title: Trypanosoma cruzi invades host cells through the activation of endothelin and bradykinin receptors: a converging pathway leading to chagasic vasculopathy.
abstract: OBJECTIVE
  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(A)R and ET(B)R) and bradykinin B(2) receptors (B(2)R).
  
  
  METHODS
  Intravital microscopy was used to determine whether ETR/B(2)R 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(2)R (HOE-140), ET(A)R (BQ-123) and ET(B)R (BQ-788), specific IgG antibodies to each GPCRs; cholesterol or calcium-depleting drugs. RNA interference (ET(A)R or ET(B)R genes) in parasite infectivity was investigated in HSMCs.
  
  
  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(A)R and ET(B)R 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(2)R, whereas RNA interference of ET(A)R and ET(B)R genes conversely reduced parasite internalization. ETRs/B(2)R-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
  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.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Daniele
authors.initials: D
authors.lastname: Andrade
authors.forename: Rafaela
authors.initials: R
authors.lastname: Serra
authors.forename: Erik
authors.initials: E
authors.lastname: Svensjö
authors.forename: Ana Paula C
authors.initials: AP
authors.lastname: Lima
authors.forename: Erivan S
authors.initials: ES
authors.lastname: Ramos
authors.forename: Fabio S
authors.initials: FS
authors.lastname: Fortes
authors.forename: Ana Carolina F
authors.initials: AC
authors.lastname: Morandini
authors.forename: Verônica
authors.initials: V
authors.lastname: Morandi
authors.forename: Maria de N
authors.initials: Mde N
authors.lastname: Soeiro
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Tanowitz
authors.forename: Julio
authors.initials: J
authors.lastname: Scharfstein
mesh_terms: D000818:Animals; D065094:Bradykinin B2 Receptor Antagonists; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D014355:Chagas Disease / Q000276:immunology / Q000378:metabolism* / Q000469:parasitology* / Q000473:pathology; D006224:Cricetinae; D004487:Edema / Q000378:metabolism / Q000473:pathology; D065130:Endothelin A Receptor Antagonists; D065131:Endothelin B Receptor Antagonists; D019332:Endothelin-1 / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000469:parasitology; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D007705:Kinins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000473:pathology; D043782:Receptor, Bradykinin B2 / Q000378:metabolism*; D044022:Receptor, Endothelin A / Q000378:metabolism*; D044023:Receptor, Endothelin B / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000276:immunology / Q000378:metabolism*
chemical_list: D065094:Bradykinin B2 Receptor Antagonists; D065130:Endothelin A Receptor Antagonists; D065131:Endothelin B Receptor Antagonists; D019332:Endothelin-1; D007705:Kinins; D043782:Receptor, Bradykinin B2; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D002118:Calcium