Raaymakers Constantijn, et al.
Most poisonous herps have a highly specialized delivery
system (fangs, spines or stingers) to ensure that small amounts of poison make
it to the bloodstream of their prey (or predator). This study’s aim was to
examine how frog poison enters the bloodstream, while most toxins lack the
ability to penetrate epithelial tissue of the prey. Besides toxins, frogs also
produce antimicrobial peptides (AMPs) as an immune response capable of killing
a broad range of microorganisms through cell lysis. This study observed an
alternate application of AMPs, confirming that these antimicrobial peptide secreted
by frogs degrade and permeabilize the prey’s epithelial tissue allowing for
efficient transmission of toxins to the bloodstream.
In addition to being effective in capturing prey, AMPs increase
the effectiveness and efficiency of toxins as a predator defense. Not only do
AMPs allow for the transmission of toxins into the bloodstream, but they also accelerate
diffusion so quickly it serves effective in evading predators.
This study seemed interesting to me because amphibian AMPs
have attracted researchers for years now due to their role as an immune defense
mechanism and their potency against clinically important pathogens. It is a
great example of how a well understood mechanism can also serve an alternative
role as an anti-predator defense, as presented in this study.
Free access to the article is located using the link below:
3 comments:
What an interesting article and idea! What did the researchers do, and what was their evidence for this role for AMPs?
Dr. Welch,
To test for the role of AMPs they used epithelial cells cultured under two conditions:
1. a peptide pair of the toxin caerulein and the AMP caerulein precursor
2. just the toxin caeulein alone
To observe damage of epithelial cells, the presence of lactate dehydrogenese (LDH) indicates that the caeulein effectively damaged the epithelial cells.
Results showed that treating the cultures with just the caeulein toxin led to no LDH leakage; meaning that it was ineffective at damaging epithelial cells.
When co-administered with the AMP precursor, LDH leakage within three minutes showed rapid large scale damage to the cell membranes.
I agree with Dr. Welch, what a cool article! I think it is so interesting how these amphibian peptides can serve as a line of self defense for these animals by destroying microbes, but also be beneficial to humans in other ways. I was wondering, which species of frog was the research conducted on, and also what the AMP caerulein precursor was? Obviously, the caerulein was more able to cause damage to the cell membranes when combined with its precursor, which means that something about this precursor is important for activating this process.
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