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。慢性溃疡的原因有多种，从持续压力引起的组织血流量减少，到糖尿病等潜在病理引起的代谢系统改变。细胞不能将纤维连接蛋白（FN）沉积到细胞外基质（ECM）中被认为是慢性溃疡的发病机制之一。该项目的目标是通过为伤口细胞提供合成ECM形式的FN来促进慢性伤口愈合。FN通过严格调控的细胞介导过程被纳入ECM。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）中的一个隐肝素结合位点介导ECM FN细胞效应。将FN并入ECM和暴露于FNIII-1H需要对分子施加细胞和/或组织来源的力。超声波是机械能的一种形式，可以传播到组织深处。US与大块组织和大分子结构（如细胞和蛋白质）相互作用。US可以与蛋白质的四级结构相互作用并破坏它们。我假设与US相关的机械力可以通过诱导构象变化来“激活”FN，从而导致多聚化或暴露于fniii - 1h，并且US激活的FN的添加可以促进慢性伤口愈合。我的数据显示，在体外创伤愈合受损模型中，ECM-FN特异性地增加了细胞增殖。我的数据也表明美国可以诱导FN多元化。这些数据表明，US激活的ECM形式的FN可以通过绕过细胞依赖的FN激活来促进慢性伤口愈合。本提案的目的是：(1)在体外创伤愈合受损模型中确定FN对肌成纤维细胞增殖的影响；(2)表征通过诱导多聚或暴露FNIII-1 H来“激活”FN的声学参数；(3)在体外创面愈合受损模型中，确定us活化FN对肌成纤维细胞增殖的影响；(4)测定us激活的FN对创伤愈合受损小鼠模型伤口愈合速度的影响。

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.