Resolving the liver sinusoidal endothelial phenotype in health and disease

Papakyriacou, Pantelitsa (2024). Resolving the liver sinusoidal endothelial phenotype in health and disease. University of Birmingham. Ph.D.

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Abstract

The burden of liver disease is continuously increasing globally, and this emphasises the need for the development of therapeutics. In order for this to be achieved, potential cellular and molecular targets need to be identified. Liver sinusoidal endothelial cells (LSECs) play a key role in maintaining liver homeostasis and their dysfunction drives liver disease pathophysiology and this role needs to be further elucidated.
In order to identify phenotypic differences in LSECs in health and disease, a combination of analytical techniques such as immunohistochemistry and qPCR was applied on human tissue specimens. To confirm whether these changes are recapitulated in vitro, I isolated LSECs from human healthy and cirrhotic tissue specimens for the establishment of culture model of human LSECs. Validation of functional and phenotypic characteristics of LSECs in vitro was carried out using immunocytochemistry and qPCR. Furthermore, the development and optimisation of a super-resolution imaging protocol for the visualisation of LSEC fenestrations was performed.
Altered expression and downregulation of scavenger receptors in LSECs was identified in diseased human tissue specimens compared to healthy specimens and this confirmed capillarisation of sinusoidal endothelial cells in liver disease. Expression of scavenger receptors and key regulatory molecules was maintained in LSECs in vitro. The phenotypic changes in LSECs identified in liver tissue specimens were partially recapitulated in LSECs in vitro. The application of pharmaceutical molecules for the enhancement of nitric oxide (NO) signalling in LSECs revealed an altered genotype in healthy and cirrhotic LSECs. Finally, fenestrations were visualised on the LSEC membrane using the developed super-resolution imaging protocol and improvement in LSEC porosity following the application of sildenafil citrate.
Hence these findings emphasise the relevance of appropriate culture models and imaging approaches to study phenotypic changes in LSECs in relation to disease and highlight the therapeutic potential of sildenafil citrate in improving LSECs porosity.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):