Chu Yu-Hsiu, Chen Shu-Ya, Hsieh Yueh-Ling, Teng Yi-Hsien, Cheng Yu-Jung
Department of Physical Therapy and Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan.
Brain Research and Disease Center, China Medical University, Taichung, Taiwan.
Lasers Med Sci. 2018 Feb;33(2):279-286. doi: 10.1007/s10103-017-2364-x. Epub 2017 Nov 3.
Low-level laser therapy (LLLT), widely used in physiotherapy, has been known to enhance wound healing and stimulate cell proliferation, including fibroblast and endothelial cells. Applying LLLT can increase cell proliferation in many kinds of cells including fibroblasts and endothelial cells. However, the protective mechanisms of LLLT on endothelial apoptosis remain unclear. We hypothesized LLLT can protect endothelial cells from inflammation-induced apoptosis. Human endothelial cell line, EA.hy926 cells, and TNF-α/cycloheximide (TNF/CHX) were used to explore the protective effects of LLLT (660 nm) on inflammation-induced endothelial apoptosis. Cell viability, apoptosis, caspase-3/7/8/9 activity, MAPKs signaling, NF-κB activity, and inducible/endothelial nitric oxide synthase (iNOS/eNOS) expression were measured. Our results showed that LLLT increased EA.hy926 cell proliferation, attenuated the TNF/CHX-induced apoptosis, and reduced the TNF/CHX-mediated caspase-3/7/8/9 activation. In addition, LLLT increased ERK MAPK phosphorylation and suppressed the TNF/CHX-increased p38 MAPK, JNK, IKK phosphorylation, NF-κB translocation, and iNOS expression. The caspases-3 cleavage and cell death were not increased in cells treating with ERK inhibitor U0126, which implicated that ERK is not to be responsible for the protective effects of LLLT. After treating with p38 mitogen-activated protein kinase (MAPK) activator, the protection of LLLT in cell apoptosis was no longer existed, showing that LLLT protected the endothelial cells by suppressing p38 MAPK signaling. Our results provide a new insight into the possible molecular mechanisms in which LLLT protects against inflammatory-induced endothelial dysfunction.
低强度激光疗法（LLLT）在物理治疗中广泛应用，已知其可促进伤口愈合并刺激细胞增殖，包括成纤维细胞和内皮细胞。应用LLLT可增加多种细胞（包括成纤维细胞和内皮细胞）的增殖。然而，LLLT对内皮细胞凋亡的保护机制仍不清楚。我们推测LLLT可保护内皮细胞免受炎症诱导的凋亡。使用人内皮细胞系EA.hy926细胞以及肿瘤坏死因子-α/放线菌酮（TNF/CHX）来探究LLLT（660nm）对炎症诱导的内皮细胞凋亡的保护作用。检测细胞活力、凋亡、半胱天冬酶-3/7/8/9活性、丝裂原活化蛋白激酶（MAPKs）信号传导、核因子-κB（NF-κB）活性以及诱导型/内皮型一氧化氮合酶（iNOS/eNOS）表达。我们的结果表明，LLLT增加了EA.hy926细胞增殖，减轻了TNF/CHX诱导的凋亡，并降低了TNF/CHX介导的半胱天冬酶-3/7/8/9活化。此外，LLLT增加了细胞外调节蛋白激酶（ERK）MAPK磷酸化，并抑制了TNF/CHX增加的p38 MAPK、应激活化蛋白激酶（JNK）、IκB激酶（IKK）磷酸化、NF-κB易位以及iNOS表达。在用ERK抑制剂U0126处理的细胞中，半胱天冬酶-3裂解和细胞死亡并未增加，这表明ERK对LLLT的保护作用无影响。在用p38丝裂原活化蛋白激酶（MAPK）激活剂处理后，LLLT对细胞凋亡的保护作用不再存在，表明LLLT通过抑制p38 MAPK信号传导来保护内皮细胞。我们的结果为LLLT预防炎症诱导的内皮功能障碍的可能分子机制提供了新的见解。
