Deciphering mesenchymal drivers of human Dupuytren’s disease at single-cell level

Dupuytren’s disease (DD) is a common, progressive fibroproliferative disease affecting the palmar fascia of the hands, causing fingers to irreversibly flex towards the palm with significant loss of function. Surgical treatments are limited, therefore effective new therapies for DD are urgently required. To identify key cellular and molecular pathways driving DD we employed single-cell RNA sequencing (scRNA-seq), profiling the transcriptomes of 35,250 human single cells from DD, non-pathogenic fascia, and healthy dermis. We identify a DD-specific population of pathogenic PDPN+/FAP+ mesenchymal cells displaying elevated expression of fibrillar collagens and profibrogenic genes. In silico trajectory analysis reveals resident fibroblasts to be the source of this pathogenic population. To resolve the processes governing DD progression, genes differentially expressed during fibroblast differentiation were identified including upregulated TNFRSF12A and transcription factor SCX. Knockdown of SCX and blockade of TNFRSF12A inhibited proliferation and altered pro-fibrotic gene expression of cultured human FAP+ mesenchymal cells, demonstrating a functional role for these genes in DD. The power of scRNA-seq is utilised to identify the major pathogenic mesenchymal subpopulations driving DD and key molecular pathways regulating the DD-specific myofibroblast phenotype. Using this precision medicine approach, inhibition of TNFRSF12A has shown potential clinical utility in the treatment of Dupuytren’s disease. Single, live cells were isolated from DD tissue, non-pathogenic fascia (from the transverse ligament of the palmar aponeurosis, herein referred to as Skoog’s fascia), and healthy dermis (n=3 DD, n=3 Skoog’s fascia, and n=3 healthy dermis). All tissue was taken at the time of corrective surgery for DD.

杜普伊特伦挛缩症（Dupuytren’s disease, DD）是一种常见的进行性纤维增生性疾病，累及手部掌腱膜，可导致手指不可逆地向掌心屈曲，伴随显著的功能丧失。目前外科治疗手段有限，因此亟需开发针对杜普伊特伦挛缩症的有效新型疗法。为明确驱动该病发生发展的关键细胞与分子通路，本研究采用单细胞RNA测序（single-cell RNA sequencing, scRNA-seq）技术，对来自杜普伊特伦挛缩症病变组织、非致病性腱膜以及健康真皮组织的共35250个人类单细胞进行了转录组谱分析。本研究鉴定出一类杜普伊特伦挛缩症特异性的致病性PDPN+/FAP+间充质细胞群，该细胞群高表达纤维状胶原蛋白及促纤维化基因。计算机模拟（in silico）轨迹分析表明，驻留成纤维细胞是该致病性细胞群的起源。为阐明调控杜普伊特伦挛缩症进展的分子过程，本研究鉴定出成纤维细胞分化过程中差异表达的基因，其中包括上调表达的TNFRSF12A及转录因子SCX。对SCX进行基因敲低以及对TNFRSF12A进行阻断，可抑制培养的人类FAP+间充质细胞的增殖，并改变其促纤维化基因的表达模式，从而证实了这两个基因在杜普伊特伦挛缩症中的功能作用。本研究借助单细胞RNA测序的技术优势，鉴定出驱动杜普伊特伦挛缩症的主要致病性间充质细胞亚群，以及调控该病特异性肌成纤维细胞表型的关键分子通路。基于此精准医学策略，靶向TNFRSF12A的抑制疗法在杜普伊特伦挛缩症的治疗中展现出潜在临床应用价值。研究人员从杜普伊特伦挛缩症病变组织、非致病性腱膜（取自掌腱膜横韧带，本文中称为斯库格筋膜（Skoog’s fascia））以及健康真皮组织中分离出单个活细胞，每组样本量均为3例（杜普伊特伦挛缩症组、斯库格筋膜组、健康真皮组各3例）。所有组织样本均取自杜普伊特伦挛缩症矫正手术过程中。