Type 1 diabetes prevented in mice by immune-cell-regulating peptide
A peptide called MOTS-c has shown promise in preventing type 1 diabetes, according to new tests in human cells in culture and live mice. The peptide seems to regulate the immune system, potentially leading to treatments for type 1 diabetes and other autoimmune diseases.
Type 1 diabetes begins when a patient’s immune system mistakenly attacks insulin-producing beta cells in the pancreas. With reduced insulin in the bloodstream, the body has trouble converting glucose into energy for cells, requiring patients to manually administer insulin as needed.
But for the new study, researchers at the University of Southern California and Seoul National University may have found a way to prevent this destruction. The key is a peptide called MOTS-c, which the team has previously shown can mimic the benefits of exercise and improve the fitness and overall health of older mice.
Interestingly, MOTS-c isn’t actually encoded by the main genome in our cells. Instead it’s produced in the mitochondria, organelles that produce energy for cells and contain their own separate genome.
For the new study, the researchers engineered mice to develop type 1 diabetes, then treated them with injections of MOTS-c. And sure enough, the treatment prevented the destruction of the animals’ beta cells, and kept the mice from developing hyperglycemia.
MOTS-c seems to work by supporting regulatory T cells, those tasked with recognizing the difference between the body’s own cells and foreign pathogens. That reduces the amount of killer T cells that are activated to attack the insulin-producing cells.
“We are able to prevent the onset of type 1 diabetes in mouse models,” says Changhan David Lee, co-corresponding author of the study. “MOTS-c injections seem to tame the immune system and to tell them not to tackle their own cells.”
While it’s still early days for the treatment, there are promising signs that the results might carry across to humans. The team found that patients with type 1 diabetes had far lower levels of MOTS-c circulating in their blood than non-diabetics. In a follow-up test on human cells in culture, MOTS-c treatments reduced the activation of killer T cells, the same as it had in mice. The researchers also say that the technique could potentially be adapted to treat other autoimmune diseases besides type 1 diabetes.
The research was published in the journal Cell Reports.