MIT researchers have found {that a} naturally occurring amino acid discovered in lots of protein-rich meals could assist the gut restore itself after injury. In a brand new examine, scientists discovered that cysteine can activate an immune response that enhances intestinal stem cells and helps regenerate tissue within the small gut.
The findings, which had been noticed in mice, may finally result in new methods to scale back intestinal injury brought on by radiation remedy and chemotherapy. Researchers say cysteine-rich diets or dietary supplements may in the future assist most cancers sufferers get better extra shortly from treatment-related accidents.
“The examine means that if we give these sufferers a cysteine-rich eating regimen or cysteine supplementation, maybe we will dampen a few of the chemotherapy or radiation-induced damage,” says Omer Yilmaz, director of the MIT Stem Cell Initiative, an affiliate professor of biology at MIT, and a member of MIT’s Koch Institute for Integrative Most cancers Analysis. “The sweetness right here is we’re not utilizing an artificial molecule; we’re exploiting a pure dietary compound.”
The examine, printed in Nature, is the primary to determine a single nutrient able to straight enhancing intestinal stem cell regeneration. Earlier analysis had proven that broader dietary patterns, equivalent to fasting or calorie restriction, can affect stem cell exercise, however scientists had not pinpointed one particular nutrient accountable for any such restore response.
How Cysteine Prompts Intestine Restore
Yilmaz and his staff needed to raised perceive how particular person vitamins have an effect on stem cells and tissue well being. To research, the researchers fed mice diets enriched with one in every of 20 completely different amino acids, that are the constructing blocks of proteins. They then measured how every amino acid influenced regeneration in intestinal stem cells.
Amongst all of the amino acids examined, cysteine produced the strongest regenerative impact on each stem cells and progenitor cells, which finally mature into grownup intestinal cells.
The researchers later uncovered the organic chain response behind the impact. When intestinal cells take up cysteine from meals, they convert it right into a molecule referred to as CoA. That molecule is then launched into the intestinal lining, the place it’s absorbed by immune cells often called CD8 T cells.
As soon as activated, these T cells start multiplying and producing IL-22, a signaling protein referred to as a cytokine that performs a serious position in intestinal restore and stem cell regeneration.
Till now, scientists didn’t know that CD8 T cells may produce IL-22 in a manner that helps intestinal stem cells.
“What’s actually thrilling right here is that feeding mice a cysteine-rich eating regimen results in the enlargement of an immune cell inhabitants that we sometimes do not affiliate with IL-22 manufacturing and the regulation of intestinal stemness,” Yilmaz says. “What occurs in a cysteine-rich eating regimen is that the pool of cells that make IL-22 will increase, significantly the CD8 T-cell fraction.”
Immune Cells Positioned for Speedy Therapeutic
The researchers discovered that these activated T cells collect within the lining of the small gut, putting them in an excellent place to reply shortly when injury happens. The impact was largely restricted to the small gut as a result of that’s the place most dietary protein is absorbed.
Within the examine, mice fed a cysteine-rich eating regimen confirmed improved restoration from radiation-related intestinal injury. The staff additionally reviews that unpublished experiments discovered comparable regenerative advantages after therapy with the chemotherapy drug 5-fluorouracil, which is often used towards colon and pancreatic cancers however also can injure the intestinal lining.
Meals Wealthy in Cysteine
Cysteine happens naturally in lots of high-protein meals, together with meat, dairy merchandise, legumes, and nuts. The human physique also can produce cysteine by itself by changing one other amino acid referred to as methionine within the liver.
Nonetheless, researchers say dietary cysteine seems to have a stronger impact on the gut as a result of it reaches the intestine straight earlier than being distributed all through the physique.
“With our high-cysteine eating regimen, the intestine is the primary place that sees a excessive quantity of cysteine,” Chi says.
Cysteine has lengthy been identified for its antioxidant properties, however that is the primary examine displaying that it might probably straight stimulate intestinal stem cell regeneration.
Future Analysis on Regeneration
The MIT staff is now exploring whether or not cysteine may help regeneration in different tissues. One ongoing venture is analyzing whether or not the amino acid can stimulate hair follicle restore and regrowth.
Researchers are additionally persevering with to research the consequences of different amino acids that confirmed indicators of influencing stem cell conduct.
“I feel we’ll uncover a number of new mechanisms for the way these amino acids regulate cell destiny selections and intestine well being within the small gut and colon,” Yilmaz says.
The analysis was supported partly by the Nationwide Institutes of Well being, the V Basis, the Kathy and Curt Marble Most cancers Analysis Award, the Koch Institute-Dana-Farber/Harvard Most cancers Heart Bridge Venture, the American Federation for Ageing Analysis, the MIT Stem Cell Initiative, and the Koch Institute Assist (core) Grant from the Nationwide Most cancers Institute.
