Evidence for several mechanisms of volume regulation in neuroblastoma×glioma hybrid NG108-15 cells

Rouzaire‐Dubois, Béatrice; Bostel, Sébastien; Dubois, Jean‐Marc

doi:10.1016/s0306-4522(98)00236-x

Cited by 12 publications

(15 citation statements)

References 35 publications

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“…However, even after the inhibition of these volume regulations, several cell types behave as imperfect osmometers after anisotonic challenges of ≥50% at room or physiological temperatures [6,14]. Moreover, we showed that the volume of neuroblastoma cells was differentially modified by anisotonicity when the external Cl − concentration was constant or variable [29]. These observations suggest that cell volume and cell volume regulations are controlled by several mechanisms, some of which are only partly understood.…”

Section: Introductionmentioning

confidence: 90%

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Rouzaire‐Dubois¹,

Ouanounou²,

O’Regan³

et al. 2008

Pflugers Arch - Eur J Physiol

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Cell volume controls many functions and is itself regulated. To study cell volume regulations, the mean volume of C6-BU-1 rat glioma cells was electronically measured under isotonic and anisotonic conditions. Two isotonic solutions were used containing either normal (solution 1) or low (solution 2) NaCl. Anisotonicity was induced by changing NaCl or sucrose concentrations in solutions 1 and 2, respectively. The cells behaved like perfect osmometers when the tonicity was increased. In contrast, just after hypotonic challenges, the cell volume was smaller than that predicted by a perfect osmometer. This deviation reveals a new mechanism, which we call the volume increase limitation (VIL). When hypotonicity was induced by decreasing NaCl, a classical slow regulatory volume decrease (RVD) was also observed in addition to VIL. The cells expressed aquaporin-1 sensitive to HgCl(2) and decreased by siRNA, which both reduced fast volume changes. In this study, we show that: (1) RVD is proportional to the change in external Cl(-) concentration and is inhibited by Cl(-) channel and K(+)-Cl(-) cotransporter blockers; (2) cell swelling due to the influx of H(2)O through aquaporins shows rectification with decreasing osmolarity and is sensitive to the internal Na(+) concentration; (3) VIL is linearly related with hypotonicity and is abolished in solutions 1 and 2 by the Na(+) ionophore monensin and in solution 1 by the Na(+)-K(+) ATPase inhibitor ouabain. These results suggest that VIL is triggered by the decrease in internal Na(+) caused by hyponatrema and cell swelling. In addition to RVD, VIL should protect cells during hyposmotic stress.

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Section: Introductionmentioning

confidence: 90%

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Rouzaire‐Dubois¹,

Ouanounou²,

O’Regan³

et al. 2008

Pflugers Arch - Eur J Physiol

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“…However in different cell types, deviations from this law have often been observed. We previously showed that the cell volume was not only dependent on the osmolarity but also on the NaCl concentration (Rouzaire-Dubois et al 1999Rouzaire-Dubois and Dubois 2010). In the present work, we studied the change in steady-state volume of rat glioma cells under three different conditions, namely: at different osmolarities and constant NaCl concentration; at different NaCl concentrations and constant osmolarity and at different osmolarities and NaCl concentrations.…”

Section: Discussionmentioning

confidence: 87%

“…Second, in hyposmotic solutions, the cell volume deviated from the perfect osmometer and saturated at low osmolarity (Arrazola et al 1993;Rouzaire-Dubois et al 2009). Third and independently of the osmolarity, the cell volume was dependent on the NaCl concentration (Rouzaire-Dubois et al 1999). During anisotonic challenges, deviations from the perfect osmometer can be explained by a regulatory volume decrease (RVD) or increase (RVI) due to ion and organic osmolyte fluxes mediated by the activation of channels and transporters and osmotically obliged water fluxes (Lang et al 1998).…”

Section: Introductionmentioning

confidence: 99%

“…Except in erythrocytes that behave as a perfect osmometer over a large range of osmolarity (Prickett et al 2008), deviations from the Boyle-van't Hoff law have often been observed in various cell types. First, depending on cell types and external ion composition, b/V 0 , which is obtained by extrapolation, varied between 0 and 0.8 (Arrazola et al 1993;Crowe et al 1995;Rouzaire-Dubois et al 1999. Second, in hyposmotic solutions, the cell volume deviated from the perfect osmometer and saturated at low osmolarity (Arrazola et al 1993;Rouzaire-Dubois et al 2009).…”

Section: Introductionmentioning

confidence: 99%

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Relationship between extracellular osmolarity, NaCl concentration and cell volume in rat glioma cells

Rouzaire‐Dubois¹,

Ouanounou²,

Dubois³

2011

gpb

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Abstract. The cell volume, which controls numerous cellular functions, is theoretically linearly related with the inverse osmolarity. However, deviations from this law have often been observed. In order to clarify the origin of these deviations we electronically measured the mean cell volume of rat glioma cells under three different experimental conditions, namely: at different osmolarities and constant NaCl concentration; at different NaCl concentrations and constant osmolarity and at different osmolarities caused by changes in NaCl concentration. In each condition, the osmolarity was maintained constant or changed with NaCl or mannitol. We showed that the cell volume was dependent on both the extracellular osmolarity and the NaCl concentration. The relationship between cell volume, osmolarity and NaCl concentration could be described by a new equation that is the product of the Boyle-van't Hoff law and the Michaelis-Menten equation at a power of 4. Together, these results suggest that in hyponatriemia, the cell volume deviates from the Boyle-van't Hoff law because either the activity of aquaporin 1, expressed in glioma cells, is decreased or the reduced NaCl influx decreases the osmotically obliged influx of water.

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“…These too found that the rate of cell proliferation correlates with the rate of cell volume change following a bell-shaped curve, with both very high and very low volumes decreasing the rate of proliferation [14]. Similarly, proliferation rates were sensitive to volume changes, where experimentally altering osmolarity to induce swelling decreased proliferation rates, and shrinking cells increased proliferation [16]. These studies clearly establish cell volume regulation as a critical component of the cell cycle and identify one mechanism whereby Cl 2 channels directly participate.…”

Section: Proliferationmentioning

confidence: 99%

Cl ⁻ and K ⁺ channels and their role in primary brain tumour biology

Turner

Sontheimer

2014

Phil. Trans. R. Soc. B

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Profound cell volume changes occur in primary brain tumours as they proliferate, invade surrounding tissue or undergo apoptosis. These volume changes are regulated by the flux of Cl − and K + ions and concomitant movement of water across the membrane, making ion channels pivotal to tumour biology. We discuss which specific Cl − and K + channels are involved in defined aspects of glioma biology and how these channels are regulated. Cl − is accumulated to unusually high concentrations in gliomas by the activity of the NKCC1 transporter and serves as an osmolyte and energetic driving force for volume changes. Cell volume condensation is required as cells enter M phase of the cell cycle and this pre-mitotic condensation is caused by channel-mediated ion efflux. Similarly, Cl − and K + channels dynamically regulate volume in invading glioma cells allowing them to adjust to small extracellular brain spaces. Finally, cell condensation is a hallmark of apoptosis and requires the concerted activation of Cl − and Ca 2+ -activated K + channels. Given the frequency of mutation and high importance of ion channels in tumour biology, the opportunity exists to target them for treatment.

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Evidence for several mechanisms of volume regulation in neuroblastoma×glioma hybrid NG108-15 cells

Cited by 12 publications

References 35 publications

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Relationship between extracellular osmolarity, NaCl concentration and cell volume in rat glioma cells

Cl ⁻ and K ⁺ channels and their role in primary brain tumour biology

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Evidence for several mechanisms of volume regulation in neuroblastoma×glioma hybrid NG108-15 cells

Cited by 12 publications

References 35 publications

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Sodium-dependent activity of aquaporin-1 in rat glioma cells: a new mechanism of cell volume regulation

Relationship between extracellular osmolarity, NaCl concentration and cell volume in rat glioma cells

Cl − and K + channels and their role in primary brain tumour biology

Contact Info

Product

Resources

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Cl ⁻ and K ⁺ channels and their role in primary brain tumour biology