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Supervisors:
Wendy Heywood and Jenny Hallqvist
Project Description:
Background:
The lysosomal enzyme Glucocerebrosidase (GBA) catalyses one of the last steps of the glycosphingolipid degradation pathway. Defects of GBA are associated with the lysosomal storage disorder Gaucher disease and heterozygotes have a higher risk for developing Parkinson’s disease [1]. This is an important pathway in cellular lipid homeostasis and data from our laboratory shows that deficient activity of GBA disrupts not just lysosomal but also extra-lysosomal lipid metabolism. This ultimately appears to affect cellular energy metabolism. GBA is thought to have additional functions other than GSL degradation and can act as a transglucosidase removing glucose from glucosylceramide to cholesterol [2]. Unpublished data from our group has shown glucosylated cholesterol is increased in GBA heterozygote neuronal cells and in the brain tissue of Parkinson’s disease patients. This indicates cholesterol metabolism has a so far unknown role in the pathogenesis of GBA deficiency.
Aims/Objectives:
The goal of this project is to understand the effect of GBA dysfunction on the flux of lipids related to its pathway and its downstream effects on other lipid pathways that may cause disease.
Methods:
The project will involve using non-radioactive, stable isotope lipid (SIL) tracers and cutting-edge Omic technology to monitor the ‘flux’ of the GBA lipid pathway on neuronal cell models. Some of these SIL tracers are available commercially and some will be synthesised in house. The breakdown and recycling of components of the SIL tracers will be measured using untargeted lipid profiling and targeted mass spectrometry. Lipid data will be analysed and computational modelling will be used to create a ‘lipid flux model’ of glucosylceramide catabolism and anabolism in different biological contexts such as moderated GBA activity using inhibitors, cellular stress and dietary cholesterol levels. Understanding the lipid flux of GBA will provide a unique understanding of this complex pathway that can be a valuable resource for drug targeting. This project is a unique opportunity for a student to obtain experience in lipid biochemistry, state-of-the-art omic technology and bioinformatics.
Timeline:
Months
0-6 training in cell culture and mass spectrometry methods
6-9 creation of methods and targeted panels of glucosylceramide related lipids and phospholipids
6-12 Chemical synthesis of SIL glucosylceramide and feasibility checking on cell lines
12-18 Cell experiments on treated lines and cell lines from GBA mutants
18-22 Data analysis and lipid flux modelling
24-33 Functional confirmation and lipid pathway manipulation with drugs to determine their effect on the GBA lipid pathway flux
30-36 Thesis writing
Contact Information:
Dr Wendy Heywood