Defining the role of mechanoresponsive adipocyte-to-fibroblast transition in wound fibrosis.

7.项目总结/摘要 成人皮肤愈合发展纤维化疤痕组织，这可能会导致毁灭性的毁容，增长 限制和永久性功能丧失。尽管有过多的临床选择，但目前没有治疗策略 成功地预防或逆转这种纤维化过程，疤痕及其后遗症花费了美国超过 每年200亿美元新疗法的开发进展受到了 缺乏对瘢痕形成的细胞群及其分子动力学的了解。研究 近年来已经报道了伤口中的脂肪细胞能够转变成成纤维细胞（反之亦然 反之亦然）;然而，脂肪细胞到成纤维细胞的转变促成伤口纤维化（瘢痕形成）的程度， 以及这一过程是否可以有针对性地防止疤痕形成，仍然是未知的。在本提案中，我们探讨 第一次发现了组织力学在真皮脂肪细胞转化为瘢痕成纤维细胞中的作用， 伤口环境首先，采用遗传谱系追踪，我们将使用组织学，免疫组织化学， 流式细胞术研究脂肪细胞向成纤维细胞的转化并询问脂肪细胞的分子表型 伤口内的谱系来源的成纤维细胞。第二，我们将使用Rainbow小鼠模型来询问克隆的 伤口中脂肪细胞向成纤维细胞转化的动力学，并将应用综合多组学分析， 单细胞转录组学（scRNA-seq）和表观基因组学（scATAC-seq）、空间转录组学（Visium）和 蛋白质组学（CODEX）和定量细胞外基质（ECM）超微结构分析，以稳健地 定义瘢痕形成过程中脂肪细胞向成纤维细胞转化的分子驱动因素和途径。第三、 因为我们的初步数据强烈支持脂肪细胞到成纤维细胞的机械转导机制 在伤口愈合过程中，我们将使用小分子和 转基因方法以阻断脂肪细胞向成纤维细胞的转变。我们将采用类似的多组学 分析，以阐明在完整的环境中区分伤口脂肪细胞动力学的分子动力学。 与阻断的机械信号传导，并确定如何抑制机械驱动的脂肪细胞成纤维细胞 转化可以减少纤维化并产生伤口再生。我们的最终目标是发展 靶向纤维化伤口细胞动力学以促进再生愈合的治疗剂。统称 拟议的工作将大大提高我们的理解的关键分子和细胞的决定因素， 皮肤瘢痕形成，告知新的抗瘢痕形成疗法的发展，并阐明了 伤口纤维化。

7. Project Summary/Abstract Adult human skin heals by developing fibrotic scar tissue, which can result in devastating disfigurement, growth restriction, and permanent functional loss. Despite a plethora of clinical options, no current treatment strategies successfully prevent or reverse this fibrotic process, and scars and their sequelae cost the United States over $20 billion every year. Progress towards the development of new therapies has been significantly hindered by a lack of understanding of the cell populations responsible for scarring and their molecular dynamics. Studies in recent years have reported that adipocytes in wounds are capable of transitioning into fibroblasts (and vice versa); however, the extent to which adipocyte-to-fibroblast transition contributes to wound fibrosis (scarring), and whether this process can be targeted to prevent scarring, remain unknown. In this proposal, we explore for the first time the role of tissue mechanics in conversion of dermal adipocytes to scarring fibroblasts within the wound environment. First, employing genetic lineage tracing, we will use histology, immunohistochemistry, and flow cytometry to study adipocyte-to-fibroblast transition and to interrogate the molecular phenotype of adipocyte lineage-derived fibroblasts within wounds. Second, we will use a Rainbow mouse model to interrogate clonal dynamics of adipocyte-to-fibroblast transition in wounds, and will apply an integrated multi-omic analysis, with single-cell transcriptomic (scRNA-seq) and epigenomic (scATAC-seq), spatial transcriptomic (Visium) and proteomic (CODEX), and quantitative extracellular matrix (ECM) ultrastructural analyses, in order to robustly define the molecular drivers and pathways involved in adipocyte-to-fibroblast conversion during scarring. Third, as our preliminary data strongly support a mechanotransduction mechanism underlying adipocyte-to-fibroblast transition during wound healing, we will inhibit mechanical signaling in adipocytes using both small molecule and transgenic approaches in order to block adipocyte-to-fibroblast transition. We will apply a similar multi-omic analysis to elucidate the molecular dynamics that differentiate wound adipocyte dynamics in the context of intact versus blocked mechanical signaling and determine how inhibiting mechanically driven adipocyte-to-fibroblast conversion may reduce fibrosis and yield wound regeneration. Our ultimate translational goal is to develop therapeutics that target fibrogenic wound cell dynamics to promote regenerative healing. Collectively, the proposed work will significantly enhance our understanding of the key molecular and cellular determinants of cutaneous scarring, inform the development of novel anti-scarring therapies, and shed light on the contributions of adipose tissue to wound fibrosis.