Gemcabene, a first-in-class lipid-lowering agent in late-stage development, down-regulates acute-phase C-reactive protein via C/EBP-δ-mediated transcriptional mechanism

Abstract

Inflammation plays a key role in setting the stage leading to atherosclerosis progression, and high-sensitivity C-reactive protein (CRP) has been recognized as a predictor of cardiovascular risk. As a monotherapy and in combination with statins, gemcabene markedly reduced CRP in humans. Present investigation was undertaken to understand the mechanism of CRP reduction. In human hepatoma cells, gemcabene inhibited IL-6 plus IL-1β-induced CRP production in a concentration-dependent manner, reaching 70% inhibition at 2 mM. In TNF-α-stimulated primary human coronary artery endothelial cells, both CRP and IL-6 productions were reduced by 70% at 2 mM gemcabene concentration. To investigate the mechanism of gemcabene-mediated reduction of CRP, transfection studies were performed with human CRP regulatory sequences in luciferase/β-gal system that showed 25-fold increase in IL-6- and IL-6 plus IL-1β-stimulated CRP transcription. Luciferase activity was reduced by 50% by gemcabene, suggesting transcriptional down-regulation of CRP. Site-directed mutagenesis of human CRP promoter revealed that the overlapping downstream C/EBP and NF-κB binding sites are important for gemcabene-mediated CRP transcription. Gel shift assays identified the transcription factor that binds to the downstream CRP promoter as C/EBP-δ. In conclusion, gemcabene decreases CRP by C/EBP-δ and NF-κB-mediated transcriptional mechanism and suppresses IL-6 and IL-1β-induced CRP production.

Gemcabene, a First-in-Class Hypolipidemic Small Molecule in Clinical Development, Attenuates Osteoarthritis and Pain in Animal Models of Arthritis and Pain

“…Based on our present results, we demonstrate that gemcabene is an anti-inflammatory agent and attenuates inflammatory disease in animal models. These findings are consistent with the results in clinical studies showing reduction of pro-inflammatory protein CRP ( Stein et al, 2016 ) and in cell models showing inflammation-induced reduction of CRP mRNA and protein ( Srivastava et al, 2018 ). Attenuation of disease severity by gemcabene in multiple inflammatory disease models reported here further support gemcabene as a potential anti-inflammatory agent.…”

“…The levels of IL-6 and its receptor are elevated in synovial fluid and serum in humans with rheumatoid arthritis ( Kotake et al, 1996 ; Robak et al, 1998 ). Thus, in a number of animal models of inflammatory diseases, gemcabene showed efficacy, which corroborate cell-based findings on inflammation-induced inhibition of CRP production by gemcabene ( Srivastava et al, 2018 ). The attenuation of disease severity in animal models of pain in the present study further demonstrates gemcabene as an anti-inflammatory agent.…”

“…PPAR-α and PPAR-δ agonists are known to have anti-inflammatory activities ( Gonzalez et al, 2009 ; Bojic et al, 2014 ), but gemcabene does not appear to have anti-inflammatory activities through PPAR activation. Cell-based studies with gemcabene indicated that gemcabene down-regulates CRP gene expression through down-regulation of C/EBP-δ and NF-κB promoter activities ( Srivastava et al, 2018 ). Anti-inflammatory activities of many molecules are attributed to down-regulation of NF-κB ( Srivastava et al, 2015 ).…”

“…CRP, an acute phase reactant, is produced mainly in the liver in response to inflammation and has been traditionally considered, as a “downstream” indicator of the inflammatory cascade ( Arcone et al, 1988 ). We have reported that gemcabene inhibits cytokine-stimulated CRP production in human hepatoma PLC/PRF/5 (Alexander) cells ( Srivastava et al, 2018 ). Pro-inflammatory cytokines (IL-6 and IL-1β) are known to induce CRP ( Li et al, 1990 ) and associated with inflammatory conditions like pain and OA ( Osiri et al, 1998 ; Brennan and McInnes, 2008 ; Mori et al, 2011 ).…”

Recent advances in synthetic pharmacotherapies for dyslipidaemias

“…Additional studies clearly demonstrated an anti-inflammatory profile, associated with a lowered expression of the hs-CRP gene regulating mechanisms. 95 In view of the significant activity of gemcabene on liver lipids and inflammation, a specific study addressed the anti-inflammatory, lipid altering and cell signalling genes in an animal model of non-alcoholic fatty liver disease (NAFLD). In the STAM TM murine model of NAFLD, gemcabene significantly down-regulated liver mRNA markers of inflammation, lipogenesis, lipid modulation and fibrosis, thus presenting this agent as of potential interest in the management of this very frequent human disease.…”