title: In vitro cultured fetal fibroblasts have myofibroblast-associated characteristics and produce a fibrotic-like environment upon stimulation with TGF-β1: Is there a thin line between fetal scarless healing and fibrosis?
abstract: Transforming growth factor-β (TGF-β) is a cytokine occurring in three isoforms with an important function in development and wound healing. In wound healing, prolonged TGF-β signaling results in myofibroblast differentiation and fibrosis. In contrast, the developing second-trimester fetal skin contains high levels of all three TGF-β isoforms but still has the intrinsic capacity to heal without scarring. Insight into TGF-β signal transduction during fetal wound healing might lead to methods to control the signaling pathway during adult wound healing. In this study, we imitated wound healing in vitro by stimulating fibroblasts with TGF-β1 and examining myofibroblast differentiation. The aim was to gain insight into TGF-β signaling in human fibroblasts from fetal and adult dermis. First, TGF-β1 stimulation resulted in similar or even more severe upregulation of myofibroblast-associated genes in fetal fibroblasts compared to adult fibroblasts. Second, fetal fibroblasts also had higher protein levels of myofibroblast-marker α-smooth muscle actin (α-SMA). Third, stimulated fetal fibroblasts in collagen matrices had higher protein levels of α-SMA, produced more of the fibrotic protein fibronectin splice-variant extra domain A (FnEDA), and showed enhanced contraction. Finally, fetal fibroblasts also produced significant higher levels of TGF-β1. Altogether, these data show that in vitro cultured fetal fibroblasts have myofibroblast-associated characteristics and do produce a fibrotic environment. As healthy fetal skin has high levels of TGF-β1, FnEDA, and collagen-III as well, these findings correlate with the in vivo situation. Therefore, our study demonstrates that there are similarities between fetal skin development and fibrosis and shows the necessity to discriminate between these processes.
authors.affiliation: Department of Molecular Cell Biology and Immunology (MCBI), VU University Medical Center (VUmc), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands.|Association of Dutch Burn Centres (ADBC), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-7289-8038
authors.initials: M
authors.lastname: Walraven
authors.affiliation: Department of Molecular Cell Biology and Immunology (MCBI), VU University Medical Center (VUmc), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands.|Association of Dutch Burn Centres (ADBC), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Akershoek
authors.affiliation: Department of Molecular Cell Biology and Immunology (MCBI), VU University Medical Center (VUmc), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands.
authors.forename: R H J
authors.initials: RH
authors.lastname: Beelen
authors.affiliation: Association of Dutch Burn Centres (ADBC), Zeestraat 27-29, Beverwijk, 1941 AJ, Amsterdam, The Netherlands. mulrich@burns.nl.
authors.forename: M M W
authors.initials: MM
authors.lastname: Ulrich
mesh_terms: D000199:Actins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D002921:Cicatrix / Q000473:pathology; D024061:Collagen Type III / Q000378:metabolism; D020405:Dermis / Q000473:pathology; D005333:Fetus / Q000166:cytology; D005353:Fibronectins / Q000378:metabolism*; D005355:Fibrosis / Q000473:pathology*; D006801:Humans; D058628:Myofibroblasts / Q000166:cytology* / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology*
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D024061:Collagen Type III; D005353:Fibronectins; D053773:Transforming Growth Factor beta1; C000593306:fibronectinEDA, human
keywords: Fetal fibroblast; Fibrosis; Myofibroblast; Scarless fetal wound healing; Transforming growth factor-β (TGF-β)