On the pathophysiological significance of CD154/CD40-mediated leukocyte-endothelial cell interaction

CD154/CD40-Wechselwirkungen spielen sowohl bei der humoralen als auch der zellulären Immunantwort eine entscheidende Rolle. Eine Beteiligung von CD40/CD154 an der Pathogenese chronisch entzündlicher Darmerkrankungen (CED) konnte sowohl durch eine Untersuchung der Expression beider Proteine in der Mukosa von Patienten als auch durch die Wirksamkeit von anti-CD154-Antikörpern in vivo gezeigt werden. Aufgrund schwerer Nebenwirkungen, insbesondere thromboembolischer Komplikationen, kann jedoch die Gabe blockierender anti-CD154-Antikörpern nicht als vielversprechender therapeutischer Ansatz angesehen werden. In dieser Arbeit haben wir untersucht, inwieweit ein alternativer Ansatz, die Unterdrückung der Expression von CD40 durch spezifische antisense-Oligonukleotide (asODN), für die Therapie von CED wirksam sein könnte. Um asODN gegen CD40 aus der Ratte generieren zu können, wurde das Gen zunächst kloniert und sequenziert. Nach dem Design verschiedener spezifischer asODN konnte eines, rAS3, in vitro wirksam war. In kultivierten glatten Gefäßmuskelzellen aus der Aorta der Ratte konnte rAS3 sowohl die Expression von CD40 hemmen als auch CD40-induzierte Genexpression unterdrücken. Um das therapeutische Potential von rAS3 in vivo zu untersuchen, wurde das TNBS-Colitis Modell der Ratte etabliert. Eine einzelne rektale Injektion einer liposomalen Formulierung von rAS3, aber nicht die eines Oligonukleotides anderer Sequenz, konnte die Entwicklung einer Colitis in TNBS-behandelten Ratten für mindestens eine Woche signifikant hemmen: makroskopisch und histologisch war der Zustand behandelter Tiere deutlich verbessert. Die Infiltration der Mukosa mit Leukozyten war im Vergleich zu Kontrolltieren erniedrigt, möglicherweise aufgrund der niedrigen Expression des Zelladhäsionsmoleküls VCAM-1 (RT-PCR-Analyse). Um schließlich die Übertragbarkeit der im Rattenmodell gewonnen Ergebnisse auf den Menschen zu prüfen, wurde die Wirksamkeit verschiedener spezifischer humaner asODN gegen CD40 in kultivierten humanen Endothelzellen gezeigt. Die in dieser Studie gewonnenen Ergebnisse zeigen, dass gegen CD40 gerichtete asODN CD40/CD154-Wechselwirkungen in vitro und in vivo potent und spezifisch unterbinden. Humane asODN gegen CD40 könnten somit eine interessante Plattform für die Therapie chronisch entzündlicher Erkrankungen, darunter Morbus Crohn bieten. Vorteil dieses Ansatzes wäre neben der kostengünstigen Herstellung vor allem die einfache lokale Applikation die eine Vermeidung der obengenannten Nebenwirkungen ermöglichen könnte

CAPRI and RASAL impose different modes of information processing on Ras due to contrasting temporal filtering of Ca(2+)

The versatility of Ca(2+) as a second messenger lies in the complex manner in which Ca(2+) signals are generated. How information contained within the Ca(2+) code is interpreted underlies cell function. Recently, we identified CAPRI and RASAL as related Ca(2+)-triggered Ras GTPase-activating proteins. RASAL tracks agonist-stimulated Ca(2+) oscillations by repetitively associating with the plasma membrane, yet CAPRI displays a long-lasting Ca(2+)-triggered translocation that is refractory to cytosolic Ca(2+) oscillations. CAPRI behavior is Ca(2+)- and C2 domain–dependent but sustained recruitment is predominantly Ca(2+) independent, necessitating integration of Ca(2+) by the C2 domains with agonist-evoked plasma membrane interaction sites for the pleckstrin homology domain. Using an assay to monitor Ras activity in real time, we correlate the spatial and temporal translocation of CAPRI with the deactivation of H-Ras. CAPRI seems to low-pass filter the Ca(2+) signal, converting different intensities of stimulation into different durations of Ras activity in contrast to the preservation of Ca(2+) frequency information by RASAL, suggesting sophisticated modes of Ca(2+)-regulated Ras deactivation

Discovery of Novel Human Breast Cancer MicroRNAs from Deep Sequencing Data by Analysis of Pri-MicroRNA Secondary Structures

MicroRNAs (miRNAs) are key regulators of gene expression and contribute to a variety of biological processes. Abnormal miRNA expression has been reported in various diseases including pathophysiology of breast cancer, where they regulate protumorigenic processes including vascular invasiveness, estrogen receptor status, chemotherapy resistance, invasion and metastasis. The miRBase sequence database, a public repository for newly discovered miRNAs, has grown rapidly with approximately >10,000 entries to date. Despite this rapid growth, many miRNAs have not yet been validated, and several others are yet to be identified. A lack of a full complement of miRNAs has imposed limitations on recognizing their important roles in cancer, including breast cancer. Using deep sequencing technology, we have identified 189 candidate novel microRNAs in human breast cancer cell lines with diverse tumorigenic potential. We further show that analysis of 500-nucleotide pri-microRNA secondary structure constitutes a reliable method to predict bona fide miRNAs as judged by experimental validation. Candidate novel breast cancer miRNAs with stem lengths of greater than 30 bp resulted in the generation of precursor and mature sequences in vivo. On the other hand, candidates with stem length less than 30 bp were less efficient in producing mature miRNA. This approach may be used to predict which candidate novel miRNA would qualify as bona fide miRNAs from deep sequencing data with approximately 90% accuracy

Controversies around epithelial-mesenchymal plasticity in cancer metastasis

Experimental evidence accumulated over decades has implicated epithelial–mesenchymal plasticity (EMP), which collectively encompasses epithelial–mesenchymal transition and the reverse process of mesenchymal–epithelial transition, in tumour metastasis, cancer stem cell generation and maintenance, and therapeutic resistance. However, the dynamic nature of EMP processes, the apparent need to reverse mesenchymal changes for the development of macrometastases and the likelihood that only minor cancer cell subpopulations exhibit EMP at any one time have made such evidence difficult to accrue in the clinical setting. In this Perspectives article, we outline the existing preclinical and clinical evidence for EMP and reflect on recent controversies, including the failure of initial lineage-tracing experiments to confirm a major role for EMP in dissemination, and discuss accumulating data suggesting that epithelial features and/or a hybrid epithelial–mesenchymal phenotype are important in metastasis. We also highlight strategies to address the complexities of therapeutically targeting the EMP process that give consideration to its spatially and temporally divergent roles in metastasis, with the view that this will yield a potent and broad class of therapeutic agents.See 'additional link' for access to a free to read version of the article.</p

3D Interconnected V6O13 Nanosheets Grown on Carbonized Textile via a Seed-Assisted Hydrothermal Process as High-Performance Flexible Cathodes for Lithium-Ion Batteries

Abstract Three-dimensional (3D) free-standing nanostructured materials have been proven to be one of the most promising electrodes for energy storage due to their enhanced electrochemical performance. And they are also widely studied for the wearable energy storage systems. In this work, interconnected V6O13 nanosheets were grown on the flexible carbonized textile (c-textile) via a seed-assisted hydrothermal method to form a 3D free-standing electrode for lithium-ion batteries (LIBs). The electrode exhibited a specific capacity of 170 mA h g−1 at a specific current of 300 mA g−1. With carbon nanotube (CNT) coating, its specific capacities further increased 12–40% at the various current rates. It could retain a reversible capacity of 130 mA h g−1, 74% of the initial capacity after 300 cycles at the specific current of 300 mA g−1. It outperformed most of the mixed-valence vanadium oxides. The improved electrochemical performance was ascribed to the synergistic effect of the 3D nanostructure of V6O13 for feasible Li+ diffusion and transport and highly conductive hierarchical conductive network formed by CNT and carbon fiber in c-textile

Matrix Metalloproteinase 14 promotes lung cancer by cleavage of Heparin-Binding EGF-like Growth Factor

Molecularly targeted therapies benefit approximately 15–20% of non-small cell lung cancer (NSCLC) patients carrying specific drug-sensitive mutations. Thus, there is a clinically unmet need for the identification of novel targets for drug development. Here, we performed RNA-deep sequencing to identify altered gene expression between malignant and non-malignant lung tissue. Matrix Metalloproteinase 14 (MMP14), a membrane-bound proteinase, was significantly up-regulated in the tumor epithelial cells and intratumoral myeloid compartments in both mouse and human NSCLC. Overexpression of a soluble dominant negative MMP14 (DN-MMP14) or pharmacological inhibition of MMP14 blocked invasion of lung cancer cells through a collagen I matrix in vitro and reduced tumor incidence in an orthotopic K-RasG12D/+p53−/− mouse model of lung cancer. Additionally, MMP14 activity mediated proteolytic processing and activation of Heparin-Binding EGF-like Growth Factor (HB-EGF), stimulating the EGFR signaling pathway to increase proliferation and tumor growth. This study highlights the potential for development of therapeutic strategies that target MMP14 in NSCLC with particular focus on MMP14-HB-EGF axis