Developing HDAC4-Selective Protein Degraders To Investigate the Role of HDAC4 in Huntington's Disease Pathology.

Huntington's disease (HD) is a lethal autosomal dominant neurodegenerative disorder resulting from a CAG repeat expansion in the huntingtin (HTT) gene. The product of translation of this gene is a highly aggregation-prone protein containing a polyglutamine tract >35 repeats (mHTT) that has been shown to colocalize with histone deacetylase 4 (HDAC4) in cytoplasmic inclusions in HD mouse models. Genetic reduction of HDAC4 in an HD mouse model resulted in delayed aggregation of mHTT, along with amelioration of neurological phenotypes and extended lifespan. To further investigate the role of HDAC4 in cellular models of HD, we have developed bifunctional degraders of the protein and report the first potent and selective degraders of HDAC4 that show an effect in multiple cell lines, including HD mouse model-derived cortical neurons. These degraders act via the ubiquitin-proteasomal pathway and selectively degrade HDAC4 over other class IIa HDAC isoforms (HDAC5, HDAC7, and HDAC9).

Identification of a Potent, Selective, and Brain-Penetrant Rho Kinase Inhibitor and its Activity in a Mouse Model of Huntington's Disease.

The Rho kinase (ROCK) pathway is implicated in the pathogenesis of several conditions, including neurological diseases. In Huntington's disease (HD), ROCK is implicated in mutant huntingtin (HTT) aggregation and neurotoxicity, and members of the ROCK pathway are increased in HD mouse models and patients. To validate this mode of action as a potential treatment for HD, we sought a potent, selective, central nervous system (CNS)-penetrant ROCK inhibitor. Identifying a compound that could be dosed orally in mice with selectivity against other AGC kinases, including protein kinase G (PKG), whose inhibition could potentially activate the ROCK pathway, was paramount for the program. We describe the optimization of published ligands to identify a novel series of ROCK inhibitors based on a piperazine core. Morphing of the early series developed in-house by scaffold hopping enabled the identification of a compound exhibiting high potency and desired selectivity and demonstrating a robust pharmacodynamic (PD) effect by the inhibition of ROCK-mediated substrate (MYPT1) phosphorylation after oral dosing.

Carbonated rankinite binder: effect of curing parameters on microstructure, strength development and durability performance.

Due to the high CO2-footprint of ordinary Portland cement (OPC), the search for alternative binders is now in a full swing. Rankinite-which is a hydraulically inactive material and low in calcium, is a real alternative to OPC, as it absorbs the harmful greenhouse gas from the air through carbonation hardening. Nevertheless, the carbonation hardening has not yet been fully clarified and sufficiently investigated. In this study we show that rankinite achieves a final strength exceeding 100 MPa at 45 °C and 24 h, whereby the binder is only ~ 50% carbonated. The reaction is diffusion limited while a dense layer of carbonation products around the rankinite grains hinders a higher degree of carbonation. The carbonation reaction could be fully characterized by spatially resolved microanalysis such as LA-ICP-MS, NMR and XRD. Finally, durability tests show the excellent suitability of the rankinite binder for a wide range of applications, making it an attractive material not only from an environmental point of view.