title: Dynamic cell stretching increases human osteoblast proliferation and CICP synthesis but decreases osteocalcin synthesis and alkaline phosphatase activity.
abstract: The cell activity of human-bone-derived cell cultures was studied after mechanical stimulation by cyclic strain at a magnitude occurring in physiologically loaded bone tissue. Monolayers of subconfluently grown human-bone-derived cells were stretched in rectangular silicone dishes with cyclic predominantly uniaxial movement along their longitudinal axes. Strain was applied over two days for 30 min per day with a frequency of 1 Hz and a strain magnitude of 1000 microstrain. Cyclic stretching of the cells resulted in an increased proliferation (10-48%) and carboxyterminal collagen type I propeptide release (7-49%) of human-cancellous bone-derived osteoblasts while alkaline phosphatase activity and osteocalcin release were significantly reduced by 9-25 and 5-32%, respectively. These results demonstrate that cyclic strain at physiologic magnitude leads to an increase of osteoblast activities related to matrix production while those activities which are characteristic for the differentiated osteoblast and relevant for matrix mineralization are decreased.
authors.affiliation: Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm, Germany. daniela.kaspar@medizin.uni-ulm.de
authors.forename: D
authors.initials: D
authors.lastname: Kaspar
authors.forename: W
authors.initials: W
authors.lastname: Seidl
authors.forename: C
authors.initials: C
authors.lastname: Neidlinger-Wilke
authors.forename: A
authors.initials: A
authors.lastname: Ignatius
authors.forename: L
authors.initials: L
authors.lastname: Claes
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D001696:Biomechanical Phenomena; D001857:Bone Matrix / Q000378:metabolism; D002113:Calcification, Physiologic; D002455:Cell Division; D002478:Cells, Cultured; D006801:Humans; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D015675:Osteocalcin / Q000096:biosynthesis*; D010446:Peptide Fragments / Q000096:biosynthesis*; D011347:Procollagen / Q000096:biosynthesis*; D013314:Stress, Mechanical
chemical_list: D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; D000469:Alkaline Phosphatase