Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatology Hospital, School of Stomatology, Capital Medical University, No. 4 Tian Tan Xi Li, Dongcheng District, Beijing, 100050, China.
Department of Endodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, 100050, China.
Stem Cell Res Ther. 2020 Jul 6;11(1):271. doi: 10.1186/s13287-020-01791-8.
Mesenchymal stem cell (MSC)-based cartilage tissue regeneration is a treatment with great potential. How to enhance the MSC chondrogenic differentiation is a key issue involved in cartilage formation. In the present study, we seek to expound the phenotypes and mechanisms of DLX5 in chondrogenic differentiation function in MSCs.
Stem cells from apical papilla (SCAPs) were used. The Alcian Blue staining, pellet culture system, and cell transplantation in rabbit knee cartilage defect were used to evaluate the chondrogenic differentiation function of MSCs. Western blot, real-time RT-PCR, and ChIP assays were used to evaluate the molecular mechanisms.
DLX5 and HOXC8 expressions were upregulated during chondrogenic differentiation. In vitro results showed that DLX5 and HOXC8 enhanced the expression of chondrogenic markers including collagen II (COL2), collagen V (COL5), and sex-determining region Y box protein 9 (SOX9) and promoted the chondrogenic differentiation and the formation of cartilage clumps in the pellet culture system. Mechanically, DLX5 and HOXC8 formed protein complexes and negatively regulated the LncRNA, LINC01013, via directly binding its promoter. In vivo transplantation experiment showed that DLX5 and HOXC8 could restore the cartilage defect in the rabbit knee model. In addition, knock-down of LINC01013 enhanced the chondrogenic differentiation of SCAPs.
In conclusion, DLX5 and HOXC8 enhance the chondrogenic differentiation abilities of SCAPs by negatively regulating LINC01013 in SCAPs, and provided the potential target for promoting cartilage tissue regeneration.
间充质干细胞（MSC）为基础的软骨组织再生是一种具有巨大潜力的治疗方法。如何增强 MSC 的软骨分化能力是软骨形成中涉及的关键问题。在本研究中，我们旨在阐述 DLX5 在 MSC 软骨分化功能中的表型和机制。
使用根尖乳头干细胞（SCAP）。使用阿尔辛蓝染色、微球体培养系统和兔膝关节软骨缺损细胞移植来评估 MSC 的软骨分化功能。使用 Western blot、实时 RT-PCR 和 ChIP 检测来评估分子机制。
在软骨分化过程中，DLX5 和 HOXC8 的表达上调。体外结果表明，DLX5 和 HOXC8 增强了软骨标志物的表达，包括胶原蛋白 II（COL2）、胶原蛋白 V（COL5）和性别决定区 Y 框蛋白 9（SOX9），并促进了微球体培养系统中的软骨分化和软骨团块的形成。在机制上，DLX5 和 HOXC8 形成蛋白质复合物，并通过直接结合其启动子来负调控长非编码 RNA（LncRNA）LINC01013。体内移植实验表明，DLX5 和 HOXC8 可恢复兔膝关节模型中的软骨缺损。此外，敲低 LINC01013 可增强 SCAP 的软骨分化。
总之，DLX5 和 HOXC8 通过负调控 SCAP 中的 LINC01013 增强 SCAP 的软骨分化能力，并为促进软骨组织再生提供了潜在的靶点。
