The impact of serotonin on the development of bystander damage assessed by γ-H2AX foci analysis

Abstract

Purpose: This investigation addresses the question of whether serum constituents have a modulating effect on the induction of bystander effects. It was carried out as part of an inter-laboratory comparison-exercise within the European Union-integrated project NOTE (Non-targeted effects of ionizing radiation). Serotonin is a neurotransmitter, which is present in the circulatory system and therefore in blood serum. Fetal bovine serum is an essential supplement to most cell culture media and contains different, batch-dependent concentrations of serotonin. In a recent publication, serotonin was found to have a strong modulating effect on the size of bystander effects detected using colony formation assays.

Materials and methods: We tested modulatory effects on bystander response detected by γ-H2AX (phosphorylated histone H2AX) foci formation in cells exposed to media of irradiated cells. Cells were grown in serum batches with different serotonin concentrations.

Results: While the data obtained with the three serum batches examined show a trend for increasing bystander response with increasing serotonin concentration, the effect failed to reach statistical significance.

Conclusions: Serotonin may have a modulating effect on radiation-induced bystander effects, but more work is required to conclusively characterize this contribution.

Keywords::

• Bystander effect
• serotonin
• γ-H2AX

Acknowledgements

This study was supported by a grant from the EU Sixth Framework Program: NOTE: 036465-FI6R.

Declaration of interest

The authors report no declaration of interest. The authors alone are responsible for the content and writing of the paper.