Nordicautophagy.org

Report from Lab Exchange Grantee Florentina Negoita

The role of SIK2 in autophagy and its link to human adipose tissue dysfunction in the development of type 2 diabetes

Host: Pr. Eeva-Liisa Eskelinen (University of Turku, Finland)

Duration of visit: 2 weeks (September 30 – October 11, 2019)

The aim of this project is to characterize the molecular mechanisms underlying the regulation of autophagy by SIK2 in adipocytes. Transmission electron microscopy (TEM) is currently considered to be the gold standard test for the evaluation of autophagy, but identification of autophagic structures is challenging, without proper expertise, and might lead to false conclusions. Thus, in order to learn how to correctly identify and differentiate autophagic structures from other cellular structures and how to quantify the TEM images, a research visit was organized in the lab of Pr Eeva-Liisa Eskelinen, a leading scientist on TEM imaging of autophagic structures. Adipocytes treated with a SIK inhibitor were imaged and images were then analyzed. We found a marked change in the number and volume of autolysosomes, in line with our previous data. With the protocol for TEM sample processing obtained through this collaboration, we are now planning to further explore our findings by establishing the TEM method in our own laboratory, and applying it to 3T3-L1 adipocytes treated with SIK2 siRNA. We will maintain an active collaboration with Pr Eeva-Liisa Eskelinen. In conclusion, the research visit was very successful. I received excellent training in TEM analysis of autophagic structures, and we also generated novel, interesting data, which has opened up a new direction of study in the project.