Wilcz-Villega E.M.,Trinity Center for Health science |
McClean S.,Institute of Technology Tallaght |
O'Sullivan M.A.,Trinity Center for Health science |
O'Sullivan M.A.,St Jamess Hospital
American Journal of Gastroenterology | Year: 2013
OBJECTIVES:The objective of this study was to investigate how mast cell tryptase may influence intestinal permeability and tight junction (TJ) proteins in vitro and explore translation to irritable bowel syndrome (IBS).METHODS:We investigate. The effect of: (1) tryptase on Caco-2 monolayers, (2) mast cell degranulation in a Caco-2/human mast cell-1 (HMC-1) co-culture model, (3) mast cell degranulation±tryptase inhibition with nafamostat mesilate (NM). Epithelial integrity was assessed by transepithelial resistance (TER), permeability to fluorescein isothiocyanate (FITC)-dextran and transmission electron microscopy (TEM). The expression of junctional proteins zonula occludens-1 (ZO-1), junctional adhesion molecule-A (JAM-A), claudin-1 (CLD-1), CLD-2, CLD-3, occludin and E-cadherin was determined by western blot analysis and immunofluorescence confocal microscopy. Based o. The in vitro results, we further assessed JAM-A expression in biopsy tissue (cecum) from 34 IBS patients, 12 controls, and 8 inflammatory controls using immunofluorescence confocal microscopy and explored associations between JAM-A and IBS symptoms.RESULTS: ptase disrupted epithelial integrity in Caco-2 monolayers as shown by a significant decrease in TER, an increase in permeability to FITC-dextran, and a decrease i. The expression of junctional proteins JAM-A, CLD-1, and ZO-1 within 24 h. Correspondingly, i. The Caco-2/HMC-1 co-culture model we showed a significant decrease in TER, an increase in permeability to FITC-dextran, an. The presence of open TJs (TEM) in response to mast cell degranulation within 24 h. In this co-culture model, mast cell degranulation significantly decreased JAM-A and CLD-1 protein expression at 24 h. Tryptase inhibition (NM) significantly reduce. The effect of mast cell degranulation o. The junctional protein JAM-A, TER, and FITC-dextran flux. In IBS, epithelial JAM-A protein expression was significantly reduced in IBS tissue compared with controls. Lower JAM-A expression was associated with more severe abdominal pain (r s =-0.69, P=0.018) and longer duration of symptoms (r s =-0.7, P=0.012) in IBS-alternating subtype.CONCLUSIONS:uced JAM-A expression in vitro appears to contribute t. The underlying mechanisms of altered epithelial integrity in response to tryptase released from degranulating mast cells. In IBS, JAM-A expression was significantly reduced i. The cecal epithelium and associated with abdominal pain severity. JAM-A may provide new insights int. The underlying mechanisms in IBS.
McClean S.,Institute of Technology Tallaght
Protein and Peptide Letters | Year: 2012
Gram negative bacteria have evolved many mechanisms of attaching to and invading host epithelial and immune cells. In particular, many outer membrane proteins (OMPs) are involved in this initial interaction between the pathogen and their host. This review focuses on a number of small pore-forming OMPs that are all composed of eightstranded β- barrel proteins and include members of the OmpA, OmpW and OmpX families of proteins. These proteins, together with the related OmpA-like peptidoglycan associated lipoproteins, are involved in interactions with host cells and are mediators of virulence. In many cases, these proteins interact with host immune cells and can be considered as pathogen associated molecular patterns (PAMPS) due to their ability to signal via Toll like receptor molecules and other pattern recognition receptors. The role of these proteins in pathogenesis is discussed here, together with the potential for these proteins to be used as immunoprophylactic agents to protect against infection. © 2012 Bentham Science Publishers.
Institute of Technology Tallaght | Date: 2013-11-14
A planar micro-reagent cartridge comprises a base layer having a fluid receiving cavity formed in a top surface thereof and a fluid disposed within the cavity, and intermediate layer and a top layer. The intermediate membrane layer is bonded to the base layer to seal the fluid receiving cavity and form a fluid reservoir pump chamber. The intermediate layer comprises a resiliently deformable flexible region that overlies the fluid receiving cavity and is configured to be depressed in response to application of pressure, and a rupturable valve region that overlies the fluid receiving cavity. A top layer is bonded to the intermediate layer, the top layer having an opening that exposes the deformable flexible region of the intermediate membrane layer and at least one channel that together with the intermediate membrane layer forms a fluid conduit having an inlet in fluid communication with the rupturable valve region of the intermediate layer. In use, depression of the deformable flexible region actuates the fluid reservoir pump chamber to rupture the rupturable valve region and pump fluid into the capillary.
Agency: Cordis | Branch: FP7 | Program: MC-IRSES | Phase: FP7-PEOPLE-2012-IRSES | Award Amount: 584.80K | Year: 2013
Oncologists still rely heavily on biological characterisation of tumours and a limited number of biomarkers which have demonstrated clinical utility. Routine cancer diagnostic tools may not be always sensitive enough and may only detect proteins at levels corresponding to an advanced stage of the disease. Recently, new genomic and proteomic molecular tools (molecular signatures) are being employed which include genetic and epigenetic signatures, changes in gene expression, protein profiles and post-translational modification of proteins. Such advanced diagnostic tools are not always readily adapted to clinical cancer screening due to their complexity, costs and the requirement for highly-qualified operators. Novel bioanalytical methodologies for detection of specific biomarkers/ biomolecules, based on nanostructured electronic sensors (rapid, sensitive devices capable of miniaturisation and deployment on site or in small clinics), fulfill the necessary requirements and have the potential to compliment time- and labour consuming clinical analysers used in medical laboratories currently. The primary objective of this proposal, therefore, is to gather together an international and interdisciplinary consortium of ten research teams from EU Member States, Third (including ENP) countries with EU agreements on S&T, in order to share and jointly exploit knowledge and expertise in the development of micro/nanosensors as tools in early cancer diagnosis. A key scientific target is the realisation of intelligent electronic devices which respond to biomolecules such as formaldehyde, amines, metal ions, saccharides, activities of amine oxidases, arginase and glutathione-S-transferase. This will entail design, development and characterisation of nano-scale transducers suitable for testing in clinical samples.
Wilcz-Villega E.,Trinity Center for Health science |
Mcclean S.,Institute of Technology Tallaght |
O'Sullivan M.,St Jamess Hospital
Neurogastroenterology and Motility | Year: 2014
Background: Increased intestinal permeability and altered expression of tight junction (TJ) proteins may be implicated in the pathogenesis of irritable bowel syndrome (IBS). This study aimed to investigate the expression of adherens junction (AJ) protein E-cadherin and TJ proteins zonula occludens (ZO)-1 and claudin (CLD)-1 and associations with IBS symptoms. Methods: Junctional proteins were immunostained in cecal biopsy tissue of Rome II IBS patients (n = 34) comprising both alternating (IBS-A) and diarrhea predominant (IBS-D) subtypes, and controls (n = 12). IBS symptom duration, abdominal pain severity and stool frequency were assessed for IBS patients. Protein expression was determined by immunofluorescence. Key Results: E-cadherin and ZO-1 protein expression was significantly lower (p = 0.03 and p = 0.016, respectively) in the cecal surface epithelium of the IBS group comprising both IBS-A and IBS-D subtypes. CLD-1 expression was not significantly altered compared with controls. On subtype analysis, ZO-1 expression was significantly reduced in both IBS-A and IBS-D compared with controls, whereas E-cadherin was reduced only in IBS-A. Lower E-cadherin expression was associated with longer symptoms duration specifically in IBS-A patients (rs = -0.76, p = 0.004). Reduced E-cadherin associated with abdominal pain severity in the overall IBS group (rs = -0.36, p = 0.041), but this association was unrelated to IBS subtype. Conclusions & Inferences: E-cadherin protein expression in the cecum was significantly lower in IBS-A compared with controls and associated with longstanding symptoms. E-cadherin was further associated with abdominal pain severity in the IBS group overall, but unrelated to IBS subtype. Altered E-cadherin expression may provide novel insights into mechanisms underlying intestinal barrier dysfunction in IBS. In this study, comprising IBS-A and IBS-D subtypes, E-cadherin and ZO-1 protein expression was significantly lower in the cecal surface epithelium compared with controls. Furthermore, reduced E-cadherin expressed in the IBS group was associated with more severe abdominal pain, and in IBS-A with longer duration of symptoms. Altered E-cadherin expression may provide novel insights into mechanisms underlying intestinal barrier dysfunction in IBS. © 2013 John Wiley & Sons Ltd.