Aug 22, 2015 by Sci-News.com
A research team in the U.S. says it has discovered a drug that successfully combats the deadly effects of radiation exposure. A single injection of a synthetic peptide drug called Chrysalin 24 hours after lethal radiation exposure appears to significantly increase survival and delay mortality in mice by counteracting damage to the gastrointestinal system, according to the team, led by researchers at the University of Texas Medical Branch.
3D structure of Chrysalin. Image credit: Darrell Carney & Barbara Olszewska-Pazdrak, doi: 10.1517/14656560802401721.
In recent years, increasing threats of radiation exposure and nuclear disasters have become a significant concern for the U.S. and countries worldwide.
Exposure to high doses of radiation triggers a number of potentially lethal effects. Among the most severe is the gastrointestinal (GI) toxicity syndrome caused by the destruction of the intestinal barrier, resulting in bacterial translocation, systemic bacteremia, sepsis, and death.
The GI toxicity syndrome is triggered by radiation-induced damage to crypt cells in the small intestines and colon that must continuously replenish in order for the GI tract to work properly.
Crypt cells are especially susceptible to radiation damage and serve as an indicator of whether someone will survive after total body radiation exposure.
“The lack of available treatments that can effectively protect against radiation-induced damage has prompted a search for countermeasures that can minimize the effects of radiation after exposure, accelerate tissue repair in radiation-exposed individuals and increase the chances for survival following a nuclear event,” said Prof Darrell Carney of the University of Texas Medical Branch.
“Because radiation-induced damage to the intestines plays such a key role in how well a person recovers from radiation exposure, it’s crucial to develop novel medications capable of preventing GI damage,” said Dr Carney, who is CEO of Chrysalis BioTherapeutics.
The investigational drug Chrysalin – a synthetic 23-amino acid peptide – was developed for use in stimulating repair of skin, bone and muscle tissues.
The drug, also known as TP508 or rusalatide acetate, has previously been shown to begin tissue repair by stimulating proper blood flow, reducing inflammation and reducing cell death. In human clinical trials, it has been reported to increase healing of diabetic foot ulcers and wrist fractures with no drug-related adverse events.
“The current results suggest that the peptide may be an effective emergency nuclear countermeasure that could be delivered within 24 hours after exposure to increase survival and delay mortality, giving victims time to reach facilities for advanced medical treatment,” said Dr Carla Kantara from the University of Texas Medical Branch.
The results were published online this week in the journal Laboratory Investigation.
Carla Kantara et al. Novel regenerative peptide TP508 mitigates radiation-induced gastrointestinal damage by activating stem cells and preserving crypt integrity. Laboratory Investigation, published online August 17, 2015; doi: 10.1038/labinvest.2015.103
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