Chellini Flaminia, Sassoli Chiara, Nosi Daniele, Deledda Cristiana, Tonelli Paolo, Zecchi-Orlandini Sandra, Formigli Lucia, Giannelli Marco
Department of Anatomy, Histology and Forensic Medicine, University of Florence, Florence, Italy. f _
Lasers Surg Med. 2010 Aug;42(6):527-39. doi: 10.1002/lsm.20861.
Dental lasers represent a promising therapeutic tool in the treatment of periodontal and peri-implant diseases. However, their clinical application remains still limited. Here, we investigated the potential biostimulatory effect of low pulse energy neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation on different cells representative of the oral microenvironment and elucidated the underlying molecular mechanisms.
Saos-2 osteoblasts, H-end endothelial cells, and NIH/3T3 fibroblasts pre-treated or not with photosensitizing dye methylene blue (MB), were irradiated with low pulse energy (20 mJ) and high repetition rate (50-70 Hz) Nd:YAG laser, and evaluated for cell viability and proliferation as well as for the expression of specific differentiation markers by confocal immunofluorescence and real-time RT-PCR. Changes in intracellular Ca(2+) levels after laser exposure were also evaluated in living osteoblasts.
Nd:YAG laser irradiation did not affect cell viability in all the tested cell types, even when combined with pre-treatment with MB, and efficiently stimulated cell growth in the non-sensitized osteoblasts. Moreover, a significant induction in the expression of osteopontin, ALP, and Runx2 in osteoblasts, type I collagen in fibroblasts, and vinculin in endothelial cells could be observed in the irradiated cells. Pre-treatment with MB negatively affected cell differentiation in the unstimulated and laser-stimulated cells. Notably, laser irradiation also caused an increase in the intracellular Ca(2+) in osteoblasts through the activation of TRPC1 ion channels. Moreover, the pharmacologic or genetic inhibition of these channels strongly attenuated laser-induced osteopontin expression, suggesting a role for the laser-mediated Ca(2+) influx in regulating osteoblast differentiation.
Low pulse energy and high repetition rate Nd:YAG laser irradiation may exert a biostimulative effect on different cells representative of the oral microenvironment, particularly osteoblasts. Pre-treatment with MB prior to irradiation hampers this effect and limits the potential clinical application of photosensitizing dyes in dental practice.
牙科激光是治疗牙周病和种植体周围疾病的一种有前景的治疗工具。然而，其临床应用仍然有限。在此，我们研究了低脉冲能量钕钇铝石榴石（Nd:YAG）激光照射对口腔微环境中不同代表性细胞的潜在生物刺激作用，并阐明了其潜在的分子机制。
用低脉冲能量（20 mJ）和高重复频率（50 - 70 Hz）的Nd:YAG激光照射经或未经光敏染料亚甲蓝（MB）预处理的人骨肉瘤细胞系（Saos - 2）成骨细胞、人脐静脉内皮细胞（H - end）和小鼠胚胎成纤维细胞（NIH/3T3），通过共聚焦免疫荧光和实时逆转录 - 聚合酶链反应（RT - PCR）评估细胞活力、增殖以及特定分化标志物的表达。还在活的成骨细胞中评估了激光照射后细胞内钙离子（Ca(2+)）水平的变化。
Nd:YAG激光照射在所有测试的细胞类型中均未影响细胞活力，即使与MB预处理联合使用时也是如此，并且能有效刺激未致敏的成骨细胞生长。此外，在照射后的细胞中可观察到成骨细胞中骨桥蛋白、碱性磷酸酶（ALP）和Runx2的表达显著诱导，成纤维细胞中I型胶原蛋白的表达显著诱导，内皮细胞中纽蛋白的表达显著诱导。MB预处理对未刺激和激光刺激的细胞中的细胞分化有负面影响。值得注意的是，激光照射还通过激活瞬时受体电位阳离子通道蛋白1（TRPC1）离子通道导致成骨细胞内Ca(2+)增加。此外，这些通道的药理学或基因抑制强烈减弱了激光诱导的骨桥蛋白表达，表明激光介导的Ca(2+)内流在调节成骨细胞分化中起作用。
低脉冲能量和高重复频率的Nd:YAG激光照射可能对口腔微环境中不同代表性细胞，特别是成骨细胞产生生物刺激作用。照射前用MB预处理会阻碍这种作用，并限制了光敏染料在牙科实践中的潜在临床应用。
Zotero 插件