K+-dependent cerebellar granule neuron apoptosis. Role of task leak K+ channels.
Rat mature cerebellar granule, unlike hippocampal neurons, die by apoptosis when cultured in a medium containing a physiological concentration of K+ but survive under high external K+ concentrations. Cell death in physiological K+ parallels the developmental expression of the TASK-1 and TASK-3 subunits that encode the pH-sensitive standing outward K+ current IKso. Genetic transfer of the TASK subunits in hippocampal neurons, lacking IKso, induces cell death, while their genetic inactivation protects cerebellar granule neurons. Neuronal death of cultured rat granule neurons is also prevented by conditions that specifically reduce K+ efflux through the TASK-3 channels such as extracellular acidosis and ruthenium red. TASK leak K+ channels thus play an important role in K+-dependent apoptosis of cerebellar granule neurons in culture.
Lauritzen
Inger
I
Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Institut Paul Hamel, 660 route des Lucioles, Sophia Antipolis, 06560 Valbonne, France.
Zanzouri
Marc
M
Honoré
Eric
E
Duprat
Fabrice
F
Ehrengruber
Markus U
MU
Lazdunski
Michel
M
Patel
Amanda J
AJ
D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D002531:Cerebellum / Q000166:cytology* / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000378:metabolism*; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental; D006863:Hydrogen-Ion Concentration; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics / Q000502:physiology*; D024683:Potassium Channels, Tandem Pore Domain; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; C407082:Kcnk9 protein, rat; D009419:Nerve Tissue Proteins; D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; C420132:potassium channel subfamily K member 3; D011188:Potassium