ABSTRACT
BACKGROUND: Fetal wounds can heal without any histological evidence of scarring. Fetal wounds lack the inflammatory infiltrate characteristic of adult wounds, and the fetal environment is not necessary for scarless healing to occur. Recent evidence suggests that fibroblasts are the main effector of scarless healing in fetal tissue. What has not been shown is what profile of growth factors the fibroblast uses to influence wound repair. OBJECTIVE: To determine the expression of growth factors (transforming growth factors beta1, beta2, and beta3; acidic and basic fibroblast growth factors; keratinocyte growth factor; and platelet-derived growth factor AA, BB, and AB) of fetal and adult fibroblasts in vitro. DESIGN: Adult and fetal fibroblasts were grown in culture, and messenger RNA was extracted by standard techniques. Northern hybridization was used to identify messenger RNA transcripts for the aforementioned growth factors. Densitometry was used to compare growth factor messenger RNA expression with that of a ubiquitously expressed control, glyceraldehyde phosphate dehydrogenase. RESULTS: The data suggest that fetal and adult fibroblasts express acidic and basic fibroblast growth factor and transforming growth factor beta1. Adult fibroblasts show twice the relative expression of these growth factors compared with fetal fibroblasts. CONCLUSIONS: The adult fibroblasts demonstrate a relative excess production of cytokines compared with fetal fibroblasts. This is thought to contribute to suboptimal wound healing in adult wounds compared with the scarless healing of fetal wounds.
Subject(s)
Fibroblasts/chemistry , Growth Substances/analysis , Adult , Autoradiography , Blotting, Northern/methods , Cell Line , Cells, Cultured , Fetus , Humans , Nucleic Acid Hybridization , RNA Probes , RNA, Messenger/analysis , RNA, Messenger/isolation & purification , Wound HealingABSTRACT
Keloids are an abnormal response to wound healing distinguished by an overproduction of collagen. Thickened bundles of collagen in the reticular dermis oriented haphazardly in relation to the overlying epithelium are found in keloids, in contrast to thinner collagen fibers in a more orderly arrangement that are found in normal scars. Previous clinical trials of intralesional interferon-gamma (IFN-G) injections by Larrabee et al. and Granstein et al. showed a decrease in lesion size. These findings led to a conclusion that IFN-G would be a useful adjunct to surgical excision of keloids to aid in preventing recurrence. We performed a double-blind, placebo-controlled trial in patients with two or more keloids treated with excision and subsequent local injections of IFN-G or placebo.
Subject(s)
Antineoplastic Agents/therapeutic use , Interferon-gamma/therapeutic use , Keloid/surgery , Keloid/therapy , Adolescent , Adult , Double-Blind Method , Female , Humans , Injections, Intradermal , Male , Middle Aged , Pilot Projects , Recombinant ProteinsABSTRACT
Wound healing research has produced some startling discoveries during the past decade. Foremost among these is the observation that cutaneous wounds created and healed in utero are histologically indistinguishable from intact, unwounded tissue. Observers have documented that the acute inflammatory response and endogenous immunoglobulins that characterize healing in human beings after birth are absent in the fetal wound. Determination of the cellular and biochemical differences between fetal and postdelivery wound healing offers the promise of improved control over the process of tissue repair. Another promise of fetal wound healing research is the option of in utero repair of defects such as cleft lip and palate. We review what is known at present about fetal wound healing.
