58 research outputs found
Scottish care leavers covenant & agenda for change : what's the big idea?
[no abstract available
Monitoring the dynamics of Src activity in response to anti-invasive dasatinib treatment at a subcellular level using dual intravital imaging
Optimising response to tyrosine kinase inhibitors in cancer remains an extensive field of research. Intravital imaging is an emerging tool, which can be used in drug discovery to facilitate and fine-tune maximum drug response in live tumors. A greater understanding of intratumoural delivery and pharmacodynamics of a drug can be obtained by imaging drug target-specific fluorescence resonance energy transfer (FRET) biosensors in real time. Here, we outline our recent work using a Src-FRET biosensor as a readout of Src activity to gauge optimal tyrosine kinase inhibition in response to dasatinib treatment regimens in vivo. By simultaneously monitoring both the inhibition of Src using FRET imaging, and the modulation of the surrounding extracellular matrix using second harmonic generation (SHG) imaging, we were able to show enhanced drug penetrance and delivery to live pancreatic tumors. We discuss the implications of this dual intravital imaging approach in the context of altered tumor-stromal interactions, while summarising how this approach could be applied to assess other combination strategies or tyrosine kinase inhibitors in a preclinical setting
Polarized cell motility induces hydrogen peroxide to inhibit cofilin via cysteine oxidation
Mesenchymal cell motility is driven by polarized actin polymerization [1]. Signals at the leading edge recruit actin polymerization machinery to promote membrane protrusion, while matrix adhesion generates tractive force to propel forward movement. To work effectively, cell motility is regulated by a complex network of signaling events that affect protein activity and localization. H2O2 has an important role as a diffusible second messenger [2], and mediates its effects through oxidation of cysteine thiols. One cell activity influenced by H2O2 is motility [3]. However, a lack of sensitive and H2O2-specific probes for measurements in live cells has not allowed for direct observation of H2O2 accumulation in migrating cells or protrusions. In addition, the identities of proteins oxidized by H2O2 that contribute to actin dynamics and cell motility have not been characterized. We now show, as determined by fluorescence lifetime imaging microscopy, that motile cells generate H2O2 at membranes and cell protrusions and that H2O2 inhibits cofilin activity through oxidation of cysteines 139 (C139) and 147 (C147). Molecular modeling suggests that C139 oxidation would sterically hinder actin association, while the increased negative charge of oxidized C147 would lead to electrostatic repulsion of the opposite negatively charged surface. Expression of oxidation-resistant cofilin impairs cell spreading, adhesion, and directional migration. These findings indicate that H2O2 production contributes to polarized cell motility through localized cofilin inhibition and that there are additional proteins oxidized during cell migration that might have similar roles
In and Beyond the Care Setting : Relationships Between Young People and Care Workers: A Literature Review
This review seeks to identify and summarise findings from literature about the nature of relationships that develop between older children and young people, and those caring for them within and beyond residential and fostering settings. We make particular efforts to include studies that gather the views of young people themselves. We consider the issues and challenges that young people face in moving on from care, the type of support they receive during this process, and focus on the relational elements of this support. The study as a whole focuses on young people in adolescence as they approach the point where they will leave care and undertake the transition towards more independent living. The review will briefly outline the background and policy context, before discussing some of the key themes found in the literature. ⢠Part 1 explores the issues facing young people leaving care and the need for more targeted, specialist support. ⢠Part 2 discusses the importance of relationships for young people leaving care and the growing interest in relationship-based practice. ⢠Part 3 explores various aspects of relationships valued by care leavers. ⢠Part 4 looks at relationships in different types of care settings
Development of an inducible mouse model of iRFP713 to track recombinase activity and tumour development in vivo
While the use of bioluminescent proteins for molecular imaging is a powerful technology to further our understanding of complex processes, fluorescent labeling with visible light fluorescent proteins such as GFP and RFP suffers from poor tissue penetration and high background autofluorescence. To overcome these limitations, we generated an inducible knock-in mouse model of iRFP713. This model was used to assess Cre activity in a Rosa Cre-ER background and quantify Cre activity upon different tamoxifen treatments in several organs. We also show that iRFP can be readily detected in 3D organoid cultures, FACS analysis and in vivo tumour models. Taken together we demonstrate that iRFP713 is a progressive step in in vivo imaging and analysis that widens the optical imaging window to the near-infrared spectrum, thereby allowing deeper tissue penetration, quicker image acquisition without the need to inject substrates and a better signal to background ratio in genetically engineered mouse models (GEMMs)
ROCK signaling promotes collagen remodeling to facilitate invasive pancreatic ductal adenocarcinoma tumor cell growth
Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer death; identifying PDAC enablers may reveal potential therapeutic targets. Expression of the actomyosin regulatory ROCK1 and ROCK2 kinases increased with tumor progression in human and mouse pancreatic tumors, while elevated ROCK1/ROCK2 expression in human patients, or conditional ROCK2 activation in a KrasG12D/p53R172H mouse PDAC model, was associated with reduced survival. Conditional ROCK1 or ROCK2 activation promoted invasive growth of mouse PDAC cells into threeâdimensional collagen matrices by increasing matrix remodeling activities. RNA sequencing revealed a coordinated program of ROCKâinduced genes that facilitate extracellular matrix remodeling, with greatest foldâchanges for matrix metalloproteinases (MMPs) Mmp10 and Mmp13. MMP inhibition not only decreased collagen degradation and invasion, but also reduced proliferation in threeâdimensional contexts. Treatment of KrasG12D/p53R172H PDAC mice with a ROCK inhibitor prolonged survival, which was associated with increased tumorâassociated collagen. These findings reveal an ancillary role for increased ROCK signaling in pancreatic cancer progression to promote extracellular matrix remodeling that facilitates proliferation and invasive tumor growth
Targeting the LOX/hypoxia axis reverses many of the features that make pancreatic cancer deadly: inhibition of LOX abrogates metastasis and enhances drug efficacy
Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancerârelated mortality. Despite significant advances made in the treatment of other cancers, current chemotherapies offer little survival benefit in this disease. Pancreaticoduodenectomy offers patients the possibility of a cure, but most will die of recurrent or metastatic disease. Hence, preventing metastatic disease in these patients would be of significant benefit. Using principal component analysis (PCA), we identified a LOX/hypoxia signature associated with poor patient survival in resectable patients. We found that LOX expression is upregulated in metastatic tumors from Pdx1âCre KrasG12D/+ Trp53R172H/+ (KPC) mice and that inhibition of LOX in these mice suppressed metastasis. Mechanistically, LOX inhibition suppressed both migration and invasion of KPC cells. LOX inhibition also synergized with gemcitabine to kill tumors and significantly prolonged tumorâfree survival in KPC mice with earlyâstage tumors. This was associated with stromal alterations, including increased vasculature and decreased fibrillar collagen, and increased infiltration of macrophages and neutrophils into tumors. Therefore, LOX inhibition is able to reverse many of the features that make PDAC inherently refractory to conventional therapies and targeting LOX could improve outcome in surgically resectable disease
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Pulmonary environmental cues drive group 2 innate lymphoid cell dynamics in mice and humans
Group 2 innate lymphoid cells (ILC2s) are enriched in mucosal tissues (e.g., lung) and respond to epithelial cellâderived cytokines initiating type 2 inflammation. During inflammation, ILC2 numbers are increased in the lung. However, the mechanisms controlling ILC2 trafficking and motility within inflamed lungs remain unclear and are crucial for understanding ILC2 function in pulmonary immunity. Using several approaches, including lung intravital microscopy, we demonstrate that pulmonary ILC2s are highly dynamic, exhibit amoeboid-like movement, and aggregate in the lung peribronchial and perivascular spaces. They express distinct chemokine receptors, including CCR8, and actively home to CCL8 deposits located around the airway epithelium. Within lung tissue, ILC2s were particularly motile in extracellular matrixâenriched regions. We show that collagen-I drives ILC2 to markedly change their morphology by remodeling their actin cytoskeleton to promote environmental exploration critical for regulating eosinophilic inflammation. Our study provides previously unappreciated insights into ILC2 migratory patterns during inflammation and highlights the importance of environmental guidance cues in the lung in controlling ILC2 dynamics
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