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Neuropeptide Y: The story, the players, the outcomes
No full textNeuropeptide Y (NPY) is a peptide consisted of 36 amino acids. It is designated by a capital letter Y due to the presence of many tyrosine residues which are abbreviated by the letter Y in the single letter amino acid code. NPY is one of the most evolutionary conserved peptides, originally isolated from pig brain (Tatemoto et al. 1982; Larhammar 1996). Due to a very wide tissue distribution of NPY and its significance for the human and animal physiology, peptides with high structural homology to NPY, e.g., peptide YY (PYY), pancreatic polypeptide (PP) and their truncated forms NPY2-36, NPY3-36 and PYY3-36, sharing amino acid backbone that forms a hair-pin turn called the PP-fold (Fuhlendorff et al. 1990), are now specified as members of NPY family. NPY was previously considered a companion and amplifier of norepinephrine activity. It is now known that NPY could be stored alone in small vesicles of sympathetic nerves, and in combination with catecholamines in large vesicles (Fried et al. 1985). Although NPY is preferentially released under conditions of high frequency nerve stimulation, the endogenous NPY modulates the effects of norepinephrine at both high and low levels of sympathetic nerve activity (Han et al. 1998)
Amyotrophic Lateral Sclerosis IgGs Enhance the Mobility of Lysotracker-Labelled Vesicles in Cultured Rat Astrocytes
Get PDFCellular and Nerve Fibre Catecholaminergic Thymic Network: Steroid Hormone Dependent Activity
Get PDFThe thymus plays a critical role in establishing and maintaining the peripheral T-cell pool. It does so by providing a microenvironment within which T-cell precursors differentiate and undergo selection processes to create a functional population of major histocompatibility complex-restricted, self-tolerant T cells. These cells are central to adaptive immunity. Thymic T-cell development is influenced by locally produced soluble factors and cell-to-cell interactions, as well as by sympathetic noradrenergic and endocrine system signalling. Thymic lymphoid and non-lymphoid cells have been shown not only to express beta- and alpha(1)-adrenoceptors (ARs), but also to synthesize catecholamines (CAs). Thus, it is suggested that CAs influence T-cell development via both neurocrine/endocrine and autocrine/paracrine action, and that they serve as immunotransmitters between thymocytes and nerves. CAs acting at multiple sites along the thymocyte developmental route affect T-cell generation not only numerically, but also qualitatively. Thymic CA level and synthesis, as well as AR expression exhibit sex steroid-mediated sexual dimorphism. Moreover, the influence of CAs on T-cell development exhibits glucocorticoid-dependent plasticity. This review summarizes recent findings in this field and our current understanding of complex and multifaceted neuroendocrine-immune communications at thymic level
Emergence of NDM-1 Metallo-beta-Lactamase in Pseudomonas aeruginosa Clinical Isolates from Serbia
No full textThis work reports, for the first time, the presence of New Delhi metallo-beta-lactamase 1 (NDM-1) in Pseudomonas aeruginosa. Moreover, this is the first report of the NDM-1 presence in the Balkan region. Cosmid gene libraries of carbapenem-nonsusceptible Pseudomonas aeruginosa clinical isolates MMA83 and MMA533 were screened for the presence of metallo-beta-lactamases. Accordingly, both MMA83 and MMA533 carried the bla(NDM-1) gene. Pulsed-field gel electrophoresis (PFGE) analysis indicated that strains MMA83 and MMA533 belonged to different clonal groups. Five additional isolates from different patients clonally related to either MMA83 or MMA533 were found to be NDM-1 positive
Amyotrophic lateral sclerosis immunoglobulins G enhance the mobility of Lysotracker-labelled vesicles in cultured rat astrocytes
No full textAim: We examined the effect of purified immunoglobulins G (IgG) from patients with amyotrophic lateral sclerosis (ALS) on the mobility and exocytotic release from Lysotracker-stained vesicles in cultured rat astrocytes. Methods: Time-lapse confocal images were acquired, and vesicle mobility was analysed before and after the application of ALS IgG. The vesicle counts were obtained to assess cargo exocytosis from stained organelles. Results: At rest, when mobility was monitored for 2 min in bath with Ca2+, two vesicle populations were discovered: (1) non-mobile vesicles (6.1%) with total track length (TL) lt 1 mu m, averaging at 0.33 +/- 0.01 mu m (n = 1305) and (2) mobile vesicles (93.9%) with TL gt 1 mu m, averaging at 3.03 +/- 0.01 mu m (n = 20 200). ALS IgG (0.1 mg mL(-1)) from 12 of 13 patients increased the TL of mobile vesicles by approx. 24% and maximal displacement (MD) by approx. 26% within 4 min, while the IgG from control group did not alter the vesicle mobility. The mobility enhancement by ALS IgG was reduced in extracellular solution devoid of Ca2+, indicating that ALS IgG vesicle mobility enhancement involves changes in Ca2+ homeostasis. To examine whether enhanced mobility relates to elevated Ca2+ activity, cells were stimulated by 1 mm ATP, a cytosolic Ca2+ increasing agent, in the presence (2 mm) and in the absence of extracellular Ca2+. ATP stimulation triggered an increase in TL by approx. 7% and 12% and a decrease in MD by approx. 11% and 1%, within 4 min respectively. Interestingly, none of the stimuli triggered the release of vesicle cargo. Conclusion: Amyotrophic lateral sclerosis-IgG-enhanced vesicle mobility in astrocytes engages changes in calcium homeostasis
Circulating and Thymic-Derived Glucocorticoids Influence Expression of Key Enzymes Controlling the Metabolism of Catecholamines and Adrenoceptors in Thymocytes
No full textTetanus toxoid purification: Chromatographic procedures as an alternative to ammonium-sulphate precipitation
No full textGiven an existing demand to establish a process of tetanus vaccine production in a way that allows its complete validation and standardization, this paper focuses on tetanus toxoid purification step. More precisely, we were looking at a possibility to replace the widely used ammonium-sulphate precipitation by a chromatographic method. Based on the tetanus toxin's biochemical characteristics, we have decided to examine the possibility of tetanus toxoid purification by hydrophobic chromatography, and by chromatographic techniques based on interaction with immobilized metal ions, i.e. chelating chromatography and immobilized metal affinity chromatography. We used samples obtained from differently fragmented crude tetanus toxins by formaldehyde treatment (assigned as TTd-A and TTd-B) as starting material for tetanus toxoid purification. Obtained results imply that purification of tetanus toxoid by hydrophobic chromatography represents a good alternative to ammonium-sulphate precipitation. Tetanus toxoid preparations obtained by hydrophobic chromatography were similar to those obtained by ammonium-sulphate precipitation in respect to yield, purity and immunogenicity. In addition, their immunogenicity was similar to standard tetanus toxoid preparation (NIBSC, Potters Bar, UK). Furthermore, the characteristics of crude tetanus toxin preparations had the lowest impact on the final purification product when hydrophobic chromatography was the applied method of tetanus toxoid purification. On the other hand, purifications of tetanus toxoid by chelating chromatography or immobilized metal affinity chromatography generally resulted in a very low yield due to not satisfactory tetanus toxoid binding to the column, and immunogenicity of the obtained tetanus toxoid-containing preparations was poor. (C) 2011 Elsevier BM. All rights reserved
Age-Associated Remodeling of Neural and Nonneural Thymic Catecholaminergic Network Affects Thymopoietic Productivity
No full textAgeing is associated with a progressive decline in thymic cytoarchitecture followed by a less efficient T cell development and decreased emigration of naive T cells to the periphery. These thymic changes are linked to increased morbidity and mortality from infectious, malignant and autoimmune diseases in old age. Therefore, it is of paramount importance to understand the thymic homeostatic processes across the life span, as well as to identify factors and elucidate mechanisms driving or contributing to the thymic involution. Catecholamines (CAs) derived from sympathetic nerves and produced locally by thymic cells represent an important component of the thymic microenvironment. In young rats, they provide a subtle tonic suppressive influence on T cell development acting via beta(2)- and alpha(1)-adrenoceptors (ARs) expressed on thymic nonlymphoid cells and thymocytes. In the face of thymic involution, a progressive increase in the thymic noradrenaline level, reflecting a rise in the density of noradrenergic nerve fibers and CA-synthesizing cells, occurs. In addition, the density of beta(2)- and alpha(1)-AR-expressing thymic nonlymphoid cells and the alpha(1)-AR thymocyte surface density also exhibit a pronounced increase with age. The data obtained from studies investigating effects of AR blockade on T cell development indicated that age-related changes in CA-mediated thymic communications, certainly those involving alpha(1)-ARs, may contribute to diminished thymopoietic efficiency in the elderly. Having in mind thymic plasticity in the course of ageing, and broadening possibilities for pharmacological modulation of CA signaling, we here present and discuss the progress in research related to a role of CAs in thymic homeostasis and age-related decay in the thymic naive T cell output. Copyright (C) 2011 S. Karger AG, Base
Diferentovanje timocita u organ kulturi timusa odraslih pacova
Get PDFTo investigate the differences between thymocytes development in vivo and in vitro, thymus lobe fragments from 12-weeks old male Albino Oxford rats were cultivated over a 7-days period. In the controls and cultivated thymic lobes fragments were evaluated and the viability, apoptosis and cell cycle of thymocytes, as well as the histological characteristics of thymic tissue. Additionally, we analyzed the expression of CD4, CD8 and TCRαβ on thymocytes by flow cytometry. The obtained results showed that thymus cellularity decreased during cultivated time due to expanded apoptosis, decreased proliferation and the absence of progenitors reseeding thymus. The relative proportion of thymocyte subsets in the first 24 hours of culture remained similar as in the control. However, cultivation for 3 and 7 days modulated the relative proportions between thymoctye subsets. The percentage of DP TCRαβlow increased, DP TCRαβhi subset remained unchanged, both SP TCRαβhi subsets decreased while the same mature SP phenotype dominated in culture media. These results demonstrate that cultivated thymic fragments retain the capacity for T cell development, although cultivation modulates this process.Sa namerom da ispitamo razlike između in vivo i in vitro sazrevanja timocita gajili smo fragmente lobusa timusa poreklom od mužjaka Albino Oksford pacova, starih dvanaest nedelja, u vremenskom periodu od sedam dana. Nakon kultivacije određivani su vijabilnost, apoptoza i ćelijski ciklus timocita, kao i histološke osobine timusnog tkiva. Takođe je analizirano ispoljavanje markera diferentovanja CD4, CD8 and TCRαβ na površini timocita metodom tečne citofluorometrije. Dobijeni rezultati su ukazali da sedmodnevna kultivacija dovodi do smanjenja broja ćelija u timusu usled povećane apoptoze, smanjene proliferacije i odsustva ulaska progenitora timocita. Tokom prvih 24 sata kultivacije ne dolazi do promena u odnosima timocitnih populacija. Međutim, duže vreme kultivacije - 3 i 7 dana moduliše relativne odnose između timocitnih subpopulacija - povećava se procenat DP TCRαβlow, procenat DP TCRαβhi timocita ostaje nepromenjen, dok su procenti ćelija oba subseta SP TCRαβhi smanjeni, mada je prisustvo pomenutih SP subsetova dominantno u medijumu za kultivaciju. Navedeni rezultati pokazuju da kultivisani fragmenti timusnog tkiva zadržavaju sposobnost da podrže sazrevanje timocita u jednostruko pozitivne T ćelije, mada je diferentovanje timocita donekle modulisano kultivacijom
The effect of mast cells depletion on thioglycollate-induced peritoneal cells phenotype and function in two inbred rat strains
No full textThe aim of the study was to clarify whether strain differences in the phenolype and function of inflammatory peritoneal exudate cells
(PEC) from two inbred rat strains, Dark Agouti (DA) and Albino Oxford (АО), might be connected to their diverse regulation by mast
cells, While thioglycollate injection enhanced proportion of granulocytes among PEC in DA rats paralleled by the increase in the PEC
phagocytosing ability and the decrease in their capacity to produce nitric oxide (NO) and tumor necrosis alpha (TNFalpha),
thioglycollate injection decreased the percentages of granulocytes in AO rats, followed by the increase in both NO and TNFalpha
production of PEC. Mast cells depletion during peritonitis in DA rats, opposite to thioglycollate alone, diminished PEC yield and ability to
produce hydrogen peroxide, and diminished proportion of granulocytes, ED1+ cells and ED2+ cells bearing H1 receptors. In contrast,
mast cell depletion during ongoing peritonitis in AO rat strain exerted mostly additive effects to thioglycollate, observed in the additional
increase of the PEC yield, phagocytosis, hydrogen peroxide, NO and TNFalpha production, and the supplementary decrease in the
percentages of peritoneal granulocytes. Thus, differences in the regulation by peritoneal mast cells might contribute to the variations in
the pentoneal inflammation of DA and AO rat strains (Supported by Ministry of Science, Serbia, Grant 175050)