Gene expression analysis in rats treated with experimental acetyl-coenzyme A carboxylase inhibitors suggests interactions with the peroxisome proliferator-activated receptor alpha pathway

J Pharmacol Exp Ther. 2008 Feb;324(2):507-16. doi: 10.1124/jpet.107.126938. Epub 2007 Nov 19.

Abstract

Acetyl CoA carboxylase (ACC) 2, which catalyzes the carboxylation of acetyl-CoA to form malonyl-CoA, has been identified as a potential target for type 2 diabetes and obesity. Small-molecule inhibitors of ACC2 would be expected to reduce de novo lipid synthesis and increase lipid oxidation. Treatment of ob/ob mice with compound A-908292 (S) ({(S)-3-[2-(4-isopropoxy-phenoxy)-thiazol-5-yl]-1-methyl-prop-2-ynyl}-carbamic acid methyl ester), a small-molecule inhibitor with an IC(50) of 23 nM against ACC2, resulted in a reduction of serum glucose and triglyceride levels. However, compound A-875400 (R) ({(R)-3-[2-(4-isopropoxy-phenoxy)-thiazol-5-yl]-1-methyl-prop-2-ynyl}-carbamic acid methyl ester), an inactive enantiomer of A-908292 (S) with approximately 50-fold less activity against ACC2, also caused a similar reduction in glucose and triglycerides, suggesting that the glucose-lowering effects in ob/ob mice may be mediated by other metabolic pathways independent of ACC2 inhibition. To characterize the pharmacological activity of these experimental compounds at a transcriptional level, rats were orally dosed for 3 days with either A-908292 (S) or A-875400 (R), and gene expression analysis was performed. Gene expression analysis of livers showed that treatment with A-908292 (S) or A-875400 (R) resulted in gene expression profiles highly similar to known peroxisome proliferator-activated receptor (PPAR)-alpha activators. The results suggest that, in vivo, both A-908292 (S) and A-875400 (R) stimulated the PPAR-alpha-dependent signaling pathway. These results were further supported by both an in vitro genomic evaluation using rat hepatocytes and immunohistochemical evaluation using 70-kDa peroxisomal membrane protein. Overall, the gene expression analysis suggests a plausible mechanism for the similar pharmacological findings with active and inactive enantiomers of an ACC2 inhibitor.

Publication types

  • Comparative Study

MeSH terms

  • Acetyl-CoA Carboxylase / antagonists & inhibitors*
  • Acetyl-CoA Carboxylase / metabolism
  • Animals
  • Enzyme Inhibitors / pharmacology
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology*
  • Hepatocytes
  • Humans
  • Mice
  • Mice, Obese
  • PPAR alpha / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*

Substances

  • Enzyme Inhibitors
  • PPAR alpha
  • Acetyl-CoA Carboxylase