BioProject

Rationale: During excessive pressure or overload, cardiac cells are subjected to increased mechanical stress. More...

Rationale: During excessive pressure or overload, cardiac cells are subjected to increased mechanical stress. We investigate how the stress response of cardiac cells to mechanical stress can be compared to genotoxic stresses induced by DNA damaging agents. Methods: Cultures enriched for cardiomyocytes and cultures of fibroblasts were derived from ventricles of neonatal rat hearts. In three independent experiments, both cell cultures were subjected to mechanical stress (cyclic stretch at 60 cycles/min), UV irradiation (10 J/m2), or X-rays (8.5 Gy). Cells were harvested 24 h. after (the onset of) treatment. Total RNA was isolated using an RNeasy® kit (Qiagen). Single stranded cDNA was synthesized from RNA from myocyte-enriched populations (10-14 microgram) and populations of fibroblasts (7.5-14 microgram), using Superscript II reverse transcriptase and T7-oligo(dT)24 primers at 42ºC for 1 h. Double stranded cDNA was obtained by using DNA ligase, DNA polymerase I and RNAse H at 16ºC for 2 h, followed by T4 DNA polymerase at 16ºC for 5 min. cRNA was synthesized from cDNA using the BioArray HighYield® RNA transcript labeling kit (Enzo) in the presence of biotin-labeled CTP and UTP. cRNA was fragmented in a buffer containing 40 mM Tris-acetate (pH 8.1), 100 mM KAc and 30 mM MgAc, at 94ºC for 35 min. Fragmented cRNA was hybridized to GeneChip RG-U34A arrays (Affymetrix) at 45ºC for 16 h. Arrays were washed and incubated with a streptavidin-phycoerythrin complex. Fluorescent signals were determined with a GeneChip scanner. Keywords: other Less...