Skin microbial-based mechanisms of accelerated wound healing

项目总结 对于未愈合的伤口，需要改进治疗方法，因为它们是主要的 增加治疗费用以及发病率和死亡率，从而对医疗系统构成挑战。 皮肤微生物群存在于所有皮肤伤口的界面上，但它作为一种新的治疗方法的潜力 目标仍未被攻破。因此，我们的长期目标是了解宿主-微生物在 因此，我们可以利用这些机制来确定伤口愈合的治疗方法。要发起这一行动 调查中，我们实验室先前对非感染的伤口样本进行了基因组学分析。 糖尿病足部溃疡(DFU)，并发现了一种令人惊讶的普遍存在的伤口居民粪产碱菌。非常 在创伤的背景下，人们对这种物种知之甚少，所以我们试图调查粪便假单胞菌的作用。 关于伤口愈合的。我们观察到一个令人惊讶的发现，用粪便曲霉处理伤口会加速这种速度。 促进体内伤口愈合，并激活角质形成细胞的上皮化表型。因此，中心目标是 本研究的目的是确定粪链霉菌介导伤口加速愈合的机制。支持- 炎症细胞因子信号是促进再上皮化所必需的，尤其是IL-6。 显示在愈合过程中诱导角质形成细胞的激活。因此，我测试了粪假单胞菌是否诱导了一种细胞因子 在角质形成细胞中的反应，并发现强劲的IL-6产生后，粪便曲霉条件培养液处理。 细菌调节寄主反应的主要机制是通过产生分泌物 分子。我发现，粪肠弯曲菌无菌上清液，而不是细菌细胞表面分子，促进了 角质形成细胞迁移和IL-6的产生。综上所述，这些发现导致了我的假设，即粪肠弯曲杆菌 产生分泌的分子，通过增强角质形成细胞IL-6信号来促进再上皮化。目标1 将通过组合确定粪便曲霉诱导加速愈合的宿主机制 伤口愈合分析和转录图谱。目的2将鉴定A. 粪便是产生促进愈合的分泌分子所必需的。我将使用比较基因组学方法来 确定与促进伤口愈合表型分离的基因组基因座。为了实现这一目标，我将利用 我们收集了44株粪肠弯曲杆菌临床分离株，并进行了基因组多重比对。我要配这双。 使用伤口愈合分析进行表型筛选以确定哪个基因组位点的遗传筛查 与促进愈合的表型分离。 与这些实验目标相结合，我还将在 在医学博士项目和我的博士导师的指导下，我在宾夕法尼亚大学学习。这项培训计划 将通过以下目标促进我作为未来内科科学家的发展：加强 独立成为一名研究人员，开发计算和湿法实验室技术，扩大在 微生物群和伤口愈合领域，改善科学交流，并从事指导工作。

PROJECT SUMMARY Improved therapeutic approaches are needed for non-healing wounds, as they present a major challenge to the healthcare system by increasing treatment costs as well as rates of morbidity and mortality. The skin microbiome exists at the interface of all cutaneous wounds, but its potential as a novel therapeutic target remains untapped. Therefore, our long-term goal is to understand host-microbial interactions during wound healing, so we may leverage these mechanisms to identify wound healing treatments. To initiate this investigation, our lab previously performed a metagenomic analysis on wound samples from non-infected diabetic foot ulcers (DFUs) and unearthed a surprisingly prevalent wound inhabitant Alcaligenes faecalis. Very little is known about this species in the context of wounds, so we sought to investigate the effect of A. faecalis on wound healing. We observed the surprising finding that treating wounds with A. faecalis accelerates the rate of wound healing in vivo and activates a pro-epithelialization phenotype in keratinocytes. Thus, the central goal of this study is to identify the mechanism by which A. faecalis mediates accelerated wound healing. Pro- inflammatory cytokine signaling is necessary to promote re-epithelialization, and IL-6 in particular has been shown to induce activation of keratinocytes during healing. Therefore, I tested if A. faecalis induced a cytokine response in keratinocytes and found robust IL-6 production after treatment with A. faecalis conditioned media. A primary mechanism by which bacteria can modulate host responses is through production of secreted molecules. I found that sterile supernatant of A. faecalis, rather than bacterial-cell surface molecules, promotes keratinocyte migration and IL-6 production. Together, these findings lead to my hypothesis that A. faecalis produces secreted molecules that improve re-epithelialization by enhancing keratinocyte IL-6 signaling. Aim 1 will determine the host mechanisms of A. faecalis-induced accelerated healing through a combination of wound healing assays and transcriptional profiling. Aim 2 will identify the microbial genetic determinants of A. faecalis necessary to produce the pro-healing secreted molecule. I will use comparative genomics approach to identify genomic loci that segregate with a pro-wound healing phenotype. To complete this aim, I will leverage our collection of 44 A. faecalis clinical DFU isolates and perform a genomic multiple alignment. I will pair this genetic screen with a phenotypic screen using wound healing assays to determine which genomic locus segregates with the pro-healing phenotype. In conjunction with these experimental aims, I will also engage in a rigorous training plan at the University of Pennsylvania under the guidance of the MD/PhD Program and my PhD advisor. This training plan will foster my development as a future physician scientist through the following goals: strengthen independence as an investigator, develop computational and wet lab techniques, expand knowledge in the microbiome and wound healing fields, improve scientific communication, and engage in mentorship.