Mutant alpha-synuclein-induced degeneration is reduced by parkin in a fly model of Parkinson's disease.

Parkinson's disease (PD) patients show a characteristic loss of motor control caused by the degeneration of dopaminergic neurons. Mutations in the genes that encode alpha-synuclein and parkin have been linked to inherited forms of this disease. The parkin protein functions as a ubiquitin ligase that targets proteins for degradation. Expression of isoforms of human alpha-synuclein in the Drosophila melanogaster nervous system forms the basis of an excellent genetic model that recapitulates phenotypic and behavioural features of PD. Using this model, we analysed the effect of parkin co-expression on the climbing ability of aging flies, their life span, and their retinal degeneration. We have determined that co-expression of parkin can suppress phenotypes caused by expression of mutant alpha-synuclein. In the developing eye, parkin reduces retinal degeneration. When co-expressed in the dopaminergic neurons, the ability to climb is extended over time. If conserved in humans, we suggest that upregulation of parkin may prove a method of suppression for PD induced by mutant forms of alpha-synuclein.     

Identification and design of a novel series of MGAT2 inhibitors

[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to na?ve, p <0.01) in plasma triacylglycerol (TAG) concentration.     

Involvement of the 2'-5' A pathway in the augmentation of natural killer activity

Pretreatment of human large granular lymphocytes (LGL) or unseparated peripheral blood mononuclear cells with interferon (IFN) resulted in a significant augmentation of natural killer (NK) activity. This increase was paralleled by an increase in the 2'-5'A synthetase activity. In order to investigate the possibility that IFN might be inducing augmentation of NK cells via the 2'-5'A pathway, we tested the effects of nonphosphorylated core material [(A2'p)2A] and of the triphosphorylated form of the 2'-5'A [ppp(A2'p)2A]. The core material had no detectable effect on NK activity. In contrast, when experiments were performed with the triphosphorylated form of 2'-5'A, NK activity was stimulated. In order to achieve activation, permeabilization of LGL with calcium chloride was necessary and, under these conditions, a dose-dependent augmentation of NK activity was seen. However, the calcium treatment had considerable toxic effects on basal levels of NK activity. Collectively, these results suggest that IFN may be inducing augmentation of NK activity via the 2'-5'A pathway. Further studies will be necessary to determine the effects of IFN and/or 2'-5'A on subsequent activation steps in the process leading to cytotoxicity by NK cells.