Characterization of an in vitro system of human renal papillary collecting duct cells

1990 ◽  
Vol 26 (5) ◽  
pp. 441-446 ◽  
Author(s):  
Anna L. Trifillis ◽  
Myong Won Kahng
Keyword(s):  
Collecting Duct ◽  
In Vitro System ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells

Is the function of the renal papilla coupled exclusively to an anaerobic pattern of metabolism?

1979 ◽  
Vol 236 (5) ◽  
pp. F423-F433 ◽  
Author(s):  
J. J. Cohen
Keyword(s):  
Oxidative Metabolism ◽  
Aerobic Glycolysis ◽  
Collecting Duct ◽  
High Rate ◽  
O2 Uptake ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Mitochondrial Oxidative Metabolism

It is widely accepted that in vivo the function of the papilla of the mammalian kidney is supported primarily by anaerobic metabolism. As a result, the major source of energy for support of function in the papilla is considered to be derived from glycolysis. This orientation originates from two concepts: 1) that in vivo the gaseous environment of the papilla has such a low PO2 that O2 availability limits O2 consumption, and 2) that papillary tissue has a high rate of glycolysis when compared with either cortical tissue or extrarenal tissues. It has also been tacitly assumed that papillary tissue has a "low" O2 uptake. Review of the measurements of PO2 of papillary tissue and of urine PO2 indicates that the PO2 of papillary tissue should not limit its aerobic mitochondrial oxidative metabolism. While the rate of aerobic glycolysis in papillary tissue is high, simultaneously papillary tissue has a rate of O2 uptake similar to that of liver and higher than that of muscle. The major (two-thirds) source of energy for papillary tissue in vitro is from O2 uptake. That papillary tissue is not exclusively dependent on glucose for its energy requirements is indicated by the greater stimulation of papillary tissue QO2 by succinate than by glucose. Thus, papillary tissue has both a high aerobic mitochondrial oxidative metabolism and a high aerobic glycolytic metabolism. It is suggested that the mechanism for the high rate of aerobic glycolysis in the presence of an adequate O2 supply is due to the relatively small mass of mitochondria in papillary tissue in relation to the amount of work done by the tissue. As a result of the limited rate of ATP production by the mitochondrial electron transport chain, the phosphorylation state ([ATP]/[ADP][Pi]) is reduced and the cytoplasmic redox state ([NAD+]/[NADH]) of the papillary collecting duct cells also becomes more reduced; changes in both ratios enhance the rate of glycolysis. This limited metabolic capacity of the collecting duct cells may permit an excess volume of solute and water to be excreted during volume expansion diuresis. The metabolic characteristics of the papilla, when compared to cortex, also provide a basis for the observed differences in substrate selectivity of cortex and medulla with respect to utilization of glucose and lactate. The experimental approaches that may provide information bearing on the suggested mechanisms for regulation of papillary metabolism in relation to tubular work functions are indicated.

scholarly journals A Na-K-Cl cotransporter in isolated rat papillary collecting duct cells

1989 ◽  
Vol 36 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Clemens Grupp ◽  
Iris Pavenstädt-Grupp ◽  
R. Willi Grunewald ◽  
Christopher Bevan ◽  
John B. Stokes ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells ◽  
Isolated Rat

Sugar transport in isolated rat kidney papillary collecting duct cells

1988 ◽  
Vol 413 (1) ◽  
pp. 32-37 ◽  
Author(s):  
R. W. Grunewald ◽  
R. K. H. Kinne
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Sugar Transport ◽  
Isolated Rat Kidney ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells ◽  
Isolated Rat

Bradykinin modulates focal adhesions and induces stress fiber remodeling in renal papillary collecting duct cells

2008 ◽  
Vol 294 (3) ◽  
pp. F603-F613 ◽  
Author(s):  
María Gabriela Márquez ◽  
María del Carmen Fernández-Tome ◽  
Nicolás Octavio Favale ◽  
Lucila Gisele Pescio ◽  
Norma Beatriz Sterin-Speziale
Keyword(s):  
Cultured Cells ◽  
Cell Attachment ◽  
Average Length ◽  
Collecting Duct ◽  
Focal Adhesions ◽  
Axial Ratio ◽  
Cytoskeleton Organization ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells

Focal adhesions (FAs) are specialized regions of cell attachment to the extracellular matrix. Previous works have suggested that bradykinin (BK) can modulate cell-matrix interaction. In the present study, we used a physiological cellular model to evaluate the potential role of BK in modulating FAs and stress fibers. We performed a quantitative morphometric analysis of FAs in primary cultured rat renal papillary collecting duct cells, which included size, axial ratio (shape), and average length. After 1, 5, or 10 min of incubation with BK, cultured cells were immunostained and analyzed by confocal microscopy. Although the shape of FAs was not altered, BK induced a decrease in the number of vinculin-stained FAs per cell, and a decrease in both their size and their average length, but not in talin-containing FAs, thus suggesting that BK could be inducing a restructuring of FAs. BK also induced a remodeling of the actin filament assemblies rather than their dissipation. Since we have previously demonstrated that BK stimulates activation of PLCβ in rat renal papillae, we attempted to determine whether BK can modulate FA restructuring by this mechanism, by pretreating cultured cells with the PLCβ inhibitor U73122. The present study, performed under physiological conditions with cells that were not genetically manipulated, provides new experimental evidence supporting the notion that the intrarenal hormone BK modulates FAs and actin cytoskeleton organization through a mechanism that involves the activation of PLCβ. We propose this finding as a novel mechanism for BK modulation of tubular collecting duct function.

Detection of a Na+-H+ antiporter in cultured rat renal papillary collecting duct cells

1987 ◽  
Vol 253 (5) ◽  
pp. F889-F895 ◽  
Author(s):  
S. M. Wall ◽  
S. Muallem ◽  
J. A. Kraut
Keyword(s):  
Collecting Duct ◽  
Sodium Concentration ◽  
Significant Rise ◽  
Fluorescent Signal ◽  
Tetramethylammonium Chloride ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells ◽  
High Concentrations ◽  
Extracellular Sodium

To examine whether Na+-dependent H+ transport is present in the papillary collecting duct, changes in intracellular pH (pHi) were evaluated in cultured papillary collecting duct cells acidified to a pHi of 6.3 and then placed into Na+-free or Na+-containing solutions. pHi was determined from changes in the fluorescent signal of the pH-sensitive dye BCECF. pHi did not change significantly when cells were placed in tetramethylammonium chloride- or KCl-containing solutions; however, a significant rise in pHi occurred when acid-loaded cells were placed in solutions containing 140 mM NaCl. The Na+-dependent rise in pHi was blocked by high concentrations of amiloride, but was not affected by alterations in membrane potential across the cell. The rate of rise in pHi was a function of extracellular sodium concentration with a Km for Na+ of 30 +/- 12 mM (n = 6). The properties of this Na+-dependent H+ efflux supports the presence of a Na+-H+ antiporter in the papillary collecting duct.

scholarly journals AMPK phosphorylation of the β1Pix exchange factor regulates the assembly and function of an ENaC inhibitory complex in kidney epithelial cells

2019 ◽  
Vol 317 (6) ◽  
pp. F1513-F1525 ◽  
Author(s):  
Pei-Yin Ho ◽  
Hui Li ◽  
Lei Cheng ◽  
Vivek Bhalla ◽  
Robert A. Fenton ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Collecting Duct ◽  
Body Volume ◽  
Cortical Collecting Duct ◽  
Exchange Factor ◽  
Ampk Phosphorylation ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
P21 Activated Kinase

The metabolic sensor AMP-activated protein kinase (AMPK) inhibits the epithelial Na+ channel (ENaC), a key regulator of salt reabsorption by the kidney and thus total body volume and blood pressure. Recent studies have suggested that AMPK promotes the association of p21-activated kinase-interacting exchange factor-β1 β1Pix, 14-3-3 proteins, and the ubiquitin ligase neural precursor cell expressed developmentally downregulated protein (Nedd)4-2 into a complex that inhibits ENaC by enhancing Nedd4-2 binding to ENaC and ENaC degradation. Functional β1Pix is required for ENaC inhibition by AMPK and promotes Nedd4-2 phosphorylation and stability in mouse kidney cortical collecting duct cells. Here, we report that AMPK directly phosphorylates β1Pix in vitro. Among several AMPK phosphorylation sites on β1Pix detected by mass spectrometry, Ser71 was validated as functionally significant. Compared with wild-type β1Pix, overexpression of a phosphorylation-deficient β1Pix-S71A mutant attenuated ENaC inhibition and the AMPK-activated interaction of both β1Pix and Nedd4-2 to 14-3-3 proteins in cortical collecting duct cells. Similarly, overexpression of a β1Pix-Δ602–611 deletion tract mutant unable to bind 14-3-3 proteins decreased the interaction between Nedd4-2 and 14-3-3 proteins, suggesting that 14-3-3 binding to β1Pix is critical for the formation of a β1Pix/Nedd4-2/14-3-3 complex. With expression of a general peptide inhibitor of 14-3-3-target protein interactions (R18), binding of both β1Pix and Nedd4-2 to 14-3-3 proteins was reduced, and AMPK-dependent ENaC inhibition was also attenuated. Altogether, our results demonstrate the importance of AMPK-mediated phosphorylation of β1Pix at Ser71, which promotes 14-3-3 interactions with β1Pix and Nedd4-2 to form a tripartite ENaC inhibitory complex, in the mechanism of ENaC regulation by AMPK.

scholarly journals Changes in membrane lipid composition cause alterations in epithelial cell–cell adhesion structures in renal papillary collecting duct cells

2012 ◽  
Vol 1818 (3) ◽  
pp. 491-501 ◽  
Author(s):  
María Gabriela Márquez ◽  
Nicolás Octavio Favale ◽  
Francisco Leocata Nieto ◽  
Lucila Gisele Pescio ◽  
Norma Sterin-Speziale
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Lipid Composition ◽  
Collecting Duct ◽  
Membrane Lipid ◽  
Membrane Lipid Composition ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells ◽  
Cell Cell

scholarly journals Relationship between intracellular ionic strength and expression of tonicity‐responsive genes in rat papillary collecting duct cells

2002 ◽  
Vol 543 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Wolfgang Neuhofer ◽  
Helmut Bartels ◽  
Maria‐L. Fraek ◽  
Franz‐X. Beck
Keyword(s):  
Ionic Strength ◽  
Collecting Duct ◽  
Duct Cells ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells
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