Department of Orthodontics, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea.
J Endod. 2013 Jun;39(6):788-94. doi: 10.1016/j.joen.2013.01.011. Epub 2013 Mar 20.
The aim of this study was to examine the effect of pulp cell injection on host angiogenesis during wound healing.
Pulp cells were isolated from extracted premolars by the outgrowth method. Fluorescently labeled pulp cells or phosphate-buffered saline were locally injected into a mouse wound healing model. Wound healing was evaluated using photographs, histology, and real-time reverse-transcription polymerase chain reaction. Injected cells were traced. Angiogenesis was measured by performing immunohistochemical staining of CD31, a marker of vascular endothelial cells. The level of secreted vascular endothelial growth factor in the pulp cell conditioned medium (CM) was compared with the CM of fibroblasts and keratinocytes. The paracrine effect of pulp CM on angiogenesis was evaluated by tubular network formation using endothelial cells.
The local injection of pulp cells enhanced wound closure during the initial stage when compared to the injection of phosphate-buffered saline. The amount of extracellular matrix production and the expression of CD31+ cells were also increased in response to pulp cell injection when compared with the injection of phosphate-buffered saline. The fluorescently labeled pulp cells were engrafted into the hair follicles of the adjacent normal dermis but not into the wound site per se. A significantly higher level of vascular endothelial growth factor was secreted into the CM of pulp cells when compared with dermal fibroblast and keratinocytes. Tubular network formation of endothelial cells and the proliferation of dermal fibroblasts were significantly enhanced by the application of pulp cell CM when compared with control media.
Our results show that local injection of pulp cells is effective in enhancing wound healing during the initial proliferative phase, especially through paracrine mechanisms regulating host angiogenesis and proliferation.
本研究旨在探讨牙髓细胞注射对创伤愈合过程中宿主血管生成的影响。
采用体外培养法从拔除的前磨牙牙髓中分离牙髓细胞。将荧光标记的牙髓细胞或磷酸盐缓冲液局部注射到小鼠创伤愈合模型中。通过照片、组织学和实时逆转录聚合酶链反应评估伤口愈合。追踪注射的细胞。通过对血管内皮细胞标志物 CD31 的免疫组织化学染色测量血管生成。比较牙髓细胞条件培养基（CM）与成纤维细胞和角质形成细胞 CM 中分泌的血管内皮生长因子水平。通过内皮细胞管状网络形成评估牙髓 CM 对血管生成的旁分泌作用。
与磷酸盐缓冲液注射相比，牙髓细胞局部注射可在初始阶段增强伤口闭合。与磷酸盐缓冲液注射相比，牙髓细胞注射后细胞外基质的产生量和 CD31+细胞的表达也增加。荧光标记的牙髓细胞被植入相邻正常真皮的毛囊中，但不在伤口部位本身。与真皮成纤维细胞和角质形成细胞相比，牙髓细胞分泌的血管内皮生长因子水平显著升高。与对照培养基相比，牙髓细胞 CM 的应用显著增强了内皮细胞的管状网络形成和真皮成纤维细胞的增殖。
我们的结果表明，牙髓细胞的局部注射可有效增强创伤愈合的初始增殖阶段，特别是通过旁分泌机制调节宿主血管生成和增殖。
