Extended Data Fig. 8: Examination of relative single cell cytosolic and mitochondrial Ca2+ concentrations as well as mitochondrial membrane potential following β-cell LONP1 deficiency.
(a) [Ca2+]cyt (left) and [Ca2+]mito (right) changes were simultaneously assessed in individual cells from the same control islet following cytosolic Cal520 uptake and mito-R-Geco transduction in response to 3, 11, and 17 mM glucose (3 G, 11 G and 17 G) and 20 mM KCl. (n = 5 cells, each color represents one cell). (b) [Ca2+]cyt (left) and [Ca2+]mito (right) changes were simultaneously assessed in individual cells from the same β-LonP1KO islet following cytosolic Cal520 uptake and mito-R-Geco transduction in response to 3, 11, and 17 mM glucose (3 G, 11 G and 17 G) and 20 mM KCl (n = 4 cells, each color represents one cell). (c) Δψm measured in dissociated β-cells loaded with 10 nM TMRM following exposure to 3- and 17-mM glucose (3 G and 17 G), or 1 µM FCCP. Traces represent normalized fluorescence intensity over time (F/Fmin) n = 120 islets/group (3 mice/group). Pink dashed box highlights changes in Δψm before and after FCCP exposure. (d) Change in Δψm post FCCP, measured as the difference between Δψm from time 13–13.5 min (after 1 µM FCCP exposure) and time 12.5–13 min (prior to FCCP) corresponding to pink dashed box in Extended Data Fig. 8c. Each dot represents an individual cell. n = 103 cells/Ctrl group, n = 104 cells/ β-LonP1KO group (3 mice/group). All data in figure are presented as mean ± SEM. Statistical analysis: 10D, **P < 0.01 by unpaired two-tailed Student’s t-test.
