Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block, Level 8, IE Kent Ridge Road, Singapore, 119228
Eur Cell Mater. 2021 Mar 1;41:216-232. doi: 10.22203/eCM.v041a16.
Conventional root canal treatment replaces the infected pulp with defined materials. Alternative cell-based tissue engineering strategies aim to regenerate a fully functional pulp within the root canal. Despite recent advances in this area, however, the regeneration of an innervated pulp remains a major challenge in the field. Both graphene (2DG) and pulsed electromagnetic fields (PEMFs) independently have been shown to promote diverse cellular developmental programs. The present study showed that 2DG promoted the neurogenic induction of human dental pulp stem cells (hDPSCs) by upregulating and accelerating the expression of mature neuronal markers. Notably, 2DG induced the highest expression of transient receptor potential canonical cation channel type 1 (TRPC1) during early neurogenesis. As brief PEMF exposure promotes in vitro differentiation by activating a TRPC1-mitochondrial axis, an opportunity to combine 2DG with developmentally targeted PEMF exposure for synergistic effects was realizable. Neurogenic gene expression, neurotransmitter release, and reactive oxygen species (ROS) production were greatly enhanced by a brief (10 min) and low amplitude (2 mT) PEMF exposure timed to coincide with the highest TRPC1 expression from hDPSCs on 2DG. In contrast, hDPSCs on glass were less responsive to PEMF exposure. The capacity of PEMFs to promote neurogenesis was precluded by the administration of penicillin/streptomycin, mirroring previous studies demonstrating that aminoglycoside antibiotics block TRPC1-mediated calcium entry and verifying the contribution of TRPC1 in this form of magnetoreception. Hence, graphene created a more conducive environment for subsequent PEMF-stimulated neurogenic induction of hDPSCs through their mutual capacity to activate TRPC1with subsequent ROS production.
传统的根管治疗用特定材料替代感染的牙髓。替代的基于细胞的组织工程策略旨在在根管内再生具有完整功能的牙髓。然而，尽管在这一领域取得了最近的进展，具有神经支配的牙髓的再生仍然是一个主要挑战。单独的石墨烯（2DG）和脉冲电磁场（PEMFs）都已被证明可以促进各种细胞发育程序。本研究表明，2DG 通过上调和加速成熟神经元标志物的表达，促进人牙髓干细胞（hDPSCs）的神经发生诱导。值得注意的是，2DG 在早期神经发生过程中诱导瞬时受体电位经典阳离子通道型 1（TRPC1）的最高表达。由于短暂的 PEMF 暴露通过激活 TRPC1-线粒体轴促进体外分化，因此有机会将 2DG 与针对发育的 PEMF 暴露相结合以产生协同作用。神经发生基因表达、神经递质释放和活性氧（ROS）产生通过短暂（10 分钟）和低幅度（2 mT）的 PEMF 暴露大大增强，该暴露与 hDPSCs 在 2DG 上的 TRPC1 表达最高时同时发生。相比之下，玻璃上的 hDPSCs 对 PEMF 暴露的反应性较低。青霉素/链霉素的给药排除了 PEMFs 促进神经发生的能力，这与先前的研究一致，表明氨基糖苷类抗生素阻断 TRPC1 介导的钙内流，并验证了 TRPC1 在这种形式的磁受体中的贡献。因此，石墨烯通过它们共同激活 TRPC1 的能力为随后的 PEMF 刺激 hDPSCs 的神经发生诱导创造了更有利的环境，随后产生 ROS。
