Inhibition of K-RAS effectors like B-RAF or MEK1/2 is accompanied by treatment resistance in cancer patients via re-activation of PI3K and Wnt signaling. We hypothesized that myotubularin-related-protein-7 (MTMR7), which inhibits PI3K and ERK1/2 signaling downstream of RAS, directly targets RAS and thereby prevents resistance. Using cell and structural biology combined with animal studies, we show that MTMR7 binds and inhibits RAS at cellular membranes.
View Article and Find Full Text PDFPurpose: Postoperative quadriceps muscle strength was lowered after tourniquet application during total knee arthroplasty (TKA). Furthermore, tourniquet application results in higher proteolytic activity within vastus medialis cells, without influence on the amount and function of mitochondria. The effects of the commonly utilized intraoperative tourniquet on gene expression within the human skeletal muscle cells are barely examined.
View Article and Find Full Text PDFPurpose: Myeloid dendritic cells (MDC) decline significantly after multiple traumas which might be due to an increased migration into injured regions. Ubiquitin is released from dying cells and is increased in serum after trauma. Ubiquitin can bind to the chemokine receptor CXCR4.
View Article and Find Full Text PDFPurpose: Recent data suggest diminished post-operative quadriceps muscle strength after tourniquet application during total knee arthroplasty (TKA). The metabolic effects of the commonly utilized intraoperative tourniquet with consecutive ischaemia on the skeletal muscle cells were unknown. Ubiquitin proteasome system represents one of the main pathways involved in muscle protein breakdown contributing to muscle atrophy.
View Article and Find Full Text PDFCarbon monoxide (CO) abrogates TNF-α-mediated inflammatory responses in endothelial cells, yet the underlying mechanism thereof is still elusive. We have previously shown that the anti-inflammatory effect of CO-releasing molecule-3 (CORM-3) is not completely mediated via deactivation of the NF-κB pathway. In this study, we sought to explore other potential mechanisms by which CORM-3 downregulates VCAM-1 expression on TNF-α-stimulated HUVECs.
View Article and Find Full Text PDFBackground: Prolonged hypothermia, as occurs during solid organ transplantation, negatively influences transplantation outcome. Proteolysis is one of the deleterious events implicated in preservation injury of organ allografts. This strongly affects graft quality and hence immediate organ function.
View Article and Find Full Text PDFHyperpolarization-activated cyclic nucleotide-gated (HCN) channels contribute to stabilizing resting membrane potential, thus controlling neuron excitability. Subclasses of nociceptive neurons differ in their excitability, therefore, these channels could be a distinguishing marker. We investigated isolated dorsal root ganglion neurons from a non-rodent species, the pig, Sus scrofa domesticus.
View Article and Find Full Text PDFImmunol Cell Biol
February 2006
Recent findings suggest that extracellular ubiquitin has pleiotropic effects on host defence mechanisms, but its cellular mechanism of action is not yet understood. Using fluorescence and in vivo confocal microscopy, we observed uptake of N-terminal fluorescein-labelled ubiquitin into human PBMC and MonoMac 6 cells. Immunoblotting experiments indicated that extracellular ubiquitin is then rapidly conjugated to a multitude of intracellular proteins.
View Article and Find Full Text PDFThe ubiquitin system plays a crucial role in the immune system, and ubiquitylation is regarded as one of the most common posttranslational modifications of proteins. However, its regulation in human peripheral blood mononuclear cells during sepsis is unknown. Thus, we investigated cytosolic levels of free and conjugated ubiquitin and the total ubiquitylation rate in cell free extracts from healthy donors (n = 10) and patients (n = 10) with sepsis.
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