Volume 85, Issue 6, Pages 1340-1350 (June 2014) Renal expression of FGF23 and peripheral resistance to elevated FGF23 in rodent models of polycystic kidney disease  Daniela Spichtig, Hongbo Zhang, Nilufar Mohebbi, Ivana Pavik, Katja Petzold, Gerti Stange, Lanja Saleh, Ilka Edenhofer, Stephan Segerer, Jürg Biber, Philippe Jaeger, Andreas L. Serra, Carsten A. Wagner  Kidney International  Volume 85, Issue 6, Pages 1340-1350 (June 2014) DOI: 10.1038/ki.2013.526 Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 1 Fibroblast growth factor 23 (FGF23), parathyroid hormone (PTH), and renal function. Plasma concentrations of (a) FGF23, (b) PTH, (c) creatinine, and (d) urea after 2, 4, 6, and 8 weeks in cy/+ (black squares) and +/+ (wild type; white squares) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=11.5 and +/+=11. *P<0.05 and **P<0.001. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 2 Fibroblast growth factor 23 (FGF23) expression in kidney. (a) Relative mRNA expression of FGF23 to 18S rRNA in bone and kidney after 2, 4, and 8 weeks in cy/+ (black bars) and +/+ (wild type; white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=6 and +/+=5.5. **P<0.001. Immunohistochemistry for FGF23 (green), calbindin D28k (red), a marker for distal convoluted tubules and connecting tubules, and 4',6-diamidino-2-phenylindole (DAPI; blue, cell nuclei). (b, c) Kidneys from 8-week-old cy/+ rats, (d, e) kidneys from 8-week-old control rats, and (f) kidney from 8-week-old cy/+ rat incubated with secondary antibodies alone. Original magnification × 400. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 3 Vitamin D3 metabolism. (a) Plasma concentration of 1,25-dihydroxyvitamin (1,25(OH)2) vitamin D3, and relative mRNA expression of the (b) vitamin D receptor (VDR) as well as (c) Cyp27b1 and (d) Cyp24a1 enzymes in the kidney to 18S rRNA after 2, 4, and 8 weeks in cy/+ (black bars) and +/+ (wild type; white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=6 and +/+=5. *P<0.05 and **P<0.001. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 4 Renal phosphate and calcium handling. Plasma concentrations of (a) phosphate and (b) calcium as well as (c) ratio of the maximum rate of tubular phosphate reabsorption to the glomerular filtration rate (TmP/GFR) and (d) fractional excretion of calcium (FECa) ratio after 2, 4, 6, and 8 weeks in cy/+ (black squares) and +/+ (wild type; white squares) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=11.5 and +/+ =11. *P<0.05. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 5 Phosphate transporter mRNA expression. Relative mRNA expression of (a) NaPi-IIa and (b) NaPi-IIc to 18S rRNA after 2, 4, and 8 weeks in cy/+ (black bars) and +/+ (wild type; white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=6 and +/+=6. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 6 Phosphate transporter protein expression. Relative protein expression of NaPi-IIa and NaPi-IIc to β-actin after (a) 2, (b) 4, and (c) 8 weeks in cy/+ (black bars) and +/+ (wild type; white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=6 and +/+=6. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 7 Phosphate and glucose uptake into renal brush border membrane vesicles. Phosphate uptake (a) without and (b) with phosphonoformic acid (PFA) and (c) glucose uptake after 2, 4, and 8 weeks in cy/+ (black bars) and +/+ (wild type; white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=11 and +/+=7. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 8 Klotho expression and phosphorylation state of fibroblast growth factor (FGF) receptor substrate 2α (FRS2a). (a) Relative mRNA expression of Klotho in kidney to 18S rRNA after 2, 4, and 8 weeks; (b) relative protein expression of Klotho and (c) phosphorylation state of FRS2a (pFRS2a) to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) after 8 weeks in cy/+ (black bars) and +/+ (white bars) Han:SPRD rats (mean ±s.d.); number of animals (median): cy/+=4 and +/+=4. *P<0.05. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 9 Fibroblast growth factor 23 (FGF23), parathyroid hormone (PTH), ratio of the maximum rate of tubular phosphate reabsorption to the glomerular filtration rate (TmP/GFR), and renal function in Pkd1fl/fl mice. (a) Plasma intact FGF23 and (b) PTH as well as (c) TmP/GFR and (d) creatinine clearance after 10 weeks in Pkd1fl/fl, cre+ (black bars) and Pkd1fl/fl, cre- (white bars) mice (mean ±s.d.); number of animals (median): Pkd1fl/fl, cre+=7 and Pkd1fl/fl, cre-=16. *P<0.05. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 10 Fibroblast growth factor 23 (FGF23) and Klotho expression in bone and kidneys of Pkd1fl/fl mice. Relative mRNA expression of FGF23 in (a) kidney and (b) bone as well as (c) Klotho in kidney to 18S rRNA after 10 weeks in Pkd1fl/fl, cre+ (black bars) and Pkd1fl/fl, cre- (white bars) mice (mean ±s.d.); number of animals (median): Pkd1fl/fl, cre+=8 and Pkd1fl/fl, cre-=15. **P<0.001. Kidney International 2014 85, 1340-1350DOI: (10.1038/ki.2013.526) Copyright © 2014 International Society of Nephrology Terms and Conditions