Four compounds in clinical trials for anaemia treatment are potent inhibitors of the hypoxia inducible factor (HIF) prolyl hydroxylases (PHDs), but differ in potency and how they interact with HIF at the PHD active site.

Huntington disease results from an expanded polyglutamine region in the N terminus of the huntingtin protein. HD pathology is characterized by neuronal degeneration and protein inclusions containing N-terminal fragments of mutant huntingtin. Structural information is minimal, though it is believed that mutant huntingtin polyglutamine adopts ␤ structure upon conversion to a toxic form. To this end, we designed mammalian cell expression constructs encoding compact ␤ variants of Htt exon 1 N-terminal fragment and tested their ability to aggregate and induce toxicity in cultured neuronal cells. In parallel, we performed molecular dynamics simulations, which indicate that constructs with expanded polyglutamine ␤-strands are stabilized by main-chain hydrogen bonding. Finally, we found a correlation between the reactivity to 3B5H10, an expanded polyglutamine antibody that recognizes a compact ␤ rich hairpin structure, and the ability to induce cell toxicity. These data are consistent with an important role for a compact ␤ structure in mutant huntingtin-induced cell toxicity.

The 2-oxoglutarate (2OG)-dependent Jumonji C domain (JmjC) family is the largest family of histone lysine demethylases. There is interest in developing small-molecule probes that modulate JmjC activity to investigate their biological roles. 5-Carboxy-8-hydroxyquinoline (IOX1) is the most potent broad-spectrum inhibitor of 2OG oxygenases, including the JmjC demethylases, reported to date; however, it suffers from low cell permeability. Here, we describe structure–activity relationship studies leading to the discovery of an n-octyl ester form of IOX1 with improved cellular potency (EC50 value of 100 to 4 μm). These findings are supported by in vitro inhibition and selectivity studies, docking studies, activity versus toxicity analysis in cell cultures, and intracellular uptake measurements. The n-octyl ester was found to have improved cell permeability; it was found to inhibit some JmjC demethylases in its intact ester form and to be more selective than IOX1. The n-octyl ester of IOX1 should find utility as a starting point for the development of JmjC inhibitors and as a use as a cell-permeable tool compound for studies investigating the roles of 2OG oxygenases in epigenetic regulation.

are co-founders of a company, ReOx, which aims to exploit basic science discoveries about the hypoxic response for therapeutic benefit.