A new imaging method for further developing studies of insulin-producing cells in diabetes, among other uses, is now being presented by a group of researchers at Umeň University, in the form of a video in the first biomedical video journal, Journal of Visualized Experiments.
Figure 1. Near-infrared optical projection tomography enables the visualization of several cell types in large preparations. The image of a pancreas from a mouse with type-1 diabetes shows the insulin-producing islets of Langerhans in blue, blood vessels in red, and infiltrating autoimmune cells that break down the insulin-producing cells in green.
Larger image resolution
The newly developed technology is the reason why the research team recently received a SEK 4.3 million grant from the EU in a so-called Marie Curie program to link together the leading research teams in Europe in the field of diabetes imaging.
Ulf Ahlgren and his associates at the Umeň Center for Molecular Medicine, UCMM, have subsequently elaborated the technology for biomedical imaging with so-called optical projection tomography (OPT). Initially the method could only be used on extremely small preparations, but five years ago the Umeň scientists were able to adapt the technology to study whole organs, including the pancreas, from adult mice. The present findings describe a further development of OPT technology by going from ordinary visible light to the area near-infrared light. This is light with longer wavelengths that can more easily penetrate tissue. Thereby, and with some technical improvements, considerably larger samples can be studied, like rat pancreases. In other words, these are organs up to six times larger than in the past, which is important, because rats as laboratory animals are thought to be physiologically more similar to humans.
This adaptation to the area near-infrared light also means that the researchers will have access to a broader range of the light spectrum, making it possible to study more cell types in one and the same preparation. In the article the scientists exemplify the possibility of simultaneously tracing the insulin-producing islets of Langerhans, the autoimmune infiltrating cells, and the distribution of blood vessels in a model system for type-1 diabetes.
Internationally, huge resources are being committed to the development of imaging methods for studying the number of remaining insulin cells in patients with developing diabetes. Such methods would be of great importance in treatment, as only indirect methods for this exist today. However, a major problem in this connection is finding suitable contrast agents that specifically bind to insulin cells in the pancreas. The Umeň researchers’ OPT technology can play a major role here because it makes it possible to evaluate new contrast agents in the pancreas and also to calibrate the results from magnetic resonance imaging (MRI), for example. This is now going to be tested in the newly launched Marie Curie project "European Training Network for Excellence in Molecular Imaging in Diabetes," which links together five major EU-funded research consortia with different cutting-edge competences in the field.
The Umeň scientists’ study is presented in Journal of Visualized Experiments, which is the first scientific journal to offer the video format for publication in the life sciences. Visualization in video presentations clearly facilitates the understanding and description of complex experimental technologies. It can help address two major challenges facing bioscience research: the low transparency and poor reproducibility of biological experiments and the large amounts of time and work needed to learn new experimental technologies.
Other authors of the article are Christoffer Svensson, Anna Eriksson, Abbas Cheddad, Andreas H÷rnblad, Maria Eriksson, Nils Norlin, Elena Kostromina, and Tomas Alanentalo, all at UCMM; Fredrik Georgsson at the Department of Computer Science; all with Umeň University, along with Antonello Pileggi, Miami University, Florida, and James Sharpe at CRG, Barcelona, Spain.