The aim of this study was to investigate the expression of the activating transcription factor 4 (ATF4) in odontogenic keratocysts (OKC), its association with hypoxia and M2-polarized macrophages infiltration, and its potential relationships with angiogenesis in OKC. The expression of ATF4, hypoxia-inducible factor 1α (HIF-1α), macrophage colony-stimulating factor (M-CSF), and receptor activator of nuclear factor κ-B ligand (RANKL) in OKC samples and normal oral mucosa (OM) was detected by immunohistochemistry. Meanwhile, microvessel density (MVD) was measured using antibody against CD31. M2-polarized macrophages were identified using double-staining for CD68⁺ and CD163⁺. The correlations of ATF4 with HIF-1α, M-CSF, and M2-polarized macrophages infiltration were determined by Spearman’s rank correlation test and hierarchical clustering. Human immortalized oral epithelial cells (HIOECs) were used in in vitro experiments. Our data showed that the expression of HIF-1α, ATF4, and M-CSF was significantly upregulated in the epithelium of OKC when compared with the OM. The expression of ATF4 was positively correlated with that of HIF-1α, M-CSF, MVD, and M2-polarized macrophages infiltration. Elevated expression of ATF4 in the epithelial lining of OKC may facilitate the M2 macrophages infiltration in response to hypoxia, leading to the development of OKC.

本研究的目的是研究活化转录因子4（ATF4）在牙源性角化囊肿（OKC）中的表达，其与缺氧和M2极化的巨噬细胞浸润的关系，以及其与OKC中血管生成的潜在关系。OKC样本和正常口腔黏膜（OM）中ATF4，缺氧诱导因子1α（HIF-1α），巨噬细胞集落刺激因子（M-CSF）和核因子κ-B配体受体激活剂的表达通过免疫组织化学检测。同时，使用针对CD31的抗体测量微血管密度（MVD）。使用CD68 ⁺和CD163 ⁺双重染色鉴定M2极化的巨噬细胞。通过Spearman秩相关检验和层次聚类确定ATF4与HIF-1α，M-CSF和M2极化的巨噬细胞浸润的相关性。在体外实验中使用了人类永生化口腔上皮细胞（HIOEC）。我们的数据显示，与OM相比，OKC上皮中的HIF-1α，ATF4和M-CSF的表达显着上调。ATF4的表达与HIF-1α，M-CSF，MVD和M2极化的巨噬细胞浸润呈正相关。OKC上皮内衬中ATF4的高表达可能促进M2巨噬细胞对缺氧的浸润，从而导致OKC的发展。