Investigating the role of Viperin in beta-cell function and inflammation

<p><b>Background:</b></p> <p>In type 1 diabetes, insulin-producing pancreatic beta-cells are destroyed by an autoimmune response. There are various cellular mechanisms, genes and environmental factors that may influence the autoimmune destruction of beta-cells. Previous...

Szczegółowa specyfikacja

Opis bibliograficzny
1. autor: Tebeka, N
Kolejni autorzy: Christian, H
Format: Praca dyplomowa
Język:English
Wydane: 2020
Hasła przedmiotowe:
_version_ 1826316676287692800
author Tebeka, N
author2 Christian, H
author_facet Christian, H
Tebeka, N
author_sort Tebeka, N
collection OXFORD
description <p><b>Background:</b></p> <p>In type 1 diabetes, insulin-producing pancreatic beta-cells are destroyed by an autoimmune response. There are various cellular mechanisms, genes and environmental factors that may influence the autoimmune destruction of beta-cells. Previous studies have shown high induction of Viperin (a viral-response protein of the innate immune system) in isolated human islets exposed to inflammatory cytokines and viruses. Viperin has also been shown to be present in the blood cells of pre-type 1 diabetic subjects. Based on this knowledge, we hypothesised on a possible role of Viperin in beta-cell apoptosis and dysfunction in the development and progression of type 1 diabetes. </p> <p><b>Methods:</b></p> This research aimed to investigate the role of Viperin in immune-mediated beta-cell apoptosis by using a combination of both in vitro and ex vivo models of beta-cell inflammation. In the INS1-rat beta-cell line, induction of Viperin mRNA expression levels was assessed, and apoptosis was determined after establishing siRNA knock-down of Viperin. Beta-cell apoptosis was also studied in isolated mouse islets of Viperin knock-out mice. RT-qPCR and mRNA sequencing were applied to investigate the influence of Viperin on mechanisms controlling beta-cell function and survival</p> <p><b>Results:</b></p> <p>The research findings show that in the INS1 beta-cell line and isolated mouse pancreatic islets, Viperin mRNA expression is highly induced within a few hours of exposure to inflammatory cytokines, and expression levels start to decrease over time. Viperin expression was also induced in mouse islets after systemic infection with a chimpanzee adenovirus. Interestingly, apoptosis starts to peak when Viperin levels are decreasing, suggesting that the two events may be linked. In the absence of Viperin, cytokine-induced beta-cell apoptosis is increased, implying that Viperin expression plays a protective role in beta-cells. To investigate this further, RT-qPCR was used to quantify downstream markers of cytokine signalling in the presence and absence of Viperin and results showed that Viperin influenced the expression pattern of these markers under normal and cytokine-stimulated conditions. </p> <p>As part of these studies, we opted to run total mRNA sequencing to take an unbiased approach to identify both individual genes, along with gene networks and pathways, that are influenced by viperin. These results indicated that Viperin seems to affect a wide array of genes involved in various cellular pathways such as cell development, immune response and homeostatic regulation. </p> <p><b>Conclusion:</b></p> <p>Viperin expression plays a protective role against cytokine-mediated beta-cell apoptosis. Viperin also influences the expression pattern of numerous genes and key regulatory markers that mediates various cellular functions in beta-cells. </p>
first_indexed 2024-03-06T22:11:05Z
format Thesis
id oxford-uuid:51d523f2-d17f-4336-817c-28c0f1a5733f
institution University of Oxford
language English
last_indexed 2024-12-09T03:49:13Z
publishDate 2020
record_format dspace
spelling oxford-uuid:51d523f2-d17f-4336-817c-28c0f1a5733f2024-12-08T12:26:57ZInvestigating the role of Viperin in beta-cell function and inflammationThesishttp://purl.org/coar/resource_type/c_db06uuid:51d523f2-d17f-4336-817c-28c0f1a5733fMetabolismMolecular biologyImmunologyPhysiologyEnglishHyrax Deposit2020Tebeka, NChristian, HCantley, J<p><b>Background:</b></p> <p>In type 1 diabetes, insulin-producing pancreatic beta-cells are destroyed by an autoimmune response. There are various cellular mechanisms, genes and environmental factors that may influence the autoimmune destruction of beta-cells. Previous studies have shown high induction of Viperin (a viral-response protein of the innate immune system) in isolated human islets exposed to inflammatory cytokines and viruses. Viperin has also been shown to be present in the blood cells of pre-type 1 diabetic subjects. Based on this knowledge, we hypothesised on a possible role of Viperin in beta-cell apoptosis and dysfunction in the development and progression of type 1 diabetes. </p> <p><b>Methods:</b></p> This research aimed to investigate the role of Viperin in immune-mediated beta-cell apoptosis by using a combination of both in vitro and ex vivo models of beta-cell inflammation. In the INS1-rat beta-cell line, induction of Viperin mRNA expression levels was assessed, and apoptosis was determined after establishing siRNA knock-down of Viperin. Beta-cell apoptosis was also studied in isolated mouse islets of Viperin knock-out mice. RT-qPCR and mRNA sequencing were applied to investigate the influence of Viperin on mechanisms controlling beta-cell function and survival</p> <p><b>Results:</b></p> <p>The research findings show that in the INS1 beta-cell line and isolated mouse pancreatic islets, Viperin mRNA expression is highly induced within a few hours of exposure to inflammatory cytokines, and expression levels start to decrease over time. Viperin expression was also induced in mouse islets after systemic infection with a chimpanzee adenovirus. Interestingly, apoptosis starts to peak when Viperin levels are decreasing, suggesting that the two events may be linked. In the absence of Viperin, cytokine-induced beta-cell apoptosis is increased, implying that Viperin expression plays a protective role in beta-cells. To investigate this further, RT-qPCR was used to quantify downstream markers of cytokine signalling in the presence and absence of Viperin and results showed that Viperin influenced the expression pattern of these markers under normal and cytokine-stimulated conditions. </p> <p>As part of these studies, we opted to run total mRNA sequencing to take an unbiased approach to identify both individual genes, along with gene networks and pathways, that are influenced by viperin. These results indicated that Viperin seems to affect a wide array of genes involved in various cellular pathways such as cell development, immune response and homeostatic regulation. </p> <p><b>Conclusion:</b></p> <p>Viperin expression plays a protective role against cytokine-mediated beta-cell apoptosis. Viperin also influences the expression pattern of numerous genes and key regulatory markers that mediates various cellular functions in beta-cells. </p>
spellingShingle Metabolism
Molecular biology
Immunology
Physiology
Tebeka, N
Investigating the role of Viperin in beta-cell function and inflammation
title Investigating the role of Viperin in beta-cell function and inflammation
title_full Investigating the role of Viperin in beta-cell function and inflammation
title_fullStr Investigating the role of Viperin in beta-cell function and inflammation
title_full_unstemmed Investigating the role of Viperin in beta-cell function and inflammation
title_short Investigating the role of Viperin in beta-cell function and inflammation
title_sort investigating the role of viperin in beta cell function and inflammation
topic Metabolism
Molecular biology
Immunology
Physiology
work_keys_str_mv AT tebekan investigatingtheroleofviperininbetacellfunctionandinflammation