Late-onset Pompe disease (LOPD) is a rare genetic disorder caused by the deficiency of acid alpha-glucosidase leading to progressive cellular dysfunction owing to the accumulation of glycogen in the lysosome. The mechanism of relentless muscle damage (a classic manifestation of the disease) has been studied extensively by analysing the whole-muscle tissue; however, little, if anything, is known about transcriptional heterogeneity among nuclei within the multinucleated skeletal muscle cells. This is the first report of application of single-nucleus RNA sequencing to uncover changes in the gene expression profile in muscle biopsies from eight patients with LOPD and four muscle samples from age- and sex-matched healthy controls. We matched these changes with histological findings using GeoMx spatial transcriptomics to compare the transcriptome of control myofibres from healthy individuals with non-vacuolated (histologically unaffected) and vacuolated (histologically affected) myofibres of LODP patients. We observed an increase in the proportion of slow and regenerative muscle fibres and macrophages in LOPD muscles. The expression of the genes involved in glycolysis was reduced, whereas the expression of the genes involved in the metabolism of lipids and amino acids was increased in non-vacuolated fibres, indicating early metabolic abnormalities. Additionally, we detected upregulation of autophagy genes and downregulation of the genes involved in ribosomal and mitochondrial function leading to defective oxidative phosphorylation. Upregulation of genes associated with inflammation, apoptosis and muscle regeneration was observed only in vacuolated fibres. Notably, enzyme replacement therapy (the only available therapy for the disease) showed a tendency to restore dysregulated metabolism, particularly within slow fibres. A combination of single-nucleus RNA sequencing and spatial transcriptomics revealed the landscape of the normal and diseased muscle and highlighted the early abnormalities associated with disease progression. Thus, the application of these two new cutting-edge technologies provided insight into the molecular pathophysiology of muscle damage in LOPD and identified potential avenues for therapeutic intervention.

中文翻译：

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解码晚发性庞贝病患者的肌肉转录组可揭示疾病进展的标志物


迟发型庞贝病 （LOPD） 是一种罕见的遗传性疾病，由酸性 α-葡萄糖苷酶缺乏引起，由于糖原在溶酶体中的积累导致进行性细胞功能障碍。通过分析整个肌肉组织，已经对无情肌肉损伤的机制（该疾病的典型表现）进行了广泛的研究;然而，关于多核骨骼肌细胞内细胞核之间的转录异质性知之甚少（如果有的话）。这是应用单核 RNA 测序揭示 8 名 LOPD 患者和 4 名来自年龄和性别匹配的健康对照的肌肉样本的肌肉活检中基因表达谱变化的首次报告。我们使用 GeoMx 空间转录组学将这些变化与组织学结果相匹配，以比较 LODP 患者非空泡 （组织学未受影响） 和空泡 （组织学受影响） 肌纤维的健康个体的对照肌纤维的转录组。我们观察到 LOPD 肌肉中缓慢和可再生的肌肉纤维和巨噬细胞的比例增加。参与糖酵解的基因表达降低，而参与脂质和氨基酸代谢的基因在非空泡纤维中的表达增加，表明早期代谢异常。此外，我们检测到自噬基因的上调和参与核糖体和线粒体功能的基因下调，导致氧化磷酸化缺陷。仅在空泡纤维中观察到与炎症、细胞凋亡和肌肉再生相关的基因上调。 值得注意的是，酶替代疗法（该疾病唯一可用的疗法）显示出恢复代谢失调的趋势，尤其是在慢纤维中。单核 RNA 测序和空间转录组学的结合揭示了正常和患病肌肉的景观，并突出了与疾病进展相关的早期异常。因此，这两项新前沿技术的应用提供了对 LOPD 中肌肉损伤的分子病理生理学的见解，并确定了治疗干预的潜在途径。