A brand new examine from MIT means that consuming meals wealthy within the amino acid cysteine may assist the small gut renew and restore itself. Researchers discovered that cysteine can activate an immune signaling course of that encourages stem cells to develop new intestinal tissue.
This enhanced means to regenerate may assist the physique heal injury attributable to radiation, which is a standard aspect impact of most cancers remedies. Though the examine was carried out in mice, scientists say that if comparable outcomes are seen in people, cysteine from meals or dietary supplements may supply a brand new approach to assist the gut recuperate sooner after harm.
“The examine means that if we give these sufferers a cysteine-rich weight-reduction plan or cysteine supplementation, maybe we are able to dampen among the chemotherapy or radiation-induced harm,” 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.”
Earlier research have proven that particular sorts of diets, together with calorie restriction, can improve the operate of intestinal stem cells. Nevertheless, this analysis is the primary to pinpoint a single nutrient that immediately boosts the intestine’s regenerative capability.
Yilmaz is the senior writer of the examine, which was just lately revealed in Nature. The paper’s lead writer is Koch Institute postdoctoral researcher Fangtao Chi.
Weight loss plan and Regeneration
It’s well-known that weight-reduction plan performs a significant function in well being. Excessive-fat diets can contribute to weight problems, diabetes, and different continual circumstances, whereas low-calorie diets have been linked to longer lifespans in lots of species. Yilmaz’s lab has lengthy studied how completely different dietary patterns affect stem cell regeneration and has beforehand proven that each high-fat diets and short-term fasting can enhance stem cell exercise in distinct methods.
“We all know that macro diets resembling high-sugar diets, high-fat diets, and low-calorie diets have a transparent influence on well being. However on the granular degree, we all know a lot much less about how particular person vitamins influence stem cell destiny selections, in addition to tissue operate and total tissue well being,” Yilmaz says.
Of their newest work, the MIT workforce fed mice diets excessive in one in all 20 amino acids, that are the constructing blocks of proteins. They then analyzed how every amino acid affected stem cell development within the gut. Cysteine produced the strongest influence, tremendously growing each stem cells and progenitor cells (immature cells that become grownup intestinal cells).
Additional experiments revealed that cysteine units off a sequence response that prompts immune cells often known as CD8 T cells. When intestinal cells take up cysteine from meals, they convert it into CoA, a cofactor that strikes into the mucosal lining of the gut. There, CD8 T cells take up CoA, which triggers them to multiply and launch a signaling molecule referred to as IL-22.
IL-22 performs a key function in regulating intestinal stem cell regeneration, however till now, scientists didn’t know that CD8 T cells may produce it. As soon as activated, these IL-22-releasing T cells assist shield and restore the intestinal lining each time it’s injured.
“What’s actually thrilling right here is that feeding mice a cysteine-rich weight-reduction plan results in the enlargement of an immune cell inhabitants that we usually do not affiliate with IL-22 manufacturing and the regulation of intestinal stemness,” Yilmaz says. “What occurs in a cysteine-rich weight-reduction plan is that the pool of cells that make IL-22 will increase, significantly the CD8 T-cell fraction.”
These T cells are likely to cluster within the intestinal lining, inserting them in the proper location to reply shortly to break. The researchers noticed that the activation of CD8 T cells occurred primarily within the small gut, not elsewhere within the digestive tract, possible as a result of most dietary protein is absorbed there.
Repairing Radiation and Chemotherapy Harm
Within the examine, mice on a cysteine-rich weight-reduction plan confirmed improved restore of radiation injury to the intestinal lining. In further, unpublished work, the workforce discovered that the identical weight-reduction plan helped regeneration after therapy with 5-fluorouracil, a chemotherapy drug generally used for colon and pancreatic cancers that may additionally hurt intestinal tissue.
Cysteine happens naturally in lots of protein-rich meals, together with meat, dairy, legumes, and nuts. The physique also can make cysteine by changing one other amino acid, methionine, within the liver. Nevertheless, the cysteine produced internally circulates all through the physique relatively than concentrating within the gut the best way dietary cysteine does.
“With our high-cysteine weight-reduction plan, the intestine is the primary place that sees a excessive quantity of cysteine,” Chi says.
Past Antioxidants
Cysteine has lengthy been identified for its antioxidant properties, however this examine is the primary to point out that it additionally helps intestinal stem cells regenerate. The researchers at the moment are exploring whether or not cysteine can stimulate regeneration in different tissues as nicely. One ongoing challenge is testing whether or not cysteine can promote hair follicle regrowth.
In addition they plan to proceed investigating different amino acids that will affect stem cell renewal and intestine well being.
“I believe we will uncover a number of new mechanisms for a way these amino acids regulate cell destiny selections and intestine well being within the small gut and colon,” Yilmaz says.
This analysis was supported 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 Growing older Analysis, the MIT Stem Cell Initiative, and the Koch Institute Assist (core) Grant from the Nationwide Most cancers Institute.
