Transcriptome analysis of periodontal tissue response after immediate replantation and delayed replantation

Objective: This study aimed to identify the transcriptome profiles from periodontal tissues of replanted teeth and evaluate the functional differences of transcriptomes between immediate replantation and delayed replantation in a rat teeth avulsion animal model. Background: In dental avulsion, the prognosis of replanted teeth is hardly favorable in delayed replantation. After tooth replantation, complex inflammatory responses occur to return homeostasis in periodontal tissue. Various types of cytokines are produced in inflammatory microenvironment and these cytokines determine the periodontal tissue responses. Methods: Maxillary first molars of Sprague–Dawley rats were extracted and exposed to dry environment, then replanted. The animals were divided into two groups according to extra–oral time: immediate replantation group (dry for 5 min) and delayed replantation (dry for 60 min). Either 3 or 7 days after replantation, the animals were sacrificed. The palatal gingival tissues were harvested for mRNA–sequencing. Hallmark gene set enrichment analysis were performed to predict the function of transcriptomes. Normalized enrichment score (NES) was generated to determine the functional differences between the groups. Results: Hallmark gene sets enriched in delayed replantation at 3 days were oxidative phosphorylation (NES=2.82, q < 0.001) and TNF–α signaling via NF–κB pathway (NES= 1.52, q=0.034). At 7 days, TNF–α signaling via NF–κB pathway (NES=–1.82, q=0.002), angiogenesis (NES=–1.66, q =0.01), and TGF–β signaling pathway (NES=–1.46, q=0.051) were negatively highlighted in delayed replantation compared to immediate replantation. Conclusions: Transcriptome profiles were significantly different between immediate replantation and delayed replantation. The responses of periodontal tissues were associated with TNF–α signaling via NF–κB pathway. However, the enrichment score of this pathway were changed with time–dependent manner between immediate replantation and delayed replantation. Maxillary first molars of Sprague–Dawley rats were extracted and exposed to dry environment, then replanted. The animals were divided into two groups according to extra–oral time: immediate replantation group (IR; dry for 5 min) and delayed replantation (DR; dry for 60 min). Either 3 or 7 days after replantation, the animals were sacrificed.

研究目的：本研究旨在鉴定再植牙牙周组织的转录组谱（transcriptome profiles），并基于大鼠牙齿撕脱伤动物模型，评估即刻再植与延迟再植之间的转录组功能差异。研究背景：在牙齿撕脱伤中，延迟再植的再植牙预后往往不佳。牙齿再植术后，牙周组织为恢复稳态会触发复杂的炎症反应。炎症微环境中会产生多种细胞因子，这些细胞因子决定了牙周组织的应答模式。研究方法：提取Sprague-Dawley大鼠的上颌第一磨牙，置于干燥环境中后进行再植。根据离体时长将实验动物分为两组：即刻再植组（干燥环境放置5分钟）与延迟再植组（干燥环境放置60分钟）。分别于再植后3天或7天处死动物，采集腭侧牙龈组织进行mRNA测序（mRNA-sequencing）。通过特征基因集富集分析（Hallmark gene set enrichment analysis）预测转录组的功能，并生成标准化富集得分（Normalized Enrichment Score, NES）以比较两组间的功能差异。研究结果：再植后3天，延迟再植组富集的特征基因集包括氧化磷酸化（NES=2.82, q < 0.001）以及经NF-κB通路的TNF-α信号通路（NES=1.52, q=0.034）。再植后7天，与即刻再植组相比，延迟再植组中经NF-κB通路的TNF-α信号通路（NES=-1.82, q=0.002）、血管生成（NES=-1.66, q=0.01）以及TGF-β信号通路（NES=-1.46, q=0.051）呈现负富集状态。研究结论：即刻再植与延迟再植的转录组谱存在显著差异。牙周组织的应答反应与经NF-κB通路的TNF-α信号通路密切相关，但该通路的富集得分随时间在两组间呈现动态变化。提取Sprague-Dawley大鼠的上颌第一磨牙，置于干燥环境中后进行再植。根据离体时长将实验动物分为两组：即刻再植组（IR；干燥环境放置5分钟）与延迟再植组（DR；干燥环境放置60分钟）。分别于再植后3天或7天处死动物。