Innovative live imaging of the pancreas
Some of the life style-related risk factors for the development of diabetes mellitus are well known, such as obesity in the case of type 2 diabetes (T2D). However, the precise underlying mechanisms leading to the decrease in beta cell mass responsible for the development of impaired glucose tolerance and diabetes still remain to be elucidated. Therefore, sensitive, specific and non-invasive methods for a comprehensive structural and functional characterisation of living pancreatic beta cells in vivo are urgently required. This would significantly enhance our understanding of the pathophysiology of both type 1 and type 2 diabetes. The key objective of the EU-funded 'Use of innovative strategies for beta-cell imaging in diabetes mellitus' (Betaimage) project is to develop new approaches for in vitro and in vivo beta cell imaging with a focus on beta cell mass. Given that beta cells contribute only marginally to the total mass of the pancreas and are scattered in tiny clusters known as the islets of Langerhans, a highly sensitive method for clinical imaging is required. To this end, the consortium plans to use the imaging technology of positron emission tomography / single-photon emission computed tomography (PET / SPECT) for visualisation of beta cells in humans with a novel tracer. So far, several potential beta cell-specific targets have been identified and specific ligands are under development. Successful in vivo determination of the pancreatic beta cell mass with a lead compound has been achieved and the acquisition and reconstruction protocols have been optimised in rodent models. Innovative strategies including the construction of differentially labelled molecules targeting novel surface beta cell antigens are also being explored and could increase the number of potential PET applications in beta cell imaging. The Betaimage approach for live imaging of pancreatic beta cells could be utilised not only to advance our understanding of the pathophysiology of diabetes but also to assess novel therapeutic approaches including cell replacement therapies. It is envisaged to become a great asset for diabetes research, aiding the development of novel anti-diabetic agents.
