Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Sci Transl Med. 2023 Oct 25;15(719):eadg5252. doi: 10.1126/scitranslmed.adg5252.
Effective tissue repair requires coordinated intercellular communication to sense damage, remodel the tissue, and restore function. Here, we dissected the healing response in the intestinal mucosa by mapping intercellular communication at single-cell resolution and integrating with spatial transcriptomics. We demonstrated that a risk variant for Crohn's disease, hepatocyte growth factor activator (HGFAC) ArgHis (R509H), disrupted a damage-sensing pathway connecting the coagulation cascade to growth factors that drive the differentiation of wound-associated epithelial (WAE) cells and production of a localized retinoic acid (RA) gradient to promote fibroblast-mediated tissue remodeling. Specifically, we showed that HGFAC R509H was activated by thrombin protease activity but exhibited impaired proteolytic activation of the growth factor macrophage-stimulating protein (MSP). In R509H mice, reduced MSP activation in response to wounding of the colon resulted in impaired WAE cell induction and delayed healing. Through integration of single-cell transcriptomics and spatial transcriptomics, we demonstrated that WAE cells generated RA in a spatially restricted region of the wound site and that mucosal fibroblasts responded to this signal by producing extracellular matrix and growth factors. We further dissected this WAE cell-fibroblast signaling circuit in vitro using a genetically tractable organoid coculture model. Collectively, these studies exploited a genetic perturbation associated with human disease to disrupt a fundamental biological process and then reconstructed a spatially resolved mechanistic model of tissue healing.
有效的组织修复需要协调的细胞间通讯来感知损伤、重塑组织并恢复功能。在这里，我们通过在单细胞分辨率下绘制细胞间通讯并与空间转录组学相结合，剖析了肠道黏膜的愈合反应。我们证明，克罗恩病的风险变体，肝细胞生长因子激活物（HGFAC）ArgHis（R509H），破坏了连接凝血级联反应与生长因子的损伤感应途径，这些生长因子驱动与伤口相关的上皮（WAE）细胞分化，并产生局部视黄酸（RA）梯度，以促进成纤维细胞介导的组织重塑。具体来说，我们表明，HGFAC R509H 被凝血酶蛋白酶活性激活，但表现出生长因子巨噬细胞刺激蛋白（MSP）的蛋白水解激活受损。在 R509H 小鼠中，结肠损伤后 MSP 激活减少导致 WAE 细胞诱导受损和愈合延迟。通过单细胞转录组学和空间转录组学的整合，我们证明了 WAE 细胞在伤口部位的一个空间受限区域产生 RA，而黏膜成纤维细胞通过产生细胞外基质和生长因子来响应该信号。我们进一步在体外使用可遗传操纵的类器官共培养模型剖析了这个 WAE 细胞-成纤维细胞信号通路。总之，这些研究利用与人类疾病相关的遗传扰动来破坏基本的生物学过程，然后构建了组织愈合的空间分辨机制模型。
