CONTRACTION INHIBITION PRECEDING DERMAL REGENERATION

真皮再生前的收缩抑制

• 批准号: 2187756
• 负责人: IOANNIS V YANNAS
• 金额: $ 13.33万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2187756
• 关键词: actins; artificial skin; ascorbate; biological models; chondroitin sulfates; collagen; copolymer; cytoskeleton; extracellular matrix; fibroblasts; immunoelectron microscopy; integrins; regeneration; scars; tissue /cell culture; wound healing

The proposed research is an in vitro study of wound contraction inhibition by certain well-characterized collagen-GAG (CG) matrices. A small class of these highly porous CG matrices have significantly delayed in vivo contraction and induced regeneration of a physiologic dermis in a rodent model in which the dermis does not regenerate spontaneously. Evidence suggests that inhibition of contraction is necessary for regeneration. An in vitro model consisting of fibroblast-populated porous CG matrices will be used to study the effects of carefully controlled extracellular matrix environments upon fibroblast behavior. The relationship between ECM receptor utilization (integrins), fibroblast activity (migration vs. contraction), and collagen topography (loose fibrils vs. densely packed collagen surfaces) will be established. Changes in integrin receptor utilization as determined by immunolocalization before and after the onset of contraction will be determined by light and electron microscopy. Immunoelectron microscopy will be used to co-localize specific integrin receptors to actin cytoskeletal elements of contractile fibroblasts in order to correlate receptor utilization to microfilament reorganization and collagen topography. This will test the hypothesis that porous CG matrices influence the utilization of receptors and the organization of cytoskeletal elements of fibroblasts thus controlling activities of migration and contraction. The effects of fibroblast mediated contraction and porous CG matrix architecture upon newly synthesized collagen fibril bundle organization will also be studied in long-term cultures supplemented with ascorbic acid. The degree of fibroblast contraction of porous CG matrices and the architecture of CG matrices will be independently varied in order to study their separate roles in collagen fiber bundle organization. This will allow determination of whether CG matrix alters the basic organization of newly synthesized connective tissue and whether the mechanical stress of wound contraction is the primary factor in aligning and compacting collagen fiber bundles into scar tissue. The effect of CG matrix upon the responsiveness of fibroblasts to growth factors known to increase collagen synthesis will also be determined. These are basic studies which will elucidate the molecular mechanism by which CG matrices inhibit contraction and the roles of contraction and CG matrix architecture upon organization of collagen fiber bundles in newly formed tissue. These studies will improve the understanding of the effects of cell-matrix interactions in normal wound healing events and in connective tissue regeneration.

拟议的研究是在体外研究伤口收缩 某些充分表征的胶原蛋白-GAG（CG）基质的抑制作用。 一 这些高度多孔的CG矩阵的小类显著延迟了 在体内收缩和诱导再生的生理真皮， 一种啮齿动物模型，其中真皮不能自发再生。 有证据表明，抑制收缩是必要的， 再生 一种由成纤维细胞聚集的 多孔CG矩阵将被用来仔细研究的影响， 控制细胞外基质环境对成纤维细胞行为的影响。 ECM受体利用（整合素）、成纤维细胞 活动（迁移与收缩）和胶原地形（松散 原纤维与密集堆积的胶原表面）。 通过以下方法测定的整合素受体利用率的变化 在收缩开始之前和之后的免疫定位将是 通过光学和电子显微镜测定。 免疫电镜 将用于将特异性整合素受体共定位于肌动蛋白 收缩性成纤维细胞的细胞骨架成分， 受体对微丝重组和胶原的利用 地形 这将检验多孔CG基质 影响受体的利用和组织 成纤维细胞的细胞骨架元件，从而控制 迁移和收缩。 成纤维细胞介导的 收缩和多孔CG基质结构， 胶原纤维束组织也将在长期的研究 补充有抗坏血酸的培养物。 成纤维细胞程度 多孔CG矩阵的收缩与CG矩阵的结构 将独立变化，以研究他们的单独作用， 胶原纤维束组织。 这将有助于确定 CG矩阵是否改变了新合成的 结缔组织和伤口是否收缩的机械应力 是排列和压缩胶原纤维束的主要因素 植入疤痕组织 CG矩阵对反应性的影响 成纤维细胞的生长因子已知增加胶原蛋白的合成将 也要坚决。 这些是基础研究，将阐明 CG基质抑制收缩的分子机制， 收缩和CG矩阵架构对组织的作用 新形成的组织中的胶原纤维束。 这些研究将 提高对细胞-基质相互作用影响的理解， 正常的伤口愈合事件和结缔组织再生。