Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Oxid Med Cell Longev. 2022 Mar 15;2022:1792412. doi: 10.1155/2022/1792412. eCollection 2022.
Intervertebral disc degeneration (IVDD) remains a clinical challenge and requires more effective therapeutic targets. Long noncoding RNAs (lncRNAs) have emerged as critical modulators of multiple biological processes, such as cell proliferation and extracellular matrix (ECM) remodeling. Accordingly, the current study sets out to explore the influence of the lncRNA growth arrest-specific 5 (GAS5) on IVDD and investigate the possible involvement of microRNA-17-3p (miR-17-3p)/Angiopoietin-2 (Ang-2) axis. Firstly, the expression patterns of GAS5, miR-17-3p, and Ang-2 were characterized by RNA quantification from the isolated human degenerative nucleus pulposus (NP) tissues. miR-17-3p was found to express at an abnormal low level while GAS5 and Ang-2 expressed at aberrant high level in the human degenerative NP tissues. Utilizing dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays, GAS5 was found to competitively bound to miR-17-3p and further upregulate the expression of Ang-2, a target gene of miR-17-3p. Employing gain- and loss-of-function approaches, their expressions were altered in human degenerative nucleus pulposus cells (NPCs), followed by IL-1 treatment, in order to identify their roles in NP cell proliferation, apoptosis, and ECM metabolism. Silencing of GAS5 expression restrained the levels of cleaved caspase-3, cleaved caspase-7, cleaved caspase-9, MMP3, MMP13, ADAMTS4, and ADAMTS5 and increased collagen II and aggrecan levels. experiments also revealed that GAS5 depletion inhibited apoptosis and ECM degradation in HDNPCs, while elevating the proliferation through downregulation of Ang-2 by increasing miR-17-3p. Furthermore, data further validated that either GAS5 silencing or miR-17-3p reexpression alleviated IVDD degree with the help of IVDD mouse models. Altogether, our findings substantiated that downregulation of GAS5 reduced NPC apoptosis and promoted ECM remodeling, ultimately ameliorating the IVDD miR-17-3p-dependent inhibition of Ang-2. We hope our discoveries offer a fresh molecular insight that can aid the development of novel therapies against IVDD.
椎间盘退变（IVDD）仍然是一个临床挑战，需要更有效的治疗靶点。长链非编码 RNA（lncRNA）已成为多种生物过程的关键调节剂，如细胞增殖和细胞外基质（ECM）重塑。因此，本研究旨在探讨 lncRNA 生长停滞特异性 5（GAS5）对 IVDD 的影响，并研究 microRNA-17-3p（miR-17-3p）/血管生成素-2（Ang-2）轴的可能参与。首先，通过从分离的人退变髓核（NP）组织中进行 RNA 定量来描述 GAS5、miR-17-3p 和 Ang-2 的表达模式。在人退变 NP 组织中，miR-17-3p 表达异常低，而 GAS5 和 Ang-2 表达异常高。利用双荧光素酶报告、RNA 免疫沉淀和下拉实验，发现 GAS5 竞争性结合 miR-17-3p，并进一步上调 Ang-2 的表达，Ang-2 是 miR-17-3p 的靶基因。通过改变人退变髓核细胞（NPCs）的表达，并在 IL-1 处理后，采用增益和缺失功能方法，鉴定它们在 NP 细胞增殖、凋亡和 ECM 代谢中的作用。沉默 GAS5 表达可抑制 cleaved caspase-3、cleaved caspase-7、cleaved caspase-9、MMP3、MMP13、ADAMTS4 和 ADAMTS5 的水平，并增加胶原 II 和聚集蛋白聚糖的水平。实验还表明，通过增加 miR-17-3p 下调 Ang-2，GAS5 耗竭可抑制 HDNPCs 的凋亡并促进 ECM 降解，同时通过增加 Ang-2 促进增殖。此外，体内数据进一步验证了 GAS5 沉默或 miR-17-3p 再表达可通过 IVDD 小鼠模型减轻 IVDD 程度。总之，我们的研究结果证实，下调 GAS5 可减少 NPC 凋亡并促进 ECM 重塑，从而改善 IVDD。miR-17-3p 依赖抑制 Ang-2。我们希望我们的发现提供了新的分子见解，有助于开发针对 IVDD 的新疗法。
