Project Reference: TRG27-PDN-AF1

Project title: How does unconventional protein secretion contribute to ageing in the CNS?

Project outline

Proteins which lack signal sequences are conventionally retained within the cytosol. However, these proteins can be secreted from cells via unconventional protein secretion (UPS) and recent studies have shown that this is a route for signalling between cells in their normal healthy state. The rate of secretion and population of secreted proteins (the secretome) varies in healthy vs diseased conditions but little is known about how UPS-mediated signalling contributes to maintaining a healthy CNS and whether this changes during ageing. Extracellular vesicles (EVs) are one of the key routes by which UPS occurs. EVs form within multivesicular bodies and are secreted from the cell. They can be taken up by neighbouring cells and their protein cargoes have been shown to regulate transcription and alter intracellular signalling within recipient cells. Using transgenic zebrafish with fluorescently labelled EVs, we have developed methods to isolate EVs and perform proteomics analysis on their protein cargoes. This BBSRC DTP project will compare the differences between EV-secreted proteins from the CNS of ‘young’ and ‘aged’ adult zebrafish to evaluate how the secretome changes during ageing. We will compare these secretome signatures to those from existing EV-proteomics data from cultured astrocytic, neuronal and microglial cell lines to determine the likely cell type responsible for secreting different protein cargoes. Using transgenic zebrafish with neurons, astrocytes and microglia labelled with different fluorescent proteins, we will use a variety of methods including antibody staining and biochemical assays, as well as fluorescent cell sorting and confocal microscopy, to identify the most likely cell types from which different protein cargoes originate. In the latter part of the project, we will use both genetic tools and pharmacological inhibitors to determine whether and how particular protein cargoes contribute to ageing in the CNS.

Principal Supervisor

Dr Angeleen Fleming

Email address: af425@cam.ac.uk

Department / Partner Institute: Physiology, Development and Neuroscience (PDN)

Website: https://www.pdn.cam.ac.uk/directory/angeleen-fleming

BBSRC strategic theme

Bioscience for an integrated understanding of health