scholarly journals Discoidan Domain Receptor 1 (DDR1) Tyrosine Kinase is Upregulated in PKD Kidneys But Does Not Play a Role in the Pathogenesis of Polycystic Kidney Disease

2019 ◽  
Author(s):  
Edward Y Skolnik ◽  
Irfana Soomro ◽  
Aram Hong ◽  
Zhai Li ◽  
James Duncan ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Tyrosine Kinase ◽  
Polycystic Kidney Disease ◽  
Kidney Function ◽  
Cancer Progression ◽  
Drug Targets ◽  
Therapeutic Drug ◽  
Polycystic Kidney ◽  
Cyst Growth

Tolvaptan is the only drug approved to slow cyst growth and preserve kidney function in patients with autosomal dominant polycystic kidney disease (ADPKD). However, its limited efficacy combined with significant side effects underscores the need to identify new and safe therapeutic drug targets to slow progression to end stage kidney disease. We identified DDR1 as receptor tyrosine kinase upregulated in vivo in 3 mouse models of ADPKD using a novel mass spectrometry approach to identify kinases upregulated in ADPKD. Previous studies demonstrating critical roles for DDR1 to cancer progression, its potential role in the pathogenesis of a variety of other kidney disease, along with the possibility that DDR1 could provide new insight into how extracellular matrix impacts cyst growth led us to study the role of DDR1 in ADPKD pathogenesis. However, genetic deletion of DDR1 using CRISPR/Cas9 failed to slow cyst growth or preserve kidney function in both a rapid and slow mouse model of ADPKD demonstrating that DDR1 does not play a role in PKD pathogenesis and is thus a not viable drug target. In spite of the negative results, our studies will be of interest to the nephrology community as it will prevent others from potentially conducting similar experiments on DDR1 and reinforces the potential of performing unbiased screens coupled with in vivo gene editing using CRISPR/Cas9 to rapidly identify and confirm new potential drug targets for ADPKD.

scholarly journals A study of sirolimus and mTOR kinase inhibitor in a hypomorphic Pkd1 mouse model of autosomal dominant polycystic kidney disease

2019 ◽  
Vol 317 (1) ◽  
pp. F187-F196 ◽  
Author(s):  
Sara J. Holditch ◽  
Carolyn N. Brown ◽  
Daniel J. Atwood ◽  
Andrew M. Lombardi ◽  
Khoa N. Nguyen ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Mouse Model ◽  
Polycystic Kidney Disease ◽  
Kidney Function ◽  
Autosomal Dominant ◽  
Kinase Inhibitor ◽  
Polycystic Kidney ◽  
Mtor Kinase ◽  
Autosomal Dominant Polycystic Kidney ◽  
Cyst Growth

Autosomal dominant polycystic kidney disease (PKD) is characterized by cyst formation and growth, which are partially driven by abnormal proliferation of tubular cells. Proproliferative mechanistic target of rapamycin (mTOR) complexes 1 and 2 (mTORC1 and mTORC2) are activated in the kidneys of mice with PKD. Sirolimus indirectly inhibits mTORC1. Novel mTOR kinase inhibitors directly inhibit mTOR kinase, resulting in the inhibition of mTORC1 and mTORC2. The aim of the present study was to determine the effects of sirolimus versus the mTOR kinase inhibitor torin2 on cyst growth and kidney function in the Pkd1 p.R3277C ( Pkd1RC/RC) mouse model, a hypomorphic Pkd1 model orthologous to the human condition, and to determine the effects of sirolimus versus torin2 on mTORC1 and mTORC2 signaling in PKD1−/− cells and in the kidneys of Pkd1RC/RC mice. In vitro, both inhibitors reduced mTORC1 and mTORC2 phosphorylated substrates and negatively impacted cellular metabolic activity, as measured by MTT assay. Pkd1RC/RC mice were treated with sirolimus or torin2 from 50 to 120 days of age. Torin2 was as effective as sirolimus in decreasing cyst growth and improving loss of kidney function. Both sirolimus and torin2 decreased phosphorylated S6 protein, phosphorylated eukaryotic translation initiation factor 4E-binding protein 1, phosphorylated Akt, and proliferation in Pkd1RC/RC kidneys. In conclusion, torin2 and sirolimus were equally effective in decreasing cyst burden and improving kidney function and mediated comparable effects on mTORC1 and mTORC2 signaling and proliferation in the Pkd1RC/RC kidney.

scholarly journals The Lonidamine Derivative H2-Gamendazole Reduces Cyst Formation in Polycystic Kidney Disease

2020 ◽  
Author(s):  
Shirin V. Sundar ◽  
Xia Zhou ◽  
Brenda S. Magenheimer ◽  
Gail A. Reif ◽  
Darren P. Wallace ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kidney Disease ◽  
Cell Motility ◽  
Polycystic Kidney Disease ◽  
Short Circuit ◽  
Cyst Formation ◽  
Polycystic Kidney ◽  
Cyst Growth

ABSTRACTAutosomal dominant polycystic kidney disease (ADPKD) is a debilitating renal neoplastic disorder with limited treatment options. It is characterized by the formation of large fluid-filled cysts that develop from kidney tubules through abnormal cell proliferation and cyst-filling fluid secretion driven by cAMP-dependent Cl− secretion. We have examined the effectiveness of the indazole carboxylic acid, H2-gamendazole (H2-GMZ), a derivative of lonidamine, to inhibit these processes and cyst formation using in vitro and in vivo models of ADPKD. H2-GMZ was effective in rapidly blocking forskolin-induced, Cl−-mediated short-circuit currents in human ADPKD cells at 1 μM and it significantly inhibited both cAMP- and EGF-induced proliferation of ADPKD cells with an IC50 of 5-10 μM. Western blot analysis of H2-GMZ-treated ADPKD cells showed decreased phosphorylated ERK and hyperphosphorylated Rb levels. H2-GMZ treatment also decreased ErbB2, Akt, and Cdk4, consistent with inhibition of the chaperone Hsp90, and reduced the levels of the CFTR Cl− channel. H2-GMZ-treated ADPKD cultures contained a higher proportion of smaller cells with fewer and smaller lamellipodia and decreased cytoplasmic actin staining, and they were unable to accomplish wound closure even at low H2-GMZ concentrations, consistent with an alteration in the actin cytoskeleton and decreased cell motility. Studies using mouse metanephric organ cultures showed that H2-GMZ inhibited cAMP-stimulated cyst growth and enlargement. In vivo, H2-GMZ (20mg/kg) was effective in slowing postnatal cyst formation and kidney enlargement in the Pkd1flox/flox:Pkhd1-Cre mouse model. Thus, H2-GMZ treatment decreases Cl− secretion, cell proliferation, cell motility, and cyst growth. These properties, along with its reported low toxicity, suggest that H2-GMZ might be an attractive candidate for treatment of ADPKD.

scholarly journals Cyclin-Dependent Kinase 1 Activity Is a Driver of Cyst Growth in Polycystic Kidney Disease

2020 ◽  
Vol 32 (1) ◽  
pp. 41-51
Author(s):  
Chao Zhang ◽  
Bruno Balbo ◽  
Ming Ma ◽  
Jun Zhao ◽  
Xin Tian ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Effective Means ◽  
Central Component ◽  
Polycystic Kidney ◽  
Double Knockout ◽  
Cyst Cell ◽  
Cyst Growth

BackgroundMutations in PKD1 and PKD2, which encode the transmembrane proteins polycystin-1 and polycystin-2, respectively, cause autosomal dominant polycystic kidney disease (ADPKD). Polycystins are expressed in the primary cilium, and disrupting cilia structure significantly slows ADPKD progression following inactivation of polycystins. The cellular mechanisms of polycystin- and cilia-dependent cyst progression in ADPKD remain incompletely understood.MethodsUnbiased transcriptional profiling in an adult-onset Pkd2 mouse model before cysts formed revealed significant differentially expressed genes (DEGs) in Pkd2 single-knockout kidneys, which were used to identify candidate pathways dysregulated in kidneys destined to form cysts. In vivo studies validated the role of the candidate pathway in the progression of ADPKD. Wild-type and Pkd2/Ift88 double-knockout mice that are protected from cyst growth served as controls.ResultsThe RNASeq data identified cell proliferation as the most dysregulated pathway, with 15 of 241 DEGs related to cell cycle functions. Cdk1 appeared as a central component in this analysis. Cdk1 expression was similarly dysregulated in Pkd1 models of ADPKD, and conditional inactivation of Cdk1 with Pkd1 markedly improved the cystic phenotype and kidney function compared with inactivation of Pkd1 alone. The Pkd1/Cdk1 double knockout blocked cyst cell proliferation that otherwise accompanied Pkd1 inactivation alone.ConclusionsDysregulation of Cdk1 is an early driver of cyst cell proliferation in ADPKD due to Pkd1 inactivation. Selective targeting of cyst cell proliferation is an effective means of slowing ADPKD progression caused by inactivation of Pkd1.

scholarly journals In vitro 3D phenotypic drug screen identifies celastrol as an effective in vivo inhibitor of polycystic kidney disease

2019 ◽  
Vol 12 (8) ◽  
pp. 644-653 ◽  
Author(s):  
Tijmen H Booij ◽  
Wouter N Leonhard ◽  
Hester Bange ◽  
Kuan Yan ◽  
Michiel Fokkelman ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Genetic Disorder ◽  
Screening Method ◽  
Renal Cysts ◽  
Cyst Formation ◽  
Polycystic Kidney ◽  
Cyst Growth

Abstract 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.

Everolimus Retards Cyst Growth and Preserves Kidney Function in a Rodent Model for Polycystic Kidney Disease

2007 ◽  
Vol 30 (4) ◽  
pp. 253-259 ◽  
Author(s):  
Ming Wu ◽  
Patricia R. Wahl ◽  
Michel Le Hir ◽  
Ying Wäckerle-Men ◽  
Rudolf P. Wüthrich ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Kidney Function ◽  
Rodent Model ◽  
Polycystic Kidney ◽  
Cyst Growth

scholarly journals Overexpression of TGF-β1 induces renal fibrosis and accelerates the decline in kidney function in polycystic kidney disease

2020 ◽  
Vol 319 (6) ◽  
pp. F1135-F1148
Author(s):  
Yan Zhang ◽  
Yuqiao Dai ◽  
Archana Raman ◽  
Emily Daniel ◽  
July Metcalf ◽  
...  
Keyword(s):  
Renal Function ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Kidney Function ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Combined Therapy ◽  
Polycystic Kidney ◽  
Tgf Β1 ◽  
Cyst Growth

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the presence of numerous fluid-filled cysts, extensive fibrosis, and the progressive decline in kidney function. Transforming growth factor-β1 (TGF-β1), an important mediator for renal fibrosis and chronic kidney disease, is overexpressed by cystic cells compared with normal kidney cells; however, its role in PKD pathogenesis remains undefined. To investigate the effect of TGF-β1 on cyst growth, fibrosis, and disease progression, we overexpressed active TGF-β1 specifically in collecting ducts (CDs) of phenotypic normal ( Pkd1RC/+) and Pkd1RC/RC mice. In normal mice, CD-specific TGF-β1 overexpression caused tubule dilations by 5 wk of age that were accompanied by increased levels of phosphorylated SMAD3, α-smooth muscle actin, vimentin, and periostin; however, it did not induce overt cyst formation by 20 wk. In Pkd1RC/RC mice, CD overexpression of TGF-β1 increased cyst epithelial cell proliferation. However, extensive fibrosis limited cyst enlargement and caused contraction of the kidneys, leading to a loss of renal function and a shortened lifespan of the mice. These data demonstrate that TGF-β1-induced fibrosis constrains cyst growth and kidney enlargement and accelerates the decline of renal function, supporting the hypothesis that a combined therapy that inhibits renal cyst growth and fibrosis will be required to effectively treat ADPKD.

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