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Parkinson's disease is the second most common neurodegenerative disorder, affecting nearly 10 million people worldwide. Ferroptosis, a recently identified form of regulated cell death characterized by 15-lipoxygenase-mediated hydroperoxidation of membrane lipids, has been implicated in neurodegenerative disorders including amyotrophic lateral sclerosis and Parkinson's disease. Pharmacological inhibition of 15 -lipoxygenase to prevent iron- and lipid peroxidation-associated ferroptotic cell death is a rational strategy for the treatment of Parkinson's disease. We report here the characterization of PTC-041 as an anti-ferroptotic reductive lipoxygenase inhibitor developed for the treatment of Parkinson's disease. In these studies, PTC-041 potently protects primary human Parkinson's disease patient-derived fibroblasts from lipid peroxidation and subsequent ferroptotic cell death and prevents ferroptosis-related neuronal loss and astrogliosis in primary rat neuronal cultures. Additionally, PTC-041 prevents ferroptotic-mediated α-synuclein protein aggregation and nitrosylation in vitro, suggesting a potential role for anti-ferroptotic lipoxygenase inhibitors in mitigating pathogenic aspects of synucleinopathies such as Parkinson's disease. We further found that PTC-041 protects against synucleinopathy in vivo, demonstrating that PTC-041 treatment of Line 61 transgenic mice protects against α-synuclein aggregation and phosphorylation as well as prevents associated neuronal and non-neuronal cell death. Finally, we show that. PTC-041 protects against 6-hydroxydopamine-induced motor deficits in a hemiparkinsonian rat model, further validating the potential therapeutic benefits of lipoxygenase inhibitors in the treatment of Parkinson's disease. [ABSTRACT FROM AUTHOR]

Utreloxastat (PTC857) is a 15‐lipoxygenase inhibitor being developed to treat amyotrophic lateral sclerosis. This first‐in‐human study investigated the safety and pharmacokinetics of utreloxastat in healthy volunteers (N = 82) in a double‐blind, placebo‐controlled trial. The effects of a single ascending dose (100–1000 mg), multiple ascending doses (150–500 mg), and food (500 mg) on the pharmacokinetics and safety of utreloxastat were evaluated. Following single doses, the time to maximum plasma concentration (Cmax) was observed ≈4 hours after dosing and the terminal half‐life ranged from 20 to 25.3 hours. The Cmax and area under the concentration‐time curve (AUC) increased slightly over dose proportionally. Following multiple doses (once daily/twice daily), the apparent clearance reduced and terminal half‐life was ≥33 hours. There was no apparent difference of exposure following morning or evening doses. Varying diets increased the Cmax and AUCs of utreloxastat but did not alter time to Cmax. There were no gender‐based differences in exposure. Utreloxastat showed no marked safety signal following single doses up to 1000 mg and multiple doses over 14 days of 500 mg once daily or 250 mg twice daily. The results support further development of utreloxastat for the treatment of patients with amyotrophic lateral sclerosis at a 250‐mg twice‐daily dose administered with food. [ABSTRACT FROM AUTHOR]

We report the quantitative, label-free analysis of protein--protein interactions in free solution within picoliter volumes using backscatter interferometry (BSI). Changes in the refractive index are measured for solutions introduced on a PDMS microchip allowing determination of forward and reverse rate constants for two-mode binding. Time-dependent BSI traces are directly fit using a global analysis approach to characterize the interaction of the small heat-shock protein [alpha]-Crystallin with two substrates: destabilized mutants of T4 lysozyme and the in vivo target [beta]B1-Crystallin. The results recapitulate the selectivity of [alpha]B-Crystallin differentially binding T4L mutants according to their free energies of unfolding. Furthermore, we demonstrate that an [alpha]A-Crystallin mutant linked to hereditary cataract has activated binding to [beta]B1-Crystallin. Binding isotherms obtained from steady-state values of the BSI signal yielded meaningful dissociation constants and establishes BSI as a novel tool for the rapid identification of molecular partners using exceedingly small sample quantities under physiological conditions. This work demonstrates that BSI can be extended to screen libraries of disease-related mutants to quantify changes in affinity and/or kinetics of binding.