title: Pulmonary artery smooth muscle cell senescence is a pathogenic mechanism for pulmonary hypertension in chronic lung disease.
abstract: BACKGROUND
  Senescence of pulmonary artery smooth muscle cells (PA-SMCs) caused by telomere shortening or oxidative stress may contribute to pulmonary hypertension associated with chronic lung diseases.
  
  
  OBJECTIVE
  To investigate whether cell senescence contributes to pulmonary vessel remodeling and pulmonary hypertension in chronic obstructive pulmonary disease (COPD).
  
  
  RESULTS
  In 124 patients with COPD investigated by right heart catheterization, we found a negative correlation between leukocyte telomere length and pulmonary hypertension severity. In-depth investigations of lung vessels and derived cultured PA-SMCs showed greater severity of remodeling and increases in senescent p16-positive and p21-positive PA-SMCs and proliferating Ki67-stained cells in 14 patients with COPD compared to 13 age-matched and sex-matched control subjects who smoke. Cultured PA-SMCs from COPD patients displayed accelerated senescence, with fewer cell population doublings, an increased percentage of β-galactosidase-positive cells, shorter telomeres, and higher p16 protein levels at an early cell passage compared to PA-SMCs from controls. Both in situ and in vitro PA-SMC senescence criteria correlated closely with the degree of pulmonary vessel wall hypertrophy. Because senescent PA-SMCs stained for p16 and p21 were virtually confined to the media near the Ki67-positive cells, which predominated in the neointima and hypertrophied media, we evaluated whether senescent cells affected normal PA-SMC functions. We found that senescent PA-SMCs stimulated the growth and migration of normal target PA-SMCs through the production and release of paracrine soluble and insoluble factors.
  
  
  CONCLUSIONS
  PA-SMC senescence is an important contributor to the process of pulmonary vascular remodeling that underlies pulmonary hypertension in chronic lung disease.
authors: INSERM U955, Hôpital Henri Mondor, AP-HP, Créteil, France.
authors: Hibo
authors: H
authors: Noureddine
authors: Guillaume
authors: G
authors: Gary-Bobo
authors: Marco
authors: M
authors: Alifano
authors: Elisabeth
authors: E
authors: Marcos
authors: Mirna
authors: M
authors: Saker
authors: Nora
authors: N
authors: Vienney
authors: Valérie
authors: V
authors: Amsellem
authors: Bernard
authors: B
authors: Maitre
authors: Ari
authors: A
authors: Chaouat
authors: Christos
authors: C
authors: Chouaid
authors: Jean-Luc
authors: JL
authors: Dubois-Rande
authors: Diane
authors: D
authors: Damotte
authors: Serge
authors: S
authors: Adnot
mesh_terms: D000368:Aged; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology* / Q000503:physiopathology; D032389:Myocytes, Smooth Muscle / Q000473:pathology* / Q000502:physiology; D011651:Pulmonary Artery / Q000473:pathology* / Q000503:physiopathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology