title: High telomerase activity in neutrophils from unstable coronary plaques.
abstract: OBJECTIVE
  We evaluated telomerase activity in circulating polymorphonuclear neutrophils (PMN) and in PMN isolated from coronary atherosclerotic plaques by a novel approach.
  
  
  BACKGROUND
  Delayed apoptosis of PMN have been demonstrated in unstable angina (UA). These cells have a finite lifespan with low telomerase activity, a polymerase that extends telomeres, structures essential for cell aging. Reactivation of telomerase has been associated with resistance to apoptosis.
  
  
  METHODS
  We studied 20 patients with UA and 6 patients with chronic stable angina (SA), undergoing a percutaneous coronary intervention. Circulating PMN were isolated from venous blood and PMN derived from coronary plaque were isolated from washing medium of angioplasty balloons.
  
  
  RESULTS
  Telomerase activity was higher in coronary plaque PMN of UA patients than in coronary plaque PMN of SA patients (122.7, range 20.5 to 3,696; and 47.7, range 16 to 212.6, respectively, p = 0.001) and higher than in peripheral PMN of SA patients (122.7, range 20.5 to 3,696 vs. 59, range 16.5 to 132.5, p = 0.001). We found a statistically significant difference between venous and coronary plaque PMN telomerase activity in UA patients (z = -2.875; p = 0.004). Among UA patients, a shorter time interval from symptom onset to coronary PMN sampling was the only independent predictor of high telomerase activity in coronary plaque PMN (p < 0.001, R2 = 0.75).
  
  
  CONCLUSIONS
  In UA patients, telomerase activity is high in coronary plaque PMN, while it is low in peripheral PMN. Telomerase reactivation in resident PMN resulting in a prolonged lifespan might play a key role in the early phases of instability.
authors.affiliation: Institute of Cardiology, Catholic University of Sacred Heart, Rome, Italy. lianarducci@yahoo.it
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Narducci
authors.forename: Annalisa
authors.initials: A
authors.lastname: Grasselli
authors.forename: Luigi Marzio
authors.initials: LM
authors.lastname: Biasucci
authors.forename: Antonella
authors.initials: A
authors.lastname: Farsetti
authors.forename: Antonino
authors.initials: A
authors.lastname: Mulè
authors.forename: Giovanna
authors.initials: G
authors.lastname: Liuzzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Torre
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Niccoli
authors.forename: Rocco
authors.initials: R
authors.lastname: Mongiardo
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pontecorvi
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000201:enzymology / Q000628:therapy; D000789:Angina, Unstable / Q000201:enzymology* / Q000628:therapy; D015906:Angioplasty, Balloon, Coronary; D017209:Apoptosis / Q000502:physiology; D016922:Cellular Senescence; D003324:Coronary Artery Disease / Q000201:enzymology* / Q000628:therapy; D003331:Coronary Vessels / Q000201:enzymology; D004789:Enzyme Activation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000201:enzymology*; D019098:Telomerase / Q000097:blood*; D016615:Telomere / Q000502:physiology
chemical_list: D019098:Telomerase