Fig. 8: Genetic and pharmacological inhibition of EPRS1 improves mitochondrial dysfunction in FA mice and HK-2 cells.

a Representative images of aquaporin-1 (AQP-1) from IHC-stained kidneys. Scale bar = 100 μm. b The AQP-1-positive area was quantified by ImageJ analysis (n = 4–6). c Representative electron microscopy (EM) micrographs showing the effects of genetic Eprs1 inhibition on FA mice. The asterisk indicates tubular basement membrane thickening. The arrows indicate swollen mitochondria in each group (n = 4–6). Scale bar = 5 μm. d, e Quantitative data on the mitochondrial length and aspect ratio (ratio of large to small axes) were analyzed by ImageJ (n = 4–6). f Adenosine triphosphate (ATP) contents in whole kidney tissues from the three groups (n = 4–6). g, h Relative mRNA levels of ATP synthase and NADH dehydrogenase 1 (ND1) were analyzed via qPCR and normalized to those of 18S rRNA (n = 4–6). i Representative images of AQP-1 from IHC-stained kidneys used to assess the effect of the EPRS1 inhibitor. Scale bar = 100 μm. j The AQP-1-positive area was quantified by ImageJ analysis (n = 7–9). k Representative EM micrographs of kidney fibrosis in FA mice with or without EPRS1i treatment. The asterisk indicates tubular basement membrane thickening. The arrow indicates swollen mitochondria in FA mice. Scale bar = 5 μm. l, m Quantitative data on the mitochondrial length and aspect ratio were analyzed using ImageJ (n = 7–9). n ATP contents in whole kidney tissues from the five groups (n = 7–9). o, p Representative confocal images and quantitative data showing tetramethylrhodamine methyl ester (TMRM) activity in siEPRS1 (20 nM)-treated HK-2 cells under TGF-β (10 ng/ml) treatment conditions for 24 h (n = 4). Scale bar = 50 μm. q ATP contents in siEPRS1 (20 nM)-treated cells under TGF-β (10 ng/ml) treatment conditions were determined according to the manufacturer’s protocol (n = 4). Scale bar = 50 μm. r, s Representative confocal images and quantitative data showing TMRM in EPRS1i (1 μM)-treated cells under TGF-β (10 ng/ml) treatment conditions for 24 h (n = 8). Scale bar = 50 μm. t ATP contents in EPRS1i (1 μM)-treated cells under TGF-β (10 ng/ml) treatment conditions (n = 6). The data are presented as mean ± standard deviation. Statistical data were analyzed by ANOVA with Tukey’s post hoc test. *P < 0.05, **P < 0.01, and ***P < 0.001. siEPRS1: siRNA-mediated EPRS1.