State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China.
Cell Transplant. 2013;22(6):1061-73. doi: 10.3727/096368912X656036. Epub 2012 Sep 21.
Periodontal ligament cell (PDLC) sheets have been shown to contribute to periodontal tissue regeneration. Dental follicle cells (DFCs), acknowledged as the precursor cells of PDLCs, have demonstrated stemness, embryonic features, heterogeneity, and pluripotency. Therefore, we hypothesized that DFC sheets might be more effective and suitable for periodontal tissue regeneration than PDLC sheets. In this study, we compared the biological characteristics of DFC sheets and PDLC sheets in vitro. To investigate the potential for periodontal tissue regeneration in vivo, complexes composed of two types of cell sheets combined with dentin matrix were implanted subcutaneously into nude mice for 6 weeks. Our results showed that, when forming cell sheets, DFCs secreted richer extracellular matrix than PDLCs. And compared to DFCs, DFC sheets expressed high levels of calcification-related genes, including alkaline phosphatase (alp), bone sialoprotein (bsp), osteopontin (opn), runt-related transcription factor (runx2), as well as the periodontal ligament-specific genes collagen III (col III) and periostin, while the gene expression of bsp, osteocalcin (ocn), and opn were greatly increased in PDLC sheets, when compared to PDLCs. col I expression did not change significantly. However, cementum protein 23 (cp-23) expression increased several fold in PDLC sheets compared to PDLCs but decreased in DFC sheets compared to DFCs. DFC and PDLC sheets were both positive for Collagen I (Col I), cementum attachment protein (CAP), ALP, BSP, OCN, and OPN protein expression, and Col I, ALP, BSP, and OPN expression were increased after cell sheets were formed. Furthermore, the levels of laminin and fibronectin were higher in DFCs and DFC sheets than that of PDLCs and PDLC sheets, respectively. In vivo, DFC and PDLC sheets could both regenerate periodontal tissue-like structures, but DFC sheets demonstrated stronger periodontal regeneration potential than PDLC sheets. Therefore, DFC sheets derived from discarded dental follicle tissue after tooth extraction may be more advantageous for clinical periodontal tissue regeneration in the future.
牙周膜细胞（PDLC）片已被证明有助于牙周组织再生。牙囊细胞（DFC）被认为是 PDLC 的前体细胞，具有干细胞特性、胚胎特征、异质性和多能性。因此，我们假设 DFC 片可能比 PDLC 片更有效、更适合牙周组织再生。在这项研究中，我们比较了体外 DFC 片和 PDLC 片的生物学特性。为了研究体内牙周组织再生的潜力，将两种细胞片与牙本质基质组成的复合物皮下植入裸鼠体内 6 周。我们的结果表明，在形成细胞片时，DFC 分泌的细胞外基质比 PDLC 更丰富。与 DFC 相比，DFC 片表达高水平的钙化相关基因，包括碱性磷酸酶（alp）、骨涎蛋白（bsp）、骨桥蛋白（opn）、 runt 相关转录因子（runx2）以及牙周膜特异性基因胶原 III（col III）和骨膜蛋白，而 PDLC 片与 PDLC 相比，bsp、骨钙素（ocn）和 opn 的基因表达大大增加。col I 的表达没有明显变化。然而，与 DFC 相比，PDLC 片中的牙骨质蛋白 23（cp-23）表达增加了数倍，但在 DFC 片中减少了。DFC 和 PDLC 片均对 Collagen I（Col I）、牙骨质附着蛋白（CAP）、ALP、BSP、OCN 和 OPN 蛋白表达呈阳性，且细胞片形成后 Col I、ALP、BSP 和 OPN 表达增加。此外，DFC 和 DFC 片中的层粘连蛋白和纤维连接蛋白水平均高于 PDLC 和 PDLC 片。在体内，DFC 和 PDLC 片都可以再生牙周组织样结构，但 DFC 片显示出比 PDLC 片更强的牙周再生潜力。因此，从拔牙后废弃的牙囊组织中获得的 DFC 片可能在未来更有利于临床牙周组织再生。
