Details

Autor(en) / Beteiligte

• Grab, Dennis J
• Garcia-Garcia, Jose C
• Nikolskaia, Olga V
• Kim, Yuri V
• Brown, Amanda
• Pardo, Carlos A
• Zhang, Yongqing
• Becker, Kevin G
• Wilson, Brenda A
• de A Lima, Ana Paula C
• Scharfstein, Julio
• Dumler, J Stephen
• Raper, Jayne

Titel

Protease activated receptor signaling is required for African trypanosome traversal of human brain microvascular endothelial cells

Ist Teil von

• PLoS neglected tropical diseases, 2009-07, Vol.3 (7), p.e479

Ort / Verlag

United States: Public Library of Science

Erscheinungsjahr

2009

Quelle

MEDLINE

Beschreibungen/Notizen

• Using human brain microvascular endothelial cells (HBMECs) as an in vitro model for how African trypanosomes cross the human blood-brain barrier (BBB) we recently reported that the parasites cross the BBB by generating calcium activation signals in HBMECs through the activity of parasite cysteine proteases, particularly cathepsin L (brucipain). In the current study, we examined the possible role of a class of protease stimulated HBMEC G protein coupled receptors (GPCRs) known as protease activated receptors (PARs) that might be implicated in calcium signaling by African trypanosomes. Using RNA interference (RNAi) we found that in vitro PAR-2 gene (F2RL1) expression in HBMEC monolayers could be reduced by over 95%. We also found that the ability of Trypanosoma brucei rhodesiense to cross F2RL1-silenced HBMEC monolayers was reduced (39%-49%) and that HBMECs silenced for F2RL1 maintained control levels of barrier function in the presence of the parasite. Consistent with the role of PAR-2, we found that HBMEC barrier function was also maintained after blockade of Galpha(q) with Pasteurella multocida toxin (PMT). PAR-2 signaling has been shown in other systems to have neuroinflammatory and neuroprotective roles and our data implicate a role for proteases (i.e. brucipain) and PAR-2 in African trypanosome/HBMEC interactions. Using gene-profiling methods to interrogate candidate HBMEC pathways specifically triggered by brucipain, several pathways that potentially link some pathophysiologic processes associated with CNS HAT were identified. Together, the data support a role, in part, for GPCRs as molecular targets for parasite proteases that lead to the activation of Galpha(q)-mediated calcium signaling. The consequence of these events is predicted to be increased permeability of the BBB to parasite transmigration and the initiation of neuroinflammation, events precursory to CNS disease.