3,032 research outputs found
Mesenchymal stem cells expressing TRAIL lead to tumour growth inhibition in an experimental lung cancer model
AbstractLung cancer is a major public health problem in the western world, and gene therapy strategies to tackle this disease systemically are often impaired by inefficient delivery of the vector to the tumour tissue. Some of the main factors inhibiting systemic delivery are found in the blood stream in the form of red and white blood cells (WBCs) and serum components. Mesenchymal stem cells (MSCs) have been shown to home to tumour sites and could potentially act as a shield and vehicle for a tumouricidal gene therapy vector. Here, we describe the ability of an adenoviral vector expressing TRAIL (Ad.TR) to transduce MSCs and show the apoptosis‐inducing activity of these TRAIL‐carrying MSCs on A549 lung carcinoma cells. Intriguingly, using MSCs transduced with Ad.enhanced‐green‐fluorescent‐protein (EGFP) we could show transfer of viral DNA to cocultured A549 cells resulting in transgenic protein production in these cells, which was not inhibited by exposure of MSCs to human serum containing high levels of adenovirus neutralizing antibodies. Furthermore, Ad.TR‐transduced MSCs were shown not to induce T‐cell proliferation, which may have resulted in cytotoxic T‐cell‐mediated apoptosis induction in the Ad.TR‐transduced MSCs. Apoptosis was also induced in A549 cells by Ad.TR‐transduced MSCs in the presence of physiological concentrations of WBC, erythrocytes and sera from human donors that inhibit or neutralize adenovirus alone. Moreover, we could show tumour growth reduction with TRAIL‐loaded MSCs in an A549 xenograft mouse model. This is the first study that demonstrates the potential therapeutic utility of Ad.TR‐transduced MSCs in cancer cells and the stability of this vector in the context of the blood environment.</jats:p
A non-apoptotic role for caspase-9 in muscle differentiation
Caspases, a family of cysteine proteases most often investigated for their roles in apoptosis, have also been demonstrated to have functions that are vital for the efficient execution of cell differentiation. One such role that has been described is the requirement of caspase-3 for the differentiation of skeletal myoblasts into myotubes but, as yet, the mechanism leading to caspase-3 activation in this case remains elusive. Here, we demonstrate that caspase-9, an initiator caspase in the mitochondrial death pathway, is responsible for the activation of caspase-3 in differentiating C2C12 cells. Reduction of caspase-9 levels, using an shRNA construct, prevented caspase-3 activation and inhibited myoblast fusion. Myosin-heavy-chain expression, which accompanies myoblastic differentiation, was not caspase-dependent. Overexpression of Bcl-xL, a protein that inhibits caspase-9 activation, had the same effect on muscle differentiation as knockdown of caspase-9. These data suggest that the mitochondrial pathway is required for differentiation; however, the release of cytochrome c or Smac (Diablo) could not be detected, raising the possibility of a novel mechanism of caspase-9 activation during muscle differentiation.</jats:p
Caspase-10: a molecular switch from cell-autonomous apoptosis to communal cell death in response to chemotherapeutic drug treatment.
The mechanisms of how chemotherapeutic drugs lead to cell cycle checkpoint regulation and DNA damage repair are well understood, but how such signals are transmitted to the cellular apoptosis machinery is less clear. We identified a novel apoptosis-inducing complex, we termed FADDosome, which is driven by ATR-dependent caspase-10 upregulation. During FADDosome-induced apoptosis, cFLIPL is ubiquitinated by TRAF2, leading to its degradation and subsequent FADD-dependent caspase-8 activation. Cancer cells lacking caspase-10, TRAF2 or ATR switch from this cell-autonomous suicide to a more effective, autocrine/paracrine mode of apoptosis initiated by a different complex, the FLIPosome. It leads to processing of cFLIPL to cFLIPp43, TNF-α production and consequently, contrary to the FADDosome, p53-independent apoptosis. Thus, targeting the molecular levers that switch between these mechanisms can increase efficacy of treatment and overcome resistance in cancer cells.Cell Death and Differentiation advance online publication, 3 November 2017; doi:10.1038/cdd.2017.164
DR4 specific TRAIL variants are more efficacious than wild-type TRAIL in pancreatic cancer
Current treatment modalities for pancreatic carcinoma afford only modest survival benefits. TRAIL, as a potent and specific inducer of apoptosis in cancer cells, would be a promising new treatment option. However, since not all pancreatic cancer cells respond to TRAIL, further improvements and optimizations are still needed. One strategy to improve the effectiveness of TRAIL-based therapies is to specifically target one of the 2 cell death inducing TRAILreceptors, TRAIL-R1 or TRAIL-R2 to overcome resistance. To this end, we designed constructs expressing soluble TRAIL (sTRAIL) variants that were rendered specific for either TRAIL-R1 or TRAIL-R2 by amino acid changes in the TRAIL ectodomain. When we expressed these constructs, including wild-type sTRAIL (sTRAILwt), TRAIL-R1 (sTRAILDR4) and TRAIL-R2 (sTRAILDR5) specific variants, in 293 producer cells we found all to be readily expressed and secreted into the supernatant. These supernatants were subsequently transferred onto target cancer cells and apoptosis measured. We found that the TRAIL-R1 specific variant had higher apoptosis-inducing activity in human pancreatic carcinoma Colo357 cells as well as PancTu1 cells that were additionally sensitized by targeting of XIAP. Finally, we tested TRAIL-R1 specific recombinant TRAIL protein (rTRAILDR4) on Colo357 xenografts in nude mice and found them to be more efficacious than rTRAILwt. Our results demonstrate the benefits of synthetic biological approaches and show that TRAIL-R1 specific variants can potentially enhance the therapeutic efficacy of TRAIL-based therapies in pancreatic cancer, suggesting that they can possibly become part of individualized and tumor speci fic combination treatments in the future
Mucosal protection by phosphatidylcholine
The colonic mucus serves a first barrier towards invasion of commensal bacteria in stools to prevent inflammation. One essential component of intestinal mucus is phosphatidylcholine (PC) which represents more than 90% of the phospholipids in mucus indicative for a selective transport of PC into this compartment. It is arranged in lamellar structures as surfactant-like particles which provide a hydrophobic surface on top of the hydrated mucus gel to prevent the invasion of bacteria from intestinal lumen. In ulcerative colitis (UC), the mucus PC content is reduced by 70%, irrespective of the state of inflammation. Thus, it could represent an intrinsic primary pathogenetic condition predisposing to bacterial invasion and the precipitation of inflammation. Since PC was shown to be mainly secreted by the ileal mucosa from where it is assumed to move distally to the colon, the PC content along the colonic wall towards the rectum gradually thins, with the least PC content in the rectum. This explains the start of the clinical manifestation of UC in the rectum and the expansion from there to the upper parts of the colon. In three clinical trials, when missing mucus PC in UC was supplemented by an oral, delayed release PC preparation, the inflammation improved and even resolved after a 3-month treatment course. The data indicate the essential role of the mucus PC content for protection against inflammation in colon. Copyright (C) 2012 S. Karger AG, Base
Relaciones de género y poder en la política. La configuración de las prácticas políticas en la Unión Cívica Radical y el Partido Justicialista de Misiones entre 1983 y 2003. 16H260
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A közösségi anyagcsere vizsgálata anaerob deklorináció során = Investigations on the community metabolism in anaerobe dechlorination
A rövidszénláncú alifás klórozott szénhidrogének gyakori talajvízszennyezők hazánkban. A perklóretén, triklóretén biológiai bontása hatékony folyamat, mégis nagy sebességkülönbségek jellemzők különböző szennyezett területeken. A reduktív deklorinációban a klórozott vegyületek elektronakceptorok, elektrondonor a hidrogén, vagy kis molekulatömegű szerves vegyületek. A folyamat elindulásához a deklorináló baktériumoknak felül kell kerekedniük a kompetítor mikrobákon, amelyek szintén hidrogént és szerves vegyületeket hasznosítanak. Szennyezett területekről származó mikrobaközösségek szerkezetét, tagjainak szerepét laboratóriumi körülmények között polifázikus módszerekkel vizsgáltuk, új molekuláris technikákat vezettünk be a mikrobák közötti anyagcsere-kapcsolatok megértésére. Megállapítottuk, hogy sikeres deklorináló közösségben jellemző a Dehalococcoides ethenogenes dominanciája; a mikrobiális diverzitás csökkenése. A lebontás folyamatát fermentáló szervezetek jelenléte lassítja, akárcsak a kometabolikus partnerek gátlása. Hatékony bontás során biofilm kialakulása jellmező és elengedhetetlen kellő mennyiségű hozzáférhető szerves anyag jelenléte. Négy új módszert (MDA, SNuPE, SEM és FISH) optimáltunk a deklorináló mikroba közösség vizsgálatára. Megállapítottuk, hogy a valós aktivitással jobban korreláló RNS alapú vizsgálatok szükségesek a deklorinációban résztvevő mikrobiális kapcsolatok feltárásához. | Chlorinated short chain aliphatic hydrocarbons are common groundwater pollutants in Hungary. Biological decomposition of perchloroethene and trichloroethene is effective process, though speed of decomposition extremely differ in different sites. At reductive dechlorination chlorinated hydrocarbons serve as electron acceptors, H2 or small organic compounds act as donors. At startup of degradation dechlorinating microbes have to outcompete compeptitor microbes utilising similarly H2 and organic compounds. Microbial communities originating from different polluted sites and the role of their members in the community dechlorinating metabolism were investigated under controlled laboratory microcosm experiments using polyphasic approach, and by introducing new techniques. It could be determined that effective dechlorinating communities are characterised by the dominance of Dehalococcoides ethenogenes, and a simplification of the original diversity. The presence of fermenting microbes retards the speed of degradation; the inhibition of co-metabolic partners acts similarly. Effective degradation is characterised by Dehalococcoides spp. biofilm formation, and presence of adequte available organic compounds is indispensable. Four novel methods (MDA, SNuPE, SEM and FISH) were optimised for the investigation of dechlorinating communities. RNA based investigations better correlate real activities thus their use is indispensable in the investigation of microbial metabolic interactions
Object Detector Simulation for Certification of Autonomous Surface Vessels
Interessen for autonome fartøy i den maritime industrien har økt betydelig. For å sikre sikker drift av disse fartøyene, er sertifisering avgjørende. Dette innebærer omfattende testing av hver enkelt komponent i det autonome systemet, og systemet som helhet. En viktig komponent i et autonomt system er det eksterne situasjonsforståelse systemet, og spesielt målfølgingssystemet innenfor dette systemet. Målfølgingssystemet overvåker omgivelsene ved å koble sammen deteksjoner av objekter over tid og danne spor. Deteksjoner gjøres ved hjelp av sensorer og deteksjonsalgoritmer.
Fullskalatesting av målfølgingssystemene er en betydelig utfordring, grunnet behovet for omfattende mengder testdata. Det er dyrt og resurskrevende å skaffe ekte testdata, og det vil være vanskelig, om ikke umulig, å dekke alle viktige testsituasjoner. En alternativ tilnærming er å skaffe testdata gjennom simuleringer i syntetiske omgivelser. Simuleringer kan prioritere å gjenskape systemet på en nøyaktig måte eller prioritere effektivitet.
Denne oppgaven introduserer en ny og effektiv måte å simulere kamerabaserte objektdeteksjonssystemer i maritime omgivelser for å tilrettelegge for testing av målfølgingssystemer. Det utviklede systemet, Marine Object Detector Simulator (MODSIM), etterligner oppførselen til deteksjonssystemet og introduserer feil i deteksjoner ved hjelp av statistikk og statistiske fordelinger. Denne metoden eliminerer behovet for komplekse simuleringer av underliggende feilkilder. Systemet demonstreres ved å gjennomføre tre ulike simuleringer basert på statistiske parametere. Parameterne er basert på et ekte kamerabasert objektdeteksjonssystem som er trent på syntetisk data under forskjellige vær- og lysforhold.The potential of Autonomous Surface Vessels (ASV) has captured the attention of the maritime industry. For ASVs to operate safely, it is crucial to certify them. Certification involves testing each component of the autonomous system individually and as a complete system. One such component is the external Situational Awareness (SITAW) system, particularly the tracker within this system. A tracker monitors the environment by connecting detections of objects over time into tracks. Detections are obtained through sensors and object detection algorithms.
Conducting full-scale testing of trackers presents significant challenges due to the need for extensive test data. Obtaining real-life test data is costly and labour-intensive, and covering all significant operational scenarios would be difficult, if not impossible. An alternative approach for obtaining test data is through simulations. Simulations can replicate the system with high accuracy or prioritise computational efficiency. This thesis proposes a novel approach for efficiently simulating camera-based object detector output in maritime environments to enable tracker testing. The designed and developed system, Marine Object Detector Simulator (MODSIM), replicates the output behaviour of the detector and incorporates detector errors through statistics and statistical distributions. This approach eliminates the need for complex simulations of the underlying error causes. The viability of the system is assessed by performing three different simulations using statistical parameters. These parameters are based on a real camera-based object detector trained on a synthetic environment under various detection conditions
Development of a FACS-based Smac/DIABLO release assay to monitor individual drug responses and to pave the way towards patient-tailored therapies
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