Background: In contrast to many other cells, healthy endothelial cells obtain most of their energy from glycolysis rather than oxidative phosphorylation even when adequately oxygenated1,2. Although a less efficient energy source (2 ATP in net gain per glucose molecule) compared to oxidative phosporylation (Up to 38 ATP in net gain under optimal conditions), glycolysis confers several benefits, including relative resistance to oxidative stress and increased oxygen transfer to underlying tissues. Correspondingly, endothelial mitochondria appear to be more important for integration of cellular functions and defense against oxidative stress than for energy production. Recent studies have demonstrated that altered cellular metabolism contributes to the regulation of endothelial cell behavior during formation of new blood vessels1,3 and that inhibition of glycolytic enzymes reduces disease severity in animal models of chronic inflammation3,4. Even so, little is known about how inflammation affects metabolic pathways in endothelial cells and how this again may regulate endothelial activation.
Current data: We have observed that inflammatory activation strongly increases endothelial cell glucose uptake and glycolysis; and conversely, that inhibition of glycolysis reduces endothelial activation in response to proinflammatory stimuli.
Project plan: Culture of primary human endothelial cells; Inhibition of glycolysis by small molecule inhibitors and knockdown of glycolytic enzymes; Assessment of endothelial activation by assessing cytoskeletal remodeling and expression of inflammatory mediators; Pinpointing mechanisms involved in inhibiting endothelial activation by assessing activation of signaling molecules and luciferase reporter assays.
Relevant techniques: Cell culture, transfection, lentiviral transduction, RT-PCR, Western blot, ELISA, immunofluorescent staining, confocal microscopy.
The research environment: The student will be based in Guttorm Haraldsens group at Department of Pathology, Oslo University Hospital. The group has extensive experience in endothelial activation, inflammation and immunopathology, and in addition to the senior scientist that will be the main supervisor for the project (JH), 2 PhD students and 2 Postdocs are currently working on related projects, providing a positive and enthusiastic environment to learn techniques, working with more experienced coworkers and discussing results as we go along. Our group is also part of the K.G.Jebsen Inflammation Research Centre, providing additional expertise on metabolism and inflammation. The project also benefits from collaborating with Peter Carmeliet?s group at the Vesalius Research Centre at KU Leuven, Belgium, the first to describe the effect of glycolysis on endothelial cell behaviour during new vessel formation1,3.
8. References
1. De Bock K, Georgiadou M, Schoors S, et al. Role of PFKFB3-Driven Glycolysis in Vessel Sprouting. Cell. 2013;154(3):651–663. doi:10.1016/j.cell.2013.06.037.
2. Peters K, Kamp G, Berz A, et al. Changes in human endothelial cell energy metabolic capacities during in vitro cultivation. The role of “aerobic glycolysis” and proliferation. Cell Physiol Biochem. 2009;24(5-6):483–492. doi:10.1159/000257490.
3. Schoors S, De Bock K, Cantelmo AR, et al. Partial and Transient Reduction of Glycolysis by PFKFB3 Blockade Reduces Pathological Angiogenesis. Cell Metabolism. 2014;19(1):37–48. doi:10.1016/j.cmet.2013.11.008.
4. Telang S, Clem BF, Klarer AC, et al. Small molecule inhibition of 6-phosphofructo-2-kinase suppresses t cell activation. J Transl Med. 2012;10:95. doi:10.1186/1479-5876-10-95.