Although alpha-synuclein is thought to play a central role in the pathogenesis of several neurodegenerative diseases including

Parkinson’s disease, multiple system atrophy, and diffuse Lewy body disease, the mechanism of action is not completely understood. In this study, we sought to determine whether multiple factors act together with alpha-synuclein to engender cell vulnerability through an augmentation of membrane conductance. In this article, we employed a cell model that mimics dopaminergic neurons coupled with alpha-synuclein overexpression and oxidative stressors. We demonstrate an enhancement of alpha-synuclein-induced toxicity in the presence of combined treatment with dopamine and paraquat, two molecules known to incite oxidative stress. In addition, we show that combined dopamine and paraquat treatment increases the expression selleckchem of heme oxygenase-1, an antioxidant A-1155463 purchase response protein. Finally, we demonstrate for the first time that combined treatment of dopaminergic cells with paraquat

and dopamine enhances alpha-synuclein-induced leak channel properties resulting in increased membrane conductance. Importantly, these increases are most robust when both paraquat and dopamine are present suggesting the need for multiple oxidative insults to augment alpha-synuclein-induced disruption of membrane integrity.”
“The permeabilities of amino acids for isolated cuticular membranes of ivy (Hedera helix L.) were measured at different pH. Cuticular permeances were lowest for the zwitterionic form at pH 6, followed by the cationic form at pH 1. Highest permeances were obtained for the anionic form at pH 11. Permeances were not correlated with octanol/water

partition coefficients and decreased at DMH1 a given pH with increasing molar volume of the solute. This finding suggests that permeation takes place in the polar cuticular pathways. The effect of pH on the cuticular transport properties was analysed according to the porous membrane model considering the polyelectrolytic character of the cuticle in terms of porosity, tortuosity, and size selectivity of the aqueous cuticular pathway which is altered by pH. An increase of water content and permeability of the cuticular membrane was caused by the dissociation of weak acidic groups with increasing pH leading to a swelling of the cuticle induced by fixed negative charges. In addition, the pH-dependent size of the hydration shell of the amino acids was identified as a secondary factor explaining the variability of cuticular permeances.”
“The organic donor-acceptor nanostructure formation processes of C-60 and alpha-sexithiophene (6T) on graphite are monitored by in situ low-temperature scanning tunneling microscopy and synchrotron-based photoelectron spectroscopy experiments.