Investigations into avian cornea development and the influence of chondroitin sulphate proteoglycans on keratocyte phenotype

Bains, Kiranjit Kaur ORCID: https://orcid.org/0000-0001-6617-5768 2022. Investigations into avian cornea development and the influence of chondroitin sulphate proteoglycans on keratocyte phenotype. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

In the cornea, a population of stem/progenitor cells is known to reside in the putative limbal stem cell niche. The aim of research described in this thesis, using the avian eye as an experimental model, was to investigate a postulated role for chondroitin sulphate (CS) proteoglycans (PGs) in regulating the proliferation and differentiation potential of corneal stem/progenitor cells, as previously proposed for articular cartilage. To investigate the effects of CSPGs on progenitor cells, the thesis presents the first attempts to optimise a protocol for flow cytometric analysis of keratocytes cultured on different CS-based substrates to quantify changes in expression of putative stromal stem cell (PSSC) markers which found that the expression profile of PSSC markers changed towards a less-differentiated phenotype. A novel investigation was also undertaken to characterise the extracellular matrix distribution of CS, in addition to cellular and anatomical features of the avian stem cell niche using immunohistochemistry, scanning electron microscopy, transmission electron microscopy, and serial block-face scanning electron microscopy (SBF- SEM). The avian cornea labelled positively for CS sulphation-specific motifs with variations in regional distribution noted between motifs and developmental stages. Moreover, marked differences were discovered in the presumptive limbal stem cell niche of the avian eye from that in the human, whilst also confirming some shared characteristics. In SBF-SEM serial image 3D reconstructions, distinct undulating projections of epithelium and stroma similar in appearance to palisades of Vogt and limbal crypts were observed. Parts of the presumptive niche were shown to host cells morphologically similar to putative stem cells, have stromal-epithelial cell interactions, and be in close proximity to localised forms of CS. These findings suggest that CS may indeed have a role in regulating the potential of stem/progenitor cells within the presumptive stem cell niche in the avian cornea which could broaden the potential for future applications in tissue engineering strategies.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Optometry and Vision Sciences
Subjects:	R Medicine > RE Ophthalmology
Uncontrolled Keywords:	cornea, chondroitin sulphate, keratocytes, proteoglycans, stem cell niche
Date of First Compliant Deposit:	17 March 2022
Last Modified:	05 Oct 2023 01:49
URI:	https://orca.cardiff.ac.uk/id/eprint/148435

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