BACKGROUND AND PURPOSE Independent studies in experimental models of Trypanosoma cruzi appointed different roles for endothelin-1 (ET-1) and bradykinin (BK) in the immunopathogenesis of Chagas disease. Here, we addressed the hypothesis that pathogenic outcome is influenced by functional interplay between endothelin receptors (ET AR and ET BR) and bradykinin B 2 receptors (B 2R). EXPERIMENTAL APPROACH Intravital microscopy was used to determine whether ETR/B 2R drives the accumulation of rhodamine-labelled leucocytes in the hamster cheek pouch (HCP). Inflammatory oedema was measured in the infected BALB/c paw of mice. Parasite invasion was assessed in CHO over-expressing ETRs, mouse cardiomyocytes, endothelium (human umbilical vein endothelial cells) or smooth muscle cells (HSMCs), in the presence/absence of antagonists of B 2R (HOE-140), ET AR (BQ-123) and ET BR (BQ-788), specific IgG antibodies to each GPCRs; cholesterol or calcium-depleting drugs. RNA interference (ET AR or ET BR genes) in parasite infectivity was investigated in HSMCs. KEY RESULTS BQ-123, BQ-788 and HOE-140 reduced leucocyte accumulation in HCP topically exposed to trypomastigotes and blocked inflammatory oedema in infected mice. Acting synergistically, ET AR and ET BR antagonists reduced parasite invasion of HSMCs to the same extent as HOE-140. Exogenous ET-1 potentiated T. cruzi uptake by HSMCs via ETRs/B 2R, whereas RNA interference of ET AR and ET BR genes conversely reduced parasite internalization. ETRs/B 2R-driven infection in HSMCs was reduced in HSMC pretreated with methyl-β-cyclodextrin, a cholesterol-depleting drug, or in thapsigargin- or verapamil-treated target cells. CONCLUSIONS AND IMPLICATIONS Our findings suggest that plasma leakage, a neutrophil-driven inflammatory response evoked by trypomastigotes via the kinin/endothelin pathways, may offer a window of opportunity for enhanced parasite invasion of cardiovascular cells.
|Original language||English (US)|
|Number of pages||15|
|Journal||British Journal of Pharmacology|
|State||Published - Mar 2012|
- Chagas disease
- Trypanosoma cruzi
ASJC Scopus subject areas