Platelet-derived growth factor B chain promoter contains a cis-acting fluid shear-stress-responsive element.

摘要: The endothelial lining of blood vessels is constantly exposed to fluid mechanical forces generated by flowing blood. In vitro application shear stresses cultured cells influences the expression multiple genes, as reflected changes in their steady-state mRNA levels. We have utilized B chain platelet-derived growth factor (PDGF-B) a model investigate mechanisms shear-stress-induced gene regulation bovine aortic (BAECs). Northern blot analysis revealed elevated endogenous PDGF-B transcript levels BAECs, after exposure physiological level laminar stress (10 dynes/cm2; 1 dyne = 100 mN) for 4 h. A transfected reporter gene, consisting 1.3-kb fragment human promoter coupled chloramphenicol acetyltransferase (CAT), indicated direct effect on transcriptional activity. Transfection series PDGF-B-CAT deletion mutants led characterization cis-acting component within that was necessary shear-stress responsiveness. gel-shift assays, overlapping oligonucleotide probes this region formed several protein-DNA complexes with nuclear extracts prepared from both static and shear-stressed BAECs. 12-bp (CTCTCAGAGACC) identified distinct pattern proteins extracted This shear-stress-responsive element does not encode binding sites any known transcription but contain core sequence (GAGACC), defined mutation assays. Interestingly, putative site also present promoters certain other including tissue plasminogen activator, intercellular adhesion molecule 1, transforming beta are induced stress. Thus, pathophysiologically relevant genes vascular endothelium appears be regulated, part, factors interacting common element.