Abstract:

Objective: To investigate the expression level of paired related homeobox 2 (Prrx2) at different stages of mouse molar germ and its effect on molar germ development. Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the relative expression of paired related homeobox 1 (Prrx1) and Prrx2 in E12.5 to E18.5, P1, P3, P7, and E13.5 molar germ, hair, brain, heart, colon, kidney, lung, salivary gland and other tissues; small interfering RNA (siRNA) was used to silence the expression of Prrx2, then tooth germ development was observed via vitro culture systems; CCK8 test and cell scratch test were utilized to observe the proliferation and migration ability of molar germ mesenchymal cells. Results: According to the results of RT-qPCR, comparing with Prrx2 in other organs, it was highly expressed in the molars, hair and salivary glands of E13.5 mice; comparing with Prrx1, the expression level of Prrx2 at the late stage of tooth germ development (E16.5-E18.5) is still higher than that at the initial stage of development (E13.5); the results of in vitro tooth germ culture demonstrated that after silencing Prrx2, tooth germ width, height and tooth cusp height were reduced by (21.11±3.49)%, (12.08±5.30)% and (22.34±7.56)% (all P<0.05), respectively; CCK8 test and cell scratch test showed that the proliferation rate of tooth germ mesenchymal cells did not change after silencing Prrx2 (P>0.05), but the migration ability was suppressed (P<0.05). Conclusion: Prrx2 plays an important role in the process of molar germ morphogenesis; Prrx2 affects the growth of molar germ and the process of tooth cusp development via promoting the migration ability of molar germ mesenchymal cells.

Key words: tooth germ development, Prrx2, in vitro culture, mice

摘要：

目的：探究配对相关同源框2（paired related homeobox 2, Prrx2）在小鼠磨牙胚不同发育时期的表达及其对磨牙胚发育的影响。方法：利用实时定量聚合酶链反应（real-time quantitative polymerase chain reaction, RT-qPCR）分析配对相关同源框1（paired related homeobox 1, Prrx1）和Prrx2在小鼠胚胎12.5 d（E12.5）至E18.5，出生后1、3、7 d（P1、P3、P7）磨牙牙胚中的表达，以及其在E13.5磨牙、毛发、脑、心脏、结肠、肾、肺、唾液腺等组织中的相对表达情况；使用小干扰RNA（small interfering RNA, siRNA）沉默Prrx2基因的表达，通过对牙胚行体外器官培养，观察牙胚发育情况；并利用CCK8实验、细胞划痕实验观察牙胚间充质细胞的增殖和迁移能力。结果：RT-qPCR结果显示，相比其他组织，Prrx2在E13.5小鼠胚胎的磨牙、毛发、唾液腺中的表达量更高；相比于Prrx1，Prrx2磨牙胚发育后期(E16.5~E18.5）的表达水平仍高于初始阶段（E13.5）；牙胚体外培养结果显示，沉默Prrx2后，牙胚宽度、高度及牙尖高度分别减少了（21.11±3.49） %、（12.08±5.30） %和（22.34±7.56） %（均P<0.05）；CCK8实验、细胞划痕实验结果显示，沉默Prrx2后，牙胚间充质细胞增殖能力无变化（P>0.05）、迁移能力降低（P<0.05）。结论：Prrx2在牙胚形态成形的过程中，承担着重要的作用；Prrx2通过促进磨牙胚间充质细胞的迁移能力，进而影响磨牙胚生长和牙尖发育的进程。

关键词: 牙胚发育, Prrx2, 体外培养, 小鼠

CLC Number: 

• R782