Diabetes mellitus refers to a range of metabolic disorders characterized by high levels of glucose in the bloodstream, due to either impaired production of insulin by the pancreas or resistance to the effects of insulin in the body. Stem cells are normal body cells that can develop into a variety of other cell types in order to replenish the body’s supply of specialized cells as the need arises. Researchers collect adult stem cells from bone marrow and cord blood or embryonic stem cells from human embryos. When used to treat diabetes, stem cells may help restore insulin production in the pancreas, increase the body’s sensitivity to insulin, and control many of the consequential complications of uncontrolled high blood glucose levels, such as heart disease, kidney failure, and peripheral neuropathy. Stem cell treatment for diabetes works by repairing damaged tissues in the pancreas, kidney and blood vessels, and by inhibiting inflammatory chemicals that contribute to insulin resistance.
Stem cells stimulate regeneration and proliferation of the pancreatic beta cells. When they encounter areas of pancreas damage, they can develop and mature into new pancreas cells. Additionally, they release growth factors that stimulate progenitor pancreas cells to begin multiplying to fill in and repair areas of damage. Regeneration of the pancreas leads to restoration of the body’s normal insulin production. In a clinical study in Argentina, using this treatment for insulin-requiring diabetic patients enabled about 85% of those patients to stop their insulin injections.
Insulin normally binds to insulin receptor molecules on the surface of cells to induce those cells to take up glucose from the blood. Adipose, or fatty tissue, produces pro-inflammatory compounds, called cytokines, that bind to insulin receptors, making the affected cells incapable of responding to insulin. As this insulin resistance causes blood sugar levels to rise, the pancreatic beta cells increase their production of insulin until they begin to wear out prematurely and die. Stem cells have a significant capacity to prevent the manufacture of the cytokines by producing inhibitor compounds, such as interleukin-10. By blocking the production of pro-inflammatory chemicals, stem cells allow the insulin receptors to retain their ability to bind to insulin.
Additionally, stem cells are able to replace damaged endothelial cells that line the inside walls of blood vessels. They respond to chemical signals released by injured body organs by migrating to the areas of damage and transforming into the appropriate cell to replace those that have died. Furthermore, in cases of chronic pain from damage to peripheral nerves, stem cell treatment induces and speeds the healing of the nerves and may reduce the amount of pain that patients experience. A typical stem cell treatment for diabetes involves the administration of several million stem cells every other day over the course of a week.