Spatiotemporal characterization of human early intervertebral disc formation at single-cell resolution

Intervertebral disc (IVD) performs as a fibrocartilaginous joint to anchor adjacent vertebrae (VB) and is essential for the mechanical stabilization of axial skeleton. Although several studies have demonstrated the cellular heterogeneity of adult mature IVD, a single-cell transcriptomic atlas mapping early IVD formation is still lacking. Here, we generated the first spatiotemporal and single-cell based transcriptomic atlas of human IVD formation at embryonic stage, as well as a comparative mouse transcript landscape. The notochord (NC)/nucleus pulposus (NP) cells, vertebral chondrocytes, and annulus fibrosus (AF) cells were characterized. Our single-cell transcriptomic atlas that resolves spatiotemporally regulated cellular heterogeneity underlying early IVD development will be leveraged to develop preventative and regenerative strategies for IVD degeneration. Three embryonic mouse axial skeleton at E11.5-13.5 were cryosectioned to a thickness of 10 m, followed by spatial transcriptome analysis via 10x Genomics Visium.椎间盘（Intervertebral Disc, IVD）是一类纤维软骨连结，用于锚定相邻椎体（Vertebrae, VB），对维持中轴骨骼的力学稳定至关重要。尽管已有多项研究证实了成熟成人椎间盘的细胞异质性，但目前仍缺乏可用于描绘椎间盘早期形成过程的单细胞转录组图谱。本研究首次构建了人类胚胎阶段椎间盘发育过程的时空单细胞转录组图谱，并同步生成了小鼠的对比转录组数据集。研究对脊索（Notochord, NC）/髓核（Nucleus Pulposus, NP）细胞、椎体软骨细胞及纤维环（Annulus Fibrosus, AF）细胞完成了特征鉴定。本研究所解析的、调控椎间盘早期发育的时空特异性细胞异质性单细胞转录组图谱，将为椎间盘退变的预防与再生修复策略开发提供重要支撑。我们对3份E11.5-13.5阶段的小鼠胚胎中轴骨骼样本进行冰冻切片，切片厚度为10 μm，随后通过10x Genomics Visium平台开展空间转录组分析。