Contribution of long non-coding RNA to the glucocorticoid response in myeloid cells

Mackie, Heather (2019) Contribution of long non-coding RNA to the glucocorticoid response in myeloid cells. PhD thesis, University of Glasgow.

Abstract

There is emerging evidence supporting a role for long non-coding RNAs (lncRNAs) in mediating many fundamental biological processes, from haematopoiesis to homeostasis. LncRNA are also known to be involved in the immune response in both health and disease pathogenesis. However, whether anti-inflammatory drugs such as glucocorticoids (GCs), interfere in such processes is less clear. As myeloid cells, including monocytes and macrophages, are key contributors to the propagation and resolution of the immune response, and important GC targets, this thesis aims to address whether GCs mediate part of their downstream effects via lncRNA in these cells.
Upon GC treatment, thousands of ncRNA transcripts were found to be significantly upregulated in THP1 cells. Using a combination of bioinformatic and experimental approaches, this thesis has shown that one novel lncRNA (RP11-184M15.1) is robustly and reliably upregulated by GC treatment in vitro. Furthermore, lncRNA RP11-184M15.1 is robustly upregulated by GCs in primary CD14+ monocytes from healthy individuals and monocytes from patients with Rheumatoid Arthritis (RA). This GC-dependent increase in lncRNA RP11-184M15.1 expression was prolonged upon co-stimulation with the pro-inflammatory factors TNF and LPS. Interestingly, this lncRNA was also found to be differentially expressed in monocyte-derived macrophages generated using M-CSF and GM-CSF, with approximately ten-fold greater expression in M-CSF derived macrophages. M-CSF derived macrophages are thought to have an anti-inflammatory phenotype, whereas GM-CSF derived macrophages are pro-inflammatory, supporting a potential role for this lncRNA in the resolution of inflammation. Molecular and cellular characterisation also demonstrated that the subcellular localisation of this lncRNA is altered upon GC treatment. In untreated cells, it is most abundantly associated with chromatin, whereas upon GC treatment it is more abundant in the cytoplasmic fraction. This points to potential involvement in regulatory mechanisms occurring at a post-transcriptional level. Preliminary studies into potential functions of RP11-184M15.1 were carried out in this thesis, however the results were inconclusive.
In summation, this work has identified a novel lncRNA that may contribute to the anti-inflammatory process governed by GCs in myeloid cells, however further studies are required to fully define the role of RP11-184M15.1 in the GC response both after in vitro GC treatment, and after in vivo GC administration.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Glucocorticoid, non-coding RNA, monocytes, macrophages, myeloid cells, inflammation.
• Subjects: Q Science > QR Microbiology; Q Science > QR Microbiology > QR180 Immunology
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Supervisor's Name: Goodyear, Prof. Carl and Maciewicz, Dr. Rose
• Date of Award: 2019
• Embargo Date: 26 February 2022
• Depositing User: Mrs Marie Cairney
• Unique ID: glathesis:2019-41048
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 26 Feb 2019 10:46
• Last Modified: 26 Feb 2021 08:01
• Thesis DOI: 10.5525/gla.thesis.41048
• URI: https://theses.gla.ac.uk/id/eprint/41048