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Biomedical Engineering and Bioengineering Commons

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Full-Text Articles in Biomedical Engineering and Bioengineering

Targeting Ovarian Cancer And Endothelium With An Allosteric Ptp4a3 Phosphatase Inhibitor, Kelley E. Mcqueeney, Joseph M. Salamoun, James C. Burnett, Nektarios Barabutis, Paula Pekic, Sophie L. Lewandowski, Danielle C. Llaneza, Robert Cornelison, Yunpeng Bai, Zhong-Yin Zhang, John D. Catravas Jan 2018

Targeting Ovarian Cancer And Endothelium With An Allosteric Ptp4a3 Phosphatase Inhibitor, Kelley E. Mcqueeney, Joseph M. Salamoun, James C. Burnett, Nektarios Barabutis, Paula Pekic, Sophie L. Lewandowski, Danielle C. Llaneza, Robert Cornelison, Yunpeng Bai, Zhong-Yin Zhang, John D. Catravas

Bioelectrics Publications

Overexpression of protein tyrosine phosphatase PTP4A oncoproteins is common in many human cancers and is associated with poor patient prognosis and survival. We observed elevated levels of PTP4A3 phosphatase in 79% of human ovarian tumor samples, with significant overexpression in tumor endothelium and pericytes. Furthermore, PTP4A phosphatases appear to regulate several key malignant processes, such as invasion, migration, and angiogenesis, suggesting a pivotal regulatory role in cancer and endothelial signaling pathways. While phosphatases are attractive therapeutic targets, they have been poorly investigated because of a lack of potent and selective chemical probes. In this study, we disclose that a potent, …


Dielectric Properties Of Isolated Adrenal Chromaffin Cells Determined By Microfluidic Impedance Spectroscopy, A. C. Sabuncu, M. Stacey, G. L. Graviso, N. Semenova, P. T. Vernier, N. Leblanc, I. Chatterjee, J. Zaklit Jan 2018

Dielectric Properties Of Isolated Adrenal Chromaffin Cells Determined By Microfluidic Impedance Spectroscopy, A. C. Sabuncu, M. Stacey, G. L. Graviso, N. Semenova, P. T. Vernier, N. Leblanc, I. Chatterjee, J. Zaklit

Bioelectrics Publications

Knowledge of the dielectric properties of biological cells plays an important role in numerical models aimed at understanding how high intensity ultrashort nanosecond electric pulses affect the plasma membrane and the membranes of intracellular organelles. To this end, using electrical impedance spectroscopy, the dielectric properties of isolated, neuroendocrine adrenal chromaffin cells were obtained. Measured impedance data of the cell suspension, acquired between 1 kHz and 20 MHz, were fit into a combination of constant phase element and Cole-Cole models from which the effect of electrode polarization was extracted. The dielectric spectrum of each cell suspension was fit into a Maxwell-Wagner …


Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier Jan 2018

Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier

Bioelectrics Publications

Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with …


Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas Jan 2018

Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas

Bioelectrics Publications

Inflammation is the major cause of endothelial barrier hyper-permeability, associated with acute lung injury and acute respiratory distress syndrome. This study reports that p53 "orchestrates" the defence of vascular endothelium against LPS, by mediating the opposing actions of Rac1 and RhoA in pulmonary tissues. Human lung microvascular endothelial cells treated with HSP90 inhibitors activated both Rac1- and P21-activated kinase, which is an essential element of vascular barrier function. 17AAG increased the phosphorylation of both LIMK and cofilin, in contrast to LPS which counteracted those effects. Mouse lung microvascular endothelial cells exposed to LPS exhibited decreased expression of phospho-cofilin. 17AAG treatment …