Cellular Redox Profiling Using High-content Microscopy

The gill epithelial cell lines RTgill-W1, from Rainbow trout and ASG-10, from Atlantic salmon, exert different toxicity profiles towards rotenone

In order to ensure the proper use and interpretation of results from laboratory test systems, it is important to know the characteristics of your test system. Here we compare mitochondria and the handling of reactive oxygen species (ROS) in two gill epithelial cell lines, the well-known RTgill-W1 cell line from Rainbow trout and the newly established ASG-10 cell line from Atlantic salmon. Rotenone was used to trigger ROS production. Rotenone reduced metabolic activity and induced cell death in both cell lines, with RTgill-W1 far more sensitive than ASG-10. In untreated cells, the mitochondria appear to be more fragmented in RTgill-W1 cells compared to ASG-10 cells. Furthermore, rotenone induced mitochondrial fragmentation, reduced mitochondria membrane potential (Δψm) and increased ROS generation in both cell lines. Glutathione (GSH) and catalase is important to maintain the cellular oxidative balance by eliminating hydrogen peroxide (H₂O₂). In response to rotenone, both GSH and catalase depletion were observed in the RTgill-W1 cells. In contrast, no changes were found in the GSH levels in ASG-10, while the catalase activity was increased. In summary, the two salmonid gill cell lines have different tolerance towards ROS, probably caused by differences in mitochondrial status as well as in GSH and catalase activities. This should be taken into consideration with the selection of experimental model and interpretation of results.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-022-00560-0.

Effects of high intensity non-ionizing terahertz radiation on human skin fibroblasts

For the first time, the data have been obtained on the effects of high-intensity terahertz (THz) radiation (with the intensity of 30 GW/cm2, electric field strength of 3.5 MV/cm) on human skin fibroblasts. A quantitative estimation of the number of histone Н2АХ foci of phosphorylation was performed. The number of foci per cell was studied depending on the irradiation time, as well as on the THz pulse energy. The performed studies have shown that the appearance of the foci is not related to either the oxidative stress (the cells preserve their morphology, cytoskeleton structure, and the reactive oxygen species content does not exceed the control values), or the thermal effect of THz radiation. The prolonged irradiation of fibroblasts also did not result in a decrease of their proliferative index.

Rosiglitazone Protects Endothelial Cells From Irradiation-Induced Mitochondrial Dysfunction

Background and Purpose

Up to 50–60% of all cancer patients receive radiotherapy as part of their treatment strategy. However, the mechanisms accounting for increased vascular risks after irradiation are not completely understood. Mitochondrial dysfunction has been identified as a potential cause of radiation-induced atherosclerosis.

Materials and Methods

Assays for apoptosis, cellular metabolism, mitochondrial DNA content, functionality and morphology were used to compare the response of endothelial cells to a single 2 Gy dose of X-rays under basal conditions or after pharmacological treatments that either reduced (EtBr) or increased (rosiglitazone) mitochondrial content.

Results

Exposure to ionizing radiation caused a persistent reduction in mitochondrial content of endothelial cells. Pharmacological reduction of mitochondrial DNA content rendered endothelial cells more vulnerable to radiation-induced apoptosis, whereas rosiglitazone treatment increased oxidative metabolism and redox state and decreased the levels of apoptosis after irradiation.

Conclusion

Pre-existing mitochondrial damage sensitizes endothelial cells to ionizing radiation-induced mitochondrial dysfunction. Rosiglitazone protects endothelial cells from the detrimental effects of radiation exposure on mitochondrial metabolism and oxidative stress. Thus, our findings indicate that rosiglitazone may have potential value as prophylactic for radiation-induced atherosclerosis.