Effects of Hcy on half-life of cyclin A mRNA and gene transcription.
(A) mRNA half-life; HUVECs were exposed to dl-Hcy for 24 hours followed by administration of actinomycin D (ACD; 10 μg/mL; t = 0) to stop transcription. Total cellular RNA was extracted at indicated times and used for Northern analysis. The corrected signal density was plotted as a percentage of 0 hour value against time in log scale. The values represent the means ± SD from 3 independent experiments (n = 3). (B) Nuclear run-on experiment; HUVECs were exposed to dl-Hcy for 30 hours. Equal amounts of32P-labeled, in vitro–transcribed RNA probes from each group were hybridized to 1 μg denatured cyclin A and β-actin cDNA that had been immobilized on the nitrocellulose filters. The values represent the means ± SD from 3 independent experiments (n = 3). *P < .01 versus control.
