increased CTGF expression 80 fold, 60 fold, and 10 fold in E17, E19, and adult fibroblasts respectively (p .01 for each). TGF-beta 3 induced a 70 fold increase in CTGF expression in E17 fibroblasts, which was over 40 fold greater than the induction observed in E19 and adult fibroblasts (p0.02). CONCLUSIONS: E17 and E19 fibroblasts have lower CTGF ex- pression at baseline compared to adult fibroblasts. Early gestation fibroblasts increase CTGF expression to a greater degree than late gestation and adult fibroblasts after TGF-beta isoform stimula- tion, suggesting the signaling pathway for TGF-beta is functional early in development. Increased CTGF transcription in keloid fibroblasts requires cooperativity between AP-1 and SMAD binding sites Wei Xia MD, Wuyi Kong MD, PhD, Toan-Thang Phan MD, PhD, Ivor Lim MBBChir, FRCS, Michael T Longaker MD, MBA, FACS, George Yang MD, PhD Stanford University Stanford, CA INTRODUCTION: Keloids are proliferative dermal growths repre- senting a pathological wound-healing response. We have previously demonstrated increased serum induced transcription of connective tissue growth factor (CTGF) in keloid fibroblasts (KF) versus normal fibroblasts (NF). We present here an analysis of the mechanisms for increased CTGF transcription in KFs. METHODS: A series of 5’ CTGF promoter deletions were cloned into PGL3-basic luciferase reporter vector. CTGF promoter con- structs and pSV-beta-galactosidase vectors were co-transfected into KFs and NFs that were serum stimulated. Luciferase activity was normalized to beta-galactosidase activity. Nuclear extracts were har- vested before and after 1 hour of serum stimulation and used for gel mobility shift assays. Site-directed mutagenesis of CTGF promoter/ reporter gene constructs was performed using the QuikChange Site- directed Mutagenesis Kit. RESULTS: Promoter analysis demonstrated the fragment from -625/-140 conferred increased serum responsiveness. Mutational analysis of an AP-1 and Smad binding site in this fragment showed both were necessary for serum responsiveness. Gel shift analysis showed a specific band binding to the AP-1 site in KFs but not in NFs. A similar binding pattern is seen using the Smad binding site in KFs versus NFs. Supershift assay demonstrated c-Jun, which was a downstream transcription factor of JNK pathway, was able to bind the AP-1 site. CONCLUSIONS: Increased transcription of CTGF following se- rum stimulation in KFs requires both the AP-1 and SMAD binding site. Mutation of either of these two sites is sufficient to abolish the serum response of CTGF in KFs. These studies may identify new targets for the therapy of keloids. Micro-mechanical forces as a potent stimulator of wound healing Perry H Liu MD, Dae-Hyun Lew MD PhD, Horacio Mayer MD, Moritz A Konerding MD, Steven J Mentzer MD, FACS, Dennis P Orgill MD, FACS Brigham and Women’s Hospital Boston, MA INTRODUCTION: In vitro studies have shown that cells divide and proliferate in response mechanical stimuli. Using this knowledge, we hypothesized that Micro-mechanical Forces (MMFs), both cyclical and static, are capable of enhancing wound healing through stimu- lation of both angiogenesis and cellular proliferation. METHODS: The ears of Wistar Rats (n=15) were stretched using elastic connectors to apply 55g of continuous tension for 4 days. Cyclical tension was applied for 2 hours with 1 hour rest intervals. Vessel size and morphology were monitored using intravital micros- copy. After stimulation, ears were harvested for histology and VEGF immunohistochemistry. Vascular morphology and intravascular vol- ume were determined using Mercox Corrosion Casting and Evan’s Blue dye extraction, respectively. RESULTS: Both cyclical and static tension produced significant increases in vessel size. Rat ears subjected to static tension underwent a 110% increase in mean vessel diameters over their tension-free counterparts (p 0.001). When cycled periodically, significant changes were measurable after only a few hours (25% vs. 3%, p0.001), rather than 1-2 days. Stretched vessels demonstrated greater VEGF expression and had significant (p0.001) increases in extracted Evan’s Blue dye. Preliminary stretched vessel casts also ap- peared to be larger. CONCLUSIONS: MMFs are capable of inducing significant vascu- lar changes when applied cyclically or statically, with cyclical tension being more potent. Tension ears exhibited greater diameters, VEGF expression, and vascular perfusion. While the mechanisms have yet to be elucidated, these results suggest the crucial role of MMFs in regulating cellular growth and differentiation, as well as their poten- tial as a novel approach for enhancing wound healing. A novel replication-defective HSV-1 vector for regulatable gene delivery to wounds Christoph FP Theopold MD, Raphael Gheerardyn MD, Oliver Bleiziffer MD, Patrik E Velander MD, AFRCSI, FengYao PhD, Elof Eriksson MD, FACS Brigham and Women’s Hospital Boston, MA INTRODUCTION: Gene delivery of growth factors to wounds can accelerate healing but has so far not been achieved with any control over the level of transgene expression. Herpes viral vectors are effi- cient vehicles for in vivo gene delivery and have the advantage of being able to establish long-term gene expression in sensory neurons that are known to interact with the healing wound.To increase safety and control of in vivo gene-transfer we constructed a novel replication-deficient viral vector that for the first time allows efficient S57 Vol. 199, No. 3S, September 2004 Plastic Surgery I