title: Cooperative signaling via transcription factors NF-κB and AP1/c-Fos mediates endothelial cell STIM1 expression and hyperpermeability in response to endotoxin.
abstract: Stromal interacting molecule 1 (STIM1) regulates store-operated Ca(2+) entry (SOCE). Here we show that STIM1 expression in endothelial cells (ECs) is increased during sepsis and, therefore, contributes to hyperpermeability. LPS induced STIM1 mRNA and protein expression in human and mouse lung ECs. The induced STIM1 expression was associated with augmented SOCE as well as a permeability increase in both in vitro and in vivo models. Because activation of both the NF-κB and p38 MAPK signaling pathways downstream of TLR4 amplifies vascular inflammation, we studied the influence of these two pathways on LPS-induced STIM1 expression. Inhibition of either NF-κB or p38 MAPK activation by pharmacological agents prevented LPS-induced STIM1 expression. Silencing of the NF-κB proteins (p65/RelA or p50/NF-κB1) or the p38 MAPK isoform p38α prevented LPS-induced STIM1 expression and increased SOCE in ECs. In support of these findings, we found NF-κB and AP1 binding sites in the 5'-regulatory region of human and mouse STIM1 genes. Further, we demonstrated that LPS induced time-dependent binding of the transcription factors NF-κB (p65/RelA) and AP1 (c-Fos/c-Jun) to the STIM1 promoter. Interestingly, silencing of c-Fos, but not c-Jun, markedly reduced LPS-induced STIM1 expression in ECs. We also observed that silencing of p38α prevented c-Fos expression in response to LPS in ECs, suggesting that p38α signaling mediates the expression of c-Fos. These results support the proposal that cooperative signaling of both NF-κB and AP1 (via p38α) amplifies STIM1 expression in ECs and, thereby, contributes to the lung vascular hyperpermeability response during sepsis.
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612.
authors.forename: Auditi
authors.initials: A
authors.lastname: DebRoy
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Vogel
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Soni
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612.
authors.forename: Premanand C
authors.initials: PC
authors.lastname: Sundivakkam
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612.
authors.forename: Asrar B
authors.initials: AB
authors.lastname: Malik
authors.affiliation: From the Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612 tiruc@uic.edu.
authors.forename: Chinnaswamy
authors.initials: C
authors.lastname: Tiruppathi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002199:Capillary Permeability; D002478:Cells, Cultured; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004731:Endotoxins / Q000494:pharmacology*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D000071737:Stromal Interaction Molecule 1; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D017931:DNA Primers; D004731:Endotoxins; D008565:Membrane Proteins; D016328:NF-kappa B; D009363:Neoplasm Proteins; D016760:Proto-Oncogene Proteins c-fos; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D018808:Transcription Factor AP-1; D048051:p38 Mitogen-Activated Protein Kinases
keywords: AP1 Transcription Factor (AP-1); Calcium; Endothelium; Gene Regulation; NF-κB Transcription Factor; Permeability; Sepsis; Thrombin; p38 MAPK