Department of Orthopaedics, Caoxian People's Hospital, Heze, China.
Eur Rev Med Pharmacol Sci. 2020 Nov;24(21):10975-10983. doi: 10.26355/eurrev_202011_23581.
Destruction of extracellular matrix (ECM), especially collagen II and aggrecan, is an essential feature of intervertebral disc degeneration (IDD). This project planned to elucidate the role of cartilage-derived morphogenetic protein-1 (CDMP-1) in the collagen II and aggrecan synthesis of nucleus pulposus (NP) cells under the IL-1β induced degeneration.
We cultured human primary NP cells in the different concentrations of IL-1β medium and analyzed the CDMP-1 level. Recombinant human CDMP-1 protein was used to co-culture with IL-1β to investigate its effects on collagen II and aggrecan synthesis of NP cells. Additionally, the bone morphogenetic protein type IB receptor (ALK6) gene silenced and upregulated NP cells were used to evaluate the function of ALK6 in the CDMP-1 treated NP cells. Collagen II, aggrecan, MMP9, MMP13, and TIMP4 expression level were analyzed to assess the ECM stability of NP cells.
CDMP-1 gene expression decreased in the IL-1β treated NP cells with a dose-dependent. Appropriate CDMP-1 protein supplement contributed to the collagen II and aggrecan production, the suppression of MMP9 and MMP13, and the upregulation of TIMP4. However, the silencing of ALK6 rejected the positive function of CDMP-1 on the collagen II and aggrecan; on the contrary, ALK6 upregulation magnified the CDMP-1 induced collagen II and aggrecan production.
CDMP-1 is efficient in promoting the collagen II and aggrecan synthesis of NP cells, which is probably based on the mediation of ALK6.
细胞外基质（ECM）的破坏，特别是 II 型胶原和聚集蛋白聚糖，是椎间盘退变（IDD）的一个重要特征。本项目计划阐明软骨衍生形态发生蛋白-1（CDMP-1）在白细胞介素-1β（IL-1β）诱导退变下对核髓核细胞（NP）中 II 型胶原和聚集蛋白聚糖合成中的作用。
我们在不同浓度的 IL-1β 培养基中培养人原代 NP 细胞，并分析 CDMP-1 水平。用重组人 CDMP-1 蛋白与 IL-1β 共培养，研究其对 NP 细胞中 II 型胶原和聚集蛋白聚糖合成的影响。此外，用骨形态发生蛋白型 IB 受体（ALK6）基因沉默和上调 NP 细胞，评估 ALK6 在 CDMP-1 处理的 NP 细胞中的功能。分析 II 型胶原、聚集蛋白聚糖、MMP9、MMP13 和 TIMP4 的表达水平，以评估 NP 细胞的 ECM 稳定性。
IL-1β 处理的 NP 细胞中 CDMP-1 基因表达呈剂量依赖性降低。适当的 CDMP-1 蛋白补充有助于促进 II 型胶原和聚集蛋白聚糖的产生，抑制 MMP9 和 MMP13，并上调 TIMP4。然而，ALK6 的沉默拒绝了 CDMP-1 对 II 型胶原和聚集蛋白聚糖的正向作用；相反，ALK6 的上调放大了 CDMP-1 诱导的 II 型胶原和聚集蛋白聚糖的产生。
CDMP-1 能有效促进 NP 细胞中 II 型胶原和聚集蛋白聚糖的合成，这可能是通过 ALK6 介导的。
