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Glucose-dependent activity and emerging communities within beta cell populations in mouse pancreas tissue slices

2016-09-20

Dr. Jurij Dolenšek,
Institute of Physiology, Faculty of Medicine, University of Maribor, Slovenia
Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden

Thursday, September 22, 2016, 10.15-11.45, in BMC A7:114


Glucose is a major secretagogue for insulin secretion from pancreatic beta cells and has been a subject of extensive study for several decades. However, the information on glucose dependence of the activation, activity, and deactivation phases of beta cell responses is scarce. We utilized confocal calcium imaging in acute mouse pancreas tissue slices to study the concentration dependence of glucose-induced responses in large populations of beta cells. Beta cells respond to glucose within a narrow and physiological concentration range. At least three parameters appear to code the glucose concentration in beta cells: (i) recruitment of beta cells, (ii) advancement of their response and (iii) amplification of their activity, each with its own coding properties [1]. Moreover, applying advanced analytical tools from complex network theory, we demonstrated that communities (i.e., functional subcompartments) exist within beta cell populations. These change with the stimulus concentration from highly segregated under low stimulatory conditions to more integrated functional networks under high stimulation [2]. Moreover, we utilized these methodological approaches in a mouse model of western diet-induced obesity, characterized by signs of the adult onset type 2 diabetes, in search for potential changes in stimulus-secretion coupling [3].


Jurij Dolenšek obtained his PhD in 2007 working on fish olfaction at the Department of Biology, University of Ljubljana, Slovenia. He spends most of his research employing electrophysiological methods and calcium imaging in mouse pancreas and adrenal tissue slices. He is an assistant professor at the Faculty of Medicine, University of Maribor, Slovenia. Currently, he is a postdoctoral researcher at the Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden. In his spare time, he likes running, cycling, snowboarding, playing squash, badminton, and playing with his children.

References:

  1. Stozer, A., et al., Recruitment of beta cells during glucose stimulation in mouse pancreas tissue slices in preparation.
  2. Markovic, R., et al., Progressive glucose stimulation of islet beta cells reveals a transition from segregated to integrated modular functional connectivity patterns. Sci Rep, 2015. 5: p. 7845.
  3. Valladolid-Acebes, I., et al., An adult diet-induced obesity as a mouse model for prediabetic and diabetic states of type 2 diabetes mellitus. in preparation.

Host: Anders Tengholm (anders.tengholm@mcb.uu.se).