- Title
- An investigation of the role of mitochondrial STAT3 and modulation of Reactive Oxygen Species in adipocyte differentiation
- Creator
- Kramer, Adam Hildyard
- ThesisAdvisor
- Prinsloo, Earl
- ThesisAdvisor
- Hoppe, Heinrich
- Date
- 2014
- Type
- text
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10962/54632
- Identifier
- vital:26595
- Description
- Stem cells have the ability to differentiate into a myriad of different cell types. The understanding of the differentiation process is of paramount importance if we are to use these cells in the lab as well as in therapeutics. Here, the levels and localization of the signal transducer and activator of transcription 3 (STAT3), with particular attention focused on the mitochondrial serine 727 phosphorylated form of STAT3 (pSTAT3S727) during differentiation, was investigated. Using the murine preadipocyte progenitor cell line 3T3-L1, as well as adipose derived human mesenchymal stem cells (HMSC-ad) as differentiation models, the relative levels of Reactive Oxygen Species (ROS) and the levels and localization of STAT3 were investigated during the differentiation process. ROS is known to play an important signalling role during differentiation and is well reported during the events of adipogenesis. ROS are generated as a by-product in the Electron Transport Chain (ETC), and it has recently been reported that pSTAT3S727 plays an important role at complex I of the ETC. Various techniques including fluorescence confocal microscopy, flow cytometry and Western blots were utilized to investigate the non-canonical role STAT3 plays during adipogenesis. Mitochondrial isolations were performed to investigate the levels of STAT3 in the mitochondria during differentiation. Further to this, an impedance based real time differentiation assay was developed using the xCELLigence Real Time Cell Analyser to monitor differentiation and the affects various compounds, including a STAT3 inhibitor, have on differentiation. Results indicate that upon induction of differentiation, levels of mitochondrial pSTAT3S727 dramatically decrease and leave the mitochondria. This corresponds to increasing levels of ROS. The canonical active form of STAT3 following phosphorylation on tyrosine 705 (pSTAT3Y705) was found to decrease and lose its nuclear localization. These initial results indicate that STAT3 plays an important non-canonical role in the mitochondria during differentiation.
- Format
- 155 leaves, pdf
- Publisher
- Rhodes University, Faculty of Science, Biochemistry, Microbiology and Biotechnology
- Language
- English
- Rights
- Kramer, Adam Hildyard
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Collections
RU Department of Biochemistry, Microbiology and Biotechnology (end of 2014)
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Microsoft Word - MSc Thesis Final, for library.docx | 21 MB | Adobe Acrobat PDF | View Details Download |