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Published on: September 1, 2015
Increased expression of secreted frizzled-related protein 4 in polycystic kidneys
Daniel Romaker1, Michael Puetz, Sven Teschner
1Renal Division, University Hospital Freiburg, Hugstetter Strasse 55, D-79106 Freiburg, Germany.
Abstract:
Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disease associated with progressive renal failure. Although cyst growth and compression of surrounding tissue may account for some loss of renal tissue, the other factors contributing to the progressive renal failure in patients with ADPKD are incompletely understood. Here, we report that secreted frizzled-related protein 4 (sFRP4) is upregulated in human ADPKD and in four different animal models of PKD, suggesting that sFRP4 expression is triggered by a common mechanism that underlies cyst formation. Cyst fluid from ADPKD kidneys activated the sFRP4 promoter and induced production of sFRP4 protein in renal tubular epithelial cell lines. Antagonism of the vasopressin 2 receptor blocked both promoter activity and tubular sFRP4 expression. In addition, sFRP4 selectively influenced members of the canonical Wnt signaling cascade and promoted cystogenesis of the zebrafish pronephros. sFRP4 was detected in the urine of both patients and animals with PKD, suggesting that sFRP4 may be a potential biomarker for monitoring the progression of ADPKD. Taken together, these observations suggest a potential role for SFRP4 in the pathogenesis of ADPKD.
Insights
Secreted frizzled-related protein 4 (sFRP4) is elevated in autosomal dominant polycystic kidney disease (ADPKD), driving cyst formation. Urinary sFRP4 may serve as a biomarker for monitoring ADPKD progression.
Area of Science:
- Nephrology
- Molecular Biology
- Genetics
Background:
- Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary kidney disorder leading to renal failure.
- Mechanisms beyond cyst compression contributing to renal failure in ADPKD are not fully understood.
Purpose of the Study:
- To investigate the role of secreted frizzled-related protein 4 (sFRP4) in ADPKD pathogenesis.
- To explore sFRP4 as a potential biomarker for ADPKD progression.
Main Methods:
- Analysis of sFRP4 expression in human ADPKD and animal models of polycystic kidney disease (PKD).
- Investigated sFRP4 promoter activity and protein production using renal tubular epithelial cells stimulated with ADPKD cyst fluid.
- Examined the effect of vasopressin 2 receptor antagonism on sFRP4 expression.
- Assessed sFRP4's influence on Wnt signaling and zebrafish pronephros cystogenesis.
- Detected sFRP4 in urine of patients and animals with PKD.
Main Results:
- sFRP4 is upregulated in human ADPKD and multiple PKD animal models.
- ADPKD cyst fluid activates the sFRP4 promoter and induces sFRP4 production, which is blocked by vasopressin 2 receptor antagonism.
- sFRP4 influences canonical Wnt signaling and promotes cystogenesis in zebrafish.
- Urinary sFRP4 is detected in both human and animal PKD models.
Conclusions:
- sFRP4 plays a role in ADPKD pathogenesis by promoting cystogenesis.
- sFRP4 upregulation is linked to a common mechanism underlying cyst formation in PKD.
- Urinary sFRP4 shows potential as a biomarker for monitoring ADPKD progression.
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