Endothelial Protease Activated Receptor 1 (PAR1) Signalling Is Required for Lymphocyte Transmigration across Brain Microvascular Endothelial Cells.
Silvia DragoniAnna PapageorgiouCaroline AraizJohn GreenwoodPatric TurowskiPublished in: Cells (2020)
Lymphocyte transendothelial migration (TEM) relies on ICAM-1 engagement on the luminal surface of the endothelial cells (ECs). In blood-brain barrier (BBB) ECs, ICAM-1 triggers TEM signalling, including through JNK MAP kinase and AMP-activated protein kinase (AMPK), which lead to the phosphorylation and internalisation of the adherens junction protein VE-cadherin. In addition to ICAM-1, G protein-coupled receptors (GPCRs) are also required for lymphocytes TEM across BBB ECs. Here, we investigated the role of protease activated GPCRs (PARs) and found a specific role for PAR1 in support of lymphocyte TEM across BBB ECs in vitro. PAR1 requirement for TEM was confirmed using protease inhibitors, specific small molecule and peptide antagonists, function blocking antibodies and siRNA-mediated knockdown. In BBB ECs, PAR1 stimulation led to activation of signalling pathways essential to TEM; notably involving JNK and endothelial nitric oxide synthase (eNOS), with the latter downstream of AMPK. In turn, nitric oxide production through eNOS was essential for TEM by modulating VE-cadherin on Y731. Collectively, our data showed that non-canonical PAR1 activation by a lymphocyte-released serine protease is required for lymphocyte TEM across the BBB in vitro, and that this feeds into previously established ICAM-1-mediated endothelial TEM signalling pathways.
Keyphrases
- blood brain barrier
- endothelial cells
- protein kinase
- nitric oxide synthase
- nitric oxide
- peripheral blood
- small molecule
- cerebral ischemia
- signaling pathway
- cell death
- social media
- oxidative stress
- skeletal muscle
- quantum dots
- mass spectrometry
- cancer therapy
- functional connectivity
- induced apoptosis
- big data
- amino acid
- single molecule
- high resolution
- electronic health record
- data analysis
- tyrosine kinase
- sensitive detection