Use of cells expressing gamma subunit variants to identify diverse mechanisms of AMPK activation.
Cell Metab
; 11(6): 554-65, 2010 Jun 09.
Article
in En
| MEDLINE
| ID: mdl-20519126
ABSTRACT
A wide variety of agents activate AMPK, but in many cases the mechanisms remain unclear. We generated isogenic cell lines stably expressing AMPK complexes containing AMP-sensitive (wild-type, WT) or AMP-insensitive (R531G) gamma2 variants. Mitochondrial poisons such as oligomycin and dinitrophenol only activated AMPK in WT cells, as did AICAR, 2-deoxyglucose, hydrogen peroxide, metformin, phenformin, galegine, troglitazone, phenobarbital, resveratrol, and berberine. Excluding AICAR, all of these also inhibited cellular energy metabolism, shown by increases in ADPATP ratio and/or by decreases in cellular oxygen uptake measured using an extracellular flux analyzer. By contrast, A769662, the Ca(2+) ionophore, A23187, osmotic stress, and quercetin activated both variants to varying extents. A23187 and osmotic stress also increased cytoplasmic Ca(2+), and their effects were inhibited by STO609, a CaMKK inhibitor. Our approaches distinguish at least six different mechanisms for AMPK activation and confirm that the widely used antidiabetic drug metformin activates AMPK by inhibiting mitochondrial respiration.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
AMP-Activated Protein Kinases
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Cell Metab
Journal subject:
METABOLISMO
Year:
2010
Document type:
Article
Affiliation country: