Anaphylactic shock depends on endothelial Gq/G11.
Anaphylactic shock is a severe allergic reaction involving multiple organs including the bronchial and cardiovascular system. Most anaphylactic mediators, like platelet-activating factor (PAF), histamine, and others, act through G protein-coupled receptors, which are linked to the heterotrimeric G proteins G(q)/G(11), G(12)/G(13), and G(i). The role of downstream signaling pathways activated by anaphylactic mediators in defined organs during anaphylactic reactions is largely unknown. Using genetic mouse models that allow for the conditional abrogation of G(q)/G(11)- and G(12)/G(13)-mediated signaling pathways by inducible Cre/loxP-mediated mutagenesis in endothelial cells (ECs), we show that G(q)/G(11)-mediated signaling in ECs is required for the opening of the endothelial barrier and the stimulation of nitric oxide formation by various inflammatory mediators as well as by local anaphylaxis. The systemic effects of anaphylactic mediators like histamine and PAF, but not of bacterial lipopolysaccharide (LPS), are blunted in mice with endothelial G alpha(q)/G alpha(11) deficiency. Mice with endothelium-specific G alpha(q)/G alpha(11) deficiency, but not with G alpha(12)/G alpha(13) deficiency, are protected against the fatal consequences of passive and active systemic anaphylaxis. This identifies endothelial G(q)/G(11)-mediated signaling as a critical mediator of fatal systemic anaphylaxis and, hence, as a potential new target to prevent or treat anaphylactic reactions.
Korhonen
Hanna
H
Institute of Pharmacology, University of Heidelberg, 69120 Heidelberg, Germany.
Fisslthaler
Beate
B
Moers
Alexandra
A
Wirth
Angela
A
Habermehl
Daniel
D
Wieland
Thomas
T
Schütz
Günther
G
Wettschureck
Nina
N
Fleming
Ingrid
I
Offermanns
Stefan
S
D000707:Anaphylaxis / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D001831:Body Temperature; D042783:Endothelial Cells / Q000378:metabolism*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010766:Phosphorylation; D015398:Signal Transduction / Q000502:physiology*; D013686:Telemetry; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D009569:Nitric Oxide; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020742:rhoA GTP-Binding Protein