Alka Mehta

Discovery of 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221) as a functional antagonist of the apelin (APJ) receptor

The recently discovered apelin/APJ system has emerged as a critical mediator of cardiovascular homeostasis and is associated with the pathogenesis of cardiovascular disease. A role for apelin/APJ in energy metabolism and gastrointestinal function has also recently emerged. We disclose the discovery and characterization of 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221), a potent APJ functional antagonist in cell-based assays that is >37-fold selective over the closely related angiotensin II type 1 (AT1) receptor. ML221 was derived from an HTS of the ~330,600 compound MLSMR collection. This antagonist showed no significant binding activity against 29 other GPCRs, except to the κ-opioid and benzodiazepinone receptors (<50/<70%I at 10 μM). The synthetic methodology, development of structure-activity relationship (SAR), and initial in vitro pharmacologic characterization are also presented.

Targeting α-synuclein oligomers by protein-fragment complementation for drug discovery in synucleinopathies

Objective: Reducing the burden of α-synuclein oligomeric species represents a promising approach for disease-modifying therapies against synucleinopathies such as Parkinson’s disease and dementia with Lewy bodies. However, the lack of efficient drug discovery strategies that specifically target α-synuclein oligomers has been a limitation to drug discovery programs. Research design and methods: Here we describe an innovative strategy that harnesses the power of bimolecular protein-fragment complementation to monitor synuclein–synuclein interactions. We have developed two robust models to monitor α-synuclein oligomerization by generating novel stable cell lines expressing α-synuclein fusion proteins for either fluorescent or bioluminescent protein-fragment complementation under the tetracycline-controlled transcriptional activation system. Main outcome measures: A pilot screen was performed resulting in the identification of two potential hits, a p38 MAPK inhibitor and a casein kinase 2 inhibitor, thereby demonstrating the suitability of our protein-fragment complementation assay for the measurement of α-synuclein oligomerization in living cells at high throughput. Conclusions: The application of the strategy described herein to monitor α-synuclein oligomer formation in living cells with high throughput will facilitate drug discovery efforts for disease-modifying therapies against synucleinopathies and other proteinopathies.