DEVELOPING A CLINCALLY RELEVANT ISOGENIC CELL LINE OF HUNTINGTON'S DISEASE

Autor: Savic, Natasha
Jazyk: angličtina
Rok vydání: 2022
Druh dokumentu: Diplomová práce
Popis: Huntington’s Disease (HD) is a neurodegenerative disease caused by a CAG expansion in exon 1 of the HTT gene. The age of symptom onset is inversely correlated with the length of the CAG tract. CAA interruptions in the CAG tract have a protective effect, delaying the onset of symptoms despite still coding for a glutamine residue. Evidence suggests that genes outside of the CAG expansion also contribute to differences in age of symptom onset. To improve our knowledge of disease, a clinically relevant model system is necessary. Here, we identify that many model systems use overexpressed protein that fails to adhere to the stoichiometry of an endogenous system. Many systems also use CAG expansions beyond what would be seen in a clinical case of HD or do not appropriately account for the influence of other genes. TruHD fibroblast cells immortalized with human telomerase reverse transcriptase are derived from patient samples and have a stable genome. Here, we discuss attempts to develop isogenic cell lines by editing TruHD cells to have different CAG repeats. While we were unsuccessful in isolating clones carrying the desired edit, future researchers can use this work as a guide to navigate the successful creation of isogenic cells. We can compare phenotypes between pre and post edited cells to see how they change with a new CAG length in an otherwise stable genetic background. We also discuss the successful editing of TruHD cells with a CAG to CAA base edit to introduce a CAA interruption in diseased cells. We discuss how to propagate these cells for future research to compare pre and post edited cells to better understand the protective action of CAA interruptions.
Thesis
Bachelor of Science (BSc)
Huntington’s Disease is a neurodegenerative disease caused by excessive CAG repeats in the HTT gene. Without a way of delaying or stopping symptoms, we need model systems to understand why some individuals develop disease later than others. We know that people develop symptoms earlier in life when they have more CAG repeats, but we don’t fully understand the contribution of their other genes. We explore this by attempting to edit the DNA of a clinically relevant cell line to change the CAG repeats. Once we establish this system, we can compare the cells before and after editing to see exactly what changes are caused by the CAG repeat length. While we were not able to develop the cell line, this work should be used by future researchers as a troubleshooting guide as they develop a representative model system.
Databáze: Networked Digital Library of Theses & Dissertations