Novel Small Molecules Targeting the Intrinsically Disordered Structural Ensemble of α-Synuclein Protect Against Diverse α-Synuclein Mediated Dysfunctions.

The over-expression and aggregation of α-synuclein (αSyn) are linked to the onset and pathology of Parkinson's disease. Native monomeric αSyn exists in an intrinsically disordered ensemble of interconverting conformations, which has made its therapeutic targeting by small molecules highly challenging. Nonetheless, here we successfully target the monomeric structural ensemble of αSyn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes.

Targeting the intrinsically disordered structural ensemble of α-synuclein by small molecules as a potential therapeutic strategy for Parkinson's disease.

The misfolding of intrinsically disordered proteins such as α-synuclein, tau and the Aβ peptide has been associated with many highly debilitating neurodegenerative syndromes including Parkinson's and Alzheimer's diseases. Therapeutic targeting of the monomeric state of such intrinsically disordered proteins by small molecules has, however, been a major challenge because of their heterogeneous conformational properties. We show here that a combination of computational and experimental techniques has led to the identification of a drug-like phenyl-sulfonamide compound (ELN484228), that targets α-synuclein, a key protein in Parkinson's disease.

Label free fragment screening using surface plasmon resonance as a tool for fragment finding - analyzing parkin, a difficult CNS target.

Surface Plasmon Resonance (SPR) is rarely used as a primary High-throughput Screening (HTS) tool in fragment-based approaches. With SPR instruments becoming increasingly high-throughput it is now possible to use SPR as a primary tool for fragment finding. SPR becomes, therefore, a valuable tool in the screening of difficult targets such as the ubiquitin E3 ligase Parkin.

Development of a novel β-secretase binding assay using the AlphaScreen platform.

Alzheimer's disease (AD) is a devastating neurodegenerative disease affecting millions of people. β-secretase-1 (BACE1), an enzyme involved in the processing of the amyloid precursor protein (APP) to form Aβ is a validated target for AD. Herein, the authors develop and validate a novel binding assay for BACE1 using the AlphaScreen platform that is amenable for high-throughput screening (HTS).

Antimalarial activity of natural product extracts from Papua New Guinean and Australian plants against Plasmodium falciparum.

In the search for new antimalarial compounds, a subset of a natural product extract library prepared from plant samples collected from Papua New Guinea and Australia was screened for in vitro activity against the chloroquine-sensitive 3D7 and chloroquine-resistant Dd2 strains of Plasmodium falciparum. Using the incorporation of ((3)H)-hypoxanthine into parasite nucleic acid as a marker of growth, 93 of the 794 extracts screened displayed >40% inhibition against 3D7 infected erythrocytes at 312 microge/mL. Antimalarial activity was confirmed in 48 of these extracts against both 3D7 and Dd2 infected erythrocytes at concentrations between 78 and 390 microge/mL, 14 of which caused >90% growth inhibition of 3D7 at the lowest concentration screened.

Isoform-specific activation of latent transforming growth factor beta (LTGF-beta) by reactive oxygen species.

The three mammalian transforming growth factor beta (TGF-beta) isoforms are each secreted in a latent complex in which TGF-beta homodimers are non-covalently associated with homodimers of their respective pro-peptide called the latency-associated peptide (LAP). Release of TGF-beta from its LAP, called activation, is required for binding of TGF-beta to cellular receptors, making extracellular activation a critical regulatory point for TGF-beta bioavailability. Our previous work demonstrated that latent TGF-beta1 (LTGF-beta1) is efficiently activated by ionizing radiation in vivo and by reactive oxygen species (ROS) generated by Fenton chemistry in vitro.

Inhibition of transforming growth factor-beta1 signaling attenuates ataxia telangiectasia mutated activity in response to genotoxic stress.

Ionizing radiation causes DNA damage that elicits a cellular program of damage control coordinated by the kinase activity of ataxia telangiectasia mutated protein (ATM). Transforming growth factor beta (TGFbeta)-1, which is activated by radiation, is a potent and pleiotropic mediator of physiologic and pathologic processes. Here we show that TGFbeta inhibition impedes the canonical cellular DNA damage stress response.

Diverse fibrillar peptides directly bind the Alzheimer's amyloid precursor protein and amyloid precursor-like protein 2 resulting in cellular accumulation.

The Alzheimer's disease Abeta peptide can increase the levels of cell-associated amyloid precursor protein (APP) in vitro. To determine the specificity of this response for Abeta and whether it is related to cytotoxicity, we tested a diverse range of fibrillar peptides including amyloid-beta (Abeta), the fibrillar prion peptides PrP106-126 and PrP178-193 and human islet-cell amylin. All these peptides increased the levels of APP and amyloid precursor-like protein 2 (APLP2) in primary cultures of astrocytes and neurons.

Alzheimer's disease amyloid beta and prion protein amyloidogenic peptides promote macrophage survival, DNA synthesis and enhanced proliferative response to CSF-1 (M-CSF).

Microglial cells, macrophage-lineage cells in the brain, are increased in amyloid-containing plaques in Alzheimer's disease (AD) and in the lesions of prion diseases. Recent studies suggest that microglia have a central role in turnover of amyloid in these diseases. We report here that synthetic amyloid beta (Abeta) 1-42 and prion protein (PrP) 106-126 peptides promote macrophage survival; they also induce macrophage DNA synthesis, particularly in the presence of sub-optimal concentrations of the growth factor, macrophage-colony stimulating factor (M-CSF or CSF-1).