Genetically modified mice not to produce cysteine were forced to burn fat reserves and lost 30% of weight in a week. It is not yet possible to test this method in humans.
A new published in the journal Nature relates the discovery of a “switch” in the metabolism of genetically modified mice that led to an extraordinary loss of 30% of your body weight In just a week. Genetic alteration is the inability of mice producing cysteine amino acid.
The team, led by Evgeny Nudler and Dan L. Littman, found that the depletion of cysteine in the rats led to a serious break in cell energy metabolism. Without cysteine, mice cells could not generate coenzyme A (COA), a crucial molecule to turn food into energy. As a result, the animals began to Burn fat reservations to satisfy your energy needs.
CoA plays a central role In more than 100 metabolic reactions and supports about 4% of all enzymes. However, the study of the role of coa in adult mammals has been difficult because mice with defective production of co -normally do not survive childhood. This study marks the first detailed look at how the lack of cysteine and, consequently, COO, can disturb metabolism so deeply, explains.
Researchers observed that cysteine depletion triggered a series of responses to the interconnected stress in the mice, including the integrated response to stress (ISR) and the response to oxidative stress (OSR). Normally observed in cancer cells, this simultaneous activation of ISR and OSR in normal tissues forced animals to depend even more on the fat stored as fuel. At the same time, the GDF15 stress hormone levels have increasedreducing mice appetite and further accelerating their weight loss.
Although the findings raise intriguing possibilities for weight loss strategies, researchers warn that, for now, a diet without cysteine is practically impossible for humans. Cysteine is present in almost all foods and is essential for many biological processes, so its total elimination would be harmful. In addition, the elimination of cysteine could make organs more vulnerable to common toxins and medicines.
Interestingly, the study also suggests that plant -based diets, which are naturally poorer in amino acids which contains sulfur, such as cysteine and methionine, can contribute to modest health benefits. However, the extreme weight loss observed in the mice required both the elimination of the gene and a specialized diet.
“This work reveals a fundamental change in the way we think about metabolism,” said Nudler. “Although our focus is on understanding these mechanisms to a basic level, there is hope that one day we can take advantage of parts of this process to help people manage obesity safely. ”
