ifgf23  (Quidel)

Journal: Kidney International Reports

Article Title: Markers of Mineral Metabolism in Children With CKD Stages 2 to 5D

doi: 10.1016/j.ekir.2026.103800

Figure Lengend Snippet: Markers for chronic kidney disease–mineral and bone disorder in children with CKD according to CKD stages. Values for (a) phosphate, (b) iFGF23, (c) total FGF23, and (d) iPTH are given as age- and sex-related z-scores. For patients on dialysis treatment, estimated glomerular filtration rate was set to 10 ml/min per 1.73 m 2 . Gray shaded areas indicate the normal range (mean ± 2 SD), with the 0-line highlighted in white. #, ##, ### and #### indicate statistical significance from healthy controls at P < 0.05, P < 0.01, P < 0.001, and P < 0.0001, respectively (1-sample t test or Wilcoxon signed rank test according to Kolgorow-Smirnov normality test). Values not sharing superscript letters a, b, c, and d are significantly different from the values for other CKD stages (1-way analysis of variance, followed by Tukey’s multiple comparisons, or Kruskal-Wallis-test, followed by Dunn’s multiple comparisons). CKD, chronic kidney disease; FGF23, fibroblast growth factor 23; iFGF23, intact FGF23; iPTH, intact parathyroid hormone.

Article Snippet: Enzyme-linked immunosorbent assay kits were used for quantitative determination of iFGF23 (Quidel, Catalog # 60-6600, RRID: AB_2891250 ), total FGF23 using the C-term FGF23 assay kit, which measures both the full-length hormone and its posttranslationally cleaved C-terminal fragments (Quidel, Catalog # 60-6100, RRID: AB_2722648 ), sKlotho (Immuno Biological Laboratories, Catalog # 27998, RRID: AB_2750859 ) in plasma, and sclerostin (TECO Medical, Catalog # TE1023-HS, RRID: AB_2894880 ) in serum.

Techniques: Filtration

Journal: Kidney International Reports

Article Title: Markers of Mineral Metabolism in Children With CKD Stages 2 to 5D

doi: 10.1016/j.ekir.2026.103800

Figure Lengend Snippet: Markers for chronic kidney disease–mineral and bone disorder in children with chronic kidney disease as a function of eGFR. Values for (a) phosphate, (b) calcium, (c) sclerostin, (d) 25(OH)D, (e) total FGF23, (f) iFGF23, (g) sKlotho, (h) iPTH, (i) 1,25(OH) 2 D 3 , and (j) AP are given as age- and sex-related z-scores. For patients on dialysis treatment, eGFR was set to 10 ml/min per 1.73 m 2 . The respective best-fit function (sigmoidal, linear, or semilogarithmic) is presented, with the blue-shaded area indicating the 95% confidence interval. Gray shaded areas indicate the normal range (mean ± 2 SD), with the 0-line highlighted in white. 1,25(OH) 2 D 3 , 1,25-dihydroxy vitamin D 3 ; 25(OH)D, 25-hydroxyvitamin D3; AP, alkaline phosphatase; eGFR, estimated gloemrular filtration rate; FGF23, fibroblast growth factor 23; iFGF23, intact FGF23; sKlotho, soluble Klotho; iPTH, intact parathyroid hormone.

Article Snippet: Enzyme-linked immunosorbent assay kits were used for quantitative determination of iFGF23 (Quidel, Catalog # 60-6600, RRID: AB_2891250 ), total FGF23 using the C-term FGF23 assay kit, which measures both the full-length hormone and its posttranslationally cleaved C-terminal fragments (Quidel, Catalog # 60-6100, RRID: AB_2722648 ), sKlotho (Immuno Biological Laboratories, Catalog # 27998, RRID: AB_2750859 ) in plasma, and sclerostin (TECO Medical, Catalog # TE1023-HS, RRID: AB_2894880 ) in serum.

Techniques: Filtration

Journal: Kidney International Reports

Article Title: Markers of Mineral Metabolism in Children With CKD Stages 2 to 5D

doi: 10.1016/j.ekir.2026.103800

Figure Lengend Snippet: Alterations in the ratio of iFGF23 to (a) phosphate (Pi) and (b) calcium (Ca) in pediatric patients with chronic kidney disease as a function of eGFR. For patients on dialysis treatment, eGFR was set to 10 ml/min per 1.73 m 2 . Data are given as age- and sex-related z-scores. The respective best-fit function (semi-logarithmic) is presented, with the blue-shaded area indicating the 95% confidence interval. Gray shaded areas indicate the normal range (mean ± 2 SD), with the 0-line highlighted in white. eGFR, estimated gloemrular filtration rate; iFGF23, intact fibroblast growth factor 23.

Article Snippet: Enzyme-linked immunosorbent assay kits were used for quantitative determination of iFGF23 (Quidel, Catalog # 60-6600, RRID: AB_2891250 ), total FGF23 using the C-term FGF23 assay kit, which measures both the full-length hormone and its posttranslationally cleaved C-terminal fragments (Quidel, Catalog # 60-6100, RRID: AB_2722648 ), sKlotho (Immuno Biological Laboratories, Catalog # 27998, RRID: AB_2750859 ) in plasma, and sclerostin (TECO Medical, Catalog # TE1023-HS, RRID: AB_2894880 ) in serum.

Techniques: Filtration

Journal: Kidney International Reports

Article Title: Markers of Mineral Metabolism in Children With CKD Stages 2 to 5D

doi: 10.1016/j.ekir.2026.103800

Figure Lengend Snippet: Overview of the dynamic changes of 8 key markers for chronic kidney disease– mineral and bone disorder in pediatric patients with chronic kidney disease as determined in the present study, as a function of eGFR. Values for iFGF23, iPTH, phosphate, 25(OH)D, sKlotho, calcium, 1,25(OH) 2 D 3 , and sclerostin are given as age- and sex-related z-scores. For patients undergoing dialysis, eGFR was set to 10 ml/min per 1.73 m 2 . The respective best-fit function (sigmoidal, linear, or semilogarithmic) is presented, with the blue shaded area indicating the 95% confidence interval. Gray shaded areas indicate the normal range (mean ± 2 SD), with the 0-line highlighted in white. 1,25(OH) 2 D 3 , 1,25-dihydroxy vitamin D 3 ; 25(OH)D, 25-hydroxyvitamin D3; eGFR, estimated gloemrular filtration rate; iFGF23, intact fibroblast growth factor 23; iPTH, intact parathyroid hormone; sKlotho, soluble Klotho.

Article Snippet: Enzyme-linked immunosorbent assay kits were used for quantitative determination of iFGF23 (Quidel, Catalog # 60-6600, RRID: AB_2891250 ), total FGF23 using the C-term FGF23 assay kit, which measures both the full-length hormone and its posttranslationally cleaved C-terminal fragments (Quidel, Catalog # 60-6100, RRID: AB_2722648 ), sKlotho (Immuno Biological Laboratories, Catalog # 27998, RRID: AB_2750859 ) in plasma, and sclerostin (TECO Medical, Catalog # TE1023-HS, RRID: AB_2894880 ) in serum.

Techniques: Filtration

Journal: The FASEB Journal

Article Title: High Phosphate Load Induces De Novo Formation of Tertiary Lymphoid Structures in the Kidney

doi: 10.1096/fj.202500968R

Figure Lengend Snippet: High phosphate, not the increase of fibroblast growth factor 23 (FGF23), drives tubular injury and perivascular tertiary lymphoid structure (TLS) formation. (a) Schematic representation of the study design including specific time points for adeno‐associated virus (AAV) treatment inducing the overexpression of fibroblast growth factor 23 (FGF23), dietary intervention, as well as biosampling and tissue collection. (b) Quantification of plasma intact FGF23 (iFGF23) concentrations, serum phosphate (Pi), serum creatinine (Crea), and urinary albumin to creatinine ratio (ACR) in all three groups. (c) Representative images of the cortex of hematoxylin and eosin (HE), periodic acid‐Schiff (PAS), and picrosirius red stained kidney cross‐sections, as well as immunofluorescence (IF) staining of kidney injury molecule 1 (Kim‐1; orange) positive tubules. (d) Quantification of the scoring of tubular injury, of real‐time PCR analysis of Havcr1 , and of kidney fibrosis in the cortex. (e) Representative HE, PAS and picrosirius red staining focusing on the perivascular region of TLS development. (f) Representative IF costaining of CD45R + (green) and CD3 + (orange) lymphocytes, of CD45R (green) and Ki67 (orange), and of IgD (red) synthesis. (g) Quantification of lymphocytes using flow cytometry analysis of whole kidney tissue from mice of all three groups. (c, f) Counterstaining of cell nuclei using DAPI (blue). (c, e and f) Scale bars: 100 μm. (b, d, g) Data are presented as mean ± SD. One‐way analysis of variance (ANOVA) with Tukey's multiple comparisons test, * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001. A, artery.

Article Snippet: To specifically enhance circulating iFgf23 levels, 8‐week‐old male C57BL/6NCtrl mice (Charles River) received an adeno‐associated virus serotype 9 in which the full‐length cDNA of murine Fgf23 (AAV‐Fgf23) was subcloned as described previously [ ].

Techniques: Virus, Over Expression, Clinical Proteomics, Staining, Immunofluorescence, Real-time Polymerase Chain Reaction, Flow Cytometry

Journal: The FASEB Journal

Article Title: High Phosphate Load Induces De Novo Formation of Tertiary Lymphoid Structures in the Kidney

doi: 10.1096/fj.202500968R

Figure Lengend Snippet: Elevated fibroblast growth factor 23 (FGF23) levels in hypophosphatemic mice do not cause kidney damage or promote the formation of tertiary lymphoid structures (TLS). (a) Schematic representation of the study design including time point for biosampling and tissue collection. (b) Quantification of plasma intact FGF23 (iFGF23) concentrations, serum phosphate (Pi), serum creatinine (Crea), and urinary albumin to creatinine ratio (ACR) in all three groups. (c) Representative images of the cortex of hematoxylin and eosin (HE), periodic acid‐Schiff (PAS), and picrosirius red stained kidney cross‐sections, as well as immunofluorescence (IF) staining of kidney injury molecule 1 (Kim‐1; orange) with DAPI (blue) counterstaining. Scale bars: 100 μm. (d) Quantification of the scoring of tubular injury, of real‐time PCR analysis of Havcr1 transcription, and of kidney fibrosis in the cortex. (b, d) Data are presented as mean ± SD. Unpaired t ‐tests with **** p < 0.0001.

Article Snippet: To specifically enhance circulating iFgf23 levels, 8‐week‐old male C57BL/6NCtrl mice (Charles River) received an adeno‐associated virus serotype 9 in which the full‐length cDNA of murine Fgf23 (AAV‐Fgf23) was subcloned as described previously [ ].

Techniques: Clinical Proteomics, Staining, Immunofluorescence, Real-time Polymerase Chain Reaction

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 lowers iFGF23 level in CKD rats and CKD patients. Parameters measured include ( A ) Serum intact fibroblast growth factor 23 (iFGF23) levels in CKD rats. B Serum total FGF23 levels in CKD rats. C Serum iFGF23 levels in CKD patients. D Serum total FGF23 levels in CKD patients. E Scatter plots with linear regression analysis demonstrating a significant correlation between blood urea nitrogen (BUN) and iFGF23 levels in CKD rats. F Scatter plots with linear regression analysis showing a significant correlation between Scr and iFGF23 levels in CKD rats. G Scatter plots with linear regression analysis revealing a significant correlation between iFGF23 levels and the percentage of fibrotic area in the kidney of CKD rats. H Scatter plots with linear regression analysis indicating a significant correlation between iFGF23 levels and Collagen 1 staining intensity in the kidney of CKD rats. I Scatter plots with linear regression analysis illustrating a significant correlation between iFGF23 levels and Fibronectin staining intensity in the kidney of CKD rats. J Scatter plots with linear regression analysis demonstrating a significant correlation between iFGF23 levels and α-SMA staining intensity in the kidney of CKD rats. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Staining

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: iFGF23 mediates FG-4592-induced inhibition of tubular cell fibrogenesis. HK-2 cells were pre-treated with TGF-β1 (10 ng/mL) for 24 h, followed by treatment with recombinant FGF23 (rFGF23, 50 ng/mL) or vehicle for an additional 24 h. Parameters measured include: A COL1A1 mRNA expression levels in HK-2 cells, as determined by quantitative PCR (qPCR). B TGFB1 mRNA expression levels in HK-2 cells, as determined by qPCR. C Collagen 1 protein expression levels in HK-2 cells, as assessed by Western blot analysis. D Schematic illustration of the co-culture system using UMR-106 cells and HK-2 cells in a Transwell setup. E mRNA expression levels of Fn1 , Acta2 , and Col1a1 in HK-2 cells, as quantified by qPCR. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Inhibition, Recombinant, Expressing, Real-time Polymerase Chain Reaction, Western Blot, Co-Culture Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 ameliorates TIF by inhibiting iFGF23-WNT5A pathway. Parameters measured include ( A ) Hierarchical clustering analysis revealing distinct mRNA expression profiles among the experimental groups. Yellow and blue shades indicate expression levels above and below the relative mean, respectively, across all samples. B Gene Ontology (GO) enrichment analysis. C Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. D and F mRNA and protein expression levels of Wnt5a and β-catenin in the following groups: sham, CKD + vehicle, and CKD + FG-4592. E and G mRNA and protein expression levels of Wnt5a and β-catenin in the following groups: CKD + FG-4592 + vehicle and CKD + FG-4592 + rFGF23. H and I Representative immunohistochemical images showing Wnt5a and β-catenin expression in kidney tissues across different experimental groups. J mRNA expression levels of COL1A1 , ACTA1 , WNT5A , and CTNNB1 in HK-2 cells following WNT5A siRNA interference, as determined by quantitative PCR (qPCR). K Protein expression levels of Collagen 1, Wnt5a, and β-catenin in HK-2 cells after WNT5A siRNA interference, as assessed by Western blot analysis. Scale bars: 50 μm. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing, Immunohistochemical staining, Real-time Polymerase Chain Reaction, Western Blot

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 lowers iFGF23 levels through Furin-mediated cleavage. Parameters measured include ( A ) mRNA expression levels of Furin , Galnt3 , and Fam20c in bone tissues from the following groups: sham, CKD + vehicle, and CKD + FG-4592, as determined by quantitative PCR (qPCR). B Protein levels of HIF-1α, Furin, and intact fibroblast growth factor 23 (iFGF23) in bone tissues treated with FG-4592 or vehicle, as assessed by Western blot analysis. C Representative images of hematoxylin and eosin (HE) staining of bone tissues (scale bars: 20 μm), along with IHC staining for HIF-1α and iFGF23 (scale bars: 50 μm) and Furin (scale bars: 100 μm). D UMR-106 cells were pretreated with 10 nM 1,25(OH) 2 D 3 , and the expression of FGF23 mRNA was analyzed using real-time PCR. E Western blot analysis was performed to measure iFGF23 protein expression in UMR-106 cells. Cells were pretreated with indoxyl sulfate (IS, 0.5 mM) or vehicle, followed by treatment with FG-4592 (50 μM) or vehicle for 24 h. F Levels of iFGF23 and total FGF23 in the cell supernatant were quantified using an ELISA assay kit. G Western blot analysis was used to evaluate the protein expression of iFGF23 and Furin in UMR-106 cells. H Motif map of the Furin promoter region, highlighting the HIF-1 binding site. I ChIP assays demonstrated HIF-1 binding to the Furin promoter, which was enhanced by FG-4592 stimulation (50 μM for 24 h). J Protein expression levels of Furin and iFGF23 in UMR-106 cells following Furin siRNA interference, as determined by Western blot analysis. K Levels of iFGF23 and total FGF23 in the cell supernatant were measured using an ELISA assay kit after Furin siRNA interference. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing, Real-time Polymerase Chain Reaction, Western Blot, Staining, Immunohistochemistry, Enzyme-linked Immunosorbent Assay, Binding Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: Schematic illustration of FG-4592 ameliorating TIF. During CKD, FG-4592 transcriptionally upregulates Furin expression, which subsequently cleaves iFGF23, leading to a reduction in iFGF23 levels and amelioration of TIF

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 lowers iFGF23 level in CKD rats and CKD patients. Parameters measured include ( A ) Serum intact fibroblast growth factor 23 (iFGF23) levels in CKD rats. B Serum total FGF23 levels in CKD rats. C Serum iFGF23 levels in CKD patients. D Serum total FGF23 levels in CKD patients. E Scatter plots with linear regression analysis demonstrating a significant correlation between blood urea nitrogen (BUN) and iFGF23 levels in CKD rats. F Scatter plots with linear regression analysis showing a significant correlation between Scr and iFGF23 levels in CKD rats. G Scatter plots with linear regression analysis revealing a significant correlation between iFGF23 levels and the percentage of fibrotic area in the kidney of CKD rats. H Scatter plots with linear regression analysis indicating a significant correlation between iFGF23 levels and Collagen 1 staining intensity in the kidney of CKD rats. I Scatter plots with linear regression analysis illustrating a significant correlation between iFGF23 levels and Fibronectin staining intensity in the kidney of CKD rats. J Scatter plots with linear regression analysis demonstrating a significant correlation between iFGF23 levels and α-SMA staining intensity in the kidney of CKD rats. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Staining

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: iFGF23 mediates FG-4592-induced inhibition of tubular cell fibrogenesis. HK-2 cells were pre-treated with TGF-β1 (10 ng/mL) for 24 h, followed by treatment with recombinant FGF23 (rFGF23, 50 ng/mL) or vehicle for an additional 24 h. Parameters measured include: A COL1A1 mRNA expression levels in HK-2 cells, as determined by quantitative PCR (qPCR). B TGFB1 mRNA expression levels in HK-2 cells, as determined by qPCR. C Collagen 1 protein expression levels in HK-2 cells, as assessed by Western blot analysis. D Schematic illustration of the co-culture system using UMR-106 cells and HK-2 cells in a Transwell setup. E mRNA expression levels of Fn1 , Acta2 , and Col1a1 in HK-2 cells, as quantified by qPCR. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Inhibition, Recombinant, Expressing, Real-time Polymerase Chain Reaction, Western Blot, Co-Culture Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 ameliorates TIF by inhibiting iFGF23-WNT5A pathway. Parameters measured include ( A ) Hierarchical clustering analysis revealing distinct mRNA expression profiles among the experimental groups. Yellow and blue shades indicate expression levels above and below the relative mean, respectively, across all samples. B Gene Ontology (GO) enrichment analysis. C Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. D and F mRNA and protein expression levels of Wnt5a and β-catenin in the following groups: sham, CKD + vehicle, and CKD + FG-4592. E and G mRNA and protein expression levels of Wnt5a and β-catenin in the following groups: CKD + FG-4592 + vehicle and CKD + FG-4592 + rFGF23. H and I Representative immunohistochemical images showing Wnt5a and β-catenin expression in kidney tissues across different experimental groups. J mRNA expression levels of COL1A1 , ACTA1 , WNT5A , and CTNNB1 in HK-2 cells following WNT5A siRNA interference, as determined by quantitative PCR (qPCR). K Protein expression levels of Collagen 1, Wnt5a, and β-catenin in HK-2 cells after WNT5A siRNA interference, as assessed by Western blot analysis. Scale bars: 50 μm. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing, Immunohistochemical staining, Real-time Polymerase Chain Reaction, Western Blot

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: FG-4592 lowers iFGF23 levels through Furin-mediated cleavage. Parameters measured include ( A ) mRNA expression levels of Furin , Galnt3 , and Fam20c in bone tissues from the following groups: sham, CKD + vehicle, and CKD + FG-4592, as determined by quantitative PCR (qPCR). B Protein levels of HIF-1α, Furin, and intact fibroblast growth factor 23 (iFGF23) in bone tissues treated with FG-4592 or vehicle, as assessed by Western blot analysis. C Representative images of hematoxylin and eosin (HE) staining of bone tissues (scale bars: 20 μm), along with IHC staining for HIF-1α and iFGF23 (scale bars: 50 μm) and Furin (scale bars: 100 μm). D UMR-106 cells were pretreated with 10 nM 1,25(OH) 2 D 3 , and the expression of FGF23 mRNA was analyzed using real-time PCR. E Western blot analysis was performed to measure iFGF23 protein expression in UMR-106 cells. Cells were pretreated with indoxyl sulfate (IS, 0.5 mM) or vehicle, followed by treatment with FG-4592 (50 μM) or vehicle for 24 h. F Levels of iFGF23 and total FGF23 in the cell supernatant were quantified using an ELISA assay kit. G Western blot analysis was used to evaluate the protein expression of iFGF23 and Furin in UMR-106 cells. H Motif map of the Furin promoter region, highlighting the HIF-1 binding site. I ChIP assays demonstrated HIF-1 binding to the Furin promoter, which was enhanced by FG-4592 stimulation (50 μM for 24 h). J Protein expression levels of Furin and iFGF23 in UMR-106 cells following Furin siRNA interference, as determined by Western blot analysis. K Levels of iFGF23 and total FGF23 in the cell supernatant were measured using an ELISA assay kit after Furin siRNA interference. Data are presented as means ± SD ( n = 5). Statistical significance is denoted as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing, Real-time Polymerase Chain Reaction, Western Blot, Staining, Immunohistochemistry, Enzyme-linked Immunosorbent Assay, Binding Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The Roxadustat (FG-4592) ameliorates tubulointerstitial fibrosis by promoting intact FGF23 cleavage

doi: 10.1186/s12964-025-02175-2

Figure Lengend Snippet: Schematic illustration of FG-4592 ameliorating TIF. During CKD, FG-4592 transcriptionally upregulates Furin expression, which subsequently cleaves iFGF23, leading to a reduction in iFGF23 levels and amelioration of TIF

Article Snippet: The iFGF23 concentration was examined on plasma collected from rats under fed conditions using ELISA assays specific for rat iFGF23 (Quidel, cat#: 60–6800). iFGF23 and cFGF23 concentration were examined on plasma collected from rats under fed conditions using ELISA assays specific for rat total FGF23 (Quidel, cat#: 60–6300). iFGF23 and cFGF23 concentration were examined on plasma collected from CKD patients under fed conditions using ELISA assays specific for human iFGF23 or total FGF23 (Quidel, cat#: 60–6600 and cat#: 60–6100). iFGF23 ELISAs detect full-length, biologically active FGF23 that can exert phosphaturia, whereas total FGF23 ELISAs detect both iFGF23 and its C-terminal fragments and therefore provide a measure of the total amount of circulating plasma FGF23.

Techniques: Expressing