Differential expression analysis of PMA and 1,25(OH)2D3-induced monocyte-to-macrophage differentiation in THP-1 cells
| dc.contributor.author | Perumal, Kelda Chloe | |
| dc.contributor.co-supervisor | Meyer, Vanessa | |
| dc.contributor.supervisor | Gentle, Nikki | |
| dc.date.accessioned | 2024-10-24T11:17:40Z | |
| dc.date.available | 2024-10-24T11:17:40Z | |
| dc.date.issued | 2023-09 | |
| dc.description | A dissertation submitted in fulfilment of the requirements for the degree Master of Science (Molecular and Cell Biology), to the Faculty of Science, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, 2023. | |
| dc.description.abstract | The process of monocyte-to-macrophage differentiation is studied in vitro through the use of promonocytic model cell lines, such as the THP-1 cell line, where commonly used differentiation inducing agents include phorbol-12-myristate-13-acetate (PMA) and the active metabolite of vitamin D3, (1,25(OH)2D3; VD3). While both induce differentiation, differences in their mechanisms of action, as well as how the end states of the differentiation process differ, are not well understood. Therefore, this study used computational approaches to compare the effects of PMA and VD3 on the differentiation of monocytes into macrophages, using the promonocytic THP-1 cell line. Through the use of RNA-sequencing, gene expression was quantified in differentiated and undifferentiated THP-1 cells, treated with both PMA and VD3. Differential gene expression analysis was performed to determine genes that were differentially expressed as a result of either treatment relative to the untreated cells. This was followed by over-representation analysis to determine the pathways and processes in which the differentially expressed genes (DEGs) were involved. PMA treatment (3 989 DEGs) resulted in more changes in expression relative to VD3 treatment, where only 384 genes were found to be differentially expressed in response to treatment with VD3. Only TFE3, KIT and TRIB1 were observed to be crucial to the process of differentiation, irrespective of treatment. Apart from this, the treatments were observed to largely involve different biological pathways, resulting in cells that were phenotypically distinct from each other at the transcriptional level. This included changes observed in the expression of genes encoding transcription factors known to be involved in the differentiation process, such as CEBPA, GATA2, IRF8 and PU.1, as well as those encoding surface markers representative of monocytes and macrophages, such as CD14, CD64 and CD11b. The expression patterns observed here indicate that, at least at the concentrations and time points included in this study, PMA and VD3 induce macrophage-like cells that are at different stages of differentiation and are not comparable to either each other or primary macrophages. Furthermore, key differences observed in the expression of genes encoding pathogen recognition receptors and cytokines suggest that which differentiation inducing agent is used may have important implications for these cells’ capacity to recognise pathogens and produce cytokines. The findings of this study therefore emphasise that it is crucial to carefully consider the choice of differentiation-inducing agent when using THP-1 cells as an experimental system for studying monocyte-to-macrophage differentiation. | |
| dc.description.sponsorship | Post Graduate Merit Award from the University of the Witwatersrand, Johannesburg. | |
| dc.description.sponsorship | National Research Foundation (NRF). | |
| dc.description.submitter | MM2024 | |
| dc.faculty | Faculty of Science | |
| dc.identifier | 0000-0002-6151-3796 | |
| dc.identifier.citation | Perumal, Kelda Chloe. (2023). Differential expression analysis of PMA and 1,25(OH)2D3-induced monocyte-to-macrophage differentiation in THP-1 cells. [Master's dissertation, University of the Witwatersrand, Johannesburg]. https://hdl.handle.net/10539/41949 | |
| dc.identifier.uri | https://hdl.handle.net/10539/41949 | |
| dc.language.iso | en | |
| dc.publisher | University of the Witwatersrand, Johannesburg | |
| dc.rights | ©2023 University of the Witwatersrand, Johannesburg. All rights reserved. The copyright in this work vests in the University of the Witwatersrand, Johannesburg. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of University of the Witwatersrand, Johannesburg. | |
| dc.rights.holder | University of the Witwatersrand, Johannesburg | |
| dc.school | School of Molecular and Cell Biology | |
| dc.subject | Monocyte | |
| dc.subject | Macrophage | |
| dc.subject | Differentiation | |
| dc.subject | PMA | |
| dc.subject | Vitamin D3 | |
| dc.subject | RNA-sequencing | |
| dc.subject | Gene expression | |
| dc.subject | UCTD | |
| dc.subject.other | SDG-3: Good health and well-being | |
| dc.title | Differential expression analysis of PMA and 1,25(OH)2D3-induced monocyte-to-macrophage differentiation in THP-1 cells | |
| dc.type | Dissertation |