Heat shock protein 90 inhibitors prevent lps-induced endothelial barrier dysfunction by disrupting Rhoa signaling

Atul D. Joshi, Christiana Dimitropoulou, Gagan Thangjam, Connie Snead, Sara Feldman, Nektarios Barabutis, David Fulton, Yali Hou, Sanjiv Kumar, Vijay Patel, Boris A Gorshkov, Alexander D. Verin, Stephen Matthew Black, John D. Catravas

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


Permeability of the endothelial monolayer is increased when exposed to the bacterial endotoxin LPS. Our previous studies have shown that heat shock protein (Hsp) 90 inhibitors protect and restore LPS-mediated hyperpermeability in bovine pulmonary arterial endothelial cells. In this study, we assessed the effect of Hsp90 inhibition against LPS-mediated hyperpermeability in cultured human lung microvascular endothelial cells (HLMVECs) and delineated the underlying molecular mechanisms. We demonstrate that Hsp90 inhibition is critical in the early phase, to prevent LPS-mediated hyperpermeability, and also in the later phase, to restore LPS-mediated hyperpermeability in HLMVECs. Because RhoA is a well known mediator of endothelial hyperpermeability, we investigated the effect of Hsp90 inhibition on LPS-mediated RhoA signaling. RhoA nitration and activity were increased by LPS in HLMVECs and suppressed when pretreated with the Hsp90 inhibitor, 17-allylamino-17 demethoxy-geldanamycin (17-AAG). In addition, inhibition of Rho kinase, a downstream effector of RhoA, protected HLMVECs from LPS-mediated hyperpermeability and abolished LPS-induced myosin light chain (MLC) phosphorylation, a target of Rho kinase. In agreement with these findings, 17-AAG or dominant-negative RhoA attenuated LPSinduced MLC phosphorylation. MLC phosphorylation induced by constitutively active RhoA was also suppressed by 17-AAG, suggesting a role for Hsp90 downstream of RhoA. Inhibition of Src family kinases also suppressed RhoA activity and MLC phosphorylation. Together, these data indicate that Hsp90 inhibition prevents and repairs LPS-induced lung endothelial barrier dysfunction by suppressing Src-mediated RhoA activity and signaling.

Original languageEnglish (US)
Pages (from-to)170-179
Number of pages10
JournalAmerican journal of respiratory cell and molecular biology
Issue number1
StatePublished - Jan 2014


  • Endothelial permeability
  • Heat shock protein 90
  • LPS
  • Rho kinase
  • RhoA

ASJC Scopus subject areas

  • Molecular Biology
  • Pulmonary and Respiratory Medicine
  • Clinical Biochemistry
  • Cell Biology


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