Chondroitin sulphate : a candidate modulator of urothelial barrier formation and reconstitution following injury

Phillips, Rebecca

Abstract

Chondroitin sulphate (CS) has been described as contributing to the barrier function of the urothelium by forming a glycosaminoglycan (GAG) layer. It has been suggested that a defect in this layer contributes to chronic inflammatory uropathies, and this forms the basis of medical device therapies purported to replace the GAG layer. A review of the literature questioned the evidence supporting these claims.

This thesis set out to formulate a reproducible damage model using differentiated normal human urothelial (NHU) cells in vitro. Techniques employed to introduce damage included physical damage by scratch wounding, chemical damage using ketamine and hypoxia. Barrier formation and damage was assessed by measuring transepithelial electrical resistance (TEER) across differentiated cells.

The role of CS on barrier formation and restitution following injury was assessed by TEER studies. Assessment of the presence of CS on the luminal surface of the urothelium in situ was carried out by immunohistochemistry.

Damage by scratch wound resulted in a loss of TEER that repaired within 22 hours. Ketamine had a toxic effect on the cell cultures. Hypoxia produced a reproducible defect in barrier resistance. Cell cultures exposed to CS during differentiation formed a tighter maximum barrier compared to controls however, when CS was added to the medium following hypoxic injury there was no difference to barrier restitution. Immunohistochemical studies failed to demonstrate the presence of CS apart from in the stroma.

It is concluded that CS is not present on the urothelial surface and has no effect on barrier function in the diseased model. In a NHU culture model there is evidence that the maximum barrier is higher with CS. Evidence from this research supports clinical studies which have only demonstrated a placebo effect of CS. Future work should investigate mode of action of CS and other GAGs on NHU cells in culture.

Citation

Phillips, R. Chondroitin sulphate : a candidate modulator of urothelial barrier formation and reconstitution following injury. (Thesis). Hull York Medical School, the University of Hull and the University of York. https://hull-repository.worktribe.com/output/4220690

• Thesis Type: Thesis
• Deposit Date: Oct 2, 2018
• Publicly Available Date: Feb 23, 2023
• Keywords: Medicine
• Public URL: https://hull-repository.worktribe.com/output/4220690
• Additional Information: Hull York Medical School, University of Hull and University of York
• Award Date: Mar 1, 2018