Endothelial cell death and decreased expression of vascular endothelial growth factor and vascular endothelial growth factor receptor 2 in emphysema

Am J Respir Crit Care Med. 2001 Mar;163(3 Pt 1):737-44. doi: 10.1164/ajrccm.163.3.2002117.


Emphysema due to cigarette smoking is characterized by a loss of alveolar structures. We hypothesize that the disappearance of alveoli involves apoptosis of septal endothelial cells and a decreased expression of lung vascular endothelial growth factor (VEGF) and its receptor 2 (VEGF R2). By terminal transferase dUTP nick end labeling (TUNEL) in combination with immunohistochemistry, we found that the number of TUNEL+ septal epithelial and endothelial cells/lung tissue nucleic acid (microg) was increased in the alveolar septa of emphysema lungs (14.2 +/- 2.0/microg, n = 6) when compared with normal lungs (6.8 +/- 1.3/microg, n = 7) (p < 0.01) and with primary pulmonary hypertensive lungs (2.3 +/- 0.8/microg, n = 5) (p < 0.001). The cell death events were not significantly different between healthy nonsmoker (7.4 +/- 1.9/microg) and smoker (5.7 +/- 0.7/microg) control subjects. The TUNEL results were confirmed by single-stranded DNA and active caspase-3 immunohistochemistry, and by DNA ligation assay. Emphysema lungs (n = 12) had increased levels of oligonucleosomal-length DNA fragmentation when compared with normal lungs (n = 11). VEGF, VEGF R2 protein, and mRNA expression were significantly reduced in emphysema. We propose that epithelial and endothelial alveolar septal death due to a decrease of endothelial cell maintenance factors may be part of the pathogenesis of emphysema.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Apoptosis*
  • Emphysema / genetics
  • Emphysema / metabolism*
  • Emphysema / pathology*
  • Endothelial Growth Factors / analysis
  • Endothelial Growth Factors / biosynthesis*
  • ErbB Receptors / analysis
  • ErbB Receptors / biosynthesis*
  • Female
  • Humans
  • In Situ Nick-End Labeling
  • Lymphokines / analysis
  • Lymphokines / biosynthesis*
  • Male
  • Middle Aged
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors


  • Endothelial Growth Factors
  • Lymphokines
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • ErbB Receptors