Siân-Eleri Owens

Siân-Eleri Owens
Swansea University | SWAN · Institute of Life Science "ILS"

PhD

About

27
Publications
6,109
Reads
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348
Citations
Additional affiliations
April 2008 - present
Swansea University
Position
  • Research Officer
September 2002 - September 2006
Cardiff University
Position
  • PhD Student
Description
  • PhD title Studies of myosin light chain-dependent modulation of tight junction function through the actions of membrane-permeant peptides

Publications

Publications (27)
Article
Full-text available
Many species of bacteria produce toxins such as cholesterol-dependent cytolysins that form pores in cell membranes. Membrane pores facilitate infection by releasing nutrients, delivering virulence factors, and causing lytic cell damage - cytolysis. Oxysterols are oxidized forms of cholesterol that regulate cellular cholesterol and alter immune resp...
Article
Full-text available
Many species of pathogenic bacteria secrete toxins that form pores in mammalian cell membranes. These membrane pores enable the delivery of virulence factors into cells, result in the leakage of molecules that bacteria can use as nutrients, and facilitate pathogen invasion. Inflammatory responses to bacteria are regulated by the side‐chain‐hydroxyc...
Article
Cobalt is one of the main components of metal hip prostheses and cobalt nanoparticles (CoNPs) produced from wear cause inflammation, bone lyses and cytotoxicity at high concentrations. Cobalt ions mimic hypoxia in the presence of normal oxygen levels, and activate hypoxic signalling by stabilising hypoxia inducible transcription factor 1α (HIF1α)....
Article
Full-text available
Certain species of pathogenic bacteria damage tissues by secreting cholesterol‐dependent cytolysins, which form pores in the plasma membranes of animal cells. However, reducing cholesterol protects cells against these cytolysins. As the first committed step of cholesterol biosynthesis is catalyzed by squalene synthase, we explored whether inhibitin...
Article
Full-text available
Pathogenic bacteria often damage tissues by secreting toxins that form pores in cell membranes, and the most common pore-forming toxins are cholesterol-dependent cytolysins. During bacterial infections, glutamine becomes a conditionally essential amino acid, and glutamine is an important nutrient for immune cells. However, the role of glutamine in...
Preprint
Full-text available
Pathogenic bacteria often damage tissues by secreting toxins that form pores in cell membranes, and the most common pore-forming toxins are cholesterol-dependent cytolysins. During bacterial infections, glutamine becomes a conditionally essential amino acid, and glutamine is an important nutrient for immune cells. However, the role of glutamine in...
Article
Full-text available
Metabolic pathways that regulate T-cell function show promise as therapeutic targets in diverse diseases. Here, we show that at rest cultured human effector memory and central memory CD4+ T-cells have elevated levels of glycolysis and oxidative phosphorylation (OXPHOS), in comparison to naïve T-cells. Despite having low resting metabolic rates, nai...
Chapter
Full-text available
The subfamily of ARAP proteins includes three members: ARAP1, ARAP2, and ARAP3, which can act as GAPs for both ARF and Rho family small GTPases. ARAP3 was originally identified as a PtdIns(3,4,5)P3 secondary messengerbinding protein in porcine leukocyte cytosol. It consists of a SAM domain, five PH domains, Rho-GAP domain and ARF-GAP domain, and a...
Article
Full-text available
Inflammation is a key feature of preterm and term labour. Pro-inflammatory mediators are produced by gestation-associated tissues in response to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Interleukin (IL)4, IL10 and IL13 are anti-inflammatory cytokines with potential as anti-inflammatory therapi...
Article
Full-text available
After parturition, uterine involution, regeneration of the endometrium, return of ovarian cyclic activity, and the control of pathogenic bacteria in the uterus is required before cows are likely to conceive again. However, pathogenic bacteria often cause uterine disease in modern dairy cattle, leading to decreased productivity and reduced fertility...
Article
Full-text available
Tissue homeostasis in the female genital tract is challenged by infection, damage, and even physiological events during reproductive cycles. We propose that the evolutionarily ancient system of innate immunity is sufficient to sense and respond to danger in the non-pregnant female genital tract. Innate immunity produces a rapidly inducible, non-spe...
Article
Full-text available
The intestinal epithelium functions to effectively restrict the causal uptake of luminal contents but has been demonstrated to transiently increase paracellular permeability properties to provide an additional entry route for dietary macromolecules. We have examined a method to emulate this endogenous mechanism as a means of enhancing the oral upta...
Article
Full-text available
During bone maintenance in vivo, estrogen signals through Estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived mesenchymal stromal cells (BMSC). This was assessed in relation to runt-related transcription fa...
Conference Paper
Full-text available
Introduction: ADP ribosylation factors ARF1 and ARF6 are monomeric GTP binding proteins that regulate desensitisation of G protein coupled receptor (GPCRs) like the luteinizing hormone receptor and oxytocin receptor. They are activated by a guanine nucleotide exchange factor called cytohesin 3 (CYTH3) to bind to GTP. The activated ARF6-CYTH3 comple...
Article
Full-text available
Adenosine diphosphate (ADP) is a critical regulator of platelet activation, mediating its actions through two G protein-coupled receptors, the P2Y(1) and P2Y(12) purinoceptors. Recently, we demonstrated that P2Y(1) and P2Y(12) purinoceptor activities are rapidly and reversibly modulated in human platelets, revealing that the underlying mechanism re...
Article
Full-text available
ARF6 (ADP-ribosylation factor 6) small GTP binding protein plays critical roles in actin cytoskeleton rearrangements and membrane trafficking, including internalisation of G protein coupled receptors (GPCR). ARF6 operates by cycling between GDP-bound (inactive) and GTP-bound (active) forms and is a potential regulator of GPCR-mediated uterine activ...
Chapter
Full-text available
The subfamily of ARAP (Arf GTPase activating proteins (GAPs) with Rho GAP, ankyrin repeat and pleckstrin homology domains) proteins includes 3 members: ARAP1, ARAP2 and ARAP3. ARAP proteins are a unique subfamily of Arf GAPs that can act as GAPs for both Arf and Rho family small GTPases. ARAP3 is a phosphatidylinositol(3,4,5)-triphosphate (PtdIns(3...
Article
Full-text available
AGAP1 (Arf GAP, GTPase, ankyrin repeat, PH) (also known as Centaurin-γ2) is an 89-kDa protein in both mouse and human cells that is expressed ubiquitously. It is a multi-domain protein comprised of an N-terminal GTP-binding protein-like (GLD) domain followed by split pleckstrin homology (PH), ADP-ribosylation factor GTPase activating protein (Arf G...
Article
Full-text available
The subfamily of ARAP (Arf GTPase activating proteins (GAPs) with Rho GAP, ankyrin repeat and pleckstrin homology domains) proteins includes 3 members: ARAP1, ARAP2 and ARAP3. ARAP proteins are a unique subfamily of Arf GAPs that can act as GAPs for both Arf and Rho family small GTPases. ARAP3 is a phosphatidylinositol(3,4,5)-triphosphate (PtdIns(3...
Article
Full-text available
To examine whether myosin light chain kinase (MLCK) inhibitors can reduce intestinal epithelial permeability increases in vitro. Isolated rat, mouse and human colonic tissue mucosae and Caco-2 monolayers were exposed to cytochalasin D (cD) and sodium caprate (C10), in the absence and presence of the MLCK inhibitors, ML-9 and D PIK. Transepithelial...
Article
A peptide inhibitor of myosin light chain kinase (MLCK), termed membrane permeant inhibitor of myosin light chain kinase (PIK), has previously been demonstrated to correct paracellular barrier defects associated with in vitro cell models of infectious and inflammatory intestinal disease. The current study describes a strategy to identify stable ana...

Projects

Projects (2)
Project
Understanding the cellular and molecular mechanisms of disease tolerance.