Use of an Immobilized Monoclonal Antibody to Examine Integrin α5β1 Signaling Independent of Cell Spreading

Cell attachment to the extracellular matrix (ECM) engages integrin signaling into the cell, but part of the signaling response also stem from cell spreading (3). To analyze specific integrin signaling-mediated responses independent of cell spreading, we developed a method engaging integrin signaling by use of an immobilized anti-integrin monoclonal antibody (mab) directed against the fibronectin (FN) receptor integrin α5β1. ECV 304 cells were plated onto FN or immobilized mab JBS5 (anti-integrin α5β1) or onto poly-L-lysin (P-L-L), which mediates integrin-independent attachment. Cells attached and spread on FN, while cells on JBS5 or P-L-L attached but did not spread. Importantly, plating onto FN or mab JBS5 gave rise to identical integrin-induced responses, including a down-regulation of the cyclin-dependent kinase (Cdk2) inhibitors p21(CIP1) and p27(KIP1), while attachment to P-L-L did not. We conclude that engagement of the FN-receptor integrin α5β1 induces integrin signaling regulating the Cdk2-inhibitors independent of cell spreading and present a method for how integrin signaling can be analyzed separate from the effects of cell spreading

The Microfloral Analysis of Secondary Caries Biofilm around Class I and Class II Composite and Amalgam Fillings

<p>Abstract</p> <p>Background</p> <p>Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. The diversity of the bacterial sources and the different types of filling materials could play a role in secondary caries. The aim of this study was to determine and compare the microbial spectrum of secondary caries biofilms around amalgam and composite resin restorations.</p> <p>Methods</p> <p>Clinical samples were collected from freshly extracted teeth diagnosed with clinical secondary caries. Samples were categorized into four groups according to the types of restoration materials and the classification of the cavity. Biofilms were harvested from the tooth-restoration interface using a dental explorer and after dilution were incubated on special agars. The bacteria were identified using the biochemical appraisal system. Statistical calculations were carried out using SPSS11.5 software to analyze the prevalence of the bacteria involved in secondary caries.</p> <p>Results</p> <p>Samples from a total of four groups were collected: two groups were collected from amalgam restorations, each had 21 samples from both Class I and Class II caries; and the other two groups were from composite resin restorations, each had 13 samples from both class I and class II caries. Our results showed: (1) Anaerobic species were dominant in both restoration materials. (2) In terms of the types of individual bacteria, no significant differences were found among the four groups according to the geometric mean of the detected bacteria (P > 0.05). However, there were significant differences among the detected bacteria within each group (P < 0.05). The composition of each bacterium had no statistical difference among the four groups (P > 0.05), but showed significant differences among the detected bacteria in each group (P < 0.05). (3) Among the four groups, there were no significant differences for the detection rate of each bacterium (P > 0.05), however, the detection rate of each bacterium within each group was statistically different among the detected bacteria (P < 0.05).</p> <p>Conclusions</p> <p>The proportion of obligatory anaerobic species was much greater than the facultative anaerobic species in the biofilm of secondary caries. Statistically, the materials of restoration and the location of secondary caries did not show any significant effects on the composition of the microflora.</p

Type III Nrg1 Back Signaling Enhances Functional TRPV1 along Sensory Axons Contributing to Basal and Inflammatory Thermal Pain Sensation

Type III Nrg1, a member of the Nrg1 family of signaling proteins, is expressed in sensory neurons, where it can signal in a bi-directional manner via interactions with the ErbB family of receptor tyrosine kinases (ErbB RTKs) [1]. Type III Nrg1 signaling as a receptor (Type III Nrg1 back signaling) can acutely activate phosphatidylinositol-3-kinase (PtdIns3K) signaling, as well as regulate levels of α7* nicotinic acetylcholine receptors, along sensory axons [2]. Transient receptor potential vanilloid 1 (TRPV1) is a cation-permeable ion channel found in primary sensory neurons that is necessary for the detection of thermal pain and for the development of thermal hypersensitivity to pain under inflammatory conditions [3]. Cell surface expression of TRPV1 can be enhanced by activation of PtdIns3K [4], [5], [6], making it a potential target for regulation by Type III Nrg1. We now show that Type III Nrg1 signaling in sensory neurons affects functional axonal TRPV1 in a PtdIns3K-dependent manner. Furthermore, mice heterozygous for Type III Nrg1 have specific deficits in their ability to respond to noxious thermal stimuli and to develop capsaicin-induced thermal hypersensitivity to pain. Cumulatively, these results implicate Type III Nrg1 as a novel regulator of TRPV1 and a molecular mediator of nociceptive function

Schizophrenia-associated HapICE haplotype is associated with increased NRG1 type III expression and high nucleotide diversity

Excitement and controversy have followed neuregulin (NRG1) since its discovery as a putative schizophrenia susceptibility gene; however, the mechanism of action of the associated risk haplotype (HapICE) has not been identified, and specific genetic variations, which may increase risk to schizophrenia have remained elusive. Using a postmortem brain cohort from 37 schizophrenia cases and 37 controls, we resequenced upstream of the type I–IV promoters, and the HapICE repeat regions in intron 1. Relative abundance of seven NRG1 mRNA transcripts in the prefrontal cortex were determined and compared across diagnostic and genotypic groups. We identified 26 novel DNA variants and showed an increased novel variant load in cases compared with controls (χ2=7.815; P=0.05). The average nucleotide diversity (θ=10.0 × 10−4) was approximately twofold higher than that previously reported for BDNF, indicating that NRG1 may be particularly prone to genetic change. A greater nucleotide diversity was observed in the HapICE linkage disequilibrium block in schizophrenia cases (θ(case)=13.2 × 10−4; θ(control)=10.0 × 10−4). The specific HapICE risk haplotype was associated with increased type III mRNA (F=3.76, P=0.028), which in turn, was correlated with an earlier age of onset (r=−0.343, P=0.038). We found a novel intronic five-SNP haplotype ∼730 kb upstream of the type I promoter and determined that this region functions as transcriptional enhancer that is suppressed by SRY. We propose that the HapICE risk haplotype increases expression of the most brain-abundant form of NRG1, which in turn, elicits an earlier clinical presentation, thus providing a novel mechanism through which this genetic association may increase risk of schizophrenia

Regulation of DNA Repair Mechanism in Human Glioma Xenograft Cells both In Vitro and In Vivo in Nude Mice

Glioblastoma Multiforme (GBM) is the most lethal form of brain tumor. Efficient DNA repair and anti-apoptotic mechanisms are making glioma treatment difficult. Proteases such as MMP9, cathepsin B and urokinase plasminogen activator receptor (uPAR) are over expressed in gliomas and contribute to enhanced cancer cell proliferation. Non-homologous end joining (NHEJ) repair mechanism plays a major role in double strand break (DSB) repair in mammalian cells.Here we show that silencing MMP9 in combination with uPAR/cathepsin B effects NHEJ repair machinery. Expression of DNA PKcs and Ku70/80 at both mRNA and protein levels in MMP9-uPAR (pMU) and MMP9-cathepsin B (pMC) shRNA-treated glioma xenograft cells were reduced. FACS analysis showed an increase in apoptotic peak and proliferation assays revealed a significant reduction in the cell population in pMU- and pMC-treated cells compared to untreated cells. We hypothesized that reduced NHEJ repair led to DSBs accumulation in pMU- and pMC-treated cells, thereby initiating cell death. This hypothesis was confirmed by reduced Ku70/Ku80 protein binding to DSB, increased comet tail length and elevated γH2AX expression in treated cells compared to control. Immunoprecipitation analysis showed that EGFR-mediated lowered DNA PK activity in treated cells compared to controls. Treatment with pMU and pMC shRNA reduced the expression of DNA PKcs and ATM, and elevated γH2AX levels in xenograft implanted nude mice. Glioma cells exposed to hypoxia and irradiation showed DSB accumulation and apoptosis after pMU and pMC treatments compared to respective controls.Our results suggest that pMU and pMC shRNA reduce glioma proliferation by DSB accumulation and increase apoptosis under normoxia, hypoxia and in combination with irradiation. Considering the radio- and chemo-resistant cancers favored by hypoxia, our study provides important therapeutic potential of MMP9, uPAR and cathepsin B shRNA in the treatment of glioma from clinical stand point

Effect of atorvastatin on C-reactive protein and benefits for cardiovascular disease in patients with type 2 diabetes: analyses from the Collaborative Atorvastatin Diabetes Trial

CARDS was partially funded by Diabetes UK and the National Health Service Research and Development Forum (England)

Trends in incidence of childhood cancer in Australia, 1983–2006

Cancer risk is increased substantially in adult kidney transplant recipients, but the long-term risk of cancer in childhood recipients is unclear. Using the Australian and New Zealand Dialysis and Transplant Registry, the authors compared overall and site-specific incidences of cancer after transplantation in childhood recipients with population-based data by using standardized incidence ratios (SIRs). Among 1734 childhood recipients (median age 14 years, 57% male, 85% white), 289 (16.7%) developed cancer (196 nonmelanoma skin cancers, 143 nonskin cancers) over a median follow-up of 13.4 years. The 25-year cumulative incidences of any cancer were 27% (95% confidence intervals 24-30%), 20% (17-23%) for nonmelanoma skin cancer, and 14% (12-17%) for nonskin cancer (including melanoma). The SIR for nonskin cancer was 8.23 (95% CI 6.92-9.73), with the highest risk for posttransplant lymphoproliferative disease (SIR 45.80, 95% CI 32.71-62.44) and cervical cancer (29.4, 95% CI 17.5-46.5). Increasing age at transplantation (adjusted hazard ratio [aHR] per year 1.10, 95% CI 1.06-1.14), white race (aHR 3.36, 95% CI 1.61-6.79), and having a functioning transplant (aHR 2.27, 95% CI 1.47-3.71) were risk factors for cancer. Cancer risk, particularly for virus-related cancers, is increased substantially after kidney transplantation during childhood

Rho-kinase-dependent F-actin rearrangement is involved in the inhibition of PI3-kinase/Akt during ischemia–reperfusion-induced endothelial cell apoptosis

Activation of cytoskeleton regulator Rho-kinase during ischemia–reperfusion (I/R) plays a major role in I/R injury and apoptosis. Since Rho-kinase is a negative regulator of the pro-survival phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway, we hypothesized that inhibition of Rho-kinase can prevent I/R-induced endothelial cell apoptosis by maintaining PI3-kinase/Akt activity and that protective effects of Rho-kinase inhibition are facilitated by prevention of F-actin rearrangement. Human umbilical vein endothelial cells were subjected to 1 h of simulated ischemia and 1 or 24 h of simulated reperfusion after treatment with Rho-kinase inhibitor Y-27632, PI3-kinase inhibitor wortmannin, F-actin depolymerizers cytochalasinD and latrunculinA and F-actin stabilizer jasplakinolide. Intracellular ATP levels decreased following I/R. Y-27632 treatment reduced I/R-induced apoptosis by 31% (P < 0.01) and maintained Akt activity. Both effects were blocked by co-treatment with wortmannin. Y-27632 treatment prevented the formation of F-actin bundles during I/R. Similar results were observed with cytochalasinD treatment. In contrast, latrunculinA and jasplakinolide treatment did not prevent the formation of F-actin bundles during I/R and had no effect on I/R-induced apoptosis. Apoptosis and Akt activity were inversely correlated (R2 = 0.68, P < 0.05). In conclusion, prevention of F-actin rearrangement by Rho-kinase inhibition or by cytochalasinD treatment attenuated I/R-induced endothelial cell apoptosis by maintaining PI3-kinase and Akt activity

Complete Sequencing of the blaNDM-1-Positive IncA/C Plasmid from Escherichia coli ST38 Isolate Suggests a Possible Origin from Plant Pathogens

The complete sequence of the plasmid pNDM-1_Dok01 carrying New Delhi metallo-β-lactamase (NDM-1) was determined by whole genome shotgun sequencing using Escherichia coli strain NDM-1_Dok01 (multilocus sequence typing type: ST38) and the transconjugant E. coli DH10B. The plasmid is an IncA/C incompatibility type composed of 225 predicted coding sequences in 195.5 kb and partially shares a sequence with blaCMY-2-positive IncA/C plasmids such as E. coli AR060302 pAR060302 (166.5 kb) and Salmonella enterica serovar Newport pSN254 (176.4 kb). The blaNDM-1 gene in pNDM-1_Dok01 is terminally flanked by two IS903 elements that are distinct from those of the other characterized NDM-1 plasmids, suggesting that the blaNDM-1 gene has been broadly transposed, together with various mobile elements, as a cassette gene. The chaperonin groES and groEL genes were identified in the blaNDM-1-related composite transposon, and phylogenetic analysis and guanine-cytosine content (GC) percentage showed similarities to the homologs of plant pathogens such as Pseudoxanthomonas and Xanthomonas spp., implying that plant pathogens are the potential source of the blaNDM-1 gene. The complete sequence of pNDM-1_Dok01 suggests that the blaNDM-1 gene was acquired by a novel composite transposon on an extensively disseminated IncA/C plasmid and transferred to the E. coli ST38 isolate