EMBER multidimensional spectral microscopy enables quantitative determination of disease- and cell-specific amyloid strains.

In neurodegenerative diseases, proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. However, there is a need to rapidly identify amyloid conformations in situ. Here, we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid-binding dyes to identify six distinct different conformational strains in vitro, as well as amyloid-ß (Aß) deposits in different transgenic mouse models. Our EMBER (excitation multiplexed bright emission recording) imaging method rapidly identifies conformational differences in Aß and tau deposits from Down syndrome, sporadic and familial Alzheimer's disease human brain slices. EMBER has in situ identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick's disease. In future studies, EMBER should enable high-throughput measurements of the fidelity of strain transmission in cellular and animal neurodegenerative diseases models, time course of amyloid strain propagation, and identification of pathogenic versus benign strains.

EMBER multi-dimensional spectral microscopy enables quantitative determination of disease- and cell-specific amyloid strains.

In neurodegenerative diseases proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. However, there is a need to rapidly identify amyloid conformations in situ . Here we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid binding dyes to identify six distinct different conformational strains in vitro , as well as Aß deposits in different transgenic mouse models. Our EMBER (excitation multiplexed bright emission recording) imaging method rapidly identifies conformational differences in Aß and tau deposits from Down syndrome, sporadic and familial Alzheimer's disease human brain slices. EMBER has in situ identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick's disease. In future studies, EMBER should enable high-throughput measurements of the fidelity of strain transmission in cellular and animal neurodegenerative diseases models, time course of amyloid strain propagation, and identification of pathogenic versus benign strains. Significance: In neurodegenerative diseases proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. There is a need to rapidly identify these amyloid conformations in situ . Here we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid binding dyes to identify six distinct different conformational strains in vitro , as well as Aß deposits in different transgenic mouse models. Our imaging method rapidly identifies conformational differences in Aß and tau deposits from Down syndrome, sporadic and familial Alzheimer's disease human brain slices. We also identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick's disease. These findings will facilitate the identification of pathogenic protein aggregates to guide research and treatment of protein misfolding diseases.

Simultaneous Inhibition of PGE2 and PGI2 Signals Is Necessary to Suppress Hyperalgesia in Rat Inflammatory Pain Models.

Prostaglandin E2 (PGE2) is well known as a mediator of inflammatory symptoms such as fever, arthritis, and inflammatory pain. In the present study, we evaluated the analgesic effect of our selective PGE2 synthesis inhibitor, compound I, 2-methyl-2-[cis-4-([1-(6-methyl-3-phenylquinolin-2-yl)piperidin-4-yl]carbonyl amino)cyclohexyl] propanoic acid, in rat yeast-induced acute and adjuvant-induced chronic inflammatory pain models. Although this compound suppressed the synthesis of PGE2 selectively, no analgesic effect was shown in both inflammatory pain models. Prostacyclin (PGI2) also plays crucial roles in inflammatory pain, so we evaluated the involvement of PGI2 signaling in rat inflammatory pain models using prostacyclin receptor (IP) antagonist, RO3244019. RO3244019 showed no analgesic effect in inflammatory pain models, but concomitant administration of compound I and RO3244019 showed analgesic effects comparable to celecoxib, a specific cyclooxygenase- (COX-) 2 inhibitor. Furthermore, coadministration of PGE2 receptor 4 (EP4) antagonist, CJ-023423, and RO3244019 also showed an analgesic effect. These findings suggest that both PGE2 signaling, especially through the EP4 receptor, and PGI2 signaling play critical roles in inflammatory pain and concurrent inhibition of both signals is important for suppression of inflammatory hyperalgesia.

A Novel Selective Prostaglandin E2 Synthesis Inhibitor Relieves Pyrexia and Chronic Inflammation in Rats.

Prostaglandin E2 (PGE2) is a terminal prostaglandin in the cyclooxygenase (COX) pathway. Inhibition of PGE2 production may relieve inflammatory symptoms such as fever, arthritis, and inflammatory pain. We report here the profile of a novel selective PGE2 synthesis inhibitor, compound A [N-[(1S,3S)-3-carbamoylcyclohexyl]-1-(6-methyl-3-phenylquinolin-2-yl)piperidine-4-carboxamide], in animal models of pyrexia and inflammation. The compound selectively suppressed the synthesis of PGE2 in human alveolar adenocarcinoma cell line A549 cells and rat macrophages. In the lipopolysaccharide-induced pyrexia model, this compound selectively reduced PGE2 production in cerebrospinal fluid and showed an anti-pyretic effect. In the adjuvant-induced arthritis model, compound A therapeutically decreased foot swelling in the established arthritis. Our data demonstrates that selective suppression of PGE2 synthesis shows anti-pyretic and anti-inflammatory effects, suggesting that selective PGE2 synthesis inhibitors can be applied as an alternative treatment to nonsteroidal, anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors.

A new method for production of chiral 2-aryl-2-fluoropropanoic acids using an effective kinetic resolution of racemic 2-aryl-2-fluoropropanoic acids.

We report a new method for the preparation of chiral 2-aryl-2-fluoropropanoic acids, including 2-fluoroibuprofen, a fluorinated analogue of non-steroidal anti-inflammatory drugs (NSAIDs), by the kinetic resolution of racemic 2-aryl-2-fluoropropanoic acids using enantioselective esterification. By applying pivalic anhydride (Piv2O) as a coupling agent, bis(α-naphthyl)methanol [(α-Np)2CHOH] as an achiral alcohol, and (+)-benzotetramisole (BTM) as a chiral acyl-transfer catalyst, a series of racemic 2-aryl-2-fluoropropanoic acids were kinetically separated to afford the optically active carboxylic acids and the corresponding esters with good to high enantiomeric excesses. This technology can provide a convenient approach to furnish the chiral α-fluorinated drugs containing quaternary carbons at the α-positions in the 2-aryl-2-fluoropropanoic acid structure.

Role of a non-natural beta-C-nucleotide unit in DNA as a template for DNA and RNA syntheses and as a substrate for nucleolytic digestion.

A non-natural beta-C-nucleoside bearing a 3,4-dibenzyloxyphenyl group as a nucleobase (X) was synthesized and incorporated into a 34-mer oligomer with the sequence 5'-dTTTTTAAAAAAXATATAGCAGCGACATGTCACCG-3'. This synthetic oligonucleotide was examined for template activity in the enzymatic syntheses of DNA by the Klenow fragments of Escherichia coli DNA polymerase I and the recombinant DNA polymerase I, and in the synthesis of RNA by the E. coli RNA polymerase core enzyme. As a result, the template-directed polymerization of both DNA and RNA was precisely terminated at the position of X. The X-containing oligonucleotide was also tested for digestion by an exonuclease, Exo III nuclease (Exo III), and an endonuclease, Mung Bean nuclease (MB). The results indicate that the artificial nucleobase X acts as a terminator for digestion by Exo III, whereas the site X becomes susceptible to digestion by MB. These findings provide a useful tool for the size control of products in the synthesis and degradation of nucleic acids.

Artificial metallo-DNA: structural control and discrete metal assembly.

To array Cu2+ ions within a double-stranded DNA along the helix axis in a controllable manner, a series of artificial oligonucleotides, d(5'-GHnC-3') (n = 1-5), were synthesized, where H is a hydroxypyridone nucleobase. Right-handed double helices of the oligonucleotides, nCu2+ x d(5'-GHnC-3')2 (n = 1-5), were quantitatively formed through Cu2+-mediated metallo-base pairing (H-Cu2+-H). The Cu2+ ions incorporated into each duplex were aligned along the helix axes with the Cu2+-Cu2+ distance of 3.7 +/- 0.1 A. The unpaired d electrons of the Cu2+ ions were coupled ferromagnetically with one another to form magnetic chains.

A discrete self-assembled metal array in artificial DNA.

DNA has a structural basis to array functionalized building blocks. Here we report the synthesis of a series of artificial oligonucleotides, d(5'-GH(n)C-3') (n = 1 to 5), with hydroxypyridone nucleobases (H) as flat bidentate ligands. Right-handed double helices of the oligonucleotides, nCu2+.d(5'-GH(n)C-3')2 (n = 1 to 5), were quantitatively formed through copper ion (Cu2+)-mediated alternative base pairing (H-Cu2+-H), where the Cu2+ ions incorporated into each complex were aligned along the helix axes inside the duplexes with the Cu2+-Cu2+ distance of 3.7 +/- 0.1 angstroms. The Cu2+ ions were coupled ferromagnetically with one another through unpaired d electrons to form magnetic chains.

Syntheses and structure-activity relationships of nonnatural beta-C-nucleoside 5'-triphosphates bearing an aromatic nucleobase with phenolic hydroxy groups: inhibitory activities against DNA polymerases.

Five nonnatural beta-C-nucleoside 5'-triphosphates bearing a 3,4-dihydroxyphenyl (1TP), a 2-hydroxyphenyl (2TP), a 3-hydroxyphenyl (3TP), a 4-hydroxyphenyl (4TP), or a phenyl (5TP) group were synthesized, and their structure-activity relationships were examined for a series of DNA polymerase reactions in vitro under typical polymerase chain reaction conditions. We found that the 5'-triphosphates (1TP-5TP) are not incorporated into DNA strands but inhibit the DNA polymerase reactions in the presence of natural nucleoside 5'-triphosphates (dNTPs). 1TP having two phenolic hydroxy groups at the nucleobase moiety showed the most potent inhibitory effect against DNA synthesis by Ex Taq polymerase (IC(50) = 30 microM). The competition assay indicated that 1TP and dNTPs are most likely to affect DNA polymerase reactions competitively. This finding may raise the appealing possibility that artificial nucleoside 5'-triphosphates having phenolic hydroxy groups could exhibit potent inhibitory activity against DNA-directed enzymatic reactions.

Efficient incorporation of a copper hydroxypyridone base pair in DNA.

Recently, we reported the first artificial nucleoside for alternative DNA base pairing through metal complexation (J. Org. Chem. 1999, 64, 5002-5003). In this regard, we report here the synthesis of a hydroxypyridone-bearing nucleoside and the incorporation of a neutral Cu(2+)-mediated base pair of hydroxypyridone nucleobases (H-Cu-H) in a DNA duplex. When the hydroxypyridone bases are incorporated into the middle of a 15 nucleotide duplex, the duplex displays high thermal stabilization in the presence of equimolar Cu(2+) ions in comparison with a duplex containing an A-T pair in place of the H-H pair. Monitoring temperature dependence of UV-absorption changes verified that a Cu(2+)-mediated base pair is stoichiometrically formed inside the duplex and dissociates upon thermal denaturation at elevated temperature. In addition, EPR and CD studies suggested that the radical site of a Cu(2+) center is formed within the right-handed double-strand structure of the oligonucleotide. The present strategy could be developed for controlled and periodic spacing of neutral metallobase pairs along the helix axis of DNA.