The 4'-hydroxyl group of resveratrol is functionally important for direct activation of PPARα.

Long-term moderate consumption of red wine is associated with a reduced risk of developing lifestyle-related diseases such as cardiovascular disease and cancer. Therefore, resveratrol, a constituent of grapes and various other plants, has attracted substantial interest. This study focused on one molecular target of resveratrol, the peroxisome proliferator activated receptor α (PPARα). Our previous study in mice showed that resveratrol-mediated protection of the brain against stroke requires activation of PPARα; however, the molecular mechanisms involved in this process remain unknown. Here, we evaluated the chemical basis of the resveratrol-mediated activation of PPARα by performing a docking mode simulation and examining the structure-activity relationships of various polyphenols. The results of experiments using the crystal structure of the PPARα ligand-binding domain and an analysis of the activation of PPARα by a resveratrol analog 4-phenylazophenol (4-PAP) in vivo indicate that the 4'-hydroxyl group of resveratrol is critical for the direct activation of PPARα. Activation of PPARα by 5 µM resveratrol was enhanced by rolipram, an inhibitor of phosphodiesterase (PDE) and forskolin, an activator of adenylate cyclase. We also found that resveratrol has a higher PDE inhibitory activity (IC50 = 19 µM) than resveratrol analogs trans-4-hydroxystilbene and 4-PAP (IC50 = 27-28 µM), both of which has only 4'-hydroxyl group, indicating that this 4'-hydroxyl group of resveratrol is not sufficient for the inhibition of PDE. This result is consistent with that 10 µM resveratrol has a higher agonistic activity of PPARα than these analogs, suggesting that there is a feedforward activation loop of PPARα by resveratrol, which may be involved in the long-term effects of resveratrol in vivo.

6-(4-Pyridyl)pyrimidin-4(3H)-ones as CNS penetrant glycogen synthase kinase-3ß inhibitors.

The discovery of a series of 6-(4-pyridyl)pyrimidin-4(3H)-ones derived from a hit compound with low molecular weight and sufficient chemical space is reported. Transformation of substituents led to subnanomolar potent inhibitors with in vivo tau phoshorylation lowering activity.

Prediction of the binding affinity of compounds with diverse scaffolds by MP-CAFEE.

Accurate methods to predict the binding affinities of compounds for target molecules are powerful tools in structure-based drug design (SBDD). A recently developed method called massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) successfully predicted the binding affinities of compounds with relatively similar scaffolds. We investigate the applicability of MP-CAFEE for predicting the affinity of compounds having more diverse scaffolds for the target p38α, a mitogen-activated protein kinase. The calculated and experimental binding affinities correlate well, showing that MP-CAFEE can accurately rank the compounds with diverse scaffolds. We propose a method to determine the optimal number of sampling runs with respect to a predefined level of accuracy, which is established according to the stage in the SBDD process being considered. The optimal number of sampling runs for two key stages-lead identification and lead optimization-is estimated to be five and eight or more, respectively, in our model system using Cochrans sample size formula.

Lead generation and optimization based on protein-ligand complementarity.

This work proposes a computational procedure for structure-based lead generation and optimization, which relies on the complementarity of the protein-ligand interactions. This procedure takes as input the known structure of a protein-ligand complex. Retaining the positions of the ligand heavy atoms in the protein binding site it designs structurally similar compounds considering all possible combinations of atomic species (N, C, O, CH(3), NH, etc). Compounds are ranked based on a score which incorporates energetic contributions evaluated using molecular mechanics force fields. This procedure was used to design new inhibitor molecules for three serine/threonine protein kinases (p38 MAP kinase, p42 MAP kinase (ERK2), and c-Jun N-terminal kinase 3 (JNK3)). For each enzyme, the calculations produce a set of potential inhibitors whose scores are in agreement with IC50 data and Ki values. Furthermore, the native ligands for each protein target, scored within the five top-ranking compounds predicted by our method, one of the top-ranking compounds predicted to inhibit JNK3 was synthesized and his inhibitory activity confirmed against ATP hydrolysis. Our computational procedure is therefore deemed to be a useful tool for generating chemically diverse molecules active against known target proteins.

ASK3, a novel member of the apoptosis signal-regulating kinase family, is essential for stress-induced cell death in HeLa cells.

Apoptosis signal-regulating kinase 1 (ASK1) and ASK2 are both members of mitogen-activated protein kinase kinase kinase (MAP3K) family that are implicated in apoptotic cell death, stress responses, and various diseases. We have determined that NT2RI3007443, TESTI4031745, SGK341, and human MAP3K15 are all transcribed from the same genomic locus, which we designate "ASK3 gene" based on sequence homology to ASK1 and ASK2. NT2RI3007443, TESTI4031745, and SGK341 displayed distinct expression profiles among human tissues. TESTI4031745 was expressed in relatively high levels. The expression of TESTI4031745 was increased in rectum tumor and Alzheimer's disease hippocampus and decreased in kidney tumor and Alzheimer's disease frontal lobe. NT2RI3007443 showed moderate levels of ubiquitous expression in normal adult tissues. They did not drastically change in diseases except for increase in cirrhosis liver. Expression of SGK341 was restricted. It was highly expressed in fetal brain, and moderately expressed in normal hippocampus, pancreas, spleen, lung, and kidney. Further, its expression was dramatically increased in hepatic cirrhosis and decreased in lung tumor. Target proteins encoded by NT2RI3007443 and TESTI4031745 were translated in cell-free protein synthesis system. They exhibited protein kinase activity indicated by ATP consumption and phosphorylation of Syntide 2 as a substrate. We demonstrated that knockdown of ASK3 protected HeLa cells against cytotoxicity induced by anti-Fas monoclonal antibody, TNF-alpha, or oxidative stress. These findings suggest that "ASK3 gene" is a novel member of apoptosis signal-regulating kinases and that it plays a pivotal role in the signal transduction pathway implicated in apoptotic cell death triggered by cellular stresses. It can be a putative therapeutic drug target for multiple human diseases.