Biophysical properties of epithelial water channels

Parisi, Mario; Amodeo, Gabriela; Capurro, Claudia; Dorr, Ricardo; Ford, Paula; Toriano, Roxana

doi:10.1016/s0301-4622(97)00069-0

Cited by 20 publications

(19 citation statements)

References 59 publications

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“…On the other hand, in LLC-PK1 cells much higher conductances were associated with lower P HYDR values. For both P HYDR and R T , the paracellular route has been previously reported to be the most important one (2,19).…”

Section: Discussionmentioning

confidence: 97%

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Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports

Ozu

Toriano

Capurro

et al. 2005

Braz J Med Biol Res

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T84 is an established cell line expressing an enterocyte phenotype whose permeability properties have been widely explored. Osmotic permeability (P OSM ), hydraulic permeability (P HYDR ) and transportassociated net water fluxes (J W -transp), as well as short-circuit current (I SC ), transepithelial resistance (R T ), and potential difference (∆V T ) were measured in T84 monolayers with the following results: P OSM 1.3 ± 0.1 cm.s -1 x 10 -3 ; P HYDR 0.27 ± 0.02 cm.s -1 ; R T 2426 ± 109 Ω.cm 2 , and ∆V T 1.31 ± 0.38 mV. The effect of 50 µM 5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one (DCEBIO), a "net Cl -secretory agent", on T84 cells was also studied. We confirm the reported important increase in I SC induced by DCEBIO which was associated here with a modest secretory ∆J W -transp. The present results were compared with those reported using the same experimental approach applied to established cell lines originating from intestinal and renal epithelial cells (Caco-2, LLC-PK1 and RCCD-1). No clear association between P HYDR and R T could be demonstrated and high P HYDR values were observed in an electrically tight epithelium, supporting the view that a "water leaky" barrier is not necessarily an "electrically leaky" one. Furthermore, the modest secretory ∆J W -transp was not consistent with previous results obtained with RCCD-1 cells stimulated with vasopressin (absorptive fluxes) or with T84 cells secreting water under the action of Escherichia coli heat stable enterotoxin. We conclude that, while the presence of aquaporins is necessary to dissipate an external osmotic gradient, coupling between water and ion transport cannot be explained by a simple and common underlying mechanism.

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Section: Discussionmentioning

confidence: 97%

“…Two different permeability coefficients of water net fluxes can be measured: osmotic (P OSM ) and hydrostatic (P HYDR ) (2). Moreover, diffusional water permeability can be measured from unidirectional fluxes using tritiated water.…”

Section: Introductionmentioning

confidence: 99%

Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports

Ozu

Toriano

Capurro

et al. 2005

Braz J Med Biol Res

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“…Generally, the driving force of AQP water channels is generated by the combination of trans-epithelial hydrostatic and osmotic pressure. Therefore, the amount of water moving per unit of time and surface is dependent on the osmotic or hydrostatic gradient and the AQP concentration on the epithelium (Parisi et al, 1997). AQP-1, -2, and -3 expression in the kidney is known to be directly and secondarily mediated by vasopressin and corticosteroids (Nielsen et al, , 2002.…”

Section: Discussionmentioning

confidence: 99%

Expression of aquaporins and vasopressin type 2 receptor in the stria vascularis of the cochlea

et al. 2010

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“…Aquaporins (AQPs), a family of transmembrane water channel proteins, had originally been considered to play a key role in water homeostasis by regulating cellular water transport [2,3] . However, as reported to be involved in the transmembrane signaling by transporting signal molecules or coupling with other molecules as membrane proteins [4] , AQPs were suggested as targets for novel antitumor therapy based on their potential activity in carcinogenesis, tumor progression, and invasion [5][6][7][8][9][10] .…”

Section: Introductionmentioning

confidence: 99%

AQP5 Variants Affect Tumoral Expression of AQP5 and Survival in Patients with Early Breast Cancer

Lee

Kang²,

Kim³

et al. 2016

Oncology

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Background: Our previous study showed the association of AQP5 upregulation with cancer proliferation and migration in breast cancer cell lines and with unfavorable prognosis in patients with early breast cancer (EBC). In the current study, we analyzed the association of AQP5 variants or their haplotypes with AQP5 expression and their prognostic impact for survival in patients with EBC. Methods: Three AQP5 polymorphisms (rs74091166, rs3736309, and rs1964676) were selected based on the SNP database and genotyped using the Sequenom MassARRAY in 374 out of 447 patients with EBC in whom AQP5 expression had been investigated in our previous study. Results: The allele frequencies of the selected variants in the current study were similar to those from Asian data previously reported. In a univariate analysis, both rs74091166 and rs1964676 were statistically associated with survival as a dominant model of minor allele. Moreover, a multivariate survival analysis revealed that the CC genotype of rs1964676 is an independent prognostic marker of survival in EBC patients, regardless of stage, tumor subtype, and adjuvant treatment [hazard ratio = 0.399, 0.384, and 0.205; p = 0.021, 0.027, and 0.016 for disease-free survival (DFS), distant DFS, and disease-specific survival, respectively]. In particular, the CT/TT genotype of rs1964676 showed an association with strong expression of AQP5 (58.6 vs. 26.0%; p = 0.001), without any associations with clinical or pathological characteristics including tumor subtype, stage, or histologic grade. Conclusion: The current study suggests AQP5 rs1964676 as a new potential prognostic marker in patients with EBC involved in AQP5 expression.

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Biophysical properties of epithelial water channels

Cited by 20 publications

References 59 publications

Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports

Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports

Expression of aquaporins and vasopressin type 2 receptor in the stria vascularis of the cochlea

AQP5 Variants Affect Tumoral Expression of AQP5 and Survival in Patients with Early Breast Cancer

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