In vitromeasurements of oxygen consumption rates in hTERT-RPE cells exposed to low levels of red light
| Autor: | Cherry C. Castellanos, Jeffrey C. Wigle |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Oxidase test
Chemistry Cellular respiration chemistry.chemical_element 02 engineering and technology Oxidative phosphorylation 01 natural sciences Oxygen Electron transport chain Nitric oxide 010309 optics chemistry.chemical_compound 020210 optoelectronics & photonics 0103 physical sciences Respiration 0202 electrical engineering electronic engineering information engineering Biophysics Extracellular |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2210738 |
| Popis: | Exposure to 2.88 J/cm 2 of red light induces an adaptive response against a lethal pulse of 2.0 μm laser radiation in hTERT-RPE cells in vitro, but not in a knockdown mutant for vascular endothelial growth factor c (VEGF-C). The generally accepted initiation sequence for photobiomodulation is that absorption of red light by cytochome c oxidase (CCOX) of the electron transport chain increases the binding affinity of CCOX for O 2 vs. nitric oxide (NO). This results in displacement of NO by O 2 in the active site of CCOX, thereby increasing cellular respiration and intracellular ATP. We've previously reported that red-light exposure induces a small, but consistently reproducible, increase in NO levels in these cells. But the relative importance of NO and oxidative phosphorylation is unclear because little is known about the relative contributions of NO and ATP to the response. However, if NO dissociation from CCOX actually increases oxidative phosphorylation, one should see a corresponding increase in oxygen consumption. A Seahorse Extracellular Flux Analyzer was used to measure oxygen consumption rates (OCR) in normal and mutant cells as a proxy for oxidative phosphorylation. Both basal respiration and maximum respiration rates in normal cells are significantly higher than in the mutant. The normal cells have a significant amount of “excess capacity,” whereas the VEGF-C(KD) have little or none. The OCR in exposed normal cells is lower than in unexposed cells when measured immediately after exposure. The exposures used for these experiments had no effect on the OCR in mutant cells. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|