Langerhans Islets and Beta Cells

Beta cells produce and store insulin in the body. In type 1 diabetes as well as in the advanced stage of type 2 diabetes, the beta cells are destroyed. Insulin is no longer produced sufficiently. The aim of this research area is to stop the destruction of the beta cells or replace the beta cells.

To this end, the DZD researchers are investigating the formation, storage and release of the insulin vesicles in which the beta cells store the insulin. This forms the basis for the development of new prevention and therapeutic approaches for diabetes.

To date, human donor cells have been used for beta cell transplantation. DZD researchers want to gain beta cells from stem cells. An alternative is xenotransplantation, the transplantation of cells from another species. If beta cells are protected in a capsule, these can be transplanted without being destroyed by the immune system. © DZD

How could destroyed beta cells be replaced?
DZD researchers are also working on therapies to replace already destroyed beta cells. In addition to the transplantation of insulin-producing islet cells from human donors, animal tissues or stem cells could also serve as a source for transplants. New regenerative procedures rely on dormant reserves in the patient's body. Another alternative are "bioreactors", a kind of artificial pancreas.

Transplantation

In islet transplantation, the Langerhans islets are removed from the pancreas of an organ donor and processed in the laboratory. Then the “islets” are implanted in the recipient. However, this transplantation remains reserved for a small group of patients suffering from severe and often life-threatening complications, especially hypoglycemia. One reason for the rare application of this method is the necessary use of drugs which suppress the immune system of the recipient in order to prevent rejection of the cells.

Bioreactor: Artificial Pancreas

Instead of a donor organ, a palm-size “bioreactor” could take over the role of the pancreas in the body of diabetic patients. The reactor contains human islet cells that can measure the blood glucose level and produce insulin. The cells are surrounded by a special Teflon membrane, which allows hormones and nutrients to pass unimpeded, but prevents contact with the body's immune cells. Therefore, there is no need for drugs to suppress the immune system. This approximately 6 cm flat container can be implanted directly under the abdominal skin. It could be an alternative to the classical transplant in the near future and also be used for xenotransplantations - the transplantation of cells from another species

Beta Cells from Stem Cells

A new therapeutic approach is to gain beta cells from stem cells in the laboratory. The objective is to mobilize the self-healing powers in the pancreas of individuals with diabetes and to stimulate these to regenerate efficient beta cells from stem cells.

Publications

Identification of proliferative and mature β-cells in the islets of Langerhans., Nature. 2016 Jul 21;535(7612):430-4. doi: 10.1038/nature18624


The biomechanical properties of an epithelial tissue determine the location of its vasculature, Nature Communications 7, Article number: 13560 (2016) doi:10.1038/ncomms13560


Alterations in β-Cell Calcium Dynamics and Efficacy Outweigh Islet Mass Adaptation in Compensation of Insulin Resistance and Prediabetes Onset, Diabetes 2016 Sep; 65(9): 2676-2685. doi.org/10.2337/db15-1718


Aldehyde dehydrogenase activity is necessary for beta cell development a
nd functionality in mice, Diabetologia January 2016, Volume 59, Issue 1, pp 139–150, doi: 10.1007/s00125-015-3784-4


The F-actin modifier villin regulates insulin granule dynamics and exocytosis downstream of islet cell autoantigen 512, Molecular Metabolism Volume 5, Issue 8, August 2016, Pages 656–668, http://dx.doi.org/10.1016/j.molmet.2016.05.015