Department of Hematology, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran.
Lasers Med Sci. 2012 Mar;27(2):423-30. doi: 10.1007/s10103-011-0930-1. Epub 2011 May 20.
Bone marrow-derived mesenchymal stem cells (BMSCs) are promising for use in regenerative medicine. Several studies have shown that low-level laser irradiation (LLLI) could affect the differentiation and proliferation of MSCs. The aim of this study was to examine the influence of LLLI at different energy densities on BMSCs differentiation into neuron and osteoblast. Human BMSCs were cultured and induced to differentiate to either neuron or osteoblast in the absence or presence of LLLI. Gallium aluminum arsenide (GaAlAs) laser irradiation (810 nm) was applied at days 1, 3, and 5 of differentiation process at energy densities of 3 or 6 J/cm(2) for BMSCs being induced to neurons, and 2 or 4 J/cm(2) for BMSCs being induced to osteoblasts. BMSCs proliferation was evaluated by MTT assay on the seventh day of differentiation. BMSCs differentiation to neurons was assessed by immunocytochemical analysis of neuron-specific enolase on the seventh day of differentiation. BMSCs differentiation to osteoblast was tested on the second, fifth, seventh, and tenth day of differentiation via analysis of alkaline phosphatase (ALP) activity. LLLI promoted BMSCs proliferation significantly at all energy densities except for 6 J/cm(2) in comparison to control groups on the seventh day of differentiation. LLLI at energy densities of 3 and 6 J/cm(2) dramatically facilitated the differentiation of BMSCs into neurons (p < 0.001). Also, ALP activity was significantly enhanced in irradiated BMSCs differentiated to osteoblast on the second, fifth, seventh, and tenth day of differentiation (p < 0.001 except for the second day). Using LLLI at 810 nm wavelength enhances BMSCs differentiation into neuron and osteoblast in the range of 2-6 J/cm(2), and at the same time increases BMSCs proliferation (except for 6 J/cm(2)). The effect of LLLI on differentiation and proliferation of BMSCs is dose-dependent. Considering these findings, LLLI could improve current in vitro methods of differentiating BMSCs prior to transplantation.
骨髓间充质干细胞（BMSCs）在再生医学中具有广阔的应用前景。多项研究表明，低水平激光照射（LLLI）可以影响间充质干细胞的分化和增殖。本研究旨在探讨不同能量密度的 LLLI 对 BMSCs 向神经元和成骨细胞分化的影响。将人 BMSCs 进行培养，并在有无 LLLI 的情况下诱导其向神经元或成骨细胞分化。在分化过程的第 1、3 和 5 天，采用砷化镓铝（GaAlAs）激光照射（810nm），能量密度为 3 或 6J/cm(2) 时用于诱导 BMSCs 向神经元分化，能量密度为 2 或 4J/cm(2) 时用于诱导 BMSCs 向成骨细胞分化。在分化的第 7 天，通过 MTT 测定法评估 BMSCs 的增殖。在分化的第 7 天，通过神经元特异性烯醇化酶的免疫细胞化学分析评估 BMSCs 向神经元的分化。通过分析碱性磷酸酶（ALP）活性，在分化的第 2、5、7 和 10 天检测 BMSCs 向成骨细胞的分化。与对照组相比，除 6J/cm(2)外，在分化的第 7 天，所有能量密度的 LLLI 均显著促进 BMSCs 的增殖。在能量密度为 3 和 6J/cm(2)时，LLLI 显著促进 BMSCs 向神经元分化（p<0.001）。此外，在分化的第 2、5、7 和 10 天，照射的 BMSCs 向成骨细胞分化时，ALP 活性显著增强（除第 2 天外，p<0.001）。使用 810nm 波长的 LLLI 可增强 BMSCs 在 2-6J/cm(2)范围内向神经元和骨细胞的分化，同时增加 BMSCs 的增殖（除 6J/cm(2)外）。LLLI 对 BMSCs 分化和增殖的影响呈剂量依赖性。考虑到这些发现，LLLI 可以改善移植前 BMSCs 体外分化的现有方法。
