Dental pulp is a specialized tissue able to respond to infectious processes. Nevertheless, infection progress and root canal colonization trigger an immune-inflammatory response in tooth-surrounding tissues, leading to apical periodontitis and bone tissue destruction, further contributing to tooth loss. In order to shed some light on the effects of IL-4 on periradicular pathology development modulation, microtomographic, histological and proteomic analyses were performed using 60 mice, 30 wild type and 30 IL-4⁻/⁻. For that, 5 animals were used for microtomographic and histological analysis, and another 5 for proteomic analysis for 0, 7 and 21 days with/without pulp exposure. The periapical lesions were established in WT and IL-4⁻/⁻ mice without statistical differences in their volume, and the value of p < 0.05 was adopted as significant in microtomographic and histological analyses. Regarding histological analysis, IL-4⁻/⁻ mice show aggravation of pulp inflammation compared to WT. By using proteomic analysis, we have identified 32 proteins with increased abundance and 218 proteins with decreased abundance in WT animals after 21 days of pulp exposure, compared to IL-4⁻/⁻ animals. However, IL-4⁻/⁻ mice demonstrated faster development of apical periodontitis. These animals developed a compensatory mechanism to overcome IL-4 absence, putatively based on the identification of upregulated proteins related to immune system signaling pathways.

Significance: IL-4 might play a protective role in diseases involving bone destruction and its activity may contribute to host protection, mainly due to its antiosteoclastogenic action.

牙髓是一种能够对感染过程做出反应的特殊组织。然而，感染进展和根管定植会引发牙齿周围组织的免疫炎症反应，导致根尖周炎和骨组织破坏，进一步导致牙齿脱落。为了阐明 IL-4 对根周病理发育调节的影响，使用 60 只小鼠、30 只野生型和 30 只 IL-4 ^- / ^-进行了显微断层摄影、组织学和蛋白质组学分析。为此，将 5 只动物用于显微断层摄影和组织学分析，另外 5 只用于蛋白质组学分析，持续 0、7 和 21 天，有/无牙髓暴露。在 WT 和 IL-4 中建立了根尖周病变^- / ^-小鼠的体积没有统计学差异，p  < 0.05 的值在显微断层扫描和组织学分析中被认为是显着的。关于组织学分析，与WT相比，IL-4 ^- / ^-小鼠显示出牙髓炎症的恶化。^{通过使用蛋白质组学分析，与 IL-4 -} / ^-动物相比，在 21 天的纸浆暴露后，我们在 WT 动物中鉴定了 32 种丰度增加的蛋白质和 218 种丰度降低的蛋白质。然而，IL-4 ^- / ^-小鼠表现出更快的根尖周炎发展。这些动物开发了一种补偿机制来克服 IL-4 的缺失，推测是基于与免疫系统信号通路相关的上调蛋白的鉴定。

意义：IL-4 可能在涉及骨破坏的疾病中发挥保护作用，其活性可能有助于宿主保护，主要是由于其抗破骨细胞作用。