Transforming growth factor beta 3 (TGF beta 3) accelerates wound healing without alteration of scar prominence. Histologic and competitive reverse-transcription-polymerase chain reaction studies.
BACKGROUND
Transforming growth factor (TGF) beta 3 is a new isoform of the TGF beta superfamily and is presumed to play an important role in wound repair and scarring.


OBJECTIVE
To examine the effects of TGF beta 3 on wound healing and on reducing scarring.


METHODS
Dermal ulcers were created on the ears of 75 anesthetized young female rabbits. Either TGF beta 3 or vehicle was applied topically to the wounds. Wounds were bisected and analyzed histologically at postwounding day 7. A second group of wounds was treated with topical TGF beta 3 and TGF beta 2 or vehicle at days 0 and 3 and harvested at days 21 through 42 as an excessive scarring model. The third group of wounds was treated with TGF beta 1, TGF beta 2, and TGF beta 3 and vehicle. The granulation tissue was harvested at day 7, and cellular RNA was extracted for performing competitive reverse-transcription polymerase chain reaction.


METHODS
The amount of new epithelium and granulation tissue was measured in TGF beta 3- and vehicle-treated wounds. The hypertrophic index was calculated for scarring wounds treated with TGF beta 2 and TGF beta 3 or vehicle. Levels of TGF beta 1 messenger RNA were measured in those wounds that were treated with TGF beta 1, TGF beta 2, and TGF beta 3 and in their controls.


RESULTS
The use of TGF beta 3 (0.3-0.75 microgram per wound) increased granulation tissue formation by more than 100% (P < .005). Epithelialization showed a biphase, either increasing 30% (P < .04) or decreasing 25% (P < .001) dependent on dose. No significant difference in the hypertrophic index was noted in TGF beta 3-treated wounds compared with controls. Levels of TGF beta 1 messenger RNA increased (7.1- to 14.9-fold) in those wounds treated with TGF beta s compared with controls at day 7.


CONCLUSIONS
Exogenous TGF beta 3 displays substantial vulnerary properties in wound healing and may be useful in treating nonhealing wounds. However, the observation that TGF beta 3 can reduce scarring was not confirmed in this study, and the messenger RNA level in response to TGF beta 3 suggests that it behaves similarly to TGF beta 1.
Wu
L
L
Division of Plastic and Reconstructive Surgery, Northwestern University Medical School, Chicago, Ill, USA.
Siddiqui
A
A
Morris
D E
DE
Cox
D A
DA
Roth
S I
SI
Mustoe
T A
TA
D000818:Animals; D002921:Cicatrix / Q000473:pathology* / Q000503:physiopathology*; D017439:Cicatrix, Hypertrophic / Q000473:pathology / Q000503:physiopathology; D015342:DNA Probes; D005260:Female; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D012194:RNA-Directed DNA Polymerase; D011817:Rabbits; D012883:Skin Ulcer / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects*
D015342:DNA Probes; D016212:Transforming Growth Factor beta; D012194:RNA-Directed DNA Polymerase