Investigational drugs in phase II clinical trials for acute coronary syndromes

Identification of selective 5-LOX and FLAP inhibitors as novel anti-inflammatory agents by ligand-based virtual screening

Inflammation is a multifaceted biological process in which the conversion of arachidonic acid to eicosanoids, including prostaglandins and leukotrienes (LTs), plays a crucial role. 5-Lipoxygenase (5-LOX) is a key enzyme in cellular LT biosynthesis, and it is supported by the accessory protein 5-lipoxygenase-activating protein (FLAP). Pharmacological interventions to modulate LTs aim at either decreasing their biosynthesis or at mitigating their biological effects. Therefore, inhibiting 5-LOX or FLAP represents a useful strategy to reduce inflammation. Herein we present the identification and pharmacological evaluation of novel inhibitors targeting 5-LOX or FLAP. By means of a ligand-based virtual screening approach, we selected 38 compounds for in vitro assays. Among them, ALR-38 exhibits direct 5-LOX inhibition, while ALR-6 and ALR-27 showed potential as FLAP inhibitors. These latter not only reduced LT production but also promoted the generation of specialized pro-resolving mediators in specific human macrophage phenotypes. Interestingly, the identified compounds turned out to be selective for their respective targets, as none of them displayed activity towards microsomal prostaglandin E2 synthase-1 and soluble epoxide hydrolase, which are other proteins involved in eicosanoid biosynthesis. Thus, these compounds are endowed with potential therapeutic utility in mitigating inflammatory responses and might offer a venue for tackling inflammation-based disorders.

Structures of Leukotriene Biosynthetic Enzymes and Development of New Therapeutics

Leukotrienes are potent immune-regulating lipid mediators with patho-genic roles in inflammatory and allergic diseases, particularly asthma. These autacoids also contribute to low-grade inflammation, a hallmark of cardiovascular, neurodegenerative, metabolic, and tumor diseases. Biosynthesis of leukotrienes involves release and oxidative metabolism of arachidonic acid and proceeds via a set of cytosolic and integral membrane enzymes that are typically expressed by cells of the innate immune system. In activated cells, these enzymes traffic and assemble at the endoplasmic and perinuclear membrane, together comprising a biosynthetic complex. Here we describe recent advances in our molecular understanding of the protein components of the leukotriene-synthesizing enzyme machinery and also briefly touch upon the leukotriene receptors. Moreover, we discuss emerging opportunities for pharmacological intervention and development of new therapeutics.

Chromatin state dynamics confers specific therapeutic strategies in enhancer subtypes of colorectal cancer

OBJECTIVE

Enhancer aberrations are beginning to emerge as a key epigenetic feature of colorectal cancers (CRC), however, a comprehensive knowledge of chromatin state patterns in tumour progression, heterogeneity of these patterns and imparted therapeutic opportunities remain poorly described.

DESIGN

We performed comprehensive epigenomic characterisation by mapping 222 chromatin profiles from 69 samples (33 colorectal adenocarcinomas, 4 adenomas, 21 matched normal tissues and 11 colon cancer cell lines) for six histone modification marks: H3K4me3 for Pol II-bound and CpG-rich promoters, H3K4me1 for poised enhancers, H3K27ac for enhancers and transcriptionally active promoters, H3K79me2 for transcribed regions, H3K27me3 for polycomb repressed regions and H3K9me3 for heterochromatin.

RESULTS

We demonstrate that H3K27ac-marked active enhancer state could distinguish between different stages of CRC progression. By epigenomic editing, we present evidence that gains of tumour-specific enhancers for crucial oncogenes, such as ASCL2 and FZD10, was required for excessive proliferation. Consistently, combination of MEK plus bromodomain inhibition was found to have synergistic effects in CRC patient-derived xenograft models. Probing intertumour heterogeneity, we identified four distinct enhancer subtypes (EPIgenome-based Classification, EpiC), three of which correlate well with previously defined transcriptomic subtypes (consensus molecular subtypes, CMSs). Importantly, CMS2 can be divided into two EpiC subgroups with significant survival differences. Leveraging such correlation, we devised a combinatorial therapeutic strategy of enhancer-blocking bromodomain inhibitors with pathway-specific inhibitors (PARPi, EGFRi, TGFβi, mTORi and SRCi) for EpiC groups.

CONCLUSION

Our data suggest that the dynamics of active enhancer underlies CRC progression and the patient-specific enhancer patterns can be leveraged for precision combination therapy.

High Sensitivity C-reactive Protein (hsCRP) and its Implications in Cardiovascular Outcomes

Atherosclerosis and its fearsome complications represent the first cause of morbidity and mortality worldwide. Over the last two decades, several pieces of evidence have been accumulated, suggesting a central role of inflammation in atheroma development. High sensitivity C-reactive protein (hsCRP) is a well-established marker of cardiovascular (CV) disease; high levels of hsCRP have been associated with adverse CV outcome after acute coronary syndrome (ACS) and, despite some controversy, an active role for hsCRP in initiation and development of the atherosclerotic plaque has been also proposed. Randomized clinical trials focusing on hsCRP have been crucial in elucidating the anti-inflammatory effects of statin therapy. Thus, hsCRP has been progressively considered a real CV risk factor likewise to low-density lipoprotein cholesterol (LDL-C), expanding the concept of residual CV inflammatory risk. Subsequent research has been designed to investigate potential new targets of atherothrombotic protection. Despite the fact that the clinical usefulness of hsCRP is widely recognized, hsCRP may not represent the ideal target of specific anti-inflammatory therapies. Clinical investigations, therefore, have also focused on other inflammatory mediators, restricting hsCRP to an indicator rather than a therapeutic target. The aim of the present review is to provide an illustrative overview of the current knowledge of atherosclerosis and inflammation, highlighting the most representative clinical studies of lipid-lowering and antiinflammatory therapies focused on hsCRP in CV diseases.

Immune and Inflammation in Acute Coronary Syndrome: Molecular Mechanisms and Therapeutic Implications

Acute coronary syndrome (ACS) is a major cause of acute death worldwide. Both innate and adaptive immunity regulate atherosclerosis progression, plaque stability, and thrombus formation. Immune and inflammation dysfunction have been indicated in the pathogenesis of ACS. The imbalance in the proatherogenic and antiatherogenic immune networks promotes the transition of plaques from a stable to unstable state and results in the occurrence of acute coronary events. The residual inflammatory risk (RIR) has received increasing attention in recent years, and lowering RIR has been expected to improve the outcomes of ACS patients. The CANTOS, COLCOT, and LoDoCo trials verified the benefits of reducing cardiovascular events using anti-inflammation therapies; however, most of the other studies focusing on lowering RIR produced negative or contradicting results. Therefore, restoring the balance in autoimmune regulation is essential because proatherogenic and antiatherogenic immunomodulatory effects are equally important in the complex human immune network. In this review, we summarized the recent evidence of the roles of proatherogenic and antiatherogenic immune networks in the pathogenesis of ACS and discussed how immune and inflammation contribute to atherosclerosis progression, plaque instability, and adverse cardiovascular events. We also provide a “from bench to bedside” perspective of a novel and promising personalized strategy in RIR intervention and therapeutic approaches for the treatment of ACS.

Targeted pharmacotherapy for ischemia reperfusion injury in acute myocardial infarction

INTRODUCTION

Achieving reperfusion immediately after acute myocardial infarction improves outcomes; despite this, patients remain at a high risk for mortality and morbidity at least for the first year after the event. Ischemia-reperfusion injury (IRI) has a complex pathophysiology and plays an important role in myocardial tissue injury, repair, and remodeling.

AREAS COVERED

In this review, the authors discuss the various mechanisms and their pharmacological agents currently available for reducing myocardial ischemia-reperfusion injury (IRI). They review important original investigations and trials in various clinical databases for treatments targeting IRI.

EXPERT OPINION

Encouraging results observed in many preclinical studies failed to show similar success in attenuating myocardial IRI in large-scale clinical trials. Identification of critical risk factors for IRI and targeting them individually rather than one size fits all approach should be the major focus of future research. Various newer therapies like tocilizumab, anakinra, colchicine, revacept, and therapies targeting the reperfusion injury salvage kinase pathway, survivor activating factor enhancement, mitochondrial pathways, and angiopoietin-like peptide 4 hold promise for the future.