Radiation effects on soluble metabolites in cultured HeLa cells examined by 1H MRS: Changes in concentration of glutathione and of lipid catabolites induced by gamma rays and proton beams

Abstract

SUMMARY Cultured HeLa cells were irradiated with a single acute dose of either gamma rays (40 Gy) or low-energy proton beams (20 Gy). 1H magnetic resonance spectra of intact cells harvested at different times after irradiation and of the correspondent perchloric acid (PCA) extracts prepared at different times after irradiation were run. Selected signals from glutathione and lactate were examined with the aim of investigating effects of irradiation on antioxidative stores and on mitochondrial activity. An increase of signal intensity of glutathione (GSH) takes place at 15 and 24 hr after irradiation, while a decrease of its signal intensity, accompanied by an increase of that of free glutamate, starts appearing 48 hr after irradiation. Lactate signal increases 48 hr after irradiation. Signals from lipid catabolites were also examined to explore their sensitivity in predicting the response to radiotherapy. Intensity ratios of signals of glycerophosphorylcholine and choline to that of phosphorylcholine increase with time after irradiation. Irradiating cells with gamma rays or proton beams at half a dose produces effects comparable to the metabolic variations presented here. The present experiments allow more insight into the complex pattern of the changes of GSH by irradiation and indicate that magnetic resonance spectroscopy signals from GSH, glutamate, lactate, and lipid catabolites are affected by irradiation. Finally, these data represent a first indication that the relative biological efficiency for some metabolic damage of low-energy proton beams with respect to gamma rays can reach a value of 2.

Metabolism of glutathione in tumour cells as evidenced by 1H MRS

“…The literature data report decrease of GSH level when cell density increases [9][10][11]. Our MRS data confirm the literature findings, as the relative concentration of GSH, G, decreased with time in culture in both MCF-7 and T98G cells (Fig.…”

UPLC-ESI-TOFMS-Based Metabolomics and Gene Expression Dynamics Inspector Self-Organizing Metabolomic Maps as Tools for Understanding the Cellular Response to Ionizing Radiation

“…16,17 At the same time, the metabolomic technologies have contributed to a general understanding of how metabolites and their concentrations change under defined conditions.18 However, in contrast to transcriptomics and proteomics, broadbased metabolomic studies have not been used to analyze the cellular effects of IR. Smallscale, directed approaches using high-sensitivity nuclear magnetic resonance spectroscopy (NMR) [19][20][21][22][23] have been applied to estimate the relative concentration changes of a small subset of metabolites (e.g., reduced glutathione) following IR, but a global metabolomic approach has not yet been reported. The effects of IR include activation of stress responses to reduce reactive oxygen species (ROS), an increase in nucleotide pools for unscheduled DNA repair, and increases in cellular energy intermediates.…”

Proteomic analysis of effects by x-rays and heavy ion in HeLa cells

“…In 2001, Grande et al . found that lactate of HeLa cells was increased 48 h after irradiation with high dose of gamma ray 55. Until recent years, with development of proteomic and genetic methods, the relationship between radiation and metabolism received more and more attention.…”