DEPTOR regulates vascular endothelial cell activation and proinflammatory and angiogenic responses

Blood. 2013 Sep 5;122(10):1833-42. doi: 10.1182/blood-2013-03-488486. Epub 2013 Jul 23.

Abstract

The maintenance of normal tissue homeostasis and the prevention of chronic inflammatory disease are dependent on the active process of inflammation resolution. In endothelial cells (ECs), proinflammation results from the activation of intracellular signaling responses and/or the inhibition of endogenous regulatory/pro-resolution signaling networks that, to date, are poorly defined. In this study, we find that DEP domain containing mTOR interacting protein (DEPTOR) is expressed in different microvascular ECs in vitro and in vivo, and using a small interfering RNA (siRNA) knockdown approach, we find that it regulates mammalian target of rapamycin complex 1 (mTORC1), extracellular signal-regulated kinase 1/2, and signal transducer and activator of transcription 1 activation in part through independent mechanisms. Moreover, using limited gene arrays, we observed that DEPTOR regulates EC activation including mRNA expression of the T-cell chemoattractant chemokines CXCL9, CXCL10, CXCL11, CX3CL1, CCL5, and CCL20 and the adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 (P < .05). DEPTOR siRNA-transfected ECs also bound increased numbers of peripheral blood mononuclear cells (P < .005) and CD3+ T cells (P < .005) in adhesion assays in vitro and had increased migration and angiogenic responses in spheroid sprouting (P < .01) and wound healing (P < .01) assays. Collectively, these findings define DEPTOR as a critical upstream regulator of EC activation responses and suggest that it plays an important role in endogenous mechanisms of anti-inflammation and pro-resolution.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism
  • Cell Communication / genetics
  • Chemokines / genetics
  • Chemokines / metabolism
  • Gene Expression Regulation
  • HEK293 Cells
  • Human Umbilical Vein Endothelial Cells / enzymology
  • Human Umbilical Vein Endothelial Cells / pathology*
  • Humans
  • Inflammation / genetics
  • Inflammation / pathology*
  • Inflammation Mediators / metabolism
  • Intracellular Signaling Peptides and Proteins
  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Multiprotein Complexes / metabolism
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / pathology*
  • Protein Binding
  • STAT1 Transcription Factor / metabolism
  • Signal Transduction / genetics
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Cell Adhesion Molecules
  • Chemokines
  • Inflammation Mediators
  • Intracellular Signaling Peptides and Proteins
  • Multiprotein Complexes
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • DEPTOR protein, human
  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • TOR Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinase 3