title: Up-regulation of expression of selected genes in human bone cells with specific capacitively coupled electric fields.
abstract: The objective of the described experiments was to determine the electrical parameters that lead to optimal expression of a number of bone-related genes in cultured human bone cells exposed to a capacitively coupled electric field. Human calvarial osteoblasts were grown in modified plastic Cooper dishes in which the cells could be exposed to various capacitively coupled electric fields. The optimal duration of stimulation and optimal duration of response to the electrical field, and the optimal amplitude, frequency and duty cycle were all determined for each of the genes analyzed. Results indicated that a capacitively coupled electric field of 60 kHz, 20 mV/cm, 50% duty cycle for 2 h duration per day significantly up-regulated mRNA expression of a number of transforming growth factor (TGF)-β family genes (bone morphogenetic proteins (BMP)-2 and -4, TGF-β1, - β2 and -β3) as well as fibroblast growth factor (FGF)-2, osteocalcin (BGP) and alkaline phosphatase (ALP). Protein levels of BMP-2 and -4, and TGF-β1 and - β2 were also elevated. The clinical relevance of these findings in the context of a noninvasive treatment modality for delayed union and nonunion fracture healing is discussed.
authors.affiliation: Department of Orthopaedic Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Clark
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Carl T
authors.initials: CT
authors.lastname: Brighton
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004558:Electric Stimulation; D017102:Fracture Healing / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis; D012333:RNA, Messenger / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D019485:Bone Morphogenetic Proteins; D003470:Culture Media; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D000469:Alkaline Phosphatase
keywords: capacitive coupling; electrical stimulation; fracture healing; gene up-regulation; human bone cells