Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia 166, Bangu, Santo André, SP 09210-170, Brazil.
J Biomed Opt. 2012 Oct;17(10):101516. doi: 10.1117/1.JBO.17.10.101516.
Low-level laser therapy (LLLT) is an emerging therapeutic approach for several clinical conditions. The clinical effects induced by LLLT presumably scale from photobiostimulation/photobioinhibition at the cellular level to the molecular level. The detailed mechanism underlying this effect remains unknown. This study quantifies some relevant aspects of LLLT related to molecular and cellular variations. Malignant breast cells (MCF-7) were exposed to spatially filtered light from a He-Ne laser (633 nm) with fluences of 5, 28.8, and 1000 mJ/cm². The cell viability was evaluated by optical microscopy using the Trypan Blue viability test. The micro-Fourier transform infrared technique was employed to obtain the vibrational spectra of each experimental group (control and irradiated) and identify the relevant biochemical alterations that occurred due to the process. It was observed that the red light influenced the RNA, phosphate, and serine/threonine/tyrosine bands. We found that light can influence cell metabolism depending on the laser fluence. For 5 mJ/cm², MCF-7 cells suffer bioinhibition with decreased metabolic rates. In contrast, for the 1 J/cm² laser fluence, cells present biostimulation accompanied by a metabolic rate elevation. Surprisingly, at the intermediate fluence, 28.8 mJ/cm², the metabolic rate is increased despite the absence of proliferative results. The data were interpreted within the retrograde signaling pathway mechanism activated with light irradiation.
低水平激光疗法（LLLT）是一种新兴的治疗方法，适用于多种临床病症。LLLT 诱导的临床效果可能从细胞水平的光生物刺激/光生物抑制扩展到分子水平。其作用的详细机制尚不清楚。本研究量化了与分子和细胞变化相关的一些 LLLT 的相关方面。将恶性乳腺细胞（MCF-7）暴露于氦氖激光（633nm）的空间滤波光下，其辐照度分别为 5、28.8 和 1000mJ/cm²。使用台盼蓝活力检测法通过光学显微镜评估细胞活力。采用微傅里叶变换红外技术获得每个实验组（对照和辐照）的振动光谱，并确定由于该过程而发生的相关生化变化。结果表明，红光会影响 RNA、磷酸盐和丝氨酸/苏氨酸/酪氨酸带。我们发现，光可以根据激光辐照度影响细胞代谢。对于 5mJ/cm²，MCF-7 细胞受到生物抑制，代谢率降低。相反，对于 1J/cm²的激光辐照度，细胞呈现生物刺激，伴随着代谢率的升高。令人惊讶的是，在中间辐照度 28.8mJ/cm²下，尽管没有增殖结果，代谢率仍会升高。这些数据是根据光照射激活的逆行信号通路机制进行解释的。
