Exosomes in Wound Healing

摘要 起源于手术或创伤的伤口，如果持续存在，就是一个主要的医疗负担。其中一个 无法愈合的慢性糖尿病(D)伤口的常见并发症是停滞的炎症。 因此，调节这种脱轨免疫反应的机制非常有意义。 这一建议是基于我们新的观察结果，伤口边缘组织的角质形成细胞(K) 通过携带遗传信息的K始发外体与来访的巨噬细胞进行串话 以高度有组织和定向的方式向巨噬细胞(免疫细胞)传递。Exosome可能是 被视为生物纳米载体，由活细胞释放，并与许多 包括脓毒症在内的炎症状况。基因中的外显子选择它们进行外切体 包装。我们认为miR-21是一种这样的非编码基因，其前体是Pre-R-21。 MIR-21被包装在K起源的外切体中，并被输送到伤口的巨噬细胞中分解 及时发炎。这个串扰过程在D中被破坏了。我们观察到 外切体的表面蛋白质化学，即甘露糖的存在，将其作为目标输送到 伤口巨噬细胞。D修饰这种表面蛋白质化学，从而产生甘露糖 影响伤口巨噬细胞摄取这些外切体的修饰。要添加 拟开展的研究工作的临床意义我们寻求研究外切体表面甘露糖 与慢性非D患者相比，控制较差、控制良好的D患者的改良率 伤口。因此，提出了以下三个具体目标：目标1：确定K- D创口边缘组织中巨噬细胞串扰受到影响。1.1钾的摄取 创伤部位巨噬细胞的外切体(Wmφ)在D.1.2的条件下受到损害 D创伤中受损的K-巨噬细胞串扰导致分辨率下降 发炎。目的2：检测K来源的外切体的表面糖蛋白是否来自 在D损害巨噬细胞靶向的条件下，伤口部位糖基化。2.1伤口- EDGE K衍生的外切体(κ-GFPEXO)在D。 2.伤口处κ-GFPEXO表面的甘露糖在D条件下糖化。 从而使巨噬细胞靶向性受损。目的3：分离D型和非D型人的外切体 慢性创面液表征胞外体亚群及其表面甘露糖修饰。 这项由早期研究人员提出的建议旨在为实验室奠定基础。 这将致力于研究外科和创伤性损伤的胞外机制。 并进行修复。这样的努力很可能有助于我们对 伤口修复和提供新的治疗方法。

ABSTRACT Wounds, surgical or trauma in origin, is a major healthcare burden when it persists. One of the common complications of non-healing chronic diabetic (D) wounds is stalled inflammation. Mechanisms regulating such derailed immune response is therefore of extraordinary interest. This proposal rests on our novel observation that keratinocytes (K) of the wound-edge tissue cross-talk with visiting macrophages via K-originating exosomes which carry genetic information to macrophages (immune cells) in a highly organized and directed manner. Exosomes may be viewed as biology nanocarriers, released by live cells, and have been implicated in numerous inflammatory conditions including sepsis. Exomotif in genes select them for exosomal packaging. We propose that miR-21 is one such non-coding gene the precursor of which, pre- miR-21, is packaged in K-originating exosomes and delivered to wound macrophages to resolve inflammation in a timely manner. This process of cross-talk is compromised in D. We observed that surface protein chemistry of exosomes, i.e. presence of mannose, targets it for delivery to wound macrophages. D modifies this surface protein chemistry resulting in mannose modifications which compromises uptake of these exosomes by wound macrophages. To add clinical significance to the proposed work we seek to study exosome surface mannose modifications in poorly controlled, well controlled D compared to non-D patients with chronic wounds. The following three specific aims are thus proposed: Aim 1: Determine whether K- macrophage cross-talk is compromised in D wound-edge tissue. 1.1 Uptake of K-originating exosomes by wound-site macrophages (wmφ) is compromised under conditions of D. 1.2 Compromised K-macrophage cross-talk in D wound causes impairment in resolution of inflammation. Aim 2: Test whether surface glycoproteins of K-derived exosomes from the wound-site are glycosylated under conditions of D impairing macrophage targeting. 2.1 Wound- edge K-derived exosomes (κ-GFPEXO) undergoes mannose isomerization under conditions of D. 2.2 Mannose on the surface of κ-GFPEXO at the wound-site is glycated under conditions of D such that macrophage targeting is impaired. Aim 3: Isolate exosomes from D and non-D human chronic wound fluid to characterize exosomal subsets and their surface mannose modifications. This proposal from an early stage investigator is aimed at laying the foundation of a laboratory that would be dedicated to the study of exosomal mechanisms in surgical and traumatic injury and repair. Such efforts are likely to contribute to seminal advances in our understanding of wound repair and inform novel therapies.