Regulation of apical membrane Na+/H+ exchangers NHE2 and NHE3 in an intestinal epithelial cell line C2/bbe

McSwine, Rebbecca L.; Musch, Mark W.; Xie, Chen; Rao, Mangala; Chang, Eun Jae

doi:10.1016/s0016-5085(98)81606-5

Cited by 22 publications

(36 citation statements)

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“…Because existing inhibition curves for HOE-642 consisted of 22 Na ϩ flux experiments with low extracellular sodium (22,28), we performed a dose-response study for the inhibition of HOE-642 on acid-activated Na ϩ /H ϩ exchange under 120 mM extracellular Na ϩ . (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The rationale of the experiments was the following. If the chosen concentration of 1 M HOE-642, found to be selective for NHE1 in 22 Na ϩ flux experiments (28), was indeed fully sufficient for NHE1 inhibition, but not high enough to inhibit NHE2, then a shift of the concentration to 0.7 or 3 M should not cause a change in the percent Na ϩ /H ϩ exchange inhibition. This was indeed the case.…”

Section: Resultsmentioning

confidence: 99%

“…ϩ -dependent changes in pH i to assess NHE activity and not 22 Na ϩ uptake, the presence of Na ϩ conductances does not interfere with our measurements.…”

Section: Namentioning

confidence: 99%

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The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

Bachmann¹,

Riederer²,

Rossmann³

et al. 2004

American Journal of Physiology-Gastrointestinal and Liver Physi

137

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The Na+/H+ exchanger isoform NHE2 is highly expressed in the intestinal tract, but its physiological role has remained obscure. The aim of this study was to define its expression, location, and regulatory properties in murine colon and to look for the compensatory changes in NHE2 (−/−) colon that allow normal histology and absorptive function. To this end, we measured murine proximal colonic surface and crypt cell NHE1, NHE2, and NHE3 expression levels, transport rates in response to acid, hyperosmolarity and cAMP in murine proximal colonic crypts, as well as changes in transcript levels and acid-activated NHE activity in NHE2 (−/−) crypts. We found that NHE2 was expressed most abundantly in crypts, NHE1 equally in crypts and surface cells, and NHE3 much stronger in surface cells. NHE2, like NHE1, was activated by low intracellular pH (pHi), hyperosmolarity, and cAMP, whereas NHE3 was activated only by low pHi. Crypts isolated from NHE2 (−/−) mice displayed increased acid-activated NHE1- and NHE3-attributable Na+/H+ exchange activity, no change in NHE1 expression, and NHE3 expression levels twice as high as in normal littermates. No change in cellular ultrastructure was found in NHE2 (−/−) colon. Our results demonstrate high NHE2 expression in the crypts and suggest a role for NHE2 in cryptal pHi and volume homeostasis.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

Bachmann¹,

Riederer²,

Rossmann³

et al. 2004

American Journal of Physiology-Gastrointestinal and Liver Physi

137

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“…Cyclic GMP is reported to inhibit Na/K/2Cl transport in rabbit cardiomyocytes (Clemo and Baumgarten, 1995;Lew et al, 1997) and HeLa cells (Kort and Koch, 1990). The nucleotide is known to inhibit Na/H exchange in renal proximal tubules (Roczniak and Burns, 1996), small intestine (Fawcus et al, 1997), rat mesangial cells (Schulte et al, 1999) and in epithelial cell lines such as Caco-2 (Gill et al, 2002) and human intestinal C2/bbe (McSwine et al, 1998). Accordingly, a fourth hypothesis regarding the mechanism of action of ADF and cGMP proposes the inhibition of Na/H exchange transport and Na/K/2Cl cotransport.…”

Section: Inhibition Of Electroneutral Transport Systemsmentioning

confidence: 99%

The mechanism of action of the antidiuretic peptide Tenmo ADFa in Malpighian tubules ofAedes aegypti

Massaro

Lee

Patel

et al. 2004

Journal of Experimental Biology

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“…Because of these features, Caco-2 cells have been deployed to study NHE3 regulation; however, Caco-2 cells have several limitations, including a high degree of heterogeneity leading to the nonuniformity in NHE3 activity, low transfection efficiency, and slow rates of cell proliferation (14). A clonal variant of Caco-2 cells, Caco-2bbe, has been used, but as for Caco-2 cells, the endogenous level of NHE3 in Caco-2bbe cells is either low or undetected, and the usefulness of the Caco-2bbe clone is largely limited to the characterization of transfected NHE3 (20,21). Alternatively, rat intestinal epithelial IEC-6 has been used, but these cells primarily express NHE1 and lack the endogenous expression of NHE3 (35).…”

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confidence: 99%

Human intestinal epithelial cell line SK-CO15 is a new model system to study Na⁺/H⁺exchanger 3

Yoo

Yanda

et al. 2012

American Journal of Physiology-Gastrointestinal and Liver Physi

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cell line represents absorptive polarized intestinal epithelial cells that express multiple forms of Na ϩ /H ϩ exchanger (NHE) in their plasma membranes. Caco-2 cells express the major apical NHE isoform NHE3, but low NHE3 expression together with inefficient transfection often hamper intended studies. In this study, we examined whether SK-CO15 cells could be used to study NHE3 regulation. SK-CO15 cells grown on Transwell inserts developed polarized epithelial cells with microvilli. The transfection efficiency of SK-CO15 cells was markedly higher compared with Caco-2 cells, an advantage in gene transfer and knockout. SK-CO15 cells expressed NHE1, NHE2, and NHE3. NHE3 expression was significantly greater in these cells than Caco-2, and NHE3 comprised more than half of total NHE activity. Apical expression of NHE3 in SK-CO15 cells was confirmed by confocal immunofluorescence and surface biotinylation. NHE regulatory factors NHERF1 and NHERF2, which are important for regulation of NHE3 activity, were expressed in these cells. Stimulatory response of NHE3 in SK-CO15 cells was assessed by dexamethasone and lysophosphatidic acid (LPA). Treatment with dexamethasone for 24 -48 h increased NHE3 expression and activity. Similarly to Caco-2 cells, SK-CO15 cells lacked the expression of the LPA receptor LPA 5, but exogenous expression of LPA5 resulted in acute stimulation of NHE3. Forskolin acutely inhibited NHE3 activity in SK-CO15 cells, further attesting the validity of these cells. We conclude that SK-CO15 cells with the amenity for transfection and high endogenous NHE3 expression are a new and better cell model for NHE3 regulatory investigation than widely used Caco-2 cells.intestine; epithelia POLARIZED INTESTINAL EPITHELIAL cells form an interface separating the internal from external environments and maintain homeostasis between intestinal lumen and the body interior. The plasma membranes of polarized epithelial cells are divided into apical and basolateral domains with asymmetric distribution of cytoplasmic organelles by vectorial sorting mechanisms (27). Na ϩ /H ϩ exchange is a major route of Na ϩ absorption in the small intestine and colon (9). Intestinal epithelial cells express multiple forms of Na ϩ /H ϩ exchangers (NHEs; Slc9a) among which the type 3, NHE3 (Slc9a3), is the primary brush-border NHE. The functions and mechanisms of NHE3 regulation by hormones and growth factors have been investigated since its cloning in the early 1990s using several cell model systems. Among these, PS120 Chinese hamster lung fibroblasts and AP1 Chinese hamster ovarian cells provide an ideal cell system for reductionist approach to characterize NHEs (26, 28). However, the nonepithelial origins of PS120 and AP1 cells often led to question the physiological validity of the findings. Originated from human intestines, T84 and HT29 human colon carcinoma epithelial cell lines are not suitable, as these cells represent secretory crypt epithelial cells (5, 6). The Caco-2 human adenocarcinoma cell line, on the other hand, express severa...

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Regulation of apical membrane Na+/H+ exchangers NHE2 and NHE3 in an intestinal epithelial cell line C2/bbe

Cited by 22 publications

References 0 publications

The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

The mechanism of action of the antidiuretic peptide Tenmo ADFa in Malpighian tubules ofAedes aegypti

Human intestinal epithelial cell line SK-CO15 is a new model system to study Na⁺/H⁺exchanger 3

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Regulation of apical membrane Na+/H+ exchangers NHE2 and NHE3 in an intestinal epithelial cell line C2/bbe

Cited by 22 publications

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The Na+/H+exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

The Na+/H+exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

The mechanism of action of the antidiuretic peptide Tenmo ADFa in Malpighian tubules ofAedes aegypti

Human intestinal epithelial cell line SK-CO15 is a new model system to study Na+/H+exchanger 3

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The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

The Na⁺/H⁺exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation

Human intestinal epithelial cell line SK-CO15 is a new model system to study Na⁺/H⁺exchanger 3