Department of Applied Physiology and Kinesiology (C.G.P., V.P., J.T., K.K., T.T., Q.Y., T.E.R.), The University of Florida, Gainesville.
Department of Surgery, Division of Vascular Surgery and Endovascular Therapy (B.F., S.T.R., K.A.O., S.T.S., S.A.B.), The University of Florida, Gainesville.
Circ Res. 2023 Oct 27;133(10):791-809. doi: 10.1161/CIRCRESAHA.123.323161. Epub 2023 Oct 12.
Lower extremity peripheral artery disease (PAD) is a growing epidemic with limited effective treatment options. Here, we provide a single-nuclei atlas of PAD limb muscle to facilitate a better understanding of the composition of cells and transcriptional differences that comprise the diseased limb muscle.
We obtained gastrocnemius muscle specimens from 20 patients with PAD and 12 non-PAD controls. Nuclei were isolated and single-nuclei RNA-sequencing was performed. The composition of nuclei was characterized by iterative clustering via principal component analysis, differential expression analysis, and the use of known marker genes. Bioinformatics analysis was performed to determine differences in gene expression between PAD and non-PAD nuclei, as well as subsequent analysis of intercellular signaling networks. Additional histological analyses of muscle specimens accompany the single-nuclei RNA-sequencing atlas.
Single-nuclei RNA-sequencing analysis indicated a fiber type shift with patients with PAD having fewer type I (slow/oxidative) and more type II (fast/glycolytic) myonuclei compared with non-PAD, which was confirmed using immunostaining of muscle specimens. Myonuclei from PAD displayed global upregulation of genes involved in stress response, autophagy, hypoxia, and atrophy. Subclustering of myonuclei also identified populations that were unique to PAD muscle characterized by metabolic dysregulation. PAD muscles also displayed unique transcriptional profiles and increased diversity of transcriptomes in muscle stem cells, regenerating myonuclei, and fibro-adipogenic progenitor cells. Analysis of intercellular communication networks revealed fibro-adipogenic progenitors as a major signaling hub in PAD muscle, as well as deficiencies in angiogenic and bone morphogenetic protein signaling which may contribute to poor limb function in PAD.
This reference single-nuclei RNA-sequencing atlas provides a comprehensive analysis of the cell composition, transcriptional signature, and intercellular communication pathways that are altered in the PAD condition.
下肢外周动脉疾病（PAD）是一种日益流行的疾病，其有效治疗方法有限。在这里，我们提供了 PAD 肢体肌肉的单个核细胞图谱，以促进更好地理解构成病变肢体肌肉的细胞组成和转录差异。
我们从 20 名 PAD 患者和 12 名非 PAD 对照患者中获得了腓肠肌标本。分离核并进行单细胞 RNA 测序。通过主成分分析、差异表达分析和使用已知标记基因对核的组成进行迭代聚类。进行生物信息学分析以确定 PAD 和非 PAD 核之间的基因表达差异，以及随后对细胞间信号网络的分析。单细胞 RNA 测序图谱还伴有肌肉标本的额外组织学分析。
单细胞 RNA 测序分析表明，与非 PAD 相比，PAD 患者的 I 型（慢/氧化）肌核较少，而 II 型（快/糖酵解）肌核较多，这通过肌肉标本的免疫染色得到了证实。PAD 肌核显示出参与应激反应、自噬、缺氧和萎缩的基因的全局上调。肌核的亚聚类还确定了 PAD 肌肉特有的独特群体，其特征是代谢失调。PAD 肌肉还显示出独特的转录谱，并增加了肌肉干细胞、再生肌核和成纤维脂肪祖细胞中转录组的多样性。细胞间通讯网络的分析表明，成纤维脂肪祖细胞是 PAD 肌肉中的主要信号枢纽，以及血管生成和骨形态发生蛋白信号的缺陷，这可能导致 PAD 肢体功能不佳。
这个参考的单细胞 RNA 测序图谱提供了对 PAD 状态下改变的细胞组成、转录特征和细胞间通讯途径的全面分析。
