METHODS: We performed bioinformatics analysis using our previously published findings to construct single cell expression profiles of normal and degenerated nucleus pulposus. Then, in-depth differential analysis was used to characterize the expression of Wnt/Ca2+ signaling pathway between normal and degenerated nucleus pulposus cells in humans.
RESULTS: The obtained cell data were clustered into five different chondrocytes clusters, which chondrocyte 4 and chondrocyte 5 mainly accounted for a high proportion in degenerated nucleus pulposus tissues, but rarely in normal nucleus pulposus tissues. Genes associated within the Wnt/Ca2+ signaling pathway, such as Wnt5B, FZD1, PLC (PLCB1), CaN (PPP3CA) and NAFATC1 are mainly present in chondrocyte 3, chondrocyte 4 and chondrocyte 5 from degenerated nucleus pulposus tissues. In addition, as a receptor that activates Wnt signaling pathway, LRP5 is mainly highly expressed in chondrocyte 5 of degenerated nucleus pulposus cells. Six genes, ANGPTL4, PTGES, IGFBP3, GDF15, TRIB3 and TNFRSF10B, which are associated with apoptosis and inflammatory responses, and are widespread in chondrocyte 4 and chondrocyte 5, may be closely related to degenerative of nucleus pulposus cells.
CONCLUSIONS: Single-cell RNA sequencing revealed differential expression of Wnt/Ca2+ signaling in human normal and degenerated nucleus pulposus cells, and this differential expression may be closely related to the abundance of chondrocyte 4 and chondrocyte 5 in degenerated nucleus pulposus cells. In degenerated nucleus pulposus cells, LRP5 activate Wnt5B, which promotes nucleus pulposus cell apoptosis and inflammatory response by regulating the Wnt/Ca2+ signaling pathway, thereby promoting disc degeneration. ANGPTL4, IGFBP3, PTGES in chondrocyte 4 and TRIB3, GDF15, TNFRSF10B in chondrocyte 5 may play an important role in this process.
方法:我们使用先前发表的发现进行了生物信息学分析,以构建正常和变性髓核的单细胞表达谱。然后,使用深入的差异分析来表征人类正常和变性髓核细胞之间Wnt/Ca2信号通路的表达。
结果:将获得的细胞数据分为五个不同的软骨细胞簇,其中软骨细胞4和软骨细胞5在退变的髓核组织中占很高的比例,但很少在正常的髓核组织。Wnt/Ca2+信号通路内相关基因,比如WNT5B,FZD1,PLC(PLCB1),CaN(PPP3CA)和NAFATC1主要存在于来自变性髓核组织的软骨细胞3、软骨细胞4和软骨细胞5中。此外,作为激活Wnt信号通路的受体,LRP5主要在变性髓核细胞的软骨细胞5中高表达。六个基因,ANGPTL4,PTGES,IGFBP3、GDF15、TRIB3和TNFRSF10B,与细胞凋亡和炎症反应有关,并广泛存在于软骨细胞4和软骨细胞5中,可能与髓核细胞的退变密切相关。
结论:单细胞RNA测序显示Wnt/Ca2+信号在人正常和变性髓核细胞中的差异表达,这种差异表达可能与变性髓核细胞中软骨细胞4和软骨细胞5的丰度密切相关。在变性的髓核细胞中,LRP5激活Wnt5B,通过调节Wnt/Ca2+信号通路促进髓核细胞凋亡和炎症反应,从而促进椎间盘退变。软骨细胞4中的ANGPTL4、IGFBP3、PTGES和软骨细胞5中的TRIB3、GDF15、TNFRSF10B可能在此过程中起重要作用。