Figure 2

FGFR5 overexpression in primary mouse beta-cells induces a more robust glucose stimulated NADPH response​. To confirm the FGFR5-induced metabolic effects in primary tissue, R5 was overexpressed in murine beta-cells and the metabolic response observed by live cell imaging. Mouse islets were dispersed to single cells onto glass bottom dishes and co-transduced with the Apollo-NADP⁺ sensor using a CMV promoter and one of the mCherry constructs (R5, R5ΔC, or mChe; as indicated) using a rat insulin promoter. (a) Widefield fluorescence (WD Fluor) and anisotropy images from the same representative beta-cell exposed to multiple glucose concentrations, as indicated. (Scale bar = 5 μm; anisotropy lookup table for widefield anisotropy =  × 10^–2). (b) Apollo-NADP⁺ response (ΔAnisotropy) of mCherry positive beta-cell cells overexpressing R5, mChe, and R5ΔC in response to sequential glucose concentrations, as indicated. (c) Traces of individual Apollo-NADP⁺ responses collected across three separate days are represented for mChe-expressing beta-cells. The lines are color-coded based on being above (orange-brown) or below (light blue-dark blue) the average 15 mM glucose response (ΔAnisotropy represented by the hatched black line = 19 × 10^–3). Different shades were used to indicate when the magnitude of response was above (orange) and below (dark blue) the mean response. (d) The Apollo-NADP⁺ responses of R5 and R5ΔC expressing beta-cells (traces shown in Fig. S3) were classified as either strong (orange) or weak (dark blue) glucose responders based on the mean value defined by the mChe cells. Bars indicate % cell distribution for each construct. Bars graph shows the average ± SEM of n = 3 independent experiments. *, p < 0.05 using ANOVA followed by one-tailed t-test.