[Osteogenic differentiation of human bone marrow stromal cells (hBMSC) by cyclic longitudinal mechanical strain and dexamethasone].
OBJECTIVE
The aim of the study was to investigate the effects of dexamethasone and cyclic mechanical strain on human bone marrow stromal cells (hBMSCs) in osteogenic differentiation by determing levels of mRNA of collagen I, II, III, tenascin C and Cbfa1.


METHODS
hBMSCs from seven donors (32.5 +/- 6.2 years old) were cultivated with (D +) or without (D -) dexamethasone. After the second passage 2.2 x 10 (5) cells were seeded on flexible silicon dishes. A cyclic mechanical strain with an elongation of 2 % (D + 2; D - 2) or 8 % (D + 8; D - 8) was applied for three days with a stimulation time of three times for two hours each day. Cells were harvested on day 1, day 1 after stress (day 4) and day 4 after stress (day 7). mRNA expression of collagen I, II, III, tenascin C and Cbfa1 was investigated by RT-PCR.


RESULTS
Cbfa1 mRNA levels were significantly different on different days (p < 0.05), and for strain on day 1: 8 %: 0.0291 +/- 0.0338 versus 0 %: 0.00 528 +/- 0.0127, p = 0.017; day 8: 8 %: 0.0411 +/- 0.116, 0 %: 0.00 103 +/- 0.00 217, p = 0.009. All other observed paramaters showed tendencies without significant differences.


CONCLUSIONS
In the short-term over seven days, cyclic stretching is a stronger differentiation factor than dexamethasone.
Unfallchirurgische Klinik, Medizinische Hochschule Hannover. haasper.carl@mh-hannover.de
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Haasper
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Drescher
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Hesse
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Krettek
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Zeichen
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Jagodzinski
D000328:Adult; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003907:Dexamethasone / Q000008:administration & dosage*; D004548:Elasticity; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D013314:Stress, Mechanical
D005938:Glucocorticoids; D003907:Dexamethasone
Osteogene Differenzierung von humanen stromalen Zellen aus dem Knochenmark (hBMSC) unter dem Einfluss von zyklischem mechanischem Dehnungsstress und Dexamethason.