Abstract：
OBJECTIVE: 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.
BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
摘要：
目的：本研究的目的是通过免疫组织化学分析研究再生过程，并评估局部应用BDNF治疗发炎的3壁骨内缺损后的牙周组织再生。
背景：脑源性神经营养因子（BDNF）在中枢和外周神经元的存活和分化中起作用。BDNF可以调节非神经细胞的功能，成骨细胞，牙周膜细胞，内皮细胞，以及神经细胞。我们先前的研究表明，局部应用BDNF可以增强狗实验性牙周缺损中的牙周组织再生，并且BDNF可以刺激骨（牙骨质）相关蛋白的表达和人牙周膜细胞的增殖。
方法：拔除下颌第一和第三前磨牙六周后，在比格犬的下颌第二和第四前磨牙中产生了3壁骨内缺损。将印模材料放置在所有人工缺损中以诱导炎症。第一次手术两周后，将浸入去端胶海绵中的BDNF（25和50μg/mL）应用于缺损。作为一种控制，仅使用浸入盐水中的atelocollagen海绵。BDNF应用后两周和四周，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。
结果：应用BDNF后两周，牙周组织部分再生。免疫组织化学分析显示，裸露根表面的细胞OPN和PCNA阳性。在再生牙周组织的软结缔组织中也检测到PCNA阳性细胞。应用BDNF后四周，牙骨质再生牙周缺损，牙周膜,和牙槽骨。沿着根表面，观察到丰富的OPN阳性细胞。形态学分析表明，实验组的新骨水泥长度百分比和新骨面积百分比高于对照组，并呈剂量依赖性增加。
结论：这些发现表明，BDNF可以通过刺激牙周膜细胞增殖并分化为牙周组织细胞，从而在再生早期诱导牙骨质再生。导致发炎的3壁骨内缺损的牙周组织再生增强。
背景：脑源性神经营养因子（BDNF）在中枢和外周神经元的存活和分化中起作用。BDNF可以调节非神经细胞的功能，成骨细胞，牙周膜细胞，内皮细胞，以及神经细胞。我们先前的研究表明，局部应用BDNF可以增强狗实验性牙周缺损中的牙周组织再生，并且BDNF可以刺激骨（牙骨质）相关蛋白的表达和人牙周膜细胞的增殖。
方法：拔除下颌第一和第三前磨牙六周后，在比格犬的下颌第二和第四前磨牙中产生了3壁骨内缺损。将印模材料放置在所有人工缺损中以诱导炎症。第一次手术两周后，将浸入去端胶海绵中的BDNF（25和50μg/mL）应用于缺损。作为一种控制，仅使用浸入盐水中的atelocollagen海绵。BDNF应用后两周和四周，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。
结果：应用BDNF后两周，牙周组织部分再生。免疫组织化学分析显示，裸露根表面的细胞OPN和PCNA阳性。在再生牙周组织的软结缔组织中也检测到PCNA阳性细胞。应用BDNF后四周，牙骨质再生牙周缺损，牙周膜,和牙槽骨。沿着根表面，观察到丰富的OPN阳性细胞。形态学分析表明，实验组的新骨水泥长度百分比和新骨面积百分比高于对照组，并呈剂量依赖性增加。
结论：这些发现表明，BDNF可以通过刺激牙周膜细胞增殖并分化为牙周组织细胞，从而在再生早期诱导牙骨质再生。导致发炎的3壁骨内缺损的牙周组织再生增强。
