Isozyme-nonselective N-Substituted Bipiperidylcarboxamide Acetyl-CoA Carboxylase Inhibitors Reduce Tissue Malonyl-CoA Concentrations, Inhibit Fatty Acid Synthesis, and Increase Fatty Acid Oxidation in Cultured Cells and in Experimental Animals

Abstract

Inhibition of acetyl-CoA carboxylase (ACC), with its resultant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation, has the potential to favorably affect the multitude of cardiovascular risk factors associated with the metabolic syndrome. To achieve maximal effectiveness, an ACC inhibitor should inhibit both the lipogenic tissue isozyme (ACC1) and the oxidative tissue isozyme (ACC2). Herein, we describe the biochemical and acute physiological properties of CP-610431, an isozyme-nonselective ACC inhibitor identified through high throughput inhibition screening, and CP-640186, an analog with improved metabolic stability. CP-610431 inhibited ACC1 and ACC2 with IC 50 s of ϳ50 nM. Inhibition was reversible, uncompetitive with respect to ATP, and non-competitive with respect to bicarbonate, acetyl-CoA, and citrate, indicating interaction with the enzymatic carboxyl transfer reaction. CP-610431 also inhibited fatty acid synthesis, triglyceride (TG) synthesis, TG secretion, and apolipoprotein B secretion in HepG2 cells (ACC1) with EC 50 s of 1.6, 1.8, 3.0, and 5.7 M, without affecting either cholesterol synthesis or apolipoprotein CIII secretion. CP-640186, also inhibited both isozymes with IC 50 s of ϳ55 nM but was 2-3 times more potent than CP-610431 in inhibiting HepG2 cell fatty acid and TG synthesis. CP-640186 also stimulated fatty acid oxidation in C2C12 cells (ACC2) and in rat epitrochlearis muscle strips with EC 50 s of 57 nM and 1.3 M. In rats, CP-640186 lowered hepatic, soleus muscle, quadriceps muscle, and cardiac muscle malonyl-CoA with ED 50 s of 55, 6, 15, and 8 mg/kg. Consequently, CP-640186 inhibited fatty acid synthesis in rats, CD1 mice, and ob/ob mice with ED 50 s of 13, 11, and 4 mg/kg, and stimulated rat whole body fatty acid oxidation with an ED 50 of ϳ30 mg/kg. Taken together, These observations indicate that isozyme-nonselective ACC inhibition has the potential to favorably affect risk factors associated with the metabolic syndrome.

The role of rapid lipogenesis in insulin secretion: Insulin secretagogues acutely alter lipid composition of INS-1 832/13 cells

“…CP-640186, an inhibitor of acetyl-CoA carboxylase [21], partially inhibited insulin release from pancreatic islets and INS-1 832/13 cells (Figures 4 and 5). Triclosan is a potent inhibitor of the enoyl-acyl carrier protein reductase enzyme of the prokaryotic type II fatty acid synthase complex.…”

“…TOFA (5-(tetradecyloxy)-2-furoic acid) was from Alexis Biochemicals. CP-640186 was from H. James Harwood at Pfizer [21]. Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) was from Fluka BioChemika.…”

“…Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) was from Fluka BioChemika. Anti-actin (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33) antibody (catalog number A5060) and other chemicals were from Sigma. INS-1 832/13 cells were from Chris Newgard [22].…”

OPINIONS Acetyl-coenzyme A carboxylase – an attractive enzyme for biotechnology

“…One of the proposed medical applications of the enzymes depends on their inhibition, which is associated with inhibition of fatty acids synthesis and stimulation of fatty acids oxidation, and which, in consequence, might reduce cardiovascular risk in metabolic syndrome. Compound CP-610431 bipiperidine derivative, and its analog of higher metabolic stability CP-640186, isolated by high-throughput screening, are such inhibitors active against both ACCase isoforms (Harwood, Jr., et al 2003). Kinetic studies on ACCase -CP-610431 complex and the crystal structure of yeast CT domain -CP-640186 complex have revealed that the binding site for these inhibitors is located on the carboxyl transferase domain (Zhang et al, 2004).…”

Targeting energy expenditure via fuel switching and beyond

“…Second, the first Acc2 KO animals did not show a switching of fuels (i.e. change in respiratory exchange ratio [RER]), but rather an increase in Á V O 2 , which was not predicted by bioenergetics or evident with a dual Acc1 and Acc2 inhibitor in rats [12]. Recently, the Acc2 KO model was independently generated and resulted in an opposite phenotype [13].…”