Differentialexpression and regulation of extracellular matrix-associated genes in fetaland neonatal fibroblasts ANNA GOSIEWSKA, PhD; CHIN-FENG YI, MD; LAURA J. BROWN, BSc; BREDA CULLEN, PhD; DEREK SILCOCK, PhD; JEFFREY C. GEESIN, PhD Adults and neonates healwounds by a repair process associated with scarring in contrast to scar-free wound healing in the fetus. In the present study, human dermal fetal fibroblasts, representing the scarless phenotype, and neonatal human dermal fibroblasts, representing scar-forming phenotype, were examined for potential differences that might influence the wound healing process. Fetal fibroblasts secreted four- to tenfold more latent transforming growth factor- b1 depending on the cell strains compared. Fetal fibroblasts also produced higherlevels of collagen protein and mRNA for most types of collagen (particularly type III) as compared to neonatal cells. Interestingly, mRNA for type V collagen was significantly reduced in fetal cells. Neonatal fibroblasts expressed significantly higher levels of latent transforming growth factor-b1 binding protein mRNA, in contrast to almost undetectable levels in fetal fibroblasts. By ligand blot analysis, the levels of insulin-like growth factor binding protein-3, a reported mediator of transforming growth factor-b1 activity, was eightfold higher in neonatal versus fetalfibroblasts. Approximately 20 other mRNAs for various cytokines, matrix molecules and receptors were examined and found to be similar between the two cell types. The phenotypic differences described in this article may represent potentially important mechanisms to explain the differences in the quality of wound repair observed in fetal versus adult/neonatal tissues. (WOUND REP REG 2001;9:213–222 In adulthood and during neonatal development, wound BSA Bovine serum albumin healing occurs by a repair process that results in fibrotic DMEM Dulbecco’s modified Eagle’s medium scar tissue formation, which may impair tissue function ECM Extracellular matrix ELISA Enzyme-linked immunosorbent assay and growth. In contrast, the fetus is capable of healing GAPDH Glyceraldehyde 3-phosphate skin in a unique fashion, without scarring. The reasons dehydrogenase for these differences are not well known and determina- HA Hyaluronic acid tion of factors affecting the absence of scarring in the HPLC High performance liquid fetus may lead to strategies for controlling adult, patho- chromatography IGF Insulin-like growth factor logical scarring. The absence of scar formation in fetal IGFBP-3 IGF binding protein-3 wound healing has been correlated with the markedly LTBP-1 Latent TGF-b binding protein-1 different inflammatory response as compared to adults. M6P/IGF-IIR Mannose 6-phosphate/IGF-II receptor Even though the fetus is capable of mounting an inflam- MMP Matrix metalloproteinase matory response during fetal wound healing, neutrophils, PAI-I Plasminogen activator inhibitor-I lymphocytes and immunoglobulin deposition are virtu- PAR PA receptor PBS Phosphate buffered saline solution ally absentin contrastto adult wounds. 1 In addition, RT-PCR Reverse transcription-polymerase chain reaction SDS Sodium dodecyl sulfate SPARC Secreted protein acidic and rich in From Johnson & Johnson Wound Healing Technology Re- cysteine source Center, Skillman, New Jersey. SSC Saline sodium citrate Reprint requests:Dr. Anna Gosiewska, PhD, Johnson & TGF-b Transforming growth factor-b Johnson Wound Healing Technology Resource TSP Thrombospondin Center, 199 Grandview Road, RG-29, Skillman, NJ 08558-9418.Fax: 908-874-2701; Email: agosiew @cpus.jnj.com. 213