Department of Odontology, Section of Molecular Periodontology, Umeå University, Umeå, Sweden; Department of Odontology, Section of Oral and Maxillofacial Surgery, Umeå University, Umeå, Sweden.
Department of Odontology, Section of Molecular Periodontology, Umeå University, Umeå, Sweden.
Acta Odontol Scand. 2024 Sep 11;83:486-492. doi: 10.2340/aos.v83.41391.
Signal regulatory protein alpha (SIRPα) is mainly expressed by cells of myeloid origin. This membrane glycoprotein is shown to be involved in regulation of different inflammatory conditions, such as colitis and arthritis. However, SIRPα has not been investigated in relationship to periodontitis, an inflammatory condition affecting the tooth supporting tissues. We aim to investigate if resident cells in the periodontium express SIRPα and whether a possible expression is affected by inflammatory conditions. Primary human keratinocytes, fibroblasts, periodontal ligament cells, and osteoblasts were cultured with or without the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) or interleukin-1-beta (IL-1β). All different periodontal cell types showed a basal mRNA expression of SIRPα. Pro-inflammatory cytokines induced a 2-3-fold significant increase in SIRPα expression in both cultured human gingival fibroblasts and osteoblasts but neither in keratinocytes nor in periodontal ligament cells. Tissue sections from human gingival tissue biopsies were histochemically stained for SIRPα. Epithelial keratinocytes and gingival fibroblasts stained positive in sections from periodontally healthy as well as in sections from periodontitis. In periodontitis sections, infiltrating leukocytes stained positive for SIRPα. We highlight our finding that oral keratinocytes, gingival fibroblasts, and periodontal ligament cells do express SIRPα, as this has not been presented before. The fact that inflammatory stimulation of gingival fibroblasts increased the expression of SIRPα, while an increased expression by gingival fibroblasts in periodontitis tissue in situ could not be detected, is indeed contradictory.
信号调节蛋白 α（SIRPα）主要表达于髓系细胞。该膜糖蛋白参与调控多种炎症反应，如结肠炎和关节炎。然而，SIRPα在牙周炎中的作用尚未被研究，牙周炎是一种影响牙齿支持组织的炎症性疾病。我们旨在研究牙周组织中的固有细胞是否表达 SIRPα，以及其表达是否受炎症条件的影响。原代人角质形成细胞、成纤维细胞、牙周膜细胞和成骨细胞在有或没有促炎细胞因子肿瘤坏死因子-α（TNF-α）或白细胞介素-1-β（IL-1β）的情况下进行培养。所有不同的牙周细胞类型均显示出 SIRPα 的基础 mRNA 表达。促炎细胞因子诱导培养的人牙龈成纤维细胞和成骨细胞中 SIRPα 的表达显著增加 2-3 倍，但在角质形成细胞和牙周膜细胞中均未增加。来自人牙龈组织活检的组织切片用 SIRPα 的组织化学染色进行染色。来自牙周健康和牙周炎的组织切片中，上皮角质形成细胞和牙龈成纤维细胞均呈阳性染色。我们强调我们的发现，即口腔角质形成细胞、牙龈成纤维细胞和牙周膜细胞确实表达 SIRPα，因为这之前尚未被报道过。事实上，牙龈成纤维细胞的炎症刺激增加了 SIRPα 的表达，而在牙周炎组织原位中未检测到牙龈成纤维细胞的表达增加，这确实是矛盾的。
