scholarly journals Cux1 promotes cell proliferation and polycystic kidney disease progression in an ADPKD mouse model

2017 ◽  
Vol 313 (4) ◽  
pp. F1050-F1059 ◽  
Author(s):  
Binu Porath ◽  
Safia Livingston ◽  
Erica L. Andres ◽  
Alexandra M. Petrie ◽  
Joshua C. Wright ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kidney Disease ◽  
Mouse Model ◽  
Polycystic Kidney Disease ◽  
Kidney Development ◽  
Kinase Inhibitor ◽  
Regulatory Gene ◽  
Cyst Formation ◽  
Polycystic Kidney ◽  
Collecting Ducts

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common monogenic hereditary disorders in humans characterized by fluid-filled cysts, primarily in the kidneys. Cux1, a cell cycle regulatory gene highly expressed during kidney development, is elevated in the cyst-lining cells of Pkd1 mutant mice, and in human ADPKD cells. However, forced expression of Cux1 is insufficient to induce cystic disease in transgenic mice or to induce rapid cyst formation after cilia disruption in the kidneys of adult mice. Here we report a double mutant mouse model that has a conditional deletion of the Pkd1 gene in the renal collecting ducts together with a targeted mutation in the Cux1 gene (Pkd1CD;Cux1tm2Ejn). While kidneys isolated from newborn Pkd1CD mice exhibit cortical and medullary cysts, kidneys isolated from newborn Pkd1CD;Cux1tm2Ejn−/− mice did not show any cysts. Because Cux1tm2Ejn−/− are perinatal lethal, we evaluated Pkd1CD mice that were heterozygote for the Cux1 mutation. Similar to the newborn Pkd1CD;Cux1tm2Ejn−/− mice, newborn Pkd1CD;Cux1tm2Ejn+/− mice did not show any cysts. Comparison of Pkd1CD and Pkd1CD;Cux1tm2Ejn+/− mice at later stages of development showed a reduction in the severity of PKD in the Pkd1CD;Cux1tm2Ejn+/− mice. Moreover, we observed an increase in expression of the cyclin kinase inhibitor p27, a target of Cux1 repression, in the rescued collecting ducts. Taken together, our results suggest that Cux1 expression in PKD is not directly involved in cystogenesis but promotes cell proliferation required for expansion of existing cysts, primarily by repression of p27.

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.

Restoring multidrug resistance-associated protein 3 attenuates cell proliferation in the polycystic kidney

2015 ◽  
Vol 308 (9) ◽  
pp. F1004-F1011 ◽  
Author(s):  
EunSun Chang ◽  
Eun Young Park ◽  
Yu mi Woo ◽  
Duk-Hee Kang ◽  
Young-Hwan Hwang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Renal Function ◽  
Multidrug Resistance ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Drug Targets ◽  
Cyst Formation ◽  
Polycystic Kidney ◽  
Renal Epithelial Cell

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by abnormal proliferation of renal tubular epithelial cells, resulting in the loss of renal function. Despite identification of the genes responsible for ADPKD, few effective drugs are currently available for the disease. Thus finding additional effective drug targets is necessary. The functions of multidrug- resistance-associated protein 3 (MRP3) have been reported only in the field of drug resistance, and the renal functions of MRP3 are mostly unknown. In this study, we found that MRP3 was significantly downregulated in kidneys of human patients with ADPKD and polycystic kidney disease (PKD) mouse models. Our results suggest that downregulated MRP3 stimulated renal epithelial cell proliferation through the B-Raf/MEK/ERK signaling pathway. In contrast, we found that restoring MRP3 reduced cell proliferation and cystogenesis in vitro. These results suggest that the renal function of MRP3 is related to renal cell proliferation and cyst formation and that restoring MRP3 may be an effective therapeutic approach for PKD.

Steviol retards renal cyst growth through reduction of CFTR expression and inhibition of epithelial cell proliferation in a mouse model of polycystic kidney disease

2014 ◽  
Vol 88 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Chaowalit Yuajit ◽  
Chatchai Muanprasat ◽  
Anna-Rachel Gallagher ◽  
Sorin V. Fedeles ◽  
Suticha Kittayaruksakul ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kidney Disease ◽  
Epithelial Cell ◽  
Mouse Model ◽  
Polycystic Kidney Disease ◽  
Renal Cyst ◽  
Epithelial Cell Proliferation ◽  
Polycystic Kidney ◽  
Cyst Growth

scholarly journals Periostin overexpression in collecting ducts accelerates renal cyst growth and fibrosis in polycystic kidney disease

2018 ◽  
Vol 315 (6) ◽  
pp. F1695-F1707 ◽  
Author(s):  
Archana Raman ◽  
Stephen C. Parnell ◽  
Yan Zhang ◽  
Gail A. Reif ◽  
Yuqiao Dai ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Renal Function ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Tissue Repair ◽  
Rho Gtpase ◽  
Type I ◽  
Polycystic Kidney ◽  
Collecting Ducts ◽  
Cyst Growth

In polycystic kidney disease (PKD), persistent activation of cell proliferation and matrix production contributes to cyst growth and fibrosis, leading to progressive deterioration of renal function. Previously, we showed that periostin, a matricellular protein involved in tissue repair, is overexpressed by cystic epithelial cells of PKD kidneys. Periostin binds αVβ3-integrins and activates integrin-linked kinase (ILK), leading to Akt/mammalian target of rapamycin (mTOR)-mediated proliferation of human PKD cells. By contrast, periostin does not stimulate the proliferation of normal human kidney cells. This difference in the response to periostin is due to elevated expression of αVβ3-integrins by cystic cells. To determine whether periostin accelerates cyst growth and fibrosis, we generated mice with conditional overexpression of periostin in the collecting ducts (CDs). Ectopic CD expression of periostin was not sufficient to induce cyst formation or fibrosis in wild-type mice. However, periostin overexpression in pcy/pcy ( pcy) kidneys significantly increased mTOR activity, cell proliferation, cyst growth, and interstitial fibrosis; and accelerated the decline in renal function. Moreover, CD-specific overexpression of periostin caused a decrease in the survival of pcy mice. These pathological changes were accompanied by increased renal expression of vimentin, α-smooth muscle actin, and type I collagen. We also found that periostin increased gene expression of pathways involved in repair, including integrin and growth factor signaling and ECM production, and it stimulated focal adhesion kinase, Rho GTPase, cytoskeletal reorganization, and migration of PKD cells. These results suggest that periostin stimulates signaling pathways involved in an abnormal tissue repair process that contributes to cyst growth and fibrosis in PKD.

scholarly journals Increased epithelial cell proliferation and abnormal extracellular matrix in rat polycystic kidney disease.

1998 ◽  
Vol 9 (6) ◽  
pp. 937-945 ◽  
Author(s):  
K Ramasubbu ◽  
N Gretz ◽  
S Bachmann
Keyword(s):  
Extracellular Matrix ◽  
Cell Proliferation ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Cyst Formation ◽  
Proliferation Index ◽  
Cystic Degeneration ◽  
Proximal Tubule Cell ◽  
Polycystic Kidney ◽  
Old Rats

Proliferation of renal tubular epithelial cells is considered a major factor leading to cyst formation in human polycystic kidney disease (PKD). The Han:SPRD rat model for inherited PKD permits a close scrutiny, especially for early stages of the disease, and shows numerous similarities to human autosomal dominant PKD (ADPKD). In this study, the exact in vivo proliferation rate in Han:SPRD rat kidneys was evaluated in a cell type-specific manner, using immunohistochemistry with antibody to proliferating cell nuclear antigen (PCNA). The proliferation index (PI; percentage of PCNA-positive cell nuclei) was determined in normal and cystically altered tissue, and a relationship between proliferative activity and alterations in extracellular matrix expression was established using in situ hybridization for collagen I and IV mRNA. Heterozygously affected rats (cy/+) showed strong increases of PI values in cystically altered nephron portions that were mostly derived from proximal tubule. Cell proliferation obviously preceded cyst formation, because early in the progression of the disease, the normal-appearing tubules from PKD kidneys had markedly increased PI values compared with healthy controls (14.1-fold in 3-mo-old rats and 11.9-fold in 12-mo-old rats; P < 0.05), whereas later stages revealed a more generalized cystic degeneration of the nephron, with increases in PI between 14- and 82-fold, depending on the respective category of cystic epithelia. In cysts with a distal phenotype, changes were less pronounced. No significant differences were encountered between the two age groups. Proliferation was also present in interstitial cells, whereas glomeruli were unchanged. Increases in epithelial and interstitial proliferation coincided with an overexpression of matrix compounds. For comparison, changes in homozygously affected rats (cy/cy) showed up to several hundred-fold elevated PI values. These results indicate that in the Han:SPRD model for ADPKD, cystic malformation of the nephron is preceded by and coincides with enhanced epithelial and interstitial cell proliferation. Altered cell-matrix interactions seem to be directly involved in the disruption of epithelial differentiation.

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