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

7.项目摘要/摘要 成年人的皮肤通过形成纤维性疤痕组织来愈合，这可能会导致毁灭性的毁容、生长 限制和永久性功能丧失。尽管有太多的临床选择，但目前还没有治疗策略 成功地阻止或逆转这种纤维化过程，疤痕及其后遗症使美国付出了 每年200亿美元。新疗法的开发进展受到了严重阻碍 对导致瘢痕形成的细胞群体及其分子动力学缺乏了解。研究项目： 近年来有报道称，伤口中的脂肪细胞能够转化为成纤维细胞(和 反之亦然；然而，脂肪细胞向成纤维细胞的转变在多大程度上有助于伤口纤维化(疤痕形成)， 而这一过程是否能有针对性地防止疤痕形成，目前尚不清楚。在这项提案中，我们探索了 组织力学首次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，利用遗传谱系追踪，我们将使用组织学、免疫组织化学和 流式细胞术研究脂肪细胞向成纤维细胞的转化及探讨脂肪细胞的分子表型 伤口内的血统来源成纤维细胞。其次，我们将使用彩虹小鼠模型来审问克隆 伤口中脂肪细胞向成纤维细胞转变的动力学，并将应用整合的多组学分析， 单细胞转录(scRNA-seq)和表观基因组(scATAC-seq)、空间转录(Viitum)和 蛋白质组(CODEX)和定量细胞外基质(ECM)超微结构分析，以便稳健地 明确在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有力地支持了脂肪细胞到成纤维细胞的机械转导机制 在伤口愈合过程中的过渡，我们将使用小分子和 转基因方法，以阻止脂肪细胞向成纤维细胞的转变。我们将应用类似的多体模型 分析在完整的背景下区分伤口脂肪细胞动力学的分子动力学 与被阻断的机械信号进行比较，并确定如何抑制机械驱动的脂肪细胞转化为成纤维细胞 转化可能会减少纤维化并产生伤口再生。我们的最终翻译目标是开发 针对纤维化创面细胞动力学以促进再生愈合的治疗。总体而言， 拟议的工作将显著增强我们对关键的分子和细胞决定因素的理解 皮肤疤痕，告知新的抗疤痕疗法的发展，并阐明其贡献 从脂肪组织到伤口纤维化。

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.