Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA.
Department of Surgery, Medical University of South Carolina, Charleston, SC, 29425, USA.
Sci Rep. 2018 May 23;8(1):8026. doi: 10.1038/s41598-018-26258-y.
While earlier studies have suggested that cells positive for hematopoietic markers can be found in dental tissues, it has yet to be confirmed. To conclusively demonstrate this, we utilized a unique transgenic model in which all hematopoietic cells are green fluorescent protein (GFP). Pulp, periodontal ligament (PDL) and alveolar bone (AvB) cell culture analysis demonstrated numerous GFP cells, which were also CD45 (indicating hematopoietic origin) and co-expressed markers of cellular populations in pulp (dentin matrix protein-1, dentin sialophosphoprotein, alpha smooth muscle actin [ASMA], osteocalcin), in PDL (periostin, ASMA, vimentin, osteocalcin) and in AvB (Runx-2, bone sialoprotein, alkaline phosphatase, osteocalcin). Transplantation of clonal population derived from a single GFP hematopoietic stem cell (HSC), into lethally irradiated recipient mice, demonstrated numerous GFP cells within dental tissues of recipient mice, which also stained for markers of cell populations in pulp, PDL and AvB (used above), indicating that transplanted HSCs can differentiate into cells in dental tissues. These hematopoietic-derived cells deposited collagen and can differentiate in osteogenic media, indicating that they are functional. Thus, our studies demonstrate, for the first time, that cells in pulp, PDL and AvB can have a hematopoietic origin, thereby opening new avenues of therapy for dental diseases and injuries.
虽然早期的研究表明，在牙髓组织中可以发现具有造血标记的细胞，但尚未得到证实。为了明确证明这一点，我们使用了一种独特的转基因模型，其中所有的造血细胞都是绿色荧光蛋白（GFP）。牙髓、牙周韧带（PDL）和牙槽骨（AvB）细胞培养分析显示有大量 GFP 细胞，这些细胞也表达 CD45（表明其造血起源），并同时表达牙髓细胞群体的标记物（牙本质基质蛋白 1、牙本质涎磷蛋白、α 平滑肌肌动蛋白[ASMA]、骨钙素）、PDL 中的标记物（骨膜蛋白、ASMA、波形蛋白、骨钙素）和 AvB 中的标记物（Runx-2、骨唾液蛋白、碱性磷酸酶、骨钙素）。将单个 GFP 造血干细胞（HSC）衍生的克隆群体移植到致死性辐照的受体小鼠中，结果显示受体小鼠的牙髓组织中有大量 GFP 细胞，这些细胞也表达了上述牙髓、PDL 和 AvB 细胞群体的标记物，表明移植的 HSCs 可以分化为牙髓组织中的细胞。这些造血衍生的细胞沉积胶原蛋白，并能在成骨培养基中分化，表明它们具有功能。因此，我们的研究首次证明，牙髓、牙周韧带和牙槽骨中的细胞可能具有造血起源，从而为口腔疾病和损伤的治疗开辟了新的途径。
