Instituto de Ciencias de la Salud, Universidad Veracruzana, Xalapa 91190, Veracruz, Mexico.
Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México (UNAM), A.P. 1-1010, Juriquilla 76000, Querétaro, Mexico.
Cells. 2023 Feb 8;12(4):540. doi: 10.3390/cells12040540.
Highly focused near-infrared (NIR) lasers have been used to induce fibroblast and neuron protrusions in a technique called optical guidance. However, little is known about the biochemical and biophysical effects that the laser provokes in the cell and optimal protocols of stimulation have not yet been established. Using intermittent NIR laser radiation and multivariate time series representations of cell leading edge movement, we analyzed the direction and velocity of cell protrusions. We found that the orientation and advance of PC12 neuron phenotype cells and 3T3 fibroblasts protrusions remain after the laser is turned off, but the observed increase in velocity stops when radiation ceases. For an increase in the speed and distance of cell protrusions by NIR laser irradiation, the cell leading edge needs to be advancing prior to the stimulation, and NIR irradiation does not enable the cell to switch between retracting and advancing states. Using timelapse imaging of actin-GFP, we observed that NIR irradiation induces a faster recruitment of actin, promoting filament formation at the induced cell protrusions. These results provide fresh evidence to understand the phenomenon of the optical guidance of cell protrusions.
高聚焦近红外（NIR）激光已被用于诱导成纤维细胞和神经元突起，这一技术被称为光学引导。然而，人们对激光在细胞中引发的生化和生物物理效应知之甚少，也尚未建立最佳的刺激方案。本研究使用间歇的 NIR 激光辐射和细胞前缘运动的多元时间序列表示，分析了细胞突起的方向和速度。我们发现，PC12 神经元表型细胞和 3T3 成纤维细胞突起的取向和前进在激光关闭后仍然存在，但当辐射停止时，观察到的速度增加停止。为了通过 NIR 激光照射增加细胞突起的速度和距离，细胞前缘需要在刺激之前前进，并且 NIR 照射不能使细胞在缩回和前进状态之间切换。通过对肌动蛋白-GFP 的延时成像，我们观察到 NIR 照射诱导肌动蛋白更快募集，促进诱导细胞突起处的丝形成。这些结果为理解细胞突起的光学引导现象提供了新的证据。
