Gansau Jennifer, Grossi Elena, Rodriguez Levon, Wang Minghui, Laudier Damien M, Chaudhary Saad, Hecht Andrew C, Fu Wenyu, Sebra Robert, Liu Chuan-Ju, Iatridis James C
Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Osteoarthritis Cartilage. 2025 Jul;33(7):874-887. doi: 10.1016/j.joca.2025.02.791. Epub 2025 Mar 24.
To identify mechanisms and treatment targets in painful intervertebral disc (IVD) degeneration (IVDD) progression with a focus on pro-inflammatory tumor necrosis factor-alpha (TNFα)-receptor-1 (TNFR1) and pro-reparative TNFα receptor-2 (TNFR2) signaling.
IVDD tissues and cells from IVDD and autopsy subjects were analyzed with single-cell RNA-sequencing to identify cell populations expressing TNFR1 and TNFR2, and multiplexed array to identify inflammatory proteins in IVDD conditioned media (CM). Bulk RNA-seq evaluated inflammatory and cell cycle states of human annulus fibrosus (hAF) cells challenged with CM. hAF cell responses to TNFR1 and TNFR2 modulation were evaluated by treatment with TNFR1- and TNFR2-blocking antibodies and TNFR2-activator Atsttrin.
IVDD CM chemokines and cytokines were expressed primarily by a small macrophage population and at low levels by native IVD cells. CM-treated hAF cells exhibited TNFα-signaling responses with reduced metabolic rates (MTT: 0.75 [95%CI:0.67 to 0.82]), limited inflammatory responses (inferred from heatmap of 50 differentially expressed genes), and senescence (10.4% SA-β-Gal+ cells [95%CI:6.99 to 13.8]). TNFR1-inhibition sufficiently restored hAF cell metabolism to enable robust pro-inflammatory responses to the complex IVDD CM cytokine mixture (multiple assays,). TNFR2-staining was limited on human IVD cell membranes and TNFR2 modulation had no effect on hAF cells, together suggesting a lack of TNFR2-signaling in native IVD cells.
Secreted proteins from IVDD CM caused hAF cells to have reduced metabolic rates, attenuated inflammatory responses, and senescence indicating a TNFR1-dominated response with metabolic impairment. Meanwhile, human IVD cells lacked reparative TNFR2-signaling since its modulation caused no effects, to suggest enhanced TNFR2-signaling in IVD repair may need recruitment or delivery of macrophages or other TNFR2-expressing cells.
确定疼痛性椎间盘退变（IVDD）进展中的机制和治疗靶点，重点关注促炎肿瘤坏死因子-α（TNFα）受体-1（TNFR1）和促修复TNFα受体-2（TNFR2）信号传导。
对来自IVDD和尸检受试者的IVDD组织和细胞进行单细胞RNA测序，以鉴定表达TNFR1和TNFR2的细胞群体，并进行多重阵列分析以鉴定IVDD条件培养基（CM）中的炎症蛋白。批量RNA测序评估了用CM刺激的人纤维环（hAF）细胞的炎症和细胞周期状态。通过用TNFR1和TNFR2阻断抗体以及TNFR2激活剂Atsttrin处理，评估hAF细胞对TNFR1和TNFR2调节的反应。
IVDD CM趋化因子和细胞因子主要由一小部分巨噬细胞表达，而天然IVD细胞表达水平较低。用CM处理的hAF细胞表现出TNFα信号反应，代谢率降低（MTT：0.75 [95%CI：0.67至0.82]），炎症反应有限（从50个差异表达基因的热图推断），以及衰老（10.4% SA-β-Gal+细胞[95%CI：6.99至13.8]）。TNFR1抑制足以恢复hAF细胞的代谢，使其能够对复杂的IVDD CM细胞因子混合物产生强烈的促炎反应（多种测定）。TNFR2在人IVD细胞膜上的染色有限，并且TNFR2调节对hAF细胞没有影响，这共同表明天然IVD细胞中缺乏TNFR2信号传导。
IVDD CM分泌的蛋白质导致hAF细胞代谢率降低、炎症反应减弱和衰老，表明以TNFR1为主导的反应伴有代谢损伤。同时，人IVD细胞缺乏修复性TNFR2信号传导，因为其调节没有产生影响，这表明在IVD修复中增强TNFR2信号传导可能需要募集或递送巨噬细胞或其他表达TNFR2的细胞。
