Department of Periodontal Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
Department of Biological Endodontics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
J Periodontal Res. 2024 Jun;59(3):530-541. doi: 10.1111/jre.13244. Epub 2024 Mar 19.
The purpose of this study is to investigate regenerative process by immunohistochemical analysis and evaluate periodontal tissue regeneration following a topical application of BDNF to inflamed 3-wall intra-bony defects.
Brain-derived neurotrophic factor (BDNF) plays a role in the survival and differentiation of central and peripheral neurons. BDNF can regulate the functions of non-neural cells, osteoblasts, periodontal ligament cells, endothelial cells, as well as neural cells. Our previous study showed that a topical application of BDNF enhances periodontal tissue regeneration in experimental periodontal defects of dog and that BDNF stimulates the expression of bone (cementum)-related proteins and proliferation of human periodontal ligament cells.
Six weeks after extraction of mandibular first and third premolars, 3-wall intra-bony defects were created in mandibular second and fourth premolars of beagle dogs. Impression material was placed in all of the artificial defects to induce inflammation. Two weeks after the first operation, BDNF (25 and 50 μg/mL) immersed into atelocollagen sponge was applied to the defects. As a control, only atelocollagen sponge immersed in saline was applied. Two and four weeks after the BDNF application, morphometric analysis was performed. Localizations of osteopontin (OPN) and proliferating cell nuclear antigen (PCNA)-positive cells were evaluated by immunohistochemical analysis.
Two weeks after application of BDNF, periodontal tissue was partially regenerated. Immunohistochemical analyses revealed that cells on the denuded root surface were positive with OPN and PCNA. PCNA-positive cells were also detected in the soft connective tissue of regenerating periodontal tissue. Four weeks after application of BDNF, the periodontal defects were regenerated with cementum, periodontal ligament, and alveolar bone. Along the root surface, abundant OPN-positive cells were observed. Morphometric analyses revealed that percentage of new cementum length and percentage of new bone area of experimental groups were higher than control group and dose-dependently increased.
These findings suggest that BDNF could induce cementum regeneration in early regenerative phase by stimulating proliferation of periodontal ligament cells and differentiation into periodontal tissue cells, resulting in enhancement of periodontal tissue regeneration in inflamed 3-wall intra-bony defects.
本研究通过免疫组织化学分析探讨再生过程，并评估局部应用脑源性神经营养因子（BDNF）于炎症性三壁骨内缺损后牙周组织的再生情况。
脑源性神经营养因子（BDNF）在中枢和周围神经元的存活和分化中发挥作用。BDNF 可以调节非神经细胞、成骨细胞、牙周膜细胞、内皮细胞以及神经细胞的功能。我们之前的研究表明，局部应用 BDNF 可增强犬牙周实验性缺损中的牙周组织再生，BDNF 可刺激骨（牙骨质）相关蛋白的表达和人牙周膜细胞的增殖。
在拔除下颌第一和第三前磨牙 6 周后，在下颌第二和第四前磨牙中制备三壁骨内缺损。所有人工缺损中均放置印模材料以诱导炎症。第一次手术后 2 周，将浸有 BDNF（25 和 50μg/ml）的去端胶原海绵应用于缺损处。作为对照，仅将浸有生理盐水的去端胶原海绵应用于缺损处。BDNF 应用后 2 周和 4 周进行形态计量学分析。通过免疫组织化学分析评估骨桥蛋白（OPN）和增殖细胞核抗原（PCNA）阳性细胞的定位。
BDNF 应用后 2 周，牙周组织部分再生。免疫组织化学分析显示，在裸露根面的细胞呈 OPN 和 PCNA 阳性。在再生牙周组织的软组织中也检测到 PCNA 阳性细胞。BDNF 应用后 4 周，缺损处再生了牙骨质、牙周韧带和牙槽骨。在根面附近观察到大量 OPN 阳性细胞。形态计量学分析显示，实验组的新牙骨质长度百分比和新骨面积百分比高于对照组，且呈剂量依赖性增加。
这些发现表明，BDNF 通过刺激牙周膜细胞增殖和向牙周组织细胞分化，可能在炎症性三壁骨内缺损的早期再生阶段诱导牙骨质再生，从而增强炎症性三壁骨内缺损的牙周组织再生。
