@article{HanKampikGrehnetal.2013, author = {Han, Hong and Kampik, Daniel and Grehn, Franz and Schlunck, G{\"u}nther}, title = {TGF-beta 2-Induced Invadosomes in Human Trabecular Meshwork Cells}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0070595}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130074}, pages = {e70595}, year = {2013}, abstract = {Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of retinal ganglion cells and their optic nerve axons. It is associated with disturbed regulation of intraocular pressure, elevated intraocular levels of TGF-β2, aberrant extracellular matrix (ECM) deposition and increased outflow resistance in the trabecular meshwork (TM). The mechanisms underlying these changes are not fully understood. Cell-matrix interactions have a decisive role in TM maintenance and it has been suggested that TGF-β-induced inhibition of matrix metalloproteases may drive aberrant ECM deposition in POAG. Invadopodia and podosomes (invadosomes) are distinct sites of cell-matrix interaction and localized matrix-metalloprotease (MMP) activity. Here, we report on the effects of TGF-β2 on invadosomes in human trabecular meshwork cells. Human TM (HTM) cells were derived from donor tissue and pretreated with vehicle or TGF-β2 (2 ng/ml) for 3d. Invadosomes were studied in ECM degradation assays, protein expression and MMP-2 activity were assessed by western blot and zymography and ECM protein transcription was detected by RT-qPCR. HTM cells spontaneously formed podosomes and invadopodia as detected by colocalization of Grb2 or Nck1 to sites of gelatinolysis. Pretreatment with TGF-β2 enhanced invadosomal proteolysis and zymographic MMP-2 activity as well as MMP-2, TIMP-2 and PAI-1 levels in HTM cell culture supernatants. Rho-kinase inhibition by H1152 blocked the effects of TGF-β2. Concomitant transcription of fibronectin and collagens-1, -4 and -6 was increased by TGF-β2 and fibrillar fibronectin deposits were observed in areas of invadosomal ECM remodelling. In contrast to a current hypothesis, our data indicate that TGF-β2 induces an active ECM remodelling process in TM cells, characterized by concurrent increases in localized ECM digestion and ECM expression, rather than a mere buildup of material due to a lack of degradation. Invadosomal cell adhesion and signaling may thus have a role in POAG pathophysiology.}, language = {en} } @article{AdelfingerGentschevdeGuibertetal.2014, author = {Adelfinger, Marion and Gentschev, Ivaylo and de Guibert, Julio Grimm and Weibel, Stephanie and Langbein-Laugwitz, Johanna and H{\"a}rtl, Barbara and Escobar, Hugo Murua and Nolte, Ingo and Chen, Nanhai G. and Aguilar, Richard J. and Yu, Yong A. and Zhang, Qian and Frentzen, Alexa and Szalay, Aladar A.}, title = {Evaluation of a New Recombinant Oncolytic Vaccinia Virus Strain GLV-5b451 for Feline Mammary Carcinoma Therapy}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0104337}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119387}, pages = {e104337}, year = {2014}, abstract = {Virotherapy on the basis of oncolytic vaccinia virus (VACV) infection is a promising approach for cancer therapy. In this study we describe the establishment of a new preclinical model of feline mammary carcinoma (FMC) using a recently established cancer cell line, DT09/06. In addition, we evaluated a recombinant vaccinia virus strain, GLV-5b451, expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as an oncolytic agent against FMC. Cell culture data demonstrate that GLV-5b451 virus efficiently infected, replicated in and destroyed DT09/06 cancer cells. In the selected xenografts of FMC, a single systemic administration of GLV-5b451 led to significant inhibition of tumor growth in comparison to untreated tumor-bearing mice. Furthermore, tumor-specific virus infection led to overproduction of functional scAb GLAF-2, which caused drastic reduction of intratumoral VEGF levels and inhibition of angiogenesis. In summary, here we have shown, for the first time, that the vaccinia virus strains and especially GLV-5b451 have great potential for effective treatment of FMC in animal model.}, language = {en} } @article{SteinbrunnChatterjeeBargouetal.2014, author = {Steinbrunn, Torsten and Chatterjee, Manik and Bargou, Ralf C. and St{\"u}hmer, Thorsten}, title = {Efficient Transient Transfection of Human Multiple Myeloma Cells by Electroporation - An Appraisal}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0097443}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119616}, pages = {e97443}, year = {2014}, abstract = {Cell lines represent the everyday workhorses for in vitro research on multiple myeloma (MM) and are regularly employed in all aspects of molecular and pharmacological investigations. Although loss-of-function studies using RNA interference in MM cell lines depend on successful knockdown, no well-established and widely applied protocol for efficient transient transfection has so far emerged. Here, we provide an appraisal of electroporation as a means to introduce either short-hairpin RNA expression vectors or synthesised siRNAs into MM cells. We found that electroporation using siRNAs was much more efficient than previously anticipated on the basis of transfection efficiencies deduced from EGFP-expression off protein expression vectors. Such knowledge can even confidently be exploited in "hard-to-transfect" MM cell lines to generate large numbers of transient knockdown phenotype MM cells. In addition, special attention was given to developing a protocol that provides easy implementation, good reproducibility and manageable experimental costs.}, language = {en} } @article{TsonevaStritzkerBedenketal.2015, author = {Tsoneva, Desislava and Stritzker, Jochen and Bedenk, Kristina and Zhang, Qian and Cappello, Joseph and Fischer, Utz and Szalay, Aladar A.}, title = {Drug-encoded Biomarkers for Monitoring Biological Therapies}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {9}, doi = {10.1371/journal.pone.0137573}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125265}, pages = {e0137573}, year = {2015}, abstract = {Blood tests are necessary, easy-to-perform and low-cost alternatives for monitoring of oncolytic virotherapy and other biological therapies in translational research. Here we assessed three candidate proteins with the potential to be used as biomarkers in biological fluids: two glucuronidases from E. coli (GusA) and Staphylococcus sp. RLH1 (GusPlus), and the luciferase from Gaussia princeps (GLuc). The three genes encoding these proteins were inserted individually into vaccinia virus GLV-1h68 genome under the control of an identical promoter. The three resulting recombinant viruses were used to infect tumor cells in cultures and human tumor xenografts in nude mice. In contrast to the actively secreted GLuc, the cytoplasmic glucuronidases GusA and GusPlus were released into the supernatants only as a result of virus-mediated oncolysis. GusPlus resulted in the most sensitive detection of enzyme activity under controlled assay conditions in samples containing as little as 1 pg/ml of GusPlus, followed by GusA (25 pg/ml) and GLuc (≥375 pg/ml). Unexpectedly, even though GusA had a lower specific activity compared to GusPlus, the substrate conversion in the serum of tumor-bearing mice injected with the GusA-encoding virus strains was substantially higher than that of GusPlus. This was attributed to a 3.2 fold and 16.2 fold longer half-life of GusA in the blood stream compared to GusPlus and GLuc respectively, thus a more sensitive monitor of virus replication than the other two enzymes. Due to the good correlation between enzymatic activity of expressed marker gene and virus titer, we conclude that the amount of the biomarker protein in the body fluid semiquantitatively represents the amount of virus in the infected tumors which was confirmed by low light imaging. We found GusA to be the most reliable biomarker for monitoring oncolytic virotherapy among the three tested markers.}, language = {en} } @article{RadakovicReboredoHelmetal.2017, author = {Radakovic, D. and Reboredo, J. and Helm, M. and Weigel, T. and Sch{\"u}rlein, S. and Kupczyk, E. and Leyh, R. G. and Walles, H. and Hansmann, J.}, title = {A multilayered electrospun graft as vascular access for hemodialysis}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0185916}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159102}, pages = {e0185916}, year = {2017}, abstract = {Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access—an autogenous arteriovenous fistula—is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts.}, language = {en} }