Cory Pan
Summer High School Student
Department of Radiation Medicine
LLURM Radiobiology Research Laboratories
Loma Linda University
Chan Shun Pavilion, Rm. A-1010
11175 Campus St.
Loma Linda, CA 92354
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Research Focus: Radiation and Oxidative Burst in Macrophage Cell Lines
Research Summary: Spaceflight radiation is rapidly becoming a growing concern for astronauts due to effects on long term flights. Protecting immune cells can reduce the detrimental effects of radiation. The purpose of this study was to quantify the radioprotective effects of ethyl pyruvate (EP). EP is a simple aliphatic ester that has been shown to be protective in models of inflammatory disease, such as septic shock. This is important because of our hypothesis is that EP will protect macrophages from radiation damage. RAW 264.7 murine macrophage-like cells were plated on 96 wells plates with different concentrations of EP (1.25-10 mM). The plates were then exposed to 0, 0.5, 1, 2, or 4 Gray (Gy) gamma-irradiation with a 60Co source. The plates were incubated at 5% CO2 and 37C for 24 hours. At the appropriate timepoint, we characterized total live cell count using an acid phosphatase based assay as well as background reactive oxygen species (ROS) levels and zymosan-induced oxidative burst capacity using 2',7'-dichloro-dihydrofluorescin diacetate (DCFH-DA; Molecular Probes, Inc.). Fluorescence and absorbance for assays was measured simultaneously at the appropriate timepoint according to assay protocol using Infinite M200 florescence reader (Tecan, Mannedorf). The data show significant radiation effects (P<0.001) and ethyl pyruvate effects (P<0.001) but no major interaction between the two responses. (P>0.1) Therefore, ethyl pyruvate is not a protective agent for macrophages under gamma radiation. (Cory is a student from Chaparral High School who was working in the lab over the summer.)
