Session: Session 2

Quantitative proteomics analysis of in vitro human brain pericytes in normal condition and after treatment with pro-inflammatory cytokines

Brain pericytes (BPs) are the major inducers of the Blood-Brain Barrier phenotype carried by brain microvessel endothelial cells (ECs) and enable this phenotype to be maintained throughout life. However, in the context of neurodegenerative diseases, BPs are exposed to pro-inflammatory cytokines of cerebral origin such as Tumor Necrosis Factor-α (TNF-α), Interleukin-1ß (IL-1ß) and Interferon-γ. Given that cerebral damage can affect cerebrovascular cells, as demonstrated in Alzheimer's disease where progressive damage to BPs by perivascular accumulation of ß-amyloid (Aß) peptides leads to microvascular alterations and damage to the BBB, our study focuses on the consequences of pro-inflammatory cytokines on BPs. Using data obtained by mass spectrometry analysis and TMT-based quantification on BPs treated with 10 ng/mL TNF-α, IFN-γ or a combination of the two cytokines, we observed activation of the pathway leading to IL-1ß secretion in association with the NLRP3-CASP1 complex. The formation of this complex and the activity of CASP1 were correlated with co-IP and functionality tests. The amount of IL-1ß produced after treatment was quantified by ELISA. The response of BPs to IL-1ß was also quantified by TMT-based quantification. This study demonstrates the complexity of responses of BPs in a pro-inflammatory context, which could ultimately lead to damage to the BBB.