Masuda Yoshiko Murakami, Yamada Yoshishige, Kimura Yuichi
Department of Endodontology, Showa University School of Dentistry, Kitasenzoku, Ohta-ku, Tokyo, Japan.
Photomed Laser Surg. 2012 Jun;30(6):315-9. doi: 10.1089/pho.2011.3173. Epub 2012 Apr 16.
After endothelial cells were ablated by neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation, we investigated the response of pulp cells by examining the expression of transforming growth factor beta-1 (TGF-β1).
The reaction of stimulated blood vessels is related to the initiation of dentinogenesis. After artificial injury of endothelial cells, pulp cells migrate to the site of the injured endothelial cells.
Rat aortic endothelial cells were cultured in the lower compartment of the experimental assembly, and a pulsed Nd:YAG laser was used to ablate these cells. Pulp cells were fluorescence labeled and cultured in the upper compartment. After 7-14 days of laser irradiation, total RNA was extracted from the cells in the lower chamber, and RT-PCR was performed to examine the expression of TGF-β1 and osteocalcin mRNA. TGF-β1 was also examined with immunohistochemistry.
Seven days after laser irradiation, migrating pulp cells that expressed TGF-β1 were observed in the lower compartment, and the expression of TGF-β1 mRNA and osteocalcin mRNA was altered. Without laser irradiation, few migrating pulp cells were observed, and the expression of TGF-β1 mRNA and osteocalcin mRNA was weak. These results suggested that TGF-β1 mRNA expression is detected earlier in pulp cells rather than in endothelial cells following injury to endothelial cells.
Using the Nd:YAG laser as an ablative stimulant, this study model was useful for investigating pulp-endothelial cell interactions in reparative dentinogenesis.
在用钕钇铝石榴石（Nd:YAG）激光照射消融内皮细胞后，我们通过检测转化生长因子β1（TGF-β1）的表达来研究牙髓细胞的反应。
受刺激血管的反应与牙本质形成的起始有关。在内皮细胞人工损伤后，牙髓细胞迁移至受损内皮细胞部位。
将大鼠主动脉内皮细胞培养于实验装置的下室，并用脉冲Nd:YAG激光消融这些细胞。将牙髓细胞进行荧光标记并培养于上室。激光照射7 - 14天后，从下室的细胞中提取总RNA，进行逆转录聚合酶链反应（RT-PCR）以检测TGF-β1和骨钙素mRNA的表达。还通过免疫组织化学检测TGF-β1。
激光照射7天后，在下室观察到表达TGF-β1的迁移牙髓细胞，且TGF-β1 mRNA和骨钙素mRNA的表达发生改变。未进行激光照射时，观察到的迁移牙髓细胞很少，且TGF-β1 mRNA和骨钙素mRNA的表达较弱。这些结果表明，在内皮细胞损伤后，牙髓细胞中TGF-β1 mRNA的表达比内皮细胞中更早被检测到。
以Nd:YAG激光作为消融刺激物，该研究模型有助于研究修复性牙本质形成过程中牙髓 - 内皮细胞的相互作用。
