BET protein inhibitor apabetalone (RVX-208) suppresses pro-inflammatory hyper-activation of monocytes from patients with cardiovascular disease and type 2 diabetes

Abstract

Background Patients with cardiovascular disease (CVD) and type 2 diabetes (DM2) have a high residual risk for experiencing a major adverse cardiac event. Dysregulation of epigenetic mechanisms of gene transcription in innate immune cells contributes to CVD development but is currently not targeted by therapies. Apabetalone (RVX-208) is a small molecule inhibitor of bromodomain and extra-terminal (BET) proteins—histone acetylation readers that drive pro-inflammatory and pro-atherosclerotic gene transcription. Here, we assess the impact of apabetalone on ex vivo inflammatory responses of monocytes from DM2 + CVD patients. Results Monocytes isolated from DM2 + CVD patients and matched controls were treated ex vivo with apabetalone, interferon γ (IFNγ), IFNγ + apabetalone or vehicle and phenotyped for gene expression and protein secretion. Unstimulated DM2 + CVD monocytes had higher baseline IL-1α, IL-1β and IL-8 cytokine gene expression and Toll-like receptor (TLR) 2 surface abundance than control monocytes, indicating pro-inflammatory activation. Further, DM2 + CVD monocytes were hyper-responsive to stimulation with IFNγ, upregulating genes within cytokine and NF-κB pathways > 30% more than control monocytes (p < 0.05). Ex vivo apabetalone treatment countered cytokine secretion by DM2 + CVD monocytes at baseline (GROα and IL-8) and during IFNγ stimulation (IL-1β and TNFα). Apabetalone abolished pro-inflammatory hyper-activation by reducing TLR and cytokine gene signatures more robustly in DM2 + CVD versus control monocytes. Conclusions Monocytes isolated from DM2 + CVD patients receiving standard of care therapies are in a hyper-inflammatory state and hyperactive upon IFNγ stimulation. Apabetalone treatment diminishes this pro-inflammatory phenotype, providing mechanistic insight into how BET protein inhibition may reduce CVD risk in DM2 patients.

Bromodomain and Extraterminal Protein Inhibitor, Apabetalone (RVX-208), Reduces ACE2 Expression and Attenuates SARS-Cov-2 Infection In Vitro

“…In this study, we report apabetalone, the most clinically advanced BETi with BD2 selectivity, reduces SARS-CoV-2 infection in cell culture models through downregulation of viral uptake receptors. Previous studies have demonstrated apabetalone suppresses activation of innate and adaptive immune responses [ 31 , 41 , 42 , 43 , 44 ], and thus, apabetalone may reduce both SARS-CoV-2 infection and control hyperinflammatory conditions associated with poor outcomes in a dual mechanism of action.…”

“…In vitro, apabetalone treatment reduced proinflammatory gene expression in vascular endothelial cells [ 31 , 41 , 43 ], monocytes [ 31 ], and vascular smooth muscle cells [ 30 ]. Further, apabetalone diminished the production of pro-inflammatory cytokines (TNF-α and IL-1β) in hyper-responsive monocytes isolated from diabetic patients with cardiovascular disease [ 42 ]. Apabetalone also reduced vascular inflammation in a mouse model [ 41 ] and countered cytokine-driven acute phase responses both in cell culture and in mice [ 43 ].…”

Bromodomain and extraterminal protein inhibitor, apabetalone (RVX-208), reduces ACE2 expression and attenuates SARS-CoV-2 infection in vitro

“…In this study, we report apabetalone, the most clinically advanced BETi with BD2 selectivity, reduces SARS-CoV-2 infection in cell culture models through downregulation of viral uptake receptors. Previous studies have demonstrated apabetalone suppresses activation of innate and adaptive immune responses 31,[41][42][43][44] , and thus apabetalone may reduce both SARS-CoV-2 infection and control hyperinflammatory conditions associated with poor outcomes in a dual mechanism of action.…”

“…In vitro, apabetalone treatment reduced proinflammatory gene expression in vascular endothelial cells 31,41,43 , monocytes 31 , and vascular smooth muscle cells 30 . Further, apabetalone diminished the production of pro-inflammatory cytokines (TNF---responsive monocytes isolated from diabetic patients with cardiovascular disease 42 . Apabetalone also reduced vascular inflammation in a mouse model 41 and countered cytokine driven acute phase responses both in cell culture and in mice 43 .…”

Design, synthesis, biological evaluation, and molecular docking of 1,7-dibenzyl-substituted theophylline derivatives as novel BRD4-BD1-selective inhibitors

“…Due to that the area of research is not well understood, exploiting molecular probes with excellent selectivity toward BRD4-BD1 or BD2 will be conducive to analyze their roles. Furthermore, although drug-like properties of BRD4 inhibitors have been verified preliminarily in clinical trials for the treatment of cancers and cardiovascular diseases [18][19][20][21][22][23][24][25][26][27], only a few inhibitors fulfill the selectivity between two tandem bromodomains of BRD4 (Fig. 1A) [28][29][30][31][32][33] and mechanism-based toxicity appeared in clinical trials of some pan-BRD4 inhibitors, such as thrombocytopenia and gastrointestinal toxicity [24,34], impeding more extensive clinical application.…”