title: Effects of extremely low frequency electromagnetic field (EMF) on collagen type I mRNA expression and extracellular matrix synthesis of human osteoblastic cells.
abstract: Human osteoblastic cells were grown in a three-dimensional (3-D) cell culture model and used to test the effects of a 20 Hz sinusoidal electromagnetic field (EMF; 6 mT and 113 mV/cm max) on collagen type I mRNA expression and extracellular matrix formation in comparison with the effects of growth factors. The cells were isolated from trabecular bone of a healthy individual (HO-197) and from a patient presenting with myositis ossificans (MO-192) and grown in a collagenous sponge-like substrate. Maximal enhancement of collagen type I expression after EMF treatment was 3.7-fold in HO-197 cells and 5.4-fold in MO-192 cells. Similar enhancement was found after transforming growth factor-beta (TGF-beta) and insulin-like growth factor-I (IGF-I) treatment. Combined treatment of the cells with EMF and the two growth factors TGF-beta and IGF-I did not act synergistically. MO-192 cells produced an osteoblast-characteristic extracellular matrix containing collagen type I, alkaline phosphatase, and osteocalcin, together with collagen type III, TP-1, and TP-3, two epitopes of an osteoblastic differentiation marker. The data suggest that the effects of EMFs on osteoblastic differentiation are comparable to those of TGF-beta and IGF-I. We conclude that EMF effects in the treatment of skeletal disorders and in orthopedic adjuvant therapy are mediated via enhancement of collagen type I mRNA expression, which may lead to extensive extracellular matrix synthesis.
authors.affiliation: Institut für Molekulare Virologie, GSF-Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Heermeier
authors.forename: M
authors.initials: M
authors.lastname: Spanner
authors.forename: J
authors.initials: J
authors.lastname: Träger
authors.forename: R
authors.initials: R
authors.lastname: Gradinger
authors.forename: P G
authors.initials: PG
authors.lastname: Strauss
authors.forename: W
authors.initials: W
authors.lastname: Kraus
authors.forename: J
authors.initials: J
authors.lastname: Schmidt
mesh_terms: D002460:Cell Line; D003094:Collagen / Q000096:biosynthesis* / Q000235:genetics*; D004599:Electric Stimulation Therapy; D004574:Electromagnetic Fields; D004582:Electronics, Medical / Q000295:instrumentation; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D003094:Collagen