Evidence for the involvement of K+ channels and K+-Cl– cotransport in the regulatory volume decrease of newborn rat cardiomyocytes

Taouil, Karima; Hannaert, Patrick

doi:10.1007/s004249900117

Cited by 15 publications

(10 citation statements)

References 26 publications

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“…The suppression of multiple membrane channels by suramin was partially verified by the observation that suramin potently blocked hypotonicity‐induced ATP release. Previous studies have demonstrated that hypotonic release of ATP was derived from multiple membrane channels, including K/ATP channel, KCNQ channel, Cx hemichannel, voltage‐dependent anion channel, ATP‐conductive large‐conductance anion channel, maxi‐anion channel and CFTR (Taouil and Hannaert, ; Hazama et al ., ; Braunstein et al ., ; Sabirov et al ., ; Boudreault and Grygorczyk, ; Dutta et al ., ; Okada et al ., ; Calloe et al ., ; Liu et al ., ; Shi et al ., ; Lu et al ., ). Using hemichannel inhibitors and Cx43 siRNA, we clearly demonstrated an involvement of hemichannels.…”

Section: Discussionmentioning

confidence: 99%

Suppression of cell membrane permeability by suramin: involvement of its inhibitory actions on connexin 43 hemichannels

Chi

Gao

Zhang

et al. 2014

British J Pharmacology

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BACKGROUND AND PURPOSESuramin is a clinically prescribed drug for treatment of human African trypanosomiasis, cancer and infection. It is also a well-known pharmacological antagonist of P2 purinoceptors. Despite its clinical use and use in research, the biological actions of this molecule are still incompletely understood. Here, we investigated the effects of suramin on membrane channels, as exemplified by its actions on non-junctional connexin43 (Cx43) hemichannels, pore-forming α-haemolysin and channels involved in ATP release under hypotonic conditions. EXPERIMENTAL APPROACHHemichannels were activated by removing extracellular Ca 2+. The influences of suramin on hemichannel activities were evaluated by its effects on influx of fluorescent dyes and efflux of ATP. The membrane permeability and integrity were assessed through cellular retention of preloaded calcein and LDH release. KEY RESULTSSuramin blocked Cx43 hemichannel permeability induced by removal of extracellular Ca 2+ without much effect on Cx43 expression and gap junctional intercellular communication. This action of suramin was mimicked by its analogue NF023 and NF449 but not by another P2 purinoceptor antagonist PPADS. Besides hemichannels, suramin also significantly blocked intracellular and extracellular exchanges of small molecules caused by α-haemolysin from Staphylococcus aureus and by exposure of cells to hypotonic solution. Furthermore, it prevented α-haemolysin-and hypotonic stress-elicited cell injury. CONCLUSION AND IMPLICATIONSSuramin blocked membrane channels and protected cells against toxin-and hypotonic stress-elicited injury. Our finding provides novel mechanistic insights into the pharmacological actions of suramin. Suramin might be therapeutically exploited to protect membrane integrity under certain pathological situations. AbbreviationsCx43, connexin 43; EtBr, ethidium bromide; GJIC, gap junctional intercellular communication; LY, Lucifer yellow; NRK, Normal rat kidney; PPADS, pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid

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Section: Discussionmentioning

confidence: 99%

Suppression of cell membrane permeability by suramin: involvement of its inhibitory actions on connexin 43 hemichannels

Chi

Gao

Zhang

et al. 2014

British J Pharmacology

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“…Reactions used 5 mM BS 3 for 60 min at 4°C (Pierce). After cross-linking, reactions were stopped by the addition of Tris, and when appropriate, Triton-soluble and -insoluble fractions were isolated as above.…”

Section: Isolation and Taurinementioning

confidence: 99%

“…Hypoosmotic induced tyrosine phosphorylation of skAE1 tetramers occurs in both detergent-resistant and -soluble material and is present in both buoyant and dense fractions of detergent-resistant membranes. Membranes were isolated from cells in isoosmotic and hypoosmotic conditions, and proteins were cross-linked using the homobifunctional cross-linker BS 3 (except the left blot of A, which is non-cross-linked skAE1). After these reactions, a portion of the material was solubilized with Triton X-100 to obtain soluble and detergentresistant fractions.…”

Section: Figmentioning

confidence: 99%

“…A large number of pathways exist in various cells to accomplish this regulatory volume decrease. Electrolytes, notably K ϩ and Cl Ϫ , may exit through KCl cotransport in a variety of cell types (1)(2)(3)(4)(5)(6). Many cells utilize the efflux of non-metabolized non-electrolytes such as betaine, sorbitol, and the ␤-amino acid taurine (for reviews, see Refs.…”

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confidence: 99%

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Hypotonicity-induced Exocytosis of the Skate Anion Exchanger skAE1

Musch

Koomoa

Goldstein

2004

Journal of Biological Chemistry

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Upon hypotonic volume expansion, skate erythrocytes lose solutes via a pathway that requires participation of anion exchangers (AEs). Three skate AE isoforms (skAEs) are expressed, and at least skAE1 has been shown to mediate this effect when expressed in oocytes. Under isoosmotic conditions, only a small fraction of skAE1 is expressed on the external plasma membrane. Under these conditions, a portion of skAE1 may be found in non-ionic detergent-insoluble regions. However, the detergent-insoluble material is found intracellularly. Cellular volume expansion by hypoosmotic volume expansion but not volume expansion by isoosmotic medium by permeant solutes (ethylene glycol, diethyl urea, or ammonium chloride) stimulates the appearance of skAE1 in the external plasma membrane, and a significant portion of this is found in detergent-insoluble regions. Upon hypoosmotic volume expansion nearly half of the skAE1 is found as oligomers. SkAE1 in these detergent-insoluble fractions is highly tyrosine phosphorylated. These data suggest that volume expansion by hypoosmotic medium stimulates movement of skAE1 from an intracellular pool contained in detergent-insoluble lipid rafts to the plasma membrane. This skAE1 associates to form oligomers that could be involved in the solute efflux that occurs upon volume expansion.

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“…This result could be due to inhibition of electroneutral KCl cotransport (KCCs) or Cl - channels involved in RVD [54; 55]. KCl cotransporters have been described in heart cells [56] and a role was suggested for KCl cotransport in cardiac myocyte RVD [57]. …”

Section: Discussionmentioning

confidence: 99%

Regulatory Volume Increase and Regulatory Volume Decrease Responses in HL-1 Atrial Myocytes

Cacace

Finkelsteyn

Tasso

et al. 2014

Cell Physiol Biochem

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Background/Aims: we have investigated whether cultured cardiomyocytes of the cell line HL-1 have the ability to perform regulatory volume responses both in hypotonic and hypertonic conditions. Furthermore, we characterized those regulatory responses and studied the effects of bumetanide and DIDS in volume regulation of HL-1 cells. Methods: we used a light scattering system to measure the transient volume changes of HL-1 cells when subjected to osmotic challenge. Results: We found that HL-1 cells correct for their volume excess by undergoing regulatory volume decrease (RVD), and also respond to hypertonic stress with a regulatory volume increase (RVI). Rate of RVD was 0.08 ± 0.04 intensity/min, and rate of RVI was 0.09 ± 0.01 intensity/min. Volume recovery was 83.68 ± 5.73 % for RVD and 92.3 ± 2.3 % for RVI. Bumetanide 50 µM inhibited volume recovery, from 92.3 ± 2.3 % (control) to 24.6 ± 8.8 % and reduced the rate of RVI from 0.070 ± 0.020 intensity/min (control) to 0.010 ± 0.005 intensity/min. 50 µM DIDS reduced volume recovery to 42.93 ± 7.7 % and rate of RVI, to 0.03 ± 0.01 intensity/min. Conclusions: these results suggest that bumetanide- and DIDS-sensitive mechanisms are involved in the RVI of HL-1 cells, which points to the involvement of the Na⁺/K⁺/2Cl^- cotransporter and Cl^-/bicarbonate exchanger in RVI, respectively.

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Evidence for the involvement of K+ channels and K+-Cl– cotransport in the regulatory volume decrease of newborn rat cardiomyocytes

Cited by 15 publications

References 26 publications

Suppression of cell membrane permeability by suramin: involvement of its inhibitory actions on connexin 43 hemichannels

Suppression of cell membrane permeability by suramin: involvement of its inhibitory actions on connexin 43 hemichannels

Hypotonicity-induced Exocytosis of the Skate Anion Exchanger skAE1

Regulatory Volume Increase and Regulatory Volume Decrease Responses in HL-1 Atrial Myocytes

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