Department of Nanobiomedical Science & BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, South Korea.
Department of Nanobiomedical Science & BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, South Korea; Department of Oral Biochemistry, School of Dentistry, Dankook University, Cheonan, 31116, South Korea.
Exp Cell Res. 2024 Oct 1;442(2):114230. doi: 10.1016/j.yexcr.2024.114230. Epub 2024 Aug 31.
Human periodontal ligament cells (hPDLCs) contain multipotent postnatal stem cells that can differentiate into PDL fibroblasts, osteoblasts, and cementoblasts. Interaction between the extracellular environment and stem cells is an important factor for differentiation into other progenitor cells. To identify cell surface molecules that induce PDL fibroblastic differentiation, we developed a series of monoclonal antibodies against membrane/ECM molecules. One of these antibodies, an anti-PDL25 antibody, recognizes approximately a 100 kDa protein, and this antigenic molecule accumulates in the periodontal ligament region of tooth roots. By mass spectrometric analysis, we found that the antigenic molecule recognized by the anti-PDL25 antibody is fibroblast activation protein α (FAPα). The expression level of FAPα/PDL25 increased in TGF-β1-induced PDL fibroblasts, and this protein was localized in the cell boundaries and elongated processes of the fibroblastic cells. Ectopic expression of FAPα induced fibroblastic differentiation. In contrast, expression of representative markers for PDL differentiation was decreased by knock down and antibody blocking of FAPα/PDL25. Inhibition of dipeptidyl peptidase activity by a potent FAPα inhibitor dramatically inhibited PDL fibroblastic marker expression but did not affect in cell proliferation and migration.
人牙周韧带细胞（hPDLCs）含有多能的成体干细胞，可分化为牙周膜成纤维细胞、成骨细胞和成牙骨质细胞。细胞外环境与干细胞之间的相互作用是分化为其他祖细胞的重要因素。为了鉴定诱导牙周膜成纤维细胞分化的细胞表面分子，我们开发了一系列针对膜/ECM 分子的单克隆抗体。这些抗体之一，抗 PDL25 抗体，识别约 100 kDa 的蛋白质，该抗原分子在牙根牙周韧带区域积累。通过质谱分析，我们发现抗 PDL25 抗体识别的抗原分子是成纤维细胞激活蛋白α（FAPα）。TGF-β1 诱导的牙周膜成纤维细胞中 FAPα/PDL25 的表达水平增加，该蛋白定位于成纤维细胞的细胞边界和伸长的突起中。FAPα 的异位表达诱导成纤维细胞分化。相比之下，通过 FAPα/PDL25 的敲低和抗体阻断，代表性的牙周分化标志物的表达降低。通过有效的 FAPα 抑制剂抑制二肽基肽酶活性可显著抑制牙周膜成纤维细胞标志物的表达，但不影响细胞增殖和迁移。
