Macrophages and fibroblasts express embryonic fibronectins during cutaneous wound healing.

摘要: Fibronectins (FN) comprise a family of adhesive glycoproteins that are prominent components wound healing. These proteins arise by alternative splicing single gene transcript at three sites, termed EIIIA, EIIIB, and V. Extravasated plasma FN, which lacks the EIIIA EIIIB domains, along with fibrin, "provisional" matrix forms within minutes tissue injury. By 2 days after cutaneous excisional wounding in rats, total FN messenger RNA (mRNA) expression is increased locally dramatically surrounding dermis, subjacent muscle (panniculus carnosus) and, notably, margins. Moreover, contrast to normal skin, 2-day wounds express EIIIA- EIIIB-containing "embryonic" mRNAs. To identify cells responsible for synthesizing various isoforms, we performed situ hybridization probes Collagen lysozyme were employed distinguish fibroblasts from macrophages. At early intervals (2 days) wounding, macrophages principal expressed mRNA. many these embryonic 7 10 days, when defect was maturing, major FNs. It widely accepted phagocytose debris provide degradative enzymes cytokines essential stages repair. Our findings suggest an additional function macrophages--synthesis FNs providing extracellular facilitates repair, perhaps promoting cell migration.