Scientists have grown innervated intestinal tissues

Julia Korowski, XX2 century

Scientists at the Cincinnati Children's Hospital Medical Center have grown intestinal tissues with functioning nerves and successfully implanted them in laboratory animals. The results of the study are published in the journal Nature Medicine.

Researchers have recreated human tissues using pluripotent stem cells – immature undifferentiated cells that can transform into cells of any organs. "One day this technology will allow us to grow a part of a healthy intestine for transplantation to a patient, but the fact that we can already use it in experiments and to answer a lot of questions will bring great benefits to people's health," says one of the authors of the work Michael Helmrath in a press release by Scientists Tissue Engineer Human Intestines and Functioning Nerves.

Thanks to the new methods, scientists will be able to study intestinal disorders using functional tissue as an example and test the effect of drugs on an artificial organ before starting clinical trials on humans. "Many oral medications cause diarrhea and colic and disrupt intestinal motility," explains one of the leaders of the study, Professor Jim Wells (Jim Wells). "The primary goal of this technology, which will help a huge number of people, is the first stage of screening of new drugs, which will identify non–target toxicity and prevent adverse intestinal reactions."

In 2010, Wells and his research team grew the first generation of three-dimensional intestinal tissues in the laboratory and published the results in the journal Nature. This time, scientists used similar methods. They placed human pluripotent stem cells in a Petri dish, where, under the influence of a special solution, they began to form intestinal tissue. Six years ago, our colleagues received tissue without a nervous system – and yet, it is she who is responsible for moving through the digestive tract and assimilation of nutrients. If the nerves do not work properly, the intestinal muscles cannot contract normally. As a result, there are pains, diarrhea, constipation, and in particularly severe cases – functional blockade, which requires surgical intervention.

To create a nervous system, scientists placed neural crest cells in another Petri dish, which formed the precursors of nerves. The most difficult task was to determine how and when to include neural crest cells in the developing intestine. "We tried several different approaches, most of which were based on the hypothesis that if you mix the right cells in a Petri dish at the right time, they will figure out what to do next. It was a gamble, but it worked," Wells says. A successful mixture caused the precursors of nerve cells and tissues to fuse together – in much the same way as it happens in the intestines of an embryo.

To test how successfully the new tissues would grow and function, they were transplanted into a laboratory mouse. Experiments have shown that the new intestine really works and, moreover, its structure strongly resembles a human one. The tissues actively grew, absorbed nutrients and demonstrated peristalsis – a wave-like muscle contraction that promotes food in the gastrointestinal tract. With the help of their new brainchild, the scientific group studied the development of a rare form of Hirschsprung's disease – an anomaly in which the nervous system is not formed in the intestine, and processed food accumulates. It is known that the severe form of the disease is caused by a mutation in the PHOX2B gene. Tests in a Petri dish and on mice have shown that mutations in this part of the genome cause harmful changes in innervated tissues.

Researchers believe that artificially grown intestines will open up new opportunities for scientists. It will allow you to study healthy nutrition, diabetes mellitus, complex gastrointestinal diseases, as well as changes in biochemistry caused by gastric bypass surgery.

Portal "Eternal youth" http://vechnayamolodost.ru  22.11.2016