Biology subjects

Pearce, K. H.

Publications and source records attributed to Pearce, K. H..

3 recordsLinked to original sources

bioRxiv2021

AD Informer Set: Chemical tools to facilitate Alzheimer's disease drug discovery

IntroductionThe portfolio of novel targets to treat Alzheimers disease (AD) has been enriched by the AMP-AD program. MethodsA cheminformatics-driven effort enabled identification of existing small molecule modulators for many protein targets nominated by AMP-AD and suitable positive control compounds to be included in the set. ResultsWe have built an annotated set of 171 small molecule modulators, including mostly inhibitors, targeting 98 unique proteins that have been nominated by AMP-AD consortium members as novel targets for AD treatment. These small molecules vary in their quality and should be considered chemical tools that can be used in efforts to validate therapeutic hypotheses, but which would require further optimization. A physical copy of the AD Informer Set can be ordered via the AD Knowledge Portal. DiscussionSmall molecule tools that enable target validation are important tools for the translation of novel hypotheses into viable therapeutic strategies for AD.

neuroscience↗

bioRxiv2021

REPROGRAMMING CBX8-PRC1 FUNCTION WITH A POSITIVE ALLOSTERIC MODULATOR

ABSTRACTCanonical targeting of Polycomb Repressive Complex 1 (PRC1) to repress developmental genes is mediated by cell type-specific, paralogous chromobox (CBX) proteins (CBX2, 4, 6, 7 and 8). Based on their central role in silencing and their misregulation associated with human disease including cancer, CBX proteins are attractive targets for small molecule chemical probe development. Here, we have used a quantitative and target-specific cellular assay to discover a potent positive allosteric modulator (PAM) of CBX8. The PAM activity of UNC7040 antagonizes H3K27me3 binding by CBX8 while increasing interactions with nucleic acids and participation in variant PRC1. We show that treatment with UNC7040 leads to efficient PRC1 chromatin eviction, loss of silencing and reduced proliferation across different cancer cell lines. Our discovery and characterization of UNC7040 not only revealed the most cellularly potent CBX8-specific chemical probe to date, but also corroborates a mechanism of polycomb regulation by non-histone lysine methylated interaction partners.

synthetic biology↗

bioRxiv2020

Repurposing the Ebola and Marburg Virus Inhibitors Tilorone, Quinacrine and Pyronaridine: In vitro Activity Against SARS-CoV-2 and Potential Mechanisms

SARS-CoV-2 is a newly identified virus that has resulted in over 1.3 M deaths globally and over 59 M cases globally to date. Small molecule inhibitors that reverse disease severity have proven difficult to discover. One of the key approaches that has been widely applied in an effort to speed up the translation of drugs is drug repurposing. A few drugs have shown in vitro activity against Ebola virus and demonstrated activity against SARS-CoV-2 in vivo. Most notably the RNA polymerase targeting remdesivir demonstrated activity in vitro and efficacy in the early stage of the disease in humans. Testing other small molecule drugs that are active against Ebola virus would seem a reasonable strategy to evaluate their potential for SARS-CoV-2. We have previously repurposed pyronaridine, tilorone and quinacrine (from malaria, influenza, and antiprotozoal uses, respectively) as inhibitors of Ebola and Marburg virus in vitro in HeLa cells and of mouse adapted Ebola virus in mouse in vivo. We have now tested these three drugs in various cell lines (VeroE6, Vero76, Caco-2, Calu-3, A549-ACE2, HUH-7 and monocytes) infected with SARS-CoV-2 as well as other viruses (including MHV and HCoV 229E). The compilation of these results indicated considerable variability in antiviral activity observed across cell lines. We found that tilorone and pyronaridine inhibited the virus replication in A549-ACE2 cells with IC50 values of 180 nM and IC50 198 nM, respectively. We have also tested them in a pseudovirus assay and used microscale thermophoresis to test the binding of these molecules to the spike protein. They bind to spike RBD protein with Kd values of 339 nM and 647 nM, respectively. Human Cmax for pyronaridine and quinacrine is greater than the IC50 hence justifying in vivo evaluation. We also provide novel insights into their mechanism which is likely lysosomotropic.

pharmacology and toxicology↗