Investigating a candidate biomarker of osteoarthritis: role in pathogenesis and efficacy to diagnose disease

Ghulam, Uzma 2023. Investigating a candidate biomarker of osteoarthritis: role in pathogenesis and efficacy to diagnose disease. PhD Thesis, Cardiff University. Item availability restricted.

	PDF - Accepted Post-Print Version Restricted to Repository staff only until 4 June 2025 due to copyright restrictions. Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (17MB)
	PDF (Cardiff University Electronic Thesis and Dissertation Form) - Supplemental Material Restricted to Repository staff only Download (104kB)

Abstract

The gradual degeneration of articular cartilage and bone remodelling in synovial joints is a complex process that characterizes osteoarthritis (OA). Inflammation plays a pivotal role in the early stages of the disease, contributing to the progressive loss of cartilage and bone. Clinicians rely on diagnostic tools to evaluate the severity of diseases and determine appropriate treatment plans. Despite efforts to develop a biomarker for early OA diagnosis, none have been validated yet. Nevertheless, it is widely recognized that serglycin plays a critical role in inflammation and associated tissue damage, as it regulates the secretion of inflammatory mediators like proteases, cytokines, and chemokines. Since inflammation is closely linked to the development of OA, it is possible that serglycin could be involved in its development and serve as an early diagnostic biomarker. Initial research into the possible involvement of serglycin in OA was conducted within the group by Andreas Heil (2015), and Caroline Kwas (2015) and demonstrated a significant increase in serglycin and sulfotransferase expression in a 3D cartilage model under OA-related inflammatory conditions. The monocyte THP-1 cell line expresses serglycin constitutively. Therefore, to source serglycin in this study, THP-1 cell expression of serglycin was investigated further to enable purification of the proteoglycan. The purified serglycin has been utilized to successfully develop a sandwich ELISA to test the relative quantity of serglycin expression in different cell types. In the context of OA as a disease of the whole joint, the biological behavior and serglycin expression of Y201 cells (a mesenchymal stem cell line), adipocytes (differentiated from Y201 cells), and cartilage tissue (differentiated from Y201 cells and chondroprogenitor cell lines) was studied under inflammatory conditions (IL-1β or Pam3Csk stimulation). Interestingly, it was found that Y201 cells constitutively express serglycin, and IL-1β stimulation induced significant upregulation in the synthesis and release of serglycin from the cell (detected by Western blot and ELISA of conditioned media). Whereas differentiated adipocytes did not show any alteration in the expression of serglycin following inflammatory stimulation. The vi cartilaginous tissue generated through chondrogenic differentiation of Y201 cells and immortalized chondroprogenitor cells showed upregulation in serglycin expression at the RNA level and its release in the conditioned media (WB) following IL-1β stimulation as compared to unstimulated control. However, using ELISA, no serglycin was detected following IL-1β stimulation in any of the cartilaginous tissue. Hence, this study has made a valuable contribution to the comprehension of the disparate regulation of IL-1β in relation to serglycin expression during the progression of OA and has further highlighted the potential of serglycin as a diagnostic biomarker for the early detection of OA.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Dentistry
Date of First Compliant Deposit:	4 June 2024
Last Modified:	04 Jun 2024 15:45
URI:	https://orca.cardiff.ac.uk/id/eprint/169468

Actions (repository staff only)

Edit Item