9 research outputs found
Four-jointed knock-out delays renal failure in an ADPKD model with kidney injury
Autosomal Dominant Polycystic Kidney Disease is characterised by the development of fluid-filled cysts in the kidneys which lead to end-stage renal disease (ESRD). In the majority of cases, the disease is caused by a mutation in the Pkd1 gene. In a previous study, we demonstrated that renal injury can accelerate cyst formation in Pkd1 knock-out (KO) mice. In that study, we found that after injury four-jointed (Fjx1), an upstream regulator of planar cell polarity and the Hippo pathway, was aberrantly expressed in Pkd1 KO mice compared to WT. Therefore, we hypothesised a role for Fjx1 in injury/repair and cyst formation. We generated single and double deletion mice for Pkd1 and Fjx1, and we induced toxic renal injury using the nephrotoxic compound 1,2-dichlorovinyl-cysteine. We confirmed that nephrotoxic injury can accelerate cyst formation in Pkd1 mutant mice. This caused Pkd1 KO mice to reach ESRD significantly faster; unexpectedly, double KO mice survived significantly longer. Cyst formation was comparable in both models, but we found significantly less fibrosis and macrophage infiltration in double KO mice. Taken together, these data suggest that Fjx1 disruption protects the cystic kidneys against kidney failure by reducing inflammation and fibrosis. Moreover, we describe, for the first time, an interesting (yet unidentified) mechanism that partially discriminates cyst growth from fibrogenesis. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland
Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease
Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the V2RA can be improved by dose titration of the V2RA aiming to maintain aquaresis at a high level. Methods: The V2RA OPC-31260 was administered to Pkd1-deletion mice in an FD (0.1%) or in a titrated dose (TD, up to 0.8% when drinking volume dropped). Total kidney weight (TKW) and cyst ratio were investigated and compared to non-treated Pkd1-deletion mice. Treatment was started early or late (21 or 42 days postnatal). Results: Water intake was significantly higher throughout the experiment in the TD compared to the FD group. FD treatment that was initiated early reduced TKW and cyst ratio but lost its renoprotective effect later during the experiment. In contrast, TD treatment was able to maintain the renoprotective effect. TD treatment, however, was also associated with a higher early termination rate in comparison with FD treatment. Late start of treatment (FD or TD) did not show a renoprotective effect. Conclusions: Titration of a V2RA aimed to maintain aquaresis at a high level showed a better renoprotective effect compared to FD administration. However, this treatment regimen was poorly tolerated and did not overcome treatment unresponsiveness when started later in the disease. (C) 2016 S. Karger AG, Base
Scattered Deletion of PKD1 in Kidneys Causes a Cystic Snowball Effect and Recapitulates Polycystic Kidney Disease
In vitro 3D phenotypic drug screen identifies celastrol as an effective in vivo inhibitor of polycystic kidney disease
Polycystic kidney disease (PKD) is a prevalent genetic disorder, characterized by the formation of kidney cysts that progressively lead to kidney failure. The currently available drug tolvaptan is not well tolerated by all patients and there remains a strong need for alternative treatments. The signaling rewiring in PKD that drives cyst formation is highly complex and not fully understood. As a consequence, the effects of drugs are sometimes difficult to predict. We previously established a high throughput microscopy phenotypic screening method for quantitative assessment of renal cyst growth. Here, we applied this 3D cyst growth phenotypic assay and screened 2320 small drug-like molecules, including approved drugs. We identified 81 active molecules that inhibit cyst growth. Multi-parametric phenotypic profiling of the effects on 3D cultured cysts discriminated molecules that showed preferred pharmacological effects above genuine toxicological properties. Celastrol, a triterpenoid from Tripterygium Wilfordii, was identified as a potent inhibitor of cyst growth in vitro. In an in vivo iKspCre-Pkd1lox,lox mouse model for PKD, celastrol inhibited the growth of renal cysts and maintained kidney function
PowerPoint Slides for: Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease
Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the V2RA can be improved by dose titration of the V2RA aiming to maintain aquaresis at a high level. Methods: The V2RA OPC-31260 was administered to Pkd1-deletion mice in an FD (0.1%) or in a titrated dose (TD, up to 0.8% when drinking volume dropped). Total kidney weight (TKW) and cyst ratio were investigated and compared to non-treated Pkd1-deletion mice. Treatment was started early or late (21 or 42 days postnatal). Results: Water intake was significantly higher throughout the experiment in the TD compared to the FD group. FD treatment that was initiated early reduced TKW and cyst ratio but lost its renoprotective effect later during the experiment. In contrast, TD treatment was able to maintain the renoprotective effect. TD treatment, however, was also associated with a higher early termination rate in comparison with FD treatment. Late start of treatment (FD or TD) did not show a renoprotective effect. Conclusions: Titration of a V2RA aimed to maintain aquaresis at a high level showed a better renoprotective effect compared to FD administration. However, this treatment regimen was poorly tolerated and did not overcome treatment unresponsiveness when started later in the disease
PowerPoint Slides for: Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease
Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the V2RA can be improved by dose titration of the V2RA aiming to maintain aquaresis at a high level. Methods: The V2RA OPC-31260 was administered to Pkd1-deletion mice in an FD (0.1%) or in a titrated dose (TD, up to 0.8% when drinking volume dropped). Total kidney weight (TKW) and cyst ratio were investigated and compared to non-treated Pkd1-deletion mice. Treatment was started early or late (21 or 42 days postnatal). Results: Water intake was significantly higher throughout the experiment in the TD compared to the FD group. FD treatment that was initiated early reduced TKW and cyst ratio but lost its renoprotective effect later during the experiment. In contrast, TD treatment was able to maintain the renoprotective effect. TD treatment, however, was also associated with a higher early termination rate in comparison with FD treatment. Late start of treatment (FD or TD) did not show a renoprotective effect. Conclusions: Titration of a V2RA aimed to maintain aquaresis at a high level showed a better renoprotective effect compared to FD administration. However, this treatment regimen was poorly tolerated and did not overcome treatment unresponsiveness when started later in the disease
Supplementary Material for: Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease
Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the V2RA can be improved by dose titration of the V2RA aiming to maintain aquaresis at a high level. Methods: The V2RA OPC-31260 was administered to Pkd1-deletion mice in an FD (0.1%) or in a titrated dose (TD, up to 0.8% when drinking volume dropped). Total kidney weight (TKW) and cyst ratio were investigated and compared to non-treated Pkd1-deletion mice. Treatment was started early or late (21 or 42 days postnatal). Results: Water intake was significantly higher throughout the experiment in the TD compared to the FD group. FD treatment that was initiated early reduced TKW and cyst ratio but lost its renoprotective effect later during the experiment. In contrast, TD treatment was able to maintain the renoprotective effect. TD treatment, however, was also associated with a higher early termination rate in comparison with FD treatment. Late start of treatment (FD or TD) did not show a renoprotective effect. Conclusions: Titration of a V2RA aimed to maintain aquaresis at a high level showed a better renoprotective effect compared to FD administration. However, this treatment regimen was poorly tolerated and did not overcome treatment unresponsiveness when started later in the disease
Supplementary Material for: Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease
Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the V2RA can be improved by dose titration of the V2RA aiming to maintain aquaresis at a high level. Methods: The V2RA OPC-31260 was administered to Pkd1-deletion mice in an FD (0.1%) or in a titrated dose (TD, up to 0.8% when drinking volume dropped). Total kidney weight (TKW) and cyst ratio were investigated and compared to non-treated Pkd1-deletion mice. Treatment was started early or late (21 or 42 days postnatal). Results: Water intake was significantly higher throughout the experiment in the TD compared to the FD group. FD treatment that was initiated early reduced TKW and cyst ratio but lost its renoprotective effect later during the experiment. In contrast, TD treatment was able to maintain the renoprotective effect. TD treatment, however, was also associated with a higher early termination rate in comparison with FD treatment. Late start of treatment (FD or TD) did not show a renoprotective effect. Conclusions: Titration of a V2RA aimed to maintain aquaresis at a high level showed a better renoprotective effect compared to FD administration. However, this treatment regimen was poorly tolerated and did not overcome treatment unresponsiveness when started later in the disease