Meeting Abstract
P3.143 Tuesday, Jan. 6 ELECTROMAGNETIC FIELDS PROMOTE REGENERATION FOLLOWING INJURY: INDUCTION OF INCREASED hsp70 LEVELS AND BINDING OF INJURY-SPSECIFIC FACTORS IN THE MAPK CASCADE LIN-YE, A; PANTAZATOS, S; GEDDIS, MS; AMBRON, RT; GOODMAN, RM*; Columbia University; Columbia University; BMCC-CUNY, Columbia University; Columbia University; Columbia University rmg5@columbia.edu
Electromagnetic fields (EMFs) are used medically to promote tissue repair, but the molecular pathways by which this occurs are only beginning to be understood. EMFs are known to up-regulate the heat shock gene HSP70 and to induce elevated levels of hsp70 protein. The activation of HSP70 occurs through the binding of heat shock factor 1 (HSF 1) to a heat shock element (HSE) in the region of the HSP70 promoter that contains three nCTCTn consensus sequences. These sequences are distinct from the sequences involved in thermal response and do not respond to elevated temperature. In this set of experiments Planaria were transected equidistant between the head and the tail. Individual head and tail portions were exposed to a 60 Hertz 80 milliGauss EMF for one hour, 2x a day for 15 days post-transection. The regenerating heads and tails were photographed and lengths were measured at 3-day intervals. In some experiments protein lysates were analyzed for hsp70 levels, doubly phosphorylated (pp)-ERK, Elk-1 kinase activity, and SRF-SRE binding, using either Western blot or EMSA. During the initial 3 days post-transection, EMF exposure caused a significant increase in regeneration for both heads and tails — more so for tails. Concurrently, EMF-exposed heads and tails exhibited an elevation in the level of hsp70 protein, activation of an ERK cascade and an increase in SRF-SRE binding. Our results indicate that a well-defined EMF promotes regeneration in Planaria accompanied by an increase in hsp70 levels and the activation of kinases and transcription factors that are typically associated with repair mechanisms. These findings provide insight into the clinical application of EMFs. Support provided by the Robert I. Goodman Fund.
