The CXCR4/CXCR7/SDF-1 pathway contributes to the pathogenesis of Shiga toxin–associated hemolytic uremic syndrome in humans and mice
Tania N. Petruzziello-Pellegrini, … , James L. Brunton, Philip A. Marsden
Tania N. Petruzziello-Pellegrini, … , James L. Brunton, Philip A. Marsden
Published January 9, 2012
Citation Information: J Clin Invest. 2012;122(2):759-776. https://doi.org/10.1172/JCI57313.
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Research Article Nephrology

The CXCR4/CXCR7/SDF-1 pathway contributes to the pathogenesis of Shiga toxin–associated hemolytic uremic syndrome in humans and mice

Abstract

Hemolytic uremic syndrome (HUS) is a potentially life-threatening condition. It often occurs after gastrointestinal infection with E. coli O157:H7, which produces Shiga toxins (Stx) that cause hemolytic anemia, thrombocytopenia, and renal injury. Stx-mediated changes in endothelial phenotype have been linked to the pathogenesis of HUS. Here we report our studies investigating Stx-induced changes in gene expression and their contribution to the pathogenesis of HUS. Stx function by inactivating host ribosomes but can also alter gene expression at concentrations that minimally affect global protein synthesis. Gene expression profiling of human microvascular endothelium treated with Stx implicated a role for activation of CXCR4 and CXCR7 by their shared cognate chemokine ligand (stromal cell–derived factor-1 [SDF-1]) in Stx-mediated pathophysiology. The changes in gene expression required a catalytically active Stx A subunit and were mediated by enhanced transcription and mRNA stability. Stx also enhanced the association of CXCR4, CXCR7, and SDF1 mRNAs with ribosomes. In a mouse model of Stx-mediated pathology, we noted changes in plasma and tissue content of CXCR4, CXCR7, and SDF-1 after Stx exposure. Furthermore, inhibition of the CXCR4/SDF-1 interaction decreased endothelial activation and organ injury and improved animal survival. Finally, in children infected with E. coli O157:H7, plasma SDF-1 levels were elevated in individuals who progressed to HUS. Collectively, these data implicate the CXCR4/CXCR7/SDF-1 pathway in Stx-mediated pathogenesis and suggest novel therapeutic strategies for prevention and/or treatment of complications associated with E. coli O157:H7 infection.

Authors

Tania N. Petruzziello-Pellegrini, Darren A. Yuen, Andrea V. Page, Sajedabanu Patel, Anna M. Soltyk, Charles C. Matouk, Dennis K. Wong, Paul J. Turgeon, Jason E. Fish, J.J. David Ho, Brent M. Steer, Vahid Khajoee, Jayesh Tigdi, Warren L. Lee, David G. Motto, Andrew Advani, Richard E. Gilbert, S. Ananth Karumanchi, Lisa A. Robinson, Phillip I. Tarr, W. Conrad Liles, James L. Brunton, Philip A. Marsden

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Figure 5

Functional effects of Stx and the CXCR4/CXCR7/SDF-1 axis on endothelial permeability.

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Functional effects of Stx and the CXCR4/CXCR7/SDF-1 axis on endothelial ...
(A) Confluent endothelial monolayers were grown on transwell filters and treated with the indicated concentrations of Stx. Stx treatment causes increased dextran leak and decreased electrical resistance across the monolayer. The mean ± SEM of at least 3 independent experiments is shown. (B) Treatment of HMVECs with SDF-1 (50 ng/ml, 5 hours) induces dextran leak. The mean ± SEM of at least 3 independent experiments is shown. (C) Stx-induced HMVEC permeability is decreased by treatment of AMD3100/plerixafor. A representative experiment of 3 is shown (mean ± SD). *P < 0.05, **P < 0.001 vs. vehicle-treated cells.