Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgum, Yangsan, 626-770, Republic of Korea.
Lasers Med Sci. 2013 Feb;28(2):543-50. doi: 10.1007/s10103-012-1109-0. Epub 2012 May 3.
The aim of this study was to examine the effect of low-level laser therapy (LLLT) on the cell viability and the expression of hypoxia-inducible factor-1s (HIF-1s), bone morphogenic protein-2 (BMP-2), osteocalcin, type I collagen, transforming growth factor-β1 (TGF-β1), and Akt in hypoxic-cultured human osteoblasts. Human fetal osteoblast cells (cell line 1.19) were cultured under 1 % oxygen tension for 72 h. Cell cultures were divided into two groups. At the experimental side, low-level laser (808 nm, GaAlAs diode) was applied at 0, 24, and 48 h. After irradiation, each cell culture was incubated 24 h more under hypoxia. Total energy was 1.2, 2.4, and 3.6 J/cm(2), respectively. Non-irradiated cultures served as controls. Comparisons between the two groups were analyzed by t test; a p value <0.05 was considered statistically significant. Hypoxia resulted in a decrease in the expression of type I collagen, osteocalcin, and TGF-β1 (p < 0.001, p < 0.001, and p < 0.01, respectively). Cell viability and BMP-2 expression were not decreased by hypoxic condition. On the other hand, LLLT on hypoxic-cultured osteoblast promoted the expression of BMP-2, osteocalcin, and TGF-β1 (p < 0.05, p < 0.01, and p < 0.001, respectively). Cell proliferation was also increased time-dependently. However, hypoxia decreased in type I collagen expression (p < 0.001), and LLLT did not affect type I collagen expression in hypoxic-cultured osteoblasts. Furthermore, LLLT inhibited HIF-1 and Akt expression in hypoxic conditioned osteoblasts. We concluded that LLLT induces the expression of BMP-2, osteocalcin, and TGF- β1 in 1 % hypoxic-cultured human osteoblasts.
本研究旨在探讨低水平激光疗法（LLLT）对缺氧培养的人成骨细胞活力和缺氧诱导因子-1s（HIF-1s）、骨形态发生蛋白-2（BMP-2）、骨钙素、I 型胶原、转化生长因子-β1（TGF-β1）和 Akt 表达的影响。将人胎成骨细胞（细胞系 1.19）在 1%氧张力下培养 72 小时。细胞培养分为两组。实验组在 0、24 和 48 小时时给予低水平激光（808nm，GaAlAs 二极管）照射。照射后，每个细胞培养物在缺氧条件下再孵育 24 小时。总能量分别为 1.2、2.4 和 3.6 J/cm²。未照射的培养物作为对照。通过 t 检验分析两组间的比较；p 值<0.05 被认为具有统计学意义。缺氧导致 I 型胶原、骨钙素和 TGF-β1 的表达减少（p<0.001、p<0.001 和 p<0.01，分别）。BMP-2 和骨钙素的表达不受缺氧条件的影响。另一方面，LLLT 促进了缺氧培养的成骨细胞中 BMP-2、骨钙素和 TGF-β1 的表达（p<0.05、p<0.01 和 p<0.001，分别）。细胞增殖也随时间呈依赖性增加。然而，缺氧降低了 I 型胶原的表达（p<0.001），而 LLLT 并没有影响缺氧培养的成骨细胞中 I 型胶原的表达。此外，LLLT 抑制了缺氧条件下成骨细胞中 HIF-1 和 Akt 的表达。我们得出结论，LLLT 诱导 1%缺氧培养的人成骨细胞中 BMP-2、骨钙素和 TGF-β1 的表达。
