Transcriptional pathways induced by fluid shear stress in mouse preosteoblast cells.
Recent findings support the idea that fluid movement in the bone is a key factor in bone formation and related cellular responses. However, the precise molecular mechanisms are not known. Our data demonstrates that fluid shear stress is a key factor in the activation of specific transcriptional pathways in murine preosteoblast (MC3T3E1) cells. MC3T3E1 cells have increased expression of the egr-1 and p57kip2 genes after being subjected to 0.3 dynes/cm2 of fluid shear stress. The MC3T3E1 cells are already known to express egr-1, a multipotent transcription factor, after high levels of fluid shear stress, but this is the first demonstration of egr-1 expression after low levels of fluid shear stress. Moreover, this is the first study showing expression of p57kip2 by the MC3T3E1 cells after fluid shear stress. The expression of p57kip2, a cyclin dependent kinase inhibitor, is a strong indicator that the cells are exiting the cell cycle and are beginning to differentiate. Our data shows decreased 3H-thymidine incorporation up to 18 hours post stress, which agrees with the upregulation of p57kip2 as a result of fluid shear stress.
Billotte
W G
WG
Biology Department, University of Dayton, Dayton, OH 45469, USA.
Dumas
K
K
Hofmann
M C
MC
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D050761:Cyclin-Dependent Kinase Inhibitor p57; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D051766:Early Growth Response Protein 1; D004791:Enzyme Inhibitors / Q000378:metabolism; D017874:Immediate-Early Proteins; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010006:Osteoblasts / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D013314:Stress, Mechanical; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*
C493965:Cdkn1c protein, mouse; D050761:Cyclin-Dependent Kinase Inhibitor p57; D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors