ABSTRACT
<p><b>OBJECTIVE</b>To explore the differentially expressed genes and related signaling pathways in MC3T3-E1 osteo- blasts in response to suitable fluid shear stress values and action time with cDNA microarrays.</p><p><b>METHODS</b>MC3T3-E1 cells cultured on a cover slip were subjected to fluid shear stress using a parallel plate flow chamber. The harvested RNA was used for microarray hybridization comprising approximately 44 170 genes, as well as for the subsequent real-time quantitative polymerase chain reaction validation of expression levels for selected genes. Microarray results were analyzed by using both GO and Pathway analysis.</p><p><b>RESULTS</b>Microarray analysis indicated that 884 differentially expressed genes were found. Among these genes, 444 were upregulated, whereas 440 were downregulated. The Notch signal and RIG- I -like receptor signaling pathways were involved in the Pathway analysis. GO analysis mainly involved different functional classifications, such as prostaglandin biosynthesis, nitric oxide-mediated signal transduction, calcium mediated signal, and cellular immune response, among others.</p><p><b>CONCLUSION</b>The mechanism underlying the protective effect of fluid shear stress on MC3T3-E1 cells might be related to promoting cell survival- and inhibiting cell apoptosis-related signaling pathways and biological processes.</p>
Subject(s)
Humans , Apoptosis , Calcium , Oligonucleotide Array Sequence Analysis , Osteoblasts , Signal Transduction , Stress, MechanicalABSTRACT
<p><b>OBJECTIVE</b>To explore the suitable level and action time of 17-beta estradiol and fluid shear stress (FSS) and their combined effect on the proliferation of rat osteoblasts in vitro.</p><p><b>METHODS</b>MC3T3-E1 osteoblasts were adopted after subcultured and different concentrations of 17-beta estradiol and FSS values were applied respectively on MC3T3-E1, the suitable level of 17-beta estradiol and FSS were selected through MTT and alkaline phosphatase (ALP). Then the two factors at the suitable level were applied simultaneously to MC3T3-E1 to detect the proliferation activity.</p><p><b>RESULTS</b>Seventeen-beta estradiol(10(-8) mol x L(-1) for 5 d and 12 x 10(-5) N FSS for 60 min exhibited better effects on the proliferation activity than the other groups respectively, and the combined effect of both factors was better than any single-factor treated group.</p><p><b>CONCLUSION</b>Both 17-beta estradiol and FSS have a suitable threshold in promoting proliferation of osteoblasts, and two-factor treated group exhibits better effect than any other single-factor treated groups. Therefore 17-beta estradiol and FSS have a synergetic action on differentiation and proliferation of osteoblasts.</p>