Red and near‐infrared light induces intracellular Ca²⁺ flux via the activation of glutamate N‐methyl‐D‐aspartate receptors

Abstract

Red and near‐infrared (NIR) light effect on Ca2+ ions flux through the influence on N‐methyl‐D‐aspartate receptors (NMDARs) and their functioning in HeLa cells was studied in vitro. Cells were irradiated by 650 and 808 nm laser light at different power densities and doses and the obtained effect was compared with that caused by the pharmacological agents. The laser light was found to elevate Ca2+ influx into cell cytoplasm in a dose‐dependent manner without changes of the NMDAR functioning. Furthermore, the light of both wavelengths demonstrated the ability to elevate Ca2+ influx under the pharmacological blockade of NMDARs and also might partially abolish the blockade enhancing Ca2+ influx after selective stimulation of the receptors with NMDA. Simultaneously, the light at moderate doses demonstrated a photobiostimulating effect on cells. Based on our experiments and data reported in the literature, we suggest that the low‐power visible and NIR light can instigate a cell membrane depolarization via nonthermal activation, resulting in the fast induction of Ca2+ influx into cells. The obtained results also demonstrate that NIR light can be used for nonthermal and nonpharmacological stimulation of NMDARs in cancer cells.

Macrophages Modulated by Red/NIR Light: Phagocytosis, Cytokines, Mitochondrial Activity, Ca2+ Influx, Membrane Depolarization and Viability

“…6c,d). Such a pattern of the ROS generation is very similar to that observed for other types of cells under irradiation with red/NIR light, in particular, neuronal and cancerous ones (31,32).…”

“…Light power density was adjusted to be 0.1 W cm À2 and the light irradiation time was in 1 s -5 min interval (1 min of irradiation is equivalent to a dose of 6 J cm À2 , so the maximum irradiation dose was 30 J cm À2 ). These light power density and doses were chosen because red/NIR light with such parameters was shown to provide positive effects on cells and tissues, while not causing cell phototoxicity (1)(2)(3)(4)(5)(6)(7)(8)(31)(32)(33)(34)(35)(36).…”

“…Nonactivated macrophages should be also used to determine the effect of light on intracellular processes. As we recently reported, low dosages of light irradiation do not only cause an enhanced ROS generation but also alter cell membrane potential (CMP) and stimulate ion receptors responsible for Ca 2+ influx into neurons and cancer cells (31,32). However, these studies have been performed not on macrophages and red/NIR light is known to cause different responses in different cell lines.…”

Cellular transformations in near‐infrared light‐induced apoptosis in cancer cells revealed by label‐free CARS imaging

“…The PBM effect is also strongly dependent on the cell type: different cell lines demonstrate different responses to light irradiation . In particular, several studies showed that PBM can stimulate proliferation in some cell lines and cell death in others . For example, red and near infrared (NIR) light stimulate proliferation of human adipose‐derived stem cells and, at the same time, can effectively inhibit proliferation of fibroblasts .…”

Sequential PBM–Saffron Treatment in an Animal Model of Retinal Degeneration

“…[34] show that the exposition of near-infrared light might affect biological structure different from cytochrome c oxidase. In particular, they describe how PBM increases intracellular calcium via the activation of NMDA receptors [35]. Therefore, treatments applied might compete in the intracellular calcium flux.…”