The Swelling-Activated Anion Conductance in the Mouse Renal Inner Medullary Collecting Duct Cell Line mIMCD-K2

2000 ◽  
Vol 177 (1) ◽  
pp. 51-64 ◽  
Author(s):  
S.H. Boese ◽  
M. Glanville ◽  
M.A. Gray ◽  
N.L. Simmons
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Inner Medullary Collecting Duct ◽  
Anion Conductance ◽  
Medullary Collecting Duct

Early transcriptional effects of aldosterone in a mouse inner medullary collecting duct cell line

2003 ◽  
Vol 285 (4) ◽  
pp. F664-F673 ◽  
Author(s):  
Michelle L. Gumz ◽  
Michael P. Popp ◽  
Charles S. Wingo ◽  
Brian D. Cain
Keyword(s):  
Cell Line ◽  
Cellular Response ◽  
Collecting Duct ◽  
Duct Cell ◽  
Immunoblot Analysis ◽  
Tissue Growth ◽  
Long Term Effects ◽  
Acid Base Balance ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney.

H+ secretion is inhibited by clostridial toxins in an inner medullary collecting duct cell line

1997 ◽  
Vol 273 (6) ◽  
pp. F1054-F1057 ◽  
Author(s):  
Edward A. Alexander ◽  
Theodora Shih ◽  
John H. Schwartz
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Specific Protein ◽  
Proton Pumps ◽  
Renal Epithelial Cell ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct ◽  
Cell Acid

Renal epithelial cell H+secretion is an exocytic-endocytic phenomenon. In the inner medullary collecting duct (IMCD) cell line, which we have utilized as a model of renal epithelial cell acid secretion, we found previously that acidification increased exocytosis and alkalinization increased endocytosis. It is likely, therefore, that the rate of proton secretion is regulated by the membrane insertion and retrieval of proton pumps. There is abundant evidence from studies in the nerve terminal and the chromaffin cell that vesicle docking, membrane fusion, and discharge of vesicular contents (exocytosis) involve a series of interactions among so-called trafficking proteins. The clostridial toxins, botulinum and tetanus, are proteases that specifically inactivate some of these proteins. In these experiments we demonstrated, by immunoblot and immunoprecipitation, the presence in this IMCD cell line of the specific protein targets of these toxins, synaptobrevin/vesicle-associated membrane proteins (VAMP), syntaxin, and synaptosomal-associated protein-25 (SNAP-25). Furthermore, we showed that these toxins markedly inhibit the capacity of these cells to realkalinize after an acid load. Thus these data provide new insight into the mechanism for H+ secretion in the IMCD.

scholarly journals microRNA Regulation of endothelin-1 in an inner medullary collecting duct cell line

Life Sciences ◽  
2013 ◽  
Vol 93 (25-26) ◽  
pp. e37
Author(s):  
Mollie E./INS; Jacobs ◽  
Lauren A./INS; Jeffers ◽  
Amanda K./INS; Welch ◽  
Charles S./INS; Wingo ◽  
Brian D./INS; Cain
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Microrna Regulation ◽  
Endothelin 1 ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

scholarly journals Characterization of anion exchangers in an inner medullary collecting duct cell line.

1998 ◽  
Vol 9 (5) ◽  
pp. 746-754
Author(s):  
G Obrador ◽  
H Yuan ◽  
T M Shih ◽  
Y H Wang ◽  
M A Shia ◽  
...  
Keyword(s):  
Cell Line ◽  
Anion Exchanger ◽  
Collecting Duct ◽  
Basolateral Membrane ◽  
Disulfonic Acid ◽  
Kidney Cortex ◽  
Intercalated Cells ◽  
Rat Stomach ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

Although the inner medullary collecting duct (IMCD) plays a major role in urinary acidification, the molecular identification of many of the specific components of the transport system in this nephron segment are lacking. A cultured line of rat IMCD cells was used to characterize the mediators of cellular HCO3 exit. This cell line functionally resembles alpha-intercalated cells. Physiologic experiments document that HCO3- transport is a reversible, electroneutral, Cl dependent, Na+-independent process. It can be driven by Cl-gradients and inhibited by stilbenes such as 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid. Immunohistochemical analysis, using a rabbit polyclonal antibody against the carboxy-terminal 12 amino acids of anion exchanger 1 (AE1), revealed a distribution of immunoreactive protein that is consistent with a basolateral localization of AE in cultured cells and in alpha-intercalated cells identified in sections of rat kidney cortex. Immunoblot revealed two immunoreactive bands (approximately 100 and 180 kD in size) in membranes from cultured IMCD cells, rat renal medulla, and freshly isolated IMCD cells. The mobility of the lower molecular weight band was similar to that of AE1 in red blood cell ghosts and kidney homogenate and therefore probably represents AE1. The mobility of the 180-kD band is similar to that for rat stomach and kidney AE2 and therefore probably represents AE2. Selective biotinylation of the apical or basolateral membrane proteins in cultured IMCD cells revealed that both AE1 and AE2 are polarized to the basolateral membrane. Northern blot analysis documented the expression of mRNA for AE1 and AE2 but not AE3. Furthermore, the cDNA sequence of AE1 and AE2 expressed by these cells was found to be virtually identical to that reported for kidney AE1 and rat stomach AE2. It is concluded that this cultured line of rat IMCD cells expresses two members of the anion exchanger gene family, AE1 and AE2, and both of these exchangers probably mediate the electroneutral Cl--dependent HCO3-transport observed in this cell line.

Apical ammonia transport by the mouse inner medullary collecting duct cell (mIMCD-3)

2005 ◽  
Vol 289 (2) ◽  
pp. F347-F358 ◽  
Author(s):  
Mary E. Handlogten ◽  
Seong-Pyo Hong ◽  
Connie M. Westhoff ◽  
I. David Weiner
Keyword(s):  
Apical Membrane ◽  
Collecting Duct ◽  
Duct Cell ◽  
Transport Activity ◽  
Inner Medullary Collecting Duct ◽  
Transporter Family ◽  
Ammonia Transport ◽  
Medullary Collecting Duct ◽  
Permeable Support ◽  
Exchange Activity

The collecting duct is the primary site of urinary ammonia secretion; the current study determines whether apical ammonia transport in the mouse inner medullary collecting duct cell (mIMCD-3) occurs via nonionic diffusion or a transporter-mediated process and, if the latter, presents the characteristics of this apical ammonia transport. We used confluent cells on permeable support membranes and examined apical uptake of the ammonia analog [14C]methylammonia ([14C]MA). mIMCD-3 cells exhibited both diffusive and saturable, transporter-mediated, nondiffusive apical [14C]MA transport. Transporter-mediated [14C]MA uptake had a Kmof 7.0 ± 1.5 mM and was competitively inhibited by ammonia with a Kiof 4.3 ± 2.0 mM. Transport activity was stimulated by both intracellular acidification and extracellular alkalinization, and it was unaltered by changes in membrane voltage, thereby functionally identifying an apical, electroneutral NH4+/H+exchange activity. Transport was bidirectional, consistent with a role in ammonia secretion. In addition, transport was not altered by Na+or K+removal, not inhibited by luminal K+, and not mediated by apical H+-K+-ATPase, Na+-K+-ATPase, or Na+/H+exchange. Finally, mIMCD-3 cells express the recently identified ammonia transporter family member Rh C glycoprotein (RhCG) at its apical membrane. These studies indicate that the renal collecting duct cell mIMCD-3 has a novel apical, electroneutral Na+- and K+-independent NH4+/H+exchange activity, possibly mediated by RhCG, that is likely to mediate important components of collecting duct ammonia secretion.

Electrogenic sodium absorption and chloride secretion by an inner medullary collecting duct cell line (mIMCD-K2)

1995 ◽  
Vol 268 (2) ◽  
pp. F347-F355 ◽  
Author(s):  
N. L. Kizer ◽  
B. Lewis ◽  
B. A. Stanton
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
T Antigen ◽  
Sodium Absorption ◽  
Sv40 Large T Antigen ◽  
Permanent Cell Line ◽  
Inner Medullary Collecting Duct ◽  
Permanent Cell ◽  
Medullary Collecting Duct

The initial segment of the inner medullary collecting duct (IMCDi) absorbs Na+ by an electrogenic mechanism and plays an important role in regulating the composition and volume of the urine. The purpose of the present study was to establish a permanent cell line derived from the IMCDi, which has the ion transport properties of the IMCDi in vivo. To this end, we isolated IMCD cells from the IMCDi of a mouse, Tg(SV40E) Bri 7, transgenic for the early region of SV40 (large T antigen) and established a permanent cell line, mIMCD-K2, by clonal dilution. mIMCD-K2 cells retain many differentiated characteristics of the IMCDi, including amiloride-sensitive electrogenic Na+ absorption stimulated by nanomolar concentrations of aldosterone. Aldosterone (1.5 x 10(-6) M) increased Na+ absorption from 0.2 +/- 0.1 to 4.6 +/- 1.7 microA/cm2. In addition, the cells secrete Cl- by an electrogenic mechanism at a rate of 0.5 +/- 0.1 microA/cm2. We propose that IMCDi cells either absorb or secrete NaCl depending on NaCl homeostasis. The mIMCD-K2 cell line should be useful for studying the cellular mechanisms responsible for electrogenic Na+ and Cl- transport in the IMCDi.

Adenosine inhibits arginine vasopressin-stimulated chloride secretion in a mouse IMCD cell line (mIMCD-K2)

1995 ◽  
Vol 269 (6) ◽  
pp. F884-F891 ◽  
Author(s):  
B. D. Moyer ◽  
D. E. McCoy ◽  
B. Lee ◽  
N. Kizer ◽  
B. A. Stanton
Keyword(s):  
Cell Line ◽  
Arginine Vasopressin ◽  
Collecting Duct ◽  
Duct Cell ◽  
Chloride Secretion ◽  
Nucleoside Transport ◽  
Intracellular Camp ◽  
Nucleoside Transporter ◽  
Cl Channels ◽  
Medullary Collecting Duct

Previously, we demonstrated that a mouse inner medullary collecting duct cell line (mIMCD-K2) secretes Cl- by an electrogenic mechanism via cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels [N. L. Kizer, B. Lewis, and B. A. Stanton. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F347-F355, 1995; N. L. Kizer, D. Vandorpe, B. Lewis, B. Bunting, J. Russell, and B. A. Stanton. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F854-F861, 1995; D. Vandorpe, N. Kizer, F. Ciampolillo-Bates, B. Moyer, K. Karlson, W. B. Guggino, and B. A. Stanton. Am. J. Physiol. 269 (Cell Physiol. 38): C683-C689, 1995]. The objective of the present study was to determine whether adenosine, and adenosine A1 receptors (A1AR) specifically, regulate electrogenic Cl- secretion (IscCl) in mIMCD-K2 cells. Neither N6-cyclohexyladenosine (CHA), a specific A1AR agonist, nor 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a specific A1AR antagonist, altered basal, unstimulated IscCl in monolayers of mIMCD-K2 cells mounted in Ussing-type chambers. In contrast, DPCPX increased arginine vasopressin (AVP)-stimulated IscCl, an effect that was reversed by CHA. Adenosine deaminase (ADA), which oxidatively deaminates adenosine to inosine, increased AVP-stimulated IscCl. CHA reversed the stimulatory effect of ADA on AVP-stimulated IscCl. These results suggest that adenosine, via A1AR, inhibits AVP-stimulated IscCl. To identify the source(s) of extracellular adenosine, we examined the effects of dipyridamole, an inhibitor of nucleoside transport, and alpha,beta-methyleneadenosine 5'-diphosphate (AOPCP), an inhibitor of ecto-5'-nucleotidase, on AVP-stimulated IscCl. Both compounds increased AVP-stimulated IscCl. CHA reversed the stimulatory effect of dipyridamole and AOPCP on IscCl. Neither ADA nor CHA had an effect on 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (CPT-cAMP)-stimulated IscCl. Moreover, U-73122, an inhibitor of phospholipase C, failed to attenuate the increase in AVP-stimulated IscCl elicited by dipyridamole and AOPCP or the decrease in AVP-stimulated IscCl elicited by CHA. We conclude that adenosine, released by a nucleoside transporter and formed extracellularly by the breakdown of AMP, binds to A1AR, and decreases AVP-stimulated IscCl in mIMCD-K2 cells by reducing intracellular cAMP levels.

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