Saudi Cultural Missions Theses & Dissertations
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Item Restricted The Role of Probiotics in the Maintenance of the Gut Barrier(The University of Manchester, 2016) Ghouth, Nahlah; O'Neill, CatherineBackground and Aims Leaky gut barrier was identified as the pathogenesis of many Gastro Intestinal Tract diseases. Live probiotics were deemed helpful in reversing the leakiness by restoring the epithelial Tight Junction structures responsible of maintaining paracellular permeability. However, for some probiotics, there are safety concerns in taking live organism in conditions where the gut is inflamed. Here, killed Lactobacillus rhamnosus GG (LGG) and its cell free supernatant are being investigated to establish whether or not they can induce the same therapeutic effect as live organism in a Caco-2 model of gut barrier. Method Caco-2 cells were plated onto transwell membranes with a pore size of 0.4 μm. All three forms of LGG were added to cells and the Transepithelial Electrical Restistance- a marker of barrier function, was measured with time. The effects of an inflammatory cytokine, TNF-a were also tested by addition of the cytokine to cells treated with LGG. Result Overall, Caco-2 permeability was unchanged by LGG irrespective to the form used. Co- treatment of Caco-2 with LGG and TNF-α gave slightly lower resistance compared to their control. Conclusion These data suggest that LGG does not affect the permeability of Caco-2 cells.5 0Item Restricted The role of Proline-Rich Homeodomain protein PRH/HHEX in cholangiocarcinoma.(The University of Nottingham, 2024) Ghouth, Nahlah; Gaston, Kevin; Bates, DavidCholangiocarcinoma (CCA) is a malignancy of the bile ducts that arises from their lining epithelial cells. CCA has increasing incidence and mortality. Proline Rich Homeodomain / Haematopoietically Expressed Homeobox Protein (PRH/HHEX) is a transcription factor that acts as an oncoprotein in CCA. Here, using cumulative growth and EdU incorporation assays, I show that PRH expression in immortalised cholangiocytes (AKN1 cells) increased cell growth and proliferation. Additionally, I show using immunofluorescence imaging and Western blotting that PRH expression in AKN1 cells induces cellular phenotypes that resembles partial epithelial to mesenchymal transition (EMT), and that this morphological transformation is accompanied by an increase in cell migration and cell invasion. Recently, PRH expression has been reported to upregulate the expression of the mesenchymal marker protein Vimentin in CCA cells. To date most published research has focused on Vimentin expression in mesenchymal cells and its roles in the cytoplasm. Vimentin is known to participate in several biological processes such as cell proliferation, EMT, cell adhesion, cell migration, and cell invasion which have been reported to be upregulated in cancer cells with the consequence of increased tumour growth and disease progress. Knowledge on the role or roles of Vimentin in the nucleus is limited. However, nuclear Vimentin was reported to exhibit gene regulatory activity in Neuroblastoma cells. To expand knowledge on the importance of Vimentin in CCA, I used a combination of high and super-resolution imaging techniques to show that PRH may spatially exist near Vimentin in the nuclear subcellular regions of CCA cells. In addition, I used siRNA to deplete Vimentin in CCA cells and to reveal that Vimentin loss inhibits cell proliferation, induces an epithelial-like morphology, and reduces cell migration. Gene ontology (GO) and Gene Set Enrichment Analysis (GSEA) of RNAseq data generated using these cells revealed that Vimentin, in conjunction with PRH, regulates multiple signalling pathways in line with the phenotype of Vimentin-depleted cells. This project provides new insights into the importance of PRH and Vimentin in CCA. The novel PRH and Vimentin spatial organisation and the identified target genes co-regulated by PRH and Vimentin serve as new potential targets for future interventional studies.24 0