647 research outputs found

    IL-17B Can Impact on Endothelial Cellular Traits Linked to Tumour Angiogenesis

    Get PDF
    IL-17B is a member of the IL-17 cytokine family which have been implicated in inflammatory response and autoimmune diseases such as rheumatoid arthritis. The founding member of this family, IL-17 (or IL-17A), has also been implicated in promoting tumour angiogenesis through the induction of other proangiogenic factors. Here we examine the potential of recombinant human IL-17B to contribute to the angiogenic process. In vitro rhIL-17B was able to inhibit HECV endothelial cell-matrix adhesion and cellular migration and also, at higher concentrations, could substantially reduce tubule formation compared to untreated HECV cells in a Matrigel tubule formation assay. This data suggests that IL-17B may act in an antiangiogenic manner

    Erythrocyte enrichment in hematopoietic progenitor cell cultures based on magnetic susceptibility of the hemoglobin

    Get PDF
    Using novel media formulations, it has been demonstrated that human placenta and umbilical cord blood-derived CD34+ cells can be expanded and differentiated into erythroid cells with high efficiency. However, obtaining mature and functional erythrocytes from the immature cell cultures with high purity and in an efficient manner remains a significant challenge. A distinguishing feature of a reticulocyte and maturing erythrocyte is the increasing concentration of hemoglobin and decreasing cell volume that results in increased cell magnetophoretic mobility (MM) when exposed to high magnetic fields and gradients, under anoxic conditions. Taking advantage of these initial observations, we studied a noninvasive (label-free) magnetic separation and analysis process to enrich and identify cultured functional erythrocytes. In addition to the magnetic cell separation and cell motion analysis in the magnetic field, the cell cultures were characterized for cell sedimentation rate, cell volume distributions using differential interference microscopy, immunophenotyping (glycophorin A), hemoglobin concentration and shear-induced deformability (elongation index, EI, by ektacytometry) to test for mature erythrocyte attributes. A commercial, packed column high-gradient magnetic separator (HGMS) was used for magnetic separation. The magnetically enriched fraction comprised 80% of the maturing cells (predominantly reticulocytes) that showed near 70% overlap of EI with the reference cord blood-derived RBC and over 50% overlap with the adult donor RBCs. The results demonstrate feasibility of label-free magnetic enrichment of erythrocyte fraction of CD34+ progenitor-derived cultures based on the presence of paramagnetic hemoglobin in the maturing erythrocytes. © 2012 Jin et al

    Identification of a novel O-conotoxin reveals an unusual and potent inhibitor of the human α9α10 nicotinic acetylcholine receptor

    Get PDF
    Conotoxins are a pool of disulfide-rich peptide neurotoxins produced by cone snails for predation and defense. They are a rich reservoir of novel ligands for ion channels, neurotransmitter receptors and transporters in the nervous system. In this study, we identified a novel conotoxin component, O-conotoxin GeXXVIIA, from the venom of Conus generalis. The native form of this component is a disulfide-linked homodimer of a 5-Cys-containing peptide. Surprisingly, our electrophysiological studies showed that, in comparison to the folded monomers, the linear peptide of this toxin had the highest inhibitory activity at the human α9α10 nicotinic acetylcholine receptor (nAChR), with an IC50 of 16.2 ± 1.4 nM. The activities of the N-terminal and C-terminal halves of the linear toxin are markedly reduced compared with the full-length toxin, suggesting that the intact sequence is required to potently inhibit the hα9α10 nAChR. α9α10 nAChRs are expressed not only in the nervous system, but also in a variety of non-neuronal cells, such as cochlear hair cells, keratinocytes, epithelial and immune cells. A potent inhibitor of human α9α10 nAChRs, such as GeXXVIIA, would facilitate unraveling the functions of this nAChR subtype. Furthermore, this unusual nAChR inhibitor may lead to the development of novel α9α10 nAChR-targeting drugs

    Activation of miR-9 by human papillomavirus in cervical cancer

    Get PDF
    Cervical cancer is the third most common cancer in women worldwide, leading to about 300,000 deaths each year. Most cervical cancers are caused by human papillomavirus (HPV) infection. However, persistent transcriptional activity of HPV oncogenes, which indicates active roles of HPV in cervical cancer maintenance and progression, has not been well characterized. Using our recently developed assays for comprehensive profiling of HPV E6/E7 transcripts, we have detected transcriptional activities of 10 high-risk HPV strains from 87 of the 101 cervical tumors included in the analysis. These HPV-positive patients had significantly better survival outcome compared with HPV-negative patients, indicating HPV transcriptional activity as a favorable prognostic marker for cervical cancer. Furthermore, we have determined microRNA (miRNA) expression changes that were correlated with tumor HPV status. Our profiling and functional analyses identified miR-9 as the most activated miRNA by HPV E6 in a p53-independent manner. Further target validation and functional studies showed that HPV-induced miR-9 activation led to significantly increased cell motility by downregulating multiple gene targets involved in cell migration. Thus, our work helps to understand the molecular mechanisms as well as identify potential therapeutic targets for cervical cancer and other HPV-induced cancers

    A novel lid-covering peptide inhibitor of nicotinic acetylcholine receptors derived from αd-conotoxin GeXXA

    Get PDF
    Nicotinic acetylcholine receptors (nAChRs) play a fundamental role in nervous signal transmission, therefore various antagonists and agonists are highly desired to explore the structure and function of nAChRs. Recently, a novel dimeric αD-conotoxin GeXXA was identified to inhibit nAChRs by binding at the top surface of the receptors, and the monomeric C-terminal domain (CTD) of αD-GeXXA retains some inhibitory activity. In this study, the internal dimeric N-terminal domain (NTD) of this conopeptide was further investigated. We first developed a regio-selective protection strategy to chemically prepare the anti-parallel dimeric NTD, and found that the isolated NTD part of GeXXA possesses the nAChR-inhibitory activity, the subtype-dependence of which implies a preferred binding of NTD to the β subunits of nAChR. Deletion of the NTD N-terminal residues did not affect the activity of NTD, indicating that the N-terminus is not involved in the interaction with nAChRs. By optimizing the sequence of NTD, we obtained a fully active single-chain cyclic NTD, based on which 4 Arg residues were found to interact with nAChRs. These results demonstrate that the NTD part of αD-GeXXA is a lid-covering nAChR inhibitor, displaying a novel inhibitory mechanism distinct from other allosteric ligands of nAChRs

    Chemokines as Potential Biomarkers for PTSD in Military Population

    Get PDF
    Post-traumatic stress disorder (PTSD) is a serious mental health concern worldwide among civilians and military personnel. Gaps in our understanding of its biological basis create significant obstacles for accurate diagnosis and assessment of therapeutic interventions. In light of this, investigation of biological factors associated with possible molecular cues of inflammation or neuroimmune disorders, could provide new surrogate markers for PTSD or PTSD treatment response. Analyses to date in deployed military personnel have suggested that sets of chemokines may be useful as biomarkers for PTSD acquired in military operations. Specifically, studies to date suggest that CCL2, CCL15, CCL22, CCL25, CXCL2, and CXCL12 are associated with PTSD onset, while CCL13, CCL20, and CXCL6 are correlated to PTSD risk; CX3CL1 are associated with resilience; CCL3; CXCL11, and CXCL16 are associated with stress response. CCL11, CCL13, CCL20, and CCL25 are correlated with the severity of PTSD symptoms. This chapter reviews the current understanding of potential chemokine markers for PTSD, and the potential chemokines associated with PTSD onset, risk, resilience, as well as stress responses in service members. Although the proposed biomarkers require further validation, these findings may lead to additional knowledge for the education and development of diagnostic and therapeutic approaches for PTSD, not only benefiting military personnel, but civilians as well

    Surface passivation of carbon nanoparticles with branched macromolecules influences near infrared bioimaging

    Get PDF
    A superior and commercially exploitable 'green synthesis' of optically active carbon nanoparticle (OCN) is revealed in this work. The naked carbon particles (<20 nm) were derived from commercial food grade honey. The fluorescence properties of these particles were significantly enhanced by utilizing hyberbranched polymer for surface passivation. A dramatic increase in near infrared emission was achieved compared to a linear polymer (PEG) coated carbon nanoparticles. Interestingly, as passivating agent becomes more extensively branched (pseudo generation 2 to 4), the average radiant efficiency amplifies considerably as a direct result of the increasing surface area available for light passivation. The particles showed negligible loss of cell viability in presence of endothelial cells in vitro. Preliminary in vivo experiment showed high contrast enhancement in auxiliary lymphnode in a mouse model. The exceptionally rapid lymphatic transport of these particles suggests that such an approach may offer greater convenience and reduced procedural expense, as well as improved surgical advantage as the patient is positioned on the table for easier resection

    A Family of microRNAs Encoded by Myosin Genes Governs Myosin Expression and Muscle Performance

    Get PDF
    SummaryMyosin is the primary regulator of muscle strength and contractility. Here we show that three myosin genes, Myh6, Myh7, and Myh7b, encode related intronic microRNAs (miRNAs), which, in turn, control muscle myosin content, myofiber identity, and muscle performance. Within the adult heart, the Myh6 gene, encoding a fast myosin, coexpresses miR-208a, which regulates the expression of two slow myosins and their intronic miRNAs, Myh7/miR-208b and Myh7b/miR-499, respectively. miR-208b and miR-499 play redundant roles in the specification of muscle fiber identity by activating slow and repressing fast myofiber gene programs. The actions of these miRNAs are mediated in part by a collection of transcriptional repressors of slow myofiber genes. These findings reveal that myosin genes not only encode the major contractile proteins of muscle, but act more broadly to influence muscle function by encoding a network of intronic miRNAs that control muscle gene expression and performance

    Posttraumatic Stress Disorder Biomarker — p11

    Get PDF
    Post-traumatic stress disorder (PTSD) is a chronic and disabling anxiety disorder associated with a traumatic event [1]. It is linked to increased risk of suicide and deficits in social functioning [2, 3]. Despite extensive study in psychiatry, the underlying mechanisms of PTSD are still poorly understood [4, 5]. Currently, the diagnosis for PTSD is based on clinical observation and symptom checklist [4, 6-8] and no laboratory blood-based tests. Although biomarker discovery for PTSD is not easy [8], a reliable biomarker would significantly impact the diagnosis and therapeutic monitoring of PTSD. Developing interventions to identify and treat PTSD requires objective approaches to determining the presence of PTSD [8]. Substantial data indicate several potential biomarkers for PTSD. Of these candidate markers, p11 (S100A10) has been studied in PTSD animal models [7] and in human subjects with PTSD [6]. We found that p11 is over-expressed in both animal models and post-mortem brains of subjects with PTSD [7]. Incorporating testing of p11, a novel biomarker for PTSD, into clinical practice, along with more subjective measures, such as participants’ medical history, mental status, duration of symptoms, and symptom checklist or self-report, would provide additional power to predict impending PTSD. In this chapter, we discuss the biomarker concept and the potential clinical utility of PTSD biomarkers. We further discuss the potential of p11 as a PTSD biomarker and as a tool that may enhance PTSD diagnosis and intervention in health care practice
    • …
    corecore