Metabolomics Analysis Reveals that AICAR Affects Glycerolipid, Ceramide and Nucleotide Synthesis Pathways in INS-1 Cells.

Fri, 2016-06-24 11:54 -- voskuhlt
TitleMetabolomics Analysis Reveals that AICAR Affects Glycerolipid, Ceramide and Nucleotide Synthesis Pathways in INS-1 Cells.
Publication TypeJournal Article
Year of Publication2015
AuthorsElAzzouny MA, Evans CR, Burant CF, Kennedy RT
JournalPLoS One
Volume10
Issue6
Paginatione0129029
Date Published2015
ISSN1932-6203
KeywordsAcyl Coenzyme A, Aminoimidazole Carboxamide, AMP-Activated Protein Kinases, Animals, Carbon Isotopes, Cell Line, Ceramides, Diglycerides, Enzyme Activation, Gene Expression Regulation, Glucose, Hypoglycemic Agents, Insulin, Insulin-Secreting Cells, Malonyl Coenzyme A, Metabolic Networks and Pathways, Metabolomics, Polyisoprenyl Phosphates, Rats, Ribonucleotides, Sesquiterpenes, Signal Transduction
Abstract

AMPK regulates many metabolic pathways including fatty acid and glucose metabolism, both of which are closely associated with insulin secretion in pancreatic β-cells. Insulin secretion is regulated by metabolic coupling factors such as ATP/ADP ratio and other metabolites generated by the metabolism of nutrients such as glucose, fatty acid and amino acids. However, the connection between AMPK activation and insulin secretion in β-cells has not yet been fully elucidated at a metabolic level. To study the effect of AMPK activation on glucose stimulated insulin secretion, we applied the pharmacological activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) to an INS-1 (832/13) β-cell line. We measured the change in 66 metabolites in the presence or absence of AICAR using different stable isotopic labeled nutrients to probe selected pathways. AMPK activation by AICAR increased basal insulin secretion and reduced the glucose stimulation index. Although ATP/ADP ratios were not strongly affected by AICAR, several other metabolites and pathways important for insulin secretion were affected by AICAR treatment including long-chain CoAs, malonyl-CoA, 3-hydroxy-3 methylglutaryl CoA, diacylglycerol, and farnesyl pyrophosphate. Tracer studies using 13C-glucose revealed lower glucose flux in the purine and pyrimidine pathway and in the glycerolipid synthesis pathway. Untargeted metabolomics revealed reduction in ceramides caused by AICAR that may explain the beneficial role of AMPK in protecting β-cells from lipotoxicity. Taken together, the results provide an overall picture of the metabolic changes associated with AICAR treatment and how it modulates insulin secretion and β-cell survival.

DOI10.1371/journal.pone.0129029
Alternate JournalPLoS ONE
PubMed ID26107620
PubMed Central IDPMC4480354
Grant ListDK046960 / DK / NIDDK NIH HHS / United States
DK079084 / DK / NIDDK NIH HHS / United States
K25DK092558 / DK / NIDDK NIH HHS / United States
P30 DK089503 / DK / NIDDK NIH HHS / United States
P60 DK20572 / DK / NIDDK NIH HHS / United States