Role of liver sinusoidal endothelial cells in non alcoholic fatty liver disease progression
Non-alcoholic fatty liver disease (NAFLD) is one of the major clinical challenges of the 21st century. For decades research focused on hepatocytes, but failed to unravel the mechanisms behind disease progression, while largely overlooking the role of the endothelial cell of the liver, the LSEC. LSECs, which form the walls of the hepatic sinusoids, contain small pores, or fenestrations, which facilitate the transfer of substrates between blood and hepatocytes. A ubiquitous clinical observation in the progression of NAFLD is the loss of fenestrations, which importantly precedes the onset of fibrosis, collagen “scar” tissue that is cleared primarily by LSECs. The mechanisms responsible for LSEC defenestration in NAFLD progression have yet to be described. We aim to study the changes in LSEC morphology and function and correlate the findings with the progression and subsequent stages of the NAFLD. Targeting LSECs has high therapeutic potential for liver diseases. Understanding the mechanisms underlying changes in LSEC morphology and function in relation to the initiation and progression of NAFLD will generate important new knowledge in the field and provide new strategies for diagnosis and treatment of liver diseases, a potential for immense benefit to society.
The project will use animal and human samples. Animals from very early stages of the disease will be used for the study of the initiation and progression of the disease, while human clinical samples from various stages of the disease will be used to investigate the corresponding findings from the animal studies. Male Sprague-Dawley rats will be subjected to a short feeding regime with high fructose diet (HFr for 5 weeks) or high fat diet (HF for 2 weeks), a well established diet for induction of fatty liver/NAFLD, after which their livers will be harvested for various histological and microscopical examinations, and for the isolation of primary cultures of LSECs. There are no expected clinical symptoms of high fructose and high fat diets for the duration of the feeding regime in this study. Currently, non-animal techniques or alternative models to the primary, freshly isolated LSECs, do not exist that would help us to investigate the role of these cells in the initiation and progression of NAFLD. We plan to use up to 264 rats, number which we come up to by practicing the 3Rs - thoroughly planning the experiments to reduce the number of animals, and performing extensive literature searches to avoid repetition of experiments.
The project will use animal and human samples. Animals from very early stages of the disease will be used for the study of the initiation and progression of the disease, while human clinical samples from various stages of the disease will be used to investigate the corresponding findings from the animal studies. Male Sprague-Dawley rats will be subjected to a short feeding regime with high fructose diet (HFr for 5 weeks) or high fat diet (HF for 2 weeks), a well established diet for induction of fatty liver/NAFLD, after which their livers will be harvested for various histological and microscopical examinations, and for the isolation of primary cultures of LSECs. There are no expected clinical symptoms of high fructose and high fat diets for the duration of the feeding regime in this study. Currently, non-animal techniques or alternative models to the primary, freshly isolated LSECs, do not exist that would help us to investigate the role of these cells in the initiation and progression of NAFLD. We plan to use up to 264 rats, number which we come up to by practicing the 3Rs - thoroughly planning the experiments to reduce the number of animals, and performing extensive literature searches to avoid repetition of experiments.