Wnt5a suppresses inflammation-driven intervertebral disc degeneration via a TNF-α/NF-κB-Wnt5a negative-feedback loop
Wnt5a suppresses inflammation-driven intervertebral disc degeneration via a TNF-α/NF-κB-Wnt5a negative-feedback loop
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Wnt5a 通过 TNF-α/NF-κB –Wnt5a 负反馈环路抑制炎症驱动的椎间盘退变
DOI：
10.1016/j.joca.2018.04.002
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发表时间：
2018-07-01
影响因子：
7
通讯作者：
Liu, H.
中科院分区：
文献类型：
--
作者：
Li, Z.;Zhang, K.;Liu, H.
目的：本研究旨在探讨Wnt 5a在炎症驱动的椎间盘退变（inflammatory-driven椎间盘degeneration，IVDD）中的分子作用。通过RT-qPCR和蛋白质印迹评估Wnt 5a对基质产生的影响。小干扰RNA（siRNA）、启动子缺失试验和启动子结合位点突变体被用于揭示Wnt 5a在TNF-α诱导的基质金属蛋白酶（MMP）表达中的分子作用。结果：Wnt 5a在中度变性的人NP组织中表达增高，其表达模式与TNF-α相似。在NP细胞中，Wnt 5a显著增加聚集蛋白聚糖和胶原II的表达。抑制JNK或干扰Sox 9基因表达显著抑制Wnt 5a诱导的基质产生。AP-1（JunB）结合位点位于Sox 9启动子中，这些位点的突变破坏了Wnt 5 α诱导的Sox 9上调和随后的基质基因表达。值得注意的是，由TNF-α诱导的Wnt 5a以相反的方式抑制TNF-α-NF-κ B（p65）信号传导和随后的MMPs表达。结论：Wnt 5a可通过激活JNK-AP 1（JunB）信号通路以Sox 9依赖的方式增加基质生成，并通过抑制NF-κ B信号通路拮抗TNF-α诱导的MMPs表达上调。这表明Wnt 5a通过TNF-α/NF-κ B-Wnt 5a负反馈回路抑制IVDD。(c)2018国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: This study was to investigate the molecular role of Wnt5a on inflammation-driven intervertebral disc degeneration (IVDD).Methods: The expression of Wnt5a was analyzed in human nucleus pulposus (NP) tissues with immunohistochemical staining. The effects of Wnt5a on matrix production were assessed by RT-qPCR and western blotting. Small interfering RNAs (siRNAs), promoter deletion assay, and promoter binding site mutant were used to reveal the molecular role of Wnt5a in TNF-alpha-induced matrix metalloproteinase (MMP) expression. The regulatory effects of TNF-alpha on Wnt5a were investigated with pharmachemical inhibitors and siRNA experiment.Results: The expression of Wnt5a was elevated in moderately degenerated human NP tissue with similar expression pattern of TNF-alpha. In NP cells, Wnt5a significantly increased aggrecan and collagen II expression. Inhibition of JNK or interfering Sox9 gene expression significantly suppressed Wnt5a-induced matrix production. AP-1(JunB) binding sites were located in Sox9 promoter and mutation of these sites sabotaged Wnt5 alpha-induced Sox9 up-regulation and subsequent matrix genes expression. Notably, Wnt5a, which was induced by TNF-alpha, on the other way round suppressed TNF-alpha-NF-kappa B (p65) signaling and subsequent MMPs expression. In vivo studies with MR imaging confirmed the protective role of Wnt5a in IVDD.Conclusions: Wnt5a, which can be induced by TNF-alpha, increased matrix production in a Sox9-dependent manner through the activation of JNK-AP1 (JunB) signaling, and antagonized TNF-alpha-induced upregulation of MMPs through the inhibition of NF-kappa B signaling. It indicates that Wnt5a suppresses IVDD through a TNF-alpha/NF-kappa B-Wnt5a negative-feedback loop. (c) 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.