Hyperphosphatemia increases inflammation to exacerbate anemia and skeletal muscle wasting independently of FGF23-FGFR4 signaling

  1. Brian Czaya
  2. Kylie Heitman
  3. Isaac Campos
  4. Christopher Yanucil
  5. Dominik Kentrup
  6. David Westbrook
  7. Orlando Gutierrez
  8. Jodie L Babitt
  9. Grace Jung
  10. Isidro B Salusky
  11. Mark Hanudel
  12. Christian Faul  Is a corresponding author
  1. Division of Nephrology and Hypertension, Department of Medicine, The University of Alabama at Birmingham, United States
  2. Department of Medicine, David Geffen School of Medicine at UCLA, United States
  3. Division of Nephrology, Program in Membrane Biology, Massachusetts General Hospital, Harvard Medical School, United States
  4. Department of Pediatrics, David Geffen School of Medicine at UCLA, United States
8 figures, 8 tables and 1 additional file

Figures

Figure 1 with 1 supplement
FGF23-FGFR4 signaling does not contribute to functional iron deficiency in adenine-induced CKD.

Blood urea nitrogen (BUN), serum creatinine (A), serum FGF23 and serum phosphate (Pi) levels (B). Quantitative polymerase chain reaction (qPCR) analysis of Il1b, Il6, Saa1 (C, D) and Hamp (E) expression levels in liver tissue. (F) Complete blood count (CBC) analysis. (G) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (scale bar, 50 μm). Larger magnification is shown in supplementary figure and legends. (H) Liver Pi levels. All values are mean ± standard error of the mean (SEM; n = 8–9 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + control diet, #p ≤ 0.05 vs. Fgfr4−/− + control diet, $p ≤ 0.05 vs. Fgfr4+/+ + adenine diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median Fgfr4+/+ + control diet measurements.

Figure 1—figure supplement 1
FGF23-FGFR4 signaling does not contribute to functional iron deficiency in adenine-induced CKD.

(A) Serum calcium analysis from Fgfr4+/+ and Fgfr4−/− mice, fed either control or adenine diet. (B) Hematocrit percentage (HCT%), mean corpuscular hematocrit (MCH), and serum transferrin saturation percentage (TSAT%) analysis in Fgfr4+/+ and Fgfr4−/− mice, fed either control or adenine diet. (C) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (original magnification, ×40; scale bar, 20 μm). All values are mean ± standard error of the mean (SEM; n = 8–9 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + control diet, #p ≤ 0.05 vs. Fgfr4−/− + control diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate corresponding median measurements from Fgfr4+/+ mice on control diet.

Figure 2 with 2 supplements
FGF23-FGFR4 signaling does not contribute to hypoferremia following dietary Pi overload.

(A) Serum FGF23 and serum Pi levels. (B, C) Quantitative polymerase chain reaction (qPCR) analysis of Il1b, Il6, and Saa1 expression levels in liver tissue. (D) Scatter plots showing correlations between liver Pi and serum Pi levels. (E) Scatter plots showing correlations between liver Hamp expression and liver Pi levels (a = slopes are significantly different from each other). (F) CBC analysis. (G) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (scale bar, 50 μm). Larger magnification is shown in supplementary figure and legends. All values are mean ± standard error of the mean (SEM; n = 8 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + 0.7% Pi diet, #p ≤ 0.05 vs. Fgfr4−/− + 0.7% Pi diet, $p ≤ 0.05 vs. Fgfr4+/+ + 2% Pi diet, @p ≤ 0.05 vs. Fgfr4−/− + 2% Pi diet, &p ≤ 0.05 vs. Fgfr4+/+ + 3% Pi diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median Fgfr4+/+ + 0.7% Pi diet measurements. Scatter plot shadows indicate 95% confidence interval.

Figure 2—figure supplement 1
FGF23-FGFR4 signaling does not contribute to hypoferremia following dietary Pi overload.

(A) Serum calcium analysis from Fgfr4+/+ and Fgfr4−/− mice, fed either a 0.7% Pi diet or an escalating Pi diet (2% Pi diet or 3% Pi diet). (B, C) BUN and serum creatinine analysis from Fgfr4+/+ and Fgfr4−/− mice, fed either a 0.7% Pi diet or an escalating Pi diet (2% Pi diet or 3% Pi diet). (D) Representative gross pathology of H&E-stained kidney sections (original magnification, ×20; scale bar, 50 μm) from Fgfr4+/+ and Fgfr4−/− mice, fed either a 0.7% Pi diet or an escalating Pi diet (2% Pi diet or 3% Pi diet). No pathologic changes were detected in sections stained with H&E, as Fgfr4+/+ and Fgfr4−/− mice on a 2% Pi or 3% Pi diet display similar results to Fgfr4+/+ mice fed a 0.7% Pi diet. (E) Representative gross pathology of Masson’s trichrome-stained kidney sections (original magnification, ×20; scale bar, 50 μm) from Fgfr4+/+ and Fgfr4−/− mice, fed either a 0.7% Pi diet or an escalating Pi diet (2% Pi diet or 3% Pi diet). No interstitial fibrosis was detected in sections stained with Masson’s trichrome, as Fgfr4+/+ and Fgfr4−/− mice on a 2% Pi or 3% Pi diet display similar results to Fgfr4+/+ mice fed a 0.7% Pi diet. (F) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (original magnification, ×40; scale bar, 20 μm). All values are mean ± standard error of the mean (SEM; n = 8 mice/group). Dotted lines indicate corresponding median measurements from Fgfr4+/+ mice on 0.7% Pi diet.

Figure 2—figure supplement 2
Liver injury marker and hematological analyses in Fgfr4+/+ and Fgfr4−/− mice fed a graded Pi diet.

(A, B) Quantitative polymerase chain reaction (qPCR) analysis of liver tissue shows expression levels of alanine aminotransferase (Alt1) and aspartate aminotransferase (Ast1) are not significantly elevated in Fgfr4+/+ and Fgfr4−/− mice, fed either a 2% Pi diet or 3% Pi diet, when compared to Fgfr4+/+ mice on a 0.7% Pi diet. (C) Hematocrit percentage (HCT%) and mean corpuscular hematocrit (MCH) analysis in Fgfr4+/+ and Fgfr4−/− mice, fed either a 0.7% Pi diet or an escalating Pi diet (2% Pi diet or 3% Pi diet). All values are mean ± standard error of the mean (SEM; n = 8 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + 0.7% Pi diet, #p ≤ 0.05 vs. Fgfr4−/− + 0.7% Pi diet, #p ≤ 0.05 vs. Fgfr4+/+ + 2% Pi diet, @p ≤ 0.05 vs. Fgfr4−/− + 2% Pi diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate corresponding median measurements from Fgfr4+/+ mice on 0.7% Pi diet.

Figure 3 with 1 supplement
Mouse models of hyperphosphatemia exhibit signs of skeletal muscle wasting which are independent of FGF23-FGFR4 signaling.

(A) Grip strength. (B) Gastrocnemius weight. Quantitative polymerase chain reaction (qPCR) analysis of Mstn (C), Murf1 and Atrogin1 (D) expression levels in gastrocnemius tissue. (E) Representative gross pathology of H&E-stained gastrocnemius sections (scale bar, 20 μm). All values are mean ± standard error of the mean (SEM) ((n = 8–9 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + control diet, #p ≤ 0.05 vs. Fgfr4−/− + control diet); (n = 8 mice/group; αp ≤ 0.05 vs. Fgfr4+/+ + 0.7% Pi diet, βp ≤ 0.05 vs. Fgfr4−/− + 0.7% Pi diet, γp ≤ 0.05 vs. Fgfr4+/+ + 2% Pi diet, δp ≤ 0.05 vs. Fgfr4−/− + 2% Pi diet)) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median Fgfr4+/+ + control diet or Fgfr4+/+ + 0.7% Pi diet measurements.

Figure 3—figure supplement 1
Models of hyperphosphatemia exhibit signs of skeletal muscle wasting and low Pi feeding in Col4a3−/− (Alport syndrome) mice counteracts muscle dysfunction.

(A–C) Quantitative (qPCR) analysis of gastrocnemius tissue shows expression levels of metallothionein-1 (Mt1) are significantly elevated in Fgfr4+/+ and Fgfr4−/− mice fed either adenine (A) or a 3% Pi diet (B). Alport (Col4a3−/−) mice on control diet (0.6% Pi diet) display elevated expression levels of Mt1 in gastrocnemius tissue, when compared to wild-type (Col4a3+/+) on a 0.6% Pi diet (C). A low Pi diet (0.2% Pi) in Alport mice reduces Mt1 expression levels (C). All values are mean ± standard error of the mean (SEM) ((n = 8–9 mice/group; *p ≤ 0.05 vs. Fgfr4+/+ + control diet, #p ≤ 0.05 vs. Fgfr4−/− + control diet); (n = 8 mice/group; αp ≤ 0.05 vs. Fgfr4+/+ + 0.7% Pi diet, βp ≤ 0.05 vs. Fgfr4−/− + 0.7% Pi diet, γp ≤ 0.05 vs. Fgfr4+/+ + 2% Pi diet, δp ≤ 0.05 vs. Fgfr4−/− + 2% Pi diet); (n = 7–9 mice/group; εp ≤ 0.05 vs. Col4a3+/+ + 0.6% Pi diet, ςp ≤ 0.05 vs. Col4a3−/− + 0.6% Pi diet)) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate corresponding median measurements from Fgfr4+/+ mice on control diet (A), Fgfr4+/+ mice on 0.7% Pi diet (B), or Col4a3+/+ mice on 0.6% Pi diet (C).

Figure 4 with 1 supplement
Low Pi feeding limits functional iron deficiency in Col4a3−/− (Alport ) mice.

BUN, serum creatinine (A), serum FGF23 and serum Pi levels (B). Quantitative polymerase chain reaction (qPCR) analysis of Il1b, Il6, and Saa1 (C, D) and Hamp (E) expression levels in liver tissue. (F) CBC analysis. (G) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (scale bar, 50 μm). Larger magnification is shown in supplementary figure and legends. (H) Liver Pi levels. All values are mean ± standard error of the mean (SEM; n = 7–9 mice/group; *p ≤ 0.05 vs. Col4a3+/+ + 0.6% Pi diet, #p ≤ 0.05 vs. Col4a3−/− + 0.6% Pi diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median Col4a3+/+ + 0.6% Pi diet measurements.

Figure 4—figure supplement 1
Low Pi feeding limits functional iron deficiency in Col4a3−/− (Alport ) mice.

(A) Representative gross pathology of H&E-stained kidney sections (original magnification, ×20; scale bar, 50 μm) from wild-type (Col4a3+/+) and Alport (Col4a3−/−) mice, fed either control diet (0.6% Pi) or a low Pi diet (0.2% Pi). Pathologic changes were detected in sections stained with H&E from Alport mice fed a 0.6% Pi diet. A 0.2% Pi diet moderately improves this feature in Alport mice. (B) Hematocrit percentage (HCT%), mean corpuscular hematocrit (MCH), and serum transferrin saturation percentage (TSAT%) analysis in wild-type (Col4a3+/+) and Alport (Col4a3−/−) mice, fed either control diet (0.6% Pi) or a low Pi diet (0.2% Pi). (C) Spleen nonheme iron concentrations in wild-type (Col4a3+/+) and Alport (Col4a3−/−) mice, fed either control diet (0.6% Pi) or a low Pi diet (0.2% Pi). (D) Liver nonheme iron concentrations in wild-type (Col4a3+/+) and Alport (Col4a3−/−) mice, fed either control diet (0.6% Pi) or a low Pi diet (0.2% Pi). (E) Representative gross pathology of Perls’ Prussian blue-stained spleen sections (original magnification, ×40; scale bar, 20 μm). All values are mean ± standard error of the mean (SEM; n = 7–9 mice/group; *p ≤ 0.05 vs. Col4a3+/+ + 0.6% Pi diet, #p ≤ 0.05 vs. Col4a3−/− + 0.6% Pi diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate corresponding median measurements from Col4a3+/+ mice on 0.6% Pi diet.

Low Pi feeding counteracts signs of skeletal muscle wasting in Col4a3−/− (Alport ) mice.

(A) Grip strength. (B) Gastrocnemius weight. Quantitative polymerase chain reaction (qPCR) analysis of Mstn (C), Murf1 and Atrogin1 (D) expression levels in gastrocnemius tissue. (E) Representative gross pathology of H&E-stained gastrocnemius sections (scale bar, 20 μm). All values are mean ± standard error of the mean (SEM; n = 7–9 mice/group; *p ≤ 0.05 vs. Col4a3+/+ + 0.6% Pi diet, #p ≤ 0.05 vs. Col4a3−/− + 0.6% Pi diet) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median Col4a3+/+ + 0.6% Pi diet measurements.

Figure 6 with 1 supplement
Pi targets hepatocytes and increases expression of inflammatory cytokines and hepcidin.

(A) Immunoblot analysis of total protein extracts from primary hepatocytes (n = 5 independent isolations). β-Actin serves as loading control. Quantitative polymerase chain reaction (qPCR) analysis of Il1b, Il6, Saa1 (B, C), Hamp (D), and Slc20a1 (E) expression levels in primary hepatocytes; values are mean ± standard error of the mean (SEM; n = 4 independent isolations; *p ≤ 0.05 vs. control [Ctrl]). Dotted lines indicate median Ctrl measurements. (F) qPCR analysis of Slc20a1 expression levels in primary hepatocytes following stimuli, with or without phosphonoformic acid (PFA); values are mean ± standard error of the mean (SEM; n = 6 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs. 1 mM PFA Ctrl). Dotted lines indicate median vehicle Ctrl measurements. (G) Immunoblot analysis of total and phosphorylated p65 (NFκB) protein levels from primary hepatocytes following stimuli, with or without PFA (n = 5 independent isolations). β-Actin serves as loading control. (H–J) qPCR analysis of Il1b, Il6, Saa1 (H–I) and Hamp (J) expression levels in primary hepatocytes following stimuli, with or without PFA; values are mean ± standard error of the mean (SEM; n = 6 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs. 1 mM PFA Ctrl) where statistical analyses were calculated by one-way analysis of variance (ANOVA; B–E) or by two-way ANOVA (F, H–J) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median vehicle Ctrl measurements.

Figure 6—source data 1

Original western blots.

Original uncropped western blots of the cropped western blots shown in Figure 6A, G. The molecular weight is indicated on the right in kDa.

https://cdn.elifesciences.org/articles/74782/elife-74782-fig6-data1-v2.zip
Figure 6—figure supplement 1
Pi targets hepatocytes and increases expression of inflammatory cytokines and hepcidin.

(A) Quantitative polymerase chain reaction (qPCR) analysis of isolated primary hepatocytes shows absolute transcript expression of all three families of sodium phosphate cotransporters (types I, II, and III). This analysis indicates type III sodium phosphate cotransporters (Slc20a1 and Slc20a2) have the highest expression levels in mouse primary hepatocyte cultures (n = 3 independent isolations). (B) qPCR analysis of primary hepatocytes shows Slc20a2 expression levels following inflammatory, dose-dependent Pi or dose-dependent Na2SO4 treatment. No significant elevations were detected following treatments, when compared to control (Ctrl); values are mean ± standard error of the mean (SEM; n = 4 independent isolations). Dotted lines indicate corresponding median measurements from Ctrl.

Figure 7 with 1 supplement
Pi induces hepcidin expression via paracrine IL1β and IL6 signaling.

Quantitative polymerase chain reaction (qPCR) analysis of Il1b, Il6 (A) and Hamp (B) expression levels in primary hepatocytes following stimuli, with or without BAY 11-7082; values are mean ± standard error of the mean (SEM; n = 4 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs. 20 μM BAY 11-7082 Ctrl). Dotted lines indicate median vehicle Ctrl measurements. (C) qPCR analysis of Hamp expression levels in primary hepatocytes following stimuli with or without anti-IL1β, anti-IL6, or both antibodies in combination; values are mean ± standard error of the mean (SEM; n = 4 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs. anti-IL1β Ctrl, $p ≤ 0.05 vs. anti-IL6 Ctrl, @p ≤ 0.05 vs. anti-IL1β + anti-IL6 Ctrl) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate median vehicle Ctrl measurements.

Figure 7—figure supplement 1
Pi induces hepcidin expression via paracrine IL1β and IL6 signaling.

Quantitative polymerase chain reaction (qPCR) analysis of primary hepatocytes shows expression levels of Saa1 (A), Hp (B), and Slc20a1 (C) following lipopolysaccharide (LPS) or Pi stimulation, with or without BAY 11-7082; values are mean ± standard error of the mean (SEM; n = 4 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs 20 μM BAY 11-7082 Ctrl). Dotted lines indicate corresponding median measurements from vehicle Ctrl. (D, E) qPCR analysis of primary hepatocytes shows Saa1 and Hp expression levels following LPS or Pi stimulation, with or without anti-IL1β, anti-IL6, or both antibodies in combination; values are mean ± standard error of the mean (SEM; n = 4 independent isolations; *p ≤ 0.05 vs. vehicle control [Ctrl], #p ≤ 0.05 vs. anti-IL1β Ctrl, $p ≤ 0.05 vs. anti-IL6 Ctrl, @p ≤ 0.05 vs. anti-IL1β + anti-IL6 Ctrl) where statistical analyses were calculated by two-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison post hoc test. Dotted lines indicate corresponding median measurements from vehicle Ctrl.

Schematic of the effects of hyperphosphatemia on systemic inflammation, hypoferremia, and skeletal muscle wasting.

Tables

Table 1
Macroscopic parameters of Fgfr4+/+ and Fgfr4−/− mice receiving control and adenine diet.
Fgfr4+/+ + control dietFgfr4−/− + control dietFgfr4+/+ + adenine dietFgfr4−/− + adenine diet
Body weight (g)30.1 ± 0.930.2 ± 0.316.8*# ± 0.517.5*# ± 0.4
Liver weight (g)1.14 ± 0.051.22 ± 0.080.74*# ± 0.030.78*# ± 0.05
Spleen weight (mg)75.0 ± 2.276.0 ± 1.753.3*# ± 3.356.0*# ± 3.2
Left kidney weight (mg)181.8 ± 8.5173.2 ± 8.3122.2*# ± 4.9101.8*# ± 7.2
Right kidney weight (mg)184.7 ± 10.7175.2 ± 8.2124.2*# ± 4.1102.8*# ± 7.7
  1. Values are expressed as mean ± standard error of the mean (SEM). Comparison between groups was performed in form of a two-way analysis of variance (ANOVA) followed by a post hoc Tukey test. A level of p < 0.05 was accepted as statistically significant; N = 9/group; *p ≤ 0.05 vs. Fgfr4+/+ + control diet, #p ≤ 0.05 vs. Fgfr4−/− + control diet.

Table 2
Macroscopic parameters of Fgfr4+/+ and Fgfr4−/− mice receiving a graded dietary Pi load.
Fgfr4+/+ + 0.7% Pi dietFgfr4−/− + 0.7% Pi dietFgfr4+/+ + 2% Pi dietFgfr4−/− + 2% Pi dietFgfr4+/+ + 3% Pi dietFgfr4−/− + 3% Pi diet
Body weight (g)32.0 ± 1.031.9 ± 1.030.3 ± 0.931.6 ± 0.929.5 ± 0.329.5 ± 0.4
Liver weight (g)1.17 ± 0.041.15 ± 0.051.24 ± 0.031.20 ± 0.051.23 ± 0.51.19 ± 0.4
Spleen weight (mg)76.3 ± 2.468.3 ± 1.777.0 ± 2.876.6 ± 2.876.6 ± 2.174.0 ± 1.7
Left kidney weight (mg)146.5 ± 4.7143.6 ± 4.5156.0 ± 2.9152.6 ± 3.4153.4 ± 4.1152.9 ± 3.7
Right kidney weight (mg)149.0 ± 3.8151.5 ± 3.7152.9 ± 3.2145.6 ± 3.5152.5 ± 2.5149.6 ± 3.9
  1. Values are expressed as mean ± standard error of the mean (SEM). Comparison between groups was performed in form of a two-way analysis of variance (ANOVA) followed by a post hoc Tukey test. No level of statistical significance was accepted between groups; N = 8/group.

Table 3
Macroscopic parameters of Alport mice receiving either a 0.6% Pi diet or 0.2% Pi diet.
Col4a3+/+ + 0.6% Pi dietCol4a3−/− + 0.6% Pi dietCol4a3−/− + 0.2% Pi diet
Body weight (g)26.3 ± 0.616.3* ± 0.622.2*# ± 0.6
Liver weight (g)1.03 ± 0.040.68* ± 0.030.90# ± 0.03
Spleen weight (mg)72.2 ± 2.356.6* ± 2.465.9 ± 2.1
Left kidney weight (mg)145.3 ± 1.6124.1* ± 2.6130.1* ± 2.1
Right kidney weight (mg)147.4 ± 1.6123.0* ± 3.4133.6* ± 3.1
  1. Values are expressed as mean ± standard error of the mean (SEM). Comparison between groups was performed in form of a two-way analysis of variance (ANOVA) followed by a post hoc Tukey test. A level of p < 0.05 was accepted as statistically significant; N = 7–9/group; *p ≤ 0.05 vs. Col4a3+/+ + 0.6% Pi diet, #p ≤ 0.05 vs. Col4a3−/− + 0.6% Pi diet.

Key resources table
Reagent type (species) or resourceDesignationSource or referenceIdentifiersAdditional information
Strain, strain background (Mus musculus; 129/SvJ)Col4a3tm1DecJackson LaboratoryStock No. 000691Referred to as Col4a3−/−
Strain, strain background (Mus musculus; C57Bl/6)Global FGFR4 knockoutGift from Dr. Chu-Xia Deng, NIDDK, Bethesda, USAWeinstein et al., 1998, 125, 3615-23Referred to as Fgfr4−/−
AntibodyIL6 (rat monoclonal)R&D SystemsMP5-20F3For cell culture treatment (6 μg/ml)
AntibodyIL1β (goat polyclonal)R&D SystemsAF-401-NAFor cell culture treatment (6 μg/ml)
AntibodyERK1/2 (rabbit monoclonal)Cell Signaling4695For WB (1:1000)
AntibodySTAT3 (rabbit monoclonal)Cell Signaling4904For WB (1:1000)
AntibodyNFkB (rabbit monoclonal)Cell Signaling8242For WB (1:1000)
Antibodyβ-Actin (rabbit monoclonal)Cell Signaling4970For WB (1:1000)
AntibodyPhosphorylated ERK1/2 (rabbit polyclonal)Cell Signaling9101For WB (1:1000)
AntibodyPhosphorylated STAT3 (rabbit monoclonal)Cell Signaling9145For WB (1:1000)
AntibodyPhosphorylated NFκB (rabbit monoclonal)Cell Signaling3033For WB (1:1000)
AntibodyMouse IgG, HRP conjugate (goat monoclonal)PromegaW4021For WB (1:2500)
AntibodyRabbit IgG, HRP conjugate (goat monoclonal)PromegaW4011For WB (1:2500)
Peptide, recombinant proteinFGF23; mouseR&D Systems2629-FGFor cell culture treatment (25 ng/ml)
Peptide, recombinant proteinTNFα; mouseR&D Systems410-MTFor cell culture treatment (100 ng/ml)
Peptide, recombinant proteinIL6; mouseR&D Systems406 MLFor cell culture treatment (50 ng/ml)
Commercial assay or kitColorimetric Pi assayAbcamAb65622
Commercial assay or kitColorimetric iron assaySekisui157-30
Commercial assay or kitIntact FGF23 ELISA (mouse)Quidel60-6800
Commercial assay or kitPercoll gradient solutionSigma-AldrichP1644
Commercial assay or kitRNeasy Plus Mini kitQiagen74,136
Commercial assay or kitRNeasy Plus Universal Mini kitQiagen73,404
Commercial assay or kitiScript Reverse Transcriptase SupermixBioRad1708840
Commercial assay or kitSSoAdvanced Universal SYBR Green SupermixBioRad172-5272
Commercial assay or kitPierce BCA Protein AssayThermo Fisher23,225
Chemical compound, drugLipopolysaccharide (LPS) from E. coli serotype 0111:B4; endotoxin agentInvivogenTlrl-3pelpsFor cell culture treatment (100 ng/ml)
Chemical compound, drugSodium phosphate dibasic anhydrousFisherBP332-500
Chemical compound, drugSodium phosphate monobasic anhydrousFisherBP329-1
Chemical compound, drugSodium SulfateSigma-Aldrich239,313
Chemical compound, drugPhosphonoformic acid (PFA)Sigma-AldrichP6801
Chemical compound, drugBAY 11-7082SelleckhemS2913For cell culture treatment (20 μM)
Software, algorithmGraphPad PrismGraphPad
Other0.2% adenine dietEnvigoTD.140290Diet for mice
Other0.15% adenine dietEnvigoTD.170304Diet for mice
OtherAdenine control dietEnvigoTD.170303Diet for mice
Other0.7% Pi dietEnvigoTD.180287Diet for mice
Other2% Pi dietEnvigoTD.08020Diet for mice
Other3% Pi dietEnvigoTD.180286Diet for mice
Other0.6% Pi dietEnvigoTD.200407Diet for mice
Other0.2% Pi dietEnvigoTD.200406Diet for mice
Table 4
Composition of control and adenine diets.
DietAdenine(g/kg)Available Pi (%)Total Ca (%)Protein sourceEnergy sourcePi source
TD.170303(control diet)00.90.6Casein20% protein66.9% carbs13.2% fatCaseinCa Pi, dibasicNa Pi, dibasic
TD.170304(0.15% adenine)1.50.90.6Casein20% protein66.8% carbs13.2% fatCaseinCa Pi, dibasicNa Pi, dibasic
TD.140290(0.2% adenine)20.90.6Casein20% protein66.8% carbs13.2% fatCaseinCa Pi, dibasicNa Pi, dibasic
  1. Pi, phosphate; Ca, calcium; Na, sodium. These diets were manufactured by Envigo.

Table 5
Composition of 0.7%, 2%, and 3% phosphate (Pi) diets.
DietAvailable Pi (%)Total Ca (%)Total iron (ppm)Total K (%)Total Na (%)Protein sourceEnergy sourcePi source
TD.180287(0.7% Pi diet)0.71.92802.41.2Crude33.3% protein53.9% carbs12.8% fatCrude protein
TD.08020(2% Pi diet)2.01.92801.80.9Crude33.3% protein53.9% carbs12.8% fatCrude proteinK Pi, monobasicNa Pi, monobasic
TD.180286(3% Pi diet)3.01.92802.41.2Crude33.3% protein53.9% carbs12.8% fatCrude proteinK Pi, monobasicNa Pi, monobasic
  1. Pi, phosphate; Ca, calcium; K, potassium; Na, sodium. These diets were manufactured by Envigo.

Table 6
Composition of 0.6% and 0.2% phosphate (Pi) diets.
DietAvailable Pi (%)Total Ca (%)Total iron (ppm)Total K (%)Total na (%)Protein sourceEnergy sourcePi source
TD.200407(0.6% Pi diet, normal)0.60.6400.60.38Egg white solids17.7% protein65% carbs17.3% fatEgg white solidsCa Pi, monobasic
TD.200406(0.2% Pi diet)0.20.6400.60.38Egg white solids17.5% protein65.4% carbs17.1% fatEgg white solidsCa Pi, monobasic
  1. Pi, phosphate; Ca, calcium; K, potassium; Na, sodium. These diets were manufactured by Envigo.

Table 7
Oligonucleotides used as sequence specific primers in quantitative polymerase chain reaction (qPCR) analyses.
GeneSpeciesOrientationPrimer sequence (5′–3′)
Npt-1/Slc17a1Mus musculusForwardReverseGGC ACC TCC CTT AGA ACG AGCAG AAC ACA CCC AAC AAT ACC AAA
Npt-4/Slc17a3Mus musculusForwardReverseTGG TAC CCA TTG TTG CTG GCGGG ACA GCT TCA CAA ACG AGT
NaPi-2a/Slc34a1Mus musculusForwardReverseTCA TTG TCA GCA TGG TCT CCT CCCT GCA AAA GCC CGC CTG
NaPi-2b/Slc34a2Mus musculusForwardReverseCTC CTG CTG TCC CTT ACC TGTGT CAT TTG TTT TGC TGG CCT C
NaPi-2c/Slc34a3Mus musculusForwardReverseGAT GCC TTT GAC CTG GTG GAGCC ATG CCA ACC TCT TTC AG
PiT-1/Slc20a1Mus musculusForwardReverseTTC CTT GTT CGT GCG TTC ATCAAT TGG TAA AGC TCG TAA GCC ATT
PiT-2/Slc20a2Mus musculusForwardReverseGAC CGT GGA AAC GCT AAT GGCTC AGG AAG GAC GCG ATC AA
Fgfr1Mus musculusForwardReverseGCT TGA CGT CGT GGA ACG ATAGC CAC TGA ATG TGA GGC TG
Fgfr2Mus musculusForwardReverseATC CCC CTG CGG AGA CAGAG GAC AGA CGC GTT GTT ATC C
Fgfr3Mus musculusForwardReverseGTG TGC GTG TAA CAG ATG CTCCGG GCG AGT CCA ATA AGG AG
Fgfr4Mus musculusForwardReverseTGA AGA GTA CCT TGA CCT CCGTCA TGT CGT CTG CGA GTC AG
Alt1/Gpt1Mus musculusForwardReverseGCC CTC GAG TAC TAT GCG TCTGT CTT GGT ATA CCT CAT CAG CC
Ast1/Got1Mus musculusForwardReverseCTG AAT GAT CTG GAG AAT GCC CTGC AAA GCC CTG ATA GGC TG
Il6Mus musculusForwardReverseCTC TGG GAA ATC GTG GAA ATCCA GTT TGG TAG CAT CCA TC
Il1bMus musculusForwardReverseTGC CAC CTT TTG ACA GTG ATGTGA TGT GCT GCT GCG AGA TT
Saa1Mus musculusForwardReverseACA CCA GCA GGA TGA AGC TAC TGAG CAT GGA AGT ATT TGT CTG AGT
HampMus musculusForwardReverseGAG CAG CAC CAC CTA TCT CCTTG GTA TCG CAA TGT CTG CC
Haptoglobin/HpMus musculusForwardReverseAGA GAG GCA AGA GAG GTC CAGGC AGC TGT CAT CTT CAA AGT
Atrogin1/Fbxo32Mus musculusForwardReverseTGA GCG ACC TCA GCA GTT ACGCG CTC CTT CGT ACT TCC TT
Murf1/Trim63Mus musculusForwardReverseGAG GGC CAT TGA CTT TGG GATGG TGT TCT TCT TTA CCC TCT GT
MstnMus musculusForwardReverseCTC CAG AAT AGA AGC CAT AGCA GAA GTT GTC TTA TAG C
Mt1Mus musculusForwardReverseCGA CTT CAA CGT CCT GAG TACAGG AGC TGG TGC AAG TG
18S rRNA/Rn18sMus musculusForwardReverseTTG ACG GAA GGG CAC CAC CAGGCA CCA CCA CCC ACG GAA TCG
GapdhMus musculusForwardReverseCCA ATG TGT CCG TCG TGG ATC TGTT GAA GTC GCA GGA GAC AAC C

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  1. Brian Czaya
  2. Kylie Heitman
  3. Isaac Campos
  4. Christopher Yanucil
  5. Dominik Kentrup
  6. David Westbrook
  7. Orlando Gutierrez
  8. Jodie L Babitt
  9. Grace Jung
  10. Isidro B Salusky
  11. Mark Hanudel
  12. Christian Faul
(2022)
Hyperphosphatemia increases inflammation to exacerbate anemia and skeletal muscle wasting independently of FGF23-FGFR4 signaling
eLife 11:e74782.
https://doi.org/10.7554/eLife.74782