Clozapine activates AMP-activated protein kinase (AMPK) in C2C12 myotube cells and stimulates glucose uptake.
OBJECTIVE
Clozapine has previously been implicated in the dysregulation of energy balance and glucose metabolism in the central nervous system, but its effects in the periphery have yet to be thoroughly elucidated. The objective of this study was to characterize the effects of clozapine on AMP-activated protein kinase (AMPK) activity in the skeletal muscles.


METHODS
Myotube C2C12 cells were incubated under control conditions, or with clozapine. Expression levels of phosphorylation status of AMPK and its direct downstream Acetyl-CoA carboxylase (ACC) were analyzed by Western blot. Intracellular calcium concentration was measured with calcium indicator dye, fluo-3AM. 2-deoxyglucose uptake was assessed via the scintillation count.


RESULTS
We reported that clozapine activated AMPK in mouse C2C12 myotubes and also stimulated glucose uptake. Clozapine also increased intracellular calcium concentrations of C2C12 cells, and pretreatment with either ethylenediaminetetraacetic acid (EDTA), an extracellular calcium chelator, or 1.8-naphthoylene benzimidazole-3-carboxylic acid (STO-609), a Ca(2+)/calmodulin-dependent protein kinase kinase (CaMKK) inhibitor, blocked clozapine-induced AMPK activation.


CONCLUSIONS
These results demonstrate that clozapine increases glucose uptake through CaMKK-AMPK pathway in myotube C2C12 cells.
Department of Anatomy, Korea University College of Medicine, Anamdong 5 ga, Seungbuk gu, Seoul, Republic of Korea.
Ji Hae
JH
Kim
Jung Ok
JO
Lee
Soo Kyung
SK
Lee
Jin Hee
JH
Jung
Ga Young
GY
You
Sun Hwa
SH
Park
Munho
M
Park
Sang Dae
SD
Kim
Hyeon Soo
HS
Kim
D055372:AMP-Activated Protein Kinases / Q000187:drug effects* / Q000378:metabolism; D000103:Acetyl-CoA Carboxylase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D003024:Clozapine / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D012588:Scintillation Counting
D014150:Antipsychotic Agents; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D055372:AMP-Activated Protein Kinases; D000103:Acetyl-CoA Carboxylase; D005947:Glucose; D003024:Clozapine; D002118:Calcium