Angina Research Today is a free monthly online journal that collates and summarizes the latest research about Angina, including details on symptoms, treatment, causes, prevention, surgery. | ||||||||
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High telomerase activity in neutrophils from unstable coronary plaques.Narducci ML, Grasselli A, Biasucci LM, Farsetti A, Mulè A, Liuzzo G, La Torre G, Niccoli G, Mongiardo R, Pontecorvi A, Crea F Institute of Cardiology, Catholic University of Sacred Heart, Rome, Italy. lianarducci@yahoo.it OBJECTIVES: 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. Published 24 December 2007 in J Am Coll Cardiol, 50(25): 2369-74.
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