Fig. 2: Carbohydrate loading-induced protein dilution is required for protection against IRI.

a Food (left) and water (right) intake (normalized by body weight) of 10-weeks-old male mice given ad libitum access to water (Ctrl) or 50% sucrose-water (HC). b Total calorie intake normalized to body weight by day. c Body weight at the indicated time in mice given ad libitum access to Ctrl or HC. d Total calorie intake by macronutrient normalized to body weight by day. The % of protein intake is indicated on top of each bar. e Relationship between sucrose intake and protein intake, and (f) fiber intake and protein intake in humans from the US National Health and Nutrition Examination Survey (NHANES). Box plots represent median with 25th and 75th percentile. Whiskers plots represent hinge ± 1.5 IQR. g Representative cross sections of PAS-stained kidneys with necrotic area digitally highlighted in red (left; x10 magnification; scale bar 100 µm) and quantification of necrotic tissue area (right) at day 2 post-renal IRI after one week of preconditioning with low protein diet (LP) combined with Ctrl or HC. The red line indicates the level of the control group (Ctrl). h Serum urea levels (AUC) post-renal IRI after one week of preconditioning with the indicated diet. The red line indicates the level of the control group (Ctrl). i Serum creatinine levels at day 3 post-renal IRI. The red line indicates the level of the control group (Ctrl). j Relative Krt20 mRNA levels in kidneys at day 2 post-renal IRI after one week of preconditioning with the indicated diet. The red line indicates the level of the control group (Ctrl). k Serum creatinine levels at day 1 post-renal IRI after one week of preconditioning with Ctrl, HC or HC with cysteine oral gavage (HC + cysteine). l. Serum urea levels (AUC) post-renal IRI after one week of preconditioning with the indicated diet. m. Representative cross sections of PAS-stained kidneys with necrotic area digitally highlighted in red (left; x10 magnification; scale bar 100 µm) and quantification of necrotic tissue area (right) at day 2 postrenal IRI after one week of preconditioning with the indicated diet. n Relative Krt20 mRNA levels in kidney at day 2 post-renal IRI after one week of preconditioning with the indicated diet. o Relationship between serum urea at day 2 post-renal IRI and dietary protein intake or carbohydrate or fat intake. In all surfaces, red indicates the highest value while blue indicates the lowest value, with the colors standardized across each slice. *p values for a–c were calculated with two-way repeated measures (RM) ANOVA with Geisser-Greenhouse correction, k–n with unpaired two-tailed T-test and o. with a generalized additive model (GAM; k = 6), *p < 0.05 **p < 0.01 ****p < 0.0001. p values for a are respectively <0.0001 and <0.0001, for b < 0.0001, for k = 0.0411, for l = 0.0283 and 0.0171, for m = 0.0474 and 0.0019, for n = 0.0174. In a–d and g–o, experiments were carried out in 10-weeks old male mice. Sample sizes: (a–d), n = 8; (e-f), n = 11064 men, 12181 women (g-j), n = 8-9, n = 8 for low protein Ctrl, and n = 9 for HC; (k–n), n = 5 for all conditions; (o), n = 16 for all conditions. Data in all panels are shown as mean ± SD. See also Supplementary Data Figs. 2 and 3.