Adult neural stem cells expressing IL-10 confer potent immunomodulation and remyelination in experimental autoimmune encephalitis

Adult neural stem cells (aNSCs) derived from the subventricular zone of the brain show therapeutic effects in EAE, an animal model of the chronic inflammatory neurodegenerative disease MS; however, the beneficial effects are modest. One critical weakness of aNSC therapy may be an insufficient antiinflammatory effect. Here, we demonstrate that i.v. or i.c.v. injection of aNSCs engineered to secrete IL-10 (IL-10–aNSCs), a potent immunoregulatory cytokine, induced more profound functional and pathological recovery from ongoing EAE than that with control aNSCs. IL-10–aNSCs exhibited enhanced antiinflammatory effects in the periphery and inflammatory foci in the CNS compared with control aNSCs, more effectively reducing myelin damage, a hallmark of MS. When compared with mice treated with control aNSCs, those treated with IL-10–aNSCs demonstrated differentiation of transplanted cells into greater numbers of oligodendrocytes and neurons but fewer astrocytes, thus enhancing exogenous remyelination and neuron/axonal growth. Finally, IL-10–aNSCs converted a hostile environment to one supportive of neurons/oligodendrocytes, thereby promoting endogenous remyelination. Thus, aNSCs engineered to express IL-10 show enhanced ability to induce immune suppression, remyelination, and neuronal repair and may represent a novel approach that can substantially improve the efficacy of neural stem cell–based therapy in EAE/MS.

A potent novel antimicrobial peptide related to caerin 1.12 from the skin secretion of the Australian frog, Litoria aurea

Skin secretions from Australian frogs of the genus Litoria have been extensively studied for many years and are known to contain a large array of antimicrobial peptides that often bear their specific names — caerins (L. caerulea), aureins (L. aurea), citropins (L. citropa) and maculatins (L. genimaculata) — and each group displays distinct primary structural attributes. During a systematic transcriptome cloning study using a cDNA library derived from skin secretion of L. aurea, a series of identical clones were identified that encoded a novel 25-mer antimicrobial peptide that displayed 92% structural identity with caerin 1.12 from L. caerulea, differing in amino acid sequence at only two positions — Arg for Gly at position 7 and Leu amide for Ser amide at the C-terminus. The novel peptide had conserved Pro residues at positions 15 and 19 that flank a flexible hinge region which previous studies have suggested are important for effective orientation of the two alpha-helices within the bacterial membrane resulting in lysis of cells. As the two substitutions in the novel peptide serve to increase both positive charge and hydrophobicity, we synthesised a replicate and determined its minimal inhibitory concentration (MIC) against Gram positive Staphylococcus aureus and Gram negative Escherichia coli. The MICs for these organisms were 3 µM and 4 µM, respectively, indicating a high potency and haemolysis was

A novel and potent trypsin inhibitor peptide, AC-17, from the skin secretion of the edible frog, Rana esculenta

Protease inhibitors are found in many venoms and evidence suggests that they occur widely in amphibian skin secretions. Kunitz inhibitors have been found in the skin secretions of bombinid toads and ranid frogs, Kazal inhibitors in phyllomedusine frogs and Bowman–Birk inhibitors in ranid frogs. Selective protease inhibitors could have important applications as therapeutics in the treatment of diseases in which discrete proteases play an aetiologcal role. Here we have examined the skin secretion of the edible frog, Rana esculenta, for protease inhibitors using trypsin as a model. HPLC fractions of secretions were screened for inhibitory activity using a chromogenic substrate as reporter. Three major peptides were resolved with trypsin inhibitory activity in HPLC fractions — one was a Kunitz-type inhibitor, a second was a Bowman–Birk inhibitor but the third represented a novel class of trypsin inhibitor in European frog skin. Analysis of the peptide established the structure of a 17-mer with an N-terminal Ala (A) residue and a C-terminal Cys (C) residue with a single disulphide bridge between Cys 12 and 17. Peptide AC-17 resembled a typical “Rana box” antimicrobial peptide but while it was active against Escherichia coli (MIC 30 µM) it was devoid of activity against Staphylococcus aureus and of haemolytic activity. In contrast, the peptide was a potent inhibitor of trypsin with a Ki of 5.56 µM. AC-17 represents the prototype of a novel trypsin inhibitor from the skin secretion of a European ranid frog that may target a trypsin-like protease present on the surface of Gram-negative bacteria.

Discovery and Evaluation of BMS-708163, a Potent, Selective and Orally Bioavailable gamma-Secretase Inhibitor

During the course of our research efforts to develop a potent and selective gamma-secretase inhibitor for the treatment of Alzheimer's disease, we investigated a series of carboxamide-substituted sulfonamides. Optimization based on potency, Notch/amyloid-beta precursor protein selectivity, and brain efficacy after oral dosing led to the discovery of 4 (BMS-708163). Compound 4 is a potent inhibitor of gamma-secretase (A beta 40 IC50 = 0.30 nM), demonstrating a 193-fold selectivity against Notch. Oral administration of 4 significantly reduced A beta 40 levels for sustained periods in brain, plasma, and cerebrospinal fluid in rats and dogs.

5-aryl-pyrazolo[3,4-b]pyridazines: Potent inhibitors of glycogen synthase kinase-3 (GSK-3)

Introduction of a nitrogen atom into the 6-position of a series of pyrazolo[3,4-b]pyridines led to a dramatic improvement in the potency of GSK-3 inhibition. Rationalisation of the binding mode suggested participation of a putative structural water molecule, which was subsequently confirmed by X-ray crystallography. (C) 2003 Elsevier Science Ltd. All rights reserved.

3-anilino-4-arylmaleimides: Potent and selective inhibitors of glycogen synthase kinase-3 (GSK-3)

Potent 3-anilino-4-arylmaleimide glycogen synthase kinase-3 (GSK-3) inhibitors have been prepared using automated array methodology. A number of these are highly selective, having little inhibitory potency against more than 20 other protein kinases. (C) 2001 Elsevier Science Ltd. All rights reserved.

[[omega-(Heterocyclylamino)alkoxy]benzyl]-2,4-thiazolidinediones as potent antihyperglycemic agents.

A series of [(ureidoethoxy)benzyl]-2,4-thiazolidinediones and [[(heterocyclylamino)alkoxy]benzyl]-2,4-thiazolidinediones was synthesized from the corresponding aldehydes. Compds. from the urea series, exemplified by I, showed antihyperglycemic potency comparable with known agents of the type such as pioglitazone and troglitazone (CS-045). The benzoxazole II, a cyclic analog of I, was a very potent enhancer of insulin sensitivity, and by modification of the arom. heterocycle, an aminopyridine, III, was identified as a lead compd. from SAR studies. Evaluation of antihyperglycemic activity together with effects on blood Hb content, to det. the therapeutic index, was performed in 8-day repeat administration studies in genetically obese C57 B1/6 ob/ob mice. From these studies, III (BRL 49653) has been selected, on the basis of antihyperglycemic potency combined with enhanced selectivity against redns. in blood Hb content, for further evaluation.

The synthesis of BRL 49653 - a novel and potent antihyperglycemic agent.

Modifications based upon a metabolite of ciglitazone afforded BRL 49653 (I), a novel potent insulin sensitizer. A facile synthesis of this compd. is described.

Sunlight exposure, antioxidants, and age-related macular degeneration

Objective: To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD). Methods: Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data. Results: Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level - vitamin C, zeaxanthin, vitamin E, and dietary zinc - with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD. Conclusions: Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients. ©2008 American Medical Association. All rights reserved.