Role of CD151, A tetraspanin, in porcine reproductive and respiratory syndrome virus infection

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) is a RNA virus causing respiratory and reproductive diseases in swine. The susceptibility for PRRSV varies between the different breeds of swine. In cell culture, PRRSV virus can be propagated in primary porcine alveolar macrophages and some African green monkey kidney cell lines, such as MARC-145 cells. Previous studies have shown that 3' untranslated region (UTR) RNAs of the arteriviruses play an important role in the replication of the virus through interactions with cellular proteins. To better understand the differences in the replication capability of PRRSV in different cell lines, we sought to identify the host cellular proteins interacting with PRRSV 3' UTR RNA. We constructed a cDNA library of MARC-145 cell line in lambda ZAP Express vector and screened the library with the positive sense 3' UTR RNA of PRRSV.</p> <p>Results</p> <p>We found that CD151, a host cellular protein, interacting with PRRSV 3' UTR RNA. The specificity of the interaction between CD151 and PRRSV 3' UTR RNA was examined by gel shift assay as well as North-Western hybridization. The transfection of CD151 expression clone into BHK-21 rendered these cells susceptible to PRRSV infection, and the transfection of siRNA against CD151 into MARC-145 significantly reduced the level of PRRSV infection. Also, anti-CD151 antibody treatment to MARC-145 completely blocked PRRSV infection.</p> <p>Conclusion</p> <p>Based on our results, we suggest that CD151 should cooperate in PRRSV infection <it>in vitro </it>in MARC-145 and BHK-21 cells.</p

Urokinase-type plasminogen activator supports liver repair independent of its cellular receptor

BACKGROUND: The urokinase-type (uPA) and tissue-type (tPA) plasminogen activators regulate liver matrix remodelling through the conversion of plasminogen (Plg) to the active protease plasmin. Based on the efficient activation of plasminogen when uPA is bound to its receptor (uPAR) and on the role of uPA in plasmin-mediated liver repair, we hypothesized that uPA requires uPAR for efficient liver repair. METHODS: To test this hypothesis, we administered one dose of carbon tetrachloride (CCl(4)) to mice with single or combined deficiencies of uPA, uPAR and tPA, and examined hepatic morphology, cellular proliferation, fibrin clearance, and hepatic proteolysis 2–14 days later. RESULTS: Absence of uPAR alone or the combined absence of uPAR and tPA had no impact on the resolution of centrilobular injury, but the loss of receptor-free uPA significantly impaired the clearance of necrotic hepatocytes up to 14 days after CCl(4). In response to the injury, hepatocyte proliferation was normal in mice of all genotypes, except for uPAR-deficient (uPAR°) mice, which had a reproducible but mild decrease by 33% at day 2, with an appropriate restoration of liver mass by 7 days similar to experimental controls. Immunostaining and zymographic analysis demonstrated that uPA alone promoted fibrin clearance from centrilobular regions and efficiently activated plasminogen. CONCLUSION: uPA activates plasminogen and promotes liver matrix proteolysis during repair via a process that neither requires its receptor uPAR nor requires a contribution from its functional counterpart tPA

Synthesis, spectral characterization and some biological studies of transition metal complexes with Schiff base ligand containing N,O and S as donor atoms

Transition metal complexes of Cu(II), Co(II), Ni(II), Zn(II), Cd(II) and Mn(II) have been synthesized with the Schiff base ligand 5-Sub-N-(2-mercaptophenyl)salicylideneimine. Elemental analysis of these complexes suggest that these metal ions forms complexes of type ML(H2O)stoichiometry for Cu(II), Co(II), Ni(II), Zn(II), Cd(II) and Mn(II). The ligand behaves as tridentate and forms coordinate bonds through O, S and N atoms. Magnetic susceptibility, IR, UV – Visible, Mass and ESR spectral studies suggest that Cu(II), Ni(II) complexes posses square planar geometry, whereas Co(II), Zn(II), Cd(II) and Mn(II) complexes posses tetrahedral geometry. The complexes were tested for their antimicrobial activity against the bacterial strains Staphylococcus aureus and Bacillus subtilis.The Schiff base metal complexes evaluated for their antifungal activity against the fungi A. niger and C. oxysporum. The DNA cleavage studies of Schiff base complexes werestudied using Calf – Thymus DNA by agarose gel electrophoresis method

Lack of Guanylate Cyclase C results in increased mortality in mice following liver injury

<p>Abstract</p> <p>Background</p> <p>Guanylate Cyclase C (GC-C) expression in the intestine plays a role in the regulation of fluid and ion transport, as well as epithelial cell apoptosis and proliferation. In the adult rat liver, GC-C expression is increased in response to injury. We hypothesized that GC-C is required for repair/recovery from liver injury.</p> <p>Methods</p> <p>We subjected wild type (WT) and GC-C deficient mice to acute liver injury with a single injection of the hepatotoxin carbon tetrachloride. Changes in the level of expression of GC-C and its ligands uroguanylin and guanylin were quantified by real-time PCR. Liver morphology, and hepatocyte necrosis, apoptosis and proliferation, were examined at 1-3 days post-injury in mice on a mixed genetic background. Survival was followed for 14 days after carbon tetrachloride injection in wild type and GC-C deficient mice on both a mixed genetic background and on an inbred C57BL6/J background.</p> <p>Results</p> <p>GC-C deficient mice on the mixed genetic background nearly all died (median survival of 5 days) following carbon tetrachloride injection while WT littermates experienced only 35% mortality. Elevated levels of TUNEL-positive hepatocyte death on post-injury day 1, increased apoptosis on day 2, and increased areas of centrilobular necrosis on days 2 and 3, were evident in livers from GC-C null mice compared to WT. Collectively these data suggest increased hepatocyte death in the GC-C null mice in the early time period after injury. This corresponds temporally with increased expression of GC-C and its ligands guanylin and uroguanylin in post-injury WT mouse liver. The hepatocyte proliferative response to injury was the same in both genotypes. In contrast, there was no difference in survival between GC-C null and WT mice on the inbred C57BL/6 J background in response to acute liver injury.</p> <p>Conclusions</p> <p>Signalling via GC-C promotes hepatocyte survival <it>in vivo </it>and is required for effective recovery from acute toxic injury to the liver in a strain-specific manner.</p

Lampe1: An ENU-Germline Mutation Causing Spontaneous Hepatosteatosis Identified through Targeted Exon-Enrichment and Next-Generation Sequencing

Using a small scale ENU mutagenesis approach we identified a recessive germline mutant, designated Lampe1 that exhibited growth retardation and spontaneous hepatosteatosis. Low resolution mapping based on 20 intercrossed Lampe1 mice revealed linkage to a ∼14 Mb interval on the distal site of chromosome 11 containing a total of 285 genes. Exons and 50 bp flanking sequences within the critical region were enriched with sequence capture microarrays and subsequently analyzed by next-generation sequencing. Using this approach 98.1 percent of the targeted DNA was covered with a depth of 10 or more reads per nucleotide and 3 homozygote mutations were identified. Two mutations represented intronic nucleotide changes whereas one mutation affected a splice donor site in intron 11–12 of Palmitoyl Acetyl-coenzyme A oxygenase-1 (Acox1), causing skipping of exon 12. Phenotyping of Acox1Lampe1 mutants revealed a progression from hepatosteatosis to steatohepatitis, and ultimately hepatocellular carcinoma. The current approach provides a highly efficient and affordable method to identify causative mutations induced by ENU mutagenesis and animal models relevant to human pathology

Synthesis, characterization and antimicrobial activity of pyrimidine based derivatives,

ABSTRACT: Transition metal complexes of Cu(II), Co(II), Ni(II) and Zn(II) have been synthesized with the Schiff base ligand prepared by the condensation reaction between isooxazol-3-yl amine and salicylaldehyde. Elemental analysis of these complexes suggest that these metal ions forms complexes of type ML 2 (H 2 O) 2 stoichiometry for Cu(II), Co(II), Ni(II) and Zn(II). The ligand behaves as bidentate and forms coordinate bonds through O and N atoms. Magnetic susceptibility, IR, UV -Visible, Mass and ESR spectral studies suggest that Cu(II), Co(II), Ni(II) and Zn(II) complexes posses octahedral geometry. The complexes were tested for their antimicrobial activity against the bacterial strains Staphylococcus aureus and Bacillus subtilis. The Schiff base metal complexes evaluated for their antifungal activity against the fungi Aspergillus niger and Cladosporium oxysporum. The DNA cleavage studies of Schiff base complexes were studied by agarose gel electrophoresis method using Calf -Thymus DNA

Urokinase-type plasminogen activator supports liver repair independent of its cellular receptor

Abstract Background The urokinase-type (uPA) and tissue-type (tPA) plasminogen activators regulate liver matrix remodelling through the conversion of plasminogen (Plg) to the active protease plasmin. Based on the efficient activation of plasminogen when uPA is bound to its receptor (uPAR) and on the role of uPA in plasmin-mediated liver repair, we hypothesized that uPA requires uPAR for efficient liver repair. Methods To test this hypothesis, we administered one dose of carbon tetrachloride (CCl4) to mice with single or combined deficiencies of uPA, uPAR and tPA, and examined hepatic morphology, cellular proliferation, fibrin clearance, and hepatic proteolysis 2–14 days later. Results Absence of uPAR alone or the combined absence of uPAR and tPA had no impact on the resolution of centrilobular injury, but the loss of receptor-free uPA significantly impaired the clearance of necrotic hepatocytes up to 14 days after CCl4. In response to the injury, hepatocyte proliferation was normal in mice of all genotypes, except for uPAR-deficient (uPAR°) mice, which had a reproducible but mild decrease by 33% at day 2, with an appropriate restoration of liver mass by 7 days similar to experimental controls. Immunostaining and zymographic analysis demonstrated that uPA alone promoted fibrin clearance from centrilobular regions and efficiently activated plasminogen. Conclusion uPA activates plasminogen and promotes liver matrix proteolysis during repair via a process that neither requires its receptor uPAR nor requires a contribution from its functional counterpart tPA.</p

Role of CD151, A tetraspanin, in porcine reproductive and respiratory syndrome virus infection-5

<p><b>Copyright information:</b></p><p>Taken from "Role of CD151, A tetraspanin, in porcine reproductive and respiratory syndrome virus infection"</p><p>http://www.virologyj.com/content/4/1/62</p><p>Virology Journal 2007;4():62-62.</p><p>Published online 16 Jun 2007</p><p>PMCID:PMC1906853.</p><p></p> MARC-145 cells. The suppression of the cell surface expression of CD151 by the transfection of siRNA was shown by flow cytometric analysis for the untransfected MARC-145 cells (A1) and the transfected MARC-145 cells (A2). An isotype-matched control is represented by the dotted lines. (B) The effect of siRNA on PRRSV infection was shown by immunofluorescence antibody assay using FITC-conjugated SDOW-17, a MAb against PRRSV nucleocapsid protein for the untransfected MARC-145 cells (B 1) and the transfected MARC-145 cells (B 2)

Role of CD151, A tetraspanin, in porcine reproductive and respiratory syndrome virus infection-2

<p><b>Copyright information:</b></p><p>Taken from "Role of CD151, A tetraspanin, in porcine reproductive and respiratory syndrome virus infection"</p><p>http://www.virologyj.com/content/4/1/62</p><p>Virology Journal 2007;4():62-62.</p><p>Published online 16 Jun 2007</p><p>PMCID:PMC1906853.</p><p></p>RT-PCR and Western blot analysis. (A) RT-PCR showing the amplification of 105 bp amplicon with CD151-specific primers was performed for RNAs isolated from PRRSV-susceptible and -non-susceptible cell lines. M, 123 bp ladder; lane 1, negative RT control; lane 2, negative PCR control; lane 3, HRT; lane 4, MARC-145; lane 5, MDBK; lane 6, BHK-21; lane 7, ST; lane 8, MA-104; lane 9, ST-K; lane 10, Vero; lane 11, CL-2621; lane 12, COS; lane 13, CD151-transfected BHK-21. (B) Western blot analysis using anti-CD151 MAb was performed for cell lysates from PRRSV-susceptible and -non susceptible cell lines. Lane 1, MARC-145; lane 2, BHK-21; lane 3, Vero. (C) Flow cytometric analysis using polyclonal anti-CD151 Ab was performed for MARC-145 (C (1)) and BHK-21 (C (2)) cell lines. An isotype-matched control is represented by the dotted lines