Expression of transforming growth factor beta(1), beta(3), and basic fibroblast growth factor in full-thickness skin wounds of equine limbs and thorax.
OBJECTIVE
To map the expression of transforming growth factor (TGF)-beta(1), TGF-beta(3), and basic fibroblast growth factor (bFGF) in full-thickness skin wounds of the horse. To determine whether their expression differs between limbs and thorax, to understand the pathogenesis of exuberant granulation tissue.


METHODS
Six wounds were created on one lateral metacarpal area and one midthoracic area of each horse. Sequential wound biopsies allowed comparison of the temporal expression of growth factors between limb and thoracic wounds.


METHODS
Four 2- to 4-year-old horses.


METHODS
Wounds were assessed grossly and histologically at 12 and 24 hours, and 2, 5, 10, and 14 days postoperatively. ELISAs were used to measure the growth factor concentrations of homogenates of wound biopsies taken at the same timepoints.


RESULTS
TGF-beta(1) peaked at 24 hours in both locations and returned to baseline in thoracic wounds by 14 days but remained elevated in limb wounds for the duration of the study. Expression kinetics of TGF-beta(3) differed from those of TGF-beta(1). TGF-beta(3) concentrations gradually increased over time, showing a trend toward an earlier and higher peak in thoracic compared with limb wounds. bFGF expression kinetics resembled those of TGF-beta(1), but no statistically significant differences existed between limb and thoracic wounds.


CONCLUSIONS
Growth factor expression is up-regulated during normal equine wound repair. TGF-beta(1) and TGF-beta(3) show a reciprocal temporal regulation. Statistically significant differences exist between limb and thoracic wounds with respect to TGF-beta(1) expression.


CONCLUSIONS
The persistence of TGF-beta(1) expression in leg wounds may be related to the development of exuberant granulation tissue in this location, because TGF-beta(1) is profibrotic.
Theoret
C L
CL
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, Saskatoon, Saskatchewan, Canada.
Barber
S M
SM
Moyana
T N
TN
Gordon
J R
JR
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005121:Extremities; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis*; D006736:Horses / Q000378:metabolism*; D008297:Male; D012867:Skin / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D013909:Thorax; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; D014945:Wound Healing; D014947:Wounds and Injuries / Q000378:metabolism / Q000662:veterinary*
D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; D016222:Fibroblast Growth Factor 2