pyrimidinones and Cerebral-Infarction

The aim of this study was to investigate the therapeutic efficacy and neuroprotective mechanisms of UCF-101, a novel Omi/HtrA2 inhibitor, following ischemia/reperfusion brain injury. Male Wistar rats were subjected to 2 hr of middle cerebral artery occlusion followed by reperfusion. Animals were divided into 3 groups: sham, vehicle-treated ischemia/reperfusion, and UCF-101 treatment. In the UCF-101 treatment group, rats were intraperitoneally administered UCF-101 (1.5 micromol/kg) 10 min prior to reperfusion. The rats were evaluated for neurological deficits, and brain infarct volume was assessed by 2,3,5-triphenyl tetrazolium chloride. TUNEL staining was utilized to evaluate the amount of apoptosis. In addition, expressions of protein caspase-8, caspase-3, FasL, and FLIP were examined by Western blot analysis. Results demonstrated that UCF-101 treatment significantly decreased cerebral infarct size by about 16.27% (P < 0.05) and also improved neurological behavior. TUNEL staining revealed that UCF-101 treatment significantly reduced TUNEL-positive cells in the cerebral cortex. Furthermore, the upregulation in the expression of FasL and the cleavage products of active caspase-8 and caspase-3 induced by ischemia was attenuated in mice treated with UCF-101, whereas upregulation of FLIP levels was increased. The present results demonstrated that UCF-101 protects against cerebral ischemia/reperfusion injury in mice. UCF-101 provided neuroprotection in vivo, and this was correlated with regulation of Fas-mediated apoptotic proteins. Taken together, the use of UCF-101 is a potent, neuroprotective factor for the treatment of focal cerebral ischemia.

Topics: Animals; Apoptosis; Blotting, Western; Brain Ischemia; Caspase 3; Caspase 8; Cerebral Infarction; Enzyme Inhibitors; High-Temperature Requirement A Serine Peptidase 2; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Male; Mitochondrial Proteins; Nerve Tissue Proteins; Neuroprotective Agents; Pyrimidinones; Rats; Rats, Wistar; Reperfusion Injury; RNA-Binding Proteins; Serine Endopeptidases; Serine-Arginine Splicing Factors; Thiones

We investigated the pharmacological profiles of DR2313 [2-methyl-3,5,7,8-tetrahydrothiopyrano[4,3-d]pyrimidine-4-one], a newly synthesized poly(ADP-ribose) polymerase (PARP) inhibitor, and its neuroprotective effects on ischemic injuries in vitro and in vivo. DR2313 competitively inhibited poly(ADP-ribosyl)ation in nuclear extracts of rat brain in vitro (K(i) = 0.23 microM). Among several NAD(+)-utilizing enzymes, DR2313 was specific for PARP but not selective between PARP-1 and PARP-2. DR2313 also showed excellent profiles in water solubility and rat brain penetrability. In in vitro models of cerebral ischemia, exposure to hydrogen peroxide or glutamate induced cell death with overactivation of PARP, and treatment with DR2313 reduced excessive formation of poly(ADP-ribose) and cell death. In both permanent and transient focal ischemia models in rats, pretreatment with DR2313 (10 mg/kg i.v. bolus and 10 mg/kg/h i.v. infusion for 6 h) significantly reduced the cortical infarct volume. To determine the therapeutic time window of neuroprotection by DR2313, the effect of post-treatment was examined in transient focal ischemia model and compared with that of a free radical scavenger, MCI-186 (3-methyl-1-phenyl-2-pyrazolone-5-one). Pretreatment with MCI-186 (3 mg/kg i.v. bolus and 3 mg/kg/h i.v. infusion for 6 h) significantly reduced the infarct volume, whereas the post-treatment failed to show any effects. In contrast, post-treatment with DR2313 (same regimen) delaying for 2 h after ischemia still prevented the progression of infarction. These results indicate that DR2313 exerts neuroprotective effects via its potent PARP inhibition, even when the treatment is initiated after ischemia. Thus, a PARP inhibitor like DR2313 may be more useful in treating acute stroke than a free radical scavenger.

Topics: Animals; Antipyrine; Brain; Brain Ischemia; Bridged Bicyclo Compounds, Heterocyclic; Cells, Cultured; Cerebral Infarction; Dose-Response Relationship, Drug; Edaravone; Enzyme Inhibitors; Fluorescent Antibody Technique; Free Radical Scavengers; Glyceraldehyde-3-Phosphate Dehydrogenases; Neuroprotective Agents; Poly(ADP-ribose) Polymerase Inhibitors; Pyrimidinones; Rats; Rats, Wistar; Reactive Oxygen Species; Substrate Specificity; Time Factors