NAD(P)H oxidase-derived H(2)O(2) signals chloride channel activation in cell volume regulation and cell proliferation.
Cellular swelling triggers the activation of Cl(-) channels (volume-sensitive outwardly rectifying (VSOR) Cl(-) channels) in many cell types. Ensuing regulatory volume decrease has been considered the primary function of these channels. However, Cl(-) channels, which share functional properties with volume-sensitive Cl(-) channels, have been shown to be involved in other physiological processes, including cell proliferation and apoptosis, raising the question of their physiological roles and the signal transduction pathways involved in their activation. Here we report that exogenously applied H(2)O(2) elicited VSOR Cl(-) channel activation. Furthermore, activation of these channels was found to be coupled to NAD(P)H oxidase activity. Also, epidermal growth factor, known to increase H(2)O(2) production, activated Cl(-) channels with properties identical to swelling-sensitive Cl(-) channels. It is concluded that NAD(P)H oxidase-derived H(2)O(2) is the common signal transducing molecule that mediates the activation of these ubiquitously expressed anion channels under a variety of physiological conditions.
Varela
Diego
D
Instituto de Ciencias Biomédicas and Centro de Estudios Moleculares de la Célula Facultad de Medicina Universidad de Chile, Santiago-6530499, Santiago, Chile.
Simon
Felipe
F
Riveros
Ana
A
Jørgensen
Finn
F
Stutzin
Andrés
A
D002455:Cell Division / Q000502:physiology; D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007038:Hypotonic Solutions / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D019255:NADPH Oxidases; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology; D014162:Transfection; D014882:Water-Electrolyte Balance / Q000502:physiology*
D018118:Chloride Channels; D002712:Chlorides; D007038:Hypotonic Solutions; D010750:Phosphoproteins; D004815:Epidermal Growth Factor; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1