Blood Journal
Leading the way in experimental and clinical research in hematology

CD40: an upstream master switch for endothelial cell activation uncovered by RNAi-coupled transcriptional profiling

  1. Raquel Pluvinet1,
  2. Rut Olivar1,
  3. Jerzy Krupinski2,
  4. Inmaculada Herrero-Fresneda3,
  5. Anna Luque2,
  6. Joan Torras3,
  7. Josep M. Cruzado3,
  8. Josep M. Grinyó3,
  9. Lauro Sumoy4, and
  10. Josep M. Aran1
  1. 1Medical and Molecular Genetics Center, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona;
  2. 2Department of Neurology, Stroke Unit and
  3. 3Laboratory of Nephrology, Medicine Department, Hospital Universitari de Bellvitge, IDIBELL, L'Hospitalet de Llobregat, Barcelona; and
  4. 4Bioinformatics and Genomics Program, Centre de Regulació Genòmica (CRG)–Universitat Pompeu Fabra (UPF), Barcelona, Spain

Abstract

The CD40-CD154 dyad seems to play a prominent role fostering the immune-inflammatory response triggered by endothelial cell (EC)–T-cell communication. To delineate comprehensively the involvement of CD40 (TNFRSF5) in EC activation, we combined RNAi-mediated CD40 knockdown with comparative genome-wide transcriptional profiling of ECs interacting with (CD154+) T cells. We report the initiation of a profound stress response in ECs upon CD40-CD154 engagement through early up-regulation of, among others, the major proinflammatory NF-κB and MAPK/SAPK pathways and their associated transcription factors. Moreover, we have identified novel genes regulated through the CD40-CD154 interaction, and pathways previously unrecognized to be induced by CD40 signaling in ECs. Thus, we document a significant down-regulation of endothelial APLN by CD40-CD154 interaction, TNFα/IFNγ exposure, and in immune-inflammatory pathologies, which could lead to hemodynamic dysfunction. Conversely, CD40-mediated up-regulation of the viral immune surveillance system, notably TLR3, IFIH1, RIG-I, and RNASEL, establishes a reverse link from adaptive to innate immunity in ECs. Moreover, systematic enrichment analysis substantiates endothelial CD40 involvement in the transcriptional regulation of gene networks associated with adhesion and motility, immunity, cell fate control, hemostasis, and metabolism. Our study also highlights the anti-inflammatory potential of RNAi-mediated CD40 inhibition, and the relevance of CD40 signaling for therapeutic intervention.

  • Submitted March 3, 2008.
  • Accepted July 24, 2008.
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