Skin microbial-based mechanisms of accelerated wound healing

基于皮肤微生物的加速伤口愈合机制

基本信息

批准号：
10652363
负责人：
Ellen White
金额：
$ 3.51万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10652363
关键词：
Acceleration Affect Aftercare Alcaligenes Amputation Bacteria Biochemical Biological Assay Biology Cell surface Cells Chronic Clinical Collection Communication Communities Cytokine Signaling Development Diabetic Foot Ulcer Doctor of Philosophy Enterococcus faecalis Epithelium Failure Fostering Future Gene Expression Gene Expression Profiling Genetic Determinism Genetic Screening Genomic Segment Genomic approach Genomics Goals Health Care Costs Healthcare Systems Immune response Impaired healing In Vitro Inflammatory Interleukin-6 Investigation Knowledge Lead Mediating Mentorship Metagenomics Microbial Genetics Morbidity - disease rate Mus Necrosis Osteomyelitis Outcome Pathway interactions Pennsylvania Phenotype Physicians Play Production Proliferating Research Research Personnel Role Sampling Scientist Series Signal Transduction Skin Specimen Staphylococcus aureus Sterility Techniques Testing Therapeutic Training Treatment Cost Universities Variant Work adverse outcome cell behavior chronic wound commensal bacteria comparative genomics cytokine diabetic ulcer experimental study genomic locus healing host-microbe interactions improved in vivo keratinocyte microbial microbial community microbial products microbiome microbiota migration mortality mouse model new therapeutic target non-healing wounds novel pathogenic microbe programs response segregation skin microbiome skin wound therapeutic target tissue repair transcriptome transcriptome sequencing transcriptomics virtual wound wound healing wound response wound treatment

项目摘要

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.

项目概要对于不愈合的伤口需要改进的治疗方法，因为它们是主要的治疗费用以及发病率和死亡率的增加给医疗保健系统带来了挑战。皮肤微生物组存在于所有皮肤伤口的界面处，但其作为一种新型治疗方法的潜力目标尚未开发。因此，我们的长期目标是了解宿主与微生物之间的相互作用伤口愈合，因此我们可以利用这些机制来确定伤口愈合治疗方法。为了发起这个调查中，我们的实验室之前对未感染的伤口样本进行了宏基因组分析糖尿病足溃疡 (DFU) 并发现了一种令人惊讶地普遍的伤口居民粪产碱菌 (Alcaligenes faecalis)。非常我们对这个物种在伤口方面知之甚少，因此我们试图研究粪曲霉的影响关于伤口愈合。我们观察到了一个令人惊讶的发现：用粪曲霉治疗伤口可以加速伤口愈合的速度体内伤口愈合并激活角质形成细胞中的促上皮化表型。因此，中心目标本研究的目的是确定粪曲霉介导加速伤口愈合的机制。亲- 炎症细胞因子信号转导对于促进上皮再形成是必要的，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，我测试了粪曲霉是否诱导了细胞因子角质形成细胞中的反应，并发现用粪曲霉条件培养基处理后，IL-6 产生强劲。细菌调节宿主反应的主要机制是通过产生分泌的分子。我发现粪曲霉的无菌上清液，而不是细菌细胞表面分子，促进角质形成细胞迁移和 IL-6 产生。总之，这些发现得出了我的假设：粪曲霉产生分泌分子，通过增强角质形成细胞 IL-6 信号传导来改善上皮细胞再形成。目标1 将通过以下组合确定粪曲霉诱导加速愈合的宿主机制伤口愈合测定和转录分析。目标 2 将确定 A 的微生物遗传决定因素。粪肠球菌是产生促愈合分泌分子所必需的。我将使用比较基因组学方法识别与促进伤口愈合表型分离的基因组位点。为了完成这个目标，我将利用我们收集了 44 个粪曲霉临床 DFU 分离株，并进行了基因组多重比对。我会把这个配对使用伤口愈合测定进行表型筛选的遗传筛选，以确定哪个基因组位点与促愈合表型分离。结合这些实验目标，我还将在实验室进行严格的训练计划。宾夕法尼亚大学在MD/PhD项目和我的博士导师的指导下。本次培训计划将通过以下目标促进我作为未来医师科学家的发展：作为研究者的独立性，开发计算和湿实验室技术，扩展相关领域的知识微生物组和伤口愈合领域，改善科学交流，并参与指导。