Dental Follicle Cells Participate in Tooth Eruption via the RUNX2-MiR-31-SATB2 Loop
Dental Follicle Cells Participate in Tooth Eruption via the RUNX2-MiR-31-SATB2 Loop
复制标题
牙囊细胞通过 RUNX2-MiR-31-SATB2 环参与牙齿萌出
DOI：
10.1177/0022034515578908
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发表时间：
2015-07-01
影响因子：
7.6
通讯作者：
Jiang, H.
中科院分区：
文献类型：
--
作者：
Ge, J.;Guo, S.;Jiang, H.
锁骨颅骨发育不良（CCD）是以侏儒相关转录因子2（RUNX 2）突变为特征的疾病，其由于牙囊功能紊乱而导致牙齿萌出延迟。越来越多的证据揭示了一个关键的调控回路，包括RUNX 2，miR-31和特殊的富含AT的结合蛋白2（SATB 2），它们在间充质干细胞的稳态和功能中发挥作用。然而，这样的调控环是否在牙囊细胞（DFC）中起作用仍然未知。在此，我们研究了RUNX 2-miR-31-SATB 2在来自CCD患者的DFCs（DFCs-CCD）中的作用，以促进我们对物理牙齿萌出的理解。我们通过外显子组测序在具有典型临床表现的CCD患者中鉴定了RUNX 2外显子5上的新突变（c.634T>G，p.T212P）。与来自健康供体的DFCs相比，DFCs-CCD显示出显著较低的成骨、破骨细胞诱导和基质降解能力，并且具有较低的RUNX 2（miR-31的转录抑制剂）、较高的miR-31和下调的SATB 2。RANKL/OPG和RANKL/RANK比值降低以及基质金属蛋白酶9（MMP 9）和基质金属蛋白酶2（MMP 2）表达降低，可导致破骨细胞失活和骨基质重塑受到抑制。此外，RUNX 2-miR-31-SATB 2环在DFC-CCD中的作用通过内源性miR-31敲低揭示，这导致SATB 2和RUNX 2增加，以及破骨细胞诱导和基质降解能力增加。相反，SATB 2、RUNX 2、MMP 9、MMP 2和破骨细胞诱导因子的表达在正常DFC中异位miR-31过表达时下降。重要的是，体内siRUNX 2递送的新生小鼠在牙囊周围表现出较少的活化破骨细胞和延迟的牙齿萌出。总之，这些结果表明，RUNX 2突变/单倍不足干扰破骨细胞诱导的信号在DFC，这可能是负责在CCD患者的牙齿萌出延迟。RUNX 2-miR-31-SATB 2环的操作可能是促进CCD患者牙齿萌出的潜在方法。
Cleidocranial dysplasia (CCD) is characterized by the runt-related transcription factor 2 (RUNX2) mutation, which results in delayed tooth eruption due to disturbed functions of dental follicle. Accumulating evidence has revealed a key regulatory circuit, including RUNX2, miR-31, and special AT-rich binding protein 2 (SATB2) acting in concert in mesenchymal stem cell homeostasis and functions. However, whether such a regulatory loop works in dental follicle cells (DFCs) remains unknown. Herein, we investigated the roles of RUNX2-miR-31-SATB2 in DFCs from patients with CCD (DFCs-CCD) to advance our understanding regarding physical tooth eruption. We identified a novel mutation on exon 5 (c.634T>G, p.T212P) in RUNX2 via exome sequencing in the CCD patient with typical clinical presentations. Compared with DFCs from healthy donors, DFCs-CCD displayed significantly lower osteogenic, osteoclast-inductive, and matrix-degrading capacities and had lower RUNX2 (a transcriptional inhibitor of miR-31), higher miR-31, and downregulated SATB2. Lower ratios of RANKL/OPG and RANKL/RANK, as well as decreased expression of matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 2 (MMP2), would lead to inactivation of osteoclasts and suppression of bone matrix remodeling in DFCs-CCD. Furthermore, the roles of the RUNX2-miR-31-SATB2 loop in DFCs-CCD were revealed by endogenous miR-31 knockdown, which resulted in increased SATB2 and RUNX2, as well as osteoclast-inductive and matrix degradation capacities. Conversely, SATB2, RUNX2, MMP9, MMP2, and osteoclast-inductive factors expression declined upon ectopic miR-31 overexpression in normal DFCs. Importantly, neonatal mice with in vivo siRUNX2 delivery exhibited less activated osteoclasts around dental follicles and delayed tooth eruption. Together, these results suggest that RUNX2 mutation/haploinsufficiency disturbs osteoclast-inductive signaling in DFCs, which may be responsible for delayed tooth eruption in CCD patients. Manipulation of the RUNX2-miR-31-SATB2 loop may be a potential way to facilitate tooth eruption in CCD patients.