Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia
FRDA is the most common hereditary ataxia in the western world. The disorder is characterised by a pathological GAA trinucleotide repeat expansion in the FXN gene, resulting in a decrease in the expression of its encoded protein, frataxin. Symptoms commonly arise during adolescence, with patients ex...
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| Format: | Thesis |
| Language: | English |
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2021
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| _version_ | 1797108889637879808 |
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| author | Maheshwari, S |
| author2 | Vilema-Enríquez , G |
| author_facet | Vilema-Enríquez , G Maheshwari, S |
| author_sort | Maheshwari, S |
| collection | OXFORD |
| description | FRDA is the most common hereditary ataxia in the western world. The disorder is characterised by a pathological GAA trinucleotide repeat expansion in the FXN gene, resulting in a decrease in the expression of its encoded protein, frataxin. Symptoms commonly arise during adolescence, with patients exhibiting a clinical syndrome of progressive neurodegeneration, cardiomyopathy and endocrine dysfunction. FRDA remains without a cure, likely due to our incomplete understanding of disease pathology, coupled with limitations surrounding the in vitro models historically used for drug
discovery. Recently, the methyltransferases SUV4-20 have been identified for their role in facilitating the partial silencing of FXN, through an increase in repressive H4K20 di- and trimethylation marks. Inhibition of SUV4-20 by the tool compound A-196 has been show to rescue FXN expression, implicating SUV4-20 as an exciting therapeutic target for FRDA. Working in collaboration with medicinal chemists, we were provided with 22 structural derivatives of A-196, in order to determine their effectiveness to increase FXN expression. We found that several analogues were capable of increasing FXN expression in our FXNLuciferase reporter model. Progression of the most promising analogues to testing in FRDA patient fibroblast lines, demonstrated one compound capable of significantly increasing FXN mRNA expression. Additionally, by adapting 2 previously published differentiation protocols we aimed to establish an iPSC-derived sensory neuronal model of FRDA. Utilising 2 control and 2 FRDA iPSC lines, we analysed the gene expression profiles and performed immunocytochemistry staining of derived cells, confirming the successful generation of an iPSC-derived sensory neuronal model. Further work is required to fully establish this model and determine the subpopulations of PSNs derived. Thus, overall this project contributes to accelerating drug development for FRDA, firstly by advancing our understanding of the epigenetic mechanisms underpinning FXN repression, and secondly by working towards developing a phenotypically relevant cellular model of the disease. |
| first_indexed | 2024-03-07T07:32:49Z |
| format | Thesis |
| id | oxford-uuid:0cd4b8de-a586-4356-9b0a-6feb20ba41f5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:32:49Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | oxford-uuid:0cd4b8de-a586-4356-9b0a-6feb20ba41f52023-02-21T13:11:26ZPharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia Thesishttp://purl.org/coar/resource_type/c_bdccuuid:0cd4b8de-a586-4356-9b0a-6feb20ba41f5Stem cellsFriedreich's ataxiaDrug developmentEpigeneticsEnglishHyrax Deposit2021Maheshwari, SVilema-Enríquez , GWade-Martins, ROliver, PGiunti, PFRDA is the most common hereditary ataxia in the western world. The disorder is characterised by a pathological GAA trinucleotide repeat expansion in the FXN gene, resulting in a decrease in the expression of its encoded protein, frataxin. Symptoms commonly arise during adolescence, with patients exhibiting a clinical syndrome of progressive neurodegeneration, cardiomyopathy and endocrine dysfunction. FRDA remains without a cure, likely due to our incomplete understanding of disease pathology, coupled with limitations surrounding the in vitro models historically used for drug discovery. Recently, the methyltransferases SUV4-20 have been identified for their role in facilitating the partial silencing of FXN, through an increase in repressive H4K20 di- and trimethylation marks. Inhibition of SUV4-20 by the tool compound A-196 has been show to rescue FXN expression, implicating SUV4-20 as an exciting therapeutic target for FRDA. Working in collaboration with medicinal chemists, we were provided with 22 structural derivatives of A-196, in order to determine their effectiveness to increase FXN expression. We found that several analogues were capable of increasing FXN expression in our FXNLuciferase reporter model. Progression of the most promising analogues to testing in FRDA patient fibroblast lines, demonstrated one compound capable of significantly increasing FXN mRNA expression. Additionally, by adapting 2 previously published differentiation protocols we aimed to establish an iPSC-derived sensory neuronal model of FRDA. Utilising 2 control and 2 FRDA iPSC lines, we analysed the gene expression profiles and performed immunocytochemistry staining of derived cells, confirming the successful generation of an iPSC-derived sensory neuronal model. Further work is required to fully establish this model and determine the subpopulations of PSNs derived. Thus, overall this project contributes to accelerating drug development for FRDA, firstly by advancing our understanding of the epigenetic mechanisms underpinning FXN repression, and secondly by working towards developing a phenotypically relevant cellular model of the disease. |
| spellingShingle | Stem cells Friedreich's ataxia Drug development Epigenetics Maheshwari, S Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title | Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title_full | Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title_fullStr | Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title_full_unstemmed | Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title_short | Pharmacological inhibition of the methyltransferases SUV4-20 in cellular models of Friedreich’s ataxia |
| title_sort | pharmacological inhibition of the methyltransferases suv4 20 in cellular models of friedreich s ataxia |
| topic | Stem cells Friedreich's ataxia Drug development Epigenetics |
| work_keys_str_mv | AT maheshwaris pharmacologicalinhibitionofthemethyltransferasessuv420incellularmodelsoffriedreichsataxia |