Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice.

AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated.

Novel small-molecule AMP-activated protein kinase allosteric activator with beneficial effects in db/db mice.

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.

Cytotoxic amide alkaloids from Piper boehmeriaefolium.

Eight new amide alkaloids (1-8) and 19 known ones were isolated from the whole plant of Piper boehmeriaefolium. Their structures were determined through spectroscopic data analyses. Cytotoxic activity of these amides against human cervical carcinoma HeLa cells was evaluated, and 1-[(9E)-10-(3,4-methylenedioxyphenyl)-9-decenoyl]pyrrolidine (9) exhibited significant inhibitory activity with an IC(50) value of 2.

AMPK activators as novel therapeutics for type 2 diabetes.

AMPK is a potential target of metabolic diseases including obesity and type 2 diabetes. The activation of AMPK can lead to an increase of glucose uptake into muscle, decreased gluconeogenesis in liver, increased fatty acid oxidation in muscle and liver, decreased fatty acid synthesis in liver and adipose tissue, and increase mitochondrial biogenesis. Until now, many efforts from industrial and academia have been focused on searching novel agents that activate AMPK directly or indirectly.

High-throughput assay for modulators of mitochondrial membrane potential identifies a novel compound with beneficial effects on db/db mice.

Objective: Recently, several drugs have been shown to exert beneficial effects for metabolic syndrome through mild regulation of mitochondrial function. Hence, we explored a strategy of targeting mitochondrial function to improve glucose and lipid metabolism.

Research Design And Methods: Mitochondrial membrane potential (Deltapsim) is a marker of mitochondrial function; therefore, we set up a high-throughput screening assay of Deltapsim in L6 myotubes.

Isoquinoline-1,3,4-trione derivatives inactivate caspase-3 by generation of reactive oxygen species.

Caspase-3 is an attractive therapeutic target for treatment of diseases involving disregulated apoptosis. We report here the mechanism of caspase-3 inactivation by isoquinoline-1,3,4-trione derivatives. Kinetic analysis indicates the compounds can irreversibly inactivate caspase-3 in a 1,4-dithiothreitol (DTT)- and oxygen-dependent manner, implying that a redox cycle might take place in the inactivation process.

Small molecule antagonizes autoinhibition and activates AMP-activated protein kinase in cells.

AMP-activated protein kinase (AMPK) serves as an energy sensor and is considered a promising drug target for treatment of type II diabetes and obesity. A previous report has shown that mammalian AMPK alpha1 catalytic subunit including autoinhibitory domain was inactive. To test the hypothesis that small molecules can activate AMPK through antagonizing the autoinhibition in alpha subunits, we screened a chemical library with inactive human alpha1(394) (alpha1, residues 1-394) and found a novel small-molecule activator, PT1, which dose-dependently activated AMPK alpha1(394), alpha1(335), alpha2(398), and even heterotrimer alpha1beta1gamma1.

Construction of a small peptide library related to inhibitor OM99-2 and its structure-activity relationship to beta-secretase.

Aim: To develop probes for detecting the binding specificity between beta-secretase and substrate, and provide reliable biological activity data for further researching encircling substrate-based inhibitors.

Methods: To prepare the inhibitors, the hydroxyethylene (HE) segment including P1 and P1'was synthesized after multi-step reactions; the combination of all segments was then completed through solid phase synthesis. Recombinant human beta-secretase ectodomain (amino acid residues 1-460) was expressed as a secreted protein with a C-terminal His tag in insect cells using baculovirus infection, and all compounds were evaluated in this beta-secretase enzyme assay.

Conserved alpha-helix acts as autoinhibitory sequence in AMP-activated protein kinase alpha subunits.

AMP-activated protein kinase (AMPK) acts as an energy sensor, being activated by metabolic stresses and regulating cellular metabolism. AMPK is a heterotrimer consisting of a catalytic alpha subunit and two regulatory subunits, beta and gamma. It had been reported that the mammalian AMPK alpha subunit contained an autoinhibitory domain (alpha1: residues 313-392) and had little kinase activity.