A Novel Pyrazolo[3,4-d]pyrimidine Induces Heme Oxygenase-1 and Exerts Anti-Inflammatory and Neuroprotective Effects

The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin-1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress- and inflammation-related neurodegenerative disorders such as Parkinson's disease.

A novel pyrazolo [3,4-d] pyrimidine, KKC080106, activates the Nrf2 pathway and protects nigral dopaminergic neurons

The transcription factor nuclear factor-erythroid 2-related factor-2 (Nrf2) is known to induce neuroprotective and anti-inflammatory effects and is considered to be an excellent molecular target for drugs related to neurodegenerative disease therapy. Nrf2 activators previously tested in clinical trials were electrophilic, causing adverse effects due to non-selective and covalent modification of cellular thiols. In order to circumvent this issue, we constructed and screened a chemical library consisting of 241 pyrazolo [3,4-d] pyrimidine derivatives and discovered a novel, non-electrophilic compound: 1-benzyl-6-(methylthio)-N-(1-phenylethyl)-1H-pyrazolo[3,4-d]pyrimidine-4-amine (KKC080106). KKC080106 was able to activate Nrf2 signaling as it increases the cellular levels of Nrf2, binds to the Nrf2 inhibitor protein Keap1, and causes the accumulation of nuclear Nrf2. We also observed an increase in the expression levels of Nrf2-dependent genes for antioxidative/neuroprotective enzymes in dopaminergic neuronal cells. In addition, in lipopolysaccharide-activated microglia, KKC080106 suppressed the generation of the proinflammatory markers, such as IL-1β, TNF-α, cyclooxygenase-2, inducible nitric oxide synthase, and nitric oxide, and inhibited the phosphorylation of kinases known to be involved in inflammatory signaling, such as IκB kinase, p38, JNK, and ERK. As a drug, KKC080106 exhibited excellent stability against plasma enzymes and a good safety profile, evidenced by no mortality after the administration of 2000 mg/kg body weight, and minimal inhibition of the hERG channel activity. Pharmacokinetic analysis revealed that KKC080106 has good bioavailability and enters the brain after oral and intravenous administration, in both rats and mice. In MPTP-treated mice that received KKC080106 orally, the compound blocked microglial activation, protected the nigral dopaminergic neurons from degeneration, and prevented development of the dopamine deficiency-related motor deficits. These results suggest that KKC080106 has therapeutic potential for neurodegenerative disorders such as Parkinson's disease.

1013 Cardiovascular Biomarkers and Pathophysiological Insights into Obstructive Sleep Apnea During Acute Coronary Syndrome

Introduction

Obstructive sleep apnea (OSA) is prevalent and carries prognostic implication in patients with acute coronary syndrome (ACS). The relative contribution of pathophysiological mechanisms in ACS towards OSA is not well-studied. We examined the correlation between severity of OSA and myocardial necrosis, inflammation, wall stress, and fibrosis.

Methods

A total of 89 patients admitted with ACS underwent an overnight sleep study during index admission. Plasma levels of peak troponin I, high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded.

Results

The recruited patients were divided into no (AHI <5 events/hour, 9.2%), mild (5-<15, 27.6%), moderate (15-<30, 21.8%), and severe (≥30, 41.4%) OSA. The respective Epworth Sleepiness Scale scores were 3.8±3.7, 5.3±4.9, 4.0±2.8, and 5.5±4.5 (p=0.734). Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p=0.005). They were also more likely to present with ST-segment elevation ACS (vs non-ST-segment elevation ACS) (p=0.041), have undergone previous coronary artery bypass grafting (p=0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p=0.049), and have a larger left atrium diameter measured on echocardiography (p=0.029). Likewise, the severe OSA group had higher plasma levels of troponin I (10584±13078, 11699±20130, 19280±30670, 37571±31269 µg/L; p=0.017), hs-CRP (8.1±9.2, 23.1±52.3, 9.3±17.1, 39.4±44.7 mg/L; p=0.004), and NT-proBNP (667±604, 765±856, 636±728, 1395±1220 pg/mL; p=0.004), but not ST2 (p=0.10). After adjusting for the effects of the confounding variables, severe OSA was independently associated with troponin I (i.e., myocardial necrosis; OR 1.00003, 95% CI 1.000013-1.000048; p=0.001) and NT-proBNP (i.e., myocardial wall stress; OR 1.00081, 95% CI 1.00021-1.00141; p=0.008).

Conclusion

Severe OSA during the acute phase of ACS was associated with extensive myocardial necrosis and myocardial wall stress, but not with inflammation and myocardial fibrosis.

Support

Nil

Synthesis of N-[(3-Amino-1,2-dicarba-closo-dodecaboran-1-yl)acetyl] Derivatives of α-Amino Acids

The N-[(3-amino-1,2-dicarba-closo-dodecaboran-1-yl)acetyl] derivatives of α-amino acids were prepared starting from N-protected (Ac, Form, Bz, and Boc) 3-amino-1-(carboxymethyl)-o-carboranes and alkyl esters of natural α-amino acids using the carbodiimide method of coupling and removing the ester groups. All the amides obtained were diastereoisomeric mixtures. Some diastereoisomers were separated and the assignment of the absolute configuration of aminocarborane fragments was performed by X-ray crystallography.

Mirror-Image Packing in Enantiomer Discrimination

Synthetic chemists often exploit the high enantioselectivity of lipases to prepare pure enantiomers of primary alcohols, but the molecular basis for this enantioselectivity is unknown. The crystal structures of two phosphonate transition-state analogs bound to Burkholderia cepacia lipase reveal this molecular basis for a typical primary alcohol: 2-methyl-3-phenyl-1-propanol. The enantiomeric alcohol moieties adopt surprisingly similar orientations, with only subtle differences that make it difficult to predict how to alter enantioselectivity. These structures, along with a survey of previous structures of enzyme bound enantiomers, reveal that binding of enantiomers does not involve an exchange of two substituent positions as most researchers assumed. Instead, the enantiomers adopt mirror-image packing, where three of the four substituents at the stereocenter lie in similar positions. The fourth substituent, hydrogen, points in opposite directions.

Expression and characterization of a novel enantioselective lipase from Acinetobacter species SY-01

A novel lipase gene, lipase A, of Acinetobacter species SY-01 (A. species SY-01) was cloned, sequenced, and expressed in Bacillus subtilis 168. The deduced amino acid (aa) sequences for the lipase A and its chaperone, lipase-specific chaperone, were found to encode mature proteins of 339 aa (37.2 kDa) and 347 aa (38.1 kDa), respectively. The aa sequence of lipase A and lipase-specific chaperone shared high homology 82 and 67% identity with the lipase A and the lipase B of A. species RAG-1. This new lipase was defined as a group I Proteobacterial lipase family. The expressed lipase A was purified through sequential treatment with Q-Sepharose, Resource Q, and Superdex-S75 columns. The maximal activity was observed at 50 degrees C for hydrolysis of p-nitrophenyl monoesters and found to be stable at pH 9-11, with optimal activity at pH 10. Lipase A hydrolyzed wide range of fatty acid esters of p-nitrophenyl, but preferentially hydrolyzed short length acyl chains (C2 and C4). Moreover, lipase A from A. species SY-01 catalyzed hydrolysis of the two acetate isomers of cis-(+/-)-2-(bromomethyl)-2-(2,4-dichloro phenyl)-1,3-dioxolane-4-methyl acetate, an intermediate required for the synthesis of Itraconazole which was an anti-fungal drug, at different rate and yielded cis-(-)-isomer in 81.5% conversion with 91.9% enantiomeric excess.

Asymmetric synthesis of biologically useful 3,4-disubstitutedgamma- lactone (3,4-db)

3,4-Disubstituted gamma-lactones 9 and 10 were stereoselectively synthesized from 3,4-unsaturated aliphatic alcohol. The synthetic methods of homoallylic alcohol were discussed. Asymmetric dihydroxylation of the double bond was performed by Sharpless' method with (DHQD)2 PHAL or (DHQ)2 PHAL. The stereochemistry of the product was assigned. The (3R,4R)- and (3S,4S)-compounds were obtained with high enantiomeric excess.

Synthesis and antifungal activities of N-aryl-4-phenyl-3-(4-phenoxyphenyl)butanamides

Various N-aryl-4-phenyl-3-(4-phenoxyphenyl)butanamides (2 and 3) were tested for fungicidal activities against Pyricularia oryzae, Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia recondita, and Erysiphe graminis in vivo. Butanamides (2 and 3a) that have an electron withdrawing group (Cl, F) attached to the meta position of the phenyl ring showed good to excellent activities against Pyricularia oryzae, Puccinia recondita, and Erysiphe graminis in high concentration while those that have a strong electron withdrawing group (CN, NO2) or electron donating group (OCH3, CH3) attached to the meta position did not show good activities against all test fungi at 250 mg L-1. The antifungal activities of the compounds synthesized were compared with reference compounds such as Tricyclazole, Moncozeb, and Benomyl.