77 research outputs found

    Noncholinergic functions of cholinesterases

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    Cholinesterases (acetylcholinesterase and butyrylcholinesterase) exhibit additional catalytic activities apart from their well-known action in hydrolyzing choline esters. An amine-sensitive aryl acylamidase activity is exhibited by both acetyl- and butyrylcholinesterases. A metallocarboxypeptidase-like activity is found associated with both acetyl- and butyrylcholinesterases. The peptidase activity exhibited by butyrylcholinesterase was located in a 50-kDa COOH-terminal fragment. Acetylcholinesterase is implicated in noncholinergic functions in the substantia nigra. A relationship between tumorigenesis, cell differentiation, and cholinesterases has been speculated. The sequence similarities between different esterases, lipases, thyroglobulin, cell adhesion proteins, and cholinesterases would make it appear that cholinesterases are capable of exhibiting more than one biological activity and their functions are wider than what is hitherto known

    Hypoglycemic and Antihyperglycemic effect of Ceiba pentandra l. Gaertn in Normal and Streptozotocininduced Diabetic Rats

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    Background: Ceiba pentandra (L.) Gaertn, commonly called silk-cotton tree, has been extensively used by traditional medicine practitioners in Northern and Eastern Nigeria in the control and management of diabetes.Objective: To evaluate the hypoglycaemic and antihyperglycaemic effect of ethanolic extract of Ceiba pentandra bark in normal and streptozotocin induced diabetic rats.Method: Screening activity of the extract was carried out by OGTT. Diabetes mellitus was induced with streptozotocin and graded doses of the ethanolic bark extract (200 and 400 mg/kg, b.w.) were then administered to the experimentally diabetic rats. The blood glucose level was measured at different time intervals.Results: The single dose study of C. pentandra extract at two different doses produced no significant hypoglycaemic effect in normal rats but C. pentandra (200 mg/kg) significantly decreased blood glucose level in diabetic rats. In OGTT, C. pentandra (200 mg/kg) significantly reduced elevated glucose level in normal and diabetic rats. In long term (21 days) study, C. pentandra (200 mg/kg) significantly decreased blood glucose level, total cholesterol and triglycerides level, prevented degeneration of liver and pancreas, and increased serum insulin level and liver glycogen content in diabetic rats. Acute toxicity study in rats did not show any signs of toxicity up to the dose of 2000 mg/kg b.w.Conclusion: The results reveal that the extract improved glucose tolerance in normal and streptozotocininduced diabetic rats. Thus the study suggests that the C. pentandra bark extract could be beneficial in the management of type I diabetes.Keywords: Antihyperglycemic, Ceiba pentandra, glibenclamide, hypoglycaemic, Streptozotocin

    Selective role for superoxide in InsP3 receptor–mediated mitochondrial dysfunction and endothelial apoptosis

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    Reactive oxygen species (ROS) play a divergent role in both cell survival and cell death during ischemia/reperfusion (I/R) injury and associated inflammation. In this study, ROS generation by activated macrophages evoked an intracellular Ca2+ ([Ca2+]i) transient in endothelial cells that was ablated by a combination of superoxide dismutase and an anion channel blocker. [Ca2+]i store depletion, but not extracellular Ca2+ chelation, prevented [Ca2+]i elevation in response to O2.βˆ’ that was inositol 1,4,5-trisphosphate (InsP3) dependent, and cells lacking the three InsP3 receptor (InsP3R) isoforms failed to display the [Ca2+]i transient. Importantly, the O2.βˆ’-triggered Ca2+ mobilization preceded a loss in mitochondrial membrane potential that was independent of other oxidants and mitochondrially derived ROS. Activation of apoptosis occurred selectively in response to O2.βˆ’ and could be prevented by [Ca2+]i buffering. This study provides evidence that O2.βˆ’ facilitates an InsP3R-linked apoptotic cascade and may serve a critical function in I/R injury and inflammation

    Patients with nasopharyngeal carcinoma demonstrate enhanced serum and tissue ceruloplasmin expression

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    The proteomics approach was adopted to study the simultaneous expression of serum proteins in patients with nasopharyngeal carcinoma (NPC). We have subjected unfractionated whole sera of ten newly diagnosed Malaysian Chinese patients with WHO type IIINPC to two dimensional gel electrophoresis (2-DE) and image analysis. The results obtained were then compared to that generated from sera of ten normal healthy controls of the same ethnic group and range of age. Our data demonstrated that the serum high abundance 2-DEproteinprofiles of NPC patients were generally similar to that of the controls, with exception of the ceruloplasmin (CPL) spots (identified by mass spectrometric analysis and MASCOT database search), which showed higher expression. The enhanced expression of CPL in the patients’ sera was confirmed by competitive ELISA. Immunohistochemical analysis of nasopharyngeal lesions of NPC patients demonstrated moderate to strong positive CPL staining in the cytoplasm of cells at the regions of malignancy but only weak cytoplasmic staining at normal epithelial lining areas. When follow-up 2-DE and ELISA studies were performed on five of the NPC patients who responded positively to six months treatment, the difference in CPL expression was no longer significant

    Early over expression of messenger RNA for multiple genes, including insulin, in the Pancreatic Lymph Nodes of NOD mice is associated with Islet Autoimmunity

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    <p>Abstract</p> <p>Background</p> <p>Autoimmune diabetes (T1D) onset is preceded by a long inflammatory process directed against the insulin-secreting Ξ² cells of the pancreas. Deciphering the early autoimmune mechanisms represents a challenge due to the absence of clinical signs at early disease stages. The aim of this study was to identify genes implicated in the early steps of the autoimmune process, prior to inflammation, in T1D. We have previously established that insulin autoantibodies (E-IAA) predict early diabetes onset delineating an early phenotypic check point (window 1) in disease pathogenesis. We used this sub-phenotype and applied differential gene expression analysis in the pancreatic lymph nodes (PLN) of 5 weeks old Non Obese Diabetic (NOD) mice differing solely upon the presence or absence of E-IAA. Analysis of gene expression profiles has the potential to provide a global understanding of the disease and to generate novel hypothesis concerning the initiation of the autoimmune process.</p> <p>Methods</p> <p>Animals have been screened weekly for the presence of E-IAA between 3 and 5 weeks of age. E-IAA positive or negative NOD mice at least twice were selected and RNAs isolated from the PLN were used for microarray analysis. Comparison of transcriptional profiles between positive and negative animals and functional annotations of the resulting differentially expressed genes, using software together with manual literature data mining, have been performed.</p> <p>Results</p> <p>The expression of 165 genes was modulated between E-IAA positive and negative PLN. In particular, genes coding for insulin and for proteins known to be implicated in tissue remodelling and Th1 immunity have been found to be highly differentially expressed. Forty one genes showed over 5 fold differences between the two sets of samples and 30 code for extracellular proteins. This class of proteins represents potential diagnostic markers and drug targets for T1D.</p> <p>Conclusion</p> <p>Our data strongly suggest that the immune related mechanisms taking place at this early age in the PLN, correlate with homeostatic changes influencing tissue integrity of the adjacent pancreatic tissue. Functional analysis of the identified genes suggested that similar mechanisms might be operating during pre-inflammatory processes deployed in tissues i) hosting parasitic microorganisms and ii) experiencing unrestricted invasion by tumour cells.</p

    Genome-Wide Identification and Immune Response Analysis of Serine Protease Inhibitor Genes in the Silkworm, Bombyx mori

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    In most insect species, a variety of serine protease inhibitors (SPIs) have been found in multiple tissues, including integument, gonad, salivary gland, and hemolymph, and are required for preventing unwanted proteolysis. These SPIs belong to different families and have distinct inhibitory mechanisms. Herein, we predicted and characterized potential SPI genes based on the genome sequences of silkworm, Bombyx mori. As a result, a total of eighty SPI genes were identified in B. mori. These SPI genes contain 10 kinds of SPI domains, including serpin, Kunitz_BPTI, Kazal, TIL, amfpi, Bowman-Birk, Antistasin, WAP, Pacifastin, and alpha-macroglobulin. Sixty-three SPIs contain single SPI domain while the others have at least two inhibitor units. Some SPIs also contain non-inhibitor domains for protein-protein interactions, including EGF, ADAM_spacer, spondin_N, reeler, TSP_1 and other modules. Microarray analysis showed that fourteen SPI genes from lineage-specific TIL family and Group F of serpin family had enriched expression in the silk gland. The roles of SPIs in resisting pathogens were investigated in silkworms when they were infected by four pathogens. Microarray and qRT-PCR experiments revealed obvious up-regulation of 8, 4, 3 and 3 SPI genes after infection with Escherichia coli, Bacillus bombysepticus, Beauveria bassiana or B. mori nuclear polyhedrosis virus (BmNPV), respectively. On the contrary, 4, 11, 7 and 9 SPI genes were down-regulated after infection with E. coli, B. bombysepticus, B. bassiana or BmNPV, respectively. These results suggested that these SPI genes may be involved in resistance to pathogenic microorganisms. These findings may provide valuable information for further clarifying the roles of SPIs in the development, immune defence, and efficient synthesis of silk gland protein
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