Promoting Chronic Wound Healing with Ultrasound and Fibronectin

描述(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损伤。慢性溃疡的原因从持续压力引起的组织血流量减少，到糖尿病等潜在病理导致的全身代谢变化。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中的细胞提供合成的ECM形式的FN来促进慢性伤口的愈合。FN通过严格调控的细胞介导过程被整合到ECM中。ECM FN特别促进细胞增殖、细胞骨架组织和ECM沉积。FN的第一个III型模块(FNIII-1H)中的一个隐蔽的肝素结合位点介导了ECM FN的细胞效应。将FN结合到ECM中和暴露FNIII-1H需要对分子施加细胞和/或组织衍生的力。超声波是一种机械能，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。我们可以与蛋白质四级结构相互作用，并破坏蛋白质四级结构。我假设与US相关的机械力可以通过诱导FNIII-1H的多聚化或暴露的构象变化来‘激活’FN，并且US激活的FN的加入可以促进慢性伤口愈合。我的数据显示，在创伤愈合受损的体外模型中，ECM-FN特异性地促进了细胞的增殖。我的数据还表明，美国可以诱导FN多聚化。这些数据表明，美国激活的ECM形式的FN可以绕过对细胞依赖的FN激活的需要，从而促进慢性伤口的愈合。这项建议的目的是：(1)在创伤愈合受损的体外模型中确定FN对肌成纤维细胞增殖的影响；(2)通过诱导多聚体或暴露FNIII-1H来表征激活FN的声学参数；(3)在创伤愈合受损的体外模型中确定US激活的FN对肌成纤维细胞增殖的影响；以及(4)在创伤愈合受损的小鼠模型中确定US激活的FN对创面闭合率的影响。 公共卫生相关性：慢性皮肤溃疡每年影响约700万人。目前的治疗方法在促进慢性伤口愈合方面的成功有限。该项目的目标是通过为伤口中的细胞提供合成的ECM形式的FN来促进慢性伤口的愈合。

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.