ABSTRACT
Following the publication of the above article, an interested reader drew to the authors' attention that the 'NB4' and 'NB2' panels for the invasion and migration assays shown in Fig. 3B and C on p. 113 appeared to contain overlapping data, such that the data may have been derived from the same original source, even though the panels were intending to have shown results obtained under different experimental conditions. The authors have reexamined their raw data and realized that these data were inadvertently mixed up when Fig. 3B and C were assembled. A corrected version of Fig. 3, showing the data as they should have appeared for the 'NB4' and 'NB2' invasion and migration assay experiments in Fig. 3B and C, is shown on the next page. The authors sincerely apologize for the errors that were introduced into Fig. 3 of the published article, and thank the Editor of Oncology Reports for allowing them the opportunity to publish a Corrigendum. All the authors agree to the publication of the authors, and they apologize to the readership for any inconvenience caused. [Oncology Reports 29: 109116, 2013; DOI: 10.3892/or.2012.2069].
ABSTRACT
Herein, we present two novel ferrocene-containing porous organic polymers, FPOP-1 and FPOP-2, by the Heck reactions of 1,1'-divinylferrocene with two tetrahedral silicon-centered units, i.e., tetrakis(4-bromophenyl)silane and tetrakis(4'-bromo-[1,1'-biphenyl]-4-yl)silane. The resulting materials possess high thermal stability and moderate porosity with the Brunauer-Emmer-Teller (BET) surface areas of 499 m2 g-1 (FPOP-1) and 354 m2 g-1 (FPOP-2) and total pore volumes of 0.43 cm3 g-1 (FPOP-1) and 0.49 cm3 g-1 (FPOP-2). The porosity is comparable to previously reported ferrocene-containing porous polymers. These materials possess comparable CO2 capacities of 1.16 mmol g-1 (5.10 wt%) at 273 K and 1.0 bar, and 0.54 mmol g-1 (2.38 wt%) at 298 K and 1.0 bar (FPOP-1). The found capacities are comparable to, or higher than many porous polymers having similar or higher surface areas. They have high isosteric heats of up to 32.9 kJ mol-1, proving that the affinity between the polymer network and CO2 is high, which can be explained by the presence of ferrocene units in the porous networks. These results indicate that these materials can be promisingly utilized as candidates for the storage or capture of CO2. More ferrocene-containing porous polymers can be designed and synthesized by combining ferrocene units with various aromatic monomers under this strategy and their applications could be explored.
ABSTRACT
Flow fields in the distal end-to-side anastomosis of coronary artery bypass graft are associated with intimal hyperplasia and bypass failure. This work aims to demonstrate the effect of anastomotic angle and diameter ratio on flow field of coronary artery bypass graft. The flow fields inside polydimethylsiloxane models of coronary artery bypass graft with various anastomotic angles (α = 30°, 45°, 60° and 75°) and different diameter ratios (Φ = 0.78 and 1.11) are investigated using particle image velocimetry and computational fluid dynamics method under pulsatile flow condition. The results show that the anastomotic angle is positively correlated with the number and area of the recirculation zone, and the flow field disturbance at the anastomosis will develop in the same direction. Compared with that of Φ = 0.78, when Φ = 1.11, the flow fields at the anastomosis are relatively smoother with less turbulence.
Subject(s)
Anastomosis, Surgical , Pulsatile Flow , Computer Simulation , Coronary Artery Bypass , HydrodynamicsABSTRACT
In this study, we investigated the potential for different components of the measles virus (MV) to induce apoptosis of HeLa cells and explored the apoptotic molecular mechanisms. After testing the 2 envelope glycoproteins hemagglutinin (H) and fusion (F), we found that MV H alone was sufficient to induce the apoptosis of HeLa cells, whereas MV F did not. MV F also had no influence on MV-H-mediated apoptosis. MV H could induce cellular apoptosis in HeLa cells through its interaction with the cellular receptor CD46 via both the TRAIL-mediated extrinsic pathway and the mitochondria-controlled intrinsic pathway, and that cross talk between these 2 pathways occurred during the process. These findings extend the functions of MV envelope glycoproteins in the pathogenesis of MV infection and suggest that MV H may be a potential therapeutic in the treatment of some cancers.
Subject(s)
Apoptosis , Hemagglutinins, Viral/physiology , Measles virus/pathogenicity , Measles/virology , Viral Envelope Proteins/physiology , Antigens, CD/immunology , Antigens, CD/metabolism , Antigens, CD/physiology , HeLa Cells , Hemagglutinins, Viral/genetics , Humans , Measles/pathology , Membrane Cofactor Protein/immunology , Membrane Cofactor Protein/metabolism , Metabolic Networks and Pathways , Viral Envelope Proteins/geneticsABSTRACT
Cervical cancer is a common malignancy in women worldwide, and the occurrence of invasion and metastasis is the major cause for most cancer-related deaths. Epithelial-mesenchymal transition (EMT) has been implicated in the metastasis of primary tumors and provides molecular mechanisms for cervical cancer metastasis. We previously reported that Nogo-B mediates cell motility by binding Fibulin-5. Herein, we show that the increased expression of Nogo-B is correlated with the degree of cervical cancer metastasis. In HeLa cervical cancer cells, overexpression of Nogo-B induces the EMT and promotes cell migration and invasion, while inhibiting cell adhesion. Furthermore, we found that Nogo-B accumulates and co-localizes with Fibulin-5 in pseudopods, and the downstream effects of overexpression of Nogo-B on cell motility could be partially abolished by RNA interference against Fibulin-5. These results suggest that Nogo-B functions as an inducer of cervical cancer metastasis and that this effect is mediated, at least in part, through Fibulin-5.
Subject(s)
Cell Adhesion , Cell Movement , Epithelial-Mesenchymal Transition , Extracellular Matrix Proteins/metabolism , Myelin Proteins/metabolism , Uterine Cervical Neoplasms/pathology , Apoptosis , Blotting, Western , Cell Proliferation , Extracellular Matrix Proteins/antagonists & inhibitors , Extracellular Matrix Proteins/genetics , Female , Humans , Myelin Proteins/genetics , Nogo Proteins , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Uterine Cervical Neoplasms/mortality , Uterine Cervical Neoplasms/therapyABSTRACT
p13 gene was first described in Leucania separata multinuclear polyhedrosis virus (Ls-p13) several years ago, but the function of P13 protein has not been experimentally investigated to date. In this article, we indicated that the expression of p13 from Heliothis armigera single nucleocapsid nucleopolyhedrovirus (Ha-p13) was regulated by both early and late promoter. Luciferase assay demonstrated that the activity of Ha-p13 promoter with hr4 enhancer was more than 100 times in heterologous Sf9 cells than that in nature host Hz-AM1 cells. Both Ls-P13 and Ha-P13 are transmembrane proteins. Confocal microscopic analysis showed that both mainly located in the cytoplasm membrane at 48 h. Results of RNA interference indicated that Ha-p13 was a killing-associated gene for host insects H. armigera. The AcMNPV acquired the mentioned killing activity and markedly accelerate the killing rate when expressing Ls-p13. In conclusion, p13 is a killing associated gene in both homologous and heterologous nucleopolyhedrovirus.
Subject(s)
Baculoviridae/metabolism , Membrane Proteins/metabolism , Viral Proteins/metabolism , Animals , Enhancer Elements, Genetic , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/classification , Membrane Proteins/genetics , Phylogeny , Promoter Regions, Genetic , RNA Interference , RNA, Small Interfering/metabolism , Sf9 Cells , Spodoptera/cytology , Spodoptera/virology , Viral Proteins/antagonists & inhibitors , Viral Proteins/classification , Viral Proteins/geneticsABSTRACT
Suppressor of cytokine signaling 3 (SOCS3) is a likely mediator of feedback inhibition on the leptin receptor and may cause physiological leptin-resistance, leading to the development of obesity. The aim of this study was to identify potential peptides interacting with purified SOCS3 by using a phage-display human liver cDNA library. We developed a T7 select phage-display system with purified SOCS3 as bait to screen a human liver cDNA library. After 4 rounds of screening and sequencing analysis, we found that phage-presenting peptide RGGVVTSNPLGF show significant binding to SOCS3. The peptide sequence was similar to the sequence of amino acids 644-655 of C-terminal extra-polypeptide of very-long-chain acyl-CoA dehydrogenase (VLCAD), which is 1 of 4 flavoproteins that catalyzing the initial step of the mitochondrial fatty acid ß-oxidation, implying a close relationship between SOCS3 and VLCAD. We identified VLCAD as a novel SOCS3 interacting protein both in vitro and vivo, and found that SOCS3 mediates the ubiquitination pathway for proteasomal degradation of VLCAD C-terminal extra-polypeptide via its SOCS-box. Animal experimentation demonstrated that VLCAD is functionally involved in SOCS3 binding and thus, SOCS3 play an important role in the regulation of fatty acid ß-oxidation. In conclusion, SOCS3 is an important factor for lipid metabolism and a potential drug-target for treatment of widespread obesity.
Subject(s)
Lipid Metabolism , Liver/metabolism , Obesity/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Acyl-CoA Dehydrogenase, Long-Chain/chemistry , Acyl-CoA Dehydrogenase, Long-Chain/metabolism , Animals , Fatty Acids/metabolism , Gene Library , Humans , Male , Mice , Mice, Inbred Strains , Obesity/genetics , Peptide Library , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/geneticsABSTRACT
The p13 gene is a group II nucleopolyhedroviruses (NPVs) specific gene and featured by containing upstream mini ORFs (uORF) in its 5' UTR region. However, there are almost no reports published on the functions of the uORFs of p13 gene. In this study, the Luciferase Reporter Assay System was employed to investigate how the mini ORFs of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) p13 gene (Ha-p13) and its rare codons regulated the downstream gene expression. After the coding sequence of uORFs in the Ha-p13 gene was fused to the luciferase reporter gene in the expression vector pGL3 and the plasmid DNA was then transfected into the Hz-AM1 cells, the translation of the fusion protein could be initiated from the start codon of the uORFs. The uAUG and its context in uORF2 seemed to be more efficient for translation initiation than that in uORF1. Mutation of the start codons in one or both of uORFs (uORF1 or uORF2) could significantly increase the expression of the downstream reporter gene. The start codon mutation in uORF1 produced a higher reporter gene expression than that in uORF2, indicating that the uORF1 could be a stronger inhibitor than the uORF2, and the length of uORFs seemed not to be crucial for down-regulating translation. The expression of both uORFs could co-regulate the associated gene expression. Substituting the rare codons in uORF1, uORF2 or both with less rare codons dramatically increased the expression of the downstream reporter gene. Rare codon mutations in both uORFs were much more efficient in up-regulating the associate gene expression than mutations in either of the two uORFs alone.
Subject(s)
Baculoviridae/physiology , Gene Expression Regulation, Viral , Open Reading Frames , Protein Biosynthesis , Viral Proteins/biosynthesis , Animals , Artificial Gene Fusion , Baculoviridae/genetics , Cell Line , Codon , Genes, Reporter , Lepidoptera , Luciferases/biosynthesis , Luciferases/geneticsABSTRACT
Nogo-B is a known regulator of neural functions and plays an important role in cell adhesion and migration. To our knowledge, the molecular mechanism behind its regulation of cell motility is still unknown. Here, we identified Fibulin-5, a secreted extracellular matrix protein, as a binding partner of Nogo-B. Using HeLa cells as a model, we found that Nogo-B and Fibulin-5 co-localize in the cytoplasm and plasma membrane. Furthermore, in HeLa cells that overexpress Nogo-B, cell migration and invasion was promoted by the elevated secretion of Fibulin-5. Thus, identification of the Nogo-B binding protein Fibulin-5 may contribute to uncover the pathway in which Nogo-B regulates tumor cell movement.
Subject(s)
Extracellular Matrix Proteins/metabolism , Myelin Proteins/metabolism , Cell Adhesion , Cell Nucleus/metabolism , Cytoplasm/metabolism , Endoplasmic Reticulum/metabolism , Extracellular Matrix Proteins/genetics , HeLa Cells , Humans , Myelin Proteins/genetics , Nogo Proteins , Protein TransportABSTRACT
The inhibitor of apoptosis proteins (IAP) plays an important role in cell apoptosis. We cloned two novel IAP family members, Ap-iap1 and Ap-iap2, from Antheraea pernyi nucleopolyhedrovirus (ApNPV) genome. Ap-IAP1 contains two baculoviral IAP repeat (BIR) domains followed by a RING domain, but Ap-IAP2 has only one BIR domain and RING. The result of transient expression in Spodoptera frugiperda (Sf21) showed that Ap-iap1 blocked cell apoptosis induced by actinomycin D treatment and also rescued the p35 deficient Autographa californica nucleopolyhedrovirus (AcNPV) to replicate in Sf9 cells, while Ap-iap2 does not have this function. Several Ap-IAP1 truncations were constructed to test the activity of BIRs or RING motif to inhibit cell apoptosis. The results indicated that BIRs or RING of Ap-IAP1 had equally function to inhibit cell apoptosis. Therefore deletion of above both of the above domains could not block apoptosis induced by actinomycin D or rescue the replication of AcMNPV Delta p35. We also screened two phage-display peptides that might interact with Ap-IAP1.
Subject(s)
Inhibitor of Apoptosis Proteins/physiology , Moths/virology , Nucleopolyhedroviruses/pathogenicity , Viral Proteins/physiology , Virulence Factors/physiology , Amino Acid Motifs , Amino Acid Sequence , Animals , Cell Line , Cloning, Molecular , Inhibitor of Apoptosis Proteins/genetics , Molecular Sequence Data , Sequence Alignment , Sequence Deletion , Spodoptera/virology , Viral Proteins/genetics , Virulence Factors/geneticsABSTRACT
Here, we show that heat shock cognate protein 70 (Hsc70) in shrimp cells can inhibit apoptosis induced by white spot syndrome virus (WSSV) infection. Caspase-3 protease activity of hemocytes increased significantly, correlating with a reduction in endogenous Hsc70 late in WSSV infection. Hsc70 dsRNA caused a significant increase in caspase-3 activity in the hemocytes of non-infected shrimp and WSSV-infected shrimp. We propose that upregulation of Hsc70 expression early in WSSV infection may also be used to prevent premature apoptotic cell death, and the precipitous downregulation of Hsc70 late in WSSV infection may lead to the timed induction of apoptosis.
Subject(s)
Apoptosis/physiology , Gene Expression Regulation, Viral/physiology , HSC70 Heat-Shock Proteins/metabolism , Nimaviridae/metabolism , Animals , Benzimidazoles , Caspase 3/metabolism , Cells, Cultured , Gene Silencing , HSC70 Heat-Shock Proteins/genetics , Hemocytes/virology , Hemolymph , Nimaviridae/genetics , Penaeidae/cytology , RNA, Viral , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
orf390 (WSSV449) is a novel apoptosis inhibitor gene in the genome of the White Spot Syndrome Virus (WSSV). In the present study, we focus on the function of orf390 gene. Stable expression of orf390 prevented SF9 insect cells from undergoing actinomycin D-induced apoptosis. ORF390 also rescued the replication of a p35-deficient-mutant (AcMNPVDeltap35k/pol+) in SF9 cells. In addition, ORF390 inhibits the activities of caspase-3 and -9 in vivo and in vitro. Here we demonstrate that the anti-apoptotic activity of ORF390 is dependent on two putative caspase-9 cleavage sites (VETD233 downward arrowG and LEHD303 downward arrowG) and one caspase-3 cleavage site (DEVD272 downward arrowG). Our results support the conclusion that these three sites play a key role in the suppression of apoptosis mediated by ORF390. These data further suggest that orf390 encodes a novel anti-apoptotic protein involved in cell survival and apoptosis regulation.
Subject(s)
Genes, Viral , Viral Proteins/metabolism , White spot syndrome virus 1/metabolism , Animals , Caspase Inhibitors , Cell Line , Humans , Viral Proteins/genetics , White spot syndrome virus 1/geneticsABSTRACT
Subtilisin QK, a new fibrinolytic enzyme, could cleave directly cross-linked fibrin in vitro. To verify the thrombolytic function of Subtilisin QK in vivo, the thrombolytic effect of purified Subtilisin QK on tail-thrombus of mouse was investigated. After injected with carrageenan, the tail-thrombus of Subtilisin QK treated group were shorter than the physiological saline treated group. Moreover, the tail-thrombus decreased correlate with Subtilisin QK in a dose-dependent manner. Thrombus nearly disappeared while the mice were treated with 12000 IU Subtilisin QK. The result indicated that Subtilisin QK significantly inhibited thrombus formation in mouse tail. This study made more foundation for further development of Subtilisin QK as a novel bifunctional thrombolytic agent.
Subject(s)
Carrageenan/toxicity , Disease Models, Animal , Fibrinolytic Agents/therapeutic use , Subtilisins/therapeutic use , Thrombosis/drug therapy , Thrombosis/enzymology , Animals , Dose-Response Relationship, Drug , Humans , Male , Mice , Thrombosis/chemically inducedABSTRACT
Early events in white spot syndrome virus (WSSV) morphogenesis, particularly the formation of viral membranes, are poorly understood. The major envelope proteins of WSSV are VP28, VP26, VP24, and VP19. Our previous results indicated that VP28 interacts with VP26 and VP24. In the present study, we used coimmunoprecipitation assays and pull-down assays to confirm that the four major proteins in the WSSV envelope can form a multiprotein complex. Yeast two-hybrid assays were also used to test for interactions among the four proteins. In summary, three pairwise protein interactions (VP19-VP28, VP19-VP24, and VP24-VP26) and one self-association (VP24-VP24) were identified for the first time.
Subject(s)
Viral Envelope Proteins/metabolism , White spot syndrome virus 1/metabolism , Protein Binding , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Viral Envelope Proteins/genetics , White spot syndrome virus 1/geneticsABSTRACT
White spot syndrome virus (WSSV) is one of the most devastating pathogens of shrimps and other crustaceans. In a previous study, we demonstrated that the major envelope protein VP28 of WSSV was involved in the attachment and penetration into shrimp cells. Here we showed that heat-shock cognate protein 70 (Hsc70) of shrimp was a binding partner of VP28 during virus infection. Hsc70 expression was enhanced by WSSV infection at the early stage and peaked at 12h post-infection and decreased drastically at the late stage. In shrimp haemocytes, both VP28 and Hsc70 proteins localized in the cytoplasm and their association was specific, ATP-dependent and Hsc70 concentration dependent. Moreover, direct VP28-Hsc70 association required both ATPase domain and peptide binding domain of Hsc70. The data obtained will help elucidate the role of VP28 protein in the process of virus infection.
Subject(s)
Adenosine Triphosphate/metabolism , HSC70 Heat-Shock Proteins/metabolism , Penaeidae/virology , Viral Envelope Proteins/metabolism , White spot syndrome virus 1/physiology , Animals , Cytoplasm/metabolism , Cytoplasm/virology , Gene Expression Profiling , Gene Expression Regulation , Hemocytes/metabolism , Protein Binding , Recombinant Proteins/metabolism , Time Factors , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
Pygopus, a very important component of the Wnt signaling transcriptional complex, has multiple functions in both Wnt-dependent and -independent pathways. Human Pygopus2 (Pygo2) is expressed in many cancers and plays an important role in tumor growth. In the present study, we generated human carcinoma (HeLa) cell lines stably expressing Pygo2, which counteracts vinblastine- induced apoptosis. The anti-apoptotic function was determined by DNA fragmentation, sub-G1 appearance, loss of mitochondrial membrane potential (Deltapsim) and the activation of caspase-9 and caspase-3. In addition, we found that Pygo2 effectively blocks vinblastineinduced c-Jun and AP-1 activation, maintains the anti-apoptotic protein Bcl-2 in an unphosphorylated state, and thus can render cells resistant to apoptosis. However, Pygo2 does not alter the vinblastine-induced cell cycle changes. Here, we describe an anti-apoptotic activity exerted by Pygo2 through blocking activation of the JNK/AP-1 signaling pathway induced by vinblastine.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Gene Expression , Intracellular Signaling Peptides and Proteins/metabolism , Vinblastine/pharmacology , Blotting, Western , Caspase 3/drug effects , Caspase 3/genetics , Caspase 9/drug effects , Caspase 9/genetics , Gene Deletion , HeLa Cells , Humans , Intracellular Signaling Peptides and Proteins/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effectsABSTRACT
Cytokine-induced suppressor of cytokine signaling (SOCS) proteins function as feedback inhibitors of cytokine receptor signaling by inhibiting the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signal transduction pathway. In this report, microtubule-associated protein 1S (MAP1), a member of the MAP1 family, was identified as a novel SOCS3 interacting protein. MAP1S could bind with microtubules and actin, and decorated and stabilized microtubules. A perinuclear co-localization was discovered between MAP1S and SOCS3. In MAP1S deficient macrophages, inhibition of SOCS3 on STAT3 phosphorylation can be partially hindered in the presence of interleukin-6 (IL-6) and lipopolysaccharide (LPS). The microtubule-depolymerizing drug nocodazole also disrupted the inhibitory activity of the SOCS3 protein. These results suggest that the interaction of SOCS3 with MAP1S and the integrity of the microtubule cytoskeleton play an important role in the negative regulation of SOCS3 on IL-6 signaling.
Subject(s)
Interleukin-6/metabolism , Microtubule-Associated Proteins/metabolism , Microtubules/metabolism , Suppressor of Cytokine Signaling Proteins/antagonists & inhibitors , Suppressor of Cytokine Signaling Proteins/metabolism , Cell Line , Cytoskeleton/metabolism , Humans , Immunoprecipitation , Microtubule-Associated Proteins/genetics , Protein Structure, Tertiary , Signal Transduction , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Two-Hybrid System TechniquesABSTRACT
The hypothesis that white-spot syndrome virus (WSSV) generates its envelope in the nucleoplasm is based on electron microscopy observations; however, as yet there is no direct evidence for this. In the present study, the lipids of WSSV and the nuclei of its host, the crayfish Procambarus clarkii, were extracted and the neutral lipid and phospholipid contents were analysed by high-performance liquid chromatography, thin-layer chromatography and gas chromatography/mass spectrometry. Phosphatidylcholine (PC) and phosphatidylethanolamine comprised 62.9 and 25.8 %, respectively, of WSSV phospholipids, whereas they comprised 58.5 and 30 %, respectively, of crayfish nuclei phospholipids. These two phospholipids were the dominant phospholipids, and amounts of other phospholipids were very low in the total WSSV and crayfish nuclei phospholipids. The data indicate that the phospholipid profile of WSSV and crayfish nuclei are similar, which is in agreement with the model that the lipids of WSSV are from the host-cell nuclei. However, the fatty acid chains of PC were different between the WSSV virions and crayfish nuclei, and the viral neutral lipid component was also found to be somewhat more complicated than that of the host nuclei. The number of species of cholesterol and hydrocarbon in virus neutral lipid was increased compared with that in host-cell nuclei neutral lipid. It is suggested that the differences between WSSV and its host are either due to selective sequestration of lipids or reflect the fact that the lipid metabolism of the host is changed by WSSV infection.
Subject(s)
Astacoidea/virology , Lipids/analysis , White spot syndrome virus 1/chemistry , White spot syndrome virus 1/physiology , Animals , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Gas Chromatography-Mass Spectrometry , Signal Transduction , Virion/isolation & purification , White spot syndrome virus 1/isolation & purification , White spot syndrome virus 1/pathogenicityABSTRACT
TRAF6 is an E3 ubiquitin ligase that transduces signals from members of the TLR/IL-1R family. Multiple molecules have been found to associate with TRAF6 and exert their functions in this pathway. Herein, by yeast two-hybrid screen using TRAF6 as bait, we identified PP4 as a potential TRAF6-interacting protein. PP4 physically interacted with TRAF6 and was recruited to TLR4 complex upon LPS stimulation. PP4 negatively regulated LPS-induced and TRAF6-mediated NF-kappaB activation by inhibiting the ubiquitination of TRAF6. LPS stimulation also induced the expression of PP4. Taken together, our findings suggest that PP4 is a negative feedback regulator of LPS/TLR4 pathway.
Subject(s)
Lipopolysaccharides/immunology , Phosphoprotein Phosphatases/metabolism , TNF Receptor-Associated Factor 6/metabolism , Toll-Like Receptor 4/immunology , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Animals , Cell Line , Feedback, Physiological , Humans , Mice , NF-kappa B/metabolism , Phosphoprotein Phosphatases/antagonists & inhibitors , Phosphoprotein Phosphatases/genetics , TNF Receptor-Associated Factor 6/genetics , Two-Hybrid System Techniques , Ubiquitin-Protein Ligases/geneticsABSTRACT
OBJECTIVE: In China, comparatively little research has been directed at serogroup B meningococci, which are mainly isolated from healthy individuals. We attempted to study the genotypic characterization of Neisseria meningitidis serogroup B strains. METHODS: We analyzed 150 N. meningitidis strains isolated in China during 1975-2005 by multilocus sequence typing (MLST) and porA typing. RESULTS: A total of 88 different sequence types (STs) were identified by MLST, 73 of which were newly identified. Seven complexes previously identified in other countries and three unique clonal lineages first identified in China were detected, seven of which had previously been described as 'hyperinvasive meningococcal lineages'. Several lineages were found in specified period. A total of 63 different porA types were found, 11 of which were novel. The most common porA types were P1.5-1,2-2 (17 isolates), P1.5-1,10-4 (12 isolates), P1.5-2,2-2 (eight isolates) and P1.7-2,4 (seven isolates). CONCLUSION: In this context, serogroup B meningococci provide a diverse, continually reassorted gene pool from which new genotypes arise. The most important mechanism is probably horizontal genetic exchange among N. meningitidis serogroup B strains, possibly resulting in the emergence of new meningococcal clones. These results may help our understanding of the genotypic distribution of serogroup B meningococci and provide clues for further study of this organism.