This review describes recent developments in the search for effective therapeutic agents that target redox homeostasis in neurodegenerative disease. The disruption to thiol redox homeostasis in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis is discussed, together with the experimental strategies that are aimed at preventing, or at least minimizing, oxidative damage in these diseases. Particular attention is given to the potential of increasing antioxidant capacity by targeting the Nrf2 pathway, the development of inhibitors of NADPH oxidases that are likely candidates for clinical use, together with strategies to reduce nitrosative stress and mitochondrial dysfunction. We describe the shortcomings of compounds that hinder their progression to the clinic and evaluate likely avenues for future research. LINKED ARTICLESThis article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc Abbreviations 6(OH)DA, 6-hydroxydopamine; AD, Alzheimer's disease; ADME(T), absorption, distribution, metabolism and excretion/toxicity; ALS, amyotrophic lateral sclerosis; APP, amyloid precursor protein; ARE, antioxidant response element; ASSNAC, S-allylmercapto-N-acetyl cysteine; Aβ, amyloid-β; CA, carnosic acid; DMF, dimethylfumarate; EAE, experimental autoimmune encephalomyelitis; EpRE, electrophile response element; GCL, glutamate cysteine ligase; GR, glutathione reductase; Grx, glutaredoxin; GSK-3β, glycogen synthase kinase-3β; Keap1, Kelch-like ECH-associated protein-1; MMF, monomethylfumarate; MPTP, 1-methyl, 4-phenyl-1,2,3,6-tetrahydropyridine; MS, multiple sclerosis; MPO, myeloperoxidase; NAC, N-acetylcysteine; NACA, N-acetylcysteine amide; NOX, NADPH oxidase; NQO1, NAD(P)H quinone oxidoreductase-1; Nrf2, nuclear factor (erythroid-derived 2)-like 2; PD, Parkinson's disease; PS1, pre-senelin-1; RNS, reactive nitrogen species; SN, substantia nigra; Trx, thioredoxin; TrxR, thioredoxin reductase; xCT, functional subunit of the x c À exchanger Disruption of cerebral redox homeostasis is a common occurrence in a range of human neurodegenerative disorders, and although much is understood of mechanistic dysfunction, the gap between knowledge and the availability of effective therapies remains wide. In this review, we focus on the potential for developing therapeutic agents that promote the availability of thiol redox antioxidants or boost the antioxidant capacity of cells via stimulation of the transcription factor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In addition, we discuss options for reducing ROS production by inhibition of NADPH oxidases (NOXs), limiting nitrative stress or targeting mitochondrial dysfunction. Other potential strategies for limiting oxidative stress in neurodegenerative disease include nutrient and vitamin supplementation and metal chelators, which are excluded from the discussion. These approaches are t...

3-(4-Fluorophenyl)-2-(4-pyridyl)chromone derivatives were synthesized and evaluated as p38 MAP kinase inhibitors. Introduction of an amino group in the 2-position of the pyridyl moiety gave p38α inhibitors with IC(50) in the low nanomolar range (e.g., IC(50) = 17 nm). The inhibitors showed excellent selectivity profiles when tested on a panel of 62 kinases, as well as efficient inhibition of p38 signaling in human breast cancer cells.

There is a strong potential for the development of ROS-inducing drugs, targeting the NOX2 complex, which are effective and safe, for the treatment of inflammatory autoimmune disorders. In such drug development, one must carefully investigate the pharmaceutical properties, including both efficacy and safety of the drugs. In addition, the immunological pathways of this new treatment strategy need careful examination.

Synthetic glycolipids with defined structures are important tools in the study of glycolipid biology. In this paper we describe a solid-phase synthesis of three galactosylated serine-based glycosphingolipid analogues using the novel linker 2-fluoro-4-(hydroxymethyl)-phenoxyacetic acid. Gel-phase (19)F-NMR spectroscopy was used to measure the yield and stereochemical outcome of the solid-phase glycosylations. Under NIS-TfOH promotion, alpha- and beta-selective glycosylations were performed at room temperature with thioglycoside donors carrying fluorine labelled protective groups. Finally, the glycolipids were covalently linked to microtiter plates and labelled lectins with different selectivity for alpha- and beta-galactosides could bind to the glycolipid arrays.

The reducing end of protected carbohydrates can be equipped with a series of aglycones via the photochemical installation of a 3-mercaptoethanol linker. This linker is stable during chemical and enzymatic glycosylation reactions but can be activated readily and efficiently to couple oligosaccharides with different nucleophiles. This approach provides straightforward access to a range of molecules that serve as probes for carbohydrate modifying enzymes. [reaction: see text].

An efficient method to synthesize positional scanning synthetic combinatorial libraries (PS-SCLs) for studying the specificity of protein kinases is presented. Isokinetic ratios for pentafluorophenyl esters were determined iteratively using a new approach incorporating high performance liquid chromatography (HPLC) quantification and statistical experimental design. In the development process a large amount of work was put in to find efficient ways of screening for new isokinetic mixtures and to optimize the process of PS-SCL synthesis. The newly developed methods for the screening of isokinetic mixtures could be used for the screening of other interesting mixtures, but more importantly, the isokinetic ratios determined for the preactivated pentafluorophenyl esters were incorporated into a new efficient protocol. This straightforward protocol allows for a convenient synthesis of high quality PS-SCLs regardless of previous experience in solid phase synthesis.

CD1 proteins present mammalian and microbial lipid and glycolipid antigens to different subsets of T cells. Few such antigens have been identified and the binding of these to CD1 molecules has mainly been studied by using responding T cells in cellular assays or recombinant solid-phase CD1 proteins. In the present study we use four different glycolipids, some of which contain tumor-associated carbohydrate antigens, to develop a procedure to easily detect binding of glycolipids to CD1 proteins on viable cells. Two of these glycolipids are novel glycoconjugates containing alpha-D-N-acetylgalactosamine (alpha-GalNAc) that were prepared by a combined solution and solid-phase approach. The key step, a Fischer glycosylation of 9-fluorenylmethoxycarbonylaminoethanol with GalNAc, furnished the alpha-glycoside 4 in 34% yield. Cells were incubated with glycolipids and stained with monoclonal antibodies specific for the carbohydrate part. The level of glycolipid bound to cells was then determined by flow cytometry with a secondary antibody labeled with fluorescein isothiocyanate. All four glycolipids were found to bind to CD1d but with different selectivity. The loading was dose dependent and could be inhibited by an established CD1d ligand, alpha-galactosylceramide. Through use of this procedure, glycolipids were selectively loaded onto CD1d expressed on professional antigen-presenting cells for future use as cellular vaccines. Moreover, the glycolipids described in this study represent novel CD1d-binding ligands that will be useful derivatives in the study of CD1d-dependent immune responses, for example, against tumors.

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