Activation of the Anaphase Promoting Complex as a Possible Treatment Strategy for Hutchinson Gilford Progeria Syndrome
| dc.contributor.advisor | Eskiw, Christopher | |
| dc.contributor.advisor | Harkness , Troy | |
| dc.contributor.committeeMember | Tanaka, Takuji OLINA | |
| dc.contributor.committeeMember | Conn, Kristen | |
| dc.contributor.committeeMember | Ai, Yongfeng | |
| dc.creator | Martinez Molina, Valeria CAROLINA | |
| dc.date.accessioned | 2023-05-18T15:09:35Z | |
| dc.date.available | 2023-05-18T15:09:35Z | |
| dc.date.copyright | 2023 | |
| dc.date.created | 2023-04 | |
| dc.date.issued | 2023-05-18 | |
| dc.date.submitted | April 2023 | |
| dc.date.updated | 2023-05-18T15:09:35Z | |
| dc.description.abstract | Numerous factors promote cellular aging, including the accumulation of protein within the nuclear lamina, leading to disrupted gene expression. An extreme example of this is found in children suffering from the premature aging disease, Hutchinson-Gilford Progeria Syndrome (HGPS). HGPS is a rare disease that affects children, causing premature aging and death around the age of 14. It is caused by a mutation in the LMNA gene, leading to the production and accumulation of the cytotoxic protein progerin. Progerin has downstream impacts on various cellular functions, such as nuclear morphology, heterochromatin organization, mitosis, DNA replication and repair, and gene transcription. Unfortunately, there is currently no cure for HGPS, and existing treatments still require further development to improve the quality of life for affected children. This research proposes a novel avenue of treatment that focuses on reducing progerin levels within cells by examining the potential of the Anaphase Promoting Complex (APC). The APC is a conserved multiprotein complex that promotes cell cycle progression by targeting proteins such as cyclins for ubiquitin and proteasome-dependent destruction. Moreover, the APC is crucial for mounting cellular stress responses and promoting longevity. Based on the evidence indicating that HGPS is characterized by genomic and proteomic instability, impaired metabolic signaling, mitochondrial dysfunction, and low proteasomal activity, which are cellular functions where the APC plays an important role, we hypothesized that an elevated APC activity would impact progerin levels. Using HGPS primary fibroblasts grown in tissue culture, we observed decreased progerin levels in cells treated with Mad2 inhibitor (M2I-1, an APC activator) compared to cells treated with DMSO (vehicle control). We observed that APC activation via M2I-1 induced morphological changes resulting in a higher proportion of cells resembling non-diseased cells. Likewise, APC activation increased the number of doublings of HGPS fibroblasts, which could be an indicator of cellular repair. APC-progerin interactome, assessed by proximity ligation assays (PLA) and co-immunoprecipitation (Co-IP), showed an interaction between APC subunits and progerin. Additionally, we observed that the proteasome inhibitor MG132 decreased progerin levels in HGPS fibroblasts; when MG132 was combined with M2I-1, progerin levels decreased even further. We concluded that autophagy partly mediates progerin removal after the APC is activated. To further explore this hypothesis, we treated HGPS fibroblasts with chloroquine alone or in combination with M2I-1, MG132, or MG132 and M2I-1. Chloroquine, an autophagy inhibitor, partially inhibited the effect of M2I-1, increasing progerin levels and colocalization with ubiquitin. These results are remarkable since to remove proteins in HGPS the APC would be asociated with autophagy. This research has the potential to benefit children suffering from this devastating disease and the increasing senior population, as aging is a major risk factor for cardiovascular diseases, in particular. Therefore, studying the pathways that link progeria with the normal aging process offers insight into developing potential therapeutic strategies for common diseases associated with aging. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | https://hdl.handle.net/10388/14688 | |
| dc.language.iso | en | |
| dc.subject | hutchinson gilford, progeria syndrome, aging, anaphase promoting complex, proteostasis, nutrigenomics, autophagy, proteasome,progerin | |
| dc.title | Activation of the Anaphase Promoting Complex as a Possible Treatment Strategy for Hutchinson Gilford Progeria Syndrome | |
| dc.type | Thesis | |
| dc.type.material | text | |
| thesis.degree.department | Food and Bioproduct Sciences | |
| thesis.degree.discipline | Food Science | |
| thesis.degree.grantor | University of Saskatchewan | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science (M.Sc.) |