Yoshida Ryo, Kobayashi Kazuyuki, Onuma Kazuo, Yamamoto Ryuji, Chiba-Ohkuma Risako, Karakida Takeo, Yamakawa Shunjiro, Hosoya Noriyasu, Yamazaki Yasushi, Yamakoshi Yasuo
Department of Endodontology, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan.
Department of Dental Hygiene, Tsurumi Junior College, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan.
J Oral Biosci. 2025 Mar;67(1):100617. doi: 10.1016/j.job.2025.100617. Epub 2025 Jan 19.
Low-level laser therapy (LLLT) using an erbium-doped yttrium aluminum garnet (Er:YAG) laser provides a non-invasive approach applicable to various dental treatments. Here, we investigated the effects of Er:YAG laser irradiation on human dental pulp stem cells (hDPSCs) in an in vitro experiment.
The hDPSCs were categorized into four groups: laser-irradiated with activators (VLT: activated vitamin D, bone morphogenetic protein receptor inhibitor, and transforming growth factor-beta (TGF-β)) (LLLT(+)VLT), laser-irradiated without activators (LLLT(+)-only), non-irradiated with activators (LLLT(-)VLT), and non-irradiated without activators (control). Cell proliferation, hard tissue differentiation, TGF-β signaling pathway activity, mineralization induction, and gene expression levels were assessed using several approaches, including cell proliferation assays, ALP assays, western blotting, Alizarin Red S staining, X-ray diffraction, and quantitative polymerase chain reaction.
Cell proliferation was similar between the LLLT(+)-only and control groups. The ALP activity was significantly higher in LLLT(+)VLT group than in LLLT(-)VLT group (p < 0.05); however, it was suppressed by TGF-β signaling inhibitors. Western blotting showed enhanced SMAD3 phosphorylation in the LLLT(+)VLT group. The mineralization nodules and mRNA levels of matrix vesicle marker genes were significantly higher in LLLT(+)VLT group, and the nodules were partially composed of hydroxyapatite. The hard tissue formation marker gene expression in LLLT(+)VLT group was significantly higher (p < 0.05) than that in the LLLT(+)-only and control groups; however, it was unchanged or suppressed compared with that in LLLT(-)VLT group.
LLLT using an Er:YAG laser, combined with VLT, may promote the differentiation of hDPSCs into hard tissue-forming cells and enhance mineralization.
使用掺铒钇铝石榴石（Er:YAG）激光的低强度激光疗法（LLLT）提供了一种适用于各种牙科治疗的非侵入性方法。在此，我们在体外实验中研究了Er:YAG激光照射对人牙髓干细胞（hDPSCs）的影响。
将hDPSCs分为四组：用激活剂（VLT：活性维生素D、骨形态发生蛋白受体抑制剂和转化生长因子-β（TGF-β））进行激光照射（LLLT(+)VLT）、不用激活剂进行激光照射（仅LLLT(+)）、用激活剂但不进行照射（LLLT(-)VLT）以及既不用激活剂也不进行照射（对照组）。使用多种方法评估细胞增殖、硬组织分化、TGF-β信号通路活性、矿化诱导和基因表达水平，包括细胞增殖测定、碱性磷酸酶（ALP）测定、蛋白质印迹法、茜素红S染色、X射线衍射和定量聚合酶链反应。
仅LLLT(+)组和对照组之间的细胞增殖相似。LLLT(+)VLT组的ALP活性显著高于LLLT(-)VLT组（p < 0.05）；然而它被TGF-β信号抑制剂所抑制。蛋白质印迹法显示LLLT(+)VLT组中SMAD3磷酸化增强。LLLT(+)VLT组中矿化结节和基质小泡标记基因的mRNA水平显著更高，并且结节部分由羟基磷灰石组成。LLLT(+)VLT组中硬组织形成标记基因的表达显著高于仅LLLT(+)组和对照组（p < 0.05）；然而与LLLT(-)VLT组相比，其表达未改变或受到抑制。
使用Er:YAG激光的LLLT联合VLT可能促进hDPSCs向硬组织形成细胞的分化并增强矿化。
