Scientists learn from creepy skin parasites how to suppress pain
Although parasites known as cutaneous leishmaniasis cause disfiguring skin sores, they do not inflict any pain. This attribute allows them to postpone treatment, effectively prolonging their own survival.
Painless lesions investigated in mice
Now, for the first time, researchers have looked into the lesions on mouse skin to assess if there are any metabolic signalling pathways that are responsible for thwarting pain. The aim is to hopefully use this mechanism to help people suffering from debilitating pain through the development of non-narcotic pain medications.
“No one knows why these lesions are painless – but it has been thought that the parasite somehow manipulates the host physiological system,” said Abhay Satoskar, senior author of the study and professor of pathology in The Ohio State University College of Medicine.
“Based on our data, something the parasites do triggers pathways that suppress pain. How they do that, we’re still investigating. We hypothesize that any molecules the parasite’s presence is producing could be potential painkillers for other health problems.”
Through their work, the researchers were able to identify chemicals related with pain suppression using an unbiased mass spectrometry examination of lesions inflicted on mice. This led to the discovery of multiple metabolites – molecules that are intermediates or end products of a set of chemical reactions that occur within living organisms to maintain life – that have previously been associated to pain perception blockage.
Pain-relieving pathways linked to the brain’s endocannabinoid system, a complex cell-signaling system that plays a crucial role in regulating various physiological processes and maintaining homeostasis, were also detected.
Many questions left unanswered
The researchers are now working to understand how the infection affects the cells and whether this relationship is a direct or indirect one. Although they know that the parasites feed on these observed metabolites in order to reproduce, the discovery that key pain-suppression pathways are not activated in infected macrophages raises some questions about how these mechanisms are triggered and how they could possibly be recreated.
The research has thus far resulted in as many new questions as answers. However, the scientists still say it is an important step forward. “The exciting thing is that this is the first time we’ve begun to understand the cellular basis of why there is no pain in these lesions,” said Satoskar.
It should be noted that despite being painless, leishmaniasis is not harmless. Once bitten by an insect carrying the dangerous parasite, the resulting disease begins to primarily affect internal organs such as the spleen, liver, and bone marrow. Even though skin lesions are not always a prominent feature, the disease does carry the risk of prolonged fever, weight loss, hepatosplenomegaly and anemia.
Source: Interesting Engineering
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Scientists learn from creepy skin parasites how to suppress pain