Promoting Chronic Wound Healing with Ultrasound and Fibronectin

描述（由申请人提供）：慢性皮肤溃疡是由于身体无法愈合而导致的皮肤病变。慢性溃疡的原因包括持续压力导致的组织血流量减少，以及糖尿病等潜在病理导致的代谢系统变化。细胞不能将纤连蛋白（FN）存款到细胞外基质（ECM）中被认为是导致慢性溃疡发病的原因。该项目的目标是通过向伤口中的细胞提供合成ECM形式的FN来促进慢性伤口愈合。FN通过严格调节的细胞介导过程掺入ECM中。ECM FN特异性地增加细胞增殖、细胞骨架组织和ECM沉积。FN的第一个III型模块（FNIII-1H）中隐藏的肝素结合位点介导ECM FN细胞效应。将FN掺入ECM和暴露FNIII-1H需要对分子施加细胞和/或组织衍生的力。超声波是一种可以深入组织传播的机械能。US与大块组织和大分子结构（如细胞和蛋白质）相互作用。US可以与蛋白质四级结构相互作用并破坏蛋白质四级结构。我推测，与US相关的机械力可用于通过诱导导致多聚化或暴露FNIII-1 H的构象变化来“激活”FN，并且加入US激活的FN可促进慢性伤口愈合。我的数据显示，ECM-FN在创伤愈合受损的体外模型中特异性地增加细胞增殖。我的数据还表明，US可以诱导FN多聚化。这些数据表明，US活化的ECM形式的FN可以通过绕过对FN的细胞依赖性活化的需要来促进慢性伤口愈合。该提议的目的是：（1）确定FN对损伤伤口愈合的体外模型中的肌成纤维细胞增殖的影响;（2）表征通过诱导多聚化或暴露FNIII-1H“激活”FN的声学参数;（3）确定US激活的FN对损伤伤口愈合的体外模型中的肌成纤维细胞增殖的影响;和（4）确定US活化的FN对创伤愈合受损的小鼠模型中的创伤闭合速率的影响。 公共卫生相关性：慢性皮肤溃疡每年影响约700万人。目前的疗法在促进慢性伤口愈合方面取得的成功有限。该项目的目标是通过向伤口中的细胞提供合成ECM形式的FN来促进慢性伤口愈合。

DESCRIPTION (provided by applicant): Chronic cutaneous ulcers are lesions on the skin that result from the body's inability to heal. The causes of chronic ulcers range from decreased blood flow to tissues stemming from persistent pressure, to systemic changes in metabolism that result from underlying pathologies such as diabetes. The inability of cells to deposit fibronectin (FN) into the extracellular matrix (ECM) is thought to contribute to the pathogenesis of chronic ulcers. The goal of this project is to promote chronic wound healing by providing cells in the wound with a synthetic ECM form of FN. FN is incorporated into the ECM via a tightly regulated cell-mediated process. ECM FN specifically increases cell proliferation, cytoskeletal organization, and ECM deposition. A cryptic heparin-binding site in FN's first type III module (FNIII-1H) mediates ECM FN cellular effects. Incorporation of FN into the ECM and exposure of FNIII-1H require exertion of cell-and/or tissue-derived forces on the molecule. Ultrasound is a form of mechanical energy that can propagate deep into tissues. US interacts with bulk tissues and macromolecular structures such as cells and proteins. US can interact with, and disrupt, protein quaternary structures. I hypothesize that mechanical forces associated with US can be used to 'activate' FN by inducing conformational changes that result in multimerization or the exposure of FNIII-1 H, and that addition of US-activated FN can promote chronic wound healing. My data show that ECM-FN specifically increases cell proliferation in an in vitro model of impaired wound healing. My data also suggest that US can induce FN multimerization. These data suggest that an US- activated ECM form of FN could promote chronic wound healing by bypassing the need for cell-dependent activation of FN. The aims of this proposal are: (1) Determine the effects of FN on the proliferation of myofibroblasts in an in vitro model of impaired wound healing; (2) Characterize the acoustic parameters that 'activate' FN by inducing multimerization or exposing FNIII-1 H; (3) Determine the effects of US-activated FN on the proliferation of myofibroblasts in an in vitro model of impaired wound healing; and (4) Determine the effects of US-activated FN on the rate of wound closure in a mouse model of impaired wound healing. PUBLIC HEALTH RELEVANCE: Chronic cutaneous ulcers affect approximately 7 million people per year. Current therapies have had limited success in promoting chronic wound healing. The goal of this project is to promote chronic wound healing by providing cells in the wound with a synthetic ECM form of FN.