Department of Restorative Dentistry, University at Buffalo, Buffalo, New York.
Department of Restorative Dentistry, University at Buffalo, Buffalo, New York.
J Endod. 2022 Jul;48(7):872-879. doi: 10.1016/j.joen.2022.04.009. Epub 2022 Apr 18.
Regeneration of the pulp-dentin complex hinges on functionally diverse growth factors, cytokines, chemokines, signaling molecules, and other secreted factors collectively referred to as trophic factors. The delivery of exogenous factors and the induced release of endogenous dentin-bound factors by conditioning agents have been explored toward these goals. The aim of this study was to investigate a promising regeneration strategy based on the conditioning of dental pulp cells (DPCs) with polyinosinic-polycytidylic acid (poly[I:C]) for the amplification of endogenous trophic factors.
DPCs were isolated from human dental pulps, propagated in culture, and treated with an optimized dose of poly(I:C). The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay and metabolite analysis were conducted to monitor the cytotoxicity of poly(I:C). Enzyme-linked immunosorbent assays and quantitative polymerase chain reaction assays were performed to quantify the induction of trophic factors in response to DPC conditioning. Statistical significance was P < .05.
The analysis of 32 trophic factors involved in Wnt signaling, cell migration and chemotaxis, cell proliferation and differentiation, extracellular matrix remodeling and angiogenesis, and immunoregulation revealed that DPCs abundantly express many trophic factors including AMF, BDNF, BMP2, FGF1, FGF2, FGF5, HGF, MCP1, NGF, SDF1, TGFβ1, TIMP1, TIMP2, TIMP3, and VEGFA, many of which were further induced by DPC conditioning; induction was significant for BDNF, EGF, HGF, LIF, MCP1, SDF1, IL6, IL11, MMP9, and TIMP1. Both DPC proliferation and lactate production (P < .05) were inhibited by 8 μg/mL poly(I:C) relative to the control.
In vitro DPC conditioning through poly(I:C) activation of toll-like receptor 3 led to the amplification of trophic factors involved in tissue repair. The strategy offers promise for endodontic regeneration and tooth repair and warrants further investigation.
牙髓-牙本质复合体的再生依赖于功能多样的生长因子、细胞因子、趋化因子、信号分子和其他分泌因子，统称为营养因子。为了实现这些目标，人们已经探索了外源性因子的传递和调理剂诱导释放内源性牙本质结合因子。本研究旨在探讨一种有前途的再生策略，即通过多聚肌苷酸-多聚胞苷酸（poly[I:C]）对牙髓细胞（DPCs）进行调理，以放大内源性营养因子。
从人牙髓中分离出 DPCs，在培养中增殖，并以优化剂量的 poly[I:C]处理。通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay）和代谢物分析来监测 poly[I:C]的细胞毒性。通过酶联免疫吸附测定（enzyme-linked immunosorbent assays）和定量聚合酶链反应（quantitative polymerase chain reaction assays）来检测 DPC 调理后营养因子的诱导情况。统计显著性为 P <.05。
对涉及 Wnt 信号转导、细胞迁移和趋化、细胞增殖和分化、细胞外基质重塑和血管生成以及免疫调节的 32 种营养因子的分析表明，DPCs 大量表达许多营养因子，包括 AMF、BDNF、BMP2、FGF1、FGF2、FGF5、HGF、MCP1、NGF、SDF1、TGFβ1、TIMP1、TIMP2、TIMP3 和 VEGFA，其中许多因子在 DPC 调理后进一步被诱导；BDNF、EGF、HGF、LIF、MCP1、SDF1、IL6、IL11、MMP9 和 TIMP1 的诱导作用显著。与对照组相比，8 μg/mL poly[I:C]相对抑制了 DPC 增殖和乳酸产生（P <.05）。
通过 poly[I:C]激活 Toll 样受体 3 对牙髓细胞进行体外调理，导致参与组织修复的营养因子扩增。该策略为牙髓再生和牙齿修复提供了希望，值得进一步研究。
