Novel Small-Molecule AMP-Activated Protein Kinase Allosteric Activator with Beneficial Effects in db/db Mice

Abstract

AMP-activated protein kinase (AMPK) is an energy sensor of metabolism that is an attractive therapeutic target for type 2 diabetes mellitus and metabolic syndrome. Using a homogeneous scintillation proximity assay (SPA), we identified a new small-molecule AMPK activator, ZLN024, which allosterically stimulated active AMPK heterotrimers and the inactive α1 subunit truncations α1 (1–394) and α1 (1–335) but not α1 (1–312). AMPK activation by ZLN024 requires the pre-phosphorylation of Thr-172 by at least one upstream kinase and protects AMPK Thr-172 against dephosphorylation by PP2Cα. ZLN024 activated AMPK in L6 myotubes and stimulated glucose uptake and fatty acid oxidation without increasing the ADP/ATP ratio. ZLN024 also activated AMPK in primary hepatocytes, decreased fatty acid synthesis and glucose output. Treatment of db/db mice with 15 mg/kg/day ZLN024 improved glucose tolerance; liver tissue weight, triacylglycerol and the total cholesterol content were decreased. The hepatic transcriptional level of G6Pase, FAS and mtGPAT were reduced. The transcription of genes involved in fatty acid oxidation and the mitochondrial biogenesis of muscle tissue were elevated. The ACC phosphorylation was increased in muscle and liver. This study provides a novel allosteric AMPK activator for functional study in vitro and in vivo and demonstrates that AMPK allosteric activators could be a promising therapeutic approach for type 2 diabetes mellitus and metabolic syndrome.

Mitochondrial Hormesis and Diabetic Complications

“…These include metformin (106), angiotensin II receptor blockers (107), and aspirin (108). Other newer drugs have potent AMPK activity and may also be beneficial for diabetes complications (109). …”

Anti-inflammatory agents to treat or prevent type 2 diabetes, metabolic syndrome and cardiovascular disease

“…CNX-012-570, a highly potent and orally bioavailable compound activating AMPK, has shown its potential to control hyperglycemia and hyperlipidemia as well as to reduce body weight gain with an additional benefit of minimizing cardiovascular risk factors in both diet-induced obese mice and db/db mice models [147]. Treatment of db/ db mice with ZLN024, a novel small-molecule AMPK allosteric activator, improved glucose tolerance and reduced liver tissue weight as well as triacylglycerol and total cholesterol content [148]. These preliminary results in animals confirm that AMPK is an attractive therapeutic target for T2DM, obesity and MetS, but future clinical trials are required to test the benefit/risk balance of this new approach in patients with T2DM [145].…”

“…Indeed, T2DM is a complex disease, whose treatment generally requires a combination of several drugs that target insulin secretion, insulin action or insulin-independent [148] ZLN024…”

Novel targets of antifibrotic and anti-inflammatory treatment in CKD

“…For example, ZNL024 (a small-molecule allosteric activator of AMPK) has beneficial effects in mice. 119 In this study, Lepr db/db diabetic mice treated with ZNL024 demonstrated improved glucose tolerance, reduced liver weight, and decreased liver content of total cholesterol and triacylglycerol. 119 Valproic acid, a potent antiepileptic agent, is effective in activating AMPK in vitro and in vivo.…”