Nedelec B, Shen Y J, Ghahary A, Scott P G, Tredget E E
Department of Surgery, University of Alberta, Edmonton, Canada.
J Lab Clin Med. 1995 Nov;126(5):474-84.
Wound contraction is an essential component of wound healing. However, the development of scar contractures in tissues and organs disrupts normal organ integrity and produces functional deformities. Although interferons alpha and gamma inhibit extracellular matrix protein production by fibroblasts, their effects on cytoskeletal protein mediated-wound contraction are as yet unclear. The fibroblast-populated collagen lattice is an in vitro assay that simulates wound contraction. When matched pairs of human hypertrophic scar and normal dermal fibroblast cultures established from patients recovering from a thermal injury were used, interferon-alpha 2b exposure before lattice formation was found to significantly inhibit contraction in a treatment time-dependent manner (p < 0.05). Fibroblasts generated contractile forces that were triphasic and serum sensitive (p < 0.01). Comparison of hypertrophic scar and normal dermal fibroblasts revealed no significant differences in ability to induce lattice contraction. Northern blot analysis of mRNAs for the intracellular contractile proteins revealed that interferon-alpha 2b significantly down-regulated mRNA levels of the actin isoforms beta and gamma (50% to 60%) but had no significant effect on alpha-tubulin, vimentin, and alpha-actinin. Fibroblast-populated collagen lattices were stained with rhodamine-labeled phalloidin to reveal filamentous actin proteins. Marked morphologic alterations of the stress fibers were associated with reductions in lattice contraction after interferon-alpha 2b treatment. Thus interferon-alpha 2b's inhibition of wound contraction in vitro is associated with reductions in mRNA for beta and gamma actin and distinct morphologic alterations in fibroblast stress fiber morphology.
伤口收缩是伤口愈合的一个重要组成部分。然而，组织和器官中瘢痕挛缩的发展会破坏正常器官的完整性并导致功能畸形。尽管α干扰素和γ干扰素可抑制成纤维细胞产生细胞外基质蛋白，但其对细胞骨架蛋白介导的伤口收缩的影响尚不清楚。成纤维细胞填充的胶原晶格是一种模拟伤口收缩的体外试验。当使用从热损伤恢复患者建立的人增生性瘢痕和正常真皮成纤维细胞培养物的配对时，发现晶格形成前暴露于α干扰素2b可呈治疗时间依赖性地显著抑制收缩（p<0.05）。成纤维细胞产生的收缩力呈三相且对血清敏感（p<0.01）。增生性瘢痕和成纤维细胞的比较显示，诱导晶格收缩的能力没有显著差异。对细胞内收缩蛋白的mRNA进行Northern印迹分析表明，α干扰素2b显著下调了肌动蛋白异构体β和γ的mRNA水平（50%至60%），但对α微管蛋白、波形蛋白和α辅肌动蛋白没有显著影响。用罗丹明标记的鬼笔环肽对成纤维细胞填充的胶原晶格进行染色，以显示丝状肌动蛋白。α干扰素2b治疗后，应力纤维明显的形态学改变与晶格收缩的减少有关。因此，α干扰素2b在体外对伤口收缩的抑制作用与β和γ肌动蛋白mRNA的减少以及成纤维细胞应力纤维形态的明显改变有关。
