Development of Novel Adenosine Monophosphate-Activated Protein Kinase Activators

Abstract

In light of the unique ability of thiazolidinediones to mediate peroxisome proliferator-activated receptor (PPAR)γ-independent activation of adenosine monophosphate-activated protein kinase (AMPK) and suppression of interleukin (IL)-6 production, we conducted a screening of an in-house, thiazolidinedione-based focused compound library to identify novel agents with these dual pharmacological activities. Cell-based assays pertinent to the activation status of AMPK and mammalian homolog of target of rapamycin (i.e., phosphorylation of AMPK and p70 ribosomal protein S6 kinase, respectively), and IL-6/IL-6 receptor signaling (i.e., IL-6 production and signal transducer and activator of transcription 3 phosphorylation, respectively) in lipopolysaccharide (LPS)-stimulated THP-1 human macrophages were used to screen this compound library, which led to the identification of compound 53 (N-{4-[3-(1-Methylcyclohexylmethyl)-2,4-dioxothiazolidin-5-ylidene-methyl]-phenyl}-4-nitro-3-trifluoromethyl-benzenesulfonamide) as the lead agent. Evidence indicates that this drug-induced suppression of LPS-stimulated IL-6 production was attributable to AMPK activation. Furthermore, compound 53-mediated AMPK activation was demonstrated in C-26 colon adenocarcinoma cells, indicating that it is not a cell line-specific event.

Targeting Energy Metabolic and Oncogenic Signaling Pathways in Triple-negative Breast Cancer by a Novel Adenosine Monophosphate-activated Protein Kinase (AMPK) Activator

“…Reagents and Antibodies-OSU-53 was synthesized according to a published procedure (18). For in vitro experiments, OSU-53 was dissolved in DMSO, diluted in culture medium, and added to cells at a final DMSO concentration of 0.1%.…”

“…Cell Viability and Colony Formation Assays-Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays as reported previously (18). Cells were seeded at 3 ϫ 10 3 cells/well 24 h prior to treatment.…”

“…After brief centrifugation, equivalent amounts of proteins from the soluble fractions of cell lysates were resolved by SDS-PAGE, transferred to nitrocellulose membranes, and immunoblotted as described previously (18).…”

“…Thus, there is an urgency to develop potent activators of this fuel-sensing enzyme with a distinct mode of action. Based on our finding that thiazolidinediones activated AMPK, in part, via a peroxisome proliferator-activated receptor (PPAR)␥-independent mechanism, we used ciglitazone as a scaffold to develop a lead AMPK-activating agent, OSU-53 (18). OSU-53, a PPAR␥-inactive derivative, stimulates AMPK kinase activity through direct activation with high potency, a mechanism distinct from that of metformin (16) or AICAR (19).…”

AMP-Activated Protein Kinase as a Target for Preconditioning in Transplantation Medicine

“…Surprisingly, only few activators of AMPK have been identified and characterized pharmacologically. Several agents currently under investigation in the field of metabolic disorders might also have beneficial effects by limiting injury induced by preservation, because activation of AMPK by aminoimidazole carboxamide ribonucleotide (AICAR), metformin, curcumin, biguanides, and thiazolidinediones has been shown (31)(32)(33)(34)(35). Currently, the most investigated is AICAR.…”