Activation of telomerase by silica in rat lung

By measuring the activity of telomerase in a silica-instilled rat lung, the study found a significant increase in telomerase activity compared to that of the control. Pneumoconiosis displays the characteristics of fibroblast- proliferation and accumulation of collagen, which finally causes the pathol ogic changes of irreversible and progressive fibrosis of the lung. On the b asis of the hypothesis that cellular proliferation may trigger telomerase-a ctivity, the experiment was carried out with telomerase-activation in silic osis. Silica-instilled rat lungs showed increased activity of telomerase, w hich was measured by TRAP (telomeric repeat amplification protocol) assay, at the time of the 1st, 5th and 8th week after intratracheal instillation o f silica in vivo. However, no activity was shown in silica-co-cultured fibr oblast in vitro. By summarizing these results, the activity of telomerase i s thought to be a very sensitive marker for the evaluation of pathogenicity , showing cellular immortalization in an experimental silicosis model. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.