A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development, homeostasis, and disease of human intervertebral disks (IVDs) remains challenging. Here, the transcriptomic landscape of 108 108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs, including the nucleus pulposus (NP), annulus fibrosus, and cartilage endplate (CEP). The chondrocyte subclusters were classified based on their potential regulatory, homeostatic, and effector functions in extracellular matrix (ECM) homeostasis. Notably, in the NP, a PROCR⁺ resident progenitor population showed enriched colony-forming unit-fibroblast (CFU-F) activity and trilineage differentiation capacity. Finally, intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-β cascades are important cues in the NP microenvironment. In conclusion, a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.

全面了解人类椎间盘 (IVD) 的发育、稳态和疾病背后的细胞异质性和分子机制仍然具有挑战性。在这里，使用来自年轻和成人健康 IVD 的三个主要隔室的单细胞 RNA 测序绘制了 108 108 个 IVD 细胞的转录组图谱，包括髓核 (NP)、纤维环和软骨终板 (CEP)。软骨细胞亚群根据它们在细胞外基质 (ECM) 稳态中的潜在调节、稳态和效应器功能进行分类。值得注意的是，在 NP 中，一个 PROCR ⁺常驻祖细胞群表现出丰富的集落形成单位-成纤维细胞 (CFU-F) 活性和三系分化能力。最后，基于信号网络分析的细胞间串扰揭示了 PDGF 和 TGF-β 级联是 NP 微环境中的重要线索。总之，解决空间调节的细胞异质性以及作为体内平衡基础的关键信号的单细胞转录组图谱将有助于在临床中建立新的 IVD 变性治疗策略。