Decoding the molecular in vivo language of pericytes in stroke: New targets for stroke interventions

Pericytes are guardians of the brain’s microenvironment. Perturbations such as hypoxia shift their signalling which has multiple downstream effects.

Although their maladaptive response is increasingly linked to brain pathology, we lack an in depth understanding of their in vivo proteome to date.We aim to identify, validate and modulate pericyte signalling in ischemic stroke with the purpose to design novel approaches to intervene with stroke progression.

Using an engineered biotin ligase (TurboID), we label the cell-specific secretome in stroke models in vivo and in cocultures, and combine this with analysis of the protein cargo of pericyte-derived microvesicles in human stroke.

We identify the pericyte-specific proteome using mass spectrometry and multiplex assays and assess its temporal dynamic.To map the spatial distribution of secreted molecules in relation to multiple cell types, we use imaging mass cytometry in animal and human post mortem stroke sections.Finally, we select key targets based on pathophysiological relevance and verify their functional impact in loss of function studies in vitro using CRISPR/Cas9 technology, and in vivo using several transgenic mouse lines.As outcome, the program delivers a pericyte-specific protein atlas in stroke with temporal, spatial and functional characteristics.

Potentially druggable key targets are selected that can be used for development of novel treatments targeting pericyte pathology in order to control stroke progression.