Canalis Ernesto, Schilling Lauren, Denker Emily
Departments of Orthopaedic Surgery, UConn Health, Farmington, CT 06030, USA.
Departments of Medicine, UConn Health, Farmington, CT 06030, USA.
Osteoarthr Cartil Open. 2024 Oct 10;6(4):100528. doi: 10.1016/j.ocarto.2024.100528. eCollection 2024 Dec.
To further our understanding of the role of tumor necrosis factor (TNF)α on the inflammatory response in chondrocytes.
We explored the effects of TNFα on the transcriptome of epiphyseal chondrocytes from newborn C57BL/6 mice at the total and single cell (sc) resolution.
Gene set enrichment analysis of total RNA-Seq from TNFα-treated chondrocytes revealed enhanced response to biotic stimulus, defense and immune response and cytokine signaling and suppressed cartilage and skeletal morphogenesis and development. scRNA-Seq analyzed 14,239 cells and 24,320 genes and distinguished 16 cell clusters. The more prevalent ones were constituted by limb bud and chondrogenic cells and fibroblasts comprising ∼73 % of the cell population. Genes expressed by joint fibroblasts were detected in 5 clusters comprising ∼45 % of the cells isolated. Pseudotime trajectory finding revealed an association between fibroblast and chondrogenic clusters which was not modified by TNFα. TNFα decreased the total cells recovered by 18.5 % and the chondrogenic, limb bud and mesenchymal clusters by 32 %, 27 % and 7 %, respectively. TNFα had profound effects on the insulin-like growth factor (IGF) axis decreasing , and and inducing and , explaining an inhibition of collagen biosynthesis, cartilage and skeletal morphogenesis. Ingenuity Pathway Analysis of scRNA-Seq data revealed that TNFα enhanced the osteoarthritis, rheumatoid arthritis, pathogen induced cytokine storm and interleukin 6 signaling pathways and suppressed fibroblast growth factor signaling.
Epiphyseal chondrocytes are constituted by diverse cell populations distinctly regulated by TNFα to promote inflammation and suppression of matrix biosynthesis and growth.
进一步了解肿瘤坏死因子（TNF）α在软骨细胞炎症反应中的作用。
我们以整体和单细胞（sc）分辨率探讨了TNFα对新生C57BL/6小鼠骨骺软骨细胞转录组的影响。
对TNFα处理的软骨细胞进行全RNA测序的基因集富集分析显示，对生物刺激、防御和免疫反应以及细胞因子信号传导的反应增强，而软骨和骨骼形态发生及发育受到抑制。scRNA测序分析了14239个细胞和24320个基因，并区分出16个细胞簇。其中较常见的是由肢芽细胞、软骨形成细胞和成纤维细胞组成，约占细胞总数的73%。在分离出的约45%的细胞中的5个簇中检测到关节成纤维细胞表达的基因。伪时间轨迹分析显示成纤维细胞和软骨形成细胞簇之间存在关联，且不受TNFα影响。TNFα使回收的细胞总数减少了18.5%，使软骨形成细胞、肢芽细胞和间充质细胞簇分别减少了32%、27%和7%。TNFα对胰岛素样生长因子（IGF）轴有深远影响，降低了 、 和 ，并诱导了 和 ，这解释了其对胶原蛋白生物合成、软骨和骨骼形态发生的抑制作用。对scRNA测序数据进行的 Ingenuity Pathway Analysis分析显示，TNFα增强了骨关节炎、类风湿性关节炎、病原体诱导的细胞因子风暴和白细胞介素6信号通路，并抑制了成纤维细胞生长因子信号传导。
骨骺软骨细胞由不同的细胞群体组成，TNFα对其有明显的调节作用，可促进炎症反应并抑制基质生物合成和生长。
