ELECTRICAL-STIMULATION INDUCES THE LEVEL OF TGF-BETA-1 MESSENGER-RNA IN OSTEOBLASTIC CELLS BY A MECHANISM INVOLVING CALCIUM CALMODULIN PATHWAY/

It is well-known that electrical stimulation can prompt healing of bon e fractures. However, the mechanism involved is less clear. In this st udy, we found that capacitively coupled electric field-induced prolife ration of osteoblastic cells (MC3T3-E1) accompanied increased levels o f transforming growth factor-beta 1 (TGF-beta 1) mRNA determined by qu antitative reverse transcription/polymerase chain reaction. Previous r eports have shown that verapamil and W-7, both of which block voltage gated calcium channels and inhibit the activation of cytosolic calmodu lin, respectively, blocked capacitively coupled electric field-induced proliferation of the osteoblast cells. Interestingly, we found that v erapamil and W-7 can also block capacitively coupled electric field-in duced elevation of TGF-beta 1 mRNA. This result suggested that electri cal stimulation induces the level of TGF-beta 1 mRNA in osteoblastic c ells by a mechanism involving calcium/calmodulin pathway, The potentia l roles of TGF-beta in the electrical signal-induced osteogenesis was discussed. (C) 1997 Academic Press.