Acidosis‐induced activation of distal nephron principal cells triggers Gdf15 secretion and adaptive proliferation of intercalated cells

The distal nephron is a heterogeneous part of the nephron composed by six different cell types, forming the epithelium of the distal convoluted (DCT), connecting, and collecting duct. To dissect the function of these cells, knockout models specific for their unique cell marker have been created. However, since this part of the nephron develops at the border between the ureteric bud and the metanephric mesenchyme, the specificity of the single cell markers has been recently questioned. Here, by mapping the fate of the aquaporin 2 (AQP2) and Na+-Cl−cotransporter (NCC)-positive cells using transgenic mouse lines expressing the yellow fluorescent protein fluorescent marker, we showed that the origin of the distal nephron is extremely composite. Indeed, AQP2-expressing precursor results give rise not only to the principal cells, but also to some of the A- and B-type intercalated cells and even to cells of the DCT. On the other hand, some principal cells and B-type intercalated cells can develop from NCC-expressing precursors. In conclusion, these results demonstrate that the origin of different cell types in the distal nephron is not as clearly defined as originally thought. Importantly, they highlight the fact that knocking out a gene encoding for a selective functional marker in the adult does not guarantee cell specificity during the overall kidney development. Tools allowing not only cell-specific but also time-controlled recombination will be useful in this sense.

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Cellular distribution of the potassium channel KCNQ1 in normal mouse kidney

AJP Renal Physiology ◽

10.1152/ajprenal.00087.2006 ◽

2007 ◽

Vol 292 (1) ◽

pp. F456-F466 ◽

Cited By ~ 31

Author(s):

Wencui Zheng ◽

Jill W. Verlander ◽

I. Jeanette Lynch ◽

Melanie Cash ◽

Jiahong Shao ◽

...

Keyword(s):

Collecting Duct ◽

Mouse Kidney ◽

Cellular Heterogeneity ◽

Thick Ascending Limb ◽

Intercalated Cells ◽

Distal Nephron ◽

Rt Pcr ◽

Double Labeling ◽

Cytoplasmic Staining ◽

Principal Cells

Mechanisms of K+ secretion and absorption along the collecting duct are not understood fully. Because KCNQ1 participates in K+ secretion within the inner ear and stomach, distribution of KCNQ1 in mouse kidney was studied using Northern and Western analyses, RT-PCR of isolated tubules, and immunohistochemistry. Northern blots demonstrated KCNQ1 transcripts in whole kidney. RT-PCR showed KCNQ1 mRNA in isolated distal convoluted tubule (DCT), connecting segment (CNT), collecting ducts (CD), and glomeruli. Immunoblots of kidney and stomach revealed a ∼75-kDa protein, the expected mobility for KCNQ1. KCNQ1 was detected by immunohistochemistry throughout the distal nephron and CD. Thick ascending limbs exhibited weak basolateral immunolabel. In DCT and CNT cells, immunolabel was intense and basolateral, although KCNQ1 label was stronger in late than in early DCT. Initial collecting tubule and cortical CD KCNQ1 immunolabel was predominantly diffuse, but many cells exhibited discrete apical label. Double-labeling experiments demonstrated that principal cells, type B intercalated cells, and a few type A intercalated cells exhibited distinct apical KCNQ1 immunolabel. In inner medullary CD, principal cells exhibited distinct basolateral KCNQ1 immunolabel, whereas intercalated cells showed diffuse cytoplasmic staining. Thus KCNQ1 protein is widely distributed in mouse distal nephron and CD, with significant axial and cellular heterogeneity in location and intensity. These findings suggest that KCNQ1 has cell-specific roles in renal ion transport and may participate in K+ secretion and/or absorption along the thick ascending limb, DCT, connecting tubule, and CD.

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Evaluation of cellular plasticity in the collecting duct during recovery from lithium-induced nephrogenic diabetes insipidus

AJP Renal Physiology ◽

10.1152/ajprenal.00152.2012 ◽

2013 ◽

Vol 305 (6) ◽

pp. F919-F929 ◽

Cited By ~ 35

Author(s):

Francesco Trepiccione ◽

Giovambattista Capasso ◽

Søren Nielsen ◽

Birgitte Mønster Christensen

Keyword(s):

Time Course ◽

Morphological Changes ◽

Collecting Duct ◽

Lithium Treatment ◽

Transition Element ◽

Type A ◽

Functional Markers ◽

Intercalated Cells ◽

Anion Exchanger 1 ◽

Principal Cells

The cellular morphology of the collecting duct is altered by chronic lithium treatment. We have previously shown that lithium increases the fraction of type-A intercalated cells and lowers the fraction of principal cells along the collecting duct. Moreover, type-A intercalated cells acquire a long-row distribution pattern along the tubules. In the present study, we show that these morphological changes reverse progressively after discontinuation of lithium and finally disappear after 19 days from lithium suspension. In this time frame we have identified for the first time, in vivo, a novel cellular type positive for both intercalated and principal cells functional markers, as recognized by colabeling with H+-ATPase/aquaporin-4 (AQP4) and anion exchanger-1 (AE-1)/AQP2 and Foxi1/AQP4. This cell type is mainly present after 6 days of lithium washout, and it disappears in parallel with the long-row pattern of the type-A intercalated cells. It usually localizes either in the middle or at the edge of the long-row pattern. Its ultrastructure resembles the intercalated cells as shown both by differential interference contrast and by electron microscopy. The time course of appearance, the localization along the collecting duct, and the ultrastructure suggest that the cells double labeled for principal and intercalated cells markers could represent a transition element driving the conversion of intercalated cells into principal cells.

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Differentiation of renal beta-intercalated cells to alpha-intercalated and principal cells in culture.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.89.12.5487 ◽

1992 ◽

Vol 89 (12) ◽

pp. 5487-5491 ◽

Cited By ~ 66

Author(s):

G. Fejes-Toth ◽

A. Naray-Fejes-Toth

Keyword(s):

Intercalated Cells ◽

Principal Cells ◽

Cells In Culture

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Axial heterogeneity of rabbit cortical collecting duct

AJP Renal Physiology ◽

10.1152/ajprenal.1991.260.4.f498 ◽

1991 ◽

Vol 260 (4) ◽

pp. F498-F505

Author(s):

C. L. Emmons ◽

K. Matsuzaki ◽

J. B. Stokes ◽

V. L. Schuster

Keyword(s):

Cross Sections ◽

Cell Function ◽

Rate Coefficient ◽

Collecting Duct ◽

Lectin Binding ◽

Cell Types ◽

Intercalated Cells ◽

Cortical Collecting Duct ◽

Principal Cells ◽

Inner Cortex

The rabbit cortical collecting duct (CCD) consists of three major cell types: principal cells transport K+, beta-intercalated cells absorb Cl-, and alpha-intercalated cells secrete H+. We used functional and histological methods to assess axial distribution of these cell types along rabbit CCD. In perfused CCDs, lumen-to-bath Rb+ rate coefficient (an index of principal cell K+ transport) was not different in tubules from outer cortex (1 mm from renal surface) compared with those from inner cortex (2 mm from renal surface), suggesting that principal cell function is homogeneous along the CCD. In contrast, Cl- rate coefficient (a measure of beta-intercalated cell function) was twice as high in CCDs from outer compared with inner cortex, suggesting heterogeneity of beta-intercalated cells along the CCD. To further investigate these regional differences, we fixed and embedded kidneys and identified three cell types in CCD cross sections using carbonic anhydrase staining and peanut lectin binding. Comparing tubule cross sections from outer with those from inner cortex, we found no axial difference in the fraction of cells that were either principal cells (64%) or total (lectin binding and nonlectin binding) intercalated cells (36%). However, the lectin-binding intercalated cell subset was significantly increased in outer compared with inner cortex. We conclude that there is not heterogeneity of principal cells along the rabbit CCD; however, beta-cell number and function are increased in outer CCD. Collecting duct heterogeneity begins within the cortical segment.

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Depletion of intercalated cells from collecting ducts of carbonic anhydrase II-deficient (CAR2 null) mice

AJP Renal Physiology ◽

10.1152/ajprenal.1995.269.6.f761 ◽

1995 ◽

Vol 269 (6) ◽

pp. F761-F774 ◽

Cited By ~ 27

Author(s):

S. Breton ◽

S. L. Alper ◽

S. L. Gluck ◽

W. S. Sly ◽

J. E. Barker ◽

...

Keyword(s):

Carbonic Anhydrase ◽

Collecting Duct ◽

Water Channel ◽

Immunofluorescent Staining ◽

Specific Marker ◽

Intercalated Cells ◽

Cortical Collecting Duct ◽

Principal Cells ◽

Collecting Tubules ◽

Deficient Mice

The kidneys of mice (CAR2-null mice) that are genetically devoid of carbonic anhydrase type II (CAII) were screened by immunocytochemistry with antibodies that distinguish intercalated and principal cells. Immunofluorescent localization of the anion exchanger AE1 and of the 56-kDa subunit of the vacuolar H(+)-adenosinetriphosphatase (H(+)-ATPase) was used to identify intercalated cells, while the AQP2 water channel was used as a specific marker for principal cells of the collecting duct. The CAII deficiency of the CAR2-null mice was first confirmed by the absence of immunofluorescent staining of kidney sections exposed to an anti-CAII antibody. Cells positive for AE1 and H(+)-ATPase were common in all collecting duct regions in normal mice but were virtually absent from the inner stripe of the outer medulla and the inner medulla of CAR2-null mice. The number of positive cells was also reduced threefold in the cortical collecting duct of CAR2-null animals compared with normal mice. In parallel, the percentage of AQP2-positive cells was correspondingly increased in the collecting tubules of CAII-deficient mice, whereas the total number of cells per tubule remained unchanged. These results suggest that intercalated cells are severely depleted and are replaced by principal cells in CAII-deficient mice. Quantitative analysis and double staining showed that, in the cortex, both type A and type B intercalated cells are equally affected. Elucidation of the mechanism(s) responsible for this phenotype will be of importance in understanding the origin and development of intercalated cells in the kidney.

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Detection and localization of H+-K+-ATPase isoforms in human kidney

AJP Renal Physiology ◽

10.1152/ajprenal.2001.281.4.f763 ◽

2001 ◽

Vol 281 (4) ◽

pp. F763-F768 ◽

Cited By ~ 32

Author(s):

Jeffrey A. Kraut ◽

Kerstin G. Helander ◽

Herbert F. Helander ◽

Ngozi D. Iroezi ◽

Elizabeth A. Marcus ◽

...

Keyword(s):

Human Kidney ◽

Renal Tissue ◽

Intercalated Cells ◽

Cytoplasmic Staining ◽

Principal Cells ◽

Medullary Tissue ◽

Collecting Ducts ◽

Light Staining ◽

Immunohistochemical Studies ◽

Detection And Localization

An H+-K+-ATPase contributes to hydrogen secretion and potassium reabsorption by the rat and rabbit collecting ducts. Transport of these ions appears to be accomplished by one or both of two isoforms of the H+-K+-ATPase, HKα1 and HKα2, because both isoforms are found in the collecting ducts and transport of hydrogen and potassium is attenuated by exposure to inhibitors of these transport proteins. To evaluate whether an H+-K+-ATPase is present in the human kidney, immunohistochemical studies were performed using normal human renal tissue probed with antibodies directed against epitopes of three of the known isoforms of the H+-K+-ATPase, HKα1, HKα2, and HKα4, and the V-type H+-ATPase. Cortical and medullary tissue probed with antibodies against HKα1 showed cytoplasmic staining of intercalated cells that was less intense than that observed in the parietal cells of normal rat stomach stained with the same antibody. Also, weak immunoreactivity was detected in principal cells of the human collecting ducts. Cortical and medullary tissue probed with antibodies directed against HKα4 revealed weak, diffuse staining of intercalated cells of the collecting ducts and occasional light staining of principal cells. Cortical and medullary tissue probed with antibodies directed against the H+-ATPase revealed staining of intercalated cells of the collecting ducts and some cells of the proximal convoluted tubules. By contrast, no discernible staining was noted with the use of the antibody against HKα2. These data indicate that HKα1 and HKα4 are present in the collecting ducts of the human kidney. In this location, these isoforms might contribute to hydrogen and potassium transport by the kidney.

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Structural-functional relationships along the distal nephron

AJP Renal Physiology ◽

10.1152/ajprenal.1986.250.1.f1 ◽

1986 ◽

Vol 250 (1) ◽

pp. F1-F15 ◽

Cited By ~ 34

Author(s):

K. M. Madsen ◽

C. C. Tisher

Keyword(s):

Atpase Activity ◽

Collecting Duct ◽

Basolateral Membrane ◽

Distal Tubule ◽

Structural Heterogeneity ◽

Apical Plasma Membrane ◽

Thick Ascending Limb ◽

Intercalated Cells ◽

Principal Cells ◽

Functional Relationships

The distal tubule, which includes the thick ascending limb (TAL), the macula densa, and the distal convoluted tubule (DCT), and the collecting duct are structurally heterogeneous, thus reflecting the functional heterogeneity that is also present. As the TAL ascends from medulla to cortex, the surface area of the apical plasma membrane increases while that of the basolateral membrane decreases. The structure of the DCT resembles that of the medullary TAL. An excellent correlation exists between structure, Na-K-ATPase activity, and NaCl reabsorptive capacity in the distal tubule. The collecting duct is subdivided into the initial collecting tubule (ICT), and cortical (CCD), outer medullary (OMCD), and inner medullary (IMCD) collecting ducts. Between the distal tubule and the collecting duct is a transition region termed the connecting segment or connecting tubule (CNT). Considerable structural heterogeneity exists along the collecting duct within the two major cell populations, the intercalated cells and the principal cells. In the CNT, the ICT, and the CCD, potassium loading and mineralocorticoids stimulate Na-K-ATPase activity and cause proliferation of the basolateral membrane of CNT cells and principal cells, thus identifying the cells responsible for mineralocorticoid-stimulated potassium secretion in these regions. Finally, at least two morphologically distinct populations of intercalated cells exist, types A and B. In the rat, type A predominates in the CNT and the OMCD and is believed to be responsible for H+ secretion, at least in the OMCD. Type B predominates in the CCD, where it may be involved in bicarbonate secretion.

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30 YEARS OF THE MINERALOCORTICOID RECEPTOR: Mineralocorticoid receptor and NaCl transport mechanisms in the renal distal nephron

Journal of Endocrinology ◽

10.1530/joe-16-0669 ◽

2017 ◽

Vol 234 (1) ◽

pp. T35-T47 ◽

Cited By ~ 12

Author(s):

Shigeru Shibata

Keyword(s):

Mineralocorticoid Receptor ◽

Current Knowledge ◽

Distal Convoluted Tubule ◽

The Body ◽

Intercalated Cells ◽

Distal Nephron ◽

Electrolyte Disorders ◽

Nacl Transport ◽

Ubiquitin Ligase Complex ◽

Tubule Cells

A key role of aldosterone and mineralocorticoid receptor is to regulate fluid volume and K+ homeostasis in the body by acting on the renal distal nephron. Global responses of the kidney to elevated aldosterone levels are determined by the coordinate action of different constituent tubule cells, including principal cells, intercalated cells and distal convoluted tubule cells. Recent studies on genetic mutations causing aldosterone overproduction have identified the molecules involved in aldosterone biosynthesis in the adrenal gland, and there is also increasing evidence for mechanisms and signaling pathways regulating the balance between renal NaCl reabsorption and K+ secretion, the two major effects of aldosterone. In particular, recent studies have demonstrated that mineralocorticoid receptor in intercalated cells is selectively regulated by phosphorylation, which prevents ligand binding and activation. Moreover, the ubiquitin ligase complex composed of Kelch-like 3 and Cullin 3 acts downstream of angiotensin II and plasma K+ alterations, regulating Na–Cl cotransporter independently of aldosterone in distal convoluted tubule cells. These and other effects are integrated to produce appropriate kidney responses in a high-aldosterone state, and are implicated in fluid and electrolyte disorders in humans. This review summarizes the current knowledge on mechanisms modulating mineralocorticoid receptor and its downstream effectors in the distal nephron.

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