Search results for "TYR"

Epithelial-to-mesenchymal transition in the context of epidermal growth factor receptor inhibition in non-small-cell lung cancer

2018

The identification of oncogenic driver mutations in non-small-cell lung cancer (NSCLC) has led to the development of targeted drugs. Tyrosine kinase inhibitors (TKIs) directed against the epidermal growth factor receptor (EGFR) target lung tumours bearing EGFR-activating mutations. This new therapeutic strategy has greatly improved tumour response rates. However, drug resistance invariably occurs during TKI-based treatment. Epithelial-to-mesenchymal transition (EMT) is one of the resistance mechanisms identified in EGFR-mutated NSCLC treated with TKIs. In this review we gather together the most important findings on this phenomenon in relation to cancer stem cells and cancer epigenetics. We…

FRI0014 Antioxidant role of microvesicles from adipose tissue-derived mesenchymal stem cells in human osteoarthritic chondrocytes

2017

Background Oxidative stress results in the disruption of normal physiologic signaling leading to inflammatory changes, cartilage degradation and osteoarthritis (OA) progression (1). Recent advances have revealed the role of cell-derived microvesicles (MV) as a new mechanism of cell-to-cell communication with potential therapeutic applications. We have shown previously the antiinflammatory effects of human adipose tissue-derived mesenchymal stem cells (AD-MSC) conditioned medium in OA chondrocytes (2). Objectives We have isolated the MV fraction from the secretome of AD-MSC to investigate its activity on oxidative stress and inflammation in OA chondrocytes stimulated with interleukin (IL)-1β…

2018

Chardonnay wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by th…

Modern diversification of the amino acid repertoire driven by oxygen

2017

All extant life employs the same 20 amino acids for protein biosynthesis. Studies on the number of amino acids necessary to produce a foldable and catalytically active polypeptide have shown that a basis set of 7-13 amino acids is sufficient to build major structural elements of modern proteins. Hence, the reasons for the evolutionary selection of the current 20 amino acids out of a much larger available pool have remained elusive. Here, we have analyzed the quantum chemistry of all proteinogenic and various prebiotic amino acids. We find that the energetic HOMO-LUMO gap, a correlate of chemical reactivity, becomes incrementally closer in modern amino acids, reaching the level of specialize…

Are glutamate and asparagine necessary for tyrosinase activity of type-3 copper proteins?

2018

Abstract Type-3 copper proteins (T3CPs) are complex proteins which share similar active sites. Two copper atoms (CuA and CuB) bind dioxygen as a peroxide in a side on coordination. This protein family comprises the enzymes tyrosinase and catechol oxidase as well as the oxygen transporter hemocyanin. T3CPs occur in almost all organisms and exhibit a number of essential functions. In particular, they are involved in all kinds of enzymatic browning reactions and immune defense. The chemical basis of the two catalytic processes, i.e., the o-hydroxylation of monophenols and the two-electron oxidation to o-quinones, is still discussed. Investigations on natural enzymes with known crystal structur…

Alterations in Tight- and Adherens-Junction Proteins Related to Glaucoma Mimicked in the Organotypically Cultivated Mouse Retina Under Elevated Press…

2020

Purpose To scrutinize alterations in cellular interactions and cell signaling in the glaucomatous retina, mouse retinal explants were exposed to elevated pressure. Methods Retinal explants were prepared from C57bl6 mice and cultivated in a pressure chamber under normotensive (atmospheric pressure + 0 mm Hg), moderately elevated (30 mm Hg), and highly elevated (60 mm Hg) pressure conditions. The expression levels of proteins involved in the formation of tight junctions (zonula occludens 1 [ZO-1], occludin, and claudin-5) and adherens junctions (VE-cadherin and β-catenin) and in cell-signaling cascades (Cdc42 and activated Cdc42 kinase 1 [ACK1]), as well as the expression levels of the growth…

Nitric oxide/cGMP signaling via guanylyl cyclase isoform 1 modulates glutamate and GABA release in somatosensory cortex of mice

2017

Abstract In hippocampus, two guanylyl cyclases (NO-GC1 and NO-GC2) are involved in the transduction of the effects of nitric oxide (NO) on synaptic transmission. However, the respective roles of the NO-GC isoforms on synaptic transmission are less clear in other regions of the brain. In the present study, we used knock-out mice deficient for the NO-GC1 isoform (NO-GC1 KO) to analyze its role in the glutamatergic and GABAergic neurotransmission at pyramidal neurons in layers II/III of somatosensory cortex. NO-GC1 KO slices revealed reduced frequencies of miniature excitatory- and inhibitory-postsynaptic currents, increased paired-pulse ratios and decreased input–output curves of evoked signa…

Bioactive Polyphenols from Pomegranate Juice Reduce 5-Fluorouracil-Induced Intestinal Mucositis in Intestinal Epithelial Cells

2020

Intestinal epithelial cells (IECs) play a pivotal role in maintaining intestinal homeostasis. Different noxious agents, among them also anticancer therapies, can impair intestinal epithelial integrity triggering inflammation and oxidative stress. A frequent complication of chemotherapy is gastrointestinal mucositis, strongly influencing the effectiveness of therapy, increasing healthcare costs, and impairing patients&rsquo

Genome-wide association meta-analysis for early age-related macular degeneration highlights novel loci and insights for advanced disease

2020

Abstract Background Advanced age-related macular degeneration (AMD) is a leading cause of blindness. While around half of the genetic contribution to advanced AMD has been uncovered, little is known about the genetic architecture of early AMD. Methods To identify genetic factors for early AMD, we conducted a genome-wide association study (GWAS) meta-analysis (14,034 cases, 91,214 controls, 11 sources of data including the International AMD Genomics Consortium, IAMDGC, and UK Biobank, UKBB). We ascertained early AMD via color fundus photographs by manual grading for 10 sources and via an automated machine learning approach for > 170,000 photographs from UKBB. We searched for early AMD loc…

Tyro3 Contributes to Retinal Ganglion Cell Function, Survival and Dendritic Density in the Mouse Retina

2020

Retinal ganglion cells (RGCs) are the only output neurons of the vertebrate retina, integrating signals from other retinal neurons and transmitting information to the visual centers of the brain. The death of RGCs is a common outcome in many optic neuropathies, such as glaucoma, demyelinating optic neuritis and ischemic optic neuropathy, resulting in visual defects and blindness. There are currently no therapies in clinical use which can prevent RGC death in optic neuropathies; therefore, the identification of new targets for supporting RGC survival is crucial in the development of novel treatments for eye diseases. In this study we identify that the receptor tyrosine kinase, Tyro3, is crit…