Dynamic insulin gene activity states in insulin producing cells
department or school: Medicine, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Chu, Chieh Min
issued: 2024-08-28T21:23:39Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Diabetes affects around 500 million people worldwide. Diabetes is marked by raised blood sugar levels owing to a relative or absolute lack of insulin, which is produced in pancreatic islet beta-cells. Pancreatic beta-cells are heterogeneous, with many studies reporting functional and morphological differences. However, it is unclear whether insulin gene activity is also heterogeneous in beta-cells and whether this heterogeneity is static or dynamic. We utilized a mouse model in which the endogenous Ins2 gene has been replaced with GFP (Ins2GFP), to study endogenous insulin gene activity. We found that beta-cells can be found in two states, Ins2(GFP)HIGH and Ins2(GFP)LOW. We also found that gene activity at the Ins2 loci was dynamic, and that cells could transition between the two beta-cell states over time. We profiled the two cell states at the transcriptome and proteome levels, and perturbed beta-cell functions using a small molecule screen to determine the mechanisms behind Ins2 dynamics and cell state transitions. We found that the Ins2(GFP)HIGH state was associated with increased beta-cell maturity factors and increased fragility, and cAMP pathways were the strongest effectors of Ins2 gene activity. We next investigated INS gene expression using an INS-EGFP stem cell-derived beta-cell line. Similar to the studies using beta-cells from Ins2GFP mice, we found that INS gene expression was bimodal and dynamic over time in stem cell-derived beta-like cells. We interrogated the two INS gene expression states with a combination of transcriptomics and proteomic analyses. We found that cells with high EGFP expression had increased mRNA expression and protein abundance in the endoplasmic reticulum (ER) and Golgi. To understand the relationship between INS gene dynamics and beta-cell survival, we also performed a high-throughput screen of prioritized ligands, curated from a combination of proteomic and transcriptomic data. We found that several factors, namely FGF5, FGF19…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/89073
note: DYNAMIC INSULIN GENE ACTIVITY STATES IN INSULIN PRODUCING CELLS by Chieh Min Chu B.Sc., National Central University, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Cell and Developmental Biology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2024 © Chieh Min Chu, 2024 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Dynamic insulin gene activity states in insulin producing cells submitted by Chieh Min Chu in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Cell and Developmental Biology Examining Committee: Dr. James D. Johnson, Professor, Department of Cellular and Physiological Sciences, UBC Supervisor Dr. Sheila J.S. Teves, Assistant Professor, Department of Biochemistry, UBC Supervisory Committee Member Dr. Wyeth Wasserman, Professor, Department of Medical Genetics, UBC University Examiner Dr. Louis Lefebevre, Associate Professor, Department of Medical Genetics, UBC University Examiner Additional Supervisory Committee Members: Dr. Francis C. Lynn, Associate Professor, Department of Surgery, UBC Supervisory Committee Member Dr. Eric Jan, Professor, Department of Biochemistry and Molecular Biology, UBC Supervisory Committee Member iii Abstract Diabetes affects around 500 million people worldwide. Diabetes is marked by raised blood sugar levels owing to a relative or absolute lack of insulin, which is produced in pancreatic islet beta-cells. Pancreatic beta-cells are heterogeneous, with many studies reporting functional and morphological differences. However, it is unclear whether insulin gene activity is also heterogeneous in beta-cells and whether this heterogeneity is static or dynamic. We utilized a mouse model in which the endogenous Ins2 gene has been replaced with GFP (Ins2GFP), to study endo…
has type: Thesis/Dissertation
date issued: 2024-11
is shown at: 10.14288/1.0445197
language: eng
degree discipline: Cell and Developmental Biology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Johnson, James D.
type: Text
identifier URI: http://hdl.handle.net/2429/89073