06-01

Some agricultural industries generate large amounts of low value co-products/residues, including citrus peel, sugar beet pulp and whey protein from the production of orange juice, sugar and cheese commodities, respectively. National Program #306 of the USDA Agricultural Research Service aims to characterize and enhance quality and develop new processes and uses for value-added foods and bio-based products. In parallel projects, we applied scanning microscopies to examine the molecular organization of citrus pectin gels, covalent crosslinking to reduce debonding in sugar beet pulp-PLA composites and functional modification of whey protein through extrusion in order to evaluate new methods of processing and formulating new products. Also, qualitative attributes of fresh produce that could potentially guide germ line development and crop management were explored through fluorescence imaging: synthesis and accumulation of oleoresin in habanero peppers suggest a complicated mechanism of secretion that differs from the classical scheme. Integrated imaging appears to offer significant structural insights to help understand practical properties and features of important food co-products/residues.

Image steganalysis using Artificial Bee Colony algorithm

NASA Astrophysics Data System (ADS)

Sajedi, Hedieh

2017-09-01

Steganography is the science of secure communication where the presence of the communication cannot be detected while steganalysis is the art of discovering the existence of the secret communication. Processing a huge amount of information takes extensive execution time and computational sources most of the time. As a result, it is needed to employ a phase of preprocessing, which can moderate the execution time and computational sources. In this paper, we propose a new feature-based blind steganalysis method for detecting stego images from the cover (clean) images with JPEG format. In this regard, we present a feature selection technique based on an improved Artificial Bee Colony (ABC). ABC algorithm is inspired by honeybees' social behaviour in their search for perfect food sources. In the proposed method, classifier performance and the dimension of the selected feature vector depend on using wrapper-based methods. The experiments are performed using two large data-sets of JPEG images. Experimental results demonstrate the effectiveness of the proposed steganalysis technique compared to the other existing techniques.

N-Glycosylation of an IgG antibody secreted by Nicotiana tabacum BY-2 cells can be modulated through co-expression of human β-1,4-galactosyltransferase.

PubMed

Navarre, Catherine; Smargiasso, Nicolas; Duvivier, Laurent; Nader, Joseph; Far, Johann; De Pauw, Edwin; Boutry, Marc

2017-06-01

Nicotiana tabacum BY-2 suspension cells have several advantages that make them suitable for the production of full-size monoclonal antibodies which can be purified directly from the culture medium. Carbohydrate characterization of an antibody (Lo-BM2) expressed in N. tabacum BY-2 cells showed that the purified Lo-BM2 displays N-glycan homogeneity with a high proportion (>70%) of the complex GnGnXF glycoform. The stable co-expression of a human β-1,4-galactosyltransferase targeted to different Golgi sub-compartments altered Lo-BM2N-glycosylation and resulted in the production of an antibody that exhibited either hybrid structures containing a low abundance of the plant epitopes (α-1,3-fucose and β-1,2-xylose), or a large amount of galactose-extended N-glycan structures. These results demonstrate the suitability of stable N-glycoengineered N. tabacum BY-2 cell lines for the production of human-like antibodies.

IL-17+ γδ T cells as kick-starters of inflammation.

PubMed

Papotto, Pedro H; Ribot, Julie C; Silva-Santos, Bruno

2017-05-18

Shortly after the discovery of interleukin 17 (IL-17)-producing CD4 + helper T cells (T H 17 cells), it was found that γδ T cells can also secrete large amounts of this pro-inflammatory cytokine. A decade later, it is now known that IL-17 + γδ T cells (γδ17 T cells) are often the main providers of IL-17A in various models of inflammatory diseases, while they also contribute to protective immune responses to infectious organisms. Due to an intricate thymic program of differentiation, γδ17 T cells are able to respond faster than T H 17 cells do and thus predominate in the early stages of inflammatory responses. Here we review the current knowledge of the development, activation and pathophysiological functions of γδ17 T cells, aiming to increase the awareness in the community of the therapeutic potential of this 'other side' of IL-17-mediated immune responses.

Regulation of the Cardiovascular System by Histamine.

PubMed

Hattori, Yuichi; Hattori, Kohshi; Matsuda, Naoyuki

2017-01-01

Histamine mediates a wide range of cellular responses, including allergic and inflammatory reactions, gastric acid secretion, and neurotransmission in the central nervous system. Histamine also exerts a series of actions upon the cardiovascular system but may not normally play a significant role in regulating cardiovascular function. During tissue injury, inflammation, and allergic responses, mast cells (or non-mast cells) within the tissues can release large amounts of histamine that leads to noticeable cardiovascular effects. Owing to intensive research during several decades, the distribution, function, and pathophysiological role of cardiovascular H 1 - and H 2 -receptors has become recognized adequately. Besides the recognized H 1 - and H 2 -receptor-mediated cardiovascular responses, novel roles of H 3 - and H 4 -receptors in cardiovascular physiology and pathophysiology have been identified over the last decade. In this review, we describe recent advances in our understanding of cardiovascular function and dysfunction mediated by histamine receptors, including H 3 - and H 4 -receptors, their potential mechanisms of action, and their pathological significance.

Comprehensive metabolomic, lipidomic and microscopic profiling of Yarrowia lipolytica during lipid accumulation identifies targets for increased lipogenesis

DOE PAGES

Pomraning, Kyle R.; Wei, Siwei; Karagiosis, Sue A.; ...

2015-04-23

Yarrowia lipolytica is an oleaginous ascomycete yeast that accumulates large amounts of lipids and has potential as a biofuel producing organism. Despite a growing scientific literature focused on lipid production by Y. lipolytica, there remain significant knowledge gaps regarding the key biological processes involved. We applied a combination of metabolomic and lipidomic profiling approaches as well as microscopic techniques to identify and characterize the key pathways involved in de novo lipid accumulation from glucose in batch cultured, wild-type Y. lipolytica. We found that lipids accumulated rapidly and peaked at 48 hours during the five day experiment, concurrent with a shiftmore » in amino acid metabolism. We also report that Y. lipolytica secretes disaccharides early in batch culture and reabsorbs them when extracellular glucose is depleted. Exhaustion of extracellular sugars coincided with thickening of the cell wall, suggesting that genes involved in cell wall biogenesis may be a useful target for improving the efficiency of lipid producing yeast strains.« less

Recombinant protein expression for structural biology in HEK 293F suspension cells: a novel and accessible approach.

PubMed

Portolano, Nicola; Watson, Peter J; Fairall, Louise; Millard, Christopher J; Milano, Charles P; Song, Yun; Cowley, Shaun M; Schwabe, John W R

2014-10-16

The expression and purification of large amounts of recombinant protein complexes is an essential requirement for structural biology studies. For over two decades, prokaryotic expression systems such as E. coli have dominated the scientific literature over costly and less efficient eukaryotic cell lines. Despite the clear advantage in terms of yields and costs of expressing recombinant proteins in bacteria, the absence of specific co-factors, chaperones and post-translational modifications may cause loss of function, mis-folding and can disrupt protein-protein interactions of certain eukaryotic multi-subunit complexes, surface receptors and secreted proteins. The use of mammalian cell expression systems can address these drawbacks since they provide a eukaryotic expression environment. However, low protein yields and high costs of such methods have until recently limited their use for structural biology. Here we describe a simple and accessible method for expressing and purifying milligram quantities of protein by performing transient transfections of suspension grown HEK (Human Embryonic Kidney) 293 F cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amagai, Yosuke; Tanaka, Akane; Ohmori, Keitaro

Much is known regarding participations of mast cells with innate and acquired immunity by secreting various cytokines and chemical mediators. However, details of mast cell biology still remain unclear. In this study, we successfully established a novel growth factor-independent mast cell line (MPT-1) derived from canine mast cell tumor. MPT-1 cells manifested factor-independent proliferation as floating cells containing a large amount of histamine, as well as chymase-like dog mast cell protease 3, in cytosolic granules. Particularly, MPT-1 cells expressed high-affinity IgE receptors (Fc{epsilon}RI) and wild-type c-kit receptors. Degranulation of MPT-1 cells was induced not only by stimulation with calcium ionophoremore » but also by cross-linkage of the surface IgE. Given that MPT-1 is the first mast cell line with Fc{epsilon}RI which has no c-kit mutations, MPT-1 cells may provide great contribution for investigation of IgE-mediated activation mechanisms of mast cells, leading to development of effective treatment for allergic disorders.« less

Optimization of Nutrients and Culture Conditions for Alkaline Protease Production Using Two Endophytic Micrococci: Micrococcus aloeverae and Micrococcus yunnanensis.

PubMed

Prakash, Om; Nimonkar, Yogesh; Chavadar, Mahesh S; Bharti, Nidhi; Pawar, Shrikant; Sharma, Ashutosh; Shouche, Yogesh S

2017-06-01

An endophytic species of Micrococcus was isolated from Aloe vera leaf (syn. Aloe barbadensis ) and screened for protease production with five other species of Micrococcus . Data indicated that endophytic Micrococcus aloeverae AE-6 MCC 2184 T and Micrococcus yunnanensis DSM 21948 T showed efficient protease production potential and secreted active protease at high salt (10%), temperature (40 °C) and in wide range of pH 8-10. Unlike M . yunnanensis DSM 21948 T , protease production by M . aloeverae AE-6 MCC 2184 T was stringently controlled by pH. Protease induction study using different group of peptides, peptide carbohydrates and peptide macronutrient combinations showed variable response with both the organisms. Result indicated that the amount of protease was not directly related to cell biomass but it depends on nature of inducible peptides. In this study we also developed a modified agar-well assay for semi-quantitative data from large number of replicates.

Transformation of nitrogen contained in alfalfa silage, corn silage, corn grain and soybean meal into milk, manure and recycled back to corn

USDA-ARS?s Scientific Manuscript database

To better understand the transformative nature of feed nitrogen (N) on confinement dairy farms (cows fed stored feed in barns), a series of cow, laboratory, and field experiments was undertaken to quantify the relative amounts of N contained in individual ration components that are secreted in milk,...

Use of krypton laser stimulation in the treatment of dry eye syndrome

NASA Astrophysics Data System (ADS)

Kecik, Tadeusz; Switka-Wieclawska, Iwona; Ciszewska, Joanna; Portacha, Lidia

1991-08-01

We''d like to present the use of krypton laser stimulation in the treatment of dry eye syndrom. 10 patients with dry eye syndrom were treated with irradiation of the lacrimal gland. Schirmer test and break up time were performed before and after therapy. After 10 days of treatment we observed higher value of secreted tear amount.

Isolation and Identification of Proteins Secreted by Cells Cultured within Synthetic Hydrogel-Based Matrices

PubMed Central

2018-01-01

Cells interact with and remodel their microenvironment, degrading large extracellular matrix (ECM) proteins (e.g., fibronectin, collagens) and secreting new ECM proteins and small soluble factors (e.g., growth factors, cytokines). Synthetic mimics of the ECM have been developed as controlled cell culture platforms for use in both fundamental and applied studies. However, how cells broadly remodel these initially well-defined matrices remains poorly understood and difficult to probe. In this work, we have established methods for widely examining both large and small proteins that are secreted by cells within synthetic matrices. Specifically, human mesenchymal stem cells (hMSCs), a model primary cell type, were cultured within well-defined poly(ethylene glycol) (PEG)-peptide hydrogels, and these cell-matrix constructs were decellularized and degraded for subsequent isolation and analysis of deposited proteins. Shotgun proteomics using liquid chromatography and mass spectrometry identified a variety of proteins, including the large ECM proteins fibronectin and collagen VI. Immunostaining and confocal imaging confirmed these results and provided visualization of protein organization within the synthetic matrices. Additionally, culture medium was collected from the encapsulated hMSCs, and a Luminex assay was performed to identify secreted soluble factors, including vascular endothelial growth factor (VEGF), endothelial growth factor (EGF), basic fibroblast growth factor (FGF-2), interleukin 8 (IL-8), and tumor necrosis factor alpha (TNF-α). Together, these methods provide a unique approach for studying dynamic reciprocity between cells and synthetic microenvironments and have the potential to provide new biological insights into cell responses during three-dimensional (3D) controlled cell culture. PMID:29552635

Isolation and Identification of Proteins Secreted by Cells Cultured within Synthetic Hydrogel-Based Matrices.

PubMed

Sawicki, Lisa A; Choe, Leila H; Wiley, Katherine L; Lee, Kelvin H; Kloxin, April M

2018-03-12

Cells interact with and remodel their microenvironment, degrading large extracellular matrix (ECM) proteins (e.g., fibronectin, collagens) and secreting new ECM proteins and small soluble factors (e.g., growth factors, cytokines). Synthetic mimics of the ECM have been developed as controlled cell culture platforms for use in both fundamental and applied studies. However, how cells broadly remodel these initially well-defined matrices remains poorly understood and difficult to probe. In this work, we have established methods for widely examining both large and small proteins that are secreted by cells within synthetic matrices. Specifically, human mesenchymal stem cells (hMSCs), a model primary cell type, were cultured within well-defined poly(ethylene glycol) (PEG)-peptide hydrogels, and these cell-matrix constructs were decellularized and degraded for subsequent isolation and analysis of deposited proteins. Shotgun proteomics using liquid chromatography and mass spectrometry identified a variety of proteins, including the large ECM proteins fibronectin and collagen VI. Immunostaining and confocal imaging confirmed these results and provided visualization of protein organization within the synthetic matrices. Additionally, culture medium was collected from the encapsulated hMSCs, and a Luminex assay was performed to identify secreted soluble factors, including vascular endothelial growth factor (VEGF), endothelial growth factor (EGF), basic fibroblast growth factor (FGF-2), interleukin 8 (IL-8), and tumor necrosis factor alpha (TNF-α). Together, these methods provide a unique approach for studying dynamic reciprocity between cells and synthetic microenvironments and have the potential to provide new biological insights into cell responses during three-dimensional (3D) controlled cell culture.

[Participation of parasympathetic part of nervous system in realization of bioflavonoids action on gastric secretion in rats].

PubMed

Vovkun, T V; Yanchuk, P I; Shtanova, L Y; Veselskyy, S P; Shalamay, A S

2015-01-01

In this study we investigated the effects of corvitin--modified form of flavonoid quercetin on the stomach secretory function and physiological mechanisms involved in the maintenance of such effects in rat's pylorus-ligated model. In animals which corvitin was injected at a dose of 5 mg/kg, regardless of the route of administration--in the stomach or duodenum, did not observe any changes in the volume of gastric juice or general production of hydrochloric acid, compared with the control data. Dose of 40 mg/kg caused an increase in the volume of gastric juice and hydrochloric acid output as when administered in the stomach and in the duodenum. We also found that after the application of a large dose of corvitin (intragastrically) in the blood of experimental animals showed reduction in glucose levels, which was not detected when using the drug in a dose of 5 mg/kg. Nonspecific antagonist of M-cholinergic receptors--atropine almost completely blocked the enhancement of gastric secretion, which was caused by the introduction into the stomach of corvitin in large dose. From the present data, it is reasonable to conclude that intragastric administration of a large dose of corvitin to pylorus-ligated rats induces hypoglycemic reaction of blood, which may causes an increase in vagus nerve activity with subsequent stimulation of gastric secretion. The increase in gastric juice volume and gastric acid output induced by corvitin was completely inhibited by atropine. These results suggested that the increase in gastric secretion induced by intragastrically administered corvitin could be mediated by the parasympathetic nervous system.

Phylogenetic and functional signals in gymnosperm ovular secretions.

PubMed

Nepi, Massimo; Little, Stefan; Guarnieri, Massimo; Nocentini, Daniele; Prior, Natalie; Gill, Julia; Barry Tomlinson, P; Ickert-Bond, Stefanie M; Pirone, Cary; Pacini, Ettore; von Aderkas, Patrick

2017-11-28

Gymnosperms are either wind-pollinated (anemophilous) or both wind- and insect-pollinated (ambophilous). Regardless of pollination mode, ovular secretions play a key role in pollen capture, germination and growth; they are likely also involved in pollinator reward. Little is known about the broad-scale diversity of ovular secretions across gymnosperms, and how these may relate to various reproductive functions. This study analyses the sugar and amino acid profiles of ovular secretions across a range of ambophilous (cycads and Gnetales) and anemophilous gymnosperms (conifers) to place them in an evolutionary context of their possible functions during reproduction. Ovular secretions from 13 species representing all five main lineages of extant gymnosperms were sampled. High-performance liquid chromatography techniques were used to measure sugar and amino acid content. Multivariate statistics were applied to assess whether there are significant differences in the chemical profiles of anemophilous and ambophilous species. Data were compared with published chemical profiles of angiosperm nectar. Chemical profiles were placed in the context of phylogenetic relationships. Total sugar concentrations were significantly higher in ovular secretions of ambophilous species than wind-pollinated taxa such as Pinaceae and Cupressophyta. Ambophilous species had lower amounts of total amino acids, and a higher proportion of non-protein amino acids compared with anemophilous lineages, and were also comparable to angiosperm nectar. Results suggest that early gymnosperms likely had ovular secretion profiles that were a mosaic of those associated with modern anemophilous and ambophilous species. Ginkgo, thought to be anemophilous, had a profile typical of ambophilous taxa, suggesting that insect pollination either exists in Gingko, but is undocumented, or that its ancestral populations were insect-pollinated. Chemical profiles of ovular secretions of ambophilous gymnosperms show a clear signal of pollinator-driven selection, including higher levels of carbohydrates than anemophilous taxa, lower levels of amino acids, and the presence of specific amino acids, such as β-alanine, that are known to influence insect feeding behaviour and physiology. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please email: journals.permissions@oup.com

Neural Regulation of Lacrimal Gland Secretory Processes: Relevance in Dry Eye Diseases

PubMed Central

Dartt, Darlene A.

2013-01-01

The lacrimal gland is the major contributor to the aqueous layer of the tear film which consists of water, electrolytes and proteins. The amount and composition of this layer is critical for the health, maintenance, and protection of the cells of the cornea and conjunctiva (the ocular surface). Small changes in the concentration of tear electrolytes have been correlated with dry eye syndrome. While the mechanisms of secretion of water, electrolytes and proteins from the lacrimal gland differ, all three are under tight neural control. This allows for a rapid response to meet the needs of the cells of the ocular surface in response to environmental conditions. The neural response consists of the activation of the afferent sensory nerves in the cornea and conjunctiva to stimulate efferent parasympathetic and sympathetic nerves that innervate the lacrimal gland. Neurotransmitters are released from the stimulated parasympathetic and sympathetic nerves that cause secretion of water, electrolytes, and proteins from the lacrimal gland and onto the ocular surface. This review focuses on the neural regulation of lacrimal gland secretion under normal and dry eye conditions. PMID:19376264

Selective suppression of cytokine secretion in whole blood cell cultures of patients with colorectal cancer.

PubMed Central

Lahm, H.; Schindel, M.; Frikart, L.; Cerottini, J. P.; Yilmaz, A.; Givel, J. C.; Fischer, J. R.

1998-01-01

We have investigated the secretion of interferon alpha (IFN-alpha), IFN-gamma, interleukin-1alpha (IL-1alpha), IL-1beta, IL-2 and tumour necrosis factor alpha (TNF-alpha) in whole blood cell cultures (WBCCs) of colorectal cancer patients upon mitogen stimulation. Whereas the values for IL-1beta and TNF-alpha remained virtually unchanged in comparison with healthy control subjects, WBCCs of colorectal cancer patients secreted significantly lower amounts of IFN-alpha (P < 0.005), IFN-gamma (P < 0.0001), IL-1alpha (P < 0.0001) and IL-2 (P < 0.05). This reduction correlated with the progression of the disease. The total leucocyte and monocyte population were almost identical in both groups. In contrast, a dramatic depletion of lymphocytes was observed in colorectal cancer patients, which affected both lymphocyte counts (P < 0.0005) and their distribution (P < 0.0001). Our results suggest a selective suppression of cytokines in colorectal cancer patients that is related to tumour burden. Several mechanisms might account for this phenomenon, one of which might be lymphocyte depletion. PMID:9792144

[Cephalic phase of insulin secretion and the variety of the food in rat feed].

PubMed

Louis-Sylvestre, J; Le Magnen, J

1983-01-01

Immunologically reactive insulin levels were determined in freely-moving normal rats offered three different test-meals. In test I, they were offered their normal diet for 4.5 min. In test II, they first ate the same diet for the same amount of time, then a cookie for 6 min, and finally they had free access to lard. In test III, the normal diet was followed by a synthetic sweetener and then by vaseline. It was shown that in a varied meal (tests II and III), the ingestion of each new food was immediately followed by a peak of insulin secretion superimposed on normal postprandial hyperinsulinemia. This resulted in an overall increase in insulinemia over the 15-min period measured. It is well known that in a varied meal more food is consumed. Thus, it may be that when a varied meal is offered, final satiety is postponed. This could be due to sensorially-triggered peaks of insulin secretion which would explain why the "cafeteria diet" induces hyperphagia and obesity.

Secretome Identifies Tenascin-X as a Potent Marker of Ovarian Cancer

PubMed Central

Kramer, Marianne; Pierredon, Sandra; Ribaux, Pascale; Tille, Jean-Christophe; Cohen, Marie

2015-01-01

CA-125 has been a valuable marker for the follow-up of ovarian cancer patients but it is not sensitive enough to be used as diagnostic marker. We had already used secretomic methods to identify proteins differentially secreted by serous ovarian cancer cells compared to healthy ovarian cells. Here, we evaluated the secretion of these proteins by ovarian cancer cells during the follow-up of one patient. Proteins that correlated with CA-125 levels were screened using serum samples from ovarian cancer patients as well as benign and healthy controls. Tenascin-X secretion was shown to correlate with CA-125 value in the initial case study. The immunohistochemical detection of increased amount of tenascin-X in ovarian cancer tissues compared to healthy tissues confirms the potent interest in tenascin-X as marker. We then quantified the tenascin-X level in serum of patients and identified tenascin-X as potent marker for ovarian cancer, showing that secretomic analysis is suitable for the identification of protein biomarkers when combined with protein immunoassay. Using this method, we determined tenascin-X as a new potent marker for serous ovarian cancer. PMID:26090390

Differential effect of combined lipase deficiency (cld/cld) on human hepatic lipase and lipoprotein lipase secretion.

PubMed

Boedeker, J C; Doolittle, M H; White, A L

2001-11-01

Combined lipase deficiency (cld) is a recessively inherited disorder in mice associated with a deficiency of LPL and hepatic lipase (HL) activity. LPL is synthesized in cld tissues but is retained in the endoplasmic reticulum (ER), whereas mouse HL (mHL) is secreted but inactive. In this study we investigated the effect of cld on the secretion of human HL (hHL) protein mass and activity. Differentiated liver cell lines were derived from cld mice and their normal heterozygous (het) littermates by transformation of hepatocytes with SV40 large T antigen. After transient transfection with lipase expression constructs, secretion of hLPL activity from cld cells was only 12% of that from het cells. In contrast, the rate of secretion of hHL activity and protein mass per unit of expressed hHL mRNA was identical for the two cell lines. An intermediate effect was observed for mHL, with a 46% reduction in secretion of activity from cld cells. The ER glucosidase inhibitor, castanospermine, decreased secretion of both hLPL and hHL from het cells by approximately 70%, but by only approximately 45% from cld cells. This is consistent with data suggesting that cld may result from a reduced concentration of the ER chaperone calnexin. In conclusion, our results demonstrate a differential effect of cld on hLPL, mHL, and hHL secretion, suggesting differential requirements for activation and exit of the enzymes from the ER.

Gliding Motility and Por Secretion System Genes Are Widespread among Members of the Phylum Bacteroidetes

PubMed Central

Zhu, Yongtao

2013-01-01

The phylum Bacteroidetes is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium Flavobacterium johnsoniae and the nonmotile oral pathogen Porphyromonas gingivalis. The components of the PorSS are not similar in sequence to those of other well-studied bacterial secretion systems. The F. johnsoniae PorSS genes are a subset of the gliding motility genes, suggesting a role for the secretion system in motility. The F. johnsoniae PorSS is needed for assembly of the gliding motility apparatus and for secretion of a chitinase, and the P. gingivalis PorSS is involved in secretion of gingipain protease virulence factors. Comparative analysis of 37 genomes of members of the phylum Bacteroidetes revealed the widespread occurrence of gliding motility genes and PorSS genes. Genes associated with other bacterial protein secretion systems were less common. The results suggest that gliding motility is more common than previously reported. Microscopic observations confirmed that organisms previously described as nonmotile, including Croceibacter atlanticus, “Gramella forsetii,” Paludibacter propionicigenes, Riemerella anatipestifer, and Robiginitalea biformata, exhibit gliding motility. Three genes (gldA, gldF, and gldG) that encode an apparent ATP-binding cassette transporter required for F. johnsoniae gliding were absent from two related gliding bacteria, suggesting that the transporter may not be central to gliding motility. PMID:23123910

The house economist and the eating paradox.

PubMed

Woods, Stephen C

2002-04-01

An important observation of the experiments of George Collier is that animals normally prefer to maintain their body weight by eating a large number of small meals each day. However, as the effort to obtain access to food increases, the animals adapt by changing to a schedule of eating a small number of large meals each day. A strong implication of this is that there is a hidden cost to eating large meals, and this is the basis of the eating paradox that states that although food is a necessary commodity, the act of ingesting it poses certain metabolic problems for animals. Experiments on cephalic insulin secretion, conditioned insulin secretion and meal feeding are discussed to make the point that the economy demonstrated by rats in Collier's paradigm is dictated in part by predictions of the eating paradox. Copyright 2002 Elsevier Science Ltd.

Common and Distinct Capsid and Surface Protein Requirements for Secretion of Complete and Genome-free Hepatitis B Virions.

PubMed

Ning, Xiaojun; Luckenbaugh, Laurie; Liu, Kuancheng; Bruss, Volker; Sureau, Camille; Hu, Jianming

2018-05-09

During the morphogenesis of hepatitis B virus (HBV), an enveloped virus, two types of virions are secreted: (1) a minor population of complete virions containing a mature nucleocapsid with the characteristic, partially double-stranded, relaxed circular DNA genome and (2) a major population containing an empty capsid with no DNA or RNA (empty virions). Secretion of both types of virions requires interactions between the HBV capsid or core protein (HBc) and the viral surface or envelope proteins. We have studied the requirements from both HBc and envelope proteins for empty virion secretion, in comparison with those for secretion of complete virions. Substitutions within the N-terminal domain of HBc that block secretion of DNA-containing virions reduced but did not prevent secretion of empty virions. The HBc C-terminal domain was not essential for empty virion secretion. Among the three viral envelope proteins, the smallest, S, alone was sufficient for empty virion secretion at a basal level. The largest protein, L, essential for complete virion secretion, was not required for, but could stimulate empty virion secretion. Also, substitutions in L that eliminate secretion of complete virions reduced but did not eliminate empty virion secretion. S mutations that block secretion of the hepatitis D virus (HDV), an HBV satellite, did not block secretion of either empty or complete HBV virions. Together, these results indicate that both common and distinct signals on empty capsids vs. mature nucleocapsids interact with the S and L proteins during the formation of complete vs. empty virions. IMPORTANCE Hepatitis B virus (HBV) is a major cause of severe liver diseases including cirrhosis and cancer. In addition to the complete infectious virion particle, which contains an outer envelope layer and an interior capsid that, in turn, encloses a DNA genome, HBV infected cells also secrete non-infectious, incomplete viral particles in large excess over the complete virions. In particular, the empty (or genome-free) virion share with the complete virion the outer envelope and interior capsid but contain no genome. We have carried out a comparative study on the capsid and envelope requirements for the secretion of these two types of virion particles and uncovered both shared and distinct determinants on the capsid and envelope for their secretion. These results provide new information on HBV morphogenesis, and have implications for efforts to develop empty HBV virions as a novel biomarker and a new generation of HBV vaccine. Copyright © 2018 American Society for Microbiology.

Preattachment Embryos of Domestic Animals: Insights into Development and Paracrine Secretions.

PubMed

Sandra, Olivier; Charpigny, Gilles; Galio, Laurent; Hue, Isabelle

2017-02-08

In mammalian species, endometrial receptivity is driven by maternal factors independently of embryo signals. When pregnancy initiates, paracrine secretions of the preattachment embryo are essential both for maternal recognition and endometrium preparation for implantation and for coordinating development of embryonic and extraembryonic tissues of the conceptus. This review mainly focuses on domestic large animal species. We first illustrate the major steps of preattachment embryo development, including elongation in bovine, ovine, porcine, and equine species. We next highlight conceptus secretions that are involved in the communication between extraembryonic and embryonic tissues, as well as between the conceptus and the endometrium. Finally, we introduce experimental data demonstrating the intimate connection between conceptus secretions and endometrial activity and how adverse events perturbing this interplay may affect the progression of implantation that will subsequently impact pregnancy outcome, postnatal health, and expression of production traits in livestock offspring.

Interaction of corneal nociceptive stimulation and lacrimal secretion.

PubMed

Situ, Ping; Simpson, Trefford L

2010-11-01

To investigate the interaction between corneal stimuli at different positions and tear secretion and to establish relationships between nociceptive stimuli detection thresholds and stimulated tearing. Using a computerized Belmonte-esthesiometer, mechanical and chemical stimuli, from 0% to 200% of the threshold in 50% steps, were delivered (in random order) to the central and peripheral (approximately 2-mm inside the limbus) cornea during four separate sessions to 15 subjects. Immediately after each stimulus, tear meniscus height (TMH) was measured using optical coherence tomography to quantify the amount of lacrimal secretion, and subjects reported whether they felt tears starting to accumulate in their eyes. Thresholds (50% detection) for detection of tearing were estimated. TMH increased with increasing stimulus intensity (P < 0.05), and the overall increase was higher with central stimulation than with peripheral stimulation (P < 0.05). The changes in TMH with threshold-scaled stimulus intensity depended on test location (P < 0.05) and stimulus modality (P < 0.05). The maximum intensity of mechanical stimulation of the central cornea induced the greatest TMH (all P < 0.05). For chemical stimulation, the stimulus intensity required to induce detectable tearing was higher than that required to detect a stimulus and higher in the periphery than at the center (all P < 0.05). Noxious mechanical and chemical stimuli evoked measurable tear secretion, with central corneal mechanical stimulation evoking the strongest lacrimation reflex. Central mechanical corneal stimulation is the most effective stimulus-position pairing and appears to be the major sensory driving force for reflex tear secretion by the lacrimal functional unit.

Mesosecrin: a secreted glycoprotein produced in abundance by human mesothelial, endothelial, and kidney epithelial cells in culture

PubMed Central

1987-01-01

Human mesothelial cells, endothelial cells, and type II kidney epithelial cells growing in culture devote approximately 3% of their total protein synthesis to the production of an Mr approximately 46-kD, pI 7.1, secreted glycoprotein (designated Sp46). Fibroblasts make about 1/10th as much Sp46 as these cell types, and their synthesis is dependent upon hydrocortisone. Keratinocytes, urothelial cells, conjunctival epithelial cells, and mammary epithelial cells do not make detectable amounts of Sp46. Mesothelial cells secrete Sp46 onto the substratum, and from there it is subsequently released into the medium. Immunofluorescence analysis using specific antisera discloses that Sp46 is deposited beneath cells as a fine coating on the substratum. In sparse cultures, Sp46 is detected in trails behind motile cells. In contrast, secreted fibronectin coalesces into fibers, most of which remain in contact with and on top of the cells; thus Sp46 does not preferentially bind to fibronectin. About 6 kD of the mass of human Sp46 is N-linked oligosaccharide, which is terminally sialated before secretion. Sp46 has a low glycine content, indicating that it is not a collagenlike protein. Its NH2-terminal sequence over the first 40 amino acids does not resemble any protein for which sequence information is available. Sp46 appears to be a novel extracellular glycoprotein, high- level constitutive expression of which is restricted to mesoderm- derived epithelial and endothelial cells. We therefore propose for it the name "mesosecrin." PMID:3543023

Fluoride induces endoplasmic reticulum stress and inhibits protein synthesis and secretion.

PubMed

Sharma, Ramaswamy; Tsuchiya, Masahiro; Bartlett, John D

2008-09-01

Exposure to excessive amounts of fluoride (F(-)) causes dental fluorosis in susceptible individuals; however, the mechanism of F(-)-induced toxicity is unclear. Previously, we have shown that high-dose F(-) activates the unfolded protein response (UPR) in ameloblasts that are responsible for dental enamel formation. The UPR is a signaling pathway responsible for either alleviating endoplasmic reticulum (ER) stress or for inducing apoptosis of the stressed cells. In this study we determined if low-dose F(-) causes ER stress and activates the UPR, and we also determined whether F(-) interferes with the secretion of proteins from the ER. We stably transfected the ameloblast-derived LS8 cell line with secreted alkaline phosphatase (SEAP) and determined activity and localization of SEAP and F(-)-mediated induction of UPR proteins. Also, incisors from mice given drinking water containing various concentrations of F(-) were examined for eucaryotic initiation factor-2, subunit alpha (eIF2alpha) phosphorylation. We found that F(-) decreases the extracellular secretion of SEAP in a linear, dose-dependent manner. We also found a corresponding increase in the intracellular accumulation of SEAP after exposure to F(-). These changes are associated with the induction of UPR proteins such as the molecular chaperone BiP and phosphorylation of the UPR sensor PKR-like ER kinase, and its substrate, eIF2alpha. Importantly, F(-)-induced phosphorylation of eIF2alphawas confirmed in vivo. These data suggest that F(-) initiates an ER stress response in ameloblasts that interferes with protein synthesis and secretion. Consequently, ameloblast function during enamel development may be impaired, and this may culminate in dental fluorosis.

The N-terminal neurotensin fragment, NT1-11, inhibits cortisol secretion by human adrenocortical cells.

PubMed

Sicard, Flavie; Contesse, Vincent; Lefebvre, Hervé; Ait-Ali, Djida; Gras, Marjorie; Cartier, Dorthe; Decker, Annick; Chartrel, Nicolas; Anouar, Youssef; Vaudry, Hubert; Delarue, Catherine

2006-08-01

Neurotensin (NT) modulates corticosteroid secretion from the mammalian adrenal gland. The objective of this study was to investigate the possible involvement of NT in the control of cortisol secretion in the human adrenal gland. In vitro studies were conducted on cultured human adrenocortical cells. This study was conducted in a university research laboratory. Adrenal explants from patients undergoing expanded nephrectomy for kidney cancer were studied. Cortisol secretion from cultured adrenocortical cells was measured. NT1-11, the N-terminal fragment of NT, dose-dependently inhibited basal and ACTH-stimulated cortisol production by human adrenocortical cells in primary culture. In contrast, NT had no influence on cortisol output at concentrations up to 10(-6) m. HPLC and RT-PCR analyses failed to detect any significant amounts of NT and NT mRNA, respectively, in adrenal extracts. Molecular and pharmacological studies were performed to determine the type of NT receptor involved in the corticostatic effect of NT1-11. RT-PCR analysis revealed the expression of NT receptor type (NTR) 3 mRNA but not NTR1 and NTR2 mRNAs in the human adrenal tissue. However, the pharmacological profile of the adrenal NT1-11 receptor was different from that of NTR3, indicating that this receptor type is not involved in the action of NT1-11 on corticosteroidogenesis. Our results indicate that NT1-11 may act as an endocrine factor to inhibit cortisol secretion through activation of a receptor distinct from the classical NTR1, NTR2, and NTR3.

Rotating wall vessel exposure alters protein secretion and global gene expression in Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Rosado, Helena; O'Neill, Alex J.; Blake, Katy L.; Walther, Meik; Long, Paul F.; Hinds, Jason; Taylor, Peter W.

2012-04-01

Staphylococcus aureus is routinely recovered from air and surface samples taken aboard the International Space Station (ISS) and poses a health threat to crew. As bacteria respond to the low shear forces engendered by continuous rotation conditions in a Rotating Wall Vessel (RWV) and the reduced gravitational field of near-Earth flight by altering gene expression, we examined the effect of low-shear RWV growth on protein secretion and gene expression by three S. aureus isolates. When cultured under 1 g, the total amount of protein secreted by these strains varied up to fourfold; under continuous rotation conditions, protein secretion by all three strains was significantly reduced. Concentrations of individual proteins were differentially reduced and no evidence was found for increased lysis. These data suggest that growth under continuous rotation conditions reduces synthesis or secretion of proteins. A limited number of changes in gene expression under continuous rotation conditions were noted: in all isolates vraX, a gene encoding a polypeptide associated with cell wall stress, was down-regulated. A vraX deletion mutant of S. aureus SH1000 was constructed: no differences were found between SH1000 and ΔvraX with respect to colony phenotype, viability, protein export, antibiotic susceptibility, vancomycin kill kinetics, susceptibility to cold or heat and gene modulation. An ab initio protein-ligand docking simulation suggests a major binding site for β-lactam drugs such as imipenem. If such changes to the bacterial phenotype occur during spaceflight, they will compromise the capacity of staphylococci to cause systemic infection and to circumvent antibacterial chemotherapy.

Gene expression profiling reveals candidate genes related to residual feed intake in duodenum of laying ducks.

PubMed

Zeng, T; Huang, L; Ren, J; Chen, L; Tian, Y; Huang, Y; Zhang, H; Du, J; Lu, L

2017-12-01

Feed represents two-thirds of the total costs of poultry production, especially in developing countries. Improvement in feed efficiency would reduce the amount of feed required for production (growth or laying), the production cost, and the amount of nitrogenous waste. The most commonly used measures for feed efficiency are feed conversion ratio (FCR) and residual feed intake (RFI). As a more suitable indicator assessing feed efficiency, RFI is defined as the difference between observed and expected feed intake based on maintenance and growth or laying. However, the genetic and biological mechanisms regulating RFI are largely unknown. Identifying molecular mechanisms explaining divergence in RFI in laying ducks would lead to the development of early detection methods for the selection of more efficient breeding poultry. The objective of this study was to identify duodenum genes and pathways through transcriptional profiling in 2 extreme RFI phenotypes (HRFI and LRFI) of the duck population. Phenotypic aspects of feed efficiency showed that RFI was strongly positive with FCR and feed intake (FI). Transcriptomic analysis identified 35 differentially expressed genes between LRFI and HRFI ducks. These genes play an important role in metabolism, digestibility, secretion, and innate immunity including (), (), (), β (), and (). These results improve our knowledge of the biological basis underlying RFI, which would be useful for further investigations of key candidate genes for RFI and for the development of biomarkers.

Differential effect of inhibitors of oligosaccharide processing on the secretion of thyrotropin from dispersed rodent pituitary cells.

PubMed

Stannard, B S; Gesundheit, N; Thotakura, N R; Gyves, P W; Ronin, C; Weintraub, B D

1989-12-15

We examined the effect of various inhibitors of oligosaccharide processing on the content and secretion of newly synthesized thyroid-stimulating hormone (TSH) from dispersed hypothyroid rodent pituitary cells. 1-deoxynojirimycin and N-methyl-1-deoxynojirimycin, both inhibitors of glucosidases I and II, decreased intracellular TSH (to 60-76% of control) and secreted TSH (to 60-63% of control) after a 1-hour incubation (pulse) with [35S]methionine and an 8-hour incubation (chase) in isotope-free media. In contrast, deoxymannojirimycin and swainsonine, inhibitors of mannosidase I and II, respectively, increased both intracellular TSH (to 267-309% of control) and secreted TSH (to 192% of control) at 8 hours. TSH oligosaccharides synthesized in the presence of these glucosidase and mannosidase inhibitors were largely sensitive to endo-beta-N-acetylglucosaminidase H (endo H), confirming inhibition of processing. Despite differences in oligosaccharide structure, the in vitro bioactivities of these secreted TSH isoforms were nearly identical. These data confirm and extend previous work performed with 1-deoxynojirimycin suggesting that glucosylated high mannose forms of TSH are more susceptible to intracellular degradation. The novel finding that deoxymannojirimycin and swainsonine increase secreted and total TSH above control levels suggests that non-glucosylated high mannose forms as well as hybrid-type oligosaccharides may facilitate secretion and direct TSH away from a natural degradation pathway.

Efficient Secretion of Recombinant Proteins from Rice Suspension-Cultured Cells Modulated by the Choice of Signal Peptide.

PubMed

Huang, Li-Fen; Tan, Chia-Chun; Yeh, Ju-Fang; Liu, Hsin-Yi; Liu, Yu-Kuo; Ho, Shin-Lon; Lu, Chung-An

2015-01-01

Plant-based expression systems have emerged as a competitive platform in the large-scale production of recombinant proteins. By adding a signal peptide, αAmy3sp, the desired recombinant proteins can be secreted outside transgenic rice cells, making them easy to harvest. In this work, to improve the secretion efficiency of recombinant proteins in rice expression systems, various signal peptides including αAmy3sp, CIN1sp, and 33KDsp have been fused to the N-terminus of green fluorescent protein (GFP) and introduced into rice cells to explore the efficiency of secretion of foreign proteins. 33KDsp had better efficiency than αAmy3sp and CIN1sp for the secretion of GFP from calli and suspension-cultured cells. 33KDsp was further applied for the secretion of mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) from transgenic rice suspension-cultured cells; approximately 76%-92% of total rice-derived mGM-CSF (rmGM-CSF) was detected in the culture medium. The rmGM-CSF was bioactive and could stimulate the proliferation of a murine myeloblastic leukemia cell line, NSF-60. The extracellular yield of rmGM-CSF reached 31.7 mg/L. Our study indicates that 33KDsp is better at promoting the secretion of recombinant proteins in rice suspension-cultured cell systems than the commonly used αAmy3sp.

Isolation and Characterization of Escherichia coli tolC Mutants Defective in Secreting Enzymatically Active Alpha-Hemolysin

PubMed Central

Vakharia, Hema; German, Greg J.; Misra, Rajeev

2001-01-01

This study describes the isolation and characterization of a unique class of TolC mutants that, under steady-state growth conditions, secreted normal levels of largely inactive alpha-hemolysin. Unlike the reduced activity in the culture supernatants, the cell-associated hemolytic activity in these mutants was identical to that in the parental strain, thus reflecting a normal intracellular toxin activation event. Treatment of the secreted toxin with guanidine hydrochloride significantly restored cytolytic activity, suggesting that the diminished activity may have been due to the aggregation or misfolding of the toxin molecules. Consistent with this notion, sedimentation and filtration analyses showed that alpha-hemolysin secreted from the mutant strain has a mass greater than that secreted from the parental strain. Experiments designed to monitor the time course of alpha-hemolysin release showed delayed appearance of toxin in the culture supernatant of the mutant strain, thus indicating a possible defect in alpha-hemolysin translocation or release. Eight different TolC substitutions displaying this toxin secretion defect were scattered throughout the protein, of which six localized in the periplasmically exposed α-helical domain, while the remaining two mapped within the outer membrane-embedded β-barrel domain of TolC. A plausible model for the secretion of inactive alpha-hemolysin in these TolC mutants is discussed in the context of the recently determined three-dimensional structure of TolC. PMID:11698380

Abolition of Ca2+-mediated intestinal anion secretion and increased stool dehydration in mice lacking the intermediate conductance Ca2+-dependent K+ channel Kcnn4

PubMed Central

Flores, Carlos A; Melvin, James E; Figueroa, Carlos D; Sepúlveda, Francisco V

2007-01-01

Intestinal fluid secretion is driven by apical membrane, cystic fibrosis transmembrane conductance regulator (CFTR)-mediated efflux of Cl– that is concentrated in cells by basolateral Na+−K+−2Cl– cotransporters (NKCC1). An absolute requirement for Cl– efflux is the parallel activation of K+ channels which maintain a membrane potential that sustains apical anion secretion. Both cAMP and Ca2+ are intracellular signals for intestinal Cl– secretion. The K+ channel involved in cAMP-dependent secretion has been identified as the KCNQ1–KCNE3 complex, but the identity of the K+ channel driving Ca2+-activated Cl– secretion is controversial. We have now used a Kcnn4 null mouse to show that the intermediate conductance IK1 K+ channel is necessary and sufficient to support Ca2+-dependent Cl– secretion in large and small intestine. Ussing chambers were used to monitor transepithelial potential, resistance and equivalent short-circuit current in colon and jejunum from control and Kcnn4 null mice. Na+, K+ and water content of stools was also measured. Distal colon and small intestinal epithelia from Kcnn4 null mice had normal cAMP-dependent Cl– secretory responses. In contrast, they completely lacked Cl– secretion in response to Ca2+-mobilizing agonists. Ca2+-activated electrogenic K+ secretion was increased in colon epithelium of mice deficient in the IK1 channel. Na+ and water content of stools was diminished in IK1-null animals. The use of Kcnn4 null mice has allowed us to demonstrate that IK1 K+ channels are solely responsible for driving intestinal Ca2+-activated Cl– secretion. The absence of this channel leads to a marked reduction in water content in the stools, probably as a consequence of decreased electrolyte and water secretion. PMID:17584847

Testosterone-secreting adrenal adenoma in a peripubertal girl

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamilaris, T.C.; DeBold, C.R.; Manolas, K.J.

1987-11-13

A 15-year-old girl who presented with primary amenorrhea and virilization had an adrenocortical adenoma that secreted predominantly testosterone. To the authors' knowledge, she is the first peripubertal and second youngest patient with a testosterone-secreting adrenal tumor described. Serum dehydroepiandrosterone sulfate and urinary 17-ketosteroid an 17-hydroxycorticosteroid levels were normal. A tumor was located by a computed tomographic (CT) scan and by uptake of 6-..beta..-(/sup 75/Se) selenomethylnorcholesterol. Microscopic examination of the tumor showed typical features of an adrenocortical adenoma with no histologic features characteristic of Leydig cells. Postoperatively, her hirsutism regressed, she rapidly went through puberty, and regular monthly menstruation started fourmore » months later. Finding the source of testosterone in a virilized patient can be difficult. Eleven of the 14 previously described patients with testosterone-secreting adrenal tumors initially underwent misdirected surgery on the ovaries. Review of these cases revealed that results of hormone stimulation and suppression tests are unreliable and that these tumors are usually large. Therefore, CT scanning of the adrenal glands is recommended in all patients suspected of having a testosterone-secreting tumor.« less

BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion.

PubMed

Kolarow, Richard; Kuhlmann, Christoph R W; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J; Lessmann, Volkmar

2014-01-01

BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling.

BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion

PubMed Central

Kolarow, Richard; Kuhlmann, Christoph R. W.; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J.; Lessmann, Volkmar

2014-01-01

BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling. PMID:25426021

Preprotein mature domains contain translocase targeting signals that are essential for secretion.

PubMed

Chatzi, Katerina E; Sardis, Marios Frantzeskos; Tsirigotaki, Alexandra; Koukaki, Marina; Šoštarić, Nikolina; Konijnenberg, Albert; Sobott, Frank; Kalodimos, Charalampos G; Karamanou, Spyridoula; Economou, Anastassios

2017-05-01

Secretory proteins are only temporary cytoplasmic residents. They are typically synthesized as pre proteins, carrying signal peptides N-terminally fused to their mature domains. In bacteria secretion largely occurs posttranslationally through the membrane-embedded SecA-SecYEG translocase. Upon crossing the plasma membrane, signal peptides are cleaved off and mature domains reach their destinations and fold. Targeting to the translocase is mediated by signal peptides. The role of mature domains in targeting and secretion is unclear. We now reveal that mature domains harbor their own independent targeting signals (mature domain targeting signals [MTSs]). These are multiple, degenerate, interchangeable, linear or 3D hydrophobic stretches that become available because of the unstructured states of targeting-competent preproteins. Their receptor site on the cytoplasmic face of the SecYEG-bound SecA is also of hydrophobic nature and is located adjacent to the signal peptide cleft. Both the preprotein MTSs and their receptor site on SecA are essential for protein secretion. Evidently, mature domains have their own previously unsuspected distinct roles in preprotein targeting and secretion. © 2017 Chatzi et al.

Preprotein mature domains contain translocase targeting signals that are essential for secretion

PubMed Central

Tsirigotaki, Alexandra; Koukaki, Marina; Šoštarić, Nikolina; Konijnenberg, Albert; Sobott, Frank; Kalodimos, Charalampos G.; Karamanou, Spyridoula

2017-01-01

Secretory proteins are only temporary cytoplasmic residents. They are typically synthesized as preproteins, carrying signal peptides N-terminally fused to their mature domains. In bacteria secretion largely occurs posttranslationally through the membrane-embedded SecA-SecYEG translocase. Upon crossing the plasma membrane, signal peptides are cleaved off and mature domains reach their destinations and fold. Targeting to the translocase is mediated by signal peptides. The role of mature domains in targeting and secretion is unclear. We now reveal that mature domains harbor their own independent targeting signals (mature domain targeting signals [MTSs]). These are multiple, degenerate, interchangeable, linear or 3D hydrophobic stretches that become available because of the unstructured states of targeting-competent preproteins. Their receptor site on the cytoplasmic face of the SecYEG-bound SecA is also of hydrophobic nature and is located adjacent to the signal peptide cleft. Both the preprotein MTSs and their receptor site on SecA are essential for protein secretion. Evidently, mature domains have their own previously unsuspected distinct roles in preprotein targeting and secretion. PMID:28404644

HIF-1 maintains a functional relationship between pancreatic cancer cells and stromal fibroblasts by upregulating expression and secretion of Sonic hedgehog

PubMed Central

Katagiri, Tomohiro; Kobayashi, Minoru; Yoshimura, Michio; Morinibu, Akiyo; Itasaka, Satoshi; Hiraoka, Masahiro; Harada, Hiroshi

2018-01-01

Hypoxic and stroma-rich microenvironments, characteristic features of pancreatic cancers, are strongly associated with a poor prognosis. However, whether and how hypoxia increases stromal compartments remain largely unknown. Here, we investigated the potential importance of a master regulator of the cellular adaptive response to hypoxia, hypoxia-inducible factor-1 (HIF-1), in the formation of stroma-rich microenvironments of pancreatic tumors. We found that pancreatic cancer cells secreted more Sonic hedgehog protein (SHH) under hypoxia by upregulating its expression and efficiency of secretion in a HIF-1-dependent manner. Recombinant SHH, which was confirmed to activate the hedgehog signaling pathway, accelerated the growth of fibroblasts in a dose-dependent manner. The SHH protein secreted from pancreatic cancer cells under hypoxic conditions promoted the growth of fibroblasts by stimulating their Sonic hedgehog signaling pathway. These results suggest that the increased secretion of SHH by HIF-1 is potentially responsible for the formation of detrimental and stroma-rich microenvironments in pancreatic cancers, therefore providing a rational basis to target it in cancer therapy. PMID:29535824

An Intracellular Peptidyl-Prolyl cis/trans Isomerase Is Required for Folding and Activity of the Staphylococcus aureus Secreted Virulence Factor Nuclease.

PubMed

Wiemels, Richard E; Cech, Stephanie M; Meyer, Nikki M; Burke, Caleb A; Weiss, Andy; Parks, Anastacia R; Shaw, Lindsey N; Carroll, Ronan K

2017-01-01

Staphylococcus aureus is an important human pathogen that relies on a large repertoire of secreted and cell wall-associated proteins for pathogenesis. Consequently, the ability of the organism to cause disease is absolutely dependent on its ability to synthesize and successfully secrete these proteins. In this study, we investigate the role of peptidyl-prolyl cis/trans isomerases (PPIases) on the activity of the S. aureus secreted virulence factor nuclease (Nuc). We identify a staphylococcal cyclophilin-type PPIase (PpiB) that is required for optimal activity of Nuc. Disruption of ppiB results in decreased nuclease activity in culture supernatants; however, the levels of Nuc protein are not altered, suggesting that the decrease in activity results from misfolding of Nuc in the absence of PpiB. We go on to demonstrate that PpiB exhibits PPIase activity in vitro, is localized to the bacterial cytosol, and directly interacts with Nuc in vitro to accelerate the rate of Nuc refolding. Finally, we demonstrate an additional role for PpiB in S. aureus hemolysis and demonstrate that the S. aureus parvulin-type PPIase PrsA also plays a role in the activity of secreted virulence factors. The deletion of prsA leads to a decrease in secreted protease and phospholipase activity, similar to that observed in other Gram-positive pathogens. Together, these results demonstrate, for the first time to our knowledge, that PPIases play an important role in the secretion of virulence factors in S. aureus IMPORTANCE: Staphylococcus aureus is a highly dangerous bacterial pathogen capable of causing a variety of infections throughout the human body. The ability of S. aureus to cause disease is largely due to an extensive repertoire of secreted and cell wall-associated proteins, including adhesins, toxins, exoenzymes, and superantigens. These virulence factors, once produced, are typically transported across the cell membrane by the secretory (Sec) system in a denatured state. Consequently, once outside the cell, they must refold into their active form. This step often requires the assistance of bacterial folding proteins, such as PPIases. In this work, we investigate the role of PPIases in S. aureus and uncover a cyclophilin-type enzyme that assists in the folding/refolding of staphylococcal nuclease. Copyright © 2016 American Society for Microbiology.

The effects of restraint on uptake of radioactive sulfate in the salivary and gastric secretions of rats with pyloric ligation

NASA Technical Reports Server (NTRS)

Chayvialle, J. A.; Lambert, R.; Ruet, D.

1980-01-01

The effects of restraint on the amount of nondialysable radioactive sulfate in the gastric wall and the gastric juice and saliva were investigated. It was found that restraint provokes a significant decrease in salivary radioactive sulfate. This, in turn, is responsible for the decrease of sulfate in the gastric contents observed under these conditions in rats with pyloric ligation. Esophageal ligation associated with this prevents passage of saliva and lowers the amount of radioactive sulfate in the gastric juice. Restraint causes then an increase in the amount of sulfate in the gastric juice, the value observed being very much lower than that of rats with a free esophagus. At the level of the gastric wall, the change observed during restraint does not reach a significant threshold.

Antifoam addition to shake flask cultures of recombinant Pichia pastoris increases yield

PubMed Central

2011-01-01

Background Pichia pastoris is a widely-used host for recombinant protein production. Initial screening for both suitable clones and optimum culture conditions is typically carried out in multi-well plates. This is followed by up-scaling either to shake-flasks or continuously stirred tank bioreactors. A particular problem in these formats is foaming, which is commonly prevented by the addition of chemical antifoaming agents. Intriguingly, antifoams are often added without prior consideration of their effect on the yeast cells, the protein product or the influence on downstream processes such as protein purification. In this study we characterised, for the first time, the effects of five commonly-used antifoaming agents on the total amount of recombinant green fluorescent protein (GFP) secreted from shake-flask cultures of this industrially-relevant yeast. Results Addition of defined concentrations of Antifoam A (Sigma), Antifoam C (Sigma), J673A (Struktol), P2000 (Fluka) or SB2121 (Struktol) to shake-flask cultures of P. pastoris increased the total amount of recombinant GFP in the culture medium (the total yield) and in the case of P2000, SB2121 and J673A almost doubled it. When normalized to the culture density, the GFP specific yield (μg OD595-1) was only increased for Antifoam A, Antifoam C and J673A. Whilst none of the antifoams affected the growth rate of the cells, addition of P2000 or SB2121 was found to increase culture density. There was no correlation between total yield, specific yield or specific growth rate and the volumetric oxygen mass transfer coefficient (kLa) in the presence of antifoam. Moreover, the antifoams did not affect the dissolved oxygen concentration of the cultures. A comparison of the amount of GFP retained in the cell by flow cytometry with that in the culture medium by fluorimetry suggested that addition of Antifoam A, Antifoam C or J673A increased the specific yield of GFP by increasing the proportion secreted into the medium. Conclusions We show that addition of a range of antifoaming agents to shake flask cultures of P. pastoris increases the total yield of the recombinant protein being produced. This is not only a simple method to increase the amount of protein in the culture, but our study also provides insight into how antifoams interact with microbial cell factories. Two mechanisms are apparent: one group of antifoams (Antifoam A, Antifoam C and J673A) increases the specific yield of GFP by increasing the total amount of protein produced and secreted per cell, whilst the second (P2000 or SB2121) increases the total yield by increasing the density of the culture. PMID:21426555

New insights into Acinetobacter baumannii pathogenesis revealed by high-density pyrosequencing and transposon mutagenesis.

PubMed

Smith, Michael G; Gianoulis, Tara A; Pukatzki, Stefan; Mekalanos, John J; Ornston, L Nicholas; Gerstein, Mark; Snyder, Michael

2007-03-01

Acinetobacter baumannii has emerged as an important and problematic human pathogen as it is the causative agent of several types of infections including pneumonia, meningitis, septicemia, and urinary tract infections. We explored the pathogenic content of this harmful pathogen using a combination of DNA sequencing and insertional mutagenesis. The genome of this organism was sequenced using a strategy involving high-density pyrosequencing, a novel, rapid method of high-throughput sequencing. Excluding the rDNA repeats, the assembled genome is 3,976,746 base pairs (bp) and has 3830 ORFs. A significant fraction of ORFs (17.2%) are located in 28 putative alien islands, indicating that the genome has acquired a large amount of foreign DNA. Consistent with its role in pathogenesis, a remarkable number of the islands (16) contain genes implicated in virulence, indicating the organism devotes a considerable portion of its genes to pathogenesis. The largest island contains elements homologous to the Legionella/Coxiella Type IV secretion apparatus. Type IV secretion systems have been demonstrated to be important for virulence in other organisms and thus are likely to help mediate pathogenesis of A. baumannii. Insertional mutagenesis generated avirulent isolates of A. baumannii and verified that six of the islands contain virulence genes, including two novel islands containing genes that lacked homology with others in the databases. The DNA sequencing approach described in this study allows the rapid elucidation of the DNA sequence of any microbe and, when combined with genetic screens, can identify many novel genes important for microbial pathogenesis.

Selenium and breast-feeding.

PubMed

Dorea, Jose G

2002-11-01

The objective of the present review is to discuss Se nutrition during breast-feeding, encompassing environmental and maternal constitutional factors affecting breast-milk-Se metabolism and secretion. A literature search of Medline and Webofscience was used to retrieve and select papers dealing with Se and breast milk. Although Se in natural foods occurs only in organic form, breast milk responds to organic and inorganic Se in supplements. Inorganic Se (selenite, selenate), which is largely used in maternal supplements, is not detectable in breast milk. The mammary-gland regulating mechanism controls the synthesis and secretion of seleno-compounds throughout lactation, with a high total Se level in colostrum that decreases as lactation progresses. Se appears in breast milk as a component of specific seleno-proteins and seleno-amino-acids in milk proteins that are well tolerated by breast-fed infants even in high amounts. Se in breast milk occurs as glutathione peroxidase (4-32 % total Se) > selenocystamine > selenocystine > selenomethionine. The wide range of breast-milk Se concentrations depends on Se consumed in natural foods, which reflects the Se content of the soils where they are grown. Se prophylaxis, either through soil Se fertilization or maternal supplements, is effective in raising breast-milk Se concentration. In spite of wide variation, the median Se concentration from studies worldwide are 26, 18, 15, and 17 microg/l in colostrum (0-5 d), transitional milk (6-21 d), mature milk (1-3 months) and late lactation (>5 months) respectively. Se recommendations for infants are presently not achieved in 30 % of the reported breast-milk Se concentrations; nevertheless Se status is greater in breast-fed than in formula-fed infants.

Close Encounters of Lymphoid Cells and Bacteria

PubMed Central

Cruz-Adalia, Aranzazu; Veiga, Esteban

2016-01-01

During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter. PMID:27774092

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform.

PubMed

Emaminejad, Sam; Gao, Wei; Wu, Eric; Davies, Zoe A; Yin Yin Nyein, Hnin; Challa, Samyuktha; Ryan, Sean P; Fahad, Hossain M; Chen, Kevin; Shahpar, Ziba; Talebi, Salmonn; Milla, Carlos; Javey, Ali; Davis, Ronald W

2017-05-02

Perspiration-based wearable biosensors facilitate continuous monitoring of individuals' health states with real-time and molecular-level insight. The inherent inaccessibility of sweat in sedentary individuals in large volume (≥10 µL) for on-demand and in situ analysis has limited our ability to capitalize on this noninvasive and rich source of information. A wearable and miniaturized iontophoresis interface is an excellent solution to overcome this barrier. The iontophoresis process involves delivery of stimulating agonists to the sweat glands with the aid of an electrical current. The challenge remains in devising an iontophoresis interface that can extract sufficient amount of sweat for robust sensing, without electrode corrosion and burning/causing discomfort in subjects. Here, we overcame this challenge through realizing an electrochemically enhanced iontophoresis interface, integrated in a wearable sweat analysis platform. This interface can be programmed to induce sweat with various secretion profiles for real-time analysis, a capability which can be exploited to advance our knowledge of the sweat gland physiology and the secretion process. To demonstrate the clinical value of our platform, human subject studies were performed in the context of the cystic fibrosis diagnosis and preliminary investigation of the blood/sweat glucose correlation. With our platform, we detected the elevated sweat electrolyte content of cystic fibrosis patients compared with that of healthy control subjects. Furthermore, our results indicate that oral glucose consumption in the fasting state is followed by increased glucose levels in both sweat and blood. Our solution opens the possibility for a broad range of noninvasive diagnostic and general population health monitoring applications.

Pharmacological chaperones facilitate the post-ER transport of recombinant N370S mutant β-glucocerebrosidase in plant cells: Evidence that N370S is a folding mutant

PubMed Central

Babajani, Gholamreza; Tropak, Michael B.; Mahuran, Don J.; Kermode, Allison R.

2012-01-01

Gaucher disease is a prevalent lysosomal storage disease in which affected individuals inherit mutations in the gene (GBA1) encoding lysosomal acid β-glucosidase (glucocerebrosidase, GCase, EC 3.2.1.45). One of the most prevalent disease-causing mutations in humans is a N370S missense mutation in the GCase protein. As part of a larger endeavor to study the fate of mutant human proteins expressed in plant cells, the N370S mutant protein along with the wild-type- (WT)-GCase, both equipped with a signal peptide, were synthesized in transgenic tobacco BY2 cells, which do not possess lysosomes. The enzymatic activity of plant-recombinant N370S GCase lines was significantly lower (by 81–95%) than that of the WT-GCase lines. In contrast to the WT-GCase protein, which was efficiently secreted from tobacco BY2 cells, and detected in large amounts in the culture medium, only a small proportion of the N370S GCase was secreted. Pharmacological chaperones such as N-(n-nonyl) deoxynojirimycin and ambroxol increased the steady-state mutant protein levels both inside the plant cells and in the culture medium. These findings contradict the assertion that small molecule chaperones increase N370S GCase activity (as assayed in treated patient cell lysates) by stabilizing the enzyme in the lysosome, and suggest that the mutant protein is impaired in its ability to obtain its functional folded conformation, which is a requirement for exiting the lumen of the ER. PMID:22592100

Transfer of methyl chloroform, trichloroethylene and tetrachloroethylene to milk, tissues and expired air following intraruminal or oral administration in lactating goats and milk-fed kids.

PubMed

Hamada, T; Tanaka, H

1995-01-01

The distribution of methyl chloroform was determined (MCF), trichloroethylene (TRI) and tetrachloroethylene (PCE) in milk, tissues and expired air by intraruminally administering 0.625 ml kg(-0.75) of an equal-volume mixture of the three compounds to lactating goats. The milk secreted during 24 h after the intraruminal administration contained 1.42 mg of MCF, 1.87 mg of TRI, 6.43 mg of PCE and 0.33 mg of trichloroethanol (TCE). MCF, TRI and PCE appeared in the blood less than 30 min after administration. Oral administration of these chemicals to milk-fed kids showed that at 3.5 h post-administration, the liver contained these chemicals in greatest abundance. The adaptation of milk-fed kids to 3 weeks administration of small amounts of propylene glycol stimulated the metabolic conversion of TRI to TCE. There were linear relationships between the blood concentrations of these chemicals and the expiration rates after oral administration of 0.4 ml kg(-1) of each chemical to milk-fed kids. The expiration rates of MCF, TRI and PCE were 605, 122 and 46 microg min(-1) kg(-1) at 2 microg ml(-1) blood concentrations of MCF, TRI and PCE, respectively. These results suggested that MCF is little metabolized, being most readily exhaled in expired air, while PCE demonstrates the greatest tissue-partitioning, being largely secreted into the milk or retained in the liver. TRI can be extensively metabolized to other compounds such as TCE in milk-fed kids.

Cdc1 removes the ethanolamine phosphate of the first mannose of GPI anchors and thereby facilitates the integration of GPI proteins into the yeast cell wall

PubMed Central

Vazquez, Hector M.; Vionnet, Christine; Roubaty, Carole; Conzelmann, Andreas

2014-01-01

Temperature-sensitive cdc1ts mutants are reported to stop the cell cycle upon a shift to 30°C in early G2, that is, as small budded cells having completed DNA replication but unable to duplicate the spindle pole body. A recent report showed that PGAP5, a human homologue of CDC1, acts as a phosphodiesterase removing an ethanolamine phosphate (EtN-P) from mannose 2 of the glycosylphosphatidylinositol (GPI) anchor, thus permitting efficient endoplasmic reticulum (ER)-to-Golgi transport of GPI proteins. We find that the essential CDC1 gene can be deleted in mcd4∆ cells, which do not attach EtN-P to mannose 1 of the GPI anchor, suggesting that Cdc1 removes the EtN-P added by Mcd4. Cdc1-314ts mutants do not accumulate GPI proteins in the ER but have a partial secretion block later in the secretory pathway. Growth tests and the genetic interaction profile of cdc1-314ts pinpoint a distinct cell wall defect. Osmotic support restores GPI protein secretion and actin polarization but not growth. Cell walls of cdc1-314ts mutants contain large amounts of GPI proteins that are easily released by β-glucanases and not attached to cell wall β1,6-glucans and that retain their original GPI anchor lipid. This suggests that the presumed transglycosidases Dfg5 and Dcw1 of cdc1-314ts transfer GPI proteins to cell wall β1,6-glucans inefficiently. PMID:25165136

Hiding Information Using different lighting Color images

NASA Astrophysics Data System (ADS)

Majead, Ahlam; Awad, Rash; Salman, Salema S.

2018-05-01

The host medium for the secret message is one of the important principles for the designers of steganography method. In this study, the best color image was studied to carrying any secret image.The steganography approach based Lifting Wavelet Transform (LWT) and Least Significant Bits (LSBs) substitution. The proposed method offers lossless and unnoticeable changes in the contrast carrier color image and imperceptible by human visual system (HVS), especially the host images which was captured in dark lighting conditions. The aim of the study was to study the process of masking the data in colored images with different light intensities. The effect of the masking process was examined on the images that are classified by a minimum distance and the amount of noise and distortion in the image. The histogram and statistical characteristics of the cover image the results showed the efficient use of images taken with different light intensities in hiding data using the least important bit substitution method. This method succeeded in concealing textual data without distorting the original image (low light) Lire developments due to the concealment process.The digital image segmentation technique was used to distinguish small areas with masking. The result is that smooth homogeneous areas are less affected as a result of hiding comparing with high light areas. It is possible to use dark color images to send any secret message between two persons for the purpose of secret communication with good security.

How to get into bones: proton pump and carbonic anhydrase in Osedax boneworms

PubMed Central

Tresguerres, Martin; Katz, Sigrid; Rouse, Greg W.

2013-01-01

Osedax are gutless siboglinid worms that thrive on vertebrate bones lying on the ocean floor, mainly those of whales. The posterior body of female Osedax penetrates into the bone forming extensions known as ‘roots’, which host heterotrophic symbiotic bacteria in bacteriocytes beneath the epidermis. The Osedax root epithelium presumably absorbs bone collagen and/or lipids, which are metabolized by the symbiotic bacteria that in turn serve for Osedax's nutrition. Here, we show that Osedax roots express extremely high amounts of vacuolar-H+-ATPase (VHA), which is located in the apical membrane and in cytoplasmic vesicles of root and ovisac epithelial cells. The enzyme carbonic anhydrase (CA), which catalyses the hydration of CO2 into H+ and HCO3−, is also expressed in roots and throughout Osedax body. These results suggest Osedax roots have massive acid-secreting capacity via VHA, fuelled by H+ derived from the CA-catalysed hydration of CO2 produced by aerobic metabolism. We propose the secreted acid dissolves the bone carbonate matrix to then allow the absorption of bone-derived nutrients across the skin. In an exciting example of convergent evolution, this model for acid secretion is remarkably similar to mammalian osteoclast cells. However, while osteoclasts dissolve bone for repairing and remodelling, the Osedax root epithelium secretes acid to dissolve foreign bone to access nutrients. PMID:23760644

Aspergillus niger Secretes Citrate to Increase Iron Bioavailability

PubMed Central

Odoni, Dorett I.; van Gaal, Merlijn P.; Schonewille, Tom; Tamayo-Ramos, Juan A.; Martins dos Santos, Vitor A. P.; Suarez-Diez, Maria; Schaap, Peter J.

2017-01-01

Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts of iron added to the culture medium and, in contrast to previous findings, this response is independent of the nitrogen source. Differential transcriptomics analyses of the two A. niger mutants NW305 (gluconate non-producer) and NW186 (gluconate and oxalate non-producer) revealed up-regulation of the citrate biosynthesis gene citA under iron limited conditions compared to iron replete conditions. In addition, we show that A. niger can utilize Fe(III) citrate as iron source. Finally, we discuss our findings in the general context of the pH-dependency of A. niger organic acid production, offering an explanation, besides competition, for why A. niger organic acid production is a sequential process influenced by the external pH of the culture medium. PMID:28824560

Quantitative proteomic view on secreted, cell surface-associated, and cytoplasmic proteins of the methicillin-resistant human pathogen Staphylococcus aureus under iron-limited conditions.

PubMed

Hempel, Kristina; Herbst, Florian-Alexander; Moche, Martin; Hecker, Michael; Becher, Dörte

2011-04-01

Staphylococcus aureus is capable of colonizing and infecting humans by its arsenal of surface-exposed and secreted proteins. Iron-limited conditions in mammalian body fluids serve as a major environmental signal to bacteria to express virulence determinants. Here we present a comprehensive, gel-free, and GeLC-MS/MS-based quantitative proteome profiling of S. aureus under this infection-relevant situation. (14)N(15)N metabolic labeling and three complementing approaches were combined for relative quantitative analyses of surface-associated proteins. The surface-exposed and secreted proteome profiling approaches comprise trypsin shaving, biotinylation, and precipitation of the supernatant. By analysis of the outer subproteomic and cytoplasmic protein fraction, 1210 proteins could be identified including 221 surface-associated proteins. Thus, access was enabled to 70% of the predicted cell wall-associated proteins, 80% of the predicted sortase substrates, two/thirds of lipoproteins and more than 50% of secreted and cytoplasmic proteins. For iron-deficiency, 158 surface-associated proteins were quantified. Twenty-nine proteins were found in altered amounts showing particularly surface-exposed proteins strongly induced, such as the iron-regulated surface determinant proteins IsdA, IsdB, IsdC and IsdD as well as lipid-anchored iron compound-binding proteins. The work presents a crucial subject for understanding S. aureus pathophysiology by the use of methods that allow quantitative surface proteome profiling.

Microbially induced selective flotation of sphalerite from galena using mineral-adapted strains of Bacillus megaterium.

PubMed

Vasanthakumar, B; Ravishankar, H; Subramanian, S

2013-12-01

The selective flotation of sphalerite from a sphalerite-galena mineral mixture has been achieved using cells and extracellular secretions of Bacillus megaterium after adaptation to the chosen minerals. The extracellular secretions obtained after thermolysis of bacterial cells adapted to sphalerite yield the highest flotation recovery of sphalerite with a selectivity index value of 24.5, in comparison to the other cellular and extra-cellular bio-reagents studied. The protein profile for the unadapted and mineral-adapted cells has been found to differ distinctly, attesting to variation in the yield and nature of extra-cellular polymeric substances (EPS). The changes induced in the bacterial cell wall components after adaptation to sphalerite or galena with respect to the contents of phosphate, uronic acid and acetylated sugars of B. megaterium have been quantified. The role of the dissolved metal ions from the minerals as well as that of the constituents of extracellular secretions in modulating the surface charge of the bacterial cells as well as the minerals under study has been confirmed using various enzymatic treatments of the bacterial cells. It has been demonstrated that the induction of additional molecular weight protein fractions as well as the higher amount of extracellular proteins and phosphate secreted after adaptation to sphalerite vis-à-vis galena are contributory factors for the selective separation of sphalerite from galena. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative characterization of proteins secreted by Neurospora sitophila in solid-state and submerged fermentation.

PubMed

Li, Yanjun; Peng, Xiaowei; Chen, Hongzhang

2013-10-01

Although submerged fermentation (SmF) accounts for most of current enzyme industries, it has been reported that solid-state fermentation (SSF) can produce higher enzyme yields in laboratory scale. In order to understand the reasons contributing to high enzyme production in SSF, this study compared the cellulase activities and secretomes of Neurospora sitophila cultured in SSF and SmF using steam exploded wheat straw as carbon source and enzyme inducer. The total amounts of protein and biomass (glucosamine content) in SSF were respectively 30 and 2.8 times of those in SmF. The CMCase, FPA and β-glucoside activities in SSF were 53-181 times of those in SmF. Both in SSF and SmF, N. sitophila secreted the most critical cellulases and hemicellulases known for Trichoderma reesei, although a β-xylosidase was exclusively identified in SSF. Six endoglucanases were identified in N. sitophila secretion with the high CMCase activity. The non-enzyme proteins in SSF were involved in fungal mycelia growth and conidiation; while those in SmF were more related to glycometabolism and stress tolerance. This revealed that SSF more likely serves as a natural habitat for filamentous fungi to facilitate the enzyme secretion. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Maltose-Binding Protein Enhances Secretion of Recombinant Human Granzyme B Accompanied by In Vivo Processing of a Precursor MBP Fusion Protein

PubMed Central

Dälken, Benjamin; Jabulowsky, Robert A.; Oberoi, Pranav; Benhar, Itai; Wels, Winfried S.

2010-01-01

Background The apoptosis-inducing serine protease granzyme B (GrB) is an important factor contributing to lysis of target cells by cytotoxic lymphocytes. Expression of enzymatically active GrB in recombinant form is a prerequisite for functional analysis and application of GrB for therapeutic purposes. Methods and Findings We investigated the influence of bacterial maltose-binding protein (MBP) fused to GrB via a synthetic furin recognition motif on the expression of the MBP fusion protein also containing an N-terminal α-factor signal peptide in the yeast Pichia pastoris. MBP markedly enhanced the amount of GrB secreted into culture supernatant, which was not the case when GrB was fused to GST. MBP-GrB fusion protein was cleaved during secretion by an endogenous furin-like proteolytic activity in vivo, liberating enzymatically active GrB without the need of subsequent in vitro processing. Similar results were obtained upon expression of a recombinant fragment of the ErbB2/HER2 receptor protein or GST as MBP fusions. Conclusions Our results demonstrate that combination of MBP as a solubility enhancer with specific in vivo cleavage augments secretion of processed and functionally active proteins from yeast. This strategy may be generally applicable to improve folding and increase yields of recombinant proteins. PMID:21203542

Altered redox state of monocytes from cryopyrin-associated periodic syndromes causes accelerated IL-1β secretion

PubMed Central

Tassi, Sara; Carta, Sonia; Delfino, Laura; Caorsi, Roberta; Martini, Alberto; Gattorno, Marco; Rubartelli, Anna

2010-01-01

In healthy monocytes, Toll-like receptor (TLR) engagement induces production of reactive oxygen species (ROS), followed by an antioxidant response involved in IL-1β processing and secretion. Markers of the antioxidant response include intracellular thioredoxin and extracellular release of reduced cysteine. Cryopyrin-associated periodic syndromes (CAPS) are autoinflammatory diseases in which Nod-like receptor family pyrin domain–containing 3 (NLRP3) gene mutations lead to increased IL-1β secretion. We show in a large cohort of patients that IL-1β secretion by CAPS monocytes is much faster than that by healthy monocytes. This accelerated kinetics is caused by alterations in the basal redox state, as well as in the redox response to TLR triggering displayed by CAPS monocytes. Indeed, unstimulated CAPS monocytes are under a mild oxidative stress, with elevated levels of both ROS and antioxidants. The redox response to LPS is quickened, with early generation of the reducing conditions favoring IL-1β processing and secretion, and then rapidly exhausted. Therefore, secretion of IL-1β is accelerated, but reaches a plateau much earlier than in healthy controls. Pharmacologic inhibition of the redox response hinders IL-1β release, confirming the functional link between redox impairment and altered kinetics of secretion. Monocytes from patients with juvenile idiopathic arthritis display normal kinetics of redox response and IL-1β secretion, excluding a role of chronic inflammation in the alterations observed in CAPS. We conclude that preexisting redox alterations distinct from CAPS monocytes anticipate the pathogen-associated molecular pattern molecule–induced generation of the reducing environment favorable to inflammasome activation and IL-1β secretion. PMID:20445104

Altered redox state of monocytes from cryopyrin-associated periodic syndromes causes accelerated IL-1beta secretion.

PubMed

Tassi, Sara; Carta, Sonia; Delfino, Laura; Caorsi, Roberta; Martini, Alberto; Gattorno, Marco; Rubartelli, Anna

2010-05-25

In healthy monocytes, Toll-like receptor (TLR) engagement induces production of reactive oxygen species (ROS), followed by an antioxidant response involved in IL-1beta processing and secretion. Markers of the antioxidant response include intracellular thioredoxin and extracellular release of reduced cysteine. Cryopyrin-associated periodic syndromes (CAPS) are autoinflammatory diseases in which Nod-like receptor family pyrin domain-containing 3 (NLRP3) gene mutations lead to increased IL-1beta secretion. We show in a large cohort of patients that IL-1beta secretion by CAPS monocytes is much faster than that by healthy monocytes. This accelerated kinetics is caused by alterations in the basal redox state, as well as in the redox response to TLR triggering displayed by CAPS monocytes. Indeed, unstimulated CAPS monocytes are under a mild oxidative stress, with elevated levels of both ROS and antioxidants. The redox response to LPS is quickened, with early generation of the reducing conditions favoring IL-1beta processing and secretion, and then rapidly exhausted. Therefore, secretion of IL-1beta is accelerated, but reaches a plateau much earlier than in healthy controls. Pharmacologic inhibition of the redox response hinders IL-1beta release, confirming the functional link between redox impairment and altered kinetics of secretion. Monocytes from patients with juvenile idiopathic arthritis display normal kinetics of redox response and IL-1beta secretion, excluding a role of chronic inflammation in the alterations observed in CAPS. We conclude that preexisting redox alterations distinct from CAPS monocytes anticipate the pathogen-associated molecular pattern molecule-induced generation of the reducing environment favorable to inflammasome activation and IL-1beta secretion.

Comparative Analysis of Volatile Defensive Secretions of Three Species of Pyrrhocoridae (Insecta: Heteroptera) by Gas Chromatography-Mass Spectrometric Method

PubMed Central

Krajicek, Jan; Havlikova, Martina; Bursova, Miroslava; Ston, Martin; Cabala, Radomir; Exnerova, Alice; Stys, Pavel; Bosakova, Zuzana

2016-01-01

The true bugs (Hemiptera: Heteroptera) have evolved a system of well-developed scent glands that produce diverse and frequently strongly odorous compounds that act mainly as chemical protection against predators. A new method of non-lethal sampling with subsequent separation using gas chromatography with mass spectrometric detection was proposed for analysis of these volatile defensive secretions. Separation was performed on Rtx-200 column containing fluorinated polysiloxane stationary phase. Various mechanical irritation methods (ultrasonics, shaking, pressing bugs with plunger of syringe) were tested for secretion sampling with a special focus on non-lethal irritation. The preconcentration step was performed by sorption on solid phase microextraction (SPME) fibers with different polarity. For optimization of sampling procedure, Pyrrhocoris apterus was selected. The entire multi-parameter optimization procedure of secretion sampling was performed using response surface methodology. The irritation of bugs by pressing them with a plunger of syringe was shown to be the most suitable. The developed method was applied to analysis of secretions produced by adult males and females of Pyrrhocoris apterus, Pyrrhocoris tibialis and Scantius aegyptius (all Heteroptera: Pyrrhocoridae). The chemical composition of secretion, particularly that of alcohols, aldehydes and esters, is species-specific in all three pyrrhocorid species studied. The sexual dimorphism in occurrence of particular compounds is largely limited to alcohols and suggests their epigamic intraspecific function. The phenetic overall similarities in composition of secretion do not reflect either relationship of species or similarities in antipredatory color pattern. The similarities of secretions may be linked with antipredatory strategies. The proposed method requires only a few individuals which remain alive after the procedure. Thus secretions of a number of species including even the rare ones can be analyzed and broadly conceived comparative studies can be carried out. PMID:27997627

United States Department of Agriculture-Agricultural Research Service studies on polyketide toxins of Fusarium oxysporum f sp vasinfectum: potential targets for disease control.

PubMed

Bell, Alois A; Wheeler, Michael H; Liu, Jinggao; Stipanovic, Robert D; Puckhaber, Lorraine S; Orta, Heather

2003-01-01

A group of 133 isolates of the cotton wilt pathogen Fusarium oxysporum Schlecht f sp vasinfectum (Atk) Sny & Hans, representing five races and 20 vegetative compatibility groups within race 1 were used to determine the identity, biosynthetic regulation and taxonomic distribution of polyketide toxins produced by this pathogen. All isolates of F oxysporum f sp vasinfectum produced and secreted the nonaketide naphthazarin quinones, bikaverin and norbikaverin. Most isolates of race 1 (previously denoted as races 1, 2 and 6; and also called race A) also synthesized the heptaketide naphthoquinones, nectriafurone, anhydrofusarubin lactol and 5-O-methyljavanicin. Nine avirulent isolates of F oxysporum from Upland cotton roots, three isolates of race 3 of F oxysporum f sp vasinfectum, and four isolates of F oxysporum f sp vasinfectum from Australia, all of which previously failed to cause disease of Upland cotton (Gossypium hirsutum L) in stem-puncture assays, also failed to synthesize or secrete more than trace amounts of the heptaketide compounds. These results indicate that the heptaketides may have a unique role in the virulence of race 1 to Upland cotton. The synthesis of all polyketide toxins by ATCC isolate 24908 of F oxysporum f sp vasinfectum was regulated by pH, carbon/nitrogen ratios, and availability of calcium in media. Synthesis was greatest below pH 7.0 and increased progressively as carbon/nitrogen ratios were increased by decreasing the amounts of nitrogen added to media. The nonaketides were the major polyketides accumulated in synthetic media at pH 4.5 and below, whereas the heptaketides were predominant at pH 5.0 and above. The heptaketides were the major polyketides formed when 10 F oxysporum f sp vasinfectum race 1 isolates were grown on sterilized stems of Fusarium wilt-susceptible cotton cultivars, but these compounds were not produced on sorghum grain cultures. Both groups of polyketide toxins were apparently secreted by F oxysporum f sp vasinfectum, since half of the toxin in 2-day-old shake culture was present in the supernatant. Secretion was enhanced by calcium. Glutamine and glutamic acid inhibited both nonaketide and heptaketide syntheses, even at low nitrogen

Effect of a Semi-Purified Oligosaccharide-Enriched Fraction from Caprine Milk on Barrier Integrity and Mucin Production of Co-Culture Models of the Small and Large Intestinal Epithelium

PubMed Central

Barnett, Alicia M.; Roy, Nicole C.; McNabb, Warren C.; Cookson, Adrian L.

2016-01-01

Caprine milk contains the highest amount of oligosaccharides among domestic animals, which are structurally similar to human milk oligosaccharides (HMOs). This suggests caprine milk oligosaccharides may offer similar protective and developmental effects to that of HMOs. However, to date, studies using oligosaccharides from caprine milk have been limited. Thus, this study aimed to examine the impact of a caprine milk oligosaccharide-enriched fraction (CMOF) on barrier function of epithelial cell co-cultures of absorptive enterocytes (Caco-2 cells) and mucus-secreting goblet cells (HT29-MTX cells), that more closely simulate the cell proportions found in the small (90:10) and large intestine (75:25). Treatment of epithelial co-cultures with 0.4, 1.0, 2.0 and 4.0 mg/mL of CMOF was shown to have no effect on metabolic activity but did enhance cell epithelial barrier integrity as measured by trans-epithelial electrical resistance (TEER), in a dose-dependent manner. The CMOF at the maximum concentration tested (4.0 mg/mL) enhanced TEER, mucin gene expression and mucin protein abundance of epithelial co-cultures, all of which are essential components of intestinal barrier function. PMID:27164134

Effect of a Semi-Purified Oligosaccharide-Enriched Fraction from Caprine Milk on Barrier Integrity and Mucin Production of Co-Culture Models of the Small and Large Intestinal Epithelium.

PubMed

Barnett, Alicia M; Roy, Nicole C; McNabb, Warren C; Cookson, Adrian L

2016-05-06

Caprine milk contains the highest amount of oligosaccharides among domestic animals, which are structurally similar to human milk oligosaccharides (HMOs). This suggests caprine milk oligosaccharides may offer similar protective and developmental effects to that of HMOs. However, to date, studies using oligosaccharides from caprine milk have been limited. Thus, this study aimed to examine the impact of a caprine milk oligosaccharide-enriched fraction (CMOF) on barrier function of epithelial cell co-cultures of absorptive enterocytes (Caco-2 cells) and mucus-secreting goblet cells (HT29-MTX cells), that more closely simulate the cell proportions found in the small (90:10) and large intestine (75:25). Treatment of epithelial co-cultures with 0.4, 1.0, 2.0 and 4.0 mg/mL of CMOF was shown to have no effect on metabolic activity but did enhance cell epithelial barrier integrity as measured by trans-epithelial electrical resistance (TEER), in a dose-dependent manner. The CMOF at the maximum concentration tested (4.0 mg/mL) enhanced TEER, mucin gene expression and mucin protein abundance of epithelial co-cultures, all of which are essential components of intestinal barrier function.

Polymers for Improving the In Vivo Transduction Efficiency of AAV2 Vectors

PubMed Central

Moulay, Gilles; Boutin, Sylvie; Masurier, Carole; Scherman, Daniel; Kichler, Antoine

2010-01-01

Background Adeno-associated virus has attracted great attention as vehicle for body-wide gene delivery. However, for the successful treatment of a disease such as Duchenne muscular dystrophy infusion of very large amounts of vectors is required. This not only raises questions about the technical feasibility of the large scale production but also about the overall safety of the approach. One way to overcome these problems would be to find strategies able to increase the in vivo efficiency. Methodology Here, we investigated whether polymers can act as adjuvants to increase the in vivo efficiency of AAV2. Our strategy consisted in the pre-injection of polymers before intravenous administration of mice with AAV2 encoding a murine secreted alkaline phosphatase (mSeAP). The transgene expression, vector biodistribution and tissue transduction were studied by quantification of the mSeAP protein and real time PCR. The injection of polyinosinic acid and polylysine resulted in an increase of plasmatic mSeAP of 2- and 12-fold, respectively. Interestingly, polyinosinic acid pre-injection significantly reduced the neutralizing antibody titer raised against AAV2. Conclusions Our results show that the pre-injection of polymers can improve the overall transduction efficiency of systemically administered AAV2 and reduce the humoral response against the capsid proteins. PMID:21203395

The Critical Importance of Urinary Concentrating Ability in the Generation of Urinary Carbon Dioxide Tension

PubMed Central

Arruda, Jose A. L.; Nascimento, Luiz; Mehta, Pradeep K.; Rademacher, Donald R.; Sehy, John T.; Westenfelder, Christof; Kurtzman, Neil A.

1977-01-01

Measurement of urine to blood (U-B) carbon dioxide tension (PCO2) gradient during alkalinization of the urine has been suggested to assess distal H+ secretion. A fact that has not been considered in previous studies dealing with urinary PCO2 is that dissolution of HCO3 in water results in elevation of PCO2 which is directly proportional to the HCO3 concentration. To investigate the interrelationship of urinary HCO3 and urinary acidification, we measured U-B PCO2 in (a) the presence of enhanced H+ secretion and decreased concentrating ability i.e., chronic renal failure (CRF), (b) animals with normal H+ secretion and decreased concentrating ability, Brattleboro (BB) rats, and (c) the presence of both impaired H+ secretion and concentrating ability (LiCl treatment and after release of unilateral ureteral obstruction). At moderately elevated plasma HCO3 levels (30-40 meq/liter), normal rats achieved a highly alkaline urine (urine pH > 7.8) and raised urine HCO3 concentration and U-B PCO2. At similar plasma HCO3 levels, BB rats had a much higher fractional water excretion and failed to raise urine pH, urine HCO3 concentration, and U-B PCO2 normally. At a very high plasma HCO3 (>50 meq/liter), BB rats raised urine pH, urine HCO3 concentration, and U-B PCO2 to the same levels seen in normals. CRF rats failed to raise urine pH, urine HCO3, and U-B PCO2 normally at moderately elevated plasma HCO3 levels; at very high plasma HCO3 levels, CRF rats achieved a highly alkaline urine but failed to raise U-B PCO2. Dogs and patients with CRF were also unable to raise urine pH, urine HCO3 concentration, and U-B PCO2 normally at moderately elevated plasma HCO3 levels. In rats, dogs, and man, U-B PCO2 was directly related to urine HCO3 concentration and inversely related to fractional water excretion. At moderately elevated plasma HCO3 levels, animals with a distal acidification defect failed to raise U-B PCO2; increasing the plasma HCO3 to very high levels resulted in a significant increase in urine HCO3 concentration and U-B PCO2. The observed urinary PCO2 was very close to the PCO2 which would be expected by simple dissolution of a comparable amount of HCO3 in water. These data demonstrate that, in highly alkaline urine, urinary PCO2 is largely determined by concentration of urinary HCO3 and cannot be used as solely indicating distal H+ secretion. PMID:893680

JPRS Report, Soviet Union, Political Affairs, Preparations for the 19th Party Conference.

DTIC Science & Technology

1988-10-30

Russia’s trade union movement in 1910. The secret police, whose agent he was, was preparing him for a big game. Unfortunately, it largely succeeded in... agent of the secret police department. In the fall of 1918 Malinovskiy returned to Petrograd and, after being sentenced by the All-Russian Central...structures which would give authorized agents (the workers and peasants themselves) an opportunity to inspect any documents and materials concerning

Glycopattern analysis of acidic secretion in the intestine of the red-eared slender turtle; Trachemys scripta elegans (Testudines: Emydidae).

PubMed

Scillitani, Giovanni; Mentino, Donatella; Mastrodonato, Maria

2017-10-01

The secretion of the goblet cells in the intestine of Trachemys scripta elegans was studied in situ by histochemical methods to analyze the diversity of sugar chains, with particular regard to the acidic glycans. Conventional histochemical stains (Periodic acid-Schiff, Alcian Blue pH 2.5, High Iron Diamine) and binding with ten FITC-labelled lectins combined with chemical and enzymatic pre-treatments were used to characterize the oligosaccharidic chains. The intestine can be divided into three regions, i.e. a duodenum, a small intestine and a large intestine. Goblet cells were observed in all the three tracts and presented an acidic secretion. WGA, LFA, PNA and SBA binding was observed only after desulfation. Glycans secreted by the three tracts consist mainly of sulfosialomucins with 1,2-linked fucose, mannosylated, glucosaminylated and subterminal galactosyl/galactosaminylated residuals. Differences among tracts are quantitative rather than qualitative, with sulfated, galactosaminylated and glycosaminylated residuals increasing from duodenum to large intestine, and galactosylated and fucosylated residuals showing an opposite trend. Variation is observed also between apices and bases of villi in both duodenum and small intestine, where sulphation decreases from the base to the apex and glycosylation shows an opposite trend. Functional implication of these findings is discussed in a comparative context. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stimulus-secretion coupling in chromaffin cells isolated from bovine adrenal medulla

PubMed Central

Schneider, Allan S.; Herz, Ruth; Rosenheck, Kurt

1977-01-01

Bovine adrenal chromaffin cells were isolated by removal of the cortex and sequential collagenase digestion of the medulla. The catecholamine secretory function of these cells was characterized with respect to acetylcholine stimulation, cation requirements, and cytoskeletal elements. The dose-response curve for stimulated release had its half-maximum value at 10-5 M acetylcholine, and maximum secretion was on the average 7 times that of control basal secretion. The differential release of epinephrine versus norepinephrine after stimulation with 0.1 mM acetylcholine occurred in proportion to their distribution in the cell suspension. The cholinergic receptors were found to be predominantly nicotinic. The kinetics of catecholamine release were rapid, with significant secretion occurring in less than 60 sec and 85% of maximum secretion within 5 min. A critical requirement for calcium in the extracellular medium was demonstrated, and 80% of maximum secretion was achieved at physiologic calcium concentrations. Stimulation by excess potassium (65 mM KCl) also induced catecholamine secretion which differed from acetylcholine stimulation in being less potent, in having a different dependence on calcium concentration, and in its response to the local anesthetic tetracaine. Tetracaine, which is thought to inhibit membrane cation permeability, was able to block acetylcholine-stimulated but not KCl-stimulated secretion. The microtubule disrupting agent vinblastine was able to block catecholamine release whereas the microfilament disrupter cytochalasin B had little effect. The results show the isolated bovine chromaffin cells to be viable, functioning, and available in large quantity. These cells now provide an excellent system for studying cell surface regulation of hormone and neurotransmitter release. PMID:270738

Structural Basis of Chemokine Sequestration by CrmD, a Poxvirus-Encoded Tumor Necrosis Factor Receptor

PubMed Central

Wang, Dongli; Chen, Dongwei; He, Guangjun; Huang, Li; Wang, Hanzhong; Wang, Xinquan

2011-01-01

Pathogens have evolved sophisticated mechanisms to evade detection and destruction by the host immune system. Large DNA viruses encode homologues of chemokines and their receptors, as well as chemokine-binding proteins (CKBPs) to modulate the chemokine network in host response. The SECRET domain (smallpox virus-encoded chemokine receptor) represents a new family of viral CKBPs that binds a subset of chemokines from different classes to inhibit their activities, either independently or fused with viral tumor necrosis factor receptors (vTNFRs). Here we present the crystal structures of the SECRET domain of vTNFR CrmD encoded by ectromelia virus and its complex with chemokine CX3CL1. The SECRET domain adopts a β-sandwich fold and utilizes its β-sheet I surface to interact with CX3CL1, representing a new chemokine-binding manner of viral CKBPs. Structure-based mutagenesis and biochemical analysis identified important basic residues in the 40s loop of CX3CL1 for the interaction. Mutation of corresponding acidic residues in the SECRET domain also affected the binding for other chemokines, indicating that the SECRET domain binds different chemokines in a similar manner. We further showed that heparin inhibited the binding of CX3CL1 by the SECRET domain and the SECRET domain inhibited RAW264.7 cell migration induced by CX3CL1. These results together shed light on the structural basis for the SECRET domain to inhibit chemokine activities by interfering with both chemokine-GAG and chemokine-receptor interactions. PMID:21829356

Development of the cortisol circadian rhythm in the light of stress early in life.

PubMed

Simons, Sterre S H; Beijers, Roseriet; Cillessen, Antonius H N; de Weerth, Carolina

2015-12-01

The secretion of the stress hormone cortisol follows a diurnal circadian rhythm. There are indications that this rhythm is affected by stress early in life. This paper addresses the development of the cortisol circadian rhythm between 1 and 6 years of age, and the role of maternal stress and anxiety early in the child's life on this (developing) rhythm. Participants were 193 healthy mother-child dyads from a community sample. Self-reported maternal stress and anxiety and physiological stress (saliva cortisol), were assessed prenatally (gestational week 37). Postnatally, self-reported maternal stress and anxiety were measured at 3, 6, 12, 30, and 72 months. Saliva cortisol samples from the children were collected on two days (four times each day) at 12, 30, and 72 months of age. The total amount of cortisol during the day and the cortisol decline over the day were determined to indicate children's cortisol circadian rhythm. Multilevel analyses showed that the total amount of cortisol decreased between 1 and 6 years. Furthermore, more maternal pregnancy-specific stress was related to higher total amounts of cortisol in the child. Higher levels of early postnatal maternal anxiety were associated with flatter cortisol declines in children. Higher levels of early postnatal maternal daily hassles were associated with steeper child cortisol declines over the day. These results indicated developmental change in children's cortisol secretion from 1 to 6 years and associations between maternal stress and anxiety early in children's lives and children's cortisol circadian rhythm in early childhood. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemerin regulation and role in host defense.

PubMed

Zabel, Brian A; Kwitniewski, Mateusz; Banas, Magdalena; Zabieglo, Katarzyna; Murzyn, Krzysztof; Cichy, Joanna

2014-01-01

Chemerin is a widely distributed multifunctional secreted protein implicated in immune cell migration, adipogenesis, osteoblastogenesis, angiogenesis, myogenesis, and glucose homeostasis. Chemerin message is regulated by nuclear receptor agonists, metabolic signaling proteins and intermediates, and proinflammatory cytokines. Following translation chemerin is secreted as an inactive pro-protein, and its secretion can be regulated depending on cell type. Chemerin bioactivity is largely dependent on carboxyl-terminal proteolytic processing and removal of inhibitory residues. Chemerin is abundant in human epidermis where it is well-placed to provide barrier protection. In host defense, chemerin plays dual roles as a broad spectrum antimicrobial protein and as a leukocyte attractant for macrophages, dendritic cells, and NK cells. Here we review the mechanisms underlying chemerin regulation and its function in host defense.

New immuno-PCR assay for detection of low concentrations of shiga toxin 2 and its variants.

PubMed

Zhang, Wenlan; Bielaszewska, Martina; Pulz, Matthias; Becker, Karsten; Friedrich, Alexander W; Karch, Helge; Kuczius, Thorsten

2008-04-01

Shiga toxin (Stx)-producing Escherichia coli (STEC) strains secrete toxins that are major virulence factors and diagnostic targets, but some STEC strains secrete Stx in amounts that cannot be detected using conventional cell cytotoxicity or immunological assays. Therefore, there is an urgent need for more-sensitive Stx detection methods. We describe the development of an assay that can detect low concentrations of Stx2 and its variants. An immuno-PCR Stx2 assay was developed based on an enzyme immunoassay (EIA) combining antibody capture and DNA amplification to increase the signal. The immuno-PCR assay detected 10 pg/ml of purified Stx2, compared to 1 ng/ml Stx2 detected by commercial EIA. Consequently, immuno-PCR detected Stx2 and its variants in STEC strains that produce the toxins at levels that are nondetectable by using the EIA, as well as the Stx2 in EIA-negative enriched stool cultures from patients. Our data demonstrate that the immuno-PCR developed here is a highly sensitive and specific method for the detection of trace amounts of Stx2 and Stx2 variants. It is therefore suitable for use by clinical microbiological laboratories to improve the toxin detection in clinical samples.

New Immuno-PCR Assay for Detection of Low Concentrations of Shiga Toxin 2 and Its Variants▿

PubMed Central

Zhang, Wenlan; Bielaszewska, Martina; Pulz, Matthias; Becker, Karsten; Friedrich, Alexander W.; Karch, Helge; Kuczius, Thorsten

2008-01-01

Shiga toxin (Stx)-producing Escherichia coli (STEC) strains secrete toxins that are major virulence factors and diagnostic targets, but some STEC strains secrete Stx in amounts that cannot be detected using conventional cell cytotoxicity or immunological assays. Therefore, there is an urgent need for more-sensitive Stx detection methods. We describe the development of an assay that can detect low concentrations of Stx2 and its variants. An immuno-PCR Stx2 assay was developed based on an enzyme immunoassay (EIA) combining antibody capture and DNA amplification to increase the signal. The immuno-PCR assay detected 10 pg/ml of purified Stx2, compared to 1 ng/ml Stx2 detected by commercial EIA. Consequently, immuno-PCR detected Stx2 and its variants in STEC strains that produce the toxins at levels that are nondetectable by using the EIA, as well as the Stx2 in EIA-negative enriched stool cultures from patients. Our data demonstrate that the immuno-PCR developed here is a highly sensitive and specific method for the detection of trace amounts of Stx2 and Stx2 variants. It is therefore suitable for use by clinical microbiological laboratories to improve the toxin detection in clinical samples. PMID:18272709

[A study of the sialogogic effect of cevimeline gargle].

PubMed

Yoshikawa, Chizuko; Takamatsu, Yasushi; Ogata, Kentaro; Hara, Shuuji; Tamura, Kazuo

2013-02-01

The purpose of this study was to clarify the sialogogic effect iveness of cevimeline gargle. Sequential comparison tests were conducted on healthy adult males and females who received both cevimeline and a placebo. The effect was evaluated by measuring the amount of saliva using the Saxon test and Mucus, and by recording the subjects' own perceptions of oral mucosal moisture reported according to 4 levels. First, ten subjects' measurements were taken before gargling, as well as 5 minutes, 90 minutes and 3 hours after gargling. For the cevimeline treatment, the amount of saliva reached the maximum level within 5 minutes after gargling, and a significant salivary secreting effect(p<0. 05-p<0. 001)was observed up to 90 minutes after gargling. The degree of oral moisture also reached the maximum level within 5 minutes after gargling with cevimeline, and a significant moisture effect(p<0. 05-p<0. 001)persisted up to 3 hours after gargling. After safety profiles were determined to be acceptable, an additional 19 subjects entered the study and the same results were observed. The present data, indicating that cevimeline gargle increases the saliva in healthy individuals for at least 3 hours, will be useful in clinical trials of cevimeline gargle for patients with salivary secretion disorder.

Oscillating Positive Expiratory Pressure on Respiratory Resistance in Chronic Obstructive Pulmonary Disease With a Small Amount of Secretion

PubMed Central

Gastaldi, Ada Clarice; Paredi, Paolo; Talwar, Anjana; Meah, Sally; Barnes, Peter J.; Usmani, Omar S.

2015-01-01

Abstract This study aims to evaluate the acute effects of an oscillating positive expiratory pressure device (flutter) on airways resistance in patients with chronic obstructive pulmonary disease (COPD). Randomized crossover study: 15 COPD outpatients from Asthma Lab–Royal Brompton Hospital underwent spirometry, impulse oscillometry (IOS) for respiratory resistance (R) and reactance (X), and fraction exhaled nitric oxide (FeNO) measures. Thirty minutes of flutter exercises: a “flutter-sham” procedure was used as a control, and airway responses after a short-acting bronchodilator were also assessed. Respiratory system resistance (R): in COPD patients an increase in X5insp (−0.21 to −0.33 kPa/L/s) and Fres (24.95 to 26.16 Hz) occurred immediately after flutter exercises without bronchodilator. Following 20 min of rest, a decrease in the R5, ΔR5, R20, X5, and Ax was observed, with R5, R20, and X5 values lower than baseline, with a moderate effect size; there were no changes in FeNO levels or spirometry. The use of flutter can decrease the respiratory system resistance and reactance and expiratory flow limitation in stable COPD patients with small amounts of secretions. PMID:26496331

Differential expression of decorin and biglycan genes during mouse tooth development

NASA Technical Reports Server (NTRS)

Matsuura, T.; Duarte, W. R.; Cheng, H.; Uzawa, K.; Yamauchi, M.

2001-01-01

Small leucine-rich proteoglycans (SLRPs) have a number of biological functions and some of them are thought to regulate collagen mineralizaton in bone and tooth. We have previously identified and immunolocalized two members of the SLRPs family, decorin and biglycan, in bovine tooth/periodontium. To investigate their potential roles in tooth development, we examined the mRNA expression patterns of decorin, biglycan and type I collagen in newborn (day 19) mice tooth germs by in situ hybridization. At this developmental stage, the first maxillary and mandibular molars include stages before and after secretion of the predentin matrix, respectively. The expression of decorin mRNA coincided with that of type I collagen mRNA and was mostly observed in secretory odontoblasts, while the biglycan mRNA was expressed throughout the tooth germ, including pre-secretory odontoblasts/ameloblasts, dental papilla and stellate reticulum. However, its signal in secretory odontoblasts was not as evident as that of decorin. In mandibular incisors, where a significant amount of predentin matrix and a small amount of enamel matrix were already secreted, a similar differential expression pattern was observed. In secretory ameloblasts the biglycan mRNA expression was apparent, while that of decorin was not. These differential expression patterns suggest the distinct roles of biglycan and decorin in the process of tooth development.

Parasitoid-host endocrine relations: self-reliance or co-optation?

PubMed

Cole, T J; Beckage, N E; Tan, F F; Srinivasan, A; Ramaswamy, S B

2002-12-01

High titers of juvenile hormone (JH) maintain developmental arrest in Manduca sexta larvae parasitized by Cotesia congregata. Parasitized hosts exhibit up to 9.5 times greater amounts of total hemolymph JH (from 0.6+/-0.09 to 2.51+/-0.43ng/ml) compared to non-parasitized controls. Elevated titers are observed throughout the fifth instar, even beyond egression of the parasitoids on day 5. GC-MS analysis revealed that in hemolymph of unparasitized control larvae, JH I is the major homolog and levels of JH III are negligible; in parasitized individuals the amounts of JH I, II, and III rise, and JH III predominates. Neck ligation ensured separation of M. sexta's corpora allata from the posterior section, which contained most of the parasitoids in the infected insects. When the posterior region was sampled, JHs were not detected in the non-parasitzed larvae, but in those parasitized, JH III was found (1.98+/-0.29ng/ml, 24 h post-ligation). JH III was the only homolog produced and secreted by the parasitoid in in vitro culture. This is the first report stating that a parasitoid secretes JH III and may contribute, at least in part, to the circulating titer in the host hemocoel, concurrently promoting host production of JH I and II.

Detecting 2LSB steganography using extended pairs of values analysis

NASA Astrophysics Data System (ADS)

Khalind, Omed; Aziz, Benjamin

2014-05-01

In this paper, we propose an extended pairs of values analysis to detect and estimate the amount of secret messages embedded with 2LSB replacement in digital images based on chi-square attack and regularity rate in pixel values. The detection process is separated from the estimation of the hidden message length, as it is the main requirement of any steganalysis method. Hence, the detection process acts as a discrete classifier, which classifies a given set of images into stego and clean classes. The method can accurately detect 2LSB replacement even when the message length is about 10% of the total capacity, it also reaches its best performance with an accuracy of higher than 0.96 and a true positive rate of more than 0.997 when the amount of data are 20% to 100% of the total capacity. However, the method puts no assumptions neither on the image nor the secret message, as it tested with two sets of 3000 images, compressed and uncompressed, embedded with a random message for each case. This method of detection could also be used as an automated tool to analyse a bulk of images for hidden contents, which could be used by digital forensics analysts in their investigation process.

Quantification and Evidence for Mechanically Metered Release of Pygidial Secretions in Formic Acid-Producing Carabid Beetles

PubMed Central

Will, Kipling W.; Gill, Aman S.; Lee, Hyeunjoo; Attygalle, Athula B.

2010-01-01

This study is the first to measure the quantity of pygidial gland secretions released defensively by carabid beetles (Coleoptera: Carabidae) and to accurately measure the relative quantity of formic acid contained in their pygidial gland reservoirs and spray emissions. Individuals of three typical formic acid producing species were induced to repeatedly spray, ultimately exhausting their chemical compound reserves. Beetles were subjected to faux attacks using forceps and weighed before and after each ejection of chemicals. Platynus brunneomarginatus (Mannerheim) (Platynini), P. ovipennis (Mannerheim) (Platynini) and Calathus ruficollis Dejean (Sphodrini), sprayed average quantities with standard error of 0.313 ± 0.172 mg, 0.337 ± 0.230 mg, and 0.197 ± 0.117 mg per spray event, respectively. The quantity an individual beetle released when induced to spray tended to decrease with each subsequent spray event. The quantity emitted in a single spray was correlated to the quantity held in the reservoirs at the time of spraying for beetles whose reserves are greater than the average amount emitted in a spray event. For beetles with a quantity less than the average amount sprayed in reserve there was no significant correlation. For beetles comparable in terms of size, physiological condition and gland reservoir fullness, the shape of the gland reservoirs and musculature determined that a similar effort at each spray event would mechanically meter out the release so that a greater amount was emitted when more was available in the reservoir. The average percentage of formic acid was established for these species as 34.2%, 73.5% and 34.1% for for P. brunneomarginatus, P. ovipennis and C. ruficollis, respectively. The average quantities of formic acid released by individuals of these species was less than two-thirds the amount shown to be lethal to ants in previously published experiments. However, the total quantity from multiple spray events from a single individual could aggregate to quantities at or above the lethal level, and lesser quantities are known to act as ant alarm pheromones. Using a model, one directed spray of the formic acid and hydrocarbon mix could spread to an area of 5–8 cm diameter and persisted for 9–22 seconds at a threshold level known to induce alarm behaviors in ants. These results show that carabid defensive secretions may act as a potent and relatively prolonged defense against ants or similar predators even at a sub-lethal dose. PMID:20575743

Measurement of gastric meal and secretion volumes using magnetic resonance imaging

PubMed Central

Hoad, C.L.; Parker, H.; Hudders, N.; Costigan, C.; Cox, E.F.; Perkins, A.C.; Blackshaw, P.E.; Marciani, L.; Spiller, R.C.; Fox, M.R.; Gowland, P.A.

2015-01-01

MRI can assess multiple gastric functions without ionizing radiation. However, time consuming image acquisition and analysis of gastric volume data, plus confounding of gastric emptying measurements by gastric secretions mixed with the test meal have limited its use to research centres. This study presents an MRI acquisition protocol and analysis algorithm suitable for the clinical measurement of gastric volume and secretion volume. Reproducibility of gastric volume measurements was assessed using data from 10 healthy volunteers following a liquid test meal with rapid MRI acquisition within one breath-hold and semi-automated analysis. Dilution of the ingested meal with gastric secretion was estimated using a respiratory-triggered T1 mapping protocol. Accuracy of the secretion volume measurements was assessed using data from 24 healthy volunteers following a mixed (liquid/solid) test meal with MRI meal volumes compared to data acquired using gamma scintigraphy (GS) on the same subjects studied on a separate study day. The mean (SD) coefficient of variance between 3 observers for both total gastric contents (including meal, secretions and air) and just the gastric contents (meal and secretion only) was 3 (2) % at large gastric volumes (> 200 ml). Mean (SD) secretion volumes post meal ingestion were 64 (51) ml and 110 (40) ml at 15 and 75 minutes respectively. Comparison with GS meal volumes, showed that MRI meal only volume (after correction for secretion volume) were similar to GS, with a linear regression gradient (std err) of 1.06 (0.10) and intercept −11 (24) ml. In conclusion, (i) rapid acquisition removed the requirement to image during prolonged breath-hold (ii) semi-automatic analysis greatly reduced time required to derive measurements and (iii) correction for secretion volumes provides accurate assessment of gastric meal volumes and emptying. Together these features provide the scientific basis of a protocol which would be suitable in clinical practice. PMID:25592405

Adipose stem cells can secrete angiogenic factors that inhibit hyaline cartilage regeneration.

PubMed

Lee, Christopher Sd; Burnsed, Olivia A; Raghuram, Vineeth; Kalisvaart, Jonathan; Boyan, Barbara D; Schwartz, Zvi

2012-08-24

Adipose stem cells (ASCs) secrete many trophic factors that can stimulate tissue repair, including angiogenic factors, but little is known about how ASCs and their secreted factors influence cartilage regeneration. Therefore, the aim of this study was to determine the effects ASC-secreted factors have in repairing chondral defects. ASCs isolated from male Sprague Dawley rats were cultured in monolayer or alginate microbeads supplemented with growth (GM) or chondrogenic medium (CM). Subsequent co-culture, conditioned media, and in vivo cartilage defect studies were performed. ASC monolayers and microbeads cultured in CM had decreased FGF-2 gene expression and VEGF-A secretion compared to ASCs cultured in GM. Chondrocytes co-cultured with GM-cultured ASCs for 7 days had decreased mRNAs for col2, comp, and runx2. Chondrocytes treated for 12 or 24 hours with conditioned medium from GM-cultured ASCs had reduced sox9, acan, and col2 mRNAs; reduced proliferation and proteoglycan synthesis; and increased apoptosis. ASC-conditioned medium also increased endothelial cell tube lengthening whereas conditioned medium from CM-cultured ASCs had no effect. Treating ASCs with CM reduced or abolished these deleterious effects while adding a neutralizing antibody for VEGF-A eliminated ASC-conditioned medium induced chondrocyte apoptosis and restored proteoglycan synthesis. FGF-2 also mitigated the deleterious effects VEGF-A had on chondrocyte apoptosis and phenotype. When GM-grown ASC pellets were implanted in 1 mm non-critical hyaline cartilage defects in vivo, cartilage regeneration was inhibited as evaluated by radiographic and equilibrium partitioning of an ionic contrast agent via microCT imaging. Histology revealed that defects with GM-cultured ASCs had no tissue ingrowth from the edges of the defect whereas empty defects and defects with CM-grown ASCs had similar amounts of neocartilage formation. ASCs must be treated to reduce the secretion of VEGF-A and other factors that inhibit cartilage regeneration, which can significantly influence how ASCs are used for repairing hyaline cartilage.

Topical effects of frog "Rana ridibunda" skin secretions on wound healing and reduction of wound microbial load.

PubMed

Mashreghi, Mohammad; Rezazade Bazaz, Mahere; Mahdavi Shahri, Nasser; Asoodeh, Ahmad; Mashreghi, Mansour; Behnam Rassouli, Morteza; Golmohammadzadeh, Shiva

2013-02-13

Study of the interrelationships between human and the animals in their environment has always been a subject of interest and caused discoveries of the animal applications in medicine. From the latest century, these remedies called back in traditional medicine of Vietnam and South America and frog skin was used as a biological dressing and had good effects in healing wounds. Also, frog skin secretions have wound healing properties and reduce inflammation. In this study we applied these secretions in the form of ointment to investigate their healing activities. Skin secretions were extracted from Rana ridibunda to evaluate their effects on wound healing in mice. Secretion used as raw extract (RE) and ultrafiltrated extract, using a membrane with cutoff 10kDa as under 10kDa (U10E), was administrated as ointment every 48h on wound site. Control group was left without any treatment and also there was other group treated with ointment (O group) alone. On 2, 4 and 6 days post injury, animals were euthanized and images were taken for wound closure evaluation. Then wound locations were removed for histological assays. Also wound microbial load was examined. Observational parameters including wound closure and wound microbiology in experimental groups compared with the control and O groups have been studied. The results showed U10E group has better effects than RE, O and control groups. Histological parameters, including numbers of inflammatory and fibroblast cells and amount of collagen fibers, neovascularization, as well, represented greater degree of wound healing in U10E group compared with RE, O, and control groups. Our results showed that frog skin secretions were significantly effective in promoting wound healing process. The U10E extract from the frog R. ridibunda possesses a potent accelerating wound healing effect that promises good potential for clinical application in wound care. Further studies will be required to characterize special molecules encompassing healing properties. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Differential Activation of Diverse Glutathione Transferases of Clonorchis sinensis in Response to the Host Bile and Oxidative Stressors

PubMed Central

Bae, Young-An; Ahn, Do-Whan; Lee, Eung-Goo; Kim, Seon-Hee; Cai, Guo-Bin; Kang, Insug; Sohn, Woon-Mok; Kong, Yoon

2013-01-01

Background Clonorchis sinensis causes chronic cumulative infections in the human hepatobiliary tract and is intimately associated with cholangiocarcinoma. Approximately 35 million people are infected and 600 million people are at risk of infections worldwide. C. sinensis excretory-secretory products (ESP) constitute the first-line effector system affecting the host-parasite interrelationship by interacting with bile fluids and ductal epithelium. However, the secretory behavior of C. sinensis in an environment close to natural host conditions is unclear. C. sinensis differs from Fasciola hepatica in migration to, and maturation in, the hepatic bile duct, implying that protein profile of the ESP of these two trematodes might be different from each other. Methodology/Principal Findings We conducted systemic approaches to analyze the C. sinensis ESP proteome and the biological reactivity of C. sinensis glutathione transferases (GSTs), such as global expression patterns and induction profiles under oxidative stress and host bile. When we observed ex host excretion behavior of C. sinensis in the presence of 10% host bile, the global proteome pattern was not significantly altered, but the amount of secretory proteins was increased by approximately 3.5-fold. Bioactive molecules secreted by C. sinensis revealed universal/unique features in relation to its intraluminal hydrophobic residing niche. A total of 38 protein spots identified abundantly included enzymes involved in glucose metabolism (11 spots, 28.9%) and diverse-classes of glutathione transferases (GSTs; 10 spots, 26.3%). Cathepsin L/F (four spots, 10.5%) and transporter molecules (three spots, 7.9%) were also recognized. The universal secretory proteins found in other parasites, such as several enzymes involved in glucose metabolism and oxygen transporters, were commonly detected. C. sinensis secreted less cysteine proteases and fatty acid binding proteins compared to other tissue-invading or intravascular trematodes. Interestingly, secretion of a 28 kDa σ-class GST (Cs28σGST3) was significantly affected by the host bile, involving reduced secretion of the 28 kDa species and augmented secretion of Cs28σGST3-related high-molecular-weight 85 kDa protein. Oxidative stressors induced upregulated secretion of 28 kDa Cs28σGST3, but not an 85 kDa species. A secretory 26 kDa μ-class GST (Cs26μGST2) was increased upon treatment with oxidative stressors and bile juice, while another 28 kDa σ-class GST (Cs28σGST1) showed negligible responses. Conclusions/Significance Our results represent the first analysis of the genuine nature of the C. sinensis ESP proteome in the presence of host bile mimicking the natural host environments. The behavioral patterns of migration and maturation of C. sinensis in the bile ducts might contribute to the secretion of copious amounts of diverse GSTs, but a smaller quantity and fewer kinds of cysteine proteases. The Cs28σGST1 and its paralog(s) detoxify endogenous oxidative molecules, while Cs28σGST3 and Cs26μGST2 conjugate xenobiotics/hydrophobic substances in the extracellular environments, which imply that diverse C. sinensis GSTs might have evolved for each of the multiple specialized functions. PMID:23696907

Hyperthyroidism secondary to a pituitary adenoma secreting TSH, FSH, alpha-subunit and GH.

PubMed

Patrick, A W; Atkin, S L; MacKenzie, J; Foy, P M; White, M C; MacFarlane, I A

1994-02-01

A 51-year-old man had been treated for hyperthyroidism with antithyroid drugs for 8 years. He was then found to have a large pituitary adenoma with biochemical evidence of overproduction of TSH, FSH and alpha-subunit. Subsequent immunocytochemical and tissue culture studies confirmed secretion of these hormones. In addition, the tumour stained for GH and was capable of GH production in vitro. This combination of hormones produced by a pituitary adenoma has not been previously reported.

Monocyte-derived macrophages from Crohn's disease patients are impaired in the ability to control intracellular adherent-invasive Escherichia coli and exhibit disordered cytokine secretion profile.

PubMed

Vazeille, Emilie; Buisson, Anthony; Bringer, Marie-Agnès; Goutte, Marion; Ouchchane, Lemlih; Hugot, Jean-Pierre; de Vallée, Amélie; Barnich, Nicolas; Bommelaer, Gilles; Darfeuille-Michaud, Arlette

2015-05-01

Ileal lesions of Crohn's disease [CD] patients are colonised by adherent-invasive Escherichia coli [AIEC] able to survive in macrophage cell lines. We analysed the ability of monocyte-derived macrophages [MDM] from CD patients to control AIEC intracellular replication and the pro-inflammatory cytokine response of the infected-MDM. Peripheral blood MDM were obtained from 24 CD genotyped for NOD2 and ATG16L1 mutations, 5 ulcerative colitis [UC] patients and 12 healthy controls [HC]. The numbers of intracellular bacteria were determined using gentamicin assay. Cytokine secretion was quantified by ELISA assay. We observed that higher levels of bacteria were internalised within MDM from CD patients than MDM from HC or UC patients. MDM from CD patients were unable to restrict AIEC intracellular replication. Infection of MDM from CD patients with AIEC resulted in significantly increased secretion of IL-6 and tumour necrosis factor alpha [TNF α] than did infection with non-pathogenic E. coli. AIEC-infected MDM from CD patients exhibited a disordered cytokines secretion compared with MDM from UC patients and HC. AIEC-infected MDM from patients with quiescent CD released significantly higher amounts of IL-6 and TNF-alpha than those with active disease or those from HC. The level of secreted TNF-alpha was correlated to the number of intracellular AIEC in MDM from CD patients. Treatment of MDM with infliximab did not change the MDM behaviour. MDM from CD patients are unable to restrict intracellular AIEC replication, leading to disordered inflammatory response influenced by disease activity. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Effects of dexamethasone and insulin on the synthesis of triacylglycerols and phosphatidylcholine and the secretion of very-low-density lipoproteins and lysophosphatidylcholine by monolayer cultures of rat hepatocytes.

PubMed Central

Mangiapane, E H; Brindley, D N

1986-01-01

Rat hepatocytes in monolayer culture were preincubated for 19 h with 1 microM-dexamethasone, and the incubation was continued for a further 23 h with [14C]oleate, [3H]glycerol and 1 microM-dexamethasone. Dexamethasone increased the secretion of triacylglycerol into the medium in particles that had the properties of very-low-density lipoproteins. The increased secretion was matched by a decrease in the triacylglycerol and phosphatidylcholine that remained in the hepatocytes. Preincubating the hepatocytes for the total 42 h period with 36 nM-insulin decreased the amount of triacylglycerol in the medium and in the cells after the final incubation for 23 h with radioactive substrates. However, insulin had no significant effect on the triacylglycerol content of the cell and medium when it was present only in the final 23 h incubation. Insulin antagonized the effects of dexamethasone in stimulating the secretion of triacylglycerol from the hepatocytes, especially when it was present throughout the total 42 h period. The labelling of lysophosphatidylcholine in the medium when hepatocytes were incubated with [14C]oleate and [3H]glycerol was greater than that of phosphatidylcholine. The appearance of this lipid in the medium, unlike that of triacylglycerol and phosphatidylcholine, was not stimulated by dexamethasone, or inhibited by colchicine. However, the presence of lysophosphatidylcholine in the medium was decreased when the hepatocytes were incubated with both dexamethasone and insulin. These findings are discussed in relation to the control of the synthesis of glycerolipids and the secretion of very-low-density lipoproteins and lysophosphatidylcholine by the liver, particularly in relation to the interactions of glucocorticoids and insulin. PMID:3513755

Effects of phosphoramidon and pepstatin A on the secretion of endothelin-1 and big endothelin-1 by human umbilical vein endothelial cells: measurement by two-site enzyme-linked immunosorbent assays.

PubMed

Plumpton, C; Kalinka, S; Martin, R C; Horton, J K; Davenport, A P

1994-08-01

1. Two-site enzyme-linked immunosorbent assays have been developed for the rapid, sensitive and non-isotopic measurement of endothelin-1 and big endothelin-1. The sensitivities of detection were 0.5 and 0.3 fmol/well, with ED50 values of 13 and 12 fmol/well for the endothelin-1 and big endothelin-1 assays, respectively. Each assay is highly selective for its corresponding antigen. The ET-1 assay showed no detectable cross-reactivity with ET-1-(1-20), indicating that the assay only recognizes the 21-amino acid biologically active peptide. 2. The two assays were used to measure the effects of two classes of protease inhibitor on the basal release of enothelin-1 and big endothelin-1 from cultured first-passage human umbilical vein endothelial cells. 3. The secretion of both peptides was time-dependent over 12 h. The metalloprotease inhibitor phosphoramidon (1 x 10(-4) mol/l) significantly reduced the amount of endothelin-1 secreted into the medium (P < 0.05), with a concomitant increase in the secreted levels of big endothelin-1 (P < 0.01). The aspartyl protease inhibitor, pepstatin A, also caused a significant decrease in the secretion of endothelin (P < 0.05). However, unlike phosphoramidon, there was no increase in the levels of big ET-1 compared with the controls. At these concentrations, neither inhibitor affected the viability of the cells as indicated by Trypan Blue exclusion. 4. The two assays permit the direct measurement of endothelin-1 and its precursor, and will be of use in the elucidation of the putative human endothelin-converting enzyme(s).(ABSTRACT TRUNCATED AT 250 WORDS)

Compound heterozygous mutations (p.Leu13Pro and p.Tyr294*) associated with factor VII deficiency cause impaired secretion through ineffective translocation and extensive intracellular degradation of factor VII.

PubMed

Suzuki, Keijiro; Sugawara, Takeshi; Ishida, Yoji; Suwabe, Akira

2013-02-01

Congenital coagulation factor VII (FVII) deficiency is a rare coagulation disease. We investigated the molecular mechanisms of this FVII deficiency in a patient with compound heterozygous mutations. A 22-year-old Japanese female was diagnosed with asymptomatic FVII deficiency. The FVII activity and antigen were greatly reduced (activity, 13.0%; antigen, 10.8%). We analyzed the F7 gene of this patient and characterized mutant FVII proteins using in vitro expression studies. Sequence analysis revealed that the patient was compound heterozygous with a point mutation (p.Leu13Pro) in the central hydrophobic core of the signal peptides and a novel non-sense mutation (p.Tyr294*) in the catalytic domain. Expression studies revealed that mutant FVII with p.Leu13Pro (FVII13P) showed less accumulation in the cells (17.5%) and less secretion into the medium (64.8%) than wild type showed. Truncated FVII resulting from p.Tyr294* (FVII294X) was also decreased in the cells (32.0%), but was not secreted into the medium. Pulse-chase experiments revealed that both mutants were extensively degraded intracellularly compared to wild type. The majority of FVII13P cannot translocate into endoplasmic reticulum (ER). However, a small amount of FVII13P was processed normally with post-translational modifications and was secreted into the medium. The fact that FVII294X was observed only in ER suggests that it is retained in ER. Proteasome apparently plays a central role in these degradations. These findings demonstrate that both mutant FVIIs impaired secretion through ineffective translocation to and retention in ER with extensive intracellular degradation, resulting in an insufficient phenotype. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fluoride Induces Endoplasmic Reticulum Stress and Inhibits Protein Synthesis and Secretion

PubMed Central

Sharma, Ramaswamy; Tsuchiya, Masahiro; Bartlett, John D.

2008-01-01

Background Exposure to excessive amounts of fluoride (F−) causes dental fluorosis in susceptible individuals; however, the mechanism of F−-induced toxicity is unclear. Previously, we have shown that high-dose F− activates the unfolded protein response (UPR) in ameloblasts that are responsible for dental enamel formation. The UPR is a signaling pathway responsible for either alleviating endoplasmic reticulum (ER) stress or for inducing apoptosis of the stressed cells. Objectives In this study we determined if low-dose F− causes ER stress and activates the UPR, and we also determined whether F− interferes with the secretion of proteins from the ER. Methods We stably transfected the ameloblast-derived LS8 cell line with secreted alkaline phosphatase (SEAP) and determined activity and localization of SEAP and F−-mediated induction of UPR proteins. Also, incisors from mice given drinking water containing various concentrations of F− were examined for eucaryotic initiation factor-2, subunit alpha (eIF2α) phosphorylation. Results We found that F− decreases the extracellular secretion of SEAP in a linear, dose-dependent manner. We also found a corresponding increase in the intracellular accumulation of SEAP after exposure to F−. These changes are associated with the induction of UPR proteins such as the molecular chaperone BiP and phosphorylation of the UPR sensor PKR-like ER kinase, and its substrate, eIF2α. Importantly, F−-induced phosphorylation of eIF2αwas confirmed in vivo. Conclusions These data suggest that F− initiates an ER stress response in ameloblasts that interferes with protein synthesis and secretion. Consequently, ameloblast function during enamel development may be impaired, and this may culminate in dental fluorosis. PMID:18795154

Effects of agmatine on secretion of interferon tau and catecholamines and expression of genes related to production of polyamines by ovine trophectoderm cells.

PubMed

Lenis, Yasser Y; Wang, Xiaoqiu; Tang, Wanjin; Wu, Guoyao; Bazer, Fuller W

2016-10-01

Embryonic survival requires histotrophic nutrition, including molecules secreted or transported into the uterine lumen by uterine epithelia. L-Arginine (Arg) is a common substrate for synthesis of nitric oxide, ornithine, proline, glutamate, creatinine, urea, polyamines and agmatine. Agmatine (Agm) is a product of arginine decarboxylation and it is a substrate for agmatinase for synthesis of putrescine and other polyamines in the ovine conceptus. Polyamines are essential for conceptus development. Therefore, this study compared effects of Arg and Agm on the behavior of ovine trophectoderm (oTr1) cells cultured in vitro. Arg, but not Agm, increased proliferation and migration of oTr1 cells, but neither Arg nor Agm affected cell adhesion. The total amount of IFNT in culture medium of oTr1 cells was increased by Arg, but Agm increased the IFNT production per oTr1 cell. Arg and Agm plus Arg decreased secretion of dopamine and norepinephrine by oTr1 cells. Agm upregulates expression of mRNAs SLC7A1, agmatinase and OAZ2 while the combination of Arg and Agm decreased expression of mRNAs for ODC1, SLC7A1, OAZ1 and OAZ3 by oTr1 cells. Although Agm does not stimulate proliferation, migration or adhesion of oTr1 cells or their secretion of catecholamines, Agm did increase transcription of SLC7A1, agmatinase and OAZ2 genes which would increase the capacity of oTr1 cells to produce polyamines. Collectively, our findings suggest a role for Arg and Agm in the regulation of transport of basic amino acids (including Arg), polyamine synthesis, and secretion of catecholamines by oTr1 cells.

Regulation of MMP-3 expression and secretion by the chemokine eotaxin-1 in human chondrocytes.

PubMed

Chao, Pin-Zhir; Hsieh, Ming-Shium; Cheng, Chao-Wen; Lin, Yung-Feng; Chen, Chien-Ho

2011-11-25

Osteoarthritis (OA) is characterized by the degradation of articular cartilage, marked by the breakdown of matrix proteins. Studies demonstrated the involvement of chemokines in this process, and some may potentially serve as diagnostic markers and therapeutic targets; however, the underlying signal transductions are not well understood. We investigated the effects of the CC chemokine eotaxin-1 (CCL11) on the matrix metalloproteinase (MMP) expression and secretion in the human chondrocyte cell line SW1353 and primary chondrocytes. Eotaxin-1 significantly induced MMP-3 mRNA expression in a dose-dependent manner. Inhibitors of extracellular signal-regulated kinase (ERK) and p38 kinase were able to repress eotaxin-1-induced MMP-3 expression. On the contrary, Rp-adenosine-3',5'-cyclic monophosphorothioate (Rp-cAMPs), a competitive cAMP antagonist for cAMP receptors, and H-89, a protein kinase A (PKA) inhibitor, markedly enhanced eotaxin-1-induced MMP-3 expression. These results suggest that MMP-3 expression is specifically mediated by the G protein-coupled eotaxin-1 receptor activities. Interestingly, little amount of MMP-3 protein was detected in the cell lysates of eotaxin-1-treated SW1353 cells, and most of MMP-3 protein was in the culture media. Furthermore we found that the eotaxin-1-dependent MMP-3 protein secretion was regulated by phospholipase C (PLC)-protein kinase C (PKC) cascade and c-Jun N-terminal kinase (JNK)/mitogen-activated protein (MAP) kinase pathways. These data indicate a specific regulation of MMP-3 secretion also by eotaxin-1 receptor activities. Eotaxin-1 not only induces MMP-3 gene expression but also promotes MMP-3 protein secretion through G protein-coupled eotaxin-1 receptor activities. Chemokines, such as eotaxin-1, could be a potential candidate in the diagnosis and treatment of arthritis.

Influence of multilayer rhBMP-2 DNA coating on the proliferation and differentiation of MC3T3-E1 cells seeded on roughed titanium surface.

PubMed

Jiang, Qiao-Hong; Liu, Li; Shen, Jian-Wei; Peel, Sean; Yang, Guo-Li; Zhao, Shi-Fang; He, Fu-Ming

2012-10-01

For bone morphogenetic protein (BMP) gene therapy to be a viable approach for enhancing implant osseointegration clinically, requires the development of efficient nonviral delivery vectors that can coat the implant. This study evaluated a multilayer cationic liposome-DNA complex (LDc) coating as a delivery vehicle for recombinant human BMP-2 (rhBMP-2). Multilayered coatings, comprising hyaluronic acid (HA) and LDc, were fabricated onto titanium using a layer-by-layer (LBL) assembly technique. Preosteoblastic MC3T3-E1 cells were cultured on the roughened titanium surfaces coated with multilayers of HA/LDc, or on uncoated or HA/liposome only surfaces as controls. The amount of rhBMP-2 secreted by the MC3T3-E1 cells and the effect of the various surfaces on cell viability, proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion, and calcium deposition were evaluated. Messenger RNA levels of OC, ALP, Runx2, and Osx were also investigated. The results demonstrated that rhBMP-2 protein secreted into culture medium at 3 days was significantly higher than control groups. MC3T3-E1 cells cultured on the HA/LDc coating displayed significantly higher ALP activity and OC secretion at 7 days and 14 days culture, respectively. MC3T3-E1 cells cultured on HA/LDc upregulated expression of the osteoblast differentiation markers, especially on days 12 for OC and on days 6 and 12 for ALP and Osx. In conclusion, MC3T3-E1 cell cultured on the multilayer HA/LDc coating surface can secret rhBMP-2 protein and the protein levels were effective in inducing early osteogenic differentiation. Copyright © 2012 Wiley Periodicals, Inc.

Haemophilus ducreyi infection induces activation of the NLRP3 inflammasome in nonpolarized but not in polarized human macrophages.

PubMed

Li, Wei; Katz, Barry P; Bauer, Margaret E; Spinola, Stanley M

2013-08-01

Recognition of microbial infection by certain intracellular pattern recognition receptors leads to the formation of a multiprotein complex termed the inflammasome. Inflammasome assembly activates caspase-1 and leads to cleavage and secretion of the proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-18, which help control many bacterial pathogens. However, excessive inflammation mediated by inflammasome activation can also contribute to immunopathology. Here, we investigated whether Haemophilus ducreyi, a Gram-negative bacterium that causes the genital ulcer disease chancroid, activates inflammasomes in experimentally infected human skin and in monocyte-derived macrophages (MDM). Although H. ducreyi is predominantly extracellular during human infection, several inflammasome-related components were transcriptionally upregulated in H. ducreyi-infected skin. Infection of MDM with live, but not heat-killed, H. ducreyi induced caspase-1- and caspase-5-dependent processing and secretion of IL-1β. Blockage of H. ducreyi uptake by cytochalasin D significantly reduced the amount of secreted IL-1β. Knocking down the expression of the inflammasome components NLRP3 and ASC abolished IL-1β production. Consistent with NLRP3-dependent inflammasome activation, blocking ATP signaling, K(+) efflux, cathepsin B activity, and lysosomal acidification all inhibited IL-1β secretion. However, inhibition of the production and function of reactive oxygen species did not decrease IL-1β production. Polarization of macrophages to classically activated M1 or alternatively activated M2 cells abrogated IL-1β secretion elicited by H. ducreyi. Our study data indicate that H. ducreyi induces NLRP3 inflammasome activation via multiple mechanisms and suggest that the heterogeneity of macrophages within human lesions may modulate inflammasome activation during human infection.

Reduced IL-10 Production in Fetal Type II Epithelial Cells Exposed to Mechanical Stretch Is Mediated via Activation of IL-6-SOCS3 Signaling Pathway

PubMed Central

Hawwa, Renda L.; Huang, Zheping; Sharma, Surendra; Sanchez-Esteban, Juan

2013-01-01

An imbalance between pro-inflammatory and anti-inflammatory cytokines is a key factor in the lung injury of premature infants exposed to mechanical ventilation. Previous studies have shown that lung cells exposed to stretch produces reduced amounts of the anti-inflammatory cytokine IL-10. The objective of these studies was to analyze the signaling mechanisms responsible for the decreased IL-10 production in fetal type II cells exposed to mechanical stretch. Fetal mouse type II epithelial cells isolated at embryonic day 18 were exposed to 20% stretch to simulate lung injury. We show that IL-10 receptor gene expression increased with gestational age. Mechanical stretch decreased not only IL-10 receptor gene expression but also IL-10 secretion. In contrast, mechanical stretch increased release of IL-6. We then investigated IL-10 signaling pathway-associated proteins and found that in wild-type cells, mechanical stretch decreased activation of JAK1 and TYK2 and increased STAT3 and SOCS3 activation. However, opposite effects were found in cells isolated from IL-10 knockout mice. Reduction in IL-6 secretion by stretch was observed in cells isolated from IL-10 null mice. To support the idea that stretch-induced SOCS3 expression via IL-6 leads to reduced IL-10 expression, siRNA-mediated inhibition of SOCS3 restored IL-10 secretion in cells exposed to stretch and decreased IL-6 secretion. Taken together, these studies suggest that the inhibitory effect of mechanical stretch on IL-10 secretion is mediated via activation of IL-6-STAT3-SOCS3 signaling pathway. SOCS3 could be a therapeutic target to increase IL-10 production in lung cells exposed to mechanical injury. PMID:23527226

Reduced IL-10 production in fetal type II epithelial cells exposed to mechanical stretch is mediated via activation of IL-6-SOCS3 signaling pathway.

PubMed

Hokenson, Michael A; Wang, Yulian; Hawwa, Renda L; Huang, Zheping; Sharma, Surendra; Sanchez-Esteban, Juan

2013-01-01

An imbalance between pro-inflammatory and anti-inflammatory cytokines is a key factor in the lung injury of premature infants exposed to mechanical ventilation. Previous studies have shown that lung cells exposed to stretch produces reduced amounts of the anti-inflammatory cytokine IL-10. The objective of these studies was to analyze the signaling mechanisms responsible for the decreased IL-10 production in fetal type II cells exposed to mechanical stretch. Fetal mouse type II epithelial cells isolated at embryonic day 18 were exposed to 20% stretch to simulate lung injury. We show that IL-10 receptor gene expression increased with gestational age. Mechanical stretch decreased not only IL-10 receptor gene expression but also IL-10 secretion. In contrast, mechanical stretch increased release of IL-6. We then investigated IL-10 signaling pathway-associated proteins and found that in wild-type cells, mechanical stretch decreased activation of JAK1 and TYK2 and increased STAT3 and SOCS3 activation. However, opposite effects were found in cells isolated from IL-10 knockout mice. Reduction in IL-6 secretion by stretch was observed in cells isolated from IL-10 null mice. To support the idea that stretch-induced SOCS3 expression via IL-6 leads to reduced IL-10 expression, siRNA-mediated inhibition of SOCS3 restored IL-10 secretion in cells exposed to stretch and decreased IL-6 secretion. Taken together, these studies suggest that the inhibitory effect of mechanical stretch on IL-10 secretion is mediated via activation of IL-6-STAT3-SOCS3 signaling pathway. SOCS3 could be a therapeutic target to increase IL-10 production in lung cells exposed to mechanical injury.

The MCT4 Gene: A Novel, Potential Target for Therapy of Advanced Prostate Cancer.

PubMed

Choi, Stephen Yiu Chuen; Xue, Hui; Wu, Rebecca; Fazli, Ladan; Lin, Dong; Collins, Colin C; Gleave, Martin E; Gout, Peter W; Wang, Yuzhuo

2016-06-01

The management of castration-resistant prostate cancer (CRPC) is a major challenge in the clinic. Androgen receptor signaling-directed strategies are not curative in CRPC therapy, and new strategies targeting alternative, key cancer properties are needed. Using reprogrammed glucose metabolism (aerobic glycolysis), cancer cells typically secrete excessive amounts of lactic acid into their microenvironment, promoting cancer development, survival, and progression. Cellular lactic acid secretion is thought to be predominantly mediated by MCT4, a plasma membrane transporter protein. As such, the MCT4 gene provides a unique, potential therapeutic target for cancer. A tissue microarray of various Gleason grade human prostate cancers was stained for MCT4 protein. Specific, MCT4-targeting antisense oligonucleotides (MCT4 ASO) were designed and candidate MCT4 ASOs checked for effects on (i) MCT4 expression, lactic acid secretion/content, glucose consumption, glycolytic gene expression, and proliferation of human CRPC cells and (ii) growth of PC-3 tumors in nude mice. Elevated MCT4 expression was associated with human CRPC and an earlier time to relapse. The treatment of PC-3, DU145, and C4-2 CRPC cultures with candidate MCT4 ASOs led to marked inhibition of MCT4 expression, lactic acid secretion, to increased intracellular lactic acid levels, and markedly reduced aerobic glycolysis and cell proliferation. Treatment of PC-3 tumor-bearing nude mice with the MCT4 ASOs markedly inhibited tumor growth without inducing major host toxicity. MCT4-targeting ASOs that inhibit lactic acid secretion may be useful for therapy of CRPC and other cancers, as they can interfere with reprogrammed energy metabolism of cancers, an emerging hallmark of cancer. Clin Cancer Res; 22(11); 2721-33. ©2016 AACR. ©2016 American Association for Cancer Research.

Immunity to Trichinella spiralis infection in vitamin A-deficient mice

PubMed Central

1992-01-01

Vitamin A-deficient (A-) mice make strikingly poor IgG responses when they are immunized with purified protein antigens. Previously, we showed that A- T cells overproduce interferon gamma (IFN-gamma), which then could inhibit interleukin 4 (IL-4)-stimulated B cell IgG responses. To determine if the altered IFN-gamma regulation pattern and its immunological consequences would extend to a natural infection, we studied mice infected with the parasitic helminth Trichinella spiralis. The course of the infection was similar in A- and A-sufficient (A+) mice. These mice did not differ with respect to newborn larvae/female/hour produced in the intestine, or muscle larvae burden 5 wk postinfection. They also did not differ in the intestinal worm expulsion rate until day 15, when A- mice still harbored parasites, whereas A+ mice had cleared intestinal worms. Vitamin A deficiency reduced both the frequency of B lymphocytes secreting IgG1 antibodies to parasite antigens, and the bone marrow eosinophilia associated with helminth infection. The cytokine secretion patterns in infected mice were consistent with these observations and with previous studies. Mesenteric lymph node cells from infected A- mice secreted significantly more IFN-gamma, and significantly less IL-2, IL-4, and IL- 5 than infected A+ controls. A- splenocytes secreted significantly more IFN-gamma, and equivalent amounts of IL-2, IL-4, and IL-5 compared with A+ controls. Interestingly, CD4-CD8- cells secreted the majority of the IL-4 produced in the spleen. The IL-2, IL-4, and IL-5 steady-state transcript levels correlated with secreted protein levels, but IFN- gamma transcripts did not. Although they secreted more protein, A- cells contained fewer IFN-gamma transcripts than A+ cells. These results suggest two vitamin A-mediated regulation steps in IFN-gamma gene expression: positive regulation of IFN-gamma transcript levels, and negative regulation posttranscriptionally. The essentially unaltered outcome of T. spiralis infection in vitamin A-deficient mice probably reflects a balance between cellular and humoral responses. The IFN-gamma overproduction might have a positive effect on the gut inflammatory response, but the decrease eosinophilia, cytokine production in mesenteric lymph node, and IgG1-secreting cell frequency might have a negative effect on T. spiralis immunity. PMID:1730911

Role of leptin in female reproduction.

PubMed

Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Maymó, Julieta; Dueñas, José L; Varone, Cecilia; Sánchez-Margalet, Víctor

2015-01-01

Reproductive function is dependent on energy resources. The role of weight, body composition, fat distribution and the effect of diet have been largely investigated in experimental female animals as well as in women. Any alteration in diet and/or weight may induce abnormalities in timing of sexual maturation and fertility. However, the cellular mechanisms involved in the fine coordination of energy balance and reproduction are largely unknown. The brain and hypothalamic structures receive endocrine and/or metabolic signals providing information on the nutritional status and the degree of fat stores. Adipose tissue acts both as a store of energy and as an active endocrine organ, secreting a large number of biologically important molecules termed adipokines. Adipokines have been shown to be involved in regulation of the reproductive functions. The first adipokine described was leptin. Extensive research over the last 10 years has shown that leptin is not only an adipose tissue-derived messenger of the amount of energy stores to the brain, but also a crucial hormone/cytokine for a number of diverse physiological processes, such as inflammation, angiogenesis, hematopoiesis, immune function, and most importantly, reproduction. Leptin plays an integral role in the normal physiology of the reproductive system with complex interactions at all levels of the hypothalamic-pituitary gonadal (HPG) axis. In addition, leptin is also produced by placenta, where it plays an important autocrine function. Observational studies have demonstrated that states of leptin excess, deficiency, or resistance can be associated with abnormal reproductive function. This review focuses on the leptin action in female reproduction.

Diterpene composition of defense secretion of four west AfricanTrinervitermes soldiers.

PubMed

Braekman, J C; Daloze, D; Dupont, A; Pasteels, J M; Josens, G

1984-09-01

The diterpene composition of the defensive secretions of minor and major soldiers is described for four sympatricTrinervitermes from the Ivory Coast. The degree of intra- and interspecific similarity between the secretions is assessed and related to available information on soldier behavior. A significant chemical dimorphism is observed between minor and major soldiers ofT. geminatus andT. togoensis. Both species build extensive foraging trails in the open air. During these excursions, the workers are protected by numerous minor soldiers, but only a few major ones. Internest comparison inT. geminatus suggests that the differences between minor and major soldiers is as large within a nest as between different nests. By, contrast, inT. trinervius andT. oeconomus both types of soldiers produce very similar secretions. The foraging habits of those species are far more cryptic. The first species builds earthen tunnels, and the second one forages in close proximity to its nest under cover of vegetation.

Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins

NASA Astrophysics Data System (ADS)

Petrone, Luigi; Kumar, Akshita; Sutanto, Clarinda N.; Patil, Navinkumar J.; Kannan, Srinivasaraghavan; Palaniappan, Alagappan; Amini, Shahrouz; Zappone, Bruno; Verma, Chandra; Miserez, Ali

2015-10-01

Interfacial water constitutes a formidable barrier to strong surface bonding, hampering the development of water-resistant synthetic adhesives. Notwithstanding this obstacle, the Asian green mussel Perna viridis attaches firmly to underwater surfaces via a proteinaceous secretion (byssus). Extending beyond the currently known design principles of mussel adhesion, here we elucidate the precise time-regulated secretion of P. viridis mussel adhesive proteins. The vanguard 3,4-dihydroxy-L-phenylalanine (Dopa)-rich protein Pvfp-5 acts as an adhesive primer, overcoming repulsive hydration forces by displacing surface-bound water and generating strong surface adhesion. Using homology modelling and molecular dynamics simulations, we find that all mussel adhesive proteins are largely unordered, with Pvfp-5 adopting a disordered structure and elongated conformation whereby all Dopa residues reside on the protein surface. Time-regulated secretion and structural disorder of mussel adhesive proteins appear essential for optimizing extended nonspecific surface interactions and byssus' assembly. Our findings reveal molecular-scale principles to help the development of wet-resistant adhesives.

Boron modulates extracellular matrix and TNF alpha synthesis in human fibroblasts.

PubMed

Benderdour, M; Hess, K; Dzondo-Gadet, M; Nabet, P; Belleville, F; Dousset, B

1998-05-29

Boric acid was not mitogenic for human fibroblasts and it did not change cell viability until 0.5% (w/v). Boric acid treatment affected the metabolism of human dermal fibroblasts in culture, decreasing the synthesis of extracellular matrix macromolecules such as proteoglycans, collagen, and total proteins. It also increased the release of these molecules into the culture medium. The principal proteins secreted into the medium after boric acid treatment had molecular masses of 90, 70, 58, 49, and 43 kDa and faint bands were detected by electrophoresis between 14 and 30 kDa. hsp 70 and TNF alpha were detected among the secreted proteins by immunoblotting, and the amount of TNF alpha released was quantified by radioimmunoassay. Total mRNA levels were higher after boric acid treatment and peaked after 6 h of treatment. TNF alpha mRNA was undetectable in unstimulated fibroblasts and two TNF alpha mRNA bands were detected after stimulation: immature mRNA (4.8 kb) and mature TNF alpha mRNA (1.9 kb). Thus, the effects of boric acid observed in wound repair in vivo may be due to TNF alpha synthesis and secretion.

Oxalate contributes to the resistance of Gaillardia grandiflora and Lupinus sericeus to a phytotoxin produced by Centaurea maculosa.

PubMed

Weir, Tiffany L; Bais, Harsh Pal; Stull, Valerie J; Callaway, Ragan M; Thelen, Giles C; Ridenour, Wendy M; Bhamidi, Suresh; Stermitz, Frank R; Vivanco, Jorge M

2006-03-01

Centaurea maculosa Lam. is a noxious weed in western North America that produces a phytotoxin, (+/-)-catechin, which is thought to contribute to its invasiveness. Areas invaded by C. maculosa often result in monocultures of the weed, however; in some areas, North American natives stand their ground against C. maculosa and show varying degrees of resistance to its phytotoxin. Two of these resistant native species, Lupinus sericeus Pursh and Gaillardia grandiflora Van Houtte, were found to secrete increased amounts of oxalate in response to catechin exposure. Mechanistically, we found that oxalate works exogenously by blocking generation of reactive oxygen species in susceptible plants and reducing oxidative damage generated in response to catechin. Furthermore, field experiments show that L. sericeus indirectly facilitates native grasses in grasslands invaded by C. maculosa, and this facilitation can be correlated with the presence of oxalate in soil. Addition of exogenous oxalate to native grasses and Arabidopsis thaliana (L.) Heynh grown in vitro alleviated the phytotoxic effects of catechin, supporting the field experiments and suggesting that root-secreted oxalate may also act as a chemical facilitator for plant species that do not secrete the compound.

Identification of the catalytic triad of the lipase/acyltransferase from Aeromonas hydrophila.

PubMed Central

Brumlik, M J; Buckley, J T

1996-01-01

Aeromonas hydrophila secretes a lipolytic enzyme that has several properties in common with the mammalian enzyme lecithin-cholesterol acyltransferase. We have recently shown that it is a member of a newly described group of proteins that contain five similar blocks of sequence arranged in the same order in their primary structures (C. Upton and J. T. Buckley, Trends Biochem. Sci. 233:178-179, 1995). Assuming that, like other lipases, these enzymes have a Ser-Asp-His catalytic triad, we used these blocks to predict which aspartic acid and histidine would be at the active site of the Aeromonas enzyme. Targeted residues were replaced with other amino acids by site-directed mutagenesis, and the effects on secretion and activity were assessed. Changing His-291 to asparagine completely abolished enzyme activity, although secretion by the bacteria was not affected. Only very small amounts of the D116N mutant appeared in the culture supernatant, likely because it is sensitive to periplasmic proteases it encounters en route. Assays of crude preparations containing this variant showed no detectable enzyme activity. We conclude that, together with Ser-16, which we have identified previously, Asp-116 and His-291 compose the catalytic triad of the enzyme. PMID:8606184

Post-secretory fate of host defence components in mucus.

PubMed

Salathe, Matthias; Forteza, Rosanna; Conner, Gregory E

2002-01-01

Airway mucus is a complex mixture of secretory products that provide a multifaceted defence against infection. Among many antimicrobial substances, mucus contains a peroxidase identical to milk lactoperoxidase (LPO) that is produced by goblet cells and submucosal glands. Airway secretions contain the substrates for LPO, namely thiocyanate and hydrogen peroxide, at concentrations sufficient for production of the biocidal compound hypothiocyanite, a fact confirmed by us in vitro. In vivo, inhibition of airway LPO in sheep significantly inhibits bacterial clearance, suggesting that the LPO system is a major contributor to host defences. Since secretory products including LPO are believed to be steadily removed by mucociliary clearance, their amount and availability on the surface is thought to be controlled solely by secretion. In contrast to this paradigm, new data suggest that LPO and other substances are retained at the ciliary border of the airway epithelium by binding to surface-associated hyaluronan, thereby providing an apical, fully active enzyme pool. Thus, hyaluronan, secreted from submucosal gland cells, plays a previously unrecognized pivotal role in mucosal host defence by retaining LPO and possibly other substances important for first line host defence at the apical surface 'ready for use' and protected from ciliary clearance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, B.A.; Easom, R.A.; Hughes, J.H.

Diacylglycerol accumulation has been examined in secretagogue-stimulated pancreatic islets with a newly developed negative ion chemical ionization mass spectrometric method. The muscarinic agonist carbachol induces islet accumulation of diacylglycerol rich in arachidonate and stearate, and a parallel accumulation of {sup 3}H-labeled diacylglycerol occurs in carbachol-stimulated islets that had been prelabeled with ({sup 3}H)glycerol. Islets so labeled do not accumulate {sup 3}H-labeled diacylglycerol in response to D-glucose, but D-glucose does induce islet accumulation of diacylglycerol by mass. This material is rich in palmitate and oleate and contains much smaller amounts of arachidonate. Neither secretagogue influences triacylglycerol labeling, and neither induces releasemore » of ({sup 3}H)choline or ({sup 3}H)phosphocholine from islets prelabeled with ({sup 3}H)choline. These observations indicate that the diacylglycerol that accumulates in islets in response to carbachol arises from hydrolysis of glycerolipids, probably including phosphoinositides. The bulk of the diacylglycerol which accumulates in response to glucose does not arise from glycerolipid hydrolysis and must therefore reflect de novo synthesis. The endogenous diacylglycerol which accumulates in secretagogue-stimulated islets may participate in insulin secretion because exogenous diacylglycerol induces insulin secretion from islets, and an inhibitor of diacylglycerol metabolism to phosphatidic acid augments glucose-induced insulin secretion.« less

In situ proteo-metabolomics reveals metabolite secretion by the acid mine drainage bio-indicator, Euglena mutabilis

PubMed Central

Halter, David; Goulhen-Chollet, Florence; Gallien, Sébastien; Casiot, Corinne; Hamelin, Jérôme; Gilard, Françoise; Heintz, Dimitri; Schaeffer, Christine; Carapito, Christine; Van Dorsselaer, Alain; Tcherkez, Guillaume; Arsène-Ploetze, Florence; Bertin, Philippe N

2012-01-01

Euglena mutabilis is a photosynthetic protist found in acidic aquatic environments such as peat bogs, volcanic lakes and acid mine drainages (AMDs). Through its photosynthetic metabolism, this protist is supposed to have an important role in primary production in such oligotrophic ecosystems. Nevertheless, the exact contribution of E. mutabilis in organic matter synthesis remains unclear and no evidence of metabolite secretion by this protist has been established so far. Here we combined in situ proteo-metabolomic approaches to determine the nature of the metabolites accumulated by this protist or potentially secreted into an AMD. Our results revealed that the secreted metabolites are represented by a large number of amino acids, polyamine compounds, urea and some sugars but no fatty acids, suggesting a selective organic matter contribution in this ecosystem. Such a production may have a crucial impact on the bacterial community present on the study site, as it has been suggested previously that prokaryotes transport and recycle in situ most of the metabolites secreted by E. mutabilis. Consequently, this protist may have an indirect but important role in AMD ecosystems but also in other ecological niches often described as nitrogen-limited. PMID:22237547

Quality optimized medical image information hiding algorithm that employs edge detection and data coding.

PubMed

Al-Dmour, Hayat; Al-Ani, Ahmed

2016-04-01

The present work has the goal of developing a secure medical imaging information system based on a combined steganography and cryptography technique. It attempts to securely embed patient's confidential information into his/her medical images. The proposed information security scheme conceals coded Electronic Patient Records (EPRs) into medical images in order to protect the EPRs' confidentiality without affecting the image quality and particularly the Region of Interest (ROI), which is essential for diagnosis. The secret EPR data is converted into ciphertext using private symmetric encryption method. Since the Human Visual System (HVS) is less sensitive to alterations in sharp regions compared to uniform regions, a simple edge detection method has been introduced to identify and embed in edge pixels, which will lead to an improved stego image quality. In order to increase the embedding capacity, the algorithm embeds variable number of bits (up to 3) in edge pixels based on the strength of edges. Moreover, to increase the efficiency, two message coding mechanisms have been utilized to enhance the ±1 steganography. The first one, which is based on Hamming code, is simple and fast, while the other which is known as the Syndrome Trellis Code (STC), is more sophisticated as it attempts to find a stego image that is close to the cover image through minimizing the embedding impact. The proposed steganography algorithm embeds the secret data bits into the Region of Non Interest (RONI), where due to its importance; the ROI is preserved from modifications. The experimental results demonstrate that the proposed method can embed large amount of secret data without leaving a noticeable distortion in the output image. The effectiveness of the proposed algorithm is also proven using one of the efficient steganalysis techniques. The proposed medical imaging information system proved to be capable of concealing EPR data and producing imperceptible stego images with minimal embedding distortions compared to other existing methods. In order to refrain from introducing any modifications to the ROI, the proposed system only utilizes the Region of Non Interest (RONI) in embedding the EPR data. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Endoscopic endonasal transsphenoidal surgery: surgical results of 228 pituitary adenomas treated in a pituitary center.

PubMed

Gondim, Jackson A; Schops, Michele; de Almeida, João Paulo C; de Albuquerque, Lucas Alverne F; Gomes, Erika; Ferraz, Tânia; Barroso, Francisca Andréa C

2010-01-01

Pituitary tumors are challenging tumors in the sellar region. Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. The introduction of the endoscope have revolutionized pituitary surgery. The aim of this study is to report the results of a consecutive series of patients undergoing pituitary surgery using a pure endoscopic endonasal approach and to evaluate the efficacy and safety of this procedure. We reviewed the data of 228 consecutive patients who underwent endonasal transsphenoidal adenoma removal over an 10-year period. Pre- and post-operative hormonal status (at least 3 months after surgery) were analyzed and compared with clinical parameters presented by the patients. Tumor removal rate, endocrinological outcomes, and complications were retrospectively assessed in 228 patients with pituitary adenomas who underwent 251 procedures between December 1998 and December 2007. There were 93 nonfunctioning adenomas, 58 growth hormone-secreting, 41 prolactin-secreting, 28 adrenocorticotropin hormone secreting, 7 FSH-LH secreting and 1 thyroid-stimulating hormone-secreting adenomas. Gross total removal was achieved in 79.3% of the cases after a median follow-up of 61.5 months. The remission results for patients with nonfunctioning adenomas was 83% and for functioning adenomas were 76.3% (70.6% for GH hormone-secreting, 85.3% for prolactin hormone-secreting, 71.4% for ACTH hormone-secreting, 85.7% for FSH-LH hormone-secreting and 100% for TSH hormone-secreting), with no recurrence at the time of the last follow-up. Post-operative complications were present in 35 (13.9%) cases. The most frequent complications were temporary and permanent diabetes insipidus (six and two cases, respectively), syndrome of inappropriate antidiuretic hormone secretion (two cases) and CSF leaks (eight cases). There was no death related to the procedure in this series. The endoscopic endonasal approach for resection of pituitary adenomas, provides acceptable results representing a safe alternative procedure to the microscopic approach. This less invasive method, associated with a small number of complications, provides excellent tumor removal rates and represents an important tool for the achievement of good results in the pituitary surgery, mainly for the complete removal of large adenomas.

Reduced active transcellular intestinal oxalate secretion contributes to the pathogenesis of obesity-associated hyperoxaluria.

PubMed

Amin, Ruhul; Asplin, John; Jung, Daniel; Bashir, Mohamed; Alshaikh, Altayeb; Ratakonda, Sireesha; Sharma, Sapna; Jeon, Sohee; Granja, Ignacio; Matern, Dietrich; Hassan, Hatim

2018-05-01

Most kidney stones are composed of calcium oxalate, and minor changes in urine oxalate affect the stone risk. Obesity is a risk factor for kidney stones and a positive correlation of unknown etiology between increased body size, and elevated urinary oxalate excretion has been reported. Here, we used obese ob/ob (ob) mice to elucidate the pathogenesis of obesity-associated hyperoxaluria. These ob mice have significant hyperoxaluria (3.3-fold) compared with control mice, which is not due to overeating as shown by pair-feeding studies. Dietary oxalate removal greatly ameliorated this hyperoxaluria, confirming that it is largely enteric in origin. Transporter SLC26A6 (A6) plays an essential role in active transcellular intestinal oxalate secretion, and ob mice have significantly reduced jejunal A6 mRNA (- 80%) and total protein (- 62%) expression. While net oxalate secretion was observed in control jejunal tissues mounted in Ussing chambers, net absorption was seen in ob tissues, due to significantly reduced secretion. We hypothesized that the obesity-associated increase in intestinal and systemic inflammation, as reflected by elevated proinflammatory cytokines, suppresses A6-mediated intestinal oxalate secretion and contributes to obesity-associated hyperoxaluria. Indeed, proinflammatory cytokines (elevated in ob mice) significantly decreased intestinal oxalate transport in vitro by reducing A6 mRNA and total protein expression. Proinflammatory cytokines also significantly reduced active mouse jejunal oxalate secretion, converting oxalate transport from net secretion in vehicle-treated tissues to net absorption in proinflammatory cytokines-treated tissues. Thus, reduced active intestinal oxalate secretion, likely secondary to local and systemic inflammation, contributes to the pathogenesis of obesity-associated hyperoxaluria. Hence, proinflammatory cytokines represent potential therapeutic targets. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

The effect of serum on the secretion of radiolabeled mucous macromolecules into the lumen of the cat trachea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peatfield, A.C.; Hall, R.L.; Richardson, P.S.

1982-02-01

We studied the effect of placing serum within a segment of trachea on secretion into its lumen in the cat. A segment of cervical trachea was isolated from the rest of the airway in situ. Secretions were radiolabeled biosynthetically by the administration of two radiolabeled precursors: (35S)sodium sulphate and (3H)glucose. Autologous serum placed in the segment at a dilution of 1 in 8 increased the output of radiolabeled macromolecules: (35S) by 80% and (3H) by 159% (p less than 0.001). At a dilution of 1 in 24, serum still increased the output of both isotopes. At dilutions of 1 inmore » 48 and 1 in 80 the increases were significant for (35S) but not for (3H). Heating the serum to 90 degrees C diminished its effects. Fractionating the serum by dialysis and gel filtration showed that the components of molecular weight less than about 13,000 daltons had no effect on secretion, whereas three higher molecular weight fractions all increased secretion. Two alien proteins (horseradish peroxidase and bovine serum albumin) stimulated secretion but a large molecular weight carbohydrate (carboxymethyl cellulose) did not. Atropine and propranolol, at doses that greatly reduced the effect of parasympathetic and sympathetic nerve activity, did not diminish the effects of serum, which therefore appeared to be independent of nerve activity. Gel filtration of the secretions elicited by serum showed that the predominant component was excluded even by Sepharose CL-2B and thus had a high molecular weight. We conclude that there are several components of serum that promote the secretion of mucus glycoproteins into the cat trachea. The relevance of these findings to diseases of human airways is considered.« less

Differential compartmentalization of Streptococcus pyogenes virulence factors and host protein binding properties as a mechanism for host adaptation.

PubMed

Kilsgård, Ola; Karlsson, Christofer; Malmström, Erik; Malmström, Johan

2016-11-01

Streptococcus pyogenes is an important human pathogen responsible for substantial morbidity and mortality worldwide. Although S. pyogenes is a strictly human pathogen with no other known animal reservoir, several murine infection models exist to explore different aspects of the bacterial pathogenesis. Inoculating mice with wild-type S. pyogenes strains can result in the generation of new bacterial phenotypes that are hypervirulent compared to the original inoculum. In this study, we used a serial mass spectrometry based proteomics strategy to investigate if these hypervirulent strains have an altered distribution of virulence proteins across the intracellular, surface associated and secreted bacterial compartments and if any change in compartmentalization can alter the protein-protein interaction network between bacteria and host proteins. Quantitative analysis of the S. pyogenes surface and secreted proteomes revealed that animal passaged strains are associated with significantly higher amount of virulence factors on the bacterial surface and in the media. This altered virulence factor compartmentalization results in increased binding of several mouse plasma proteins to the bacterial surface, a trend that was consistent for mouse plasma from several different mouse strains. In general, both the wild-type strain and animal passaged strain were capable of binding high amounts of human plasma proteins. However, compared to the non-passaged strains, the animal passaged strains displayed an increased ability to bind mouse plasma proteins, in particular for M protein binders, indicating that the increased affinity for mouse blood plasma proteins is a consequence of host adaptation of this pathogen to a new host. In conclusion, plotting the total amount of virulence factors against the total amount of plasma proteins associated to the bacterial surface could clearly separate out animal passaged strains from wild type strains indicating a virulence model that could predict the virulence of a S. pyogenes strain in mice and which could be used to identify key aspects of this bacteria's pathogenesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

Chloride secretion induced by rotavirus is oxidative stress-dependent and inhibited by Saccharomyces boulardii in human enterocytes.

PubMed

Buccigrossi, Vittoria; Laudiero, Gabriella; Russo, Carla; Miele, Erasmo; Sofia, Morena; Monini, Marina; Ruggeri, Franco Maria; Guarino, Alfredo

2014-01-01

Rotavirus (RV) infection causes watery diarrhea via multiple mechanisms, primarily chloride secretion in intestinal epithelial cell. The chloride secretion largely depends on non-structural protein 4 (NSP4) enterotoxic activity in human enterocytes through mechanisms that have not been defined. Redox imbalance is a common event in cells infected by viruses, but the role of oxidative stress in RV infection is unknown. RV SA11 induced chloride secretion in association with an increase in reactive oxygen species (ROS) in Caco-2 cells. The ratio between reduced (GSH) and oxidized (GSSG) glutathione was decreased by RV. The same effects were observed when purified NSP4 was added to Caco-2 cells. N-acetylcysteine (NAC), a potent antioxidant, strongly inhibited the increase in ROS and GSH imbalance. These results suggest a link between oxidative stress and RV-induced diarrhea. Because Saccharomyces boulardii (Sb) has been effectively used to treat RV diarrhea, we tested its effects on RV-infected cells. Sb supernatant prevented RV-induced oxidative stress and strongly inhibited chloride secretion in Caco-2 cells. These results were confirmed in an organ culture model using human intestinal biopsies, demonstrating that chloride secretion induced by RV-NSP4 is oxidative stress-dependent and is inhibited by Sb, which produces soluble metabolites that prevent oxidative stress. The results of this study provide novel insights into RV-induced diarrhea and the efficacy of probiotics.

Fat digestion and absorption in spice-pretreated rats.

PubMed

Prakash, Usha N S; Srinivasan, Krishnapura

2012-02-01

A few common spices are known to stimulate secretion of bile with higher amount of bile acids which play a major role in digestion and absorption of dietary lipids. It would be appropriate to verify if these spices enable efficient digestion and absorption during high-fat intake. In this context, dietary ginger (0.05%), piperine (0.02%), capsaicin (0.015%), and curcumin (0.5%) were examined for their influence on bile secretion, digestive enzymes of pancreas and absorption of dietary fat in high-fat (30%) fed Wistar rats for 8 weeks. These spices enhanced the activity of pancreatic lipase, amylase, trypsin and chymotrypsin by 22-57%, 32-51%, 63-81% and 12-38%, respectively. Dietary intake of spices along with high-fat enhanced fat absorption. These dietary spices increased bile secretion with higher bile acid content. Stimulation of lipid mobilisation from adipose tissue was suggested by the decrease in perirenal adipose tissue weight by dietary capsaicin and piperine. This was also accompanied by prevention of the accumulation of triglyceride in liver and serum in high-fat fed rats. Activities of key lipogenic enzymes in liver were reduced which was accompanied by an increased activity of hormone-sensitive lipase. Thus, dietary ginger and other spice compounds enhance fat digestion and absorption in high-fat fed situation through enhanced secretion of bile salts and a stimulation of the activity pancreatic lipase. At the same time, the energy expenditure is facilitated by these spices to prevent the accumulation of absorbed fat. Copyright © 2011 Society of Chemical Industry.

A dark brown roast coffee blend is less effective at stimulating gastric acid secretion in healthy volunteers compared to a medium roast market blend.

PubMed

Rubach, Malte; Lang, Roman; Bytof, Gerhard; Stiebitz, Herbert; Lantz, Ingo; Hofmann, Thomas; Somoza, Veronika

2014-06-01

Coffee consumption sometimes is associated with symptoms of stomach discomfort. This work aimed to elucidate whether two coffee beverages, containing similar amounts of caffeine, but differing in their concentrations of (β) N-alkanoyl-5-hydroxytryptamides (C5HTs), chlorogenic acids (CGAs), trigonelline, and N-methylpyridinium (N-MP) have different effects on gastric acid secretion in healthy volunteers. The intragastric pH after administration of bicarbonate with/without 200 mL of a coffee beverage prepared from a market blend or dark roast blend was analyzed in nine healthy volunteers. Coffee beverages were analyzed for their contents of C5HT, N-MP, trigonelline, CGAs, and caffeine using HPLC-DAD and HPLC-MS/MS. Chemical analysis revealed higher concentrations of N-MP for the dark brown blend (87 mg/L) compared to the market blend coffee (29 mg/L), whereas concentrations of C5HT (0.012 versus 0.343 mg/L), CGAs (323 versus 1126 mg/L), and trigonelline (119 versus 343 mg/L) were lower, and caffeine concentrations were similar (607 versus 674 mg/mL). Gastric acid secretion was less effectively stimulated after administration of the dark roast blend coffee compared to the market blend. Future studies are warranted to verify whether a high ratio of N-MP to C5HT and CGAs is beneficial for reducing coffee-associated gastric acid secretion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A microfluidic platform for chemical stimulation and real time analysis of catecholamine secretion from neuroendocrine cells.

PubMed

Ges, Igor A; Brindley, Rebecca L; Currie, Kevin P M; Baudenbacher, Franz J

2013-12-07

Release of neurotransmitters and hormones by calcium-regulated exocytosis is a fundamental cellular process that is disrupted in a variety of psychiatric, neurological, and endocrine disorders. As such, there is significant interest in targeting neurosecretion for drug and therapeutic development, efforts that will be aided by novel analytical tools and devices that provide mechanistic insight coupled with increased experimental throughput. Here, we report a simple, inexpensive, reusable, microfluidic device designed to analyze catecholamine secretion from small populations of adrenal chromaffin cells in real time, an important neuroendocrine component of the sympathetic nervous system and versatile neurosecretory model. The device is fabricated by replica molding of polydimethylsiloxane (PDMS) using patterned photoresist on silicon wafer as the master. Microfluidic inlet channels lead to an array of U-shaped "cell traps", each capable of immobilizing single or small groups of chromaffin cells. The bottom of the device is a glass slide with patterned thin film platinum electrodes used for electrochemical detection of catecholamines in real time. We demonstrate reliable loading of the device with small populations of chromaffin cells, and perfusion/repetitive stimulation with physiologically relevant secretagogues (carbachol, PACAP, KCl) using the microfluidic network. Evoked catecholamine secretion was reproducible over multiple rounds of stimulation, and graded as expected to different concentrations of secretagogue or removal of extracellular calcium. Overall, we show this microfluidic device can be used to implement complex stimulation paradigms and analyze the amount and kinetics of catecholamine secretion from small populations of neuroendocrine cells in real time.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bass, H.; Mosmann, T.; Strober, S.

Purified CD4+ BALB/c spleen T cells obtained 4-6 wk after total lymphoid irradiation (TLI) helped normal syngeneic B cells to produce a vigorous antibody response to TNP keyhole limpet hemocyanin in adoptive cell transfer experiments. However, the same cells failed to transfer delayed-type hypersensitivity to the adoptive hosts as measured by a foot pad swelling assay. In addition, purified CD4+ cells from TLI-treated mice were unable to induce graft vs. host disease in lethally irradiated allogeneic C57BL/Ka recipient mice. In response to mitogen stimulation, unfractionated spleen cells obtained from TLI mice secreted normal levels of IL-4 and IL-5, but markedlymore » reduced levels of IL-2 and INF-gamma. A total of 229 CD4+ clones from spleen cells of both normal and TLI-treated mice were established, and the cytokine secretion pattern from each clone was analyzed. The results demonstrate that the ratio of Th1- and Th2-like clones in the spleens of normal BALB/c mice is 1:0.6, whereas the ratio in TLI mice is approximately 1:7. These results suggest that Th2-like cells recover rapidly (at approximately 4-6 wk) after TLI treatment and account for the early return of antibody helper activity and secretion of IL-4 and IL-5, but Th1-like cells recover more slowly (in approximately 3 mo) after irradiation, and this accounts for the deficit in cell-mediated immunity and the reduced amount of IL-2 and IFN-gamma secretion.« less

Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network

PubMed Central

Yang, Bin; Zhang, Jianfeng

2017-01-01

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme. PMID:28657588

Effect of Tree Species on Enzyme Secretion by the Shiitake Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

PubMed

Plotnikov, Evgeny V; Glukhova, Lubov B; Sokolyanskaya, Ludmila O; Karnachuk, Olga V; Solioz, Marc

2016-01-01

We compared cold and hot wood extracts of 3 endemic Siberian trees-namely, Prunus padus (bird cherry), Populus tremula (aspen), and Betula sp. (birch)-on biomass production and laccase and peroxidase secretion in submerged cultures by the medicinal mushroom Lentinus edodes. Of the conditions tested, only hot Prunus extracts stimulated biomass production, whereas all extracts stimulated laccase and peroxidase secretion, albeit to different extents. A large, differential stimulation of manganese peroxidase was observed by hot Prunus extracts. The results highlight important differences between tree species in the stimulation of biomass and enzyme production by L. edodes and point to potentially interesting stimulatory factors present in hot Prunus extracts. These findings are of relevance in the use of L. edodes for medicinal or biotechnological applications.

Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network.

PubMed

Yang, Bin; Zhang, Jianfeng

2017-06-28

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme.

Natural compound cudraflavone B shows promising anti-inflammatory properties in vitro.

PubMed

Hošek, Jan; Bartos, Milan; Chudík, Stanislav; Dall'Acqua, Stefano; Innocenti, Gabbriella; Kartal, Murat; Kokoška, Ladislav; Kollár, Peter; Kutil, Zsófia; Landa, Přemysl; Marek, Radek; Závalová, Veronika; Žemlička, Milan; Šmejkal, Karel

2011-04-25

Cudraflavone B (1) is a prenylated flavonoid found in large amounts in the roots of Morus alba, a plant used as a herbal remedy for its reputed anti-inflammatory properties. The present study shows that this compound causes a significant inhibition of inflammatory mediators in selected in vitro models. Thus, 1 was identified as a potent inhibitor of tumor necrosis factor α (TNFα) gene expression and secretion by blocking the translocation of nuclear factor κB (NF-κB) from the cytoplasm to the nucleus in macrophages derived from a THP-1 human monocyte cell line. The NF-κB activity reduction resulted in the inhibition of cyclooxygenase 2 (COX-2) gene expression. Compound 1 acts as a COX-2 and COX-1 inhibitor with higher selectivity toward COX-2 than indomethacin. Pretreatment of cells by 1 shifted the peak in an regulatory gene zinc-finger protein 36 (ZFP36) expression assay. This natural product has noticeable anti-inflammatory properties, suggesting that 1 potentially could be used for development as a nonsteroidal anti-inflammatory drug lead.

Triacylglycerol estolides, a new class of mammalian lipids, in the paracloacal gland of the brushtail possum (Trichosurus vulpecula).

PubMed

McLean, Stuart; Davies, Noel W; Nichols, David S; Mcleod, Bernie J

2015-06-01

The paracloacal glands are the most prevalent scent glands in marsupials, and previous investigation of their secretions in the brushtail possum (Trichosurus vulpecula) has identified many odorous compounds together with large amounts of neutral lipids. We have examined the lipids by LC-MS, generating ammonium adducts of acylglycerols by electrospray ionisation. Chromatograms showed a complex mixture of coeluting acylglycerols, with m/z from about 404 to 1048. Plots of single [M + NH4](+) ions showed three groups of lipids clearly separated by retention time. MS-MS enabled triacylglycerols and diacylglycerol ethers to be identified from neutral losses and formation of diacylglycerols and other product ions. The earliest-eluting lipids were found to be triacylglycerol estolides, in which a fourth fatty acid forms an ester link with a hydroxy fatty acid attached to the glycerol chain. This is the first report of triacylglycerol estolides in animals. They form a complex mixture with the triacylglycerols and diacylglycerol ethers of lipids with short- and long-chain fatty acids with varying degrees of unsaturation. This complexity suggests a functional role, possibly in social communication.

The role of calcium and magnesium in the concrete tubes of the sandcastle worm.

PubMed

Sun, ChengJun; Fantner, Georg E; Adams, Jonathan; Hansma, Paul K; Waite, J Herbert

2007-04-01

Sandcastle worms Phragmatopoma californica build mound-like reefs by sticking together large numbers of sand grains with cement secreted from the building organ. The cement consists of protein plus substantial amounts of calcium and magnesium, which are not invested in any mineral form. This study examined the effect of calcium and magnesium depletion on the structural and mechanical properties of the cement. Divalent ion removal by chelating with EDTA led to a partial collapse of cement architecture and cement dislodgement from silica surfaces. Mechanical properties examined were sand grain pull-out force, tube resistance to compression and cement adhesive force. EDTA treatment reduced sand grain pull-out forces by 60% and tube compressive strength by 50% relative to controls. EDTA lowered both the maximal adhesive force and energy dissipation of cement by up to an order of magnitude. The adhesiveness of calcium- and magnesium-depleted cement could not be restored by re-exposure to the ions. The results suggest that divalent ions play a complex and multifunctional role in maintaining the structure and stickiness of Phragmatopoma cement.

Emerging roles of basophils in allergic inflammation.

PubMed

Miyake, Kensuke; Karasuyama, Hajime

2017-07-01

Basophils have long been neglected in immunological studies because they were regarded as only minor relatives of mast cells. However, recent advances in analytical tools for basophils have clarified the non-redundant roles of basophils in allergic inflammation. Basophils play crucial roles in both IgE-dependent and -independent allergic inflammation, through their migration to the site of inflammation and secretion of various mediators, including cytokines, chemokines, and proteases. Basophils are known to produce large amounts of IL-4 in response to various stimuli. Basophil-derived IL-4 has recently been shown to play versatile roles in allergic inflammation by acting on various cell types, including macrophages, innate lymphoid cells, fibroblasts, and endothelial cells. Basophil-derived serine proteases are also crucial for the aggravation of allergic inflammation. Moreover, recent reports suggest the roles of basophils in modulating adaptive immune responses, particularly in the induction of Th2 differentiation and enhancement of humoral memory responses. In this review, we will discuss recent advances in understanding the roles of basophils in allergic inflammation. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

A symbiont-produced protein and bacterial symbiosis in Amoeba proteus.

PubMed

Pak, J W; Jeon, K W

1997-01-01

Gram symbiotic X-bacteria present in the xD strain of Amoeba proteus as required cell components, synthesize and export a large amount of a 29-kDa protein (S29x) into the host's cytoplasm across bacterial and symbiosome membranes. The S29x protein produced by E. coli transformed with the s29x gene is also rapidly secreted into the culture medium. Inside amoebae, S29x enters the host's nucleus as detected by confocal and immunoelectron microscopy, although it is not clear if S29x is selectively accumulated inside the nucleus. The deduced amino-acid sequence of S29x has a stretch of basic amino acids that could act as a nuclear localization signal, but there is no signal peptide at the N-terminus and the transport of S29x is energy independent. The functions of S29x are not known, but in view of its prominent presence inside the amoeba's nucleus, S29x is suspected to be involved in affecting the expression of amoeba's nuclear gene(s).

An alpha-numeric code for representing N-linked glycan structures in secreted glycoproteins.

PubMed

Yusufi, Faraaz Noor Khan; Park, Wonjun; Lee, May May; Lee, Dong-Yup

2009-01-01

Advances in high-throughput techniques have led to the creation of increasing amounts of glycome data. The storage and analysis of this data would benefit greatly from a compact notation for describing glycan structures that can be easily stored and interpreted by computers. Towards this end, we propose a fixed-length alpha-numeric code for representing N-linked glycan structures commonly found in secreted glycoproteins from mammalian cell cultures. This code, GlycoDigit, employs a pre-assigned alpha-numeric index to represent the monosaccharides attached in different branches to the core glycan structure. The present branch-centric representation allows us to visualize the structure while the numerical nature of the code makes it machine readable. In addition, a difference operator can be defined to quantitatively differentiate between glycan structures for further analysis. The usefulness and applicability of GlycoDigit were demonstrated by constructing and visualizing an N-linked glycosylation network.

[The ultradian rhythm of sleep: diverse relations with pituitary and adrenal hormones].

PubMed

Brandenberger, G

2003-11-01

We evaluated the relationship between the ultradian rhythm of sleep and the secretory episodes of pituitary-adrenal hormones. Prolactin (PRL) and TSH exhibited opposite phase relationships with delta waves, PRL increasing and TSH decreasing when delta waves developed. Delta waves never increased together with an increase in cortisol secretion. They oscillated independently from each other throughout the 24 hour period, but when they were present at the same time, they oscillated in opposing phases. Concerning growth hormone (GH), its major peak which occurred shortly after sleep onset in association with the first slow wave sleep episode was blunted during sleep deprivation. However, this blunting was compensated during the day, so that the amount of GH secreted during a 24-hr period was similar whether or not a person had slept during the night. The physiological significance and the clinical implications of the various relationships of the endocrine systems with sleep are poorly known.

The ultrastructural basis of steroid production in the Y-organ and the mandibular organ of the crabs Hemigrapsus nudus (Dana) and Carcinus maenas L.

PubMed

Buchholz, C; Adelung, D

1980-01-01

The ultrastructure of the steroid producing Y-organ and the mandibular organ of the crustaceans Hemigrapsus nudus and Carcinus maenas has been studied with reference to the well investigated steroid secreting cells (SSC) of mammals. In accordance with the most important characteristic of mammalian SSC, abundant SER could be shown in the Y-organ, where it is unevenly distributed. The amount of SER seems to vary in correlation with the secretion of moulting hormone during the moult cycle. Most Y-organ cells contain a great number of mitochondria of the tubular type, another important characteristic of mammalian SSC. The ultrastructure of the mandibular organ of C. maenas differs considerably from that of the Y-organ. Some SER was found, mitochondria of unusual shape and size were conspicuous. No definite conclusion as to the function of the mandibular organ is yet to be drawn.

Inducing gravitropic curvature of primary roots of Zea mays cv Ageotropic

NASA Technical Reports Server (NTRS)

Moore, R.; Evans, M. L.; Fondren, W. M.

1990-01-01

Primary roots of the mutant 'Ageotropic' cultivar of Zea mays are nonresponsive to gravity. Their root caps secrete little or no mucilage and touch the root only at the extreme apex. A gap separates the cap and root at the periphery of the cap. Applying mucilage from normal roots or substances with a consistency similar to that of mucilage to tips of mutant roots causes these roots to become strongly graviresponsive. Gravicurvature stops when these substances are removed. Caps of some mutants secrete small amounts of mucilage and are graviresponsive. These results indicate that (a) the lack of graviresponsiveness in the mutant results from disrupting the transport pathway between the cap and root, (b) movement of the growth-modifying signal from the cap to the root occurs via an apoplastic pathway, and (c) mucilage is necessary for normal communication between the root cap and root in Zea mays cv Ageotropic.

Effect of pancreatic polypeptide on gallbladder pressure and hepatic bile secretion.

PubMed

Adrian, T E; Mitchenere, P; Sagor, G; Bloom, S R

1982-09-01

Intraluminal gallbladder pressure, measured by radiotelemetry, and bile output were monitored during infusion of porcine pancreatic polypeptide (PP) at doses of 6, 25, 100, and 400 pmol . kg-1 . h-1 in healthy conscious pigs. Plasma PP concentrations during infusion of the three lower doses, measured by radioimmunoassay, were within the range seen postprandially in these animals. Gallbladder pressure fell in a dose-related manner during PP infusion by 2.2 +/- 0.9, 8.2 +/- 0.4, 11.6 +/- 0.7, and 14.8 +/- 0.8 mmHg, respectively. In addition, a significant reduction in the bile output was observed during infusion of the two higher doses of PP. In a separate series of experiments, using cholecystectomized pigs, PP had no effect on bile output. These findings suggest that the amount of PP released postprandially may be sufficient to influence gallbladder function but not hepatic secretion of bile in the pig.

Intraoperative hypertensive crisis due to a catecholamine-secreting esthesioneuroblastoma.

PubMed

Salmasi, Vafi; Schiavi, Adam; Binder, Zev A; Ruzevick, Jacob; Orr, Brent A; Burger, Peter C; Ball, Douglas W; Blitz, Ari M; Koch, Wayne M; Ishii, Masaru; Gallia, Gary L

2015-06-01

Although uncommon, esthesioneuroblastomas may produce clinically significant amounts of catecholamines. We report a patient with a catecholamine-secreting esthesioneuroblastoma who developed an intraoperative hypertensive crisis. A patient with a history of hypertension was referred to our skull base center for management of a residual esthesioneuroblastoma. A staged endonasal endoscopic approach was planned. At the conclusion of the first stage, a hypertensive crisis occurred. Workup revealed elevated levels of serum and urinary catecholamines. The patient was treated with alpha adrenoceptor blockade before the second stage. Serum catecholamine levels after this second stage were normal. On immunohistochemical analysis, the tumor cells were found to be positive for tyrosine hydroxylase, the rate limiting enzyme in catecholamine synthesis, and achaete-scute homologue 1, a transcription factor essential in the development of olfactory and sympathetic neurons. Catecholamine production should be considered in the differential of unexpected extreme hypertension during surgical resection of esthesioneuroblastoma. © 2015 Wiley Periodicals, Inc.

Intraoperative hypertensive crisis due to a catecholamine-secreting esthesioneuroblastoma

PubMed Central

Salmasi, Vafi; Schiavi, Adam; Binder, Zev A.; Ruzevick, Jacob; Orr, Brent A.; Burger, Peter C.; Ball, Douglas W.; Blitz, Ari M.; Koch, Wayne M.; Ishii, Masaru; Gallia, Gary L.

2015-01-01

Background Although uncommon, esthesioneuroblastomas may produce clinically significant amounts of catecholamines. Methods We report a patient with a catecholamine-secreting esthesioneuroblastoma who developed intraoperative hypertensive crisis. Results A patient with history of hypertension was referred to our skull base center for management of a residual esthesioneuroblastoma. A staged endonasal endoscopic approach was planned. At the conclusion of the first stage, a hypertensive crisis occurred. Work-up revealed elevated levels of serum and urinary catecholamines. The patient was treated with alpha adrenoceptor blockade prior to the second stage. Serum catecholamine levels following this second stage were normal. On immunohistochemical analysis, the tumor cells were found to be positive for tyrosine hydroxylase, the rate limiting enzyme in cathecholamine synthesis, and achaete-scute homologue 1, a transcription factor essential in the development of olfactory and sympathetic neurons. Conclusion Catecholamine production should be considered in the differential of unexpected extreme hypertension during surgical resection of esthesioneuroblastoma. PMID:25352487

Efficient Purification and Optimization of Wnt3a, a Novel Therapeutic for Tissue Regeneration

NASA Astrophysics Data System (ADS)

Madhav, D.; Helms, J.; Dhamdhere, G.

2012-12-01

Wnt is a secreted protein that is present naturally in the body. When an organism is injured the amount of Wnt in the affected area increases. This protein acts as an activator of adult stem cells and signals them to begin differentiating and proliferating. This stem cell response augments the ongoing efforts of injured cells to heal faster by becoming the cells that were damaged by the injury. Adult stem cells play a great role in the healing of wounds, but as organisms age the amount of stem cells in their body decreases. This decrease, in effect, slows the healing of injuries because no stem cells are present to help the regenerative efforts of the body. The Wnt protein induces these stem cells not only to differentiate and proliferate, but also to self-replicate. The ability of Wnt to induce adult stem cells to self -replicate gives us an option to use the protein as a potential tissue regenerative drug. Post-translational Wnt has a lipid modification that makes the protein insoluble in water. To overcome this we fuse the protein with a liposome. A liposome is a lipid sphere with an aqueous center and a phospholipid membrane. The Wnt protein does not lose its function when joined with a liposome. Using this knowledge we can develop a viable means to inject the Wnt protein directly into organisms. The big problem now is to make enough purified Wnt to manufacture on a large scale.

Subclinical Phaeochromocytoma

PubMed Central

Mannelli, Massimo; Lenders, Jacques W.M.; Pacak, Karel; Parenti, Gabriele; Eisenhofer, Graeme

2012-01-01

Phaeochromocytomas and paragangliomas are neural crest-derived tumours. Autopsy studies indicate that relatively large numbers of these tumours remain undiagnosed during life. This may reflect non-specific signs and symptoms and low medical alertness in evaluating the clinical picture or it may reflect a silent clinical presentation - the subclinical phaeochromocytoma. The associated clinical picture depends on the capacity of the tumours to release catecholamines and sometimes biologically active peptides. Hypertension is the hallmark of catecholamine release, but the amount, type and pattern of catecholamine secretion is extremely variable. Some tumours have low or intermittent secretory activity, some produce mainly or solely dopamine, while others very rarely do not synthesize or release any catecholamines (non-secretory or non-functional tumours). Such tumours may present with mild or even absent signs and symptoms of catecholamine excess. Low secretory activity may reflect small tumour size or differences in secretory phenotypes associated with the biochemical and genetic background of the tumours. Tumours due to succinate dehydrogenase subunit B mutations are often subclinical, poorly differentiated, contain low amounts of catecholamines, and are usually malignant at diagnosis. Adrenoceptor desensitization can result in a subclinical presentation, even when catecholamine levels are high. Subclinical phaeochromocytomas are often discovered as incidentalomas during radiological procedures or during routine screening for phaeochromocytoma in carriers of mutations in one of the ten currently identified tumour susceptibility genes. Undiagnosed phaeochromocytomas, whether or not subclinical and even if biologically benign, may cause extremely deleterious consequences or even death, following abrupt release of catecholamines. PMID:22863392