PDF(Pubmed)
Abstract：
Background: Duchenne muscular dystrophy is a genetic disease produced by mutations in the dystrophin gene characterized by early onset muscle weakness leading to severe and irreversible disability. Muscle degeneration involves a complex interplay between multiple cell lineages spatially located within areas of damage, termed the degenerative niche, including inflammatory cells, satellite cells (SCs) and fibro-adipogenic precursor cells (FAPs). FAPs are mesenchymal stem cell which have a pivotal role in muscle homeostasis as they can either promote muscle regeneration or contribute to muscle degeneration by expanding fibrotic and fatty tissue. Although it has been described that FAPs could have a different behavior in DMD patients than in healthy controls, the molecular pathways regulating their function as well as their gene expression profile are unknown. Methods: We used single-cell RNA sequencing (scRNAseq) with 10X Genomics and Illumina technology to elucidate the differences in the transcriptional profile of isolated FAPs from healthy and DMD patients. Results: Gene signatures in FAPs from both groups revealed transcriptional differences. Seurat analysis categorized cell clusters as proliferative FAPs, regulatory FAPs, inflammatory FAPs, and myofibroblasts. Differentially expressed genes (DEGs) between healthy and DMD FAPs included upregulated genes CHI3L1, EFEMP1, MFAP5, and TGFBR2 in DMD. Functional analysis highlighted distinctions in system development, wound healing, and cytoskeletal organization in control FAPs, while extracellular organization, degradation, and collagen degradation were upregulated in DMD FAPs. Validation of DEGs in additional samples (n = 9) using qPCR reinforced the specific impact of pathological settings on FAP heterogeneity, reflecting their distinct contribution to fibro or fatty degeneration in vivo. Conclusion: Using the single-cell RNA seq from human samples provide new opportunities to study cellular coordination to further understand the regulation of muscle homeostasis and degeneration that occurs in muscular dystrophies.
摘要：
背景：Duchenne型肌营养不良是一种由肌营养不良蛋白基因突变产生的遗传性疾病，其特征是早期发作的肌肉无力导致严重和不可逆转的残疾。肌肉退化涉及空间上位于损伤区域内的多个细胞谱系之间的复杂相互作用。被称为退化生态位，包括炎症细胞,卫星细胞（SCs）和纤维脂肪前体细胞（FAP）。FAP是间充质干细胞,其在肌肉稳态中具有关键作用,因为它们可以通过扩张纤维化和脂肪组织来促进肌肉再生或促成肌肉变性。尽管已经描述了FAP在DMD患者中可能具有与健康对照不同的行为，调节其功能的分子途径以及其基因表达谱是未知的。方法：我们使用单细胞RNA测序（scRNAseq）与10X基因组学和Illumina技术来阐明来自健康和DMD患者的分离FAP的转录谱差异。结果:来自两个组的FAP中的基因签名显示转录差异。Seurat分析将细胞簇分类为增殖性FAP，监管FAP，炎性FAP，和肌成纤维细胞。健康和DMDFAP之间的差异表达基因（DEGs）包括DMD中上调的基因CHI3L1，EFEMP1，MFAP5和TGFBR2。功能分析突出了系统开发中的区别，伤口愈合，和对照FAP中的细胞骨架组织，而细胞外组织，降解，DMDFAP中胶原降解上调。使用qPCR验证其他样品（n=9）中的DEGs增强了病理设置对FAP异质性的特定影响，反映了它们对体内纤维或脂肪变性的独特贡献。结论：使用来自人类样品的单细胞RNAseq为研究细胞协调提供了新的机会，以进一步了解肌营养不良中发生的肌肉稳态和变性的调节。
