Portuguese researchers have observed that weight loss due to the process of lipolysis could help control sleeping sickness.
- Sleeping sickness is caused by the parasite Trypanosoma brucei, transmitted to humans by the bite of the tsetse fly.
- Portuguese researchers have found that the parasite Trypanosoma brucei accumulates in disproportionate numbers in adipose tissue.
- This accumulation in adipose tissue is associated with weight loss caused by a mechanism called lipolysis. This process would have protective effects against Trypanosoma bruce.
Present in sub-Saharan Africa, sleeping sickness is caused by the parasite Trypanosoma brucei, transmitted to humans by the bite of the tsetse fly. One of the characteristic manifestations of this pathology is the disruption of the sleep cycle, which gives it its name. On average, less than a thousand new cases are recorded per year. “However, the relaxation of surveillance could be accompanied by an increase in the number of cases, such as that observed recently in Guinea following the Ebola epidemic in 2013”has warned the Pasteur Institute.
A new strategy to fight sleeping sickness
In order to better understand the response of the body affected by sleeping sickness, researchers from the Instituto de Medicina Molecular João Lobo Antunes (Portugal) carried out a study on mice. Thanks to this work, scientists have developed a new strategy to combat infection by Trypanosoma brucei.
“A few years ago, our laboratory discovered that the parasite responsible for sleeping sickness, Trypanosoma brucei, accumulates in disproportionate numbers in adipose tissue. We found this very interesting and directed our research to understand how the colonization of adipose tissue affects disease progression”, explained Luísa Figueiredo, lead author of the study and Professor at the Institute of Molecular Medicine at the University of Lisbon. She added: “the accumulation of parasites in these tissues is accompanied by weight loss. However, we discovered that this weight loss is largely due to the loss of adipose tissue by lipolysis.
Parasite Trypanosoma brucei : the mechanism of lipolysis would have a protective effect
There lipolysis is a process in the body that breaks down lipids, particularly triacylglycerols, ingested or stored in adipose tissue. For the purposes of this research, Portuguese scientists infected immunocompromised mice and mice with impaired lipolysis with the parasite. Trypanosoma brucei. “We found that in this case, lipolysis is largely driven by the host’s immune response to infection,” noted Henrique Machado, co-author of this work.
Secondly, the researchers determined whether lipolysis promoted the progression of sleeping sickness. According to their results, the loss of adipose tissue through lipolysis increased the life expectancy of infected mice. “This, coupled with the fact that lipolysis exerts control over parasite numbers, indicates that this response has a protective effect, in one way or another. Interestingly, we found that this protective effect is due to the release, during lipolysis, of free fatty acids which are toxic to the parasites and lead to their death (…) It is as if the host’s body sacrificed itself, losing fat mass , to kill parasites”, said Luísa Figueiredo. These initial findings could, in the future, lead to a new avenue for treating sleeping sickness through targeting the infection in adipose tissue.