CD40 ligand increases expression of its receptor CD40 in human coronary artery endothelial cells

Surgery. 2006 Aug;140(2):236-42. doi: 10.1016/j.surg.2006.03.016.


Background: Recently, CD40 ligand (CD40L) and its receptor CD40 have been implicated in atherosclerosis. Clinical data showed that elevated CD40L levels are associated with a high risk of cardiovascular events. The aim of this study was to investigate whether CD40L could affect the expression of its membrane receptor CD40 as a feedback mechanism by which CD40L could enhance its functions in human coronary artery endothelial cells (HCAECs).

Methods: The HCAECs were treated with human soluble CD40L, and the messenger RNA (mRNA) and protein levels of CD40 were determined by real-time polymerase chain reaction and Western blot analysis, respectively. The specific effect of CD40L was confirmed by a blocking experiment with antibody against CD40L. Involvements of oxidative stress and mitogen-activated protein kinases (MAPKs) were also studied with antioxidant seleno-L-methionine (SeMet) and MAPK inhibitors such as extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor.

Results: When HCAECs were cultured with CD40L (5 microg/mL) for 24 hours, CD40 mRNA levels were increased by 79% compared with controls (P < .05). Similarly, Western blot analysis showed an 80% increase in CD40 protein levels (P < .05). The CD40L-induced increase in CD40 mRNA levels were blocked specifically by anti-CD40L antibody. Antioxidant SeMet and specific ERK1/2 inhibitor (PD98059) also effectively blocked CD40L-induced CD40 mRNA increase.

Conclusions: These data demonstrate that clinically relevant concentration of CD40L increased the expression of its receptor CD40 in HCAECs. The CD40L-induced upregulation of CD40 may be mediated by oxidative stress and ERK1/2 activation. This study suggests a new mechanism by which CD40L could enhance its biologic functions in the vascular system and contribute to endothelial dysfunction and vascular disease.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antioxidants / pharmacology
  • CD40 Antigens / genetics
  • CD40 Antigens / metabolism*
  • CD40 Ligand / pharmacology*
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Cell Culture Techniques
  • Coronary Vessels / cytology
  • Coronary Vessels / drug effects*
  • Coronary Vessels / metabolism
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism*
  • Feedback, Physiological / drug effects*
  • Flavonoids / pharmacology
  • Humans
  • RNA, Messenger / metabolism
  • Selenomethionine / pharmacology


  • Antioxidants
  • CD40 Antigens
  • Flavonoids
  • RNA, Messenger
  • CD40 Ligand
  • Selenomethionine
  • Calcium-Calmodulin-Dependent Protein Kinases
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one