Structural basis of synthetic agonist activation of the nuclear receptor REV-ERB

Abstract

The nuclear receptor REV-ERB plays an important role in a range of physiological processes. REV-ERB behaves as a ligand-dependent transcriptional repressor and heme has been identified as a physiological agonist. Our current understanding of how ligands bind to and regulate transcriptional repression by REV-ERB is based on the structure of heme bound to REV-ERB. However, porphyrin (heme) analogues have been avoided as a source of synthetic agonists due to the wide range of heme binding proteins and potential pleotropic effects. How non-porphyrin synthetic agonists bind to and regulate REV-ERB has not yet been defined. Here, we characterize a high affinity synthetic REV-ERB agonist, STL1267, and describe its mechanism of binding to REV-ERB as well as the method by which it recruits transcriptional corepressor both of which are unique and distinct from that of heme-bound REV-ERB.

REV-ERB activation as a novel pharmacological approach for treating inflammatory pain

“…We therefore used a standard procedure of differentiating Thp-1 cells towards an inflammatory macrophage phenotype and evaluated the effects of our small molecule REV-ERB agonists on inflammatory mediators. Our results not only validated previously published results demonstrating the antiinflammatory effects of REV-ERB agonist SR9009, it also demonstrated that the new compound, STL-1267, has greater efficacy in these models as compared to SR9009 (Morioka et al, 2016;Morioka et al, 2021;Murray et al, 2022).…”

“…Measurments of footpad thickness show that a single administration of REV-ERB agonist (either SR9009 or STL1267) was sufficient to reduce footpad inflammation driven by λ-Carrageenan injection at 4-hpi (Figure 4B). STL1267 continued to suppress footpad inflammation at 24-hpi, suggesting that it may be more efficacious at the 50 mg/kg dose as compared to SR9009 which was given at 100 mg/kg, as determined by our previous work with these compounds (Solt et al, 2012;Murray et al, 2022). By 48-hpi, there was no significant change in footpad thickness as compared to the vehicle control group, which was expected given the rats only received a single dose of REV-ERB agonists and the compounds should have been completely metabolized by this time.…”

“…Both SR9009 ( Solt et al, 2012 ) and STL1267 ( Murray et al, 2022 ) ( Figure 1B ) were synthesized in house as previously described.…”

“…On the first day of the experiment, rats were administered a single dose of either vehicle control (10% DMSO; 12% CremophoreEL; 78% PBS), 100 mg/kg SR9009, or 50 mg/kg STL1267 via intraperitoneal injection. Dosing was determined by our previous work in which we evaluated different vehicles and performed pharmacokinetic analysis ( Murray et al, 2022 ). Injection of compounds occurred as close to “lights on” as possible (i.e., 7 a.m.).…”

“…Recently, we described a novel small molecule agonist for REV-ERB, STL1267, with greater potency and selectivity for REV-ERB than SR9009 ( Murray et al, 2022 ). For our studies, we compared the STL1267 compound to the first-generation in vivo REV-ERB agonist, SR9009, to evaluate direct REV-ERB effects on inflammation and pain.…”