Type 1 Diabetes Cure

Diabetes type 1 is caused by the destruction of enough beta cells to produce symptoms; these cells, which are found in the Islets of Langerhans in the pancreas, produce and secrete insulin, the single hormone responsible for allowing glucose to enter from the blood into cells (in addition to the hormone amylin, another hormone required for glucose homeostasis). Hence, the phrase "curing diabetes type 1" means "causing a maintenance or restoration of the endogenous ability of the body to produce insulin in response to the level of blood glucose" and cooperative operation with counterregulatory hormones.

This section deals only with approaches for curing the underlying condition of diabetes type 1, by enabling the body to endogenously, ''in vivo'', produce insulin in response to the level of blood glucose. It does not cover other approaches, such as, for instance, closed-loop integrated glucometer/insulin pump products, which could potentially increase the quality-of-life for some who have diabetes type 1, and may by some be termed "artificial pancreas".

Reversion

Encapsulation approach

A biological approach to the artificial pancreas is to implant bioengineered tissue containing islet cells, which would secrete the amounts of insulin, amylin and glucagon needed in response to sensed glucose.

When islet cells have been transplanted via the Edmonton protocol, insulin production (and glycemic control) was restored, but at the expense of continued immunosuppression drugs. Encapsulation of the islet cells in a protective coating has been developed to block the immune response to transplanted cells, which relieves the burden of immunosuppression and benefits the longevity of the transplant.

One concept of the bio-artificial pancreas uses encapsulated islet cells to build an ''islet sheet'' which can be surgically implanted to function as an artificial pancreas.

This islet sheet design consists of:

An inner mesh of fibers to provide strength for the islet sheet;
Islet cells, encapsulated to avoid triggering a proliferating immune response, adhered to the mesh fibers;
A semi-permeable protective layer around the sheet, to allow the diffusion of nutrients and secreted hormones;
A protective coating, to prevent a foreign body response resulting in a fibrotic reaction which walls off the sheet and causes failure of the islet cells.

Islet sheet with encapsulation research is pressing forward with large animal studies at the present, with plans for human clinical trials within a few years.

Clinical studies underway in New Zealand by Living Cell Technologies have encapsulated pig islet cells in a seaweed derived capsule. This approach has had very positive clinical studies and is currently underway in human trials as of 2008. So far, treatment using this method of cell encapsulation has been proven safe and effective and is the first to achieve insulin independence in human trials without immunosuppressant drugs.

Islet cell regeneration approach

Research undertaken at the Massachusetts General Hospital between 2001 and 2003 demonstrated a protocol to reverse type 1 diabetes in non-obese diabetic mice (a frequently used animal model for type 1 diabetes mellitus). Three other institutions have had similar results, as published in the March 24, 2006 issue of ''Science''. A fourth study by the National Institutes of Health achieved similar results, and also sheds light on the biological mechanisms involved.

Other researchers, most notably Dr. Aaron I. Vinik of the Strelitz Diabetes Research Institute of Eastern Virginia Medical School and a former colleague, Dr. Lawrence Rosenberg (now at McGill University) discovered in a protein they refer to as INGAP, which stands for Islet Neogenesis Associated Protein back in 1997. INGAP seems to be the product of a gene responsible for regenerating the islets that make insulin and other important hormones in the pancreas.

INGAP has had commercialization difficulties. Although it has appeared promising, commercial rights have changed hands repeatedly, having once been owned by Procter & Gamble Pharmaceuticals, which eventually dropped it. Rights were then acquired by GMP Companies. More recently, Kinexum Metabolics, Inc. has since sublicensed INGAP from GMP for further clinical trials. Kinexum has continued development under Dr. G. Alexander Fleming, an experienced metabolic drug developer, who headed diabetes drug review at the FDA for over a decade. As of 2008, the protein had undergone Phase 2 Human Clinical Trials, and developers were analyzing the results. At the American Diabetes Association's 68th Annual Scientific Sessions in San Francisco, Kinexum announced a Phase 2 human clinical trial with a combination therapy, consisting of DiaKine's Lisofylline (LSF) and Kinexum's INGAP peptide, which is expected to begin in late 2008. The trial will be unique in that patients who are beyond the 'newly diagnosed' period will be included in the study. Most current trials seeking to treat people with type 1 diabetes do not include those with established disease.

Stem cells approach

Research is being done at several locations in which islet cells are developed from stem cells.

South Korea

In January 2006, a team of South Korean scientists has grown pancreatic beta cells, which can help treat diabetes, from stem cells taken from the umbilical cord blood of newborn babies.

Brazil

Stem cell research has also been suggested as a potential avenue for a cure since it may permit regrowth of Islet cells which are genetically part of the treated individual, thus perhaps eliminating the need for immuno-suppressants.This new method autologous nonmyeloablative hematopoietic stem cell transplantation was developed by a research team composed by Brazilian and American scientists (Dr. Julio Voltarelli, Dr. Carlos Eduardo Couri, Dr Richard Burt, and colleagues) and it was the first study to use stem cell therapy in human diabetes mellitus This was initially tested in mice and in 2007 there was the first publication of stem cell therapy to treat this form of diabetes. Until 2009, there was 23 patients included and followed for a mean period of 29.8 months (ranging from 7 to 58 months). In the trial, severe immunosuppression with high doses of cyclophosphamide and anti-thymocyte globulin is used with the aim of "turning off" the immunologic system", and then autologous hematopoietic stem cells are reinfused to regenerate a new one. In summary it is a kind of "immunologic reset" that blocks the autoimmune attack against residual pancreatic insulin-producing cells. Until December 2009, 12 patients remained continuously insulin-free for periods raging from 14 to 52 months and 8 patients became transiently insulin-free for periods ranging from 6 to 47 months. Of these last 8 patients, 2 became insulin-free again after the use of sitagliptin, a DPP-4 inhibitor approved only to treat type 2 diabetic patients and this is also the first study to document the use and complete insulin-independendce in humans with type 1 diabetes with this medication. In parallel with insulin suspension, indirect measures of endogenous insulin secretion revealed that it significantly increased in the whole group of patients, regardless the need of daily exogenous insulin use.

However, there were no control subjects, which means that all of the processes could have been completely or partially natural. Secondly, no theory for the mechanism of cure has been promoted. It is too early to say whether the results will be positive or negative in the long run.

University of North Carolina

In September 2008, scientists from the University of North Carolina at Chapel Hill School of Medicine have announced their success in transforming cells from human skin into cells that produce insulin.

The skin cells were first transformed into stem cells and then had been differentiated into insulin-secreting cells.

However, other scientists have doubts, as the research papers fail to detail the new cells' glucose responsiveness and the amount of insulin they are capable of producing.

Gene therapy approach

Designing a viral vector to deliberately infect cells with DNA to carry on the viral production of insulin in response to the blood sugar level.]

Technology for gene therapy is advancing rapidly such that there are multiple pathways possible to support endocrine function, with potential to practically cure diabetes.

Gene therapy can be used to manufacture insulin directly: an oral medication, consisting of viral vectors containing the insulin sequence, is digested and delivers its genes to the upper intestines. Those intestinal cells will then behave like any viral infected cell, and will reproduce the insulin protein. The virus can be controlled to infect only the cells which respond to the presence of glucose, such that insulin is produced only in the presence of high glucose levels. Due to the limited numbers of vectors delivered, very few intestinal cells would actually be impacted and would die off naturally in a few days. Therefore by varying the amount of oral medication used, the amount of insulin created by gene therapy can be increased or decreased as needed. As the insulin producing intestinal cells die off, they are boosted by additional oral medications.
Gene therapy might eventually be used to cure the cause of beta cell destruction, thereby curing the new diabetes patient before the beta cell destruction is complete and irreversible.
Gene therapy can be used to turn duodenum cells and duodenum adult stem cells into beta cells which produce insulin and amylin naturally. By delivering beta cell DNA to the intestine cells in the duodenum, a few intestine cells will turn into beta cells, and subsequently adult stem cells will develop into beta cells. This makes the supply of beta cells in the duodenum self replenishing, and the beta cells will produce insulin in proportional response to carbohydrates consumed.

Yonsei University

Scientists in the South Korean university of Yonsei have, in 2000, succeeded in reversing diabetes in mice and rats. Using a viral vector, a DNA encoding the production of an insulin analog was injected to the animals, which remained non-diabetic for at least the eight months duration of the study.