A rat kidney tubule suspension for the study of vasopressin-induced shuttling of AQP2 water channels

2002 ◽  
Vol 283 (5) ◽  
pp. F1160-F1166 ◽  
Author(s):  
Stephen Shaw ◽  
David Marples
Keyword(s):  
Plasma Membrane ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Primary Cultures ◽  
Water Channels ◽  
Apical Plasma Membrane ◽  
Cellular Mechanisms ◽  
Principal Cells ◽  
Microtubule Disruption ◽  
Osmotic Water

AVP increases the osmotic water permeability of renal collecting ducts by inducing the translocation of specific aquaporin-2 (AQP2) water channels from cytoplasmic vesicles to the apical plasma membrane of the principal cells. Here, we report a novel inner medullary tubule suspension for the study of this phenomenon that overcomes some of the drawbacks faced by present techniques; both primary cultures of inner medullary collecting duct cells and cell lines expressing AQP2 show aberrant trafficking and/or signaling pathways. The tubule suspensions were prepared by proteolytic digestion of inner medullas dissected from freshly isolated rat kidneys. After drug treatment, cellular distribution of AQP2 was determined by membrane fractionation and Western blotting or by immunocytochemistry. Treatment of suspensions with 1 nM AVP caused redistribution of AQP2 to the apical plasma membrane of the principal cells, a process inhibited by microtubule disruption or PKA inhibition. We conclude that this method provides a valuable new approach to the study of the cellular mechanisms involved in the response of the collecting duct to AVP.

Immunocytochemical localization of Na+ channels in rat kidney medulla

1989 ◽  
Vol 256 (2) ◽  
pp. F366-F369 ◽  
Author(s):  
D. Brown ◽  
E. J. Sorscher ◽  
D. A. Ausiello ◽  
D. J. Benos
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Apical Plasma Membrane ◽  
Na Channel ◽  
Thick Ascending Limb ◽  
Na Channels ◽  
Kidney Medulla ◽  
Principal Cells

Amiloride-sensitive Na+ channels were localized in semithin frozen sections of rat renal medullary collecting ducts, using polyclonal antibodies directed against purified bovine kidney Na+ channel protein. The apical plasma membrane of collecting duct principal cells was heavily stained by indirect immunofluorescence, whereas intercalated cells were negative. Basolateral plasma membranes of both cell types were unstained, as were subapical vesicles in the cytoplasm of these cells. In the thick ascending limb of Henle, some scattered granular fluorescence was seen in the cytoplasm and close to the apical pole of epithelial cells, suggesting the presence of antigenic sites associated with some membrane domains in these cells. No staining was detected in thin limbs of Henle, or in proximal tubules in the outer medulla. These results show that amiloride-sensitive sodium channels are located predominantly on the apical plasma membrane of medullary collecting duct principal cells, the cells that are involved in Na+ homeostasis in this region of the kidney.

scholarly journals Apical endosomes isolated from kidney collecting duct principal cells lack subunits of the proton pumping ATPase.

1992 ◽  
Vol 119 (1) ◽  
pp. 111-122 ◽  
Author(s):  
I Sabolic ◽  
F Wuarin ◽  
L B Shi ◽  
A S Verkman ◽  
D A Ausiello ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Proton Pump ◽  
Transmembrane Domain ◽  
Collecting Duct ◽  
Water Channels ◽  
Proton Pumping ◽  
Apical Plasma Membrane ◽  
Principal Cells ◽  
Kidney Collecting Duct ◽  
Early Endosomes

Endocytic vesicles that are involved in the vasopressin-stimulated recycling of water channels to and from the apical membrane of kidney collecting duct principal cells were isolated from rat renal papilla by differential and Percoll density gradient centrifugation. Fluorescence quenching measurements showed that the isolated vesicles maintained a high, HgCl2-sensitive water permeability, consistent with the presence of vasopressin-sensitive water channels. They did not, however, exhibit ATP-dependent luminal acidification, nor any N-ethylmaleimide-sensitive ATPase activity, properties that are characteristic of most acidic endosomal compartments. Western blotting with specific antibodies showed that the 31- and 70-kD cytoplasmically oriented subunits of the vacuolar proton pump were not detectable in these apical endosomes from the papilla, whereas they were present in endosomes prepared in parallel from the cortex. In contrast, the 56-kD subunit of the proton pump was abundant in papillary endosomes, and was localized at the apical pole of principal cells by immunocytochemistry. Finally, an antibody that recognizes the 16-kD transmembrane subunit of oat tonoplast ATPase cross-reacted with a distinct 16-kD band in cortical endosomes, but no 16-kD band was detectable in endosomes from the papilla. This antibody also recognized a 16-kD band in affinity-purified H+ ATPase preparations from bovine kidney medulla. Therefore, early endosomes derived from the apical plasma membrane of collecting duct principal cells fail to acidify because they lack functionally important subunits of a vacuolar-type proton pumping ATPase, including the 16-kD transmembrane domain that serves as the proton-conducting channel, and the 70-kD cytoplasmic subunit that contains the ATPase catalytic site. This specialized, non-acidic early endosomal compartment appears to be involved primarily in the hormonally induced recycling of water channels to and from the apical plasma membrane of vasopressin-sensitive cells in the kidney collecting duct.

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.

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.

Endocytosis of water channels in rat kidney: cell specificity and correlation with in vivo antidiuresis

1990 ◽  
Vol 259 (6) ◽  
pp. C920-C932 ◽  
Author(s):  
W. I. Lencer ◽  
D. Brown ◽  
D. A. Ausiello ◽  
A. S. Verkman
Keyword(s):  
Water Permeability ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Water Channel ◽  
Water Channels ◽  
Intercalated Cells ◽  
Principal Cells ◽  
Osmotic Water ◽  
Principal And Intercalated Cells

Vasopressin action in the renal collecting duct is believed to be mediated by the cycling of water channels in principal and, possibly, intercalated cells. We used 6-carboxyfluorescein (6-CF) or fluorescein-labeled dextran (FITC-dextran) to determine the location and water permeability of endocytic vesicles from papilla and inner stripe of Brattleboro rats in different states of diuresis. Fifteen minutes after FITC-dextran infusion, fluorescent vesicles were concentrated at the apical pole of principal and intercalated cells. The osmotic water permeability (Pf) of these endosomes was measured by fluorescence quenching. In papillary endosomes, Pf was high (0.04 +/- 0.004 cm/s) when rats were in physiological states of antidiuresis or after treatment with vasopressin, 1-desamino-8-D-arginine vasopressin (DDAVP), or oxytocin; endosomes isolated from these regions of untreated animals had a low Pf. The number of papillary endosomes with high Pf increased with increasing doses of DDAVP. Endosomes from the inner stripe also had a high Pf only after vasopressin treatment. Confocal microscopy of sections of papilla showed that vasopressin significantly increased endocytosis in principal cells but had no effect on intercalated cells. Our data demonstrate that the bulk of fluorescently labeled vesicles from the papilla originate from the apical membrane of principal cells and contain water channels in their limiting membrane only when the rats are in physiological states of antidiuresis. In contrast, the majority of endocytosis in intercalated cells is not involved in water channel recycling.

Immunoelectron microscopic localization of NBC3 sodium-bicarbonate cotransporter in rat kidney

2000 ◽  
Vol 278 (2) ◽  
pp. F327-F336 ◽  
Author(s):  
Tae-Hwan Kwon ◽  
Alexander Pushkin ◽  
Natalia Abuladze ◽  
Søren Nielsen ◽  
Ira Kurtz
Keyword(s):  
Plasma Membrane ◽  
Immunoelectron Microscopy ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Type A ◽  
Apical Plasma Membrane ◽  
Type B ◽  
Principal Cells ◽  
Connecting Tubule ◽  
Basolateral Plasma Membrane

In the present study, we produced a rabbit peptide-derived polyclonal COOH-terminal antibody that selectively recognizes NBC3, to determine the cellular and subcellular localization of NBC3 in rat kidney, using immunocytochemistry and immunoelectron microscopy. Immunocytochemistry with cryostat sections and semithin cryosections revealed specific staining of intercalated cells (ICs) in the connecting tubule and in cortical, outer medullary, and initial inner medullary collecting ducts. In the connecting tubule and in the cortical and medullary collecting duct, the labeling was associated with both type A and type B ICs. In type A ICs, labeling was confined to the apical and subapical domains, whereas in type B ICs, basal domains were exclusively labeled. In contrast, collecting duct principal cells were consistently unlabeled, and this was confirmed using anti-aquaporin-2 antibodies, which labeled principal cells in parallel semithin cryosections. Glomeruli, proximal tubules, descending thin limbs, ascending thin limbs, thick ascending limbs, distal convoluted tubules, and vascular structures were unlabeled. For immunoelectron microscopy, tissue samples were freeze-substituted, and immunolabeling was performed on ultrathin Lowicryl HM20 sections. Immunoelectron microscopy demonstrated that NBC3 labeling was very abundant in the apical plasma membrane, in intracellular vesicles, and in tubulocisternal profiles in the subapical domains of type A ICs. In type B ICs, NBC3 was mainly present in the basolateral plasma membrane. Immunolabeling controls using peptide-absorbed antibody were consistently negative. In conclusion, NBC3 is highly abundant in the apical plasma membrane of type A ICs and in the basolateral plasma membrane of type B ICs. This suggests that NBC3 plays an important role in modulating bicarbonate transport in the connecting tubule and collecting duct.

Localization and regulation of PKA-phosphorylated AQP2 in response to V2-receptor agonist/antagonist treatment

2000 ◽  
Vol 278 (1) ◽  
pp. F29-F42 ◽  
Author(s):  
Birgitte Mønster Christensen ◽  
Marina Zelenina ◽  
Anita Aperia ◽  
Søren Nielsen
Keyword(s):  
Plasma Membrane ◽  
Immunoelectron Microscopy ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Fold Increase ◽  
Apical Plasma Membrane ◽  
Complete Disappearance ◽  
Vasopressin Secretion ◽  
V2 Receptor ◽  
Intracellular Vesicles

Phosphorylation of Ser256, in a PKA consensus site, in AQP2 (p-AQP2) appears to be critically involved in the vasopressin-induced trafficking of AQP2. In the present study, affinity-purified antibodies that selectively recognize AQP2 phosphorylated at Ser256 were developed. These antibodies were used to determine 1) the subcellular localization of p-AQP2 in rat kidney and 2) changes in distribution and/or levels of p-AQP2 in response to [desamino-Cys1,d-Arg8]vasopressin (DDAVP) treatment or V2-receptor blockade. Immunoelectron microscopy revealed that p-AQP2 was localized in both the apical plasma membrane and in intracellular vesicles of collecting duct principal cells. Treatment of rats with V2-receptor antagonist for 30 min resulted in almost complete disappearance of p-AQP2 labeling of the apical plasma membrane with only marginal labeling of intracellular vesicles remaining. Immunoblotting confirmed a marked decrease in p-AQP2 levels. In control Brattleboro rats (BB), lacking vasopressin secretion, p-AQP2 labeling was almost exclusively present in intracellular vesicles. Treatment of BB rats with DDAVP for 2 h induced a 10-fold increase in p-AQP2 labeling of the apical plasma membrane. The overall abundance of p-AQP2, however, was not increased, as determined both by immunoelectron microscopy and immunoblotting. Consistent with this, 2 h of DDAVP treatment of normal rats also resulted in unchanged p-AQP2 levels. Thus the results demonstrate that AQP2 phosphorylated in Ser256 is present in the apical plasma membrane and in intracellular vesicles and that both the intracellular distribution/trafficking, as well as the abundance of p-AQP2, are regulated via V2 receptors by altering phosphorylation and/or dephosphorylation of Ser256in AQP2.

scholarly journals Polarization of gelsolin and actin binding protein in kidney epithelial cells.

1990 ◽  
Vol 38 (8) ◽  
pp. 1145-1153 ◽  
Author(s):  
J H Hartwig ◽  
D Brown ◽  
D A Ausiello ◽  
T P Stossel ◽  
L Orci
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Water Permeability ◽  
Collecting Duct ◽  
Regulatory Proteins ◽  
Actin Binding ◽  
Apical Plasma Membrane ◽  
Actin Binding Protein ◽  
Principal Cells ◽  
Actin Regulatory Proteins

Vasopressin regulates transepithelial osmotic water permeability in the kidney collecting duct and in target cells in other tissues. In the presence of hormone, water channels are inserted into an otherwise impermeable apical plasma membrane and the apical surface of these cells is dramatically remodelled. Because cytochalasin B and D greatly reduce the response of these cells to vasopressin, actin filaments are believed to participate in the events leading to an increase in transepithelial water permeability. Modulation of the actin filamentous network requires the concerted action of specific actin regulatory proteins, and in the present study we used protein A-gold immunocytochemistry to localize two important molecules, gelsolin and actin binding protein (ABP), in epithelial cells of the kidney inner medulla. Gelsolin and, to a lesser extent, ABP were concentrated in clusters in the apical cell web of principal cells of the collecting duct. Aggregates of gold particles were often associated with the cytoplasmic side of plasma membrane regions forming surface extensions or microvilli. The basolateral plasma membrane was labeled to a much lesser extent than the apical plasma membrane. In the thin limbs of Henle, ABP was localized over the apical plasma membrane in ascending limbs, but gelsolin labeling was weak in these cells. In thin descending limbs, the pattern of labeling was completely reversed, with abundant apical gelsolin labeling but only weak ABP immunolabeling. Although the significance of the distribution of actin regulatory proteins in thin limbs is unknown, the abundance and the predominantly apical polarization of both ABP and gelsolin in principal cells of the collecting duct is consistent with a role of the actin cytoskeleton in the mechanism of vasopressin actin.

Antidiuretic hormone moves membranes

1988 ◽  
Vol 255 (3) ◽  
pp. F375-F382 ◽  
Author(s):  
J. S. Handler
Keyword(s):  
Plasma Membrane ◽  
Antidiuretic Hormone ◽  
Water Permeability ◽  
Apical Membrane ◽  
Collecting Duct ◽  
Toad Bladder ◽  
Cell Swelling ◽  
Apical Plasma Membrane ◽  
Principal Cells ◽  
Particle Aggregates

This review focuses on events at the apical plasma membrane of toad urinary bladder and mammalian collecting duct as their permeability to water changes in response to antidiuretic hormone (ADH) and to its withdrawal. The major marker of the permeability change is observed in freeze-fracture electron microscopy of the apical plasma membrane and consists of a dramatic increase in membrane particle aggregates and, in toad bladder but not in collecting duct, in fused vesicles (aggrephores) that contain particle aggregates in their limiting membranes. Withdrawal of ADH is accompanied by endocytosis at the apical membrane, reflecting retrieval of water-permeable, particle aggregate-containing membrane. Covalent labeling of the external surface of the apical membrane of toad bladder identifies specific proteins that are present in the apical membrane only during the response to ADH. Proteins of the same molecular weights are also present in the retrieved membrane when ADH is withdrawn. Several controversial areas are considered, including the extent of cell swelling as water flows across the epithelium from dilute apical solution to isotonic basal solution, whether only principal cells or principal cells and intercalated cells participate in the water permeability response of the collecting duct, the role of the cytoskeleton in the water permeability response, and the proposed second water permeability barrier that is affected by ADH, but not by adenosine 3',5'-cyclic monophosphate.

scholarly journals Endocytic vesicles from renal papilla which retrieve the vasopressin-sensitive water channel do not contain a functional H+ ATPase.

1990 ◽  
Vol 111 (2) ◽  
pp. 379-389 ◽  
Author(s):  
W I Lencer ◽  
A S Verkman ◽  
M A Arnaout ◽  
D A Ausiello ◽  
D Brown
Keyword(s):  
Plasma Membrane ◽  
Water Permeability ◽  
Collecting Duct ◽  
Water Channel ◽  
Water Channels ◽  
Proton Pumps ◽  
Principal Cells ◽  
Kidney Collecting Duct ◽  
Fluorescence Imaging Microscopy ◽  
Membrane Components

The water permeability of the kidney collecting duct epithelium is regulated by vasopressin (VP)-induced recycling of water channels between an intracellular vesicular compartment and the plasma membrane of principal cells. To test whether the water channels pass through an acidic endosomal compartment during the endocytic portion of this pathway, we measured ATP-dependent acidification of FITC-dextran-labeled endosomes in isolated microsomal fractions from different regions of Brattleboro rat kidneys. Both VP-deficient controls and rat treated with exogenous VP were examined. ATP-dependent acidification was not detectable in endosomes containing water channels from distal papilla (osmotic water permeability Pf = 0.038 +/- 0.004 cm/s). In contrast, the addition of ATP resulted in a strong acidification of renal cortical endosomes (pHmin = 5.8, initial rate = 0.18-0.25 pH U/s). Acidification of cortical endosomes was reversed with nigericin and strongly inhibited by N-ethyl-maleimide. Passive proton permeability was similar and low in both cortical and papillary endosomes from rats treated or not treated with VP. The fraction of labeled endosomes present in microsomal preparations was determined by fluorescence imaging microscopy of microsomes nonspecifically bound to poly-l-lysine-coated coverslips and was 25% in cortical preparations compared to 14% (+VP) and 9% (-VP) in papillary preparations. The fraction of cortical endosomes was enriched 1.5-fold by immunoabsorption to coverslips coated with mAbs against the bovine vacuolar proton pump. In contrast, the fraction of papillary endosomes was depleted more than twofold by immunoabsorption to identical coverslips. Finally, sections of distal papilla stained with antibodies against the lysosomal glycoprotein LGP120 showed that most of the entrapped FITC-dextran did not colocalize with this lysosomal protein. These results demonstrate that vesicles which internalize water channels in kidney collecting duct principal cells lack functional proton pumps, and do not deliver the bulk of their FITC-dextran content to lysosomes. The data suggest that the principal cell contains a specialized nonacidic apical endocytic compartment which functions primarily to recycle membrane components, including water channels, to the plasma membrane.

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