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Mechano-sensitivity of ENaC: may the (shear) force be with you

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Abstract

The epithelial Na+ channel (ENaC) is the rate-limiting step for Na+ absorption in various vertebrate epithelia and deeply enmeshed in the control of salt and water homeostasis. The phylogenetic relationship of ENaC molecules to mechano-sensitive Degenerins from Caenorhabditis elegans indicates that ENaC might be mechano-sensitive as well. Primarily, it was suggested that ENaC might be activated by membrane stretch. However, this issue still remains to be clarified because controversial results were published. Recent publications indicate that shear stress represents an adequate stimulus, activating ENaC via increasing the single-channel open probability. Basing on the experimental evidence published within the past years and integrating this knowledge into a model related to the mechano-sensitive receptor complex known from C. elegans, we introduce a putative mechanism concerning the mechano-sensitivity of ENaC. We suggest that mechano-sensitive ENaC activation represents a nonhormonal regulatory mechanism. This feature could be of considerable physiological significance because many Na+-absorbing epithelia are exposed to shear forces. Furthermore, it may explain the wide distribution of ENaC proteins in nonepithelial tissues. Nevertheless, it remains a challenge for future studies to explore the mechanism how ENaC is controlled by mechanical forces and shear stress in particular.

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References

  1. Achard JM, Bubien JK, Benos DJ, Warnock DG (1996) Stretch modulates amiloride sensitivity and cation selectivity of sodium channels in human B lymphocytes. Am J Physiol 270:C224–C234

    PubMed  CAS  Google Scholar 

  2. Adams DJ, Barakeh J, Laskey R, Van Breemen C (1989) Ion channels and regulation of intracellular calcium in vascular endothelial cells. FASEB J 3:2389–2400

    PubMed  CAS  Google Scholar 

  3. Althaus M, Bogdan R, Clauss WG, Fronius M (2007) Mechano-sensitivity of epithelial sodium channels (ENaCs): laminar shear stress increases ion channel open probability. FASEB J 21:2389–2399

    Google Scholar 

  4. Amin MS, Wang HW, Reza E, Whitman SC, Tuana BS, Leenen FH (2005) Distribution of epithelial sodium channels and mineralocorticoid receptors in cardiovascular regulatory centers in rat brain. Am J Physiol Regul Integr Comp Physiol 289:R1787–R1797

    PubMed  CAS  Google Scholar 

  5. Anantharam A, Palmer LG (2007) Determination of epithelial Na+ channel subunit stoichiometry from single-channel conductances. J Gen Physiol 130(1):55–70

    Google Scholar 

  6. Awayda MS, Ismailov II, Berdiev BK, Benos DJ (1995) A cloned renal epithelial Na+ channel protein displays stretch activation in planar lipid bilayers. Am J Physiol 268:C1450–C1459

    PubMed  CAS  Google Scholar 

  7. Awayda MS, Subramanyam M (1998) Regulation of the epithelial Na+ channel by membrane tension. J Gen Physiol 112:97–111

    Article  PubMed  CAS  Google Scholar 

  8. Benos DJ, Awayda MS, Berdiev BK, Bradford AL, Fuller CM, Senyk O, Ismailov II (1996) Diversity and regulation of amiloride-sensitive Na+ channels. Kidney Int 49:1632–1637

    Article  PubMed  CAS  Google Scholar 

  9. Benos DJ, Stanton BA (1999) Functional domains within the degenerin/epithelial sodium channel (Deg/ENaC) superfamily of ion channels. J Physiol 520(Pt 3):631–644

    Article  PubMed  CAS  Google Scholar 

  10. Bounoutas A, Chalfie M (2007) Touch sensitivity in Caenorhabditis elegans. Pflugers Arch 454(5):691–702

    Google Scholar 

  11. Canessa CM, Horisberger JD, Rossier BC (1993) Epithelial sodium channel related to proteins involved in neurodegeneration. Nature 361:467–470

    Article  PubMed  CAS  Google Scholar 

  12. Canessa CM, Schild L, Buell G, Thorens B, Gautschi I, Horisberger JD, Rossier BC (1994) Amiloride-sensitive epithelial Na+ channel is made of three homologous subunits. Nature 367:463–467

    Article  PubMed  CAS  Google Scholar 

  13. Carattino MD, Sheng S, Kleyman TR (2004) Epithelial Na+ channels are activated by laminar shear stress. J Biol Chem 279:4120–4126

    Article  PubMed  CAS  Google Scholar 

  14. Carattino MD, Sheng S, Kleyman TR (2005) Mutations in the pore region modify epithelial sodium channel gating by shear stress. J Biol Chem 280:4393–4401

    Article  PubMed  CAS  Google Scholar 

  15. Chalfie M, Au M (1989) Genetic control of differentiation of the Caenorhabditis elegans touch receptor neurons. Science 243:1027–1033

    Article  PubMed  CAS  Google Scholar 

  16. Chrabi A, Horisberger JD (1999) Stimulation of epithelial sodium channel activity by the sulfonylurea glibenclamide. J Pharmacol Exp Ther 290:341–347

    PubMed  CAS  Google Scholar 

  17. Darboux I, Lingueglia E, Champigny G, Coscoy S, Barbry P, Lazdunski M (1998) dGNaC1, a gonad-specific amiloride-sensitive Na+ channel. J Biol Chem 273:9424–9429

    Article  PubMed  CAS  Google Scholar 

  18. Davies PF (1995) Flow-mediated endothelial mechanotransduction. Physiol Rev 75:519–560

    PubMed  CAS  Google Scholar 

  19. Driscoll M, Chalfie M (1991) The mec-4 gene is a member of a family of Caenorhabditis elegans genes that can mutate to induce neuronal degeneration. Nature 349:588–593

    Article  PubMed  CAS  Google Scholar 

  20. Drummond HA, Abboud FM, Welsh MJ (2000) Localization of beta and gamma subunits of ENaC in sensory nerve endings in the rat foot pad. Brain Res 884:1–12

    Article  PubMed  CAS  Google Scholar 

  21. Drummond HA, Gebremedhin D, Harder DR (2004) Degenerin/epithelial Na+ channel proteins: components of a vascular mechanosensor. Hypertension 44:643–648

    Article  PubMed  CAS  Google Scholar 

  22. Drummond HA, Price MP, Welsh MJ, Abboud FM (1998) A molecular component of the arterial baroreceptor mechanotransducer. Neuron 21:1435–1441

    Article  PubMed  CAS  Google Scholar 

  23. Drummond HA, Welsh MJ, Abboud FM (2001) ENaC subunits are molecular components of the arterial baroreceptor complex. Ann N Y Acad Sci 940:42–47

    Article  PubMed  CAS  Google Scholar 

  24. du Bois-Reymond E (1848) Untersuchungen über Tierische Elektrizität, vol. 1. G. Reimer, Berlin

    Google Scholar 

  25. Dyka FM, May CA, Enz R (2005) Subunits of the epithelial sodium channel family are differentially expressed in the retina of mice with ocular hypertension. J Neurochem 94:120–128

    Article  PubMed  CAS  Google Scholar 

  26. Emtage L, Gu G, Hartwieg E, Chalfie M (2004) Extracellular proteins organize the mechanosensory channel complex in C. elegans touch receptor neurons. Neuron 44:795–807

    Article  PubMed  CAS  Google Scholar 

  27. Eskandari S, Snyder PM, Kreman M, Zampighi GA, Welsh MJ, Wright EM (1999) Number of subunits comprising the epithelial sodium channel. J Biol Chem 274:27281–27286

    Article  PubMed  CAS  Google Scholar 

  28. Firsov D, Gautschi I, Merillat AM, Rossier BC, Schild L (1998) The heterotetrameric architecture of the epithelial sodium channel (ENaC). EMBO J 17:344–352

    Article  PubMed  CAS  Google Scholar 

  29. Fronius M, Clauss W, Schnizler M (2003) Stimulation of transepithelial Na(+) current by extracellular Gd(3+) in Xenopus laevis alveolar epithelium. J Membr Biol 195:43–51

    Article  PubMed  CAS  Google Scholar 

  30. Garty H, Palmer LG (1997) Epithelial sodium channels: function, structure, and regulation. Physiol Rev 77:359–396

    PubMed  CAS  Google Scholar 

  31. Giebisch G (1998) Renal potassium transport: mechanisms and regulation. Am J Physiol 274:F817–F833

    PubMed  CAS  Google Scholar 

  32. Giraldez T, Afonso-Oramas D, Cruz-Muros I, Garcia-Marin V, Pagel P, Gonzalez-Hernandez T, de la Rosa DA (2007) Cloning and functional expression of a new epithelial sodium channel delta subunit isoform differentially expressed in neurons of the human and monkey telencephalon. J Neurochem 102(4):1304–1315

    Article  PubMed  CAS  Google Scholar 

  33. Hamill OP, Martinac B (2001) Molecular basis of mechanotransduction in living cells. Physiol Rev 81:685–740

    PubMed  CAS  Google Scholar 

  34. Hamill OP, McBride DWJ (1997) Induced membrane hypo/hyper-mechanosensitivity: a limitation of patch-clamp recording. Annu Rev Physiol 59:621–631

    Article  PubMed  CAS  Google Scholar 

  35. Hummler E, Barker P, Gatzy J, Beermann F, Verdumo C, Schmidt A, Boucher R, Rossier BC (1996) Early death due to defective neonatal lung liquid clearance in alpha-ENaC-deficient mice. Nat Genet 12:325–328

    Article  PubMed  CAS  Google Scholar 

  36. Ishibashi K, Marumo F (1998) Molecular cloning of a DEG/ENaC sodium channel cDNA from human testis. Biochem Biophys Res Commun 245:589–593

    Article  PubMed  CAS  Google Scholar 

  37. Ismailov II, Berdiev BK, Shlyonsky VG, Benos DJ (1997) Mechanosensitivity of an epithelial Na+ channel in planar lipid bilayers: release from Ca2+ block. Biophys J 72:1182–1192

    PubMed  CAS  Google Scholar 

  38. Jernigan NL, Drummond HA (2006) Myogenic vasoconstriction in mouse renal interlobar arteries: role of endogenous beta and gammaENaC. Am J Physiol Renal Physiol 291:F1184–F1191

    Article  PubMed  CAS  Google Scholar 

  39. Ji HL, Fuller CM, Benos DJ (1998) Osmotic pressure regulates alpha beta gamma-rENaC expressed in Xenopus oocytes. Am J Physiol 275:C1182–C1190

    PubMed  CAS  Google Scholar 

  40. Ji HL, Su XF, Kedar S, Li J, Barbry P, Smith PR, Matalon S, Benos DJ (2006) Delta-subunit confers novel biophysical features to alpha beta gamma-human epithelial sodium channel (ENaC) via a physical interaction. J Biol Chem 281:8233–8241

    Article  PubMed  CAS  Google Scholar 

  41. Kellenberger S, Schild L (2002) Epithelial sodium channel/degenerin family of ion channels: a variety of functions for a shared structure. Physiol Rev 82:735–767

    PubMed  CAS  Google Scholar 

  42. Kizer N, Guo XL, Hruska K (1997) Reconstitution of stretch-activated cation channels by expression of the alpha-subunit of the epithelial sodium channel cloned from osteoblasts. Proc Natl Acad Sci U S A 94:1013–1018

    Article  PubMed  CAS  Google Scholar 

  43. Koefoed-Johnsen V, Ussing HH (1958) The nature of the frog skin potential. Acta Physiol Scand 42:298–308

    Article  PubMed  CAS  Google Scholar 

  44. Kung C (2005) A possible unifying principle for mechanosensation. Nature 436:647–654

    Article  PubMed  CAS  Google Scholar 

  45. Lingueglia E, Voilley N, Waldmann R, Lazdunski M, Barbry P (1993) Expression cloning of an epithelial amiloride-sensitive Na+ channel. A new channel type with homologies to Caenorhabditis elegans degenerins. FEBS Lett 318:95–99

    Article  PubMed  CAS  Google Scholar 

  46. Ma HP, Li L, Zhou ZH, Eaton DC, Warnock DG (2002) ATP masks stretch activation of epithelial sodium channels in A6 distal nephron cells. Am J Physiol Renal Physiol 282:F501–F505

    PubMed  CAS  Google Scholar 

  47. Mall M, Grubb BR, Harkema JR, O’Neal WK, Boucher RC (2004) Increased airway epithelial Na+ absorption produces cystic fibrosis-like lung disease in mice. Nat Med 10:487–493

    Article  PubMed  CAS  Google Scholar 

  48. Martinac B (2004) Mechanosensitive ion channels: molecules of mechanotransduction. J Cell Sci 117:2449–2460

    Article  PubMed  CAS  Google Scholar 

  49. Matthay MA, Folkesson HG, Clerici C (2002) Lung epithelial fluid transport and the resolution of pulmonary edema. Physiol Rev 82:569–600

    PubMed  CAS  Google Scholar 

  50. Mazzochi C, Bubien JK, Smith PR, Benos DJ (2006) The carboxyl terminus of the alpha-subunit of the amiloride-sensitive epithelial sodium channel binds to F-actin. J Biol Chem 281:6528–6538

    Article  PubMed  CAS  Google Scholar 

  51. Morimoto T, Liu W, Woda C, Carattino MD, Wei Y, Hughey RP, Apodaca G, Satlin LM, Kleyman TR (2006) Mechanism underlying flow stimulation of sodium absorption in the mammalian collecting duct. Am J Physiol Renal Physiol 291:F663–F669

    Article  PubMed  CAS  Google Scholar 

  52. O’Hagan R, Chalfie M, Goodman MB (2005) The MEC-4 DEG/ENaC channel of Caenorhabditis elegans touch receptor neurons transduces mechanical signals. Nat Neurosci 8:43–50

    Article  PubMed  CAS  Google Scholar 

  53. Olesen SP, Clapham DE, Davies PF (1988) Haemodynamic shear stress activates a K+ current in vascular endothelial cells. Nature 331:168–170

    Article  PubMed  CAS  Google Scholar 

  54. Palmer LG, Frindt G (1986) Amiloride-sensitive Na channels from the apical membrane of the rat cortical collecting tubule. Proc Natl Acad Sci U S A 83:2767–2770

    Article  PubMed  CAS  Google Scholar 

  55. Palmer LG, Frindt G (1996) Gating of Na channels in the rat cortical collecting tubule: effects of voltage and membrane stretch. J Gen Physiol 107:35–45

    Article  PubMed  CAS  Google Scholar 

  56. Palmer LG, Sackin H, Frindt G (1998) Regulation of Na+ channels by luminal Na+ in rat cortical collecting tubule. J Physiol 509:151–162

    Article  PubMed  CAS  Google Scholar 

  57. Puoti A, May A, Canessa CM, Horisberger JD, Schild L, Rossier BC (1995) The highly selective low-conductance epithelial Na channel of Xenopus laevis A6 kidney cells. Am J Physiol 269:C188–C197

    PubMed  CAS  Google Scholar 

  58. Rossier BC (1998) Mechanosensitivity of the epithelial sodium channel (ENaC): controversy or pseudocontroversy. J Gen Physiol 112:95–96

    Article  PubMed  CAS  Google Scholar 

  59. Rossier BC (2002) Hormonal regulation of the epithelial sodium channel ENaC: N or P(o). J Gen Physiol 120:67–70

    Article  PubMed  CAS  Google Scholar 

  60. Rossier BC (2004) The epithelial sodium channel: activation by membrane-bound serine proteases. Proc Am Thorac Soc 1:4–9

    Article  PubMed  CAS  Google Scholar 

  61. Rossier BC, Pradervand S, Schild L, Hummler E (2002) Epithelial sodium channel and the control of sodium balance: interaction between genetic and environmental factors. Annu Rev Physiol 64:877–897

    Article  PubMed  CAS  Google Scholar 

  62. Satlin LM, Carattino MD, Liu W, Kleyman TR (2006) Regulation of cation transport in the distal nephron by mechanical forces. Am J Physiol Renal Physiol 291:F923–F931

    Article  PubMed  CAS  Google Scholar 

  63. Satlin LM, Sheng S, Woda CB, Kleyman TR (2001) Epithelial Na(+) channels are regulated by flow. Am J Physiol Renal Physiol 280:F1010–F1018

    PubMed  CAS  Google Scholar 

  64. Schnizler M, Berk A, Clauss W (2003) Sensitivity of oocyte-expressed epithelial Na+ channel to glibenclamide. Biochim Biophys Acta 1609:170–176

    Article  PubMed  CAS  Google Scholar 

  65. Sheng S, Perry CJ, Kleyman TR (2004) Extracellular Zn2+ activates epithelial Na+ channels by eliminating Na+ self-inhibition. J Biol Chem 279:31687–31696

    Article  PubMed  CAS  Google Scholar 

  66. Smith PR, Saccomani G, Joe EH, Angelides KJ, Benos DJ (1991) Amiloride-sensitive sodium channel is linked to the cytoskeleton in renal epithelial cells. Proc Natl Acad Sci U S A 88:6971–6975

    Article  PubMed  CAS  Google Scholar 

  67. Snyder PM, Cheng C, Prince LS, Rogers JC, Welsh MJ (1998) Electrophysiological and biochemical evidence that DEG/ENaC cation channels are composed of nine subunits. J Biol Chem 273:681–684

    Article  PubMed  CAS  Google Scholar 

  68. Snyder PM, Price MP, McDonald FJ, Adams CM, Volk KA, Zeiher BG, Stokes JB, Welsh MJ (1995) Mechanism by which Liddle’s syndrome mutations increase activity of a human epithelial Na+ channel. Cell 83:969–978

    Article  PubMed  CAS  Google Scholar 

  69. Tarran R, Button B, Boucher RC (2006) Regulation of normal and cystic fibrosis airway surface liquid volume by phasic shear stress. Annu Rev Physiol 68:543–561

    Article  PubMed  CAS  Google Scholar 

  70. Tarran R, Button B, Picher M, Paradiso AM, Ribeiro CM, Lazarowski ER, Zhang L, Collins PL, Pickles RJ, Fredberg JJ, Boucher RC (2005) Normal and cystic fibrosis airway surface liquid homeostasis. The effects of phasic shear stress and viral infections. J Biol Chem 280:35751–35759

    Article  PubMed  CAS  Google Scholar 

  71. Tavernarakis N, Driscoll M (2000) Caenorhabditis elegans degenerins and vertebrate ENaC ion channels contain an extracellular domain related to venom neurotoxins. J Neurogenet 13:257–264

    PubMed  CAS  Google Scholar 

  72. Tavernarakis N, Driscoll M (2001) Degenerins. At the core of the metazoan mechanotransducer? Ann N Y Acad Sci 940:28–41

    Article  PubMed  CAS  Google Scholar 

  73. Trujillo E, Alvarez de la Rosa D, Mobasheri A, Gonzalez T, Canessa CM, Martin-Vasallo P (1999) Sodium transport systems in human chondrocytes. II. Expression of ENaC, Na+/K+/2Cl cotransporter and Na+/H+ exchangers in healthy and arthritic chondrocytes. Histol Histopathol 14:1023–1031

    PubMed  CAS  Google Scholar 

  74. Turnheim K (1991) Intrinsic regulation of apical sodium entry in epithelia. Physiol Rev 71:429–445

    PubMed  CAS  Google Scholar 

  75. Ussing HH (1960) The frog skin potential. J Gen Physiol 43:135–147

    Article  PubMed  CAS  Google Scholar 

  76. Waldmann R, Champigny G, Bassilana F, Voilley N, Lazdunski M (1995) Molecular cloning and functional expression of a novel amiloride-sensitive Na+ channel. J Biol Chem 270:27411–27414

    Article  PubMed  CAS  Google Scholar 

  77. Wan X, Juranka P, Morris CE (1999) Activation of mechanosensitive currents in traumatized membrane. Am J Physiol 276:C318–C327

    PubMed  CAS  Google Scholar 

  78. Wang EC, Lee JM, Johnson JP, Kleyman TR, Bridges R, Apodaca G (2003) Hydrostatic pressure-regulated ion transport in bladder uroepithelium. Am J Physiol Renal Physiol 285:F651–F663

    PubMed  CAS  Google Scholar 

  79. Weinbaum S, Zhang X, Han Y, Vink H, Cowin SC (2003) Mechanotransduction and flow across the endothelial glycocalyx. Proc Natl Acad Sci U S A 100:7988–7995

    Article  PubMed  CAS  Google Scholar 

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Acknowledgments

The authors want to thank M. Althaus, R. Bogdan, and J. Strauss for helpful comments and discussions to improve the manuscript. This work is supported by DFG (Deutsche Forschungsgemeinschaft).

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Fronius, M., Clauss, W.G. Mechano-sensitivity of ENaC: may the (shear) force be with you. Pflugers Arch - Eur J Physiol 455, 775–785 (2008). https://doi.org/10.1007/s00424-007-0332-1

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