AMPK activity and ATP levels were analyzed from retinas expressing FRET biosensors.
Two photon microscopy, live ex vivo culture
Jiazhou He, Masamichi Yamamoto, Kenta Sumiyama, Yumi Konagaya, Kenta Terai, Michiyuki Matsuda, Shinya Sato (2021) Two-photon AMPK and ATP imaging reveals the bias between rods and cones in glycolysis utility., FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Volume 35, Number 9, pp. e21880
Published in 2021 Sep
(Abstract) In vertebrates, retinal rod and cone photoreceptor cells rely significantly on glycolysis. Lactate released from photoreceptor cells fuels neighboring retinal pigment epithelium cells and Muller glial cells through oxidative phosphorylation. To understand this highly heterogeneous metabolic environment around photoreceptor cells, single-cell analysis is needed. Here, we visualized cellular AMP-activated protein kinase (AMPK) activity and ATP levels in the retina by two-photon microscopy. Transgenic mice expressing a hyBRET-AMPK biosensor were used for measuring the AMPK activity. GO-ATeam2 transgenic mice were used for measuring the ATP level. Temporal metabolic responses were successfully detected in the live retinal explants upon drug perfusion. A glycolysis inhibitor, 2-deoxy-d-glucose (2-DG), activated AMPK and reduced ATP. These effects were clearly stronger in rods than in cones. Notably, rod AMPK and ATP started to recover at 30 min from the onset of 2-DG perfusion. Consistent with these findings, ex vivo electroretinogram recordings showed a transient slowdown in rod dim flash responses during a 60-min 2-DG perfusion, whereas cone responses were not affected. Based on these results, we propose that cones surrounded by highly glycolytic rods become less dependent on glycolysis, and rods also become less dependent on glycolysis within 60 min upon the glycolysis inhibition.(MeSH Terms)