US – Tens of millions of people worldwide suffer from type 1 diabetes, in which the pancreatic cells responsible for producing insulin are missing or inactive.  Insulin is secreted by the pancreas when blood sugar is high (for example, after we ate a hearty meal) and cell signaling in adipose tissue, liver and muscles absorb glucose from the blood. Diabetics must inject insulin from an external source to maintain a normal blood sugar level.

US researchers now report that they were able to grow human cells in the laboratory and transplant them in mice to produce insulin.  In the future, the hope is those cells will be implanted in patients and fired them daily injections.

Researchers from around the world have been working for years to develop insulin-producing cells in the laboratory. To do this, they try to “force” these cells to develop into cells.  Each of us began life as an embryo consisting of stem cells, each of which can develop into any type of cell in the body.

Today, scientists can take adult cells, such as skin cells, and bring them back into a stem cell.  Researchers were also able to make these cells develop into pancreatic beta-cells – insulin-producing cells.

But here they encountered a problem

Laboratory-grown cells looked like beta cells, and had fairly similar characteristics as beta cells with one important difference – they did not secrete insulin in response to sugar.  In fact, they behaved like embryonic beta cells still are not doing their job in regulating blood sugar levels.  Attempts to cause the cells to “grow up” and secrete insulin have failed repeatedly.

To tackle the problem, Ronald Evans, of the Salk Institute in California, took an unconventional approach. He examined the proteins that are found in large quantities in mature beta cells, and are not embryonic stem cells and cells produced in the laboratory, even if they have no direct connection to manufacturing insulin.  Evans and his colleagues found high level adult cells of a protein called EER related metabolic processes – metabolism and energy production.

This protein is found in large amounts in cells that consume a lot of energy, such as neurons and muscle cells, but until recently did not suspect it is also important in the production of insulin. In a paper published in the journal Cell Metabolism, the researchers showed that mice beta cells in their did not produce the protein EER not secreted insulin Diabetes, which demonstrated the vitality of this process.

The next step was to make beta cells produced in the laboratory to produce large amounts of protein.  To do this, the researchers infected cells with genetically engineered virus instilled to the protein Gene EER.

Infected beta cells began producing the proteins, and subsequently also secrete insulin in response to sugar.  It turns out that this one protein, unrelated to the creative process and the provision of insulin is the key for turning adult cells into beta cells.  Apparently, the protein necessary for cell due to the high energy demands of producing a large amount of insulin.

Promise for the future

The researchers implanted the beta cells in mice with type 1 diabetes. Within a few days it began to produce insulin and actually cure them of diabetes. Two months after transplantation, the cells still function and produce insulin.  Sugar levels of the mice were normal, and even up and down during a typical day for a healthy life.

This study is particularly promising because the insulin-producing cells are human cells in the laboratory that have become beta cells.  In the future it will be possible to produce them “on demand” – to take a few cells in a diabetic person, to make them functional beta cells and re-implanting them in the patient.

As these are cells from the individual himself not donor, graft rejection rate is very low, and the patient would not have to get drugs suppress the immune system.

If and when this research passes the clinical trials, it will likely bring a real revolution in the treatment of patients with diabetes. It will no longer be a chronic treatment with insulin for life, but cure the disease once and for all.

1 comment