scholarly journals Aurora Kinase A Is Involved in Controlling the Localization of Aquaporin-2 in Renal Principal Cells

2022 ◽  
Vol 23 (2) ◽  
pp. 763
Author(s):  
Sandrine Baltzer ◽  
Timur Bulatov ◽  
Christopher Schmied ◽  
Andreas Krämer ◽  
Benedict-Tilman Berger ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Collecting Duct ◽  
Aurora Kinase ◽  
Stress Fibers ◽  
Aurora A ◽  
Aurora Kinase A ◽  
Principal Cells ◽  
Medullary Collecting Duct ◽  
Kinase A ◽  
Actin Stress Fibers

The cAMP-dependent aquaporin-2 (AQP2) redistribution from intracellular vesicles into the plasma membrane of renal collecting duct principal cells induces water reabsorption and fine-tunes body water homeostasis. However, the mechanisms controlling the localization of AQP2 are not understood in detail. Using immortalized mouse medullary collecting duct (MCD4) and primary rat inner medullary collecting duct (IMCD) cells as model systems, we here discovered a key regulatory role of Aurora kinase A (AURKA) in the control of AQP2. The AURKA-selective inhibitor Aurora-A inhibitor I and novel derivatives as well as a structurally different inhibitor, Alisertib, prevented the cAMP-induced redistribution of AQP2. Aurora-A inhibitor I led to a depolymerization of actin stress fibers, which serve as tracks for the translocation of AQP2-bearing vesicles to the plasma membrane. The phosphorylation of cofilin-1 (CFL1) inactivates the actin-depolymerizing function of CFL1. Aurora-A inhibitor I decreased the CFL1 phosphorylation, accounting for the removal of the actin stress fibers and the inhibition of the redistribution of AQP2. Surprisingly, Alisertib caused an increase in actin stress fibers and did not affect CFL1 phosphorylation, indicating that AURKA exerts its control over AQP2 through different mechanisms. An involvement of AURKA and CFL1 in the control of the localization of AQP2 was hitherto unknown.

scholarly journals Aurora Kinase A as a Diagnostic and Prognostic Marker of Malignant Mesothelioma

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhenying Guo ◽  
Li Shen ◽  
Ningning Li ◽  
Xiaoxiao Wu ◽  
Canming Wang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Prognostic Marker ◽  
Malignant Mesothelioma ◽  
Prognostic Markers ◽  
Kegg Pathway ◽  
Aurora Kinase ◽  
Aurora A ◽  
Hub Genes ◽  
Aurora Kinase A ◽  
Kinase A

BackgroundMalignant mesothelioma (MM) is a highly aggressive cancer with a poor prognosis. Despite the use of several well-known markers, the diagnosis of MM is still challenging in some cases. we applied bioinformatics to identify key genes and screen for diagnostic and prognostic markers of MM.MethodsThe expression profiles of GSE2549 and GSE112154 microarray datasets from the Gene Expression Omnibus database contained 87 cases of MM tissue and 8 cases of normal mesothelial tissue in total. The GEO2R tool was used to detect differentially expressed genes (DEGs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs were performed using DAVID Bioinformatics Resources. The DEGs protein-protein interaction networks were constructed from the STRING database. Cytoscape was used to identify significant modules and hub genes. The GEPIA database was used to explore relationships between hub genes and prognosis of MM. Immunohistochemistry was used to analyze protein expression in tissue microarrays with 47 Chinese MM tissues. Statistical analyses diagnostic and prognostic values.Results346 DEGs were identified: 111 genes upregulated, and 235 downregulated. GO analysis showed that the primary biological processes of these DEGs were cell adhesion, leukocyte migration, and angiogenesis. The main cellular components included the extracellular space, extracellular exosome, and extracellular region. The molecular functions were integrin binding, heparin binding, and calcium ion binding. KEGG pathway analysis showed that DEGs are primarily involved in PPAR signaling pathway, extracellular matrix–receptor interactions, and regulation of lipolysis in adipocytes. Survival analysis showed that seven genes—AURKA, GAPDH, TOP2A, PPARG, SCD, FABP4, and CEBPA—may be potential prognostic markers for MM. Immunohistochemical studies showed that Aurora kinase A (AURKA gene encode, Aurora-A) and GAPDH were highly expressed in MM tissue in comparison with normal mesothelial tissue. Kaplan-Meier analysis confirmed a correlation between Aurora-A protein expression and overall survival but did not confirm a correlation with GAPDH. The receiver operating characteristic curves of Aurora-A protein expression suggested acceptable accuracy (AUC = 0.827; 95% CI [0.6686 to 0.9535]; p = 0.04). The sensitivity and specificity of Aurora-A were 83.33% and 77.78%, respectively.ConclusionAurora-A could be an optimal diagnostic biomarker and a potential prognostic marker for MM.

Stimulation of AQP2 membrane insertion in renal epithelial cells in vitro and in vivo by the cGMP phosphodiesterase inhibitor sildenafil citrate (Viagra)

2005 ◽  
Vol 288 (6) ◽  
pp. F1103-F1112 ◽  
Author(s):  
Richard Bouley ◽  
Nuria Pastor-Soler ◽  
Ori Cohen ◽  
Margaret McLaughlin ◽  
Sylvie Breton ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Collecting Duct ◽  
Sildenafil Citrate ◽  
Membrane Insertion ◽  
Vasopressin Receptor ◽  
Pde5 Inhibitors ◽  
Principal Cells ◽  
Medullary Collecting Duct

Vasopressin-stimulated insertion of the aquaporin 2 (AQP2) water channel into the plasma membrane of kidney collecting duct principal cells is a key event in the urinary concentrating mechanism. The paradigm for vasopressin-receptor signaling involves cAMP-mediated protein kinase A activation, which results in the functionally critical phosphorylation of AQP2 on amino acid serine 256. We previously showed that a parallel cGMP-mediated signaling pathway also leads to AQP2 membrane insertion in AQP2-transfected LLC-PK1 (LLC-AQP2) cells and in outer medullary collecting duct principal cells in situ (Bouley R, Breton S, Sun T, McLaughlin M, Nsumu NN, Lin HY, Ausiello DA, and Brown D. J Clin Invest 106: 1115–1126, 2000). In the present report, we show by immunofluorescence microscopy, and Western blotting of plasma membrane fractions, that 45-min exposure of LLC-AQP2 cells to the cGMP phosphodiesterase type 5 (PDE5) inhibitors sildenafil citrate (Viagra) or 4-{[3',4'-methylene-dioxybenzyl]amino}-6-methoxyquinazoline elevates intracellular cGMP levels and results in the plasma membrane accumulation of AQP2; i.e., they mimic the vasopressin effect. Importantly, our data also show that acute exposure to PDE5 inhibitors for 60 min induces apical accumulation of AQP2 in kidney medullary collecting duct principal cells both in tissue slices incubated in vitro as well as in vivo after intravenous injection of Viagra into rats. These data suggest that AQP2 membrane insertion can be induced independently of vasopressin-receptor activation by activating a parallel cGMP-mediated signal transduction pathway with cGMP PDE inhibitors. These results provide proof-of-principle that pharmacological activation of vasopressin-independent, cGMP signaling pathways could aid in the treatment of those forms of nephrogenic diabetes insipidus that are due to vasopressin-2 receptor dysfunction.

Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney

2001 ◽  
Vol 280 (6) ◽  
pp. F1093-F1106 ◽  
Author(s):  
Henrik Hager ◽  
Tae-Hwan Kwon ◽  
Anna K. Vinnikova ◽  
Shyama Masilamani ◽  
Heddwen L. Brooks ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Confocal Microscopy ◽  
Subcellular Localization ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Apical Plasma Membrane ◽  
Cortical Collecting Duct ◽  
Principal Cells ◽  
Medullary Collecting Duct ◽  
Epithelial Sodium Channel Enac

Epithelial sodium channel (ENaC) subunit (α, β, and γ) mRNA and protein have been localized to the principal cells of the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) in rat kidney. However, the subcellular localization of ENaC subunits in the principal cells of these cells is undefined. The cellular and subcellular localization of ENaC subunits in rat kidney was therefore examined. Immunocytochemistry demonstrated the presence of all three subunits in principal cells of the CNT, CCD, OMCD, and IMCD. In cortex and outer medulla, confocal microscopy demonstrated a difference in the subcellular localization of subunits. α-ENaC was localized mainly in a zone in the apical domains, whereas β- and γ-ENaC were found throughout the cytoplasm. Immunoelectron microscopy confirmed the presence of ENaC subunits in both the apical plasma membrane and intracellular vesicles. In contrast to the labeling pattern seen in cortex, α-ENaC labeling in IMCD cells was distributed throughout the cytoplasm. In the urothelium covering pelvis, ureters, and bladder, immunoperoxidase and confocal microscopy revealed differences the presence of all ENaC subunits. As seen in CCD, α-ENaC was present in a narrow zone near the apical plasma membrane, whereas β- and γ-ENaC were dispersed throughout the cytoplasm. In conclusion, all three subunits of ENaC are expressed throughout the collecting duct (CD), including the IMCD as well as in the urothelium. The intracellular vesicular pool in CD principal cells suggests ENaC trafficking as a potential mechanism for the regulation of Na+ reabsorption.

scholarly journals OTUD6A Is an Aurora Kinase A-Specific Deubiquitinase

2021 ◽  
Vol 22 (4) ◽  
pp. 1936
Author(s):  
Hyo Jin Kim ◽  
Jongchan Kim
Keyword(s):  
Therapeutic Target ◽  
Aurora Kinase ◽  
Regulatory Subunit ◽  
Aurora A ◽  
Aurora Kinases ◽  
Aurora Kinase A ◽  
Cyclin Dependent Kinases ◽  
Human Cancers ◽  
Potential Cancer ◽  
Kinase A

Aurora kinases are serine/threonine kinases required for cell proliferation and are overexpressed in many human cancers. Targeting Aurora kinases has been a therapeutic strategy in cancer treatment. Here, we attempted to identify a deubiquitinase (DUB) that regulates Aurora kinase A (Aurora-A) protein stability and/or kinase activity as a potential cancer therapeutic target. Through pull-down assays with the human DUB library, we identified OTUD6A as an Aurora-A-specific DUB. OTUD6A interacts with Aurora-A through OTU and kinase domains, respectively, and deubiquitinates Aurora-A. Notably, OTUD6A promotes the protein half-life of Aurora-A and activates Aurora-A by increasing phosphorylation at threonine 288 of Aurora-A. From qPCR screening, we identified and validated that the cancer gene CKS2 encoding Cyclin-dependent kinases regulatory subunit 2 is the most upregulated cell cycle regulator when OTUD6A is overexpressed. The results suggest that OTUD6A may serve as a therapeutic target in human cancers.

Axial heterogeneity in basolateral AQP2 localization in rat kidney: effect of vasopressin

2003 ◽  
Vol 284 (4) ◽  
pp. F701-F717 ◽  
Author(s):  
Birgitte Mønster Christensen ◽  
Weidong Wang ◽  
Jørgen Frøkiær ◽  
Søren Nielsen
Keyword(s):  
Plasma Membrane ◽  
Receptor Antagonist ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Apical Plasma Membrane ◽  
Brattleboro Rats ◽  
Short Term ◽  
Principal Cells ◽  
Medullary Collecting Duct

The purpose of the present study was to examine whether there is axial heterogeneity in the basolateral plasma membrane (BLM) localization of AQP2 and whether altered vasopressin action or medullary tonicity affects the BLM localization of AQP2. Immunocytochemistry and immunoelectron microscopy revealed AQP2 labeling of the BLM in connecting tubule (CNT) cells and inner medullary collecting duct (IMCD) principal cells in normal rats and vasopressin-deficient Brattleboro rats. In contrast there was little basolateral AQP2 labeling in cortical (CCD) and outer medullary collecting duct principal cells. Short-term desamino-Cys1, D-Arg8 vasopressin (dDAVP) treatment (2 h) of Brattleboro rats caused no increase in AQP2 labeling of the BLM. In contrast, long-term dDAVP treatment (6 days) of Brattleboro rats caused an increased BLM labeling in CNT, CCD, and IMCD. Treatment of normal rats with V2-receptor antagonist for 60 min caused retrieval of AQP2 from the apical plasma membrane. Moreover, AQP2 labeling of the BLM was unchanged in CNT and IMCD but increased in CCD. In conclusion, there is an axial heterogeneity in the subcellular localization of AQP2 with prominent AQP2 labeling of the BLM in CNT and IMCD. There was no increase in AQP2 labeling of the BLM in response to short-term dDAVP. Moreover, acute V2-receptor antagonist treatment did not cause retrieval of AQP2 from the BLM. In contrast, long-term dDAVP treatment caused a major increase in AQP2 expression in the BLM in CCD.

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