Using ‘Google Maps’ to zoom in on the Islets of Langerhans

Researchers at the UMCG (University Medical Center Groningen) and LUMC (Leiden University Medical Center) have visualized the complete cell structure of the Islets of Langerhans in an animal model. This makes it possible to zoom in on even the smallest cell structures in a way not unlike Google Maps, without losing sight of the overall picture. The more than 25,000 microscopic images provide insight into the development of diabetes type 1 in rats. It is the first time that a human disease has been imaged in an animal model in this way. The study was published in Scientific Reports on 8 May 2013. The database is openly accessible via www.nanotomy.nl .

Islets of Langerhans are insulin-producing cells which are found in the pancreas. In people with diabetes type 1 the immune system mistakenly attacks these islets. The insulin-producing beta cells are largely destroyed as a result and can no longer produce any insulin. The exact cause remains unknown and patients become dependent on insulin injections.

To gain more insight into the development of diabetes type 1, complete islets were examined and analysed during the course of diabetes development in a rat model based on electron microscopy (EM) at the highest possible resolution. A special EM technique was developed for this.

The structure and morphology of cells can be revealed at very high resolution levels with today’s electron microscopes. One drawback, however, is that to do so it is necessary to zoom in on just part of a cell and you literally lose sight of the cell as a whole. The special preparation and imaging techniques make it possible to string the individual photos together in order to create a complete overview, while at the same time maintaining the huge magnification factor.

Nanotomy

The researchers have used this technique to reveal the nano-anatomy (or ‘nanotomy’) of the Islets of Langerhans in a rat during the various stages of diabetes type 1. This made it possible to zoom in on tissue, cells, cell organelles and macromolecules. The data reveal that minute virus-like particles (35 nanometres in diameter) are found in the beta cells of rats with diabetes. The researchers have shown, however, that this is an accumulation of glycogen which may be caused by the raised blood sugar in diabetes.

Researchers worldwide can now use the huge datasets created, accessed via nanotomy.nl, to analyse various aspects of the development of diabetes. A follow-up study using nanotomy on the Islets of Langerhans in human patients has also been started to gain a clearer understanding of the cause of diabetes type 1.