Blockade of NOX2 and STIM1 signaling limits lipopolysaccharide-induced vascular inflammation.
During sepsis, acute lung injury (ALI) results from activation of innate immune cells and endothelial cells by endotoxins, leading to systemic inflammation through proinflammatory cytokine overproduction, oxidative stress, and intracellular Ca2+ overload. Despite considerable investigation, the underlying molecular mechanism(s) leading to LPS-induced ALI remain elusive. To determine whether stromal interaction molecule 1-dependent (STIM1-dependent) signaling drives endothelial dysfunction in response to LPS, we investigated oxidative and STIM1 signaling of EC-specific Stim1-knockout mice. Here we report that LPS-mediated Ca2+ oscillations are ablated in ECs deficient in Nox2, Stim1, and type II inositol triphosphate receptor (Itpr2). LPS-induced nuclear factor of activated T cells (NFAT) nuclear accumulation was abrogated by either antioxidant supplementation or Ca2+ chelation. Moreover, ECs lacking either Nox2 or Stim1 failed to trigger store-operated Ca2+ entry (SOCe) and NFAT nuclear accumulation. LPS-induced vascular permeability changes were reduced in EC-specific Stim1-/- mice, despite elevation of systemic cytokine levels. Additionally, inhibition of STIM1 signaling prevented receptor-interacting protein 3-dependent (RIP3-dependent) EC death. Remarkably, BTP2, a small-molecule calcium release-activated calcium (CRAC) channel blocker administered after insult, halted LPS-induced vascular leakage and pulmonary edema. These results indicate that ROS-driven Ca2+ signaling promotes vascular barrier dysfunction and that the SOCe machinery may provide crucial therapeutic targets to limit sepsis-induced ALI.
Department of Biochemistry, Temple University, Philadelphia, Pennsylvania, USA.
Rajesh Kumar
RK
Gandhirajan
Shu
S
Meng
Harish C
HC
Chandramoorthy
Karthik
K
Mallilankaraman
Salvatore
S
Mancarella
Hui
H
Gao
Roshanak
R
Razmpour
Xiao-Feng
XF
Yang
Steven R
SR
Houser
Ju
J
Chen
Walter J
WJ
Koch
Hong
H
Wang
Jonathan
J
Soboloff
Donald L
DL
Gill
Muniswamy
M
Madesh
D055371:Acute Lung Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D015220:Calcium Channels; D020013:Calcium Signaling; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D005260:Female; D055785:Gene Knockdown Techniques; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000172:deficiency / Q000235:genetics; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D018805:Sepsis / Q000150:complications; D015398:Signal Transduction; D000071737:Stromal Interaction Molecule 1; D013830:Thiadiazoles / Q000494:pharmacology
C476308:4-methyl-4'-(3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl)-1,2,3-thiadiazole-5-carboxanilide; D000813:Anilides; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D050778:NFATC Transcription Factors; D017382:Reactive Oxygen Species; C100757:Stim1 protein, mouse; D000071737:Stromal Interaction Molecule 1; D013830:Thiadiazoles; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases