PHILADELPHIA, PENNSYLVANIA -Men with type 1 diabetes may someday be able to use stem cells that become sperm to replace their producing cells of the pancreas insulin. These grafts would eliminate the need for frequent daily injections of insulin to control blood sugar.
Type 1 diabetes occurs when the immune system attacks and destroys insulin-producing cells in the pancreas. Without insulin to help cells absorb blood sugar, a person can not use the energy from food. Type 1 diabetes is untreated always fatal, but insulin injections and regular monitoring of blood glucose can help patients to have a relatively normal life.
Sometimes insulin injections are not enough to keep type 1 diabetes in check, however. So in the late 190s, researchers at the University of Alberta in Canada have begun transplanting cells corpses of islets in diabetic. It is not an ideal solution, but, as a beneficiary must remain on immunosuppressive drugs for the rest of their lives to prevent transplant rejection and usually will need more insulin injections.
cell biologist G. Ian Gallicano strains of Georgetown University in Washington, DC, and colleagues believe they have found a method that would give diabetics the benefits of transplantation of islet cells without need immunosuppressive drugs. Millions of sperm cells are created every day from stem cells in the testes spermatogonial cells called stem cells (SSCs). The researchers harvested from human testicular tissue SSCs and designed to become pluripotent stem cells, which have the ability to specialize in any type of cell, a process that took 2 weeks. Next, the researchers pushed the stem cells to develop into cells of the pancreatic islets.
As they reported yesterday at the annual meeting of the American Society for Cell Biology, Gallicano and colleagues transplanted human islet cells designed in diabetic mice that do not have an immune system and therefore can not attack the inserted cells. Transplants lowered high blood mice glucose levels, a good sign that the cells would do the same in humans.
Gallicano warns, however, that the technique is not ready for people just yet. "We do not get enough insulin of each cell to cure diabetes in humans."
This is a concern shared by Sheng Ding, a biochemist at the Scripps Research Institute in San Diego, California, who was not involved in the research. Before the technology is ready for the clinic, he said, researchers need to increase the production of insulin in the transplanted cells. However, Ding said: "This is a direction to continue to finally cure for type 1 diabetes"
This is not the first attempt to treat or cure diabetes with stem cells Researchers had. already used the cells of the skin or other tissue to create a slightly different type of stem cells, called induced pluripotent stem (iPS) cell, which may then proceed to replace cells damaged islets. using cells iPS has some advantages, said Gallicano. they do not require an invasive procedure to obtain, and they work for both sexes. However, researchers need to add four genes morph cells into iPS cells. genes are not yet insert the right place, which could cause cancer or cell death, he said.
the human SSCs, though, men only, are already stem cells and do not need those four genes enabled. "We must not do anything to make them pluripotent except out of their niche" in the testicles, said Gallicano.
Researchers hope they can find a method that would benefit both diabetic women . Gallicano says he sees no reason why the precursor stem cell eggs can not be used. one major difference is that the egg stem cells have only one copy of each gene, while the CSP have two copies, like other cells in the body, making it easier to apply the SSC technique.
There is another obstacle, said Gallicano, which is whether the immune system, which already created antibodies against islet cells of the body will attack the transplanted cells as well.
0 Komentar