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Thank you for visiting our website. We are a relatively small lab with big ideas. We are part of a much larger group of investigators known collectively as the LLUMC Molecular Radiation Biology Laboratories. It is our hope that this website will educate, communicate, and incite scientific debate. As the PI of our little group, I hope to post our data and discuss potential mechanisms, consequences, and countermeasures. With a bit of luck we'll all learn something. The links to the left include our merry band as well as collaborating investigators and laboratories. The links to the right include our archive and blogroll. The banner above will always bring you back to the main page page. Take a look around and please feel free to leave a comment on our blog (try to keep it civil and constructive) or shoot us an e-mail. - Michael " Ubertramp " Pecaut
Summer Student Research
Posted by: Ubertramp on 2009.08.14
Categories & Tags: Gamma Radiation,Macrophage,New Results,Oxidative Burst,Radiation
Comments: None
Cory Pan is a student from Chaparral High School who spent the summer working in our lab as part of the Apprentice Bridge to College (ABC) minority research program. We only had about seven weeks to train him and get through a series of experiments. Due to the limitations in time, we decided that he should do some in vitro work characterizing one of our macrophage cell lines after exposure to radiation. Although he wasn’t allowed to irradiate the cells themselves, he did all of the other cell culture work on his own (with Erben looking over his shoulder). By working his butt off, he managed to run the experiment at least eight separate times. In the end, five of the experiments were good enough to include in the final analysis. He ended up with some pretty interesting results. During his last week, he had to present a poster describing his work to the public. The highlights of his poster are below.
Does Ethyl Pyruvate Protect Macrophages from Gamma Radiation Damage?
Background: In the last ten years, the threat of radiation exposure due to terrorist attacks (e.g. so called “dirty bombs”) or nuclear weaponry (e.g. by North Korea or Iran) has increased significantly. Similarly, exposure to radiation during space flight is also becoming a growing concern for astronauts, particularly with the increased emphasis on manned Lunar and Mars exploration. Outside the protective terrestrial atmosphere and geomagnetic field, astronauts will be exposed to radiation via Galactic Cosmic Rays (GCRs) and Solar Particle Events (SPEs). Considering the lengthy amount of exposure to radiation, and the numerous effects the radiation has on the human body, it is important to find new protective agents that will protect our immune system. Radiation is known to increase the amount of reactive oxygen species (ROS) in tissues. ROS are a byproduct of normal metabolism and are important in cell communication. However, excessive amounts of ROS can lead to tissue damage. In previous in vivo experiment models, EP had no detectable radioprotective or mitigating effects but it is suggested that EP might be an effective radioprotector and mitigator of the hematopietic syndrome induced by TBI (Epperl, 2008).
Macrophages are essential to our immune system because they are among the first cells to respond to an immune challenge. They not only devour potential pathogens, but they also present antigens to immunocytes involved in cell mediated immunity. ROS are particularly important in macrophage pathogen elimination because they contain small molecules such as free radicals that destroy pathogens.
This study focuses on the protective properties of the drug ethyl pyruvate (EP) on macrophages. In past studies, ethyl pyruvate, a simple aliphatic ester of pyruvic acid, has been shown to have anti-inflammatory effects in numerous cell culture and animal studies such as intestinal inflammatory response and neuroprotection in the brain. Similarly, radiation-induced tissue damage has also been linked to inflammatory mechanisms. Given that radiation is known to induce cancerous growth and that EP is known to reduce inflammatory responses, we hypothesized that EP would act as a radioprotective agent. Given that macrophages are a major component of immune defense, we believed that EP will have a profound radioprotective affect in this population.
Effects of Radiation and Ethyl Pyruvate on Macrophage Oxidative Function. All values represent Mean ± SEM. § ANOVA: Main effect of Radiation (P<0.001), Main effect of Ethyl Pyruvate (P<0.001).
Conclusion: There was significant radiation (P<0.001) and ethyl pyruvate (P<0.001) effects on all quantified parameters. In contrast, there were no significant interactions between radiation exposure and ethyl pyruvate treatment. This suggests that ethyl pyruvate does not protect macrophages against radiation for our endpoints. However, we can not rule out that EP alters radiation-induced cytokine expression. Previous studies have shown, a increase in EP concentration decreased the amount of TNF-a and IL-6, inflammatory cytokines, available (Marieke 2007). Therefore, we will look into the effect of ethyl pyruvate on cytokine as our next study.
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