Be careful about stem cell therapy

A single part may contain more than one type of adult stem cell - exploring complicating the prospect of using stem cells to replace damaged tissue to cure diseases, according to a new study. Laboratory of geneticist Mario Capecchi, Nobel laureate.

In the June 8 issue of Nature Genetics, Professor Capecchi and geneticist Eugenio Sangiorgi wrote that, when they used a gene called Bmil to mark the presence of adult stem cells in the rat's gut, They were surprised to discover that these specific cells are mostly in the upper intestine of the mouse intestine.

This implies that at least one or two other types of adult stem cells must exist to maintain and repair the middle intestine and lower intestine segment of the mouse. The small intestine in mice is nearly 12 inches long if stretched out.

Adult stem cells are 'undifferentiated' cells that can become any type of cell in the area in which they are found. Medical researchers hope to transplant adult stem cells to treat various diseases. For example, replacing adult stem cells in the pancreas to replace damaged insulin-producing cells, in the heart to replace heart muscle cells that die from heart disease, and in the brain to replace production cells dopamine is damaged in patients with Parkinson's disease.

This new discovery is important because people are talking about stem cell therapy; They want to rely on stem cells to treat illness, Professor Capecchi, 2007 Nobel laureate in physiology.

'People always think of a homogeneous stem cell population in every organ, but now there are many stem cell populations in a given organ, so if you're going to use therapy, you have to realize This complexity, ' Professor Capecchi said.

If more than one type of adult stem cell is needed to form the intestinal wall, it is not surprising that this is also true for other organs.

Adult stem cells are seen as an alternative to embryonic stem cells, cells are capable of becoming any type of cell in the body - not just in a given organ - and okay taken from the remaining in vitro fertilization of couples trying to have children. Embryonic stem cells are a controversial issue because those who oppose abortion regard human embryonic stem cells as human rather than a small cell.

Professor Capecchi won the Nobel Prize with Sir Martin Evans and Oliver Smithies for developing gen targeting technology, a method of using embryonic stem cells to 'knock down' genes in mice, and then observe problems. What happens to determine any normal gene function.

(Photo by Eugenio Sangiorgi, University of Utah)

The magnified image of the mouse intestine, with the upper end of the intestine on the left and the lower end of the mouse on the right.Adult stem cells, marked with blue dye attached to a gene called Bmi1, function to create and maintain other types of cells that line the intestine.It is clear that adult stem cells are very common in the upper left intestine and less in the middle and lower intestine, in the middle and right of the image.This suggests that there may be more than one type of adult stem cell active in the intestine and perhaps even in other organs, complicating efforts to use stem cells to treat the disease, according to one study. rescue of Utal University.

Research on intestinal stem cells

Intestinal stem cells are one of the most carefully studied cells. They are needed to produce new cells for the intestinal wall when old cells wear out every two to five days.

Adult stem cells produce different cells in the intestine: cells to absorb food; cells to secrete mucus that make the intestine walls smooth and protect it; cells participate in protecting organisms against bacteria and other disease-causing organisms; and cells produce substances that are involved in communication between cells.

'Adult stem cells are a giant black box,' commented Sangiogri science doctor.

Other discoveries about adult stem cells

Two Sangiorgi and Capecchi scientists took beta catenin - a gene product commonly found in colon cancer and digestion - and activated it in adult stem cells from the intestinal wall.'Tumors grow very fast. That proves that stem cells are important in the formation of cancer, ' said Capecchi. Sangiorgi, a science doctor, said: 'Is cancer derived from stem cells? In some cases yes, and in some cases not. '

The two geneticists found that their adult stem cells marked with the Bmi1 gene were different from adult stem cells studied by Dutch scientists marked with the Lgr5 gene. The difference is their position in crypt. Stem cells divide in crypt, producing progenitor cells, cells that become intestinal cells.

There was a debate about where adult intestinal stem cells were found. Utal geneticists have discovered that Bmi1-marked adult stem cells slowly divide near the top of the crypt. The Dutch researchers found that their Lgr5-marked cells divide more quickly below the crypt, mixing Paneth cells, the cells produce enzymes that kill bacteria.

But Professor Capecchi does not see the contradiction here: 'Both of us may be right. Maybe we are studying at different stages in the life of stem cells, ' with cells marked with Bmi1 at an earlier stage and other gene-marked cells at a later stage.

"It shows that stem cell biology may be more complex than we think, and they can move from one state to another," he said, " and also moving between cryptes." 'They are still stem cells but at different stages in the life cycle.'