Whilst the diabetes epidemic is constantly growing scientists are looking for new treatment paths. Amongst them the grafting of beta cells, the cells which produce insulin within the pancreas, is a promising area. Bernard Peers, Marianne Voz and their colleagues are trying to shed light on the differentiation mechanisms of these cells in order to be able to reproduce them more easily from stem cells.

Situated behind the stomach, in front of and above the kidneys, the pancreas is a digestive gland linked to the duodenum (the initial section of small intestine). Both exocrinic and endocrinic, this gland synthesises secretion products, certain of which are freed into the digestive tract whilst others enter the blood stream. Amongst the substances which spring from the endocrinic pancreas is numbered notably insulin, known to be lacking in patients affected by type 1 diabetes. ‘Type 1 diabetes is an autoimmune disease,’ explains Bernard Peers, who heads the research group on the development of the pancreas within the GIGA’s research unit, Development, stem cells and regenerative medicine. ‘In diabetic people, the immune system attacks the beta cells which produce insulin within the pancreas and destroys them,’ he continues. If the current treatment of type 1 diabetes – which consists of injecting insulin into the patient before meals – allows the patient to survive, this therapy is not optimal. In effect, ‘insulin injections do not allow for a very exact control of glycaemia and the patients frequently go through phases of hyperglycemia and hypoglycaemia. Over the long term, that could lead to complications,’ points out the FNRS research associate. Practically every part of the body could be subject to the side-effects of a badly controlled diabetes: the heart, the blood vessels, the kidneys, the eyes, the nervous system, etc. Finding new remedies against this disease which has been developing in an epidemic manner for a few decades now – the World Health Organisation estimates that the number of diabetics on the planet could reach 300 million by the year 2025 – thus represents a real public health issue.

One of the pathways followed by scientists to respond to this issue is the grafting of beta cells. The transplanting into diabetic patients of pancreatic cells taken from donors who have died is already practiced but the patient has to take powerful immunosuppressants in order to prevent the immune system from attacking these new beta cells, grafted into the pancreas. ‘This grafting allows for a temporary remission,’ indicates Marianne Voz, a FNRS research associate at the GIGA’s’ Biology and Molecular Genetics research unit. ‘But a major problem of this therapy is the largely insufficient availability of pancreatic endocrine cells from donors. Nevertheless it is now possible to generate stem cells on the basis of the patients’ ‘mature’ differentiated cells. And from these totipotent cells, called iPS, we can thus try to recreate beta cells in order to graft them onto a diabetic patient,’ continues Marianne Voz. In order to be able to generate pancreatic cells from stem cells it is important to carry out both research into the regulatory factors and the genetic determinants which control the differentiation of pancreatic cells, but also basic research into the development of the pancreas in a more general manner. In effect, only deeper knowledge of the molecular mechanisms involved in the development of this organ could bring about an optimisation of current treatments and nose out new therapeutic pathways. And that is what Bernard Peers, Marianne Voz and their colleagues in the study group on pancreatic development are currently working on.